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/*
 * Copyright 2015 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package android.hardware.camera2;

import android.annotation.NonNull;
import android.hardware.camera2.params.StreamConfigurationMap;

import java.util.List;


A constrained high speed capture session for a CameraDevice, used for capturing high speed images from the CameraDevice for high speed video recording use case. 
 A CameraHighSpeedCaptureSession is created by providing a set of target output surfaces to CameraDevice.createConstrainedHighSpeedCaptureSession, Once created, the session is active until a new session is created by the camera device, or the camera device is closed. 


 An active high speed capture session is a specialized capture session that is only targeted at high speed video recording (>=120fps) use case if the camera device supports high speed video capability (i.e., CameraCharacteristics.REQUEST_AVAILABLE_CAPABILITIES contains CameraMetadata.REQUEST_AVAILABLE_CAPABILITIES_CONSTRAINED_HIGH_SPEED_VIDEO). It only accepts request lists created via createHighSpeedRequestList, and the request list can only be submitted to this session via captureBurst, or setRepeatingBurst. See CameraDevice.createConstrainedHighSpeedCaptureSession for more details of the limitations. 


 Creating a session is an expensive operation and can take several hundred milliseconds, since it requires configuring the camera device's internal pipelines and allocating memory buffers for sending images to the desired targets. Therefore the setup is done asynchronously, and CameraDevice.createConstrainedHighSpeedCaptureSession will send the ready-to-use CameraCaptureSession to the provided listener's StateCallback.onConfigured callback. If configuration cannot be completed, then the StateCallback.onConfigureFailed is called, and the session will not become active. 



 If a new session is created by the camera device, then the previous session is closed, and its associated onClosed callback will be invoked. All of the session methods will throw an IllegalStateException if called once the session is closed. 


 A closed session clears any repeating requests (as if CameraCaptureSession.stopRepeating had been called), but will still complete all of its in-progress capture requests as normal, before a newly created session takes over and reconfigures the camera device. 


/**
 * A constrained high speed capture session for a {@link CameraDevice}, used for capturing high
 * speed images from the {@link CameraDevice} for high speed video recording use case.
 * <p>
 * A CameraHighSpeedCaptureSession is created by providing a set of target output surfaces to
 * {@link CameraDevice#createConstrainedHighSpeedCaptureSession}, Once created, the session is
 * active until a new session is created by the camera device, or the camera device is closed.
 * </p>
 * <p>
 * An active high speed capture session is a specialized capture session that is only targeted at
 * high speed video recording (>=120fps) use case if the camera device supports high speed video
 * capability (i.e., {@link CameraCharacteristics#REQUEST_AVAILABLE_CAPABILITIES} contains
 * {@link CameraMetadata#REQUEST_AVAILABLE_CAPABILITIES_CONSTRAINED_HIGH_SPEED_VIDEO}). It only
 * accepts request lists created via {@link #createHighSpeedRequestList}, and the request list can
 * only be submitted to this session via {@link CameraCaptureSession#captureBurst captureBurst}, or
 * {@link CameraCaptureSession#setRepeatingBurst setRepeatingBurst}. See
 * {@link CameraDevice#createConstrainedHighSpeedCaptureSession} for more details of the
 * limitations.
 * </p>
 * <p>
 * Creating a session is an expensive operation and can take several hundred milliseconds, since it
 * requires configuring the camera device's internal pipelines and allocating memory buffers for
 * sending images to the desired targets. Therefore the setup is done asynchronously, and
 * {@link CameraDevice#createConstrainedHighSpeedCaptureSession} will send the ready-to-use
 * CameraCaptureSession to the provided listener's
 * {@link CameraCaptureSession.StateCallback#onConfigured} callback. If configuration cannot be
 * completed, then the {@link CameraCaptureSession.StateCallback#onConfigureFailed} is called, and
 * the session will not become active.
 * </p>
 * <!--
 * <p>
 * Any capture requests (repeating or non-repeating) submitted before the session is ready will be
 * queued up and will begin capture once the session becomes ready. In case the session cannot be
 * configured and {@link CameraCaptureSession.StateCallback#onConfigureFailed onConfigureFailed} is
 * called, all queued capture requests are discarded.  </p>
 * -->
 * <p>
 * If a new session is created by the camera device, then the previous session is closed, and its
 * associated {@link CameraCaptureSession.StateCallback#onClosed onClosed} callback will be
 * invoked. All of the session methods will throw an IllegalStateException if called once the
 * session is closed.
 * </p>
 * <p>
 * A closed session clears any repeating requests (as if {@link #stopRepeating} had been called),
 * but will still complete all of its in-progress capture requests as normal, before a newly created
 * session takes over and reconfigures the camera device.
 * </p>
 */
public abstract class CameraConstrainedHighSpeedCaptureSession extends CameraCaptureSession {

    
Create a unmodifiable list of requests that is suitable for constrained high speed capture
session streaming.


High speed video streaming creates significant performance pressure on the camera device, so to achieve efficient high speed streaming, the camera device may have to aggregate multiple frames together. This means requests must be sent in batched groups, with all requests sharing the same settings. This method takes the list of output target Surfaces (subject to the output Surface requirements specified by the constrained high speed session) and a request, and generates a request list that has the same controls for each request. The input request must contain the target output Surfaces and target high speed FPS range that is one of the StreamConfigurationMap.getHighSpeedVideoFpsRangesFor for the Surface size.


If both preview and recording Surfaces are specified in the request, the target FPS range in the input request must be a fixed frame rate FPS range, where the minimal FPS == maximum FPS. The created request list will contain a interleaved request pattern such that the preview output FPS is at least 30fps, the recording output FPS is maximum FPS of the requested FPS range. The application can submit this request list directly to an active high speed capture session to achieve high speed video recording. When only preview or recording Surface is specified, this method will return a list of request that have the same controls and output targets for all requests.


Submitting a request list created by this method to a normal capture session will result in an IllegalArgumentException if the high speed FPS range is not supported by CameraCharacteristics.CONTROL_AE_AVAILABLE_TARGET_FPS_RANGES.


Params:
  • request – The high speed capture request that will be used to generate the high speed
               request list.
Throws:
  • IllegalArgumentException – if the set of output Surfaces in the request do not meet the
                                 high speed video capability requirements, or the camera
                                 device doesn't support high speed video capability, or the
                                 request doesn't meet the high speed video capability
                                 requirements, or the request doesn't contain the required
                                 controls for high speed capture.
  • CameraAccessException – if the camera device is no longer connected or has
                              encountered a fatal error
  • IllegalStateException – if the camera device has been closed
See Also:
Returns:A unmodifiable CaptureRequest list that is suitable for constrained high speed
        capture.
/**
     * <p>Create a unmodifiable list of requests that is suitable for constrained high speed capture
     * session streaming.</p>
     *
     * <p>High speed video streaming creates significant performance pressure on the camera device,
     * so to achieve efficient high speed streaming, the camera device may have to aggregate
     * multiple frames together. This means requests must be sent in batched groups, with all
     * requests sharing the same settings. This method takes the list of output target
     * Surfaces (subject to the output Surface requirements specified by the constrained high speed
     * session) and a {@link CaptureRequest request}, and generates a request list that has the same
     * controls for each request. The input {@link CaptureRequest request} must contain the target
     * output Surfaces and target high speed FPS range that is one of the
     * {@link StreamConfigurationMap#getHighSpeedVideoFpsRangesFor} for the Surface size.</p>
     *
     * <p>If both preview and recording Surfaces are specified in the {@code request}, the
     * {@link CaptureRequest#CONTROL_AE_TARGET_FPS_RANGE target FPS range} in the input
     * {@link CaptureRequest request} must be a fixed frame rate FPS range, where the
     * {@link android.util.Range#getLower minimal FPS} ==
     * {@link android.util.Range#getUpper() maximum FPS}. The created request list will contain
     * a interleaved request pattern such that the preview output FPS is at least 30fps, the
     * recording output FPS is {@link android.util.Range#getUpper() maximum FPS} of the requested
     * FPS range. The application can submit this request list directly to an active high speed
     * capture session to achieve high speed video recording. When only preview or recording
     * Surface is specified, this method will return a list of request that have the same controls
     * and output targets for all requests.</p>
     *
     * <p>Submitting a request list created by this method to a normal capture session will result
     * in an {@link IllegalArgumentException} if the high speed
     * {@link CaptureRequest#CONTROL_AE_TARGET_FPS_RANGE FPS range} is not supported by
     * {@link CameraCharacteristics#CONTROL_AE_AVAILABLE_TARGET_FPS_RANGES}.</p>
     *
     * @param request The high speed capture request that will be used to generate the high speed
     *                request list.
     * @return A unmodifiable CaptureRequest list that is suitable for constrained high speed
     *         capture.
     *
     * @throws IllegalArgumentException if the set of output Surfaces in the request do not meet the
     *                                  high speed video capability requirements, or the camera
     *                                  device doesn't support high speed video capability, or the
     *                                  request doesn't meet the high speed video capability
     *                                  requirements, or the request doesn't contain the required
     *                                  controls for high speed capture.
     * @throws CameraAccessException if the camera device is no longer connected or has
     *                               encountered a fatal error
     * @throws IllegalStateException if the camera device has been closed
     *
     * @see CameraDevice#createConstrainedHighSpeedCaptureSession
     * @see CaptureRequest#CONTROL_AE_TARGET_FPS_RANGE
     * @see android.hardware.camera2.params.StreamConfigurationMap#getHighSpeedVideoSizes
     * @see android.hardware.camera2.params.StreamConfigurationMap#getHighSpeedVideoFpsRangesFor
     * @see CameraCharacteristics#REQUEST_AVAILABLE_CAPABILITIES
     * @see CameraMetadata#REQUEST_AVAILABLE_CAPABILITIES_CONSTRAINED_HIGH_SPEED_VIDEO
     */
    @NonNull
    public abstract List<CaptureRequest> createHighSpeedRequestList(
            @NonNull CaptureRequest request) throws CameraAccessException;

}