[mythtv-users] Simultaneous surround sound over HDMI and analog

[Jean-Yves Avenard]

Hi

On 23 January 2012 13:51, Daniel Osborne <myth at danielosborne.net> wrote:
> Until today, I was using only analog surround sound in mythtv.
> Since I finally got audio over HDMI working, I want to use it for normal TV
> watching.
> I only want to use the surround sound system for watching movies now
> (previously was used for all sound).
>
> I was able to get both digital and analog output simultaneously with an
> asoundrc I got from: http://forum.xbmc.org/showpost.php?p=418455&postcount=4
> However this only works with stereo sound. How can I change this to allow
> surround sound over analog (I don't really care how many channels are on
> HDMI, but downmix ideally atm)?

You won't be able to do this within mythtv

Why don't you create a plug device that sends all audio channels via
hdmi? the TV while only supporting stereo, should be able to do the
required downstream

You will never be able to do digital passthrough with this method.

But LPCM will work

>
> I've tried changing a few things, but when I try to test with speaker-test,
> it just gives me an error (typically):
> mythtv at dragon ~ $ speaker-test -c2 -r48000 -Dplug:both
>
> speaker-test 1.0.24.2
>
> Playback device is plug:both
> Stream parameters are 48000Hz, S16_LE, 6 channels
> Using 16 octaves of pink noise
> ALSA lib pcm_params.c:2162:(snd1_pcm_hw_refine_slave) Slave PCM not usable
> Broken configuration for playback: no configurations available: Invalid
> argument
> Setting of hwparams failed: Invalid argument

you're plug is a 6 channels audio device, you're trying to open it
with two channels.

it will not work

What is your definition of the plug device?