[alsa-devel] dmix problems with analog out (HDMI out works fine with dmix)
rob.krakora at messagenetsystems.com
Thu Sep 29 14:22:39 CEST 2011
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
> > a wave file via aplay. If I stop Asterisk, aplay plays the wave file
> > fine. If I remove the asound.conf file, Asterisk and aplay are both
> > and share the analog output just find with the default ALSA dmix
> > implementation. However, we need this asound.conf to work for us for
> > 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
Thanks for the quick response. Yes, the HD-audio stream open fails because
Asterisk has previously opened it. aplay cannot open it (error -22).
However, dmix should remedy the situation. It should provide software
mixing for Asterisk and aplay so that the output of both is mixed and output
to the analog audio channel. I will try your latest drivers.
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