5.1 surround with CA0106 using IEC958 - Kubuntu Karmic

[garthecho]

Just beating my head against a wall lately trying to enable 5.1 surround through the digital out (spdif) of my Audigy SE card. It outputs fine to stereo right now, but watching a DVD with 5.1 selected in any media player (VLC, Totem, Mplayer etc.) still yields stereo output.

I've searched far and wide for a solution with no luck yet.

Just curious if someone with a similar setup has had any luck.

[Sin@Sin-Sacrifice]

Is vlc, mplayer, and totem set to 5.1?

[garthecho]

Oh yeah. I've tried what seems like every audio combination I can find. Ideally, I would like to be able to set them all to AC3 passthrough, but that option gives me silence.

[garthecho]

Just to give more info, here's the result of "speaker-test -Dplug:surround51 -c6 -l1 -twav"


Playback device is plug:surround51
Stream parameters are 48000Hz, S16_LE, 6 channels
WAV file(s)
Rate set to 48000Hz (requested 48000Hz)
Buffer size range from 32 to 16384
Period size range from 16 to 8192
Using max buffer size 16384
Periods = 4
was set period_size = 4096
was set buffer_size = 16384
0 - Front Left
4 - Center
1 - Front Right
3 - Rear Right
2 - Rear Left
5 - LFE
Time per period = 8.364022


With this I hear only the front left and right channels.

Also I'm using pulseaudio, so I have modified /etc/pulse/daemon.conf and uncommented and changed "default-sample-channels" to be set for 6 instead of 2.

[garthecho]

Well, I guess this is a tough one. If I figure this out I will make sure to post back here for the people with this hardware that want digital 5.1.

Until then, any advice or experiences are very welcome.

[Sin@Sin-Sacrifice]

Toyed around with it and I found the sample channel conf in /etc/pulse/daemon.conf where I uncommented it and changed the 2 to 6 (well... 5.1 first. That didn't work at all.). You can test it out with

speaker-test -Dplug:surround51 -c6 -l1 -twav

.

[garthecho]

Thanks for the tip, but for some reason making that change doesn't help me. I only hear the front left and right channels with the test. Is your setup hooked up digitally? I'm starting to think it would probably work in analog mode, but I would like to keep my card hooked to my amp through the spdif. I know the card is capable of this, as it works in another "proprietary OS" I'm forced to use occasionally .

[grege]

You could try installing Gnome-alsamixer and check the preference and make sure all the channels are visible. then ...

make sure all the volumes are turned up for the various channels.

I use an M-Audio Revolution5.1 so I cannot be more specific.

[jocko]

The problem is that pulseaudio is not capable of spdif passthrough (there's this two years old open bug on it).
With mplayer you should get passthrough of dolby and dts by using alsa as output, and hwac3 as codec family. From a command line:

mplayer -ao alsa -afm hwac3 filename

In vlc, setting the sound to alsa and enabling the "use spdif if available" and "force detection of dolby surround" should do it.

Just note that as this uses alsa directly, it won't work if pulseaudio is already playing some sound (and while mplayer or vlc plays surround sound, pulseaudio won't work).

[garthecho]

Thanks jocko, I was unaware of that bug. Doesn't look too hopeful.