Are you working with interleaved or planar YUV, and is it really YUV or YCbCr? For interleaved YCbCr I use ippiCbYCr422ToBGR_8u_C2C4R(), but it generates a 32 bit RGB (there is no interleaved YCbCr 422 to RGB24 that I know of). If you really need 24 bit RGB out, then you will need to convert it to some other format first.
For example, you could convert the YCbCr to CbYCr and then call ippiCbYCr422ToRGB_8u_C2C3R() to get your 24 bit RGB out.
Peter
