[mythtv-users] HD-2000 doesn't record 5.1 surround (ac3) under myth 0.18.1 ?

[Brandon Beattie]

On Tue, Jan 17, 2006 at 08:32:07AM -0800, Tim Carr wrote:
> Hey all,
> 
> I've got my sound configured properly (I can play the dolby test .vob files
> and the passthru works, giving me 5.1 dolby digital to my receiver), but i'm
> having problems with myth.
> 
> If myth records "normal" HD tv with my ATSC tuner (PCHDTV-2000), it works
> fine, the sound goes over spdif as PCM/stereo.  But when I taped sunday and
> monday's 24 premieres which should have 5.1 ac3 sound, there's no sound! I
> checked by playing the .nuv files in Xine, which works fine with 5.1 sound
> from other test .vob files. Each 2 hour HD .nuv file is 8.4gb, which seems
> fairly small to me, I'm guessing the sound is missing completely (how to
> check?)
> 
> What do I have to do to my backend to get it to record 5.1 sound(ac3)
> properly?
> 
> My backend:
> Debian Sarge
> PCHDTV-2000 ATSC tuner using DVB driver from kernel 2.6.15
> (kernel 2.6.15)
> no sound card (it's a backend)

The HD tuner has nothing to do with it actually, it's how FOX handles
the audio subchannels.  Try hitting the + key to change which audio track
you're listening to.  I've had this happen dozens of times in the past,
and only with my local FOX station.  What's going on is FOX usually has
a 2 channel and 5.1 channel audio tracks.  I've seen fox broadcast
silence on the 2 channel or 5.1 channel depending if their source is
only one of them, not two.  Myth picks the first audio channel and if
it's the one with silence, that's what you get.

--Brandon