[mythtv-users] mythmusic iec958 help

Joe Henley joehenley at kc.rr.com
Sat Jul 5 15:22:01 UTC 2008


Gregg,

 From the posts above it doesn't look like it's going too well.  I 
continue to believe you will need to replace your sound card if you want 
to get 44.1KHz signals into your receiver.

Have you checked the SoundBlaster site (or googled) for clarification on 
what your specific card will do?  Allen's comments above about 
"sometimes spdif means upto 48KHz" is not 100%.  Sometimes it's 48KHz 
only; trust me, been there, done that.  ... and paid the return shipping 
for a limited capability card.

If your Soundblaster is not designed to output 44.1KHz via spdif, no 
tweaking of alsa parameters, etc. will help.

If your particular SB model will support 44.1KHz, then remove .asoundrc 
from /root , /home, and /etc, and anywhere else it resides.  IIRC, you 
have already removed PukeAudio, so from there you can start using 
alsamixer to unmute the iec958 items.

The most common (from what I read on sites like this) successful MythTV 
settings are:
Audio output device =  ALSA: spdif
Passthru output device = Default
Max audio channels = stereo (The 5.1 setting is currently broken. Use 
"stereo" and you'll still get 5.1 sound out of the system.)
Upmix = passive
Enable AC3 to SPDIF passthru = check
Enable DTS to SPDIF passthru = check
Enable internal volume controls = check
Mixer device = default
Mixer controls = Master

What will work for you is probably very similar to this.  If this 
doesn't work first time, then check the wiki for ways to determine good 
alternatives to "Audio output device = ALSA: spdif".  This setting seems 
to have several different incantations; and seems to be the one most 
people have to change.

Good luch, you _will_ eventually succeed,

Joe Henley


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