YUV422 uses 4 bytes per 2 pixels
In YUV422 mode the U
ans V
values are shared between two pixels. The bytes in the Image are ordered like U0 Y0 V0 Y1 U2 Y2 V2 Y3
etc.
Giving pixels like:
pixel 0 U0Y0V0
pixel 1 U0Y1V0
pixel 2 U2Y2V2
pixel 3 U2Y3V2