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Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]1<!DOCTYPE html>
2<head>
3<title>Android ANDROID_VERSION Compatibility Definition</title>
Clay Murphyb6581772015-08-26 11:11:06 -0700[diff] [blame]4<link rel="stylesheet" type="text/css" href="source/android-cdd.css"/>
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]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
Bert McMeen15ecb402015-10-01 13:17:55 -0700[diff] [blame]83</div>
84
85<div id="toc_right">
86
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]87<p class="toc_h3"><a href="#3_8_11_dreams">3.8.11. Dreams</a></p>
88
89<p class="toc_h3"><a href="#3_8_12_location">3.8.12. Location</a></p>
90
91<p class="toc_h3"><a href="#3_8_13_unicode_and_font">3.8.13. Unicode and Font</a></p>
92
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]93<p class="toc_h2"><a href="#3_9_device_administration">3.9. Device Administration</a></p>
94
Andy Dyer-smith3d24bbe2015-09-11 15:35:23 +0100[diff] [blame]95<p class="toc_h3"><a href="#3_9_1_device_provisioning">3.9.1 Device Provisioning</a></p>
96
97<p class="toc_h4"><a href="#3_9_1_2_device_owner_provisioning">3.9.1.1 Device Owner provisioning</a></p>
98
99<p class="toc_h4"><a href="#3_9_1_2_managed_profile_provisioning">3.9.1.2 Managed profile provisioning</a></p>
100
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]101<p class="toc_h2"><a href="#3_10_accessibility">3.10. Accessibility</a></p>
102
103<p class="toc_h2"><a href="#3_11_text-to-speech">3.11. Text-to-Speech</a></p>
104
105<p class="toc_h2"><a href="#3_12_tv_input_framework">3.12. TV Input Framework</a></p>
106
107<p class="toc_h1"><a href="#4_application_packaging_compatibility">4. Application Packaging Compatibility</a></p>
108
109<p class="toc_h1"><a href="#5_multimedia_compatibility">5. Multimedia Compatibility</a></p>
110
111<p class="toc_h2"><a href="#5_1_media_codecs">5.1. Media Codecs</a></p>
112
113<p class="toc_h3"><a href="#5_1_1_audio_codecs">5.1.1. Audio Codecs</a></p>
114
115<p class="toc_h3"><a href="#5_1_2_image_codecs">5.1.2. Image Codecs</a></p>
116
117<p class="toc_h3"><a href="#5_1_3_video_codecs">5.1.3. Video Codecs</a></p>
118
119<p class="toc_h2"><a href="#5_2_video_encoding">5.2. Video Encoding</a></p>
120
121<p class="toc_h2"><a href="#5_3_video_decoding">5.3. Video Decoding</a></p>
122
123<p class="toc_h2"><a href="#5_4_audio_recording">5.4. Audio Recording</a></p>
124
125<p class="toc_h3"><a href="#5_4_1_raw_audio_capture">5.4.1. Raw Audio Capture</a></p>
126
127<p class="toc_h3"><a href="#5_4_2_capture_for_voice_recognition">5.4.2. Capture for Voice Recognition</a></p>
128
129<p class="toc_h3"><a href="#5_4_3_capture_for_rerouting_of_playback">5.4.3. Capture for Rerouting of Playback</a></p>
130
131<p class="toc_h2"><a href="#5_5_audio_playback">5.5. Audio Playback</a></p>
132
133<p class="toc_h3"><a href="#5_5_1_raw_audio_playback">5.5.1. Raw Audio Playback</a></p>
134
135<p class="toc_h3"><a href="#5_5_2_audio_effects">5.5.2. Audio Effects</a></p>
136
137<p class="toc_h3"><a href="#5_5_3_audio_output_volume">5.5.3. Audio Output Volume</a></p>
138
139<p class="toc_h2"><a href="#5_6_audio_latency">5.6. Audio Latency</a></p>
140
141<p class="toc_h2"><a href="#5_7_network_protocols">5.7. Network Protocols</a></p>
142
143<p class="toc_h2"><a href="#5_8_secure_media">5.8. Secure Media</a></p>
144
Glenn Kasten87ef61d2015-07-29 09:01:36 -0700[diff] [blame]145<p class="toc_h2"><a href="#5_9_midi">5.9. Musical Instrument Digital Interface (MIDI)</a></p>
146
Glenn Kasten78eccbd2015-08-12 10:18:22 -0700[diff] [blame]147<p class="toc_h2"><a href="#5_10_pro_audio">5.10. Professional Audio</a></p>
148
Bert McMeen15ecb402015-10-01 13:17:55 -0700[diff] [blame]149</div>
150
151<div style="clear: both; page-break-after:always; height:1px"></div>
152
153<div id="toc_left">
154
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]155<p class="toc_h1"><a href="#6_developer_tools_and_options_compatibility">6. Developer Tools and Options Compatibility</a></p>
156
157<p class="toc_h2"><a href="#6_1_developer_tools">6.1. Developer Tools</a></p>
158
159<p class="toc_h2"><a href="#6_2_developer_options">6.2. Developer Options</a></p>
160
161<p class="toc_h1"><a href="#7_hardware_compatibility">7. Hardware Compatibility</a></p>
162
163<p class="toc_h2"><a href="#7_1_display_and_graphics">7.1. Display and Graphics</a></p>
164
165<p class="toc_h3"><a href="#7_1_1_screen_configuration">7.1.1. Screen Configuration</a></p>
166
167<p class="toc_h4"><a href="#7_1_1_1_screen_size">7.1.1.1. Screen Size</a></p>
168
169<p class="toc_h4"><a href="#7_1_1_2_screen_aspect_ratio">7.1.1.2. Screen Aspect Ratio</a></p>
170
171<p class="toc_h4"><a href="#7_1_1_3_screen_density">7.1.1.3. Screen Density</a></p>
172
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]173<p class="toc_h3"><a href="#7_1_2_display_metrics">7.1.2. Display Metrics</a></p>
174
175<p class="toc_h3"><a href="#7_1_3_screen_orientation">7.1.3. Screen Orientation</a></p>
176
177<p class="toc_h3"><a href="#7_1_4_2d_and_3d_graphics_acceleration">7.1.4. 2D and 3D Graphics Acceleration</a></p>
178
179<p class="toc_h3"><a href="#7_1_5_legacy_application_compatibility_mode">7.1.5. Legacy Application Compatibility Mode</a></p>
180
181<p class="toc_h3"><a href="#7_1_6_screen_technology">7.1.6. Screen Technology</a></p>
182
183<p class="toc_h3"><a href="#7_1_7_external_displays">7.1.7. Secondary Displays</a></p>
184
185<p class="toc_h2"><a href="#7_2_input_devices">7.2. Input Devices</a></p>
186
187<p class="toc_h3"><a href="#7_2_1_keyboard">7.2.1. Keyboard</a></p>
188
189<p class="toc_h3"><a href="#7_2_2_non-touch_navigation">7.2.2. Non-touch Navigation</a></p>
190
191<p class="toc_h3"><a href="#7_2_3_navigation_keys">7.2.3. Navigation Keys</a></p>
192
193<p class="toc_h3"><a href="#7_2_4_touchscreen_input">7.2.4. Touchscreen Input</a></p>
194
195<p class="toc_h3"><a href="#7_2_5_fake_touch_input">7.2.5. Fake Touch Input</a></p>
196
197<p class="toc_h3"><a href="#7_2_6_game_controller_support">7.2.6. Game Controller Support</a></p>
198
199<p class="toc_h4"><a href="#7_2_6_1_button_mapping">7.2.6.1. Button Mappings</a></p>
200
201<p class="toc_h3"><a href="#7_2_7_remote_control">7.2.7. Remote Control</a></p>
202
203<p class="toc_h2"><a href="#7_3_sensors">7.3. Sensors</a></p>
204
205<p class="toc_h3"><a href="#7_3_1_accelerometer">7.3.1. Accelerometer</a></p>
206
207<p class="toc_h3"><a href="#7_3_2_magnetometer">7.3.2. Magnetometer</a></p>
208
209<p class="toc_h3"><a href="#7_3_3_gps">7.3.3. GPS</a></p>
210
Bert McMeen15ecb402015-10-01 13:17:55 -0700[diff] [blame]211</div>
212
213<div id="toc_right">
214
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]215<p class="toc_h3"><a href="#7_3_4_gyroscope">7.3.4. Gyroscope</a></p>
216
217<p class="toc_h3"><a href="#7_3_5_barometer">7.3.5. Barometer</a></p>
218
219<p class="toc_h3"><a href="#7_3_6_thermometer">7.3.6. Thermometer</a></p>
220
221<p class="toc_h3"><a href="#7_3_7_photometer">7.3.7. Photometer</a></p>
222
223<p class="toc_h3"><a href="#7_3_8_proximity_sensor">7.3.8. Proximity Sensor</a></p>
224
225<p class="toc_h2"><a href="#7_4_data_connectivity">7.4. Data Connectivity</a></p>
226
227<p class="toc_h3"><a href="#7_4_1_telephony">7.4.1. Telephony</a></p>
228
229<p class="toc_h3"><a href="#7_4_2_ieee_80211_wi-fi">7.4.2. IEEE 802.11 (Wi-Fi)</a></p>
230
231<p class="toc_h4"><a href="#7_4_2_1_wi-fi_direct">7.4.2.1. Wi-Fi Direct</a></p>
232
233<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>
234
235<p class="toc_h3"><a href="#7_4_3_bluetooth">7.4.3. Bluetooth</a></p>
236
237<p class="toc_h3"><a href="#7_4_4_near-field_communications">7.4.4. Near-Field Communications</a></p>
238
239<p class="toc_h3"><a href="#7_4_5_minimum_network_capability">7.4.5. Minimum Network Capability</a></p>
240
241<p class="toc_h3"><a href="#7_4_6_sync_settings">7.4.6. Sync Settings</a></p>
242
243<p class="toc_h2"><a href="#7_5_cameras">7.5. Cameras</a></p>
244
245<p class="toc_h3"><a href="#7_5_1_rear-facing_camera">7.5.1. Rear-Facing Camera</a></p>
246
247<p class="toc_h3"><a href="#7_5_2_front-facing_camera">7.5.2. Front-Facing Camera</a></p>
248
249<p class="toc_h3"><a href="#7_5_3_external_camera">7.5.3. External Camera</a></p>
250
251<p class="toc_h3"><a href="#7_5_4_camera_api_behavior">7.5.4. Camera API Behavior</a></p>
252
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]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
Glenn Kasten20cdbb72015-09-24 11:56:42 -0700[diff] [blame]271<p class="toc_h3"><a href="#7_8_3_near_ultrasound">7.8.3. Near-Ultrasound</a></p>
272
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]273<p class="toc_h1"><a href="#8_performance_compatibility">8. Performance Compatibility</a></p>
274
275<p class="toc_h2"><a href="#8_1_user_experience_consistency">8.1. User Experience Consistency</a></p>
276
277<p class="toc_h2"><a href="#8_2_memory_performance">8.2. Memory Performance</a></p>
278
Bert McMeen15ecb402015-10-01 13:17:55 -0700[diff] [blame]279</div>
280
281<div style="clear: both; page-break-after:always; height:1px"></div>
282
283<div id="toc_left">
284
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]285<p class="toc_h1"><a href="#9_security_model_compatibility">9. Security Model Compatibility</a></p>
286
287<p class="toc_h2"><a href="#9_1_permissions">9.1. Permissions</a></p>
288
289<p class="toc_h2"><a href="#9_2_uid_and_process_isolation">9.2. UID and Process Isolation</a></p>
290
291<p class="toc_h2"><a href="#9_3_filesystem_permissions">9.3. Filesystem Permissions</a></p>
292
293<p class="toc_h2"><a href="#9_4_alternate_execution_environments">9.4. Alternate Execution Environments</a></p>
294
295<p class="toc_h2"><a href="#9_5_multi-user_support">9.5. Multi-User Support</a></p>
296
297<p class="toc_h2"><a href="#9_6_premium_sms_warning">9.6. Premium SMS Warning</a></p>
298
299<p class="toc_h2"><a href="#9_7_kernel_security_features">9.7. Kernel Security Features</a></p>
300
301<p class="toc_h2"><a href="#9_8_privacy">9.8. Privacy</a></p>
302
303<p class="toc_h2"><a href="#9_9_full-disk-encryption">9.9. Full-Disk Encryption</a></p>
304
305<p class="toc_h2"><a href="#9_10_verified_boot">9.10. Verified Boot</a></p>
306
307<p class="toc_h1"><a href="#10_software_compatibility_testing">10. Software Compatibility Testing</a></p>
308
309<p class="toc_h2"><a href="#10_1_compatibility_test_suite">10.1. Compatibility Test Suite</a></p>
310
311<p class="toc_h2"><a href="#10_2_cts_verifier">10.2. CTS Verifier</a></p>
312
313<p class="toc_h1"><a href="#11_updatable_software">11. Updatable Software</a></p>
314
315<p class="toc_h1"><a href="#12_document_changelog">12. Document Changelog</a></p>
316
317<p class="toc_h1"><a href="#13_contact_us">13. Contact Us</a></p>
318
319<p class="toc_h1"><a href="#14_resources">14. Resources</a></p>
320
321</div>
322
323</div>
324
325<div style="clear: both"></div>
326
327<div id="main">
328
329<h1 id="1_introduction">1. Introduction</h1>
330
331
332<p>This document enumerates the requirements that must be met in order for devices
333to be compatible with Android ANDROID_VERSION.</p>
334
335<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
336defined in RFC2119 [<a href="http://www.ietf.org/rfc/rfc2119.txt">Resources, 1</a>].</p>
337
338<p>As used in this document, a &ldquo;device implementer&rdquo; or &ldquo;implementer&rdquo; is a person
339or organization developing a hardware/software solution running Android ANDROID_VERSION. A
340&ldquo;device implementation&rdquo; or &ldquo;implementation is the hardware/software solution
341so developed.</p>
342
343<p>To be considered compatible with Android ANDROID_VERSION, device implementations MUST meet
344the requirements presented in this Compatibility Definition, including any
345documents incorporated via reference.</p>
346
347<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
348implementer to ensure compatibility with existing implementations.</p>
349
350<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
Bert McMeen816a2422015-09-29 16:33:19 -0700[diff] [blame]351implementers are STRONGLY RECOMMENDED to base their implementations to the
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]352greatest extent possible on the &ldquo;upstream&rdquo; source code available from the
353Android Open Source Project. While some components can hypothetically be
354replaced with alternate implementations this practice is strongly discouraged,
355as passing the software tests will become substantially more difficult. It is
356the implementer&rsquo;s responsibility to ensure full behavioral compatibility with
357the standard Android implementation, including and beyond the Compatibility
358Test Suite. Finally, note that certain component substitutions and
359modifications are explicitly forbidden by this document.</p>
360
361<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
362functionally identical to the information in that SDK&rsquo;s documentation. For any
363case where this Compatibility Definition or the Compatibility Test Suite
364disagrees with the SDK documentation, the SDK documentation is considered
365authoritative. 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>
366
367<h1 id="2_device_types">2. Device Types</h1>
368
369
370<p>While the Android Open Source Project has been used in the implementation of a
371variety of device types and form factors, many aspects of the architecture and
372compatibility requirements were optimized for handheld devices. Starting from
373Android 5.0, the Android Open Source Project aims to embrace a wider variety of
374device types as described in this section.</p>
375
376<p><strong>Android Handheld device</strong> refers to an Android device implementation that is typically used by holding
377it in the hand, such as mp3 players, phones, and tablets. Android Handheld
378device implementations:</p>
379
380<ul>
381 <li>MUST have a touchscreen embedded in the device.</li>
382 <li>MUST have a power source that provides mobility, such as a battery.</li>
383</ul>
384
385<p><strong>Android Television device</strong> refers to an Android device implementation that is an entertainment interface
386for consuming digital media, movies, games, apps, and/or live TV for users
387sitting about ten feet away (a &ldquo;lean back&rdquo; or &ldquo;10-foot user interface&rdquo;).
388Android Television devices:</p>
389
390<ul>
391 <li>MUST have an embedded screen OR include a video output port, such as VGA, HDMI,
392or a wireless port for display.</li>
393 <li>MUST declare the features android.software.leanback and
394android.hardware.type.television [<a href="http://developer.android.com/reference/android/content/pm/PackageManager.html#FEATURE_LEANBACK">Resources, 3</a>].</li>
395</ul>
396
397<p><strong>Android Watch device</strong> refers to an Android device implementation intended to be worn on the body,
398perhaps on the wrist, and:</p>
399
400<ul>
401 <li>MUST have a screen with the physical diagonal length in the range from 1.1 to
4022.5 inches.</li>
403 <li>MUST declare the feature android.hardware.type.watch.</li>
404 <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>
405</ul>
406
407<p><strong>Android Automotive implementation</strong> refers to a vehicle head
408unit running Android as an operating system for part or all of the system and/or
409infotainment functionality. Android Automotive implementations MUST support
410uiMode = UI_MODE_TYPE_CAR [<a href="http://developer.android.com/reference/android/content/res/Configuration.html#UI_MODE_TYPE_CAR">Resources, 111</a>].</p>
411
412<p>All Android device implementations that do not fit into any of the above device
413types still MUST meet all requirements in this document to be Android ANDROID_VERSION
414compatible, unless the requirement is explicitly described to be only
415applicable to a specific Android device type from above.</p>
416
417<h2 id="2_1_device_configurations">2.1 Device Configurations</h2>
418
419
420<p>This is a summary of major differences in hardware configuration by device
421type. (Empty cells denote a &ldquo;MAY&rdquo;). Not all configurations are covered in this
422table; see relevant hardware sections for more detail.</p>
423<table>
424 <tr>
425 <th>Category</th>
426 <th>Feature</th>
427 <th>Section</th>
428 <th>Handheld</th>
429 <th>Television</th>
430 <th>Watch</th>
431 <th>Automotive</th>
432 <th>Other</th>
433 </tr>
434 <tr>
435 <td rowspan="3">Input</td>
436 <td>D-pad</td>
437 <td><a href="#7_2_2_non-touch-navigation">7.2.2. Non-touch Navigation</a></td>
438 <td></td>
439 <td>MUST</td>
440 <td></td>
441 <td></td>
442 <td></td>
443 </tr>
444 <tr>
445 <td>Touchscreen </td>
446 <td><a href="#7_2_4_touchscreen_input">7.2.4. Touchscreen input</a></td>
447 <td>MUST</td>
448 <td></td>
449 <td>MUST</td>
450 <td></td>
451 <td>SHOULD</td>
452 </tr>
453 <tr>
454 <td>Microphone </td>
455 <td><a href="#7_8_1_microphone">7.8.1. Microphone</a></td>
456 <td>MUST</td>
457 <td>SHOULD </td>
458 <td>MUST</td>
459 <td>MUST</td>
460 <td>SHOULD</td>
461 </tr>
462 <tr>
463 <td rowspan="2">Sensors</td>
464 <td>Accelerometer </td>
465 <td><a href="#7_3_1_accelerometer">7.3.1 Accelerometer</a></td>
466 <td>SHOULD</td>
467 <td></td>
468 <td>SHOULD</td>
469 <td></td>
470 <td>SHOULD</td>
471 </tr>
472 <tr>
473 <td>GPS</td>
474 <td><a href="#7_3_3_gps">7.3.3. GPS</a></td>
475 <td>SHOULD</td>
476 <td></td>
477 <td></td>
478 <td>SHOULD</td>
479 <td></td>
480 </tr>
481 <tr>
482 <td rowspan="5">Connectivity</td>
483 <td>Wi-Fi</td>
484 <td><a href="#7_4_2_ieee_802.11">7.4.2. IEEE 802.11</a></td>
485 <td>SHOULD</td>
486 <td> MUST</td>
487 <td></td>
488 <td>SHOULD</td>
489 <td>SHOULD</td>
490 </tr>
491 <tr>
492 <td>Wi-Fi Direct</td>
493 <td><a href="#7_4_2_1_wi-fi-direct">7.4.2.1. Wi-Fi Direct</a></td>
494 <td>SHOULD</td>
495 <td>SHOULD</td>
496 <td></td>
497 <td></td>
498 <td>SHOULD</td>
499 </tr>
500 <tr>
501 <td>Bluetooth</td>
502 <td><a href="#7_4_3_bluetooth">7.4.3. Bluetooth</a></td>
503 <td>SHOULD</td>
504 <td>MUST</td>
505 <td>MUST</td>
506 <td>MUST</td>
507 <td>SHOULD</td>
508 </tr>
509 <tr>
510 <td>Bluetooth Low Energy</td>
511 <td><a href="#7_4_3_bluetooth">7.4.3. Bluetooth</a></td>
512 <td>SHOULD</td>
513 <td>MUST</td>
514 <td>SHOULD</td>
515 <td>SHOULD</td>
516 <td>SHOULD</td>
517 </tr>
518 <tr>
519 <td>USB peripheral/host mode</td>
520 <td><a href="#7_7_usb">7.7. USB</a></td>
521 <td>SHOULD</td>
522 <td></td>
523 <td></td>
524 <td>SHOULD</td>
525 <td>SHOULD</td>
526 </tr>
527 <tr>
528 <td>Output</td>
529 <td>Speaker and/or Audio output ports</td>
530 <td><a href="#7_8_2_audio_output">7.8.2. Audio Output</a></td>
531 <td>MUST</td>
532 <td>MUST</td>
533 <td></td>
534 <td>MUST</td>
535 <td>MUST</td>
536 </tr>
537</table>
538
539
540<h1 id="3_software">3. Software</h1>
541
542
543<h2 id="3_1_managed_api_compatibility">3.1. Managed API Compatibility</h2>
544
545
546<p>The managed Dalvik bytecode execution environment is the primary vehicle for
547Android applications. The Android application programming interface (API) is
548the set of Android platform interfaces exposed to applications running in the
549managed runtime environment. Device implementations MUST provide complete
550implementations, including all documented behaviors, of any documented API
551exposed 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
552source code. </p>
553
554<p>Device implementations MUST NOT omit any managed APIs, alter API interfaces or
555signatures, deviate from the documented behavior, or include no-ops, except
556where specifically allowed by this Compatibility Definition.</p>
557
558<p>This Compatibility Definition permits some types of hardware for which Android
559includes APIs to be omitted by device implementations. In such cases, the APIs
560MUST 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>
561
562<h2 id="3_2_soft_api_compatibility">3.2. Soft API Compatibility</h2>
563
564
565<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
566such things as intents, permissions, and similar aspects of Android
567applications that cannot be enforced at application compile time.</p>
568
569<h3 id="3_2_1_permissions">3.2.1. Permissions</h3>
570
571
572<p>Device implementers MUST support and enforce all permission constants as
573documented 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>
574
575<h3 id="3_2_2_build_parameters">3.2.2. Build Parameters</h3>
576
577
578<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,
579meaningful values across device implementations, the table below includes
580additional restrictions on the formats of these values to which device
581implementations MUST conform.</p>
582<table>
583 <tr>
584 <th>Parameter</th>
585 <th>Details</th>
586 </tr>
587 <tr>
588 <td>VERSION.RELEASE</td>
589 <td>The version of the currently-executing Android system, in human-readable
590format. 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>
591 </tr>
592 <tr>
593 <td>VERSION.SDK</td>
594 <td>The version of the currently-executing Android system, in a format accessible
595to third-party application code. For Android ANDROID_VERSION, this field MUST have the
Unsuk Jung8bebb3e2015-09-29 22:10:23 -0700[diff] [blame]596integer value ANDROID_VERSION_INT.</td>
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]597 </tr>
598 <tr>
599 <td>VERSION.SDK_INT</td>
600 <td>The version of the currently-executing Android system, in a format accessible
601to third-party application code. For Android ANDROID_VERSION, this field MUST have the
Unsuk Jung8bebb3e2015-09-29 22:10:23 -0700[diff] [blame]602integer value ANDROID_VERSION_INT.</td>
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]603 </tr>
604 <tr>
605 <td>VERSION.INCREMENTAL</td>
606 <td>A value chosen by the device implementer designating the specific build of the
607currently-executing Android system, in human-readable format. This value MUST
608NOT be reused for different builds made available to end users. A typical use
609of this field is to indicate which build number or source-control change
610identifier was used to generate the build. There are no requirements on the
611specific format of this field, except that it MUST NOT be null or the empty
612string ("").</td>
613 </tr>
614 <tr>
615 <td>BOARD</td>
616 <td>A value chosen by the device implementer identifying the specific internal
617hardware used by the device, in human-readable format. A possible use of this
618field is to indicate the specific revision of the board powering the device.
619The value of this field MUST be encodable as 7-bit ASCII and match the regular
620expression &ldquo;^[a-zA-Z0-9_-]+$&rdquo;.</td>
621 </tr>
622 <tr>
623 <td>BRAND</td>
624 <td>A value reflecting the brand name associated with the device as known to the
625end users. MUST be in human-readable format and SHOULD represent the
626manufacturer of the device or the company brand under which the device is
627marketed. The value of this field MUST be encodable as 7-bit ASCII and match
628the regular expression &ldquo;^[a-zA-Z0-9_-]+$&rdquo;.</td>
629 </tr>
630 <tr>
631 <td>SUPPORTED_ABIS</td>
632 <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>
633 </tr>
634 <tr>
635 <td>SUPPORTED_32_BIT_ABIS</td>
636 <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>
637 </tr>
638 <tr>
639 <td>SUPPORTED_64_BIT_ABIS</td>
640 <td>The name of the second instruction set (CPU type + ABI convention) of native
641code. See <a href="#3_3_native_api_compatibility">section 3.3. Native API Compatibility</a>.</td>
642 </tr>
643 <tr>
644 <td>CPU_ABI</td>
645 <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>
646 </tr>
647 <tr>
648 <td>CPU_ABI2</td>
649 <td>The name of the second instruction set (CPU type + ABI convention) of native
650code. See <a href="#3_3_native_api_compatibility">section 3.3. Native API Compatibility</a>.</td>
651 </tr>
652 <tr>
653 <td>DEVICE</td>
654 <td>A value chosen by the device implementer containing the development name or
655code name identifying the configuration of the hardware features and industrial
656design of the device. The value of this field MUST be encodable as 7-bit ASCII
657and match the regular expression &ldquo;^[a-zA-Z0-9_-]+$&rdquo;.</td>
658 </tr>
659 <tr>
660 <td>FINGERPRINT</td>
661 <td>A string that uniquely identifies this build. It SHOULD be reasonably
662human-readable. It MUST follow this template:</p>
663
664<p class="small">$(BRAND)/$(PRODUCT)/$(DEVICE):$(VERSION.RELEASE)/$(ID)/$(VERSION.INCREMENTAL):$(TYPE)/$(TAGS)</p>
665
666<p>For example: acme/myproduct/mydevice:ANDROID_VERSION/LMYXX/3359:userdebug/test-keys</p>
667
668<p>The fingerprint MUST NOT include whitespace characters. If other fields
669included in the template above have whitespace characters, they MUST be
670replaced in the build fingerprint with another character, such as the
671underscore ("_") character. The value of this field MUST be encodable as 7-bit
672ASCII.</td>
673 </tr>
674 <tr>
675 <td>HARDWARE</td>
676 <td>The name of the hardware (from the kernel command line or /proc). It SHOULD be
677reasonably human-readable. The value of this field MUST be encodable as 7-bit
678ASCII and match the regular expression &ldquo;^[a-zA-Z0-9_-]+$&rdquo;. </td>
679 </tr>
680 <tr>
681 <td>HOST</td>
682 <td>A string that uniquely identifies the host the build was built on, in
683human-readable format. There are no requirements on the specific format of this
684field, except that it MUST NOT be null or the empty string ("").</td>
685 </tr>
686 <tr>
687 <td>ID</td>
688 <td>An identifier chosen by the device implementer to refer to a specific release,
689in human-readable format. This field can be the same as
690android.os.Build.VERSION.INCREMENTAL, but SHOULD be a value sufficiently
691meaningful for end users to distinguish between software builds. The value of
692this field MUST be encodable as 7-bit ASCII and match the regular expression &ldquo;^[a-zA-Z0-9._-]+$&rdquo;.</td>
693 </tr>
694 <tr>
695 <td>MANUFACTURER</td>
696 <td>The trade name of the Original Equipment Manufacturer (OEM) of the product.
697There are no requirements on the specific format of this field, except that it
698MUST NOT be null or the empty string ("").</td>
699 </tr>
700 <tr>
701 <td>MODEL</td>
702 <td>A value chosen by the device implementer containing the name of the device as
703known to the end user. This SHOULD be the same name under which the device is
704marketed and sold to end users. There are no requirements on the specific
705format of this field, except that it MUST NOT be null or the empty string ("").</td>
706 </tr>
707 <tr>
708 <td>PRODUCT</td>
709 <td>A value chosen by the device implementer containing the development name or
710code name of the specific product (SKU) that MUST be unique within the same
711brand. MUST be human-readable, but is not necessarily intended for view by end
712users. The value of this field MUST be encodable as 7-bit ASCII and match the
713regular expression &ldquo;^[a-zA-Z0-9_-]+$&rdquo;.</td>
714 </tr>
715 <tr>
716 <td>SERIAL</td>
Owain Davies4f8796e2015-09-24 14:01:26 +0100[diff] [blame]717 <td>A hardware serial number, which MUST be available and unique across
718devices with the same MODEL and MANUFACTURER. The value of this field MUST
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]719be encodable as 7-bit ASCII and match the regular expression &ldquo;^([a-zA-Z0-9]{6,20})$&rdquo;.</td>
720 </tr>
721 <tr>
722 <td>TAGS</td>
723 <td>A comma-separated list of tags chosen by the device implementer that further
724distinguishes the build. This field MUST have one of the values corresponding
725to the three typical Android platform signing configurations: release-keys,
726dev-keys, test-keys. </td>
727 </tr>
728 <tr>
729 <td>TIME</td>
730 <td>A value representing the timestamp of when the build occurred.</td>
731 </tr>
732 <tr>
733 <td>TYPE</td>
734 <td>A value chosen by the device implementer specifying the runtime configuration
735of the build. This field MUST have one of the values corresponding to the three
736typical Android runtime configurations: user, userdebug, or eng.</td>
737 </tr>
738 <tr>
739 <td>USER</td>
740 <td>A name or user ID of the user (or automated user) that generated the build.
741There are no requirements on the specific format of this field, except that it
742MUST NOT be null or the empty string ("").</td>
743 </tr>
744</table>
745
746
747<h3 id="3_2_3_intent_compatibility">3.2.3. Intent Compatibility</h3>
748
749
750<p>Device implementations MUST honor Android&rsquo;s loose-coupling intent system, as
751described in the sections below. By&ldquo;honored &rdquo; it is meant that the device
752implementer MUST provide an Android Activity or Service that specifies a
753matching intent filter that binds to and implements correct behavior for each
754specified intent pattern.</p>
755
756<h4 id="3_2_3_1_core_application_intents">3.2.3.1. Core Application Intents</h4>
757
758
759<p>Android intents allow application components to request functionality from
760other Android components. The Android upstream project includes a list of
761applications considered core Android applications, which implements several
762intent patterns to perform common actions. The core Android applications are:</p>
763
764<ul>
765 <li>Desk Clock</li>
766 <li>Browser</li>
767 <li>Calendar</li>
768 <li>Contacts</li>
769 <li>Gallery</li>
770 <li>GlobalSearch</li>
771 <li>Launcher</li>
772 <li>Music</li>
773 <li>Settings</li>
774</ul>
775
776<p>Device implementations SHOULD include the core Android applications as
777appropriate but MUST include a component implementing the same intent patterns
778defined by all the &ldquo;public&rdquo; Activity or Service components of these core
779Android applications. Note that Activity or Service components are considered
780&ldquo;public&rdquo; when the attribute android:exported is absent or has the value true.</p>
781
782<h4 id="3_2_3_2_intent_overrides">3.2.3.2. Intent Overrides</h4>
783
784
785<p>As Android is an extensible platform, device implementations MUST allow each
786intent 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
787implementation allows this by default; device implementers MUST NOT attach
788special privileges to system applications' use of these intent patterns, or
789prevent third-party applications from binding to and assuming control of these
790patterns. This prohibition specifically includes but is not limited to
791disabling the&ldquo;Chooser&rdquo; user interface that allows the user to select between
792multiple applications that all handle the same intent pattern.</p>
793
794<p>However, device implementations MAY provide default activities for specific URI
795patterns (eg. http://play.google.com) if the default activity provides a more
796specific filter for the data URI. For example, an intent filter specifying the
797data 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
798modify the default activity for intents.</p>
799
800<h4 id="3_2_3_3_intent_namespaces">3.2.3.3. Intent Namespaces</h4>
801
802
803<p>Device implementations MUST NOT include any Android component that honors any
804new intent or broadcast intent patterns using an ACTION, CATEGORY, or other key
805string in the android.* or com.android.* namespace. Device implementers MUST
806NOT include any Android components that honor any new intent or broadcast
807intent patterns using an ACTION, CATEGORY, or other key string in a package
808space belonging to another organization. Device implementers MUST NOT alter or
809extend 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
810and obviously associated with their own organization. This prohibition is
811analogous to that specified for Java language classes in <a href="#3_6_api_namespaces">section 3.6</a>.</p>
812
813<h4 id="3_2_3_4_broadcast_intents">3.2.3.4. Broadcast Intents</h4>
814
815
816<p>Third-party applications rely on the platform to broadcast certain intents to
817notify them of changes in the hardware or software environment.
818Android-compatible devices MUST broadcast the public broadcast intents in
819response to appropriate system events. Broadcast intents are described in the
820SDK documentation.</p>
821
822<h4 id="3_2_3_5_default_app_settings">3.2.3.5. Default App Settings</h4>
823
824
825<p>Android includes settings that provide users an easy way to select their
826default applications, for example for Home screen or SMS. Where it makes sense,
827device implementations MUST provide a similar settings menu and be compatible
828with the intent filter pattern and API methods described in the SDK
829documentation as below.</p>
830
831<p>Device implementations:</p>
832
833<ul>
834 <li>MUST honor the android.settings.HOME_SETTINGS intent to show a default app
835settings menu for Home Screen, if the device implementation reports
836android.software.home_screen [<a href="http://developer.android.com/reference/android/provider/Settings.html">Resources, 10]</a></li>
837 <li>MUST provide a settings menu that will call the
838android.provider.Telephony.ACTION_CHANGE_DEFAULT intent to show a dialog to
839change the default SMS application, if the device implementation reports
840android.hardware.telephony [<a href="http://developer.android.com/reference/android/provider/Telephony.Sms.Intents.html">Resources, 9</a>]</li>
841 <li>MUST honor the android.settings.NFC_PAYMENT_SETTINGS intent to show a default
842app settings menu for Tap and Pay, if the device implementation reports
843android.hardware.nfc.hce [<a href="http://developer.android.com/reference/android/provider/Settings.html">Resources, 10]</a></li>
844</ul>
845
846<h2 id="3_3_native_api_compatibility">3.3. Native API Compatibility</h2>
847
848
849<h3 id="3_3_1_application_binary_interfaces">3.3.1. Application Binary Interfaces</h3>
850
851
852<p>Managed Dalvik bytecode can call into native code provided in the application
853.apk file as an ELF .so file compiled for the appropriate device hardware
854architecture. As native code is highly dependent on the underlying processor
855technology, Android defines a number of Application Binary Interfaces (ABIs) in
856the Android NDK. Device implementations MUST be compatible with one or more
857defined ABIs, and MUST implement compatibility with the Android NDK, as below.</p>
858
859<p>If a device implementation includes support for an Android ABI, it:</p>
860
861<ul>
862 <li>MUST include support for code running in the managed environment to call into
863native code, using the standard Java Native Interface (JNI) semantics</li>
864 <li>MUST be source-compatible (i.e. header compatible) and binary-compatible (for
865the ABI) with each required library in the list below</li>
866 <li>MUST support the equivalent 32-bit ABI if any 64-bit ABI is supported</li>
867 <li>MUST accurately report the native Application Binary Interface (ABI) supported
868by the device, via the android.os.Build.SUPPORTED_ABIS,
869android.os.Build.SUPPORTED_32_BIT_ABIS, and
870android.os.Build.SUPPORTED_64_BIT_ABIS parameters, each a comma separated list
871of ABIs ordered from the most to the least preferred one</li>
Unsuk Jung06706432015-08-31 11:26:13 -0700[diff] [blame]872 <li>MUST report, via the above parameters, only those ABIs documented and
873described in the latest version of the Android NDK ABI Management documentation
874[<a href="https://developer.android.com/ndk/guides/abis.html">Resources, XX</a>],
875and MUST include support for the Advanced SIMD (a.k.a. NEON)
876[<a href="http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.ddi0388f/Beijfcja.html">Resources,XX</a>]
877extension
878 </li>
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]879 <li>SHOULD be built using the source code and header files available in the
880upstream Android Open Source Project</li>
881</ul>
882
883<p>The following native code APIs MUST be available to apps that include native
884code:</p>
885
886<ul>
887 <li>libc (C library)</li>
888 <li>libm (math library)</li>
889 <li>Minimal support for C++</li>
890 <li>JNI interface</li>
891 <li>liblog (Android logging)</li>
892 <li>libz (Zlib compression)</li>
893 <li>libdl (dynamic linker)</li>
894 <li>libGLESv1_CM.so (OpenGL ES 1.x)</li>
895 <li>libGLESv2.so (OpenGL ES 2.0)</li>
896 <li>libGLESv3.so (OpenGL ES 3.x)</li>
897 <li>libEGL.so (native OpenGL surface management)</li>
898 <li>libjnigraphics.so</li>
899 <li>libOpenSLES.so (OpenSL ES 1.0.1 audio support)</li>
900 <li>libOpenMAXAL.so (OpenMAX AL 1.0.1 support)</li>
901 <li>libandroid.so (native Android activity support)</li>
902 <li>libmediandk.so (native media APIs support)</li>
903 <li>Support for OpenGL, as described below</li>
904</ul>
905
906<p>Note that future releases of the Android NDK may introduce support for
907additional ABIs. If a device implementation is not compatible with an existing
908predefined ABI, it MUST NOT report support for any ABIs at all.</p>
909
910<p>Note that device implementations MUST include libGLESv3.so and it MUST symlink
911(symbolic link) to libGLESv2.so. in turn, MUST export all the OpenGL ES 3.1 and
912Android 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
913symbols must be present, only the corresponding functions for OpenGL ES
914versions and extensions actually supported by the device must be fully
915implemented.</p>
916
Unsuk Jung6f6ac762015-09-29 14:28:03 -0700[diff] [blame]917<p>Device implementations MUST NOT include a native library with the
918name libvulkan.so.</p>
919
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]920<p>Native code compatibility is challenging. For this reason, device implementers
Bert McMeen816a2422015-09-29 16:33:19 -0700[diff] [blame]921are <strong>STRONGLY RECOMMENDED</strong> to use the implementations of the libraries listed above from the upstream
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]922Android Open Source Project. </p>
923
924<h3 id="3_3_2_32-bit_arm_native_code_compatibility">
9253.3.2. 32-bit ARM Native Code Compatibility
926</h3>
927
928<p>The ARMv8 architecture deprecates several CPU operations, including some
929operations used in existing native code. On 64-bit ARM devices, the following
930deprecated operations MUST remain available to 32-bit native ARM code, either
931through native CPU support or through software emulation:</p>
932
933<ul>
934<li>SWP and SWPB instructions</li>
935<li>SETEND instruction</li>
936<li>CP15ISB, CP15DSB, and CP15DMB barrier operations</li>
937</ul>
938
939<p>Legacy versions of the Android NDK used /proc/cpuinfo to discover CPU features
940from 32-bit ARM native code. For compatibility with applications built using this
941NDK, devices MUST include the following lines in /proc/cpuinfo when it is read
942by 32-bit ARM applications:</p>
943
944<ul>
945<li>&quot;Features: &quot;, followed by a list of any optional ARMv7 CPU features
946supported by the device</li>
947<li>&quot;CPU architecture: &quot;, followed by an integer describing the device's
948highest supported ARM architecture (e.g., &quot;8&quot; for ARMv8 devices)</li>
949</ul>
950
951<p>These requirements only apply when /proc/cpuinfo is read by 32-bit ARM
952applications. Devices SHOULD not alter /proc/cpuinfo when read by 64-bit ARM or
953non-ARM applications.</p>
954
955<h2 id="3_4_web_compatibility">3.4. Web Compatibility</h2>
956
957
958<h3 id="3_4_1_webview_compatibility">3.4.1. WebView Compatibility</h3>
959
960<div class="note">
961<p>Android Watch devices MAY, but all other device implementations MUST provide
962a complete implementation of the android.webkit.Webview API.</p>
963</div>
964
965
966<p>The platform feature android.software.webview MUST be reported on any device
967that provides a complete implementation of the android.webkit.WebView API, and
968MUST NOT be reported on devices without a complete implementation of the API.
969The Android Open Source implementation uses code from the Chromium Project to
970implement 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
971rendering system, device implementers MUST use the specific upstream build of
972Chromium in the WebView implementation. Specifically:</p>
973
974<ul>
975 <li>Device android.webkit.WebView implementations MUST be based on the Chromium
976build from the upstream Android Open Source Project for Android ANDROID_VERSION. This build
977includes a specific set of functionality and security fixes for the WebView [<a href="http://www.chromium.org/">Resources, 13</a>].</li>
978 <li>The user agent string reported by the WebView MUST be in this format:
Unsuk Jung34d4dcb2015-09-28 15:41:27 -0700[diff] [blame]979<p>Mozilla/5.0 (Linux; Android $(VERSION); $(MODEL) Build/$(BUILD); wv)
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]980AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 $(CHROMIUM_VER) Mobile
981Safari/537.36</p>
982 <ul>
983 <li>The value of the $(VERSION) string MUST be the same as the value for
984android.os.Build.VERSION.RELEASE.</li>
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]985 <li>The value of the $(MODEL) string MUST be the same as the value for
986android.os.Build.MODEL.</li>
987 <li>The value of the $(BUILD) string MUST be the same as the value for
988android.os.Build.ID.</li>
989 <li>The value of the $(CHROMIUM_VER) string MUST be the version of Chromium in the
990upstream Android Open Source Project.</li>
991 <li>Device implementations MAY omit Mobile in the user agent string.</li>
992 </ul></li></ul>
993
994<p>The WebView component SHOULD include support for as many HTML5 features as
995possible and if it supports the feature SHOULD conform to the HTML5
996specification [<a href="http://html.spec.whatwg.org/multipage/">Resources, 14</a>].</p>
997
998<h3 id="3_4_2_browser_compatibility">3.4.2. Browser Compatibility</h3>
999
1000<div class="note">
1001<p>Android Television, Watch, and Android Automotive implementations MAY omit a
1002browser application, but MUST support the public intent patterns as described in
1003<a href="#3_2_3_1_core_application_intents">section 3.2.3.1</a>. All other types
1004of device implementations MUST include a standalone Browser application for
1005general user web browsing.</p>
1006</div>
1007
1008<p>The standalone Browser MAY be based on a browser technology other than WebKit.
1009However, even if an alternate Browser application is used, the
1010android.webkit.WebView component provided to third-party applications MUST be
1011based on WebKit, as described in <a href="#3_4_1_webview_compatibility">section 3.4.1</a>.</p>
1012
1013<p>Implementations MAY ship a custom user agent string in the standalone Browser
1014application.</p>
1015
1016<p>The standalone Browser application (whether based on the upstream WebKit
1017Browser application or a third-party replacement) SHOULD include support for as
1018much of HTML5 [<a href="http://html.spec.whatwg.org/multipage/">Resources, 14</a>] as possible. Minimally, device implementations MUST support each of these
1019APIs associated with HTML5:</p>
1020
1021<ul>
1022 <li>application cache/offline operation [<a href="http://www.w3.org/html/wg/drafts/html/master/browsers.html#offline">Resources, 15</a>]</li>
1023 <li>the &#60;video&#62; tag [<a href="http://www.w3.org/html/wg/drafts/html/master/semantics.html#video">Resources, 16</a>]</li>
1024 <li>geolocation [<a href="http://www.w3.org/TR/geolocation-API/">Resources, 17</a>]</li>
1025</ul>
1026
1027<p>Additionally, device implementations MUST support the HTML5/W3C webstorage API
1028[<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
1029IndexedDB over webstorage, IndexedDB is expected to become a required component
1030in a future version of Android.</p>
1031
1032<h2 id="3_5_api_behavioral_compatibility">3.5. API Behavioral Compatibility</h2>
1033
1034
1035<p>The behaviors of each of the API types (managed, soft, native, and web) must be
1036consistent with the preferred implementation of the upstream Android Open
1037Source Project [<a href="http://source.android.com/">Resources, 2</a>]. Some specific areas of compatibility are:</p>
1038
1039<ul>
1040 <li>Devices MUST NOT change the behavior or semantics of a standard intent.</li>
1041 <li>Devices MUST NOT alter the lifecycle or lifecycle semantics of a particular
1042type of system component (such as Service, Activity, ContentProvider, etc.).</li>
1043 <li>Devices MUST NOT change the semantics of a standard permission.</li>
1044</ul>
1045
1046<p>The above list is not comprehensive. The Compatibility Test Suite (CTS) tests
1047significant portions of the platform for behavioral compatibility, but not all.
1048It is the responsibility of the implementer to ensure behavioral compatibility
1049with the Android Open Source Project. For this reason, device implementers
1050SHOULD use the source code available via the Android Open Source Project where
1051possible, rather than re-implement significant parts of the system.</p>
1052
1053<h2 id="3_6_api_namespaces">3.6. API Namespaces</h2>
1054
1055
1056<p>Android follows the package and class namespace conventions defined by the Java
1057programming language. To ensure compatibility with third-party applications,
1058device implementers MUST NOT make any prohibited modifications (see below) to
1059these package namespaces:</p>
1060
1061<ul>
1062 <li>java.*</li>
1063 <li>javax.*</li>
1064 <li>sun.*</li>
1065 <li>android.*</li>
1066 <li>com.android.*</li>
1067</ul>
1068
1069<p><strong>Prohibited modifications include</strong>:</p>
1070
1071<ul>
1072 <li>Device implementations MUST NOT modify the publicly exposed APIs on the Android
1073platform by changing any method or class signatures, or by removing classes or
1074class fields.</li>
1075 <li>Device implementers MAY modify the underlying implementation of the APIs, but
1076such modifications MUST NOT impact the stated behavior and Java-language
1077signature of any publicly exposed APIs.</li>
1078 <li>Device implementers MUST NOT add any publicly exposed elements (such as classes
1079or interfaces, or fields or methods to existing classes or interfaces) to the
1080APIs above.</li>
1081</ul>
1082
1083<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,
1084device implementers MUST NOT expose new APIs or alter existing APIs in the
1085namespaces noted above. Device implementers MAY make internal-only
1086modifications, but those modifications MUST NOT be advertised or otherwise
1087exposed to developers.</p>
1088
1089<p>Device implementers MAY add custom APIs, but any such APIs MUST NOT be in a
1090namespace owned by or referring to another organization. For instance, device
1091implementers MUST NOT add APIs to the com.google.* or similar namespace: only
1092Google may do so. Similarly, Google MUST NOT add APIs to other companies'
1093namespaces. Additionally, if a device implementation includes custom APIs
1094outside the standard Android namespace, those APIs MUST be packaged in an
1095Android shared library so that only apps that explicitly use them (via the
Unsuk Jung2e62f9a2015-07-16 23:01:44 -0700[diff] [blame]1096lt;uses-librarygt; mechanism) are affected by the increased memory usage of such
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]1097APIs.</p>
1098
1099<p>If a device implementer proposes to improve one of the package namespaces above
1100(such as by adding useful new functionality to an existing API, or adding a new
1101API), 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
1102information on that site.</p>
1103
1104<p>Note that the restrictions above correspond to standard conventions for naming
1105APIs in the Java programming language; this section simply aims to reinforce
1106those conventions and make them binding through inclusion in this Compatibility
1107Definition.</p>
1108
1109<h2 id="3_7_runtime_compatibility">3.7. Runtime Compatibility</h2>
1110
1111
1112<p>Device implementations MUST support the full Dalvik Executable (DEX) format and
1113Dalvik 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
1114the Dalvik Executable Format, and the reference implementation&rsquo;s package
1115management system.</p>
1116
1117<p>Device implementations MUST configure Dalvik runtimes to allocate memory in
1118accordance with the upstream Android platform, and as specified by the
1119following table. (See <a href="#7_1_1_screen_configuration">section 7.1.1</a> for screen size and screen density definitions.)</p>
1120
1121<p>Note that memory values specified below are considered minimum values and
1122device implementations MAY allocate more memory per application.</p>
1123
1124<table>
1125 <tr>
1126 <th>Screen Layout</th>
1127 <th>Screen Density</th>
1128 <th>Minimum Application Memory</th>
1129 </tr>
1130 <tr>
1131 <td rowspan="10">small/normal</td>
1132 <td>120 dpi (ldpi)</td>
1133 <td rowspan="2">32MB</td>
1134 </tr>
1135 <tr>
1136 <td>160 dpi (mdpi)</td>
1137 </tr>
1138 <tr>
1139 <td>213 dpi (tvdpi)</td>
1140 <td rowspan="3">48MB</td>
1141 </tr>
1142 <tr>
1143 <td>240 dpi (hdpi)</td>
1144 </tr>
1145 <tr>
1146 <td>280 dpi (280dpi)</td>
1147 </tr>
1148 <tr>
1149 <td>320 dpi (xhdpi)</td>
1150 <td>80MB</td>
1151 </tr>
1152 <tr>
1153 <td>400 dpi (400dpi)</td>
1154 <td>96MB</td>
1155 </tr>
1156 <tr>
1157 <td>480 dpi (xxhdpi)</td>
1158 <td>128MB</td>
1159 </tr>
1160 <tr>
1161 <td>560 dpi (560dpi)</td>
1162 <td>192MB</td>
1163 </tr>
1164 <tr>
1165 <td>640 dpi (xxxhdpi)</td>
1166 <td>256MB</td>
1167 </tr>
1168 <tr>
1169 <td rowspan="10">large</td>
1170 <td>120 dpi (ldpi)</td>
1171 <td>32MB</td>
1172 </tr>
1173 <tr>
1174 <td>160 dpi (mdpi)</td>
1175 <td>48MB</td>
1176 </tr>
1177 <tr>
1178 <td>213 dpi (tvdpi)</td>
1179 <td rowspan="2">80MB</td>
1180 </tr>
1181 <tr>
1182 <td>240 dpi (hdpi)</td>
1183 </tr>
1184 <tr>
1185 <td>280 dpi (280dpi)</td>
1186 <td>96MB</td>
1187 </tr>
1188 <tr>
1189 <td>320 dpi (xhdpi)</td>
1190 <td>128MB</td>
1191 </tr>
1192 <tr>
1193 <td>400 dpi (400dpi)</td>
1194 <td>192MB</td>
1195 </tr>
1196 <tr>
1197 <td>480 dpi (xxhdpi)</td>
1198 <td>256MB</td>
1199 </tr>
1200 <tr>
1201 <td>560 dpi (560dpi)</td>
1202 <td>384MB</td>
1203 </tr>
1204 <tr>
1205 <td>640 dpi (xxxhdpi)</td>
1206 <td>512MB</td>
1207 </tr>
1208 <tr>
1209 <td rowspan="10">xlarge</td>
1210 <td>120 dpi (ldpi)</td>
1211 <td>48MB</td>
1212 </tr>
1213 <tr>
1214 <td>160 dpi (mdpi)</td>
1215 <td>80MB</td>
1216 </tr>
1217 <tr>
1218 <td>213 dpi (tvdpi)</td>
1219 <td rowspan="2">96MB</td>
1220 </tr>
1221 <tr>
1222 <td>240 dpi (hdpi)</td>
1223 </tr>
1224 <tr>
1225 <td>280 dpi (280dpi)</td>
1226 <td>144MB</td>
1227 </tr>
1228 <tr>
1229 <td>320 dpi (xhdpi)</td>
1230 <td>192MB</td>
1231 </tr>
1232 <tr>
1233 <td>400 dpi (400dpi)</td>
1234 <td>288MB</td>
1235 </tr>
1236 <tr>
1237 <td>480 dpi (xxhdpi)</td>
1238 <td>384MB</td>
1239 </tr>
1240 <tr>
1241 <td>560 dpi (560dpi)</td>
1242 <td>576MB</td>
1243 </tr>
1244 <tr>
1245 <td>640 dpi (xxxhdpi)</td>
1246 <td>768MB</td>
1247 </tr>
1248</table>
1249
1250
1251<h2 id="3_8_user_interface_compatibility">3.8. User Interface Compatibility</h2>
1252
1253
1254<h3 id="3_8_1_launcher_home_screen">3.8.1. Launcher (Home Screen)</h3>
1255
1256
1257<p>Android includes a launcher application (home screen) and support for
1258third-party applications to replace the device launcher (home screen). Device
1259implementations that allow third-party applications to replace the device home
1260screen MUST declare the platform feature android.software.home_screen.</p>
1261
1262<h3 id="3_8_2_widgets">3.8.2. Widgets</h3>
1263
1264<div class="note">
1265<p>Widgets are optional for all Android device implementations, but SHOULD be
1266supported on Android Handheld devices.</p>
1267</div>
1268
1269
1270<p>Android defines a component type and corresponding API and lifecycle that
1271allows 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
1272implementations. Device implementations that support embedding widgets on the
1273home screen MUST meet the following requirements and declare support for
1274platform feature android.software.app_widgets.</p>
1275
1276<ul>
1277 <li>Device launchers MUST include built-in support for AppWidgets, and expose user
1278interface affordances to add, configure, view, and remove AppWidgets directly
1279within the Launcher.</li>
1280 <li>Device implementations MUST be capable of rendering widgets that are 4 x 4 in
1281the standard grid size. See the App Widget Design Guidelines in the Android SDK
1282documentation [<a href="http://developer.android.com/guide/practices/ui_guidelines/widget_design.html">Resources, 21</a>] for details.</li>
1283 <li>Device implementations that include support for lock screen MAY support
1284application widgets on the lock screen.</li>
1285</ul>
1286
1287<h3 id="3_8_3_notifications">3.8.3. Notifications</h3>
1288
1289
1290<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>
1291
1292<p>Some APIs allow applications to perform notifications or attract attention
1293using hardware&#8212;specifically sound, vibration, and light. Device implementations
1294MUST support notifications that use hardware features, as described in the SDK
1295documentation, and to the extent possible with the device implementation
1296hardware. For instance, if a device implementation includes a vibrator, it MUST
1297correctly implement the vibration APIs. If a device implementation lacks
1298hardware, the corresponding APIs MUST be implemented as no-ops. This behavior
1299is further detailed in <a href="#7_hardware_compatibility">section 7</a>.</p>
1300
1301<p>Additionally, the implementation MUST correctly render all resources (icons, animation files
1302etc.) provided for in the APIs
1303[<a href="https://developer.android.com/guide/topics/resources/available-resources.html">Resources, 23</a>],
1304or in the Status/System Bar icon style guide
1305[<a href="http://developer.android.com/design/style/iconography.html">Resources, 24</a>],
1306which in the case of an Android Television device includes the possibility to not display the
1307notifications. Device implementers MAY provide an alternative user experience for
1308notifications than that provided by the reference Android Open Source
1309implementation; however, such alternative notification systems MUST support
1310existing notification resources, as above. </p>
1311
1312<p>Android includes support for various notifications, such as:</p>
1313
1314<ul>
1315 <li><strong>Rich notifications</strong>. Interactive Views for ongoing notifications.</li>
1316 <li><strong>Heads-up notifications</strong>. Interactive Views users can act on or dismiss without leaving the current app.</li>
1317 <li><strong>Lockscreen notifications</strong>. Notifications shown over a lock screen with granular control on visibility.</li>
1318</ul>
1319
1320<p>Android device implementations, when such notifications are made visible, MUST properly execute
1321Rich and Heads-up notifications and include the title/name, icon, text as documented in the Android
1322APIs <a href="https://developer.android.com/design/patterns/notifications.html">[Resources, 25]</a>.
1323</p>
1324
1325<p>Android includes Notification Listener Service APIs that allow apps (once
1326explicitly enabled by the user) to receive a copy of all notifications as they
1327are posted or updated. Device implementations MUST correctly and promptly send
1328notifications in their entirety to all such installed and user-enabled listener
1329services, including any and all metadata attached to the Notification object.</p>
1330
1331<h3 id="3_8_4_search">3.8.4. Search</h3>
1332
1333
1334<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
1335expose their application&rsquo;s data into the global system search. Generally
1336speaking, this functionality consists of a single, system-wide user interface
1337that allows users to enter queries, displays suggestions as users type, and
1338displays results. The Android APIs allow developers to reuse this interface to
1339provide search within their own apps, and allow developers to supply results to
1340the common global search user interface.</p>
1341
1342<p>Android device implementations SHOULD include global search, a single, shared,
1343system-wide search user interface capable of real-time suggestions in response
1344to user input. Device implementations SHOULD implement the APIs that allow
1345developers to reuse this user interface to provide search within their own
1346applications. Device implementations that implement the global search interface
1347MUST implement the APIs that allow third-party applications to add suggestions
1348to the search box when it is run in global search mode. If no third-party
1349applications are installed that make use of this functionality, the default
1350behavior SHOULD be to display web search engine results and suggestions.</p>
1351
1352<h3 id="3_8_5_toasts">3.8.5. Toasts</h3>
1353
1354
1355<p>Applications can use the &ldquo;Toast&rdquo; API to display short non-modal strings to the
1356end 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
1357some high-visibility manner.</p>
1358
1359<h3 id="3_8_6_themes">3.8.6. Themes</h3>
1360
1361
1362<p>Android provides &ldquo;themes&rdquo; as a mechanism for applications to apply styles
1363across an entire Activity or application.</p>
1364
1365<p>Android includes a &ldquo;Holo&rdquo; theme family as a set of defined styles for
1366application developers to use if they want to match the Holo theme look and
1367feel 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
1368exposed to applications [<a href="http://developer.android.com/reference/android/R.style.html">Resources, 29</a>].</p>
1369
1370<p>Android includes a &ldquo;Material&rdquo; theme family as a set of defined styles for
1371application developers to use if they want to match the design theme&rsquo;s look and
1372feel across the wide variety of different Android device types. Device
1373implementations MUST support the &ldquo;Material&rdquo; theme family and MUST NOT alter any
1374of 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>
1375
1376<p>Android also includes a &ldquo;Device Default&rdquo; theme family as a set of defined
1377styles for application developers to use if they want to match the look and
1378feel of the device theme as defined by the device implementer. Device
1379implementations MAY modify the Device Default theme attributes exposed to
1380applications [<a href="http://developer.android.com/reference/android/R.style.html">Resources, 29</a>].</p>
1381
Danielle Robertsbe0f08c2015-09-29 14:09:34 -0700[diff] [blame]1382<p>Android supports a variant theme with translucent system bars, which allows
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]1383application developers to fill the area behind the status and navigation bar
1384with their app content. To enable a consistent developer experience in this
1385configuration, it is important the status bar icon style is maintained across
1386different device implementations. Therefore, Android device implementations
1387MUST use white for system status icons (such as signal strength and battery
1388level) and notifications issued by the system, unless the icon is indicating a
Danielle Robertsbe0f08c2015-09-29 14:09:34 -0700[diff] [blame]1389problematic status or an app requests a light status bar using the
1390SYSTEM_UI_FLAG_LIGHT_STATUS_BAR flag. When an app requests a light status bar,
1391Android device implementations MUST change the color of the system status icons
1392to black [<a href="http://developer.android.com/reference/android/R.style.html">Resources, 29</a>].</p>
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]1393
1394<h3 id="3_8_7_live_wallpapers">3.8.7. Live Wallpapers</h3>
1395
1396
1397<p>Android defines a component type and corresponding API and lifecycle that
1398allows 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
1399input capabilities that display as a wallpaper, behind other applications.</p>
1400
1401<p>Hardware is considered capable of reliably running live wallpapers if it can
1402run all live wallpapers, with no limitations on functionality, at a reasonable
1403frame rate with no adverse effects on other applications. If limitations in the
1404hardware cause wallpapers and/or applications to crash, malfunction, consume
1405excessive CPU or battery power, or run at unacceptably low frame rates, the
1406hardware is considered incapable of running live wallpaper. As an example, some
1407live wallpapers may use an OpenGL 2.0 or 3.x context to render their content.
1408Live wallpaper will not run reliably on hardware that does not support multiple
1409OpenGL contexts because the live wallpaper use of an OpenGL context may
1410conflict with other applications that also use an OpenGL context.</p>
1411
1412<p>Device implementations capable of running live wallpapers reliably as described
1413above SHOULD implement live wallpapers, and when implemented MUST report the
1414platform feature flag android.software.live_wallpaper.</p>
1415
1416<h3 id="3_8_8_activity_switching">3.8.8. Activity Switching</h3>
1417
1418<div class="note">
1419<p>As the Recent function navigation key is OPTIONAL, the requirements to
1420implement the overview screen is OPTIONAL for Android Television devices and
1421Android Watch devices.</p>
1422</div>
1423
1424
1425<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
1426accessed activities and tasks using a thumbnail image of the application&rsquo;s
1427graphical state at the moment the user last left the application. Device
1428implementations 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>
1429
1430<ul>
1431 <li>MUST display affiliated recents as a group that moves together.</li>
1432 <li>MUST support at least up to 20 displayed activities.</li>
1433 <li>MUST at least display the title of 4 activities at a time.</li>
1434 <li>SHOULD display highlight color, icon, screen title in recents.</li>
1435 <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>
1436 <li>SHOULD display a closing affordance ("x") but MAY delay this until user
1437interacts with screens.</li>
1438</ul>
1439
Bert McMeen816a2422015-09-29 16:33:19 -0700[diff] [blame]1440<p>Device implementations are STRONGLY RECOMMENDED to use the upstream Android user
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]1441interface (or a similar thumbnail-based interface) for the overview screen.</p>
1442
1443<h3 id="3_8_9_input_management">3.8.9. Input Management</h3>
1444
1445
1446<p>Android includes support for Input Management and support for third-party input
1447method 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
1448the device MUST declare the platform feature android.software.input_methods and
1449support IME APIs as defined in the Android SDK documentation.</p>
1450
1451<p>Device implementations that declare the android.software.input_methods feature
1452MUST provide a user-accessible mechanism to add and configure third-party input
1453methods. Device implementations MUST display the settings interface in response
1454to the android.settings.INPUT_METHOD_SETTINGS intent.</p>
1455
1456<h3 id="3_8_10_lock_screen_media_control">3.8.10. Lock Screen Media Control</h3>
1457
1458
1459<p>The Remote Control Client API is deprecated from Android 5.0 in favor of the
1460Media Notification Template that allows media applications to integrate with
1461playback controls that are displayed on the lock screen [<a href="http://developer.android.com/reference/android/app/Notification.MediaStyle.html">Resources, 35</a>].
1462Device implementations that support a lock screen, unless an Android Automotive or Watch
1463implementation, MUST display the Lockscreen Notifications including the Media Notification
1464Template.</p>
1465
1466<h3 id="3_8_11_dreams">3.8.11. Dreams</h3>
1467
1468
1469<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
1470a power source is idle or docked in a desk dock. Android Watch devices MAY
1471implement Dreams, but other types of device implementations SHOULD include
1472support for Dreams and provide a settings option for users to configure Dreams
1473in response to the android.settings.DREAM_SETTINGS intent.</p>
1474
1475<h3 id="3_8_12_location">3.8.12. Location</h3>
1476
1477
1478<p>When a device has a hardware sensor (e.g. GPS) that is capable of providing the
1479location coordinates, location modes MUST be displayed in the Location menu
1480within Settings [<a href="http://developer.android.com/reference/android/provider/Settings.Secure.html#LOCATION_MODE">Resources, 37</a>].</p>
1481
1482<h3 id="3_8_13_unicode_and_font">3.8.13. Unicode and Font</h3>
1483
1484
1485<p>Android includes support for color emoji characters. When Android device
1486implementations include an IME, devices SHOULD provide an input method to the
1487user 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>
1488
1489<p>Android includes support for Roboto 2 font with different
1490weights&mdash;sans-serif-thin, sans-serif-light, sans-serif-medium, sans-serif-black,
1491sans-serif-condensed, sans-serif-condensed-light&mdash;which MUST all be included for
1492the languages available on the device and full Unicode 7.0 coverage of Latin,
1493Greek, and Cyrillic, including the Latin Extended A, B, C, and D ranges, and
1494all glyphs in the currency symbols block of Unicode 7.0.</p>
1495
1496<h2 id="3_9_device_administration">3.9. Device Administration</h2>
1497
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]1498<p>Android includes features that allow security-aware applications to perform
1499device administration functions at the system level, such as enforcing password
1500policies or performing remote wipe, through the Android Device Administration
1501API [<a href="http://developer.android.com/guide/topics/admin/device-admin.html">Resources, 39</a>].
1502Device implementations MUST provide an implementation of the DevicePolicyManager class
1503[<a href="http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html">Resources, 40</a>].
1504Device implementations that include support for PIN (numeric) or PASSWORD
1505(alphanumeric) based lock screens MUST support the full range of device
1506administration policies defined in the Android SDK documentation
1507[<a href="http://developer.android.com/guide/topics/admin/device-admin.html">Resources, 39</a>]
1508and report the platform feature android.software.device_admin.</p>
1509
Andy Dyer-smith3d24bbe2015-09-11 15:35:23 +0100[diff] [blame]1510<h3 id="3_9_1_device_provisioning">3.9.1 Device Provisioning</h3>
1511<h4 id="3_9_1_1_device_owner_provisioning">3.9.1.1 Device owner provisioning</h4>
1512<p>If a device implementation declares the android.software.device_admin feature,
1513the out of box setup flow MUST make it possible to enroll a Device Policy
1514Controller (DPC) application as the Device Owner app
1515[<a href="http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html#isDeviceOwnerApp(java.lang.String)">
1516Resources, XX</a>]. Device implementations MAY have a preinstalled application
1517performing device administration functions but this application MUST NOT be set
1518as the Device Owner app without explicit consent or action from the user or the
1519administrator of the device.</p>
1520
1521<p>The device owner provisioning process (the flow initiated by
1522android.app.action.PROVISION_MANAGED_DEVICE
1523[<a href="http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html#ACTION_PROVISION_MANAGED_DEVICE">
1524Resources, XX</a>]) user experience MUST align with the AOSP implementation</p>
1525
1526<p>If the device implementation reports android.hardware.nfc, it MUST have NFC
1527enabled, even during the out-of-box setup flow, in order to allow for NFC
1528provisioning of Device owners
1529<a href="https://source.android.com/devices/tech/admin/provision.html#device_owner_provisioning_via_nfc">[Resources, XX]</a>.
1530</p>
1531
1532<h4 id="3_9_1_2_managed_profile_provisioning">3.9.1.2 Managed profile provisioning</h4>
1533<p>If a device implementation declares the android.software.managed_users,
1534it MUST be possible to enroll a Device Policy Controller (DPC) application
1535as the owner of a new Managed Profile
1536[<a href="http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html#isProfileOwnerApp(java.lang.String)">
1537Resources, XX</a>]</p>
1538
1539<p>The managed profile provisioning process (the flow initiated by
1540android.app.action.PROVISION_MANAGED_PROFILE
1541[<a href="http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html#ACTION_PROVISION_MANAGED_PROFILE">
1542Resources, XX</a>]) user experience MUST align with the AOSP implementation
1543</p>
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]1544
1545<h2 id="3_10_accessibility">3.10. Accessibility</h2>
1546
1547
1548<p>Android provides an accessibility layer that helps users with disabilities to
1549navigate their devices more easily. In addition, Android provides platform APIs
1550that enable accessibility service implementations to receive callbacks for user
1551and system events and generate alternate feedback mechanisms, such as
1552text-to-speech, haptic feedback, and trackball/d-pad navigation [<a href="http://developer.android.com/reference/android/accessibilityservice/AccessibilityService.html">Resources, 42</a>].</p>
1553
1554<p>Device implementations include the following requirements:</p>
1555
1556<ul>
1557<li>Android Automotive implementations SHOULD provide an implementation of the
1558Android accessibility framework consistent with the default Android
1559implementation.</li>
1560<li>Device implementations (Android Automotive excluded) MUST provide an
1561implementation of the Android accessibility framework consistent with the
1562default Android implementation.</li>
1563<li>Device implementations (Android Automotive excluded) MUST support
1564third-party accessibility service implementations through the
1565android.accessibilityservice APIs
1566[<a href="http://developer.android.com/reference/android/view/accessibility/package-summary.html">Resources, 43</a>]</li>
1567<li>Device implementations (Android Automotive excluded) MUST generate
1568AccessibilityEvents and deliver these events to all registered
1569AccessibilityService implementations in a manner consistent with the default
1570Android implementation</li>
1571<li> Device implementations (Android Automotive and Android Watch devices with
1572no audio output excluded), MUST provide a user-accessible mechanism to enable
1573and disable accessibility services, and MUST display this interface in response
1574to the android.provider.Settings.ACTION_ACCESSIBILITY_SETTINGS intent.</li>
1575</ul>
1576
1577<p>Additionally, device implementations SHOULD provide an implementation of an
1578accessibility service on the device, and SHOULD provide a mechanism for users
1579to enable the accessibility service during device setup. An open source
1580implementation of an accessibility service is available from the Eyes Free
1581project [<a href="http://code.google.com/p/eyes-free/">Resources, 44</a>].</p>
1582
1583<h2 id="3_11_text-to-speech">3.11. Text-to-Speech</h2>
1584
1585
1586<p>Android includes APIs that allow applications to make use of text-to-speech
1587(TTS) services and allows service providers to provide implementations of TTS
1588services [<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
1589MUST meet these requirements related to the Android TTS framework. </p>
1590
1591<p>Android Automotive implementations:</p>
1592<ul>
1593<li>MUST support the Android TTS framework APIs.</li>
1594<li>MAY support installation of third-party TTS engines. If supported, partners
1595MUST provide a user-accessible interface that allows the user to select a TTS
1596engine for use at system level.</li>
1597</ul>
1598
1599<p>All other device implementations:</p>
1600
1601<ul>
1602 <li> MUST support the Android TTS framework APIs and SHOULD include a TTS engine
1603supporting the languages available on the device. Note that the upstream
1604Android open source software includes a full-featured TTS engine
1605implementation.
1606 <li> MUST support installation of third-party TTS engines
1607 <li> MUST provide a user-accessible interface that allows users to select a TTS
1608engine for use at the system level
1609</ul>
1610
1611<h2 id="3_12_tv_input_framework">3.12. TV Input Framework</h2>
1612
1613
1614<p>The Android Television Input Framework (TIF) simplifies the delivery of live
1615content to Android Television devices. TIF provides a standard API to create
1616input modules that control Android Television devices. Android Television
1617device implementations MUST support Television Input Framework [<a href="http://source.android.com/devices/tv/index.html">Resources, 46</a>].</p>
1618
1619<p>Device implementations that support TIF MUST declare the platform feature
1620android.software.live_tv.</p>
1621
1622<h1 id="4_application_packaging_compatibility">4. Application Packaging Compatibility</h1>
1623
1624
1625<p>Device implementations MUST install and run Android &ldquo;.apk&rdquo; files as generated
1626by 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>
1627
1628<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
1629files from installing and running correctly on other compatible devices.</p>
1630
1631<h1 id="5_multimedia_compatibility">5. Multimedia Compatibility</h1>
1632
1633
1634<h2 id="5_1_media_codecs">5.1. Media Codecs</h2>
1635
1636
1637<p>Device implementations MUST support the core media formats specified in the
1638Android 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
1639implementations MUST support the media formats, encoders, decoders, file types,
1640and container formats defined in the tables below and reported via MediaCodecList
1641[<a href="http://developer.android.com/reference/android/media/MediaCodecList.html">Resources,112</a>].
1642Device implementations MUST also be able to decode all profiles reported in its CamcorderProfile
1643[<a href="http://developer.android.com/reference/android/media/CamcorderProfile.html">Resources,
1644113</a>].
1645
1646All of these codecs are
1647provided as software implementations in the preferred Android implementation
1648from the Android Open Source Project.</p>
1649
1650<p>Please note that neither Google nor the Open Handset Alliance make any
1651representation that these codecs are free from third-party patents. Those
1652intending to use this source code in hardware or software products are advised
1653that implementations of this code, including in open source software or
1654shareware, may require patent licenses from the relevant patent holders.</p>
1655
1656<h3 id="5_1_1_audio_codecs">5.1.1. Audio Codecs</h3>
1657
1658<table>
1659 <tr>
1660 <th>Format/Codec</th>
1661 <th>Encoder</th>
1662 <th>Decoder</th>
1663 <th>Details</th>
1664 <th>Supported File Types/Container Formats</th>
1665 </tr>
1666 <tr>
1667 <td>MPEG-4 AAC Profile</p>
1668
1669<p>(AAC LC)</td>
1670 <td>REQUIRED<sup>1</sup></td>
1671 <td>REQUIRED</td>
Unsuk Jung2e62f9a2015-07-16 23:01:44 -0700[diff] [blame]1672 <td>Support for mono/stereo/5.0/5.1<sup>2</sup> content with standard sampling rates from 8 to
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]167348 kHz.</td>
1674 <td>
1675 <ul>
1676 <li class="table_list">3GPP (.3gp)</li>
1677 <li class="table_list">MPEG-4 (.mp4, .m4a)</li>
1678 <li class="table_list">ADTS raw AAC (.aac, decode in Android 3.1+, encode in Android 4.0+, ADIF not
1679supported)</li>
1680 <li class="table_list">MPEG-TS (.ts, not seekable, Android 3.0+)</li></ul></td>
1681 </tr>
1682 <tr>
1683 <td>MPEG-4 HE AAC Profile (AAC+)</td>
1684 <td>REQUIRED<sup>1</sup><br>(Android 4.1+)</td>
1685 <td>REQUIRED</td>
Unsuk Jung2e62f9a2015-07-16 23:01:44 -0700[diff] [blame]1686 <td>Support for mono/stereo/5.0/5.1<sup>2</sup> content with standard sampling rates from 16
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]1687to 48 kHz.</td>
1688 <td></td>
1689 </tr>
1690 <tr>
1691 <td>MPEG-4 HE AACv2</p>
1692
1693<p>Profile (enhanced AAC+)</td>
1694 <td> </td>
1695 <td>REQUIRED</td>
Unsuk Jung2e62f9a2015-07-16 23:01:44 -0700[diff] [blame]1696 <td>Support for mono/stereo/5.0/5.1<sup>2</sup> content with standard sampling rates from 16
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]1697to 48 kHz.</td>
1698 <td></td>
1699 </tr>
1700 <tr>
1701 <td>AAC ELD (enhanced low delay AAC)</td>
1702 <td>REQUIRED<sup>1</sup> </p>
1703
1704<p>(Android 4.1+)</td>
1705 <td>REQUIRED</p>
1706
1707<p>(Android 4.1+)</td>
1708 <td>Support for mono/stereo content with standard sampling rates from 16 to 48 kHz.</td>
1709 <td></td>
1710 </tr>
1711 <tr>
1712 <td>AMR-NB</td>
1713 <td>REQUIRED<sup>3</sup></td>
1714 <td>REQUIRED<sup>3</sup></td>
Glenn Kasten20cdbb72015-09-24 11:56:42 -0700[diff] [blame]1715 <td>4.75 to 12.2 kbps sampled @ 8 kHz</td>
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]1716 <td>3GPP (.3gp)</td>
1717 </tr>
1718 <tr>
1719 <td>AMR-WB</td>
1720 <td>REQUIRED<sup>3</sup></td>
1721 <td>REQUIRED<sup>3</sup></td>
Glenn Kasten20cdbb72015-09-24 11:56:42 -0700[diff] [blame]1722 <td>9 rates from 6.60 kbit/s to 23.85 kbit/s sampled @ 16 kHz</td>
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]1723 <td></td>
1724 </tr>
1725 <tr>
1726 <td>FLAC</td>
1727 <td></td>
1728 <td>REQUIRED <br>(Android 3.1+)</td>
1729 <td>Mono/Stereo (no multichannel). Sample rates up to 48 kHz (but up to 44.1 kHz is
Bert McMeen816a2422015-09-29 16:33:19 -0700[diff] [blame]1730RECOMMENDED on devices with 44.1 kHz output, as the 48 to 44.1 kHz downsampler
1731does not include a low-pass filter). 16-bit RECOMMENDED; no dither applied for
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]173224-bit.</td>
1733 <td>FLAC (.flac) only</td>
1734 </tr>
1735 <tr>
1736 <td>MP3</td>
1737 <td></td>
1738 <td>REQUIRED</td>
1739 <td>Mono/Stereo 8-320Kbps constant (CBR) or variable bitrate (VBR)</td>
1740 <td>MP3 (.mp3)</td>
1741 </tr>
1742 <tr>
1743 <td>MIDI</td>
1744 <td></td>
1745 <td>REQUIRED</td>
1746 <td>MIDI Type 0 and 1. DLS Version 1 and 2. XMF and Mobile XMF. Support for
1747ringtone formats RTTTL/RTX, OTA, and iMelody</td>
1748 <td><ul>
1749 <li class="table_list">Type 0 and 1 (.mid, .xmf, .mxmf)</li>
1750 <li class="table_list">RTTTL/RTX (.rtttl, .rtx)</li>
1751 <li class="table_list">OTA (.ota)</li>
1752 <li class="table_list">iMelody (.imy)</li></ul></td>
1753 </tr>
1754 <tr>
1755 <td>Vorbis</td>
1756 <td></td>
1757 <td>REQUIRED</td>
1758 <td></td>
1759 <td><ul>
1760 <li class="table_list">Ogg (.ogg)</li>
1761 <li class="table_list">Matroska (.mkv, Android 4.0+)</li></ul></td>
1762 </tr>
1763 <tr>
1764 <td>PCM/WAVE</td>
1765 <td>REQUIRED<sup>4</sup><br> (Android 4.1+)</td>
1766 <td>REQUIRED</td>
1767 <td>16-bit linear PCM (rates up to limit of hardware). Devices MUST support
1768sampling rates for raw PCM recording at 8000, 11025, 16000, and 44100 Hz
1769frequencies.</td>
1770 <td>WAVE (.wav)</td>
1771 </tr>
1772 <tr>
1773 <td>Opus</td>
1774 <td></td>
1775 <td>REQUIRED<br> (Android 5.0+)</td>
1776 <td></td>
1777 <td>Matroska (.mkv)</td>
1778 </tr>
1779</table>
1780
1781
1782<p class="table_footnote"> 1 Required for device implementations that define android.hardware.microphone
1783but optional for Android Watch device implementations.</p>
1784
1785<p class="table_footnote">2 Only downmix of 5.0/5.1 content is required; recording or rendering more than
17862 channels is optional.</p>
1787
1788<p class="table_footnote">3 Required for Android Handheld device implementations. </p>
1789
1790<p class="table_footnote">4 Required for device implementations that define android.hardware.microphone,
1791including Android Watch device implementations.</p>
1792
1793<h3 id="5_1_2_image_codecs">5.1.2. Image Codecs</h3>
1794
1795<table>
1796 <tr>
1797 <th>Format/Codec</th>
1798 <th>Encoder</th>
1799 <th>Decoder</th>
1800 <th>Details</th>
1801 <th>Supported File Types/Container Formats</th>
1802 </tr>
1803 <tr>
1804 <td>JPEG</td>
1805 <td>REQUIRED</td>
1806 <td>REQUIRED</td>
1807 <td>Base+progressive</td>
1808 <td>JPEG (.jpg)</td>
1809 </tr>
1810 <tr>
1811 <td>GIF</td>
1812 <td></td>
1813 <td>REQUIRED</td>
1814 <td></td>
1815 <td>GIF (.gif)</td>
1816 </tr>
1817 <tr>
1818 <td>PNG</td>
1819 <td>REQUIRED</td>
1820 <td>REQUIRED</td>
1821 <td></td>
1822 <td>PNG (.png)</td>
1823 </tr>
1824 <tr>
1825 <td>BMP</td>
1826 <td></td>
1827 <td>REQUIRED</td>
1828 <td></td>
1829 <td>BMP (.bmp)</td>
1830 </tr>
1831 <tr>
1832 <td>WebP</td>
1833 <td>REQUIRED</td>
1834 <td>REQUIRED</td>
1835 <td></td>
1836 <td>WebP (.webp)</td>
1837 </tr>
1838</table>
1839
1840
1841<h3 id="5_1_3_video_codecs">5.1.3. Video Codecs</h3>
1842
1843<p>Video codecs are optional for Android Watch device implementations.</p>
1844
1845<table>
1846 <tr>
1847 <th>Format/Codec</th>
1848 <th>Encoder</th>
1849 <th>Decoder</th>
1850 <th>Details</th>
1851 <th>Supported File Types/<br>Container Formats</th>
1852 </tr>
1853 <tr>
1854 <td>H.263</td>
1855 <td>REQUIRED<sup>1</sup></td>
1856 <td>REQUIRED<sup>2</sup></td>
1857 <td></td>
1858 <td><ul>
1859 <li class="table_list">3GPP (.3gp)</li>
1860 <li class="table_list">MPEG-4 (.mp4)</li></ul></td>
1861 </tr>
1862 <tr>
1863 <td>H.264 AVC</td>
1864 <td>REQUIRED<sup>2</sup></td>
1865 <td>REQUIRED<sup>2</sup></td>
1866 <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>
1867 <td><ul>
1868 <li class="table_list">3GPP (.3gp)</li>
1869 <li class="table_list">MPEG-4 (.mp4)</li>
1870 <li class="table_list">MPEG-TS (.ts, AAC audio only, not seekable, Android 3.0+)</li></ul></td>
1871 </tr>
1872 <tr>
1873 <td>H.265 HEVC</td>
1874 <td></td>
1875 <td>REQUIRED<sup>5</sup></td>
1876 <td>See <a href="#5_3_video_decoding">section 5.3</a> for details</td>
1877 <td>MPEG-4 (.mp4)</td>
1878 </tr>
1879 <tr>
1880 <td>MPEG-4 SP</td>
1881 <td></td>
1882 <td>REQUIRED<sup>2</sup></td>
1883 <td></td>
1884 <td>3GPP (.3gp)</td>
1885 </tr>
1886 <tr>
Unsuk Jung2e62f9a2015-07-16 23:01:44 -0700[diff] [blame]1887 <td>VP8<sup>3</sup></td>
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]1888 <td>REQUIRED<sup>2</sup></p>
1889
1890<p>(Android 4.3+)</td>
1891 <td>REQUIRED<sup>2</sup></p>
1892
1893<p>(Android 2.3.3+)</td>
1894 <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>
1895 <td><ul>
1896 <li class="table_list">WebM (.webm) [<a href="http://www.webmproject.org/">Resources, 110</a></li>
Unsuk Jung2e62f9a2015-07-16 23:01:44 -0700[diff] [blame]1897 <li class="table_list">Matroska (.mkv, Android 4.0+)<sup>4</sup></li></ul></td>
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]1898 </tr>
1899 <tr>
1900 <td>VP9</td>
1901 <td></td>
1902 <td>REQUIRED<sup>2</sup><br> (Android 4.4+)</td>
1903 <td>See <a href="#5_3_video_decoding">section 5.3</a> for details</td>
1904 <td><ul>
1905 <li class="table_list">WebM (.webm) [<a href="http://www.webmproject.org/">Resources, 110</a>]</li>
Unsuk Jung2e62f9a2015-07-16 23:01:44 -0700[diff] [blame]1906 <li class="table_list">Matroska (.mkv, Android 4.0+)<sup>4</sup></li></ul></td>
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]1907 </tr>
1908</table>
1909
1910
1911<p class="table_footnote">1 Required for device implementations that include camera hardware and define
1912android.hardware.camera or android.hardware.camera.front.</p>
1913
1914<p class="table_footnote">2 Required for device implementations except Android Watch devices. </p>
1915
1916<p class="table_footnote">3 For acceptable quality of web video streaming and video-conference services,
1917device implementations SHOULD use a hardware VP8 codec that meets the
1918requirements in [<a href="http://www.webmproject.org/hardware/rtc-coding-requirements/">Resources, 51</a>].</p>
1919
1920<p class="table_footnote">4 Device implementations SHOULD support writing Matroska WebM files.</p>
1921
Bert McMeen816a2422015-09-29 16:33:19 -0700[diff] [blame]1922<p class="table_footnote">5 STRONGLY RECOMMENDED for Android Automotive, optional for Android Watch, and required for all other device types.</p>
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]1923
1924<h2 id="5_2_video_encoding">5.2. Video Encoding</h2>
1925
1926<div class="note">
1927<p>Video codecs are optional for Android Watch device implementations.</p>
1928</div>
1929
Unsuk Jung1def5ae2015-09-29 14:53:42 -0700[diff] [blame]1930<p>Android device implementations with H.263 encoders, MUST support Baseline Profile Level 45.</p>
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]1931
1932<p>Android device implementations with H.264 codec support, MUST support Baseline
1933Profile Level 3 and the following SD (Standard Definition) video encoding
1934profiles and SHOULD support Main Profile Level 4 and the following HD (High
1935Definition) video encoding profiles. Android Television devices are STRONGLY
1936RECOMMENDED to encode HD 1080p video at 30 fps.</p>
1937<table>
1938 <tr>
1939 <th></th>
1940 <th>SD (Low quality)</th>
1941 <th>SD (High quality)</th>
1942 <th>HD 720p1</th>
1943 <th>HD 1080p1</th>
1944 </tr>
1945 <tr>
1946 <th>Video resolution</th>
1947 <td>320 x 240 px</td>
1948 <td>720 x 480 px</td>
1949 <td>1280 x 720 px</td>
1950 <td>1920 x 1080 px</td>
1951 </tr>
1952 <tr>
1953 <th>Video frame rate</th>
1954 <td>20 fps</td>
1955 <td>30 fps</td>
1956 <td>30 fps</td>
1957 <td>30 fps</td>
1958 </tr>
1959 <tr>
1960 <th>Video bitrate</th>
1961 <td>384 Kbps</td>
1962 <td>2 Mbps</td>
1963 <td>4 Mbps</td>
1964 <td>10 Mbps</td>
1965 </tr>
1966</table>
1967
1968
1969<p class="table_footnote">1 When supported by hardware, but STRONGLY RECOMMENDED for Android Television
1970devices.</p>
1971
1972<p>Android device implementations with VP8 codec support MUST support the SD video
1973encoding profiles and SHOULD support the following HD (High Definition) video
1974encoding profiles.</p>
1975<table>
1976 <tr>
1977 <th></th>
1978 <th>SD (Low quality)</th>
1979 <th>SD (High quality)</th>
1980 <th>HD 720p1</th>
1981 <th>HD 1080p1</th>
1982 </tr>
1983 <tr>
1984 <th>Video resolution</th>
1985 <td>320 x 180 px</td>
1986 <td>640 x 360 px</td>
1987 <td>1280 x 720 px</td>
1988 <td>1920 x 1080 px</td>
1989 </tr>
1990 <tr>
1991 <th>Video frame rate</th>
1992 <td>30 fps</td>
1993 <td>30 fps</td>
1994 <td>30 fps</td>
1995 <td>30 fps</td>
1996 </tr>
1997 <tr>
1998 <th>Video bitrate</th>
1999 <td>800 Kbps </td>
2000 <td>2 Mbps</td>
2001 <td>4 Mbps</td>
2002 <td>10 Mbps</td>
2003 </tr>
2004</table>
2005
2006<p class="table_footnote">1 When supported by hardware.</p>
2007
2008<h2 id="5_3_video_decoding">5.3. Video Decoding</h2>
2009
2010<div class="note">
2011<p>Video codecs are optional for Android Watch device implementations.</p>
2012</div>
2013
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]2014<p>Device implementations MUST support dynamic video resolution switching within
Unsuk Jung2e62f9a2015-07-16 23:01:44 -0700[diff] [blame]2015the same stream for all VP8, VP9, H.264, and H.265 codecs exposed through the
2016standard Android APIs.</p>
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]2017
Unsuk Jung1def5ae2015-09-29 14:53:42 -0700[diff] [blame]2018<p>Android device implementations with H.263 decoders, MUST support Baseline
2019Profile Level 30.</p>
2020
2021<p>Android device implementations with MPEG-4 decoders, MUST support Simple
2022Profile Level 3.</p>
2023
2024<p>Android device implementations with H.264 decoders, MUST support Main Profile
2025Level 3 and the following SD video decoding profiles and SHOULD support the
2026HD decoding profiles. Android Television devices MUST support High Profile
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]2027Level 4.2 and the HD 1080p decoding profile.</p>
2028<table>
2029 <tr>
2030 <th></th>
2031 <th>SD (Low quality)</th>
2032 <th>SD (High quality)</th>
2033 <th>HD 720p1</th>
2034 <th>HD 1080p1</th>
2035 </tr>
2036 <tr>
2037 <th>Video resolution</th>
2038 <td>320 x 240 px</td>
2039 <td>720 x 480 px</td>
2040 <td>1280 x 720 px</td>
2041 <td>1920 x 1080 px</td>
2042 </tr>
2043 <tr>
2044 <th>Video frame rate</th>
2045 <td>30 fps</td>
2046 <td>30 fps</td>
2047 <td>30 fps / 60 fps2</td>
2048 <td>30 fps / 60 fps2</td>
2049 </tr>
2050 <tr>
2051 <th>Video bitrate</th>
2052 <td>800 Kbps </td>
2053 <td>2 Mbps</td>
2054 <td>8 Mbps</td>
2055 <td>20 Mbps</td>
2056 </tr>
2057</table>
2058
2059
2060<p class="table_footnote">1 Required for Android Television device implementations, but for other device
2061types only when supported by hardware.</p>
2062
2063<p class="table_footnote">2 Required for Android Television device implementations.</p>
2064
2065<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
2066decoding profiles. Android Television devices MUST support the HD 1080p
2067decoding profile. </p>
2068<table>
2069 <tr>
2070 <th></th>
2071 <th>SD (Low quality)</th>
2072 <th>SD (High quality)</th>
2073 <th>HD 720p1</th>
2074 <th>HD 1080p1</th>
2075 </tr>
2076 <tr>
2077 <th>Video resolution</th>
2078 <td>320 x 180 px</td>
2079 <td>640 x 360 px</td>
2080 <td>1280 x 720 px</td>
2081 <td>1920 x 1080 px</td>
2082 </tr>
2083 <tr>
2084 <th>Video frame rate</th>
2085 <td>30 fps</td>
2086 <td>30 fps</td>
2087 <td>30 fps / 60 fps2</td>
2088 <td>30 / 60 fps2</td>
2089 </tr>
2090 <tr>
2091 <th>Video bitrate</th>
2092 <td>800 Kbps </td>
2093 <td>2 Mbps</td>
2094 <td>8 Mbps</td>
2095 <td>20 Mbps</td>
2096 </tr>
2097</table>
2098
2099
2100<p class="table_footnote">1 Required for Android Television device implementations, but for other type of
2101devices only when supported by hardware.</p>
2102
2103<p class="table_footnote">2 Required for Android Television device implementations.</p>
2104
2105<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
2106HD decoding profiles. Android Television devices are STRONGLY RECOMMENDED to
2107support the HD 1080p decoding profile and SHOULD support the UHD decoding
2108profile. When the UHD video decoding profile is supported, it MUST support 8
2109bit color depth.</p>
2110<table>
2111 <tr>
2112 <th></th>
2113 <th>SD (Low quality)</th>
2114 <th>SD (High quality)</th>
2115 <th>HD 720p 1</th>
2116 <th>HD 1080p 2</th>
2117 <th>UHD 2</th>
2118 </tr>
2119 <tr>
2120 <th>Video resolution</th>
2121 <td>320 x 180 px</td>
2122 <td>640 x 360 px</td>
2123 <td>1280 x 720 px</td>
2124 <td>1920 x 1080 px</td>
2125 <td>3840 x 2160 px</td>
2126 </tr>
2127 <tr>
2128 <th>Video frame rate</th>
2129 <td>30 fps</td>
2130 <td>30 fps</td>
2131 <td>30 fps</td>
2132 <td>30 fps</td>
2133 <td>30 fps</td>
2134 </tr>
2135 <tr>
2136 <th>Video bitrate</th>
2137 <td>600 Kbps </td>
2138 <td>1.6 Mbps</td>
2139 <td>4 Mbps</td>
2140 <td>10 Mbps</td>
2141 <td>20 Mbps</td>
2142 </tr>
2143</table>
2144
2145
2146<p class="table_footnote">1 Required for Android Television device implementations, but for other type of
2147devices only when supported by hardware.</p>
2148
2149<p class="table_footnote">2 STRONGLY RECOMMENDED for Android Television device implementations when
2150supported by hardware.</p>
2151
2152<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
2153decoding profiles and SHOULD support the HD decoding profiles. Android
2154Television devices MUST support the Main Profile Level 4.1 Main tier and the HD
21551080p decoding profile and SHOULD support Main10 Level 5 Main Tier profile and
2156the UHD decoding profile.</p>
2157<table>
2158 <tr>
2159 <th></th>
2160 <th>SD (Low quality)</th>
2161 <th>SD (High quality)</th>
2162 <th>HD 720p </strong>1 </td>
2163 <th>HD 1080p </strong>1 </td>
2164 <th>UHD </strong>2</td>
2165 </tr>
2166 <tr>
2167 <th>Video resolution</th>
2168 <td>352 x 288 px</td>
2169 <td>640 x 360 px</td>
2170 <td>1280 x 720 px</td>
2171 <td>1920 x 1080 px</td>
2172 <td>3840 x 2160 px</td>
2173 </tr>
2174 <tr>
2175 <th>Video frame rate</th>
2176 <td>30 fps</td>
2177 <td>30 fps</td>
2178 <td>30 fps</td>
2179 <td>30 fps</td>
2180 <td>30 fps</td>
2181 </tr>
2182 <tr>
2183 <th>Video bitrate</th>
2184 <td>600 Kbps </td>
2185 <td>1.6 Mbps</td>
2186 <td>4 Mbps</td>
2187 <td>10 Mbps</td>
2188 <td>20 Mbps</td>
2189 </tr>
2190</table>
2191
2192
2193<p class="table_footnote">1 Required for Android Television device implementation, but for other type of
2194devices only when supported by hardware.</p>
2195
2196<p class="table_footnote">2 Required for Android Television device implementations when supported by
2197hardware.</p>
2198
2199<h2 id="5_4_audio_recording">5.4. Audio Recording</h2>
2200
2201
2202<p>While some of the requirements outlined in this section are stated as SHOULD
2203since Android 4.3, the Compatibility Definition for a future version is planned
Glenn Kasten20cdbb72015-09-24 11:56:42 -0700[diff] [blame]2204to change these to MUST. Existing and new Android devices are <strong>STRONGLY ENCOURAGED</strong>
2205to meet these requirements, or they will not be able to attain Android compatibility when upgraded
2206to the future version.</p>
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]2207
2208<h3 id="5_4_1_raw_audio_capture">5.4.1. Raw Audio Capture</h3>
2209
2210
2211<p>Device implementations that declare android.hardware.microphone MUST allow
2212capture of raw audio content with the following characteristics:</p>
2213
2214<ul>
2215 <li><strong>Format</strong>: Linear PCM, 16-bit
2216 <li><strong>Sampling rates</strong>: 8000, 11025, 16000, 44100
2217 <li><strong>Channels</strong>: Mono
2218</ul>
2219
Glenn Kasten20cdbb72015-09-24 11:56:42 -0700[diff] [blame]2220<p>The capture for the above sample rates MUST be done without up-sampling, and
2221any down-sampling MUST include an appropriate anti-aliasing filter.</p>
2222
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]2223<p>Device implementations that declare android.hardware.microphone SHOULD allow
2224capture of raw audio content with the following characteristics:</p>
2225
2226<ul>
2227 <li><strong>Format</strong>: Linear PCM, 16-bit
2228 <li><strong>Sampling rates</strong>: 22050, 48000
2229 <li><strong>Channels</strong>: Stereo
2230</ul>
2231
Glenn Kasten20cdbb72015-09-24 11:56:42 -0700[diff] [blame]2232<p>If capture for the above sample rates is supported,
2233then the capture MUST be done without up-sampling at any ratio higher than 16000:22050
2234or 44100:48000.
2235Any up-sampling or down-sampling MUST include an appropriate anti-aliasing filter.</p>
2236
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]2237<h3 id="5_4_2_capture_for_voice_recognition">5.4.2. Capture for Voice Recognition</h3>
2238
2239
2240<p>In addition to the above recording specifications, when an application has
2241started recording an audio stream using the
2242android.media.MediaRecorder.AudioSource.VOICE_RECOGNITION audio source:</p>
2243
2244<ul>
2245 <li>The device SHOULD exhibit approximately flat amplitude versus frequency
2246characteristics: specifically, ±3 dB, from 100 Hz to 4000 Hz.
2247 <li>Audio input sensitivity SHOULD be set such that a 90 dB sound power level (SPL)
2248source at 1000 Hz yields RMS of 2500 for 16-bit samples.
2249 <li>PCM amplitude levels SHOULD linearly track input SPL changes over at least a 30
2250dB range from -18 dB to +12 dB re 90 dB SPL at the microphone.
Glenn Kasten20cdbb72015-09-24 11:56:42 -0700[diff] [blame]2251 <li>Total harmonic distortion SHOULD be less than 1% for 1 kHz at 90 dB SPL input
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]2252level at the microphone.
2253 <li>Noise reduction processing, if present, MUST be disabled.
2254 <li>Automatic gain control, if present, MUST be disabled
2255</ul>
2256
2257<p>If the platform supports noise suppression technologies tuned for speech
2258recognition, the effect MUST be controllable from the
2259android.media.audiofx.NoiseSuppressor API. Moreover, the UUID field for the
2260noise suppressor&rsquo;s effect descriptor MUST uniquely identify each implementation
2261of the noise suppression technology.</p>
2262
2263<h3 id="5_4_3_capture_for_rerouting_of_playback">5.4.3. Capture for Rerouting of Playback</h3>
2264
2265
2266<p>The android.media.MediaRecorder.AudioSource class includes the REMOTE_SUBMIX
2267audio source. Devices that declare android.hardware.audio.output MUST properly
2268implement the REMOTE_SUBMIX audio source so that when an application uses the
2269android.media.AudioRecord API to record from this audio source, it can capture
2270a mix of all audio streams except for the following:</p>
2271
2272<ul>
2273 <li>STREAM_RING
2274 <li>STREAM_ALARM
2275 <li>STREAM_NOTIFICATION
2276</ul>
2277
2278<h2 id="5_5_audio_playback">5.5. Audio Playback</h2>
2279
2280
2281<p>Device implementations that declare android.hardware.audio.output MUST conform
2282to the requirements in this section.</p>
2283
2284<h3 id="5_5_1_raw_audio_playback">5.5.1. Raw Audio Playback</h3>
2285
2286
2287<p>The device MUST allow playback of raw audio content with the following
2288characteristics:</p>
2289
2290<ul>
2291 <li><strong>Format</strong>: Linear PCM, 16-bit</li>
2292 <li><strong>Sampling rates</strong>: 8000, 11025, 16000, 22050, 32000, 44100</li>
2293 <li><strong>Channels</strong>: Mono, Stereo</li>
2294</ul>
2295
2296<p>The device SHOULD allow playback of raw audio content with the following
2297characteristics:</p>
2298
2299<ul>
2300 <li><strong>Sampling rates</strong>: 24000, 48000</li>
2301</ul>
2302
2303<h3 id="5_5_2_audio_effects">5.5.2. Audio Effects</h3>
2304
2305
2306<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
2307android.hardware.audio.output:</p>
2308
2309<ul>
2310 <li>MUST support the EFFECT_TYPE_EQUALIZER and EFFECT_TYPE_LOUDNESS_ENHANCER
2311implementations controllable through the AudioEffect subclasses Equalizer,
2312LoudnessEnhancer.</li>
2313 <li>MUST support the visualizer API implementation, controllable through the
2314Visualizer class.</li>
2315 <li>SHOULD support the EFFECT_TYPE_BASS_BOOST, EFFECT_TYPE_ENV_REVERB,
2316EFFECT_TYPE_PRESET_REVERB, and EFFECT_TYPE_VIRTUALIZER implementations
2317controllable through the AudioEffect sub-classes BassBoost,
2318EnvironmentalReverb, PresetReverb, and Virtualizer.</li>
2319</ul>
2320
2321<h3 id="5_5_3_audio_output_volume">5.5.3. Audio Output Volume</h3>
2322
2323
2324<p>Android Television device implementations MUST include support for system
2325Master Volume and digital audio output volume attenuation on supported outputs,
2326except for compressed audio passthrough output (where no audio decoding is done
2327on the device).</p>
2328
2329<h2 id="5_6_audio_latency">5.6. Audio Latency</h2>
2330
2331
2332<p>Audio latency is the time delay as an audio signal passes through a system.
2333Many classes of applications rely on short latencies, to achieve real-time
2334sound effects.</p>
2335
2336<p>For the purposes of this section, use the following definitions:</p>
2337
2338<ul>
2339 <li><strong>output latency</strong>. The interval between when an application writes a frame of PCM-coded data and
2340when the corresponding sound can be heard by an external listener or observed
2341by a transducer.</li>
2342 <li><strong>cold output latency</strong>. The output latency for the first frame, when the audio output system has been
2343idle and powered down prior to the request.</li>
2344 <li><strong>continuous output latency</strong>. The output latency for subsequent frames, after the device is playing audio.</li>
2345 <li><strong>input latency</strong>. The interval between when an external sound is presented to the device and
2346when an application reads the corresponding frame of PCM-coded data.</li>
2347 <li><strong>cold input latency</strong>. The sum of lost input time and the input latency for the first frame, when the
2348audio input system has been idle and powered down prior to the request.</li>
2349 <li><strong>continuous input latency</strong>. The input latency for subsequent frames, while the device is capturing audio.</li>
2350 <li><strong>cold output jitter</strong>. The variance among separate measurements of cold output latency values.</li>
2351 <li><strong>cold input jitter</strong>. The variance among separate measurements of cold input latency values.</li>
Glenn Kasten78eccbd2015-08-12 10:18:22 -0700[diff] [blame]2352 <li><strong>continuous round-trip latency</strong>. The sum of continuous input latency plus continuous output latency plus
2353 one buffer period.
2354 The buffer period term allows processing time for the app and for the app to
2355 mitigate phase difference between input and output streams.
2356 </li>
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]2357 <li><strong>OpenSL ES PCM buffer queue API</strong>. The set of PCM-related OpenSL ES APIs within Android NDK; see
2358NDK_root/docs/opensles/index.html.</li>
2359</ul>
2360
Bert McMeen816a2422015-09-29 16:33:19 -0700[diff] [blame]2361<p>Device implementations that declare android.hardware.audio.output are STRONGLY RECOMMENDED to meet
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]2362or exceed these audio output requirements:</p>
2363
2364<ul>
2365 <li>cold output latency of 100 milliseconds or less</li>
2366 <li>continuous output latency of 45 milliseconds or less</li>
2367 <li>minimize the cold output jitter</li>
2368</ul>
2369
2370<p>If a device implementation meets the requirements of this section after any
2371initial calibration when using the OpenSL ES PCM buffer queue API, for
2372continuous output latency and cold output latency over at least one supported
2373audio output device, it MAY report support for low-latency audio, by reporting
2374the feature android.hardware.audio.low_latency via the
2375android.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
2376MUST NOT report support for low-latency audio.</p>
2377
Bert McMeen816a2422015-09-29 16:33:19 -0700[diff] [blame]2378<p>Device implementations that include android.hardware.microphone are STRONGLY RECOMMENDED to meet
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]2379these input audio requirements:</p>
2380
2381<ul>
2382 <li>cold input latency of 100 milliseconds or less</li>
2383 <li>continuous input latency of 30 milliseconds or less</li>
2384 <li>continuous round-trip latency of 50 milliseconds or less</li>
2385 <li>minimize the cold input jitter</li>
2386</ul>
2387
2388<h2 id="5_7_network_protocols">5.7. Network Protocols</h2>
2389
2390
2391<p>Devices MUST support the media network protocols for audio and video playback
2392as 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>
2393
2394<ul>
2395 <li>RTSP (RTP, SDP)</li>
2396 <li>HTTP(S) progressive streaming</li>
2397 <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>
2398</ul>
2399
2400<h2 id="5_8_secure_media">5.8. Secure Media</h2>
2401
2402
2403<p>Device implementations that support secure video output and are capable of
2404supporting secure surfaces MUST declare support for Display.FLAG_SECURE. Device
2405implementations that declare support for Display.FLAG_SECURE, if they support a
2406wireless display protocol, MUST secure the link with a cryptographically strong
2407mechanism such as HDCP 2.x or higher for Miracast wireless displays. Similarly
2408if they support a wired external display, the device implementations MUST
2409support HDCP 1.2 or higher. Android Television device implementations MUST
2410support HDCP 2.2 for devices supporting 4K resolution and HDCP 1.4 or above for
2411lower resolutions. The upstream Android open source implementation includes
2412support for wireless (Miracast) and wired (HDMI) displays that satisfies this
2413requirement.</p>
2414
Glenn Kasten87ef61d2015-07-29 09:01:36 -0700[diff] [blame]2415<h2 id="5_9_midi">5.9. Musical Instrument Digital Interface (MIDI)</h2>
2416
2417<p>
2418If a device implementation supports the inter-app MIDI software transport
2419(virtual MIDI devices), and it supports MIDI over
2420<em>all</em> of the following MIDI-capable hardware transports
2421for which it provides generic non-MIDI connectivity, it MAY report
2422support for feature android.software.midi via the
2423android.content.pm.PackageManager class
2424[<a href="http://developer.android.com/reference/android/content/pm/PackageManager.html">Resources, 53</a>].
2425</p>
2426
2427<p>The MIDI-capable hardware transports are:</p>
2428<ul>
2429 <li>USB host mode (section 7.7 USB)</li>
2430 <li>USB peripheral mode (section 7.7 USB)</li>
2431</ul>
2432
2433<p>
2434Conversely, if the device implementation provides generic non-MIDI connectivity over a particular
2435MIDI-capable hardware transport listed above, but does not support MIDI over that hardware transport,
2436it MUST NOT report support for feature android.software.midi.
2437</p>
2438
2439<p>
2440MIDI over Bluetooth LE acting in central role (section 7.4.3 Bluetooth)
2441is in trial use status. A device implementation that reports
2442feature android.software.midi, and which provides generic non-MIDI connectivity
2443over Bluetooth LE, SHOULD support MIDI over Bluetooth LE.
2444</p>
2445
Glenn Kasten78eccbd2015-08-12 10:18:22 -0700[diff] [blame]2446<h2 id="5_10_pro_audio">5.10. Professional Audio</h2>
2447
2448<p>
2449If a device implementation meets <em>all</em> of the following requirements,
2450it MAY report support for feature android.hardware.audio.pro via the
2451android.content.pm.PackageManager class
2452[<a href="http://developer.android.com/reference/android/content/pm/PackageManager.html">Resources, 53</a>].
2453</p>
2454
2455<ul>
2456
2457<li>
Glenn Kasten1578ece2015-09-15 13:44:17 -0700[diff] [blame]2458The device implementation MUST report support for feature android.hardware.audio.low_latency.
Glenn Kasten78eccbd2015-08-12 10:18:22 -0700[diff] [blame]2459</li>
2460
2461<li> The continuous round-trip audio latency, as defined in section 5.6 Audio Latency,
2462MUST be 20 milliseconds or less and SHOULD be 10 milliseconds or less over at least one
2463supported path.
2464</li>
2465
2466<li>
Glenn Kasten1578ece2015-09-15 13:44:17 -0700[diff] [blame]2467If the device includes a 4 conductor 3.5mm audio jack,
Glenn Kasten78eccbd2015-08-12 10:18:22 -0700[diff] [blame]2468the continuous round-trip audio latency MUST be 20 milliseconds or less over the audio jack path,
2469and SHOULD be 10 milliseconds or less over at the audio jack path.
2470</li>
2471
2472<li>
2473The device implementation MUST include a USB port(s) supporting USB host mode and
2474USB peripheral mode.
2475</li>
2476
2477<li>
Glenn Kasten755f4b22015-09-25 16:04:23 -0700[diff] [blame]2478The USB host mode MUST implement the USB audio class.
Glenn Kasten78eccbd2015-08-12 10:18:22 -0700[diff] [blame]2479</li>
2480
2481<li>
2482If the device includes an HDMI port, the device implementation
Glenn Kasten1578ece2015-09-15 13:44:17 -0700[diff] [blame]2483MUST support output in stereo and eight channels
Glenn Kasten78eccbd2015-08-12 10:18:22 -0700[diff] [blame]2484at 20-bit or 24-bit depth and 192 kHz without bit-depth loss or resampling.
2485</li>
2486
2487<li>
2488The device implementation MUST report support for feature android.software.midi.
2489</li>
2490
Glenn Kasten1578ece2015-09-15 13:44:17 -0700[diff] [blame]2491<li>
2492If the device includes a 4 conductor 3.5mm audio jack,
Bert McMeen816a2422015-09-29 16:33:19 -0700[diff] [blame]2493the device implementation is STRONGLY RECOMMENDED to comply with section
Glenn Kasten1578ece2015-09-15 13:44:17 -0700[diff] [blame]2494<a href="https://source.android.com/accessories/headset/specification.html#mobile_device_jack_specifications">Mobile device (jack) specifications</a>
2495of the
2496<a href="https://source.android.com/accessories/headset/specification.html">Wired Audio Headset Specification (v1.1)</a>.
2497</li>
2498
Glenn Kasten78eccbd2015-08-12 10:18:22 -0700[diff] [blame]2499</ul>
2500
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]2501<h1 id="6_developer_tools_and_options_compatibility">6. Developer Tools and Options Compatibility</h1>
2502
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]2503<h2 id="6_1_developer_tools">6.1. Developer Tools</h2>
2504
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]2505<p>Device implementations MUST support the Android Developer Tools provided in the
2506Android SDK. Android compatible devices MUST be compatible with:</p>
2507
2508<ul>
2509 <li><strong>Android Debug Bridge (adb)</strong> [<a href="http://developer.android.com/tools/help/adb.html">Resources, 55</a>]</li>
2510</ul>
2511
2512<p>Device implementations MUST support all adb functions as documented in the
2513Android 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
2514user-accessible mechanism to turn on the Android Debug Bridge. If a device
2515implementation omits USB peripheral mode, it MUST implement the Android Debug
2516Bridge via local-area network (such as Ethernet or 802.11). </p>
2517
2518<p>Android includes support for secure adb. Secure adb enables adb on known
2519authenticated hosts. Device implementations MUST support secure adb.</p>
2520
2521<ul>
2522 <li><strong>Dalvik Debug Monitor Service (ddms)</strong> [<a href="http://developer.android.com/tools/debugging/ddms.html">Resources, 57</a>]</li>
2523</ul>
2524
2525<p>Device implementations MUST support all ddms features as documented in the
2526Android SDK. As ddms uses adb, support for ddms SHOULD be inactive by default,
2527but MUST be supported whenever the user has activated the Android Debug Bridge,
2528as above.</p>
2529
2530<ul>
2531 <li><strong>Monkey</strong> [<a href="http://developer.android.com/tools/help/monkey.html">Resources, 58</a>]</li>
2532</ul>
2533
2534<p>Device implementations MUST include the Monkey framework, and make it available
2535for applications to use.</p>
2536
2537<ul>
2538 <li><strong>SysTrace</strong> [<a href="http://developer.android.com/tools/help/systrace.html">Resources, 59</a>]</li>
2539</ul>
2540
2541<p>Device implementations MUST support systrace tool as documented in the Android
2542SDK. Systrace must be inactive by default, and there MUST be a user-accessible
2543mechanism to turn on Systrace.</p>
2544
2545<p>Most Linux-based systems and Apple Macintosh systems recognize Android devices
2546using the standard Android SDK tools, without additional support; however
2547Microsoft Windows systems typically require a driver for new Android devices.
2548(For instance, new vendor IDs and sometimes new device IDs require custom USB
2549drivers for Windows systems.) If a device implementation is unrecognized by the
2550adb tool as provided in the standard Android SDK, device implementers MUST
2551provide Windows drivers allowing developers to connect to the device using the
2552adb protocol. These drivers MUST be provided for Windows XP, Windows Vista,
Unsuk Jung5ad5aba2015-09-29 22:13:02 -0700[diff] [blame]2553Windows 7, Windows 8 and Windows 10 in both 32-bit and 64-bit versions.
2554</p>
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]2555
2556<h2 id="6_2_developer_options">6.2. Developer Options</h2>
2557
2558
2559<p>Android includes support for developers to configure application
2560development-related settings. Device implementations MUST honor the
2561android.settings.APPLICATION_DEVELOPMENT_SETTINGS intent to show application
2562development-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
2563default and enables users to launch Developer Options after pressing seven (7)
2564times on the <strong>Settings</strong> > <strong>About Device</strong> > <strong>Build Number</strong> menu item. Device implementations MUST provide a consistent experience for
2565Developer Options. Specifically, device implementations MUST hide Developer
2566Options by default and MUST provide a mechanism to enable Developer Options
2567that is consistent with the upstream Android implementation.</p>
2568
2569<h1 id="7_hardware_compatibility">7. Hardware Compatibility</h1>
2570
2571
2572<p>If a device includes a particular hardware component that has a corresponding
2573API for third-party developers, the device implementation MUST implement that
2574API as described in the Android SDK documentation. If an API in the SDK
2575interacts with a hardware component that is stated to be optional and the
2576device implementation does not possess that component:</p>
2577
2578<ul>
2579 <li>Complete class definitions (as documented by the SDK) for the component APIs
2580MUST still be presented.
2581 <li>The API&rsquo;s behaviors MUST be implemented as no-ops in some reasonable fashion.
2582 <li>API methods MUST return null values where permitted by the SDK documentation.
2583 <li>API methods MUST return no-op implementations of classes where null values are
2584not permitted by the SDK documentation.
2585 <li>API methods MUST NOT throw exceptions not documented by the SDK documentation.
2586</ul>
2587
2588<p>A typical example of a scenario where these requirements apply is the telephony
2589API: even on non-phone devices, these APIs must be implemented as reasonable
2590no-ops.</p>
2591
2592<p>Device implementations MUST consistently report accurate hardware configuration
2593information via the getSystemAvailableFeatures() and hasSystemFeature(String)
2594methods on the android.content.pm.PackageManager class for the same build
2595fingerprint. [<a href="http://developer.android.com/reference/android/content/pm/PackageManager.html">Resources, 53]</a></p>
2596
2597<h2 id="7_1_display_and_graphics">7.1. Display and Graphics</h2>
2598
2599
2600<p>Android includes facilities that automatically adjust application assets and UI
2601layouts appropriately for the device, to ensure that third-party applications
2602run 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
2603this section.</p>
2604
2605<p>The units referenced by the requirements in this section are defined as
2606follows:</p>
2607
2608<ul>
2609 <li><strong>physical diagonal size</strong>. The distance in inches between two opposing corners of the illuminated portion
2610of the display.</li>
2611 <li><strong>dots per inch (dpi)</strong>. The number of pixels encompassed by a linear horizontal or vertical span of
26121&rdquo;. Where dpi values are listed, both horizontal and vertical dpi must fall
2613within the range.</li>
2614 <li><strong>aspect ratio</strong>. The ratio of the pixels of the longer dimension
2615 to the shorter dimension of the screen. For example, a display of 480x854 pixels
2616 would be 854/480 = 1.779, or roughly &ldquo;16:9&rdquo;.</li>
2617 <li><strong>density-independent pixel (dp)</strong> The virtual pixel unit normalized to a 160 dpi screen, calculated as: pixels =
2618dps * (density/160).</li>
2619</ul>
2620
2621<h3 id="7_1_1_screen_configuration">7.1.1. Screen Configuration</h3>
2622
2623
2624<h4 id="7_1_1_1_screen_size">7.1.1.1. Screen Size</h4>
2625
2626<div class="note">
2627<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>
2628</div>
2629
2630<p>The Android UI framework supports a variety of different screen sizes, and
2631allows applications to query the device screen size (aka &ldquo;screen layout") via
2632android.content.res.Configuration.screenLayout with the SCREENLAYOUT_SIZE_MASK.
2633Device implementations MUST report the correct screen size as defined in the
2634Android 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
2635implementations MUST report the correct screen size according to the following
2636logical density-independent pixel (dp) screen dimensions.</p>
2637
2638<ul>
2639 <li>Devices MUST have screen sizes of at least 426 dp x 320 dp (&lsquo;small&rsquo;), unless it
2640is an Android Watch device.</li>
2641 <li>Devices that report screen size &lsquo;normal&rsquo; MUST have screen sizes of at least 480
2642dp x 320 dp.</li>
2643 <li>Devices that report screen size &lsquo;large&rsquo; MUST have screen sizes of at least 640
2644dp x 480 dp.</li>
2645 <li>Devices that report screen size &lsquo;xlarge&rsquo; MUST have screen sizes of at least 960
2646dp x 720 dp.</li>
2647</ul>
2648
2649<p>In addition, </p>
2650
2651<ul>
2652 <li>Android Watch devices MUST have a screen with the physical diagonal size in the
2653range from 1.1 to 2.5 inches.</li>
2654 <li>Other types of Android device implementations, with a physically integrated
2655screen, MUST have a screen at least 2.5 inches in physical diagonal size.</li>
2656</ul>
2657
2658<p>Devices MUST NOT change their reported screen size at any time.</p>
2659
2660<p>Applications optionally indicate which screen sizes they support via the
Unsuk Jung2e62f9a2015-07-16 23:01:44 -0700[diff] [blame]2661&lt;supports-screens&gt; attribute in the AndroidManifest.xml file. Device
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]2662implementations MUST correctly honor applications' stated support for small,
2663normal, large, and xlarge screens, as described in the Android SDK
2664documentation.</p>
2665
2666<h4 id="7_1_1_2_screen_aspect_ratio">7.1.1.2. Screen Aspect Ratio</h4>
2667
2668<div class="note">
2669<p>Android Watch devices MAY have an aspect ratio of 1.0 (1:1).</p>
2670</div>
2671
2672
2673<p>The screen aspect ratio MUST be a value from 1.3333 (4:3) to 1.86 (roughly
267416:9), but Android Watch devices MAY have an aspect ratio of 1.0 (1:1) because
2675such a device implementation will use a UI_MODE_TYPE_WATCH as the
2676android.content.res.Configuration.uiMode.</p>
2677
2678<h4 id="7_1_1_3_screen_density">7.1.1.3. Screen Density</h4>
2679
2680
2681<p>The Android UI framework defines a set of standard logical densities to help
2682application developers target application resources. Device implementations
2683MUST report only one of the following logical Android framework densities
2684through the android.util.DisplayMetrics APIs, and MUST execute applications at
2685this standard density and MUST NOT change the value at at any time for the
2686default display.</p>
2687
2688<ul>
2689 <li>120 dpi (ldpi)</li>
2690 <li>160 dpi (mdpi)</li>
2691 <li>213 dpi (tvdpi)</li>
2692 <li>240 dpi (hdpi)</li>
2693 <li>280 dpi (280dpi)</li>
2694 <li>320 dpi (xhdpi)</li>
2695 <li>400 dpi (400dpi)</li>
2696 <li>480 dpi (xxhdpi)</li>
2697 <li>560 dpi (560dpi)</li>
2698 <li>640 dpi (xxxhdpi)</li>
2699</ul>
2700
2701<p>Device implementations SHOULD define the standard Android framework density
2702that is numerically closest to the physical density of the screen, unless that
2703logical density pushes the reported screen size below the minimum supported. If
2704the standard Android framework density that is numerically closest to the
2705physical density results in a screen size that is smaller than the smallest
2706supported compatible screen size (320 dp width), device implementations SHOULD
2707report the next lowest standard Android framework density.</p>
2708
2709<h3 id="7_1_2_display_metrics">7.1.2. Display Metrics</h3>
2710
2711
2712<p>Device implementations MUST report correct values for all display metrics
2713defined 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
2714external screen is used as the default display.</p>
2715
2716<h3 id="7_1_3_screen_orientation">7.1.3. Screen Orientation</h3>
2717
2718
2719<p>Devices MUST report which screen orientations they support
2720(android.hardware.screen.portrait and/or android.hardware.screen.landscape) and
2721MUST report at least one supported orientation. For example, a device with a
2722fixed orientation landscape screen, such as a television or laptop, SHOULD only
2723report android.hardware.screen.landscape.</p>
2724
2725<p>Devices that report both screen orientations MUST support dynamic orientation
2726by applications to either portrait or landscape screen orientation. That is,
2727the device must respect the application&rsquo;s request for a specific screen
2728orientation. Device implementations MAY select either portrait or landscape
2729orientation as the default.</p>
2730
2731<p>Devices MUST report the correct value for the device&rsquo;s current orientation,
2732whenever queried via the android.content.res.Configuration.orientation,
2733android.view.Display.getOrientation(), or other APIs.</p>
2734
2735<p>Devices MUST NOT change the reported screen size or density when changing
2736orientation.</p>
2737
2738<h3 id="7_1_4_2d_and_3d_graphics_acceleration">7.1.4. 2D and 3D Graphics Acceleration</h3>
2739
2740
2741<p>Device implementations MUST support both OpenGL ES 1.0 and 2.0, as embodied and
2742detailed in the Android SDK documentations. Device implementations SHOULD
2743support OpenGL ES 3.0 or 3.1 on devices capable of supporting it. Device
2744implementations MUST also support Android RenderScript, as detailed in the
2745Android SDK documentation [<a href="http://developer.android.com/guide/topics/renderscript/">Resources, 63</a>].</p>
2746
2747<p>Device implementations MUST also correctly identify themselves as supporting
2748OpenGL ES 1.0, OpenGL ES 2.0, OpenGL ES 3.0 or OpenGL 3.1. That is:</p>
2749
2750<ul>
Unsuk Jung2e62f9a2015-07-16 23:01:44 -0700[diff] [blame]2751 <li>The managed APIs (such as via the GLES10.getString() method) MUST report support
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]2752for OpenGL ES 1.0 and OpenGL ES 2.0.</li>
2753 <li>The native C/C++ OpenGL APIs (APIs available to apps via libGLES_v1CM.so,
2754libGLES_v2.so, or libEGL.so) MUST report support for OpenGL ES 1.0 and OpenGL
2755ES 2.0.</li>
2756 <li>Device implementations that declare support for OpenGL ES 3.0 or 3.1 MUST
2757support the corresponding managed APIs and include support for native C/C++
2758APIs. On device implementations that declare support for OpenGL ES 3.0 or 3.1,
2759libGLESv2.so MUST export the corresponding function symbols in addition to the
2760OpenGL ES 2.0 function symbols.</li>
2761</ul>
2762
2763<p>In addition to OpenGL ES 3.1, Android provides an extension pack with Java
2764interfaces [<a href="https://developer.android.com/reference/android/opengl/GLES31Ext.html">Resources, 64</a>] and native support for advanced graphics functionality such as tessellation
2765and the ASTC texture compression format. Android device implementations MAY
2766support this extension pack, and&mdash;only if fully implemented&mdash;MUST identify the
2767support through the android.hardware.opengles.aep feature flag.</p>
2768
2769<p>Also, device implementations MAY implement any desired OpenGL ES extensions.
2770However, device implementations MUST report via the OpenGL ES managed and
2771native APIs all extension strings that they do support, and conversely MUST NOT
2772report extension strings that they do not support.</p>
2773
2774<p>Note that Android includes support for applications to optionally specify that
2775they require specific OpenGL texture compression formats. These formats are
2776typically vendor-specific. Device implementations are not required by Android
2777to implement any specific texture compression format. However, they SHOULD
2778accurately report any texture compression formats that they do support, via the
2779getString() method in the OpenGL API.</p>
2780
2781<p>Android includes a mechanism for applications to declare that they want to
2782enable hardware acceleration for 2D graphics at the Application, Activity,
2783Window, or View level through the use of a manifest tag
2784android:hardwareAccelerated or direct API calls [<a href="http://developer.android.com/guide/topics/graphics/hardware-accel.html">Resources, 65</a>].</p>
2785
2786<p>Device implementations MUST enable hardware acceleration by default, and MUST
2787disable hardware acceleration if the developer so requests by setting
2788android:hardwareAccelerated="false&rdquo; or disabling hardware acceleration directly
2789through the Android View APIs.</p>
2790
2791<p>In addition, device implementations MUST exhibit behavior consistent with the
2792Android SDK documentation on hardware acceleration [<a href="http://developer.android.com/guide/topics/graphics/hardware-accel.html">Resources, 65</a>].</p>
2793
2794<p>Android includes a TextureView object that lets developers directly integrate
2795hardware-accelerated OpenGL ES textures as rendering targets in a UI hierarchy.
2796Device implementations MUST support the TextureView API, and MUST exhibit
2797consistent behavior with the upstream Android implementation.</p>
2798
2799<p>Android includes support for EGL_ANDROID_RECORDABLE, an EGLConfig attribute
2800that indicates whether the EGLConfig supports rendering to an ANativeWindow
2801that records images to a video. Device implementations MUST support
2802EGL_ANDROID_RECORDABLE extension [<a href="https://www.khronos.org/registry/egl/extensions/ANDROID/EGL_ANDROID_recordable.txt">Resources, 66</a>].</p>
2803
2804<h3 id="7_1_5_legacy_application_compatibility_mode">7.1.5. Legacy Application Compatibility Mode</h3>
2805
2806
2807<p>Android specifies a &ldquo;compatibility mode&rdquo; in which the framework operates in a
2808'normal' screen size equivalent (320dp width) mode for the benefit of legacy
2809applications not developed for old versions of Android that pre-date
2810screen-size independence.</p>
2811
2812<ul>
2813<li>Android Automotive does not support legacy compatibility mode.</li>
2814<li>All other device implementations MUST include support for legacy application
2815compatibility mode as implemented by the upstream Android open source code. That
2816is, device implementations MUST NOT alter the triggers or thresholds at which
2817compatibility mode is activated, and MUST NOT alter the behavior of the
2818compatibility mode itself.</li>
2819</ul>
2820
2821<h3 id="7_1_6_screen_technology">7.1.6. Screen Technology</h3>
2822
2823
2824<p>The Android platform includes APIs that allow applications to render rich
2825graphics to the display. Devices MUST support all of these APIs as defined by
2826the Android SDK unless specifically allowed in this document. </p>
2827
2828<ul>
2829 <li>Devices MUST support displays capable of rendering 16-bit color graphics and
2830SHOULD support displays capable of 24-bit color graphics.</li>
2831 <li>Devices MUST support displays capable of rendering animations.</li>
2832 <li>The display technology used MUST have a pixel aspect ratio (PAR) between 0.9
2833and 1.15. That is, the pixel aspect ratio MUST be near square (1.0) with a 10 ~
283415% tolerance.</li>
2835</ul>
2836
2837<h3 id="7_1_7_external_displays">7.1.7. Secondary Displays</h3>
2838
2839
2840<p>Android includes support for secondary display to enable media sharing
2841capabilities and developer APIs for accessing external displays. If a device
2842supports an external display either via a wired, wireless, or an embedded
2843additional display connection then the device implementation MUST implement the
2844display 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>
2845
2846<h2 id="7_2_input_devices">7.2. Input Devices</h2>
2847
2848<p>Devices MUST support a touchscreen or meet the requirements listed in 7.2.2
2849for non-touch navigation.</p>
2850
2851<h3 id="7_2_1_keyboard">7.2.1. Keyboard</h3>
2852
2853<div class="note">
2854<p>Android Watch and Android Automotive implementations MAY implement a soft
2855keyboard. All other device implementations MUST implement a soft keyboard and:</p>
2856</div>
2857
2858
2859<p>Device implementations:</p>
2860
2861<ul>
2862 <li>MUST include support for the Input Management Framework (which allows
2863third-party developers to create Input Method Editors&mdash;i.e. soft keyboard) as
2864detailed at <a href="http://developer.android.com">http://developer.android.com</a>.</li>
2865 <li>MUST provide at least one soft keyboard implementation (regardless of whether a
2866hard keyboard is present) except for Android Watch devices where the screen
2867size makes it less reasonable to have a soft keyboard.</li>
2868 <li>MAY include additional soft keyboard implementations.</li>
2869 <li>MAY include a hardware keyboard.</li>
2870 <li>MUST NOT include a hardware keyboard that does not match one of the formats
2871specified 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>
2872</ul>
2873
2874<h3 id="7_2_2_non-touch_navigation">7.2.2. Non-touch Navigation</h3>
2875
2876<div class="note">
2877<p>Android Television devices MUST support D-pad.</p>
2878</div>
2879
2880<p>Device implementations:</p>
2881
2882<ul>
2883 <li>MAY omit a non-touch navigation option (trackball, d-pad, or wheel) if the
2884device implementation is not an Android Television device.</li>
2885 <li>MUST report the correct value for android.content.res.Configuration.navigation
2886[<a href="http://developer.android.com/reference/android/content/res/Configuration.html">Resources, 68</a>].</li>
2887 <li>MUST provide a reasonable alternative user interface mechanism for the
2888selection and editing of text, compatible with Input Management Engines. The
2889upstream Android open source implementation includes a selection mechanism
2890suitable for use with devices that lack non-touch navigation inputs.</li>
2891</ul>
2892
2893<h3 id="7_2_3_navigation_keys">7.2.3. Navigation Keys</h3>
2894
2895<div class="note">
2896<p>The availability and visibility requirement of the Home, Recents, and Back
2897functions differ between device types as described in this section.</p>
2898</div>
2899
2900<p>The Home, Recents, and Back functions (mapped to the key events KEYCODE_HOME,
2901KEYCODE_APP_SWITCH, KEYCODE_BACK, respectively) are essential to the Android
2902navigation paradigm and therefore:</p>
2903
2904<ul>
2905 <li>Android Handheld device implementations MUST provide the Home, Recents, and
2906Back functions.</li>
2907 <li>Android Television device implementations MUST provide the Home and Back
2908functions.</li>
2909 <li>Android Watch device implementations MUST have the Home function available to
2910the user, and the Back function except for when it is in UI_MODE_TYPE_WATCH.</li>
2911 <li>Android Automotive implementations MUST provide the Home function and MAY
2912provide Back and Recent functions.</li>
2913 <li>All other types of device implementations MUST provide the Home and Back
2914functions.</li>
2915</ul>
2916
2917<p>These functions MAY be implemented via dedicated physical buttons (such as
2918mechanical or capacitive touch buttons), or MAY be implemented using dedicated
2919software keys on a distinct portion of the screen, gestures, touch panel, etc.
2920Android supports both implementations. All of these functions MUST be
2921accessible with a single action (e.g. tap, double-click or gesture) when
2922visible.</p>
2923
2924<p>Recents function, if provided, MUST have a visible button or icon unless hidden
2925together with other navigation functions in full-screen mode. This does not
2926apply to devices upgrading from earlier Android versions that have physical
2927buttons for navigation and no recents key.</p>
2928
2929<p> The Home and Back functions, if provided, MUST each have a visible button or
2930icon unless hidden together with other navigation functions in full-screen mode
2931or when the uiMode UI_MODE_TYPE_MASK is set to UI_MODE_TYPE_WATCH.</p>
2932
2933<p>The Menu function is deprecated in favor of action bar since Android 4.0.
2934Therefore the new device implementations shipping with Android ANDROID_VERSION and later MUST NOT
2935implement a dedicated physical button for the Menu function. Older device
2936implementations SHOULD NOT implement a dedicated physical button for the Menu
2937function, but if the physical Menu button is implemented and the device is
2938running applications with targetSdkVersion > 10, the device implementation:</p>
2939
2940<ul>
2941 <li>MUST display the action overflow button on the action bar when it is visible
2942and the resulting action overflow menu popup is not empty. For a device
2943implementation launched before Android 4.4 but upgrading to Android ANDROID_VERSION, this
2944is RECOMMENDED.</li>
2945 <li>MUST NOT modify the position of the action overflow popup displayed by
2946selecting the overflow button in the action bar.</li>
2947 <li>MAY render the action overflow popup at a modified position on the screen when
2948it is displayed by selecting the physical menu button.</li>
2949</ul>
2950
2951<p>For backwards compatibility, device implementations MUST make the Menu function
2952available to applications when targetSdkVersion is less than 10, either by a physical
2953button, a software key, or gestures. This Menu function should be presented
2954unless hidden together with other navigation functions.</p>
2955
2956<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
2957the Assist action available to the user at all times when running applications.
2958The Assist action SHOULD be implemented as a long-press on the Home button or a
2959swipe-up gesture on the software Home key. This function MAY be implemented via
2960another physical button, software key, or gesture, but MUST be accessible with
2961a single action (e.g. tap, double-click, or gesture) when other navigation keys
2962are visible.</p>
2963
2964<p>Device implementations MAY use a distinct portion of the screen to display the
2965navigation keys, but if so, MUST meet these requirements:</p>
2966
2967<ul>
2968 <li>Device implementation navigation keys MUST use a distinct portion of the
2969screen, not available to applications, and MUST NOT obscure or otherwise
2970interfere with the portion of the screen available to applications.</li>
2971 <li>Device implementations MUST make available a portion of the display to
2972applications that meets the requirements defined in <a href="#7_1_1_screen_configuration">section 7.1.1</a>.</li>
2973 <li>Device implementations MUST display the navigation keys when applications do
2974not specify a system UI mode, or specify SYSTEM_UI_FLAG_VISIBLE.</li>
2975 <li>Device implementations MUST present the navigation keys in an unobtrusive &ldquo;low
2976profile&rdquo; (eg. dimmed) mode when applications specify
2977SYSTEM_UI_FLAG_LOW_PROFILE.</li>
2978 <li>Device implementations MUST hide the navigation keys when applications specify
2979SYSTEM_UI_FLAG_HIDE_NAVIGATION.</li>
2980</ul>
2981
2982<h3 id="7_2_4_touchscreen_input">7.2.4. Touchscreen Input</h3>
2983
2984<div class="note">
2985<p>Android Handhelds and Watch Devices MUST support touchscreen input.</p>
2986</div>
2987
2988
2989<p>Device implementations SHOULD have a pointer input system of some kind (either
2990mouse-like or touch). However, if a device implementation does not support a
2991pointer input system, it MUST NOT report the android.hardware.touchscreen or
2992android.hardware.faketouch feature constant. Device implementations that do
2993include a pointer input system:</p>
2994
2995<ul>
2996 <li>SHOULD support fully independently tracked pointers, if the device input system
2997supports multiple pointers.</li>
2998 <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>
2999</ul>
3000
3001<p>Android includes support for a variety of touchscreens, touch pads, and fake
3002touch input devices. Touchscreen based device implementations are associated
3003with 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
3004screen. Since the user is directly touching the screen, the system does not
3005require any additional affordances to indicate the objects being manipulated.
3006In contrast, a fake touch interface provides a user input system that
3007approximates a subset of touchscreen capabilities. For example, a mouse or
3008remote control that drives an on-screen cursor approximates touch, but requires
3009the user to first point or focus then click. Numerous input devices like the
3010mouse, trackpad, gyro-based air mouse, gyro-pointer, joystick, and multi-touch
3011trackpad can support fake touch interactions. Android includes the feature
3012constant android.hardware.faketouch, which corresponds to a high-fidelity
3013non-touch (pointer-based) input device such as a mouse or trackpad that can
3014adequately emulate touch-based input (including basic gesture support), and
3015indicates that the device supports an emulated subset of touchscreen
3016functionality. Device implementations that declare the fake touch feature MUST
3017meet the fake touch requirements in <a href="#7_2_5_fake_touch_input">section 7.2.5</a>.</p>
3018
3019<p>Device implementations MUST report the correct feature corresponding to the
3020type of input used. Device implementations that include a touchscreen
3021(single-touch or better) MUST report the platform feature constant
3022android.hardware.touchscreen. Device implementations that report the platform
3023feature constant android.hardware.touchscreen MUST also report the platform
3024feature constant android.hardware.faketouch. Device implementations that do not
3025include a touchscreen (and rely on a pointer device only) MUST NOT report any
3026touchscreen feature, and MUST report only android.hardware.faketouch if they
3027meet the fake touch requirements in <a href="#7_2_5_fake_touch_input">section 7.2.5</a>.</p>
3028
3029<h3 id="7_2_5_fake_touch_input">7.2.5. Fake Touch Input</h3>
3030
3031
3032<p>Device implementations that declare support for android.hardware.faketouch:</p>
3033
3034<ul>
3035 <li>MUST report the absolute X and Y screen positions of the pointer location and
3036display a visual pointer on the screen [<a href="http://developer.android.com/reference/android/view/MotionEvent.html">Resources, 71</a>].</li>
3037 <li>MUST report touch event with the action code that specifies the state change
3038that 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>
3039 <li>MUST support pointer down and up on an object on the screen, which allows users
3040to emulate tap on an object on the screen.</li>
3041 <li>MUST support pointer down, pointer up, pointer down then pointer up in the same
3042place on an object on the screen within a time threshold, which allows users to
3043emulate double tap on an object on the screen [<a href="http://developer.android.com/reference/android/view/MotionEvent.html">Resources, 71</a>].</li>
3044 <li>MUST support pointer down on an arbitrary point on the screen, pointer move to
3045any other arbitrary point on the screen, followed by a pointer up, which allows
3046users to emulate a touch drag.</li>
3047 <li>MUST support pointer down then allow users to quickly move the object to a
3048different position on the screen and then pointer up on the screen, which
3049allows users to fling an object on the screen.</li>
3050</ul>
3051
3052<p>Devices that declare support for android.hardware.faketouch.multitouch.distinct
3053MUST meet the requirements for faketouch above, and MUST also support distinct
3054tracking of two or more independent pointer inputs.</p>
3055
3056<h3 id="7_2_6_game_controller_support">7.2.6. Game Controller Support</h3>
3057
3058
3059<p>Android Television device implementations MUST support button mappings for game
3060controllers as listed below. The upstream Android implementation includes
3061implementation for game controllers that satisfies this requirement. </p>
3062
3063<h4 id="7_2_6_1_button_mappings">7.2.6.1. Button Mappings</h4>
3064
3065
3066<p>Android Television device implementations MUST support the following key
3067mappings:</p>
3068<table>
3069 <tr>
3070 <th>Button</th>
3071 <th>HID Usage</strong><sup>2</sup></td>
3072 <th>Android Button</th>
3073 </tr>
3074 <tr>
3075 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BUTTON_A">A</a><sup>1</sup></td>
3076 <td>0x09 0x0001</td>
3077 <td>KEYCODE_BUTTON_A (96)</td>
3078 </tr>
3079 <tr>
3080 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BUTTON_B">B</a><sup>1</sup></td>
3081 <td>0x09 0x0002</td>
3082 <td>KEYCODE_BUTTON_B (97)</td>
3083 </tr>
3084 <tr>
3085 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BUTTON_X">X</a><sup>1</sup></td>
3086 <td>0x09 0x0004</td>
3087 <td>KEYCODE_BUTTON_X (99)</td>
3088 </tr>
3089 <tr>
3090 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BUTTON_Y">Y</a><sup>1</sup></td>
3091 <td>0x09 0x0005</td>
3092 <td>KEYCODE_BUTTON_Y (100)</td>
3093 </tr>
3094 <tr>
3095 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_DPAD_UP">D-pad up</a><sup>1</sup></p>
3096
3097<p><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_DPAD_DOWN">D-pad down</a><sup>1</sup></td>
Unsuk Jung2e62f9a2015-07-16 23:01:44 -0700[diff] [blame]3098 <td>0x01 0x0039<sup>3</sup></td>
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]3099 <td><a href="http://developer.android.com/reference/android/view/MotionEvent.html#AXIS_HAT_Y">AXIS_HAT_Y</a><sup>4</sup></td>
3100 </tr>
3101 <tr>
3102 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_DPAD_LEFT">D-pad left</a>1</p>
3103
3104<p><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_DPAD_RIGHT">D-pad right</a><sup>1</sup></td>
Unsuk Jung2e62f9a2015-07-16 23:01:44 -0700[diff] [blame]3105 <td>0x01 0x0039<sup>3</sup></td>
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]3106 <td><a href="http://developer.android.com/reference/android/view/MotionEvent.html#AXIS_HAT_X">AXIS_HAT_X</a><sup>4</sup></td>
3107 </tr>
3108 <tr>
3109 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BUTTON_L1">Left shoulder button</a><sup>1</sup></td>
3110 <td>0x09 0x0007</td>
3111 <td>KEYCODE_BUTTON_L1 (102)</td>
3112 </tr>
3113 <tr>
3114 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BUTTON_R1">Right shoulder button</a><sup>1</sup></td>
3115 <td>0x09 0x0008</td>
3116 <td>KEYCODE_BUTTON_R1 (103)</td>
3117 </tr>
3118 <tr>
3119 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BUTTON_THUMBL">Left stick click</a><sup>1</sup></td>
3120 <td>0x09 0x000E</td>
3121 <td>KEYCODE_BUTTON_THUMBL (106)</td>
3122 </tr>
3123 <tr>
3124 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BUTTON_THUMBR">Right stick click</a><sup>1</sup></td>
3125 <td>0x09 0x000F</td>
3126 <td>KEYCODE_BUTTON_THUMBR (107)</td>
3127 </tr>
3128 <tr>
3129 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_HOME">Home</a><sup>1</sup></td>
3130 <td>0x0c 0x0223</td>
3131 <td>KEYCODE_HOME (3)</td>
3132 </tr>
3133 <tr>
3134 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BACK">Back</a><sup>1</sup></td>
3135 <td>0x0c 0x0224</td>
3136 <td>KEYCODE_BACK (4)</td>
3137 </tr>
3138</table>
3139
3140
3141<p class="table_footnote">1 [<a href="http://developer.android.com/reference/android/view/KeyEvent.html">Resources, 72</a>]</p>
3142
3143<p class="table_footnote">2 The above HID usages must be declared within a Game pad CA (0x01 0x0005).</p>
3144
3145<p class="table_footnote">3 This usage must have a Logical Minimum of 0, a Logical Maximum of 7, a
3146Physical Minimum of 0, a Physical Maximum of 315, Units in Degrees, and a
3147Report Size of 4. The logical value is defined to be the clockwise rotation
3148away from the vertical axis; for example, a logical value of 0 represents no
3149rotation and the up button being pressed, while a logical value of 1 represents
3150a rotation of 45 degrees and both the up and left keys being pressed.</p>
3151
3152<p class="table_footnote">4 [<a href="http://developer.android.com/reference/android/view/MotionEvent.html">Resources, 71</a>]</p>
3153
3154<table>
3155 <tr>
3156 <th>Analog Controls</strong><sup>1</sup></td>
3157 <th>HID Usage</th>
3158 <th>Android Button</th>
3159 </tr>
3160 <tr>
3161 <td><a href="http://developer.android.com/reference/android/view/MotionEvent.html#AXIS_LTRIGGER">Left Trigger</a></td>
3162 <td>0x02 0x00C5</td>
3163 <td>AXIS_LTRIGGER </td>
3164 </tr>
3165 <tr>
3166 <td><a href="http://developer.android.com/reference/android/view/MotionEvent.html#AXIS_THROTTLE">Right Trigger</a></td>
3167 <td>0x02 0x00C4</td>
3168 <td>AXIS_RTRIGGER </td>
3169 </tr>
3170 <tr>
3171 <td><a href="http://developer.android.com/reference/android/view/MotionEvent.html#AXIS_Y">Left Joystick</a></td>
3172 <td>0x01 0x0030</p>
3173
3174<p>0x01 0x0031</td>
3175 <td>AXIS_X</p>
3176
3177<p>AXIS_Y</td>
3178 </tr>
3179 <tr>
3180 <td><a href="http://developer.android.com/reference/android/view/MotionEvent.html#AXIS_Z">Right Joystick</a></td>
3181 <td>0x01 0x0032</p>
3182
3183<p>0x01 0x0035</td>
3184 <td>AXIS_Z</p>
3185
3186<p>AXIS_RZ</td>
3187 </tr>
3188</table>
3189
3190
3191<p class="table_footnote">1 [<a href="http://developer.android.com/reference/android/view/MotionEvent.html">Resources, 71</a>]</p>
3192
3193<h3 id="7_2_7_remote_control">7.2.7. Remote Control</h3>
3194
3195
3196<p>Android Television device implementations SHOULD provide a remote control to
3197allow users to access the TV interface. The remote control MAY be a physical
3198remote or can be a software-based remote that is accessible from a mobile phone
3199or tablet. The remote control MUST meet the requirements defined below.</p>
3200
3201<ul>
3202 <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>
3203 <li><strong>Navigation</strong>. All Android Television remotes MUST include Back, Home, and Select buttons and
3204support for D-pad events [<a href="http://developer.android.com/reference/android/view/KeyEvent.html">Resources, 72</a>].</li>
3205</ul>
3206
3207<h2 id="7_3_sensors">7.3. Sensors</h2>
3208
3209
3210<p>Android includes APIs for accessing a variety of sensor types. Devices
3211implementations generally MAY omit these sensors, as provided for in the
3212following subsections. If a device includes a particular sensor type that has a
3213corresponding API for third-party developers, the device implementation MUST
3214implement that API as described in the Android SDK documentation and the
3215Android Open Source documentation on sensors [<a href="http://source.android.com/devices/sensors/">Resources, 73</a>]. For example, device implementations:</p>
3216
3217<ul>
3218 <li>MUST accurately report the presence or absence of sensors per the
3219android.content.pm.PackageManager class [<a href="http://developer.android.com/reference/android/content/pm/PackageManager.html">Resources, 53]</a>.</li>
3220 <li>MUST return an accurate list of supported sensors via the
3221SensorManager.getSensorList() and similar methods.</li>
3222 <li>MUST behave reasonably for all other sensor APIs (for example, by returning
3223true or false as appropriate when applications attempt to register listeners,
3224not calling sensor listeners when the corresponding sensors are not present;
3225etc.).</li>
3226 <li>MUST report all sensor measurements using the relevant International System of
3227Units (metric) values for each sensor type as defined in the Android SDK
3228documentation [<a href="http://developer.android.com/reference/android/hardware/SensorEvent.html">Resources, 74</a>].</li>
3229 <li>SHOULD report the event time in nanoseconds as defined in the Android SDK
3230documentation, representing the time the event happened and synchronized with
3231the SystemClock.elapsedRealtimeNano() clock. Existing and new Android devices
Bert McMeen816a2422015-09-29 16:33:19 -0700[diff] [blame]3232are <strong>STRONGLY RECOMMENDED</strong> to meet these requirement so they will be able to upgrade to the future
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]3233platform releases where this might become a REQUIRED component. The
3234synchronization error SHOULD be below 100 milliseconds [<a href="http://developer.android.com/reference/android/hardware/SensorEvent.html#timestamp">Resources, 75</a>].</li>
3235</ul>
3236
3237<p>The list above is not comprehensive; the documented behavior of the Android SDK
3238and the Android Open Source Documentations on Sensors [<a href="http://source.android.com/devices/sensors/">Resources, 73</a>] is to be considered authoritative.</p>
3239
3240<p>Some sensor types are composite, meaning they can be derived from data provided
3241by one or more other sensors. (Examples include the orientation sensor, and the
3242linear acceleration sensor.) Device implementations SHOULD implement these
3243sensor types, when they include the prerequisite physical sensors as described
3244in [<a href="https://source.android.com/devices/sensors/sensor-types.html">Resources, 76</a>].
3245If a device implementation includes a composite sensor it MUST implement the
3246sensor as described in the Android Open Source documentation on composite
3247sensors [<a href="https://source.android.com/devices/sensors/sensor-types.html#composite_sensor_type_summary">Resources, 76</a>].</p>
3248
3249<p>Some Android sensors support a &ldquo;continuous&rdquo; trigger mode, which returns data
3250continuously [<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
3251sensor, device implementations MUST continuously provide periodic data samples
3252that SHOULD have a jitter below 3%, where jitter is defined as the standard
3253deviation of the difference of the reported timestamp values between
3254consecutive events.</p>
3255
3256<p>Note that the device implementations MUST ensure that the sensor event stream
3257MUST NOT prevent the device CPU from entering a suspend state or waking up from
3258a suspend state.</p>
3259
3260<p>Finally, when several sensors are activated, the power consumption SHOULD NOT
3261exceed the sum of the individual sensor&rsquo;s reported power consumption.</p>
3262
3263<h3 id="7_3_1_accelerometer">7.3.1. Accelerometer</h3>
3264
3265
3266<p>Device implementations SHOULD include a 3-axis accelerometer. Android Handheld
Bert McMeen816a2422015-09-29 16:33:19 -0700[diff] [blame]3267devices and Android Watch devices are STRONGLY RECOMMENDED to include this
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]3268sensor. If a device implementation does include a 3-axis accelerometer, it:</p>
3269
3270<ul>
3271 <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>
3272 <li>MUST be able to report events up to a frequency of at least 50 Hz for
3273 Android Watch devices as such devices have a stricter power constraint and
3274 100 Hz for all other device types.</li>
3275 <li>SHOULD report events up to at least 200 Hz.</li>
3276 <li>MUST comply with the Android sensor coordinate system as detailed in the
3277Android APIs [<a href="http://developer.android.com/reference/android/hardware/SensorEvent.html">Resources, 74</a>].</li>
3278 <li>MUST be capable of measuring from freefall up to four times the gravity (4g) or
3279more on any axis.</li>
3280 <li>MUST have a resolution of at least 8-bits and SHOULD have a resolution of at
3281least 16-bits.</li>
3282 <li>SHOULD be calibrated while in use if the characteristics changes over the life
3283cycle and compensated, and preserve the compensation parameters between device
3284reboots.</li>
3285 <li>SHOULD be temperature compensated.</li>
3286 <li>MUST have a standard deviation no greater than 0.05 m/s^, where the standard
3287deviation should be calculated on a per axis basis on samples collected over a
3288period of at least 3 seconds at the fastest sampling rate.</li>
3289 <li>SHOULD implement the TYPE_SIGNIFICANT_MOTION, TYPE_TILT_DETECTOR,
3290TYPE_STEP_DETECTOR, TYPE_STEP_COUNTER composite sensors as described in the
Bert McMeen816a2422015-09-29 16:33:19 -0700[diff] [blame]3291Android SDK document. Existing and new Android devices are <strong>STRONGLY RECOMMENDED</strong> to implement the TYPE_SIGNIFICANT_MOTION composite sensor. If any of these
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]3292sensors are implemented, the sum of their power consumption MUST always be less
3293than 4 mW and SHOULD each be below 2 mW and 0.5 mW for when the device is in a
3294dynamic or static condition.</li>
3295 <li>If a gyroscope sensor is included, MUST implement the TYPE_GRAVITY and
3296TYPE_LINEAR_ACCELERATION composite sensors and SHOULD implement the
3297TYPE_GAME_ROTATION_VECTOR composite sensor. Existing and new Android devices
Bert McMeen816a2422015-09-29 16:33:19 -0700[diff] [blame]3298are STRONGLY RECOMMENDED to implement the TYPE_GAME_ROTATION_VECTOR sensor.</li>
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]3299 <li>SHOULD implement a TYPE_ROTATION_VECTOR composite sensor, if a gyroscope sensor
3300and a magnetometer sensor is also included.</li>
3301</ul>
3302
3303<h3 id="7_3_2_magnetometer">7.3.2. Magnetometer</h3>
3304
3305
3306<p>Device implementations SHOULD include a 3-axis magnetometer (compass). If a
3307device does include a 3-axis magnetometer, it:</p>
3308
3309<ul>
3310 <li>MUST implement the TYPE_MAGNETIC_FIELD sensor and SHOULD also implement
3311TYPE_MAGNETIC_FIELD_UNCALIBRATED sensor. Existing and new Android devices are
Bert McMeen816a2422015-09-29 16:33:19 -0700[diff] [blame]3312STRONGLY RECOMMENDED to implement the TYPE_MAGNETIC_FIELD_UNCALIBRATED sensor.</li>
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]3313 <li>MUST be able to report events up to a frequency of at least 10 Hz and SHOULD
3314report events up to at least 50 Hz.</li>
3315 <li>MUST comply with the Android sensor coordinate system as detailed in the
3316Android APIs [<a href="http://developer.android.com/reference/android/hardware/SensorEvent.html">Resources, 74</a>].</li>
3317 <li>MUST be capable of measuring between -900 &micro;T and +900 &micro;T on each axis before
3318saturating.</li>
3319 <li>MUST have a hard iron offset value less than 700 &micro;T and SHOULD have a value
3320below 200 &micro;T, by placing the magnetometer far from dynamic (current-induced)
3321and static (magnet-induced) magnetic fields.</li>
3322 <li>MUST have a resolution equal or denser than 0.6 &micro;T and SHOULD have a resolution
3323equal or denser than 0.2 &micro;.</li>
3324 <li>SHOULD be temperature compensated.</li>
3325 <li>MUST support online calibration and compensation of the hard iron bias, and
3326preserve the compensation parameters between device reboots.</li>
3327 <li>MUST have the soft iron compensation applied&mdash;the calibration can be done either
3328while in use or during the production of the device.</li>
3329 <li>SHOULD have a standard deviation, calculated on a per axis basis on samples
3330collected over a period of at least 3 seconds at the fastest sampling rate, no
3331greater than 0.5 &micro;T.</li>
3332 <li>SHOULD implement a TYPE_ROTATION_VECTOR composite sensor, if an accelerometer
3333sensor and a gyroscope sensor is also included.</li>
3334 <li>MAY implement the TYPE_GEOMAGNETIC_ROTATION_VECTOR sensor if an accelerometer
3335sensor is also implemented. However if implemented, it MUST consume less than
333610 mW and SHOULD consume less than 3 mW when the sensor is registered for batch
3337mode at 10 Hz.</li>
3338</ul>
3339
3340<h3 id="7_3_3_gps">7.3.3. GPS</h3>
3341
3342
3343<p>Device implementations SHOULD include a GPS receiver. If a device
3344implementation does include a GPS receiver, it SHOULD include some form of&ldquo;assisted GPS&rdquo; technique to minimize GPS lock-on time.</p>
3345
3346<h3 id="7_3_4_gyroscope">7.3.4. Gyroscope</h3>
3347
3348
3349<p>Device implementations SHOULD include a gyroscope (angular change sensor).
3350Devices SHOULD NOT include a gyroscope sensor unless a 3-axis accelerometer is
3351also included. If a device implementation includes a gyroscope, it:</p>
3352
3353<ul>
3354 <li>MUST implement the TYPE_GYROSCOPE sensor and SHOULD also implement
3355TYPE_GYROSCOPE_UNCALIBRATED sensor. Existing and new Android devices are
Bert McMeen816a2422015-09-29 16:33:19 -0700[diff] [blame]3356STRONGLY RECOMMENDED to implement the SENSOR_TYPE_GYROSCOPE_UNCALIBRATED sensor.</li>
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]3357 <li>MUST be capable of measuring orientation changes up to 1,000 degrees per second.</li>
3358 <li>MUST be able to report events up to a frequency of at least 50 Hz for
3359 Android Watch devices as such devices have a stricter power constraint and
3360 100 Hz for all other device types.</li>
3361 <li>SHOULD report events up to at least 200 Hz.</li>
3362 <li>MUST have a resolution of 12-bits or more and SHOULD have a resolution of
336316-bits or more.</li>
3364 <li>MUST be temperature compensated.</li>
3365 <li>MUST be calibrated and compensated while in use, and preserve the compensation
3366parameters between device reboots.</li>
3367 <li>MUST have a variance no greater than 1e-7 rad^2 / s^2 per Hz (variance per Hz,
3368or rad^2 / s). The variance is allowed to vary with the sampling rate, but must
3369be constrained by this value. In other words, if you measure the variance of
3370the gyro at 1 Hz sampling rate it should be no greater than 1e-7 rad^2/s^2.</li>
3371 <li>SHOULD implement a TYPE_ROTATION_VECTOR composite sensor, if an accelerometer
3372sensor and a magnetometer sensor is also included.</li>
3373 <li>If an accelerometer sensor is included, MUST implement the TYPE_GRAVITY and
3374TYPE_LINEAR_ACCELERATION composite sensors and SHOULD implement the
3375TYPE_GAME_ROTATION_VECTOR composite sensor. Existing and new Android devices
Bert McMeen816a2422015-09-29 16:33:19 -0700[diff] [blame]3376are STRONGLY RECOMMENDED to implement the TYPE_GAME_ROTATION_VECTOR sensor.</li>
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]3377</ul>
3378
3379<h3 id="7_3_5_barometer">7.3.5. Barometer</h3>
3380
3381
3382<p>Device implementations SHOULD include a barometer (ambient air pressure
3383sensor). If a device implementation includes a barometer, it:</p>
3384
3385<ul>
3386 <li>MUST implement and report TYPE_PRESSURE sensor.</li>
3387 <li>MUST be able to deliver events at 5 Hz or greater.</li>
3388 <li>MUST have adequate precision to enable estimating altitude.</li>
3389 <li>MUST be temperature compensated.</li>
3390</ul>
3391
3392<h3 id="7_3_6_thermometer">7.3.6. Thermometer</h3>
3393
3394
3395<p>Device implementations MAY include an ambient thermometer (temperature sensor).
3396If present, it MUST be defined as SENSOR_TYPE_AMBIENT_TEMPERATURE and it MUST
3397measure the ambient (room) temperature in degrees Celsius.</p>
3398
3399<p>Device implementations MAY but SHOULD NOT include a CPU temperature sensor. If
3400present, it MUST be defined as SENSOR_TYPE_TEMPERATURE, it MUST measure the
3401temperature of the device CPU, and it MUST NOT measure any other temperature.
3402Note the SENSOR_TYPE_TEMPERATURE sensor type was deprecated in Android 4.0.</p>
3403
3404<h3 id="7_3_7_photometer">7.3.7. Photometer</h3>
3405
3406
3407<p>Device implementations MAY include a photometer (ambient light sensor).</p>
3408
3409<h3 id="7_3_8_proximity_sensor">7.3.8. Proximity Sensor</h3>
3410
3411
3412<p>Device implementations MAY include a proximity sensor. Devices that can make a
3413voice call and indicate any value other than PHONE_TYPE_NONE in getPhoneType
3414SHOULD include a proximity sensor. If a device implementation does include a
3415proximity sensor, it:</p>
3416
3417<ul>
3418 <li>MUST measure the proximity of an object in the same direction as the screen.
3419That is, the proximity sensor MUST be oriented to detect objects close to the
3420screen, as the primary intent of this sensor type is to detect a phone in use
3421by the user. If a device implementation includes a proximity sensor with any
3422other orientation, it MUST NOT be accessible through this API.</li>
3423 <li>MUST have 1-bit of accuracy or more.</li>
3424</ul>
3425
3426<h2 id="7_4_data_connectivity">7.4. Data Connectivity</h2>
3427
3428
3429<h3 id="7_4_1_telephony">7.4.1. Telephony</h3>
3430
3431
3432<p>&ldquo;Telephony&rdquo; as used by the Android APIs and this document refers specifically
3433to hardware related to placing voice calls and sending SMS messages via a GSM
3434or CDMA network. While these voice calls may or may not be packet-switched,
3435they are for the purposes of Android considered independent of any data
3436connectivity that may be implemented using the same network. In other words,
3437the Android &ldquo;telephony&rdquo; functionality and APIs refer specifically to voice
3438calls and SMS. For instance, device implementations that cannot place calls or
3439send/receive SMS messages MUST NOT report the android.hardware.telephony
3440feature or any subfeatures, regardless of whether they use a cellular network
3441for data connectivity.</p>
3442
3443<p>Android MAY be used on devices that do not include telephony hardware. That is,
3444Android is compatible with devices that are not phones. However, if a device
3445implementation does include GSM or CDMA telephony, it MUST implement full
3446support for the API for that technology. Device implementations that do not
3447include telephony hardware MUST implement the full APIs as no-ops.</p>
3448
3449<h3 id="7_4_2_ieee_802_11_wi-fi">7.4.2. IEEE 802.11 (Wi-Fi)</h3>
3450
3451<div class="note">
3452<p>Android Television device implementations MUST include Wi-Fi support.</p>
3453</div>
3454
3455
3456<p>Android Television device implementations MUST include support for one or more
3457forms of 802.11 (b/g/a/n, etc.) and other types of Android device
3458implementation SHOULD include support for one or more forms of 802.11. If a
3459device implementation does include support for 802.11 and exposes the
3460functionality to a third-party application, it MUST implement the corresponding
3461Android API and:</p>
3462
3463<ul>
3464 <li>MUST report the hardware feature flag android.hardware.wifi.</li>
3465 <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>
3466 <li>MUST support multicast DNS (mDNS) and MUST NOT filter mDNS packets
3467(224.0.0.251) at any time of operation including when the screen is not in an
3468active state.</li>
3469</ul>
3470
3471<h4 id="7_4_2_1_wi-fi_direct">7.4.2.1. Wi-Fi Direct</h4>
3472
3473
3474<p>Device implementations SHOULD include support for Wi-Fi Direct (Wi-Fi
3475peer-to-peer). If a device implementation does include support for Wi-Fi
3476Direct, it MUST implement the corresponding Android API as described in the SDK
3477documentation [<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>
3478
3479<ul>
3480 <li>MUST report the hardware feature android.hardware.wifi.direct.</li>
3481 <li>MUST support regular Wi-Fi operation.</li>
3482 <li>SHOULD support concurrent Wi-Fi and Wi-Fi Direct operation.</li>
3483</ul>
3484
3485<h4 id="7_4_2_2_wi-fi_tunneled_direct_link_setup">7.4.2.2. Wi-Fi Tunneled Direct Link Setup</h4>
3486
3487<div class="note">
3488<p>Android Television device implementations MUST include support for Wi-Fi
3489Tunneled Direct Link Setup (TDLS).</p>
3490</div>
3491
3492
3493<p>Android Television device implementations MUST include support for Wi-Fi
3494Tunneled Direct Link Setup (TDLS) and other types of Android device
3495implementations SHOULD include support for Wi-Fi TDLS as described in the
3496Android 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
3497by the WiFiManager API, the device:</p>
3498
3499<ul>
3500 <li>SHOULD use TDLS only when it is possible AND beneficial.</li>
3501 <li>SHOULD have some heuristic and NOT use TDLS when its performance might be worse
3502than going through the Wi-Fi access point.</li>
3503</ul>
3504
3505<h3 id="7_4_3_bluetooth">7.4.3. Bluetooth</h3>
3506
3507<div class="note">
3508<p>Android Watch and Automotive implementations MUST support Bluetooth. Android
3509Television implementations MUST support Bluetooth and Bluetooth LE.</p>
3510</div>
3511
3512
3513<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
3514Energy MUST declare the relevant platform features (android.hardware.bluetooth
3515and android.hardware.bluetooth_le respectively) and implement the platform
3516APIs. Device implementations SHOULD implement relevant Bluetooth profiles such
3517as A2DP, AVCP, OBEX, etc. as appropriate for the device. Android Television
3518device implementations MUST support Bluetooth and Bluetooth LE. </p>
3519
3520<p>Device implementations including support for Bluetooth Low Energy:</p>
3521
3522<ul>
3523 <li>MUST declare the hardware feature android.hardware.bluetooth_le.</li>
3524 <li>MUST enable the GATT (generic attribute profile) based Bluetooth APIs as
3525described in the SDK documentation and [<a href="http://developer.android.com/reference/android/bluetooth/package-summary.html">Resources, 82</a>].</li>
3526 <li>SHOULD support offloading of the filtering logic to the bluetooth chipset when
3527implementing 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
3528android.bluetooth.BluetoothAdapter.isOffloadedFilteringSupported() method.</li>
3529 <li>SHOULD support offloading of the batched scanning to the bluetooth chipset, but
3530if not supported, MUST report &lsquo;false&rsquo; whenever queried via the
3531android.bluetooth.BluetoothAdapater.isOffloadedScanBatchingSupported() method.</li>
3532 <li>SHOULD support multi advertisement with at least 4 slots, but if not supported,
3533MUST report &lsquo;false&rsquo; whenever queried via the
3534android.bluetooth.BluetoothAdapter.isMultipleAdvertisementSupported() method.</li>
3535</ul>
3536
3537<h3 id="7_4_4_near-field_communications">7.4.4. Near-Field Communications</h3>
3538
3539
3540<p>Device implementations SHOULD include a transceiver and related hardware for
3541Near-Field Communications (NFC). If a device implementation does include NFC
3542hardware and plans to make it available to third-party apps, then it:</p>
3543
3544<ul>
3545 <li>MUST report the android.hardware.nfc feature from the
3546android.content.pm.PackageManager.hasSystemFeature() method [<a href="http://developer.android.com/reference/android/content/pm/PackageManager.html">Resources, 53</a>].</li>
3547 <li>MUST be capable of reading and writing NDEF messages via the following NFC
3548standards:
3549 <ul>
3550 <li>MUST be capable of acting as an NFC Forum reader/writer (as defined by the NFC
3551Forum technical specification NFCForum-TS-DigitalProtocol-1.0) via the
3552following NFC standards:
3553 <ul>
3554 <li>NfcA (ISO14443-3A)</li>
3555 <li>NfcB (ISO14443-3B)</li>
Martijn Coenen048f4aa2015-09-17 14:24:55 +0200[diff] [blame]3556 <li>NfcF (JIS X 6319-4)</li>
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]3557 <li>IsoDep (ISO 14443-4)</li>
3558 <li>NFC Forum Tag Types 1, 2, 3, 4 (defined by the NFC Forum)</li>
3559 </ul>
Martijn Coenen048f4aa2015-09-17 14:24:55 +0200[diff] [blame]3560 <li>MUST be capable of reading and writing NDEF messages as well as raw
3561 data via the following NFC standards:</li>
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]3562 <ul>
3563 <li>NfcV (ISO 15693)</li>
3564 </ul></li>
Martijn Coenen048f4aa2015-09-17 14:24:55 +0200[diff] [blame]3565 <li>SHOULD be capable of reading the barcode and URL (if encoded) of
3566 Thinfilm NFC Barcode
3567 [<a href="http://developer.android.com/reference/android/nfc/tech/NfcBarcode.html">Resources, XX</a>] products.
3568 </li>
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]3569 <li>MUST be capable of transmitting and receiving data via the following
3570peer-to-peer standards and protocols:
3571 <ul>
3572 <li>ISO 18092</li>
Martijn Coenen048f4aa2015-09-17 14:24:55 +0200[diff] [blame]3573 <li>LLCP 1.2 (defined by the NFC Forum)</li>
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]3574 <li>SDP 1.0 (defined by the NFC Forum)</li>
3575 <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>
3576 <li>SNEP 1.0 (defined by the NFC Forum)</li>
3577 </ul></li>
3578 <li>MUST include support for Android Beam [<a href="http://developer.android.com/guide/topics/connectivity/nfc/nfc.html">Resources, 85</a>]:
3579 <ul>
3580 <li>MUST implement the SNEP default server. Valid NDEF messages received by the
3581default SNEP server MUST be dispatched to applications using the
3582android.nfc.ACTION_NDEF_DISCOVERED intent. Disabling Android Beam in settings
3583MUST NOT disable dispatch of incoming NDEF message.</li>
3584 <li>MUST honor the android.settings.NFCSHARING_SETTINGS intent to show NFC sharing
3585settings [<a href="http://developer.android.com/reference/android/provider/Settings.html#ACTION_NFCSHARING_SETTINGS">Resources, 86</a>].</li>
3586 <li>MUST implement the NPP server. Messages received by the NPP server MUST be
3587processed the same way as the SNEP default server.</li>
3588 <li>MUST implement a SNEP client and attempt to send outbound P2P NDEF to the
3589default SNEP server when Android Beam is enabled. If no default SNEP server is
3590found then the client MUST attempt to send to an NPP server.</li>
3591 <li>MUST allow foreground activities to set the outbound P2P NDEF message using
3592android.nfc.NfcAdapter.setNdefPushMessage, and
3593android.nfc.NfcAdapter.setNdefPushMessageCallback, and
3594android.nfc.NfcAdapter.enableForegroundNdefPush.</li>
3595 <li>SHOULD use a gesture or on-screen confirmation, such as 'Touch to Beam', before
3596sending outbound P2P NDEF messages.</li>
3597 <li>SHOULD enable Android Beam by default and MUST be able to send and receive
3598using Android Beam, even when another proprietary NFC P2p mode is turned on.</li>
3599 <li>MUST support NFC Connection handover to Bluetooth when the device supports
3600Bluetooth Object Push Profile. Device implementations MUST support connection
3601handover to Bluetooth when using android.nfc.NfcAdapter.setBeamPushUris, by
3602implementing 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
3603LLCP service with service name &ldquo;urn:nfc:sn:handover&rdquo; for exchanging the
3604handover request/select records over NFC, and it MUST use the Bluetooth Object
3605Push Profile for the actual Bluetooth data transfer. For legacy reasons (to
3606remain compatible with Android 4.1 devices), the implementation SHOULD still
3607accept SNEP GET requests for exchanging the handover request/select records
3608over NFC. However an implementation itself SHOULD NOT send SNEP GET requests
3609for performing connection handover.</li>
3610 </ul></li>
3611 <li>MUST poll for all supported technologies while in NFC discovery mode.</li>
3612 <li>SHOULD be in NFC discovery mode while the device is awake with the screen
3613active and the lock-screen unlocked.</li>
3614</ul>
3615</ul>
3616
3617<p>(Note that publicly available links are not available for the JIS, ISO, and NFC
3618Forum specifications cited above.)</p>
3619
3620<p>Android includes support for NFC Host Card Emulation (HCE) mode. If a
3621device implementation does include an NFC controller chipset capable of HCE and
3622Application ID (AID) routing, then it:</p>
3623
3624<ul>
3625 <li>MUST report the android.hardware.nfc.hce feature constant.</li>
3626 <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>
3627</ul>
3628
3629<p>Additionally, device implementations MAY include reader/writer support for the
3630following MIFARE technologies.</p>
3631
3632<ul>
3633 <li>MIFARE Classic</li>
3634 <li>MIFARE Ultralight</li>
3635 <li>NDEF on MIFARE Classic</li>
3636</ul>
3637
3638<p>Note that Android includes APIs for these MIFARE types. If a device
3639implementation supports MIFARE in the reader/writer role, it:</p>
3640
3641<ul>
3642 <li>MUST implement the corresponding Android APIs as documented by the Android SDK.</li>
3643 <li>MUST report the feature com.nxp.mifare from the
Martijn Coenen048f4aa2015-09-17 14:24:55 +0200[diff] [blame]3644android.content.pm.PackageManager.hasSystemFeature() method <a href="http://developer.android.com/reference/android/content/pm/PackageManager.html">[Resources, 53]</a>. Note that this is not a standard Android feature and as such does not appear
3645as a constant in the android.content.pm.PackageManager class.</li>
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]3646 <li>MUST NOT implement the corresponding Android APIs nor report the com.nxp.mifare
3647feature unless it also implements general NFC support as described in this
3648section.</li>
3649</ul>
3650
3651<p>If a device implementation does not include NFC hardware, it MUST NOT declare
3652the android.hardware.nfc feature from the
3653android.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>
3654
3655<p>As the classes android.nfc.NdefMessage and android.nfc.NdefRecord represent a
3656protocol-independent data representation format, device implementations MUST
3657implement these APIs even if they do not include support for NFC or declare the
3658android.hardware.nfc feature.</p>
3659
3660<h3 id="7_4_5_minimum_network_capability">7.4.5. Minimum Network Capability</h3>
3661
3662
3663<p>Device implementations MUST include support for one or more forms of data
3664networking. Specifically, device implementations MUST include support for at
3665least one data standard capable of 200Kbit/sec or greater. Examples of
3666technologies that satisfy this requirement include EDGE, HSPA, EV-DO, 802.11g,
3667Ethernet, Bluetooth PAN, etc.</p>
3668
3669<p>Device implementations where a physical networking standard (such as Ethernet)
3670is the primary data connection SHOULD also include support for at least one
3671common wireless data standard, such as 802.11 (Wi-Fi).</p>
3672
3673<p>Devices MAY implement more than one form of data connectivity.</p>
3674
3675<h3 id="7_4_6_sync_settings">7.4.6. Sync Settings</h3>
3676
3677
3678<p>Device implementations MUST have the master auto-sync setting on by default so
3679that the method getMasterSyncAutomatically() returns &ldquo;true&rdquo; [<a href="http://developer.android.com/reference/android/content/ContentResolver.html">Resources, 89</a>].</p>
3680
3681<h2 id="7_5_cameras">7.5. Cameras</h2>
3682
3683
3684<p>Device implementations SHOULD include a rear-facing camera and MAY include a
3685front-facing camera. A rear-facing camera is a camera located on the side of
3686the device opposite the display; that is, it images scenes on the far side of
3687the device, like a traditional camera. A front-facing camera is a camera
3688located on the same side of the device as the display; that is, a camera
3689typically used to image the user, such as for video conferencing and similar
3690applications.</p>
3691
3692<p>If a device implementation includes at least one camera, it SHOULD be possible
3693for an application to simultaneously allocate 3 bitmaps equal to the size of
3694the images produced by the largest-resolution camera sensor on the device.</p>
3695
3696<h3 id="7_5_1_rear-facing_camera">7.5.1. Rear-Facing Camera</h3>
3697
3698
3699<p>Device implementations SHOULD include a rear-facing camera. If a device
3700implementation includes at least one rear-facing camera, it:</p>
3701
3702<ul>
3703 <li>MUST report the feature flag android.hardware.camera and
3704android.hardware.camera.any.</li>
3705 <li>MUST have a resolution of at least 2 megapixels.</li>
3706 <li>SHOULD have either hardware auto-focus or software auto-focus implemented in
3707the camera driver (transparent to application software).</li>
3708 <li>MAY have fixed-focus or EDOF (extended depth of field) hardware.</li>
3709 <li>MAY include a flash. If the Camera includes a flash, the flash lamp MUST NOT be
3710lit while an android.hardware.Camera.PreviewCallback instance has been
3711registered on a Camera preview surface, unless the application has explicitly
3712enabled the flash by enabling the FLASH_MODE_AUTO or FLASH_MODE_ON attributes
3713of a Camera.Parameters object. Note that this constraint does not apply to the
3714device&rsquo;s built-in system camera application, but only to third-party
3715applications using Camera.PreviewCallback.</li>
3716</ul>
3717
3718<h3 id="7_5_2_front-facing_camera">7.5.2. Front-Facing Camera</h3>
3719
3720
3721<p>Device implementations MAY include a front-facing camera. If a device
3722implementation includes at least one front-facing camera, it:</p>
3723
3724<ul>
3725 <li>MUST report the feature flag android.hardware.camera.any and
3726android.hardware.camera.front.</li>
3727 <li>MUST have a resolution of at least VGA (640x480 pixels).</li>
3728 <li>MUST NOT use a front-facing camera as the default for the Camera API. The
3729camera API in Android has specific support for front-facing cameras and device
3730implementations MUST NOT configure the API to to treat a front-facing camera as
3731the default rear-facing camera, even if it is the only camera on the device.</li>
3732 <li>MAY include features (such as auto-focus, flash, etc.) available to rear-facing
3733cameras as described in <a href="#7_5_1_rear-facing_camera">section 7.5.1</a>.</li>
3734 <li>MUST horizontally reflect (i.e. mirror) the stream displayed by an app in a
3735CameraPreview, as follows:
3736 <ul>
3737 <li>If the device implementation is capable of being rotated by user (such as
3738automatically via an accelerometer or manually via user input), the camera
3739preview MUST be mirrored horizontally relative to the device&rsquo;s current
3740orientation.</li>
3741 <li>If the current application has explicitly requested that the Camera display be
3742rotated 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
3743orientation specified by the application.</li>
3744 <li>Otherwise, the preview MUST be mirrored along the device&rsquo;s default horizontal
3745axis.</li>
3746 </ul></li>
3747 <li>MUST mirror the image displayed by the postview in the same manner as the
3748camera preview image stream. If the device implementation does not support
3749postview, this requirement obviously does not apply.</li>
3750 <li>MUST NOT mirror the final captured still image or video streams returned to
3751application callbacks or committed to media storage.</li>
3752</ul>
3753
3754<h3 id="7_5_3_external_camera">7.5.3. External Camera</h3>
3755
3756
3757<p>Device implementations with USB host mode MAY include support for an external
3758camera that connects to the USB port. If a device includes support for an
3759external camera, it:</p>
3760
3761<ul>
3762 <li>MUST declare the platform feature android.hardware.camera.external and
3763android.hardware camera.any.</li>
3764 <li>MUST support USB Video Class (UVC 1.0 or higher).</li>
3765 <li>MAY support multiple cameras.</li>
3766</ul>
3767
3768<p>Video compression (such as MJPEG) support is RECOMMENDED to enable transfer of
3769high-quality unencoded streams (i.e. raw or independently compressed picture
3770streams). Camera-based video encoding MAY be supported. If so, a simultaneous
3771unencoded/ MJPEG stream (QVGA or greater resolution) MUST be accessible to the
3772device implementation.</p>
3773
3774<h3 id="7_5_4_camera_api_behavior">7.5.4. Camera API Behavior</h3>
3775
3776
3777<p>Android includes two API packages to access the camera, the newer
3778android.hardware.camera2 API expose lower-level camera control to the app,
3779including efficient zero-copy burst/streaming flows and per-frame controls of
3780exposure, gain, white balance gains, color conversion, denoising, sharpening,
3781and more.</p>
3782
3783<p>The older API package, android.hardware.Camera, is marked as deprecated in
3784Android 5.0 but as it should still be available for apps to use Android device
3785implementations MUST ensure the continued support of the API as described in
3786this section and in the Android SDK.</p>
3787
3788<p>Device implementations MUST implement the following behaviors for the
3789camera-related APIs, for all available cameras:</p>
3790
3791<ul>
3792 <li>If an application has never called
3793android.hardware.Camera.Parameters.setPreviewFormat(int), then the device MUST
3794use android.hardware.PixelFormat.YCbCr_420_SP for preview data provided to
3795application callbacks.</li>
3796 <li>If an application registers an android.hardware.Camera.PreviewCallback instance
3797and the system calls the onPreviewFrame() method when the preview format is
3798YCbCr_420_SP, the data in the byte[] passed into onPreviewFrame() must further
3799be in the NV21 encoding format. That is, NV21 MUST be the default.</li>
3800 <li>For android.hardware.Camera, device implementations MUST support the YV12
3801format (as denoted by the android.graphics.ImageFormat.YV12 constant) for
3802camera previews for both front- and rear-facing cameras. (The hardware video
3803encoder and camera may use any native pixel format, but the device
3804implementation MUST support conversion to YV12.)</li>
3805 <li>For android.hardware.camera2, device implementations must support the
3806android.hardware.ImageFormat.YUV_420_888 and android.hardware.ImageFormat.JPEG
3807formats as outputs through the android.media.ImageReader API.</li>
3808</ul>
3809
3810<p>Device implementations MUST still implement the full Camera API included in the
3811Android 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
3812capabilities. For instance, cameras that lack autofocus MUST still call any
3813registered android.hardware.Camera.AutoFocusCallback instances (even though
3814this has no relevance to a non-autofocus camera.) Note that this does apply to
3815front-facing cameras; for instance, even though most front-facing cameras do
3816not support autofocus, the API callbacks must still be &ldquo;faked&rdquo; as described.</p>
3817
3818<p>Device implementations MUST recognize and honor each parameter name defined as
3819a constant on the android.hardware.Camera.Parameters class, if the underlying
3820hardware supports the feature. If the device hardware does not support a
3821feature, the API must behave as documented. Conversely, device implementations
3822MUST NOT honor or recognize string constants passed to the
3823android.hardware.Camera.setParameters() method other than those documented as
3824constants on the android.hardware.Camera.Parameters. That is, device
3825implementations MUST support all standard Camera parameters if the hardware
3826allows, and MUST NOT support custom Camera parameter types. For instance,
3827device implementations that support image capture using high dynamic range
3828(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>
3829
3830<p>Because not all device implementations can fully support all the features of
3831the android.hardware.camera2 API, device implementations MUST report the proper
3832level of support with the android.info.supportedHardwareLevel property as
3833described 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>
3834
3835<p>Device implementations MUST also declare its Individual camera capabilities of
3836android.hardware.camera2 via the android.request.availableCapabilities property
3837and 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>
3838
3839<p>Device implementations MUST broadcast the Camera.ACTION_NEW_PICTURE intent
3840whenever a new picture is taken by the camera and the entry of the picture has
3841been added to the media store.</p>
3842
3843<p>Device implementations MUST broadcast the Camera.ACTION_NEW_VIDEO intent
3844whenever a new video is recorded by the camera and the entry of the picture has
3845been added to the media store.</p>
3846
3847<h3 id="7_5_5_camera_orientation">7.5.5. Camera Orientation</h3>
3848
3849
3850<p>Both front- and rear-facing cameras, if present, MUST be oriented so that the
3851long dimension of the camera aligns with the screen&rsquo;s long dimension. That is,
3852when the device is held in the landscape orientation, cameras MUST capture
3853images in the landscape orientation. This applies regardless of the device&rsquo;s
3854natural orientation; that is, it applies to landscape-primary devices as well
3855as portrait-primary devices.</p>
3856
3857<h2 id="7_6_memory_and_storage">7.6. Memory and Storage</h2>
3858
3859
3860<h3 id="7_6_1_minimum_memory_and_storage">7.6.1. Minimum Memory and Storage</h3>
3861
3862<div class="note">
3863<p>Android Television devices MUST have at least 5GB of non-volatile storage
3864available for application private data.</p>
3865</div>
3866
3867
3868<p>The memory available to the kernel and userspace on device implementations MUST
3869be at least equal or larger than the minimum values specified by the following
3870table. (See <a href="#7_1_1_screen_configuration">section 7.1.1</a> for screen size and density definitions.)</p>
3871<table>
3872 <tr>
3873 <th>Density and screen size</th>
3874 <th>32-bit device</th>
3875 <th>64-bit device</th>
3876 </tr>
3877 <tr>
3878 <td>Android Watch devices (due to smaller screens)</td>
3879 <td>416MB</td>
3880 <td>Not applicable</td>
3881 </tr>
3882 <tr>
3883 <td><ul>
Unsuk Jung2e62f9a2015-07-16 23:01:44 -0700[diff] [blame]3884 <li class="table_list">280dpi or lower on small/normal screens</li>
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]3885 <li class="table_list">mdpi or lower on large screens</li>
3886 <li class="table_list">ldpi or lower on extra large screens</li>
3887 </ul></td>
3888 <td>424MB</td>
Unsuk Jung2e62f9a2015-07-16 23:01:44 -0700[diff] [blame]3889 <td>704MB</td>
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]3890 </tr>
3891 <tr>
3892 <td><ul>
3893 <li class="table_list">xhdpi or higher on small/normal screens</li>
3894 <li class="table_list">hdpi or higher on large screens</li>
3895 <li class="table_list">mdpi or higher on extra large screens</li></ul></td>
3896 <td>512MB</td>
3897 <td>832MB</td>
3898 </tr>
3899 <tr>
3900 <td><ul>
3901 <li class="table_list">400dpi or higher on small/normal screens</li>
3902 <li class="table_list">xhdpi or higher on large screens</li>
3903 <li class="table_list">tvdpi or higher on extra large screens</li></ul></td>
3904 <td>896MB</td>
3905 <td>1280MB</td>
3906 </tr>
3907 <tr>
3908 <td><ul>
3909 <li class="table_list">560dpi or higher on small/normal screens</li>
3910 <li class="table_list">400dpi or higher on large screens</li>
3911 <li class="table_list">xhdpi or higher on extra large screens</li></ul></td>
3912 <td>1344MB</td>
3913 <td>1824MB</td>
3914 </tr>
3915</table>
3916
3917
3918<p>The minimum memory values MUST be in addition to any memory space already
3919dedicated to hardware components such as radio, video, and so on that is not
3920under the kernel&rsquo;s control.</p>
3921
3922<p>Device implementations with less than 512MB of memory available to the kernel
3923and userspace, unless an Android Watch, MUST return the value "true" for
3924ActivityManager.isLowRamDevice().</p>
3925
3926<p>Android Television devices MUST have at least 5GB and other device
3927implementations MUST have at least 1.5GB of non-volatile storage available for
3928application private data. That is, the /data partition MUST be at least 5GB for
3929Android Television devices and at least 1.5GB for other device implementations.
Bert McMeen816a2422015-09-29 16:33:19 -0700[diff] [blame]3930Device implementations that run Android are <strong>STRONGLY RECOMMENDED</strong> to have at least 3GB of non-volatile storage for application private data so
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]3931they will be able to upgrade to the future platform releases.</p>
3932
3933<p>The Android APIs include a Download Manager that applications MAY use to
3934download 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
3935downloading individual files of at least 100MB in size to the default &ldquo;cache"
3936location.</p>
3937
3938<h3 id="7_6_2_application_shared_storage">7.6.2. Application Shared Storage</h3>
3939
3940
3941<p>Device implementations MUST offer shared storage for applications also often
3942referred as &ldquo;shared external storage&rdquo;. </p>
3943
3944<p>Device implementations MUST be configured with shared storage mounted by
3945default, &ldquo;out of the box&rdquo;. If the shared storage is not mounted on the Linux
3946path /sdcard, then the device MUST include a Linux symbolic link from /sdcard
3947to the actual mount point.</p>
3948
3949<p>Device implementations MAY have hardware for user-accessible removable storage,
3950such as a Secure Digital (SD) card slot. If this slot is used to satisfy the
3951shared storage requirement, the device implementation:</p>
3952
3953<ul>
3954 <li>MUST implement a toast or pop-up user interface warning the user when there is
3955no SD card.</li>
3956 <li>MUST include a FAT-formatted SD card 1GB in size or larger OR show on the box
3957and other material available at time of purchase that the SD card has to be
3958separately purchased.</li>
3959 <li>MUST mount the SD card by default.</li>
3960</ul>
3961
3962<p>Alternatively, device implementations MAY allocate internal (non-removable)
3963storage as shared storage for apps as included in the upstream Android Open
3964Source Project; device implementations SHOULD use this configuration and
3965software implementation. If a device implementation uses internal
3966(non-removable) storage to satisfy the shared storage requirement, that storage
3967MUST be 1GB in size or larger and mounted on /sdcard (or /sdcard MUST be a
3968symbolic link to the physical location if it is mounted elsewhere).</p>
3969
3970<p>Device implementations MUST enforce as documented the
3971android.permission.WRITE_EXTERNAL_STORAGE permission on this shared storage.
3972Shared storage MUST otherwise be writable by any application that obtains that
3973permission.</p>
3974
3975<p>Device implementations that include multiple shared storage paths (such as both
3976an SD card slot and shared internal storage) MUST NOT allow Android
3977applications to write to the secondary external storage, except for their
3978package-specific directories on the secondary external storage, but SHOULD
3979expose content from both storage paths transparently through Android&rsquo;s media
3980scanner service and android.provider.MediaStore.</p>
3981
3982<p>Regardless of the form of shared storage used, if the device implementation
3983has a USB port with USB peripheral mode support, it MUST provide some mechanism
3984to access the contents of shared storage from a host computer. Device
3985implementations MAY use USB mass storage, but SHOULD use Media Transfer Protocol
3986to satisfy this requirement. If the device implementation supports Media
3987Transfer Protocol, it:</p>
3988
3989<ul>
3990 <li>SHOULD be compatible with the reference Android MTP host, Android File Transfer
3991[<a href="http://www.android.com/filetransfer">Resources, 96</a>].</li>
3992 <li>SHOULD report a USB device class of 0x00.</li>
3993 <li>SHOULD report a USB interface name of 'MTP'.</li>
3994</ul>
3995
3996<h2 id="7_7_usb">7.7. USB</h2>
3997
3998
3999<p>Device implementations SHOULD support USB peripheral mode and SHOULD support
4000USB host mode.</p>
4001
4002<p>If a device implementation includes a USB port supporting peripheral mode:</p>
4003
4004<ul>
4005 <li>The port MUST be connectable to a USB host that has a standard type-A or type
4006-C USB port.</li>
4007 <li>The port SHOULD use micro-A, micro-AB or type-C USB form factor. Existing and
Bert McMeen816a2422015-09-29 16:33:19 -0700[diff] [blame]4008new Android devices are <strong>STRONGLY RECOMMENDED to meet these requirements</strong> so they will be able to upgrade to the future platform releases.</li>
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]4009 <li>The port SHOULD be centered in the middle of an edge. Device implementations
4010SHOULD either locate the port on the bottom of the device (according to natural
4011orientation) or enable software screen rotation for all apps (including home
4012screen), so that the display draws correctly when the device is oriented with
Bert McMeen816a2422015-09-29 16:33:19 -0700[diff] [blame]4013the port at bottom. Existing and new Android devices are <strong>STRONGLY RECOMMENDED to meet these requirements</strong> so they will be able to upgrade to future platform releases.</li>
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]4014 <li>It MUST allow a USB host connected with the Android device to access the
4015contents of the shared storage volume using either USB mass storage or Media
4016Transfer Protocol.</li>
4017 <li>It SHOULD implement the Android Open Accessory (AOA) API and specification as
4018documented in the Android SDK documentation, and if it is an Android Handheld
4019device it MUST implement the AOA API. Device implementations implementing the
4020AOA specification:
4021 <ul>
4022 <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>
4023 <li>MUST implement the USB audio class as documented in the Android SDK
4024documentation [<a href="http://developer.android.com/reference/android/hardware/usb/UsbConstants.html#USB_CLASS_AUDIO">Resources, 98</a>].</li>
Unsuk Jungd94638a2015-09-29 20:50:56 -0700[diff] [blame]4025 <li>And also the USB mass storage class, MUST include the string "android"
4026at the end of the interface description <code>iInterface</code> string of the
4027USB mass storage</li>
4028 </ul>
4029 </li>
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]4030 <li>It SHOULD implement support to draw 1.5 A current during HS chirp and traffic
Bert McMeen816a2422015-09-29 16:33:19 -0700[diff] [blame]4031as 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>STRONGLY RECOMMENDED to meet these requirements</strong> so they will be able to upgrade to the future platform releases.</li>
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]4032 <li>The value of iSerialNumber in USB standard device descriptor MUST be equal to
4033the value of android.os.Build.SERIAL.</li>
4034</ul>
4035
4036<p>If a device implementation includes a USB port supporting host mode, it:</p>
4037
4038<ul>
4039 <li>SHOULD use a type-C USB port, if the device implementation supports USB 3.1.</li>
4040 <li>MAY use a non-standard port form factor, but if so MUST ship with a cable or
4041cables adapting the port to a standard type-A or type-C USB port.</li>
4042 <li>MAY use a micro-AB USB port, but if so SHOULD ship with a cable or cables
4043adapting the port to a standard type-A or type-C USB port.</li>
4044 <li>is <strong>very strongly RECOMMENDED</strong> to implement the USB audio class as documented in the Android SDK
4045documentation [<a href="http://developer.android.com/reference/android/hardware/usb/UsbConstants.html#USB_CLASS_AUDIO">Resources, 98</a>].</li>
4046 <li>MUST implement the Android USB host API as documented in the Android SDK, and
4047MUST 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>
4048 <li>SHOULD support the Charging Downstream Port output current range of 1.5 A ~ 5 A
4049as 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>
4050</ul>
4051
4052<h2 id="7_8_audio">7.8. Audio</h2>
4053
4054
4055<h3 id="7_8_1_microphone">7.8.1. Microphone</h3>
4056
4057<div class="note">
4058<p>Android Handheld, Watch, and Automotive implementations MUST include a
4059microphone.</p>
4060</div>
4061
4062
4063<p>Device implementations MAY omit a microphone. However, if a device
4064implementation omits a microphone, it MUST NOT report the
4065android.hardware.microphone feature constant, and MUST implement the audio
Glenn Kasten20cdbb72015-09-24 11:56:42 -0700[diff] [blame]4066recording API at least as no-ops, per <a href="#7_hardware_compatibility">section 7</a>.
4067Conversely, device implementations that do possess a microphone:</p>
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]4068
4069<ul>
Glenn Kasten20cdbb72015-09-24 11:56:42 -0700[diff] [blame]4070 <li>MUST report the android.hardware.microphone feature constant</li>
4071 <li>MUST meet the audio recording requirements in <a href="#5_4_audio_recording">section 5.4</a></li>
4072 <li>MUST meet the audio latency requirements in <a href="#5_6_audio_latency">section 5.6</a></li>
4073 <li>STRONGLY RECOMMENDED to support near-ultrasound recording as described in
4074 <a href="#7_8_3_near_ultrasound">section 7.8.3</a></li>
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]4075</ul>
4076
4077<h3 id="7_8_2_audio_output">7.8.2. Audio Output</h3>
4078
4079<div class="note">
4080<p>Android Watch devices MAY include an audio output.</p>
4081</div>
4082
4083<p>Device implementations including a speaker or with an audio/multimedia output
4084port for an audio output peripheral as a headset or an external speaker:</p>
4085
4086<ul>
4087 <li>MUST report the android.hardware.audio.output feature constant.</li>
4088 <li>MUST meet the audio playback requirements in <a href="#5_5_audio_playback">section 5.5</a>.</li>
4089 <li>MUST meet the audio latency requirements in <a href="#5_6_audio_latency">section 5.6</a>.</li>
Glenn Kasten20cdbb72015-09-24 11:56:42 -0700[diff] [blame]4090 <li>STRONGLY RECOMMENDED to support near-ultrasound playback as described in
4091 <a href="#7_8_3_near_ultrasound">section 7.8.3</a></li>
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]4092</ul>
4093
4094<p>Conversely, if a device implementation does not include a speaker or audio
4095output port, it MUST NOT report the android.hardware.audio output feature, and
4096MUST implement the Audio Output related APIs as no-ops at least. </p>
4097
4098<p>Android Watch device implementation MAY but SHOULD NOT have audio output, but
4099other types of Android device implementations MUST have an audio output and
4100declare android.hardware.audio.output.</p>
4101
4102<h4 id="7_8_2_1_analog_audio_ports">7.8.2.1. Analog Audio Ports</h4>
4103
4104
4105<p>In order to be compatible with the headsets and other audio accessories using
4106the 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
4107one of the audio port(s) SHOULD be a 4 conductor 3.5mm audio jack. If a device
4108implementation has a 4 conductor 3.5mm audio jack, it:</p>
4109
4110<ul>
4111 <li>MUST support audio playback to stereo headphones and stereo headsets with a
4112microphone, and SHOULD support audio recording from stereo headsets with a
4113microphone.</li>
4114 <li>MUST support TRRS audio plugs with the CTIA pin-out order, and SHOULD support
4115audio plugs with the OMTP pin-out order.</li>
4116 <li>MUST support the detection of microphone on the plugged in audio accessory, if
4117the device implementation supports a microphone, and broadcast the
4118android.intent.action.HEADSET_PLUG with the extra value microphone set as 1.</li>
4119 <li>SHOULD support the detection and mapping to the keycodes for the following 3
4120ranges of equivalent impedance between the microphone and ground conductors on
4121the audio plug:
4122 <ul>
4123 <li><strong>70 ohm or less</strong>: KEYCODE_HEADSETHOOK</li>
Glenn Kasten54e6ac12015-08-12 09:07:12 -0700[diff] [blame]4124 <li><strong>210&#45;290 Ohm</strong>: KEYCODE_VOLUME_UP</li>
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]4125 <li><strong>360&#45;680 Ohm</strong>: KEYCODE_VOLUME_DOWN</li>
4126 </ul></li>
4127 <li>SHOULD support the detection and mapping to the keycode for the following range
4128of equivalent impedance between the microphone and ground conductors on the
4129audio plug:
4130 <ul>
4131 <li><strong>110&#45;180 Ohm: </strong>KEYCODE_VOICE_ASSIST</li>
4132 </ul></li>
4133 <li>MUST trigger ACTION_HEADSET_PLUG upon a plug insert, but only after all
4134contacts on plug are touching their relevant segments on the jack.</li>
4135 <li>MUST be capable of driving at least 150mV +/- 10% of output voltage on a 32 Ohm
4136speaker impedance.</li>
4137 <li>MUST have a microphone bias voltage between 1.8V ~ 2.9V.</li>
4138</ul>
4139
Glenn Kasten20cdbb72015-09-24 11:56:42 -0700[diff] [blame]4140<h3 id="7_8_3_near_ultrasound">7.8.3. Near-Ultrasound </h3>
4141
4142<p>Near-Ultrasound audio is the 18.5 kHz to 20 kHz band.
4143Device implementations MUST correctly report the support
4144of near-ultrasound audio capability via the
4145<a href="http://developer.android.com/reference/android/media/AudioManager.html#getProperty(java.lang.String)">AudioManager.getProperty</a>
4146API as follows:
4147</p>
4148
4149<ul>
4150 <li>If
4151 <a href="http://developer.android.com/reference/android/media/AudioManager.html#PROPERTY_SUPPORT_MIC_NEAR_ULTRASOUND">PROPERTY_SUPPORT_MIC_NEAR_ULTRASOUND</a>
4152 is "true", then
4153 <ul>
4154 <li>The microphone's mean power response in the 18.5 kHz to 20 kHz band MUST be no more than
4155 15 dB below the response at 2 kHz.</li>
4156 <li>The signal to noise ratio of the microphone MUST be no lower than 80 dB.</li>
4157 </ul>
4158 </li>
4159 <li>If
4160 <a href="http://developer.android.com/reference/android/media/AudioManager.html#PROPERTY_SUPPORT_SPEAKER_NEAR_ULTRASOUND">PROPERTY_SUPPORT_SPEAKER_NEAR_ULTRASOUND</a>
4161 is "true", then the speaker's mean response in 18.5 kHz - 20 kHz MUST be no lower than 40 dB
4162 below the response at 2 kHz.
4163 </li>
4164</ul>
4165
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]4166<h1 id="8_performance_compatibility">8. Performance Compatibility</h1>
4167
4168
4169<p>Some minimum performance criterias are critical to the user experience and
4170impacts the baseline assumptions developers would have when developing an app.
4171Android Watch devices SHOULD and other type of device implementations MUST meet
4172the following criteria:</p>
4173
4174<h2 id="8_1_user_experience_consistency">8.1. User Experience Consistency</h2>
4175
4176
4177<p>Device implementations MUST provide a smooth user interface by ensuring a
4178consistent frame rate and response times for applications and games. Device
4179implementations MUST meet the following requirements: </p>
4180
4181<ul>
4182 <li><strong>Consistent frame latency</strong>. Inconsistent frame latency or a delay to render frames MUST NOT happen more
4183often than 5 frames in a second, and SHOULD be below 1 frames in a second.</li>
4184 <li><strong>User interface latency</strong>. Device implementations MUST ensure low latency user experience by scrolling a
4185list of 10K list entries as defined by the Android Compatibility Test Suite
4186(CTS) in less than 36 secs.</li>
4187 <li><strong>Task switching</strong>. When multiple applications have been launched, re-launching an already-running
4188application after it has been launched MUST take less than 1 second.</li>
4189</ul>
4190
4191<h2 id="8_2_file_i_o_access_performance">8.2. File I/O Access Performance</h2>
4192
4193
4194<p>Device implementations MUST ensure internal storage file access performance consistency for read
4195and write operations. </p>
4196
4197<ul>
4198 <li><strong>Sequential write</strong>. Device implementations MUST ensure a sequential write performance of at least 5MB/s
4199for a 256MB file using 10MB write buffer.</li>
4200 <li><strong>Random write</strong>. Device implementations MUST ensure a random write performance of at least 0.5MB/s for a
4201256MB file using 4KB write buffer.</li>
4202 <li><strong>Sequential read</strong>. Device implementations MUST ensure a sequential read performance of at least 15MB/s for
4203a 256MB file using 10MB write buffer.</li>
4204 <li><strong>Random read</strong>. Device implementations MUST ensure a random read performance of at least 3.5MB/s for a
4205256MB file using 4KB write buffer.</li>
4206</ul>
4207
4208<h1 id="9_security_model_compatibility">9. Security Model Compatibility</h1>
4209
4210
4211<p>Device implementations MUST implement a security model consistent with the
4212Android platform security model as defined in Security and Permissions
4213reference 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
4214installation of self-signed applications without requiring any additional
4215permissions/certificates from any third parties/authorities. Specifically,
4216compatible devices MUST support the security mechanisms described in the follow
4217subsections.</p>
4218
4219<h2 id="9_1_permissions">9.1. Permissions</h2>
4220
4221
4222<p>Device implementations MUST support the Android permissions model as defined in
4223the 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
4224described in the SDK documentation; no permissions may be omitted, altered, or
4225ignored. Implementations MAY add additional permissions, provided the new
4226permission ID strings are not in the android.* namespace.</p>
4227
Svetoslav4bbf7402015-09-11 14:45:48 -0700[diff] [blame]4228<p>Permissions with a protection level of dangerous are runtime permissions. Applications
4229with targetSdkVersion > 22 request them at runtime. The system MUST show a dedicated UI for the
4230user to decide whether to grant the requested runtime permissions and also provide a UI for the
4231user to manage runtime permissions. On the system there MUST be one and only one
4232implementation of both the UI for the user to accept runtime permissions and the UI for
4233the user to manage runtime permissions.</p>
4234
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]4235<h2 id="9_2_uid_and_process_isolation">9.2. UID and Process Isolation</h2>
4236
4237
4238<p>Device implementations MUST support the Android application sandbox model, in
4239which each application runs as a unique Unixstyle UID and in a separate
4240process. Device implementations MUST support running multiple applications as
4241the same Linux user ID, provided that the applications are properly signed and
4242constructed, as defined in the Security and Permissions reference [<a href="http://developer.android.com/guide/topics/security/permissions.html">Resources, 102</a>].</p>
4243
4244<h2 id="9_3_filesystem_permissions">9.3. Filesystem Permissions</h2>
4245
4246
4247<p>Device implementations MUST support the Android file access permissions model
4248as defined in the Security and Permissions reference [<a href="http://developer.android.com/guide/topics/security/permissions.html">Resources, 102</a>].</p>
4249
4250<h2 id="9_4_alternate_execution_environments">9.4. Alternate Execution Environments</h2>
4251
4252
4253<p>Device implementations MAY include runtime environments that execute
4254applications using some other software or technology than the Dalvik Executable
4255Format or native code. However, such alternate execution environments MUST NOT
4256compromise the Android security model or the security of installed Android
4257applications, as described in this section.</p>
4258
4259<p>Alternate runtimes MUST themselves be Android applications, and abide by the
4260standard Android security model, as described elsewhere in <a href="#9_security_model_compatibility">section 9</a>.</p>
4261
4262<p>Alternate runtimes MUST NOT be granted access to resources protected by
4263permissions not requested in the runtime&rsquo;s AndroidManifest.xml file via the
Unsuk Jung2e62f9a2015-07-16 23:01:44 -0700[diff] [blame]4264&lt;uses-permission&gt; mechanism.</p>
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]4265
4266<p>Alternate runtimes MUST NOT permit applications to make use of features
4267protected by Android permissions restricted to system applications.</p>
4268
4269<p>Alternate runtimes MUST abide by the Android sandbox model. Specifically,
4270alternate runtimes:</p>
4271
4272<ul>
4273 <li>SHOULD install apps via the PackageManager into separate Android sandboxes (
4274Linux user IDs, etc.).</li>
4275 <li>MAY provide a single Android sandbox shared by all applications using the
4276alternate runtime.</li>
4277 <li>and installed applications using an alternate runtime, MUST NOT reuse the
4278sandbox of any other app installed on the device, except through the standard
4279Android mechanisms of shared user ID and signing certificate.</li>
4280 <li>MUST NOT launch with, grant, or be granted access to the sandboxes
4281corresponding to other Android applications.</li>
4282 <li>MUST NOT be launched with, be granted, or grant to other applications any
4283privileges of the superuser (root), or of any other user ID.</li>
4284</ul>
4285
4286<p>The .apk files of alternate runtimes MAY be included in the system image of a
4287device implementation, but MUST be signed with a key distinct from the key used
4288to sign other applications included with the device implementation.</p>
4289
4290<p>When installing applications, alternate runtimes MUST obtain user consent for
4291the Android permissions used by the application. If an application needs to
4292make use of a device resource for which there is a corresponding Android
4293permission (such as Camera, GPS, etc.), the alternate runtime MUST inform the
4294user that the application will be able to access that resource. If the runtime
4295environment does not record application capabilities in this manner, the
4296runtime environment MUST list all permissions held by the runtime itself when
4297installing any application using that runtime.</p>
4298
4299<h2 id="9_5_multi-user_support">9.5. Multi-User Support</h2>
4300
4301<div class="note">
4302<p>This feature is optional for all device types.</p>
4303</div>
4304
4305
4306<p>Android includes support for multiple users and provides support for full user
4307isolation [<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
4308the following requirements related to multi-user support [<a href="http://source.android.com/devices/storage/">Resources, 104</a>]:</p>
4309
4310<ul>
4311 <li>Device implementations that do not declare the android.hardware.telephony
4312feature flag MUST support restricted profiles, a feature that allows device
4313owners to manage additional users and their capabilities on the device. With
4314restricted profiles, device owners can quickly set up separate environments for
4315additional users to work in, with the ability to manage finer-grained
4316restrictions in the apps that are available in those environments.</li>
4317 <li>Conversely device implementations that declare the android.hardware.telephony
4318feature flag MUST NOT support restricted profiles but MUST align with the AOSP
4319implementation of controls to enable /disable other users from accessing the
4320voice calls and SMS.</li>
4321 <li>Device implementations MUST, for each user, implement a security model
4322consistent with the Android platform security model as defined in Security and
4323Permissions reference document in the APIs [<a href="http://developer.android.com/guide/topics/security/permissions.html">Resources, 102</a>].</li>
4324 <li>Device implementations MAY support creating users and managed profiles via the
4325android.app.admin.DevicePolicyManager APIs, and if supported, MUST declare the
4326platform feature flag android.software.managed_users.
4327 <li>Device implementations that declare the feature flag
4328android.software.managed_users MUST use the upstream AOSP icon badge to
Glenn Kasten54e6ac12015-08-12 09:07:12 -0700[diff] [blame]4329represent the managed applications and other badge UI elements like Recents &amp;
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]4330Notifications.</li>
4331 <li>Each user instance on an Android device MUST have separate and isolated
4332external storage directories. Device implementations MAY store multiple users'
4333data on the same volume or filesystem. However, the device implementation MUST
4334ensure that applications owned by and running on behalf a given user cannot
4335list, read, or write to data owned by any other user. Note that removable
4336media, such as SD card slots, can allow one user to access another&rsquo;s data by
4337means of a host PC. For this reason, device implementations that use removable
4338media for the external storage APIs MUST encrypt the contents of the SD card if
4339multiuser is enabled using a key stored only on non-removable media accessible
4340only to the system. As this will make the media unreadable by a host PC, device
4341implementations will be required to switch to MTP or a similar system to
4342provide host PCs with access to the current user&rsquo;s data. Accordingly, device
4343implementations MAY but SHOULD NOT enable multi-user if they use removable
4344media [<a href="http://developer.android.com/reference/android/os/Environment.html">Resources, 105</a>] for primary external storage.</li>
4345</ul>
4346
4347<h2 id="9_6_premium_sms_warning">9.6. Premium SMS Warning</h2>
4348
4349
4350<p>Android includes support for warning users of any outgoing premium SMS message
4351[<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
4352carrier that may incur a charge to the user. Device implementations that
4353declare support for android.hardware.telephony MUST warn users before sending a
4354SMS message to numbers identified by regular expressions defined in
4355/data/misc/sms/codes.xml file in the device. The upstream Android Open Source
4356Project provides an implementation that satisfies this requirement.</p>
4357
4358<h2 id="9_7_kernel_security_features">9.7. Kernel Security Features</h2>
4359
4360
4361<p>The Android Sandbox includes features that can use the Security-Enhanced Linux
4362(SELinux) mandatory access control (MAC) system and other security features in
4363the Linux kernel. SELinux or any other security features, if implemented below
4364the Android framework:</p>
4365
4366<ul>
4367 <li>MUST maintain compatibility with existing applications.</li>
4368 <li>MUST NOT have a visible user interface when a security violation is detected
4369and successfully blocked, but MAY have a visible user interface when an
4370unblocked security violation occurs resulting in a successful exploit.</li>
4371 <li>SHOULD NOT be user or developer configurable.</li>
4372</ul>
4373
4374<p>If any API for configuration of policy is exposed to an application that can
4375affect another application (such as a Device Administration API), the API MUST
4376NOT allow configurations that break compatibility.</p>
4377
4378<p>Devices MUST implement SELinux or an equivalent mandatory access control system
4379if using a kernel other than Linux and meet the following requirements, which
4380are satisfied by the reference implementation in the upstream Android Open
4381Source Project.</p>
4382
4383<p>Device implementations:</p>
4384
4385<ul>
4386 <li>MUST support a SELinux policy that allows the SELinux mode to be set on a
4387per-domain basis, and MUST configure all domains in enforcing mode. No
4388permissive mode domains are allowed, including domains specific to a
4389device/vendor.</li>
4390 <li>SHOULD load policy from /sepolicy file on the device.</li>
4391 <li>MUST NOT modify, omit, or replace the neverallow rules present within the
4392sepolicy file provided in the upstream Android Open Source Project (AOSP) and
4393the policy MUST compile with all neverallow present, for both AOSP SELinux
4394domains as well as device/vendor specific domains.</li>
4395 <li>MUST support dynamic updates of the SELinux policy file without requiring a
4396system image update.</li>
4397</ul>
4398
4399<p>Device implementations SHOULD retain the default SELinux policy provided in the
4400upstream Android Open Source Project, until they have first audited their
4401additions to the SELinux policy. Device implementations MUST be compatible with
4402the upstream Android Open Source Project.</p>
4403
4404<h2 id="9_8_privacy">9.8. Privacy</h2>
4405
4406<p>If the device implements functionality in the system that captures the contents
4407displayed on the screen and/or records the audio stream played on the device,
4408it MUST continuously notify the user whenever this functionality is enabled and
4409actively capturing/recording.</p>
4410
4411<p>If a device implementation has a mechanism that routes network data traffic
4412through a proxy server or VPN gateway by default (for example, preloading a VPN
4413service with android.permission.CONTROL_VPN granted), the device implementation
4414MUST ask for the user's consent before enabling that mechanism.</p>
4415
Unsuk Jungaad25192015-09-29 11:55:45 -0700[diff] [blame]4416<p>If a device implementation has a USB port with USB peripheral mode support,
4417it MUST present a user interface asking for the user's consent before allowing
4418access to the contents of the shared storage over the USB port.</p>
4419
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]4420<h2 id="9_9_full-disk_encryption">9.9. Full-Disk Encryption</h2>
4421
4422<div class="note">
4423<p>Optional for Android device implementations without a lock screen.</p>
4424</div>
4425
4426
4427<p>If the device implementation supports a lock screen with PIN (numeric) or
4428PASSWORD (alphanumeric), the device MUST support full-disk encryption of the
4429application private data (/data partition), as well
4430as the SD card partition if it is a permanent, non-removable part of the device
4431[<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
4432be enabled all the time after the user has completed the out-of-box experience.
4433While this requirement is stated as SHOULD for this version of the Android
4434platform, it is <strong>very strongly RECOMMENDED</strong> as we expect this to change to MUST in the future versions of Android.
4435Encryption MUST use AES with a key of 128-bits (or greater) and a mode designed
4436for storage (for example, AES-XTS, AES-CBC-ESSIV). The encryption key MUST NOT
4437be written to storage at any time without being encrypted. Other than when in
4438active use, the encryption key SHOULD be AES encrypted with the lockscreen
4439passcode stretched using a slow stretching algorithm (e.g. PBKDF2 or scrypt).
4440If the user has not specified a lockscreen passcode or has disabled use of the
4441passcode for encryption, the system SHOULD use a default passcode to wrap the
4442encryption key. If the device provides a hardware-backed keystore, the password
4443stretching algorithm MUST be cryptographically bound to that keystore. The
4444encryption key MUST NOT be sent off the device (even when wrapped with the user
4445passcode and/or hardware bound key). The upstream Android Open Source project
Clay Murphyf4fa6bc2015-08-28 17:20:31 -0700[diff] [blame]4446provides a preferred implementation of this feature based on the Linux kernel
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]4447feature dm-crypt.</p>
4448
4449<h2 id="9_10_verified_boot">9.10. Verified Boot</h2>
4450
4451<p>
4452Verified boot is a feature that guarantees the integrity of the device software.
4453If a device implementation supports the feature, it MUST:
Glenn Kasten54e6ac12015-08-12 09:07:12 -0700[diff] [blame]4454</p>
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]4455<ul>
4456<li>Declare the platform feature flag android.software.verified_boot</li>
4457<li>Perform verification on every boot sequence</li>
Clay Murphyf4fa6bc2015-08-28 17:20:31 -0700[diff] [blame]4458<li>Start verification from an immutable hardware key that is the root of trust,
4459and go all the way up to the system partition</li>
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]4460<li>Implement each stage of verification to check the integrity and authenticity
4461of all the bytes in the next stage before executing the code in the next stage</li>
4462<li>Use verification algorithms as strong as current recommendations
4463from NIST for hashing algorithms (SHA-256) and public key sizes (RSA-2048)</li>
4464</ul>
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]4465
Clay Murphyf4fa6bc2015-08-28 17:20:31 -0700[diff] [blame]4466<p>The upstream Android Open Source Project provides a preferred implementation of this
4467feature based on the Linux kernel feature dm-verity.</p>
4468
4469<p>Starting from Android 6.0, device implementations with Advanced Encryption Standard (AES)
4470crypto perfomance above 50MiB/seconds MUST support verified boot for device integrity.
4471If a device implementation is already launched without supporting verified boot on an earlier
4472version of Android, such a device can not add support for this feature with a system software
4473update and thus are exempted from the requirement.</p>
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]4474
4475<h1 id="10_software_compatibility_testing">10. Software Compatibility Testing</h1>
4476
4477
4478<p>Device implementations MUST pass all tests described in this section.</p>
4479
4480<p>However, note that no software test package is fully comprehensive. For this
Bert McMeen816a2422015-09-29 16:33:19 -0700[diff] [blame]4481reason, device implementers are <strong>STRONGLY RECOMMENDED</strong> to make the minimum number of changes as possible to the reference and
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]4482preferred implementation of Android available from the Android Open Source
4483Project. This will minimize the risk of introducing bugs that create
4484incompatibilities requiring rework and potential device updates.</p>
4485
4486<h2 id="10_1_compatibility_test_suite">10.1. Compatibility Test Suite</h2>
4487
4488
4489<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
4490software on the device. Additionally, device implementers SHOULD use the
4491reference implementation in the Android Open Source tree as much as possible,
4492and MUST ensure compatibility in cases of ambiguity in CTS and for any
4493reimplementations of parts of the reference source code.</p>
4494
4495<p>The CTS is designed to be run on an actual device. Like any software, the CTS
4496may itself contain bugs. The CTS will be versioned independently of this
4497Compatibility Definition, and multiple revisions of the CTS may be released for
4498Android ANDROID_VERSION. Device implementations MUST pass the latest CTS version available
4499at the time the device software is completed.</p>
4500
4501<h2 id="10_2_cts_verifier">10.2. CTS Verifier</h2>
4502
4503
4504<p>Device implementations MUST correctly execute all applicable cases in the CTS
4505Verifier. The CTS Verifier is included with the Compatibility Test Suite, and
4506is intended to be run by a human operator to test functionality that cannot be
4507tested by an automated system, such as correct functioning of a camera and
4508sensors.</p>
4509
4510<p>The CTS Verifier has tests for many kinds of hardware, including some hardware
4511that is optional. Device implementations MUST pass all tests for hardware that
4512they possess; for instance, if a device possesses an accelerometer, it MUST
4513correctly execute the Accelerometer test case in the CTS Verifier. Test cases
4514for features noted as optional by this Compatibility Definition Document MAY be
4515skipped or omitted.</p>
4516
4517<p>Every device and every build MUST correctly run the CTS Verifier, as noted
4518above. However, since many builds are very similar, device implementers are not
4519expected to explicitly run the CTS Verifier on builds that differ only in
4520trivial ways. Specifically, device implementations that differ from an
4521implementation that has passed the CTS Verifier only by the set of included
4522locales, branding, etc. MAY omit the CTS Verifier test.</p>
4523
4524<h1 id="11_updatable_software">11. Updatable Software</h1>
4525
4526
4527<p>Device implementations MUST include a mechanism to replace the entirety of the
4528system software. The mechanism need not perform &ldquo;live&rdquo; upgrades&mdash;that is, a
4529device restart MAY be required.</p>
4530
4531<p>Any method can be used, provided that it can replace the entirety of the
4532software preinstalled on the device. For instance, any of the following
4533approaches will satisfy this requirement:</p>
4534
4535<ul>
4536 <li>&ldquo;Over-the-air (OTA)&rdquo; downloads with offline update via reboot</li>
4537 <li>&ldquo;Tethered&rdquo; updates over USB from a host PC</li>
4538 <li>&ldquo;Offline&rdquo; updates via a reboot and update from a file on removable storage</li>
4539</ul>
4540
4541<p>However, if the device implementation includes support for an unmetered data
4542connection such as 802.11 or Bluetooth PAN (Personal Area Network) profile:</p>
4543
4544<ul>
4545<li>Android Automotive implementations SHOULD support OTA downloads with offline
4546update via reboot.</li>
4547<li>All other device implementations MUST support OTA downloads with offline
4548update via reboot.</li>
4549</ul>
4550
4551<p>The update mechanism used MUST support updates without wiping user data. That
4552is, the update mechanism MUST preserve application private data and application
4553shared data. Note that the upstream Android software includes an update
4554mechanism that satisfies this requirement.</p>
4555
4556<p>For device implementations that are launching with Android ANDROID_VERSION and later, the
4557update mechanism SHOULD support verifying that the system image is binary
4558identical to expected result following an OTA. The block-based OTA
4559implementation in the upstream Android Open Source Project, added since Android
45605.1, satisfies this requirement.</p>
4561
4562<p>If an error is found in a device implementation after it has been released but
4563within its reasonable product lifetime that is determined in consultation with
4564the Android Compatibility Team to affect the compatibility of third-party
4565applications, the device implementer MUST correct the error via a software
4566update available that can be applied per the mechanism just described.</p>
4567
4568<h1 id="12_document_changelog">12. Document Changelog</h1>
4569
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]4570<p>The following table contains a summary of the changes to the Compatibility
4571Definition in this release. </p>
4572<table>
4573 <tr>
4574 <th>Section</th>
4575 <th>Summary of change</th>
4576 </tr>
4577 <tr>
Bert McMeen15ecb402015-10-01 13:17:55 -0700[diff] [blame]4578 <td>text</td>
4579 <td>text</td>
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]4580 </tr>
Bert McMeen15ecb402015-10-01 13:17:55 -0700[diff] [blame]4581 </table>
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]4582
4583
4584<h1 id="13_contact_us">13. Contact Us</h1>
4585
4586
4587<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
4588does not cover.</p>
4589
4590<h1 id="14_resources">14. Resources</h1>
4591
4592
4593<p>1. IETF RFC2119 Requirement Levels: <a href="http://www.ietf.org/rfc/rfc2119.txt">http://www.ietf.org/rfc/rfc2119.txt</a></p>
4594
4595<p>2. Android Open Source Project: <a href="http://source.android.com/">http://source.android.com/</a></p>
4596
4597<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>
4598
4599<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>
4600
4601<p>5. API definitions and documentation: <a href="http://developer.android.com/reference/packages.html">http://developer.android.com/reference/packages.html</a></p>
4602
4603<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>
4604
4605<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>
4606
4607<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>
4608
4609<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>
4610
4611<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>
4612
4613<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>
4614
4615<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>
4616
4617<p>13. WebView compatibility: <a href="http://www.chromium.org/">http://www.chromium.org/</a></p>
4618
4619<p>14. HTML5: <a href="http://html.spec.whatwg.org/multipage/">http://html.spec.whatwg.org/multipage/</a></p>
4620
4621<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>
4622
4623<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>
4624
4625<p>17. HTML5/W3C geolocation API: <a href="http://www.w3.org/TR/geolocation-API/">http://www.w3.org/TR/geolocation-API/</a></p>
4626
4627<p>18. HTML5/W3C webstorage API: <a href="http://www.w3.org/TR/webstorage/">http://www.w3.org/TR/webstorage/</a></p>
4628
4629<p>19. HTML5/W3C IndexedDB API: <a href="http://www.w3.org/TR/IndexedDB/">http://www.w3.org/TR/IndexedDB/</a></p>
4630
4631<p>20. Dalvik Executable Format and bytecode specification: available in the
4632Android source code, at dalvik/docs</p>
4633
4634<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>
4635
4636<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>
4637
4638<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>
4639
4640<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>
4641
4642<p>25. Notifications Resources: <a href="https://developer.android.com/design/patterns/notifications.html">https://developer.android.com/design/patterns/notifications.html</a> </p>
4643
4644<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>
4645
4646<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>
4647
4648<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>
4649
4650<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>
4651
4652<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>
4653
4654<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>
4655
4656<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>
4657
4658<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>
4659
4660<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>
4661
4662<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>
4663
4664<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>
4665
4666<p>37. Settings.Secure LOCATION_MODE:</p>
4667
4668<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>
4669
4670<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>
4671
4672<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>
4673
4674<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>
4675
4676<p>41. Android Device Owner App:</p>
4677
4678<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>
Andy Dyer-smith3d24bbe2015-09-11 15:35:23 +0100[diff] [blame]4679<p>XX. Android Device Owner Provisioning Flow:</p>
4680
4681<p><a href="http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html#ACTION_PROVISION_MANAGED_DEVICE">http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html#ACTION_PROVISION_MANAGED_DEVICE</a></p>
4682<p>XX. Device Owner Provisioning via NFC:</p>
4683
4684<p><a href="https://source.android.com/devices/tech/admin/provision.html#device_owner_provisioning_via_nfc">https://source.android.com/devices/tech/admin/provision.html#device_owner_provisioning_via_nfc</a></p>
4685<p>XX. Android Managed Profile Provisioning flow:</p>
4686
4687<p><a href="http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html#ACTION_PROVISION_MANAGED_PROFILE">http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html#ACTION_PROVISION_MANAGED_PROFILE</a></p>
4688
4689<p>XX. Android Profile Owner App:</p>
4690
4691<p><a href="http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html#isProfileOwnerApp(java.lang.String)">http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html#isProfileOwnerApp(java.lang.String)</a></p>
Unsuk Jung5bc81142015-07-16 22:27:20 -0700[diff] [blame]4692
4693<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>
4694
4695<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>
4696
4697<p>44. Eyes Free project: <a href="http://code.google.com/p/eyes-free/">http://code.google.com/p/eyes-free</a></p>
4698
4699<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>
4700
4701<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>
4702
4703<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>
4704
4705<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>
4706
4707<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>
4708
4709<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>
4710
4711<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>
4712
4713<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>
4714
4715<p>53. Android android.content.pm.PackageManager class and Hardware Features List:</p>
4716
4717<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>
4718
4719<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>
4720
4721<p>55. ADB: <a href="http://developer.android.com/tools/help/adb.html">http://developer.android.com/tools/help/adb.html</a> </p>
4722
4723<p>56. Dumpsys: <a href="https://source.android.com/devices/input/diagnostics.html">https://source.android.com/devices/input/diagnostics.html</a> </p>
4724
4725<p>57. DDMS: <a href="http://developer.android.com/tools/debugging/ddms.html">http://developer.android.com/tools/debugging/ddms.html</a> </p>
4726
4727<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>
4728
4729<p>59. SysyTrace tool: <a href="http://developer.android.com/tools/help/systrace.html">http://developer.android.com/tools/help/systrace.html</a></p>
4730
4731<p>60. Android Application Development-Related Settings:</p>
4732
4733<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>
4734
4735<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>
4736
4737<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>
4738
4739<p>63. RenderScript: <a href="http://developer.android.com/guide/topics/renderscript/">http://developer.android.com/guide/topics/renderscript/</a></p>
4740
4741<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>
4742
4743<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>
4744
4745<p>66. EGL Extension-EGL_ANDROID_RECORDABLE:</p>
4746
4747<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>
4748
4749<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>
4750
4751<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>
4752
4753<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>
4754
4755<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>
4756
4757<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>
4758
4759<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>
4760
4761<p>73. Android Open Source sensors: <a href="http://source.android.com/devices/sensors/">http://source.android.com/devices/sensors</a></p>
4762
4763<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>
4764
4765<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>
4766
4767<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>
4768
4769<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>
4770
4771<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>
4772
4773<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>
4774
4775<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>
4776
4777<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>
4778
4779<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>
4780
4781<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>
4782
4783<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>
4784
4785<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>
4786
4787<p>86. Android NFC Sharing Settings:</p>
4788
4789<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>
4790
4791<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>
4792
4793<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>
4794
4795<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>
4796
4797<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>
4798
4799<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>
4800
4801<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>
4802
4803<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>
4804
4805<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>
4806
4807<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>
4808
4809<p>96. Android File Transfer: <a href="http://www.android.com/filetransfer">http://www.android.com/filetransfer</a></p>
4810
4811<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>
4812
4813<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>
4814
4815<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>
4816
4817<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>
4818
4819<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>
4820
4821<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>
4822
4823<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>
4824
4825<p>104. External Storage reference: <a href="http://source.android.com/devices/storage">http://source.android.com/devices/storage</a></p>
4826
4827<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>
4828
4829<p>106. SMS Short Code: <a href="http://en.wikipedia.org/wiki/Short_code">http://en.wikipedia.org/wiki/Short_code</a></p>
4830
4831<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>
4832
4833<p>108. Android Compatibility Program Overview: <a href="http://source.android.com/compatibility/index.html">http://source.android.com/compatibility/index.html</a></p>
4834
4835<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>
4836
4837<p>110. WebM project: <a href="http://www.webmproject.org/">http://www.webmproject.org/</a> </p>
4838
4839<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>
4840
4841<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>
4842
4843<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>
4844
4845<p>Many of these resources are derived directly or indirectly from the Android
4846SDK, and will be functionally identical to the information in that SDK&rsquo;s
4847documentation. In any cases where this Compatibility Definition or the
4848Compatibility Test Suite disagrees with the SDK documentation, the SDK
4849documentation is considered authoritative. Any technical details provided in
4850the references included above are considered by inclusion to be part of this
4851Compatibility Definition.</p>
4852
4853</div>
4854</body>
4855</html>