public final class

VideoCapture

extends UseCase

 java.lang.Object

androidx.camera.core.UseCase

↳androidx.camera.core.VideoCapture

Gradle dependencies

compile group: 'androidx.camera', name: 'camera-core', version: '1.2.0-alpha01'

  • groupId: androidx.camera
  • artifactId: camera-core
  • version: 1.2.0-alpha01

Artifact androidx.camera:camera-core:1.2.0-alpha01 it located at Google repository (https://maven.google.com/)

Overview

A use case for taking a video.

This class is designed for simple video capturing. It gives basic configuration of the recorded video such as resolution and file format.

Summary

Fields
public static final VideoCapture.DefaultsDEFAULT_CONFIG

Provides a static configuration with implementation-agnostic options.

public static final intERROR_ENCODER

An error occurred with encoder state, either when trying to change state or when an unexpected state change occurred.

public static final intERROR_FILE_IO

An error indicating the file saving operations.

public static final intERROR_INVALID_CAMERA

An error indicating this VideoCapture is not bound to a camera.

public static final intERROR_MUXER

An error with muxer state such as during creation or when stopping.

public static final intERROR_RECORDING_IN_PROGRESS

An error indicating start recording was called when video recording is still in progress.

public static final intERROR_RECORDING_TOO_SHORT

An error indicating the video file is too short.

public static final intERROR_UNKNOWN

An unknown error occurred.

public final java.util.concurrent.atomic.AtomicBooleanmIsFirstAudioSampleWrite

public final java.util.concurrent.atomic.AtomicBooleanmIsFirstVideoKeyFrameWrite

For record the first sample written time.

Methods
public UseCaseConfig<UseCase>getDefaultConfig(boolean applyDefaultConfig, UseCaseConfigFactory factory)

public UseCaseConfig.Builder<UseCase, UseCaseConfig, java.lang.Object>getUseCaseConfigBuilder(Config config)

public voidonAttached()

public voidonDetached()

public voidonStateDetached()

protected SizeonSuggestedResolutionUpdated(Size suggestedResolution)

public voidsetTargetRotation(int rotation)

Sets the desired rotation of the output video.

public voidstartRecording(VideoCapture.OutputFileOptions outputFileOptions, java.util.concurrent.Executor executor, VideoCapture.OnVideoSavedCallback callback)

Starts recording video, which continues until VideoCapture.stopRecording() is called.

public voidstopRecording()

Stops recording video, this must be called after VideoCapture.startRecording(VideoCapture.OutputFileOptions, Executor, VideoCapture.OnVideoSavedCallback) is called.

from UseCasegetAppTargetRotation, getAttachedSurfaceResolution, getCamera, getCameraControl, getCameraId, getCurrentConfig, getImageFormat, getName, getRelativeRotation, getResolutionInfo, getResolutionInfoInternal, getSessionConfig, getTargetRotationInternal, getViewPortCropRect, isCurrentCamera, mergeConfigs, notifyActive, notifyInactive, notifyReset, notifyState, notifyUpdated, onAttach, onCameraControlReady, onDetach, onMergeConfig, onStateAttached, setSensorToBufferTransformMatrix, setTargetRotationInternal, setViewPortCropRect, updateSessionConfig, updateSuggestedResolution
from java.lang.Objectclone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Fields

public static final int ERROR_UNKNOWN

An unknown error occurred.

See message parameter in onError callback or log for more details.

public static final int ERROR_ENCODER

An error occurred with encoder state, either when trying to change state or when an unexpected state change occurred.

public static final int ERROR_MUXER

An error with muxer state such as during creation or when stopping.

public static final int ERROR_RECORDING_IN_PROGRESS

An error indicating start recording was called when video recording is still in progress.

public static final int ERROR_FILE_IO

An error indicating the file saving operations.

public static final int ERROR_INVALID_CAMERA

An error indicating this VideoCapture is not bound to a camera.

public static final int ERROR_RECORDING_TOO_SHORT

An error indicating the video file is too short.

The output file will be deleted if the OutputFileOptions is backed by File or uri.

public static final VideoCapture.Defaults DEFAULT_CONFIG

Provides a static configuration with implementation-agnostic options.

public final java.util.concurrent.atomic.AtomicBoolean mIsFirstVideoKeyFrameWrite

For record the first sample written time.

public final java.util.concurrent.atomic.AtomicBoolean mIsFirstAudioSampleWrite

Methods

public UseCaseConfig<UseCase> getDefaultConfig(boolean applyDefaultConfig, UseCaseConfigFactory factory)

public void onAttached()

protected Size onSuggestedResolutionUpdated(Size suggestedResolution)

public void startRecording(VideoCapture.OutputFileOptions outputFileOptions, java.util.concurrent.Executor executor, VideoCapture.OnVideoSavedCallback callback)

Starts recording video, which continues until VideoCapture.stopRecording() is called.

StartRecording() is asynchronous. User needs to check if any error occurs by setting the VideoCapture.OnVideoSavedCallback.onError(int, String, Throwable).

Parameters:

outputFileOptions: Location to save the video capture
executor: The executor in which the callback methods will be run.
callback: Callback for when the recorded video saving completion or failure.

public void stopRecording()

Stops recording video, this must be called after VideoCapture.startRecording(VideoCapture.OutputFileOptions, Executor, VideoCapture.OnVideoSavedCallback) is called.

stopRecording() is asynchronous API. User need to check if VideoCapture.OnVideoSavedCallback or VideoCapture.OnVideoSavedCallback.onError(int, String, Throwable) be called before startRecording.

public void onDetached()

public UseCaseConfig.Builder<UseCase, UseCaseConfig, java.lang.Object> getUseCaseConfigBuilder(Config config)

public void onStateDetached()

public void setTargetRotation(int rotation)

Sets the desired rotation of the output video.

In most cases this should be set to the current rotation returned by Display.

Parameters:

rotation: Desired rotation of the output video.

Source

/*
 * Copyright (C) 2019 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 androidx.camera.core;

import static androidx.camera.core.impl.ImageOutputConfig.OPTION_DEFAULT_RESOLUTION;
import static androidx.camera.core.impl.ImageOutputConfig.OPTION_MAX_RESOLUTION;
import static androidx.camera.core.impl.ImageOutputConfig.OPTION_SUPPORTED_RESOLUTIONS;
import static androidx.camera.core.impl.ImageOutputConfig.OPTION_TARGET_ASPECT_RATIO;
import static androidx.camera.core.impl.ImageOutputConfig.OPTION_TARGET_RESOLUTION;
import static androidx.camera.core.impl.ImageOutputConfig.OPTION_TARGET_ROTATION;
import static androidx.camera.core.impl.UseCaseConfig.OPTION_CAMERA_SELECTOR;
import static androidx.camera.core.impl.UseCaseConfig.OPTION_CAPTURE_CONFIG_UNPACKER;
import static androidx.camera.core.impl.UseCaseConfig.OPTION_DEFAULT_CAPTURE_CONFIG;
import static androidx.camera.core.impl.UseCaseConfig.OPTION_DEFAULT_SESSION_CONFIG;
import static androidx.camera.core.impl.UseCaseConfig.OPTION_SESSION_CONFIG_UNPACKER;
import static androidx.camera.core.impl.UseCaseConfig.OPTION_SURFACE_OCCUPANCY_PRIORITY;
import static androidx.camera.core.impl.VideoCaptureConfig.OPTION_AUDIO_BIT_RATE;
import static androidx.camera.core.impl.VideoCaptureConfig.OPTION_AUDIO_CHANNEL_COUNT;
import static androidx.camera.core.impl.VideoCaptureConfig.OPTION_AUDIO_MIN_BUFFER_SIZE;
import static androidx.camera.core.impl.VideoCaptureConfig.OPTION_AUDIO_SAMPLE_RATE;
import static androidx.camera.core.impl.VideoCaptureConfig.OPTION_BIT_RATE;
import static androidx.camera.core.impl.VideoCaptureConfig.OPTION_INTRA_FRAME_INTERVAL;
import static androidx.camera.core.impl.VideoCaptureConfig.OPTION_VIDEO_FRAME_RATE;
import static androidx.camera.core.internal.TargetConfig.OPTION_TARGET_CLASS;
import static androidx.camera.core.internal.TargetConfig.OPTION_TARGET_NAME;
import static androidx.camera.core.internal.ThreadConfig.OPTION_BACKGROUND_EXECUTOR;
import static androidx.camera.core.internal.UseCaseEventConfig.OPTION_USE_CASE_EVENT_CALLBACK;

import android.Manifest;
import android.content.ContentResolver;
import android.content.ContentValues;
import android.location.Location;
import android.media.AudioFormat;
import android.media.AudioRecord;
import android.media.CamcorderProfile;
import android.media.MediaCodec;
import android.media.MediaCodec.BufferInfo;
import android.media.MediaCodecInfo;
import android.media.MediaCodecInfo.CodecCapabilities;
import android.media.MediaFormat;
import android.media.MediaMuxer;
import android.media.MediaRecorder.AudioSource;
import android.net.Uri;
import android.os.Build;
import android.os.Bundle;
import android.os.Handler;
import android.os.HandlerThread;
import android.os.Looper;
import android.os.ParcelFileDescriptor;
import android.provider.MediaStore;
import android.util.Pair;
import android.util.Size;
import android.view.Display;
import android.view.Surface;

import androidx.annotation.DoNotInline;
import androidx.annotation.GuardedBy;
import androidx.annotation.IntDef;
import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.annotation.RequiresApi;
import androidx.annotation.RequiresPermission;
import androidx.annotation.RestrictTo;
import androidx.annotation.RestrictTo.Scope;
import androidx.annotation.UiThread;
import androidx.annotation.VisibleForTesting;
import androidx.camera.core.impl.CameraInternal;
import androidx.camera.core.impl.CaptureConfig;
import androidx.camera.core.impl.Config;
import androidx.camera.core.impl.ConfigProvider;
import androidx.camera.core.impl.DeferrableSurface;
import androidx.camera.core.impl.ImageOutputConfig;
import androidx.camera.core.impl.ImageOutputConfig.RotationValue;
import androidx.camera.core.impl.ImmediateSurface;
import androidx.camera.core.impl.MutableConfig;
import androidx.camera.core.impl.MutableOptionsBundle;
import androidx.camera.core.impl.OptionsBundle;
import androidx.camera.core.impl.SessionConfig;
import androidx.camera.core.impl.UseCaseConfig;
import androidx.camera.core.impl.UseCaseConfigFactory;
import androidx.camera.core.impl.VideoCaptureConfig;
import androidx.camera.core.impl.utils.executor.CameraXExecutors;
import androidx.camera.core.internal.ThreadConfig;
import androidx.camera.core.internal.utils.VideoUtil;
import androidx.concurrent.futures.CallbackToFutureAdapter;
import androidx.concurrent.futures.CallbackToFutureAdapter.Completer;
import androidx.core.util.Preconditions;

import com.google.common.util.concurrent.ListenableFuture;

import java.io.File;
import java.io.FileDescriptor;
import java.io.IOException;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.nio.ByteBuffer;
import java.util.List;
import java.util.UUID;
import java.util.concurrent.Executor;
import java.util.concurrent.RejectedExecutionException;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.atomic.AtomicReference;

/**
 * A use case for taking a video.
 *
 * <p>This class is designed for simple video capturing. It gives basic configuration of the
 * recorded video such as resolution and file format.
 *
 * @hide
 */
@RequiresApi(21) // TODO(b/200306659): Remove and replace with annotation on package-info.java
@RestrictTo(Scope.LIBRARY_GROUP)
public final class VideoCapture extends UseCase {

    ////////////////////////////////////////////////////////////////////////////////////////////
    // [UseCase lifetime constant] - Stays constant for the lifetime of the UseCase. Which means
    // they could be created in the constructor.
    ////////////////////////////////////////////////////////////////////////////////////////////

    /**
     * An unknown error occurred.
     *
     * <p>See message parameter in onError callback or log for more details.
     */
    public static final int ERROR_UNKNOWN = 0;
    /**
     * An error occurred with encoder state, either when trying to change state or when an
     * unexpected state change occurred.
     */
    public static final int ERROR_ENCODER = 1;
    /** An error with muxer state such as during creation or when stopping. */
    public static final int ERROR_MUXER = 2;
    /**
     * An error indicating start recording was called when video recording is still in progress.
     */
    public static final int ERROR_RECORDING_IN_PROGRESS = 3;
    /**
     * An error indicating the file saving operations.
     */
    public static final int ERROR_FILE_IO = 4;
    /**
     * An error indicating this VideoCapture is not bound to a camera.
     */
    public static final int ERROR_INVALID_CAMERA = 5;
    /**
     * An error indicating the video file is too short.
     * <p> The output file will be deleted if the OutputFileOptions is backed by File or uri.
     */
    public static final int ERROR_RECORDING_TOO_SHORT = 6;

    /**
     * Provides a static configuration with implementation-agnostic options.
     *
     * @hide
     */
    @RestrictTo(Scope.LIBRARY_GROUP)
    public static final Defaults DEFAULT_CONFIG = new Defaults();
    private static final String TAG = "VideoCapture";
    /** Amount of time to wait for dequeuing a buffer from the videoEncoder. */
    private static final int DEQUE_TIMEOUT_USEC = 10000;
    /** Android preferred mime type for AVC video. */
    private static final String VIDEO_MIME_TYPE = "video/avc";
    private static final String AUDIO_MIME_TYPE = "audio/mp4a-latm";
    /** Camcorder profiles quality list */
    private static final int[] CamcorderQuality = {
            CamcorderProfile.QUALITY_2160P,
            CamcorderProfile.QUALITY_1080P,
            CamcorderProfile.QUALITY_720P,
            CamcorderProfile.QUALITY_480P
    };

    private final BufferInfo mVideoBufferInfo = new BufferInfo();
    private final Object mMuxerLock = new Object();
    private final AtomicBoolean mEndOfVideoStreamSignal = new AtomicBoolean(true);
    private final AtomicBoolean mEndOfAudioStreamSignal = new AtomicBoolean(true);
    private final AtomicBoolean mEndOfAudioVideoSignal = new AtomicBoolean(true);
    private final BufferInfo mAudioBufferInfo = new BufferInfo();
    /** For record the first sample written time. */
    @VisibleForTesting(otherwise = VisibleForTesting.PRIVATE)
    public final AtomicBoolean mIsFirstVideoKeyFrameWrite = new AtomicBoolean(false);
    @VisibleForTesting(otherwise = VisibleForTesting.PRIVATE)
    public final AtomicBoolean mIsFirstAudioSampleWrite = new AtomicBoolean(false);

    ////////////////////////////////////////////////////////////////////////////////////////////
    // [UseCase attached constant] - Is only valid when the UseCase is attached to a camera.
    ////////////////////////////////////////////////////////////////////////////////////////////

    /** Thread on which all encoding occurs. */
    private HandlerThread mVideoHandlerThread;
    private Handler mVideoHandler;
    /** Thread on which audio encoding occurs. */
    private HandlerThread mAudioHandlerThread;
    private Handler mAudioHandler;

    @NonNull
    MediaCodec mVideoEncoder;
    @NonNull
    private MediaCodec mAudioEncoder;
    @Nullable
    private ListenableFuture<Void> mRecordingFuture = null;
    @NonNull
    private SessionConfig.Builder mSessionConfigBuilder = new SessionConfig.Builder();

    ////////////////////////////////////////////////////////////////////////////////////////////
    // [UseCase attached dynamic] - Can change but is only available when the UseCase is attached.
    ////////////////////////////////////////////////////////////////////////////////////////////

    /** The muxer that writes the encoding data to file. */
    @GuardedBy("mMuxerLock")
    private MediaMuxer mMuxer;
    private final AtomicBoolean mMuxerStarted = new AtomicBoolean(false);
    /** The index of the video track used by the muxer. */
    @GuardedBy("mMuxerLock")
    private int mVideoTrackIndex;
    /** The index of the audio track used by the muxer. */
    @GuardedBy("mMuxerLock")
    private int mAudioTrackIndex;
    /** Surface the camera writes to, which the videoEncoder uses as input. */
    Surface mCameraSurface;

    /** audio raw data */
    @Nullable
    private volatile AudioRecord mAudioRecorder;
    private volatile int mAudioBufferSize;
    private volatile boolean mIsRecording = false;
    private int mAudioChannelCount;
    private int mAudioSampleRate;
    private int mAudioBitRate;
    private DeferrableSurface mDeferrableSurface;
    @SuppressWarnings("WeakerAccess") /* synthetic accessor */
    volatile Uri mSavedVideoUri;
    private volatile ParcelFileDescriptor mParcelFileDescriptor;
    private final AtomicBoolean mIsAudioEnabled = new AtomicBoolean(true);

    private VideoEncoderInitStatus mVideoEncoderInitStatus =
            VideoEncoderInitStatus.VIDEO_ENCODER_INIT_STATUS_UNINITIALIZED;
    @Nullable
    private Throwable mVideoEncoderErrorMessage;

    /**
     * Creates a new video capture use case from the given configuration.
     *
     * @param config for this use case instance
     */
    VideoCapture(@NonNull VideoCaptureConfig config) {
        super(config);
    }

    /** Creates a {@link MediaFormat} using parameters from the configuration */
    private static MediaFormat createVideoMediaFormat(VideoCaptureConfig config, Size resolution) {
        MediaFormat format =
                MediaFormat.createVideoFormat(
                        VIDEO_MIME_TYPE, resolution.getWidth(), resolution.getHeight());
        format.setInteger(MediaFormat.KEY_COLOR_FORMAT, CodecCapabilities.COLOR_FormatSurface);
        format.setInteger(MediaFormat.KEY_BIT_RATE, config.getBitRate());
        format.setInteger(MediaFormat.KEY_FRAME_RATE, config.getVideoFrameRate());
        format.setInteger(MediaFormat.KEY_I_FRAME_INTERVAL, config.getIFrameInterval());

        return format;
    }

    /**
     * {@inheritDoc}
     *
     * @hide
     */
    @RestrictTo(Scope.LIBRARY_GROUP)
    @Override
    @Nullable
    public UseCaseConfig<?> getDefaultConfig(boolean applyDefaultConfig,
            @NonNull UseCaseConfigFactory factory) {
        Config captureConfig = factory.getConfig(
                UseCaseConfigFactory.CaptureType.VIDEO_CAPTURE,
                ImageCapture.CAPTURE_MODE_MINIMIZE_LATENCY);

        if (applyDefaultConfig) {
            captureConfig = Config.mergeConfigs(captureConfig, DEFAULT_CONFIG.getConfig());
        }

        return captureConfig == null ? null :
                getUseCaseConfigBuilder(captureConfig).getUseCaseConfig();
    }

    /**
     * {@inheritDoc}
     *
     * @hide
     */
    @SuppressWarnings("WrongConstant")
    @Override
    @RestrictTo(Scope.LIBRARY_GROUP)
    public void onAttached() {
        mVideoHandlerThread = new HandlerThread(CameraXThreads.TAG + "video encoding thread");
        mAudioHandlerThread = new HandlerThread(CameraXThreads.TAG + "audio encoding thread");

        // video thread start
        mVideoHandlerThread.start();
        mVideoHandler = new Handler(mVideoHandlerThread.getLooper());

        // audio thread start
        mAudioHandlerThread.start();
        mAudioHandler = new Handler(mAudioHandlerThread.getLooper());
    }

    /**
     * {@inheritDoc}
     *
     * @hide
     */
    @Override
    @RequiresPermission(Manifest.permission.RECORD_AUDIO)
    @RestrictTo(Scope.LIBRARY_GROUP)
    @NonNull
    protected Size onSuggestedResolutionUpdated(@NonNull Size suggestedResolution) {
        if (mCameraSurface != null) {
            mVideoEncoder.stop();
            mVideoEncoder.release();
            mAudioEncoder.stop();
            mAudioEncoder.release();
            releaseCameraSurface(false);
        }

        try {
            mVideoEncoder = MediaCodec.createEncoderByType(VIDEO_MIME_TYPE);
            mAudioEncoder = MediaCodec.createEncoderByType(AUDIO_MIME_TYPE);
        } catch (IOException e) {
            throw new IllegalStateException("Unable to create MediaCodec due to: " + e.getCause());
        }

        setupEncoder(getCameraId(), suggestedResolution);
        // VideoCapture has to be active to apply SessionConfig's template type.
        notifyActive();
        return suggestedResolution;
    }

    /**
     * Starts recording video, which continues until {@link VideoCapture#stopRecording()} is
     * called.
     *
     * <p>StartRecording() is asynchronous. User needs to check if any error occurs by setting the
     * {@link OnVideoSavedCallback#onError(int, String, Throwable)}.
     *
     * @param outputFileOptions Location to save the video capture
     * @param executor          The executor in which the callback methods will be run.
     * @param callback          Callback for when the recorded video saving completion or failure.
     */
    @SuppressWarnings("ObjectToString")
    @RequiresPermission(Manifest.permission.RECORD_AUDIO)
    public void startRecording(
            @NonNull OutputFileOptions outputFileOptions, @NonNull Executor executor,
            @NonNull OnVideoSavedCallback callback) {
        if (Looper.getMainLooper() != Looper.myLooper()) {
            CameraXExecutors.mainThreadExecutor().execute(() -> startRecording(outputFileOptions,
                    executor, callback));
            return;
        }
        Logger.i(TAG, "startRecording");
        mIsFirstVideoKeyFrameWrite.set(false);
        mIsFirstAudioSampleWrite.set(false);

        OnVideoSavedCallback postListener = new VideoSavedListenerWrapper(executor, callback);

        CameraInternal attachedCamera = getCamera();
        if (attachedCamera == null) {
            // Not bound. Notify callback.
            postListener.onError(ERROR_INVALID_CAMERA,
                    "Not bound to a Camera [" + VideoCapture.this + "]", null);
            return;
        }

        // Check video encoder initialization status, if there is any error happened
        // return error callback directly.
        if (mVideoEncoderInitStatus
                == VideoEncoderInitStatus.VIDEO_ENCODER_INIT_STATUS_INSUFFICIENT_RESOURCE
                || mVideoEncoderInitStatus
                == VideoEncoderInitStatus.VIDEO_ENCODER_INIT_STATUS_INITIALIZED_FAILED
                || mVideoEncoderInitStatus
                == VideoEncoderInitStatus.VIDEO_ENCODER_INIT_STATUS_RESOURCE_RECLAIMED) {
            postListener.onError(ERROR_ENCODER, "Video encoder initialization failed before start"
                    + " recording ", mVideoEncoderErrorMessage);
            return;
        }

        if (!mEndOfAudioVideoSignal.get()) {
            postListener.onError(
                    ERROR_RECORDING_IN_PROGRESS, "It is still in video recording!",
                    null);
            return;
        }

        if (mIsAudioEnabled.get()) {
            try {
                // Audio input start
                if (mAudioRecorder.getState() == AudioRecord.STATE_INITIALIZED) {
                    mAudioRecorder.startRecording();
                }
            } catch (IllegalStateException e) {
                // Disable the audio if the audio input cannot start. And Continue the recording
                // without audio.
                Logger.i(TAG,
                        "AudioRecorder cannot start recording, disable audio." + e.getMessage());
                mIsAudioEnabled.set(false);
                releaseAudioInputResource();
            }

            // Gets the AudioRecorder's state
            if (mAudioRecorder.getRecordingState() != AudioRecord.RECORDSTATE_RECORDING) {
                Logger.i(TAG,
                        "AudioRecorder startRecording failed - incorrect state: "
                                + mAudioRecorder.getRecordingState());
                mIsAudioEnabled.set(false);
                releaseAudioInputResource();
            }
        }

        AtomicReference<Completer<Void>> recordingCompleterRef = new AtomicReference<>();
        mRecordingFuture = CallbackToFutureAdapter.getFuture(
                completer -> {
                    recordingCompleterRef.set(completer);
                    return "startRecording";
                });
        Completer<Void> recordingCompleter =
                Preconditions.checkNotNull(recordingCompleterRef.get());

        mRecordingFuture.addListener(() -> {
            mRecordingFuture = null;
            // Do the setup of the videoEncoder at the end of video recording instead of at the
            // start of recording because it requires attaching a new Surface. This causes a
            // glitch so we don't want that to incur latency at the start of capture.
            if (getCamera() != null) {
                // Ensure the use case is bound. Asynchronous stopping procedure may occur after
                // the use case is unbound, i.e. after onDetached().
                setupEncoder(getCameraId(), getAttachedSurfaceResolution());
                notifyReset();
            }
        }, CameraXExecutors.mainThreadExecutor());

        try {
            // video encoder start
            Logger.i(TAG, "videoEncoder start");
            mVideoEncoder.start();

            // audio encoder start
            if (mIsAudioEnabled.get()) {
                Logger.i(TAG, "audioEncoder start");
                mAudioEncoder.start();
            }
        } catch (IllegalStateException e) {
            recordingCompleter.set(null);
            postListener.onError(ERROR_ENCODER, "Audio/Video encoder start fail", e);
            return;
        }

        try {
            synchronized (mMuxerLock) {
                mMuxer = initMediaMuxer(outputFileOptions);
                Preconditions.checkNotNull(mMuxer);
                mMuxer.setOrientationHint(getRelativeRotation(attachedCamera));

                Metadata metadata = outputFileOptions.getMetadata();
                if (metadata != null && metadata.location != null) {
                    mMuxer.setLocation(
                            (float) metadata.location.getLatitude(),
                            (float) metadata.location.getLongitude());
                }
            }
        } catch (IOException e) {
            recordingCompleter.set(null);
            postListener.onError(ERROR_MUXER, "MediaMuxer creation failed!", e);
            return;
        }

        mEndOfVideoStreamSignal.set(false);
        mEndOfAudioStreamSignal.set(false);
        mEndOfAudioVideoSignal.set(false);
        mIsRecording = true;

        // Attach Surface to repeating request.
        mSessionConfigBuilder.clearSurfaces();
        mSessionConfigBuilder.addSurface(mDeferrableSurface);
        updateSessionConfig(mSessionConfigBuilder.build());
        notifyUpdated();

        if (mIsAudioEnabled.get()) {
            mAudioHandler.post(() -> audioEncode(postListener));
        }

        String cameraId = getCameraId();
        Size resolution = getAttachedSurfaceResolution();
        mVideoHandler.post(
                () -> {
                    boolean errorOccurred = videoEncode(postListener, cameraId, resolution,
                            outputFileOptions);
                    if (!errorOccurred) {
                        postListener.onVideoSaved(new OutputFileResults(mSavedVideoUri));
                        mSavedVideoUri = null;
                    }
                    recordingCompleter.set(null);
                });
    }

    /**
     * Stops recording video, this must be called after {@link
     * VideoCapture#startRecording(OutputFileOptions, Executor, OnVideoSavedCallback)} is
     * called.
     *
     * <p>stopRecording() is asynchronous API. User need to check if {@link
     * OnVideoSavedCallback#onVideoSaved(OutputFileResults)} or
     * {@link OnVideoSavedCallback#onError(int, String, Throwable)} be called
     * before startRecording.
     */
    public void stopRecording() {
        if (Looper.getMainLooper() != Looper.myLooper()) {
            CameraXExecutors.mainThreadExecutor().execute(() -> stopRecording());
            return;
        }
        Logger.i(TAG, "stopRecording");

        mSessionConfigBuilder.clearSurfaces();
        mSessionConfigBuilder.addNonRepeatingSurface(mDeferrableSurface);
        updateSessionConfig(mSessionConfigBuilder.build());
        notifyUpdated();

        if (mIsRecording) {
            if (mIsAudioEnabled.get()) {
                // Stop audio encoder thread, and wait video encoder and muxer stop.
                mEndOfAudioStreamSignal.set(true);
            } else {
                // Audio is disabled, stop video encoder thread directly.
                mEndOfVideoStreamSignal.set(true);
            }
        }
    }

    /**
     * {@inheritDoc}
     *
     * @hide
     */
    @RestrictTo(Scope.LIBRARY_GROUP)
    @Override
    public void onDetached() {
        stopRecording();

        if (mRecordingFuture != null) {
            mRecordingFuture.addListener(() -> releaseResources(),
                    CameraXExecutors.mainThreadExecutor());
        } else {
            releaseResources();
        }
    }

    private void releaseResources() {
        mVideoHandlerThread.quitSafely();

        // audio encoder release
        releaseAudioInputResource();

        if (mCameraSurface != null) {
            releaseCameraSurface(true);
        }
    }

    private void releaseAudioInputResource() {
        mAudioHandlerThread.quitSafely();
        if (mAudioEncoder != null) {
            mAudioEncoder.release();
            mAudioEncoder = null;
        }

        if (mAudioRecorder != null) {
            mAudioRecorder.release();
            mAudioRecorder = null;
        }
    }

    /**
     * {@inheritDoc}
     *
     * @hide
     */
    @NonNull
    @RestrictTo(Scope.LIBRARY_GROUP)
    @Override
    public UseCaseConfig.Builder<?, ?, ?> getUseCaseConfigBuilder(@NonNull Config config) {
        return Builder.fromConfig(config);
    }

    /**
     * {@inheritDoc}
     *
     * @hide
     */
    @RestrictTo(Scope.LIBRARY_GROUP)
    @UiThread
    @Override
    public void onStateDetached() {
        stopRecording();
    }

    @UiThread
    private void releaseCameraSurface(final boolean releaseVideoEncoder) {
        if (mDeferrableSurface == null) {
            return;
        }

        final MediaCodec videoEncoder = mVideoEncoder;

        // Calling close should allow termination future to complete and close the surface with
        // the listener that was added after constructing the DeferrableSurface.
        mDeferrableSurface.close();
        mDeferrableSurface.getTerminationFuture().addListener(
                () -> {
                    if (releaseVideoEncoder && videoEncoder != null) {
                        videoEncoder.release();
                    }
                }, CameraXExecutors.mainThreadExecutor());

        if (releaseVideoEncoder) {
            mVideoEncoder = null;
        }
        mCameraSurface = null;
        mDeferrableSurface = null;
    }

    /**
     * Sets the desired rotation of the output video.
     *
     * <p>In most cases this should be set to the current rotation returned by {@link
     * Display#getRotation()}.
     *
     * @param rotation Desired rotation of the output video.
     */
    public void setTargetRotation(@RotationValue int rotation) {
        setTargetRotationInternal(rotation);
    }

    /**
     * Setup the {@link MediaCodec} for encoding video from a camera {@link Surface} and encoding
     * audio from selected audio source.
     */
    @UiThread
    @SuppressWarnings("WeakerAccess") /* synthetic accessor */
    @RequiresPermission(Manifest.permission.RECORD_AUDIO)
    void setupEncoder(@NonNull String cameraId, @NonNull Size resolution) {
        VideoCaptureConfig config = (VideoCaptureConfig) getCurrentConfig();

        // video encoder setup
        mVideoEncoder.reset();
        mVideoEncoderInitStatus = VideoEncoderInitStatus.VIDEO_ENCODER_INIT_STATUS_UNINITIALIZED;

        // Configures a Video encoder, if there is any exception, will abort follow up actions
        try {
            mVideoEncoder.configure(
                    createVideoMediaFormat(config, resolution), /*surface*/
                    null, /*crypto*/
                    null,
                    MediaCodec.CONFIGURE_FLAG_ENCODE);
        } catch (MediaCodec.CodecException e) {
            int errorCode = 0;
            if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.M) {
                errorCode = Api23Impl.getCodecExceptionErrorCode(e);
                String diagnosticInfo = e.getDiagnosticInfo();
                if (errorCode == MediaCodec.CodecException.ERROR_INSUFFICIENT_RESOURCE) {
                    Logger.i(TAG,
                            "CodecException: code: " + errorCode + " diagnostic: "
                                    + diagnosticInfo);
                    mVideoEncoderInitStatus =
                            VideoEncoderInitStatus.VIDEO_ENCODER_INIT_STATUS_INSUFFICIENT_RESOURCE;
                } else if (errorCode == MediaCodec.CodecException.ERROR_RECLAIMED) {
                    Logger.i(TAG,
                            "CodecException: code: " + errorCode + " diagnostic: "
                                    + diagnosticInfo);
                    mVideoEncoderInitStatus =
                            VideoEncoderInitStatus.VIDEO_ENCODER_INIT_STATUS_RESOURCE_RECLAIMED;
                }
            } else {
                mVideoEncoderInitStatus =
                        VideoEncoderInitStatus.VIDEO_ENCODER_INIT_STATUS_INITIALIZED_FAILED;
            }
            mVideoEncoderErrorMessage = e;
            return;
        } catch (IllegalArgumentException | IllegalStateException e) {
            mVideoEncoderInitStatus =
                    VideoEncoderInitStatus.VIDEO_ENCODER_INIT_STATUS_INITIALIZED_FAILED;
            mVideoEncoderErrorMessage = e;
            return;
        }

        if (mCameraSurface != null) {
            releaseCameraSurface(false);
        }
        Surface cameraSurface = mVideoEncoder.createInputSurface();
        mCameraSurface = cameraSurface;

        mSessionConfigBuilder = SessionConfig.Builder.createFrom(config);

        if (mDeferrableSurface != null) {
            mDeferrableSurface.close();
        }
        mDeferrableSurface = new ImmediateSurface(mCameraSurface, resolution, getImageFormat());
        mDeferrableSurface.getTerminationFuture().addListener(
                cameraSurface::release, CameraXExecutors.mainThreadExecutor()
        );

        mSessionConfigBuilder.addNonRepeatingSurface(mDeferrableSurface);

        mSessionConfigBuilder.addErrorListener(new SessionConfig.ErrorListener() {
            @Override
            @RequiresPermission(Manifest.permission.RECORD_AUDIO)
            public void onError(@NonNull SessionConfig sessionConfig,
                    @NonNull SessionConfig.SessionError error) {
                // Ensure the attached camera has not changed before calling setupEncoder.
                // TODO(b/143915543): Ensure this never gets called by a camera that is not attached
                //  to this use case so we don't need to do this check.
                if (isCurrentCamera(cameraId)) {
                    // Only reset the pipeline when the bound camera is the same.
                    setupEncoder(cameraId, resolution);
                    notifyReset();
                }
            }
        });

        updateSessionConfig(mSessionConfigBuilder.build());

        // audio encoder setup
        // reset audio inout flag
        mIsAudioEnabled.set(true);

        setAudioParametersByCamcorderProfile(resolution, cameraId);
        mAudioEncoder.reset();
        mAudioEncoder.configure(
                createAudioMediaFormat(), null, null, MediaCodec.CONFIGURE_FLAG_ENCODE);

        if (mAudioRecorder != null) {
            mAudioRecorder.release();
        }
        mAudioRecorder = autoConfigAudioRecordSource(config);
        // check mAudioRecorder
        if (mAudioRecorder == null) {
            Logger.e(TAG, "AudioRecord object cannot initialized correctly!");
            mIsAudioEnabled.set(false);
        }

        synchronized (mMuxerLock) {
            mVideoTrackIndex = -1;
            mAudioTrackIndex = -1;
        }
        mIsRecording = false;
    }

    /**
     * Write a buffer that has been encoded to file.
     *
     * @param bufferIndex the index of the buffer in the videoEncoder that has available data
     * @return returns true if this buffer is the end of the stream
     */
    private boolean writeVideoEncodedBuffer(int bufferIndex) {
        if (bufferIndex < 0) {
            Logger.e(TAG, "Output buffer should not have negative index: " + bufferIndex);
            return false;
        }
        // Get data from buffer
        ByteBuffer outputBuffer = mVideoEncoder.getOutputBuffer(bufferIndex);

        // Check if buffer is valid, if not then return
        if (outputBuffer == null) {
            Logger.d(TAG, "OutputBuffer was null.");
            return false;
        }

        // Write data to mMuxer if available
        if (mMuxerStarted.get()) {
            if (mVideoBufferInfo.size > 0) {
                outputBuffer.position(mVideoBufferInfo.offset);
                outputBuffer.limit(mVideoBufferInfo.offset + mVideoBufferInfo.size);
                mVideoBufferInfo.presentationTimeUs = (System.nanoTime() / 1000);

                synchronized (mMuxerLock) {
                    if (!mIsFirstVideoKeyFrameWrite.get()) {
                        boolean isKeyFrame =
                                (mVideoBufferInfo.flags & MediaCodec.BUFFER_FLAG_KEY_FRAME) != 0;
                        if (isKeyFrame) {
                            Logger.i(TAG,
                                    "First video key frame written.");
                            mIsFirstVideoKeyFrameWrite.set(true);
                        } else {
                            // Request a sync frame immediately
                            final Bundle syncFrame = new Bundle();
                            syncFrame.putInt(MediaCodec.PARAMETER_KEY_REQUEST_SYNC_FRAME, 0);
                            mVideoEncoder.setParameters(syncFrame);
                        }
                    }
                    mMuxer.writeSampleData(mVideoTrackIndex, outputBuffer, mVideoBufferInfo);
                }
            } else {
                Logger.i(TAG, "mVideoBufferInfo.size <= 0, index " + bufferIndex);
            }
        }

        // Release data
        mVideoEncoder.releaseOutputBuffer(bufferIndex, false);

        // Return true if EOS is set
        return (mVideoBufferInfo.flags & MediaCodec.BUFFER_FLAG_END_OF_STREAM) != 0;
    }

    private boolean writeAudioEncodedBuffer(int bufferIndex) {
        ByteBuffer buffer = getOutputBuffer(mAudioEncoder, bufferIndex);
        buffer.position(mAudioBufferInfo.offset);
        if (mMuxerStarted.get()) {
            try {
                if (mAudioBufferInfo.size > 0 && mAudioBufferInfo.presentationTimeUs > 0) {
                    synchronized (mMuxerLock) {
                        if (!mIsFirstAudioSampleWrite.get()) {
                            Logger.i(TAG, "First audio sample written.");
                            mIsFirstAudioSampleWrite.set(true);
                        }
                        mMuxer.writeSampleData(mAudioTrackIndex, buffer, mAudioBufferInfo);
                    }
                } else {
                    Logger.i(TAG, "mAudioBufferInfo size: " + mAudioBufferInfo.size + " "
                            + "presentationTimeUs: " + mAudioBufferInfo.presentationTimeUs);
                }
            } catch (Exception e) {
                Logger.e(
                        TAG,
                        "audio error:size="
                                + mAudioBufferInfo.size
                                + "/offset="
                                + mAudioBufferInfo.offset
                                + "/timeUs="
                                + mAudioBufferInfo.presentationTimeUs);
                e.printStackTrace();
            }
        }
        mAudioEncoder.releaseOutputBuffer(bufferIndex, false);
        return (mAudioBufferInfo.flags & MediaCodec.BUFFER_FLAG_END_OF_STREAM) != 0;
    }

    /**
     * Encoding which runs indefinitely until end of stream is signaled. This should not run on the
     * main thread otherwise it will cause the application to block.
     *
     * @return returns {@code true} if an error condition occurred, otherwise returns {@code false}
     */
    boolean videoEncode(@NonNull OnVideoSavedCallback videoSavedCallback, @NonNull String cameraId,
            @NonNull Size resolution,
            @NonNull OutputFileOptions outputFileOptions) {
        // Main encoding loop. Exits on end of stream.
        boolean errorOccurred = false;
        boolean videoEos = false;
        while (!videoEos && !errorOccurred) {
            // Check for end of stream from main thread
            if (mEndOfVideoStreamSignal.get()) {
                mVideoEncoder.signalEndOfInputStream();
                mEndOfVideoStreamSignal.set(false);
            }

            // Deque buffer to check for processing step
            int outputBufferId =
                    mVideoEncoder.dequeueOutputBuffer(mVideoBufferInfo, DEQUE_TIMEOUT_USEC);
            switch (outputBufferId) {
                case MediaCodec.INFO_OUTPUT_FORMAT_CHANGED:
                    if (mMuxerStarted.get()) {
                        videoSavedCallback.onError(
                                ERROR_ENCODER,
                                "Unexpected change in video encoding format.",
                                null);
                        errorOccurred = true;
                    }

                    synchronized (mMuxerLock) {
                        mVideoTrackIndex = mMuxer.addTrack(mVideoEncoder.getOutputFormat());

                        if ((mIsAudioEnabled.get() && mAudioTrackIndex >= 0
                                && mVideoTrackIndex >= 0)
                                || (!mIsAudioEnabled.get() && mVideoTrackIndex >= 0)) {
                            Logger.i(TAG, "MediaMuxer started on video encode thread and audio "
                                    + "enabled: " + mIsAudioEnabled);
                            mMuxer.start();
                            mMuxerStarted.set(true);
                        }
                    }
                    break;
                case MediaCodec.INFO_TRY_AGAIN_LATER:
                    // Timed out. Just wait until next attempt to deque.
                    break;
                default:
                    videoEos = writeVideoEncodedBuffer(outputBufferId);
            }
        }

        try {
            Logger.i(TAG, "videoEncoder stop");
            mVideoEncoder.stop();
        } catch (IllegalStateException e) {
            videoSavedCallback.onError(ERROR_ENCODER,
                    "Video encoder stop failed!", e);
            errorOccurred = true;
        }

        try {
            // new MediaMuxer instance required for each new file written, and release current one.
            synchronized (mMuxerLock) {
                if (mMuxer != null) {
                    if (mMuxerStarted.get()) {
                        Logger.i(TAG, "Muxer already started");
                        mMuxer.stop();
                    }
                    mMuxer.release();
                    mMuxer = null;
                }
            }

            // A final checking for recording result, if the recorded file has no key
            // frame, then the video file is not playable, needs to call
            // onError() and will be removed.

            boolean checkResult = removeRecordingResultIfNoVideoKeyFrameArrived(outputFileOptions);

            if (!checkResult) {
                videoSavedCallback.onError(ERROR_RECORDING_TOO_SHORT,
                        "The file has no video key frame.", null);
                errorOccurred = true;
            }
        } catch (IllegalStateException e) {
            // The video encoder has not got the key frame yet.
            Logger.i(TAG, "muxer stop IllegalStateException: " + System.currentTimeMillis());
            Logger.i(TAG,
                    "muxer stop exception, mIsFirstVideoKeyFrameWrite: "
                            + mIsFirstVideoKeyFrameWrite.get());
            if (mIsFirstVideoKeyFrameWrite.get()) {
                // If muxer throws IllegalStateException at this moment and also the key frame
                // has received, this will reported as a Muxer stop failed.
                // Otherwise, this error will be ERROR_RECORDING_TOO_SHORT.
                videoSavedCallback.onError(ERROR_MUXER, "Muxer stop failed!", e);
            } else {
                videoSavedCallback.onError(ERROR_RECORDING_TOO_SHORT,
                        "The file has no video key frame.", null);
            }
            errorOccurred = true;
        }

        if (mParcelFileDescriptor != null) {
            try {
                mParcelFileDescriptor.close();
                mParcelFileDescriptor = null;
            } catch (IOException e) {
                videoSavedCallback.onError(ERROR_MUXER, "File descriptor close failed!", e);
                errorOccurred = true;
            }
        }

        mMuxerStarted.set(false);

        // notify the UI thread that the video recording has finished
        mEndOfAudioVideoSignal.set(true);
        mIsFirstVideoKeyFrameWrite.set(false);

        Logger.i(TAG, "Video encode thread end.");
        return errorOccurred;
    }

    boolean audioEncode(OnVideoSavedCallback videoSavedCallback) {
        // Audio encoding loop. Exits on end of stream.
        boolean audioEos = false;
        int outIndex;
        long lastAudioTimestamp = 0;
        while (!audioEos && mIsRecording) {
            // Check for end of stream from main thread
            if (mEndOfAudioStreamSignal.get()) {
                mEndOfAudioStreamSignal.set(false);
                mIsRecording = false;
            }

            // get audio deque input buffer
            if (mAudioEncoder != null && mAudioRecorder != null) {
                try {
                    int index = mAudioEncoder.dequeueInputBuffer(-1);
                    if (index >= 0) {
                        final ByteBuffer buffer = getInputBuffer(mAudioEncoder, index);
                        buffer.clear();
                        int length = mAudioRecorder.read(buffer, mAudioBufferSize);
                        if (length > 0) {
                            mAudioEncoder.queueInputBuffer(
                                    index,
                                    0,
                                    length,
                                    (System.nanoTime() / 1000),
                                    mIsRecording ? 0 : MediaCodec.BUFFER_FLAG_END_OF_STREAM);
                        }
                    }
                } catch (MediaCodec.CodecException e) {
                    Logger.i(TAG, "audio dequeueInputBuffer CodecException " + e.getMessage());
                } catch (IllegalStateException e) {
                    Logger.i(TAG,
                            "audio dequeueInputBuffer IllegalStateException " + e.getMessage());
                }

                // start to dequeue audio output buffer
                do {
                    outIndex = mAudioEncoder.dequeueOutputBuffer(mAudioBufferInfo, 0);
                    switch (outIndex) {
                        case MediaCodec.INFO_OUTPUT_FORMAT_CHANGED:
                            synchronized (mMuxerLock) {
                                mAudioTrackIndex = mMuxer.addTrack(mAudioEncoder.getOutputFormat());
                                if (mAudioTrackIndex >= 0 && mVideoTrackIndex >= 0) {
                                    Logger.i(TAG, "MediaMuxer start on audio encoder thread.");
                                    mMuxer.start();
                                    mMuxerStarted.set(true);
                                }
                            }
                            break;
                        case MediaCodec.INFO_TRY_AGAIN_LATER:
                            break;
                        default:
                            // Drops out of order audio frame if the frame's earlier than last
                            // frame.
                            if (mAudioBufferInfo.presentationTimeUs > lastAudioTimestamp) {
                                audioEos = writeAudioEncodedBuffer(outIndex);
                                lastAudioTimestamp = mAudioBufferInfo.presentationTimeUs;
                            } else {
                                Logger.w(TAG,
                                        "Drops frame, current frame's timestamp "
                                                + mAudioBufferInfo.presentationTimeUs
                                                + " is earlier that last frame "
                                                + lastAudioTimestamp);
                                // Releases this frame from output buffer
                                mAudioEncoder.releaseOutputBuffer(outIndex, false);
                            }
                    }
                } while (outIndex >= 0 && !audioEos); // end of dequeue output buffer
            }
        } // end of while loop

        // Audio Stop
        try {
            Logger.i(TAG, "audioRecorder stop");
            mAudioRecorder.stop();
        } catch (IllegalStateException e) {
            videoSavedCallback.onError(
                    ERROR_ENCODER, "Audio recorder stop failed!", e);
        }

        try {
            mAudioEncoder.stop();
        } catch (IllegalStateException e) {
            videoSavedCallback.onError(ERROR_ENCODER,
                    "Audio encoder stop failed!", e);
        }

        Logger.i(TAG, "Audio encode thread end");
        // Use AtomicBoolean to signal because MediaCodec.signalEndOfInputStream() is not thread
        // safe
        mEndOfVideoStreamSignal.set(true);

        return false;
    }

    private ByteBuffer getInputBuffer(MediaCodec codec, int index) {
        return codec.getInputBuffer(index);
    }

    private ByteBuffer getOutputBuffer(MediaCodec codec, int index) {
        return codec.getOutputBuffer(index);
    }

    /** Creates a {@link MediaFormat} using parameters for audio from the configuration */
    private MediaFormat createAudioMediaFormat() {
        MediaFormat format =
                MediaFormat.createAudioFormat(AUDIO_MIME_TYPE, mAudioSampleRate,
                        mAudioChannelCount);
        format.setInteger(
                MediaFormat.KEY_AAC_PROFILE, MediaCodecInfo.CodecProfileLevel.AACObjectLC);
        format.setInteger(MediaFormat.KEY_BIT_RATE, mAudioBitRate);

        return format;
    }

    /** Create a AudioRecord object to get raw data */
    @RequiresPermission(Manifest.permission.RECORD_AUDIO)
    private AudioRecord autoConfigAudioRecordSource(VideoCaptureConfig config) {
        // Use channel count to determine stereo vs mono
        int channelConfig =
                mAudioChannelCount == 1
                        ? AudioFormat.CHANNEL_IN_MONO
                        : AudioFormat.CHANNEL_IN_STEREO;

        try {
            // Use only ENCODING_PCM_16BIT because it mandatory supported.
            int bufferSize =
                    AudioRecord.getMinBufferSize(mAudioSampleRate, channelConfig,
                            AudioFormat.ENCODING_PCM_16BIT);

            if (bufferSize <= 0) {
                bufferSize = config.getAudioMinBufferSize();
            }

            AudioRecord recorder =
                    new AudioRecord(
                            AudioSource.CAMCORDER,
                            mAudioSampleRate,
                            channelConfig,
                            AudioFormat.ENCODING_PCM_16BIT,
                            bufferSize * 2);

            if (recorder.getState() == AudioRecord.STATE_INITIALIZED) {
                mAudioBufferSize = bufferSize;
                Logger.i(
                        TAG,
                        "source: "
                                + AudioSource.CAMCORDER
                                + " audioSampleRate: "
                                + mAudioSampleRate
                                + " channelConfig: "
                                + channelConfig
                                + " audioFormat: "
                                + AudioFormat.ENCODING_PCM_16BIT
                                + " bufferSize: "
                                + bufferSize);
                return recorder;
            }
        } catch (Exception e) {
            Logger.e(TAG, "Exception, keep trying.", e);
        }
        return null;
    }

    /** Set audio record parameters by CamcorderProfile */
    @SuppressWarnings("deprecation")
    private void setAudioParametersByCamcorderProfile(Size currentResolution, String cameraId) {
        CamcorderProfile profile;
        boolean isCamcorderProfileFound = false;

        try {
            for (int quality : CamcorderQuality) {
                if (CamcorderProfile.hasProfile(Integer.parseInt(cameraId), quality)) {
                    profile = CamcorderProfile.get(Integer.parseInt(cameraId), quality);
                    if (currentResolution.getWidth() == profile.videoFrameWidth
                            && currentResolution.getHeight() == profile.videoFrameHeight) {
                        mAudioChannelCount = profile.audioChannels;
                        mAudioSampleRate = profile.audioSampleRate;
                        mAudioBitRate = profile.audioBitRate;
                        isCamcorderProfileFound = true;
                        break;
                    }
                }
            }
        } catch (NumberFormatException e) {
            Logger.i(TAG, "The camera Id is not an integer because the camera may be a removable "
                    + "device. Use the default values for the audio related settings.");
        }

        // In case no corresponding camcorder profile can be founded, * get default value from
        // VideoCaptureConfig.
        if (!isCamcorderProfileFound) {
            VideoCaptureConfig config = (VideoCaptureConfig) getCurrentConfig();
            mAudioChannelCount = config.getAudioChannelCount();
            mAudioSampleRate = config.getAudioSampleRate();
            mAudioBitRate = config.getAudioBitRate();
        }
    }

    private boolean removeRecordingResultIfNoVideoKeyFrameArrived(
            @NonNull OutputFileOptions outputFileOptions) {
        boolean checkKeyFrame;

        // 1. There should be one video key frame at least.
        Logger.i(TAG,
                "check Recording Result First Video Key Frame Write: "
                        + mIsFirstVideoKeyFrameWrite.get());
        if (!mIsFirstVideoKeyFrameWrite.get()) {
            Logger.i(TAG, "The recording result has no key frame.");
            checkKeyFrame = false;
        } else {
            checkKeyFrame = true;
        }

        // 2. If no key frame, remove file except the target is a file descriptor case.
        if (outputFileOptions.isSavingToFile()) {
            File outputFile = outputFileOptions.getFile();
            if (!checkKeyFrame) {
                Logger.i(TAG, "Delete file.");
                outputFile.delete();
            }
        } else if (outputFileOptions.isSavingToMediaStore()) {
            if (!checkKeyFrame) {
                Logger.i(TAG, "Delete file.");
                if (mSavedVideoUri != null) {
                    ContentResolver contentResolver = outputFileOptions.getContentResolver();
                    contentResolver.delete(mSavedVideoUri, null, null);
                }
            }
        }

        return checkKeyFrame;
    }

    @NonNull
    private MediaMuxer initMediaMuxer(@NonNull OutputFileOptions outputFileOptions)
            throws IOException {
        MediaMuxer mediaMuxer;

        if (outputFileOptions.isSavingToFile()) {
            File savedVideoFile = outputFileOptions.getFile();
            mSavedVideoUri = Uri.fromFile(outputFileOptions.getFile());

            mediaMuxer = new MediaMuxer(savedVideoFile.getAbsolutePath(),
                    MediaMuxer.OutputFormat.MUXER_OUTPUT_MPEG_4);
        } else if (outputFileOptions.isSavingToFileDescriptor()) {
            if (Build.VERSION.SDK_INT < Build.VERSION_CODES.O) {
                throw new IllegalArgumentException("Using a FileDescriptor to record a video is "
                        + "only supported for Android 8.0 or above.");
            }

            mediaMuxer = Api26Impl.createMediaMuxer(outputFileOptions.getFileDescriptor(),
                    MediaMuxer.OutputFormat.MUXER_OUTPUT_MPEG_4);
        } else if (outputFileOptions.isSavingToMediaStore()) {
            ContentValues values = outputFileOptions.getContentValues() != null
                    ? new ContentValues(outputFileOptions.getContentValues())
                    : new ContentValues();

            mSavedVideoUri = outputFileOptions.getContentResolver().insert(
                    outputFileOptions.getSaveCollection(), values);

            if (mSavedVideoUri == null) {
                throw new IOException("Invalid Uri!");
            }

            // Sine API 26, media muxer could be initiated by a FileDescriptor.
            try {
                if (Build.VERSION.SDK_INT < Build.VERSION_CODES.O) {
                    String savedLocationPath = VideoUtil.getAbsolutePathFromUri(
                            outputFileOptions.getContentResolver(), mSavedVideoUri);

                    Logger.i(TAG, "Saved Location Path: " + savedLocationPath);
                    mediaMuxer = new MediaMuxer(savedLocationPath,
                            MediaMuxer.OutputFormat.MUXER_OUTPUT_MPEG_4);
                } else {
                    mParcelFileDescriptor =
                            outputFileOptions.getContentResolver().openFileDescriptor(
                                    mSavedVideoUri, "rw");
                    mediaMuxer = Api26Impl.createMediaMuxer(
                            mParcelFileDescriptor.getFileDescriptor(),
                            MediaMuxer.OutputFormat.MUXER_OUTPUT_MPEG_4);
                }
            } catch (IOException e) {
                mSavedVideoUri = null;
                throw e;
            }
        } else {
            throw new IllegalArgumentException(
                    "The OutputFileOptions should assign before recording");
        }

        return mediaMuxer;
    }

    /**
     * Describes the error that occurred during video capture operations.
     *
     * <p>This is a parameter sent to the error callback functions set in listeners such as {@link
     * VideoCapture.OnVideoSavedCallback#onError(int, String, Throwable)}.
     *
     * <p>See message parameter in onError callback or log for more details.
     *
     * @hide
     */
    @IntDef({ERROR_UNKNOWN, ERROR_ENCODER, ERROR_MUXER, ERROR_RECORDING_IN_PROGRESS,
            ERROR_FILE_IO, ERROR_INVALID_CAMERA, ERROR_RECORDING_TOO_SHORT})
    @Retention(RetentionPolicy.SOURCE)
    @RestrictTo(Scope.LIBRARY_GROUP)
    public @interface VideoCaptureError {
    }

    enum VideoEncoderInitStatus {
        VIDEO_ENCODER_INIT_STATUS_UNINITIALIZED,
        VIDEO_ENCODER_INIT_STATUS_INITIALIZED_FAILED,
        VIDEO_ENCODER_INIT_STATUS_INSUFFICIENT_RESOURCE,
        VIDEO_ENCODER_INIT_STATUS_RESOURCE_RECLAIMED,
    }

    /** Listener containing callbacks for video file I/O events. */
    public interface OnVideoSavedCallback {
        /** Called when the video has been successfully saved. */
        void onVideoSaved(@NonNull OutputFileResults outputFileResults);

        /** Called when an error occurs while attempting to save the video. */
        void onError(@VideoCaptureError int videoCaptureError, @NonNull String message,
                @Nullable Throwable cause);
    }

    /**
     * Provides a base static default configuration for the VideoCapture
     *
     * <p>These values may be overridden by the implementation. They only provide a minimum set of
     * defaults that are implementation independent.
     *
     * @hide
     */
    @RestrictTo(Scope.LIBRARY_GROUP)
    public static final class Defaults
            implements ConfigProvider<VideoCaptureConfig> {
        private static final int DEFAULT_VIDEO_FRAME_RATE = 30;
        /** 8Mb/s the recommend rate for 30fps 1080p */
        private static final int DEFAULT_BIT_RATE = 8 * 1024 * 1024;
        /** Seconds between each key frame */
        private static final int DEFAULT_INTRA_FRAME_INTERVAL = 1;
        /** audio bit rate */
        private static final int DEFAULT_AUDIO_BIT_RATE = 64000;
        /** audio sample rate */
        private static final int DEFAULT_AUDIO_SAMPLE_RATE = 8000;
        /** audio channel count */
        private static final int DEFAULT_AUDIO_CHANNEL_COUNT = 1;
        /** audio default minimum buffer size */
        private static final int DEFAULT_AUDIO_MIN_BUFFER_SIZE = 1024;
        /** Current max resolution of VideoCapture is set as FHD */
        private static final Size DEFAULT_MAX_RESOLUTION = new Size(1920, 1080);
        /** Surface occupancy priority to this use case */
        private static final int DEFAULT_SURFACE_OCCUPANCY_PRIORITY = 3;
        private static final int DEFAULT_ASPECT_RATIO = AspectRatio.RATIO_16_9;

        private static final VideoCaptureConfig DEFAULT_CONFIG;

        static {
            Builder builder = new Builder()
                    .setVideoFrameRate(DEFAULT_VIDEO_FRAME_RATE)
                    .setBitRate(DEFAULT_BIT_RATE)
                    .setIFrameInterval(DEFAULT_INTRA_FRAME_INTERVAL)
                    .setAudioBitRate(DEFAULT_AUDIO_BIT_RATE)
                    .setAudioSampleRate(DEFAULT_AUDIO_SAMPLE_RATE)
                    .setAudioChannelCount(DEFAULT_AUDIO_CHANNEL_COUNT)
                    .setAudioMinBufferSize(DEFAULT_AUDIO_MIN_BUFFER_SIZE)
                    .setMaxResolution(DEFAULT_MAX_RESOLUTION)
                    .setSurfaceOccupancyPriority(DEFAULT_SURFACE_OCCUPANCY_PRIORITY)
                    .setTargetAspectRatio(DEFAULT_ASPECT_RATIO);

            DEFAULT_CONFIG = builder.getUseCaseConfig();
        }

        @NonNull
        @Override
        public VideoCaptureConfig getConfig() {
            return DEFAULT_CONFIG;
        }
    }

    /** Holder class for metadata that should be saved alongside captured video. */
    public static final class Metadata {
        /** Data representing a geographic location. */
        @Nullable
        public Location location;
    }

    private static final class VideoSavedListenerWrapper implements OnVideoSavedCallback {

        @NonNull
        Executor mExecutor;
        @NonNull
        OnVideoSavedCallback mOnVideoSavedCallback;

        VideoSavedListenerWrapper(@NonNull Executor executor,
                @NonNull OnVideoSavedCallback onVideoSavedCallback) {
            mExecutor = executor;
            mOnVideoSavedCallback = onVideoSavedCallback;
        }

        @Override
        public void onVideoSaved(@NonNull OutputFileResults outputFileResults) {
            try {
                mExecutor.execute(() -> mOnVideoSavedCallback.onVideoSaved(outputFileResults));
            } catch (RejectedExecutionException e) {
                Logger.e(TAG, "Unable to post to the supplied executor.");
            }
        }

        @Override
        public void onError(@VideoCaptureError int videoCaptureError, @NonNull String message,
                @Nullable Throwable cause) {
            try {
                mExecutor.execute(
                        () -> mOnVideoSavedCallback.onError(videoCaptureError, message, cause));
            } catch (RejectedExecutionException e) {
                Logger.e(TAG, "Unable to post to the supplied executor.");
            }
        }

    }

    /** Builder for a {@link VideoCapture}. */
    @SuppressWarnings("ObjectToString")
    public static final class Builder
            implements
            UseCaseConfig.Builder<VideoCapture, VideoCaptureConfig, Builder>,
            ImageOutputConfig.Builder<Builder>,
            ThreadConfig.Builder<Builder> {

        private final MutableOptionsBundle mMutableConfig;

        /** Creates a new Builder object. */
        public Builder() {
            this(MutableOptionsBundle.create());
        }

        private Builder(@NonNull MutableOptionsBundle mutableConfig) {
            mMutableConfig = mutableConfig;

            Class<?> oldConfigClass =
                    mutableConfig.retrieveOption(OPTION_TARGET_CLASS, null);
            if (oldConfigClass != null && !oldConfigClass.equals(VideoCapture.class)) {
                throw new IllegalArgumentException(
                        "Invalid target class configuration for "
                                + Builder.this
                                + ": "
                                + oldConfigClass);
            }

            setTargetClass(VideoCapture.class);
        }

        /**
         * Generates a Builder from another Config object.
         *
         * @param configuration An immutable configuration to pre-populate this builder.
         * @return The new Builder.
         * @hide
         */
        @RestrictTo(Scope.LIBRARY_GROUP)
        @NonNull
        static Builder fromConfig(@NonNull Config configuration) {
            return new Builder(MutableOptionsBundle.from(configuration));
        }


        /**
         * Generates a Builder from another Config object
         *
         * @param configuration An immutable configuration to pre-populate this builder.
         * @return The new Builder.
         */
        @NonNull
        public static Builder fromConfig(@NonNull VideoCaptureConfig configuration) {
            return new Builder(MutableOptionsBundle.from(configuration));
        }

        /**
         * {@inheritDoc}
         *
         * @hide
         */
        @RestrictTo(Scope.LIBRARY_GROUP)
        @Override
        @NonNull
        public MutableConfig getMutableConfig() {
            return mMutableConfig;
        }

        /**
         * {@inheritDoc}
         *
         * @hide
         */
        @RestrictTo(Scope.LIBRARY_GROUP)
        @NonNull
        @Override
        public VideoCaptureConfig getUseCaseConfig() {
            return new VideoCaptureConfig(OptionsBundle.from(mMutableConfig));
        }

        /**
         * Builds an immutable {@link VideoCaptureConfig} from the current state.
         *
         * @return A {@link VideoCaptureConfig} populated with the current state.
         */
        @Override
        @NonNull
        public VideoCapture build() {
            // Error at runtime for using both setTargetResolution and setTargetAspectRatio on
            // the same config.
            if (getMutableConfig().retrieveOption(OPTION_TARGET_ASPECT_RATIO, null) != null
                    && getMutableConfig().retrieveOption(OPTION_TARGET_RESOLUTION, null) != null) {
                throw new IllegalArgumentException(
                        "Cannot use both setTargetResolution and setTargetAspectRatio on the same "
                                + "config.");
            }
            return new VideoCapture(getUseCaseConfig());
        }

        /**
         * Sets the recording frames per second.
         *
         * @param videoFrameRate The requested interval in seconds.
         * @return The current Builder.
         * @hide
         */
        @RestrictTo(Scope.LIBRARY_GROUP)
        @NonNull
        public Builder setVideoFrameRate(int videoFrameRate) {
            getMutableConfig().insertOption(OPTION_VIDEO_FRAME_RATE, videoFrameRate);
            return this;
        }

        /**
         * Sets the encoding bit rate.
         *
         * @param bitRate The requested bit rate in bits per second.
         * @return The current Builder.
         * @hide
         */
        @RestrictTo(Scope.LIBRARY_GROUP)
        @NonNull
        public Builder setBitRate(int bitRate) {
            getMutableConfig().insertOption(OPTION_BIT_RATE, bitRate);
            return this;
        }

        /**
         * Sets number of seconds between each key frame in seconds.
         *
         * @param interval The requested interval in seconds.
         * @return The current Builder.
         * @hide
         */
        @RestrictTo(Scope.LIBRARY_GROUP)
        @NonNull
        public Builder setIFrameInterval(int interval) {
            getMutableConfig().insertOption(OPTION_INTRA_FRAME_INTERVAL, interval);
            return this;
        }

        /**
         * Sets the bit rate of the audio stream.
         *
         * @param bitRate The requested bit rate in bits/s.
         * @return The current Builder.
         * @hide
         */
        @RestrictTo(Scope.LIBRARY_GROUP)
        @NonNull
        public Builder setAudioBitRate(int bitRate) {
            getMutableConfig().insertOption(OPTION_AUDIO_BIT_RATE, bitRate);
            return this;
        }

        /**
         * Sets the sample rate of the audio stream.
         *
         * @param sampleRate The requested sample rate in bits/s.
         * @return The current Builder.
         * @hide
         */
        @RestrictTo(Scope.LIBRARY_GROUP)
        @NonNull
        public Builder setAudioSampleRate(int sampleRate) {
            getMutableConfig().insertOption(OPTION_AUDIO_SAMPLE_RATE, sampleRate);
            return this;
        }

        /**
         * Sets the number of audio channels.
         *
         * @param channelCount The requested number of audio channels.
         * @return The current Builder.
         * @hide
         */
        @RestrictTo(Scope.LIBRARY_GROUP)
        @NonNull
        public Builder setAudioChannelCount(int channelCount) {
            getMutableConfig().insertOption(OPTION_AUDIO_CHANNEL_COUNT, channelCount);
            return this;
        }

        /**
         * Sets the audio min buffer size.
         *
         * @param minBufferSize The requested audio minimum buffer size, in bytes.
         * @return The current Builder.
         * @hide
         */
        @RestrictTo(Scope.LIBRARY_GROUP)
        @NonNull
        public Builder setAudioMinBufferSize(int minBufferSize) {
            getMutableConfig().insertOption(OPTION_AUDIO_MIN_BUFFER_SIZE, minBufferSize);
            return this;
        }

        // Implementations of TargetConfig.Builder default methods

        /** @hide */
        @RestrictTo(Scope.LIBRARY_GROUP)
        @Override
        @NonNull
        public Builder setTargetClass(@NonNull Class<VideoCapture> targetClass) {
            getMutableConfig().insertOption(OPTION_TARGET_CLASS, targetClass);

            // If no name is set yet, then generate a unique name
            if (null == getMutableConfig().retrieveOption(OPTION_TARGET_NAME, null)) {
                String targetName = targetClass.getCanonicalName() + "-" + UUID.randomUUID();
                setTargetName(targetName);
            }

            return this;
        }

        /**
         * Sets the name of the target object being configured, used only for debug logging.
         *
         * <p>The name should be a value that can uniquely identify an instance of the object being
         * configured.
         *
         * <p>If not set, the target name will default to an unique name automatically generated
         * with the class canonical name and random UUID.
         *
         * @param targetName A unique string identifier for the instance of the class being
         *                   configured.
         * @return the current Builder.
         */
        @Override
        @NonNull
        public Builder setTargetName(@NonNull String targetName) {
            getMutableConfig().insertOption(OPTION_TARGET_NAME, targetName);
            return this;
        }

        // Implementations of ImageOutputConfig.Builder default methods

        /**
         * Sets the aspect ratio of the intended target for images from this configuration.
         *
         * <p>It is not allowed to set both target aspect ratio and target resolution on the same
         * use case.
         *
         * <p>The target aspect ratio is used as a hint when determining the resulting output aspect
         * ratio which may differ from the request, possibly due to device constraints.
         * Application code should check the resulting output's resolution.
         *
         * <p>If not set, resolutions with aspect ratio 4:3 will be considered in higher
         * priority.
         *
         * @param aspectRatio A {@link AspectRatio} representing the ratio of the
         *                    target's width and height.
         * @return The current Builder.
         * @hide
         */
        @RestrictTo(Scope.LIBRARY_GROUP)
        @NonNull
        @Override
        public Builder setTargetAspectRatio(@AspectRatio.Ratio int aspectRatio) {
            getMutableConfig().insertOption(OPTION_TARGET_ASPECT_RATIO, aspectRatio);
            return this;
        }

        /**
         * Sets the rotation of the intended target for images from this configuration.
         *
         * <p>This is one of four valid values: {@link Surface#ROTATION_0}, {@link
         * Surface#ROTATION_90}, {@link Surface#ROTATION_180}, {@link Surface#ROTATION_270}.
         * Rotation values are relative to the "natural" rotation, {@link Surface#ROTATION_0}.
         *
         * <p>If not set, the target rotation will default to the value of
         * {@link Display#getRotation()} of the default display at the time the use case is
         * created. The use case is fully created once it has been attached to a camera.
         *
         * @param rotation The rotation of the intended target.
         * @return The current Builder.
         * @hide
         */
        @RestrictTo(Scope.LIBRARY_GROUP)
        @NonNull
        @Override
        public Builder setTargetRotation(@RotationValue int rotation) {
            getMutableConfig().insertOption(OPTION_TARGET_ROTATION, rotation);
            return this;
        }

        /**
         * Sets the resolution of the intended target from this configuration.
         *
         * <p>The target resolution attempts to establish a minimum bound for the image resolution.
         * The actual image resolution will be the closest available resolution in size that is not
         * smaller than the target resolution, as determined by the Camera implementation. However,
         * if no resolution exists that is equal to or larger than the target resolution, the
         * nearest available resolution smaller than the target resolution will be chosen.
         *
         * <p>It is not allowed to set both target aspect ratio and target resolution on the same
         * use case.
         *
         * <p>The target aspect ratio will also be set the same as the aspect ratio of the provided
         * {@link Size}. Make sure to set the target resolution with the correct orientation.
         *
         * @param resolution The target resolution to choose from supported output sizes list.
         * @return The current Builder.
         * @hide
         */
        @RestrictTo(Scope.LIBRARY_GROUP)
        @NonNull
        @Override
        public Builder setTargetResolution(@NonNull Size resolution) {
            getMutableConfig().insertOption(OPTION_TARGET_RESOLUTION, resolution);
            return this;
        }

        /**
         * Sets the default resolution of the intended target from this configuration.
         *
         * @param resolution The default resolution to choose from supported output sizes list.
         * @return The current Builder.
         * @hide
         */
        @RestrictTo(Scope.LIBRARY_GROUP)
        @NonNull
        @Override
        public Builder setDefaultResolution(@NonNull Size resolution) {
            getMutableConfig().insertOption(OPTION_DEFAULT_RESOLUTION, resolution);
            return this;
        }

        /** @hide */
        @RestrictTo(Scope.LIBRARY_GROUP)
        @NonNull
        @Override
        public Builder setMaxResolution(@NonNull Size resolution) {
            getMutableConfig().insertOption(OPTION_MAX_RESOLUTION, resolution);
            return this;
        }

        /** @hide */
        @RestrictTo(Scope.LIBRARY_GROUP)
        @Override
        @NonNull
        public Builder setSupportedResolutions(@NonNull List<Pair<Integer, Size[]>> resolutions) {
            getMutableConfig().insertOption(OPTION_SUPPORTED_RESOLUTIONS, resolutions);
            return this;
        }

        // Implementations of ThreadConfig.Builder default methods

        /**
         * Sets the default executor that will be used for background tasks.
         *
         * <p>If not set, the background executor will default to an automatically generated
         * {@link Executor}.
         *
         * @param executor The executor which will be used for background tasks.
         * @return the current Builder.
         * @hide
         */
        @RestrictTo(Scope.LIBRARY_GROUP)
        @Override
        @NonNull
        public Builder setBackgroundExecutor(@NonNull Executor executor) {
            getMutableConfig().insertOption(OPTION_BACKGROUND_EXECUTOR, executor);
            return this;
        }

        // Implementations of UseCaseConfig.Builder default methods

        /** @hide */
        @RestrictTo(Scope.LIBRARY_GROUP)
        @Override
        @NonNull
        public Builder setDefaultSessionConfig(@NonNull SessionConfig sessionConfig) {
            getMutableConfig().insertOption(OPTION_DEFAULT_SESSION_CONFIG, sessionConfig);
            return this;
        }

        /** @hide */
        @RestrictTo(Scope.LIBRARY_GROUP)
        @Override
        @NonNull
        public Builder setDefaultCaptureConfig(@NonNull CaptureConfig captureConfig) {
            getMutableConfig().insertOption(OPTION_DEFAULT_CAPTURE_CONFIG, captureConfig);
            return this;
        }

        /** @hide */
        @RestrictTo(Scope.LIBRARY_GROUP)
        @Override
        @NonNull
        public Builder setSessionOptionUnpacker(
                @NonNull SessionConfig.OptionUnpacker optionUnpacker) {
            getMutableConfig().insertOption(OPTION_SESSION_CONFIG_UNPACKER, optionUnpacker);
            return this;
        }

        /** @hide */
        @RestrictTo(Scope.LIBRARY_GROUP)
        @Override
        @NonNull
        public Builder setCaptureOptionUnpacker(
                @NonNull CaptureConfig.OptionUnpacker optionUnpacker) {
            getMutableConfig().insertOption(OPTION_CAPTURE_CONFIG_UNPACKER, optionUnpacker);
            return this;
        }

        /** @hide */
        @RestrictTo(Scope.LIBRARY_GROUP)
        @Override
        @NonNull
        public Builder setSurfaceOccupancyPriority(int priority) {
            getMutableConfig().insertOption(OPTION_SURFACE_OCCUPANCY_PRIORITY, priority);
            return this;
        }

        /** @hide */
        @RestrictTo(Scope.LIBRARY)
        @Override
        @NonNull
        public Builder setCameraSelector(@NonNull CameraSelector cameraSelector) {
            getMutableConfig().insertOption(OPTION_CAMERA_SELECTOR, cameraSelector);
            return this;
        }

        /** @hide */
        @RestrictTo(Scope.LIBRARY_GROUP)
        @Override
        @NonNull
        public Builder setUseCaseEventCallback(
                @NonNull UseCase.EventCallback useCaseEventCallback) {
            getMutableConfig().insertOption(OPTION_USE_CASE_EVENT_CALLBACK, useCaseEventCallback);
            return this;
        }
    }

    /**
     * Info about the saved video file.
     */
    public static class OutputFileResults {
        @Nullable
        private Uri mSavedUri;

        OutputFileResults(@Nullable Uri savedUri) {
            mSavedUri = savedUri;
        }

        /**
         * Returns the {@link Uri} of the saved video file.
         *
         * <p> This field is only returned if the {@link VideoCapture.OutputFileOptions} is
         * backed by {@link MediaStore} constructed with
         * {@link androidx.camera.core.VideoCapture.OutputFileOptions}.
         */
        @Nullable
        public Uri getSavedUri() {
            return mSavedUri;
        }
    }

    /**
     * Options for saving newly captured video.
     *
     * <p> this class is used to configure save location and metadata. Save location can be
     * either a {@link File}, {@link MediaStore}. The metadata will be
     * stored with the saved video.
     */
    public static final class OutputFileOptions {

        // Empty metadata object used as a placeholder for no user-supplied metadata.
        // Should be initialized to all default values.
        private static final Metadata EMPTY_METADATA = new Metadata();

        @Nullable
        private final File mFile;
        @Nullable
        private final FileDescriptor mFileDescriptor;
        @Nullable
        private final ContentResolver mContentResolver;
        @Nullable
        private final Uri mSaveCollection;
        @Nullable
        private final ContentValues mContentValues;
        @Nullable
        private final Metadata mMetadata;

        OutputFileOptions(@Nullable File file,
                @Nullable FileDescriptor fileDescriptor,
                @Nullable ContentResolver contentResolver,
                @Nullable Uri saveCollection,
                @Nullable ContentValues contentValues,
                @Nullable Metadata metadata) {
            mFile = file;
            mFileDescriptor = fileDescriptor;
            mContentResolver = contentResolver;
            mSaveCollection = saveCollection;
            mContentValues = contentValues;
            mMetadata = metadata == null ? EMPTY_METADATA : metadata;
        }

        /** Returns the File object which is set by the {@link OutputFileOptions.Builder}. */
        @Nullable
        File getFile() {
            return mFile;
        }

        /**
         * Returns the FileDescriptor object which is set by the {@link OutputFileOptions.Builder}.
         */
        @Nullable
        FileDescriptor getFileDescriptor() {
            return mFileDescriptor;
        }

        /** Returns the content resolver which is set by the {@link OutputFileOptions.Builder}. */
        @Nullable
        ContentResolver getContentResolver() {
            return mContentResolver;
        }

        /** Returns the URI which is set by the {@link OutputFileOptions.Builder}. */
        @Nullable
        Uri getSaveCollection() {
            return mSaveCollection;
        }

        /** Returns the content values which is set by the {@link OutputFileOptions.Builder}. */
        @Nullable
        ContentValues getContentValues() {
            return mContentValues;
        }

        /** Return the metadata which is set by the {@link OutputFileOptions.Builder}.. */
        @Nullable
        Metadata getMetadata() {
            return mMetadata;
        }

        /** Checking the caller wants to save video to MediaStore. */
        boolean isSavingToMediaStore() {
            return getSaveCollection() != null && getContentResolver() != null
                    && getContentValues() != null;
        }

        /** Checking the caller wants to save video to a File. */
        boolean isSavingToFile() {
            return getFile() != null;
        }

        /** Checking the caller wants to save video to a FileDescriptor. */
        boolean isSavingToFileDescriptor() {
            return getFileDescriptor() != null;
        }

        /**
         * Builder class for {@link OutputFileOptions}.
         */
        public static final class Builder {
            @Nullable
            private File mFile;
            @Nullable
            private FileDescriptor mFileDescriptor;
            @Nullable
            private ContentResolver mContentResolver;
            @Nullable
            private Uri mSaveCollection;
            @Nullable
            private ContentValues mContentValues;
            @Nullable
            private Metadata mMetadata;

            /**
             * Creates options to write captured video to a {@link File}.
             *
             * @param file save location of the video.
             */
            public Builder(@NonNull File file) {
                mFile = file;
            }

            /**
             * Creates options to write captured video to a {@link FileDescriptor}.
             *
             * <p>Using a FileDescriptor to record a video is only supported for Android 8.0 or
             * above.
             *
             * @param fileDescriptor to save the video.
             * @throws IllegalArgumentException when the device is not running Android 8.0 or above.
             */
            public Builder(@NonNull FileDescriptor fileDescriptor) {
                Preconditions.checkArgument(Build.VERSION.SDK_INT >= Build.VERSION_CODES.O,
                        "Using a FileDescriptor to record a video is only supported for Android 8"
                                + ".0 or above.");

                mFileDescriptor = fileDescriptor;
            }

            /**
             * Creates options to write captured video to {@link MediaStore}.
             *
             * Example:
             *
             * <pre>{@code
             *
             * ContentValues contentValues = new ContentValues();
             * contentValues.put(MediaStore.MediaColumns.DISPLAY_NAME, "NEW_VIDEO");
             * contentValues.put(MediaStore.MediaColumns.MIME_TYPE, "video/mp4");
             *
             * OutputFileOptions options = new OutputFileOptions.Builder(
             *         getContentResolver(),
             *         MediaStore.Video.Media.EXTERNAL_CONTENT_URI,
             *         contentValues).build();
             *
             * }</pre>
             *
             * @param contentResolver to access {@link MediaStore}
             * @param saveCollection  The URL of the table to insert into.
             * @param contentValues   to be included in the created video file.
             */
            public Builder(@NonNull ContentResolver contentResolver,
                    @NonNull Uri saveCollection,
                    @NonNull ContentValues contentValues) {
                mContentResolver = contentResolver;
                mSaveCollection = saveCollection;
                mContentValues = contentValues;
            }

            /**
             * Sets the metadata to be stored with the saved video.
             *
             * @param metadata Metadata to be stored with the saved video.
             */
            @NonNull
            public Builder setMetadata(@NonNull Metadata metadata) {
                mMetadata = metadata;
                return this;
            }

            /**
             * Builds {@link OutputFileOptions}.
             */
            @NonNull
            public OutputFileOptions build() {
                return new OutputFileOptions(mFile, mFileDescriptor, mContentResolver,
                        mSaveCollection, mContentValues, mMetadata);
            }
        }
    }

    /**
     * Nested class to avoid verification errors for methods introduced in Android 8.0 (API 26).
     */
    @RequiresApi(26)
    private static class Api26Impl {

        private Api26Impl() {
        }

        @DoNotInline
        @NonNull
        static MediaMuxer createMediaMuxer(@NonNull FileDescriptor fileDescriptor, int format)
                throws IOException {
            return new MediaMuxer(fileDescriptor, format);
        }
    }

    /**
     * Nested class to avoid verification errors for methods introduced in Android 6.0 (API 23).
     */
    @RequiresApi(23)
    private static class Api23Impl {

        private Api23Impl() {
        }

        @DoNotInline
        static int getCodecExceptionErrorCode(MediaCodec.CodecException e) {
            return e.getErrorCode();
        }
    }
}