Vorbis dev - Jan 2013 - libao problem (Re: [alsa-devel] No dmix/dsnoop on Intel ICH4/5 by default?)

On 16-01-13 21:52, Clemens Ladisch wrote:
> Rene Herman wrote:
>> I'm out of touch of with alsa -- but should dmix/dsnoop still be
>> enabled by default on hardware that doesn't do hardware mixing?
>
> Yes.
>
>> I believe that it should be from /usr/share/alsa/cards/ICH4.conf,
>> but I don't get mixing on this setup when using the
"default"
>> pcm...
>
> What's the output of "aplay -v something.wav"?
I won't bother you with that, since things do in fact work with aplay. 
It seems I'm looking at a libao problem.

Specifically: I can mix as many streams as I want using just "aplay"
but
if I start by playing one track with "ogg123" (which uses a default, 
unconfigured libao as its backend), I can't start a second ogg123, which 
then says:

==ao_alsa WARNING: Unable to open surround playback.  Trying default device...
ALSA lib pcm_dmix.c:1018:(snd_pcm_dmix_open) unable to open slave
ao_alsa ERROR: Unable to open ALSA device 'default' for playback => 
Device or resource busy
ERROR: Cannot open device alsa.
==
I CAN still start an "aplay" at this point though. Moreover, things
get
weirder when I start with aplay. With one aplay running, I CAN start two 
additional ogg123 instances.

... so, err, ehm, err, what? :-)

This now seems at best related to ALSA in a secondary manner, and I'm 
CCing this to vorbis-dev (which I believe is the right email contact for 
libao?) but if you know of something of interest...

For vorbis-dev: this is on arch linux, (standard) kernel 3.6.11-1-ARCH, 
alsa-{lib,plugins,utils}-1.0.26-1, libao-1.1.0-2 and vorbis-tools-1.4.0-3.

Regards,
Rene

Rene Herman wrote:
> I can mix as many streams as I want using just "aplay" but if I
start
> by playing one track with "ogg123" (which uses a default,
unconfigured
> libao as its backend), I can't start a second ogg123, which then says:
>
> ao_alsa WARNING: Unable to open surround playback.  Trying default
device...
The default dmix is for stereo only.  For a surround dmix device, you'd
have to write your own definition.


Regards,
Clemens