[mythtv-users] digital audio wiki is wacky.

[Alen Edwards]

Peter Schachte wrote:
> Allen Edwards wrote:
> 
>> Assuming that the output of my ATSC capture is ac3, I want that to go
>> to both spdif and analog.
> 
> I don't think that's possible, at least I couldn't get that to work.  I 
> did get sound to come out of both TV (analog) and stereo (digital), but 
> the sound out of the TV was just noise.  Loud, speaker-blowing white 
> noise.  I inferred that it was passing the AC3 signal to the TV in 
> digital form (I did select pass-through, after all).  So I selected 
> digital output only for pass-through, and the TV keeps quiet.  
> Unfortunately, this throws off the family when they have the stereo off 
> and wonder why they're not getting sound.
> 
> Anyway, I'm attaching my .asoundrc file.  Works for me (Mythbuntu 8.04).
> 

Thanks for the reply.  I appreciate your help.

I ended up using this setup:

Audio output device:  ALSA:spdif
Passthrough output device:  ALSA:iec958:(AESO 0x02)
Max Audio Channels:  Stereo
Upmix: passive
Enable AC3 to SPDIF passthrough  CHECKED
Enable DTS to SPDIF passthrough  CHECKED
Use internal volume NOT CHECKED
Aggressive sound  NOT CHECKED

/etc/X11/asound.conf   REMOVED (or renamed)
~/.asouncrc   REMOVED  (or renamed)

and using two external decoders, one for 5.1 and one for 2.0 for the TV. 
  This gives me bit perfect spdif.  I found that using ALSA did not give 
bit perfect output because ALSA decodes, processes, then encodes, and is 
said to do a less than acceptable job on CD audio.

I do get 44.1KHz audio out from MythMusic and 48KHz audio out from MythTV.

I also use Mythbuntu 8.04.

Allen