[pulseaudio-discuss] Alsa output devices, able to use alsa plugin?

[Tanu Kaskinen]

ke, 2009-08-26 kello 16:48 +0800, Ng Oon-Ee kirjoitti:
> That's interesting, and I'll look into it in future perhaps. For now,
> I'm more interested to find out why this doesn't work on my system. It
> may be a more general problem, as I was trying such outputs as:-
> 
> pcm.test {
>   type plug
>   slave { pcm "hw:0,0" }
> }
> 
> Which should work, since it doesn't even do anything. I get the same
> error message trying to load it up though. Could somebody test this out
> (just have the above in your .asoundrc and try to use 'test' as the
> device for module-alsa-sink.

Indeed, it doesn't work. This is the log output:

D: alsa-util.c: Trying test with SND_PCM_NO_AUTO_FORMAT ...
D: alsa-util.c: Managed to open test
D: alsa-util.c: Maximum hw buffer size is 371 ms
I: alsa-util.c: snd_pcm_hw_params_set_periods_near() failed: Tiedostoa tai hakemistoa ei ole
I: alsa-util.c: snd_pcm_hw_params_set_buffer_size_near() failed: Tiedostoa tai hakemistoa ei ole
D: alsa-util.c: Trying test without SND_PCM_NO_AUTO_FORMAT ...
D: alsa-util.c: Managed to open test
D: alsa-util.c: Maximum hw buffer size is 371 ms
I: alsa-util.c: snd_pcm_hw_params_set_periods_near() failed: Tiedostoa tai hakemistoa ei ole
I: alsa-util.c: snd_pcm_hw_params_set_buffer_size_near() failed: Tiedostoa tai hakemistoa ei ole
D: alsa-util.c: Trying plug:test with SND_PCM_NO_AUTO_FORMAT ...
D: alsa-util.c: Managed to open plug:test
D: alsa-util.c: Maximum hw buffer size is 371 ms
I: alsa-util.c: snd_pcm_hw_params_set_periods_near() failed: Tiedostoa tai hakemistoa ei ole
I: alsa-util.c: snd_pcm_hw_params_set_buffer_size_near() failed: Tiedostoa tai hakemistoa ei ole
D: alsa-util.c: Trying plug:test without SND_PCM_NO_AUTO_FORMAT ...
D: alsa-util.c: Managed to open plug:test
D: alsa-util.c: Maximum hw buffer size is 371 ms
I: alsa-util.c: snd_pcm_hw_params_set_periods_near() failed: Tiedostoa tai hakemistoa ei ole
I: alsa-util.c: snd_pcm_hw_params_set_buffer_size_near() failed: Tiedostoa tai hakemistoa ei ole
I: alsa-util.c: Failed to set hardware parameters on plug:test: Tiedostoa tai hakemistoa ei ole
E: module.c: Failed to load  module "module-alsa-sink" (argument: "device=test"): initialization failed.

That "Tiedostoa tai hakemistoa ei ole" error means "No such file or
directory". I tried also with device=hw:0,0 and device=plughw:0,0 and
the first worked while the latter gave the same errors. Since the failed
function calls pertain to buffering, I also tried with tsched=0. It
worked. So, maybe this is a bug in the "plug" alsa plugin, ie. it
doesn't implement the *_near() functions properly.

Lennart, any insights?

-- 
Tanu Kaskinen