[alsa-devel] [Q] playing / recording mono on a stereo-only hardware

[Guennadi Liakhovetski]

(re-adding the list)

On Tue, 2 Feb 2010, Michael Trimarchi wrote:

> Hi,
> 
> Guennadi Liakhovetski wrote:
> > On Sat, 30 Jan 2010, Michael Trimarchi wrote:
> > 
> >   
> > > Guennadi Liakhovetski wrote:
> > >     
> > > > Hi
> > > > 
> > > > I know this question belongs rather to alsa-users, and I did ask it
> > > > there,
> > > > but got no solution so far. Maybe someone here can help.
> > > > 
> > > > The recently posted SuperH SIU driver only supports stereo playback and
> > > > capture (channels_min = channels_max = 2). Is there a way to tell
> > > > alsa-lib
> > > > to duplicate the mono-channel during playback and to mix recorded
> > > > channels
> > > > (or use one of them), if mono recording is requested?
> > > >         
> > > I'm not an expert but I think that you can use plughw support of alsa-lib
> > > 
> > > pcm.record {
> > >       type plug
> > >       slave {
> > >               pcm record_hw
> > >       }
> > >       route_policy average
> > >       rate_converter "linear"
> > > }
> > > 
> > > I think that automatically change rate and channel for supporting mono
> > > channel
> > > too
> > >     
> > 
> > Thanks for the snippet, but, I'm afraid, it didn't help either.
> >   
> Sorry can you explain a little bit more why it doesn't help you?

I certainly gladly would explain this, if only I knew... It just doesn't 
change anything. Are you using it anywhere? If yes, with which hardware 
configuration and software (alsa-lib) versions?

Thanks
Guennadi
---
Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer
http://www.open-technology.de/