[XviD-devel] Invalid stuffing bits and divx 5.0.3 qpel

[Michael Niedermayer]

Hi

On Thursday 20 March 2003 05:02, Bobololo wrote:
> On Wed, 19 Mar 2003, Michael Niedermayer wrote:
> > > > > ffdshow/ffmpeg/mplayer should decode it correctly, if not then
> > > > > upload a sample file to ftp://mplayerhq.hu & tell me that u did
> > > >
> > > > btw, IIRC its some chroma MV rounding bug in divx 503 which causes
> > > > this
> > >
> > > Do you have a sample? As far as I heard, DivXnetworks believes QPel
> > > chroma
> >
> > perhaps, but i cant find it, i guess any video with slow moving stuff
> > should do
>
> I've done a few more tests and you may be interested by the results. I've
> uploaded coastguard_cif-q3-qpel.m4v to ftp://mplayerhq.hu/MPlayer/incoming
>
> This file is an elementary stream generated (m4v) using DivX 503 Pro. The
> encoding settings are :
>
> - rc = constant quantiser set to 3
> - slowest motion estimation
> - max keyframe interval = 300
> - use quarter pel
>
> I decoded this stream with XviD using xvid_decraw. Except the fact
> that only 285 frames are decoded due to the very basic input buffer
> management, the result is near from DivX decoding. I think there is a
> problem with the chroma that we can see from frame 28 (red color shift
> on the upper boat).
>
> ffmpeg completely failed to decode this stream. I guess it's probably an
hmm "ffmpeg -i coastguard_cif-q3-qpel.m4v test.avi" works fine here, no error 
messages, and u can also use mplayer too, but u need to pass some -fps <some 
number> for mpeg4-es streams ...

both ffmpeg & mplayer (with libavcodec) decode it correctly

[...]

Michael