[mythtv-users] New spdif setup suggestions

[James Crow]

On Wed, 2009-02-11 at 08:23 -0700, Joel Means wrote: 
> On Wed, Feb 11, 2009 at 5:59 AM, James Crow <james at ultratans.com> wrote:
> > On Tue, 2009-02-10 at 19:05 -0800, Allen Edwards wrote:
> >
> > <snip>
> >>
> >> Can someone who has gotten HDMI audio to work help out here with the
> >> version numbers required as a minimum on alsa and nvidia drivers to
> >> get HDMI audio working?
> > <snip>
> >>
> >> Allen
> >>
> >
> > Allen,
> >
> >  I recently built a machine with Ubuntu Intrepid. The MB was an Asus
> > M2N68 with HDMI onboard. The integrated GPU is a 7050. I had to update
> > the included ALSA (1.0.17) to get HDMI to show in the list of available
> > audio outputs. I used the script that was references on this list from
> > ubuntuforums.org. It pulled the latest version from alsa-project.org
> > which was 1.0.19. The script is here:
> > http://www.ubuntuforums.org/showthread.php?p=6589810
> >
> >  The nvidia driver was the default that came with Intrepid. I think it
> > is 177.xx.
> >
> >  This was not built as a Myth system, but I was able to test mpeg2 ATSC
> > video through mplayer and audio was playing over the HDMI connection.
> >
> > Cheers,
> > James
> >
> >
> > _______________________________________________
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> > http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
> >
> 
> Just out of curiosity, was the audio ac3 using passthrough, or was it
> downmixed?  Or was it not ac3 at all (I think it usually is with ATSC,
> but I don't really know).  I have the same GPU on an Abit board and
> can't get passthrough to work on the HDMI port, but regular audio
> does.
> Thanks,
> 
> Joel

I had a 1080i file from the presidential inauguration recorded by clear
QAM from my local NBC affiliate. The audio is ac3. This is the line I
used to play the file:

mplayer -ao alsa:device=hw=0.3 -vf pp=fd 4032_20090120114500.mpg

I did no other configuration except to check that the iec958 device was
not muted. The xorg.conf file is stock Ubuntu 8.10 with the distro
supplied 177.xx nvidia binary. The '-vf pp=fd' part of the command is a
deinterlacer. The first time I played the 1080i video on the attached
37" 1080p LCD display it looked terrible.

I am not very familiar with mplayer options, but I would guess that it
decoded the ac3 audio before sending it out the HDMI port.

I no longer have the HDMI device and this PC is about to leave for its
final home as part of a digital billboard so I do doubt further testing
will be possible.

Cheers,
James