[pulseaudio-discuss] PulseAudio and 5.1 sound

[Lennart Poettering]

On Wed, 31.10.07 22:30, Ira Snyder (devel at irasnyder.com) wrote:

> Hello all. I'm having trouble with 5.1 sound and pulseaudio.
> 
> I'm using gentoo ~x86, and PA 0.9.7. I have an Audigy2 ZS soundcard, which uses the emu10k1 driver in ALSA.
> 
> I had 5.1 sound working in PA 0.9.6 with the following line in my /etc/pulse/default.pa file:
> load-module module-alsa-sink device=surround51 channels=6
> 
> Now, with PA 0.9.7, it doesn't recognize the device at all. It gives me the following error message:
> ALSA lib control.c:909:(snd_ctl_open_noupdate) Invalid CTL
> surround51

This is no error. Only a warning that no matching mixer for your PCM
could be identified and PA thus reverted to software volume control.

Please provide me with the full output of pulseaudio -vv.

> However, 6 channel sound with plain ALSA is working, as it has been
> for a long time. I confirmed this by running "speaker-test
> -Dsurround51 -c6 -l1 -twav" which works wonderfully. I can also use
> "-Dplug:surround51" and it gives me the same, working 5.1 sound.
> 
> So, my question is: why can't pulseaudio open the "surround51"
> device?

surround51:0 is the device you should be opening. And PA should be
able to do just that.

EMU10K is somehwat strange as it seems. It combines several
synchronized stereo outputs into a single surround output. To make
that work ALSA uses the userspace "multi" ALSA plugin, which apparently has
some issues.

Lennart

-- 
Lennart Poettering                        Red Hat, Inc.
lennart [at] poettering [dot] net         ICQ# 11060553
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