[Ffmpeg-devel] H.264 decoding bug in either lavc/JM (x264 too?)

Michael Niedermayer michaelni
Wed Jul 27 02:16:33 CEST 2005


Hi

On Monday 25 July 2005 18:25, Loren Merritt wrote:
> On Fri, 22 Jul 2005, Tuukka Toivonen wrote:
> > I encoded a video clip using x264 and decoded with both
> > Mplayer (lavc) and JM 9.6. The two decoded videos differ
> > slightly on some frames. I think this is bug, as
> > H.264 should be bit exact, shouldn't it?
> >
> > Here's frame-by-frame comparison:
>
> [...]
>
> > x264 command line:
> > --bframes 2 --8x8dct --b-pyramid --qp 26 --direct spatial
> > The problem occurs only if using all three options --8x8dct, --b-pyramid,
> > and --direct spatial. Most other options seem not to matter.
>
> Possible cause:
> h264.c:1207 should fall back to h->ref_list[1][0].motion_val[1][b4_xy] if
> h->ref_list[1][0] is a B-frame and the colocated block is L1 predicted.

fixed

[...]
-- 
Michael





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