1 /* 2 * Copyright (C) 2014 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 import android.annotation.Nullable; 21 import android.os.Handler; 22 import android.view.Surface; 23 24 import java.util.List; 25 26 27 /** 28 * A configured capture session for a {@link CameraDevice}, used for capturing images from the 29 * camera or reprocessing images captured from the camera in the same session previously. 30 * 31 * <p>A CameraCaptureSession is created by providing a set of target output surfaces to 32 * {@link CameraDevice#createCaptureSession createCaptureSession}, or by providing an 33 * {@link android.hardware.camera2.params.InputConfiguration} and a set of target output surfaces to 34 * {@link CameraDevice#createReprocessableCaptureSession createReprocessableCaptureSession} for a 35 * reprocessable capture session. Once created, the session is active until a new session is 36 * created by the camera device, or the camera device is closed.</p> 37 * 38 * <p>All capture sessions can be used for capturing images from the camera but only reprocessable 39 * capture sessions can reprocess images captured from the camera in the same session previously. 40 * </p> 41 * 42 * <p>Creating a session is an expensive operation and can take several hundred milliseconds, since 43 * it requires configuring the camera device's internal pipelines and allocating memory buffers for 44 * sending images to the desired targets. Therefore the setup is done asynchronously, and 45 * {@link CameraDevice#createCaptureSession createCaptureSession} and 46 * {@link CameraDevice#createReprocessableCaptureSession createReprocessableCaptureSession} will 47 * send the ready-to-use CameraCaptureSession to the provided listener's 48 * {@link CameraCaptureSession.StateCallback#onConfigured onConfigured} callback. If configuration 49 * cannot be completed, then the 50 * {@link CameraCaptureSession.StateCallback#onConfigureFailed onConfigureFailed} is called, and the 51 * session will not become active.</p> 52 *<!-- 53 * <p>Any capture requests (repeating or non-repeating) submitted before the session is ready will 54 * be queued up and will begin capture once the session becomes ready. In case the session cannot be 55 * configured and {@link StateCallback#onConfigureFailed onConfigureFailed} is called, all queued 56 * capture requests are discarded.</p> 57 *--> 58 * <p>If a new session is created by the camera device, then the previous session is closed, and its 59 * associated {@link StateCallback#onClosed onClosed} callback will be invoked. All 60 * of the session methods will throw an IllegalStateException if called once the session is 61 * closed.</p> 62 * 63 * <p>A closed session clears any repeating requests (as if {@link #stopRepeating} had been called), 64 * but will still complete all of its in-progress capture requests as normal, before a newly 65 * created session takes over and reconfigures the camera device.</p> 66 */ 67 public abstract class CameraCaptureSession implements AutoCloseable { 68 69 /** 70 * Used to identify invalid session ID. 71 * @hide 72 */ 73 public static final int SESSION_ID_NONE = -1; 74 75 /** 76 * Get the camera device that this session is created for. 77 */ 78 @NonNull 79 public abstract CameraDevice getDevice(); 80 81 /** 82 * <p>Pre-allocate all buffers for an output Surface.</p> 83 * 84 * <p>Normally, the image buffers for a given output Surface are allocated on-demand, 85 * to minimize startup latency and memory overhead.</p> 86 * 87 * <p>However, in some cases, it may be desirable for the buffers to be allocated before 88 * any requests targeting the Surface are actually submitted to the device. Large buffers 89 * may take some time to allocate, which can result in delays in submitting requests until 90 * sufficient buffers are allocated to reach steady-state behavior. Such delays can cause 91 * bursts to take longer than desired, or cause skips or stutters in preview output.</p> 92 * 93 * <p>The prepare() method can be used to perform this preallocation. It may only be called for 94 * a given output Surface before that Surface is used as a target for a request. The number of 95 * buffers allocated is the sum of the count needed by the consumer providing the output 96 * Surface, and the maximum number needed by the camera device to fill its pipeline. Since this 97 * may be a larger number than what is actually required for steady-state operation, using 98 * prepare may result in higher memory consumption than the normal on-demand behavior results 99 * in. Prepare() will also delay the time to first output to a given Surface, in exchange for 100 * smoother frame rate once the allocation is complete.</p> 101 * 102 * <p>For example, an application that creates an 103 * {@link android.media.ImageReader#newInstance ImageReader} with a maxImages argument of 10, 104 * but only uses 3 simultaneous Images at once would normally only cause those 3 images to be 105 * allocated (plus what is needed by the camera device for smooth operation). But using 106 * prepare() on the ImageReader Surface will result in all 10 Images being allocated. So 107 * applications using this method should take care to request only the number of buffers 108 * actually necessary for their application.</p> 109 * 110 * <p>If the same output Surface is used in consecutive sessions (without closing the first 111 * session explicitly), then its already-allocated buffers are carried over, and if it was 112 * used as a target of a capture request in the first session, prepare cannot be called on it 113 * in the second session.</p> 114 * 115 * <p>Once allocation is complete, {@link StateCallback#onSurfacePrepared} will be invoked with 116 * the Surface provided to this method. Between the prepare call and the onSurfacePrepared call, 117 * the Surface provided to prepare must not be used as a target of a CaptureRequest submitted 118 * to this session.</p> 119 * 120 * <p>{@link android.hardware.camera2.CameraCharacteristics#INFO_SUPPORTED_HARDWARE_LEVEL_LEGACY LEGACY} 121 * devices cannot pre-allocate output buffers; for those devices, 122 * {@link StateCallback#onSurfacePrepared} will be immediately called, and no preallocation is 123 * done.</p> 124 * 125 * @param surface the output Surface for which buffers should be pre-allocated. Must be one of 126 * the output Surfaces used to create this session. 127 * 128 * @throws CameraAccessException if the camera device is no longer connected or has 129 * encountered a fatal error 130 * @throws IllegalStateException if this session is no longer active, either because the session 131 * was explicitly closed, a new session has been created 132 * or the camera device has been closed. 133 * @throws IllegalArgumentException if the Surface is invalid, not part of this Session, or has 134 * already been used as a target of a CaptureRequest in this 135 * session or immediately prior sessions. 136 * 137 * @see StateCallback#onSurfacePrepared 138 */ 139 public abstract void prepare(@NonNull Surface surface) throws CameraAccessException; 140 141 142 /** 143 * <p>Free all buffers allocated for an output Surface.</p> 144 * 145 * <p>Normally, once allocated, the image buffers for a given output Surface remain allocated 146 * for the lifetime of the capture session, to minimize latency of captures and to reduce 147 * memory allocation overhead.</p> 148 * 149 * <p>However, in some cases, it may be desirable for allocated buffers to be freed to reduce 150 * the application's memory consumption, if the particular output Surface will not be used by 151 * the application for some time.</p> 152 * 153 * <p>The tearDown() method can be used to perform this operation. After the call finishes, all 154 * unfilled image buffers will have been freed. Any future use of the target Surface may require 155 * allocation of additional buffers, as if the session had just been created. Buffers being 156 * held by the application (either explicitly as Image objects from ImageReader, or implicitly 157 * as the current texture in a SurfaceTexture or the current contents of a RS Allocation, will 158 * remain valid and allocated even when tearDown is invoked.</p> 159 * 160 * <p>A Surface that has had tearDown() called on it is eligible to have prepare() invoked on it 161 * again even if it was used as a request target before the tearDown() call, as long as it 162 * doesn't get used as a target of a request between the tearDown() and prepare() calls.</p> 163 * 164 * @param surface the output Surface for which buffers should be freed. Must be one of the 165 * the output Surfaces used to create this session. 166 * 167 * @throws CameraAccessException if the camera device is no longer connected or has 168 * encountered a fatal error. 169 * @throws IllegalStateException if this session is no longer active, either because the session 170 * was explicitly closed, a new session has been created 171 * or the camera device has been closed. 172 * @throws IllegalArgumentException if the Surface is invalid, not part of this Session, or has 173 * already been used as a target of a CaptureRequest in this 174 * session or immediately prior sessions. 175 * 176 * @hide 177 */ 178 public abstract void tearDown(@NonNull Surface surface) throws CameraAccessException; 179 180 /** 181 * <p>Submit a request for an image to be captured by the camera device.</p> 182 * 183 * <p>The request defines all the parameters for capturing the single image, 184 * including sensor, lens, flash, and post-processing settings.</p> 185 * 186 * <p>Each request will produce one {@link CaptureResult} and produce new frames for one or more 187 * target Surfaces, set with the CaptureRequest builder's 188 * {@link CaptureRequest.Builder#addTarget} method. The target surfaces (set with 189 * {@link CaptureRequest.Builder#addTarget}) must be a subset of the surfaces provided when this 190 * capture session was created.</p> 191 * 192 * <p>Multiple regular and reprocess requests can be in progress at once. If there are only 193 * regular requests or reprocess requests in progress, they are processed in first-in, 194 * first-out order. If there are both regular and reprocess requests in progress, regular 195 * requests are processed in first-in, first-out order and reprocess requests are processed in 196 * first-in, first-out order, respectively. However, the processing order of a regular request 197 * and a reprocess request in progress is not specified. In other words, a regular request 198 * will always be processed before regular requets that are submitted later. A reprocess request 199 * will always be processed before reprocess requests that are submitted later. However, a 200 * regular request may not be processed before reprocess requests that are submitted later.<p> 201 * 202 * <p>Requests submitted through this method have higher priority than 203 * those submitted through {@link #setRepeatingRequest} or 204 * {@link #setRepeatingBurst}, and will be processed as soon as the current 205 * repeat/repeatBurst processing completes.</p> 206 * 207 * <p>All capture sessions can be used for capturing images from the camera but only capture 208 * sessions created by 209 * {@link CameraDevice#createReprocessableCaptureSession createReprocessableCaptureSession} 210 * can submit reprocess capture requests. Submitting a reprocess request to a regular capture 211 * session will result in an {@link IllegalArgumentException}.</p> 212 * 213 * @param request the settings for this capture 214 * @param listener The callback object to notify once this request has been 215 * processed. If null, no metadata will be produced for this capture, 216 * although image data will still be produced. 217 * @param handler the handler on which the listener should be invoked, or 218 * {@code null} to use the current thread's {@link android.os.Looper 219 * looper}. 220 * 221 * @return int A unique capture sequence ID used by 222 * {@link CaptureCallback#onCaptureSequenceCompleted}. 223 * 224 * @throws CameraAccessException if the camera device is no longer connected or has 225 * encountered a fatal error 226 * @throws IllegalStateException if this session is no longer active, either because the session 227 * was explicitly closed, a new session has been created 228 * or the camera device has been closed. 229 * @throws IllegalArgumentException if the request targets no Surfaces or Surfaces that are not 230 * configured as outputs for this session; or the request 231 * targets a set of Surfaces that cannot be submitted 232 * simultaneously in a reprocessable capture session; or a 233 * reprocess capture request is submitted in a 234 * non-reprocessable capture session; or the reprocess capture 235 * request was created with a {@link TotalCaptureResult} from 236 * a different session; or the capture targets a Surface in 237 * the middle of being {@link #prepare prepared}; or the 238 * handler is null, the listener is not null, and the calling 239 * thread has no looper. 240 * 241 * @see #captureBurst 242 * @see #setRepeatingRequest 243 * @see #setRepeatingBurst 244 * @see #abortCaptures 245 * @see CameraDevice#createReprocessableCaptureSession 246 */ 247 public abstract int capture(@NonNull CaptureRequest request, 248 @Nullable CaptureCallback listener, @Nullable Handler handler) 249 throws CameraAccessException; 250 251 /** 252 * Submit a list of requests to be captured in sequence as a burst. The 253 * burst will be captured in the minimum amount of time possible, and will 254 * not be interleaved with requests submitted by other capture or repeat 255 * calls. 256 * 257 * <p>Regular and reprocess requests can be mixed together in a single burst. Regular requests 258 * will be captured in order and reprocess requests will be processed in order, respectively. 259 * However, the processing order between a regular request and a reprocess request is not 260 * specified. Each capture produces one {@link CaptureResult} and image buffers for one or more 261 * target {@link android.view.Surface surfaces}. The target surfaces (set with 262 * {@link CaptureRequest.Builder#addTarget}) must be a subset of the surfaces provided when 263 * this capture session was created.</p> 264 * 265 * <p>The main difference between this method and simply calling 266 * {@link #capture} repeatedly is that this method guarantees that no 267 * other requests will be interspersed with the burst.</p> 268 * 269 * <p>All capture sessions can be used for capturing images from the camera but only capture 270 * sessions created by 271 * {@link CameraDevice#createReprocessableCaptureSession createReprocessableCaptureSession} 272 * can submit reprocess capture requests. Submitting a reprocess request to a regular 273 * capture session will result in an {@link IllegalArgumentException}.</p> 274 * 275 * @param requests the list of settings for this burst capture 276 * @param listener The callback object to notify each time one of the 277 * requests in the burst has been processed. If null, no metadata will be 278 * produced for any requests in this burst, although image data will still 279 * be produced. 280 * @param handler the handler on which the listener should be invoked, or 281 * {@code null} to use the current thread's {@link android.os.Looper 282 * looper}. 283 * 284 * @return int A unique capture sequence ID used by 285 * {@link CaptureCallback#onCaptureSequenceCompleted}. 286 * 287 * @throws CameraAccessException if the camera device is no longer connected or has 288 * encountered a fatal error 289 * @throws IllegalStateException if this session is no longer active, either because the session 290 * was explicitly closed, a new session has been created 291 * or the camera device has been closed. 292 * @throws IllegalArgumentException If the requests target no Surfaces, or the requests target 293 * Surfaces not currently configured as outputs; or one of the 294 * requests targets a set of Surfaces that cannot be submitted 295 * simultaneously in a reprocessable capture session; or a 296 * reprocess capture request is submitted in a 297 * non-reprocessable capture session; or one of the reprocess 298 * capture requests was created with a 299 * {@link TotalCaptureResult} from a different session; or one 300 * of the captures targets a Surface in the middle of being 301 * {@link #prepare prepared}; or if the handler is null, the 302 * listener is not null, and the calling thread has no looper. 303 * 304 * @see #capture 305 * @see #setRepeatingRequest 306 * @see #setRepeatingBurst 307 * @see #abortCaptures 308 */ 309 public abstract int captureBurst(@NonNull List<CaptureRequest> requests, 310 @Nullable CaptureCallback listener, @Nullable Handler handler) 311 throws CameraAccessException; 312 313 /** 314 * Request endlessly repeating capture of images by this capture session. 315 * 316 * <p>With this method, the camera device will continually capture images 317 * using the settings in the provided {@link CaptureRequest}, at the maximum 318 * rate possible.</p> 319 * 320 * <p>Repeating requests are a simple way for an application to maintain a 321 * preview or other continuous stream of frames, without having to 322 * continually submit identical requests through {@link #capture}.</p> 323 * 324 * <p>Repeat requests have lower priority than those submitted 325 * through {@link #capture} or {@link #captureBurst}, so if 326 * {@link #capture} is called when a repeating request is active, the 327 * capture request will be processed before any further repeating 328 * requests are processed.<p> 329 * 330 * <p>To stop the repeating capture, call {@link #stopRepeating}. Calling 331 * {@link #abortCaptures} will also clear the request.</p> 332 * 333 * <p>Calling this method will replace any earlier repeating request or 334 * burst set up by this method or {@link #setRepeatingBurst}, although any 335 * in-progress burst will be completed before the new repeat request will be 336 * used.</p> 337 * 338 * <p>This method does not support reprocess capture requests because each reprocess 339 * {@link CaptureRequest} must be created from the {@link TotalCaptureResult} that matches 340 * the input image to be reprocessed. This is either the {@link TotalCaptureResult} of capture 341 * that is sent for reprocessing, or one of the {@link TotalCaptureResult TotalCaptureResults} 342 * of a set of captures, when data from the whole set is combined by the application into a 343 * single reprocess input image. The request must be capturing images from the camera. If a 344 * reprocess capture request is submitted, this method will throw IllegalArgumentException.</p> 345 * 346 * @param request the request to repeat indefinitely 347 * @param listener The callback object to notify every time the 348 * request finishes processing. If null, no metadata will be 349 * produced for this stream of requests, although image data will 350 * still be produced. 351 * @param handler the handler on which the listener should be invoked, or 352 * {@code null} to use the current thread's {@link android.os.Looper 353 * looper}. 354 * 355 * @return int A unique capture sequence ID used by 356 * {@link CaptureCallback#onCaptureSequenceCompleted}. 357 * 358 * @throws CameraAccessException if the camera device is no longer connected or has 359 * encountered a fatal error 360 * @throws IllegalStateException if this session is no longer active, either because the session 361 * was explicitly closed, a new session has been created 362 * or the camera device has been closed. 363 * @throws IllegalArgumentException If the request references no Surfaces or references Surfaces 364 * that are not currently configured as outputs; or the request 365 * is a reprocess capture request; or the capture targets a 366 * Surface in the middle of being {@link #prepare prepared}; or 367 * the handler is null, the listener is not null, and the 368 * calling thread has no looper; or no requests were passed in. 369 * 370 * @see #capture 371 * @see #captureBurst 372 * @see #setRepeatingBurst 373 * @see #stopRepeating 374 * @see #abortCaptures 375 */ 376 public abstract int setRepeatingRequest(@NonNull CaptureRequest request, 377 @Nullable CaptureCallback listener, @Nullable Handler handler) 378 throws CameraAccessException; 379 380 /** 381 * <p>Request endlessly repeating capture of a sequence of images by this 382 * capture session.</p> 383 * 384 * <p>With this method, the camera device will continually capture images, 385 * cycling through the settings in the provided list of 386 * {@link CaptureRequest CaptureRequests}, at the maximum rate possible.</p> 387 * 388 * <p>If a request is submitted through {@link #capture} or 389 * {@link #captureBurst}, the current repetition of the request list will be 390 * completed before the higher-priority request is handled. This guarantees 391 * that the application always receives a complete repeat burst captured in 392 * minimal time, instead of bursts interleaved with higher-priority 393 * captures, or incomplete captures.</p> 394 * 395 * <p>Repeating burst requests are a simple way for an application to 396 * maintain a preview or other continuous stream of frames where each 397 * request is different in a predicatable way, without having to continually 398 * submit requests through {@link #captureBurst}.</p> 399 * 400 * <p>To stop the repeating capture, call {@link #stopRepeating}. Any 401 * ongoing burst will still be completed, however. Calling 402 * {@link #abortCaptures} will also clear the request.</p> 403 * 404 * <p>Calling this method will replace a previously-set repeating request or 405 * burst set up by this method or {@link #setRepeatingRequest}, although any 406 * in-progress burst will be completed before the new repeat burst will be 407 * used.</p> 408 * 409 * <p>This method does not support reprocess capture requests because each reprocess 410 * {@link CaptureRequest} must be created from the {@link TotalCaptureResult} that matches 411 * the input image to be reprocessed. This is either the {@link TotalCaptureResult} of capture 412 * that is sent for reprocessing, or one of the {@link TotalCaptureResult TotalCaptureResults} 413 * of a set of captures, when data from the whole set is combined by the application into a 414 * single reprocess input image. The request must be capturing images from the camera. If a 415 * reprocess capture request is submitted, this method will throw IllegalArgumentException.</p> 416 * 417 * @param requests the list of requests to cycle through indefinitely 418 * @param listener The callback object to notify each time one of the 419 * requests in the repeating bursts has finished processing. If null, no 420 * metadata will be produced for this stream of requests, although image 421 * data will still be produced. 422 * @param handler the handler on which the listener should be invoked, or 423 * {@code null} to use the current thread's {@link android.os.Looper 424 * looper}. 425 * 426 * @return int A unique capture sequence ID used by 427 * {@link CaptureCallback#onCaptureSequenceCompleted}. 428 * 429 * @throws CameraAccessException if the camera device is no longer connected or has 430 * encountered a fatal error 431 * @throws IllegalStateException if this session is no longer active, either because the session 432 * was explicitly closed, a new session has been created 433 * or the camera device has been closed. 434 * @throws IllegalArgumentException If the requests reference no Surfaces or reference Surfaces 435 * not currently configured as outputs; or one of the requests 436 * is a reprocess capture request; or one of the captures 437 * targets a Surface in the middle of being 438 * {@link #prepare prepared}; or the handler is null, the 439 * listener is not null, and the calling thread has no looper; 440 * or no requests were passed in. 441 * 442 * @see #capture 443 * @see #captureBurst 444 * @see #setRepeatingRequest 445 * @see #stopRepeating 446 * @see #abortCaptures 447 */ 448 public abstract int setRepeatingBurst(@NonNull List<CaptureRequest> requests, 449 @Nullable CaptureCallback listener, @Nullable Handler handler) 450 throws CameraAccessException; 451 452 /** 453 * <p>Cancel any ongoing repeating capture set by either 454 * {@link #setRepeatingRequest setRepeatingRequest} or 455 * {@link #setRepeatingBurst}. Has no effect on requests submitted through 456 * {@link #capture capture} or {@link #captureBurst captureBurst}.</p> 457 * 458 * <p>Any currently in-flight captures will still complete, as will any burst that is 459 * mid-capture. To ensure that the device has finished processing all of its capture requests 460 * and is in ready state, wait for the {@link StateCallback#onReady} callback after 461 * calling this method.</p> 462 * 463 * @throws CameraAccessException if the camera device is no longer connected or has 464 * encountered a fatal error 465 * @throws IllegalStateException if this session is no longer active, either because the session 466 * was explicitly closed, a new session has been created 467 * or the camera device has been closed. 468 * 469 * @see #setRepeatingRequest 470 * @see #setRepeatingBurst 471 * @see StateCallback#onIdle 472 */ 473 public abstract void stopRepeating() throws CameraAccessException; 474 475 /** 476 * Discard all captures currently pending and in-progress as fast as possible. 477 * 478 * <p>The camera device will discard all of its current work as fast as possible. Some in-flight 479 * captures may complete successfully and call {@link CaptureCallback#onCaptureCompleted}, while 480 * others will trigger their {@link CaptureCallback#onCaptureFailed} callbacks. If a repeating 481 * request or a repeating burst is set, it will be cleared.</p> 482 * 483 * <p>This method is the fastest way to switch the camera device to a new session with 484 * {@link CameraDevice#createCaptureSession} or 485 * {@link CameraDevice#createReprocessableCaptureSession}, at the cost of discarding in-progress 486 * work. It must be called before the new session is created. Once all pending requests are 487 * either completed or thrown away, the {@link StateCallback#onReady} callback will be called, 488 * if the session has not been closed. Otherwise, the {@link StateCallback#onClosed} 489 * callback will be fired when a new session is created by the camera device.</p> 490 * 491 * <p>Cancelling will introduce at least a brief pause in the stream of data from the camera 492 * device, since once the camera device is emptied, the first new request has to make it through 493 * the entire camera pipeline before new output buffers are produced.</p> 494 * 495 * <p>This means that using {@code abortCaptures()} to simply remove pending requests is not 496 * recommended; it's best used for quickly switching output configurations, or for cancelling 497 * long in-progress requests (such as a multi-second capture).</p> 498 * 499 * @throws CameraAccessException if the camera device is no longer connected or has 500 * encountered a fatal error 501 * @throws IllegalStateException if this session is no longer active, either because the session 502 * was explicitly closed, a new session has been created 503 * or the camera device has been closed. 504 * 505 * @see #setRepeatingRequest 506 * @see #setRepeatingBurst 507 * @see CameraDevice#createCaptureSession 508 * @see CameraDevice#createReprocessableCaptureSession 509 */ 510 public abstract void abortCaptures() throws CameraAccessException; 511 512 /** 513 * Return if the application can submit reprocess capture requests with this camera capture 514 * session. 515 * 516 * @return {@code true} if the application can submit reprocess capture requests with this 517 * camera capture session. {@code false} otherwise. 518 * 519 * @see CameraDevice#createReprocessableCaptureSession 520 */ 521 public abstract boolean isReprocessable(); 522 523 /** 524 * Get the input Surface associated with a reprocessable capture session. 525 * 526 * <p>Each reprocessable capture session has an input {@link Surface} where the reprocess 527 * capture requests get the input images from, rather than the camera device. The application 528 * can create a {@link android.media.ImageWriter ImageWriter} with this input {@link Surface} 529 * and use it to provide input images for reprocess capture requests. When the reprocessable 530 * capture session is closed, the input {@link Surface} is abandoned and becomes invalid.</p> 531 * 532 * @return The {@link Surface} where reprocessing capture requests get the input images from. If 533 * this is not a reprocess capture session, {@code null} will be returned. 534 * 535 * @see CameraDevice#createReprocessableCaptureSession 536 * @see android.media.ImageWriter 537 * @see android.media.ImageReader 538 */ 539 @Nullable 540 public abstract Surface getInputSurface(); 541 542 /** 543 * Close this capture session asynchronously. 544 * 545 * <p>Closing a session frees up the target output Surfaces of the session for reuse with either 546 * a new session, or to other APIs that can draw to Surfaces.</p> 547 * 548 * <p>Note that creating a new capture session with {@link CameraDevice#createCaptureSession} 549 * will close any existing capture session automatically, and call the older session listener's 550 * {@link StateCallback#onClosed} callback. Using {@link CameraDevice#createCaptureSession} 551 * directly without closing is the recommended approach for quickly switching to a new session, 552 * since unchanged target outputs can be reused more efficiently.</p> 553 * 554 * <p>Once a session is closed, all methods on it will throw an IllegalStateException, and any 555 * repeating requests or bursts are stopped (as if {@link #stopRepeating()} was called). 556 * However, any in-progress capture requests submitted to the session will be completed as 557 * normal; once all captures have completed and the session has been torn down, 558 * {@link StateCallback#onClosed} will be called.</p> 559 * 560 * <p>Closing a session is idempotent; closing more than once has no effect.</p> 561 */ 562 @Override 563 public abstract void close(); 564 565 /** 566 * A callback object for receiving updates about the state of a camera capture session. 567 * 568 */ 569 public static abstract class StateCallback { 570 571 /** 572 * This method is called when the camera device has finished configuring itself, and the 573 * session can start processing capture requests. 574 * 575 * <p>If there are capture requests already queued with the session, they will start 576 * processing once this callback is invoked, and the session will call {@link #onActive} 577 * right after this callback is invoked.</p> 578 * 579 * <p>If no capture requests have been submitted, then the session will invoke 580 * {@link #onReady} right after this callback.</p> 581 * 582 * <p>If the camera device configuration fails, then {@link #onConfigureFailed} will 583 * be invoked instead of this callback.</p> 584 * 585 * @param session the session returned by {@link CameraDevice#createCaptureSession} 586 */ 587 public abstract void onConfigured(@NonNull CameraCaptureSession session); 588 589 /** 590 * This method is called if the session cannot be configured as requested. 591 * 592 * <p>This can happen if the set of requested outputs contains unsupported sizes, 593 * or too many outputs are requested at once.</p> 594 * 595 * <p>The session is considered to be closed, and all methods called on it after this 596 * callback is invoked will throw an IllegalStateException. Any capture requests submitted 597 * to the session prior to this callback will be discarded and will not produce any 598 * callbacks on their listeners.</p> 599 * 600 * @param session the session returned by {@link CameraDevice#createCaptureSession} 601 */ 602 public abstract void onConfigureFailed(@NonNull CameraCaptureSession session); 603 604 /** 605 * This method is called every time the session has no more capture requests to process. 606 * 607 * <p>During the creation of a new session, this callback is invoked right after 608 * {@link #onConfigured} if no capture requests were submitted to the session prior to it 609 * completing configuration.</p> 610 * 611 * <p>Otherwise, this callback will be invoked any time the session finishes processing 612 * all of its active capture requests, and no repeating request or burst is set up.</p> 613 * 614 * @param session the session returned by {@link CameraDevice#createCaptureSession} 615 * 616 */ 617 public void onReady(@NonNull CameraCaptureSession session) { 618 // default empty implementation 619 } 620 621 /** 622 * This method is called when the session starts actively processing capture requests. 623 * 624 * <p>If capture requests are submitted prior to {@link #onConfigured} being called, 625 * then the session will start processing those requests immediately after the callback, 626 * and this method will be immediately called after {@link #onConfigured}. 627 * 628 * <p>If the session runs out of capture requests to process and calls {@link #onReady}, 629 * then this callback will be invoked again once new requests are submitted for capture.</p> 630 * 631 * @param session the session returned by {@link CameraDevice#createCaptureSession} 632 */ 633 public void onActive(@NonNull CameraCaptureSession session) { 634 // default empty implementation 635 } 636 637 /** 638 * This method is called when the session is closed. 639 * 640 * <p>A session is closed when a new session is created by the parent camera device, 641 * or when the parent camera device is closed (either by the user closing the device, 642 * or due to a camera device disconnection or fatal error).</p> 643 * 644 * <p>Once a session is closed, all methods on it will throw an IllegalStateException, and 645 * any repeating requests or bursts are stopped (as if {@link #stopRepeating()} was called). 646 * However, any in-progress capture requests submitted to the session will be completed 647 * as normal.</p> 648 * 649 * @param session the session returned by {@link CameraDevice#createCaptureSession} 650 */ 651 public void onClosed(@NonNull CameraCaptureSession session) { 652 // default empty implementation 653 } 654 655 /** 656 * This method is called when the buffer pre-allocation for an output Surface is complete. 657 * 658 * <p>Buffer pre-allocation for an output Surface is started by the {@link #prepare} call. 659 * While allocation is underway, the Surface must not be used as a capture target. 660 * Once this callback fires, the output Surface provided can again be used as a target for 661 * a capture request.</p> 662 * 663 * <p>In case of a error during pre-allocation (such as running out of suitable memory), 664 * this callback is still invoked after the error is encountered, though some buffers may 665 * not have been successfully pre-allocated.</p> 666 * 667 * @param session the session returned by {@link CameraDevice#createCaptureSession} 668 * @param surface the Surface that was used with the {@link #prepare} call. 669 */ 670 public void onSurfacePrepared(@NonNull CameraCaptureSession session, 671 @NonNull Surface surface) { 672 // default empty implementation 673 } 674 } 675 676 /** 677 * Temporary for migrating to Callback naming 678 * @hide 679 */ 680 public static abstract class StateListener extends StateCallback { 681 } 682 683 /** 684 * <p>A callback object for tracking the progress of a {@link CaptureRequest} submitted to the 685 * camera device.</p> 686 * 687 * <p>This callback is invoked when a request triggers a capture to start, 688 * and when the capture is complete. In case on an error capturing an image, 689 * the error method is triggered instead of the completion method.</p> 690 * 691 * @see #capture 692 * @see #captureBurst 693 * @see #setRepeatingRequest 694 * @see #setRepeatingBurst 695 */ 696 public static abstract class CaptureCallback { 697 698 /** 699 * This constant is used to indicate that no images were captured for 700 * the request. 701 * 702 * @hide 703 */ 704 public static final int NO_FRAMES_CAPTURED = -1; 705 706 /** 707 * This method is called when the camera device has started capturing 708 * the output image for the request, at the beginning of image exposure, or 709 * when the camera device has started processing an input image for a reprocess 710 * request. 711 * 712 * <p>For a regular capture request, this callback is invoked right as 713 * the capture of a frame begins, so it is the most appropriate time 714 * for playing a shutter sound, or triggering UI indicators of capture.</p> 715 * 716 * <p>The request that is being used for this capture is provided, along 717 * with the actual timestamp for the start of exposure. For a reprocess 718 * request, this timestamp will be the input image's start of exposure 719 * which matches {@link CaptureResult#SENSOR_TIMESTAMP the result timestamp field} 720 * of the {@link TotalCaptureResult} that was used to 721 * {@link CameraDevice#createReprocessCaptureRequest create the reprocess request}. 722 * This timestamp matches the timestamps that will be 723 * included in {@link CaptureResult#SENSOR_TIMESTAMP the result timestamp field}, 724 * and in the buffers sent to each output Surface. These buffer 725 * timestamps are accessible through, for example, 726 * {@link android.media.Image#getTimestamp() Image.getTimestamp()} or 727 * {@link android.graphics.SurfaceTexture#getTimestamp()}. 728 * The frame number included is equal to the frame number that will be included in 729 * {@link CaptureResult#getFrameNumber}.</p> 730 * 731 * <p>For the simplest way to play a shutter sound camera shutter or a 732 * video recording start/stop sound, see the 733 * {@link android.media.MediaActionSound} class.</p> 734 * 735 * <p>The default implementation of this method does nothing.</p> 736 * 737 * @param session the session returned by {@link CameraDevice#createCaptureSession} 738 * @param request the request for the capture that just begun 739 * @param timestamp the timestamp at start of capture for a regular request, or 740 * the timestamp at the input image's start of capture for a 741 * reprocess request, in nanoseconds. 742 * @param frameNumber the frame number for this capture 743 * 744 * @see android.media.MediaActionSound 745 */ 746 public void onCaptureStarted(@NonNull CameraCaptureSession session, 747 @NonNull CaptureRequest request, long timestamp, long frameNumber) { 748 // Temporary trampoline for API change transition 749 onCaptureStarted(session, request, timestamp); 750 } 751 752 /** 753 * Temporary for API change transition 754 * @hide 755 */ 756 public void onCaptureStarted(CameraCaptureSession session, 757 CaptureRequest request, long timestamp) { 758 // default empty implementation 759 } 760 761 /** 762 * This method is called when some results from an image capture are 763 * available. 764 * 765 * <p>The result provided here will contain some subset of the fields of 766 * a full result. Multiple onCapturePartial calls may happen per 767 * capture; a given result field will only be present in one partial 768 * capture at most. The final onCaptureCompleted call will always 769 * contain all the fields, whether onCapturePartial was called or 770 * not.</p> 771 * 772 * <p>The default implementation of this method does nothing.</p> 773 * 774 * @param session the session returned by {@link CameraDevice#createCaptureSession} 775 * @param request The request that was given to the CameraDevice 776 * @param result The partial output metadata from the capture, which 777 * includes a subset of the CaptureResult fields. 778 * 779 * @see #capture 780 * @see #captureBurst 781 * @see #setRepeatingRequest 782 * @see #setRepeatingBurst 783 * 784 * @hide 785 */ 786 public void onCapturePartial(CameraCaptureSession session, 787 CaptureRequest request, CaptureResult result) { 788 // default empty implementation 789 } 790 791 /** 792 * This method is called when an image capture makes partial forward progress; some 793 * (but not all) results from an image capture are available. 794 * 795 * <p>The result provided here will contain some subset of the fields of 796 * a full result. Multiple {@link #onCaptureProgressed} calls may happen per 797 * capture; a given result field will only be present in one partial 798 * capture at most. The final {@link #onCaptureCompleted} call will always 799 * contain all the fields (in particular, the union of all the fields of all 800 * the partial results composing the total result).</p> 801 * 802 * <p>For each request, some result data might be available earlier than others. The typical 803 * delay between each partial result (per request) is a single frame interval. 804 * For performance-oriented use-cases, applications should query the metadata they need 805 * to make forward progress from the partial results and avoid waiting for the completed 806 * result.</p> 807 * 808 * <p>Each request will generate at least {@code 1} partial results, and at most 809 * {@link CameraCharacteristics#REQUEST_PARTIAL_RESULT_COUNT} partial results.</p> 810 * 811 * <p>Depending on the request settings, the number of partial results per request 812 * will vary, although typically the partial count could be the same as long as the 813 * camera device subsystems enabled stay the same.</p> 814 * 815 * <p>The default implementation of this method does nothing.</p> 816 * 817 * @param session the session returned by {@link CameraDevice#createCaptureSession} 818 * @param request The request that was given to the CameraDevice 819 * @param partialResult The partial output metadata from the capture, which 820 * includes a subset of the {@link TotalCaptureResult} fields. 821 * 822 * @see #capture 823 * @see #captureBurst 824 * @see #setRepeatingRequest 825 * @see #setRepeatingBurst 826 */ 827 public void onCaptureProgressed(@NonNull CameraCaptureSession session, 828 @NonNull CaptureRequest request, @NonNull CaptureResult partialResult) { 829 // default empty implementation 830 } 831 832 /** 833 * This method is called when an image capture has fully completed and all the 834 * result metadata is available. 835 * 836 * <p>This callback will always fire after the last {@link #onCaptureProgressed}; 837 * in other words, no more partial results will be delivered once the completed result 838 * is available.</p> 839 * 840 * <p>For performance-intensive use-cases where latency is a factor, consider 841 * using {@link #onCaptureProgressed} instead.</p> 842 * 843 * <p>The default implementation of this method does nothing.</p> 844 * 845 * @param session the session returned by {@link CameraDevice#createCaptureSession} 846 * @param request The request that was given to the CameraDevice 847 * @param result The total output metadata from the capture, including the 848 * final capture parameters and the state of the camera system during 849 * capture. 850 * 851 * @see #capture 852 * @see #captureBurst 853 * @see #setRepeatingRequest 854 * @see #setRepeatingBurst 855 */ 856 public void onCaptureCompleted(@NonNull CameraCaptureSession session, 857 @NonNull CaptureRequest request, @NonNull TotalCaptureResult result) { 858 // default empty implementation 859 } 860 861 /** 862 * This method is called instead of {@link #onCaptureCompleted} when the 863 * camera device failed to produce a {@link CaptureResult} for the 864 * request. 865 * 866 * <p>Other requests are unaffected, and some or all image buffers from 867 * the capture may have been pushed to their respective output 868 * streams.</p> 869 * 870 * <p>The default implementation of this method does nothing.</p> 871 * 872 * @param session 873 * The session returned by {@link CameraDevice#createCaptureSession} 874 * @param request 875 * The request that was given to the CameraDevice 876 * @param failure 877 * The output failure from the capture, including the failure reason 878 * and the frame number. 879 * 880 * @see #capture 881 * @see #captureBurst 882 * @see #setRepeatingRequest 883 * @see #setRepeatingBurst 884 */ 885 public void onCaptureFailed(@NonNull CameraCaptureSession session, 886 @NonNull CaptureRequest request, @NonNull CaptureFailure failure) { 887 // default empty implementation 888 } 889 890 /** 891 * This method is called independently of the others in CaptureCallback, 892 * when a capture sequence finishes and all {@link CaptureResult} 893 * or {@link CaptureFailure} for it have been returned via this listener. 894 * 895 * <p>In total, there will be at least one result/failure returned by this listener 896 * before this callback is invoked. If the capture sequence is aborted before any 897 * requests have been processed, {@link #onCaptureSequenceAborted} is invoked instead.</p> 898 * 899 * <p>The default implementation does nothing.</p> 900 * 901 * @param session 902 * The session returned by {@link CameraDevice#createCaptureSession} 903 * @param sequenceId 904 * A sequence ID returned by the {@link #capture} family of functions. 905 * @param frameNumber 906 * The last frame number (returned by {@link CaptureResult#getFrameNumber} 907 * or {@link CaptureFailure#getFrameNumber}) in the capture sequence. 908 * 909 * @see CaptureResult#getFrameNumber() 910 * @see CaptureFailure#getFrameNumber() 911 * @see CaptureResult#getSequenceId() 912 * @see CaptureFailure#getSequenceId() 913 * @see #onCaptureSequenceAborted 914 */ 915 public void onCaptureSequenceCompleted(@NonNull CameraCaptureSession session, 916 int sequenceId, long frameNumber) { 917 // default empty implementation 918 } 919 920 /** 921 * This method is called independently of the others in CaptureCallback, 922 * when a capture sequence aborts before any {@link CaptureResult} 923 * or {@link CaptureFailure} for it have been returned via this listener. 924 * 925 * <p>Due to the asynchronous nature of the camera device, not all submitted captures 926 * are immediately processed. It is possible to clear out the pending requests 927 * by a variety of operations such as {@link CameraCaptureSession#stopRepeating} or 928 * {@link CameraCaptureSession#abortCaptures}. When such an event happens, 929 * {@link #onCaptureSequenceCompleted} will not be called.</p> 930 * 931 * <p>The default implementation does nothing.</p> 932 * 933 * @param session 934 * The session returned by {@link CameraDevice#createCaptureSession} 935 * @param sequenceId 936 * A sequence ID returned by the {@link #capture} family of functions. 937 * 938 * @see CaptureResult#getFrameNumber() 939 * @see CaptureFailure#getFrameNumber() 940 * @see CaptureResult#getSequenceId() 941 * @see CaptureFailure#getSequenceId() 942 * @see #onCaptureSequenceCompleted 943 */ 944 public void onCaptureSequenceAborted(@NonNull CameraCaptureSession session, 945 int sequenceId) { 946 // default empty implementation 947 } 948 } 949 950 /** 951 * Temporary for migrating to Callback naming 952 * @hide 953 */ 954 public static abstract class CaptureListener extends CaptureCallback { 955 } 956 957 } 958
