[XviD-devel] xvid + bframes and mplayer/ffmpeg decoding

[Christoph Lampert]

On Fri, 16 Aug 2002, Michael Niedermayer wrote:
> btw, it seems that the walken IDCT output all zeros on some non zero inputs 
> from green_bug avi, and iirc the mpeg4 std says the encoder shouldnt encode 
> blocks with non zero coeffs which are all zero through its own IDCT, perhaps 
> that is the cause of the green bug

Ouch! Is this in the standard? Where? Is this for B-frames, too? 

Because XviD does not check iDCT results to decide if a block should be
encoded. For B-frames, iDCT isn't even _done_!

gruel

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