1 /* 2 * Copyright (C) 2020 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package android.hardware.camera2; 18 19 import android.annotation.NonNull; 20 21 import java.util.concurrent.Executor; 22 23 /** 24 * A camera capture session that enables access to device-specific camera extensions, which 25 * often use multi-frame bursts and sophisticated post-process algorithms for image capture. 26 * 27 * <p>The capture session will be returned after a successful call to 28 * {@link CameraDevice#createExtensionSession} as part of the argument 29 * in the registered state callback {@link StateCallback#onConfigured} 30 * method. </p> 31 * 32 * <p>Note that CameraExtensionSession is currently limited to a maximum of two output 33 * surfaces for continuous repeating and multi-frame processing respectively. Some 34 * features such as capture settings will not be supported as the device-specific 35 * Extension is allowed to override all capture parameters.</p> 36 * 37 * <p>Information about support for specific device-specific extensions can be queried 38 * from {@link CameraExtensionCharacteristics}. </p> 39 */ 40 public abstract class CameraExtensionSession implements AutoCloseable { 41 /** @hide */ CameraExtensionSession()42 public CameraExtensionSession () {} 43 44 /** 45 * A callback object for tracking the progress of a 46 * {@link CaptureRequest} submitted to the camera device. 47 * 48 * <p>This callback is invoked when a request triggers a capture to start, 49 * and when the device-specific Extension post processing begins. In case of an 50 * error capturing an image, the error method is triggered instead of 51 * the completion method.</p> 52 * 53 * @see #capture 54 * @see #setRepeatingRequest 55 */ 56 public static abstract class ExtensionCaptureCallback { 57 58 /** 59 * This method is called when the camera device has started 60 * capturing the initial input image of the device-specific extension 61 * post-process request. 62 * 63 * <p>This callback is invoked right as the capture of a frame begins, 64 * so it is the most appropriate time for playing a shutter sound, 65 * or triggering UI indicators of capture.</p> 66 * 67 * <p>The request that is being used for this capture is provided, 68 * along with the actual timestamp for the start of exposure.</p> 69 * 70 * <p>The default implementation of this method does nothing.</p> 71 * 72 * @param session the session received during 73 * {@link StateCallback#onConfigured(CameraExtensionSession)} 74 * @param request the request for the capture that just begun 75 * @param timestamp the timestamp at start of capture for repeating 76 * request or the timestamp at start of capture of the 77 * first frame in a multi-frame capture. 78 */ onCaptureStarted(@onNull CameraExtensionSession session, @NonNull CaptureRequest request, long timestamp)79 public void onCaptureStarted(@NonNull CameraExtensionSession session, 80 @NonNull CaptureRequest request, long timestamp) { 81 // default empty implementation 82 } 83 84 /** 85 * This method is called when an image (or images in case of multi-frame 86 * capture) is captured and device-specific extension 87 * processing is triggered. 88 * 89 * <p>Each request will generate at most {@code 1} 90 * {@link #onCaptureProcessStarted}.</p> 91 * 92 * <p>The default implementation of this method does nothing.</p> 93 * 94 * @param session the session received during 95 * {@link StateCallback#onConfigured(CameraExtensionSession)} 96 * @param request The request that was given to the CameraExtensionSession 97 * 98 * @see #capture 99 * @see #setRepeatingRequest 100 */ onCaptureProcessStarted(@onNull CameraExtensionSession session, @NonNull CaptureRequest request)101 public void onCaptureProcessStarted(@NonNull CameraExtensionSession session, 102 @NonNull CaptureRequest request) { 103 // default empty implementation 104 } 105 106 /** 107 * This method is called instead of 108 * {@link #onCaptureProcessStarted} when the camera device failed 109 * to produce the required input for the device-specific extension. The 110 * cause could be a failed camera capture request, a failed 111 * capture result or dropped camera frame. 112 * 113 * <p>Other requests are unaffected, and some or all image buffers 114 * from the capture may have been pushed to their respective output 115 * streams.</p> 116 * 117 * <p>The default implementation of this method does nothing.</p> 118 * 119 * @param session the session received during 120 * {@link StateCallback#onConfigured(CameraExtensionSession)} 121 * @param request The request that was given to the CameraDevice 122 * 123 * @see #capture 124 * @see #setRepeatingRequest 125 */ onCaptureFailed(@onNull CameraExtensionSession session, @NonNull CaptureRequest request)126 public void onCaptureFailed(@NonNull CameraExtensionSession session, 127 @NonNull CaptureRequest request) { 128 // default empty implementation 129 } 130 131 /** 132 * This method is called independently of the others in 133 * ExtensionCaptureCallback, when a capture sequence finishes. 134 * 135 * <p>In total, there will be at least one 136 * {@link #onCaptureProcessStarted}/{@link #onCaptureFailed} 137 * invocation before this callback is triggered. If the capture 138 * sequence is aborted before any requests have begun processing, 139 * {@link #onCaptureSequenceAborted} is invoked instead.</p> 140 * 141 * <p>The default implementation does nothing.</p> 142 * 143 * @param session the session received during 144 * {@link StateCallback#onConfigured(CameraExtensionSession)} 145 * @param sequenceId A sequence ID returned by the {@link #capture} 146 * family of functions. 147 * @see #onCaptureSequenceAborted 148 */ onCaptureSequenceCompleted(@onNull CameraExtensionSession session, int sequenceId)149 public void onCaptureSequenceCompleted(@NonNull CameraExtensionSession session, 150 int sequenceId) { 151 // default empty implementation 152 } 153 154 /** 155 * This method is called when a capture sequence aborts. 156 * 157 * <p>Due to the asynchronous nature of the camera device, not all 158 * submitted captures are immediately processed. It is possible to 159 * clear out the pending requests by a variety of operations such 160 * as {@link CameraExtensionSession#stopRepeating}. When such an event 161 * happens, {@link #onCaptureProcessStarted} will not be called.</p> 162 * 163 * <p>The default implementation does nothing.</p> 164 * 165 * @param session the session received during 166 * {@link StateCallback#onConfigured(CameraExtensionSession)} 167 * @param sequenceId A sequence ID returned by the {@link #capture} 168 * family of functions. 169 * @see #onCaptureProcessStarted 170 */ onCaptureSequenceAborted(@onNull CameraExtensionSession session, int sequenceId)171 public void onCaptureSequenceAborted(@NonNull CameraExtensionSession session, 172 int sequenceId) { 173 // default empty implementation 174 } 175 } 176 177 /** 178 * A callback object for receiving updates about the state of a camera extension session. 179 * 180 */ 181 public static abstract class StateCallback { 182 183 /** 184 * This method is called when the camera device has finished configuring itself, and the 185 * session can start processing capture requests. 186 * 187 * <p>If the camera device configuration fails, then {@link #onConfigureFailed} will 188 * be invoked instead of this callback.</p> 189 * 190 * @param session A valid extension session 191 */ onConfigured(@onNull CameraExtensionSession session)192 public abstract void onConfigured(@NonNull CameraExtensionSession session); 193 194 /** 195 * This method is called if the session cannot be configured as requested. 196 * 197 * <p>This can happen if the set of requested outputs contains unsupported sizes, 198 * too many outputs are requested at once or when trying to initialize multiple 199 * concurrent extension sessions from two (or more) separate camera devices 200 * or the camera device encounters an unrecoverable error during configuration.</p> 201 * 202 * <p>The session is considered to be closed, and all methods called on it after this 203 * callback is invoked will throw an IllegalStateException.</p> 204 * 205 * @param session the session instance that failed to configure 206 */ onConfigureFailed(@onNull CameraExtensionSession session)207 public abstract void onConfigureFailed(@NonNull CameraExtensionSession session); 208 209 /** 210 * This method is called when the session is closed. 211 * 212 * <p>A session is closed when a new session is created by the parent camera device, 213 * or when the parent camera device is closed (either by the user closing the device, 214 * or due to a camera device disconnection or fatal error).</p> 215 * 216 * <p>Once a session is closed, all methods on it will throw an IllegalStateException, and 217 * any repeating requests are stopped (as if {@link #stopRepeating()} was called). 218 * However, any in-progress capture requests submitted to the session will be completed 219 * as normal.</p> 220 * 221 * @param session the session received during 222 * {@link StateCallback#onConfigured(CameraExtensionSession)} 223 */ onClosed(@onNull CameraExtensionSession session)224 public void onClosed(@NonNull CameraExtensionSession session) { 225 // default empty implementation 226 } 227 } 228 229 /** 230 * Get the camera device that this session is created for. 231 */ 232 @NonNull getDevice()233 public android.hardware.camera2.CameraDevice getDevice() { 234 throw new UnsupportedOperationException("Subclasses must override this method"); 235 } 236 237 /** 238 * Submit a request for device-specific processing using input 239 * from the camera device, to produce a single high-quality output result. 240 * 241 * <p>Note that single capture requests currently do not support 242 * client parameters except for {@link CaptureRequest#JPEG_ORIENTATION orientation} and 243 * {@link CaptureRequest#JPEG_QUALITY quality} in case of ImageFormat.JPEG output target. 244 * The rest of the settings included in the request will be entirely overridden by 245 * the device-specific extension. </p> 246 * 247 * <p>The {@link CaptureRequest.Builder#addTarget} supports only one 248 * ImageFormat.YUV_420_888 or ImageFormat.JPEG target surface. {@link CaptureRequest} 249 * arguments that include further targets will cause 250 * IllegalArgumentException to be thrown. </p> 251 * 252 * <p>Each request will produce one new frame for one target Surface, set 253 * with the CaptureRequest builder's 254 * {@link CaptureRequest.Builder#addTarget} method.</p> 255 * 256 * <p>Multiple requests can be in progress at once. Requests are 257 * processed in first-in, first-out order.</p> 258 * 259 * <p>Requests submitted through this method have higher priority than 260 * those submitted through {@link #setRepeatingRequest}, and will be 261 * processed as soon as the current repeat processing completes.</p> 262 * 263 * @param request the settings for this capture 264 * @param executor the executor which will be used for invoking the 265 * listener. 266 * @param listener The callback object to notify once this request has 267 * been processed. 268 * @return int A unique capture sequence ID used by 269 * {@link ExtensionCaptureCallback#onCaptureSequenceCompleted}. 270 * @throws CameraAccessException if the camera device is no longer 271 * connected or has encountered a fatal error 272 * @throws IllegalStateException if this session is no longer active, 273 * either because the session was explicitly closed, a new 274 * session has been created or the camera device has been 275 * closed. 276 * @throws IllegalArgumentException if the request targets no Surfaces 277 * or Surfaces that are not configured as outputs for this 278 * session; or the request targets a set of Surfaces that 279 * cannot be submitted simultaneously. 280 */ capture(@onNull CaptureRequest request, @NonNull Executor executor, @NonNull ExtensionCaptureCallback listener)281 public int capture(@NonNull CaptureRequest request, 282 @NonNull Executor executor, 283 @NonNull ExtensionCaptureCallback listener) throws CameraAccessException { 284 throw new UnsupportedOperationException("Subclasses must override this method"); 285 } 286 287 /** 288 * Request endlessly repeating device-specific extension processing of 289 * camera images. 290 * 291 * <p>With this method, the camera device will continually capture images 292 * and process them using the device-specific extension at the maximum 293 * rate possible.</p> 294 * 295 * <p>Note that repeating capture requests currently do not support 296 * client parameters. Settings included in the request will 297 * be completely overridden by the device-specific extension.</p> 298 * 299 * <p>The {@link CaptureRequest.Builder#addTarget} supports only one 300 * target surface. {@link CaptureRequest} arguments that include further 301 * targets will cause IllegalArgumentException to be thrown.</p> 302 * 303 * <p>Repeating requests are a simple way for an application to maintain a 304 * preview or other continuous stream of frames.</p> 305 * 306 * <p>Repeat requests have lower priority than those submitted 307 * through {@link #capture}, so if {@link #capture} is called when a 308 * repeating request is active, the capture request will be processed 309 * before any further repeating requests are processed.</p> 310 * 311 * <p>To stop the repeating capture, call {@link #stopRepeating}.</p> 312 * 313 * <p>Calling this method will replace any earlier repeating request.</p> 314 * 315 * @param request the request to repeat indefinitely 316 * @param executor the executor which will be used for invoking the 317 * listener. 318 * @param listener The callback object to notify every time the 319 * request finishes processing. 320 * @return int A unique capture sequence ID used by 321 * {@link ExtensionCaptureCallback#onCaptureSequenceCompleted}. 322 * @throws CameraAccessException if the camera device is no longer 323 * connected or has encountered a fatal error 324 * @throws IllegalStateException if this session is no longer active, 325 * either because the session was explicitly closed, a new 326 * session has been created or the camera device has been 327 * closed. 328 * @throws IllegalArgumentException If the request references no 329 * Surfaces or references Surfaces that are not currently 330 * configured as outputs. 331 * @see #capture 332 */ setRepeatingRequest(@onNull CaptureRequest request, @NonNull Executor executor, @NonNull ExtensionCaptureCallback listener)333 public int setRepeatingRequest(@NonNull CaptureRequest request, 334 @NonNull Executor executor, 335 @NonNull ExtensionCaptureCallback listener) throws CameraAccessException { 336 throw new UnsupportedOperationException("Subclasses must override this method"); 337 } 338 339 /** 340 * Cancel any ongoing repeating capture set by 341 * {@link #setRepeatingRequest setRepeatingRequest}. Has no effect on 342 * requests submitted through {@link #capture capture}. 343 * 344 * <p>Any currently in-flight captures will still complete.</p> 345 * 346 * @throws CameraAccessException if the camera device is no longer 347 * connected or has encountered a fatal error 348 * @throws IllegalStateException if this session is no longer active, 349 * either because the session was explicitly closed, a new 350 * session has been created or the camera device has been closed. 351 * @see #setRepeatingRequest 352 */ stopRepeating()353 public void stopRepeating() throws CameraAccessException { 354 throw new UnsupportedOperationException("Subclasses must override this method"); 355 } 356 357 /** 358 * Close this capture session asynchronously. 359 * 360 * <p>Closing a session frees up the target output Surfaces of the session 361 * for reuse with either a new session, or to other APIs that can draw 362 * to Surfaces.</p> 363 * 364 * <p>Note that creating a new capture session with 365 * {@link android.hardware.camera2.CameraDevice#createCaptureSession} or 366 * {@link android.hardware.camera2.CameraDevice#createExtensionSession} 367 * will close any existing capture session automatically, and call the 368 * older session listener's {@link StateCallback#onClosed} callback. 369 * Using 370 * {@link android.hardware.camera2.CameraDevice#createCaptureSession} or 371 * {@link android.hardware.camera2.CameraDevice#createExtensionSession} 372 * directly without closing is the recommended approach for quickly 373 * switching to a new session, since unchanged target outputs can be 374 * reused more efficiently.</p> 375 * 376 * <p>Once a session is closed, all methods on it will throw an 377 * IllegalStateException, and any repeating requests are 378 * stopped (as if {@link #stopRepeating()} was called).</p> 379 * 380 * <p>Closing a session is idempotent; closing more than once has no 381 * effect.</p> 382 */ close()383 public void close() throws CameraAccessException { 384 throw new UnsupportedOperationException("Subclasses must override this method"); 385 } 386 } 387