[MPlayer-users] Encoding quality advices

[Martin Collins]

On Thu, 28 Nov 2002 19:24:43 +0100
Moritz Bunkus <moritz at bunkus.org> wrote:

Hi Moritz, looks like some very useful advice. But :-)

>                 $videosize * 8 
> $videobitrate = --------------
>                 $length * 1000

Shouldn't that be 1024 not 1000?

...
> As you can see the resolutions suggested by the script are all
> dividable by 16. This will make the aspect ratio slightly wrong,
> but no one will notice.

AIUI PAL pixels are not square anyway. I find multiplying the pixel
ratio (width/height) by 1.09 gives the right -aspect parameter for
playback. Obviously you would need another modifier for 16:9 stuff.

> Now if you want to decide which resolution (and scaling parameters)
> to chose you can do that by looking at the $bpp:

Why would you scale at all unless you want a VCD or something? Isn't
it better to just crop all the black (maintaining sizes divisible by 16)
and encode that?

By the way, is it possible to save a playback aspect ratio in an ogg in
a way that mplayer will use?

Martin