1<!DOCTYPE html> 2<head> 3<title>Android 5.1 Compatibility Definition</title> 4<link rel="stylesheet" type="text/css" href="android-cdd.css"/> 5</head> 6 7<body> 8 9<h6>Table of Contents</h6> 10 11<div id="toc"> 12 13<div id="toc_left"> 14 15<p class="toc_h1"><a href="#1_introduction">1. Introduction</a></p> 16 17<p class="toc_h1"><a href="#2_device_types">2. Device Types</a></p> 18 19<p class="toc_h2"><a href="#2_1_device_configurations">2.1 Device Configurations</a></p> 20 21<p class="toc_h1"><a href="#3_software">3. Software</a></p> 22 23<p class="toc_h2"><a href="#3_1_managed_api_compatibility">3.1. Managed API Compatibility</a></p> 24 25<p class="toc_h2"><a href="#3_2_soft_api_compatibility">3.2. Soft API Compatibility</a></p> 26 27<p class="toc_h3"><a href="#3_2_1_permissions">3.2.1. Permissions</a></p> 28 29<p class="toc_h3"><a href="#3_2_2_build_parameters">3.2.2. Build Parameters</a></p> 30 31<p class="toc_h3"><a href="#3_2_3_intent_compatibility">3.2.3. Intent Compatibility</a></p> 32 33<p class="toc_h4"><a href="#3_2_3_1_core_application_intents">3.2.3.1. Core Application Intents</a></p> 34 35<p class="toc_h4"><a href="#3_2_3_2_intent_overrides">3.2.3.2. Intent Overrides</a></p> 36 37<p class="toc_h4"><a href="#3_2_3_3_intent_namespaces">3.2.3.3. Intent Namespaces</a></p> 38 39<p class="toc_h4"><a href="#3_2_3_4_broadcast_intents">3.2.3.4. Broadcast Intents</a></p> 40 41<p class="toc_h4"><a href="#3_2_3_5_default_app_settings">3.2.3.5. Default App Settings</a></p> 42 43<p class="toc_h2"><a href="#3_3_native_api_compatibility">3.3. Native API Compatibility</a></p> 44 45<p class="toc_h3"><a href="#3_3_1_application_binary_interfaces">3.3.1. Application Binary Interfaces</a></p> 46 47<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> 48 49<p class="toc_h2"><a href="#3_4_web_compatibility">3.4. Web Compatibility</a></p> 50 51<p class="toc_h3"><a href="#3_4_1_webview_compatibility">3.4.1. WebView Compatibility</a></p> 52 53<p class="toc_h3"><a href="#3_4_2_browser_compatibility">3.4.2. Browser Compatibility</a></p> 54 55<p class="toc_h2"><a href="#3_5_api_behavioral_compatibility">3.5. API Behavioral Compatibility</a></p> 56 57<p class="toc_h2"><a href="#3_6_api_namespaces">3.6. API Namespaces</a></p> 58 59<p class="toc_h2"><a href="#3_7_runtime_compatibility">3.7. Runtime Compatibility</a></p> 60 61<p class="toc_h2"><a href="#3_8_user_interface_compatibility">3.8. User Interface Compatibility</a></p> 62 63<p class="toc_h3"><a href="#3_8_1_launcher_home_screen">3.8.1. Launcher (Home Screen)</a></p> 64 65<p class="toc_h3"><a href="#3_8_2_widgets">3.8.2. Widgets</a></p> 66 67<p class="toc_h3"><a href="#3_8_3_notifications">3.8.3. Notifications</a></p> 68 69<p class="toc_h3"><a href="#3_8_4_search">3.8.4. Search</a></p> 70 71<p class="toc_h3"><a href="#3_8_5_toasts">3.8.5. Toasts</a></p> 72 73<p class="toc_h3"><a href="#3_8_6_themes">3.8.6. Themes</a></p> 74 75<p class="toc_h3"><a href="#3_8_7_live_wallpapers">3.8.7. Live Wallpapers</a></p> 76 77<p class="toc_h3"><a href="#3_8_8_activity_switching">3.8.8. Activity Switching</a></p> 78 79<p class="toc_h3"><a href="#3_8_9_input_management">3.8.9. Input Management</a></p> 80 81<p class="toc_h3"><a href="#3_8_10_lock_screen_media_control">3.8.10. Lock Screen Media Control</a></p> 82 83<p class="toc_h3"><a href="#3_8_11_dreams">3.8.11. Dreams</a></p> 84 85<p class="toc_h3"><a href="#3_8_12_location">3.8.12. Location</a></p> 86 87<p class="toc_h3"><a href="#3_8_13_unicode_and_font">3.8.13. Unicode and Font</a></p> 88 89 90 91</div> 92 93<div id="toc_right"><br> 94 95 96 97<p class="toc_h2"><a href="#3_9_device_administration">3.9. Device Administration</a></p> 98 99<p class="toc_h2"><a href="#3_10_accessibility">3.10. Accessibility</a></p> 100 101<p class="toc_h2"><a href="#3_11_text-to-speech">3.11. Text-to-Speech</a></p> 102 103<p class="toc_h2"><a href="#3_12_tv_input_framework">3.12. TV Input Framework</a></p> 104 105<p class="toc_h1"><a href="#4_application_packaging_compatibility">4. Application Packaging Compatibility</a></p> 106 107<p class="toc_h1"><a href="#5_multimedia_compatibility">5. Multimedia Compatibility</a></p> 108 109<p class="toc_h2"><a href="#5_1_media_codecs">5.1. Media Codecs</a></p> 110 111<p class="toc_h3"><a href="#5_1_1_audio_codecs">5.1.1. Audio Codecs</a></p> 112 113<p class="toc_h3"><a href="#5_1_2_image_codecs">5.1.2. Image Codecs</a></p> 114 115<p class="toc_h3"><a href="#5_1_3_video_codecs">5.1.3. Video Codecs</a></p> 116 117<p class="toc_h2"><a href="#5_2_video_encoding">5.2. Video Encoding</a></p> 118 119<p class="toc_h2"><a href="#5_3_video_decoding">5.3. Video Decoding</a></p> 120 121<p class="toc_h2"><a href="#5_4_audio_recording">5.4. Audio Recording</a></p> 122 123<p class="toc_h3"><a href="#5_4_1_raw_audio_capture">5.4.1. Raw Audio Capture</a></p> 124 125<p class="toc_h3"><a href="#5_4_2_capture_for_voice_recognition">5.4.2. Capture for Voice Recognition</a></p> 126 127<p class="toc_h3"><a href="#5_4_3_capture_for_rerouting_of_playback">5.4.3. Capture for Rerouting of Playback</a></p> 128 129<p class="toc_h2"><a href="#5_5_audio_playback">5.5. Audio Playback</a></p> 130 131<p class="toc_h3"><a href="#5_5_1_raw_audio_playback">5.5.1. Raw Audio Playback</a></p> 132 133<p class="toc_h3"><a href="#5_5_2_audio_effects">5.5.2. Audio Effects</a></p> 134 135<p class="toc_h3"><a href="#5_5_3_audio_output_volume">5.5.3. Audio Output Volume</a></p> 136 137<p class="toc_h2"><a href="#5_6_audio_latency">5.6. Audio Latency</a></p> 138 139<p class="toc_h2"><a href="#5_7_network_protocols">5.7. Network Protocols</a></p> 140 141<p class="toc_h2"><a href="#5_8_secure_media">5.8. Secure Media</a></p> 142 143<p class="toc_h1"><a href="#6_developer_tools_and_options_compatibility">6. Developer Tools and Options Compatibility</a></p> 144 145<p class="toc_h2"><a href="#6_1_developer_tools">6.1. Developer Tools</a></p> 146 147<p class="toc_h2"><a href="#6_2_developer_options">6.2. Developer Options</a></p> 148 149<p class="toc_h1"><a href="#7_hardware_compatibility">7. Hardware Compatibility</a></p> 150 151<p class="toc_h2"><a href="#7_1_display_and_graphics">7.1. Display and Graphics</a></p> 152 153<p class="toc_h3"><a href="#7_1_1_screen_configuration">7.1.1. Screen Configuration</a></p> 154 155<p class="toc_h4"><a href="#7_1_1_1_screen_size">7.1.1.1. Screen Size</a></p> 156 157<p class="toc_h4"><a href="#7_1_1_2_screen_aspect_ratio">7.1.1.2. Screen Aspect Ratio</a></p> 158 159<p class="toc_h4"><a href="#7_1_1_3_screen_density">7.1.1.3. Screen Density</a></p> 160 161 162</div> 163 164<div style="clear: both; page-break-after:always; height:1px"></div> 165 166 167<div id="toc_left_2"> 168 169<p class="toc_h3"><a href="#7_1_2_display_metrics">7.1.2. Display Metrics</a></p> 170 171<p class="toc_h3"><a href="#7_1_3_screen_orientation">7.1.3. Screen Orientation</a></p> 172 173<p class="toc_h3"><a href="#7_1_4_2d_and_3d_graphics_acceleration">7.1.4. 2D and 3D Graphics Acceleration</a></p> 174 175<p class="toc_h3"><a href="#7_1_5_legacy_application_compatibility_mode">7.1.5. Legacy Application Compatibility Mode</a></p> 176 177<p class="toc_h3"><a href="#7_1_6_screen_technology">7.1.6. Screen Technology</a></p> 178 179<p class="toc_h3"><a href="#7_1_7_external_displays">7.1.7. Secondary Displays</a></p> 180 181<p class="toc_h2"><a href="#7_2_input_devices">7.2. Input Devices</a></p> 182 183<p class="toc_h3"><a href="#7_2_1_keyboard">7.2.1. Keyboard</a></p> 184 185<p class="toc_h3"><a href="#7_2_2_non-touch_navigation">7.2.2. Non-touch Navigation</a></p> 186 187<p class="toc_h3"><a href="#7_2_3_navigation_keys">7.2.3. Navigation Keys</a></p> 188 189<p class="toc_h3"><a href="#7_2_4_touchscreen_input">7.2.4. Touchscreen Input</a></p> 190 191<p class="toc_h3"><a href="#7_2_5_fake_touch_input">7.2.5. Fake Touch Input</a></p> 192 193<p class="toc_h3"><a href="#7_2_6_game_controller_support">7.2.6. Game Controller Support</a></p> 194 195<p class="toc_h4"><a href="#7_2_6_1_button_mapping">7.2.6.1. Button Mappings</a></p> 196 197<p class="toc_h3"><a href="#7_2_7_remote_control">7.2.7. Remote Control</a></p> 198 199<p class="toc_h2"><a href="#7_3_sensors">7.3. Sensors</a></p> 200 201<p class="toc_h3"><a href="#7_3_1_accelerometer">7.3.1. Accelerometer</a></p> 202 203<p class="toc_h3"><a href="#7_3_2_magnetometer">7.3.2. Magnetometer</a></p> 204 205<p class="toc_h3"><a href="#7_3_3_gps">7.3.3. GPS</a></p> 206 207<p class="toc_h3"><a href="#7_3_4_gyroscope">7.3.4. Gyroscope</a></p> 208 209<p class="toc_h3"><a href="#7_3_5_barometer">7.3.5. Barometer</a></p> 210 211<p class="toc_h3"><a href="#7_3_6_thermometer">7.3.6. Thermometer</a></p> 212 213<p class="toc_h3"><a href="#7_3_7_photometer">7.3.7. Photometer</a></p> 214 215<p class="toc_h3"><a href="#7_3_8_proximity_sensor">7.3.8. Proximity Sensor</a></p> 216 217<p class="toc_h2"><a href="#7_4_data_connectivity">7.4. Data Connectivity</a></p> 218 219<p class="toc_h3"><a href="#7_4_1_telephony">7.4.1. Telephony</a></p> 220 221<p class="toc_h3"><a href="#7_4_2_ieee_80211_wi-fi">7.4.2. IEEE 802.11 (Wi-Fi)</a></p> 222 223<p class="toc_h4"><a href="#7_4_2_1_wi-fi_direct">7.4.2.1. Wi-Fi Direct</a></p> 224 225<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> 226 227<p class="toc_h3"><a href="#7_4_3_bluetooth">7.4.3. Bluetooth</a></p> 228 229<p class="toc_h3"><a href="#7_4_4_near-field_communications">7.4.4. Near-Field Communications</a></p> 230 231<p class="toc_h3"><a href="#7_4_5_minimum_network_capability">7.4.5. Minimum Network Capability</a></p> 232 233<p class="toc_h3"><a href="#7_4_6_sync_settings">7.4.6. Sync Settings</a></p> 234 235<p class="toc_h2"><a href="#7_5_cameras">7.5. Cameras</a></p> 236 237<p class="toc_h3"><a href="#7_5_1_rear-facing_camera">7.5.1. Rear-Facing Camera</a></p> 238 239<p class="toc_h3"><a href="#7_5_2_front-facing_camera">7.5.2. Front-Facing Camera</a></p> 240 241<p class="toc_h3"><a href="#7_5_3_external_camera">7.5.3. External Camera</a></p> 242 243<p class="toc_h3"><a href="#7_5_4_camera_api_behavior">7.5.4. Camera API Behavior</a></p> 244 245 246 247 248 249</div> 250 251<div id="toc_right_2"> 252 253<p class="toc_h3"><a href="#7_5_5_camera_orientation">7.5.5. Camera Orientation</a></p> 254 255<p class="toc_h2"><a href="#7_6_memory_and_storage">7.6. Memory and Storage</a></p> 256 257<p class="toc_h3"><a href="#7_6_1_minimum_memory_and_storage">7.6.1. Minimum Memory and Storage</a></p> 258 259<p class="toc_h3"><a href="#7_6_2_application_shared_storage">7.6.2. Application Shared Storage</a></p> 260 261<p class="toc_h2"><a href="#7_7_usb">7.7. USB</a></p> 262 263<p class="toc_h2"><a href="#7_8_audio">7.8. Audio</a></p> 264 265<p class="toc_h3"><a href="#7_8_1_microphone">7.8.1. Microphone</a></p> 266 267<p class="toc_h3"><a href="#7_8_2_audio_output">7.8.2. Audio Output</a></p> 268 269<p class="toc_h4"><a href="#7_8_2_1_analog_audio_ports">7.8.2.1. Analog Audio Ports</a></p> 270 271<p class="toc_h1"><a href="#8_performance_compatibility">8. Performance Compatibility</a></p> 272 273<p class="toc_h2"><a href="#8_1_user_experience_consistency">8.1. User Experience Consistency</a></p> 274 275<p class="toc_h2"><a href="#8_2_memory_performance">8.2. Memory Performance</a></p> 276 277<p class="toc_h1"><a href="#9_security_model_compatibility">9. Security Model Compatibility</a></p> 278 279<p class="toc_h2"><a href="#9_1_permissions">9.1. Permissions</a></p> 280 281<p class="toc_h2"><a href="#9_2_uid_and_process_isolation">9.2. UID and Process Isolation</a></p> 282 283<p class="toc_h2"><a href="#9_3_filesystem_permissions">9.3. Filesystem Permissions</a></p> 284 285<p class="toc_h2"><a href="#9_4_alternate_execution_environments">9.4. Alternate Execution Environments</a></p> 286 287<p class="toc_h2"><a href="#9_5_multi-user_support">9.5. Multi-User Support</a></p> 288 289<p class="toc_h2"><a href="#9_6_premium_sms_warning">9.6. Premium SMS Warning</a></p> 290 291<p class="toc_h2"><a href="#9_7_kernel_security_features">9.7. Kernel Security Features</a></p> 292 293<p class="toc_h2"><a href="#9_8_privacy">9.8. Privacy</a></p> 294 295<p class="toc_h2"><a href="#9_9_full-disk-encryption">9.9. Full-Disk Encryption</a></p> 296 297<p class="toc_h2"><a href="#9_10_verified_boot">9.10. Verified Boot</a></p> 298 299<p class="toc_h1"><a href="#10_software_compatibility_testing">10. Software Compatibility Testing</a></p> 300 301<p class="toc_h2"><a href="#10_1_compatibility_test_suite">10.1. Compatibility Test Suite</a></p> 302 303<p class="toc_h2"><a href="#10_2_cts_verifier">10.2. CTS Verifier</a></p> 304 305<p class="toc_h1"><a href="#11_updatable_software">11. Updatable Software</a></p> 306 307<p class="toc_h1"><a href="#12_document_changelog">12. Document Changelog</a></p> 308 309<p class="toc_h1"><a href="#13_contact_us">13. Contact Us</a></p> 310 311<p class="toc_h1"><a href="#14_resources">14. Resources</a></p> 312 313</div> 314 315</div> 316 317<div style="clear: both"></div> 318 319<div id="main"> 320 321<h1 id="1_introduction">1. Introduction</h1> 322 323 324<p>This document enumerates the requirements that must be met in order for devices 325to be compatible with Android 5.1.</p> 326 327<p>The use of “MUST”, “MUST NOT”, “REQUIRED”, “SHALL”, “SHALL NOT”, “SHOULD”,“SHOULD NOT”, “RECOMMENDED”, “MAY”, and “OPTIONAL” is per the IETF standard 328defined in RFC2119 [<a href="http://www.ietf.org/rfc/rfc2119.txt">Resources, 1</a>].</p> 329 330<p>As used in this document, a “device implementer” or “implementer” is a person 331or organization developing a hardware/software solution running Android 5.1. A 332“device implementation” or “implementation is the hardware/software solution 333so developed.</p> 334 335<p>To be considered compatible with Android 5.1, device implementations MUST meet 336the requirements presented in this Compatibility Definition, including any 337documents incorporated via reference.</p> 338 339<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 340implementer to ensure compatibility with existing implementations.</p> 341 342<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 343implementers are strongly encouraged to base their implementations to the 344greatest extent possible on the “upstream” source code available from the 345Android Open Source Project. While some components can hypothetically be 346replaced with alternate implementations this practice is strongly discouraged, 347as passing the software tests will become substantially more difficult. It is 348the implementer’s responsibility to ensure full behavioral compatibility with 349the standard Android implementation, including and beyond the Compatibility 350Test Suite. Finally, note that certain component substitutions and 351modifications are explicitly forbidden by this document.</p> 352 353<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 354functionally identical to the information in that SDK’s documentation. For any 355case where this Compatibility Definition or the Compatibility Test Suite 356disagrees with the SDK documentation, the SDK documentation is considered 357authoritative. 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> 358 359<h1 id="2_device_types">2. Device Types</h1> 360 361 362<p>While the Android Open Source Project has been used in the implementation of a 363variety of device types and form factors, many aspects of the architecture and 364compatibility requirements were optimized for handheld devices. Starting from 365Android 5.0, the Android Open Source Project aims to embrace a wider variety of 366device types as described in this section.</p> 367 368<p><strong>Android Handheld device</strong> refers to an Android device implementation that is typically used by holding 369it in the hand, such as mp3 players, phones, and tablets. Android Handheld 370device implementations:</p> 371 372<ul> 373 <li>MUST have a touchscreen embedded in the device.</li> 374 <li>MUST have a power source that provides mobility, such as a battery.</li> 375</ul> 376 377<p><strong>Android Television device</strong> refers to an Android device implementation that is an entertainment interface 378for consuming digital media, movies, games, apps, and/or live TV for users 379sitting about ten feet away (a “lean back” or “10-foot user interface”). 380Android Television devices:</p> 381 382<ul> 383 <li>MUST have an embedded screen OR include a video output port, such as VGA, HDMI, 384or a wireless port for display.</li> 385 <li>MUST declare the features android.software.leanback and 386android.hardware.type.television [<a href="http://developer.android.com/reference/android/content/pm/PackageManager.html#FEATURE_LEANBACK">Resources, 3</a>].</li> 387</ul> 388 389<p><strong>Android Watch device</strong> refers to an Android device implementation intended to be worn on the body, 390perhaps on the wrist, and:</p> 391 392<ul> 393 <li>MUST have a screen with the physical diagonal length in the range from 1.1 to 3942.5 inches.</li> 395 <li>MUST declare the feature android.hardware.type.watch.</li> 396 <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> 397</ul> 398 399<p><strong>Android Automotive implementation</strong> refers to a vehicle head 400unit running Android as an operating system for part or all of the system and/or 401infotainment functionality. Android Automotive implementations MUST support 402uiMode = UI_MODE_TYPE_CAR [<a href="http://developer.android.com/reference/android/content/res/Configuration.html#UI_MODE_TYPE_CAR">Resources, 111</a>].</p> 403 404<p>All Android device implementations that do not fit into any of the above device 405types still MUST meet all requirements in this document to be Android 5.1 406compatible, unless the requirement is explicitly described to be only 407applicable to a specific Android device type from above.</p> 408 409<h2 id="2_1_device_configurations">2.1 Device Configurations</h2> 410 411 412<p>This is a summary of major differences in hardware configuration by device 413type. (Empty cells denote a “MAY”). Not all configurations are covered in this 414table; see relevant hardware sections for more detail.</p> 415<table> 416 <tr> 417 <th>Category</th> 418 <th>Feature</th> 419 <th>Section</th> 420 <th>Handheld</th> 421 <th>Television</th> 422 <th>Watch</th> 423 <th>Automotive</th> 424 <th>Other</th> 425 </tr> 426 <tr> 427 <td rowspan="3">Input</td> 428 <td>D-pad</td> 429 <td><a href="#7_2_2_non-touch-navigation">7.2.2. Non-touch Navigation</a></td> 430 <td></td> 431 <td>MUST</td> 432 <td></td> 433 <td></td> 434 <td></td> 435 </tr> 436 <tr> 437 <td>Touchscreen </td> 438 <td><a href="#7_2_4_touchscreen_input">7.2.4. Touchscreen input</a></td> 439 <td>MUST</td> 440 <td></td> 441 <td>MUST</td> 442 <td></td> 443 <td>SHOULD</td> 444 </tr> 445 <tr> 446 <td>Microphone </td> 447 <td><a href="#7_8_1_microphone">7.8.1. Microphone</a></td> 448 <td>MUST</td> 449 <td>SHOULD </td> 450 <td>MUST</td> 451 <td>MUST</td> 452 <td>SHOULD</td> 453 </tr> 454 <tr> 455 <td rowspan="2">Sensors</td> 456 <td>Accelerometer </td> 457 <td><a href="#7_3_1_accelerometer">7.3.1 Accelerometer</a></td> 458 <td>SHOULD</td> 459 <td></td> 460 <td>SHOULD</td> 461 <td></td> 462 <td>SHOULD</td> 463 </tr> 464 <tr> 465 <td>GPS</td> 466 <td><a href="#7_3_3_gps">7.3.3. GPS</a></td> 467 <td>SHOULD</td> 468 <td></td> 469 <td></td> 470 <td>SHOULD</td> 471 <td></td> 472 </tr> 473 <tr> 474 <td rowspan="5">Connectivity</td> 475 <td>Wi-Fi</td> 476 <td><a href="#7_4_2_ieee_802.11">7.4.2. IEEE 802.11</a></td> 477 <td>SHOULD</td> 478 <td> MUST</td> 479 <td></td> 480 <td>SHOULD</td> 481 <td>SHOULD</td> 482 </tr> 483 <tr> 484 <td>Wi-Fi Direct</td> 485 <td><a href="#7_4_2_1_wi-fi-direct">7.4.2.1. Wi-Fi Direct</a></td> 486 <td>SHOULD</td> 487 <td>SHOULD</td> 488 <td></td> 489 <td></td> 490 <td>SHOULD</td> 491 </tr> 492 <tr> 493 <td>Bluetooth</td> 494 <td><a href="#7_4_3_bluetooth">7.4.3. Bluetooth</a></td> 495 <td>SHOULD</td> 496 <td>MUST</td> 497 <td>MUST</td> 498 <td>MUST</td> 499 <td>SHOULD</td> 500 </tr> 501 <tr> 502 <td>Bluetooth Low Energy</td> 503 <td><a href="#7_4_3_bluetooth">7.4.3. Bluetooth</a></td> 504 <td>SHOULD</td> 505 <td>MUST</td> 506 <td>SHOULD</td> 507 <td>SHOULD</td> 508 <td>SHOULD</td> 509 </tr> 510 <tr> 511 <td>USB peripheral/host mode</td> 512 <td><a href="#7_7_usb">7.7. USB</a></td> 513 <td>SHOULD</td> 514 <td></td> 515 <td></td> 516 <td>SHOULD</td> 517 <td>SHOULD</td> 518 </tr> 519 <tr> 520 <td>Output</td> 521 <td>Speaker and/or Audio output ports</td> 522 <td><a href="#7_8_2_audio_output">7.8.2. Audio Output</a></td> 523 <td>MUST</td> 524 <td>MUST</td> 525 <td></td> 526 <td>MUST</td> 527 <td>MUST</td> 528 </tr> 529</table> 530 531 532<h1 id="3_software">3. Software</h1> 533 534 535<h2 id="3_1_managed_api_compatibility">3.1. Managed API Compatibility</h2> 536 537 538<p>The managed Dalvik bytecode execution environment is the primary vehicle for 539Android applications. The Android application programming interface (API) is 540the set of Android platform interfaces exposed to applications running in the 541managed runtime environment. Device implementations MUST provide complete 542implementations, including all documented behaviors, of any documented API 543exposed by the Android SDK [<a href="http://developer.android.com/reference/packages.html">Resources, 5</a>] or any API decorated with the “@SystemApi” marker in the upstream Android 544source code. </p> 545 546<p>Device implementations MUST NOT omit any managed APIs, alter API interfaces or 547signatures, deviate from the documented behavior, or include no-ops, except 548where specifically allowed by this Compatibility Definition.</p> 549 550<p>This Compatibility Definition permits some types of hardware for which Android 551includes APIs to be omitted by device implementations. In such cases, the APIs 552MUST 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> 553 554<h2 id="3_2_soft_api_compatibility">3.2. Soft API Compatibility</h2> 555 556 557<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 558such things as intents, permissions, and similar aspects of Android 559applications that cannot be enforced at application compile time.</p> 560 561<h3 id="3_2_1_permissions">3.2.1. Permissions</h3> 562 563 564<p>Device implementers MUST support and enforce all permission constants as 565documented by the Permission reference page [<a href="http://developer.android.com/reference/android/Manifest.permission.html">Resources, 6]</a>. Note that <a href="#9_security_model_compatibility">section 9</a> lists additional requirements related to the Android security model.</p> 566 567<h3 id="3_2_2_build_parameters">3.2.2. Build Parameters</h3> 568 569 570<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, 7</a>] that are intended to describe the current device. To provide consistent, 571meaningful values across device implementations, the table below includes 572additional restrictions on the formats of these values to which device 573implementations MUST conform.</p> 574<table> 575 <tr> 576 <th>Parameter</th> 577 <th>Details</th> 578 </tr> 579 <tr> 580 <td>VERSION.RELEASE</td> 581 <td>The version of the currently-executing Android system, in human-readable 582format. This field MUST have one of the string values defined in [<a href="http://source.android.com/compatibility/5.1/versions.html">Resources, 8]</a>.</td> 583 </tr> 584 <tr> 585 <td>VERSION.SDK</td> 586 <td>The version of the currently-executing Android system, in a format accessible 587to third-party application code. For Android 5.1, this field MUST have the 588integer value 22.</td> 589 </tr> 590 <tr> 591 <td>VERSION.SDK_INT</td> 592 <td>The version of the currently-executing Android system, in a format accessible 593to third-party application code. For Android 5.1, this field MUST have the 594integer value 22.</td> 595 </tr> 596 <tr> 597 <td>VERSION.INCREMENTAL</td> 598 <td>A value chosen by the device implementer designating the specific build of the 599currently-executing Android system, in human-readable format. This value MUST 600NOT be reused for different builds made available to end users. A typical use 601of this field is to indicate which build number or source-control change 602identifier was used to generate the build. There are no requirements on the 603specific format of this field, except that it MUST NOT be null or the empty 604string ("").</td> 605 </tr> 606 <tr> 607 <td>BOARD</td> 608 <td>A value chosen by the device implementer identifying the specific internal 609hardware used by the device, in human-readable format. A possible use of this 610field is to indicate the specific revision of the board powering the device. 611The value of this field MUST be encodable as 7-bit ASCII and match the regular 612expression “^[a-zA-Z0-9_-]+$”.</td> 613 </tr> 614 <tr> 615 <td>BRAND</td> 616 <td>A value reflecting the brand name associated with the device as known to the 617end users. MUST be in human-readable format and SHOULD represent the 618manufacturer of the device or the company brand under which the device is 619marketed. The value of this field MUST be encodable as 7-bit ASCII and match 620the regular expression “^[a-zA-Z0-9_-]+$”.</td> 621 </tr> 622 <tr> 623 <td>SUPPORTED_ABIS</td> 624 <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> 625 </tr> 626 <tr> 627 <td>SUPPORTED_32_BIT_ABIS</td> 628 <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> 629 </tr> 630 <tr> 631 <td>SUPPORTED_64_BIT_ABIS</td> 632 <td>The name of the second instruction set (CPU type + ABI convention) of native 633code. See <a href="#3_3_native_api_compatibility">section 3.3. Native API Compatibility</a>.</td> 634 </tr> 635 <tr> 636 <td>CPU_ABI</td> 637 <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> 638 </tr> 639 <tr> 640 <td>CPU_ABI2</td> 641 <td>The name of the second instruction set (CPU type + ABI convention) of native 642code. See <a href="#3_3_native_api_compatibility">section 3.3. Native API Compatibility</a>.</td> 643 </tr> 644 <tr> 645 <td>DEVICE</td> 646 <td>A value chosen by the device implementer containing the development name or 647code name identifying the configuration of the hardware features and industrial 648design of the device. The value of this field MUST be encodable as 7-bit ASCII 649and match the regular expression “^[a-zA-Z0-9_-]+$”.</td> 650 </tr> 651 <tr> 652 <td>FINGERPRINT</td> 653 <td>A string that uniquely identifies this build. It SHOULD be reasonably 654human-readable. It MUST follow this template:</p> 655 656<p class="small">$(BRAND)/$(PRODUCT)/$(DEVICE):$(VERSION.RELEASE)/$(ID)/$(VERSION.INCREMENTAL):$(TYPE)/$(TAGS)</p> 657 658<p>For example: acme/myproduct/mydevice:5.1/LMYXX/3359:userdebug/test-keys</p> 659 660<p>The fingerprint MUST NOT include whitespace characters. If other fields 661included in the template above have whitespace characters, they MUST be 662replaced in the build fingerprint with another character, such as the 663underscore ("_") character. The value of this field MUST be encodable as 7-bit 664ASCII.</td> 665 </tr> 666 <tr> 667 <td>HARDWARE</td> 668 <td>The name of the hardware (from the kernel command line or /proc). It SHOULD be 669reasonably human-readable. The value of this field MUST be encodable as 7-bit 670ASCII and match the regular expression “^[a-zA-Z0-9_-]+$”. </td> 671 </tr> 672 <tr> 673 <td>HOST</td> 674 <td>A string that uniquely identifies the host the build was built on, in 675human-readable format. There are no requirements on the specific format of this 676field, except that it MUST NOT be null or the empty string ("").</td> 677 </tr> 678 <tr> 679 <td>ID</td> 680 <td>An identifier chosen by the device implementer to refer to a specific release, 681in human-readable format. This field can be the same as 682android.os.Build.VERSION.INCREMENTAL, but SHOULD be a value sufficiently 683meaningful for end users to distinguish between software builds. The value of 684this field MUST be encodable as 7-bit ASCII and match the regular expression “^[a-zA-Z0-9._-]+$”.</td> 685 </tr> 686 <tr> 687 <td>MANUFACTURER</td> 688 <td>The trade name of the Original Equipment Manufacturer (OEM) of the product. 689There are no requirements on the specific format of this field, except that it 690MUST NOT be null or the empty string ("").</td> 691 </tr> 692 <tr> 693 <td>MODEL</td> 694 <td>A value chosen by the device implementer containing the name of the device as 695known to the end user. This SHOULD be the same name under which the device is 696marketed and sold to end users. There are no requirements on the specific 697format of this field, except that it MUST NOT be null or the empty string ("").</td> 698 </tr> 699 <tr> 700 <td>PRODUCT</td> 701 <td>A value chosen by the device implementer containing the development name or 702code name of the specific product (SKU) that MUST be unique within the same 703brand. MUST be human-readable, but is not necessarily intended for view by end 704users. The value of this field MUST be encodable as 7-bit ASCII and match the 705regular expression “^[a-zA-Z0-9_-]+$”.</td> 706 </tr> 707 <tr> 708 <td>SERIAL</td> 709 <td>A hardware serial number, which MUST be available. The value of this field MUST 710be encodable as 7-bit ASCII and match the regular expression “^([a-zA-Z0-9]{6,20})$”.</td> 711 </tr> 712 <tr> 713 <td>TAGS</td> 714 <td>A comma-separated list of tags chosen by the device implementer that further 715distinguishes the build. This field MUST have one of the values corresponding 716to the three typical Android platform signing configurations: release-keys, 717dev-keys, test-keys. </td> 718 </tr> 719 <tr> 720 <td>TIME</td> 721 <td>A value representing the timestamp of when the build occurred.</td> 722 </tr> 723 <tr> 724 <td>TYPE</td> 725 <td>A value chosen by the device implementer specifying the runtime configuration 726of the build. This field MUST have one of the values corresponding to the three 727typical Android runtime configurations: user, userdebug, or eng.</td> 728 </tr> 729 <tr> 730 <td>USER</td> 731 <td>A name or user ID of the user (or automated user) that generated the build. 732There are no requirements on the specific format of this field, except that it 733MUST NOT be null or the empty string ("").</td> 734 </tr> 735</table> 736 737 738<h3 id="3_2_3_intent_compatibility">3.2.3. Intent Compatibility</h3> 739 740 741<p>Device implementations MUST honor Android’s loose-coupling intent system, as 742described in the sections below. By“honored ” it is meant that the device 743implementer MUST provide an Android Activity or Service that specifies a 744matching intent filter that binds to and implements correct behavior for each 745specified intent pattern.</p> 746 747<h4 id="3_2_3_1_core_application_intents">3.2.3.1. Core Application Intents</h4> 748 749 750<p>Android intents allow application components to request functionality from 751other Android components. The Android upstream project includes a list of 752applications considered core Android applications, which implements several 753intent patterns to perform common actions. The core Android applications are:</p> 754 755<ul> 756 <li>Desk Clock</li> 757 <li>Browser</li> 758 <li>Calendar</li> 759 <li>Contacts</li> 760 <li>Gallery</li> 761 <li>GlobalSearch</li> 762 <li>Launcher</li> 763 <li>Music</li> 764 <li>Settings</li> 765</ul> 766 767<p>Device implementations SHOULD include the core Android applications as 768appropriate but MUST include a component implementing the same intent patterns 769defined by all the “public” Activity or Service components of these core 770Android applications. Note that Activity or Service components are considered 771“public” when the attribute android:exported is absent or has the value true.</p> 772 773<h4 id="3_2_3_2_intent_overrides">3.2.3.2. Intent Overrides</h4> 774 775 776<p>As Android is an extensible platform, device implementations MUST allow each 777intent pattern referenced in <a href="#3_2_3_1_core_application_intents">section 3.2.3.1</a> to be overridden by third-party applications. The upstream Android open source 778implementation allows this by default; device implementers MUST NOT attach 779special privileges to system applications' use of these intent patterns, or 780prevent third-party applications from binding to and assuming control of these 781patterns. This prohibition specifically includes but is not limited to 782disabling the“Chooser” user interface that allows the user to select between 783multiple applications that all handle the same intent pattern.</p> 784 785<p>However, device implementations MAY provide default activities for specific URI 786patterns (eg. http://play.google.com) if the default activity provides a more 787specific filter for the data URI. For example, an intent filter specifying the 788data URI “http://www.android.com” is more specific than the browser filter for“http://”. Device implementations MUST provide a user interface for users to 789modify the default activity for intents.</p> 790 791<h4 id="3_2_3_3_intent_namespaces">3.2.3.3. Intent Namespaces</h4> 792 793 794<p>Device implementations MUST NOT include any Android component that honors any 795new intent or broadcast intent patterns using an ACTION, CATEGORY, or other key 796string in the android.* or com.android.* namespace. Device implementers MUST 797NOT include any Android components that honor any new intent or broadcast 798intent patterns using an ACTION, CATEGORY, or other key string in a package 799space belonging to another organization. Device implementers MUST NOT alter or 800extend 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 801and obviously associated with their own organization. This prohibition is 802analogous to that specified for Java language classes in <a href="#3_6_api_namespaces">section 3.6</a>.</p> 803 804<h4 id="3_2_3_4_broadcast_intents">3.2.3.4. Broadcast Intents</h4> 805 806 807<p>Third-party applications rely on the platform to broadcast certain intents to 808notify them of changes in the hardware or software environment. 809Android-compatible devices MUST broadcast the public broadcast intents in 810response to appropriate system events. Broadcast intents are described in the 811SDK documentation.</p> 812 813<h4 id="3_2_3_5_default_app_settings">3.2.3.5. Default App Settings</h4> 814 815 816<p>Android includes settings that provide users an easy way to select their 817default applications, for example for Home screen or SMS. Where it makes sense, 818device implementations MUST provide a similar settings menu and be compatible 819with the intent filter pattern and API methods described in the SDK 820documentation as below.</p> 821 822<p>Device implementations:</p> 823 824<ul> 825 <li>MUST honor the android.settings.HOME_SETTINGS intent to show a default app 826settings menu for Home Screen, if the device implementation reports 827android.software.home_screen [<a href="http://developer.android.com/reference/android/provider/Settings.html">Resources, 10]</a></li> 828 <li>MUST provide a settings menu that will call the 829android.provider.Telephony.ACTION_CHANGE_DEFAULT intent to show a dialog to 830change the default SMS application, if the device implementation reports 831android.hardware.telephony [<a href="http://developer.android.com/reference/android/provider/Telephony.Sms.Intents.html">Resources, 9</a>]</li> 832 <li>MUST honor the android.settings.NFC_PAYMENT_SETTINGS intent to show a default 833app settings menu for Tap and Pay, if the device implementation reports 834android.hardware.nfc.hce [<a href="http://developer.android.com/reference/android/provider/Settings.html">Resources, 10]</a></li> 835</ul> 836 837<h2 id="3_3_native_api_compatibility">3.3. Native API Compatibility</h2> 838 839 840<h3 id="3_3_1_application_binary_interfaces">3.3.1. Application Binary Interfaces</h3> 841 842 843<p>Managed Dalvik bytecode can call into native code provided in the application 844.apk file as an ELF .so file compiled for the appropriate device hardware 845architecture. As native code is highly dependent on the underlying processor 846technology, Android defines a number of Application Binary Interfaces (ABIs) in 847the Android NDK. Device implementations MUST be compatible with one or more 848defined ABIs, and MUST implement compatibility with the Android NDK, as below.</p> 849 850<p>If a device implementation includes support for an Android ABI, it:</p> 851 852<ul> 853 <li>MUST include support for code running in the managed environment to call into 854native code, using the standard Java Native Interface (JNI) semantics</li> 855 <li>MUST be source-compatible (i.e. header compatible) and binary-compatible (for 856the ABI) with each required library in the list below</li> 857 <li>MUST support the equivalent 32-bit ABI if any 64-bit ABI is supported</li> 858 <li>MUST accurately report the native Application Binary Interface (ABI) supported 859by the device, via the android.os.Build.SUPPORTED_ABIS, 860android.os.Build.SUPPORTED_32_BIT_ABIS, and 861android.os.Build.SUPPORTED_64_BIT_ABIS parameters, each a comma separated list 862of ABIs ordered from the most to the least preferred one</li> 863 <li>MUST report, via the above parameters, only those ABIs documented in the latest 864version of the Android NDK, “NDK Programmer’s Guide | ABI Management” in docs/ 865directory</li> 866 <li>SHOULD be built using the source code and header files available in the 867upstream Android Open Source Project</li> 868</ul> 869 870<p>The following native code APIs MUST be available to apps that include native 871code:</p> 872 873<ul> 874 <li>libc (C library)</li> 875 <li>libm (math library)</li> 876 <li>Minimal support for C++</li> 877 <li>JNI interface</li> 878 <li>liblog (Android logging)</li> 879 <li>libz (Zlib compression)</li> 880 <li>libdl (dynamic linker)</li> 881 <li>libGLESv1_CM.so (OpenGL ES 1.x)</li> 882 <li>libGLESv2.so (OpenGL ES 2.0)</li> 883 <li>libGLESv3.so (OpenGL ES 3.x)</li> 884 <li>libEGL.so (native OpenGL surface management)</li> 885 <li>libjnigraphics.so</li> 886 <li>libOpenSLES.so (OpenSL ES 1.0.1 audio support)</li> 887 <li>libOpenMAXAL.so (OpenMAX AL 1.0.1 support)</li> 888 <li>libandroid.so (native Android activity support)</li> 889 <li>libmediandk.so (native media APIs support)</li> 890 <li>Support for OpenGL, as described below</li> 891</ul> 892 893<p>Note that future releases of the Android NDK may introduce support for 894additional ABIs. If a device implementation is not compatible with an existing 895predefined ABI, it MUST NOT report support for any ABIs at all.</p> 896 897<p>Note that device implementations MUST include libGLESv3.so and it MUST symlink 898(symbolic link) to libGLESv2.so. in turn, MUST export all the OpenGL ES 3.1 and 899Android Extension Pack [<a href="http://developer.android.com/guide/topics/graphics/opengl.html#aep">Resources, 11</a>] function symbols as defined in the NDK release android-21. Although all the 900symbols must be present, only the corresponding functions for OpenGL ES 901versions and extensions actually supported by the device must be fully 902implemented.</p> 903 904<p>Native code compatibility is challenging. For this reason, device implementers 905are <strong>very strongly encouraged</strong> to use the implementations of the libraries listed above from the upstream 906Android Open Source Project. </p> 907 908<h3 id="3_3_2_32-bit_arm_native_code_compatibility"> 9093.3.2. 32-bit ARM Native Code Compatibility 910</h3> 911 912<p>The ARMv8 architecture deprecates several CPU operations, including some 913operations used in existing native code. On 64-bit ARM devices, the following 914deprecated operations MUST remain available to 32-bit native ARM code, either 915through native CPU support or through software emulation:</p> 916 917<ul> 918<li>SWP and SWPB instructions</li> 919<li>SETEND instruction</li> 920<li>CP15ISB, CP15DSB, and CP15DMB barrier operations</li> 921</ul> 922 923<p>Legacy versions of the Android NDK used /proc/cpuinfo to discover CPU features 924from 32-bit ARM native code. For compatibility with applications built using this 925NDK, devices MUST include the following lines in /proc/cpuinfo when it is read 926by 32-bit ARM applications:</p> 927 928<ul> 929<li>"Features: ", followed by a list of any optional ARMv7 CPU features 930supported by the device</li> 931<li>"CPU architecture: ", followed by an integer describing the device's 932highest supported ARM architecture (e.g., "8" for ARMv8 devices)</li> 933</ul> 934 935<p>These requirements only apply when /proc/cpuinfo is read by 32-bit ARM 936applications. Devices SHOULD not alter /proc/cpuinfo when read by 64-bit ARM or 937non-ARM applications.</p> 938 939<h2 id="3_4_web_compatibility">3.4. Web Compatibility</h2> 940 941 942<h3 id="3_4_1_webview_compatibility">3.4.1. WebView Compatibility</h3> 943 944<div class="note"> 945<p>Android Watch devices MAY, but all other device implementations MUST provide 946a complete implementation of the android.webkit.Webview API.</p> 947</div> 948 949 950<p>The platform feature android.software.webview MUST be reported on any device 951that provides a complete implementation of the android.webkit.WebView API, and 952MUST NOT be reported on devices without a complete implementation of the API. 953The Android Open Source implementation uses code from the Chromium Project to 954implement the android.webkit.WebView [<a href="http://developer.android.com/reference/android/webkit/WebView.html">Resources, 12</a>]. Because it is not feasible to develop a comprehensive test suite for a web 955rendering system, device implementers MUST use the specific upstream build of 956Chromium in the WebView implementation. Specifically:</p> 957 958<ul> 959 <li>Device android.webkit.WebView implementations MUST be based on the Chromium 960build from the upstream Android Open Source Project for Android 5.1. This build 961includes a specific set of functionality and security fixes for the WebView [<a href="http://www.chromium.org/">Resources, 13</a>].</li> 962 <li>The user agent string reported by the WebView MUST be in this format: 963<p>Mozilla/5.0 (Linux; Android $(VERSION); $(MODEL) Build/$(BUILD)$(WEBVIEW)) 964AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 $(CHROMIUM_VER) Mobile 965Safari/537.36</p> 966 <ul> 967 <li>The value of the $(VERSION) string MUST be the same as the value for 968android.os.Build.VERSION.RELEASE.</li> 969 <li>The $(WEBVIEW) string MAY be omitted, but if included MUST be "; wv" to 970 note that this is a webview</li> 971 <li>The value of the $(MODEL) string MUST be the same as the value for 972android.os.Build.MODEL.</li> 973 <li>The value of the $(BUILD) string MUST be the same as the value for 974android.os.Build.ID.</li> 975 <li>The value of the $(CHROMIUM_VER) string MUST be the version of Chromium in the 976upstream Android Open Source Project.</li> 977 <li>Device implementations MAY omit Mobile in the user agent string.</li> 978 </ul></li></ul> 979 980<p>The WebView component SHOULD include support for as many HTML5 features as 981possible and if it supports the feature SHOULD conform to the HTML5 982specification [<a href="http://html.spec.whatwg.org/multipage/">Resources, 14</a>].</p> 983 984<h3 id="3_4_2_browser_compatibility">3.4.2. Browser Compatibility</h3> 985 986<div class="note"> 987<p>Android Television, Watch, and Android Automotive implementations MAY omit a 988browser application, but MUST support the public intent patterns as described in 989<a href="#3_2_3_1_core_application_intents">section 3.2.3.1</a>. All other types 990of device implementations MUST include a standalone Browser application for 991general user web browsing.</p> 992</div> 993 994<p>The standalone Browser MAY be based on a browser technology other than WebKit. 995However, even if an alternate Browser application is used, the 996android.webkit.WebView component provided to third-party applications MUST be 997based on WebKit, as described in <a href="#3_4_1_webview_compatibility">section 3.4.1</a>.</p> 998 999<p>Implementations MAY ship a custom user agent string in the standalone Browser 1000application.</p> 1001 1002<p>The standalone Browser application (whether based on the upstream WebKit 1003Browser application or a third-party replacement) SHOULD include support for as 1004much of HTML5 [<a href="http://html.spec.whatwg.org/multipage/">Resources, 14</a>] as possible. Minimally, device implementations MUST support each of these 1005APIs associated with HTML5:</p> 1006 1007<ul> 1008 <li>application cache/offline operation [<a href="http://www.w3.org/html/wg/drafts/html/master/browsers.html#offline">Resources, 15</a>]</li> 1009 <li>the <video> tag [<a href="http://www.w3.org/html/wg/drafts/html/master/semantics.html#video">Resources, 16</a>]</li> 1010 <li>geolocation [<a href="http://www.w3.org/TR/geolocation-API/">Resources, 17</a>]</li> 1011</ul> 1012 1013<p>Additionally, device implementations MUST support the HTML5/W3C webstorage API 1014[<a href="http://www.w3.org/TR/webstorage/">Resources, 18</a>], and SHOULD support the HTML5/W3C IndexedDB API [<a href="http://www.w3.org/TR/IndexedDB/">Resources, 19</a>]. Note that as the web development standards bodies are transitioning to favor 1015IndexedDB over webstorage, IndexedDB is expected to become a required component 1016in a future version of Android.</p> 1017 1018<h2 id="3_5_api_behavioral_compatibility">3.5. API Behavioral Compatibility</h2> 1019 1020 1021<p>The behaviors of each of the API types (managed, soft, native, and web) must be 1022consistent with the preferred implementation of the upstream Android Open 1023Source Project [<a href="http://source.android.com/">Resources, 2</a>]. Some specific areas of compatibility are:</p> 1024 1025<ul> 1026 <li>Devices MUST NOT change the behavior or semantics of a standard intent.</li> 1027 <li>Devices MUST NOT alter the lifecycle or lifecycle semantics of a particular 1028type of system component (such as Service, Activity, ContentProvider, etc.).</li> 1029 <li>Devices MUST NOT change the semantics of a standard permission.</li> 1030</ul> 1031 1032<p>The above list is not comprehensive. The Compatibility Test Suite (CTS) tests 1033significant portions of the platform for behavioral compatibility, but not all. 1034It is the responsibility of the implementer to ensure behavioral compatibility 1035with the Android Open Source Project. For this reason, device implementers 1036SHOULD use the source code available via the Android Open Source Project where 1037possible, rather than re-implement significant parts of the system.</p> 1038 1039<h2 id="3_6_api_namespaces">3.6. API Namespaces</h2> 1040 1041 1042<p>Android follows the package and class namespace conventions defined by the Java 1043programming language. To ensure compatibility with third-party applications, 1044device implementers MUST NOT make any prohibited modifications (see below) to 1045these package namespaces:</p> 1046 1047<ul> 1048 <li>java.*</li> 1049 <li>javax.*</li> 1050 <li>sun.*</li> 1051 <li>android.*</li> 1052 <li>com.android.*</li> 1053</ul> 1054 1055<p><strong>Prohibited modifications include</strong>:</p> 1056 1057<ul> 1058 <li>Device implementations MUST NOT modify the publicly exposed APIs on the Android 1059platform by changing any method or class signatures, or by removing classes or 1060class fields.</li> 1061 <li>Device implementers MAY modify the underlying implementation of the APIs, but 1062such modifications MUST NOT impact the stated behavior and Java-language 1063signature of any publicly exposed APIs.</li> 1064 <li>Device implementers MUST NOT add any publicly exposed elements (such as classes 1065or interfaces, or fields or methods to existing classes or interfaces) to the 1066APIs above.</li> 1067</ul> 1068 1069<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, 1070device implementers MUST NOT expose new APIs or alter existing APIs in the 1071namespaces noted above. Device implementers MAY make internal-only 1072modifications, but those modifications MUST NOT be advertised or otherwise 1073exposed to developers.</p> 1074 1075<p>Device implementers MAY add custom APIs, but any such APIs MUST NOT be in a 1076namespace owned by or referring to another organization. For instance, device 1077implementers MUST NOT add APIs to the com.google.* or similar namespace: only 1078Google may do so. Similarly, Google MUST NOT add APIs to other companies' 1079namespaces. Additionally, if a device implementation includes custom APIs 1080outside the standard Android namespace, those APIs MUST be packaged in an 1081Android shared library so that only apps that explicitly use them (via the 1082<uses-library> mechanism) are affected by the increased memory usage of such 1083APIs.</p> 1084 1085<p>If a device implementer proposes to improve one of the package namespaces above 1086(such as by adding useful new functionality to an existing API, or adding a new 1087API), 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 1088information on that site.</p> 1089 1090<p>Note that the restrictions above correspond to standard conventions for naming 1091APIs in the Java programming language; this section simply aims to reinforce 1092those conventions and make them binding through inclusion in this Compatibility 1093Definition.</p> 1094 1095<h2 id="3_7_runtime_compatibility">3.7. Runtime Compatibility</h2> 1096 1097 1098<p>Device implementations MUST support the full Dalvik Executable (DEX) format and 1099Dalvik bytecode specification and semantics [<a href="https://android.googlesource.com/platform/dalvik/+/lollipop-release/docs/">Resources, 20</a>]. Device implementers SHOULD use ART, the reference upstream implementation of 1100the Dalvik Executable Format, and the reference implementation’s package 1101management system.</p> 1102 1103<p>Device implementations MUST configure Dalvik runtimes to allocate memory in 1104accordance with the upstream Android platform, and as specified by the 1105following table. (See <a href="#7_1_1_screen_configuration">section 7.1.1</a> for screen size and screen density definitions.)</p> 1106 1107<p>Note that memory values specified below are considered minimum values and 1108device implementations MAY allocate more memory per application.</p> 1109 1110<table> 1111 <tr> 1112 <th>Screen Layout</th> 1113 <th>Screen Density</th> 1114 <th>Minimum Application Memory</th> 1115 </tr> 1116 <tr> 1117 <td rowspan="10">small/normal</td> 1118 <td>120 dpi (ldpi)</td> 1119 <td rowspan="2">32MB</td> 1120 </tr> 1121 <tr> 1122 <td>160 dpi (mdpi)</td> 1123 </tr> 1124 <tr> 1125 <td>213 dpi (tvdpi)</td> 1126 <td rowspan="3">48MB</td> 1127 </tr> 1128 <tr> 1129 <td>240 dpi (hdpi)</td> 1130 </tr> 1131 <tr> 1132 <td>280 dpi (280dpi)</td> 1133 </tr> 1134 <tr> 1135 <td>320 dpi (xhdpi)</td> 1136 <td>80MB</td> 1137 </tr> 1138 <tr> 1139 <td>400 dpi (400dpi)</td> 1140 <td>96MB</td> 1141 </tr> 1142 <tr> 1143 <td>480 dpi (xxhdpi)</td> 1144 <td>128MB</td> 1145 </tr> 1146 <tr> 1147 <td>560 dpi (560dpi)</td> 1148 <td>192MB</td> 1149 </tr> 1150 <tr> 1151 <td>640 dpi (xxxhdpi)</td> 1152 <td>256MB</td> 1153 </tr> 1154 <tr> 1155 <td rowspan="10">large</td> 1156 <td>120 dpi (ldpi)</td> 1157 <td>32MB</td> 1158 </tr> 1159 <tr> 1160 <td>160 dpi (mdpi)</td> 1161 <td>48MB</td> 1162 </tr> 1163 <tr> 1164 <td>213 dpi (tvdpi)</td> 1165 <td rowspan="2">80MB</td> 1166 </tr> 1167 <tr> 1168 <td>240 dpi (hdpi)</td> 1169 </tr> 1170 <tr> 1171 <td>280 dpi (280dpi)</td> 1172 <td>96MB</td> 1173 </tr> 1174 <tr> 1175 <td>320 dpi (xhdpi)</td> 1176 <td>128MB</td> 1177 </tr> 1178 <tr> 1179 <td>400 dpi (400dpi)</td> 1180 <td>192MB</td> 1181 </tr> 1182 <tr> 1183 <td>480 dpi (xxhdpi)</td> 1184 <td>256MB</td> 1185 </tr> 1186 <tr> 1187 <td>560 dpi (560dpi)</td> 1188 <td>384MB</td> 1189 </tr> 1190 <tr> 1191 <td>640 dpi (xxxhdpi)</td> 1192 <td>512MB</td> 1193 </tr> 1194 <tr> 1195 <td rowspan="10">xlarge</td> 1196 <td>120 dpi (ldpi)</td> 1197 <td>48MB</td> 1198 </tr> 1199 <tr> 1200 <td>160 dpi (mdpi)</td> 1201 <td>80MB</td> 1202 </tr> 1203 <tr> 1204 <td>213 dpi (tvdpi)</td> 1205 <td rowspan="2">96MB</td> 1206 </tr> 1207 <tr> 1208 <td>240 dpi (hdpi)</td> 1209 </tr> 1210 <tr> 1211 <td>280 dpi (280dpi)</td> 1212 <td>144MB</td> 1213 </tr> 1214 <tr> 1215 <td>320 dpi (xhdpi)</td> 1216 <td>192MB</td> 1217 </tr> 1218 <tr> 1219 <td>400 dpi (400dpi)</td> 1220 <td>288MB</td> 1221 </tr> 1222 <tr> 1223 <td>480 dpi (xxhdpi)</td> 1224 <td>384MB</td> 1225 </tr> 1226 <tr> 1227 <td>560 dpi (560dpi)</td> 1228 <td>576MB</td> 1229 </tr> 1230 <tr> 1231 <td>640 dpi (xxxhdpi)</td> 1232 <td>768MB</td> 1233 </tr> 1234</table> 1235 1236 1237<h2 id="3_8_user_interface_compatibility">3.8. User Interface Compatibility</h2> 1238 1239 1240<h3 id="3_8_1_launcher_home_screen">3.8.1. Launcher (Home Screen)</h3> 1241 1242 1243<p>Android includes a launcher application (home screen) and support for 1244third-party applications to replace the device launcher (home screen). Device 1245implementations that allow third-party applications to replace the device home 1246screen MUST declare the platform feature android.software.home_screen.</p> 1247 1248<h3 id="3_8_2_widgets">3.8.2. Widgets</h3> 1249 1250<div class="note"> 1251<p>Widgets are optional for all Android device implementations, but SHOULD be 1252supported on Android Handheld devices.</p> 1253</div> 1254 1255 1256<p>Android defines a component type and corresponding API and lifecycle that 1257allows applications to expose an “AppWidget” to the end user [<a href="http://developer.android.com/guide/practices/ui_guidelines/widget_design.html">Resources, 21</a>] a feature that is strongly RECOMMENDED to be supported on Handheld Device 1258implementations. Device implementations that support embedding widgets on the 1259home screen MUST meet the following requirements and declare support for 1260platform feature android.software.app_widgets.</p> 1261 1262<ul> 1263 <li>Device launchers MUST include built-in support for AppWidgets, and expose user 1264interface affordances to add, configure, view, and remove AppWidgets directly 1265within the Launcher.</li> 1266 <li>Device implementations MUST be capable of rendering widgets that are 4 x 4 in 1267the standard grid size. See the App Widget Design Guidelines in the Android SDK 1268documentation [<a href="http://developer.android.com/guide/practices/ui_guidelines/widget_design.html">Resources, 21</a>] for details.</li> 1269 <li>Device implementations that include support for lock screen MAY support 1270application widgets on the lock screen.</li> 1271</ul> 1272 1273<h3 id="3_8_3_notifications">3.8.3. Notifications</h3> 1274 1275 1276<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, 22</a>], using hardware and software features of the device.</p> 1277 1278<p>Some APIs allow applications to perform notifications or attract attention 1279using hardware—specifically sound, vibration, and light. Device implementations 1280MUST support notifications that use hardware features, as described in the SDK 1281documentation, and to the extent possible with the device implementation 1282hardware. For instance, if a device implementation includes a vibrator, it MUST 1283correctly implement the vibration APIs. If a device implementation lacks 1284hardware, the corresponding APIs MUST be implemented as no-ops. This behavior 1285is further detailed in <a href="#7_hardware_compatibility">section 7</a>.</p> 1286 1287<p>Additionally, the implementation MUST correctly render all resources (icons, animation files 1288etc.) provided for in the APIs 1289[<a href="https://developer.android.com/guide/topics/resources/available-resources.html">Resources, 23</a>], 1290or in the Status/System Bar icon style guide 1291[<a href="http://developer.android.com/design/style/iconography.html">Resources, 24</a>], 1292which in the case of an Android Television device includes the possibility to not display the 1293notifications. Device implementers MAY provide an alternative user experience for 1294notifications than that provided by the reference Android Open Source 1295implementation; however, such alternative notification systems MUST support 1296existing notification resources, as above. </p> 1297 1298<p>Android includes support for various notifications, such as:</p> 1299 1300<ul> 1301 <li><strong>Rich notifications</strong>. Interactive Views for ongoing notifications.</li> 1302 <li><strong>Heads-up notifications</strong>. Interactive Views users can act on or dismiss without leaving the current app.</li> 1303 <li><strong>Lockscreen notifications</strong>. Notifications shown over a lock screen with granular control on visibility.</li> 1304</ul> 1305 1306<p>Android device implementations, when such notifications are made visible, MUST properly execute 1307Rich and Heads-up notifications and include the title/name, icon, text as documented in the Android 1308APIs <a href="https://developer.android.com/design/patterns/notifications.html">[Resources, 25]</a>. 1309</p> 1310 1311<p>Android includes Notification Listener Service APIs that allow apps (once 1312explicitly enabled by the user) to receive a copy of all notifications as they 1313are posted or updated. Device implementations MUST correctly and promptly send 1314notifications in their entirety to all such installed and user-enabled listener 1315services, including any and all metadata attached to the Notification object.</p> 1316 1317<h3 id="3_8_4_search">3.8.4. Search</h3> 1318 1319 1320<p>Android includes APIs [<a href="http://developer.android.com/reference/android/app/SearchManager.html">Resources, 26</a>] that allow developers to incorporate search into their applications, and 1321expose their application’s data into the global system search. Generally 1322speaking, this functionality consists of a single, system-wide user interface 1323that allows users to enter queries, displays suggestions as users type, and 1324displays results. The Android APIs allow developers to reuse this interface to 1325provide search within their own apps, and allow developers to supply results to 1326the common global search user interface.</p> 1327 1328<p>Android device implementations SHOULD include global search, a single, shared, 1329system-wide search user interface capable of real-time suggestions in response 1330to user input. Device implementations SHOULD implement the APIs that allow 1331developers to reuse this user interface to provide search within their own 1332applications. Device implementations that implement the global search interface 1333MUST implement the APIs that allow third-party applications to add suggestions 1334to the search box when it is run in global search mode. If no third-party 1335applications are installed that make use of this functionality, the default 1336behavior SHOULD be to display web search engine results and suggestions.</p> 1337 1338<h3 id="3_8_5_toasts">3.8.5. Toasts</h3> 1339 1340 1341<p>Applications can use the “Toast” API to display short non-modal strings to the 1342end user, that disappear after a brief period of time [<a href="http://developer.android.com/reference/android/widget/Toast.html">Resources, 27</a>]. Device implementations MUST display Toasts from applications to end users in 1343some high-visibility manner.</p> 1344 1345<h3 id="3_8_6_themes">3.8.6. Themes</h3> 1346 1347 1348<p>Android provides “themes” as a mechanism for applications to apply styles 1349across an entire Activity or application.</p> 1350 1351<p>Android includes a “Holo” theme family as a set of defined styles for 1352application developers to use if they want to match the Holo theme look and 1353feel as defined by the Android SDK [<a href="http://developer.android.com/guide/topics/ui/themes.html">Resources, 28</a>]. Device implementations MUST NOT alter any of the Holo theme attributes 1354exposed to applications [<a href="http://developer.android.com/reference/android/R.style.html">Resources, 29</a>].</p> 1355 1356<p>Android includes a “Material” theme family as a set of defined styles for 1357application developers to use if they want to match the design theme’s look and 1358feel across the wide variety of different Android device types. Device 1359implementations MUST support the “Material” theme family and MUST NOT alter any 1360of the Material theme attributes or their assets exposed to applications [<a href="http://developer.android.com/reference/android/R.style.html#Theme_Material">Resources, 30</a>].</p> 1361 1362<p>Android also includes a “Device Default” theme family as a set of defined 1363styles for application developers to use if they want to match the look and 1364feel of the device theme as defined by the device implementer. Device 1365implementations MAY modify the Device Default theme attributes exposed to 1366applications [<a href="http://developer.android.com/reference/android/R.style.html">Resources, 29</a>].</p> 1367 1368<p>Android supports a new variant theme with translucent system bars, which allows 1369application developers to fill the area behind the status and navigation bar 1370with their app content. To enable a consistent developer experience in this 1371configuration, it is important the status bar icon style is maintained across 1372different device implementations. Therefore, Android device implementations 1373MUST use white for system status icons (such as signal strength and battery 1374level) and notifications issued by the system, unless the icon is indicating a 1375problematic status [<a href="http://developer.android.com/reference/android/R.style.html">Resources, 29</a>].</p> 1376 1377<h3 id="3_8_7_live_wallpapers">3.8.7. Live Wallpapers</h3> 1378 1379 1380<p>Android defines a component type and corresponding API and lifecycle that 1381allows 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, 31</a>]. Live wallpapers are animations, patterns, or similar images with limited 1382input capabilities that display as a wallpaper, behind other applications.</p> 1383 1384<p>Hardware is considered capable of reliably running live wallpapers if it can 1385run all live wallpapers, with no limitations on functionality, at a reasonable 1386frame rate with no adverse effects on other applications. If limitations in the 1387hardware cause wallpapers and/or applications to crash, malfunction, consume 1388excessive CPU or battery power, or run at unacceptably low frame rates, the 1389hardware is considered incapable of running live wallpaper. As an example, some 1390live wallpapers may use an OpenGL 2.0 or 3.x context to render their content. 1391Live wallpaper will not run reliably on hardware that does not support multiple 1392OpenGL contexts because the live wallpaper use of an OpenGL context may 1393conflict with other applications that also use an OpenGL context.</p> 1394 1395<p>Device implementations capable of running live wallpapers reliably as described 1396above SHOULD implement live wallpapers, and when implemented MUST report the 1397platform feature flag android.software.live_wallpaper.</p> 1398 1399<h3 id="3_8_8_activity_switching">3.8.8. Activity Switching</h3> 1400 1401<div class="note"> 1402<p>As the Recent function navigation key is OPTIONAL, the requirements to 1403implement the overview screen is OPTIONAL for Android Television devices and 1404Android Watch devices.</p> 1405</div> 1406 1407 1408<p>The upstream Android source code includes the overview screen [<a href="http://developer.android.com/guide/components/recents.html">Resources, 32</a>], a system-level user interface for task switching and displaying recently 1409accessed activities and tasks using a thumbnail image of the application’s 1410graphical state at the moment the user last left the application. Device 1411implementations 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> 1412 1413<ul> 1414 <li>MUST display affiliated recents as a group that moves together.</li> 1415 <li>MUST support at least up to 20 displayed activities.</li> 1416 <li>MUST at least display the title of 4 activities at a time.</li> 1417 <li>SHOULD display highlight color, icon, screen title in recents.</li> 1418 <li>MUST implement the screen pinning behavior [<a href="http://developer.android.com/about/versions/android-5.0.html#ScreenPinning">Resources, 33</a>] and provide the user with a settings menu to toggle the feature.</li> 1419 <li>SHOULD display a closing affordance ("x") but MAY delay this until user 1420interacts with screens.</li> 1421</ul> 1422 1423<p>Device implementations are STRONGLY ENCOURAGED to use the upstream Android user 1424interface (or a similar thumbnail-based interface) for the overview screen.</p> 1425 1426<h3 id="3_8_9_input_management">3.8.9. Input Management</h3> 1427 1428 1429<p>Android includes support for Input Management and support for third-party input 1430method editors [<a href="http://developer.android.com/guide/topics/text/creating-input-method.html">Resources, 34</a>]. Device implementations that allow users to use third-party input methods on 1431the device MUST declare the platform feature android.software.input_methods and 1432support IME APIs as defined in the Android SDK documentation.</p> 1433 1434<p>Device implementations that declare the android.software.input_methods feature 1435MUST provide a user-accessible mechanism to add and configure third-party input 1436methods. Device implementations MUST display the settings interface in response 1437to the android.settings.INPUT_METHOD_SETTINGS intent.</p> 1438 1439<h3 id="3_8_10_lock_screen_media_control">3.8.10. Lock Screen Media Control</h3> 1440 1441 1442<p>The Remote Control Client API is deprecated from Android 5.0 in favor of the 1443Media Notification Template that allows media applications to integrate with 1444playback controls that are displayed on the lock screen [<a href="http://developer.android.com/reference/android/app/Notification.MediaStyle.html">Resources, 35</a>]. 1445Device implementations that support a lock screen, unless an Android Automotive or Watch 1446implementation, MUST display the Lockscreen Notifications including the Media Notification 1447Template.</p> 1448 1449<h3 id="3_8_11_dreams">3.8.11. Dreams</h3> 1450 1451 1452<p>Android includes support for interactive screensavers called Dreams [<a href="http://developer.android.com/reference/android/service/dreams/DreamService.html">Resources, 36</a>]. Dreams allows users to interact with applications when a device connected to 1453a power source is idle or docked in a desk dock. Android Watch devices MAY 1454implement Dreams, but other types of device implementations SHOULD include 1455support for Dreams and provide a settings option for users to configure Dreams 1456in response to the android.settings.DREAM_SETTINGS intent.</p> 1457 1458<h3 id="3_8_12_location">3.8.12. Location</h3> 1459 1460 1461<p>When a device has a hardware sensor (e.g. GPS) that is capable of providing the 1462location coordinates, location modes MUST be displayed in the Location menu 1463within Settings [<a href="http://developer.android.com/reference/android/provider/Settings.Secure.html#LOCATION_MODE">Resources, 37</a>].</p> 1464 1465<h3 id="3_8_13_unicode_and_font">3.8.13. Unicode and Font</h3> 1466 1467 1468<p>Android includes support for color emoji characters. When Android device 1469implementations include an IME, devices SHOULD provide an input method to the 1470user for the Emoji characters defined in Unicode 6.1 [<a href="http://www.unicode.org/versions/Unicode6.1.0/">Resources, 38</a>]. All devices MUST be capable of rendering these emoji characters in color glyph.</p> 1471 1472<p>Android includes support for Roboto 2 font with different 1473weights—sans-serif-thin, sans-serif-light, sans-serif-medium, sans-serif-black, 1474sans-serif-condensed, sans-serif-condensed-light—which MUST all be included for 1475the languages available on the device and full Unicode 7.0 coverage of Latin, 1476Greek, and Cyrillic, including the Latin Extended A, B, C, and D ranges, and 1477all glyphs in the currency symbols block of Unicode 7.0.</p> 1478 1479<h2 id="3_9_device_administration">3.9. Device Administration</h2> 1480 1481 1482<p>Android includes features that allow security-aware applications to perform 1483device administration functions at the system level, such as enforcing password 1484policies or performing remote wipe, through the Android Device Administration 1485API [<a href="http://developer.android.com/guide/topics/admin/device-admin.html">Resources, 39</a>]. 1486Device implementations MUST provide an implementation of the DevicePolicyManager class 1487[<a href="http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html">Resources, 40</a>]. 1488Device implementations that include support for PIN (numeric) or PASSWORD 1489(alphanumeric) based lock screens MUST support the full range of device 1490administration policies defined in the Android SDK documentation 1491[<a href="http://developer.android.com/guide/topics/admin/device-admin.html">Resources, 39</a>] 1492and report the platform feature android.software.device_admin.</p> 1493 1494<p>Device implementations MAY have a preinstalled application performing device 1495administration functions but this application MUST NOT be set out-of-the box as 1496the default Device Owner app [<a href="http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html#isDeviceOwnerApp(java.lang.String)">Resources, 41</a>].</p> 1497 1498<h2 id="3_10_accessibility">3.10. Accessibility</h2> 1499 1500 1501<p>Android provides an accessibility layer that helps users with disabilities to 1502navigate their devices more easily. In addition, Android provides platform APIs 1503that enable accessibility service implementations to receive callbacks for user 1504and system events and generate alternate feedback mechanisms, such as 1505text-to-speech, haptic feedback, and trackball/d-pad navigation [<a href="http://developer.android.com/reference/android/accessibilityservice/AccessibilityService.html">Resources, 42</a>].</p> 1506 1507<p>Device implementations include the following requirements:</p> 1508 1509<ul> 1510<li>Android Automotive implementations SHOULD provide an implementation of the 1511Android accessibility framework consistent with the default Android 1512implementation.</li> 1513<li>Device implementations (Android Automotive excluded) MUST provide an 1514implementation of the Android accessibility framework consistent with the 1515default Android implementation.</li> 1516<li>Device implementations (Android Automotive excluded) MUST support 1517third-party accessibility service implementations through the 1518android.accessibilityservice APIs 1519[<a href="http://developer.android.com/reference/android/view/accessibility/package-summary.html">Resources, 43</a>]</li> 1520<li>Device implementations (Android Automotive excluded) MUST generate 1521AccessibilityEvents and deliver these events to all registered 1522AccessibilityService implementations in a manner consistent with the default 1523Android implementation</li> 1524<li> Device implementations (Android Automotive and Android Watch devices with 1525no audio output excluded), MUST provide a user-accessible mechanism to enable 1526and disable accessibility services, and MUST display this interface in response 1527to the android.provider.Settings.ACTION_ACCESSIBILITY_SETTINGS intent.</li> 1528</ul> 1529 1530<p>Additionally, device implementations SHOULD provide an implementation of an 1531accessibility service on the device, and SHOULD provide a mechanism for users 1532to enable the accessibility service during device setup. An open source 1533implementation of an accessibility service is available from the Eyes Free 1534project [<a href="http://code.google.com/p/eyes-free/">Resources, 44</a>].</p> 1535 1536<h2 id="3_11_text-to-speech">3.11. Text-to-Speech</h2> 1537 1538 1539<p>Android includes APIs that allow applications to make use of text-to-speech 1540(TTS) services and allows service providers to provide implementations of TTS 1541services [<a href="http://developer.android.com/reference/android/speech/tts/package-summary.html">Resources, 45</a>]. Device implementations reporting the feature android.hardware.audio.output 1542MUST meet these requirements related to the Android TTS framework. </p> 1543 1544<p>Android Automotive implementations:</p> 1545<ul> 1546<li>MUST support the Android TTS framework APIs.</li> 1547<li>MAY support installation of third-party TTS engines. If supported, partners 1548MUST provide a user-accessible interface that allows the user to select a TTS 1549engine for use at system level.</li> 1550</ul> 1551 1552<p>All other device implementations:</p> 1553 1554<ul> 1555 <li> MUST support the Android TTS framework APIs and SHOULD include a TTS engine 1556supporting the languages available on the device. Note that the upstream 1557Android open source software includes a full-featured TTS engine 1558implementation. 1559 <li> MUST support installation of third-party TTS engines 1560 <li> MUST provide a user-accessible interface that allows users to select a TTS 1561engine for use at the system level 1562</ul> 1563 1564<h2 id="3_12_tv_input_framework">3.12. TV Input Framework</h2> 1565 1566 1567<p>The Android Television Input Framework (TIF) simplifies the delivery of live 1568content to Android Television devices. TIF provides a standard API to create 1569input modules that control Android Television devices. Android Television 1570device implementations MUST support Television Input Framework [<a href="http://source.android.com/devices/tv/index.html">Resources, 46</a>].</p> 1571 1572<p>Device implementations that support TIF MUST declare the platform feature 1573android.software.live_tv.</p> 1574 1575<h1 id="4_application_packaging_compatibility">4. Application Packaging Compatibility</h1> 1576 1577 1578<p>Device implementations MUST install and run Android “.apk” files as generated 1579by the “aapt” tool included in the official Android SDK [<a href="http://developer.android.com/tools/help/index.html">Resources, 47</a>].</p> 1580 1581<p>Devices implementations MUST NOT extend either the .apk [<a href="http://developer.android.com/guide/components/fundamentals.html">Resources, 48</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/+/lollipop-release/docs/">Resources, 20</a>], or RenderScript bytecode formats in such a way that would prevent those 1582files from installing and running correctly on other compatible devices.</p> 1583 1584<h1 id="5_multimedia_compatibility">5. Multimedia Compatibility</h1> 1585 1586 1587<h2 id="5_1_media_codecs">5.1. Media Codecs</h2> 1588 1589 1590<p>Device implementations MUST support the core media formats specified in the 1591Android SDK documentation [<a href="http://developer.android.com/guide/appendix/media-formats.html">Resources, 50</a>] except where explicitly permitted in this document. Specifically, device 1592implementations MUST support the media formats, encoders, decoders, file types, 1593and container formats defined in the tables below and reported via MediaCodecList 1594[<a href="http://developer.android.com/reference/android/media/MediaCodecList.html">Resources,112</a>]. 1595Device implementations MUST also be able to decode all profiles reported in its CamcorderProfile 1596[<a href="http://developer.android.com/reference/android/media/CamcorderProfile.html">Resources, 1597113</a>]. 1598 1599All of these codecs are 1600provided as software implementations in the preferred Android implementation 1601from the Android Open Source Project.</p> 1602 1603<p>Please note that neither Google nor the Open Handset Alliance make any 1604representation that these codecs are free from third-party patents. Those 1605intending to use this source code in hardware or software products are advised 1606that implementations of this code, including in open source software or 1607shareware, may require patent licenses from the relevant patent holders.</p> 1608 1609<h3 id="5_1_1_audio_codecs">5.1.1. Audio Codecs</h3> 1610 1611<table> 1612 <tr> 1613 <th>Format/Codec</th> 1614 <th>Encoder</th> 1615 <th>Decoder</th> 1616 <th>Details</th> 1617 <th>Supported File Types/Container Formats</th> 1618 </tr> 1619 <tr> 1620 <td>MPEG-4 AAC Profile</p> 1621 1622<p>(AAC LC)</td> 1623 <td>REQUIRED<sup>1</sup></td> 1624 <td>REQUIRED</td> 1625 <td>Support for mono/stereo/5.0/5.1<sup>2</sup> content with standard sampling rates from 8 to 162648 kHz.</td> 1627 <td> 1628 <ul> 1629 <li class="table_list">3GPP (.3gp)</li> 1630 <li class="table_list">MPEG-4 (.mp4, .m4a)</li> 1631 <li class="table_list">ADTS raw AAC (.aac, decode in Android 3.1+, encode in Android 4.0+, ADIF not 1632supported)</li> 1633 <li class="table_list">MPEG-TS (.ts, not seekable, Android 3.0+)</li></ul></td> 1634 </tr> 1635 <tr> 1636 <td>MPEG-4 HE AAC Profile (AAC+)</td> 1637 <td>REQUIRED<sup>1</sup><br>(Android 4.1+)</td> 1638 <td>REQUIRED</td> 1639 <td>Support for mono/stereo/5.0/5.1<sup>2</sup> content with standard sampling rates from 16 1640to 48 kHz.</td> 1641 <td></td> 1642 </tr> 1643 <tr> 1644 <td>MPEG-4 HE AACv2</p> 1645 1646<p>Profile (enhanced AAC+)</td> 1647 <td> </td> 1648 <td>REQUIRED</td> 1649 <td>Support for mono/stereo/5.0/5.1<sup>2</sup> content with standard sampling rates from 16 1650to 48 kHz.</td> 1651 <td></td> 1652 </tr> 1653 <tr> 1654 <td>AAC ELD (enhanced low delay AAC)</td> 1655 <td>REQUIRED<sup>1</sup> </p> 1656 1657<p>(Android 4.1+)</td> 1658 <td>REQUIRED</p> 1659 1660<p>(Android 4.1+)</td> 1661 <td>Support for mono/stereo content with standard sampling rates from 16 to 48 kHz.</td> 1662 <td></td> 1663 </tr> 1664 <tr> 1665 <td>AMR-NB</td> 1666 <td>REQUIRED<sup>3</sup></td> 1667 <td>REQUIRED<sup>3</sup></td> 1668 <td>4.75 to 12.2 kbps sampled @ 8kHz</td> 1669 <td>3GPP (.3gp)</td> 1670 </tr> 1671 <tr> 1672 <td>AMR-WB</td> 1673 <td>REQUIRED<sup>3</sup></td> 1674 <td>REQUIRED<sup>3</sup></td> 1675 <td>9 rates from 6.60 kbit/s to 23.85 kbit/s sampled @ 16kHz</td> 1676 <td></td> 1677 </tr> 1678 <tr> 1679 <td>FLAC</td> 1680 <td></td> 1681 <td>REQUIRED <br>(Android 3.1+)</td> 1682 <td>Mono/Stereo (no multichannel). Sample rates up to 48 kHz (but up to 44.1 kHz is 1683recommended on devices with 44.1 kHz output, as the 48 to 44.1 kHz downsampler 1684does not include a low-pass filter). 16-bit recommended; no dither applied for 168524-bit.</td> 1686 <td>FLAC (.flac) only</td> 1687 </tr> 1688 <tr> 1689 <td>MP3</td> 1690 <td></td> 1691 <td>REQUIRED</td> 1692 <td>Mono/Stereo 8-320Kbps constant (CBR) or variable bitrate (VBR)</td> 1693 <td>MP3 (.mp3)</td> 1694 </tr> 1695 <tr> 1696 <td>MIDI</td> 1697 <td></td> 1698 <td>REQUIRED</td> 1699 <td>MIDI Type 0 and 1. DLS Version 1 and 2. XMF and Mobile XMF. Support for 1700ringtone formats RTTTL/RTX, OTA, and iMelody</td> 1701 <td><ul> 1702 <li class="table_list">Type 0 and 1 (.mid, .xmf, .mxmf)</li> 1703 <li class="table_list">RTTTL/RTX (.rtttl, .rtx)</li> 1704 <li class="table_list">OTA (.ota)</li> 1705 <li class="table_list">iMelody (.imy)</li></ul></td> 1706 </tr> 1707 <tr> 1708 <td>Vorbis</td> 1709 <td></td> 1710 <td>REQUIRED</td> 1711 <td></td> 1712 <td><ul> 1713 <li class="table_list">Ogg (.ogg)</li> 1714 <li class="table_list">Matroska (.mkv, Android 4.0+)</li></ul></td> 1715 </tr> 1716 <tr> 1717 <td>PCM/WAVE</td> 1718 <td>REQUIRED<sup>4</sup><br> (Android 4.1+)</td> 1719 <td>REQUIRED</td> 1720 <td>16-bit linear PCM (rates up to limit of hardware). Devices MUST support 1721sampling rates for raw PCM recording at 8000, 11025, 16000, and 44100 Hz 1722frequencies.</td> 1723 <td>WAVE (.wav)</td> 1724 </tr> 1725 <tr> 1726 <td>Opus</td> 1727 <td></td> 1728 <td>REQUIRED<br> (Android 5.0+)</td> 1729 <td></td> 1730 <td>Matroska (.mkv)</td> 1731 </tr> 1732</table> 1733 1734 1735<p class="table_footnote"> 1 Required for device implementations that define android.hardware.microphone 1736but optional for Android Watch device implementations.</p> 1737 1738<p class="table_footnote">2 Only downmix of 5.0/5.1 content is required; recording or rendering more than 17392 channels is optional.</p> 1740 1741<p class="table_footnote">3 Required for Android Handheld device implementations. </p> 1742 1743<p class="table_footnote">4 Required for device implementations that define android.hardware.microphone, 1744including Android Watch device implementations.</p> 1745 1746<h3 id="5_1_2_image_codecs">5.1.2. Image Codecs</h3> 1747 1748<table> 1749 <tr> 1750 <th>Format/Codec</th> 1751 <th>Encoder</th> 1752 <th>Decoder</th> 1753 <th>Details</th> 1754 <th>Supported File Types/Container Formats</th> 1755 </tr> 1756 <tr> 1757 <td>JPEG</td> 1758 <td>REQUIRED</td> 1759 <td>REQUIRED</td> 1760 <td>Base+progressive</td> 1761 <td>JPEG (.jpg)</td> 1762 </tr> 1763 <tr> 1764 <td>GIF</td> 1765 <td></td> 1766 <td>REQUIRED</td> 1767 <td></td> 1768 <td>GIF (.gif)</td> 1769 </tr> 1770 <tr> 1771 <td>PNG</td> 1772 <td>REQUIRED</td> 1773 <td>REQUIRED</td> 1774 <td></td> 1775 <td>PNG (.png)</td> 1776 </tr> 1777 <tr> 1778 <td>BMP</td> 1779 <td></td> 1780 <td>REQUIRED</td> 1781 <td></td> 1782 <td>BMP (.bmp)</td> 1783 </tr> 1784 <tr> 1785 <td>WebP</td> 1786 <td>REQUIRED</td> 1787 <td>REQUIRED</td> 1788 <td></td> 1789 <td>WebP (.webp)</td> 1790 </tr> 1791</table> 1792 1793 1794<h3 id="5_1_3_video_codecs">5.1.3. Video Codecs</h3> 1795 1796<p>Video codecs are optional for Android Watch device implementations.</p> 1797 1798<table> 1799 <tr> 1800 <th>Format/Codec</th> 1801 <th>Encoder</th> 1802 <th>Decoder</th> 1803 <th>Details</th> 1804 <th>Supported File Types/<br>Container Formats</th> 1805 </tr> 1806 <tr> 1807 <td>H.263</td> 1808 <td>REQUIRED<sup>1</sup></td> 1809 <td>REQUIRED<sup>2</sup></td> 1810 <td></td> 1811 <td><ul> 1812 <li class="table_list">3GPP (.3gp)</li> 1813 <li class="table_list">MPEG-4 (.mp4)</li></ul></td> 1814 </tr> 1815 <tr> 1816 <td>H.264 AVC</td> 1817 <td>REQUIRED<sup>2</sup></td> 1818 <td>REQUIRED<sup>2</sup></td> 1819 <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> 1820 <td><ul> 1821 <li class="table_list">3GPP (.3gp)</li> 1822 <li class="table_list">MPEG-4 (.mp4)</li> 1823 <li class="table_list">MPEG-TS (.ts, AAC audio only, not seekable, Android 3.0+)</li></ul></td> 1824 </tr> 1825 <tr> 1826 <td>H.265 HEVC</td> 1827 <td></td> 1828 <td>REQUIRED<sup>5</sup></td> 1829 <td>See <a href="#5_3_video_decoding">section 5.3</a> for details</td> 1830 <td>MPEG-4 (.mp4)</td> 1831 </tr> 1832 <tr> 1833 <td>MPEG-4 SP</td> 1834 <td></td> 1835 <td>REQUIRED<sup>2</sup></td> 1836 <td></td> 1837 <td>3GPP (.3gp)</td> 1838 </tr> 1839 <tr> 1840 <td>VP8<sup>3</sup></td> 1841 <td>REQUIRED<sup>2</sup></p> 1842 1843<p>(Android 4.3+)</td> 1844 <td>REQUIRED<sup>2</sup></p> 1845 1846<p>(Android 2.3.3+)</td> 1847 <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> 1848 <td><ul> 1849 <li class="table_list">WebM (.webm) [<a href="http://www.webmproject.org/">Resources, 110</a></li> 1850 <li class="table_list">Matroska (.mkv, Android 4.0+)<sup>4</sup></li></ul></td> 1851 </tr> 1852 <tr> 1853 <td>VP9</td> 1854 <td></td> 1855 <td>REQUIRED<sup>2</sup><br> (Android 4.4+)</td> 1856 <td>See <a href="#5_3_video_decoding">section 5.3</a> for details</td> 1857 <td><ul> 1858 <li class="table_list">WebM (.webm) [<a href="http://www.webmproject.org/">Resources, 110</a>]</li> 1859 <li class="table_list">Matroska (.mkv, Android 4.0+)<sup>4</sup></li></ul></td> 1860 </tr> 1861</table> 1862 1863 1864<p class="table_footnote">1 Required for device implementations that include camera hardware and define 1865android.hardware.camera or android.hardware.camera.front.</p> 1866 1867<p class="table_footnote">2 Required for device implementations except Android Watch devices. </p> 1868 1869<p class="table_footnote">3 For acceptable quality of web video streaming and video-conference services, 1870device implementations SHOULD use a hardware VP8 codec that meets the 1871requirements in [<a href="http://www.webmproject.org/hardware/rtc-coding-requirements/">Resources, 51</a>].</p> 1872 1873<p class="table_footnote">4 Device implementations SHOULD support writing Matroska WebM files.</p> 1874 1875<p class="table_footnote">5 Strongly recommended for Android Automotive, optional for Android Watch, and required for all other device types.</p> 1876 1877<h2 id="5_2_video_encoding">5.2. Video Encoding</h2> 1878 1879<div class="note"> 1880<p>Video codecs are optional for Android Watch device implementations.</p> 1881</div> 1882 1883 1884<p>Android device implementations with H.264 codec support, MUST support Baseline 1885Profile Level 3 and the following SD (Standard Definition) video encoding 1886profiles and SHOULD support Main Profile Level 4 and the following HD (High 1887Definition) video encoding profiles. Android Television devices are STRONGLY 1888RECOMMENDED to encode HD 1080p video at 30 fps.</p> 1889<table> 1890 <tr> 1891 <th></th> 1892 <th>SD (Low quality)</th> 1893 <th>SD (High quality)</th> 1894 <th>HD 720p1</th> 1895 <th>HD 1080p1</th> 1896 </tr> 1897 <tr> 1898 <th>Video resolution</th> 1899 <td>320 x 240 px</td> 1900 <td>720 x 480 px</td> 1901 <td>1280 x 720 px</td> 1902 <td>1920 x 1080 px</td> 1903 </tr> 1904 <tr> 1905 <th>Video frame rate</th> 1906 <td>20 fps</td> 1907 <td>30 fps</td> 1908 <td>30 fps</td> 1909 <td>30 fps</td> 1910 </tr> 1911 <tr> 1912 <th>Video bitrate</th> 1913 <td>384 Kbps</td> 1914 <td>2 Mbps</td> 1915 <td>4 Mbps</td> 1916 <td>10 Mbps</td> 1917 </tr> 1918</table> 1919 1920 1921<p class="table_footnote">1 When supported by hardware, but STRONGLY RECOMMENDED for Android Television 1922devices.</p> 1923 1924<p>Android device implementations with VP8 codec support MUST support the SD video 1925encoding profiles and SHOULD support the following HD (High Definition) video 1926encoding profiles.</p> 1927<table> 1928 <tr> 1929 <th></th> 1930 <th>SD (Low quality)</th> 1931 <th>SD (High quality)</th> 1932 <th>HD 720p1</th> 1933 <th>HD 1080p1</th> 1934 </tr> 1935 <tr> 1936 <th>Video resolution</th> 1937 <td>320 x 180 px</td> 1938 <td>640 x 360 px</td> 1939 <td>1280 x 720 px</td> 1940 <td>1920 x 1080 px</td> 1941 </tr> 1942 <tr> 1943 <th>Video frame rate</th> 1944 <td>30 fps</td> 1945 <td>30 fps</td> 1946 <td>30 fps</td> 1947 <td>30 fps</td> 1948 </tr> 1949 <tr> 1950 <th>Video bitrate</th> 1951 <td>800 Kbps </td> 1952 <td>2 Mbps</td> 1953 <td>4 Mbps</td> 1954 <td>10 Mbps</td> 1955 </tr> 1956</table> 1957 1958<p class="table_footnote">1 When supported by hardware.</p> 1959 1960<h2 id="5_3_video_decoding">5.3. Video Decoding</h2> 1961 1962<div class="note"> 1963<p>Video codecs are optional for Android Watch device implementations.</p> 1964</div> 1965 1966 1967<p>Device implementations MUST support dynamic video resolution switching within 1968the same stream for all VP8, VP9, H.264, and H.265 codecs exposed to developers 1969through the standard Android APIs.</p> 1970 1971<p>Android device implementations with H.264 decoders, MUST support Baseline 1972Profile Level 3 and the following SD video decoding profiles and SHOULD support 1973the HD decoding profiles. Android Television devices MUST support High Profile 1974Level 4.2 and the HD 1080p decoding profile.</p> 1975<table> 1976 <tr> 1977 <th></th> 1978 <th>SD (Low quality)</th> 1979 <th>SD (High quality)</th> 1980 <th>HD 720p1</th> 1981 <th>HD 1080p1</th> 1982 </tr> 1983 <tr> 1984 <th>Video resolution</th> 1985 <td>320 x 240 px</td> 1986 <td>720 x 480 px</td> 1987 <td>1280 x 720 px</td> 1988 <td>1920 x 1080 px</td> 1989 </tr> 1990 <tr> 1991 <th>Video frame rate</th> 1992 <td>30 fps</td> 1993 <td>30 fps</td> 1994 <td>30 fps / 60 fps2</td> 1995 <td>30 fps / 60 fps2</td> 1996 </tr> 1997 <tr> 1998 <th>Video bitrate</th> 1999 <td>800 Kbps </td> 2000 <td>2 Mbps</td> 2001 <td>8 Mbps</td> 2002 <td>20 Mbps</td> 2003 </tr> 2004</table> 2005 2006 2007<p class="table_footnote">1 Required for Android Television device implementations, but for other device 2008types only when supported by hardware.</p> 2009 2010<p class="table_footnote">2 Required for Android Television device implementations.</p> 2011 2012<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 2013decoding profiles. Android Television devices MUST support the HD 1080p 2014decoding profile. </p> 2015<table> 2016 <tr> 2017 <th></th> 2018 <th>SD (Low quality)</th> 2019 <th>SD (High quality)</th> 2020 <th>HD 720p1</th> 2021 <th>HD 1080p1</th> 2022 </tr> 2023 <tr> 2024 <th>Video resolution</th> 2025 <td>320 x 180 px</td> 2026 <td>640 x 360 px</td> 2027 <td>1280 x 720 px</td> 2028 <td>1920 x 1080 px</td> 2029 </tr> 2030 <tr> 2031 <th>Video frame rate</th> 2032 <td>30 fps</td> 2033 <td>30 fps</td> 2034 <td>30 fps / 60 fps2</td> 2035 <td>30 / 60 fps2</td> 2036 </tr> 2037 <tr> 2038 <th>Video bitrate</th> 2039 <td>800 Kbps </td> 2040 <td>2 Mbps</td> 2041 <td>8 Mbps</td> 2042 <td>20 Mbps</td> 2043 </tr> 2044</table> 2045 2046 2047<p class="table_footnote">1 Required for Android Television device implementations, but for other type of 2048devices only when supported by hardware.</p> 2049 2050<p class="table_footnote">2 Required for Android Television device implementations.</p> 2051 2052<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 2053HD decoding profiles. Android Television devices are STRONGLY RECOMMENDED to 2054support the HD 1080p decoding profile and SHOULD support the UHD decoding 2055profile. When the UHD video decoding profile is supported, it MUST support 8 2056bit color depth.</p> 2057<table> 2058 <tr> 2059 <th></th> 2060 <th>SD (Low quality)</th> 2061 <th>SD (High quality)</th> 2062 <th>HD 720p 1</th> 2063 <th>HD 1080p 2</th> 2064 <th>UHD 2</th> 2065 </tr> 2066 <tr> 2067 <th>Video resolution</th> 2068 <td>320 x 180 px</td> 2069 <td>640 x 360 px</td> 2070 <td>1280 x 720 px</td> 2071 <td>1920 x 1080 px</td> 2072 <td>3840 x 2160 px</td> 2073 </tr> 2074 <tr> 2075 <th>Video frame rate</th> 2076 <td>30 fps</td> 2077 <td>30 fps</td> 2078 <td>30 fps</td> 2079 <td>30 fps</td> 2080 <td>30 fps</td> 2081 </tr> 2082 <tr> 2083 <th>Video bitrate</th> 2084 <td>600 Kbps </td> 2085 <td>1.6 Mbps</td> 2086 <td>4 Mbps</td> 2087 <td>10 Mbps</td> 2088 <td>20 Mbps</td> 2089 </tr> 2090</table> 2091 2092 2093<p class="table_footnote">1 Required for Android Television device implementations, but for other type of 2094devices only when supported by hardware.</p> 2095 2096<p class="table_footnote">2 STRONGLY RECOMMENDED for Android Television device implementations when 2097supported by hardware.</p> 2098 2099<p>Android device implementations, when supporting H.265 codec as described in <a href="#5_1_3_video_codecs">section 5.1.3</a>, MUST support the Main Profile Level 3 Main tier and the following SD video 2100decoding profiles and SHOULD support the HD decoding profiles. Android 2101Television devices MUST support the Main Profile Level 4.1 Main tier and the HD 21021080p decoding profile and SHOULD support Main10 Level 5 Main Tier profile and 2103the UHD decoding profile.</p> 2104<table> 2105 <tr> 2106 <th></th> 2107 <th>SD (Low quality)</th> 2108 <th>SD (High quality)</th> 2109 <th>HD 720p </strong>1 </td> 2110 <th>HD 1080p </strong>1 </td> 2111 <th>UHD </strong>2</td> 2112 </tr> 2113 <tr> 2114 <th>Video resolution</th> 2115 <td>352 x 288 px</td> 2116 <td>640 x 360 px</td> 2117 <td>1280 x 720 px</td> 2118 <td>1920 x 1080 px</td> 2119 <td>3840 x 2160 px</td> 2120 </tr> 2121 <tr> 2122 <th>Video frame rate</th> 2123 <td>30 fps</td> 2124 <td>30 fps</td> 2125 <td>30 fps</td> 2126 <td>30 fps</td> 2127 <td>30 fps</td> 2128 </tr> 2129 <tr> 2130 <th>Video bitrate</th> 2131 <td>600 Kbps </td> 2132 <td>1.6 Mbps</td> 2133 <td>4 Mbps</td> 2134 <td>10 Mbps</td> 2135 <td>20 Mbps</td> 2136 </tr> 2137</table> 2138 2139 2140<p class="table_footnote">1 Required for Android Television device implementation, but for other type of 2141devices only when supported by hardware.</p> 2142 2143<p class="table_footnote">2 Required for Android Television device implementations when supported by 2144hardware.</p> 2145 2146<h2 id="5_4_audio_recording">5.4. Audio Recording</h2> 2147 2148 2149<p>While some of the requirements outlined in this section are stated as SHOULD 2150since Android 4.3, the Compatibility Definition for a future version is planned 2151to change these to MUST. Existing and new Android devices are <strong>very strongly encouraged</strong> to meet these requirements, or they will not be able to attain Android 2152compatibility when upgraded to the future version.</p> 2153 2154<h3 id="5_4_1_raw_audio_capture">5.4.1. Raw Audio Capture</h3> 2155 2156 2157<p>Device implementations that declare android.hardware.microphone MUST allow 2158capture of raw audio content with the following characteristics:</p> 2159 2160<ul> 2161 <li><strong>Format</strong>: Linear PCM, 16-bit 2162 <li><strong>Sampling rates</strong>: 8000, 11025, 16000, 44100 2163 <li><strong>Channels</strong>: Mono 2164</ul> 2165 2166<p>Device implementations that declare android.hardware.microphone SHOULD allow 2167capture of raw audio content with the following characteristics:</p> 2168 2169<ul> 2170 <li><strong>Format</strong>: Linear PCM, 16-bit 2171 <li><strong>Sampling rates</strong>: 22050, 48000 2172 <li><strong>Channels</strong>: Stereo 2173</ul> 2174 2175<h3 id="5_4_2_capture_for_voice_recognition">5.4.2. Capture for Voice Recognition</h3> 2176 2177 2178<p>In addition to the above recording specifications, when an application has 2179started recording an audio stream using the 2180android.media.MediaRecorder.AudioSource.VOICE_RECOGNITION audio source:</p> 2181 2182<ul> 2183 <li>The device SHOULD exhibit approximately flat amplitude versus frequency 2184characteristics: specifically, ±3 dB, from 100 Hz to 4000 Hz. 2185 <li>Audio input sensitivity SHOULD be set such that a 90 dB sound power level (SPL) 2186source at 1000 Hz yields RMS of 2500 for 16-bit samples. 2187 <li>PCM amplitude levels SHOULD linearly track input SPL changes over at least a 30 2188dB range from -18 dB to +12 dB re 90 dB SPL at the microphone. 2189 <li>Total harmonic distortion SHOULD be less than 1% for 1Khz at 90 dB SPL input 2190level at the microphone. 2191 <li>Noise reduction processing, if present, MUST be disabled. 2192 <li>Automatic gain control, if present, MUST be disabled 2193</ul> 2194 2195<p>If the platform supports noise suppression technologies tuned for speech 2196recognition, the effect MUST be controllable from the 2197android.media.audiofx.NoiseSuppressor API. Moreover, the UUID field for the 2198noise suppressor’s effect descriptor MUST uniquely identify each implementation 2199of the noise suppression technology.</p> 2200 2201<h3 id="5_4_3_capture_for_rerouting_of_playback">5.4.3. Capture for Rerouting of Playback</h3> 2202 2203 2204<p>The android.media.MediaRecorder.AudioSource class includes the REMOTE_SUBMIX 2205audio source. Devices that declare android.hardware.audio.output MUST properly 2206implement the REMOTE_SUBMIX audio source so that when an application uses the 2207android.media.AudioRecord API to record from this audio source, it can capture 2208a mix of all audio streams except for the following:</p> 2209 2210<ul> 2211 <li>STREAM_RING 2212 <li>STREAM_ALARM 2213 <li>STREAM_NOTIFICATION 2214</ul> 2215 2216<h2 id="5_5_audio_playback">5.5. Audio Playback</h2> 2217 2218 2219<p>Device implementations that declare android.hardware.audio.output MUST conform 2220to the requirements in this section.</p> 2221 2222<h3 id="5_5_1_raw_audio_playback">5.5.1. Raw Audio Playback</h3> 2223 2224 2225<p>The device MUST allow playback of raw audio content with the following 2226characteristics:</p> 2227 2228<ul> 2229 <li><strong>Format</strong>: Linear PCM, 16-bit</li> 2230 <li><strong>Sampling rates</strong>: 8000, 11025, 16000, 22050, 32000, 44100</li> 2231 <li><strong>Channels</strong>: Mono, Stereo</li> 2232</ul> 2233 2234<p>The device SHOULD allow playback of raw audio content with the following 2235characteristics:</p> 2236 2237<ul> 2238 <li><strong>Sampling rates</strong>: 24000, 48000</li> 2239</ul> 2240 2241<h3 id="5_5_2_audio_effects">5.5.2. Audio Effects</h3> 2242 2243 2244<p>Android provides an API for audio effects for device implementations [<a href="http://developer.android.com/reference/android/media/audiofx/AudioEffect.html">Resources, 52</a>]. Device implementations that declare the feature 2245android.hardware.audio.output:</p> 2246 2247<ul> 2248 <li>MUST support the EFFECT_TYPE_EQUALIZER and EFFECT_TYPE_LOUDNESS_ENHANCER 2249implementations controllable through the AudioEffect subclasses Equalizer, 2250LoudnessEnhancer.</li> 2251 <li>MUST support the visualizer API implementation, controllable through the 2252Visualizer class.</li> 2253 <li>SHOULD support the EFFECT_TYPE_BASS_BOOST, EFFECT_TYPE_ENV_REVERB, 2254EFFECT_TYPE_PRESET_REVERB, and EFFECT_TYPE_VIRTUALIZER implementations 2255controllable through the AudioEffect sub-classes BassBoost, 2256EnvironmentalReverb, PresetReverb, and Virtualizer.</li> 2257</ul> 2258 2259<h3 id="5_5_3_audio_output_volume">5.5.3. Audio Output Volume</h3> 2260 2261 2262<p>Android Television device implementations MUST include support for system 2263Master Volume and digital audio output volume attenuation on supported outputs, 2264except for compressed audio passthrough output (where no audio decoding is done 2265on the device).</p> 2266 2267<h2 id="5_6_audio_latency">5.6. Audio Latency</h2> 2268 2269 2270<p>Audio latency is the time delay as an audio signal passes through a system. 2271Many classes of applications rely on short latencies, to achieve real-time 2272sound effects.</p> 2273 2274<p>For the purposes of this section, use the following definitions:</p> 2275 2276<ul> 2277 <li><strong>output latency</strong>. The interval between when an application writes a frame of PCM-coded data and 2278when the corresponding sound can be heard by an external listener or observed 2279by a transducer.</li> 2280 <li><strong>cold output latency</strong>. The output latency for the first frame, when the audio output system has been 2281idle and powered down prior to the request.</li> 2282 <li><strong>continuous output latency</strong>. The output latency for subsequent frames, after the device is playing audio.</li> 2283 <li><strong>input latency</strong>. The interval between when an external sound is presented to the device and 2284when an application reads the corresponding frame of PCM-coded data.</li> 2285 <li><strong>cold input latency</strong>. The sum of lost input time and the input latency for the first frame, when the 2286audio input system has been idle and powered down prior to the request.</li> 2287 <li><strong>continuous input latency</strong>. The input latency for subsequent frames, while the device is capturing audio.</li> 2288 <li><strong>cold output jitter</strong>. The variance among separate measurements of cold output latency values.</li> 2289 <li><strong>cold input jitter</strong>. The variance among separate measurements of cold input latency values.</li> 2290 <li><strong>continuous round-trip latency</strong>. The sum of continuous input latency plus continuous output latency plus 5 2291milliseconds.</li> 2292 <li><strong>OpenSL ES PCM buffer queue API</strong>. The set of PCM-related OpenSL ES APIs within Android NDK; see 2293NDK_root/docs/opensles/index.html.</li> 2294</ul> 2295 2296<p>Device implementations that declare android.hardware.audio.output SHOULD meet 2297or exceed these audio output requirements:</p> 2298 2299<ul> 2300 <li>cold output latency of 100 milliseconds or less</li> 2301 <li>continuous output latency of 45 milliseconds or less</li> 2302 <li>minimize the cold output jitter</li> 2303</ul> 2304 2305<p>If a device implementation meets the requirements of this section after any 2306initial calibration when using the OpenSL ES PCM buffer queue API, for 2307continuous output latency and cold output latency over at least one supported 2308audio output device, it MAY report support for low-latency audio, by reporting 2309the feature android.hardware.audio.low_latency via the 2310android.content.pm.PackageManager class [<a href="http://developer.android.com/reference/android/content/pm/PackageManager.html">Resources, 53</a>]. Conversely, if the device implementation does not meet these requirements it 2311MUST NOT report support for low-latency audio.</p> 2312 2313<p>Device implementations that include android.hardware.microphone SHOULD meet 2314these input audio requirements:</p> 2315 2316<ul> 2317 <li>cold input latency of 100 milliseconds or less</li> 2318 <li>continuous input latency of 30 milliseconds or less</li> 2319 <li>continuous round-trip latency of 50 milliseconds or less</li> 2320 <li>minimize the cold input jitter</li> 2321</ul> 2322 2323<h2 id="5_7_network_protocols">5.7. Network Protocols</h2> 2324 2325 2326<p>Devices MUST support the media network protocols for audio and video playback 2327as specified in the Android SDK documentation [<a href="http://developer.android.com/guide/appendix/media-formats.html">Resources, 50</a>]. Specifically, devices MUST support the following media network protocols:</p> 2328 2329<ul> 2330 <li>RTSP (RTP, SDP)</li> 2331 <li>HTTP(S) progressive streaming</li> 2332 <li>HTTP(S) Live Streaming draft protocol, Version 3 [<a href="http://tools.ietf.org/html/draft-pantos-http-live-streaming-03">Resources, 54</a>]</li> 2333</ul> 2334 2335<h2 id="5_8_secure_media">5.8. Secure Media</h2> 2336 2337 2338<p>Device implementations that support secure video output and are capable of 2339supporting secure surfaces MUST declare support for Display.FLAG_SECURE. Device 2340implementations that declare support for Display.FLAG_SECURE, if they support a 2341wireless display protocol, MUST secure the link with a cryptographically strong 2342mechanism such as HDCP 2.x or higher for Miracast wireless displays. Similarly 2343if they support a wired external display, the device implementations MUST 2344support HDCP 1.2 or higher. Android Television device implementations MUST 2345support HDCP 2.2 for devices supporting 4K resolution and HDCP 1.4 or above for 2346lower resolutions. The upstream Android open source implementation includes 2347support for wireless (Miracast) and wired (HDMI) displays that satisfies this 2348requirement.</p> 2349 2350<h1 id="6_developer_tools_and_options_compatibility">6. Developer Tools and Options Compatibility</h1> 2351 2352 2353<h2 id="6_1_developer_tools">6.1. Developer Tools</h2> 2354 2355 2356<p>Device implementations MUST support the Android Developer Tools provided in the 2357Android SDK. Android compatible devices MUST be compatible with:</p> 2358 2359<ul> 2360 <li><strong>Android Debug Bridge (adb)</strong> [<a href="http://developer.android.com/tools/help/adb.html">Resources, 55</a>]</li> 2361</ul> 2362 2363<p>Device implementations MUST support all adb functions as documented in the 2364Android SDK including dumpsys [<a href="https://source.android.com/devices/input/diagnostics.html">Resources, 56</a>]. The device-side adb daemon MUST be inactive by default and there MUST be a 2365user-accessible mechanism to turn on the Android Debug Bridge. If a device 2366implementation omits USB peripheral mode, it MUST implement the Android Debug 2367Bridge via local-area network (such as Ethernet or 802.11). </p> 2368 2369<p>Android includes support for secure adb. Secure adb enables adb on known 2370authenticated hosts. Device implementations MUST support secure adb.</p> 2371 2372<ul> 2373 <li><strong>Dalvik Debug Monitor Service (ddms)</strong> [<a href="http://developer.android.com/tools/debugging/ddms.html">Resources, 57</a>]</li> 2374</ul> 2375 2376<p>Device implementations MUST support all ddms features as documented in the 2377Android SDK. As ddms uses adb, support for ddms SHOULD be inactive by default, 2378but MUST be supported whenever the user has activated the Android Debug Bridge, 2379as above.</p> 2380 2381<ul> 2382 <li><strong>Monkey</strong> [<a href="http://developer.android.com/tools/help/monkey.html">Resources, 58</a>]</li> 2383</ul> 2384 2385<p>Device implementations MUST include the Monkey framework, and make it available 2386for applications to use.</p> 2387 2388<ul> 2389 <li><strong>SysTrace</strong> [<a href="http://developer.android.com/tools/help/systrace.html">Resources, 59</a>]</li> 2390</ul> 2391 2392<p>Device implementations MUST support systrace tool as documented in the Android 2393SDK. Systrace must be inactive by default, and there MUST be a user-accessible 2394mechanism to turn on Systrace.</p> 2395 2396<p>Most Linux-based systems and Apple Macintosh systems recognize Android devices 2397using the standard Android SDK tools, without additional support; however 2398Microsoft Windows systems typically require a driver for new Android devices. 2399(For instance, new vendor IDs and sometimes new device IDs require custom USB 2400drivers for Windows systems.) If a device implementation is unrecognized by the 2401adb tool as provided in the standard Android SDK, device implementers MUST 2402provide Windows drivers allowing developers to connect to the device using the 2403adb protocol. These drivers MUST be provided for Windows XP, Windows Vista, 2404Windows 7, Windows 8, and Windows 9 in both 32-bit and 64-bit versions.</p> 2405 2406<h2 id="6_2_developer_options">6.2. Developer Options</h2> 2407 2408 2409<p>Android includes support for developers to configure application 2410development-related settings. Device implementations MUST honor the 2411android.settings.APPLICATION_DEVELOPMENT_SETTINGS intent to show application 2412development-related settings [<a href="http://developer.android.com/reference/android/provider/Settings.html#ACTION_APPLICATION_DEVELOPMENT_SETTINGS">Resources, 60</a>]. The upstream Android implementation hides the Developer Options menu by 2413default and enables users to launch Developer Options after pressing seven (7) 2414times on the <strong>Settings</strong> > <strong>About Device</strong> > <strong>Build Number</strong> menu item. Device implementations MUST provide a consistent experience for 2415Developer Options. Specifically, device implementations MUST hide Developer 2416Options by default and MUST provide a mechanism to enable Developer Options 2417that is consistent with the upstream Android implementation.</p> 2418 2419<h1 id="7_hardware_compatibility">7. Hardware Compatibility</h1> 2420 2421 2422<p>If a device includes a particular hardware component that has a corresponding 2423API for third-party developers, the device implementation MUST implement that 2424API as described in the Android SDK documentation. If an API in the SDK 2425interacts with a hardware component that is stated to be optional and the 2426device implementation does not possess that component:</p> 2427 2428<ul> 2429 <li>Complete class definitions (as documented by the SDK) for the component APIs 2430MUST still be presented. 2431 <li>The API’s behaviors MUST be implemented as no-ops in some reasonable fashion. 2432 <li>API methods MUST return null values where permitted by the SDK documentation. 2433 <li>API methods MUST return no-op implementations of classes where null values are 2434not permitted by the SDK documentation. 2435 <li>API methods MUST NOT throw exceptions not documented by the SDK documentation. 2436</ul> 2437 2438<p>A typical example of a scenario where these requirements apply is the telephony 2439API: even on non-phone devices, these APIs must be implemented as reasonable 2440no-ops.</p> 2441 2442<p>Device implementations MUST consistently report accurate hardware configuration 2443information via the getSystemAvailableFeatures() and hasSystemFeature(String) 2444methods on the android.content.pm.PackageManager class for the same build 2445fingerprint. [<a href="http://developer.android.com/reference/android/content/pm/PackageManager.html">Resources, 53]</a></p> 2446 2447<h2 id="7_1_display_and_graphics">7.1. Display and Graphics</h2> 2448 2449 2450<p>Android includes facilities that automatically adjust application assets and UI 2451layouts appropriately for the device, to ensure that third-party applications 2452run well on a variety of hardware configurations [<a href="http://developer.android.com/guide/practices/screens_support.html">Resources, 61</a>]. Devices MUST properly implement these APIs and behaviors, as detailed in 2453this section.</p> 2454 2455<p>The units referenced by the requirements in this section are defined as 2456follows:</p> 2457 2458<ul> 2459 <li><strong>physical diagonal size</strong>. The distance in inches between two opposing corners of the illuminated portion 2460of the display.</li> 2461 <li><strong>dots per inch (dpi)</strong>. The number of pixels encompassed by a linear horizontal or vertical span of 24621”. Where dpi values are listed, both horizontal and vertical dpi must fall 2463within the range.</li> 2464 <li><strong>aspect ratio</strong>. The ratio of the pixels of the longer dimension 2465 to the shorter dimension of the screen. For example, a display of 480x854 pixels 2466 would be 854/480 = 1.779, or roughly “16:9”.</li> 2467 <li><strong>density-independent pixel (dp)</strong> The virtual pixel unit normalized to a 160 dpi screen, calculated as: pixels = 2468dps * (density/160).</li> 2469</ul> 2470 2471<h3 id="7_1_1_screen_configuration">7.1.1. Screen Configuration</h3> 2472 2473 2474<h4 id="7_1_1_1_screen_size">7.1.1.1. Screen Size</h4> 2475 2476<div class="note"> 2477<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> 2478</div> 2479 2480<p>The Android UI framework supports a variety of different screen sizes, and 2481allows applications to query the device screen size (aka “screen layout") via 2482android.content.res.Configuration.screenLayout with the SCREENLAYOUT_SIZE_MASK. 2483Device implementations MUST report the correct screen size as defined in the 2484Android SDK documentation [<a href="http://developer.android.com/guide/practices/screens_support.html">Resources, 61</a>] and determined by the upstream Android platform. Specifically, device 2485implementations MUST report the correct screen size according to the following 2486logical density-independent pixel (dp) screen dimensions.</p> 2487 2488<ul> 2489 <li>Devices MUST have screen sizes of at least 426 dp x 320 dp (‘small’), unless it 2490is an Android Watch device.</li> 2491 <li>Devices that report screen size ‘normal’ MUST have screen sizes of at least 480 2492dp x 320 dp.</li> 2493 <li>Devices that report screen size ‘large’ MUST have screen sizes of at least 640 2494dp x 480 dp.</li> 2495 <li>Devices that report screen size ‘xlarge’ MUST have screen sizes of at least 960 2496dp x 720 dp.</li> 2497</ul> 2498 2499<p>In addition, </p> 2500 2501<ul> 2502 <li>Android Watch devices MUST have a screen with the physical diagonal size in the 2503range from 1.1 to 2.5 inches.</li> 2504 <li>Other types of Android device implementations, with a physically integrated 2505screen, MUST have a screen at least 2.5 inches in physical diagonal size.</li> 2506</ul> 2507 2508<p>Devices MUST NOT change their reported screen size at any time.</p> 2509 2510<p>Applications optionally indicate which screen sizes they support via the 2511<supports-screens> attribute in the AndroidManifest.xml file. Device 2512implementations MUST correctly honor applications' stated support for small, 2513normal, large, and xlarge screens, as described in the Android SDK 2514documentation.</p> 2515 2516<h4 id="7_1_1_2_screen_aspect_ratio">7.1.1.2. Screen Aspect Ratio</h4> 2517 2518<div class="note"> 2519<p>Android Watch devices MAY have an aspect ratio of 1.0 (1:1).</p> 2520</div> 2521 2522 2523<p>The screen aspect ratio MUST be a value from 1.3333 (4:3) to 1.86 (roughly 252416:9), but Android Watch devices MAY have an aspect ratio of 1.0 (1:1) because 2525such a device implementation will use a UI_MODE_TYPE_WATCH as the 2526android.content.res.Configuration.uiMode.</p> 2527 2528<h4 id="7_1_1_3_screen_density">7.1.1.3. Screen Density</h4> 2529 2530 2531<p>The Android UI framework defines a set of standard logical densities to help 2532application developers target application resources. Device implementations 2533MUST report only one of the following logical Android framework densities 2534through the android.util.DisplayMetrics APIs, and MUST execute applications at 2535this standard density and MUST NOT change the value at at any time for the 2536default display.</p> 2537 2538<ul> 2539 <li>120 dpi (ldpi)</li> 2540 <li>160 dpi (mdpi)</li> 2541 <li>213 dpi (tvdpi)</li> 2542 <li>240 dpi (hdpi)</li> 2543 <li>280 dpi (280dpi)</li> 2544 <li>320 dpi (xhdpi)</li> 2545 <li>400 dpi (400dpi)</li> 2546 <li>480 dpi (xxhdpi)</li> 2547 <li>560 dpi (560dpi)</li> 2548 <li>640 dpi (xxxhdpi)</li> 2549</ul> 2550 2551<p>Device implementations SHOULD define the standard Android framework density 2552that is numerically closest to the physical density of the screen, unless that 2553logical density pushes the reported screen size below the minimum supported. If 2554the standard Android framework density that is numerically closest to the 2555physical density results in a screen size that is smaller than the smallest 2556supported compatible screen size (320 dp width), device implementations SHOULD 2557report the next lowest standard Android framework density.</p> 2558 2559<h3 id="7_1_2_display_metrics">7.1.2. Display Metrics</h3> 2560 2561 2562<p>Device implementations MUST report correct values for all display metrics 2563defined in android.util.DisplayMetrics [<a href="http://developer.android.com/reference/android/util/DisplayMetrics.html">Resources, 62</a>] and MUST report the same values regardless of whether the embedded or 2564external screen is used as the default display.</p> 2565 2566<h3 id="7_1_3_screen_orientation">7.1.3. Screen Orientation</h3> 2567 2568 2569<p>Devices MUST report which screen orientations they support 2570(android.hardware.screen.portrait and/or android.hardware.screen.landscape) and 2571MUST report at least one supported orientation. For example, a device with a 2572fixed orientation landscape screen, such as a television or laptop, SHOULD only 2573report android.hardware.screen.landscape.</p> 2574 2575<p>Devices that report both screen orientations MUST support dynamic orientation 2576by applications to either portrait or landscape screen orientation. That is, 2577the device must respect the application’s request for a specific screen 2578orientation. Device implementations MAY select either portrait or landscape 2579orientation as the default.</p> 2580 2581<p>Devices MUST report the correct value for the device’s current orientation, 2582whenever queried via the android.content.res.Configuration.orientation, 2583android.view.Display.getOrientation(), or other APIs.</p> 2584 2585<p>Devices MUST NOT change the reported screen size or density when changing 2586orientation.</p> 2587 2588<h3 id="7_1_4_2d_and_3d_graphics_acceleration">7.1.4. 2D and 3D Graphics Acceleration</h3> 2589 2590 2591<p>Device implementations MUST support both OpenGL ES 1.0 and 2.0, as embodied and 2592detailed in the Android SDK documentations. Device implementations SHOULD 2593support OpenGL ES 3.0 or 3.1 on devices capable of supporting it. Device 2594implementations MUST also support Android RenderScript, as detailed in the 2595Android SDK documentation [<a href="http://developer.android.com/guide/topics/renderscript/">Resources, 63</a>].</p> 2596 2597<p>Device implementations MUST also correctly identify themselves as supporting 2598OpenGL ES 1.0, OpenGL ES 2.0, OpenGL ES 3.0 or OpenGL 3.1. That is:</p> 2599 2600<ul> 2601 <li>The managed APIs (such as via the GLES10.getString() method) MUST report support 2602for OpenGL ES 1.0 and OpenGL ES 2.0.</li> 2603 <li>The native C/C++ OpenGL APIs (APIs available to apps via libGLES_v1CM.so, 2604libGLES_v2.so, or libEGL.so) MUST report support for OpenGL ES 1.0 and OpenGL 2605ES 2.0.</li> 2606 <li>Device implementations that declare support for OpenGL ES 3.0 or 3.1 MUST 2607support the corresponding managed APIs and include support for native C/C++ 2608APIs. On device implementations that declare support for OpenGL ES 3.0 or 3.1, 2609libGLESv2.so MUST export the corresponding function symbols in addition to the 2610OpenGL ES 2.0 function symbols.</li> 2611</ul> 2612 2613<p>In addition to OpenGL ES 3.1, Android provides an extension pack with Java 2614interfaces [<a href="https://developer.android.com/reference/android/opengl/GLES31Ext.html">Resources, 64</a>] and native support for advanced graphics functionality such as tessellation 2615and the ASTC texture compression format. Android device implementations MAY 2616support this extension pack, and—only if fully implemented—MUST identify the 2617support through the android.hardware.opengles.aep feature flag.</p> 2618 2619<p>Also, device implementations MAY implement any desired OpenGL ES extensions. 2620However, device implementations MUST report via the OpenGL ES managed and 2621native APIs all extension strings that they do support, and conversely MUST NOT 2622report extension strings that they do not support.</p> 2623 2624<p>Note that Android includes support for applications to optionally specify that 2625they require specific OpenGL texture compression formats. These formats are 2626typically vendor-specific. Device implementations are not required by Android 2627to implement any specific texture compression format. However, they SHOULD 2628accurately report any texture compression formats that they do support, via the 2629getString() method in the OpenGL API.</p> 2630 2631<p>Android includes a mechanism for applications to declare that they want to 2632enable hardware acceleration for 2D graphics at the Application, Activity, 2633Window, or View level through the use of a manifest tag 2634android:hardwareAccelerated or direct API calls [<a href="http://developer.android.com/guide/topics/graphics/hardware-accel.html">Resources, 65</a>].</p> 2635 2636<p>Device implementations MUST enable hardware acceleration by default, and MUST 2637disable hardware acceleration if the developer so requests by setting 2638android:hardwareAccelerated="false” or disabling hardware acceleration directly 2639through the Android View APIs.</p> 2640 2641<p>In addition, device implementations MUST exhibit behavior consistent with the 2642Android SDK documentation on hardware acceleration [<a href="http://developer.android.com/guide/topics/graphics/hardware-accel.html">Resources, 65</a>].</p> 2643 2644<p>Android includes a TextureView object that lets developers directly integrate 2645hardware-accelerated OpenGL ES textures as rendering targets in a UI hierarchy. 2646Device implementations MUST support the TextureView API, and MUST exhibit 2647consistent behavior with the upstream Android implementation.</p> 2648 2649<p>Android includes support for EGL_ANDROID_RECORDABLE, an EGLConfig attribute 2650that indicates whether the EGLConfig supports rendering to an ANativeWindow 2651that records images to a video. Device implementations MUST support 2652EGL_ANDROID_RECORDABLE extension [<a href="https://www.khronos.org/registry/egl/extensions/ANDROID/EGL_ANDROID_recordable.txt">Resources, 66</a>].</p> 2653 2654<h3 id="7_1_5_legacy_application_compatibility_mode">7.1.5. Legacy Application Compatibility Mode</h3> 2655 2656 2657<p>Android specifies a “compatibility mode” in which the framework operates in a 2658'normal' screen size equivalent (320dp width) mode for the benefit of legacy 2659applications not developed for old versions of Android that pre-date 2660screen-size independence.</p> 2661 2662<ul> 2663<li>Android Automotive does not support legacy compatibility mode.</li> 2664<li>All other device implementations MUST include support for legacy application 2665compatibility mode as implemented by the upstream Android open source code. That 2666is, device implementations MUST NOT alter the triggers or thresholds at which 2667compatibility mode is activated, and MUST NOT alter the behavior of the 2668compatibility mode itself.</li> 2669</ul> 2670 2671<h3 id="7_1_6_screen_technology">7.1.6. Screen Technology</h3> 2672 2673 2674<p>The Android platform includes APIs that allow applications to render rich 2675graphics to the display. Devices MUST support all of these APIs as defined by 2676the Android SDK unless specifically allowed in this document. </p> 2677 2678<ul> 2679 <li>Devices MUST support displays capable of rendering 16-bit color graphics and 2680SHOULD support displays capable of 24-bit color graphics.</li> 2681 <li>Devices MUST support displays capable of rendering animations.</li> 2682 <li>The display technology used MUST have a pixel aspect ratio (PAR) between 0.9 2683and 1.15. That is, the pixel aspect ratio MUST be near square (1.0) with a 10 ~ 268415% tolerance.</li> 2685</ul> 2686 2687<h3 id="7_1_7_external_displays">7.1.7. Secondary Displays</h3> 2688 2689 2690<p>Android includes support for secondary display to enable media sharing 2691capabilities and developer APIs for accessing external displays. If a device 2692supports an external display either via a wired, wireless, or an embedded 2693additional display connection then the device implementation MUST implement the 2694display manager API as described in the Android SDK documentation [<a href="http://developer.android.com/reference/android/hardware/display/DisplayManager.html">Resources, 67</a>].</p> 2695 2696<h2 id="7_2_input_devices">7.2. Input Devices</h2> 2697 2698<p>Devices MUST support a touchscreen or meet the requirements listed in 7.2.2 2699for non-touch navigation.</p> 2700 2701<h3 id="7_2_1_keyboard">7.2.1. Keyboard</h3> 2702 2703<div class="note"> 2704<p>Android Watch and Android Automotive implementations MAY implement a soft 2705keyboard. All other device implementations MUST implement a soft keyboard and:</p> 2706</div> 2707 2708 2709<p>Device implementations:</p> 2710 2711<ul> 2712 <li>MUST include support for the Input Management Framework (which allows 2713third-party developers to create Input Method Editors—i.e. soft keyboard) as 2714detailed at <a href="http://developer.android.com">http://developer.android.com</a>.</li> 2715 <li>MUST provide at least one soft keyboard implementation (regardless of whether a 2716hard keyboard is present) except for Android Watch devices where the screen 2717size makes it less reasonable to have a soft keyboard.</li> 2718 <li>MAY include additional soft keyboard implementations.</li> 2719 <li>MAY include a hardware keyboard.</li> 2720 <li>MUST NOT include a hardware keyboard that does not match one of the formats 2721specified in android.content.res.Configuration.keyboard [<a href="http://developer.android.com/reference/android/content/res/Configuration.html">Resources, 68</a>] (QWERTY or 12-key).</li> 2722</ul> 2723 2724<h3 id="7_2_2_non-touch_navigation">7.2.2. Non-touch Navigation</h3> 2725 2726<div class="note"> 2727<p>Android Television devices MUST support D-pad.</p> 2728</div> 2729 2730<p>Device implementations:</p> 2731 2732<ul> 2733 <li>MAY omit a non-touch navigation option (trackball, d-pad, or wheel) if the 2734device implementation is not an Android Television device.</li> 2735 <li>MUST report the correct value for android.content.res.Configuration.navigation 2736[<a href="http://developer.android.com/reference/android/content/res/Configuration.html">Resources, 68</a>].</li> 2737 <li>MUST provide a reasonable alternative user interface mechanism for the 2738selection and editing of text, compatible with Input Management Engines. The 2739upstream Android open source implementation includes a selection mechanism 2740suitable for use with devices that lack non-touch navigation inputs.</li> 2741</ul> 2742 2743<h3 id="7_2_3_navigation_keys">7.2.3. Navigation Keys</h3> 2744 2745<div class="note"> 2746<p>The availability and visibility requirement of the Home, Recents, and Back 2747functions differ between device types as described in this section.</p> 2748</div> 2749 2750<p>The Home, Recents, and Back functions (mapped to the key events KEYCODE_HOME, 2751KEYCODE_APP_SWITCH, KEYCODE_BACK, respectively) are essential to the Android 2752navigation paradigm and therefore:</p> 2753 2754<ul> 2755 <li>Android Handheld device implementations MUST provide the Home, Recents, and 2756Back functions.</li> 2757 <li>Android Television device implementations MUST provide the Home and Back 2758functions.</li> 2759 <li>Android Watch device implementations MUST have the Home function available to 2760the user, and the Back function except for when it is in UI_MODE_TYPE_WATCH.</li> 2761 <li>Android Automotive implementations MUST provide the Home function and MAY 2762provide Back and Recent functions.</li> 2763 <li>All other types of device implementations MUST provide the Home and Back 2764functions.</li> 2765</ul> 2766 2767<p>These functions MAY be implemented via dedicated physical buttons (such as 2768mechanical or capacitive touch buttons), or MAY be implemented using dedicated 2769software keys on a distinct portion of the screen, gestures, touch panel, etc. 2770Android supports both implementations. All of these functions MUST be 2771accessible with a single action (e.g. tap, double-click or gesture) when 2772visible.</p> 2773 2774<p>Recents function, if provided, MUST have a visible button or icon unless hidden 2775together with other navigation functions in full-screen mode. This does not 2776apply to devices upgrading from earlier Android versions that have physical 2777buttons for navigation and no recents key.</p> 2778 2779<p> The Home and Back functions, if provided, MUST each have a visible button or 2780icon unless hidden together with other navigation functions in full-screen mode 2781or when the uiMode UI_MODE_TYPE_MASK is set to UI_MODE_TYPE_WATCH.</p> 2782 2783<p>The Menu function is deprecated in favor of action bar since Android 4.0. 2784Therefore the new device implementations shipping with Android 5.0 and later MUST NOT 2785implement a dedicated physical button for the Menu function. Older device 2786implementations SHOULD NOT implement a dedicated physical button for the Menu 2787function, but if the physical Menu button is implemented and the device is 2788running applications with targetSdkVersion > 10, the device implementation:</p> 2789 2790<ul> 2791 <li>MUST display the action overflow button on the action bar when it is visible 2792and the resulting action overflow menu popup is not empty. For a device 2793implementation launched before Android 4.4 but upgrading to Android 5.1, this 2794is RECOMMENDED.</li> 2795 <li>MUST NOT modify the position of the action overflow popup displayed by 2796selecting the overflow button in the action bar.</li> 2797 <li>MAY render the action overflow popup at a modified position on the screen when 2798it is displayed by selecting the physical menu button.</li> 2799</ul> 2800 2801<p>For backwards compatibility, device implementations MUST make the Menu function 2802available to applications when targetSdkVersion is less than 10, either by a physical 2803button, a software key, or gestures. This Menu function should be presented 2804unless hidden together with other navigation functions.</p> 2805 2806<p>Android supports Assist action [<a href="http://developer.android.com/reference/android/content/Intent.html#ACTION_ASSIST">Resources, 69</a>]. Android device implementations except for Android Watch devices MUST make 2807the Assist action available to the user at all times when running applications. 2808The Assist action SHOULD be implemented as a long-press on the Home button or a 2809swipe-up gesture on the software Home key. This function MAY be implemented via 2810another physical button, software key, or gesture, but MUST be accessible with 2811a single action (e.g. tap, double-click, or gesture) when other navigation keys 2812are visible.</p> 2813 2814<p>Device implementations MAY use a distinct portion of the screen to display the 2815navigation keys, but if so, MUST meet these requirements:</p> 2816 2817<ul> 2818 <li>Device implementation navigation keys MUST use a distinct portion of the 2819screen, not available to applications, and MUST NOT obscure or otherwise 2820interfere with the portion of the screen available to applications.</li> 2821 <li>Device implementations MUST make available a portion of the display to 2822applications that meets the requirements defined in <a href="#7_1_1_screen_configuration">section 7.1.1</a>.</li> 2823 <li>Device implementations MUST display the navigation keys when applications do 2824not specify a system UI mode, or specify SYSTEM_UI_FLAG_VISIBLE.</li> 2825 <li>Device implementations MUST present the navigation keys in an unobtrusive “low 2826profile” (eg. dimmed) mode when applications specify 2827SYSTEM_UI_FLAG_LOW_PROFILE.</li> 2828 <li>Device implementations MUST hide the navigation keys when applications specify 2829SYSTEM_UI_FLAG_HIDE_NAVIGATION.</li> 2830</ul> 2831 2832<h3 id="7_2_4_touchscreen_input">7.2.4. Touchscreen Input</h3> 2833 2834<div class="note"> 2835<p>Android Handhelds and Watch Devices MUST support touchscreen input.</p> 2836</div> 2837 2838 2839<p>Device implementations SHOULD have a pointer input system of some kind (either 2840mouse-like or touch). However, if a device implementation does not support a 2841pointer input system, it MUST NOT report the android.hardware.touchscreen or 2842android.hardware.faketouch feature constant. Device implementations that do 2843include a pointer input system:</p> 2844 2845<ul> 2846 <li>SHOULD support fully independently tracked pointers, if the device input system 2847supports multiple pointers.</li> 2848 <li>MUST report the value of android.content.res.Configuration.touchscreen [<a href="http://developer.android.com/reference/android/content/res/Configuration.html">Resources, 68</a>] corresponding to the type of the specific touchscreen on the device.</li> 2849</ul> 2850 2851<p>Android includes support for a variety of touchscreens, touch pads, and fake 2852touch input devices. Touchscreen based device implementations are associated 2853with a display [<a href="http://source.android.com/devices/tech/input/touch-devices.html">Resources, 70</a>] such that the user has the impression of directly manipulating items on 2854screen. Since the user is directly touching the screen, the system does not 2855require any additional affordances to indicate the objects being manipulated. 2856In contrast, a fake touch interface provides a user input system that 2857approximates a subset of touchscreen capabilities. For example, a mouse or 2858remote control that drives an on-screen cursor approximates touch, but requires 2859the user to first point or focus then click. Numerous input devices like the 2860mouse, trackpad, gyro-based air mouse, gyro-pointer, joystick, and multi-touch 2861trackpad can support fake touch interactions. Android includes the feature 2862constant android.hardware.faketouch, which corresponds to a high-fidelity 2863non-touch (pointer-based) input device such as a mouse or trackpad that can 2864adequately emulate touch-based input (including basic gesture support), and 2865indicates that the device supports an emulated subset of touchscreen 2866functionality. Device implementations that declare the fake touch feature MUST 2867meet the fake touch requirements in <a href="#7_2_5_fake_touch_input">section 7.2.5</a>.</p> 2868 2869<p>Device implementations MUST report the correct feature corresponding to the 2870type of input used. Device implementations that include a touchscreen 2871(single-touch or better) MUST report the platform feature constant 2872android.hardware.touchscreen. Device implementations that report the platform 2873feature constant android.hardware.touchscreen MUST also report the platform 2874feature constant android.hardware.faketouch. Device implementations that do not 2875include a touchscreen (and rely on a pointer device only) MUST NOT report any 2876touchscreen feature, and MUST report only android.hardware.faketouch if they 2877meet the fake touch requirements in <a href="#7_2_5_fake_touch_input">section 7.2.5</a>.</p> 2878 2879<h3 id="7_2_5_fake_touch_input">7.2.5. Fake Touch Input</h3> 2880 2881 2882<p>Device implementations that declare support for android.hardware.faketouch:</p> 2883 2884<ul> 2885 <li>MUST report the absolute X and Y screen positions of the pointer location and 2886display a visual pointer on the screen [<a href="http://developer.android.com/reference/android/view/MotionEvent.html">Resources, 71</a>].</li> 2887 <li>MUST report touch event with the action code that specifies the state change 2888that occurs on the pointer going down or up on the screen [<a href="http://developer.android.com/reference/android/view/MotionEvent.html">Resources, 71</a>].</li> 2889 <li>MUST support pointer down and up on an object on the screen, which allows users 2890to emulate tap on an object on the screen.</li> 2891 <li>MUST support pointer down, pointer up, pointer down then pointer up in the same 2892place on an object on the screen within a time threshold, which allows users to 2893emulate double tap on an object on the screen [<a href="http://developer.android.com/reference/android/view/MotionEvent.html">Resources, 71</a>].</li> 2894 <li>MUST support pointer down on an arbitrary point on the screen, pointer move to 2895any other arbitrary point on the screen, followed by a pointer up, which allows 2896users to emulate a touch drag.</li> 2897 <li>MUST support pointer down then allow users to quickly move the object to a 2898different position on the screen and then pointer up on the screen, which 2899allows users to fling an object on the screen.</li> 2900</ul> 2901 2902<p>Devices that declare support for android.hardware.faketouch.multitouch.distinct 2903MUST meet the requirements for faketouch above, and MUST also support distinct 2904tracking of two or more independent pointer inputs.</p> 2905 2906<h3 id="7_2_6_game_controller_support">7.2.6. Game Controller Support</h3> 2907 2908 2909<p>Android Television device implementations MUST support button mappings for game 2910controllers as listed below. The upstream Android implementation includes 2911implementation for game controllers that satisfies this requirement. </p> 2912 2913<h4 id="7_2_6_1_button_mappings">7.2.6.1. Button Mappings</h4> 2914 2915 2916<p>Android Television device implementations MUST support the following key 2917mappings:</p> 2918<table> 2919 <tr> 2920 <th>Button</th> 2921 <th>HID Usage</strong><sup>2</sup></td> 2922 <th>Android Button</th> 2923 </tr> 2924 <tr> 2925 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BUTTON_A">A</a><sup>1</sup></td> 2926 <td>0x09 0x0001</td> 2927 <td>KEYCODE_BUTTON_A (96)</td> 2928 </tr> 2929 <tr> 2930 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BUTTON_B">B</a><sup>1</sup></td> 2931 <td>0x09 0x0002</td> 2932 <td>KEYCODE_BUTTON_B (97)</td> 2933 </tr> 2934 <tr> 2935 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BUTTON_X">X</a><sup>1</sup></td> 2936 <td>0x09 0x0004</td> 2937 <td>KEYCODE_BUTTON_X (99)</td> 2938 </tr> 2939 <tr> 2940 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BUTTON_Y">Y</a><sup>1</sup></td> 2941 <td>0x09 0x0005</td> 2942 <td>KEYCODE_BUTTON_Y (100)</td> 2943 </tr> 2944 <tr> 2945 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_DPAD_UP">D-pad up</a><sup>1</sup></p> 2946 2947<p><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_DPAD_DOWN">D-pad down</a><sup>1</sup></td> 2948 <td>0x01 0x0039<sup>3</sup></td> 2949 <td><a href="http://developer.android.com/reference/android/view/MotionEvent.html#AXIS_HAT_Y">AXIS_HAT_Y</a><sup>4</sup></td> 2950 </tr> 2951 <tr> 2952 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_DPAD_LEFT">D-pad left</a>1</p> 2953 2954<p><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_DPAD_RIGHT">D-pad right</a><sup>1</sup></td> 2955 <td>0x01 0x0039<sup>3</sup></td> 2956 <td><a href="http://developer.android.com/reference/android/view/MotionEvent.html#AXIS_HAT_X">AXIS_HAT_X</a><sup>4</sup></td> 2957 </tr> 2958 <tr> 2959 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BUTTON_L1">Left shoulder button</a><sup>1</sup></td> 2960 <td>0x09 0x0007</td> 2961 <td>KEYCODE_BUTTON_L1 (102)</td> 2962 </tr> 2963 <tr> 2964 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BUTTON_R1">Right shoulder button</a><sup>1</sup></td> 2965 <td>0x09 0x0008</td> 2966 <td>KEYCODE_BUTTON_R1 (103)</td> 2967 </tr> 2968 <tr> 2969 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BUTTON_THUMBL">Left stick click</a><sup>1</sup></td> 2970 <td>0x09 0x000E</td> 2971 <td>KEYCODE_BUTTON_THUMBL (106)</td> 2972 </tr> 2973 <tr> 2974 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BUTTON_THUMBR">Right stick click</a><sup>1</sup></td> 2975 <td>0x09 0x000F</td> 2976 <td>KEYCODE_BUTTON_THUMBR (107)</td> 2977 </tr> 2978 <tr> 2979 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_HOME">Home</a><sup>1</sup></td> 2980 <td>0x0c 0x0223</td> 2981 <td>KEYCODE_HOME (3)</td> 2982 </tr> 2983 <tr> 2984 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BACK">Back</a><sup>1</sup></td> 2985 <td>0x0c 0x0224</td> 2986 <td>KEYCODE_BACK (4)</td> 2987 </tr> 2988</table> 2989 2990 2991<p class="table_footnote">1 [<a href="http://developer.android.com/reference/android/view/KeyEvent.html">Resources, 72</a>]</p> 2992 2993<p class="table_footnote">2 The above HID usages must be declared within a Game pad CA (0x01 0x0005).</p> 2994 2995<p class="table_footnote">3 This usage must have a Logical Minimum of 0, a Logical Maximum of 7, a 2996Physical Minimum of 0, a Physical Maximum of 315, Units in Degrees, and a 2997Report Size of 4. The logical value is defined to be the clockwise rotation 2998away from the vertical axis; for example, a logical value of 0 represents no 2999rotation and the up button being pressed, while a logical value of 1 represents 3000a rotation of 45 degrees and both the up and left keys being pressed.</p> 3001 3002<p class="table_footnote">4 [<a href="http://developer.android.com/reference/android/view/MotionEvent.html">Resources, 71</a>]</p> 3003 3004<table> 3005 <tr> 3006 <th>Analog Controls</strong><sup>1</sup></td> 3007 <th>HID Usage</th> 3008 <th>Android Button</th> 3009 </tr> 3010 <tr> 3011 <td><a href="http://developer.android.com/reference/android/view/MotionEvent.html#AXIS_LTRIGGER">Left Trigger</a></td> 3012 <td>0x02 0x00C5</td> 3013 <td>AXIS_LTRIGGER </td> 3014 </tr> 3015 <tr> 3016 <td><a href="http://developer.android.com/reference/android/view/MotionEvent.html#AXIS_THROTTLE">Right Trigger</a></td> 3017 <td>0x02 0x00C4</td> 3018 <td>AXIS_RTRIGGER </td> 3019 </tr> 3020 <tr> 3021 <td><a href="http://developer.android.com/reference/android/view/MotionEvent.html#AXIS_Y">Left Joystick</a></td> 3022 <td>0x01 0x0030</p> 3023 3024<p>0x01 0x0031</td> 3025 <td>AXIS_X</p> 3026 3027<p>AXIS_Y</td> 3028 </tr> 3029 <tr> 3030 <td><a href="http://developer.android.com/reference/android/view/MotionEvent.html#AXIS_Z">Right Joystick</a></td> 3031 <td>0x01 0x0032</p> 3032 3033<p>0x01 0x0035</td> 3034 <td>AXIS_Z</p> 3035 3036<p>AXIS_RZ</td> 3037 </tr> 3038</table> 3039 3040 3041<p class="table_footnote">1 [<a href="http://developer.android.com/reference/android/view/MotionEvent.html">Resources, 71</a>]</p> 3042 3043<h3 id="7_2_7_remote_control">7.2.7. Remote Control</h3> 3044 3045 3046<p>Android Television device implementations SHOULD provide a remote control to 3047allow users to access the TV interface. The remote control MAY be a physical 3048remote or can be a software-based remote that is accessible from a mobile phone 3049or tablet. The remote control MUST meet the requirements defined below.</p> 3050 3051<ul> 3052 <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> 3053 <li><strong>Navigation</strong>. All Android Television remotes MUST include Back, Home, and Select buttons and 3054support for D-pad events [<a href="http://developer.android.com/reference/android/view/KeyEvent.html">Resources, 72</a>].</li> 3055</ul> 3056 3057<h2 id="7_3_sensors">7.3. Sensors</h2> 3058 3059 3060<p>Android includes APIs for accessing a variety of sensor types. Devices 3061implementations generally MAY omit these sensors, as provided for in the 3062following subsections. If a device includes a particular sensor type that has a 3063corresponding API for third-party developers, the device implementation MUST 3064implement that API as described in the Android SDK documentation and the 3065Android Open Source documentation on sensors [<a href="http://source.android.com/devices/sensors/">Resources, 73</a>]. For example, device implementations:</p> 3066 3067<ul> 3068 <li>MUST accurately report the presence or absence of sensors per the 3069android.content.pm.PackageManager class [<a href="http://developer.android.com/reference/android/content/pm/PackageManager.html">Resources, 53]</a>.</li> 3070 <li>MUST return an accurate list of supported sensors via the 3071SensorManager.getSensorList() and similar methods.</li> 3072 <li>MUST behave reasonably for all other sensor APIs (for example, by returning 3073true or false as appropriate when applications attempt to register listeners, 3074not calling sensor listeners when the corresponding sensors are not present; 3075etc.).</li> 3076 <li>MUST report all sensor measurements using the relevant International System of 3077Units (metric) values for each sensor type as defined in the Android SDK 3078documentation [<a href="http://developer.android.com/reference/android/hardware/SensorEvent.html">Resources, 74</a>].</li> 3079 <li>SHOULD report the event time in nanoseconds as defined in the Android SDK 3080documentation, representing the time the event happened and synchronized with 3081the SystemClock.elapsedRealtimeNano() clock. Existing and new Android devices 3082are <strong>very strongly encouraged</strong> to meet these requirement so they will be able to upgrade to the future 3083platform releases where this might become a REQUIRED component. The 3084synchronization error SHOULD be below 100 milliseconds [<a href="http://developer.android.com/reference/android/hardware/SensorEvent.html#timestamp">Resources, 75</a>].</li> 3085</ul> 3086 3087<p>The list above is not comprehensive; the documented behavior of the Android SDK 3088and the Android Open Source Documentations on Sensors [<a href="http://source.android.com/devices/sensors/">Resources, 73</a>] is to be considered authoritative.</p> 3089 3090<p>Some sensor types are composite, meaning they can be derived from data provided 3091by one or more other sensors. (Examples include the orientation sensor, and the 3092linear acceleration sensor.) Device implementations SHOULD implement these 3093sensor types, when they include the prerequisite physical sensors as described 3094in [<a href="https://source.android.com/devices/sensors/sensor-types.html">Resources, 76</a>]. 3095If a device implementation includes a composite sensor it MUST implement the 3096sensor as described in the Android Open Source documentation on composite 3097sensors [<a href="https://source.android.com/devices/sensors/sensor-types.html#composite_sensor_type_summary">Resources, 76</a>].</p> 3098 3099<p>Some Android sensors support a “continuous” trigger mode, which returns data 3100continuously [<a href="https://source.android.com/devices/sensors/report-modes.html#continuous">Resources, 77</a>]. For any API indicated by the Android SDK documentation to be a continuous 3101sensor, device implementations MUST continuously provide periodic data samples 3102that SHOULD have a jitter below 3%, where jitter is defined as the standard 3103deviation of the difference of the reported timestamp values between 3104consecutive events.</p> 3105 3106<p>Note that the device implementations MUST ensure that the sensor event stream 3107MUST NOT prevent the device CPU from entering a suspend state or waking up from 3108a suspend state.</p> 3109 3110<p>Finally, when several sensors are activated, the power consumption SHOULD NOT 3111exceed the sum of the individual sensor’s reported power consumption.</p> 3112 3113<h3 id="7_3_1_accelerometer">7.3.1. Accelerometer</h3> 3114 3115 3116<p>Device implementations SHOULD include a 3-axis accelerometer. Android Handheld 3117devices and Android Watch devices are strongly encouraged to include this 3118sensor. If a device implementation does include a 3-axis accelerometer, it:</p> 3119 3120<ul> 3121 <li>MUST implement and report TYPE_ACCELEROMETER sensor [<a href="http://developer.android.com/reference/android/hardware/Sensor.html#TYPE_ACCELEROMETER">Resources, 78</a>].</li> 3122 <li>MUST be able to report events up to a frequency of at least 50 Hz for 3123 Android Watch devices as such devices have a stricter power constraint and 3124 100 Hz for all other device types.</li> 3125 <li>SHOULD report events up to at least 200 Hz.</li> 3126 <li>MUST comply with the Android sensor coordinate system as detailed in the 3127Android APIs [<a href="http://developer.android.com/reference/android/hardware/SensorEvent.html">Resources, 74</a>].</li> 3128 <li>MUST be capable of measuring from freefall up to four times the gravity (4g) or 3129more on any axis.</li> 3130 <li>MUST have a resolution of at least 8-bits and SHOULD have a resolution of at 3131least 16-bits.</li> 3132 <li>SHOULD be calibrated while in use if the characteristics changes over the life 3133cycle and compensated, and preserve the compensation parameters between device 3134reboots.</li> 3135 <li>SHOULD be temperature compensated.</li> 3136 <li>MUST have a standard deviation no greater than 0.05 m/s^, where the standard 3137deviation should be calculated on a per axis basis on samples collected over a 3138period of at least 3 seconds at the fastest sampling rate.</li> 3139 <li>SHOULD implement the TYPE_SIGNIFICANT_MOTION, TYPE_TILT_DETECTOR, 3140TYPE_STEP_DETECTOR, TYPE_STEP_COUNTER composite sensors as described in the 3141Android SDK document. Existing and new Android devices are <strong>very strongly encouraged</strong> to implement the TYPE_SIGNIFICANT_MOTION composite sensor. If any of these 3142sensors are implemented, the sum of their power consumption MUST always be less 3143than 4 mW and SHOULD each be below 2 mW and 0.5 mW for when the device is in a 3144dynamic or static condition.</li> 3145 <li>If a gyroscope sensor is included, MUST implement the TYPE_GRAVITY and 3146TYPE_LINEAR_ACCELERATION composite sensors and SHOULD implement the 3147TYPE_GAME_ROTATION_VECTOR composite sensor. Existing and new Android devices 3148are strongly encouraged to implement the TYPE_GAME_ROTATION_VECTOR sensor.</li> 3149 <li>SHOULD implement a TYPE_ROTATION_VECTOR composite sensor, if a gyroscope sensor 3150and a magnetometer sensor is also included.</li> 3151</ul> 3152 3153<h3 id="7_3_2_magnetometer">7.3.2. Magnetometer</h3> 3154 3155 3156<p>Device implementations SHOULD include a 3-axis magnetometer (compass). If a 3157device does include a 3-axis magnetometer, it:</p> 3158 3159<ul> 3160 <li>MUST implement the TYPE_MAGNETIC_FIELD sensor and SHOULD also implement 3161TYPE_MAGNETIC_FIELD_UNCALIBRATED sensor. Existing and new Android devices are 3162strongly encouraged to implement the TYPE_MAGNETIC_FIELD_UNCALIBRATED sensor.</li> 3163 <li>MUST be able to report events up to a frequency of at least 10 Hz and SHOULD 3164report events up to at least 50 Hz.</li> 3165 <li>MUST comply with the Android sensor coordinate system as detailed in the 3166Android APIs [<a href="http://developer.android.com/reference/android/hardware/SensorEvent.html">Resources, 74</a>].</li> 3167 <li>MUST be capable of measuring between -900 µT and +900 µT on each axis before 3168saturating.</li> 3169 <li>MUST have a hard iron offset value less than 700 µT and SHOULD have a value 3170below 200 µT, by placing the magnetometer far from dynamic (current-induced) 3171and static (magnet-induced) magnetic fields.</li> 3172 <li>MUST have a resolution equal or denser than 0.6 µT and SHOULD have a resolution 3173equal or denser than 0.2 µ.</li> 3174 <li>SHOULD be temperature compensated.</li> 3175 <li>MUST support online calibration and compensation of the hard iron bias, and 3176preserve the compensation parameters between device reboots.</li> 3177 <li>MUST have the soft iron compensation applied—the calibration can be done either 3178while in use or during the production of the device.</li> 3179 <li>SHOULD have a standard deviation, calculated on a per axis basis on samples 3180collected over a period of at least 3 seconds at the fastest sampling rate, no 3181greater than 0.5 µT.</li> 3182 <li>SHOULD implement a TYPE_ROTATION_VECTOR composite sensor, if an accelerometer 3183sensor and a gyroscope sensor is also included.</li> 3184 <li>MAY implement the TYPE_GEOMAGNETIC_ROTATION_VECTOR sensor if an accelerometer 3185sensor is also implemented. However if implemented, it MUST consume less than 318610 mW and SHOULD consume less than 3 mW when the sensor is registered for batch 3187mode at 10 Hz.</li> 3188</ul> 3189 3190<h3 id="7_3_3_gps">7.3.3. GPS</h3> 3191 3192 3193<p>Device implementations SHOULD include a GPS receiver. If a device 3194implementation does include a GPS receiver, it SHOULD include some form of“assisted GPS” technique to minimize GPS lock-on time.</p> 3195 3196<h3 id="7_3_4_gyroscope">7.3.4. Gyroscope</h3> 3197 3198 3199<p>Device implementations SHOULD include a gyroscope (angular change sensor). 3200Devices SHOULD NOT include a gyroscope sensor unless a 3-axis accelerometer is 3201also included. If a device implementation includes a gyroscope, it:</p> 3202 3203<ul> 3204 <li>MUST implement the TYPE_GYROSCOPE sensor and SHOULD also implement 3205TYPE_GYROSCOPE_UNCALIBRATED sensor. Existing and new Android devices are 3206strongly encouraged to implement the SENSOR_TYPE_GYROSCOPE_UNCALIBRATED sensor.</li> 3207 <li>MUST be capable of measuring orientation changes up to 1,000 degrees per second.</li> 3208 <li>MUST be able to report events up to a frequency of at least 50 Hz for 3209 Android Watch devices as such devices have a stricter power constraint and 3210 100 Hz for all other device types.</li> 3211 <li>SHOULD report events up to at least 200 Hz.</li> 3212 <li>MUST have a resolution of 12-bits or more and SHOULD have a resolution of 321316-bits or more.</li> 3214 <li>MUST be temperature compensated.</li> 3215 <li>MUST be calibrated and compensated while in use, and preserve the compensation 3216parameters between device reboots.</li> 3217 <li>MUST have a variance no greater than 1e-7 rad^2 / s^2 per Hz (variance per Hz, 3218or rad^2 / s). The variance is allowed to vary with the sampling rate, but must 3219be constrained by this value. In other words, if you measure the variance of 3220the gyro at 1 Hz sampling rate it should be no greater than 1e-7 rad^2/s^2.</li> 3221 <li>SHOULD implement a TYPE_ROTATION_VECTOR composite sensor, if an accelerometer 3222sensor and a magnetometer sensor is also included.</li> 3223 <li>If an accelerometer sensor is included, MUST implement the TYPE_GRAVITY and 3224TYPE_LINEAR_ACCELERATION composite sensors and SHOULD implement the 3225TYPE_GAME_ROTATION_VECTOR composite sensor. Existing and new Android devices 3226are strongly encouraged to implement the TYPE_GAME_ROTATION_VECTOR sensor.</li> 3227</ul> 3228 3229<h3 id="7_3_5_barometer">7.3.5. Barometer</h3> 3230 3231 3232<p>Device implementations SHOULD include a barometer (ambient air pressure 3233sensor). If a device implementation includes a barometer, it:</p> 3234 3235<ul> 3236 <li>MUST implement and report TYPE_PRESSURE sensor.</li> 3237 <li>MUST be able to deliver events at 5 Hz or greater.</li> 3238 <li>MUST have adequate precision to enable estimating altitude.</li> 3239 <li>MUST be temperature compensated.</li> 3240</ul> 3241 3242<h3 id="7_3_6_thermometer">7.3.6. Thermometer</h3> 3243 3244 3245<p>Device implementations MAY include an ambient thermometer (temperature sensor). 3246If present, it MUST be defined as SENSOR_TYPE_AMBIENT_TEMPERATURE and it MUST 3247measure the ambient (room) temperature in degrees Celsius.</p> 3248 3249<p>Device implementations MAY but SHOULD NOT include a CPU temperature sensor. If 3250present, it MUST be defined as SENSOR_TYPE_TEMPERATURE, it MUST measure the 3251temperature of the device CPU, and it MUST NOT measure any other temperature. 3252Note the SENSOR_TYPE_TEMPERATURE sensor type was deprecated in Android 4.0.</p> 3253 3254<h3 id="7_3_7_photometer">7.3.7. Photometer</h3> 3255 3256 3257<p>Device implementations MAY include a photometer (ambient light sensor).</p> 3258 3259<h3 id="7_3_8_proximity_sensor">7.3.8. Proximity Sensor</h3> 3260 3261 3262<p>Device implementations MAY include a proximity sensor. Devices that can make a 3263voice call and indicate any value other than PHONE_TYPE_NONE in getPhoneType 3264SHOULD include a proximity sensor. If a device implementation does include a 3265proximity sensor, it:</p> 3266 3267<ul> 3268 <li>MUST measure the proximity of an object in the same direction as the screen. 3269That is, the proximity sensor MUST be oriented to detect objects close to the 3270screen, as the primary intent of this sensor type is to detect a phone in use 3271by the user. If a device implementation includes a proximity sensor with any 3272other orientation, it MUST NOT be accessible through this API.</li> 3273 <li>MUST have 1-bit of accuracy or more.</li> 3274</ul> 3275 3276<h2 id="7_4_data_connectivity">7.4. Data Connectivity</h2> 3277 3278 3279<h3 id="7_4_1_telephony">7.4.1. Telephony</h3> 3280 3281 3282<p>“Telephony” as used by the Android APIs and this document refers specifically 3283to hardware related to placing voice calls and sending SMS messages via a GSM 3284or CDMA network. While these voice calls may or may not be packet-switched, 3285they are for the purposes of Android considered independent of any data 3286connectivity that may be implemented using the same network. In other words, 3287the Android “telephony” functionality and APIs refer specifically to voice 3288calls and SMS. For instance, device implementations that cannot place calls or 3289send/receive SMS messages MUST NOT report the android.hardware.telephony 3290feature or any subfeatures, regardless of whether they use a cellular network 3291for data connectivity.</p> 3292 3293<p>Android MAY be used on devices that do not include telephony hardware. That is, 3294Android is compatible with devices that are not phones. However, if a device 3295implementation does include GSM or CDMA telephony, it MUST implement full 3296support for the API for that technology. Device implementations that do not 3297include telephony hardware MUST implement the full APIs as no-ops.</p> 3298 3299<h3 id="7_4_2_ieee_802_11_wi-fi">7.4.2. IEEE 802.11 (Wi-Fi)</h3> 3300 3301<div class="note"> 3302<p>Android Television device implementations MUST include Wi-Fi support.</p> 3303</div> 3304 3305 3306<p>Android Television device implementations MUST include support for one or more 3307forms of 802.11 (b/g/a/n, etc.) and other types of Android device 3308implementation SHOULD include support for one or more forms of 802.11. If a 3309device implementation does include support for 802.11 and exposes the 3310functionality to a third-party application, it MUST implement the corresponding 3311Android API and:</p> 3312 3313<ul> 3314 <li>MUST report the hardware feature flag android.hardware.wifi.</li> 3315 <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, 79</a>].</li> 3316 <li>MUST support multicast DNS (mDNS) and MUST NOT filter mDNS packets 3317(224.0.0.251) at any time of operation including when the screen is not in an 3318active state.</li> 3319</ul> 3320 3321<h4 id="7_4_2_1_wi-fi_direct">7.4.2.1. Wi-Fi Direct</h4> 3322 3323 3324<p>Device implementations SHOULD include support for Wi-Fi Direct (Wi-Fi 3325peer-to-peer). If a device implementation does include support for Wi-Fi 3326Direct, it MUST implement the corresponding Android API as described in the SDK 3327documentation [<a href="http://developer.android.com/reference/android/net/wifi/p2p/WifiP2pManager.html">Resources, 80</a>]. If a device implementation includes support for Wi-Fi Direct, then it:</p> 3328 3329<ul> 3330 <li>MUST report the hardware feature android.hardware.wifi.direct.</li> 3331 <li>MUST support regular Wi-Fi operation.</li> 3332 <li>SHOULD support concurrent Wi-Fi and Wi-Fi Direct operation.</li> 3333</ul> 3334 3335<h4 id="7_4_2_2_wi-fi_tunneled_direct_link_setup">7.4.2.2. Wi-Fi Tunneled Direct Link Setup</h4> 3336 3337<div class="note"> 3338<p>Android Television device implementations MUST include support for Wi-Fi 3339Tunneled Direct Link Setup (TDLS).</p> 3340</div> 3341 3342 3343<p>Android Television device implementations MUST include support for Wi-Fi 3344Tunneled Direct Link Setup (TDLS) and other types of Android device 3345implementations SHOULD include support for Wi-Fi TDLS as described in the 3346Android SDK Documentation [<a href="http://developer.android.com/reference/android/net/wifi/WifiManager.html">Resources, 81</a>]. If a device implementation does include support for TDLS and TDLS is enabled 3347by the WiFiManager API, the device:</p> 3348 3349<ul> 3350 <li>SHOULD use TDLS only when it is possible AND beneficial.</li> 3351 <li>SHOULD have some heuristic and NOT use TDLS when its performance might be worse 3352than going through the Wi-Fi access point.</li> 3353</ul> 3354 3355<h3 id="7_4_3_bluetooth">7.4.3. Bluetooth</h3> 3356 3357<div class="note"> 3358<p>Android Watch and Automotive implementations MUST support Bluetooth. Android 3359Television implementations MUST support Bluetooth and Bluetooth LE.</p> 3360</div> 3361 3362 3363<p>Android includes support for Bluetooth and Bluetooth Low Energy [<a href="http://developer.android.com/reference/android/bluetooth/package-summary.html">Resources, 82</a>]. Device implementations that include support for Bluetooth and Bluetooth Low 3364Energy MUST declare the relevant platform features (android.hardware.bluetooth 3365and android.hardware.bluetooth_le respectively) and implement the platform 3366APIs. Device implementations SHOULD implement relevant Bluetooth profiles such 3367as A2DP, AVCP, OBEX, etc. as appropriate for the device. Android Television 3368device implementations MUST support Bluetooth and Bluetooth LE. </p> 3369 3370<p>Device implementations including support for Bluetooth Low Energy:</p> 3371 3372<ul> 3373 <li>MUST declare the hardware feature android.hardware.bluetooth_le.</li> 3374 <li>MUST enable the GATT (generic attribute profile) based Bluetooth APIs as 3375described in the SDK documentation and [<a href="http://developer.android.com/reference/android/bluetooth/package-summary.html">Resources, 82</a>].</li> 3376 <li>SHOULD support offloading of the filtering logic to the bluetooth chipset when 3377implementing the ScanFilter API [<a href="https://developer.android.com/reference/android/bluetooth/le/ScanFilter.html">Resources, 83</a>], and MUST report the correct value of where the filtering logic is implemented whenever queried via the 3378android.bluetooth.BluetoothAdapter.isOffloadedFilteringSupported() method.</li> 3379 <li>SHOULD support offloading of the batched scanning to the bluetooth chipset, but 3380if not supported, MUST report ‘false’ whenever queried via the 3381android.bluetooth.BluetoothAdapater.isOffloadedScanBatchingSupported() method.</li> 3382 <li>SHOULD support multi advertisement with at least 4 slots, but if not supported, 3383MUST report ‘false’ whenever queried via the 3384android.bluetooth.BluetoothAdapter.isMultipleAdvertisementSupported() method.</li> 3385</ul> 3386 3387<h3 id="7_4_4_near-field_communications">7.4.4. Near-Field Communications</h3> 3388 3389 3390<p>Device implementations SHOULD include a transceiver and related hardware for 3391Near-Field Communications (NFC). If a device implementation does include NFC 3392hardware and plans to make it available to third-party apps, then it:</p> 3393 3394<ul> 3395 <li>MUST report the android.hardware.nfc feature from the 3396android.content.pm.PackageManager.hasSystemFeature() method [<a href="http://developer.android.com/reference/android/content/pm/PackageManager.html">Resources, 53</a>].</li> 3397 <li>MUST be capable of reading and writing NDEF messages via the following NFC 3398standards: 3399 <ul> 3400 <li>MUST be capable of acting as an NFC Forum reader/writer (as defined by the NFC 3401Forum technical specification NFCForum-TS-DigitalProtocol-1.0) via the 3402following NFC standards: 3403 <ul> 3404 <li>NfcA (ISO14443-3A)</li> 3405 <li>NfcB (ISO14443-3B)</li> 3406 <li>NfcF (JIS 6319-4)</li> 3407 <li>IsoDep (ISO 14443-4)</li> 3408 <li>NFC Forum Tag Types 1, 2, 3, 4 (defined by the NFC Forum)</li> 3409 </ul> 3410 <li>SHOULD be capable of reading and writing NDEF messages via the following NFC 3411standards. Note that while the NFC standards below are stated as SHOULD, the 3412Compatibility Definition for a future version is planned to change these to 3413MUST. These standards are optional in this version but will be required in 3414future versions. Existing and new devices that run this version of Android are <strong>very strongly encouraged</strong> to meet these requirements now so they will be able to upgrade to the future platform releases.</li> 3415 <ul> 3416 <li>NfcV (ISO 15693)</li> 3417 </ul></li> 3418 <li>MUST be capable of transmitting and receiving data via the following 3419peer-to-peer standards and protocols: 3420 <ul> 3421 <li>ISO 18092</li> 3422 <li>LLCP 1.0 (defined by the NFC Forum)</li> 3423 <li>SDP 1.0 (defined by the NFC Forum)</li> 3424 <li>NDEF Push Protocol [<a href="http://static.googleusercontent.com/media/source.android.com/en/us/compatibility/ndef-push-protocol.pdf">Resources, 84</a>]</li> 3425 <li>SNEP 1.0 (defined by the NFC Forum)</li> 3426 </ul></li> 3427 <li>MUST include support for Android Beam [<a href="http://developer.android.com/guide/topics/connectivity/nfc/nfc.html">Resources, 85</a>]: 3428 <ul> 3429 <li>MUST implement the SNEP default server. Valid NDEF messages received by the 3430default SNEP server MUST be dispatched to applications using the 3431android.nfc.ACTION_NDEF_DISCOVERED intent. Disabling Android Beam in settings 3432MUST NOT disable dispatch of incoming NDEF message.</li> 3433 <li>MUST honor the android.settings.NFCSHARING_SETTINGS intent to show NFC sharing 3434settings [<a href="http://developer.android.com/reference/android/provider/Settings.html#ACTION_NFCSHARING_SETTINGS">Resources, 86</a>].</li> 3435 <li>MUST implement the NPP server. Messages received by the NPP server MUST be 3436processed the same way as the SNEP default server.</li> 3437 <li>MUST implement a SNEP client and attempt to send outbound P2P NDEF to the 3438default SNEP server when Android Beam is enabled. If no default SNEP server is 3439found then the client MUST attempt to send to an NPP server.</li> 3440 <li>MUST allow foreground activities to set the outbound P2P NDEF message using 3441android.nfc.NfcAdapter.setNdefPushMessage, and 3442android.nfc.NfcAdapter.setNdefPushMessageCallback, and 3443android.nfc.NfcAdapter.enableForegroundNdefPush.</li> 3444 <li>SHOULD use a gesture or on-screen confirmation, such as 'Touch to Beam', before 3445sending outbound P2P NDEF messages.</li> 3446 <li>SHOULD enable Android Beam by default and MUST be able to send and receive 3447using Android Beam, even when another proprietary NFC P2p mode is turned on.</li> 3448 <li>MUST support NFC Connection handover to Bluetooth when the device supports 3449Bluetooth Object Push Profile. Device implementations MUST support connection 3450handover to Bluetooth when using android.nfc.NfcAdapter.setBeamPushUris, by 3451implementing the “Connection Handover version 1.2” [<a href="http://members.nfc-forum.org/specs/spec_list/#conn_handover">Resources, 87</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, 88</a>] specs from the NFC Forum. Such an implementation MUST implement the handover 3452LLCP service with service name “urn:nfc:sn:handover” for exchanging the 3453handover request/select records over NFC, and it MUST use the Bluetooth Object 3454Push Profile for the actual Bluetooth data transfer. For legacy reasons (to 3455remain compatible with Android 4.1 devices), the implementation SHOULD still 3456accept SNEP GET requests for exchanging the handover request/select records 3457over NFC. However an implementation itself SHOULD NOT send SNEP GET requests 3458for performing connection handover.</li> 3459 </ul></li> 3460 <li>MUST poll for all supported technologies while in NFC discovery mode.</li> 3461 <li>SHOULD be in NFC discovery mode while the device is awake with the screen 3462active and the lock-screen unlocked.</li> 3463</ul> 3464</ul> 3465 3466<p>(Note that publicly available links are not available for the JIS, ISO, and NFC 3467Forum specifications cited above.)</p> 3468 3469<p>Android includes support for NFC Host Card Emulation (HCE) mode. If a 3470device implementation does include an NFC controller chipset capable of HCE and 3471Application ID (AID) routing, then it:</p> 3472 3473<ul> 3474 <li>MUST report the android.hardware.nfc.hce feature constant.</li> 3475 <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, 10</a>].</li> 3476</ul> 3477 3478<p>Additionally, device implementations MAY include reader/writer support for the 3479following MIFARE technologies.</p> 3480 3481<ul> 3482 <li>MIFARE Classic</li> 3483 <li>MIFARE Ultralight</li> 3484 <li>NDEF on MIFARE Classic</li> 3485</ul> 3486 3487<p>Note that Android includes APIs for these MIFARE types. If a device 3488implementation supports MIFARE in the reader/writer role, it:</p> 3489 3490<ul> 3491 <li>MUST implement the corresponding Android APIs as documented by the Android SDK.</li> 3492 <li>MUST report the feature com.nxp.mifare from the 3493android.content.pm.PackageManager.hasSystemFeature() meth<a href="http://developer.android.com/reference/android/content/pm/PackageManager.html">od [Resources, 53]</a>. Note that this is not a standard Android feature and as such does not appear 3494as a constant on the PackageManager class.</li> 3495 <li>MUST NOT implement the corresponding Android APIs nor report the com.nxp.mifare 3496feature unless it also implements general NFC support as described in this 3497section.</li> 3498</ul> 3499 3500<p>If a device implementation does not include NFC hardware, it MUST NOT declare 3501the android.hardware.nfc feature from the 3502android.content.pm.PackageManager.hasSystemFeature() method [<a href="http://developer.android.com/reference/android/content/pm/PackageManager.html">Resources, 53]</a>, and MUST implement the Android NFC API as a no-op.</p> 3503 3504<p>As the classes android.nfc.NdefMessage and android.nfc.NdefRecord represent a 3505protocol-independent data representation format, device implementations MUST 3506implement these APIs even if they do not include support for NFC or declare the 3507android.hardware.nfc feature.</p> 3508 3509<h3 id="7_4_5_minimum_network_capability">7.4.5. Minimum Network Capability</h3> 3510 3511 3512<p>Device implementations MUST include support for one or more forms of data 3513networking. Specifically, device implementations MUST include support for at 3514least one data standard capable of 200Kbit/sec or greater. Examples of 3515technologies that satisfy this requirement include EDGE, HSPA, EV-DO, 802.11g, 3516Ethernet, Bluetooth PAN, etc.</p> 3517 3518<p>Device implementations where a physical networking standard (such as Ethernet) 3519is the primary data connection SHOULD also include support for at least one 3520common wireless data standard, such as 802.11 (Wi-Fi).</p> 3521 3522<p>Devices MAY implement more than one form of data connectivity.</p> 3523 3524<h3 id="7_4_6_sync_settings">7.4.6. Sync Settings</h3> 3525 3526 3527<p>Device implementations MUST have the master auto-sync setting on by default so 3528that the method getMasterSyncAutomatically() returns “true” [<a href="http://developer.android.com/reference/android/content/ContentResolver.html">Resources, 89</a>].</p> 3529 3530<h2 id="7_5_cameras">7.5. Cameras</h2> 3531 3532 3533<p>Device implementations SHOULD include a rear-facing camera and MAY include a 3534front-facing camera. A rear-facing camera is a camera located on the side of 3535the device opposite the display; that is, it images scenes on the far side of 3536the device, like a traditional camera. A front-facing camera is a camera 3537located on the same side of the device as the display; that is, a camera 3538typically used to image the user, such as for video conferencing and similar 3539applications.</p> 3540 3541<p>If a device implementation includes at least one camera, it SHOULD be possible 3542for an application to simultaneously allocate 3 bitmaps equal to the size of 3543the images produced by the largest-resolution camera sensor on the device.</p> 3544 3545<h3 id="7_5_1_rear-facing_camera">7.5.1. Rear-Facing Camera</h3> 3546 3547 3548<p>Device implementations SHOULD include a rear-facing camera. If a device 3549implementation includes at least one rear-facing camera, it:</p> 3550 3551<ul> 3552 <li>MUST report the feature flag android.hardware.camera and 3553android.hardware.camera.any.</li> 3554 <li>MUST have a resolution of at least 2 megapixels.</li> 3555 <li>SHOULD have either hardware auto-focus or software auto-focus implemented in 3556the camera driver (transparent to application software).</li> 3557 <li>MAY have fixed-focus or EDOF (extended depth of field) hardware.</li> 3558 <li>MAY include a flash. If the Camera includes a flash, the flash lamp MUST NOT be 3559lit while an android.hardware.Camera.PreviewCallback instance has been 3560registered on a Camera preview surface, unless the application has explicitly 3561enabled the flash by enabling the FLASH_MODE_AUTO or FLASH_MODE_ON attributes 3562of a Camera.Parameters object. Note that this constraint does not apply to the 3563device’s built-in system camera application, but only to third-party 3564applications using Camera.PreviewCallback.</li> 3565</ul> 3566 3567<h3 id="7_5_2_front-facing_camera">7.5.2. Front-Facing Camera</h3> 3568 3569 3570<p>Device implementations MAY include a front-facing camera. If a device 3571implementation includes at least one front-facing camera, it:</p> 3572 3573<ul> 3574 <li>MUST report the feature flag android.hardware.camera.any and 3575android.hardware.camera.front.</li> 3576 <li>MUST have a resolution of at least VGA (640x480 pixels).</li> 3577 <li>MUST NOT use a front-facing camera as the default for the Camera API. The 3578camera API in Android has specific support for front-facing cameras and device 3579implementations MUST NOT configure the API to to treat a front-facing camera as 3580the default rear-facing camera, even if it is the only camera on the device.</li> 3581 <li>MAY include features (such as auto-focus, flash, etc.) available to rear-facing 3582cameras as described in <a href="#7_5_1_rear-facing_camera">section 7.5.1</a>.</li> 3583 <li>MUST horizontally reflect (i.e. mirror) the stream displayed by an app in a 3584CameraPreview, as follows: 3585 <ul> 3586 <li>If the device implementation is capable of being rotated by user (such as 3587automatically via an accelerometer or manually via user input), the camera 3588preview MUST be mirrored horizontally relative to the device’s current 3589orientation.</li> 3590 <li>If the current application has explicitly requested that the Camera display be 3591rotated via a call to the android.hardware.Camera.setDisplayOrientation()[<a href="http://developer.android.com/reference/android/hardware/Camera.html#setDisplayOrientation(int)">Resources, 90</a>] method, the camera preview MUST be mirrored horizontally relative to the 3592orientation specified by the application.</li> 3593 <li>Otherwise, the preview MUST be mirrored along the device’s default horizontal 3594axis.</li> 3595 </ul></li> 3596 <li>MUST mirror the image displayed by the postview in the same manner as the 3597camera preview image stream. If the device implementation does not support 3598postview, this requirement obviously does not apply.</li> 3599 <li>MUST NOT mirror the final captured still image or video streams returned to 3600application callbacks or committed to media storage.</li> 3601</ul> 3602 3603<h3 id="7_5_3_external_camera">7.5.3. External Camera</h3> 3604 3605 3606<p>Device implementations with USB host mode MAY include support for an external 3607camera that connects to the USB port. If a device includes support for an 3608external camera, it:</p> 3609 3610<ul> 3611 <li>MUST declare the platform feature android.hardware.camera.external and 3612android.hardware camera.any.</li> 3613 <li>MUST support USB Video Class (UVC 1.0 or higher).</li> 3614 <li>MAY support multiple cameras.</li> 3615</ul> 3616 3617<p>Video compression (such as MJPEG) support is RECOMMENDED to enable transfer of 3618high-quality unencoded streams (i.e. raw or independently compressed picture 3619streams). Camera-based video encoding MAY be supported. If so, a simultaneous 3620unencoded/ MJPEG stream (QVGA or greater resolution) MUST be accessible to the 3621device implementation.</p> 3622 3623<h3 id="7_5_4_camera_api_behavior">7.5.4. Camera API Behavior</h3> 3624 3625 3626<p>Android includes two API packages to access the camera, the newer 3627android.hardware.camera2 API expose lower-level camera control to the app, 3628including efficient zero-copy burst/streaming flows and per-frame controls of 3629exposure, gain, white balance gains, color conversion, denoising, sharpening, 3630and more.</p> 3631 3632<p>The older API package, android.hardware.Camera, is marked as deprecated in 3633Android 5.0 but as it should still be available for apps to use Android device 3634implementations MUST ensure the continued support of the API as described in 3635this section and in the Android SDK.</p> 3636 3637<p>Device implementations MUST implement the following behaviors for the 3638camera-related APIs, for all available cameras:</p> 3639 3640<ul> 3641 <li>If an application has never called 3642android.hardware.Camera.Parameters.setPreviewFormat(int), then the device MUST 3643use android.hardware.PixelFormat.YCbCr_420_SP for preview data provided to 3644application callbacks.</li> 3645 <li>If an application registers an android.hardware.Camera.PreviewCallback instance 3646and the system calls the onPreviewFrame() method when the preview format is 3647YCbCr_420_SP, the data in the byte[] passed into onPreviewFrame() must further 3648be in the NV21 encoding format. That is, NV21 MUST be the default.</li> 3649 <li>For android.hardware.Camera, device implementations MUST support the YV12 3650format (as denoted by the android.graphics.ImageFormat.YV12 constant) for 3651camera previews for both front- and rear-facing cameras. (The hardware video 3652encoder and camera may use any native pixel format, but the device 3653implementation MUST support conversion to YV12.)</li> 3654 <li>For android.hardware.camera2, device implementations must support the 3655android.hardware.ImageFormat.YUV_420_888 and android.hardware.ImageFormat.JPEG 3656formats as outputs through the android.media.ImageReader API.</li> 3657</ul> 3658 3659<p>Device implementations MUST still implement the full Camera API included in the 3660Android SDK documentation [<a href="http://developer.android.com/reference/android/hardware/Camera.html">Resources, 91</a>], regardless of whether the device includes hardware autofocus or other 3661capabilities. For instance, cameras that lack autofocus MUST still call any 3662registered android.hardware.Camera.AutoFocusCallback instances (even though 3663this has no relevance to a non-autofocus camera.) Note that this does apply to 3664front-facing cameras; for instance, even though most front-facing cameras do 3665not support autofocus, the API callbacks must still be “faked” as described.</p> 3666 3667<p>Device implementations MUST recognize and honor each parameter name defined as 3668a constant on the android.hardware.Camera.Parameters class, if the underlying 3669hardware supports the feature. If the device hardware does not support a 3670feature, the API must behave as documented. Conversely, device implementations 3671MUST NOT honor or recognize string constants passed to the 3672android.hardware.Camera.setParameters() method other than those documented as 3673constants on the android.hardware.Camera.Parameters. That is, device 3674implementations MUST support all standard Camera parameters if the hardware 3675allows, and MUST NOT support custom Camera parameter types. For instance, 3676device implementations that support image capture using high dynamic range 3677(HDR) imaging techniques MUST support camera parameter Camera.SCENE_MODE_HDR [<a href="http://developer.android.com/reference/android/hardware/Camera.Parameters.html">Resources, 92</a>].</p> 3678 3679<p>Because not all device implementations can fully support all the features of 3680the android.hardware.camera2 API, device implementations MUST report the proper 3681level of support with the android.info.supportedHardwareLevel property as 3682described in the Android SDK [<a href="https://developer.android.com/reference/android/hardware/camera2/CameraCharacteristics.html#INFO_SUPPORTED_HARDWARE_LEVEL">Resources, 93]</a> and report the appropriate framework feature flags [<a href="http://source.android.com/devices/camera/versioning.html">Resources, 94]</a>. </p> 3683 3684<p>Device implementations MUST also declare its Individual camera capabilities of 3685android.hardware.camera2 via the android.request.availableCapabilities property 3686and declare the appropriate feature flags [<a href="http://source.android.com/devices/camera/versioning.html">Resources, 94]</a>; a device must define the feature flag if any of its attached camera devices supports the feature.</p> 3687 3688<p>Device implementations MUST broadcast the Camera.ACTION_NEW_PICTURE intent 3689whenever a new picture is taken by the camera and the entry of the picture has 3690been added to the media store.</p> 3691 3692<p>Device implementations MUST broadcast the Camera.ACTION_NEW_VIDEO intent 3693whenever a new video is recorded by the camera and the entry of the picture has 3694been added to the media store.</p> 3695 3696<h3 id="7_5_5_camera_orientation">7.5.5. Camera Orientation</h3> 3697 3698 3699<p>Both front- and rear-facing cameras, if present, MUST be oriented so that the 3700long dimension of the camera aligns with the screen’s long dimension. That is, 3701when the device is held in the landscape orientation, cameras MUST capture 3702images in the landscape orientation. This applies regardless of the device’s 3703natural orientation; that is, it applies to landscape-primary devices as well 3704as portrait-primary devices.</p> 3705 3706<h2 id="7_6_memory_and_storage">7.6. Memory and Storage</h2> 3707 3708 3709<h3 id="7_6_1_minimum_memory_and_storage">7.6.1. Minimum Memory and Storage</h3> 3710 3711<div class="note"> 3712<p>Android Television devices MUST have at least 5GB of non-volatile storage 3713available for application private data.</p> 3714</div> 3715 3716 3717<p>The memory available to the kernel and userspace on device implementations MUST 3718be at least equal or larger than the minimum values specified by the following 3719table. (See <a href="#7_1_1_screen_configuration">section 7.1.1</a> for screen size and density definitions.)</p> 3720<table> 3721 <tr> 3722 <th>Density and screen size</th> 3723 <th>32-bit device</th> 3724 <th>64-bit device</th> 3725 </tr> 3726 <tr> 3727 <td>Android Watch devices (due to smaller screens)</td> 3728 <td>416MB</td> 3729 <td>Not applicable</td> 3730 </tr> 3731 <tr> 3732 <td><ul> 3733 <li class="table_list">280dpi or lower on small/normal screens</li> 3734 <li class="table_list">mdpi or lower on large screens</li> 3735 <li class="table_list">ldpi or lower on extra large screens</li> 3736 </ul></td> 3737 <td>424MB</td> 3738 <td>704MB</td> 3739 </tr> 3740 <tr> 3741 <td><ul> 3742 <li class="table_list">xhdpi or higher on small/normal screens</li> 3743 <li class="table_list">hdpi or higher on large screens</li> 3744 <li class="table_list">mdpi or higher on extra large screens</li></ul></td> 3745 <td>512MB</td> 3746 <td>832MB</td> 3747 </tr> 3748 <tr> 3749 <td><ul> 3750 <li class="table_list">400dpi or higher on small/normal screens</li> 3751 <li class="table_list">xhdpi or higher on large screens</li> 3752 <li class="table_list">tvdpi or higher on extra large screens</li></ul></td> 3753 <td>896MB</td> 3754 <td>1280MB</td> 3755 </tr> 3756 <tr> 3757 <td><ul> 3758 <li class="table_list">560dpi or higher on small/normal screens</li> 3759 <li class="table_list">400dpi or higher on large screens</li> 3760 <li class="table_list">xhdpi or higher on extra large screens</li></ul></td> 3761 <td>1344MB</td> 3762 <td>1824MB</td> 3763 </tr> 3764</table> 3765 3766 3767<p>The minimum memory values MUST be in addition to any memory space already 3768dedicated to hardware components such as radio, video, and so on that is not 3769under the kernel’s control.</p> 3770 3771<p>Device implementations with less than 512MB of memory available to the kernel 3772and userspace, unless an Android Watch, MUST return the value "true" for 3773ActivityManager.isLowRamDevice().</p> 3774 3775<p>Android Television devices MUST have at least 5GB and other device 3776implementations MUST have at least 1.5GB of non-volatile storage available for 3777application private data. That is, the /data partition MUST be at least 5GB for 3778Android Television devices and at least 1.5GB for other device implementations. 3779Device implementations that run Android are <strong>very strongly encouraged</strong> to have at least 3GB of non-volatile storage for application private data so 3780they will be able to upgrade to the future platform releases.</p> 3781 3782<p>The Android APIs include a Download Manager that applications MAY use to 3783download data files [<a href="http://developer.android.com/reference/android/app/DownloadManager.html">Resources, 95</a>]. The device implementation of the Download Manager MUST be capable of 3784downloading individual files of at least 100MB in size to the default “cache" 3785location.</p> 3786 3787<h3 id="7_6_2_application_shared_storage">7.6.2. Application Shared Storage</h3> 3788 3789 3790<p>Device implementations MUST offer shared storage for applications also often 3791referred as “shared external storage”. </p> 3792 3793<p>Device implementations MUST be configured with shared storage mounted by 3794default, “out of the box”. If the shared storage is not mounted on the Linux 3795path /sdcard, then the device MUST include a Linux symbolic link from /sdcard 3796to the actual mount point.</p> 3797 3798<p>Device implementations MAY have hardware for user-accessible removable storage, 3799such as a Secure Digital (SD) card slot. If this slot is used to satisfy the 3800shared storage requirement, the device implementation:</p> 3801 3802<ul> 3803 <li>MUST implement a toast or pop-up user interface warning the user when there is 3804no SD card.</li> 3805 <li>MUST include a FAT-formatted SD card 1GB in size or larger OR show on the box 3806and other material available at time of purchase that the SD card has to be 3807separately purchased.</li> 3808 <li>MUST mount the SD card by default.</li> 3809</ul> 3810 3811<p>Alternatively, device implementations MAY allocate internal (non-removable) 3812storage as shared storage for apps as included in the upstream Android Open 3813Source Project; device implementations SHOULD use this configuration and 3814software implementation. If a device implementation uses internal 3815(non-removable) storage to satisfy the shared storage requirement, that storage 3816MUST be 1GB in size or larger and mounted on /sdcard (or /sdcard MUST be a 3817symbolic link to the physical location if it is mounted elsewhere).</p> 3818 3819<p>Device implementations MUST enforce as documented the 3820android.permission.WRITE_EXTERNAL_STORAGE permission on this shared storage. 3821Shared storage MUST otherwise be writable by any application that obtains that 3822permission.</p> 3823 3824<p>Device implementations that include multiple shared storage paths (such as both 3825an SD card slot and shared internal storage) MUST NOT allow Android 3826applications to write to the secondary external storage, except for their 3827package-specific directories on the secondary external storage, but SHOULD 3828expose content from both storage paths transparently through Android’s media 3829scanner service and android.provider.MediaStore.</p> 3830 3831<p>Regardless of the form of shared storage used, if the device implementation 3832has a USB port with USB peripheral mode support, it MUST provide some mechanism 3833to access the contents of shared storage from a host computer. Device 3834implementations MAY use USB mass storage, but SHOULD use Media Transfer Protocol 3835to satisfy this requirement. If the device implementation supports Media 3836Transfer Protocol, it:</p> 3837 3838<ul> 3839 <li>SHOULD be compatible with the reference Android MTP host, Android File Transfer 3840[<a href="http://www.android.com/filetransfer">Resources, 96</a>].</li> 3841 <li>SHOULD report a USB device class of 0x00.</li> 3842 <li>SHOULD report a USB interface name of 'MTP'.</li> 3843</ul> 3844 3845<h2 id="7_7_usb">7.7. USB</h2> 3846 3847 3848<p>Device implementations SHOULD support USB peripheral mode and SHOULD support 3849USB host mode.</p> 3850 3851<p>If a device implementation includes a USB port supporting peripheral mode:</p> 3852 3853<ul> 3854 <li>The port MUST be connectable to a USB host that has a standard type-A or type 3855-C USB port.</li> 3856 <li>The port SHOULD use micro-A, micro-AB or type-C USB form factor. Existing and 3857new Android devices are <strong>very strongly encouraged to meet these requirements</strong> so they will be able to upgrade to the future platform releases.</li> 3858 <li>The port SHOULD be centered in the middle of an edge. Device implementations 3859SHOULD either locate the port on the bottom of the device (according to natural 3860orientation) or enable software screen rotation for all apps (including home 3861screen), so that the display draws correctly when the device is oriented with 3862the port at bottom. Existing and new Android devices are <strong>very strongly encouraged to meet these requirements</strong> so they will be able to upgrade to future platform releases.</li> 3863 <li>It MUST allow a USB host connected with the Android device to access the 3864contents of the shared storage volume using either USB mass storage or Media 3865Transfer Protocol.</li> 3866 <li>It SHOULD implement the Android Open Accessory (AOA) API and specification as 3867documented in the Android SDK documentation, and if it is an Android Handheld 3868device it MUST implement the AOA API. Device implementations implementing the 3869AOA specification: 3870 <ul> 3871 <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, 97</a>].</li> 3872 <li>MUST implement the USB audio class as documented in the Android SDK 3873documentation [<a href="http://developer.android.com/reference/android/hardware/usb/UsbConstants.html#USB_CLASS_AUDIO">Resources, 98</a>].</li> 3874 </ul></li> 3875 <li>It SHOULD implement support to draw 1.5 A current during HS chirp and traffic 3876as specified in the USB battery charging specification [<a href="http://www.usb.org/developers/docs/devclass_docs/USB_Battery_Charging_1.2.pdf">Resources, 99</a>]. Existing and new Android devices are <strong>very strongly encouraged to meet these requirements</strong> so they will be able to upgrade to the future platform releases.</li> 3877 <li>The value of iSerialNumber in USB standard device descriptor MUST be equal to 3878the value of android.os.Build.SERIAL.</li> 3879</ul> 3880 3881<p>If a device implementation includes a USB port supporting host mode, it:</p> 3882 3883<ul> 3884 <li>SHOULD use a type-C USB port, if the device implementation supports USB 3.1.</li> 3885 <li>MAY use a non-standard port form factor, but if so MUST ship with a cable or 3886cables adapting the port to a standard type-A or type-C USB port.</li> 3887 <li>MAY use a micro-AB USB port, but if so SHOULD ship with a cable or cables 3888adapting the port to a standard type-A or type-C USB port.</li> 3889 <li>is <strong>very strongly RECOMMENDED</strong> to implement the USB audio class as documented in the Android SDK 3890documentation [<a href="http://developer.android.com/reference/android/hardware/usb/UsbConstants.html#USB_CLASS_AUDIO">Resources, 98</a>].</li> 3891 <li>MUST implement the Android USB host API as documented in the Android SDK, and 3892MUST declare support for the hardware feature android.hardware.usb.host [<a href="http://developer.android.com/guide/topics/connectivity/usb/host.html">Resources, 100</a>].</li> 3893 <li>SHOULD support the Charging Downstream Port output current range of 1.5 A ~ 5 A 3894as specified in the USB Battery Charging Specifications [<a href="http://www.usb.org/developers/docs/devclass_docs/USB_Battery_Charging_1.2.pdf">Resources, 99</a>].</li> 3895</ul> 3896 3897<h2 id="7_8_audio">7.8. Audio</h2> 3898 3899 3900<h3 id="7_8_1_microphone">7.8.1. Microphone</h3> 3901 3902<div class="note"> 3903<p>Android Handheld, Watch, and Automotive implementations MUST include a 3904microphone.</p> 3905</div> 3906 3907 3908<p>Device implementations MAY omit a microphone. However, if a device 3909implementation omits a microphone, it MUST NOT report the 3910android.hardware.microphone feature constant, and MUST implement the audio 3911recording API at least as no-ops, per <a href="#7_hardware_compatibility">section 7</a>. Conversely, device implementations that do possess a microphone:</p> 3912 3913<ul> 3914 <li>MUST report the android.hardware.microphone feature constant 3915 <li>MUST meet the audio recording requirements in <a href="#5_4_audio_recording">section 5.4</a> 3916 <li>MUST meet the audio latency requirements in <a href="#5_6_audio_latency">section 5.6</a> 3917</ul> 3918 3919<h3 id="7_8_2_audio_output">7.8.2. Audio Output</h3> 3920 3921<div class="note"> 3922<p>Android Watch devices MAY include an audio output.</p> 3923</div> 3924 3925<p>Device implementations including a speaker or with an audio/multimedia output 3926port for an audio output peripheral as a headset or an external speaker:</p> 3927 3928<ul> 3929 <li>MUST report the android.hardware.audio.output feature constant.</li> 3930 <li>MUST meet the audio playback requirements in <a href="#5_5_audio_playback">section 5.5</a>.</li> 3931 <li>MUST meet the audio latency requirements in <a href="#5_6_audio_latency">section 5.6</a>.</li> 3932</ul> 3933 3934<p>Conversely, if a device implementation does not include a speaker or audio 3935output port, it MUST NOT report the android.hardware.audio output feature, and 3936MUST implement the Audio Output related APIs as no-ops at least. </p> 3937 3938<p>Android Watch device implementation MAY but SHOULD NOT have audio output, but 3939other types of Android device implementations MUST have an audio output and 3940declare android.hardware.audio.output.</p> 3941 3942<h4 id="7_8_2_1_analog_audio_ports">7.8.2.1. Analog Audio Ports</h4> 3943 3944 3945<p>In order to be compatible with the headsets and other audio accessories using 3946the 3.5mm audio plug across the Android ecosystem [<a href="http://source.android.com/accessories/headset-spec.html">Resources, 101</a>], if a device implementation includes one or more analog audio ports, at least 3947one of the audio port(s) SHOULD be a 4 conductor 3.5mm audio jack. If a device 3948implementation has a 4 conductor 3.5mm audio jack, it:</p> 3949 3950<ul> 3951 <li>MUST support audio playback to stereo headphones and stereo headsets with a 3952microphone, and SHOULD support audio recording from stereo headsets with a 3953microphone.</li> 3954 <li>MUST support TRRS audio plugs with the CTIA pin-out order, and SHOULD support 3955audio plugs with the OMTP pin-out order.</li> 3956 <li>MUST support the detection of microphone on the plugged in audio accessory, if 3957the device implementation supports a microphone, and broadcast the 3958android.intent.action.HEADSET_PLUG with the extra value microphone set as 1.</li> 3959 <li>SHOULD support the detection and mapping to the keycodes for the following 3 3960ranges of equivalent impedance between the microphone and ground conductors on 3961the audio plug: 3962 <ul> 3963 <li><strong>70 ohm or less</strong>: KEYCODE_HEADSETHOOK</li> 3964 <li><strong>210-290 Ohm</strong>:<strong> </strong>KEYCODE_VOLUME_UP</li> 3965 <li><strong>360-680 Ohm</strong>: KEYCODE_VOLUME_DOWN</li> 3966 </ul></li> 3967 <li>SHOULD support the detection and mapping to the keycode for the following range 3968of equivalent impedance between the microphone and ground conductors on the 3969audio plug: 3970 <ul> 3971 <li><strong>110-180 Ohm: </strong>KEYCODE_VOICE_ASSIST</li> 3972 </ul></li> 3973 <li>MUST trigger ACTION_HEADSET_PLUG upon a plug insert, but only after all 3974contacts on plug are touching their relevant segments on the jack.</li> 3975 <li>MUST be capable of driving at least 150mV +/- 10% of output voltage on a 32 Ohm 3976speaker impedance.</li> 3977 <li>MUST have a microphone bias voltage between 1.8V ~ 2.9V.</li> 3978</ul> 3979 3980<h1 id="8_performance_compatibility">8. Performance Compatibility</h1> 3981 3982 3983<p>Some minimum performance criterias are critical to the user experience and 3984impacts the baseline assumptions developers would have when developing an app. 3985Android Watch devices SHOULD and other type of device implementations MUST meet 3986the following criteria:</p> 3987 3988<h2 id="8_1_user_experience_consistency">8.1. User Experience Consistency</h2> 3989 3990 3991<p>Device implementations MUST provide a smooth user interface by ensuring a 3992consistent frame rate and response times for applications and games. Device 3993implementations MUST meet the following requirements: </p> 3994 3995<ul> 3996 <li><strong>Consistent frame latency</strong>. Inconsistent frame latency or a delay to render frames MUST NOT happen more 3997often than 5 frames in a second, and SHOULD be below 1 frames in a second.</li> 3998 <li><strong>User interface latency</strong>. Device implementations MUST ensure low latency user experience by scrolling a 3999list of 10K list entries as defined by the Android Compatibility Test Suite 4000(CTS) in less than 36 secs.</li> 4001 <li><strong>Task switching</strong>. When multiple applications have been launched, re-launching an already-running 4002application after it has been launched MUST take less than 1 second.</li> 4003</ul> 4004 4005<h2 id="8_2_file_i_o_access_performance">8.2. File I/O Access Performance</h2> 4006 4007 4008<p>Device implementations MUST ensure internal storage file access performance consistency for read 4009and write operations. </p> 4010 4011<ul> 4012 <li><strong>Sequential write</strong>. Device implementations MUST ensure a sequential write performance of at least 5MB/s 4013for a 256MB file using 10MB write buffer.</li> 4014 <li><strong>Random write</strong>. Device implementations MUST ensure a random write performance of at least 0.5MB/s for a 4015256MB file using 4KB write buffer.</li> 4016 <li><strong>Sequential read</strong>. Device implementations MUST ensure a sequential read performance of at least 15MB/s for 4017a 256MB file using 10MB write buffer.</li> 4018 <li><strong>Random read</strong>. Device implementations MUST ensure a random read performance of at least 3.5MB/s for a 4019256MB file using 4KB write buffer.</li> 4020</ul> 4021 4022<h1 id="9_security_model_compatibility">9. Security Model Compatibility</h1> 4023 4024 4025<p>Device implementations MUST implement a security model consistent with the 4026Android platform security model as defined in Security and Permissions 4027reference document in the APIs [<a href="http://developer.android.com/guide/topics/security/permissions.html">Resources, 102</a>] in the Android developer documentation. Device implementations MUST support 4028installation of self-signed applications without requiring any additional 4029permissions/certificates from any third parties/authorities. Specifically, 4030compatible devices MUST support the security mechanisms described in the follow 4031subsections.</p> 4032 4033<h2 id="9_1_permissions">9.1. Permissions</h2> 4034 4035 4036<p>Device implementations MUST support the Android permissions model as defined in 4037the Android developer documentation [<a href="http://developer.android.com/guide/topics/security/permissions.html">Resources, 102</a>]. Specifically, implementations MUST enforce each permission defined as 4038described in the SDK documentation; no permissions may be omitted, altered, or 4039ignored. Implementations MAY add additional permissions, provided the new 4040permission ID strings are not in the android.* namespace.</p> 4041 4042<h2 id="9_2_uid_and_process_isolation">9.2. UID and Process Isolation</h2> 4043 4044 4045<p>Device implementations MUST support the Android application sandbox model, in 4046which each application runs as a unique Unixstyle UID and in a separate 4047process. Device implementations MUST support running multiple applications as 4048the same Linux user ID, provided that the applications are properly signed and 4049constructed, as defined in the Security and Permissions reference [<a href="http://developer.android.com/guide/topics/security/permissions.html">Resources, 102</a>].</p> 4050 4051<h2 id="9_3_filesystem_permissions">9.3. Filesystem Permissions</h2> 4052 4053 4054<p>Device implementations MUST support the Android file access permissions model 4055as defined in the Security and Permissions reference [<a href="http://developer.android.com/guide/topics/security/permissions.html">Resources, 102</a>].</p> 4056 4057<h2 id="9_4_alternate_execution_environments">9.4. Alternate Execution Environments</h2> 4058 4059 4060<p>Device implementations MAY include runtime environments that execute 4061applications using some other software or technology than the Dalvik Executable 4062Format or native code. However, such alternate execution environments MUST NOT 4063compromise the Android security model or the security of installed Android 4064applications, as described in this section.</p> 4065 4066<p>Alternate runtimes MUST themselves be Android applications, and abide by the 4067standard Android security model, as described elsewhere in <a href="#9_security_model_compatibility">section 9</a>.</p> 4068 4069<p>Alternate runtimes MUST NOT be granted access to resources protected by 4070permissions not requested in the runtime’s AndroidManifest.xml file via the 4071<uses-permission> mechanism.</p> 4072 4073<p>Alternate runtimes MUST NOT permit applications to make use of features 4074protected by Android permissions restricted to system applications.</p> 4075 4076<p>Alternate runtimes MUST abide by the Android sandbox model. Specifically, 4077alternate runtimes:</p> 4078 4079<ul> 4080 <li>SHOULD install apps via the PackageManager into separate Android sandboxes ( 4081Linux user IDs, etc.).</li> 4082 <li>MAY provide a single Android sandbox shared by all applications using the 4083alternate runtime.</li> 4084 <li>and installed applications using an alternate runtime, MUST NOT reuse the 4085sandbox of any other app installed on the device, except through the standard 4086Android mechanisms of shared user ID and signing certificate.</li> 4087 <li>MUST NOT launch with, grant, or be granted access to the sandboxes 4088corresponding to other Android applications.</li> 4089 <li>MUST NOT be launched with, be granted, or grant to other applications any 4090privileges of the superuser (root), or of any other user ID.</li> 4091</ul> 4092 4093<p>The .apk files of alternate runtimes MAY be included in the system image of a 4094device implementation, but MUST be signed with a key distinct from the key used 4095to sign other applications included with the device implementation.</p> 4096 4097<p>When installing applications, alternate runtimes MUST obtain user consent for 4098the Android permissions used by the application. If an application needs to 4099make use of a device resource for which there is a corresponding Android 4100permission (such as Camera, GPS, etc.), the alternate runtime MUST inform the 4101user that the application will be able to access that resource. If the runtime 4102environment does not record application capabilities in this manner, the 4103runtime environment MUST list all permissions held by the runtime itself when 4104installing any application using that runtime.</p> 4105 4106<h2 id="9_5_multi-user_support">9.5. Multi-User Support</h2> 4107 4108<div class="note"> 4109<p>This feature is optional for all device types.</p> 4110</div> 4111 4112 4113<p>Android includes support for multiple users and provides support for full user 4114isolation [<a href="http://developer.android.com/reference/android/os/UserManager.html">Resources, 103]</a>. Device implementations MAY enable multiple users, but when enabled MUST meet 4115the following requirements related to multi-user support [<a href="http://source.android.com/devices/storage/">Resources, 104</a>]:</p> 4116 4117<ul> 4118 <li>Device implementations that do not declare the android.hardware.telephony 4119feature flag MUST support restricted profiles, a feature that allows device 4120owners to manage additional users and their capabilities on the device. With 4121restricted profiles, device owners can quickly set up separate environments for 4122additional users to work in, with the ability to manage finer-grained 4123restrictions in the apps that are available in those environments.</li> 4124 <li>Conversely device implementations that declare the android.hardware.telephony 4125feature flag MUST NOT support restricted profiles but MUST align with the AOSP 4126implementation of controls to enable /disable other users from accessing the 4127voice calls and SMS.</li> 4128 <li>Device implementations MUST, for each user, implement a security model 4129consistent with the Android platform security model as defined in Security and 4130Permissions reference document in the APIs [<a href="http://developer.android.com/guide/topics/security/permissions.html">Resources, 102</a>].</li> 4131 <li>Device implementations MAY support creating users and managed profiles via the 4132android.app.admin.DevicePolicyManager APIs, and if supported, MUST declare the 4133platform feature flag android.software.managed_users. 4134 <li>Device implementations that declare the feature flag 4135android.software.managed_users MUST use the upstream AOSP icon badge to 4136represent the managed applications and other badge UI elements like Recents & 4137Notifications.</li> 4138 <li>Each user instance on an Android device MUST have separate and isolated 4139external storage directories. Device implementations MAY store multiple users' 4140data on the same volume or filesystem. However, the device implementation MUST 4141ensure that applications owned by and running on behalf a given user cannot 4142list, read, or write to data owned by any other user. Note that removable 4143media, such as SD card slots, can allow one user to access another’s data by 4144means of a host PC. For this reason, device implementations that use removable 4145media for the external storage APIs MUST encrypt the contents of the SD card if 4146multiuser is enabled using a key stored only on non-removable media accessible 4147only to the system. As this will make the media unreadable by a host PC, device 4148implementations will be required to switch to MTP or a similar system to 4149provide host PCs with access to the current user’s data. Accordingly, device 4150implementations MAY but SHOULD NOT enable multi-user if they use removable 4151media [<a href="http://developer.android.com/reference/android/os/Environment.html">Resources, 105</a>] for primary external storage.</li> 4152</ul> 4153 4154<h2 id="9_6_premium_sms_warning">9.6. Premium SMS Warning</h2> 4155 4156 4157<p>Android includes support for warning users of any outgoing premium SMS message 4158[<a href="http://en.wikipedia.org/wiki/Short_code">Resources, 106</a>] . Premium SMS messages are text messages sent to a service registered with a 4159carrier that may incur a charge to the user. Device implementations that 4160declare support for android.hardware.telephony MUST warn users before sending a 4161SMS message to numbers identified by regular expressions defined in 4162/data/misc/sms/codes.xml file in the device. The upstream Android Open Source 4163Project provides an implementation that satisfies this requirement.</p> 4164 4165<h2 id="9_7_kernel_security_features">9.7. Kernel Security Features</h2> 4166 4167 4168<p>The Android Sandbox includes features that can use the Security-Enhanced Linux 4169(SELinux) mandatory access control (MAC) system and other security features in 4170the Linux kernel. SELinux or any other security features, if implemented below 4171the Android framework:</p> 4172 4173<ul> 4174 <li>MUST maintain compatibility with existing applications.</li> 4175 <li>MUST NOT have a visible user interface when a security violation is detected 4176and successfully blocked, but MAY have a visible user interface when an 4177unblocked security violation occurs resulting in a successful exploit.</li> 4178 <li>SHOULD NOT be user or developer configurable.</li> 4179</ul> 4180 4181<p>If any API for configuration of policy is exposed to an application that can 4182affect another application (such as a Device Administration API), the API MUST 4183NOT allow configurations that break compatibility.</p> 4184 4185<p>Devices MUST implement SELinux or an equivalent mandatory access control system 4186if using a kernel other than Linux and meet the following requirements, which 4187are satisfied by the reference implementation in the upstream Android Open 4188Source Project.</p> 4189 4190<p>Device implementations:</p> 4191 4192<ul> 4193 <li>MUST support a SELinux policy that allows the SELinux mode to be set on a 4194per-domain basis, and MUST configure all domains in enforcing mode. No 4195permissive mode domains are allowed, including domains specific to a 4196device/vendor.</li> 4197 <li>SHOULD load policy from /sepolicy file on the device.</li> 4198 <li>MUST NOT modify, omit, or replace the neverallow rules present within the 4199sepolicy file provided in the upstream Android Open Source Project (AOSP) and 4200the policy MUST compile with all neverallow present, for both AOSP SELinux 4201domains as well as device/vendor specific domains.</li> 4202 <li>MUST support dynamic updates of the SELinux policy file without requiring a 4203system image update.</li> 4204</ul> 4205 4206<p>Device implementations SHOULD retain the default SELinux policy provided in the 4207upstream Android Open Source Project, until they have first audited their 4208additions to the SELinux policy. Device implementations MUST be compatible with 4209the upstream Android Open Source Project.</p> 4210 4211<h2 id="9_8_privacy">9.8. Privacy</h2> 4212 4213<p>If the device implements functionality in the system that captures the contents 4214displayed on the screen and/or records the audio stream played on the device, 4215it MUST continuously notify the user whenever this functionality is enabled and 4216actively capturing/recording.</p> 4217 4218<p>If a device implementation has a mechanism that routes network data traffic 4219through a proxy server or VPN gateway by default (for example, preloading a VPN 4220service with android.permission.CONTROL_VPN granted), the device implementation 4221MUST ask for the user's consent before enabling that mechanism.</p> 4222 4223<h2 id="9_9_full-disk_encryption">9.9. Full-Disk Encryption</h2> 4224 4225<div class="note"> 4226<p>Optional for Android device implementations without a lock screen.</p> 4227</div> 4228 4229 4230<p>If the device implementation supports a lock screen with PIN (numeric) or 4231PASSWORD (alphanumeric), the device MUST support full-disk encryption of the 4232application private data (/data partition), as well 4233as the SD card partition if it is a permanent, non-removable part of the device 4234[<a href="http://source.android.com/devices/tech/security/encryption/index.html">Resources, 107</a>]. For devices supporting full-disk encryption, the full-disk encryption SHOULD 4235be enabled all the time after the user has completed the out-of-box experience. 4236While this requirement is stated as SHOULD for this version of the Android 4237platform, it is <strong>very strongly RECOMMENDED</strong> as we expect this to change to MUST in the future versions of Android. 4238Encryption MUST use AES with a key of 128-bits (or greater) and a mode designed 4239for storage (for example, AES-XTS, AES-CBC-ESSIV). The encryption key MUST NOT 4240be written to storage at any time without being encrypted. Other than when in 4241active use, the encryption key SHOULD be AES encrypted with the lockscreen 4242passcode stretched using a slow stretching algorithm (e.g. PBKDF2 or scrypt). 4243If the user has not specified a lockscreen passcode or has disabled use of the 4244passcode for encryption, the system SHOULD use a default passcode to wrap the 4245encryption key. If the device provides a hardware-backed keystore, the password 4246stretching algorithm MUST be cryptographically bound to that keystore. The 4247encryption key MUST NOT be sent off the device (even when wrapped with the user 4248passcode and/or hardware bound key). The upstream Android Open Source project 4249provides a preferred implementation of this feature based on the linux kernel 4250feature dm-crypt.</p> 4251 4252<h2 id="9_10_verified_boot">9.10. Verified Boot</h2> 4253 4254<p> 4255Verified boot is a feature that guarantees the integrity of the device software. 4256If a device implementation supports the feature, it MUST: 4257<ul> 4258<li>Declare the platform feature flag android.software.verified_boot</li> 4259<li>Perform verification on every boot sequence</li> 4260<li>Start verification from a hardware key that is the root of trust, and go 4261all the way up to the system partition</li> 4262<li>Implement each stage of verification to check the integrity and authenticity 4263of all the bytes in the next stage before executing the code in the next stage</li> 4264<li>Use verification algorithms as strong as current recommendations 4265from NIST for hashing algorithms (SHA-256) and public key sizes (RSA-2048)</li> 4266</ul> 4267</p> 4268 4269<p>Device implementations SHOULD support verified boot for device integrity. 4270While this requirement is SHOULD for this version of the Android platform, 4271it is <strong>strongly RECOMMENDED</strong> as we expect this to change to MUST 4272in future versions of Android. The upstream Android Open Source Project provides 4273a preferred implementation of this feature based on the linux kernel feature dm-verity. 4274</p> 4275 4276<h1 id="10_software_compatibility_testing">10. Software Compatibility Testing</h1> 4277 4278 4279<p>Device implementations MUST pass all tests described in this section.</p> 4280 4281<p>However, note that no software test package is fully comprehensive. For this 4282reason, device implementers are <strong>very strongly encouraged</strong> to make the minimum number of changes as possible to the reference and 4283preferred implementation of Android available from the Android Open Source 4284Project. This will minimize the risk of introducing bugs that create 4285incompatibilities requiring rework and potential device updates.</p> 4286 4287<h2 id="10_1_compatibility_test_suite">10.1. Compatibility Test Suite</h2> 4288 4289 4290<p>Device implementations MUST pass the Android Compatibility Test Suite (CTS) [<a href="http://source.android.com/compatibility/index.html">Resources, 108</a>] available from the Android Open Source Project, using the final shipping 4291software on the device. Additionally, device implementers SHOULD use the 4292reference implementation in the Android Open Source tree as much as possible, 4293and MUST ensure compatibility in cases of ambiguity in CTS and for any 4294reimplementations of parts of the reference source code.</p> 4295 4296<p>The CTS is designed to be run on an actual device. Like any software, the CTS 4297may itself contain bugs. The CTS will be versioned independently of this 4298Compatibility Definition, and multiple revisions of the CTS may be released for 4299Android 5.1. Device implementations MUST pass the latest CTS version available 4300at the time the device software is completed.</p> 4301 4302<h2 id="10_2_cts_verifier">10.2. CTS Verifier</h2> 4303 4304 4305<p>Device implementations MUST correctly execute all applicable cases in the CTS 4306Verifier. The CTS Verifier is included with the Compatibility Test Suite, and 4307is intended to be run by a human operator to test functionality that cannot be 4308tested by an automated system, such as correct functioning of a camera and 4309sensors.</p> 4310 4311<p>The CTS Verifier has tests for many kinds of hardware, including some hardware 4312that is optional. Device implementations MUST pass all tests for hardware that 4313they possess; for instance, if a device possesses an accelerometer, it MUST 4314correctly execute the Accelerometer test case in the CTS Verifier. Test cases 4315for features noted as optional by this Compatibility Definition Document MAY be 4316skipped or omitted.</p> 4317 4318<p>Every device and every build MUST correctly run the CTS Verifier, as noted 4319above. However, since many builds are very similar, device implementers are not 4320expected to explicitly run the CTS Verifier on builds that differ only in 4321trivial ways. Specifically, device implementations that differ from an 4322implementation that has passed the CTS Verifier only by the set of included 4323locales, branding, etc. MAY omit the CTS Verifier test.</p> 4324 4325<h1 id="11_updatable_software">11. Updatable Software</h1> 4326 4327 4328<p>Device implementations MUST include a mechanism to replace the entirety of the 4329system software. The mechanism need not perform “live” upgrades—that is, a 4330device restart MAY be required.</p> 4331 4332<p>Any method can be used, provided that it can replace the entirety of the 4333software preinstalled on the device. For instance, any of the following 4334approaches will satisfy this requirement:</p> 4335 4336<ul> 4337 <li>“Over-the-air (OTA)” downloads with offline update via reboot</li> 4338 <li>“Tethered” updates over USB from a host PC</li> 4339 <li>“Offline” updates via a reboot and update from a file on removable storage</li> 4340</ul> 4341 4342<p>However, if the device implementation includes support for an unmetered data 4343connection such as 802.11 or Bluetooth PAN (Personal Area Network) profile:</p> 4344 4345<ul> 4346<li>Android Automotive implementations SHOULD support OTA downloads with offline 4347update via reboot.</li> 4348<li>All other device implementations MUST support OTA downloads with offline 4349update via reboot.</li> 4350</ul> 4351 4352<p>The update mechanism used MUST support updates without wiping user data. That 4353is, the update mechanism MUST preserve application private data and application 4354shared data. Note that the upstream Android software includes an update 4355mechanism that satisfies this requirement.</p> 4356 4357<p>For device implementations that are launching with Android 5.1 and later, the 4358update mechanism SHOULD support verifying that the system image is binary 4359identical to expected result following an OTA. The block-based OTA 4360implementation in the upstream Android Open Source Project, added since Android 43615.1, satisfies this requirement.</p> 4362 4363<p>If an error is found in a device implementation after it has been released but 4364within its reasonable product lifetime that is determined in consultation with 4365the Android Compatibility Team to affect the compatibility of third-party 4366applications, the device implementer MUST correct the error via a software 4367update available that can be applied per the mechanism just described.</p> 4368 4369<h1 id="12_document_changelog">12. Document Changelog</h1> 4370 4371 4372<p>The following table contains a summary of the changes to the Compatibility 4373Definition in this release. </p> 4374<table> 4375 <tr> 4376 <th>Section</th> 4377 <th>Summary of change</th> 4378 </tr> 4379 <tr> 4380 <td>2. Device Types</td> 4381 <td>Added definition for Android automotive implementation.</td> 4382 </tr> 4383 <tr> 4384 <td>2.1 Device Configurations</td> 4385 <td>Added column for Android automotive implementation.</td> 4386 </tr> 4387 <tr> 4388 <td>3.3.2. 32-bit ARM Native Code Compatibility</td> 4389 <td>New section added.</td> 4390 </tr> 4391 <tr> 4392 <td>3.4.1. WebView Compatibility</td> 4393 <td>Updated webview user agent string requirement to accomodate upstream 4394 implementation change.</td> 4395 </tr> 4396 <tr> 4397 <td>3.4.2. Browser compatibility</td> 4398 <td>Added Android automotive implementations as another case that MAY omit a 4399 browser application.</td> 4400 </tr> 4401 <tr> 4402 <td>3.7. Runtime Compatibility</td> 4403 <td>Updated required runtime heap size for smaller screens and added requirement 4404 for the new dpi bucket (280dpi).</td> 4405 </tr> 4406 <tr> 4407 <td>3.8.3. Notifications</td> 4408 <td>Clarified notification requirement for Android Watch, Television and 4409 Automotive implementations.</td> 4410 </tr> 4411 <tr> 4412 <td>3.8.10. Lock Screen Media Control<</td> 4413 <td>Clarified requirement for Android Watch and Automotive implementations.</td> 4414 </tr> 4415 <tr> 4416 <td>3.8.13. Unicode and font</td> 4417 <td>Relaxed Emoji character input method requirement.</td> 4418 </tr> 4419 <tr> 4420 <td>3.9. Device Administration</td> 4421 <td>Clarified condition when the full range of device administration policies 4422 has to be supported.</td> 4423 </tr> 4424 <tr> 4425 <td>3.10. Accessibility</td> 4426 <td>Added Android automotive requirements.</td> 4427 </tr> 4428 <tr> 4429 <td>3.11. Text-To-Speech</td> 4430 <td>Added Android automotive requirements.</td> 4431 </tr> 4432 <tr> 4433 <td>5.1. Media Codecs</td> 4434 <td>Mandated decoding support for codecs reported by CamcorderProfile.</td> 4435 </tr> 4436 <tr> 4437 <td>5.1.3 Video Codecs</td> 4438 <td>Added Android automotive requirements.</td> 4439 </tr> 4440 <tr> 4441 <td>7.1.1.3. Screen Density</td> 4442 <td>Added a new screen dpi (280dpi).</td> 4443 </tr> 4444 <tr> 4445 <td>7.1.5. Legacy Application Compatibility Mode</td> 4446 <td>Added Android automotive requirements.</td> 4447 </tr> 4448 <tr> 4449 <td>7.2 Input Devices</td> 4450 <td>Added general introduction statement.</td> 4451 </tr> 4452 <tr> 4453 <td>7.2.1. Keyboard</td> 4454 <td>Added Android Automotive requirements.</td> 4455 </tr> 4456 <tr> 4457 <td>7.2.3. Navigation Keys</td> 4458 <td>Added Android Automotive requirements.</td> 4459 </tr> 4460 <tr> 4461 <td>7.3.1. Accelerometer</td> 4462 <td>Relaxed requirement for reporting frequency on Android Watch.</td> 4463 </tr> 4464 <tr> 4465 <td>7.3.4. Gyroscope</td> 4466 <td>Relaxed requirement for reporting frequency on Android Watch.</td> 4467 </tr> 4468 <tr> 4469 <td>7.4.3 Bluetooth</td> 4470 <td>Added Android Automotive requirements.</td> 4471 </tr> 4472 <tr> 4473 <td>7.4.4. Near-Field Communications</td> 4474 <td>Clarified condition for when Host Card Emulation is a requirement.</td> 4475 </tr> 4476 <tr> 4477 <td>7.6.1. Minimum Memory and Storage</td> 4478 <td>Updated minimum memory requirements for lower resulution screen devices 4479 and added hard-limit requirement isLowRamDevice().</td> 4480 </tr> 4481 <tr> 4482 <td>7.6.2. Application Shared Storage</td> 4483 <td>Updated requirements when support for host machine access is mandatory.</td> 4484 </tr> 4485 <tr> 4486 <td>7.8.1. Microphone</td> 4487 <td>Added Android Automotive requirements.</td> 4488 </tr> 4489 <tr> 4490 <td>8.2. File I/O Access Performance</td> 4491 <td>Clarified requirements.</td> 4492 </tr> 4493 <tr> 4494 <td>9.8. Privacy</td> 4495 <td>Added privacy requirement for preloaded VPNs.</td> 4496 </tr> 4497 <tr> 4498 <td>9.9. Full-Disk Encryption</td> 4499 <td>Clarified condition when Full-Disk encryption support is mandatory.</td> 4500 </tr> 4501 <tr> 4502 <td>9.10. Verified Boot</td> 4503 <td>Clarified definition of verified boot.</td> 4504 </tr> 4505 <tr> 4506 <td>11. Updatable Software</td> 4507 <td>Clarified the OTA download requirement is allowed but not mandatory for 4508 Android Automotive implementations.</td> 4509 </tr> 4510</table> 4511 4512 4513<h1 id="13_contact_us">13. Contact Us</h1> 4514 4515 4516<p>You can join the android-compatibility forum <a href="https://groups.google.com/forum/#!forum/android-compatibility">[Resources, 109</a>] and ask for clarifications or bring up any issues that you think the document 4517does not cover.</p> 4518 4519<h1 id="14_resources">14. Resources</h1> 4520 4521 4522<p>1. IETF RFC2119 Requirement Levels: <a href="http://www.ietf.org/rfc/rfc2119.txt">http://www.ietf.org/rfc/rfc2119.txt</a></p> 4523 4524<p>2. Android Open Source Project: <a href="http://source.android.com/">http://source.android.com/</a></p> 4525 4526<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> 4527 4528<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> 4529 4530<p>5. API definitions and documentation: <a href="http://developer.android.com/reference/packages.html">http://developer.android.com/reference/packages.html</a></p> 4531 4532<p>6. 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> 4533 4534<p>7. 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> 4535 4536<p>8. Android 5.1 allowed version strings: <a href="http://source.android.com/compatibility/5.1/versions.html">http://source.android.com/compatibility/5.1/versions.html</a></p> 4537 4538<p>9. Telephony Provider: <a href="http://developer.android.com/reference/android/provider/Telephony.html">http://developer.android.com/reference/android/provider/Telephony.html</a></p> 4539 4540<p>10. 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> 4541 4542<p>11. 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> 4543 4544<p>12. 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> 4545 4546<p>13. WebView compatibility: <a href="http://www.chromium.org/">http://www.chromium.org/</a></p> 4547 4548<p>14. HTML5: <a href="http://html.spec.whatwg.org/multipage/">http://html.spec.whatwg.org/multipage/</a></p> 4549 4550<p>15. 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> 4551 4552<p>16. 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> 4553 4554<p>17. HTML5/W3C geolocation API: <a href="http://www.w3.org/TR/geolocation-API/">http://www.w3.org/TR/geolocation-API/</a></p> 4555 4556<p>18. HTML5/W3C webstorage API: <a href="http://www.w3.org/TR/webstorage/">http://www.w3.org/TR/webstorage/</a></p> 4557 4558<p>19. HTML5/W3C IndexedDB API: <a href="http://www.w3.org/TR/IndexedDB/">http://www.w3.org/TR/IndexedDB/</a></p> 4559 4560<p>20. Dalvik Executable Format and bytecode specification: available in the 4561Android source code, at dalvik/docs</p> 4562 4563<p>21. 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> 4564 4565<p>22. 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> 4566 4567<p>23. 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> 4568 4569<p>24. 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> 4570 4571<p>25. Notifications Resources: <a href="https://developer.android.com/design/patterns/notifications.html">https://developer.android.com/design/patterns/notifications.html</a> </p> 4572 4573<p>26. Search Manager: <a href="http://developer.android.com/reference/android/app/SearchManager.html">http://developer.android.com/reference/android/app/SearchManager.html</a> </p> 4574 4575<p>27. Toasts: <a href="http://developer.android.com/reference/android/widget/Toast.html">http://developer.android.com/reference/android/widget/Toast.html</a></p> 4576 4577<p>28. Themes: <a href="http://developer.android.com/guide/topics/ui/themes.html">http://developer.android.com/guide/topics/ui/themes.html</a></p> 4578 4579<p>29. 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> 4580 4581<p>30. 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> 4582 4583<p>31. 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> 4584 4585<p>32. Overview screen resources: <a href="http://developer.android.com/guide/components/recents.html">http://developer.android.com/guide/components/recents.html</a> </p> 4586 4587<p>33. 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> 4588 4589<p>34. 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> 4590 4591<p>35. 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> 4592 4593<p>36. 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> 4594 4595<p>37. Settings.Secure LOCATION_MODE:</p> 4596 4597<p><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> 4598 4599<p>38. Unicode 6.1.0: <a href="http://www.unicode.org/versions/Unicode6.1.0/">http://www.unicode.org/versions/Unicode6.1.0/</a></p> 4600 4601<p>39. 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> 4602 4603<p>40. 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> 4604 4605<p>41. Android Device Owner App:</p> 4606 4607<p><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> 4608 4609<p>42. 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> 4610 4611<p>43. 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> 4612 4613<p>44. Eyes Free project: <a href="http://code.google.com/p/eyes-free/">http://code.google.com/p/eyes-free</a></p> 4614 4615<p>45. 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> 4616 4617<p>46. Television Input Framework: <a href="https://source.android.com/devices/tv/index.html">https://source.android.com/devices/tv/index.html</a></p> 4618 4619<p>47. 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> 4620 4621<p>48. Android apk file description: <a href="http://developer.android.com/guide/components/fundamentals.html">http://developer.android.com/guide/components/fundamentals.html </a></p> 4622 4623<p>49. 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> 4624 4625<p>50. 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> 4626 4627<p>51. RTC Hardware Coding Requirements: <a href="http://www.webmproject.org/hardware/rtc-coding-requirements/">http://www.webmproject.org/hardware/rtc-coding-requirements/</a></p> 4628 4629<p>52. 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> 4630 4631<p>53. Android android.content.pm.PackageManager class and Hardware Features List:</p> 4632 4633<p><a href="http://developer.android.com/reference/android/content/pm/PackageManager.html">http://developer.android.com/reference/android/content/pm/PackageManager.html</a></p> 4634 4635<p>54. 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> 4636 4637<p>55. ADB: <a href="http://developer.android.com/tools/help/adb.html">http://developer.android.com/tools/help/adb.html</a> </p> 4638 4639<p>56. Dumpsys: <a href="https://source.android.com/devices/input/diagnostics.html">https://source.android.com/devices/input/diagnostics.html</a> </p> 4640 4641<p>57. DDMS: <a href="http://developer.android.com/tools/debugging/ddms.html">http://developer.android.com/tools/debugging/ddms.html</a> </p> 4642 4643<p>58. Monkey testing tool: <a href="http://developer.android.com/tools/help/monkey.html">http://developer.android.com/tools/help/monkey.html</a> </p> 4644 4645<p>59. SysyTrace tool: <a href="http://developer.android.com/tools/help/systrace.html">http://developer.android.com/tools/help/systrace.html</a></p> 4646 4647<p>60. Android Application Development-Related Settings:</p> 4648 4649<p><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> 4650 4651<p>61. 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> 4652 4653<p>62. 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> 4654 4655<p>63. RenderScript: <a href="http://developer.android.com/guide/topics/renderscript/">http://developer.android.com/guide/topics/renderscript/</a></p> 4656 4657<p>64. 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> 4658 4659<p>65. 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> 4660 4661<p>66. EGL Extension-EGL_ANDROID_RECORDABLE:</p> 4662 4663<p><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> 4664 4665<p>67. 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> 4666 4667<p>68. 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> 4668 4669<p>69. 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> 4670 4671<p>70. 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> 4672 4673<p>71. 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> 4674 4675<p>72. 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> 4676 4677<p>73. Android Open Source sensors: <a href="http://source.android.com/devices/sensors/">http://source.android.com/devices/sensors</a></p> 4678 4679<p>74. 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> 4680 4681<p>75. 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> 4682 4683<p>76. 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> 4684 4685<p>77. 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> 4686 4687<p>78. 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> 4688 4689<p>79. 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> 4690 4691<p>80. 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> 4692 4693<p>81. 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> 4694 4695<p>82. 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> 4696 4697<p>83. 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> 4698 4699<p>84. 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> 4700 4701<p>85. 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> 4702 4703<p>86. Android NFC Sharing Settings:</p> 4704 4705<p><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> 4706 4707<p>87. 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> 4708 4709<p>88. 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> 4710 4711<p>89. Content Resolver: <a href="http://developer.android.com/reference/android/content/ContentResolver.html">http://developer.android.com/reference/android/content/ContentResolver.html</a></p> 4712 4713<p>90. 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> 4714 4715<p>91. Camera: <a href="http://developer.android.com/reference/android/hardware/Camera.html">http://developer.android.com/reference/android/hardware/Camera.html</a></p> 4716 4717<p>92. 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> 4718 4719<p>93. 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> 4720 4721<p>94. Camera version support: <a href="http://source.android.com/devices/camera/versioning.html">http://source.android.com/devices/camera/versioning.html</a> </p> 4722 4723<p>95. Android DownloadManager: <a href="http://developer.android.com/reference/android/app/DownloadManager.html">http://developer.android.com/reference/android/app/DownloadManager.html</a></p> 4724 4725<p>96. Android File Transfer: <a href="http://www.android.com/filetransfer">http://www.android.com/filetransfer</a></p> 4726 4727<p>97. 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> 4728 4729<p>98. 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> 4730 4731<p>99. USB Charging Specification: <a href="http://www.usb.org/developers/docs/devclass_docs/USB_Battery_Charging_1.2.pdf">http://www.usb.org/developers/docs/devclass_docs/USB_Battery_Charging_1.2.pdf</a></p> 4732 4733<p>100. 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> 4734 4735<p>101. Wired audio headset: <a href="http://source.android.com/accessories/headset-spec.html">http://source.android.com/accessories/headset-spec.html</a> </p> 4736 4737<p>102. 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> 4738 4739<p>103. UserManager reference: <a href="http://developer.android.com/reference/android/os/UserManager.html">http://developer.android.com/reference/android/os/UserManager.html</a></p> 4740 4741<p>104. External Storage reference: <a href="http://source.android.com/devices/storage">http://source.android.com/devices/storage</a></p> 4742 4743<p>105. 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> 4744 4745<p>106. SMS Short Code: <a href="http://en.wikipedia.org/wiki/Short_code">http://en.wikipedia.org/wiki/Short_code</a></p> 4746 4747<p>107. 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> 4748 4749<p>108. Android Compatibility Program Overview: <a href="http://source.android.com/compatibility/index.html">http://source.android.com/compatibility/index.html</a></p> 4750 4751<p>109. Android Compatibility forum: <a href="https://groups.google.com/forum/#!forum/android-compatibility">https://groups.google.com/forum/#!forum/android-compatibility</a></p> 4752 4753<p>110. WebM project: <a href="http://www.webmproject.org/">http://www.webmproject.org/</a> </p> 4754 4755<p>111. 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> 4756 4757<p>112. 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> 4758 4759<p>113. 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> 4760 4761<p>Many of these resources are derived directly or indirectly from the Android 4762SDK, and will be functionally identical to the information in that SDK’s 4763documentation. In any cases where this Compatibility Definition or the 4764Compatibility Test Suite disagrees with the SDK documentation, the SDK 4765documentation is considered authoritative. Any technical details provided in 4766the references included above are considered by inclusion to be part of this 4767Compatibility Definition.</p> 4768 4769</div> 4770</body> 4771</html> 4772
