xref: /frameworks/base/media/java/android/media/MediaPlayer2Impl.java

/*
 * Copyright 2018 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.NonNull;
import android.annotation.Nullable;
import android.app.ActivityThread;
import android.content.ContentProvider;
import android.content.ContentResolver;
import android.content.Context;
import android.content.res.AssetFileDescriptor;
import android.graphics.SurfaceTexture;
import android.media.SubtitleController.Anchor;
import android.media.SubtitleTrack.RenderingWidget;
import android.net.Uri;
import android.os.Handler;
import android.os.HandlerThread;
import android.os.Looper;
import android.os.Message;
import android.os.Parcel;
import android.os.Parcelable;
import android.os.PersistableBundle;
import android.os.PowerManager;
import android.os.Process;
import android.os.SystemProperties;
import android.provider.Settings;
import android.system.ErrnoException;
import android.system.Os;
import android.system.OsConstants;
import android.util.ArrayMap;
import android.util.Log;
import android.util.Pair;
import android.view.Surface;
import android.view.SurfaceHolder;
import android.widget.VideoView;

import com.android.internal.annotations.GuardedBy;
import com.android.internal.util.Preconditions;

import dalvik.system.CloseGuard;

import libcore.io.IoBridge;
import libcore.io.Streams;

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.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.BitSet;
import java.util.HashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Scanner;
import java.util.Set;
import java.util.UUID;
import java.util.Vector;
import java.util.concurrent.Executor;
import java.util.concurrent.atomic.AtomicInteger;

/**
 * @hide
 */
public final class MediaPlayer2Impl extends MediaPlayer2 {
    static {
        System.loadLibrary("media2_jni");
        native_init();
    }

    private final static String TAG = "MediaPlayer2Impl";

    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 EventHandler mEventHandler;
    private PowerManager.WakeLock mWakeLock = null;
    private boolean mScreenOnWhilePlaying;
    private boolean mStayAwake;
    private int mStreamType = AudioManager.USE_DEFAULT_STREAM_TYPE;
    private final CloseGuard mGuard = CloseGuard.get();

    private final Object mSrcLock = new Object();
    //--- guarded by |mSrcLock| start
    private long mSrcIdGenerator = 0;
    private DataSourceDesc mCurrentDSD;
    private long mCurrentSrcId = mSrcIdGenerator++;
    private List<DataSourceDesc> mNextDSDs;
    private long mNextSrcId = mSrcIdGenerator++;
    private int mNextSourceState = NEXT_SOURCE_STATE_INIT;
    private boolean mNextSourcePlayPending = false;
    //--- guarded by |mSrcLock| end

    private AtomicInteger mBufferedPercentageCurrent = new AtomicInteger(0);
    private AtomicInteger mBufferedPercentageNext = new AtomicInteger(0);
    private volatile float mVolume = 1.0f;

    // Modular DRM
    private final Object mDrmLock = new Object();
    //--- guarded by |mDrmLock| start
    private UUID mDrmUUID;
    private DrmInfoImpl mDrmInfoImpl;
    private MediaDrm mDrmObj;
    private byte[] mDrmSessionId;
    private boolean mDrmInfoResolved;
    private boolean mActiveDrmScheme;
    private boolean mDrmConfigAllowed;
    private boolean mDrmProvisioningInProgress;
    private boolean mPrepareDrmInProgress;
    private ProvisioningThread mDrmProvisioningThread;
    //--- guarded by |mDrmLock| end

    private HandlerThread mHandlerThread;
    private final Handler mTaskHandler;
    private final Object mTaskLock = new Object();
    @GuardedBy("mTaskLock")
    private final List<Task> mPendingTasks = new LinkedList<>();
    @GuardedBy("mTaskLock")
    private Task mCurrentTask;

    /**
     * Default constructor.
     * <p>When done with the MediaPlayer2Impl, you should call  {@link #close()},
     * to free the resources. If not released, too many MediaPlayer2Impl instances may
     * result in an exception.</p>
     */
    public MediaPlayer2Impl() {
        Looper looper;
        if ((looper = Looper.myLooper()) != null) {
            mEventHandler = new EventHandler(this, looper);
        } else if ((looper = Looper.getMainLooper()) != null) {
            mEventHandler = new EventHandler(this, looper);
        } else {
            mEventHandler = null;
        }

        mHandlerThread = new HandlerThread("MediaPlayer2TaskThread");
        mHandlerThread.start();
        looper = mHandlerThread.getLooper();
        mTaskHandler = new Handler(looper);

        mTimeProvider = new TimeProvider(this);
        mOpenSubtitleSources = new Vector<InputStream>();
        mGuard.open("close");

        /* Native setup requires a weak reference to our object.
         * It's easier to create it here than in C++.
         */
        native_setup(new WeakReference<MediaPlayer2Impl>(this));
    }

    /**
     * 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.
     */
    @Override
    public void close() {
        synchronized (mGuard) {
            release();
        }
    }

    /**
     * Starts or resumes playback. If playback had previously been paused,
     * playback will continue from where it was paused. If playback had
     * been stopped, or never started before, playback will start at the
     * beginning.
     *
     * @throws IllegalStateException if it is called in an invalid state
     */
    @Override
    public void play() {
        addTask(new Task(CALL_COMPLETED_PLAY, false) {
            @Override
            void process() {
                stayAwake(true);
                _start();
            }
        });
    }

    private native void _start() throws IllegalStateException;

    /**
     * Prepares the player for playback, asynchronously.
     *
     * After setting the datasource and the display surface, you need to either
     * call prepare(). For streams, you should call prepare(),
     * which returns immediately, rather than blocking until enough data has been
     * buffered.
     *
     * @throws IllegalStateException if it is called in an invalid state
     */
    @Override
    public void prepare() {
        addTask(new Task(CALL_COMPLETED_PREPARE, true) {
            @Override
            void process() {
                _prepare();
            }
        });
    }

    public native void _prepare();

    /**
     * Pauses playback. Call play() to resume.
     *
     * @throws IllegalStateException if the internal player engine has not been
     * initialized.
     */
    @Override
    public void pause() {
        addTask(new Task(CALL_COMPLETED_PAUSE, false) {
            @Override
            void process() {
                stayAwake(false);
                _pause();
            }
        });
    }

    private native void _pause() throws IllegalStateException;

    /**
     * Tries to play next data source if applicable.
     *
     * @throws IllegalStateException if it is called in an invalid state
     */
    @Override
    public void skipToNext() {
        addTask(new Task(CALL_COMPLETED_SKIP_TO_NEXT, false) {
            @Override
            void process() {
                // TODO: switch to next data source and play
            }
        });
    }

    /**
     * Gets the current playback position.
     *
     * @return the current position in milliseconds
     */
    @Override
    public native long getCurrentPosition();

    /**
     * Gets the duration of the file.
     *
     * @return the duration in milliseconds, if no duration is available
     *         (for example, if streaming live content), -1 is returned.
     */
    @Override
    public native long getDuration();

    /**
     * Gets the current buffered media source position 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.
     *
     * @return the current buffered media source position in milliseconds
     */
    @Override
    public long getBufferedPosition() {
        // Use cached buffered percent for now.
        return getDuration() * mBufferedPercentageCurrent.get() / 100;
    }

    @Override
    public @PlayerState int getPlayerState() {
        int mediaplayer2State = getMediaPlayer2State();
        int playerState;
        switch (mediaplayer2State) {
            case MEDIAPLAYER2_STATE_IDLE:
                playerState = PLAYER_STATE_IDLE;
                break;
            case MEDIAPLAYER2_STATE_PREPARED:
            case MEDIAPLAYER2_STATE_PAUSED:
                playerState = PLAYER_STATE_PAUSED;
                break;
            case MEDIAPLAYER2_STATE_PLAYING:
                playerState = PLAYER_STATE_PLAYING;
                break;
            case MEDIAPLAYER2_STATE_ERROR:
            default:
                playerState = PLAYER_STATE_ERROR;
                break;
        }

        return playerState;
    }

    /**
     * Gets the current buffering state of the player.
     * During buffering, see {@link #getBufferedPosition()} for the quantifying the amount already
     * buffered.
     */
    @Override
    public @BuffState int getBufferingState() {
        // TODO: use cached state or call native function.
        return BUFFERING_STATE_UNKNOWN;
    }

    /**
     * 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 #prepare()} in order
     * for the audio attributes to become effective thereafter.
     * @param attributes a non-null set of audio attributes
     * @throws IllegalArgumentException if the attributes are null or invalid.
     */
    @Override
    public void setAudioAttributes(@NonNull AudioAttributes attributes) {
        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);
                }
                Parcel pattributes = Parcel.obtain();
                attributes.writeToParcel(pattributes, AudioAttributes.FLATTEN_TAGS);
                setParameter(KEY_PARAMETER_AUDIO_ATTRIBUTES, pattributes);
                pattributes.recycle();
            }
        });
    }

    @Override
    public @NonNull AudioAttributes getAudioAttributes() {
        Parcel pattributes = getParameter(KEY_PARAMETER_AUDIO_ATTRIBUTES);
        AudioAttributes attributes = AudioAttributes.CREATOR.createFromParcel(pattributes);
        pattributes.recycle();
        return attributes;
    }

    /**
     * Sets the data source as described by a DataSourceDesc.
     *
     * @param dsd the descriptor of data source you want to play
     * @throws IllegalStateException if it is called in an invalid state
     * @throws NullPointerException if dsd is null
     */
    @Override
    public void setDataSource(@NonNull DataSourceDesc dsd) {
        addTask(new Task(CALL_COMPLETED_SET_DATA_SOURCE, false) {
            @Override
            void process() {
                Preconditions.checkNotNull(dsd, "the DataSourceDesc cannot be null");
                // TODO: setDataSource could update exist data source
                synchronized (mSrcLock) {
                    mCurrentDSD = dsd;
                    mCurrentSrcId = mSrcIdGenerator++;
                    try {
                        handleDataSource(true /* isCurrent */, dsd, mCurrentSrcId);
                    } catch (IOException e) {
                    }
                }
            }
        });
    }

    /**
     * Sets a single data source as described by a DataSourceDesc which will be played
     * after current data source is finished.
     *
     * @param dsd the descriptor of data source you want to play after current one
     * @throws IllegalStateException if it is called in an invalid state
     * @throws NullPointerException if dsd is null
     */
    @Override
    public void setNextDataSource(@NonNull DataSourceDesc dsd) {
        addTask(new Task(CALL_COMPLETED_SET_NEXT_DATA_SOURCE, false) {
            @Override
            void process() {
                Preconditions.checkNotNull(dsd, "the DataSourceDesc cannot be null");
                synchronized (mSrcLock) {
                    mNextDSDs = new ArrayList<DataSourceDesc>(1);
                    mNextDSDs.add(dsd);
                    mNextSrcId = mSrcIdGenerator++;
                    mNextSourceState = NEXT_SOURCE_STATE_INIT;
                    mNextSourcePlayPending = false;
                }
                int state = getMediaPlayer2State();
                if (state != MEDIAPLAYER2_STATE_IDLE) {
                    synchronized (mSrcLock) {
                        prepareNextDataSource_l();
                    }
                }
            }
        });
    }

    /**
     * Sets a list of data sources to be played sequentially after current data source is done.
     *
     * @param dsds the list of data sources you want to play after current one
     * @throws IllegalStateException if it is called in an invalid state
     * @throws IllegalArgumentException if dsds is null or empty, or contains null DataSourceDesc
     */
    @Override
    public void setNextDataSources(@NonNull List<DataSourceDesc> dsds) {
        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.");
                }
                for (DataSourceDesc dsd : dsds) {
                    if (dsd == null) {
                        throw new IllegalArgumentException(
                                "DataSourceDesc in the source list cannot be null.");
                    }
                }

                synchronized (mSrcLock) {
                    mNextDSDs = new ArrayList(dsds);
                    mNextSrcId = mSrcIdGenerator++;
                    mNextSourceState = NEXT_SOURCE_STATE_INIT;
                    mNextSourcePlayPending = false;
                }
                int state = getMediaPlayer2State();
                if (state != MEDIAPLAYER2_STATE_IDLE) {
                    synchronized (mSrcLock) {
                        prepareNextDataSource_l();
                    }
                }
            }
        });
    }

    @Override
    public @NonNull DataSourceDesc getCurrentDataSource() {
        synchronized (mSrcLock) {
            return mCurrentDSD;
        }
    }

    /**
     * Configures the player to loop on the current data source.
     * @param loop true if the current data source is meant to loop.
     */
    @Override
    public void loopCurrent(boolean loop) {
        addTask(new Task(CALL_COMPLETED_LOOP_CURRENT, false) {
            @Override
            void process() {
                // TODO: set the looping mode, send notification
                setLooping(loop);
            }
        });
    }

    private native void setLooping(boolean looping);

    /**
     * Sets the playback speed.
     * A value of 1.0f is the default playback value.
     * A negative value indicates reverse playback, check {@link #isReversePlaybackSupported()}
     * before using negative values.<br>
     * After changing the playback speed, it is recommended to query the actual speed supported
     * by the player, see {@link #getPlaybackSpeed()}.
     * @param speed the desired playback speed
     */
    @Override
    public void setPlaybackSpeed(float speed) {
        addTask(new Task(CALL_COMPLETED_SET_PLAYBACK_SPEED, false) {
            @Override
            void process() {
                _setPlaybackParams(getPlaybackParams().setSpeed(speed));
            }
        });
    }

    /**
     * Returns the actual playback speed to be used by the player when playing.
     * Note that it may differ from the speed set in {@link #setPlaybackSpeed(float)}.
     * @return the actual playback speed
     */
    @Override
    public float getPlaybackSpeed() {
        return getPlaybackParams().getSpeed();
    }

    /**
     * Indicates whether reverse playback is supported.
     * Reverse playback is indicated by negative playback speeds, see
     * {@link #setPlaybackSpeed(float)}.
     * @return true if reverse playback is supported.
     */
    @Override
    public boolean isReversePlaybackSupported() {
        return false;
    }

    /**
     * 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()}.
     */
    @Override
    public void setPlayerVolume(float volume) {
        addTask(new Task(CALL_COMPLETED_SET_PLAYER_VOLUME, false) {
            @Override
            void process() {
                mVolume = volume;
                _setVolume(volume, volume);
            }
        });
    }

    private native void _setVolume(float leftVolume, float rightVolume);

    /**
     * Returns the current volume of this player to this player.
     * Note that it does not take into account the associated stream volume.
     * @return the player volume.
     */
    @Override
    public float getPlayerVolume() {
        return mVolume;
    }

    /**
     * @return the maximum volume that can be used in {@link #setPlayerVolume(float)}.
     */
    @Override
    public float getMaxPlayerVolume() {
        return 1.0f;
    }

    /**
     * Adds a callback to be notified of events for this player.
     * @param e the {@link Executor} to be used for the events.
     * @param cb the callback to receive the events.
     */
    @Override
    public void registerPlayerEventCallback(@NonNull Executor e,
            @NonNull PlayerEventCallback cb) {
    }

    /**
     * Removes a previously registered callback for player events
     * @param cb the callback to remove
     */
    @Override
    public void unregisterPlayerEventCallback(@NonNull PlayerEventCallback cb) {
    }


    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;

    /*
     * Update the MediaPlayer2Impl SurfaceTexture.
     * Call after setting a new display surface.
     */
    private native void _setVideoSurface(Surface surface);

    /* 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_SET_VIDEO_SCALE_MODE = 6;
    private static final int INVOKE_ID_GET_SELECTED_TRACK = 7;

    /**
     * Create a request parcel which can be routed to the native media
     * player using {@link #invoke(Parcel, Parcel)}. The Parcel
     * returned has the proper InterfaceToken set. The caller should
     * not overwrite that token, i.e it can only append data to the
     * Parcel.
     *
     * @return A parcel suitable to hold a request for the native
     * player.
     * {@hide}
     */
    @Override
    public Parcel newRequest() {
        Parcel parcel = Parcel.obtain();
        return parcel;
    }

    /**
     * Invoke a generic method on the native player using opaque
     * parcels for the request and reply. Both payloads' format is a
     * convention between the java caller and the native player.
     * Must be called after setDataSource or setPlaylist to make sure a native player
     * exists. On failure, a RuntimeException is thrown.
     *
     * @param request Parcel with the data for the extension. The
     * caller must use {@link #newRequest()} to get one.
     *
     * @param reply Output parcel with the data returned by the
     * native player.
     * {@hide}
     */
    @Override
    public void invoke(Parcel request, Parcel reply) {
        int retcode = native_invoke(request, reply);
        reply.setDataPosition(0);
        if (retcode != 0) {
            throw new RuntimeException("failure code: " + retcode);
        }
    }

    @Override
    public void notifyWhenCommandLabelReached(Object label) {
        addTask(new Task(CALL_COMPLETED_NOTIFY_WHEN_COMMAND_LABEL_REACHED, false) {
            @Override
            void process() {
                synchronized (mEventCbLock) {
                    for (Pair<Executor, MediaPlayer2EventCallback> cb : mEventCallbackRecords) {
                        cb.first.execute(() -> cb.second.onCommandLabelReached(
                                MediaPlayer2Impl.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
     * @throws IllegalStateException if the internal player engine has not been
     * initialized or has been released.
     * @hide
     */
    @Override
    public void setDisplay(SurfaceHolder sh) {
        mSurfaceHolder = sh;
        Surface surface;
        if (sh != null) {
            surface = sh.getSurface();
        } else {
            surface = null;
        }
        _setVideoSurface(surface);
        updateSurfaceScreenOn();
    }

    /**
     * Sets the {@link Surface} to be used as the sink for the video portion of
     * the media. This is similar to {@link #setDisplay(SurfaceHolder)}, but
     * does not support {@link #setScreenOnWhilePlaying(boolean)}.  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.
     * @throws IllegalStateException if the internal player engine has not been
     * initialized or has been released.
     */
    @Override
    public void setSurface(Surface surface) {
        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;
                _setVideoSurface(surface);
                updateSurfaceScreenOn();
            }
        });
    }

    /**
     * Sets video scaling mode. To make the target video scaling mode
     * effective during playback, this method must be called after
     * data source is set. If not called, the default video
     * scaling mode is {@link #VIDEO_SCALING_MODE_SCALE_TO_FIT}.
     *
     * <p> The supported video scaling modes are:
     * <ul>
     * <li> {@link #VIDEO_SCALING_MODE_SCALE_TO_FIT}
     * <li> {@link #VIDEO_SCALING_MODE_SCALE_TO_FIT_WITH_CROPPING}
     * </ul>
     *
     * @param mode target video scaling mode. Must be one of the supported
     * video scaling modes; otherwise, IllegalArgumentException will be thrown.
     *
     * @see MediaPlayer2#VIDEO_SCALING_MODE_SCALE_TO_FIT
     * @see MediaPlayer2#VIDEO_SCALING_MODE_SCALE_TO_FIT_WITH_CROPPING
     * @hide
     */
    @Override
    public void setVideoScalingMode(int mode) {
        addTask(new Task(CALL_COMPLETED_SET_VIDEO_SCALING_MODE, false) {
            @Override
            void process() {
                if (!isVideoScalingModeSupported(mode)) {
                    final String msg = "Scaling mode " + mode + " is not supported";
                    throw new IllegalArgumentException(msg);
                }
                Parcel request = Parcel.obtain();
                Parcel reply = Parcel.obtain();
                try {
                    request.writeInt(INVOKE_ID_SET_VIDEO_SCALE_MODE);
                    request.writeInt(mode);
                    invoke(request, reply);
                } finally {
                    request.recycle();
                    reply.recycle();
                }
            }
        });
    }

    /**
     * Discards all pending commands.
     */
    @Override
    public void clearPendingCommands() {
    }

    private void addTask(Task task) {
        synchronized (mTaskLock) {
            mPendingTasks.add(task);
            processPendingTask_l();
        }
    }

    @GuardedBy("mTaskLock")
    private void processPendingTask_l() {
        if (mCurrentTask != null) {
            return;
        }
        if (!mPendingTasks.isEmpty()) {
            Task task = mPendingTasks.remove(0);
            mCurrentTask = task;
            mTaskHandler.post(task);
        }
    }

    private void handleDataSource(boolean isCurrent, @NonNull DataSourceDesc dsd, long srcId)
            throws IOException {
        Preconditions.checkNotNull(dsd, "the DataSourceDesc cannot be null");

        switch (dsd.getType()) {
            case DataSourceDesc.TYPE_CALLBACK:
                handleDataSource(isCurrent,
                                 srcId,
                                 dsd.getMedia2DataSource());
                break;

            case DataSourceDesc.TYPE_FD:
                handleDataSource(isCurrent,
                                 srcId,
                                 dsd.getFileDescriptor(),
                                 dsd.getFileDescriptorOffset(),
                                 dsd.getFileDescriptorLength());
                break;

            case DataSourceDesc.TYPE_URI:
                handleDataSource(isCurrent,
                                 srcId,
                                 dsd.getUriContext(),
                                 dsd.getUri(),
                                 dsd.getUriHeaders(),
                                 dsd.getUriCookies());
                break;

            default:
                break;
        }
    }

    /**
     * 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 managers 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)
            throws IOException {
        // The context and URI usually belong to the calling user. Get a resolver for that user
        // and strip out the userId from the URI if present.
        final ContentResolver resolver = context.getContentResolver();
        final String scheme = uri.getScheme();
        final String authority = ContentProvider.getAuthorityWithoutUserId(uri.getAuthority());
        if (ContentResolver.SCHEME_FILE.equals(scheme)) {
            handleDataSource(isCurrent, srcId, uri.getPath(), null, null);
            return;
        }

        if (ContentResolver.SCHEME_CONTENT.equals(scheme)
                && Settings.AUTHORITY.equals(authority)) {
            // Try cached ringtone first since the actual provider may not be
            // encryption aware, or it may be stored on CE media storage
            final int type = RingtoneManager.getDefaultType(uri);
            final Uri cacheUri = RingtoneManager.getCacheForType(type, context.getUserId());
            final Uri actualUri = RingtoneManager.getActualDefaultRingtoneUri(context, type);
            if (attemptDataSource(isCurrent, srcId, resolver, cacheUri)) {
                return;
            }
            if (attemptDataSource(isCurrent, srcId, resolver, actualUri)) {
                return;
            }
            handleDataSource(isCurrent, srcId, uri.toString(), headers, cookies);
        } else {
            // Try requested Uri locally first, or fallback to media server
            if (attemptDataSource(isCurrent, srcId, resolver, uri)) {
                return;
            }
            handleDataSource(isCurrent, srcId, uri.toString(), headers, cookies);
        }
    }

    private boolean attemptDataSource(
            boolean isCurrent, long srcId, ContentResolver resolver, Uri uri) {
        try (AssetFileDescriptor afd = resolver.openAssetFileDescriptor(uri, "r")) {
            if (afd.getDeclaredLength() < 0) {
                handleDataSource(isCurrent,
                                 srcId,
                                 afd.getFileDescriptor(),
                                 0,
                                 DataSourceDesc.LONG_MAX);
            } else {
                handleDataSource(isCurrent,
                                 srcId,
                                 afd.getFileDescriptor(),
                                 afd.getStartOffset(),
                                 afd.getDeclaredLength());
            }
            return true;
        } catch (NullPointerException | SecurityException | IOException ex) {
            Log.w(TAG, "Couldn't open " + uri + ": " + ex);
            return false;
        }
    }

    private void handleDataSource(
            boolean isCurrent, long srcId,
            String path, Map<String, String> headers, List<HttpCookie> cookies)
            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);
    }

    private void handleDataSource(boolean isCurrent, long srcId,
            String path, String[] keys, String[] values, List<HttpCookie> cookies)
            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
            nativeHandleDataSourceUrl(
                isCurrent,
                srcId,
                Media2HTTPService.createHTTPService(path, cookies),
                path,
                keys,
                values);
            return;
        }

        final File file = new File(path);
        if (file.exists()) {
            FileInputStream is = new FileInputStream(file);
            FileDescriptor fd = is.getFD();
            handleDataSource(isCurrent, srcId, fd, 0, DataSourceDesc.LONG_MAX);
            is.close();
        } else {
            throw new IOException("handleDataSource failed.");
        }
    }

    private native void nativeHandleDataSourceUrl(
            boolean isCurrent, long srcId,
            Media2HTTPService httpService, String path, String[] keys, String[] values)
            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,
            FileDescriptor fd, long offset, long length) throws IOException {
        nativeHandleDataSourceFD(isCurrent, srcId, fd, offset, length);
    }

    private native void nativeHandleDataSourceFD(boolean isCurrent, long srcId,
            FileDescriptor fd, long offset, long length) throws IOException;

    /**
     * @throws IllegalStateException if it is called in an invalid state
     * @throws IllegalArgumentException if dataSource is not a valid Media2DataSource
     */
    private void handleDataSource(boolean isCurrent, long srcId, Media2DataSource dataSource) {
        nativeHandleDataSourceCallback(isCurrent, srcId, dataSource);
    }

    private native void nativeHandleDataSourceCallback(
            boolean isCurrent, long srcId, Media2DataSource dataSource);

    // This function shall be called with |mSrcLock| acquired.
    private void prepareNextDataSource_l() {
        if (mNextDSDs == null || mNextDSDs.isEmpty()
                || mNextSourceState != NEXT_SOURCE_STATE_INIT) {
            // There is no next source or it's in preparing or prepared state.
            return;
        }

        try {
            mNextSourceState = NEXT_SOURCE_STATE_PREPARING;
            handleDataSource(false /* isCurrent */, mNextDSDs.get(0), mNextSrcId);
        } catch (Exception e) {
            Message msg2 = mEventHandler.obtainMessage(
                    MEDIA_ERROR, MEDIA_ERROR_UNKNOWN, MEDIA_ERROR_UNSUPPORTED, null);
            final long nextSrcId = mNextSrcId;
            mEventHandler.post(new Runnable() {
                @Override
                public void run() {
                    mEventHandler.handleMessage(msg2, nextSrcId);
                }
            });
        }
    }

    // This function shall be called with |mSrcLock| acquired.
    private void playNextDataSource_l() {
        if (mNextDSDs == null || mNextDSDs.isEmpty()) {
            return;
        }

        if (mNextSourceState == NEXT_SOURCE_STATE_PREPARED) {
            // Switch to next source only when it's in prepared state.
            mCurrentDSD = mNextDSDs.get(0);
            mCurrentSrcId = mNextSrcId;
            mBufferedPercentageCurrent.set(mBufferedPercentageNext.get());
            mNextDSDs.remove(0);
            mNextSrcId = mSrcIdGenerator++;  // make it different from mCurrentSrcId
            mBufferedPercentageNext.set(0);
            mNextSourceState = NEXT_SOURCE_STATE_INIT;
            mNextSourcePlayPending = false;

            long srcId = mCurrentSrcId;
            try {
                nativePlayNextDataSource(srcId);
            } catch (Exception e) {
                Message msg2 = mEventHandler.obtainMessage(
                        MEDIA_ERROR, MEDIA_ERROR_UNKNOWN, MEDIA_ERROR_UNSUPPORTED, null);
                mEventHandler.post(new Runnable() {
                    @Override
                    public void run() {
                        mEventHandler.handleMessage(msg2, srcId);
                    }
                });
            }

            // Wait for MEDIA2_INFO_STARTED_AS_NEXT to prepare next source.
        } else {
            if (mNextSourceState == NEXT_SOURCE_STATE_INIT) {
                prepareNextDataSource_l();
            }
            mNextSourcePlayPending = true;
        }
    }

    private native void nativePlayNextDataSource(long srcId);


    private int getAudioStreamType() {
        if (mStreamType == AudioManager.USE_DEFAULT_STREAM_TYPE) {
            mStreamType = _getAudioStreamType();
        }
        return mStreamType;
    }

    private native int _getAudioStreamType() throws IllegalStateException;

    /**
     * Stops playback after playback has been started or paused.
     *
     * @throws IllegalStateException if the internal player engine has not been
     * initialized.
     * #hide
     */
    @Override
    public void stop() {
        stayAwake(false);
        _stop();
    }

    private native void _stop() throws IllegalStateException;

    //--------------------------------------------------------------------------
    // 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.
     */
    @Override
    public boolean setPreferredDevice(AudioDeviceInfo deviceInfo) {
        if (deviceInfo != null && !deviceInfo.isSink()) {
            return false;
        }
        int preferredDeviceId = deviceInfo != null ? deviceInfo.getId() : 0;
        boolean status = native_setOutputDevice(preferredDeviceId);
        if (status == true) {
            synchronized (this) {
                mPreferredDevice = deviceInfo;
            }
        }
        return status;
    }

    /**
     * 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 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 AudioDeviceInfo getRoutedDevice() {
        int deviceId = native_getRoutedDeviceId();
        if (deviceId == 0) {
            return null;
        }
        AudioDeviceInfo[] devices =
                AudioManager.getDevicesStatic(AudioManager.GET_DEVICES_OUTPUTS);
        for (int i = 0; i < devices.length; i++) {
            if (devices[i].getId() == deviceId) {
                return devices[i];
            }
        }
        return null;
    }

    /*
     * Call BEFORE adding a routing callback handler or AFTER removing a routing callback handler.
     */
    @GuardedBy("mRoutingChangeListeners")
    private void enableNativeRoutingCallbacksLocked(boolean enabled) {
        if (mRoutingChangeListeners.size() == 0) {
            native_enableDeviceCallback(enabled);
        }
    }

    /**
     * The list of AudioRouting.OnRoutingChangedListener interfaces added (with
     * {@link #addOnRoutingChangedListener(android.media.AudioRouting.OnRoutingChangedListener, Handler)}
     * by an app to receive (re)routing notifications.
     */
    @GuardedBy("mRoutingChangeListeners")
    private ArrayMap<AudioRouting.OnRoutingChangedListener,
            NativeRoutingEventHandlerDelegate> mRoutingChangeListeners = new ArrayMap<>();

    /**
     * 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.
     */
    @Override
    public void addOnRoutingChangedListener(AudioRouting.OnRoutingChangedListener listener,
            Handler handler) {
        synchronized (mRoutingChangeListeners) {
            if (listener != null && !mRoutingChangeListeners.containsKey(listener)) {
                enableNativeRoutingCallbacksLocked(true);
                mRoutingChangeListeners.put(
                        listener, new NativeRoutingEventHandlerDelegate(this, listener,
                                handler != null ? handler : mEventHandler));
            }
        }
    }

    /**
     * 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.
     */
    @Override
    public void removeOnRoutingChangedListener(AudioRouting.OnRoutingChangedListener listener) {
        synchronized (mRoutingChangeListeners) {
            if (mRoutingChangeListeners.containsKey(listener)) {
                mRoutingChangeListeners.remove(listener);
                enableNativeRoutingCallbacksLocked(false);
            }
        }
    }

    private native final boolean native_setOutputDevice(int deviceId);
    private native final int native_getRoutedDeviceId();
    private native final void native_enableDeviceCallback(boolean enabled);

    /**
     * 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 combination of {@link android.os.PowerManager} wake flags.
     * 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 context the Context to use
     * @param mode    the power/wake mode to set
     * @see android.os.PowerManager
     * @hide
     */
    @Override
    public void setWakeMode(Context context, int mode) {
        boolean washeld = false;

        /* Disable persistant wakelocks in media player based on property */
        if (SystemProperties.getBoolean("audio.offload.ignore_setawake", false) == true) {
            Log.w(TAG, "IGNORING setWakeMode " + mode);
            return;
        }

        if (mWakeLock != null) {
            if (mWakeLock.isHeld()) {
                washeld = true;
                mWakeLock.release();
            }
            mWakeLock = null;
        }

        PowerManager pm = (PowerManager)context.getSystemService(Context.POWER_SERVICE);
        mWakeLock = pm.newWakeLock(mode|PowerManager.ON_AFTER_RELEASE, MediaPlayer2Impl.class.getName());
        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 #setWakeMode} 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.
     * @hide
     */
    @Override
    public void setScreenOnWhilePlaying(boolean screenOn) {
        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);
        }
    }

    /**
     * Returns the width of the video.
     *
     * @return the width of the video, or 0 if there is no video,
     * no display surface was set, or the width has not been determined
     * yet. The {@code MediaPlayer2EventCallback} can be registered via
     * {@link #setMediaPlayer2EventCallback(Executor, MediaPlayer2EventCallback)} to provide a
     * notification {@code MediaPlayer2EventCallback.onVideoSizeChanged} when the width
     * is available.
     */
    @Override
    public native int getVideoWidth();

    /**
     * Returns the height of the video.
     *
     * @return the height of the video, or 0 if there is no video,
     * no display surface was set, or the height has not been determined
     * yet. The {@code MediaPlayer2EventCallback} can be registered via
     * {@link #setMediaPlayer2EventCallback(Executor, MediaPlayer2EventCallback)} to provide a
     * notification {@code MediaPlayer2EventCallback.onVideoSizeChanged} when the height
     * is available.
     */
    @Override
    public native int getVideoHeight();

    /**
     * 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.
     */
    @Override
    public PersistableBundle getMetrics() {
        PersistableBundle bundle = native_getMetrics();
        return bundle;
    }

    private native PersistableBundle native_getMetrics();

    /**
     * Checks whether the MediaPlayer2 is playing.
     *
     * @return true if currently playing, false otherwise
     * @throws IllegalStateException if the internal player engine has not been
     * initialized or has been released.
     * @hide
     */
    @Override
    public native boolean isPlaying();

    @Override
    public @MediaPlayer2State int getMediaPlayer2State() {
        return native_getMediaPlayer2State();
    }

    private native int native_getMediaPlayer2State();

    /**
     * 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.
     * @hide
     */
    @Override
    @NonNull
    public 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.
     *
     * @throws IllegalStateException if the internal player engine has not been
     * initialized or has been released, or {@code setDataSource} has not been called.
     * @throws IllegalArgumentException if params is invalid or not supported.
     * @hide
     */
    @Override
    public void setBufferingParams(@NonNull BufferingParams params) {
        addTask(new Task(CALL_COMPLETED_SET_BUFFERING_PARAMS, false) {
            @Override
            void process() {
                Preconditions.checkNotNull(params, "the BufferingParams cannot be null");
                _setBufferingParams(params);
            }
        });
    }

    private native void _setBufferingParams(@NonNull BufferingParams params);

    /**
     * Sets playback rate and audio mode.
     *
     * @param rate the ratio between desired playback rate and normal one.
     * @param audioMode audio playback mode. Must be one of the supported
     * audio modes.
     *
     * @throws IllegalStateException if the internal player engine has not been
     * initialized.
     * @throws IllegalArgumentException if audioMode is not supported.
     *
     * @hide
     */
    @Override
    @NonNull
    public PlaybackParams easyPlaybackParams(float rate, @PlaybackRateAudioMode int audioMode) {
        PlaybackParams params = new PlaybackParams();
        params.allowDefaults();
        switch (audioMode) {
        case PLAYBACK_RATE_AUDIO_MODE_DEFAULT:
            params.setSpeed(rate).setPitch(1.0f);
            break;
        case PLAYBACK_RATE_AUDIO_MODE_STRETCH:
            params.setSpeed(rate).setPitch(1.0f)
                    .setAudioFallbackMode(params.AUDIO_FALLBACK_MODE_FAIL);
            break;
        case PLAYBACK_RATE_AUDIO_MODE_RESAMPLE:
            params.setSpeed(rate).setPitch(rate);
            break;
        default:
            final String msg = "Audio playback mode " + audioMode + " is not supported";
            throw new IllegalArgumentException(msg);
        }
        return params;
    }

    /**
     * Sets playback rate using {@link PlaybackParams}. The object sets its internal
     * PlaybackParams to the input, except that the object remembers previous speed
     * when input speed is zero. This allows the object to resume at previous speed
     * when play() is called. Calling it before the object is prepared does not change
     * the object state. After the object is prepared, calling it with zero speed is
     * equivalent to calling pause(). After the object is prepared, calling it with
     * non-zero speed is equivalent to calling play().
     *
     * @param params the playback params.
     *
     * @throws IllegalStateException if the internal player engine has not been
     * initialized or has been released.
     * @throws IllegalArgumentException if params is not supported.
     */
    @Override
    public void setPlaybackParams(@NonNull PlaybackParams params) {
        addTask(new Task(CALL_COMPLETED_SET_PLAYBACK_PARAMS, false) {
            @Override
            void process() {
                Preconditions.checkNotNull(params, "the PlaybackParams cannot be null");
                _setPlaybackParams(params);
            }
        });
    }

    private native void _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.
     */
    @Override
    @NonNull
    public native PlaybackParams getPlaybackParams();

    /**
     * Sets A/V sync mode.
     *
     * @param params the A/V sync params to apply
     *
     * @throws IllegalStateException if the internal player engine has not been
     * initialized.
     * @throws IllegalArgumentException if params are not supported.
     */
    @Override
    public void setSyncParams(@NonNull SyncParams params) {
        addTask(new Task(CALL_COMPLETED_SET_SYNC_PARAMS, false) {
            @Override
            void process() {
                Preconditions.checkNotNull(params, "the SyncParams cannot be null");
                _setSyncParams(params);
            }
        });
    }

    private native void _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.
     */
    @Override
    @NonNull
    public native SyncParams getSyncParams();

    /**
     * Moves the media to specified time position by considering the given mode.
     * <p>
     * When seekTo is finished, the user will be notified via OnSeekComplete supplied by the user.
     * 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.
     * Use {@link #SEEK_PREVIOUS_SYNC} if one wants to seek to a sync frame
     * that has a timestamp earlier than or the same as msec. Use
     * {@link #SEEK_NEXT_SYNC} if one wants to seek to a sync frame
     * that has a timestamp later than or the same as msec. Use
     * {@link #SEEK_CLOSEST_SYNC} if one wants to seek to a sync frame
     * that has a timestamp closest to or the same as msec. Use
     * {@link #SEEK_CLOSEST} if one wants to seek to a frame that may
     * or may not be a sync frame but is closest to or the same as msec.
     * {@link #SEEK_CLOSEST} often has larger performance overhead compared
     * to the other options if there is no sync frame located at msec.
     * @throws IllegalStateException if the internal player engine has not been
     * initialized
     * @throws IllegalArgumentException if the mode is invalid.
     */
    @Override
    public void seekTo(final long msec, @SeekMode int mode) {
        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;
                }
                _seekTo(posMs, mode);
            }
        });
    }

    private native final void _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
     */
    @Override
    @Nullable
    public MediaTimestamp getTimestamp()
    {
        try {
            // TODO: get the timestamp from native side
            return new MediaTimestamp(
                    getCurrentPosition() * 1000L,
                    System.nanoTime(),
                    isPlaying() ? getPlaybackParams().getSpeed() : 0.f);
        } catch (IllegalStateException e) {
            return null;
        }
    }

    /**
     * Gets the media metadata.
     *
     * @param update_only controls whether the full set of available
     * metadata is returned or just the set that changed since the
     * last call. See {@see #METADATA_UPDATE_ONLY} and {@see
     * #METADATA_ALL}.
     *
     * @param apply_filter if true only metadata that matches the
     * filter is returned. See {@see #APPLY_METADATA_FILTER} and {@see
     * #BYPASS_METADATA_FILTER}.
     *
     * @return The metadata, possibly empty. null if an error occured.
     // FIXME: unhide.
     * {@hide}
     */
    @Override
    public Metadata getMetadata(final boolean update_only,
                                final boolean apply_filter) {
        Parcel reply = Parcel.obtain();
        Metadata data = new Metadata();

        if (!native_getMetadata(update_only, apply_filter, reply)) {
            reply.recycle();
            return null;
        }

        // Metadata takes over the parcel, don't recycle it unless
        // there is an error.
        if (!data.parse(reply)) {
            reply.recycle();
            return null;
        }
        return data;
    }

    /**
     * Set a filter for the metadata update notification and update
     * retrieval. The caller provides 2 set of metadata keys, allowed
     * and blocked. The blocked set always takes precedence over the
     * allowed one.
     * Metadata.MATCH_ALL and Metadata.MATCH_NONE are 2 sets available as
     * shorthands to allow/block all or no metadata.
     *
     * By default, there is no filter set.
     *
     * @param allow Is the set of metadata the client is interested
     *              in receiving new notifications for.
     * @param block Is the set of metadata the client is not interested
     *              in receiving new notifications for.
     * @return The call status code.
     *
     // FIXME: unhide.
     * {@hide}
     */
    @Override
    public int setMetadataFilter(Set<Integer> allow, Set<Integer> block) {
        // Do our serialization manually instead of calling
        // Parcel.writeArray since the sets are made of the same type
        // we avoid paying the price of calling writeValue (used by
        // writeArray) which burns an extra int per element to encode
        // the type.
        Parcel request =  newRequest();

        // The parcel starts already with an interface token. There
        // are 2 filters. Each one starts with a 4bytes number to
        // store the len followed by a number of int (4 bytes as well)
        // representing the metadata type.
        int capacity = request.dataSize() + 4 * (1 + allow.size() + 1 + block.size());

        if (request.dataCapacity() < capacity) {
            request.setDataCapacity(capacity);
        }

        request.writeInt(allow.size());
        for(Integer t: allow) {
            request.writeInt(t);
        }
        request.writeInt(block.size());
        for(Integer t: block) {
            request.writeInt(t);
        }
        return native_setMetadataFilter(request);
    }

    /**
     * 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().
     */
    @Override
    public void reset() {
        mSelectedSubtitleTrackIndex = -1;
        synchronized(mOpenSubtitleSources) {
            for (final InputStream is: mOpenSubtitleSources) {
                try {
                    is.close();
                } catch (IOException e) {
                }
            }
            mOpenSubtitleSources.clear();
        }
        if (mSubtitleController != null) {
            mSubtitleController.reset();
        }
        if (mTimeProvider != null) {
            mTimeProvider.close();
            mTimeProvider = null;
        }

        synchronized (mEventCbLock) {
            mEventCallbackRecords.clear();
        }
        synchronized (mDrmEventCbLock) {
            mDrmEventCallbackRecords.clear();
        }

        stayAwake(false);
        _reset();
        // make sure none of the listeners get called anymore
        if (mEventHandler != null) {
            mEventHandler.removeCallbacksAndMessages(null);
        }

        synchronized (mIndexTrackPairs) {
            mIndexTrackPairs.clear();
            mInbandTrackIndices.clear();
        };

        resetDrmState();
    }

    private native void _reset();

    /**
     * Set up a timer for {@link #TimeProvider}. {@link #TimeProvider} will be
     * notified when the presentation time reaches (becomes greater than or equal to)
     * the value specified.
     *
     * @param mediaTimeUs presentation time to get timed event callback at
     * @hide
     */
    @Override
    public void notifyAt(long mediaTimeUs) {
        _notifyAt(mediaTimeUs);
    }

    private native void _notifyAt(long mediaTimeUs);

    // Keep KEY_PARAMETER_* in sync with include/media/mediaplayer2.h
    private final static int KEY_PARAMETER_AUDIO_ATTRIBUTES = 1400;
    /**
     * Sets the parameter indicated by key.
     * @param key key indicates the parameter to be set.
     * @param value value of the parameter to be set.
     * @return true if the parameter is set successfully, false otherwise
     */
    private native boolean setParameter(int key, Parcel value);

    private native Parcel getParameter(int key);


    /**
     * Checks whether the MediaPlayer2 is looping or non-looping.
     *
     * @return true if the MediaPlayer2 is currently looping, false otherwise
     * @hide
     */
    @Override
    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 before one of the overloaded <code> setDataSource </code> methods.
     * @throws IllegalStateException if it is called in an invalid state
     * @throws IllegalArgumentException if the sessionId is invalid.
     */
    @Override
    public void setAudioSessionId(int sessionId) {
        addTask(new Task(CALL_COMPLETED_SET_AUDIO_SESSION_ID, false) {
            @Override
            void process() {
                _setAudioSessionId(sessionId);
            }
        });
    }

    private native void _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.
     */
    @Override
    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
     */
    @Override
    public void attachAuxEffect(int effectId) {
        addTask(new Task(CALL_COMPLETED_ATTACH_AUX_EFFECT, false) {
            @Override
            void process() {
                _attachAuxEffect(effectId);
            }
        });
    }

    private native void _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
     */
    @Override
    public void setAuxEffectSendLevel(float level) {
        addTask(new Task(CALL_COMPLETED_SET_AUX_EFFECT_SEND_LEVEL, false) {
            @Override
            void process() {
                _setAuxEffectSendLevel(level);
            }
        });
    }

    private native void _setAuxEffectSendLevel(float level);

    /*
     * @param request Parcel destinated to the media player.
     * @param reply[out] Parcel that will contain the reply.
     * @return The status code.
     */
    private native final int native_invoke(Parcel request, Parcel reply);


    /*
     * @param update_only If true fetch only the set of metadata that have
     *                    changed since the last invocation of getMetadata.
     *                    The set is built using the unfiltered
     *                    notifications the native player sent to the
     *                    MediaPlayer2Manager during that period of
     *                    time. If false, all the metadatas are considered.
     * @param apply_filter  If true, once the metadata set has been built based on
     *                     the value update_only, the current filter is applied.
     * @param reply[out] On return contains the serialized
     *                   metadata. Valid only if the call was successful.
     * @return The status code.
     */
    private native final boolean native_getMetadata(boolean update_only,
                                                    boolean apply_filter,
                                                    Parcel reply);

    /*
     * @param request Parcel with the 2 serialized lists of allowed
     *                metadata types followed by the one to be
     *                dropped. Each list starts with an integer
     *                indicating the number of metadata type elements.
     * @return The status code.
     */
    private native final int native_setMetadataFilter(Parcel request);

    private static native final void native_init();
    private native final void native_setup(Object mediaplayer2_this);
    private native final void native_finalize();

    private static native final void native_stream_event_onTearDown(
            long nativeCallbackPtr, long userDataPtr);
    private static native final void native_stream_event_onStreamPresentationEnd(
            long nativeCallbackPtr, long userDataPtr);
    private static native final void native_stream_event_onStreamDataRequest(
            long jAudioTrackPtr, long nativeCallbackPtr, long userDataPtr);

    /**
     * Class for MediaPlayer2 to return each audio/video/subtitle track's metadata.
     *
     * @see android.media.MediaPlayer2#getTrackInfo
     */
    public static final class TrackInfoImpl extends TrackInfo {
        /**
         * Gets the track type.
         * @return TrackType which indicates if the track is video, audio, timed text.
         */
        @Override
        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.
         */
        @Override
        public 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.
         */
        @Override
        public MediaFormat getFormat() {
            if (mTrackType == MEDIA_TRACK_TYPE_TIMEDTEXT
                    || mTrackType == MEDIA_TRACK_TYPE_SUBTITLE) {
                return mFormat;
            }
            return null;
        }

        final int mTrackType;
        final MediaFormat mFormat;

        TrackInfoImpl(Parcel in) {
            mTrackType = in.readInt();
            // TODO: parcel in the full MediaFormat; currently we are using createSubtitleFormat
            // even for audio/video tracks, meaning we only set the mime and language.
            String mime = in.readString();
            String language = in.readString();
            mFormat = MediaFormat.createSubtitleFormat(mime, language);

            if (mTrackType == MEDIA_TRACK_TYPE_SUBTITLE) {
                mFormat.setInteger(MediaFormat.KEY_IS_AUTOSELECT, in.readInt());
                mFormat.setInteger(MediaFormat.KEY_IS_DEFAULT, in.readInt());
                mFormat.setInteger(MediaFormat.KEY_IS_FORCED_SUBTITLE, in.readInt());
            }
        }

        /** @hide */
        TrackInfoImpl(int type, MediaFormat format) {
            mTrackType = type;
            mFormat = format;
        }

        /**
         * Flatten this object in to a Parcel.
         *
         * @param dest The Parcel in which the object should be written.
         * @param flags Additional flags about how the object should be written.
         * May be 0 or {@link android.os.Parcelable#PARCELABLE_WRITE_RETURN_VALUE}.
         */
        /* package private */ void writeToParcel(Parcel dest, int flags) {
            dest.writeInt(mTrackType);
            dest.writeString(getLanguage());

            if (mTrackType == MEDIA_TRACK_TYPE_SUBTITLE) {
                dest.writeString(mFormat.getString(MediaFormat.KEY_MIME));
                dest.writeInt(mFormat.getInteger(MediaFormat.KEY_IS_AUTOSELECT));
                dest.writeInt(mFormat.getInteger(MediaFormat.KEY_IS_DEFAULT));
                dest.writeInt(mFormat.getInteger(MediaFormat.KEY_IS_FORCED_SUBTITLE));
            }
        }

        @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();
        }

        /**
         * Used to read a TrackInfoImpl from a Parcel.
         */
        /* package private */ static final Parcelable.Creator<TrackInfoImpl> CREATOR
                = new Parcelable.Creator<TrackInfoImpl>() {
                    @Override
                    public TrackInfoImpl createFromParcel(Parcel in) {
                        return new TrackInfoImpl(in);
                    }

                    @Override
                    public TrackInfoImpl[] newArray(int size) {
                        return new TrackInfoImpl[size];
                    }
                };

    };

    // We would like domain specific classes with more informative names than the `first` and `second`
    // in generic Pair, but we would also like to avoid creating new/trivial classes. As a compromise
    // we document the meanings of `first` and `second` here:
    //
    // Pair.first - inband track index; non-null iff representing an inband track.
    // Pair.second - a SubtitleTrack registered with mSubtitleController; non-null iff representing
    //               an inband subtitle track or any out-of-band track (subtitle or timedtext).
    private Vector<Pair<Integer, SubtitleTrack>> mIndexTrackPairs = new Vector<>();
    private BitSet mInbandTrackIndices = new BitSet();

    /**
     * Returns a List of track information.
     *
     * @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.
     */
    @Override
    public List<TrackInfo> getTrackInfo() {
        TrackInfoImpl trackInfo[] = getInbandTrackInfoImpl();
        // add out-of-band tracks
        synchronized (mIndexTrackPairs) {
            TrackInfoImpl allTrackInfo[] = new TrackInfoImpl[mIndexTrackPairs.size()];
            for (int i = 0; i < allTrackInfo.length; i++) {
                Pair<Integer, SubtitleTrack> p = mIndexTrackPairs.get(i);
                if (p.first != null) {
                    // inband track
                    allTrackInfo[i] = trackInfo[p.first];
                } else {
                    SubtitleTrack track = p.second;
                    allTrackInfo[i] = new TrackInfoImpl(track.getTrackType(), track.getFormat());
                }
            }
            return Arrays.asList(allTrackInfo);
        }
    }

    private TrackInfoImpl[] getInbandTrackInfoImpl() throws IllegalStateException {
        Parcel request = Parcel.obtain();
        Parcel reply = Parcel.obtain();
        try {
            request.writeInt(INVOKE_ID_GET_TRACK_INFO);
            invoke(request, reply);
            TrackInfoImpl trackInfo[] = reply.createTypedArray(TrackInfoImpl.CREATOR);
            return trackInfo;
        } finally {
            request.recycle();
            reply.recycle();
        }
    }

    /*
     * A helper function to check if the mime type is supported by media framework.
     */
    private static boolean availableMimeTypeForExternalSource(String mimeType) {
        if (MEDIA_MIMETYPE_TEXT_SUBRIP.equals(mimeType)) {
            return true;
        }
        return false;
    }

    private SubtitleController mSubtitleController;

    /** @hide */
    @Override
    public void setSubtitleAnchor(
            SubtitleController controller,
            SubtitleController.Anchor anchor) {
        // TODO: create SubtitleController in MediaPlayer2
        mSubtitleController = controller;
        mSubtitleController.setAnchor(anchor);
    }

    /**
     * The private version of setSubtitleAnchor is used internally to set mSubtitleController if
     * necessary when clients don't provide their own SubtitleControllers using the public version
     * {@link #setSubtitleAnchor(SubtitleController, Anchor)} (e.g. {@link VideoView} provides one).
     */
    private synchronized void setSubtitleAnchor() {
        if ((mSubtitleController == null) && (ActivityThread.currentApplication() != null)) {
            final HandlerThread thread = new HandlerThread("SetSubtitleAnchorThread");
            thread.start();
            Handler handler = new Handler(thread.getLooper());
            handler.post(new Runnable() {
                @Override
                public void run() {
                    Context context = ActivityThread.currentApplication();
                    mSubtitleController = new SubtitleController(context, mTimeProvider, MediaPlayer2Impl.this);
                    mSubtitleController.setAnchor(new Anchor() {
                        @Override
                        public void setSubtitleWidget(RenderingWidget subtitleWidget) {
                        }

                        @Override
                        public Looper getSubtitleLooper() {
                            return Looper.getMainLooper();
                        }
                    });
                    thread.getLooper().quitSafely();
                }
            });
            try {
                thread.join();
            } catch (InterruptedException e) {
                Thread.currentThread().interrupt();
                Log.w(TAG, "failed to join SetSubtitleAnchorThread");
            }
        }
    }

    private int mSelectedSubtitleTrackIndex = -1;
    private Vector<InputStream> mOpenSubtitleSources;

    private OnSubtitleDataListener mSubtitleDataListener = new OnSubtitleDataListener() {
        @Override
        public void onSubtitleData(MediaPlayer2 mp, SubtitleData data) {
            int index = data.getTrackIndex();
            synchronized (mIndexTrackPairs) {
                for (Pair<Integer, SubtitleTrack> p : mIndexTrackPairs) {
                    if (p.first != null && p.first == index && p.second != null) {
                        // inband subtitle track that owns data
                        SubtitleTrack track = p.second;
                        track.onData(data);
                    }
                }
            }
        }
    };

    /** @hide */
    @Override
    public void onSubtitleTrackSelected(SubtitleTrack track) {
        if (mSelectedSubtitleTrackIndex >= 0) {
            try {
                selectOrDeselectInbandTrack(mSelectedSubtitleTrackIndex, false);
            } catch (IllegalStateException e) {
            }
            mSelectedSubtitleTrackIndex = -1;
        }
        setOnSubtitleDataListener(null);
        if (track == null) {
            return;
        }

        synchronized (mIndexTrackPairs) {
            for (Pair<Integer, SubtitleTrack> p : mIndexTrackPairs) {
                if (p.first != null && p.second == track) {
                    // inband subtitle track that is selected
                    mSelectedSubtitleTrackIndex = p.first;
                    break;
                }
            }
        }

        if (mSelectedSubtitleTrackIndex >= 0) {
            try {
                selectOrDeselectInbandTrack(mSelectedSubtitleTrackIndex, true);
            } catch (IllegalStateException e) {
            }
            setOnSubtitleDataListener(mSubtitleDataListener);
        }
        // no need to select out-of-band tracks
    }

    /** @hide */
    @Override
    public void addSubtitleSource(InputStream is, MediaFormat format)
            throws IllegalStateException
    {
        final InputStream fIs = is;
        final MediaFormat fFormat = format;

        if (is != null) {
            // Ensure all input streams are closed.  It is also a handy
            // way to implement timeouts in the future.
            synchronized(mOpenSubtitleSources) {
                mOpenSubtitleSources.add(is);
            }
        } else {
            Log.w(TAG, "addSubtitleSource called with null InputStream");
        }

        getMediaTimeProvider();

        // process each subtitle in its own thread
        final HandlerThread thread = new HandlerThread("SubtitleReadThread",
              Process.THREAD_PRIORITY_BACKGROUND + Process.THREAD_PRIORITY_MORE_FAVORABLE);
        thread.start();
        Handler handler = new Handler(thread.getLooper());
        handler.post(new Runnable() {
            private int addTrack() {
                if (fIs == null || mSubtitleController == null) {
                    return MEDIA_INFO_UNSUPPORTED_SUBTITLE;
                }

                SubtitleTrack track = mSubtitleController.addTrack(fFormat);
                if (track == null) {
                    return MEDIA_INFO_UNSUPPORTED_SUBTITLE;
                }

                // TODO: do the conversion in the subtitle track
                Scanner scanner = new Scanner(fIs, "UTF-8");
                String contents = scanner.useDelimiter("\\A").next();
                synchronized(mOpenSubtitleSources) {
                    mOpenSubtitleSources.remove(fIs);
                }
                scanner.close();
                synchronized (mIndexTrackPairs) {
                    mIndexTrackPairs.add(Pair.<Integer, SubtitleTrack>create(null, track));
                }
                Handler h = mTimeProvider.mEventHandler;
                int what = TimeProvider.NOTIFY;
                int arg1 = TimeProvider.NOTIFY_TRACK_DATA;
                Pair<SubtitleTrack, byte[]> trackData = Pair.create(track, contents.getBytes());
                Message m = h.obtainMessage(what, arg1, 0, trackData);
                h.sendMessage(m);
                return MEDIA_INFO_EXTERNAL_METADATA_UPDATE;
            }

            public void run() {
                int res = addTrack();
                if (mEventHandler != null) {
                    Message m = mEventHandler.obtainMessage(MEDIA_INFO, res, 0, null);
                    mEventHandler.sendMessage(m);
                }
                thread.getLooper().quitSafely();
            }
        });
    }

    private void scanInternalSubtitleTracks() {
        setSubtitleAnchor();

        populateInbandTracks();

        if (mSubtitleController != null) {
            mSubtitleController.selectDefaultTrack();
        }
    }

    private void populateInbandTracks() {
        TrackInfoImpl[] tracks = getInbandTrackInfoImpl();
        synchronized (mIndexTrackPairs) {
            for (int i = 0; i < tracks.length; i++) {
                if (mInbandTrackIndices.get(i)) {
                    continue;
                } else {
                    mInbandTrackIndices.set(i);
                }

                // newly appeared inband track
                if (tracks[i].getTrackType() == TrackInfo.MEDIA_TRACK_TYPE_SUBTITLE) {
                    SubtitleTrack track = mSubtitleController.addTrack(
                            tracks[i].getFormat());
                    mIndexTrackPairs.add(Pair.create(i, track));
                } else {
                    mIndexTrackPairs.add(Pair.<Integer, SubtitleTrack>create(i, null));
                }
            }
        }
    }

    /* TODO: Limit the total number of external timed text source to a reasonable number.
     */
    /**
     * Adds an external timed text source file.
     *
     * Currently supported format is SubRip with the file extension .srt, case insensitive.
     * Note that a single external timed text source may contain multiple tracks in it.
     * One can find the total number of available tracks using {@link #getTrackInfo()} to see what
     * additional tracks become available after this method call.
     *
     * @param path The file path of external timed text source file.
     * @param mimeType The mime type of the file. Must be one of the mime types listed above.
     * @throws IOException if the file cannot be accessed or is corrupted.
     * @throws IllegalArgumentException if the mimeType is not supported.
     * @throws IllegalStateException if called in an invalid state.
     * @hide
     */
    @Override
    public void addTimedTextSource(String path, String mimeType)
            throws IOException {
        if (!availableMimeTypeForExternalSource(mimeType)) {
            final String msg = "Illegal mimeType for timed text source: " + mimeType;
            throw new IllegalArgumentException(msg);
        }

        File file = new File(path);
        if (file.exists()) {
            FileInputStream is = new FileInputStream(file);
            FileDescriptor fd = is.getFD();
            addTimedTextSource(fd, mimeType);
            is.close();
        } else {
            // We do not support the case where the path is not a file.
            throw new IOException(path);
        }
    }


    /**
     * Adds an external timed text source file (Uri).
     *
     * Currently supported format is SubRip with the file extension .srt, case insensitive.
     * Note that a single external timed text source may contain multiple tracks in it.
     * One can find the total number of available tracks using {@link #getTrackInfo()} to see what
     * additional tracks become available after this method call.
     *
     * @param context the Context to use when resolving the Uri
     * @param uri the Content URI of the data you want to play
     * @param mimeType The mime type of the file. Must be one of the mime types listed above.
     * @throws IOException if the file cannot be accessed or is corrupted.
     * @throws IllegalArgumentException if the mimeType is not supported.
     * @throws IllegalStateException if called in an invalid state.
     * @hide
     */
    @Override
    public void addTimedTextSource(Context context, Uri uri, String mimeType)
            throws IOException {
        String scheme = uri.getScheme();
        if(scheme == null || scheme.equals("file")) {
            addTimedTextSource(uri.getPath(), mimeType);
            return;
        }

        AssetFileDescriptor fd = null;
        try {
            ContentResolver resolver = context.getContentResolver();
            fd = resolver.openAssetFileDescriptor(uri, "r");
            if (fd == null) {
                return;
            }
            addTimedTextSource(fd.getFileDescriptor(), mimeType);
            return;
        } catch (SecurityException ex) {
        } catch (IOException ex) {
        } finally {
            if (fd != null) {
                fd.close();
            }
        }
    }

    /**
     * Adds an external timed text source file (FileDescriptor).
     *
     * It is the caller's responsibility to close the file descriptor.
     * It is safe to do so as soon as this call returns.
     *
     * Currently supported format is SubRip. Note that a single external timed text source may
     * contain multiple tracks in it. One can find the total number of available tracks
     * using {@link #getTrackInfo()} to see what additional tracks become available
     * after this method call.
     *
     * @param fd the FileDescriptor for the file you want to play
     * @param mimeType The mime type of the file. Must be one of the mime types listed above.
     * @throws IllegalArgumentException if the mimeType is not supported.
     * @throws IllegalStateException if called in an invalid state.
     * @hide
     */
    @Override
    public void addTimedTextSource(FileDescriptor fd, String mimeType) {
        // intentionally less than LONG_MAX
        addTimedTextSource(fd, 0, 0x7ffffffffffffffL, mimeType);
    }

    /**
     * Adds an external timed text file (FileDescriptor).
     *
     * It is the caller's responsibility to close the file descriptor.
     * It is safe to do so as soon as this call returns.
     *
     * Currently supported format is SubRip. Note that a single external timed text source may
     * contain multiple tracks in it. One can find the total number of available tracks
     * using {@link #getTrackInfo()} to see what additional tracks become available
     * after this method call.
     *
     * @param fd the FileDescriptor for the file you want to play
     * @param offset the offset into the file where the data to be played starts, in bytes
     * @param length the length in bytes of the data to be played
     * @param mime The mime type of the file. Must be one of the mime types listed above.
     * @throws IllegalArgumentException if the mimeType is not supported.
     * @throws IllegalStateException if called in an invalid state.
     * @hide
     */
    @Override
    public void addTimedTextSource(FileDescriptor fd, long offset, long length, String mime) {
        if (!availableMimeTypeForExternalSource(mime)) {
            throw new IllegalArgumentException("Illegal mimeType for timed text source: " + mime);
        }

        final FileDescriptor dupedFd;
        try {
            dupedFd = Os.dup(fd);
        } catch (ErrnoException ex) {
            Log.e(TAG, ex.getMessage(), ex);
            throw new RuntimeException(ex);
        }

        final MediaFormat fFormat = new MediaFormat();
        fFormat.setString(MediaFormat.KEY_MIME, mime);
        fFormat.setInteger(MediaFormat.KEY_IS_TIMED_TEXT, 1);

        // A MediaPlayer2 created by a VideoView should already have its mSubtitleController set.
        if (mSubtitleController == null) {
            setSubtitleAnchor();
        }

        if (!mSubtitleController.hasRendererFor(fFormat)) {
            // test and add not atomic
            Context context = ActivityThread.currentApplication();
            mSubtitleController.registerRenderer(new SRTRenderer(context, mEventHandler));
        }
        final SubtitleTrack track = mSubtitleController.addTrack(fFormat);
        synchronized (mIndexTrackPairs) {
            mIndexTrackPairs.add(Pair.<Integer, SubtitleTrack>create(null, track));
        }

        getMediaTimeProvider();

        final long offset2 = offset;
        final long length2 = length;
        final HandlerThread thread = new HandlerThread(
                "TimedTextReadThread",
                Process.THREAD_PRIORITY_BACKGROUND + Process.THREAD_PRIORITY_MORE_FAVORABLE);
        thread.start();
        Handler handler = new Handler(thread.getLooper());
        handler.post(new Runnable() {
            private int addTrack() {
                final ByteArrayOutputStream bos = new ByteArrayOutputStream();
                try {
                    Os.lseek(dupedFd, offset2, OsConstants.SEEK_SET);
                    byte[] buffer = new byte[4096];
                    for (long total = 0; total < length2;) {
                        int bytesToRead = (int) Math.min(buffer.length, length2 - total);
                        int bytes = IoBridge.read(dupedFd, buffer, 0, bytesToRead);
                        if (bytes < 0) {
                            break;
                        } else {
                            bos.write(buffer, 0, bytes);
                            total += bytes;
                        }
                    }
                    Handler h = mTimeProvider.mEventHandler;
                    int what = TimeProvider.NOTIFY;
                    int arg1 = TimeProvider.NOTIFY_TRACK_DATA;
                    Pair<SubtitleTrack, byte[]> trackData = Pair.create(track, bos.toByteArray());
                    Message m = h.obtainMessage(what, arg1, 0, trackData);
                    h.sendMessage(m);
                    return MEDIA_INFO_EXTERNAL_METADATA_UPDATE;
                } catch (Exception e) {
                    Log.e(TAG, e.getMessage(), e);
                    return MEDIA_INFO_TIMED_TEXT_ERROR;
                } finally {
                    try {
                        Os.close(dupedFd);
                    } catch (ErrnoException e) {
                        Log.e(TAG, e.getMessage(), e);
                    }
                }
            }

            public void run() {
                int res = addTrack();
                if (mEventHandler != null) {
                    Message m = mEventHandler.obtainMessage(MEDIA_INFO, res, 0, null);
                    mEventHandler.sendMessage(m);
                }
                thread.getLooper().quitSafely();
            }
        });
    }

    /**
     * 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(int)} or {@link #deselectTrack(int)}.
     *
     * @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 index of the audio, video, or subtitle track currently selected for playback;
     * a negative integer 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()}
     *
     * @see #getTrackInfo()
     * @see #selectTrack(int)
     * @see #deselectTrack(int)
     */
    @Override
    public int getSelectedTrack(int trackType) {
        if (mSubtitleController != null
                && (trackType == TrackInfo.MEDIA_TRACK_TYPE_SUBTITLE
                || trackType == TrackInfo.MEDIA_TRACK_TYPE_TIMEDTEXT)) {
            SubtitleTrack subtitleTrack = mSubtitleController.getSelectedTrack();
            if (subtitleTrack != null) {
                synchronized (mIndexTrackPairs) {
                    for (int i = 0; i < mIndexTrackPairs.size(); i++) {
                        Pair<Integer, SubtitleTrack> p = mIndexTrackPairs.get(i);
                        if (p.second == subtitleTrack && subtitleTrack.getTrackType() == trackType) {
                            return i;
                        }
                    }
                }
            }
        }

        Parcel request = Parcel.obtain();
        Parcel reply = Parcel.obtain();
        try {
            request.writeInt(INVOKE_ID_GET_SELECTED_TRACK);
            request.writeInt(trackType);
            invoke(request, reply);
            int inbandTrackIndex = reply.readInt();
            synchronized (mIndexTrackPairs) {
                for (int i = 0; i < mIndexTrackPairs.size(); i++) {
                    Pair<Integer, SubtitleTrack> p = mIndexTrackPairs.get(i);
                    if (p.first != null && p.first == inbandTrackIndex) {
                        return i;
                    }
                }
            }
            return -1;
        } finally {
            request.recycle();
            reply.recycle();
        }
    }

    /**
     * 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 index the index of the track to be selected. The valid range of the index
     * is 0..total number of track - 1. The total number of tracks as well as the type of
     * each individual track can be found by calling {@link #getTrackInfo()} method.
     * @throws IllegalStateException if called in an invalid state.
     *
     * @see android.media.MediaPlayer2#getTrackInfo
     */
    @Override
    public void selectTrack(int index) {
        addTask(new Task(CALL_COMPLETED_SELECT_TRACK, false) {
            @Override
            void process() {
                selectOrDeselectTrack(index, true /* select */);
            }
        });
    }

    /**
     * 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 index the index of the track to be deselected. The valid range of the index
     * is 0..total number of tracks - 1. The total number of tracks as well as the type of
     * each individual track can be found by calling {@link #getTrackInfo()} method.
     * @throws IllegalStateException if called in an invalid state.
     *
     * @see android.media.MediaPlayer2#getTrackInfo
     */
    @Override
    public void deselectTrack(int index) {
        addTask(new Task(CALL_COMPLETED_DESELECT_TRACK, false) {
            @Override
            void process() {
                selectOrDeselectTrack(index, false /* select */);
            }
        });
    }

    private void selectOrDeselectTrack(int index, boolean select)
            throws IllegalStateException {
        // handle subtitle track through subtitle controller
        populateInbandTracks();

        Pair<Integer,SubtitleTrack> p = null;
        try {
            p = mIndexTrackPairs.get(index);
        } catch (ArrayIndexOutOfBoundsException e) {
            // ignore bad index
            return;
        }

        SubtitleTrack track = p.second;
        if (track == null) {
            // inband (de)select
            selectOrDeselectInbandTrack(p.first, select);
            return;
        }

        if (mSubtitleController == null) {
            return;
        }

        if (!select) {
            // out-of-band deselect
            if (mSubtitleController.getSelectedTrack() == track) {
                mSubtitleController.selectTrack(null);
            } else {
                Log.w(TAG, "trying to deselect track that was not selected");
            }
            return;
        }

        // out-of-band select
        if (track.getTrackType() == TrackInfo.MEDIA_TRACK_TYPE_TIMEDTEXT) {
            int ttIndex = getSelectedTrack(TrackInfo.MEDIA_TRACK_TYPE_TIMEDTEXT);
            synchronized (mIndexTrackPairs) {
                if (ttIndex >= 0 && ttIndex < mIndexTrackPairs.size()) {
                    Pair<Integer,SubtitleTrack> p2 = mIndexTrackPairs.get(ttIndex);
                    if (p2.first != null && p2.second == null) {
                        // deselect inband counterpart
                        selectOrDeselectInbandTrack(p2.first, false);
                    }
                }
            }
        }
        mSubtitleController.selectTrack(track);
    }

    private void selectOrDeselectInbandTrack(int index, boolean select)
            throws IllegalStateException {
        Parcel request = Parcel.obtain();
        Parcel reply = Parcel.obtain();
        try {
            request.writeInt(select? INVOKE_ID_SELECT_TRACK: INVOKE_ID_DESELECT_TRACK);
            request.writeInt(index);
            invoke(request, reply);
        } finally {
            request.recycle();
            reply.recycle();
        }
    }

    // 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 void release() {
        stayAwake(false);
        updateSurfaceScreenOn();
        synchronized (mEventCbLock) {
            mEventCallbackRecords.clear();
        }
        if (mHandlerThread != null) {
            mHandlerThread.quitSafely();
            mHandlerThread = null;
        }
        if (mTimeProvider != null) {
            mTimeProvider.close();
            mTimeProvider = null;
        }
        mOnSubtitleDataListener = null;

        // Modular DRM clean up
        mOnDrmConfigHelper = null;
        synchronized (mDrmEventCbLock) {
            mDrmEventCallbackRecords.clear();
        }
        resetDrmState();

        _release();
    }

    private native void _release();

    /* 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_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 static final int MEDIA_AUDIO_ROUTING_CHANGED = 10000;

    private TimeProvider mTimeProvider;

    /** @hide */
    @Override
    public MediaTimeProvider getMediaTimeProvider() {
        if (mTimeProvider == null) {
            mTimeProvider = new TimeProvider(this);
        }
        return mTimeProvider;
    }

    private class EventHandler extends Handler {
        private MediaPlayer2Impl mMediaPlayer;

        public EventHandler(MediaPlayer2Impl 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;

            switch(msg.what) {
            case MEDIA_PREPARED:
            {
                try {
                    scanInternalSubtitleTracks();
                } catch (RuntimeException e) {
                    // send error message instead of crashing;
                    // send error message instead of inlining a call to onError
                    // to avoid code duplication.
                    Message msg2 = obtainMessage(
                            MEDIA_ERROR, MEDIA_ERROR_UNKNOWN, MEDIA_ERROR_UNSUPPORTED, null);
                    sendMessage(msg2);
                }

                final DataSourceDesc dsd;
                synchronized (mSrcLock) {
                    Log.i(TAG, "MEDIA_PREPARED: srcId=" + srcId
                            + ", currentSrcId=" + mCurrentSrcId + ", nextSrcId=" + mNextSrcId);
                    if (srcId == mCurrentSrcId) {
                        dsd = mCurrentDSD;
                        prepareNextDataSource_l();
                    } else if (mNextDSDs != null && !mNextDSDs.isEmpty()
                            && srcId == mNextSrcId) {
                        dsd = mNextDSDs.get(0);
                        mNextSourceState = NEXT_SOURCE_STATE_PREPARED;
                        if (mNextSourcePlayPending) {
                            playNextDataSource_l();
                        }
                    } else {
                        dsd = null;
                    }
                }

                if (dsd != null) {
                    synchronized (mEventCbLock) {
                        for (Pair<Executor, MediaPlayer2EventCallback> cb : mEventCallbackRecords) {
                            cb.first.execute(() -> cb.second.onInfo(
                                    mMediaPlayer, dsd, MEDIA_INFO_PREPARED, 0));
                        }
                    }
                }
                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 Parcel) {
                    // The parcel was parsed already in postEventFromNative
                    final DrmInfoImpl drmInfo;

                    synchronized (mDrmLock) {
                        if (mDrmInfoImpl != null) {
                            drmInfo = mDrmInfoImpl.makeCopy();
                        } else {
                            drmInfo = null;
                        }
                    }

                    // notifying the client outside the lock
                    if (drmInfo != null) {
                        synchronized (mEventCbLock) {
                            for (Pair<Executor, DrmEventCallback> cb : mDrmEventCallbackRecords) {
                                cb.first.execute(() -> cb.second.onDrmInfo(
                                        mMediaPlayer, mCurrentDSD, drmInfo));
                            }
                        }
                    }
                } else {
                    Log.w(TAG, "MEDIA_DRM_INFO msg.obj of unexpected type " + msg.obj);
                }
                return;
            }

            case MEDIA_PLAYBACK_COMPLETE:
            {
                final DataSourceDesc dsd = mCurrentDSD;
                synchronized (mSrcLock) {
                    if (srcId == mCurrentSrcId) {
                        Log.i(TAG, "MEDIA_PLAYBACK_COMPLETE: srcId=" + srcId
                                + ", currentSrcId=" + mCurrentSrcId + ", nextSrcId=" + mNextSrcId);
                        playNextDataSource_l();
                    }
                }

                synchronized (mEventCbLock) {
                    for (Pair<Executor, MediaPlayer2EventCallback> cb : mEventCallbackRecords) {
                        cb.first.execute(() -> cb.second.onInfo(
                                mMediaPlayer, dsd, MEDIA_INFO_PLAYBACK_COMPLETE, 0));
                    }
                }
                stayAwake(false);
                return;
            }

            case MEDIA_STOPPED:
            {
                TimeProvider timeProvider = mTimeProvider;
                if (timeProvider != null) {
                    timeProvider.onStopped();
                }
                break;
            }

            case MEDIA_STARTED:
            case MEDIA_PAUSED:
            {
                TimeProvider timeProvider = mTimeProvider;
                if (timeProvider != null) {
                    timeProvider.onPaused(msg.what == MEDIA_PAUSED);
                }
                break;
            }

            case MEDIA_BUFFERING_UPDATE:
            {
                final int percent = msg.arg1;
                synchronized (mEventCbLock) {
                    if (srcId == mCurrentSrcId) {
                        mBufferedPercentageCurrent.set(percent);
                        for (Pair<Executor, MediaPlayer2EventCallback> cb : mEventCallbackRecords) {
                            cb.first.execute(() -> cb.second.onInfo(
                                    mMediaPlayer, mCurrentDSD, MEDIA_INFO_BUFFERING_UPDATE,
                                    percent));
                        }
                    } else if (srcId == mNextSrcId && !mNextDSDs.isEmpty()) {
                        mBufferedPercentageNext.set(percent);
                        DataSourceDesc nextDSD = mNextDSDs.get(0);
                        for (Pair<Executor, MediaPlayer2EventCallback> cb : mEventCallbackRecords) {
                            cb.first.execute(() -> cb.second.onInfo(
                                    mMediaPlayer, nextDSD, MEDIA_INFO_BUFFERING_UPDATE,
                                    percent));
                        }
                    }
                }
                return;
            }

            case MEDIA_SEEK_COMPLETE:
            {
                synchronized (mTaskLock) {
                    if (mCurrentTask != null
                            && mCurrentTask.mMediaCallType == CALL_COMPLETED_SEEK_TO
                            && mCurrentTask.mNeedToWaitForEventToComplete) {
                        mCurrentTask.sendCompleteNotification(CALL_STATUS_NO_ERROR);
                        mCurrentTask = null;
                        processPendingTask_l();
                    }
                }
            }
                // fall through

            case MEDIA_SKIPPED:
            {
                TimeProvider timeProvider = mTimeProvider;
                if (timeProvider != null) {
                    timeProvider.onSeekComplete(mMediaPlayer);
                }
                return;
            }

            case MEDIA_SET_VIDEO_SIZE:
            {
                final int width = msg.arg1;
                final int height = msg.arg2;
                synchronized (mEventCbLock) {
                    for (Pair<Executor, MediaPlayer2EventCallback> cb : mEventCallbackRecords) {
                        cb.first.execute(() -> cb.second.onVideoSizeChanged(
                                mMediaPlayer, mCurrentDSD, width, height));
                    }
                }
                return;
            }

            case MEDIA_ERROR:
            {
                Log.e(TAG, "Error (" + msg.arg1 + "," + msg.arg2 + ")");
                synchronized (mEventCbLock) {
                    for (Pair<Executor, MediaPlayer2EventCallback> cb : mEventCallbackRecords) {
                        cb.first.execute(() -> cb.second.onError(
                                mMediaPlayer, mCurrentDSD, what, extra));
                        cb.first.execute(() -> cb.second.onInfo(
                                mMediaPlayer, mCurrentDSD, MEDIA_INFO_PLAYBACK_COMPLETE, 0));
                    }
                }
                stayAwake(false);
                return;
            }

            case MEDIA_INFO:
            {
                switch (msg.arg1) {
                    case MEDIA_INFO_STARTED_AS_NEXT:
                        if (srcId == mCurrentSrcId) {
                            prepareNextDataSource_l();
                        }
                        break;

                    case MEDIA_INFO_VIDEO_TRACK_LAGGING:
                        Log.i(TAG, "Info (" + msg.arg1 + "," + msg.arg2 + ")");
                        break;

                    case MEDIA_INFO_METADATA_UPDATE:
                        try {
                            scanInternalSubtitleTracks();
                        } catch (RuntimeException e) {
                            Message msg2 = obtainMessage(
                                    MEDIA_ERROR, MEDIA_ERROR_UNKNOWN, MEDIA_ERROR_UNSUPPORTED,
                                    null);
                            sendMessage(msg2);
                        }
                        // fall through

                    case MEDIA_INFO_EXTERNAL_METADATA_UPDATE:
                        msg.arg1 = MEDIA_INFO_METADATA_UPDATE;
                        // update default track selection
                        if (mSubtitleController != null) {
                            mSubtitleController.selectDefaultTrack();
                        }
                        break;

                    case MEDIA_INFO_BUFFERING_START:
                    case MEDIA_INFO_BUFFERING_END:
                        TimeProvider timeProvider = mTimeProvider;
                        if (timeProvider != null) {
                            timeProvider.onBuffering(msg.arg1 == MEDIA_INFO_BUFFERING_START);
                        }
                        break;
                }

                synchronized (mEventCbLock) {
                    for (Pair<Executor, MediaPlayer2EventCallback> cb : mEventCallbackRecords) {
                        cb.first.execute(() -> cb.second.onInfo(
                                mMediaPlayer, mCurrentDSD, what, extra));
                    }
                }
                // No real default action so far.
                return;
            }

            case MEDIA_NOTIFY_TIME:
            {
                TimeProvider timeProvider = mTimeProvider;
                if (timeProvider != null) {
                    timeProvider.onNotifyTime();
                }
                return;
            }

            case MEDIA_TIMED_TEXT:
            {
                final TimedText text;
                if (msg.obj instanceof Parcel) {
                    Parcel parcel = (Parcel)msg.obj;
                    text = new TimedText(parcel);
                    parcel.recycle();
                } else {
                    text = null;
                }

                synchronized (mEventCbLock) {
                    for (Pair<Executor, MediaPlayer2EventCallback> cb : mEventCallbackRecords) {
                        cb.first.execute(() -> cb.second.onTimedText(mMediaPlayer, mCurrentDSD, text));
                    }
                }
                return;
            }

            case MEDIA_SUBTITLE_DATA:
            {
                OnSubtitleDataListener onSubtitleDataListener = mOnSubtitleDataListener;
                if (onSubtitleDataListener == null) {
                    return;
                }
                if (msg.obj instanceof Parcel) {
                    Parcel parcel = (Parcel) msg.obj;
                    SubtitleData data = new SubtitleData(parcel);
                    parcel.recycle();
                    onSubtitleDataListener.onSubtitleData(mMediaPlayer, data);
                }
                return;
            }

            case MEDIA_META_DATA:
            {
                final TimedMetaData data;
                if (msg.obj instanceof Parcel) {
                    Parcel parcel = (Parcel) msg.obj;
                    data = TimedMetaData.createTimedMetaDataFromParcel(parcel);
                    parcel.recycle();
                } else {
                    data = null;
                }

                synchronized (mEventCbLock) {
                    for (Pair<Executor, MediaPlayer2EventCallback> cb : mEventCallbackRecords) {
                        cb.first.execute(() -> cb.second.onTimedMetaDataAvailable(
                                mMediaPlayer, mCurrentDSD, data));
                    }
                }
                return;
            }

            case MEDIA_NOP: // interface test message - ignore
            {
                break;
            }

            case MEDIA_AUDIO_ROUTING_CHANGED:
            {
                AudioManager.resetAudioPortGeneration();
                synchronized (mRoutingChangeListeners) {
                    for (NativeRoutingEventHandlerDelegate delegate
                            : mRoutingChangeListeners.values()) {
                        delegate.notifyClient();
                    }
                }
                return;
            }

            default:
            {
                Log.e(TAG, "Unknown message type " + msg.what);
                return;
            }
            }
        }
    }

    /*
     * Called from native code when an interesting event happens.  This method
     * just uses the EventHandler 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 mediaplayer2_ref, long srcId,
                                            int what, int arg1, int arg2, Object obj)
    {
        final MediaPlayer2Impl mp = (MediaPlayer2Impl)((WeakReference)mediaplayer2_ref).get();
        if (mp == null) {
            return;
        }

        switch (what) {
        case MEDIA_INFO:
            if (arg1 == MEDIA_INFO_STARTED_AS_NEXT) {
                new Thread(new Runnable() {
                    @Override
                    public void run() {
                        // this acquires the wakelock if needed, and sets the client side state
                        mp.play();
                    }
                }).start();
                Thread.yield();
            }
            break;

        case MEDIA_DRM_INFO:
            // We need to derive mDrmInfoImpl before prepare() returns so processing it here
            // before the notification is sent to EventHandler below. EventHandler 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 instanceof Parcel) {
                Parcel parcel = (Parcel)obj;
                DrmInfoImpl drmInfo = new DrmInfoImpl(parcel);
                synchronized (mp.mDrmLock) {
                    mp.mDrmInfoImpl = drmInfo;
                }
            } else {
                Log.w(TAG, "MEDIA_DRM_INFO 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().
            synchronized (mp.mDrmLock) {
                mp.mDrmInfoResolved = true;
            }
            break;

        }

        if (mp.mEventHandler != null) {
            Message m = mp.mEventHandler.obtainMessage(what, arg1, arg2, obj);

            mp.mEventHandler.post(new Runnable() {
                @Override
                public void run() {
                    mp.mEventHandler.handleMessage(m, srcId);
                }
            });
        }
    }

    private final Object mEventCbLock = new Object();
    private ArrayList<Pair<Executor, MediaPlayer2EventCallback> > mEventCallbackRecords
        = new ArrayList<Pair<Executor, MediaPlayer2EventCallback> >();

    /**
     * Register a callback to be invoked when the media source is ready
     * for playback.
     *
     * @param eventCallback the callback that will be run
     * @param executor the executor through which the callback should be invoked
     */
    @Override
    public void setMediaPlayer2EventCallback(@NonNull @CallbackExecutor Executor executor,
            @NonNull MediaPlayer2EventCallback eventCallback) {
        if (eventCallback == null) {
            throw new IllegalArgumentException("Illegal null MediaPlayer2EventCallback");
        }
        if (executor == null) {
            throw new IllegalArgumentException(
                    "Illegal null Executor for the MediaPlayer2EventCallback");
        }
        synchronized (mEventCbLock) {
            mEventCallbackRecords.add(new Pair(executor, eventCallback));
        }
    }

    /**
     * Clears the {@link MediaPlayer2EventCallback}.
     */
    @Override
    public void clearMediaPlayer2EventCallback() {
        synchronized (mEventCbLock) {
            mEventCallbackRecords.clear();
        }
    }

    /**
     * Register a callback to be invoked when a track has data available.
     *
     * @param listener the callback that will be run
     *
     * @hide
     */
    @Override
    public void setOnSubtitleDataListener(OnSubtitleDataListener listener) {
        mOnSubtitleDataListener = listener;
    }

    private OnSubtitleDataListener mOnSubtitleDataListener;


    // Modular DRM begin

    /**
     * Register a callback to be invoked for configuration of the DRM object before
     * the session is created.
     * The callback will be invoked synchronously during the execution
     * of {@link #prepareDrm(UUID uuid)}.
     *
     * @param listener the callback that will be run
     */
    @Override
    public void setOnDrmConfigHelper(OnDrmConfigHelper listener)
    {
        synchronized (mDrmLock) {
            mOnDrmConfigHelper = listener;
        } // synchronized
    }

    private OnDrmConfigHelper mOnDrmConfigHelper;

    private final Object mDrmEventCbLock = new Object();
    private ArrayList<Pair<Executor, DrmEventCallback> > mDrmEventCallbackRecords
        = new ArrayList<Pair<Executor, DrmEventCallback> >();

    /**
     * Register a callback to be invoked when the media source is ready
     * for playback.
     *
     * @param eventCallback the callback that will be run
     * @param executor the executor through which the callback should be invoked
     */
    @Override
    public void setDrmEventCallback(@NonNull @CallbackExecutor Executor executor,
            @NonNull DrmEventCallback eventCallback) {
        if (eventCallback == null) {
            throw new IllegalArgumentException("Illegal null MediaPlayer2EventCallback");
        }
        if (executor == null) {
            throw new IllegalArgumentException(
                    "Illegal null Executor for the MediaPlayer2EventCallback");
        }
        synchronized (mDrmEventCbLock) {
            mDrmEventCallbackRecords.add(new Pair(executor, eventCallback));
        }
    }

    /**
     * Clears the {@link DrmEventCallback}.
     */
    @Override
    public void clearDrmEventCallback() {
        synchronized (mDrmEventCbLock) {
            mDrmEventCallbackRecords.clear();
        }
    }


    /**
     * Retrieves the DRM Info associated with the current source
     *
     * @throws IllegalStateException if called before prepare()
     */
    @Override
    public DrmInfo getDrmInfo() {
        DrmInfoImpl drmInfo = null;

        // there is not much point if the app calls getDrmInfo within an OnDrmInfoListenet;
        // regardless below returns drmInfo anyway instead of raising an exception
        synchronized (mDrmLock) {
            if (!mDrmInfoResolved && mDrmInfoImpl == null) {
                final String msg = "The Player has not been prepared yet";
                Log.v(TAG, msg);
                throw new IllegalStateException(msg);
            }

            if (mDrmInfoImpl != null) {
                drmInfo = mDrmInfoImpl.makeCopy();
            }
        }   // synchronized

        return drmInfo;
    }


    /**
     * Prepares the DRM for the current source
     * <p>
     * If {@code OnDrmConfigHelper} is registered, it will be called during
     * preparation to allow configuration of the DRM properties before opening the
     * DRM session. Note that the callback is called synchronously in the thread that called
     * {@code prepareDrm}. It should be used only for a series of {@code getDrmPropertyString}
     * and {@code setDrmPropertyString} 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.
     * If {@code OnDrmPreparedListener} is registered, prepareDrm() runs in non-blocking
     * mode by launching the provisioning in the background and returning. The listener
     * will be called when provisioning and preparation has finished. If a
     * {@code OnDrmPreparedListener} is not registered, prepareDrm() waits till provisioning
     * and preparation has finished, i.e., runs in blocking mode.
     * <p>
     * If {@code OnDrmPreparedListener} is registered, it 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), or the thread context that will
     * execute the listener (unless the listener is registered with a handler thread).
     * <p>
     *
     * @param uuid The UUID of the crypto scheme. If not known beforehand, it can be retrieved
     * from the source through {@code getDrmInfo} or registering a {@code onDrmInfoListener}.
     *
     * @throws IllegalStateException              if called before prepare(), or the DRM was
     *                                            prepared already
     * @throws UnsupportedSchemeException         if the crypto scheme is not supported
     * @throws ResourceBusyException              if required DRM resources are in use
     * @throws ProvisioningNetworkErrorException  if provisioning is required but failed due to a
     *                                            network error
     * @throws ProvisioningServerErrorException   if provisioning is required but failed due to
     *                                            the request denied by the provisioning server
     */
    @Override
    public void prepareDrm(@NonNull UUID uuid)
            throws UnsupportedSchemeException, ResourceBusyException,
                   ProvisioningNetworkErrorException, ProvisioningServerErrorException
    {
        Log.v(TAG, "prepareDrm: uuid: " + uuid + " mOnDrmConfigHelper: " + mOnDrmConfigHelper);

        boolean allDoneWithoutProvisioning = false;

        synchronized (mDrmLock) {

            // only allowing if tied to a protected source; might relax for releasing offline keys
            if (mDrmInfoImpl == null) {
                final String msg = "prepareDrm(): Wrong usage: The player must be prepared and " +
                        "DRM info be retrieved before this call.";
                Log.e(TAG, msg);
                throw new IllegalStateException(msg);
            }

            if (mActiveDrmScheme) {
                final String msg = "prepareDrm(): Wrong usage: There is already " +
                        "an active DRM scheme with " + mDrmUUID;
                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 is 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
        if (mOnDrmConfigHelper != null)  {
            mOnDrmConfigHelper.onDrmConfig(this, mCurrentDSD);
        }

        synchronized (mDrmLock) {
            mDrmConfigAllowed = false;
            boolean earlyExit = false;

            try {
                prepareDrm_openSessionStep(uuid);

                mDrmUUID = uuid;
                mActiveDrmScheme = true;

                allDoneWithoutProvisioning = true;
            } 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;
                throw new IllegalStateException(msg);
            } catch (NotProvisionedException e) {
                Log.w(TAG, "prepareDrm: NotProvisionedException");

                // handle provisioning internally; it'll reset mPrepareDrmInProgress
                int result = HandleProvisioninig(uuid);

                // if blocking mode, we're already done;
                // if non-blocking mode, we attempted to launch background provisioning
                if (result != PREPARE_DRM_STATUS_SUCCESS) {
                    earlyExit = true;
                    String msg;

                    switch (result) {
                    case PREPARE_DRM_STATUS_PROVISIONING_NETWORK_ERROR:
                        msg = "prepareDrm: Provisioning was required but failed " +
                                "due to a network error.";
                        Log.e(TAG, msg);
                        throw new ProvisioningNetworkErrorExceptionImpl(msg);

                    case PREPARE_DRM_STATUS_PROVISIONING_SERVER_ERROR:
                        msg = "prepareDrm: Provisioning was required but the request " +
                                "was denied by the server.";
                        Log.e(TAG, msg);
                        throw new ProvisioningServerErrorExceptionImpl(msg);

                    case PREPARE_DRM_STATUS_PREPARATION_ERROR:
                    default: // default for safeguard
                        msg = "prepareDrm: Post-provisioning preparation failed.";
                        Log.e(TAG, msg);
                        throw new IllegalStateException(msg);
                    }
                }
                // nothing else to do;
                // if blocking or non-blocking, HandleProvisioninig does the re-attempt & cleanup
            } catch (Exception e) {
                Log.e(TAG, "prepareDrm: Exception " + e);
                earlyExit = true;
                throw e;
            } finally {
                if (!mDrmProvisioningInProgress) {// if early exit other than provisioning exception
                    mPrepareDrmInProgress = false;
                }
                if (earlyExit) {    // cleaning up object if didn't succeed
                    cleanDrmObj();
                }
            } // finally
        }   // synchronized


        // if finished successfully without provisioning, call the callback outside the lock
        if (allDoneWithoutProvisioning) {
            synchronized (mDrmEventCbLock) {
                for (Pair<Executor, DrmEventCallback> cb : mDrmEventCallbackRecords) {
                    cb.first.execute(() -> cb.second.onDrmPrepared(
                            this, mCurrentDSD, PREPARE_DRM_STATUS_SUCCESS));
                }
            }
        }

    }


    private native void _releaseDrm();

    /**
     * Releases the DRM session
     * <p>
     * The player has to have an active DRM session and be in stopped, or prepared
     * state before this call is made.
     * A {@code reset()} call will release the DRM session implicitly.
     *
     * @throws NoDrmSchemeException if there is no active DRM session to release
     */
    @Override
    public void releaseDrm()
            throws NoDrmSchemeException
    {
        addTask(new Task(CALL_COMPLETED_RELEASE_DRM, false) {
            @Override
            void process() throws NoDrmSchemeException {
                synchronized (mDrmLock) {
                    Log.v(TAG, "releaseDrm:");

                    if (!mActiveDrmScheme) {
                        Log.e(TAG, "releaseDrm(): No active DRM scheme to release.");
                        throw new NoDrmSchemeExceptionImpl(
                                "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
                        _releaseDrm();

                        // for cleaning client-side MediaDrm object; only called if above has succeeded
                        cleanDrmObj();

                        mActiveDrmScheme = false;
                    } 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
            }
        });
    }


    /**
     * A key request/response exchange occurs between the app and a license server
     * to obtain or release keys used to decrypt encrypted content.
     * <p>
     * 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 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}.
     *
     * @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
     */
    @Override
    @NonNull
    public MediaDrm.KeyRequest getDrmKeyRequest(@Nullable byte[] keySetId, @Nullable byte[] initData,
            @Nullable String mimeType, @MediaDrm.KeyType int keyType,
            @Nullable Map<String, String> optionalParameters)
            throws NoDrmSchemeException
    {
        Log.v(TAG, "getDrmKeyRequest: " +
                " keySetId: " + keySetId + " initData:" + initData + " mimeType: " + mimeType +
                " keyType: " + keyType + " optionalParameters: " + optionalParameters);

        synchronized (mDrmLock) {
            if (!mActiveDrmScheme) {
                Log.e(TAG, "getDrmKeyRequest NoDrmSchemeException");
                throw new NoDrmSchemeExceptionImpl(
                        "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: Unexpected provisioning error.");
            } catch (Exception e) {
                Log.w(TAG, "getDrmKeyRequest Exception " + e);
                throw e;
            }

        }   // synchronized
    }


    /**
     * A key response is received from the license server by the app, then it is
     * provided to the DRM engine plugin using provideDrmKeyResponse. 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}.
     * When the response is for a streaming or release request, null is returned.
     *
     * @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} 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
     */
    @Override
    public byte[] provideDrmKeyResponse(@Nullable byte[] keySetId, @NonNull byte[] response)
            throws NoDrmSchemeException, DeniedByServerException
    {
        Log.v(TAG, "provideDrmKeyResponse: keySetId: " + keySetId + " response: " + response);

        synchronized (mDrmLock) {

            if (!mActiveDrmScheme) {
                Log.e(TAG, "getDrmKeyRequest NoDrmSchemeException");
                throw new NoDrmSchemeExceptionImpl(
                        "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;
            }
        }   // synchronized
    }


    /**
     * Restore persisted offline keys into a new session.  keySetId identifies the
     * keys to load, obtained from a prior call to {@link #provideDrmKeyResponse}.
     *
     * @param keySetId identifies the saved key set to restore
     */
    @Override
    public void restoreDrmKeys(@NonNull byte[] keySetId)
            throws NoDrmSchemeException
    {
        addTask(new Task(CALL_COMPLETED_RESTORE_DRM_KEYS, false) {
            @Override
            void process() throws NoDrmSchemeException {
                Log.v(TAG, "restoreDrmKeys: keySetId: " + keySetId);

                synchronized (mDrmLock) {

                    if (!mActiveDrmScheme) {
                        Log.w(TAG, "restoreDrmKeys NoDrmSchemeException");
                        throw new NoDrmSchemeExceptionImpl(
                                "restoreDrmKeys: Has to set a DRM scheme first.");
                    }

                    try {
                        mDrmObj.restoreKeys(mDrmSessionId, keySetId);
                    } catch (Exception e) {
                        Log.w(TAG, "restoreKeys Exception " + e);
                        throw e;
                    }

                }   // synchronized
            }
        });
    }


    /**
     * Read a DRM engine plugin String property value, given the property name string.
     * <p>
     * @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}
     */
    @Override
    @NonNull
    public String getDrmPropertyString(@NonNull @MediaDrm.StringProperty String propertyName)
            throws NoDrmSchemeException
    {
        Log.v(TAG, "getDrmPropertyString: propertyName: " + propertyName);

        String value;
        synchronized (mDrmLock) {

            if (!mActiveDrmScheme && !mDrmConfigAllowed) {
                Log.w(TAG, "getDrmPropertyString NoDrmSchemeException");
                throw new NoDrmSchemeExceptionImpl(
                        "getDrmPropertyString: Has to prepareDrm() first.");
            }

            try {
                value = mDrmObj.getPropertyString(propertyName);
            } catch (Exception e) {
                Log.w(TAG, "getDrmPropertyString Exception " + e);
                throw e;
            }
        }   // synchronized

        Log.v(TAG, "getDrmPropertyString: propertyName: " + propertyName + " --> value: " + value);

        return value;
    }


    /**
     * Set a DRM engine plugin String property value.
     * <p>
     * @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}
     */
    @Override
    public void setDrmPropertyString(@NonNull @MediaDrm.StringProperty String propertyName,
                                     @NonNull String value)
            throws NoDrmSchemeException
    {
        Log.v(TAG, "setDrmPropertyString: propertyName: " + propertyName + " value: " + value);

        synchronized (mDrmLock) {

            if ( !mActiveDrmScheme && !mDrmConfigAllowed ) {
                Log.w(TAG, "setDrmPropertyString NoDrmSchemeException");
                throw new NoDrmSchemeExceptionImpl(
                        "setDrmPropertyString: Has to prepareDrm() first.");
            }

            try {
                mDrmObj.setPropertyString(propertyName, value);
            } catch ( Exception e ) {
                Log.w(TAG, "setDrmPropertyString Exception " + e);
                throw e;
            }
        }   // synchronized
    }

    /**
     * Encapsulates the DRM properties of the source.
     */
    public static final class DrmInfoImpl extends DrmInfo {
        private Map<UUID, byte[]> mapPssh;
        private UUID[] supportedSchemes;

        /**
         * Returns the PSSH info of the data source for each supported DRM scheme.
         */
        @Override
        public Map<UUID, byte[]> getPssh() {
            return mapPssh;
        }

        /**
         * 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.
         */
        @Override
        public List<UUID> getSupportedSchemes() {
            return Arrays.asList(supportedSchemes);
        }

        private DrmInfoImpl(Map<UUID, byte[]> Pssh, UUID[] SupportedSchemes) {
            mapPssh = Pssh;
            supportedSchemes = SupportedSchemes;
        }

        private DrmInfoImpl(Parcel parcel) {
            Log.v(TAG, "DrmInfoImpl(" + parcel + ") size " + parcel.dataSize());

            int psshsize = parcel.readInt();
            byte[] pssh = new byte[psshsize];
            parcel.readByteArray(pssh);

            Log.v(TAG, "DrmInfoImpl() PSSH: " + arrToHex(pssh));
            mapPssh = parsePSSH(pssh, psshsize);
            Log.v(TAG, "DrmInfoImpl() PSSH: " + mapPssh);

            int supportedDRMsCount = parcel.readInt();
            supportedSchemes = new UUID[supportedDRMsCount];
            for (int i = 0; i < supportedDRMsCount; i++) {
                byte[] uuid = new byte[16];
                parcel.readByteArray(uuid);

                supportedSchemes[i] = bytesToUUID(uuid);

                Log.v(TAG, "DrmInfoImpl() supportedScheme[" + i + "]: " +
                      supportedSchemes[i]);
            }

            Log.v(TAG, "DrmInfoImpl() Parcel psshsize: " + psshsize +
                  " supportedDRMsCount: " + supportedDRMsCount);
        }

        private DrmInfoImpl makeCopy() {
            return new DrmInfoImpl(this.mapPssh, this.supportedSchemes);
        }

        private String arrToHex(byte[] bytes) {
            String out = "0x";
            for (int i = 0; i < bytes.length; i++) {
                out += String.format("%02x", bytes[i]);
            }

            return out;
        }

        private 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 Map<UUID, byte[]> parsePSSH(byte[] pssh, int psshsize) {
            Map<UUID, byte[]> result = new HashMap<UUID, byte[]>();

            final int UUID_SIZE = 16;
            final int DATALEN_SIZE = 4;

            int len = psshsize;
            int numentries = 0;
            int i = 0;

            while (len > 0) {
                if (len < UUID_SIZE) {
                    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 + UUID_SIZE);
                UUID uuid = bytesToUUID(subset);
                i += UUID_SIZE;
                len -= UUID_SIZE;

                // 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+DATALEN_SIZE);
                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 += DATALEN_SIZE;
                len -= DATALEN_SIZE;

                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;
        }

    };  // DrmInfoImpl

    /**
     * Thrown when a DRM method is called before preparing a DRM scheme through prepareDrm().
     * Extends MediaDrm.MediaDrmException
     */
    public static final class NoDrmSchemeExceptionImpl extends NoDrmSchemeException {
        public NoDrmSchemeExceptionImpl(String detailMessage) {
            super(detailMessage);
        }
    }

    /**
     * Thrown when the device requires DRM provisioning but the provisioning attempt has
     * failed due to a network error (Internet reachability, timeout, etc.).
     * Extends MediaDrm.MediaDrmException
     */
    public static final class ProvisioningNetworkErrorExceptionImpl
            extends ProvisioningNetworkErrorException {
        public ProvisioningNetworkErrorExceptionImpl(String detailMessage) {
            super(detailMessage);
        }
    }

    /**
     * Thrown when the device requires DRM provisioning but the provisioning attempt has
     * failed due to the provisioning server denying the request.
     * Extends MediaDrm.MediaDrmException
     */
    public static final class ProvisioningServerErrorExceptionImpl
            extends ProvisioningServerErrorException {
        public ProvisioningServerErrorExceptionImpl(String detailMessage) {
            super(detailMessage);
        }
    }


    private native void _prepareDrm(@NonNull byte[] uuid, @NonNull byte[] drmSessionId);

        // Modular DRM helpers

    private void prepareDrm_createDrmStep(@NonNull UUID uuid)
            throws UnsupportedSchemeException {
        Log.v(TAG, "prepareDrm_createDrmStep: UUID: " + uuid);

        try {
            mDrmObj = new MediaDrm(uuid);
            Log.v(TAG, "prepareDrm_createDrmStep: Created mDrmObj=" + mDrmObj);
        } catch (Exception e) { // UnsupportedSchemeException
            Log.e(TAG, "prepareDrm_createDrmStep: MediaDrm failed with " + e);
            throw e;
        }
    }

    private void prepareDrm_openSessionStep(@NonNull 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().
            _prepareDrm(getByteArrayFromUUID(uuid), mDrmSessionId);
            Log.v(TAG, "prepareDrm_openSessionStep: _prepareDrm/Crypto succeeded");

        } catch (Exception e) { //ResourceBusyException, NotProvisionedException
            Log.e(TAG, "prepareDrm_openSessionStep: open/crypto failed with " + e);
            throw e;
        }

    }

    // Called from the native side
    @SuppressWarnings("unused")
    private static boolean setAudioOutputDeviceById(AudioTrack track, int deviceId) {
        if (track == null) {
            return false;
        }

        if (deviceId == 0) {
            // Use default routing.
            track.setPreferredDevice(null);
            return true;
        }

        // TODO: Unhide AudioManager.getDevicesStatic.
        AudioDeviceInfo[] outputDevices =
                AudioManager.getDevicesStatic(AudioManager.GET_DEVICES_OUTPUTS);

        boolean success = false;
        for (AudioDeviceInfo device : outputDevices) {
            if (device.getId() == deviceId) {
                track.setPreferredDevice(device);
                success = true;
                break;
            }
        }
        return success;
    }

    // Instantiated from the native side
    @SuppressWarnings("unused")
    private static class StreamEventCallback extends AudioTrack.StreamEventCallback {
        public long mJAudioTrackPtr;
        public long mNativeCallbackPtr;
        public long mUserDataPtr;

        public 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 onStreamPresentationEnd(AudioTrack track) {
            native_stream_event_onStreamPresentationEnd(mNativeCallbackPtr, mUserDataPtr);
        }

        @Override
        public void onStreamDataRequest(AudioTrack track) {
            native_stream_event_onStreamDataRequest(
                    mJAudioTrackPtr, mNativeCallbackPtr, mUserDataPtr);
        }
    }

    private class ProvisioningThread extends Thread {
        public static final int TIMEOUT_MS = 60000;

        private UUID uuid;
        private String urlStr;
        private Object drmLock;
        private MediaPlayer2Impl mediaPlayer;
        private int status;
        private boolean finished;
        public  int status() {
            return status;
        }

        public ProvisioningThread initialize(MediaDrm.ProvisionRequest request,
                                          UUID uuid, MediaPlayer2Impl mediaPlayer) {
            // lock is held by the caller
            drmLock = mediaPlayer.mDrmLock;
            this.mediaPlayer = mediaPlayer;

            urlStr = request.getDefaultUrl() + "&signedRequest=" + new String(request.getData());
            this.uuid = uuid;

            status = PREPARE_DRM_STATUS_PREPARATION_ERROR;

            Log.v(TAG, "HandleProvisioninig: Thread is initialised url: " + urlStr);
            return this;
        }

        public void run() {

            byte[] response = null;
            boolean provisioningSucceeded = false;
            try {
                URL url = new URL(urlStr);
                final HttpURLConnection connection = (HttpURLConnection) url.openConnection();
                try {
                    connection.setRequestMethod("POST");
                    connection.setDoOutput(false);
                    connection.setDoInput(true);
                    connection.setConnectTimeout(TIMEOUT_MS);
                    connection.setReadTimeout(TIMEOUT_MS);

                    connection.connect();
                    response = Streams.readFully(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;

            boolean hasCallback = false;
            synchronized (mDrmEventCbLock) {
                hasCallback = !mDrmEventCallbackRecords.isEmpty();
            }
            // non-blocking mode needs the lock
            if (hasCallback) {

                synchronized (drmLock) {
                    // continuing with prepareDrm
                    if (provisioningSucceeded) {
                        succeeded = mediaPlayer.resumePrepareDrm(uuid);
                        status = (succeeded) ?
                                PREPARE_DRM_STATUS_SUCCESS :
                                PREPARE_DRM_STATUS_PREPARATION_ERROR;
                    }
                    mediaPlayer.mDrmProvisioningInProgress = false;
                    mediaPlayer.mPrepareDrmInProgress = false;
                    if (!succeeded) {
                        cleanDrmObj();  // cleaning up if it hasn't gone through while in the lock
                    }
                } // synchronized

                // calling the callback outside the lock
                synchronized (mDrmEventCbLock) {
                    for (Pair<Executor, DrmEventCallback> cb : mDrmEventCallbackRecords) {
                        cb.first.execute(() -> cb.second.onDrmPrepared(
                                mediaPlayer, mCurrentDSD, status));
                    }
                }
            } else {   // blocking mode already has the lock

                // continuing with prepareDrm
                if (provisioningSucceeded) {
                    succeeded = mediaPlayer.resumePrepareDrm(uuid);
                    status = (succeeded) ?
                            PREPARE_DRM_STATUS_SUCCESS :
                            PREPARE_DRM_STATUS_PREPARATION_ERROR;
                }
                mediaPlayer.mDrmProvisioningInProgress = false;
                mediaPlayer.mPrepareDrmInProgress = false;
                if (!succeeded) {
                    cleanDrmObj();  // cleaning up if it hasn't gone through
                }
            }

            finished = true;
        }   // run()

    }   // ProvisioningThread

    private int HandleProvisioninig(UUID uuid) {
        // the lock is already held by the caller

        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;

        mDrmProvisioningThread = new ProvisioningThread().initialize(provReq, uuid, this);
        mDrmProvisioningThread.start();

        int result;

        // non-blocking: this is not the final result
        boolean hasCallback = false;
        synchronized (mDrmEventCbLock) {
            hasCallback = !mDrmEventCallbackRecords.isEmpty();
        }
        if (hasCallback) {
            result = PREPARE_DRM_STATUS_SUCCESS;
        } else {
            // if blocking mode, wait till provisioning is done
            try {
                mDrmProvisioningThread.join();
            } catch (Exception e) {
                Log.w(TAG, "HandleProvisioninig: Thread.join Exception " + e);
            }
            result = mDrmProvisioningThread.status();
            // no longer need the thread
            mDrmProvisioningThread = null;
        }

        return result;
    }

    private boolean resumePrepareDrm(UUID uuid) {
        Log.v(TAG, "resumePrepareDrm: uuid: " + uuid);

        // mDrmLock is guaranteed to be held
        boolean success = false;
        try {
            // resuming
            prepareDrm_openSessionStep(uuid);

            mDrmUUID = uuid;
            mActiveDrmScheme = true;

            success = true;
        } catch (Exception e) {
            Log.w(TAG, "HandleProvisioninig: Thread run _prepareDrm resume failed with " + e);
            // mDrmObj clean up is done by the caller
        }

        return success;
    }

    private void resetDrmState() {
        synchronized (mDrmLock) {
            Log.v(TAG, "resetDrmState: " +
                    " mDrmInfoImpl=" + mDrmInfoImpl +
                    " mDrmProvisioningThread=" + mDrmProvisioningThread +
                    " mPrepareDrmInProgress=" + mPrepareDrmInProgress +
                    " mActiveDrmScheme=" + mActiveDrmScheme);

            mDrmInfoResolved = false;
            mDrmInfoImpl = null;

            if (mDrmProvisioningThread != null) {
                // timeout; relying on HttpUrlConnection
                try {
                    mDrmProvisioningThread.join();
                }
                catch (InterruptedException e) {
                    Log.w(TAG, "resetDrmState: ProvThread.join Exception " + e);
                }
                mDrmProvisioningThread = null;
            }

            mPrepareDrmInProgress = false;
            mActiveDrmScheme = false;

            cleanDrmObj();
        }   // synchronized
    }

    private void cleanDrmObj() {
        // the caller holds mDrmLock
        Log.v(TAG, "cleanDrmObj: mDrmObj=" + mDrmObj + " mDrmSessionId=" + mDrmSessionId);

        if (mDrmSessionId != null)    {
            mDrmObj.closeSession(mDrmSessionId);
            mDrmSessionId = null;
        }
        if (mDrmObj != null) {
            mDrmObj.release();
            mDrmObj = null;
        }
    }

    private static final 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;
    }

    // Modular DRM end

    /*
     * Test whether a given video scaling mode is supported.
     */
    private boolean isVideoScalingModeSupported(int mode) {
        return (mode == VIDEO_SCALING_MODE_SCALE_TO_FIT ||
                mode == VIDEO_SCALING_MODE_SCALE_TO_FIT_WITH_CROPPING);
    }

    /** @hide */
    static class TimeProvider implements MediaTimeProvider {
        private static final String TAG = "MTP";
        private static final long MAX_NS_WITHOUT_POSITION_CHECK = 5000000000L;
        private static final long MAX_EARLY_CALLBACK_US = 1000;
        private static final long TIME_ADJUSTMENT_RATE = 2;  /* meaning 1/2 */
        private long mLastTimeUs = 0;
        private MediaPlayer2Impl mPlayer;
        private boolean mPaused = true;
        private boolean mStopped = true;
        private boolean mBuffering;
        private long mLastReportedTime;
        // since we are expecting only a handful listeners per stream, there is
        // no need for log(N) search performance
        private MediaTimeProvider.OnMediaTimeListener mListeners[];
        private long mTimes[];
        private EventHandler mEventHandler;
        private boolean mRefresh = false;
        private boolean mPausing = false;
        private boolean mSeeking = false;
        private static final int NOTIFY = 1;
        private static final int NOTIFY_TIME = 0;
        private static final int NOTIFY_STOP = 2;
        private static final int NOTIFY_SEEK = 3;
        private static final int NOTIFY_TRACK_DATA = 4;
        private HandlerThread mHandlerThread;

        /** @hide */
        public boolean DEBUG = false;

        public TimeProvider(MediaPlayer2Impl mp) {
            mPlayer = mp;
            try {
                getCurrentTimeUs(true, false);
            } catch (IllegalStateException e) {
                // we assume starting position
                mRefresh = true;
            }

            Looper looper;
            if ((looper = Looper.myLooper()) == null &&
                (looper = Looper.getMainLooper()) == null) {
                // Create our own looper here in case MP was created without one
                mHandlerThread = new HandlerThread("MediaPlayer2MTPEventThread",
                      Process.THREAD_PRIORITY_FOREGROUND);
                mHandlerThread.start();
                looper = mHandlerThread.getLooper();
            }
            mEventHandler = new EventHandler(looper);

            mListeners = new MediaTimeProvider.OnMediaTimeListener[0];
            mTimes = new long[0];
            mLastTimeUs = 0;
        }

        private void scheduleNotification(int type, long delayUs) {
            // ignore time notifications until seek is handled
            if (mSeeking && type == NOTIFY_TIME) {
                return;
            }

            if (DEBUG) Log.v(TAG, "scheduleNotification " + type + " in " + delayUs);
            mEventHandler.removeMessages(NOTIFY);
            Message msg = mEventHandler.obtainMessage(NOTIFY, type, 0);
            mEventHandler.sendMessageDelayed(msg, (int) (delayUs / 1000));
        }

        /** @hide */
        public void close() {
            mEventHandler.removeMessages(NOTIFY);
            if (mHandlerThread != null) {
                mHandlerThread.quitSafely();
                mHandlerThread = null;
            }
        }

        /** @hide */
        protected void finalize() {
            if (mHandlerThread != null) {
                mHandlerThread.quitSafely();
            }
        }

        /** @hide */
        public void onNotifyTime() {
            synchronized (this) {
                if (DEBUG) Log.d(TAG, "onNotifyTime: ");
                scheduleNotification(NOTIFY_TIME, 0 /* delay */);
            }
        }

        /** @hide */
        public void onPaused(boolean paused) {
            synchronized(this) {
                if (DEBUG) Log.d(TAG, "onPaused: " + paused);
                if (mStopped) { // handle as seek if we were stopped
                    mStopped = false;
                    mSeeking = true;
                    scheduleNotification(NOTIFY_SEEK, 0 /* delay */);
                } else {
                    mPausing = paused;  // special handling if player disappeared
                    mSeeking = false;
                    scheduleNotification(NOTIFY_TIME, 0 /* delay */);
                }
            }
        }

        /** @hide */
        public void onBuffering(boolean buffering) {
            synchronized (this) {
                if (DEBUG) Log.d(TAG, "onBuffering: " + buffering);
                mBuffering = buffering;
                scheduleNotification(NOTIFY_TIME, 0 /* delay */);
            }
        }

        /** @hide */
        public void onStopped() {
            synchronized(this) {
                if (DEBUG) Log.d(TAG, "onStopped");
                mPaused = true;
                mStopped = true;
                mSeeking = false;
                mBuffering = false;
                scheduleNotification(NOTIFY_STOP, 0 /* delay */);
            }
        }

        /** @hide */
        public void onSeekComplete(MediaPlayer2Impl mp) {
            synchronized(this) {
                mStopped = false;
                mSeeking = true;
                scheduleNotification(NOTIFY_SEEK, 0 /* delay */);
            }
        }

        /** @hide */
        public void onNewPlayer() {
            if (mRefresh) {
                synchronized(this) {
                    mStopped = false;
                    mSeeking = true;
                    mBuffering = false;
                    scheduleNotification(NOTIFY_SEEK, 0 /* delay */);
                }
            }
        }

        private synchronized void notifySeek() {
            mSeeking = false;
            try {
                long timeUs = getCurrentTimeUs(true, false);
                if (DEBUG) Log.d(TAG, "onSeekComplete at " + timeUs);

                for (MediaTimeProvider.OnMediaTimeListener listener: mListeners) {
                    if (listener == null) {
                        break;
                    }
                    listener.onSeek(timeUs);
                }
            } catch (IllegalStateException e) {
                // we should not be there, but at least signal pause
                if (DEBUG) Log.d(TAG, "onSeekComplete but no player");
                mPausing = true;  // special handling if player disappeared
                notifyTimedEvent(false /* refreshTime */);
            }
        }

        private synchronized void notifyTrackData(Pair<SubtitleTrack, byte[]> trackData) {
            SubtitleTrack track = trackData.first;
            byte[] data = trackData.second;
            track.onData(data, true /* eos */, ~0 /* runID: keep forever */);
        }

        private synchronized void notifyStop() {
            for (MediaTimeProvider.OnMediaTimeListener listener: mListeners) {
                if (listener == null) {
                    break;
                }
                listener.onStop();
            }
        }

        private int registerListener(MediaTimeProvider.OnMediaTimeListener listener) {
            int i = 0;
            for (; i < mListeners.length; i++) {
                if (mListeners[i] == listener || mListeners[i] == null) {
                    break;
                }
            }

            // new listener
            if (i >= mListeners.length) {
                MediaTimeProvider.OnMediaTimeListener[] newListeners =
                    new MediaTimeProvider.OnMediaTimeListener[i + 1];
                long[] newTimes = new long[i + 1];
                System.arraycopy(mListeners, 0, newListeners, 0, mListeners.length);
                System.arraycopy(mTimes, 0, newTimes, 0, mTimes.length);
                mListeners = newListeners;
                mTimes = newTimes;
            }

            if (mListeners[i] == null) {
                mListeners[i] = listener;
                mTimes[i] = MediaTimeProvider.NO_TIME;
            }
            return i;
        }

        public void notifyAt(
                long timeUs, MediaTimeProvider.OnMediaTimeListener listener) {
            synchronized(this) {
                if (DEBUG) Log.d(TAG, "notifyAt " + timeUs);
                mTimes[registerListener(listener)] = timeUs;
                scheduleNotification(NOTIFY_TIME, 0 /* delay */);
            }
        }

        public void scheduleUpdate(MediaTimeProvider.OnMediaTimeListener listener) {
            synchronized(this) {
                if (DEBUG) Log.d(TAG, "scheduleUpdate");
                int i = registerListener(listener);

                if (!mStopped) {
                    mTimes[i] = 0;
                    scheduleNotification(NOTIFY_TIME, 0 /* delay */);
                }
            }
        }

        public void cancelNotifications(
                MediaTimeProvider.OnMediaTimeListener listener) {
            synchronized(this) {
                int i = 0;
                for (; i < mListeners.length; i++) {
                    if (mListeners[i] == listener) {
                        System.arraycopy(mListeners, i + 1,
                                mListeners, i, mListeners.length - i - 1);
                        System.arraycopy(mTimes, i + 1,
                                mTimes, i, mTimes.length - i - 1);
                        mListeners[mListeners.length - 1] = null;
                        mTimes[mTimes.length - 1] = NO_TIME;
                        break;
                    } else if (mListeners[i] == null) {
                        break;
                    }
                }

                scheduleNotification(NOTIFY_TIME, 0 /* delay */);
            }
        }

        private synchronized void notifyTimedEvent(boolean refreshTime) {
            // figure out next callback
            long nowUs;
            try {
                nowUs = getCurrentTimeUs(refreshTime, true);
            } catch (IllegalStateException e) {
                // assume we paused until new player arrives
                mRefresh = true;
                mPausing = true; // this ensures that call succeeds
                nowUs = getCurrentTimeUs(refreshTime, true);
            }
            long nextTimeUs = nowUs;

            if (mSeeking) {
                // skip timed-event notifications until seek is complete
                return;
            }

            if (DEBUG) {
                StringBuilder sb = new StringBuilder();
                sb.append("notifyTimedEvent(").append(mLastTimeUs).append(" -> ")
                        .append(nowUs).append(") from {");
                boolean first = true;
                for (long time: mTimes) {
                    if (time == NO_TIME) {
                        continue;
                    }
                    if (!first) sb.append(", ");
                    sb.append(time);
                    first = false;
                }
                sb.append("}");
                Log.d(TAG, sb.toString());
            }

            Vector<MediaTimeProvider.OnMediaTimeListener> activatedListeners =
                new Vector<MediaTimeProvider.OnMediaTimeListener>();
            for (int ix = 0; ix < mTimes.length; ix++) {
                if (mListeners[ix] == null) {
                    break;
                }
                if (mTimes[ix] <= NO_TIME) {
                    // ignore, unless we were stopped
                } else if (mTimes[ix] <= nowUs + MAX_EARLY_CALLBACK_US) {
                    activatedListeners.add(mListeners[ix]);
                    if (DEBUG) Log.d(TAG, "removed");
                    mTimes[ix] = NO_TIME;
                } else if (nextTimeUs == nowUs || mTimes[ix] < nextTimeUs) {
                    nextTimeUs = mTimes[ix];
                }
            }

            if (nextTimeUs > nowUs && !mPaused) {
                // schedule callback at nextTimeUs
                if (DEBUG) Log.d(TAG, "scheduling for " + nextTimeUs + " and " + nowUs);
                mPlayer.notifyAt(nextTimeUs);
            } else {
                mEventHandler.removeMessages(NOTIFY);
                // no more callbacks
            }

            for (MediaTimeProvider.OnMediaTimeListener listener: activatedListeners) {
                listener.onTimedEvent(nowUs);
            }
        }

        public long getCurrentTimeUs(boolean refreshTime, boolean monotonic)
                throws IllegalStateException {
            synchronized (this) {
                // we always refresh the time when the paused-state changes, because
                // we expect to have received the pause-change event delayed.
                if (mPaused && !refreshTime) {
                    return mLastReportedTime;
                }

                try {
                    mLastTimeUs = mPlayer.getCurrentPosition() * 1000L;
                    mPaused = !mPlayer.isPlaying() || mBuffering;
                    if (DEBUG) Log.v(TAG, (mPaused ? "paused" : "playing") + " at " + mLastTimeUs);
                } catch (IllegalStateException e) {
                    if (mPausing) {
                        // if we were pausing, get last estimated timestamp
                        mPausing = false;
                        if (!monotonic || mLastReportedTime < mLastTimeUs) {
                            mLastReportedTime = mLastTimeUs;
                        }
                        mPaused = true;
                        if (DEBUG) Log.d(TAG, "illegal state, but pausing: estimating at " + mLastReportedTime);
                        return mLastReportedTime;
                    }
                    // TODO get time when prepared
                    throw e;
                }
                if (monotonic && mLastTimeUs < mLastReportedTime) {
                    /* have to adjust time */
                    if (mLastReportedTime - mLastTimeUs > 1000000) {
                        // schedule seeked event if time jumped significantly
                        // TODO: do this properly by introducing an exception
                        mStopped = false;
                        mSeeking = true;
                        scheduleNotification(NOTIFY_SEEK, 0 /* delay */);
                    }
                } else {
                    mLastReportedTime = mLastTimeUs;
                }

                return mLastReportedTime;
            }
        }

        private class EventHandler extends Handler {
            public EventHandler(Looper looper) {
                super(looper);
            }

            @Override
            public void handleMessage(Message msg) {
                if (msg.what == NOTIFY) {
                    switch (msg.arg1) {
                    case NOTIFY_TIME:
                        notifyTimedEvent(true /* refreshTime */);
                        break;
                    case NOTIFY_STOP:
                        notifyStop();
                        break;
                    case NOTIFY_SEEK:
                        notifySeek();
                        break;
                    case NOTIFY_TRACK_DATA:
                        notifyTrackData((Pair<SubtitleTrack, byte[]>)msg.obj);
                        break;
                    }
                }
            }
        }
    }

    private abstract class Task implements Runnable {
        private final int mMediaCallType;
        private final boolean mNeedToWaitForEventToComplete;
        private DataSourceDesc mDSD;

        public 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 {
                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 (Exception e) {
                status = CALL_STATUS_ERROR_UNKNOWN;
            }
            synchronized (mSrcLock) {
                mDSD = mCurrentDSD;
            }

            // 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()}.
            if (mMediaCallType == CALL_COMPLETED_NOTIFY_WHEN_COMMAND_LABEL_REACHED) {
                return;
            }
            synchronized (mEventCbLock) {
                for (Pair<Executor, MediaPlayer2EventCallback> cb : mEventCallbackRecords) {
                    cb.first.execute(() -> cb.second.onCallCompleted(
                            MediaPlayer2Impl.this, mDSD, mMediaCallType, status));
                }
            }
        }
    };
}