[mythtv-users] Problem playing some 5.1 audio.

[Jean-Yves Avenard]

Hi

On 31 March 2010 07:28, Joseph Fry <joe at thefrys.com> wrote:
> Ok... more testing and I still cannot get the sounds on my 5.1 channel AAC
> files to come out the correct speaker.

Would you have an 5.1 AAC test track ?

I wrote code for 0.22 to re-order the AAC channel but I didn't put it
in for the following reasons:
1- ffmpeg was supposed to have it fixed and the ffmpeg resync would
have made the fix available to mythtv
2- There are two very different ways AAC audio can be decoded in
mythtv. Using libfaad (which seems to be the default with many
distributions) or using ffmpeg build-in decoder. Both of them are
using different channel ordering (all of them wrong).
Originally ffmpeg used to present the channel order in the way it was
stored in the format; like
AC3: LFE L C R SL SR
WAV: L R C LFE SL SR
AAC: C L R SL SR LFE

Then they changed to always output the same ordering for all format except AAC..

MythTV and the new audio code introduced for 0.23 expect the channel
order to be the same for all format...

Re-ordering the channels isn't too complicated ; it's a matter of
doing the right re-order according to the right format *and* the
library used for the decoding...

If you have a 5.1 AAC test track, I can work on this ASAP and provide
a fix in time for 0.23 ...

Thanks
Jean-Yves