[mythtv-users] mythmusic iec958 help

Alen Edwards allen.edwards at oldpaloalto.com
Sat Jul 5 16:08:49 UTC 2008



Joe Henley wrote:
> 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
I certainly agree with what is said above except for one small point, 
the Passthrough setting.  When I used the above setting, I heard 
terrible noise out the analog output.  I used the setting I think it is

passthrough = ALSA:iec958:{AES0 0x02}

If what Joe says doesn't work, try the above.

I just switched my Audio Output Device to ALSA:spdif and erased ascound.conf and my last sound problem went away.

Allen






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