Re: Conversion of YCbCr (4:2:2) to jpeg

Try JpegLib by the Independent JPEG Group. Chances are
the Lib accepts the YUV format.

It actually works after minor adaptation to Windows CE, and takes as input
"video lines" in the YUV format.
I agree with you for the potential loss of quality caused by the "YUV 4:2:2
to RGB back to YUV" conversion, although it can theoretically be harmless: I
am not a mathematician but the formulaes used to convert to and from the two
formats look rather reversible. The main picture degradation (half the
colors going to nirvana) comes from the initial "samples to 4:2:2"
conversion. IMO, the effects of extra conversions should be the loss of a
few other colors close to the white and black areas.
Thus, if quality is not an issue, maybe is it simpler for the OP to make the
first conversion and to let MS code perform the second one.
Also consider that if some on-screen display of the captured data is also
needed, maybe RGB format will be needed too, e.g. if a DirectDraw-compliant
video driver is not available.

Remi


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