1<!DOCTYPE html> 2<html> 3 <head> 4 <title> 5 Android 7.0, (N) Compatibility Definition 6 </title> 7 <link href="source/android-cdd.css" rel="stylesheet" type="text/css"/> 8 </head> 9 <meta charset="UTF-8"> 10 <body> 11 <h1>Android 7.0 Compatibility Definition</h1> 12 <h6> 13 Table of Contents 14 </h6> 15 <div id="toc"> 16 <div id="toc_left"> 17 <p class="toc_h1"><a href="#1_introduction">1. Introduction</a> </p> 18 19 <p class="toc_h1"><a href="#2_device_types">2. Device Types</a> </p> 20 21 <p class="toc_h2"><a href="#2_1_device_configurations">2.1 Device Configurations</a> </p> 22 23 <p class="toc_h1"><a href="#3_software">3. Software</a> </p> 24 25 <p class="toc_h2"><a href="#3_1_managed_api_compatibility">3.1. Managed API Compatibility</a> </p> 26 27 <p class="toc_h2"><a href="#3_1_1_android_extensions">3.1.1. Android Extensions</a> </p> 28 29 <p class="toc_h2"><a href="#3_2_soft_api_compatibility">3.2. Soft API Compatibility</a> </p> 30 31 <p class="toc_h3"><a href="#3_2_1_permissions">3.2.1. Permissions</a> </p> 32 33 <p class="toc_h3"><a href="#3_2_2_build_parameters">3.2.2. Build Parameters</a> </p> 34 35 <p class="toc_h3"><a href="#3_2_3_intent_compatibility">3.2.3. Intent Compatibility</a> </p> 36 37 <p class="toc_h4"><a href="#3_2_3_1_core_application_intents">3.2.3.1. Core Application Intents</a> </p> 38 39 <p class="toc_h4"><a href="#3_2_3_2_intent_resolution">3.2.3.2. Intent Resolution</a> </p> 40 41 <p class="toc_h4"><a href="#3_2_3_3_intent_namespaces">3.2.3.3. Intent Namespaces</a> </p> 42 43 <p class="toc_h4"><a href="#3_2_3_4_broadcast_intents">3.2.3.4. Broadcast Intents</a> </p> 44 45 <p class="toc_h4"><a href="#3_2_3_5_default_app_settings">3.2.3.5. Default App Settings</a> </p> 46 47 <p class="toc_h2"><a href="#3_3_native_api_compatibility">3.3. Native API Compatibility</a> </p> 48 49 <p class="toc_h3"><a href="#3_3_1_application_binary_interfaces">3.3.1. Application Binary Interfaces</a> </p> 50 51 <p class="toc_h4"><a href="#3_3_1_1_graphic_libraries">3.3.1.1. Graphic Libraries</a> </p> 52 53 <p class="toc_h3"><a href="#3_3_2_32-bit_arm_native_code_compatibility">3.3.2. 32-bit ARM Native Code Compatibility</a> </p> 54 55 <p class="toc_h2"><a href="#3_4_web_compatibility">3.4. Web Compatibility</a> </p> 56 57 <p class="toc_h3"><a href="#3_4_1_webview_compatibility">3.4.1. WebView Compatibility</a> </p> 58 59 <p class="toc_h3"><a href="#3_4_2_browser_compatibility">3.4.2. Browser Compatibility</a> </p> 60 61 <p class="toc_h2"><a href="#3_5_api_behavioral_compatibility">3.5. API Behavioral Compatibility</a> </p> 62 63 <p class="toc_h2"><a href="#3_6_api_namespaces">3.6. API Namespaces</a> </p> 64 65 <p class="toc_h2"><a href="#3_7_runtime_compatibility">3.7. Runtime Compatibility</a> </p> 66 67 <p class="toc_h2"><a href="#3_8_user_interface_compatibility">3.8. User Interface Compatibility</a> </p> 68 69 <p class="toc_h3"><a href="#3_8_1_launcher_(home_screen)">3.8.1. Launcher (Home Screen)</a> </p> 70 71 <p class="toc_h3"><a href="#3_8_2_widgets">3.8.2. Widgets</a> </p> 72 73 <p class="toc_h3"><a href="#3_8_3_notifications">3.8.3. Notifications</a> </p> 74 75 <p class="toc_h3"><a href="#3_8_4_search">3.8.4. Search</a> </p> 76 77 <p class="toc_h3"><a href="#3_8_5_toasts">3.8.5. Toasts</a> </p> 78 79 <p class="toc_h3"><a href="#3_8_6_themes">3.8.6. Themes</a> </p> 80 81 <p class="toc_h3"><a href="#3_8_7_live_wallpapers">3.8.7. Live Wallpapers</a> </p> 82 83 <p class="toc_h3"><a href="#3_8_8_activity_switching">3.8.8. Activity Switching</a> </p> 84 85 </div> 86 <div id="toc_right"> 87 <p class="toc_h3"><a href="#3_8_9_input_management">3.8.9. Input Management</a> </p> 88 89 <p class="toc_h3"><a href="#3_8_10_lock_screen_media_control">3.8.10. Lock Screen Media Control</a> </p> 90 91 <p class="toc_h3"><a href="#3_8_11_screen_savers_(previously_dreams)">3.8.11. Screen savers (previously Dreams)</a> </p> 92 93 <p class="toc_h3"><a href="#3_8_12_location">3.8.12. Location</a> </p> 94 95 <p class="toc_h3"><a href="#3_8_13_unicode_and_font">3.8.13. Unicode and Font</a> </p> 96 97 <p class="toc_h3"><a href="#3_8_14_multi-windows">3.8.14. Multi-windows</a> </p> 98 99 <p class="toc_h2"><a href="#3_9_device_administration">3.9. Device Administration</a> </p> 100 101 <p class="toc_h3"><a href="#3_9_1_device_provisioning">3.9.1 Device Provisioning</a> </p> 102 103 <p class="toc_h4"><a href="#3_9_1_1_device_owner_provisioning">3.9.1.1 Device owner provisioning</a> </p> 104 105 <p class="toc_h4"><a href="#3_9_1_2_managed_profile_provisioning">3.9.1.2 Managed profile provisioning</a> </p> 106 107 <p class="toc_h2"><a href="#3_9_2_managed_profile_support">3.9.2 Managed Profile Support</a> </p> 108 109 <p class="toc_h2"><a href="#3_10_accessibility">3.10. Accessibility</a> </p> 110 111 <p class="toc_h2"><a href="#3_11_text-to-speech">3.11. Text-to-Speech</a> </p> 112 113 <p class="toc_h2"><a href="#3_12_tv_input_framework">3.12. TV Input Framework</a> </p> 114 115 <p class="toc_h3"><a href="#3_12_1_tv_app">3.12.1. TV App</a> </p> 116 117 <p class="toc_h4"><a href="#3_12_1_1_electronic_program_guide">3.12.1.1. Electronic Program Guide</a> </p> 118 119 <p class="toc_h4"><a href="#3_12_1_2_navigation">3.12.1.2. Navigation</a> </p> 120 121 <p class="toc_h4"><a href="#3_12_1_3_tv_input_app_linking">3.12.1.3. TV input app linking</a> </p> 122 123 <p class="toc_h4"><a href="#3_12_1_4_time_shifting">3.12.1.4. Time shifting</a> </p> 124 125 <p class="toc_h4"><a href="#3_12_1_5_tv_recording">3.12.1.5. TV recording</a> </p> 126 127 <p class="toc_h2"><a href="#3_13_quick_settings">3.13. Quick Settings</a> </p> 128 129 <p class="toc_h2"><a href="#3_14_vehicle_ui_apis">3.14. Vehicle UI APIs</a> </p> 130 131 <p class="toc_h3"><a href="#3_14_1__vehicle_media_ui">3.14.1. Vehicle Media UI</a> </p> 132 133 <p class="toc_h1"><a href="#4_application_packaging_compatibility">4. Application Packaging Compatibility</a> </p> 134 135 <p class="toc_h1"><a href="#5_multimedia_compatibility">5. Multimedia Compatibility</a> </p> 136 137 <p class="toc_h2"><a href="#5_1_media_codecs">5.1. Media Codecs</a> </p> 138 139 <p class="toc_h3"><a href="#5_1_1_audio_codecs">5.1.1. Audio Codecs</a> </p> 140 141 <p class="toc_h3"><a href="#5_1_2_image_codecs">5.1.2. Image Codecs</a> </p> 142 143 <p class="toc_h3"><a href="#5_1_3_video_codecs">5.1.3. Video Codecs</a> </p> 144 145 <p class="toc_h2"><a href="#5_2_video_encoding">5.2. Video Encoding</a> </p> 146 147 <p class="toc_h3"><a href="#5_2_1_h_263">5.2.1. H.263</a> </p> 148 149 <p class="toc_h3"><a href="#5_2_2_h-264">5.2.2. H-264</a> </p> 150 151 <p class="toc_h3"><a href="#5_2_3_vp8">5.2.3. VP8</a> </p> 152 153 <p class="toc_h2"><a href="#5_3_video_decoding">5.3. Video Decoding</a> </p> 154 155 </div> 156 <div style="clear: both; page-break-after:always; height:1px"> 157 </div> 158 <div id="toc_left"> 159 <p class="toc_h3"><a href="#5_3_1_mpeg-2">5.3.1. MPEG-2</a> </p> 160 161 <p class="toc_h3"><a href="#5_3_2_h_263">5.3.2. H.263</a> </p> 162 163 <p class="toc_h3"><a href="#5_3_3_mpeg-4">5.3.3. MPEG-4</a> </p> 164 165 <p class="toc_h3"><a href="#5_3_4_h_264">5.3.4. H.264</a> </p> 166 167 <p class="toc_h3"><a href="#5_3_5_h_265_(hevc)">5.3.5. H.265 (HEVC)</a> </p> 168 169 <p class="toc_h3"><a href="#5_3_6_vp8">5.3.6. VP8</a> </p> 170 171 <p class="toc_h3"><a href="#5_3_7_vp9">5.3.7. VP9</a> </p> 172 173 <p class="toc_h2"><a href="#5_4_audio_recording">5.4. Audio Recording</a> </p> 174 175 <p class="toc_h3"><a href="#5_4_1_raw_audio_capture">5.4.1. Raw Audio Capture</a> </p> 176 177 <p class="toc_h3"><a href="#5_4_2_capture_for_voice_recognition">5.4.2. Capture for Voice Recognition</a> </p> 178 179 <p class="toc_h3"><a href="#5_4_3_capture_for_rerouting_of_playback">5.4.3. Capture for Rerouting of Playback</a> </p> 180 181 <p class="toc_h2"><a href="#5_5_audio_playback">5.5. Audio Playback</a> </p> 182 183 <p class="toc_h3"><a href="#5_5_1_raw_audio_playback">5.5.1. Raw Audio Playback</a> </p> 184 185 <p class="toc_h3"><a href="#5_5_2_audio_effects">5.5.2. Audio Effects</a> </p> 186 187 <p class="toc_h3"><a href="#5_5_3_audio_output_volume">5.5.3. Audio Output Volume</a> </p> 188 189 <p class="toc_h2"><a href="#5_6_audio_latency">5.6. Audio Latency</a> </p> 190 191 <p class="toc_h2"><a href="#5_7_network_protocols">5.7. Network Protocols</a> </p> 192 193 <p class="toc_h2"><a href="#5_8_secure_media">5.8. Secure Media</a> </p> 194 195 <p class="toc_h2"><a href="#5_9_musical_instrument_digital_interface_(midi)">5.9. Musical Instrument Digital Interface (MIDI)</a> </p> 196 197 <p class="toc_h2"><a href="#5_10_professional_audio">5.10. Professional Audio</a> </p> 198 199 <p class="toc_h2"><a href="#5_11_capture_for_unprocessed">5.11. Capture for Unprocessed</a> </p> 200 201 <p class="toc_h1"><a href="#6_developer_tools_and_options_compatibility">6. Developer Tools and Options Compatibility</a> </p> 202 203 <p class="toc_h2"><a href="#6_1_developer_tools">6.1. Developer Tools</a> </p> 204 205 <p class="toc_h2"><a href="#6_2_developer_options">6.2. Developer Options</a> </p> 206 207 <p class="toc_h1"><a href="#7_hardware_compatibility">7. Hardware Compatibility</a> </p> 208 209 <p class="toc_h2"><a href="#7_1_display_and_graphics">7.1. Display and Graphics</a> </p> 210 211 <p class="toc_h3"><a href="#7_1_1_screen_configuration">7.1.1. Screen Configuration</a> </p> 212 213 <p class="toc_h4"><a href="#7_1_1_1_screen_size">7.1.1.1. Screen Size</a> </p> 214 215 <p class="toc_h4"><a href="#7_1_1_2_screen_aspect_ratio">7.1.1.2. Screen Aspect Ratio</a> </p> 216 217 <p class="toc_h4"><a href="#7_1_1_3_screen_density">7.1.1.3. Screen Density</a> </p> 218 219 <p class="toc_h3"><a href="#7_1_2_display_metrics">7.1.2. Display Metrics</a> </p> 220 221 <p class="toc_h3"><a href="#7_1_3_screen_orientation">7.1.3. Screen Orientation</a> </p> 222 223 <p class="toc_h3"><a href="#7_1_4_2d_and_3d_graphics_acceleration">7.1.4. 2D and 3D Graphics Acceleration</a> </p> 224 225 <p class="toc_h3"><a href="#7_1_5_legacy_application_compatibility_mode">7.1.5. Legacy Application Compatibility Mode</a> </p> 226 227 </div> 228 <div id="toc_right"> 229 <p class="toc_h3"><a href="#7_1_6_screen_technology">7.1.6. Screen Technology</a> </p> 230 231 <p class="toc_h3"><a href="#7_1_7_secondary_displays">7.1.7. Secondary Displays</a> </p> 232 233 <p class="toc_h2"><a href="#7_2_input_devices">7.2. Input Devices</a> </p> 234 235 <p class="toc_h3"><a href="#7_2_1_keyboard">7.2.1. Keyboard</a> </p> 236 237 <p class="toc_h3"><a href="#7_2_2_non_touch_navigation">7.2.2. Non-touch Navigation</a> </p> 238 239 <p class="toc_h3"><a href="#7_2_3_navigation_keys">7.2.3. Navigation Keys</a> </p> 240 241 <p class="toc_h3"><a href="#7_2_4_touchscreen_input">7.2.4. Touchscreen Input</a> </p> 242 243 <p class="toc_h3"><a href="#7_2_5_fake_touch_input">7.2.5. Fake Touch Input</a> </p> 244 245 <p class="toc_h3"><a href="#7_2_6_game_controller_support">7.2.6. Game Controller Support</a> </p> 246 247 <p class="toc_h4"><a href="#7_2_6_1_button_mappings">7.2.6.1. Button Mappings</a> </p> 248 249 <p class="toc_h3"><a href="#7_2_7_remote_control">7.2.7. Remote Control</a> </p> 250 251 <p class="toc_h2"><a href="#7_3_sensors">7.3. Sensors</a> </p> 252 253 <p class="toc_h3"><a href="#7_3_1_accelerometer">7.3.1. Accelerometer</a> </p> 254 255 <p class="toc_h3"><a href="#7_3_2_magnetometer">7.3.2. Magnetometer</a> </p> 256 257 <p class="toc_h3"><a href="#7_3_3_gps">7.3.3. GPS</a> </p> 258 259 <p class="toc_h3"><a href="#7_3_4_gyroscope">7.3.4. Gyroscope</a> </p> 260 261 <p class="toc_h3"><a href="#7_3_5_barometer">7.3.5. Barometer</a> </p> 262 263 <p class="toc_h3"><a href="#7_3_6_thermometer">7.3.6. Thermometer</a> </p> 264 265 <p class="toc_h3"><a href="#7_3_7_photometer">7.3.7. Photometer</a> </p> 266 267 <p class="toc_h3"><a href="#7_3_8_proximity_sensor">7.3.8. Proximity Sensor</a> </p> 268 269 <p class="toc_h3"><a href="#7_3_9_high_fidelity_sensors">7.3.9. High Fidelity Sensors</a> </p> 270 271 <p class="toc_h3"><a href="#7_3_10_fingerprint_sensor">7.3.10. Fingerprint Sensor</a> </p> 272 273 <p class="toc_h3"><a href="#7_3_11_android_automotive-only_sensors">7.3.11. Android Automotive-only sensors</a> </p> 274 275 <p class="toc_h4"><a href="#7_3_11_1_current_gear">7.3.11.1. Current Gear</a> </p> 276 277 <p class="toc_h4"><a href="#7_3_11_2_day_night_mode">7.3.11.2. Day Night Mode</a> </p> 278 279 <p class="toc_h4"><a href="#7_3_11_3_driving_status">7.3.11.3. Driving Status</a> </p> 280 281 <p class="toc_h4"><a href="#7_3_11_4_wheel_speed">7.3.11.4. Wheel Speed</a> </p> 282 283 <p class="toc_h2"><a href="#7_3_12_pose_sensor">7.3.12. Pose Sensor</a> </p> 284 285 <p class="toc_h2"><a href="#7_4_data_connectivity">7.4. Data Connectivity</a> </p> 286 287 <p class="toc_h3"><a href="#7_4_1_telephony">7.4.1. Telephony</a> </p> 288 289 <p class="toc_h4"><a href="#7_4_1_1_number_blocking_compatibility">7.4.1.1. Number Blocking Compatibility</a> </p> 290 291 <p class="toc_h3"><a href="#7_4_2_ieee_802_11_(wi-fi)">7.4.2. IEEE 802.11 (Wi-Fi)</a> </p> 292 293 <p class="toc_h4"><a href="#7_4_2_1_wi-fi_direct">7.4.2.1. Wi-Fi Direct</a> </p> 294 295 <p class="toc_h4"><a href="#7_4_2_2_wi-fi_tunneled_direct_link_setup">7.4.2.2. Wi-Fi Tunneled Direct Link Setup</a> </p> 296 297 </div> 298 <div style="clear: both; page-break-after:always; height:1px"> 299 </div> 300 <div id="toc_left"> 301 <p class="toc_h3"><a href="#7_4_3_bluetooth">7.4.3. Bluetooth</a> </p> 302 303 <p class="toc_h3"><a href="#7_4_4_near-field_communications">7.4.4. Near-Field Communications</a> </p> 304 305 <p class="toc_h3"><a href="#7_4_5_minimum_network_capability">7.4.5. Minimum Network Capability</a> </p> 306 307 <p class="toc_h3"><a href="#7_4_6_sync_settings">7.4.6. Sync Settings</a> </p> 308 309 <p class="toc_h3"><a href="#7_4_7_data_saver">7.4.7. Data Saver</a> </p> 310 311 <p class="toc_h2"><a href="#7_5_cameras">7.5. Cameras</a> </p> 312 313 <p class="toc_h3"><a href="#7_5_1_rear-facing_camera">7.5.1. Rear-Facing Camera</a> </p> 314 315 <p class="toc_h3"><a href="#7_5_2_front-facing_camera">7.5.2. Front-Facing Camera</a> </p> 316 317 <p class="toc_h3"><a href="#7_5_3_external_camera">7.5.3. External Camera</a> </p> 318 319 <p class="toc_h3"><a href="#7_5_4_camera_api_behavior">7.5.4. Camera API Behavior</a> </p> 320 321 <p class="toc_h3"><a href="#7_5_5_camera_orientation">7.5.5. Camera Orientation</a> </p> 322 323 <p class="toc_h2"><a href="#7_6_memory_and_storage">7.6. Memory and Storage</a> </p> 324 325 <p class="toc_h3"><a href="#7_6_1_minimum_memory_and_storage">7.6.1. Minimum Memory and Storage</a> </p> 326 327 <p class="toc_h3"><a href="#7_6_2_application_shared_storage">7.6.2. Application Shared Storage</a> </p> 328 329 <p class="toc_h3"><a href="#7_6_3_adoptable_storage">7.6.3. Adoptable Storage</a> </p> 330 331 <p class="toc_h2"><a href="#7_7_usb">7.7. USB</a> </p> 332 333 <p class="toc_h3"><a href="#7_7_1_usb_peripheral_mode">7.7.1. USB peripheral mode</a> </p> 334 335 <p class="toc_h3"><a href="#7_7_2_usb_host_mode">7.7.2. USB host mode</a> </p> 336 337 <p class="toc_h2"><a href="#7_8_audio">7.8. Audio</a> </p> 338 339 <p class="toc_h3"><a href="#7_8_1_microphone">7.8.1. Microphone</a> </p> 340 341 <p class="toc_h3"><a href="#7_8_2_audio_output">7.8.2. Audio Output</a> </p> 342 343 <p class="toc_h4"><a href="#7_8_2_1_analog_audio_ports">7.8.2.1. Analog Audio Ports</a> </p> 344 345 <p class="toc_h3"><a href="#7_8_3_near-ultrasound">7.8.3. Near-Ultrasound</a> </p> 346 347 <p class="toc_h2"><a href="#7_9_virtual_reality">7.9. Virtual Reality</a> </p> 348 349 <p class="toc_h3"><a href="#7_9_1_virtual_reality_mode">7.9.1. Virtual Reality Mode</a> </p> 350 351 <p class="toc_h3"><a href="#7_9_2_virtual_reality_high_performance">7.9.2. Virtual Reality High Performance</a> </p> 352 353 <p class="toc_h1"><a href="#8_performance_and_power">8. Performance and Power</a> </p> 354 355 <p class="toc_h2"><a href="#8_1_user_experience_consistency">8.1. User Experience Consistency</a> </p> 356 357 <p class="toc_h2"><a href="#8_2_file_i/o_access_performance">8.2. File I/O Access Performance</a> </p> 358 359 <p class="toc_h2"><a href="#8_3_power-saving_modes">8.3. Power-Saving Modes</a> </p> 360 361 <p class="toc_h2"><a href="#8_4_power_consumption_accounting">8.4. Power Consumption Accounting</a> </p> 362 363 <p class="toc_h2"><a href="#8_5_consistent_performance">8.5. Consistent Performance</a> </p> 364 365 <p class="toc_h1"><a href="#9_security_model_compatibility">9. Security Model Compatibility</a> </p> 366 367 <p class="toc_h2"><a href="#9_1_permissions">9.1. Permissions</a> </p> 368 369 </div> 370 <div id="toc_right"> 371 <p class="toc_h2"><a href="#9_2_uid_and_process_isolation">9.2. UID and Process Isolation</a> </p> 372 373 <p class="toc_h2"><a href="#9_3_filesystem_permissions">9.3. Filesystem Permissions</a> </p> 374 375 <p class="toc_h2"><a href="#9_4_alternate_execution_environments">9.4. Alternate Execution Environments</a> </p> 376 377 <p class="toc_h2"><a href="#9_5_multi-user_support">9.5. Multi-User Support</a> </p> 378 379 <p class="toc_h2"><a href="#9_6_premium_sms_warning">9.6. Premium SMS Warning</a> </p> 380 381 <p class="toc_h2"><a href="#9_7_kernel_security_features">9.7. Kernel Security Features</a> </p> 382 383 <p class="toc_h2"><a href="#9_8_privacy">9.8. Privacy</a> </p> 384 385 <p class="toc_h2"><a href="#9_9_data_storage_encryption">9.9. Data Storage Encryption</a> </p> 386 387 <p class="toc_h3"><a href="#9_9_1_direct_boot">9.9.1. Direct Boot</a> </p> 388 389 <p class="toc_h3"><a href="#9_9_2_file_based_encryption">9.9.2. File Based Encryption</a> </p> 390 391 <p class="toc_h3"><a href="#9_9_3_full_disk_encryption">9.9.3. Full Disk Encryption</a> </p> 392 393 <p class="toc_h2"><a href="#9_10_device_integrity">9.10. Device Integrity</a> </p> 394 395 <p class="toc_h2"><a href="#9_11_keys_and_credentials">9.11. Keys and Credentials</a> </p> 396 397 <p class="toc_h3"><a href="#9_11_1_secure_lock_screen">9.11.1. Secure Lock Screen</a> </p> 398 399 <p class="toc_h2"><a href="#9_12_data_deletion">9.12. Data Deletion</a> </p> 400 401 <p class="toc_h2"><a href="#9_13_safe_boot_mode">9.13. Safe Boot Mode</a> </p> 402 403 <p class="toc_h2"><a href="#9_14_automotive_vehicle_system_isolation">9.14. Automotive Vehicle System Isolation</a> </p> 404 405 <p class="toc_h1"><a href="#10_software_compatibility_testing">10. Software Compatibility Testing</a> </p> 406 407 <p class="toc_h2"><a href="#10_1_compatibility_test_suite">10.1. Compatibility Test Suite</a> </p> 408 409 <p class="toc_h2"><a href="#10_2_cts_verifier">10.2. CTS Verifier</a> </p> 410 411 <p class="toc_h1"><a href="#11_updatable_software">11. Updatable Software</a> </p> 412 413 <p class="toc_h1"><a href="#12_document_changelog">12. Document Changelog</a> </p> 414 415 <p class="toc_h2"><a href="#12_1_changelog_viewing_tips">12.1. Changelog Viewing Tips</a> </p> 416 417 <p class="toc_h1"><a href="#13_contact_us">13. Contact Us</a> </p> 418 419 </div> 420 <div style="clear: both; page-break-after:always; height:1px"> 421 </div> 422 <div style="clear: both"> 423 </div> 424 </div> 425 <div id="main"> 426 <h1 id="1_introduction"> 427 1. Introduction 428 </h1> 429 <p> 430 This document enumerates the requirements that must be met in order for devices 431to be compatible with Android 7.0. 432 </p> 433 <p> 434 The use of “MUST”, “MUST NOT”, “REQUIRED”, “SHALL”, “SHALL NOT”, “SHOULD”, 435“SHOULD NOT”, “RECOMMENDED”, “MAY”, and “OPTIONAL” is per the IETF standard 436defined in 437 <a href="http://www.ietf.org/rfc/rfc2119.txt">RFC2119</a>. 438 </p> 439 <p> 440 As used in this document, a “device implementer” or “implementer” is a person 441or organization developing a hardware/software solution running Android 4427.0. A “device implementation” or “implementation is the 443hardware/software solution so developed. 444 </p> 445 <p> 446 To be considered compatible with Android 7.0, device 447implementations MUST meet the requirements presented in this Compatibility 448Definition, including any documents incorporated via reference. 449 </p> 450 <p> 451 Where this definition or the software tests described in 452 <a href="#10_software_compatibility_testing"> 453 section 10</a> is silent, ambiguous, or incomplete, it 454is the responsibility of the device implementer to ensure compatibility with 455existing implementations. 456 </p> 457 <p> 458 For this reason, the 459 <a href="http://source.android.com/">Android Open Source Project</a> is both the reference and preferred implementation of Android. Device 460implementers are STRONGLY RECOMMENDED to base their implementations to the 461greatest extent possible on the “upstream” source code available from the 462Android Open Source Project. While some components can hypothetically be 463replaced with alternate implementations, it is STRONGLY RECOMMENDED to not 464follow this practice, as passing the software tests will become substantially 465more difficult. It is the implementer’s responsibility to ensure full 466behavioral compatibility with the standard Android implementation, including 467and beyond the Compatibility Test Suite. Finally, note that certain component 468substitutions and modifications are explicitly forbidden by this document. 469 </p> 470 <p> 471 Many of the resources linked to in this document are derived directly or 472indirectly from the Android SDK and will be functionally identical to the 473information in that SDK’s documentation. In any cases where this Compatibility 474Definition or the Compatibility Test Suite disagrees with the SDK 475documentation, the SDK documentation is considered authoritative. Any technical 476details provided in the linked resources throughout this document are 477considered by inclusion to be part of this Compatibility Definition. 478 </p> 479 <h1 id="2_device_types"> 480 2. Device Types 481 </h1> 482 <p> 483 While the Android Open Source Project has been used in the implementation of a 484variety of device types and form factors, many aspects of the architecture and 485compatibility requirements were optimized for handheld devices. Starting from 486Android 5.0, the Android Open Source Project aims to embrace a wider variety of 487device types as described in this section. 488 </p> 489 <p> 490 <strong> 491 Android Handheld device 492 </strong> 493 refers to an Android device implementation that is 494typically used by holding it in the hand, such as mp3 players, phones, and 495tablets. Android Handheld device implementations: 496 </p> 497 <ul> 498 <li> 499 MUST have a touchscreen embedded in the device. 500 </li> 501 <li> 502 MUST have a power source that provides mobility, such as a battery. 503 </li> 504 </ul> 505 <p> 506 <strong> 507 Android Television device 508 </strong> 509 refers to an Android device implementation that 510is an entertainment interface for consuming digital media, movies, games, apps, 511and/or live TV for users sitting about ten feet away (a “lean back” or “10-foot 512user interface”). Android Television devices: 513 </p> 514 <ul> 515 <li> 516 MUST have an embedded screen OR include a video output port, such as VGA, 517 HDMI, or a wireless port for display. 518 </li> 519 <li> 520 MUST declare the features 521 <a href="http://developer.android.com/reference/android/content/pm/PackageManager.html#FEATURE_LEANBACK">android.software.leanback</a> and android.hardware.type.television. 522 </li> 523 </ul> 524 <p> 525 <strong> 526 Android Watch device 527 </strong> 528 refers to an Android device implementation intended to 529be worn on the body, perhaps on the wrist, and: 530 </p> 531 <ul> 532 <li> 533 MUST have a screen with the physical diagonal length in the range from 1.1 534 to 2.5 inches. 535 </li> 536 <li> 537 MUST declare the feature android.hardware.type.watch. 538 </li> 539 <li> 540 MUST support uiMode = 541 <a href="http://developer.android.com/reference/android/content/res/Configuration.html#UI_MODE_TYPE_WATCH">UI_MODE_TYPE_WATCH</a>. 542 </li> 543 </ul> 544 <p> 545 <strong> 546 Android Automotive implementation 547 </strong> 548 refers to a vehicle head unit running 549Android as an operating system for part or all of the system and/or 550infotainment functionality. Android Automotive implementations: 551 </p> 552 <ul> 553 <li> 554 MUST have a screen with the physical diagonal length equal to or greater 555 than 6 inches. 556 </li> 557 <li> 558 MUST declare the feature android.hardware.type.automotive. 559 </li> 560 <li> 561 MUST support uiMode = 562 <a href="http://developer.android.com/reference/android/content/res/Configuration.html#UI_MODE_TYPE_CAR">UI_MODE_TYPE_CAR</a>. 563 </li> 564 <li> 565 Android Automotive implementations MUST support all public APIs in the 566 <code> 567 android.car.* 568 </code> 569 namespace. 570 </li> 571 </ul> 572 <p> 573 All Android device implementations that do not fit into any of the above device 574types still MUST meet all requirements in this document to be Android 5757.0 compatible, unless the requirement is explicitly described to 576be only applicable to a specific Android device type from above. 577 </p> 578 <h2 id="2_1_device_configurations"> 579 2.1 Device Configurations 580 </h2> 581 <p> 582 This is a summary of major differences in hardware configuration by device 583type. (Empty cells denote a “MAY”). Not all configurations are covered in this 584table; see relevant hardware sections for more detail. 585 </p> 586 <table> 587 <tr> 588 <th> 589 Category 590 </th> 591 <th> 592 Feature 593 </th> 594 <th> 595 Section 596 </th> 597 <th> 598 Handheld 599 </th> 600 <th> 601 Television 602 </th> 603 <th> 604 Watch 605 </th> 606 <th> 607 Automotive 608 </th> 609 <th> 610 Other 611 </th> 612 </tr> 613 <tr> 614 <td rowspan="3"> 615 Input 616 </td> 617 <td> 618 D-pad 619 </td> 620 <td> 621 <a href="#7_2_2_non_touch_navigation">7.2.2. Non-touch Navigation</a> </td> 622 <td> 623 </td> 624 <td> 625 MUST 626 </td> 627 <td> 628 </td> 629 <td> 630 </td> 631 <td> 632 </td> 633 </tr> 634 <tr> 635 <td> 636 Touchscreen 637 </td> 638 <td> 639 <a href="#7_2_4_touchscreen_input">7.2.4. Touchscreen input</a> </td> 640 <td> 641 MUST 642 </td> 643 <td> 644 </td> 645 <td> 646 MUST 647 </td> 648 <td> 649 </td> 650 <td> 651 SHOULD 652 </td> 653 </tr> 654 <tr> 655 <td> 656 Microphone 657 </td> 658 <td> 659 <a href="#7_8_1_microphone">7.8.1. Microphone</a> </td> 660 <td> 661 MUST 662 </td> 663 <td> 664 SHOULD 665 </td> 666 <td> 667 MUST 668 </td> 669 <td> 670 MUST 671 </td> 672 <td> 673 SHOULD 674 </td> 675 </tr> 676 <tr> 677 <td rowspan="2"> 678 Sensors 679 </td> 680 <td> 681 Accelerometer 682 </td> 683 <td> 684 <a href="#7_3_1_accelerometer">7.3.1 Accelerometer</a> </td> 685 <td> 686 SHOULD 687 </td> 688 <td> 689 </td> 690 <td> 691 SHOULD 692 </td> 693 <td> 694 </td> 695 <td> 696 SHOULD 697 </td> 698 </tr> 699 <tr> 700 <td> 701 GPS 702 </td> 703 <td> 704 <a href="#7_3_3_gps">7.3.3. GPS</a> </td> 705 <td> 706 SHOULD 707 </td> 708 <td> 709 </td> 710 <td> 711 </td> 712 <td> 713 SHOULD 714 </td> 715 <td> 716 </td> 717 </tr> 718 <tr> 719 <td rowspan="6"> 720 Connectivity 721 </td> 722 <td> 723 Wi-Fi 724 </td> 725 <td> 726 <a href="#7_4_2_ieee_802.11">7.4.2. IEEE 802.11</a> </td> 727 <td> 728 SHOULD 729 </td> 730 <td> 731 SHOULD 732 </td> 733 <td> 734 </td> 735 <td> 736 SHOULD 737 </td> 738 <td> 739 SHOULD 740 </td> 741 </tr> 742 <tr> 743 <td> 744 Wi-Fi Direct 745 </td> 746 <td> 747 <a href="#7_4_2_1_wi-fi-direct">7.4.2.1. Wi-Fi Direct</a> </td> 748 <td> 749 SHOULD 750 </td> 751 <td> 752 SHOULD 753 </td> 754 <td> 755 </td> 756 <td> 757 </td> 758 <td> 759 SHOULD 760 </td> 761 </tr> 762 <tr> 763 <td> 764 Bluetooth 765 </td> 766 <td> 767 <a href="#7_4_3_bluetooth">7.4.3. Bluetooth</a> </td> 768 <td> 769 SHOULD 770 </td> 771 <td> 772 MUST 773 </td> 774 <td> 775 MUST 776 </td> 777 <td> 778 MUST 779 </td> 780 <td> 781 SHOULD 782 </td> 783 </tr> 784 <tr> 785 <td> 786 Bluetooth Low Energy 787 </td> 788 <td> 789 <a href="#7_4_3_bluetooth">7.4.3. Bluetooth</a> </td> 790 <td> 791 SHOULD 792 </td> 793 <td> 794 MUST 795 </td> 796 <td> 797 SHOULD 798 </td> 799 <td> 800 SHOULD 801 </td> 802 <td> 803 SHOULD 804 </td> 805 </tr> 806 <tr> 807 <td> 808 Cellular radio 809 </td> 810 <td> 811 <a href="#7_4_5_minimum_network_capability">7.4.5. Minimum Network Capability</a> </td> 812 <td> 813 </td> 814 <td> 815 </td> 816 <td> 817 </td> 818 <td> 819 SHOULD 820 </td> 821 <td> 822 </td> 823 </tr> 824 <tr> 825 <td> 826 USB peripheral/host mode 827 </td> 828 <td> 829 <a href="#7_7_usb">7.7. USB</a> </td> 830 <td> 831 SHOULD 832 </td> 833 <td> 834 </td> 835 <td> 836 </td> 837 <td> 838 SHOULD 839 </td> 840 <td> 841 SHOULD 842 </td> 843 </tr> 844 <tr> 845 <td> 846 Output 847 </td> 848 <td> 849 Speaker and/or Audio output ports 850 </td> 851 <td> 852 <a href="#7_8_2_audio_output">7.8.2. Audio Output</a> </td> 853 <td> 854 MUST 855 </td> 856 <td> 857 MUST 858 </td> 859 <td> 860 </td> 861 <td> 862 MUST 863 </td> 864 <td> 865 MUST 866 </td> 867 </tr> 868 </table> 869 <h1 id="3_software"> 870 3. Software 871 </h1> 872 <h2 id="3_1_managed_api_compatibility"> 873 3.1. Managed API Compatibility 874 </h2> 875 <p> 876 The managed Dalvik bytecode execution environment is the primary vehicle for 877Android applications. The Android application programming interface (API) is the 878set of Android platform interfaces exposed to applications running in the 879managed runtime environment. Device implementations MUST provide complete 880implementations, including all documented behaviors, of any documented API 881exposed by the 882 <a href="http://developer.android.com/reference/packages.html"> 883 Android SDK</a> or any API decorated 884with the “@SystemApi” marker in the upstream Android source code. 885 </p> 886 <p> 887 Device implementations MUST support/preserve all classes, methods, and 888associated elements marked by the TestApi annotation (@TestApi). 889 </p> 890 <p> 891 Device implementations MUST NOT omit any managed APIs, alter API interfaces or 892signatures, deviate from the documented behavior, or include no-ops, except 893where specifically allowed by this Compatibility Definition. 894 </p> 895 <p> 896 This Compatibility Definition permits some types of hardware for which Android 897includes APIs to be omitted by device implementations. In such cases, the APIs 898MUST still be present and behave in a reasonable way. See 899 <a href="#7_hardware_compatibility"> 900 section 7</a> for specific requirements for this scenario. 901 </p> 902 <h2 id="3_1_1_android_extensions"> 903 3.1.1. Android Extensions 904 </h2> 905 <p> 906 Android includes the support of extending the managed APIs while keeping the same API 907level version. Android device implementations MUST preload the AOSP implementation 908of both the shared library 909 <code> 910 ExtShared 911 </code> 912 and services 913 <code> 914 ExtServices 915 </code> 916 with versions higher 917than or equal to the minimum versions allowed per each API level. 918For example, Android 7.0 device implementations, running API level 24 MUST include 919at least version 1. 920 </p> 921 <h2 id="3_2_soft_api_compatibility"> 922 3.2. Soft API Compatibility 923 </h2> 924 <p> 925 In addition to the managed APIs from 926 <a href="#3_1_managed_api_compatibility"> 927 section 3.1</a>, Android also includes a significant 928runtime-only “soft” API, in the form of such things as intents, permissions, 929and similar aspects of Android applications that cannot be enforced at 930application compile time. 931 </p> 932 <h3 id="3_2_1_permissions"> 933 3.2.1. Permissions 934 </h3> 935 <p> 936 Device implementers MUST support and enforce all permission constants as 937documented by the 938 <a href="http://developer.android.com/reference/android/Manifest.permission.html"> 939 Permission reference page</a>. 940Note that 941 <a href="#9_security_model_compatibility">section 9</a> lists additional 942requirements related to the Android security model. 943 </p> 944 <h3 id="3_2_2_build_parameters"> 945 3.2.2. Build Parameters 946 </h3> 947 <p> 948 The Android APIs include a number of constants on the 949 <a href="http://developer.android.com/reference/android/os/Build.html"> 950 android.os.Build 951class 952 </a> 953 that are 954intended to describe the current device. To provide consistent, meaningful 955values across device implementations, the table below includes additional 956restrictions on the formats of these values to which device implementations 957MUST conform. 958 </p> 959 <table> 960 <tr> 961 <th> 962 Parameter 963 </th> 964 <th> 965 Details 966 </th> 967 </tr> 968 <tr> 969 <td> 970 VERSION.RELEASE 971 </td> 972 <td> 973 The version of the currently-executing Android system, in human-readable 974 format. This field MUST have one of the string values defined in 975 <a href="http://source.android.com/compatibility/7.0/versions.html">7.0</a>. 976 </td> 977 </tr> 978 <tr> 979 <td> 980 VERSION.SDK 981 </td> 982 <td> 983 The version of the currently-executing Android system, in a format 984 accessible to third-party application code. For Android 7.0, 985 this field MUST have the integer value 7.0_INT. 986 </td> 987 </tr> 988 <tr> 989 <td> 990 VERSION.SDK_INT 991 </td> 992 <td> 993 The version of the currently-executing Android system, in a format 994 accessible to third-party application code. For Android 7.0, 995 this field MUST have the integer value 7.0_INT. 996 </td> 997 </tr> 998 <tr> 999 <td> 1000 VERSION.INCREMENTAL 1001 </td> 1002 <td> 1003 A value chosen by the device implementer designating the specific build 1004 of the currently-executing Android system, in human-readable format. This 1005 value MUST NOT be reused for different builds made available to end users. A 1006 typical use of this field is to indicate which build number or 1007 source-control change identifier was used to generate the build. There are 1008 no requirements on the specific format of this field, except that it MUST 1009 NOT be null or the empty string (""). 1010 </td> 1011 </tr> 1012 <tr> 1013 <td> 1014 BOARD 1015 </td> 1016 <td> 1017 A value chosen by the device implementer identifying the specific 1018 internal hardware used by the device, in human-readable format. A possible 1019 use of this field is to indicate the specific revision of the board powering 1020 the device. The value of this field MUST be encodable as 7-bit ASCII and 1021 match the regular expression “^[a-zA-Z0-9_-]+$”. 1022 </td> 1023 </tr> 1024 <tr> 1025 <td> 1026 BRAND 1027 </td> 1028 <td> 1029 A value reflecting the brand name associated with the device as known to 1030 the end users. MUST be in human-readable format and SHOULD represent the 1031 manufacturer of the device or the company brand under which the device is 1032 marketed. The value of this field MUST be encodable as 7-bit ASCII and match 1033 the regular expression “^[a-zA-Z0-9_-]+$”. 1034 </td> 1035 </tr> 1036 <tr> 1037 <td> 1038 SUPPORTED_ABIS 1039 </td> 1040 <td> 1041 The name of the instruction set (CPU type + ABI convention) of native 1042 code. See 1043 <a href="#3_3_native_api_compatibility"> section 3.3. Native API Compatibility</a>. 1044 </td> 1045 </tr> 1046 <tr> 1047 <td> 1048 SUPPORTED_32_BIT_ABIS 1049 </td> 1050 <td> 1051 The name of the instruction set (CPU type + ABI convention) of native 1052 code. See <a href="#3_3_native_api_compatibility"> section 3.3. Native API Compatibility</a>. 1053 </td> 1054 </tr> 1055 <tr> 1056 <td> 1057 SUPPORTED_64_BIT_ABIS 1058 </td> 1059 <td> 1060 The name of the second instruction set (CPU type + ABI convention) of 1061 native code. See 1062 <a href="#3_3_native_api_compatibility"> section 3.3. Native API Compatibility</a>. 1063 </td> 1064 </tr> 1065 <tr> 1066 <td> 1067 CPU_ABI 1068 </td> 1069 <td> 1070 The name of the instruction set (CPU type + ABI convention) of native 1071 code. See 1072 <a href="#3_3_native_api_compatibility"> section 3.3. Native API Compatibility</a>. 1073 </td> 1074 </tr> 1075 <tr> 1076 <td> 1077 CPU_ABI2 1078 </td> 1079 <td> 1080 The name of the second instruction set (CPU type + ABI convention) of 1081 native code. See 1082 <a href="#3_3_native_api_compatibility"> section 3.3. Native API Compatibility</a>. 1083 </td> 1084 </tr> 1085 <tr> 1086 <td> 1087 DEVICE 1088 </td> 1089 <td> 1090 A value chosen by the device implementer containing the development name 1091 or code name identifying the configuration of the hardware features and 1092 industrial design of the device. The value of this field MUST be encodable 1093 as 7-bit ASCII and match the regular expression 1094 “^[a-zA-Z0-9_-]+$”. This device name MUST NOT change during the 1095 lifetime of the product. 1096 </td> 1097 </tr> 1098 <tr> 1099 <td> 1100 FINGERPRINT 1101 </td> 1102 <td> 1103 A string that uniquely identifies this build. It SHOULD be reasonably 1104 human-readable. It MUST follow this template: 1105 <p class="small"> 1106 $(BRAND)/$(PRODUCT)/ 1107 <br/> 1108 $(DEVICE):$(VERSION.RELEASE)/$(ID)/$(VERSION.INCREMENTAL):$(TYPE)/$(TAGS) 1109 </p> 1110 <p> 1111 For example: 1112 </p> 1113 <p class="small"> 1114 acme/myproduct/ 1115 <br/> 1116 mydevice:7.0/LMYXX/3359:userdebug/test-keys 1117 </p> 1118 <p> 1119 The fingerprint MUST NOT include whitespace characters. If other fields 1120 included in the template above have whitespace characters, they MUST be 1121 replaced in the build fingerprint with another character, such as the 1122 underscore ("_") character. The value of this field MUST be encodable as 1123 7-bit ASCII. 1124 </p> 1125 </td> 1126 </tr> 1127 <tr> 1128 <td> 1129 HARDWARE 1130 </td> 1131 <td> 1132 The name of the hardware (from the kernel command line or /proc). It 1133 SHOULD be reasonably human-readable. The value of this field MUST be 1134 encodable as 7-bit ASCII and match the regular expression 1135 “^[a-zA-Z0-9_-]+$”. 1136 </td> 1137 </tr> 1138 <tr> 1139 <td> 1140 HOST 1141 </td> 1142 <td> 1143 A string that uniquely identifies the host the build was built on, in 1144 human-readable format. There are no requirements on the specific format of 1145 this field, except that it MUST NOT be null or the empty string (""). 1146 </td> 1147 </tr> 1148 <tr> 1149 <td> 1150 ID 1151 </td> 1152 <td> 1153 An identifier chosen by the device implementer to refer to a specific 1154 release, in human-readable format. This field can be the same as 1155 android.os.Build.VERSION.INCREMENTAL, but SHOULD be a value sufficiently 1156 meaningful for end users to distinguish between software builds. The value 1157 of this field MUST be encodable as 7-bit ASCII and match the regular 1158 expression “^[a-zA-Z0-9._-]+$”. 1159 </td> 1160 </tr> 1161 <tr> 1162 <td> 1163 MANUFACTURER 1164 </td> 1165 <td> 1166 The trade name of the Original Equipment Manufacturer (OEM) of the 1167 product. There are no requirements on the specific format of this field, 1168 except that it MUST NOT be null or the empty string (""). 1169 </td> 1170 </tr> 1171 <tr> 1172 <td> 1173 MODEL 1174 </td> 1175 <td> 1176 A value chosen by the device implementer containing the name of the 1177 device as known to the end user. This SHOULD be the same name under which 1178 the device is marketed and sold to end users. There are no requirements on 1179 the specific format of this field, except that it MUST NOT be null or the 1180 empty string (""). 1181 </td> 1182 </tr> 1183 <tr> 1184 <td> 1185 PRODUCT 1186 </td> 1187 <td> 1188 A value chosen by the device implementer containing the development name 1189 or code name of the specific product (SKU) that MUST be unique within the 1190 same brand. MUST be human-readable, but is not necessarily intended for view 1191 by end users. The value of this field MUST be encodable as 7-bit ASCII and 1192 match the regular expression “^[a-zA-Z0-9_-]+$”. This product 1193 name MUST NOT change during the lifetime of the product. 1194 </td> 1195 </tr> 1196 <tr> 1197 <td> 1198 SERIAL 1199 </td> 1200 <td> 1201 A hardware serial number, which MUST be available and unique across 1202 devices with the same MODEL and MANUFACTURER. The value of this field MUST 1203 be encodable as 7-bit ASCII and match the regular expression 1204 “^([a-zA-Z0-9]{6,20})$”. 1205 </td> 1206 </tr> 1207 <tr> 1208 <td> 1209 TAGS 1210 </td> 1211 <td> 1212 A comma-separated list of tags chosen by the device implementer that 1213 further distinguishes the build. This field MUST have one of the values 1214 corresponding to the three typical Android platform signing configurations: 1215 release-keys, dev-keys, test-keys. 1216 </td> 1217 </tr> 1218 <tr> 1219 <td> 1220 TIME 1221 </td> 1222 <td> 1223 A value representing the timestamp of when the build occurred. 1224 </td> 1225 </tr> 1226 <tr> 1227 <td> 1228 TYPE 1229 </td> 1230 <td> 1231 A value chosen by the device implementer specifying the runtime 1232 configuration of the build. This field MUST have one of the values 1233 corresponding to the three typical Android runtime configurations: user, 1234 userdebug, or eng. 1235 </td> 1236 </tr> 1237 <tr> 1238 <td> 1239 USER 1240 </td> 1241 <td> 1242 A name or user ID of the user (or automated user) that generated the 1243 build. There are no requirements on the specific format of this field, 1244 except that it MUST NOT be null or the empty string (""). 1245 </td> 1246 </tr> 1247 <tr> 1248 <td> 1249 SECURITY_PATCH 1250 </td> 1251 <td> 1252 A value indicating the security patch level of a build. It MUST signify 1253 that the build includes all security patches issued up through the 1254 designated Android Public Security Bulletin. It MUST be in the format 1255 [YYYY-MM-DD], matching one of the Android Security Patch Level strings of 1256 the 1257 <a href="source.android.com/security/bulletin"> 1258 Public Security 1259 Bulletins 1260 </a> 1261 , for example "2015-11-01". 1262 </td> 1263 </tr> 1264 <tr> 1265 <td> 1266 BASE_OS 1267 </td> 1268 <td> 1269 A value representing the FINGERPRINT parameter of the build that is 1270 otherwise identical to this build except for the patches provided in the 1271 Android Public Security Bulletin. It MUST report the correct value and if 1272 such a build does not exist, report an empty string (""). 1273 </td> 1274 </tr> 1275 </table> 1276 <h3 id="3_2_3_intent_compatibility"> 1277 3.2.3. Intent Compatibility 1278 </h3> 1279 <h4 id="3_2_3_1_core_application_intents"> 1280 3.2.3.1. Core Application Intents 1281 </h4> 1282 <p> 1283 Android intents allow application components to request functionality from 1284other Android components. The Android upstream project includes a list of 1285applications considered core Android applications, which implements several 1286intent patterns to perform common actions. The core Android applications are: 1287 </p> 1288 <ul> 1289 <li> 1290 Desk Clock 1291 </li> 1292 <li> 1293 Browser 1294 </li> 1295 <li> 1296 Calendar 1297 </li> 1298 <li> 1299 Contacts 1300 </li> 1301 <li> 1302 Gallery 1303 </li> 1304 <li> 1305 GlobalSearch 1306 </li> 1307 <li> 1308 Launcher 1309 </li> 1310 <li> 1311 Music 1312 </li> 1313 <li> 1314 Settings 1315 </li> 1316 </ul> 1317 <p> 1318 Device implementations MUST include the core Android applications as 1319appropriate or a component implementing the same intent patterns defined by 1320all the Activity or Service components of these core Android applications 1321exposed to other applications, implicitly or explicitly, through the 1322 <code> 1323 android:exported 1324 </code> 1325 attribute. 1326 </p> 1327 <h4 id="3_2_3_2_intent_resolution"> 1328 3.2.3.2. Intent Resolution 1329 </h4> 1330 <p> 1331 As Android is an extensible platform, device implementations MUST allow each 1332intent pattern referenced in 1333 <a href="#3_2_3_1_core_application_intents">section 3.2.3.1</a> 1334 to be overridden by third-party 1335applications. The upstream Android open source implementation allows this by 1336default; device implementers MUST NOT attach special privileges to system 1337applications' use of these intent patterns, or prevent third-party applications 1338from binding to and assuming control of these patterns. This prohibition 1339specifically includes but is not limited to disabling the “Chooser” user 1340interface that allows the user to select between multiple applications that all 1341handle the same intent pattern. 1342 </p> 1343 <p> 1344 Device implementations MUST provide a user interface for users to modify the 1345default activity for intents. 1346 </p> 1347 <p> 1348 However, device implementations MAY provide default activities for specific URI 1349patterns (e.g. http://play.google.com) when the default activity provides a 1350more specific attribute for the data URI. For example, an intent filter pattern 1351specifying the data URI “http://www.android.com” is more specific than the 1352browser's core intent pattern for “http://”. 1353 </p> 1354 <p> 1355 Android also includes a mechanism for third-party apps to declare an 1356authoritative default 1357 <a href="https://developer.android.com/training/app-links">app linking behavior</a> 1358 for certain types 1359of web URI intents. When such authoritative declarations are defined in an 1360app's intent filter patterns, device implementations: 1361 </p> 1362 <ul> 1363 <li> 1364 MUST attempt to validate any intent filters by performing the validation 1365steps defined in the 1366 <a href="https://developers.google.com/digital-asset-links">Digital Asset Links specification</a> as 1367implemented by the Package Manager in the upstream Android Open Source 1368Project. 1369 </li> 1370 <li> 1371 MUST attempt validation of the intent filters during the installation of 1372the application and set all successfully validated UIR intent filters as 1373default app handlers for their UIRs. 1374 </li> 1375 <li> 1376 MAY set specific URI intent filters as default app handlers for their URIs, 1377if they are successfully verified but other candidate URI filters fail 1378verification. If a device implementation does this, it MUST provide the 1379user appropriate per-URI pattern overrides in the settings menu. 1380 </li> 1381 <li> 1382 MUST provide the user with per-app App Links controls in Settings as 1383follows: 1384 <ul> 1385 <li> 1386 The user MUST be able to override holistically the default app links 1387behavior for an app to be: always open, always ask, or never open, 1388which must apply to all candidate URI intent filters equally. 1389 </li> 1390 <li> 1391 The user MUST be able to see a list of the candidate URI intent filters. 1392 </li> 1393 <li> 1394 The device implementation MAY provide the user with the ability to 1395override specific candidate URI intent filters that were successfully 1396verified, on a per-intent filter basis. 1397 </li> 1398 <li> 1399 The device implementation MUST provide users with the ability to view 1400and override specific candidate URI intent filters if the device 1401implementation lets some candidate URI intent filters succeed 1402verification while some others can fail. 1403 </li> 1404 </ul> 1405 </li> 1406 </ul> 1407 <h4 id="3_2_3_3_intent_namespaces"> 1408 3.2.3.3. Intent Namespaces 1409 </h4> 1410 <p> 1411 Device implementations MUST NOT include any Android component that honors any 1412new intent or broadcast intent patterns using an ACTION, CATEGORY, or other key 1413string in the android. 1414 <em> 1415 or com.android. 1416 </em> 1417 namespace. Device implementers MUST 1418NOT include any Android components that honor any new intent or broadcast 1419intent patterns using an ACTION, CATEGORY, or other key string in a package 1420space belonging to another organization. Device implementers MUST NOT alter or 1421extend any of the intent patterns used by the core apps listed in 1422 <a href="#3_2_3_1_core_application_intents">section 3.2.3.1</a>. Device implementations MAY include 1423intent patterns using namespaces clearly and obviously associated with their 1424own organization. This prohibition is analogous to that specified for Java 1425language classes in 1426 <a href="#3_6_api_namespaces">section 3.6</a>. 1427 </p> 1428 <h4 id="3_2_3_4_broadcast_intents"> 1429 3.2.3.4. Broadcast Intents 1430 </h4> 1431 <p> 1432 Third-party applications rely on the platform to broadcast certain intents to 1433notify them of changes in the hardware or software environment. 1434Android-compatible devices MUST broadcast the public broadcast intents in 1435response to appropriate system events. Broadcast intents are described in the 1436SDK documentation. 1437 </p> 1438 <h4 id="3_2_3_5_default_app_settings"> 1439 3.2.3.5. Default App Settings 1440 </h4> 1441 <p> 1442 Android includes settings that provide users an easy way to select their 1443default applications, for example for Home screen or SMS. Where it makes sense, 1444device implementations MUST provide a similar settings menu and be compatible 1445with the intent filter pattern and API methods described in the SDK 1446documentation as below. 1447 </p> 1448 <p> 1449 Device implementations: 1450 </p> 1451 <ul> 1452 <li> 1453 MUST honor the 1454 <a href="http://developer.android.com/reference/android/provider/Settings.html#ACTION_HOME_SETTINGS">android.settings.HOME_SETTINGS</a> intent to show a default app settings menu for Home Screen, if the device 1455implementation reports android.software.home_screen. 1456 </li> 1457 <li> 1458 MUST provide a settings menu that will call the 1459 <a href="http://developer.android.com/reference/android/provider/Telephony.Sms.Intents.html">android.provider.Telephony.ACTION_CHANGE_DEFAULT</a> intent to show a dialog to change the default SMS application, if the 1460device implementation reports android.hardware.telephony. 1461 </li> 1462 <li> 1463 MUST honor the 1464 <a href="http://developer.android.com/reference/android/provider/Settings.html#ACTION_NFC_PAYMENT_SETTINGS">android.settings.NFC_PAYMENT_SETTINGS</a> intent to show a default app settings menu for Tap and Pay, if the device 1465implementation reports android.hardware.nfc.hce. 1466 </li> 1467 <li> 1468 MUST honor the 1469 <a href="https://developer.android.com/reference/android/telecom/TelecomManager.html#ACTION_CHANGE_DEFAULT_DIALER"> 1470 <code>android.telecom.action.CHANGE_DEFAULT_DIALER</code></a> 1471 intent to show a dialog to allow the user to change the default Phone application, if the 1472device implementation reports 1473 <code> 1474 android.hardware.telephony 1475 </code>. 1476 </li> 1477 </ul> 1478 <h2 id="3_3_native_api_compatibility"> 1479 3.3. Native API Compatibility 1480 </h2> 1481 <p> 1482 Native code compatibility is challenging. For this reason, device implementers 1483are 1484 <strong> 1485 STRONGLY RECOMMENDED 1486 </strong> 1487 to use the implementations of the libraries listed 1488below from the upstream Android Open Source Project. 1489 </p> 1490 <h3 id="3_3_1_application_binary_interfaces"> 1491 3.3.1. Application Binary Interfaces 1492 </h3> 1493 <p> 1494 Managed Dalvik bytecode can call into native code provided in the application 1495.apk file as an ELF .so file compiled for the appropriate device hardware 1496architecture. As native code is highly dependent on the underlying processor 1497technology, Android defines a number of Application Binary Interfaces (ABIs) in 1498the Android NDK. Device implementations MUST be compatible with one or more 1499defined ABIs, and MUST implement compatibility with the Android NDK, as below. 1500 </p> 1501 <p> 1502 If a device implementation includes support for an Android ABI, it: 1503 </p> 1504 <ul> 1505 <li> 1506 MUST include support for code running in the managed environment to call 1507 into native code, using the standard Java Native Interface (JNI) semantics. 1508 </li> 1509 <li> 1510 MUST be source-compatible (i.e. header compatible) and binary-compatible 1511 (for the ABI) with each required library in the list below. 1512 </li> 1513 <li> 1514 MUST support the equivalent 32-bit ABI if any 64-bit ABI is supported. 1515 </li> 1516 <li> 1517 MUST accurately report the native Application Binary Interface (ABI) 1518 supported by the device, via the android.os.Build.SUPPORTED_ABIS, 1519 android.os.Build.SUPPORTED_32_BIT_ABIS, and 1520 android.os.Build.SUPPORTED_64_BIT_ABIS parameters, each a comma separated 1521 list of ABIs ordered from the most to the least preferred one. 1522 </li> 1523 <li> 1524 MUST report, via the above parameters, only those ABIs documented and 1525 described in the latest version of the 1526 <a href="https://developer.android.com/ndk/guides/abis.html">Android NDK ABI Management documentation</a>, and MUST 1527 include support for the 1528 <a href="http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.ddi0388f/Beijfcja.html">Advanced SIMD</a> ( a.k.a. NEON) extension. 1529 </li> 1530 <li> 1531 SHOULD be built using the source code and header files available in the 1532 upstream Android Open Source Project 1533 </li> 1534 </ul> 1535 <p> 1536 Note that future releases of the Android NDK may introduce support for 1537additional ABIs. If a device implementation is not compatible with an existing 1538predefined ABI, it MUST NOT report support for any ABIs at all. 1539 </p> 1540 <p> 1541 The following native code APIs MUST be available to apps that include native code: 1542 </p> 1543 <ul> 1544 <li> 1545 libandroid.so (native Android activity support) 1546 </li> 1547 <li> 1548 libc (C library) 1549 </li> 1550 <li> 1551 libcamera2ndk.so 1552 </li> 1553 <li> 1554 libdl (dynamic linker) 1555 </li> 1556 <li> 1557 libEGL.so (native OpenGL surface management) 1558 </li> 1559 <li> 1560 libGLESv1_CM.so (OpenGL ES 1.x) 1561 </li> 1562 <li> 1563 libGLESv2.so (OpenGL ES 2.0) 1564 </li> 1565 <li> 1566 libGLESv3.so (OpenGL ES 3.x) 1567 </li> 1568 <li> 1569 libicui18n.so 1570 </li> 1571 <li> 1572 libicuuc.so 1573 </li> 1574 <li> 1575 libjnigraphics.so 1576 </li> 1577 <li> 1578 liblog (Android logging) 1579 </li> 1580 <li> 1581 libmediandk.so (native media APIs support) 1582 </li> 1583 <li> 1584 libm (math library) 1585 </li> 1586 <li> 1587 libOpenMAXAL.so (OpenMAX AL 1.0.1 support) 1588 </li> 1589 <li> 1590 libOpenSLES.so (OpenSL ES 1.0.1 audio support) 1591 </li> 1592 <li> 1593 libRS.so 1594 </li> 1595 <li> 1596 libstdc++ (Minimal support for C++) 1597 </li> 1598 <li> 1599 libvukan.so (Vulkan) 1600 </li> 1601 <li> 1602 libz (Zlib compression) 1603 </li> 1604 <li> 1605 JNI interface 1606 </li> 1607 <li> 1608 Support for OpenGL, as described below 1609 </li> 1610 </ul> 1611 <p> 1612 For the native libraries listed above, the device implementation MUST NOT add 1613or remove the public functions. 1614 </p> 1615 <p> 1616 Native libraries not listed above but implemented and provided in AOSP as system 1617libraries are reserved and MUST NOT be exposed to third-party apps targeting API 1618level 24 or higher. 1619 </p> 1620 <p> 1621 Device implementations MAY add non-AOSP libraries and expose them directly as 1622an API to third-party apps but the additional libraries SHOULD be in 1623 <code> 1624 /vendor/lib 1625 </code> 1626 or 1627 <code> 1628 /vendor/lib64 1629 </code> 1630 and MUST be listed in 1631 <code> 1632 /vendor/etc/public.libraries.txt 1633 </code>. 1634 </p> 1635 <p> 1636 Note that device implementations MUST include libGLESv3.so and in turn, MUST export 1637all the OpenGL ES 3.1 and 1638 <a href="http://developer.android.com/guide/topics/graphics/opengl.html#aep">Android Extension Pack</a> function symbols as defined in the NDK release android-24. Although all the 1639symbols must be present, only the corresponding functions for OpenGL ES versions 1640and extensions actually supported by the device must be fully implemented. 1641 </p> 1642 <h4 id="3_3_1_1_graphic_libraries"> 1643 3.3.1.1. Graphic Libraries 1644 </h4> 1645 <p> 1646 <a href="https://www.khronos.org/registry/vulkan/specs/1.0-wsi_extensions/xhtml/vkspec.html">Vulkan</a> is a low-overhead, cross-platform API for high-performance 3D graphics. Device 1647implementations, even if not including support of the Vulkan APIs, MUST satisfy 1648the following requirements: 1649 </p> 1650 <ul> 1651 <li> 1652 It MUST always provide a native library named 1653 <code> 1654 libvulkan.so 1655 </code> 1656 which exports 1657 function symbols for the core Vulkan 1.0 API as well as the 1658 <code> 1659 VK_KHR_surface 1660 </code>, 1661 <code> 1662 VK_KHR_android_surface 1663 </code>, and 1664 <code> 1665 VK_KHR_swapchain 1666 </code> 1667 extensions. 1668 </li> 1669 </ul> 1670 <p> 1671 Device implementations, if including support of the Vulkan APIs: 1672 </p> 1673 <ul> 1674 <li> 1675 MUST report, one or more 1676 <code> 1677 VkPhysicalDevices 1678 </code> 1679 through the 1680 <code> 1681 vkEnumeratePhysicalDevices 1682 </code> 1683 call. 1684 </li> 1685 <li> 1686 Each enumerated 1687 <code> 1688 VkPhysicalDevices 1689 </code> 1690 MUST fully implement the Vulkan 1.0 API. 1691 </li> 1692 <li> 1693 MUST report the correct 1694 <a href="https://developer.android.com/reference/android/content/pm/PackageManager.html#FEATURE_VULKAN_HARDWARE_LEVEL"> 1695 <code>PackageManager#FEATURE_VULKAN_HARDWARE_LEVEL</code></a> and 1696 <a href="https://developer.android.com/reference/android/content/pm/PackageManager.html#FEATURE_VULKAN_HARDWARE_VERSION"> 1697 <code>PackageManager#FEATURE_VULKAN_HARDWARE_VERSION</code></a> feature flags. 1698 </li> 1699 <li> 1700 MUST enumerate layers, contained in native libraries named 1701 <code> 1702 libVkLayer*.so 1703 </code> 1704 in the application package’s native library directory, through the 1705 <code> 1706 vkEnumerateInstanceLayerProperties 1707 </code> 1708 and 1709 <code> 1710 vkEnumerateDeviceLayerProperties 1711 </code> 1712 functions in 1713 <code> 1714 libvulkan.so 1715 </code> 1716 </li> 1717 <li> 1718 MUST NOT enumerate layers provided by libraries outside of the application 1719 package, or provide other ways of tracing or intercepting the Vulkan API, 1720 unless the application has the 1721 <code> 1722 android:debuggable=”true” 1723 </code> 1724 attribute. 1725 </li> 1726 </ul> 1727 <p> 1728 Device implementations, if not including support of the Vulkan APIs: 1729 </p> 1730 <ul> 1731 <li> 1732 MUST report 0 1733 <code> 1734 VkPhysicalDevices 1735 </code> 1736 through the 1737 <code> 1738 vkEnumeratePhysicalDevices 1739 </code> 1740 call. 1741 </li> 1742 <li> 1743 MUST NOT delare any of the Vulkan feature flags 1744 <a href="https://developer.android.com/reference/android/content/pm/PackageManager.html#FEATURE_VULKAN_HARDWARE_LEVEL"> 1745 <code> PackageManager#FEATURE_VULKAN_HARDWARE_LEVEL</code></a> and 1746 <a href="https://developer.android.com/reference/android/content/pm/PackageManager.html#FEATURE_VULKAN_HARDWARE_VERSION"> 1747 <code> PackageManager#FEATURE_VULKAN_HARDWARE_VERSION</code></a>. 1748 </li> 1749 </ul> 1750 <h3 id="3_3_2_32-bit_arm_native_code_compatibility"> 1751 3.3.2. 32-bit ARM Native Code Compatibility 1752 </h3> 1753 <p> 1754 The ARMv8 architecture deprecates several CPU operations, including some 1755operations used in existing native code. On 64-bit ARM devices, the following 1756deprecated operations MUST remain available to 32-bit native ARM code, either 1757through native CPU support or through software emulation: 1758 </p> 1759 <ul> 1760 <li> 1761 SWP and SWPB instructions 1762 </li> 1763 <li> 1764 SETEND instruction 1765 </li> 1766 <li> 1767 CP15ISB, CP15DSB, and CP15DMB barrier operations 1768 </li> 1769 </ul> 1770 <p> 1771 Legacy versions of the Android NDK used /proc/cpuinfo to discover CPU features 1772from 32-bit ARM native code. For compatibility with applications built using 1773this NDK, devices MUST include the following lines in /proc/cpuinfo when it is 1774read by 32-bit ARM applications: 1775 </p> 1776 <ul> 1777 <li> 1778 "Features: ", followed by a list of any optional ARMv7 CPU features supported by the device. 1779 </li> 1780 <li> 1781 "CPU architecture: ", followed by an integer describing the device's highest 1782 supported ARM architecture (e.g., "8" for ARMv8 devices). 1783 </li> 1784 </ul> 1785 <p> 1786 These requirements only apply when /proc/cpuinfo is read by 32-bit ARM 1787applications. Devices SHOULD not alter /proc/cpuinfo when read by 64-bit ARM or 1788non-ARM applications. 1789 </p> 1790 <h2 id="3_4_web_compatibility"> 1791 3.4. Web Compatibility 1792 </h2> 1793 <h3 id="3_4_1_webview_compatibility"> 1794 3.4.1. WebView Compatibility 1795 </h3> 1796 <div class="note"> 1797 Android Watch devices MAY, but all other device implementations MUST provide a 1798complete implementation of the android.webkit.Webview API. 1799 </div> 1800 <p> 1801 The platform feature android.software.webview MUST be reported on any device 1802that provides a complete implementation of the android.webkit.WebView API, and 1803MUST NOT be reported on devices without a complete implementation of the API. 1804The Android Open Source implementation uses code from the Chromium Project to 1805implement the 1806 <a href="http://developer.android.com/reference/android/webkit/WebView.html">android.webkit.WebView</a>. 1807Because it is not feasible to develop a comprehensive test suite for a web 1808rendering system, device implementers MUST use the specific upstream build of 1809Chromium in the WebView implementation. Specifically: 1810 </p> 1811 <ul> 1812 <li> 1813 Device android.webkit.WebView implementations MUST be based on the 1814 <a href="http://www.chromium.org/">Chromium</a> build from the upstream Android Open 1815 Source Project for Android 7.0. This build includes a specific 1816 set of functionality and security fixes for the WebView. 1817 </li> 1818 <li> 1819 <p> 1820 The user agent string reported by the WebView MUST be in this format: 1821 </p> 1822 <p> 1823 Mozilla/5.0 (Linux; Android $(VERSION); $(MODEL) Build/$(BUILD); wv) 1824AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 $(CHROMIUM_VER) Mobile 1825Safari/537.36 1826 </p> 1827 <ul> 1828 <li> 1829 The value of the $(VERSION) string MUST be the same as the value for android.os.Build.VERSION.RELEASE. 1830 </li> 1831 <li> 1832 The value of the $(MODEL) string MUST be the same as the value for android.os.Build.MODEL. 1833 </li> 1834 <li> 1835 The value of the $(BUILD) string MUST be the same as the value for android.os.Build.ID. 1836 </li> 1837 <li> 1838 The value of the $(CHROMIUM_VER) string MUST be the version of Chromium in the upstream Android Open Source Project. 1839 </li> 1840 <li> 1841 Device implementations MAY omit Mobile in the user agent string. 1842 </li> 1843 </ul> 1844 </li> 1845 </ul> 1846 <p> 1847 The WebView component SHOULD include support for as many HTML5 features as 1848possible and if it supports the feature SHOULD conform to the 1849 <a href="http://html.spec.whatwg.org/multipage/">HTML5 specification</a>. 1850 </p> 1851 <h3 id="3_4_2_browser_compatibility"> 1852 3.4.2. Browser Compatibility 1853 </h3> 1854 <div class="note"> 1855 Android Television, Watch, and Android Automotive implementations MAY omit a 1856browser application, but MUST support the public intent patterns as described in 1857 <a href="#3_2_3_1_core_application_intents">section 3.2.3.1</a>. All other types of device 1858implementations MUST include a standalone Browser application for general user 1859web browsing. 1860 </div> 1861 <p> 1862 The standalone Browser MAY be based on a browser technology other than WebKit. 1863However, even if an alternate Browser application is used, the 1864android.webkit.WebView component provided to third-party applications MUST be 1865based on WebKit, as described in 1866 <a href="#3_4_1_webview_compatibility">section 3.4.1</a>. 1867 </p> 1868 <p> 1869 Implementations MAY ship a custom user agent string in the standalone Browser application. 1870 </p> 1871 <p> 1872 The standalone Browser application (whether based on the upstream WebKit Browser 1873application or a third-party replacement) SHOULD include support for as much of 1874 <a href="http://html.spec.whatwg.org/multipage/">HTML5</a> as possible. Minimally, device 1875implementations MUST support each of these APIs associated with HTML5: 1876 </p> 1877 <ul> 1878 <li> 1879 <a href="http://www.w3.org/html/wg/drafts/html/master/browsers.html#offline">application cache/offline operation</a> </li> 1880 <li> 1881 <a href="http://www.w3.org/html/wg/drafts/html/master/semantics.html#video"><video> tag</a> </li> 1882 <li> 1883 <a href="http://www.w3.org/TR/geolocation-API/">geolocation</a> </li> 1884 </ul> 1885 <p> 1886 Additionally, device implementations MUST support the HTML5/W3C 1887 <a href="http://www.w3.org/TR/webstorage/">webstorage API</a> and SHOULD support the HTML5/W3C 1888 <a href="http://www.w3.org/TR/IndexedDB/">IndexedDB API</a>. Note that as the web 1889development standards bodies are transitioning to favor IndexedDB over 1890webstorage, IndexedDB is expected to become a required component in a future 1891version of Android. 1892 </p> 1893 <h2 id="3_5_api_behavioral_compatibility"> 1894 3.5. API Behavioral Compatibility 1895 </h2> 1896 <p> 1897 The behaviors of each of the API types (managed, soft, native, and web) must be 1898consistent with the preferred implementation of the upstream 1899 <a href="http://source.android.com/">Android Open Source Project</a>. Some specific areas of 1900compatibility are: 1901 </p> 1902 <ul> 1903 <li> 1904 Devices MUST NOT change the behavior or semantics of a standard intent. 1905 </li> 1906 <li> 1907 Devices MUST NOT alter the lifecycle or lifecycle semantics of a particular 1908 type of system component (such as Service, Activity, ContentProvider, etc.). 1909 </li> 1910 <li> 1911 Devices MUST NOT change the semantics of a standard permission. 1912 </li> 1913 </ul> 1914 <p> 1915 The above list is not comprehensive. The Compatibility Test Suite (CTS) tests 1916significant portions of the platform for behavioral compatibility, but not all. 1917It is the responsibility of the implementer to ensure behavioral compatibility 1918with the Android Open Source Project. For this reason, device implementers 1919SHOULD use the source code available via the Android Open Source Project where 1920possible, rather than re-implement significant parts of the system. 1921 </p> 1922 <h2 id="3_6_api_namespaces"> 1923 3.6. API Namespaces 1924 </h2> 1925 <p> 1926 Android follows the package and class namespace conventions defined by the Java 1927programming language. To ensure compatibility with third-party applications, 1928device implementers MUST NOT make any prohibited modifications (see below) to 1929these package namespaces: 1930 </p> 1931 <ul> 1932 <li> 1933 java.* 1934 </li> 1935 <li> 1936 javax.* 1937 </li> 1938 <li> 1939 sun.* 1940 </li> 1941 <li> 1942 android.* 1943 </li> 1944 <li> 1945 com.android.* 1946 </li> 1947 </ul> 1948 <p> 1949 <strong> 1950 Prohibited modifications include 1951 </strong> 1952 : 1953 </p> 1954 <ul> 1955 <li> 1956 Device implementations MUST NOT modify the publicly exposed APIs on the 1957 Android platform by changing any method or class signatures, or by removing 1958 classes or class fields. 1959 </li> 1960 <li> 1961 Device implementers MAY modify the underlying implementation of the APIs, 1962 but such modifications MUST NOT impact the stated behavior and Java-language 1963 signature of any publicly exposed APIs. 1964 </li> 1965 <li> 1966 Device implementers MUST NOT add any publicly exposed elements (such as 1967 classes or interfaces, or fields or methods to existing classes or 1968 interfaces) to the APIs above. 1969 </li> 1970 </ul> 1971 <p> 1972 A “publicly exposed element” is any construct that is not decorated with 1973the“@hide” marker as used in the upstream Android source code. In other words, 1974device implementers MUST NOT expose new APIs or alter existing APIs in the 1975namespaces noted above. Device implementers MAY make internal-only 1976modifications, but those modifications MUST NOT be advertised or otherwise 1977exposed to developers. 1978 </p> 1979 <p> 1980 Device implementers MAY add custom APIs, but any such APIs MUST NOT be in a 1981namespace owned by or referring to another organization. For instance, device 1982implementers MUST NOT add APIs to the com.google.* or similar namespace: only 1983Google may do so. Similarly, Google MUST NOT add APIs to other companies' 1984namespaces. Additionally, if a device implementation includes custom APIs 1985outside the standard Android namespace, those APIs MUST be packaged in an 1986Android shared library so that only apps that explicitly use them (via the 1987<uses-library> mechanism) are affected by the increased memory usage of such 1988APIs. 1989 </p> 1990 <p> 1991 If a device implementer proposes to improve one of the package namespaces above 1992(such as by adding useful new functionality to an existing API, or adding a new 1993API), the implementer SHOULD visit 1994 <a href="http://source.android.com/">source.android.com</a> and begin the process for 1995contributing changes and code, according to the information on that site. 1996 </p> 1997 <p> 1998 Note that the restrictions above correspond to standard conventions for naming 1999APIs in the Java programming language; this section simply aims to reinforce 2000those conventions and make them binding through inclusion in this Compatibility 2001Definition. 2002 </p> 2003 <h2 id="3_7_runtime_compatibility"> 2004 3.7. Runtime Compatibility 2005 </h2> 2006 <p> 2007 Device implementations MUST support the full Dalvik Executable (DEX) format and 2008 <a href="https://android.googlesource.com/platform/dalvik/">Dalvik bytecode specification and semantics</a>. 2009Device implementers SHOULD use ART, the reference upstream implementation of the Dalvik 2010Executable Format, and the reference implementation’s package management system. 2011 </p> 2012 <p> 2013 Device implementations MUST configure Dalvik runtimes to allocate memory in 2014accordance with the upstream Android platform, and as specified by the following 2015table. (See 2016 <a href="#7_1_1_screen_configuration">section 7.1.1</a> for screen size and 2017screen density definitions.) Note that memory values specified below are 2018considered minimum values and device implementations MAY allocate more memory 2019per application. 2020 </p> 2021 <table> 2022 <tr> 2023 <th> 2024 Screen Layout 2025 </th> 2026 <th> 2027 Screen Density 2028 </th> 2029 <th> 2030 Minimum Application Memory 2031 </th> 2032 </tr> 2033 <tr> 2034 <td rowspan="12"> 2035 Android Watch 2036 </td> 2037 <td> 2038 120 dpi (ldpi) 2039 </td> 2040 <td rowspan="3"> 2041 32MB 2042 </td> 2043 </tr> 2044 <tr> 2045 <td> 2046 160 dpi (mdpi) 2047 </td> 2048 </tr> 2049 <tr> 2050 <td> 2051 213 dpi (tvdpi) 2052 </td> 2053 </tr> 2054 <tr> 2055 <td> 2056 240 dpi (hdpi) 2057 </td> 2058 <td rowspan="2"> 2059 36MB 2060 </td> 2061 </tr> 2062 <tr> 2063 <td> 2064 280 dpi (280dpi) 2065 </td> 2066 </tr> 2067 <tr> 2068 <td> 2069 320 dpi (xhdpi) 2070 </td> 2071 <td rowspan="2"> 2072 48MB 2073 </td> 2074 </tr> 2075 <tr> 2076 <td> 2077 360 dpi (360dpi) 2078 </td> 2079 </tr> 2080 <tr> 2081 <td> 2082 400 dpi (400dpi) 2083 </td> 2084 <td> 2085 56MB 2086 </td> 2087 </tr> 2088 <tr> 2089 <td> 2090 420 dpi (420dpi) 2091 </td> 2092 <td> 2093 64MB 2094 </td> 2095 </tr> 2096 <tr> 2097 <td> 2098 480 dpi (xxhdpi) 2099 </td> 2100 <td> 2101 88MB 2102 </td> 2103 </tr> 2104 <tr> 2105 <td> 2106 560 dpi (560dpi) 2107 </td> 2108 <td> 2109 112MB 2110 </td> 2111 </tr> 2112 <tr> 2113 <td> 2114 640 dpi (xxxhdpi) 2115 </td> 2116 <td> 2117 154MB 2118 </td> 2119 </tr> 2120 <tr> 2121 <td rowspan="12"> 2122 small/normal 2123 </td> 2124 <td> 2125 120 dpi (ldpi) 2126 </td> 2127 <td rowspan="2"> 2128 32MB 2129 </td> 2130 </tr> 2131 <tr> 2132 <td> 2133 160 dpi (mdpi) 2134 </td> 2135 </tr> 2136 <tr> 2137 <td> 2138 213 dpi (tvdpi) 2139 </td> 2140 <td rowspan="3"> 2141 48MB 2142 </td> 2143 </tr> 2144 <tr> 2145 <td> 2146 240 dpi (hdpi) 2147 </td> 2148 </tr> 2149 <tr> 2150 <td> 2151 280 dpi (280dpi) 2152 </td> 2153 </tr> 2154 <tr> 2155 <td> 2156 320 dpi (xhdpi) 2157 </td> 2158 <td rowspan="2"> 2159 80MB 2160 </td> 2161 </tr> 2162 <tr> 2163 <td> 2164 360 dpi (360dpi) 2165 </td> 2166 </tr> 2167 <tr> 2168 <td> 2169 400 dpi (400dpi) 2170 </td> 2171 <td> 2172 96MB 2173 </td> 2174 </tr> 2175 <tr> 2176 <td> 2177 420 dpi (420dpi) 2178 </td> 2179 <td> 2180 112MB 2181 </td> 2182 </tr> 2183 <tr> 2184 <td> 2185 480 dpi (xxhdpi) 2186 </td> 2187 <td> 2188 128MB 2189 </td> 2190 </tr> 2191 <tr> 2192 <td> 2193 560 dpi (560dpi) 2194 </td> 2195 <td> 2196 192MB 2197 </td> 2198 </tr> 2199 <tr> 2200 <td> 2201 640 dpi (xxxhdpi) 2202 </td> 2203 <td> 2204 256MB 2205 </td> 2206 </tr> 2207 <tr> 2208 <td rowspan="12"> 2209 large 2210 </td> 2211 <td> 2212 120 dpi (ldpi) 2213 </td> 2214 <td> 2215 32MB 2216 </td> 2217 </tr> 2218 <tr> 2219 <td> 2220 160 dpi (mdpi) 2221 </td> 2222 <td> 2223 48MB 2224 </td> 2225 </tr> 2226 <tr> 2227 <td> 2228 213 dpi (tvdpi) 2229 </td> 2230 <td rowspan="2"> 2231 80MB 2232 </td> 2233 </tr> 2234 <tr> 2235 <td> 2236 240 dpi (hdpi) 2237 </td> 2238 </tr> 2239 <tr> 2240 <td> 2241 280 dpi (280dpi) 2242 </td> 2243 <td> 2244 96MB 2245 </td> 2246 </tr> 2247 <tr> 2248 <td> 2249 320 dpi (xhdpi) 2250 </td> 2251 <td> 2252 128MB 2253 </td> 2254 </tr> 2255 <tr> 2256 <td> 2257 360 dpi (360dpi) 2258 </td> 2259 <td> 2260 160MB 2261 </td> 2262 </tr> 2263 <tr> 2264 <td> 2265 400 dpi (400dpi) 2266 </td> 2267 <td> 2268 192MB 2269 </td> 2270 </tr> 2271 <tr> 2272 <td> 2273 420 dpi (420dpi) 2274 </td> 2275 <td> 2276 228MB 2277 </td> 2278 </tr> 2279 <tr> 2280 <td> 2281 480 dpi (xxhdpi) 2282 </td> 2283 <td> 2284 256MB 2285 </td> 2286 </tr> 2287 <tr> 2288 <td> 2289 560 dpi (560dpi) 2290 </td> 2291 <td> 2292 384MB 2293 </td> 2294 </tr> 2295 <tr> 2296 <td> 2297 640 dpi (xxxhdpi) 2298 </td> 2299 <td> 2300 512MB 2301 </td> 2302 </tr> 2303 <tr> 2304 <td rowspan="12"> 2305 xlarge 2306 </td> 2307 <td> 2308 120 dpi (ldpi) 2309 </td> 2310 <td> 2311 48MB 2312 </td> 2313 </tr> 2314 <tr> 2315 <td> 2316 160 dpi (mdpi) 2317 </td> 2318 <td> 2319 80MB 2320 </td> 2321 </tr> 2322 <tr> 2323 <td> 2324 213 dpi (tvdpi) 2325 </td> 2326 <td rowspan="2"> 2327 96MB 2328 </td> 2329 </tr> 2330 <tr> 2331 <td> 2332 240 dpi (hdpi) 2333 </td> 2334 </tr> 2335 <tr> 2336 <td> 2337 280 dpi (280dpi) 2338 </td> 2339 <td> 2340 144MB 2341 </td> 2342 </tr> 2343 <tr> 2344 <td> 2345 320 dpi (xhdpi) 2346 </td> 2347 <td> 2348 192MB 2349 </td> 2350 </tr> 2351 <tr> 2352 <td> 2353 360 dpi (360dpi) 2354 </td> 2355 <td> 2356 240MB 2357 </td> 2358 </tr> 2359 <tr> 2360 <td> 2361 400 dpi (400dpi) 2362 </td> 2363 <td> 2364 288MB 2365 </td> 2366 </tr> 2367 <tr> 2368 <td> 2369 420 dpi (420dpi) 2370 </td> 2371 <td> 2372 336MB 2373 </td> 2374 </tr> 2375 <tr> 2376 <td> 2377 480 dpi (xxhdpi) 2378 </td> 2379 <td> 2380 384MB 2381 </td> 2382 </tr> 2383 <tr> 2384 <td> 2385 560 dpi (560dpi) 2386 </td> 2387 <td> 2388 576MB 2389 </td> 2390 </tr> 2391 <tr> 2392 <td> 2393 640 dpi (xxxhdpi) 2394 </td> 2395 <td> 2396 768MB 2397 </td> 2398 </tr> 2399 </table> 2400 <h2 id="3_8_user_interface_compatibility"> 2401 3.8. User Interface Compatibility 2402 </h2> 2403 <h3 id="3_8_1_launcher_(home_screen)"> 2404 3.8.1. Launcher (Home Screen) 2405 </h3> 2406 <p> 2407 Android includes a launcher application (home screen) and support for 2408third-party applications to replace the device launcher (home screen). Device 2409implementations that allow third-party applications to replace the device home 2410screen MUST declare the platform feature android.software.home_screen. 2411 </p> 2412 <h3 id="3_8_2_widgets"> 2413 3.8.2. Widgets 2414 </h3> 2415 <div class="note"> 2416 Widgets are optional for all Android device implementations, but SHOULD be 2417supported on Android Handheld devices. 2418 </div> 2419 <p> 2420 Android defines a component type and corresponding API and lifecycle that allows 2421applications to expose an 2422 <a href="http://developer.android.com/guide/practices/ui_guidelines/widget_design.html">“AppWidget”</a> to the end user, a feature that is STRONGLY RECOMMENDED to be supported on 2423Handheld Device implementations. Device implementations that support embedding 2424widgets on the home screen MUST meet the following requirements and declare 2425support for platform feature android.software.app_widgets. 2426 </p> 2427 <ul> 2428 <li> 2429 Device launchers MUST include built-in support for AppWidgets and expose 2430 user interface affordances to add, configure, view, and remove AppWidgets 2431 directly within the Launcher. 2432 </li> 2433 <li> 2434 Device implementations MUST be capable of rendering widgets that are 4 x 4 2435 in the standard grid size. See the 2436 <a href="http://developer.android.com/guide/practices/ui_guidelines/widget_design.html">App Widget Design Guidelines</a> 2437 in the Android SDK documentation for details. 2438 </li> 2439 <li> 2440 Device implementations that include support for lock screen MAY support 2441 application widgets on the lock screen. 2442 </li> 2443 <li> 2444 SHOULD trigger the fast-switch action between the two most recently used apps, 2445 when the recents function key is tapped twice. 2446 </li> 2447 <li> 2448 SHOULD trigger the split-screen multiwindow-mode, if supported, when the recents 2449 functions key is long pressed. 2450 </li> 2451 </ul> 2452 <h3 id="3_8_3_notifications"> 2453 3.8.3. Notifications 2454 </h3> 2455 <p> 2456 Android includes APIs that allow developers to 2457 <a href="http://developer.android.com/guide/topics/ui/notifiers/notifications.html">notify users of notable events</a> using hardware and software features of the device. 2458 </p> 2459 <p> 2460 Some APIs allow applications to perform notifications or attract attention using 2461hardware—specifically sound, vibration, and light. Device implementations MUST 2462support notifications that use hardware features, as described in the SDK 2463documentation, and to the extent possible with the device implementation 2464hardware. For instance, if a device implementation includes a vibrator, it MUST 2465correctly implement the vibration APIs. If a device implementation lacks 2466hardware, the corresponding APIs MUST be implemented as no-ops. This behavior is 2467further detailed in 2468 <a href="#7_hardware_compatibility">section 7</a>. 2469 </p> 2470 <p> 2471 Additionally, the implementation MUST correctly render all 2472 <a href="https://developer.android.com/guide/topics/resources/available-resources.html">resources</a> (icons, animation files etc.) provided for in the APIs, or in the Status/System 2473Bar 2474 <a href="http://developer.android.com/design/style/iconography.html">icon style guide</a>, which in the 2475case of an Android Television device includes the possibility to not display the 2476notifications. Device implementers MAY provide an alternative user experience 2477for notifications than that provided by the reference Android Open Source 2478implementation; however, such alternative notification systems MUST support 2479existing notification resources, as above. 2480 </p> 2481 <div class="note"> 2482 Android Automotive implementations MAY manage the visibility and timing of 2483notifications to mitigate driver distraction, but MUST display 2484notifications that use 2485 <a href="https://developer.android.com/reference/android/app/Notification.CarExtender.html">CarExtender</a> when requested by applications. 2486 </div> 2487 <p> 2488 Android includes support for various notifications, such as: 2489 </p> 2490 <ul> 2491 <li> 2492 <strong> 2493 Rich notifications 2494 </strong> 2495 . Interactive Views for ongoing notifications. 2496 </li> 2497 <li> 2498 <strong> 2499 Heads-up notifications 2500 </strong> 2501 . Interactive Views users can act on or dismiss without leaving the current app. 2502 </li> 2503 <li> 2504 <strong> 2505 Lock screen notifications 2506 </strong> 2507 . Notifications shown over a lock screen with granular control on visibility. 2508 </li> 2509 </ul> 2510 <p> 2511 Android device implementations, when such notifications are made visible, MUST 2512properly execute Rich and Heads-up notifications and include the title/name, 2513icon, text as 2514 <a href="https://developer.android.com/design/patterns/notifications.html">documented in the Android APIs</a>. 2515 </p> 2516 <p> 2517 Android includes Notification Listener Service APIs that allow apps (once 2518explicitly enabled by the user) to receive a copy of all notifications as they 2519are posted or updated. Device implementations MUST correctly and promptly send 2520notifications in their entirety to all such installed and user-enabled listener 2521services, including any and all metadata attached to the Notification object. 2522 </p> 2523 <p> 2524 Device implementations that support the DND (Do not Disturb) feature MUST meet 2525the following requirements: 2526 </p> 2527 <ul> 2528 <li> 2529 MUST implement an activity where the user can grant or deny the app access 2530 to DND policy configurations in response to the intent 2531 <a href="https://developer.android.com/reference/android/provider/Settings.html#ACTION_NOTIFICATION_POLICY_ACCESS_SETTINGS">ACTION_NOTIFICATION_POLICY_ACCESS_SETTINGS</a>. 2532 </li> 2533 <li> 2534 MUST display 2535 <a href="https://developer.android.com/reference/android/app/NotificationManager.html#addAutomaticZenRule(android.app.AutomaticZenRule)">Automatic DND rules</a> created by applications alongside the user-created and pre-defined rules. 2536 </li> 2537 <li> 2538 MUST honor the 2539 <a href="https://developer.android.com/reference/android/app/NotificationManager.Policy.html#suppressedVisualEffects"> 2540 <code>suppressedVisualEffects</code></a> values passed along the 2541 <a href="https://developer.android.com/reference/android/app/NotificationManager.Policy.html#NotificationManager.Policy(int, int, int, int)"> 2542 <code> NotificationManager.Policy</code></a>. 2543 </li> 2544 </ul> 2545 <h3 id="3_8_4_search"> 2546 3.8.4. Search 2547 </h3> 2548 <p> 2549 Android includes APIs that allow developers to 2550 <a href="http://developer.android.com/reference/android/app/SearchManager.html">incorporate search</a> into their applications and expose their application’s data into the global 2551system search. Generally speaking, this functionality consists of a single, 2552system-wide user interface that allows users to enter queries, displays 2553suggestions as users type, and displays results. The Android APIs allow 2554developers to reuse this interface to provide search within their own apps and 2555allow developers to supply results to the common global search user interface. 2556 </p> 2557 <p> 2558 Android device implementations SHOULD include global search, a single, shared, 2559system-wide search user interface capable of real-time suggestions in response 2560to user input. Device implementations SHOULD implement the APIs that allow 2561developers to reuse this user interface to provide search within their own 2562applications. Device implementations that implement the global search interface 2563MUST implement the APIs that allow third-party applications to add suggestions 2564to the search box when it is run in global search mode. If no third-party 2565applications are installed that make use of this functionality, the default 2566behavior SHOULD be to display web search engine results and suggestions. 2567 </p> 2568 <p> 2569 Android device implementations SHOULD, and Android Automotive implementations 2570MUST, implement an assistant on the device to 2571handle the 2572 <a href="http://developer.android.com/reference/android/content/Intent.html#ACTION_ASSIST">Assist action</a>. 2573 </p> 2574 <p> 2575 Android also includes the 2576 <a href="https://developer.android.com/reference/android/app/assist/package-summary.html">Assist APIs</a> to allow applications to elect how much information of the current context is 2577shared with the assistant on the device. Device implementations supporting the 2578Assist action MUST indicate clearly to the end user when the context is 2579shared by displaying a white light around the edges of the screen. To ensure 2580clear visibility to the end user, the indication MUST meet or exceed the 2581duration and brightness of the Android Open Source Project implementation. 2582 </p> 2583 <h3 id="3_8_5_toasts"> 2584 3.8.5. Toasts 2585 </h3> 2586 <p> 2587 Applications can use the 2588 <a href="http://developer.android.com/reference/android/widget/Toast.html">“Toast” API</a> to 2589display short non-modal strings to the end user that disappear after a brief 2590period of time. Device implementations MUST display Toasts from applications to 2591end users in some high-visibility manner. 2592 </p> 2593 <h3 id="3_8_6_themes"> 2594 3.8.6. Themes 2595 </h3> 2596 <p> 2597 Android provides “themes” as a mechanism for applications to apply styles across 2598an entire Activity or application. 2599 </p> 2600 <p> 2601 Android includes a “Holo” theme family as a set of defined styles for 2602application developers to use if they want to match the 2603 <a href="http://developer.android.com/guide/topics/ui/themes.html">Holo theme look and feel</a> as defined by the Android SDK. Device implementations MUST NOT alter any of the 2604 <a href="http://developer.android.com/reference/android/R.style.html">Holo theme attributes</a> exposed to applications. 2605 </p> 2606 <p> 2607 Android includes a “Material” theme family as a set of defined styles for 2608application developers to use if they want to match the design theme’s look and 2609feel across the wide variety of different Android device types. Device 2610implementations MUST support the “Material” theme family and MUST NOT alter any 2611of the 2612 <a href="http://developer.android.com/reference/android/R.style.html#Theme_Material">Material theme attributes</a> or their assets exposed to applications. 2613 </p> 2614 <p> 2615 Android also includes a “Device Default” theme family as a set of defined styles 2616for application developers to use if they want to match the look and feel of the 2617device theme as defined by the device implementer. Device implementations MAY 2618modify the 2619 <a href="http://developer.android.com/reference/android/R.style.html">Device Default theme attributes</a> exposed 2620to applications. 2621 </p> 2622 <p> 2623 Android supports a variant theme with translucent system bars, which allows 2624application developers to fill the area behind the status and navigation bar 2625with their app content. To enable a consistent developer experience in this 2626configuration, it is important the status bar icon style is maintained across 2627different device implementations. Therefore, Android device implementations MUST 2628use white for system status icons (such as signal strength and battery level) 2629and notifications issued by the system, unless the icon is indicating a 2630problematic status or an app requests a light status bar using the 2631SYSTEM_UI_FLAG_LIGHT_STATUS_BAR flag. When an app requests a light status bar, 2632Android device implementations MUST change the color of the system status icons 2633to black (for details, refer to 2634 <a href="http://developer.android.com/reference/android/R.style.html">R.style</a> ). 2635 </p> 2636 <h3 id="3_8_7_live_wallpapers"> 2637 3.8.7. Live Wallpapers 2638 </h3> 2639 <p> 2640 Android defines a component type and corresponding API and lifecycle that allows 2641applications to expose one or more 2642 <a href="http://developer.android.com/reference/android/service/wallpaper/WallpaperService.html">“Live Wallpapers”</a> to the end user. Live wallpapers are animations, patterns, or similar images 2643with limited input capabilities that display as a wallpaper, behind other 2644applications. 2645 </p> 2646 <p> 2647 Hardware is considered capable of reliably running live wallpapers if it can run 2648all live wallpapers, with no limitations on functionality, at a reasonable frame 2649rate with no adverse effects on other applications. If limitations in the 2650hardware cause wallpapers and/or applications to crash, malfunction, consume 2651excessive CPU or battery power, or run at unacceptably low frame rates, the 2652hardware is considered incapable of running live wallpaper. As an example, some 2653live wallpapers may use an OpenGL 2.0 or 3.x context to render their content. 2654Live wallpaper will not run reliably on hardware that does not support multiple 2655OpenGL contexts because the live wallpaper use of an OpenGL context may conflict 2656with other applications that also use an OpenGL context. 2657 </p> 2658 <p> 2659 Device implementations capable of running live wallpapers reliably as described 2660above SHOULD implement live wallpapers, and when implemented MUST report the 2661platform feature flag android.software.live_wallpaper. 2662 </p> 2663 <h3 id="3_8_8_activity_switching"> 2664 3.8.8. Activity Switching 2665 </h3> 2666 <div class="note"> 2667 As the Recent function navigation key is OPTIONAL, the requirement to implement 2668the overview screen is OPTIONAL for Android Watch and Android Automotive implementations, 2669and RECOMMENDED for Android Television devices. There SHOULD still be a 2670method to switch between activities on Android Automotive implementations. 2671 </div> 2672 <p> 2673 The upstream Android source code includes the 2674 <a href="http://developer.android.com/guide/components/recents.html">overview screen</a>, a 2675system-level user interface for task switching and displaying recently accessed 2676activities and tasks using a thumbnail image of the application’s graphical 2677state at the moment the user last left the application. Device implementations 2678including the recents function navigation key as detailed in 2679 <a href="#7_2_3_navigation_keys">section 7.2.3</a> MAY alter the interface but MUST meet the 2680following requirements: 2681 </p> 2682 <ul> 2683 <li> 2684 MUST support at least up to 20 displayed activities. 2685 </li> 2686 <li> 2687 MUST at least display the title of 4 activities at a time. 2688 </li> 2689 <li> 2690 MUST implement the 2691 <a href="http://developer.android.com/about/versions/android-5.0.html#ScreenPinning">screen pinning behavior</a> and provide the user with a settings menu to toggle the feature. 2692 </li> 2693 <li> 2694 SHOULD display highlight color, icon, screen title in recents. 2695 </li> 2696 <li> 2697 SHOULD display a closing affordance ("x") but MAY delay this until user interacts with screens. 2698 </li> 2699 <li> 2700 SHOULD implement a shortcut to switch easily to the previous activity 2701 </li> 2702 <li> 2703 MAY display affiliated recents as a group that moves together. 2704 </li> 2705 </ul> 2706 <p> 2707 Device implementations are STRONGLY RECOMMENDED to use the upstream Android user 2708interface (or a similar thumbnail-based interface) for the overview screen. 2709 </p> 2710 <h3 id="3_8_9_input_management"> 2711 3.8.9. Input Management 2712 </h3> 2713 <p> 2714 Android includes support for 2715 <a href="http://developer.android.com/guide/topics/text/creating-input-method.html">Input Management</a> and support for third-party input method editors. Device implementations that 2716allow users to use third-party input methods on the device MUST declare the 2717platform feature android.software.input_methods and support IME APIs as defined 2718in the Android SDK documentation. 2719 </p> 2720 <p> 2721 Device implementations that declare the android.software.input_methods feature 2722MUST provide a user-accessible mechanism to add and configure third-party input 2723methods. Device implementations MUST display the settings interface in response 2724to the android.settings.INPUT_METHOD_SETTINGS intent. 2725 </p> 2726 <h3 id="3_8_10_lock_screen_media_control"> 2727 3.8.10. Lock Screen Media Control 2728 </h3> 2729 <p> 2730 The Remote Control Client API is deprecated from Android 5.0 in favor of the 2731 <a href="http://developer.android.com/reference/android/app/Notification.MediaStyle.html">Media Notification Template</a> that allows media applications to integrate with playback controls that are 2732displayed on the lock screen. Device implementations that support a lock screen, 2733unless an Android Automotive or Watch implementation, MUST display the 2734Lock screen Notifications including the Media Notification Template. 2735 </p> 2736 <h3 id="3_8_11_screen_savers_(previously_dreams)"> 2737 3.8.11. Screen savers (previously Dreams) 2738 </h3> 2739 <p> 2740 Android includes support for 2741 <a href="http://developer.android.com/reference/android/service/dreams/DreamService.html">interactivescreensavers</a>, 2742previously referred to as Dreams. Screen savers allow users to interact with 2743applications when a device connected to a power source is idle or docked in a 2744desk dock. Android Watch devices MAY implement screen savers, but other types 2745of device implementations SHOULD include support for screen savers and provide 2746a settings option for users toconfigure screen savers in response to the 2747 <code> 2748 android.settings.DREAM_SETTINGS 2749 </code> 2750 intent. 2751 </p> 2752 <h3 id="3_8_12_location"> 2753 3.8.12. Location 2754 </h3> 2755 <p> 2756 When a device has a hardware sensor (e.g. GPS) that is capable of providing the 2757location coordinates, 2758 <a href="http://developer.android.com/reference/android/provider/Settings.Secure.html#LOCATION_MODE">location modes</a> MUST be displayed in the Location menu within Settings. 2759 </p> 2760 <h3 id="3_8_13_unicode_and_font"> 2761 3.8.13. Unicode and Font 2762 </h3> 2763 <p> 2764 Android includes support for the emoji characters defined in 2765 <a href="http://www.unicode.org/versions/Unicode9.0.0/">Unicode 9.0</a>. All device 2766implementations MUST be capable of rendering these emoji characters 2767in color glyph and when Android device implementations include an IME, 2768it SHOULD provide an input method to the user for these emoji characters. 2769 </p> 2770 <p> 2771 Android handheld devices SHOULD support the skin tone and diverse family emojis 2772as specified in the 2773 <a href="http://unicode.org/reports/tr51">Unicode Technical Report #51</a>. 2774 </p> 2775 <p> 2776 Android includes support for Roboto 2 font with different 2777weights—sans-serif-thin, sans-serif-light, sans-serif-medium, sans-serif-black, 2778sans-serif-condensed, sans-serif-condensed-light—which MUST all be included for 2779the languages available on the device and full Unicode 7.0 coverage of Latin, 2780Greek, and Cyrillic, including the Latin Extended A, B, C, and D ranges, and all 2781glyphs in the currency symbols block of Unicode 7.0. 2782 </p> 2783 <h3 id="3_8_14_multi-windows"> 2784 3.8.14. Multi-windows 2785 </h3> 2786 <p> 2787 A device implementation MAY choose not to implement any multi-window modes, but 2788if it has the capability to display multiple activities at the same time it 2789MUST implement such multi-window mode(s) in accordance with the application 2790behaviors and APIs described in the Android SDK 2791 <a href="https://developer.android.com/preview/features/multi-window.html">multi-window mode support documentation</a> and meet the following requirements: 2792 </p> 2793 <ul> 2794 <li> 2795 Applications can indicate whether they are capable of operating in 2796 multi-window mode in the AndroidManifest.xml file, either explicitly via the 2797 <a href="https://developer.android.com/reference/android/R.attr.html#resizeableActivity"> 2798 <code>android:resizeableActivity</code></a> 2799 attribute or implicitly by having the targetSdkVersion > 24. Apps that 2800 explicitly set this attribute to false in their manifest MUST not be 2801 launched in multi-window mode. Apps that don't set the attribute in their 2802 manifest file (targetSdkVersion < 24) can be launched in multi-window mode, 2803 but the system MUST provide warning that the app may not work as expected in 2804 multi-window mode. 2805 </li> 2806 <li> 2807 Device implementations MUST NOT offer split-screen or freeform mode 2808 if both the screen height and width is less than 440 dp. 2809 </li> 2810 <li> 2811 Device implementations with screen size 2812 <code> 2813 xlarge 2814 </code> 2815 SHOULD support freeform mode. 2816 </li> 2817 <li> 2818 Android Television device implementations MUST support picture-in-picture (PIP) mode multi-window 2819 and place the PIP multi-window in the top right corner when PIP is ON. 2820 </li> 2821 <li> 2822 Device implementations with PIP mode multi-window support 2823 MUST allocate at least 240x135 dp for the PIP window. 2824 </li> 2825 <li> 2826 If the PIP multi-window mode is supported the 2827 <a href="https://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_WINDOW"> 2828 <code>KeyEvent.KEYCODE_WINDOW</code></a> key MUST be used to control the PIP window; otherwise, the key MUST be 2829 available to the foreground activity. 2830 </li> 2831 </ul> 2832 <h2 id="3_9_device_administration"> 2833 3.9. Device Administration 2834 </h2> 2835 <p> 2836 Android includes features that allow security-aware applications to perform 2837device administration functions at the system level, such as enforcing password 2838policies or performing remote wipe, through the 2839 <a href="http://developer.android.com/guide/topics/admin/device-admin.html">Android Device Administration API</a> ]. 2840Device implementations MUST provide an implementation of the 2841 <a href="http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html">DevicePolicyManager</a> class. Device implementations that supports a secure lock screen MUST implement 2842the full range of 2843 <a href="http://developer.android.com/guide/topics/admin/device-admin.html">device administration</a> policies defined in the Android SDK documentation and report the platform 2844feature android.software.device_admin. 2845 </p> 2846 <h3 id="3_9_1_device_provisioning"> 2847 3.9.1 Device Provisioning 2848 </h3> 2849 <h4 id="3_9_1_1_device_owner_provisioning"> 2850 3.9.1.1 Device owner provisioning 2851 </h4> 2852 <p> 2853 If a device implementation declares the 2854 <code> 2855 android.software.device_admin 2856 </code> 2857 feature 2858then it MUST implement the provisioning of the 2859 <a href="http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html#isDeviceOwnerApp(java.lang.String)">Device Owner app</a> of a Device Policy Client (DPC) application as indicated below: 2860 </p> 2861 <ul> 2862 <li> 2863 When the device implementation has no user data configured yet, it: 2864 <ul> 2865 <li> 2866 MUST report 2867 <code> 2868 true 2869 </code> 2870 for 2871 <a href="https://developer.android.com/reference/android/app/admin/DevicePolicyManager.html#isProvisioningAllowed(java.lang.String)"> 2872 DevicePolicyManager.isProvisioningAllowed(ACTION_PROVISION_MANAGED_DEVICE)</a>. 2873 </li> 2874 <li> 2875 MUST enroll the DPC application as the Device Owner app in response to 2876 the intent action 2877 <a href="http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html#ACTION_PROVISION_MANAGED_DEVICE"> 2878 android.app.action.PROVISION_MANAGED_DEVICE</a>. 2879 </li> 2880 <li> 2881 MUST enroll the DPC application as the Device Owner app if the device 2882 declares Near-Field Communications (NFC) support via the feature flag 2883 android.hardware.nfc and receives an NFC message containing a record 2884 with MIME type 2885 <a href="https://developer.android.com/reference/android/app/admin/DevicePolicyManager.html#MIME_TYPE_PROVISIONING_NFC"> 2886 MIME_TYPE_PROVISIONING_NFC</a>. 2887 </li> 2888 </ul> 2889 </li> 2890 <li> 2891 When the device implementation has user data, it: 2892 <ul> 2893 <li> 2894 MUST report 2895 <code> 2896 false 2897 </code> 2898 for the 2899 <a href="https://developer.android.com/reference/android/app/admin/DevicePolicyManager.html#isProvisioningAllowed(java.lang.String)"> 2900 DevicePolicyManager.isProvisioningAllowed(ACTION_PROVISION_MANAGED_DEVICE)</a>. 2901 </li> 2902 <li> 2903 MUST not enroll any DPC application as the Device Owner App any more. 2904 </li> 2905 </ul> 2906 </li> 2907 </ul> 2908 <p> 2909 Device implementations MAY have a preinstalled application performing device 2910administration functions but this application MUST NOT be set as the Device 2911Owner app without explicit consent or action from the user or the administrator 2912of the device. 2913 </p> 2914 <h4 id="3_9_1_2_managed_profile_provisioning"> 2915 3.9.1.2 Managed profile provisioning 2916 </h4> 2917 <p> 2918 If a device implementation declares the android.software.managed_users, it MUST 2919be possible to enroll a Device Policy Controller (DPC) application as the 2920 <a href="http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html#isProfileOwnerApp(java.lang.String)">owner of a new Managed Profile</a>. 2921 </p> 2922 <p> 2923 The managed profile provisioning process (the flow initiated by 2924 <a href="http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html#ACTION_PROVISION_MANAGED_PROFILE">android.app.action.PROVISION_MANAGED_PROFILE</a> ) 2925user experience MUST align with the AOSP implementation. 2926 </p> 2927 <p> 2928 Device implementations MUST provide the following user affordances within the 2929Settings user interface to indicate to the user when a particular system function 2930has been disabled by the Device Policy Controller (DPC): 2931 </p> 2932 <ul> 2933 <li> 2934 A consistent icon or other user affordance (for example the upstream AOSP 2935 info icon) to represent when a particular setting is restricted by a 2936 Device Admin. 2937 </li> 2938 <li> 2939 A short explanation message, as provided by the Device Admin via the 2940 <a href="https://developer.android.com/reference/android/app/admin/DevicePolicyManager.html#setShortSupportMessage%28android.content.ComponentName, java.lang.CharSequence%29"> 2941 <code> setShortSupportMessage</code></a>. 2942 </li> 2943 <li> 2944 The DPC application’s icon. 2945 </li> 2946 </ul> 2947 <h2 id="3_9_2_managed_profile_support"> 2948 3.9.2 Managed Profile Support 2949 </h2> 2950 <p> 2951 Managed profile capable devices are those devices that: 2952 </p> 2953 <ul> 2954 <li> 2955 Declare android.software.device_admin (see 2956 <a href="#3_9_device_administration">section 3.9 Device Administration</a> ). 2957 </li> 2958 <li> 2959 Are not low RAM devices (see 2960 <a href="#7_6_1_minimum_memory_and_storage">section 7.6.1</a> ). 2961 </li> 2962 <li> 2963 Allocate internal (non-removable) storage as shared storage (see 2964 <a href="#7_6_2_application_shared_storage">section 7.6.2</a> ). 2965 </li> 2966 </ul> 2967 <p> 2968 Managed profile capable devices MUST: 2969 </p> 2970 <ul> 2971 <li> 2972 Declare the platform feature flag 2973 <code> 2974 android.software.managed_users 2975 </code>. 2976 </li> 2977 <li> 2978 Support managed profiles via the 2979 <code> 2980 android.app.admin.DevicePolicyManager 2981 </code> 2982 APIs. 2983 </li> 2984 <li> 2985 Allow one and only 2986 <a href="http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html#ACTION_PROVISION_MANAGED_PROFILE">one managed profile to be created</a>. 2987 </li> 2988 <li> 2989 Use an icon badge (similar to the AOSP upstream work badge) to represent the 2990 managed applications and widgets and other badged UI elements like 2991 Recents & Notifications. 2992 </li> 2993 <li> 2994 Display a notification icon (similar to the AOSP upstream work badge) to 2995 indicate when user is within a managed profile application. 2996 </li> 2997 <li> 2998 Display a toast indicating that the user is in the managed profile if and 2999 when the device wakes up (ACTION_USER_PRESENT) and the foreground 3000 application is within the managed profile. 3001 </li> 3002 <li> 3003 Where a managed profile exists, show a visual affordance in the Intent 3004 'Chooser' to allow the user to forward the intent from the managed profile 3005 to the primary user or vice versa, if enabled by the Device Policy 3006 Controller. 3007 </li> 3008 <li> 3009 Where a managed profile exists, expose the following user affordances for 3010 both the primary user and the managed profile: 3011 <ul> 3012 <li> 3013 Separate accounting for battery, location, mobile data and storage usage 3014 for the primary user and managed profile. 3015 </li> 3016 <li> 3017 Independent management of VPN Applications installed within the primary 3018 user or managed profile. 3019 </li> 3020 <li> 3021 Independent management of applications installed within the primary user 3022 or managed profile. 3023 </li> 3024 <li> 3025 Independent management of accounts within the primary user or managed 3026 profile. 3027 </li> 3028 </ul> 3029 </li> 3030 <li> 3031 Ensure the preinstalled dialer, contacts and messaging applications can 3032 search for and look up caller information from the managed profile (if one 3033 exists) alongside those from the primary profile, if the Device Policy 3034 Controller permits it. When contacts from the managed profile are displayed 3035 in the preinstalled call log, in-call UI, in-progress and missed-call 3036 notifications, contacts and messaging apps they SHOULD be badged with the 3037 same badge used to indicate managed profile applications. 3038 </li> 3039 <li> 3040 MUST ensure that it satisfies all the security requirements applicable for a 3041 device with multiple users enabled (see 3042 <a href="#9_5_multi-user_support">section 9.5</a> ), 3043 even though the managed profile is not counted as another user in addition 3044 to the primary user. 3045 </li> 3046 <li> 3047 Support the ability to specify a separate lock screen meeting the following 3048 requirements to grant access to apps running in a managed profile. 3049 <ul> 3050 <li> 3051 Device implementations MUST honor the 3052 <a href="https://developer.android.com/reference/android/app/admin/DevicePolicyManager.html#ACTION_SET_NEW_PASSWORD"> 3053 <code>DevicePolicyManager.ACTION_SET_NEW_PASSWORD</code></a> 3054 intent and show an interface to configure a separate lock screen 3055 credential for the managed profile. 3056 </li> 3057 <li> 3058 The lock screen credentials of the managed profile MUST use the same 3059 credential storage and management mechanisms as the parent profile, 3060 as documented on the 3061 <a href="http://source.android.com/security/authentication/index.html">Android Open Source Project Site</a> </li> 3062 <li> 3063 The DPC 3064 <a href="https://developer.android.com/guide/topics/admin/device-admin.html#pwd">password policies</a> MUST apply to only the managed profile's lock screen credentials unless 3065 called upon the 3066 <code> 3067 DevicePolicyManager 3068 </code> 3069 instance returned by 3070 <a href="https://developer.android.com/reference/android/app/admin/DevicePolicyManager.html#getParentProfileInstance(android.content.ComponentName)">getParentProfileInstance</a>. 3071 </li> 3072 </ul> 3073 </li> 3074 </ul> 3075 <h2 id="3_10_accessibility"> 3076 3.10. Accessibility 3077 </h2> 3078 <p> 3079 Android provides an accessibility layer that helps users with disabilities to 3080navigate their devices more easily. In addition, Android provides platform APIs 3081that enable 3082 <a href="http://developer.android.com/reference/android/accessibilityservice/AccessibilityService.html">accessibility service implementations</a> to receive callbacks for user and system events and generate alternate feedback 3083mechanisms, such as text-to-speech, haptic feedback, and trackball/d-pad 3084navigation. 3085 </p> 3086 <p> 3087 Device implementations include the following requirements: 3088 </p> 3089 <ul> 3090 <li> 3091 Android Automotive implementations SHOULD provide an implementation of the 3092 Android accessibility framework consistent with the default Android 3093 implementation. 3094 </li> 3095 <li> 3096 Device implementations (Android Automotive excluded) MUST provide an 3097 implementation of the Android accessibility framework consistent with the 3098 default Android implementation. 3099 </li> 3100 <li> 3101 Device implementations (Android Automotive excluded) MUST support 3102 third-party accessibility service implementations through the 3103 <a href="http://developer.android.com/reference/android/view/accessibility/package-summary.html">android.accessibilityservice APIs</a>. 3104 </li> 3105 <li> 3106 Device implementations (Android Automotive excluded) MUST generate 3107 AccessibilityEvents and deliver these events to all registered 3108 AccessibilityService implementations in a manner consistent with the default 3109 Android implementation 3110 </li> 3111 <li> 3112 <p> 3113 Device implementations (Android Automotive and Android Watch devices with no 3114 audio output excluded), MUST provide a user-accessible mechanism to enable 3115 and disable accessibility services, and MUST display this interface in 3116 response to the android.provider.Settings.ACTION_ACCESSIBILITY_SETTINGS 3117 intent. 3118 </p> 3119 </li> 3120 <li> 3121 <p> 3122 Android device implementations with audio output are STRONGLY RECOMMENDED to provide 3123 implementations of accessibility services on the device comparable in or exceeding functionality 3124 of the TalkBack** and Switch Access accessibility services (https://github.com/google/talkback). 3125 </p> 3126 </li> 3127 <li> 3128 Android Watch devices with audio output SHOULD provide implementations of an accessibility service 3129 on the device comparable in or exceeding functionality of the TalkBack accessibility service 3130 (https://github.com/google/talkback). 3131 </li> 3132 <li> 3133 Device implementations SHOULD provide a mechanism in the out-of-box setup flow for users to enable 3134 relevant accessibility services, as well as options to adjust the font size, display size and 3135 magnification gestures. 3136 </li> 3137 </ul> 3138 <p> 3139 ** For languages supported by Text-to-speech. 3140 </p> 3141 <p> 3142 Also, note that if there is a preloaded accessibility service, it MUST be a Direct Boot aware 3143{directBootAware} app if the device has encrypted storage using File Based 3144Encryption (FBE). 3145 </p> 3146 <h2 id="3_11_text-to-speech"> 3147 3.11. Text-to-Speech 3148 </h2> 3149 <p> 3150 Android includes APIs that allow applications to make use of text-to-speech 3151(TTS) services and allows service providers to provide implementations of TTS 3152services. Device implementations reporting the feature 3153android.hardware.audio.output MUST meet these requirements related to the 3154 <a href="http://developer.android.com/reference/android/speech/tts/package-summary.html">Android TTS framework</a>. 3155 </p> 3156 <p> 3157 Android Automotive implementations: 3158 </p> 3159 <ul> 3160 <li> 3161 MUST support the Android TTS framework APIs. 3162 </li> 3163 <li> 3164 MAY support installation of third-party TTS engines. If supported, partners 3165 MUST provide a user-accessible interface that allows the user to select a 3166 TTS engine for use at system level. 3167 </li> 3168 </ul> 3169 <p> 3170 All other device implementations: 3171 </p> 3172 <ul> 3173 <li> 3174 MUST support the Android TTS framework APIs and SHOULD include a TTS engine 3175 supporting the languages available on the device. Note that the upstream 3176 Android open source software includes a full-featured TTS engine 3177 implementation. 3178 </li> 3179 <li> 3180 MUST support installation of third-party TTS engines. 3181 </li> 3182 <li> 3183 MUST provide a user-accessible interface that allows users to select a TTS 3184 engine for use at the system level. 3185 </li> 3186 </ul> 3187 <h2 id="3_12_tv_input_framework"> 3188 3.12. TV Input Framework 3189 </h2> 3190 <p> 3191 The 3192 <a href="http://source.android.com/devices/tv/index.html">Android Television Input Framework (TIF)</a> simplifies the delivery of live content to Android Television devices. TIF 3193provides a standard API to create input modules that control Android Television 3194devices. Android Television device implementations MUST support TV Input 3195Framework. 3196 </p> 3197 <p> 3198 Device implementations that support TIF MUST declare the platform feature 3199android.software.live_tv. 3200 </p> 3201 <h3 id="3_12_1_tv_app"> 3202 3.12.1. TV App 3203 </h3> 3204 <p> 3205 Any device implementation that declares support for Live TV MUST have an 3206installed TV application (TV App). The Android Open Source Project provides an 3207implementation of the TV App. 3208 </p> 3209 <p> 3210 The TV App MUST provide facilities to install and use 3211 <a href="http://developer.android.com/reference/android/media/tv/TvContract.Channels.html">TV Channels</a> and meet the following requirements: 3212 </p> 3213 <ul> 3214 <li> 3215 Device implementations MUST allow third-party TIF-based inputs 3216 (<a href="https://source.android.com/devices/tv/index.html#third-party_input_example">third-party inputs</a>) 3217 to be installed and managed. 3218 </li> 3219 <li> 3220 Device implementations MAY provide visual separation between pre-installed 3221 <a href="https://source.android.com/devices/tv/index.html#tv_inputs">TIF-based inputs</a> (installed inputs) and third-party inputs. 3222 </li> 3223 <li> 3224 Device implementations MUST NOT display the third-party inputs more than a 3225 single navigation action away from the TV App (i.e. expanding a list of 3226 third-party inputs from the TV App). 3227 </li> 3228 </ul> 3229 <h4 id="3_12_1_1_electronic_program_guide"> 3230 3.12.1.1. Electronic Program Guide 3231 </h4> 3232 <p> 3233 Android Television device implementations MUST show an informational and 3234interactive overlay, which MUST include an electronic program guide (EPG) 3235generated from the values in the 3236 <a href="https://developer.android.com/reference/android/media/tv/TvContract.Programs.html">TvContract.Programs</a> fields. The EPG MUST meet the following requirements: 3237 </p> 3238 <ul> 3239 <li> 3240 The EPG MUST display information from all installed inputs and third-party 3241 inputs. 3242 </li> 3243 <li> 3244 The EPG MAY provide visual separation between the installed inputs and 3245 third-party inputs. 3246 </li> 3247 <li> 3248 The EPG is STRONGLY RECOMMENDED to display installed inputs and third-party 3249 inputs with equal prominence. The EPG MUST NOT display the third-party 3250 inputs more than a single navigation action away from the installed inputs 3251 on the EPG. 3252 </li> 3253 <li> 3254 On channel change, device implementations MUST display EPG data for the 3255 currently playing program. 3256 </li> 3257 </ul> 3258 <h4 id="3_12_1_2_navigation"> 3259 3.12.1.2. Navigation 3260 </h4> 3261 <p> 3262 The TV App MUST allow navigation for the following functions via the D-pad, 3263Back, and Home keys on the Android Television device’s input device(s) 3264(i.e. remote control, remote control application, or game controller): 3265 </p> 3266 <ul> 3267 <li> 3268 Changing TV channels 3269 </li> 3270 <li> 3271 Opening EPG 3272 </li> 3273 <li> 3274 Configuring and tuning to third-party TIF-based inputs 3275 </li> 3276 <li> 3277 Opening Settings menu 3278 </li> 3279 </ul> 3280 <p> 3281 The TV App SHOULD pass key events to HDMI inputs through CEC. 3282 </p> 3283 <h4 id="3_12_1_3_tv_input_app_linking"> 3284 3.12.1.3. TV input app linking 3285 </h4> 3286 <p> 3287 Android Television device implementations MUST support 3288 <a href="http://developer.android.com/reference/android/media/tv/TvContract.Channels.html#COLUMN_APP_LINK_INTENT_URI">TV input app linking</a>, 3289which allows all inputs to provide activity links from the current activity to 3290another activity (i.e. a link from live programming to related content). The TV 3291App MUST show TV input app linking when it is provided. 3292 </p> 3293 <h4 id="3_12_1_4_time_shifting"> 3294 3.12.1.4. Time shifting 3295 </h4> 3296 <p> 3297 Android Television device implementations MUST support time shifting, which 3298allows the user to pause and resume live content. Device implementations MUST 3299provide the user a way to pause and resume the currently playing program, if 3300time shifting for that program 3301 <a href="https://developer.android.com/reference/android/media/tv/TvInputManager.html#TIME_SHIFT_STATUS_AVAILABLE">is available</a>. 3302 </p> 3303 <h4 id="3_12_1_5_tv_recording"> 3304 3.12.1.5. TV recording 3305 </h4> 3306 <p> 3307 Android Television device implementations are STRONGLY RECOMMENDED to support 3308TV recording. If the TV input supports recording, the EPG MAY provide a way to 3309 <a href="https://developer.android.com/reference/android/media/tv/TvInputInfo.html#canRecord()">record a program</a> if the recording of such a program is not 3310 <a href="https://developer.android.com/reference/android/media/tv/TvContract.Programs.html#COLUMN_RECORDING_PROHIBITED">prohibited</a>. 3311Device implementations SHOULD provide a user interface to play recorded programs. 3312 </p> 3313 <h2 id="3_13_quick_settings"> 3314 3.13. Quick Settings 3315 </h2> 3316 <p> 3317 Android device implementations SHOULD include a Quick Settings UI component that 3318allow quick access to frequently used or urgently needed actions. 3319 </p> 3320 <p> 3321 Android includes the 3322 <a href="https://developer.android.com/reference/android/service/quicksettings/package-summary.html"> 3323 <code>quicksettings</code></a> API allowing third party apps to implement tiles that can be added by the user 3324alongside the system-provided tiles in the Quick Settings UI component. If a 3325device implementation has a Quick Settings UI component, it: 3326 </p> 3327 <ul> 3328 <li> 3329 MUST allow the user to add or remove tiles from a third-party app to Quick 3330 Settings. 3331 </li> 3332 <li> 3333 MUST NOT automatically add a tile from a third-party app directly to Quick 3334 Settings. 3335 </li> 3336 <li> 3337 MUST display all the user-added tiles from third-party apps alongside the 3338 system-provided quick setting tiles. 3339 </li> 3340 </ul> 3341 <h2 id="3_14_vehicle_ui_apis"> 3342 3.14. Vehicle UI APIs 3343 </h2> 3344 <h3 id="3_14_1__vehicle_media_ui"> 3345 3.14.1. Vehicle Media UI 3346 </h3> 3347 <p> 3348 Any device implementation that 3349 <a href="https://developer.android.com/reference/android/content/pm/PackageManager.html?#FEATURE_AUTOMOTIVE?">declares automotive support</a> MUST include a UI framework to support third-party apps consuming the 3350 <a href="http://developer.android.com/reference/android/media/browse/MediaBrowser.html">MediaBrowser</a> and 3351 <a href="http://developer.android.com/reference/android/media/session/MediaSession.html">MediaSession</a> APIs. 3352 </p> 3353 <p> 3354 The UI framework supporting third-party apps that depend on MediaBrowser and 3355MediaSession has the following visual requirements: 3356 </p> 3357 <ul> 3358 <li> 3359 MUST display 3360 <a href="http://developer.android.com/reference/android/media/browse/MediaBrowser.MediaItem.html">MediaItem</a> icons and notification icons unaltered. 3361 </li> 3362 <li> 3363 MUST display those items as described by MediaSession, e.g., metadata, icons, 3364 imagery. 3365 </li> 3366 <li> 3367 MUST show app title. 3368 </li> 3369 <li> 3370 MUST have drawer to present 3371 <a href="http://developer.android.com/reference/android/media/browse/MediaBrowser.html">MediaBrowser</a> hierarchy. 3372 </li> 3373 </ul> 3374 <h1 id="4_application_packaging_compatibility"> 3375 4. Application Packaging Compatibility 3376 </h1> 3377 <p> 3378 Device implementations MUST install and run Android “.apk” files as generated 3379by the “aapt” tool included in the 3380 <a href="http://developer.android.com/tools/help/index.html"> 3381 official Android 3382SDK 3383 </a> 3384 . For this reason device 3385implementations SHOULD use the reference implementation’s package management 3386system. 3387 </p> 3388 <p> 3389 The package manager MUST support verifying “.apk” files using the 3390 <a href="https://source.android.com/security/apksigning/v2.html"> 3391 APK Signature 3392Scheme v2 3393 </a> 3394 . 3395 </p> 3396 <p> 3397 Devices implementations MUST NOT extend either the 3398 <a href="http://developer.android.com/guide/components/fundamentals.html">.apk</a>, 3399 <a href="http://developer.android.com/guide/topics/manifest/manifest-intro.html">Android Manifest</a>, 3400 <a href="https://android.googlesource.com/platform/dalvik/">Dalvik bytecode</a>, or 3401RenderScript bytecode formats in such a way that would prevent those files from 3402installing and running correctly on other compatible devices. 3403 </p> 3404 <h1 id="5_multimedia_compatibility"> 3405 5. Multimedia Compatibility 3406 </h1> 3407 <h2 id="5_1_media_codecs"> 3408 5.1. Media Codecs 3409 </h2> 3410 <p> 3411 Device implementations— 3412 </p> 3413 <ul> 3414 <li> 3415 <p> 3416 MUST support the 3417 <a href="http://developer.android.com/guide/appendix/media-formats.html"> 3418 core media formats </a> specified in the Android SDK documentation, except where explicitly permitted 3419in this document. 3420 </p> 3421 </li> 3422 <li> 3423 <p> 3424 MUST support the media formats, encoders, decoders, file types, and 3425container formats defined in the tables below and reported via 3426 <a href="http://developer.android.com/reference/android/media/MediaCodecList.html">MediaCodecList</a>. 3427 </p> 3428 </li> 3429 <li> 3430 <p> 3431 MUST also be able to decode all profiles reported in its 3432 <a href="http://developer.android.com/reference/android/media/CamcorderProfile.html">CamcorderProfile</a>.</p> 3433 </li> 3434 <li> 3435 <p> 3436 MUST be able to decode all formats it can encode. This includes all 3437 bitstreams that its encoders generate. 3438 </p> 3439 </li> 3440 </ul> 3441 <p> 3442 Codecs SHOULD aim for minimum codec latency, in other words, codecs— 3443 </p> 3444 <ul> 3445 <li> 3446 SHOULD NOT consume and store input buffers and return input buffers only 3447once processed 3448 </li> 3449 <li> 3450 SHOULD NOT hold onto decoded buffers for longer than as specified by the 3451standard (e.g. SPS). 3452 </li> 3453 <li> 3454 SHOULD NOT hold onto encoded buffers longer than required by the GOP 3455structure. 3456 </li> 3457 </ul> 3458 <p> 3459 All of the codecs listed in the table below are provided as software 3460implementations in the preferred Android implementation from the Android Open 3461Source Project. 3462 </p> 3463 <p> 3464 Please note that neither Google nor the Open Handset Alliance make any 3465representation that these codecs are free from third-party patents. Those 3466intending to use this source code in hardware or software products are advised 3467that implementations of this code, including in open source software or 3468shareware, may require patent licenses from the relevant patent holders. 3469 </p> 3470 <h3 id="5_1_1_audio_codecs"> 3471 5.1.1. Audio Codecs 3472 </h3> 3473 <table> 3474 <tr> 3475 <th> 3476 Format/Codec 3477 </th> 3478 <th> 3479 Encoder 3480 </th> 3481 <th> 3482 Decoder 3483 </th> 3484 <th> 3485 Details 3486 </th> 3487 <th> 3488 Supported File Types/Container Formats 3489 </th> 3490 </tr> 3491 <tr> 3492 <td> 3493 MPEG-4 AAC Profile 3494 <br/> 3495 (AAC LC) 3496 </td> 3497 <td> 3498 REQUIRED 3499 <sup> 3500 1 3501 </sup> 3502 </td> 3503 <td> 3504 REQUIRED 3505 </td> 3506 <td> 3507 Support for mono/stereo/5.0/5.1 3508 <sup> 3509 2 3510 </sup> 3511 content with standard 3512 sampling rates from 8 to 48 kHz. 3513 </td> 3514 <td> 3515 <ul> 3516 <li class="table_list"> 3517 3GPP (.3gp) 3518 </li> 3519 <li class="table_list"> 3520 MPEG-4 (.mp4, .m4a) 3521 </li> 3522 <li class="table_list"> 3523 ADTS raw AAC (.aac, decode in Android 3.1+, encode in 3524 Android 4.0+, ADIF not supported) 3525 </li> 3526 <li class="table_list"> 3527 MPEG-TS (.ts, not seekable, Android 3.0+) 3528 </li> 3529 </ul> 3530 </td> 3531 </tr> 3532 <tr> 3533 <td> 3534 MPEG-4 HE AAC Profile (AAC+) 3535 </td> 3536 <td> 3537 REQUIRED 3538 <sup> 3539 1 3540 </sup> 3541 <br/> 3542 (Android 4.1+) 3543 </td> 3544 <td> 3545 REQUIRED 3546 </td> 3547 <td> 3548 Support for mono/stereo/5.0/5.1 3549 <sup> 3550 2 3551 </sup> 3552 content with standard 3553 sampling rates from 16 to 48 kHz. 3554 </td> 3555 <td> 3556 </td> 3557 </tr> 3558 <tr> 3559 <td> 3560 MPEG-4 HE AACv2 3561 <br/> 3562 Profile (enhanced AAC+) 3563 </td> 3564 <td> 3565 </td> 3566 <td> 3567 REQUIRED 3568 </td> 3569 <td> 3570 Support for mono/stereo/5.0/5.1 3571 <sup> 3572 2 3573 </sup> 3574 content with standard 3575 sampling rates from 16 to 48 kHz. 3576 </td> 3577 <td> 3578 </td> 3579 </tr> 3580 <tr> 3581 <td> 3582 AAC ELD (enhanced low delay AAC) 3583 </td> 3584 <td> 3585 REQUIRED 3586 <sup> 3587 1 3588 </sup> 3589 <br/> 3590 (Android 4.1+) 3591 </td> 3592 <td> 3593 REQUIRED 3594 <br/> 3595 (Android 4.1+) 3596 </td> 3597 <td> 3598 Support for mono/stereo content with standard sampling rates from 16 to 3599 48 kHz. 3600 </td> 3601 <td> 3602 </td> 3603 </tr> 3604 <tr> 3605 <td> 3606 AMR-NB 3607 </td> 3608 <td> 3609 REQUIRED 3610 <sup> 3611 3 3612 </sup> 3613 </td> 3614 <td> 3615 REQUIRED 3616 <sup> 3617 3 3618 </sup> 3619 </td> 3620 <td> 3621 4.75 to 12.2 kbps sampled @ 8 kHz 3622 </td> 3623 <td> 3624 3GPP (.3gp) 3625 </td> 3626 </tr> 3627 <tr> 3628 <td> 3629 AMR-WB 3630 </td> 3631 <td> 3632 REQUIRED 3633 <sup> 3634 3 3635 </sup> 3636 </td> 3637 <td> 3638 REQUIRED 3639 <sup> 3640 3 3641 </sup> 3642 </td> 3643 <td> 3644 9 rates from 6.60 kbit/s to 23.85 kbit/s sampled @ 16 kHz 3645 </td> 3646 <td> 3647 </td> 3648 </tr> 3649 <tr> 3650 <td> 3651 FLAC 3652 </td> 3653 <td> 3654 </td> 3655 <td> 3656 REQUIRED 3657 <br/> 3658 (Android 3.1+) 3659 </td> 3660 <td> 3661 Mono/Stereo (no multichannel). Sample rates up to 48 kHz (but up to 44.1 3662 kHz is RECOMMENDED on devices with 44.1 kHz output, as the 48 to 44.1 kHz 3663 downsampler does not include a low-pass filter). 16-bit RECOMMENDED; no 3664 dither applied for 24-bit. 3665 </td> 3666 <td> 3667 FLAC (.flac) only 3668 </td> 3669 </tr> 3670 <tr> 3671 <td> 3672 MP3 3673 </td> 3674 <td> 3675 </td> 3676 <td> 3677 REQUIRED 3678 </td> 3679 <td> 3680 Mono/Stereo 8-320Kbps constant (CBR) or variable bitrate (VBR) 3681 </td> 3682 <td> 3683 MP3 (.mp3) 3684 </td> 3685 </tr> 3686 <tr> 3687 <td> 3688 MIDI 3689 </td> 3690 <td> 3691 </td> 3692 <td> 3693 REQUIRED 3694 </td> 3695 <td> 3696 MIDI Type 0 and 1. DLS Version 1 and 2. XMF and Mobile XMF. Support for 3697 ringtone formats RTTTL/RTX, OTA, and iMelody 3698 </td> 3699 <td> 3700 <ul> 3701 <li class="table_list"> 3702 Type 0 and 1 (.mid, .xmf, .mxmf) 3703 </li> 3704 <li class="table_list"> 3705 RTTTL/RTX (.rtttl, .rtx) 3706 </li> 3707 <li class="table_list"> 3708 OTA (.ota) 3709 </li> 3710 <li class="table_list"> 3711 iMelody (.imy) 3712 </li> 3713 </ul> 3714 </td> 3715 </tr> 3716 <tr> 3717 <td> 3718 Vorbis 3719 </td> 3720 <td> 3721 </td> 3722 <td> 3723 REQUIRED 3724 </td> 3725 <td> 3726 </td> 3727 <td> 3728 <ul> 3729 <li class="table_list"> 3730 Ogg (.ogg) 3731 </li> 3732 <li class="table_list"> 3733 Matroska (.mkv, Android 4.0+) 3734 </li> 3735 </ul> 3736 </td> 3737 </tr> 3738 <tr> 3739 <td> 3740 PCM/WAVE 3741 </td> 3742 <td> 3743 REQUIRED 3744 <sup> 3745 4 3746 </sup> 3747 <br/> 3748 (Android 4.1+) 3749 </td> 3750 <td> 3751 REQUIRED 3752 </td> 3753 <td> 3754 16-bit linear PCM (rates up to limit of hardware). Devices MUST support 3755 sampling rates for raw PCM recording at 8000, 11025, 16000, and 44100 Hz 3756 frequencies. 3757 </td> 3758 <td> 3759 WAVE (.wav) 3760 </td> 3761 </tr> 3762 <tr> 3763 <td> 3764 Opus 3765 </td> 3766 <td> 3767 </td> 3768 <td> 3769 REQUIRED 3770 <br/> 3771 (Android 5.0+) 3772 </td> 3773 <td> 3774 </td> 3775 <td> 3776 Matroska (.mkv), Ogg(.ogg) 3777 </td> 3778 </tr> 3779 </table> 3780 <p class="table_footnote"> 3781 1 Required for device implementations that define 3782android.hardware.microphone but optional for Android Watch device 3783implementations. 3784 </p> 3785 <p class="table_footnote"> 3786 2 Recording or playback MAY be performed in mono 3787or stereo, but the decoding of AAC input buffers of multichannel streams 3788(i.e. more than two channels) to PCM through the default AAC audio decoder 3789in the android.media.MediaCodec API, the following MUST be supported: 3790 </p> 3791 <ul class="table_footnote"> 3792 <li> 3793 decoding is performed without downmixing (e.g. a 5.0 AAC stream must be 3794decoded to five channels of PCM, a 5.1 AAC stream must be decoded to six 3795channels of PCM), 3796 </li> 3797 <li> 3798 dynamic range metadata, as defined in "Dynamic Range Control (DRC)" 3799in ISO/IEC 14496-3, and the android.media.MediaFormat DRC keys to 3800configure the dynamic range-related behaviors of the audio decoder. The 3801AAC DRC keys were introduced in API 21,and are: 3802KEY_AAC_DRC_ATTENUATION_FACTOR, KEY_AAC_DRC_BOOST_FACTOR, 3803KEY_AAC_DRC_HEAVY_COMPRESSION, KEY_AAC_DRC_TARGET_REFERENCE_LEVEL and 3804KEY_AAC_ENCODED_TARGET_LEVEL 3805 </li> 3806 </ul> 3807 <p class="table_footnote"> 3808 3 Required for Android Handheld device 3809implementations. 3810 </p> 3811 <p class="table_footnote"> 3812 4 Required for device implementations that define 3813android.hardware.microphone, including Android Watch device implementations. 3814 </p> 3815 <h3 id="5_1_2_image_codecs"> 3816 5.1.2. Image Codecs 3817 </h3> 3818 <table> 3819 <tr> 3820 <th> 3821 Format/Codec 3822 </th> 3823 <th> 3824 Encoder 3825 </th> 3826 <th> 3827 Decoder 3828 </th> 3829 <th> 3830 Details 3831 </th> 3832 <th> 3833 Supported File Types/Container Formats 3834 </th> 3835 </tr> 3836 <tr> 3837 <td> 3838 JPEG 3839 </td> 3840 <td> 3841 REQUIRED 3842 </td> 3843 <td> 3844 REQUIRED 3845 </td> 3846 <td> 3847 Base+progressive 3848 </td> 3849 <td> 3850 JPEG (.jpg) 3851 </td> 3852 </tr> 3853 <tr> 3854 <td> 3855 GIF 3856 </td> 3857 <td> 3858 </td> 3859 <td> 3860 REQUIRED 3861 </td> 3862 <td> 3863 </td> 3864 <td> 3865 GIF (.gif) 3866 </td> 3867 </tr> 3868 <tr> 3869 <td> 3870 PNG 3871 </td> 3872 <td> 3873 REQUIRED 3874 </td> 3875 <td> 3876 REQUIRED 3877 </td> 3878 <td> 3879 </td> 3880 <td> 3881 PNG (.png) 3882 </td> 3883 </tr> 3884 <tr> 3885 <td> 3886 BMP 3887 </td> 3888 <td> 3889 </td> 3890 <td> 3891 REQUIRED 3892 </td> 3893 <td> 3894 </td> 3895 <td> 3896 BMP (.bmp) 3897 </td> 3898 </tr> 3899 <tr> 3900 <td> 3901 WebP 3902 </td> 3903 <td> 3904 REQUIRED 3905 </td> 3906 <td> 3907 REQUIRED 3908 </td> 3909 <td> 3910 </td> 3911 <td> 3912 WebP (.webp) 3913 </td> 3914 </tr> 3915 <tr> 3916 <td> 3917 Raw 3918 </td> 3919 <td> 3920 </td> 3921 <td> 3922 REQUIRED 3923 </td> 3924 <td> 3925 </td> 3926 <td> 3927 ARW (.arw), CR2 (.cr2), DNG (.dng), NEF (.nef), NRW (.nrw), ORF (.orf), 3928 PEF (.pef), RAF (.raf), RW2 (.rw2), SRW (.srw) 3929 </td> 3930 </tr> 3931 </table> 3932 <h3 id="5_1_3_video_codecs"> 3933 5.1.3. Video Codecs 3934 </h3> 3935 <ul> 3936 <li> 3937 <p> 3938 Codecs advertising HDR profile support MUST support HDR static metadata 3939parsing and handling. 3940 </p> 3941 </li> 3942 <li> 3943 <p> 3944 If a media codec advertises intra refresh support, then it MUST support the 3945refresh periods in the range of 10 - 60 frames and accurately operate within 394620% of configured refresh period. 3947 </p> 3948 </li> 3949 <li> 3950 <p> 3951 Video codecs MUST support output and input bytebuffer sizes that 3952accommodate the largest feasible compressed and uncompressed frame as dictated 3953by the standard and configuration but also not overallocate. 3954 </p> 3955 </li> 3956 <li> 3957 <p> 3958 Video encoders and decoders MUST support YUV420 flexible color format 3959(COLOR_FormatYUV420Flexible). 3960 </p> 3961 </li> 3962 </ul> 3963 <table> 3964 <tr> 3965 <th> 3966 Format/Codec 3967 </th> 3968 <th> 3969 Encoder 3970 </th> 3971 <th> 3972 Decoder 3973 </th> 3974 <th> 3975 Details 3976 </th> 3977 <th> 3978 Supported File Types/ 3979 <br/> 3980 Container Formats 3981 </th> 3982 </tr> 3983 <tr> 3984 <td> 3985 H.263 3986 </td> 3987 <td> 3988 MAY 3989 </td> 3990 <td> 3991 MAY 3992 </td> 3993 <td> 3994 </td> 3995 <td> 3996 <ul> 3997 <li class="table_list"> 3998 3GPP (.3gp) 3999 </li> 4000 <li class="table_list"> 4001 MPEG-4 (.mp4) 4002 </li> 4003 </ul> 4004 </td> 4005 </tr> 4006 <tr> 4007 <td> 4008 H.264 AVC 4009 </td> 4010 <td> 4011 REQUIRED 4012 <sup> 4013 2 4014 </sup> 4015 </td> 4016 <td> 4017 REQUIRED 4018 <sup> 4019 2 4020 </sup> 4021 </td> 4022 <td> 4023 See 4024 <a href="#5_2_video_encoding">section 5.2</a> and 4025 <a href="#5_3_video_decoding">5.3</a> for details 4026 </td> 4027 <td> 4028 <ul> 4029 <li class="table_list"> 4030 3GPP (.3gp) 4031 </li> 4032 <li class="table_list"> 4033 MPEG-4 (.mp4) 4034 </li> 4035 <li class="table_list"> 4036 MPEG-2 TS (.ts, AAC audio only, not seekable, Android 4037 3.0+) 4038 </li> 4039 </ul> 4040 </td> 4041 </tr> 4042 <tr> 4043 <td> 4044 H.265 HEVC 4045 </td> 4046 <td> 4047 </td> 4048 <td> 4049 REQUIRED 4050 <sup> 4051 5 4052 </sup> 4053 </td> 4054 <td> 4055 See 4056 <a href="#5_3_video_decoding">section 5.3</a> for details 4057 </td> 4058 <td> 4059 MPEG-4 (.mp4) 4060 </td> 4061 </tr> 4062 <tr> 4063 <td> 4064 MPEG-2 4065 </td> 4066 <td> 4067 </td> 4068 <td> 4069 STRONGLY RECOMMENDED 4070 <sup> 4071 6 4072 </sup> 4073 </td> 4074 <td> 4075 Main Profile 4076 </td> 4077 <td> 4078 MPEG2-TS 4079 </td> 4080 </tr> 4081 <tr> 4082 <td> 4083 MPEG-4 SP 4084 </td> 4085 <td> 4086 </td> 4087 <td> 4088 REQUIRED 4089 <sup> 4090 2 4091 </sup> 4092 </td> 4093 <td> 4094 </td> 4095 <td> 4096 3GPP (.3gp) 4097 </td> 4098 </tr> 4099 <tr> 4100 <td> 4101 VP8 4102 <sup> 4103 3 4104 </sup> 4105 </td> 4106 <td> 4107 REQUIRED 4108 <sup> 4109 2 4110 </sup> 4111 <br/> 4112 (Android 4.3+) 4113 </td> 4114 <td> 4115 REQUIRED 4116 <sup> 4117 2 4118 </sup> 4119 <br/> 4120 (Android 2.3.3+) 4121 </td> 4122 <td> 4123 See 4124 <a href="#5_2_video_encoding">section 5.2</a> and 4125 <a href="#5_3_video_decoding">5.3</a> for details 4126 </td> 4127 <td> 4128 <ul> 4129 <li class="table_list"> 4130 <a href="http://www.webmproject.org/"> 4131 WebM 4132 (.webm) 4133 </a> 4134 </li> 4135 <li class="table_list"> 4136 Matroska (.mkv, Android 4.0+) 4137 <sup> 4138 4 4139 </sup> 4140 </li> 4141 </ul> 4142 </td> 4143 </tr> 4144 <tr> 4145 <td> 4146 VP9 4147 </td> 4148 <td> 4149 </td> 4150 <td> 4151 REQUIRED 4152 <sup> 4153 2 4154 </sup> 4155 <br/> 4156 (Android 4.4+) 4157 </td> 4158 <td> 4159 See 4160 <a href="#5_3_video_decoding">section 5.3</a> for details 4161 </td> 4162 <td> 4163 <ul> 4164 <li class="table_list"> 4165 <a href="http://www.webmproject.org/"> 4166 WebM 4167 (.webm) 4168 </a> 4169 </li> 4170 <li class="table_list"> 4171 Matroska (.mkv, Android 4.0+) 4172 <sup> 4173 4 4174 </sup> 4175 </li> 4176 </ul> 4177 </td> 4178 </tr> 4179 </table> 4180 <p class="table_footnote"> 4181 1 Required for device implementations that include 4182camera hardware and define android.hardware.camera or 4183android.hardware.camera.front. 4184 </p> 4185 <p class="table_footnote"> 4186 2 Required for device implementations except Android 4187Watch devices. 4188 </p> 4189 <p class="table_footnote"> 4190 3 For acceptable quality of web video streaming and 4191video-conference services, device implementations SHOULD use a hardware VP8 4192codec that meets the 4193 <a href="http://www.webmproject.org/hardware/rtc-coding-requirements/">requirements</a>. 4194 </p> 4195 <p class="table_footnote"> 4196 4 Device implementations SHOULD support writing 4197Matroska WebM files. 4198 </p> 4199 <p class="table_footnote"> 4200 5 STRONGLY RECOMMENDED for Android Automotive, 4201optional for Android Watch, and required for all other device types. 4202 </p> 4203 <p class="table_footnote"> 4204 6 Applies only to Android Television device 4205implementations. 4206 </p> 4207 <h2 id="5_2_video_encoding"> 4208 5.2. Video Encoding 4209 </h2> 4210 <div class="note"> 4211 Video codecs are optional for Android Watch device implementations. 4212 </div> 4213 <p> 4214 H.264, VP8, VP9 and HEVC video encoders— 4215 </p> 4216 <ul> 4217 <li> 4218 MUST support dynamically configurable bitrates. 4219 </li> 4220 <li> 4221 SHOULD support variable frame rates, where video encoder SHOULD determine 4222instantaneous frame duration based on the timestamps of input buffers, and 4223allocate its bit bucket based on that frame duration. 4224 </li> 4225 </ul> 4226 <p> 4227 H.263 and MPEG-4 video encoder SHOULD support dynamically configurable 4228bitrates. 4229 </p> 4230 <p> 4231 All video encoders SHOULD meet the following bitrate targets over two sliding 4232windows: 4233 </p> 4234 <ul> 4235 <li> 4236 It SHOULD be not more than ~15% over the bitrate between intraframe 4237(I-frame) intervals. 4238 </li> 4239 <li> 4240 It SHOULD be not more than ~100% over the bitrate over a sliding window of 42411 second. 4242 </li> 4243 </ul> 4244 <h3 id="5_2_1_h_263"> 4245 5.2.1. H.263 4246 </h3> 4247 <p> 4248 Android device implementations with H.263 encoders MUST support Baseline Profile Level 45. 4249 </p> 4250 <h3 id="5_2_2_h-264"> 4251 5.2.2. H-264 4252 </h3> 4253 <p> 4254 Android device implementations with H.264 codec support: 4255 </p> 4256 <ul> 4257 <li> 4258 MUST support Baseline Profile Level 3. 4259 <br/> 4260 However, support for ASO (Arbitrary Slice Ordering), FMO (Flexible Macroblock 4261 Ordering) and RS (Redundant Slices) is OPTIONAL. Moreover, to maintain 4262 compatibility with other Android devices, it is RECOMMENDED that ASO, FMO 4263 and RS are not used for Baseline Profile by encoders. 4264 </li> 4265 <li> 4266 MUST support the SD (Standard Definition) video encoding profiles in the following table. 4267 </li> 4268 <li> 4269 SHOULD support Main Profile Level 4. 4270 </li> 4271 <li> 4272 SHOULD support the HD (High Definition) video encoding profiles as indicated in the following table. 4273 </li> 4274 <li> 4275 In addition, Android Television devices are STRONGLY RECOMMENDED to encode HD 1080p video at 30 fps. 4276 </li> 4277 </ul> 4278 <table> 4279 <tr> 4280 <th> 4281 </th> 4282 <th> 4283 SD (Low quality) 4284 </th> 4285 <th> 4286 SD (High quality) 4287 </th> 4288 <th> 4289 HD 720p 4290 <sup> 4291 1 4292 </sup> 4293 </th> 4294 <th> 4295 HD 1080p 4296 <sup> 4297 1 4298 </sup> 4299 </th> 4300 </tr> 4301 <tr> 4302 <th> 4303 Video resolution 4304 </th> 4305 <td> 4306 320 x 240 px 4307 </td> 4308 <td> 4309 720 x 480 px 4310 </td> 4311 <td> 4312 1280 x 720 px 4313 </td> 4314 <td> 4315 1920 x 1080 px 4316 </td> 4317 </tr> 4318 <tr> 4319 <th> 4320 Video frame rate 4321 </th> 4322 <td> 4323 20 fps 4324 </td> 4325 <td> 4326 30 fps 4327 </td> 4328 <td> 4329 30 fps 4330 </td> 4331 <td> 4332 30 fps 4333 </td> 4334 </tr> 4335 <tr> 4336 <th> 4337 Video bitrate 4338 </th> 4339 <td> 4340 384 Kbps 4341 </td> 4342 <td> 4343 2 Mbps 4344 </td> 4345 <td> 4346 4 Mbps 4347 </td> 4348 <td> 4349 10 Mbps 4350 </td> 4351 </tr> 4352 </table> 4353 <p class="table_footnote"> 4354 1 When supported by hardware, but STRONGLY RECOMMENDED 4355for Android Television devices. 4356 </p> 4357 <h3 id="5_2_3_vp8"> 4358 5.2.3. VP8 4359 </h3> 4360 <p> 4361 Android device implementations with VP8 codec support MUST support the SD video 4362encoding profiles and SHOULD support the following HD (High Definition) video encoding profiles. 4363 </p> 4364 <table> 4365 <tr> 4366 <th> 4367 </th> 4368 <th> 4369 SD (Low quality) 4370 </th> 4371 <th> 4372 SD (High quality) 4373 </th> 4374 <th> 4375 HD 720p 4376 <sup> 4377 1 4378 </sup> 4379 </th> 4380 <th> 4381 HD 1080p 4382 <sup> 4383 1 4384 </sup> 4385 </th> 4386 </tr> 4387 <tr> 4388 <th> 4389 Video resolution 4390 </th> 4391 <td> 4392 320 x 180 px 4393 </td> 4394 <td> 4395 640 x 360 px 4396 </td> 4397 <td> 4398 1280 x 720 px 4399 </td> 4400 <td> 4401 1920 x 1080 px 4402 </td> 4403 </tr> 4404 <tr> 4405 <th> 4406 Video frame rate 4407 </th> 4408 <td> 4409 30 fps 4410 </td> 4411 <td> 4412 30 fps 4413 </td> 4414 <td> 4415 30 fps 4416 </td> 4417 <td> 4418 30 fps 4419 </td> 4420 </tr> 4421 <tr> 4422 <th> 4423 Video bitrate 4424 </th> 4425 <td> 4426 800 Kbps 4427 </td> 4428 <td> 4429 2 Mbps 4430 </td> 4431 <td> 4432 4 Mbps 4433 </td> 4434 <td> 4435 10 Mbps 4436 </td> 4437 </tr> 4438 </table> 4439 <p class="table_footnote"> 4440 1 When supported by hardware. 4441 </p> 4442 <h2 id="5_3_video_decoding"> 4443 5.3. Video Decoding 4444 </h2> 4445 <div class="note"> 4446 Video codecs are optional for Android Watch device implementations. 4447 </div> 4448 <p> 4449 Device implementations— 4450 </p> 4451 <ul> 4452 <li> 4453 <p> 4454 MUST support dynamic video resolution and frame rate switching through the 4455 standard Android APIs within the same stream for all VP8, VP9, H.264, and 4456 H.265 codecs in real time and up to the maximum resolution supported by each 4457 codec on the device. 4458 </p> 4459 </li> 4460 <li> 4461 <p> 4462 Implementations that support the Dolby Vision decoder— 4463 </p> 4464 </li> 4465 <li> 4466 MUST provide a Dolby Vision-capable extractor. 4467 </li> 4468 <li> 4469 <p> 4470 MUST properly display Dolby Vision content on the device screen or on a 4471 standard video output port (e.g., HDMI). 4472 </p> 4473 </li> 4474 <li> 4475 <p> 4476 Implementations that provide a Dolby Vision-capable extractor MUST set the 4477 track index of backward-compatible base-layer(s) (if present) to be the same 4478 as the combined Dolby Vision layer's track index. 4479 </p> 4480 </li> 4481 </ul> 4482 <h3 id="5_3_1_mpeg-2"> 4483 5.3.1. MPEG-2 4484 </h3> 4485 <p> 4486 Android device implementations with MPEG-2 decoders must support the Main 4487Profile High Level. 4488 </p> 4489 <h3 id="5_3_2_h_263"> 4490 5.3.2. H.263 4491 </h3> 4492 <p> 4493 Android device implementations with H.263 decoders MUST support Baseline Profile 4494Level 30 and Level 45. 4495 </p> 4496 <h3 id="5_3_3_mpeg-4"> 4497 5.3.3. MPEG-4 4498 </h3> 4499 <p> 4500 Android device implementations with MPEG-4 decoders MUST support Simple Profile 4501Level 3. 4502 </p> 4503 <h3 id="5_3_4_h_264"> 4504 5.3.4. H.264 4505 </h3> 4506 <p> 4507 Android device implementations with H.264 decoders: 4508 </p> 4509 <ul> 4510 <li> 4511 MUST support Main Profile Level 3.1 and Baseline Profile. 4512 <br/> 4513 Support for ASO (Arbitrary Slice Ordering), FMO (Flexible Macroblock Ordering) 4514 and RS (Redundant Slices) is OPTIONAL. 4515 </li> 4516 <li> 4517 MUST be capable of decoding videos with the SD (Standard Definition) 4518 profiles listed in the following table and encoded with the Baseline Profile and 4519 Main Profile Level 3.1 (including 720p30). 4520 </li> 4521 <li> 4522 SHOULD be capable of decoding videos with the HD (High Definition) profiles 4523 as indicated in the following table. 4524 </li> 4525 <li> 4526 In addition, Android Television devices— 4527 <ul> 4528 <li> 4529 MUST support High Profile Level 4.2 and the HD 1080p60 decoding profile. 4530 </li> 4531 <li> 4532 MUST be capable of decoding videos with both HD profiles as indicated 4533 in the following table and encoded with either the Baseline Profile, Main 4534 Profile, or the High Profile Level 4.2 4535 </li> 4536 </ul> 4537 </li> 4538 </ul> 4539 <table> 4540 <tr> 4541 <th> 4542 </th> 4543 <th> 4544 SD (Low quality) 4545 </th> 4546 <th> 4547 SD (High quality) 4548 </th> 4549 <th> 4550 HD 720p 4551 <sup> 4552 1 4553 </sup> 4554 </th> 4555 <th> 4556 HD 1080p 4557 <sup> 4558 1 4559 </sup> 4560 </th> 4561 </tr> 4562 <tr> 4563 <th> 4564 Video resolution 4565 </th> 4566 <td> 4567 320 x 240 px 4568 </td> 4569 <td> 4570 720 x 480 px 4571 </td> 4572 <td> 4573 1280 x 720 px 4574 </td> 4575 <td> 4576 1920 x 1080 px 4577 </td> 4578 </tr> 4579 <tr> 4580 <th> 4581 Video frame rate 4582 </th> 4583 <td> 4584 30 fps 4585 </td> 4586 <td> 4587 30 fps 4588 </td> 4589 <td> 4590 60 fps 4591 </td> 4592 <td> 4593 30 fps (60 fps 4594 <sup> 4595 2 4596 </sup> 4597 ) 4598 </td> 4599 </tr> 4600 <tr> 4601 <th> 4602 Video bitrate 4603 </th> 4604 <td> 4605 800 Kbps 4606 </td> 4607 <td> 4608 2 Mbps 4609 </td> 4610 <td> 4611 8 Mbps 4612 </td> 4613 <td> 4614 20 Mbps 4615 </td> 4616 </tr> 4617 </table> 4618 <p class="table_footnote"> 4619 1 REQUIRED for when the height as reported by the 4620Display.getSupportedModes() method is equal or greater than the video resolution. 4621 </p> 4622 <p class="table_footnote"> 4623 2 REQUIRED for Android Television device 4624implementations. 4625 </p> 4626 <h3 id="5_3_5_h_265_(hevc)"> 4627 5.3.5. H.265 (HEVC) 4628 </h3> 4629 <p> 4630 Android device implementations, when supporting H.265 codec as described in 4631 <a href="#5_1_3_video_codecs">section 5.1.3</a>: 4632 </p> 4633 <ul> 4634 <li> 4635 MUST support the Main Profile Level 3 Main tier and the SD video decoding profiles 4636 as indicated in the following table. 4637 </li> 4638 <li> 4639 SHOULD support the HD decoding profiles as indicated in the following table. 4640 </li> 4641 <li> 4642 MUST support the HD decoding profiles as indicated in the following table 4643 if there is a hardware decoder. 4644 </li> 4645 <li> 4646 In addition, Android Television devices: 4647 </li> 4648 <li> 4649 MUST support the HD 720p decoding profile. 4650 </li> 4651 <li> 4652 STRONGLY RECOMMENDED to support the HD 1080p decoding profile. If the HD 1080p 4653 decoding profile is supported, it MUST support the Main Profile Level 4.1 Main tier. 4654 </li> 4655 <li> 4656 SHOULD support the UHD decoding profile. If the UHD decoding profile is supported the 4657 codec MUST support Main10 Level 5 Main Tier profile. 4658 </li> 4659 </ul> 4660 <table> 4661 <tr> 4662 <th> 4663 </th> 4664 <th> 4665 SD (Low quality) 4666 </th> 4667 <th> 4668 SD (High quality) 4669 </th> 4670 <th> 4671 HD 720p 4672 </th> 4673 <th> 4674 HD 1080p 4675 </th> 4676 <th> 4677 UHD 4678 </th> 4679 </tr> 4680 <tr> 4681 <th> 4682 Video resolution 4683 </th> 4684 <td> 4685 352 x 288 px 4686 </td> 4687 <td> 4688 720 x 480 px 4689 </td> 4690 <td> 4691 1280 x 720 px 4692 </td> 4693 <td> 4694 1920 x 1080 px 4695 </td> 4696 <td> 4697 3840 x 2160 px 4698 </td> 4699 </tr> 4700 <tr> 4701 <th> 4702 Video frame rate 4703 </th> 4704 <td> 4705 30 fps 4706 </td> 4707 <td> 4708 30 fps 4709 </td> 4710 <td> 4711 30 fps 4712 </td> 4713 <td> 4714 30 fps (60 fps 4715 <sup> 4716 1 4717 </sup> 4718 ) 4719 </td> 4720 <td> 4721 60 fps 4722 </td> 4723 </tr> 4724 <tr> 4725 <th> 4726 Video bitrate 4727 </th> 4728 <td> 4729 600 Kbps 4730 </td> 4731 <td> 4732 1.6 Mbps 4733 </td> 4734 <td> 4735 4 Mbps 4736 </td> 4737 <td> 4738 10 Mbps 4739 </td> 4740 <td> 4741 20 Mbps 4742 </td> 4743 </tr> 4744 </table> 4745 <p class="table_footnote"> 4746 1 REQUIRED for Android Television device 4747implementations with H.265 hardware decoding. 4748 </p> 4749 <h3 id="5_3_6_vp8"> 4750 5.3.6. VP8 4751 </h3> 4752 <p> 4753 Android device implementations, when supporting VP8 codec as described in 4754 <a href="https://source.android.com/compatibility/android-cdd.html#5_1_3_video_codecs">section 5.1.3</a>: 4755 </p> 4756 <ul> 4757 <li> 4758 MUST support the SD decoding profiles in the following table. 4759 </li> 4760 <li> 4761 SHOULD support the HD decoding profiles in the following table. 4762 </li> 4763 <li> 4764 Android Television devices MUST support the HD 1080p60 decoding profile. 4765 </li> 4766 </ul> 4767 <table> 4768 <tr> 4769 <th> 4770 </th> 4771 <th> 4772 SD (Low quality) 4773 </th> 4774 <th> 4775 SD (High quality) 4776 </th> 4777 <th> 4778 HD 720p 4779 <sup> 4780 1 4781 </sup> 4782 </th> 4783 <th> 4784 HD 1080p 4785 <sup> 4786 1 4787 </sup> 4788 </th> 4789 </tr> 4790 <tr> 4791 <th> 4792 Video resolution 4793 </th> 4794 <td> 4795 320 x 180 px 4796 </td> 4797 <td> 4798 640 x 360 px 4799 </td> 4800 <td> 4801 1280 x 720 px 4802 </td> 4803 <td> 4804 1920 x 1080 px 4805 </td> 4806 </tr> 4807 <tr> 4808 <th> 4809 Video frame rate 4810 </th> 4811 <td> 4812 30 fps 4813 </td> 4814 <td> 4815 30 fps 4816 </td> 4817 <td> 4818 30 fps (60 fps 4819 <sup> 4820 2 4821 </sup> 4822 ) 4823 </td> 4824 <td> 4825 30 (60 fps 4826 <sup> 4827 2 4828 </sup> 4829 ) 4830 </td> 4831 </tr> 4832 <tr> 4833 <th> 4834 Video bitrate 4835 </th> 4836 <td> 4837 800 Kbps 4838 </td> 4839 <td> 4840 2 Mbps 4841 </td> 4842 <td> 4843 8 Mbps 4844 </td> 4845 <td> 4846 20 Mbps 4847 </td> 4848 </tr> 4849 </table> 4850 <p class="table_footnote"> 4851 1 REQUIRED for when the height as reported by the 4852Display.getSupportedModes() method is equal or greater than the video resolution. 4853 </p> 4854 <p class="table_footnote"> 4855 2 REQUIRED for Android Television device 4856implementations. 4857 </p> 4858 <h3 id="5_3_7_vp9"> 4859 5.3.7. VP9 4860 </h3> 4861 <p> 4862 Android device implementations, when supporting VP9 codec as described in 4863 <a href="https://source.android.com/compatibility/android-cdd.html#5_1_3_video_codecs">section 5.1.3</a>: 4864 </p> 4865 <ul> 4866 <li> 4867 MUST support the SD video decoding profiles as indicated in the following table. 4868 </li> 4869 <li> 4870 SHOULD support the HD decoding profiles as indicated in the following table. 4871 </li> 4872 <li> 4873 MUST support the HD decoding profiles as indicated in the following table, 4874 if there is a hardware decoder. 4875 </li> 4876 <li> 4877 <p> 4878 In addition, Android Television devices: 4879 </p> 4880 <ul> 4881 <li> 4882 MUST support the HD 720p decoding profile. 4883 </li> 4884 <li> 4885 STRONGLY RECOMMENDED to support the HD 1080p decoding profile. 4886 </li> 4887 <li> 4888 SHOULD support the UHD decoding profile. If the UHD video decoding 4889 profile is supported, it MUST support 8-bit color depth and SHOULD 4890 support VP9 Profile 2 (10-bit). 4891 </li> 4892 </ul> 4893 </li> 4894 </ul> 4895 <table> 4896 <tr> 4897 <th> 4898 </th> 4899 <th> 4900 SD (Low quality) 4901 </th> 4902 <th> 4903 SD (High quality) 4904 </th> 4905 <th> 4906 HD 720p 4907 </th> 4908 <th> 4909 HD 1080p 4910 </th> 4911 <th> 4912 UHD 4913 </th> 4914 </tr> 4915 <tr> 4916 <th> 4917 Video resolution 4918 </th> 4919 <td> 4920 320 x 180 px 4921 </td> 4922 <td> 4923 640 x 360 px 4924 </td> 4925 <td> 4926 1280 x 720 px 4927 </td> 4928 <td> 4929 1920 x 1080 px 4930 </td> 4931 <td> 4932 3840 x 2160 px 4933 </td> 4934 </tr> 4935 <tr> 4936 <th> 4937 Video frame rate 4938 </th> 4939 <td> 4940 30 fps 4941 </td> 4942 <td> 4943 30 fps 4944 </td> 4945 <td> 4946 30 fps 4947 </td> 4948 <td> 4949 30 fps (60 fps 4950 <sup> 4951 1 4952 </sup> 4953 ) 4954 </td> 4955 <td> 4956 60 fps 4957 </td> 4958 </tr> 4959 <tr> 4960 <th> 4961 Video bitrate 4962 </th> 4963 <td> 4964 600 Kbps 4965 </td> 4966 <td> 4967 1.6 Mbps 4968 </td> 4969 <td> 4970 4 Mbps 4971 </td> 4972 <td> 4973 5 Mbps 4974 </td> 4975 <td> 4976 20 Mbps 4977 </td> 4978 </tr> 4979 </table> 4980 <p class="table_footnote"> 4981 1 REQUIRED for Android Television 4982device implementations with VP9 hardware decoding. 4983 </p> 4984 <h2 id="5_4_audio_recording"> 4985 5.4. Audio Recording 4986 </h2> 4987 <p> 4988 While some of the requirements outlined in this section are stated as SHOULD 4989since Android 4.3, the Compatibility Definition for a future version is planned 4990to change these to MUST. Existing and new Android devices are 4991 <strong> 4992 STRONGLY 4993RECOMMENDED 4994 </strong> 4995 to meet these requirements that are stated as SHOULD, or they 4996will not be able to attain Android compatibility when upgraded to the future 4997version. 4998 </p> 4999 <h3 id="5_4_1_raw_audio_capture"> 5000 5.4.1. Raw Audio Capture 5001 </h3> 5002 <p> 5003 Device implementations that declare android.hardware.microphone MUST allow 5004capture of raw audio content with the following characteristics: 5005 </p> 5006 <ul> 5007 <li> 5008 <strong> 5009 Format 5010 </strong> 5011 : Linear PCM, 16-bit 5012 </li> 5013 <li> 5014 <strong> 5015 Sampling rates 5016 </strong> 5017 : 8000, 11025, 16000, 44100 5018 </li> 5019 <li> 5020 <strong> 5021 Channels 5022 </strong> 5023 : Mono 5024 </li> 5025 </ul> 5026 <p> 5027 The capture for the above sample rates MUST be done without up-sampling, and 5028any down-sampling MUST include an appropriate anti-aliasing filter. 5029 </p> 5030 <p> 5031 Device implementations that declare android.hardware.microphone SHOULD allow 5032capture of raw audio content with the following characteristics: 5033 </p> 5034 <ul> 5035 <li> 5036 <strong> 5037 Format 5038 </strong> 5039 : Linear PCM, 16-bit 5040 </li> 5041 <li> 5042 <strong> 5043 Sampling rates 5044 </strong> 5045 : 22050, 48000 5046 </li> 5047 <li> 5048 <strong> 5049 Channels 5050 </strong> 5051 : Stereo 5052 </li> 5053 </ul> 5054 <p> 5055 If capture for the above sample rates is supported, then the capture MUST be 5056done without up-sampling at any ratio higher than 16000:22050 or 44100:48000. 5057Any up-sampling or down-sampling MUST include an appropriate anti-aliasing 5058filter. 5059 </p> 5060 <h3 id="5_4_2_capture_for_voice_recognition"> 5061 5.4.2. Capture for Voice Recognition 5062 </h3> 5063 <p> 5064 The android.media.MediaRecorder.AudioSource.VOICE_RECOGNITION audio source MUST 5065support capture at one of the sampling rates, 44100 and 48000. 5066 </p> 5067 <p> 5068 In addition to the above recording specifications, when an application has 5069started recording an audio stream using the 5070android.media.MediaRecorder.AudioSource.VOICE_RECOGNITION audio source: 5071 </p> 5072 <ul> 5073 <li> 5074 The device SHOULD exhibit approximately flat amplitude versus frequency 5075 characteristics: specifically, ±3 dB, from 100 Hz to 4000 Hz. 5076 </li> 5077 <li> 5078 Audio input sensitivity SHOULD be set such that a 90 dB sound power level 5079 (SPL) source at 1000 Hz yields RMS of 2500 for 16-bit samples. 5080 </li> 5081 <li> 5082 PCM amplitude levels SHOULD linearly track input SPL changes over at least a 5083 30 dB range from -18 dB to +12 dB re 90 dB SPL at the microphone. 5084 </li> 5085 <li> 5086 Total harmonic distortion SHOULD be less than 1% for 1 kHz at 90 dB SPL 5087 input level at the microphone. 5088 </li> 5089 <li> 5090 Noise reduction processing, if present, MUST be disabled. 5091 </li> 5092 <li> 5093 Automatic gain control, if present, MUST be disabled. 5094 </li> 5095 </ul> 5096 <p> 5097 If the platform supports noise suppression technologies tuned for speech 5098recognition, the effect MUST be controllable from the 5099android.media.audiofx.NoiseSuppressor API. Moreover, the UUID field for the 5100noise suppressor’s effect descriptor MUST uniquely identify each implementation 5101of the noise suppression technology. 5102 </p> 5103 <h3 id="5_4_3_capture_for_rerouting_of_playback"> 5104 5.4.3. Capture for Rerouting of Playback 5105 </h3> 5106 <p> 5107 The android.media.MediaRecorder.AudioSource class includes the REMOTE_SUBMIX 5108audio source. Devices that declare android.hardware.audio.output MUST properly 5109implement the REMOTE_SUBMIX audio source so that when an application uses the 5110android.media.AudioRecord API to record from this audio source, it can capture 5111a mix of all audio streams except for the following: 5112 </p> 5113 <ul> 5114 <li> 5115 STREAM_RING 5116 </li> 5117 <li> 5118 STREAM_ALARM 5119 </li> 5120 <li> 5121 STREAM_NOTIFICATION 5122 </li> 5123 </ul> 5124 <h2 id="5_5_audio_playback"> 5125 5.5. Audio Playback 5126 </h2> 5127 <p> 5128 Device implementations that declare android.hardware.audio.output MUST conform 5129to the requirements in this section. 5130 </p> 5131 <h3 id="5_5_1_raw_audio_playback"> 5132 5.5.1. Raw Audio Playback 5133 </h3> 5134 <p> 5135 The device MUST allow playback of raw audio content with the following 5136characteristics: 5137 </p> 5138 <ul> 5139 <li> 5140 <strong> 5141 Format 5142 </strong> 5143 : Linear PCM, 16-bit 5144 </li> 5145 <li> 5146 <strong> 5147 Sampling rates 5148 </strong> 5149 : 8000, 11025, 16000, 22050, 32000, 44100 5150 </li> 5151 <li> 5152 <strong> 5153 Channels 5154 </strong> 5155 : Mono, Stereo 5156 </li> 5157 </ul> 5158 <p> 5159 The device SHOULD allow playback of raw audio content with the following 5160characteristics: 5161 </p> 5162 <ul> 5163 <li> 5164 <strong> 5165 Sampling rates 5166 </strong> 5167 : 24000, 48000 5168 </li> 5169 </ul> 5170 <h3 id="5_5_2_audio_effects"> 5171 5.5.2. Audio Effects 5172 </h3> 5173 <p> 5174 Android provides an 5175 <a href="http://developer.android.com/reference/android/media/audiofx/AudioEffect.html"> 5176 API for audio effects</a> for device implementations. Device implementations that declare the feature 5177android.hardware.audio.output: 5178 </p> 5179 <ul> 5180 <li> 5181 MUST support the EFFECT_TYPE_EQUALIZER and EFFECT_TYPE_LOUDNESS_ENHANCER 5182implementations controllable through the AudioEffect subclasses Equalizer, 5183LoudnessEnhancer. 5184 </li> 5185 <li> 5186 MUST support the visualizer API implementation, controllable through the 5187Visualizer class. 5188 </li> 5189 <li> 5190 SHOULD support the EFFECT_TYPE_BASS_BOOST, EFFECT_TYPE_ENV_REVERB, 5191EFFECT_TYPE_PRESET_REVERB, and EFFECT_TYPE_VIRTUALIZER implementations 5192controllable through the AudioEffect sub-classes BassBoost, 5193EnvironmentalReverb, PresetReverb, and Virtualizer. 5194 </li> 5195 </ul> 5196 <h3 id="5_5_3_audio_output_volume"> 5197 5.5.3. Audio Output Volume 5198 </h3> 5199 <p> 5200 Android Television device implementations MUST include support for system 5201Master Volume and digital audio output volume attenuation on supported outputs, 5202except for compressed audio passthrough output (where no audio decoding is done 5203on the device). 5204 </p> 5205 <p> 5206 Android Automotive device implementations SHOULD allow adjusting audio volume 5207separately per each audio stream using the content type or usage as defined 5208by 5209 <a href="" title="http://developer.android.com/reference/android/media/AudioAttributes.html">AudioAttributes</a> and car audio usage as publicly defined in 5210 <code> 5211 android.car.CarAudioManager 5212 </code>. 5213 </p> 5214 <h2 id="5_6_audio_latency"> 5215 5.6. Audio Latency 5216 </h2> 5217 <p> 5218 Audio latency is the time delay as an audio signal passes through a system. 5219Many classes of applications rely on short latencies, to achieve real-time 5220sound effects. 5221 </p> 5222 <p> 5223 For the purposes of this section, use the following definitions: 5224 </p> 5225 <ul> 5226 <li> 5227 <strong>output latency</strong>. The interval between when an application writes a frame 5228of PCM-coded data and when the corresponding sound is presented to environment at an on-device transducer 5229or signal leaves the device via a port and can be observed externally. 5230 </li> 5231 <li> 5232 <strong>cold output latency</strong>. The output latency for the first frame, when the 5233audio output system has been idle and powered down prior to the request. 5234 </li> 5235 <li> 5236 <strong> continuous output latency</strong>. The output latency for subsequent frames, 5237after the device is playing audio. 5238 </li> 5239 <li> 5240 <strong>input latency</strong>. The interval between when a sound is presented by environment to device 5241at an on-device transducer or signal enters the device via a port 5242and when an application reads the corresponding frame of 5243PCM-coded data. 5244 </li> 5245 <li> 5246 <strong>lost input</strong>. The initial portion of an input signal that is unusable or unavailable. </li> 5247 <li> 5248 <strong>cold input latency</strong>. The sum of lost input time and the input latency 5249for the first frame, when the audio input system has been idle and powered down 5250prior to the request. 5251 </li> 5252 <li> 5253 <strong> continuous input latency</strong>. The input latency for subsequent frames, 5254while the device is capturing audio. 5255 </li> 5256 <li> 5257 <strong> cold output jitter</strong>. The variability among separate measurements of cold 5258output latency values. 5259 </li> 5260 <li> 5261 <strong> cold input jitter</strong>. The variability among separate measurements of cold 5262input latency values. 5263 </li> 5264 <li> 5265 <strong> continuous round-trip latency</strong>. The sum of continuous input latency plus 5266continuous output latency plus one buffer period. The buffer period allows 5267time for the app to process the signal and time for the app to mitigate phase difference 5268between input and output streams. 5269 </li> 5270 <li> 5271 <strong> OpenSL ES PCM buffer queue API</strong>. The set of PCM-related OpenSL ES APIs 5272within 5273 <a href="https://developer.android.com/ndk/index.html">Android NDK</a>. 5274 </li> 5275 </ul> 5276 <p> 5277 Device implementations that declare android.hardware.audio.output are STRONGLY 5278RECOMMENDED to meet or exceed these audio output requirements: 5279 </p> 5280 <ul> 5281 <li> 5282 cold output latency of 100 milliseconds or less 5283 </li> 5284 <li> 5285 continuous output latency of 45 milliseconds or less 5286 </li> 5287 <li> 5288 minimize the cold output jitter 5289 </li> 5290 </ul> 5291 <p> 5292 If a device implementation meets the requirements of this section after any 5293initial calibration when using the OpenSL ES PCM buffer queue API, for 5294continuous output latency and cold output latency over at least one supported 5295audio output device, it is STRONGLY RECOMMENDED to report support for 5296low-latency audio, by reporting the feature android.hardware.audio.low_latency 5297via the 5298 <a href="http://developer.android.com/reference/android/content/pm/PackageManager.html">android.content.pm.PackageManager</a> class. Conversely, if the device implementation does not meet these 5299requirements it MUST NOT report support for low-latency audio. 5300 </p> 5301 <p> 5302 Device implementations that include android.hardware.microphone are STRONGLY 5303RECOMMENDED to meet these input audio requirements: 5304 </p> 5305 <ul> 5306 <li> 5307 cold input latency of 100 milliseconds or less 5308 </li> 5309 <li> 5310 continuous input latency of 30 milliseconds or less 5311 </li> 5312 <li> 5313 continuous round-trip latency of 50 milliseconds or less 5314 </li> 5315 <li> 5316 minimize the cold input jitter 5317 </li> 5318 </ul> 5319 <h2 id="5_7_network_protocols"> 5320 5.7. Network Protocols 5321 </h2> 5322 <p> 5323 Devices MUST support the 5324 <a href="http://developer.android.com/guide/appendix/media-formats.html"> media network protocols</a> for 5325audio and video playback as specified in the Android SDK documentation. 5326Specifically, devices MUST support the following media network protocols: 5327 </p> 5328 <ul> 5329 <li> 5330 <p> 5331 HTTP(S) progressive streaming 5332 <br/> 5333 All required codecs and container formats in 5334 <a href="#5_1_media_codecs">section 5.1</a> MUST 5335 be supported over HTTP(S) 5336 </p> 5337 </li> 5338 <li> 5339 <p> 5340 <a href="http://tools.ietf.org/html/draft-pantos-http-live-streaming-07">HTTP Live Streaming draft protocol, Version 7</a> <br/> 5341 The following media segment formats MUST be supported: 5342 </p> 5343 </li> 5344 </ul> 5345 <table> 5346 <tr> 5347 <th> 5348 Segment formats 5349 </th> 5350 <th> 5351 Reference(s) 5352 </th> 5353 <th> 5354 Required codec support 5355 </th> 5356 </tr> 5357 <tr id="mp2t"> 5358 <td> 5359 MPEG-2 Transport Stream 5360 </td> 5361 <td> 5362 <a href="http://www.iso.org/iso/catalogue_detail?csnumber=44169">ISO 13818</a> </td> 5363 <td> 5364 Video codecs: 5365 <ul> 5366 <li class="table_list"> 5367 H264 AVC 5368 </li> 5369 <li class="table_list"> 5370 MPEG-4 SP 5371 </li> 5372 <li class="table_list"> 5373 MPEG-2 5374 </li> 5375 </ul> 5376 See 5377 <a href="#5_1_3_video_codecs">section 5.1.3</a> for details on H264 AVC, MPEG2-4 SP, 5378 <br/> 5379 and MPEG-2. 5380 <p> 5381 Audio codecs: 5382 </p> 5383 <ul> 5384 <li class="table_list"> 5385 AAC 5386 </li> 5387 </ul> 5388 See 5389 <a href="#5_1_1_audio_codecs">section 5.1.1</a> for details on AAC and its variants. 5390 </td> 5391 </tr> 5392 <tr> 5393 <td> 5394 AAC with ADTS framing and ID3 tags 5395 </td> 5396 <td> 5397 <a href="http://www.iso.org/iso/home/store/catalogue_tc/catalogue_detail.htm?csnumber=43345">ISO 13818-7</a> </td> 5398 <td> 5399 See 5400 <a href="#5_1_1_audio_codecs">section 5.1.1</a> for details on AAC and its variants 5401 </td> 5402 </tr> 5403 <tr> 5404 <td> 5405 WebVTT 5406 </td> 5407 <td> 5408 <a href="http://dev.w3.org/html5/webvtt/">WebVTT</a> </td> 5409 <td> 5410 </td> 5411 </tr> 5412 </table> 5413 <ul> 5414 <li> 5415 <p> 5416 RTSP (RTP, SDP) 5417 </p> 5418 <p> 5419 The following RTP audio video profile and related codecs MUST be supported. 5420For exceptions please see the table footnotes in 5421 <a href="#5_1_media_codecs">section 5.1</a>. 5422 </p> 5423 </li> 5424 </ul> 5425 <table> 5426 <tr> 5427 <th> 5428 Profile name 5429 </th> 5430 <th> 5431 Reference(s) 5432 </th> 5433 <th> 5434 Required codec support 5435 </th> 5436 </tr> 5437 <tr> 5438 <td> 5439 H264 AVC 5440 </td> 5441 <td> 5442 <a href="https://tools.ietf.org/html/rfc6184">RFC 6184</a> </td> 5443 <td> 5444 See 5445 <a href="#5_1_3_video_codecs">section 5.1.3</a> for details on H264 AVC 5446 </td> 5447 </tr> 5448 <tr> 5449 <td> 5450 MP4A-LATM 5451 </td> 5452 <td> 5453 <a href="https://tools.ietf.org/html/rfc6416">RFC 6416</a> </td> 5454 <td> 5455 See 5456 <a href="#5_1_1_audio_codecs">section 5.1.1</a> for details on AAC and its variants 5457 </td> 5458 </tr> 5459 <tr> 5460 <td> 5461 H263-1998 5462 </td> 5463 <td> 5464 <a href="https://tools.ietf.org/html/rfc3551">RFC 3551</a> <br/> 5465 <a href="https://tools.ietf.org/html/rfc4629">RFC 4629</a> <br/> 5466 <a href="https://tools.ietf.org/html/rfc2190">RFC 2190</a> </td> 5467 <td> 5468 See 5469 <a href="#5_1_3_video_codecs">section 5.1.3</a> for details on H263 5470 </td> 5471 </tr> 5472 <tr> 5473 <td> 5474 H263-2000 5475 </td> 5476 <td> 5477 <a href="https://tools.ietf.org/html/rfc4629">RFC 4629</a> </td> 5478 <td> 5479 See 5480 <a href="#5_1_3_video_codecs">section 5.1.3</a> for details on H263 5481 </td> 5482 </tr> 5483 <tr> 5484 <td> 5485 AMR 5486 </td> 5487 <td> 5488 <a href="https://tools.ietf.org/html/rfc4867">RFC 4867</a> </td> 5489 <td> 5490 See 5491 <a href="#5_1_1_audio_codecs">section 5.1.1</a> for details on AMR-NB 5492 </td> 5493 </tr> 5494 <tr> 5495 <td> 5496 AMR-WB 5497 </td> 5498 <td> 5499 <a href="https://tools.ietf.org/html/rfc4867">RFC 4867</a> </td> 5500 <td> 5501 See 5502 <a href="#5_1_1_audio_codecs">section 5.1.1</a> for details on AMR-WB 5503 </td> 5504 </tr> 5505 <tr> 5506 <td> 5507 MP4V-ES 5508 </td> 5509 <td> 5510 <a href="https://tools.ietf.org/html/rfc6416">RFC 6416</a> </td> 5511 <td> 5512 See 5513 <a href="#5_1_3_video_codecs">section 5.1.3</a> for details on MPEG-4 SP 5514 </td> 5515 </tr> 5516 <tr> 5517 <td> 5518 mpeg4-generic 5519 </td> 5520 <td> 5521 <a href="https://tools.ietf.org/html/rfc3640">RFC 3640</a> </td> 5522 <td> 5523 See 5524 <a href="#5_1_1_audio_codecs">section 5.1.1</a> for details on AAC and its variants 5525 </td> 5526 </tr> 5527 <tr> 5528 <td> 5529 MP2T 5530 </td> 5531 <td> 5532 <a href="https://tools.ietf.org/html/rfc2250">RFC 2250</a> </td> 5533 <td> 5534 See 5535 <a href="#mp2t">MPEG-2 Transport Stream</a> underneath HTTP Live Streaming for details 5536 </td> 5537 </tr> 5538 </table> 5539 <h2 id="5_8_secure_media"> 5540 5.8. Secure Media 5541 </h2> 5542 <p> 5543 Device implementations that support secure video output and are capable of 5544supporting secure surfaces MUST declare support for Display.FLAG_SECURE. Device 5545implementations that declare support for Display.FLAG_SECURE, if they support a 5546wireless display protocol, MUST secure the link with a cryptographically strong 5547mechanism such as HDCP 2.x or higher for Miracast wireless displays. Similarly 5548if they support a wired external display, the device implementations MUST 5549support HDCP 1.2 or higher. Android Television device implementations MUST 5550support HDCP 2.2 for devices supporting 4K resolution and HDCP 1.4 or above for 5551lower resolutions. The upstream Android open source implementation includes 5552support for wireless (Miracast) and wired (HDMI) displays that satisfies this 5553requirement. 5554 </p> 5555 <h2 id="5_9_musical_instrument_digital_interface_(midi)"> 5556 5.9. Musical Instrument Digital Interface (MIDI) 5557 </h2> 5558 <p> 5559 If a device implementation supports the inter-app MIDI software transport 5560(virtual MIDI devices), and it supports MIDI over 5561 <em> 5562 all 5563 </em> 5564 of the following 5565MIDI-capable hardware transports for which it provides generic non-MIDI 5566connectivity, it is STRONGLY RECOMMENDED to report support for feature 5567android.software.midi via the 5568 <a href="http://developer.android.com/reference/android/content/pm/PackageManager.html">android.content.pm.PackageManager</a> class. 5569 </p> 5570 <p> 5571 The MIDI-capable hardware transports are: 5572 </p> 5573 <ul> 5574 <li> 5575 USB host mode (section 7.7 USB) 5576 </li> 5577 <li> 5578 USB peripheral mode (section 7.7 USB) 5579 </li> 5580 <li> 5581 MIDI over Bluetooth LE acting in central role (section 7.4.3 Bluetooth) 5582 </li> 5583 </ul> 5584 <p> 5585 Conversely, if the device implementation provides generic non-MIDI connectivity 5586over a particular MIDI-capable hardware transport listed above, but does not 5587support MIDI over that hardware transport, it MUST NOT report support for 5588feature android.software.midi. 5589 </p> 5590 <h2 id="5_10_professional_audio"> 5591 5.10. Professional Audio 5592 </h2> 5593 <p> 5594 If a device implementation meets 5595 <em> 5596 all 5597 </em> 5598 of the following requirements, it is 5599STRONGLY RECOMMENDED to report support for feature android.hardware.audio.pro 5600via the 5601 <a href="http://developer.android.com/reference/android/content/pm/PackageManager.html">android.content.pm.PackageManager</a> class. 5602 </p> 5603 <ul> 5604 <li> 5605 The device implementation MUST report support for feature 5606android.hardware.audio.low_latency. 5607 </li> 5608 <li> 5609 The continuous round-trip audio latency, as defined in section 5.6 Audio 5610Latency, MUST be 20 milliseconds or less and SHOULD be 10 milliseconds or less 5611over at least one supported path. 5612 </li> 5613 <li> 5614 If the device includes a 4 conductor 3.5mm audio jack, the continuous 5615round-trip audio latency MUST be 20 milliseconds or less over the audio jack 5616path, and SHOULD be 10 milliseconds or less over at the audio jack path. 5617 </li> 5618 <li> 5619 The device implementation MUST include a USB port(s) supporting USB host 5620mode and USB peripheral mode. 5621 </li> 5622 <li> 5623 The USB host mode MUST implement the USB audio class. 5624 </li> 5625 <li> 5626 If the device includes an HDMI port, the device implementation MUST support 5627output in stereo and eight channels at 20-bit or 24-bit depth and 192 kHz 5628without bit-depth loss or resampling. 5629 </li> 5630 <li> 5631 The device implementation MUST report support for feature 5632android.software.midi. 5633 </li> 5634 <li> 5635 If the device includes a 4 conductor 3.5mm audio jack, the device 5636implementation is STRONGLY RECOMMENDED to comply with section 5637 <a href="https://source.android.com/accessories/headset/specification.html#mobile_device_jack_specifications"> 5638 Mobile device (jack) specifications</a> of the 5639 <a href="https://source.android.com/accessories/headset/specification.html">Wired Audio Headset Specification (v1.1)</a>. 5640 </li> 5641 </ul> 5642 <p> 5643 Latencies and USB audio requirements MUST be met using the 5644 <a href="https://developer.android.com/ndk/guides/audio/opensl-for-android.html">OpenSL ES</a> PCM buffer queue API. 5645 </p> 5646 <p> 5647 In addition, a device implementation that reports support for this feature SHOULD: 5648 </p> 5649 <ul> 5650 <li> 5651 Provide a sustainable level of CPU performance while audio is active. 5652 </li> 5653 <li> 5654 Minimize audio clock inaccuracy and drift relative to standard time. 5655 </li> 5656 <li> 5657 Minimize audio clock drift relative to the CPU 5658 <code> 5659 CLOCK_MONOTONIC 5660 </code> 5661 when both are active. 5662 </li> 5663 <li> 5664 Minimize audio latency over on-device transducers. 5665 </li> 5666 <li> 5667 Minimize audio latency over USB digital audio. 5668 </li> 5669 <li> 5670 Document audio latency measurements over all paths. 5671 </li> 5672 <li> 5673 Minimize jitter in audio buffer completion callback entry times, as this affects usable percentage of full CPU bandwidth by the callback. 5674 </li> 5675 <li> 5676 Provide zero audio underruns (output) or overruns (input) under normal use at reported latency. 5677 </li> 5678 <li> 5679 Provide zero inter-channel latency difference. 5680 </li> 5681 <li> 5682 Minimize MIDI mean latency over all transports. 5683 </li> 5684 <li> 5685 Minimize MIDI latency variability under load (jitter) over all transports. 5686 </li> 5687 <li> 5688 Provide accurate MIDI timestamps over all transports. 5689 </li> 5690 <li> 5691 Minimize audio signal noise over on-device transducers, including the period immediately after cold start. 5692 </li> 5693 <li> 5694 Provide zero audio clock difference between the input and output sides of corresponding 5695 end-points, when both are active. Examples of corresponding end-points include 5696 the on-device microphone and speaker, or the audio jack input and output. 5697 </li> 5698 <li> 5699 Handle audio buffer completion callbacks for the input and output sides of corresponding 5700 end-points on the same thread when both are active, and enter the output callback immediately 5701 after the return from the input callback. Or if it is not feasible to handle the callbacks 5702 on the same thread, then enter the output callback shortly after entering the input callback 5703 to permit the application to have a consistent timing of the input and output sides. 5704 </li> 5705 <li> 5706 Minimize the phase difference between HAL audio buffering for the input and output 5707 sides of corresponding end-points. 5708 </li> 5709 <li> 5710 Minimize touch latency. 5711 </li> 5712 <li> 5713 Minimize touch latency variability under load (jitter). 5714 </li> 5715 </ul> 5716 <h2 id="5_11_capture_for_unprocessed"> 5717 5.11. Capture for Unprocessed 5718 </h2> 5719 <p> 5720 Starting from Android 7.0, 5721a new recording source has been added. It can be accessed using 5722the 5723 <code> 5724 android.media.MediaRecorder.AudioSource.UNPROCESSED 5725 </code> 5726 audio 5727source. In OpenSL ES, it can be accessed with the record preset 5728 <code> 5729 SL_ANDROID_RECORDING_PRESET_UNPROCESSED 5730 </code>. 5731 </p> 5732 <p> 5733 A device MUST satisfy all of the following requirements to report support 5734of the unprocessed audio source via the 5735 <code> 5736 android.media.AudioManager 5737 </code> 5738 property 5739 <a href="http://developer.android.com/reference/android/media/AudioManager.html#PROPERTY_SUPPORT_AUDIO_SOURCE_UNPROCESSED">PROPERTY_SUPPORT_AUDIO_SOURCE_UNPROCESSED</a>: 5740 </p> 5741 <ul> 5742 <li> 5743 <p> 5744 The device MUST exhibit approximately flat amplitude-versus-frequency 5745characteristics in the mid-frequency range: specifically ±10dB from 5746100 Hz to 7000 Hz. 5747 </p> 5748 </li> 5749 <li> 5750 <p> 5751 The device MUST exhibit amplitude levels in the low frequency range: 5752specifically from ±20 dB from 5 Hz to 100 Hz compared to the mid-frequency range. 5753 </p> 5754 </li> 5755 <li> 5756 <p> 5757 The device MUST exhibit amplitude levels in the high frequency range: 5758specifically from ±30 dB from 4000 Hz to 22 KHz compared to the mid-frequency range. 5759 </p> 5760 </li> 5761 <li> 5762 <p> 5763 Audio input sensitivity MUST be set such that a 1000 Hz sinusoidal tone 5764source played at 94 dB Sound Pressure Level (SPL) 5765yields a response with RMS of 520 for 16 5766bit-samples (or -36 dB Full Scale for floating point/double precision 5767samples). 5768 </p> 5769 </li> 5770 <li> 5771 <p> 5772 SNR > 60 dB (difference between 94 dB SPL and equivalent SPL of self 5773noise, A-weighted). 5774 </p> 5775 </li> 5776 <li> 5777 <p> 5778 Total harmonic distortion MUST be less than 1% for 1 kHZ at 90 dB SPL 5779input level at the microphone. 5780 </p> 5781 </li> 5782 <li> 5783 <p> 5784 The only signal processing allowed in the path is a level multiplier 5785to bring the level to desired range. This level multiplier MUST NOT 5786introduce delay or latency to the signal path. 5787 </p> 5788 </li> 5789 <li> 5790 <p> 5791 No other signal processing is allowed in the path, such as Automatic Gain 5792Control, High Pass Filter, or Echo Cancellation. If any signal processing 5793is present in the architecture for any reason, it MUST be disabled and 5794effectively introduce zero delay or extra latency to the signal path. 5795 </p> 5796 </li> 5797 </ul> 5798 <p> 5799 All SPL measurements are made directly next to the microphone under test. 5800 </p> 5801 <p> 5802 For multiple microphone configurations, these requirements apply to each 5803microphone. 5804 </p> 5805 <p> 5806 It is STRONGLY RECOMMENDED that a device satisfy as many of the requirements for the signal 5807path for the unprocessed recording source; however, a device must satisfy 5808 <em> 5809 all 5810 </em> 5811 of these 5812requirements, listed above, if it claims to support the unprocessed audio source. 5813 </p> 5814 <h1 id="6_developer_tools_and_options_compatibility"> 5815 6. Developer Tools and Options Compatibility 5816 </h1> 5817 <h2 id="6_1_developer_tools"> 5818 6.1. Developer Tools 5819 </h2> 5820 <p> 5821 Device implementations MUST support the Android Developer Tools provided in the 5822Android SDK. Android compatible devices MUST be compatible with: 5823 </p> 5824 <ul> 5825 <li> 5826 <a href="http://developer.android.com/tools/help/adb.html"> 5827 <strong> 5828 Android Debug Bridge (adb) 5829 </strong> 5830 </a> 5831 <ul> 5832 <li> 5833 Device implementations MUST support all adb functions as documented in 5834the Android SDK including 5835 <a href="https://source.android.com/devices/input/diagnostics.html">dumpsys</a>. 5836 </li> 5837 <li> 5838 The device-side adb daemon MUST be inactive by default and there MUST 5839be a user-accessible mechanism to turn on the Android Debug Bridge. If a device 5840implementation omits USB peripheral mode, it MUST implement the Android Debug 5841Bridge via local-area network (such as Ethernet or 802.11). 5842 </li> 5843 <li> 5844 Android includes support for secure adb. Secure adb enables adb on 5845known authenticated hosts. Device implementations MUST support secure adb. 5846 </li> 5847 </ul> 5848 </li> 5849 <li> 5850 <a href="http://developer.android.com/tools/debugging/ddms.html"> 5851 <strong> 5852 Dalvik Debug Monitor Service (ddms) 5853 </strong> 5854 </a> 5855 <ul> 5856 <li> 5857 Device implementations MUST support all ddms features as documented in the Android SDK. 5858 </li> 5859 <li> 5860 As ddms uses adb, support for ddms SHOULD be inactive by default, but MUST be supported whenever the user has activated the Android Debug Bridge, as above. 5861 </li> 5862 </ul> 5863 </li> 5864 <li> 5865 <a href="http://developer.android.com/tools/help/monkey.html"> 5866 <strong> 5867 Monkey 5868 </strong> 5869 </a> 5870 . Device 5871implementations MUST include the Monkey framework, and make it available for 5872applications to use. 5873 </li> 5874 <li> 5875 <a href="http://developer.android.com/tools/help/systrace.html"> 5876 <strong> 5877 SysTrace 5878 </strong> 5879 </a> 5880 <ul> 5881 <li> 5882 Device implementations MUST support systrace tool as documented in the 5883Android SDK. Systrace must be inactive by default, and there MUST be a 5884user-accessible mechanism to turn on Systrace. 5885 </li> 5886 <li> 5887 Most Linux-based systems and Apple Macintosh systems recognize Android 5888devices using the standard Android SDK tools, without additional support; 5889however Microsoft Windows systems typically require a driver for new Android 5890devices. (For instance, new vendor IDs and sometimes new device IDs require 5891custom USB drivers for Windows systems.) 5892 </li> 5893 <li> 5894 If a device implementation is unrecognized by the adb tool as provided 5895in the standard Android SDK, device implementers MUST provide Windows drivers 5896allowing developers to connect to the device using the adb protocol. These 5897drivers MUST be provided for Windows XP, Windows Vista, Windows 7, Windows 8, 5898and Windows 10 in both 32-bit and 64-bit versions. 5899 </li> 5900 </ul> 5901 </li> 5902 </ul> 5903 <h2 id="6_2_developer_options"> 5904 6.2. Developer Options 5905 </h2> 5906 <p> 5907 Android includes support for developers to configure application 5908development-related settings. Device implementations MUST honor the 5909 <a href="http://developer.android.com/reference/android/provider/Settings.html#ACTION_APPLICATION_DEVELOPMENT_SETTINGS">android.settings.APPLICATION_DEVELOPMENT_SETTINGS</a> intent to show application development-related settings The upstream Android 5910implementation hides the Developer Options menu by default and enables users to 5911launch Developer Options after pressing seven (7) times on the 5912 <strong> 5913 Settings 5914 </strong> 5915 > 5916 <strong> 5917 About Device 5918 </strong> 5919 > 5920 <strong> 5921 Build Number 5922 </strong> 5923 menu item. Device implementations MUST 5924provide a consistent experience for Developer Options. Specifically, device 5925implementations MUST hide Developer Options by default and MUST provide a 5926mechanism to enable Developer Options that is consistent with the upstream 5927Android implementation. 5928 </p> 5929 <div class="note"> 5930 Android Automotive implementations MAY limit access to the Developer Options 5931menu by visually hiding or disabling the menu when the vehicle is in motion. 5932 </div> 5933 <h1 id="7_hardware_compatibility"> 5934 7. Hardware Compatibility 5935 </h1> 5936 <p> 5937 If a device includes a particular hardware component that has a corresponding 5938API for third-party developers, the device implementation MUST implement that 5939API as described in the Android SDK documentation. If an API in the SDK 5940interacts with a hardware component that is stated to be optional and the 5941device implementation does not possess that component: 5942 </p> 5943 <ul> 5944 <li> 5945 Complete class definitions (as documented by the SDK) for the component 5946APIs MUST still be presented. 5947 </li> 5948 <li> 5949 The API’s behaviors MUST be implemented as no-ops in some reasonable 5950fashion. 5951 </li> 5952 <li> 5953 API methods MUST return null values where permitted by the SDK 5954documentation. 5955 </li> 5956 <li> 5957 API methods MUST return no-op implementations of classes where null values 5958are not permitted by the SDK documentation. 5959 </li> 5960 <li> 5961 API methods MUST NOT throw exceptions not documented by the SDK 5962documentation. 5963 </li> 5964 </ul> 5965 <p> 5966 A typical example of a scenario where these requirements apply is the telephony 5967API: Even on non-phone devices, these APIs must be implemented as reasonable 5968no-ops. 5969 </p> 5970 <p> 5971 Device implementations MUST consistently report accurate hardware configuration 5972information via the getSystemAvailableFeatures() and hasSystemFeature(String) 5973methods on the 5974 <a href="http://developer.android.com/reference/android/content/pm/PackageManager.html">android.content.pm.PackageManager</a> class for the same build fingerprint. 5975 </p> 5976 <h2 id="7_1_display_and_graphics"> 5977 7.1. Display and Graphics 5978 </h2> 5979 <p> 5980 Android includes facilities that automatically adjust application assets and UI 5981layouts appropriately for the device to ensure that third-party applications 5982run well on a 5983 <a href="http://developer.android.com/guide/practices/screens_support.html"> 5984 variety of hardware configurations</a>. 5985Devices MUST properly implement these APIs and behaviors, as detailed in this 5986section. 5987 </p> 5988 <p> 5989 The units referenced by the requirements in this section are defined as follows: 5990 </p> 5991 <ul> 5992 <li> 5993 <strong> 5994 physical diagonal size 5995 </strong> 5996 . The distance in inches between two opposing 5997corners of the illuminated portion of the display. 5998 </li> 5999 <li> 6000 <strong> 6001 dots per inch (dpi) 6002 </strong> 6003 . The number of pixels encompassed by a linear 6004horizontal or vertical span of 1”. Where dpi values are listed, both horizontal 6005and vertical dpi must fall within the range. 6006 </li> 6007 <li> 6008 <strong> 6009 aspect ratio 6010 </strong> 6011 . The ratio of the pixels of the longer dimension to the 6012shorter dimension of the screen. For example, a display of 480x854 pixels would 6013be 854/480 = 1.779, or roughly “16:9”. 6014 </li> 6015 <li> 6016 <strong> 6017 density-independent pixel (dp) 6018 </strong> 6019 . The virtual pixel unit normalized to a 6020160 dpi screen, calculated as: pixels = dps * (density/160). 6021 </li> 6022 </ul> 6023 <h3 id="7_1_1_screen_configuration"> 6024 7.1.1. Screen Configuration 6025 </h3> 6026 <h4 id="7_1_1_1_screen_size"> 6027 7.1.1.1. Screen Size 6028 </h4> 6029 <div class="note"> 6030 Android Watch devices (detailed in 6031 <a href="#2_device_types">section 2</a> ) MAY have 6032smaller screen sizes as described in this section. 6033 </div> 6034 <p> 6035 The Android UI framework supports a variety of different screen sizes, and 6036allows applications to query the device screen size (aka “screen layout") via 6037android.content.res.Configuration.screenLayout with the SCREENLAYOUT_SIZE_MASK. 6038Device implementations MUST report the correct 6039 <a href="http://developer.android.com/guide/practices/screens_support.html"> 6040 screen size</a> as 6041defined in the Android SDK documentation and determined by the upstream Android 6042platform. Specifically, device implementations MUST report the correct screen 6043size according to the following logical density-independent pixel (dp) screen 6044dimensions. 6045 </p> 6046 <ul> 6047 <li> 6048 Devices MUST have screen sizes of at least 426 dp x 320 dp (‘small’), 6049unless it is an Android Watch device. 6050 </li> 6051 <li> 6052 Devices that report screen size ‘normal’ MUST have screen sizes of at least 6053480 dp x 320 dp. 6054 </li> 6055 <li> 6056 Devices that report screen size ‘large’ MUST have screen sizes of at least 6057640 dp x 480 dp. 6058 </li> 6059 <li> 6060 Devices that report screen size ‘xlarge’ MUST have screen sizes of at least 6061960 dp x 720 dp. 6062 </li> 6063 </ul> 6064 <p> 6065 In addition: 6066 </p> 6067 <ul> 6068 <li> 6069 Android Watch devices MUST have a screen with the physical diagonal size in 6070the range from 1.1 to 2.5 inches. 6071 </li> 6072 <li> 6073 Android Automotive devices MUST have a screen with the physical diagonal 6074size greater than or equal to 6 inches. 6075 </li> 6076 <li> 6077 Android Automotive devices MUST have a screen size of at least 750 dp x 6078480 dp. 6079 </li> 6080 <li> 6081 Other types of Android device implementations, with a physically integrated 6082screen, MUST have a screen at least 2.5 inches in physical diagonal size. 6083 </li> 6084 </ul> 6085 <p> 6086 Devices MUST NOT change their reported screen size at any time. 6087 </p> 6088 <p> 6089 Applications optionally indicate which screen sizes they support via the 6090<supports-screens> attribute in the AndroidManifest.xml file. Device 6091implementations MUST correctly honor applications' stated support for small, 6092normal, large, and xlarge screens, as described in the Android SDK 6093documentation. 6094 </p> 6095 <h4 id="7_1_1_2_screen_aspect_ratio"> 6096 7.1.1.2. Screen Aspect Ratio 6097 </h4> 6098 <div class="note"> 6099 Android Watch devices MAY have an aspect ratio of 1.0 (1:1). 6100 </div> 6101 <p> 6102 The screen aspect ratio MUST be a value from 1.3333 (4:3) to 1.86 (roughly 610316:9), but Android Watch devices MAY have an aspect ratio of 1.0 (1:1) because 6104such a device implementation will use a UI_MODE_TYPE_WATCH as the 6105android.content.res.Configuration.uiMode. 6106 </p> 6107 <h4 id="7_1_1_3_screen_density"> 6108 7.1.1.3. Screen Density 6109 </h4> 6110 <p> 6111 The Android UI framework defines a set of standard logical densities to help 6112application developers target application resources. Device implementations 6113MUST report only one of the following logical Android framework densities 6114through the android.util.DisplayMetrics APIs, and MUST execute applications at 6115this standard density and MUST NOT change the value at at any time for the 6116default display. 6117 </p> 6118 <ul> 6119 <li> 6120 120 dpi (ldpi) 6121 </li> 6122 <li> 6123 160 dpi (mdpi) 6124 </li> 6125 <li> 6126 213 dpi (tvdpi) 6127 </li> 6128 <li> 6129 240 dpi (hdpi) 6130 </li> 6131 <li> 6132 280 dpi (280dpi) 6133 </li> 6134 <li> 6135 320 dpi (xhdpi) 6136 </li> 6137 <li> 6138 360 dpi (360dpi) 6139 </li> 6140 <li> 6141 400 dpi (400dpi) 6142 </li> 6143 <li> 6144 420 dpi (420dpi) 6145 </li> 6146 <li> 6147 480 dpi (xxhdpi) 6148 </li> 6149 <li> 6150 560 dpi (560dpi) 6151 </li> 6152 <li> 6153 640 dpi (xxxhdpi) 6154 </li> 6155 </ul> 6156 <p> 6157 Device implementations SHOULD define the standard Android framework density 6158that is numerically closest to the physical density of the screen, unless that 6159logical density pushes the reported screen size below the minimum supported. If 6160the standard Android framework density that is numerically closest to the 6161physical density results in a screen size that is smaller than the smallest 6162supported compatible screen size (320 dp width), device implementations SHOULD 6163report the next lowest standard Android framework density. 6164 </p> 6165 <p> 6166 Device implementations are STRONGLY RECOMMENDED to provide users a setting to change 6167the display size. If there is an implementation to change the display size of the device, 6168it MUST align with the AOSP implementation as indicated below: 6169 </p> 6170 <ul> 6171 <li> 6172 The display size MUST NOT be scaled any larger than 1.5 times the native density or 6173 produce an effective minimum screen dimension smaller than 320dp (equivalent 6174 to resource qualifier sw320dp), whichever comes first. 6175 </li> 6176 <li> 6177 Display size MUST NOT be scaled any smaller than 0.85 times the native density. 6178 </li> 6179 <li> 6180 To ensure good usability and consistent font sizes, it is RECOMMENDED that the 6181 following scaling of Native Display options be provided (while complying with the limits 6182 specified above) 6183 </li> 6184 <li> 6185 Small: 0.85x 6186 </li> 6187 <li> 6188 Default: 1x (Native display scale) 6189 </li> 6190 <li> 6191 Large: 1.15x 6192 </li> 6193 <li> 6194 Larger: 1.3x 6195 </li> 6196 <li> 6197 Largest 1.45x 6198 </li> 6199 </ul> 6200 <h3 id="7_1_2_display_metrics"> 6201 7.1.2. Display Metrics 6202 </h3> 6203 <p> 6204 Device implementations MUST report correct values for all display metrics 6205defined in 6206 <a href="http://developer.android.com/reference/android/util/DisplayMetrics.html">android.util.DisplayMetrics</a> and MUST report the same values regardless of whether the embedded or external 6207screen is used as the default display. 6208 </p> 6209 <h3 id="7_1_3_screen_orientation"> 6210 7.1.3. Screen Orientation 6211 </h3> 6212 <p> 6213 Devices MUST report which screen orientations they support 6214(android.hardware.screen.portrait and/or android.hardware.screen.landscape) and 6215MUST report at least one supported orientation. For example, a device with a 6216fixed orientation landscape screen, such as a television or laptop, SHOULD only 6217report android.hardware.screen.landscape. 6218 </p> 6219 <p> 6220 Devices that report both screen orientations MUST support dynamic orientation 6221by applications to either portrait or landscape screen orientation. That is, 6222the device must respect the application’s request for a specific screen 6223orientation. Device implementations MAY select either portrait or landscape 6224orientation as the default. 6225 </p> 6226 <p> 6227 Devices MUST report the correct value for the device’s current orientation, 6228whenever queried via the android.content.res.Configuration.orientation, 6229android.view.Display.getOrientation(), or other APIs. 6230 </p> 6231 <p> 6232 Devices MUST NOT change the reported screen size or density when changing orientation. 6233 </p> 6234 <h3 id="7_1_4_2d_and_3d_graphics_acceleration"> 6235 7.1.4. 2D and 3D Graphics Acceleration 6236 </h3> 6237 <p> 6238 Device implementations MUST support both OpenGL ES 1.0 and 2.0, as embodied and 6239detailed in the Android SDK documentations. Device implementations SHOULD 6240support OpenGL ES 3.0, 3.1, or 3.2 on devices capable of supporting it. Device 6241implementations MUST also support 6242 <a href="http://developer.android.com/guide/topics/renderscript/"> 6243 Android RenderScript</a>, as detailed in the Android SDK documentation. 6244 </p> 6245 <p> 6246 Device implementations MUST also correctly identify themselves as supporting 6247OpenGL ES 1.0, OpenGL ES 2.0, OpenGL ES 3.0, OpenGL 3.1, or OpenGL 3.2. That is: 6248 </p> 6249 <ul> 6250 <li> 6251 The managed APIs (such as via the GLES10.getString() method) MUST report 6252support for OpenGL ES 1.0 and OpenGL ES 2.0. 6253 </li> 6254 <li> 6255 The native C/C++ OpenGL APIs (APIs available to apps via libGLES_v1CM.so, 6256libGLES_v2.so, or libEGL.so) MUST report support for OpenGL ES 1.0 and OpenGL 6257ES 2.0. 6258 </li> 6259 <li> 6260 Device implementations that declare support for OpenGL ES 3.0, 3.1, or 3.2 MUST 6261support the corresponding managed APIs and include support for native C/C++ 6262APIs. On device implementations that declare support for OpenGL ES 3.0, 3.1, or 62633.2 libGLESv2.so MUST export the corresponding function symbols in addition to 6264the OpenGL ES 2.0 function symbols. 6265 </li> 6266 </ul> 6267 <p> 6268 Android provides an OpenGL ES 6269 <a href="https://developer.android.com/reference/android/opengl/GLES31Ext.html">extension pack</a> with Java interfaces and native support for advanced graphics functionality 6270such as tessellation and the ASTC texture compression format. Android device 6271implementations MUST support the extension pack if the device supports OpenGL 6272ES 3.2 and MAY support it otherwise. If the extension pack is supported in its 6273entirety, the device MUST identify the support through the 6274 <code> 6275 android.hardware.opengles.aep 6276 </code> 6277 feature flag. 6278 </p> 6279 <p> 6280 Also, device implementations MAY implement any desired OpenGL ES extensions. 6281However, device implementations MUST report via the OpenGL ES managed and 6282native APIs all extension strings that they do support, and conversely MUST NOT 6283report extension strings that they do not support. 6284 </p> 6285 <p> 6286 Note that Android includes support for applications to optionally specify that 6287they require specific OpenGL texture compression formats. These formats are 6288typically vendor-specific. Device implementations are not required by Android 6289to implement any specific texture compression format. However, they SHOULD 6290accurately report any texture compression formats that they do support, via the 6291getString() method in the OpenGL API. 6292 </p> 6293 <p> 6294 Android includes a mechanism for applications to declare that they want to 6295enable hardware acceleration for 2D graphics at the Application, Activity, 6296Window, or View level through the use of a manifest tag 6297 <a href="http://developer.android.com/guide/topics/graphics/hardware-accel.html">android:hardwareAccelerated</a> or direct API calls. 6298 </p> 6299 <p> 6300 Device implementations MUST enable hardware acceleration by default, and MUST 6301disable hardware acceleration if the developer so requests by setting 6302android:hardwareAccelerated="false” or disabling hardware acceleration directly 6303through the Android View APIs. 6304 </p> 6305 <p> 6306 In addition, device implementations MUST exhibit behavior consistent with the 6307Android SDK documentation on 6308 <a href="http://developer.android.com/guide/topics/graphics/hardware-accel.html"> 6309 hardware acceleration</a>. 6310 </p> 6311 <p> 6312 Android includes a TextureView object that lets developers directly integrate 6313hardware-accelerated OpenGL ES textures as rendering targets in a UI hierarchy. 6314Device implementations MUST support the TextureView API, and MUST exhibit 6315consistent behavior with the upstream Android implementation. 6316 </p> 6317 <p> 6318 Android includes support for EGL_ANDROID_RECORDABLE, an EGLConfig attribute 6319that indicates whether the EGLConfig supports rendering to an ANativeWindow 6320that records images to a video. Device implementations MUST support 6321 <a href="https://www.khronos.org/registry/egl/extensions/ANDROID/EGL_ANDROID_recordable.txt">EGL_ANDROID_RECORDABLE</a> extension. 6322 </p> 6323 <h3 id="7_1_5_legacy_application_compatibility_mode"> 6324 7.1.5. Legacy Application Compatibility Mode 6325 </h3> 6326 <p> 6327 Android specifies a “compatibility mode” in which the framework operates in a 6328'normal' screen size equivalent (320dp width) mode for the benefit of legacy 6329applications not developed for old versions of Android that pre-date 6330screen-size independence. 6331 </p> 6332 <ul> 6333 <li> 6334 Android Automotive does not support legacy compatibility mode. 6335 </li> 6336 <li> 6337 All other device implementations MUST include support for legacy 6338application compatibility mode as implemented by the upstream Android open 6339source code. That is, device implementations MUST NOT alter the triggers or 6340thresholds at which compatibility mode is activated, and MUST NOT alter the 6341behavior of the compatibility mode itself. 6342 </li> 6343 </ul> 6344 <h3 id="7_1_6_screen_technology"> 6345 7.1.6. Screen Technology 6346 </h3> 6347 <p> 6348 The Android platform includes APIs that allow applications to render rich 6349graphics to the display. Devices MUST support all of these APIs as defined by 6350the Android SDK unless specifically allowed in this document. 6351 </p> 6352 <ul> 6353 <li> 6354 Devices MUST support displays capable of rendering 16-bit color graphics 6355and SHOULD support displays capable of 24-bit color graphics. 6356 </li> 6357 <li> 6358 Devices MUST support displays capable of rendering animations. 6359 </li> 6360 <li> 6361 The display technology used MUST have a pixel aspect ratio (PAR) between 63620.9 and 1.15. That is, the pixel aspect ratio MUST be near square (1.0) with a 636310 ~ 15% tolerance. 6364 </li> 6365 </ul> 6366 <h3 id="7_1_7_secondary_displays"> 6367 7.1.7. Secondary Displays 6368 </h3> 6369 <p> 6370 Android includes support for secondary display to enable media sharing 6371capabilities and developer APIs for accessing external displays. If a device 6372supports an external display either via a wired, wireless, or an embedded 6373additional display connection then the device implementation MUST implement the 6374 <a href="http://developer.android.com/reference/android/hardware/display/DisplayManager.html"> 6375 display manager API</a> as described in the Android SDK documentation. 6376 </p> 6377 <h2 id="7_2_input_devices"> 6378 7.2. Input Devices 6379 </h2> 6380 <p> 6381 Devices MUST support a touchscreen or meet the requirements listed in 7.2.2 for 6382non-touch navigation. 6383 </p> 6384 <h3 id="7_2_1_keyboard"> 6385 7.2.1. Keyboard 6386 </h3> 6387 <div class="note"> 6388 Android Watch and Android Automotive implementations MAY implement a soft 6389keyboard. All other device implementations MUST implement a soft keyboard and: 6390 </div> 6391 <p> 6392 Device implementations: 6393 </p> 6394 <ul> 6395 <li> 6396 MUST include support for the Input Management Framework (which allows 6397third-party developers to create Input Method Editors—i.e. soft keyboard) as 6398detailed at 6399 <a href="http://developer.android.com">http://developer.android.com</a>. 6400 </li> 6401 <li> 6402 MUST provide at least one soft keyboard implementation (regardless of 6403whether a hard keyboard is present) except for Android Watch devices where the 6404screen size makes it less reasonable to have a soft keyboard. 6405 </li> 6406 <li> 6407 MAY include additional soft keyboard implementations. 6408 </li> 6409 <li> 6410 MAY include a hardware keyboard. 6411 </li> 6412 <li> 6413 MUST NOT include a hardware keyboard that does not match one of the formats 6414specified in 6415 <a href="http://developer.android.com/reference/android/content/res/Configuration.html">android.content.res.Configuration.keyboard</a> (QWERTY or 12-key). 6416 </li> 6417 </ul> 6418 <h3 id="7_2_2_non_touch_navigation"> 6419 7.2.2. Non-touch Navigation 6420 </h3> 6421 <div class="note"> 6422 Android Television devices MUST support D-pad. 6423 </div> 6424 <p> 6425 Device implementations: 6426 </p> 6427 <ul> 6428 <li> 6429 MAY omit a non-touch navigation option (trackball, d-pad, or wheel) if the 6430device implementation is not an Android Television device. 6431 </li> 6432 <li> 6433 MUST report the correct value for 6434 <a href="http://developer.android.com/reference/android/content/res/Configuration.html">android.content.res.Configuration.navigation</a>. 6435 </li> 6436 <li> 6437 MUST provide a reasonable alternative user interface mechanism for the 6438selection and editing of text, compatible with Input Management Engines. The 6439upstream Android open source implementation includes a selection mechanism 6440suitable for use with devices that lack non-touch navigation inputs. 6441 </li> 6442 </ul> 6443 <h3 id="7_2_3_navigation_keys"> 6444 7.2.3. Navigation Keys 6445 </h3> 6446 <div class="note"> 6447 The availability and visibility requirement of the Home, Recents, and Back 6448functions differ between device types as described in this section. 6449 </div> 6450 <p> 6451 The Home, Recents, and Back functions (mapped to the key events KEYCODE_HOME, 6452KEYCODE_APP_SWITCH, KEYCODE_BACK, respectively) are essential to the Android 6453navigation paradigm and therefore: 6454 </p> 6455 <ul> 6456 <li> 6457 Android Handheld device implementations MUST provide the Home, Recents, and 6458 Back functions. 6459 </li> 6460 <li> 6461 Android Television device implementations MUST provide the Home and Back 6462 functions. 6463 </li> 6464 <li> 6465 Android Watch device implementations MUST have the Home function available 6466 to the user, and the Back function except for when it is in 6467 <code> 6468 UI_MODE_TYPE_WATCH 6469 </code>. 6470 </li> 6471 <li> 6472 Android Watch device implementations, and no other Android device types, 6473 MAY consume the long press event on the key event 6474 <a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BACK"> 6475 <code>KEYCODE_BACK</code></a> 6476 and omit it from being sent to the foreground application. 6477 </li> 6478 <li> 6479 Android Automotive implementations MUST provide the Home function and MAY 6480 provide Back and Recent functions. 6481 </li> 6482 <li> 6483 All other types of device implementations MUST provide the Home and Back 6484 functions. 6485 </li> 6486 </ul> 6487 <p> 6488 These functions MAY be implemented via dedicated physical buttons (such as 6489mechanical or capacitive touch buttons), or MAY be implemented using dedicated 6490software keys on a distinct portion of the screen, gestures, touch panel, etc. 6491Android supports both implementations. All of these functions MUST be accessible 6492with a single action (e.g. tap, double-click or gesture) when visible. 6493 </p> 6494 <p> 6495 Recents function, if provided, MUST have a visible button or icon unless hidden 6496together with other navigation functions in full-screen mode. This does not 6497apply to devices upgrading from earlier Android versions that have physical 6498buttons for navigation and no recents key. 6499 </p> 6500 <p> 6501 The Home and Back functions, if provided, MUST each have a visible button or 6502icon unless hidden together with other navigation functions in full-screen mode 6503or when the uiMode UI_MODE_TYPE_MASK is set to UI_MODE_TYPE_WATCH. 6504 </p> 6505 <p> 6506 The Menu function is deprecated in favor of action bar since Android 4.0. 6507Therefore the new device implementations shipping with Android 7.0 6508and later MUST NOT implement a dedicated physical button for the Menu function. 6509Older device implementations SHOULD NOT implement a dedicated physical button 6510for the Menu function, but if the physical Menu button is implemented and the 6511device is running applications with targetSdkVersion > 10, the device 6512implementation: 6513 </p> 6514 <ul> 6515 <li> 6516 MUST display the action overflow button on the action bar when it is visible 6517and the resulting action overflow menu popup is not empty. For a device 6518implementation launched before Android 4.4 but upgrading to Android 65197.0, this is RECOMMENDED. 6520 </li> 6521 <li> 6522 MUST NOT modify the position of the action overflow popup displayed by 6523selecting the overflow button in the action bar. 6524 </li> 6525 <li> 6526 MAY render the action overflow popup at a modified position on the screen 6527when it is displayed by selecting the physical menu button. 6528 </li> 6529 </ul> 6530 <p> 6531 For backwards compatibility, device implementations MUST make the Menu function 6532available to applications when targetSdkVersion is less than 10, either by a 6533physical button, a software key, or gestures. This Menu function should be 6534presented unless hidden together with other navigation functions. 6535 </p> 6536 <p> 6537 Android device implementations supporting the 6538 <a href="http://developer.android.com/reference/android/content/Intent.html#ACTION_ASSIST">Assist action</a> and/or 6539 <a href="https://developer.android.com/reference/android/service/voice/VoiceInteractionService.html"> 6540 <code> VoiceInteractionService</code></a> 6541 MUST be able to launch an assist app with a single interaction (e.g. tap, 6542double-click, or gesture) when other navigation keys are visible. It is STRONGLY 6543RECOMMENDED to use long press on home as this interaction. The designated 6544interaction MUST launch the user-selected assist app, in other words the app 6545that implements a VoiceInteractionService, or an activity handling the ACTION_ASSIST intent. 6546 </p> 6547 <p> 6548 Device implementations MAY use a distinct portion of the screen to display the 6549navigation keys, but if so, MUST meet these requirements: 6550 </p> 6551 <ul> 6552 <li> 6553 Device implementation navigation keys MUST use a distinct portion of the 6554screen, not available to applications, and MUST NOT obscure or otherwise 6555interfere with the portion of the screen available to applications. 6556 </li> 6557 <li> 6558 Device implementations MUST make available a portion of the display to 6559applications that meets the requirements defined in 6560 <a href="#7_1_1_screen_configuration"> 6561 section 65627.1.1 6563 </a> 6564 . 6565 </li> 6566 <li> 6567 Device implementations MUST display the navigation keys when applications do 6568not specify a system UI mode, or specify SYSTEM_UI_FLAG_VISIBLE. 6569 </li> 6570 <li> 6571 Device implementations MUST present the navigation keys in an unobtrusive 6572“low profile” (eg. dimmed) mode when applications specify 6573SYSTEM_UI_FLAG_LOW_PROFILE. 6574 </li> 6575 <li> 6576 Device implementations MUST hide the navigation keys when applications 6577specify SYSTEM_UI_FLAG_HIDE_NAVIGATION. 6578 </li> 6579 </ul> 6580 <h3 id="7_2_4_touchscreen_input"> 6581 7.2.4. Touchscreen Input 6582 </h3> 6583 <div class="note"> 6584 Android Handhelds and Watch Devices MUST support touchscreen input. 6585 </div> 6586 <p> 6587 Device implementations SHOULD have a pointer input system of some kind (either 6588mouse-like or touch). However, if a device implementation does not support a 6589pointer input system, it MUST NOT report the android.hardware.touchscreen or 6590android.hardware.faketouch feature constant. Device implementations that do 6591include a pointer input system: 6592 </p> 6593 <ul> 6594 <li> 6595 SHOULD support fully independently tracked pointers, if the device input 6596system supports multiple pointers. 6597 </li> 6598 <li> 6599 MUST report the value of 6600 <a href="http://developer.android.com/reference/android/content/res/Configuration.html">android.content.res.Configuration.touchscreen</a> corresponding to the type of the specific touchscreen on the device. 6601 </li> 6602 </ul> 6603 <p> 6604 Android includes support for a variety of touchscreens, touch pads, and fake 6605touch input devices. 6606 <a href="http://source.android.com/devices/tech/input/touch-devices.html"> 6607 Touchscreen based device implementations</a> are associated with a display 6608 such that the user has the impression of directly 6609manipulating items on screen. Since the user is directly touching the screen, 6610the system does not require any additional affordances to indicate the objects 6611being manipulated. In contrast, a fake touch interface provides a user input 6612system that approximates a subset of touchscreen capabilities. For example, a 6613mouse or remote control that drives an on-screen cursor approximates touch, but 6614requires the user to first point or focus then click. Numerous input devices 6615like the mouse, trackpad, gyro-based air mouse, gyro-pointer, joystick, and 6616multi-touch trackpad can support fake touch interactions. Android includes the 6617feature constant android.hardware.faketouch, which corresponds to a 6618high-fidelity non-touch (pointer-based) input device such as a mouse or trackpad 6619that can adequately emulate touch-based input (including basic gesture support), 6620and indicates that the device supports an emulated subset of touchscreen 6621functionality. Device implementations that declare the fake touch feature MUST 6622meet the fake touch requirements in 6623 <a href="#7_2_5_fake_touch_input">section 7.2.5</a>. 6624 </p> 6625 <p> 6626 Device implementations MUST report the correct feature corresponding to the type 6627of input used. Device implementations that include a touchscreen (single-touch 6628or better) MUST report the platform feature constant 6629android.hardware.touchscreen. Device implementations that report the platform 6630feature constant android.hardware.touchscreen MUST also report the platform 6631feature constant android.hardware.faketouch. Device implementations that do not 6632include a touchscreen (and rely on a pointer device only) MUST NOT report any 6633touchscreen feature, and MUST report only android.hardware.faketouch if they 6634meet the fake touch requirements in 6635 <a href="#7_2_5_fake_touch_input">section 7.2.5</a>. 6636 </p> 6637 <h3 id="7_2_5_fake_touch_input"> 6638 7.2.5. Fake Touch Input 6639 </h3> 6640 <p> 6641 Device implementations that declare support for android.hardware.faketouch: 6642 </p> 6643 <ul> 6644 <li> 6645 MUST report the 6646 <a href="http://developer.android.com/reference/android/view/MotionEvent.html"> 6647 absolute X and Y screen positions</a> of the pointer location and display a visual pointer on the screen. 6648 </li> 6649 <li> 6650 MUST report touch event with the action code that specifies the state change 6651that occurs on the pointer 6652 <a href="http://developer.android.com/reference/android/view/MotionEvent.html"> 6653 going down or up on the screen</a>. 6654 </li> 6655 <li> 6656 MUST support pointer down and up on an object on the screen, which allows 6657users to emulate tap on an object on the screen. 6658 </li> 6659 <li> 6660 MUST support pointer down, pointer up, pointer down then pointer up in the 6661same place on an object on the screen within a time threshold, which allows 6662users to 6663 <a href="http://developer.android.com/reference/android/view/MotionEvent.html"> 6664 emulate double tap</a> on an object on the screen. 6665 </li> 6666 <li> 6667 MUST support pointer down on an arbitrary point on the screen, pointer move 6668to any other arbitrary point on the screen, followed by a pointer up, which 6669allows users to emulate a touch drag. 6670 </li> 6671 <li> 6672 MUST support pointer down then allow users to quickly move the object to a 6673different position on the screen and then pointer up on the screen, which allows 6674users to fling an object on the screen. 6675 </li> 6676 </ul> 6677 <p> 6678 Devices that declare support for android.hardware.faketouch.multitouch.distinct 6679MUST meet the requirements for faketouch above, and MUST also support distinct 6680tracking of two or more independent pointer inputs. 6681 </p> 6682 <h3 id="7_2_6_game_controller_support"> 6683 7.2.6. Game Controller Support 6684 </h3> 6685 <p> 6686 Android Television device implementations MUST support button mappings for game 6687controllers as listed below. The upstream Android implementation includes 6688implementation for game controllers that satisfies this requirement. 6689 </p> 6690 <h4 id="7_2_6_1_button_mappings"> 6691 7.2.6.1. Button Mappings 6692 </h4> 6693 <p> 6694 Android Television device implementations MUST support the following key mappings: 6695 </p> 6696 <table> 6697 <tr> 6698 <th> 6699 Button 6700 </th> 6701 <th> 6702 HID Usage 6703 <sup> 6704 2 6705 </sup> 6706 </th> 6707 <th> 6708 Android Button 6709 </th> 6710 </tr> 6711 <tr> 6712 <td> 6713 <a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BUTTON_A">A</a> <sup> 6714 1 6715 </sup> 6716 </td> 6717 <td> 6718 0x09 0x0001 6719 </td> 6720 <td> 6721 KEYCODE_BUTTON_A (96) 6722 </td> 6723 </tr> 6724 <tr> 6725 <td> 6726 <a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BUTTON_B">B</a> <sup> 6727 1 6728 </sup> 6729 </td> 6730 <td> 6731 0x09 0x0002 6732 </td> 6733 <td> 6734 KEYCODE_BUTTON_B (97) 6735 </td> 6736 </tr> 6737 <tr> 6738 <td> 6739 <a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BUTTON_X">X</a> <sup> 6740 1 6741 </sup> 6742 </td> 6743 <td> 6744 0x09 0x0004 6745 </td> 6746 <td> 6747 KEYCODE_BUTTON_X (99) 6748 </td> 6749 </tr> 6750 <tr> 6751 <td> 6752 <a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BUTTON_Y">Y</a> <sup> 6753 1 6754 </sup> 6755 </td> 6756 <td> 6757 0x09 0x0005 6758 </td> 6759 <td> 6760 KEYCODE_BUTTON_Y (100) 6761 </td> 6762 </tr> 6763 <tr> 6764 <td> 6765 <a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_DPAD_UP">D-pad up</a> <sup> 6766 1 6767 </sup> 6768 <br/> 6769 <a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_DPAD_DOWN">D-pad down</a> <sup> 6770 1 6771 </sup> 6772 </td> 6773 <td> 6774 0x01 0x0039 6775 <sup> 6776 3 6777 </sup> 6778 </td> 6779 <td> 6780 <a href="http://developer.android.com/reference/android/view/MotionEvent.html#AXIS_HAT_Y">AXIS_HAT_Y</a> <sup> 6781 4 6782 </sup> 6783 </td> 6784 </tr> 6785 <tr> 6786 <td> 6787 <a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_DPAD_LEFT">D-pad left</a> 1 6788 <br/> 6789 <a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_DPAD_RIGHT">D-pad right</a> <sup> 6790 1 6791 </sup> 6792 </td> 6793 <td> 6794 0x01 0x0039 6795 <sup> 6796 3 6797 </sup> 6798 </td> 6799 <td> 6800 <a href="http://developer.android.com/reference/android/view/MotionEvent.html#AXIS_HAT_X">AXIS_HAT_X</a> <sup> 6801 4 6802 </sup> 6803 </td> 6804 </tr> 6805 <tr> 6806 <td> 6807 <a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BUTTON_L1">Left shoulder button</a> <sup> 6808 1 6809 </sup> 6810 </td> 6811 <td> 6812 0x09 0x0007 6813 </td> 6814 <td> 6815 KEYCODE_BUTTON_L1 (102) 6816 </td> 6817 </tr> 6818 <tr> 6819 <td> 6820 <a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BUTTON_R1">Right shoulder button</a> <sup> 6821 1 6822 </sup> 6823 </td> 6824 <td> 6825 0x09 0x0008 6826 </td> 6827 <td> 6828 KEYCODE_BUTTON_R1 (103) 6829 </td> 6830 </tr> 6831 <tr> 6832 <td> 6833 <a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BUTTON_THUMBL">Left stick click</a> <sup> 6834 1 6835 </sup> 6836 </td> 6837 <td> 6838 0x09 0x000E 6839 </td> 6840 <td> 6841 KEYCODE_BUTTON_THUMBL (106) 6842 </td> 6843 </tr> 6844 <tr> 6845 <td> 6846 <a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BUTTON_THUMBR">Right stick click</a> <sup> 6847 1 6848 </sup> 6849 </td> 6850 <td> 6851 0x09 0x000F 6852 </td> 6853 <td> 6854 KEYCODE_BUTTON_THUMBR (107) 6855 </td> 6856 </tr> 6857 <tr> 6858 <td> 6859 <a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_HOME">Home</a> <sup> 6860 1 6861 </sup> 6862 </td> 6863 <td> 6864 0x0c 0x0223 6865 </td> 6866 <td> 6867 KEYCODE_HOME (3) 6868 </td> 6869 </tr> 6870 <tr> 6871 <td> 6872 <a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BACK">Back</a> <sup> 6873 1 6874 </sup> 6875 </td> 6876 <td> 6877 0x0c 0x0224 6878 </td> 6879 <td> 6880 KEYCODE_BACK (4) 6881 </td> 6882 </tr> 6883 </table> 6884 <p class="table_footnote"> 6885 1 6886 <a href="http://developer.android.com/reference/android/view/KeyEvent.html">KeyEvent</a> </p> 6887 <p class="table_footnote"> 6888 2 The above HID usages must be declared within a Game 6889pad CA (0x01 0x0005). 6890 </p> 6891 <p class="table_footnote"> 6892 3 This usage must have a Logical Minimum of 0, a 6893Logical Maximum of 7, a Physical Minimum of 0, a Physical Maximum of 315, Units 6894in Degrees, and a Report Size of 4. The logical value is defined to be the 6895clockwise rotation away from the vertical axis; for example, a logical value of 68960 represents no rotation and the up button being pressed, while a logical value 6897of 1 represents a rotation of 45 degrees and both the up and left keys being 6898pressed. 6899 </p> 6900 <p class="table_footnote"> 6901 4 6902 <a href="http://developer.android.com/reference/android/view/MotionEvent.html">MotionEvent</a> </p> 6903 <table> 6904 <tr> 6905 <th> 6906 Analog Controls 6907 <sup> 6908 1 6909 </sup> 6910 </th> 6911 <th> 6912 HID Usage 6913 </th> 6914 <th> 6915 Android Button 6916 </th> 6917 </tr> 6918 <tr> 6919 <td> 6920 <a href="http://developer.android.com/reference/android/view/MotionEvent.html#AXIS_LTRIGGER">Left Trigger</a> </td> 6921 <td> 6922 0x02 0x00C5 6923 </td> 6924 <td> 6925 AXIS_LTRIGGER 6926 </td> 6927 </tr> 6928 <tr> 6929 <td> 6930 <a href="http://developer.android.com/reference/android/view/MotionEvent.html#AXIS_THROTTLE">Right Trigger</a> </td> 6931 <td> 6932 0x02 0x00C4 6933 </td> 6934 <td> 6935 AXIS_RTRIGGER 6936 </td> 6937 </tr> 6938 <tr> 6939 <td> 6940 <a href="http://developer.android.com/reference/android/view/MotionEvent.html#AXIS_Y">Left Joystick</a> </td> 6941 <td> 6942 0x01 0x0030 6943 <br/> 6944 0x01 0x0031 6945 </td> 6946 <td> 6947 AXIS_X 6948 <br/> 6949 AXIS_Y 6950 </td> 6951 </tr> 6952 <tr> 6953 <td> 6954 <a href="http://developer.android.com/reference/android/view/MotionEvent.html#AXIS_Z">Right Joystick</a> </td> 6955 <td> 6956 0x01 0x0032 6957 <br/> 6958 0x01 0x0035 6959 </td> 6960 <td> 6961 AXIS_Z 6962 <br/> 6963 AXIS_RZ 6964 </td> 6965 </tr> 6966 </table> 6967 <p class="table_footnote"> 6968 1 6969 <a href="http://developer.android.com/reference/android/view/MotionEvent.html">MotionEvent</a> </p> 6970 <h3 id="7_2_7_remote_control"> 6971 7.2.7. Remote Control 6972 </h3> 6973 <p> 6974 Android Television device implementations SHOULD provide a remote control to 6975allow users to access the TV interface. The remote control MAY be a physical 6976remote or can be a software-based remote that is accessible from a mobile phone 6977or tablet. The remote control MUST meet the requirements defined below. 6978 </p> 6979 <ul> 6980 <li> 6981 <strong> 6982 Search affordance 6983 </strong> 6984 . Device implementations MUST fire KEYCODE_SEARCH when 6985the user invokes voice search either on the physical or software-based remote. 6986 </li> 6987 <li> 6988 <strong> 6989 Navigation 6990 </strong> 6991 . All Android Television remotes MUST include 6992 <a href="http://developer.android.com/reference/android/view/KeyEvent.html"> 6993 Back, Home, and 6994Select buttons and support for D-pad events</a>. 6995 </li> 6996 </ul> 6997 <h2 id="7_3_sensors"> 6998 7.3. Sensors 6999 </h2> 7000 <p> 7001 Android includes APIs for accessing a variety of sensor types. Devices 7002implementations generally MAY omit these sensors, as provided for in the 7003following subsections. If a device includes a particular sensor type that has a 7004corresponding API for third-party developers, the device implementation MUST 7005implement that API as described in the Android SDK documentation and the 7006Android Open Source documentation on 7007 <a href="http://source.android.com/devices/sensors/">sensors</a>. For example, device 7008implementations: 7009 </p> 7010 <ul> 7011 <li> 7012 MUST accurately report the presence or absence of sensors per the 7013 <a href="http://developer.android.com/reference/android/content/pm/PackageManager.html">android.content.pm.PackageManager</a> class. 7014 </li> 7015 <li> 7016 MUST return an accurate list of supported sensors via the 7017SensorManager.getSensorList() and similar methods. 7018 </li> 7019 <li> 7020 MUST behave reasonably for all other sensor APIs (for example, by returning 7021true or false as appropriate when applications attempt to register listeners, 7022not calling sensor listeners when the corresponding sensors are not present; 7023etc.). 7024 </li> 7025 <li> 7026 MUST 7027 <a href="http://developer.android.com/reference/android/hardware/SensorEvent.html"> 7028 report all sensor measurements</a> using the relevant International System of Units (metric) values for each 7029sensor type as defined in the Android SDK documentation. 7030 </li> 7031 <li> 7032 SHOULD 7033 <a href="http://developer.android.com/reference/android/hardware/SensorEvent.html#timestamp"> 7034 report the event time</a> in nanoseconds as defined in the Android SDK documentation, representing the 7035time the event happened and synchronized with the 7036SystemClock.elapsedRealtimeNano() clock. Existing and new Android devices are 7037 <strong> 7038 STRONGLY RECOMMENDED 7039 </strong> 7040 to meet these requirements so they will be able to 7041upgrade to the future platform releases where this might become a REQUIRED 7042component. The synchronization error SHOULD be below 100 milliseconds. 7043 </li> 7044 <li> 7045 MUST report sensor data with a maximum latency of 100 milliseconds + 2 * 7046sample_time for the case of a sensor streamed with a minimum required latency 7047of 5 ms + 2 * sample_time when the application processor is active. This delay 7048does not include any filtering delays. 7049 </li> 7050 <li> 7051 MUST report the first sensor sample within 400 milliseconds + 2 * 7052sample_time of the sensor being activated. It is acceptable for this sample to 7053have an accuracy of 0. 7054 </li> 7055 </ul> 7056 <p> 7057 The list above is not comprehensive; the documented behavior of the Android SDK 7058and the Android Open Source Documentations on 7059 <a href="http://source.android.com/devices/sensors/">sensors</a> is to be considered 7060authoritative. 7061 </p> 7062 <p> 7063 Some sensor types are composite, meaning they can be derived from data provided 7064by one or more other sensors. (Examples include the orientation sensor and the 7065linear acceleration sensor.) Device implementations SHOULD implement these 7066sensor types, when they include the prerequisite physical sensors as described 7067in 7068 <a href="https://source.android.com/devices/sensors/sensor-types.html"> 7069 sensor types</a>. If a 7070device implementation includes a composite sensor it MUST implement the sensor 7071as described in the Android Open Source documentation on 7072 <a href="https://source.android.com/devices/sensors/sensor-types.html#composite_sensor_type_summary"> 7073 composite sensors</a>.</p> 7074 <p> 7075 Some Android sensors support a 7076 <a href="https://source.android.com/devices/sensors/report-modes.html#continuous"> 7077 “continuous” trigger mode</a>, 7078which returns data continuously. For any API indicated by the Android SDK 7079documentation to be a continuous sensor, device implementations MUST 7080continuously provide periodic data samples that SHOULD have a jitter below 3%, 7081where jitter is defined as the standard deviation of the difference of the 7082reported timestamp values between consecutive events. 7083 </p> 7084 <p> 7085 Note that the device implementations MUST ensure that the sensor event stream 7086MUST NOT prevent the device CPU from entering a suspend state or waking up from 7087a suspend state. 7088 </p> 7089 <p> 7090 Finally, when several sensors are activated, the power consumption SHOULD NOT 7091exceed the sum of the individual sensor’s reported power consumption. 7092 </p> 7093 <h3 id="7_3_1_accelerometer"> 7094 7.3.1. Accelerometer 7095 </h3> 7096 <p> 7097 Device implementations SHOULD include a 3-axis accelerometer. Android Handheld 7098devices, Android Automotive implementations, and Android Watch devices are STRONGLY 7099RECOMMENDED to include this sensor. If a device implementation does include a 71003-axis accelerometer, it: 7101 </p> 7102 <ul> 7103 <li> 7104 MUST implement and report 7105 <a href="http://developer.android.com/reference/android/hardware/Sensor.html#TYPE_ACCELEROMETER"> 7106 TYPE_ACCELEROMETER sensor</a>. 7107 </li> 7108 <li> 7109 MUST be able to report events up to a frequency of at least 50 Hz for 7110Android Watch devices as such devices have a stricter power constraint and 100 7111Hz for all other device types. 7112 </li> 7113 <li> 7114 SHOULD report events up to at least 200 Hz. 7115 </li> 7116 <li> 7117 MUST comply with the 7118 <a href="http://developer.android.com/reference/android/hardware/SensorEvent.html"> 7119 Android sensor coordinate system </a> 7120 as detailed in the Android APIs. Android Automotive implementations MUST comply 7121with the Android 7122 <a href="http://source.android.com/devices/sensors/sensor-types.html#auto_axes">car sensor coordinate system</a>. 7123 </li> 7124 <li> 7125 MUST be capable of measuring from freefall up to four times the gravity 7126(4g) or more on any axis. 7127 </li> 7128 <li> 7129 MUST have a resolution of at least 12-bits and SHOULD have a resolution of 7130at least 16-bits. 7131 </li> 7132 <li> 7133 SHOULD be calibrated while in use if the characteristics changes over the 7134life cycle and compensated, and preserve the compensation parameters between 7135device reboots. 7136 </li> 7137 <li> 7138 SHOULD be temperature compensated. 7139 </li> 7140 <li> 7141 MUST have a standard deviation no greater than 0.05 m/s^, where the 7142standard deviation should be calculated on a per axis basis on samples 7143collected over a period of at least 3 seconds at the fastest sampling rate. 7144 </li> 7145 <li> 7146 SHOULD implement the TYPE_SIGNIFICANT_MOTION, TYPE_TILT_DETECTOR, 7147TYPE_STEP_DETECTOR, TYPE_STEP_COUNTER composite sensors as described in the 7148Android SDK document. Existing and new Android devices are 7149 <strong> 7150 STRONGLY 7151RECOMMENDED 7152 </strong> 7153 to implement the TYPE_SIGNIFICANT_MOTION composite sensor. If any 7154of these sensors are implemented, the sum of their power consumption MUST 7155always be less than 4 mW and SHOULD each be below 2 mW and 0.5 mW for when the 7156device is in a dynamic or static condition. 7157 </li> 7158 <li> 7159 If a gyroscope sensor is included, MUST implement the TYPE_GRAVITY and 7160TYPE_LINEAR_ACCELERATION composite sensors and SHOULD implement the 7161TYPE_GAME_ROTATION_VECTOR composite sensor. Existing and new Android devices 7162are STRONGLY RECOMMENDED to implement the TYPE_GAME_ROTATION_VECTOR sensor. 7163 </li> 7164 <li> 7165 MUST implement a TYPE_ROTATION_VECTOR composite sensor, if a gyroscope 7166sensor and a magnetometer sensor is also included. 7167 </li> 7168 </ul> 7169 <h3 id="7_3_2_magnetometer"> 7170 7.3.2. Magnetometer 7171 </h3> 7172 <p> 7173 Device implementations SHOULD include a 3-axis magnetometer (compass). If a 7174device does include a 3-axis magnetometer, it: 7175 </p> 7176 <ul> 7177 <li> 7178 MUST implement the TYPE_MAGNETIC_FIELD sensor and SHOULD also implement 7179TYPE_MAGNETIC_FIELD_UNCALIBRATED sensor. Existing and new Android devices are 7180STRONGLY RECOMMENDED to implement the TYPE_MAGNETIC_FIELD_UNCALIBRATED sensor. 7181 </li> 7182 <li> 7183 MUST be able to report events up to a frequency of at least 10 Hz and 7184SHOULD report events up to at least 50 Hz. 7185 </li> 7186 <li> 7187 MUST comply with the 7188 <a href="http://developer.android.com/reference/android/hardware/SensorEvent.html"> 7189 Android sensor coordinate system</a> as detailed in the Android APIs. 7190 </li> 7191 <li> 7192 MUST be capable of measuring between -900 µT and +900 µT on each axis 7193before saturating. 7194 </li> 7195 <li> 7196 MUST have a hard iron offset value less than 700 µT and SHOULD have a value 7197below 200 µT, by placing the magnetometer far from dynamic (current-induced) 7198and static (magnet-induced) magnetic fields. 7199 </li> 7200 <li> 7201 MUST have a resolution equal or denser than 0.6 µT and SHOULD have a 7202resolution equal or denser than 0.2 µT. 7203 </li> 7204 <li> 7205 SHOULD be temperature compensated. 7206 </li> 7207 <li> 7208 MUST support online calibration and compensation of the hard iron bias, and 7209preserve the compensation parameters between device reboots. 7210 </li> 7211 <li> 7212 MUST have the soft iron compensation applied—the calibration can be done 7213either while in use or during the production of the device. 7214 </li> 7215 <li> 7216 SHOULD have a standard deviation, calculated on a per axis basis on samples 7217collected over a period of at least 3 seconds at the fastest sampling rate, no 7218greater than 0.5 µT. 7219 </li> 7220 <li> 7221 MUST implement a TYPE_ROTATION_VECTOR composite sensor, if an accelerometer 7222sensor and a gyroscope sensor is also included. 7223 </li> 7224 <li> 7225 MAY implement the TYPE_GEOMAGNETIC_ROTATION_VECTOR sensor if an 7226accelerometer sensor is also implemented. However if implemented, it MUST 7227consume less than 10 mW and SHOULD consume less than 3 mW when the sensor is 7228registered for batch mode at 10 Hz. 7229 </li> 7230 </ul> 7231 <h3 id="7_3_3_gps"> 7232 7.3.3. GPS 7233 </h3> 7234 <p> 7235 Device implementations SHOULD include a GPS/GNSS receiver. If a device implementation 7236does include a GPS/GNSS receiver and reports the capability to applications through the 7237 <code> 7238 android.hardware.location.gps 7239 </code> 7240 feature flag: 7241 </p> 7242 <ul> 7243 <li> 7244 It is STRONGLY RECOMMENDED that the device continue to deliver normal GPS/GNSS 7245 outputs to applications during an emergency phone call and that location output 7246 not be blocked during an emergency phone call. 7247 </li> 7248 <li> 7249 It MUST support location outputs at a rate of at least 1 Hz when requested via 7250 <code> 7251 LocationManager#requestLocationUpdate 7252 </code>. 7253 </li> 7254 <li> 7255 It MUST be able to determine the location in open-sky conditions (strong signals, 7256 negligible multipath, HDOP < 2) within 10 seconds (fast time to first fix), when 7257 connected to a 0.5 Mbps or faster data speed internet connection. This requirement 7258 is typically met by the use of some form of Assisted or Predicted GPS/GNSS technique 7259 to minimize GPS/GNSS lock-on time (Assistance data includes Reference Time, Reference 7260 Location and Satellite Ephemeris/Clock). 7261 <ul> 7262 <li> 7263 After making such a location calculation, it is STRONGLY RECOMMENDED for the device to 7264 be able to determine its location, in open sky, within 10 seconds, when location 7265 requests are restarted, up to an hour after the initial location calculation, 7266 even when the subsequent request is made without a data connection, and/or after a power 7267 cycle. 7268 </li> 7269 </ul> 7270 </li> 7271 <li> 7272 In open sky conditions after determining the location, while stationary or moving with less 7273 than 1 meter per second squared of acceleration: 7274 <ul> 7275 <li> 7276 It MUST be able to determine location within 20 meters, and speed within 0.5 meters 7277 per second, at least 95% of the time. 7278 </li> 7279 <li> 7280 It MUST simultaneously track and report via 7281 <a href="https://developer.android.com/reference/android/location/GnssStatus.Callback.html#GnssStatus.Callback()'">GnssStatus.Callback</a> at least 8 satellites from one constellation. 7282 </li> 7283 <li> 7284 It SHOULD be able to simultaneously track at least 24 satellites, from multiple 7285 constellations (e.g. GPS + at least one of Glonass, Beidou, Galileo). 7286 </li> 7287 </ul> 7288 </li> 7289 <li> 7290 It MUST report the GNSS technology generation through the test API ‘getGnssYearOfHardware’. 7291 </li> 7292 <li> 7293 It is STRONGLY RECOMMENDED to meet and MUST meet all requirements below if the GNSS technology 7294 generation is reported as the year "2016" or newer. 7295 <ul> 7296 <li> 7297 It MUST report GPS measurements, as soon as they are found, even if a location calculated 7298 from GPS/GNSS is not yet reported. 7299 </li> 7300 <li> 7301 It MUST report GPS pseudoranges and pseudorange rates, that, in open-sky conditions 7302 after determining the location, while stationary or moving with less than 0.2 meter 7303 per second squared of acceleration, are sufficient to calculate position within 7304 20 meters, and speed within 0.2 meters per second, at least 95% of the time. 7305 </li> 7306 </ul> 7307 </li> 7308 </ul> 7309 <p> 7310 Note that while some of the GPS requirements above are stated as STRONGLY RECOMMENDED, the 7311Compatibility Definition for the next major version is expected to change these to a MUST. 7312 </p> 7313 <h3 id="7_3_4_gyroscope"> 7314 7.3.4. Gyroscope 7315 </h3> 7316 <p> 7317 Device implementations SHOULD include a gyroscope (angular change sensor). 7318Devices SHOULD NOT include a gyroscope sensor unless a 3-axis accelerometer is 7319also included. If a device implementation includes a gyroscope, it: 7320 </p> 7321 <ul> 7322 <li> 7323 MUST implement the TYPE_GYROSCOPE sensor and SHOULD also implement 7324TYPE_GYROSCOPE_UNCALIBRATED sensor. Existing and new Android devices are 7325STRONGLY RECOMMENDED to implement the SENSOR_TYPE_GYROSCOPE_UNCALIBRATED 7326sensor. 7327 </li> 7328 <li> 7329 MUST be capable of measuring orientation changes up to 1,000 degrees per 7330second. 7331 </li> 7332 <li> 7333 MUST be able to report events up to a frequency of at least 50 Hz for 7334Android Watch devices as such devices have a stricter power constraint and 100 7335Hz for all other device types. 7336 </li> 7337 <li> 7338 SHOULD report events up to at least 200 Hz. 7339 </li> 7340 <li> 7341 MUST have a resolution of 12-bits or more and SHOULD have a resolution of 734216-bits or more. 7343 </li> 7344 <li> 7345 MUST be temperature compensated. 7346 </li> 7347 <li> 7348 MUST be calibrated and compensated while in use, and preserve the 7349compensation parameters between device reboots. 7350 </li> 7351 <li> 7352 MUST have a variance no greater than 1e-7 rad^2 / s^2 per Hz (variance per 7353Hz, or rad^2 / s). The variance is allowed to vary with the sampling rate, but 7354must be constrained by this value. In other words, if you measure the variance 7355of the gyro at 1 Hz sampling rate it should be no greater than 1e-7 rad^2/s^2. 7356 </li> 7357 <li> 7358 MUST implement a TYPE_ROTATION_VECTOR composite sensor, if an accelerometer 7359sensor and a magnetometer sensor is also included. 7360 </li> 7361 <li> 7362 If an accelerometer sensor is included, MUST implement the TYPE_GRAVITY and 7363TYPE_LINEAR_ACCELERATION composite sensors and SHOULD implement the 7364TYPE_GAME_ROTATION_VECTOR composite sensor. Existing and new Android devices 7365are STRONGLY RECOMMENDED to implement the TYPE_GAME_ROTATION_VECTOR sensor. 7366 </li> 7367 </ul> 7368 <h3 id="7_3_5_barometer"> 7369 7.3.5. Barometer 7370 </h3> 7371 <p> 7372 Device implementations SHOULD include a barometer (ambient air pressure 7373sensor). If a device implementation includes a barometer, it: 7374 </p> 7375 <ul> 7376 <li> 7377 MUST implement and report TYPE_PRESSURE sensor. 7378 </li> 7379 <li> 7380 MUST be able to deliver events at 5 Hz or greater. 7381 </li> 7382 <li> 7383 MUST have adequate precision to enable estimating altitude. 7384 </li> 7385 <li> 7386 MUST be temperature compensated. 7387 </li> 7388 </ul> 7389 <h3 id="7_3_6_thermometer"> 7390 7.3.6. Thermometer 7391 </h3> 7392 <p> 7393 Device implementations MAY include an ambient thermometer (temperature sensor). 7394If present, it MUST be defined as SENSOR_TYPE_AMBIENT_TEMPERATURE and it MUST 7395measure the ambient (room) temperature in degrees Celsius. 7396 </p> 7397 <p> 7398 Device implementations MAY but SHOULD NOT include a CPU temperature sensor. If 7399present, it MUST be defined as SENSOR_TYPE_TEMPERATURE, it MUST measure the 7400temperature of the device CPU, and it MUST NOT measure any other temperature. 7401Note the SENSOR_TYPE_TEMPERATURE sensor type was deprecated in Android 4.0. 7402 </p> 7403 <div class="note"> 7404 For Android Automotive implementations, SENSOR_TYPE_AMBIENT_TEMPERATURE MUST 7405measure the temperature inside the vehicle cabin. 7406 </div> 7407 <h3 id="7_3_7_photometer"> 7408 7.3.7. Photometer 7409 </h3> 7410 <p> 7411 Device implementations MAY include a photometer (ambient light sensor). 7412 </p> 7413 <h3 id="7_3_8_proximity_sensor"> 7414 7.3.8. Proximity Sensor 7415 </h3> 7416 <p> 7417 Device implementations MAY include a proximity sensor. Devices that can make a 7418voice call and indicate any value other than PHONE_TYPE_NONE in getPhoneType 7419SHOULD include a proximity sensor. If a device implementation does include a 7420proximity sensor, it: 7421 </p> 7422 <ul> 7423 <li> 7424 MUST measure the proximity of an object in the same direction as the 7425screen. That is, the proximity sensor MUST be oriented to detect objects close 7426to the screen, as the primary intent of this sensor type is to detect a phone 7427in use by the user. If a device implementation includes a proximity sensor with 7428any other orientation, it MUST NOT be accessible through this API. 7429 </li> 7430 <li> 7431 MUST have 1-bit of accuracy or more. 7432 </li> 7433 </ul> 7434 <h3 id="7_3_9_high_fidelity_sensors"> 7435 7.3.9. High Fidelity Sensors 7436 </h3> 7437 <p> 7438 Device implementations supporting a set of higher quality sensors that can meet 7439all the requirements listed in this section MUST identify the support through 7440the 7441 <code> 7442 android.hardware.sensor.hifi_sensors 7443 </code> 7444 feature flag. 7445 </p> 7446 <p> 7447 A device declaring android.hardware.sensor.hifi_sensors MUST support all of the 7448following sensor types meeting the quality requirements as below: 7449 </p> 7450 <ul> 7451 <li> 7452 SENSOR_TYPE_ACCELEROMETER 7453 <ul> 7454 <li> 7455 MUST have a measurement range between at least -8g and +8g. 7456 </li> 7457 <li> 7458 MUST have a measurement resolution of at least 1024 LSB/G. 7459 </li> 7460 <li> 7461 MUST have a minimum measurement frequency of 12.5 Hz or lower. 7462 </li> 7463 <li> 7464 MUST have a maximum measurement frequency of 400 Hz or higher. 7465 </li> 7466 <li> 7467 MUST have a measurement noise not above 400 uG/√Hz. 7468 </li> 7469 <li> 7470 MUST implement a non-wake-up form of this sensor with a buffering 7471 capability of at least 3000 sensor events. 7472 </li> 7473 <li> 7474 MUST have a batching power consumption not worse than 3 mW. 7475 </li> 7476 <li> 7477 SHOULD have a stationary noise bias stability of \<15 μg √Hz from 24hr static 7478 dataset. 7479 </li> 7480 <li> 7481 SHOULD have a bias change vs. temperature of ≤ +/- 1mg / °C. 7482 </li> 7483 <li> 7484 SHOULD have a best-fit line non-linearity of ≤ 0.5%, and sensitivity change vs. temperature of ≤ 7485 0.03%/C°. 7486 </li> 7487 </ul> 7488 </li> 7489 <li> 7490 <p> 7491 SENSOR_TYPE_GYROSCOPE 7492 </p> 7493 <ul> 7494 <li> 7495 MUST have a measurement range between at least -1000 and +1000 dps. 7496 </li> 7497 <li> 7498 MUST have a measurement resolution of at least 16 LSB/dps. 7499 </li> 7500 <li> 7501 MUST have a minimum measurement frequency of 12.5 Hz or lower. 7502 </li> 7503 <li> 7504 MUST have a maximum measurement frequency of 200 Hz or higher. 7505 </li> 7506 <li> 7507 MUST have a measurement noise not above 0.014°/s/√Hz. 7508 </li> 7509 <li> 7510 SHOULD have a stationary bias stability of < 0.0002 °/s √Hz from 24-hour static dataset. 7511 </li> 7512 <li> 7513 SHOULD have a bias change vs. temperature of ≤ +/- 0.05 °/ s / °C. 7514 </li> 7515 <li> 7516 SHOULD have a sensitivity change vs. temperature of ≤ 0.02% / °C. 7517 </li> 7518 <li> 7519 SHOULD have a best-fit line non-linearity of ≤ 0.2%. 7520 </li> 7521 <li> 7522 SHOULD have a noise density of ≤ 0.07 °/s/√Hz. 7523 </li> 7524 </ul> 7525 </li> 7526 <li> 7527 <p> 7528 SENSOR_TYPE_GYROSCOPE_UNCALIBRATED with the same quality requirements as 7529 SENSOR_TYPE_GYROSCOPE. 7530 </p> 7531 </li> 7532 <li> 7533 SENSOR_TYPE_GEOMAGNETIC_FIELD 7534 <ul> 7535 <li> 7536 MUST have a measurement range between at least -900 and +900 uT. 7537 </li> 7538 <li> 7539 MUST have a measurement resolution of at least 5 LSB/uT. 7540 </li> 7541 <li> 7542 MUST have a minimum measurement frequency of 5 Hz or lower. 7543 </li> 7544 <li> 7545 MUST have a maximum measurement frequency of 50 Hz or higher. 7546 </li> 7547 <li> 7548 MUST have a measurement noise not above 0.5 uT. 7549 </li> 7550 </ul> 7551 </li> 7552 <li> 7553 SENSOR_TYPE_MAGNETIC_FIELD_UNCALIBRATED with the same quality requirements 7554 as SENSOR_TYPE_GEOMAGNETIC_FIELD and in addition: 7555 <ul> 7556 <li> 7557 MUST implement a non-wake-up form of this sensor with a buffering 7558 capability of at least 600 sensor events. 7559 </li> 7560 </ul> 7561 </li> 7562 <li> 7563 SENSOR_TYPE_PRESSURE 7564 <ul> 7565 <li> 7566 MUST have a measurement range between at least 300 and 1100 hPa. 7567 </li> 7568 <li> 7569 MUST have a measurement resolution of at least 80 LSB/hPa. 7570 </li> 7571 <li> 7572 MUST have a minimum measurement frequency of 1 Hz or lower. 7573 </li> 7574 <li> 7575 MUST have a maximum measurement frequency of 10 Hz or higher. 7576 </li> 7577 <li> 7578 MUST have a measurement noise not above 2 Pa/√Hz. 7579 </li> 7580 <li> 7581 MUST implement a non-wake-up form of this sensor with a buffering 7582 capability of at least 300 sensor events. 7583 </li> 7584 <li> 7585 MUST have a batching power consumption not worse than 2 mW. 7586 </li> 7587 </ul> 7588 </li> 7589 <li> 7590 SENSOR_TYPE_GAME_ROTATION_VECTOR 7591 <ul> 7592 <li> 7593 MUST implement a non-wake-up form of this sensor with a buffering 7594 capability of at least 300 sensor events. 7595 </li> 7596 <li> 7597 MUST have a batching power consumption not worse than 4 mW. 7598 </li> 7599 </ul> 7600 </li> 7601 <li> 7602 SENSOR_TYPE_SIGNIFICANT_MOTION 7603 <ul> 7604 <li> 7605 MUST have a power consumption not worse than 0.5 mW when device is 7606 static and 1.5 mW when device is moving. 7607 </li> 7608 </ul> 7609 </li> 7610 <li> 7611 SENSOR_TYPE_STEP_DETECTOR 7612 <ul> 7613 <li> 7614 MUST implement a non-wake-up form of this sensor with a buffering 7615 capability of at least 100 sensor events. 7616 </li> 7617 <li> 7618 MUST have a power consumption not worse than 0.5 mW when device is 7619 static and 1.5 mW when device is moving. 7620 </li> 7621 <li> 7622 MUST have a batching power consumption not worse than 4 mW. 7623 </li> 7624 </ul> 7625 </li> 7626 <li> 7627 SENSOR_TYPE_STEP_COUNTER 7628 <ul> 7629 <li> 7630 MUST have a power consumption not worse than 0.5 mW when device is 7631 static and 1.5 mW when device is moving. 7632 </li> 7633 </ul> 7634 </li> 7635 <li> 7636 SENSOR_TILT_DETECTOR 7637 <ul> 7638 <li> 7639 MUST have a power consumption not worse than 0.5 mW when device is 7640 static and 1.5 mW when device is moving. 7641 </li> 7642 </ul> 7643 </li> 7644 </ul> 7645 <p> 7646 Also such a device MUST meet the following sensor subsystem requirements: 7647 </p> 7648 <ul> 7649 <li> 7650 The event timestamp of the same physical event reported by the 7651Accelerometer, Gyroscope sensor and Magnetometer MUST be within 2.5 7652milliseconds of each other. 7653 </li> 7654 <li> 7655 The Gyroscope sensor event timestamps MUST be on the same time base as the 7656camera subsystem and within 1 milliseconds of error. 7657 </li> 7658 <li> 7659 High Fidelity sensors MUST deliver samples to applications within 5 7660milliseconds from the time when the data is available on the physical sensor 7661to the application. 7662 </li> 7663 <li> 7664 The power consumption MUST not be higher than 0.5 mW when device is static 7665and 2.0 mW when device is moving when any combination of the following sensors 7666are enabled: 7667 <ul> 7668 <li> 7669 SENSOR_TYPE_SIGNIFICANT_MOTION 7670 </li> 7671 <li> 7672 SENSOR_TYPE_STEP_DETECTOR 7673 </li> 7674 <li> 7675 SENSOR_TYPE_STEP_COUNTER 7676 </li> 7677 <li> 7678 SENSOR_TILT_DETECTORS 7679 </li> 7680 </ul> 7681 </li> 7682 </ul> 7683 <p> 7684 Note that all power consumption requirements in this section do not include the 7685power consumption of the Application Processor. It is inclusive of the power 7686drawn by the entire sensor chain—the sensor, any supporting circuitry, any 7687dedicated sensor processing system, etc. 7688 </p> 7689 <p> 7690 The following sensor types MAY also be supported on a device implementation 7691declaring android.hardware.sensor.hifi_sensors, but if these sensor types are 7692present they MUST meet the following minimum buffering capability requirement: 7693 </p> 7694 <ul> 7695 <li> 7696 SENSOR_TYPE_PROXIMITY: 100 sensor events 7697 </li> 7698 </ul> 7699 <h3 id="7_3_10_fingerprint_sensor"> 7700 7.3.10. Fingerprint Sensor 7701 </h3> 7702 <p> 7703 Device implementations with a secure lock screen SHOULD include a fingerprint 7704sensor. If a device implementation includes a fingerprint sensor and has a 7705corresponding API for third-party developers, it: 7706 </p> 7707 <ul> 7708 <li> 7709 MUST declare support for the android.hardware.fingerprint feature. 7710 </li> 7711 <li> 7712 MUST fully implement the 7713 <a href="https://developer.android.com/reference/android/hardware/fingerprint/package-summary.html"> 7714 corresponding API</a> as described in the Android SDK documentation. 7715 </li> 7716 <li> 7717 MUST have a false acceptance rate not higher than 0.002%. 7718 </li> 7719 <li> 7720 Is STRONGLY RECOMMENDED to have a false rejection rate of less than 10%, as 7721measured on the device 7722 </li> 7723 <li> 7724 Is STRONGLY RECOMMENDED to have a latency below 1 second, measured from 7725when the fingerprint sensor is touched until the screen is unlocked, for one 7726enrolled finger. 7727 </li> 7728 <li> 7729 MUST rate limit attempts for at least 30 seconds after five false trials 7730for fingerprint verification. 7731 </li> 7732 <li> 7733 MUST have a hardware-backed keystore implementation, and perform the 7734fingerprint matching in a Trusted Execution Environment (TEE) or on a chip with 7735a secure channel to the TEE. 7736 </li> 7737 <li> 7738 MUST have all identifiable fingerprint data encrypted and cryptographically 7739authenticated such that they cannot be acquired, read or altered outside of the 7740Trusted Execution Environment (TEE) as documented in the 7741 <a href="https://source.android.com/devices/tech/security/authentication/fingerprint-hal.html"> 7742 implementation guidelines</a> on the Android Open Source Project site. 7743 </li> 7744 <li> 7745 MUST prevent adding a fingerprint without first establishing a chain of 7746trust by having the user confirm existing or add a new device credential 7747(PIN/pattern/password) using the TEE as implemented in the Android Open Source 7748project. 7749 </li> 7750 <li> 7751 MUST NOT enable 3rd-party applications to distinguish between individual 7752fingerprints. 7753 </li> 7754 <li> 7755 MUST honor the DevicePolicyManager.KEYGUARD_DISABLE_FINGERPRINT flag. 7756 </li> 7757 <li> 7758 MUST, when upgraded from a version earlier than Android 6.0, have the 7759fingerprint data securely migrated to meet the above requirements or removed. 7760 </li> 7761 <li> 7762 SHOULD use the Android Fingerprint icon provided in the Android Open Source 7763Project. 7764 </li> 7765 </ul> 7766 <h3 id="7_3_11_android_automotive-only_sensors"> 7767 7.3.11. Android Automotive-only sensors 7768 </h3> 7769 <p> 7770 Automotive-specific sensors are defined in the 7771 <code> 7772 android.car.CarSensorManager API 7773 </code>. 7774 </p> 7775 <h4 id="7_3_11_1_current_gear"> 7776 7.3.11.1. Current Gear 7777 </h4> 7778 <p> 7779 Android Automotive implementations SHOULD provide current gear as SENSOR_TYPE_GEAR. 7780 </p> 7781 <h4 id="7_3_11_2_day_night_mode"> 7782 7.3.11.2. Day Night Mode 7783 </h4> 7784 <p> 7785 Android Automotive implementations MUST support day/night mode defined as 7786SENSOR_TYPE_NIGHT. The value of this flag MUST be consistent with dashboard 7787day/night mode and SHOULD be based on ambient light sensor input. The 7788underlying ambient light sensor MAY be the same as 7789 <a href="#7_3_7_photometer">Photometer</a>. 7790 </p> 7791 <h4 id="7_3_11_3_driving_status"> 7792 7.3.11.3. Driving Status 7793 </h4> 7794 <p> 7795 Android Automotive implementations MUST support driving status defined as 7796SENSOR_TYPE_DRIVING_STATUS, with a default value of DRIVE_STATUS_UNRESTRICTED 7797when the vehicle is fully stopped and parked. It is the responsibility of device 7798manufacturers to configure SENSOR_TYPE_DRIVING_STATUS in compliance with all 7799laws and regulations that apply to markets where the product is shipping. 7800 </p> 7801 <h4 id="7_3_11_4_wheel_speed"> 7802 7.3.11.4. Wheel Speed 7803 </h4> 7804 <p> 7805 Android Automotive implementations MUST provide vehicle speed defined as 7806SENSOR_TYPE_CAR_SPEED. 7807 </p> 7808 <h2 id="7_3_12_pose_sensor"> 7809 7.3.12. Pose Sensor 7810 </h2> 7811 <p> 7812 Device implementations MAY support pose sensor with 6 degrees of freedom. Android Handheld 7813devices are RECOMMENDED to support this sensor. If a device implementation does support pose 7814sensor with 6 degrees of freedom, it: 7815 </p> 7816 <ul> 7817 <li> 7818 MUST implement and report 7819 <a href="https://developer.android.com/reference/android/hardware/Sensor.html#TYPE_POSE_6DOF"> 7820 <code> TYPE_POSE_6DOF</code></a> sensor. 7821 </li> 7822 <li> 7823 MUST be more accurate than the rotation vector alone. 7824 </li> 7825 </ul> 7826 <h2 id="7_4_data_connectivity"> 7827 7.4. Data Connectivity 7828 </h2> 7829 <h3 id="7_4_1_telephony"> 7830 7.4.1. Telephony 7831 </h3> 7832 <p> 7833 “Telephony” as used by the Android APIs and this document refers specifically 7834to hardware related to placing voice calls and sending SMS messages via a GSM 7835or CDMA network. While these voice calls may or may not be packet-switched, 7836they are for the purposes of Android considered independent of any data 7837connectivity that may be implemented using the same network. In other words, 7838the Android “telephony” functionality and APIs refer specifically to voice 7839calls and SMS. For instance, device implementations that cannot place calls or 7840send/receive SMS messages MUST NOT report the android.hardware.telephony 7841feature or any subfeatures, regardless of whether they use a cellular network 7842for data connectivity. 7843 </p> 7844 <p> 7845 Android MAY be used on devices that do not include telephony hardware. That is, 7846Android is compatible with devices that are not phones. However, if a device 7847implementation does include GSM or CDMA telephony, it MUST implement full 7848support for the API for that technology. Device implementations that do not 7849include telephony hardware MUST implement the full APIs as no-ops. 7850 </p> 7851 <h4 id="7_4_1_1_number_blocking_compatibility"> 7852 7.4.1.1. Number Blocking Compatibility 7853 </h4> 7854 <p> 7855 Android Telephony device implementations MUST include number blocking support 7856and: 7857 </p> 7858 <ul> 7859 <li> 7860 MUST fully implement 7861 <a href="http://developer.android.com/reference/android/provider/BlockedNumberContract.html">BlockedNumberContract</a> and the corresponding API as described in the SDK documentation. 7862 </li> 7863 <li> 7864 MUST block all calls and messages from a phone number in 7865'BlockedNumberProvider' without any interaction with apps. The only exception 7866is when number blocking is temporarily lifted as described in the SDK 7867documentation. 7868 </li> 7869 <li> 7870 MUST NOT write to the 7871 <a href="http://developer.android.com/reference/android/provider/CallLog.html">platform call log provider</a> for a blocked call. 7872 </li> 7873 <li> 7874 MUST NOT write to the 7875 <a href="http://developer.android.com/reference/android/provider/Telephony.html">telephony provider</a> for a blocked message. 7876 </li> 7877 <li> 7878 MUST implement a blocked numbers management UI, which is opened with the 7879intent returned by TelecomManager.createManageBlockedNumbersIntent() method. 7880 </li> 7881 <li> 7882 MUST NOT allow secondary users to view or edit the blocked numbers on the 7883device as the Android platform assumes the primary user to have full control 7884of the telephony services, a single instance, on the device. All blocking 7885related UI MUST be hidden for secondary users and the blocked list MUST still 7886be respected. 7887 </li> 7888 <li> 7889 SHOULD migrate the blocked numbers into the provider when a device updates 7890to Android 7.0. 7891 </li> 7892 </ul> 7893 <h3 id="7_4_2_ieee_802_11_(wi-fi)"> 7894 7.4.2. IEEE 802.11 (Wi-Fi) 7895 </h3> 7896 <p> 7897 All Android device implementations SHOULD include support for one or more forms 7898of 802.11. If a device implementation does include support for 802.11 and exposes the 7899functionality to a third-party application, it MUST implement the corresponding 7900Android API and: 7901 </p> 7902 <ul> 7903 <li> 7904 MUST report the hardware feature flag android.hardware.wifi. 7905 </li> 7906 <li> 7907 MUST implement the 7908 <a href="http://developer.android.com/reference/android/net/wifi/WifiManager.MulticastLock.html">multicast API</a> as described in the SDK documentation. 7909 </li> 7910 <li> 7911 MUST support multicast DNS (mDNS) and MUST NOT filter mDNS packets 7912(224.0.0.251) at any time of operation including: 7913 <ul> 7914 <li> 7915 Even when the screen is not in an active state. 7916 </li> 7917 <li> 7918 For Android Television device implementations, even when in standby 7919power states. 7920 </li> 7921 </ul> 7922 </li> 7923 </ul> 7924 <h4 id="7_4_2_1_wi-fi_direct"> 7925 7.4.2.1. Wi-Fi Direct 7926 </h4> 7927 <p> 7928 Device implementations SHOULD include support for Wi-Fi Direct (Wi-Fi 7929peer-to-peer). If a device implementation does include support for Wi-Fi 7930Direct, it MUST implement the 7931 <a href="http://developer.android.com/reference/android/net/wifi/p2p/WifiP2pManager.html">corresponding Android API</a> as described in the SDK documentation. If a device implementation includes 7932support for Wi-Fi Direct, then it: 7933 </p> 7934 <ul> 7935 <li> 7936 MUST report the hardware feature android.hardware.wifi.direct. 7937 </li> 7938 <li> 7939 MUST support regular Wi-Fi operation. 7940 </li> 7941 <li> 7942 SHOULD support concurrent Wi-Fi and Wi-Fi Direct operation. 7943 </li> 7944 </ul> 7945 <h4 id="7_4_2_2_wi-fi_tunneled_direct_link_setup"> 7946 7.4.2.2. Wi-Fi Tunneled Direct Link Setup 7947 </h4> 7948 <p> 7949 Device implementations SHOULD include support for 7950 <a href="http://developer.android.com/reference/android/net/wifi/WifiManager.html"> 7951 Wi-Fi Tunneled Direct Link Setup (TDLS)</a> as described in the Android SDK Documentation. If a device 7952implementation does include support for TDLS and TDLS is enabled by the 7953WiFiManager API, the device: 7954 </p> 7955 <ul> 7956 <li> 7957 SHOULD use TDLS only when it is possible AND beneficial. 7958 </li> 7959 <li> 7960 SHOULD have some heuristic and NOT use TDLS when its performance might be 7961worse than going through the Wi-Fi access point. 7962 </li> 7963 </ul> 7964 <h3 id="7_4_3_bluetooth"> 7965 7.4.3. Bluetooth 7966 </h3> 7967 <div class="note"> 7968 Android Watch implementations MUST support Bluetooth. Android Television 7969implementations MUST support Bluetooth and Bluetooth LE. Android Automotive 7970implementations MUST support Bluetooth and SHOULD support Bluetooth LE. 7971 </div> 7972 <p> 7973 Device implementations that support 7974 <code> 7975 android.hardware.vr.high_performance 7976 </code> 7977 feature MUST 7978support Bluetooth 4.2 and Bluetooth LE Data Length Extension. 7979 </p> 7980 <p> 7981 Android includes support for 7982 <a href="http://developer.android.com/reference/android/bluetooth/package-summary.html">Bluetooth and Bluetooth Low Energy</a>. Device implementations that include support for Bluetooth and Bluetooth Low 7983Energy MUST declare the relevant platform features (android.hardware.bluetooth 7984and android.hardware.bluetooth_le respectively) and implement the platform 7985APIs. Device implementations SHOULD implement relevant Bluetooth profiles such 7986as A2DP, AVCP, OBEX, etc. as appropriate for the device. 7987 </p> 7988 <p> 7989 Android Automotive implementations SHOULD support Message Access Profile (MAP). 7990Android Automotive implementations MUST support the following Bluetooth 7991profiles: 7992 </p> 7993 <ul> 7994 <li> 7995 Phone calling over Hands-Free Profile (HFP). 7996 </li> 7997 <li> 7998 Media playback over Audio Distribution Profile (A2DP). 7999 </li> 8000 <li> 8001 Media playback control over Remote Control Profile (AVRCP). 8002 </li> 8003 <li> 8004 Contact sharing using the Phone Book Access Profile (PBAP). 8005 </li> 8006 </ul> 8007 <p> 8008 Device implementations including support for Bluetooth Low Energy: 8009 </p> 8010 <ul> 8011 <li> 8012 MUST declare the hardware feature android.hardware.bluetooth_le. 8013 </li> 8014 <li> 8015 MUST enable the GATT (generic attribute profile) based Bluetooth APIs as 8016described in the SDK documentation and 8017 <a href="http://developer.android.com/reference/android/bluetooth/package-summary.html">android.bluetooth</a>. 8018 </li> 8019 <li> 8020 are STRONGLY RECOMMENDED to implement a Resolvable Private Address (RPA) 8021timeout no longer than 15 minutes and rotate the address at timeout to protect 8022user privacy. 8023 </li> 8024 <li> 8025 SHOULD support offloading of the filtering logic to the bluetooth chipset 8026when implementing the 8027 <a href="https://developer.android.com/reference/android/bluetooth/le/ScanFilter.html">ScanFilter API</a>, 8028and MUST report the correct value of where the filtering logic is implemented 8029whenever queried via the 8030android.bluetooth.BluetoothAdapter.isOffloadedFilteringSupported() method. 8031 </li> 8032 <li> 8033 SHOULD support offloading of the batched scanning to the bluetooth chipset, 8034but if not supported, MUST report ‘false’ whenever queried via the 8035android.bluetooth.BluetoothAdapter.isOffloadedScanBatchingSupported() method. 8036 </li> 8037 <li> 8038 SHOULD support multi advertisement with at least 4 slots, but if not 8039supported, MUST report ‘false’ whenever queried via the 8040android.bluetooth.BluetoothAdapter.isMultipleAdvertisementSupported() method. 8041 </li> 8042 </ul> 8043 <h3 id="7_4_4_near-field_communications"> 8044 7.4.4. Near-Field Communications 8045 </h3> 8046 <p> 8047 Device implementations SHOULD include a transceiver and related hardware for 8048Near-Field Communications (NFC). If a device implementation does include NFC 8049hardware and plans to make it available to third-party apps, then it: 8050 </p> 8051 <ul> 8052 <li> 8053 MUST report the android.hardware.nfc feature from the 8054 <a href="http://developer.android.com/reference/android/content/pm/PackageManager.html">android.content.pm.PackageManager.hasSystemFeature() method</a>. 8055 </li> 8056 <li> 8057 <p> 8058 MUST be capable of reading and writing NDEF messages via the following NFC 8059standards: 8060 </p> 8061 <ul> 8062 <li> 8063 MUST be capable of acting as an NFC Forum reader/writer (as defined by 8064the NFC Forum technical specification NFCForum-TS-DigitalProtocol-1.0) via the 8065following NFC standards: 8066 <ul> 8067 <li> 8068 NfcA (ISO14443-3A) 8069 </li> 8070 <li> 8071 NfcB (ISO14443-3B) 8072 </li> 8073 <li> 8074 NfcF (JIS X 6319-4) 8075 </li> 8076 <li> 8077 IsoDep (ISO 14443-4) 8078 </li> 8079 <li> 8080 NFC Forum Tag Types 1, 2, 3, 4 (defined by the NFC Forum) 8081 </li> 8082 <li> 8083 STRONGLY RECOMMENDED to be capable of reading and writing NDEF messages 8084as well as raw data via the following NFC standards. Note that while the NFC 8085standards below are stated as STRONGLY RECOMMENDED, the Compatibility 8086Definition for a future version is planned to change these to MUST. These 8087standards are optional in this version but will be required in future versions. 8088Existing and new devices that run this version of Android are very strongly 8089encouraged to meet these requirements now so they will be able to upgrade to 8090the future platform releases. 8091 </li> 8092 <li> 8093 NfcV (ISO 15693) 8094 </li> 8095 </ul> 8096 </li> 8097 <li> 8098 SHOULD be capable of reading the barcode and URL (if encoded) of 8099 <a href="http://developer.android.com/reference/android/nfc/tech/NfcBarcode.html">Thinfilm NFC Barcode</a> products. 8100 </li> 8101 <li> 8102 MUST be capable of transmitting and receiving data via the following 8103peer-to-peer standards and protocols: 8104 <ul> 8105 <li> 8106 ISO 18092 8107 </li> 8108 <li> 8109 LLCP 1.2 (defined by the NFC Forum) 8110 </li> 8111 <li> 8112 SDP 1.0 (defined by the NFC Forum) 8113 </li> 8114 <li> 8115 <a href="http://static.googleusercontent.com/media/source.android.com/en/us/compatibility/ndef-push-protocol.pdf">NDEF Push Protocol</a> </li> 8116 <li> 8117 SNEP 1.0 (defined by the NFC Forum) 8118 </li> 8119 </ul> 8120 </li> 8121 <li> 8122 MUST include support for 8123 <a href="http://developer.android.com/guide/topics/connectivity/nfc/nfc.html">Android Beam</a>. 8124 </li> 8125 <li> 8126 MUST implement the SNEP default server. Valid NDEF messages received by 8127 the default SNEP server MUST be dispatched to applications using the 8128 android.nfc.ACTION_NDEF_DISCOVERED intent. Disabling Android Beam in 8129 settings MUST NOT disable dispatch of incoming NDEF message. 8130 </li> 8131 <li> 8132 MUST honor the android.settings.NFCSHARING_SETTINGS intent to show 8133 <a href="http://developer.android.com/reference/android/provider/Settings.html#ACTION_NFCSHARING_SETTINGS">NFC sharing settings</a>. 8134 </li> 8135 <li> 8136 MUST implement the NPP server. Messages received by the NPP server MUST 8137 be processed the same way as the SNEP default server. 8138 </li> 8139 <li> 8140 MUST implement a SNEP client and attempt to send outbound P2P NDEF to 8141 the default SNEP server when Android Beam is enabled. If no default SNEP 8142 server is found then the client MUST attempt to send to an NPP server. 8143 </li> 8144 <li> 8145 MUST allow foreground activities to set the outbound P2P NDEF message 8146 using android.nfc.NfcAdapter.setNdefPushMessage, and 8147 android.nfc.NfcAdapter.setNdefPushMessageCallback, and 8148 android.nfc.NfcAdapter.enableForegroundNdefPush. 8149 </li> 8150 <li> 8151 SHOULD use a gesture or on-screen confirmation, such as 'Touch to Beam', 8152 before sending outbound P2P NDEF messages. 8153 </li> 8154 <li> 8155 <p> 8156 SHOULD enable Android Beam by default and MUST be able to send and 8157 receive using Android Beam, even when another proprietary NFC P2p mode 8158 is turned on. 8159 </p> 8160 </li> 8161 <li> 8162 <p> 8163 MUST support NFC Connection handover to Bluetooth when the device 8164supports Bluetooth Object Push Profile. Device implementations MUST support 8165connection handover to Bluetooth when using 8166android.nfc.NfcAdapter.setBeamPushUris, by implementing the “ 8167 <a href="http://members.nfc-forum.org/specs/spec_list/#conn_handover">Connection Handover version 1.2</a> ” and 8168“ 8169 <a href="http://members.nfc-forum.org/apps/group_public/download.php/18688/NFCForum-AD-BTSSP_1_1.pdf">Bluetooth Secure Simple Pairing Using NFC version 1.0</a> ” 8170specs from the NFC Forum. Such an implementation MUST implement the handover 8171LLCP service with service name “urn:nfc:sn:handover” for exchanging the 8172handover request/select records over NFC, and it MUST use the Bluetooth Object 8173Push Profile for the actual Bluetooth data transfer. For legacy reasons (to 8174remain compatible with Android 4.1 devices), the implementation SHOULD still 8175accept SNEP GET requests for exchanging the handover request/select records 8176over NFC. However an implementation itself SHOULD NOT send SNEP GET requests 8177for performing connection handover. 8178 </p> 8179 </li> 8180 <li> 8181 MUST poll for all supported technologies while in NFC discovery mode. 8182 </li> 8183 <li> 8184 SHOULD be in NFC discovery mode while the device is awake with the 8185screen active and the lock-screen unlocked. 8186 </li> 8187 </ul> 8188 </li> 8189 </ul> 8190 <p> 8191 (Note that publicly available links are not available for the JIS, ISO, and NFC 8192Forum specifications cited above.) 8193 </p> 8194 <p> 8195 Android includes support for NFC Host Card Emulation (HCE) mode. If a device 8196implementation does include an NFC controller chipset capable of HCE (for NfcA 8197and/or NfcB) and it supports Application ID (AID) routing, then it: 8198 </p> 8199 <ul> 8200 <li> 8201 MUST report the android.hardware.nfc.hce feature constant. 8202 </li> 8203 <li> 8204 MUST support 8205 <a href="http://developer.android.com/guide/topics/connectivity/nfc/hce.html"> 8206 NFC HCE APIs</a> as defined in the Android SDK. 8207 </li> 8208 </ul> 8209 <p> 8210 If a device implementation does include an NFC controller chipset capable of HCE 8211for NfcF, and it implements the feature for third-party applications, then it: 8212 </p> 8213 <ul> 8214 <li> 8215 MUST report the android.hardware.nfc.hcef feature constant. 8216 </li> 8217 <li> 8218 MUST implement the 8219 <a href="https://developer.android.com/reference/android/nfc/cardemulation/NfcFCardEmulation.html">NfcF Card Emulation APIs</a> as defined in the Android SDK. 8220 </li> 8221 </ul> 8222 <p> 8223 Additionally, device implementations MAY include reader/writer support for the 8224following MIFARE technologies. 8225 </p> 8226 <ul> 8227 <li> 8228 MIFARE Classic 8229 </li> 8230 <li> 8231 MIFARE Ultralight 8232 </li> 8233 <li> 8234 NDEF on MIFARE Classic 8235 </li> 8236 </ul> 8237 <p> 8238 Note that Android includes APIs for these MIFARE types. If a device 8239implementation supports MIFARE in the reader/writer role, it: 8240 </p> 8241 <ul> 8242 <li> 8243 MUST implement the corresponding Android APIs as documented by the Android SDK. 8244 </li> 8245 <li> 8246 MUST report the feature com.nxp.mifare from the 8247 <a href="http://developer.android.com/reference/android/content/pm/PackageManager.html">android.content.pm.PackageManager.hasSystemFeature()</a> method. Note that this is not a standard Android feature and as such does 8248 not appear as a constant in the android.content.pm.PackageManager class. 8249 </li> 8250 <li> 8251 MUST NOT implement the corresponding Android APIs nor report the 8252 com.nxp.mifare feature unless it also implements general NFC support as 8253 described in this section. 8254 </li> 8255 </ul> 8256 <p> 8257 If a device implementation does not include NFC hardware, it MUST NOT declare 8258the android.hardware.nfc feature from the 8259 <a href="http://developer.android.com/reference/android/content/pm/PackageManager.html">android.content.pm.PackageManager.hasSystemFeature()</a> method, and MUST implement the Android NFC API as a no-op. 8260 </p> 8261 <p> 8262 As the classes android.nfc.NdefMessage and android.nfc.NdefRecord represent a 8263protocol-independent data representation format, device implementations MUST 8264implement these APIs even if they do not include support for NFC or declare the 8265android.hardware.nfc feature. 8266 </p> 8267 <h3 id="7_4_5_minimum_network_capability"> 8268 7.4.5. Minimum Network Capability 8269 </h3> 8270 <p> 8271 Device implementations MUST include support for one or more forms of data 8272networking. Specifically, device implementations MUST include support for at 8273least one data standard capable of 200 Kbit/sec or greater. Examples of 8274technologies that satisfy this requirement include EDGE, HSPA, EV-DO, 802.11g, 8275Ethernet, Bluetooth PAN, etc. 8276 </p> 8277 <p> 8278 Device implementations where a physical networking standard (such as Ethernet) 8279is the primary data connection SHOULD also include support for at least one 8280common wireless data standard, such as 802.11 (Wi-Fi). 8281 </p> 8282 <p> 8283 Devices MAY implement more than one form of data connectivity. 8284 </p> 8285 <p> 8286 Devices MUST include an IPv6 networking stack and support IPv6 communication 8287using the managed APIs, such as 8288 <code> 8289 java.net.Socket 8290 </code> 8291 and 8292 <code> 8293 java.net.URLConnection 8294 </code>, 8295as well as the native APIs, such as 8296 <code> 8297 AF_INET6 8298 </code> 8299 sockets. The required level of 8300IPv6 support depends on the network type, as follows: 8301 </p> 8302 <ul> 8303 <li> 8304 Devices that support Wi-Fi networks MUST support dual-stack and IPv6-only 8305 operation on Wi-Fi. 8306 </li> 8307 <li> 8308 Devices that support Ethernet networks MUST support dual-stack operation on 8309 Ethernet. 8310 </li> 8311 <li> 8312 Devices that support cellular data SHOULD support IPv6 operation (IPv6-only 8313 and possibly dual-stack) on cellular data. 8314 </li> 8315 <li> 8316 When a device is simultaneously connected to more than one network (e.g., 8317 Wi-Fi and cellular data), it MUST simultaneously meet these requirements on 8318 each network to which it is connected. 8319 </li> 8320 </ul> 8321 <p> 8322 IPv6 MUST be enabled by default. 8323 </p> 8324 <p> 8325 In order to ensure that IPv6 communication is as reliable as IPv4, unicast IPv6 8326packets sent to the device MUST NOT be dropped, even when the screen is not in 8327an active state. Redundant multicast IPv6 packets, such as repeated identical 8328Router Advertisements, MAY be rate-limited in hardware or firmware if doing so 8329is necessary to save power. In such cases, rate-limiting MUST NOT cause the 8330device to lose IPv6 connectivity on any IPv6-compliant network that uses RA 8331lifetimes of at least 180 seconds. 8332 </p> 8333 <p> 8334 IPv6 connectivity MUST be maintained in doze mode. 8335 </p> 8336 <h3 id="7_4_6_sync_settings"> 8337 7.4.6. Sync Settings 8338 </h3> 8339 <p> 8340 Device implementations MUST have the master auto-sync setting on by default so 8341that the method 8342 <a href="http://developer.android.com/reference/android/content/ContentResolver.html">getMasterSyncAutomatically()</a> returns “true”. 8343 </p> 8344 <h3 id="7_4_7_data_saver"> 8345 7.4.7. Data Saver 8346 </h3> 8347 <p> 8348 Device implementations with a metered connection are STRONGLY RECOMMENDED to provide the 8349data saver mode. 8350 </p> 8351 <p> 8352 If a device implementation provides the data saver mode, it: 8353 </p> 8354 <ul> 8355 <li> 8356 <p> 8357 MUST support all the APIs in the 8358 <code> 8359 ConnectivityManager 8360 </code> 8361 class as described in the 8362 <a href="https://developer.android.com/training/basics/network-ops/data-saver.html">SDK documentation</a>. 8363 </p> 8364 </li> 8365 <li> 8366 <p> 8367 MUST provide a user interface in the settings, allowing users to add 8368 applications to or remove applications from the whitelist. 8369 </p> 8370 </li> 8371 </ul> 8372 <p> 8373 Conversely if a device implementation does not provide the data saver mode, it: 8374 </p> 8375 <ul> 8376 <li> 8377 <p> 8378 MUST return the value 8379 <code> 8380 RESTRICT_BACKGROUND_STATUS_DISABLED 8381 </code> 8382 for 8383 <a href="https://developer.android.com/reference/android/net/ConnectivityManager.html#getRestrictBackgroundStatus%28%29"> 8384 <code> 8385 ConnectivityManager.getRestrictBackgroundStatus 8386 </code> 8387 </a> 8388 </p> 8389 </li> 8390 <li> 8391 <p> 8392 MUST not broadcast 8393 <code> 8394 ConnectivityManager.ACTION_RESTRICT_BACKGROUND_CHANGED 8395 </code> 8396 </p> 8397 </li> 8398 <li> 8399 <p> 8400 MUST have an activity that handles the 8401 <code> 8402 Settings.ACTION_IGNORE_BACKGROUND_DATA_RESTRICTIONS_SETTINGS 8403 </code> 8404 intent but MAY implement it as a no-op. 8405 </p> 8406 </li> 8407 </ul> 8408 <h2 id="7_5_cameras"> 8409 7.5. Cameras 8410 </h2> 8411 <p> 8412 Device implementations SHOULD include a rear-facing camera and MAY include a 8413front-facing camera. A rear-facing camera is a camera located on the side of 8414the device opposite the display; that is, it images scenes on the far side of 8415the device, like a traditional camera. A front-facing camera is a camera 8416located on the same side of the device as the display; that is, a camera 8417typically used to image the user, such as for video conferencing and similar 8418applications. 8419 </p> 8420 <p> 8421 If a device implementation includes at least one camera, it MUST be possible for 8422an application to simultaneously allocate 3 RGBA_8888 bitmaps equal to the size 8423of the images produced by the largest-resolution camera sensor on the device, 8424while camera is open for the purpose of basic preview and still capture. 8425 </p> 8426 <h3 id="7_5_1_rear-facing_camera"> 8427 7.5.1. Rear-Facing Camera 8428 </h3> 8429 <p> 8430 Device implementations SHOULD include a rear-facing camera. If a device 8431implementation includes at least one rear-facing camera, it: 8432 </p> 8433 <ul> 8434 <li> 8435 MUST report the feature flag android.hardware.camera and 8436android.hardware.camera.any. 8437 </li> 8438 <li> 8439 MUST have a resolution of at least 2 megapixels. 8440 </li> 8441 <li> 8442 SHOULD have either hardware auto-focus or software auto-focus implemented 8443in the camera driver (transparent to application software). 8444 </li> 8445 <li> 8446 MAY have fixed-focus or EDOF (extended depth of field) hardware. 8447 </li> 8448 <li> 8449 MAY include a flash. If the Camera includes a flash, the flash lamp MUST 8450NOT be lit while an android.hardware.Camera.PreviewCallback instance has been 8451registered on a Camera preview surface, unless the application has explicitly 8452enabled the flash by enabling the FLASH_MODE_AUTO or FLASH_MODE_ON attributes 8453of a Camera.Parameters object. Note that this constraint does not apply to the 8454device’s built-in system camera application, but only to third-party 8455applications using Camera.PreviewCallback. 8456 </li> 8457 </ul> 8458 <h3 id="7_5_2_front-facing_camera"> 8459 7.5.2. Front-Facing Camera 8460 </h3> 8461 <p> 8462 Device implementations MAY include a front-facing camera. If a device 8463implementation includes at least one front-facing camera, it: 8464 </p> 8465 <ul> 8466 <li> 8467 MUST report the feature flag android.hardware.camera.any and 8468android.hardware.camera.front. 8469 </li> 8470 <li> 8471 MUST have a resolution of at least VGA (640x480 pixels). 8472 </li> 8473 <li> 8474 MUST NOT use a front-facing camera as the default for the Camera API. The 8475camera API in Android has specific support for front-facing cameras and device 8476implementations MUST NOT configure the API to to treat a front-facing camera as 8477the default rear-facing camera, even if it is the only camera on the device. 8478 </li> 8479 <li> 8480 MAY include features (such as auto-focus, flash, etc.) available to 8481rear-facing cameras as described in 8482 <a href="#7_5_1_rear-facing_camera">section 7.5.1</a>. 8483 </li> 8484 <li> 8485 MUST horizontally reflect (i.e. mirror) the stream displayed by an app in a 8486CameraPreview, as follows: 8487 <ul> 8488 <li> 8489 If the device implementation is capable of being rotated by user (such 8490as automatically via an accelerometer or manually via user input), the camera 8491preview MUST be mirrored horizontally relative to the device’s current 8492orientation. 8493 </li> 8494 <li> 8495 If the current application has explicitly requested that the Camera 8496display be rotated via a call to the 8497 <a href="http://developer.android.com/reference/android/hardware/Camera.html#setDisplayOrientation(int)">android.hardware.Camera.setDisplayOrientation()</a> method, the camera preview MUST be mirrored horizontally relative to the 8498orientation specified by the application. 8499 </li> 8500 <li> 8501 Otherwise, the preview MUST be mirrored along the device’s default 8502horizontal axis. 8503 </li> 8504 </ul> 8505 </li> 8506 <li> 8507 MUST mirror the image displayed by the postview in the same manner as the 8508camera preview image stream. If the device implementation does not support 8509postview, this requirement obviously does not apply. 8510 </li> 8511 <li> 8512 MUST NOT mirror the final captured still image or video streams returned to 8513application callbacks or committed to media storage. 8514 </li> 8515 </ul> 8516 <h3 id="7_5_3_external_camera"> 8517 7.5.3. External Camera 8518 </h3> 8519 <p> 8520 Device implementations MAY include support for an external camera that is not 8521necessarily always connected. If a device includes support for an external camera, 8522it: 8523 </p> 8524 <ul> 8525 <li> 8526 MUST declare the platform feature flag 8527 <code> 8528 android.hardware.camera.external 8529 </code> 8530 and 8531 <code> 8532 android.hardware camera.any 8533 </code>. 8534 </li> 8535 <li> 8536 MAY support multiple cameras. 8537 </li> 8538 <li> 8539 MUST support USB Video Class (UVC 1.0 or higher) if the external camera 8540 connects through the USB port. 8541 </li> 8542 <li> 8543 SHOULD support video compressions such as MJPEG to enable transfer of 8544 high-quality unencoded streams (i.e. raw or independently compressed picture 8545 streams). 8546 </li> 8547 <li> 8548 MAY support camera-based video encoding. If supported, a simultaneous 8549 unencoded / MJPEG stream (QVGA or greater resolution) MUST be accessible to 8550 the device implementation. 8551 </li> 8552 </ul> 8553 <h3 id="7_5_4_camera_api_behavior"> 8554 7.5.4. Camera API Behavior 8555 </h3> 8556 <p> 8557 Android includes two API packages to access the camera, the newer 8558android.hardware.camera2 API expose lower-level camera control to the app, 8559including efficient zero-copy burst/streaming flows and per-frame controls of 8560exposure, gain, white balance gains, color conversion, denoising, sharpening, 8561and more. 8562 </p> 8563 <p> 8564 The older API package, android.hardware.Camera, is marked as deprecated in 8565Android 5.0 but as it should still be available for apps to use Android device 8566implementations MUST ensure the continued support of the API as described in 8567this section and in the Android SDK. 8568 </p> 8569 <p> 8570 Device implementations MUST implement the following behaviors for the 8571camera-related APIs, for all available cameras: 8572 </p> 8573 <ul> 8574 <li> 8575 If an application has never called 8576android.hardware.Camera.Parameters.setPreviewFormat(int), then the device MUST 8577use android.hardware.PixelFormat.YCbCr_420_SP for preview data provided to 8578application callbacks. 8579 </li> 8580 <li> 8581 If an application registers an android.hardware.Camera.PreviewCallback 8582instance and the system calls the onPreviewFrame() method when the preview 8583format is YCbCr_420_SP, the data in the byte[] passed into onPreviewFrame() 8584must further be in the NV21 encoding format. That is, NV21 MUST be the default. 8585 </li> 8586 <li> 8587 For android.hardware.Camera, device implementations MUST support the YV12 8588format (as denoted by the android.graphics.ImageFormat.YV12 constant) for 8589camera previews for both front- and rear-facing cameras. (The hardware video 8590encoder and camera may use any native pixel format, but the device 8591implementation MUST support conversion to YV12.) 8592 </li> 8593 <li> 8594 For android.hardware.camera2, device implementations must support the 8595android.hardware.ImageFormat.YUV_420_888 and android.hardware.ImageFormat.JPEG 8596formats as outputs through the android.media.ImageReader API. 8597 </li> 8598 </ul> 8599 <p> 8600 Device implementations MUST still implement the full 8601 <a href="http://developer.android.com/reference/android/hardware/Camera.html"> 8602 Camera 8603API 8604 </a> 8605 included in the Android SDK documentation, regardless of whether the device 8606includes hardware autofocus or other capabilities. For instance, cameras that 8607lack autofocus MUST still call any registered 8608android.hardware.Camera.AutoFocusCallback instances (even though this has no 8609relevance to a non-autofocus camera.) Note that this does apply to front-facing 8610cameras; for instance, even though most front-facing cameras do not support 8611autofocus, the API callbacks must still be “faked” as described. 8612 </p> 8613 <p> 8614 Device implementations MUST recognize and honor each parameter name defined as 8615a constant on the 8616 <a href="http://developer.android.com/reference/android/hardware/Camera.Parameters.html">android.hardware.Camera.Parameters</a> class, if the underlying hardware supports the feature. If the device hardware 8617does not support a feature, the API must behave as documented. Conversely, 8618device implementations MUST NOT honor or recognize string constants passed to 8619the android.hardware.Camera.setParameters() method other than those documented 8620as constants on the android.hardware.Camera.Parameters. That is, device 8621implementations MUST support all standard Camera parameters if the hardware 8622allows, and MUST NOT support custom Camera parameter types. For instance, 8623device implementations that support image capture using high dynamic range 8624(HDR) imaging techniques MUST support camera parameter Camera.SCENE_MODE_HDR. 8625 </p> 8626 <p> 8627 Because not all device implementations can fully support all the features of 8628the android.hardware.camera2 API, device implementations MUST report the proper 8629level of support with the 8630 <a href="https://developer.android.com/reference/android/hardware/camera2/CameraCharacteristics.html#INFO_SUPPORTED_HARDWARE_LEVEL">android.info.supportedHardwareLevel</a> property as described in the Android SDK and report the appropriate 8631 <a href="http://source.android.com/devices/camera/versioning.html"> 8632 framework feature flags</a>. 8633 </p> 8634 <p> 8635 Device implementations MUST also declare its Individual camera capabilities of 8636android.hardware.camera2 via the android.request.availableCapabilities property 8637and declare the appropriate 8638 <a href="http://source.android.com/devices/camera/versioning.html"> 8639 feature flags</a>; a device must 8640define the feature flag if any of its attached camera devices supports the 8641feature. 8642 </p> 8643 <p> 8644 Device implementations MUST broadcast the Camera.ACTION_NEW_PICTURE intent 8645whenever a new picture is taken by the camera and the entry of the picture has 8646been added to the media store. 8647 </p> 8648 <p> 8649 Device implementations MUST broadcast the Camera.ACTION_NEW_VIDEO intent 8650whenever a new video is recorded by the camera and the entry of the picture has 8651been added to the media store. 8652 </p> 8653 <h3 id="7_5_5_camera_orientation"> 8654 7.5.5. Camera Orientation 8655 </h3> 8656 <p> 8657 Both front- and rear-facing cameras, if present, MUST be oriented so that the 8658long dimension of the camera aligns with the screen’s long dimension. That is, 8659when the device is held in the landscape orientation, cameras MUST capture 8660images in the landscape orientation. This applies regardless of the device’s 8661natural orientation; that is, it applies to landscape-primary devices as well 8662as portrait-primary devices. 8663 </p> 8664 <h2 id="7_6_memory_and_storage"> 8665 7.6. Memory and Storage 8666 </h2> 8667 <h3 id="7_6_1_minimum_memory_and_storage"> 8668 7.6.1. Minimum Memory and Storage 8669 </h3> 8670 <div class="note"> 8671 Android Television devices MUST have at least 4GB of non-volatile storage 8672available for application private data. 8673 </div> 8674 <p> 8675 The memory available to the kernel and userspace on device implementations MUST 8676be at least equal or larger than the minimum values specified by the following 8677table. (See 8678 <a href="#7_1_1_screen_configuration">section 7.1.1</a> for screen size and 8679density definitions.) 8680 </p> 8681 <table> 8682 <tr> 8683 <th> 8684 Density and screen size 8685 </th> 8686 <th> 8687 32-bit device 8688 </th> 8689 <th> 8690 64-bit device 8691 </th> 8692 </tr> 8693 <tr> 8694 <td> 8695 Android Watch devices (due to smaller screens) 8696 </td> 8697 <td> 8698 416MB 8699 </td> 8700 <td> 8701 Not applicable 8702 </td> 8703 </tr> 8704 <tr> 8705 <td> 8706 <ul> 8707 <li class="table_list"> 8708 280dpi or lower on small/normal screens 8709 </li> 8710 <li class="table_list"> 8711 mdpi or lower on large screens 8712 </li> 8713 <li class="table_list"> 8714 ldpi or lower on extra large screens 8715 </li> 8716 </ul> 8717 </td> 8718 <td> 8719 512MB 8720 </td> 8721 <td> 8722 816MB 8723 </td> 8724 </tr> 8725 <tr> 8726 <td> 8727 <ul> 8728 <li class="table_list"> 8729 xhdpi or higher on small/normal screens 8730 </li> 8731 <li class="table_list"> 8732 hdpi or higher on large screens 8733 </li> 8734 <li class="table_list"> 8735 mdpi or higher on extra large screens 8736 </li> 8737 </ul> 8738 </td> 8739 <td> 8740 608MB 8741 </td> 8742 <td> 8743 944MB 8744 </td> 8745 </tr> 8746 <tr> 8747 <td> 8748 <ul> 8749 <li class="table_list"> 8750 400dpi or higher on small/normal screens 8751 </li> 8752 <li class="table_list"> 8753 xhdpi or higher on large screens 8754 </li> 8755 <li class="table_list"> 8756 tvdpi or higher on extra large screens 8757 </li> 8758 </ul> 8759 </td> 8760 <td> 8761 896MB 8762 </td> 8763 <td> 8764 1280MB 8765 </td> 8766 </tr> 8767 <tr> 8768 <td> 8769 <ul> 8770 <li class="table_list"> 8771 560dpi or higher on small/normal screens 8772 </li> 8773 <li class="table_list"> 8774 400dpi or higher on large screens 8775 </li> 8776 <li class="table_list"> 8777 xhdpi or higher on extra large screens 8778 </li> 8779 </ul> 8780 </td> 8781 <td> 8782 1344MB 8783 </td> 8784 <td> 8785 1824MB 8786 </td> 8787 </tr> 8788 </table> 8789 <p> 8790 The minimum memory values MUST be in addition to any memory space already 8791dedicated to hardware components such as radio, video, and so on that is not 8792under the kernel’s control. 8793 </p> 8794 <p> 8795 Device implementations with less than 512MB of memory available to the kernel 8796and userspace, unless an Android Watch, MUST return the value "true" for 8797ActivityManager.isLowRamDevice(). 8798 </p> 8799 <p> 8800 Android Television devices MUST have at least 4GB and other device 8801implementations MUST have at least 3GB of non-volatile storage available for 8802application private data. That is, the /data partition MUST be at least 4GB for 8803Android Television devices and at least 3GB for other device implementations. 8804Device implementations that run Android are 8805 <strong> 8806 STRONGLY RECOMMENDED 8807 </strong> 8808 to have at 8809least 4GB of non-volatile storage for application private data so they will be 8810able to upgrade to the future platform releases. 8811 </p> 8812 <p> 8813 The Android APIs include a 8814 <a href="http://developer.android.com/reference/android/app/DownloadManager.html"> 8815 Download Manager</a> that applications MAY use to download data files. The device implementation of 8816the Download Manager MUST be capable of downloading individual files of at 8817least 100MB in size to the default “cache” location. 8818 </p> 8819 <h3 id="7_6_2_application_shared_storage"> 8820 7.6.2. Application Shared Storage 8821 </h3> 8822 <p> 8823 Device implementations MUST offer shared storage for applications also often 8824referred as “shared external storage”. 8825 </p> 8826 <p> 8827 Device implementations MUST be configured with shared storage mounted by 8828default, “out of the box”. If the shared storage is not mounted on the 8829Linuxpath /sdcard, then the device MUST include a Linux symbolic link from 8830/sdcard to the actual mount point. 8831 </p> 8832 <p> 8833 Device implementations MAY have hardware for user-accessible removable storage, 8834such as a Secure Digital (SD) card slot. If this slot is used to satisfy the 8835shared storage requirement, the device implementation: 8836 </p> 8837 <ul> 8838 <li> 8839 MUST implement a toast or pop-up user interface warning the user when there 8840is no SD card. 8841 </li> 8842 <li> 8843 MUST include a FAT-formatted SD card 1GB in size or larger OR show on the 8844box and other material available at time of purchase that the SD card has to be 8845separately purchased. 8846 </li> 8847 <li> 8848 MUST mount the SD card by default. 8849 </li> 8850 </ul> 8851 <p> 8852 Alternatively, device implementations MAY allocate internal (non-removable) 8853storage as shared storage for apps as included in the upstream Android Open 8854Source Project; device implementations SHOULD use this configuration and 8855software implementation. If a device implementation uses internal 8856(non-removable) storage to satisfy the shared storage requirement, while that 8857storage MAY share space with the application private data, it MUST be at least 88581GB in size and mounted on /sdcard (or /sdcard MUST be a symbolic link to the 8859physical location if it is mounted elsewhere). 8860 </p> 8861 <p> 8862 Device implementations MUST enforce as documented the 8863android.permission.WRITE_EXTERNAL_STORAGE permission on this shared storage. 8864Shared storage MUST otherwise be writable by any application that obtains that 8865permission. 8866 </p> 8867 <p> 8868 Device implementations that include multiple shared storage paths (such as both 8869an SD card slot and shared internal storage) MUST allow only pre-installed & 8870privileged Android applications with the WRITE_EXTERNAL_STORAGE permission to 8871write to the secondary external storage, except when writing to their 8872package-specific directories or within the 8873 <code> 8874 URI 8875 </code> 8876 returned by firing the 8877 <code> 8878 ACTION_OPEN_DOCUMENT_TREE 8879 </code> 8880 intent. 8881 </p> 8882 <p> 8883 However, device implementations SHOULD expose content from both storage paths 8884transparently through Android’s media scanner service and 8885android.provider.MediaStore. 8886 </p> 8887 <p> 8888 Regardless of the form of shared storage used, if the device implementation has 8889a USB port with USB peripheral mode support, it MUST provide some mechanism to 8890access the contents of shared storage from a host computer. Device 8891implementations MAY use USB mass storage, but SHOULD use Media Transfer 8892Protocol to satisfy this requirement. If the device implementation supports 8893Media Transfer Protocol, it: 8894 </p> 8895 <ul> 8896 <li> 8897 SHOULD be compatible with the reference Android MTP host, 8898 <a href="http://www.android.com/filetransfer"> 8899 Android File 8900Transfer 8901 </a> 8902 . 8903 </li> 8904 <li> 8905 SHOULD report a USB device class of 0x00. 8906 </li> 8907 <li> 8908 SHOULD report a USB interface name of 'MTP'. 8909 </li> 8910 </ul> 8911 <h3 id="7_6_3_adoptable_storage"> 8912 7.6.3. Adoptable Storage 8913 </h3> 8914 <p> 8915 Device implementations are STRONGLY RECOMMENDED to implement 8916 <a href="http://source.android.com/devices/storage/adoptable.html"> 8917 adoptable storage</a> if the 8918removable storage device port is in a long-term stable location, such as within 8919the battery compartment or other protective cover. 8920 </p> 8921 <p> 8922 Device implementations such as a television, MAY enable adoption through USB 8923ports as the device is expected to be static and not mobile. But for other 8924device implementations that are mobile in nature, it is STRONGLY RECOMMENDED to 8925implement the adoptable storage in a long-term stable location, since 8926accidentally disconnecting them can cause data loss/corruption. 8927 </p> 8928 <h2 id="7_7_usb"> 8929 7.7. USB 8930 </h2> 8931 <p> 8932 Device implementations SHOULD support USB peripheral mode and SHOULD support USB 8933host mode. 8934 </p> 8935 <h3 id="7_7_1_usb_peripheral_mode"> 8936 7.7.1. USB peripheral mode 8937 </h3> 8938 <p> 8939 If a device implementation includes a USB port supporting peripheral mode: 8940 </p> 8941 <ul> 8942 <li> 8943 The port MUST be connectable to a USB host that has a standard type-A or 8944 type-C USB port. 8945 </li> 8946 <li> 8947 The port SHOULD use micro-B, micro-AB or Type-C USB form factor. Existing 8948 and new Android devices are 8949 <strong> 8950 STRONGLY RECOMMENDED to meet these 8951 requirements 8952 </strong> 8953 so they will be able to upgrade to the future platform 8954 releases. 8955 </li> 8956 <li> 8957 The port SHOULD be located on the bottom of the device 8958 (according to natural orientation) or enable software screen rotation for 8959 all apps (including home screen), so that the display draws correctly when 8960 the device is oriented with the port at bottom. Existing and new Android 8961 devices are 8962 <strong> 8963 STRONGLY RECOMMENDED to meet these requirements 8964 </strong> 8965 so they will 8966 be able to upgrade to future platform releases. 8967 </li> 8968 <li> 8969 It MUST allow a USB host connected with the Android device to access the 8970 contents of the shared storage volume using either USB mass storage or Media 8971 Transfer Protocol. 8972 </li> 8973 <li> 8974 It SHOULD implement the Android Open Accessory (AOA) API and specification 8975 as documented in the Android SDK documentation, and if it is an Android 8976 Handheld device it MUST implement the AOA API. Device implementations 8977 implementing the AOA specification: 8978 <ul> 8979 <li> 8980 MUST declare support for the hardware feature 8981 <a href="http://developer.android.com/guide/topics/connectivity/usb/accessory.html">android.hardware.usb.accessory</a>. 8982 </li> 8983 <li> 8984 MUST implement the 8985 <a href="http://developer.android.com/reference/android/hardware/usb/UsbConstants.html#USB_CLASS_AUDIO"> 8986 USB audio 8987 class 8988 </a> 8989 as 8990 documented in the Android SDK documentation. 8991 </li> 8992 <li> 8993 The USB mass storage class MUST include the string "android" at the end 8994 of the interface description 8995 <code> 8996 iInterface 8997 </code> 8998 string of the USB mass storage 8999 </li> 9000 </ul> 9001 </li> 9002 <li> 9003 It SHOULD implement support to draw 1.5 A current during HS chirp and 9004 traffic as specified in the 9005 <a href="http://www.usb.org/developers/docs/devclass_docs/BCv1.2_070312.zip"> 9006 USB Battery Charging specification, revision 9007 1.2 9008 </a> 9009 . 9010 Existing and new Android devices are 9011 <strong> 9012 STRONGLY RECOMMENDED to meet these 9013 requirements 9014 </strong> 9015 so they will be able to upgrade to the future platform 9016 releases. 9017 </li> 9018 <li> 9019 Type-C devices MUST detect 1.5A and 3.0A chargers per the Type-C resistor 9020 standard and it must detect changes in the advertisement. 9021 </li> 9022 <li> 9023 Type-C devices also supporting USB host mode are STRONGLY RECOMMENDED to 9024 support Power Delivery for data and power role swapping. 9025 </li> 9026 <li> 9027 Type-C devices SHOULD support Power Delivery for high-voltage charging and 9028 support for Alternate Modes such as display out. 9029 </li> 9030 <li> 9031 The value of iSerialNumber in USB standard device descriptor MUST be equal 9032 to the value of android.os.Build.SERIAL. 9033 </li> 9034 <li> 9035 Type-C devices are STRONGLY RECOMMENDED to not support proprietary charging 9036 methods that modify Vbus voltage beyond default levels, or alter sink/source 9037 roles as such may result in interoperability issues with the chargers or 9038 devices that support the standard USB Power Delivery methods. While this is 9039 called out as "STRONGLY RECOMMENDED", in future Android versions we might 9040 REQUIRE all type-C devices to support full interoperability with standard 9041 type-C chargers. 9042 </li> 9043 </ul> 9044 <h3 id="7_7_2_usb_host_mode"> 9045 7.7.2. USB host mode 9046 </h3> 9047 <p> 9048 If a device implementation includes a USB port supporting host mode, it: 9049 </p> 9050 <ul> 9051 <li> 9052 SHOULD use a type-C USB port, if the device implementation supports USB 3.1. 9053 </li> 9054 <li> 9055 MAY use a non-standard port form factor, but if so MUST ship with a cable or 9056 cables adapting the port to a standard type-A or type-C USB port. 9057 </li> 9058 <li> 9059 MAY use a micro-AB USB port, but if so SHOULD ship with a cable or cables adapting the port to a standard type-A or type-C USB port. 9060 </li> 9061 <li> 9062 is 9063 <strong> 9064 STRONGLY RECOMMENDED 9065 </strong> 9066 to implement the 9067 <a href="http://developer.android.com/reference/android/hardware/usb/UsbConstants.html#USB_CLASS_AUDIO"> 9068 USB audio 9069 class 9070 </a> 9071 as documented in the Android SDK documentation. 9072 </li> 9073 <li> 9074 MUST implement the Android USB host API as documented in the Android SDK, 9075 and MUST declare support for the hardware feature 9076 <a href="http://developer.android.com/guide/topics/connectivity/usb/host.html">android.hardware.usb.host</a>. 9077 </li> 9078 <li> 9079 SHOULD support the Charging Downstream Port output current range of 1.5 A ~ 9080 5 A as specified in the 9081 <a href="http://www.usb.org/developers/docs/devclass_docs/BCv1.2_070312.zip">USB Battery Charging specifications, revision 1.2</a>. 9082 </li> 9083 <li> 9084 USB Type-C devices are STRONGLY RECOMMENDED to support DisplayPort, SHOULD 9085 support USB SuperSpeed Data Rates, and are STRONGLY RECOMMENDED to support 9086 Power Delivery for data and power role swapping. 9087 </li> 9088 <li> 9089 Devices with any type-A or type-AB ports MUST NOT ship with an adapter converting 9090 from this port to a type-C receptacle. 9091 </li> 9092 <li> 9093 MUST recognize any remotely connected MTP (Media Transfer Protocol) devices 9094 and make their contents accessible through the 9095 <code> 9096 ACTION_GET_CONTENT 9097 </code>, 9098 <code> 9099 ACTION_OPEN_DOCUMENT 9100 </code>, and 9101 <code> 9102 ACTION_CREATE_DOCUMENT 9103 </code> 9104 intents, if the Storage Access 9105 Framework (SAF) is supported. 9106 </li> 9107 <li> 9108 MUST, if using a Type-C USB port and including support for peripheral mode, 9109 implement Dual Role Port functionality as defined by the USB Type-C 9110 specification (section 4.5.1.3.3). 9111 </li> 9112 <li> 9113 SHOULD, if the Dual Role Port functionality is supported, implement the 9114 Try.* model that is most appropriate for the device form factor. For 9115 example a handheld device SHOULD implement the Try.SNK model. 9116 </li> 9117 </ul> 9118 <h2 id="7_8_audio"> 9119 7.8. Audio 9120 </h2> 9121 <h3 id="7_8_1_microphone"> 9122 7.8.1. Microphone 9123 </h3> 9124 <div class="note"> 9125 Android Handheld, Watch, and Automotive implementations MUST include a 9126microphone. 9127 </div> 9128 <p> 9129 Device implementations MAY omit a microphone. However, if a device 9130implementation omits a microphone, it MUST NOT report the 9131android.hardware.microphone feature constant, and MUST implement the audio 9132recording API at least as no-ops, per 9133 <a href="#7_hardware_compatibility">section 7</a>. 9134Conversely, device implementations that do possess a microphone: 9135 </p> 9136 <ul> 9137 <li> 9138 MUST report the android.hardware.microphone feature constant. 9139 </li> 9140 <li> 9141 MUST meet the audio recording requirements in 9142 <a href="#5_4_audio_recording">section 5.4</a>. 9143 </li> 9144 <li> 9145 MUST meet the audio latency requirements in 9146 <a href="#5_6_audio_latency">section 5.6</a>. 9147 </li> 9148 <li> 9149 STRONGLY RECOMMENDED to support near-ultrasound recording as described in 9150 <a href="#7_8_3_near_ultrasound">section 7.8.3</a>. 9151 </li> 9152 </ul> 9153 <h3 id="7_8_2_audio_output"> 9154 7.8.2. Audio Output 9155 </h3> 9156 <div class="note"> 9157 Android Watch devices MAY include an audio output. 9158 </div> 9159 <p> 9160 Device implementations including a speaker or with an audio/multimedia output 9161port for an audio output peripheral as a headset or an external speaker: 9162 </p> 9163 <ul> 9164 <li> 9165 MUST report the android.hardware.audio.output feature constant. 9166 </li> 9167 <li> 9168 MUST meet the audio playback requirements in 9169 <a href="#5_5_audio_playback">section 5.5</a>. 9170 </li> 9171 <li> 9172 MUST meet the audio latency requirements in 9173 <a href="#5_6_audio_latency">section 5.6</a>. 9174 </li> 9175 <li> 9176 STRONGLY RECOMMENDED to support near-ultrasound playback as described in 9177 <a href="#7_8_3_near_ultrasound">section 7.8.3</a>. 9178 </li> 9179 </ul> 9180 <p> 9181 Conversely, if a device implementation does not include a speaker or audio 9182output port, it MUST NOT report the android.hardware.audio output feature, and 9183MUST implement the Audio Output related APIs as no-ops at least. 9184 </p> 9185 <p> 9186 Android Watch device implementation MAY but SHOULD NOT have audio output, but 9187other types of Android device implementations MUST have an audio output and 9188declare android.hardware.audio.output. 9189 </p> 9190 <h4 id="7_8_2_1_analog_audio_ports"> 9191 7.8.2.1. Analog Audio Ports 9192 </h4> 9193 <p> 9194 In order to be compatible with the 9195 <a href="http://source.android.com/accessories/headset-spec.html"> 9196 headsets and other audio accessories</a> using the 91973.5mm audio plug across the Android ecosystem, if a device implementation 9198includes one or more analog audio ports, at least one of the audio port(s) 9199SHOULD be a 4 conductor 3.5mm audio jack. If a device implementation has a 4 9200conductor 3.5mm audio jack, it: 9201 </p> 9202 <ul> 9203 <li> 9204 MUST support audio playback to stereo headphones and stereo headsets with a 9205microphone, and SHOULD support audio recording from stereo headsets with a 9206microphone. 9207 </li> 9208 <li> 9209 MUST support TRRS audio plugs with the CTIA pin-out order, and SHOULD 9210support audio plugs with the OMTP pin-out order. 9211 </li> 9212 <li> 9213 MUST support the detection of microphone on the plugged in audio accessory, 9214if the device implementation supports a microphone, and broadcast the 9215android.intent.action.HEADSET_PLUG with the extra value microphone set as 1. 9216 </li> 9217 <li> 9218 MUST support the detection and mapping to the keycodes for the following 92193 ranges of equivalent impedance between the microphone and ground conductors 9220on the audio plug: 9221 <ul> 9222 <li> 9223 <strong> 9224 70 ohm or less 9225 </strong> 9226 : KEYCODE_HEADSETHOOK 9227 </li> 9228 <li> 9229 <strong> 9230 210-290 Ohm 9231 </strong> 9232 : KEYCODE_VOLUME_UP 9233 </li> 9234 <li> 9235 <strong> 9236 360-680 Ohm 9237 </strong> 9238 : KEYCODE_VOLUME_DOWN 9239 </li> 9240 </ul> 9241 </li> 9242 <li> 9243 STRONGLY RECOMMENDED to detect and map to the keycode for the following 9244range of equivalent impedance between the microphone and ground conductors 9245on the audio plug: 9246 <ul> 9247 <li> 9248 <strong> 9249 110-180 Ohm: 9250 </strong> 9251 KEYCODE_VOICE_ASSIST 9252 </li> 9253 </ul> 9254 </li> 9255 <li> 9256 MUST trigger ACTION_HEADSET_PLUG upon a plug insert, but only after all 9257contacts on plug are touching their relevant segments on the jack. 9258 </li> 9259 <li> 9260 MUST be capable of driving at least 150mV ± 10% of output voltage on a 32 9261Ohm speaker impedance. 9262 </li> 9263 <li> 9264 MUST have a microphone bias voltage between 1.8V ~ 2.9V. 9265 </li> 9266 </ul> 9267 <h3 id="7_8_3_near-ultrasound"> 9268 7.8.3. Near-Ultrasound 9269 </h3> 9270 <p> 9271 Near-Ultrasound audio is the 18.5 kHz to 20 kHz band. Device implementations 9272MUST correctly report the support of near-ultrasound audio capability via the 9273 <a href="http://developer.android.com/reference/android/media/AudioManager.html#getProperty(java.lang.String)">AudioManager.getProperty</a> API as follows: 9274 </p> 9275 <ul> 9276 <li> 9277 If 9278 <a href="http://developer.android.com/reference/android/media/AudioManager.html#PROPERTY_SUPPORT_MIC_NEAR_ULTRASOUND">PROPERTY_SUPPORT_MIC_NEAR_ULTRASOUND</a> is "true", then the following requirements must be met by the 9279VOICE_RECOGNITION and UNPROCESSED audio sources: 9280 <ul> 9281 <li> 9282 The microphone's mean power response in the 18.5 kHz to 20 kHz band 9283MUST be no more than 15 dB below the response at 2 kHz. 9284 </li> 9285 <li> 9286 The microphone's unweighted signal to noise ratio over 18.5 kHz to 20 kHz 9287for a 19 kHz tone at -26 dBFS MUST be no lower than 50 dB. 9288 </li> 9289 </ul> 9290 </li> 9291 <li> 9292 If 9293 <a href="http://developer.android.com/reference/android/media/AudioManager.html#PROPERTY_SUPPORT_SPEAKER_NEAR_ULTRASOUND">PROPERTY_SUPPORT_SPEAKER_NEAR_ULTRASOUND</a> is "true", then the speaker's mean response in 18.5 kHz - 20 kHz MUST be no 9294lower than 40 dB below the response at 2 kHz. 9295 </li> 9296 </ul> 9297 <h2 id="7_9_virtual_reality"> 9298 7.9. Virtual Reality 9299 </h2> 9300 <p> 9301 Android includes APIs and facilities to build "Virtual Reality" (VR) applications including high 9302quality mobile VR experiences. Device implementations MUST properly implement these APIs and 9303behaviors, as detailed in this section. 9304 </p> 9305 <h3 id="7_9_1_virtual_reality_mode"> 9306 7.9.1. Virtual Reality Mode 9307 </h3> 9308 <p> 9309 Android handheld device implementations that support a mode for VR applications that handles 9310stereoscopic rendering of notifications and disable monocular system UI components while a VR 9311application has user focus MUST declare 9312 <code> 9313 android.software.vr.mode 9314 </code> 9315 feature. Devices declaring this 9316feature MUST include an application implementing 9317 <code> 9318 android.service.vr.VrListenerService 9319 </code> 9320 that can be 9321enabled by VR applications via 9322 <code> 9323 android.app.Activity#setVrModeEnabled 9324 </code>. 9325 </p> 9326 <h3 id="7_9_2_virtual_reality_high_performance"> 9327 7.9.2. Virtual Reality High Performance 9328 </h3> 9329 <p> 9330 Android handheld device implementations MUST identify the support of high performance virtual 9331reality for longer user periods through the 9332 <code> 9333 android.hardware.vr.high_performance 9334 </code> 9335 feature flag and 9336meet the following requirements. 9337 </p> 9338 <ul> 9339 <li> 9340 Device implementations MUST have at least 2 physical cores. 9341 </li> 9342 <li> 9343 Device implementations MUST declare android.software.vr.mode feature. 9344 </li> 9345 <li> 9346 Device implementations MUST provide an exclusive core to the foreground application and MUST 9347 support the Process.getExclusiveCores API to return the numbers of the cpu cores that are 9348 exclusive to the top foreground application. This core MUST not allow any other userspace 9349 processes to run on it (except device drivers used by the application), but MAY allow some 9350 kernel processes to run as necessary. 9351 </li> 9352 <li> 9353 Device implementations MUST support sustained performance mode. 9354 </li> 9355 <li> 9356 Device implementations MUST support OpenGL ES 3.2. 9357 </li> 9358 <li> 9359 Device implementations MUST support Vulkan Hardware Level 0 and SHOULD support 9360 Vulkan Hardware Level 1. 9361 </li> 9362 <li> 9363 Device implementations MUST implement EGL_KHR_mutable_render_buffer and 9364 EGL_ANDROID_front_buffer_auto_refresh, EGL_ANDROID_create_native_client_buffer, 9365 EGL_KHR_fence_sync and EGL_KHR_wait_sync so that they may be used for Shared Buffer Mode, and 9366 expose the extensions in the list of available EGL extensions. 9367 </li> 9368 <li> 9369 The GPU and display MUST be able to synchronize access to the shared front buffer such that 9370 alternating-eye rendering of VR content at 60fps with two render contexts will be displayed with 9371 no visible tearing artifacts. 9372 </li> 9373 <li> 9374 Device implementations MUST implement EGL_IMG_context_priority, and expose the extension in the 9375 list of available EGL extensions. 9376 </li> 9377 <li> 9378 Device implementations MUST implement GL_EXT_multisampled_render_to_texture, GL_OVR_multiview, 9379 GL_OVR_multiview2 and GL_OVR_multiview_multisampled_render_to_texture, and expose the extensions 9380 in the list of available GL extensions. 9381 </li> 9382 <li> 9383 Device implementations MUST implement EGL_EXT_protected_content and GL_EXT_protected_textures so 9384 that it may be used for Secure Texture Video Playback, and expose the extensions in the list of 9385 available EGL and GL extensions. 9386 </li> 9387 <li> 9388 Device implementations MUST support H.264 decoding at least 3840x2160@30fps-40Mbps (equivalent 9389 to 4 instances of 1920x1080@30fps-10Mbps or 2 instances of 1920x1080@60fps-20Mbps). 9390 </li> 9391 <li> 9392 Device implementations MUST support HEVC and VP9, MUST be capable to decode at least 9393 1920x1080@30fps-10Mbps and SHOULD be capable to decode 3840x2160@30fps-20Mbps (equivalent to 9394 4 instances of 1920x1080@30fps-5Mbps). 9395 </li> 9396 <li> 9397 The device implementations are STRONGLY RECOMMENDED to support 9398 android.hardware.sensor.hifi_sensors feature and MUST meet the gyroscope, accelerometer, and 9399 magnetometer related requirements for android.hardware.hifi_sensors. 9400 </li> 9401 <li> 9402 Device implementations MUST support HardwarePropertiesManager.getDeviceTemperatures API and 9403 return accurate values for skin temperature. 9404 </li> 9405 <li> 9406 The device implementation MUST have an embedded screen, and its resolution MUST be at least be 9407 FullHD(1080p) and STRONGLY RECOMMENDED TO BE be QuadHD (1440p) or higher. 9408 </li> 9409 <li> 9410 The display MUST measure between 4.7" and 6" diagonal. 9411 </li> 9412 <li> 9413 The display MUST update at least 60 Hz while in VR Mode. 9414 </li> 9415 <li> 9416 The display latency on Gray-to-Gray, White-to-Black, and Black-to-White switching time MUST 9417 be ≤ 3 ms. 9418 </li> 9419 <li> 9420 The display MUST support a low-persistence mode with ≤5 ms persistence,persistence being 9421 defined as the amount of time for which a pixel is emitting light. 9422 </li> 9423 <li> 9424 Device implementations MUST support Bluetooth 4.2 and Bluetooth LE Data Length Extension 9425 <a href="#7_4_3_bluetooth">section 7.4.3</a>. 9426 </li> 9427 </ul> 9428 <h1 id="8_performance_and_power"> 9429 8. Performance and Power 9430 </h1> 9431 <p> 9432 Some minimum performance and power criteria are critical to the user experience 9433and impact the baseline assumptions developers would have when developing an 9434app. Android Watch devices SHOULD and other type of device implementations MUST 9435meet the following criteria. 9436 </p> 9437 <h2 id="8_1_user_experience_consistency"> 9438 8.1. User Experience Consistency 9439 </h2> 9440 <p> 9441 Device implementations MUST provide a smooth user interface by ensuring a 9442consistent frame rate and response times for applications and games. Device 9443implementations MUST meet the following requirements: 9444 </p> 9445 <ul> 9446 <li> 9447 <strong> 9448 Consistent frame latency 9449 </strong> 9450 . Inconsistent frame latency or a delay to 9451render frames MUST NOT happen more often than 5 frames in a second, and SHOULD 9452be below 1 frames in a second. 9453 </li> 9454 <li> 9455 <strong> 9456 User interface latency 9457 </strong> 9458 . Device implementations MUST ensure low latency 9459user experience by scrolling a list of 10K list entries as defined by the 9460Android Compatibility Test Suite (CTS) in less than 36 secs. 9461 </li> 9462 <li> 9463 <strong> 9464 Task switching 9465 </strong> 9466 . When multiple applications have been launched, 9467re-launching an already-running application after it has been launched MUST 9468take less than 1 second. 9469 </li> 9470 </ul> 9471 <h2 id="8_2_file_i/o_access_performance"> 9472 8.2. File I/O Access Performance 9473 </h2> 9474 <p> 9475 Device implementations MUST ensure internal storage file access performance 9476consistency for read and write operations. 9477 </p> 9478 <ul> 9479 <li> 9480 <strong> 9481 Sequential write 9482 </strong> 9483 . Device implementations MUST ensure a sequential write 9484performance of at least 5MB/s for a 256MB file using 10MB write buffer. 9485 </li> 9486 <li> 9487 <strong> 9488 Random write 9489 </strong> 9490 . Device implementations MUST ensure a random write 9491performance of at least 0.5MB/s for a 256MB file using 4KB write buffer. 9492 </li> 9493 <li> 9494 <strong> 9495 Sequential read 9496 </strong> 9497 . Device implementations MUST ensure a sequential read 9498performance of at least 15MB/s for a 256MB file using 10MB write buffer. 9499 </li> 9500 <li> 9501 <strong> 9502 Random read 9503 </strong> 9504 . Device implementations MUST ensure a random read 9505performance of at least 3.5MB/s for a 256MB file using 4KB write buffer. 9506 </li> 9507 </ul> 9508 <h2 id="8_3_power-saving_modes"> 9509 8.3. Power-Saving Modes 9510 </h2> 9511 <p> 9512 Android 6.0 introduced App Standby and Doze power-saving modes to optimize 9513battery usage. All Apps exempted from these modes MUST be made visible to the 9514end user. Further, the triggering, maintenance, wakeup algorithms and the use of 9515global system settings of these power-saving modes MUST not deviate from the 9516Android Open Source Project. 9517 </p> 9518 <p> 9519 In addition to the power-saving modes, Android device implementations MAY 9520implement any or all of the 4 sleeping power states as defined by the Advanced 9521Configuration and Power Interface (ACPI), but if it implements S3 and S4 9522power states, it can only enter these states when closing a lid that is 9523physically part of the device. 9524 </p> 9525 <h2 id="8_4_power_consumption_accounting"> 9526 8.4. Power Consumption Accounting 9527 </h2> 9528 <p> 9529 A more accurate accounting and reporting of the power consumption provides the 9530app developer both the incentives and the tools to optimize the power usage 9531pattern of the application. Therefore, device implementations: 9532 </p> 9533 <ul> 9534 <li> 9535 MUST be able to track hardware component power usage and attribute that 9536power usage to specific applications. Specifically, implementations: 9537 <ul> 9538 <li> 9539 MUST provide a per-component power profile that defines the 9540 <a href="http://source.android.com/devices/tech/power/values.html"> 9541 current consumption value</a> for each hardware component and the approximate battery drain caused by the 9542components over time as documented in the Android Open Source Project site. 9543 </li> 9544 <li> 9545 MUST report all power consumption values in milliampere hours (mAh). 9546 </li> 9547 <li> 9548 SHOULD be attributed to the hardware component itself if unable to 9549attribute hardware component power usage to an application. 9550 </li> 9551 <li> 9552 MUST report CPU power consumption per each process's UID. The Android 9553Open Source Project meets the requirement through the 9554 <code> 9555 uid_cputime 9556 </code> 9557 kernel 9558module implementation. 9559 </li> 9560 </ul> 9561 </li> 9562 <li> 9563 MUST make this power usage available via the 9564 <a href="http://source.android.com/devices/tech/power/batterystats.html"> 9565 <code> adb shell dumpsys batterystats </code></a> shell command to the app developer. 9566 </li> 9567 <li> 9568 MUST honor the 9569 <a href="http://developer.android.com/reference/android/content/Intent.html#ACTION_POWER_USAGE_SUMMARY">android.intent.action.POWER_USAGE_SUMMARY</a> intent and display a settings menu that shows this power usage. 9570 </li> 9571 </ul> 9572 <h2 id="8_5_consistent_performance"> 9573 8.5. Consistent Performance 9574 </h2> 9575 <p> 9576 Performance can fluctuate dramatically for high-performance long-running apps, 9577either because of the other apps running in the background or the CPU throttling 9578due to temperature limits. Android includes programmatic interfaces so that when 9579the device is capable, the top foreground application can request that the system 9580optimize the allocation of the resources to address such fluctuations. 9581 </p> 9582 <p> 9583 Device implementations SHOULD support Sustained Performance Mode which can 9584provide the top foreground application a consistent level of performance for a 9585prolonged amount of time when requested through the 9586 <a href="https://developer.android.com/reference/android/view/Window.html#setSustainedPerformanceMode%28boolean%29"> 9587 <code> Window.setSustainedPerformanceMode()</code></a> 9588 API method. A Device implementation MUST report the support of Sustained 9589Performance Mode accurately through the 9590 <a href="https://developer.android.com/reference/android/os/PowerManager.html#isSustainedPerformanceModeSupported%28%29"> 9591 <code> PowerManager.isSustainedPerformanceModeSupported()</code></a> API method. 9592 </p> 9593 <p> 9594 Device implementations with two or more CPU cores SHOULD provide at least one exclusive core that 9595can be reserved by the top foreground application. If provided, implementations MUST meet the 9596following requirements: 9597 </p> 9598 <ul> 9599 <li> 9600 Implementations MUST report through the 9601 <a href="https://developer.android.com/reference/android/os/Process.html#getExclusiveCores()"> 9602 <code> Process.getExclusiveCores()</code></a> 9603 API method the id numbers of the exclusive cores that can be reserved by the top foreground 9604 application. 9605 </li> 9606 <li> 9607 Device implementations MUST not allow any user space processes except the device drivers used 9608 by the application to run on the exclusive cores, but MAY allow some kernel processes to run 9609 as necessary. 9610 </li> 9611 </ul> 9612 <p> 9613 If a device implementation does not support an exclusive core, it MUST return an 9614empty list through the 9615 <a href="https://developer.android.com/reference/android/os/Process.html#getExclusiveCores()"> 9616 <code> Process.getExclusiveCores()</code></a> API method. 9617 </p> 9618 <h1 id="9_security_model_compatibility"> 9619 9. Security Model Compatibility 9620 </h1> 9621 <p> 9622 Device implementations MUST implement a security model consistent with the 9623Android platform security model as defined in 9624 <a href="http://developer.android.com/guide/topics/security/permissions.html"> 9625 Security and Permissions 9626reference document 9627 </a> 9628 in the APIs in the Android developer documentation. Device implementations MUST 9629support installation of self-signed applications without requiring any 9630additional permissions/certificates from any third parties/authorities. 9631Specifically, compatible devices MUST support the security mechanisms described 9632in the follow subsections. 9633 </p> 9634 <h2 id="9_1_permissions"> 9635 9.1. Permissions 9636 </h2> 9637 <p> 9638 Device implementations MUST support the 9639 <a href="http://developer.android.com/guide/topics/security/permissions.html"> 9640 Android permissions model</a> as 9641defined in the Android developer documentation. Specifically, implementations 9642MUST enforce each permission defined as described in the SDK documentation; no 9643permissions may be omitted, altered, or ignored. Implementations MAY add 9644additional permissions, provided the new permission ID strings are not in the 9645android.* namespace. 9646 </p> 9647 <p> 9648 Permissions with a protection level of dangerous are runtime permissions. 9649Applications with targetSdkVersion > 22 request them at runtime. Device 9650implementations: 9651 </p> 9652 <ul> 9653 <li> 9654 MUST show a dedicated interface for the user to decide whether to grant the 9655requested runtime permissions and also provide an interface for the user to 9656manage runtime permissions. 9657 </li> 9658 <li> 9659 MUST have one and only one implementation of both user interfaces. 9660 </li> 9661 <li> 9662 MUST NOT grant any runtime permissions to preinstalled apps unless: 9663 <ul> 9664 <li> 9665 the user's consent can be obtained before the application uses it 9666 </li> 9667 <li> 9668 the runtime permissions are associated with an intent pattern for which 9669the preinstalled application is set as the default handler 9670 </li> 9671 </ul> 9672 </li> 9673 </ul> 9674 <h2 id="9_2_uid_and_process_isolation"> 9675 9.2. UID and Process Isolation 9676 </h2> 9677 <p> 9678 Device implementations MUST support the Android application sandbox model, in 9679which each application runs as a unique Unixstyle UID and in a separate 9680process. Device implementations MUST support running multiple applications as 9681the same Linux user ID, provided that the applications are properly signed and 9682constructed, as defined in the 9683 <a href="http://developer.android.com/guide/topics/security/permissions.html"> 9684 Security and Permissions reference</a>. 9685 </p> 9686 <h2 id="9_3_filesystem_permissions"> 9687 9.3. Filesystem Permissions 9688 </h2> 9689 <p> 9690 Device implementations MUST support the Android file access permissions model 9691as defined in the 9692 <a href="http://developer.android.com/guide/topics/security/permissions.html"> 9693 Security and Permissions reference</a>. 9694 </p> 9695 <h2 id="9_4_alternate_execution_environments"> 9696 9.4. Alternate Execution Environments 9697 </h2> 9698 <p> 9699 Device implementations MAY include runtime environments that execute 9700applications using some other software or technology than the Dalvik Executable 9701Format or native code. However, such alternate execution environments MUST NOT 9702compromise the Android security model or the security of installed Android 9703applications, as described in this section. 9704 </p> 9705 <p> 9706 Alternate runtimes MUST themselves be Android applications, and abide by the 9707standard Android security model, as described elsewhere in 9708 <a href="#9_security_model_compatibility"> 9709 section 9</a>. 9710 </p> 9711 <p> 9712 Alternate runtimes MUST NOT be granted access to resources protected by 9713permissions not requested in the runtime’s AndroidManifest.xml file via the 9714<uses-permission> mechanism. 9715 </p> 9716 <p> 9717 Alternate runtimes MUST NOT permit applications to make use of features 9718protected by Android permissions restricted to system applications. 9719 </p> 9720 <p> 9721 Alternate runtimes MUST abide by the Android sandbox model. Specifically, 9722alternate runtimes: 9723 </p> 9724 <ul> 9725 <li> 9726 SHOULD install apps via the PackageManager into separate Android sandboxes 9727(Linux user IDs, etc.). 9728 </li> 9729 <li> 9730 MAY provide a single Android sandbox shared by all applications using the 9731alternate runtime. 9732 </li> 9733 <li> 9734 Installed applications using an alternate runtime MUST NOT reuse the 9735sandbox of any other app installed on the device, except through the standard 9736Android mechanisms of shared user ID and signing certificate. 9737 </li> 9738 <li> 9739 MUST NOT launch with, grant, or be granted access to the sandboxes 9740corresponding to other Android applications. 9741 </li> 9742 <li> 9743 MUST NOT be launched with, be granted, or grant to other applications any 9744privileges of the superuser (root), or of any other user ID. 9745 </li> 9746 </ul> 9747 <p> 9748 The .apk files of alternate runtimes MAY be included in the system image of a 9749device implementation, but MUST be signed with a key distinct from the key used 9750to sign other applications included with the device implementation. 9751 </p> 9752 <p> 9753 When installing applications, alternate runtimes MUST obtain user consent for 9754the Android permissions used by the application. If an application needs to 9755make use of a device resource for which there is a corresponding Android 9756permission (such as Camera, GPS, etc.), the alternate runtime MUST inform the 9757user that the application will be able to access that resource. If the runtime 9758environment does not record application capabilities in this manner, the 9759runtime environment MUST list all permissions held by the runtime itself when 9760installing any application using that runtime. 9761 </p> 9762 <h2 id="9_5_multi-user_support"> 9763 9.5. Multi-User Support 9764 </h2> 9765 <div class="note"> 9766 This feature is optional for all device types. 9767 </div> 9768 <p> 9769 Android includes 9770 <a href="http://developer.android.com/reference/android/os/UserManager.html"> 9771 support for multiple users</a> and 9772provides support for full user isolation. Device implementations MAY enable 9773multiple users, but when enabled MUST meet the following requirements related 9774to 9775 <a href="http://source.android.com/devices/storage/traditional.html">multi-user support</a>: 9776 </p> 9777 <ul> 9778 <li> 9779 Android Automotive device implementations with multi-user support enabled 9780MUST include a guest account that allows all functions provided by the vehicle 9781system without requiring a user to log in. 9782 </li> 9783 <li> 9784 Device implementations that do not declare the android.hardware.telephony 9785feature flag MUST support restricted profiles, a feature that allows device 9786owners to manage additional users and their capabilities on the device. With 9787restricted profiles, device owners can quickly set up separate environments for 9788additional users to work in, with the ability to manage finer-grained 9789restrictions in the apps that are available in those environments. 9790 </li> 9791 <li> 9792 Conversely device implementations that declare the 9793android.hardware.telephony feature flag MUST NOT support restricted profiles 9794but MUST align with the AOSP implementation of controls to enable /disable 9795other users from accessing the voice calls and SMS. 9796 </li> 9797 <li> 9798 Device implementations MUST, for each user, implement a security model 9799consistent with the Android platform security model as defined in 9800 <a href="http://developer.android.com/guide/topics/security/permissions.html"> 9801 Security and Permissions reference document</a> in the APIs. 9802 </li> 9803 <li> 9804 Each user instance on an Android device MUST have separate and isolated 9805external storage directories. Device implementations MAY store multiple users' 9806data on the same volume or filesystem. However, the device implementation MUST 9807ensure that applications owned by and running on behalf a given user cannot 9808list, read, or write to data owned by any other user. Note that removable 9809media, such as SD card slots, can allow one user to access another’s data by 9810means of a host PC. For this reason, device implementations that use removable 9811media for the external storage APIs MUST encrypt the contents of the SD card if 9812multiuser is enabled using a key stored only on non-removable media accessible 9813only to the system. As this will make the media unreadable by a host PC, device 9814implementations will be required to switch to MTP or a similar system to 9815provide host PCs with access to the current user’s data. Accordingly, device 9816implementations MAY but SHOULD NOT enable multi-user if they use 9817 <a href="http://developer.android.com/reference/android/os/Environment.html"> 9818 removable media</a> for primary external storage. 9819 </li> 9820 </ul> 9821 <h2 id="9_6_premium_sms_warning"> 9822 9.6. Premium SMS Warning 9823 </h2> 9824 <p> 9825 Android includes support for warning users of any outgoing 9826 <a href="http://en.wikipedia.org/wiki/Short_code"> 9827 premium SMS message</a>. Premium SMS messages are 9828text messages sent to a service registered with a carrier that may incur a 9829charge to the user. Device implementations that declare support for 9830android.hardware.telephony MUST warn users before sending a SMS message to 9831numbers identified by regular expressions defined in /data/misc/sms/codes.xml 9832file in the device. The upstream Android Open Source Project provides an 9833implementation that satisfies this requirement. 9834 </p> 9835 <h2 id="9_7_kernel_security_features"> 9836 9.7. Kernel Security Features 9837 </h2> 9838 <p> 9839 The Android Sandbox includes features that use the Security-Enhanced Linux 9840(SELinux) mandatory access control (MAC) system, seccomp sandboxing, and other 9841security features in the Linux kernel. SELinux or any other security features 9842implemented below the Android framework: 9843 </p> 9844 <ul> 9845 <li> 9846 MUST maintain compatibility with existing applications. 9847 </li> 9848 <li> 9849 MUST NOT have a visible user interface when a security violation is 9850detected and successfully blocked, but MAY have a visible user interface when 9851an unblocked security violation occurs resulting in a successful exploit. 9852 </li> 9853 <li> 9854 SHOULD NOT be user or developer configurable. 9855 </li> 9856 </ul> 9857 <p> 9858 If any API for configuration of policy is exposed to an application that can 9859affect another application (such as a Device Administration API), the API MUST 9860NOT allow configurations that break compatibility. 9861 </p> 9862 <p> 9863 Devices MUST implement SELinux or, if using a kernel other than Linux, an 9864equivalent mandatory access control system. Devices MUST also meet the 9865following requirements, which are satisfied by the reference implementation in 9866the upstream Android Open Source Project. 9867 </p> 9868 <p> 9869 Device implementations: 9870 </p> 9871 <ul> 9872 <li> 9873 MUST set SELinux to global enforcing mode. 9874 </li> 9875 <li> 9876 MUST configure all domains in enforcing mode. No permissive mode domains 9877are allowed, including domains specific to a device/vendor. 9878 </li> 9879 <li> 9880 MUST NOT modify, omit, or replace the neverallow rules present within the 9881system/sepolicy folder provided in the upstream Android Open Source Project 9882(AOSP) and the policy MUST compile with all neverallow rules present, for both 9883AOSP SELinux domains as well as device/vendor specific domains. 9884 </li> 9885 <li> 9886 MUST split the media framework into multiple processes so that it 9887is possible to more narrowly grant access for each process as 9888 <a href="https://source.android.com/devices/media/framework-hardening.html#arch_changes">described</a> in the Android Open Source Project site. 9889 </li> 9890 </ul> 9891 <p> 9892 Device implementations SHOULD retain the default SELinux policy provided in the 9893system/sepolicy folder of the upstream Android Open Source Project and only 9894further add to this policy for their own device-specific configuration. Device 9895implementations MUST be compatible with the upstream Android Open Source 9896Project. 9897 </p> 9898 <p> 9899 Devices MUST implement a kernel application sandboxing mechanism which allows 9900filtering of system calls using a configurable policy from multithreaded 9901programs. The upstream Android Open Source Project meets this requirement 9902through enabling the seccomp-BPF with threadgroup synchronization (TSYNC) as 9903described 9904 <a href="http://source.android.com/devices/tech/config/kernel.html#Seccomp-BPF-TSYNC">in the Kernel Configuration section of source.android.com</a>. 9905 </p> 9906 <h2 id="9_8_privacy"> 9907 9.8. Privacy 9908 </h2> 9909 <p> 9910 If the device implements functionality in the system that captures the contents 9911displayed on the screen and/or records the audio stream played on the device, 9912it MUST continuously notify the user whenever this functionality is enabled and 9913actively capturing/recording. 9914 </p> 9915 <p> 9916 If a device implementation has a mechanism that routes network data traffic 9917through a proxy server or VPN gateway by default (for example, preloading a VPN 9918service with android.permission.CONTROL_VPN granted), the device implementation 9919MUST ask for the user's consent before enabling that mechanism, unless that 9920VPN is enabled by the Device Policy Controller via the 9921 <a href="https://developer.android.com/reference/android/app/admin/DevicePolicyManager.html#setAlwaysOnVpnPackage(android.content.ComponentName, java.lang.String, boolean)"> 9922 <code> DevicePolicyManager.setAlwaysOnVpnPackage()</code></a>, in which case 9923 the user does not need to provide a separate consent, but MUST 9924only be notified. 9925 </p> 9926 <p> 9927 Device implementations MUST ship with an empty user-added Certificate Authority 9928(CA) store, and MUST preinstall the same root certificates for the system-trusted 9929CA store as 9930 <a href="https://source.android.com/security/overview/app-security.html#certificate-authorities">provided</a> in the upstream Android Open Source Project. 9931 </p> 9932 <p> 9933 When devices are routed through a VPN, or a user root CA is installed, the 9934implementation MUST display a warning indicating the network traffic may be 9935monitored to the user. 9936 </p> 9937 <p> 9938 If a device implementation has a USB port with USB peripheral mode support, it 9939MUST present a user interface asking for the user's consent before allowing 9940access to the contents of the shared storage over the USB port. 9941 </p> 9942 <h2 id="9_9_data_storage_encryption"> 9943 9.9. Data Storage Encryption 9944 </h2> 9945 <div class="note"> 9946 Optional for Android device implementations without a secure lock screen. 9947 </div> 9948 <p> 9949 If the device implementation supports a secure lock screen as described in section 9.11.1, 9950then the device MUST support data storage encryption of the application private data (/data partition), as well as the 9951application shared storage partition (/sdcard partition) if it is a permanent, 9952non-removable part of the device. 9953 </p> 9954 <p> 9955 For device implementations supporting data storage encryption and with Advanced 9956Encryption Standard (AES) crypto performance above 50MiB/sec, the data storage 9957encryption MUST be enabled by default at the time the user has completed the 9958out-of-box setup experience. If a device implementation is already launched on 9959an earlier Android version with encryption disabled by default, such 9960a device cannot meet the requirement through a system software update and thus 9961MAY be exempted. 9962 </p> 9963 <p> 9964 Device implementations SHOULD meet the above data storage encryption requirement 9965via implementing 9966 <a href="https://source.android.com/security/encryption/file-based.html">File Based Encryption</a>( FBE). 9967 </p> 9968 <h3 id="9_9_1_direct_boot"> 9969 9.9.1. Direct Boot 9970 </h3> 9971 <p> 9972 All devices MUST implement the 9973 <a href="http://developer.android.com/preview/features/direct-boot.html"> 9974 Direct Boot 9975mode 9976 </a> 9977 APIs even 9978if they do not support Storage Encryption. In particular, the 9979LOCKED_BOOT_COMPLETED(https://developer.android.com/reference/android/content/Intent.html#LOCKED_BOOT_COMPLETED) 9980and 9981 <a href="https://developer.android.com/reference/android/content/Intent.html#ACTION_USER_UNLOCKED">ACTION_USER_UNLOCKED</a> Intents must still be broadcast to signal Direct Boot aware applications that 9982Device Encrypted (DE) and Credential Encrypted (CE) storage locations are 9983available for user. 9984 </p> 9985 <h3 id="9_9_2_file_based_encryption"> 9986 9.9.2. File Based Encryption 9987 </h3> 9988 <p> 9989 Device implementations supporting FBE: 9990 </p> 9991 <ul> 9992 <li> 9993 MUST boot up without challenging the user for credentials and allow Direct 9994 Boot aware apps to access to the Device Encrypted (DE) storage after the 9995 LOCKED_BOOT_COMPLETED message is broadcasted. 9996 </li> 9997 <li> 9998 MUST only allow access to Credential Encrypted (CE) storage after the user 9999 has unlocked the device by supplying their credentials (eg. passcode, pin, 10000 pattern or fingerprint) and the ACTION_USER_UNLOCKED message is broadcasted. 10001 Device implementations MUST NOT offer any 10002 method to unlock the CE protected storage without the user supplied 10003 credentials. 10004 </li> 10005 <li> 10006 MUST support Verified Boot and ensure that DE keys are cryptographically 10007 bound to the device's hardware root of trust. 10008 </li> 10009 <li> 10010 MUST support encrypting file contents using AES with a key length of 256-bits 10011 in XTS mode. 10012 </li> 10013 <li> 10014 MUST support encrypting file name using AES with a key length of 256-bits in 10015 CBC-CTS mode. 10016 </li> 10017 <li> 10018 MAY support alternative ciphers, key lengths and modes for file content and 10019 file name encryption, but MUST use the mandatorily supported ciphers, 10020 key lengths and modes by default. 10021 </li> 10022 <li> 10023 SHOULD make preloaded essential apps (e.g. Alarm, Phone, Messenger) 10024 Direct Boot aware. 10025 </li> 10026 </ul> 10027 <p> 10028 The keys protecting CE and DE storage areas: 10029 </p> 10030 <ul> 10031 <li> 10032 MUST be cryptographically bound to a hardware-backed Keystore. CE keys 10033 must be bound to a user's lock screen credentials. If the user has 10034 specified no lock screen credentials then the CE keys MUST be bound to 10035 a default passcode. 10036 </li> 10037 <li> 10038 MUST be unique and distinct, in other words no user's CE or DE key 10039 may match any other user's CE or DE keys. 10040 </li> 10041 </ul> 10042 <p> 10043 The upstream Android Open Source project provides a preferred implementation of 10044this feature based on the Linux kernel ext4 encryption feature. 10045 </p> 10046 <h3 id="9_9_3_full_disk_encryption"> 10047 9.9.3. Full Disk Encryption 10048 </h3> 10049 <p> 10050 Device implementations supporting 10051 <a href="http://source.android.com/devices/tech/security/encryption/index.html">full disk encryption</a> (FDE). MUST use AES with a key of 128-bits 10052 (or greater) and a mode designed for storage (for example, AES-XTS, 10053 AES-CBC-ESSIV). The encryption key MUST NOT be written to storage at any time 10054 without being encrypted. Other than when in active use, the encryption key 10055 SHOULD be AES encrypted with the lock screen credentials stretched using a slow 10056 stretching algorithm (e.g. PBKDF2 or scrypt). If the user has not specified 10057 a lock screen credentials or has disabled use of the passcode for encryption, the 10058 system SHOULD use a default passcode to wrap the encryption key. If the 10059 device provides a hardware-backed keystore, the password stretching algorithm 10060 MUST be cryptographically bound to that keystore. The encryption key MUST NOT 10061 be sent off the device (even when wrapped with the user passcode and/or 10062 hardware bound key). The upstream Android Open Source project provides a 10063 preferred implementation of this feature based on the Linux kernel feature 10064 dm-crypt. 10065 </p> 10066 <h2 id="9_10_device_integrity"> 10067 9.10. Device Integrity 10068 </h2> 10069 <p> 10070 The following requirements ensures there is transparancy to the status of the 10071device integrity. 10072 </p> 10073 <p> 10074 Device implementations MUST correctly report through the System API method 10075PersistentDataBlockManager.getFlashLockState() whether their bootloader state 10076permits flashing of the system image. The 10077 <code> 10078 FLASH_LOCK_UNKNOWN 10079 </code> 10080 state is reserved 10081for device implementations upgrading from an earlier version of Android where this 10082new system API method did not exist. 10083 </p> 10084 <p> 10085 Verified boot is a feature that guarantees the integrity of the device 10086software. If a device implementation supports the feature, it MUST: 10087 </p> 10088 <ul> 10089 <li> 10090 Declare the platform feature flag android.software.verified_boot. 10091 </li> 10092 <li> 10093 Perform verification on every boot sequence. 10094 </li> 10095 <li> 10096 Start verification from an immutable hardware key that is the root of trust 10097and go all the way up to the system partition. 10098 </li> 10099 <li> 10100 Implement each stage of verification to check the integrity and 10101authenticity of all the bytes in the next stage before executing the code in 10102the next stage. 10103 </li> 10104 <li> 10105 Use verification algorithms as strong as current recommendations from NIST 10106for hashing algorithms (SHA-256) and public key sizes (RSA-2048). 10107 </li> 10108 <li> 10109 MUST NOT allow boot to complete when system verification fails, unless the 10110user consents to attempt booting anyway, in which case the data from any 10111non-verified storage blocks MUST not be used. 10112 </li> 10113 <li> 10114 MUST NOT allow verified partitions on the device to be modified unless the 10115user has explicitly unlocked the boot loader. 10116 </li> 10117 </ul> 10118 <p> 10119 The upstream Android Open Source Project provides a preferred implementation of 10120this feature based on the Linux kernel feature dm-verity. 10121 </p> 10122 <p> 10123 Starting from Android 6.0, device implementations with Advanced Encryption 10124Standard (AES) crypto performance above 50 MiB/seconds MUST support verified boot 10125for device integrity. 10126 </p> 10127 <p> 10128 If a device implementation is already launched without supporting verified boot 10129on an earlier version of Android, such a device can not add support for this feature 10130with a system software update and thus are exempted from the requirement. 10131 </p> 10132 <h2 id="9_11_keys_and_credentials"> 10133 9.11. Keys and Credentials 10134 </h2> 10135 <p> 10136 The 10137 <a href="https://developer.android.com/training/articles/keystore.html"> 10138 Android Keystore System</a> allows 10139app developers to store cryptographic keys in a container and use them in 10140cryptographic operations through the 10141 <a href="https://developer.android.com/reference/android/security/KeyChain.html"> 10142 KeyChain API</a> or the 10143 <a href="https://developer.android.com/reference/java/security/KeyStore.html">Keystore API</a>. 10144 </p> 10145 <p> 10146 All Android device implementations MUST meet the following requirements: 10147 </p> 10148 <ul> 10149 <li> 10150 SHOULD not limit the number of keys that can be generated, and MUST at 10151 least allow more than 8,192 keys to be imported. 10152 </li> 10153 <li> 10154 The lock screen authentication MUST rate limit attempts and MUST have an 10155 exponential backoff algorithm. Beyond 150 failed attempts, the delay MUST be 10156 at least 24 hours per attempt. 10157 </li> 10158 <li> 10159 When the device implementation supports a secure lock screen it MUST back up the 10160 keystore implementation with secure hardware and meet following requirements: 10161 <ul> 10162 <li> 10163 MUST have hardware backed implementations of RSA, AES, ECDSA and HMAC cryptographic 10164algorithms and MD5, SHA1, SHA-2 Family hash functions to properly support the 10165 <a href="https://developer.android.com/training/articles/keystore.html#SupportedAlgorithms">Android Keystore system's supported algorithms</a>. 10166 </li> 10167 <li> 10168 MUST perform the lock screen authentication in the secure hardware and only when 10169successful allow the authentication-bound keys to be used. The upstream Android 10170Open Source Project provides the 10171 <a href="http://source.android.com/devices/tech/security/authentication/gatekeeper.html"> 10172 Gatekeeper Hardware Abstraction Layer (HAL)</a> that can be used to satisfy this requirement. 10173 </li> 10174 </ul> 10175 </li> 10176 </ul> 10177 <p> 10178 Note that if a device implementation is already launched on an earlier Android version, and does 10179not have a fingerprint scanner, such a device is exempted from the requirement to have a 10180hardware-backed keystore. 10181 </p> 10182 <h3 id="9_11_1_secure_lock_screen"> 10183 9.11.1. Secure Lock Screen 10184 </h3> 10185 <p> 10186 Device implementations MAY add or modify the authentication methods to unlock 10187the lock screen, but MUST still meet the following requirements: 10188 </p> 10189 <ul> 10190 <li> 10191 The authentication method, if based on a known secret, MUST NOT be treated 10192 as a secure lock screen unless it meets all following requirements: 10193 <ul> 10194 <li> 10195 The entropy of the shortest allowed length of inputs MUST be greater 10196 than 10 bits. 10197 </li> 10198 <li> 10199 The maximum entropy of all possible inputs MUST be greater than 18 bits. 10200 </li> 10201 <li> 10202 MUST not replace any of the existing authentication methods (PIN, 10203 pattern, password) implemented and provided in AOSP. 10204 </li> 10205 <li> 10206 MUST be disabled when the Device Policy Controller (DPC) application 10207 has set the password quality policy via the 10208 <a href="https://developer.android.com/reference/android/app/admin/DevicePolicyManager.html#setPasswordQuality(android.content.ComponentName,%20int)"> 10209 <code> DevicePolicyManager.setPasswordQuality()</code></a> method with a more restrictive quality constant than 10210 <code> PASSWORD_QUALITY_SOMETHING</code>. 10211 </li> 10212 </ul> 10213 </li> 10214 <li> 10215 The authenticaion method, if based on a physical token or the location, 10216 MUST NOT be treated as a secure lock screen unless it meets all following 10217 requirements: 10218 <ul> 10219 <li> 10220 It MUST have a fall-back mechanism to use one of the primary 10221 authentication methods which is based on a known secret and meets 10222 the requirements to be treated as a secure lock screen. 10223 </li> 10224 <li> 10225 It MUST be disabled and only allow the primary authentication to 10226 unlock the screen when the Device Policy Controller (DPC) application 10227 has set the policy with either the 10228 <a href="http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html#setKeyguardDisabledFeatures(android.content.ComponentName,%20int)"> 10229 <code> DevicePolicyManager.setKeyguardDisabledFeatures(KEYGUARD_DISABLE_TRUST_AGENTS)</code></a> method or the 10230 <a href="https://developer.android.com/reference/android/app/admin/DevicePolicyManager.html#setPasswordQuality(android.content.ComponentName,%20int)"> 10231 <code> DevicePolicyManager.setPasswordQuality()</code></a> method with a more restrictive quality constant than 10232 <code> PASSWORD_QUALITY_UNSPECIFIED</code>. 10233 </li> 10234 </ul> 10235 </li> 10236 <li> 10237 The authentication method, if based on biometrics, MUST NOT be treated as a 10238 secure lock screen unless it meets all following requirements: 10239 <ul> 10240 <li> 10241 It MUST have a fall-back mechanism to use one of the primary 10242 authentication methods which is based on a known secret and meets 10243 the requirements to be treated as a secure lock screen. 10244 </li> 10245 <li> 10246 It MUST be disabled and only allow the primary authentication to 10247 unlock the screen when the Device Policy Controller (DPC) application 10248 has set the keguard feature policy by calling the method 10249 <a href="http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html#setKeyguardDisabledFeatures(android.content.ComponentName,%20int)"> 10250 <code> DevicePolicyManager.setKeyguardDisabledFeatures(KEYGUARD_DISABLE_FINGERPRINT)</code></a>. 10251 </li> 10252 <li> 10253 It MUST have a false acceptance rate that is equal or stronger than 10254 what is required for a fingerprint sensor as described in 10255 section 7.3.10, or otherwise MUST be disabled and only allow the 10256 primary authentication to unlock the screen when the Device Policy 10257 Controller (DPC) application has set the password quality policy 10258 via the 10259 <a href="https://developer.android.com/reference/android/app/admin/DevicePolicyManager.html#setPasswordQuality(android.content.ComponentName,%20int)"> 10260 <code> DevicePolicyManager.setPasswordQuality()</code></a> method with a more restrictive quality constant than 10261 <code> PASSWORD_QUALITY_BIOMETRIC_WEAK</code>. 10262 </li> 10263 </ul> 10264 </li> 10265 <li> 10266 If the authentication method can not be treated as a secure lock screen, 10267 it: 10268 <ul> 10269 <li> 10270 MUST return 10271 <code> 10272 false 10273 </code> 10274 for both the 10275 <a href="http://developer.android.com/reference/android/app/KeyguardManager.html#isKeyguardSecure()"> 10276 <code> KeyguardManager.isKeyguardSecure()</code></a> and the 10277 <a href="https://developer.android.com/reference/android/app/KeyguardManager.html#isDeviceSecure()"> 10278 <code> KeyguardManager.isDeviceSecure()</code></a> methods. 10279 </li> 10280 <li> 10281 MUST be disabled when the Device Policy Controller (DPC) application 10282 has set the password quality policy via the 10283 <a href="https://developer.android.com/reference/android/app/admin/DevicePolicyManager.html#setPasswordQuality(android.content.ComponentName,%20int)"> 10284 <code> DevicePolicyManager.setPasswordQuality()</code></a> method with a more restrictive quality constant than 10285 <code> PASSWORD_QUALITY_UNSPECIFIED</code>. 10286 </li> 10287 <li> 10288 MUST NOT reset the password expiration timers set by 10289 <a href="http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html#setPasswordExpirationTimeout(android.content.ComponentName,%20long)"> 10290 <code> DevicePolicyManager.setPasswordExpirationTimeout()</code></a>. 10291 </li> 10292 <li> 10293 MUST NOT authenticate access to keystores if the application has called 10294 <a href="https://developer.android.com/reference/android/security/keystore/KeyGenParameterSpec.Builder.html#setUserAuthenticationRequired(boolean)"> 10295 <code> KeyGenParameterSpec.Builder.setUserAuthenticationRequired(true)</code></a>. 10296 </li> 10297 </ul> 10298 </li> 10299 <li> 10300 If the authentication method is based on a physical token, the location, 10301 or biometrics that has higher false acceptance rate than what is required 10302 for fingerprint sensors as described in section 7.3.10, then it: 10303 <ul> 10304 <li> 10305 MUST NOT reset the password expiration timers set by 10306 <a href="http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html#setPasswordExpirationTimeout(android.content.ComponentName,%20long)"> 10307 <code> DevicePolicyManager.setPasswordExpirationTimeout()</code></a>. 10308 </li> 10309 <li> 10310 MUST NOT authenticate access to keystores if the application has called 10311 <a href="https://developer.android.com/reference/android/security/keystore/KeyGenParameterSpec.Builder.html#setUserAuthenticationRequired(boolean)"> 10312 <code> KeyGenParameterSpec.Builder.setUserAuthenticationRequired(true)</code></a>. 10313 </li> 10314 </ul> 10315 </li> 10316 </ul> 10317 <h2 id="9_12_data_deletion"> 10318 9.12. Data Deletion 10319 </h2> 10320 <p> 10321 Devices MUST provide users with a mechanism to perform a "Factory Data Reset" 10322that allows logical and physical deletion of all data except for the following: 10323 </p> 10324 <ul> 10325 <li> 10326 The system image 10327 </li> 10328 <li> 10329 Any operating system files required by the system image 10330 </li> 10331 </ul> 10332 <p> 10333 All user-generated data MUST be deleted. This MUST satisfy relevant industry 10334standards for data deletion such as NIST SP800-88. This MUST be used for the 10335implementation of the wipeData() API (part of the Android Device Administration 10336API) described in 10337 <a href="#3_9_device_administration"> 10338 section 3.9 Device Administration</a>. 10339 </p> 10340 <p> 10341 Devices MAY provide a fast data wipe that conducts a logical data erase. 10342 </p> 10343 <h2 id="9_13_safe_boot_mode"> 10344 9.13. Safe Boot Mode 10345 </h2> 10346 <p> 10347 Android provides a mode enabling users to boot up into a mode where only 10348preinstalled system apps are allowed to run and all third-party apps are 10349disabled. This mode, known as "Safe Boot Mode", provides the user the 10350capability to uninstall potentially harmful third-party apps. 10351 </p> 10352 <p> 10353 Android device implementations are STRONGLY RECOMENDED to implement Safe Boot 10354Mode and meet following requirements: 10355 </p> 10356 <ul> 10357 <li> 10358 <p> 10359 Device implementations SHOULD provide the user an option to enter Safe Boot 10360 Mode from the boot menu which is reachable through a workflow that is different 10361 from that of normal boot. 10362 </p> 10363 </li> 10364 <li> 10365 <p> 10366 Device implementations MUST provide the user an option to enter Safe Boot Mode 10367 in such a way that is uninterruptible from third-party apps installed on 10368 the device, except for when the third party app is a Device Policy Controller 10369 and has set the 10370 <a href="https://developer.android.com/reference/android/os/UserManager.html#DISALLOW_SAFE_BOOT"> 10371 <code> UserManager.DISALLOW_SAFE_BOOT</code></a> flag as true. 10372 </p> 10373 </li> 10374 <li> 10375 <p> 10376 Device implementations MUST provide the user the capability to uninstall 10377 any third-party apps within Safe Mode. 10378 </p> 10379 </li> 10380 </ul> 10381 <h2 id="9_14_automotive_vehicle_system_isolation"> 10382 9.14. Automotive Vehicle System Isolation 10383 </h2> 10384 <p> 10385 Android Automotive devices are expected to exchange data with critical vehicle 10386subsystems, e.g., by using the 10387 <a href="http://source.android.com/devices/automotive.html">vehicle HAL</a> to send and receive 10388messages over vehicle networks such as CAN bus. Android Automotive device 10389implementations MUST implement security features below the Android framework 10390layers to prevent malicious or unintentional interaction between the Android 10391framework or third-party apps and vehicle subsystems. These security features 10392are as follows: 10393 </p> 10394 <ul> 10395 <li> 10396 Gatekeeping messages from Android framework vehicle subsystems, e.g., 10397 whitelisting permitted message types and message sources. 10398 </li> 10399 <li> 10400 Watchdog against denial of service attacks from the Android framework or 10401 third-party apps. This guards against malicious software flooding the vehicle 10402 network with traffic, which may lead to malfunctioning vehicle subsystems. 10403 </li> 10404 </ul> 10405 <h1 id="10_software_compatibility_testing"> 10406 10. Software Compatibility Testing 10407 </h1> 10408 <p> 10409 Device implementations MUST pass all tests described in this section. 10410 </p> 10411 <p> 10412 However, note that no software test package is fully comprehensive. For this 10413reason, device implementers are 10414 <strong> 10415 STRONGLY RECOMMENDED 10416 </strong> 10417 to make the minimum 10418number of changes as possible to the reference and preferred implementation of 10419Android available from the Android Open Source Project. This will minimize the 10420risk of introducing bugs that create incompatibilities requiring rework and 10421potential device updates. 10422 </p> 10423 <h2 id="10_1_compatibility_test_suite"> 10424 10.1. Compatibility Test Suite 10425 </h2> 10426 <p> 10427 Device implementations MUST pass the 10428 <a href="http://source.android.com/compatibility/index.html"> 10429 Android Compatibility Test Suite (CTS)</a> available from the 10430Android Open Source Project, using the final shipping software on the device. 10431Additionally, device implementers SHOULD use the reference implementation in 10432the Android Open Source tree as much as possible, and MUST ensure compatibility 10433in cases of ambiguity in CTS and for any reimplementations of parts of the 10434reference source code. 10435 </p> 10436 <p> 10437 The CTS is designed to be run on an actual device. Like any software, the CTS 10438may itself contain bugs. The CTS will be versioned independently of this 10439Compatibility Definition, and multiple revisions of the CTS may be released for 10440Android 7.0. Device implementations MUST pass the latest CTS 10441version available at the time the device software is completed. 10442 </p> 10443 <h2 id="10_2_cts_verifier"> 10444 10.2. CTS Verifier 10445 </h2> 10446 <p> 10447 Device implementations MUST correctly execute all applicable cases in the CTS 10448Verifier. The CTS Verifier is included with the Compatibility Test Suite, and 10449is intended to be run by a human operator to test functionality that cannot be 10450tested by an automated system, such as correct functioning of a camera and 10451sensors. 10452 </p> 10453 <p> 10454 The CTS Verifier has tests for many kinds of hardware, including some hardware 10455that is optional. Device implementations MUST pass all tests for hardware that 10456they possess; for instance, if a device possesses an accelerometer, it MUST 10457correctly execute the Accelerometer test case in the CTS Verifier. Test cases 10458for features noted as optional by this Compatibility Definition Document MAY be 10459skipped or omitted. 10460 </p> 10461 <p> 10462 Every device and every build MUST correctly run the CTS Verifier, as noted 10463above. However, since many builds are very similar, device implementers are not 10464expected to explicitly run the CTS Verifier on builds that differ only in 10465trivial ways. Specifically, device implementations that differ from an 10466implementation that has passed the CTS Verifier only by the set of included 10467locales, branding, etc. MAY omit the CTS Verifier test. 10468 </p> 10469 <h1 id="11_updatable_software"> 10470 11. Updatable Software 10471 </h1> 10472 <p> 10473 Device implementations MUST include a mechanism to replace the entirety of the 10474system software. The mechanism need not perform “live” upgrades—that is, a 10475device restart MAY be required. 10476 </p> 10477 <p> 10478 Any method can be used, provided that it can replace the entirety of the 10479software preinstalled on the device. For instance, any of the following 10480approaches will satisfy this requirement: 10481 </p> 10482 <ul> 10483 <li> 10484 “Over-the-air (OTA)” downloads with offline update via reboot. 10485 </li> 10486 <li> 10487 “Tethered” updates over USB from a host PC. 10488 </li> 10489 <li> 10490 “Offline” updates via a reboot and update from a file on removable storage. 10491 </li> 10492 </ul> 10493 <p> 10494 However, if the device implementation includes support for an unmetered data 10495connection such as 802.11 or Bluetooth PAN (Personal Area Network) profile, it 10496MUST support OTA downloads with offline update via reboot. 10497 </p> 10498 <p> 10499 The update mechanism used MUST support updates without wiping user data. That 10500is, the update mechanism MUST preserve application private data and application 10501shared data. Note that the upstream Android software includes an update 10502mechanism that satisfies this requirement. 10503 </p> 10504 <p> 10505 For device implementations that are launching with Android 7.0 and 10506later, the update mechanism SHOULD support verifying that the system image is 10507binary identical to expected result following an OTA. The block-based OTA 10508implementation in the upstream Android Open Source Project, added since Android 105095.1, satisfies this requirement. 10510 </p> 10511 <p> 10512 If an error is found in a device implementation after it has been released but 10513within its reasonable product lifetime that is determined in consultation with 10514the Android Compatibility Team to affect the compatibility of third-party 10515applications, the device implementer MUST correct the error via a software 10516update available that can be applied per the mechanism just described. 10517 </p> 10518 <p> 10519 Android includes features that allow the Device Owner app (if present) to 10520control the installation of system updates. To facilitate this, the system 10521update subsystem for devices that report android.software.device_admin MUST 10522implement the behavior described in the 10523 <a href="http://developer.android.com/reference/android/app/admin/SystemUpdatePolicy.html">SystemUpdatePolicy</a> class. 10524 </p> 10525 <h1 id="12_document_changelog"> 10526 12. Document Changelog 10527 </h1> 10528 <p> 10529 For a summary of changes to the Compatibility Definition in this release: 10530 </p> 10531 <ul> 10532 <li> 10533 <a href="https://android.googlesource.com/platform/compatibility/cdd/+log/nougat-dev/?pretty=full&no-merges">Document changelog</a> </li> 10534 </ul> 10535 <p> 10536 For a summary of changes to individuals sections: 10537 </p> 10538 <ol> 10539 <li> 10540 <a href="https://android.googlesource.com/platform/compatibility/cdd/+log/nougat-dev/1_introduction?pretty=full&no-merges">Introduction</a> </li> 10541 <li> 10542 <a href="https://android.googlesource.com/platform/compatibility/cdd/+log/nougat-dev/2_device_types?pretty=full&no-merges">Device Types</a> </li> 10543 <li> 10544 <a href="https://android.googlesource.com/platform/compatibility/cdd/+log/nougat-dev/3_software?pretty=full&no-merges">Software</a> </li> 10545 <li> 10546 <a href="https://android.googlesource.com/platform/compatibility/cdd/+log/nougat-dev/4_application-packaging?pretty=full&no-merges">Application Packaging</a> </li> 10547 <li> 10548 <a href="https://android.googlesource.com/platform/compatibility/cdd/+log/nougat-dev/5_multimedia?pretty=full&no-merges">Multimedia</a> </li> 10549 <li> 10550 <a href="https://android.googlesource.com/platform/compatibility/cdd/+log/nougat-dev/6_dev-tools-and-options?pretty=full&no-merges">Developer Tools and Options</a> </li> 10551 <li> 10552 <a href="https://android.googlesource.com/platform/compatibility/cdd/+log/nougat-dev/7_hardware-compatibility?pretty=full&no-merges">Hardware Compatibility</a> </li> 10553 <li> 10554 <a href="https://android.googlesource.com/platform/compatibility/cdd/+log/nougat-dev/8_performance-and-power?pretty=full&no-merges">Performance and Power</a> </li> 10555 <li> 10556 <a href="https://android.googlesource.com/platform/compatibility/cdd/+log/nougat-dev/9_security-model?pretty=full&no-merges">Security Model</a> </li> 10557 <li> 10558 <a href="https://android.googlesource.com/platform/compatibility/cdd/+log/nougat-dev/10_software-compatibility-testing?pretty=full&no-merges">Software Compatibility Testing</a> </li> 10559 <li> 10560 <a href="https://android.googlesource.com/platform/compatibility/cdd/+log/nougat-dev/11_updatable-software?pretty=full&no-merges">Updatable Software</a> </li> 10561 <li> 10562 <a href="https://android.googlesource.com/platform/compatibility/cdd/+log/nougat-dev/12_document-changelog?pretty=full&no-merges">Document Changelog</a> </li> 10563 <li> 10564 <a href="https://android.googlesource.com/platform/compatibility/cdd/+log/nougat-dev/13_contact-us?pretty=full&no-merges">Contact Us</a> </li> 10565 </ol> 10566 <h2 id="12_1_changelog_viewing_tips"> 10567 12.1. Changelog Viewing Tips 10568 </h2> 10569 <p> 10570 Changes are marked as follows: 10571 </p> 10572 <ul> 10573 <li> 10574 <p> 10575 <strong> 10576 CDD 10577 </strong> 10578 <br/> 10579 Substantive changes to the compatibility requirements. 10580 </p> 10581 </li> 10582 <li> 10583 <p> 10584 <strong> 10585 Docs 10586 </strong> 10587 <br/> 10588 Cosmetic or build related changes. 10589 </p> 10590 </li> 10591 </ul> 10592 <p> 10593 For best viewing, append the 10594 <code> 10595 pretty=full 10596 </code> 10597 and 10598 <code> 10599 no-merges 10600 </code> 10601 URL parameters to your 10602changelog URLs. 10603 </p> 10604 <h1 id="13_contact_us"> 10605 13. Contact Us 10606 </h1> 10607 <p> 10608 You can join the 10609 <a href="https://groups.google.com/forum/#!forum/android-compatibility"> 10610 android-compatibility forum</a> and ask 10611for clarifications or bring up any issues that you think the document does not 10612cover. 10613 </p> 10614 </div> 10615 </body> 10616</html> 10617
