Shuffle play is buggy when shufflePlay is enabled before addition of mediaitems

[tzugen]

Media3 Version

1.0.0-rc02

Devices that reproduce the issue

Pixel 3

Devices that do not reproduce the issue

No response

Reproducible in the demo app?

Not tested

Reproduction steps

1. addMediaItems to controller
2. setPlayWhenReady = true
3. prepare
4. They will start playing
5. Wait for playback to finish
6. Playbackstate is now 4
7. addMediaItems once more
8. setPlayWhenReady = true
9. prepare
10. They don't play

Expected result

It plays each time

Actual result

--

Media

--

Bug Report

• [ ] You will email the zip file produced by adb bugreport to dev.exoplayer@gmail.com after filing this issue.

[tzugen]

This can be "fixed" by calling seekTo(0,0L) on the controller. But if shuffle mode is enabled it will cause the playlist always to start with the first item.

[marcbaechinger]

Once the player has transitioned to STATE_ENDED you need to seek to a position before the end of the playlist to get out of STATE_ENDED. This is working as intended.

When player.prepare() has been called, any subsequent calls to prepare are no-ops.

[marcbaechinger]

But if shuffle mode is enabled it will cause the playlist always to start with the first item.

If you call seekTo(/* windowIndex=*/ 0, /* positionMs= */ 0L), then the player starts at windowIndex 0 not at the index 0 of the shuffle sequence.

To seek to the first window of the shuffle sequence you can do:

player.getCurrentTimeline();
int windowIndex = timeline.getFirstWindowIndex(/* shuffleModeEnabled= */ true);
seekTo(windowIndex, /* positionMs= */ C.TIME_UNSET)

I'm closing this issue as it seem answered. Please reopen if you think something needs to be added.

[tzugen]

Ok, that answers it. Maybe its something that could be added to the docs. I'll open a PR

[tzugen]

But if shuffle mode is enabled it will cause the playlist always to start with the first item.

If you call seekTo(/* windowIndex=*/ 0, /* positionMs= */ 0L), then the player starts at windowIndex 0 not at the index 0 of the shuffle sequence.

To seek to the first window of the shuffle sequence you can do:

player.getCurrentTimeline();
int windowIndex = timeline.getFirstWindowIndex(/* shuffleModeEnabled= */ true);
seekTo(windowIndex, /* positionMs= */ C.TIME_UNSET)

I'm closing this issue as it seem answered. Please reopen if you think something needs to be added.

Unfortunately I have to report that this does not work.

    var isShufflePlayEnabled: Boolean
        get() = controller?.shuffleModeEnabled == true
        set(enabled) {
            controller?.shuffleModeEnabled = enabled
        }

    @Synchronized
    fun addToPlaylist(
        songs: List<Track>,
        cachePermanently: Boolean,
        autoPlay: Boolean,
        shuffle: Boolean
    ) {

        if (shuffle) isShufflePlayEnabled = true
        controller?.addMediaItems(insertAt, mediaItems)

        prepare()

        // Playback doesn't start correctly when the player is in STATE_ENDED.
        // So we need to call seek before (this is what play(0,0)) does.
        // We can't just use play(0,0) then all random playlists will start with the first track.
        // This means that we need to generate the random first track ourselves.
        if (autoPlay) {
            debugShuffleState(isShufflePlayEnabled)
            val start = controller?.currentTimeline?.getFirstWindowIndex(isShufflePlayEnabled) ?: 0
            play(start)
        }
    }

This is our current code. But if shuffle play is enabled before adding the items, the items are not shuffled after insertion. Meaning that getFirstWindowIndex will be 0 anyway...

Console:

13:43:34.715 PlaybackStateSerializer   org.moire.ultrasonic.debug  I  Serialized currentPlayingIndex: -1, currentPlayingPosition: 0, shuffle: true
13:43:34.787 MediaPlayerController     org.moire.ultrasonic.debug  D  Shuffle: windowIndex: 0, at: 0
13:43:34.788 MediaPlayerController     org.moire.ultrasonic.debug  D  Shuffle: windowIndex: 1, at: 1
13:43:34.788 MediaPlayerController     org.moire.ultrasonic.debug  D  Shuffle: windowIndex: 2, at: 2
13:43:34.788 MediaPlayerController     org.moire.ultrasonic.debug  D  Shuffle: windowIndex: 3, at: 3
13:43:34.789 MediaPlayerController     org.moire.ultrasonic.debug  D  Shuffle: windowIndex: 4, at: 4
13:43:34.789 MediaPlayerController     org.moire.ultrasonic.debug  D  Shuffle: windowIndex: 5, at: 5
13:43:34.789 MediaPlayerController     org.moire.ultrasonic.debug  D  Shuffle: windowIndex: 6, at: 6
13:43:34.789 MediaPlayerController     org.moire.ultrasonic.debug  D  Shuffle: windowIndex: 7, at: 7
13:43:34.790 MediaPlayerController     org.moire.ultrasonic.debug  D  Shuffle: windowIndex: 8, at: 8
13:43:34.790 MediaPlayerController     org.moire.ultrasonic.debug  D  Shuffle: windowIndex: 9, at: 9
13:43:34.790 MediaPlayerController     org.moire.ultrasonic.debug  D  Shuffle: windowIndex: -1, at: 10
13:43:35.244 PlaybackStateSerializer   org.moire.ultrasonic.debug  I  Serialized currentPlayingIndex: 0, currentPlayingPosition: 0, shuffle: true

As you can see I call debugShuffleState() to log the current shuffle windows just before calling getFirstWindowIndex and seekTo(), but at this point its not shuffled.

Afterwards two things might happen. Either it continues in a shuffled way (with the problems I mention in the other bug) or often it refuses to play after the first song at all.

[tzugen]

ps. i don't have the rights to reopen