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2<head>
3<title>Android ANDROID_VERSION Compatibility Definition</title>
4<link rel="stylesheet" type="text/css" href="android-cdd.css"/>
5</head>
6
7<body>
8
9<h6>Table of Contents</h6>
10
11<div id="toc">
12
13<div id="toc_left">
14
15<p class="toc_h1"><a href="#1_introduction">1. Introduction</a></p>
16
17<p class="toc_h1"><a href="#2_device_types">2. Device Types</a></p>
18
19<p class="toc_h2"><a href="#2_1_device_configurations">2.1 Device Configurations</a></p>
20
21<p class="toc_h1"><a href="#3_software">3. Software</a></p>
22
23<p class="toc_h2"><a href="#3_1_managed_api_compatibility">3.1. Managed API Compatibility</a></p>
24
25<p class="toc_h2"><a href="#3_2_soft_api_compatibility">3.2. Soft API Compatibility</a></p>
26
27<p class="toc_h3"><a href="#3_2_1_permissions">3.2.1. Permissions</a></p>
28
29<p class="toc_h3"><a href="#3_2_2_build_parameters">3.2.2. Build Parameters</a></p>
30
31<p class="toc_h3"><a href="#3_2_3_intent_compatibility">3.2.3. Intent Compatibility</a></p>
32
33<p class="toc_h4"><a href="#3_2_3_1_core_application_intents">3.2.3.1. Core Application Intents</a></p>
34
35<p class="toc_h4"><a href="#3_2_3_2_intent_overrides">3.2.3.2. Intent Overrides</a></p>
36
37<p class="toc_h4"><a href="#3_2_3_3_intent_namespaces">3.2.3.3. Intent Namespaces</a></p>
38
39<p class="toc_h4"><a href="#3_2_3_4_broadcast_intents">3.2.3.4. Broadcast Intents</a></p>
40
41<p class="toc_h4"><a href="#3_2_3_5_default_app_settings">3.2.3.5. Default App Settings</a></p>
42
43<p class="toc_h2"><a href="#3_3_native_api_compatibility">3.3. Native API Compatibility</a></p>
44
45<p class="toc_h3"><a href="#3_3_1_application_binary_interfaces">3.3.1. Application Binary Interfaces</a></p>
46
47<p class="toc_h3"><a href="#3_3_2_32-bit_arm_native_code_compatibility">3.3.2. 32-bit ARM Native Code Compatibility</a></p>
48
49<p class="toc_h2"><a href="#3_4_web_compatibility">3.4. Web Compatibility</a></p>
50
51<p class="toc_h3"><a href="#3_4_1_webview_compatibility">3.4.1. WebView Compatibility</a></p>
52
53<p class="toc_h3"><a href="#3_4_2_browser_compatibility">3.4.2. Browser Compatibility</a></p>
54
55<p class="toc_h2"><a href="#3_5_api_behavioral_compatibility">3.5. API Behavioral Compatibility</a></p>
56
57<p class="toc_h2"><a href="#3_6_api_namespaces">3.6. API Namespaces</a></p>
58
59<p class="toc_h2"><a href="#3_7_runtime_compatibility">3.7. Runtime Compatibility</a></p>
60
61<p class="toc_h2"><a href="#3_8_user_interface_compatibility">3.8. User Interface Compatibility</a></p>
62
63<p class="toc_h3"><a href="#3_8_1_launcher_home_screen">3.8.1. Launcher (Home Screen)</a></p>
64
65<p class="toc_h3"><a href="#3_8_2_widgets">3.8.2. Widgets</a></p>
66
67<p class="toc_h3"><a href="#3_8_3_notifications">3.8.3. Notifications</a></p>
68
69<p class="toc_h3"><a href="#3_8_4_search">3.8.4. Search</a></p>
70
71<p class="toc_h3"><a href="#3_8_5_toasts">3.8.5. Toasts</a></p>
72
73<p class="toc_h3"><a href="#3_8_6_themes">3.8.6. Themes</a></p>
74
75<p class="toc_h3"><a href="#3_8_7_live_wallpapers">3.8.7. Live Wallpapers</a></p>
76
77<p class="toc_h3"><a href="#3_8_8_activity_switching">3.8.8. Activity Switching</a></p>
78
79<p class="toc_h3"><a href="#3_8_9_input_management">3.8.9. Input Management</a></p>
80
81<p class="toc_h3"><a href="#3_8_10_lock_screen_media_control">3.8.10. Lock Screen Media Control</a></p>
82
83<p class="toc_h3"><a href="#3_8_11_dreams">3.8.11. Dreams</a></p>
84
85<p class="toc_h3"><a href="#3_8_12_location">3.8.12. Location</a></p>
86
87<p class="toc_h3"><a href="#3_8_13_unicode_and_font">3.8.13. Unicode and Font</a></p>
88
89
90
91</div>
92
93<div id="toc_right"><br>
94
95
96
97<p class="toc_h2"><a href="#3_9_device_administration">3.9. Device Administration</a></p>
98
99<p class="toc_h2"><a href="#3_10_accessibility">3.10. Accessibility</a></p>
100
101<p class="toc_h2"><a href="#3_11_text-to-speech">3.11. Text-to-Speech</a></p>
102
103<p class="toc_h2"><a href="#3_12_tv_input_framework">3.12. TV Input Framework</a></p>
104
105<p class="toc_h1"><a href="#4_application_packaging_compatibility">4. Application Packaging Compatibility</a></p>
106
107<p class="toc_h1"><a href="#5_multimedia_compatibility">5. Multimedia Compatibility</a></p>
108
109<p class="toc_h2"><a href="#5_1_media_codecs">5.1. Media Codecs</a></p>
110
111<p class="toc_h3"><a href="#5_1_1_audio_codecs">5.1.1. Audio Codecs</a></p>
112
113<p class="toc_h3"><a href="#5_1_2_image_codecs">5.1.2. Image Codecs</a></p>
114
115<p class="toc_h3"><a href="#5_1_3_video_codecs">5.1.3. Video Codecs</a></p>
116
117<p class="toc_h2"><a href="#5_2_video_encoding">5.2. Video Encoding</a></p>
118
119<p class="toc_h2"><a href="#5_3_video_decoding">5.3. Video Decoding</a></p>
120
121<p class="toc_h2"><a href="#5_4_audio_recording">5.4. Audio Recording</a></p>
122
123<p class="toc_h3"><a href="#5_4_1_raw_audio_capture">5.4.1. Raw Audio Capture</a></p>
124
125<p class="toc_h3"><a href="#5_4_2_capture_for_voice_recognition">5.4.2. Capture for Voice Recognition</a></p>
126
127<p class="toc_h3"><a href="#5_4_3_capture_for_rerouting_of_playback">5.4.3. Capture for Rerouting of Playback</a></p>
128
129<p class="toc_h2"><a href="#5_5_audio_playback">5.5. Audio Playback</a></p>
130
131<p class="toc_h3"><a href="#5_5_1_raw_audio_playback">5.5.1. Raw Audio Playback</a></p>
132
133<p class="toc_h3"><a href="#5_5_2_audio_effects">5.5.2. Audio Effects</a></p>
134
135<p class="toc_h3"><a href="#5_5_3_audio_output_volume">5.5.3. Audio Output Volume</a></p>
136
137<p class="toc_h2"><a href="#5_6_audio_latency">5.6. Audio Latency</a></p>
138
139<p class="toc_h2"><a href="#5_7_network_protocols">5.7. Network Protocols</a></p>
140
141<p class="toc_h2"><a href="#5_8_secure_media">5.8. Secure Media</a></p>
142
143<p class="toc_h1"><a href="#6_developer_tools_and_options_compatibility">6. Developer Tools and Options Compatibility</a></p>
144
145<p class="toc_h2"><a href="#6_1_developer_tools">6.1. Developer Tools</a></p>
146
147<p class="toc_h2"><a href="#6_2_developer_options">6.2. Developer Options</a></p>
148
149<p class="toc_h1"><a href="#7_hardware_compatibility">7. Hardware Compatibility</a></p>
150
151<p class="toc_h2"><a href="#7_1_display_and_graphics">7.1. Display and Graphics</a></p>
152
153<p class="toc_h3"><a href="#7_1_1_screen_configuration">7.1.1. Screen Configuration</a></p>
154
155<p class="toc_h4"><a href="#7_1_1_1_screen_size">7.1.1.1. Screen Size</a></p>
156
157<p class="toc_h4"><a href="#7_1_1_2_screen_aspect_ratio">7.1.1.2. Screen Aspect Ratio</a></p>
158
159<p class="toc_h4"><a href="#7_1_1_3_screen_density">7.1.1.3. Screen Density</a></p>
160
161
162</div>
163
164<div style="clear: both; page-break-after:always; height:1px"></div>
165
166
167<div id="toc_left_2">
168
169<p class="toc_h3"><a href="#7_1_2_display_metrics">7.1.2. Display Metrics</a></p>
170
171<p class="toc_h3"><a href="#7_1_3_screen_orientation">7.1.3. Screen Orientation</a></p>
172
173<p class="toc_h3"><a href="#7_1_4_2d_and_3d_graphics_acceleration">7.1.4. 2D and 3D Graphics Acceleration</a></p>
174
175<p class="toc_h3"><a href="#7_1_5_legacy_application_compatibility_mode">7.1.5. Legacy Application Compatibility Mode</a></p>
176
177<p class="toc_h3"><a href="#7_1_6_screen_technology">7.1.6. Screen Technology</a></p>
178
179<p class="toc_h3"><a href="#7_1_7_external_displays">7.1.7. Secondary Displays</a></p>
180
181<p class="toc_h2"><a href="#7_2_input_devices">7.2. Input Devices</a></p>
182
183<p class="toc_h3"><a href="#7_2_1_keyboard">7.2.1. Keyboard</a></p>
184
185<p class="toc_h3"><a href="#7_2_2_non-touch_navigation">7.2.2. Non-touch Navigation</a></p>
186
187<p class="toc_h3"><a href="#7_2_3_navigation_keys">7.2.3. Navigation Keys</a></p>
188
189<p class="toc_h3"><a href="#7_2_4_touchscreen_input">7.2.4. Touchscreen Input</a></p>
190
191<p class="toc_h3"><a href="#7_2_5_fake_touch_input">7.2.5. Fake Touch Input</a></p>
192
193<p class="toc_h3"><a href="#7_2_6_game_controller_support">7.2.6. Game Controller Support</a></p>
194
195<p class="toc_h4"><a href="#7_2_6_1_button_mapping">7.2.6.1. Button Mappings</a></p>
196
197<p class="toc_h3"><a href="#7_2_7_remote_control">7.2.7. Remote Control</a></p>
198
199<p class="toc_h2"><a href="#7_3_sensors">7.3. Sensors</a></p>
200
201<p class="toc_h3"><a href="#7_3_1_accelerometer">7.3.1. Accelerometer</a></p>
202
203<p class="toc_h3"><a href="#7_3_2_magnetometer">7.3.2. Magnetometer</a></p>
204
205<p class="toc_h3"><a href="#7_3_3_gps">7.3.3. GPS</a></p>
206
207<p class="toc_h3"><a href="#7_3_4_gyroscope">7.3.4. Gyroscope</a></p>
208
209<p class="toc_h3"><a href="#7_3_5_barometer">7.3.5. Barometer</a></p>
210
211<p class="toc_h3"><a href="#7_3_6_thermometer">7.3.6. Thermometer</a></p>
212
213<p class="toc_h3"><a href="#7_3_7_photometer">7.3.7. Photometer</a></p>
214
215<p class="toc_h3"><a href="#7_3_8_proximity_sensor">7.3.8. Proximity Sensor</a></p>
216
217<p class="toc_h2"><a href="#7_4_data_connectivity">7.4. Data Connectivity</a></p>
218
219<p class="toc_h3"><a href="#7_4_1_telephony">7.4.1. Telephony</a></p>
220
221<p class="toc_h3"><a href="#7_4_2_ieee_80211_wi-fi">7.4.2. IEEE 802.11 (Wi-Fi)</a></p>
222
223<p class="toc_h4"><a href="#7_4_2_1_wi-fi_direct">7.4.2.1. Wi-Fi Direct</a></p>
224
225<p class="toc_h4"><a href="#7_4_2_2_wi-fi-tunneled-direct-link-setup">7.4.2.2. Wi-Fi Tunneled Direct Link Setup</a></p>
226
227<p class="toc_h3"><a href="#7_4_3_bluetooth">7.4.3. Bluetooth</a></p>
228
229<p class="toc_h3"><a href="#7_4_4_near-field_communications">7.4.4. Near-Field Communications</a></p>
230
231<p class="toc_h3"><a href="#7_4_5_minimum_network_capability">7.4.5. Minimum Network Capability</a></p>
232
233<p class="toc_h3"><a href="#7_4_6_sync_settings">7.4.6. Sync Settings</a></p>
234
235<p class="toc_h2"><a href="#7_5_cameras">7.5. Cameras</a></p>
236
237<p class="toc_h3"><a href="#7_5_1_rear-facing_camera">7.5.1. Rear-Facing Camera</a></p>
238
239<p class="toc_h3"><a href="#7_5_2_front-facing_camera">7.5.2. Front-Facing Camera</a></p>
240
241<p class="toc_h3"><a href="#7_5_3_external_camera">7.5.3. External Camera</a></p>
242
243<p class="toc_h3"><a href="#7_5_4_camera_api_behavior">7.5.4. Camera API Behavior</a></p>
244
245
246
247
248
249</div>
250
251<div id="toc_right_2">
252
253<p class="toc_h3"><a href="#7_5_5_camera_orientation">7.5.5. Camera Orientation</a></p>
254
255<p class="toc_h2"><a href="#7_6_memory_and_storage">7.6. Memory and Storage</a></p>
256
257<p class="toc_h3"><a href="#7_6_1_minimum_memory_and_storage">7.6.1. Minimum Memory and Storage</a></p>
258
259<p class="toc_h3"><a href="#7_6_2_application_shared_storage">7.6.2. Application Shared Storage</a></p>
260
261<p class="toc_h2"><a href="#7_7_usb">7.7. USB</a></p>
262
263<p class="toc_h2"><a href="#7_8_audio">7.8. Audio</a></p>
264
265<p class="toc_h3"><a href="#7_8_1_microphone">7.8.1. Microphone</a></p>
266
267<p class="toc_h3"><a href="#7_8_2_audio_output">7.8.2. Audio Output</a></p>
268
269<p class="toc_h4"><a href="#7_8_2_1_analog_audio_ports">7.8.2.1. Analog Audio Ports</a></p>
270
271<p class="toc_h1"><a href="#8_performance_compatibility">8. Performance Compatibility</a></p>
272
273<p class="toc_h2"><a href="#8_1_user_experience_consistency">8.1. User Experience Consistency</a></p>
274
275<p class="toc_h2"><a href="#8_2_memory_performance">8.2. Memory Performance</a></p>
276
277<p class="toc_h1"><a href="#9_security_model_compatibility">9. Security Model Compatibility</a></p>
278
279<p class="toc_h2"><a href="#9_1_permissions">9.1. Permissions</a></p>
280
281<p class="toc_h2"><a href="#9_2_uid_and_process_isolation">9.2. UID and Process Isolation</a></p>
282
283<p class="toc_h2"><a href="#9_3_filesystem_permissions">9.3. Filesystem Permissions</a></p>
284
285<p class="toc_h2"><a href="#9_4_alternate_execution_environments">9.4. Alternate Execution Environments</a></p>
286
287<p class="toc_h2"><a href="#9_5_multi-user_support">9.5. Multi-User Support</a></p>
288
289<p class="toc_h2"><a href="#9_6_premium_sms_warning">9.6. Premium SMS Warning</a></p>
290
291<p class="toc_h2"><a href="#9_7_kernel_security_features">9.7. Kernel Security Features</a></p>
292
293<p class="toc_h2"><a href="#9_8_privacy">9.8. Privacy</a></p>
294
295<p class="toc_h2"><a href="#9_9_full-disk-encryption">9.9. Full-Disk Encryption</a></p>
296
297<p class="toc_h2"><a href="#9_10_verified_boot">9.10. Verified Boot</a></p>
298
299<p class="toc_h1"><a href="#10_software_compatibility_testing">10. Software Compatibility Testing</a></p>
300
301<p class="toc_h2"><a href="#10_1_compatibility_test_suite">10.1. Compatibility Test Suite</a></p>
302
303<p class="toc_h2"><a href="#10_2_cts_verifier">10.2. CTS Verifier</a></p>
304
305<p class="toc_h1"><a href="#11_updatable_software">11. Updatable Software</a></p>
306
307<p class="toc_h1"><a href="#12_document_changelog">12. Document Changelog</a></p>
308
309<p class="toc_h1"><a href="#13_contact_us">13. Contact Us</a></p>
310
311<p class="toc_h1"><a href="#14_resources">14. Resources</a></p>
312
313</div>
314
315</div>
316
317<div style="clear: both"></div>
318
319<div id="main">
320
321<h1 id="1_introduction">1. Introduction</h1>
322
323
324<p>This document enumerates the requirements that must be met in order for devices
325to be compatible with Android ANDROID_VERSION.</p>
326
327<p>The use of &ldquo;MUST&rdquo;, &ldquo;MUST NOT&rdquo;, &ldquo;REQUIRED&rdquo;, &ldquo;SHALL&rdquo;, &ldquo;SHALL NOT&rdquo;, &ldquo;SHOULD&rdquo;,&ldquo;SHOULD NOT&rdquo;, &ldquo;RECOMMENDED&rdquo;, &ldquo;MAY&rdquo;, and &ldquo;OPTIONAL&rdquo; is per the IETF standard
328defined in RFC2119 [<a href="http://www.ietf.org/rfc/rfc2119.txt">Resources, 1</a>].</p>
329
330<p>As used in this document, a &ldquo;device implementer&rdquo; or &ldquo;implementer&rdquo; is a person
331or organization developing a hardware/software solution running Android ANDROID_VERSION. A
332&ldquo;device implementation&rdquo; or &ldquo;implementation is the hardware/software solution
333so developed.</p>
334
335<p>To be considered compatible with Android ANDROID_VERSION, device implementations MUST meet
336the requirements presented in this Compatibility Definition, including any
337documents incorporated via reference.</p>
338
339<p>Where this definition or the software tests described in <a href="#10_software_compatibility_testing">section 10</a> is silent, ambiguous, or incomplete, it is the responsibility of the device
340implementer to ensure compatibility with existing implementations.</p>
341
342<p>For this reason, the Android Open Source Project [<a href="http://source.android.com/">Resources, 2</a>] is both the reference and preferred implementation of Android. Device
343implementers are strongly encouraged to base their implementations to the
344greatest extent possible on the &ldquo;upstream&rdquo; source code available from the
345Android Open Source Project. While some components can hypothetically be
346replaced with alternate implementations this practice is strongly discouraged,
347as passing the software tests will become substantially more difficult. It is
348the implementer&rsquo;s responsibility to ensure full behavioral compatibility with
349the standard Android implementation, including and beyond the Compatibility
350Test Suite. Finally, note that certain component substitutions and
351modifications are explicitly forbidden by this document.</p>
352
353<p>Many of the resources listed in <a href="#14_resources">section 14</a> are derived directly or indirectly from the Android SDK, and will be
354functionally identical to the information in that SDK&rsquo;s documentation. For any
355case where this Compatibility Definition or the Compatibility Test Suite
356disagrees with the SDK documentation, the SDK documentation is considered
357authoritative. Any technical details provided in the references included in <a href="#14_resources">section 14</a> are considered by inclusion to be part of this Compatibility Definition. </p>
358
359<h1 id="2_device_types">2. Device Types</h1>
360
361
362<p>While the Android Open Source Project has been used in the implementation of a
363variety of device types and form factors, many aspects of the architecture and
364compatibility requirements were optimized for handheld devices. Starting from
365Android 5.0, the Android Open Source Project aims to embrace a wider variety of
366device types as described in this section.</p>
367
368<p><strong>Android Handheld device</strong> refers to an Android device implementation that is typically used by holding
369it in the hand, such as mp3 players, phones, and tablets. Android Handheld
370device implementations:</p>
371
372<ul>
373 <li>MUST have a touchscreen embedded in the device.</li>
374 <li>MUST have a power source that provides mobility, such as a battery.</li>
375</ul>
376
377<p><strong>Android Television device</strong> refers to an Android device implementation that is an entertainment interface
378for consuming digital media, movies, games, apps, and/or live TV for users
379sitting about ten feet away (a &ldquo;lean back&rdquo; or &ldquo;10-foot user interface&rdquo;).
380Android Television devices:</p>
381
382<ul>
383 <li>MUST have an embedded screen OR include a video output port, such as VGA, HDMI,
384or a wireless port for display.</li>
385 <li>MUST declare the features android.software.leanback and
386android.hardware.type.television [<a href="http://developer.android.com/reference/android/content/pm/PackageManager.html#FEATURE_LEANBACK">Resources, 3</a>].</li>
387</ul>
388
389<p><strong>Android Watch device</strong> refers to an Android device implementation intended to be worn on the body,
390perhaps on the wrist, and:</p>
391
392<ul>
393 <li>MUST have a screen with the physical diagonal length in the range from 1.1 to
3942.5 inches.</li>
395 <li>MUST declare the feature android.hardware.type.watch.</li>
396 <li>MUST support uiMode = UI_MODE_TYPE_WATCH [<a href="http://developer.android.com/reference/android/content/res/Configuration.html#UI_MODE_TYPE_WATCH">Resources, 4</a>].</li>
397</ul>
398
399<p><strong>Android Automotive implementation</strong> refers to a vehicle head
400unit running Android as an operating system for part or all of the system and/or
401infotainment functionality. Android Automotive implementations MUST support
402uiMode = UI_MODE_TYPE_CAR [<a href="http://developer.android.com/reference/android/content/res/Configuration.html#UI_MODE_TYPE_CAR">Resources, 111</a>].</p>
403
404<p>All Android device implementations that do not fit into any of the above device
405types still MUST meet all requirements in this document to be Android ANDROID_VERSION
406compatible, unless the requirement is explicitly described to be only
407applicable to a specific Android device type from above.</p>
408
409<h2 id="2_1_device_configurations">2.1 Device Configurations</h2>
410
411
412<p>This is a summary of major differences in hardware configuration by device
413type. (Empty cells denote a &ldquo;MAY&rdquo;). Not all configurations are covered in this
414table; see relevant hardware sections for more detail.</p>
415<table>
416 <tr>
417 <th>Category</th>
418 <th>Feature</th>
419 <th>Section</th>
420 <th>Handheld</th>
421 <th>Television</th>
422 <th>Watch</th>
423 <th>Automotive</th>
424 <th>Other</th>
425 </tr>
426 <tr>
427 <td rowspan="3">Input</td>
428 <td>D-pad</td>
429 <td><a href="#7_2_2_non-touch-navigation">7.2.2. Non-touch Navigation</a></td>
430 <td></td>
431 <td>MUST</td>
432 <td></td>
433 <td></td>
434 <td></td>
435 </tr>
436 <tr>
437 <td>Touchscreen </td>
438 <td><a href="#7_2_4_touchscreen_input">7.2.4. Touchscreen input</a></td>
439 <td>MUST</td>
440 <td></td>
441 <td>MUST</td>
442 <td></td>
443 <td>SHOULD</td>
444 </tr>
445 <tr>
446 <td>Microphone </td>
447 <td><a href="#7_8_1_microphone">7.8.1. Microphone</a></td>
448 <td>MUST</td>
449 <td>SHOULD </td>
450 <td>MUST</td>
451 <td>MUST</td>
452 <td>SHOULD</td>
453 </tr>
454 <tr>
455 <td rowspan="2">Sensors</td>
456 <td>Accelerometer </td>
457 <td><a href="#7_3_1_accelerometer">7.3.1 Accelerometer</a></td>
458 <td>SHOULD</td>
459 <td></td>
460 <td>SHOULD</td>
461 <td></td>
462 <td>SHOULD</td>
463 </tr>
464 <tr>
465 <td>GPS</td>
466 <td><a href="#7_3_3_gps">7.3.3. GPS</a></td>
467 <td>SHOULD</td>
468 <td></td>
469 <td></td>
470 <td>SHOULD</td>
471 <td></td>
472 </tr>
473 <tr>
474 <td rowspan="5">Connectivity</td>
475 <td>Wi-Fi</td>
476 <td><a href="#7_4_2_ieee_802.11">7.4.2. IEEE 802.11</a></td>
477 <td>SHOULD</td>
478 <td> MUST</td>
479 <td></td>
480 <td>SHOULD</td>
481 <td>SHOULD</td>
482 </tr>
483 <tr>
484 <td>Wi-Fi Direct</td>
485 <td><a href="#7_4_2_1_wi-fi-direct">7.4.2.1. Wi-Fi Direct</a></td>
486 <td>SHOULD</td>
487 <td>SHOULD</td>
488 <td></td>
489 <td></td>
490 <td>SHOULD</td>
491 </tr>
492 <tr>
493 <td>Bluetooth</td>
494 <td><a href="#7_4_3_bluetooth">7.4.3. Bluetooth</a></td>
495 <td>SHOULD</td>
496 <td>MUST</td>
497 <td>MUST</td>
498 <td>MUST</td>
499 <td>SHOULD</td>
500 </tr>
501 <tr>
502 <td>Bluetooth Low Energy</td>
503 <td><a href="#7_4_3_bluetooth">7.4.3. Bluetooth</a></td>
504 <td>SHOULD</td>
505 <td>MUST</td>
506 <td>SHOULD</td>
507 <td>SHOULD</td>
508 <td>SHOULD</td>
509 </tr>
510 <tr>
511 <td>USB peripheral/host mode</td>
512 <td><a href="#7_7_usb">7.7. USB</a></td>
513 <td>SHOULD</td>
514 <td></td>
515 <td></td>
516 <td>SHOULD</td>
517 <td>SHOULD</td>
518 </tr>
519 <tr>
520 <td>Output</td>
521 <td>Speaker and/or Audio output ports</td>
522 <td><a href="#7_8_2_audio_output">7.8.2. Audio Output</a></td>
523 <td>MUST</td>
524 <td>MUST</td>
525 <td></td>
526 <td>MUST</td>
527 <td>MUST</td>
528 </tr>
529</table>
530
531
532<h1 id="3_software">3. Software</h1>
533
534
535<h2 id="3_1_managed_api_compatibility">3.1. Managed API Compatibility</h2>
536
537
538<p>The managed Dalvik bytecode execution environment is the primary vehicle for
539Android applications. The Android application programming interface (API) is
540the set of Android platform interfaces exposed to applications running in the
541managed runtime environment. Device implementations MUST provide complete
542implementations, including all documented behaviors, of any documented API
543exposed by the Android SDK [<a href="http://developer.android.com/reference/packages.html">Resources, 5</a>] or any API decorated with the &ldquo;@SystemApi&rdquo; marker in the upstream Android
544source code. </p>
545
546<p>Device implementations MUST NOT omit any managed APIs, alter API interfaces or
547signatures, deviate from the documented behavior, or include no-ops, except
548where specifically allowed by this Compatibility Definition.</p>
549
550<p>This Compatibility Definition permits some types of hardware for which Android
551includes APIs to be omitted by device implementations. In such cases, the APIs
552MUST still be present and behave in a reasonable way. See <a href="#7_hardware_compatibility">section 7</a> for specific requirements for this scenario.</p>
553
554<h2 id="3_2_soft_api_compatibility">3.2. Soft API Compatibility</h2>
555
556
557<p>In addition to the managed APIs from <a href="#3_1_managed_api_compatibility">section 3.1</a>, Android also includes a significant runtime-only &ldquo;soft&rdquo; API, in the form of
558such things as intents, permissions, and similar aspects of Android
559applications that cannot be enforced at application compile time.</p>
560
561<h3 id="3_2_1_permissions">3.2.1. Permissions</h3>
562
563
564<p>Device implementers MUST support and enforce all permission constants as
565documented by the Permission reference page [<a href="http://developer.android.com/reference/android/Manifest.permission.html">Resources, 6]</a>. Note that <a href="#9_security_model_compatibility">section 9</a> lists additional requirements related to the Android security model.</p>
566
567<h3 id="3_2_2_build_parameters">3.2.2. Build Parameters</h3>
568
569
570<p>The Android APIs include a number of constants on the android.os.Build class [<a href="http://developer.android.com/reference/android/os/Build.html">Resources, 7</a>] that are intended to describe the current device. To provide consistent,
571meaningful values across device implementations, the table below includes
572additional restrictions on the formats of these values to which device
573implementations MUST conform.</p>
574<table>
575 <tr>
576 <th>Parameter</th>
577 <th>Details</th>
578 </tr>
579 <tr>
580 <td>VERSION.RELEASE</td>
581 <td>The version of the currently-executing Android system, in human-readable
582format. This field MUST have one of the string values defined in [<a href="http://source.android.com/compatibility/ANDROID_VERSION/versions.html">Resources, 8]</a>.</td>
583 </tr>
584 <tr>
585 <td>VERSION.SDK</td>
586 <td>The version of the currently-executing Android system, in a format accessible
587to third-party application code. For Android ANDROID_VERSION, this field MUST have the
588integer value 22.</td>
589 </tr>
590 <tr>
591 <td>VERSION.SDK_INT</td>
592 <td>The version of the currently-executing Android system, in a format accessible
593to third-party application code. For Android ANDROID_VERSION, this field MUST have the
594integer value 22.</td>
595 </tr>
596 <tr>
597 <td>VERSION.INCREMENTAL</td>
598 <td>A value chosen by the device implementer designating the specific build of the
599currently-executing Android system, in human-readable format. This value MUST
600NOT be reused for different builds made available to end users. A typical use
601of this field is to indicate which build number or source-control change
602identifier was used to generate the build. There are no requirements on the
603specific format of this field, except that it MUST NOT be null or the empty
604string ("").</td>
605 </tr>
606 <tr>
607 <td>BOARD</td>
608 <td>A value chosen by the device implementer identifying the specific internal
609hardware used by the device, in human-readable format. A possible use of this
610field is to indicate the specific revision of the board powering the device.
611The value of this field MUST be encodable as 7-bit ASCII and match the regular
612expression &ldquo;^[a-zA-Z0-9_-]+$&rdquo;.</td>
613 </tr>
614 <tr>
615 <td>BRAND</td>
616 <td>A value reflecting the brand name associated with the device as known to the
617end users. MUST be in human-readable format and SHOULD represent the
618manufacturer of the device or the company brand under which the device is
619marketed. The value of this field MUST be encodable as 7-bit ASCII and match
620the regular expression &ldquo;^[a-zA-Z0-9_-]+$&rdquo;.</td>
621 </tr>
622 <tr>
623 <td>SUPPORTED_ABIS</td>
624 <td>The name of the instruction set (CPU type + ABI convention) of native code. See <a href="#3_3_native_api_compatibility">section 3.3. Native API Compatibility</a>.</td>
625 </tr>
626 <tr>
627 <td>SUPPORTED_32_BIT_ABIS</td>
628 <td>The name of the instruction set (CPU type + ABI convention) of native code. See <a href="#3_3_native_api_compatibility">section 3.3. Native API Compatibility</a>.</td>
629 </tr>
630 <tr>
631 <td>SUPPORTED_64_BIT_ABIS</td>
632 <td>The name of the second instruction set (CPU type + ABI convention) of native
633code. See <a href="#3_3_native_api_compatibility">section 3.3. Native API Compatibility</a>.</td>
634 </tr>
635 <tr>
636 <td>CPU_ABI</td>
637 <td>The name of the instruction set (CPU type + ABI convention) of native code. See <a href="#3_3_native_api_compatibility">section 3.3. Native API Compatibility</a>.</td>
638 </tr>
639 <tr>
640 <td>CPU_ABI2</td>
641 <td>The name of the second instruction set (CPU type + ABI convention) of native
642code. See <a href="#3_3_native_api_compatibility">section 3.3. Native API Compatibility</a>.</td>
643 </tr>
644 <tr>
645 <td>DEVICE</td>
646 <td>A value chosen by the device implementer containing the development name or
647code name identifying the configuration of the hardware features and industrial
648design of the device. The value of this field MUST be encodable as 7-bit ASCII
649and match the regular expression &ldquo;^[a-zA-Z0-9_-]+$&rdquo;.</td>
650 </tr>
651 <tr>
652 <td>FINGERPRINT</td>
653 <td>A string that uniquely identifies this build. It SHOULD be reasonably
654human-readable. It MUST follow this template:</p>
655
656<p class="small">$(BRAND)/$(PRODUCT)/$(DEVICE):$(VERSION.RELEASE)/$(ID)/$(VERSION.INCREMENTAL):$(TYPE)/$(TAGS)</p>
657
658<p>For example: acme/myproduct/mydevice:ANDROID_VERSION/LMYXX/3359:userdebug/test-keys</p>
659
660<p>The fingerprint MUST NOT include whitespace characters. If other fields
661included in the template above have whitespace characters, they MUST be
662replaced in the build fingerprint with another character, such as the
663underscore ("_") character. The value of this field MUST be encodable as 7-bit
664ASCII.</td>
665 </tr>
666 <tr>
667 <td>HARDWARE</td>
668 <td>The name of the hardware (from the kernel command line or /proc). It SHOULD be
669reasonably human-readable. The value of this field MUST be encodable as 7-bit
670ASCII and match the regular expression &ldquo;^[a-zA-Z0-9_-]+$&rdquo;. </td>
671 </tr>
672 <tr>
673 <td>HOST</td>
674 <td>A string that uniquely identifies the host the build was built on, in
675human-readable format. There are no requirements on the specific format of this
676field, except that it MUST NOT be null or the empty string ("").</td>
677 </tr>
678 <tr>
679 <td>ID</td>
680 <td>An identifier chosen by the device implementer to refer to a specific release,
681in human-readable format. This field can be the same as
682android.os.Build.VERSION.INCREMENTAL, but SHOULD be a value sufficiently
683meaningful for end users to distinguish between software builds. The value of
684this field MUST be encodable as 7-bit ASCII and match the regular expression &ldquo;^[a-zA-Z0-9._-]+$&rdquo;.</td>
685 </tr>
686 <tr>
687 <td>MANUFACTURER</td>
688 <td>The trade name of the Original Equipment Manufacturer (OEM) of the product.
689There are no requirements on the specific format of this field, except that it
690MUST NOT be null or the empty string ("").</td>
691 </tr>
692 <tr>
693 <td>MODEL</td>
694 <td>A value chosen by the device implementer containing the name of the device as
695known to the end user. This SHOULD be the same name under which the device is
696marketed and sold to end users. There are no requirements on the specific
697format of this field, except that it MUST NOT be null or the empty string ("").</td>
698 </tr>
699 <tr>
700 <td>PRODUCT</td>
701 <td>A value chosen by the device implementer containing the development name or
702code name of the specific product (SKU) that MUST be unique within the same
703brand. MUST be human-readable, but is not necessarily intended for view by end
704users. The value of this field MUST be encodable as 7-bit ASCII and match the
705regular expression &ldquo;^[a-zA-Z0-9_-]+$&rdquo;.</td>
706 </tr>
707 <tr>
708 <td>SERIAL</td>
709 <td>A hardware serial number, which MUST be available. The value of this field MUST
710be encodable as 7-bit ASCII and match the regular expression &ldquo;^([a-zA-Z0-9]{6,20})$&rdquo;.</td>
711 </tr>
712 <tr>
713 <td>TAGS</td>
714 <td>A comma-separated list of tags chosen by the device implementer that further
715distinguishes the build. This field MUST have one of the values corresponding
716to the three typical Android platform signing configurations: release-keys,
717dev-keys, test-keys. </td>
718 </tr>
719 <tr>
720 <td>TIME</td>
721 <td>A value representing the timestamp of when the build occurred.</td>
722 </tr>
723 <tr>
724 <td>TYPE</td>
725 <td>A value chosen by the device implementer specifying the runtime configuration
726of the build. This field MUST have one of the values corresponding to the three
727typical Android runtime configurations: user, userdebug, or eng.</td>
728 </tr>
729 <tr>
730 <td>USER</td>
731 <td>A name or user ID of the user (or automated user) that generated the build.
732There are no requirements on the specific format of this field, except that it
733MUST NOT be null or the empty string ("").</td>
734 </tr>
735</table>
736
737
738<h3 id="3_2_3_intent_compatibility">3.2.3. Intent Compatibility</h3>
739
740
741<p>Device implementations MUST honor Android&rsquo;s loose-coupling intent system, as
742described in the sections below. By&ldquo;honored &rdquo; it is meant that the device
743implementer MUST provide an Android Activity or Service that specifies a
744matching intent filter that binds to and implements correct behavior for each
745specified intent pattern.</p>
746
747<h4 id="3_2_3_1_core_application_intents">3.2.3.1. Core Application Intents</h4>
748
749
750<p>Android intents allow application components to request functionality from
751other Android components. The Android upstream project includes a list of
752applications considered core Android applications, which implements several
753intent patterns to perform common actions. The core Android applications are:</p>
754
755<ul>
756 <li>Desk Clock</li>
757 <li>Browser</li>
758 <li>Calendar</li>
759 <li>Contacts</li>
760 <li>Gallery</li>
761 <li>GlobalSearch</li>
762 <li>Launcher</li>
763 <li>Music</li>
764 <li>Settings</li>
765</ul>
766
767<p>Device implementations SHOULD include the core Android applications as
768appropriate but MUST include a component implementing the same intent patterns
769defined by all the &ldquo;public&rdquo; Activity or Service components of these core
770Android applications. Note that Activity or Service components are considered
771&ldquo;public&rdquo; when the attribute android:exported is absent or has the value true.</p>
772
773<h4 id="3_2_3_2_intent_overrides">3.2.3.2. Intent Overrides</h4>
774
775
776<p>As Android is an extensible platform, device implementations MUST allow each
777intent pattern referenced in <a href="#3_2_3_1_core_application_intents">section 3.2.3.1</a> to be overridden by third-party applications. The upstream Android open source
778implementation allows this by default; device implementers MUST NOT attach
779special privileges to system applications' use of these intent patterns, or
780prevent third-party applications from binding to and assuming control of these
781patterns. This prohibition specifically includes but is not limited to
782disabling the&ldquo;Chooser&rdquo; user interface that allows the user to select between
783multiple applications that all handle the same intent pattern.</p>
784
785<p>However, device implementations MAY provide default activities for specific URI
786patterns (eg. http://play.google.com) if the default activity provides a more
787specific filter for the data URI. For example, an intent filter specifying the
788data URI &ldquo;http://www.android.com&rdquo; is more specific than the browser filter for&ldquo;http://&rdquo;. Device implementations MUST provide a user interface for users to
789modify the default activity for intents.</p>
790
791<h4 id="3_2_3_3_intent_namespaces">3.2.3.3. Intent Namespaces</h4>
792
793
794<p>Device implementations MUST NOT include any Android component that honors any
795new intent or broadcast intent patterns using an ACTION, CATEGORY, or other key
796string in the android.* or com.android.* namespace. Device implementers MUST
797NOT include any Android components that honor any new intent or broadcast
798intent patterns using an ACTION, CATEGORY, or other key string in a package
799space belonging to another organization. Device implementers MUST NOT alter or
800extend any of the intent patterns used by the core apps listed in <a href="#3_2_3_1_core_application_intents">section 3.2.3.1</a>. Device implementations MAY include intent patterns using namespaces clearly
801and obviously associated with their own organization. This prohibition is
802analogous to that specified for Java language classes in <a href="#3_6_api_namespaces">section 3.6</a>.</p>
803
804<h4 id="3_2_3_4_broadcast_intents">3.2.3.4. Broadcast Intents</h4>
805
806
807<p>Third-party applications rely on the platform to broadcast certain intents to
808notify them of changes in the hardware or software environment.
809Android-compatible devices MUST broadcast the public broadcast intents in
810response to appropriate system events. Broadcast intents are described in the
811SDK documentation.</p>
812
813<h4 id="3_2_3_5_default_app_settings">3.2.3.5. Default App Settings</h4>
814
815
816<p>Android includes settings that provide users an easy way to select their
817default applications, for example for Home screen or SMS. Where it makes sense,
818device implementations MUST provide a similar settings menu and be compatible
819with the intent filter pattern and API methods described in the SDK
820documentation as below.</p>
821
822<p>Device implementations:</p>
823
824<ul>
825 <li>MUST honor the android.settings.HOME_SETTINGS intent to show a default app
826settings menu for Home Screen, if the device implementation reports
827android.software.home_screen [<a href="http://developer.android.com/reference/android/provider/Settings.html">Resources, 10]</a></li>
828 <li>MUST provide a settings menu that will call the
829android.provider.Telephony.ACTION_CHANGE_DEFAULT intent to show a dialog to
830change the default SMS application, if the device implementation reports
831android.hardware.telephony [<a href="http://developer.android.com/reference/android/provider/Telephony.Sms.Intents.html">Resources, 9</a>]</li>
832 <li>MUST honor the android.settings.NFC_PAYMENT_SETTINGS intent to show a default
833app settings menu for Tap and Pay, if the device implementation reports
834android.hardware.nfc.hce [<a href="http://developer.android.com/reference/android/provider/Settings.html">Resources, 10]</a></li>
835</ul>
836
837<h2 id="3_3_native_api_compatibility">3.3. Native API Compatibility</h2>
838
839
840<h3 id="3_3_1_application_binary_interfaces">3.3.1. Application Binary Interfaces</h3>
841
842
843<p>Managed Dalvik bytecode can call into native code provided in the application
844.apk file as an ELF .so file compiled for the appropriate device hardware
845architecture. As native code is highly dependent on the underlying processor
846technology, Android defines a number of Application Binary Interfaces (ABIs) in
847the Android NDK. Device implementations MUST be compatible with one or more
848defined ABIs, and MUST implement compatibility with the Android NDK, as below.</p>
849
850<p>If a device implementation includes support for an Android ABI, it:</p>
851
852<ul>
853 <li>MUST include support for code running in the managed environment to call into
854native code, using the standard Java Native Interface (JNI) semantics</li>
855 <li>MUST be source-compatible (i.e. header compatible) and binary-compatible (for
856the ABI) with each required library in the list below</li>
857 <li>MUST support the equivalent 32-bit ABI if any 64-bit ABI is supported</li>
858 <li>MUST accurately report the native Application Binary Interface (ABI) supported
859by the device, via the android.os.Build.SUPPORTED_ABIS,
860android.os.Build.SUPPORTED_32_BIT_ABIS, and
861android.os.Build.SUPPORTED_64_BIT_ABIS parameters, each a comma separated list
862of ABIs ordered from the most to the least preferred one</li>
863 <li>MUST report, via the above parameters, only those ABIs documented in the latest
864version of the Android NDK, &ldquo;NDK Programmer&rsquo;s Guide | ABI Management&rdquo; in docs/
865directory</li>
866 <li>SHOULD be built using the source code and header files available in the
867upstream Android Open Source Project</li>
868</ul>
869
870<p>The following native code APIs MUST be available to apps that include native
871code:</p>
872
873<ul>
874 <li>libc (C library)</li>
875 <li>libm (math library)</li>
876 <li>Minimal support for C++</li>
877 <li>JNI interface</li>
878 <li>liblog (Android logging)</li>
879 <li>libz (Zlib compression)</li>
880 <li>libdl (dynamic linker)</li>
881 <li>libGLESv1_CM.so (OpenGL ES 1.x)</li>
882 <li>libGLESv2.so (OpenGL ES 2.0)</li>
883 <li>libGLESv3.so (OpenGL ES 3.x)</li>
884 <li>libEGL.so (native OpenGL surface management)</li>
885 <li>libjnigraphics.so</li>
886 <li>libOpenSLES.so (OpenSL ES 1.0.1 audio support)</li>
887 <li>libOpenMAXAL.so (OpenMAX AL 1.0.1 support)</li>
888 <li>libandroid.so (native Android activity support)</li>
889 <li>libmediandk.so (native media APIs support)</li>
890 <li>Support for OpenGL, as described below</li>
891</ul>
892
893<p>Note that future releases of the Android NDK may introduce support for
894additional ABIs. If a device implementation is not compatible with an existing
895predefined ABI, it MUST NOT report support for any ABIs at all.</p>
896
897<p>Note that device implementations MUST include libGLESv3.so and it MUST symlink
898(symbolic link) to libGLESv2.so. in turn, MUST export all the OpenGL ES 3.1 and
899Android Extension Pack [<a href="http://developer.android.com/guide/topics/graphics/opengl.html#aep">Resources, 11</a>] function symbols as defined in the NDK release android-21. Although all the
900symbols must be present, only the corresponding functions for OpenGL ES
901versions and extensions actually supported by the device must be fully
902implemented.</p>
903
904<p>Native code compatibility is challenging. For this reason, device implementers
905are <strong>very strongly encouraged</strong> to use the implementations of the libraries listed above from the upstream
906Android Open Source Project. </p>
907
908<h3 id="3_3_2_32-bit_arm_native_code_compatibility">
9093.3.2. 32-bit ARM Native Code Compatibility
910</h3>
911
912<p>The ARMv8 architecture deprecates several CPU operations, including some
913operations used in existing native code. On 64-bit ARM devices, the following
914deprecated operations MUST remain available to 32-bit native ARM code, either
915through native CPU support or through software emulation:</p>
916
917<ul>
918<li>SWP and SWPB instructions</li>
919<li>SETEND instruction</li>
920<li>CP15ISB, CP15DSB, and CP15DMB barrier operations</li>
921</ul>
922
923<p>Legacy versions of the Android NDK used /proc/cpuinfo to discover CPU features
924from 32-bit ARM native code. For compatibility with applications built using this
925NDK, devices MUST include the following lines in /proc/cpuinfo when it is read
926by 32-bit ARM applications:</p>
927
928<ul>
929<li>&quot;Features: &quot;, followed by a list of any optional ARMv7 CPU features
930supported by the device</li>
931<li>&quot;CPU architecture: &quot;, followed by an integer describing the device's
932highest supported ARM architecture (e.g., &quot;8&quot; for ARMv8 devices)</li>
933</ul>
934
935<p>These requirements only apply when /proc/cpuinfo is read by 32-bit ARM
936applications. Devices SHOULD not alter /proc/cpuinfo when read by 64-bit ARM or
937non-ARM applications.</p>
938
939<h2 id="3_4_web_compatibility">3.4. Web Compatibility</h2>
940
941
942<h3 id="3_4_1_webview_compatibility">3.4.1. WebView Compatibility</h3>
943
944<div class="note">
945<p>Android Watch devices MAY, but all other device implementations MUST provide
946a complete implementation of the android.webkit.Webview API.</p>
947</div>
948
949
950<p>The platform feature android.software.webview MUST be reported on any device
951that provides a complete implementation of the android.webkit.WebView API, and
952MUST NOT be reported on devices without a complete implementation of the API.
953The Android Open Source implementation uses code from the Chromium Project to
954implement the android.webkit.WebView [<a href="http://developer.android.com/reference/android/webkit/WebView.html">Resources, 12</a>]. Because it is not feasible to develop a comprehensive test suite for a web
955rendering system, device implementers MUST use the specific upstream build of
956Chromium in the WebView implementation. Specifically:</p>
957
958<ul>
959 <li>Device android.webkit.WebView implementations MUST be based on the Chromium
960build from the upstream Android Open Source Project for Android ANDROID_VERSION. This build
961includes a specific set of functionality and security fixes for the WebView [<a href="http://www.chromium.org/">Resources, 13</a>].</li>
962 <li>The user agent string reported by the WebView MUST be in this format:
963<p>Mozilla/5.1 (Linux; Android $(VERSION); $(MODEL) Build/$(BUILD)$(WEBVIEW))
964AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 $(CHROMIUM_VER) Mobile
965Safari/537.36</p>
966 <ul>
967 <li>The value of the $(VERSION) string MUST be the same as the value for
968android.os.Build.VERSION.RELEASE.</li>
969 <li>The $(WEBVIEW) string MAY be omitted, but if included MUST be "; wv" to
970 note that this is a webview</li>
971 <li>The value of the $(MODEL) string MUST be the same as the value for
972android.os.Build.MODEL.</li>
973 <li>The value of the $(BUILD) string MUST be the same as the value for
974android.os.Build.ID.</li>
975 <li>The value of the $(CHROMIUM_VER) string MUST be the version of Chromium in the
976upstream Android Open Source Project.</li>
977 <li>Device implementations MAY omit Mobile in the user agent string.</li>
978 </ul></li></ul>
979
980<p>The WebView component SHOULD include support for as many HTML5 features as
981possible and if it supports the feature SHOULD conform to the HTML5
982specification [<a href="http://html.spec.whatwg.org/multipage/">Resources, 14</a>].</p>
983
984<h3 id="3_4_2_browser_compatibility">3.4.2. Browser Compatibility</h3>
985
986<div class="note">
987<p>Android Television, Watch, and Android Automotive implementations MAY omit a
988browser application, but MUST support the public intent patterns as described in
989<a href="#3_2_3_1_core_application_intents">section 3.2.3.1</a>. All other types
990of device implementations MUST include a standalone Browser application for
991general user web browsing.</p>
992</div>
993
994<p>The standalone Browser MAY be based on a browser technology other than WebKit.
995However, even if an alternate Browser application is used, the
996android.webkit.WebView component provided to third-party applications MUST be
997based on WebKit, as described in <a href="#3_4_1_webview_compatibility">section 3.4.1</a>.</p>
998
999<p>Implementations MAY ship a custom user agent string in the standalone Browser
1000application.</p>
1001
1002<p>The standalone Browser application (whether based on the upstream WebKit
1003Browser application or a third-party replacement) SHOULD include support for as
1004much of HTML5 [<a href="http://html.spec.whatwg.org/multipage/">Resources, 14</a>] as possible. Minimally, device implementations MUST support each of these
1005APIs associated with HTML5:</p>
1006
1007<ul>
1008 <li>application cache/offline operation [<a href="http://www.w3.org/html/wg/drafts/html/master/browsers.html#offline">Resources, 15</a>]</li>
1009 <li>the &#60;video&#62; tag [<a href="http://www.w3.org/html/wg/drafts/html/master/semantics.html#video">Resources, 16</a>]</li>
1010 <li>geolocation [<a href="http://www.w3.org/TR/geolocation-API/">Resources, 17</a>]</li>
1011</ul>
1012
1013<p>Additionally, device implementations MUST support the HTML5/W3C webstorage API
1014[<a href="http://www.w3.org/TR/webstorage/">Resources, 18</a>], and SHOULD support the HTML5/W3C IndexedDB API [<a href="http://www.w3.org/TR/IndexedDB/">Resources, 19</a>]. Note that as the web development standards bodies are transitioning to favor
1015IndexedDB over webstorage, IndexedDB is expected to become a required component
1016in a future version of Android.</p>
1017
1018<h2 id="3_5_api_behavioral_compatibility">3.5. API Behavioral Compatibility</h2>
1019
1020
1021<p>The behaviors of each of the API types (managed, soft, native, and web) must be
1022consistent with the preferred implementation of the upstream Android Open
1023Source Project [<a href="http://source.android.com/">Resources, 2</a>]. Some specific areas of compatibility are:</p>
1024
1025<ul>
1026 <li>Devices MUST NOT change the behavior or semantics of a standard intent.</li>
1027 <li>Devices MUST NOT alter the lifecycle or lifecycle semantics of a particular
1028type of system component (such as Service, Activity, ContentProvider, etc.).</li>
1029 <li>Devices MUST NOT change the semantics of a standard permission.</li>
1030</ul>
1031
1032<p>The above list is not comprehensive. The Compatibility Test Suite (CTS) tests
1033significant portions of the platform for behavioral compatibility, but not all.
1034It is the responsibility of the implementer to ensure behavioral compatibility
1035with the Android Open Source Project. For this reason, device implementers
1036SHOULD use the source code available via the Android Open Source Project where
1037possible, rather than re-implement significant parts of the system.</p>
1038
1039<h2 id="3_6_api_namespaces">3.6. API Namespaces</h2>
1040
1041
1042<p>Android follows the package and class namespace conventions defined by the Java
1043programming language. To ensure compatibility with third-party applications,
1044device implementers MUST NOT make any prohibited modifications (see below) to
1045these package namespaces:</p>
1046
1047<ul>
1048 <li>java.*</li>
1049 <li>javax.*</li>
1050 <li>sun.*</li>
1051 <li>android.*</li>
1052 <li>com.android.*</li>
1053</ul>
1054
1055<p><strong>Prohibited modifications include</strong>:</p>
1056
1057<ul>
1058 <li>Device implementations MUST NOT modify the publicly exposed APIs on the Android
1059platform by changing any method or class signatures, or by removing classes or
1060class fields.</li>
1061 <li>Device implementers MAY modify the underlying implementation of the APIs, but
1062such modifications MUST NOT impact the stated behavior and Java-language
1063signature of any publicly exposed APIs.</li>
1064 <li>Device implementers MUST NOT add any publicly exposed elements (such as classes
1065or interfaces, or fields or methods to existing classes or interfaces) to the
1066APIs above.</li>
1067</ul>
1068
1069<p>A &ldquo;publicly exposed element&rdquo; is any construct which is not decorated with the&ldquo;@hide&rdquo; marker as used in the upstream Android source code. In other words,
1070device implementers MUST NOT expose new APIs or alter existing APIs in the
1071namespaces noted above. Device implementers MAY make internal-only
1072modifications, but those modifications MUST NOT be advertised or otherwise
1073exposed to developers.</p>
1074
1075<p>Device implementers MAY add custom APIs, but any such APIs MUST NOT be in a
1076namespace owned by or referring to another organization. For instance, device
1077implementers MUST NOT add APIs to the com.google.* or similar namespace: only
1078Google may do so. Similarly, Google MUST NOT add APIs to other companies'
1079namespaces. Additionally, if a device implementation includes custom APIs
1080outside the standard Android namespace, those APIs MUST be packaged in an
1081Android shared library so that only apps that explicitly use them (via the
1082<uses-library> mechanism) are affected by the increased memory usage of such
1083APIs.</p>
1084
1085<p>If a device implementer proposes to improve one of the package namespaces above
1086(such as by adding useful new functionality to an existing API, or adding a new
1087API), the implementer SHOULD visit <a href="http://source.android.com/">source.android.com</a> and begin the process for contributing changes and code, according to the
1088information on that site.</p>
1089
1090<p>Note that the restrictions above correspond to standard conventions for naming
1091APIs in the Java programming language; this section simply aims to reinforce
1092those conventions and make them binding through inclusion in this Compatibility
1093Definition.</p>
1094
1095<h2 id="3_7_runtime_compatibility">3.7. Runtime Compatibility</h2>
1096
1097
1098<p>Device implementations MUST support the full Dalvik Executable (DEX) format and
1099Dalvik bytecode specification and semantics [<a href="https://android.googlesource.com/platform/dalvik/+/lollipop-release/docs/">Resources, 20</a>]. Device implementers SHOULD use ART, the reference upstream implementation of
1100the Dalvik Executable Format, and the reference implementation&rsquo;s package
1101management system.</p>
1102
1103<p>Device implementations MUST configure Dalvik runtimes to allocate memory in
1104accordance with the upstream Android platform, and as specified by the
1105following table. (See <a href="#7_1_1_screen_configuration">section 7.1.1</a> for screen size and screen density definitions.)</p>
1106
1107<p>Note that memory values specified below are considered minimum values and
1108device implementations MAY allocate more memory per application.</p>
1109
1110<table>
1111 <tr>
1112 <th>Screen Layout</th>
1113 <th>Screen Density</th>
1114 <th>Minimum Application Memory</th>
1115 </tr>
1116 <tr>
1117 <td rowspan="10">small/normal</td>
1118 <td>120 dpi (ldpi)</td>
1119 <td rowspan="2">32MB</td>
1120 </tr>
1121 <tr>
1122 <td>160 dpi (mdpi)</td>
1123 </tr>
1124 <tr>
1125 <td>213 dpi (tvdpi)</td>
1126 <td rowspan="3">48MB</td>
1127 </tr>
1128 <tr>
1129 <td>240 dpi (hdpi)</td>
1130 </tr>
1131 <tr>
1132 <td>280 dpi (280dpi)</td>
1133 </tr>
1134 <tr>
1135 <td>320 dpi (xhdpi)</td>
1136 <td>80MB</td>
1137 </tr>
1138 <tr>
1139 <td>400 dpi (400dpi)</td>
1140 <td>96MB</td>
1141 </tr>
1142 <tr>
1143 <td>480 dpi (xxhdpi)</td>
1144 <td>128MB</td>
1145 </tr>
1146 <tr>
1147 <td>560 dpi (560dpi)</td>
1148 <td>192MB</td>
1149 </tr>
1150 <tr>
1151 <td>640 dpi (xxxhdpi)</td>
1152 <td>256MB</td>
1153 </tr>
1154 <tr>
1155 <td rowspan="10">large</td>
1156 <td>120 dpi (ldpi)</td>
1157 <td>32MB</td>
1158 </tr>
1159 <tr>
1160 <td>160 dpi (mdpi)</td>
1161 <td>48MB</td>
1162 </tr>
1163 <tr>
1164 <td>213 dpi (tvdpi)</td>
1165 <td rowspan="2">80MB</td>
1166 </tr>
1167 <tr>
1168 <td>240 dpi (hdpi)</td>
1169 </tr>
1170 <tr>
1171 <td>280 dpi (280dpi)</td>
1172 <td>96MB</td>
1173 </tr>
1174 <tr>
1175 <td>320 dpi (xhdpi)</td>
1176 <td>128MB</td>
1177 </tr>
1178 <tr>
1179 <td>400 dpi (400dpi)</td>
1180 <td>192MB</td>
1181 </tr>
1182 <tr>
1183 <td>480 dpi (xxhdpi)</td>
1184 <td>256MB</td>
1185 </tr>
1186 <tr>
1187 <td>560 dpi (560dpi)</td>
1188 <td>384MB</td>
1189 </tr>
1190 <tr>
1191 <td>640 dpi (xxxhdpi)</td>
1192 <td>512MB</td>
1193 </tr>
1194 <tr>
1195 <td rowspan="10">xlarge</td>
1196 <td>120 dpi (ldpi)</td>
1197 <td>48MB</td>
1198 </tr>
1199 <tr>
1200 <td>160 dpi (mdpi)</td>
1201 <td>80MB</td>
1202 </tr>
1203 <tr>
1204 <td>213 dpi (tvdpi)</td>
1205 <td rowspan="2">96MB</td>
1206 </tr>
1207 <tr>
1208 <td>240 dpi (hdpi)</td>
1209 </tr>
1210 <tr>
1211 <td>280 dpi (280dpi)</td>
1212 <td>144MB</td>
1213 </tr>
1214 <tr>
1215 <td>320 dpi (xhdpi)</td>
1216 <td>192MB</td>
1217 </tr>
1218 <tr>
1219 <td>400 dpi (400dpi)</td>
1220 <td>288MB</td>
1221 </tr>
1222 <tr>
1223 <td>480 dpi (xxhdpi)</td>
1224 <td>384MB</td>
1225 </tr>
1226 <tr>
1227 <td>560 dpi (560dpi)</td>
1228 <td>576MB</td>
1229 </tr>
1230 <tr>
1231 <td>640 dpi (xxxhdpi)</td>
1232 <td>768MB</td>
1233 </tr>
1234</table>
1235
1236
1237<h2 id="3_8_user_interface_compatibility">3.8. User Interface Compatibility</h2>
1238
1239
1240<h3 id="3_8_1_launcher_home_screen">3.8.1. Launcher (Home Screen)</h3>
1241
1242
1243<p>Android includes a launcher application (home screen) and support for
1244third-party applications to replace the device launcher (home screen). Device
1245implementations that allow third-party applications to replace the device home
1246screen MUST declare the platform feature android.software.home_screen.</p>
1247
1248<h3 id="3_8_2_widgets">3.8.2. Widgets</h3>
1249
1250<div class="note">
1251<p>Widgets are optional for all Android device implementations, but SHOULD be
1252supported on Android Handheld devices.</p>
1253</div>
1254
1255
1256<p>Android defines a component type and corresponding API and lifecycle that
1257allows applications to expose an &ldquo;AppWidget&rdquo; to the end user [<a href="http://developer.android.com/guide/practices/ui_guidelines/widget_design.html">Resources, 21</a>] a feature that is strongly RECOMMENDED to be supported on Handheld Device
1258implementations. Device implementations that support embedding widgets on the
1259home screen MUST meet the following requirements and declare support for
1260platform feature android.software.app_widgets.</p>
1261
1262<ul>
1263 <li>Device launchers MUST include built-in support for AppWidgets, and expose user
1264interface affordances to add, configure, view, and remove AppWidgets directly
1265within the Launcher.</li>
1266 <li>Device implementations MUST be capable of rendering widgets that are 4 x 4 in
1267the standard grid size. See the App Widget Design Guidelines in the Android SDK
1268documentation [<a href="http://developer.android.com/guide/practices/ui_guidelines/widget_design.html">Resources, 21</a>] for details.</li>
1269 <li>Device implementations that include support for lock screen MAY support
1270application widgets on the lock screen.</li>
1271</ul>
1272
1273<h3 id="3_8_3_notifications">3.8.3. Notifications</h3>
1274
1275
1276<p>Android includes APIs that allow developers to notify users of notable events [<a href="http://developer.android.com/guide/topics/ui/notifiers/notifications.html">Resources, 22</a>], using hardware and software features of the device.</p>
1277
1278<p>Some APIs allow applications to perform notifications or attract attention
1279using hardware&#8212;specifically sound, vibration, and light. Device implementations
1280MUST support notifications that use hardware features, as described in the SDK
1281documentation, and to the extent possible with the device implementation
1282hardware. For instance, if a device implementation includes a vibrator, it MUST
1283correctly implement the vibration APIs. If a device implementation lacks
1284hardware, the corresponding APIs MUST be implemented as no-ops. This behavior
1285is further detailed in <a href="#7_hardware_compatibility">section 7</a>.</p>
1286
1287<p>Additionally, the implementation MUST correctly render all resources (icons, animation files
1288etc.) provided for in the APIs
1289[<a href="https://developer.android.com/guide/topics/resources/available-resources.html">Resources, 23</a>],
1290or in the Status/System Bar icon style guide
1291[<a href="http://developer.android.com/design/style/iconography.html">Resources, 24</a>],
1292which in the case of an Android Television device includes the possibility to not display the
1293notifications. Device implementers MAY provide an alternative user experience for
1294notifications than that provided by the reference Android Open Source
1295implementation; however, such alternative notification systems MUST support
1296existing notification resources, as above. </p>
1297
1298<p>Android includes support for various notifications, such as:</p>
1299
1300<ul>
1301 <li><strong>Rich notifications</strong>. Interactive Views for ongoing notifications.</li>
1302 <li><strong>Heads-up notifications</strong>. Interactive Views users can act on or dismiss without leaving the current app.</li>
1303 <li><strong>Lockscreen notifications</strong>. Notifications shown over a lock screen with granular control on visibility.</li>
1304</ul>
1305
1306<p>Android device implementations, when such notifications are made visible, MUST properly execute
1307Rich and Heads-up notifications and include the title/name, icon, text as documented in the Android
1308APIs <a href="https://developer.android.com/design/patterns/notifications.html">[Resources, 25]</a>.
1309</p>
1310
1311<p>Android includes Notification Listener Service APIs that allow apps (once
1312explicitly enabled by the user) to receive a copy of all notifications as they
1313are posted or updated. Device implementations MUST correctly and promptly send
1314notifications in their entirety to all such installed and user-enabled listener
1315services, including any and all metadata attached to the Notification object.</p>
1316
1317<h3 id="3_8_4_search">3.8.4. Search</h3>
1318
1319
1320<p>Android includes APIs [<a href="http://developer.android.com/reference/android/app/SearchManager.html">Resources, 26</a>] that allow developers to incorporate search into their applications, and
1321expose their application&rsquo;s data into the global system search. Generally
1322speaking, this functionality consists of a single, system-wide user interface
1323that allows users to enter queries, displays suggestions as users type, and
1324displays results. The Android APIs allow developers to reuse this interface to
1325provide search within their own apps, and allow developers to supply results to
1326the common global search user interface.</p>
1327
1328<p>Android device implementations SHOULD include global search, a single, shared,
1329system-wide search user interface capable of real-time suggestions in response
1330to user input. Device implementations SHOULD implement the APIs that allow
1331developers to reuse this user interface to provide search within their own
1332applications. Device implementations that implement the global search interface
1333MUST implement the APIs that allow third-party applications to add suggestions
1334to the search box when it is run in global search mode. If no third-party
1335applications are installed that make use of this functionality, the default
1336behavior SHOULD be to display web search engine results and suggestions.</p>
1337
1338<h3 id="3_8_5_toasts">3.8.5. Toasts</h3>
1339
1340
1341<p>Applications can use the &ldquo;Toast&rdquo; API to display short non-modal strings to the
1342end user, that disappear after a brief period of time [<a href="http://developer.android.com/reference/android/widget/Toast.html">Resources, 27</a>]. Device implementations MUST display Toasts from applications to end users in
1343some high-visibility manner.</p>
1344
1345<h3 id="3_8_6_themes">3.8.6. Themes</h3>
1346
1347
1348<p>Android provides &ldquo;themes&rdquo; as a mechanism for applications to apply styles
1349across an entire Activity or application.</p>
1350
1351<p>Android includes a &ldquo;Holo&rdquo; theme family as a set of defined styles for
1352application developers to use if they want to match the Holo theme look and
1353feel as defined by the Android SDK [<a href="http://developer.android.com/guide/topics/ui/themes.html">Resources, 28</a>]. Device implementations MUST NOT alter any of the Holo theme attributes
1354exposed to applications [<a href="http://developer.android.com/reference/android/R.style.html">Resources, 29</a>].</p>
1355
1356<p>Android includes a &ldquo;Material&rdquo; theme family as a set of defined styles for
1357application developers to use if they want to match the design theme&rsquo;s look and
1358feel across the wide variety of different Android device types. Device
1359implementations MUST support the &ldquo;Material&rdquo; theme family and MUST NOT alter any
1360of the Material theme attributes or their assets exposed to applications [<a href="http://developer.android.com/reference/android/R.style.html#Theme_Material">Resources, 30</a>].</p>
1361
1362<p>Android also includes a &ldquo;Device Default&rdquo; theme family as a set of defined
1363styles for application developers to use if they want to match the look and
1364feel of the device theme as defined by the device implementer. Device
1365implementations MAY modify the Device Default theme attributes exposed to
1366applications [<a href="http://developer.android.com/reference/android/R.style.html">Resources, 29</a>].</p>
1367
1368<p>Android supports a new variant theme with translucent system bars, which allows
1369application developers to fill the area behind the status and navigation bar
1370with their app content. To enable a consistent developer experience in this
1371configuration, it is important the status bar icon style is maintained across
1372different device implementations. Therefore, Android device implementations
1373MUST use white for system status icons (such as signal strength and battery
1374level) and notifications issued by the system, unless the icon is indicating a
1375problematic status [<a href="http://developer.android.com/reference/android/R.style.html">Resources, 29</a>].</p>
1376
1377<h3 id="3_8_7_live_wallpapers">3.8.7. Live Wallpapers</h3>
1378
1379
1380<p>Android defines a component type and corresponding API and lifecycle that
1381allows applications to expose one or more &ldquo;Live Wallpapers&rdquo; to the end user [<a href="http://developer.android.com/reference/android/service/wallpaper/WallpaperService.html">Resources, 31</a>]. Live wallpapers are animations, patterns, or similar images with limited
1382input capabilities that display as a wallpaper, behind other applications.</p>
1383
1384<p>Hardware is considered capable of reliably running live wallpapers if it can
1385run all live wallpapers, with no limitations on functionality, at a reasonable
1386frame rate with no adverse effects on other applications. If limitations in the
1387hardware cause wallpapers and/or applications to crash, malfunction, consume
1388excessive CPU or battery power, or run at unacceptably low frame rates, the
1389hardware is considered incapable of running live wallpaper. As an example, some
1390live wallpapers may use an OpenGL 2.0 or 3.x context to render their content.
1391Live wallpaper will not run reliably on hardware that does not support multiple
1392OpenGL contexts because the live wallpaper use of an OpenGL context may
1393conflict with other applications that also use an OpenGL context.</p>
1394
1395<p>Device implementations capable of running live wallpapers reliably as described
1396above SHOULD implement live wallpapers, and when implemented MUST report the
1397platform feature flag android.software.live_wallpaper.</p>
1398
1399<h3 id="3_8_8_activity_switching">3.8.8. Activity Switching</h3>
1400
1401<div class="note">
1402<p>As the Recent function navigation key is OPTIONAL, the requirements to
1403implement the overview screen is OPTIONAL for Android Television devices and
1404Android Watch devices.</p>
1405</div>
1406
1407
1408<p>The upstream Android source code includes the overview screen [<a href="http://developer.android.com/guide/components/recents.html">Resources, 32</a>], a system-level user interface for task switching and displaying recently
1409accessed activities and tasks using a thumbnail image of the application&rsquo;s
1410graphical state at the moment the user last left the application. Device
1411implementations including the recents function navigation key as detailed in <a href="#7_2_3_navigation_keys">section 7.2.3</a>, MAY alter the interface but MUST meet the following requirements:</p>
1412
1413<ul>
1414 <li>MUST display affiliated recents as a group that moves together.</li>
1415 <li>MUST support at least up to 20 displayed activities.</li>
1416 <li>MUST at least display the title of 4 activities at a time.</li>
1417 <li>SHOULD display highlight color, icon, screen title in recents.</li>
1418 <li>MUST implement the screen pinning behavior [<a href="http://developer.android.com/about/versions/android-5.0.html#ScreenPinning">Resources, 33</a>] and provide the user with a settings menu to toggle the feature.</li>
1419 <li>SHOULD display a closing affordance ("x") but MAY delay this until user
1420interacts with screens.</li>
1421</ul>
1422
1423<p>Device implementations are STRONGLY ENCOURAGED to use the upstream Android user
1424interface (or a similar thumbnail-based interface) for the overview screen.</p>
1425
1426<h3 id="3_8_9_input_management">3.8.9. Input Management</h3>
1427
1428
1429<p>Android includes support for Input Management and support for third-party input
1430method editors [<a href="http://developer.android.com/guide/topics/text/creating-input-method.html">Resources, 34</a>]. Device implementations that allow users to use third-party input methods on
1431the device MUST declare the platform feature android.software.input_methods and
1432support IME APIs as defined in the Android SDK documentation.</p>
1433
1434<p>Device implementations that declare the android.software.input_methods feature
1435MUST provide a user-accessible mechanism to add and configure third-party input
1436methods. Device implementations MUST display the settings interface in response
1437to the android.settings.INPUT_METHOD_SETTINGS intent.</p>
1438
1439<h3 id="3_8_10_lock_screen_media_control">3.8.10. Lock Screen Media Control</h3>
1440
1441
1442<p>The Remote Control Client API is deprecated from Android 5.0 in favor of the
1443Media Notification Template that allows media applications to integrate with
1444playback controls that are displayed on the lock screen [<a href="http://developer.android.com/reference/android/app/Notification.MediaStyle.html">Resources, 35</a>].
1445Device implementations that support a lock screen, unless an Android Automotive or Watch
1446implementation, MUST display the Lockscreen Notifications including the Media Notification
1447Template.</p>
1448
1449<h3 id="3_8_11_dreams">3.8.11. Dreams</h3>
1450
1451
1452<p>Android includes support for interactive screensavers called Dreams [<a href="http://developer.android.com/reference/android/service/dreams/DreamService.html">Resources, 36</a>]. Dreams allows users to interact with applications when a device connected to
1453a power source is idle or docked in a desk dock. Android Watch devices MAY
1454implement Dreams, but other types of device implementations SHOULD include
1455support for Dreams and provide a settings option for users to configure Dreams
1456in response to the android.settings.DREAM_SETTINGS intent.</p>
1457
1458<h3 id="3_8_12_location">3.8.12. Location</h3>
1459
1460
1461<p>When a device has a hardware sensor (e.g. GPS) that is capable of providing the
1462location coordinates, location modes MUST be displayed in the Location menu
1463within Settings [<a href="http://developer.android.com/reference/android/provider/Settings.Secure.html#LOCATION_MODE">Resources, 37</a>].</p>
1464
1465<h3 id="3_8_13_unicode_and_font">3.8.13. Unicode and Font</h3>
1466
1467
1468<p>Android includes support for color emoji characters. When Android device
1469implementations include an IME, devices SHOULD provide an input method to the
1470user for the Emoji characters defined in Unicode 6.1 [<a href="http://www.unicode.org/versions/Unicode6.1.0/">Resources, 38</a>]. All devices MUST be capable of rendering these emoji characters in color glyph.</p>
1471
1472<p>Android includes support for Roboto 2 font with different
1473weights&mdash;sans-serif-thin, sans-serif-light, sans-serif-medium, sans-serif-black,
1474sans-serif-condensed, sans-serif-condensed-light&mdash;which MUST all be included for
1475the languages available on the device and full Unicode 7.0 coverage of Latin,
1476Greek, and Cyrillic, including the Latin Extended A, B, C, and D ranges, and
1477all glyphs in the currency symbols block of Unicode 7.0.</p>
1478
1479<h2 id="3_9_device_administration">3.9. Device Administration</h2>
1480
1481
1482<p>Android includes features that allow security-aware applications to perform
1483device administration functions at the system level, such as enforcing password
1484policies or performing remote wipe, through the Android Device Administration
1485API [<a href="http://developer.android.com/guide/topics/admin/device-admin.html">Resources, 39</a>].
1486Device implementations MUST provide an implementation of the DevicePolicyManager class
1487[<a href="http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html">Resources, 40</a>].
1488Device implementations that include support for PIN (numeric) or PASSWORD
1489(alphanumeric) based lock screens MUST support the full range of device
1490administration policies defined in the Android SDK documentation
1491[<a href="http://developer.android.com/guide/topics/admin/device-admin.html">Resources, 39</a>]
1492and report the platform feature android.software.device_admin.</p>
1493
1494<p>Device implementations MAY have a preinstalled application performing device
1495administration functions but this application MUST NOT be set out-of-the box as
1496the default Device Owner app [<a href="http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html#isDeviceOwnerApp(java.lang.String)">Resources, 41</a>].</p>
1497
1498<h2 id="3_10_accessibility">3.10. Accessibility</h2>
1499
1500
1501<p>Android provides an accessibility layer that helps users with disabilities to
1502navigate their devices more easily. In addition, Android provides platform APIs
1503that enable accessibility service implementations to receive callbacks for user
1504and system events and generate alternate feedback mechanisms, such as
1505text-to-speech, haptic feedback, and trackball/d-pad navigation [<a href="http://developer.android.com/reference/android/accessibilityservice/AccessibilityService.html">Resources, 42</a>].</p>
1506
1507<p>Device implementations include the following requirements:</p>
1508
1509<ul>
1510<li>Android Automotive implementations SHOULD provide an implementation of the
1511Android accessibility framework consistent with the default Android
1512implementation.</li>
1513<li>Device implementations (Android Automotive excluded) MUST provide an
1514implementation of the Android accessibility framework consistent with the
1515default Android implementation.</li>
1516<li>Device implementations (Android Automotive excluded) MUST support
1517third-party accessibility service implementations through the
1518android.accessibilityservice APIs
1519[<a href="http://developer.android.com/reference/android/view/accessibility/package-summary.html">Resources, 43</a>]</li>
1520<li>Device implementations (Android Automotive excluded) MUST generate
1521AccessibilityEvents and deliver these events to all registered
1522AccessibilityService implementations in a manner consistent with the default
1523Android implementation</li>
1524<li> Device implementations (Android Automotive and Android Watch devices with
1525no audio output excluded), MUST provide a user-accessible mechanism to enable
1526and disable accessibility services, and MUST display this interface in response
1527to the android.provider.Settings.ACTION_ACCESSIBILITY_SETTINGS intent.</li>
1528</ul>
1529
1530<p>Additionally, device implementations SHOULD provide an implementation of an
1531accessibility service on the device, and SHOULD provide a mechanism for users
1532to enable the accessibility service during device setup. An open source
1533implementation of an accessibility service is available from the Eyes Free
1534project [<a href="http://code.google.com/p/eyes-free/">Resources, 44</a>].</p>
1535
1536<h2 id="3_11_text-to-speech">3.11. Text-to-Speech</h2>
1537
1538
1539<p>Android includes APIs that allow applications to make use of text-to-speech
1540(TTS) services and allows service providers to provide implementations of TTS
1541services [<a href="http://developer.android.com/reference/android/speech/tts/package-summary.html">Resources, 45</a>]. Device implementations reporting the feature android.hardware.audio.output
1542MUST meet these requirements related to the Android TTS framework. </p>
1543
1544<p>Android Automotive implementations:</p>
1545<ul>
1546<li>MUST support the Android TTS framework APIs.</li>
1547<li>MAY support installation of third-party TTS engines. If supported, partners
1548MUST provide a user-accessible interface that allows the user to select a TTS
1549engine for use at system level.</li>
1550</ul>
1551
1552<p>All other device implementations:</p>
1553
1554<ul>
1555 <li> MUST support the Android TTS framework APIs and SHOULD include a TTS engine
1556supporting the languages available on the device. Note that the upstream
1557Android open source software includes a full-featured TTS engine
1558implementation.
1559 <li> MUST support installation of third-party TTS engines
1560 <li> MUST provide a user-accessible interface that allows users to select a TTS
1561engine for use at the system level
1562</ul>
1563
1564<h2 id="3_12_tv_input_framework">3.12. TV Input Framework</h2>
1565
1566
1567<p>The Android Television Input Framework (TIF) simplifies the delivery of live
1568content to Android Television devices. TIF provides a standard API to create
1569input modules that control Android Television devices. Android Television
1570device implementations MUST support Television Input Framework [<a href="http://source.android.com/devices/tv/index.html">Resources, 46</a>].</p>
1571
1572<p>Device implementations that support TIF MUST declare the platform feature
1573android.software.live_tv.</p>
1574
1575<h1 id="4_application_packaging_compatibility">4. Application Packaging Compatibility</h1>
1576
1577
1578<p>Device implementations MUST install and run Android &ldquo;.apk&rdquo; files as generated
1579by the &ldquo;aapt&rdquo; tool included in the official Android SDK [<a href="http://developer.android.com/tools/help/index.html">Resources, 47</a>].</p>
1580
1581<p>Devices implementations MUST NOT extend either the .apk [<a href="http://developer.android.com/guide/components/fundamentals.html">Resources, 48</a>], Android Manifest [<a href="http://developer.android.com/guide/topics/manifest/manifest-intro.html">Resources, 49</a>], Dalvik bytecode [<a href="https://android.googlesource.com/platform/dalvik/+/lollipop-release/docs/">Resources, 20</a>], or RenderScript bytecode formats in such a way that would prevent those
1582files from installing and running correctly on other compatible devices.</p>
1583
1584<h1 id="5_multimedia_compatibility">5. Multimedia Compatibility</h1>
1585
1586
1587<h2 id="5_1_media_codecs">5.1. Media Codecs</h2>
1588
1589
1590<p>Device implementations MUST support the core media formats specified in the
1591Android SDK documentation [<a href="http://developer.android.com/guide/appendix/media-formats.html">Resources, 50</a>] except where explicitly permitted in this document. Specifically, device
1592implementations MUST support the media formats, encoders, decoders, file types,
1593and container formats defined in the tables below and reported via MediaCodecList
1594[<a href="http://developer.android.com/reference/android/media/MediaCodecList.html">Resources,112</a>].
1595Device implementations MUST also be able to decode all profiles reported in its CamcorderProfile
1596[<a href="http://developer.android.com/reference/android/media/CamcorderProfile.html">Resources,
1597113</a>].
1598
1599All of these codecs are
1600provided as software implementations in the preferred Android implementation
1601from the Android Open Source Project.</p>
1602
1603<p>Please note that neither Google nor the Open Handset Alliance make any
1604representation that these codecs are free from third-party patents. Those
1605intending to use this source code in hardware or software products are advised
1606that implementations of this code, including in open source software or
1607shareware, may require patent licenses from the relevant patent holders.</p>
1608
1609<h3 id="5_1_1_audio_codecs">5.1.1. Audio Codecs</h3>
1610
1611<table>
1612 <tr>
1613 <th>Format/Codec</th>
1614 <th>Encoder</th>
1615 <th>Decoder</th>
1616 <th>Details</th>
1617 <th>Supported File Types/Container Formats</th>
1618 </tr>
1619 <tr>
1620 <td>MPEG-4 AAC Profile</p>
1621
1622<p>(AAC LC)</td>
1623 <td>REQUIRED<sup>1</sup></td>
1624 <td>REQUIRED</td>
1625 <td>Support for mono/stereo/5.0/5.12 content with standard sampling rates from 8 to
162648 kHz.</td>
1627 <td>
1628 <ul>
1629 <li class="table_list">3GPP (.3gp)</li>
1630 <li class="table_list">MPEG-4 (.mp4, .m4a)</li>
1631 <li class="table_list">ADTS raw AAC (.aac, decode in Android 3.1+, encode in Android 4.0+, ADIF not
1632supported)</li>
1633 <li class="table_list">MPEG-TS (.ts, not seekable, Android 3.0+)</li></ul></td>
1634 </tr>
1635 <tr>
1636 <td>MPEG-4 HE AAC Profile (AAC+)</td>
1637 <td>REQUIRED<sup>1</sup><br>(Android 4.1+)</td>
1638 <td>REQUIRED</td>
1639 <td>Support for mono/stereo/5.0/5.12 content with standard sampling rates from 16
1640to 48 kHz.</td>
1641 <td></td>
1642 </tr>
1643 <tr>
1644 <td>MPEG-4 HE AACv2</p>
1645
1646<p>Profile (enhanced AAC+)</td>
1647 <td> </td>
1648 <td>REQUIRED</td>
1649 <td>Support for mono/stereo/5.0/5.12 content with standard sampling rates from 16
1650to 48 kHz.</td>
1651 <td></td>
1652 </tr>
1653 <tr>
1654 <td>AAC ELD (enhanced low delay AAC)</td>
1655 <td>REQUIRED<sup>1</sup> </p>
1656
1657<p>(Android 4.1+)</td>
1658 <td>REQUIRED</p>
1659
1660<p>(Android 4.1+)</td>
1661 <td>Support for mono/stereo content with standard sampling rates from 16 to 48 kHz.</td>
1662 <td></td>
1663 </tr>
1664 <tr>
1665 <td>AMR-NB</td>
1666 <td>REQUIRED<sup>3</sup></td>
1667 <td>REQUIRED<sup>3</sup></td>
1668 <td>4.75 to 12.2 kbps sampled @ 8kHz</td>
1669 <td>3GPP (.3gp)</td>
1670 </tr>
1671 <tr>
1672 <td>AMR-WB</td>
1673 <td>REQUIRED<sup>3</sup></td>
1674 <td>REQUIRED<sup>3</sup></td>
1675 <td>9 rates from 6.60 kbit/s to 23.85 kbit/s sampled @ 16kHz</td>
1676 <td></td>
1677 </tr>
1678 <tr>
1679 <td>FLAC</td>
1680 <td></td>
1681 <td>REQUIRED <br>(Android 3.1+)</td>
1682 <td>Mono/Stereo (no multichannel). Sample rates up to 48 kHz (but up to 44.1 kHz is
1683recommended on devices with 44.1 kHz output, as the 48 to 44.1 kHz downsampler
1684does not include a low-pass filter). 16-bit recommended; no dither applied for
168524-bit.</td>
1686 <td>FLAC (.flac) only</td>
1687 </tr>
1688 <tr>
1689 <td>MP3</td>
1690 <td></td>
1691 <td>REQUIRED</td>
1692 <td>Mono/Stereo 8-320Kbps constant (CBR) or variable bitrate (VBR)</td>
1693 <td>MP3 (.mp3)</td>
1694 </tr>
1695 <tr>
1696 <td>MIDI</td>
1697 <td></td>
1698 <td>REQUIRED</td>
1699 <td>MIDI Type 0 and 1. DLS Version 1 and 2. XMF and Mobile XMF. Support for
1700ringtone formats RTTTL/RTX, OTA, and iMelody</td>
1701 <td><ul>
1702 <li class="table_list">Type 0 and 1 (.mid, .xmf, .mxmf)</li>
1703 <li class="table_list">RTTTL/RTX (.rtttl, .rtx)</li>
1704 <li class="table_list">OTA (.ota)</li>
1705 <li class="table_list">iMelody (.imy)</li></ul></td>
1706 </tr>
1707 <tr>
1708 <td>Vorbis</td>
1709 <td></td>
1710 <td>REQUIRED</td>
1711 <td></td>
1712 <td><ul>
1713 <li class="table_list">Ogg (.ogg)</li>
1714 <li class="table_list">Matroska (.mkv, Android 4.0+)</li></ul></td>
1715 </tr>
1716 <tr>
1717 <td>PCM/WAVE</td>
1718 <td>REQUIRED<sup>4</sup><br> (Android 4.1+)</td>
1719 <td>REQUIRED</td>
1720 <td>16-bit linear PCM (rates up to limit of hardware). Devices MUST support
1721sampling rates for raw PCM recording at 8000, 11025, 16000, and 44100 Hz
1722frequencies.</td>
1723 <td>WAVE (.wav)</td>
1724 </tr>
1725 <tr>
1726 <td>Opus</td>
1727 <td></td>
1728 <td>REQUIRED<br> (Android 5.0+)</td>
1729 <td></td>
1730 <td>Matroska (.mkv)</td>
1731 </tr>
1732</table>
1733
1734
1735<p class="table_footnote"> 1 Required for device implementations that define android.hardware.microphone
1736but optional for Android Watch device implementations.</p>
1737
1738<p class="table_footnote">2 Only downmix of 5.0/5.1 content is required; recording or rendering more than
17392 channels is optional.</p>
1740
1741<p class="table_footnote">3 Required for Android Handheld device implementations. </p>
1742
1743<p class="table_footnote">4 Required for device implementations that define android.hardware.microphone,
1744including Android Watch device implementations.</p>
1745
1746<h3 id="5_1_2_image_codecs">5.1.2. Image Codecs</h3>
1747
1748<table>
1749 <tr>
1750 <th>Format/Codec</th>
1751 <th>Encoder</th>
1752 <th>Decoder</th>
1753 <th>Details</th>
1754 <th>Supported File Types/Container Formats</th>
1755 </tr>
1756 <tr>
1757 <td>JPEG</td>
1758 <td>REQUIRED</td>
1759 <td>REQUIRED</td>
1760 <td>Base+progressive</td>
1761 <td>JPEG (.jpg)</td>
1762 </tr>
1763 <tr>
1764 <td>GIF</td>
1765 <td></td>
1766 <td>REQUIRED</td>
1767 <td></td>
1768 <td>GIF (.gif)</td>
1769 </tr>
1770 <tr>
1771 <td>PNG</td>
1772 <td>REQUIRED</td>
1773 <td>REQUIRED</td>
1774 <td></td>
1775 <td>PNG (.png)</td>
1776 </tr>
1777 <tr>
1778 <td>BMP</td>
1779 <td></td>
1780 <td>REQUIRED</td>
1781 <td></td>
1782 <td>BMP (.bmp)</td>
1783 </tr>
1784 <tr>
1785 <td>WebP</td>
1786 <td>REQUIRED</td>
1787 <td>REQUIRED</td>
1788 <td></td>
1789 <td>WebP (.webp)</td>
1790 </tr>
1791</table>
1792
1793
1794<h3 id="5_1_3_video_codecs">5.1.3. Video Codecs</h3>
1795
1796<p>Video codecs are optional for Android Watch device implementations.</p>
1797
1798<table>
1799 <tr>
1800 <th>Format/Codec</th>
1801 <th>Encoder</th>
1802 <th>Decoder</th>
1803 <th>Details</th>
1804 <th>Supported File Types/<br>Container Formats</th>
1805 </tr>
1806 <tr>
1807 <td>H.263</td>
1808 <td>REQUIRED<sup>1</sup></td>
1809 <td>REQUIRED<sup>2</sup></td>
1810 <td></td>
1811 <td><ul>
1812 <li class="table_list">3GPP (.3gp)</li>
1813 <li class="table_list">MPEG-4 (.mp4)</li></ul></td>
1814 </tr>
1815 <tr>
1816 <td>H.264 AVC</td>
1817 <td>REQUIRED<sup>2</sup></td>
1818 <td>REQUIRED<sup>2</sup></td>
1819 <td>See <a href="#5_2_video_encoding">section 5.2 </a>and <a href="#5_3_video_decoding">5.3</a> for details</td>
1820 <td><ul>
1821 <li class="table_list">3GPP (.3gp)</li>
1822 <li class="table_list">MPEG-4 (.mp4)</li>
1823 <li class="table_list">MPEG-TS (.ts, AAC audio only, not seekable, Android 3.0+)</li></ul></td>
1824 </tr>
1825 <tr>
1826 <td>H.265 HEVC</td>
1827 <td></td>
1828 <td>REQUIRED<sup>5</sup></td>
1829 <td>See <a href="#5_3_video_decoding">section 5.3</a> for details</td>
1830 <td>MPEG-4 (.mp4)</td>
1831 </tr>
1832 <tr>
1833 <td>MPEG-4 SP</td>
1834 <td></td>
1835 <td>REQUIRED<sup>2</sup></td>
1836 <td></td>
1837 <td>3GPP (.3gp)</td>
1838 </tr>
1839 <tr>
1840 <td>VP83</td>
1841 <td>REQUIRED<sup>2</sup></p>
1842
1843<p>(Android 4.3+)</td>
1844 <td>REQUIRED<sup>2</sup></p>
1845
1846<p>(Android 2.3.3+)</td>
1847 <td>See <a href="#5_2_video_encoding">section 5.2</a> and <a href="#5_3_video_decoding">5.3</a> for details</td>
1848 <td><ul>
1849 <li class="table_list">WebM (.webm) [<a href="http://www.webmproject.org/">Resources, 110</a></li>
1850 <li class="table_list">Matroska (.mkv, Android 4.0+)4</li></ul></td>
1851 </tr>
1852 <tr>
1853 <td>VP9</td>
1854 <td></td>
1855 <td>REQUIRED<sup>2</sup><br> (Android 4.4+)</td>
1856 <td>See <a href="#5_3_video_decoding">section 5.3</a> for details</td>
1857 <td><ul>
1858 <li class="table_list">WebM (.webm) [<a href="http://www.webmproject.org/">Resources, 110</a>]</li>
1859 <li class="table_list">Matroska (.mkv, Android 4.0+)4</li></ul></td>
1860 </tr>
1861</table>
1862
1863
1864<p class="table_footnote">1 Required for device implementations that include camera hardware and define
1865android.hardware.camera or android.hardware.camera.front.</p>
1866
1867<p class="table_footnote">2 Required for device implementations except Android Watch devices. </p>
1868
1869<p class="table_footnote">3 For acceptable quality of web video streaming and video-conference services,
1870device implementations SHOULD use a hardware VP8 codec that meets the
1871requirements in [<a href="http://www.webmproject.org/hardware/rtc-coding-requirements/">Resources, 51</a>].</p>
1872
1873<p class="table_footnote">4 Device implementations SHOULD support writing Matroska WebM files.</p>
1874
1875<p class="table_footnote">5 Strongly recommended for Android Automotive, optional for Android Watch, and required for all other device types.</p>
1876
1877<h2 id="5_2_video_encoding">5.2. Video Encoding</h2>
1878
1879<div class="note">
1880<p>Video codecs are optional for Android Watch device implementations.</p>
1881</div>
1882
1883
1884<p>Android device implementations with H.264 codec support, MUST support Baseline
1885Profile Level 3 and the following SD (Standard Definition) video encoding
1886profiles and SHOULD support Main Profile Level 4 and the following HD (High
1887Definition) video encoding profiles. Android Television devices are STRONGLY
1888RECOMMENDED to encode HD 1080p video at 30 fps.</p>
1889<table>
1890 <tr>
1891 <th></th>
1892 <th>SD (Low quality)</th>
1893 <th>SD (High quality)</th>
1894 <th>HD 720p1</th>
1895 <th>HD 1080p1</th>
1896 </tr>
1897 <tr>
1898 <th>Video resolution</th>
1899 <td>320 x 240 px</td>
1900 <td>720 x 480 px</td>
1901 <td>1280 x 720 px</td>
1902 <td>1920 x 1080 px</td>
1903 </tr>
1904 <tr>
1905 <th>Video frame rate</th>
1906 <td>20 fps</td>
1907 <td>30 fps</td>
1908 <td>30 fps</td>
1909 <td>30 fps</td>
1910 </tr>
1911 <tr>
1912 <th>Video bitrate</th>
1913 <td>384 Kbps</td>
1914 <td>2 Mbps</td>
1915 <td>4 Mbps</td>
1916 <td>10 Mbps</td>
1917 </tr>
1918</table>
1919
1920
1921<p class="table_footnote">1 When supported by hardware, but STRONGLY RECOMMENDED for Android Television
1922devices.</p>
1923
1924<p>Android device implementations with VP8 codec support MUST support the SD video
1925encoding profiles and SHOULD support the following HD (High Definition) video
1926encoding profiles.</p>
1927<table>
1928 <tr>
1929 <th></th>
1930 <th>SD (Low quality)</th>
1931 <th>SD (High quality)</th>
1932 <th>HD 720p1</th>
1933 <th>HD 1080p1</th>
1934 </tr>
1935 <tr>
1936 <th>Video resolution</th>
1937 <td>320 x 180 px</td>
1938 <td>640 x 360 px</td>
1939 <td>1280 x 720 px</td>
1940 <td>1920 x 1080 px</td>
1941 </tr>
1942 <tr>
1943 <th>Video frame rate</th>
1944 <td>30 fps</td>
1945 <td>30 fps</td>
1946 <td>30 fps</td>
1947 <td>30 fps</td>
1948 </tr>
1949 <tr>
1950 <th>Video bitrate</th>
1951 <td>800 Kbps </td>
1952 <td>2 Mbps</td>
1953 <td>4 Mbps</td>
1954 <td>10 Mbps</td>
1955 </tr>
1956</table>
1957
1958<p class="table_footnote">1 When supported by hardware.</p>
1959
1960<h2 id="5_3_video_decoding">5.3. Video Decoding</h2>
1961
1962<div class="note">
1963<p>Video codecs are optional for Android Watch device implementations.</p>
1964</div>
1965
1966
1967<p>Device implementations MUST support dynamic video resolution switching within
1968the same stream for VP8, VP9, H.264, and H.265 codecs.</p>
1969
1970<p>Android device implementations with H.264 decoders, MUST support Baseline
1971Profile Level 3 and the following SD video decoding profiles and SHOULD support
1972the HD decoding profiles. Android Television devices MUST support High Profile
1973Level 4.2 and the HD 1080p decoding profile.</p>
1974<table>
1975 <tr>
1976 <th></th>
1977 <th>SD (Low quality)</th>
1978 <th>SD (High quality)</th>
1979 <th>HD 720p1</th>
1980 <th>HD 1080p1</th>
1981 </tr>
1982 <tr>
1983 <th>Video resolution</th>
1984 <td>320 x 240 px</td>
1985 <td>720 x 480 px</td>
1986 <td>1280 x 720 px</td>
1987 <td>1920 x 1080 px</td>
1988 </tr>
1989 <tr>
1990 <th>Video frame rate</th>
1991 <td>30 fps</td>
1992 <td>30 fps</td>
1993 <td>30 fps / 60 fps2</td>
1994 <td>30 fps / 60 fps2</td>
1995 </tr>
1996 <tr>
1997 <th>Video bitrate</th>
1998 <td>800 Kbps </td>
1999 <td>2 Mbps</td>
2000 <td>8 Mbps</td>
2001 <td>20 Mbps</td>
2002 </tr>
2003</table>
2004
2005
2006<p class="table_footnote">1 Required for Android Television device implementations, but for other device
2007types only when supported by hardware.</p>
2008
2009<p class="table_footnote">2 Required for Android Television device implementations.</p>
2010
2011<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
2012decoding profiles. Android Television devices MUST support the HD 1080p
2013decoding profile. </p>
2014<table>
2015 <tr>
2016 <th></th>
2017 <th>SD (Low quality)</th>
2018 <th>SD (High quality)</th>
2019 <th>HD 720p1</th>
2020 <th>HD 1080p1</th>
2021 </tr>
2022 <tr>
2023 <th>Video resolution</th>
2024 <td>320 x 180 px</td>
2025 <td>640 x 360 px</td>
2026 <td>1280 x 720 px</td>
2027 <td>1920 x 1080 px</td>
2028 </tr>
2029 <tr>
2030 <th>Video frame rate</th>
2031 <td>30 fps</td>
2032 <td>30 fps</td>
2033 <td>30 fps / 60 fps2</td>
2034 <td>30 / 60 fps2</td>
2035 </tr>
2036 <tr>
2037 <th>Video bitrate</th>
2038 <td>800 Kbps </td>
2039 <td>2 Mbps</td>
2040 <td>8 Mbps</td>
2041 <td>20 Mbps</td>
2042 </tr>
2043</table>
2044
2045
2046<p class="table_footnote">1 Required for Android Television device implementations, but for other type of
2047devices only when supported by hardware.</p>
2048
2049<p class="table_footnote">2 Required for Android Television device implementations.</p>
2050
2051<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
2052HD decoding profiles. Android Television devices are STRONGLY RECOMMENDED to
2053support the HD 1080p decoding profile and SHOULD support the UHD decoding
2054profile. When the UHD video decoding profile is supported, it MUST support 8
2055bit color depth.</p>
2056<table>
2057 <tr>
2058 <th></th>
2059 <th>SD (Low quality)</th>
2060 <th>SD (High quality)</th>
2061 <th>HD 720p 1</th>
2062 <th>HD 1080p 2</th>
2063 <th>UHD 2</th>
2064 </tr>
2065 <tr>
2066 <th>Video resolution</th>
2067 <td>320 x 180 px</td>
2068 <td>640 x 360 px</td>
2069 <td>1280 x 720 px</td>
2070 <td>1920 x 1080 px</td>
2071 <td>3840 x 2160 px</td>
2072 </tr>
2073 <tr>
2074 <th>Video frame rate</th>
2075 <td>30 fps</td>
2076 <td>30 fps</td>
2077 <td>30 fps</td>
2078 <td>30 fps</td>
2079 <td>30 fps</td>
2080 </tr>
2081 <tr>
2082 <th>Video bitrate</th>
2083 <td>600 Kbps </td>
2084 <td>1.6 Mbps</td>
2085 <td>4 Mbps</td>
2086 <td>10 Mbps</td>
2087 <td>20 Mbps</td>
2088 </tr>
2089</table>
2090
2091
2092<p class="table_footnote">1 Required for Android Television device implementations, but for other type of
2093devices only when supported by hardware.</p>
2094
2095<p class="table_footnote">2 STRONGLY RECOMMENDED for Android Television device implementations when
2096supported by hardware.</p>
2097
2098<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
2099decoding profiles and SHOULD support the HD decoding profiles. Android
2100Television devices MUST support the Main Profile Level 4.1 Main tier and the HD
21011080p decoding profile and SHOULD support Main10 Level 5 Main Tier profile and
2102the UHD decoding profile.</p>
2103<table>
2104 <tr>
2105 <th></th>
2106 <th>SD (Low quality)</th>
2107 <th>SD (High quality)</th>
2108 <th>HD 720p </strong>1 </td>
2109 <th>HD 1080p </strong>1 </td>
2110 <th>UHD </strong>2</td>
2111 </tr>
2112 <tr>
2113 <th>Video resolution</th>
2114 <td>352 x 288 px</td>
2115 <td>640 x 360 px</td>
2116 <td>1280 x 720 px</td>
2117 <td>1920 x 1080 px</td>
2118 <td>3840 x 2160 px</td>
2119 </tr>
2120 <tr>
2121 <th>Video frame rate</th>
2122 <td>30 fps</td>
2123 <td>30 fps</td>
2124 <td>30 fps</td>
2125 <td>30 fps</td>
2126 <td>30 fps</td>
2127 </tr>
2128 <tr>
2129 <th>Video bitrate</th>
2130 <td>600 Kbps </td>
2131 <td>1.6 Mbps</td>
2132 <td>4 Mbps</td>
2133 <td>10 Mbps</td>
2134 <td>20 Mbps</td>
2135 </tr>
2136</table>
2137
2138
2139<p class="table_footnote">1 Required for Android Television device implementation, but for other type of
2140devices only when supported by hardware.</p>
2141
2142<p class="table_footnote">2 Required for Android Television device implementations when supported by
2143hardware.</p>
2144
2145<h2 id="5_4_audio_recording">5.4. Audio Recording</h2>
2146
2147
2148<p>While some of the requirements outlined in this section are stated as SHOULD
2149since Android 4.3, the Compatibility Definition for a future version is planned
2150to 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
2151compatibility when upgraded to the future version.</p>
2152
2153<h3 id="5_4_1_raw_audio_capture">5.4.1. Raw Audio Capture</h3>
2154
2155
2156<p>Device implementations that declare android.hardware.microphone MUST allow
2157capture of raw audio content with the following characteristics:</p>
2158
2159<ul>
2160 <li><strong>Format</strong>: Linear PCM, 16-bit
2161 <li><strong>Sampling rates</strong>: 8000, 11025, 16000, 44100
2162 <li><strong>Channels</strong>: Mono
2163</ul>
2164
2165<p>Device implementations that declare android.hardware.microphone SHOULD allow
2166capture of raw audio content with the following characteristics:</p>
2167
2168<ul>
2169 <li><strong>Format</strong>: Linear PCM, 16-bit
2170 <li><strong>Sampling rates</strong>: 22050, 48000
2171 <li><strong>Channels</strong>: Stereo
2172</ul>
2173
2174<h3 id="5_4_2_capture_for_voice_recognition">5.4.2. Capture for Voice Recognition</h3>
2175
2176
2177<p>In addition to the above recording specifications, when an application has
2178started recording an audio stream using the
2179android.media.MediaRecorder.AudioSource.VOICE_RECOGNITION audio source:</p>
2180
2181<ul>
2182 <li>The device SHOULD exhibit approximately flat amplitude versus frequency
2183characteristics: specifically, ±3 dB, from 100 Hz to 4000 Hz.
2184 <li>Audio input sensitivity SHOULD be set such that a 90 dB sound power level (SPL)
2185source at 1000 Hz yields RMS of 2500 for 16-bit samples.
2186 <li>PCM amplitude levels SHOULD linearly track input SPL changes over at least a 30
2187dB range from -18 dB to +12 dB re 90 dB SPL at the microphone.
2188 <li>Total harmonic distortion SHOULD be less than 1% for 1Khz at 90 dB SPL input
2189level at the microphone.
2190 <li>Noise reduction processing, if present, MUST be disabled.
2191 <li>Automatic gain control, if present, MUST be disabled
2192</ul>
2193
2194<p>If the platform supports noise suppression technologies tuned for speech
2195recognition, the effect MUST be controllable from the
2196android.media.audiofx.NoiseSuppressor API. Moreover, the UUID field for the
2197noise suppressor&rsquo;s effect descriptor MUST uniquely identify each implementation
2198of the noise suppression technology.</p>
2199
2200<h3 id="5_4_3_capture_for_rerouting_of_playback">5.4.3. Capture for Rerouting of Playback</h3>
2201
2202
2203<p>The android.media.MediaRecorder.AudioSource class includes the REMOTE_SUBMIX
2204audio source. Devices that declare android.hardware.audio.output MUST properly
2205implement the REMOTE_SUBMIX audio source so that when an application uses the
2206android.media.AudioRecord API to record from this audio source, it can capture
2207a mix of all audio streams except for the following:</p>
2208
2209<ul>
2210 <li>STREAM_RING
2211 <li>STREAM_ALARM
2212 <li>STREAM_NOTIFICATION
2213</ul>
2214
2215<h2 id="5_5_audio_playback">5.5. Audio Playback</h2>
2216
2217
2218<p>Device implementations that declare android.hardware.audio.output MUST conform
2219to the requirements in this section.</p>
2220
2221<h3 id="5_5_1_raw_audio_playback">5.5.1. Raw Audio Playback</h3>
2222
2223
2224<p>The device MUST allow playback of raw audio content with the following
2225characteristics:</p>
2226
2227<ul>
2228 <li><strong>Format</strong>: Linear PCM, 16-bit</li>
2229 <li><strong>Sampling rates</strong>: 8000, 11025, 16000, 22050, 32000, 44100</li>
2230 <li><strong>Channels</strong>: Mono, Stereo</li>
2231</ul>
2232
2233<p>The device SHOULD allow playback of raw audio content with the following
2234characteristics:</p>
2235
2236<ul>
2237 <li><strong>Sampling rates</strong>: 24000, 48000</li>
2238</ul>
2239
2240<h3 id="5_5_2_audio_effects">5.5.2. Audio Effects</h3>
2241
2242
2243<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
2244android.hardware.audio.output:</p>
2245
2246<ul>
2247 <li>MUST support the EFFECT_TYPE_EQUALIZER and EFFECT_TYPE_LOUDNESS_ENHANCER
2248implementations controllable through the AudioEffect subclasses Equalizer,
2249LoudnessEnhancer.</li>
2250 <li>MUST support the visualizer API implementation, controllable through the
2251Visualizer class.</li>
2252 <li>SHOULD support the EFFECT_TYPE_BASS_BOOST, EFFECT_TYPE_ENV_REVERB,
2253EFFECT_TYPE_PRESET_REVERB, and EFFECT_TYPE_VIRTUALIZER implementations
2254controllable through the AudioEffect sub-classes BassBoost,
2255EnvironmentalReverb, PresetReverb, and Virtualizer.</li>
2256</ul>
2257
2258<h3 id="5_5_3_audio_output_volume">5.5.3. Audio Output Volume</h3>
2259
2260
2261<p>Android Television device implementations MUST include support for system
2262Master Volume and digital audio output volume attenuation on supported outputs,
2263except for compressed audio passthrough output (where no audio decoding is done
2264on the device).</p>
2265
2266<h2 id="5_6_audio_latency">5.6. Audio Latency</h2>
2267
2268
2269<p>Audio latency is the time delay as an audio signal passes through a system.
2270Many classes of applications rely on short latencies, to achieve real-time
2271sound effects.</p>
2272
2273<p>For the purposes of this section, use the following definitions:</p>
2274
2275<ul>
2276 <li><strong>output latency</strong>. The interval between when an application writes a frame of PCM-coded data and
2277when the corresponding sound can be heard by an external listener or observed
2278by a transducer.</li>
2279 <li><strong>cold output latency</strong>. The output latency for the first frame, when the audio output system has been
2280idle and powered down prior to the request.</li>
2281 <li><strong>continuous output latency</strong>. The output latency for subsequent frames, after the device is playing audio.</li>
2282 <li><strong>input latency</strong>. The interval between when an external sound is presented to the device and
2283when an application reads the corresponding frame of PCM-coded data.</li>
2284 <li><strong>cold input latency</strong>. The sum of lost input time and the input latency for the first frame, when the
2285audio input system has been idle and powered down prior to the request.</li>
2286 <li><strong>continuous input latency</strong>. The input latency for subsequent frames, while the device is capturing audio.</li>
2287 <li><strong>cold output jitter</strong>. The variance among separate measurements of cold output latency values.</li>
2288 <li><strong>cold input jitter</strong>. The variance among separate measurements of cold input latency values.</li>
2289 <li><strong>continuous round-trip latency</strong>. The sum of continuous input latency plus continuous output latency plus 5
2290milliseconds.</li>
2291 <li><strong>OpenSL ES PCM buffer queue API</strong>. The set of PCM-related OpenSL ES APIs within Android NDK; see
2292NDK_root/docs/opensles/index.html.</li>
2293</ul>
2294
2295<p>Device implementations that declare android.hardware.audio.output SHOULD meet
2296or exceed these audio output requirements:</p>
2297
2298<ul>
2299 <li>cold output latency of 100 milliseconds or less</li>
2300 <li>continuous output latency of 45 milliseconds or less</li>
2301 <li>minimize the cold output jitter</li>
2302</ul>
2303
2304<p>If a device implementation meets the requirements of this section after any
2305initial calibration when using the OpenSL ES PCM buffer queue API, for
2306continuous output latency and cold output latency over at least one supported
2307audio output device, it MAY report support for low-latency audio, by reporting
2308the feature android.hardware.audio.low_latency via the
2309android.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
2310MUST NOT report support for low-latency audio.</p>
2311
2312<p>Device implementations that include android.hardware.microphone SHOULD meet
2313these input audio requirements:</p>
2314
2315<ul>
2316 <li>cold input latency of 100 milliseconds or less</li>
2317 <li>continuous input latency of 30 milliseconds or less</li>
2318 <li>continuous round-trip latency of 50 milliseconds or less</li>
2319 <li>minimize the cold input jitter</li>
2320</ul>
2321
2322<h2 id="5_7_network_protocols">5.7. Network Protocols</h2>
2323
2324
2325<p>Devices MUST support the media network protocols for audio and video playback
2326as 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>
2327
2328<ul>
2329 <li>RTSP (RTP, SDP)</li>
2330 <li>HTTP(S) progressive streaming</li>
2331 <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>
2332</ul>
2333
2334<h2 id="5_8_secure_media">5.8. Secure Media</h2>
2335
2336
2337<p>Device implementations that support secure video output and are capable of
2338supporting secure surfaces MUST declare support for Display.FLAG_SECURE. Device
2339implementations that declare support for Display.FLAG_SECURE, if they support a
2340wireless display protocol, MUST secure the link with a cryptographically strong
2341mechanism such as HDCP 2.x or higher for Miracast wireless displays. Similarly
2342if they support a wired external display, the device implementations MUST
2343support HDCP 1.2 or higher. Android Television device implementations MUST
2344support HDCP 2.2 for devices supporting 4K resolution and HDCP 1.4 or above for
2345lower resolutions. The upstream Android open source implementation includes
2346support for wireless (Miracast) and wired (HDMI) displays that satisfies this
2347requirement.</p>
2348
2349<h1 id="6_developer_tools_and_options_compatibility">6. Developer Tools and Options Compatibility</h1>
2350
2351
2352<h2 id="6_1_developer_tools">6.1. Developer Tools</h2>
2353
2354
2355<p>Device implementations MUST support the Android Developer Tools provided in the
2356Android SDK. Android compatible devices MUST be compatible with:</p>
2357
2358<ul>
2359 <li><strong>Android Debug Bridge (adb)</strong> [<a href="http://developer.android.com/tools/help/adb.html">Resources, 55</a>]</li>
2360</ul>
2361
2362<p>Device implementations MUST support all adb functions as documented in the
2363Android 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
2364user-accessible mechanism to turn on the Android Debug Bridge. If a device
2365implementation omits USB peripheral mode, it MUST implement the Android Debug
2366Bridge via local-area network (such as Ethernet or 802.11). </p>
2367
2368<p>Android includes support for secure adb. Secure adb enables adb on known
2369authenticated hosts. Device implementations MUST support secure adb.</p>
2370
2371<ul>
2372 <li><strong>Dalvik Debug Monitor Service (ddms)</strong> [<a href="http://developer.android.com/tools/debugging/ddms.html">Resources, 57</a>]</li>
2373</ul>
2374
2375<p>Device implementations MUST support all ddms features as documented in the
2376Android SDK. As ddms uses adb, support for ddms SHOULD be inactive by default,
2377but MUST be supported whenever the user has activated the Android Debug Bridge,
2378as above.</p>
2379
2380<ul>
2381 <li><strong>Monkey</strong> [<a href="http://developer.android.com/tools/help/monkey.html">Resources, 58</a>]</li>
2382</ul>
2383
2384<p>Device implementations MUST include the Monkey framework, and make it available
2385for applications to use.</p>
2386
2387<ul>
2388 <li><strong>SysTrace</strong> [<a href="http://developer.android.com/tools/help/systrace.html">Resources, 59</a>]</li>
2389</ul>
2390
2391<p>Device implementations MUST support systrace tool as documented in the Android
2392SDK. Systrace must be inactive by default, and there MUST be a user-accessible
2393mechanism to turn on Systrace.</p>
2394
2395<p>Most Linux-based systems and Apple Macintosh systems recognize Android devices
2396using the standard Android SDK tools, without additional support; however
2397Microsoft Windows systems typically require a driver for new Android devices.
2398(For instance, new vendor IDs and sometimes new device IDs require custom USB
2399drivers for Windows systems.) If a device implementation is unrecognized by the
2400adb tool as provided in the standard Android SDK, device implementers MUST
2401provide Windows drivers allowing developers to connect to the device using the
2402adb protocol. These drivers MUST be provided for Windows XP, Windows Vista,
2403Windows 7, Windows 8, and Windows 9 in both 32-bit and 64-bit versions.</p>
2404
2405<h2 id="6_2_developer_options">6.2. Developer Options</h2>
2406
2407
2408<p>Android includes support for developers to configure application
2409development-related settings. Device implementations MUST honor the
2410android.settings.APPLICATION_DEVELOPMENT_SETTINGS intent to show application
2411development-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
2412default and enables users to launch Developer Options after pressing seven (7)
2413times on the <strong>Settings</strong> > <strong>About Device</strong> > <strong>Build Number</strong> menu item. Device implementations MUST provide a consistent experience for
2414Developer Options. Specifically, device implementations MUST hide Developer
2415Options by default and MUST provide a mechanism to enable Developer Options
2416that is consistent with the upstream Android implementation.</p>
2417
2418<h1 id="7_hardware_compatibility">7. Hardware Compatibility</h1>
2419
2420
2421<p>If a device includes a particular hardware component that has a corresponding
2422API for third-party developers, the device implementation MUST implement that
2423API as described in the Android SDK documentation. If an API in the SDK
2424interacts with a hardware component that is stated to be optional and the
2425device implementation does not possess that component:</p>
2426
2427<ul>
2428 <li>Complete class definitions (as documented by the SDK) for the component APIs
2429MUST still be presented.
2430 <li>The API&rsquo;s behaviors MUST be implemented as no-ops in some reasonable fashion.
2431 <li>API methods MUST return null values where permitted by the SDK documentation.
2432 <li>API methods MUST return no-op implementations of classes where null values are
2433not permitted by the SDK documentation.
2434 <li>API methods MUST NOT throw exceptions not documented by the SDK documentation.
2435</ul>
2436
2437<p>A typical example of a scenario where these requirements apply is the telephony
2438API: even on non-phone devices, these APIs must be implemented as reasonable
2439no-ops.</p>
2440
2441<p>Device implementations MUST consistently report accurate hardware configuration
2442information via the getSystemAvailableFeatures() and hasSystemFeature(String)
2443methods on the android.content.pm.PackageManager class for the same build
2444fingerprint. [<a href="http://developer.android.com/reference/android/content/pm/PackageManager.html">Resources, 53]</a></p>
2445
2446<h2 id="7_1_display_and_graphics">7.1. Display and Graphics</h2>
2447
2448
2449<p>Android includes facilities that automatically adjust application assets and UI
2450layouts appropriately for the device, to ensure that third-party applications
2451run 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
2452this section.</p>
2453
2454<p>The units referenced by the requirements in this section are defined as
2455follows:</p>
2456
2457<ul>
2458 <li><strong>physical diagonal size</strong>. The distance in inches between two opposing corners of the illuminated portion
2459of the display.</li>
2460 <li><strong>dots per inch (dpi)</strong>. The number of pixels encompassed by a linear horizontal or vertical span of
24611&rdquo;. Where dpi values are listed, both horizontal and vertical dpi must fall
2462within the range.</li>
2463 <li><strong>aspect ratio</strong>. The ratio of the pixels of the longer dimension
2464 to the shorter dimension of the screen. For example, a display of 480x854 pixels
2465 would be 854/480 = 1.779, or roughly &ldquo;16:9&rdquo;.</li>
2466 <li><strong>density-independent pixel (dp)</strong> The virtual pixel unit normalized to a 160 dpi screen, calculated as: pixels =
2467dps * (density/160).</li>
2468</ul>
2469
2470<h3 id="7_1_1_screen_configuration">7.1.1. Screen Configuration</h3>
2471
2472
2473<h4 id="7_1_1_1_screen_size">7.1.1.1. Screen Size</h4>
2474
2475<div class="note">
2476<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>
2477</div>
2478
2479<p>The Android UI framework supports a variety of different screen sizes, and
2480allows applications to query the device screen size (aka &ldquo;screen layout") via
2481android.content.res.Configuration.screenLayout with the SCREENLAYOUT_SIZE_MASK.
2482Device implementations MUST report the correct screen size as defined in the
2483Android 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
2484implementations MUST report the correct screen size according to the following
2485logical density-independent pixel (dp) screen dimensions.</p>
2486
2487<ul>
2488 <li>Devices MUST have screen sizes of at least 426 dp x 320 dp (&lsquo;small&rsquo;), unless it
2489is an Android Watch device.</li>
2490 <li>Devices that report screen size &lsquo;normal&rsquo; MUST have screen sizes of at least 480
2491dp x 320 dp.</li>
2492 <li>Devices that report screen size &lsquo;large&rsquo; MUST have screen sizes of at least 640
2493dp x 480 dp.</li>
2494 <li>Devices that report screen size &lsquo;xlarge&rsquo; MUST have screen sizes of at least 960
2495dp x 720 dp.</li>
2496</ul>
2497
2498<p>In addition, </p>
2499
2500<ul>
2501 <li>Android Watch devices MUST have a screen with the physical diagonal size in the
2502range from 1.1 to 2.5 inches.</li>
2503 <li>Other types of Android device implementations, with a physically integrated
2504screen, MUST have a screen at least 2.5 inches in physical diagonal size.</li>
2505</ul>
2506
2507<p>Devices MUST NOT change their reported screen size at any time.</p>
2508
2509<p>Applications optionally indicate which screen sizes they support via the
2510<supports-screens> attribute in the AndroidManifest.xml file. Device
2511implementations MUST correctly honor applications' stated support for small,
2512normal, large, and xlarge screens, as described in the Android SDK
2513documentation.</p>
2514
2515<h4 id="7_1_1_2_screen_aspect_ratio">7.1.1.2. Screen Aspect Ratio</h4>
2516
2517<div class="note">
2518<p>Android Watch devices MAY have an aspect ratio of 1.0 (1:1).</p>
2519</div>
2520
2521
2522<p>The screen aspect ratio MUST be a value from 1.3333 (4:3) to 1.86 (roughly
252316:9), but Android Watch devices MAY have an aspect ratio of 1.0 (1:1) because
2524such a device implementation will use a UI_MODE_TYPE_WATCH as the
2525android.content.res.Configuration.uiMode.</p>
2526
2527<h4 id="7_1_1_3_screen_density">7.1.1.3. Screen Density</h4>
2528
2529
2530<p>The Android UI framework defines a set of standard logical densities to help
2531application developers target application resources. Device implementations
2532MUST report only one of the following logical Android framework densities
2533through the android.util.DisplayMetrics APIs, and MUST execute applications at
2534this standard density and MUST NOT change the value at at any time for the
2535default display.</p>
2536
2537<ul>
2538 <li>120 dpi (ldpi)</li>
2539 <li>160 dpi (mdpi)</li>
2540 <li>213 dpi (tvdpi)</li>
2541 <li>240 dpi (hdpi)</li>
2542 <li>280 dpi (280dpi)</li>
2543 <li>320 dpi (xhdpi)</li>
2544 <li>400 dpi (400dpi)</li>
2545 <li>480 dpi (xxhdpi)</li>
2546 <li>560 dpi (560dpi)</li>
2547 <li>640 dpi (xxxhdpi)</li>
2548</ul>
2549
2550<p>Device implementations SHOULD define the standard Android framework density
2551that is numerically closest to the physical density of the screen, unless that
2552logical density pushes the reported screen size below the minimum supported. If
2553the standard Android framework density that is numerically closest to the
2554physical density results in a screen size that is smaller than the smallest
2555supported compatible screen size (320 dp width), device implementations SHOULD
2556report the next lowest standard Android framework density.</p>
2557
2558<h3 id="7_1_2_display_metrics">7.1.2. Display Metrics</h3>
2559
2560
2561<p>Device implementations MUST report correct values for all display metrics
2562defined 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
2563external screen is used as the default display.</p>
2564
2565<h3 id="7_1_3_screen_orientation">7.1.3. Screen Orientation</h3>
2566
2567
2568<p>Devices MUST report which screen orientations they support
2569(android.hardware.screen.portrait and/or android.hardware.screen.landscape) and
2570MUST report at least one supported orientation. For example, a device with a
2571fixed orientation landscape screen, such as a television or laptop, SHOULD only
2572report android.hardware.screen.landscape.</p>
2573
2574<p>Devices that report both screen orientations MUST support dynamic orientation
2575by applications to either portrait or landscape screen orientation. That is,
2576the device must respect the application&rsquo;s request for a specific screen
2577orientation. Device implementations MAY select either portrait or landscape
2578orientation as the default.</p>
2579
2580<p>Devices MUST report the correct value for the device&rsquo;s current orientation,
2581whenever queried via the android.content.res.Configuration.orientation,
2582android.view.Display.getOrientation(), or other APIs.</p>
2583
2584<p>Devices MUST NOT change the reported screen size or density when changing
2585orientation.</p>
2586
2587<h3 id="7_1_4_2d_and_3d_graphics_acceleration">7.1.4. 2D and 3D Graphics Acceleration</h3>
2588
2589
2590<p>Device implementations MUST support both OpenGL ES 1.0 and 2.0, as embodied and
2591detailed in the Android SDK documentations. Device implementations SHOULD
2592support OpenGL ES 3.0 or 3.1 on devices capable of supporting it. Device
2593implementations MUST also support Android RenderScript, as detailed in the
2594Android SDK documentation [<a href="http://developer.android.com/guide/topics/renderscript/">Resources, 63</a>].</p>
2595
2596<p>Device implementations MUST also correctly identify themselves as supporting
2597OpenGL ES 1.0, OpenGL ES 2.0, OpenGL ES 3.0 or OpenGL 3.1. That is:</p>
2598
2599<ul>
2600 <li>The managed APIs (such as via the GLES10.getString()method MUST report support
2601for OpenGL ES 1.0 and OpenGL ES 2.0.</li>
2602 <li>The native C/C++ OpenGL APIs (APIs available to apps via libGLES_v1CM.so,
2603libGLES_v2.so, or libEGL.so) MUST report support for OpenGL ES 1.0 and OpenGL
2604ES 2.0.</li>
2605 <li>Device implementations that declare support for OpenGL ES 3.0 or 3.1 MUST
2606support the corresponding managed APIs and include support for native C/C++
2607APIs. On device implementations that declare support for OpenGL ES 3.0 or 3.1,
2608libGLESv2.so MUST export the corresponding function symbols in addition to the
2609OpenGL ES 2.0 function symbols.</li>
2610</ul>
2611
2612<p>In addition to OpenGL ES 3.1, Android provides an extension pack with Java
2613interfaces [<a href="https://developer.android.com/reference/android/opengl/GLES31Ext.html">Resources, 64</a>] and native support for advanced graphics functionality such as tessellation
2614and the ASTC texture compression format. Android device implementations MAY
2615support this extension pack, and&mdash;only if fully implemented&mdash;MUST identify the
2616support through the android.hardware.opengles.aep feature flag.</p>
2617
2618<p>Also, device implementations MAY implement any desired OpenGL ES extensions.
2619However, device implementations MUST report via the OpenGL ES managed and
2620native APIs all extension strings that they do support, and conversely MUST NOT
2621report extension strings that they do not support.</p>
2622
2623<p>Note that Android includes support for applications to optionally specify that
2624they require specific OpenGL texture compression formats. These formats are
2625typically vendor-specific. Device implementations are not required by Android
2626to implement any specific texture compression format. However, they SHOULD
2627accurately report any texture compression formats that they do support, via the
2628getString() method in the OpenGL API.</p>
2629
2630<p>Android includes a mechanism for applications to declare that they want to
2631enable hardware acceleration for 2D graphics at the Application, Activity,
2632Window, or View level through the use of a manifest tag
2633android:hardwareAccelerated or direct API calls [<a href="http://developer.android.com/guide/topics/graphics/hardware-accel.html">Resources, 65</a>].</p>
2634
2635<p>Device implementations MUST enable hardware acceleration by default, and MUST
2636disable hardware acceleration if the developer so requests by setting
2637android:hardwareAccelerated="false&rdquo; or disabling hardware acceleration directly
2638through the Android View APIs.</p>
2639
2640<p>In addition, device implementations MUST exhibit behavior consistent with the
2641Android SDK documentation on hardware acceleration [<a href="http://developer.android.com/guide/topics/graphics/hardware-accel.html">Resources, 65</a>].</p>
2642
2643<p>Android includes a TextureView object that lets developers directly integrate
2644hardware-accelerated OpenGL ES textures as rendering targets in a UI hierarchy.
2645Device implementations MUST support the TextureView API, and MUST exhibit
2646consistent behavior with the upstream Android implementation.</p>
2647
2648<p>Android includes support for EGL_ANDROID_RECORDABLE, an EGLConfig attribute
2649that indicates whether the EGLConfig supports rendering to an ANativeWindow
2650that records images to a video. Device implementations MUST support
2651EGL_ANDROID_RECORDABLE extension [<a href="https://www.khronos.org/registry/egl/extensions/ANDROID/EGL_ANDROID_recordable.txt">Resources, 66</a>].</p>
2652
2653<h3 id="7_1_5_legacy_application_compatibility_mode">7.1.5. Legacy Application Compatibility Mode</h3>
2654
2655
2656<p>Android specifies a &ldquo;compatibility mode&rdquo; in which the framework operates in a
2657'normal' screen size equivalent (320dp width) mode for the benefit of legacy
2658applications not developed for old versions of Android that pre-date
2659screen-size independence.</p>
2660
2661<ul>
2662<li>Android Automotive does not support legacy compatibility mode.</li>
2663<li>All other device implementations MUST include support for legacy application
2664compatibility mode as implemented by the upstream Android open source code. That
2665is, device implementations MUST NOT alter the triggers or thresholds at which
2666compatibility mode is activated, and MUST NOT alter the behavior of the
2667compatibility mode itself.</li>
2668</ul>
2669
2670<h3 id="7_1_6_screen_technology">7.1.6. Screen Technology</h3>
2671
2672
2673<p>The Android platform includes APIs that allow applications to render rich
2674graphics to the display. Devices MUST support all of these APIs as defined by
2675the Android SDK unless specifically allowed in this document. </p>
2676
2677<ul>
2678 <li>Devices MUST support displays capable of rendering 16-bit color graphics and
2679SHOULD support displays capable of 24-bit color graphics.</li>
2680 <li>Devices MUST support displays capable of rendering animations.</li>
2681 <li>The display technology used MUST have a pixel aspect ratio (PAR) between 0.9
2682and 1.15. That is, the pixel aspect ratio MUST be near square (1.0) with a 10 ~
268315% tolerance.</li>
2684</ul>
2685
2686<h3 id="7_1_7_external_displays">7.1.7. Secondary Displays</h3>
2687
2688
2689<p>Android includes support for secondary display to enable media sharing
2690capabilities and developer APIs for accessing external displays. If a device
2691supports an external display either via a wired, wireless, or an embedded
2692additional display connection then the device implementation MUST implement the
2693display 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>
2694
2695<h2 id="7_2_input_devices">7.2. Input Devices</h2>
2696
2697<p>Devices MUST support a touchscreen or meet the requirements listed in 7.2.2
2698for non-touch navigation.</p>
2699
2700<h3 id="7_2_1_keyboard">7.2.1. Keyboard</h3>
2701
2702<div class="note">
2703<p>Android Watch and Android Automotive implementations MAY implement a soft
2704keyboard. All other device implementations MUST implement a soft keyboard and:</p>
2705</div>
2706
2707
2708<p>Device implementations:</p>
2709
2710<ul>
2711 <li>MUST include support for the Input Management Framework (which allows
2712third-party developers to create Input Method Editors&mdash;i.e. soft keyboard) as
2713detailed at <a href="http://developer.android.com">http://developer.android.com</a>.</li>
2714 <li>MUST provide at least one soft keyboard implementation (regardless of whether a
2715hard keyboard is present) except for Android Watch devices where the screen
2716size makes it less reasonable to have a soft keyboard.</li>
2717 <li>MAY include additional soft keyboard implementations.</li>
2718 <li>MAY include a hardware keyboard.</li>
2719 <li>MUST NOT include a hardware keyboard that does not match one of the formats
2720specified 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>
2721</ul>
2722
2723<h3 id="7_2_2_non-touch_navigation">7.2.2. Non-touch Navigation</h3>
2724
2725<div class="note">
2726<p>Android Television devices MUST support D-pad.</p>
2727</div>
2728
2729<p>Device implementations:</p>
2730
2731<ul>
2732 <li>MAY omit a non-touch navigation option (trackball, d-pad, or wheel) if the
2733device implementation is not an Android Television device.</li>
2734 <li>MUST report the correct value for android.content.res.Configuration.navigation
2735[<a href="http://developer.android.com/reference/android/content/res/Configuration.html">Resources, 68</a>].</li>
2736 <li>MUST provide a reasonable alternative user interface mechanism for the
2737selection and editing of text, compatible with Input Management Engines. The
2738upstream Android open source implementation includes a selection mechanism
2739suitable for use with devices that lack non-touch navigation inputs.</li>
2740</ul>
2741
2742<h3 id="7_2_3_navigation_keys">7.2.3. Navigation Keys</h3>
2743
2744<div class="note">
2745<p>The availability and visibility requirement of the Home, Recents, and Back
2746functions differ between device types as described in this section.</p>
2747</div>
2748
2749<p>The Home, Recents, and Back functions (mapped to the key events KEYCODE_HOME,
2750KEYCODE_APP_SWITCH, KEYCODE_BACK, respectively) are essential to the Android
2751navigation paradigm and therefore:</p>
2752
2753<ul>
2754 <li>Android Handheld device implementations MUST provide the Home, Recents, and
2755Back functions.</li>
2756 <li>Android Television device implementations MUST provide the Home and Back
2757functions.</li>
2758 <li>Android Watch device implementations MUST have the Home function available to
2759the user, and the Back function except for when it is in UI_MODE_TYPE_WATCH.</li>
2760 <li>Android Automotive implementations MUST provide the Home function and MAY
2761provide Back and Recent functions.</li>
2762 <li>All other types of device implementations MUST provide the Home and Back
2763functions.</li>
2764</ul>
2765
2766<p>These functions MAY be implemented via dedicated physical buttons (such as
2767mechanical or capacitive touch buttons), or MAY be implemented using dedicated
2768software keys on a distinct portion of the screen, gestures, touch panel, etc.
2769Android supports both implementations. All of these functions MUST be
2770accessible with a single action (e.g. tap, double-click or gesture) when
2771visible.</p>
2772
2773<p>Recents function, if provided, MUST have a visible button or icon unless hidden
2774together with other navigation functions in full-screen mode. This does not
2775apply to devices upgrading from earlier Android versions that have physical
2776buttons for navigation and no recents key.</p>
2777
2778<p> The Home and Back functions, if provided, MUST each have a visible button or
2779icon unless hidden together with other navigation functions in full-screen mode
2780or when the uiMode UI_MODE_TYPE_MASK is set to UI_MODE_TYPE_WATCH.</p>
2781
2782<p>The Menu function is deprecated in favor of action bar since Android 4.0.
2783Therefore the new device implementations shipping with Android ANDROID_VERSION and later MUST NOT
2784implement a dedicated physical button for the Menu function. Older device
2785implementations SHOULD NOT implement a dedicated physical button for the Menu
2786function, but if the physical Menu button is implemented and the device is
2787running applications with targetSdkVersion > 10, the device implementation:</p>
2788
2789<ul>
2790 <li>MUST display the action overflow button on the action bar when it is visible
2791and the resulting action overflow menu popup is not empty. For a device
2792implementation launched before Android 4.4 but upgrading to Android ANDROID_VERSION, this
2793is RECOMMENDED.</li>
2794 <li>MUST NOT modify the position of the action overflow popup displayed by
2795selecting the overflow button in the action bar.</li>
2796 <li>MAY render the action overflow popup at a modified position on the screen when
2797it is displayed by selecting the physical menu button.</li>
2798</ul>
2799
2800<p>For backwards compatibility, device implementations MUST make the Menu function
2801available to applications when targetSdkVersion is less than 10, either by a physical
2802button, a software key, or gestures. This Menu function should be presented
2803unless hidden together with other navigation functions.</p>
2804
2805<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
2806the Assist action available to the user at all times when running applications.
2807The Assist action SHOULD be implemented as a long-press on the Home button or a
2808swipe-up gesture on the software Home key. This function MAY be implemented via
2809another physical button, software key, or gesture, but MUST be accessible with
2810a single action (e.g. tap, double-click, or gesture) when other navigation keys
2811are visible.</p>
2812
2813<p>Device implementations MAY use a distinct portion of the screen to display the
2814navigation keys, but if so, MUST meet these requirements:</p>
2815
2816<ul>
2817 <li>Device implementation navigation keys MUST use a distinct portion of the
2818screen, not available to applications, and MUST NOT obscure or otherwise
2819interfere with the portion of the screen available to applications.</li>
2820 <li>Device implementations MUST make available a portion of the display to
2821applications that meets the requirements defined in <a href="#7_1_1_screen_configuration">section 7.1.1</a>.</li>
2822 <li>Device implementations MUST display the navigation keys when applications do
2823not specify a system UI mode, or specify SYSTEM_UI_FLAG_VISIBLE.</li>
2824 <li>Device implementations MUST present the navigation keys in an unobtrusive &ldquo;low
2825profile&rdquo; (eg. dimmed) mode when applications specify
2826SYSTEM_UI_FLAG_LOW_PROFILE.</li>
2827 <li>Device implementations MUST hide the navigation keys when applications specify
2828SYSTEM_UI_FLAG_HIDE_NAVIGATION.</li>
2829</ul>
2830
2831<h3 id="7_2_4_touchscreen_input">7.2.4. Touchscreen Input</h3>
2832
2833<div class="note">
2834<p>Android Handhelds and Watch Devices MUST support touchscreen input.</p>
2835</div>
2836
2837
2838<p>Device implementations SHOULD have a pointer input system of some kind (either
2839mouse-like or touch). However, if a device implementation does not support a
2840pointer input system, it MUST NOT report the android.hardware.touchscreen or
2841android.hardware.faketouch feature constant. Device implementations that do
2842include a pointer input system:</p>
2843
2844<ul>
2845 <li>SHOULD support fully independently tracked pointers, if the device input system
2846supports multiple pointers.</li>
2847 <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>
2848</ul>
2849
2850<p>Android includes support for a variety of touchscreens, touch pads, and fake
2851touch input devices. Touchscreen based device implementations are associated
2852with 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
2853screen. Since the user is directly touching the screen, the system does not
2854require any additional affordances to indicate the objects being manipulated.
2855In contrast, a fake touch interface provides a user input system that
2856approximates a subset of touchscreen capabilities. For example, a mouse or
2857remote control that drives an on-screen cursor approximates touch, but requires
2858the user to first point or focus then click. Numerous input devices like the
2859mouse, trackpad, gyro-based air mouse, gyro-pointer, joystick, and multi-touch
2860trackpad can support fake touch interactions. Android includes the feature
2861constant android.hardware.faketouch, which corresponds to a high-fidelity
2862non-touch (pointer-based) input device such as a mouse or trackpad that can
2863adequately emulate touch-based input (including basic gesture support), and
2864indicates that the device supports an emulated subset of touchscreen
2865functionality. Device implementations that declare the fake touch feature MUST
2866meet the fake touch requirements in <a href="#7_2_5_fake_touch_input">section 7.2.5</a>.</p>
2867
2868<p>Device implementations MUST report the correct feature corresponding to the
2869type of input used. Device implementations that include a touchscreen
2870(single-touch or better) MUST report the platform feature constant
2871android.hardware.touchscreen. Device implementations that report the platform
2872feature constant android.hardware.touchscreen MUST also report the platform
2873feature constant android.hardware.faketouch. Device implementations that do not
2874include a touchscreen (and rely on a pointer device only) MUST NOT report any
2875touchscreen feature, and MUST report only android.hardware.faketouch if they
2876meet the fake touch requirements in <a href="#7_2_5_fake_touch_input">section 7.2.5</a>.</p>
2877
2878<h3 id="7_2_5_fake_touch_input">7.2.5. Fake Touch Input</h3>
2879
2880
2881<p>Device implementations that declare support for android.hardware.faketouch:</p>
2882
2883<ul>
2884 <li>MUST report the absolute X and Y screen positions of the pointer location and
2885display a visual pointer on the screen [<a href="http://developer.android.com/reference/android/view/MotionEvent.html">Resources, 71</a>].</li>
2886 <li>MUST report touch event with the action code that specifies the state change
2887that 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>
2888 <li>MUST support pointer down and up on an object on the screen, which allows users
2889to emulate tap on an object on the screen.</li>
2890 <li>MUST support pointer down, pointer up, pointer down then pointer up in the same
2891place on an object on the screen within a time threshold, which allows users to
2892emulate double tap on an object on the screen [<a href="http://developer.android.com/reference/android/view/MotionEvent.html">Resources, 71</a>].</li>
2893 <li>MUST support pointer down on an arbitrary point on the screen, pointer move to
2894any other arbitrary point on the screen, followed by a pointer up, which allows
2895users to emulate a touch drag.</li>
2896 <li>MUST support pointer down then allow users to quickly move the object to a
2897different position on the screen and then pointer up on the screen, which
2898allows users to fling an object on the screen.</li>
2899</ul>
2900
2901<p>Devices that declare support for android.hardware.faketouch.multitouch.distinct
2902MUST meet the requirements for faketouch above, and MUST also support distinct
2903tracking of two or more independent pointer inputs.</p>
2904
2905<h3 id="7_2_6_game_controller_support">7.2.6. Game Controller Support</h3>
2906
2907
2908<p>Android Television device implementations MUST support button mappings for game
2909controllers as listed below. The upstream Android implementation includes
2910implementation for game controllers that satisfies this requirement. </p>
2911
2912<h4 id="7_2_6_1_button_mappings">7.2.6.1. Button Mappings</h4>
2913
2914
2915<p>Android Television device implementations MUST support the following key
2916mappings:</p>
2917<table>
2918 <tr>
2919 <th>Button</th>
2920 <th>HID Usage</strong><sup>2</sup></td>
2921 <th>Android Button</th>
2922 </tr>
2923 <tr>
2924 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BUTTON_A">A</a><sup>1</sup></td>
2925 <td>0x09 0x0001</td>
2926 <td>KEYCODE_BUTTON_A (96)</td>
2927 </tr>
2928 <tr>
2929 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BUTTON_B">B</a><sup>1</sup></td>
2930 <td>0x09 0x0002</td>
2931 <td>KEYCODE_BUTTON_B (97)</td>
2932 </tr>
2933 <tr>
2934 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BUTTON_X">X</a><sup>1</sup></td>
2935 <td>0x09 0x0004</td>
2936 <td>KEYCODE_BUTTON_X (99)</td>
2937 </tr>
2938 <tr>
2939 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BUTTON_Y">Y</a><sup>1</sup></td>
2940 <td>0x09 0x0005</td>
2941 <td>KEYCODE_BUTTON_Y (100)</td>
2942 </tr>
2943 <tr>
2944 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_DPAD_UP">D-pad up</a><sup>1</sup></p>
2945
2946<p><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_DPAD_DOWN">D-pad down</a><sup>1</sup></td>
2947 <td>0x01 0x00393</td>
2948 <td><a href="http://developer.android.com/reference/android/view/MotionEvent.html#AXIS_HAT_Y">AXIS_HAT_Y</a><sup>4</sup></td>
2949 </tr>
2950 <tr>
2951 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_DPAD_LEFT">D-pad left</a>1</p>
2952
2953<p><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_DPAD_RIGHT">D-pad right</a><sup>1</sup></td>
2954 <td>0x01 0x00393</td>
2955 <td><a href="http://developer.android.com/reference/android/view/MotionEvent.html#AXIS_HAT_X">AXIS_HAT_X</a><sup>4</sup></td>
2956 </tr>
2957 <tr>
2958 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BUTTON_L1">Left shoulder button</a><sup>1</sup></td>
2959 <td>0x09 0x0007</td>
2960 <td>KEYCODE_BUTTON_L1 (102)</td>
2961 </tr>
2962 <tr>
2963 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BUTTON_R1">Right shoulder button</a><sup>1</sup></td>
2964 <td>0x09 0x0008</td>
2965 <td>KEYCODE_BUTTON_R1 (103)</td>
2966 </tr>
2967 <tr>
2968 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BUTTON_THUMBL">Left stick click</a><sup>1</sup></td>
2969 <td>0x09 0x000E</td>
2970 <td>KEYCODE_BUTTON_THUMBL (106)</td>
2971 </tr>
2972 <tr>
2973 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BUTTON_THUMBR">Right stick click</a><sup>1</sup></td>
2974 <td>0x09 0x000F</td>
2975 <td>KEYCODE_BUTTON_THUMBR (107)</td>
2976 </tr>
2977 <tr>
2978 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_HOME">Home</a><sup>1</sup></td>
2979 <td>0x0c 0x0223</td>
2980 <td>KEYCODE_HOME (3)</td>
2981 </tr>
2982 <tr>
2983 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BACK">Back</a><sup>1</sup></td>
2984 <td>0x0c 0x0224</td>
2985 <td>KEYCODE_BACK (4)</td>
2986 </tr>
2987</table>
2988
2989
2990<p class="table_footnote">1 [<a href="http://developer.android.com/reference/android/view/KeyEvent.html">Resources, 72</a>]</p>
2991
2992<p class="table_footnote">2 The above HID usages must be declared within a Game pad CA (0x01 0x0005).</p>
2993
2994<p class="table_footnote">3 This usage must have a Logical Minimum of 0, a Logical Maximum of 7, a
2995Physical Minimum of 0, a Physical Maximum of 315, Units in Degrees, and a
2996Report Size of 4. The logical value is defined to be the clockwise rotation
2997away from the vertical axis; for example, a logical value of 0 represents no
2998rotation and the up button being pressed, while a logical value of 1 represents
2999a rotation of 45 degrees and both the up and left keys being pressed.</p>
3000
3001<p class="table_footnote">4 [<a href="http://developer.android.com/reference/android/view/MotionEvent.html">Resources, 71</a>]</p>
3002
3003<table>
3004 <tr>
3005 <th>Analog Controls</strong><sup>1</sup></td>
3006 <th>HID Usage</th>
3007 <th>Android Button</th>
3008 </tr>
3009 <tr>
3010 <td><a href="http://developer.android.com/reference/android/view/MotionEvent.html#AXIS_LTRIGGER">Left Trigger</a></td>
3011 <td>0x02 0x00C5</td>
3012 <td>AXIS_LTRIGGER </td>
3013 </tr>
3014 <tr>
3015 <td><a href="http://developer.android.com/reference/android/view/MotionEvent.html#AXIS_THROTTLE">Right Trigger</a></td>
3016 <td>0x02 0x00C4</td>
3017 <td>AXIS_RTRIGGER </td>
3018 </tr>
3019 <tr>
3020 <td><a href="http://developer.android.com/reference/android/view/MotionEvent.html#AXIS_Y">Left Joystick</a></td>
3021 <td>0x01 0x0030</p>
3022
3023<p>0x01 0x0031</td>
3024 <td>AXIS_X</p>
3025
3026<p>AXIS_Y</td>
3027 </tr>
3028 <tr>
3029 <td><a href="http://developer.android.com/reference/android/view/MotionEvent.html#AXIS_Z">Right Joystick</a></td>
3030 <td>0x01 0x0032</p>
3031
3032<p>0x01 0x0035</td>
3033 <td>AXIS_Z</p>
3034
3035<p>AXIS_RZ</td>
3036 </tr>
3037</table>
3038
3039
3040<p class="table_footnote">1 [<a href="http://developer.android.com/reference/android/view/MotionEvent.html">Resources, 71</a>]</p>
3041
3042<h3 id="7_2_7_remote_control">7.2.7. Remote Control</h3>
3043
3044
3045<p>Android Television device implementations SHOULD provide a remote control to
3046allow users to access the TV interface. The remote control MAY be a physical
3047remote or can be a software-based remote that is accessible from a mobile phone
3048or tablet. The remote control MUST meet the requirements defined below.</p>
3049
3050<ul>
3051 <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>
3052 <li><strong>Navigation</strong>. All Android Television remotes MUST include Back, Home, and Select buttons and
3053support for D-pad events [<a href="http://developer.android.com/reference/android/view/KeyEvent.html">Resources, 72</a>].</li>
3054</ul>
3055
3056<h2 id="7_3_sensors">7.3. Sensors</h2>
3057
3058
3059<p>Android includes APIs for accessing a variety of sensor types. Devices
3060implementations generally MAY omit these sensors, as provided for in the
3061following subsections. If a device includes a particular sensor type that has a
3062corresponding API for third-party developers, the device implementation MUST
3063implement that API as described in the Android SDK documentation and the
3064Android Open Source documentation on sensors [<a href="http://source.android.com/devices/sensors/">Resources, 73</a>]. For example, device implementations:</p>
3065
3066<ul>
3067 <li>MUST accurately report the presence or absence of sensors per the
3068android.content.pm.PackageManager class [<a href="http://developer.android.com/reference/android/content/pm/PackageManager.html">Resources, 53]</a>.</li>
3069 <li>MUST return an accurate list of supported sensors via the
3070SensorManager.getSensorList() and similar methods.</li>
3071 <li>MUST behave reasonably for all other sensor APIs (for example, by returning
3072true or false as appropriate when applications attempt to register listeners,
3073not calling sensor listeners when the corresponding sensors are not present;
3074etc.).</li>
3075 <li>MUST report all sensor measurements using the relevant International System of
3076Units (metric) values for each sensor type as defined in the Android SDK
3077documentation [<a href="http://developer.android.com/reference/android/hardware/SensorEvent.html">Resources, 74</a>].</li>
3078 <li>SHOULD report the event time in nanoseconds as defined in the Android SDK
3079documentation, representing the time the event happened and synchronized with
3080the SystemClock.elapsedRealtimeNano() clock. Existing and new Android devices
3081are <strong>very strongly encouraged</strong> to meet these requirement so they will be able to upgrade to the future
3082platform releases where this might become a REQUIRED component. The
3083synchronization error SHOULD be below 100 milliseconds [<a href="http://developer.android.com/reference/android/hardware/SensorEvent.html#timestamp">Resources, 75</a>].</li>
3084</ul>
3085
3086<p>The list above is not comprehensive; the documented behavior of the Android SDK
3087and the Android Open Source Documentations on Sensors [<a href="http://source.android.com/devices/sensors/">Resources, 73</a>] is to be considered authoritative.</p>
3088
3089<p>Some sensor types are composite, meaning they can be derived from data provided
3090by one or more other sensors. (Examples include the orientation sensor, and the
3091linear acceleration sensor.) Device implementations SHOULD implement these
3092sensor types, when they include the prerequisite physical sensors as described
3093in [<a href="https://source.android.com/devices/sensors/sensor-types.html">Resources, 76</a>].
3094If a device implementation includes a composite sensor it MUST implement the
3095sensor as described in the Android Open Source documentation on composite
3096sensors [<a href="https://source.android.com/devices/sensors/sensor-types.html#composite_sensor_type_summary">Resources, 76</a>].</p>
3097
3098<p>Some Android sensors support a &ldquo;continuous&rdquo; trigger mode, which returns data
3099continuously [<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
3100sensor, device implementations MUST continuously provide periodic data samples
3101that SHOULD have a jitter below 3%, where jitter is defined as the standard
3102deviation of the difference of the reported timestamp values between
3103consecutive events.</p>
3104
3105<p>Note that the device implementations MUST ensure that the sensor event stream
3106MUST NOT prevent the device CPU from entering a suspend state or waking up from
3107a suspend state.</p>
3108
3109<p>Finally, when several sensors are activated, the power consumption SHOULD NOT
3110exceed the sum of the individual sensor&rsquo;s reported power consumption.</p>
3111
3112<h3 id="7_3_1_accelerometer">7.3.1. Accelerometer</h3>
3113
3114
3115<p>Device implementations SHOULD include a 3-axis accelerometer. Android Handheld
3116devices and Android Watch devices are strongly encouraged to include this
3117sensor. If a device implementation does include a 3-axis accelerometer, it:</p>
3118
3119<ul>
3120 <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>
3121 <li>MUST be able to report events up to a frequency of at least 50 Hz for
3122 Android Watch devices as such devices have a stricter power constraint and
3123 100 Hz for all other device types.</li>
3124 <li>SHOULD report events up to at least 200 Hz.</li>
3125 <li>MUST comply with the Android sensor coordinate system as detailed in the
3126Android APIs [<a href="http://developer.android.com/reference/android/hardware/SensorEvent.html">Resources, 74</a>].</li>
3127 <li>MUST be capable of measuring from freefall up to four times the gravity (4g) or
3128more on any axis.</li>
3129 <li>MUST have a resolution of at least 8-bits and SHOULD have a resolution of at
3130least 16-bits.</li>
3131 <li>SHOULD be calibrated while in use if the characteristics changes over the life
3132cycle and compensated, and preserve the compensation parameters between device
3133reboots.</li>
3134 <li>SHOULD be temperature compensated.</li>
3135 <li>MUST have a standard deviation no greater than 0.05 m/s^, where the standard
3136deviation should be calculated on a per axis basis on samples collected over a
3137period of at least 3 seconds at the fastest sampling rate.</li>
3138 <li>SHOULD implement the TYPE_SIGNIFICANT_MOTION, TYPE_TILT_DETECTOR,
3139TYPE_STEP_DETECTOR, TYPE_STEP_COUNTER composite sensors as described in the
3140Android 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
3141sensors are implemented, the sum of their power consumption MUST always be less
3142than 4 mW and SHOULD each be below 2 mW and 0.5 mW for when the device is in a
3143dynamic or static condition.</li>
3144 <li>If a gyroscope sensor is included, MUST implement the TYPE_GRAVITY and
3145TYPE_LINEAR_ACCELERATION composite sensors and SHOULD implement the
3146TYPE_GAME_ROTATION_VECTOR composite sensor. Existing and new Android devices
3147are strongly encouraged to implement the TYPE_GAME_ROTATION_VECTOR sensor.</li>
3148 <li>SHOULD implement a TYPE_ROTATION_VECTOR composite sensor, if a gyroscope sensor
3149and a magnetometer sensor is also included.</li>
3150</ul>
3151
3152<h3 id="7_3_2_magnetometer">7.3.2. Magnetometer</h3>
3153
3154
3155<p>Device implementations SHOULD include a 3-axis magnetometer (compass). If a
3156device does include a 3-axis magnetometer, it:</p>
3157
3158<ul>
3159 <li>MUST implement the TYPE_MAGNETIC_FIELD sensor and SHOULD also implement
3160TYPE_MAGNETIC_FIELD_UNCALIBRATED sensor. Existing and new Android devices are
3161strongly encouraged to implement the TYPE_MAGNETIC_FIELD_UNCALIBRATED sensor.</li>
3162 <li>MUST be able to report events up to a frequency of at least 10 Hz and SHOULD
3163report events up to at least 50 Hz.</li>
3164 <li>MUST comply with the Android sensor coordinate system as detailed in the
3165Android APIs [<a href="http://developer.android.com/reference/android/hardware/SensorEvent.html">Resources, 74</a>].</li>
3166 <li>MUST be capable of measuring between -900 &micro;T and +900 &micro;T on each axis before
3167saturating.</li>
3168 <li>MUST have a hard iron offset value less than 700 &micro;T and SHOULD have a value
3169below 200 &micro;T, by placing the magnetometer far from dynamic (current-induced)
3170and static (magnet-induced) magnetic fields.</li>
3171 <li>MUST have a resolution equal or denser than 0.6 &micro;T and SHOULD have a resolution
3172equal or denser than 0.2 &micro;.</li>
3173 <li>SHOULD be temperature compensated.</li>
3174 <li>MUST support online calibration and compensation of the hard iron bias, and
3175preserve the compensation parameters between device reboots.</li>
3176 <li>MUST have the soft iron compensation applied&mdash;the calibration can be done either
3177while in use or during the production of the device.</li>
3178 <li>SHOULD have a standard deviation, calculated on a per axis basis on samples
3179collected over a period of at least 3 seconds at the fastest sampling rate, no
3180greater than 0.5 &micro;T.</li>
3181 <li>SHOULD implement a TYPE_ROTATION_VECTOR composite sensor, if an accelerometer
3182sensor and a gyroscope sensor is also included.</li>
3183 <li>MAY implement the TYPE_GEOMAGNETIC_ROTATION_VECTOR sensor if an accelerometer
3184sensor is also implemented. However if implemented, it MUST consume less than
318510 mW and SHOULD consume less than 3 mW when the sensor is registered for batch
3186mode at 10 Hz.</li>
3187</ul>
3188
3189<h3 id="7_3_3_gps">7.3.3. GPS</h3>
3190
3191
3192<p>Device implementations SHOULD include a GPS receiver. If a device
3193implementation does include a GPS receiver, it SHOULD include some form of&ldquo;assisted GPS&rdquo; technique to minimize GPS lock-on time.</p>
3194
3195<h3 id="7_3_4_gyroscope">7.3.4. Gyroscope</h3>
3196
3197
3198<p>Device implementations SHOULD include a gyroscope (angular change sensor).
3199Devices SHOULD NOT include a gyroscope sensor unless a 3-axis accelerometer is
3200also included. If a device implementation includes a gyroscope, it:</p>
3201
3202<ul>
3203 <li>MUST implement the TYPE_GYROSCOPE sensor and SHOULD also implement
3204TYPE_GYROSCOPE_UNCALIBRATED sensor. Existing and new Android devices are
3205strongly encouraged to implement the SENSOR_TYPE_GYROSCOPE_UNCALIBRATED sensor.</li>
3206 <li>MUST be capable of measuring orientation changes up to 1,000 degrees per second.</li>
3207 <li>MUST be able to report events up to a frequency of at least 50 Hz for
3208 Android Watch devices as such devices have a stricter power constraint and
3209 100 Hz for all other device types.</li>
3210 <li>SHOULD report events up to at least 200 Hz.</li>
3211 <li>MUST have a resolution of 12-bits or more and SHOULD have a resolution of
321216-bits or more.</li>
3213 <li>MUST be temperature compensated.</li>
3214 <li>MUST be calibrated and compensated while in use, and preserve the compensation
3215parameters between device reboots.</li>
3216 <li>MUST have a variance no greater than 1e-7 rad^2 / s^2 per Hz (variance per Hz,
3217or rad^2 / s). The variance is allowed to vary with the sampling rate, but must
3218be constrained by this value. In other words, if you measure the variance of
3219the gyro at 1 Hz sampling rate it should be no greater than 1e-7 rad^2/s^2.</li>
3220 <li>SHOULD implement a TYPE_ROTATION_VECTOR composite sensor, if an accelerometer
3221sensor and a magnetometer sensor is also included.</li>
3222 <li>If an accelerometer sensor is included, MUST implement the TYPE_GRAVITY and
3223TYPE_LINEAR_ACCELERATION composite sensors and SHOULD implement the
3224TYPE_GAME_ROTATION_VECTOR composite sensor. Existing and new Android devices
3225are strongly encouraged to implement the TYPE_GAME_ROTATION_VECTOR sensor.</li>
3226</ul>
3227
3228<h3 id="7_3_5_barometer">7.3.5. Barometer</h3>
3229
3230
3231<p>Device implementations SHOULD include a barometer (ambient air pressure
3232sensor). If a device implementation includes a barometer, it:</p>
3233
3234<ul>
3235 <li>MUST implement and report TYPE_PRESSURE sensor.</li>
3236 <li>MUST be able to deliver events at 5 Hz or greater.</li>
3237 <li>MUST have adequate precision to enable estimating altitude.</li>
3238 <li>MUST be temperature compensated.</li>
3239</ul>
3240
3241<h3 id="7_3_6_thermometer">7.3.6. Thermometer</h3>
3242
3243
3244<p>Device implementations MAY include an ambient thermometer (temperature sensor).
3245If present, it MUST be defined as SENSOR_TYPE_AMBIENT_TEMPERATURE and it MUST
3246measure the ambient (room) temperature in degrees Celsius.</p>
3247
3248<p>Device implementations MAY but SHOULD NOT include a CPU temperature sensor. If
3249present, it MUST be defined as SENSOR_TYPE_TEMPERATURE, it MUST measure the
3250temperature of the device CPU, and it MUST NOT measure any other temperature.
3251Note the SENSOR_TYPE_TEMPERATURE sensor type was deprecated in Android 4.0.</p>
3252
3253<h3 id="7_3_7_photometer">7.3.7. Photometer</h3>
3254
3255
3256<p>Device implementations MAY include a photometer (ambient light sensor).</p>
3257
3258<h3 id="7_3_8_proximity_sensor">7.3.8. Proximity Sensor</h3>
3259
3260
3261<p>Device implementations MAY include a proximity sensor. Devices that can make a
3262voice call and indicate any value other than PHONE_TYPE_NONE in getPhoneType
3263SHOULD include a proximity sensor. If a device implementation does include a
3264proximity sensor, it:</p>
3265
3266<ul>
3267 <li>MUST measure the proximity of an object in the same direction as the screen.
3268That is, the proximity sensor MUST be oriented to detect objects close to the
3269screen, as the primary intent of this sensor type is to detect a phone in use
3270by the user. If a device implementation includes a proximity sensor with any
3271other orientation, it MUST NOT be accessible through this API.</li>
3272 <li>MUST have 1-bit of accuracy or more.</li>
3273</ul>
3274
3275<h2 id="7_4_data_connectivity">7.4. Data Connectivity</h2>
3276
3277
3278<h3 id="7_4_1_telephony">7.4.1. Telephony</h3>
3279
3280
3281<p>&ldquo;Telephony&rdquo; as used by the Android APIs and this document refers specifically
3282to hardware related to placing voice calls and sending SMS messages via a GSM
3283or CDMA network. While these voice calls may or may not be packet-switched,
3284they are for the purposes of Android considered independent of any data
3285connectivity that may be implemented using the same network. In other words,
3286the Android &ldquo;telephony&rdquo; functionality and APIs refer specifically to voice
3287calls and SMS. For instance, device implementations that cannot place calls or
3288send/receive SMS messages MUST NOT report the android.hardware.telephony
3289feature or any subfeatures, regardless of whether they use a cellular network
3290for data connectivity.</p>
3291
3292<p>Android MAY be used on devices that do not include telephony hardware. That is,
3293Android is compatible with devices that are not phones. However, if a device
3294implementation does include GSM or CDMA telephony, it MUST implement full
3295support for the API for that technology. Device implementations that do not
3296include telephony hardware MUST implement the full APIs as no-ops.</p>
3297
3298<h3 id="7_4_2_ieee_802_11_wi-fi">7.4.2. IEEE 802.11 (Wi-Fi)</h3>
3299
3300<div class="note">
3301<p>Android Television device implementations MUST include Wi-Fi support.</p>
3302</div>
3303
3304
3305<p>Android Television device implementations MUST include support for one or more
3306forms of 802.11 (b/g/a/n, etc.) and other types of Android device
3307implementation SHOULD include support for one or more forms of 802.11. If a
3308device implementation does include support for 802.11 and exposes the
3309functionality to a third-party application, it MUST implement the corresponding
3310Android API and:</p>
3311
3312<ul>
3313 <li>MUST report the hardware feature flag android.hardware.wifi.</li>
3314 <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>
3315 <li>MUST support multicast DNS (mDNS) and MUST NOT filter mDNS packets
3316(224.0.0.251) at any time of operation including when the screen is not in an
3317active state.</li>
3318</ul>
3319
3320<h4 id="7_4_2_1_wi-fi_direct">7.4.2.1. Wi-Fi Direct</h4>
3321
3322
3323<p>Device implementations SHOULD include support for Wi-Fi Direct (Wi-Fi
3324peer-to-peer). If a device implementation does include support for Wi-Fi
3325Direct, it MUST implement the corresponding Android API as described in the SDK
3326documentation [<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>
3327
3328<ul>
3329 <li>MUST report the hardware feature android.hardware.wifi.direct.</li>
3330 <li>MUST support regular Wi-Fi operation.</li>
3331 <li>SHOULD support concurrent Wi-Fi and Wi-Fi Direct operation.</li>
3332</ul>
3333
3334<h4 id="7_4_2_2_wi-fi_tunneled_direct_link_setup">7.4.2.2. Wi-Fi Tunneled Direct Link Setup</h4>
3335
3336<div class="note">
3337<p>Android Television device implementations MUST include support for Wi-Fi
3338Tunneled Direct Link Setup (TDLS).</p>
3339</div>
3340
3341
3342<p>Android Television device implementations MUST include support for Wi-Fi
3343Tunneled Direct Link Setup (TDLS) and other types of Android device
3344implementations SHOULD include support for Wi-Fi TDLS as described in the
3345Android 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
3346by the WiFiManager API, the device:</p>
3347
3348<ul>
3349 <li>SHOULD use TDLS only when it is possible AND beneficial.</li>
3350 <li>SHOULD have some heuristic and NOT use TDLS when its performance might be worse
3351than going through the Wi-Fi access point.</li>
3352</ul>
3353
3354<h3 id="7_4_3_bluetooth">7.4.3. Bluetooth</h3>
3355
3356<div class="note">
3357<p>Android Watch and Automotive implementations MUST support Bluetooth. Android
3358Television implementations MUST support Bluetooth and Bluetooth LE.</p>
3359</div>
3360
3361
3362<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
3363Energy MUST declare the relevant platform features (android.hardware.bluetooth
3364and android.hardware.bluetooth_le respectively) and implement the platform
3365APIs. Device implementations SHOULD implement relevant Bluetooth profiles such
3366as A2DP, AVCP, OBEX, etc. as appropriate for the device. Android Television
3367device implementations MUST support Bluetooth and Bluetooth LE. </p>
3368
3369<p>Device implementations including support for Bluetooth Low Energy:</p>
3370
3371<ul>
3372 <li>MUST declare the hardware feature android.hardware.bluetooth_le.</li>
3373 <li>MUST enable the GATT (generic attribute profile) based Bluetooth APIs as
3374described in the SDK documentation and [<a href="http://developer.android.com/reference/android/bluetooth/package-summary.html">Resources, 82</a>].</li>
3375 <li>SHOULD support offloading of the filtering logic to the bluetooth chipset when
3376implementing 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
3377android.bluetooth.BluetoothAdapter.isOffloadedFilteringSupported() method.</li>
3378 <li>SHOULD support offloading of the batched scanning to the bluetooth chipset, but
3379if not supported, MUST report &lsquo;false&rsquo; whenever queried via the
3380android.bluetooth.BluetoothAdapater.isOffloadedScanBatchingSupported() method.</li>
3381 <li>SHOULD support multi advertisement with at least 4 slots, but if not supported,
3382MUST report &lsquo;false&rsquo; whenever queried via the
3383android.bluetooth.BluetoothAdapter.isMultipleAdvertisementSupported() method.</li>
3384</ul>
3385
3386<h3 id="7_4_4_near-field_communications">7.4.4. Near-Field Communications</h3>
3387
3388
3389<p>Device implementations SHOULD include a transceiver and related hardware for
3390Near-Field Communications (NFC). If a device implementation does include NFC
3391hardware and plans to make it available to third-party apps, then it:</p>
3392
3393<ul>
3394 <li>MUST report the android.hardware.nfc feature from the
3395android.content.pm.PackageManager.hasSystemFeature() method [<a href="http://developer.android.com/reference/android/content/pm/PackageManager.html">Resources, 53</a>].</li>
3396 <li>MUST be capable of reading and writing NDEF messages via the following NFC
3397standards:
3398 <ul>
3399 <li>MUST be capable of acting as an NFC Forum reader/writer (as defined by the NFC
3400Forum technical specification NFCForum-TS-DigitalProtocol-1.0) via the
3401following NFC standards:
3402 <ul>
3403 <li>NfcA (ISO14443-3A)</li>
3404 <li>NfcB (ISO14443-3B)</li>
3405 <li>NfcF (JIS 6319-4)</li>
3406 <li>IsoDep (ISO 14443-4)</li>
3407 <li>NFC Forum Tag Types 1, 2, 3, 4 (defined by the NFC Forum)</li>
3408 </ul>
3409 <li>SHOULD be capable of reading and writing NDEF messages via the following NFC
3410standards. Note that while the NFC standards below are stated as SHOULD, the
3411Compatibility Definition for a future version is planned to change these to
3412MUST. These standards are optional in this version but will be required in
3413future 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>
3414 <ul>
3415 <li>NfcV (ISO 15693)</li>
3416 </ul></li>
3417 <li>MUST be capable of transmitting and receiving data via the following
3418peer-to-peer standards and protocols:
3419 <ul>
3420 <li>ISO 18092</li>
3421 <li>LLCP 1.0 (defined by the NFC Forum)</li>
3422 <li>SDP 1.0 (defined by the NFC Forum)</li>
3423 <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>
3424 <li>SNEP 1.0 (defined by the NFC Forum)</li>
3425 </ul></li>
3426 <li>MUST include support for Android Beam [<a href="http://developer.android.com/guide/topics/connectivity/nfc/nfc.html">Resources, 85</a>]:
3427 <ul>
3428 <li>MUST implement the SNEP default server. Valid NDEF messages received by the
3429default SNEP server MUST be dispatched to applications using the
3430android.nfc.ACTION_NDEF_DISCOVERED intent. Disabling Android Beam in settings
3431MUST NOT disable dispatch of incoming NDEF message.</li>
3432 <li>MUST honor the android.settings.NFCSHARING_SETTINGS intent to show NFC sharing
3433settings [<a href="http://developer.android.com/reference/android/provider/Settings.html#ACTION_NFCSHARING_SETTINGS">Resources, 86</a>].</li>
3434 <li>MUST implement the NPP server. Messages received by the NPP server MUST be
3435processed the same way as the SNEP default server.</li>
3436 <li>MUST implement a SNEP client and attempt to send outbound P2P NDEF to the
3437default SNEP server when Android Beam is enabled. If no default SNEP server is
3438found then the client MUST attempt to send to an NPP server.</li>
3439 <li>MUST allow foreground activities to set the outbound P2P NDEF message using
3440android.nfc.NfcAdapter.setNdefPushMessage, and
3441android.nfc.NfcAdapter.setNdefPushMessageCallback, and
3442android.nfc.NfcAdapter.enableForegroundNdefPush.</li>
3443 <li>SHOULD use a gesture or on-screen confirmation, such as 'Touch to Beam', before
3444sending outbound P2P NDEF messages.</li>
3445 <li>SHOULD enable Android Beam by default and MUST be able to send and receive
3446using Android Beam, even when another proprietary NFC P2p mode is turned on.</li>
3447 <li>MUST support NFC Connection handover to Bluetooth when the device supports
3448Bluetooth Object Push Profile. Device implementations MUST support connection
3449handover to Bluetooth when using android.nfc.NfcAdapter.setBeamPushUris, by
3450implementing the &ldquo;Connection Handover version 1.2&rdquo; [<a href="http://members.nfc-forum.org/specs/spec_list/#conn_handover">Resources, 87</a>] and &ldquo;Bluetooth Secure Simple Pairing Using NFC version 1.0&rdquo; [<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
3451LLCP service with service name &ldquo;urn:nfc:sn:handover&rdquo; for exchanging the
3452handover request/select records over NFC, and it MUST use the Bluetooth Object
3453Push Profile for the actual Bluetooth data transfer. For legacy reasons (to
3454remain compatible with Android 4.1 devices), the implementation SHOULD still
3455accept SNEP GET requests for exchanging the handover request/select records
3456over NFC. However an implementation itself SHOULD NOT send SNEP GET requests
3457for performing connection handover.</li>
3458 </ul></li>
3459 <li>MUST poll for all supported technologies while in NFC discovery mode.</li>
3460 <li>SHOULD be in NFC discovery mode while the device is awake with the screen
3461active and the lock-screen unlocked.</li>
3462</ul>
3463</ul>
3464
3465<p>(Note that publicly available links are not available for the JIS, ISO, and NFC
3466Forum specifications cited above.)</p>
3467
3468<p>Android includes support for NFC Host Card Emulation (HCE) mode. If a
3469device implementation does include an NFC controller chipset capable of HCE and
3470Application ID (AID) routing, then it:</p>
3471
3472<ul>
3473 <li>MUST report the android.hardware.nfc.hce feature constant.</li>
3474 <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>
3475</ul>
3476
3477<p>Additionally, device implementations MAY include reader/writer support for the
3478following MIFARE technologies.</p>
3479
3480<ul>
3481 <li>MIFARE Classic</li>
3482 <li>MIFARE Ultralight</li>
3483 <li>NDEF on MIFARE Classic</li>
3484</ul>
3485
3486<p>Note that Android includes APIs for these MIFARE types. If a device
3487implementation supports MIFARE in the reader/writer role, it:</p>
3488
3489<ul>
3490 <li>MUST implement the corresponding Android APIs as documented by the Android SDK.</li>
3491 <li>MUST report the feature com.nxp.mifare from the
3492android.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
3493as a constant on the PackageManager class.</li>
3494 <li>MUST NOT implement the corresponding Android APIs nor report the com.nxp.mifare
3495feature unless it also implements general NFC support as described in this
3496section.</li>
3497</ul>
3498
3499<p>If a device implementation does not include NFC hardware, it MUST NOT declare
3500the android.hardware.nfc feature from the
3501android.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>
3502
3503<p>As the classes android.nfc.NdefMessage and android.nfc.NdefRecord represent a
3504protocol-independent data representation format, device implementations MUST
3505implement these APIs even if they do not include support for NFC or declare the
3506android.hardware.nfc feature.</p>
3507
3508<h3 id="7_4_5_minimum_network_capability">7.4.5. Minimum Network Capability</h3>
3509
3510
3511<p>Device implementations MUST include support for one or more forms of data
3512networking. Specifically, device implementations MUST include support for at
3513least one data standard capable of 200Kbit/sec or greater. Examples of
3514technologies that satisfy this requirement include EDGE, HSPA, EV-DO, 802.11g,
3515Ethernet, Bluetooth PAN, etc.</p>
3516
3517<p>Device implementations where a physical networking standard (such as Ethernet)
3518is the primary data connection SHOULD also include support for at least one
3519common wireless data standard, such as 802.11 (Wi-Fi).</p>
3520
3521<p>Devices MAY implement more than one form of data connectivity.</p>
3522
3523<h3 id="7_4_6_sync_settings">7.4.6. Sync Settings</h3>
3524
3525
3526<p>Device implementations MUST have the master auto-sync setting on by default so
3527that the method getMasterSyncAutomatically() returns &ldquo;true&rdquo; [<a href="http://developer.android.com/reference/android/content/ContentResolver.html">Resources, 89</a>].</p>
3528
3529<h2 id="7_5_cameras">7.5. Cameras</h2>
3530
3531
3532<p>Device implementations SHOULD include a rear-facing camera and MAY include a
3533front-facing camera. A rear-facing camera is a camera located on the side of
3534the device opposite the display; that is, it images scenes on the far side of
3535the device, like a traditional camera. A front-facing camera is a camera
3536located on the same side of the device as the display; that is, a camera
3537typically used to image the user, such as for video conferencing and similar
3538applications.</p>
3539
3540<p>If a device implementation includes at least one camera, it SHOULD be possible
3541for an application to simultaneously allocate 3 bitmaps equal to the size of
3542the images produced by the largest-resolution camera sensor on the device.</p>
3543
3544<h3 id="7_5_1_rear-facing_camera">7.5.1. Rear-Facing Camera</h3>
3545
3546
3547<p>Device implementations SHOULD include a rear-facing camera. If a device
3548implementation includes at least one rear-facing camera, it:</p>
3549
3550<ul>
3551 <li>MUST report the feature flag android.hardware.camera and
3552android.hardware.camera.any.</li>
3553 <li>MUST have a resolution of at least 2 megapixels.</li>
3554 <li>SHOULD have either hardware auto-focus or software auto-focus implemented in
3555the camera driver (transparent to application software).</li>
3556 <li>MAY have fixed-focus or EDOF (extended depth of field) hardware.</li>
3557 <li>MAY include a flash. If the Camera includes a flash, the flash lamp MUST NOT be
3558lit while an android.hardware.Camera.PreviewCallback instance has been
3559registered on a Camera preview surface, unless the application has explicitly
3560enabled the flash by enabling the FLASH_MODE_AUTO or FLASH_MODE_ON attributes
3561of a Camera.Parameters object. Note that this constraint does not apply to the
3562device&rsquo;s built-in system camera application, but only to third-party
3563applications using Camera.PreviewCallback.</li>
3564</ul>
3565
3566<h3 id="7_5_2_front-facing_camera">7.5.2. Front-Facing Camera</h3>
3567
3568
3569<p>Device implementations MAY include a front-facing camera. If a device
3570implementation includes at least one front-facing camera, it:</p>
3571
3572<ul>
3573 <li>MUST report the feature flag android.hardware.camera.any and
3574android.hardware.camera.front.</li>
3575 <li>MUST have a resolution of at least VGA (640x480 pixels).</li>
3576 <li>MUST NOT use a front-facing camera as the default for the Camera API. The
3577camera API in Android has specific support for front-facing cameras and device
3578implementations MUST NOT configure the API to to treat a front-facing camera as
3579the default rear-facing camera, even if it is the only camera on the device.</li>
3580 <li>MAY include features (such as auto-focus, flash, etc.) available to rear-facing
3581cameras as described in <a href="#7_5_1_rear-facing_camera">section 7.5.1</a>.</li>
3582 <li>MUST horizontally reflect (i.e. mirror) the stream displayed by an app in a
3583CameraPreview, as follows:
3584 <ul>
3585 <li>If the device implementation is capable of being rotated by user (such as
3586automatically via an accelerometer or manually via user input), the camera
3587preview MUST be mirrored horizontally relative to the device&rsquo;s current
3588orientation.</li>
3589 <li>If the current application has explicitly requested that the Camera display be
3590rotated 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
3591orientation specified by the application.</li>
3592 <li>Otherwise, the preview MUST be mirrored along the device&rsquo;s default horizontal
3593axis.</li>
3594 </ul></li>
3595 <li>MUST mirror the image displayed by the postview in the same manner as the
3596camera preview image stream. If the device implementation does not support
3597postview, this requirement obviously does not apply.</li>
3598 <li>MUST NOT mirror the final captured still image or video streams returned to
3599application callbacks or committed to media storage.</li>
3600</ul>
3601
3602<h3 id="7_5_3_external_camera">7.5.3. External Camera</h3>
3603
3604
3605<p>Device implementations with USB host mode MAY include support for an external
3606camera that connects to the USB port. If a device includes support for an
3607external camera, it:</p>
3608
3609<ul>
3610 <li>MUST declare the platform feature android.hardware.camera.external and
3611android.hardware camera.any.</li>
3612 <li>MUST support USB Video Class (UVC 1.0 or higher).</li>
3613 <li>MAY support multiple cameras.</li>
3614</ul>
3615
3616<p>Video compression (such as MJPEG) support is RECOMMENDED to enable transfer of
3617high-quality unencoded streams (i.e. raw or independently compressed picture
3618streams). Camera-based video encoding MAY be supported. If so, a simultaneous
3619unencoded/ MJPEG stream (QVGA or greater resolution) MUST be accessible to the
3620device implementation.</p>
3621
3622<h3 id="7_5_4_camera_api_behavior">7.5.4. Camera API Behavior</h3>
3623
3624
3625<p>Android includes two API packages to access the camera, the newer
3626android.hardware.camera2 API expose lower-level camera control to the app,
3627including efficient zero-copy burst/streaming flows and per-frame controls of
3628exposure, gain, white balance gains, color conversion, denoising, sharpening,
3629and more.</p>
3630
3631<p>The older API package, android.hardware.Camera, is marked as deprecated in
3632Android 5.0 but as it should still be available for apps to use Android device
3633implementations MUST ensure the continued support of the API as described in
3634this section and in the Android SDK.</p>
3635
3636<p>Device implementations MUST implement the following behaviors for the
3637camera-related APIs, for all available cameras:</p>
3638
3639<ul>
3640 <li>If an application has never called
3641android.hardware.Camera.Parameters.setPreviewFormat(int), then the device MUST
3642use android.hardware.PixelFormat.YCbCr_420_SP for preview data provided to
3643application callbacks.</li>
3644 <li>If an application registers an android.hardware.Camera.PreviewCallback instance
3645and the system calls the onPreviewFrame() method when the preview format is
3646YCbCr_420_SP, the data in the byte[] passed into onPreviewFrame() must further
3647be in the NV21 encoding format. That is, NV21 MUST be the default.</li>
3648 <li>For android.hardware.Camera, device implementations MUST support the YV12
3649format (as denoted by the android.graphics.ImageFormat.YV12 constant) for
3650camera previews for both front- and rear-facing cameras. (The hardware video
3651encoder and camera may use any native pixel format, but the device
3652implementation MUST support conversion to YV12.)</li>
3653 <li>For android.hardware.camera2, device implementations must support the
3654android.hardware.ImageFormat.YUV_420_888 and android.hardware.ImageFormat.JPEG
3655formats as outputs through the android.media.ImageReader API.</li>
3656</ul>
3657
3658<p>Device implementations MUST still implement the full Camera API included in the
3659Android 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
3660capabilities. For instance, cameras that lack autofocus MUST still call any
3661registered android.hardware.Camera.AutoFocusCallback instances (even though
3662this has no relevance to a non-autofocus camera.) Note that this does apply to
3663front-facing cameras; for instance, even though most front-facing cameras do
3664not support autofocus, the API callbacks must still be &ldquo;faked&rdquo; as described.</p>
3665
3666<p>Device implementations MUST recognize and honor each parameter name defined as
3667a constant on the android.hardware.Camera.Parameters class, if the underlying
3668hardware supports the feature. If the device hardware does not support a
3669feature, the API must behave as documented. Conversely, device implementations
3670MUST NOT honor or recognize string constants passed to the
3671android.hardware.Camera.setParameters() method other than those documented as
3672constants on the android.hardware.Camera.Parameters. That is, device
3673implementations MUST support all standard Camera parameters if the hardware
3674allows, and MUST NOT support custom Camera parameter types. For instance,
3675device implementations that support image capture using high dynamic range
3676(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>
3677
3678<p>Because not all device implementations can fully support all the features of
3679the android.hardware.camera2 API, device implementations MUST report the proper
3680level of support with the android.info.supportedHardwareLevel property as
3681described 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>
3682
3683<p>Device implementations MUST also declare its Individual camera capabilities of
3684android.hardware.camera2 via the android.request.availableCapabilities property
3685and 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>
3686
3687<p>Device implementations MUST broadcast the Camera.ACTION_NEW_PICTURE intent
3688whenever a new picture is taken by the camera and the entry of the picture has
3689been added to the media store.</p>
3690
3691<p>Device implementations MUST broadcast the Camera.ACTION_NEW_VIDEO intent
3692whenever a new video is recorded by the camera and the entry of the picture has
3693been added to the media store.</p>
3694
3695<h3 id="7_5_5_camera_orientation">7.5.5. Camera Orientation</h3>
3696
3697
3698<p>Both front- and rear-facing cameras, if present, MUST be oriented so that the
3699long dimension of the camera aligns with the screen&rsquo;s long dimension. That is,
3700when the device is held in the landscape orientation, cameras MUST capture
3701images in the landscape orientation. This applies regardless of the device&rsquo;s
3702natural orientation; that is, it applies to landscape-primary devices as well
3703as portrait-primary devices.</p>
3704
3705<h2 id="7_6_memory_and_storage">7.6. Memory and Storage</h2>
3706
3707
3708<h3 id="7_6_1_minimum_memory_and_storage">7.6.1. Minimum Memory and Storage</h3>
3709
3710<div class="note">
3711<p>Android Television devices MUST have at least 5GB of non-volatile storage
3712available for application private data.</p>
3713</div>
3714
3715
3716<p>The memory available to the kernel and userspace on device implementations MUST
3717be at least equal or larger than the minimum values specified by the following
3718table. (See <a href="#7_1_1_screen_configuration">section 7.1.1</a> for screen size and density definitions.)</p>
3719<table>
3720 <tr>
3721 <th>Density and screen size</th>
3722 <th>32-bit device</th>
3723 <th>64-bit device</th>
3724 </tr>
3725 <tr>
3726 <td>Android Watch devices (due to smaller screens)</td>
3727 <td>416MB</td>
3728 <td>Not applicable</td>
3729 </tr>
3730 <tr>
3731 <td><ul>
3732 <li class="table_list">hdpi or lower on small/normal screens</li>
3733 <li class="table_list">mdpi or lower on large screens</li>
3734 <li class="table_list">ldpi or lower on extra large screens</li>
3735 </ul></td>
3736 <td>424MB</td>
3737 <td>Not applicable</td>
3738 </tr>
3739 <tr>
3740 <td><ul>
3741 <li class="table_list">xhdpi or higher on small/normal screens</li>
3742 <li class="table_list">hdpi or higher on large screens</li>
3743 <li class="table_list">mdpi or higher on extra large screens</li></ul></td>
3744 <td>512MB</td>
3745 <td>832MB</td>
3746 </tr>
3747 <tr>
3748 <td><ul>
3749 <li class="table_list">400dpi or higher on small/normal screens</li>
3750 <li class="table_list">xhdpi or higher on large screens</li>
3751 <li class="table_list">tvdpi or higher on extra large screens</li></ul></td>
3752 <td>896MB</td>
3753 <td>1280MB</td>
3754 </tr>
3755 <tr>
3756 <td><ul>
3757 <li class="table_list">560dpi or higher on small/normal screens</li>
3758 <li class="table_list">400dpi or higher on large screens</li>
3759 <li class="table_list">xhdpi or higher on extra large screens</li></ul></td>
3760 <td>1344MB</td>
3761 <td>1824MB</td>
3762 </tr>
3763</table>
3764
3765
3766<p>The minimum memory values MUST be in addition to any memory space already
3767dedicated to hardware components such as radio, video, and so on that is not
3768under the kernel&rsquo;s control.</p>
3769
3770<p>Device implementations with less than 512MB of memory available to the kernel
3771and userspace, unless an Android Watch, MUST return the value "true" for
3772ActivityManager.isLowRamDevice().</p>
3773
3774<p>Android Television devices MUST have at least 5GB and other device
3775implementations MUST have at least 1.5GB of non-volatile storage available for
3776application private data. That is, the /data partition MUST be at least 5GB for
3777Android Television devices and at least 1.5GB for other device implementations.
3778Device implementations that run Android are <strong>very strongly encouraged</strong> to have at least 3GB of non-volatile storage for application private data so
3779they will be able to upgrade to the future platform releases.</p>
3780
3781<p>The Android APIs include a Download Manager that applications MAY use to
3782download 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
3783downloading individual files of at least 100MB in size to the default &ldquo;cache"
3784location.</p>
3785
3786<h3 id="7_6_2_application_shared_storage">7.6.2. Application Shared Storage</h3>
3787
3788
3789<p>Device implementations MUST offer shared storage for applications also often
3790referred as &ldquo;shared external storage&rdquo;. </p>
3791
3792<p>Device implementations MUST be configured with shared storage mounted by
3793default, &ldquo;out of the box&rdquo;. If the shared storage is not mounted on the Linux
3794path /sdcard, then the device MUST include a Linux symbolic link from /sdcard
3795to the actual mount point.</p>
3796
3797<p>Device implementations MAY have hardware for user-accessible removable storage,
3798such as a Secure Digital (SD) card slot. If this slot is used to satisfy the
3799shared storage requirement, the device implementation:</p>
3800
3801<ul>
3802 <li>MUST implement a toast or pop-up user interface warning the user when there is
3803no SD card.</li>
3804 <li>MUST include a FAT-formatted SD card 1GB in size or larger OR show on the box
3805and other material available at time of purchase that the SD card has to be
3806separately purchased.</li>
3807 <li>MUST mount the SD card by default.</li>
3808</ul>
3809
3810<p>Alternatively, device implementations MAY allocate internal (non-removable)
3811storage as shared storage for apps as included in the upstream Android Open
3812Source Project; device implementations SHOULD use this configuration and
3813software implementation. If a device implementation uses internal
3814(non-removable) storage to satisfy the shared storage requirement, that storage
3815MUST be 1GB in size or larger and mounted on /sdcard (or /sdcard MUST be a
3816symbolic link to the physical location if it is mounted elsewhere).</p>
3817
3818<p>Device implementations MUST enforce as documented the
3819android.permission.WRITE_EXTERNAL_STORAGE permission on this shared storage.
3820Shared storage MUST otherwise be writable by any application that obtains that
3821permission.</p>
3822
3823<p>Device implementations that include multiple shared storage paths (such as both
3824an SD card slot and shared internal storage) MUST NOT allow Android
3825applications to write to the secondary external storage, except for their
3826package-specific directories on the secondary external storage, but SHOULD
3827expose content from both storage paths transparently through Android&rsquo;s media
3828scanner service and android.provider.MediaStore.</p>
3829
3830<p>Regardless of the form of shared storage used, if the device implementation
3831has a USB port with USB peripheral mode support, it MUST provide some mechanism
3832to access the contents of shared storage from a host computer. Device
3833implementations MAY use USB mass storage, but SHOULD use Media Transfer Protocol
3834to satisfy this requirement. If the device implementation supports Media
3835Transfer Protocol, it:</p>
3836
3837<ul>
3838 <li>SHOULD be compatible with the reference Android MTP host, Android File Transfer
3839[<a href="http://www.android.com/filetransfer">Resources, 96</a>].</li>
3840 <li>SHOULD report a USB device class of 0x00.</li>
3841 <li>SHOULD report a USB interface name of 'MTP'.</li>
3842</ul>
3843
3844<h2 id="7_7_usb">7.7. USB</h2>
3845
3846
3847<p>Device implementations SHOULD support USB peripheral mode and SHOULD support
3848USB host mode.</p>
3849
3850<p>If a device implementation includes a USB port supporting peripheral mode:</p>
3851
3852<ul>
3853 <li>The port MUST be connectable to a USB host that has a standard type-A or type
3854-C USB port.</li>
3855 <li>The port SHOULD use micro-A, micro-AB or type-C USB form factor. Existing and
3856new 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>
3857 <li>The port SHOULD be centered in the middle of an edge. Device implementations
3858SHOULD either locate the port on the bottom of the device (according to natural
3859orientation) or enable software screen rotation for all apps (including home
3860screen), so that the display draws correctly when the device is oriented with
3861the 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>
3862 <li>It MUST allow a USB host connected with the Android device to access the
3863contents of the shared storage volume using either USB mass storage or Media
3864Transfer Protocol.</li>
3865 <li>It SHOULD implement the Android Open Accessory (AOA) API and specification as
3866documented in the Android SDK documentation, and if it is an Android Handheld
3867device it MUST implement the AOA API. Device implementations implementing the
3868AOA specification:
3869 <ul>
3870 <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>
3871 <li>MUST implement the USB audio class as documented in the Android SDK
3872documentation [<a href="http://developer.android.com/reference/android/hardware/usb/UsbConstants.html#USB_CLASS_AUDIO">Resources, 98</a>].</li>
3873 </ul></li>
3874 <li>It SHOULD implement support to draw 1.5 A current during HS chirp and traffic
3875as 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>
3876 <li>The value of iSerialNumber in USB standard device descriptor MUST be equal to
3877the value of android.os.Build.SERIAL.</li>
3878</ul>
3879
3880<p>If a device implementation includes a USB port supporting host mode, it:</p>
3881
3882<ul>
3883 <li>SHOULD use a type-C USB port, if the device implementation supports USB 3.1.</li>
3884 <li>MAY use a non-standard port form factor, but if so MUST ship with a cable or
3885cables adapting the port to a standard type-A or type-C USB port.</li>
3886 <li>MAY use a micro-AB USB port, but if so SHOULD ship with a cable or cables
3887adapting the port to a standard type-A or type-C USB port.</li>
3888 <li>is <strong>very strongly RECOMMENDED</strong> to implement the USB audio class as documented in the Android SDK
3889documentation [<a href="http://developer.android.com/reference/android/hardware/usb/UsbConstants.html#USB_CLASS_AUDIO">Resources, 98</a>].</li>
3890 <li>MUST implement the Android USB host API as documented in the Android SDK, and
3891MUST 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>
3892 <li>SHOULD support the Charging Downstream Port output current range of 1.5 A ~ 5 A
3893as 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>
3894</ul>
3895
3896<h2 id="7_8_audio">7.8. Audio</h2>
3897
3898
3899<h3 id="7_8_1_microphone">7.8.1. Microphone</h3>
3900
3901<div class="note">
3902<p>Android Handheld, Watch, and Automotive implementations MUST include a
3903microphone.</p>
3904</div>
3905
3906
3907<p>Device implementations MAY omit a microphone. However, if a device
3908implementation omits a microphone, it MUST NOT report the
3909android.hardware.microphone feature constant, and MUST implement the audio
3910recording API at least as no-ops, per <a href="#7_hardware_compatibility">section 7</a>. Conversely, device implementations that do possess a microphone:</p>
3911
3912<ul>
3913 <li>MUST report the android.hardware.microphone feature constant
3914 <li>MUST meet the audio recording requirements in <a href="#5_4_audio_recording">section 5.4</a>
3915 <li>MUST meet the audio latency requirements in <a href="#5_6_audio_latency">section 5.6</a>
3916</ul>
3917
3918<h3 id="7_8_2_audio_output">7.8.2. Audio Output</h3>
3919
3920<div class="note">
3921<p>Android Watch devices MAY include an audio output.</p>
3922</div>
3923
3924<p>Device implementations including a speaker or with an audio/multimedia output
3925port for an audio output peripheral as a headset or an external speaker:</p>
3926
3927<ul>
3928 <li>MUST report the android.hardware.audio.output feature constant.</li>
3929 <li>MUST meet the audio playback requirements in <a href="#5_5_audio_playback">section 5.5</a>.</li>
3930 <li>MUST meet the audio latency requirements in <a href="#5_6_audio_latency">section 5.6</a>.</li>
3931</ul>
3932
3933<p>Conversely, if a device implementation does not include a speaker or audio
3934output port, it MUST NOT report the android.hardware.audio output feature, and
3935MUST implement the Audio Output related APIs as no-ops at least. </p>
3936
3937<p>Android Watch device implementation MAY but SHOULD NOT have audio output, but
3938other types of Android device implementations MUST have an audio output and
3939declare android.hardware.audio.output.</p>
3940
3941<h4 id="7_8_2_1_analog_audio_ports">7.8.2.1. Analog Audio Ports</h4>
3942
3943
3944<p>In order to be compatible with the headsets and other audio accessories using
3945the 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
3946one of the audio port(s) SHOULD be a 4 conductor 3.5mm audio jack. If a device
3947implementation has a 4 conductor 3.5mm audio jack, it:</p>
3948
3949<ul>
3950 <li>MUST support audio playback to stereo headphones and stereo headsets with a
3951microphone, and SHOULD support audio recording from stereo headsets with a
3952microphone.</li>
3953 <li>MUST support TRRS audio plugs with the CTIA pin-out order, and SHOULD support
3954audio plugs with the OMTP pin-out order.</li>
3955 <li>MUST support the detection of microphone on the plugged in audio accessory, if
3956the device implementation supports a microphone, and broadcast the
3957android.intent.action.HEADSET_PLUG with the extra value microphone set as 1.</li>
3958 <li>SHOULD support the detection and mapping to the keycodes for the following 3
3959ranges of equivalent impedance between the microphone and ground conductors on
3960the audio plug:
3961 <ul>
3962 <li><strong>70 ohm or less</strong>: KEYCODE_HEADSETHOOK</li>
3963 <li><strong>210&#45;290 Ohm</strong>:<strong> </strong>KEYCODE_VOLUME_UP</li>
3964 <li><strong>360&#45;680 Ohm</strong>: KEYCODE_VOLUME_DOWN</li>
3965 </ul></li>
3966 <li>SHOULD support the detection and mapping to the keycode for the following range
3967of equivalent impedance between the microphone and ground conductors on the
3968audio plug:
3969 <ul>
3970 <li><strong>110&#45;180 Ohm: </strong>KEYCODE_VOICE_ASSIST</li>
3971 </ul></li>
3972 <li>MUST trigger ACTION_HEADSET_PLUG upon a plug insert, but only after all
3973contacts on plug are touching their relevant segments on the jack.</li>
3974 <li>MUST be capable of driving at least 150mV +/- 10% of output voltage on a 32 Ohm
3975speaker impedance.</li>
3976 <li>MUST have a microphone bias voltage between 1.8V ~ 2.9V.</li>
3977</ul>
3978
3979<h1 id="8_performance_compatibility">8. Performance Compatibility</h1>
3980
3981
3982<p>Some minimum performance criterias are critical to the user experience and
3983impacts the baseline assumptions developers would have when developing an app.
3984Android Watch devices SHOULD and other type of device implementations MUST meet
3985the following criteria:</p>
3986
3987<h2 id="8_1_user_experience_consistency">8.1. User Experience Consistency</h2>
3988
3989
3990<p>Device implementations MUST provide a smooth user interface by ensuring a
3991consistent frame rate and response times for applications and games. Device
3992implementations MUST meet the following requirements: </p>
3993
3994<ul>
3995 <li><strong>Consistent frame latency</strong>. Inconsistent frame latency or a delay to render frames MUST NOT happen more
3996often than 5 frames in a second, and SHOULD be below 1 frames in a second.</li>
3997 <li><strong>User interface latency</strong>. Device implementations MUST ensure low latency user experience by scrolling a
3998list of 10K list entries as defined by the Android Compatibility Test Suite
3999(CTS) in less than 36 secs.</li>
4000 <li><strong>Task switching</strong>. When multiple applications have been launched, re-launching an already-running
4001application after it has been launched MUST take less than 1 second.</li>
4002</ul>
4003
4004<h2 id="8_2_file_i_o_access_performance">8.2. File I/O Access Performance</h2>
4005
4006
4007<p>Device implementations MUST ensure internal storage file access performance consistency for read
4008and write operations. </p>
4009
4010<ul>
4011 <li><strong>Sequential write</strong>. Device implementations MUST ensure a sequential write performance of at least 5MB/s
4012for a 256MB file using 10MB write buffer.</li>
4013 <li><strong>Random write</strong>. Device implementations MUST ensure a random write performance of at least 0.5MB/s for a
4014256MB file using 4KB write buffer.</li>
4015 <li><strong>Sequential read</strong>. Device implementations MUST ensure a sequential read performance of at least 15MB/s for
4016a 256MB file using 10MB write buffer.</li>
4017 <li><strong>Random read</strong>. Device implementations MUST ensure a random read performance of at least 3.5MB/s for a
4018256MB file using 4KB write buffer.</li>
4019</ul>
4020
4021<h1 id="9_security_model_compatibility">9. Security Model Compatibility</h1>
4022
4023
4024<p>Device implementations MUST implement a security model consistent with the
4025Android platform security model as defined in Security and Permissions
4026reference 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
4027installation of self-signed applications without requiring any additional
4028permissions/certificates from any third parties/authorities. Specifically,
4029compatible devices MUST support the security mechanisms described in the follow
4030subsections.</p>
4031
4032<h2 id="9_1_permissions">9.1. Permissions</h2>
4033
4034
4035<p>Device implementations MUST support the Android permissions model as defined in
4036the 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
4037described in the SDK documentation; no permissions may be omitted, altered, or
4038ignored. Implementations MAY add additional permissions, provided the new
4039permission ID strings are not in the android.* namespace.</p>
4040
4041<h2 id="9_2_uid_and_process_isolation">9.2. UID and Process Isolation</h2>
4042
4043
4044<p>Device implementations MUST support the Android application sandbox model, in
4045which each application runs as a unique Unixstyle UID and in a separate
4046process. Device implementations MUST support running multiple applications as
4047the same Linux user ID, provided that the applications are properly signed and
4048constructed, as defined in the Security and Permissions reference [<a href="http://developer.android.com/guide/topics/security/permissions.html">Resources, 102</a>].</p>
4049
4050<h2 id="9_3_filesystem_permissions">9.3. Filesystem Permissions</h2>
4051
4052
4053<p>Device implementations MUST support the Android file access permissions model
4054as defined in the Security and Permissions reference [<a href="http://developer.android.com/guide/topics/security/permissions.html">Resources, 102</a>].</p>
4055
4056<h2 id="9_4_alternate_execution_environments">9.4. Alternate Execution Environments</h2>
4057
4058
4059<p>Device implementations MAY include runtime environments that execute
4060applications using some other software or technology than the Dalvik Executable
4061Format or native code. However, such alternate execution environments MUST NOT
4062compromise the Android security model or the security of installed Android
4063applications, as described in this section.</p>
4064
4065<p>Alternate runtimes MUST themselves be Android applications, and abide by the
4066standard Android security model, as described elsewhere in <a href="#9_security_model_compatibility">section 9</a>.</p>
4067
4068<p>Alternate runtimes MUST NOT be granted access to resources protected by
4069permissions not requested in the runtime&rsquo;s AndroidManifest.xml file via the
4070<uses-permission> mechanism.</p>
4071
4072<p>Alternate runtimes MUST NOT permit applications to make use of features
4073protected by Android permissions restricted to system applications.</p>
4074
4075<p>Alternate runtimes MUST abide by the Android sandbox model. Specifically,
4076alternate runtimes:</p>
4077
4078<ul>
4079 <li>SHOULD install apps via the PackageManager into separate Android sandboxes (
4080Linux user IDs, etc.).</li>
4081 <li>MAY provide a single Android sandbox shared by all applications using the
4082alternate runtime.</li>
4083 <li>and installed applications using an alternate runtime, MUST NOT reuse the
4084sandbox of any other app installed on the device, except through the standard
4085Android mechanisms of shared user ID and signing certificate.</li>
4086 <li>MUST NOT launch with, grant, or be granted access to the sandboxes
4087corresponding to other Android applications.</li>
4088 <li>MUST NOT be launched with, be granted, or grant to other applications any
4089privileges of the superuser (root), or of any other user ID.</li>
4090</ul>
4091
4092<p>The .apk files of alternate runtimes MAY be included in the system image of a
4093device implementation, but MUST be signed with a key distinct from the key used
4094to sign other applications included with the device implementation.</p>
4095
4096<p>When installing applications, alternate runtimes MUST obtain user consent for
4097the Android permissions used by the application. If an application needs to
4098make use of a device resource for which there is a corresponding Android
4099permission (such as Camera, GPS, etc.), the alternate runtime MUST inform the
4100user that the application will be able to access that resource. If the runtime
4101environment does not record application capabilities in this manner, the
4102runtime environment MUST list all permissions held by the runtime itself when
4103installing any application using that runtime.</p>
4104
4105<h2 id="9_5_multi-user_support">9.5. Multi-User Support</h2>
4106
4107<div class="note">
4108<p>This feature is optional for all device types.</p>
4109</div>
4110
4111
4112<p>Android includes support for multiple users and provides support for full user
4113isolation [<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
4114the following requirements related to multi-user support [<a href="http://source.android.com/devices/storage/">Resources, 104</a>]:</p>
4115
4116<ul>
4117 <li>Device implementations that do not declare the android.hardware.telephony
4118feature flag MUST support restricted profiles, a feature that allows device
4119owners to manage additional users and their capabilities on the device. With
4120restricted profiles, device owners can quickly set up separate environments for
4121additional users to work in, with the ability to manage finer-grained
4122restrictions in the apps that are available in those environments.</li>
4123 <li>Conversely device implementations that declare the android.hardware.telephony
4124feature flag MUST NOT support restricted profiles but MUST align with the AOSP
4125implementation of controls to enable /disable other users from accessing the
4126voice calls and SMS.</li>
4127 <li>Device implementations MUST, for each user, implement a security model
4128consistent with the Android platform security model as defined in Security and
4129Permissions reference document in the APIs [<a href="http://developer.android.com/guide/topics/security/permissions.html">Resources, 102</a>].</li>
4130 <li>Device implementations MAY support creating users and managed profiles via the
4131android.app.admin.DevicePolicyManager APIs, and if supported, MUST declare the
4132platform feature flag android.software.managed_users.
4133 <li>Device implementations that declare the feature flag
4134android.software.managed_users MUST use the upstream AOSP icon badge to
4135represent the managed applications and other badge UI elements like Recents &
4136Notifications.</li>
4137 <li>Each user instance on an Android device MUST have separate and isolated
4138external storage directories. Device implementations MAY store multiple users'
4139data on the same volume or filesystem. However, the device implementation MUST
4140ensure that applications owned by and running on behalf a given user cannot
4141list, read, or write to data owned by any other user. Note that removable
4142media, such as SD card slots, can allow one user to access another&rsquo;s data by
4143means of a host PC. For this reason, device implementations that use removable
4144media for the external storage APIs MUST encrypt the contents of the SD card if
4145multiuser is enabled using a key stored only on non-removable media accessible
4146only to the system. As this will make the media unreadable by a host PC, device
4147implementations will be required to switch to MTP or a similar system to
4148provide host PCs with access to the current user&rsquo;s data. Accordingly, device
4149implementations MAY but SHOULD NOT enable multi-user if they use removable
4150media [<a href="http://developer.android.com/reference/android/os/Environment.html">Resources, 105</a>] for primary external storage.</li>
4151</ul>
4152
4153<h2 id="9_6_premium_sms_warning">9.6. Premium SMS Warning</h2>
4154
4155
4156<p>Android includes support for warning users of any outgoing premium SMS message
4157[<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
4158carrier that may incur a charge to the user. Device implementations that
4159declare support for android.hardware.telephony MUST warn users before sending a
4160SMS message to numbers identified by regular expressions defined in
4161/data/misc/sms/codes.xml file in the device. The upstream Android Open Source
4162Project provides an implementation that satisfies this requirement.</p>
4163
4164<h2 id="9_7_kernel_security_features">9.7. Kernel Security Features</h2>
4165
4166
4167<p>The Android Sandbox includes features that can use the Security-Enhanced Linux
4168(SELinux) mandatory access control (MAC) system and other security features in
4169the Linux kernel. SELinux or any other security features, if implemented below
4170the Android framework:</p>
4171
4172<ul>
4173 <li>MUST maintain compatibility with existing applications.</li>
4174 <li>MUST NOT have a visible user interface when a security violation is detected
4175and successfully blocked, but MAY have a visible user interface when an
4176unblocked security violation occurs resulting in a successful exploit.</li>
4177 <li>SHOULD NOT be user or developer configurable.</li>
4178</ul>
4179
4180<p>If any API for configuration of policy is exposed to an application that can
4181affect another application (such as a Device Administration API), the API MUST
4182NOT allow configurations that break compatibility.</p>
4183
4184<p>Devices MUST implement SELinux or an equivalent mandatory access control system
4185if using a kernel other than Linux and meet the following requirements, which
4186are satisfied by the reference implementation in the upstream Android Open
4187Source Project.</p>
4188
4189<p>Device implementations:</p>
4190
4191<ul>
4192 <li>MUST support a SELinux policy that allows the SELinux mode to be set on a
4193per-domain basis, and MUST configure all domains in enforcing mode. No
4194permissive mode domains are allowed, including domains specific to a
4195device/vendor.</li>
4196 <li>SHOULD load policy from /sepolicy file on the device.</li>
4197 <li>MUST NOT modify, omit, or replace the neverallow rules present within the
4198sepolicy file provided in the upstream Android Open Source Project (AOSP) and
4199the policy MUST compile with all neverallow present, for both AOSP SELinux
4200domains as well as device/vendor specific domains.</li>
4201 <li>MUST support dynamic updates of the SELinux policy file without requiring a
4202system image update.</li>
4203</ul>
4204
4205<p>Device implementations SHOULD retain the default SELinux policy provided in the
4206upstream Android Open Source Project, until they have first audited their
4207additions to the SELinux policy. Device implementations MUST be compatible with
4208the upstream Android Open Source Project.</p>
4209
4210<h2 id="9_8_privacy">9.8. Privacy</h2>
4211
4212<p>If the device implements functionality in the system that captures the contents
4213displayed on the screen and/or records the audio stream played on the device,
4214it MUST continuously notify the user whenever this functionality is enabled and
4215actively capturing/recording.</p>
4216
4217<p>If a device implementation has a mechanism that routes network data traffic
4218through a proxy server or VPN gateway by default (for example, preloading a VPN
4219service with android.permission.CONTROL_VPN granted), the device implementation
4220MUST ask for the user's consent before enabling that mechanism.</p>
4221
4222<h2 id="9_9_full-disk_encryption">9.9. Full-Disk Encryption</h2>
4223
4224<div class="note">
4225<p>Optional for Android device implementations without a lock screen.</p>
4226</div>
4227
4228
4229<p>If the device implementation supports a lock screen with PIN (numeric) or
4230PASSWORD (alphanumeric), the device MUST support full-disk encryption of the
4231application private data (/data partition), as well
4232as the SD card partition if it is a permanent, non-removable part of the device
4233[<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
4234be enabled all the time after the user has completed the out-of-box experience.
4235While this requirement is stated as SHOULD for this version of the Android
4236platform, it is <strong>very strongly RECOMMENDED</strong> as we expect this to change to MUST in the future versions of Android.
4237Encryption MUST use AES with a key of 128-bits (or greater) and a mode designed
4238for storage (for example, AES-XTS, AES-CBC-ESSIV). The encryption key MUST NOT
4239be written to storage at any time without being encrypted. Other than when in
4240active use, the encryption key SHOULD be AES encrypted with the lockscreen
4241passcode stretched using a slow stretching algorithm (e.g. PBKDF2 or scrypt).
4242If the user has not specified a lockscreen passcode or has disabled use of the
4243passcode for encryption, the system SHOULD use a default passcode to wrap the
4244encryption key. If the device provides a hardware-backed keystore, the password
4245stretching algorithm MUST be cryptographically bound to that keystore. The
4246encryption key MUST NOT be sent off the device (even when wrapped with the user
4247passcode and/or hardware bound key). The upstream Android Open Source project
4248provides a preferred implementation of this feature based on the linux kernel
4249feature dm-crypt.</p>
4250
4251<h2 id="9_10_verified_boot">9.10. Verified Boot</h2>
4252
4253<p>
4254Verified boot is a feature that guarantees the integrity of the device software.
4255If a device implementation supports the feature, it MUST:
4256<ul>
4257<li>Declare the platform feature flag android.software.verified_boot</li>
4258<li>Perform verification on every boot sequence</li>
4259<li>Start verification from a hardware key that is the root of trust, and go
4260all the way up to the system partition</li>
4261<li>Implement each stage of verification to check the integrity and authenticity
4262of all the bytes in the next stage before executing the code in the next stage</li>
4263<li>Use verification algorithms as strong as current recommendations
4264from NIST for hashing algorithms (SHA-256) and public key sizes (RSA-2048)</li>
4265</ul>
4266</p>
4267
4268<p>Device implementations SHOULD support verified boot for device integrity.
4269While this requirement is SHOULD for this version of the Android platform,
4270it is <strong>strongly RECOMMENDED</strong> as we expect this to change to MUST
4271in future versions of Android. The upstream Android Open Source Project provides
4272a preferred implementation of this feature based on the linux kernel feature dm-verity.
4273</p>
4274
4275<h1 id="10_software_compatibility_testing">10. Software Compatibility Testing</h1>
4276
4277
4278<p>Device implementations MUST pass all tests described in this section.</p>
4279
4280<p>However, note that no software test package is fully comprehensive. For this
4281reason, device implementers are <strong>very strongly encouraged</strong> to make the minimum number of changes as possible to the reference and
4282preferred implementation of Android available from the Android Open Source
4283Project. This will minimize the risk of introducing bugs that create
4284incompatibilities requiring rework and potential device updates.</p>
4285
4286<h2 id="10_1_compatibility_test_suite">10.1. Compatibility Test Suite</h2>
4287
4288
4289<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
4290software on the device. Additionally, device implementers SHOULD use the
4291reference implementation in the Android Open Source tree as much as possible,
4292and MUST ensure compatibility in cases of ambiguity in CTS and for any
4293reimplementations of parts of the reference source code.</p>
4294
4295<p>The CTS is designed to be run on an actual device. Like any software, the CTS
4296may itself contain bugs. The CTS will be versioned independently of this
4297Compatibility Definition, and multiple revisions of the CTS may be released for
4298Android ANDROID_VERSION. Device implementations MUST pass the latest CTS version available
4299at the time the device software is completed.</p>
4300
4301<h2 id="10_2_cts_verifier">10.2. CTS Verifier</h2>
4302
4303
4304<p>Device implementations MUST correctly execute all applicable cases in the CTS
4305Verifier. The CTS Verifier is included with the Compatibility Test Suite, and
4306is intended to be run by a human operator to test functionality that cannot be
4307tested by an automated system, such as correct functioning of a camera and
4308sensors.</p>
4309
4310<p>The CTS Verifier has tests for many kinds of hardware, including some hardware
4311that is optional. Device implementations MUST pass all tests for hardware that
4312they possess; for instance, if a device possesses an accelerometer, it MUST
4313correctly execute the Accelerometer test case in the CTS Verifier. Test cases
4314for features noted as optional by this Compatibility Definition Document MAY be
4315skipped or omitted.</p>
4316
4317<p>Every device and every build MUST correctly run the CTS Verifier, as noted
4318above. However, since many builds are very similar, device implementers are not
4319expected to explicitly run the CTS Verifier on builds that differ only in
4320trivial ways. Specifically, device implementations that differ from an
4321implementation that has passed the CTS Verifier only by the set of included
4322locales, branding, etc. MAY omit the CTS Verifier test.</p>
4323
4324<h1 id="11_updatable_software">11. Updatable Software</h1>
4325
4326
4327<p>Device implementations MUST include a mechanism to replace the entirety of the
4328system software. The mechanism need not perform &ldquo;live&rdquo; upgrades&mdash;that is, a
4329device restart MAY be required.</p>
4330
4331<p>Any method can be used, provided that it can replace the entirety of the
4332software preinstalled on the device. For instance, any of the following
4333approaches will satisfy this requirement:</p>
4334
4335<ul>
4336 <li>&ldquo;Over-the-air (OTA)&rdquo; downloads with offline update via reboot</li>
4337 <li>&ldquo;Tethered&rdquo; updates over USB from a host PC</li>
4338 <li>&ldquo;Offline&rdquo; updates via a reboot and update from a file on removable storage</li>
4339</ul>
4340
4341<p>However, if the device implementation includes support for an unmetered data
4342connection such as 802.11 or Bluetooth PAN (Personal Area Network) profile:</p>
4343
4344<ul>
4345<li>Android Automotive implementations SHOULD support OTA downloads with offline
4346update via reboot.</li>
4347<li>All other device implementations MUST support OTA downloads with offline
4348update via reboot.</li>
4349</ul>
4350
4351<p>The update mechanism used MUST support updates without wiping user data. That
4352is, the update mechanism MUST preserve application private data and application
4353shared data. Note that the upstream Android software includes an update
4354mechanism that satisfies this requirement.</p>
4355
4356<p>For device implementations that are launching with Android ANDROID_VERSION and later, the
4357update mechanism SHOULD support verifying that the system image is binary
4358identical to expected result following an OTA. The block-based OTA
4359implementation in the upstream Android Open Source Project, added since Android
43605.1, satisfies this requirement.</p>
4361
4362<p>If an error is found in a device implementation after it has been released but
4363within its reasonable product lifetime that is determined in consultation with
4364the Android Compatibility Team to affect the compatibility of third-party
4365applications, the device implementer MUST correct the error via a software
4366update available that can be applied per the mechanism just described.</p>
4367
4368<h1 id="12_document_changelog">12. Document Changelog</h1>
4369
4370
4371<p>The following table contains a summary of the changes to the Compatibility
4372Definition in this release. </p>
4373<table>
4374 <tr>
4375 <th>Section</th>
4376 <th>Summary of change</th>
4377 </tr>
4378 <tr>
4379 <td>2. Device Types</td>
4380 <td>Added definition for Android automotive implementation.</td>
4381 </tr>
4382 <tr>
4383 <td>2.1 Device Configurations</td>
4384 <td>Added column for Android automotive implementation.</td>
4385 </tr>
4386 <tr>
4387 <td>3.3.2. 32-bit ARM Native Code Compatibility</td>
4388 <td>New section added.</td>
4389 </tr>
4390 <tr>
4391 <td>3.4.1. WebView Compatibility</td>
4392 <td>Updated webview user agent string requirement to accomodate upstream
4393 implementation change.</td>
4394 </tr>
4395 <tr>
4396 <td>3.4.2. Browser compatibility</td>
4397 <td>Added Android automotive implementations as another case that MAY omit a
4398 browser application.</td>
4399 </tr>
4400 <tr>
4401 <td>3.7. Runtime Compatibility</td>
4402 <td>Updated required runtime heap size for smaller screens and added requirement
4403 for the new dpi bucket (280dpi).</td>
4404 </tr>
4405 <tr>
4406 <td>3.8.3. Notifications</td>
4407 <td>Clarified notification requirement for Android Watch, Television and
4408 Automotive implementations.</td>
4409 </tr>
4410 <tr>
4411 <td>3.8.10. Lock Screen Media Control<</td>
4412 <td>Clarified requirement for Android Watch and Automotive implementations.</td>
4413 </tr>
4414 <tr>
4415 <td>3.8.13. Unicode and font</td>
4416 <td>Relaxed Emoji character input method requirement.</td>
4417 </tr>
4418 <tr>
4419 <td>3.9. Device Administration</td>
4420 <td>Clarified condition when the full range of device administration policies
4421 has to be supported.</td>
4422 </tr>
4423 <tr>
4424 <td>3.10. Accessibility</td>
4425 <td>Added Android automotive requirements.</td>
4426 </tr>
4427 <tr>
4428 <td>3.11. Text-To-Speech</td>
4429 <td>Added Android automotive requirements.</td>
4430 </tr>
4431 <tr>
4432 <td>5.1. Media Codecs</td>
4433 <td>Mandated decoding support for codecs reported by CamcorderProfile.</td>
4434 </tr>
4435 <tr>
4436 <td>5.1.3 Video Codecs</td>
4437 <td>Added Android automotive requirements.</td>
4438 </tr>
4439 <tr>
4440 <td>7.1.1.3. Screen Density</td>
4441 <td>Added a new screen dpi (280dpi).</td>
4442 </tr>
4443 <tr>
4444 <td>7.1.5. Legacy Application Compatibility Mode</td>
4445 <td>Added Android automotive requirements.</td>
4446 </tr>
4447 <tr>
4448 <td>7.2 Input Devices</td>
4449 <td>Added general introduction statement.</td>
4450 </tr>
4451 <tr>
4452 <td>7.2.1. Keyboard</td>
4453 <td>Added Android Automotive requirements.</td>
4454 </tr>
4455 <tr>
4456 <td>7.2.3. Navigation Keys</td>
4457 <td>Added Android Automotive requirements.</td>
4458 </tr>
4459 <tr>
4460 <td>7.3.1. Accelerometer</td>
4461 <td>Relaxed requirement for reporting frequency on Android Watch.</td>
4462 </tr>
4463 <tr>
4464 <td>7.3.4. Gyroscope</td>
4465 <td>Relaxed requirement for reporting frequency on Android Watch.</td>
4466 </tr>
4467 <tr>
4468 <td>7.4.3 Bluetooth</td>
4469 <td>Added Android Automotive requirements.</td>
4470 </tr>
4471 <tr>
4472 <td>7.4.4. Near-Field Communications</td>
4473 <td>Clarified condition for when Host Card Emulation is a requirement.</td>
4474 </tr>
4475 <tr>
4476 <td>7.6.1. Minimum Memory and Storage</td>
4477 <td>Updated minimum memory requirements for lower resulution screen devices
4478 and added hard-limit requirement isLowRamDevice().</td>
4479 </tr>
4480 <tr>
4481 <td>7.6.2. Application Shared Storage</td>
4482 <td>Updated requirements when support for host machine access is mandatory.</td>
4483 </tr>
4484 <tr>
4485 <td>7.8.1. Microphone</td>
4486 <td>Added Android Automotive requirements.</td>
4487 </tr>
4488 <tr>
4489 <td>8.2. File I/O Access Performance</td>
4490 <td>Clarified requirements.</td>
4491 </tr>
4492 <tr>
4493 <td>9.8. Privacy</td>
4494 <td>Added privacy requirement for preloaded VPNs.</td>
4495 </tr>
4496 <tr>
4497 <td>9.9. Full-Disk Encryption</td>
4498 <td>Clarified condition when Full-Disk encryption support is mandatory.</td>
4499 </tr>
4500 <tr>
4501 <td>9.10. Verified Boot</td>
4502 <td>Clarified definition of verified boot.</td>
4503 </tr>
4504 <tr>
4505 <td>11. Updatable Software</td>
4506 <td>Clarified the OTA download requirement is allowed but not mandatory for
4507 Android Automotive implementations.</td>
4508 </tr>
4509</table>
4510
4511
4512<h1 id="13_contact_us">13. Contact Us</h1>
4513
4514
4515<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
4516does not cover.</p>
4517
4518<h1 id="14_resources">14. Resources</h1>
4519
4520
4521<p>1. IETF RFC2119 Requirement Levels: <a href="http://www.ietf.org/rfc/rfc2119.txt">http://www.ietf.org/rfc/rfc2119.txt</a></p>
4522
4523<p>2. Android Open Source Project: <a href="http://source.android.com/">http://source.android.com/</a></p>
4524
4525<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>
4526
4527<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>
4528
4529<p>5. API definitions and documentation: <a href="http://developer.android.com/reference/packages.html">http://developer.android.com/reference/packages.html</a></p>
4530
4531<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>
4532
4533<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>
4534
4535<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>
4536
4537<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>
4538
4539<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>
4540
4541<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>
4542
4543<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>
4544
4545<p>13. WebView compatibility: <a href="http://www.chromium.org/">http://www.chromium.org/</a></p>
4546
4547<p>14. HTML5: <a href="http://html.spec.whatwg.org/multipage/">http://html.spec.whatwg.org/multipage/</a></p>
4548
4549<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>
4550
4551<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>
4552
4553<p>17. HTML5/W3C geolocation API: <a href="http://www.w3.org/TR/geolocation-API/">http://www.w3.org/TR/geolocation-API/</a></p>
4554
4555<p>18. HTML5/W3C webstorage API: <a href="http://www.w3.org/TR/webstorage/">http://www.w3.org/TR/webstorage/</a></p>
4556
4557<p>19. HTML5/W3C IndexedDB API: <a href="http://www.w3.org/TR/IndexedDB/">http://www.w3.org/TR/IndexedDB/</a></p>
4558
4559<p>20. Dalvik Executable Format and bytecode specification: available in the
4560Android source code, at dalvik/docs</p>
4561
4562<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>
4563
4564<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>
4565
4566<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>
4567
4568<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>
4569
4570<p>25. Notifications Resources: <a href="https://developer.android.com/design/patterns/notifications.html">https://developer.android.com/design/patterns/notifications.html</a> </p>
4571
4572<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>
4573
4574<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>
4575
4576<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>
4577
4578<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>
4579
4580<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>
4581
4582<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>
4583
4584<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>
4585
4586<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>
4587
4588<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>
4589
4590<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>
4591
4592<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>
4593
4594<p>37. Settings.Secure LOCATION_MODE:</p>
4595
4596<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>
4597
4598<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>
4599
4600<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>
4601
4602<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>
4603
4604<p>41. Android Device Owner App:</p>
4605
4606<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>
4607
4608<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>
4609
4610<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>
4611
4612<p>44. Eyes Free project: <a href="http://code.google.com/p/eyes-free/">http://code.google.com/p/eyes-free</a></p>
4613
4614<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>
4615
4616<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>
4617
4618<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>
4619
4620<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>
4621
4622<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>
4623
4624<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>
4625
4626<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>
4627
4628<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>
4629
4630<p>53. Android android.content.pm.PackageManager class and Hardware Features List:</p>
4631
4632<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>
4633
4634<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>
4635
4636<p>55. ADB: <a href="http://developer.android.com/tools/help/adb.html">http://developer.android.com/tools/help/adb.html</a> </p>
4637
4638<p>56. Dumpsys: <a href="https://source.android.com/devices/input/diagnostics.html">https://source.android.com/devices/input/diagnostics.html</a> </p>
4639
4640<p>57. DDMS: <a href="http://developer.android.com/tools/debugging/ddms.html">http://developer.android.com/tools/debugging/ddms.html</a> </p>
4641
4642<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>
4643
4644<p>59. SysyTrace tool: <a href="http://developer.android.com/tools/help/systrace.html">http://developer.android.com/tools/help/systrace.html</a></p>
4645
4646<p>60. Android Application Development-Related Settings:</p>
4647
4648<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>
4649
4650<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>
4651
4652<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>
4653
4654<p>63. RenderScript: <a href="http://developer.android.com/guide/topics/renderscript/">http://developer.android.com/guide/topics/renderscript/</a></p>
4655
4656<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>
4657
4658<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>
4659
4660<p>66. EGL Extension-EGL_ANDROID_RECORDABLE:</p>
4661
4662<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>
4663
4664<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>
4665
4666<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>
4667
4668<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>
4669
4670<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>
4671
4672<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>
4673
4674<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>
4675
4676<p>73. Android Open Source sensors: <a href="http://source.android.com/devices/sensors/">http://source.android.com/devices/sensors</a></p>
4677
4678<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>
4679
4680<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>
4681
4682<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>
4683
4684<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>
4685
4686<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>
4687
4688<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>
4689
4690<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>
4691
4692<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>
4693
4694<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>
4695
4696<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>
4697
4698<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>
4699
4700<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>
4701
4702<p>86. Android NFC Sharing Settings:</p>
4703
4704<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>
4705
4706<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>
4707
4708<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>
4709
4710<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>
4711
4712<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>
4713
4714<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>
4715
4716<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>
4717
4718<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>
4719
4720<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>
4721
4722<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>
4723
4724<p>96. Android File Transfer: <a href="http://www.android.com/filetransfer">http://www.android.com/filetransfer</a></p>
4725
4726<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>
4727
4728<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>
4729
4730<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>
4731
4732<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>
4733
4734<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>
4735
4736<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>
4737
4738<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>
4739
4740<p>104. External Storage reference: <a href="http://source.android.com/devices/storage">http://source.android.com/devices/storage</a></p>
4741
4742<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>
4743
4744<p>106. SMS Short Code: <a href="http://en.wikipedia.org/wiki/Short_code">http://en.wikipedia.org/wiki/Short_code</a></p>
4745
4746<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>
4747
4748<p>108. Android Compatibility Program Overview: <a href="http://source.android.com/compatibility/index.html">http://source.android.com/compatibility/index.html</a></p>
4749
4750<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>
4751
4752<p>110. WebM project: <a href="http://www.webmproject.org/">http://www.webmproject.org/</a> </p>
4753
4754<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>
4755
4756<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>
4757
4758<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>
4759
4760<p>Many of these resources are derived directly or indirectly from the Android
4761SDK, and will be functionally identical to the information in that SDK&rsquo;s
4762documentation. In any cases where this Compatibility Definition or the
4763Compatibility Test Suite disagrees with the SDK documentation, the SDK
4764documentation is considered authoritative. Any technical details provided in
4765the references included above are considered by inclusion to be part of this
4766Compatibility Definition.</p>
4767
4768</div>
4769</body>
4770</html>