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