[MPlayer-users] AAC 5.1 and -af pan= (5.1ch->2ch)

[LLoyd Bates]

Am Freitag, den 18.02.2005, 01:19 -0800 schrieb Loren Merritt:
> On Fri, 18 Feb 2005, LLoyd Bates wrote:
> 
> > Hi there,
> > This message goes out to the people that use the pan filter and know
> > exactly what they are doing.
> >
> > Up to now i wasn't able to fully enjoy a video encoded with 5.1 aac
> > since mplayer did not downmix to Stereo. After some time i found the pan
> > filter and played with it some time.
> > This is what i found working: '-af
> > pan=6:1:0:1:0:0:1:1:0:0.5:0.5:0.5:0.5'
> >
> > BUT, since i don't know exactly how to handle the pan filter the
> > resulting Stereo output is less than optimal. Anyone out there that can
> > give a better line for
> > 5.1ch -> 2ch Stereo downmixing?
> >
> > (iirc this is only needed with aac 5.1. if the audio is ac3 or ogg
> > vorbis mplayer will downmix automatically)
> > and sorry for the bad english.
> 
> I use -af pan=6:.32:.39:.06:.17:-.17:.33:.32:.06:.39:-.17:.17:.33
> I got the coefficients from MatrixMixer. I can't vouch for any theoretical 
> basis, but they sound fine to me.
> (You can see that my matrix is not normalized; I had to scale down the 
> coefficients to avoid clipping.)
> 
> --Loren Merritt
> 
Well, if i use '-af
pan=6:.32:.39:.06:.17:-.17:.33:.32:.06:.39:-.17:.17:.33' i get no sound
at all .. it's just silent.
(mplayer-1.0pre6a)