[MPlayer-dev-eng] [PATCH] liba52 problems with 2-ch vob, 6-ch output

[eric at lammerts.org]

On Thu, Dec 27, 2001 at 04:40:16AM +0200, Arpi wrote:
> > 
> > Liba52 does not "upmix" the output to 5+1 channels, so this causes a lot of
> > garbage in the sound output (this is described in liba52.txt).
> 
> i think this should be fixed in liba52's downsample.c, or at worst case, at
> resample.c. (there are upsampling code too at downsample.c)

It's documented behavior of liba52 (but not very convenient)

> i think, if user wants 6 channels, he should get it.
> especially for dolby, we should upmix dolby encoded channels to 6
> independent channels (dolby decoder).
> 
> afaik there was such code in libac3, and shoudl be in liba52 too.

Agreed.
But if you play a non-ac3 movie with just 2 channels, mplayer won't
give you 6-channel output either.

> > Index: dec_audio.c
> about the patch. it's messy, the channel setup code shoudl go into new
> function, or directly at liba52 init part, instead of placing it in decoder
> loop with option to enable it only at init part.

Agreed. But I wanted to avoid any structural changes in the code.

I think the whole dec_audio.c is messy. It would be better to put the
code for every decoder in a separate file and use function pointers
instead of these giant switch() statements.

Eric