[alsa-devel] Adding ELD control to alsa-lib hdmi device

Pierre-Louis Bossart pierre-louis.bossart at linux.intel.com
Mon Sep 26 19:59:42 CEST 2011

> I'm not the expert here, but if I were you, I would run
> amixer -D hw:x contents
> amixer -D hw:x scontents
> To see if your controls show up there. If it shows up in scontents, that 
> would be the "simple" mixer interface that PulseAudio uses. If not, 
> using the control api (as being done by "contents") should work.
> Anyway, reading the source code to amixer would then be the first step 
> towards understanding how to enumerate and read mixer controls.

That part was done already. I was looking at PulseAudio integration. By
looking at additional source code, I found out I could retrieve the card
and device number with snd_pcm_info_get_card() and
I can now read the ELD control from PulseAudio, all I need is to add the
ELD parsing and set the codecs supported by the receiver accordingly.

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