Version

Media3 main branch

More version details

All

Devices that reproduce the issue

All

Devices that do not reproduce the issue

n/a

Reproducible in the demo app?

Yes

Reproduction steps

1. Launch the Media3 demo app.
2. Start playing any video asset use video decoder Extensions such as decoder_av1 .
3. As soon as Player.COMMAND_SEEK_IN_CURRENT_MEDIA_ITEM becomes available (media is loading but not yet rendering output), immediately perform a seek operation inside the media.

Expected result

• Seeking should be safe and exception-free as long as
  Player.COMMAND_SEEK_IN_CURRENT_MEDIA_ITEM is available.
• Playback should continue normally after the seek when using decoder extensions.

Actual result

Player crash:

androidx.media3.exoplayer.ExoPlaybackException: Unexpected runtime error
  at androidx.media3.exoplayer.ExoPlayerImplInternal.handleMessage(ExoPlayerImplInternal.java:921)
  at android.os.Handler.dispatchMessage(Handler.java:106)
  at android.os.Looper.loop(Looper.java:219)
  at android.os.HandlerThread.run(HandlerThread.java:67)
Caused by: java.lang.NullPointerException
  at com.google.common.base.Preconditions.checkNotNull(Preconditions.java:904)
  at androidx.media3.exoplayer.video.DecoderVideoRenderer.processOutputBuffer(DecoderVideoRenderer.java:882)
  at androidx.media3.exoplayer.video.DecoderVideoRenderer.drainOutputBuffer(DecoderVideoRenderer.java:832)
  at androidx.media3.exoplayer.video.DecoderVideoRenderer.render(DecoderVideoRenderer.java:221)
  at androidx.media3.exoplayer.RendererHolder.render(RendererHolder.java:392)
  at androidx.media3.exoplayer.ExoPlayerImplInternal.doSomeWork(ExoPlayerImplInternal.java:1378)
  at androidx.media3.exoplayer.ExoPlayerImplInternal.handleMessage(ExoPlayerImplInternal.java:707)
  at android.os.Handler.dispatchMessage(Handler.java:106) 
  at android.os.Looper.loop(Looper.java:219) 
  at android.os.HandlerThread.run(HandlerThread.java:67)

Media

In processOutputBuffer(long positionUs, long elapsedRealtimeUs), the outputFormat is resolved as follows:

• processOutputBuffer is not called so outputFormat is null
• formatQueue.clear() is called
• inputFormat may remain unchanged
• onInputFormatChanged(FormatHolder formatHolder) is not triggered
  As a result:
• formatQueue remains empty
• Both pollFloor() and pollFirst() return null
• outputFormat is never set
• A subsequent checkNotNull(outputFormat) causes a crash

Suggested Fix: After onPositionReset, the next input sample must be treated as the first sample of the current Format, even if the format itself did not change.
This can be ensured by updating onPositionReset to include:

formatQueue.clear();
waitingForFirstSampleInFormat = true;

Bug Report

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