[MPlayer-dev-eng] XviD codec

[Arpi]

Hi,

I've just tested the latest XviD cvs snapshot. It changed a lot in last
month, at least they dropped the encore2/decore structure and now has a
single library containing both coder and decoder with xvid api.
there is also a wrapper for divx4's encore/decore api.

after editing config.mak (remove -ldivxencore and -ldivxdecore, and insert
/path/to/xvid/build/libcore.a) i got it compile.

playing back divx4-encoded avi with xvid: no image, and 'no
vop_start_code' messages.

encoding with xvid: seems to be ok, quality is worse than divx4 at first
look (Gabucino: here is the next job for you :)) and i'm not so amazed from
speed, it's even slower a bit. yes, i should compile xvid with optimzations
enabled, current makefile compiles with no more than -g

decoding: it cannot play its own file, gives sig11. but i could playback
xvid avi with ffmpeg's mpeg4 codec :)  libavcodec rulez.

so, if we could get it working (no sig11 and some more odivx/divx4 compatibility)
then we could replace old opendivx code with xvid, and provide opensource
divx encoding for non-linux platforms.

to tell some positive thing: they used nasm for asm stuff, so it's portable
between x86 platforms without modifications to asm code.
(old opendivx had different version for gnu and intel asm)
anyway, at first look, i miss more optimization, and 3dnow/sse stuff. there
are just some minor functions (mainly byte/word converter memcpy, colorspace
converters (unused by mplayer) and idct).

but don't forget: it's 100% opensource, and is close to gpl (if i understood
well their page), so we could help them to get best performance.
(especially to the encoder, we have already good fast best decoder in
libavcodec)

xvid doesn't include postprocessing filter, but it isn't problem for us, we
have a better one :)


A'rpi / Astral & ESP-team

--
mailto:arpi at thot.banki.hu
http://esp-team.scene.hu