ExoPlayer 2 Playlist Listener

Question

I'm using the new features from ExoPlayer 2.x to play a list of audio files like this:

List<MediaSource> playlist = new ArrayList<>();

...

ConcatenatingMediaSource concatenatedSource = new ConcatenatingMediaSource(
            playlist.toArray(new MediaSource[playlist.size()]));

mExoPlayer.prepare(concatenatedSource);
mExoPlayer.setPlayWhenReady(true);

This is working fine, but in order to update my UI accordingly, I need to know which track is currently playing and the progress of this track. Is there any listener from ExoPlayer?

Thanks!

Answer 1

So I am in a similar scenario and need to know when the next video in the playlist starts. I found that the ExoPlayer.EventListener has a method called onPositionDiscontinuity() that gets called every time the video changes or "seeks" to the next in the playlist.

I haven't played around with this method extensively, but from what I can see so far, this is the method that you should be concerned about. There are no parameters that get passed when the method is fired, so you'll have to keep some kind of counter or queue to keep track of whats being played at any given moment.

Hopefully this helps!

Edit: change in index returned by Exoplayer.getCurrentWindowIndex() is the recommended way to detect item change in a playlist MediaSource.

int lastWindowIndex = 0; // global var in your class encapsulating exoplayer obj (Activity, etc.)

exoPlayer.addListener(new ExoPlayer.EventListener() {
        @Override
        public void onLoadingChanged(boolean isLoading) {
        }

        @Override
        public void onPlayerStateChanged(boolean playWhenReady, int playbackState) {
        }

        @Override
        public void onTimelineChanged(Timeline timeline, Object manifest) {
        }

        @Override
        public void onPlayerError(ExoPlaybackException error) {
        }

        @Override
        public void onPositionDiscontinuity() {
            //THIS METHOD GETS CALLED FOR EVERY NEW SOURCE THAT IS PLAYED
            int latestWindowIndex = exoPlayer.getCurrentWindowIndex();
            if (latestWindowIndex != lastWindowIndex) {
                // item selected in playlist has changed, handle here
                lastWindowIndex = latestWindowIndex;
                // ...
            }
        }
    });

Answer 2

You can implement the following event and update your ui according to the player's state.

 mExoPlayer.addListener(new ExoPlayer.Listener() {
            @Override
            public void onPlayerStateChanged(boolean playWhenReady, int playbackState) {
                if (playbackState == PlaybackStateCompat.STATE_PLAYING) {
                    //do something                 
                }
            }

            @Override
            public void onPlayWhenReadyCommitted() {

            }

            @Override
            public void onPlayerError(ExoPlaybackException error) {
                mExoPlayer.stop();

            }
        });

Answer 3

Since the answer here did not work for me, I will add my working solution in Kotlin. And also there are lots of methods deprecated since then.

You can track the current track(video) by setting a mediaId when creating your playlist

Gradle:

implementation 'com.google.android.exoplayer:exoplayer:2.14.1'

Layout xml:

<com.google.android.exoplayer2.ui.PlayerView
    android:id="@+id/player_view"
    android:layout_width="match_parent"
    android:layout_height="100dp"
    app:show_buffering="when_playing"/>

Code:

private lateinit var exoPlayer: SimpleExoPlayer
private lateinit var playerView: PlayerView
private lateinit var fileList: List<FileModel>

private fun initPlayer() {
    playerView = findViewById(R.id.player_view)
    playerView.controllerShowTimeoutMs = 0
    playerView.cameraDistance = 30F
    exoPlayer = SimpleExoPlayer.Builder(this).build()
    playerView.player = exoPlayer

    setPlaylist()
    exoPlayer.prepare()
    exoPlayer.seekTo(position, C.TIME_UNSET) // position = current song or video
    exoPlayer.playWhenReady = true
    addPlayerListeners()
}

private fun setPlaylist() {
    for ((pos, file) in fileList.withIndex()) {
        val mediaItem = MediaItem.Builder().setUri(file.url).setMediaId(pos.toString()).build()
        exoPlayer.addMediaItem(mediaItem)
    }
}

private fun addPlayerListeners() {
    exoPlayer.addListener(object : Player.Listener{
        override fun onMediaItemTransition(mediaItem: MediaItem?, reason: Int) {
            super.onMediaItemTransition(mediaItem, reason)
            val  item = mediaItem?.mediaMetadata
            val bmp = item?.artworkData
            Log.i(TAG, "position = ${mediaItem?.mediaId}")
            val currentPos = mediaItem?.mediaId
            updateViews(currentPos, bmp)
        }
    })
}

private fun updateViews(currentPos: String?, bmp: ByteArray?) {
    position = currentPos?.toInt() ?: 0
    val title = fileList[position].title
    textview_title.text = title

    if (bmp == null) {
        image_view.setImageResource(R.drawable.exo_ic_default_album_image)
        return
    }
    val bitmap = BitmapFactory.decodeByteArray(bmp, 0, bmp.size)
    image_view.setImageBitmap(bitmap)
}