Tuukka Toivonen (tuukkat@xxxxxxxxxx):
> On Tue, 5 Aug 2003, Ronald Bultje wrote:
>
> >> Then some cameras supported by qc-usb can deliver MJPEG compressed frames
> >> and I have used
> >> #define VIDEO_PALETTE_MJPEG (('q'<<8) | 2) /* Grab video in compressed MJPEG format */
>
> >It's likely RGB JFIF/JPEG, isn't it? MJPEG is supposed to be YUY2
>
> No. Looks like it's in 4:2:2 packed format (YUY2, I guess). I didn't write
> the decompression code (just ported it to run in kernel, ahem, it's from
> mpeg2dec by Aaron Holtzman), so I'm only 99% sure.
mpeg2dec only has 4:2:0 conversion code, no 4:2:2 code, since MPEG2
only uses 4:2:0. Furthermore, MPEG2 uses 4:2:0 with 601 extents, while
JPEG/JFIF uses the full 0-255 range. It sounds like you might be using
the wrong conversion function.
-Billy
