New snd_hda driver came in.

Alexander Motin mav at
Sat Sep 13 18:37:43 UTC 2008

Alexander Leidinger wrote:
>> New driver supports digital PCM playback and AC3 pass-through. I am not 
>> sure about completeness of this implementation, but I have several 
>> success stories including my own. Vchans subsystem does not support AC3 
>> pass-through so it had to be disabled for that devices at this moment.
> As vchans is our internal many-to-one (physical output) mixer, and the
> fact that digital out can be anything (PCM, AC3, ...) I think a
> sensible default for vchans would be to ignore digital interfaces. I
> don't know if this is easy to do or not.

As soon as AC3 is a separate stream format and vchans has info about it, 
better solution would be to make vchans mute other streams, switch 
hardware device to the AC3 stream sample rate and pass it though. For 
usual PCM streams in such case mixing would work as before, that would 
be good.

Alexander Motin

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