[MPlayer-dev-eng] [PATCH 2/2] alsa: Better volume control handling, especially for S/PDIF.

[Reimar Döffinger]

On Sun, Apr 06, 2014 at 03:36:28PM +0200, Ingo Brückl wrote:
> Reimar Döffinger wrote on Sat,  5 Apr 2014 14:53:03 +0200:
> 
> > If no mixer channel was specified and PCM does not exist, just
> > pick the first.
> > If no volume control is available, at least support mute and full
> > volume switching if a playback switch exists.
> > This is also useful for being able to unmute S/PDIF devices.
> 
> I can't detect any different behaviour here, but maybe I don't fulfil the
> conditions.

Well, if your device is unmuted from the start, the difference will be
that a simple mute/unmute will not insert the volume filter.
(Though if you were to use a full soundcard with both spdif and
normal output, you could have had any effect, e.g. it might have
had working volume control or you might have gotten no volume control
at all)
But if you (e.g. using alsamixer) mute the spdif device you should
notice that there was no way to make it produce sound using MPlayer
before.
Now just pressing 'm' twice will make it work.
Unfortunately I can't test it, but I also suspect that by moving the
AC3 special-case for volume control this patch should also allow
muting AC3 streams.