[mythtv-users] ac3 passthrough problems

[Scott]

On Sep 30, 2006, at 4:57 PM, Richard Krehbiel wrote:

> I'm building a mythtv system now (about as slowly as anyone  
> possibly can), and I'm stumped on the S/PDIF problem.
>
> I have an MSI K9NGM2-FID - Socket AM2, nVidia GeForce 6150, and I'm  
> using on-board sound with Intel HDA drivers (snd-intel-8x0).  I  
> installed Fedora Core 5, current updates.  I've got a coax from my  
> S/PDIF out to my Onkyo 304, and Onkyo set to consume coax.  (It  
> works from an actual DVD player.)

Find a .wav file on your system. Check /usr/share/sounds/alsa/ and  
look for something like "Front_Left.wav". Then try "aplay -D spdif / 
usr/share/sounds/asla/Front_Left.wav" and see if you get any output  
at all.

> I haven't done any alsa configuration.  I looked into it, but  
> frankly alsa is impenetrable  (is there a good doc?  I haven't seen  
> one) - plus I've read comments saying it should work out of the box.

At the very least run "alsamixer" and make sure that your PCM is  
unmuted and set to a reasonable volume. Also look for an iec958  
device and make sure it is unmuted as well.

> I've got a DVD in right now.  I'll play it:
> mplayer -v -ao alsa -afm hwac3 -monitoraspect 16:9 -dvd-device /dev/ 
> cdrom dvd://1

Try this mplayer command again after you have:

1) Run alsamixer as directed above
2) Verified that aplay can generate some sounds for you

If these steps don't help you post the output for the commands "aplay  
-l" and "aplay -L".

--
Scott