[mythtv-users] how to tell if 5.1 audio channels mapped correctly?

[Dan Christensen]

Dan Christensen <jdc at uwo.ca> writes:

> Jean-Yves Avenard <jyavenard at gmail.com> writes:
>
>> A great deal of time was spent getting the channel ordering right in
>> mythtv.
>
> That's good.  I've only found a few test files that also had video, but
> they all worked right for me in myth except for one, and I think that
> one was made incorrectly.

Well, there's good news and bad news.  The good news is that I now see
the pattern.  Whenever I get digital passthrough to work with a piece
of software (myth AC3/DTS, mplayer DTS and xine DTS), the playback is
correct.  But whenever I don't use digital passthrough, the playback
is wrong, including with mythtv!  For example, with 

  http://www.avenard.org/files/media/videotest/audiotest/idch_AviaSurroundTest-DTS.mkv

played back in myth without digital passthrough, the center and left
surround channels are swapped, and it sounds like the LFE and right
surround channels are swapped too (but I don't have a subwoofer, so
it's harder to tell).

So now it looks like I have a systematic problem with channel mappings.

Could it be because the version of alsa I'm running is older than yours?
I'm running Debian lenny with these alsa versions

alsa-base           1.0.23+dfsg-2  ALSA driver configuration files
alsa-source         1.0.23+dfsg-2  ALSA driver sources
alsa-utils          1.0.23-3       Utilities for configuring and using ALSA
alsaplayer-alsa     0.99.80-3      PCM player designed for ALSA (ALSA output module)
alsaplayer-common   0.99.80-3      PCM player designed for ALSA (common files)

and kernel 2.6.32-5-686.  Maybe next week I'll try upgrading to
testing/squeeze to see if that fixes anything, but that's a major
upgrade that I'm hesitant to do if it's not necessary...

What happens for you with that clip without digital passthrough?  What
does "speaker-test -twav -c6" do?

Thanks for all of the help!

Dan