[alsa-devel] Multistreaming Playback using Front Panel Headphone with realtek codec

[Takashi Iwai]

At Tue, 10 May 2011 14:42:45 +0800,
Raymond Yau wrote:
> 
> 2011/5/9 Takashi Iwai <tiwai at suse.de>
> 
> > At Sat, 7 May 2011 11:48:19 +0800,
> > Raymond Yau wrote:
> > >
> > > 2011/5/6 Takashi Iwai <tiwai at suse.de>
> > >
> > > >
> > > > >
> > > > > Use "Independent HP" just because patch_via.c already used it so it
> > is
> > > > > better to use a standard name for all hda codecs
> > > >
> > > > Yeah, I know.  But this name is confusing, so better to change in
> > > > patch_via.c as well.
> > > >
> > > >
> > > > Takashi
> > > >
> > >
> > > To force pulseaudio to get the correct subdevice for via codec, you may
> > need
> > > to add "subdevice 0" to HDA-intel.conf
> > >
> > > since subdevice 0 support multichannel but subdevice 1 only support
> > stereo
> > >
> > >
> > >     playback.pcm {
> > >         type softvol
> > >         slave.pcm {
> > >             type hw
> > >             card $CARD
> > > +          subdevice 0
> > >         }
> > >         control {
> > >             name "PCM Playback Volume"
> > >             card $CARD
> > >         }
> > >     }
> >
> > OK, fixed now.  Thanks.
> >
> >
> > Takashi
> >
> 
> But dmix still fail and you cannot use dmix with subdevice 1

Please elaborate.  You can use dmix with subdevice 1 when you write
your own config.  "front" definition is not for other but the primary
device.  It's no definition for every output device.

> >> I'd name it differently, e.g. "Headphone Stream Mode" taking "Slave" and
> "Independent", or such.  An enum with "ON" and "OFF" is no sensible choice.
> 
> The main point is how can the user find out which subdevice or device is
> used for "Headphone Stream"
> 
> Neither "aplay -l " nor "aplay -L' provide any useful information to the
> user

Yeah, because there is no standard definition for such streams.
We need to start from defining it at first.


Takashi