How to set audio panning / balance / right left volume ?

[Gustl22]

I already searched the issues here, and in exoplayer repo.

Is there a way to set the right and left audio volume of a player. Or set balance or panning? Thx :)

[andrewlewis]

Not as a player API method, but this is possible to do via an audio processor - see https://github.com/google/ExoPlayer/issues/2659. We've submitted a ChannelMixingAudioProcessor that supports this internally and it will be on the main branch over the next few weeks, and should then go into the media3 1.1 release.

[Gustl22]

@andrewlewis is there any accessible way to set audio pan on the fly, see https://github.com/androidx/media/issues/797. I attempted this in this PR but I only got it working to set at the beginning, not on the fly.

[andrewlewis]

It isn't supported directly, but in theory I think it should be possible to get your PR to work.

I haven't looked into this recently, but at a high level the important things are:

• Make sure the audio processor is always active (so that DefaultAudioSink includes it in the active audio processors list and feeds it data)
• Ensure when you set a new matrix it gets applied from the next input buffer. You are probably setting the mixing matrix from a different thread from the one doing the audio processing, so I would mark the matrix setter and the method that uses the matrix as synchronized.
• Side note: it won't be possible to change the number of output channels like this, because that would require triggering reconfiguration of the audio processor which isn't supported.

If it still doesn't work, could you add some logging to see what matrix is being used in queueInput and make sure it's changing after you set a new matrix?