[FFmpeg-devel] BFI video decoder

[Michael Niedermayer]

On Thu, Apr 17, 2008 at 10:05:05PM +0530, Sisir Koppaka wrote:
> On Thu, Apr 17, 2008 at 8:24 PM, Michael Niedermayer <michaelni at gmx.at>
> wrote:
[...]
> >
> >
> > >         char palette[768];
> > >         bfi->frame.pict_type = FF_I_TYPE;
> > >         bfi->frame.key_frame = 1;
> > >         /* Converts the given 6-bit palette values(0-63) to 8-bit
> > values(0-255) */
> > >         for (i = 0; i < avctx->extradata_size; i++)
> > >             palette[i] =
> > >                 (avctx->extradata[i] << 2) | (avctx->extradata[i] >> 4);
> >
> > What could happen if extradata_size where larger than 768 ?
> >
> But we set it to 768 in the demuxer right?

yes, but think about what could happen if someone came up with the idea of
storing bfi in a different container, for example avi. And then that person
would add support for bfi in avi to ffmpeg (this likely just needs a single
line to be added to riff.c). suddenly extradata_size would be read from the
avi file and could be larger than 768.


[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

When the tyrant has disposed of foreign enemies by conquest or treaty, and
there is nothing more to fear from them, then he is always stirring up
some war or other, in order that the people may require a leader. -- Plato
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