[alsa-devel] Alsa Issue - Sound playback starts on left speaker only

[Takashi Iwai]

At Thu, 26 Jun 2008 03:28:42 +0800,
<Ashwin.Chandra at corel.com> wrote:
> 
> Hi Takashi,
> Actually now I am noticing the problem (left speaker only) with
> mplayer/smplayer in their OSS emulation as well. It seems to happen once
> I run my player first, then after that the other players exhibit the
> problem.

In this case, mplayer will choose the ALSA mode automatically, I
guess.  So the problem appears to be ALSA-mode specific, possibly
about dmix.

Try to define the following in ~/.asoundrc:
    pcm.!default "plughw"

then it won't use dmix as default any more.  (Then you can use only
one app at the same time, of course.)  Check whether the problem can
be reproduced with this setting.


Takashi


> Sometimes after muting and unmuting my player, the problem goes
> away and also away on the players. It is almost like my player is
> causing bad internal state for the audio driver. Do you have any
> suggestions to work around this?
> 
> -----Original Message-----
> From: Takashi Iwai [mailto:tiwai at suse.de] 
> Sent: Wednesday, June 25, 2008 3:23 AM
> To: Ashwin Chandra
> Cc: alsa-devel at alsa-project.org
> Subject: Re: [alsa-devel] Alsa Issue - Sound playback starts on left
> speaker only
> 
> At Wed, 25 Jun 2008 01:52:16 +0800,
> <Ashwin.Chandra at corel.com> wrote:
> > 
> > I have an Intel ALC861VD. Other players (mplayer, smplayer, aplay)
> don't
> > seem to exhibit this problem. Is there any workaround I can do in my
> > application so that upon first time sound playback, I can get it to
> play
> > on both channels?
> 
> Check /proc/asound/card0/pcm0p/sub0/* files and compare between
> working and non-working states.  I guess the working case uses OSS
> emulation or 16bit format.
> 
> If so, try to add the following to ~/.asoundrc:
> 
>   defaults.pcm.dmix.format S16_LE
> 
> 
> Takashi
> 
> > 
> > -----Original Message-----
> > From: stan [mailto:ghjeold_i_mwee at cox.net] 
> > Sent: Tuesday, June 24, 2008 1:25 AM
> > To: Ashwin Chandra
> > Cc: alsa-devel at alsa-project.org
> > Subject: Re: [alsa-devel] Alsa Issue - Sound playback starts on left
> > speaker only
> > 
> > Ashwin.Chandra at corel.com wrote:
> > >  
> > >
> > > Hello,
> > >
> > > I am having an issue with my playback application where upon
> playback
> > > start, only the left speaker is outputted. But if I mute and unmute
> > > (either through my application or using alsamixer), the sound
> playback
> > > resumes on both left and right speakers. This only happens on a
> > > particular system too (out of 5 systems). But I know it is my issue
> > > because mplayer or smplayer works fine.
> > >
> > >  
> > >
> > > I believe I am setting the correct HW params (ie. 2 channels), etc.
> > >
> > >  
> > >
> > > Any ideas?
> > >
> > >  
> > >
> > > Thanks!
> > >
> > >   
> > The ICE1724 driver has exactly this behavior.  It is a known bug and
> has
> > 
> > been there for years.
> > You don't say what chip is having the problem, but I would guess that 
> > this is it.  Most people
> > just program a script to adjust the volume at startup to cure it.
> > _______________________________________________
> > Alsa-devel mailing list
> > Alsa-devel at alsa-project.org
> > http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
> > 
>