1 lpage.title=Camera Version Support 2 @jd:body 3 4 <!-- 5 Copyright 2016 The Android Open Source Project 6 7 Licensed under the Apache License, Version 2.0 (the "License"); 8 you may not use this file except in compliance with the License. 9 You may obtain a copy of the License at 10 11 http://www.apache.org/licenses/LICENSE-2.0 12 13 Unless required by applicable law or agreed to in writing, software 14 distributed under the License is distributed on an "AS IS" BASIS, 15 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 16 See the License for the specific language governing permissions and 17 limitations under the License. 18 --> 19 <div id="qv-wrapper"> 20 <div id="qv"> 21 <h2>In this document</h2> 22 <ol id="auto-toc"> 23 </ol> 24 </div> 25 </div> 26 27 <p>This page details version differences in Camera HALs, APIs, and associated 28 Android Compatibility Test Suite (CTS) tests. It also covers several 29 architectural changes made to harden and secure the camera framework in Android 30 7.0 and the updates vendors must make to support these changes in their camera 31 implementations.</p> 32 33 <h2 id=glossary>Terminology</h2> 34 35 <p>The following terms are used on this page:</p> 36 37 <dl> 38 39 <dt>Camera API1</dt> 40 <dd>The app-level camera framework on Android 4.4 and earlier devices, exposed 41 through the <code>android.hardware.Camera</code> class.</dd> 42 43 <dt>Camera API2</dt> 44 <dd>The app-level camera framework on Android 5.0 and later devices, exposed 45 through the<code> android.hardware.camera2</code> package.</dd> 46 47 <dt>Camera HAL</dt> 48 <dd>The camera module layer implemented by SoC vendors. The app-level public 49 frameworks are built on top of the camera HAL.</dd> 50 51 <dt>Camera HAL3.1</dt> 52 <dd>Version of the camera device HAL released with Android 4.4.</dd> 53 54 <dt>Camera HAL3.2</dt> 55 <dd>Version of the camera device HAL released with Android 5.0.</dd> 56 57 <dt>Camera API1 CTS</dt> 58 <dd>Set of camera Compatibility Test Suite (CTS) tests that run on top of Camera 59 API1.</dd> 60 61 <dt>Camera API2 CTS</dt> 62 <dd>Additional set of camera CTS tests that run on top of Camera API2.</dd> 63 64 </dl> 65 66 67 <h2 id=camera_apis>Camera APIs</h2> 68 <p>Android includes the following camera APIs.</p> 69 70 <h3 id=camera_api1>Camera API1</h3> 71 72 <p>Android 5.0 deprecated Camera API1, which continues to be phased out as new 73 platform development focuses on Camera API2. However, the phase-out period will 74 be lengthy, and Android releases will continue to support Camera API1 apps for 75 some time. Specifically, support continues for:</p> 76 77 <ul> 78 <li><em>Camera API1 interfaces for apps</em>. Camera apps built on top of Camera 79 API1 should work as they do on devices running earlier Android release versions. 80 </li> 81 <li><em>Camera HAL versions</em>. Includes support for Camera HAL1.0.</li> 82 </ul> 83 84 <h3 id=camera_api2>Camera API2</h3> 85 86 <p>The Camera API2 framework exposes lower-level camera control to the app, 87 including efficient zero-copy burst/streaming flows and per-frame controls of 88 exposure, gain, white balance gains, color conversion, denoising, sharpening, 89 and more. For details, watch the 90 <a href="https://www.youtube.com/watch?v=92fgcUNCHic&feature=youtu.be&t=29m50s">Google 91 I/O video overview</a>.</p> 92 93 <p>Android 5.0 and later includes Camera API2; however, devices running Android 94 5.0 and later may not support all Camera API2 features. The 95 <code>android.info.supportedHardwareLevel</code> property that apps can query 96 through the Camera API2 interfaces reports one of the following support 97 levels:</p> 98 99 <ul> 100 <li><code>LEGACY</code>. These devices expose capabilities to apps through the 101 Camera API2 interfaces that are approximately the same capabilities as those 102 exposed to apps through the Camera API1 interfaces. The legacy frameworks code 103 conceptually translates Camera API2 calls into Camera API1 calls; legacy devices 104 do not support Camera API2 features such as per-frame controls.</li> 105 <li><code>FULL</code>. These devices support all of major capabilities of Camera 106 API2 and must use Camera HAL 3.2 or later and Android 5.0 or later.</li> 107 <li><code>LIMITED</code>. These devices support some Camera API2 capabilities 108 (but not all) and must use Camera HAL 3.2 or later.</li> 109 </ul> 110 111 <p>Individual capabilities are exposed via the 112 <code>android.request.availableCapabilities</code> property in the Camera API2 113 interfaces. <code>FULL</code> devices require the <code>MANUAL_SENSOR</code> and 114 <code>MANUAL_POST_PROCESSING</code> capabilities, among others. The 115 <code>RAW</code> capability is optional even for <code>FULL</code> devices. 116 <code>LIMITED</code> devices can advertise any subset of these capabilities, 117 including none of them. However, the <code>BACKWARD_COMPATIBLE</code> capability 118 must always be defined.</p> 119 120 <p>The supported hardware level of the device, as well as the specific Camera 121 API2 capabilities it supports, are available as the following feature flags to 122 allow Google Play filtering of Camera API2 camera apps.</p> 123 124 <ul> 125 <li><code>android.hardware.camera.hardware_level.full</code> 126 <li><code>android.hardware.camera.capability.raw</code> 127 <li><code>android.hardware.camera.capability.manual_sensor</code> 128 <li><code>android.hardware.camera.capability.manual_post_processing</code> 129 </ul> 130 131 <h2 id=cts_requirements>CTS requirements</h2> 132 133 <p>Devices running Android 5.0 and later must pass the Camera API1 CTS, Camera 134 API2 CTS, and CTS Verifier camera tests.</p> 135 136 <p>Devices that do not feature a Camera HAL3.2 implementation and are not 137 capable of supporting the full Camera API2 interfaces must still pass the Camera 138 API2 CTS tests. However, the device will be running in Camera API2 139 <code>LEGACY</code> mode (in which the Camera API2 calls are conceptually mapped 140 to Camera API1 calls) so any Camera API2 CTS tests related to features or 141 capabilities beyond Camera API1 will be automatically skipped.</p> 142 143 <p>On legacy devices, Camera API2 CTS tests that are not skipped use the 144 existing public Camera API1 interfaces and capabilities with no new 145 requirements. Bugs that are exposed (and which cause a Camera API2 CTS failure) 146 are bugs already present in the devices existing Camera HAL, and thus would 147 be found by existing Camera API1 apps. We do not expect many bugs of this nature 148 (however, any such bugs must be fixed to pass the Camera API2 CTS tests).</p> 149 150 <h2 id=hardening>Camera framework hardening</h2> 151 152 <p>To harden media and camera framework security, Android 7.0 moves camera 153 service out of mediaserver. Vendors may need to make changes in the camera HAL 154 depending on the API and HAL versions in use. The following sections detail 155 architectural changes in AP1 and AP2 for HAL1 and HAL3, as well as general 156 requirements.</p> 157 158 <h3 id=hardening_api1>Architectural changes for API1</h3> 159 <p>API1 video recording may assume camera and video encoder live in the same 160 process. When using API1 on:</p> 161 162 <ul> 163 <li>HAL3, where camera service uses BufferQueue to pass buffers between 164 processes, <strong>no vendor update</strong> is necessary. 165 <p><img src="images/ape_camera_n_api1_hal3.png" alt="Android 7.0 camera and media 166 stack in API1 on HAL3" id="figure1" /></p> 167 <p class="img-caption"><strong>Figure 1.</strong>Android 7.0 camera and media 168 stack in API1 on HAL3.</p> 169 </li> 170 <li>HAL1, which supports passing metadata in video buffers, <strong>vendors must 171 update the HAL to use kMetadataBufferTypeNativeHandleSource</strong>. 172 (<code>kMetadataBufferTypeCameraSource</code> is no longer supported in Android 173 7.0.) 174 <p><img src="images/ape_camera_n_api1_hal1.png" alt="Android 7.0 camera and media 175 stack in API1 on HAL1" id="figure1" /></p> 176 <p class="img-caption"><strong>Figure 2.</strong>Android 7.0 camera and media 177 stack in API1 on HAL1.</p> 178 </li> 179 </ul> 180 181 <h3 id=hardening_api2>Architectural changes for API2</h3> 182 <p>For API2 on HAL1 or HAL3, BufferQueue passes buffers so those paths continue 183 to work. The Android 7.0 architecture for API2 on:</p> 184 185 <ul> 186 <li>HAL1 is not affected by the cameraservice move, and <strong>no vendor 187 update</strong> is necessary.</li> 188 <li>HAL3 <em>is</em> affected, but <strong>no vendor update</strong> is 189 necessary: 190 <p><img src="images/ape_camera_n_api2_hal3.png" alt="Android 7.0 camera and 191 media stack in API2 on HAL2" id="figure1" /></p> 192 <p class="img-caption"><strong>Figure 3.</strong>Android 7.0 camera and media 193 stack in API2 on HAL3.</p> 194 </li> 195 </ul> 196 197 <h3 id=hardening_general>Additional requirements</h3> 198 <p>The architectural changes made for hardening media and camera framework 199 security include the following additional device requirements.</p> 200 201 <ul> 202 <li><strong>General</strong>. Devices require additional bandwidth due to IPC, 203 which may affect time-sensitive camera use cases such as high-speed video 204 recording. Vendors can measure actual impact by running 205 <code>android.hardware.camera2.cts.PerformanceTest</code> and the Google Camera 206 App for 120/240 FPS high speed video recording. Devices also require a small 207 amount of additional RAM to create the new process.</li> 208 <li><strong>Pass metadata in video buffers</strong>(<em>HAL1 only</em>). If HAL1 209 stores metadata instead of real YUV frame data in video buffers, the HAL must 210 use <code>kMetadataBufferTypeNativeHandleSource</code> as the metadata buffer 211 type and pass <code>VideoNativeHandleMetadata</code> in video buffers. 212 (<code>kMetadataBufferTypeCameraSource</code> is no longer supported on Android 213 7.0.) With <code>VideoNativeHandleMetadata</code>, camera and media frameworks 214 are able to pass the video buffers between processes by serializing and 215 deserializing the native handles properly.</li> 216 <li><strong>Buffer handle address does not always store the same buffer</strong> 217 (<em>HAL3 only</em>). For each capture request, HAL3 gets addresses of buffer 218 handles. HAL cannot use the addresses to identify buffers because the addresses 219 may store another buffer handle after HAL returns the buffer. You must update 220 the HAL to use buffer handles to identify the buffers. For example: HAL receives 221 a buffer handle address A, which stores buffer handle A. After HAL returns 222 buffer handle A, buffer handle address A may store buffer handle B next time the 223 HAL receives it.</li> 224 <li><strong>Update SELinux policies for cameraserver</strong>. If 225 device-specific SELinux policies give mediaserver permissions to run the camera, 226 you must update the SELinux policies to give cameraserver proper permissions. We 227 do not encourage replicating the mediaserver's SELinux policies for cameraserver 228 (as mediaserver and cameraserver generally require different resources in the 229 system). Cameraserver should have only the permissions needed to perform camera 230 functionalities and any unnecessary camera-related permissions in mediaserver 231 should be removed.</p> 232 233 <h3 id=hardening_validation>Validation</h3> 234 <p>For all devices that include a camera and run Android 7.0, verify the 235 implementation by running Android 7.0 CTS. Although Android 7.0 does not include 236 new CTS tests that verify camera service changes, existing CTS tests will fail 237 if you have not made the updates indicated above.</p> 238 239 <h2 id="version-history">Camera HAL version history</h2> 240 <p>For a list of tests available for evaluating the Android Camera HAL, see the 241 <a href="{@docRoot}compatibility/cts/camera-hal.html">Camera HAL Testing 242 Checklist</a>.</p> 243 244 <h3 id="34">3.4</h3> 245 246 <p>Minor additions to supported metadata and changes to data_space support:</p> 247 248 <ul> 249 <li>Add <code>ANDROID_SENSOR_OPAQUE_RAW_SIZE</code> static metadata as mandatory 250 if <code>RAW_OPAQUE</code> format is supported.</li> 251 <li>Add <code>ANDROID_CONTROL_POST_RAW_SENSITIVITY_BOOST_RANGE</code> static 252 metadata as mandatory if any RAW format is supported.</li> 253 <li>Switch <code>camera3_stream_t data_space</code> field to a more flexible 254 definition, using the version 0 definition of dataspace encoding.</li> 255 <li>General metadata additions which are available to use for HALv3.2 or newer: 256 <ul> 257 <li> 258 <a href="https://developer.android.com/reference/android/hardware/camera2/CameraMetadata.html#INFO_SUPPORTED_HARDWARE_LEVEL_3"><code>ANDROID_INFO_SUPPORTED_HARDWARE_LEVEL_3</code> 259 </a></li> 260 <li><code>ANDROID_CONTROL_POST_RAW_SENSITIVITY_BOOST</code></li> 261 <li><code>ANDROID_CONTROL_POST_RAW_SENSITIVITY_BOOST_RANGE</code></li> 262 <li><code>ANDROID_SENSOR_DYNAMIC_BLACK_LEVEL</code></li> 263 <li><code>ANDROID_SENSOR_DYNAMIC_WHITE_LEVEL</code></li> 264 <li><code>ANDROID_SENSOR_OPAQUE_RAW_SIZE</code></li> 265 <li><code>ANDROID_SENSOR_OPTICAL_BLACK_REGIONS</code></li> 266 </ul> 267 <li> 268 </ul> 269 270 <h3 id="33">3.3</h3> 271 272 <p>Minor revision of expanded-capability HAL:</p> 273 274 <ul> 275 <li>OPAQUE and YUV reprocessing API updates.</li> 276 <li>Basic support for depth output buffers.</li> 277 <li>Addition of <code>data_space</code> field to 278 <code>camera3_stream_t</code>.</li> 279 <li>Addition of rotation field to <code>camera3_stream_t</code>.</li> 280 <li>Addition of camera3 stream configuration operation mode to 281 <code>camera3_stream_configuration_t</code>.</li> 282 </ul> 283 284 <h3 id="32">3.2</h3> 285 286 <p>Minor revision of expanded-capability HAL:</p> 287 288 <ul> 289 <li>Deprecates <code>get_metadata_vendor_tag_ops</code>. Use 290 <code>get_vendor_tag_ops</code> in <code>camera_common.h</code> instead.</li> 291 <li>Deprecates <code>register_stream_buffers</code>. All gralloc buffers 292 provided by framework to HAL in <code>process_capture_request</code> may be new 293 at any time.</li> 294 <li>Add partial result support. <code>process_capture_result</code> may be 295 called multiple times with a subset of the available results before the full 296 result is available.</li> 297 <li>Add manual template to <code>camera3_request_template</code>. Applications 298 may use this template to control the capture settings directly.</li> 299 <li>Rework the bidirectional and input stream specifications.</li> 300 <li>Change the input buffer return path. The buffer is returned in 301 <code>process_capture_result</code> instead of 302 <code>process_capture_request</code>.</li> 303 </ul> 304 305 <h3 id="31">3.1</h3> 306 307 <p>Minor revision of expanded-capability HAL:</p> 308 309 <ul> 310 <li><code>configure_streams</code> passes consumer usage flags to the HAL.</li> 311 <li>flush call to drop all in-flight requests/buffers as fast as possible.</li> 312 </ul> 313 314 <h3 id="30">3.0</h3> 315 316 <p>First revision of expanded-capability HAL:</p> 317 318 <ul> 319 <li>Major version change since the ABI is completely different. No change to the 320 required hardware capabilities or operational model from 2.0.</li> 321 <li>Reworked input request and stream queue interfaces: Framework calls into HAL 322 with next request and stream buffers already dequeued. Sync framework support 323 is included, necessary for efficient implementations.</li> 324 <li>Moved triggers into requests, most notifications into results.</li> 325 <li>Consolidated all callbacks into framework into one structure, and all setup 326 methods into a single <code>initialize()</code> call.</li> 327 <li>Made stream configuration into a single call to simplify stream management. 328 Bidirectional streams replace STREAM_FROM_STREAM construct.</li> 329 <li>Limited mode semantics for older/limited hardware devices.</li> 330 </ul> 331 332 <h3 id="20">2.0</h3> 333 334 <p>Initial release of expanded-capability HAL (Android 4.2) [camera2.h]:</p> 335 336 <ul> 337 <li>Sufficient for implementing existing <code>android.hardware.Camera</code> 338 API.</li> 339 <li>Allows for ZSL queue in camera service layer.</li> 340 <li>Not tested for any new features such as manual capture control, Bayer RAW 341 capture, reprocessing of RAW data, etc.</li> 342 </ul> 343 344 <h3 id="10">1.0</strong></h3> 345 346 <p>Initial Android camera HAL (Android 4.0) [camera.h]:</p> 347 348 <ul> 349 <li>Converted from C++ CameraHardwareInterface abstraction layer.</li> 350 <li>Supports <code>android.hardware.Camera</code> API.</li> 351 </ul> 352 353 <h2 id=module_version>Camera module version history</h2> 354 355 <p>This section contains module versioning information for the Camera hardware 356 module, based on <code>camera_module_t.common.module_api_version</code>. The two 357 most significant hex digits represent the major version, and the two least 358 significant represent the minor version.</p> 359 360 <h3 id="24">2_4</h3> 361 362 <p>This camera module version adds the following API changes:</p> 363 364 <ol> 365 <li><em>Torch mode support</em>. The framework can turn on torch mode for any 366 camera device that has a flash unit, without opening a camera device. The 367 camera device has a higher priority accessing the flash unit than the camera 368 module; opening a camera device will turn off the torch if it had been enabled 369 through the module interface. When there are any resource conflicts, such as 370 <code>open()</code> is called to open a camera device, the camera HAL module 371 must notify the framework through the torch mode status callback that the torch 372 mode has been turned off.</li> 373 374 <li><em>External camera (e.g. USB hot-plug camera) support</em>. The API 375 updates specify the camera static info is available only when camera is 376 connected and ready to use for external hot-plug cameras. Calls to get static 377 info will be invalid calls when camera status is not 378 <code>CAMERA_DEVICE_STATUS_PRESENT</code>. The framework counts solely on 379 device status change callbacks to manage the available external camera list. 380 </li> 381 382 <li><em>Camera arbitration hints</em>. Adds support for explicitly indicating 383 the number of camera devices that can be simultaneously opened and used. To 384 specify valid combinations of devices, the <code>resource_cost</code> and 385 <code>conflicting_devices</code> fields should always be set in the 386 <code>camera_info</code> structure returned by the <code>get_camera_info</code> 387 call.</li> 388 389 <li><em>Module initialization method</em>. Called by the camera service 390 after the HAL module is loaded to allow for one-time initialization of the HAL. 391 It is called before any other module methods are invoked.</li> 392 </ol> 393 394 <h3 id="23">2_3</h3> 395 396 <p>This camera module version adds open legacy camera HAL device support. 397 The framework can use it to open the camera device as lower device HAL version 398 HAL device if the same device can support multiple device API versions. 399 The standard hardware module open call (common.methods->open) continues 400 to open the camera device with the latest supported version, which is 401 also the version listed in <code>camera_info_t.device_version</code>.</p> 402 403 <h3 id="22">2_2</h3> 404 405 <p>This camera module version adds vendor tag support from the module, and 406 deprecates the old <code>vendor_tag_query_ops</code> that were previously only 407 accessible with a device open.</p> 408 409 <h3 id="21">2_1</h3> 410 411 <p>This camera module version adds support for asynchronous callbacks to the 412 framework from the camera HAL module, which is used to notify the framework 413 about changes to the camera module state. Modules that provide a valid 414 <code>set_callbacks()</code> method must report at least this version number.</p> 415 416 <h3 id="20">2_0</h3> 417 418 <p>Camera modules that report this version number implement the second version 419 of the camera module HAL interface. Camera devices openable through this 420 module may support either version 1.0 or version 2.0 of the camera device 421 HAL interface. The <code>device_version</code> field of camera_info is always 422 valid; the <code>static_camera_characteristics</code> field of 423 <code>camera_info</code> is valid if the <code>device_version</code> field is 424 2.0 or higher.</p> 425 426 <h3 id="10">1_0</h3> 427 428 <p>Camera modules that report these version numbers implement the initial 429 camera module HAL interface. All camera devices openable through this 430 module support only version 1 of the camera device HAL. The 431 <code>device_version</code> and <code>static_camera_characteristics</code> 432 fields of <code>camera_info</code> are not valid. Only the 433 <code>android.hardware.Camera</code> API can be supported by this module and its 434 devices.</p> 435
