This YUV 4:1:1 format is registered as a PCI standard format. Mediamatics MPEG 1 engine is the only codec (other than a Brooktree internal one) that I know of that can generate it.
|Y Sample Period||1||1|
|V Sample Period||4||1|
|U Sample Period||4||1|
Effective bits per pixel : 12
Positive biHeight implies top-down image (top line first)