[alsa-devel] dmix problems with analog out (HDMI out works fine with dmix)
tiwai at suse.de
Thu Sep 29 14:32:01 CEST 2011
At Thu, 29 Sep 2011 08:22:39 -0400,
Robert Krakora wrote:
> On Thu, Sep 29, 2011 at 2:36 AM, Takashi Iwai <tiwai at suse.de> wrote:
> > At Wed, 28 Sep 2011 12:29:05 -0400,
> > Robert Krakora wrote:
> > >
> > > Hi All,
> > >
> > > I am using ALSA 1.0.24 with the attached asound.conf. I am attempting to
> > > share (mix) the analog output between Asterisk and aplay. However, when
> > > Asterisk is running, my application throws an error when attempting to
> > play
> > > a wave file via aplay. If I stop Asterisk, aplay plays the wave file
> > just
> > > fine. If I remove the asound.conf file, Asterisk and aplay are both
> > happy
> > > and share the analog output just find with the default ALSA dmix
> > > implementation. However, we need this asound.conf to work for us for
> > other
> > > reasons. What is wrong with it. I have even tried replacing dmix with
> > > dshare and get the same bad behavior. We are running CentOS 6.0. As a
> > > caveat, I am attempting to use dmix with analog audio. If I use it with
> > > HDMI audio, it works flawlessly (same asound.conf with tweek to specify
> > > HDMI). Thanks in advance for your help.
> > >
> > > [root at devkrakorar snd]# su silentm -c "aplay -Dplug:dmixer
> > > /usr/share/sounds/alsa/Front_
> > > Center.wav"
> > > ALSA lib pcm_hw.c:1293:(snd_pcm_hw_open) open '/dev/snd/pcmC0D0p' failed
> > > (-22): Invalid argument
> > >
> > > ALSA lib pcm_dmix.c:1068:(snd_pcm_dmix_open) unable to open slave
> > > aplay: main:660: audio open error: Invalid argument
> > > [root at devkrakorar snd]#
> > Looks like the open of HD-audio stream failed by some reason.
> > When you open via aplay, is the corresponding stream already opened
> > by another? Take a look at /proc/asound/card0/pcm0p/sub0/* files.
> > Also, try the latest alsa-driver snapshot in
> > ftp://ftp.suse.com/pub/people/tiwai/snapshot/
> > Takashi
> Hi Takashi,
> Thanks for the quick response. Yes, the HD-audio stream open fails because
> Asterisk has previously opened it. aplay cannot open it (error -22).
-22 is -EINVAL, and it's not -EBUSY or -EAGAIN. If a blocking open is
the problem, it should have been -EAGAIN or such.
That is, usually something conflicts with the opened stream.
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