I am having trouble displaying a raw YUV file that it is in NV12 format.
I can display a selected frame, however, it is still mainly in black and white with certain shade
The picture looks like you have 4:1:1 format. You should change your lines to
float U = lookupTableU [uvBuffer [ (y * (YUV_WIDTH / 4) + (x/4)) * 2 ] ]
float V = lookupTableU [uvBuffer [ (y * (YUV_WIDTH / 4) + (x/4)) * 2 + 1] ]
Maybe you can post the result to see, what else is wrong. I find it always hard to think about it. It's much easier to approach this iteratively.