[MPlayer-users] too small sound with multichannel media file

[Clément Bœsch]

On Sat, Feb 12, 2011 at 04:18:39PM +0100, Simon Chen wrote:
> On Sat, Feb 12, 2011 at 11:55 AM, Clément Bœsch <ubitux at gmail.com> wrote:
> 
> > Automatic downmix has been introduced in 32356, you should upgrade your
> > MPlayer.
> >
> > And how to do it manually?

I guess the "how to do it manually" is part of your question. Basically,
you can simply use the pan filter. This is the part that may interest you
in the patch:

    static const char * const downmix_strs[AF_NCH + 1] = {
        /*                FL       FR       RL       RR          FC          LF         AL      AR */
        [3] = "pan=2:" "0.6:0:" "0:0.6:"                     "0.4:0.4",
        [4] = "pan=2:" "0.6:0:" "0:0.6:" "0.4:0:"  "0:0.4",
        [5] = "pan=2:" "0.5:0:" "0:0.5:" "0.2:0:"  "0:0.2:"  "0.3:0.3",
        [6] = "pan=2:" "0.4:0:" "0:0.4:" "0.2:0:"  "0:0.2:"  "0.3:0.3:"   "0.1:0.1",
        [7] = "pan=2:" "0.4:0:" "0:0.4:" "0.2:0:"  "0:0.2:"  "0.3:0.3:"              "0.1:0:" "0:0.1",
        [8] = "pan=2:" "0.4:0:" "0:0.4:" "0.15:0:" "0:0.15:" "0.25:0.25:" "0.1:0.1:" "0.1:0:" "0:0.1",
    };

If you have a 5.1, just use -af pan=2:0.4:0:0:0.4:0.2:0:0:0.2:0.3:0.3:0.1:0.1

> For the record I do have other 6 channels mkv files. And they're played
> pretty good aka down to 2 channels.

Maybe because it's "fake" 5.1, or simply channels are not well used.

Btw, why do you refuse to update?

-- 
Clément B.