[alsa-devel] 5.1 to stereo using libasound

Hi,

I am playing a mkv with 5.1 channels from a mkv. I configure libasound for 6 channels and I feed them interleave audio using snd_pcm_writei. I use the default pulse audio device.

So far, nothing is wrong. However, I do not ear things correctly. I listen this on my stereo speaker. There is no mixdown to stereo and I was wondering how to do that. I tried to use chmap api but anything I try on the default device returns an error.

I was wondering what was the correct way to do that? Using the mixing api? How do we detect that my device output stereo if chmap doesn't work?

I am on a ubuntu 18.04 linux box.

Thanks, Eric