[MPlayer-users] Re: H264/AAC in MKV: Wrong channel mapping [Was: Quicktime sound atom v2: Wrong audio channel mapping]

[Corey Hickey]

Frank Aurich wrote:
>> Yes, you are right. When I dug deeper, I found that the channel mapping 
>> was coming from the AAC decoder rather than from the MOV demuxer.
>>
>> The problem isn't really a problem like a bug; it is evidence of a lack 
>> of foresight on the part of whoever designed the audio formats. There 
>> are many, many different types of multichannel audio and no standard for 
>> how to order the channels. Consequently, AAC is different from AC3 and 
>> other formats are probably different still.
>>
>> Since MPlayer's channel ordering is designed around AC3, it doesn't 
>> handle AAC correctly. I wrote a proof of concept patch quite a while ago:
>>
>> http://mplayerhq.hu/pipermail/mplayer-dev-eng/2006-February/040764.html
>>
>> Please test it. I'll try to find some time later to re-do the patch 
>> properly and commit something. Don't hold your breath, though; I'm very 
>> busy these days.
>>
>> -Corey
> 
> Thanks Corey,
> 
> with the mentioned patch (the link seems to be wrong but I found it 
> anyway) it works fine with the matroska files.

The mailing lists got moved to the new server and old URLs got mixed up.
http://www.mplayerhq.hu/pipermail/mplayer-dev-eng/2006-February/040805.html

> I discovered though that for Quicktime files the patch for demux_mov.c 
> has to be applied as well, otherwise the mapping is incorrect.

Which patch? I don't remember such a patch, though it's possible I wrote
it and forgot about it or somebody else wrote it and I forgot about it.

-Corey