[MPlayer-users] down-mix to stereo

[Clément Bœsch]

On Fri, Sep 24, 2010 at 06:36:11AM +0000, Zongyao QU wrote:
> 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".
> 

There is a discussion about that in the thread I pasted in previous mail,
especially this post:

http://lists.mplayerhq.hu/pipermail/mplayer-dev-eng/2010-August/065802.html

Also, it's strange you don't have the downmix done in the codecs you
quoted since they are natively implemented.

Last thing; this downmix patch that adds the pan filter is in progress. It
may not take to long to be accepted now (I hope), so you won't have to
worry about that anymore.

> Thank you very much.
> Regards,
> 
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-- 
Clément B.