1<!DOCTYPE html> 2<head> 3<title>Android ANDROID_VERSION Compatibility Definition</title> 4<link rel="stylesheet" type="text/css" href="source/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_h2"><a href="#5_9_midi">5.9. Musical Instrument Digital Interface (MIDI)</a></p> 144 145<p class="toc_h1"><a href="#6_developer_tools_and_options_compatibility">6. Developer Tools and Options Compatibility</a></p> 146 147<p class="toc_h2"><a href="#6_1_developer_tools">6.1. Developer Tools</a></p> 148 149<p class="toc_h2"><a href="#6_2_developer_options">6.2. Developer Options</a></p> 150 151<p class="toc_h1"><a href="#7_hardware_compatibility">7. Hardware Compatibility</a></p> 152 153<p class="toc_h2"><a href="#7_1_display_and_graphics">7.1. Display and Graphics</a></p> 154 155<p class="toc_h3"><a href="#7_1_1_screen_configuration">7.1.1. Screen Configuration</a></p> 156 157<p class="toc_h4"><a href="#7_1_1_1_screen_size">7.1.1.1. Screen Size</a></p> 158 159<p class="toc_h4"><a href="#7_1_1_2_screen_aspect_ratio">7.1.1.2. Screen Aspect Ratio</a></p> 160 161<p class="toc_h4"><a href="#7_1_1_3_screen_density">7.1.1.3. Screen Density</a></p> 162 163 164</div> 165 166<div style="clear: both; page-break-after:always; height:1px"></div> 167 168 169<div id="toc_left_2"> 170 171<p class="toc_h3"><a href="#7_1_2_display_metrics">7.1.2. Display Metrics</a></p> 172 173<p class="toc_h3"><a href="#7_1_3_screen_orientation">7.1.3. Screen Orientation</a></p> 174 175<p class="toc_h3"><a href="#7_1_4_2d_and_3d_graphics_acceleration">7.1.4. 2D and 3D Graphics Acceleration</a></p> 176 177<p class="toc_h3"><a href="#7_1_5_legacy_application_compatibility_mode">7.1.5. Legacy Application Compatibility Mode</a></p> 178 179<p class="toc_h3"><a href="#7_1_6_screen_technology">7.1.6. Screen Technology</a></p> 180 181<p class="toc_h3"><a href="#7_1_7_external_displays">7.1.7. Secondary Displays</a></p> 182 183<p class="toc_h2"><a href="#7_2_input_devices">7.2. Input Devices</a></p> 184 185<p class="toc_h3"><a href="#7_2_1_keyboard">7.2.1. Keyboard</a></p> 186 187<p class="toc_h3"><a href="#7_2_2_non-touch_navigation">7.2.2. Non-touch Navigation</a></p> 188 189<p class="toc_h3"><a href="#7_2_3_navigation_keys">7.2.3. Navigation Keys</a></p> 190 191<p class="toc_h3"><a href="#7_2_4_touchscreen_input">7.2.4. Touchscreen Input</a></p> 192 193<p class="toc_h3"><a href="#7_2_5_fake_touch_input">7.2.5. Fake Touch Input</a></p> 194 195<p class="toc_h3"><a href="#7_2_6_game_controller_support">7.2.6. Game Controller Support</a></p> 196 197<p class="toc_h4"><a href="#7_2_6_1_button_mapping">7.2.6.1. Button Mappings</a></p> 198 199<p class="toc_h3"><a href="#7_2_7_remote_control">7.2.7. Remote Control</a></p> 200 201<p class="toc_h2"><a href="#7_3_sensors">7.3. Sensors</a></p> 202 203<p class="toc_h3"><a href="#7_3_1_accelerometer">7.3.1. Accelerometer</a></p> 204 205<p class="toc_h3"><a href="#7_3_2_magnetometer">7.3.2. Magnetometer</a></p> 206 207<p class="toc_h3"><a href="#7_3_3_gps">7.3.3. GPS</a></p> 208 209<p class="toc_h3"><a href="#7_3_4_gyroscope">7.3.4. Gyroscope</a></p> 210 211<p class="toc_h3"><a href="#7_3_5_barometer">7.3.5. Barometer</a></p> 212 213<p class="toc_h3"><a href="#7_3_6_thermometer">7.3.6. Thermometer</a></p> 214 215<p class="toc_h3"><a href="#7_3_7_photometer">7.3.7. Photometer</a></p> 216 217<p class="toc_h3"><a href="#7_3_8_proximity_sensor">7.3.8. Proximity Sensor</a></p> 218 219<p class="toc_h2"><a href="#7_4_data_connectivity">7.4. Data Connectivity</a></p> 220 221<p class="toc_h3"><a href="#7_4_1_telephony">7.4.1. Telephony</a></p> 222 223<p class="toc_h3"><a href="#7_4_2_ieee_80211_wi-fi">7.4.2. IEEE 802.11 (Wi-Fi)</a></p> 224 225<p class="toc_h4"><a href="#7_4_2_1_wi-fi_direct">7.4.2.1. Wi-Fi Direct</a></p> 226 227<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> 228 229<p class="toc_h3"><a href="#7_4_3_bluetooth">7.4.3. Bluetooth</a></p> 230 231<p class="toc_h3"><a href="#7_4_4_near-field_communications">7.4.4. Near-Field Communications</a></p> 232 233<p class="toc_h3"><a href="#7_4_5_minimum_network_capability">7.4.5. Minimum Network Capability</a></p> 234 235<p class="toc_h3"><a href="#7_4_6_sync_settings">7.4.6. Sync Settings</a></p> 236 237<p class="toc_h2"><a href="#7_5_cameras">7.5. Cameras</a></p> 238 239<p class="toc_h3"><a href="#7_5_1_rear-facing_camera">7.5.1. Rear-Facing Camera</a></p> 240 241<p class="toc_h3"><a href="#7_5_2_front-facing_camera">7.5.2. Front-Facing Camera</a></p> 242 243<p class="toc_h3"><a href="#7_5_3_external_camera">7.5.3. External Camera</a></p> 244 245<p class="toc_h3"><a href="#7_5_4_camera_api_behavior">7.5.4. Camera API Behavior</a></p> 246 247 248 249 250 251</div> 252 253<div id="toc_right_2"> 254 255<p class="toc_h3"><a href="#7_5_5_camera_orientation">7.5.5. Camera Orientation</a></p> 256 257<p class="toc_h2"><a href="#7_6_memory_and_storage">7.6. Memory and Storage</a></p> 258 259<p class="toc_h3"><a href="#7_6_1_minimum_memory_and_storage">7.6.1. Minimum Memory and Storage</a></p> 260 261<p class="toc_h3"><a href="#7_6_2_application_shared_storage">7.6.2. Application Shared Storage</a></p> 262 263<p class="toc_h2"><a href="#7_7_usb">7.7. USB</a></p> 264 265<p class="toc_h2"><a href="#7_8_audio">7.8. Audio</a></p> 266 267<p class="toc_h3"><a href="#7_8_1_microphone">7.8.1. Microphone</a></p> 268 269<p class="toc_h3"><a href="#7_8_2_audio_output">7.8.2. Audio Output</a></p> 270 271<p class="toc_h4"><a href="#7_8_2_1_analog_audio_ports">7.8.2.1. Analog Audio Ports</a></p> 272 273<p class="toc_h1"><a href="#8_performance_compatibility">8. Performance Compatibility</a></p> 274 275<p class="toc_h2"><a href="#8_1_user_experience_consistency">8.1. User Experience Consistency</a></p> 276 277<p class="toc_h2"><a href="#8_2_memory_performance">8.2. Memory Performance</a></p> 278 279<p class="toc_h1"><a href="#9_security_model_compatibility">9. Security Model Compatibility</a></p> 280 281<p class="toc_h2"><a href="#9_1_permissions">9.1. Permissions</a></p> 282 283<p class="toc_h2"><a href="#9_2_uid_and_process_isolation">9.2. UID and Process Isolation</a></p> 284 285<p class="toc_h2"><a href="#9_3_filesystem_permissions">9.3. Filesystem Permissions</a></p> 286 287<p class="toc_h2"><a href="#9_4_alternate_execution_environments">9.4. Alternate Execution Environments</a></p> 288 289<p class="toc_h2"><a href="#9_5_multi-user_support">9.5. Multi-User Support</a></p> 290 291<p class="toc_h2"><a href="#9_6_premium_sms_warning">9.6. Premium SMS Warning</a></p> 292 293<p class="toc_h2"><a href="#9_7_kernel_security_features">9.7. Kernel Security Features</a></p> 294 295<p class="toc_h2"><a href="#9_8_privacy">9.8. Privacy</a></p> 296 297<p class="toc_h2"><a href="#9_9_full-disk-encryption">9.9. Full-Disk Encryption</a></p> 298 299<p class="toc_h2"><a href="#9_10_verified_boot">9.10. Verified Boot</a></p> 300 301<p class="toc_h1"><a href="#10_software_compatibility_testing">10. Software Compatibility Testing</a></p> 302 303<p class="toc_h2"><a href="#10_1_compatibility_test_suite">10.1. Compatibility Test Suite</a></p> 304 305<p class="toc_h2"><a href="#10_2_cts_verifier">10.2. CTS Verifier</a></p> 306 307<p class="toc_h1"><a href="#11_updatable_software">11. Updatable Software</a></p> 308 309<p class="toc_h1"><a href="#12_document_changelog">12. Document Changelog</a></p> 310 311<p class="toc_h1"><a href="#13_contact_us">13. Contact Us</a></p> 312 313<p class="toc_h1"><a href="#14_resources">14. Resources</a></p> 314 315</div> 316 317</div> 318 319<div style="clear: both"></div> 320 321<div id="main"> 322 323<h1 id="1_introduction">1. Introduction</h1> 324 325 326<p>This document enumerates the requirements that must be met in order for devices 327to be compatible with Android ANDROID_VERSION.</p> 328 329<p>The use of “MUST”, “MUST NOT”, “REQUIRED”, “SHALL”, “SHALL NOT”, “SHOULD”,“SHOULD NOT”, “RECOMMENDED”, “MAY”, and “OPTIONAL” is per the IETF standard 330defined in RFC2119 [<a href="http://www.ietf.org/rfc/rfc2119.txt">Resources, 1</a>].</p> 331 332<p>As used in this document, a “device implementer” or “implementer” is a person 333or organization developing a hardware/software solution running Android ANDROID_VERSION. A 334“device implementation” or “implementation is the hardware/software solution 335so developed.</p> 336 337<p>To be considered compatible with Android ANDROID_VERSION, device implementations MUST meet 338the requirements presented in this Compatibility Definition, including any 339documents incorporated via reference.</p> 340 341<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 342implementer to ensure compatibility with existing implementations.</p> 343 344<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 345implementers are strongly encouraged to base their implementations to the 346greatest extent possible on the “upstream” source code available from the 347Android Open Source Project. While some components can hypothetically be 348replaced with alternate implementations this practice is strongly discouraged, 349as passing the software tests will become substantially more difficult. It is 350the implementer’s responsibility to ensure full behavioral compatibility with 351the standard Android implementation, including and beyond the Compatibility 352Test Suite. Finally, note that certain component substitutions and 353modifications are explicitly forbidden by this document.</p> 354 355<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 356functionally identical to the information in that SDK’s documentation. For any 357case where this Compatibility Definition or the Compatibility Test Suite 358disagrees with the SDK documentation, the SDK documentation is considered 359authoritative. 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> 360 361<h1 id="2_device_types">2. Device Types</h1> 362 363 364<p>While the Android Open Source Project has been used in the implementation of a 365variety of device types and form factors, many aspects of the architecture and 366compatibility requirements were optimized for handheld devices. Starting from 367Android 5.0, the Android Open Source Project aims to embrace a wider variety of 368device types as described in this section.</p> 369 370<p><strong>Android Handheld device</strong> refers to an Android device implementation that is typically used by holding 371it in the hand, such as mp3 players, phones, and tablets. Android Handheld 372device implementations:</p> 373 374<ul> 375 <li>MUST have a touchscreen embedded in the device.</li> 376 <li>MUST have a power source that provides mobility, such as a battery.</li> 377</ul> 378 379<p><strong>Android Television device</strong> refers to an Android device implementation that is an entertainment interface 380for consuming digital media, movies, games, apps, and/or live TV for users 381sitting about ten feet away (a “lean back” or “10-foot user interface”). 382Android Television devices:</p> 383 384<ul> 385 <li>MUST have an embedded screen OR include a video output port, such as VGA, HDMI, 386or a wireless port for display.</li> 387 <li>MUST declare the features android.software.leanback and 388android.hardware.type.television [<a href="http://developer.android.com/reference/android/content/pm/PackageManager.html#FEATURE_LEANBACK">Resources, 3</a>].</li> 389</ul> 390 391<p><strong>Android Watch device</strong> refers to an Android device implementation intended to be worn on the body, 392perhaps on the wrist, and:</p> 393 394<ul> 395 <li>MUST have a screen with the physical diagonal length in the range from 1.1 to 3962.5 inches.</li> 397 <li>MUST declare the feature android.hardware.type.watch.</li> 398 <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> 399</ul> 400 401<p><strong>Android Automotive implementation</strong> refers to a vehicle head 402unit running Android as an operating system for part or all of the system and/or 403infotainment functionality. Android Automotive implementations MUST support 404uiMode = UI_MODE_TYPE_CAR [<a href="http://developer.android.com/reference/android/content/res/Configuration.html#UI_MODE_TYPE_CAR">Resources, 111</a>].</p> 405 406<p>All Android device implementations that do not fit into any of the above device 407types still MUST meet all requirements in this document to be Android ANDROID_VERSION 408compatible, unless the requirement is explicitly described to be only 409applicable to a specific Android device type from above.</p> 410 411<h2 id="2_1_device_configurations">2.1 Device Configurations</h2> 412 413 414<p>This is a summary of major differences in hardware configuration by device 415type. (Empty cells denote a “MAY”). Not all configurations are covered in this 416table; see relevant hardware sections for more detail.</p> 417<table> 418 <tr> 419 <th>Category</th> 420 <th>Feature</th> 421 <th>Section</th> 422 <th>Handheld</th> 423 <th>Television</th> 424 <th>Watch</th> 425 <th>Automotive</th> 426 <th>Other</th> 427 </tr> 428 <tr> 429 <td rowspan="3">Input</td> 430 <td>D-pad</td> 431 <td><a href="#7_2_2_non-touch-navigation">7.2.2. Non-touch Navigation</a></td> 432 <td></td> 433 <td>MUST</td> 434 <td></td> 435 <td></td> 436 <td></td> 437 </tr> 438 <tr> 439 <td>Touchscreen </td> 440 <td><a href="#7_2_4_touchscreen_input">7.2.4. Touchscreen input</a></td> 441 <td>MUST</td> 442 <td></td> 443 <td>MUST</td> 444 <td></td> 445 <td>SHOULD</td> 446 </tr> 447 <tr> 448 <td>Microphone </td> 449 <td><a href="#7_8_1_microphone">7.8.1. Microphone</a></td> 450 <td>MUST</td> 451 <td>SHOULD </td> 452 <td>MUST</td> 453 <td>MUST</td> 454 <td>SHOULD</td> 455 </tr> 456 <tr> 457 <td rowspan="2">Sensors</td> 458 <td>Accelerometer </td> 459 <td><a href="#7_3_1_accelerometer">7.3.1 Accelerometer</a></td> 460 <td>SHOULD</td> 461 <td></td> 462 <td>SHOULD</td> 463 <td></td> 464 <td>SHOULD</td> 465 </tr> 466 <tr> 467 <td>GPS</td> 468 <td><a href="#7_3_3_gps">7.3.3. GPS</a></td> 469 <td>SHOULD</td> 470 <td></td> 471 <td></td> 472 <td>SHOULD</td> 473 <td></td> 474 </tr> 475 <tr> 476 <td rowspan="5">Connectivity</td> 477 <td>Wi-Fi</td> 478 <td><a href="#7_4_2_ieee_802.11">7.4.2. IEEE 802.11</a></td> 479 <td>SHOULD</td> 480 <td> MUST</td> 481 <td></td> 482 <td>SHOULD</td> 483 <td>SHOULD</td> 484 </tr> 485 <tr> 486 <td>Wi-Fi Direct</td> 487 <td><a href="#7_4_2_1_wi-fi-direct">7.4.2.1. Wi-Fi Direct</a></td> 488 <td>SHOULD</td> 489 <td>SHOULD</td> 490 <td></td> 491 <td></td> 492 <td>SHOULD</td> 493 </tr> 494 <tr> 495 <td>Bluetooth</td> 496 <td><a href="#7_4_3_bluetooth">7.4.3. Bluetooth</a></td> 497 <td>SHOULD</td> 498 <td>MUST</td> 499 <td>MUST</td> 500 <td>MUST</td> 501 <td>SHOULD</td> 502 </tr> 503 <tr> 504 <td>Bluetooth Low Energy</td> 505 <td><a href="#7_4_3_bluetooth">7.4.3. Bluetooth</a></td> 506 <td>SHOULD</td> 507 <td>MUST</td> 508 <td>SHOULD</td> 509 <td>SHOULD</td> 510 <td>SHOULD</td> 511 </tr> 512 <tr> 513 <td>USB peripheral/host mode</td> 514 <td><a href="#7_7_usb">7.7. USB</a></td> 515 <td>SHOULD</td> 516 <td></td> 517 <td></td> 518 <td>SHOULD</td> 519 <td>SHOULD</td> 520 </tr> 521 <tr> 522 <td>Output</td> 523 <td>Speaker and/or Audio output ports</td> 524 <td><a href="#7_8_2_audio_output">7.8.2. Audio Output</a></td> 525 <td>MUST</td> 526 <td>MUST</td> 527 <td></td> 528 <td>MUST</td> 529 <td>MUST</td> 530 </tr> 531</table> 532 533 534<h1 id="3_software">3. Software</h1> 535 536 537<h2 id="3_1_managed_api_compatibility">3.1. Managed API Compatibility</h2> 538 539 540<p>The managed Dalvik bytecode execution environment is the primary vehicle for 541Android applications. The Android application programming interface (API) is 542the set of Android platform interfaces exposed to applications running in the 543managed runtime environment. Device implementations MUST provide complete 544implementations, including all documented behaviors, of any documented API 545exposed 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 546source code. </p> 547 548<p>Device implementations MUST NOT omit any managed APIs, alter API interfaces or 549signatures, deviate from the documented behavior, or include no-ops, except 550where specifically allowed by this Compatibility Definition.</p> 551 552<p>This Compatibility Definition permits some types of hardware for which Android 553includes APIs to be omitted by device implementations. In such cases, the APIs 554MUST 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> 555 556<h2 id="3_2_soft_api_compatibility">3.2. Soft API Compatibility</h2> 557 558 559<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 560such things as intents, permissions, and similar aspects of Android 561applications that cannot be enforced at application compile time.</p> 562 563<h3 id="3_2_1_permissions">3.2.1. Permissions</h3> 564 565 566<p>Device implementers MUST support and enforce all permission constants as 567documented 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> 568 569<h3 id="3_2_2_build_parameters">3.2.2. Build Parameters</h3> 570 571 572<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, 573meaningful values across device implementations, the table below includes 574additional restrictions on the formats of these values to which device 575implementations MUST conform.</p> 576<table> 577 <tr> 578 <th>Parameter</th> 579 <th>Details</th> 580 </tr> 581 <tr> 582 <td>VERSION.RELEASE</td> 583 <td>The version of the currently-executing Android system, in human-readable 584format. This field MUST have one of the string values defined in [<a href="http://source.android.com/compatibility/ANDROID_VERSION/versions.html">Resources, 8]</a>.</td> 585 </tr> 586 <tr> 587 <td>VERSION.SDK</td> 588 <td>The version of the currently-executing Android system, in a format accessible 589to third-party application code. For Android ANDROID_VERSION, this field MUST have the 590integer value 22.</td> 591 </tr> 592 <tr> 593 <td>VERSION.SDK_INT</td> 594 <td>The version of the currently-executing Android system, in a format accessible 595to third-party application code. For Android ANDROID_VERSION, this field MUST have the 596integer value 22.</td> 597 </tr> 598 <tr> 599 <td>VERSION.INCREMENTAL</td> 600 <td>A value chosen by the device implementer designating the specific build of the 601currently-executing Android system, in human-readable format. This value MUST 602NOT be reused for different builds made available to end users. A typical use 603of this field is to indicate which build number or source-control change 604identifier was used to generate the build. There are no requirements on the 605specific format of this field, except that it MUST NOT be null or the empty 606string ("").</td> 607 </tr> 608 <tr> 609 <td>BOARD</td> 610 <td>A value chosen by the device implementer identifying the specific internal 611hardware used by the device, in human-readable format. A possible use of this 612field is to indicate the specific revision of the board powering the device. 613The value of this field MUST be encodable as 7-bit ASCII and match the regular 614expression “^[a-zA-Z0-9_-]+$”.</td> 615 </tr> 616 <tr> 617 <td>BRAND</td> 618 <td>A value reflecting the brand name associated with the device as known to the 619end users. MUST be in human-readable format and SHOULD represent the 620manufacturer of the device or the company brand under which the device is 621marketed. The value of this field MUST be encodable as 7-bit ASCII and match 622the regular expression “^[a-zA-Z0-9_-]+$”.</td> 623 </tr> 624 <tr> 625 <td>SUPPORTED_ABIS</td> 626 <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> 627 </tr> 628 <tr> 629 <td>SUPPORTED_32_BIT_ABIS</td> 630 <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> 631 </tr> 632 <tr> 633 <td>SUPPORTED_64_BIT_ABIS</td> 634 <td>The name of the second instruction set (CPU type + ABI convention) of native 635code. See <a href="#3_3_native_api_compatibility">section 3.3. Native API Compatibility</a>.</td> 636 </tr> 637 <tr> 638 <td>CPU_ABI</td> 639 <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> 640 </tr> 641 <tr> 642 <td>CPU_ABI2</td> 643 <td>The name of the second instruction set (CPU type + ABI convention) of native 644code. See <a href="#3_3_native_api_compatibility">section 3.3. Native API Compatibility</a>.</td> 645 </tr> 646 <tr> 647 <td>DEVICE</td> 648 <td>A value chosen by the device implementer containing the development name or 649code name identifying the configuration of the hardware features and industrial 650design of the device. The value of this field MUST be encodable as 7-bit ASCII 651and match the regular expression “^[a-zA-Z0-9_-]+$”.</td> 652 </tr> 653 <tr> 654 <td>FINGERPRINT</td> 655 <td>A string that uniquely identifies this build. It SHOULD be reasonably 656human-readable. It MUST follow this template:</p> 657 658<p class="small">$(BRAND)/$(PRODUCT)/$(DEVICE):$(VERSION.RELEASE)/$(ID)/$(VERSION.INCREMENTAL):$(TYPE)/$(TAGS)</p> 659 660<p>For example: acme/myproduct/mydevice:ANDROID_VERSION/LMYXX/3359:userdebug/test-keys</p> 661 662<p>The fingerprint MUST NOT include whitespace characters. If other fields 663included in the template above have whitespace characters, they MUST be 664replaced in the build fingerprint with another character, such as the 665underscore ("_") character. The value of this field MUST be encodable as 7-bit 666ASCII.</td> 667 </tr> 668 <tr> 669 <td>HARDWARE</td> 670 <td>The name of the hardware (from the kernel command line or /proc). It SHOULD be 671reasonably human-readable. The value of this field MUST be encodable as 7-bit 672ASCII and match the regular expression “^[a-zA-Z0-9_-]+$”. </td> 673 </tr> 674 <tr> 675 <td>HOST</td> 676 <td>A string that uniquely identifies the host the build was built on, in 677human-readable format. There are no requirements on the specific format of this 678field, except that it MUST NOT be null or the empty string ("").</td> 679 </tr> 680 <tr> 681 <td>ID</td> 682 <td>An identifier chosen by the device implementer to refer to a specific release, 683in human-readable format. This field can be the same as 684android.os.Build.VERSION.INCREMENTAL, but SHOULD be a value sufficiently 685meaningful for end users to distinguish between software builds. The value of 686this field MUST be encodable as 7-bit ASCII and match the regular expression “^[a-zA-Z0-9._-]+$”.</td> 687 </tr> 688 <tr> 689 <td>MANUFACTURER</td> 690 <td>The trade name of the Original Equipment Manufacturer (OEM) of the product. 691There are no requirements on the specific format of this field, except that it 692MUST NOT be null or the empty string ("").</td> 693 </tr> 694 <tr> 695 <td>MODEL</td> 696 <td>A value chosen by the device implementer containing the name of the device as 697known to the end user. This SHOULD be the same name under which the device is 698marketed and sold to end users. There are no requirements on the specific 699format of this field, except that it MUST NOT be null or the empty string ("").</td> 700 </tr> 701 <tr> 702 <td>PRODUCT</td> 703 <td>A value chosen by the device implementer containing the development name or 704code name of the specific product (SKU) that MUST be unique within the same 705brand. MUST be human-readable, but is not necessarily intended for view by end 706users. The value of this field MUST be encodable as 7-bit ASCII and match the 707regular expression “^[a-zA-Z0-9_-]+$”.</td> 708 </tr> 709 <tr> 710 <td>SERIAL</td> 711 <td>A hardware serial number, which MUST be available. The value of this field MUST 712be encodable as 7-bit ASCII and match the regular expression “^([a-zA-Z0-9]{6,20})$”.</td> 713 </tr> 714 <tr> 715 <td>TAGS</td> 716 <td>A comma-separated list of tags chosen by the device implementer that further 717distinguishes the build. This field MUST have one of the values corresponding 718to the three typical Android platform signing configurations: release-keys, 719dev-keys, test-keys. </td> 720 </tr> 721 <tr> 722 <td>TIME</td> 723 <td>A value representing the timestamp of when the build occurred.</td> 724 </tr> 725 <tr> 726 <td>TYPE</td> 727 <td>A value chosen by the device implementer specifying the runtime configuration 728of the build. This field MUST have one of the values corresponding to the three 729typical Android runtime configurations: user, userdebug, or eng.</td> 730 </tr> 731 <tr> 732 <td>USER</td> 733 <td>A name or user ID of the user (or automated user) that generated the build. 734There are no requirements on the specific format of this field, except that it 735MUST NOT be null or the empty string ("").</td> 736 </tr> 737</table> 738 739 740<h3 id="3_2_3_intent_compatibility">3.2.3. Intent Compatibility</h3> 741 742 743<p>Device implementations MUST honor Android’s loose-coupling intent system, as 744described in the sections below. By“honored ” it is meant that the device 745implementer MUST provide an Android Activity or Service that specifies a 746matching intent filter that binds to and implements correct behavior for each 747specified intent pattern.</p> 748 749<h4 id="3_2_3_1_core_application_intents">3.2.3.1. Core Application Intents</h4> 750 751 752<p>Android intents allow application components to request functionality from 753other Android components. The Android upstream project includes a list of 754applications considered core Android applications, which implements several 755intent patterns to perform common actions. The core Android applications are:</p> 756 757<ul> 758 <li>Desk Clock</li> 759 <li>Browser</li> 760 <li>Calendar</li> 761 <li>Contacts</li> 762 <li>Gallery</li> 763 <li>GlobalSearch</li> 764 <li>Launcher</li> 765 <li>Music</li> 766 <li>Settings</li> 767</ul> 768 769<p>Device implementations SHOULD include the core Android applications as 770appropriate but MUST include a component implementing the same intent patterns 771defined by all the “public” Activity or Service components of these core 772Android applications. Note that Activity or Service components are considered 773“public” when the attribute android:exported is absent or has the value true.</p> 774 775<h4 id="3_2_3_2_intent_overrides">3.2.3.2. Intent Overrides</h4> 776 777 778<p>As Android is an extensible platform, device implementations MUST allow each 779intent 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 780implementation allows this by default; device implementers MUST NOT attach 781special privileges to system applications' use of these intent patterns, or 782prevent third-party applications from binding to and assuming control of these 783patterns. This prohibition specifically includes but is not limited to 784disabling the“Chooser” user interface that allows the user to select between 785multiple applications that all handle the same intent pattern.</p> 786 787<p>However, device implementations MAY provide default activities for specific URI 788patterns (eg. http://play.google.com) if the default activity provides a more 789specific filter for the data URI. For example, an intent filter specifying the 790data URI “http://www.android.com” is more specific than the browser filter for“http://”. Device implementations MUST provide a user interface for users to 791modify the default activity for intents.</p> 792 793<h4 id="3_2_3_3_intent_namespaces">3.2.3.3. Intent Namespaces</h4> 794 795 796<p>Device implementations MUST NOT include any Android component that honors any 797new intent or broadcast intent patterns using an ACTION, CATEGORY, or other key 798string in the android.* or com.android.* namespace. Device implementers MUST 799NOT include any Android components that honor any new intent or broadcast 800intent patterns using an ACTION, CATEGORY, or other key string in a package 801space belonging to another organization. Device implementers MUST NOT alter or 802extend 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 803and obviously associated with their own organization. This prohibition is 804analogous to that specified for Java language classes in <a href="#3_6_api_namespaces">section 3.6</a>.</p> 805 806<h4 id="3_2_3_4_broadcast_intents">3.2.3.4. Broadcast Intents</h4> 807 808 809<p>Third-party applications rely on the platform to broadcast certain intents to 810notify them of changes in the hardware or software environment. 811Android-compatible devices MUST broadcast the public broadcast intents in 812response to appropriate system events. Broadcast intents are described in the 813SDK documentation.</p> 814 815<h4 id="3_2_3_5_default_app_settings">3.2.3.5. Default App Settings</h4> 816 817 818<p>Android includes settings that provide users an easy way to select their 819default applications, for example for Home screen or SMS. Where it makes sense, 820device implementations MUST provide a similar settings menu and be compatible 821with the intent filter pattern and API methods described in the SDK 822documentation as below.</p> 823 824<p>Device implementations:</p> 825 826<ul> 827 <li>MUST honor the android.settings.HOME_SETTINGS intent to show a default app 828settings menu for Home Screen, if the device implementation reports 829android.software.home_screen [<a href="http://developer.android.com/reference/android/provider/Settings.html">Resources, 10]</a></li> 830 <li>MUST provide a settings menu that will call the 831android.provider.Telephony.ACTION_CHANGE_DEFAULT intent to show a dialog to 832change the default SMS application, if the device implementation reports 833android.hardware.telephony [<a href="http://developer.android.com/reference/android/provider/Telephony.Sms.Intents.html">Resources, 9</a>]</li> 834 <li>MUST honor the android.settings.NFC_PAYMENT_SETTINGS intent to show a default 835app settings menu for Tap and Pay, if the device implementation reports 836android.hardware.nfc.hce [<a href="http://developer.android.com/reference/android/provider/Settings.html">Resources, 10]</a></li> 837</ul> 838 839<h2 id="3_3_native_api_compatibility">3.3. Native API Compatibility</h2> 840 841 842<h3 id="3_3_1_application_binary_interfaces">3.3.1. Application Binary Interfaces</h3> 843 844 845<p>Managed Dalvik bytecode can call into native code provided in the application 846.apk file as an ELF .so file compiled for the appropriate device hardware 847architecture. As native code is highly dependent on the underlying processor 848technology, Android defines a number of Application Binary Interfaces (ABIs) in 849the Android NDK. Device implementations MUST be compatible with one or more 850defined ABIs, and MUST implement compatibility with the Android NDK, as below.</p> 851 852<p>If a device implementation includes support for an Android ABI, it:</p> 853 854<ul> 855 <li>MUST include support for code running in the managed environment to call into 856native code, using the standard Java Native Interface (JNI) semantics</li> 857 <li>MUST be source-compatible (i.e. header compatible) and binary-compatible (for 858the ABI) with each required library in the list below</li> 859 <li>MUST support the equivalent 32-bit ABI if any 64-bit ABI is supported</li> 860 <li>MUST accurately report the native Application Binary Interface (ABI) supported 861by the device, via the android.os.Build.SUPPORTED_ABIS, 862android.os.Build.SUPPORTED_32_BIT_ABIS, and 863android.os.Build.SUPPORTED_64_BIT_ABIS parameters, each a comma separated list 864of ABIs ordered from the most to the least preferred one</li> 865 <li>MUST report, via the above parameters, only those ABIs documented in the latest 866version of the Android NDK, “NDK Programmer’s Guide | ABI Management” in docs/ 867directory</li> 868 <li>SHOULD be built using the source code and header files available in the 869upstream Android Open Source Project</li> 870</ul> 871 872<p>The following native code APIs MUST be available to apps that include native 873code:</p> 874 875<ul> 876 <li>libc (C library)</li> 877 <li>libm (math library)</li> 878 <li>Minimal support for C++</li> 879 <li>JNI interface</li> 880 <li>liblog (Android logging)</li> 881 <li>libz (Zlib compression)</li> 882 <li>libdl (dynamic linker)</li> 883 <li>libGLESv1_CM.so (OpenGL ES 1.x)</li> 884 <li>libGLESv2.so (OpenGL ES 2.0)</li> 885 <li>libGLESv3.so (OpenGL ES 3.x)</li> 886 <li>libEGL.so (native OpenGL surface management)</li> 887 <li>libjnigraphics.so</li> 888 <li>libOpenSLES.so (OpenSL ES 1.0.1 audio support)</li> 889 <li>libOpenMAXAL.so (OpenMAX AL 1.0.1 support)</li> 890 <li>libandroid.so (native Android activity support)</li> 891 <li>libmediandk.so (native media APIs support)</li> 892 <li>Support for OpenGL, as described below</li> 893</ul> 894 895<p>Note that future releases of the Android NDK may introduce support for 896additional ABIs. If a device implementation is not compatible with an existing 897predefined ABI, it MUST NOT report support for any ABIs at all.</p> 898 899<p>Note that device implementations MUST include libGLESv3.so and it MUST symlink 900(symbolic link) to libGLESv2.so. in turn, MUST export all the OpenGL ES 3.1 and 901Android 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 902symbols must be present, only the corresponding functions for OpenGL ES 903versions and extensions actually supported by the device must be fully 904implemented.</p> 905 906<p>Native code compatibility is challenging. For this reason, device implementers 907are <strong>very strongly encouraged</strong> to use the implementations of the libraries listed above from the upstream 908Android Open Source Project. </p> 909 910<h3 id="3_3_2_32-bit_arm_native_code_compatibility"> 9113.3.2. 32-bit ARM Native Code Compatibility 912</h3> 913 914<p>The ARMv8 architecture deprecates several CPU operations, including some 915operations used in existing native code. On 64-bit ARM devices, the following 916deprecated operations MUST remain available to 32-bit native ARM code, either 917through native CPU support or through software emulation:</p> 918 919<ul> 920<li>SWP and SWPB instructions</li> 921<li>SETEND instruction</li> 922<li>CP15ISB, CP15DSB, and CP15DMB barrier operations</li> 923</ul> 924 925<p>Legacy versions of the Android NDK used /proc/cpuinfo to discover CPU features 926from 32-bit ARM native code. For compatibility with applications built using this 927NDK, devices MUST include the following lines in /proc/cpuinfo when it is read 928by 32-bit ARM applications:</p> 929 930<ul> 931<li>"Features: ", followed by a list of any optional ARMv7 CPU features 932supported by the device</li> 933<li>"CPU architecture: ", followed by an integer describing the device's 934highest supported ARM architecture (e.g., "8" for ARMv8 devices)</li> 935</ul> 936 937<p>These requirements only apply when /proc/cpuinfo is read by 32-bit ARM 938applications. Devices SHOULD not alter /proc/cpuinfo when read by 64-bit ARM or 939non-ARM applications.</p> 940 941<h2 id="3_4_web_compatibility">3.4. Web Compatibility</h2> 942 943 944<h3 id="3_4_1_webview_compatibility">3.4.1. WebView Compatibility</h3> 945 946<div class="note"> 947<p>Android Watch devices MAY, but all other device implementations MUST provide 948a complete implementation of the android.webkit.Webview API.</p> 949</div> 950 951 952<p>The platform feature android.software.webview MUST be reported on any device 953that provides a complete implementation of the android.webkit.WebView API, and 954MUST NOT be reported on devices without a complete implementation of the API. 955The Android Open Source implementation uses code from the Chromium Project to 956implement 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 957rendering system, device implementers MUST use the specific upstream build of 958Chromium in the WebView implementation. Specifically:</p> 959 960<ul> 961 <li>Device android.webkit.WebView implementations MUST be based on the Chromium 962build from the upstream Android Open Source Project for Android ANDROID_VERSION. This build 963includes a specific set of functionality and security fixes for the WebView [<a href="http://www.chromium.org/">Resources, 13</a>].</li> 964 <li>The user agent string reported by the WebView MUST be in this format: 965<p>Mozilla/5.0 (Linux; Android $(VERSION); $(MODEL) Build/$(BUILD)$(WEBVIEW)) 966AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 $(CHROMIUM_VER) Mobile 967Safari/537.36</p> 968 <ul> 969 <li>The value of the $(VERSION) string MUST be the same as the value for 970android.os.Build.VERSION.RELEASE.</li> 971 <li>The $(WEBVIEW) string MAY be omitted, but if included MUST be "; wv" to 972 note that this is a webview</li> 973 <li>The value of the $(MODEL) string MUST be the same as the value for 974android.os.Build.MODEL.</li> 975 <li>The value of the $(BUILD) string MUST be the same as the value for 976android.os.Build.ID.</li> 977 <li>The value of the $(CHROMIUM_VER) string MUST be the version of Chromium in the 978upstream Android Open Source Project.</li> 979 <li>Device implementations MAY omit Mobile in the user agent string.</li> 980 </ul></li></ul> 981 982<p>The WebView component SHOULD include support for as many HTML5 features as 983possible and if it supports the feature SHOULD conform to the HTML5 984specification [<a href="http://html.spec.whatwg.org/multipage/">Resources, 14</a>].</p> 985 986<h3 id="3_4_2_browser_compatibility">3.4.2. Browser Compatibility</h3> 987 988<div class="note"> 989<p>Android Television, Watch, and Android Automotive implementations MAY omit a 990browser application, but MUST support the public intent patterns as described in 991<a href="#3_2_3_1_core_application_intents">section 3.2.3.1</a>. All other types 992of device implementations MUST include a standalone Browser application for 993general user web browsing.</p> 994</div> 995 996<p>The standalone Browser MAY be based on a browser technology other than WebKit. 997However, even if an alternate Browser application is used, the 998android.webkit.WebView component provided to third-party applications MUST be 999based on WebKit, as described in <a href="#3_4_1_webview_compatibility">section 3.4.1</a>.</p> 1000 1001<p>Implementations MAY ship a custom user agent string in the standalone Browser 1002application.</p> 1003 1004<p>The standalone Browser application (whether based on the upstream WebKit 1005Browser application or a third-party replacement) SHOULD include support for as 1006much of HTML5 [<a href="http://html.spec.whatwg.org/multipage/">Resources, 14</a>] as possible. Minimally, device implementations MUST support each of these 1007APIs associated with HTML5:</p> 1008 1009<ul> 1010 <li>application cache/offline operation [<a href="http://www.w3.org/html/wg/drafts/html/master/browsers.html#offline">Resources, 15</a>]</li> 1011 <li>the <video> tag [<a href="http://www.w3.org/html/wg/drafts/html/master/semantics.html#video">Resources, 16</a>]</li> 1012 <li>geolocation [<a href="http://www.w3.org/TR/geolocation-API/">Resources, 17</a>]</li> 1013</ul> 1014 1015<p>Additionally, device implementations MUST support the HTML5/W3C webstorage API 1016[<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 1017IndexedDB over webstorage, IndexedDB is expected to become a required component 1018in a future version of Android.</p> 1019 1020<h2 id="3_5_api_behavioral_compatibility">3.5. API Behavioral Compatibility</h2> 1021 1022 1023<p>The behaviors of each of the API types (managed, soft, native, and web) must be 1024consistent with the preferred implementation of the upstream Android Open 1025Source Project [<a href="http://source.android.com/">Resources, 2</a>]. Some specific areas of compatibility are:</p> 1026 1027<ul> 1028 <li>Devices MUST NOT change the behavior or semantics of a standard intent.</li> 1029 <li>Devices MUST NOT alter the lifecycle or lifecycle semantics of a particular 1030type of system component (such as Service, Activity, ContentProvider, etc.).</li> 1031 <li>Devices MUST NOT change the semantics of a standard permission.</li> 1032</ul> 1033 1034<p>The above list is not comprehensive. The Compatibility Test Suite (CTS) tests 1035significant portions of the platform for behavioral compatibility, but not all. 1036It is the responsibility of the implementer to ensure behavioral compatibility 1037with the Android Open Source Project. For this reason, device implementers 1038SHOULD use the source code available via the Android Open Source Project where 1039possible, rather than re-implement significant parts of the system.</p> 1040 1041<h2 id="3_6_api_namespaces">3.6. API Namespaces</h2> 1042 1043 1044<p>Android follows the package and class namespace conventions defined by the Java 1045programming language. To ensure compatibility with third-party applications, 1046device implementers MUST NOT make any prohibited modifications (see below) to 1047these package namespaces:</p> 1048 1049<ul> 1050 <li>java.*</li> 1051 <li>javax.*</li> 1052 <li>sun.*</li> 1053 <li>android.*</li> 1054 <li>com.android.*</li> 1055</ul> 1056 1057<p><strong>Prohibited modifications include</strong>:</p> 1058 1059<ul> 1060 <li>Device implementations MUST NOT modify the publicly exposed APIs on the Android 1061platform by changing any method or class signatures, or by removing classes or 1062class fields.</li> 1063 <li>Device implementers MAY modify the underlying implementation of the APIs, but 1064such modifications MUST NOT impact the stated behavior and Java-language 1065signature of any publicly exposed APIs.</li> 1066 <li>Device implementers MUST NOT add any publicly exposed elements (such as classes 1067or interfaces, or fields or methods to existing classes or interfaces) to the 1068APIs above.</li> 1069</ul> 1070 1071<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, 1072device implementers MUST NOT expose new APIs or alter existing APIs in the 1073namespaces noted above. Device implementers MAY make internal-only 1074modifications, but those modifications MUST NOT be advertised or otherwise 1075exposed to developers.</p> 1076 1077<p>Device implementers MAY add custom APIs, but any such APIs MUST NOT be in a 1078namespace owned by or referring to another organization. For instance, device 1079implementers MUST NOT add APIs to the com.google.* or similar namespace: only 1080Google may do so. Similarly, Google MUST NOT add APIs to other companies' 1081namespaces. Additionally, if a device implementation includes custom APIs 1082outside the standard Android namespace, those APIs MUST be packaged in an 1083Android shared library so that only apps that explicitly use them (via the 1084lt;uses-librarygt; mechanism) are affected by the increased memory usage of such 1085APIs.</p> 1086 1087<p>If a device implementer proposes to improve one of the package namespaces above 1088(such as by adding useful new functionality to an existing API, or adding a new 1089API), 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 1090information on that site.</p> 1091 1092<p>Note that the restrictions above correspond to standard conventions for naming 1093APIs in the Java programming language; this section simply aims to reinforce 1094those conventions and make them binding through inclusion in this Compatibility 1095Definition.</p> 1096 1097<h2 id="3_7_runtime_compatibility">3.7. Runtime Compatibility</h2> 1098 1099 1100<p>Device implementations MUST support the full Dalvik Executable (DEX) format and 1101Dalvik 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 1102the Dalvik Executable Format, and the reference implementation’s package 1103management system.</p> 1104 1105<p>Device implementations MUST configure Dalvik runtimes to allocate memory in 1106accordance with the upstream Android platform, and as specified by the 1107following table. (See <a href="#7_1_1_screen_configuration">section 7.1.1</a> for screen size and screen density definitions.)</p> 1108 1109<p>Note that memory values specified below are considered minimum values and 1110device implementations MAY allocate more memory per application.</p> 1111 1112<table> 1113 <tr> 1114 <th>Screen Layout</th> 1115 <th>Screen Density</th> 1116 <th>Minimum Application Memory</th> 1117 </tr> 1118 <tr> 1119 <td rowspan="10">small/normal</td> 1120 <td>120 dpi (ldpi)</td> 1121 <td rowspan="2">32MB</td> 1122 </tr> 1123 <tr> 1124 <td>160 dpi (mdpi)</td> 1125 </tr> 1126 <tr> 1127 <td>213 dpi (tvdpi)</td> 1128 <td rowspan="3">48MB</td> 1129 </tr> 1130 <tr> 1131 <td>240 dpi (hdpi)</td> 1132 </tr> 1133 <tr> 1134 <td>280 dpi (280dpi)</td> 1135 </tr> 1136 <tr> 1137 <td>320 dpi (xhdpi)</td> 1138 <td>80MB</td> 1139 </tr> 1140 <tr> 1141 <td>400 dpi (400dpi)</td> 1142 <td>96MB</td> 1143 </tr> 1144 <tr> 1145 <td>480 dpi (xxhdpi)</td> 1146 <td>128MB</td> 1147 </tr> 1148 <tr> 1149 <td>560 dpi (560dpi)</td> 1150 <td>192MB</td> 1151 </tr> 1152 <tr> 1153 <td>640 dpi (xxxhdpi)</td> 1154 <td>256MB</td> 1155 </tr> 1156 <tr> 1157 <td rowspan="10">large</td> 1158 <td>120 dpi (ldpi)</td> 1159 <td>32MB</td> 1160 </tr> 1161 <tr> 1162 <td>160 dpi (mdpi)</td> 1163 <td>48MB</td> 1164 </tr> 1165 <tr> 1166 <td>213 dpi (tvdpi)</td> 1167 <td rowspan="2">80MB</td> 1168 </tr> 1169 <tr> 1170 <td>240 dpi (hdpi)</td> 1171 </tr> 1172 <tr> 1173 <td>280 dpi (280dpi)</td> 1174 <td>96MB</td> 1175 </tr> 1176 <tr> 1177 <td>320 dpi (xhdpi)</td> 1178 <td>128MB</td> 1179 </tr> 1180 <tr> 1181 <td>400 dpi (400dpi)</td> 1182 <td>192MB</td> 1183 </tr> 1184 <tr> 1185 <td>480 dpi (xxhdpi)</td> 1186 <td>256MB</td> 1187 </tr> 1188 <tr> 1189 <td>560 dpi (560dpi)</td> 1190 <td>384MB</td> 1191 </tr> 1192 <tr> 1193 <td>640 dpi (xxxhdpi)</td> 1194 <td>512MB</td> 1195 </tr> 1196 <tr> 1197 <td rowspan="10">xlarge</td> 1198 <td>120 dpi (ldpi)</td> 1199 <td>48MB</td> 1200 </tr> 1201 <tr> 1202 <td>160 dpi (mdpi)</td> 1203 <td>80MB</td> 1204 </tr> 1205 <tr> 1206 <td>213 dpi (tvdpi)</td> 1207 <td rowspan="2">96MB</td> 1208 </tr> 1209 <tr> 1210 <td>240 dpi (hdpi)</td> 1211 </tr> 1212 <tr> 1213 <td>280 dpi (280dpi)</td> 1214 <td>144MB</td> 1215 </tr> 1216 <tr> 1217 <td>320 dpi (xhdpi)</td> 1218 <td>192MB</td> 1219 </tr> 1220 <tr> 1221 <td>400 dpi (400dpi)</td> 1222 <td>288MB</td> 1223 </tr> 1224 <tr> 1225 <td>480 dpi (xxhdpi)</td> 1226 <td>384MB</td> 1227 </tr> 1228 <tr> 1229 <td>560 dpi (560dpi)</td> 1230 <td>576MB</td> 1231 </tr> 1232 <tr> 1233 <td>640 dpi (xxxhdpi)</td> 1234 <td>768MB</td> 1235 </tr> 1236</table> 1237 1238 1239<h2 id="3_8_user_interface_compatibility">3.8. User Interface Compatibility</h2> 1240 1241 1242<h3 id="3_8_1_launcher_home_screen">3.8.1. Launcher (Home Screen)</h3> 1243 1244 1245<p>Android includes a launcher application (home screen) and support for 1246third-party applications to replace the device launcher (home screen). Device 1247implementations that allow third-party applications to replace the device home 1248screen MUST declare the platform feature android.software.home_screen.</p> 1249 1250<h3 id="3_8_2_widgets">3.8.2. Widgets</h3> 1251 1252<div class="note"> 1253<p>Widgets are optional for all Android device implementations, but SHOULD be 1254supported on Android Handheld devices.</p> 1255</div> 1256 1257 1258<p>Android defines a component type and corresponding API and lifecycle that 1259allows 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 1260implementations. Device implementations that support embedding widgets on the 1261home screen MUST meet the following requirements and declare support for 1262platform feature android.software.app_widgets.</p> 1263 1264<ul> 1265 <li>Device launchers MUST include built-in support for AppWidgets, and expose user 1266interface affordances to add, configure, view, and remove AppWidgets directly 1267within the Launcher.</li> 1268 <li>Device implementations MUST be capable of rendering widgets that are 4 x 4 in 1269the standard grid size. See the App Widget Design Guidelines in the Android SDK 1270documentation [<a href="http://developer.android.com/guide/practices/ui_guidelines/widget_design.html">Resources, 21</a>] for details.</li> 1271 <li>Device implementations that include support for lock screen MAY support 1272application widgets on the lock screen.</li> 1273</ul> 1274 1275<h3 id="3_8_3_notifications">3.8.3. Notifications</h3> 1276 1277 1278<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> 1279 1280<p>Some APIs allow applications to perform notifications or attract attention 1281using hardware—specifically sound, vibration, and light. Device implementations 1282MUST support notifications that use hardware features, as described in the SDK 1283documentation, and to the extent possible with the device implementation 1284hardware. For instance, if a device implementation includes a vibrator, it MUST 1285correctly implement the vibration APIs. If a device implementation lacks 1286hardware, the corresponding APIs MUST be implemented as no-ops. This behavior 1287is further detailed in <a href="#7_hardware_compatibility">section 7</a>.</p> 1288 1289<p>Additionally, the implementation MUST correctly render all resources (icons, animation files 1290etc.) provided for in the APIs 1291[<a href="https://developer.android.com/guide/topics/resources/available-resources.html">Resources, 23</a>], 1292or in the Status/System Bar icon style guide 1293[<a href="http://developer.android.com/design/style/iconography.html">Resources, 24</a>], 1294which in the case of an Android Television device includes the possibility to not display the 1295notifications. Device implementers MAY provide an alternative user experience for 1296notifications than that provided by the reference Android Open Source 1297implementation; however, such alternative notification systems MUST support 1298existing notification resources, as above. </p> 1299 1300<p>Android includes support for various notifications, such as:</p> 1301 1302<ul> 1303 <li><strong>Rich notifications</strong>. Interactive Views for ongoing notifications.</li> 1304 <li><strong>Heads-up notifications</strong>. Interactive Views users can act on or dismiss without leaving the current app.</li> 1305 <li><strong>Lockscreen notifications</strong>. Notifications shown over a lock screen with granular control on visibility.</li> 1306</ul> 1307 1308<p>Android device implementations, when such notifications are made visible, MUST properly execute 1309Rich and Heads-up notifications and include the title/name, icon, text as documented in the Android 1310APIs <a href="https://developer.android.com/design/patterns/notifications.html">[Resources, 25]</a>. 1311</p> 1312 1313<p>Android includes Notification Listener Service APIs that allow apps (once 1314explicitly enabled by the user) to receive a copy of all notifications as they 1315are posted or updated. Device implementations MUST correctly and promptly send 1316notifications in their entirety to all such installed and user-enabled listener 1317services, including any and all metadata attached to the Notification object.</p> 1318 1319<h3 id="3_8_4_search">3.8.4. Search</h3> 1320 1321 1322<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 1323expose their application’s data into the global system search. Generally 1324speaking, this functionality consists of a single, system-wide user interface 1325that allows users to enter queries, displays suggestions as users type, and 1326displays results. The Android APIs allow developers to reuse this interface to 1327provide search within their own apps, and allow developers to supply results to 1328the common global search user interface.</p> 1329 1330<p>Android device implementations SHOULD include global search, a single, shared, 1331system-wide search user interface capable of real-time suggestions in response 1332to user input. Device implementations SHOULD implement the APIs that allow 1333developers to reuse this user interface to provide search within their own 1334applications. Device implementations that implement the global search interface 1335MUST implement the APIs that allow third-party applications to add suggestions 1336to the search box when it is run in global search mode. If no third-party 1337applications are installed that make use of this functionality, the default 1338behavior SHOULD be to display web search engine results and suggestions.</p> 1339 1340<h3 id="3_8_5_toasts">3.8.5. Toasts</h3> 1341 1342 1343<p>Applications can use the “Toast” API to display short non-modal strings to the 1344end 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 1345some high-visibility manner.</p> 1346 1347<h3 id="3_8_6_themes">3.8.6. Themes</h3> 1348 1349 1350<p>Android provides “themes” as a mechanism for applications to apply styles 1351across an entire Activity or application.</p> 1352 1353<p>Android includes a “Holo” theme family as a set of defined styles for 1354application developers to use if they want to match the Holo theme look and 1355feel 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 1356exposed to applications [<a href="http://developer.android.com/reference/android/R.style.html">Resources, 29</a>].</p> 1357 1358<p>Android includes a “Material” theme family as a set of defined styles for 1359application developers to use if they want to match the design theme’s look and 1360feel across the wide variety of different Android device types. Device 1361implementations MUST support the “Material” theme family and MUST NOT alter any 1362of 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> 1363 1364<p>Android also includes a “Device Default” theme family as a set of defined 1365styles for application developers to use if they want to match the look and 1366feel of the device theme as defined by the device implementer. Device 1367implementations MAY modify the Device Default theme attributes exposed to 1368applications [<a href="http://developer.android.com/reference/android/R.style.html">Resources, 29</a>].</p> 1369 1370<p>Android supports a new variant theme with translucent system bars, which allows 1371application developers to fill the area behind the status and navigation bar 1372with their app content. To enable a consistent developer experience in this 1373configuration, it is important the status bar icon style is maintained across 1374different device implementations. Therefore, Android device implementations 1375MUST use white for system status icons (such as signal strength and battery 1376level) and notifications issued by the system, unless the icon is indicating a 1377problematic status [<a href="http://developer.android.com/reference/android/R.style.html">Resources, 29</a>].</p> 1378 1379<h3 id="3_8_7_live_wallpapers">3.8.7. Live Wallpapers</h3> 1380 1381 1382<p>Android defines a component type and corresponding API and lifecycle that 1383allows 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 1384input capabilities that display as a wallpaper, behind other applications.</p> 1385 1386<p>Hardware is considered capable of reliably running live wallpapers if it can 1387run all live wallpapers, with no limitations on functionality, at a reasonable 1388frame rate with no adverse effects on other applications. If limitations in the 1389hardware cause wallpapers and/or applications to crash, malfunction, consume 1390excessive CPU or battery power, or run at unacceptably low frame rates, the 1391hardware is considered incapable of running live wallpaper. As an example, some 1392live wallpapers may use an OpenGL 2.0 or 3.x context to render their content. 1393Live wallpaper will not run reliably on hardware that does not support multiple 1394OpenGL contexts because the live wallpaper use of an OpenGL context may 1395conflict with other applications that also use an OpenGL context.</p> 1396 1397<p>Device implementations capable of running live wallpapers reliably as described 1398above SHOULD implement live wallpapers, and when implemented MUST report the 1399platform feature flag android.software.live_wallpaper.</p> 1400 1401<h3 id="3_8_8_activity_switching">3.8.8. Activity Switching</h3> 1402 1403<div class="note"> 1404<p>As the Recent function navigation key is OPTIONAL, the requirements to 1405implement the overview screen is OPTIONAL for Android Television devices and 1406Android Watch devices.</p> 1407</div> 1408 1409 1410<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 1411accessed activities and tasks using a thumbnail image of the application’s 1412graphical state at the moment the user last left the application. Device 1413implementations 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> 1414 1415<ul> 1416 <li>MUST display affiliated recents as a group that moves together.</li> 1417 <li>MUST support at least up to 20 displayed activities.</li> 1418 <li>MUST at least display the title of 4 activities at a time.</li> 1419 <li>SHOULD display highlight color, icon, screen title in recents.</li> 1420 <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> 1421 <li>SHOULD display a closing affordance ("x") but MAY delay this until user 1422interacts with screens.</li> 1423</ul> 1424 1425<p>Device implementations are STRONGLY ENCOURAGED to use the upstream Android user 1426interface (or a similar thumbnail-based interface) for the overview screen.</p> 1427 1428<h3 id="3_8_9_input_management">3.8.9. Input Management</h3> 1429 1430 1431<p>Android includes support for Input Management and support for third-party input 1432method 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 1433the device MUST declare the platform feature android.software.input_methods and 1434support IME APIs as defined in the Android SDK documentation.</p> 1435 1436<p>Device implementations that declare the android.software.input_methods feature 1437MUST provide a user-accessible mechanism to add and configure third-party input 1438methods. Device implementations MUST display the settings interface in response 1439to the android.settings.INPUT_METHOD_SETTINGS intent.</p> 1440 1441<h3 id="3_8_10_lock_screen_media_control">3.8.10. Lock Screen Media Control</h3> 1442 1443 1444<p>The Remote Control Client API is deprecated from Android 5.0 in favor of the 1445Media Notification Template that allows media applications to integrate with 1446playback controls that are displayed on the lock screen [<a href="http://developer.android.com/reference/android/app/Notification.MediaStyle.html">Resources, 35</a>]. 1447Device implementations that support a lock screen, unless an Android Automotive or Watch 1448implementation, MUST display the Lockscreen Notifications including the Media Notification 1449Template.</p> 1450 1451<h3 id="3_8_11_dreams">3.8.11. Dreams</h3> 1452 1453 1454<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 1455a power source is idle or docked in a desk dock. Android Watch devices MAY 1456implement Dreams, but other types of device implementations SHOULD include 1457support for Dreams and provide a settings option for users to configure Dreams 1458in response to the android.settings.DREAM_SETTINGS intent.</p> 1459 1460<h3 id="3_8_12_location">3.8.12. Location</h3> 1461 1462 1463<p>When a device has a hardware sensor (e.g. GPS) that is capable of providing the 1464location coordinates, location modes MUST be displayed in the Location menu 1465within Settings [<a href="http://developer.android.com/reference/android/provider/Settings.Secure.html#LOCATION_MODE">Resources, 37</a>].</p> 1466 1467<h3 id="3_8_13_unicode_and_font">3.8.13. Unicode and Font</h3> 1468 1469 1470<p>Android includes support for color emoji characters. When Android device 1471implementations include an IME, devices SHOULD provide an input method to the 1472user 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> 1473 1474<p>Android includes support for Roboto 2 font with different 1475weights—sans-serif-thin, sans-serif-light, sans-serif-medium, sans-serif-black, 1476sans-serif-condensed, sans-serif-condensed-light—which MUST all be included for 1477the languages available on the device and full Unicode 7.0 coverage of Latin, 1478Greek, and Cyrillic, including the Latin Extended A, B, C, and D ranges, and 1479all glyphs in the currency symbols block of Unicode 7.0.</p> 1480 1481<h2 id="3_9_device_administration">3.9. Device Administration</h2> 1482 1483 1484<p>Android includes features that allow security-aware applications to perform 1485device administration functions at the system level, such as enforcing password 1486policies or performing remote wipe, through the Android Device Administration 1487API [<a href="http://developer.android.com/guide/topics/admin/device-admin.html">Resources, 39</a>]. 1488Device implementations MUST provide an implementation of the DevicePolicyManager class 1489[<a href="http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html">Resources, 40</a>]. 1490Device implementations that include support for PIN (numeric) or PASSWORD 1491(alphanumeric) based lock screens MUST support the full range of device 1492administration policies defined in the Android SDK documentation 1493[<a href="http://developer.android.com/guide/topics/admin/device-admin.html">Resources, 39</a>] 1494and report the platform feature android.software.device_admin.</p> 1495 1496<p>Device implementations MAY have a preinstalled application performing device 1497administration functions but this application MUST NOT be set out-of-the box as 1498the default Device Owner app [<a href="http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html#isDeviceOwnerApp(java.lang.String)">Resources, 41</a>].</p> 1499 1500<h2 id="3_10_accessibility">3.10. Accessibility</h2> 1501 1502 1503<p>Android provides an accessibility layer that helps users with disabilities to 1504navigate their devices more easily. In addition, Android provides platform APIs 1505that enable accessibility service implementations to receive callbacks for user 1506and system events and generate alternate feedback mechanisms, such as 1507text-to-speech, haptic feedback, and trackball/d-pad navigation [<a href="http://developer.android.com/reference/android/accessibilityservice/AccessibilityService.html">Resources, 42</a>].</p> 1508 1509<p>Device implementations include the following requirements:</p> 1510 1511<ul> 1512<li>Android Automotive implementations SHOULD provide an implementation of the 1513Android accessibility framework consistent with the default Android 1514implementation.</li> 1515<li>Device implementations (Android Automotive excluded) MUST provide an 1516implementation of the Android accessibility framework consistent with the 1517default Android implementation.</li> 1518<li>Device implementations (Android Automotive excluded) MUST support 1519third-party accessibility service implementations through the 1520android.accessibilityservice APIs 1521[<a href="http://developer.android.com/reference/android/view/accessibility/package-summary.html">Resources, 43</a>]</li> 1522<li>Device implementations (Android Automotive excluded) MUST generate 1523AccessibilityEvents and deliver these events to all registered 1524AccessibilityService implementations in a manner consistent with the default 1525Android implementation</li> 1526<li> Device implementations (Android Automotive and Android Watch devices with 1527no audio output excluded), MUST provide a user-accessible mechanism to enable 1528and disable accessibility services, and MUST display this interface in response 1529to the android.provider.Settings.ACTION_ACCESSIBILITY_SETTINGS intent.</li> 1530</ul> 1531 1532<p>Additionally, device implementations SHOULD provide an implementation of an 1533accessibility service on the device, and SHOULD provide a mechanism for users 1534to enable the accessibility service during device setup. An open source 1535implementation of an accessibility service is available from the Eyes Free 1536project [<a href="http://code.google.com/p/eyes-free/">Resources, 44</a>].</p> 1537 1538<h2 id="3_11_text-to-speech">3.11. Text-to-Speech</h2> 1539 1540 1541<p>Android includes APIs that allow applications to make use of text-to-speech 1542(TTS) services and allows service providers to provide implementations of TTS 1543services [<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 1544MUST meet these requirements related to the Android TTS framework. </p> 1545 1546<p>Android Automotive implementations:</p> 1547<ul> 1548<li>MUST support the Android TTS framework APIs.</li> 1549<li>MAY support installation of third-party TTS engines. If supported, partners 1550MUST provide a user-accessible interface that allows the user to select a TTS 1551engine for use at system level.</li> 1552</ul> 1553 1554<p>All other device implementations:</p> 1555 1556<ul> 1557 <li> MUST support the Android TTS framework APIs and SHOULD include a TTS engine 1558supporting the languages available on the device. Note that the upstream 1559Android open source software includes a full-featured TTS engine 1560implementation. 1561 <li> MUST support installation of third-party TTS engines 1562 <li> MUST provide a user-accessible interface that allows users to select a TTS 1563engine for use at the system level 1564</ul> 1565 1566<h2 id="3_12_tv_input_framework">3.12. TV Input Framework</h2> 1567 1568 1569<p>The Android Television Input Framework (TIF) simplifies the delivery of live 1570content to Android Television devices. TIF provides a standard API to create 1571input modules that control Android Television devices. Android Television 1572device implementations MUST support Television Input Framework [<a href="http://source.android.com/devices/tv/index.html">Resources, 46</a>].</p> 1573 1574<p>Device implementations that support TIF MUST declare the platform feature 1575android.software.live_tv.</p> 1576 1577<h1 id="4_application_packaging_compatibility">4. Application Packaging Compatibility</h1> 1578 1579 1580<p>Device implementations MUST install and run Android “.apk” files as generated 1581by the “aapt” tool included in the official Android SDK [<a href="http://developer.android.com/tools/help/index.html">Resources, 47</a>].</p> 1582 1583<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 1584files from installing and running correctly on other compatible devices.</p> 1585 1586<h1 id="5_multimedia_compatibility">5. Multimedia Compatibility</h1> 1587 1588 1589<h2 id="5_1_media_codecs">5.1. Media Codecs</h2> 1590 1591 1592<p>Device implementations MUST support the core media formats specified in the 1593Android 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 1594implementations MUST support the media formats, encoders, decoders, file types, 1595and container formats defined in the tables below and reported via MediaCodecList 1596[<a href="http://developer.android.com/reference/android/media/MediaCodecList.html">Resources,112</a>]. 1597Device implementations MUST also be able to decode all profiles reported in its CamcorderProfile 1598[<a href="http://developer.android.com/reference/android/media/CamcorderProfile.html">Resources, 1599113</a>]. 1600 1601All of these codecs are 1602provided as software implementations in the preferred Android implementation 1603from the Android Open Source Project.</p> 1604 1605<p>Please note that neither Google nor the Open Handset Alliance make any 1606representation that these codecs are free from third-party patents. Those 1607intending to use this source code in hardware or software products are advised 1608that implementations of this code, including in open source software or 1609shareware, may require patent licenses from the relevant patent holders.</p> 1610 1611<h3 id="5_1_1_audio_codecs">5.1.1. Audio Codecs</h3> 1612 1613<table> 1614 <tr> 1615 <th>Format/Codec</th> 1616 <th>Encoder</th> 1617 <th>Decoder</th> 1618 <th>Details</th> 1619 <th>Supported File Types/Container Formats</th> 1620 </tr> 1621 <tr> 1622 <td>MPEG-4 AAC Profile</p> 1623 1624<p>(AAC LC)</td> 1625 <td>REQUIRED<sup>1</sup></td> 1626 <td>REQUIRED</td> 1627 <td>Support for mono/stereo/5.0/5.1<sup>2</sup> content with standard sampling rates from 8 to 162848 kHz.</td> 1629 <td> 1630 <ul> 1631 <li class="table_list">3GPP (.3gp)</li> 1632 <li class="table_list">MPEG-4 (.mp4, .m4a)</li> 1633 <li class="table_list">ADTS raw AAC (.aac, decode in Android 3.1+, encode in Android 4.0+, ADIF not 1634supported)</li> 1635 <li class="table_list">MPEG-TS (.ts, not seekable, Android 3.0+)</li></ul></td> 1636 </tr> 1637 <tr> 1638 <td>MPEG-4 HE AAC Profile (AAC+)</td> 1639 <td>REQUIRED<sup>1</sup><br>(Android 4.1+)</td> 1640 <td>REQUIRED</td> 1641 <td>Support for mono/stereo/5.0/5.1<sup>2</sup> content with standard sampling rates from 16 1642to 48 kHz.</td> 1643 <td></td> 1644 </tr> 1645 <tr> 1646 <td>MPEG-4 HE AACv2</p> 1647 1648<p>Profile (enhanced AAC+)</td> 1649 <td> </td> 1650 <td>REQUIRED</td> 1651 <td>Support for mono/stereo/5.0/5.1<sup>2</sup> content with standard sampling rates from 16 1652to 48 kHz.</td> 1653 <td></td> 1654 </tr> 1655 <tr> 1656 <td>AAC ELD (enhanced low delay AAC)</td> 1657 <td>REQUIRED<sup>1</sup> </p> 1658 1659<p>(Android 4.1+)</td> 1660 <td>REQUIRED</p> 1661 1662<p>(Android 4.1+)</td> 1663 <td>Support for mono/stereo content with standard sampling rates from 16 to 48 kHz.</td> 1664 <td></td> 1665 </tr> 1666 <tr> 1667 <td>AMR-NB</td> 1668 <td>REQUIRED<sup>3</sup></td> 1669 <td>REQUIRED<sup>3</sup></td> 1670 <td>4.75 to 12.2 kbps sampled @ 8kHz</td> 1671 <td>3GPP (.3gp)</td> 1672 </tr> 1673 <tr> 1674 <td>AMR-WB</td> 1675 <td>REQUIRED<sup>3</sup></td> 1676 <td>REQUIRED<sup>3</sup></td> 1677 <td>9 rates from 6.60 kbit/s to 23.85 kbit/s sampled @ 16kHz</td> 1678 <td></td> 1679 </tr> 1680 <tr> 1681 <td>FLAC</td> 1682 <td></td> 1683 <td>REQUIRED <br>(Android 3.1+)</td> 1684 <td>Mono/Stereo (no multichannel). Sample rates up to 48 kHz (but up to 44.1 kHz is 1685recommended on devices with 44.1 kHz output, as the 48 to 44.1 kHz downsampler 1686does not include a low-pass filter). 16-bit recommended; no dither applied for 168724-bit.</td> 1688 <td>FLAC (.flac) only</td> 1689 </tr> 1690 <tr> 1691 <td>MP3</td> 1692 <td></td> 1693 <td>REQUIRED</td> 1694 <td>Mono/Stereo 8-320Kbps constant (CBR) or variable bitrate (VBR)</td> 1695 <td>MP3 (.mp3)</td> 1696 </tr> 1697 <tr> 1698 <td>MIDI</td> 1699 <td></td> 1700 <td>REQUIRED</td> 1701 <td>MIDI Type 0 and 1. DLS Version 1 and 2. XMF and Mobile XMF. Support for 1702ringtone formats RTTTL/RTX, OTA, and iMelody</td> 1703 <td><ul> 1704 <li class="table_list">Type 0 and 1 (.mid, .xmf, .mxmf)</li> 1705 <li class="table_list">RTTTL/RTX (.rtttl, .rtx)</li> 1706 <li class="table_list">OTA (.ota)</li> 1707 <li class="table_list">iMelody (.imy)</li></ul></td> 1708 </tr> 1709 <tr> 1710 <td>Vorbis</td> 1711 <td></td> 1712 <td>REQUIRED</td> 1713 <td></td> 1714 <td><ul> 1715 <li class="table_list">Ogg (.ogg)</li> 1716 <li class="table_list">Matroska (.mkv, Android 4.0+)</li></ul></td> 1717 </tr> 1718 <tr> 1719 <td>PCM/WAVE</td> 1720 <td>REQUIRED<sup>4</sup><br> (Android 4.1+)</td> 1721 <td>REQUIRED</td> 1722 <td>16-bit linear PCM (rates up to limit of hardware). Devices MUST support 1723sampling rates for raw PCM recording at 8000, 11025, 16000, and 44100 Hz 1724frequencies.</td> 1725 <td>WAVE (.wav)</td> 1726 </tr> 1727 <tr> 1728 <td>Opus</td> 1729 <td></td> 1730 <td>REQUIRED<br> (Android 5.0+)</td> 1731 <td></td> 1732 <td>Matroska (.mkv)</td> 1733 </tr> 1734</table> 1735 1736 1737<p class="table_footnote"> 1 Required for device implementations that define android.hardware.microphone 1738but optional for Android Watch device implementations.</p> 1739 1740<p class="table_footnote">2 Only downmix of 5.0/5.1 content is required; recording or rendering more than 17412 channels is optional.</p> 1742 1743<p class="table_footnote">3 Required for Android Handheld device implementations. </p> 1744 1745<p class="table_footnote">4 Required for device implementations that define android.hardware.microphone, 1746including Android Watch device implementations.</p> 1747 1748<h3 id="5_1_2_image_codecs">5.1.2. Image Codecs</h3> 1749 1750<table> 1751 <tr> 1752 <th>Format/Codec</th> 1753 <th>Encoder</th> 1754 <th>Decoder</th> 1755 <th>Details</th> 1756 <th>Supported File Types/Container Formats</th> 1757 </tr> 1758 <tr> 1759 <td>JPEG</td> 1760 <td>REQUIRED</td> 1761 <td>REQUIRED</td> 1762 <td>Base+progressive</td> 1763 <td>JPEG (.jpg)</td> 1764 </tr> 1765 <tr> 1766 <td>GIF</td> 1767 <td></td> 1768 <td>REQUIRED</td> 1769 <td></td> 1770 <td>GIF (.gif)</td> 1771 </tr> 1772 <tr> 1773 <td>PNG</td> 1774 <td>REQUIRED</td> 1775 <td>REQUIRED</td> 1776 <td></td> 1777 <td>PNG (.png)</td> 1778 </tr> 1779 <tr> 1780 <td>BMP</td> 1781 <td></td> 1782 <td>REQUIRED</td> 1783 <td></td> 1784 <td>BMP (.bmp)</td> 1785 </tr> 1786 <tr> 1787 <td>WebP</td> 1788 <td>REQUIRED</td> 1789 <td>REQUIRED</td> 1790 <td></td> 1791 <td>WebP (.webp)</td> 1792 </tr> 1793</table> 1794 1795 1796<h3 id="5_1_3_video_codecs">5.1.3. Video Codecs</h3> 1797 1798<p>Video codecs are optional for Android Watch device implementations.</p> 1799 1800<table> 1801 <tr> 1802 <th>Format/Codec</th> 1803 <th>Encoder</th> 1804 <th>Decoder</th> 1805 <th>Details</th> 1806 <th>Supported File Types/<br>Container Formats</th> 1807 </tr> 1808 <tr> 1809 <td>H.263</td> 1810 <td>REQUIRED<sup>1</sup></td> 1811 <td>REQUIRED<sup>2</sup></td> 1812 <td></td> 1813 <td><ul> 1814 <li class="table_list">3GPP (.3gp)</li> 1815 <li class="table_list">MPEG-4 (.mp4)</li></ul></td> 1816 </tr> 1817 <tr> 1818 <td>H.264 AVC</td> 1819 <td>REQUIRED<sup>2</sup></td> 1820 <td>REQUIRED<sup>2</sup></td> 1821 <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> 1822 <td><ul> 1823 <li class="table_list">3GPP (.3gp)</li> 1824 <li class="table_list">MPEG-4 (.mp4)</li> 1825 <li class="table_list">MPEG-TS (.ts, AAC audio only, not seekable, Android 3.0+)</li></ul></td> 1826 </tr> 1827 <tr> 1828 <td>H.265 HEVC</td> 1829 <td></td> 1830 <td>REQUIRED<sup>5</sup></td> 1831 <td>See <a href="#5_3_video_decoding">section 5.3</a> for details</td> 1832 <td>MPEG-4 (.mp4)</td> 1833 </tr> 1834 <tr> 1835 <td>MPEG-4 SP</td> 1836 <td></td> 1837 <td>REQUIRED<sup>2</sup></td> 1838 <td></td> 1839 <td>3GPP (.3gp)</td> 1840 </tr> 1841 <tr> 1842 <td>VP8<sup>3</sup></td> 1843 <td>REQUIRED<sup>2</sup></p> 1844 1845<p>(Android 4.3+)</td> 1846 <td>REQUIRED<sup>2</sup></p> 1847 1848<p>(Android 2.3.3+)</td> 1849 <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> 1850 <td><ul> 1851 <li class="table_list">WebM (.webm) [<a href="http://www.webmproject.org/">Resources, 110</a></li> 1852 <li class="table_list">Matroska (.mkv, Android 4.0+)<sup>4</sup></li></ul></td> 1853 </tr> 1854 <tr> 1855 <td>VP9</td> 1856 <td></td> 1857 <td>REQUIRED<sup>2</sup><br> (Android 4.4+)</td> 1858 <td>See <a href="#5_3_video_decoding">section 5.3</a> for details</td> 1859 <td><ul> 1860 <li class="table_list">WebM (.webm) [<a href="http://www.webmproject.org/">Resources, 110</a>]</li> 1861 <li class="table_list">Matroska (.mkv, Android 4.0+)<sup>4</sup></li></ul></td> 1862 </tr> 1863</table> 1864 1865 1866<p class="table_footnote">1 Required for device implementations that include camera hardware and define 1867android.hardware.camera or android.hardware.camera.front.</p> 1868 1869<p class="table_footnote">2 Required for device implementations except Android Watch devices. </p> 1870 1871<p class="table_footnote">3 For acceptable quality of web video streaming and video-conference services, 1872device implementations SHOULD use a hardware VP8 codec that meets the 1873requirements in [<a href="http://www.webmproject.org/hardware/rtc-coding-requirements/">Resources, 51</a>].</p> 1874 1875<p class="table_footnote">4 Device implementations SHOULD support writing Matroska WebM files.</p> 1876 1877<p class="table_footnote">5 Strongly recommended for Android Automotive, optional for Android Watch, and required for all other device types.</p> 1878 1879<h2 id="5_2_video_encoding">5.2. Video Encoding</h2> 1880 1881<div class="note"> 1882<p>Video codecs are optional for Android Watch device implementations.</p> 1883</div> 1884 1885 1886<p>Android device implementations with H.264 codec support, MUST support Baseline 1887Profile Level 3 and the following SD (Standard Definition) video encoding 1888profiles and SHOULD support Main Profile Level 4 and the following HD (High 1889Definition) video encoding profiles. Android Television devices are STRONGLY 1890RECOMMENDED to encode HD 1080p video at 30 fps.</p> 1891<table> 1892 <tr> 1893 <th></th> 1894 <th>SD (Low quality)</th> 1895 <th>SD (High quality)</th> 1896 <th>HD 720p1</th> 1897 <th>HD 1080p1</th> 1898 </tr> 1899 <tr> 1900 <th>Video resolution</th> 1901 <td>320 x 240 px</td> 1902 <td>720 x 480 px</td> 1903 <td>1280 x 720 px</td> 1904 <td>1920 x 1080 px</td> 1905 </tr> 1906 <tr> 1907 <th>Video frame rate</th> 1908 <td>20 fps</td> 1909 <td>30 fps</td> 1910 <td>30 fps</td> 1911 <td>30 fps</td> 1912 </tr> 1913 <tr> 1914 <th>Video bitrate</th> 1915 <td>384 Kbps</td> 1916 <td>2 Mbps</td> 1917 <td>4 Mbps</td> 1918 <td>10 Mbps</td> 1919 </tr> 1920</table> 1921 1922 1923<p class="table_footnote">1 When supported by hardware, but STRONGLY RECOMMENDED for Android Television 1924devices.</p> 1925 1926<p>Android device implementations with VP8 codec support MUST support the SD video 1927encoding profiles and SHOULD support the following HD (High Definition) video 1928encoding profiles.</p> 1929<table> 1930 <tr> 1931 <th></th> 1932 <th>SD (Low quality)</th> 1933 <th>SD (High quality)</th> 1934 <th>HD 720p1</th> 1935 <th>HD 1080p1</th> 1936 </tr> 1937 <tr> 1938 <th>Video resolution</th> 1939 <td>320 x 180 px</td> 1940 <td>640 x 360 px</td> 1941 <td>1280 x 720 px</td> 1942 <td>1920 x 1080 px</td> 1943 </tr> 1944 <tr> 1945 <th>Video frame rate</th> 1946 <td>30 fps</td> 1947 <td>30 fps</td> 1948 <td>30 fps</td> 1949 <td>30 fps</td> 1950 </tr> 1951 <tr> 1952 <th>Video bitrate</th> 1953 <td>800 Kbps </td> 1954 <td>2 Mbps</td> 1955 <td>4 Mbps</td> 1956 <td>10 Mbps</td> 1957 </tr> 1958</table> 1959 1960<p class="table_footnote">1 When supported by hardware.</p> 1961 1962<h2 id="5_3_video_decoding">5.3. Video Decoding</h2> 1963 1964<div class="note"> 1965<p>Video codecs are optional for Android Watch device implementations.</p> 1966</div> 1967 1968 1969<p>Device implementations MUST support dynamic video resolution switching within 1970the same stream for all VP8, VP9, H.264, and H.265 codecs exposed through the 1971standard Android APIs.</p> 1972 1973<p>Android device implementations with H.264 decoders, MUST support Baseline 1974Profile Level 3 and the following SD video decoding profiles and SHOULD support 1975the HD decoding profiles. Android Television devices MUST support High Profile 1976Level 4.2 and the HD 1080p decoding profile.</p> 1977<table> 1978 <tr> 1979 <th></th> 1980 <th>SD (Low quality)</th> 1981 <th>SD (High quality)</th> 1982 <th>HD 720p1</th> 1983 <th>HD 1080p1</th> 1984 </tr> 1985 <tr> 1986 <th>Video resolution</th> 1987 <td>320 x 240 px</td> 1988 <td>720 x 480 px</td> 1989 <td>1280 x 720 px</td> 1990 <td>1920 x 1080 px</td> 1991 </tr> 1992 <tr> 1993 <th>Video frame rate</th> 1994 <td>30 fps</td> 1995 <td>30 fps</td> 1996 <td>30 fps / 60 fps2</td> 1997 <td>30 fps / 60 fps2</td> 1998 </tr> 1999 <tr> 2000 <th>Video bitrate</th> 2001 <td>800 Kbps </td> 2002 <td>2 Mbps</td> 2003 <td>8 Mbps</td> 2004 <td>20 Mbps</td> 2005 </tr> 2006</table> 2007 2008 2009<p class="table_footnote">1 Required for Android Television device implementations, but for other device 2010types only when supported by hardware.</p> 2011 2012<p class="table_footnote">2 Required for Android Television device implementations.</p> 2013 2014<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 2015decoding profiles. Android Television devices MUST support the HD 1080p 2016decoding profile. </p> 2017<table> 2018 <tr> 2019 <th></th> 2020 <th>SD (Low quality)</th> 2021 <th>SD (High quality)</th> 2022 <th>HD 720p1</th> 2023 <th>HD 1080p1</th> 2024 </tr> 2025 <tr> 2026 <th>Video resolution</th> 2027 <td>320 x 180 px</td> 2028 <td>640 x 360 px</td> 2029 <td>1280 x 720 px</td> 2030 <td>1920 x 1080 px</td> 2031 </tr> 2032 <tr> 2033 <th>Video frame rate</th> 2034 <td>30 fps</td> 2035 <td>30 fps</td> 2036 <td>30 fps / 60 fps2</td> 2037 <td>30 / 60 fps2</td> 2038 </tr> 2039 <tr> 2040 <th>Video bitrate</th> 2041 <td>800 Kbps </td> 2042 <td>2 Mbps</td> 2043 <td>8 Mbps</td> 2044 <td>20 Mbps</td> 2045 </tr> 2046</table> 2047 2048 2049<p class="table_footnote">1 Required for Android Television device implementations, but for other type of 2050devices only when supported by hardware.</p> 2051 2052<p class="table_footnote">2 Required for Android Television device implementations.</p> 2053 2054<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 2055HD decoding profiles. Android Television devices are STRONGLY RECOMMENDED to 2056support the HD 1080p decoding profile and SHOULD support the UHD decoding 2057profile. When the UHD video decoding profile is supported, it MUST support 8 2058bit color depth.</p> 2059<table> 2060 <tr> 2061 <th></th> 2062 <th>SD (Low quality)</th> 2063 <th>SD (High quality)</th> 2064 <th>HD 720p 1</th> 2065 <th>HD 1080p 2</th> 2066 <th>UHD 2</th> 2067 </tr> 2068 <tr> 2069 <th>Video resolution</th> 2070 <td>320 x 180 px</td> 2071 <td>640 x 360 px</td> 2072 <td>1280 x 720 px</td> 2073 <td>1920 x 1080 px</td> 2074 <td>3840 x 2160 px</td> 2075 </tr> 2076 <tr> 2077 <th>Video frame rate</th> 2078 <td>30 fps</td> 2079 <td>30 fps</td> 2080 <td>30 fps</td> 2081 <td>30 fps</td> 2082 <td>30 fps</td> 2083 </tr> 2084 <tr> 2085 <th>Video bitrate</th> 2086 <td>600 Kbps </td> 2087 <td>1.6 Mbps</td> 2088 <td>4 Mbps</td> 2089 <td>10 Mbps</td> 2090 <td>20 Mbps</td> 2091 </tr> 2092</table> 2093 2094 2095<p class="table_footnote">1 Required for Android Television device implementations, but for other type of 2096devices only when supported by hardware.</p> 2097 2098<p class="table_footnote">2 STRONGLY RECOMMENDED for Android Television device implementations when 2099supported by hardware.</p> 2100 2101<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 2102decoding profiles and SHOULD support the HD decoding profiles. Android 2103Television devices MUST support the Main Profile Level 4.1 Main tier and the HD 21041080p decoding profile and SHOULD support Main10 Level 5 Main Tier profile and 2105the UHD decoding profile.</p> 2106<table> 2107 <tr> 2108 <th></th> 2109 <th>SD (Low quality)</th> 2110 <th>SD (High quality)</th> 2111 <th>HD 720p </strong>1 </td> 2112 <th>HD 1080p </strong>1 </td> 2113 <th>UHD </strong>2</td> 2114 </tr> 2115 <tr> 2116 <th>Video resolution</th> 2117 <td>352 x 288 px</td> 2118 <td>640 x 360 px</td> 2119 <td>1280 x 720 px</td> 2120 <td>1920 x 1080 px</td> 2121 <td>3840 x 2160 px</td> 2122 </tr> 2123 <tr> 2124 <th>Video frame rate</th> 2125 <td>30 fps</td> 2126 <td>30 fps</td> 2127 <td>30 fps</td> 2128 <td>30 fps</td> 2129 <td>30 fps</td> 2130 </tr> 2131 <tr> 2132 <th>Video bitrate</th> 2133 <td>600 Kbps </td> 2134 <td>1.6 Mbps</td> 2135 <td>4 Mbps</td> 2136 <td>10 Mbps</td> 2137 <td>20 Mbps</td> 2138 </tr> 2139</table> 2140 2141 2142<p class="table_footnote">1 Required for Android Television device implementation, but for other type of 2143devices only when supported by hardware.</p> 2144 2145<p class="table_footnote">2 Required for Android Television device implementations when supported by 2146hardware.</p> 2147 2148<h2 id="5_4_audio_recording">5.4. Audio Recording</h2> 2149 2150 2151<p>While some of the requirements outlined in this section are stated as SHOULD 2152since Android 4.3, the Compatibility Definition for a future version is planned 2153to 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 2154compatibility when upgraded to the future version.</p> 2155 2156<h3 id="5_4_1_raw_audio_capture">5.4.1. Raw Audio Capture</h3> 2157 2158 2159<p>Device implementations that declare android.hardware.microphone MUST allow 2160capture of raw audio content with the following characteristics:</p> 2161 2162<ul> 2163 <li><strong>Format</strong>: Linear PCM, 16-bit 2164 <li><strong>Sampling rates</strong>: 8000, 11025, 16000, 44100 2165 <li><strong>Channels</strong>: Mono 2166</ul> 2167 2168<p>Device implementations that declare android.hardware.microphone SHOULD allow 2169capture of raw audio content with the following characteristics:</p> 2170 2171<ul> 2172 <li><strong>Format</strong>: Linear PCM, 16-bit 2173 <li><strong>Sampling rates</strong>: 22050, 48000 2174 <li><strong>Channels</strong>: Stereo 2175</ul> 2176 2177<h3 id="5_4_2_capture_for_voice_recognition">5.4.2. Capture for Voice Recognition</h3> 2178 2179 2180<p>In addition to the above recording specifications, when an application has 2181started recording an audio stream using the 2182android.media.MediaRecorder.AudioSource.VOICE_RECOGNITION audio source:</p> 2183 2184<ul> 2185 <li>The device SHOULD exhibit approximately flat amplitude versus frequency 2186characteristics: specifically, ±3 dB, from 100 Hz to 4000 Hz. 2187 <li>Audio input sensitivity SHOULD be set such that a 90 dB sound power level (SPL) 2188source at 1000 Hz yields RMS of 2500 for 16-bit samples. 2189 <li>PCM amplitude levels SHOULD linearly track input SPL changes over at least a 30 2190dB range from -18 dB to +12 dB re 90 dB SPL at the microphone. 2191 <li>Total harmonic distortion SHOULD be less than 1% for 1Khz at 90 dB SPL input 2192level at the microphone. 2193 <li>Noise reduction processing, if present, MUST be disabled. 2194 <li>Automatic gain control, if present, MUST be disabled 2195</ul> 2196 2197<p>If the platform supports noise suppression technologies tuned for speech 2198recognition, the effect MUST be controllable from the 2199android.media.audiofx.NoiseSuppressor API. Moreover, the UUID field for the 2200noise suppressor’s effect descriptor MUST uniquely identify each implementation 2201of the noise suppression technology.</p> 2202 2203<h3 id="5_4_3_capture_for_rerouting_of_playback">5.4.3. Capture for Rerouting of Playback</h3> 2204 2205 2206<p>The android.media.MediaRecorder.AudioSource class includes the REMOTE_SUBMIX 2207audio source. Devices that declare android.hardware.audio.output MUST properly 2208implement the REMOTE_SUBMIX audio source so that when an application uses the 2209android.media.AudioRecord API to record from this audio source, it can capture 2210a mix of all audio streams except for the following:</p> 2211 2212<ul> 2213 <li>STREAM_RING 2214 <li>STREAM_ALARM 2215 <li>STREAM_NOTIFICATION 2216</ul> 2217 2218<h2 id="5_5_audio_playback">5.5. Audio Playback</h2> 2219 2220 2221<p>Device implementations that declare android.hardware.audio.output MUST conform 2222to the requirements in this section.</p> 2223 2224<h3 id="5_5_1_raw_audio_playback">5.5.1. Raw Audio Playback</h3> 2225 2226 2227<p>The device MUST allow playback of raw audio content with the following 2228characteristics:</p> 2229 2230<ul> 2231 <li><strong>Format</strong>: Linear PCM, 16-bit</li> 2232 <li><strong>Sampling rates</strong>: 8000, 11025, 16000, 22050, 32000, 44100</li> 2233 <li><strong>Channels</strong>: Mono, Stereo</li> 2234</ul> 2235 2236<p>The device SHOULD allow playback of raw audio content with the following 2237characteristics:</p> 2238 2239<ul> 2240 <li><strong>Sampling rates</strong>: 24000, 48000</li> 2241</ul> 2242 2243<h3 id="5_5_2_audio_effects">5.5.2. Audio Effects</h3> 2244 2245 2246<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 2247android.hardware.audio.output:</p> 2248 2249<ul> 2250 <li>MUST support the EFFECT_TYPE_EQUALIZER and EFFECT_TYPE_LOUDNESS_ENHANCER 2251implementations controllable through the AudioEffect subclasses Equalizer, 2252LoudnessEnhancer.</li> 2253 <li>MUST support the visualizer API implementation, controllable through the 2254Visualizer class.</li> 2255 <li>SHOULD support the EFFECT_TYPE_BASS_BOOST, EFFECT_TYPE_ENV_REVERB, 2256EFFECT_TYPE_PRESET_REVERB, and EFFECT_TYPE_VIRTUALIZER implementations 2257controllable through the AudioEffect sub-classes BassBoost, 2258EnvironmentalReverb, PresetReverb, and Virtualizer.</li> 2259</ul> 2260 2261<h3 id="5_5_3_audio_output_volume">5.5.3. Audio Output Volume</h3> 2262 2263 2264<p>Android Television device implementations MUST include support for system 2265Master Volume and digital audio output volume attenuation on supported outputs, 2266except for compressed audio passthrough output (where no audio decoding is done 2267on the device).</p> 2268 2269<h2 id="5_6_audio_latency">5.6. Audio Latency</h2> 2270 2271 2272<p>Audio latency is the time delay as an audio signal passes through a system. 2273Many classes of applications rely on short latencies, to achieve real-time 2274sound effects.</p> 2275 2276<p>For the purposes of this section, use the following definitions:</p> 2277 2278<ul> 2279 <li><strong>output latency</strong>. The interval between when an application writes a frame of PCM-coded data and 2280when the corresponding sound can be heard by an external listener or observed 2281by a transducer.</li> 2282 <li><strong>cold output latency</strong>. The output latency for the first frame, when the audio output system has been 2283idle and powered down prior to the request.</li> 2284 <li><strong>continuous output latency</strong>. The output latency for subsequent frames, after the device is playing audio.</li> 2285 <li><strong>input latency</strong>. The interval between when an external sound is presented to the device and 2286when an application reads the corresponding frame of PCM-coded data.</li> 2287 <li><strong>cold input latency</strong>. The sum of lost input time and the input latency for the first frame, when the 2288audio input system has been idle and powered down prior to the request.</li> 2289 <li><strong>continuous input latency</strong>. The input latency for subsequent frames, while the device is capturing audio.</li> 2290 <li><strong>cold output jitter</strong>. The variance among separate measurements of cold output latency values.</li> 2291 <li><strong>cold input jitter</strong>. The variance among separate measurements of cold input latency values.</li> 2292 <li><strong>continuous round-trip latency</strong>. The sum of continuous input latency plus continuous output latency plus 5 2293milliseconds.</li> 2294 <li><strong>OpenSL ES PCM buffer queue API</strong>. The set of PCM-related OpenSL ES APIs within Android NDK; see 2295NDK_root/docs/opensles/index.html.</li> 2296</ul> 2297 2298<p>Device implementations that declare android.hardware.audio.output SHOULD meet 2299or exceed these audio output requirements:</p> 2300 2301<ul> 2302 <li>cold output latency of 100 milliseconds or less</li> 2303 <li>continuous output latency of 45 milliseconds or less</li> 2304 <li>minimize the cold output jitter</li> 2305</ul> 2306 2307<p>If a device implementation meets the requirements of this section after any 2308initial calibration when using the OpenSL ES PCM buffer queue API, for 2309continuous output latency and cold output latency over at least one supported 2310audio output device, it MAY report support for low-latency audio, by reporting 2311the feature android.hardware.audio.low_latency via the 2312android.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 2313MUST NOT report support for low-latency audio.</p> 2314 2315<p>Device implementations that include android.hardware.microphone SHOULD meet 2316these input audio requirements:</p> 2317 2318<ul> 2319 <li>cold input latency of 100 milliseconds or less</li> 2320 <li>continuous input latency of 30 milliseconds or less</li> 2321 <li>continuous round-trip latency of 50 milliseconds or less</li> 2322 <li>minimize the cold input jitter</li> 2323</ul> 2324 2325<h2 id="5_7_network_protocols">5.7. Network Protocols</h2> 2326 2327 2328<p>Devices MUST support the media network protocols for audio and video playback 2329as 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> 2330 2331<ul> 2332 <li>RTSP (RTP, SDP)</li> 2333 <li>HTTP(S) progressive streaming</li> 2334 <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> 2335</ul> 2336 2337<h2 id="5_8_secure_media">5.8. Secure Media</h2> 2338 2339 2340<p>Device implementations that support secure video output and are capable of 2341supporting secure surfaces MUST declare support for Display.FLAG_SECURE. Device 2342implementations that declare support for Display.FLAG_SECURE, if they support a 2343wireless display protocol, MUST secure the link with a cryptographically strong 2344mechanism such as HDCP 2.x or higher for Miracast wireless displays. Similarly 2345if they support a wired external display, the device implementations MUST 2346support HDCP 1.2 or higher. Android Television device implementations MUST 2347support HDCP 2.2 for devices supporting 4K resolution and HDCP 1.4 or above for 2348lower resolutions. The upstream Android open source implementation includes 2349support for wireless (Miracast) and wired (HDMI) displays that satisfies this 2350requirement.</p> 2351 2352<h2 id="5_9_midi">5.9. Musical Instrument Digital Interface (MIDI)</h2> 2353 2354<p> 2355If a device implementation supports the inter-app MIDI software transport 2356(virtual MIDI devices), and it supports MIDI over 2357<em>all</em> of the following MIDI-capable hardware transports 2358for which it provides generic non-MIDI connectivity, it MAY report 2359support for feature android.software.midi via the 2360android.content.pm.PackageManager class 2361[<a href="http://developer.android.com/reference/android/content/pm/PackageManager.html">Resources, 53</a>]. 2362</p> 2363 2364<p>The MIDI-capable hardware transports are:</p> 2365<ul> 2366 <li>USB host mode (section 7.7 USB)</li> 2367 <li>USB peripheral mode (section 7.7 USB)</li> 2368</ul> 2369 2370<p> 2371Conversely, if the device implementation provides generic non-MIDI connectivity over a particular 2372MIDI-capable hardware transport listed above, but does not support MIDI over that hardware transport, 2373it MUST NOT report support for feature android.software.midi. 2374</p> 2375 2376<p> 2377MIDI over Bluetooth LE acting in central role (section 7.4.3 Bluetooth) 2378is in trial use status. A device implementation that reports 2379feature android.software.midi, and which provides generic non-MIDI connectivity 2380over Bluetooth LE, SHOULD support MIDI over Bluetooth LE. 2381</p> 2382 2383<h1 id="6_developer_tools_and_options_compatibility">6. Developer Tools and Options Compatibility</h1> 2384 2385<h2 id="6_1_developer_tools">6.1. Developer Tools</h2> 2386 2387<p>Device implementations MUST support the Android Developer Tools provided in the 2388Android SDK. Android compatible devices MUST be compatible with:</p> 2389 2390<ul> 2391 <li><strong>Android Debug Bridge (adb)</strong> [<a href="http://developer.android.com/tools/help/adb.html">Resources, 55</a>]</li> 2392</ul> 2393 2394<p>Device implementations MUST support all adb functions as documented in the 2395Android 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 2396user-accessible mechanism to turn on the Android Debug Bridge. If a device 2397implementation omits USB peripheral mode, it MUST implement the Android Debug 2398Bridge via local-area network (such as Ethernet or 802.11). </p> 2399 2400<p>Android includes support for secure adb. Secure adb enables adb on known 2401authenticated hosts. Device implementations MUST support secure adb.</p> 2402 2403<ul> 2404 <li><strong>Dalvik Debug Monitor Service (ddms)</strong> [<a href="http://developer.android.com/tools/debugging/ddms.html">Resources, 57</a>]</li> 2405</ul> 2406 2407<p>Device implementations MUST support all ddms features as documented in the 2408Android SDK. As ddms uses adb, support for ddms SHOULD be inactive by default, 2409but MUST be supported whenever the user has activated the Android Debug Bridge, 2410as above.</p> 2411 2412<ul> 2413 <li><strong>Monkey</strong> [<a href="http://developer.android.com/tools/help/monkey.html">Resources, 58</a>]</li> 2414</ul> 2415 2416<p>Device implementations MUST include the Monkey framework, and make it available 2417for applications to use.</p> 2418 2419<ul> 2420 <li><strong>SysTrace</strong> [<a href="http://developer.android.com/tools/help/systrace.html">Resources, 59</a>]</li> 2421</ul> 2422 2423<p>Device implementations MUST support systrace tool as documented in the Android 2424SDK. Systrace must be inactive by default, and there MUST be a user-accessible 2425mechanism to turn on Systrace.</p> 2426 2427<p>Most Linux-based systems and Apple Macintosh systems recognize Android devices 2428using the standard Android SDK tools, without additional support; however 2429Microsoft Windows systems typically require a driver for new Android devices. 2430(For instance, new vendor IDs and sometimes new device IDs require custom USB 2431drivers for Windows systems.) If a device implementation is unrecognized by the 2432adb tool as provided in the standard Android SDK, device implementers MUST 2433provide Windows drivers allowing developers to connect to the device using the 2434adb protocol. These drivers MUST be provided for Windows XP, Windows Vista, 2435Windows 7, Windows 8, and Windows 9 in both 32-bit and 64-bit versions.</p> 2436 2437<h2 id="6_2_developer_options">6.2. Developer Options</h2> 2438 2439 2440<p>Android includes support for developers to configure application 2441development-related settings. Device implementations MUST honor the 2442android.settings.APPLICATION_DEVELOPMENT_SETTINGS intent to show application 2443development-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 2444default and enables users to launch Developer Options after pressing seven (7) 2445times on the <strong>Settings</strong> > <strong>About Device</strong> > <strong>Build Number</strong> menu item. Device implementations MUST provide a consistent experience for 2446Developer Options. Specifically, device implementations MUST hide Developer 2447Options by default and MUST provide a mechanism to enable Developer Options 2448that is consistent with the upstream Android implementation.</p> 2449 2450<h1 id="7_hardware_compatibility">7. Hardware Compatibility</h1> 2451 2452 2453<p>If a device includes a particular hardware component that has a corresponding 2454API for third-party developers, the device implementation MUST implement that 2455API as described in the Android SDK documentation. If an API in the SDK 2456interacts with a hardware component that is stated to be optional and the 2457device implementation does not possess that component:</p> 2458 2459<ul> 2460 <li>Complete class definitions (as documented by the SDK) for the component APIs 2461MUST still be presented. 2462 <li>The API’s behaviors MUST be implemented as no-ops in some reasonable fashion. 2463 <li>API methods MUST return null values where permitted by the SDK documentation. 2464 <li>API methods MUST return no-op implementations of classes where null values are 2465not permitted by the SDK documentation. 2466 <li>API methods MUST NOT throw exceptions not documented by the SDK documentation. 2467</ul> 2468 2469<p>A typical example of a scenario where these requirements apply is the telephony 2470API: even on non-phone devices, these APIs must be implemented as reasonable 2471no-ops.</p> 2472 2473<p>Device implementations MUST consistently report accurate hardware configuration 2474information via the getSystemAvailableFeatures() and hasSystemFeature(String) 2475methods on the android.content.pm.PackageManager class for the same build 2476fingerprint. [<a href="http://developer.android.com/reference/android/content/pm/PackageManager.html">Resources, 53]</a></p> 2477 2478<h2 id="7_1_display_and_graphics">7.1. Display and Graphics</h2> 2479 2480 2481<p>Android includes facilities that automatically adjust application assets and UI 2482layouts appropriately for the device, to ensure that third-party applications 2483run 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 2484this section.</p> 2485 2486<p>The units referenced by the requirements in this section are defined as 2487follows:</p> 2488 2489<ul> 2490 <li><strong>physical diagonal size</strong>. The distance in inches between two opposing corners of the illuminated portion 2491of the display.</li> 2492 <li><strong>dots per inch (dpi)</strong>. The number of pixels encompassed by a linear horizontal or vertical span of 24931”. Where dpi values are listed, both horizontal and vertical dpi must fall 2494within the range.</li> 2495 <li><strong>aspect ratio</strong>. The ratio of the pixels of the longer dimension 2496 to the shorter dimension of the screen. For example, a display of 480x854 pixels 2497 would be 854/480 = 1.779, or roughly “16:9”.</li> 2498 <li><strong>density-independent pixel (dp)</strong> The virtual pixel unit normalized to a 160 dpi screen, calculated as: pixels = 2499dps * (density/160).</li> 2500</ul> 2501 2502<h3 id="7_1_1_screen_configuration">7.1.1. Screen Configuration</h3> 2503 2504 2505<h4 id="7_1_1_1_screen_size">7.1.1.1. Screen Size</h4> 2506 2507<div class="note"> 2508<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> 2509</div> 2510 2511<p>The Android UI framework supports a variety of different screen sizes, and 2512allows applications to query the device screen size (aka “screen layout") via 2513android.content.res.Configuration.screenLayout with the SCREENLAYOUT_SIZE_MASK. 2514Device implementations MUST report the correct screen size as defined in the 2515Android 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 2516implementations MUST report the correct screen size according to the following 2517logical density-independent pixel (dp) screen dimensions.</p> 2518 2519<ul> 2520 <li>Devices MUST have screen sizes of at least 426 dp x 320 dp (‘small’), unless it 2521is an Android Watch device.</li> 2522 <li>Devices that report screen size ‘normal’ MUST have screen sizes of at least 480 2523dp x 320 dp.</li> 2524 <li>Devices that report screen size ‘large’ MUST have screen sizes of at least 640 2525dp x 480 dp.</li> 2526 <li>Devices that report screen size ‘xlarge’ MUST have screen sizes of at least 960 2527dp x 720 dp.</li> 2528</ul> 2529 2530<p>In addition, </p> 2531 2532<ul> 2533 <li>Android Watch devices MUST have a screen with the physical diagonal size in the 2534range from 1.1 to 2.5 inches.</li> 2535 <li>Other types of Android device implementations, with a physically integrated 2536screen, MUST have a screen at least 2.5 inches in physical diagonal size.</li> 2537</ul> 2538 2539<p>Devices MUST NOT change their reported screen size at any time.</p> 2540 2541<p>Applications optionally indicate which screen sizes they support via the 2542<supports-screens> attribute in the AndroidManifest.xml file. Device 2543implementations MUST correctly honor applications' stated support for small, 2544normal, large, and xlarge screens, as described in the Android SDK 2545documentation.</p> 2546 2547<h4 id="7_1_1_2_screen_aspect_ratio">7.1.1.2. Screen Aspect Ratio</h4> 2548 2549<div class="note"> 2550<p>Android Watch devices MAY have an aspect ratio of 1.0 (1:1).</p> 2551</div> 2552 2553 2554<p>The screen aspect ratio MUST be a value from 1.3333 (4:3) to 1.86 (roughly 255516:9), but Android Watch devices MAY have an aspect ratio of 1.0 (1:1) because 2556such a device implementation will use a UI_MODE_TYPE_WATCH as the 2557android.content.res.Configuration.uiMode.</p> 2558 2559<h4 id="7_1_1_3_screen_density">7.1.1.3. Screen Density</h4> 2560 2561 2562<p>The Android UI framework defines a set of standard logical densities to help 2563application developers target application resources. Device implementations 2564MUST report only one of the following logical Android framework densities 2565through the android.util.DisplayMetrics APIs, and MUST execute applications at 2566this standard density and MUST NOT change the value at at any time for the 2567default display.</p> 2568 2569<ul> 2570 <li>120 dpi (ldpi)</li> 2571 <li>160 dpi (mdpi)</li> 2572 <li>213 dpi (tvdpi)</li> 2573 <li>240 dpi (hdpi)</li> 2574 <li>280 dpi (280dpi)</li> 2575 <li>320 dpi (xhdpi)</li> 2576 <li>400 dpi (400dpi)</li> 2577 <li>480 dpi (xxhdpi)</li> 2578 <li>560 dpi (560dpi)</li> 2579 <li>640 dpi (xxxhdpi)</li> 2580</ul> 2581 2582<p>Device implementations SHOULD define the standard Android framework density 2583that is numerically closest to the physical density of the screen, unless that 2584logical density pushes the reported screen size below the minimum supported. If 2585the standard Android framework density that is numerically closest to the 2586physical density results in a screen size that is smaller than the smallest 2587supported compatible screen size (320 dp width), device implementations SHOULD 2588report the next lowest standard Android framework density.</p> 2589 2590<h3 id="7_1_2_display_metrics">7.1.2. Display Metrics</h3> 2591 2592 2593<p>Device implementations MUST report correct values for all display metrics 2594defined 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 2595external screen is used as the default display.</p> 2596 2597<h3 id="7_1_3_screen_orientation">7.1.3. Screen Orientation</h3> 2598 2599 2600<p>Devices MUST report which screen orientations they support 2601(android.hardware.screen.portrait and/or android.hardware.screen.landscape) and 2602MUST report at least one supported orientation. For example, a device with a 2603fixed orientation landscape screen, such as a television or laptop, SHOULD only 2604report android.hardware.screen.landscape.</p> 2605 2606<p>Devices that report both screen orientations MUST support dynamic orientation 2607by applications to either portrait or landscape screen orientation. That is, 2608the device must respect the application’s request for a specific screen 2609orientation. Device implementations MAY select either portrait or landscape 2610orientation as the default.</p> 2611 2612<p>Devices MUST report the correct value for the device’s current orientation, 2613whenever queried via the android.content.res.Configuration.orientation, 2614android.view.Display.getOrientation(), or other APIs.</p> 2615 2616<p>Devices MUST NOT change the reported screen size or density when changing 2617orientation.</p> 2618 2619<h3 id="7_1_4_2d_and_3d_graphics_acceleration">7.1.4. 2D and 3D Graphics Acceleration</h3> 2620 2621 2622<p>Device implementations MUST support both OpenGL ES 1.0 and 2.0, as embodied and 2623detailed in the Android SDK documentations. Device implementations SHOULD 2624support OpenGL ES 3.0 or 3.1 on devices capable of supporting it. Device 2625implementations MUST also support Android RenderScript, as detailed in the 2626Android SDK documentation [<a href="http://developer.android.com/guide/topics/renderscript/">Resources, 63</a>].</p> 2627 2628<p>Device implementations MUST also correctly identify themselves as supporting 2629OpenGL ES 1.0, OpenGL ES 2.0, OpenGL ES 3.0 or OpenGL 3.1. That is:</p> 2630 2631<ul> 2632 <li>The managed APIs (such as via the GLES10.getString() method) MUST report support 2633for OpenGL ES 1.0 and OpenGL ES 2.0.</li> 2634 <li>The native C/C++ OpenGL APIs (APIs available to apps via libGLES_v1CM.so, 2635libGLES_v2.so, or libEGL.so) MUST report support for OpenGL ES 1.0 and OpenGL 2636ES 2.0.</li> 2637 <li>Device implementations that declare support for OpenGL ES 3.0 or 3.1 MUST 2638support the corresponding managed APIs and include support for native C/C++ 2639APIs. On device implementations that declare support for OpenGL ES 3.0 or 3.1, 2640libGLESv2.so MUST export the corresponding function symbols in addition to the 2641OpenGL ES 2.0 function symbols.</li> 2642</ul> 2643 2644<p>In addition to OpenGL ES 3.1, Android provides an extension pack with Java 2645interfaces [<a href="https://developer.android.com/reference/android/opengl/GLES31Ext.html">Resources, 64</a>] and native support for advanced graphics functionality such as tessellation 2646and the ASTC texture compression format. Android device implementations MAY 2647support this extension pack, and—only if fully implemented—MUST identify the 2648support through the android.hardware.opengles.aep feature flag.</p> 2649 2650<p>Also, device implementations MAY implement any desired OpenGL ES extensions. 2651However, device implementations MUST report via the OpenGL ES managed and 2652native APIs all extension strings that they do support, and conversely MUST NOT 2653report extension strings that they do not support.</p> 2654 2655<p>Note that Android includes support for applications to optionally specify that 2656they require specific OpenGL texture compression formats. These formats are 2657typically vendor-specific. Device implementations are not required by Android 2658to implement any specific texture compression format. However, they SHOULD 2659accurately report any texture compression formats that they do support, via the 2660getString() method in the OpenGL API.</p> 2661 2662<p>Android includes a mechanism for applications to declare that they want to 2663enable hardware acceleration for 2D graphics at the Application, Activity, 2664Window, or View level through the use of a manifest tag 2665android:hardwareAccelerated or direct API calls [<a href="http://developer.android.com/guide/topics/graphics/hardware-accel.html">Resources, 65</a>].</p> 2666 2667<p>Device implementations MUST enable hardware acceleration by default, and MUST 2668disable hardware acceleration if the developer so requests by setting 2669android:hardwareAccelerated="false” or disabling hardware acceleration directly 2670through the Android View APIs.</p> 2671 2672<p>In addition, device implementations MUST exhibit behavior consistent with the 2673Android SDK documentation on hardware acceleration [<a href="http://developer.android.com/guide/topics/graphics/hardware-accel.html">Resources, 65</a>].</p> 2674 2675<p>Android includes a TextureView object that lets developers directly integrate 2676hardware-accelerated OpenGL ES textures as rendering targets in a UI hierarchy. 2677Device implementations MUST support the TextureView API, and MUST exhibit 2678consistent behavior with the upstream Android implementation.</p> 2679 2680<p>Android includes support for EGL_ANDROID_RECORDABLE, an EGLConfig attribute 2681that indicates whether the EGLConfig supports rendering to an ANativeWindow 2682that records images to a video. Device implementations MUST support 2683EGL_ANDROID_RECORDABLE extension [<a href="https://www.khronos.org/registry/egl/extensions/ANDROID/EGL_ANDROID_recordable.txt">Resources, 66</a>].</p> 2684 2685<h3 id="7_1_5_legacy_application_compatibility_mode">7.1.5. Legacy Application Compatibility Mode</h3> 2686 2687 2688<p>Android specifies a “compatibility mode” in which the framework operates in a 2689'normal' screen size equivalent (320dp width) mode for the benefit of legacy 2690applications not developed for old versions of Android that pre-date 2691screen-size independence.</p> 2692 2693<ul> 2694<li>Android Automotive does not support legacy compatibility mode.</li> 2695<li>All other device implementations MUST include support for legacy application 2696compatibility mode as implemented by the upstream Android open source code. That 2697is, device implementations MUST NOT alter the triggers or thresholds at which 2698compatibility mode is activated, and MUST NOT alter the behavior of the 2699compatibility mode itself.</li> 2700</ul> 2701 2702<h3 id="7_1_6_screen_technology">7.1.6. Screen Technology</h3> 2703 2704 2705<p>The Android platform includes APIs that allow applications to render rich 2706graphics to the display. Devices MUST support all of these APIs as defined by 2707the Android SDK unless specifically allowed in this document. </p> 2708 2709<ul> 2710 <li>Devices MUST support displays capable of rendering 16-bit color graphics and 2711SHOULD support displays capable of 24-bit color graphics.</li> 2712 <li>Devices MUST support displays capable of rendering animations.</li> 2713 <li>The display technology used MUST have a pixel aspect ratio (PAR) between 0.9 2714and 1.15. That is, the pixel aspect ratio MUST be near square (1.0) with a 10 ~ 271515% tolerance.</li> 2716</ul> 2717 2718<h3 id="7_1_7_external_displays">7.1.7. Secondary Displays</h3> 2719 2720 2721<p>Android includes support for secondary display to enable media sharing 2722capabilities and developer APIs for accessing external displays. If a device 2723supports an external display either via a wired, wireless, or an embedded 2724additional display connection then the device implementation MUST implement the 2725display 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> 2726 2727<h2 id="7_2_input_devices">7.2. Input Devices</h2> 2728 2729<p>Devices MUST support a touchscreen or meet the requirements listed in 7.2.2 2730for non-touch navigation.</p> 2731 2732<h3 id="7_2_1_keyboard">7.2.1. Keyboard</h3> 2733 2734<div class="note"> 2735<p>Android Watch and Android Automotive implementations MAY implement a soft 2736keyboard. All other device implementations MUST implement a soft keyboard and:</p> 2737</div> 2738 2739 2740<p>Device implementations:</p> 2741 2742<ul> 2743 <li>MUST include support for the Input Management Framework (which allows 2744third-party developers to create Input Method Editors—i.e. soft keyboard) as 2745detailed at <a href="http://developer.android.com">http://developer.android.com</a>.</li> 2746 <li>MUST provide at least one soft keyboard implementation (regardless of whether a 2747hard keyboard is present) except for Android Watch devices where the screen 2748size makes it less reasonable to have a soft keyboard.</li> 2749 <li>MAY include additional soft keyboard implementations.</li> 2750 <li>MAY include a hardware keyboard.</li> 2751 <li>MUST NOT include a hardware keyboard that does not match one of the formats 2752specified 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> 2753</ul> 2754 2755<h3 id="7_2_2_non-touch_navigation">7.2.2. Non-touch Navigation</h3> 2756 2757<div class="note"> 2758<p>Android Television devices MUST support D-pad.</p> 2759</div> 2760 2761<p>Device implementations:</p> 2762 2763<ul> 2764 <li>MAY omit a non-touch navigation option (trackball, d-pad, or wheel) if the 2765device implementation is not an Android Television device.</li> 2766 <li>MUST report the correct value for android.content.res.Configuration.navigation 2767[<a href="http://developer.android.com/reference/android/content/res/Configuration.html">Resources, 68</a>].</li> 2768 <li>MUST provide a reasonable alternative user interface mechanism for the 2769selection and editing of text, compatible with Input Management Engines. The 2770upstream Android open source implementation includes a selection mechanism 2771suitable for use with devices that lack non-touch navigation inputs.</li> 2772</ul> 2773 2774<h3 id="7_2_3_navigation_keys">7.2.3. Navigation Keys</h3> 2775 2776<div class="note"> 2777<p>The availability and visibility requirement of the Home, Recents, and Back 2778functions differ between device types as described in this section.</p> 2779</div> 2780 2781<p>The Home, Recents, and Back functions (mapped to the key events KEYCODE_HOME, 2782KEYCODE_APP_SWITCH, KEYCODE_BACK, respectively) are essential to the Android 2783navigation paradigm and therefore:</p> 2784 2785<ul> 2786 <li>Android Handheld device implementations MUST provide the Home, Recents, and 2787Back functions.</li> 2788 <li>Android Television device implementations MUST provide the Home and Back 2789functions.</li> 2790 <li>Android Watch device implementations MUST have the Home function available to 2791the user, and the Back function except for when it is in UI_MODE_TYPE_WATCH.</li> 2792 <li>Android Automotive implementations MUST provide the Home function and MAY 2793provide Back and Recent functions.</li> 2794 <li>All other types of device implementations MUST provide the Home and Back 2795functions.</li> 2796</ul> 2797 2798<p>These functions MAY be implemented via dedicated physical buttons (such as 2799mechanical or capacitive touch buttons), or MAY be implemented using dedicated 2800software keys on a distinct portion of the screen, gestures, touch panel, etc. 2801Android supports both implementations. All of these functions MUST be 2802accessible with a single action (e.g. tap, double-click or gesture) when 2803visible.</p> 2804 2805<p>Recents function, if provided, MUST have a visible button or icon unless hidden 2806together with other navigation functions in full-screen mode. This does not 2807apply to devices upgrading from earlier Android versions that have physical 2808buttons for navigation and no recents key.</p> 2809 2810<p> The Home and Back functions, if provided, MUST each have a visible button or 2811icon unless hidden together with other navigation functions in full-screen mode 2812or when the uiMode UI_MODE_TYPE_MASK is set to UI_MODE_TYPE_WATCH.</p> 2813 2814<p>The Menu function is deprecated in favor of action bar since Android 4.0. 2815Therefore the new device implementations shipping with Android ANDROID_VERSION and later MUST NOT 2816implement a dedicated physical button for the Menu function. Older device 2817implementations SHOULD NOT implement a dedicated physical button for the Menu 2818function, but if the physical Menu button is implemented and the device is 2819running applications with targetSdkVersion > 10, the device implementation:</p> 2820 2821<ul> 2822 <li>MUST display the action overflow button on the action bar when it is visible 2823and the resulting action overflow menu popup is not empty. For a device 2824implementation launched before Android 4.4 but upgrading to Android ANDROID_VERSION, this 2825is RECOMMENDED.</li> 2826 <li>MUST NOT modify the position of the action overflow popup displayed by 2827selecting the overflow button in the action bar.</li> 2828 <li>MAY render the action overflow popup at a modified position on the screen when 2829it is displayed by selecting the physical menu button.</li> 2830</ul> 2831 2832<p>For backwards compatibility, device implementations MUST make the Menu function 2833available to applications when targetSdkVersion is less than 10, either by a physical 2834button, a software key, or gestures. This Menu function should be presented 2835unless hidden together with other navigation functions.</p> 2836 2837<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 2838the Assist action available to the user at all times when running applications. 2839The Assist action SHOULD be implemented as a long-press on the Home button or a 2840swipe-up gesture on the software Home key. This function MAY be implemented via 2841another physical button, software key, or gesture, but MUST be accessible with 2842a single action (e.g. tap, double-click, or gesture) when other navigation keys 2843are visible.</p> 2844 2845<p>Device implementations MAY use a distinct portion of the screen to display the 2846navigation keys, but if so, MUST meet these requirements:</p> 2847 2848<ul> 2849 <li>Device implementation navigation keys MUST use a distinct portion of the 2850screen, not available to applications, and MUST NOT obscure or otherwise 2851interfere with the portion of the screen available to applications.</li> 2852 <li>Device implementations MUST make available a portion of the display to 2853applications that meets the requirements defined in <a href="#7_1_1_screen_configuration">section 7.1.1</a>.</li> 2854 <li>Device implementations MUST display the navigation keys when applications do 2855not specify a system UI mode, or specify SYSTEM_UI_FLAG_VISIBLE.</li> 2856 <li>Device implementations MUST present the navigation keys in an unobtrusive “low 2857profile” (eg. dimmed) mode when applications specify 2858SYSTEM_UI_FLAG_LOW_PROFILE.</li> 2859 <li>Device implementations MUST hide the navigation keys when applications specify 2860SYSTEM_UI_FLAG_HIDE_NAVIGATION.</li> 2861</ul> 2862 2863<h3 id="7_2_4_touchscreen_input">7.2.4. Touchscreen Input</h3> 2864 2865<div class="note"> 2866<p>Android Handhelds and Watch Devices MUST support touchscreen input.</p> 2867</div> 2868 2869 2870<p>Device implementations SHOULD have a pointer input system of some kind (either 2871mouse-like or touch). However, if a device implementation does not support a 2872pointer input system, it MUST NOT report the android.hardware.touchscreen or 2873android.hardware.faketouch feature constant. Device implementations that do 2874include a pointer input system:</p> 2875 2876<ul> 2877 <li>SHOULD support fully independently tracked pointers, if the device input system 2878supports multiple pointers.</li> 2879 <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> 2880</ul> 2881 2882<p>Android includes support for a variety of touchscreens, touch pads, and fake 2883touch input devices. Touchscreen based device implementations are associated 2884with 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 2885screen. Since the user is directly touching the screen, the system does not 2886require any additional affordances to indicate the objects being manipulated. 2887In contrast, a fake touch interface provides a user input system that 2888approximates a subset of touchscreen capabilities. For example, a mouse or 2889remote control that drives an on-screen cursor approximates touch, but requires 2890the user to first point or focus then click. Numerous input devices like the 2891mouse, trackpad, gyro-based air mouse, gyro-pointer, joystick, and multi-touch 2892trackpad can support fake touch interactions. Android includes the feature 2893constant android.hardware.faketouch, which corresponds to a high-fidelity 2894non-touch (pointer-based) input device such as a mouse or trackpad that can 2895adequately emulate touch-based input (including basic gesture support), and 2896indicates that the device supports an emulated subset of touchscreen 2897functionality. Device implementations that declare the fake touch feature MUST 2898meet the fake touch requirements in <a href="#7_2_5_fake_touch_input">section 7.2.5</a>.</p> 2899 2900<p>Device implementations MUST report the correct feature corresponding to the 2901type of input used. Device implementations that include a touchscreen 2902(single-touch or better) MUST report the platform feature constant 2903android.hardware.touchscreen. Device implementations that report the platform 2904feature constant android.hardware.touchscreen MUST also report the platform 2905feature constant android.hardware.faketouch. Device implementations that do not 2906include a touchscreen (and rely on a pointer device only) MUST NOT report any 2907touchscreen feature, and MUST report only android.hardware.faketouch if they 2908meet the fake touch requirements in <a href="#7_2_5_fake_touch_input">section 7.2.5</a>.</p> 2909 2910<h3 id="7_2_5_fake_touch_input">7.2.5. Fake Touch Input</h3> 2911 2912 2913<p>Device implementations that declare support for android.hardware.faketouch:</p> 2914 2915<ul> 2916 <li>MUST report the absolute X and Y screen positions of the pointer location and 2917display a visual pointer on the screen [<a href="http://developer.android.com/reference/android/view/MotionEvent.html">Resources, 71</a>].</li> 2918 <li>MUST report touch event with the action code that specifies the state change 2919that 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> 2920 <li>MUST support pointer down and up on an object on the screen, which allows users 2921to emulate tap on an object on the screen.</li> 2922 <li>MUST support pointer down, pointer up, pointer down then pointer up in the same 2923place on an object on the screen within a time threshold, which allows users to 2924emulate double tap on an object on the screen [<a href="http://developer.android.com/reference/android/view/MotionEvent.html">Resources, 71</a>].</li> 2925 <li>MUST support pointer down on an arbitrary point on the screen, pointer move to 2926any other arbitrary point on the screen, followed by a pointer up, which allows 2927users to emulate a touch drag.</li> 2928 <li>MUST support pointer down then allow users to quickly move the object to a 2929different position on the screen and then pointer up on the screen, which 2930allows users to fling an object on the screen.</li> 2931</ul> 2932 2933<p>Devices that declare support for android.hardware.faketouch.multitouch.distinct 2934MUST meet the requirements for faketouch above, and MUST also support distinct 2935tracking of two or more independent pointer inputs.</p> 2936 2937<h3 id="7_2_6_game_controller_support">7.2.6. Game Controller Support</h3> 2938 2939 2940<p>Android Television device implementations MUST support button mappings for game 2941controllers as listed below. The upstream Android implementation includes 2942implementation for game controllers that satisfies this requirement. </p> 2943 2944<h4 id="7_2_6_1_button_mappings">7.2.6.1. Button Mappings</h4> 2945 2946 2947<p>Android Television device implementations MUST support the following key 2948mappings:</p> 2949<table> 2950 <tr> 2951 <th>Button</th> 2952 <th>HID Usage</strong><sup>2</sup></td> 2953 <th>Android Button</th> 2954 </tr> 2955 <tr> 2956 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BUTTON_A">A</a><sup>1</sup></td> 2957 <td>0x09 0x0001</td> 2958 <td>KEYCODE_BUTTON_A (96)</td> 2959 </tr> 2960 <tr> 2961 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BUTTON_B">B</a><sup>1</sup></td> 2962 <td>0x09 0x0002</td> 2963 <td>KEYCODE_BUTTON_B (97)</td> 2964 </tr> 2965 <tr> 2966 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BUTTON_X">X</a><sup>1</sup></td> 2967 <td>0x09 0x0004</td> 2968 <td>KEYCODE_BUTTON_X (99)</td> 2969 </tr> 2970 <tr> 2971 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BUTTON_Y">Y</a><sup>1</sup></td> 2972 <td>0x09 0x0005</td> 2973 <td>KEYCODE_BUTTON_Y (100)</td> 2974 </tr> 2975 <tr> 2976 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_DPAD_UP">D-pad up</a><sup>1</sup></p> 2977 2978<p><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_DPAD_DOWN">D-pad down</a><sup>1</sup></td> 2979 <td>0x01 0x0039<sup>3</sup></td> 2980 <td><a href="http://developer.android.com/reference/android/view/MotionEvent.html#AXIS_HAT_Y">AXIS_HAT_Y</a><sup>4</sup></td> 2981 </tr> 2982 <tr> 2983 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_DPAD_LEFT">D-pad left</a>1</p> 2984 2985<p><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_DPAD_RIGHT">D-pad right</a><sup>1</sup></td> 2986 <td>0x01 0x0039<sup>3</sup></td> 2987 <td><a href="http://developer.android.com/reference/android/view/MotionEvent.html#AXIS_HAT_X">AXIS_HAT_X</a><sup>4</sup></td> 2988 </tr> 2989 <tr> 2990 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BUTTON_L1">Left shoulder button</a><sup>1</sup></td> 2991 <td>0x09 0x0007</td> 2992 <td>KEYCODE_BUTTON_L1 (102)</td> 2993 </tr> 2994 <tr> 2995 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BUTTON_R1">Right shoulder button</a><sup>1</sup></td> 2996 <td>0x09 0x0008</td> 2997 <td>KEYCODE_BUTTON_R1 (103)</td> 2998 </tr> 2999 <tr> 3000 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BUTTON_THUMBL">Left stick click</a><sup>1</sup></td> 3001 <td>0x09 0x000E</td> 3002 <td>KEYCODE_BUTTON_THUMBL (106)</td> 3003 </tr> 3004 <tr> 3005 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BUTTON_THUMBR">Right stick click</a><sup>1</sup></td> 3006 <td>0x09 0x000F</td> 3007 <td>KEYCODE_BUTTON_THUMBR (107)</td> 3008 </tr> 3009 <tr> 3010 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_HOME">Home</a><sup>1</sup></td> 3011 <td>0x0c 0x0223</td> 3012 <td>KEYCODE_HOME (3)</td> 3013 </tr> 3014 <tr> 3015 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BACK">Back</a><sup>1</sup></td> 3016 <td>0x0c 0x0224</td> 3017 <td>KEYCODE_BACK (4)</td> 3018 </tr> 3019</table> 3020 3021 3022<p class="table_footnote">1 [<a href="http://developer.android.com/reference/android/view/KeyEvent.html">Resources, 72</a>]</p> 3023 3024<p class="table_footnote">2 The above HID usages must be declared within a Game pad CA (0x01 0x0005).</p> 3025 3026<p class="table_footnote">3 This usage must have a Logical Minimum of 0, a Logical Maximum of 7, a 3027Physical Minimum of 0, a Physical Maximum of 315, Units in Degrees, and a 3028Report Size of 4. The logical value is defined to be the clockwise rotation 3029away from the vertical axis; for example, a logical value of 0 represents no 3030rotation and the up button being pressed, while a logical value of 1 represents 3031a rotation of 45 degrees and both the up and left keys being pressed.</p> 3032 3033<p class="table_footnote">4 [<a href="http://developer.android.com/reference/android/view/MotionEvent.html">Resources, 71</a>]</p> 3034 3035<table> 3036 <tr> 3037 <th>Analog Controls</strong><sup>1</sup></td> 3038 <th>HID Usage</th> 3039 <th>Android Button</th> 3040 </tr> 3041 <tr> 3042 <td><a href="http://developer.android.com/reference/android/view/MotionEvent.html#AXIS_LTRIGGER">Left Trigger</a></td> 3043 <td>0x02 0x00C5</td> 3044 <td>AXIS_LTRIGGER </td> 3045 </tr> 3046 <tr> 3047 <td><a href="http://developer.android.com/reference/android/view/MotionEvent.html#AXIS_THROTTLE">Right Trigger</a></td> 3048 <td>0x02 0x00C4</td> 3049 <td>AXIS_RTRIGGER </td> 3050 </tr> 3051 <tr> 3052 <td><a href="http://developer.android.com/reference/android/view/MotionEvent.html#AXIS_Y">Left Joystick</a></td> 3053 <td>0x01 0x0030</p> 3054 3055<p>0x01 0x0031</td> 3056 <td>AXIS_X</p> 3057 3058<p>AXIS_Y</td> 3059 </tr> 3060 <tr> 3061 <td><a href="http://developer.android.com/reference/android/view/MotionEvent.html#AXIS_Z">Right Joystick</a></td> 3062 <td>0x01 0x0032</p> 3063 3064<p>0x01 0x0035</td> 3065 <td>AXIS_Z</p> 3066 3067<p>AXIS_RZ</td> 3068 </tr> 3069</table> 3070 3071 3072<p class="table_footnote">1 [<a href="http://developer.android.com/reference/android/view/MotionEvent.html">Resources, 71</a>]</p> 3073 3074<h3 id="7_2_7_remote_control">7.2.7. Remote Control</h3> 3075 3076 3077<p>Android Television device implementations SHOULD provide a remote control to 3078allow users to access the TV interface. The remote control MAY be a physical 3079remote or can be a software-based remote that is accessible from a mobile phone 3080or tablet. The remote control MUST meet the requirements defined below.</p> 3081 3082<ul> 3083 <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> 3084 <li><strong>Navigation</strong>. All Android Television remotes MUST include Back, Home, and Select buttons and 3085support for D-pad events [<a href="http://developer.android.com/reference/android/view/KeyEvent.html">Resources, 72</a>].</li> 3086</ul> 3087 3088<h2 id="7_3_sensors">7.3. Sensors</h2> 3089 3090 3091<p>Android includes APIs for accessing a variety of sensor types. Devices 3092implementations generally MAY omit these sensors, as provided for in the 3093following subsections. If a device includes a particular sensor type that has a 3094corresponding API for third-party developers, the device implementation MUST 3095implement that API as described in the Android SDK documentation and the 3096Android Open Source documentation on sensors [<a href="http://source.android.com/devices/sensors/">Resources, 73</a>]. For example, device implementations:</p> 3097 3098<ul> 3099 <li>MUST accurately report the presence or absence of sensors per the 3100android.content.pm.PackageManager class [<a href="http://developer.android.com/reference/android/content/pm/PackageManager.html">Resources, 53]</a>.</li> 3101 <li>MUST return an accurate list of supported sensors via the 3102SensorManager.getSensorList() and similar methods.</li> 3103 <li>MUST behave reasonably for all other sensor APIs (for example, by returning 3104true or false as appropriate when applications attempt to register listeners, 3105not calling sensor listeners when the corresponding sensors are not present; 3106etc.).</li> 3107 <li>MUST report all sensor measurements using the relevant International System of 3108Units (metric) values for each sensor type as defined in the Android SDK 3109documentation [<a href="http://developer.android.com/reference/android/hardware/SensorEvent.html">Resources, 74</a>].</li> 3110 <li>SHOULD report the event time in nanoseconds as defined in the Android SDK 3111documentation, representing the time the event happened and synchronized with 3112the SystemClock.elapsedRealtimeNano() clock. Existing and new Android devices 3113are <strong>very strongly encouraged</strong> to meet these requirement so they will be able to upgrade to the future 3114platform releases where this might become a REQUIRED component. The 3115synchronization error SHOULD be below 100 milliseconds [<a href="http://developer.android.com/reference/android/hardware/SensorEvent.html#timestamp">Resources, 75</a>].</li> 3116</ul> 3117 3118<p>The list above is not comprehensive; the documented behavior of the Android SDK 3119and the Android Open Source Documentations on Sensors [<a href="http://source.android.com/devices/sensors/">Resources, 73</a>] is to be considered authoritative.</p> 3120 3121<p>Some sensor types are composite, meaning they can be derived from data provided 3122by one or more other sensors. (Examples include the orientation sensor, and the 3123linear acceleration sensor.) Device implementations SHOULD implement these 3124sensor types, when they include the prerequisite physical sensors as described 3125in [<a href="https://source.android.com/devices/sensors/sensor-types.html">Resources, 76</a>]. 3126If a device implementation includes a composite sensor it MUST implement the 3127sensor as described in the Android Open Source documentation on composite 3128sensors [<a href="https://source.android.com/devices/sensors/sensor-types.html#composite_sensor_type_summary">Resources, 76</a>].</p> 3129 3130<p>Some Android sensors support a “continuous” trigger mode, which returns data 3131continuously [<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 3132sensor, device implementations MUST continuously provide periodic data samples 3133that SHOULD have a jitter below 3%, where jitter is defined as the standard 3134deviation of the difference of the reported timestamp values between 3135consecutive events.</p> 3136 3137<p>Note that the device implementations MUST ensure that the sensor event stream 3138MUST NOT prevent the device CPU from entering a suspend state or waking up from 3139a suspend state.</p> 3140 3141<p>Finally, when several sensors are activated, the power consumption SHOULD NOT 3142exceed the sum of the individual sensor’s reported power consumption.</p> 3143 3144<h3 id="7_3_1_accelerometer">7.3.1. Accelerometer</h3> 3145 3146 3147<p>Device implementations SHOULD include a 3-axis accelerometer. Android Handheld 3148devices and Android Watch devices are strongly encouraged to include this 3149sensor. If a device implementation does include a 3-axis accelerometer, it:</p> 3150 3151<ul> 3152 <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> 3153 <li>MUST be able to report events up to a frequency of at least 50 Hz for 3154 Android Watch devices as such devices have a stricter power constraint and 3155 100 Hz for all other device types.</li> 3156 <li>SHOULD report events up to at least 200 Hz.</li> 3157 <li>MUST comply with the Android sensor coordinate system as detailed in the 3158Android APIs [<a href="http://developer.android.com/reference/android/hardware/SensorEvent.html">Resources, 74</a>].</li> 3159 <li>MUST be capable of measuring from freefall up to four times the gravity (4g) or 3160more on any axis.</li> 3161 <li>MUST have a resolution of at least 8-bits and SHOULD have a resolution of at 3162least 16-bits.</li> 3163 <li>SHOULD be calibrated while in use if the characteristics changes over the life 3164cycle and compensated, and preserve the compensation parameters between device 3165reboots.</li> 3166 <li>SHOULD be temperature compensated.</li> 3167 <li>MUST have a standard deviation no greater than 0.05 m/s^, where the standard 3168deviation should be calculated on a per axis basis on samples collected over a 3169period of at least 3 seconds at the fastest sampling rate.</li> 3170 <li>SHOULD implement the TYPE_SIGNIFICANT_MOTION, TYPE_TILT_DETECTOR, 3171TYPE_STEP_DETECTOR, TYPE_STEP_COUNTER composite sensors as described in the 3172Android 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 3173sensors are implemented, the sum of their power consumption MUST always be less 3174than 4 mW and SHOULD each be below 2 mW and 0.5 mW for when the device is in a 3175dynamic or static condition.</li> 3176 <li>If a gyroscope sensor is included, MUST implement the TYPE_GRAVITY and 3177TYPE_LINEAR_ACCELERATION composite sensors and SHOULD implement the 3178TYPE_GAME_ROTATION_VECTOR composite sensor. Existing and new Android devices 3179are strongly encouraged to implement the TYPE_GAME_ROTATION_VECTOR sensor.</li> 3180 <li>SHOULD implement a TYPE_ROTATION_VECTOR composite sensor, if a gyroscope sensor 3181and a magnetometer sensor is also included.</li> 3182</ul> 3183 3184<h3 id="7_3_2_magnetometer">7.3.2. Magnetometer</h3> 3185 3186 3187<p>Device implementations SHOULD include a 3-axis magnetometer (compass). If a 3188device does include a 3-axis magnetometer, it:</p> 3189 3190<ul> 3191 <li>MUST implement the TYPE_MAGNETIC_FIELD sensor and SHOULD also implement 3192TYPE_MAGNETIC_FIELD_UNCALIBRATED sensor. Existing and new Android devices are 3193strongly encouraged to implement the TYPE_MAGNETIC_FIELD_UNCALIBRATED sensor.</li> 3194 <li>MUST be able to report events up to a frequency of at least 10 Hz and SHOULD 3195report events up to at least 50 Hz.</li> 3196 <li>MUST comply with the Android sensor coordinate system as detailed in the 3197Android APIs [<a href="http://developer.android.com/reference/android/hardware/SensorEvent.html">Resources, 74</a>].</li> 3198 <li>MUST be capable of measuring between -900 µT and +900 µT on each axis before 3199saturating.</li> 3200 <li>MUST have a hard iron offset value less than 700 µT and SHOULD have a value 3201below 200 µT, by placing the magnetometer far from dynamic (current-induced) 3202and static (magnet-induced) magnetic fields.</li> 3203 <li>MUST have a resolution equal or denser than 0.6 µT and SHOULD have a resolution 3204equal or denser than 0.2 µ.</li> 3205 <li>SHOULD be temperature compensated.</li> 3206 <li>MUST support online calibration and compensation of the hard iron bias, and 3207preserve the compensation parameters between device reboots.</li> 3208 <li>MUST have the soft iron compensation applied—the calibration can be done either 3209while in use or during the production of the device.</li> 3210 <li>SHOULD have a standard deviation, calculated on a per axis basis on samples 3211collected over a period of at least 3 seconds at the fastest sampling rate, no 3212greater than 0.5 µT.</li> 3213 <li>SHOULD implement a TYPE_ROTATION_VECTOR composite sensor, if an accelerometer 3214sensor and a gyroscope sensor is also included.</li> 3215 <li>MAY implement the TYPE_GEOMAGNETIC_ROTATION_VECTOR sensor if an accelerometer 3216sensor is also implemented. However if implemented, it MUST consume less than 321710 mW and SHOULD consume less than 3 mW when the sensor is registered for batch 3218mode at 10 Hz.</li> 3219</ul> 3220 3221<h3 id="7_3_3_gps">7.3.3. GPS</h3> 3222 3223 3224<p>Device implementations SHOULD include a GPS receiver. If a device 3225implementation does include a GPS receiver, it SHOULD include some form of“assisted GPS” technique to minimize GPS lock-on time.</p> 3226 3227<h3 id="7_3_4_gyroscope">7.3.4. Gyroscope</h3> 3228 3229 3230<p>Device implementations SHOULD include a gyroscope (angular change sensor). 3231Devices SHOULD NOT include a gyroscope sensor unless a 3-axis accelerometer is 3232also included. If a device implementation includes a gyroscope, it:</p> 3233 3234<ul> 3235 <li>MUST implement the TYPE_GYROSCOPE sensor and SHOULD also implement 3236TYPE_GYROSCOPE_UNCALIBRATED sensor. Existing and new Android devices are 3237strongly encouraged to implement the SENSOR_TYPE_GYROSCOPE_UNCALIBRATED sensor.</li> 3238 <li>MUST be capable of measuring orientation changes up to 1,000 degrees per second.</li> 3239 <li>MUST be able to report events up to a frequency of at least 50 Hz for 3240 Android Watch devices as such devices have a stricter power constraint and 3241 100 Hz for all other device types.</li> 3242 <li>SHOULD report events up to at least 200 Hz.</li> 3243 <li>MUST have a resolution of 12-bits or more and SHOULD have a resolution of 324416-bits or more.</li> 3245 <li>MUST be temperature compensated.</li> 3246 <li>MUST be calibrated and compensated while in use, and preserve the compensation 3247parameters between device reboots.</li> 3248 <li>MUST have a variance no greater than 1e-7 rad^2 / s^2 per Hz (variance per Hz, 3249or rad^2 / s). The variance is allowed to vary with the sampling rate, but must 3250be constrained by this value. In other words, if you measure the variance of 3251the gyro at 1 Hz sampling rate it should be no greater than 1e-7 rad^2/s^2.</li> 3252 <li>SHOULD implement a TYPE_ROTATION_VECTOR composite sensor, if an accelerometer 3253sensor and a magnetometer sensor is also included.</li> 3254 <li>If an accelerometer sensor is included, MUST implement the TYPE_GRAVITY and 3255TYPE_LINEAR_ACCELERATION composite sensors and SHOULD implement the 3256TYPE_GAME_ROTATION_VECTOR composite sensor. Existing and new Android devices 3257are strongly encouraged to implement the TYPE_GAME_ROTATION_VECTOR sensor.</li> 3258</ul> 3259 3260<h3 id="7_3_5_barometer">7.3.5. Barometer</h3> 3261 3262 3263<p>Device implementations SHOULD include a barometer (ambient air pressure 3264sensor). If a device implementation includes a barometer, it:</p> 3265 3266<ul> 3267 <li>MUST implement and report TYPE_PRESSURE sensor.</li> 3268 <li>MUST be able to deliver events at 5 Hz or greater.</li> 3269 <li>MUST have adequate precision to enable estimating altitude.</li> 3270 <li>MUST be temperature compensated.</li> 3271</ul> 3272 3273<h3 id="7_3_6_thermometer">7.3.6. Thermometer</h3> 3274 3275 3276<p>Device implementations MAY include an ambient thermometer (temperature sensor). 3277If present, it MUST be defined as SENSOR_TYPE_AMBIENT_TEMPERATURE and it MUST 3278measure the ambient (room) temperature in degrees Celsius.</p> 3279 3280<p>Device implementations MAY but SHOULD NOT include a CPU temperature sensor. If 3281present, it MUST be defined as SENSOR_TYPE_TEMPERATURE, it MUST measure the 3282temperature of the device CPU, and it MUST NOT measure any other temperature. 3283Note the SENSOR_TYPE_TEMPERATURE sensor type was deprecated in Android 4.0.</p> 3284 3285<h3 id="7_3_7_photometer">7.3.7. Photometer</h3> 3286 3287 3288<p>Device implementations MAY include a photometer (ambient light sensor).</p> 3289 3290<h3 id="7_3_8_proximity_sensor">7.3.8. Proximity Sensor</h3> 3291 3292 3293<p>Device implementations MAY include a proximity sensor. Devices that can make a 3294voice call and indicate any value other than PHONE_TYPE_NONE in getPhoneType 3295SHOULD include a proximity sensor. If a device implementation does include a 3296proximity sensor, it:</p> 3297 3298<ul> 3299 <li>MUST measure the proximity of an object in the same direction as the screen. 3300That is, the proximity sensor MUST be oriented to detect objects close to the 3301screen, as the primary intent of this sensor type is to detect a phone in use 3302by the user. If a device implementation includes a proximity sensor with any 3303other orientation, it MUST NOT be accessible through this API.</li> 3304 <li>MUST have 1-bit of accuracy or more.</li> 3305</ul> 3306 3307<h2 id="7_4_data_connectivity">7.4. Data Connectivity</h2> 3308 3309 3310<h3 id="7_4_1_telephony">7.4.1. Telephony</h3> 3311 3312 3313<p>“Telephony” as used by the Android APIs and this document refers specifically 3314to hardware related to placing voice calls and sending SMS messages via a GSM 3315or CDMA network. While these voice calls may or may not be packet-switched, 3316they are for the purposes of Android considered independent of any data 3317connectivity that may be implemented using the same network. In other words, 3318the Android “telephony” functionality and APIs refer specifically to voice 3319calls and SMS. For instance, device implementations that cannot place calls or 3320send/receive SMS messages MUST NOT report the android.hardware.telephony 3321feature or any subfeatures, regardless of whether they use a cellular network 3322for data connectivity.</p> 3323 3324<p>Android MAY be used on devices that do not include telephony hardware. That is, 3325Android is compatible with devices that are not phones. However, if a device 3326implementation does include GSM or CDMA telephony, it MUST implement full 3327support for the API for that technology. Device implementations that do not 3328include telephony hardware MUST implement the full APIs as no-ops.</p> 3329 3330<h3 id="7_4_2_ieee_802_11_wi-fi">7.4.2. IEEE 802.11 (Wi-Fi)</h3> 3331 3332<div class="note"> 3333<p>Android Television device implementations MUST include Wi-Fi support.</p> 3334</div> 3335 3336 3337<p>Android Television device implementations MUST include support for one or more 3338forms of 802.11 (b/g/a/n, etc.) and other types of Android device 3339implementation SHOULD include support for one or more forms of 802.11. If a 3340device implementation does include support for 802.11 and exposes the 3341functionality to a third-party application, it MUST implement the corresponding 3342Android API and:</p> 3343 3344<ul> 3345 <li>MUST report the hardware feature flag android.hardware.wifi.</li> 3346 <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> 3347 <li>MUST support multicast DNS (mDNS) and MUST NOT filter mDNS packets 3348(224.0.0.251) at any time of operation including when the screen is not in an 3349active state.</li> 3350</ul> 3351 3352<h4 id="7_4_2_1_wi-fi_direct">7.4.2.1. Wi-Fi Direct</h4> 3353 3354 3355<p>Device implementations SHOULD include support for Wi-Fi Direct (Wi-Fi 3356peer-to-peer). If a device implementation does include support for Wi-Fi 3357Direct, it MUST implement the corresponding Android API as described in the SDK 3358documentation [<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> 3359 3360<ul> 3361 <li>MUST report the hardware feature android.hardware.wifi.direct.</li> 3362 <li>MUST support regular Wi-Fi operation.</li> 3363 <li>SHOULD support concurrent Wi-Fi and Wi-Fi Direct operation.</li> 3364</ul> 3365 3366<h4 id="7_4_2_2_wi-fi_tunneled_direct_link_setup">7.4.2.2. Wi-Fi Tunneled Direct Link Setup</h4> 3367 3368<div class="note"> 3369<p>Android Television device implementations MUST include support for Wi-Fi 3370Tunneled Direct Link Setup (TDLS).</p> 3371</div> 3372 3373 3374<p>Android Television device implementations MUST include support for Wi-Fi 3375Tunneled Direct Link Setup (TDLS) and other types of Android device 3376implementations SHOULD include support for Wi-Fi TDLS as described in the 3377Android 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 3378by the WiFiManager API, the device:</p> 3379 3380<ul> 3381 <li>SHOULD use TDLS only when it is possible AND beneficial.</li> 3382 <li>SHOULD have some heuristic and NOT use TDLS when its performance might be worse 3383than going through the Wi-Fi access point.</li> 3384</ul> 3385 3386<h3 id="7_4_3_bluetooth">7.4.3. Bluetooth</h3> 3387 3388<div class="note"> 3389<p>Android Watch and Automotive implementations MUST support Bluetooth. Android 3390Television implementations MUST support Bluetooth and Bluetooth LE.</p> 3391</div> 3392 3393 3394<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 3395Energy MUST declare the relevant platform features (android.hardware.bluetooth 3396and android.hardware.bluetooth_le respectively) and implement the platform 3397APIs. Device implementations SHOULD implement relevant Bluetooth profiles such 3398as A2DP, AVCP, OBEX, etc. as appropriate for the device. Android Television 3399device implementations MUST support Bluetooth and Bluetooth LE. </p> 3400 3401<p>Device implementations including support for Bluetooth Low Energy:</p> 3402 3403<ul> 3404 <li>MUST declare the hardware feature android.hardware.bluetooth_le.</li> 3405 <li>MUST enable the GATT (generic attribute profile) based Bluetooth APIs as 3406described in the SDK documentation and [<a href="http://developer.android.com/reference/android/bluetooth/package-summary.html">Resources, 82</a>].</li> 3407 <li>SHOULD support offloading of the filtering logic to the bluetooth chipset when 3408implementing 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 3409android.bluetooth.BluetoothAdapter.isOffloadedFilteringSupported() method.</li> 3410 <li>SHOULD support offloading of the batched scanning to the bluetooth chipset, but 3411if not supported, MUST report ‘false’ whenever queried via the 3412android.bluetooth.BluetoothAdapater.isOffloadedScanBatchingSupported() method.</li> 3413 <li>SHOULD support multi advertisement with at least 4 slots, but if not supported, 3414MUST report ‘false’ whenever queried via the 3415android.bluetooth.BluetoothAdapter.isMultipleAdvertisementSupported() method.</li> 3416</ul> 3417 3418<h3 id="7_4_4_near-field_communications">7.4.4. Near-Field Communications</h3> 3419 3420 3421<p>Device implementations SHOULD include a transceiver and related hardware for 3422Near-Field Communications (NFC). If a device implementation does include NFC 3423hardware and plans to make it available to third-party apps, then it:</p> 3424 3425<ul> 3426 <li>MUST report the android.hardware.nfc feature from the 3427android.content.pm.PackageManager.hasSystemFeature() method [<a href="http://developer.android.com/reference/android/content/pm/PackageManager.html">Resources, 53</a>].</li> 3428 <li>MUST be capable of reading and writing NDEF messages via the following NFC 3429standards: 3430 <ul> 3431 <li>MUST be capable of acting as an NFC Forum reader/writer (as defined by the NFC 3432Forum technical specification NFCForum-TS-DigitalProtocol-1.0) via the 3433following NFC standards: 3434 <ul> 3435 <li>NfcA (ISO14443-3A)</li> 3436 <li>NfcB (ISO14443-3B)</li> 3437 <li>NfcF (JIS 6319-4)</li> 3438 <li>IsoDep (ISO 14443-4)</li> 3439 <li>NFC Forum Tag Types 1, 2, 3, 4 (defined by the NFC Forum)</li> 3440 </ul> 3441 <li>SHOULD be capable of reading and writing NDEF messages via the following NFC 3442standards. Note that while the NFC standards below are stated as SHOULD, the 3443Compatibility Definition for a future version is planned to change these to 3444MUST. These standards are optional in this version but will be required in 3445future 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> 3446 <ul> 3447 <li>NfcV (ISO 15693)</li> 3448 </ul></li> 3449 <li>MUST be capable of transmitting and receiving data via the following 3450peer-to-peer standards and protocols: 3451 <ul> 3452 <li>ISO 18092</li> 3453 <li>LLCP 1.0 (defined by the NFC Forum)</li> 3454 <li>SDP 1.0 (defined by the NFC Forum)</li> 3455 <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> 3456 <li>SNEP 1.0 (defined by the NFC Forum)</li> 3457 </ul></li> 3458 <li>MUST include support for Android Beam [<a href="http://developer.android.com/guide/topics/connectivity/nfc/nfc.html">Resources, 85</a>]: 3459 <ul> 3460 <li>MUST implement the SNEP default server. Valid NDEF messages received by the 3461default SNEP server MUST be dispatched to applications using the 3462android.nfc.ACTION_NDEF_DISCOVERED intent. Disabling Android Beam in settings 3463MUST NOT disable dispatch of incoming NDEF message.</li> 3464 <li>MUST honor the android.settings.NFCSHARING_SETTINGS intent to show NFC sharing 3465settings [<a href="http://developer.android.com/reference/android/provider/Settings.html#ACTION_NFCSHARING_SETTINGS">Resources, 86</a>].</li> 3466 <li>MUST implement the NPP server. Messages received by the NPP server MUST be 3467processed the same way as the SNEP default server.</li> 3468 <li>MUST implement a SNEP client and attempt to send outbound P2P NDEF to the 3469default SNEP server when Android Beam is enabled. If no default SNEP server is 3470found then the client MUST attempt to send to an NPP server.</li> 3471 <li>MUST allow foreground activities to set the outbound P2P NDEF message using 3472android.nfc.NfcAdapter.setNdefPushMessage, and 3473android.nfc.NfcAdapter.setNdefPushMessageCallback, and 3474android.nfc.NfcAdapter.enableForegroundNdefPush.</li> 3475 <li>SHOULD use a gesture or on-screen confirmation, such as 'Touch to Beam', before 3476sending outbound P2P NDEF messages.</li> 3477 <li>SHOULD enable Android Beam by default and MUST be able to send and receive 3478using Android Beam, even when another proprietary NFC P2p mode is turned on.</li> 3479 <li>MUST support NFC Connection handover to Bluetooth when the device supports 3480Bluetooth Object Push Profile. Device implementations MUST support connection 3481handover to Bluetooth when using android.nfc.NfcAdapter.setBeamPushUris, by 3482implementing 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 3483LLCP service with service name “urn:nfc:sn:handover” for exchanging the 3484handover request/select records over NFC, and it MUST use the Bluetooth Object 3485Push Profile for the actual Bluetooth data transfer. For legacy reasons (to 3486remain compatible with Android 4.1 devices), the implementation SHOULD still 3487accept SNEP GET requests for exchanging the handover request/select records 3488over NFC. However an implementation itself SHOULD NOT send SNEP GET requests 3489for performing connection handover.</li> 3490 </ul></li> 3491 <li>MUST poll for all supported technologies while in NFC discovery mode.</li> 3492 <li>SHOULD be in NFC discovery mode while the device is awake with the screen 3493active and the lock-screen unlocked.</li> 3494</ul> 3495</ul> 3496 3497<p>(Note that publicly available links are not available for the JIS, ISO, and NFC 3498Forum specifications cited above.)</p> 3499 3500<p>Android includes support for NFC Host Card Emulation (HCE) mode. If a 3501device implementation does include an NFC controller chipset capable of HCE and 3502Application ID (AID) routing, then it:</p> 3503 3504<ul> 3505 <li>MUST report the android.hardware.nfc.hce feature constant.</li> 3506 <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> 3507</ul> 3508 3509<p>Additionally, device implementations MAY include reader/writer support for the 3510following MIFARE technologies.</p> 3511 3512<ul> 3513 <li>MIFARE Classic</li> 3514 <li>MIFARE Ultralight</li> 3515 <li>NDEF on MIFARE Classic</li> 3516</ul> 3517 3518<p>Note that Android includes APIs for these MIFARE types. If a device 3519implementation supports MIFARE in the reader/writer role, it:</p> 3520 3521<ul> 3522 <li>MUST implement the corresponding Android APIs as documented by the Android SDK.</li> 3523 <li>MUST report the feature com.nxp.mifare from the 3524android.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 3525as a constant on the PackageManager class.</li> 3526 <li>MUST NOT implement the corresponding Android APIs nor report the com.nxp.mifare 3527feature unless it also implements general NFC support as described in this 3528section.</li> 3529</ul> 3530 3531<p>If a device implementation does not include NFC hardware, it MUST NOT declare 3532the android.hardware.nfc feature from the 3533android.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> 3534 3535<p>As the classes android.nfc.NdefMessage and android.nfc.NdefRecord represent a 3536protocol-independent data representation format, device implementations MUST 3537implement these APIs even if they do not include support for NFC or declare the 3538android.hardware.nfc feature.</p> 3539 3540<h3 id="7_4_5_minimum_network_capability">7.4.5. Minimum Network Capability</h3> 3541 3542 3543<p>Device implementations MUST include support for one or more forms of data 3544networking. Specifically, device implementations MUST include support for at 3545least one data standard capable of 200Kbit/sec or greater. Examples of 3546technologies that satisfy this requirement include EDGE, HSPA, EV-DO, 802.11g, 3547Ethernet, Bluetooth PAN, etc.</p> 3548 3549<p>Device implementations where a physical networking standard (such as Ethernet) 3550is the primary data connection SHOULD also include support for at least one 3551common wireless data standard, such as 802.11 (Wi-Fi).</p> 3552 3553<p>Devices MAY implement more than one form of data connectivity.</p> 3554 3555<h3 id="7_4_6_sync_settings">7.4.6. Sync Settings</h3> 3556 3557 3558<p>Device implementations MUST have the master auto-sync setting on by default so 3559that the method getMasterSyncAutomatically() returns “true” [<a href="http://developer.android.com/reference/android/content/ContentResolver.html">Resources, 89</a>].</p> 3560 3561<h2 id="7_5_cameras">7.5. Cameras</h2> 3562 3563 3564<p>Device implementations SHOULD include a rear-facing camera and MAY include a 3565front-facing camera. A rear-facing camera is a camera located on the side of 3566the device opposite the display; that is, it images scenes on the far side of 3567the device, like a traditional camera. A front-facing camera is a camera 3568located on the same side of the device as the display; that is, a camera 3569typically used to image the user, such as for video conferencing and similar 3570applications.</p> 3571 3572<p>If a device implementation includes at least one camera, it SHOULD be possible 3573for an application to simultaneously allocate 3 bitmaps equal to the size of 3574the images produced by the largest-resolution camera sensor on the device.</p> 3575 3576<h3 id="7_5_1_rear-facing_camera">7.5.1. Rear-Facing Camera</h3> 3577 3578 3579<p>Device implementations SHOULD include a rear-facing camera. If a device 3580implementation includes at least one rear-facing camera, it:</p> 3581 3582<ul> 3583 <li>MUST report the feature flag android.hardware.camera and 3584android.hardware.camera.any.</li> 3585 <li>MUST have a resolution of at least 2 megapixels.</li> 3586 <li>SHOULD have either hardware auto-focus or software auto-focus implemented in 3587the camera driver (transparent to application software).</li> 3588 <li>MAY have fixed-focus or EDOF (extended depth of field) hardware.</li> 3589 <li>MAY include a flash. If the Camera includes a flash, the flash lamp MUST NOT be 3590lit while an android.hardware.Camera.PreviewCallback instance has been 3591registered on a Camera preview surface, unless the application has explicitly 3592enabled the flash by enabling the FLASH_MODE_AUTO or FLASH_MODE_ON attributes 3593of a Camera.Parameters object. Note that this constraint does not apply to the 3594device’s built-in system camera application, but only to third-party 3595applications using Camera.PreviewCallback.</li> 3596</ul> 3597 3598<h3 id="7_5_2_front-facing_camera">7.5.2. Front-Facing Camera</h3> 3599 3600 3601<p>Device implementations MAY include a front-facing camera. If a device 3602implementation includes at least one front-facing camera, it:</p> 3603 3604<ul> 3605 <li>MUST report the feature flag android.hardware.camera.any and 3606android.hardware.camera.front.</li> 3607 <li>MUST have a resolution of at least VGA (640x480 pixels).</li> 3608 <li>MUST NOT use a front-facing camera as the default for the Camera API. The 3609camera API in Android has specific support for front-facing cameras and device 3610implementations MUST NOT configure the API to to treat a front-facing camera as 3611the default rear-facing camera, even if it is the only camera on the device.</li> 3612 <li>MAY include features (such as auto-focus, flash, etc.) available to rear-facing 3613cameras as described in <a href="#7_5_1_rear-facing_camera">section 7.5.1</a>.</li> 3614 <li>MUST horizontally reflect (i.e. mirror) the stream displayed by an app in a 3615CameraPreview, as follows: 3616 <ul> 3617 <li>If the device implementation is capable of being rotated by user (such as 3618automatically via an accelerometer or manually via user input), the camera 3619preview MUST be mirrored horizontally relative to the device’s current 3620orientation.</li> 3621 <li>If the current application has explicitly requested that the Camera display be 3622rotated 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 3623orientation specified by the application.</li> 3624 <li>Otherwise, the preview MUST be mirrored along the device’s default horizontal 3625axis.</li> 3626 </ul></li> 3627 <li>MUST mirror the image displayed by the postview in the same manner as the 3628camera preview image stream. If the device implementation does not support 3629postview, this requirement obviously does not apply.</li> 3630 <li>MUST NOT mirror the final captured still image or video streams returned to 3631application callbacks or committed to media storage.</li> 3632</ul> 3633 3634<h3 id="7_5_3_external_camera">7.5.3. External Camera</h3> 3635 3636 3637<p>Device implementations with USB host mode MAY include support for an external 3638camera that connects to the USB port. If a device includes support for an 3639external camera, it:</p> 3640 3641<ul> 3642 <li>MUST declare the platform feature android.hardware.camera.external and 3643android.hardware camera.any.</li> 3644 <li>MUST support USB Video Class (UVC 1.0 or higher).</li> 3645 <li>MAY support multiple cameras.</li> 3646</ul> 3647 3648<p>Video compression (such as MJPEG) support is RECOMMENDED to enable transfer of 3649high-quality unencoded streams (i.e. raw or independently compressed picture 3650streams). Camera-based video encoding MAY be supported. If so, a simultaneous 3651unencoded/ MJPEG stream (QVGA or greater resolution) MUST be accessible to the 3652device implementation.</p> 3653 3654<h3 id="7_5_4_camera_api_behavior">7.5.4. Camera API Behavior</h3> 3655 3656 3657<p>Android includes two API packages to access the camera, the newer 3658android.hardware.camera2 API expose lower-level camera control to the app, 3659including efficient zero-copy burst/streaming flows and per-frame controls of 3660exposure, gain, white balance gains, color conversion, denoising, sharpening, 3661and more.</p> 3662 3663<p>The older API package, android.hardware.Camera, is marked as deprecated in 3664Android 5.0 but as it should still be available for apps to use Android device 3665implementations MUST ensure the continued support of the API as described in 3666this section and in the Android SDK.</p> 3667 3668<p>Device implementations MUST implement the following behaviors for the 3669camera-related APIs, for all available cameras:</p> 3670 3671<ul> 3672 <li>If an application has never called 3673android.hardware.Camera.Parameters.setPreviewFormat(int), then the device MUST 3674use android.hardware.PixelFormat.YCbCr_420_SP for preview data provided to 3675application callbacks.</li> 3676 <li>If an application registers an android.hardware.Camera.PreviewCallback instance 3677and the system calls the onPreviewFrame() method when the preview format is 3678YCbCr_420_SP, the data in the byte[] passed into onPreviewFrame() must further 3679be in the NV21 encoding format. That is, NV21 MUST be the default.</li> 3680 <li>For android.hardware.Camera, device implementations MUST support the YV12 3681format (as denoted by the android.graphics.ImageFormat.YV12 constant) for 3682camera previews for both front- and rear-facing cameras. (The hardware video 3683encoder and camera may use any native pixel format, but the device 3684implementation MUST support conversion to YV12.)</li> 3685 <li>For android.hardware.camera2, device implementations must support the 3686android.hardware.ImageFormat.YUV_420_888 and android.hardware.ImageFormat.JPEG 3687formats as outputs through the android.media.ImageReader API.</li> 3688</ul> 3689 3690<p>Device implementations MUST still implement the full Camera API included in the 3691Android 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 3692capabilities. For instance, cameras that lack autofocus MUST still call any 3693registered android.hardware.Camera.AutoFocusCallback instances (even though 3694this has no relevance to a non-autofocus camera.) Note that this does apply to 3695front-facing cameras; for instance, even though most front-facing cameras do 3696not support autofocus, the API callbacks must still be “faked” as described.</p> 3697 3698<p>Device implementations MUST recognize and honor each parameter name defined as 3699a constant on the android.hardware.Camera.Parameters class, if the underlying 3700hardware supports the feature. If the device hardware does not support a 3701feature, the API must behave as documented. Conversely, device implementations 3702MUST NOT honor or recognize string constants passed to the 3703android.hardware.Camera.setParameters() method other than those documented as 3704constants on the android.hardware.Camera.Parameters. That is, device 3705implementations MUST support all standard Camera parameters if the hardware 3706allows, and MUST NOT support custom Camera parameter types. For instance, 3707device implementations that support image capture using high dynamic range 3708(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> 3709 3710<p>Because not all device implementations can fully support all the features of 3711the android.hardware.camera2 API, device implementations MUST report the proper 3712level of support with the android.info.supportedHardwareLevel property as 3713described 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> 3714 3715<p>Device implementations MUST also declare its Individual camera capabilities of 3716android.hardware.camera2 via the android.request.availableCapabilities property 3717and 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> 3718 3719<p>Device implementations MUST broadcast the Camera.ACTION_NEW_PICTURE intent 3720whenever a new picture is taken by the camera and the entry of the picture has 3721been added to the media store.</p> 3722 3723<p>Device implementations MUST broadcast the Camera.ACTION_NEW_VIDEO intent 3724whenever a new video is recorded by the camera and the entry of the picture has 3725been added to the media store.</p> 3726 3727<h3 id="7_5_5_camera_orientation">7.5.5. Camera Orientation</h3> 3728 3729 3730<p>Both front- and rear-facing cameras, if present, MUST be oriented so that the 3731long dimension of the camera aligns with the screen’s long dimension. That is, 3732when the device is held in the landscape orientation, cameras MUST capture 3733images in the landscape orientation. This applies regardless of the device’s 3734natural orientation; that is, it applies to landscape-primary devices as well 3735as portrait-primary devices.</p> 3736 3737<h2 id="7_6_memory_and_storage">7.6. Memory and Storage</h2> 3738 3739 3740<h3 id="7_6_1_minimum_memory_and_storage">7.6.1. Minimum Memory and Storage</h3> 3741 3742<div class="note"> 3743<p>Android Television devices MUST have at least 5GB of non-volatile storage 3744available for application private data.</p> 3745</div> 3746 3747 3748<p>The memory available to the kernel and userspace on device implementations MUST 3749be at least equal or larger than the minimum values specified by the following 3750table. (See <a href="#7_1_1_screen_configuration">section 7.1.1</a> for screen size and density definitions.)</p> 3751<table> 3752 <tr> 3753 <th>Density and screen size</th> 3754 <th>32-bit device</th> 3755 <th>64-bit device</th> 3756 </tr> 3757 <tr> 3758 <td>Android Watch devices (due to smaller screens)</td> 3759 <td>416MB</td> 3760 <td>Not applicable</td> 3761 </tr> 3762 <tr> 3763 <td><ul> 3764 <li class="table_list">280dpi or lower on small/normal screens</li> 3765 <li class="table_list">mdpi or lower on large screens</li> 3766 <li class="table_list">ldpi or lower on extra large screens</li> 3767 </ul></td> 3768 <td>424MB</td> 3769 <td>704MB</td> 3770 </tr> 3771 <tr> 3772 <td><ul> 3773 <li class="table_list">xhdpi or higher on small/normal screens</li> 3774 <li class="table_list">hdpi or higher on large screens</li> 3775 <li class="table_list">mdpi or higher on extra large screens</li></ul></td> 3776 <td>512MB</td> 3777 <td>832MB</td> 3778 </tr> 3779 <tr> 3780 <td><ul> 3781 <li class="table_list">400dpi or higher on small/normal screens</li> 3782 <li class="table_list">xhdpi or higher on large screens</li> 3783 <li class="table_list">tvdpi or higher on extra large screens</li></ul></td> 3784 <td>896MB</td> 3785 <td>1280MB</td> 3786 </tr> 3787 <tr> 3788 <td><ul> 3789 <li class="table_list">560dpi or higher on small/normal screens</li> 3790 <li class="table_list">400dpi or higher on large screens</li> 3791 <li class="table_list">xhdpi or higher on extra large screens</li></ul></td> 3792 <td>1344MB</td> 3793 <td>1824MB</td> 3794 </tr> 3795</table> 3796 3797 3798<p>The minimum memory values MUST be in addition to any memory space already 3799dedicated to hardware components such as radio, video, and so on that is not 3800under the kernel’s control.</p> 3801 3802<p>Device implementations with less than 512MB of memory available to the kernel 3803and userspace, unless an Android Watch, MUST return the value "true" for 3804ActivityManager.isLowRamDevice().</p> 3805 3806<p>Android Television devices MUST have at least 5GB and other device 3807implementations MUST have at least 1.5GB of non-volatile storage available for 3808application private data. That is, the /data partition MUST be at least 5GB for 3809Android Television devices and at least 1.5GB for other device implementations. 3810Device implementations that run Android are <strong>very strongly encouraged</strong> to have at least 3GB of non-volatile storage for application private data so 3811they will be able to upgrade to the future platform releases.</p> 3812 3813<p>The Android APIs include a Download Manager that applications MAY use to 3814download 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 3815downloading individual files of at least 100MB in size to the default “cache" 3816location.</p> 3817 3818<h3 id="7_6_2_application_shared_storage">7.6.2. Application Shared Storage</h3> 3819 3820 3821<p>Device implementations MUST offer shared storage for applications also often 3822referred as “shared external storage”. </p> 3823 3824<p>Device implementations MUST be configured with shared storage mounted by 3825default, “out of the box”. If the shared storage is not mounted on the Linux 3826path /sdcard, then the device MUST include a Linux symbolic link from /sdcard 3827to the actual mount point.</p> 3828 3829<p>Device implementations MAY have hardware for user-accessible removable storage, 3830such as a Secure Digital (SD) card slot. If this slot is used to satisfy the 3831shared storage requirement, the device implementation:</p> 3832 3833<ul> 3834 <li>MUST implement a toast or pop-up user interface warning the user when there is 3835no SD card.</li> 3836 <li>MUST include a FAT-formatted SD card 1GB in size or larger OR show on the box 3837and other material available at time of purchase that the SD card has to be 3838separately purchased.</li> 3839 <li>MUST mount the SD card by default.</li> 3840</ul> 3841 3842<p>Alternatively, device implementations MAY allocate internal (non-removable) 3843storage as shared storage for apps as included in the upstream Android Open 3844Source Project; device implementations SHOULD use this configuration and 3845software implementation. If a device implementation uses internal 3846(non-removable) storage to satisfy the shared storage requirement, that storage 3847MUST be 1GB in size or larger and mounted on /sdcard (or /sdcard MUST be a 3848symbolic link to the physical location if it is mounted elsewhere).</p> 3849 3850<p>Device implementations MUST enforce as documented the 3851android.permission.WRITE_EXTERNAL_STORAGE permission on this shared storage. 3852Shared storage MUST otherwise be writable by any application that obtains that 3853permission.</p> 3854 3855<p>Device implementations that include multiple shared storage paths (such as both 3856an SD card slot and shared internal storage) MUST NOT allow Android 3857applications to write to the secondary external storage, except for their 3858package-specific directories on the secondary external storage, but SHOULD 3859expose content from both storage paths transparently through Android’s media 3860scanner service and android.provider.MediaStore.</p> 3861 3862<p>Regardless of the form of shared storage used, if the device implementation 3863has a USB port with USB peripheral mode support, it MUST provide some mechanism 3864to access the contents of shared storage from a host computer. Device 3865implementations MAY use USB mass storage, but SHOULD use Media Transfer Protocol 3866to satisfy this requirement. If the device implementation supports Media 3867Transfer Protocol, it:</p> 3868 3869<ul> 3870 <li>SHOULD be compatible with the reference Android MTP host, Android File Transfer 3871[<a href="http://www.android.com/filetransfer">Resources, 96</a>].</li> 3872 <li>SHOULD report a USB device class of 0x00.</li> 3873 <li>SHOULD report a USB interface name of 'MTP'.</li> 3874</ul> 3875 3876<h2 id="7_7_usb">7.7. USB</h2> 3877 3878 3879<p>Device implementations SHOULD support USB peripheral mode and SHOULD support 3880USB host mode.</p> 3881 3882<p>If a device implementation includes a USB port supporting peripheral mode:</p> 3883 3884<ul> 3885 <li>The port MUST be connectable to a USB host that has a standard type-A or type 3886-C USB port.</li> 3887 <li>The port SHOULD use micro-A, micro-AB or type-C USB form factor. Existing and 3888new 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> 3889 <li>The port SHOULD be centered in the middle of an edge. Device implementations 3890SHOULD either locate the port on the bottom of the device (according to natural 3891orientation) or enable software screen rotation for all apps (including home 3892screen), so that the display draws correctly when the device is oriented with 3893the 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> 3894 <li>It MUST allow a USB host connected with the Android device to access the 3895contents of the shared storage volume using either USB mass storage or Media 3896Transfer Protocol.</li> 3897 <li>It SHOULD implement the Android Open Accessory (AOA) API and specification as 3898documented in the Android SDK documentation, and if it is an Android Handheld 3899device it MUST implement the AOA API. Device implementations implementing the 3900AOA specification: 3901 <ul> 3902 <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> 3903 <li>MUST implement the USB audio class as documented in the Android SDK 3904documentation [<a href="http://developer.android.com/reference/android/hardware/usb/UsbConstants.html#USB_CLASS_AUDIO">Resources, 98</a>].</li> 3905 </ul></li> 3906 <li>It SHOULD implement support to draw 1.5 A current during HS chirp and traffic 3907as 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> 3908 <li>The value of iSerialNumber in USB standard device descriptor MUST be equal to 3909the value of android.os.Build.SERIAL.</li> 3910</ul> 3911 3912<p>If a device implementation includes a USB port supporting host mode, it:</p> 3913 3914<ul> 3915 <li>SHOULD use a type-C USB port, if the device implementation supports USB 3.1.</li> 3916 <li>MAY use a non-standard port form factor, but if so MUST ship with a cable or 3917cables adapting the port to a standard type-A or type-C USB port.</li> 3918 <li>MAY use a micro-AB USB port, but if so SHOULD ship with a cable or cables 3919adapting the port to a standard type-A or type-C USB port.</li> 3920 <li>is <strong>very strongly RECOMMENDED</strong> to implement the USB audio class as documented in the Android SDK 3921documentation [<a href="http://developer.android.com/reference/android/hardware/usb/UsbConstants.html#USB_CLASS_AUDIO">Resources, 98</a>].</li> 3922 <li>MUST implement the Android USB host API as documented in the Android SDK, and 3923MUST 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> 3924 <li>SHOULD support the Charging Downstream Port output current range of 1.5 A ~ 5 A 3925as 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> 3926</ul> 3927 3928<h2 id="7_8_audio">7.8. Audio</h2> 3929 3930 3931<h3 id="7_8_1_microphone">7.8.1. Microphone</h3> 3932 3933<div class="note"> 3934<p>Android Handheld, Watch, and Automotive implementations MUST include a 3935microphone.</p> 3936</div> 3937 3938 3939<p>Device implementations MAY omit a microphone. However, if a device 3940implementation omits a microphone, it MUST NOT report the 3941android.hardware.microphone feature constant, and MUST implement the audio 3942recording API at least as no-ops, per <a href="#7_hardware_compatibility">section 7</a>. Conversely, device implementations that do possess a microphone:</p> 3943 3944<ul> 3945 <li>MUST report the android.hardware.microphone feature constant 3946 <li>MUST meet the audio recording requirements in <a href="#5_4_audio_recording">section 5.4</a> 3947 <li>MUST meet the audio latency requirements in <a href="#5_6_audio_latency">section 5.6</a> 3948</ul> 3949 3950<h3 id="7_8_2_audio_output">7.8.2. Audio Output</h3> 3951 3952<div class="note"> 3953<p>Android Watch devices MAY include an audio output.</p> 3954</div> 3955 3956<p>Device implementations including a speaker or with an audio/multimedia output 3957port for an audio output peripheral as a headset or an external speaker:</p> 3958 3959<ul> 3960 <li>MUST report the android.hardware.audio.output feature constant.</li> 3961 <li>MUST meet the audio playback requirements in <a href="#5_5_audio_playback">section 5.5</a>.</li> 3962 <li>MUST meet the audio latency requirements in <a href="#5_6_audio_latency">section 5.6</a>.</li> 3963</ul> 3964 3965<p>Conversely, if a device implementation does not include a speaker or audio 3966output port, it MUST NOT report the android.hardware.audio output feature, and 3967MUST implement the Audio Output related APIs as no-ops at least. </p> 3968 3969<p>Android Watch device implementation MAY but SHOULD NOT have audio output, but 3970other types of Android device implementations MUST have an audio output and 3971declare android.hardware.audio.output.</p> 3972 3973<h4 id="7_8_2_1_analog_audio_ports">7.8.2.1. Analog Audio Ports</h4> 3974 3975 3976<p>In order to be compatible with the headsets and other audio accessories using 3977the 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 3978one of the audio port(s) SHOULD be a 4 conductor 3.5mm audio jack. If a device 3979implementation has a 4 conductor 3.5mm audio jack, it:</p> 3980 3981<ul> 3982 <li>MUST support audio playback to stereo headphones and stereo headsets with a 3983microphone, and SHOULD support audio recording from stereo headsets with a 3984microphone.</li> 3985 <li>MUST support TRRS audio plugs with the CTIA pin-out order, and SHOULD support 3986audio plugs with the OMTP pin-out order.</li> 3987 <li>MUST support the detection of microphone on the plugged in audio accessory, if 3988the device implementation supports a microphone, and broadcast the 3989android.intent.action.HEADSET_PLUG with the extra value microphone set as 1.</li> 3990 <li>SHOULD support the detection and mapping to the keycodes for the following 3 3991ranges of equivalent impedance between the microphone and ground conductors on 3992the audio plug: 3993 <ul> 3994 <li><strong>70 ohm or less</strong>: KEYCODE_HEADSETHOOK</li> 3995 <li><strong>210-290 Ohm</strong>:<strong> </strong>KEYCODE_VOLUME_UP</li> 3996 <li><strong>360-680 Ohm</strong>: KEYCODE_VOLUME_DOWN</li> 3997 </ul></li> 3998 <li>SHOULD support the detection and mapping to the keycode for the following range 3999of equivalent impedance between the microphone and ground conductors on the 4000audio plug: 4001 <ul> 4002 <li><strong>110-180 Ohm: </strong>KEYCODE_VOICE_ASSIST</li> 4003 </ul></li> 4004 <li>MUST trigger ACTION_HEADSET_PLUG upon a plug insert, but only after all 4005contacts on plug are touching their relevant segments on the jack.</li> 4006 <li>MUST be capable of driving at least 150mV +/- 10% of output voltage on a 32 Ohm 4007speaker impedance.</li> 4008 <li>MUST have a microphone bias voltage between 1.8V ~ 2.9V.</li> 4009</ul> 4010 4011<h1 id="8_performance_compatibility">8. Performance Compatibility</h1> 4012 4013 4014<p>Some minimum performance criterias are critical to the user experience and 4015impacts the baseline assumptions developers would have when developing an app. 4016Android Watch devices SHOULD and other type of device implementations MUST meet 4017the following criteria:</p> 4018 4019<h2 id="8_1_user_experience_consistency">8.1. User Experience Consistency</h2> 4020 4021 4022<p>Device implementations MUST provide a smooth user interface by ensuring a 4023consistent frame rate and response times for applications and games. Device 4024implementations MUST meet the following requirements: </p> 4025 4026<ul> 4027 <li><strong>Consistent frame latency</strong>. Inconsistent frame latency or a delay to render frames MUST NOT happen more 4028often than 5 frames in a second, and SHOULD be below 1 frames in a second.</li> 4029 <li><strong>User interface latency</strong>. Device implementations MUST ensure low latency user experience by scrolling a 4030list of 10K list entries as defined by the Android Compatibility Test Suite 4031(CTS) in less than 36 secs.</li> 4032 <li><strong>Task switching</strong>. When multiple applications have been launched, re-launching an already-running 4033application after it has been launched MUST take less than 1 second.</li> 4034</ul> 4035 4036<h2 id="8_2_file_i_o_access_performance">8.2. File I/O Access Performance</h2> 4037 4038 4039<p>Device implementations MUST ensure internal storage file access performance consistency for read 4040and write operations. </p> 4041 4042<ul> 4043 <li><strong>Sequential write</strong>. Device implementations MUST ensure a sequential write performance of at least 5MB/s 4044for a 256MB file using 10MB write buffer.</li> 4045 <li><strong>Random write</strong>. Device implementations MUST ensure a random write performance of at least 0.5MB/s for a 4046256MB file using 4KB write buffer.</li> 4047 <li><strong>Sequential read</strong>. Device implementations MUST ensure a sequential read performance of at least 15MB/s for 4048a 256MB file using 10MB write buffer.</li> 4049 <li><strong>Random read</strong>. Device implementations MUST ensure a random read performance of at least 3.5MB/s for a 4050256MB file using 4KB write buffer.</li> 4051</ul> 4052 4053<h1 id="9_security_model_compatibility">9. Security Model Compatibility</h1> 4054 4055 4056<p>Device implementations MUST implement a security model consistent with the 4057Android platform security model as defined in Security and Permissions 4058reference 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 4059installation of self-signed applications without requiring any additional 4060permissions/certificates from any third parties/authorities. Specifically, 4061compatible devices MUST support the security mechanisms described in the follow 4062subsections.</p> 4063 4064<h2 id="9_1_permissions">9.1. Permissions</h2> 4065 4066 4067<p>Device implementations MUST support the Android permissions model as defined in 4068the 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 4069described in the SDK documentation; no permissions may be omitted, altered, or 4070ignored. Implementations MAY add additional permissions, provided the new 4071permission ID strings are not in the android.* namespace.</p> 4072 4073<h2 id="9_2_uid_and_process_isolation">9.2. UID and Process Isolation</h2> 4074 4075 4076<p>Device implementations MUST support the Android application sandbox model, in 4077which each application runs as a unique Unixstyle UID and in a separate 4078process. Device implementations MUST support running multiple applications as 4079the same Linux user ID, provided that the applications are properly signed and 4080constructed, as defined in the Security and Permissions reference [<a href="http://developer.android.com/guide/topics/security/permissions.html">Resources, 102</a>].</p> 4081 4082<h2 id="9_3_filesystem_permissions">9.3. Filesystem Permissions</h2> 4083 4084 4085<p>Device implementations MUST support the Android file access permissions model 4086as defined in the Security and Permissions reference [<a href="http://developer.android.com/guide/topics/security/permissions.html">Resources, 102</a>].</p> 4087 4088<h2 id="9_4_alternate_execution_environments">9.4. Alternate Execution Environments</h2> 4089 4090 4091<p>Device implementations MAY include runtime environments that execute 4092applications using some other software or technology than the Dalvik Executable 4093Format or native code. However, such alternate execution environments MUST NOT 4094compromise the Android security model or the security of installed Android 4095applications, as described in this section.</p> 4096 4097<p>Alternate runtimes MUST themselves be Android applications, and abide by the 4098standard Android security model, as described elsewhere in <a href="#9_security_model_compatibility">section 9</a>.</p> 4099 4100<p>Alternate runtimes MUST NOT be granted access to resources protected by 4101permissions not requested in the runtime’s AndroidManifest.xml file via the 4102<uses-permission> mechanism.</p> 4103 4104<p>Alternate runtimes MUST NOT permit applications to make use of features 4105protected by Android permissions restricted to system applications.</p> 4106 4107<p>Alternate runtimes MUST abide by the Android sandbox model. Specifically, 4108alternate runtimes:</p> 4109 4110<ul> 4111 <li>SHOULD install apps via the PackageManager into separate Android sandboxes ( 4112Linux user IDs, etc.).</li> 4113 <li>MAY provide a single Android sandbox shared by all applications using the 4114alternate runtime.</li> 4115 <li>and installed applications using an alternate runtime, MUST NOT reuse the 4116sandbox of any other app installed on the device, except through the standard 4117Android mechanisms of shared user ID and signing certificate.</li> 4118 <li>MUST NOT launch with, grant, or be granted access to the sandboxes 4119corresponding to other Android applications.</li> 4120 <li>MUST NOT be launched with, be granted, or grant to other applications any 4121privileges of the superuser (root), or of any other user ID.</li> 4122</ul> 4123 4124<p>The .apk files of alternate runtimes MAY be included in the system image of a 4125device implementation, but MUST be signed with a key distinct from the key used 4126to sign other applications included with the device implementation.</p> 4127 4128<p>When installing applications, alternate runtimes MUST obtain user consent for 4129the Android permissions used by the application. If an application needs to 4130make use of a device resource for which there is a corresponding Android 4131permission (such as Camera, GPS, etc.), the alternate runtime MUST inform the 4132user that the application will be able to access that resource. If the runtime 4133environment does not record application capabilities in this manner, the 4134runtime environment MUST list all permissions held by the runtime itself when 4135installing any application using that runtime.</p> 4136 4137<h2 id="9_5_multi-user_support">9.5. Multi-User Support</h2> 4138 4139<div class="note"> 4140<p>This feature is optional for all device types.</p> 4141</div> 4142 4143 4144<p>Android includes support for multiple users and provides support for full user 4145isolation [<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 4146the following requirements related to multi-user support [<a href="http://source.android.com/devices/storage/">Resources, 104</a>]:</p> 4147 4148<ul> 4149 <li>Device implementations that do not declare the android.hardware.telephony 4150feature flag MUST support restricted profiles, a feature that allows device 4151owners to manage additional users and their capabilities on the device. With 4152restricted profiles, device owners can quickly set up separate environments for 4153additional users to work in, with the ability to manage finer-grained 4154restrictions in the apps that are available in those environments.</li> 4155 <li>Conversely device implementations that declare the android.hardware.telephony 4156feature flag MUST NOT support restricted profiles but MUST align with the AOSP 4157implementation of controls to enable /disable other users from accessing the 4158voice calls and SMS.</li> 4159 <li>Device implementations MUST, for each user, implement a security model 4160consistent with the Android platform security model as defined in Security and 4161Permissions reference document in the APIs [<a href="http://developer.android.com/guide/topics/security/permissions.html">Resources, 102</a>].</li> 4162 <li>Device implementations MAY support creating users and managed profiles via the 4163android.app.admin.DevicePolicyManager APIs, and if supported, MUST declare the 4164platform feature flag android.software.managed_users. 4165 <li>Device implementations that declare the feature flag 4166android.software.managed_users MUST use the upstream AOSP icon badge to 4167represent the managed applications and other badge UI elements like Recents & 4168Notifications.</li> 4169 <li>Each user instance on an Android device MUST have separate and isolated 4170external storage directories. Device implementations MAY store multiple users' 4171data on the same volume or filesystem. However, the device implementation MUST 4172ensure that applications owned by and running on behalf a given user cannot 4173list, read, or write to data owned by any other user. Note that removable 4174media, such as SD card slots, can allow one user to access another’s data by 4175means of a host PC. For this reason, device implementations that use removable 4176media for the external storage APIs MUST encrypt the contents of the SD card if 4177multiuser is enabled using a key stored only on non-removable media accessible 4178only to the system. As this will make the media unreadable by a host PC, device 4179implementations will be required to switch to MTP or a similar system to 4180provide host PCs with access to the current user’s data. Accordingly, device 4181implementations MAY but SHOULD NOT enable multi-user if they use removable 4182media [<a href="http://developer.android.com/reference/android/os/Environment.html">Resources, 105</a>] for primary external storage.</li> 4183</ul> 4184 4185<h2 id="9_6_premium_sms_warning">9.6. Premium SMS Warning</h2> 4186 4187 4188<p>Android includes support for warning users of any outgoing premium SMS message 4189[<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 4190carrier that may incur a charge to the user. Device implementations that 4191declare support for android.hardware.telephony MUST warn users before sending a 4192SMS message to numbers identified by regular expressions defined in 4193/data/misc/sms/codes.xml file in the device. The upstream Android Open Source 4194Project provides an implementation that satisfies this requirement.</p> 4195 4196<h2 id="9_7_kernel_security_features">9.7. Kernel Security Features</h2> 4197 4198 4199<p>The Android Sandbox includes features that can use the Security-Enhanced Linux 4200(SELinux) mandatory access control (MAC) system and other security features in 4201the Linux kernel. SELinux or any other security features, if implemented below 4202the Android framework:</p> 4203 4204<ul> 4205 <li>MUST maintain compatibility with existing applications.</li> 4206 <li>MUST NOT have a visible user interface when a security violation is detected 4207and successfully blocked, but MAY have a visible user interface when an 4208unblocked security violation occurs resulting in a successful exploit.</li> 4209 <li>SHOULD NOT be user or developer configurable.</li> 4210</ul> 4211 4212<p>If any API for configuration of policy is exposed to an application that can 4213affect another application (such as a Device Administration API), the API MUST 4214NOT allow configurations that break compatibility.</p> 4215 4216<p>Devices MUST implement SELinux or an equivalent mandatory access control system 4217if using a kernel other than Linux and meet the following requirements, which 4218are satisfied by the reference implementation in the upstream Android Open 4219Source Project.</p> 4220 4221<p>Device implementations:</p> 4222 4223<ul> 4224 <li>MUST support a SELinux policy that allows the SELinux mode to be set on a 4225per-domain basis, and MUST configure all domains in enforcing mode. No 4226permissive mode domains are allowed, including domains specific to a 4227device/vendor.</li> 4228 <li>SHOULD load policy from /sepolicy file on the device.</li> 4229 <li>MUST NOT modify, omit, or replace the neverallow rules present within the 4230sepolicy file provided in the upstream Android Open Source Project (AOSP) and 4231the policy MUST compile with all neverallow present, for both AOSP SELinux 4232domains as well as device/vendor specific domains.</li> 4233 <li>MUST support dynamic updates of the SELinux policy file without requiring a 4234system image update.</li> 4235</ul> 4236 4237<p>Device implementations SHOULD retain the default SELinux policy provided in the 4238upstream Android Open Source Project, until they have first audited their 4239additions to the SELinux policy. Device implementations MUST be compatible with 4240the upstream Android Open Source Project.</p> 4241 4242<h2 id="9_8_privacy">9.8. Privacy</h2> 4243 4244<p>If the device implements functionality in the system that captures the contents 4245displayed on the screen and/or records the audio stream played on the device, 4246it MUST continuously notify the user whenever this functionality is enabled and 4247actively capturing/recording.</p> 4248 4249<p>If a device implementation has a mechanism that routes network data traffic 4250through a proxy server or VPN gateway by default (for example, preloading a VPN 4251service with android.permission.CONTROL_VPN granted), the device implementation 4252MUST ask for the user's consent before enabling that mechanism.</p> 4253 4254<h2 id="9_9_full-disk_encryption">9.9. Full-Disk Encryption</h2> 4255 4256<div class="note"> 4257<p>Optional for Android device implementations without a lock screen.</p> 4258</div> 4259 4260 4261<p>If the device implementation supports a lock screen with PIN (numeric) or 4262PASSWORD (alphanumeric), the device MUST support full-disk encryption of the 4263application private data (/data partition), as well 4264as the SD card partition if it is a permanent, non-removable part of the device 4265[<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 4266be enabled all the time after the user has completed the out-of-box experience. 4267While this requirement is stated as SHOULD for this version of the Android 4268platform, it is <strong>very strongly RECOMMENDED</strong> as we expect this to change to MUST in the future versions of Android. 4269Encryption MUST use AES with a key of 128-bits (or greater) and a mode designed 4270for storage (for example, AES-XTS, AES-CBC-ESSIV). The encryption key MUST NOT 4271be written to storage at any time without being encrypted. Other than when in 4272active use, the encryption key SHOULD be AES encrypted with the lockscreen 4273passcode stretched using a slow stretching algorithm (e.g. PBKDF2 or scrypt). 4274If the user has not specified a lockscreen passcode or has disabled use of the 4275passcode for encryption, the system SHOULD use a default passcode to wrap the 4276encryption key. If the device provides a hardware-backed keystore, the password 4277stretching algorithm MUST be cryptographically bound to that keystore. The 4278encryption key MUST NOT be sent off the device (even when wrapped with the user 4279passcode and/or hardware bound key). The upstream Android Open Source project 4280provides a preferred implementation of this feature based on the linux kernel 4281feature dm-crypt.</p> 4282 4283<h2 id="9_10_verified_boot">9.10. Verified Boot</h2> 4284 4285<p> 4286Verified boot is a feature that guarantees the integrity of the device software. 4287If a device implementation supports the feature, it MUST: 4288<ul> 4289<li>Declare the platform feature flag android.software.verified_boot</li> 4290<li>Perform verification on every boot sequence</li> 4291<li>Start verification from a hardware key that is the root of trust, and go 4292all the way up to the system partition</li> 4293<li>Implement each stage of verification to check the integrity and authenticity 4294of all the bytes in the next stage before executing the code in the next stage</li> 4295<li>Use verification algorithms as strong as current recommendations 4296from NIST for hashing algorithms (SHA-256) and public key sizes (RSA-2048)</li> 4297</ul> 4298</p> 4299 4300<p>Device implementations SHOULD support verified boot for device integrity. 4301While this requirement is SHOULD for this version of the Android platform, 4302it is <strong>strongly RECOMMENDED</strong> as we expect this to change to MUST 4303in future versions of Android. The upstream Android Open Source Project provides 4304a preferred implementation of this feature based on the linux kernel feature dm-verity. 4305</p> 4306 4307<h1 id="10_software_compatibility_testing">10. Software Compatibility Testing</h1> 4308 4309 4310<p>Device implementations MUST pass all tests described in this section.</p> 4311 4312<p>However, note that no software test package is fully comprehensive. For this 4313reason, device implementers are <strong>very strongly encouraged</strong> to make the minimum number of changes as possible to the reference and 4314preferred implementation of Android available from the Android Open Source 4315Project. This will minimize the risk of introducing bugs that create 4316incompatibilities requiring rework and potential device updates.</p> 4317 4318<h2 id="10_1_compatibility_test_suite">10.1. Compatibility Test Suite</h2> 4319 4320 4321<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 4322software on the device. Additionally, device implementers SHOULD use the 4323reference implementation in the Android Open Source tree as much as possible, 4324and MUST ensure compatibility in cases of ambiguity in CTS and for any 4325reimplementations of parts of the reference source code.</p> 4326 4327<p>The CTS is designed to be run on an actual device. Like any software, the CTS 4328may itself contain bugs. The CTS will be versioned independently of this 4329Compatibility Definition, and multiple revisions of the CTS may be released for 4330Android ANDROID_VERSION. Device implementations MUST pass the latest CTS version available 4331at the time the device software is completed.</p> 4332 4333<h2 id="10_2_cts_verifier">10.2. CTS Verifier</h2> 4334 4335 4336<p>Device implementations MUST correctly execute all applicable cases in the CTS 4337Verifier. The CTS Verifier is included with the Compatibility Test Suite, and 4338is intended to be run by a human operator to test functionality that cannot be 4339tested by an automated system, such as correct functioning of a camera and 4340sensors.</p> 4341 4342<p>The CTS Verifier has tests for many kinds of hardware, including some hardware 4343that is optional. Device implementations MUST pass all tests for hardware that 4344they possess; for instance, if a device possesses an accelerometer, it MUST 4345correctly execute the Accelerometer test case in the CTS Verifier. Test cases 4346for features noted as optional by this Compatibility Definition Document MAY be 4347skipped or omitted.</p> 4348 4349<p>Every device and every build MUST correctly run the CTS Verifier, as noted 4350above. However, since many builds are very similar, device implementers are not 4351expected to explicitly run the CTS Verifier on builds that differ only in 4352trivial ways. Specifically, device implementations that differ from an 4353implementation that has passed the CTS Verifier only by the set of included 4354locales, branding, etc. MAY omit the CTS Verifier test.</p> 4355 4356<h1 id="11_updatable_software">11. Updatable Software</h1> 4357 4358 4359<p>Device implementations MUST include a mechanism to replace the entirety of the 4360system software. The mechanism need not perform “live” upgrades—that is, a 4361device restart MAY be required.</p> 4362 4363<p>Any method can be used, provided that it can replace the entirety of the 4364software preinstalled on the device. For instance, any of the following 4365approaches will satisfy this requirement:</p> 4366 4367<ul> 4368 <li>“Over-the-air (OTA)” downloads with offline update via reboot</li> 4369 <li>“Tethered” updates over USB from a host PC</li> 4370 <li>“Offline” updates via a reboot and update from a file on removable storage</li> 4371</ul> 4372 4373<p>However, if the device implementation includes support for an unmetered data 4374connection such as 802.11 or Bluetooth PAN (Personal Area Network) profile:</p> 4375 4376<ul> 4377<li>Android Automotive implementations SHOULD support OTA downloads with offline 4378update via reboot.</li> 4379<li>All other device implementations MUST support OTA downloads with offline 4380update via reboot.</li> 4381</ul> 4382 4383<p>The update mechanism used MUST support updates without wiping user data. That 4384is, the update mechanism MUST preserve application private data and application 4385shared data. Note that the upstream Android software includes an update 4386mechanism that satisfies this requirement.</p> 4387 4388<p>For device implementations that are launching with Android ANDROID_VERSION and later, the 4389update mechanism SHOULD support verifying that the system image is binary 4390identical to expected result following an OTA. The block-based OTA 4391implementation in the upstream Android Open Source Project, added since Android 43925.1, satisfies this requirement.</p> 4393 4394<p>If an error is found in a device implementation after it has been released but 4395within its reasonable product lifetime that is determined in consultation with 4396the Android Compatibility Team to affect the compatibility of third-party 4397applications, the device implementer MUST correct the error via a software 4398update available that can be applied per the mechanism just described.</p> 4399 4400<h1 id="12_document_changelog">12. Document Changelog</h1> 4401 4402 4403<p>The following table contains a summary of the changes to the Compatibility 4404Definition in this release. </p> 4405<table> 4406 <tr> 4407 <th>Section</th> 4408 <th>Summary of change</th> 4409 </tr> 4410 <tr> 4411 <td>2. Device Types</td> 4412 <td>Added definition for Android automotive implementation.</td> 4413 </tr> 4414 <tr> 4415 <td>2.1 Device Configurations</td> 4416 <td>Added column for Android automotive implementation.</td> 4417 </tr> 4418 <tr> 4419 <td>3.3.2. 32-bit ARM Native Code Compatibility</td> 4420 <td>New section added.</td> 4421 </tr> 4422 <tr> 4423 <td>3.4.1. WebView Compatibility</td> 4424 <td>Updated webview user agent string requirement to accomodate upstream 4425 implementation change.</td> 4426 </tr> 4427 <tr> 4428 <td>3.4.2. Browser compatibility</td> 4429 <td>Added Android automotive implementations as another case that MAY omit a 4430 browser application.</td> 4431 </tr> 4432 <tr> 4433 <td>3.7. Runtime Compatibility</td> 4434 <td>Updated required runtime heap size for smaller screens and added requirement 4435 for the new dpi bucket (280dpi).</td> 4436 </tr> 4437 <tr> 4438 <td>3.8.3. Notifications</td> 4439 <td>Clarified notification requirement for Android Watch, Television and 4440 Automotive implementations.</td> 4441 </tr> 4442 <tr> 4443 <td>3.8.10. Lock Screen Media Control<</td> 4444 <td>Clarified requirement for Android Watch and Automotive implementations.</td> 4445 </tr> 4446 <tr> 4447 <td>3.8.13. Unicode and font</td> 4448 <td>Relaxed Emoji character input method requirement.</td> 4449 </tr> 4450 <tr> 4451 <td>3.9. Device Administration</td> 4452 <td>Clarified condition when the full range of device administration policies 4453 has to be supported.</td> 4454 </tr> 4455 <tr> 4456 <td>3.10. Accessibility</td> 4457 <td>Added Android automotive requirements.</td> 4458 </tr> 4459 <tr> 4460 <td>3.11. Text-To-Speech</td> 4461 <td>Added Android automotive requirements.</td> 4462 </tr> 4463 <tr> 4464 <td>5.1. Media Codecs</td> 4465 <td>Mandated decoding support for codecs reported by CamcorderProfile.</td> 4466 </tr> 4467 <tr> 4468 <td>5.1.3 Video Codecs</td> 4469 <td>Added Android automotive requirements.</td> 4470 </tr> 4471 <tr> 4472 <td>7.1.1.3. Screen Density</td> 4473 <td>Added a new screen dpi (280dpi).</td> 4474 </tr> 4475 <tr> 4476 <td>7.1.5. Legacy Application Compatibility Mode</td> 4477 <td>Added Android automotive requirements.</td> 4478 </tr> 4479 <tr> 4480 <td>7.2 Input Devices</td> 4481 <td>Added general introduction statement.</td> 4482 </tr> 4483 <tr> 4484 <td>7.2.1. Keyboard</td> 4485 <td>Added Android Automotive requirements.</td> 4486 </tr> 4487 <tr> 4488 <td>7.2.3. Navigation Keys</td> 4489 <td>Added Android Automotive requirements.</td> 4490 </tr> 4491 <tr> 4492 <td>7.3.1. Accelerometer</td> 4493 <td>Relaxed requirement for reporting frequency on Android Watch.</td> 4494 </tr> 4495 <tr> 4496 <td>7.3.4. Gyroscope</td> 4497 <td>Relaxed requirement for reporting frequency on Android Watch.</td> 4498 </tr> 4499 <tr> 4500 <td>7.4.3 Bluetooth</td> 4501 <td>Added Android Automotive requirements.</td> 4502 </tr> 4503 <tr> 4504 <td>7.4.4. Near-Field Communications</td> 4505 <td>Clarified condition for when Host Card Emulation is a requirement.</td> 4506 </tr> 4507 <tr> 4508 <td>7.6.1. Minimum Memory and Storage</td> 4509 <td>Updated minimum memory requirements for lower resulution screen devices 4510 and added hard-limit requirement isLowRamDevice().</td> 4511 </tr> 4512 <tr> 4513 <td>7.6.2. Application Shared Storage</td> 4514 <td>Updated requirements when support for host machine access is mandatory.</td> 4515 </tr> 4516 <tr> 4517 <td>7.8.1. Microphone</td> 4518 <td>Added Android Automotive requirements.</td> 4519 </tr> 4520 <tr> 4521 <td>8.2. File I/O Access Performance</td> 4522 <td>Clarified requirements.</td> 4523 </tr> 4524 <tr> 4525 <td>9.8. Privacy</td> 4526 <td>Added privacy requirement for preloaded VPNs.</td> 4527 </tr> 4528 <tr> 4529 <td>9.9. Full-Disk Encryption</td> 4530 <td>Clarified condition when Full-Disk encryption support is mandatory.</td> 4531 </tr> 4532 <tr> 4533 <td>9.10. Verified Boot</td> 4534 <td>Clarified definition of verified boot.</td> 4535 </tr> 4536 <tr> 4537 <td>11. Updatable Software</td> 4538 <td>Clarified the OTA download requirement is allowed but not mandatory for 4539 Android Automotive implementations.</td> 4540 </tr> 4541</table> 4542 4543 4544<h1 id="13_contact_us">13. Contact Us</h1> 4545 4546 4547<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 4548does not cover.</p> 4549 4550<h1 id="14_resources">14. Resources</h1> 4551 4552 4553<p>1. IETF RFC2119 Requirement Levels: <a href="http://www.ietf.org/rfc/rfc2119.txt">http://www.ietf.org/rfc/rfc2119.txt</a></p> 4554 4555<p>2. Android Open Source Project: <a href="http://source.android.com/">http://source.android.com/</a></p> 4556 4557<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> 4558 4559<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> 4560 4561<p>5. API definitions and documentation: <a href="http://developer.android.com/reference/packages.html">http://developer.android.com/reference/packages.html</a></p> 4562 4563<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> 4564 4565<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> 4566 4567<p>8. Android ANDROID_VERSION allowed version strings: <a href="http://source.android.com/compatibility/ANDROID_VERSION/versions.html">http://source.android.com/compatibility/ANDROID_VERSION/versions.html</a></p> 4568 4569<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> 4570 4571<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> 4572 4573<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> 4574 4575<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> 4576 4577<p>13. WebView compatibility: <a href="http://www.chromium.org/">http://www.chromium.org/</a></p> 4578 4579<p>14. HTML5: <a href="http://html.spec.whatwg.org/multipage/">http://html.spec.whatwg.org/multipage/</a></p> 4580 4581<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> 4582 4583<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> 4584 4585<p>17. HTML5/W3C geolocation API: <a href="http://www.w3.org/TR/geolocation-API/">http://www.w3.org/TR/geolocation-API/</a></p> 4586 4587<p>18. HTML5/W3C webstorage API: <a href="http://www.w3.org/TR/webstorage/">http://www.w3.org/TR/webstorage/</a></p> 4588 4589<p>19. HTML5/W3C IndexedDB API: <a href="http://www.w3.org/TR/IndexedDB/">http://www.w3.org/TR/IndexedDB/</a></p> 4590 4591<p>20. Dalvik Executable Format and bytecode specification: available in the 4592Android source code, at dalvik/docs</p> 4593 4594<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> 4595 4596<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> 4597 4598<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> 4599 4600<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> 4601 4602<p>25. Notifications Resources: <a href="https://developer.android.com/design/patterns/notifications.html">https://developer.android.com/design/patterns/notifications.html</a> </p> 4603 4604<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> 4605 4606<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> 4607 4608<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> 4609 4610<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> 4611 4612<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> 4613 4614<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> 4615 4616<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> 4617 4618<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> 4619 4620<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> 4621 4622<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> 4623 4624<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> 4625 4626<p>37. Settings.Secure LOCATION_MODE:</p> 4627 4628<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> 4629 4630<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> 4631 4632<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> 4633 4634<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> 4635 4636<p>41. Android Device Owner App:</p> 4637 4638<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> 4639 4640<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> 4641 4642<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> 4643 4644<p>44. Eyes Free project: <a href="http://code.google.com/p/eyes-free/">http://code.google.com/p/eyes-free</a></p> 4645 4646<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> 4647 4648<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> 4649 4650<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> 4651 4652<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> 4653 4654<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> 4655 4656<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> 4657 4658<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> 4659 4660<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> 4661 4662<p>53. Android android.content.pm.PackageManager class and Hardware Features List:</p> 4663 4664<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> 4665 4666<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> 4667 4668<p>55. ADB: <a href="http://developer.android.com/tools/help/adb.html">http://developer.android.com/tools/help/adb.html</a> </p> 4669 4670<p>56. Dumpsys: <a href="https://source.android.com/devices/input/diagnostics.html">https://source.android.com/devices/input/diagnostics.html</a> </p> 4671 4672<p>57. DDMS: <a href="http://developer.android.com/tools/debugging/ddms.html">http://developer.android.com/tools/debugging/ddms.html</a> </p> 4673 4674<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> 4675 4676<p>59. SysyTrace tool: <a href="http://developer.android.com/tools/help/systrace.html">http://developer.android.com/tools/help/systrace.html</a></p> 4677 4678<p>60. Android Application Development-Related Settings:</p> 4679 4680<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> 4681 4682<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> 4683 4684<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> 4685 4686<p>63. RenderScript: <a href="http://developer.android.com/guide/topics/renderscript/">http://developer.android.com/guide/topics/renderscript/</a></p> 4687 4688<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> 4689 4690<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> 4691 4692<p>66. EGL Extension-EGL_ANDROID_RECORDABLE:</p> 4693 4694<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> 4695 4696<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> 4697 4698<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> 4699 4700<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> 4701 4702<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> 4703 4704<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> 4705 4706<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> 4707 4708<p>73. Android Open Source sensors: <a href="http://source.android.com/devices/sensors/">http://source.android.com/devices/sensors</a></p> 4709 4710<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> 4711 4712<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> 4713 4714<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> 4715 4716<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> 4717 4718<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> 4719 4720<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> 4721 4722<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> 4723 4724<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> 4725 4726<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> 4727 4728<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> 4729 4730<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> 4731 4732<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> 4733 4734<p>86. Android NFC Sharing Settings:</p> 4735 4736<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> 4737 4738<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> 4739 4740<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> 4741 4742<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> 4743 4744<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> 4745 4746<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> 4747 4748<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> 4749 4750<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> 4751 4752<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> 4753 4754<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> 4755 4756<p>96. Android File Transfer: <a href="http://www.android.com/filetransfer">http://www.android.com/filetransfer</a></p> 4757 4758<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> 4759 4760<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> 4761 4762<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> 4763 4764<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> 4765 4766<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> 4767 4768<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> 4769 4770<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> 4771 4772<p>104. External Storage reference: <a href="http://source.android.com/devices/storage">http://source.android.com/devices/storage</a></p> 4773 4774<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> 4775 4776<p>106. SMS Short Code: <a href="http://en.wikipedia.org/wiki/Short_code">http://en.wikipedia.org/wiki/Short_code</a></p> 4777 4778<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> 4779 4780<p>108. Android Compatibility Program Overview: <a href="http://source.android.com/compatibility/index.html">http://source.android.com/compatibility/index.html</a></p> 4781 4782<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> 4783 4784<p>110. WebM project: <a href="http://www.webmproject.org/">http://www.webmproject.org/</a> </p> 4785 4786<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> 4787 4788<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> 4789 4790<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> 4791 4792<p>Many of these resources are derived directly or indirectly from the Android 4793SDK, and will be functionally identical to the information in that SDK’s 4794documentation. In any cases where this Compatibility Definition or the 4795Compatibility Test Suite disagrees with the SDK documentation, the SDK 4796documentation is considered authoritative. Any technical details provided in 4797the references included above are considered by inclusion to be part of this 4798Compatibility Definition.</p> 4799 4800</div> 4801</body> 4802</html> 4803
