[XviD-devel] [BUG] BFrame encoder doesn't force intra for 1st frame

[Dirk Knop]

Hi,

Michael Militzer wrote:

>As a side note: At least on windows our decoder has problems with our divx50
>compat. b-frame clips: The first frame (i-frame) is correctly displayed and
>then no frame at all is presented anymore until the next keyframe comes in.
>Starting from the seconf keyframe everything is fine. Maybe the decoder has
>problems with the SKIP frame at the beginning?
>
> At least DivX 5.02 and ffdshow (which uses libavcodec from ffmpeg) decode
> our clips (from the very beginning). However, DivX5 displays some wrong
> blocks (they are at the right position but simply somehow corrupted) and
> ffdshow has also problems. Interestingly the blocks that DivX5 decodes
> incorrectly are correctly represented by ffdshow, but ffmpeg decodes a lot
> of "jumping" blocks (looks like wrong MVs). Our decoder displays everything
> just fine (well, after the second keyframe has been reached ;-)) - I just


I get those results when using either divx5 bvop compatibility or plain 
"xvid style". I'm glad that someone finally confirmed that problem.
For me, the xvid decoder crashes on bframes (even if I #define 
#BFRAME_DEC), either the VFW in vdub and the DShow in WMP.
Interesting is that gruel could see that the files produced in windows 
encoder are wrong (shows the same there), but if encoding in linux 
everything is fine.
I didn't find the problem in VFW, but I just tried to read that code 
some times without succeeding in understanding every detail.

I hope this helps,

regards,
Dirk