[Question] HEVC video (without audio) not rendered in PlayerView

[Ethan1983]

Hello,

I'm playing a locally stored HEVC video track in MP4 container (it doesn't have any audio track) using ExoPlayer (media3 1.4.1) in Android 12L based AAOS. It plays fine after boot up, however subsequent play attempts tend to fail and PlayerView doesn't render any video frames. Upon debugging, AsynchronousMediaCodecCallback claims both availableInputBuffers and availableOutputBuffers to be empty and codec's callback onInputBufferAvailable and onOutputBufferAvailable aren't invoked.

MediaCodecRenderer's feedInputBuffer just keeps failing as it isn't able to dequeue an input buffer from platform's MediaCodec (c2.qti.hevc.decoder). Attaching debugger doesn't help as it changes timing and video renders fine.

So far, these workaround seems to help with successful video playback

• initialize player and prepare 100 milliseconds after activity's onStart

• or setup a MergingMediaSource and combine another mp4 having just an audio track of same length without any delay in activity's onState

  Can the team provide any pointers for debugging this?

[Ethan1983]

Unfortunately, wouldn't be able to share the video (closed source protected content). Added logs to AsynchronousMediaCodecCallback and MediaCodecRenderer in the demo app.

Codec has 4 input buffers for both success and failure case. However, has 12 output buffers for success case and just 3 for failing case. What can cause the codec to hold on to the output buffers and what could possibly cause the reduced output buffers for subsequent playback?

Note, can confirm, stop(), release(), flush() is all invoked as expected at the end of the every playback (finishing the activity).

[Ethan1983]

Also, MediaCodecRenderer::drainOutputBuffer queries the output buffer based on dequeued index. outputBuffer is of type java.nio.DirectByteBuffer.

      this.outputIndex = outputIndex;
      outputBuffer = codec.getOutputBuffer(outputIndex);

However, as per MediaCodec's documentation, it should have returned null when the codec is configured with an output surface (like ExoPlayer's PlayerView usage). Is this just an outdated documentation? Not to suggest it has anything to do this issue as java.nio.DirectByteBuffer is used for initial and subsequent playbacks.

[andrewlewis]

Is c2.qti.hevc.decoder the selected codec implementation for both the success and failure cases? Can you send a full bug report as requested in the issue template?

[Ethan1983]

Is c2.qti.hevc.decoder the selected codec implementation for both the success and failure cases? Can you send a full bug report as requested in the issue template?

Yes, same hardware decoder, just different instances. Sorry, wouldn't be able to share bugreport as it could leak proprietary info. However, if you are looking for something in specific for data points, should be able to check it at my end.

Also, didn't meant to raise it as an issue, just looking for some hat tips when dealing with MediaCodec stalls etc. It would have been nice if cases like these are exposed to Apps in a callback when there isn't any progress by the render thread.