Too long to put in a comment...
4:2:2 is not a pixel-format, it is just a notation about how the chroma-data have been subsampled. According to the linuxtv-link, V4L2_PIX_FMT_YUYV is identical to YUYV or YUY2. The ultimate reference on the subject is http://www.fourcc.org. Have a look at what it says about YUY2 at http://www.fourcc.org/yuv.php#YUYV
Horizontal Vertical
Y Sample Period 1 1
V Sample Period 2 1
U Sample Period 2 1
To verify that that the input format indeed is YUYV you can use a viewer I wrote using SDL; which natively supports this format (among others)
https://github.com/figgis/yuv-viewer
See also http://www.fourcc.org/fccyvrgb.php for correct formulas for rgb/yuv-conversion.
Take it from there and drop me a comment if you need further assistance...