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

[Jan Schneider]

Zitat von Jean-Yves Avenard <jyavenard at gmail.com>:

> Hi
>
> On 6 November 2010 05:57, Dan Christensen <jdc at uwo.ca> wrote:
>> 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
>
> If the channel order is consistent when using LPCM ; it could very
> well be your amplifier ... Otherwise you can remap it easily with an
> alsa configuration.
>
> The way I test LPCM on my box is through the analog output ; and I can
> tell you it's correct.
>
> This PC is still running Ubuntu 9.10. Will probably upgrade to 10.04
> LTS at some stage : but as they say ; if it ain't broken.. And this is
> my main frontend.

This thread got me curious, so I've run your test videos on my FE. The  
MB is connected to the amplifier through S/PDIF, and the amp's  
internal speaker test assures that all speakers are working and  
connected correctly.
If I run the 5.1 test videos though, I don't get any sound from the  
surround (rear) speakers. MythTV is configured to use the digital alsa  
port, DD and DTS passthrough, upsampling of stereo.
I don't have a /etc/asound.conf file.
Any hints?

Jan.

-- 
Do you need professional PHP or Horde consulting?
http://horde.org/consulting/