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

[Takashi Iwai]

At Thu, 26 Jun 2008 14:43:30 +0800,
<Ashwin.Chandra at corel.com> wrote:
> 
> Hello,
> I have found an issue with the mixer devices. I had been controlling
> only one elem, "LineOut", but there is another elem named "iSpeaker"
> which is the one that shows only left speaker active in alsamixer. I am
> not sure why I would need to control both of them. I would expect
> "Lineout" to be the master control. But anyway I can fix the problem in
> my application by un setting mute on the right channel at the beginning
> of the application.

Good to hear that you found out the culprit.

> Do you have any idea about this though? (or have seen this before)?

There have been similar bug reports, but your finding isn't unknown
(and thus important).

Could you run alsa-info.sh with --no-upload option for both working
and non-working cases, and attach the generated files?  The script is
found at
	http://www.alsa-project.org/alsa-info.sh


thanks,

Takashi

> 
> -----Original Message-----
> From: Takashi Iwai [mailto:tiwai at suse.de] 
> Sent: Wednesday, June 25, 2008 11:26 PM
> To: Ashwin Chandra
> Cc: alsa-devel at alsa-project.org
> Subject: Re: [alsa-devel] Alsa Issue - Sound playback starts on left
> speaker only
> 
> 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
> > > 
> > 
>