[ui-compose] PresentationState crashes after replacing MediaItem on MediaController during live stream playback #3264

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1. Geletinousamigo

   added

   bug

   needs triage

   on Jun 4, 2026
2. oceanjules

   self-assigned this

   on Jun 5, 2026
3. oceanjules commented on Jun 5, 2026

   

   oceanjules

   on Jun 5, 2026

   Contributor

   More actions

   Thanks Nikhil!

   You are right, the bug comes from this chunk

   media/libraries/ui_compose/src/main/java/androidx/media3/ui/compose/state/PresentationState.kt

   Lines 156 to 176 in 5fb3064

   	private fun shouldKeepSurfaceVisible(player: Player): Boolean {
   	// Suppress the shutter if transitioning to an unprepared period within the same window. This
   	// is necessary to avoid closing the shutter (i.e covering the surface) when such a transition
   	// occurs. See: https://github.com/google/ExoPlayer/issues/5507.
   	val timeline =
   	if (player.isCommandAvailable(Player.COMMAND_GET_TIMELINE)) player.currentTimeline
   	else Timeline.EMPTY
   	if (timeline.isEmpty) {
   	lastPeriodUidWithTracks = null
   	return false
   	}
   	val period = Timeline.Period()
   	if (player.isCommandAvailable(Player.COMMAND_GET_TRACKS) && !player.currentTracks.isEmpty) {
   	lastPeriodUidWithTracks =
   	timeline.getPeriod(player.currentPeriodIndex, period, /* setIds= */ true).uid
   	} else
   	lastPeriodUidWithTracks?.let {
   	val lastPeriodIndexWithTracks = timeline.getIndexOfPeriod(it)
   	if (lastPeriodIndexWithTracks != C.INDEX_UNSET) {

   .. which came from the PlayerView:

   media/libraries/ui/src/main/java/androidx/media3/ui/PlayerView.java

   Lines 1915 to 1926 in 5fb3064

   	@Override
   	public void onTracksChanged(Tracks tracks) {
   	// Suppress the update if transitioning to an unprepared period within the same window. This
   	// is necessary to avoid closing the shutter when such a transition occurs. See:
   	// https://github.com/google/ExoPlayer/issues/5507.
   	Player player = checkNotNull(PlayerView.this.player);
   	Timeline timeline =
   	player.isCommandAvailable(COMMAND_GET_TIMELINE)
   	? player.getCurrentTimeline()
   	: Timeline.EMPTY;
   	if (timeline.isEmpty()) {
   	lastPeriodUidWithTracks = null;

   MediaController is operating across an IPC boundary and to prevent exceeding Binder transaction limits, Media3 strips granular data (like Period UIDs) and passes a specialized RemotableTimeline to the controller. By design, RemotableTimeline drops UIDs and explicitly throws an UnsupportedOperationException whenever getIndexOfPeriod(Object uid) is invoked.

   I see 2 ways forward:

   1. Just use the index of the currently playing period (player.currentPeriodIndex)
      If the Compose state is unnecessarily extracting the UID just to find out where we are in the timeline. MediaController natively syncs this value, bypassing the timeline UID lookup entirely and avoiding the crash.

   2. Add a fallback for the MediaController case.

   private fun shouldKeepSurfaceVisible(player: Player): Boolean {
       // ... 
       val index = try {
           player.currentTimeline.getIndexOfPeriod(cachedPeriodUid)
       } catch (e: UnsupportedOperationException) {
           // Fallback for MediaController / RemotableTimeline where UIDs are stripped.
           // We cannot verify precise period identity, so we fallback to checking if the 
           // MediaItem identity has remained the same, or if the player still has 
           // an active video track.
           val hasVideoTrack = player.currentTracks.isTypeSupported(C.TRACK_TYPE_VIDEO)
           val isSameMediaItem = player.currentMediaItem?.mediaId == cachedMediaId
           return isSameMediaItem && hasVideoTrack
       }
       return index != C.INDEX_UNSET
   }

   I will try out different strategies and get back to you with our solution. I'm surprised it hasn't ever crashed on the Views side, because there is nothing that Compose is adding in terms of layering.
4. oceanjules

   removed

   needs triage

   on Jun 5, 2026
5. copybara-service

   added a commit that references this issue on Jun 11, 2026

   [ui-compose] Add a presentation state test with unsupported exception

   ...

   75cb847
6. copybara-service

   added a commit that references this issue on Jun 23, 2026

   Map and propagate Timeline UIDs across the IPC boundary

   ...

   58f500f
7. oceanjules

   closed this as completedon Jul 23, 2026
8. androidx

   locked and limited conversation to collaborators on Sep 22, 2026