[mythtv-users] 5.1 surround sound and two mixer controls

[Achim Hofmann]

Achim Hofmann <news at achim-hofmann.com> wrote:
> Jean-Yves Avenard <jyavenard at gmail.com> wrote:
>> On 3 December 2010 08:51, Achim Hofmann <news at achim-hofmann.com> wrote:
>>> ..."Master" / "PCM" controls front left and front right speakers
>>> ..."Master Surround" controls center speaker, LFE, sub left and sub
>>> right speakers.
>>
>> Unfortunately, myth only supports PCM and Master ; it's a pretty
>> outdated mixer code something that will be done in 0.25
> 
> This is probably the wrong mailing list for asking such questions, but
> wouldn't it be possible to shift / redefine the "Master" mixer control
> to be responsible for all six channels using an own asoundrc
> configuration? I already read some howtos regarding alsa configurations
> but it seems to be really hard stuff. Maybe someone in this mailing list
> is literate with alsa configuration and could tell me how to do this?

I finally got it work using this alsa configuration:

/etc/asound.conf
pcm.softvol {
    type            softvol
    slave {
        pcm         "surround51"
    }
    control {
        name        "SoftVol"
        card        0
    }
}

Because MythTV setup woun't let you set these new output device and
mixer control, you'll have to set them directly in the database by hand:

update `mythconverg`.`settings` set data='ALSA:softvol' where
value='AudioOutputDevice';
update `mythconverg`.`settings` set data='SoftVol' where
value='MixerControl';

All other audio settings are the same as described in my initial mail.

Now my remote makes use of the new SoftVol mixer control which is
responsible for all six channels.

Regards,

Achim Hofmann