NV21转BGR图像

#undef clamp_g
#define clamp_g(x, minValue, maxValue) ((x) < (minValue) ? (minValue) : ((x) > (maxValue) ? (maxValue) : (x)))

int NV21ToBGR(unsigned char * srcYVU, unsigned char * destBGR, int width, int height)
{

    unsigned char * srcVU = srcYVU + width * height;

    unsigned char Y, U, V;
    int B, G, R;

    for (int i = 0; i < height; i++)
    {
        for (int j = 0; j < width; j++)
        {
            Y = srcYVU[i * width + j];
            V = srcVU[(i / 2 * width / 2 + j / 2) * 2 + 0];
            U = srcVU[(i / 2 * width / 2 + j / 2) * 2 + 1];


            R = 1.164*(Y - 16) + 1.596*(V - 128);
            G = 1.164*(Y - 16) - 0.813*(V - 128) - 0.392*(U - 128);
            B = 1.164*(Y - 16) + 2.017*(U - 128);

            destBGR[(i * width + j) * 3 + 0] = clamp_g(B, 0, 255);
            destBGR[(i * width + j) * 3 + 1] = clamp_g(G, 0, 255);
            destBGR[(i * width + j) * 3 + 2] = clamp_g(R, 0, 255);


        }
    }
    return 0;
}