content: /*
   * Copyright 2017 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.media;
  
  import android.annotation.CallbackExecutor;
  import android.annotation.IntDef;
  import android.annotation.NonNull;
  import android.annotation.Nullable;
  import android.annotation.StringDef;
  import android.annotation.TestApi;
  import android.content.ContentResolver;
  import android.content.Context;
  import android.content.res.AssetFileDescriptor;
  import android.graphics.Rect;
  import android.graphics.SurfaceTexture;
  import android.media.MediaDrm.KeyRequest;
  import android.media.MediaPlayer2.DrmInfo;
  import android.media.MediaPlayer2Proto.PlayerMessage;
  import android.media.MediaPlayer2Proto.Value;
  import android.media.protobuf.InvalidProtocolBufferException;
  import android.net.Uri;
  import android.os.Handler;
  import android.os.HandlerThread;
  import android.os.Looper;
  import android.os.Message;
  import android.os.ParcelFileDescriptor;
  import android.os.PersistableBundle;
  import android.os.PowerManager;
  import android.util.Log;
  import android.util.Pair;
  import android.util.Size;
  import android.view.Surface;
  import android.view.SurfaceHolder;
  
  import com.android.internal.annotations.GuardedBy;
  
  import java.io.ByteArrayOutputStream;
  import java.io.File;
  import java.io.FileDescriptor;
  import java.io.FileInputStream;
  import java.io.IOException;
  import java.io.InputStream;
  import java.lang.annotation.Retention;
  import java.lang.annotation.RetentionPolicy;
  import java.lang.ref.WeakReference;
  import java.net.HttpCookie;
  import java.net.HttpURLConnection;
  import java.net.URL;
  import java.nio.ByteOrder;
  import java.util.ArrayList;
  import java.util.Arrays;
  import java.util.Collection;
  import java.util.Collections;
  import java.util.HashMap;
  import java.util.Iterator;
  import java.util.LinkedList;
  import java.util.List;
  import java.util.Map;
  import java.util.Queue;
  import java.util.UUID;
  import java.util.concurrent.CompletableFuture;
  import java.util.concurrent.ConcurrentLinkedQueue;
  import java.util.concurrent.ExecutionException;
  import java.util.concurrent.Executor;
  import java.util.concurrent.ExecutorService;
  import java.util.concurrent.Executors;
  import java.util.concurrent.Future;
  import java.util.concurrent.RejectedExecutionException;
  import java.util.concurrent.TimeUnit;
  import java.util.concurrent.TimeoutException;
  import java.util.concurrent.atomic.AtomicInteger;
  import java.util.concurrent.atomic.AtomicLong;
  
  /**
   * MediaPlayer2 class can be used to control playback of audio/video files and streams.
   *
   * <p>
   * This API is not generally intended for third party application developers.
   * Use the <a href="{@docRoot}jetpack/androidx.html">AndroidX</a>
   * <a href="{@docRoot}reference/androidx/media2/package-summary.html">Media2 Library</a>
   * for consistent behavior across all devices.
   *
   * <p>Topics covered here are:
   * <ol>
   * <li><a href="#PlayerStates">Player states</a>
   * <li><a href="#InvalidStates">Invalid method calls</a>
   * <li><a href="#Permissions">Permissions</a>
   * <li><a href="#Callbacks">Callbacks</a>
   * </ol>
   *
   *
   * <h3 id="PlayerStates">Player states</h3>
   *
   * <p>The playback control of audio/video files is managed as a state machine.</p>
   * <p><div style="text-align:center;"><img src="../../../images/mediaplayer2_state_diagram.png"
   *         alt="MediaPlayer2 State diagram"
   *         border="0" /></div></p>
   * <p>The MediaPlayer2 object has five states:</p>
   * <ol>
   *     <li><p>{@link #PLAYER_STATE_IDLE}: MediaPlayer2 is in the <strong>Idle</strong>
   *         state after it's created, or after calling {@link #reset()}.</p>
   *
   *         <p>While in this state, you should call
   *         {@link #setDataSource setDataSource}. It is a good
   *         programming practice to register an {@link EventCallback#onCallCompleted onCallCompleted}
   *         <a href="#Callbacks">callback</a> and watch for {@link #CALL_STATUS_BAD_VALUE} and
   *         {@link #CALL_STATUS_ERROR_IO}, which might be caused by <code>setDataSource</code>.
   *         </p>
   *
   *         <p>Calling {@link #prepare()} transfers a MediaPlayer2 object to
   *         the <strong>Prepared</strong> state. Note
   *         that {@link #prepare()} is asynchronous. When the preparation completes,
   *         if you register an {@link EventCallback#onInfo onInfo} <a href="#Callbacks">callback</a>,
   *         the player executes the callback
   *         with {@link #MEDIA_INFO_PREPARED} and transitions to the
   *         <strong>Prepared</strong> state.</p>
   *         </li>
   *
   *     <li>{@link #PLAYER_STATE_PREPARED}: A MediaPlayer object must be in the
   *         <strong>Prepared</strong> state before playback can be started for the first time.
   *         While in this state, you can set player properties
   *         such as audio/sound volume and looping by invoking the corresponding set methods.
   *         Calling {@link #play()} transfers a MediaPlayer2 object to
   *         the <strong>Playing</strong> state.
   *      </li>
   *
   *     <li>{@link #PLAYER_STATE_PLAYING}:
   *         <p>The player plays the data source while in this state.
   *         If you register an {@link EventCallback#onInfo onInfo} <a href="#Callbacks">callback</a>,
   *         the player regularly executes the callback with
   *         {@link #MEDIA_INFO_BUFFERING_UPDATE}.
   *         This allows applications to keep track of the buffering status
   *         while streaming audio/video.</p>
   *
   *         <p> When the playback reaches the end of stream, the behavior depends on whether or
   *         not you've enabled looping by calling {@link #loopCurrent}:</p>
   *         <ul>
   *         <li>If the looping mode was set to <code>false</code>, the player will transfer
   *         to the <strong>Paused</strong> state. If you registered an {@link EventCallback#onInfo
   *         onInfo} <a href="#Callbacks">callback</a>
   *         the player calls the callback with {@link #MEDIA_INFO_DATA_SOURCE_END} and enters
   *         the <strong>Paused</strong> state.
   *         </li>
   *         <li>If the looping mode was set to <code>true</code>,
   *         the MediaPlayer2 object remains in the <strong>Playing</strong> state and replays its
   *         data source from the beginning.</li>
   *         </ul>
   *         </li>
   *
   *     <li>{@link #PLAYER_STATE_PAUSED}: Audio/video playback pauses while in this state.
   *         Call {@link #play()} to resume playback from the position where it paused.</li>
   *
   *     <li>{@link #PLAYER_STATE_ERROR}: <p>In general, playback might fail due to various
   *          reasons such as unsupported audio/video format, poorly interleaved
   *          audio/video, resolution too high, streaming timeout, and others.
   *          In addition, due to programming errors, a playback
   *          control operation might be performed from an <a href="#InvalidStates">invalid state</a>.
   *          In these cases the player transitions to the <strong>Error</strong> state.</p>
   *
   *          <p>If you register an {@link EventCallback#onError onError}}
   *          <a href="#Callbacks">callback</a>,
   *          the callback will be performed when entering the state. When programming errors happen,
   *          such as calling {@link #prepare()} and
   *          {@link #setDataSource} methods
   *          from an <a href="#InvalidStates">invalid state</a>, the callback is called with
   *          {@link #CALL_STATUS_INVALID_OPERATION}. The MediaPlayer2 object enters the
   *          <strong>Error</strong> state whether or not a callback exists. </p>
   *
   *          <p>To recover from an error and reuse a MediaPlayer2 object that is in the <strong>
   *          Error</strong> state,
   *          call {@link #reset()}. The object will return to the <strong>Idle</strong>
   *          state and all state information will be lost.</p>
   *          </li>
   * </ol>
   *
   * <p>You should follow these best practices when coding an app that uses MediaPlayer2:</p>
   *
   * <ul>
   *
   * <li>Use <a href="#Callbacks">callbacks</a> to respond to state changes and errors.</li>
   *
   * <li>When  a MediaPlayer2 object is no longer being used, call {@link #close()} as soon as
   * possible to release the resources used by the internal player engine associated with the
   * MediaPlayer2. Failure to call {@link #close()} may cause subsequent instances of
   * MediaPlayer2 objects to fallback to software implementations or fail altogether.
   * You cannot use MediaPlayer2
   * after you call {@link #close()}. There is no way to bring it back to any other state.</li>
   *
   * <li>The current playback position can be retrieved with a call to
   * {@link #getCurrentPosition()},
   * which is helpful for applications such as a Music player that need to keep track of the playback
   * progress.</li>
   *
   * <li>The playback position can be adjusted with a call to {@link #seekTo}. Although the
   * asynchronous {@link #seekTo} call returns right away, the actual seek operation may take a
   * while to finish, especially for audio/video being streamed. If you register an
   * {@link EventCallback#onCallCompleted onCallCompleted} <a href="#Callbacks">callback</a>,
   * the callback is
   * called When the seek operation completes with {@link #CALL_COMPLETED_SEEK_TO}.</li>
   *
   * <li>You can call {@link #seekTo} from the <strong>Paused</strong> state.
   * In this case, if you are playing a video stream and
   * the requested position is valid  one video frame is displayed.</li>
   *
   * </ul>
   *
   * <h3 id="InvalidStates">Invalid method calls</h3>
   *
   * <p>The only methods you safely call from the <strong>Error</strong> state are
   * {@link #close},
   * {@link #reset},
   * {@link #notifyWhenCommandLabelReached},
   * {@link #clearPendingCommands},
   * {@link #registerEventCallback},
   * {@link #unregisterEventCallback}
   * and {@link #getState}.
   * Any other methods might throw an exception, return meaningless data, or invoke a
   * {@link EventCallback#onCallCompleted onCallCompleted} with an error code.</p>
   *
   * <p>Most methods can be called from any non-Error state. They will either perform their work or
   * silently have no effect. The following table lists the methods that will invoke a
   * {@link EventCallback#onCallCompleted onCallCompleted} with an error code
   * or throw an exception when they are called from the associated invalid states.</p>
   *
   * <table border="0" cellspacing="0" cellpadding="0">
   * <tr><th>Method Name</th>
   * <th>Invalid States</th></tr>
   *
   * <tr><td>setDataSource</td> <td>{Prepared, Paused, Playing}</td></tr>
   * <tr><td>prepare</td> <td>{Prepared, Paused, Playing}</td></tr>
   * <tr><td>play</td> <td>{Idle}</td></tr>
   * <tr><td>pause</td> <td>{Idle}</td></tr>
   * <tr><td>seekTo</td> <td>{Idle}</td></tr>
   * <tr><td>getCurrentPosition</td> <td>{Idle}</td></tr>
   * <tr><td>getDuration</td> <td>{Idle}</td></tr>
   * <tr><td>getBufferedPosition</td> <td>{Idle}</td></tr>
   * <tr><td>getTrackInfo</td> <td>{Idle}</td></tr>
   * <tr><td>getSelectedTrack</td> <td>{Idle}</td></tr>
   * <tr><td>selectTrack</td> <td>{Idle}</td></tr>
   * <tr><td>deselectTrack</td> <td>{Idle}</td></tr>
   * </table>
   *
   * <h3 id="Permissions">Permissions</h3>
   * <p>This class requires the {@link android.Manifest.permission#INTERNET} permission
   * when used with network-based content.
   *
   * <h3 id="Callbacks">Callbacks</h3>
   * <p>Many errors do not result in a transition to the  <strong>Error</strong> state.
   * It is good programming practice to register callback listeners using
   * {@link #registerEventCallback}.
   * You can receive a callback at any time and from any state.</p>
   *
   * <p>If it's important for your app to respond to state changes (for instance, to update the
   * controls on a transport UI), you should register an
   * {@link EventCallback#onCallCompleted onCallCompleted} and
   * detect state change commands by testing the <code>what</code> parameter for a callback from one
   * of the state transition methods: {@link #CALL_COMPLETED_PREPARE}, {@link #CALL_COMPLETED_PLAY},
   * and {@link #CALL_COMPLETED_PAUSE}.
   * Then check the <code>status</code> parameter. The value {@link #CALL_STATUS_NO_ERROR} indicates a
   * successful transition. Any other value will be an error. Call {@link #getState()} to
   * determine the current state. </p>
   *
   * @hide
   */
  public class MediaPlayer2 implements AutoCloseable, AudioRouting {
      static {
          System.loadLibrary("media2_jni");
          native_init();
      }
  
      private static native void native_init();
  
      private static final int NEXT_SOURCE_STATE_ERROR = -1;
      private static final int NEXT_SOURCE_STATE_INIT = 0;
      private static final int NEXT_SOURCE_STATE_PREPARING = 1;
      private static final int NEXT_SOURCE_STATE_PREPARED = 2;
  
      private static final String TAG = "MediaPlayer2";
  
      private Context mContext;
  
      private long mNativeContext;  // accessed by native methods
      private long mNativeSurfaceTexture;  // accessed by native methods
      private int mListenerContext;  // accessed by native methods
      private SurfaceHolder mSurfaceHolder;
      private PowerManager.WakeLock mWakeLock = null;
      private boolean mScreenOnWhilePlaying;
      private boolean mStayAwake;
  
      private final Object mSrcLock = new Object();
      //--- guarded by |mSrcLock| start
      private SourceInfo mCurrentSourceInfo;
      private final Queue<SourceInfo> mNextSourceInfos = new ConcurrentLinkedQueue<>();
      //--- guarded by |mSrcLock| end
      private final AtomicLong mSrcIdGenerator = new AtomicLong(0);
  
      private volatile float mVolume = 1.0f;
      private Size mVideoSize = new Size(0, 0);
  
      private static ExecutorService sDrmThreadPool = Executors.newCachedThreadPool();
  
      // Creating a dummy audio track, used for keeping session id alive
      private final Object mSessionIdLock = new Object();
      @GuardedBy("mSessionIdLock")
      private AudioTrack mDummyAudioTrack;
  
      private HandlerThread mHandlerThread;
      private final TaskHandler mTaskHandler;
      private final Object mTaskLock = new Object();
      @GuardedBy("mTaskLock")
      private final List<Task> mPendingTasks = new LinkedList<>();
      @GuardedBy("mTaskLock")
      private Task mCurrentTask;
      private final AtomicLong mTaskIdGenerator = new AtomicLong(0);
  
      @GuardedBy("mTaskLock")
      boolean mIsPreviousCommandSeekTo = false;
      // |mPreviousSeekPos| and |mPreviousSeekMode| are valid only when |mIsPreviousCommandSeekTo|
      // is true, and they are accessed on |mHandlerThread| only.
      long mPreviousSeekPos = -1;
      int mPreviousSeekMode = SEEK_PREVIOUS_SYNC;
  
      @GuardedBy("this")
      private boolean mReleased;
  
      private final CloseGuard mGuard = CloseGuard.get();
  
      /**
       * Default constructor.
       * <p>When done with the MediaPlayer2, you should call {@link #close()},
       * to free the resources. If not released, too many MediaPlayer2 instances may
       * result in an exception.</p>
       */
      public MediaPlayer2(@NonNull Context context) {
          mGuard.open("close");
  
          mContext = context;
          mHandlerThread = new HandlerThread("MediaPlayer2TaskThread");
          mHandlerThread.start();
          Looper looper = mHandlerThread.getLooper();
          mTaskHandler = new TaskHandler(this, looper);
          AudioManager am = (AudioManager) context.getSystemService(Context.AUDIO_SERVICE);
          int sessionId = am.generateAudioSessionId();
          keepAudioSessionIdAlive(sessionId);
  
          /* Native setup requires a weak reference to our object.
           * It's easier to create it here than in C++.
           */
          native_setup(sessionId, new WeakReference<MediaPlayer2>(this));
      }
  
      private native void native_setup(int sessionId, Object mediaplayer2This);
  
      /**
       * Releases the resources held by this {@code MediaPlayer2} object.
       *
       * It is considered good practice to call this method when you're
       * done using the MediaPlayer2. In particular, whenever an Activity
       * of an application is paused (its onPause() method is called),
       * or stopped (its onStop() method is called), this method should be
       * invoked to release the MediaPlayer2 object, unless the application
       * has a special need to keep the object around. In addition to
       * unnecessary resources (such as memory and instances of codecs)
       * being held, failure to call this method immediately if a
       * MediaPlayer2 object is no longer needed may also lead to
       * continuous battery consumption for mobile devices, and playback
       * failure for other applications if no multiple instances of the
       * same codec are supported on a device. Even if multiple instances
       * of the same codec are supported, some performance degradation
       * may be expected when unnecessary multiple instances are used
       * at the same time.
       *
       * {@code close()} may be safely called after a prior {@code close()}.
       * This class implements the Java {@code AutoCloseable} interface and
       * may be used with try-with-resources.
       */
      // This is a synchronous call.
      @Override
      public void close() {
          synchronized (mGuard) {
              mGuard.close();
          }
          release();
      }
  
      private synchronized void release() {
          if (mReleased) {
              return;
          }
          stayAwake(false);
          updateSurfaceScreenOn();
          synchronized (mEventCbLock) {
              mEventCallbackRecords.clear();
          }
          if (mHandlerThread != null) {
              mHandlerThread.quitSafely();
              mHandlerThread = null;
          }
  
          clearSourceInfos();
  
          // Modular DRM clean up
          synchronized (mDrmEventCallbackLock) {
              mDrmEventCallback = null;
          }
          clearMediaDrmObjects();
  
          native_release();
  
          synchronized (mSessionIdLock) {
              mDummyAudioTrack.release();
          }
  
          mReleased = true;
      }
  
      void clearMediaDrmObjects() {
          Collection<MediaDrm> drmObjs = mDrmObjs.values();
          synchronized (mDrmObjs) {
              for (MediaDrm drmObj : drmObjs) {
                  drmObj.close();
              }
              mDrmObjs.clear();
          }
      }
  
      private native void native_release();
  
      // Have to declare protected for finalize() since it is protected
      // in the base class Object.
      @Override
      protected void finalize() throws Throwable {
          if (mGuard != null) {
              mGuard.warnIfOpen();
          }
  
          close();
          native_finalize();
      }
  
      private native void native_finalize();
  
      /**
       * Resets the MediaPlayer2 to its uninitialized state. After calling
       * this method, you will have to initialize it again by setting the
       * data source and calling prepare().
       */
      // This is a synchronous call.
      public void reset() {
          clearSourceInfos();
          clearMediaDrmObjects();
  
          stayAwake(false);
          native_reset();
  
          AudioManager am = (AudioManager) mContext.getSystemService(Context.AUDIO_SERVICE);
          int sessionId = am.generateAudioSessionId();
          keepAudioSessionIdAlive(sessionId);
  
          // make sure none of the listeners get called anymore
          if (mTaskHandler != null) {
              mTaskHandler.removeCallbacksAndMessages(null);
          }
  
      }
  
      private native void native_reset();
  
      /**
       * Starts or resumes playback. If playback had previously been paused,
       * playback will continue from where it was paused. If playback had
       * reached end of stream and been paused, or never started before,
       * playback will start at the beginning.
       *
       * @return a token which can be used to cancel the operation later with {@link #cancelCommand}.
       */
      // This is an asynchronous call.
      public @NonNull Object play() {
          return addTask(new Task(CALL_COMPLETED_PLAY, false) {
              @Override
              void process() {
                  stayAwake(true);
                  native_start();
              }
          });
      }
  
      private native void native_start() throws IllegalStateException;
  
      /**
       * Prepares the player for playback, asynchronously.
       *
       * After setting the datasource and the display surface, you need to call prepare().
       *
       * @return a token which can be used to cancel the operation later with {@link #cancelCommand}.
       */
      // This is an asynchronous call.
      public @NonNull Object prepare() {
          return addTask(new Task(CALL_COMPLETED_PREPARE, true) {
              @Override
              void process() {
                  native_prepare();
              }
          });
      }
  
      private native void native_prepare();
  
      /**
       * Pauses playback. Call play() to resume.
       * @return a token which can be used to cancel the operation later with {@link #cancelCommand}.
       */
      // This is an asynchronous call.
      public @NonNull Object pause() {
          return addTask(new Task(CALL_COMPLETED_PAUSE, false) {
              @Override
              void process() {
                  stayAwake(false);
  
                  native_pause();
              }
          });
      }
  
      private native void native_pause() throws IllegalStateException;
  
      /**
       * Tries to play next data source if applicable.
       * @return a token which can be used to cancel the operation later with {@link #cancelCommand}.
       */
      // This is an asynchronous call.
      public @NonNull Object skipToNext() {
          return addTask(new Task(CALL_COMPLETED_SKIP_TO_NEXT, false) {
              @Override
              void process() {
                  if (getState() == PLAYER_STATE_PLAYING) {
                      native_pause();
                  }
                  playNextDataSource();
              }
          });
      }
  
      /**
       * Gets the current playback position.
       *
       * @return the current position in milliseconds
       */
      public native long getCurrentPosition();
  
      /**
       * Gets the duration of the current data source.
       * Same as {@link #getDuration(DataSourceDesc)} with
       * {@code dsd = getCurrentDataSource()}.
       *
       * @return the duration in milliseconds, if no duration is available
       *         (for example, if streaming live content), -1 is returned.
       * @throws NullPointerException if current data source is null
       */
      public long getDuration() {
          return getDuration(getCurrentDataSource());
      }
  
      /**
       * Gets the duration of the dsd.
       *
       * @param dsd the descriptor of data source of which you want to get duration
       * @return the duration in milliseconds, if no duration is available
       *         (for example, if streaming live content), -1 is returned.
       * @throws NullPointerException if dsd is null
       */
      public long getDuration(@NonNull DataSourceDesc dsd) {
          if (dsd == null) {
              throw new NullPointerException("non-null dsd is expected");
          }
          SourceInfo sourceInfo = getSourceInfo(dsd);
          if (sourceInfo == null) {
              return -1;
          }
  
          return native_getDuration(sourceInfo.mId);
      }
  
      private native long native_getDuration(long srcId);
  
      /**
       * Gets the buffered media source position of current data source.
       * Same as {@link #getBufferedPosition(DataSourceDesc)} with
       * {@code dsd = getCurrentDataSource()}.
       *
       * @return the current buffered media source position in milliseconds
       * @throws NullPointerException if current data source is null
       */
      public long getBufferedPosition() {
          return getBufferedPosition(getCurrentDataSource());
      }
  
      /**
       * Gets the buffered media source position of given dsd.
       * For example a buffering update of 8000 milliseconds when 5000 milliseconds of the content
       * has already been played indicates that the next 3000 milliseconds of the
       * content to play has been buffered.
       *
       * @param dsd the descriptor of data source of which you want to get buffered position
       * @return the current buffered media source position in milliseconds
       * @throws NullPointerException if dsd is null
       */
      public long getBufferedPosition(@NonNull DataSourceDesc dsd) {
          if (dsd == null) {
              throw new NullPointerException("non-null dsd is expected");
          }
          SourceInfo sourceInfo = getSourceInfo(dsd);
          if (sourceInfo == null) {
              return 0;
          }
  
          // Use cached buffered percent for now.
          int bufferedPercentage = sourceInfo.mBufferedPercentage.get();
  
          long duration = getDuration(dsd);
          if (duration < 0) {
              duration = 0;
          }
  
          return duration * bufferedPercentage / 100;
      }
  
      /**
       * MediaPlayer2 has not been prepared or just has been reset.
       * In this state, MediaPlayer2 doesn't fetch data.
       */
      public static final int PLAYER_STATE_IDLE = 1001;
  
      /**
       * MediaPlayer2 has been just prepared.
       * In this state, MediaPlayer2 just fetches data from media source,
       * but doesn't actively render data.
       */
      public static final int PLAYER_STATE_PREPARED = 1002;
  
      /**
       * MediaPlayer2 is paused.
       * In this state, MediaPlayer2 has allocated resources to construct playback
       * pipeline, but it doesn't actively render data.
       */
      public static final int PLAYER_STATE_PAUSED = 1003;
  
      /**
       * MediaPlayer2 is actively playing back data.
       */
      public static final int PLAYER_STATE_PLAYING = 1004;
  
      /**
       * MediaPlayer2 has hit some fatal error and cannot continue playback.
       */
      public static final int PLAYER_STATE_ERROR = 1005;
  
      /**
       * @hide
       */
      @IntDef(flag = false, prefix = "MEDIAPLAYER2_STATE", value = {
          PLAYER_STATE_IDLE,
          PLAYER_STATE_PREPARED,
          PLAYER_STATE_PAUSED,
          PLAYER_STATE_PLAYING,
          PLAYER_STATE_ERROR })
      @Retention(RetentionPolicy.SOURCE)
      public @interface MediaPlayer2State {}
  
      /**
       * Gets the current player state.
       *
       * @return the current player state.
       */
      public @MediaPlayer2State int getState() {
          return native_getState();
      }
  
      private native int native_getState();
  
      /**
       * Sets the audio attributes for this MediaPlayer2.
       * See {@link AudioAttributes} for how to build and configure an instance of this class.
       * You must call this method before {@link #play()} and {@link #pause()} in order
       * for the audio attributes to become effective thereafter.
       * @param attributes a non-null set of audio attributes
       * @return a token which can be used to cancel the operation later with {@link #cancelCommand}.
       */
      // This is an asynchronous call.
      public @NonNull Object setAudioAttributes(@NonNull AudioAttributes attributes) {
          return addTask(new Task(CALL_COMPLETED_SET_AUDIO_ATTRIBUTES, false) {
              @Override
              void process() {
                  if (attributes == null) {
                      final String msg = "Cannot set AudioAttributes to null";
                      throw new IllegalArgumentException(msg);
                  }
                  native_setAudioAttributes(attributes);
              }
          });
      }
  
      // return true if the parameter is set successfully, false otherwise
      private native boolean native_setAudioAttributes(AudioAttributes audioAttributes);
  
      /**
       * Gets the audio attributes for this MediaPlayer2.
       * @return attributes a set of audio attributes
       */
      public @NonNull AudioAttributes getAudioAttributes() {
          return native_getAudioAttributes();
      }
  
      private native AudioAttributes native_getAudioAttributes();
  
      /**
       * Sets the data source as described by a DataSourceDesc.
       * When the data source is of {@link FileDataSourceDesc} type, the {@link ParcelFileDescriptor}
       * in the {@link FileDataSourceDesc} will be closed by the player.
       *
       * @param dsd the descriptor of data source you want to play
       * @return a token which can be used to cancel the operation later with {@link #cancelCommand}.
       */
      // This is an asynchronous call.
      public @NonNull Object setDataSource(@NonNull DataSourceDesc dsd) {
          return addTask(new Task(CALL_COMPLETED_SET_DATA_SOURCE, false) {
              @Override
              void process() throws IOException {
                  checkDataSourceDesc(dsd);
                  int state = getState();
                  try {
                      if (state != PLAYER_STATE_ERROR && state != PLAYER_STATE_IDLE) {
                          throw new IllegalStateException("called in wrong state " + state);
                      }
  
                      synchronized (mSrcLock) {
                          setCurrentSourceInfo_l(new SourceInfo(dsd));
                          handleDataSource(true /* isCurrent */, dsd, mCurrentSourceInfo.mId);
                      }
                  } finally {
                      dsd.close();
                  }
              }
  
          });
      }
  
      /**
       * Sets a single data source as described by a DataSourceDesc which will be played
       * after current data source is finished.
       * When the data source is of {@link FileDataSourceDesc} type, the {@link ParcelFileDescriptor}
       * in the {@link FileDataSourceDesc} will be closed by the player.
       *
       * @param dsd the descriptor of data source you want to play after current one
       * @return a token which can be used to cancel the operation later with {@link #cancelCommand}.
       */
      // This is an asynchronous call.
      public @NonNull Object setNextDataSource(@NonNull DataSourceDesc dsd) {
          return addTask(new Task(CALL_COMPLETED_SET_NEXT_DATA_SOURCE, false) {
              @Override
              void process() {
                  checkDataSourceDesc(dsd);
                  synchronized (mSrcLock) {
                      clearNextSourceInfos_l();
                      mNextSourceInfos.add(new SourceInfo(dsd));
                  }
                  prepareNextDataSource();
              }
          });
      }
  
      /**
       * Sets a list of data sources to be played sequentially after current data source is done.
       * When the data source is of {@link FileDataSourceDesc} type, the {@link ParcelFileDescriptor}
       * in the {@link FileDataSourceDesc} will be closed by the player.
       *
       * @param dsds the list of data sources you want to play after current one
       * @return a token which can be used to cancel the operation later with {@link #cancelCommand}.
       */
      // This is an asynchronous call.
      public @NonNull Object setNextDataSources(@NonNull List<DataSourceDesc> dsds) {
          return addTask(new Task(CALL_COMPLETED_SET_NEXT_DATA_SOURCES, false) {
              @Override
              void process() {
                  if (dsds == null || dsds.size() == 0) {
                      throw new IllegalArgumentException("data source list cannot be null or empty.");
                  }
                  boolean hasError = false;
                  for (DataSourceDesc dsd : dsds) {
                      if (dsd == null) {
                          hasError = true;
                          continue;
                      }
                      if (dsd instanceof FileDataSourceDesc) {
                          FileDataSourceDesc fdsd = (FileDataSourceDesc) dsd;
                          if (fdsd.isPFDClosed()) {
                              hasError = true;
                              continue;
                          }
  
                          fdsd.incCount();
                      }
                  }
                  if (hasError) {
                      for (DataSourceDesc dsd : dsds) {
                          if (dsd != null) {
                              dsd.close();
                          }
                      }
                      throw new IllegalArgumentException("invalid data source list");
                  }
  
                  synchronized (mSrcLock) {
                      clearNextSourceInfos_l();
                      for (DataSourceDesc dsd : dsds) {
                          mNextSourceInfos.add(new SourceInfo(dsd));
                      }
                  }
                  prepareNextDataSource();
              }
          });
      }
  
      // throws IllegalArgumentException if dsd is null or underline PFD of dsd has been closed.
      private void checkDataSourceDesc(DataSourceDesc dsd) {
          if (dsd == null) {
              throw new IllegalArgumentException("dsd is expected to be non null");
          }
          if (dsd instanceof FileDataSourceDesc) {
              FileDataSourceDesc fdsd = (FileDataSourceDesc) dsd;
              if (fdsd.isPFDClosed()) {
                  throw new IllegalArgumentException("the underline FileDescriptor has been closed");
              }
              fdsd.incCount();
          }
      }
  
      /**
       * Removes all data sources pending to be played.
       * @return a token which can be used to cancel the operation later with {@link #cancelCommand}.
       */
      // This is an asynchronous call.
      public @NonNull Object clearNextDataSources() {
          return addTask(new Task(CALL_COMPLETED_CLEAR_NEXT_DATA_SOURCES, false) {
              @Override
              void process() {
                  synchronized (mSrcLock) {
                      clearNextSourceInfos_l();
                  }
              }
          });
      }
  
      /**
       * Gets the current data source as described by a DataSourceDesc.
       *
       * @return the current DataSourceDesc
       */
      public @Nullable DataSourceDesc getCurrentDataSource() {
          synchronized (mSrcLock) {
              return mCurrentSourceInfo == null ? null : mCurrentSourceInfo.mDSD;
          }
      }
  
      private void handleDataSource(boolean isCurrent, @NonNull DataSourceDesc dsd, long srcId)
              throws IOException {
          Media2Utils.checkArgument(dsd != null, "the DataSourceDesc cannot be null");
  
          if (dsd instanceof FileDataSourceDesc) {
              FileDataSourceDesc fileDSD = (FileDataSourceDesc) dsd;
              ParcelFileDescriptor pfd = fileDSD.getParcelFileDescriptor();
              if (pfd.getStatSize() == -1) {
                  // Underlying pipeline doesn't understand '-1' size. Create a wrapper for
                  // translation.
                  // TODO: Make native code handle '-1' size.
                  handleDataSource(isCurrent,
                          srcId,
                          new ProxyDataSourceCallback(pfd),
                          fileDSD.getStartPosition(),
                          fileDSD.getEndPosition());
              } else {
                  handleDataSource(isCurrent,
                          srcId,
                          pfd,
                          fileDSD.getOffset(),
                          fileDSD.getLength(),
                          fileDSD.getStartPosition(),
                          fileDSD.getEndPosition());
              }
          } else if (dsd instanceof UriDataSourceDesc) {
              UriDataSourceDesc uriDSD = (UriDataSourceDesc) dsd;
              handleDataSource(isCurrent,
                               srcId,
                               mContext,
                               uriDSD.getUri(),
                               uriDSD.getHeaders(),
                               uriDSD.getCookies(),
                               uriDSD.getStartPosition(),
                               uriDSD.getEndPosition());
          } else {
              throw new IllegalArgumentException("Unsupported DataSourceDesc. " + dsd.toString());
          }
      }
  
      /**
       * To provide cookies for the subsequent HTTP requests, you can install your own default cookie
       * handler and use other variants of setDataSource APIs instead. Alternatively, you can use
       * this API to pass the cookies as a list of HttpCookie. If the app has not installed
       * a CookieHandler already, this API creates a CookieManager and populates its CookieStore with
       * the provided cookies. If the app has installed its own handler already, this API requires the
       * handler to be of CookieManager type such that the API can update the manager’s CookieStore.
       *
       * <p><strong>Note</strong> that the cross domain redirection is allowed by default,
       * but that can be changed with key/value pairs through the headers parameter with
       * "android-allow-cross-domain-redirect" as the key and "0" or "1" as the value to
       * disallow or allow cross domain redirection.
       *
       * @throws IllegalArgumentException if cookies are provided and the installed handler is not
       *                                  a CookieManager
       * @throws IllegalStateException    if it is called in an invalid state
       * @throws NullPointerException     if context or uri is null
       * @throws IOException              if uri has a file scheme and an I/O error occurs
       */
      private void handleDataSource(
              boolean isCurrent, long srcId,
              @NonNull Context context, @NonNull Uri uri,
              @Nullable Map<String, String> headers, @Nullable List<HttpCookie> cookies,
              long startPos, long endPos)
              throws IOException {
          // The context and URI usually belong to the calling user. Get a resolver for that user.
          final ContentResolver resolver = context.getContentResolver();
          final String scheme = uri.getScheme();
          if (ContentResolver.SCHEME_FILE.equals(scheme)) {
              handleDataSource(isCurrent, srcId, uri.getPath(), null, null, startPos, endPos);
              return;
          }
  
          final int ringToneType = RingtoneManager.getDefaultType(uri);
          try {
              AssetFileDescriptor afd;
              // Try requested Uri locally first
              if (ContentResolver.SCHEME_CONTENT.equals(scheme) && ringToneType != -1) {
                  afd = RingtoneManager.openDefaultRingtoneUri(context, uri);
                  if (attemptDataSource(isCurrent, srcId, afd, startPos, endPos)) {
                      return;
                  }
                  final Uri actualUri = RingtoneManager.getActualDefaultRingtoneUri(
                          context, ringToneType);
                  afd = resolver.openAssetFileDescriptor(actualUri, "r");
              } else {
                  afd = resolver.openAssetFileDescriptor(uri, "r");
              }
              if (attemptDataSource(isCurrent, srcId, afd, startPos, endPos)) {
                  return;
              }
          } catch (NullPointerException | SecurityException | IOException ex) {
              Log.w(TAG, "Couldn't open " + uri == null ? "null uri" : uri.toSafeString(), ex);
              // Fallback to media server
          }
          handleDataSource(isCurrent, srcId, uri.toString(), headers, cookies, startPos, endPos);
      }
  
      private boolean attemptDataSource(boolean isCurrent, long srcId, AssetFileDescriptor afd,
              long startPos, long endPos) throws IOException {
          try {
              if (afd.getDeclaredLength() < 0) {
                  handleDataSource(isCurrent,
                          srcId,
                          ParcelFileDescriptor.dup(afd.getFileDescriptor()),
                          0,
                          DataSourceDesc.LONG_MAX,
                          startPos,
                          endPos);
              } else {
                  handleDataSource(isCurrent,
                          srcId,
                          ParcelFileDescriptor.dup(afd.getFileDescriptor()),
                          afd.getStartOffset(),
                          afd.getDeclaredLength(),
                          startPos,
                          endPos);
              }
              return true;
          } catch (NullPointerException | SecurityException | IOException ex) {
              Log.w(TAG, "Couldn't open srcId:" + srcId + ": " + ex);
              return false;
          } finally {
              if (afd != null) {
                  afd.close();
              }
          }
      }
  
      private void handleDataSource(
              boolean isCurrent, long srcId,
              String path, Map<String, String> headers, List<HttpCookie> cookies,
              long startPos, long endPos)
              throws IOException {
          String[] keys = null;
          String[] values = null;
  
          if (headers != null) {
              keys = new String[headers.size()];
              values = new String[headers.size()];
  
              int i = 0;
              for (Map.Entry<String, String> entry: headers.entrySet()) {
                  keys[i] = entry.getKey();
                  values[i] = entry.getValue();
                  ++i;
              }
          }
          handleDataSource(isCurrent, srcId, path, keys, values, cookies, startPos, endPos);
      }
  
      private void handleDataSource(boolean isCurrent, long srcId,
              String path, String[] keys, String[] values, List<HttpCookie> cookies,
              long startPos, long endPos)
              throws IOException {
          final Uri uri = Uri.parse(path);
          final String scheme = uri.getScheme();
          if ("file".equals(scheme)) {
              path = uri.getPath();
          } else if (scheme != null) {
              // handle non-file sources
              Media2Utils.storeCookies(cookies);
              nativeHandleDataSourceUrl(
                      isCurrent,
                      srcId,
                      Media2HTTPService.createHTTPService(path),
                      path,
                      keys,
                      values,
                      startPos,
                      endPos);
              return;
          }
  
          final File file = new File(path);
          if (file.exists()) {
              FileInputStream is = new FileInputStream(file);
              FileDescriptor fd = is.getFD();
              handleDataSource(isCurrent, srcId, ParcelFileDescriptor.dup(fd),
                      0, DataSourceDesc.LONG_MAX, startPos, endPos);
              is.close();
          } else {
              throw new IOException("handleDataSource failed.");
          }
      }
  
      private native void nativeHandleDataSourceUrl(
              boolean isCurrent, long srcId,
              Media2HTTPService httpService, String path, String[] keys, String[] values,
              long startPos, long endPos)
              throws IOException;
  
      /**
       * Sets the data source (FileDescriptor) to use. The FileDescriptor must be
       * seekable (N.B. a LocalSocket is not seekable). It is the caller's responsibility
       * to close the file descriptor. It is safe to do so as soon as this call returns.
       *
       * @throws IllegalStateException if it is called in an invalid state
       * @throws IllegalArgumentException if fd is not a valid FileDescriptor
       * @throws IOException if fd can not be read
       */
      private void handleDataSource(
              boolean isCurrent, long srcId,
              ParcelFileDescriptor pfd, long offset, long length,
              long startPos, long endPos) throws IOException {
          nativeHandleDataSourceFD(isCurrent, srcId, pfd.getFileDescriptor(), offset, length,
                  startPos, endPos);
      }
  
      private native void nativeHandleDataSourceFD(boolean isCurrent, long srcId,
              FileDescriptor fd, long offset, long length,
              long startPos, long endPos) throws IOException;
  
      /**
       * @throws IllegalStateException if it is called in an invalid state
       * @throws IllegalArgumentException if dataSource is not a valid DataSourceCallback
       */
      private void handleDataSource(boolean isCurrent, long srcId, DataSourceCallback dataSource,
              long startPos, long endPos) {
          nativeHandleDataSourceCallback(isCurrent, srcId, dataSource, startPos, endPos);
      }
  
      private native void nativeHandleDataSourceCallback(
              boolean isCurrent, long srcId, DataSourceCallback dataSource,
              long startPos, long endPos);
  
      // return true if there is a next data source, false otherwise.
      // This function should be always called on |mHandlerThread|.
      private boolean prepareNextDataSource() {
          HandlerThread handlerThread = mHandlerThread;
          if (handlerThread != null && Looper.myLooper() != handlerThread.getLooper()) {
              Log.e(TAG, "prepareNextDataSource: called on wrong looper");
          }
  
          boolean hasNextDSD;
          int state = getState();
          synchronized (mSrcLock) {
              hasNextDSD = !mNextSourceInfos.isEmpty();
              if (state == PLAYER_STATE_ERROR || state == PLAYER_STATE_IDLE) {
                  // Current source has not been prepared yet.
                  return hasNextDSD;
              }
  
              SourceInfo nextSource = mNextSourceInfos.peek();
              if (!hasNextDSD || nextSource.mStateAsNextSource != NEXT_SOURCE_STATE_INIT) {
                  // There is no next source or it's in preparing or prepared state.
                  return hasNextDSD;
              }
  
              try {
                  nextSource.mStateAsNextSource = NEXT_SOURCE_STATE_PREPARING;
                  handleDataSource(false /* isCurrent */, nextSource.mDSD, nextSource.mId);
              } catch (Exception e) {
                  Message msg = mTaskHandler.obtainMessage(
                          MEDIA_ERROR, MEDIA_ERROR_IO, MEDIA_ERROR_UNKNOWN, null);
                  mTaskHandler.handleMessage(msg, nextSource.mId);
  
                  SourceInfo nextSourceInfo = mNextSourceInfos.poll();
                  if (nextSource != null) {
                      nextSourceInfo.close();
                  }
                  return prepareNextDataSource();
              }
          }
          return hasNextDSD;
      }
  
      // This function should be always called on |mHandlerThread|.
      private void playNextDataSource() {
          HandlerThread handlerThread = mHandlerThread;
          if (handlerThread != null && Looper.myLooper() != handlerThread.getLooper()) {
              Log.e(TAG, "playNextDataSource: called on wrong looper");
          }
  
          boolean hasNextDSD = false;
          synchronized (mSrcLock) {
              if (!mNextSourceInfos.isEmpty()) {
                  hasNextDSD = true;
                  SourceInfo nextSourceInfo = mNextSourceInfos.peek();
                  if (nextSourceInfo.mStateAsNextSource == NEXT_SOURCE_STATE_PREPARED) {
                      // Switch to next source only when it has been prepared.
                      setCurrentSourceInfo_l(mNextSourceInfos.poll());
  
                      long srcId = mCurrentSourceInfo.mId;
                      try {
                          nativePlayNextDataSource(srcId);
                      } catch (Exception e) {
                          Message msg2 = mTaskHandler.obtainMessage(
                                  MEDIA_ERROR, MEDIA_ERROR_UNKNOWN, MEDIA_ERROR_UNSUPPORTED, null);
                          mTaskHandler.handleMessage(msg2, srcId);
                          // Keep |mNextSourcePlayPending|
                          hasNextDSD = prepareNextDataSource();
                      }
                      if (hasNextDSD) {
                          stayAwake(true);
  
                          // Now a new current src is playing.
                          // Wait for MEDIA_INFO_DATA_SOURCE_START to prepare next source.
                      }
                  } else if (nextSourceInfo.mStateAsNextSource == NEXT_SOURCE_STATE_INIT) {
                      hasNextDSD = prepareNextDataSource();
                  }
              }
          }
  
          if (!hasNextDSD) {
              sendEvent(new EventNotifier() {
                  @Override
                  public void notify(EventCallback callback) {
                      callback.onInfo(
                              MediaPlayer2.this, null, MEDIA_INFO_DATA_SOURCE_LIST_END, 0);
                  }
              });
          }
      }
  
      private native void nativePlayNextDataSource(long srcId);
  
      /**
       * Configures the player to loop on the current data source.
       * @param loop true if the current data source is meant to loop.
       * @return a token which can be used to cancel the operation later with {@link #cancelCommand}.
       */
      // This is an asynchronous call.
      public @NonNull Object loopCurrent(boolean loop) {
          return addTask(new Task(CALL_COMPLETED_LOOP_CURRENT, false) {
              @Override
              void process() {
                  setLooping(loop);
              }
          });
      }
  
      private native void setLooping(boolean looping);
  
      /**
       * Sets the volume of the audio of the media to play, expressed as a linear multiplier
       * on the audio samples.
       * Note that this volume is specific to the player, and is separate from stream volume
       * used across the platform.<br>
       * A value of 0.0f indicates muting, a value of 1.0f is the nominal unattenuated and unamplified
       * gain. See {@link #getMaxPlayerVolume()} for the volume range supported by this player.
       * @param volume a value between 0.0f and {@link #getMaxPlayerVolume()}.
       * @return a token which can be used to cancel the operation later with {@link #cancelCommand}.
       */
      // This is an asynchronous call.
      public @NonNull Object setPlayerVolume(float volume) {
          return addTask(new Task(CALL_COMPLETED_SET_PLAYER_VOLUME, false) {
              @Override
              void process() {
                  mVolume = volume;
                  native_setVolume(volume);
              }
          });
      }
  
      private native void native_setVolume(float volume);
  
      /**
       * Returns the current volume of this player.
       * Note that it does not take into account the associated stream volume.
       * @return the player volume.
       */
      public float getPlayerVolume() {
          return mVolume;
      }
  
      /**
       * @return the maximum volume that can be used in {@link #setPlayerVolume(float)}.
       */
      public float getMaxPlayerVolume() {
          return 1.0f;
      }
  
      /**
       * Insert a task in the command queue to help the client to identify whether a batch
       * of commands has been finished. When this command is processed, a notification
       * {@link EventCallback#onCommandLabelReached onCommandLabelReached} will be fired with the
       * given {@code label}.
       *
       * @see EventCallback#onCommandLabelReached
       *
       * @param label An application specific Object used to help to identify the completeness
       * of a batch of commands.
       * @return a token which can be used to cancel the operation later with {@link #cancelCommand}.
       */
      // This is an asynchronous call.
      public @NonNull Object notifyWhenCommandLabelReached(@NonNull Object label) {
          return addTask(new Task(CALL_COMPLETED_NOTIFY_WHEN_COMMAND_LABEL_REACHED, false) {
              @Override
              void process() {
                  sendEvent(new EventNotifier() {
                      @Override
                      public void notify(EventCallback callback) {
                          callback.onCommandLabelReached(
                                  MediaPlayer2.this, label);
                      }
                  });
              }
          });
      }
  
      /**
       * Sets the {@link SurfaceHolder} to use for displaying the video
       * portion of the media.
       *
       * Either a surface holder or surface must be set if a display or video sink
       * is needed. Not calling this method or {@link #setSurface(Surface)}
       * when playing back a video will result in only the audio track being played.
       * A null surface holder or surface will result in only the audio track being
       * played.
       *
       * @param sh the SurfaceHolder to use for video display
       * @return a token which can be used to cancel the operation later with {@link #cancelCommand}.
       */
      public @NonNull Object setDisplay(@Nullable SurfaceHolder sh) {
          return addTask(new Task(CALL_COMPLETED_SET_DISPLAY, false) {
              @Override
              void process() {
                  mSurfaceHolder = sh;
                  Surface surface;
                  if (sh != null) {
                      surface = sh.getSurface();
                  } else {
                      surface = null;
                  }
                  native_setVideoSurface(surface);
                  updateSurfaceScreenOn();
              }
          });
      }
  
      /**
       * Sets the {@link Surface} to be used as the sink for the video portion of
       * the media.  Setting a
       * Surface will un-set any Surface or SurfaceHolder that was previously set.
       * A null surface will result in only the audio track being played.
       *
       * If the Surface sends frames to a {@link SurfaceTexture}, the timestamps
       * returned from {@link SurfaceTexture#getTimestamp()} will have an
       * unspecified zero point.  These timestamps cannot be directly compared
       * between different media sources, different instances of the same media
       * source, or multiple runs of the same program.  The timestamp is normally
       * monotonically increasing and is unaffected by time-of-day adjustments,
       * but it is reset when the position is set.
       *
       * @param surface The {@link Surface} to be used for the video portion of
       * the media.
       * @return a token which can be used to cancel the operation later with {@link #cancelCommand}.
       */
      // This is an asynchronous call.
      public @NonNull Object setSurface(@Nullable Surface surface) {
          return addTask(new Task(CALL_COMPLETED_SET_SURFACE, false) {
              @Override
              void process() {
                  if (mScreenOnWhilePlaying && surface != null) {
                      Log.w(TAG, "setScreenOnWhilePlaying(true) is ineffective for Surface");
                  }
                  mSurfaceHolder = null;
                  native_setVideoSurface(surface);
                  updateSurfaceScreenOn();
              }
          });
      }
  
      private native void native_setVideoSurface(Surface surface);
  
      /**
       * Set the low-level power management behavior for this MediaPlayer2. This
       * can be used when the MediaPlayer2 is not playing through a SurfaceHolder
       * set with {@link #setDisplay(SurfaceHolder)} and thus can use the
       * high-level {@link #setScreenOnWhilePlaying(boolean)} feature.
       *
       * <p>This function has the MediaPlayer2 access the low-level power manager
       * service to control the device's power usage while playing is occurring.
       * The parameter is a {@link android.os.PowerManager.WakeLock}.
       * Use of this method requires {@link android.Manifest.permission#WAKE_LOCK}
       * permission.
       * By default, no attempt is made to keep the device awake during playback.
       *
       * @param wakeLock the power wake lock used during playback.
       * @return a token which can be used to cancel the operation later with {@link #cancelCommand}.
       * @see android.os.PowerManager
       */
      // This is an asynchronous call.
      public @NonNull Object setWakeLock(@NonNull PowerManager.WakeLock wakeLock) {
          return addTask(new Task(CALL_COMPLETED_SET_WAKE_LOCK, false) {
              @Override
              void process() {
                  boolean wasHeld = false;
  
                  if (mWakeLock != null) {
                      if (mWakeLock.isHeld()) {
                          wasHeld = true;
                          mWakeLock.release();
                      }
                  }
  
                  mWakeLock = wakeLock;
                  if (mWakeLock != null) {
                      mWakeLock.setReferenceCounted(false);
                      if (wasHeld) {
                          mWakeLock.acquire();
                      }
                  }
              }
          });
      }
  
      /**
       * Control whether we should use the attached SurfaceHolder to keep the
       * screen on while video playback is occurring.  This is the preferred
       * method over {@link #setWakeLock} where possible, since it doesn't
       * require that the application have permission for low-level wake lock
       * access.
       *
       * @param screenOn Supply true to keep the screen on, false to allow it to turn off.
       * @return a token which can be used to cancel the operation later with {@link #cancelCommand}.
       */
      // This is an asynchronous call.
      public @NonNull Object setScreenOnWhilePlaying(boolean screenOn) {
          return addTask(new Task(CALL_COMPLETED_SET_SCREEN_ON_WHILE_PLAYING, false) {
              @Override
              void process() {
                  if (mScreenOnWhilePlaying != screenOn) {
                      if (screenOn && mSurfaceHolder == null) {
                          Log.w(TAG, "setScreenOnWhilePlaying(true) is ineffective"
                                  + " without a SurfaceHolder");
                      }
                      mScreenOnWhilePlaying = screenOn;
                      updateSurfaceScreenOn();
                  }
              }
          });
      }
  
      private void stayAwake(boolean awake) {
          if (mWakeLock != null) {
              if (awake && !mWakeLock.isHeld()) {
                  mWakeLock.acquire();
              } else if (!awake && mWakeLock.isHeld()) {
                  mWakeLock.release();
              }
          }
          mStayAwake = awake;
          updateSurfaceScreenOn();
      }
  
      private void updateSurfaceScreenOn() {
          if (mSurfaceHolder != null) {
              mSurfaceHolder.setKeepScreenOn(mScreenOnWhilePlaying && mStayAwake);
          }
      }
  
      /**
       * Cancels a pending command.
       *
       * @param token the command to be canceled. This is the returned Object when command is issued.
       * @return {@code false} if the task could not be cancelled; {@code true} otherwise.
       * @throws IllegalArgumentException if argument token is null.
       */
      // This is a synchronous call.
      public boolean cancelCommand(@NonNull Object token) {
          if (token == null) {
              throw new IllegalArgumentException("command token should not be null");
          }
          synchronized (mTaskLock) {
              return mPendingTasks.remove(token);
          }
      }
  
      /**
       * Discards all pending commands.
       */
      // This is a synchronous call.
      public void clearPendingCommands() {
          synchronized (mTaskLock) {
              mPendingTasks.clear();
          }
      }
  
      //--------------------------------------------------------------------------
      // Explicit Routing
      //--------------------
      private AudioDeviceInfo mPreferredDevice = null;
  
      /**
       * Specifies an audio device (via an {@link AudioDeviceInfo} object) to route
       * the output from this MediaPlayer2.
       * @param deviceInfo The {@link AudioDeviceInfo} specifying the audio sink or source.
       *  If deviceInfo is null, default routing is restored.
       * @return true if succesful, false if the specified {@link AudioDeviceInfo} is non-null and
       * does not correspond to a valid audio device.
       */
      // This is a synchronous call.
      @Override
      public boolean setPreferredDevice(@Nullable AudioDeviceInfo deviceInfo) {
          boolean status = native_setPreferredDevice(deviceInfo);
          if (status) {
              synchronized (this) {
                  mPreferredDevice = deviceInfo;
              }
          }
          return status;
      }
  
      private native boolean native_setPreferredDevice(AudioDeviceInfo device);
  
      /**
       * Returns the selected output specified by {@link #setPreferredDevice}. Note that this
       * is not guaranteed to correspond to the actual device being used for playback.
       */
      @Override
      public @Nullable AudioDeviceInfo getPreferredDevice() {
          synchronized (this) {
              return mPreferredDevice;
          }
      }
  
      /**
       * Returns an {@link AudioDeviceInfo} identifying the current routing of this MediaPlayer2
       * Note: The query is only valid if the MediaPlayer2 is currently playing.
       * If the player is not playing, the returned device can be null or correspond to previously
       * selected device when the player was last active.
       */
      @Override
      public @Nullable native AudioDeviceInfo getRoutedDevice();
  
      /**
       * Adds an {@link AudioRouting.OnRoutingChangedListener} to receive notifications of routing
       * changes on this MediaPlayer2.
       * @param listener The {@link AudioRouting.OnRoutingChangedListener} interface to receive
       * notifications of rerouting events.
       * @param handler  Specifies the {@link Handler} object for the thread on which to execute
       * the callback. If <code>null</code>, the handler on the main looper will be used.
       */
      // This is a synchronous call.
      @Override
      public void addOnRoutingChangedListener(@NonNull AudioRouting.OnRoutingChangedListener listener,
              @Nullable Handler handler) {
          if (listener == null) {
              throw new IllegalArgumentException("addOnRoutingChangedListener: listener is NULL");
          }
          RoutingDelegate routingDelegate = new RoutingDelegate(this, listener, handler);
          native_addDeviceCallback(routingDelegate);
      }
  
      private native void native_addDeviceCallback(RoutingDelegate rd);
  
      /**
       * Removes an {@link AudioRouting.OnRoutingChangedListener} which has been previously added
       * to receive rerouting notifications.
       * @param listener The previously added {@link AudioRouting.OnRoutingChangedListener} interface
       * to remove.
       */
      // This is a synchronous call.
      @Override
      public void removeOnRoutingChangedListener(
              @NonNull AudioRouting.OnRoutingChangedListener listener) {
          if (listener == null) {
              throw new IllegalArgumentException("removeOnRoutingChangedListener: listener is NULL");
          }
          native_removeDeviceCallback(listener);
      }
  
      private native void native_removeDeviceCallback(
              AudioRouting.OnRoutingChangedListener listener);
  
      /**
       * Returns the size of the video.
       *
       * @return the size of the video. The width and height of size could be 0 if there is no video,
       * or the size has not been determined yet.
       * The {@code EventCallback} can be registered via
       * {@link #registerEventCallback(Executor, EventCallback)} to provide a
       * notification {@code EventCallback.onVideoSizeChanged} when the size
       * is available.
       */
      public @NonNull Size getVideoSize() {
          return mVideoSize;
      }
  
      /**
       * Return Metrics data about the current player.
       *
       * @return a {@link PersistableBundle} containing the set of attributes and values
       * available for the media being handled by this instance of MediaPlayer2
       * The attributes are descibed in {@link MetricsConstants}.
       *
       * Additional vendor-specific fields may also be present in the return value.
       */
      public @Nullable PersistableBundle getMetrics() {
          PersistableBundle bundle = native_getMetrics();
          return bundle;
      }
  
      private native PersistableBundle native_getMetrics();
  
      /**
       * Gets the current buffering management params used by the source component.
       * Calling it only after {@code setDataSource} has been called.
       * Each type of data source might have different set of default params.
       *
       * @return the current buffering management params used by the source component.
       * @throws IllegalStateException if the internal player engine has not been
       * initialized, or {@code setDataSource} has not been called.
       */
      // TODO: make it public when ready
      @NonNull
      native BufferingParams getBufferingParams();
  
      /**
       * Sets buffering management params.
       * The object sets its internal BufferingParams to the input, except that the input is
       * invalid or not supported.
       * Call it only after {@code setDataSource} has been called.
       * The input is a hint to MediaPlayer2.
       *
       * @param params the buffering management params.
       * @return a token which can be used to cancel the operation later with {@link #cancelCommand}.
       */
      // TODO: make it public when ready
      // This is an asynchronous call.
      @NonNull Object setBufferingParams(@NonNull BufferingParams params) {
          return addTask(new Task(CALL_COMPLETED_SET_BUFFERING_PARAMS, false) {
              @Override
              void process() {
                  Media2Utils.checkArgument(params != null, "the BufferingParams cannot be null");
                  native_setBufferingParams(params);
              }
          });
      }
  
      private native void native_setBufferingParams(@NonNull BufferingParams params);
  
      /**
       * Sets playback rate using {@link PlaybackParams}. The object sets its internal
       * PlaybackParams to the input. This allows the object to resume at previous speed
       * when play() is called. Speed of zero is not allowed. Calling it does not change
       * the object state.
       *
       * @param params the playback params.
       * @return a token which can be used to cancel the operation later with {@link #cancelCommand}.
       */
      // This is an asynchronous call.
      public @NonNull Object setPlaybackParams(@NonNull PlaybackParams params) {
          return addTask(new Task(CALL_COMPLETED_SET_PLAYBACK_PARAMS, false) {
              @Override
              void process() {
                  Media2Utils.checkArgument(params != null, "the PlaybackParams cannot be null");
                  native_setPlaybackParams(params);
              }
          });
      }
  
      private native void native_setPlaybackParams(@NonNull PlaybackParams params);
  
      /**
       * Gets the playback params, containing the current playback rate.
       *
       * @return the playback params.
       * @throws IllegalStateException if the internal player engine has not been initialized.
       */
      @NonNull
      public native PlaybackParams getPlaybackParams();
  
      /**
       * Sets A/V sync mode.
       *
       * @param params the A/V sync params to apply
       * @return a token which can be used to cancel the operation later with {@link #cancelCommand}.
       */
      // This is an asynchronous call.
      public @NonNull Object setSyncParams(@NonNull SyncParams params) {
          return addTask(new Task(CALL_COMPLETED_SET_SYNC_PARAMS, false) {
              @Override
              void process() {
                  Media2Utils.checkArgument(params != null, "the SyncParams cannot be null");
                  native_setSyncParams(params);
              }
          });
      }
  
      private native void native_setSyncParams(@NonNull SyncParams params);
  
      /**
       * Gets the A/V sync mode.
       *
       * @return the A/V sync params
       * @throws IllegalStateException if the internal player engine has not been initialized.
       */
      @NonNull
      public native SyncParams getSyncParams();
  
      /**
       * Moves the media to specified time position.
       * Same as {@link #seekTo(long, int)} with {@code mode = SEEK_PREVIOUS_SYNC}.
       *
       * @param msec the offset in milliseconds from the start to seek to
       * @return a token which can be used to cancel the operation later with {@link #cancelCommand}.
       */
      // This is an asynchronous call.
      public @NonNull Object seekTo(long msec) {
          return seekTo(msec, SEEK_PREVIOUS_SYNC /* mode */);
      }
  
      /**
       * Seek modes used in method seekTo(long, int) to move media position
       * to a specified location.
       *
       * Do not change these mode values without updating their counterparts
       * in include/media/IMediaSource.h!
       */
      /**
       * This mode is used with {@link #seekTo(long, int)} to move media position to
       * a sync (or key) frame associated with a data source that is located
       * right before or at the given time.
       *
       * @see #seekTo(long, int)
       */
      public static final int SEEK_PREVIOUS_SYNC    = 0x00;
      /**
       * This mode is used with {@link #seekTo(long, int)} to move media position to
       * a sync (or key) frame associated with a data source that is located
       * right after or at the given time.
       *
       * @see #seekTo(long, int)
       */
      public static final int SEEK_NEXT_SYNC        = 0x01;
      /**
       * This mode is used with {@link #seekTo(long, int)} to move media position to
       * a sync (or key) frame associated with a data source that is located
       * closest to (in time) or at the given time.
       *
       * @see #seekTo(long, int)
       */
      public static final int SEEK_CLOSEST_SYNC     = 0x02;
      /**
       * This mode is used with {@link #seekTo(long, int)} to move media position to
       * a frame (not necessarily a key frame) associated with a data source that
       * is located closest to or at the given time.
       *
       * @see #seekTo(long, int)
       */
      public static final int SEEK_CLOSEST          = 0x03;
  
      /** @hide */
      @IntDef(flag = false, prefix = "SEEK", value = {
              SEEK_PREVIOUS_SYNC,
              SEEK_NEXT_SYNC,
              SEEK_CLOSEST_SYNC,
              SEEK_CLOSEST,
      })
      @Retention(RetentionPolicy.SOURCE)
      public @interface SeekMode {}
  
      /**
       * Moves the media to specified time position by considering the given mode.
       * <p>
       * When seekTo is finished, the user will be notified via
       * {@link EventCallback#onCallCompleted} with {@link #CALL_COMPLETED_SEEK_TO}.
       * There is at most one active seekTo processed at any time. If there is a to-be-completed
       * seekTo, new seekTo requests will be queued in such a way that only the last request
       * is kept. When current seekTo is completed, the queued request will be processed if
       * that request is different from just-finished seekTo operation, i.e., the requested
       * position or mode is different.
       *
       * @param msec the offset in milliseconds from the start to seek to.
       * When seeking to the given time position, there is no guarantee that the data source
       * has a frame located at the position. When this happens, a frame nearby will be rendered.
       * If msec is negative, time position zero will be used.
       * If msec is larger than duration, duration will be used.
       * @param mode the mode indicating where exactly to seek to.
       * @return a token which can be used to cancel the operation later with {@link #cancelCommand}.
       */
      // This is an asynchronous call.
      public @NonNull Object seekTo(long msec, @SeekMode int mode) {
          return addTask(new Task(CALL_COMPLETED_SEEK_TO, true) {
              @Override
              void process() {
                  if (mode < SEEK_PREVIOUS_SYNC || mode > SEEK_CLOSEST) {
                      final String msg = "Illegal seek mode: " + mode;
                      throw new IllegalArgumentException(msg);
                  }
                  // TODO: pass long to native, instead of truncating here.
                  long posMs = msec;
                  if (posMs > Integer.MAX_VALUE) {
                      Log.w(TAG, "seekTo offset " + posMs + " is too large, cap to "
                              + Integer.MAX_VALUE);
                      posMs = Integer.MAX_VALUE;
                  } else if (posMs < Integer.MIN_VALUE) {
                      Log.w(TAG, "seekTo offset " + posMs + " is too small, cap to "
                              + Integer.MIN_VALUE);
                      posMs = Integer.MIN_VALUE;
                  }
  
                  synchronized (mTaskLock) {
                      if (mIsPreviousCommandSeekTo
                              && mPreviousSeekPos == posMs
                              && mPreviousSeekMode == mode) {
                          throw new CommandSkippedException(
                                  "same as previous seekTo");
                      }
                  }
  
                  native_seekTo(posMs, mode);
  
                  synchronized (mTaskLock) {
                      mIsPreviousCommandSeekTo = true;
                      mPreviousSeekPos = posMs;
                      mPreviousSeekMode = mode;
                  }
              }
          });
      }
  
      private native void native_seekTo(long msec, int mode);
  
      /**
       * Get current playback position as a {@link MediaTimestamp}.
       * <p>
       * The MediaTimestamp represents how the media time correlates to the system time in
       * a linear fashion using an anchor and a clock rate. During regular playback, the media
       * time moves fairly constantly (though the anchor frame may be rebased to a current
       * system time, the linear correlation stays steady). Therefore, this method does not
       * need to be called often.
       * <p>
       * To help users get current playback position, this method always anchors the timestamp
       * to the current {@link System#nanoTime system time}, so
       * {@link MediaTimestamp#getAnchorMediaTimeUs} can be used as current playback position.
       *
       * @return a MediaTimestamp object if a timestamp is available, or {@code null} if no timestamp
       *         is available, e.g. because the media player has not been initialized.
       *
       * @see MediaTimestamp
       */
      @Nullable
      public MediaTimestamp getTimestamp() {
          try {
              // TODO: get the timestamp from native side
              return new MediaTimestamp(
                      getCurrentPosition() * 1000L,
                      System.nanoTime(),
                      getState() == PLAYER_STATE_PLAYING ? getPlaybackParams().getSpeed() : 0.f);
          } catch (IllegalStateException e) {
              return null;
          }
      }
  
      /**
       * Checks whether the MediaPlayer2 is looping or non-looping.
       *
       * @return true if the MediaPlayer2 is currently looping, false otherwise
       */
      // This is a synchronous call.
      public native boolean isLooping();
  
      /**
       * Sets the audio session ID.
       *
       * @param sessionId the audio session ID.
       * The audio session ID is a system wide unique identifier for the audio stream played by
       * this MediaPlayer2 instance.
       * The primary use of the audio session ID  is to associate audio effects to a particular
       * instance of MediaPlayer2: if an audio session ID is provided when creating an audio effect,
       * this effect will be applied only to the audio content of media players within the same
       * audio session and not to the output mix.
       * When created, a MediaPlayer2 instance automatically generates its own audio session ID.
       * However, it is possible to force this player to be part of an already existing audio session
       * by calling this method.
       * This method must be called when player is in {@link #PLAYER_STATE_IDLE} or
       * {@link #PLAYER_STATE_PREPARED} state in order to have sessionId take effect.
       * @return a token which can be used to cancel the operation later with {@link #cancelCommand}.
       */
      // This is an asynchronous call.
      public @NonNull Object setAudioSessionId(int sessionId) {
          final AudioTrack dummyAudioTrack = new AudioTrack(AudioManager.STREAM_MUSIC, 44100,
                      AudioFormat.CHANNEL_OUT_MONO, AudioFormat.ENCODING_PCM_16BIT, 2,
                      AudioTrack.MODE_STATIC, sessionId);
          return addTask(new Task(CALL_COMPLETED_SET_AUDIO_SESSION_ID, false) {
              @Override
              void process() {
                  keepAudioSessionIdAlive(dummyAudioTrack);
                  native_setAudioSessionId(sessionId);
              }
          });
      }
  
      private native void native_setAudioSessionId(int sessionId);
  
      /**
       * Returns the audio session ID.
       *
       * @return the audio session ID. {@see #setAudioSessionId(int)}
       * Note that the audio session ID is 0 only if a problem occured when the MediaPlayer2 was
       * contructed.
       */
      // This is a synchronous call.
      public native int getAudioSessionId();
  
      /**
       * Attaches an auxiliary effect to the player. A typical auxiliary effect is a reverberation
       * effect which can be applied on any sound source that directs a certain amount of its
       * energy to this effect. This amount is defined by setAuxEffectSendLevel().
       * See {@link #setAuxEffectSendLevel(float)}.
       * <p>After creating an auxiliary effect (e.g.
       * {@link android.media.audiofx.EnvironmentalReverb}), retrieve its ID with
       * {@link android.media.audiofx.AudioEffect#getId()} and use it when calling this method
       * to attach the player to the effect.
       * <p>To detach the effect from the player, call this method with a null effect id.
       * <p>This method must be called after one of the overloaded <code> setDataSource </code>
       * methods.
       * @param effectId system wide unique id of the effect to attach
       * @return a token which can be used to cancel the operation later with {@link #cancelCommand}.
       */
      // This is an asynchronous call.
      public @NonNull Object attachAuxEffect(int effectId) {
          return addTask(new Task(CALL_COMPLETED_ATTACH_AUX_EFFECT, false) {
              @Override
              void process() {
                  native_attachAuxEffect(effectId);
              }
          });
      }
  
      private native void native_attachAuxEffect(int effectId);
  
      /**
       * Sets the send level of the player to the attached auxiliary effect.
       * See {@link #attachAuxEffect(int)}. The level value range is 0 to 1.0.
       * <p>By default the send level is 0, so even if an effect is attached to the player
       * this method must be called for the effect to be applied.
       * <p>Note that the passed level value is a raw scalar. UI controls should be scaled
       * logarithmically: the gain applied by audio framework ranges from -72dB to 0dB,
       * so an appropriate conversion from linear UI input x to level is:
       * x == 0 -> level = 0
       * 0 < x <= R -> level = 10^(72*(x-R)/20/R)
       * @param level send level scalar
       * @return a token which can be used to cancel the operation later with {@link #cancelCommand}.
       */
      // This is an asynchronous call.
      public @NonNull Object setAuxEffectSendLevel(float level) {
          return addTask(new Task(CALL_COMPLETED_SET_AUX_EFFECT_SEND_LEVEL, false) {
              @Override
              void process() {
                  native_setAuxEffectSendLevel(level);
              }
          });
      }
  
      private native void native_setAuxEffectSendLevel(float level);
  
      private static native void native_stream_event_onTearDown(
              long nativeCallbackPtr, long userDataPtr);
      private static native void native_stream_event_onStreamPresentationEnd(
              long nativeCallbackPtr, long userDataPtr);
      private static native void native_stream_event_onStreamDataRequest(
              long jAudioTrackPtr, long nativeCallbackPtr, long userDataPtr);
  
      /* Do not change these values (starting with INVOKE_ID) without updating
       * their counterparts in include/media/mediaplayer2.h!
       */
      private static final int INVOKE_ID_GET_TRACK_INFO = 1;
      private static final int INVOKE_ID_ADD_EXTERNAL_SOURCE = 2;
      private static final int INVOKE_ID_ADD_EXTERNAL_SOURCE_FD = 3;
      private static final int INVOKE_ID_SELECT_TRACK = 4;
      private static final int INVOKE_ID_DESELECT_TRACK = 5;
      private static final int INVOKE_ID_GET_SELECTED_TRACK = 7;
  
      /**
       * Invoke a generic method on the native player using opaque protocol
       * buffer message for the request and reply. Both payloads' format is a
       * convention between the java caller and the native player.
       *
       * @param msg PlayerMessage for the extension.
       *
       * @return PlayerMessage with the data returned by the
       * native player.
       */
      private PlayerMessage invoke(PlayerMessage msg) {
          byte[] ret = native_invoke(msg.toByteArray());
          if (ret == null) {
              return null;
          }
          try {
              return PlayerMessage.parseFrom(ret);
          } catch (InvalidProtocolBufferException e) {
              return null;
          }
      }
  
      private native byte[] native_invoke(byte[] request);
  
      /**
       * @hide
       */
      @IntDef(flag = false, prefix = "MEDIA_TRACK_TYPE", value = {
              TrackInfo.MEDIA_TRACK_TYPE_VIDEO,
              TrackInfo.MEDIA_TRACK_TYPE_AUDIO,
              TrackInfo.MEDIA_TRACK_TYPE_SUBTITLE
      })
      @Retention(RetentionPolicy.SOURCE)
      public @interface TrackType {}
  
      /**
       * Class for MediaPlayer2 to return each audio/video/subtitle track's metadata.
       *
       * @see MediaPlayer2#getTrackInfo
       */
      public static class TrackInfo {
          /**
           * Gets the track type.
           * @return TrackType which indicates if the track is video, audio, timed text.
           */
          public int getTrackType() {
              return mTrackType;
          }
  
          /**
           * Gets the language code of the track.
           * @return a language code in either way of ISO-639-1 or ISO-639-2.
           * When the language is unknown or could not be determined,
           * ISO-639-2 language code, "und", is returned.
           */
          public @NonNull String getLanguage() {
              String language = mFormat.getString(MediaFormat.KEY_LANGUAGE);
              return language == null ? "und" : language;
          }
  
          /**
           * Gets the {@link MediaFormat} of the track.  If the format is
           * unknown or could not be determined, null is returned.
           */
          public @Nullable MediaFormat getFormat() {
              if (mTrackType == MEDIA_TRACK_TYPE_TIMEDTEXT
                      || mTrackType == MEDIA_TRACK_TYPE_SUBTITLE) {
                  return mFormat;
              }
              return null;
          }
  
          public static final int MEDIA_TRACK_TYPE_UNKNOWN = 0;
          public static final int MEDIA_TRACK_TYPE_VIDEO = 1;
          public static final int MEDIA_TRACK_TYPE_AUDIO = 2;
  
          /** @hide */
          public static final int MEDIA_TRACK_TYPE_TIMEDTEXT = 3;
  
          public static final int MEDIA_TRACK_TYPE_SUBTITLE = 4;
          public static final int MEDIA_TRACK_TYPE_METADATA = 5;
  
          final int mId;
          final int mTrackType;
          final MediaFormat mFormat;
  
          static TrackInfo create(int idx, Iterator<Value> in) {
              int trackType = in.next().getInt32Value();
              // TODO: build the full MediaFormat; currently we are using createSubtitleFormat
              // even for audio/video tracks, meaning we only set the mime and language.
              String mime = in.next().getStringValue();
              String language = in.next().getStringValue();
              MediaFormat format = MediaFormat.createSubtitleFormat(mime, language);
  
              if (trackType == MEDIA_TRACK_TYPE_SUBTITLE) {
                  format.setInteger(MediaFormat.KEY_IS_AUTOSELECT, in.next().getInt32Value());
                  format.setInteger(MediaFormat.KEY_IS_DEFAULT, in.next().getInt32Value());
                  format.setInteger(MediaFormat.KEY_IS_FORCED_SUBTITLE, in.next().getInt32Value());
              }
              return new TrackInfo(idx, trackType, format);
          }
  
          /** @hide */
          TrackInfo(int id, int type, MediaFormat format) {
              mId = id;
              mTrackType = type;
              mFormat = format;
          }
  
          @Override
          public String toString() {
              StringBuilder out = new StringBuilder(128);
              out.append(getClass().getName());
              out.append('{');
              switch (mTrackType) {
                  case MEDIA_TRACK_TYPE_VIDEO:
                      out.append("VIDEO");
                      break;
                  case MEDIA_TRACK_TYPE_AUDIO:
                      out.append("AUDIO");
                      break;
                  case MEDIA_TRACK_TYPE_TIMEDTEXT:
                      out.append("TIMEDTEXT");
                      break;
                  case MEDIA_TRACK_TYPE_SUBTITLE:
                      out.append("SUBTITLE");
                      break;
                  default:
                      out.append("UNKNOWN");
                      break;
              }
              out.append(", " + mFormat.toString());
              out.append("}");
              return out.toString();
          }
      };
  
      /**
       * Returns a List of track information of current data source.
       * Same as {@link #getTrackInfo(DataSourceDesc)} with
       * {@code dsd = getCurrentDataSource()}.
       *
       * @return List of track info. The total number of tracks is the array length.
       * Must be called again if an external timed text source has been added after
       * addTimedTextSource method is called.
       * @throws IllegalStateException if it is called in an invalid state.
       * @throws NullPointerException if current data source is null
       */
      public @NonNull List<TrackInfo> getTrackInfo() {
          return getTrackInfo(getCurrentDataSource());
      }
  
      /**
       * Returns a List of track information.
       *
       * @param dsd the descriptor of data source of which you want to get track info
       * @return List of track info. The total number of tracks is the array length.
       * Must be called again if an external timed text source has been added after
       * addTimedTextSource method is called.
       * @throws IllegalStateException if it is called in an invalid state.
       * @throws NullPointerException if dsd is null
       */
      public @NonNull List<TrackInfo> getTrackInfo(@NonNull DataSourceDesc dsd) {
          if (dsd == null) {
              throw new NullPointerException("non-null dsd is expected");
          }
          SourceInfo sourceInfo = getSourceInfo(dsd);
          if (sourceInfo == null) {
              return new ArrayList<TrackInfo>(0);
          }
  
          TrackInfo[] trackInfo = getInbandTrackInfo(sourceInfo);
          return (trackInfo != null ? Arrays.asList(trackInfo) : new ArrayList<TrackInfo>(0));
      }
  
      private TrackInfo[] getInbandTrackInfo(SourceInfo sourceInfo) throws IllegalStateException {
          PlayerMessage request = PlayerMessage.newBuilder()
                  .addValues(Value.newBuilder().setInt32Value(INVOKE_ID_GET_TRACK_INFO))
                  .addValues(Value.newBuilder().setInt64Value(sourceInfo.mId))
                  .build();
          PlayerMessage response = invoke(request);
          if (response == null) {
              return null;
          }
          Iterator<Value> in = response.getValuesList().iterator();
          int size = in.next().getInt32Value();
          if (size == 0) {
              return null;
          }
          TrackInfo[] trackInfo = new TrackInfo[size];
          for (int i = 0; i < size; ++i) {
              trackInfo[i] = TrackInfo.create(i, in);
          }
          return trackInfo;
      }
  
      /**
       * Returns the index of the audio, video, or subtitle track currently selected for playback.
       * The return value is an index into the array returned by {@link #getTrackInfo}, and can
       * be used in calls to {@link #selectTrack(TrackInfo)} or {@link #deselectTrack(TrackInfo)}.
       * Same as {@link #getSelectedTrack(DataSourceDesc, int)} with
       * {@code dsd = getCurrentDataSource()}.
       *
       * @param trackType should be one of {@link TrackInfo#MEDIA_TRACK_TYPE_VIDEO},
       * {@link TrackInfo#MEDIA_TRACK_TYPE_AUDIO}, or
       * {@link TrackInfo#MEDIA_TRACK_TYPE_SUBTITLE}
       * @return metadata corresponding to the audio, video, or subtitle track currently selected for
       * playback; {@code null} is returned when there is no selected track for {@code trackType} or
       * when {@code trackType} is not one of audio, video, or subtitle.
       * @throws IllegalStateException if called after {@link #close()}
       * @throws NullPointerException if current data source is null
       *
       * @see #getTrackInfo()
       * @see #selectTrack(TrackInfo)
       * @see #deselectTrack(TrackInfo)
       */
      @Nullable
      public TrackInfo getSelectedTrack(@TrackType int trackType) {
          return getSelectedTrack(getCurrentDataSource(), trackType);
      }
  
      /**
       * Returns the index of the audio, video, or subtitle track currently selected for playback.
       * The return value is an index into the array returned by {@link #getTrackInfo}, and can
       * be used in calls to {@link #selectTrack(DataSourceDesc, TrackInfo)} or
       * {@link #deselectTrack(DataSourceDesc, TrackInfo)}.
       *
       * @param dsd the descriptor of data source of which you want to get selected track
       * @param trackType should be one of {@link TrackInfo#MEDIA_TRACK_TYPE_VIDEO},
       * {@link TrackInfo#MEDIA_TRACK_TYPE_AUDIO}, or
       * {@link TrackInfo#MEDIA_TRACK_TYPE_SUBTITLE}
       * @return metadata corresponding to the audio, video, or subtitle track currently selected for
       * playback; {@code null} is returned when there is no selected track for {@code trackType} or
       * when {@code trackType} is not one of audio, video, or subtitle.
       * @throws IllegalStateException if called after {@link #close()}
       * @throws NullPointerException if dsd is null
       *
       * @see #getTrackInfo(DataSourceDesc)
       * @see #selectTrack(DataSourceDesc, TrackInfo)
       * @see #deselectTrack(DataSourceDesc, TrackInfo)
       */
      @Nullable
      public TrackInfo getSelectedTrack(@NonNull DataSourceDesc dsd, @TrackType int trackType) {
          if (dsd == null) {
              throw new NullPointerException("non-null dsd is expected");
          }
          SourceInfo sourceInfo = getSourceInfo(dsd);
          if (sourceInfo == null) {
              return null;
          }
  
          PlayerMessage request = PlayerMessage.newBuilder()
                  .addValues(Value.newBuilder().setInt32Value(INVOKE_ID_GET_SELECTED_TRACK))
                  .addValues(Value.newBuilder().setInt64Value(sourceInfo.mId))
                  .addValues(Value.newBuilder().setInt32Value(trackType))
                  .build();
          PlayerMessage response = invoke(request);
          if (response == null) {
              return null;
          }
          // TODO: return full TrackInfo data from native player instead of index
          final int idx = response.getValues(0).getInt32Value();
          final List<TrackInfo> trackInfos = getTrackInfo(dsd);
          return trackInfos.isEmpty() ? null : trackInfos.get(idx);
      }
  
      /**
       * Selects a track of current data source.
       * Same as {@link #selectTrack(DataSourceDesc, TrackInfo)} with
       * {@code dsd = getCurrentDataSource()}.
       *
       * @param trackInfo metadata corresponding to the track to be selected. A {@code trackInfo}
       * object can be obtained from {@link #getTrackInfo()}.
       * @return a token which can be used to cancel the operation later with {@link #cancelCommand}.
       *
       * This is an asynchronous call.
       *
       * @see MediaPlayer2#getTrackInfo()
       */
      @NonNull
      public Object selectTrack(@NonNull TrackInfo trackInfo) {
          return selectTrack(getCurrentDataSource(), trackInfo);
      }
  
      /**
       * Selects a track.
       * <p>
       * If a MediaPlayer2 is in invalid state, it throws an IllegalStateException exception.
       * If a MediaPlayer2 is in <em>Started</em> state, the selected track is presented immediately.
       * If a MediaPlayer2 is not in Started state, it just marks the track to be played.
       * </p>
       * <p>
       * In any valid state, if it is called multiple times on the same type of track (ie. Video,
       * Audio, Timed Text), the most recent one will be chosen.
       * </p>
       * <p>
       * The first audio and video tracks are selected by default if available, even though
       * this method is not called. However, no timed text track will be selected until
       * this function is called.
       * </p>
       * <p>
       * Currently, only timed text tracks or audio tracks can be selected via this method.
       * In addition, the support for selecting an audio track at runtime is pretty limited
       * in that an audio track can only be selected in the <em>Prepared</em> state.
       * </p>
       * @param dsd the descriptor of data source of which you want to select track
       * @param trackInfo metadata corresponding to the track to be selected. A {@code trackInfo}
       * object can be obtained from {@link #getTrackInfo()}.
       * @return a token which can be used to cancel the operation later with {@link #cancelCommand}.
       *
       * This is an asynchronous call.
       *
       * @see MediaPlayer2#getTrackInfo(DataSourceDesc)
       */
      @NonNull
      public Object selectTrack(@NonNull DataSourceDesc dsd, @NonNull TrackInfo trackInfo) {
          return addTask(new Task(CALL_COMPLETED_SELECT_TRACK, false) {
              @Override
              void process() {
                  selectOrDeselectTrack(dsd, trackInfo.mId, true /* select */);
              }
          });
      }
  
      /**
       * Deselect a track of current data source.
       * Same as {@link #deselectTrack(DataSourceDesc, TrackInfo)} with
       * {@code dsd = getCurrentDataSource()}.
       *
       * @param trackInfo metadata corresponding to the track to be selected. A {@code trackInfo}
       * object can be obtained from {@link #getTrackInfo()}.
       * @return a token which can be used to cancel the operation later with {@link #cancelCommand}.
       *
       * This is an asynchronous call.
       *
       * @see MediaPlayer2#getTrackInfo()
       */
      @NonNull
      public Object deselectTrack(@NonNull TrackInfo trackInfo) {
          return deselectTrack(getCurrentDataSource(), trackInfo);
      }
  
      /**
       * Deselect a track.
       * <p>
       * Currently, the track must be a timed text track and no audio or video tracks can be
       * deselected. If the timed text track identified by index has not been
       * selected before, it throws an exception.
       * </p>
       * @param dsd the descriptor of data source of which you want to deselect track
       * @param trackInfo metadata corresponding to the track to be selected. A {@code trackInfo}
       * object can be obtained from {@link #getTrackInfo()}.
       * @return a token which can be used to cancel the operation later with {@link #cancelCommand}.
       *
       * This is an asynchronous call.
       *
       * @see MediaPlayer2#getTrackInfo(DataSourceDesc)
       */
      @NonNull
      public Object deselectTrack(@NonNull DataSourceDesc dsd, @NonNull TrackInfo trackInfo) {
          return addTask(new Task(CALL_COMPLETED_DESELECT_TRACK, false) {
              @Override
              void process() {
                  selectOrDeselectTrack(dsd, trackInfo.mId, false /* select */);
              }
          });
      }
  
      private void selectOrDeselectTrack(@NonNull DataSourceDesc dsd, int index, boolean select) {
          if (dsd == null) {
              throw new IllegalArgumentException("non-null dsd is expected");
          }
          SourceInfo sourceInfo = getSourceInfo(dsd);
          if (sourceInfo == null) {
              return;
          }
  
          PlayerMessage request = PlayerMessage.newBuilder()
                  .addValues(Value.newBuilder().setInt32Value(
                              select ? INVOKE_ID_SELECT_TRACK : INVOKE_ID_DESELECT_TRACK))
                  .addValues(Value.newBuilder().setInt64Value(sourceInfo.mId))
                  .addValues(Value.newBuilder().setInt32Value(index))
                  .build();
          invoke(request);
      }
  
      /* Do not change these values without updating their counterparts
       * in include/media/mediaplayer2.h!
       */
      private static final int MEDIA_NOP = 0; // interface test message
      private static final int MEDIA_PREPARED = 1;
      private static final int MEDIA_PLAYBACK_COMPLETE = 2;
      private static final int MEDIA_BUFFERING_UPDATE = 3;
      private static final int MEDIA_SEEK_COMPLETE = 4;
      private static final int MEDIA_SET_VIDEO_SIZE = 5;
      private static final int MEDIA_STARTED = 6;
      private static final int MEDIA_PAUSED = 7;
      private static final int MEDIA_STOPPED = 8;
      private static final int MEDIA_SKIPPED = 9;
      private static final int MEDIA_DRM_PREPARED = 10;
      private static final int MEDIA_NOTIFY_TIME = 98;
      private static final int MEDIA_TIMED_TEXT = 99;
      private static final int MEDIA_ERROR = 100;
      private static final int MEDIA_INFO = 200;
      private static final int MEDIA_SUBTITLE_DATA = 201;
      private static final int MEDIA_META_DATA = 202;
      private static final int MEDIA_DRM_INFO = 210;
  
      private class TaskHandler extends Handler {
          private MediaPlayer2 mMediaPlayer;
  
          TaskHandler(MediaPlayer2 mp, Looper looper) {
              super(looper);
              mMediaPlayer = mp;
          }
  
          @Override
          public void handleMessage(Message msg) {
              handleMessage(msg, 0);
          }
  
          public void handleMessage(Message msg, long srcId) {
              if (mMediaPlayer.mNativeContext == 0) {
                  Log.w(TAG, "mediaplayer2 went away with unhandled events");
                  return;
              }
              final int what = msg.arg1;
              final int extra = msg.arg2;
  
              final SourceInfo sourceInfo = getSourceInfo(srcId);
              if (sourceInfo == null) {
                  return;
              }
              final DataSourceDesc dsd = sourceInfo.mDSD;
  
              switch(msg.what) {
                  case MEDIA_PREPARED:
                  case MEDIA_DRM_PREPARED:
                  {
                      sourceInfo.mPrepareBarrier--;
                      if (sourceInfo.mPrepareBarrier > 0) {
                          break;
                      } else if (sourceInfo.mPrepareBarrier < 0) {
                          Log.w(TAG, "duplicated (drm) prepared events");
                          break;
                      }
  
                      if (dsd != null) {
                          sendEvent(new EventNotifier() {
                              @Override
                              public void notify(EventCallback callback) {
                                  callback.onInfo(
                                          mMediaPlayer, dsd, MEDIA_INFO_PREPARED, 0);
                              }
                          });
                      }
  
                      synchronized (mSrcLock) {
                          SourceInfo nextSourceInfo = mNextSourceInfos.peek();
                          Log.i(TAG, "MEDIA_PREPARED: srcId=" + srcId
                                  + ", curSrc=" + mCurrentSourceInfo
                                  + ", nextSrc=" + nextSourceInfo);
  
                          if (isCurrentSource(srcId)) {
                              prepareNextDataSource();
                          } else if (isNextSource(srcId)) {
                              nextSourceInfo.mStateAsNextSource = NEXT_SOURCE_STATE_PREPARED;
                              if (nextSourceInfo.mPlayPendingAsNextSource) {
                                  playNextDataSource();
                              }
                          }
                      }
  
                      synchronized (mTaskLock) {
                          if (mCurrentTask != null
                                  && mCurrentTask.mMediaCallType == CALL_COMPLETED_PREPARE
                                  && mCurrentTask.mDSD == dsd
                                  && mCurrentTask.mNeedToWaitForEventToComplete) {
                              mCurrentTask.sendCompleteNotification(CALL_STATUS_NO_ERROR);
                              mCurrentTask = null;
                              processPendingTask_l();
                          }
                      }
                      return;
                  }
  
                  case MEDIA_DRM_INFO:
                  {
                      if (msg.obj == null) {
                          Log.w(TAG, "MEDIA_DRM_INFO msg.obj=NULL");
                      } else if (msg.obj instanceof byte[]) {
                          // The PlayerMessage was parsed already in postEventFromNative
  
                          final DrmInfo drmInfo;
                          synchronized (sourceInfo) {
                              if (sourceInfo.mDrmInfo != null) {
                                  drmInfo = sourceInfo.mDrmInfo.makeCopy();
                              } else {
                                  drmInfo = null;
                              }
                          }
  
                          // notifying the client outside the lock
                          DrmPreparationInfo drmPrepareInfo = null;
                          if (drmInfo != null) {
                              try {
                                  drmPrepareInfo = sendDrmEventWait(
                                          new DrmEventNotifier<DrmPreparationInfo>() {
                                              @Override
                                              public DrmPreparationInfo notifyWait(
                                                      DrmEventCallback callback) {
                                                  return callback.onDrmInfo(mMediaPlayer, dsd,
                                                          drmInfo);
                                              }
                                          });
                              } catch (InterruptedException | ExecutionException
                                      | TimeoutException e) {
                                  Log.w(TAG, "Exception while waiting for DrmPreparationInfo", e);
                              }
                          }
                          if (sourceInfo.mDrmHandle.setPreparationInfo(drmPrepareInfo)) {
                              sourceInfo.mPrepareBarrier++;
                              final Task prepareDrmTask;
                              prepareDrmTask = newPrepareDrmTask(dsd, drmPrepareInfo.mUUID);
                              mTaskHandler.post(new Runnable() {
                                  @Override
                                  public void run() {
                                      // Run as simple Runnable, not Task
                                      try {
                                          prepareDrmTask.process();
                                      } catch (NoDrmSchemeException | IOException e) {
                                          final String errMsg;
                                          errMsg = "Unexpected Exception during prepareDrm";
                                          throw new RuntimeException(errMsg, e);
                                      }
                                  }
                              });
                          } else {
                              Log.w(TAG, "No valid DrmPreparationInfo set");
                          }
                      } else {
                          Log.w(TAG, "MEDIA_DRM_INFO msg.obj of unexpected type " + msg.obj);
                      }
                      return;
                  }
  
                  case MEDIA_PLAYBACK_COMPLETE:
                  {
                      if (isCurrentSource(srcId)) {
                          sendEvent(new EventNotifier() {
                              @Override
                              public void notify(EventCallback callback) {
                                  callback.onInfo(
                                          mMediaPlayer, dsd, MEDIA_INFO_DATA_SOURCE_END, 0);
                              }
                          });
                          stayAwake(false);
  
                          synchronized (mSrcLock) {
                              SourceInfo nextSourceInfo = mNextSourceInfos.peek();
                              if (nextSourceInfo != null) {
                                  nextSourceInfo.mPlayPendingAsNextSource = true;
                              }
                              Log.i(TAG, "MEDIA_PLAYBACK_COMPLETE: srcId=" + srcId
                                      + ", curSrc=" + mCurrentSourceInfo
                                      + ", nextSrc=" + nextSourceInfo);
                          }
  
                          playNextDataSource();
                      }
  
                      return;
                  }
  
                  case MEDIA_STOPPED:
                  case MEDIA_STARTED:
                  case MEDIA_PAUSED:
                  case MEDIA_SKIPPED:
                  case MEDIA_NOTIFY_TIME:
                  {
                      // Do nothing. The client should have enough information with
                      // {@link EventCallback#onMediaTimeDiscontinuity}.
                      break;
                  }
  
                  case MEDIA_BUFFERING_UPDATE:
                  {
                      final int percent = msg.arg1;
                      sendEvent(new EventNotifier() {
                          @Override
                          public void notify(EventCallback callback) {
                              callback.onInfo(
                                      mMediaPlayer, dsd, MEDIA_INFO_BUFFERING_UPDATE, percent);
                          }
                      });
  
                      SourceInfo src = getSourceInfo(srcId);
                      if (src != null) {
                          src.mBufferedPercentage.set(percent);
                      }
  
                      return;
                  }
  
                  case MEDIA_SEEK_COMPLETE:
                  {
                      synchronized (mTaskLock) {
                          if (!mPendingTasks.isEmpty()
                                  && mPendingTasks.get(0).mMediaCallType != CALL_COMPLETED_SEEK_TO
                                  && getState() == PLAYER_STATE_PLAYING) {
                              mIsPreviousCommandSeekTo = false;
                          }
  
                          if (mCurrentTask != null
                                  && mCurrentTask.mMediaCallType == CALL_COMPLETED_SEEK_TO
                                  && mCurrentTask.mNeedToWaitForEventToComplete) {
                              mCurrentTask.sendCompleteNotification(CALL_STATUS_NO_ERROR);
                              mCurrentTask = null;
                              processPendingTask_l();
                          }
                      }
                      return;
                  }
  
                  case MEDIA_SET_VIDEO_SIZE:
                  {
                      final int width = msg.arg1;
                      final int height = msg.arg2;
  
                      mVideoSize = new Size(width, height);
                      sendEvent(new EventNotifier() {
                          @Override
                          public void notify(EventCallback callback) {
                              callback.onVideoSizeChanged(
                                      mMediaPlayer, dsd, mVideoSize);
                          }
                      });
                      return;
                  }
  
                  case MEDIA_ERROR:
                  {
                      Log.e(TAG, "Error (" + msg.arg1 + "," + msg.arg2 + ")");
                      sendEvent(new EventNotifier() {
                          @Override
                          public void notify(EventCallback callback) {
                              callback.onError(
                                      mMediaPlayer, dsd, what, extra);
                          }
                      });
                      sendEvent(new EventNotifier() {
                          @Override
                          public void notify(EventCallback callback) {
                              callback.onInfo(
                                      mMediaPlayer, dsd, MEDIA_INFO_DATA_SOURCE_END, 0);
                          }
                      });
                      stayAwake(false);
                      return;
                  }
  
                  case MEDIA_INFO:
                  {
                      switch (msg.arg1) {
                          case MEDIA_INFO_VIDEO_TRACK_LAGGING:
                              Log.i(TAG, "Info (" + msg.arg1 + "," + msg.arg2 + ")");
                              break;
                      }
  
                      sendEvent(new EventNotifier() {
                          @Override
                          public void notify(EventCallback callback) {
                              callback.onInfo(
                                      mMediaPlayer, dsd, what, extra);
                          }
                      });
  
                      if (msg.arg1 == MEDIA_INFO_DATA_SOURCE_START) {
                          if (isCurrentSource(srcId)) {
                              prepareNextDataSource();
                          }
                      }
  
                      // No real default action so far.
                      return;
                  }
  
                  case MEDIA_TIMED_TEXT:
                  {
                      final TimedText text;
                      if (msg.obj instanceof byte[]) {
                          PlayerMessage playerMsg;
                          try {
                              playerMsg = PlayerMessage.parseFrom((byte[]) msg.obj);
                          } catch (InvalidProtocolBufferException e) {
                              Log.w(TAG, "Failed to parse timed text.", e);
                              return;
                          }
                          text = TimedTextUtil.parsePlayerMessage(playerMsg);
                      } else {
                          text = null;
                      }
  
                      sendEvent(new EventNotifier() {
                          @Override
                          public void notify(EventCallback callback) {
                              callback.onTimedText(
                                      mMediaPlayer, dsd, text);
                          }
                      });
                      return;
                  }
  
                  case MEDIA_SUBTITLE_DATA:
                  {
                      if (msg.obj instanceof byte[]) {
                          PlayerMessage playerMsg;
                          try {
                              playerMsg = PlayerMessage.parseFrom((byte[]) msg.obj);
                          } catch (InvalidProtocolBufferException e) {
                              Log.w(TAG, "Failed to parse subtitle data.", e);
                              return;
                          }
                          Iterator<Value> in = playerMsg.getValuesList().iterator();
                          final int trackIndex = in.next().getInt32Value();
                          TrackInfo trackInfo = getTrackInfo(dsd).get(trackIndex);
                          final long startTimeUs = in.next().getInt64Value();
                          final long durationTimeUs = in.next().getInt64Value();
                          final byte[] subData = in.next().getBytesValue().toByteArray();
                          SubtitleData data = new SubtitleData(trackInfo,
                                  startTimeUs, durationTimeUs, subData);
                          sendEvent(new EventNotifier() {
                              @Override
                              public void notify(EventCallback callback) {
                                  callback.onSubtitleData(
                                          mMediaPlayer, dsd, data);
                              }
                          });
                      }
                      return;
                  }
  
                  case MEDIA_META_DATA:
                  {
                      final TimedMetaData data;
                      if (msg.obj instanceof byte[]) {
                          PlayerMessage playerMsg;
                          try {
                              playerMsg = PlayerMessage.parseFrom((byte[]) msg.obj);
                          } catch (InvalidProtocolBufferException e) {
                              Log.w(TAG, "Failed to parse timed meta data.", e);
                              return;
                          }
                          Iterator<Value> in = playerMsg.getValuesList().iterator();
                          data = new TimedMetaData(
                                  in.next().getInt64Value(),  // timestampUs
                                  in.next().getBytesValue().toByteArray());  // metaData
                      } else {
                          data = null;
                      }
  
                      sendEvent(new EventNotifier() {
                          @Override
                          public void notify(EventCallback callback) {
                              callback.onTimedMetaDataAvailable(
                                      mMediaPlayer, dsd, data);
                          }
                      });
                      return;
                  }
  
                  case MEDIA_NOP: // interface test message - ignore
                  {
                      break;
                  }
  
                  default:
                  {
                      Log.e(TAG, "Unknown message type " + msg.what);
                      return;
                  }
              }
          }
      }
  
      /*
       * Called from native code when an interesting event happens.  This method
       * just uses the TaskHandler system to post the event back to the main app thread.
       * We use a weak reference to the original MediaPlayer2 object so that the native
       * code is safe from the object disappearing from underneath it.  (This is
       * the cookie passed to native_setup().)
       */
      private static void postEventFromNative(Object mediaplayer2Ref, long srcId,
                                              int what, int arg1, int arg2, byte[] obj) {
          final MediaPlayer2 mp = (MediaPlayer2) ((WeakReference) mediaplayer2Ref).get();
          if (mp == null) {
              return;
          }
  
          final SourceInfo sourceInfo = mp.getSourceInfo(srcId);
          switch (what) {
              case MEDIA_DRM_INFO:
                  // We need to derive mDrmInfo before prepare() returns so processing it here
                  // before the notification is sent to TaskHandler below. TaskHandler runs in the
                  // notification looper so its handleMessage might process the event after prepare()
                  // has returned.
                  Log.v(TAG, "postEventFromNative MEDIA_DRM_INFO");
                  if (obj != null && sourceInfo != null) {
                      PlayerMessage playerMsg;
                      try {
                          playerMsg = PlayerMessage.parseFrom(obj);
                      } catch (InvalidProtocolBufferException e) {
                          Log.w(TAG, "MEDIA_DRM_INFO failed to parse msg.obj " + obj);
                          break;
                      }
                      DrmInfo drmInfo = DrmInfo.create(playerMsg);
                      synchronized (sourceInfo) {
                          sourceInfo.mDrmInfo = drmInfo;
                      }
                  } else {
                      Log.w(TAG, "MEDIA_DRM_INFO sourceInfo " + sourceInfo
                              + " msg.obj of unexpected type " + obj);
                  }
                  break;
  
              case MEDIA_PREPARED:
                  // By this time, we've learned about DrmInfo's presence or absence. This is meant
                  // mainly for prepare() use case. For prepare(), this still can run to a race
                  // condition b/c MediaPlayerNative releases the prepare() lock before calling notify
                  // so we also set mDrmInfoResolved in prepare().
                  if (sourceInfo != null) {
                      synchronized (sourceInfo) {
                          sourceInfo.mDrmInfoResolved = true;
                      }
                  }
                  break;
          }
  
          if (mp.mTaskHandler != null) {
              Message m = mp.mTaskHandler.obtainMessage(what, arg1, arg2, obj);
  
              mp.mTaskHandler.post(new Runnable() {
                  @Override
                  public void run() {
                      mp.mTaskHandler.handleMessage(m, srcId);
                  }
              });
          }
      }
  
      /**
       * Class encapsulating subtitle data, as received through the
       * {@link EventCallback#onSubtitleData} interface.
       * <p>
       * A {@link SubtitleData} object includes:
       * <ul>
       * <li> track metadadta in a {@link TrackInfo} object</li>
       * <li> the start time (in microseconds) of the data</li>
       * <li> the duration (in microseconds) of the data</li>
       * <li> the actual data.</li>
       * </ul>
       * The data is stored in a byte-array, and is encoded in one of the supported in-band
       * subtitle formats. The subtitle encoding is determined by the MIME type of the
       * {@link TrackInfo} of the subtitle track, one of
       * {@link MediaFormat#MIMETYPE_TEXT_CEA_608}, {@link MediaFormat#MIMETYPE_TEXT_CEA_708},
       * {@link MediaFormat#MIMETYPE_TEXT_VTT}.
       */
      public static final class SubtitleData {
  
          private TrackInfo mTrackInfo;
          private long mStartTimeUs;
          private long mDurationUs;
          private byte[] mData;
  
          private SubtitleData(TrackInfo trackInfo, long startTimeUs, long durationUs, byte[] data) {
              mTrackInfo = trackInfo;
              mStartTimeUs = startTimeUs;
              mDurationUs = durationUs;
              mData = (data != null ? data : new byte[0]);
          }
  
          /**
           * @return metadata of track which contains this subtitle data
           */
          @NonNull
          public TrackInfo getTrackInfo() {
              return mTrackInfo;
          }
  
          /**
           * @return media time at which the subtitle should start to be displayed in microseconds
           */
          public long getStartTimeUs() {
              return mStartTimeUs;
          }
  
          /**
           * @return the duration in microsecond during which the subtitle should be displayed
           */
          public long getDurationUs() {
              return mDurationUs;
          }
  
          /**
           * Returns the encoded data for the subtitle content.
           * Encoding format depends on the subtitle type, refer to
           * <a href="https://en.wikipedia.org/wiki/CEA-708">CEA 708</a>,
           * <a href="https://en.wikipedia.org/wiki/EIA-608">CEA/EIA 608</a> and
           * <a href="https://www.w3.org/TR/webvtt1/">WebVTT</a>, defined by the MIME type
           * of the subtitle track.
           * @return the encoded subtitle data
           */
          @NonNull
          public byte[] getData() {
              return mData;
          }
      }
  
      /**
       * Interface definition for callbacks to be invoked when the player has the corresponding
       * events.
       */
      public static class EventCallback {
          /**
           * Called to indicate the video size
           *
           * The video size (width and height) could be 0 if there was no video,
           * or the value was not determined yet.
           *
           * @param mp the MediaPlayer2 associated with this callback
           * @param dsd the DataSourceDesc of this data source
           * @param size the size of the video
           */
          public void onVideoSizeChanged(
                  @NonNull MediaPlayer2 mp, @NonNull DataSourceDesc dsd, @NonNull Size size) { }
  
          /**
           * Called to indicate an avaliable timed text
           *
           * @param mp the MediaPlayer2 associated with this callback
           * @param dsd the DataSourceDesc of this data source
           * @param text the timed text sample which contains the text
           *             needed to be displayed and the display format.
           * @hide
           */
          public void onTimedText(
                  @NonNull MediaPlayer2 mp, @NonNull DataSourceDesc dsd, @NonNull TimedText text) { }
  
          /**
           * Called to indicate avaliable timed metadata
           * <p>
           * This method will be called as timed metadata is extracted from the media,
           * in the same order as it occurs in the media. The timing of this event is
           * not controlled by the associated timestamp.
           * <p>
           * Currently only HTTP live streaming data URI's embedded with timed ID3 tags generates
           * {@link TimedMetaData}.
           *
           * @see MediaPlayer2#selectTrack
           * @see MediaPlayer2.OnTimedMetaDataAvailableListener
           * @see TimedMetaData
           *
           * @param mp the MediaPlayer2 associated with this callback
           * @param dsd the DataSourceDesc of this data source
           * @param data the timed metadata sample associated with this event
           */
          public void onTimedMetaDataAvailable(
                  @NonNull MediaPlayer2 mp, @NonNull DataSourceDesc dsd,
                  @NonNull TimedMetaData data) { }
  
          /**
           * Called to indicate an error.
           *
           * @param mp the MediaPlayer2 the error pertains to
           * @param dsd the DataSourceDesc of this data source
           * @param what the type of error that has occurred.
           * @param extra an extra code, specific to the error. Typically
           * implementation dependent.
           */
          public void onError(
                  @NonNull MediaPlayer2 mp, @NonNull DataSourceDesc dsd,
                  @MediaError int what, int extra) { }
  
          /**
           * Called to indicate an info or a warning.
           *
           * @param mp the MediaPlayer2 the info pertains to.
           * @param dsd the DataSourceDesc of this data source
           * @param what the type of info or warning.
           * @param extra an extra code, specific to the info. Typically
           * implementation dependent.
           */
          public void onInfo(
                  @NonNull MediaPlayer2 mp, @NonNull DataSourceDesc dsd,
                  @MediaInfo int what, int extra) { }
  
          /**
           * Called to acknowledge an API call.
           *
           * @param mp the MediaPlayer2 the call was made on.
           * @param dsd the DataSourceDesc of this data source
           * @param what the enum for the API call.
           * @param status the returned status code for the call.
           */
          public void onCallCompleted(
                  @NonNull MediaPlayer2 mp, @NonNull DataSourceDesc dsd, @CallCompleted int what,
                  @CallStatus int status) { }
  
          /**
           * Called to indicate media clock has changed.
           *
           * @param mp the MediaPlayer2 the media time pertains to.
           * @param dsd the DataSourceDesc of this data source
           * @param timestamp the new media clock.
           */
          public void onMediaTimeDiscontinuity(
                  @NonNull MediaPlayer2 mp, @NonNull DataSourceDesc dsd,
                  @NonNull MediaTimestamp timestamp) { }
  
          /**
           * Called to indicate {@link #notifyWhenCommandLabelReached(Object)} has been processed.
           *
           * @param mp the MediaPlayer2 {@link #notifyWhenCommandLabelReached(Object)} was called on.
           * @param label the application specific Object given by
           *        {@link #notifyWhenCommandLabelReached(Object)}.
           */
          public void onCommandLabelReached(@NonNull MediaPlayer2 mp, @NonNull Object label) { }
  
          /**
           * Called when when a player subtitle track has new subtitle data available.
           * @param mp the player that reports the new subtitle data
           * @param dsd the DataSourceDesc of this data source
           * @param data the subtitle data
           */
          public void onSubtitleData(
                  @NonNull MediaPlayer2 mp, @NonNull DataSourceDesc dsd,
                  @NonNull SubtitleData data) { }
      }
  
      private final Object mEventCbLock = new Object();
      private ArrayList<Pair<Executor, EventCallback>> mEventCallbackRecords =
              new ArrayList<Pair<Executor, EventCallback>>();
  
      /**
       * Registers the callback to be invoked for various events covered by {@link EventCallback}.
       *
       * @param executor the executor through which the callback should be invoked
       * @param eventCallback the callback that will be run
       */
      // This is a synchronous call.
      public void registerEventCallback(@NonNull @CallbackExecutor Executor executor,
              @NonNull EventCallback eventCallback) {
          if (eventCallback == null) {
              throw new IllegalArgumentException("Illegal null EventCallback");
          }
          if (executor == null) {
              throw new IllegalArgumentException(
                      "Illegal null Executor for the EventCallback");
          }
          synchronized (mEventCbLock) {
              for (Pair<Executor, EventCallback> cb : mEventCallbackRecords) {
                  if (cb.first == executor && cb.second == eventCallback) {
                      Log.w(TAG, "The callback has been registered before.");
                      return;
                  }
              }
              mEventCallbackRecords.add(new Pair(executor, eventCallback));
          }
      }
  
      /**
       * Unregisters the {@link EventCallback}.
       *
       * @param eventCallback the callback to be unregistered
       */
      // This is a synchronous call.
      public void unregisterEventCallback(@NonNull EventCallback eventCallback) {
          synchronized (mEventCbLock) {
              for (Pair<Executor, EventCallback> cb : mEventCallbackRecords) {
                  if (cb.second == eventCallback) {
                      mEventCallbackRecords.remove(cb);
                  }
              }
          }
      }
  
      private void sendEvent(final EventNotifier notifier) {
          synchronized (mEventCbLock) {
              try {
                  for (Pair<Executor, EventCallback> cb : mEventCallbackRecords) {
                      cb.first.execute(() -> notifier.notify(cb.second));
                  }
              } catch (RejectedExecutionException e) {
                  // The executor has been shut down.
                  Log.w(TAG, "The executor has been shut down. Ignoring event.");
              }
          }
      }
  
      private void sendDrmEvent(final DrmEventNotifier notifier) {
          synchronized (mDrmEventCallbackLock) {
              try {
                  Pair<Executor, DrmEventCallback> cb = mDrmEventCallback;
                  if (cb != null) {
                      cb.first.execute(() -> notifier.notify(cb.second));
                  }
              } catch (RejectedExecutionException e) {
                  // The executor has been shut down.
                  Log.w(TAG, "The executor has been shut down. Ignoring drm event.");
              }
          }
      }
  
      private <T> T sendDrmEventWait(final DrmEventNotifier<T> notifier)
              throws InterruptedException, ExecutionException, TimeoutException {
          return sendDrmEventWait(notifier, 0);
      }
  
      private <T> T sendDrmEventWait(final DrmEventNotifier<T> notifier, final long timeoutMs)
              throws InterruptedException, ExecutionException, TimeoutException {
          synchronized (mDrmEventCallbackLock) {
              Pair<Executor, DrmEventCallback> cb = mDrmEventCallback;
              if (cb != null) {
                  CompletableFuture<T> ret = new CompletableFuture<>();
                  cb.first.execute(() -> ret.complete(notifier.notifyWait(cb.second)));
                  return timeoutMs <= 0 ? ret.get() : ret.get(timeoutMs, TimeUnit.MILLISECONDS);
              }
          }
          return null;
      }
  
      private interface EventNotifier {
          void notify(EventCallback callback);
      }
  
      private interface DrmEventNotifier<T> {
          default void notify(DrmEventCallback callback) { }
          default T notifyWait(DrmEventCallback callback) {
              return null;
          }
      }
  
      /* Do not change these values without updating their counterparts
       * in include/media/MediaPlayer2Types.h!
       */
      /** Unspecified media player error.
       * @see EventCallback#onError
       */
      public static final int MEDIA_ERROR_UNKNOWN = 1;
  
      /**
       * The video is streamed and its container is not valid for progressive
       * playback i.e the video's index (e.g moov atom) is not at the start of the
       * file.
       * @see EventCallback#onError
       */
      public static final int MEDIA_ERROR_NOT_VALID_FOR_PROGRESSIVE_PLAYBACK = 200;
  
      /** File or network related operation errors. */
      public static final int MEDIA_ERROR_IO = -1004;
      /** Bitstream is not conforming to the related coding standard or file spec. */
      public static final int MEDIA_ERROR_MALFORMED = -1007;
      /** Bitstream is conforming to the related coding standard or file spec, but
       * the media framework does not support the feature. */
      public static final int MEDIA_ERROR_UNSUPPORTED = -1010;
      /** Some operation takes too long to complete, usually more than 3-5 seconds. */
      public static final int MEDIA_ERROR_TIMED_OUT = -110;
  
      /** Unspecified low-level system error. This value originated from UNKNOWN_ERROR in
       * system/core/include/utils/Errors.h
       * @see EventCallback#onError
       * @hide
       */
      public static final int MEDIA_ERROR_SYSTEM = -2147483648;
  
      /**
       * @hide
       */
      @IntDef(flag = false, prefix = "MEDIA_ERROR", value = {
              MEDIA_ERROR_UNKNOWN,
              MEDIA_ERROR_NOT_VALID_FOR_PROGRESSIVE_PLAYBACK,
              MEDIA_ERROR_IO,
              MEDIA_ERROR_MALFORMED,
              MEDIA_ERROR_UNSUPPORTED,
              MEDIA_ERROR_TIMED_OUT,
              MEDIA_ERROR_SYSTEM
      })
      @Retention(RetentionPolicy.SOURCE)
      public @interface MediaError {}
  
      /* Do not change these values without updating their counterparts
       * in include/media/MediaPlayer2Types.h!
       */
      /** Unspecified media player info.
       * @see EventCallback#onInfo
       */
      public static final int MEDIA_INFO_UNKNOWN = 1;
  
      /** The player just started the playback of this datas source.
       * @see EventCallback#onInfo
       */
      public static final int MEDIA_INFO_DATA_SOURCE_START = 2;
  
      /** The player just pushed the very first video frame for rendering.
       * @see EventCallback#onInfo
       */
      public static final int MEDIA_INFO_VIDEO_RENDERING_START = 3;
  
      /** The player just rendered the very first audio sample.
       * @see EventCallback#onInfo
       */
      public static final int MEDIA_INFO_AUDIO_RENDERING_START = 4;
  
      /** The player just completed the playback of this data source.
       * @see EventCallback#onInfo
       */
      public static final int MEDIA_INFO_DATA_SOURCE_END = 5;
  
      /** The player just completed the playback of all data sources set by {@link #setDataSource},
       * {@link #setNextDataSource} and {@link #setNextDataSources}.
       * @see EventCallback#onInfo
       */
      public static final int MEDIA_INFO_DATA_SOURCE_LIST_END = 6;
  
      /** The player just completed an iteration of playback loop. This event is sent only when
       *  looping is enabled by {@link #loopCurrent}.
       * @see EventCallback#onInfo
       */
      public static final int MEDIA_INFO_DATA_SOURCE_REPEAT = 7;
  
      /** The player just prepared a data source.
       * @see EventCallback#onInfo
       */
      public static final int MEDIA_INFO_PREPARED = 100;
  
      /** The video is too complex for the decoder: it can't decode frames fast
       *  enough. Possibly only the audio plays fine at this stage.
       * @see EventCallback#onInfo
       */
      public static final int MEDIA_INFO_VIDEO_TRACK_LAGGING = 700;
  
      /** MediaPlayer2 is temporarily pausing playback internally in order to
       * buffer more data.
       * @see EventCallback#onInfo
       */
      public static final int MEDIA_INFO_BUFFERING_START = 701;
  
      /** MediaPlayer2 is resuming playback after filling buffers.
       * @see EventCallback#onInfo
       */
      public static final int MEDIA_INFO_BUFFERING_END = 702;
  
      /** Estimated network bandwidth information (kbps) is available; currently this event fires
       * simultaneously as {@link #MEDIA_INFO_BUFFERING_START} and {@link #MEDIA_INFO_BUFFERING_END}
       * when playing network files.
       * @see EventCallback#onInfo
       * @hide
       */
      public static final int MEDIA_INFO_NETWORK_BANDWIDTH = 703;
  
      /**
       * Update status in buffering a media source received through progressive downloading.
       * The received buffering percentage indicates how much of the content has been buffered
       * or played. For example a buffering update of 80 percent when half the content
       * has already been played indicates that the next 30 percent of the
       * content to play has been buffered.
       *
       * The {@code extra} parameter in {@code EventCallback.onInfo} is the
       * percentage (0-100) of the content that has been buffered or played thus far.
       * @see EventCallback#onInfo
       */
      public static final int MEDIA_INFO_BUFFERING_UPDATE = 704;
  
      /** Bad interleaving means that a media has been improperly interleaved or
       * not interleaved at all, e.g has all the video samples first then all the
       * audio ones. Video is playing but a lot of disk seeks may be happening.
       * @see EventCallback#onInfo
       */
      public static final int MEDIA_INFO_BAD_INTERLEAVING = 800;
  
      /** The media cannot be seeked (e.g live stream)
       * @see EventCallback#onInfo
       */
      public static final int MEDIA_INFO_NOT_SEEKABLE = 801;
  
      /** A new set of metadata is available.
       * @see EventCallback#onInfo
       */
      public static final int MEDIA_INFO_METADATA_UPDATE = 802;
  
      /** Informs that audio is not playing. Note that playback of the video
       * is not interrupted.
       * @see EventCallback#onInfo
       */
      public static final int MEDIA_INFO_AUDIO_NOT_PLAYING = 804;
  
      /** Informs that video is not playing. Note that playback of the audio
       * is not interrupted.
       * @see EventCallback#onInfo
       */
      public static final int MEDIA_INFO_VIDEO_NOT_PLAYING = 805;
  
      /** Failed to handle timed text track properly.
       * @see EventCallback#onInfo
       *
       * {@hide}
       */
      public static final int MEDIA_INFO_TIMED_TEXT_ERROR = 900;
  
      /** Subtitle track was not supported by the media framework.
       * @see EventCallback#onInfo
       */
      public static final int MEDIA_INFO_UNSUPPORTED_SUBTITLE = 901;
  
      /** Reading the subtitle track takes too long.
       * @see EventCallback#onInfo
       */
      public static final int MEDIA_INFO_SUBTITLE_TIMED_OUT = 902;
  
      /**
       * @hide
       */
      @IntDef(flag = false, prefix = "MEDIA_INFO", value = {
              MEDIA_INFO_UNKNOWN,
              MEDIA_INFO_DATA_SOURCE_START,
              MEDIA_INFO_VIDEO_RENDERING_START,
              MEDIA_INFO_AUDIO_RENDERING_START,
              MEDIA_INFO_DATA_SOURCE_END,
              MEDIA_INFO_DATA_SOURCE_LIST_END,
              MEDIA_INFO_PREPARED,
              MEDIA_INFO_VIDEO_TRACK_LAGGING,
              MEDIA_INFO_BUFFERING_START,
              MEDIA_INFO_BUFFERING_END,
              MEDIA_INFO_NETWORK_BANDWIDTH,
              MEDIA_INFO_BUFFERING_UPDATE,
              MEDIA_INFO_BAD_INTERLEAVING,
              MEDIA_INFO_NOT_SEEKABLE,
              MEDIA_INFO_METADATA_UPDATE,
              MEDIA_INFO_AUDIO_NOT_PLAYING,
              MEDIA_INFO_VIDEO_NOT_PLAYING,
              MEDIA_INFO_TIMED_TEXT_ERROR,
              MEDIA_INFO_UNSUPPORTED_SUBTITLE,
              MEDIA_INFO_SUBTITLE_TIMED_OUT
      })
      @Retention(RetentionPolicy.SOURCE)
      public @interface MediaInfo {}
  
      //--------------------------------------------------------------------------
      /** The player just completed a call {@link #attachAuxEffect}.
       * @see EventCallback#onCallCompleted
       */
      public static final int CALL_COMPLETED_ATTACH_AUX_EFFECT = 1;
  
      /** The player just completed a call {@link #deselectTrack}.
       * @see EventCallback#onCallCompleted
       */
      public static final int CALL_COMPLETED_DESELECT_TRACK = 2;
  
      /** The player just completed a call {@link #loopCurrent}.
       * @see EventCallback#onCallCompleted
       */
      public static final int CALL_COMPLETED_LOOP_CURRENT = 3;
  
      /** The player just completed a call {@link #pause}.
       * @see EventCallback#onCallCompleted
       */
      public static final int CALL_COMPLETED_PAUSE = 4;
  
      /** The player just completed a call {@link #play}.
       * @see EventCallback#onCallCompleted
       */
      public static final int CALL_COMPLETED_PLAY = 5;
  
      /** The player just completed a call {@link #prepare}.
       * @see EventCallback#onCallCompleted
       */
      public static final int CALL_COMPLETED_PREPARE = 6;
  
      /** The player just completed a call {@link #seekTo}.
       * @see EventCallback#onCallCompleted
       */
      public static final int CALL_COMPLETED_SEEK_TO = 14;
  
      /** The player just completed a call {@link #selectTrack}.
       * @see EventCallback#onCallCompleted
       */
      public static final int CALL_COMPLETED_SELECT_TRACK = 15;
  
      /** The player just completed a call {@link #setAudioAttributes}.
       * @see EventCallback#onCallCompleted
       */
      public static final int CALL_COMPLETED_SET_AUDIO_ATTRIBUTES = 16;
  
      /** The player just completed a call {@link #setAudioSessionId}.
       * @see EventCallback#onCallCompleted
       */
      public static final int CALL_COMPLETED_SET_AUDIO_SESSION_ID = 17;
  
      /** The player just completed a call {@link #setAuxEffectSendLevel}.
       * @see EventCallback#onCallCompleted
       */
      public static final int CALL_COMPLETED_SET_AUX_EFFECT_SEND_LEVEL = 18;
  
      /** The player just completed a call {@link #setDataSource}.
       * @see EventCallback#onCallCompleted
       */
      public static final int CALL_COMPLETED_SET_DATA_SOURCE = 19;
  
      /** The player just completed a call {@link #setNextDataSource}.
       * @see EventCallback#onCallCompleted
       */
      public static final int CALL_COMPLETED_SET_NEXT_DATA_SOURCE = 22;
  
      /** The player just completed a call {@link #setNextDataSources}.
       * @see EventCallback#onCallCompleted
       */
      public static final int CALL_COMPLETED_SET_NEXT_DATA_SOURCES = 23;
  
      /** The player just completed a call {@link #setPlaybackParams}.
       * @see EventCallback#onCallCompleted
       */
      public static final int CALL_COMPLETED_SET_PLAYBACK_PARAMS = 24;
  
      /** The player just completed a call {@link #setPlayerVolume}.
       * @see EventCallback#onCallCompleted
       */
      public static final int CALL_COMPLETED_SET_PLAYER_VOLUME = 26;
  
      /** The player just completed a call {@link #setSurface}.
       * @see EventCallback#onCallCompleted
       */
      public static final int CALL_COMPLETED_SET_SURFACE = 27;
  
      /** The player just completed a call {@link #setSyncParams}.
       * @see EventCallback#onCallCompleted
       */
      public static final int CALL_COMPLETED_SET_SYNC_PARAMS = 28;
  
      /** The player just completed a call {@link #skipToNext}.
       * @see EventCallback#onCallCompleted
       */
      public static final int CALL_COMPLETED_SKIP_TO_NEXT = 29;
  
      /** The player just completed a call {@link #clearNextDataSources}.
       * @see EventCallback#onCallCompleted
       */
      public static final int CALL_COMPLETED_CLEAR_NEXT_DATA_SOURCES = 30;
  
      /** The player just completed a call {@link #setBufferingParams}.
       * @see EventCallback#onCallCompleted
       * @hide
       */
      public static final int CALL_COMPLETED_SET_BUFFERING_PARAMS = 31;
  
      /** The player just completed a call {@link #setDisplay}.
       * @see EventCallback#onCallCompleted
       */
      public static final int CALL_COMPLETED_SET_DISPLAY = 33;
  
      /** The player just completed a call {@link #setWakeLock}.
       * @see EventCallback#onCallCompleted
       */
      public static final int CALL_COMPLETED_SET_WAKE_LOCK = 34;
  
      /** The player just completed a call {@link #setScreenOnWhilePlaying}.
       * @see EventCallback#onCallCompleted
       */
      public static final int CALL_COMPLETED_SET_SCREEN_ON_WHILE_PLAYING = 35;
  
      /**
       * The start of the methods which have separate call complete callback.
       * @hide
       */
      public static final int SEPARATE_CALL_COMPLETED_CALLBACK_START = 1000;
  
      /** The player just completed a call {@link #notifyWhenCommandLabelReached}.
       * @see EventCallback#onCommandLabelReached
       * @hide
       */
      public static final int CALL_COMPLETED_NOTIFY_WHEN_COMMAND_LABEL_REACHED =
              SEPARATE_CALL_COMPLETED_CALLBACK_START;
  
      /** The player just completed a call {@link #prepareDrm}.
       * @see DrmEventCallback#onDrmPrepared
       * @hide
       */
      public static final int CALL_COMPLETED_PREPARE_DRM =
              SEPARATE_CALL_COMPLETED_CALLBACK_START + 1;
  
      /**
       * @hide
       */
      @IntDef(flag = false, prefix = "CALL_COMPLETED", value = {
              CALL_COMPLETED_ATTACH_AUX_EFFECT,
              CALL_COMPLETED_DESELECT_TRACK,
              CALL_COMPLETED_LOOP_CURRENT,
              CALL_COMPLETED_PAUSE,
              CALL_COMPLETED_PLAY,
              CALL_COMPLETED_PREPARE,
              CALL_COMPLETED_SEEK_TO,
              CALL_COMPLETED_SELECT_TRACK,
              CALL_COMPLETED_SET_AUDIO_ATTRIBUTES,
              CALL_COMPLETED_SET_AUDIO_SESSION_ID,
              CALL_COMPLETED_SET_AUX_EFFECT_SEND_LEVEL,
              CALL_COMPLETED_SET_DATA_SOURCE,
              CALL_COMPLETED_SET_NEXT_DATA_SOURCE,
              CALL_COMPLETED_SET_NEXT_DATA_SOURCES,
              CALL_COMPLETED_SET_PLAYBACK_PARAMS,
              CALL_COMPLETED_SET_PLAYER_VOLUME,
              CALL_COMPLETED_SET_SURFACE,
              CALL_COMPLETED_SET_SYNC_PARAMS,
              CALL_COMPLETED_SKIP_TO_NEXT,
              CALL_COMPLETED_CLEAR_NEXT_DATA_SOURCES,
              CALL_COMPLETED_SET_BUFFERING_PARAMS,
              CALL_COMPLETED_SET_DISPLAY,
              CALL_COMPLETED_SET_WAKE_LOCK,
              CALL_COMPLETED_SET_SCREEN_ON_WHILE_PLAYING,
              CALL_COMPLETED_NOTIFY_WHEN_COMMAND_LABEL_REACHED,
              CALL_COMPLETED_PREPARE_DRM,
      })
      @Retention(RetentionPolicy.SOURCE)
      public @interface CallCompleted {}
  
      /** Status code represents that call is completed without an error.
       * @see EventCallback#onCallCompleted
       */
      public static final int CALL_STATUS_NO_ERROR = 0;
  
      /** Status code represents that call is ended with an unknown error.
       * @see EventCallback#onCallCompleted
       */
      public static final int CALL_STATUS_ERROR_UNKNOWN = Integer.MIN_VALUE;
  
      /** Status code represents that the player is not in valid state for the operation.
       * @see EventCallback#onCallCompleted
       */
      public static final int CALL_STATUS_INVALID_OPERATION = 1;
  
      /** Status code represents that the argument is illegal.
       * @see EventCallback#onCallCompleted
       */
      public static final int CALL_STATUS_BAD_VALUE = 2;
  
      /** Status code represents that the operation is not allowed.
       * @see EventCallback#onCallCompleted
       */
      public static final int CALL_STATUS_PERMISSION_DENIED = 3;
  
      /** Status code represents a file or network related operation error.
       * @see EventCallback#onCallCompleted
       */
      public static final int CALL_STATUS_ERROR_IO = 4;
  
      /** Status code represents that the call has been skipped. For example, a {@link #seekTo}
       * request may be skipped if it is followed by another {@link #seekTo} request.
       * @see EventCallback#onCallCompleted
       */
      public static final int CALL_STATUS_SKIPPED = 5;
  
      /** Status code represents that DRM operation is called before preparing a DRM scheme through
       *  {@code prepareDrm}.
       * @see EventCallback#onCallCompleted
       */
      // TODO: change @code to @link when DRM is unhidden
      public static final int CALL_STATUS_NO_DRM_SCHEME = 6;
  
      /**
       * @hide
       */
      @IntDef(flag = false, prefix = "CALL_STATUS", value = {
              CALL_STATUS_NO_ERROR,
              CALL_STATUS_ERROR_UNKNOWN,
              CALL_STATUS_INVALID_OPERATION,
              CALL_STATUS_BAD_VALUE,
              CALL_STATUS_PERMISSION_DENIED,
              CALL_STATUS_ERROR_IO,
              CALL_STATUS_SKIPPED,
              CALL_STATUS_NO_DRM_SCHEME})
      @Retention(RetentionPolicy.SOURCE)
      public @interface CallStatus {}
  
      // Modular DRM begin
  
      /**
       * An immutable structure per {@link DataSourceDesc} with settings required to initiate a DRM
       * protected playback session.
       *
       * @see DrmPreparationInfo.Builder
       */
      public static final class DrmPreparationInfo {
  
          /**
           * Mutable builder to create a {@link MediaPlayer2.DrmPreparationInfo} object.
           *
           * {@link Builder#Builder(UUID) UUID} must not be null; {@link #setKeyType keyType}
           * must be one of {@link MediaDrm#KEY_TYPE_STREAMING} or {@link MediaDrm#KEY_TYPE_OFFLINE}.
           * <p>
           * When {@link #setKeyType keyType} is {@link MediaDrm#KEY_TYPE_STREAMING},
           * {@link #setInitData(byte[]) initData} and {@link #setMimeType(String) mimeType}
           * must not be null; When {@link #setKeyType keyType} is {@link MediaDrm#KEY_TYPE_OFFLINE},
           * {@link #setKeySetId(byte[]) keySetId} must not be null.
           */
          public static final class Builder {
  
              private final UUID mUUID;
              private byte[] mKeySetId;
              private byte[] mInitData;
              private String mMimeType;
              private int mKeyType;
              private Map<String, String> mOptionalParameters;
  
              /**
               * @param uuid UUID of the crypto scheme selected to decrypt content. An UUID can be
               * retrieved from the source listening to {@link DrmEventCallback#onDrmInfo}.
               */
              public Builder(@NonNull UUID uuid) {
                  this.mUUID = uuid;
              }
  
              /**
               * Set identifier of a persisted offline key obtained from
               * {@link MediaPlayer2.DrmEventCallback#onDrmPrepared}.
               *
               * A {@code keySetId} can be used to restore persisted offline keys into a new playback
               * session of a DRM protected data source. When {@code keySetId} is set,
               * {@code initData}, {@code mimeType}, {@code keyType}, {@code optionalParameters} are
               * ignored.
               *
               * @param keySetId identifier of a persisted offline key
               * @return this
               */
              public @NonNull Builder setKeySetId(@Nullable byte[] keySetId) {
                  this.mKeySetId = keySetId;
                  return this;
              }
  
              /**
               * Set container-specific DRM initialization data. Its meaning is interpreted based on
               * {@code mimeType}. For example, it could contain the content ID, key ID or other data
               * obtained from the content metadata that is required to generate a
               * {@link MediaDrm.KeyRequest}.
               *
               * @param initData container-specific DRM initialization data
               * @return this
               */
              public @NonNull Builder setInitData(@Nullable byte[] initData) {
                  this.mInitData = initData;
                  return this;
              }
  
              /**
               * Set mime type of the content
               *
               * @param mimeType mime type to the content
               * @return this
               */
              public @NonNull Builder setMimeType(@Nullable String mimeType) {
                  this.mMimeType = mimeType;
                  return this;
              }
  
              /**
               * Set type of the key request. The request may be to acquire keys
               * for streaming, {@link MediaDrm#KEY_TYPE_STREAMING}, or for offline content,
               * {@link MediaDrm#KEY_TYPE_OFFLINE}. Releasing previously acquired keys
               * ({@link MediaDrm#KEY_TYPE_RELEASE}) is not allowed.
               *
               * @param keyType type of the key request
               * @return this
               */
              public @NonNull Builder setKeyType(@MediaPlayer2.MediaDrmKeyType int keyType) {
                  this.mKeyType = keyType;
                  return this;
              }
  
              /**
               * Set optional parameters to be included in a {@link MediaDrm.KeyRequest} message sent
               * to the license server.
               *
               * @param optionalParameters optional parameters to be included in a key request
               * @return this
               */
              public @NonNull Builder setOptionalParameters(
                      @Nullable Map<String, String> optionalParameters) {
                  this.mOptionalParameters = optionalParameters;
                  return this;
              }
  
              /**
               * @return an immutable {@link DrmPreparationInfo} based on settings of this builder
               */
              @NonNull
              public DrmPreparationInfo build() {
                  final DrmPreparationInfo info = new DrmPreparationInfo(mUUID, mKeySetId, mInitData,
                          mMimeType, mKeyType, mOptionalParameters);
                  if (!info.isValid()) {
                      throw new IllegalArgumentException("invalid DrmPreparationInfo");
                  }
                  return info;
              }
  
          }
  
          private final UUID mUUID;
          private final byte[] mKeySetId;
          private final byte[] mInitData;
          private final String mMimeType;
          private final int mKeyType;
          private final Map<String, String> mOptionalParameters;
  
          private DrmPreparationInfo(UUID mUUID, byte[] mKeySetId, byte[] mInitData, String mMimeType,
                  int mKeyType, Map<String, String> optionalParameters) {
              this.mUUID = mUUID;
              this.mKeySetId = mKeySetId;
              this.mInitData = mInitData;
              this.mMimeType = mMimeType;
              this.mKeyType = mKeyType;
              this.mOptionalParameters = optionalParameters;
          }
  
          boolean isValid() {
              if (mUUID == null) {
                  return false;
              }
              if (mKeySetId != null) {
                  // offline restore case
                  return true;
              }
              if (mInitData != null && mMimeType != null) {
                  // new streaming license case
                  return true;
              }
              return false;
          }
  
          /**
           * @return UUID of the crypto scheme selected to decrypt content.
           */
          @NonNull
          public UUID getUuid() {
              return mUUID;
          }
  
          /**
           * @return identifier of the persisted offline key.
           */
          @Nullable
          public byte[] getKeySetId() {
              return mKeySetId;
          }
  
          /**
           * @return container-specific DRM initialization data.
           */
          @Nullable
          public byte[] getInitData() {
              return mInitData;
          }
  
          /**
           * @return mime type of the content
           */
          @Nullable
          public String getMimeType() {
              return mMimeType;
          }
  
          /**
           * @return type of the key request.
           */
          @MediaPlayer2.MediaDrmKeyType
          public int getKeyType() {
              return mKeyType;
          }
  
          /**
           * @return optional parameters to be included in the {@link MediaDrm.KeyRequest}.
           */
          @Nullable
          public Map<String, String> getOptionalParameters() {
              return mOptionalParameters;
          }
      }
  
      /**
       * Interface definition for callbacks to be invoked when the player has the corresponding
       * DRM events.
       */
      public static abstract class DrmEventCallback {
  
          /**
           * Called to indicate DRM info is available. Return a {@link DrmPreparationInfo} object that
           * bundles DRM initialization parameters.
           *
           * @param mp the {@code MediaPlayer2} associated with this callback
           * @param dsd the {@link DataSourceDesc} of this data source
           * @param drmInfo DRM info of the source including PSSH, and subset of crypto schemes
           *        supported by this device
           * @return a {@link DrmPreparationInfo} object to initialize DRM playback, or null to skip
           *         DRM initialization
           */
          @Nullable
          public abstract DrmPreparationInfo onDrmInfo(@NonNull MediaPlayer2 mp,
                  @NonNull DataSourceDesc dsd, @NonNull DrmInfo drmInfo);
  
          /**
           * Called to give the app the opportunity to configure DRM before the session is created.
           *
           * This facilitates configuration of the properties, like 'securityLevel', which
           * has to be set after DRM scheme creation but before the DRM session is opened.
           *
           * The only allowed DRM calls in this listener are
           * {@link MediaDrm#getPropertyString(String)},
           * {@link MediaDrm#getPropertyByteArray(String)},
           * {@link MediaDrm#setPropertyString(String, String)},
           * {@link MediaDrm#setPropertyByteArray(String, byte[])},
           * {@link MediaDrm#setOnExpirationUpdateListener},
           * and {@link MediaDrm#setOnKeyStatusChangeListener}.
           *
           * @param mp the {@code MediaPlayer2} associated with this callback
           * @param dsd the {@link DataSourceDesc} of this data source
           * @param drm handle to get/set DRM properties and listeners for this data source
           */
          public void onDrmConfig(@NonNull MediaPlayer2 mp, @NonNull DataSourceDesc dsd,
                  @NonNull MediaDrm drm) { }
  
          /**
           * Called to indicate the DRM session for {@code dsd} is ready for key request/response
           *
           * @param mp the {@code MediaPlayer2} associated with this callback
           * @param dsd the {@link DataSourceDesc} of this data source
           * @param request a {@link MediaDrm.KeyRequest} prepared using the
           *        {@link DrmPreparationInfo} returned from
           *        {@link #onDrmInfo(MediaPlayer2, DataSourceDesc, DrmInfo)}
           * @return the response to {@code request} (from license server); returning {@code null} or
           *         throwing an {@link RuntimeException} from this callback would trigger an
           *         {@link EventCallback#onError}.
           */
          @NonNull
          public abstract byte[] onDrmKeyRequest(@NonNull MediaPlayer2 mp,
                  @NonNull DataSourceDesc dsd, @NonNull MediaDrm.KeyRequest request);
  
          /**
           * Called to notify the client that {@code mp} is ready to decrypt DRM protected data source
           * {@code dsd} or if there is an error during DRM preparation
           *
           * @param mp the {@code MediaPlayer2} associated with this callback
           * @param dsd the {@link DataSourceDesc} of this data source
           * @param status the result of DRM preparation.
           * @param keySetId optional identifier that can be used to restore DRM playback initiated
           *        with a {@link MediaDrm#KEY_TYPE_OFFLINE} key request.
           *
           * @see DrmPreparationInfo.Builder#setKeySetId(byte[])
           */
          public void onDrmPrepared(@NonNull MediaPlayer2 mp, @NonNull DataSourceDesc dsd,
                  @PrepareDrmStatusCode int status, @Nullable byte[] keySetId) { }
  
      }
  
      private final Object mDrmEventCallbackLock = new Object();
      private Pair<Executor, DrmEventCallback> mDrmEventCallback;
  
      /**
       * Registers the callback to be invoked for various DRM events.
       *
       * This is a synchronous call.
       *
       * @param eventCallback the callback that will be run
       * @param executor the executor through which the callback should be invoked
       */
      public void setDrmEventCallback(@NonNull @CallbackExecutor Executor executor,
              @NonNull DrmEventCallback eventCallback) {
          if (eventCallback == null) {
              throw new IllegalArgumentException("Illegal null EventCallback");
          }
          if (executor == null) {
              throw new IllegalArgumentException(
                      "Illegal null Executor for the EventCallback");
          }
          synchronized (mDrmEventCallbackLock) {
              mDrmEventCallback = new Pair<Executor, DrmEventCallback>(executor, eventCallback);
          }
      }
  
      /**
       * Clear the {@link DrmEventCallback}.
       *
       * This is a synchronous call.
       */
      public void clearDrmEventCallback() {
          synchronized (mDrmEventCallbackLock) {
              mDrmEventCallback = null;
          }
      }
  
      /**
       * A status code for {@link DrmEventCallback#onDrmPrepared} listener.
       * <p>
       *
       * DRM preparation has succeeded.
       */
      public static final int PREPARE_DRM_STATUS_SUCCESS = 0;
  
      /**
       * A status code for {@link DrmEventCallback#onDrmPrepared} listener.
       * <p>
       *
       * The device required DRM provisioning but couldn't reach the provisioning server.
       */
      public static final int PREPARE_DRM_STATUS_PROVISIONING_NETWORK_ERROR = 1;
  
      /**
       * A status code for {@link DrmEventCallback#onDrmPrepared} listener.
       * <p>
       *
       * The device required DRM provisioning but the provisioning server denied the request.
       */
      public static final int PREPARE_DRM_STATUS_PROVISIONING_SERVER_ERROR = 2;
  
      /**
       * A status code for {@link DrmEventCallback#onDrmPrepared} listener.
       * <p>
       *
       * The DRM preparation has failed .
       */
      public static final int PREPARE_DRM_STATUS_PREPARATION_ERROR = 3;
  
      /**
       * A status code for {@link DrmEventCallback#onDrmPrepared} listener.
       * <p>
       *
       * The crypto scheme UUID is not supported by the device.
       */
      public static final int PREPARE_DRM_STATUS_UNSUPPORTED_SCHEME = 4;
  
      /**
       * A status code for {@link DrmEventCallback#onDrmPrepared} listener.
       * <p>
       *
       * The hardware resources are not available, due to being in use.
       */
      public static final int PREPARE_DRM_STATUS_RESOURCE_BUSY = 5;
  
      /**
       * A status code for {@link DrmEventCallback#onDrmPrepared} listener.
       * <p>
       *
       * Restoring persisted offline keys failed.
       */
      public static final int PREPARE_DRM_STATUS_RESTORE_ERROR = 6;
  
      /**
       * A status code for {@link DrmEventCallback#onDrmPrepared} listener.
       * <p>
       *
       * Error during key request/response exchange with license server.
       */
      public static final int PREPARE_DRM_STATUS_KEY_EXCHANGE_ERROR = 7;
  
      /** @hide */
      @IntDef(flag = false, prefix = "PREPARE_DRM_STATUS", value = {
          PREPARE_DRM_STATUS_SUCCESS,
          PREPARE_DRM_STATUS_PROVISIONING_NETWORK_ERROR,
          PREPARE_DRM_STATUS_PROVISIONING_SERVER_ERROR,
          PREPARE_DRM_STATUS_PREPARATION_ERROR,
          PREPARE_DRM_STATUS_UNSUPPORTED_SCHEME,
          PREPARE_DRM_STATUS_RESOURCE_BUSY,
          PREPARE_DRM_STATUS_RESTORE_ERROR,
          PREPARE_DRM_STATUS_KEY_EXCHANGE_ERROR,
      })
      @Retention(RetentionPolicy.SOURCE)
      public @interface PrepareDrmStatusCode {}
  
      /** @hide */
      @IntDef({
          MediaDrm.KEY_TYPE_STREAMING,
          MediaDrm.KEY_TYPE_OFFLINE,
          MediaDrm.KEY_TYPE_RELEASE,
      })
      @Retention(RetentionPolicy.SOURCE)
      public @interface MediaDrmKeyType {}
  
      /** @hide */
      @StringDef({
          MediaDrm.PROPERTY_VENDOR,
          MediaDrm.PROPERTY_VERSION,
          MediaDrm.PROPERTY_DESCRIPTION,
          MediaDrm.PROPERTY_ALGORITHMS,
      })
      @Retention(RetentionPolicy.SOURCE)
      public @interface MediaDrmStringProperty {}
  
      /**
       * Retrieves the DRM Info associated with the given source
       *
       * @param dsd The DRM protected data source
       *
       * @throws IllegalStateException if called before being prepared
       * @hide
       */
      @TestApi
      public DrmInfo getDrmInfo(@NonNull DataSourceDesc dsd) {
          final SourceInfo sourceInfo = getSourceInfo(dsd);
          if (sourceInfo != null) {
              DrmInfo drmInfo = null;
  
              // there is not much point if the app calls getDrmInfo within an OnDrmInfoListener;
              // regardless below returns drmInfo anyway instead of raising an exception
              synchronized (sourceInfo) {
                  if (!sourceInfo.mDrmInfoResolved && sourceInfo.mDrmInfo == null) {
                      final String msg = "The Player has not been prepared yet";
                      Log.v(TAG, msg);
                      throw new IllegalStateException(msg);
                  }
  
                  if (sourceInfo.mDrmInfo != null) {
                      drmInfo  = sourceInfo.mDrmInfo.makeCopy();
                  }
              }   // synchronized
  
              return drmInfo;
          }
          return null;
      }
  
      /**
       * Prepares the DRM for the given data source
       * <p>
       * If {@link DrmEventCallback} is registered, it will be called during
       * preparation to allow configuration of the DRM properties before opening the
       * DRM session. It should be used only for a series of
       * {@link #getDrmPropertyString(DataSourceDesc, String)} and
       * {@link #setDrmPropertyString(DataSourceDesc, String, String)} calls
       * and refrain from any lengthy operation.
       * <p>
       * If the device has not been provisioned before, this call also provisions the device
       * which involves accessing the provisioning server and can take a variable time to
       * complete depending on the network connectivity.
       * When needed, the provisioning will be launched  in the background.
       * The listener {@link DrmEventCallback#onDrmPrepared}
       * will be called when provisioning and preparation are finished. The application should
       * check the status code returned with {@link DrmEventCallback#onDrmPrepared} to proceed.
       * <p>
       * The registered {@link DrmEventCallback#onDrmPrepared} is called to indicate the DRM
       * session being ready. The application should not make any assumption about its call
       * sequence (e.g., before or after prepareDrm returns).
       * <p>
       *
       * @param dsd The DRM protected data source
       *
       * @param uuid The UUID of the crypto scheme. If not known beforehand, it can be retrieved
       * from the source listening to {@link DrmEventCallback#onDrmInfo}.
       *
       * @return a token which can be used to cancel the operation later with {@link #cancelCommand}.
       * @hide
       */
      // This is an asynchronous call.
      @TestApi
      public @NonNull Object prepareDrm(@NonNull DataSourceDesc dsd, @NonNull UUID uuid) {
          return addTask(newPrepareDrmTask(dsd, uuid));
      }
  
      private Task newPrepareDrmTask(DataSourceDesc dsd, UUID uuid) {
          return new Task(CALL_COMPLETED_PREPARE_DRM, true) {
              @Override
              void process() {
                  final SourceInfo sourceInfo = getSourceInfo(dsd);
                  int status = PREPARE_DRM_STATUS_PREPARATION_ERROR;
                  boolean finishPrepare = true;
  
                  if (sourceInfo == null) {
                      Log.e(TAG, "prepareDrm(): DataSource not found.");
                  } else if (sourceInfo.mDrmInfo == null) {
                      // only allowing if tied to a protected source;
                      // might relax for releasing offline keys
                      Log.e(TAG, "prepareDrm(): Wrong usage: The player must be prepared and "
                              + "DRM info be retrieved before this call.");
                  } else {
                      status = PREPARE_DRM_STATUS_SUCCESS;
                  }
  
                  try {
                      if (status == PREPARE_DRM_STATUS_SUCCESS) {
                          sourceInfo.mDrmHandle.prepare(uuid);
                      }
                  } catch (ResourceBusyException e) {
                      status = PREPARE_DRM_STATUS_RESOURCE_BUSY;
                  } catch (UnsupportedSchemeException e) {
                      status = PREPARE_DRM_STATUS_UNSUPPORTED_SCHEME;
                  } catch (NotProvisionedException e) {
                      Log.w(TAG, "prepareDrm: NotProvisionedException");
  
                      // handle provisioning internally; it'll reset mPrepareDrmInProgress
                      status = sourceInfo.mDrmHandle.handleProvisioninig(uuid, mTaskId);
  
                      if (status == PREPARE_DRM_STATUS_SUCCESS) {
                          // License will be setup in provisioning
                          finishPrepare = false;
                      } else {
                          synchronized (sourceInfo.mDrmHandle) {
                              sourceInfo.mDrmHandle.cleanDrmObj();
                          }
  
                          switch (status) {
                              case PREPARE_DRM_STATUS_PROVISIONING_NETWORK_ERROR:
                                  Log.e(TAG, "prepareDrm: Provisioning was required but failed "
                                          + "due to a network error.");
                                  break;
  
                              case PREPARE_DRM_STATUS_PROVISIONING_SERVER_ERROR:
                                  Log.e(TAG, "prepareDrm: Provisioning was required but the request "
                                          + "was denied by the server.");
                                  break;
  
                              case PREPARE_DRM_STATUS_PREPARATION_ERROR:
                              default:
                                  Log.e(TAG, "prepareDrm: Post-provisioning preparation failed.");
                                  break;
                          }
                      }
                  } catch (Exception e) {
                      status = PREPARE_DRM_STATUS_PREPARATION_ERROR;
                  }
  
                  if (finishPrepare) {
                      sourceInfo.mDrmHandle.finishPrepare(status);
                      synchronized (mTaskLock) {
                          mCurrentTask = null;
                          processPendingTask_l();
                      }
                  }
  
              }
          };
      }
  
      /**
       * Releases the DRM session for the given data source
       * <p>
       * The player has to have an active DRM session and be in stopped, or prepared
       * state before this call is made.
       * A {@link #reset()} call will release the DRM session implicitly.
       *
       * @param dsd The DRM protected data source
       *
       * @throws NoDrmSchemeException if there is no active DRM session to release
       * @hide
       */
      // This is a synchronous call.
      @TestApi
      public void releaseDrm(@NonNull DataSourceDesc dsd)
              throws NoDrmSchemeException {
          final SourceInfo sourceInfo = getSourceInfo(dsd);
          if (sourceInfo != null) {
              sourceInfo.mDrmHandle.release();
          }
      }
  
      private native void native_releaseDrm(long mSrcId);
  
      /**
       * A key request/response exchange occurs between the app and a license server
       * to obtain or release keys used to decrypt the given data source.
       * <p>
       * {@code getDrmKeyRequest()} is used to obtain an opaque key request byte array that is
       * delivered to the license server.  The opaque key request byte array is returned
       * in KeyRequest.data.  The recommended URL to deliver the key request to is
       * returned in {@code KeyRequest.defaultUrl}.
       * <p>
       * After the app has received the key request response from the server,
       * it should deliver to the response to the DRM engine plugin using the method
       * {@link #provideDrmKeyResponse(DataSourceDesc, byte[], byte[])}.
       *
       * @param dsd the DRM protected data source
       *
       * @param keySetId is the key-set identifier of the offline keys being released when keyType is
       * {@link MediaDrm#KEY_TYPE_RELEASE}. It should be set to null for other key requests, when
       * keyType is {@link MediaDrm#KEY_TYPE_STREAMING} or {@link MediaDrm#KEY_TYPE_OFFLINE}.
       *
       * @param initData is the container-specific initialization data when the keyType is
       * {@link MediaDrm#KEY_TYPE_STREAMING} or {@link MediaDrm#KEY_TYPE_OFFLINE}. Its meaning is
       * interpreted based on the mime type provided in the mimeType parameter.  It could
       * contain, for example, the content ID, key ID or other data obtained from the content
       * metadata that is required in generating the key request.
       * When the keyType is {@link MediaDrm#KEY_TYPE_RELEASE}, it should be set to null.
       *
       * @param mimeType identifies the mime type of the content
       *
       * @param keyType specifies the type of the request. The request may be to acquire
       * keys for streaming, {@link MediaDrm#KEY_TYPE_STREAMING}, or for offline content
       * {@link MediaDrm#KEY_TYPE_OFFLINE}, or to release previously acquired
       * keys ({@link MediaDrm#KEY_TYPE_RELEASE}), which are identified by a keySetId.
       *
       * @param optionalParameters are included in the key request message to
       * allow a client application to provide additional message parameters to the server.
       * This may be {@code null} if no additional parameters are to be sent.
       *
       * @throws NoDrmSchemeException if there is no active DRM session
       * @hide
       */
      @TestApi
      public MediaDrm.KeyRequest getDrmKeyRequest(
              @NonNull DataSourceDesc dsd,
              @Nullable byte[] keySetId, @Nullable byte[] initData,
              @Nullable String mimeType, @MediaDrmKeyType int keyType,
              @Nullable Map<String, String> optionalParameters)
              throws NoDrmSchemeException {
          Log.v(TAG, "getDrmKeyRequest: " +
                  " keySetId: " + keySetId + " initData:" + initData + " mimeType: " + mimeType +
                  " keyType: " + keyType + " optionalParameters: " + optionalParameters);
  
          final SourceInfo sourceInfo = getSourceInfo(dsd);
          if (sourceInfo != null) {
              return sourceInfo.mDrmHandle.getDrmKeyRequest(
                      keySetId, initData, mimeType, keyType, optionalParameters);
          }
          return null;
      }
  
      /**
       * A key response is received from the license server by the app for the given DRM protected
       * data source, then provided to the DRM engine plugin using {@code provideDrmKeyResponse}.
       * <p>
       * When the response is for an offline key request, a key-set identifier is returned that
       * can be used to later restore the keys to a new session with the method
       * {@link #restoreDrmKeys(DataSourceDesc, byte[])}.
       * When the response is for a streaming or release request, null is returned.
       *
       * @param dsd the DRM protected data source
       *
       * @param keySetId When the response is for a release request, keySetId identifies the saved
       * key associated with the release request (i.e., the same keySetId passed to the earlier
       * {@link # getDrmKeyRequest(DataSourceDesc, byte[], byte[], String, int, Map)} call).
       * It MUST be null when the response is for either streaming or offline key requests.
       *
       * @param response the byte array response from the server
       *
       * @throws NoDrmSchemeException if there is no active DRM session
       * @throws DeniedByServerException if the response indicates that the
       * server rejected the request
       * @hide
       */
      // This is a synchronous call.
      @TestApi
      public byte[] provideDrmKeyResponse(
              @NonNull DataSourceDesc dsd,
              @Nullable byte[] keySetId, @NonNull byte[] response)
              throws NoDrmSchemeException, DeniedByServerException {
          Log.v(TAG, "provideDrmKeyResponse: keySetId: " + keySetId + " response: " + response);
  
          final SourceInfo sourceInfo = getSourceInfo(dsd);
          if (sourceInfo != null) {
              return sourceInfo.mDrmHandle.provideDrmKeyResponse(keySetId, response);
          }
          return null;
      }
  
      /**
       * Restore persisted offline keys into a new session for the given DRM protected data source.
       * {@code keySetId} identifies the keys to load, obtained from a prior call to
       * {@link #provideDrmKeyResponse(DataSourceDesc, byte[], byte[])}.
       *
       * @param dsd the DRM protected data source
       *
       * @param keySetId identifies the saved key set to restore
       *
       * @throws NoDrmSchemeException if there is no active DRM session
       * @hide
       */
      // This is a synchronous call.
      @TestApi
      public void restoreDrmKeys(
              @NonNull DataSourceDesc dsd,
              @NonNull byte[] keySetId)
              throws NoDrmSchemeException {
          Log.v(TAG, "restoreDrmKeys: keySetId: " + keySetId);
  
          final SourceInfo sourceInfo = getSourceInfo(dsd);
          if (sourceInfo != null) {
              sourceInfo.mDrmHandle.restoreDrmKeys(keySetId);
          }
      }
  
      /**
       * Read a DRM engine plugin String property value, given the DRM protected data source
       * and property name string.
       *
       * @param dsd the DRM protected data source
       *
       * @param propertyName the property name
       *
       * Standard fields names are:
       * {@link MediaDrm#PROPERTY_VENDOR}, {@link MediaDrm#PROPERTY_VERSION},
       * {@link MediaDrm#PROPERTY_DESCRIPTION}, {@link MediaDrm#PROPERTY_ALGORITHMS}
       *
       * @throws NoDrmSchemeException if there is no active DRM session
       * @hide
       */
      @TestApi
      public String getDrmPropertyString(
              @NonNull DataSourceDesc dsd,
              @NonNull @MediaDrmStringProperty String propertyName)
              throws NoDrmSchemeException {
          Log.v(TAG, "getDrmPropertyString: propertyName: " + propertyName);
  
          final SourceInfo sourceInfo = getSourceInfo(dsd);
          if (sourceInfo != null) {
              return sourceInfo.mDrmHandle.getDrmPropertyString(propertyName);
          }
          return null;
      }
  
      /**
       * Set a DRM engine plugin String property value for the given data source.
       *
       * @param dsd the DRM protected data source
       * @param propertyName the property name
       * @param value the property value
       *
       * Standard fields names are:
       * {@link MediaDrm#PROPERTY_VENDOR}, {@link MediaDrm#PROPERTY_VERSION},
       * {@link MediaDrm#PROPERTY_DESCRIPTION}, {@link MediaDrm#PROPERTY_ALGORITHMS}
       *
       * @throws NoDrmSchemeException if there is no active DRM session
       * @hide
       */
      // This is a synchronous call.
      @TestApi
      public void setDrmPropertyString(
              @NonNull DataSourceDesc dsd,
              @NonNull @MediaDrmStringProperty String propertyName, @NonNull String value)
              throws NoDrmSchemeException {
          // TODO: this implementation only works when dsd is the only data source
          Log.v(TAG, "setDrmPropertyString: propertyName: " + propertyName + " value: " + value);
  
          final SourceInfo sourceInfo = getSourceInfo(dsd);
          if (sourceInfo != null) {
              sourceInfo.mDrmHandle.setDrmPropertyString(propertyName, value);
          }
      }
  
      /**
       * Encapsulates the DRM properties of the source.
       */
      public static final class DrmInfo {
          private Map<UUID, byte[]> mMapPssh;
          private UUID[] mSupportedSchemes;
  
          /**
           * Returns the PSSH info of the data source for each supported DRM scheme.
           */
          public @NonNull Map<UUID, byte[]> getPssh() {
              return mMapPssh;
          }
  
          /**
           * Returns the intersection of the data source and the device DRM schemes.
           * It effectively identifies the subset of the source's DRM schemes which
           * are supported by the device too.
           */
          public @NonNull List<UUID> getSupportedSchemes() {
              return Arrays.asList(mSupportedSchemes);
          }
  
          private DrmInfo(Map<UUID, byte[]> pssh, UUID[] supportedSchemes) {
              mMapPssh = pssh;
              mSupportedSchemes = supportedSchemes;
          }
  
          private static DrmInfo create(PlayerMessage msg) {
              Log.v(TAG, "DrmInfo.create(" + msg + ")");
  
              Iterator<Value> in = msg.getValuesList().iterator();
              byte[] pssh = in.next().getBytesValue().toByteArray();
  
              Log.v(TAG, "DrmInfo.create() PSSH: " + DrmInfo.arrToHex(pssh));
              Map<UUID, byte[]> mapPssh = DrmInfo.parsePSSH(pssh, pssh.length);
              Log.v(TAG, "DrmInfo.create() PSSH: " + mapPssh);
  
              int supportedDRMsCount = in.next().getInt32Value();
              UUID[] supportedSchemes = new UUID[supportedDRMsCount];
              for (int i = 0; i < supportedDRMsCount; i++) {
                  byte[] uuid = new byte[16];
                  in.next().getBytesValue().copyTo(uuid, 0);
  
                  supportedSchemes[i] = DrmInfo.bytesToUUID(uuid);
  
                  Log.v(TAG, "DrmInfo() supportedScheme[" + i + "]: " + supportedSchemes[i]);
              }
  
              Log.v(TAG, "DrmInfo.create() psshsize: " + pssh.length
                      + " supportedDRMsCount: " + supportedDRMsCount);
              return new DrmInfo(mapPssh, supportedSchemes);
          }
  
          private DrmInfo makeCopy() {
              return new DrmInfo(this.mMapPssh, this.mSupportedSchemes);
          }
  
          private static String arrToHex(byte[] bytes) {
              String out = "0x";
              for (int i = 0; i < bytes.length; i++) {
                  out += String.format("%02x", bytes[i]);
              }
  
              return out;
          }
  
          private static UUID bytesToUUID(byte[] uuid) {
              long msb = 0, lsb = 0;
              for (int i = 0; i < 8; i++) {
                  msb |= (((long) uuid[i]     & 0xff) << (8 * (7 - i)));
                  lsb |= (((long) uuid[i + 8] & 0xff) << (8 * (7 - i)));
              }
  
              return new UUID(msb, lsb);
          }
  
          private static Map<UUID, byte[]> parsePSSH(byte[] pssh, int psshsize) {
              Map<UUID, byte[]> result = new HashMap<UUID, byte[]>();
  
              final int uuidSize = 16;
              final int dataLenSize = 4;
  
              int len = psshsize;
              int numentries = 0;
              int i = 0;
  
              while (len > 0) {
                  if (len < uuidSize) {
                      Log.w(TAG, String.format("parsePSSH: len is too short to parse "
                                               + "UUID: (%d < 16) pssh: %d", len, psshsize));
                      return null;
                  }
  
                  byte[] subset = Arrays.copyOfRange(pssh, i, i + uuidSize);
                  UUID uuid = bytesToUUID(subset);
                  i += uuidSize;
                  len -= uuidSize;
  
                  // get data length
                  if (len < 4) {
                      Log.w(TAG, String.format("parsePSSH: len is too short to parse "
                                               + "datalen: (%d < 4) pssh: %d", len, psshsize));
                      return null;
                  }
  
                  subset = Arrays.copyOfRange(pssh, i, i + dataLenSize);
                  int datalen = (ByteOrder.nativeOrder() == ByteOrder.LITTLE_ENDIAN)
                          ? ((subset[3] & 0xff) << 24) | ((subset[2] & 0xff) << 16)
                          | ((subset[1] & 0xff) <<  8) |  (subset[0] & 0xff)        :
                          ((subset[0] & 0xff) << 24) | ((subset[1] & 0xff) << 16)
                          | ((subset[2] & 0xff) <<  8) |  (subset[3] & 0xff);
                  i += dataLenSize;
                  len -= dataLenSize;
  
                  if (len < datalen) {
                      Log.w(TAG, String.format("parsePSSH: len is too short to parse "
                                               + "data: (%d < %d) pssh: %d", len, datalen, psshsize));
                      return null;
                  }
  
                  byte[] data = Arrays.copyOfRange(pssh, i, i + datalen);
  
                  // skip the data
                  i += datalen;
                  len -= datalen;
  
                  Log.v(TAG, String.format("parsePSSH[%d]: <%s, %s> pssh: %d",
                                           numentries, uuid, arrToHex(data), psshsize));
                  numentries++;
                  result.put(uuid, data);
              }
  
              return result;
          }
      };  // DrmInfo
  
      /**
       * Thrown when a DRM method is called when there is no active DRM session.
       * Extends MediaDrm.MediaDrmException
       */
      public static final class NoDrmSchemeException extends MediaDrmException {
          public NoDrmSchemeException(@Nullable String detailMessage) {
              super(detailMessage);
          }
      }
  
      private native void native_prepareDrm(
              long srcId, @NonNull byte[] uuid, @NonNull byte[] drmSessionId);
  
      // Instantiated from the native side
      @SuppressWarnings("unused")
      private static class StreamEventCallback extends AudioTrack.StreamEventCallback {
          public long mJAudioTrackPtr;
          public long mNativeCallbackPtr;
          public long mUserDataPtr;
  
          StreamEventCallback(long jAudioTrackPtr, long nativeCallbackPtr, long userDataPtr) {
              super();
              mJAudioTrackPtr = jAudioTrackPtr;
              mNativeCallbackPtr = nativeCallbackPtr;
              mUserDataPtr = userDataPtr;
          }
  
          @Override
          public void onTearDown(AudioTrack track) {
              native_stream_event_onTearDown(mNativeCallbackPtr, mUserDataPtr);
          }
  
          @Override
          public void onPresentationEnded(AudioTrack track) {
              native_stream_event_onStreamPresentationEnd(mNativeCallbackPtr, mUserDataPtr);
          }
  
          @Override
          public void onDataRequest(AudioTrack track, int size) {
              native_stream_event_onStreamDataRequest(
                      mJAudioTrackPtr, mNativeCallbackPtr, mUserDataPtr);
          }
      }
  
      /**
       * Returns a byte[] containing the remainder of 'in', closing it when done.
       */
      private static byte[] readInputStreamFully(InputStream in) throws IOException {
          try {
              return readInputStreamFullyNoClose(in);
          } finally {
              in.close();
          }
      }
  
      /**
       * Returns a byte[] containing the remainder of 'in'.
       */
      private static byte[] readInputStreamFullyNoClose(InputStream in) throws IOException {
          ByteArrayOutputStream bytes = new ByteArrayOutputStream();
          byte[] buffer = new byte[1024];
          int count;
          while ((count = in.read(buffer)) != -1) {
              bytes.write(buffer, 0, count);
          }
          return bytes.toByteArray();
      }
  
      private static byte[] getByteArrayFromUUID(@NonNull UUID uuid) {
          long msb = uuid.getMostSignificantBits();
          long lsb = uuid.getLeastSignificantBits();
  
          byte[] uuidBytes = new byte[16];
          for (int i = 0; i < 8; ++i) {
              uuidBytes[i] = (byte) (msb >>> (8 * (7 - i)));
              uuidBytes[8 + i] = (byte) (lsb >>> (8 * (7 - i)));
          }
  
          return uuidBytes;
      }
  
      private static class TimedTextUtil {
          // These keys must be in sync with the keys in TextDescription2.h
          private static final int KEY_START_TIME                     = 7; // int
          private static final int KEY_STRUCT_TEXT_POS               = 14; // TextPos
          private static final int KEY_STRUCT_TEXT                   = 16; // Text
          private static final int KEY_GLOBAL_SETTING               = 101;
          private static final int KEY_LOCAL_SETTING                = 102;
  
          private static TimedText parsePlayerMessage(PlayerMessage playerMsg) {
              if (playerMsg.getValuesCount() == 0) {
                  return null;
              }
  
              String textChars = null;
              Rect textBounds = null;
              Iterator<Value> in = playerMsg.getValuesList().iterator();
              int type = in.next().getInt32Value();
              if (type == KEY_LOCAL_SETTING) {
                  type = in.next().getInt32Value();
                  if (type != KEY_START_TIME) {
                      return null;
                  }
                  int startTimeMs = in.next().getInt32Value();
  
                  type = in.next().getInt32Value();
                  if (type != KEY_STRUCT_TEXT) {
                      return null;
                  }
  
                  byte[] text = in.next().getBytesValue().toByteArray();
                  if (text == null || text.length == 0) {
                      textChars = null;
                  } else {
                      textChars = new String(text);
                  }
  
              } else if (type != KEY_GLOBAL_SETTING) {
                  Log.w(TAG, "Invalid timed text key found: " + type);
                  return null;
              }
              if (in.hasNext()) {
                  type = in.next().getInt32Value();
                  if (type == KEY_STRUCT_TEXT_POS) {
                      int top = in.next().getInt32Value();
                      int left = in.next().getInt32Value();
                      int bottom = in.next().getInt32Value();
                      int right = in.next().getInt32Value();
                      textBounds = new Rect(left, top, right, bottom);
                  }
              }
              return null;
              /* TimedText c-tor usage is temporarily commented out.
               * TODO(b/117527789): use SUBTITLE path for MEDIA_MIMETYPE_TEXT_3GPP track
               *                    and remove TimedText path from MediaPlayer2.
              return new TimedText(textChars, textBounds);
              */
          }
      }
  
      private Object addTask(Task task) {
          synchronized (mTaskLock) {
              mPendingTasks.add(task);
              processPendingTask_l();
          }
          return task;
      }
  
      @GuardedBy("mTaskLock")
      private void processPendingTask_l() {
          if (mCurrentTask != null) {
              return;
          }
          if (!mPendingTasks.isEmpty()) {
              Task task = mPendingTasks.remove(0);
              mCurrentTask = task;
              mTaskHandler.post(task);
          }
      }
  
      private abstract class Task implements Runnable {
          final long mTaskId = mTaskIdGenerator.getAndIncrement();
          private final int mMediaCallType;
          private final boolean mNeedToWaitForEventToComplete;
          private DataSourceDesc mDSD;
  
          Task(int mediaCallType, boolean needToWaitForEventToComplete) {
              mMediaCallType = mediaCallType;
              mNeedToWaitForEventToComplete = needToWaitForEventToComplete;
          }
  
          abstract void process() throws IOException, NoDrmSchemeException;
  
          @Override
          public void run() {
              int status = CALL_STATUS_NO_ERROR;
              try {
                  if (mMediaCallType != CALL_COMPLETED_NOTIFY_WHEN_COMMAND_LABEL_REACHED
                          && getState() == PLAYER_STATE_ERROR) {
                      status = CALL_STATUS_INVALID_OPERATION;
                  } else {
                      if (mMediaCallType == CALL_COMPLETED_SEEK_TO) {
                          synchronized (mTaskLock) {
                              if (!mPendingTasks.isEmpty()) {
                                  Task nextTask = mPendingTasks.get(0);
                                  if (nextTask.mMediaCallType == mMediaCallType) {
                                      throw new CommandSkippedException(
                                              "consecutive seekTo is skipped except last one");
                                  }
                              }
                          }
                      }
                      process();
                  }
              } catch (IllegalStateException e) {
                  status = CALL_STATUS_INVALID_OPERATION;
              } catch (IllegalArgumentException e) {
                  status = CALL_STATUS_BAD_VALUE;
              } catch (SecurityException e) {
                  status = CALL_STATUS_PERMISSION_DENIED;
              } catch (IOException e) {
                  status = CALL_STATUS_ERROR_IO;
              } catch (NoDrmSchemeException e) {
                  status = CALL_STATUS_NO_DRM_SCHEME;
              } catch (CommandSkippedException e) {
                  status = CALL_STATUS_SKIPPED;
              } catch (Exception e) {
                  status = CALL_STATUS_ERROR_UNKNOWN;
              }
              mDSD = getCurrentDataSource();
  
              if (mMediaCallType != CALL_COMPLETED_SEEK_TO) {
                  synchronized (mTaskLock) {
                      mIsPreviousCommandSeekTo = false;
                  }
              }
  
              // TODO: Make native implementations asynchronous and let them send notifications.
              if (!mNeedToWaitForEventToComplete || status != CALL_STATUS_NO_ERROR) {
  
                  sendCompleteNotification(status);
  
                  synchronized (mTaskLock) {
                      mCurrentTask = null;
                      processPendingTask_l();
                  }
              }
          }
  
          private void sendCompleteNotification(int status) {
              // In {@link #notifyWhenCommandLabelReached} case, a separate callback
              // {@link #onCommandLabelReached} is already called in {@code process()}.
              // CALL_COMPLETED_PREPARE_DRM is sent via DrmEventCallback#onDrmPrepared
              if (mMediaCallType == CALL_COMPLETED_NOTIFY_WHEN_COMMAND_LABEL_REACHED
                      || mMediaCallType == CALL_COMPLETED_PREPARE_DRM) {
                  return;
              }
              sendEvent(new EventNotifier() {
                  @Override
                  public void notify(EventCallback callback) {
                      callback.onCallCompleted(
                              MediaPlayer2.this, mDSD, mMediaCallType, status);
                  }
              });
          }
      };
  
      private final class CommandSkippedException extends RuntimeException {
          CommandSkippedException(String detailMessage) {
              super(detailMessage);
          }
      };
  
      // Modular DRM
      private final Map<UUID, MediaDrm> mDrmObjs = Collections.synchronizedMap(new HashMap<>());
      private class DrmHandle {
  
          static final int PROVISION_TIMEOUT_MS = 60000;
  
          final DataSourceDesc mDSD;
          final long mSrcId;
  
          //--- guarded by |this| start
          MediaDrm mDrmObj;
          byte[] mDrmSessionId;
          UUID mActiveDrmUUID;
          boolean mDrmConfigAllowed;
          boolean mDrmProvisioningInProgress;
          boolean mPrepareDrmInProgress;
          Future<?> mProvisionResult;
          DrmPreparationInfo mPrepareInfo;
          //--- guarded by |this| end
  
          DrmHandle(DataSourceDesc dsd, long srcId) {
              mDSD = dsd;
              mSrcId = srcId;
          }
  
          void prepare(UUID uuid) throws UnsupportedSchemeException,
                  ResourceBusyException, NotProvisionedException, InterruptedException,
                  ExecutionException, TimeoutException {
              Log.v(TAG, "prepareDrm: uuid: " + uuid);
  
              synchronized (this) {
                  if (mActiveDrmUUID != null) {
                      final String msg = "prepareDrm(): Wrong usage: There is already "
                              + "an active DRM scheme with " + uuid;
                      Log.e(TAG, msg);
                      throw new IllegalStateException(msg);
                  }
  
                  if (mPrepareDrmInProgress) {
                      final String msg = "prepareDrm(): Wrong usage: There is already "
                              + "a pending prepareDrm call.";
                      Log.e(TAG, msg);
                      throw new IllegalStateException(msg);
                  }
  
                  if (mDrmProvisioningInProgress) {
                      final String msg = "prepareDrm(): Unexpectd: Provisioning already in progress";
                      Log.e(TAG, msg);
                      throw new IllegalStateException(msg);
                  }
  
                  // shouldn't need this; just for safeguard
                  cleanDrmObj();
  
                  mPrepareDrmInProgress = true;
  
                  try {
                      // only creating the DRM object to allow pre-openSession configuration
                      prepareDrm_createDrmStep(uuid);
                  } catch (Exception e) {
                      Log.w(TAG, "prepareDrm(): Exception ", e);
                      mPrepareDrmInProgress = false;
                      throw e;
                  }
  
                  mDrmConfigAllowed = true;
              }  // synchronized
  
              // call the callback outside the lock
              sendDrmEventWait(new DrmEventNotifier<Void>() {
                  @Override
                  public Void notifyWait(DrmEventCallback callback) {
                      callback.onDrmConfig(MediaPlayer2.this, mDSD, mDrmObj);
                      return null;
                  }
              });
  
              synchronized (this) {
                  mDrmConfigAllowed = false;
                  boolean earlyExit = false;
  
                  try {
                      prepareDrm_openSessionStep(uuid);
  
                      this.mActiveDrmUUID = uuid;
                      mPrepareDrmInProgress = false;
                  } catch (IllegalStateException e) {
                      final String msg = "prepareDrm(): Wrong usage: The player must be "
                              + "in the prepared state to call prepareDrm().";
                      Log.e(TAG, msg);
                      earlyExit = true;
                      mPrepareDrmInProgress = false;
                      throw new IllegalStateException(msg);
                  } catch (NotProvisionedException e) {
                      Log.w(TAG, "prepareDrm: NotProvisionedException", e);
                      throw e;
                  } catch (Exception e) {
                      Log.e(TAG, "prepareDrm: Exception " + e);
                      earlyExit = true;
                      mPrepareDrmInProgress = false;
                      throw e;
                  } finally {
                      if (earlyExit) {  // clean up object if didn't succeed
                          cleanDrmObj();
                      }
                  }  // finally
              }  // synchronized
          }
  
          void prepareDrm_createDrmStep(UUID uuid)
                  throws UnsupportedSchemeException {
              Log.v(TAG, "prepareDrm_createDrmStep: UUID: " + uuid);
  
              try {
                  mDrmObj = mDrmObjs.computeIfAbsent(uuid, scheme -> {
                      try {
                          return new MediaDrm(scheme);
                      } catch (UnsupportedSchemeException e) {
                          throw new IllegalArgumentException(e);
                      }
                  });
                  Log.v(TAG, "prepareDrm_createDrmStep: Created mDrmObj=" + mDrmObj);
              } catch (Exception e) { // UnsupportedSchemeException
                  Log.e(TAG, "prepareDrm_createDrmStep: MediaDrm failed with " + e);
                  throw e;
              }
          }
  
          void prepareDrm_openSessionStep(UUID uuid)
                  throws NotProvisionedException, ResourceBusyException {
              Log.v(TAG, "prepareDrm_openSessionStep: uuid: " + uuid);
  
              // TODO:
              // don't need an open session for a future specialKeyReleaseDrm mode but we should do
              // it anyway so it raises provisioning error if needed. We'd rather handle provisioning
              // at prepareDrm/openSession rather than getDrmKeyRequest/provideDrmKeyResponse
              try {
                  mDrmSessionId = mDrmObj.openSession();
                  Log.v(TAG, "prepareDrm_openSessionStep: mDrmSessionId=" + mDrmSessionId);
  
                  // Sending it down to native/mediaserver to create the crypto object
                  // This call could simply fail due to bad player state, e.g., after play().
                  final MediaPlayer2 mp2 = MediaPlayer2.this;
                  mp2.native_prepareDrm(mSrcId, getByteArrayFromUUID(uuid), mDrmSessionId);
                  Log.v(TAG, "prepareDrm_openSessionStep: native_prepareDrm/Crypto succeeded");
  
              } catch (Exception e) { //ResourceBusyException, NotProvisionedException
                  Log.e(TAG, "prepareDrm_openSessionStep: open/crypto failed with " + e);
                  throw e;
              }
  
          }
  
          int handleProvisioninig(UUID uuid, long taskId) {
              synchronized (this) {
                  if (mDrmProvisioningInProgress) {
                      Log.e(TAG, "handleProvisioninig: Unexpected mDrmProvisioningInProgress");
                      return PREPARE_DRM_STATUS_PREPARATION_ERROR;
                  }
  
                  MediaDrm.ProvisionRequest provReq = mDrmObj.getProvisionRequest();
                  if (provReq == null) {
                      Log.e(TAG, "handleProvisioninig: getProvisionRequest returned null.");
                      return PREPARE_DRM_STATUS_PREPARATION_ERROR;
                  }
  
                  Log.v(TAG, "handleProvisioninig provReq "
                          + " data: " + provReq.getData() + " url: " + provReq.getDefaultUrl());
  
                  // networking in a background thread
                  mDrmProvisioningInProgress = true;
  
                  mProvisionResult = sDrmThreadPool.submit(newProvisioningTask(uuid, taskId));
  
                  return PREPARE_DRM_STATUS_SUCCESS;
              }
          }
  
          void provision(UUID uuid, long taskId) {
  
              MediaDrm.ProvisionRequest provReq = mDrmObj.getProvisionRequest();
              String urlStr = provReq.getDefaultUrl();
              urlStr += "&signedRequest=" + new String(provReq.getData());
              Log.v(TAG, "handleProvisioninig: Thread is initialised url: " + urlStr);
  
              byte[] response = null;
              boolean provisioningSucceeded = false;
              int status = PREPARE_DRM_STATUS_PREPARATION_ERROR;
              try {
                  URL url = new URL(urlStr);
                  final HttpURLConnection connection = (HttpURLConnection) url.openConnection();
                  try {
                      connection.setRequestMethod("POST");
                      connection.setDoOutput(false);
                      connection.setDoInput(true);
                      connection.setConnectTimeout(PROVISION_TIMEOUT_MS);
                      connection.setReadTimeout(PROVISION_TIMEOUT_MS);
  
                      connection.connect();
                      response = readInputStreamFully(connection.getInputStream());
  
                      Log.v(TAG, "handleProvisioninig: Thread run: response " +
                              response.length + " " + response);
                  } catch (Exception e) {
                      status = PREPARE_DRM_STATUS_PROVISIONING_NETWORK_ERROR;
                      Log.w(TAG, "handleProvisioninig: Thread run: connect " + e + " url: " + url);
                  } finally {
                      connection.disconnect();
                  }
              } catch (Exception e)   {
                  status = PREPARE_DRM_STATUS_PROVISIONING_NETWORK_ERROR;
                  Log.w(TAG, "handleProvisioninig: Thread run: openConnection " + e);
              }
  
              if (response != null) {
                  try {
                      mDrmObj.provideProvisionResponse(response);
                      Log.v(TAG, "handleProvisioninig: Thread run: " +
                              "provideProvisionResponse SUCCEEDED!");
  
                      provisioningSucceeded = true;
                  } catch (Exception e) {
                      status = PREPARE_DRM_STATUS_PROVISIONING_SERVER_ERROR;
                      Log.w(TAG, "handleProvisioninig: Thread run: " +
                              "provideProvisionResponse " + e);
                  }
              }
  
              boolean succeeded = false;
  
              synchronized (this) {
                  // continuing with prepareDrm
                  if (provisioningSucceeded) {
                      succeeded = resumePrepare(uuid);
                      status = (succeeded) ?
                              PREPARE_DRM_STATUS_SUCCESS :
                              PREPARE_DRM_STATUS_PREPARATION_ERROR;
                  }
                  mDrmProvisioningInProgress = false;
                  mPrepareDrmInProgress = false;
                  if (!succeeded) {
                      cleanDrmObj();  // cleaning up if it hasn't gone through while in the lock
                  }
              }  // synchronized
  
              // calling the callback outside the lock
              finishPrepare(status);
  
              synchronized (mTaskLock) {
                  if (mCurrentTask != null
                          && mCurrentTask.mTaskId == taskId
                          && mCurrentTask.mMediaCallType == CALL_COMPLETED_PREPARE_DRM
                          && mCurrentTask.mNeedToWaitForEventToComplete) {
                      mCurrentTask = null;
                      processPendingTask_l();
                  }
              }
          }
  
          Runnable newProvisioningTask(UUID uuid, long taskId) {
              return new Runnable() {
                  @Override
                  public void run() {
                      provision(uuid, taskId);
                  }
              };
          }
  
          boolean resumePrepare(UUID uuid) {
              Log.v(TAG, "resumePrepareDrm: uuid: " + uuid);
  
              // mDrmLock is guaranteed to be held
              boolean success = false;
              try {
                  // resuming
                  prepareDrm_openSessionStep(uuid);
  
                  this.mActiveDrmUUID = uuid;
  
                  success = true;
              } catch (Exception e) {
                  Log.w(TAG, "handleProvisioninig: Thread run native_prepareDrm resume failed:" + e);
                  // mDrmObj clean up is done by the caller
              }
  
              return success;
          }
  
          synchronized boolean setPreparationInfo(DrmPreparationInfo prepareInfo) {
              if (prepareInfo == null || !prepareInfo.isValid() || mPrepareInfo != null) {
                  return false;
              }
              mPrepareInfo = prepareInfo;
              return true;
          }
  
          void finishPrepare(int status) {
              if (status != PREPARE_DRM_STATUS_SUCCESS) {
                  notifyPrepared(status, null);
                  return;
              }
  
              if (mPrepareInfo == null) {
                  // Deprecated: this can only happen when using MediaPlayer Version 1 APIs
                  notifyPrepared(status, null);
                  return;
              }
  
              final byte[] keySetId = mPrepareInfo.mKeySetId;
              if (keySetId != null) {
                  try {
                      mDrmObj.restoreKeys(mDrmSessionId, keySetId);
                      notifyPrepared(PREPARE_DRM_STATUS_SUCCESS, keySetId);
                  } catch (Exception e) {
                      notifyPrepared(PREPARE_DRM_STATUS_RESTORE_ERROR, keySetId);
                  }
                  return;
              }
  
              sDrmThreadPool.submit(newKeyExchangeTask());
          }
  
          Runnable newKeyExchangeTask() {
              return new Runnable() {
                  @Override
                  public void run() {
                      final byte[] initData = mPrepareInfo.mInitData;
                      final String mimeType = mPrepareInfo.mMimeType;
                      final int keyType = mPrepareInfo.mKeyType;
                      final Map<String, String> optionalParams = mPrepareInfo.mOptionalParameters;
                      byte[] keySetId = null;
                      try {
                          KeyRequest req;
                          req = getDrmKeyRequest(null, initData, mimeType, keyType, optionalParams);
                          byte[] response = sendDrmEventWait(new DrmEventNotifier<byte[]>() {
                              @Override
                              public byte[] notifyWait(DrmEventCallback callback) {
                                  final MediaPlayer2 mp = MediaPlayer2.this;
                                  return callback.onDrmKeyRequest(mp, mDSD, req);
                              }
                          });
                          keySetId = provideDrmKeyResponse(null, response);
                      } catch (Exception e) {
                      }
                      if (keySetId == null) {
                          notifyPrepared(PREPARE_DRM_STATUS_KEY_EXCHANGE_ERROR, null);
                      } else {
                          notifyPrepared(PREPARE_DRM_STATUS_SUCCESS, keySetId);
                      }
                  }
              };
          }
  
          void notifyPrepared(final int status, byte[] keySetId) {
  
              Message msg;
              if (status == PREPARE_DRM_STATUS_SUCCESS) {
                  msg = mTaskHandler.obtainMessage(
                          MEDIA_DRM_PREPARED, 0, 0, null);
              } else {
                  msg = mTaskHandler.obtainMessage(
                          MEDIA_ERROR, status, MEDIA_ERROR_UNKNOWN, null);
              }
              mTaskHandler.post(new Runnable() {
                  @Override
                  public void run() {
                      mTaskHandler.handleMessage(msg, mSrcId);
                  }
              });
  
              sendDrmEvent(new DrmEventNotifier() {
                  @Override
                  public void notify(DrmEventCallback callback) {
                      callback.onDrmPrepared(MediaPlayer2.this, mDSD, status,
                              keySetId);
                  }
              });
  
          }
  
          void cleanDrmObj() {
              // the caller holds mDrmLock
              Log.v(TAG, "cleanDrmObj: mDrmObj=" + mDrmObj + " mDrmSessionId=" + mDrmSessionId);
  
              if (mDrmSessionId != null)    {
                  mDrmObj.closeSession(mDrmSessionId);
                  mDrmSessionId = null;
              }
          }
  
          void release() throws NoDrmSchemeException {
              synchronized (this) {
                  Log.v(TAG, "releaseDrm:");
  
                  if (mActiveDrmUUID == null) {
                      Log.e(TAG, "releaseDrm(): No active DRM scheme to release.");
                      throw new NoDrmSchemeException(
                              "releaseDrm: No active DRM scheme to release.");
                  }
  
                  try {
                      // we don't have the player's state in this layer. The below call raises
                      // exception if we're in a non-stopped/prepared state.
  
                      // for cleaning native/mediaserver crypto object
                      native_releaseDrm(mSrcId);
  
                      // for cleaning client-side MediaDrm object; only called if above has succeeded
                      cleanDrmObj();
  
                      this.mActiveDrmUUID = null;
                  } catch (IllegalStateException e) {
                      Log.w(TAG, "releaseDrm: Exception ", e);
                      throw new IllegalStateException(
                              "releaseDrm: The player is not in a valid state.");
                  } catch (Exception e) {
                      Log.e(TAG, "releaseDrm: Exception ", e);
                  }
              }  // synchronized
          }
  
          void cleanup() {
              synchronized (this) {
                  Log.v(TAG, "cleanupDrm: " +
                          " mProvisioningTask=" + mProvisionResult +
                          " mPrepareDrmInProgress=" + mPrepareDrmInProgress +
                          " mActiveDrmScheme=" + mActiveDrmUUID);
  
                  if (mProvisionResult != null) {
                      // timeout; relying on HttpUrlConnection
                      try {
                          mProvisionResult.get();
                      }
                      catch (InterruptedException | ExecutionException e) {
                          Log.w(TAG, "resetDrmState: ProvThread.join Exception " + e);
                      }
                  }
  
                  // set to false to avoid duplicate release calls
                  this.mActiveDrmUUID = null;
  
                  native_releaseDrm(mSrcId);
                  cleanDrmObj();
              }   // synchronized
          }
  
          Runnable newCleanupTask() {
              return new Runnable() {
                  @Override
                  public void run() {
                      cleanup();
                  }
              };
          }
  
          MediaDrm.KeyRequest getDrmKeyRequest(
                  byte[] keySetId, byte[] initData,
                  String mimeType, int keyType,
                  Map<String, String> optionalParameters)
                  throws NoDrmSchemeException {
              synchronized (this) {
                  if (mActiveDrmUUID == null) {
                      Log.e(TAG, "getDrmKeyRequest NoDrmSchemeException");
                      throw new NoDrmSchemeException(
                              "getDrmKeyRequest: Has to set a DRM scheme first.");
                  }
  
                  try {
                      byte[] scope = (keyType != MediaDrm.KEY_TYPE_RELEASE) ?
                              mDrmSessionId : // sessionId for KEY_TYPE_STREAMING/OFFLINE
                              keySetId;                  // keySetId for KEY_TYPE_RELEASE
  
                      HashMap<String, String> hmapOptionalParameters =
                              (optionalParameters != null)
                              ? new HashMap<String, String>(optionalParameters)
                              : null;
  
                      MediaDrm.KeyRequest request = mDrmObj.getKeyRequest(
                              scope, initData, mimeType, keyType, hmapOptionalParameters);
                      Log.v(TAG, "getDrmKeyRequest:   --> request: " + request);
  
                      return request;
  
                  } catch (NotProvisionedException e) {
                      Log.w(TAG, "getDrmKeyRequest NotProvisionedException: " +
                              "Unexpected. Shouldn't have reached here.");
                      throw new IllegalStateException("getDrmKeyRequest: provisioning error.");
                  } catch (Exception e) {
                      Log.w(TAG, "getDrmKeyRequest Exception " + e);
                      throw e;
                  }
  
              }
          }
  
          byte[] provideDrmKeyResponse(byte[] keySetId, byte[] response)
                  throws NoDrmSchemeException, DeniedByServerException {
              synchronized (this) {
  
                  if (mActiveDrmUUID == null) {
                      Log.e(TAG, "getDrmKeyRequest NoDrmSchemeException");
                      throw new NoDrmSchemeException(
                              "getDrmKeyRequest: Has to set a DRM scheme first.");
                  }
  
                  try {
                      byte[] scope = (keySetId == null) ?
                                      mDrmSessionId : // sessionId for KEY_TYPE_STREAMING/OFFLINE
                                      keySetId;                  // keySetId for KEY_TYPE_RELEASE
  
                      byte[] keySetResult = mDrmObj.provideKeyResponse(scope, response);
  
                      Log.v(TAG, "provideDrmKeyResponse: keySetId: " + keySetId
                              + " response: " + response + " --> " + keySetResult);
  
  
                      return keySetResult;
  
                  } catch (NotProvisionedException e) {
                      Log.w(TAG, "provideDrmKeyResponse NotProvisionedException: " +
                              "Unexpected. Shouldn't have reached here.");
                      throw new IllegalStateException("provideDrmKeyResponse: " +
                              "Unexpected provisioning error.");
                  } catch (Exception e) {
                      Log.w(TAG, "provideDrmKeyResponse Exception " + e);
                      throw e;
                  }
              }
          }
  
          void restoreDrmKeys(byte[] keySetId)
                  throws NoDrmSchemeException {
              synchronized (this) {
                  if (mActiveDrmUUID == null) {
                      Log.w(TAG, "restoreDrmKeys NoDrmSchemeException");
                      throw new NoDrmSchemeException(
                              "restoreDrmKeys: Has to set a DRM scheme first.");
                  }
  
                  try {
                      mDrmObj.restoreKeys(mDrmSessionId, keySetId);
                  } catch (Exception e) {
                      Log.w(TAG, "restoreKeys Exception " + e);
                      throw e;
                  }
              }
          }
  
          String getDrmPropertyString(String propertyName)
                  throws NoDrmSchemeException {
              String v;
              synchronized (this) {
  
                  if (mActiveDrmUUID == null && !mDrmConfigAllowed) {
                      Log.w(TAG, "getDrmPropertyString NoDrmSchemeException");
                      throw new NoDrmSchemeException(
                              "getDrmPropertyString: Has to prepareDrm() first.");
                  }
  
                  try {
                      v = mDrmObj.getPropertyString(propertyName);
                  } catch (Exception e) {
                      Log.w(TAG, "getDrmPropertyString Exception " + e);
                      throw e;
                  }
              }   // synchronized
  
              Log.v(TAG, "getDrmPropertyString: propertyName: " + propertyName + " --> value: " + v);
  
              return v;
          }
  
          void setDrmPropertyString(String propertyName, String value)
                  throws NoDrmSchemeException {
              synchronized (this) {
  
                  if ( mActiveDrmUUID == null && !mDrmConfigAllowed ) {
                      Log.w(TAG, "setDrmPropertyString NoDrmSchemeException");
                      throw new NoDrmSchemeException(
                              "setDrmPropertyString: Has to prepareDrm() first.");
                  }
  
                  try {
                      mDrmObj.setPropertyString(propertyName, value);
                  } catch ( Exception e ) {
                      Log.w(TAG, "setDrmPropertyString Exception " + e);
                      throw e;
                  }
              }
          }
  
      }
  
      final class SourceInfo {
          final DataSourceDesc mDSD;
          final long mId = mSrcIdGenerator.getAndIncrement();
          AtomicInteger mBufferedPercentage = new AtomicInteger(0);
          boolean mClosed = false;
          int mPrepareBarrier = 1;
  
          // m*AsNextSource (below) only applies to pending data sources in the playlist;
          // the meanings of mCurrentSourceInfo.{mStateAsNextSource,mPlayPendingAsNextSource}
          // are undefined.
          int mStateAsNextSource = NEXT_SOURCE_STATE_INIT;
          boolean mPlayPendingAsNextSource = false;
  
          // Modular DRM
          final DrmHandle mDrmHandle;
          DrmInfo mDrmInfo;
          boolean mDrmInfoResolved;
  
          SourceInfo(DataSourceDesc dsd) {
              this.mDSD = dsd;
              mDrmHandle = new DrmHandle(dsd, mId);
          }
  
          void close() {
              synchronized (this) {
                  if (!mClosed) {
                      if (mDSD != null) {
                          mDSD.close();
                      }
                      mClosed = true;
                  }
              }
          }
  
          @Override
          public String toString() {
              return String.format("%s(%d)", SourceInfo.class.getName(), mId);
          }
  
      }
  
      private SourceInfo getSourceInfo(long srcId) {
          synchronized (mSrcLock) {
              if (isCurrentSource(srcId)) {
                  return mCurrentSourceInfo;
              }
              if (isNextSource(srcId)) {
                  return mNextSourceInfos.peek();
              }
          }
          return null;
      }
  
      private SourceInfo getSourceInfo(DataSourceDesc dsd) {
          synchronized (mSrcLock) {
              if (isCurrentSource(dsd)) {
                  return mCurrentSourceInfo;
              }
              if (isNextSource(dsd)) {
                  return mNextSourceInfos.peek();
              }
          }
          return null;
      }
  
      private boolean isCurrentSource(long srcId) {
          synchronized (mSrcLock) {
              return mCurrentSourceInfo != null && mCurrentSourceInfo.mId == srcId;
          }
      }
  
      private boolean isCurrentSource(DataSourceDesc dsd) {
          synchronized (mSrcLock) {
              return mCurrentSourceInfo != null && mCurrentSourceInfo.mDSD == dsd;
          }
      }
  
      private boolean isNextSource(long srcId) {
          SourceInfo nextSourceInfo = mNextSourceInfos.peek();
          return nextSourceInfo != null && nextSourceInfo.mId == srcId;
      }
  
      private boolean isNextSource(DataSourceDesc dsd) {
          SourceInfo nextSourceInfo = mNextSourceInfos.peek();
          return nextSourceInfo != null && nextSourceInfo.mDSD == dsd;
      }
  
      @GuardedBy("mSrcLock")
      private void setCurrentSourceInfo_l(SourceInfo sourceInfo) {
          cleanupSourceInfo(mCurrentSourceInfo);
          mCurrentSourceInfo = sourceInfo;
      }
  
      @GuardedBy("mSrcLock")
      private void clearNextSourceInfos_l() {
          while (!mNextSourceInfos.isEmpty()) {
              cleanupSourceInfo(mNextSourceInfos.poll());
          }
      }
  
      private void cleanupSourceInfo(SourceInfo sourceInfo) {
          if (sourceInfo != null) {
              sourceInfo.close();
              Runnable task = sourceInfo.mDrmHandle.newCleanupTask();
              sDrmThreadPool.submit(task);
          }
      }
  
      private void clearSourceInfos() {
          synchronized (mSrcLock) {
              setCurrentSourceInfo_l(null);
              clearNextSourceInfos_l();
          }
      }
  
      public static final class MetricsConstants {
          private MetricsConstants() {}
  
          /**
           * Key to extract the MIME type of the video track
           * from the {@link MediaPlayer2#getMetrics} return value.
           * The value is a String.
           */
          public static final String MIME_TYPE_VIDEO = "android.media.mediaplayer.video.mime";
  
          /**
           * Key to extract the codec being used to decode the video track
           * from the {@link MediaPlayer2#getMetrics} return value.
           * The value is a String.
           */
          public static final String CODEC_VIDEO = "android.media.mediaplayer.video.codec";
  
          /**
           * Key to extract the width (in pixels) of the video track
           * from the {@link MediaPlayer2#getMetrics} return value.
           * The value is an integer.
           */
          public static final String WIDTH = "android.media.mediaplayer.width";
  
          /**
           * Key to extract the height (in pixels) of the video track
           * from the {@link MediaPlayer2#getMetrics} return value.
           * The value is an integer.
           */
          public static final String HEIGHT = "android.media.mediaplayer.height";
  
          /**
           * Key to extract the count of video frames played
           * from the {@link MediaPlayer2#getMetrics} return value.
           * The value is an integer.
           */
          public static final String FRAMES = "android.media.mediaplayer.frames";
  
          /**
           * Key to extract the count of video frames dropped
           * from the {@link MediaPlayer2#getMetrics} return value.
           * The value is an integer.
           */
          public static final String FRAMES_DROPPED = "android.media.mediaplayer.dropped";
  
          /**
           * Key to extract the MIME type of the audio track
           * from the {@link MediaPlayer2#getMetrics} return value.
           * The value is a String.
           */
          public static final String MIME_TYPE_AUDIO = "android.media.mediaplayer.audio.mime";
  
          /**
           * Key to extract the codec being used to decode the audio track
           * from the {@link MediaPlayer2#getMetrics} return value.
           * The value is a String.
           */
          public static final String CODEC_AUDIO = "android.media.mediaplayer.audio.codec";
  
          /**
           * Key to extract the duration (in milliseconds) of the
           * media being played
           * from the {@link MediaPlayer2#getMetrics} return value.
           * The value is a long.
           */
          public static final String DURATION = "android.media.mediaplayer.durationMs";
  
          /**
           * Key to extract the playing time (in milliseconds) of the
           * media being played
           * from the {@link MediaPlayer2#getMetrics} return value.
           * The value is a long.
           */
          public static final String PLAYING = "android.media.mediaplayer.playingMs";
  
          /**
           * Key to extract the count of errors encountered while
           * playing the media
           * from the {@link MediaPlayer2#getMetrics} return value.
           * The value is an integer.
           */
          public static final String ERRORS = "android.media.mediaplayer.err";
  
          /**
           * Key to extract an (optional) error code detected while
           * playing the media
           * from the {@link MediaPlayer2#getMetrics} return value.
           * The value is an integer.
           */
          public static final String ERROR_CODE = "android.media.mediaplayer.errcode";
  
      }
  
      private void keepAudioSessionIdAlive(int sessionId) {
          synchronized (mSessionIdLock) {
              if (mDummyAudioTrack != null) {
                  if (mDummyAudioTrack.getAudioSessionId() == sessionId) {
                      return;
                  }
                  mDummyAudioTrack.release();
              }
              // TODO: parameters can be optimized
              mDummyAudioTrack = new AudioTrack(AudioManager.STREAM_MUSIC, 44100,
                      AudioFormat.CHANNEL_OUT_MONO, AudioFormat.ENCODING_PCM_16BIT, 2,
                      AudioTrack.MODE_STATIC, sessionId);
          }
      }
  
      private void keepAudioSessionIdAlive(AudioTrack at) {
          synchronized (mSessionIdLock) {
              if (mDummyAudioTrack != null) {
                  if (mDummyAudioTrack.getAudioSessionId() == at.getAudioSessionId()) {
                      at.release();
                      return;
                  }
                  mDummyAudioTrack.release();
              }
              mDummyAudioTrack = at;
          }
      }
  }
  