[FFmpeg-devel] [PATCH]v308 and yuv4 encoders and decoders

[Carl Eugen Hoyos]

Derek Buitenhuis <derek.buitenhuis <at> gmail.com> writes:

> >> This should be added as:
> >>
> >> CODEC_ID_V308,
> >> CODEC_ID_YUV4,
> >>
> >> directly above:
> >>
> >> CODEC_ID_UTVIDEO = 0x800,
> > I may be completely misunderstanding this, but I believe this is impossible.
> 
> It's entirely possible. In fact, I was specifically told to do this
> when i submitted my VBLE and v410 files. :)

[...]

> >>> +            u[j] = *src++ ^ 0x80;
> >>> +            v[j] = *src++ ^ 0x80;
> >> Where does the xor with 0x80 come from?
> > Copied from raw_decode() in libavcodec/rawdec.c
> >
> >> Something to do with signed-ness?
> > No idea.
> 
> The 0x80 in rawdec.c is to do with signed chroma. I don't see any
> evidence anywhere that yuv4 has anything but unsigned chroma values...

> I'm not sure it's needed.

I am not sure now:
Could you confirm that you are being serious (I like practical jokes, but I
admit I sometimes do not understand them)?

Carl Eugen