[FFmpeg-devel] Mutlichannel API for aac.c

Andreas Öman andreas
Sun Nov 9 21:56:10 CET 2008


Michael Niedermayer wrote:
> On Sun, Nov 02, 2008 at 10:25:36PM +0100, Andreas ?man wrote:
>> Hi,
>>
>> aac1.patch is basically some refactoring.
> 
> iam mildly against this, at least without renaming the involved functions
> to repesent the new merged behavior and fully documenting it but with these
> its likely no longer a win in terms of amount of code.
> 
> 
>> aac2.patch does the stuff but depends on mpeg4audio.patch.
> 
> iam against this patch, not only does it replace apparently
> unrelated code by a more complex and more messy implementation, it also
> does not seem to implement channel layouts correctly. Rather it just hardcodes
> them for defaults while ignoring non defaults.

Well, the default set is pretty hardcoded, I can't say I follow you
there. Perhaps you are referring to the fact that the channel output
order would be same even if we change the CH_ -defines in avcodec.h ?

Also, the non-defaults are just a set of stereo, mono and LFE-channels.
I have not found any info in the specs how to map these to speaker
positions.
Of course, one could assume that for a equal setup as in a default
setting, the speaker mappings would be the same.
I'll see if I can come up with something.





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