From LedHed's Wiki
Info'Italic text'rmation on enabeling S/PDIF output for MythTV
References http://www.mythtv.org/wiki/index.php/DigitalSoundHowTo
ASOUNDRC
Note: this is for a nForce2 soundcard
Create a file in your home directory (~/.asoundrc)
pcm.nforce-hw {
type hw
card 0
}
pcm.!default {
# type plug
# slave.pcm "nforce"
type hw
card 0
device 2
}
pcm.nforce {
type dmix
ipc_key 1234
slave {
pcm "hw:0,2"
period_time 0
period_size 1024
buffer_size 32768
rate 48000
}
}
ctl.nforce-hw {
type hw
card 0
}
MythTV Settings
General
Audio Output Device: ALSA:default
Note: This option is not available from the pulldown, it must be typed in
[ ] Enable AC3 to SPDIF passthrough
Note: Only check this if your tunner is encoding in AC3
Mixer Device: ALSA:default
Note: This option is not available from the pulldown, it must be typed in
Other Notes
Try to start with a clean modprobe.conf file. Remove any lines related to the soundcard. Reboot Then as 'root' run:
/sbin/alsaconf
Let it add the necessary lines to /etc/modprobe.conf
alsaconf is part of the alsa-utils package