[mythtv-users] Static noise over AC3 passthrough

[Michael T. Dean]

On 05/30/06 19:57, Justin The Cynical wrote:

>Eric Smith wrote:
>  
>
>>I'm hoping this issue is a minor one that I am just over-looking but I
>>can't seem to figure it out.  I can't get AC3 passthrough to work
>>(through mplayer, xine, or myth).  In each case whenever I enable AC3
>>I get a horrible pulsating static sound through my receiver and the
>>auto detection on the receiver never changes from 2 channel.  Hardware
>>wise, I've had the same setup outputting AC3 on a Windows box in the
>>past so I'm fairly sure its not a hardware issue.  Any thoughts would
>>be greatly appreciated.
>>    
>>
>I had this issue as well.  Alsa/Myth was sending the AC3 data through 
>the filter and not to the receiver directly.  To fix it, I had to change 
>the audio output to ALSA:spdif, or turn off the AC3 passthrough.  I used 
>the spdif output choice.
>
>This, of course, broke myth music for me, as it didn't run the mp3 data 
>through the resample filter.  I've not gotten around to fixing it yes, 
>as getting the AC3 working for the digital broadcasts was more important 
>to me.
>

Yeah.  It's sounding like the automatic conversion plugin is 
interpreting the signal.  I guess that means you can use the digital 
output alias defined by your card definition (i.e. "spdif" or "iec968") 
or just use "digital-hw" for the same effect (but without having to 
figure out which alias is appropriate for your card).

Mike