[alsa-devel] How to choose output channels for AD1386A sound?

[Takashi Iwai]

At Mon, 21 Apr 2008 10:45:51 +0300,
Ihar Hrachyshka wrote:
> 
> On Thu, Apr 17, 2008 at 2:57 PM, Takashi Iwai <tiwai at suse.de> wrote:
> > At Thu, 17 Apr 2008 10:27:59 +0000,
> >
> > Ihar Hrachyshka wrote:
> >  >
> >  > Hello!
> >  > I build my BF533-EZKIT-based board (Blackfin processor development
> >  > board) sound system on AD1386A sound. I use blackfin.uclinux.org
> >  > distribution for it. One of my board's function is to play three
> >  > different stereo sound streams simultaneously on it. What I done is
> >  > choosing for AD1386 '3 stereos' option. After loading the kernel, my
> >  > software is able to open pcm 3 times and plays sound properly, with no
> >  > glitches or smth. The only missed functionality is that I can't
> >  > specify the needed subdevice I want to play a stream on. I should have
> >  > the possibility to play, f.e., mplayer stream on the 3rd stereo output
> >  > while the 1st and the 2nd are not used. How can I do it?
> >
> >  You can pass three numbers to PCM arguments: card, device and
> >  subdevice.  For example, the below will choose card = 0, device = 2,
> >  subdevice = 1, i.e. the secondary substream:
> >         % aplay -Dplughw:0,2,1
> That's what I've done:
> 
> # arecord -c 2 -f dat -d 30 a.wav
> # aplay -Dplughw:0,0,0 a.wav
> ALSA sound/blackfin/ad1836.c:924: snd_ad1836_playback_open
> Playing WAVE 'aAwLvS A  isnodu1n di/ biltaecEkdfai,nR/ta d8108 3z6 .tcr:o1
> 
>    046: snd_ad1836_hw_free
> ALSA lib ../../../alsa-lib-1.0.12-svn-rev6478/src/pcm/pcm_plug.c:773:(snd_pcm_plug_hw_refine_schange)
> find an usable access for 'plughw:0,0,0'
> aplay: set_params:904: Sample format non available

The problem seems different.  I guess you can't run with 'plughw:0' as well?
According to the message, the sample format isn't available although
wrapped with plug layer.  Did you install all alsa-lib plugins
properly?  If you don't pass any configure options, all plugins should
be built.


Takashi

> 
> # arecord -c 2 -f S32_LE -d 30 a.wav
> # aplay -Dplughw:0,0,0 a.wav
> ALSA sound/blackfin/ad1836.c:924: snd_ad1836_playback_open
> Playing WAVEA'L.SaA' :sSoguen d2/bbtlLatclk fniinn/ aade18803 6z. ct:r1o0
> 
>   46: snd_ad1836_hw_free
> ALSA lib ../../../alsa-lib-1.0.12-svn-rev6478/src/pcm/pcm_plug.c:773:(snd_pcm_plug_hw_refine_schange)
> to find an usable access for 'plughw:0,0,0'
> aplay: ../../aplay/aplay.c: 919: set_params: Assertion `err >= 0' failed.
> Aborted by signal Aborted...
> 
> Though ALSA shows that I have 3 subdevices it doesn't work with
> plughw:0,0,0..2. What else can I do to iinvestigate the problem?
> >
> >
> >  > Also that would be great if I can optionally play the same stream on
> >  > all the outputs.
> >
> >  You'll need to define a PCM with multi plugin.
> >
> >
> >  Takashi
> >
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