Crash when player.removeMediaItems is called during postroll (advert at C.TIME_END_OF_SOURCE)

[amorenkov]

Version

Media3 1.7.1 (same as 1.6.1)

More version details

No response

Devices that reproduce the issue

Pixel 6 running Android 15
Samsung S23 Ultra running Android 14
Pixel 9 emulator running Android 15
Techno Spark 20 Pro running Android 13

Devices that do not reproduce the issue

No

Reproducible in the demo app?

Not tested

Reproduction steps

We have a video-based application with custom ads logic (not IMA). Steps to reproduce describe the simplified logic from our application

Steps to reproduce:

1. Start any video playing by ExoPlayer class:

val videoA = MediaItem.fromUri(<any mp4 video url>)
player.addMediaItem(videoA)
player.prepare()
player.play()

2. Add some media items to player next to current video (playlist):

val videoB = MediaItem.fromUri(<any mp4 video url>)
val videoC = MediaItem.fromUri(<any mp4 video url>)
player.addMediaItem(videoB)
player.addMediaItem(videoC)

3. Apply postroll url to AdPlaybackState and send it to player for current video (in our app we implemented AdsLoader with correct connecting it to mediaSourceFactory etc, but here is only snippet of simplified core logic):

val postrollMediaItem = MediaItem.Builder().setUri(<any mp4 video url>).build()
val adPlaybackState = AdPlaybackState(adsId, C.TIME_END_OF_SOURCE)
.withAdCount(0, 1)
.withAvailableAdMediaItem(0,0, postrollMediaItem)

AdsLoader.EventListener.onAdPlaybackState(adPlaybackState )

4. Wait until almost the very end of the video (for example if video duration is 60.000ms, the position we are interested is ~59.000-59.900ms)

5. At this time moment, clear playlist, apply new video to playlist and switch to next media item (at this moment player.isPlayingAd == false):

// Clears videoB and videoC from player's playlist
player.removeMediaItems(player.currentMediaItemIndex + 1, player.mediaItemCount)
// Setup new playlist as VideoX
val videoX = MediaItem.fromUri(<any mp4 video url>)
player.addMediaItem(videoX)
// Switch to next media item (i.e VideoX)
player.seekToNextMediaItem()

Expected result

Player successfully seek to new next media item (i.e VideoX)

Actual result

Not always, but quite often we get a crash:

java.lang.IllegalStateException
                 	at androidx.media3.common.util.Assertions.checkState(Assertions.java:85)
                 	at androidx.media3.exoplayer.ExoPlayerImpl.maskTimelineAndPosition(ExoPlayerImpl.java:2480)
                 	at androidx.media3.exoplayer.ExoPlayerImpl.removeMediaItemsInternal(ExoPlayerImpl.java:2410)
                 	at androidx.media3.exoplayer.ExoPlayerImpl.removeMediaItems(ExoPlayerImpl.java:674)
                 	at <Our app player wrapper class>.removeMediaItems(just call ExoPlayer's method without specific logic)
                 	at androidx.media3.common.ForwardingPlayer.removeMediaItems(ForwardingPlayer.java:189)
                 	at androidx.media3.session.PlayerWrapper.removeMediaItems(PlayerWrapper.java:594)
                 	at androidx.media3.session.MediaSessionStub.lambda$removeMediaItems$43$androidx-media3-session-MediaSessionStub(MediaSessionStub.java:1298)
                 	at androidx.media3.session.MediaSessionStub$$ExternalSyntheticLambda0.run(D8$$SyntheticClass:0)
                 	at androidx.media3.session.MediaSessionStub.lambda$sendSessionResultSuccess$1(MediaSessionStub.java:174)
                 	at androidx.media3.session.MediaSessionStub$$ExternalSyntheticLambda84.run(D8$$SyntheticClass:0)
                 	at androidx.media3.session.MediaSessionStub.lambda$queueSessionTaskWithPlayerCommandForControllerInfo$13(MediaSessionStub.java:344)
                 	at androidx.media3.session.MediaSessionStub$$ExternalSyntheticLambda40.run(D8$$SyntheticClass:0)
                 	at androidx.media3.session.ConnectedControllersManager.lambda$flushCommandQueue$3$androidx-media3-session-ConnectedControllersManager(ConnectedControllersManager.java:295)
                 	at androidx.media3.session.ConnectedControllersManager$$ExternalSyntheticLambda0.run(D8$$SyntheticClass:0)
                 	at androidx.media3.session.MediaSessionImpl.lambda$callWithControllerForCurrentRequestSet$3$androidx-media3-session-MediaSessionImpl(MediaSessionImpl.java:355)
                 	at androidx.media3.session.MediaSessionImpl$$ExternalSyntheticLambda21.run(D8$$SyntheticClass:0)
                 	at androidx.media3.common.util.Util.postOrRun(Util.java:800)
                 	at androidx.media3.session.ConnectedControllersManager.flushCommandQueue(ConnectedControllersManager.java:289)
                 	at androidx.media3.session.ConnectedControllersManager.flushCommandQueue(ConnectedControllersManager.java:270)
                 	at androidx.media3.session.MediaSessionStub.lambda$flushCommandQueue$64$androidx-media3-session-MediaSessionStub(MediaSessionStub.java:1692)
                 	at androidx.media3.session.MediaSessionStub$$ExternalSyntheticLambda37.run(D8$$SyntheticClass:0)
                 	at androidx.media3.common.util.Util.postOrRun(Util.java:800)
                 	at androidx.media3.session.MediaSessionStub.flushCommandQueue(MediaSessionStub.java:1690)
                 	at androidx.media3.session.MediaControllerImplBase$FlushCommandQueueHandler.flushCommandQueue(MediaControllerImplBase.java:3646)
                 	at androidx.media3.session.MediaControllerImplBase$FlushCommandQueueHandler.handleMessage(MediaControllerImplBase.java:3639)
                 	at androidx.media3.session.MediaControllerImplBase$FlushCommandQueueHandler.$r8$lambda$TVKiXTCmsW2hn-6HNXqbaigkfJc(Unknown Source:0)
                 	at androidx.media3.session.MediaControllerImplBase$FlushCommandQueueHandler$$ExternalSyntheticLambda0.handleMessage(D8$$SyntheticClass:0)
                 	at android.os.Handler.dispatchMessage(Handler.java:103)
                 	at android.os.Looper.loopOnce(Looper.java:232)
                 	at android.os.Looper.loop(Looper.java:317)
                 	at android.app.ActivityThread.main(ActivityThread.java:8705)
                 	at java.lang.reflect.Method.invoke(Native Method)
                 	at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:580)
                 	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:886)

androidx.media3.common.util.Assertions.checkState(Assertions.java:85) fails with check:
checkState(!newPeriodId.isAd());

Additional notes

this crash only happens for postroll (C.TIME_END_OF_SOURCE) advert. Preroll and midroll adverts are works fine without crashes

Media

Any mp4 video url, doesn't depend on specific video

Bug Report

• You will email the zip file produced by adb bugreport to android-media-github@google.com after filing this issue.

[marcbaechinger]

Thanks for your report and excellent description!

From the stack trace it looks like this is done with a controller, so your player in your code is actually a controller. Then when these three commands remove/add/seek arrive at the session, the post-roll is already playing which is why that assertion fails saying thre is an ad playing.

I was able to reproduce this with the demo app on first try following you description, by simply calling these three calls while the postroll is playing. I get a different stack trace because I don't go through the controller/session, but it crashes in the same way as you reported.

So this is certainly a bug as calling these methods must work during an ad as well. We'll investigate and we will update this issue when there are news. Thanks again for your report.

If you want to address this in your app without waiting on a fix, I think one thing you can do is stopping playback earlier. before the ad starts. I understand this is not a good user experience when the primary content has 2 secs left still or so. Not sure.

Another idea is deferring the removal. The exception is coming from the removeMediaItems(). You can experiment with a workaround that for instance first adds the new media items to the end of the playlist. Then seeks to the first of the newly added media items. Then when the playback transition is done you can to the removal of the media items that are still in the playlist with a lower index than the item currently being played. I haven't try that but if the problem is with removals only, this may be a hack to work around the isssue. (EDIT: I think this may not be possible as you can't seek during ad as per your other issue.)

I'll update here when we have something to update.

2025-09-08 15:17:13.801 10760-10760 AndroidRuntime          androidx.media3.demo.main            E  FATAL EXCEPTION: main (Ask Gemini)
    Process: androidx.media3.demo.main, PID: 10760
    java.lang.IllegalStateException
    	at com.google.common.base.Preconditions.checkState(Preconditions.java:497)
    	at androidx.media3.exoplayer.ExoPlayerImpl.maskTimelineAndPosition(ExoPlayerImpl.java:2613)
    	at androidx.media3.exoplayer.ExoPlayerImpl.removeMediaItemsInternal(ExoPlayerImpl.java:2543)
    	at androidx.media3.exoplayer.ExoPlayerImpl.removeMediaItems(ExoPlayerImpl.java:692)
    	at androidx.media3.demo.main.PlayerActivity.lambda$onCreate$0$androidx-media3-demo-main-PlayerActivity(PlayerActivity.java:129)
    	at androidx.media3.demo.main.PlayerActivity$$ExternalSyntheticLambda2.onClick(D8$$SyntheticClass:0)
    	at android.view.View.performClick(View.java:8209)
    	at android.view.View.performClickInternal(View.java:8186)
    	at android.view.View.-$$Nest$mperformClickInternal(Unknown Source:0)
    	at android.view.View$PerformClick.run(View.java:31889)
    	at android.os.Handler.handleCallback(Handler.java:1070)
    	at android.os.Handler.dispatchMessage(Handler.java:125)
    	at android.os.Looper.dispatchMessage(Looper.java:333)
    	at android.os.Looper.loopOnce(Looper.java:263)
    	at android.os.Looper.loop(Looper.java:367)
    	at android.app.ActivityThread.main(ActivityThread.java:9227)
    	at java.lang.reflect.Method.invoke(Native Method)
    	at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:566)
    	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:929)

[marcbaechinger]

This is fixed with the commit above that landed in the main branch.

I'm closing this issue. Please open a new issue if required.

[amorenkov]

Thank you for the quick response to the problem. We look forward to the fix in the new release. (for now we have ugly crash-save workaround which restricts switch to next media item on last 1 second of video content)