Re[2]: [XviD-devel] xvid + bframes and mplayer/ffmpeg decoding

[Michael Niedermayer]

Hi

On Friday 16 August 2002 14:50, Christoph Lampert wrote:
> On Fri, 16 Aug 2002, Radoslaw Czyz wrote:
> > > Ouch! Is this in the standard? Where? Is this for B-frames, too?
note 2 in 7.4.4.5

[...]
> Just as I said: It doesn't check i(!)DCT. It does DCT and Quant and
> decides on that if the block should be coded.
same for ffmpeg, so we should have that problem too :(

[...]

>
> In theory, this cannot happen with iDCT, but with rounding, going
> e.g. from sum=1 to 0 is possible.
>
> Xvid does not check for such blocks (which results in only zeroes for
> motion compensation, so _if_ they appear, they might again and again and
> again).
yes, and its allso a beatifull way to increase the filesize ...

[...]

Michael