1<!DOCTYPE html> 2<head> 3<title>Android 6.0 Compatibility Definition</title> 4<link rel="stylesheet" type="text/css" href="android-cdd.css"/> 5</head> 6 7<body> 8<h1>Android 6.0 Compatibility Definition</h1> 9 10<h6>Table of Contents</h6> 11 12<div id="toc"> 13 14<div id="toc_left"> 15 16<p class="toc_h1"><a href="#1_introduction">1. Introduction</a></p> 17 18<p class="toc_h1"><a href="#2_device_types">2. Device Types</a></p> 19 20<p class="toc_h2"><a href="#2_1_device_configurations">2.1 Device Configurations</a></p> 21 22<p class="toc_h1"><a href="#3_software">3. Software</a></p> 23 24<p class="toc_h2"><a href="#3_1_managed_api_compatibility">3.1. Managed API Compatibility</a></p> 25 26<p class="toc_h2"><a href="#3_2_soft_api_compatibility">3.2. Soft API Compatibility</a></p> 27 28<p class="toc_h3"><a href="#3_2_1_permissions">3.2.1. Permissions</a></p> 29 30<p class="toc_h3"><a href="#3_2_2_build_parameters">3.2.2. Build Parameters</a></p> 31 32<p class="toc_h3"><a href="#3_2_3_intent_compatibility">3.2.3. Intent Compatibility</a></p> 33 34<p class="toc_h4"><a href="#3_2_3_1_core_application_intents">3.2.3.1. Core Application Intents</a></p> 35 36<p class="toc_h4"><a href="#3_2_3_2_intent_resolution">3.2.3.2. Intent Resolution</a></p> 37 38<p class="toc_h4"><a href="#3_2_3_3_intent_namespaces">3.2.3.3. Intent Namespaces</a></p> 39 40<p class="toc_h4"><a href="#3_2_3_4_broadcast_intents">3.2.3.4. Broadcast Intents</a></p> 41 42<p class="toc_h4"><a href="#3_2_3_5_default_app_settings">3.2.3.5. Default App Settings</a></p> 43 44<p class="toc_h2"><a href="#3_3_native_api_compatibility">3.3. Native API Compatibility</a></p> 45 46<p class="toc_h3"><a href="#3_3_1_application_binary_interfaces">3.3.1. Application Binary Interfaces</a></p> 47 48<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> 49 50<p class="toc_h2"><a href="#3_4_web_compatibility">3.4. Web Compatibility</a></p> 51 52<p class="toc_h3"><a href="#3_4_1_webview_compatibility">3.4.1. WebView Compatibility</a></p> 53 54<p class="toc_h3"><a href="#3_4_2_browser_compatibility">3.4.2. Browser Compatibility</a></p> 55 56<p class="toc_h2"><a href="#3_5_api_behavioral_compatibility">3.5. API Behavioral Compatibility</a></p> 57 58<p class="toc_h2"><a href="#3_6_api_namespaces">3.6. API Namespaces</a></p> 59 60<p class="toc_h2"><a href="#3_7_runtime_compatibility">3.7. Runtime Compatibility</a></p> 61 62<p class="toc_h2"><a href="#3_8_user_interface_compatibility">3.8. User Interface Compatibility</a></p> 63 64<p class="toc_h3"><a href="#3_8_1_launcher_home_screen">3.8.1. Launcher (Home Screen)</a></p> 65 66<p class="toc_h3"><a href="#3_8_2_widgets">3.8.2. Widgets</a></p> 67 68<p class="toc_h3"><a href="#3_8_3_notifications">3.8.3. Notifications</a></p> 69 70<p class="toc_h3"><a href="#3_8_4_search">3.8.4. Search</a></p> 71 72<p class="toc_h3"><a href="#3_8_5_toasts">3.8.5. Toasts</a></p> 73 74<p class="toc_h3"><a href="#3_8_6_themes">3.8.6. Themes</a></p> 75 76<p class="toc_h3"><a href="#3_8_7_live_wallpapers">3.8.7. Live Wallpapers</a></p> 77 78<p class="toc_h3"><a href="#3_8_8_activity_switching">3.8.8. Activity Switching</a></p> 79 80<p class="toc_h3"><a href="#3_8_9_input_management">3.8.9. Input Management</a></p> 81 82<p class="toc_h3"><a href="#3_8_10_lock_screen_media_control">3.8.10. Lock Screen Media Control</a></p> 83 84<p class="toc_h3"><a href="#3_8_11_dreams">3.8.11. Dreams</a></p> 85 86<p class="toc_h3"><a href="#3_8_12_location">3.8.12. Location</a></p> 87 88</div> 89 90<div id="toc_right"> 91 92 93<p class="toc_h3"><a href="#3_8_13_unicode_and_font">3.8.13. Unicode and Font</a></p> 94 95<p class="toc_h2"><a href="#3_9_device_administration">3.9. Device Administration</a></p> 96 97<p class="toc_h3"><a href="#3_9_1_device_provisioning">3.9.1 Device Provisioning</a></p> 98 99<p class="toc_h4"><a href="#3_9_1_2_device_owner_provisioning">3.9.1.1 Device Owner provisioning</a></p> 100 101<p class="toc_h4"><a href="#3_9_1_2_managed_profile_provisioning">3.9.1.2 Managed profile provisioning</a></p> 102 103<p class="toc_h3"><a href="#3_9_2_managed_profile_support">3.9.2. Managed Profile Support</a></p> 104 105 106<p class="toc_h2"><a href="#3_10_accessibility">3.10. Accessibility</a></p> 107 108<p class="toc_h2"><a href="#3_11_text-to-speech">3.11. Text-to-Speech</a></p> 109 110<p class="toc_h2"><a href="#3_12_tv_input_framework">3.12. TV Input Framework</a></p> 111 112<p class="toc_h3"><a href="#3_12_1_tv_app">3.12.1. TV App</a></p> 113 114<p class="toc_h4"><a href="#3_12_1_1_electronic_program_guide">3.12.1.1. Electronic Program Guide</a></p> 115 116<p class="toc_h4"><a href="#3_12_1_2_navigation">3.12.1.2. Navigation</a></p> 117 118<p class="toc_h4"><a href="#3_12_1_3_tv_input_app_linking">3.12.1.3. TV input app linking</a></p> 119 120<p class="toc_h1"><a href="#4_application_packaging_compatibility">4. Application Packaging Compatibility</a></p> 121 122<p class="toc_h1"><a href="#5_multimedia_compatibility">5. Multimedia Compatibility</a></p> 123 124<p class="toc_h2"><a href="#5_1_media_codecs">5.1. Media Codecs</a></p> 125 126<p class="toc_h3"><a href="#5_1_1_audio_codecs">5.1.1. Audio Codecs</a></p> 127 128<p class="toc_h3"><a href="#5_1_2_image_codecs">5.1.2. Image Codecs</a></p> 129 130<p class="toc_h3"><a href="#5_1_3_video_codecs">5.1.3. Video Codecs</a></p> 131 132<p class="toc_h2"><a href="#5_2_video_encoding">5.2. Video Encoding</a></p> 133 134<p class="toc_h2"><a href="#5_3_video_decoding">5.3. Video Decoding</a></p> 135 136<p class="toc_h2"><a href="#5_4_audio_recording">5.4. Audio Recording</a></p> 137 138<p class="toc_h3"><a href="#5_4_1_raw_audio_capture">5.4.1. Raw Audio Capture</a></p> 139 140<p class="toc_h3"><a href="#5_4_2_capture_for_voice_recognition">5.4.2. Capture for Voice Recognition</a></p> 141 142<p class="toc_h3"><a href="#5_4_3_capture_for_rerouting_of_playback">5.4.3. Capture for Rerouting of Playback</a></p> 143 144<p class="toc_h2"><a href="#5_5_audio_playback">5.5. Audio Playback</a></p> 145 146<p class="toc_h3"><a href="#5_5_1_raw_audio_playback">5.5.1. Raw Audio Playback</a></p> 147 148<p class="toc_h3"><a href="#5_5_2_audio_effects">5.5.2. Audio Effects</a></p> 149 150<p class="toc_h3"><a href="#5_5_3_audio_output_volume">5.5.3. Audio Output Volume</a></p> 151 152<p class="toc_h2"><a href="#5_6_audio_latency">5.6. Audio Latency</a></p> 153 154<p class="toc_h2"><a href="#5_7_network_protocols">5.7. Network Protocols</a></p> 155 156<p class="toc_h2"><a href="#5_8_secure_media">5.8. Secure Media</a></p> 157 158<p class="toc_h2"><a href="#5_9_midi">5.9. Musical Instrument Digital Interface (MIDI)</a></p> 159 160<p class="toc_h2"><a href="#5_10_pro_audio">5.10. Professional Audio</a></p> 161 162</div> 163 164<div style="clear: both; page-break-after:always; height:1px"></div> 165 166<div id="toc_left"> 167 168<p class="toc_h1"><a href="#6_developer_tools_and_options_compatibility">6. Developer Tools and Options Compatibility</a></p> 169 170<p class="toc_h2"><a href="#6_1_developer_tools">6.1. Developer Tools</a></p> 171 172<p class="toc_h2"><a href="#6_2_developer_options">6.2. Developer Options</a></p> 173 174<p class="toc_h1"><a href="#7_hardware_compatibility">7. Hardware Compatibility</a></p> 175 176<p class="toc_h2"><a href="#7_1_display_and_graphics">7.1. Display and Graphics</a></p> 177 178<p class="toc_h3"><a href="#7_1_1_screen_configuration">7.1.1. Screen Configuration</a></p> 179 180<p class="toc_h4"><a href="#7_1_1_1_screen_size">7.1.1.1. Screen Size</a></p> 181 182<p class="toc_h4"><a href="#7_1_1_2_screen_aspect_ratio">7.1.1.2. Screen Aspect Ratio</a></p> 183 184<p class="toc_h4"><a href="#7_1_1_3_screen_density">7.1.1.3. Screen Density</a></p> 185 186<p class="toc_h3"><a href="#7_1_2_display_metrics">7.1.2. Display Metrics</a></p> 187 188<p class="toc_h3"><a href="#7_1_3_screen_orientation">7.1.3. Screen Orientation</a></p> 189 190<p class="toc_h3"><a href="#7_1_4_2d_and_3d_graphics_acceleration">7.1.4. 2D and 3D Graphics Acceleration</a></p> 191 192<p class="toc_h3"><a href="#7_1_5_legacy_application_compatibility_mode">7.1.5. Legacy Application Compatibility Mode</a></p> 193 194<p class="toc_h3"><a href="#7_1_6_screen_technology">7.1.6. Screen Technology</a></p> 195 196<p class="toc_h3"><a href="#7_1_7_external_displays">7.1.7. Secondary Displays</a></p> 197 198<p class="toc_h2"><a href="#7_2_input_devices">7.2. Input Devices</a></p> 199 200<p class="toc_h3"><a href="#7_2_1_keyboard">7.2.1. Keyboard</a></p> 201 202<p class="toc_h3"><a href="#7_2_2_non-touch_navigation">7.2.2. Non-touch Navigation</a></p> 203 204<p class="toc_h3"><a href="#7_2_3_navigation_keys">7.2.3. Navigation Keys</a></p> 205 206<p class="toc_h3"><a href="#7_2_4_touchscreen_input">7.2.4. Touchscreen Input</a></p> 207 208<p class="toc_h3"><a href="#7_2_5_fake_touch_input">7.2.5. Fake Touch Input</a></p> 209 210<p class="toc_h3"><a href="#7_2_6_game_controller_support">7.2.6. Game Controller Support</a></p> 211 212<p class="toc_h4"><a href="#7_2_6_1_button_mapping">7.2.6.1. Button Mappings</a></p> 213 214<p class="toc_h3"><a href="#7_2_7_remote_control">7.2.7. Remote Control</a></p> 215 216<p class="toc_h2"><a href="#7_3_sensors">7.3. Sensors</a></p> 217 218<p class="toc_h3"><a href="#7_3_1_accelerometer">7.3.1. Accelerometer</a></p> 219 220<p class="toc_h3"><a href="#7_3_2_magnetometer">7.3.2. Magnetometer</a></p> 221 222<p class="toc_h3"><a href="#7_3_3_gps">7.3.3. GPS</a></p> 223 224</div> 225 226<div id="toc_right"> 227 228<p class="toc_h3"><a href="#7_3_4_gyroscope">7.3.4. Gyroscope</a></p> 229 230<p class="toc_h3"><a href="#7_3_5_barometer">7.3.5. Barometer</a></p> 231 232<p class="toc_h3"><a href="#7_3_6_thermometer">7.3.6. Thermometer</a></p> 233 234<p class="toc_h3"><a href="#7_3_7_photometer">7.3.7. Photometer</a></p> 235 236<p class="toc_h3"><a href="#7_3_8_proximity_sensor">7.3.8. Proximity Sensor</a></p> 237 238<p class="toc_h3"><a href="#7_3_9_hifi_sensors">7.3.9. High Fidelity Sensors</a></p> 239 240<p class="toc_h3"><a href="#7_3_10_fingerprint">7.3.10. Fingerprint Sensor</a></p> 241 242<p class="toc_h2"><a href="#7_4_data_connectivity">7.4. Data Connectivity</a></p> 243 244<p class="toc_h3"><a href="#7_4_1_telephony">7.4.1. Telephony</a></p> 245 246<p class="toc_h3"><a href="#7_4_2_ieee_80211_wi-fi">7.4.2. IEEE 802.11 (Wi-Fi)</a></p> 247 248<p class="toc_h4"><a href="#7_4_2_1_wi-fi_direct">7.4.2.1. Wi-Fi Direct</a></p> 249 250<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> 251 252<p class="toc_h3"><a href="#7_4_3_bluetooth">7.4.3. Bluetooth</a></p> 253 254<p class="toc_h3"><a href="#7_4_4_near-field_communications">7.4.4. Near-Field Communications</a></p> 255 256<p class="toc_h3"><a href="#7_4_5_minimum_network_capability">7.4.5. Minimum Network Capability</a></p> 257 258<p class="toc_h3"><a href="#7_4_6_sync_settings">7.4.6. Sync Settings</a></p> 259 260<p class="toc_h2"><a href="#7_5_cameras">7.5. Cameras</a></p> 261 262<p class="toc_h3"><a href="#7_5_1_rear-facing_camera">7.5.1. Rear-Facing Camera</a></p> 263 264<p class="toc_h3"><a href="#7_5_2_front-facing_camera">7.5.2. Front-Facing Camera</a></p> 265 266<p class="toc_h3"><a href="#7_5_3_external_camera">7.5.3. External Camera</a></p> 267 268<p class="toc_h3"><a href="#7_5_4_camera_api_behavior">7.5.4. Camera API Behavior</a></p> 269 270<p class="toc_h3"><a href="#7_5_5_camera_orientation">7.5.5. Camera Orientation</a></p> 271 272<p class="toc_h2"><a href="#7_6_memory_and_storage">7.6. Memory and Storage</a></p> 273 274<p class="toc_h3"><a href="#7_6_1_minimum_memory_and_storage">7.6.1. Minimum Memory and Storage</a></p> 275 276<p class="toc_h3"><a href="#7_6_2_application_shared_storage">7.6.2. Application Shared Storage</a></p> 277 278<p class="toc_h3"><a href="#7_6_3_adoptable_storage">7.6.3. Adoptable Storage</a></p> 279 280<p class="toc_h2"><a href="#7_7_usb">7.7. USB</a></p> 281 282<p class="toc_h2"><a href="#7_8_audio">7.8. Audio</a></p> 283 284<p class="toc_h3"><a href="#7_8_1_microphone">7.8.1. Microphone</a></p> 285 286<p class="toc_h3"><a href="#7_8_2_audio_output">7.8.2. Audio Output</a></p> 287 288<p class="toc_h4"><a href="#7_8_2_1_analog_audio_ports">7.8.2.1. Analog Audio Ports</a></p> 289 290<p class="toc_h3"><a href="#7_8_3_near_ultrasound">7.8.3. Near-Ultrasound</a></p> 291 292<p class="toc_h1"><a href="#8_performance_power">8. Performance and Power</a></p> 293 294<p class="toc_h2"><a href="#8_1_user_experience_consistency">8.1. User Experience Consistency</a></p> 295 296<p class="toc_h2"><a href="#8_2_file_i_o_access_performance">8.2. File I/O Access Performance</a></p> 297 298<p class="toc_h2"><a href="#8_3_power_saving_modes">8.3. Power-Saving Modes</a></p> 299 300<p class="toc_h2"><a href="#8_4_power_consumption_accounting">8.4. Power Consumption Accounting</a></p> 301 302</div> 303 304<div style="clear: both; page-break-after:always; height:1px"></div> 305 306<div id="toc_left"> 307 308<p class="toc_h1"><a href="#9_security_model_compatibility">9. Security Model Compatibility</a></p> 309 310<p class="toc_h2"><a href="#9_1_permissions">9.1. Permissions</a></p> 311 312<p class="toc_h2"><a href="#9_2_uid_and_process_isolation">9.2. UID and Process Isolation</a></p> 313 314<p class="toc_h2"><a href="#9_3_filesystem_permissions">9.3. Filesystem Permissions</a></p> 315 316<p class="toc_h2"><a href="#9_4_alternate_execution_environments">9.4. Alternate Execution Environments</a></p> 317 318<p class="toc_h2"><a href="#9_5_multi-user_support">9.5. Multi-User Support</a></p> 319 320<p class="toc_h2"><a href="#9_6_premium_sms_warning">9.6. Premium SMS Warning</a></p> 321 322<p class="toc_h2"><a href="#9_7_kernel_security_features">9.7. Kernel Security Features</a></p> 323 324<p class="toc_h2"><a href="#9_8_privacy">9.8. Privacy</a></p> 325 326<p class="toc_h2"><a href="#9_9_full-disk-encryption">9.9. Full-Disk Encryption</a></p> 327 328<p class="toc_h2"><a href="#9_10_verified_boot">9.10. Verified Boot</a></p> 329 330<p class="toc_h2"><a href="#9_11_keys_and_credentials">9.11. Keys and Credentials</a></p> 331 332<p class="toc_h2"><a href="#9_12_data_deletion">9.12. Data Deletion</a></p> 333 334<p class="toc_h1"><a href="#10_software_compatibility_testing">10. Software Compatibility Testing</a></p> 335 336<p class="toc_h2"><a href="#10_1_compatibility_test_suite">10.1. Compatibility Test Suite</a></p> 337 338<p class="toc_h2"><a href="#10_2_cts_verifier">10.2. CTS Verifier</a></p> 339 340<p class="toc_h1"><a href="#11_updatable_software">11. Updatable Software</a></p> 341 342<p class="toc_h1"><a href="#12_document_changelog">12. Document Changelog</a></p> 343 344<p class="toc_h1"><a href="#13_contact_us">13. Contact Us</a></p> 345 346<p class="toc_h1"><a href="#14_resources">14. Resources</a></p> 347 348</div> 349 350</div> 351 352<div style="clear: both"></div> 353 354<div id="main"> 355 356<h1 id="1_introduction">1. Introduction</h1> 357 358 359<p>This document enumerates the requirements that must be met in order for devices 360to be compatible with Android 6.0.</p> 361 362<p>The use of “MUST”, “MUST NOT”, “REQUIRED”, “SHALL”, “SHALL NOT”, “SHOULD”, “SHOULD NOT”, “RECOMMENDED”, “MAY”, and “OPTIONAL” is per the IETF standard 363defined in RFC2119 [<a href="http://www.ietf.org/rfc/rfc2119.txt">Resources, 1</a>].</p> 364 365<p>As used in this document, a “device implementer” or “implementer” is a person 366or organization developing a hardware/software solution running Android 6.0. A 367“device implementation” or “implementation is the hardware/software solution 368so developed.</p> 369 370<p>To be considered compatible with Android 6.0, device implementations MUST meet 371the requirements presented in this Compatibility Definition, including any 372documents incorporated via reference.</p> 373 374<p>Where this definition or the software tests described in <a href="#10_software_compatibility_testing">section 10</a> is silent, ambiguous, or incomplete, it is the responsibility of the device 375implementer to ensure compatibility with existing implementations.</p> 376 377<p>For this reason, the Android Open Source Project [<a href="http://source.android.com/">Resources, 2</a>] is both the reference and preferred implementation of Android. Device 378implementers are STRONGLY RECOMMENDED to base their implementations to the 379greatest extent possible on the “upstream” source code available from the 380Android Open Source Project. While some components can hypothetically be 381replaced with alternate implementations, it is STRONGLY RECOMMENDED to not follow this practice, 382as passing the software tests will become substantially more difficult. It is 383the implementer’s responsibility to ensure full behavioral compatibility with 384the standard Android implementation, including and beyond the Compatibility 385Test Suite. Finally, note that certain component substitutions and 386modifications are explicitly forbidden by this document.</p> 387 388<p>Many of the resources listed in <a href="#14_resources">section 14</a> are derived directly or indirectly from the Android SDK, and will be 389functionally identical to the information in that SDK’s documentation. For any 390case where this Compatibility Definition or the Compatibility Test Suite 391disagrees with the SDK documentation, the SDK documentation is considered 392authoritative. Any technical details provided in the references included in <a href="#14_resources">section 14</a> are considered by inclusion to be part of this Compatibility Definition. </p> 393 394<h1 id="2_device_types">2. Device Types</h1> 395 396 397<p>While the Android Open Source Project has been used in the implementation of a 398variety of device types and form factors, many aspects of the architecture and 399compatibility requirements were optimized for handheld devices. Starting from 400Android 5.0, the Android Open Source Project aims to embrace a wider variety of 401device types as described in this section.</p> 402 403<p><strong>Android Handheld device</strong> refers to an Android device implementation that is typically used by holding 404it in the hand, such as mp3 players, phones, and tablets. Android Handheld 405device implementations:</p> 406 407<ul> 408 <li>MUST have a touchscreen embedded in the device.</li> 409 <li>MUST have a power source that provides mobility, such as a battery.</li> 410</ul> 411 412<p><strong>Android Television device</strong> refers to an Android device implementation that is an entertainment interface 413for consuming digital media, movies, games, apps, and/or live TV for users 414sitting about ten feet away (a “lean back” or “10-foot user interface”). 415Android Television devices:</p> 416 417<ul> 418 <li>MUST have an embedded screen OR include a video output port, such as VGA, HDMI, 419or a wireless port for display.</li> 420 <li>MUST declare the features android.software.leanback and 421android.hardware.type.television [<a href="http://developer.android.com/reference/android/content/pm/PackageManager.html#FEATURE_LEANBACK">Resources, 3</a>].</li> 422</ul> 423 424<p><strong>Android Watch device</strong> refers to an Android device implementation intended to be worn on the body, 425perhaps on the wrist, and:</p> 426 427<ul> 428 <li>MUST have a screen with the physical diagonal length in the range from 1.1 to 4292.5 inches.</li> 430 <li>MUST declare the feature android.hardware.type.watch.</li> 431 <li>MUST support uiMode = UI_MODE_TYPE_WATCH [<a href="http://developer.android.com/reference/android/content/res/Configuration.html#UI_MODE_TYPE_WATCH">Resources, 4</a>].</li> 432</ul> 433 434<p><strong>Android Automotive implementation</strong> refers to a vehicle head 435unit running Android as an operating system for part or all of the system and/or 436infotainment functionality. Android Automotive implementations:</p> 437 438<ul> 439 <li>MUST declare the feature android.hardware.type.automotive.</li> 440 <li>MUST support 441uiMode = UI_MODE_TYPE_CAR [<a 442href="http://developer.android.com/reference/android/content/res/Configuration.html#UI_MODE_TYPE_CAR">Resources, 443 5</a>].</li> 444</ul> 445 446<p>All Android device implementations that do not fit into any of the above device 447types still MUST meet all requirements in this document to be Android 6.0 448compatible, unless the requirement is explicitly described to be only 449applicable to a specific Android device type from above.</p> 450 451<h2 id="2_1_device_configurations">2.1 Device Configurations</h2> 452 453 454<p>This is a summary of major differences in hardware configuration by device 455type. (Empty cells denote a “MAY”). Not all configurations are covered in this 456table; see relevant hardware sections for more detail.</p> 457<table> 458 <tr> 459 <th>Category</th> 460 <th>Feature</th> 461 <th>Section</th> 462 <th>Handheld</th> 463 <th>Television</th> 464 <th>Watch</th> 465 <th>Automotive</th> 466 <th>Other</th> 467 </tr> 468 <tr> 469 <td rowspan="3">Input</td> 470 <td>D-pad</td> 471 <td><a href="#7_2_2_non-touch-navigation">7.2.2. Non-touch Navigation</a></td> 472 <td></td> 473 <td>MUST</td> 474 <td></td> 475 <td></td> 476 <td></td> 477 </tr> 478 <tr> 479 <td>Touchscreen </td> 480 <td><a href="#7_2_4_touchscreen_input">7.2.4. Touchscreen input</a></td> 481 <td>MUST</td> 482 <td></td> 483 <td>MUST</td> 484 <td></td> 485 <td>SHOULD</td> 486 </tr> 487 <tr> 488 <td>Microphone </td> 489 <td><a href="#7_8_1_microphone">7.8.1. Microphone</a></td> 490 <td>MUST</td> 491 <td>SHOULD </td> 492 <td>MUST</td> 493 <td>MUST</td> 494 <td>SHOULD</td> 495 </tr> 496 <tr> 497 <td rowspan="2">Sensors</td> 498 <td>Accelerometer </td> 499 <td><a href="#7_3_1_accelerometer">7.3.1 Accelerometer</a></td> 500 <td>SHOULD</td> 501 <td></td> 502 <td>SHOULD</td> 503 <td></td> 504 <td>SHOULD</td> 505 </tr> 506 <tr> 507 <td>GPS</td> 508 <td><a href="#7_3_3_gps">7.3.3. GPS</a></td> 509 <td>SHOULD</td> 510 <td></td> 511 <td></td> 512 <td>SHOULD</td> 513 <td></td> 514 </tr> 515 <tr> 516 <td rowspan="5">Connectivity</td> 517 <td>Wi-Fi</td> 518 <td><a href="#7_4_2_ieee_802.11">7.4.2. IEEE 802.11</a></td> 519 <td>SHOULD</td> 520 <td> MUST</td> 521 <td></td> 522 <td>SHOULD</td> 523 <td>SHOULD</td> 524 </tr> 525 <tr> 526 <td>Wi-Fi Direct</td> 527 <td><a href="#7_4_2_1_wi-fi-direct">7.4.2.1. Wi-Fi Direct</a></td> 528 <td>SHOULD</td> 529 <td>SHOULD</td> 530 <td></td> 531 <td></td> 532 <td>SHOULD</td> 533 </tr> 534 <tr> 535 <td>Bluetooth</td> 536 <td><a href="#7_4_3_bluetooth">7.4.3. Bluetooth</a></td> 537 <td>SHOULD</td> 538 <td>MUST</td> 539 <td>MUST</td> 540 <td>MUST</td> 541 <td>SHOULD</td> 542 </tr> 543 <tr> 544 <td>Bluetooth Low Energy</td> 545 <td><a href="#7_4_3_bluetooth">7.4.3. Bluetooth</a></td> 546 <td>SHOULD</td> 547 <td>MUST</td> 548 <td>SHOULD</td> 549 <td>SHOULD</td> 550 <td>SHOULD</td> 551 </tr> 552 <tr> 553 <td>USB peripheral/host mode</td> 554 <td><a href="#7_7_usb">7.7. USB</a></td> 555 <td>SHOULD</td> 556 <td></td> 557 <td></td> 558 <td>SHOULD</td> 559 <td>SHOULD</td> 560 </tr> 561 <tr> 562 <td>Output</td> 563 <td>Speaker and/or Audio output ports</td> 564 <td><a href="#7_8_2_audio_output">7.8.2. Audio Output</a></td> 565 <td>MUST</td> 566 <td>MUST</td> 567 <td></td> 568 <td>MUST</td> 569 <td>MUST</td> 570 </tr> 571</table> 572 573 574<h1 id="3_software">3. Software</h1> 575 576 577<h2 id="3_1_managed_api_compatibility">3.1. Managed API Compatibility</h2> 578 579 580<p>The managed Dalvik bytecode execution environment is the primary vehicle for 581Android applications. The Android application programming interface (API) is 582the set of Android platform interfaces exposed to applications running in the 583managed runtime environment. Device implementations MUST provide complete 584implementations, including all documented behaviors, of any documented API 585exposed by the Android SDK [<a href="http://developer.android.com/reference/packages.html">Resources, 6</a>] or any API decorated with the “@SystemApi” marker in the upstream Android 586source code. </p> 587 588<p>Device implementations MUST NOT omit any managed APIs, alter API interfaces or 589signatures, deviate from the documented behavior, or include no-ops, except 590where specifically allowed by this Compatibility Definition.</p> 591 592<p>This Compatibility Definition permits some types of hardware for which Android 593includes APIs to be omitted by device implementations. In such cases, the APIs 594MUST still be present and behave in a reasonable way. See <a href="#7_hardware_compatibility">section 7</a> for specific requirements for this scenario.</p> 595 596<h2 id="3_2_soft_api_compatibility">3.2. Soft API Compatibility</h2> 597 598 599<p>In addition to the managed APIs from <a href="#3_1_managed_api_compatibility">section 3.1</a>, Android also includes a significant runtime-only “soft” API, in the form of 600such things as intents, permissions, and similar aspects of Android 601applications that cannot be enforced at application compile time.</p> 602 603<h3 id="3_2_1_permissions">3.2.1. Permissions</h3> 604 605 606<p>Device implementers MUST support and enforce all permission constants as 607documented by the Permission reference page [<a href="http://developer.android.com/reference/android/Manifest.permission.html">Resources, 7</a>]. Note that <a href="#9_security_model_compatibility">section 9</a> lists additional requirements related to the Android security model.</p> 608 609<h3 id="3_2_2_build_parameters">3.2.2. Build Parameters</h3> 610 611 612<p>The Android APIs include a number of constants on the android.os.Build class [<a href="http://developer.android.com/reference/android/os/Build.html">Resources, 8</a>] that are intended to describe the current device. To provide consistent, 613meaningful values across device implementations, the table below includes 614additional restrictions on the formats of these values to which device 615implementations MUST conform.</p> 616<table> 617 <tr> 618 <th>Parameter</th> 619 <th>Details</th> 620 </tr> 621 <tr> 622 <td>VERSION.RELEASE</td> 623 <td>The version of the currently-executing Android system, in human-readable 624format. This field MUST have one of the string values defined in [<a href="http://source.android.com/compatibility/6.0/versions.html">Resources, 9</a>].</td> 625 </tr> 626 <tr> 627 <td>VERSION.SDK</td> 628 <td>The version of the currently-executing Android system, in a format accessible 629to third-party application code. For Android 6.0, this field MUST have the 630integer value 23.</td> 631 </tr> 632 <tr> 633 <td>VERSION.SDK_INT</td> 634 <td>The version of the currently-executing Android system, in a format accessible 635to third-party application code. For Android 6.0, this field MUST have the 636integer value 23.</td> 637 </tr> 638 <tr> 639 <td>VERSION.INCREMENTAL</td> 640 <td>A value chosen by the device implementer designating the specific build of the 641currently-executing Android system, in human-readable format. This value MUST 642NOT be reused for different builds made available to end users. A typical use 643of this field is to indicate which build number or source-control change 644identifier was used to generate the build. There are no requirements on the 645specific format of this field, except that it MUST NOT be null or the empty 646string ("").</td> 647 </tr> 648 <tr> 649 <td>BOARD</td> 650 <td>A value chosen by the device implementer identifying the specific internal 651hardware used by the device, in human-readable format. A possible use of this 652field is to indicate the specific revision of the board powering the device. 653The value of this field MUST be encodable as 7-bit ASCII and match the regular 654expression “^[a-zA-Z0-9_-]+$”.</td> 655 </tr> 656 <tr> 657 <td>BRAND</td> 658 <td>A value reflecting the brand name associated with the device as known to the 659end users. MUST be in human-readable format and SHOULD represent the 660manufacturer of the device or the company brand under which the device is 661marketed. The value of this field MUST be encodable as 7-bit ASCII and match 662the regular expression “^[a-zA-Z0-9_-]+$”.</td> 663 </tr> 664 <tr> 665 <td>SUPPORTED_ABIS</td> 666 <td>The name of the instruction set (CPU type + ABI convention) of native code. See <a href="#3_3_native_api_compatibility">section 3.3. Native API Compatibility</a>.</td> 667 </tr> 668 <tr> 669 <td>SUPPORTED_32_BIT_ABIS</td> 670 <td>The name of the instruction set (CPU type + ABI convention) of native code. See <a href="#3_3_native_api_compatibility">section 3.3. Native API Compatibility</a>.</td> 671 </tr> 672 <tr> 673 <td>SUPPORTED_64_BIT_ABIS</td> 674 <td>The name of the second instruction set (CPU type + ABI convention) of native 675code. See <a href="#3_3_native_api_compatibility">section 3.3. Native API Compatibility</a>.</td> 676 </tr> 677 <tr> 678 <td>CPU_ABI</td> 679 <td>The name of the instruction set (CPU type + ABI convention) of native code. See <a href="#3_3_native_api_compatibility">section 3.3. Native API Compatibility</a>.</td> 680 </tr> 681 <tr> 682 <td>CPU_ABI2</td> 683 <td>The name of the second instruction set (CPU type + ABI convention) of native 684code. See <a href="#3_3_native_api_compatibility">section 3.3. Native API Compatibility</a>.</td> 685 </tr> 686 <tr> 687 <td>DEVICE</td> 688 <td>A value chosen by the device implementer containing the development name or 689code name identifying the configuration of the hardware features and industrial 690design of the device. The value of this field MUST be encodable as 7-bit ASCII 691and match the regular expression “^[a-zA-Z0-9_-]+$”.</td> 692 </tr> 693 <tr> 694 <td>FINGERPRINT</td> 695 <td>A string that uniquely identifies this build. It SHOULD be reasonably 696human-readable. It MUST follow this template: 697<p class="small">$(BRAND)/$(PRODUCT)/<br> 698 $(DEVICE):$(VERSION.RELEASE)/$(ID)/$(VERSION.INCREMENTAL):$(TYPE)/$(TAGS)</p> 699<p>For example:</p> 700<p class="small">acme/myproduct/<br> 701 mydevice:6.0/LMYXX/3359:userdebug/test-keys</p> 702<p>The fingerprint MUST NOT include whitespace characters. If other fields 703included in the template above have whitespace characters, they MUST be 704replaced in the build fingerprint with another character, such as the 705underscore ("_") character. The value of this field MUST be encodable as 7-bit 706ASCII.</p></td> 707 </tr> 708 <tr> 709 <td>HARDWARE</td> 710 <td>The name of the hardware (from the kernel command line or /proc). It SHOULD be 711reasonably human-readable. The value of this field MUST be encodable as 7-bit 712ASCII and match the regular expression “^[a-zA-Z0-9_-]+$”. </td> 713 </tr> 714 <tr> 715 <td>HOST</td> 716 <td>A string that uniquely identifies the host the build was built on, in 717human-readable format. There are no requirements on the specific format of this 718field, except that it MUST NOT be null or the empty string ("").</td> 719 </tr> 720 <tr> 721 <td>ID</td> 722 <td>An identifier chosen by the device implementer to refer to a specific release, 723in human-readable format. This field can be the same as 724android.os.Build.VERSION.INCREMENTAL, but SHOULD be a value sufficiently 725meaningful for end users to distinguish between software builds. The value of 726this field MUST be encodable as 7-bit ASCII and match the regular expression “^[a-zA-Z0-9._-]+$”.</td> 727 </tr> 728 <tr> 729 <td>MANUFACTURER</td> 730 <td>The trade name of the Original Equipment Manufacturer (OEM) of the product. 731There are no requirements on the specific format of this field, except that it 732MUST NOT be null or the empty string ("").</td> 733 </tr> 734 <tr> 735 <td>MODEL</td> 736 <td>A value chosen by the device implementer containing the name of the device as 737known to the end user. This SHOULD be the same name under which the device is 738marketed and sold to end users. There are no requirements on the specific 739format of this field, except that it MUST NOT be null or the empty string ("").</td> 740 </tr> 741 <tr> 742 <td>PRODUCT</td> 743 <td>A value chosen by the device implementer containing the development name or 744code name of the specific product (SKU) that MUST be unique within the same 745brand. MUST be human-readable, but is not necessarily intended for view by end 746users. The value of this field MUST be encodable as 7-bit ASCII and match the 747regular expression “^[a-zA-Z0-9_-]+$”.</td> 748 </tr> 749 <tr> 750 <td>SERIAL</td> 751 <td>A hardware serial number, which MUST be available and unique across 752devices with the same MODEL and MANUFACTURER. The value of this field MUST 753be encodable as 7-bit ASCII and match the regular expression “^([a-zA-Z0-9]{6,20})$”.</td> 754 </tr> 755 <tr> 756 <td>TAGS</td> 757 <td>A comma-separated list of tags chosen by the device implementer that further 758distinguishes the build. This field MUST have one of the values corresponding 759to the three typical Android platform signing configurations: release-keys, 760dev-keys, test-keys. </td> 761 </tr> 762 <tr> 763 <td>TIME</td> 764 <td>A value representing the timestamp of when the build occurred.</td> 765 </tr> 766 <tr> 767 <td>TYPE</td> 768 <td>A value chosen by the device implementer specifying the runtime configuration 769of the build. This field MUST have one of the values corresponding to the three 770typical Android runtime configurations: user, userdebug, or eng.</td> 771 </tr> 772 <tr> 773 <td>USER</td> 774 <td>A name or user ID of the user (or automated user) that generated the build. 775There are no requirements on the specific format of this field, except that it 776MUST NOT be null or the empty string ("").</td> 777 </tr> 778 <tr> 779 <td>SECURITY_PATCH</td> 780 <td>A value indicating the security patch level of a build. It MUST signify that the 781build includes all security patches issued up through the designated Android Public 782Security Bulletin. It MUST be in the format, [YYYY-MM-DD], matching one of the Android 783Security Patch Level strings of the <a href="source.android.com/security/bulletin"> Public 784Security Bulletins</a>, for example "2015-11-01".</td> 785 </tr> 786 <tr> 787 <td>BASE_OS</td> 788 <td>A value representing the FINGERPRINT parameter of the build that is otherwise 789 identical to this build except for the patches provided in the Android Public 790 Security Bulletin. It MUST report the correct value and if such a build does not 791 exist, report an emtpy string ("").</td> 792 </tr> 793</table> 794 795 796<h3 id="3_2_3_intent_compatibility">3.2.3. Intent Compatibility</h3> 797 798 799<p>Device implementations MUST honor Android’s loose-coupling intent system, as 800described in the sections below. By“honored ” it is meant that the device 801implementer MUST provide an Android Activity or Service that specifies a 802matching intent filter that binds to and implements correct behavior for each 803specified intent pattern.</p> 804 805<h4 id="3_2_3_1_core_application_intents">3.2.3.1. Core Application Intents</h4> 806 807 808<p>Android intents allow application components to request functionality from 809other Android components. The Android upstream project includes a list of 810applications considered core Android applications, which implements several 811intent patterns to perform common actions. The core Android applications are:</p> 812 813<ul> 814 <li>Desk Clock</li> 815 <li>Browser</li> 816 <li>Calendar</li> 817 <li>Contacts</li> 818 <li>Gallery</li> 819 <li>GlobalSearch</li> 820 <li>Launcher</li> 821 <li>Music</li> 822 <li>Settings</li> 823</ul> 824 825<p>Device implementations SHOULD include the core Android applications as 826appropriate but MUST include a component implementing the same intent patterns 827defined by all the “public” Activity or Service components of these core 828Android applications. Note that Activity or Service components are considered 829“public” when the attribute android:exported is absent or has the value true.</p> 830 831<h4 id="3_2_3_2_intent_resolution">3.2.3.2. Intent Resolution</h4> 832 833 834<p>As Android is an extensible platform, device implementations MUST allow each 835intent pattern referenced in <a href="#3_2_3_1_core_application_intents">section 3.2.3.1</a> 836to be overridden by third-party applications. The upstream Android open source 837implementation allows this by default; device implementers MUST NOT attach 838special privileges to system applications' use of these intent patterns, or 839prevent third-party applications from binding to and assuming control of these 840patterns. This prohibition specifically includes but is not limited to 841disabling the“Chooser” user interface that allows the user to select between 842multiple applications that all handle the same intent pattern.</p> 843 844<p>Device implementations MUST provide a user interface for users to modify the default 845activity for intents.</p> 846 847<p>However, device implementations MAY provide default activities for specific URI 848patterns (eg. http://play.google.com) when the default activity provides a more 849specific attribute for the data URI. For example, an intent filter pattern specifying 850the data URI “http://www.android.com” is more specific than the browser's 851core intent pattern for “http://”.</p> 852 853<p>Android also includes a mechanism for third-party apps to declare an authoritative 854default app linking behavior for certain types of web URI intents [<a 855href="https://developer.android.com/training/app-links">Resources, 140</a>]. When such 856authoritative declarations are defined in an app's intent filter patterns, device 857implementations:</p> 858 859<ul> 860<li>MUST attempt to validate any intent filters by performing the validation steps 861defined in the Digital Asset Links specification [<a 862href="https://developers.google.com/digital-asset-links">Resources, 141</a>] as implemented 863by the Package Manager in the upstream Android Open Source Project.</li> 864<li>MUST attempt validation of the intent filters during the installation of the 865application and set all successfully validated UIR intent filters as default app handlers 866for their UIRs.</li> 867<li>MAY set specific URI intent filters as default app handlers for their URIs, if they 868are successfully verified but other candidate URI filters fail verification. If a device 869implementation does this, it MUST provide the user appropriate per-URI pattern overrides 870in the settings menu.</li> 871<li>MUST provide the user with per-app App Links controls in Settings as follows: 872 <ul> 873 <li>The user MUST be able to override holistically the default app links behavior for 874 an app to be: always open, always ask, or never open, which must apply to all candidate 875 URI intent filters equally.</li> 876 <li>The user MUST be able to see a list of the candidate URI intent filters.</li> 877 <li>The device implementation MAY provide the user with the ability to override specific 878 candidate URI intent filters that were successfully verified, on a per-intent filter basis. 879 </li> 880 <li>The device implementation MUST provide users with the ability to view and override 881 specific candidate URI intent filters if the device implementation lets some candidate 882 URI intent filters succeed verification while some others can fail.</li> 883 </ul> 884</li> 885</ul> 886 887<h4 id="3_2_3_3_intent_namespaces">3.2.3.3. Intent Namespaces</h4> 888 889 890<p>Device implementations MUST NOT include any Android component that honors any 891new intent or broadcast intent patterns using an ACTION, CATEGORY, or other key 892string in the android.* or com.android.* namespace. Device implementers MUST 893NOT include any Android components that honor any new intent or broadcast 894intent patterns using an ACTION, CATEGORY, or other key string in a package 895space belonging to another organization. Device implementers MUST NOT alter or 896extend any of the intent patterns used by the core apps listed in <a href="#3_2_3_1_core_application_intents">section 3.2.3.1</a>. Device implementations MAY include intent patterns using namespaces clearly 897and obviously associated with their own organization. This prohibition is 898analogous to that specified for Java language classes in <a href="#3_6_api_namespaces">section 3.6</a>.</p> 899 900<h4 id="3_2_3_4_broadcast_intents">3.2.3.4. Broadcast Intents</h4> 901 902 903<p>Third-party applications rely on the platform to broadcast certain intents to 904notify them of changes in the hardware or software environment. 905Android-compatible devices MUST broadcast the public broadcast intents in 906response to appropriate system events. Broadcast intents are described in the 907SDK documentation.</p> 908 909<h4 id="3_2_3_5_default_app_settings">3.2.3.5. Default App Settings</h4> 910 911 912<p>Android includes settings that provide users an easy way to select their 913default applications, for example for Home screen or SMS. Where it makes sense, 914device implementations MUST provide a similar settings menu and be compatible 915with the intent filter pattern and API methods described in the SDK 916documentation as below.</p> 917 918<p>Device implementations:</p> 919 920<ul> 921 <li>MUST honor the android.settings.HOME_SETTINGS intent to show a default app 922settings menu for Home Screen, if the device implementation reports 923android.software.home_screen [<a href="http://developer.android.com/reference/android/provider/Settings.html">Resources, 10</a>]</li> 924 <li>MUST provide a settings menu that will call the 925android.provider.Telephony.ACTION_CHANGE_DEFAULT intent to show a dialog to 926change the default SMS application, if the device implementation reports 927android.hardware.telephony [<a href="http://developer.android.com/reference/android/provider/Telephony.Sms.Intents.html">Resources, 11</a>]</li> 928 <li>MUST honor the android.settings.NFC_PAYMENT_SETTINGS intent to show a default 929app settings menu for Tap and Pay, if the device implementation reports 930android.hardware.nfc.hce [<a href="http://developer.android.com/reference/android/provider/Settings.html">Resources, 10</a>]</li> 931</ul> 932 933<h2 id="3_3_native_api_compatibility">3.3. Native API Compatibility</h2> 934 935 936<h3 id="3_3_1_application_binary_interfaces">3.3.1. Application Binary Interfaces</h3> 937 938 939<p>Managed Dalvik bytecode can call into native code provided in the application 940.apk file as an ELF .so file compiled for the appropriate device hardware 941architecture. As native code is highly dependent on the underlying processor 942technology, Android defines a number of Application Binary Interfaces (ABIs) in 943the Android NDK. Device implementations MUST be compatible with one or more 944defined ABIs, and MUST implement compatibility with the Android NDK, as below.</p> 945 946<p>If a device implementation includes support for an Android ABI, it:</p> 947 948<ul> 949 <li>MUST include support for code running in the managed environment to call into 950native code, using the standard Java Native Interface (JNI) semantics</li> 951 <li>MUST be source-compatible (i.e. header compatible) and binary-compatible (for 952the ABI) with each required library in the list below</li> 953 <li>MUST support the equivalent 32-bit ABI if any 64-bit ABI is supported</li> 954 <li>MUST accurately report the native Application Binary Interface (ABI) supported 955by the device, via the android.os.Build.SUPPORTED_ABIS, 956android.os.Build.SUPPORTED_32_BIT_ABIS, and 957android.os.Build.SUPPORTED_64_BIT_ABIS parameters, each a comma separated list 958of ABIs ordered from the most to the least preferred one</li> 959 <li>MUST report, via the above parameters, only those ABIs documented and 960described in the latest version of the Android NDK ABI Management documentation 961[<a href="https://developer.android.com/ndk/guides/abis.html">Resources, 12</a>], 962and MUST include support for the Advanced SIMD (a.k.a. NEON) 963[<a href="http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.ddi0388f/Beijfcja.html">Resources, 13</a>] 964extension 965 </li> 966 <li>SHOULD be built using the source code and header files available in the 967upstream Android Open Source Project</li> 968</ul> 969 970<p>The following native code APIs MUST be available to apps that include native 971code:</p> 972 973<ul> 974 <li>libc (C library)</li> 975 <li>libm (math library)</li> 976 <li>Minimal support for C++</li> 977 <li>JNI interface</li> 978 <li>liblog (Android logging)</li> 979 <li>libz (Zlib compression)</li> 980 <li>libdl (dynamic linker)</li> 981 <li>libGLESv1_CM.so (OpenGL ES 1.x)</li> 982 <li>libGLESv2.so (OpenGL ES 2.0)</li> 983 <li>libGLESv3.so (OpenGL ES 3.x)</li> 984 <li>libEGL.so (native OpenGL surface management)</li> 985 <li>libjnigraphics.so</li> 986 <li>libOpenSLES.so (OpenSL ES 1.0.1 audio support)</li> 987 <li>libOpenMAXAL.so (OpenMAX AL 1.0.1 support)</li> 988 <li>libandroid.so (native Android activity support)</li> 989 <li>libmediandk.so (native media APIs support)</li> 990 <li>Support for OpenGL, as described below</li> 991</ul> 992 993<p>Note that future releases of the Android NDK may introduce support for 994additional ABIs. If a device implementation is not compatible with an existing 995predefined ABI, it MUST NOT report support for any ABIs at all.</p> 996 997<p>Note that device implementations MUST include libGLESv3.so and it MUST symlink 998(symbolic link) to libGLESv2.so. in turn, MUST export all the OpenGL ES 3.1 and 999Android Extension Pack [<a href="http://developer.android.com/guide/topics/graphics/opengl.html#aep">Resources, 14</a>] function symbols as defined in the NDK release android-21. Although all the 1000symbols must be present, only the corresponding functions for OpenGL ES 1001versions and extensions actually supported by the device must be fully 1002implemented.</p> 1003 1004<p>Device implementations, if including a native library with the name libvulkan.so, 1005MUST export function symbols and provide an implementation of the Vulkan 1.0 API 1006and the VK_KHR_surface, VK_KHR_swapchain, and VK_KHR_android_surface extensions 1007as defined by the Khronos Group and passing the Khronos conformance tests.</p> 1008 1009<p>Native code compatibility is challenging. For this reason, device implementers 1010are <strong>STRONGLY RECOMMENDED</strong> to use the implementations of the libraries listed above from the upstream 1011Android Open Source Project. </p> 1012 1013<h3 id="3_3_2_32-bit_arm_native_code_compatibility"> 10143.3.2. 32-bit ARM Native Code Compatibility 1015</h3> 1016 1017<p>The ARMv8 architecture deprecates several CPU operations, including some 1018operations used in existing native code. On 64-bit ARM devices, the following 1019deprecated operations MUST remain available to 32-bit native ARM code, either 1020through native CPU support or through software emulation:</p> 1021 1022<ul> 1023<li>SWP and SWPB instructions</li> 1024<li>SETEND instruction</li> 1025<li>CP15ISB, CP15DSB, and CP15DMB barrier operations</li> 1026</ul> 1027 1028<p>Legacy versions of the Android NDK used /proc/cpuinfo to discover CPU features 1029from 32-bit ARM native code. For compatibility with applications built using this 1030NDK, devices MUST include the following lines in /proc/cpuinfo when it is read 1031by 32-bit ARM applications:</p> 1032 1033<ul> 1034<li>"Features: ", followed by a list of any optional ARMv7 CPU features 1035supported by the device</li> 1036<li>"CPU architecture: ", followed by an integer describing the device's 1037highest supported ARM architecture (e.g., "8" for ARMv8 devices)</li> 1038</ul> 1039 1040<p>These requirements only apply when /proc/cpuinfo is read by 32-bit ARM 1041applications. Devices SHOULD not alter /proc/cpuinfo when read by 64-bit ARM or 1042non-ARM applications.</p> 1043 1044<h2 id="3_4_web_compatibility">3.4. Web Compatibility</h2> 1045 1046 1047<h3 id="3_4_1_webview_compatibility">3.4.1. WebView Compatibility</h3> 1048 1049<div class="note"> 1050<p>Android Watch devices MAY, but all other device implementations MUST provide 1051a complete implementation of the android.webkit.Webview API.</p> 1052</div> 1053 1054 1055<p>The platform feature android.software.webview MUST be reported on any device 1056that provides a complete implementation of the android.webkit.WebView API, and 1057MUST NOT be reported on devices without a complete implementation of the API. 1058The Android Open Source implementation uses code from the Chromium Project to 1059implement the android.webkit.WebView [<a href="http://developer.android.com/reference/android/webkit/WebView.html">Resources, 15</a>]. Because it is not feasible to develop a comprehensive test suite for a web 1060rendering system, device implementers MUST use the specific upstream build of 1061Chromium in the WebView implementation. Specifically:</p> 1062 1063<ul> 1064 <li>Device android.webkit.WebView implementations MUST be based on the Chromium 1065build from the upstream Android Open Source Project for Android 6.0. This build 1066includes a specific set of functionality and security fixes for the WebView [<a href="http://www.chromium.org/">Resources, 16</a>].</li> 1067 <li>The user agent string reported by the WebView MUST be in this format: 1068<p>Mozilla/5.0 (Linux; Android $(VERSION); $(MODEL) Build/$(BUILD); wv) 1069AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 $(CHROMIUM_VER) Mobile 1070Safari/537.36</p> 1071 <ul> 1072 <li>The value of the $(VERSION) string MUST be the same as the value for 1073android.os.Build.VERSION.RELEASE.</li> 1074 <li>The value of the $(MODEL) string MUST be the same as the value for 1075android.os.Build.MODEL.</li> 1076 <li>The value of the $(BUILD) string MUST be the same as the value for 1077android.os.Build.ID.</li> 1078 <li>The value of the $(CHROMIUM_VER) string MUST be the version of Chromium in the 1079upstream Android Open Source Project.</li> 1080 <li>Device implementations MAY omit Mobile in the user agent string.</li> 1081 </ul></li></ul> 1082 1083<p>The WebView component SHOULD include support for as many HTML5 features as 1084possible and if it supports the feature SHOULD conform to the HTML5 1085specification [<a href="http://html.spec.whatwg.org/multipage/">Resources, 17</a>].</p> 1086 1087<h3 id="3_4_2_browser_compatibility">3.4.2. Browser Compatibility</h3> 1088 1089<div class="note"> 1090<p>Android Television, Watch, and Android Automotive implementations MAY omit a 1091browser application, but MUST support the public intent patterns as described in 1092<a href="#3_2_3_1_core_application_intents">section 3.2.3.1</a>. All other types 1093of device implementations MUST include a standalone Browser application for 1094general user web browsing.</p> 1095</div> 1096 1097<p>The standalone Browser MAY be based on a browser technology other than WebKit. 1098However, even if an alternate Browser application is used, the 1099android.webkit.WebView component provided to third-party applications MUST be 1100based on WebKit, as described in <a href="#3_4_1_webview_compatibility">section 3.4.1</a>.</p> 1101 1102<p>Implementations MAY ship a custom user agent string in the standalone Browser 1103application.</p> 1104 1105<p>The standalone Browser application (whether based on the upstream WebKit 1106Browser application or a third-party replacement) SHOULD include support for as 1107much of HTML5 [<a href="http://html.spec.whatwg.org/multipage/">Resources, 17</a>] as possible. Minimally, device implementations MUST support each of these 1108APIs associated with HTML5:</p> 1109 1110<ul> 1111 <li>application cache/offline operation [<a href="http://www.w3.org/html/wg/drafts/html/master/browsers.html#offline">Resources, 18</a>]</li> 1112 <li>the <video> tag [<a href="http://www.w3.org/html/wg/drafts/html/master/semantics.html#video">Resources, 19</a>]</li> 1113 <li>geolocation [<a href="http://www.w3.org/TR/geolocation-API/">Resources, 20</a>]</li> 1114</ul> 1115 1116<p>Additionally, device implementations MUST support the HTML5/W3C webstorage API 1117[<a href="http://www.w3.org/TR/webstorage/">Resources, 21</a>], and SHOULD support the HTML5/W3C IndexedDB API [<a href="http://www.w3.org/TR/IndexedDB/">Resources, 22</a>]. Note that as the web development standards bodies are transitioning to favor 1118IndexedDB over webstorage, IndexedDB is expected to become a required component 1119in a future version of Android.</p> 1120 1121<h2 id="3_5_api_behavioral_compatibility">3.5. API Behavioral Compatibility</h2> 1122 1123 1124<p>The behaviors of each of the API types (managed, soft, native, and web) must be 1125consistent with the preferred implementation of the upstream Android Open 1126Source Project [<a href="http://source.android.com/">Resources, 2</a>]. Some specific areas of compatibility are:</p> 1127 1128<ul> 1129 <li>Devices MUST NOT change the behavior or semantics of a standard intent.</li> 1130 <li>Devices MUST NOT alter the lifecycle or lifecycle semantics of a particular 1131type of system component (such as Service, Activity, ContentProvider, etc.).</li> 1132 <li>Devices MUST NOT change the semantics of a standard permission.</li> 1133</ul> 1134 1135<p>The above list is not comprehensive. The Compatibility Test Suite (CTS) tests 1136significant portions of the platform for behavioral compatibility, but not all. 1137It is the responsibility of the implementer to ensure behavioral compatibility 1138with the Android Open Source Project. For this reason, device implementers 1139SHOULD use the source code available via the Android Open Source Project where 1140possible, rather than re-implement significant parts of the system.</p> 1141 1142<h2 id="3_6_api_namespaces">3.6. API Namespaces</h2> 1143 1144 1145<p>Android follows the package and class namespace conventions defined by the Java 1146programming language. To ensure compatibility with third-party applications, 1147device implementers MUST NOT make any prohibited modifications (see below) to 1148these package namespaces:</p> 1149 1150<ul> 1151 <li>java.*</li> 1152 <li>javax.*</li> 1153 <li>sun.*</li> 1154 <li>android.*</li> 1155 <li>com.android.*</li> 1156</ul> 1157 1158<p><strong>Prohibited modifications include</strong>:</p> 1159 1160<ul> 1161 <li>Device implementations MUST NOT modify the publicly exposed APIs on the Android 1162platform by changing any method or class signatures, or by removing classes or 1163class fields.</li> 1164 <li>Device implementers MAY modify the underlying implementation of the APIs, but 1165such modifications MUST NOT impact the stated behavior and Java-language 1166signature of any publicly exposed APIs.</li> 1167 <li>Device implementers MUST NOT add any publicly exposed elements (such as classes 1168or interfaces, or fields or methods to existing classes or interfaces) to the 1169APIs above.</li> 1170</ul> 1171 1172<p>A “publicly exposed element” is any construct which is not decorated with the“@hide” marker as used in the upstream Android source code. In other words, 1173device implementers MUST NOT expose new APIs or alter existing APIs in the 1174namespaces noted above. Device implementers MAY make internal-only 1175modifications, but those modifications MUST NOT be advertised or otherwise 1176exposed to developers.</p> 1177 1178<p>Device implementers MAY add custom APIs, but any such APIs MUST NOT be in a 1179namespace owned by or referring to another organization. For instance, device 1180implementers MUST NOT add APIs to the com.google.* or similar namespace: only 1181Google may do so. Similarly, Google MUST NOT add APIs to other companies' 1182namespaces. Additionally, if a device implementation includes custom APIs 1183outside the standard Android namespace, those APIs MUST be packaged in an 1184Android shared library so that only apps that explicitly use them (via the 1185lt;uses-librarygt; mechanism) are affected by the increased memory usage of such 1186APIs.</p> 1187 1188<p>If a device implementer proposes to improve one of the package namespaces above 1189(such as by adding useful new functionality to an existing API, or adding a new 1190API), the implementer SHOULD visit <a href="http://source.android.com/">source.android.com</a> and begin the process for contributing changes and code, according to the 1191information on that site.</p> 1192 1193<p>Note that the restrictions above correspond to standard conventions for naming 1194APIs in the Java programming language; this section simply aims to reinforce 1195those conventions and make them binding through inclusion in this Compatibility 1196Definition.</p> 1197 1198<h2 id="3_7_runtime_compatibility">3.7. Runtime Compatibility</h2> 1199 1200 1201<p>Device implementations MUST support the full Dalvik Executable (DEX) format and 1202Dalvik bytecode specification and semantics [<a href="https://android.googlesource.com/platform/dalvik/">Resources, 23</a>]. Device implementers SHOULD use ART, the reference upstream implementation of 1203the Dalvik Executable Format, and the reference implementation’s package 1204management system.</p> 1205 1206<p>Device implementations MUST configure Dalvik runtimes to allocate memory in 1207accordance with the upstream Android platform, and as specified by the 1208following table. (See <a href="#7_1_1_screen_configuration">section 7.1.1</a> for screen size and screen density definitions.)</p> 1209 1210<p>Note that memory values specified below are considered minimum values and 1211device implementations MAY allocate more memory per application.</p> 1212 1213<table> 1214 <tr> 1215 <th>Screen Layout</th> 1216 <th>Screen Density</th> 1217 <th>Minimum Application Memory</th> 1218 </tr> 1219 <tr> 1220 <td rowspan="12">Android Watch</td> 1221 <td>120 dpi (ldpi)</td> 1222 <td rowspan="3">32MB</td> 1223 </tr> 1224 <tr> 1225 <td>160 dpi (mdpi)</td> 1226 </tr> 1227 <tr> 1228 <td>213 dpi (tvdpi)</td> 1229 </tr> 1230 <tr> 1231 <td>240 dpi (hdpi)</td> 1232 <td rowspan="2">36MB</td> 1233 </tr> 1234 <tr> 1235 <td>280 dpi (280dpi)</td> 1236 </tr> 1237 <tr> 1238 <td>320 dpi (xhdpi)</td> 1239 <td rowspan="2">48MB</td> 1240 </tr> 1241 <tr> 1242 <td>360 dpi (360dpi)</td> 1243 </tr> 1244 <tr> 1245 <td>400 dpi (400dpi)</td> 1246 <td>56MB</td> 1247 </tr> 1248 <tr> 1249 <td>420 dpi (420dpi)</td> 1250 <td>64MB</td> 1251 </tr> 1252 <tr> 1253 <td>480 dpi (xxhdpi)</td> 1254 <td>88MB</td> 1255 </tr> 1256 <tr> 1257 <td>560 dpi (560dpi)</td> 1258 <td>112MB</td> 1259 </tr> 1260 <tr> 1261 <td>640 dpi (xxxhdpi)</td> 1262 <td>154MB</td> 1263 </tr> 1264 <tr> 1265 <td rowspan="12">small/normal</td> 1266 <td>120 dpi (ldpi)</td> 1267 <td rowspan="2">32MB</td> 1268 </tr> 1269 <tr> 1270 <td>160 dpi (mdpi)</td> 1271 </tr> 1272 <tr> 1273 <td>213 dpi (tvdpi)</td> 1274 <td rowspan="3">48MB</td> 1275 </tr> 1276 <tr> 1277 <td>240 dpi (hdpi)</td> 1278 </tr> 1279 <tr> 1280 <td>280 dpi (280dpi)</td> 1281 </tr> 1282 <tr> 1283 <td>320 dpi (xhdpi)</td> 1284 <td rowspan="2">80MB</td> 1285 </tr> 1286 <tr> 1287 <td>360 dpi (360dpi)</td> 1288 </tr> 1289 <tr> 1290 <td>400 dpi (400dpi)</td> 1291 <td>96MB</td> 1292 </tr> 1293 <tr> 1294 <td>420 dpi (420dpi)</td> 1295 <td>112MB</td> 1296 </tr> 1297 <tr> 1298 <td>480 dpi (xxhdpi)</td> 1299 <td>128MB</td> 1300 </tr> 1301 <tr> 1302 <td>560 dpi (560dpi)</td> 1303 <td>192MB</td> 1304 </tr> 1305 <tr> 1306 <td>640 dpi (xxxhdpi)</td> 1307 <td>256MB</td> 1308 </tr> 1309 <tr> 1310 <td rowspan="12">large</td> 1311 <td>120 dpi (ldpi)</td> 1312 <td>32MB</td> 1313 </tr> 1314 <tr> 1315 <td>160 dpi (mdpi)</td> 1316 <td>48MB</td> 1317 </tr> 1318 <tr> 1319 <td>213 dpi (tvdpi)</td> 1320 <td rowspan="2">80MB</td> 1321 </tr> 1322 <tr> 1323 <td>240 dpi (hdpi)</td> 1324 </tr> 1325 <tr> 1326 <td>280 dpi (280dpi)</td> 1327 <td>96MB</td> 1328 </tr> 1329 <tr> 1330 <td>320 dpi (xhdpi)</td> 1331 <td>128MB</td> 1332 </tr> 1333 <tr> 1334 <td>360 dpi (360dpi)</td> 1335 <td>160MB</td> 1336 </tr> 1337 <tr> 1338 <td>400 dpi (400dpi)</td> 1339 <td>192MB</td> 1340 </tr> 1341 <tr> 1342 <td>420 dpi (420dpi)</td> 1343 <td>228MB</td> 1344 </tr> 1345 <tr> 1346 <td>480 dpi (xxhdpi)</td> 1347 <td>256MB</td> 1348 </tr> 1349 <tr> 1350 <td>560 dpi (560dpi)</td> 1351 <td>384MB</td> 1352 </tr> 1353 <tr> 1354 <td>640 dpi (xxxhdpi)</td> 1355 <td>512MB</td> 1356 </tr> 1357 <tr> 1358 <td rowspan="12">xlarge</td> 1359 <td>120 dpi (ldpi)</td> 1360 <td>48MB</td> 1361 </tr> 1362 <tr> 1363 <td>160 dpi (mdpi)</td> 1364 <td>80MB</td> 1365 </tr> 1366 <tr> 1367 <td>213 dpi (tvdpi)</td> 1368 <td rowspan="2">96MB</td> 1369 </tr> 1370 <tr> 1371 <td>240 dpi (hdpi)</td> 1372 </tr> 1373 <tr> 1374 <td>280 dpi (280dpi)</td> 1375 <td>144MB</td> 1376 </tr> 1377 <tr> 1378 <td>320 dpi (xhdpi)</td> 1379 <td>192MB</td> 1380 </tr> 1381 <tr> 1382 <td>360 dpi (360dpi)</td> 1383 <td>240MB</td> 1384 </tr> 1385 <tr> 1386 <td>400 dpi (400dpi)</td> 1387 <td>288MB</td> 1388 </tr> 1389 <tr> 1390 <td>420 dpi (420dpi)</td> 1391 <td>336MB</td> 1392 </tr> 1393 <tr> 1394 <td>480 dpi (xxhdpi)</td> 1395 <td>384MB</td> 1396 </tr> 1397 <tr> 1398 <td>560 dpi (560dpi)</td> 1399 <td>576MB</td> 1400 </tr> 1401 <tr> 1402 <td>640 dpi (xxxhdpi)</td> 1403 <td>768MB</td> 1404 </tr> 1405</table> 1406 1407 1408<h2 id="3_8_user_interface_compatibility">3.8. User Interface Compatibility</h2> 1409 1410 1411<h3 id="3_8_1_launcher_home_screen">3.8.1. Launcher (Home Screen)</h3> 1412 1413 1414<p>Android includes a launcher application (home screen) and support for 1415third-party applications to replace the device launcher (home screen). Device 1416implementations that allow third-party applications to replace the device home 1417screen MUST declare the platform feature android.software.home_screen.</p> 1418 1419<h3 id="3_8_2_widgets">3.8.2. Widgets</h3> 1420 1421<div class="note"> 1422<p>Widgets are optional for all Android device implementations, but SHOULD be 1423supported on Android Handheld devices.</p> 1424</div> 1425 1426 1427<p>Android defines a component type and corresponding API and lifecycle that 1428allows applications to expose an “AppWidget” to the end user [<a href="http://developer.android.com/guide/practices/ui_guidelines/widget_design.html">Resources, 24</a>] a feature that is STRONGLY RECOMMENDED to be supported on Handheld Device 1429implementations. Device implementations that support embedding widgets on the 1430home screen MUST meet the following requirements and declare support for 1431platform feature android.software.app_widgets.</p> 1432 1433<ul> 1434 <li>Device launchers MUST include built-in support for AppWidgets, and expose user 1435interface affordances to add, configure, view, and remove AppWidgets directly 1436within the Launcher.</li> 1437 <li>Device implementations MUST be capable of rendering widgets that are 4 x 4 in 1438the standard grid size. See the App Widget Design Guidelines in the Android SDK 1439documentation [<a href="http://developer.android.com/guide/practices/ui_guidelines/widget_design.html">Resources, 24</a>] for details.</li> 1440 <li>Device implementations that include support for lock screen MAY support 1441application widgets on the lock screen.</li> 1442</ul> 1443 1444<h3 id="3_8_3_notifications">3.8.3. Notifications</h3> 1445 1446 1447<p>Android includes APIs that allow developers to notify users of notable events [<a href="http://developer.android.com/guide/topics/ui/notifiers/notifications.html">Resources, 25</a>], using hardware and software features of the device.</p> 1448 1449<p>Some APIs allow applications to perform notifications or attract attention 1450using hardware—specifically sound, vibration, and light. Device implementations 1451MUST support notifications that use hardware features, as described in the SDK 1452documentation, and to the extent possible with the device implementation 1453hardware. For instance, if a device implementation includes a vibrator, it MUST 1454correctly implement the vibration APIs. If a device implementation lacks 1455hardware, the corresponding APIs MUST be implemented as no-ops. This behavior 1456is further detailed in <a href="#7_hardware_compatibility">section 7</a>.</p> 1457 1458<p>Additionally, the implementation MUST correctly render all resources (icons, animation files 1459etc.) provided for in the APIs 1460[<a href="https://developer.android.com/guide/topics/resources/available-resources.html">Resources, 26</a>], 1461or in the Status/System Bar icon style guide 1462[<a href="http://developer.android.com/design/style/iconography.html">Resources, 27</a>], 1463which in the case of an Android Television device includes the possibility to not display the 1464notifications. Device implementers MAY provide an alternative user experience for 1465notifications than that provided by the reference Android Open Source 1466implementation; however, such alternative notification systems MUST support 1467existing notification resources, as above. </p> 1468 1469<p>Android includes support for various notifications, such as:</p> 1470 1471<ul> 1472 <li><strong>Rich notifications</strong>. Interactive Views for ongoing notifications.</li> 1473 <li><strong>Heads-up notifications</strong>. Interactive Views users can act on or dismiss without leaving the current app.</li> 1474 <li><strong>Lockscreen notifications</strong>. Notifications shown over a lock screen with granular control on visibility.</li> 1475</ul> 1476 1477<p>Android device implementations, when such notifications are made visible, MUST properly execute 1478Rich and Heads-up notifications and include the title/name, icon, text as documented in the Android 1479APIs [<a href="https://developer.android.com/design/patterns/notifications.html">Resources, 28</a>]. 1480</p> 1481 1482<p>Android includes Notification Listener Service APIs that allow apps (once 1483explicitly enabled by the user) to receive a copy of all notifications as they 1484are posted or updated. Device implementations MUST correctly and promptly send 1485notifications in their entirety to all such installed and user-enabled listener 1486services, including any and all metadata attached to the Notification object.</p> 1487 1488<h3 id="3_8_4_search">3.8.4. Search</h3> 1489 1490 1491<p>Android includes APIs [<a href="http://developer.android.com/reference/android/app/SearchManager.html">Resources, 29</a>] that allow developers to incorporate search into their applications, and 1492expose their application’s data into the global system search. Generally 1493speaking, this functionality consists of a single, system-wide user interface 1494that allows users to enter queries, displays suggestions as users type, and 1495displays results. The Android APIs allow developers to reuse this interface to 1496provide search within their own apps, and allow developers to supply results to 1497the common global search user interface.</p> 1498 1499<p>Android device implementations SHOULD include global search, a single, shared, 1500system-wide search user interface capable of real-time suggestions in response 1501to user input. Device implementations SHOULD implement the APIs that allow 1502developers to reuse this user interface to provide search within their own 1503applications. Device implementations that implement the global search interface 1504MUST implement the APIs that allow third-party applications to add suggestions 1505to the search box when it is run in global search mode. If no third-party 1506applications are installed that make use of this functionality, the default 1507behavior SHOULD be to display web search engine results and suggestions.</p> 1508 1509<p>Android device implementations SHOULD implement an assistant on the device 1510to handle the Assist action [<a 1511href="http://developer.android.com/reference/android/content/Intent.html#ACTION_ASSIST">Resources, 151230</a>].</p> 1513 1514<p>Android also includes the Assist APIs to allow applications to elect how much 1515information of the current context is shared with the assistant on the device [<a 1516href="https://developer.android.com/reference/android/app/assist/package-summary.html">Resources, 151731</a>]. Device implementations supporting the Assist action MUST indicate clearly to 1518the end user when the the context is shared by displaying a white light around 1519the edges of the screen. To ensure clear visibility to the end user, the indication MUST 1520meet or exceed the duration and brightness of the Android Open Source Project 1521implementation.</p> 1522 1523<h3 id="3_8_5_toasts">3.8.5. Toasts</h3> 1524 1525 1526<p>Applications can use the “Toast” API to display short non-modal strings to the 1527end user, that disappear after a brief period of time [<a href="http://developer.android.com/reference/android/widget/Toast.html">Resources, 32</a>]. Device implementations MUST display Toasts from applications to end users in 1528some high-visibility manner.</p> 1529 1530<h3 id="3_8_6_themes">3.8.6. Themes</h3> 1531 1532 1533<p>Android provides “themes” as a mechanism for applications to apply styles 1534across an entire Activity or application.</p> 1535 1536<p>Android includes a “Holo” theme family as a set of defined styles for 1537application developers to use if they want to match the Holo theme look and 1538feel as defined by the Android SDK [<a href="http://developer.android.com/guide/topics/ui/themes.html">Resources, 33</a>]. Device implementations MUST NOT alter any of the Holo theme attributes 1539exposed to applications [<a href="http://developer.android.com/reference/android/R.style.html">Resources, 34</a>].</p> 1540 1541<p>Android includes a “Material” theme family as a set of defined styles for 1542application developers to use if they want to match the design theme’s look and 1543feel across the wide variety of different Android device types. Device 1544implementations MUST support the “Material” theme family and MUST NOT alter any 1545of the Material theme attributes or their assets exposed to applications [<a href="http://developer.android.com/reference/android/R.style.html#Theme_Material">Resources, 35</a>].</p> 1546 1547<p>Android also includes a “Device Default” theme family as a set of defined 1548styles for application developers to use if they want to match the look and 1549feel of the device theme as defined by the device implementer. Device 1550implementations MAY modify the Device Default theme attributes exposed to 1551applications [<a href="http://developer.android.com/reference/android/R.style.html">Resources, 34</a>].</p> 1552 1553<p>Android supports a variant theme with translucent system bars, which allows 1554application developers to fill the area behind the status and navigation bar 1555with their app content. To enable a consistent developer experience in this 1556configuration, it is important the status bar icon style is maintained across 1557different device implementations. Therefore, Android device implementations 1558MUST use white for system status icons (such as signal strength and battery 1559level) and notifications issued by the system, unless the icon is indicating a 1560problematic status or an app requests a light status bar using the 1561SYSTEM_UI_FLAG_LIGHT_STATUS_BAR flag. When an app requests a light status bar, 1562Android device implementations MUST change the color of the system status icons 1563to black [<a href="http://developer.android.com/reference/android/R.style.html">Resources, 34</a>].</p> 1564 1565<h3 id="3_8_7_live_wallpapers">3.8.7. Live Wallpapers</h3> 1566 1567 1568<p>Android defines a component type and corresponding API and lifecycle that 1569allows applications to expose one or more “Live Wallpapers” to the end user [<a href="http://developer.android.com/reference/android/service/wallpaper/WallpaperService.html">Resources, 36</a>]. Live wallpapers are animations, patterns, or similar images with limited 1570input capabilities that display as a wallpaper, behind other applications.</p> 1571 1572<p>Hardware is considered capable of reliably running live wallpapers if it can 1573run all live wallpapers, with no limitations on functionality, at a reasonable 1574frame rate with no adverse effects on other applications. If limitations in the 1575hardware cause wallpapers and/or applications to crash, malfunction, consume 1576excessive CPU or battery power, or run at unacceptably low frame rates, the 1577hardware is considered incapable of running live wallpaper. As an example, some 1578live wallpapers may use an OpenGL 2.0 or 3.x context to render their content. 1579Live wallpaper will not run reliably on hardware that does not support multiple 1580OpenGL contexts because the live wallpaper use of an OpenGL context may 1581conflict with other applications that also use an OpenGL context.</p> 1582 1583<p>Device implementations capable of running live wallpapers reliably as described 1584above SHOULD implement live wallpapers, and when implemented MUST report the 1585platform feature flag android.software.live_wallpaper.</p> 1586 1587<h3 id="3_8_8_activity_switching">3.8.8. Activity Switching</h3> 1588 1589<div class="note"> 1590<p>As the Recent function navigation key is OPTIONAL, the requirements to 1591implement the overview screen is OPTIONAL for Android Television devices and 1592Android Watch devices.</p> 1593</div> 1594 1595 1596<p>The upstream Android source code includes the overview screen [<a href="http://developer.android.com/guide/components/recents.html">Resources, 37</a>], a system-level user interface for task switching and displaying recently 1597accessed activities and tasks using a thumbnail image of the application’s 1598graphical state at the moment the user last left the application. Device 1599implementations including the recents function navigation key as detailed in <a href="#7_2_3_navigation_keys">section 7.2.3</a>, MAY alter the interface but MUST meet the following requirements:</p> 1600 1601<ul> 1602 <li>MUST display affiliated recents as a group that moves together.</li> 1603 <li>MUST support at least up to 20 displayed activities.</li> 1604 <li>MUST at least display the title of 4 activities at a time.</li> 1605 <li>SHOULD display highlight color, icon, screen title in recents.</li> 1606 <li>MUST implement the screen pinning behavior [<a href="http://developer.android.com/about/versions/android-5.0.html#ScreenPinning">Resources, 38</a>] and provide the user with a settings menu to toggle the feature.</li> 1607 <li>SHOULD display a closing affordance ("x") but MAY delay this until user 1608interacts with screens.</li> 1609</ul> 1610 1611<p>Device implementations are STRONGLY RECOMMENDED to use the upstream Android user 1612interface (or a similar thumbnail-based interface) for the overview screen.</p> 1613 1614<h3 id="3_8_9_input_management">3.8.9. Input Management</h3> 1615 1616 1617<p>Android includes support for Input Management and support for third-party input 1618method editors [<a href="http://developer.android.com/guide/topics/text/creating-input-method.html">Resources, 39</a>]. Device implementations that allow users to use third-party input methods on 1619the device MUST declare the platform feature android.software.input_methods and 1620support IME APIs as defined in the Android SDK documentation.</p> 1621 1622<p>Device implementations that declare the android.software.input_methods feature 1623MUST provide a user-accessible mechanism to add and configure third-party input 1624methods. Device implementations MUST display the settings interface in response 1625to the android.settings.INPUT_METHOD_SETTINGS intent.</p> 1626 1627<h3 id="3_8_10_lock_screen_media_control">3.8.10. Lock Screen Media Control</h3> 1628 1629 1630<p>The Remote Control Client API is deprecated from Android 5.0 in favor of the 1631Media Notification Template that allows media applications to integrate with 1632playback controls that are displayed on the lock screen [<a href="http://developer.android.com/reference/android/app/Notification.MediaStyle.html">Resources, 40</a>]. 1633Device implementations that support a lock screen, unless an Android Automotive or Watch 1634implementation, MUST display the Lockscreen Notifications including the Media Notification 1635Template.</p> 1636 1637<h3 id="3_8_11_dreams">3.8.11. Dreams</h3> 1638 1639 1640<p>Android includes support for interactive screensavers called Dreams [<a href="http://developer.android.com/reference/android/service/dreams/DreamService.html">Resources, 41</a>]. Dreams allows users to interact with applications when a device connected to 1641a power source is idle or docked in a desk dock. Android Watch devices MAY 1642implement Dreams, but other types of device implementations SHOULD include 1643support for Dreams and provide a settings option for users to configure Dreams 1644in response to the android.settings.DREAM_SETTINGS intent.</p> 1645 1646<h3 id="3_8_12_location">3.8.12. Location</h3> 1647 1648 1649<p>When a device has a hardware sensor (e.g. GPS) that is capable of providing the 1650location coordinates, location modes MUST be displayed in the Location menu 1651within Settings [<a href="http://developer.android.com/reference/android/provider/Settings.Secure.html#LOCATION_MODE">Resources, 42</a>].</p> 1652 1653<h3 id="3_8_13_unicode_and_font">3.8.13. Unicode and Font</h3> 1654 1655 1656<p>Android includes support for color emoji characters. When Android device 1657implementations include an IME, devices SHOULD provide an input method to the 1658user for the Emoji characters defined in Unicode 6.1 [<a href="http://www.unicode.org/versions/Unicode6.1.0/">Resources, 43</a>]. All devices MUST be capable of rendering these emoji characters in color glyph.</p> 1659 1660<p>Android includes support for Roboto 2 font with different 1661weights—sans-serif-thin, sans-serif-light, sans-serif-medium, sans-serif-black, 1662sans-serif-condensed, sans-serif-condensed-light—which MUST all be included for 1663the languages available on the device and full Unicode 7.0 coverage of Latin, 1664Greek, and Cyrillic, including the Latin Extended A, B, C, and D ranges, and 1665all glyphs in the currency symbols block of Unicode 7.0.</p> 1666 1667<h2 id="3_9_device_administration">3.9. Device Administration</h2> 1668 1669<p>Android includes features that allow security-aware applications to perform 1670device administration functions at the system level, such as enforcing password 1671policies or performing remote wipe, through the Android Device Administration 1672API [<a href="http://developer.android.com/guide/topics/admin/device-admin.html">Resources, 44</a>]. 1673Device implementations MUST provide an implementation of the DevicePolicyManager class 1674[<a href="http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html">Resources, 45</a>]. 1675Device implementations that include support for PIN (numeric) or PASSWORD 1676(alphanumeric) based lock screens MUST support the full range of device 1677administration policies defined in the Android SDK documentation 1678[<a href="http://developer.android.com/guide/topics/admin/device-admin.html">Resources, 44</a>] 1679and report the platform feature android.software.device_admin.</p> 1680 1681<h3 id="3_9_1_device_provisioning">3.9.1 Device Provisioning</h3> 1682<h4 id="3_9_1_1_device_owner_provisioning">3.9.1.1 Device owner provisioning</h4> 1683<p>If a device implementation declares the android.software.device_admin feature, 1684the out of box setup flow MUST make it possible to enroll a Device Policy 1685Controller (DPC) application as the Device Owner app 1686[<a href="http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html#isDeviceOwnerApp(java.lang.String)"> 1687Resources, 46</a>]. Device implementations MAY have a preinstalled application 1688performing device administration functions but this application MUST NOT be set 1689as the Device Owner app without explicit consent or action from the user or the 1690administrator of the device.</p> 1691 1692<p>The device owner provisioning process (the flow initiated by 1693android.app.action.PROVISION_MANAGED_DEVICE 1694[<a href="http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html#ACTION_PROVISION_MANAGED_DEVICE"> 1695Resources, 47</a>]) user experience MUST align with the AOSP implementation</p> 1696 1697<p>If the device implementation reports android.hardware.nfc, it MUST have NFC 1698enabled, even during the out-of-box setup flow, in order to allow for NFC 1699provisioning of Device owners 1700[<a href="https://source.android.com/devices/tech/admin/provision.html#device_owner_provisioning_via_nfc">Resources, 48</a>]. 1701</p> 1702 1703<h4 id="3_9_1_2_managed_profile_provisioning">3.9.1.2 Managed profile provisioning</h4> 1704<p>If a device implementation declares the android.software.managed_users, 1705it MUST be possible to enroll a Device Policy Controller (DPC) application 1706as the owner of a new Managed Profile 1707[<a href="http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html#isProfileOwnerApp(java.lang.String)"> 1708Resources, 49</a>]</p> 1709 1710<p>The managed profile provisioning process (the flow initiated by 1711android.app.action.PROVISION_MANAGED_PROFILE 1712[<a href="http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html#ACTION_PROVISION_MANAGED_PROFILE"> 1713Resources, 50</a>]) user experience MUST align with the AOSP implementation 1714</p> 1715 1716 1717<h2 id="3_9_2_managed_profile_support">3.9.2 Managed Profile Support</h2> 1718 1719<p>Managed profile capable devices are those devices that:</p> 1720<ul> 1721 <li>Declare android.software.device_admin (see <a href="#3_9_device_administration">section 3.9 Device Administration)</a></li> 1722 <li>Are not low RAM devices (see <a href="#7_6_1_minimum_memory_and_storage">section 7.6.1</a></li> 1723 <li>Allocate internal (non-removable) storage as shared storage (see 1724 <a href="#7_6_2_application_shared_storage">section 7.6.2</a>)</li> 1725</ul> 1726<p>Managed profile capable devices MUST:</p> 1727<ul> 1728 <li>Declare the platform feature flag android.software.managed_users.</li> 1729 <li>Support managed profiles via the android.app.admin.DevicePolicyManager APIs</li> 1730 <li>Allow one and only one managed profile to be created [<a 1731href="http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html#ACTION_PROVISION_MANAGED_PROFILE">Resources, 173250</a>]</li> 1733 <li>Use an icon badge (similar to the AOSP upstream work badge) to represent 1734the managed applications and widgets and other badged UI elements like Recents 1735& Notifications</li> 1736 <li>Display a notification icon (similar to the AOSP upstream work badge) to 1737indicate when user is within a managed profile application</li> 1738 <li>Display a toast indicating that the user is in the managed profile if and when the 1739device wakes up (ACTION_USER_PRESENT) and the foreground application is within 1740the managed profile</li> 1741 <li>Where a managed profile exists, show a visual affordance in the Intent 1742'Chooser' to allow the user to forward the intent from the managed profile to 1743the primary user or vice versa, if enabled by the Device Policy Controller</li> 1744 <li>Where a managed profile exists, expose the following user affordances for both 1745the primary user and the managed profile: 1746 <ul> 1747 <li>Separate accounting for battery, location, mobile data and storage usage 1748 for the primary user and managed profile.</li> 1749 <li>Independent management of VPN Applications installed within the primary 1750 user or managed profile.</li> 1751 <li>Independent management of applications installed within the primary user 1752 user or managed profile.</li> 1753 <li>Independent management of accounts within the primary user or managed 1754 profile.</li> 1755 </ul> 1756 </li> 1757 <li>Ensure the default dialer can look up caller information from the managed 1758profile (if one exists) alongside those from the primary profile, if the Device 1759Policy Controller permits it.</li> 1760 <li>MUST ensure that it satisfies all the security requirements applicable for a device 1761 with multiple users enabled (see <a href="#9_5_multi-user_support">section 9.5</a>), 1762 even though the managed profile is not counted as another user in addition to the 1763 primary user.</li> 1764</ul> 1765 1766<h2 id="3_10_accessibility">3.10. Accessibility</h2> 1767 1768 1769<p>Android provides an accessibility layer that helps users with disabilities to 1770navigate their devices more easily. In addition, Android provides platform APIs 1771that enable accessibility service implementations to receive callbacks for user 1772and system events and generate alternate feedback mechanisms, such as 1773text-to-speech, haptic feedback, and trackball/d-pad navigation [<a href="http://developer.android.com/reference/android/accessibilityservice/AccessibilityService.html">Resources, 51</a>].</p> 1774 1775<p>Device implementations include the following requirements:</p> 1776 1777<ul> 1778<li>Android Automotive implementations SHOULD provide an implementation of the 1779Android accessibility framework consistent with the default Android 1780implementation.</li> 1781<li>Device implementations (Android Automotive excluded) MUST provide an 1782implementation of the Android accessibility framework consistent with the 1783default Android implementation.</li> 1784<li>Device implementations (Android Automotive excluded) MUST support 1785third-party accessibility service implementations through the 1786android.accessibilityservice APIs 1787[<a href="http://developer.android.com/reference/android/view/accessibility/package-summary.html">Resources, 52</a>]</li> 1788<li>Device implementations (Android Automotive excluded) MUST generate 1789AccessibilityEvents and deliver these events to all registered 1790AccessibilityService implementations in a manner consistent with the default 1791Android implementation</li> 1792<li> Device implementations (Android Automotive and Android Watch devices with 1793no audio output excluded), MUST provide a user-accessible mechanism to enable 1794and disable accessibility services, and MUST display this interface in response 1795to the android.provider.Settings.ACTION_ACCESSIBILITY_SETTINGS intent.</li> 1796</ul> 1797 1798<p>Additionally, device implementations SHOULD provide an implementation of an 1799accessibility service on the device, and SHOULD provide a mechanism for users 1800to enable the accessibility service during device setup. An open source 1801implementation of an accessibility service is available from the Eyes Free 1802project [<a href="http://code.google.com/p/eyes-free/">Resources, 53</a>].</p> 1803 1804<h2 id="3_11_text-to-speech">3.11. Text-to-Speech</h2> 1805 1806 1807<p>Android includes APIs that allow applications to make use of text-to-speech 1808(TTS) services and allows service providers to provide implementations of TTS 1809services [<a href="http://developer.android.com/reference/android/speech/tts/package-summary.html">Resources, 54</a>]. Device implementations reporting the feature android.hardware.audio.output 1810MUST meet these requirements related to the Android TTS framework. </p> 1811 1812<p>Android Automotive implementations:</p> 1813<ul> 1814<li>MUST support the Android TTS framework APIs.</li> 1815<li>MAY support installation of third-party TTS engines. If supported, partners 1816MUST provide a user-accessible interface that allows the user to select a TTS 1817engine for use at system level.</li> 1818</ul> 1819 1820<p>All other device implementations:</p> 1821 1822<ul> 1823 <li> MUST support the Android TTS framework APIs and SHOULD include a TTS engine 1824supporting the languages available on the device. Note that the upstream 1825Android open source software includes a full-featured TTS engine 1826implementation. 1827 <li> MUST support installation of third-party TTS engines 1828 <li> MUST provide a user-accessible interface that allows users to select a TTS 1829engine for use at the system level 1830</ul> 1831 1832<h2 id="3_12_tv_input_framework">3.12. TV Input Framework</h2> 1833 1834 1835<p>The Android Television Input Framework (TIF) simplifies the delivery of live 1836content to Android Television devices. TIF provides a standard API to create 1837input modules that control Android Television devices. Android Television 1838device implementations MUST support TV Input Framework 1839[<a href="http://source.android.com/devices/tv/index.html">Resources, 55</a>].</p> 1840 1841<p>Device implementations that support TIF MUST declare the platform feature 1842android.software.live_tv.</p> 1843 1844<h3 id="3_12_1_tv_app">3.12.1. TV App</h3> 1845 1846<p>Any device implementation that declares support for Live TV MUST have an 1847installed TV application (TV App). The Android Open Source Project provides an implementation of the TV 1848App.</p> 1849 1850The default TV app must provide accesss to channels from installed inputs and third-party inputs. 1851Note that the installed inputs encompass all the inputs provided by default, whether they are TIF-based or not. 1852 1853<p>The TV App MUST provide facilities to install and use TV Channels 1854[<a href="http://developer.android.com/reference/android/media/tv/TvContract.Channels.html">Resources, 56</a>] 1855 and meet the following requirements:</p> 1856 1857<ul> 1858 <li>Device implementations MUST allow third-party TIF-based inputs (third-party inputs) 1859[<a href="https://source.android.com/devices/tv/index.html#third-party_input_example">Resources, 57</a>] 1860 to be installed and managed. 1861 <li>Device implementations MAY provide visual separation between pre-installed 1862 TIF-based inputs (installed inputs) 1863[<a href="https://source.android.com/devices/tv/index.html#tv_inputs">Resources, 58</a>] 1864 and third-party inputs. 1865 <li>The device implementations MUST NOT display the third-party inputs more than a 1866single navigation action away from the TV App (i.e. expanding a list of 1867third-party inputs from the TV App). 1868</ul> 1869 1870<h4 id="3_12_1_1_electronic_program_guide">3.12.1.1. Electronic Program Guide</h4> 1871 1872<p>Android Television device implementations MUST show an informational and 1873interactive overlay, which MUST include an electronic program guide (EPG) 1874generated from the values in the TvContract.Programs fields 1875[<a href="https://developer.android.com/reference/android/media/tv/TvContract.Programs.html">Resources, 59</a>]. 1876 The EPG MUST meet the following requirements:</p> 1877 1878<ul> 1879 <li>The EPG MUST display information from all installed inputs and third-party 1880inputs. 1881 <li>The EPG MAY provide visual separation between the installed inputs and 1882third-party inputs. 1883 <li>The EPG is STRONGLY RECOMMENDED to display installed inputs and third-party 1884inputs with equal prominence. The EPG MUST NOT display the third-party inputs 1885more than a single navigation action away from the installed inputs on the EPG. 1886 <li>On channel change, device implementations MUST display EPG data for the 1887currently playing program. 1888</ul> 1889 1890<h4 id="3_12_1_2_navigation">3.12.1.2. Navigation</h4> 1891 1892<p>Android Television device input devices (i.e. remote control, remote control 1893application, or game controller) MUST allow navigation to all actionable 1894sections of the screen via the D-pad. D-pad up and down MUST be used to change 1895live TV channels when there is no actionable section on the screen.</p> 1896 1897<p>The TV App SHOULD pass key events to HDMI inputs through CEC.</p> 1898 1899<h4 id="3_12_1_3_tv_input_app_linking">3.12.1.3. TV input app linking</h4> 1900 1901<p>Android Television device implementations MUST support TV input app linking, 1902which allows all inputs to provide activity links from the current activity to 1903another activity (i.e. a link from live programming to related content) 1904[<a href="http://developer.android.com/reference/android/media/tv/TvContract.Channels.html#COLUMN_APP_LINK_INTENT_URI">Resources, 60</a>]. 1905 The TV App MUST show TV input app linking when it is provided.</p> 1906 1907<h1 id="4_application_packaging_compatibility">4. Application Packaging Compatibility</h1> 1908 1909 1910<p>Device implementations MUST install and run Android “.apk” files as generated 1911by the “aapt” tool included in the official Android SDK [<a href="http://developer.android.com/tools/help/index.html">Resources, 61</a>].</p> 1912 1913<p>Devices implementations MUST NOT extend either the .apk [<a href="http://developer.android.com/guide/components/fundamentals.html">Resources, 62</a>], Android Manifest [<a href="http://developer.android.com/guide/topics/manifest/manifest-intro.html">Resources, 49</a>], Dalvik bytecode [<a href="https://android.googlesource.com/platform/dalvik/">Resources, 23</a>], or RenderScript bytecode formats in such a way that would prevent those 1914files from installing and running correctly on other compatible devices.</p> 1915 1916<h1 id="5_multimedia_compatibility">5. Multimedia Compatibility</h1> 1917 1918 1919<h2 id="5_1_media_codecs">5.1. Media Codecs</h2> 1920 1921 1922<p>Device implementations MUST support the core media formats specified in the 1923Android SDK documentation [<a href="http://developer.android.com/guide/appendix/media-formats.html">Resources, 64</a>] 1924except where explicitly permitted in this document. Specifically, device 1925implementations MUST support the media formats, encoders, decoders, file types, 1926and container formats defined in the tables below and reported via MediaCodecList 1927[<a href="http://developer.android.com/reference/android/media/MediaCodecList.html">Resources, 65</a>]. 1928Device implementations MUST also be able to decode all profiles reported in its CamcorderProfile 1929[<a href="http://developer.android.com/reference/android/media/CamcorderProfile.html">Resources, 193066</a>] and MUST be able to decode all formats it can encode. 1931 1932All of these codecs are 1933provided as software implementations in the preferred Android implementation 1934from the Android Open Source Project.</p> 1935 1936<p>Please note that neither Google nor the Open Handset Alliance make any 1937representation that these codecs are free from third-party patents. Those 1938intending to use this source code in hardware or software products are advised 1939that implementations of this code, including in open source software or 1940shareware, may require patent licenses from the relevant patent holders.</p> 1941 1942<h3 id="5_1_1_audio_codecs">5.1.1. Audio Codecs</h3> 1943 1944<table> 1945 <tr> 1946 <th>Format/Codec</th> 1947 <th>Encoder</th> 1948 <th>Decoder</th> 1949 <th>Details</th> 1950 <th>Supported File Types/Container Formats</th> 1951 </tr> 1952 <tr> 1953 <td>MPEG-4 AAC Profile<br /> 1954 1955(AAC LC)</td> 1956 <td>REQUIRED<sup>1</sup></td> 1957 <td>REQUIRED</td> 1958 <td>Support for mono/stereo/5.0/5.1<sup>2</sup> content with standard sampling rates from 8 to 195948 kHz.</td> 1960 <td> 1961 <ul> 1962 <li class="table_list">3GPP (.3gp)</li> 1963 <li class="table_list">MPEG-4 (.mp4, .m4a)</li> 1964 <li class="table_list">ADTS raw AAC (.aac, decode in Android 3.1+, encode in Android 4.0+, ADIF not 1965supported)</li> 1966 <li class="table_list">MPEG-TS (.ts, not seekable, Android 3.0+)</li></ul></td> 1967 </tr> 1968 <tr> 1969 <td>MPEG-4 HE AAC Profile (AAC+)</td> 1970 <td>REQUIRED<sup>1</sup><br>(Android 4.1+)</td> 1971 <td>REQUIRED</td> 1972 <td>Support for mono/stereo/5.0/5.1<sup>2</sup> content with standard sampling rates from 16 1973to 48 kHz.</td> 1974 <td></td> 1975 </tr> 1976 <tr> 1977 <td>MPEG-4 HE AACv2<br /> 1978 1979Profile (enhanced AAC+)</td> 1980 <td> </td> 1981 <td>REQUIRED</td> 1982 <td>Support for mono/stereo/5.0/5.1<sup>2</sup> content with standard sampling rates from 16 1983to 48 kHz.</td> 1984 <td></td> 1985 </tr> 1986 <tr> 1987 <td>AAC ELD (enhanced low delay AAC)</td> 1988 <td>REQUIRED<sup>1</sup> <br /> 1989 1990(Android 4.1+)</td> 1991 <td>REQUIRED<br /> 1992 1993(Android 4.1+)</td> 1994 <td>Support for mono/stereo content with standard sampling rates from 16 to 48 kHz.</td> 1995 <td></td> 1996 </tr> 1997 <tr> 1998 <td>AMR-NB</td> 1999 <td>REQUIRED<sup>3</sup></td> 2000 <td>REQUIRED<sup>3</sup></td> 2001 <td>4.75 to 12.2 kbps sampled @ 8 kHz</td> 2002 <td>3GPP (.3gp)</td> 2003 </tr> 2004 <tr> 2005 <td>AMR-WB</td> 2006 <td>REQUIRED<sup>3</sup></td> 2007 <td>REQUIRED<sup>3</sup></td> 2008 <td>9 rates from 6.60 kbit/s to 23.85 kbit/s sampled @ 16 kHz</td> 2009 <td></td> 2010 </tr> 2011 <tr> 2012 <td>FLAC</td> 2013 <td></td> 2014 <td>REQUIRED <br>(Android 3.1+)</td> 2015 <td>Mono/Stereo (no multichannel). Sample rates up to 48 kHz (but up to 44.1 kHz is 2016RECOMMENDED on devices with 44.1 kHz output, as the 48 to 44.1 kHz downsampler 2017does not include a low-pass filter). 16-bit RECOMMENDED; no dither applied for 201824-bit.</td> 2019 <td>FLAC (.flac) only</td> 2020 </tr> 2021 <tr> 2022 <td>MP3</td> 2023 <td></td> 2024 <td>REQUIRED</td> 2025 <td>Mono/Stereo 8-320Kbps constant (CBR) or variable bitrate (VBR)</td> 2026 <td>MP3 (.mp3)</td> 2027 </tr> 2028 <tr> 2029 <td>MIDI</td> 2030 <td></td> 2031 <td>REQUIRED</td> 2032 <td>MIDI Type 0 and 1. DLS Version 1 and 2. XMF and Mobile XMF. Support for 2033ringtone formats RTTTL/RTX, OTA, and iMelody</td> 2034 <td><ul> 2035 <li class="table_list">Type 0 and 1 (.mid, .xmf, .mxmf)</li> 2036 <li class="table_list">RTTTL/RTX (.rtttl, .rtx)</li> 2037 <li class="table_list">OTA (.ota)</li> 2038 <li class="table_list">iMelody (.imy)</li></ul></td> 2039 </tr> 2040 <tr> 2041 <td>Vorbis</td> 2042 <td></td> 2043 <td>REQUIRED</td> 2044 <td></td> 2045 <td><ul> 2046 <li class="table_list">Ogg (.ogg)</li> 2047 <li class="table_list">Matroska (.mkv, Android 4.0+)</li></ul></td> 2048 </tr> 2049 <tr> 2050 <td>PCM/WAVE</td> 2051 <td>REQUIRED<sup>4</sup><br> (Android 4.1+)</td> 2052 <td>REQUIRED</td> 2053 <td>16-bit linear PCM (rates up to limit of hardware). Devices MUST support 2054sampling rates for raw PCM recording at 8000, 11025, 16000, and 44100 Hz 2055frequencies.</td> 2056 <td>WAVE (.wav)</td> 2057 </tr> 2058 <tr> 2059 <td>Opus</td> 2060 <td></td> 2061 <td>REQUIRED<br> (Android 5.0+)</td> 2062 <td></td> 2063 <td>Matroska (.mkv)</td> 2064 </tr> 2065</table> 2066 2067 2068<p class="table_footnote"> 1 Required for device implementations that define android.hardware.microphone 2069but optional for Android Watch device implementations.</p> 2070 2071<p class="table_footnote">2 Only downmix of 5.0/5.1 content is required; recording or rendering more than 20722 channels is optional.</p> 2073 2074<p class="table_footnote">3 Required for Android Handheld device implementations. </p> 2075 2076<p class="table_footnote">4 Required for device implementations that define android.hardware.microphone, 2077including Android Watch device implementations.</p> 2078 2079<h3 id="5_1_2_image_codecs">5.1.2. Image Codecs</h3> 2080 2081<table> 2082 <tr> 2083 <th>Format/Codec</th> 2084 <th>Encoder</th> 2085 <th>Decoder</th> 2086 <th>Details</th> 2087 <th>Supported File Types/Container Formats</th> 2088 </tr> 2089 <tr> 2090 <td>JPEG</td> 2091 <td>REQUIRED</td> 2092 <td>REQUIRED</td> 2093 <td>Base+progressive</td> 2094 <td>JPEG (.jpg)</td> 2095 </tr> 2096 <tr> 2097 <td>GIF</td> 2098 <td></td> 2099 <td>REQUIRED</td> 2100 <td></td> 2101 <td>GIF (.gif)</td> 2102 </tr> 2103 <tr> 2104 <td>PNG</td> 2105 <td>REQUIRED</td> 2106 <td>REQUIRED</td> 2107 <td></td> 2108 <td>PNG (.png)</td> 2109 </tr> 2110 <tr> 2111 <td>BMP</td> 2112 <td></td> 2113 <td>REQUIRED</td> 2114 <td></td> 2115 <td>BMP (.bmp)</td> 2116 </tr> 2117 <tr> 2118 <td>WebP</td> 2119 <td>REQUIRED</td> 2120 <td>REQUIRED</td> 2121 <td></td> 2122 <td>WebP (.webp)</td> 2123 </tr> 2124</table> 2125 2126 2127<h3 id="5_1_3_video_codecs">5.1.3. Video Codecs</h3> 2128 2129<table> 2130 <tr> 2131 <th>Format/Codec</th> 2132 <th>Encoder</th> 2133 <th>Decoder</th> 2134 <th>Details</th> 2135 <th>Supported File Types/<br>Container Formats</th> 2136 </tr> 2137 <tr> 2138 <td>H.263</td> 2139 <td>REQUIRED<sup>1</sup></td> 2140 <td>REQUIRED<sup>2</sup></td> 2141 <td></td> 2142 <td><ul> 2143 <li class="table_list">3GPP (.3gp)</li> 2144 <li class="table_list">MPEG-4 (.mp4)</li></ul></td> 2145 </tr> 2146 <tr> 2147 <td>H.264 AVC</td> 2148 <td>REQUIRED<sup>2</sup></td> 2149 <td>REQUIRED<sup>2</sup></td> 2150 <td>See <a href="#5_2_video_encoding">section 5.2 </a>and <a href="#5_3_video_decoding">5.3</a> for details</td> 2151 <td><ul> 2152 <li class="table_list">3GPP (.3gp)</li> 2153 <li class="table_list">MPEG-4 (.mp4)</li> 2154 <li class="table_list">MPEG-2 TS (.ts, AAC audio only, not seekable, Android 3.0+)</li></ul></td> 2155 </tr> 2156 <tr> 2157 <td>H.265 HEVC</td> 2158 <td></td> 2159 <td>REQUIRED<sup>5</sup></td> 2160 <td>See <a href="#5_3_video_decoding">section 5.3</a> for details</td> 2161 <td>MPEG-4 (.mp4)</td> 2162 </tr> 2163<tr> 2164 <td>MPEG-2</td> 2165 <td></td> 2166 <td>STRONGLY RECOMMENDED<sup>6</sup></td> 2167 <td>Main Profile</td> 2168 <td>MPEG2-TS</td> 2169</tr> 2170 <tr> 2171 <td>MPEG-4 SP</td> 2172 <td></td> 2173 <td>REQUIRED<sup>2</sup></td> 2174 <td></td> 2175 <td>3GPP (.3gp)</td> 2176 </tr> 2177 <tr> 2178 <td>VP8<sup>3</sup></td> 2179 <td>REQUIRED<sup>2</sup><br /> 2180 2181(Android 4.3+)</td> 2182 <td>REQUIRED<sup>2</sup><br /> 2183 2184(Android 2.3.3+)</td> 2185 <td>See <a href="#5_2_video_encoding">section 5.2</a> and <a href="#5_3_video_decoding">5.3</a> for details</td> 2186 <td><ul> 2187 <li class="table_list">WebM (.webm) [<a href="http://www.webmproject.org/">Resources, 67</a></li> 2188 <li class="table_list">Matroska (.mkv, Android 4.0+)<sup>4</sup></li></ul></td> 2189 </tr> 2190 <tr> 2191 <td>VP9</td> 2192 <td></td> 2193 <td>REQUIRED<sup>2</sup><br> (Android 4.4+)</td> 2194 <td>See <a href="#5_3_video_decoding">section 5.3</a> for details</td> 2195 <td><ul> 2196 <li class="table_list">WebM (.webm) [<a href="http://www.webmproject.org/">Resources, 67</a>]</li> 2197 <li class="table_list">Matroska (.mkv, Android 4.0+)<sup>4</sup></li></ul></td> 2198 </tr> 2199</table> 2200 2201 2202<p class="table_footnote">1 Required for device implementations that include camera hardware and define 2203android.hardware.camera or android.hardware.camera.front.</p> 2204 2205<p class="table_footnote">2 Required for device implementations except Android Watch devices. </p> 2206 2207<p class="table_footnote">3 For acceptable quality of web video streaming and video-conference services, 2208device implementations SHOULD use a hardware VP8 codec that meets the 2209requirements in [<a href="http://www.webmproject.org/hardware/rtc-coding-requirements/">Resources, 68</a>].</p> 2210 2211<p class="table_footnote">4 Device implementations SHOULD support writing Matroska WebM files.</p> 2212 2213<p class="table_footnote">5 STRONGLY RECOMMENDED for Android Automotive, optional for Android Watch, and required for all other device types.</p> 2214 2215<p class="table_footnote">6 Applies only to Android Television device implementations.</p> 2216 2217<h2 id="5_2_video_encoding">5.2. Video Encoding</h2> 2218 2219<div class="note"> 2220<p>Video codecs are optional for Android Watch device implementations.</p> 2221</div> 2222 2223<p>Android device implementations with H.263 encoders, MUST support Baseline Profile Level 45.</p> 2224 2225<p>Android device implementations with H.264 codec support, MUST support Baseline 2226Profile Level 3 and the following SD (Standard Definition) video encoding 2227profiles and SHOULD support Main Profile Level 4 and the following HD (High 2228Definition) video encoding profiles. Android Television devices are STRONGLY RECOMMENDED 2229to encode HD 1080p video at 30 fps.</p> 2230<table> 2231 <tr> 2232 <th></th> 2233 <th>SD (Low quality)</th> 2234 <th>SD (High quality)</th> 2235 <th>HD 720p<sup>1</sup></th> 2236 <th>HD 1080p<sup>1</sup></th> 2237 </tr> 2238 <tr> 2239 <th>Video resolution</th> 2240 <td>320 x 240 px</td> 2241 <td>720 x 480 px</td> 2242 <td>1280 x 720 px</td> 2243 <td>1920 x 1080 px</td> 2244 </tr> 2245 <tr> 2246 <th>Video frame rate</th> 2247 <td>20 fps</td> 2248 <td>30 fps</td> 2249 <td>30 fps</td> 2250 <td>30 fps</td> 2251 </tr> 2252 <tr> 2253 <th>Video bitrate</th> 2254 <td>384 Kbps</td> 2255 <td>2 Mbps</td> 2256 <td>4 Mbps</td> 2257 <td>10 Mbps</td> 2258 </tr> 2259</table> 2260 2261 2262<p class="table_footnote">1 When supported by hardware, but STRONGLY RECOMMENDED for Android Television 2263devices.</p> 2264 2265<p>Android device implementations with VP8 codec support MUST support the SD video 2266encoding profiles and SHOULD support the following HD (High Definition) video 2267encoding profiles.</p> 2268<table> 2269 <tr> 2270 <th></th> 2271 <th>SD (Low quality)</th> 2272 <th>SD (High quality)</th> 2273 <th>HD 720p<sup>1</sup></th> 2274 <th>HD 1080p<sup>1</sup></th> 2275 </tr> 2276 <tr> 2277 <th>Video resolution</th> 2278 <td>320 x 180 px</td> 2279 <td>640 x 360 px</td> 2280 <td>1280 x 720 px</td> 2281 <td>1920 x 1080 px</td> 2282 </tr> 2283 <tr> 2284 <th>Video frame rate</th> 2285 <td>30 fps</td> 2286 <td>30 fps</td> 2287 <td>30 fps</td> 2288 <td>30 fps</td> 2289 </tr> 2290 <tr> 2291 <th>Video bitrate</th> 2292 <td>800 Kbps </td> 2293 <td>2 Mbps</td> 2294 <td>4 Mbps</td> 2295 <td>10 Mbps</td> 2296 </tr> 2297</table> 2298 2299<p class="table_footnote">1 When supported by hardware.</p> 2300 2301<h2 id="5_3_video_decoding">5.3. Video Decoding</h2> 2302 2303<div class="note"> 2304<p>Video codecs are optional for Android Watch device implementations.</p> 2305</div> 2306 2307<p>Device implementations MUST support dynamic video resolution and frame rate 2308switching through the standard Android APIs within the same stream for all VP8, 2309VP9, H.264, and H.265 codecs in real time and up to the maximum resolution 2310supported by each codec on the device.</p> 2311 2312<p>Android device implementations with H.263 decoders, MUST support Baseline 2313Profile Level 30.</p> 2314 2315<p>Android device implementations with MPEG-4 decoders, MUST support Simple 2316Profile Level 3.</p> 2317 2318<p>Android device implementations with H.264 decoders, MUST support Main Profile 2319Level 3.1 and the following SD video decoding profiles and SHOULD support the 2320HD decoding profiles. Android Television devices MUST support High Profile 2321Level 4.2 and the HD 1080p decoding profile.</p> 2322<table> 2323 <tr> 2324 <th></th> 2325 <th>SD (Low quality)</th> 2326 <th>SD (High quality)</th> 2327 <th>HD 720p<sup>1</sup></th> 2328 <th>HD 1080p<sup>1</sup></th> 2329 </tr> 2330 <tr> 2331 <th>Video resolution</th> 2332 <td>320 x 240 px</td> 2333 <td>720 x 480 px</td> 2334 <td>1280 x 720 px</td> 2335 <td>1920 x 1080 px</td> 2336 </tr> 2337 <tr> 2338 <th>Video frame rate</th> 2339 <td>30 fps</td> 2340 <td>30 fps</td> 2341 <td>60 fps</td> 2342 <td>30 fps / 60 fps<sup>2</sup></td> 2343 </tr> 2344 <tr> 2345 <th>Video bitrate</th> 2346 <td>800 Kbps </td> 2347 <td>2 Mbps</td> 2348 <td>8 Mbps</td> 2349 <td>20 Mbps</td> 2350 </tr> 2351</table> 2352 2353 2354<p class="table_footnote">1 REQUIRED for when the height as reported by the 2355Display.getSupportedModes() method is equal or greater than the video resolution.</p> 2356 2357<p class="table_footnote">2 REQUIRED for Android Television device implementations.</p> 2358 2359<p>Android device implementations when supporting VP8 codec as described in <a href="#5_1_3_video_codecs">section 5.1.3</a>, MUST support the following SD decoding profiles and SHOULD support the HD 2360decoding profiles. Android Television devices MUST support the HD 1080p 2361decoding profile. </p> 2362<table> 2363 <tr> 2364 <th></th> 2365 <th>SD (Low quality)</th> 2366 <th>SD (High quality)</th> 2367 <th>HD 720p<sup>1</sup></th> 2368 <th>HD 1080p<sup>1</sup></th> 2369 </tr> 2370 <tr> 2371 <th>Video resolution</th> 2372 <td>320 x 180 px</td> 2373 <td>640 x 360 px</td> 2374 <td>1280 x 720 px</td> 2375 <td>1920 x 1080 px</td> 2376 </tr> 2377 <tr> 2378 <th>Video frame rate</th> 2379 <td>30 fps</td> 2380 <td>30 fps</td> 2381 <td>30 fps / 60 fps<sup>2</sup></td> 2382 <td>30 / 60 fps<sup>2</sup></td> 2383 </tr> 2384 <tr> 2385 <th>Video bitrate</th> 2386 <td>800 Kbps </td> 2387 <td>2 Mbps</td> 2388 <td>8 Mbps</td> 2389 <td>20 Mbps</td> 2390 </tr> 2391</table> 2392 2393<p class="table_footnote">1 REQUIRED for when the height as reported by the 2394Display.getSupportedModes() method is equal or greater than the video resolution.</p> 2395 2396<p class="table_footnote">2 REQUIRED for Android Television device implementations.</p> 2397 2398<p>Android device implementations, when supporting VP9 codec as described in <a href="#5_1_3_video_codecs">section 5.1.3</a>, MUST support the following SD video decoding profiles and SHOULD support the 2399HD decoding profiles. Android Television devices are STRONGLY RECOMMENDED to 2400support the HD 1080p decoding profile and SHOULD support the UHD decoding 2401profile. When the UHD video decoding profile is supported, it MUST support 8-bit 2402color depth and SHOULD support VP9 Profile 2 (10-bit).</p> 2403<table> 2404 <tr> 2405 <th></th> 2406 <th>SD (Low quality)</th> 2407 <th>SD (High quality)</th> 2408 <th>HD 720p<sup>1</sup></th> 2409 <th>HD 1080p<sup>2</sup></th> 2410 <th>UHD<sup>2</sup></th> 2411 </tr> 2412 <tr> 2413 <th>Video resolution</th> 2414 <td>320 x 180 px</td> 2415 <td>640 x 360 px</td> 2416 <td>1280 x 720 px</td> 2417 <td>1920 x 1080 px</td> 2418 <td>3840 x 2160 px</td> 2419 </tr> 2420 <tr> 2421 <th>Video frame rate</th> 2422 <td>30 fps</td> 2423 <td>30 fps</td> 2424 <td>30 fps</td> 2425 <td>60 fps</td> 2426 <td>60 fps</td> 2427 </tr> 2428 <tr> 2429 <th>Video bitrate</th> 2430 <td>600 Kbps</td> 2431 <td>1.6 Mbps</td> 2432 <td>4 Mbps</td> 2433 <td>5 Mbps</td> 2434 <td>20 Mbps</td> 2435 </tr> 2436</table> 2437 2438 2439<p class="table_footnote">1 Required for Android Television device implementations, but for other type of 2440devices only when supported by hardware.</p> 2441 2442<p class="table_footnote">2 STRONGLY RECOMMENDED for existing Android Television device implementations when 2443supported by hardware.</p> 2444 2445<p>Android device implementations, when supporting H.265 codec as described in 2446<a href="#5_1_3_video_codecs">section 5.1.3</a>, MUST support the Main Profile 2447Level 3 Main tier and the following SD video decoding profiles and SHOULD 2448support the HD decoding profiles. 2449Android Television devices MUST support the Main Profile Level 4.1 Main tier and 2450the HD 1080p decoding profile and is STRONGLY RECOMMENDED to support the UHD 2451decoding profile. If UHD decoding is supported, then it MUST support Main10 2452Level 5 Main Tier profile.</p> 2453<table> 2454 <tr> 2455 <th></th> 2456 <th>SD (Low quality)</th> 2457 <th>SD (High quality)</th> 2458 <th>HD 720p<sup>1</sup></th> 2459 <th>HD 1080p<sup>1</sup></th> 2460 <th>UHD<sup>2</sup></th> 2461 </tr> 2462 <tr> 2463 <th>Video resolution</th> 2464 <td>352 x 288 px</td> 2465 <td>640 x 360 px</td> 2466 <td>1280 x 720 px</td> 2467 <td>1920 x 1080 px</td> 2468 <td>3840 x 2160 px</td> 2469 </tr> 2470 <tr> 2471 <th>Video frame rate</th> 2472 <td>30 fps</td> 2473 <td>30 fps</td> 2474 <td>30 fps</td> 2475 <td>60 fps<sup>2</sup></td> 2476 <td>60 fps</td> 2477 </tr> 2478 <tr> 2479 <th>Video bitrate</th> 2480 <td>600 Kbps </td> 2481 <td>1.6 Mbps</td> 2482 <td>4 Mbps</td> 2483 <td>10 Mbps</td> 2484 <td>20 Mbps</td> 2485 </tr> 2486</table> 2487 2488 2489<p class="table_footnote">1 Required for Android Television device implementations, but for other type of 2490devices only when supported by hardware.</p> 2491 2492<p class="table_footnote">2 STRONGLY RECOMMENDED 2493for existing Android Television device implementations when supported by hardware.</p> 2494 2495<h2 id="5_4_audio_recording">5.4. Audio Recording</h2> 2496 2497 2498<p>While some of the requirements outlined in this section are stated as SHOULD 2499since Android 4.3, the Compatibility Definition for a future version is planned 2500to change these to MUST. Existing and new Android devices are <strong>STRONGLY RECOMMENDED</strong> 2501to meet these requirements that are stated as SHOULD, or they will not be able to attain 2502Android compatibility when upgraded to the future version.</p> 2503 2504<h3 id="5_4_1_raw_audio_capture">5.4.1. Raw Audio Capture</h3> 2505 2506 2507<p>Device implementations that declare android.hardware.microphone MUST allow 2508capture of raw audio content with the following characteristics:</p> 2509 2510<ul> 2511 <li><strong>Format</strong>: Linear PCM, 16-bit 2512 <li><strong>Sampling rates</strong>: 8000, 11025, 16000, 44100 2513 <li><strong>Channels</strong>: Mono 2514</ul> 2515 2516<p>The capture for the above sample rates MUST be done without up-sampling, and 2517any down-sampling MUST include an appropriate anti-aliasing filter.</p> 2518 2519<p>Device implementations that declare android.hardware.microphone SHOULD allow 2520capture of raw audio content with the following characteristics:</p> 2521 2522<ul> 2523 <li><strong>Format</strong>: Linear PCM, 16-bit 2524 <li><strong>Sampling rates</strong>: 22050, 48000 2525 <li><strong>Channels</strong>: Stereo 2526</ul> 2527 2528<p>If capture for the above sample rates is supported, 2529then the capture MUST be done without up-sampling at any ratio higher than 16000:22050 2530or 44100:48000. 2531Any up-sampling or down-sampling MUST include an appropriate anti-aliasing filter.</p> 2532 2533<h3 id="5_4_2_capture_for_voice_recognition">5.4.2. Capture for Voice Recognition</h3> 2534 2535 2536<p>In addition to the above recording specifications, when an application has 2537started recording an audio stream using the 2538android.media.MediaRecorder.AudioSource.VOICE_RECOGNITION audio source:</p> 2539 2540<ul> 2541 <li>The device SHOULD exhibit approximately flat amplitude versus frequency 2542characteristics: specifically, ±3 dB, from 100 Hz to 4000 Hz. 2543 <li>Audio input sensitivity SHOULD be set such that a 90 dB sound power level (SPL) 2544source at 1000 Hz yields RMS of 2500 for 16-bit samples. 2545 <li>PCM amplitude levels SHOULD linearly track input SPL changes over at least a 30 2546dB range from -18 dB to +12 dB re 90 dB SPL at the microphone. 2547 <li>Total harmonic distortion SHOULD be less than 1% for 1 kHz at 90 dB SPL input 2548level at the microphone. 2549 <li>Noise reduction processing, if present, MUST be disabled. 2550 <li>Automatic gain control, if present, MUST be disabled 2551</ul> 2552 2553<p>If the platform supports noise suppression technologies tuned for speech 2554recognition, the effect MUST be controllable from the 2555android.media.audiofx.NoiseSuppressor API. Moreover, the UUID field for the 2556noise suppressor’s effect descriptor MUST uniquely identify each implementation 2557of the noise suppression technology.</p> 2558 2559<h3 id="5_4_3_capture_for_rerouting_of_playback">5.4.3. Capture for Rerouting of Playback</h3> 2560 2561 2562<p>The android.media.MediaRecorder.AudioSource class includes the REMOTE_SUBMIX 2563audio source. Devices that declare android.hardware.audio.output MUST properly 2564implement the REMOTE_SUBMIX audio source so that when an application uses the 2565android.media.AudioRecord API to record from this audio source, it can capture 2566a mix of all audio streams except for the following:</p> 2567 2568<ul> 2569 <li>STREAM_RING 2570 <li>STREAM_ALARM 2571 <li>STREAM_NOTIFICATION 2572</ul> 2573 2574<h2 id="5_5_audio_playback">5.5. Audio Playback</h2> 2575 2576 2577<p>Device implementations that declare android.hardware.audio.output MUST conform 2578to the requirements in this section.</p> 2579 2580<h3 id="5_5_1_raw_audio_playback">5.5.1. Raw Audio Playback</h3> 2581 2582 2583<p>The device MUST allow playback of raw audio content with the following 2584characteristics:</p> 2585 2586<ul> 2587 <li><strong>Format</strong>: Linear PCM, 16-bit</li> 2588 <li><strong>Sampling rates</strong>: 8000, 11025, 16000, 22050, 32000, 44100</li> 2589 <li><strong>Channels</strong>: Mono, Stereo</li> 2590</ul> 2591 2592<p>The device SHOULD allow playback of raw audio content with the following 2593characteristics:</p> 2594 2595<ul> 2596 <li><strong>Sampling rates</strong>: 24000, 48000</li> 2597</ul> 2598 2599<h3 id="5_5_2_audio_effects">5.5.2. Audio Effects</h3> 2600 2601 2602<p>Android provides an API for audio effects for device implementations [<a href="http://developer.android.com/reference/android/media/audiofx/AudioEffect.html">Resources, 69</a>]. Device implementations that declare the feature 2603android.hardware.audio.output:</p> 2604 2605<ul> 2606 <li>MUST support the EFFECT_TYPE_EQUALIZER and EFFECT_TYPE_LOUDNESS_ENHANCER 2607implementations controllable through the AudioEffect subclasses Equalizer, 2608LoudnessEnhancer.</li> 2609 <li>MUST support the visualizer API implementation, controllable through the 2610Visualizer class.</li> 2611 <li>SHOULD support the EFFECT_TYPE_BASS_BOOST, EFFECT_TYPE_ENV_REVERB, 2612EFFECT_TYPE_PRESET_REVERB, and EFFECT_TYPE_VIRTUALIZER implementations 2613controllable through the AudioEffect sub-classes BassBoost, 2614EnvironmentalReverb, PresetReverb, and Virtualizer.</li> 2615</ul> 2616 2617<h3 id="5_5_3_audio_output_volume">5.5.3. Audio Output Volume</h3> 2618 2619 2620<p>Android Television device implementations MUST include support for system 2621Master Volume and digital audio output volume attenuation on supported outputs, 2622except for compressed audio passthrough output (where no audio decoding is done 2623on the device).</p> 2624 2625<h2 id="5_6_audio_latency">5.6. Audio Latency</h2> 2626 2627 2628<p>Audio latency is the time delay as an audio signal passes through a system. 2629Many classes of applications rely on short latencies, to achieve real-time 2630sound effects.</p> 2631 2632<p>For the purposes of this section, use the following definitions:</p> 2633 2634<ul> 2635 <li><strong>output latency</strong>. The interval between when an application writes a frame of PCM-coded data and 2636when the corresponding sound can be heard by an external listener or observed 2637by a transducer.</li> 2638 <li><strong>cold output latency</strong>. The output latency for the first frame, when the audio output system has been 2639idle and powered down prior to the request.</li> 2640 <li><strong>continuous output latency</strong>. The output latency for subsequent frames, after the device is playing audio.</li> 2641 <li><strong>input latency</strong>. The interval between when an external sound is presented to the device and 2642when an application reads the corresponding frame of PCM-coded data.</li> 2643 <li><strong>cold input latency</strong>. The sum of lost input time and the input latency for the first frame, when the 2644audio input system has been idle and powered down prior to the request.</li> 2645 <li><strong>continuous input latency</strong>. The input latency for subsequent frames, while the device is capturing audio.</li> 2646 <li><strong>cold output jitter</strong>. The variance among separate measurements of cold output latency values.</li> 2647 <li><strong>cold input jitter</strong>. The variance among separate measurements of cold input latency values.</li> 2648 <li><strong>continuous round-trip latency</strong>. The sum of continuous input latency plus continuous output latency plus 2649 one buffer period. 2650 The buffer period term allows processing time for the app and for the app to 2651 mitigate phase difference between input and output streams. 2652 </li> 2653 <li><strong>OpenSL ES PCM buffer queue API</strong>. The set of PCM-related OpenSL ES APIs within Android NDK; see 2654NDK_root/docs/opensles/index.html.</li> 2655</ul> 2656 2657<p>Device implementations that declare android.hardware.audio.output are STRONGLY RECOMMENDED to meet 2658or exceed these audio output requirements:</p> 2659 2660<ul> 2661 <li>cold output latency of 100 milliseconds or less</li> 2662 <li>continuous output latency of 45 milliseconds or less</li> 2663 <li>minimize the cold output jitter</li> 2664</ul> 2665 2666<p>If a device implementation meets the requirements of this section after any 2667initial calibration when using the OpenSL ES PCM buffer queue API, for 2668continuous output latency and cold output latency over at least one supported 2669audio output device, it is STRONGLY RECOMMENDED to report support for low-latency audio, by reporting 2670the feature android.hardware.audio.low_latency via the 2671android.content.pm.PackageManager class [<a href="http://developer.android.com/reference/android/content/pm/PackageManager.html">Resources, 70</a>]. Conversely, if the device implementation does not meet these requirements it 2672MUST NOT report support for low-latency audio.</p> 2673 2674<p>Device implementations that include android.hardware.microphone are STRONGLY RECOMMENDED to meet 2675these input audio requirements:</p> 2676 2677<ul> 2678 <li>cold input latency of 100 milliseconds or less</li> 2679 <li>continuous input latency of 30 milliseconds or less</li> 2680 <li>continuous round-trip latency of 50 milliseconds or less</li> 2681 <li>minimize the cold input jitter</li> 2682</ul> 2683 2684<h2 id="5_7_network_protocols">5.7. Network Protocols</h2> 2685 2686 2687<p>Devices MUST support the media network protocols for audio and video playback 2688as specified in the Android SDK documentation [<a href="http://developer.android.com/guide/appendix/media-formats.html">Resources, 64</a>]. Specifically, devices MUST support the following media network protocols:</p> 2689 2690<ul> 2691 <li>RTSP (RTP, SDP)</li> 2692 <li>HTTP(S) progressive streaming</li> 2693 <li>HTTP(S) Live Streaming draft protocol, Version 3 [<a href="http://tools.ietf.org/html/draft-pantos-http-live-streaming-03">Resources, 71</a>]</li> 2694</ul> 2695 2696<h2 id="5_8_secure_media">5.8. Secure Media</h2> 2697 2698 2699<p>Device implementations that support secure video output and are capable of 2700supporting secure surfaces MUST declare support for Display.FLAG_SECURE. Device 2701implementations that declare support for Display.FLAG_SECURE, if they support a 2702wireless display protocol, MUST secure the link with a cryptographically strong 2703mechanism such as HDCP 2.x or higher for Miracast wireless displays. Similarly 2704if they support a wired external display, the device implementations MUST 2705support HDCP 1.2 or higher. Android Television device implementations MUST 2706support HDCP 2.2 for devices supporting 4K resolution and HDCP 1.4 or above for 2707lower resolutions. The upstream Android open source implementation includes 2708support for wireless (Miracast) and wired (HDMI) displays that satisfies this 2709requirement.</p> 2710 2711<h2 id="5_9_midi">5.9. Musical Instrument Digital Interface (MIDI)</h2> 2712 2713<p> 2714If a device implementation supports the inter-app MIDI software transport 2715(virtual MIDI devices), and it supports MIDI over 2716<em>all</em> of the following MIDI-capable hardware transports 2717for which it provides generic non-MIDI connectivity, it is STRONGLY RECOMMENDED to report 2718support for feature android.software.midi via the 2719android.content.pm.PackageManager class 2720[<a href="http://developer.android.com/reference/android/content/pm/PackageManager.html">Resources, 70</a>]. 2721</p> 2722 2723<p>The MIDI-capable hardware transports are:</p> 2724<ul> 2725 <li>USB host mode (section 7.7 USB)</li> 2726 <li>USB peripheral mode (section 7.7 USB)</li> 2727</ul> 2728 2729<p> 2730Conversely, if the device implementation provides generic non-MIDI connectivity over a particular 2731MIDI-capable hardware transport listed above, but does not support MIDI over that hardware transport, 2732it MUST NOT report support for feature android.software.midi. 2733</p> 2734 2735<p> 2736MIDI over Bluetooth LE acting in central role (section 7.4.3 Bluetooth) 2737is in trial use status. A device implementation that reports 2738feature android.software.midi, and which provides generic non-MIDI connectivity 2739over Bluetooth LE, SHOULD support MIDI over Bluetooth LE. 2740</p> 2741 2742<h2 id="5_10_pro_audio">5.10. Professional Audio</h2> 2743 2744<p> 2745If a device implementation meets <em>all</em> of the following requirements, 2746it is STRONGLY RECOMMENDED to report support for feature android.hardware.audio.pro via the 2747android.content.pm.PackageManager class 2748[<a href="http://developer.android.com/reference/android/content/pm/PackageManager.html">Resources, 70</a>]. 2749</p> 2750 2751<ul> 2752 2753<li> 2754The device implementation MUST report support for feature android.hardware.audio.low_latency. 2755</li> 2756 2757<li> The continuous round-trip audio latency, as defined in section 5.6 Audio Latency, 2758MUST be 20 milliseconds or less and SHOULD be 10 milliseconds or less over at least one 2759supported path. 2760</li> 2761 2762<li> 2763If the device includes a 4 conductor 3.5mm audio jack, 2764the continuous round-trip audio latency MUST be 20 milliseconds or less over the audio jack path, 2765and SHOULD be 10 milliseconds or less over the audio jack path. 2766</li> 2767 2768<li> 2769The device implementation MUST include a USB port(s) supporting USB host mode and 2770USB peripheral mode. 2771</li> 2772 2773<li> 2774The USB host mode MUST implement the USB audio class. 2775</li> 2776 2777<li> 2778If the device includes an HDMI port, the device implementation 2779MUST support output in stereo and eight channels 2780at 20-bit or 24-bit depth and 192 kHz without bit-depth loss or resampling. 2781</li> 2782 2783<li> 2784The device implementation MUST report support for feature android.software.midi. 2785</li> 2786 2787<li> 2788If the device includes a 4 conductor 3.5mm audio jack, 2789the device implementation is STRONGLY RECOMMENDED to comply with section 2790<a href="https://source.android.com/accessories/headset/specification.html#mobile_device_jack_specifications">Mobile device (jack) specifications</a> 2791of the 2792<a href="https://source.android.com/accessories/headset/specification.html">Wired Audio Headset Specification (v1.1)</a>. 2793</li> 2794 2795</ul> 2796 2797<h1 id="6_developer_tools_and_options_compatibility">6. Developer Tools and Options Compatibility</h1> 2798 2799<h2 id="6_1_developer_tools">6.1. Developer Tools</h2> 2800 2801<p>Device implementations MUST support the Android Developer Tools provided in the 2802Android SDK. Android compatible devices MUST be compatible with:</p> 2803 2804<ul> 2805 <li><strong>Android Debug Bridge (adb)</strong> [<a href="http://developer.android.com/tools/help/adb.html">Resources, 72</a>]</li> 2806</ul> 2807 2808<p>Device implementations MUST support all adb functions as documented in the 2809Android SDK including dumpsys [<a href="https://source.android.com/devices/input/diagnostics.html">Resources, 73</a>]. The device-side adb daemon MUST be inactive by default and there MUST be a 2810user-accessible mechanism to turn on the Android Debug Bridge. If a device 2811implementation omits USB peripheral mode, it MUST implement the Android Debug 2812Bridge via local-area network (such as Ethernet or 802.11). </p> 2813 2814<p>Android includes support for secure adb. Secure adb enables adb on known 2815authenticated hosts. Device implementations MUST support secure adb.</p> 2816 2817<ul> 2818 <li><strong>Dalvik Debug Monitor Service (ddms)</strong> [<a href="http://developer.android.com/tools/debugging/ddms.html">Resources, 74</a>]</li> 2819</ul> 2820 2821<p>Device implementations MUST support all ddms features as documented in the 2822Android SDK. As ddms uses adb, support for ddms SHOULD be inactive by default, 2823but MUST be supported whenever the user has activated the Android Debug Bridge, 2824as above.</p> 2825 2826<ul> 2827 <li><strong>Monkey</strong> [<a href="http://developer.android.com/tools/help/monkey.html">Resources, 75</a>]</li> 2828</ul> 2829 2830<p>Device implementations MUST include the Monkey framework, and make it available 2831for applications to use.</p> 2832 2833<ul> 2834 <li><strong>SysTrace</strong> [<a href="http://developer.android.com/tools/help/systrace.html">Resources, 76</a>]</li> 2835</ul> 2836 2837<p>Device implementations MUST support systrace tool as documented in the Android 2838SDK. Systrace must be inactive by default, and there MUST be a user-accessible 2839mechanism to turn on Systrace.</p> 2840 2841<p>Most Linux-based systems and Apple Macintosh systems recognize Android devices 2842using the standard Android SDK tools, without additional support; however 2843Microsoft Windows systems typically require a driver for new Android devices. 2844(For instance, new vendor IDs and sometimes new device IDs require custom USB 2845drivers for Windows systems.) If a device implementation is unrecognized by the 2846adb tool as provided in the standard Android SDK, device implementers MUST 2847provide Windows drivers allowing developers to connect to the device using the 2848adb protocol. These drivers MUST be provided for Windows XP, Windows Vista, 2849Windows 7, Windows 8 and Windows 10 in both 32-bit and 64-bit versions. 2850</p> 2851 2852<h2 id="6_2_developer_options">6.2. Developer Options</h2> 2853 2854 2855<p>Android includes support for developers to configure application 2856development-related settings. Device implementations MUST honor the 2857android.settings.APPLICATION_DEVELOPMENT_SETTINGS intent to show application 2858development-related settings [<a href="http://developer.android.com/reference/android/provider/Settings.html#ACTION_APPLICATION_DEVELOPMENT_SETTINGS">Resources, 77</a>]. The upstream Android implementation hides the Developer Options menu by 2859default and enables users to launch Developer Options after pressing seven (7) 2860times on the <strong>Settings</strong> > <strong>About Device</strong> > <strong>Build Number</strong> menu item. Device implementations MUST provide a consistent experience for 2861Developer Options. Specifically, device implementations MUST hide Developer 2862Options by default and MUST provide a mechanism to enable Developer Options 2863that is consistent with the upstream Android implementation.</p> 2864 2865<h1 id="7_hardware_compatibility">7. Hardware Compatibility</h1> 2866 2867 2868<p>If a device includes a particular hardware component that has a corresponding 2869API for third-party developers, the device implementation MUST implement that 2870API as described in the Android SDK documentation. If an API in the SDK 2871interacts with a hardware component that is stated to be optional and the 2872device implementation does not possess that component:</p> 2873 2874<ul> 2875 <li>Complete class definitions (as documented by the SDK) for the component APIs 2876MUST still be presented. 2877 <li>The API’s behaviors MUST be implemented as no-ops in some reasonable fashion. 2878 <li>API methods MUST return null values where permitted by the SDK documentation. 2879 <li>API methods MUST return no-op implementations of classes where null values are 2880not permitted by the SDK documentation. 2881 <li>API methods MUST NOT throw exceptions not documented by the SDK documentation. 2882</ul> 2883 2884<p>A typical example of a scenario where these requirements apply is the telephony 2885API: even on non-phone devices, these APIs must be implemented as reasonable 2886no-ops.</p> 2887 2888<p>Device implementations MUST consistently report accurate hardware configuration 2889information via the getSystemAvailableFeatures() and hasSystemFeature(String) 2890methods on the android.content.pm.PackageManager class for the same build 2891fingerprint. [<a href="http://developer.android.com/reference/android/content/pm/PackageManager.html">Resources, 70</a>]</p> 2892 2893<h2 id="7_1_display_and_graphics">7.1. Display and Graphics</h2> 2894 2895 2896<p>Android includes facilities that automatically adjust application assets and UI 2897layouts appropriately for the device, to ensure that third-party applications 2898run well on a variety of hardware configurations [<a href="http://developer.android.com/guide/practices/screens_support.html">Resources, 78</a>]. Devices MUST properly implement these APIs and behaviors, as detailed in 2899this section.</p> 2900 2901<p>The units referenced by the requirements in this section are defined as 2902follows:</p> 2903 2904<ul> 2905 <li><strong>physical diagonal size</strong>. The distance in inches between two opposing corners of the illuminated portion 2906of the display.</li> 2907 <li><strong>dots per inch (dpi)</strong>. The number of pixels encompassed by a linear horizontal or vertical span of 29081”. Where dpi values are listed, both horizontal and vertical dpi must fall 2909within the range.</li> 2910 <li><strong>aspect ratio</strong>. The ratio of the pixels of the longer dimension 2911 to the shorter dimension of the screen. For example, a display of 480x854 pixels 2912 would be 854/480 = 1.779, or roughly “16:9”.</li> 2913 <li><strong>density-independent pixel (dp)</strong> The virtual pixel unit normalized to a 160 dpi screen, calculated as: pixels = 2914dps * (density/160).</li> 2915</ul> 2916 2917<h3 id="7_1_1_screen_configuration">7.1.1. Screen Configuration</h3> 2918 2919 2920<h4 id="7_1_1_1_screen_size">7.1.1.1. Screen Size</h4> 2921 2922<div class="note"> 2923<p>Android Watch devices (detailed in <a href="#2_device_types">section 2</a>) MAY have smaller screen sizes as described in this section.</p> 2924</div> 2925 2926<p>The Android UI framework supports a variety of different screen sizes, and 2927allows applications to query the device screen size (aka “screen layout") via 2928android.content.res.Configuration.screenLayout with the SCREENLAYOUT_SIZE_MASK. 2929Device implementations MUST report the correct screen size as defined in the 2930Android SDK documentation [<a href="http://developer.android.com/guide/practices/screens_support.html">Resources, 78</a>] and determined by the upstream Android platform. Specifically, device 2931implementations MUST report the correct screen size according to the following 2932logical density-independent pixel (dp) screen dimensions.</p> 2933 2934<ul> 2935 <li>Devices MUST have screen sizes of at least 426 dp x 320 dp (‘small’), unless it 2936is an Android Watch device.</li> 2937 <li>Devices that report screen size ‘normal’ MUST have screen sizes of at least 480 2938dp x 320 dp.</li> 2939 <li>Devices that report screen size ‘large’ MUST have screen sizes of at least 640 2940dp x 480 dp.</li> 2941 <li>Devices that report screen size ‘xlarge’ MUST have screen sizes of at least 960 2942dp x 720 dp.</li> 2943</ul> 2944 2945<p>In addition, </p> 2946 2947<ul> 2948 <li>Android Watch devices MUST have a screen with the physical diagonal size in the 2949range from 1.1 to 2.5 inches.</li> 2950 <li>Other types of Android device implementations, with a physically integrated 2951screen, MUST have a screen at least 2.5 inches in physical diagonal size.</li> 2952</ul> 2953 2954<p>Devices MUST NOT change their reported screen size at any time.</p> 2955 2956<p>Applications optionally indicate which screen sizes they support via the 2957<supports-screens> attribute in the AndroidManifest.xml file. Device 2958implementations MUST correctly honor applications' stated support for small, 2959normal, large, and xlarge screens, as described in the Android SDK 2960documentation.</p> 2961 2962<h4 id="7_1_1_2_screen_aspect_ratio">7.1.1.2. Screen Aspect Ratio</h4> 2963 2964<div class="note"> 2965<p>Android Watch devices MAY have an aspect ratio of 1.0 (1:1).</p> 2966</div> 2967 2968 2969<p>The screen aspect ratio MUST be a value from 1.3333 (4:3) to 1.86 (roughly 297016:9), but Android Watch devices MAY have an aspect ratio of 1.0 (1:1) because 2971such a device implementation will use a UI_MODE_TYPE_WATCH as the 2972android.content.res.Configuration.uiMode.</p> 2973 2974<h4 id="7_1_1_3_screen_density">7.1.1.3. Screen Density</h4> 2975 2976 2977<p>The Android UI framework defines a set of standard logical densities to help 2978application developers target application resources. Device implementations 2979MUST report only one of the following logical Android framework densities 2980through the android.util.DisplayMetrics APIs, and MUST execute applications at 2981this standard density and MUST NOT change the value at at any time for the 2982default display.</p> 2983 2984<ul> 2985 <li>120 dpi (ldpi)</li> 2986 <li>160 dpi (mdpi)</li> 2987 <li>213 dpi (tvdpi)</li> 2988 <li>240 dpi (hdpi)</li> 2989 <li>280 dpi (280dpi)</li> 2990 <li>320 dpi (xhdpi)</li> 2991 <li>360 dpi (360dpi)</li> 2992 <li>400 dpi (400dpi)</li> 2993 <li>420 dpi (420dpi)</li> 2994 <li>480 dpi (xxhdpi)</li> 2995 <li>560 dpi (560dpi)</li> 2996 <li>640 dpi (xxxhdpi)</li> 2997</ul> 2998 2999<p>Device implementations SHOULD define the standard Android framework density 3000that is numerically closest to the physical density of the screen, unless that 3001logical density pushes the reported screen size below the minimum supported. If 3002the standard Android framework density that is numerically closest to the 3003physical density results in a screen size that is smaller than the smallest 3004supported compatible screen size (320 dp width), device implementations SHOULD 3005report the next lowest standard Android framework density.</p> 3006 3007<h3 id="7_1_2_display_metrics">7.1.2. Display Metrics</h3> 3008 3009 3010<p>Device implementations MUST report correct values for all display metrics 3011defined in android.util.DisplayMetrics [<a href="http://developer.android.com/reference/android/util/DisplayMetrics.html">Resources, 79</a>] and MUST report the same values regardless of whether the embedded or 3012external screen is used as the default display.</p> 3013 3014<h3 id="7_1_3_screen_orientation">7.1.3. Screen Orientation</h3> 3015 3016 3017<p>Devices MUST report which screen orientations they support 3018(android.hardware.screen.portrait and/or android.hardware.screen.landscape) and 3019MUST report at least one supported orientation. For example, a device with a 3020fixed orientation landscape screen, such as a television or laptop, SHOULD only 3021report android.hardware.screen.landscape.</p> 3022 3023<p>Devices that report both screen orientations MUST support dynamic orientation 3024by applications to either portrait or landscape screen orientation. That is, 3025the device must respect the application’s request for a specific screen 3026orientation. Device implementations MAY select either portrait or landscape 3027orientation as the default.</p> 3028 3029<p>Devices MUST report the correct value for the device’s current orientation, 3030whenever queried via the android.content.res.Configuration.orientation, 3031android.view.Display.getOrientation(), or other APIs.</p> 3032 3033<p>Devices MUST NOT change the reported screen size or density when changing 3034orientation.</p> 3035 3036<h3 id="7_1_4_2d_and_3d_graphics_acceleration">7.1.4. 2D and 3D Graphics Acceleration</h3> 3037 3038 3039<p>Device implementations MUST support both OpenGL ES 1.0 and 2.0, as embodied and 3040detailed in the Android SDK documentations. Device implementations SHOULD 3041support OpenGL ES 3.0 or 3.1 on devices capable of supporting it. Device 3042implementations MUST also support Android RenderScript, as detailed in the 3043Android SDK documentation [<a href="http://developer.android.com/guide/topics/renderscript/">Resources, 80</a>].</p> 3044 3045<p>Device implementations MUST also correctly identify themselves as supporting 3046OpenGL ES 1.0, OpenGL ES 2.0, OpenGL ES 3.0 or OpenGL 3.1. That is:</p> 3047 3048<ul> 3049 <li>The managed APIs (such as via the GLES10.getString() method) MUST report support 3050for OpenGL ES 1.0 and OpenGL ES 2.0.</li> 3051 <li>The native C/C++ OpenGL APIs (APIs available to apps via libGLES_v1CM.so, 3052libGLES_v2.so, or libEGL.so) MUST report support for OpenGL ES 1.0 and OpenGL 3053ES 2.0.</li> 3054 <li>Device implementations that declare support for OpenGL ES 3.0 or 3.1 MUST 3055support the corresponding managed APIs and include support for native C/C++ 3056APIs. On device implementations that declare support for OpenGL ES 3.0 or 3.1, 3057libGLESv2.so MUST export the corresponding function symbols in addition to the 3058OpenGL ES 2.0 function symbols.</li> 3059</ul> 3060 3061<p>In addition to OpenGL ES 3.1, Android provides an extension pack with Java 3062interfaces [<a href="https://developer.android.com/reference/android/opengl/GLES31Ext.html">Resources, 81</a>] and native support for advanced graphics functionality such as tessellation 3063and the ASTC texture compression format. Android device implementations MAY 3064support this extension pack, and—only if fully implemented—MUST identify the 3065support through the android.hardware.opengles.aep feature flag.</p> 3066 3067<p>Also, device implementations MAY implement any desired OpenGL ES extensions. 3068However, device implementations MUST report via the OpenGL ES managed and 3069native APIs all extension strings that they do support, and conversely MUST NOT 3070report extension strings that they do not support.</p> 3071 3072<p>Note that Android includes support for applications to optionally specify that 3073they require specific OpenGL texture compression formats. These formats are 3074typically vendor-specific. Device implementations are not required by Android 3075to implement any specific texture compression format. However, they SHOULD 3076accurately report any texture compression formats that they do support, via the 3077getString() method in the OpenGL API.</p> 3078 3079<p>Android includes a mechanism for applications to declare that they want to 3080enable hardware acceleration for 2D graphics at the Application, Activity, 3081Window, or View level through the use of a manifest tag 3082android:hardwareAccelerated or direct API calls [<a href="http://developer.android.com/guide/topics/graphics/hardware-accel.html">Resources, 82</a>].</p> 3083 3084<p>Device implementations MUST enable hardware acceleration by default, and MUST 3085disable hardware acceleration if the developer so requests by setting 3086android:hardwareAccelerated="false” or disabling hardware acceleration directly 3087through the Android View APIs.</p> 3088 3089<p>In addition, device implementations MUST exhibit behavior consistent with the 3090Android SDK documentation on hardware acceleration [<a href="http://developer.android.com/guide/topics/graphics/hardware-accel.html">Resources, 82</a>].</p> 3091 3092<p>Android includes a TextureView object that lets developers directly integrate 3093hardware-accelerated OpenGL ES textures as rendering targets in a UI hierarchy. 3094Device implementations MUST support the TextureView API, and MUST exhibit 3095consistent behavior with the upstream Android implementation.</p> 3096 3097<p>Android includes support for EGL_ANDROID_RECORDABLE, an EGLConfig attribute 3098that indicates whether the EGLConfig supports rendering to an ANativeWindow 3099that records images to a video. Device implementations MUST support 3100EGL_ANDROID_RECORDABLE extension [<a href="https://www.khronos.org/registry/egl/extensions/ANDROID/EGL_ANDROID_recordable.txt">Resources, 83</a>].</p> 3101 3102<h3 id="7_1_5_legacy_application_compatibility_mode">7.1.5. Legacy Application Compatibility Mode</h3> 3103 3104 3105<p>Android specifies a “compatibility mode” in which the framework operates in a 3106'normal' screen size equivalent (320dp width) mode for the benefit of legacy 3107applications not developed for old versions of Android that pre-date 3108screen-size independence.</p> 3109 3110<ul> 3111<li>Android Automotive does not support legacy compatibility mode.</li> 3112<li>All other device implementations MUST include support for legacy application 3113compatibility mode as implemented by the upstream Android open source code. That 3114is, device implementations MUST NOT alter the triggers or thresholds at which 3115compatibility mode is activated, and MUST NOT alter the behavior of the 3116compatibility mode itself.</li> 3117</ul> 3118 3119<h3 id="7_1_6_screen_technology">7.1.6. Screen Technology</h3> 3120 3121 3122<p>The Android platform includes APIs that allow applications to render rich 3123graphics to the display. Devices MUST support all of these APIs as defined by 3124the Android SDK unless specifically allowed in this document. </p> 3125 3126<ul> 3127 <li>Devices MUST support displays capable of rendering 16-bit color graphics and 3128SHOULD support displays capable of 24-bit color graphics.</li> 3129 <li>Devices MUST support displays capable of rendering animations.</li> 3130 <li>The display technology used MUST have a pixel aspect ratio (PAR) between 0.9 3131and 1.15. That is, the pixel aspect ratio MUST be near square (1.0) with a 10 ~ 313215% tolerance.</li> 3133</ul> 3134 3135<h3 id="7_1_7_external_displays">7.1.7. Secondary Displays</h3> 3136 3137 3138<p>Android includes support for secondary display to enable media sharing 3139capabilities and developer APIs for accessing external displays. If a device 3140supports an external display either via a wired, wireless, or an embedded 3141additional display connection then the device implementation MUST implement the 3142display manager API as described in the Android SDK documentation [<a href="http://developer.android.com/reference/android/hardware/display/DisplayManager.html">Resources, 84</a>].</p> 3143 3144<h2 id="7_2_input_devices">7.2. Input Devices</h2> 3145 3146<p>Devices MUST support a touchscreen or meet the requirements listed in 7.2.2 3147for non-touch navigation.</p> 3148 3149<h3 id="7_2_1_keyboard">7.2.1. Keyboard</h3> 3150 3151<div class="note"> 3152<p>Android Watch and Android Automotive implementations MAY implement a soft 3153keyboard. All other device implementations MUST implement a soft keyboard and:</p> 3154</div> 3155 3156 3157<p>Device implementations:</p> 3158 3159<ul> 3160 <li>MUST include support for the Input Management Framework (which allows 3161third-party developers to create Input Method Editors—i.e. soft keyboard) as 3162detailed at <a href="http://developer.android.com">http://developer.android.com</a>.</li> 3163 <li>MUST provide at least one soft keyboard implementation (regardless of whether a 3164hard keyboard is present) except for Android Watch devices where the screen 3165size makes it less reasonable to have a soft keyboard.</li> 3166 <li>MAY include additional soft keyboard implementations.</li> 3167 <li>MAY include a hardware keyboard.</li> 3168 <li>MUST NOT include a hardware keyboard that does not match one of the formats 3169specified in android.content.res.Configuration.keyboard [<a href="http://developer.android.com/reference/android/content/res/Configuration.html">Resources, 85</a>] (QWERTY or 12-key).</li> 3170</ul> 3171 3172<h3 id="7_2_2_non-touch_navigation">7.2.2. Non-touch Navigation</h3> 3173 3174<div class="note"> 3175<p>Android Television devices MUST support D-pad.</p> 3176</div> 3177 3178<p>Device implementations:</p> 3179 3180<ul> 3181 <li>MAY omit a non-touch navigation option (trackball, d-pad, or wheel) if the 3182device implementation is not an Android Television device.</li> 3183 <li>MUST report the correct value for android.content.res.Configuration.navigation 3184[<a href="http://developer.android.com/reference/android/content/res/Configuration.html">Resources, 85</a>].</li> 3185 <li>MUST provide a reasonable alternative user interface mechanism for the 3186selection and editing of text, compatible with Input Management Engines. The 3187upstream Android open source implementation includes a selection mechanism 3188suitable for use with devices that lack non-touch navigation inputs.</li> 3189</ul> 3190 3191<h3 id="7_2_3_navigation_keys">7.2.3. Navigation Keys</h3> 3192 3193<div class="note"> 3194<p>The availability and visibility requirement of the Home, Recents, and Back 3195functions differ between device types as described in this section.</p> 3196</div> 3197 3198<p>The Home, Recents, and Back functions (mapped to the key events KEYCODE_HOME, 3199KEYCODE_APP_SWITCH, KEYCODE_BACK, respectively) are essential to the Android 3200navigation paradigm and therefore:</p> 3201 3202<ul> 3203 <li>Android Handheld device implementations MUST provide the Home, Recents, and 3204Back functions.</li> 3205 <li>Android Television device implementations MUST provide the Home and Back 3206functions.</li> 3207 <li>Android Watch device implementations MUST have the Home function available to 3208the user, and the Back function except for when it is in UI_MODE_TYPE_WATCH.</li> 3209 <li>Android Automotive implementations MUST provide the Home function and MAY 3210provide Back and Recent functions.</li> 3211 <li>All other types of device implementations MUST provide the Home and Back 3212functions.</li> 3213</ul> 3214 3215<p>These functions MAY be implemented via dedicated physical buttons (such as 3216mechanical or capacitive touch buttons), or MAY be implemented using dedicated 3217software keys on a distinct portion of the screen, gestures, touch panel, etc. 3218Android supports both implementations. All of these functions MUST be 3219accessible with a single action (e.g. tap, double-click or gesture) when 3220visible.</p> 3221 3222<p>Recents function, if provided, MUST have a visible button or icon unless hidden 3223together with other navigation functions in full-screen mode. This does not 3224apply to devices upgrading from earlier Android versions that have physical 3225buttons for navigation and no recents key.</p> 3226 3227<p> The Home and Back functions, if provided, MUST each have a visible button or 3228icon unless hidden together with other navigation functions in full-screen mode 3229or when the uiMode UI_MODE_TYPE_MASK is set to UI_MODE_TYPE_WATCH.</p> 3230 3231<p>The Menu function is deprecated in favor of action bar since Android 4.0. 3232Therefore the new device implementations shipping with Android 6.0 and later MUST NOT 3233implement a dedicated physical button for the Menu function. Older device 3234implementations SHOULD NOT implement a dedicated physical button for the Menu 3235function, but if the physical Menu button is implemented and the device is 3236running applications with targetSdkVersion > 10, the device implementation:</p> 3237 3238<ul> 3239 <li>MUST display the action overflow button on the action bar when it is visible 3240and the resulting action overflow menu popup is not empty. For a device 3241implementation launched before Android 4.4 but upgrading to Android 6.0, this 3242is RECOMMENDED.</li> 3243 <li>MUST NOT modify the position of the action overflow popup displayed by 3244selecting the overflow button in the action bar.</li> 3245 <li>MAY render the action overflow popup at a modified position on the screen when 3246it is displayed by selecting the physical menu button.</li> 3247</ul> 3248 3249<p>For backwards compatibility, device implementations MUST make the Menu function 3250available to applications when targetSdkVersion is less than 10, either by a physical 3251button, a software key, or gestures. This Menu function should be presented 3252unless hidden together with other navigation functions.</p> 3253 3254<p>Android device implementations with the support of the Assist action [<a 3255href="http://developer.android.com/reference/android/content/Intent.html#ACTION_ASSIST">Resources, 325630</a>] MUST make this accessible with a single action (e.g. tap, double-click, 3257or gesture) when other navigation keys are visible, and are STRONGLY RECOMMENDED to 3258use the long-press on the Home button or software key as the single action.</p> 3259 3260<p>Device implementations MAY use a distinct portion of the screen to display the 3261navigation keys, but if so, MUST meet these requirements:</p> 3262 3263<ul> 3264 <li>Device implementation navigation keys MUST use a distinct portion of the 3265screen, not available to applications, and MUST NOT obscure or otherwise 3266interfere with the portion of the screen available to applications.</li> 3267 <li>Device implementations MUST make available a portion of the display to 3268applications that meets the requirements defined in <a href="#7_1_1_screen_configuration">section 7.1.1</a>.</li> 3269 <li>Device implementations MUST display the navigation keys when applications do 3270not specify a system UI mode, or specify SYSTEM_UI_FLAG_VISIBLE.</li> 3271 <li>Device implementations MUST present the navigation keys in an unobtrusive “low 3272profile” (eg. dimmed) mode when applications specify 3273SYSTEM_UI_FLAG_LOW_PROFILE.</li> 3274 <li>Device implementations MUST hide the navigation keys when applications specify 3275SYSTEM_UI_FLAG_HIDE_NAVIGATION.</li> 3276</ul> 3277 3278<h3 id="7_2_4_touchscreen_input">7.2.4. Touchscreen Input</h3> 3279 3280<div class="note"> 3281<p>Android Handhelds and Watch Devices MUST support touchscreen input.</p> 3282</div> 3283 3284 3285<p>Device implementations SHOULD have a pointer input system of some kind (either 3286mouse-like or touch). However, if a device implementation does not support a 3287pointer input system, it MUST NOT report the android.hardware.touchscreen or 3288android.hardware.faketouch feature constant. Device implementations that do 3289include a pointer input system:</p> 3290 3291<ul> 3292 <li>SHOULD support fully independently tracked pointers, if the device input system 3293supports multiple pointers.</li> 3294 <li>MUST report the value of android.content.res.Configuration.touchscreen [<a href="http://developer.android.com/reference/android/content/res/Configuration.html">Resources, 85</a>] corresponding to the type of the specific touchscreen on the device.</li> 3295</ul> 3296 3297<p>Android includes support for a variety of touchscreens, touch pads, and fake 3298touch input devices. Touchscreen based device implementations are associated 3299with a display [<a href="http://source.android.com/devices/tech/input/touch-devices.html">Resources, 86</a>] such that the user has the impression of directly manipulating items on 3300screen. Since the user is directly touching the screen, the system does not 3301require any additional affordances to indicate the objects being manipulated. 3302In contrast, a fake touch interface provides a user input system that 3303approximates a subset of touchscreen capabilities. For example, a mouse or 3304remote control that drives an on-screen cursor approximates touch, but requires 3305the user to first point or focus then click. Numerous input devices like the 3306mouse, trackpad, gyro-based air mouse, gyro-pointer, joystick, and multi-touch 3307trackpad can support fake touch interactions. Android includes the feature 3308constant android.hardware.faketouch, which corresponds to a high-fidelity 3309non-touch (pointer-based) input device such as a mouse or trackpad that can 3310adequately emulate touch-based input (including basic gesture support), and 3311indicates that the device supports an emulated subset of touchscreen 3312functionality. Device implementations that declare the fake touch feature MUST 3313meet the fake touch requirements in <a href="#7_2_5_fake_touch_input">section 7.2.5</a>.</p> 3314 3315<p>Device implementations MUST report the correct feature corresponding to the 3316type of input used. Device implementations that include a touchscreen 3317(single-touch or better) MUST report the platform feature constant 3318android.hardware.touchscreen. Device implementations that report the platform 3319feature constant android.hardware.touchscreen MUST also report the platform 3320feature constant android.hardware.faketouch. Device implementations that do not 3321include a touchscreen (and rely on a pointer device only) MUST NOT report any 3322touchscreen feature, and MUST report only android.hardware.faketouch if they 3323meet the fake touch requirements in <a href="#7_2_5_fake_touch_input">section 7.2.5</a>.</p> 3324 3325<h3 id="7_2_5_fake_touch_input">7.2.5. Fake Touch Input</h3> 3326 3327 3328<p>Device implementations that declare support for android.hardware.faketouch:</p> 3329 3330<ul> 3331 <li>MUST report the absolute X and Y screen positions of the pointer location and 3332display a visual pointer on the screen [<a href="http://developer.android.com/reference/android/view/MotionEvent.html">Resources, 87</a>].</li> 3333 <li>MUST report touch event with the action code that specifies the state change 3334that occurs on the pointer going down or up on the screen [<a href="http://developer.android.com/reference/android/view/MotionEvent.html">Resources, 87</a>].</li> 3335 <li>MUST support pointer down and up on an object on the screen, which allows users 3336to emulate tap on an object on the screen.</li> 3337 <li>MUST support pointer down, pointer up, pointer down then pointer up in the same 3338place on an object on the screen within a time threshold, which allows users to 3339emulate double tap on an object on the screen [<a href="http://developer.android.com/reference/android/view/MotionEvent.html">Resources, 87</a>].</li> 3340 <li>MUST support pointer down on an arbitrary point on the screen, pointer move to 3341any other arbitrary point on the screen, followed by a pointer up, which allows 3342users to emulate a touch drag.</li> 3343 <li>MUST support pointer down then allow users to quickly move the object to a 3344different position on the screen and then pointer up on the screen, which 3345allows users to fling an object on the screen.</li> 3346</ul> 3347 3348<p>Devices that declare support for android.hardware.faketouch.multitouch.distinct 3349MUST meet the requirements for faketouch above, and MUST also support distinct 3350tracking of two or more independent pointer inputs.</p> 3351 3352<h3 id="7_2_6_game_controller_support">7.2.6. Game Controller Support</h3> 3353 3354 3355<p>Android Television device implementations MUST support button mappings for game 3356controllers as listed below. The upstream Android implementation includes 3357implementation for game controllers that satisfies this requirement. </p> 3358 3359<h4 id="7_2_6_1_button_mappings">7.2.6.1. Button Mappings</h4> 3360 3361 3362<p>Android Television device implementations MUST support the following key 3363mappings:</p> 3364<table> 3365 <tr> 3366 <th>Button</th> 3367 <th>HID Usage<sup>2</sup></th> 3368 <th>Android Button</th> 3369 </tr> 3370 <tr> 3371 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BUTTON_A">A</a><sup>1</sup></td> 3372 <td>0x09 0x0001</td> 3373 <td>KEYCODE_BUTTON_A (96)</td> 3374 </tr> 3375 <tr> 3376 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BUTTON_B">B</a><sup>1</sup></td> 3377 <td>0x09 0x0002</td> 3378 <td>KEYCODE_BUTTON_B (97)</td> 3379 </tr> 3380 <tr> 3381 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BUTTON_X">X</a><sup>1</sup></td> 3382 <td>0x09 0x0004</td> 3383 <td>KEYCODE_BUTTON_X (99)</td> 3384 </tr> 3385 <tr> 3386 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BUTTON_Y">Y</a><sup>1</sup></td> 3387 <td>0x09 0x0005</td> 3388 <td>KEYCODE_BUTTON_Y (100)</td> 3389 </tr> 3390 <tr> 3391 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_DPAD_UP">D-pad up</a><sup>1</sup><br /> 3392 3393<a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_DPAD_DOWN">D-pad down</a><sup>1</sup></td> 3394 <td>0x01 0x0039<sup>3</sup></td> 3395 <td><a href="http://developer.android.com/reference/android/view/MotionEvent.html#AXIS_HAT_Y">AXIS_HAT_Y</a><sup>4</sup></td> 3396 </tr> 3397 <tr> 3398 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_DPAD_LEFT">D-pad left</a>1<br /> 3399 3400<a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_DPAD_RIGHT">D-pad right</a><sup>1</sup></td> 3401 <td>0x01 0x0039<sup>3</sup></td> 3402 <td><a href="http://developer.android.com/reference/android/view/MotionEvent.html#AXIS_HAT_X">AXIS_HAT_X</a><sup>4</sup></td> 3403 </tr> 3404 <tr> 3405 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BUTTON_L1">Left shoulder button</a><sup>1</sup></td> 3406 <td>0x09 0x0007</td> 3407 <td>KEYCODE_BUTTON_L1 (102)</td> 3408 </tr> 3409 <tr> 3410 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BUTTON_R1">Right shoulder button</a><sup>1</sup></td> 3411 <td>0x09 0x0008</td> 3412 <td>KEYCODE_BUTTON_R1 (103)</td> 3413 </tr> 3414 <tr> 3415 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BUTTON_THUMBL">Left stick click</a><sup>1</sup></td> 3416 <td>0x09 0x000E</td> 3417 <td>KEYCODE_BUTTON_THUMBL (106)</td> 3418 </tr> 3419 <tr> 3420 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BUTTON_THUMBR">Right stick click</a><sup>1</sup></td> 3421 <td>0x09 0x000F</td> 3422 <td>KEYCODE_BUTTON_THUMBR (107)</td> 3423 </tr> 3424 <tr> 3425 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_HOME">Home</a><sup>1</sup></td> 3426 <td>0x0c 0x0223</td> 3427 <td>KEYCODE_HOME (3)</td> 3428 </tr> 3429 <tr> 3430 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BACK">Back</a><sup>1</sup></td> 3431 <td>0x0c 0x0224</td> 3432 <td>KEYCODE_BACK (4)</td> 3433 </tr> 3434</table> 3435 3436 3437<p class="table_footnote">1 [<a href="http://developer.android.com/reference/android/view/KeyEvent.html">Resources, 88</a>]</p> 3438 3439<p class="table_footnote">2 The above HID usages must be declared within a Game pad CA (0x01 0x0005).</p> 3440 3441<p class="table_footnote">3 This usage must have a Logical Minimum of 0, a Logical Maximum of 7, a 3442Physical Minimum of 0, a Physical Maximum of 315, Units in Degrees, and a 3443Report Size of 4. The logical value is defined to be the clockwise rotation 3444away from the vertical axis; for example, a logical value of 0 represents no 3445rotation and the up button being pressed, while a logical value of 1 represents 3446a rotation of 45 degrees and both the up and left keys being pressed.</p> 3447 3448<p class="table_footnote">4 [<a href="http://developer.android.com/reference/android/view/MotionEvent.html">Resources, 87</a>]</p> 3449 3450<table> 3451 <tr> 3452 <th>Analog Controls<sup>1</sup></th> 3453 <th>HID Usage</th> 3454 <th>Android Button</th> 3455 </tr> 3456 <tr> 3457 <td><a href="http://developer.android.com/reference/android/view/MotionEvent.html#AXIS_LTRIGGER">Left Trigger</a></td> 3458 <td>0x02 0x00C5</td> 3459 <td>AXIS_LTRIGGER </td> 3460 </tr> 3461 <tr> 3462 <td><a href="http://developer.android.com/reference/android/view/MotionEvent.html#AXIS_THROTTLE">Right Trigger</a></td> 3463 <td>0x02 0x00C4</td> 3464 <td>AXIS_RTRIGGER </td> 3465 </tr> 3466 <tr> 3467 <td><a href="http://developer.android.com/reference/android/view/MotionEvent.html#AXIS_Y">Left Joystick</a></td> 3468 <td>0x01 0x0030<br /> 3469 34700x01 0x0031</td> 3471 <td>AXIS_X<br /> 3472 3473AXIS_Y</td> 3474 </tr> 3475 <tr> 3476 <td><a href="http://developer.android.com/reference/android/view/MotionEvent.html#AXIS_Z">Right Joystick</a></td> 3477 <td>0x01 0x0032<br /> 3478 34790x01 0x0035</td> 3480 <td>AXIS_Z<br /> 3481 3482AXIS_RZ</td> 3483 </tr> 3484</table> 3485 3486 3487<p class="table_footnote">1 [<a href="http://developer.android.com/reference/android/view/MotionEvent.html">Resources, 87</a>]</p> 3488 3489<h3 id="7_2_7_remote_control">7.2.7. Remote Control</h3> 3490 3491 3492<p>Android Television device implementations SHOULD provide a remote control to 3493allow users to access the TV interface. The remote control MAY be a physical 3494remote or can be a software-based remote that is accessible from a mobile phone 3495or tablet. The remote control MUST meet the requirements defined below.</p> 3496 3497<ul> 3498 <li><strong>Search affordance</strong>. Device implementations MUST fire KEYCODE_SEARCH when the user invokes voice search either on the physical or software-based remote.</li> 3499 <li><strong>Navigation</strong>. All Android Television remotes MUST include Back, Home, and Select buttons and 3500support for D-pad events [<a href="http://developer.android.com/reference/android/view/KeyEvent.html">Resources, 88</a>].</li> 3501</ul> 3502 3503<h2 id="7_3_sensors">7.3. Sensors</h2> 3504 3505 3506<p>Android includes APIs for accessing a variety of sensor types. Devices 3507implementations generally MAY omit these sensors, as provided for in the 3508following subsections. If a device includes a particular sensor type that has a 3509corresponding API for third-party developers, the device implementation MUST 3510implement that API as described in the Android SDK documentation and the 3511Android Open Source documentation on sensors [<a href="http://source.android.com/devices/sensors/">Resources, 89</a>]. For example, device implementations:</p> 3512 3513<ul> 3514 <li>MUST accurately report the presence or absence of sensors per the 3515android.content.pm.PackageManager class [<a href="http://developer.android.com/reference/android/content/pm/PackageManager.html">Resources, 70]</a>.</li> 3516 <li>MUST return an accurate list of supported sensors via the 3517SensorManager.getSensorList() and similar methods.</li> 3518 <li>MUST behave reasonably for all other sensor APIs (for example, by returning 3519true or false as appropriate when applications attempt to register listeners, 3520not calling sensor listeners when the corresponding sensors are not present; 3521etc.).</li> 3522 <li>MUST report all sensor measurements using the relevant International System of 3523Units (metric) values for each sensor type as defined in the Android SDK 3524documentation [<a href="http://developer.android.com/reference/android/hardware/SensorEvent.html">Resources, 90</a>].</li> 3525 <li>SHOULD report the event time in nanoseconds as defined in the Android SDK 3526documentation, representing the time the event happened and synchronized with 3527the SystemClock.elapsedRealtimeNano() clock. Existing and new Android devices 3528are <strong>STRONGLY RECOMMENDED</strong> to meet these requirement so they will be able to upgrade to the future 3529platform releases where this might become a REQUIRED component. The 3530synchronization error SHOULD be below 100 milliseconds [<a href="http://developer.android.com/reference/android/hardware/SensorEvent.html#timestamp">Resources, 91</a>].</li> 3531 <li>MUST report sensor data with a maximum latency of 100 milliseconds + 2 * sample_time for the case of a sensor streamed 3532 with a minimum required latency of 5 ms + 2 * sample_time when the application processor is active. This delay does not include any filtering delays.</li> 3533 <li>MUST report the first sensor sample within 400 milliseconds + 2 * sample_time of the sensor being activated. It is acceptable for this sample to have an accuracy of 0.</li> 3534</ul> 3535 3536<p>The list above is not comprehensive; the documented behavior of the Android SDK 3537and the Android Open Source Documentations on Sensors [<a href="http://source.android.com/devices/sensors/">Resources, 89</a>] is to be considered authoritative.</p> 3538 3539<p>Some sensor types are composite, meaning they can be derived from data provided 3540by one or more other sensors. (Examples include the orientation sensor, and the 3541linear acceleration sensor.) Device implementations SHOULD implement these 3542sensor types, when they include the prerequisite physical sensors as described 3543in [<a href="https://source.android.com/devices/sensors/sensor-types.html">Resources, 92</a>]. 3544If a device implementation includes a composite sensor it MUST implement the 3545sensor as described in the Android Open Source documentation on composite 3546sensors [<a href="https://source.android.com/devices/sensors/sensor-types.html#composite_sensor_type_summary">Resources, 92</a>].</p> 3547 3548<p>Some Android sensors support a “continuous” trigger mode, which returns data 3549continuously [<a href="https://source.android.com/devices/sensors/report-modes.html#continuous">Resources, 93</a>]. For any API indicated by the Android SDK documentation to be a continuous 3550sensor, device implementations MUST continuously provide periodic data samples 3551that SHOULD have a jitter below 3%, where jitter is defined as the standard 3552deviation of the difference of the reported timestamp values between 3553consecutive events.</p> 3554 3555<p>Note that the device implementations MUST ensure that the sensor event stream 3556MUST NOT prevent the device CPU from entering a suspend state or waking up from 3557a suspend state.</p> 3558 3559<p>Finally, when several sensors are activated, the power consumption SHOULD NOT 3560exceed the sum of the individual sensor’s reported power consumption.</p> 3561 3562<h3 id="7_3_1_accelerometer">7.3.1. Accelerometer</h3> 3563 3564 3565<p>Device implementations SHOULD include a 3-axis accelerometer. Android Handheld 3566devices and Android Watch devices are STRONGLY RECOMMENDED to include this 3567sensor. If a device implementation does include a 3-axis accelerometer, it:</p> 3568 3569<ul> 3570 <li>MUST implement and report TYPE_ACCELEROMETER sensor [<a href="http://developer.android.com/reference/android/hardware/Sensor.html#TYPE_ACCELEROMETER">Resources, 94</a>].</li> 3571 <li>MUST be able to report events up to a frequency of at least 50 Hz for 3572 Android Watch devices as such devices have a stricter power constraint and 3573 100 Hz for all other device types.</li> 3574 <li>SHOULD report events up to at least 200 Hz.</li> 3575 <li>MUST comply with the Android sensor coordinate system as detailed in the 3576Android APIs [<a href="http://developer.android.com/reference/android/hardware/SensorEvent.html">Resources, 90</a>].</li> 3577 <li>MUST be capable of measuring from freefall up to four times the gravity (4g) or 3578more on any axis.</li> 3579 <li>MUST have a resolution of at least 12-bits and SHOULD have a resolution of at 3580least 16-bits.</li> 3581 <li>SHOULD be calibrated while in use if the characteristics changes over the life 3582cycle and compensated, and preserve the compensation parameters between device 3583reboots.</li> 3584 <li>SHOULD be temperature compensated.</li> 3585 <li>MUST have a standard deviation no greater than 0.05 m/s^, where the standard 3586deviation should be calculated on a per axis basis on samples collected over a 3587period of at least 3 seconds at the fastest sampling rate.</li> 3588 <li>SHOULD implement the TYPE_SIGNIFICANT_MOTION, TYPE_TILT_DETECTOR, 3589TYPE_STEP_DETECTOR, TYPE_STEP_COUNTER composite sensors as described in the 3590Android SDK document. Existing and new Android devices are <strong>STRONGLY RECOMMENDED</strong> to implement the TYPE_SIGNIFICANT_MOTION composite sensor. If any of these 3591sensors are implemented, the sum of their power consumption MUST always be less 3592than 4 mW and SHOULD each be below 2 mW and 0.5 mW for when the device is in a 3593dynamic or static condition.</li> 3594 <li>If a gyroscope sensor is included, MUST implement the TYPE_GRAVITY and 3595TYPE_LINEAR_ACCELERATION composite sensors and SHOULD implement the 3596TYPE_GAME_ROTATION_VECTOR composite sensor. Existing and new Android devices 3597are STRONGLY RECOMMENDED to implement the TYPE_GAME_ROTATION_VECTOR sensor.</li> 3598 <li>MUST implement a TYPE_ROTATION_VECTOR composite sensor, if a gyroscope sensor 3599and a magnetometer sensor is also included.</li> 3600</ul> 3601 3602<h3 id="7_3_2_magnetometer">7.3.2. Magnetometer</h3> 3603 3604 3605<p>Device implementations SHOULD include a 3-axis magnetometer (compass). If a 3606device does include a 3-axis magnetometer, it:</p> 3607 3608<ul> 3609 <li>MUST implement the TYPE_MAGNETIC_FIELD sensor and SHOULD also implement 3610TYPE_MAGNETIC_FIELD_UNCALIBRATED sensor. Existing and new Android devices are 3611STRONGLY RECOMMENDED to implement the TYPE_MAGNETIC_FIELD_UNCALIBRATED sensor.</li> 3612 <li>MUST be able to report events up to a frequency of at least 10 Hz and SHOULD 3613report events up to at least 50 Hz.</li> 3614 <li>MUST comply with the Android sensor coordinate system as detailed in the 3615Android APIs [<a href="http://developer.android.com/reference/android/hardware/SensorEvent.html">Resources, 90</a>].</li> 3616 <li>MUST be capable of measuring between -900 µT and +900 µT on each axis before 3617saturating.</li> 3618 <li>MUST have a hard iron offset value less than 700 µT and SHOULD have a value 3619below 200 µT, by placing the magnetometer far from dynamic (current-induced) 3620and static (magnet-induced) magnetic fields.</li> 3621 <li>MUST have a resolution equal or denser than 0.6 µT and SHOULD have a resolution 3622equal or denser than 0.2 µ.</li> 3623 <li>SHOULD be temperature compensated.</li> 3624 <li>MUST support online calibration and compensation of the hard iron bias, and 3625preserve the compensation parameters between device reboots.</li> 3626 <li>MUST have the soft iron compensation applied—the calibration can be done either 3627while in use or during the production of the device.</li> 3628 <li>SHOULD have a standard deviation, calculated on a per axis basis on samples 3629collected over a period of at least 3 seconds at the fastest sampling rate, no 3630greater than 0.5 µT.</li> 3631 <li>MUST implement a TYPE_ROTATION_VECTOR composite sensor, if an accelerometer 3632sensor and a gyroscope sensor is also included.</li> 3633 <li>MAY implement the TYPE_GEOMAGNETIC_ROTATION_VECTOR sensor if an accelerometer 3634sensor is also implemented. However if implemented, it MUST consume less than 363510 mW and SHOULD consume less than 3 mW when the sensor is registered for batch 3636mode at 10 Hz.</li> 3637</ul> 3638 3639<h3 id="7_3_3_gps">7.3.3. GPS</h3> 3640 3641 3642<p>Device implementations SHOULD include a GPS receiver. If a device 3643implementation does include a GPS receiver, it SHOULD include some form of“assisted GPS” technique to minimize GPS lock-on time.</p> 3644 3645<h3 id="7_3_4_gyroscope">7.3.4. Gyroscope</h3> 3646 3647 3648<p>Device implementations SHOULD include a gyroscope (angular change sensor). 3649Devices SHOULD NOT include a gyroscope sensor unless a 3-axis accelerometer is 3650also included. If a device implementation includes a gyroscope, it:</p> 3651 3652<ul> 3653 <li>MUST implement the TYPE_GYROSCOPE sensor and SHOULD also implement 3654TYPE_GYROSCOPE_UNCALIBRATED sensor. Existing and new Android devices are 3655STRONGLY RECOMMENDED to implement the SENSOR_TYPE_GYROSCOPE_UNCALIBRATED sensor.</li> 3656 <li>MUST be capable of measuring orientation changes up to 1,000 degrees per second.</li> 3657 <li>MUST be able to report events up to a frequency of at least 50 Hz for 3658 Android Watch devices as such devices have a stricter power constraint and 3659 100 Hz for all other device types.</li> 3660 <li>SHOULD report events up to at least 200 Hz.</li> 3661 <li>MUST have a resolution of 12-bits or more and SHOULD have a resolution of 366216-bits or more.</li> 3663 <li>MUST be temperature compensated.</li> 3664 <li>MUST be calibrated and compensated while in use, and preserve the compensation 3665parameters between device reboots.</li> 3666 <li>MUST have a variance no greater than 1e-7 rad^2 / s^2 per Hz (variance per Hz, 3667or rad^2 / s). The variance is allowed to vary with the sampling rate, but must 3668be constrained by this value. In other words, if you measure the variance of 3669the gyro at 1 Hz sampling rate it should be no greater than 1e-7 rad^2/s^2.</li> 3670 <li>MUST implement a TYPE_ROTATION_VECTOR composite sensor, if an accelerometer 3671sensor and a magnetometer sensor is also included.</li> 3672 <li>If an accelerometer sensor is included, MUST implement the TYPE_GRAVITY and 3673TYPE_LINEAR_ACCELERATION composite sensors and SHOULD implement the 3674TYPE_GAME_ROTATION_VECTOR composite sensor. Existing and new Android devices 3675are STRONGLY RECOMMENDED to implement the TYPE_GAME_ROTATION_VECTOR sensor.</li> 3676</ul> 3677 3678<h3 id="7_3_5_barometer">7.3.5. Barometer</h3> 3679 3680 3681<p>Device implementations SHOULD include a barometer (ambient air pressure 3682sensor). If a device implementation includes a barometer, it:</p> 3683 3684<ul> 3685 <li>MUST implement and report TYPE_PRESSURE sensor.</li> 3686 <li>MUST be able to deliver events at 5 Hz or greater.</li> 3687 <li>MUST have adequate precision to enable estimating altitude.</li> 3688 <li>MUST be temperature compensated.</li> 3689</ul> 3690 3691<h3 id="7_3_6_thermometer">7.3.6. Thermometer</h3> 3692 3693 3694<p>Device implementations MAY include an ambient thermometer (temperature sensor). 3695If present, it MUST be defined as SENSOR_TYPE_AMBIENT_TEMPERATURE and it MUST 3696measure the ambient (room) temperature in degrees Celsius.</p> 3697 3698<p>Device implementations MAY but SHOULD NOT include a CPU temperature sensor. If 3699present, it MUST be defined as SENSOR_TYPE_TEMPERATURE, it MUST measure the 3700temperature of the device CPU, and it MUST NOT measure any other temperature. 3701Note the SENSOR_TYPE_TEMPERATURE sensor type was deprecated in Android 4.0.</p> 3702 3703<h3 id="7_3_7_photometer">7.3.7. Photometer</h3> 3704 3705 3706<p>Device implementations MAY include a photometer (ambient light sensor).</p> 3707 3708<h3 id="7_3_8_proximity_sensor">7.3.8. Proximity Sensor</h3> 3709 3710 3711<p>Device implementations MAY include a proximity sensor. Devices that can make a 3712voice call and indicate any value other than PHONE_TYPE_NONE in getPhoneType 3713SHOULD include a proximity sensor. If a device implementation does include a 3714proximity sensor, it:</p> 3715 3716<ul> 3717 <li>MUST measure the proximity of an object in the same direction as the screen. 3718That is, the proximity sensor MUST be oriented to detect objects close to the 3719screen, as the primary intent of this sensor type is to detect a phone in use 3720by the user. If a device implementation includes a proximity sensor with any 3721other orientation, it MUST NOT be accessible through this API.</li> 3722 <li>MUST have 1-bit of accuracy or more.</li> 3723</ul> 3724 3725 3726<h3 id="7_3_9_hifi_sensors">7.3.9. High Fidelity Sensors</h3> 3727 3728<p>Device implementations supporting a set of higher quality sensors that can meet all 3729the requirements listed in this section MUST identify the support through the 3730<code>android.hardware.sensor.hifi_sensors</code> feature flag.</p> 3731 3732<p>A device declaring android.hardware.sensor.hifi_sensors MUST support all of the following 3733sensor types meeting the quality requirements as below:</p> 3734 3735<ul> 3736 <li>SENSOR_TYPE_ACCELEROMETER 3737 <ul> 3738 <li>MUST have a measurement range between at least -8g and +8g</li> 3739 <li>MUST have a measurement resolution of at least 1024 LSB/G</li> 3740 <li>MUST have a minimum measurement frequency of 12.5 Hz or lower</li> 3741 <li>MUST have a maxmium measurement frequency of 200 Hz or higher</li> 3742 <li>MUST have a measurement noise not above 400uG/√Hz</li> 3743 <li>MUST implement a non-wake-up form of this sensor with a buffering capability of at least 3000 sensor events</li> 3744 <li>MUST have a batching power consumption not worse than 3 mW</li> 3745 </ul> 3746 </li> 3747 <li>SENSOR_TYPE_GYROSCOPE 3748 <ul> 3749 <li>MUST have a measurement range between at least -1000 and +1000 dps</li> 3750 <li>MUST have a measurement resolution of at least 16 LSB/dps</li> 3751 <li>MUST have a minimum measurement frequency of 12.5 Hz or lower</li> 3752 <li>MUST have a maxmium measurement frequency of 200 Hz or higher</li> 3753 <li>MUST have a measurement noise not above 0.014°/s/√Hz</li> 3754 </ul> 3755 </li> 3756 <li>SENSOR_TYPE_GYROSCOPE_UNCALIBRATED with the same quality requirements as 3757 SENSOR_TYPE_GYROSCOPE</li> 3758 <li>SENSOR_TYPE_GEOMAGNETIC_FIELD 3759 <ul> 3760 <li>MUST have a measurement range between at least -900 and +900 uT</li> 3761 <li>MUST have a measurement resolution of at least 5 LSB/uT</li> 3762 <li>MUST have a minimum measurement frequency of 5 Hz or lower</li> 3763 <li>MUST have a maxmium measurement frequency of 50 Hz or higher</li> 3764 <li>MUST have a measurement noise not above 0.5 uT</li> 3765 </ul> 3766 </li> 3767 <li>SENSOR_TYPE_MAGNETIC_FIELD_UNCALIBRATED with the same quality requirements as 3768 SENSOR_TYPE_GEOMAGNETIC_FIELD and in addition: 3769 <ul> 3770 <li>MUST implement a non-wake-up form of this sensor with a buffering capability of at least 600 sensor events</li> 3771 </ul> 3772 </li> 3773 <li>SENSOR_TYPE_PRESSURE 3774 <ul> 3775 <li>MUST have a measurement range between at least 300 and 1100 hPa</li> 3776 <li>MUST have a measurement resolution of at least 80 LSB/hPa</li> 3777 <li>MUST have a minimum measurement frequency of 1 Hz or lower</li> 3778 <li>MUST have a maximum measurement frequency of 10 Hz or higher</li> 3779 <li>MUST have a measurement noise not above 2 Pa/√Hz</li> 3780 <li>MUST implement a non-wake-up form of this sensor with a buffering capability of at least 300 sensor events</li> 3781 <li>MUST have a batching power consumption not worse than 2 mW</li> 3782 </ul> 3783 </li> 3784 <li>SENSOR_TYPE_ROTATION_VECTOR 3785 <ul> 3786 <li>MUST have a batching power consumption not worse than 4 mW</li> 3787 </ul> 3788 </li> 3789 <li>SENSOR_TYPE_GAME_ROTATION_VECTOR MUST implement a non-wake-up form of this sensor with a buffering capability of at least 300 sensor events</li> 3790 <li>SENSOR_TYPE_SIGNIFICANT_MOTION 3791 <ul> 3792 <li>MUST have a power consumption not worse than 0.5 mW when device is static 3793 and 1.5 mW when device is moving</li> 3794 </ul> 3795 </li> 3796 <li>SENSOR_TYPE_STEP_DETECTOR 3797 <ul> 3798 <li>MUST implement a non-wake-up form of this sensor with a buffering capability of at least 100 sensor events</li> 3799 <li>MUST have a power consumption not worse than 0.5 mW when device is static 3800 and 1.5 mW when device is moving</li> 3801 <li>MUST have a batching power consumption not worse than 4 mW</li> 3802 </ul> 3803 </li> 3804 <li>SENSOR_TYPE_STEP_COUNTER 3805 <ul> 3806 <li>MUST have a power consumption not worse than 0.5 mW when device is static 3807 and 1.5 mW when device is moving</li> 3808 </ul> 3809 </li> 3810 <li>SENSOR_TILT_DETECTOR 3811 <ul> 3812 <li>MUST have a power consumption not worse than 0.5 mW when device is static 3813 and 1.5 mW when device is moving</li> 3814 </ul> 3815 </li> 3816</ul> 3817 3818<p>Also such a device MUST meet the following sensor subsystem requirements:</p> 3819 3820<ul> 3821 <li>The event timestamp of the same physical event reported by the Accelerometer, Gyroscope 3822 sensor and Magnetometer MUST be within 2.5 milliseconds of each other.</li> 3823 <li>The Gyroscope sensor event timestamps MUST be on the same time base as the camera 3824 subsystem and within 1 millisconds of error.</li> 3825 <li>The latency of delivery of samples to the HAL SHOULD be below 5 milliseconds from 3826 the instant the data is available on the physical sensor hardware.</li> 3827 <li>The power consumption MUST not be higher than 0.5 mW when device is static and 2.0 mW 3828 when device is moving when any combination of the following sensors are enabled: 3829 <ul> 3830 <li>SENSOR_TYPE_SIGNIFICANT_MOTION</li> 3831 <li>SENSOR_TYPE_STEP_DETECTOR</li> 3832 <li>SENSOR_TYPE_STEP_COUNTER</li> 3833 <li>SENSOR_TILT_DETECTORS</li> 3834 </ul> 3835 </li> 3836</ul> 3837 3838<p>Note that all power consumption requirements in this section do not include the power 3839 consumption of the Application Processor. It is inclusive of the power drawn by the entire 3840 sensor chain - the sensor, any supporting circuitry, any dedicated sensor processing system, 3841 etc.</p> 3842 3843<p>The following sensor types MAY also be supported on a device implementation declaring 3844 android.hardware.sensor.hifi_sensors, but if these sensor types are present they MUST meet the 3845 following minimum buffering capability requirement:</p> 3846 3847<ul> 3848 <li>SENSOR_TYPE_PROXIMITY: 100 sensor events</li> 3849</ul> 3850 3851<h3 id="7_3_10_fingeprint">7.3.10. Fingerprint Sensor</h3> 3852 3853<p>Device implementations with a secure lock screen SHOULD include a fingerprint sensor. 3854If a device implementation includes a fingerprint sensor and has a corresponding API for 3855third-party developers, it:</p> 3856 3857<ul> 3858 <li>MUST declare support for the android.hardware.fingerprint feature.</li> 3859 <li>MUST fully implement the corresponding API as described in the Android SDK documentation 3860[<a href="https://developer.android.com/reference/android/hardware/fingerprint/package-summary.html">Resources, 95</a>]. 3861 </li> 3862 <li>MUST have a false acceptance rate not higher than 0.002%.</li> 3863 <li>Is STRONGLY RECOMMENDED to have a false rejection rate of less than 10%, as measured 3864 on the device</li> 3865 <li>Is STRONGLY RECOMMENDED to have a latency below 1 second, measured from when the fingerprint 3866sensor is touched until the screen is unlocked, for one enrolled finger.</li> 3867 <li>MUST rate limit attempts for at least 30 seconds after five false trials for fingerprint 3868 verification.</li> 3869 <li>MUST have a hardware-backed keystore implementation, and perform the fingerprint matching 3870 in a Trusted Execution Environment (TEE) or on a chip with a secure channel to the TEE. 3871 </li> 3872 <li>MUST have all identifiable fingerprint data encrypted and cryptographically 3873 authenticated such that they cannot be acquired, read or altered outside of the 3874 Trusted Execution Environment (TEE) as documented in the implementation guidelines 3875 on the Android Open Source Project site 3876 [<a href="https://source.android.com/devices/tech/security/authentication/fingerprint-hal.html">Resources, 96</a>]. 3877 </li> 3878 <li>MUST prevent adding a fingerprint without first establishing a chain of trust by 3879 having the user confirm existing or add a new device credential (PIN/pattern/password) 3880 using the TEE as implemented in the Android Open Source project.</li> 3881 <li>MUST NOT enable 3rd-party applications to distinguish between individual fingerprints. 3882 </li> 3883 <li>MUST honor the DevicePolicyManager.KEYGUARD_DISABLE_FINGERPRINT flag.</li> 3884 <li>MUST, when upgraded from a version earlier than Android 6.0, have the fingerprint 3885 data securely migrated to meet the above requirements or removed.</li> 3886 <li>SHOULD use the Android Fingerprint icon provided in the Android Open Source Project.</li> 3887</ul> 3888 3889<h2 id="7_4_data_connectivity">7.4. Data Connectivity</h2> 3890 3891 3892<h3 id="7_4_1_telephony">7.4.1. Telephony</h3> 3893 3894 3895<p>“Telephony” as used by the Android APIs and this document refers specifically 3896to hardware related to placing voice calls and sending SMS messages via a GSM 3897or CDMA network. While these voice calls may or may not be packet-switched, 3898they are for the purposes of Android considered independent of any data 3899connectivity that may be implemented using the same network. In other words, 3900the Android “telephony” functionality and APIs refer specifically to voice 3901calls and SMS. For instance, device implementations that cannot place calls or 3902send/receive SMS messages MUST NOT report the android.hardware.telephony 3903feature or any subfeatures, regardless of whether they use a cellular network 3904for data connectivity.</p> 3905 3906<p>Android MAY be used on devices that do not include telephony hardware. That is, 3907Android is compatible with devices that are not phones. However, if a device 3908implementation does include GSM or CDMA telephony, it MUST implement full 3909support for the API for that technology. Device implementations that do not 3910include telephony hardware MUST implement the full APIs as no-ops.</p> 3911 3912<h3 id="7_4_2_ieee_802_11_wi-fi">7.4.2. IEEE 802.11 (Wi-Fi)</h3> 3913 3914<div class="note"> 3915<p>Android Television device implementations MUST include Wi-Fi support.</p> 3916</div> 3917 3918 3919<p>Android Television device implementations MUST include support for one or more 3920forms of 802.11 (b/g/a/n, etc.) and other types of Android device 3921implementation SHOULD include support for one or more forms of 802.11. If a 3922device implementation does include support for 802.11 and exposes the 3923functionality to a third-party application, it MUST implement the corresponding 3924Android API and:</p> 3925 3926<ul> 3927 <li>MUST report the hardware feature flag android.hardware.wifi.</li> 3928 <li>MUST implement the multicast API as described in the SDK documentation [<a href="http://developer.android.com/reference/android/net/wifi/WifiManager.MulticastLock.html">Resources, 97</a>].</li> 3929 <li>MUST support multicast DNS (mDNS) and MUST NOT filter mDNS packets 3930(224.0.0.251) at any time of operation including: 3931 <ul> 3932 <li>Even when the screen is not in an active state.</li> 3933 <li>For Android Television device implementations, even when in standby power states.</li> 3934 </ul> 3935</ul> 3936 3937<h4 id="7_4_2_1_wi-fi_direct">7.4.2.1. Wi-Fi Direct</h4> 3938 3939 3940<p>Device implementations SHOULD include support for Wi-Fi Direct (Wi-Fi 3941peer-to-peer). If a device implementation does include support for Wi-Fi 3942Direct, it MUST implement the corresponding Android API as described in the SDK 3943documentation [<a href="http://developer.android.com/reference/android/net/wifi/p2p/WifiP2pManager.html">Resources, 98</a>]. If a device implementation includes support for Wi-Fi Direct, then it:</p> 3944 3945<ul> 3946 <li>MUST report the hardware feature android.hardware.wifi.direct.</li> 3947 <li>MUST support regular Wi-Fi operation.</li> 3948 <li>SHOULD support concurrent Wi-Fi and Wi-Fi Direct operation.</li> 3949</ul> 3950 3951<h4 id="7_4_2_2_wi-fi_tunneled_direct_link_setup">7.4.2.2. Wi-Fi Tunneled Direct Link Setup</h4> 3952 3953<div class="note"> 3954<p>Android Television device implementations MUST include support for Wi-Fi 3955Tunneled Direct Link Setup (TDLS).</p> 3956</div> 3957 3958 3959<p>Android Television device implementations MUST include support for Wi-Fi 3960Tunneled Direct Link Setup (TDLS) and other types of Android device 3961implementations SHOULD include support for Wi-Fi TDLS as described in the 3962Android SDK Documentation [<a href="http://developer.android.com/reference/android/net/wifi/WifiManager.html">Resources, 99</a>]. If a device implementation does include support for TDLS and TDLS is enabled 3963by the WiFiManager API, the device:</p> 3964 3965<ul> 3966 <li>SHOULD use TDLS only when it is possible AND beneficial.</li> 3967 <li>SHOULD have some heuristic and NOT use TDLS when its performance might be worse 3968than going through the Wi-Fi access point.</li> 3969</ul> 3970 3971<h3 id="7_4_3_bluetooth">7.4.3. Bluetooth</h3> 3972 3973<div class="note"> 3974<p>Android Watch and Automotive implementations MUST support Bluetooth. Android 3975Television implementations MUST support Bluetooth and Bluetooth LE.</p> 3976</div> 3977 3978 3979<p>Android includes support for Bluetooth and Bluetooth Low Energy [<a href="http://developer.android.com/reference/android/bluetooth/package-summary.html">Resources, 100</a>]. Device implementations that include support for Bluetooth and Bluetooth Low 3980Energy MUST declare the relevant platform features (android.hardware.bluetooth 3981and android.hardware.bluetooth_le respectively) and implement the platform 3982APIs. Device implementations SHOULD implement relevant Bluetooth profiles such 3983as A2DP, AVCP, OBEX, etc. as appropriate for the device. Android Television 3984device implementations MUST support Bluetooth and Bluetooth LE. </p> 3985 3986<p>Device implementations including support for Bluetooth Low Energy:</p> 3987 3988<ul> 3989 <li>MUST declare the hardware feature android.hardware.bluetooth_le.</li> 3990 <li>MUST enable the GATT (generic attribute profile) based Bluetooth APIs as 3991described in the SDK documentation and [<a href="http://developer.android.com/reference/android/bluetooth/package-summary.html">Resources, 100</a>].</li> 3992 <li>are STRONGLY RECOMMMENDED to implement a Resolvable Private Address (RPA) 3993timeout no longer than 15 minutes and rotate the address at timeout to protect 3994user privacy.</li> 3995 <li>SHOULD support offloading of the filtering logic to the bluetooth chipset when 3996implementing the ScanFilter API [<a href="https://developer.android.com/reference/android/bluetooth/le/ScanFilter.html">Resources, 101</a>], and MUST report the correct value of where the filtering logic is implemented whenever queried via the 3997android.bluetooth.BluetoothAdapter.isOffloadedFilteringSupported() method.</li> 3998 <li>SHOULD support offloading of the batched scanning to the bluetooth chipset, but 3999if not supported, MUST report ‘false’ whenever queried via the 4000android.bluetooth.BluetoothAdapater.isOffloadedScanBatchingSupported() method.</li> 4001 <li>SHOULD support multi advertisement with at least 4 slots, but if not supported, 4002MUST report ‘false’ whenever queried via the 4003android.bluetooth.BluetoothAdapter.isMultipleAdvertisementSupported() method.</li> 4004</ul> 4005 4006<h3 id="7_4_4_near-field_communications">7.4.4. Near-Field Communications</h3> 4007 4008 4009<p>Device implementations SHOULD include a transceiver and related hardware for 4010Near-Field Communications (NFC). If a device implementation does include NFC 4011hardware and plans to make it available to third-party apps, then it:</p> 4012 4013<ul> 4014 <li>MUST report the android.hardware.nfc feature from the 4015android.content.pm.PackageManager.hasSystemFeature() method [<a href="http://developer.android.com/reference/android/content/pm/PackageManager.html">Resources, 70</a>].</li> 4016 <li>MUST be capable of reading and writing NDEF messages via the following NFC 4017standards: 4018 <ul> 4019 <li>MUST be capable of acting as an NFC Forum reader/writer (as defined by the NFC 4020Forum technical specification NFCForum-TS-DigitalProtocol-1.0) via the 4021following NFC standards: 4022 <ul> 4023 <li>NfcA (ISO14443-3A)</li> 4024 <li>NfcB (ISO14443-3B)</li> 4025 <li>NfcF (JIS X 6319-4)</li> 4026 <li>IsoDep (ISO 14443-4)</li> 4027 <li>NFC Forum Tag Types 1, 2, 3, 4 (defined by the NFC Forum)</li> 4028 </ul> 4029 <li>STRONGLY RECOMMENDED to be capable of reading and writing NDEF messages as well 4030 as raw data via the following NFC standards. Note that while the NFC standards 4031 below are stated as STRONGLY RECOMMENDED, the Compatibility Definition for a 4032 future version is planned to change these to MUST. These standards are optional 4033 in this version but will be required in future versions. Existing and new devices 4034 that run this version of Android are very strongly encouraged to meet these 4035 requirements now so they will be able to upgrade to the future platform releases. 4036 <ul> 4037 <li>NfcV (ISO 15693)</li> 4038 </ul></li> 4039 <li>SHOULD be capable of reading the barcode and URL (if encoded) of 4040 Thinfilm NFC Barcode 4041 [<a href="http://developer.android.com/reference/android/nfc/tech/NfcBarcode.html">Resources, 102</a>] products. 4042 </li> 4043 <li>MUST be capable of transmitting and receiving data via the following 4044peer-to-peer standards and protocols: 4045 <ul> 4046 <li>ISO 18092</li> 4047 <li>LLCP 1.2 (defined by the NFC Forum)</li> 4048 <li>SDP 1.0 (defined by the NFC Forum)</li> 4049 <li>NDEF Push Protocol [<a href="http://static.googleusercontent.com/media/source.android.com/en/us/compatibility/ndef-push-protocol.pdf">Resources, 103</a>]</li> 4050 <li>SNEP 1.0 (defined by the NFC Forum)</li> 4051 </ul></li> 4052 <li>MUST include support for Android Beam [<a href="http://developer.android.com/guide/topics/connectivity/nfc/nfc.html">Resources, 104</a>]: 4053 <ul> 4054 <li>MUST implement the SNEP default server. Valid NDEF messages received by the 4055default SNEP server MUST be dispatched to applications using the 4056android.nfc.ACTION_NDEF_DISCOVERED intent. Disabling Android Beam in settings 4057MUST NOT disable dispatch of incoming NDEF message.</li> 4058 <li>MUST honor the android.settings.NFCSHARING_SETTINGS intent to show NFC sharing 4059settings [<a href="http://developer.android.com/reference/android/provider/Settings.html#ACTION_NFCSHARING_SETTINGS">Resources, 105</a>].</li> 4060 <li>MUST implement the NPP server. Messages received by the NPP server MUST be 4061processed the same way as the SNEP default server.</li> 4062 <li>MUST implement a SNEP client and attempt to send outbound P2P NDEF to the 4063default SNEP server when Android Beam is enabled. If no default SNEP server is 4064found then the client MUST attempt to send to an NPP server.</li> 4065 <li>MUST allow foreground activities to set the outbound P2P NDEF message using 4066android.nfc.NfcAdapter.setNdefPushMessage, and 4067android.nfc.NfcAdapter.setNdefPushMessageCallback, and 4068android.nfc.NfcAdapter.enableForegroundNdefPush.</li> 4069 <li>SHOULD use a gesture or on-screen confirmation, such as 'Touch to Beam', before 4070sending outbound P2P NDEF messages.</li> 4071 <li>SHOULD enable Android Beam by default and MUST be able to send and receive 4072using Android Beam, even when another proprietary NFC P2p mode is turned on.</li> 4073 <li>MUST support NFC Connection handover to Bluetooth when the device supports 4074Bluetooth Object Push Profile. Device implementations MUST support connection 4075handover to Bluetooth when using android.nfc.NfcAdapter.setBeamPushUris, by 4076implementing the “Connection Handover version 1.2” [<a href="http://members.nfc-forum.org/specs/spec_list/#conn_handover">Resources, 106</a>] and “Bluetooth Secure Simple Pairing Using NFC version 1.0” [<a href="http://members.nfc-forum.org/apps/group_public/download.php/18688/NFCForum-AD-BTSSP_1_1.pdf">Resources, 107</a>] specs from the NFC Forum. Such an implementation MUST implement the handover 4077LLCP service with service name “urn:nfc:sn:handover” for exchanging the 4078handover request/select records over NFC, and it MUST use the Bluetooth Object 4079Push Profile for the actual Bluetooth data transfer. For legacy reasons (to 4080remain compatible with Android 4.1 devices), the implementation SHOULD still 4081accept SNEP GET requests for exchanging the handover request/select records 4082over NFC. However an implementation itself SHOULD NOT send SNEP GET requests 4083for performing connection handover.</li> 4084 </ul></li> 4085 <li>MUST poll for all supported technologies while in NFC discovery mode.</li> 4086 <li>SHOULD be in NFC discovery mode while the device is awake with the screen 4087active and the lock-screen unlocked.</li> 4088</ul> 4089</ul> 4090 4091<p>(Note that publicly available links are not available for the JIS, ISO, and NFC 4092Forum specifications cited above.)</p> 4093 4094<p>Android includes support for NFC Host Card Emulation (HCE) mode. If a 4095device implementation does include an NFC controller chipset capable of HCE and 4096Application ID (AID) routing, then it:</p> 4097 4098<ul> 4099 <li>MUST report the android.hardware.nfc.hce feature constant.</li> 4100 <li>MUST support NFC HCE APIs as defined in the Android SDK [<a href="http://developer.android.com/guide/topics/connectivity/nfc/hce.html">Resources, 108</a>].</li> 4101</ul> 4102 4103<p>Additionally, device implementations MAY include reader/writer support for the 4104following MIFARE technologies.</p> 4105 4106<ul> 4107 <li>MIFARE Classic</li> 4108 <li>MIFARE Ultralight</li> 4109 <li>NDEF on MIFARE Classic</li> 4110</ul> 4111 4112<p>Note that Android includes APIs for these MIFARE types. If a device 4113implementation supports MIFARE in the reader/writer role, it:</p> 4114 4115<ul> 4116 <li>MUST implement the corresponding Android APIs as documented by the Android SDK.</li> 4117 <li>MUST report the feature com.nxp.mifare from the 4118android.content.pm.PackageManager.hasSystemFeature() method [<a href="http://developer.android.com/reference/android/content/pm/PackageManager.html">Resources, 70</a>]. Note that this is not a standard Android feature and as such does not appear 4119as a constant in the android.content.pm.PackageManager class.</li> 4120 <li>MUST NOT implement the corresponding Android APIs nor report the com.nxp.mifare 4121feature unless it also implements general NFC support as described in this 4122section.</li> 4123</ul> 4124 4125<p>If a device implementation does not include NFC hardware, it MUST NOT declare 4126the android.hardware.nfc feature from the 4127android.content.pm.PackageManager.hasSystemFeature() method [<a href="http://developer.android.com/reference/android/content/pm/PackageManager.html">Resources, 70</a>], and MUST implement the Android NFC API as a no-op.</p> 4128 4129<p>As the classes android.nfc.NdefMessage and android.nfc.NdefRecord represent a 4130protocol-independent data representation format, device implementations MUST 4131implement these APIs even if they do not include support for NFC or declare the 4132android.hardware.nfc feature.</p> 4133 4134<h3 id="7_4_5_minimum_network_capability">7.4.5. Minimum Network Capability</h3> 4135 4136 4137<p>Device implementations MUST include support for one or more forms of data 4138networking. Specifically, device implementations MUST include support for at 4139least one data standard capable of 200Kbit/sec or greater. Examples of 4140technologies that satisfy this requirement include EDGE, HSPA, EV-DO, 802.11g, 4141Ethernet, Bluetooth PAN, etc.</p> 4142 4143<p>Device implementations where a physical networking standard (such as Ethernet) 4144is the primary data connection SHOULD also include support for at least one 4145common wireless data standard, such as 802.11 (Wi-Fi).</p> 4146 4147<p>Devices MAY implement more than one form of data connectivity.</p> 4148 4149<p>Devices MUST include an IPv6 networking stack and support IPv6 communication 4150using the managed APIs, such as <code>java.net.Socket</code> and 4151<code>java.net.URLConnection</code>, as well as the native APIs, such as 4152<code>AF_INET6</code> sockets. The required level of IPv6 support depends on 4153the network type, as follows:</p> 4154<ul> 4155 <li>Devices that support Wi-Fi networks MUST support dual-stack and IPv6-only 4156 operation on Wi-Fi.</li> 4157 <li>Devices that support Ethernet networks MUST support dual-stack operation 4158 on Ethernet.</li> 4159 <li>Devices that support cellular data SHOULD support IPv6 operation 4160 (IPv6-only and possibly dual-stack) on cellular data.</li> 4161 <li>When a device is simultaneously connected to more than one network (e.g., 4162 Wi-Fi and cellular data), it MUST simultaneously meet these requirements on 4163 each network to which it is connected.</li> 4164</ul> 4165 4166<p>IPv6 MUST be enabled by default.</p> 4167 4168<p>In order to ensure that IPv6 communication is as reliable as IPv4, unicast 4169IPv6 packets sent to the device MUST NOT be dropped, even when the screen is 4170not in an active state. Redundant multicast IPv6 packets, such as repeated 4171identical Router Advertisements, MAY be rate-limited in hardware or firmware 4172if doing so is necessary to save power. In such cases, rate-limiting MUST NOT 4173cause the device to lose IPv6 connectivity on any IPv6-compliant network that 4174uses RA lifetimes of at least 180 seconds.</p> 4175 4176<p>IPv6 connectivity MUST be maintained in doze mode.</p> 4177 4178<h3 id="7_4_6_sync_settings">7.4.6. Sync Settings</h3> 4179 4180 4181<p>Device implementations MUST have the master auto-sync setting on by default so 4182that the method getMasterSyncAutomatically() returns “true” [<a href="http://developer.android.com/reference/android/content/ContentResolver.html">Resources, 109</a>].</p> 4183 4184<h2 id="7_5_cameras">7.5. Cameras</h2> 4185 4186 4187<p>Device implementations SHOULD include a rear-facing camera and MAY include a 4188front-facing camera. A rear-facing camera is a camera located on the side of 4189the device opposite the display; that is, it images scenes on the far side of 4190the device, like a traditional camera. A front-facing camera is a camera 4191located on the same side of the device as the display; that is, a camera 4192typically used to image the user, such as for video conferencing and similar 4193applications.</p> 4194 4195<p>If a device implementation includes at least one camera, it SHOULD be possible 4196for an application to simultaneously allocate 3 bitmaps equal to the size of 4197the images produced by the largest-resolution camera sensor on the device.</p> 4198 4199<h3 id="7_5_1_rear-facing_camera">7.5.1. Rear-Facing Camera</h3> 4200 4201 4202<p>Device implementations SHOULD include a rear-facing camera. If a device 4203implementation includes at least one rear-facing camera, it:</p> 4204 4205<ul> 4206 <li>MUST report the feature flag android.hardware.camera and 4207android.hardware.camera.any.</li> 4208 <li>MUST have a resolution of at least 2 megapixels.</li> 4209 <li>SHOULD have either hardware auto-focus or software auto-focus implemented in 4210the camera driver (transparent to application software).</li> 4211 <li>MAY have fixed-focus or EDOF (extended depth of field) hardware.</li> 4212 <li>MAY include a flash. If the Camera includes a flash, the flash lamp MUST NOT be 4213lit while an android.hardware.Camera.PreviewCallback instance has been 4214registered on a Camera preview surface, unless the application has explicitly 4215enabled the flash by enabling the FLASH_MODE_AUTO or FLASH_MODE_ON attributes 4216of a Camera.Parameters object. Note that this constraint does not apply to the 4217device’s built-in system camera application, but only to third-party 4218applications using Camera.PreviewCallback.</li> 4219</ul> 4220 4221<h3 id="7_5_2_front-facing_camera">7.5.2. Front-Facing Camera</h3> 4222 4223 4224<p>Device implementations MAY include a front-facing camera. If a device 4225implementation includes at least one front-facing camera, it:</p> 4226 4227<ul> 4228 <li>MUST report the feature flag android.hardware.camera.any and 4229android.hardware.camera.front.</li> 4230 <li>MUST have a resolution of at least VGA (640x480 pixels).</li> 4231 <li>MUST NOT use a front-facing camera as the default for the Camera API. The 4232camera API in Android has specific support for front-facing cameras and device 4233implementations MUST NOT configure the API to to treat a front-facing camera as 4234the default rear-facing camera, even if it is the only camera on the device.</li> 4235 <li>MAY include features (such as auto-focus, flash, etc.) available to rear-facing 4236cameras as described in <a href="#7_5_1_rear-facing_camera">section 7.5.1</a>.</li> 4237 <li>MUST horizontally reflect (i.e. mirror) the stream displayed by an app in a 4238CameraPreview, as follows: 4239 <ul> 4240 <li>If the device implementation is capable of being rotated by user (such as 4241automatically via an accelerometer or manually via user input), the camera 4242preview MUST be mirrored horizontally relative to the device’s current 4243orientation.</li> 4244 <li>If the current application has explicitly requested that the Camera display be 4245rotated via a call to the android.hardware.Camera.setDisplayOrientation()[<a href="http://developer.android.com/reference/android/hardware/Camera.html#setDisplayOrientation(int)">Resources, 110</a>] method, the camera preview MUST be mirrored horizontally relative to the 4246orientation specified by the application.</li> 4247 <li>Otherwise, the preview MUST be mirrored along the device’s default horizontal 4248axis.</li> 4249 </ul></li> 4250 <li>MUST mirror the image displayed by the postview in the same manner as the 4251camera preview image stream. If the device implementation does not support 4252postview, this requirement obviously does not apply.</li> 4253 <li>MUST NOT mirror the final captured still image or video streams returned to 4254application callbacks or committed to media storage.</li> 4255</ul> 4256 4257<h3 id="7_5_3_external_camera">7.5.3. External Camera</h3> 4258 4259 4260<p>Device implementations with USB host mode MAY include support for an external 4261camera that connects to the USB port. If a device includes support for an 4262external camera, it:</p> 4263 4264<ul> 4265 <li>MUST declare the platform feature android.hardware.camera.external and 4266android.hardware camera.any.</li> 4267 <li>MUST support USB Video Class (UVC 1.0 or higher).</li> 4268 <li>MAY support multiple cameras.</li> 4269</ul> 4270 4271<p>Video compression (such as MJPEG) support is RECOMMENDED to enable transfer of 4272high-quality unencoded streams (i.e. raw or independently compressed picture 4273streams). Camera-based video encoding MAY be supported. If so, a simultaneous 4274unencoded/ MJPEG stream (QVGA or greater resolution) MUST be accessible to the 4275device implementation.</p> 4276 4277<h3 id="7_5_4_camera_api_behavior">7.5.4. Camera API Behavior</h3> 4278 4279 4280<p>Android includes two API packages to access the camera, the newer 4281android.hardware.camera2 API expose lower-level camera control to the app, 4282including efficient zero-copy burst/streaming flows and per-frame controls of 4283exposure, gain, white balance gains, color conversion, denoising, sharpening, 4284and more.</p> 4285 4286<p>The older API package, android.hardware.Camera, is marked as deprecated in 4287Android 5.0 but as it should still be available for apps to use Android device 4288implementations MUST ensure the continued support of the API as described in 4289this section and in the Android SDK.</p> 4290 4291<p>Device implementations MUST implement the following behaviors for the 4292camera-related APIs, for all available cameras:</p> 4293 4294<ul> 4295 <li>If an application has never called 4296android.hardware.Camera.Parameters.setPreviewFormat(int), then the device MUST 4297use android.hardware.PixelFormat.YCbCr_420_SP for preview data provided to 4298application callbacks.</li> 4299 <li>If an application registers an android.hardware.Camera.PreviewCallback instance 4300and the system calls the onPreviewFrame() method when the preview format is 4301YCbCr_420_SP, the data in the byte[] passed into onPreviewFrame() must further 4302be in the NV21 encoding format. That is, NV21 MUST be the default.</li> 4303 <li>For android.hardware.Camera, device implementations MUST support the YV12 4304format (as denoted by the android.graphics.ImageFormat.YV12 constant) for 4305camera previews for both front- and rear-facing cameras. (The hardware video 4306encoder and camera may use any native pixel format, but the device 4307implementation MUST support conversion to YV12.)</li> 4308 <li>For android.hardware.camera2, device implementations must support the 4309android.hardware.ImageFormat.YUV_420_888 and android.hardware.ImageFormat.JPEG 4310formats as outputs through the android.media.ImageReader API.</li> 4311</ul> 4312 4313<p>Device implementations MUST still implement the full Camera API included in the 4314Android SDK documentation [<a href="http://developer.android.com/reference/android/hardware/Camera.html">Resources, 111</a>], 4315regardless of whether the device includes hardware autofocus or other 4316capabilities. For instance, cameras that lack autofocus MUST still call any 4317registered android.hardware.Camera.AutoFocusCallback instances (even though 4318this has no relevance to a non-autofocus camera.) Note that this does apply to 4319front-facing cameras; for instance, even though most front-facing cameras do 4320not support autofocus, the API callbacks must still be “faked” as described.</p> 4321 4322<p>Device implementations MUST recognize and honor each parameter name defined as 4323a constant on the android.hardware.Camera.Parameters class, if the underlying 4324hardware supports the feature. If the device hardware does not support a 4325feature, the API must behave as documented. Conversely, device implementations 4326MUST NOT honor or recognize string constants passed to the 4327android.hardware.Camera.setParameters() method other than those documented as 4328constants on the android.hardware.Camera.Parameters. That is, device 4329implementations MUST support all standard Camera parameters if the hardware 4330allows, and MUST NOT support custom Camera parameter types. For instance, 4331device implementations that support image capture using high dynamic range 4332(HDR) imaging techniques MUST support camera parameter Camera.SCENE_MODE_HDR [<a href="http://developer.android.com/reference/android/hardware/Camera.Parameters.html">Resources, 112</a>].</p> 4333 4334<p>Because not all device implementations can fully support all the features of 4335the android.hardware.camera2 API, device implementations MUST report the proper 4336level of support with the android.info.supportedHardwareLevel property as 4337described in the Android SDK [<a href="https://developer.android.com/reference/android/hardware/camera2/CameraCharacteristics.html#INFO_SUPPORTED_HARDWARE_LEVEL">Resources, 113</a>] and report the appropriate framework feature flags [<a href="http://source.android.com/devices/camera/versioning.html">Resources, 114</a>].</p> 4338 4339<p>Device implementations MUST also declare its Individual camera capabilities of 4340android.hardware.camera2 via the android.request.availableCapabilities property 4341and declare the appropriate feature flags [<a href="http://source.android.com/devices/camera/versioning.html">Resources, 114</a>]; a device must define the feature flag if any of its attached camera devices supports the feature.</p> 4342 4343<p>Device implementations MUST broadcast the Camera.ACTION_NEW_PICTURE intent 4344whenever a new picture is taken by the camera and the entry of the picture has 4345been added to the media store.</p> 4346 4347<p>Device implementations MUST broadcast the Camera.ACTION_NEW_VIDEO intent 4348whenever a new video is recorded by the camera and the entry of the picture has 4349been added to the media store.</p> 4350 4351<h3 id="7_5_5_camera_orientation">7.5.5. Camera Orientation</h3> 4352 4353 4354<p>Both front- and rear-facing cameras, if present, MUST be oriented so that the 4355long dimension of the camera aligns with the screen’s long dimension. That is, 4356when the device is held in the landscape orientation, cameras MUST capture 4357images in the landscape orientation. This applies regardless of the device’s 4358natural orientation; that is, it applies to landscape-primary devices as well 4359as portrait-primary devices.</p> 4360 4361<h2 id="7_6_memory_and_storage">7.6. Memory and Storage</h2> 4362 4363 4364<h3 id="7_6_1_minimum_memory_and_storage">7.6.1. Minimum Memory and Storage</h3> 4365 4366<div class="note"> 4367<p>Android Television devices MUST have at least 5GB of non-volatile storage 4368available for application private data.</p> 4369</div> 4370 4371 4372<p>The memory available to the kernel and userspace on device implementations MUST 4373be at least equal or larger than the minimum values specified by the following 4374table. (See <a href="#7_1_1_screen_configuration">section 7.1.1</a> for screen size and density definitions.)</p> 4375<table> 4376 <tr> 4377 <th>Density and screen size</th> 4378 <th>32-bit device</th> 4379 <th>64-bit device</th> 4380 </tr> 4381 <tr> 4382 <td>Android Watch devices (due to smaller screens)</td> 4383 <td>416MB</td> 4384 <td>Not applicable</td> 4385 </tr> 4386 <tr> 4387 <td><ul> 4388 <li class="table_list">280dpi or lower on small/normal screens</li> 4389 <li class="table_list">mdpi or lower on large screens</li> 4390 <li class="table_list">ldpi or lower on extra large screens</li> 4391 </ul></td> 4392 <td>424MB</td> 4393 <td>704MB</td> 4394 </tr> 4395 <tr> 4396 <td><ul> 4397 <li class="table_list">xhdpi or higher on small/normal screens</li> 4398 <li class="table_list">hdpi or higher on large screens</li> 4399 <li class="table_list">mdpi or higher on extra large screens</li></ul></td> 4400 <td>512MB</td> 4401 <td>832MB</td> 4402 </tr> 4403 <tr> 4404 <td><ul> 4405 <li class="table_list">400dpi or higher on small/normal screens</li> 4406 <li class="table_list">xhdpi or higher on large screens</li> 4407 <li class="table_list">tvdpi or higher on extra large screens</li></ul></td> 4408 <td>896MB</td> 4409 <td>1280MB</td> 4410 </tr> 4411 <tr> 4412 <td><ul> 4413 <li class="table_list">560dpi or higher on small/normal screens</li> 4414 <li class="table_list">400dpi or higher on large screens</li> 4415 <li class="table_list">xhdpi or higher on extra large screens</li></ul></td> 4416 <td>1344MB</td> 4417 <td>1824MB</td> 4418 </tr> 4419</table> 4420 4421 4422<p>The minimum memory values MUST be in addition to any memory space already 4423dedicated to hardware components such as radio, video, and so on that is not 4424under the kernel’s control.</p> 4425 4426<p>Device implementations with less than 512MB of memory available to the kernel 4427and userspace, unless an Android Watch, MUST return the value "true" for 4428ActivityManager.isLowRamDevice().</p> 4429 4430<p>Android Television devices MUST have at least 5GB and other device 4431implementations MUST have at least 1.5GB of non-volatile storage available for 4432application private data. That is, the /data partition MUST be at least 5GB for 4433Android Television devices and at least 1.5GB for other device implementations. 4434Device implementations that run Android are <strong>STRONGLY RECOMMENDED</strong> to have at least 3GB of non-volatile storage for application private data so 4435they will be able to upgrade to the future platform releases.</p> 4436 4437<p>The Android APIs include a Download Manager that applications MAY use to 4438download data files [<a href="http://developer.android.com/reference/android/app/DownloadManager.html">Resources, 115</a>]. The device implementation of the Download Manager MUST be capable of 4439downloading individual files of at least 100MB in size to the default “cache" 4440location.</p> 4441 4442<h3 id="7_6_2_application_shared_storage">7.6.2. Application Shared Storage</h3> 4443 4444 4445<p>Device implementations MUST offer shared storage for applications also often 4446referred as “shared external storage”. </p> 4447 4448<p>Device implementations MUST be configured with shared storage mounted by 4449default, “out of the box”. If the shared storage is not mounted on the Linux 4450path /sdcard, then the device MUST include a Linux symbolic link from /sdcard 4451to the actual mount point.</p> 4452 4453<p>Device implementations MAY have hardware for user-accessible removable storage, 4454such as a Secure Digital (SD) card slot. If this slot is used to satisfy the 4455shared storage requirement, the device implementation:</p> 4456 4457<ul> 4458 <li>MUST implement a toast or pop-up user interface warning the user when there is 4459no SD card.</li> 4460 <li>MUST include a FAT-formatted SD card 1GB in size or larger OR show on the box 4461and other material available at time of purchase that the SD card has to be 4462separately purchased.</li> 4463 <li>MUST mount the SD card by default.</li> 4464</ul> 4465 4466<p>Alternatively, device implementations MAY allocate internal (non-removable) 4467storage as shared storage for apps as included in the upstream Android Open 4468Source Project; device implementations SHOULD use this configuration and 4469software implementation. If a device implementation uses internal 4470(non-removable) storage to satisfy the shared storage requirement, while that 4471storage MAY share space with the application private data, it MUST be at least 44721GB in size and mounted on /sdcard (or /sdcard MUST be a 4473symbolic link to the physical location if it is mounted elsewhere).</p> 4474 4475<p>Device implementations MUST enforce as documented the 4476android.permission.WRITE_EXTERNAL_STORAGE permission on this shared storage. 4477Shared storage MUST otherwise be writable by any application that obtains that 4478permission.</p> 4479 4480<p>Device implementations that include multiple shared storage paths (such as both 4481an SD card slot and shared internal storage) MUST allow only pre-installed & 4482privileged Android applications with the WRITE_EXTERNAL_STORAGE permission to 4483write to the secondary external storage, except when writing to their 4484package-specific directories or within the <code>URI</code> returned by firing 4485the <code>ACTION_OPEN_DOCUMENT_TREE</code> intent.</p> 4486 4487<p>However, device implementations SHOULD expose content from 4488both storage paths transparently through Android’s media scanner service 4489and android.provider.MediaStore.</p> 4490 4491<p>Regardless of the form of shared storage used, if the device implementation 4492has a USB port with USB peripheral mode support, it MUST provide some mechanism 4493to access the contents of shared storage from a host computer. Device 4494implementations MAY use USB mass storage, but SHOULD use Media Transfer Protocol 4495to satisfy this requirement. If the device implementation supports Media 4496Transfer Protocol, it:</p> 4497 4498<ul> 4499 <li>SHOULD be compatible with the reference Android MTP host, Android File Transfer 4500[<a href="http://www.android.com/filetransfer">Resources, 116</a>].</li> 4501 <li>SHOULD report a USB device class of 0x00.</li> 4502 <li>SHOULD report a USB interface name of 'MTP'.</li> 4503</ul> 4504 4505<h3 id="7_6_3_adoptable_storage">7.6.3. Adoptable Storage</h3> 4506 4507<p>Device implementations are STRONGLY RECOMMENDED to implement adoptable 4508storage if the removable storage device port is in a long-term stable location, 4509such as within the battery compartment or other protective cover 4510[<a 4511href="http://source.android.com/devices/storage/adoptable.html">Resources, 4512117</a>].</p> 4513 4514<p>Device implementations such as a television, MAY enable adoption through USB 4515ports as the device is expected to be static and not mobile. But for other 4516device implementations that are mobile in nature, it is STRONGLY RECOMMENDED to 4517implement the adoptable storage in a long-term stable location, since accidentally 4518disconnecting them can cause data loss/corruption.</p> 4519 4520<h2 id="7_7_usb">7.7. USB</h2> 4521 4522 4523<p>Device implementations SHOULD support USB peripheral mode and SHOULD support 4524USB host mode.</p> 4525 4526<p>If a device implementation includes a USB port supporting peripheral mode:</p> 4527 4528<ul> 4529 <li>The port MUST be connectable to a USB host that has a standard type-A or type 4530-C USB port.</li> 4531 <li>The port SHOULD use micro-B, micro-AB or Type-C USB form factor. Existing and 4532new Android devices are <strong>STRONGLY RECOMMENDED to meet these requirements</strong> 4533so they will be able to upgrade to future platform releases.</li> 4534 <li>The port SHOULD either be located on the bottom of the device (according to natural 4535orientation) or enable software screen rotation for all apps (including home 4536screen), so that the display draws correctly when the device is oriented with 4537the port at bottom. Existing and new Android devices are <strong>STRONGLY RECOMMENDED 4538to meet these requirements</strong> so they will be able to upgrade to future platform 4539releases.</li> 4540 <li>It SHOULD implement the Android Open Accessory (AOA) API and specification as 4541documented in the Android SDK documentation, and if it is an Android Handheld 4542device it MUST implement the AOA API. Device implementations implementing the 4543AOA specification: 4544 <ul> 4545 <li>MUST declare support for the hardware feature android.hardware.usb.accessory [<a href="http://developer.android.com/guide/topics/connectivity/usb/accessory.html">Resources, 118</a>].</li> 4546 <li>MUST support establishing an 4547<a href="http://source.android.com/devices/accessories/aoa.html">AOA protocol based communication</a> 4548on first time connection with a USB host machine that acts as an accessory, without the need for the 4549user to change the default USB mode.</li> 4550 <li>MUST implement the USB audio class as documented in the Android SDK 4551documentation [<a href="http://developer.android.com/reference/android/hardware/usb/UsbConstants.html#USB_CLASS_AUDIO">Resources, 119</a>].</li> 4552 <li>And also the USB mass storage class, MUST include the string "android" 4553at the end of the interface description <code>iInterface</code> string of the 4554USB mass storage</li> 4555 </ul> 4556 </li> 4557 <li>It SHOULD implement support to draw 1.5 A current during HS chirp and traffic 4558as specified in the USB Battery Charging Specification, Revision 1.2 [<a href="http://www.usb.org/developers/docs/devclass_docs/BCv1.2_070312.zip">Resources, 120</a>]. Existing and new Android devices are <strong>STRONGLY RECOMMENDED to meet these requirements</strong> so they will be able to upgrade to the future platform releases.</li> 4559the Type-C resistor standard.</li> 4560 <li>The value of iSerialNumber in USB standard device descriptor MUST be equal to 4561the value of android.os.Build.SERIAL.</li> 4562</ul> 4563 4564<p>If a device implementation includes a USB port supporting host mode, it:</p> 4565 4566<ul> 4567 <li>SHOULD use a type-C USB port, if the device implementation supports USB 3.1.</li> 4568 <li>MAY use a non-standard port form factor, but if so MUST ship with a cable or 4569cables adapting the port to a standard type-A or type-C USB port.</li> 4570 <li>MAY use a micro-AB USB port, but if so SHOULD ship with a cable or cables 4571adapting the port to a standard type-A or type-C USB port.</li> 4572 <li>is <strong>STRONGLY RECOMMENDED</strong> to implement the USB audio class as documented in the Android SDK 4573documentation [<a href="http://developer.android.com/reference/android/hardware/usb/UsbConstants.html#USB_CLASS_AUDIO">Resources, 119</a>].</li> 4574 <li>MUST implement the Android USB host API as documented in the Android SDK, and 4575MUST declare support for the hardware feature android.hardware.usb.host [<a href="http://developer.android.com/guide/topics/connectivity/usb/host.html">Resources, 121</a>].</li> 4576 <li>SHOULD support the Charging Downstream Port output current range of 1.5 A ~ 5 A 4577as specified in the USB Battery Charging Specification, Revision 1.2 [<a href="http://www.usb.org/developers/docs/devclass_docs/BCv1.2_070312.zip">Resources, 120</a>].</li> 4578</ul> 4579 4580<h2 id="7_8_audio">7.8. Audio</h2> 4581 4582 4583<h3 id="7_8_1_microphone">7.8.1. Microphone</h3> 4584 4585<div class="note"> 4586<p>Android Handheld, Watch, and Automotive implementations MUST include a 4587microphone.</p> 4588</div> 4589 4590 4591<p>Device implementations MAY omit a microphone. However, if a device 4592implementation omits a microphone, it MUST NOT report the 4593android.hardware.microphone feature constant, and MUST implement the audio 4594recording API at least as no-ops, per <a href="#7_hardware_compatibility">section 7</a>. 4595Conversely, device implementations that do possess a microphone:</p> 4596 4597<ul> 4598 <li>MUST report the android.hardware.microphone feature constant</li> 4599 <li>MUST meet the audio recording requirements in <a href="#5_4_audio_recording">section 5.4</a></li> 4600 <li>MUST meet the audio latency requirements in <a href="#5_6_audio_latency">section 5.6</a></li> 4601 <li>STRONGLY RECOMMENDED to support near-ultrasound recording as described in 4602 <a href="#7_8_3_near_ultrasound">section 7.8.3</a></li> 4603</ul> 4604 4605<h3 id="7_8_2_audio_output">7.8.2. Audio Output</h3> 4606 4607<div class="note"> 4608<p>Android Watch devices MAY include an audio output.</p> 4609</div> 4610 4611<p>Device implementations including a speaker or with an audio/multimedia output 4612port for an audio output peripheral as a headset or an external speaker:</p> 4613 4614<ul> 4615 <li>MUST report the android.hardware.audio.output feature constant.</li> 4616 <li>MUST meet the audio playback requirements in <a href="#5_5_audio_playback">section 5.5</a>.</li> 4617 <li>MUST meet the audio latency requirements in <a href="#5_6_audio_latency">section 5.6</a>.</li> 4618 <li>STRONGLY RECOMMENDED to support near-ultrasound playback as described in 4619 <a href="#7_8_3_near_ultrasound">section 7.8.3</a></li> 4620</ul> 4621 4622<p>Conversely, if a device implementation does not include a speaker or audio 4623output port, it MUST NOT report the android.hardware.audio output feature, and 4624MUST implement the Audio Output related APIs as no-ops at least. </p> 4625 4626<p>Android Watch device implementation MAY but SHOULD NOT have audio output, but 4627other types of Android device implementations MUST have an audio output and 4628declare android.hardware.audio.output.</p> 4629 4630<h4 id="7_8_2_1_analog_audio_ports">7.8.2.1. Analog Audio Ports</h4> 4631 4632 4633<p>In order to be compatible with the headsets and other audio accessories using 4634the 3.5mm audio plug across the Android ecosystem [<a href="http://source.android.com/accessories/headset-spec.html">Resources, 122</a>], if a device implementation includes one or more analog audio ports, at least 4635one of the audio port(s) SHOULD be a 4 conductor 3.5mm audio jack. If a device 4636implementation has a 4 conductor 3.5mm audio jack, it:</p> 4637 4638<ul> 4639 <li>MUST support audio playback to stereo headphones and stereo headsets with a 4640microphone, and SHOULD support audio recording from stereo headsets with a 4641microphone.</li> 4642 <li>MUST support TRRS audio plugs with the CTIA pin-out order, and SHOULD support 4643audio plugs with the OMTP pin-out order.</li> 4644 <li>MUST support the detection of microphone on the plugged in audio accessory, if 4645the device implementation supports a microphone, and broadcast the 4646android.intent.action.HEADSET_PLUG with the extra value microphone set as 1.</li> 4647 <li>SHOULD support the detection and mapping to the keycodes for the following 3 4648ranges of equivalent impedance between the microphone and ground conductors on 4649the audio plug: 4650 <ul> 4651 <li><strong>70 ohm or less</strong>: KEYCODE_HEADSETHOOK</li> 4652 <li><strong>210-290 Ohm</strong>: KEYCODE_VOLUME_UP</li> 4653 <li><strong>360-680 Ohm</strong>: KEYCODE_VOLUME_DOWN</li> 4654 </ul></li> 4655 <li>SHOULD support the detection and mapping to the keycode for the following range 4656of equivalent impedance between the microphone and ground conductors on the 4657audio plug: 4658 <ul> 4659 <li><strong>110-180 Ohm: </strong>KEYCODE_VOICE_ASSIST</li> 4660 </ul></li> 4661 <li>MUST trigger ACTION_HEADSET_PLUG upon a plug insert, but only after all 4662contacts on plug are touching their relevant segments on the jack.</li> 4663 <li>MUST be capable of driving at least 150mV ± 10% of output voltage on a 32 Ohm 4664speaker impedance.</li> 4665 <li>MUST have a microphone bias voltage between 1.8V ~ 2.9V.</li> 4666</ul> 4667 4668<h3 id="7_8_3_near_ultrasound">7.8.3. Near-Ultrasound </h3> 4669 4670<p>Near-Ultrasound audio is the 18.5 kHz to 20 kHz band. 4671Device implementations MUST correctly report the support 4672of near-ultrasound audio capability via the 4673<a href="http://developer.android.com/reference/android/media/AudioManager.html#getProperty(java.lang.String)">AudioManager.getProperty</a> 4674API as follows: 4675</p> 4676 4677<ul> 4678 <li>If 4679 <a href="http://developer.android.com/reference/android/media/AudioManager.html#PROPERTY_SUPPORT_MIC_NEAR_ULTRASOUND">PROPERTY_SUPPORT_MIC_NEAR_ULTRASOUND</a> 4680 is "true", then 4681 <ul> 4682 <li>The microphone's mean power response in the 18.5 kHz to 20 kHz band MUST be no more than 4683 15 dB below the response at 2 kHz.</li> 4684 <li>The signal to noise ratio of the microphone MUST be no lower than 80 dB.</li> 4685 </ul> 4686 </li> 4687 <li>If 4688 <a href="http://developer.android.com/reference/android/media/AudioManager.html#PROPERTY_SUPPORT_SPEAKER_NEAR_ULTRASOUND">PROPERTY_SUPPORT_SPEAKER_NEAR_ULTRASOUND</a> 4689 is "true", then the speaker's mean response in 18.5 kHz - 20 kHz MUST be no lower than 40 dB 4690 below the response at 2 kHz. 4691 </li> 4692</ul> 4693 4694<h1 id="8_performance_power">8. Performance and Power</h1> 4695 4696 4697<p>Some minimum performance and power criteria are critical to the user experience 4698and impact the baseline assumptions developers would have when developing an app. 4699Android Watch devices SHOULD and other type of device implementations MUST meet 4700the following criteria:</p> 4701 4702<h2 id="8_1_user_experience_consistency">8.1. User Experience Consistency</h2> 4703 4704 4705<p>Device implementations MUST provide a smooth user interface by ensuring a 4706consistent frame rate and response times for applications and games. Device 4707implementations MUST meet the following requirements: </p> 4708 4709<ul> 4710 <li><strong>Consistent frame latency</strong>. Inconsistent frame latency or a delay to render frames MUST NOT happen more 4711often than 5 frames in a second, and SHOULD be below 1 frames in a second.</li> 4712 <li><strong>User interface latency</strong>. Device implementations MUST ensure low latency user experience by scrolling a 4713list of 10K list entries as defined by the Android Compatibility Test Suite 4714(CTS) in less than 36 secs.</li> 4715 <li><strong>Task switching</strong>. When multiple applications have been launched, re-launching an already-running 4716application after it has been launched MUST take less than 1 second.</li> 4717</ul> 4718 4719<h2 id="8_2_file_i_o_access_performance">8.2. File I/O Access Performance</h2> 4720 4721 4722<p>Device implementations MUST ensure internal storage file access performance consistency for read 4723and write operations. </p> 4724 4725<ul> 4726 <li><strong>Sequential write</strong>. Device implementations MUST ensure a sequential write performance of at least 5MB/s 4727for a 256MB file using 10MB write buffer.</li> 4728 <li><strong>Random write</strong>. Device implementations MUST ensure a random write performance of at least 0.5MB/s for a 4729256MB file using 4KB write buffer.</li> 4730 <li><strong>Sequential read</strong>. Device implementations MUST ensure a sequential read performance of at least 15MB/s for 4731a 256MB file using 10MB write buffer.</li> 4732 <li><strong>Random read</strong>. Device implementations MUST ensure a random read performance of at least 3.5MB/s for a 4733256MB file using 4KB write buffer.</li> 4734</ul> 4735 4736<h2 id="8_3_power_saving_modes">8.3. Power-Saving Modes</h2> 4737 4738<p>All apps exempted from App Standby and/or Doze mode MUST be made visible to 4739the end user. Further, the triggering, maintenance, wakeup algorithms and 4740the use of Global system settings of these power-saving modes MUST not deviate 4741from the Android Open Source Project.</p> 4742 4743<h2 id="8_4_power_consumption_accounting">8.4. Power Consumption Accounting</h2> 4744 4745<p>A more accurate accounting and reporting of the power consumption provides the 4746app developer both the incentives and the tools to optimize the power usage pattern 4747of the application. Therefore, device implementations:</p> 4748 4749<ul> 4750 <li>MUST be able to track hardware component power usage and attribute that power 4751 usage to specific applications. Specifically, implementations: 4752 <ul> 4753 <li>MUST provide a per-component power profile that defines the current consumption 4754 value for each hardware component and the approximate battery drain caused by the 4755 components over time as documented in the Android Open Source Project site [<a 4756href="http://source.android.com/devices/tech/power/values.html">Resources, 123</a>].</li> 4757 <li>MUST report all power consumption values in milliampere hours (mAh)</li> 4758 <li>SHOULD be attributed to the hardware component itself if unable to 4759 attribute hardware component power usage to an application.</li> 4760 <li>MUST report CPU power consumption per each process's UID. The Android Open 4761 Source Project meets the requirement through the <code>uid_cputime</code> 4762 kernel module implementation.</li> 4763 </ul> 4764 </li> 4765 <li>MUST make this power usage available via the <code>adb shell dumpsys 4766 batterystats</code> shell command to the app developer [<a 4767href="http://source.android.com/devices/tech/power/batterystats.html">Resources, 124</a>].</li> 4768 <li>MUST honor the android.intent.action.POWER_USAGE_SUMMARY intent and display 4769 a settings menu that shows this power usage [<a 4770href="http://developer.android.com/reference/android/content/Intent.html#ACTION_POWER_USAGE_SUMMARY">Resources, 4771125</a>].</li> 4772</ul> 4773 4774<h1 id="9_security_model_compatibility">9. Security Model Compatibility</h1> 4775 4776 4777<p>Device implementations MUST implement a security model consistent with the 4778Android platform security model as defined in Security and Permissions 4779reference document in the APIs [<a href="http://developer.android.com/guide/topics/security/permissions.html">Resources, 126</a>] in the Android developer documentation. Device implementations MUST support 4780installation of self-signed applications without requiring any additional 4781permissions/certificates from any third parties/authorities. Specifically, 4782compatible devices MUST support the security mechanisms described in the follow 4783subsections.</p> 4784 4785<h2 id="9_1_permissions">9.1. Permissions</h2> 4786 4787 4788<p>Device implementations MUST support the Android permissions model as defined in 4789the Android developer documentation [<a href="http://developer.android.com/guide/topics/security/permissions.html">Resources, 126</a>]. Specifically, implementations MUST enforce each permission defined as 4790described in the SDK documentation; no permissions may be omitted, altered, or 4791ignored. Implementations MAY add additional permissions, provided the new 4792permission ID strings are not in the android.* namespace.</p> 4793 4794<p>Permissions with a protection level of dangerous are runtime permissions. Applications 4795with targetSdkVersion > 22 request them at runtime. Device implementations:</p> 4796 4797<ul> 4798<li>MUST show a dedicated interface for the user to decide whether to grant the 4799requested runtime permissions and also provide an interface for the user to manage 4800runtime permissions.</li> 4801<li>MUST have one and only one implementation of both user interfaces.</li> 4802<li>MUST NOT grant any runtime permissions to preinstalled apps unless: 4803 <ul> 4804 <li>the user's consent can be obtained before the application uses it</li> 4805 <li>the runtime permissions are associated with an intent pattern for which the preinstalled 4806 application is set as the default handler</li> 4807 </ul> 4808</li> 4809</ul> 4810 4811<h2 id="9_2_uid_and_process_isolation">9.2. UID and Process Isolation</h2> 4812 4813 4814<p>Device implementations MUST support the Android application sandbox model, in 4815which each application runs as a unique Unixstyle UID and in a separate 4816process. Device implementations MUST support running multiple applications as 4817the same Linux user ID, provided that the applications are properly signed and 4818constructed, as defined in the Security and Permissions reference [<a href="http://developer.android.com/guide/topics/security/permissions.html">Resources, 126</a>].</p> 4819 4820<h2 id="9_3_filesystem_permissions">9.3. Filesystem Permissions</h2> 4821 4822 4823<p>Device implementations MUST support the Android file access permissions model 4824as defined in the Security and Permissions reference [<a href="http://developer.android.com/guide/topics/security/permissions.html">Resources, 126</a>].</p> 4825 4826<h2 id="9_4_alternate_execution_environments">9.4. Alternate Execution Environments</h2> 4827 4828 4829<p>Device implementations MAY include runtime environments that execute 4830applications using some other software or technology than the Dalvik Executable 4831Format or native code. However, such alternate execution environments MUST NOT 4832compromise the Android security model or the security of installed Android 4833applications, as described in this section.</p> 4834 4835<p>Alternate runtimes MUST themselves be Android applications, and abide by the 4836standard Android security model, as described elsewhere in <a href="#9_security_model_compatibility">section 9</a>.</p> 4837 4838<p>Alternate runtimes MUST NOT be granted access to resources protected by 4839permissions not requested in the runtime’s AndroidManifest.xml file via the 4840<uses-permission> mechanism.</p> 4841 4842<p>Alternate runtimes MUST NOT permit applications to make use of features 4843protected by Android permissions restricted to system applications.</p> 4844 4845<p>Alternate runtimes MUST abide by the Android sandbox model. Specifically, 4846alternate runtimes:</p> 4847 4848<ul> 4849 <li>SHOULD install apps via the PackageManager into separate Android sandboxes ( 4850Linux user IDs, etc.).</li> 4851 <li>MAY provide a single Android sandbox shared by all applications using the 4852alternate runtime.</li> 4853 <li>and installed applications using an alternate runtime, MUST NOT reuse the 4854sandbox of any other app installed on the device, except through the standard 4855Android mechanisms of shared user ID and signing certificate.</li> 4856 <li>MUST NOT launch with, grant, or be granted access to the sandboxes 4857corresponding to other Android applications.</li> 4858 <li>MUST NOT be launched with, be granted, or grant to other applications any 4859privileges of the superuser (root), or of any other user ID.</li> 4860</ul> 4861 4862<p>The .apk files of alternate runtimes MAY be included in the system image of a 4863device implementation, but MUST be signed with a key distinct from the key used 4864to sign other applications included with the device implementation.</p> 4865 4866<p>When installing applications, alternate runtimes MUST obtain user consent for 4867the Android permissions used by the application. If an application needs to 4868make use of a device resource for which there is a corresponding Android 4869permission (such as Camera, GPS, etc.), the alternate runtime MUST inform the 4870user that the application will be able to access that resource. If the runtime 4871environment does not record application capabilities in this manner, the 4872runtime environment MUST list all permissions held by the runtime itself when 4873installing any application using that runtime.</p> 4874 4875<h2 id="9_5_multi-user_support">9.5. Multi-User Support</h2> 4876 4877<div class="note"> 4878<p>This feature is optional for all device types.</p> 4879</div> 4880 4881 4882<p>Android includes support for multiple users and provides support for full user 4883isolation [<a href="http://developer.android.com/reference/android/os/UserManager.html">Resources, 127</a>]. Device implementations MAY enable multiple users, but when enabled MUST meet 4884the following requirements related to multi-user support [<a href="http://source.android.com/devices/storage/traditional.html">Resources, 128</a>]:</p> 4885 4886<ul> 4887 <li>Device implementations that do not declare the android.hardware.telephony 4888feature flag MUST support restricted profiles, a feature that allows device 4889owners to manage additional users and their capabilities on the device. With 4890restricted profiles, device owners can quickly set up separate environments for 4891additional users to work in, with the ability to manage finer-grained 4892restrictions in the apps that are available in those environments.</li> 4893 <li>Conversely device implementations that declare the android.hardware.telephony 4894feature flag MUST NOT support restricted profiles but MUST align with the AOSP 4895implementation of controls to enable /disable other users from accessing the 4896voice calls and SMS.</li> 4897 <li>Device implementations MUST, for each user, implement a security model 4898consistent with the Android platform security model as defined in Security and 4899Permissions reference document in the APIs [<a href="http://developer.android.com/guide/topics/security/permissions.html">Resources, 126</a>].</li> 4900 <li>Each user instance on an Android device MUST have separate and isolated 4901external storage directories. Device implementations MAY store multiple users' 4902data on the same volume or filesystem. However, the device implementation MUST 4903ensure that applications owned by and running on behalf a given user cannot 4904list, read, or write to data owned by any other user. Note that removable 4905media, such as SD card slots, can allow one user to access another’s data by 4906means of a host PC. For this reason, device implementations that use removable 4907media for the primary external storage APIs MUST encrypt the contents of the SD 4908card if multiuser is enabled using a key stored only on non-removable media accessible 4909only to the system. As this will make the media unreadable by a host PC, device 4910implementations will be required to switch to MTP or a similar system to 4911provide host PCs with access to the current user’s data. Accordingly, device 4912implementations MAY but SHOULD NOT enable multi-user if they use removable 4913media [<a href="http://developer.android.com/reference/android/os/Environment.html">Resources, 129</a>] for primary external storage.</li> 4914</ul> 4915 4916<h2 id="9_6_premium_sms_warning">9.6. Premium SMS Warning</h2> 4917 4918 4919<p>Android includes support for warning users of any outgoing premium SMS message 4920[<a href="http://en.wikipedia.org/wiki/Short_code">Resources, 130</a>]. Premium SMS messages are text messages sent to a service registered with a 4921carrier that may incur a charge to the user. Device implementations that 4922declare support for android.hardware.telephony MUST warn users before sending a 4923SMS message to numbers identified by regular expressions defined in 4924/data/misc/sms/codes.xml file in the device. The upstream Android Open Source 4925Project provides an implementation that satisfies this requirement.</p> 4926 4927<h2 id="9_7_kernel_security_features">9.7. Kernel Security Features</h2> 4928 4929 4930<p>The Android Sandbox includes features that use the Security-Enhanced Linux 4931(SELinux) mandatory access control (MAC) system and other security features in 4932the Linux kernel. SELinux or any other security features implemented below 4933the Android framework:</p> 4934 4935<ul> 4936 <li>MUST maintain compatibility with existing applications.</li> 4937 <li>MUST NOT have a visible user interface when a security violation is detected 4938and successfully blocked, but MAY have a visible user interface when an 4939unblocked security violation occurs resulting in a successful exploit.</li> 4940 <li>SHOULD NOT be user or developer configurable.</li> 4941</ul> 4942 4943<p>If any API for configuration of policy is exposed to an application that can 4944affect another application (such as a Device Administration API), the API MUST 4945NOT allow configurations that break compatibility.</p> 4946 4947<p>Devices MUST implement SELinux or, if using a kernel other than Linux, an 4948equivalent mandatory access control system. Devices MUST also meet the 4949following requirements, which are satisfied by the reference implementation 4950in the upstream Android Open Source Project.</p> 4951 4952<p>Device implementations:</p> 4953 4954<ul> 4955 <li>MUST set SELinux to global enforcing mode.</li> 4956 <li>MUST configure all domains in enforcing mode. No permissive mode domains 4957are allowed, including domains specific to a device/vendor.</li> 4958 <li>MUST NOT modify, omit, or replace the neverallow rules present within the 4959external/sepolicy folder provided in the upstream Android Open Source Project (AOSP) and 4960the policy MUST compile with all neverallow rules present, for both AOSP SELinux 4961domains as well as device/vendor specific domains.</li> 4962</ul> 4963 4964<p>Device implementations SHOULD retain the default SELinux policy provided in the 4965external/sepolicy folder of the upstream Android Open Source Project and only 4966further add to this policy for their own device-specific configuration. Device 4967implementations MUST be compatible with the upstream Android Open Source Project. 4968</p> 4969 4970<h2 id="9_8_privacy">9.8. Privacy</h2> 4971 4972<p>If the device implements functionality in the system that captures the contents 4973displayed on the screen and/or records the audio stream played on the device, 4974it MUST continuously notify the user whenever this functionality is enabled and 4975actively capturing/recording.</p> 4976 4977<p>If a device implementation has a mechanism that routes network data traffic 4978through a proxy server or VPN gateway by default (for example, preloading a VPN 4979service with android.permission.CONTROL_VPN granted), the device implementation 4980MUST ask for the user's consent before enabling that mechanism.</p> 4981 4982<p>If a device implementation has a USB port with USB peripheral mode support, 4983it MUST present a user interface asking for the user's consent before allowing 4984access to the contents of the shared storage over the USB port.</p> 4985 4986<h2 id="9_9_full-disk_encryption">9.9. Full-Disk Encryption</h2> 4987 4988<div class="note"> 4989<p>Optional for Android device implementations without a lock screen.</p> 4990</div> 4991 4992<p>If the device implementation supports a secure lock screen reporting "<code>true</code>" 4993for KeyguardManager.isDeviceSecure() 4994[<a href="http://developer.android.com/reference/android/app/KeyguardManager.html#isDeviceSecure()">Resources, 131</a>], 4995and is not a device with restricted memory as reported through the 4996ActivityManager.isLowRamDevice() method, then the device MUST support full-disk encryption 4997[<a href="http://source.android.com/devices/tech/security/encryption/index.html">Resources, 132</a>] 4998of the application private data (/data partition), as well as the application 4999shared storage partition (/sdcard partition) if it is a permanent, non-removable 5000part of the device.</p> 5001 5002<p>For device implementations supporting full-disk encryption and with Advanced 5003Encryption Standard (AES) crypto performance above 50MiB/sec, the full-disk 5004encryption MUST be enabled by default at the time the user has completed the out-of-box 5005setup experience. If a device implementation is already launched on an earlier Android 5006version with full-disk encryption disabled by default, such a device cannot 5007meet the requirement through a system software update and thus MAY be exempted.</p> 5008 5009<p>Encryption MUST use AES with a key of 128-bits (or greater) and a mode designed 5010for storage (for example, AES-XTS, AES-CBC-ESSIV). The encryption key MUST NOT 5011be written to storage at any time without being encrypted. Other than when in 5012active use, the encryption key SHOULD be AES encrypted with the lockscreen 5013passcode stretched using a slow stretching algorithm (e.g. PBKDF2 or scrypt). 5014If the user has not specified a lockscreen passcode or has disabled use of the 5015passcode for encryption, the system SHOULD use a default passcode to wrap the 5016encryption key. If the device provides a hardware-backed keystore, the password 5017stretching algorithm MUST be cryptographically bound to that keystore. The 5018encryption key MUST NOT be sent off the device (even when wrapped with the user 5019passcode and/or hardware bound key). The upstream Android Open Source project 5020provides a preferred implementation of this feature based on the Linux kernel 5021feature dm-crypt.</p> 5022 5023<h2 id="9_10_verified_boot">9.10. Verified Boot</h2> 5024 5025<p> 5026Verified boot is a feature that guarantees the integrity of the device software. 5027If a device implementation supports the feature, it MUST: 5028</p> 5029<ul> 5030<li>Declare the platform feature flag android.software.verified_boot</li> 5031<li>Perform verification on every boot sequence</li> 5032<li>Start verification from an immutable hardware key that is the root of trust, 5033and go all the way up to the system partition</li> 5034<li>Implement each stage of verification to check the integrity and authenticity 5035of all the bytes in the next stage before executing the code in the next stage</li> 5036<li>Use verification algorithms as strong as current recommendations 5037from NIST for hashing algorithms (SHA-256) and public key sizes (RSA-2048)</li> 5038</ul> 5039 5040<p>The upstream Android Open Source Project provides a preferred implementation of this 5041feature based on the Linux kernel feature dm-verity.</p> 5042 5043<p>Starting from Android 6.0, device implementations with Advanced Encryption Standard (AES) 5044crypto perfomance above 50MiB/seconds MUST support verified boot for device integrity. 5045If a device implementation is already launched without supporting verified boot on an earlier 5046version of Android, such a device can not add support for this feature with a system software 5047update and thus are exempted from the requirement.</p> 5048 5049<h2 id="9_11_keys_and_credentials">9.11. Keys and Credentials</h2> 5050 5051<p>The Android Keystore System 5052[<a href="https://developer.android.com/training/articles/keystore.html">Resources, 133</a>] 5053allows app developers to store cryptographic keys in a container and use them in cryptographic 5054operations through the KeyChain API 5055[<a href="https://developer.android.com/reference/android/security/KeyChain.html">Resources, 134</a>] 5056or the Keystore API 5057 [<a href="https://developer.android.com/reference/java/security/KeyStore.html">Resources, 135</a>]. 5058</p> 5059 5060<p>All Android device implementations MUST meet the following requirements:</p> 5061 5062<ul> 5063<li>SHOULD not limit the number of keys that can be generated, and MUST at least allow more 5064than 8,192 keys to be imported.</li> 5065<li>The lock screen authentication MUST rate limit attempts and SHOULD have an exponential 5066 backoff algorithm as implemented in the Android Open Source Project.</li> 5067<li>When the device implementation supports a secure lock screen and has a secure hardware 5068 such as a Secure Element (SE) where a Trusted Execution Environment (TEE) can be implemented, 5069 then it: 5070 <ul> 5071 <li>Is STRONGLY RECOMMENDED to back up the keystore implementation with the secure hardware. 5072 The upstream Android Open Source Project provides the Keymaster Hardware Abstraction Layer 5073 (HAL) implementation that can be used to satisfy this requirement.</li> 5074 <li>MUST perform the lock screen authentication in the secure hardware if the device has a 5075 hardware-backed keystore implementation and only when successful allow the authentication-bound 5076 keys to be used. The upstream Android Open Source Project provides the Gatekeeper Hardware 5077 Abstraction Layer (HAL) that can be used to satisfy this requirement 5078 [<a href="http://source.android.com/devices/tech/security/authentication/gatekeeper.html">Resources, 136</a>].</li> 5079 </ul> 5080</li> 5081</ul> 5082 5083<p>Note that while the above TEE-related requirements are stated as STRONGLY RECOMMENDED, the 5084 Compatibility Definition for the next API version is planned to changed these to REQIUIRED. If a 5085 device implementation is already launched on an earlier Android version and has not implemented a 5086 trusted operating system on the secure hardware, such a device might not be able to meet the 5087 requirements through a system software update and thus is STRONGLY RECOMMENDED to implement a 5088 TEE.</p> 5089 5090<h2 id="9_12_data_deletion">9.12. Data Deletion</h2> 5091 5092<p>Devices MUST provide users with a mechanism to perform a "Factory Data Reset" 5093that allows logical and physical deletion of all data except for the system image 5094and data in other partitions that can be regarded as part of the sytem image. 5095This MUST satisfy relevant industry standards for data deletion such as NIST SP800-88. 5096This MUST be used for the implementation of the wipeData() API (part of the Android Device 5097Administration API) described in <a href="#3_9_device_administration">section 3.9 Device 5098Administration</a>.</p> 5099 5100<p>Devices MAY provide a fast data wipe that conducts a logical data erase.</p> 5101 5102<h1 id="10_software_compatibility_testing">10. Software Compatibility Testing</h1> 5103 5104 5105<p>Device implementations MUST pass all tests described in this section.</p> 5106 5107<p>However, note that no software test package is fully comprehensive. For this 5108reason, device implementers are <strong>STRONGLY RECOMMENDED</strong> to make the minimum number of changes as possible to the reference and 5109preferred implementation of Android available from the Android Open Source 5110Project. This will minimize the risk of introducing bugs that create 5111incompatibilities requiring rework and potential device updates.</p> 5112 5113<h2 id="10_1_compatibility_test_suite">10.1. Compatibility Test Suite</h2> 5114 5115 5116<p>Device implementations MUST pass the Android Compatibility Test Suite (CTS) [<a href="http://source.android.com/compatibility/index.html">Resources, 137</a>] available from the Android Open Source Project, using the final shipping 5117software on the device. Additionally, device implementers SHOULD use the 5118reference implementation in the Android Open Source tree as much as possible, 5119and MUST ensure compatibility in cases of ambiguity in CTS and for any 5120reimplementations of parts of the reference source code.</p> 5121 5122<p>The CTS is designed to be run on an actual device. Like any software, the CTS 5123may itself contain bugs. The CTS will be versioned independently of this 5124Compatibility Definition, and multiple revisions of the CTS may be released for 5125Android 6.0. Device implementations MUST pass the latest CTS version available 5126at the time the device software is completed.</p> 5127 5128<h2 id="10_2_cts_verifier">10.2. CTS Verifier</h2> 5129 5130 5131<p>Device implementations MUST correctly execute all applicable cases in the CTS 5132Verifier. The CTS Verifier is included with the Compatibility Test Suite, and 5133is intended to be run by a human operator to test functionality that cannot be 5134tested by an automated system, such as correct functioning of a camera and 5135sensors.</p> 5136 5137<p>The CTS Verifier has tests for many kinds of hardware, including some hardware 5138that is optional. Device implementations MUST pass all tests for hardware that 5139they possess; for instance, if a device possesses an accelerometer, it MUST 5140correctly execute the Accelerometer test case in the CTS Verifier. Test cases 5141for features noted as optional by this Compatibility Definition Document MAY be 5142skipped or omitted.</p> 5143 5144<p>Every device and every build MUST correctly run the CTS Verifier, as noted 5145above. However, since many builds are very similar, device implementers are not 5146expected to explicitly run the CTS Verifier on builds that differ only in 5147trivial ways. Specifically, device implementations that differ from an 5148implementation that has passed the CTS Verifier only by the set of included 5149locales, branding, etc. MAY omit the CTS Verifier test.</p> 5150 5151<h1 id="11_updatable_software">11. Updatable Software</h1> 5152 5153 5154<p>Device implementations MUST include a mechanism to replace the entirety of the 5155system software. The mechanism need not perform “live” upgrades—that is, a 5156device restart MAY be required.</p> 5157 5158<p>Any method can be used, provided that it can replace the entirety of the 5159software preinstalled on the device. For instance, any of the following 5160approaches will satisfy this requirement:</p> 5161 5162<ul> 5163 <li>“Over-the-air (OTA)” downloads with offline update via reboot</li> 5164 <li>“Tethered” updates over USB from a host PC</li> 5165 <li>“Offline” updates via a reboot and update from a file on removable storage</li> 5166</ul> 5167 5168<p>However, if the device implementation includes support for an unmetered data 5169connection such as 802.11 or Bluetooth PAN (Personal Area Network) profile:</p> 5170 5171<ul> 5172<li>Android Automotive implementations SHOULD support OTA downloads with offline 5173update via reboot.</li> 5174<li>All other device implementations MUST support OTA downloads with offline 5175update via reboot.</li> 5176</ul> 5177 5178<p>The update mechanism used MUST support updates without wiping user data. That 5179is, the update mechanism MUST preserve application private data and application 5180shared data. Note that the upstream Android software includes an update 5181mechanism that satisfies this requirement.</p> 5182 5183<p>For device implementations that are launching with Android 6.0 and later, the 5184update mechanism SHOULD support verifying that the system image is binary 5185identical to expected result following an OTA. The block-based OTA 5186implementation in the upstream Android Open Source Project, added since Android 51875.1, satisfies this requirement.</p> 5188 5189<p>If an error is found in a device implementation after it has been released but 5190within its reasonable product lifetime that is determined in consultation with 5191the Android Compatibility Team to affect the compatibility of third-party 5192applications, the device implementer MUST correct the error via a software 5193update available that can be applied per the mechanism just described.</p> 5194 5195<p>Android includes features that allow the Device Owner app (if present) to control the 5196installation of system updates. To facilitate this, the system update subsystem 5197for devices that report android.software.device_admin MUST implement the behavior 5198described in the SystemUpdatePolicy class 5199[<a href="http://developer.android.com/reference/android/app/admin/SystemUpdatePolicy.html"> 5200Resources, 138</a>].</p> 5201 5202<h1 id="12_document_changelog">12. Document Changelog</h1> 5203 5204<p>The following table contains a summary of the changes to the Compatibility 5205Definition in this release.</p> 5206<table> 5207 <tr> 5208 <th>Section</th> 5209 <th>Summary of changes</th> 5210 </tr> 5211 <tr> 5212 <td>Various</td> 5213 <td>Replaced instances of the "encouraged" term with "RECOMMENDED"</td> 5214 </tr> 5215 <tr> 5216 <td>2. Device Types</td> 5217 <td>Update for Android Automotive implementations</td> 5218 </tr> 5219 <tr> 5220 <td>3.2.2. Build Parameters</td> 5221 <td>Additions for the hardware serial number and for the security patch level of a build</td> 5222 </tr> 5223 <tr> 5224 <td>3.2.3.2. Intent Resolution</td> 5225 <td>Section renamed from "Intent Overrides" to "Intent Resolution," with new requirements related to authoritative default app linking</td> 5226 </tr> 5227 <tr> 5228 <td>3.3.1. Application Binary Interfaces</td> 5229 <td>Additions for Android ABI support; change related to Vulkan library name</td> 5230 </tr> 5231 <tr> 5232 <td>3.4.1. WebView Compatibility</td> 5233 <td>Change for the user agent string reported by the WebView</td> 5234 </tr> 5235 <tr> 5236 <td>3.7. Runtime Compatibility</td> 5237 <td>Updates to memory allocation table</td> 5238 </tr> 5239 <tr> 5240 <td>3.8.4. Search</td> 5241 <td>Updates regarding Assistant requirements</td> 5242 </tr> 5243 <tr> 5244 <td>3.8.6. Themes</td> 5245 <td>Added requirement to support black system icons when requested by the SYSTEM_UI_FLAG_LIGHT_STATUS_BAR flag</td> 5246 </tr> 5247 <tr> 5248 <td>3.9.1. Device Provisioning</td> 5249 <td>Contains new sections for device owner provisioning and managed profile provisioning</td> 5250 </tr> 5251 <tr> 5252 <td>3.9.2. Managed Profile Support</td> 5253 <td>New section with requirements for device support of managed profile functionality</td> 5254 </tr> 5255<tr> 5256 <td>3.12.1. TV App</td> 5257 <td>Added section to clarify TV App requirements for Android Television devices</td> 5258 </tr> 5259 <tr> 5260 <td>3.12.1.1. Electronic Program Guide</td> 5261 <td>Added section to clarify EPG requirements for Android Television devices</td> 5262 </tr> 5263 <tr> 5264 <td>3.12.1.2. Navigation</td> 5265 <td>Added section to clarify TV App navigation requirements for Android Television devices</td> 5266 </tr> 5267 <td>3.12.1.3. TV input app linking</td> 5268 <td>Added section to clarify TV input app linking support requirements for Android Television devices</td> 5269 </tr> 5270 <tr> 5271 <td>5.1. Media Codecs</td> 5272 <td>Updates regarding support for core media formats and decoding.</td> 5273 </tr> 5274 <tr> 5275 <td>5.1.3. Video Codecs</td> 5276 <td>Changes and additions related to Android Televisions</td> 5277 </tr> 5278 <tr> 5279 <td>5.2. Video Encoding</td> 5280 <td>Changes for encoders</td> 5281 </tr> 5282 <tr> 5283 <td>5.3. Video Decoding</td> 5284 <td>Changes for decoders, including regarding support for dynamic video resolution, frame rate 5285switching, and more</td> 5286 </tr> 5287 <tr> 5288 <td>5.4. Audio Recording</td> 5289 <td>Additions related to audio capture</td> 5290 </tr> 5291 <tr> 5292 <td>5.6. Audio Latency</td> 5293 <td>Update regarding reporting of support for low-latency audio</td> 5294 </tr> 5295 <tr> 5296 <td>5.10. Professional Audio</td> 5297 <td>General updates for professional audio support; updates for mobile device (jack) specifications, USB audio host mode, and other updates</td> 5298 </tr> 5299 <tr> 5300 <td>5.9. Musical Instrument Digital Interface (MIDI)</td> 5301 <td>Added new section on optional Musical Instrument Digital Interface (MIDI) support</td> 5302 </tr> 5303<tr> 5304 <td>6.1. Developer Tools</td> 5305 <td>Update for drivers supporting Windows 10</td> 5306 </tr> 5307 <tr> 5308 <td>7.1.1.3. Screen Density</td> 5309 <td>Updates for screen density, for example related to an Android watch</td> 5310 </tr> 5311 <tr> 5312 <td>7.2.3. Navigation Keys</td> 5313 <td>Updated requirements for device implementations that include the Assist action</td> 5314 </tr> 5315 <tr> 5316 <td>7.3. Sensors (and subsections)</td> 5317 <td>New requirements for some sensor types</td> 5318 </tr> 5319 <tr> 5320 <td>7.3.9. High Fidelity Sensors</td> 5321 <td>New section with requirements for devices supporting high fidelity sensors</td> 5322 </tr> 5323 <tr> 5324 <td>7.3.10. Fingerprint Sensor</td> 5325 <td>New section on requirements related to fingerprint sensors</td> 5326 </tr> 5327 <tr> 5328 <td>7.4.2. IEEE 802.11 (Wi-Fi)</td> 5329 <td>Updates regarding support for multicast DNS (mDNS)</td> 5330 </tr> 5331 <tr> 5332 <td>7.4.3. Bluetooth</td> 5333 <td>Addition related to Resolvable Private Address (RPA) for Bluetooth Low Energy (BLE)</td> 5334 </tr> 5335 <tr> 5336 <td>7.4.4. Near-Field Communications</td> 5337 <td>Additions to requirements for Near-Field Communications (NFC)</td> 5338 </tr> 5339 <tr> 5340 <td>7.4.5. Minimum Network Capability</td> 5341 <td>Added requirements for IPv6 support</td> 5342 </tr> 5343 <tr> 5344 <td>7.6.3. Adoptable Storage</td> 5345 <td>New section for implementation of adoptable storage</td> 5346 </tr> 5347 <tr> 5348 <td>7.7. USB</td> 5349 <td>Requirement related to implementing the AOA specification</td> 5350 </tr> 5351 <tr> 5352 <td>7.8.3. Near-Ultrasound</td> 5353 <td>Additions related to near-ultrasound recording, playback, and audio</td> 5354 </tr> 5355 <tr> 5356 <td>8.3. Power-Saving Modes</td> 5357 <td>New section with requirements regarding the App Standby and Doze modes</td> 5358 </tr> 5359<tr> 5360 <td>8.4. Power Consumption Accounting</td> 5361 <td>New section with requirements for tracking hardware component power usage and attributing that power usage to specific applications</td> 5362 </tr> 5363 <tr> 5364 <td>9.1. Permissions</td> 5365 <td>Addition to Permissions requirements</td> 5366 </tr> 5367<tr> 5368 <td>9.7. Kernel Security Features</td> 5369 <td>SE Linux updates</td> 5370 </tr> 5371<tr> 5372 <td>9.8. Privacy</td> 5373 <td>Addition regarding user's consent for access to shared storage over a USB port</td> 5374 </tr> 5375 <tr> 5376 <td>9.9. Full-Disk Encryption</td> 5377 <td>Requirements related to full disk encryption</td> 5378 </tr> 5379 <tr> 5380 <td>9.10. Verified Boot</td> 5381 <td>Additional requirement for verified boot</td> 5382 </tr> 5383 <tr> 5384 <td>9.11. Keys and Credentials</td> 5385 <td>New section of requirements related to keys and credentials</td> 5386 </tr> 5387 <tr> 5388 <td>9.12. Data Deletion</td> 5389 <td>New section for "Factory Data Reset"</td> 5390 </tr> 5391 <tr> 5392 <td>11. Updatable Software</td> 5393 <td>Requirement related to the system update policy set by the device owner</td> 5394 </tr> 5395 </table> 5396 5397 5398<h1 id="13_contact_us">13. Contact Us</h1> 5399 5400 5401<p>You can join the android-compatibility forum <a href="https://groups.google.com/forum/#!forum/android-compatibility">[Resources, 139</a>] and ask for clarifications or bring up any issues that you think the document 5402does not cover.</p> 5403 5404<h1 id="14_resources">14. Resources</h1> 5405 5406<p>1. IETF RFC2119 Requirement Levels: <a href="http://www.ietf.org/rfc/rfc2119.txt">http://www.ietf.org/rfc/rfc2119.txt</a></p> 5407 5408<p>2. Android Open Source Project: <a href="http://source.android.com/">http://source.android.com/</a></p> 5409 5410<p>3. Android Television features: <a href="http://developer.android.com/reference/android/content/pm/PackageManager.html#FEATURE_LEANBACK">http://developer.android.com/reference/android/content/pm/PackageManager.html#FEATURE_LEANBACK</a></p> 5411 5412<p>4. Android Watch feature: <a href="http://developer.android.com/reference/android/content/res/Configuration.html#UI_MODE_TYPE_WATCH">http://developer.android.com/reference/android/content/res/Configuration.html#UI_MODE_TYPE_WATCH</a></p> 5413 5414<p>5. Android UI_MODE_TYPE_CAR API: <a href="http://developer.android.com/reference/android/content/res/Configuration.html#UI_MODE_TYPE_CAR">http://developer.android.com/reference/android/content/res/Configuration.html#UI_MODE_TYPE_CAR</a></p> 5415 5416<p>6. API definitions and documentation: <a href="http://developer.android.com/reference/packages.html">http://developer.android.com/reference/packages.html</a></p> 5417 5418<p>7. Android Permissions reference: <a href="http://developer.android.com/reference/android/Manifest.permission.html">http://developer.android.com/reference/android/Manifest.permission.html</a></p> 5419 5420<p>8. android.os.Build reference: <a href="http://developer.android.com/reference/android/os/Build.html">http://developer.android.com/reference/android/os/Build.html</a></p> 5421 5422<p>9. Android 6.0 allowed version strings: <a href="http://source.android.com/compatibility/6.0/versions.html">http://source.android.com/compatibility/6.0/versions.html</a></p> 5423 5424<p>10. Android Developer Settings: <a href="http://developer.android.com/reference/android/provider/Settings.html">http://developer.android.com/reference/android/provider/Settings.html</a></p> 5425 5426<p>11. Telephony Provider: <a href="http://developer.android.com/reference/android/provider/Telephony.html">http://developer.android.com/reference/android/provider/Telephony.html</a></p> 5427 5428<p>12. Android NDK ABI Management: <a href="https://developer.android.com/ndk/guides/abis.html">https://developer.android.com/ndk/guides/abis.html</a></p> 5429 5430<p>13. Advanced SIMD architecture: <a href="http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.ddi0388f/Beijfcja.html">http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.ddi0388f/Beijfcja.html</a></p> 5431 5432<p>14. Android Extension Pack: <a href="http://developer.android.com/guide/topics/graphics/opengl.html#aep">http://developer.android.com/guide/topics/graphics/opengl.html#aep</a></p> 5433 5434<p>15. android.webkit.WebView class: <a href="http://developer.android.com/reference/android/webkit/WebView.html">http://developer.android.com/reference/android/webkit/WebView.html</a></p> 5435 5436<p>16. WebView compatibility: <a href="http://www.chromium.org/">http://www.chromium.org/</a></p> 5437 5438<p>17. HTML5: <a href="http://html.spec.whatwg.org/multipage/">http://html.spec.whatwg.org/multipage/</a></p> 5439 5440<p>18. HTML5 offline capabilities:<a href="http://dev.w3.org/html5/spec/Overview.html#offline"> http://dev.w3.org/html5/spec/Overview.html#offline</a></p> 5441 5442<p>19. HTML5 video tag: <a href="http://dev.w3.org/html5/spec/Overview.html#video">http://dev.w3.org/html5/spec/Overview.html#video</a></p> 5443 5444<p>20. HTML5/W3C geolocation API: <a href="http://www.w3.org/TR/geolocation-API/">http://www.w3.org/TR/geolocation-API/</a></p> 5445 5446<p>21. HTML5/W3C webstorage API: <a href="http://www.w3.org/TR/webstorage/">http://www.w3.org/TR/webstorage/</a></p> 5447 5448<p>22. HTML5/W3C IndexedDB API: <a href="http://www.w3.org/TR/IndexedDB/">http://www.w3.org/TR/IndexedDB/</a></p> 5449 5450<p>23. Dalvik Executable Format and bytecode specification: available in the 5451Android source code, at dalvik/docs</p> 5452 5453<p>24. AppWidgets: <a href="http://developer.android.com/guide/practices/ui_guidelines/widget_design.html">http://developer.android.com/guide/practices/ui_guidelines/widget_design.html</a></p> 5454 5455<p>25. Notifications: <a href="http://developer.android.com/guide/topics/ui/notifiers/notifications.html">http://developer.android.com/guide/topics/ui/notifiers/notifications.html</a></p> 5456 5457<p>26. Application Resources: <a href="https://developer.android.com/guide/topics/resources/available-resources.html">https://developer.android.com/guide/topics/resources/available-resources.html</a></p> 5458 5459<p>27. Status Bar icon style guide: <a href="http://developer.android.com/design/style/iconography.html">http://developer.android.com/design/style/iconography.html</a></p> 5460 5461<p>28. Notifications Resources: <a href="https://developer.android.com/design/patterns/notifications.html">https://developer.android.com/design/patterns/notifications.html</a></p> 5462 5463<p>29. Search Manager: <a href="http://developer.android.com/reference/android/app/SearchManager.html">http://developer.android.com/reference/android/app/SearchManager.html</a></p> 5464 5465<p>30. Action Assist: <a href="http://developer.android.com/reference/android/content/Intent.html#ACTION_ASSIST">http://developer.android.com/reference/android/content/Intent.html#ACTION_ASSIST</a></p> 5466 5467<p>31. Android Assist APIs: <a href="https://developer.android.com/reference/android/app/assist/package-summary.html">https://developer.android.com/reference/android/app/assist/package-summary.html</a></p> 5468 5469<p>32. Toasts: <a href="http://developer.android.com/reference/android/widget/Toast.html">http://developer.android.com/reference/android/widget/Toast.html</a></p> 5470 5471<p>33. Themes: <a href="http://developer.android.com/guide/topics/ui/themes.html">http://developer.android.com/guide/topics/ui/themes.html</a></p> 5472 5473<p>34. R.style class: <a href="http://developer.android.com/reference/android/R.style.html">http://developer.android.com/reference/android/R.style.html</a></p> 5474 5475<p>35. Material design: <a href="http://developer.android.com/reference/android/R.style.html#Theme_Material">http://developer.android.com/reference/android/R.style.html#Theme_Material</a></p> 5476 5477<p>36. Live Wallpapers: <a href="http://developer.android.com/reference/android/service/wallpaper/WallpaperService.html">http://developer.android.com/reference/android/service/wallpaper/WallpaperService.html</a></p> 5478 5479<p>37. Overview screen resources: <a href="http://developer.android.com/guide/components/recents.html">http://developer.android.com/guide/components/recents.html</a></p> 5480 5481<p>38. Screen pinning: <a href="https://developer.android.com/about/versions/android-5.0.html#ScreenPinning">https://developer.android.com/about/versions/android-5.0.html#ScreenPinning</a></p> 5482 5483<p>39. Input methods: <a href="http://developer.android.com/guide/topics/text/creating-input-method.html">http://developer.android.com/guide/topics/text/creating-input-method.html</a></p> 5484 5485<p>40. Media Notification: <a href="https://developer.android.com/reference/android/app/Notification.MediaStyle.html">https://developer.android.com/reference/android/app/Notification.MediaStyle.html</a></p> 5486 5487<p>41. Dreams: <a href="http://developer.android.com/reference/android/service/dreams/DreamService.html">http://developer.android.com/reference/android/service/dreams/DreamService.html</a></p> 5488 5489<p>42. Settings.Secure LOCATION_MODE: <a href="http://developer.android.com/reference/android/provider/Settings.Secure.html#LOCATION_MODE">http://developer.android.com/reference/android/provider/Settings.Secure.html#LOCATION_MODE</a></p> 5490 5491<p>43. Unicode 6.1.0: <a href="http://www.unicode.org/versions/Unicode6.1.0/">http://www.unicode.org/versions/Unicode6.1.0/</a></p> 5492 5493<p>44. Android Device Administration: <a href="http://developer.android.com/guide/topics/admin/device-admin.html">http://developer.android.com/guide/topics/admin/device-admin.html</a></p> 5494 5495<p>45. DevicePolicyManager reference: <a href="http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html">http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html</a></p> 5496 5497<p>46. Device Owner App: <a href="http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html#isDeviceOwnerApp(java.lang.String)">http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html#isDeviceOwnerApp(java.lang.String)</a></p> 5498 5499 5500<p>47. Android Device Owner Provisioning Flow: <a href="http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html#ACTION_PROVISION_MANAGED_DEVICE">http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html#ACTION_PROVISION_MANAGED_DEVICE</a></p> 5501 5502<p>48. Device Owner Provisioning via NFC: <a href="https://source.android.com/devices/tech/admin/provision.html#device_owner_provisioning_via_nfc">https://source.android.com/devices/tech/admin/provision.html#device_owner_provisioning_via_nfc</a></p> 5503 5504<p>49. Android Profile Owner App:<a href="http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html#isProfileOwnerApp(java.lang.String)">http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html#isProfileOwnerApp(java.lang.String)</a></p> 5505 5506<p>50. Android Managed Profile Provisioning flow: <a href="http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html#ACTION_PROVISION_MANAGED_PROFILE">http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html#ACTION_PROVISION_MANAGED_PROFILE</a></p> 5507 5508<p>51. Android Accessibility Service APIs: <a href="http://developer.android.com/reference/android/accessibilityservice/AccessibilityService.html">http://developer.android.com/reference/android/accessibilityservice/AccessibilityService.html</a></p> 5509 5510<p>52. Android Accessibility APIs: <a href="http://developer.android.com/reference/android/view/accessibility/package-summary.html">http://developer.android.com/reference/android/view/accessibility/package-summary.html</a></p> 5511 5512<p>53. Eyes Free project: <a href="http://code.google.com/p/eyes-free/">http://code.google.com/p/eyes-free</a></p> 5513 5514<p>54. Text-To-Speech APIs: <a href="http://developer.android.com/reference/android/speech/tts/package-summary.html">http://developer.android.com/reference/android/speech/tts/package-summary.html</a></p> 5515 5516<p>55. Television Input Framework: <a href="https://source.android.com/devices/tv/index.html">https://source.android.com/devices/tv/index.html</a></p> 5517 5518<p>56. TV App channels: <a href="http://developer.android.com/reference/android/media/tv/TvContract.Channels.html">http://developer.android.com/reference/android/media/tv/TvContract.Channels.html</a></p> 5519 5520<p>57. Third-party TV inputs: <a href="https://source.android.com/devices/tv/index.html#third-party_input_example">https://source.android.com/devices/tv/index.html#third-party_input_example</a></p> 5521 5522<p>58. TV inputs: <a href="https://source.android.com/devices/tv/index.html#tv_inputs">https://source.android.com/devices/tv/index.html#tv_inputs</a></p> 5523 5524<p>59. TV channel EPG fields: <a href="https://developer.android.com/reference/android/media/tv/TvContract.Programs.html">https://developer.android.com/reference/android/media/tv/TvContract.Programs.html</a></p> 5525 5526<p>60. TV input app linking: <a href="http://developer.android.com/reference/android/media/tv/TvContract.Channels.html#COLUMN_APP_LINK_INTENT_URI">http://developer.android.com/reference/android/media/tv/TvContract.Channels.html#COLUMN_APP_LINK_INTENT_URI</a></p> 5527 5528<p>61. Reference tool documentation (for adb, aapt, ddms, systrace): <a href="http://developer.android.com/tools/help/index.html">http://developer.android.com/tools/help/index.html</a></p> 5529 5530<p>62. Android apk file description: <a href="http://developer.android.com/guide/components/fundamentals.html">http://developer.android.com/guide/components/fundamentals.html</a></p> 5531 5532<p>63. Manifest files: <a href="http://developer.android.com/guide/topics/manifest/manifest-intro.html">http://developer.android.com/guide/topics/manifest/manifest-intro.html</a></p> 5533 5534<p>64. Android Media Formats: <a href="http://developer.android.com/guide/appendix/media-formats.html">http://developer.android.com/guide/appendix/media-formats.html</a></p> 5535 5536<p>65. Android MediaCodecList API: <a href="http://developer.android.com/reference/android/media/MediaCodecList.html">http://developer.android.com/reference/android/media/MediaCodecList.html</a></p> 5537 5538<p>66. Android CamcorderProfile API: <a href="http://developer.android.com/reference/android/media/CamcorderProfile.html">http://developer.android.com/reference/android/media/CamcorderProfile.html</a></p> 5539 5540<p>67. WebM project: <a href="http://www.webmproject.org/">http://www.webmproject.org/</a></p> 5541 5542<p>68. RTC Hardware Coding Requirements: <a href="http://www.webmproject.org/hardware/rtc-coding-requirements/">http://www.webmproject.org/hardware/rtc-coding-requirements/</a></p> 5543 5544<p>69. AudioEffect API: <a href="http://developer.android.com/reference/android/media/audiofx/AudioEffect.html">http://developer.android.com/reference/android/media/audiofx/AudioEffect.html</a></p> 5545 5546<p>70. Android android.content.pm.PackageManager class and Hardware Features List: <a href="http://developer.android.com/reference/android/content/pm/PackageManager.html">http://developer.android.com/reference/android/content/pm/PackageManager.html</a></p> 5547 5548<p>71. HTTP Live Streaming Draft Protocol: <a href="http://tools.ietf.org/html/draft-pantos-http-live-streaming-03">http://tools.ietf.org/html/draft-pantos-http-live-streaming-03</a></p> 5549 5550<p>72. ADB: <a href="http://developer.android.com/tools/help/adb.html">http://developer.android.com/tools/help/adb.html</a></p> 5551 5552<p>73. Dumpsys: <a href="https://source.android.com/devices/input/diagnostics.html">https://source.android.com/devices/input/diagnostics.html</a></p> 5553 5554<p>74. DDMS: <a href="http://developer.android.com/tools/debugging/ddms.html">http://developer.android.com/tools/debugging/ddms.html</a></p> 5555 5556<p>75. Monkey testing tool: <a href="http://developer.android.com/tools/help/monkey.html">http://developer.android.com/tools/help/monkey.html</a></p> 5557 5558<p>76. SysyTrace tool: <a href="http://developer.android.com/tools/help/systrace.html">http://developer.android.com/tools/help/systrace.html</a></p> 5559 5560<p>77. Android Application Development-Related Settings: <a href="http://developer.android.com/reference/android/provider/Settings.html#ACTION_APPLICATION_DEVELOPMENT_SETTINGS">http://developer.android.com/reference/android/provider/Settings.html#ACTION_APPLICATION_DEVELOPMENT_SETTINGS</a></p> 5561 5562<p>78. Supporting Multiple Screens: <a href="http://developer.android.com/guide/practices/screens_support.html">http://developer.android.com/guide/practices/screens_support.html</a></p> 5563 5564<p>79. android.util.DisplayMetrics: <a href="http://developer.android.com/reference/android/util/DisplayMetrics.html">http://developer.android.com/reference/android/util/DisplayMetrics.html</a></p> 5565 5566<p>80. RenderScript: <a href="http://developer.android.com/guide/topics/renderscript/">http://developer.android.com/guide/topics/renderscript/</a></p> 5567 5568<p>81. Android extension pack for OpenGL ES: <a href="https://developer.android.com/reference/android/opengl/GLES31Ext.html">https://developer.android.com/reference/android/opengl/GLES31Ext.html</a></p> 5569 5570<p>82. Hardware Acceleration: <a href="http://developer.android.com/guide/topics/graphics/hardware-accel.html">http://developer.android.com/guide/topics/graphics/hardware-accel.html</a></p> 5571 5572<p>83. EGL Extension-EGL_ANDROID_RECORDABLE: <a href="http://www.khronos.org/registry/egl/extensions/ANDROID/EGL_ANDROID_recordable.txt">http://www.khronos.org/registry/egl/extensions/ANDROID/EGL_ANDROID_recordable.txt</a></p> 5573 5574<p>84. Display Manager: <a href="http://developer.android.com/reference/android/hardware/display/DisplayManager.html">http://developer.android.com/reference/android/hardware/display/DisplayManager.html</a></p> 5575 5576<p>85. android.content.res.Configuration: <a href="http://developer.android.com/reference/android/content/res/Configuration.html">http://developer.android.com/reference/android/content/res/Configuration.html</a></p> 5577 5578<p>86. Touch Input Configuration: <a href="http://source.android.com/devices/tech/input/touch-devices.html">http://source.android.com/devices/tech/input/touch-devices.html</a></p> 5579 5580<p>87. Motion Event API: <a href="http://developer.android.com/reference/android/view/MotionEvent.html">http://developer.android.com/reference/android/view/MotionEvent.html</a></p> 5581 5582<p>88. Key Event API: <a href="http://developer.android.com/reference/android/view/KeyEvent.html">http://developer.android.com/reference/android/view/KeyEvent.html</a></p> 5583 5584<p>89. Android Open Source sensors: <a href="http://source.android.com/devices/sensors/">http://source.android.com/devices/sensors</a></p> 5585 5586<p>90. android.hardware.SensorEvent: <a href="http://developer.android.com/reference/android/hardware/SensorEvent.html">http://developer.android.com/reference/android/hardware/SensorEvent.html</a></p> 5587 5588<p>91. Timestamp sensor event: <a href="http://developer.android.com/reference/android/hardware/SensorEvent.html#timestamp">http://developer.android.com/reference/android/hardware/SensorEvent.html#timestamp</a></p> 5589 5590<p>92. Android Open Source composite sensors: <a href="http://source.android.com/devices/sensors/sensor-types.html#composite_sensor_type_summary">https://source.android.com/devices/sensors/sensor-types.html#composite_sensor_type_summary</a></p> 5591 5592<p>93. Continuous trigger mode: <a href="http://source.android.com/devices/sensors/report-modes.html#continuous">https://source.android.com/devices/sensors/report-modes.html#continuous</a></p> 5593 5594<p>94. Accelerometer sensor: <a href="http://developer.android.com/reference/android/hardware/Sensor.html#TYPE_ACCELEROMETER">http://developer.android.com/reference/android/hardware/Sensor.html#TYPE_ACCELEROMETER</a></p> 5595 5596<p>95. Android Fingerprint API: <a href="https://developer.android.com/reference/android/hardware/fingerprint/package-summary.html">https://developer.android.com/reference/android/hardware/fingerprint/package-summary.html</a></p> 5597 5598<p>96. Android Fingerprint HAL: <a href="https://source.android.com/devices/tech/security/authentication/fingerprint-hal.html">https://source.android.com/devices/tech/security/authentication/fingerprint-hal.html</a></p> 5599 5600<p>97. Wi-Fi Multicast API: <a href="http://developer.android.com/reference/android/net/wifi/WifiManager.MulticastLock.html">http://developer.android.com/reference/android/net/wifi/WifiManager.MulticastLock.html</a></p> 5601 5602<p>98. Wi-Fi Direct (Wi-Fi P2P): <a href="http://developer.android.com/reference/android/net/wifi/p2p/WifiP2pManager.html">http://developer.android.com/reference/android/net/wifi/p2p/WifiP2pManager.html</a></p> 5603 5604<p>99. WifiManager API: <a href="http://developer.android.com/reference/android/net/wifi/WifiManager.html">http://developer.android.com/reference/android/net/wifi/WifiManager.html</a></p> 5605 5606<p>100. Bluetooth API: <a href="http://developer.android.com/reference/android/bluetooth/package-summary.html">http://developer.android.com/reference/android/bluetooth/package-summary.html</a></p> 5607 5608<p>101. Bluetooth ScanFilter API: <a href="https://developer.android.com/reference/android/bluetooth/le/ScanFilter.html">https://developer.android.com/reference/android/bluetooth/le/ScanFilter.html</a></p> 5609 5610<p>102. NFC Barcode: <a href="http://developer.android.com/reference/android/nfc/tech/NfcBarcode.html">http://developer.android.com/reference/android/nfc/tech/NfcBarcode.html</a></p> 5611 5612<p>103. NDEF Push Protocol: <a href="http://source.android.com/compatibility/ndef-push-protocol.pdf">http://source.android.com/compatibility/ndef-push-protocol.pdf</a></p> 5613 5614<p>104. Android Beam: <a href="http://developer.android.com/guide/topics/connectivity/nfc/nfc.html">http://developer.android.com/guide/topics/connectivity/nfc/nfc.html</a></p> 5615 5616<p>105. Android NFC Sharing Settings: <a href="http://developer.android.com/reference/android/provider/Settings.html#ACTION_NFCSHARING_SETTINGS">http://developer.android.com/reference/android/provider/Settings.html#ACTION_NFCSHARING_SETTINGS</a></p> 5617 5618<p>106. NFC Connection Handover: <a href="http://members.nfc-forum.org/specs/spec_list/#conn_handover">http://members.nfc-forum.org/specs/spec_list/#conn_handover</a></p> 5619 5620<p>107. Bluetooth Secure Simple Pairing Using NFC: <a href="http://members.nfc-forum.org/apps/group_public/download.php/18688/NFCForum-AD-BTSSP_1_1.pdf">http://members.nfc-forum.org/apps/group_public/download.php/18688/NFCForum-AD-BTSSP_1_1.pdf</a></p> 5621 5622<p>108. Host-based Card Emulation: <a href="http://developer.android.com/guide/topics/connectivity/nfc/hce.html">http://developer.android.com/guide/topics/connectivity/nfc/hce.html</a></p> 5623 5624<p>109. Content Resolver: <a href="http://developer.android.com/reference/android/content/ContentResolver.html">http://developer.android.com/reference/android/content/ContentResolver.html</a></p> 5625 5626<p>110. Camera orientation API: <a href="http://developer.android.com/reference/android/hardware/Camera.html#setDisplayOrientation(int)">http://developer.android.com/reference/android/hardware/Camera.html#setDisplayOrientation(int)</a></p> 5627 5628<p>111. Camera: <a href="http://developer.android.com/reference/android/hardware/Camera.html">http://developer.android.com/reference/android/hardware/Camera.html</a></p> 5629 5630<p>112. Camera: <a href="http://developer.android.com/reference/android/hardware/Camera.Parameters.html">http://developer.android.com/reference/android/hardware/Camera.Parameters.html</a></p> 5631 5632<p>113. Camera hardware level: <a href="https://developer.android.com/reference/android/hardware/camera2/CameraCharacteristics.html#INFO_SUPPORTED_HARDWARE_LEVEL">https://developer.android.com/reference/android/hardware/camera2/CameraCharacteristics.html#INFO_SUPPORTED_HARDWARE_LEVEL</a></p> 5633 5634<p>114. Camera version support: <a href="http://source.android.com/devices/camera/versioning.html">http://source.android.com/devices/camera/versioning.html</a></p> 5635 5636<p>115. Android DownloadManager: <a href="http://developer.android.com/reference/android/app/DownloadManager.html">http://developer.android.com/reference/android/app/DownloadManager.html</a></p> 5637 5638<p>116. Android File Transfer: <a href="http://www.android.com/filetransfer">http://www.android.com/filetransfer</a></p> 5639 5640<p>117. Adoptable storage: <a href="http://source.android.com/devices/storage/adoptable.html">http://source.android.com/devices/storage/adoptable.html</a></p> 5641 5642<p>118. Android Open Accessories: <a href="http://developer.android.com/guide/topics/connectivity/usb/accessory.html">http://developer.android.com/guide/topics/connectivity/usb/accessory.html</a></p> 5643 5644<p>119. Android USB Audio: <a href="http://developer.android.com/reference/android/hardware/usb/UsbConstants.html#USB_CLASS_AUDIO">http://developer.android.com/reference/android/hardware/usb/UsbConstants.html#USB_CLASS_AUDIO</a></p> 5645 5646<p>120. USB Battery Charging Specification, Revision 1.2: <a href="http://www.usb.org/developers/docs/devclass_docs/BCv1.2_070312.zip">http://www.usb.org/developers/docs/devclass_docs/BCv1.2_070312.zip</a></p> 5647 5648<p>121. USB Host API:<a href="http://developer.android.com/guide/topics/connectivity/usb/host.html"> http://developer.android.com/guide/topics/connectivity/usb/host.html</a></p> 5649 5650<p>122. Wired audio headset: <a href="http://source.android.com/accessories/headset-spec.html">http://source.android.com/accessories/headset-spec.html</a></p> 5651 5652<p>123. Power profile components: <a href="http://source.android.com/devices/tech/power/values.html">http://source.android.com/devices/tech/power/values.html</a></p> 5653 5654<p>124. Batterystats: <a href="http://source.android.com/devices/tech/power/batterystats.html">http://source.android.com/devices/tech/power/batterystats.html</a></p> 5655 5656<p>125. Power usage summary: <a href="http://developer.android.com/reference/android/content/Intent.html#ACTION_POWER_USAGE_SUMMARY">http://developer.android.com/reference/android/content/Intent.html#ACTION_POWER_USAGE_SUMMARY</a></p> 5657 5658<p>126. Android Security and Permissions reference: <a href="http://developer.android.com/guide/topics/security/permissions.html">http://developer.android.com/guide/topics/security/permissions.html</a></p> 5659 5660<p>127. UserManager reference: <a href="http://developer.android.com/reference/android/os/UserManager.html">http://developer.android.com/reference/android/os/UserManager.html</a></p> 5661 5662<p>128. External Storage reference: <a href="http://source.android.com/devices/storage/traditional.html">http://source.android.com/devices/storage</a></p> 5663 5664<p>129. External Storage APIs: <a href="http://developer.android.com/reference/android/os/Environment.html">http://developer.android.com/reference/android/os/Environment.html</a></p> 5665 5666<p>130. SMS Short Code: <a href="http://en.wikipedia.org/wiki/Short_code">http://en.wikipedia.org/wiki/Short_code</a></p> 5667 5668<p>131. Secure lock screen reporting: <a href="http://developer.android.com/reference/android/app/KeyguardManager.html#isDeviceSecure()">http://developer.android.com/reference/android/app/KeyguardManager.html#isDeviceSecure()</a></p> 5669 5670<p>132. Android Open Source Encryption: <a href="http://source.android.com/devices/tech/security/encryption/index.html">http://source.android.com/devices/tech/security/encryption/index.html</a></p> 5671 5672<p>133. Android Keystore System: <a href="https://developer.android.com/training/articles/keystore.html">https://developer.android.com/training/articles/keystore.html</a></p> 5673 5674<p>134. KeyChain API: <a href="https://developer.android.com/reference/android/security/KeyChain.html">https://developer.android.com/reference/android/security/KeyChain.html</a></p> 5675 5676<p>135. Keystore API: <a href="https://developer.android.com/reference/java/security/KeyStore.html">https://developer.android.com/reference/java/security/KeyStore.html</a></p> 5677 5678<p>136. Gatekeeper HAL: <a href="http://source.android.com/devices/tech/security/authentication/gatekeeper.html">http://source.android.com/devices/tech/security/authentication/gatekeeper.html</a></p> 5679 5680<p>137. Android Compatibility Program Overview: <a href="http://source.android.com/compatibility/index.html">http://source.android.com/compatibility/index.html</a></p> 5681 5682<p>138. SystemUpdatePolicy class: <a href="http://developer.android.com/reference/android/app/admin/SystemUpdatePolicy.html">http://developer.android.com/reference/android/app/admin/SystemUpdatePolicy.html</a></p> 5683 5684<p>139. Android Compatibility forum: <a href="https://groups.google.com/forum/#!forum/android-compatibility">https://groups.google.com/forum/#!forum/android-compatibility</a></p> 5685 5686<p>140. Handling app links: <a href="https://developer.android.com/training/app-links">https://developer.android.com/training/app-links/index.html</a></p> 5687 5688<p>141. Google Digital Asset Links: <a href="https://developers.google.com/digital-asset-links">https://developers.google.com/digital-asset-links</a></p> 5689 5690<p>Many of these resources are derived directly or indirectly from the Android 5691SDK, and will be functionally identical to the information in that SDK’s 5692documentation. In any cases where this Compatibility Definition or the 5693Compatibility Test Suite disagrees with the SDK documentation, the SDK 5694documentation is considered authoritative. Any technical details provided in 5695the references included above are considered by inclusion to be part of this 5696Compatibility Definition.</p> 5697 5698</div> 5699</body> 5700</html> 5701
