Display YUV in OpenGL

Question

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

Answer 1

I think you're addressing U and V values incorrectly. Rather than:

float U = lookupTableU [uvBuffer [ ((y / 2) * (x / 2) + (x/2)) * 2  ] ]; 
float V = lookupTableV [uvBuffer [  ((y / 2) * (x / 2) + (x/2)) * 2 + 1] ];

It should be something along the lines of

float U = lookupTableU [uvBuffer [ ((y / 2) * (YUV_WIDTH / 2) + (x/2)) * 2  ] ]; 
float V = lookupTableV [uvBuffer [  ((y / 2) * (YUV_WIDTH / 2) + (x/2)) * 2 + 1] ];

Answer 2

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.

Answer 3

Next try :) I think you're uv buffer is not interleaved. It looks like the U values come first and then the array of V values. Changing the lines to

unsigned int voffset = YUV_HEIGHT * YUV_WIDTH / 2;
float U = lookupTableU [uvBuffer [ y * (YUV_WIDTH / 2) + x/2] ]; 
float V = lookupTableV [uvBuffer [ voffset + y * (YUV_WIDTH / 2) + x/2] ];

might indicate if this is really the case.