[MPlayer-users] down-mix to stereo

[Zongyao QU]

Clément Bœsch <ubitux <at> gmail.com> writes:

> I may not use the correct vocabulary, but as I understand it, some codecs
> "natively" implements the downmix, but not all of them. So my patch
> manually adds a downmix audio filter for those who don't have it (for
> example Flac).

Thank you for the reply.
I may not make myself clear. Sorry for my lame English.

I am not worried about the down-mix feature inside the decoder, since I
won't use them at all.
I will use the pan filter to mix the channels to stereo myself.

But the definition of the channel map are different in different standard.

5.1 WAV  FL , FR , FC , LFE, SL , SR 
5.1 AC3  FL , FC , FR , SL , SR , LFE 
5.1 DTS  FC , FL , FR , SL , SR , LFE 
5.1 AAC  FC , FL , FR , SL , SR , LFE 
5.1 AIFF FL , SL , FC , FR , SR , LFE
5.1 FLAC FL , FR , FC , LFE, SL , SR

I am curious that whether mplayer will first re-map the all of
those channels to one unified layout, then pass it to the filter chain?
or it will hold the original layout?

if the answer is "re-map", 
then where to find the "unified layout".

Thank you very much.
Regards,