[XviD-devel] xvid decoder and "mpeg-4 not in avi" problems (pts, vol)

[bond]

now that mpeg-4 part2 gets more and more not stored in .avi (but for example
in mp4 or "natively" in mkv) there seem to be problems showing up with the
xvid dshow decoder whit streams that dont show the typical mpe4-in-avi
characterstics, like the vol on the i-frames...

haali's dshow media parser (handles mp4 and native mkv) showed that a parser
to be able to correctly work with xvid (or divx5) has to apply lots of
workarounds and make a mpeg-4 stream appear to come from avi (eg vol on
i-vops).
he also meant that it should be very easy to fix the xvid decoder "with a
few lines of code" to handle also mpeg-4 coming not from avi

this for example will it also make possible to decode real variable
framerate streams with xvid

the following issues seem to exist in the xvid dshow decoder currently:
1) xvid don't work at all when fed with real PTS time values as dshow specs
require, it expects b0rked avi timestamps when using avi-compatible mp4v
"fourcc"
2) xvid doesnt like when the sequence header is only in the mediatype/format
block and not in the frames themselves

you can find haali's parser here:
http://haali.cs.msu.ru/mkv/

if someone wants a .mp4 sample for testing, just give me a shout :)

cheers
bond