[MPlayer-users] probably my usual stupid question of the week

[justin case]

> Rescaling is the only way that most players understand... If you want
> to keep the original size you'll have to use insanely high bitrate
> anyway.

xvid these days is very capable of keeping the full resolution, if only
the movie is compressible enough.
sadly there is no equivalent to avisynth under linux written yet, so it
is hard to run a compressiblitiy test. surely it could be done somehow,
though.

using autogk
(http://forum.doom9.org/showthread.php?s=&threadid=64266&perpage=40&page
number=1) wich runs a fine compressiblity test before encoding lately i
end up with lots of movies in 720 res., targeting for 1400mb including
ac3 for the first audio track as well as mp3 for a second track. quite
amazing!

what you could do to figure the actual compressiblity of a movie: run a
full first pass using full res and fixed quant 2. that will give you the
movie in maximum quality and you can now check its size.
if it was the size you were targeting for, this would be a 100%
compressibility. if it was half, it would be 50% and so on. as long as
you stay above something like 75%-80%, you could hardly see a difference
to 100%, meaning, you wouldn't have to worry about loosing quality.
so you should adjust your resolution in a way, that your comptest would
reach 75%-80% and have a brilliant result.

if anybody here could bother to have a look at autogk and how it works,
maybe we could develop a script, that does quite the same under linux.

that would be fun and we'd all benefit a lot.

since i use it under windows, my encodes are of a very constant, very
high quality.
also very interessting about this tool is, that if compressibility is
not so great, it makes very clever decisions like useing a softer
rescaler, varies usage of bframes and switches quantization matrixes.

sadly i will just have to stick with windows for encoding as long as
there is nothing similar under linux.

greetings,
/jc