NV12和NV21转rgb

void NV21_T_RGB(unsigned int width , unsigned int height , unsigned char *yuyv , unsigned char *rgb)
{
const int nv_start = width * height ;
    u32  i, j, index = 0, rgb_index = 0;
    u8 y, u, v;
    int r, g, b, nv_index = 0;
	
 
    for(i = 0; i <  height ; i++)
    {
		for(j = 0; j < width; j ++){
			//nv_index = (rgb_index / 2 - width / 2 * ((i + 1) / 2)) * 2;
			nv_index = i / 2  * width + j - j % 2;

			y = yuyv[rgb_index];
			u = yuyv[nv_start + nv_index ];
			v = yuyv[nv_start + nv_index + 1];
			
		
			r = y + (140 * (v-128))/100;  //r
			g = y - (34 * (u-128))/100 - (71 * (v-128))/100; //g
			b = y + (177 * (u-128))/100; //b
				
			if(r > 255)   r = 255;
			if(g > 255)   g = 255;
			if(b > 255)   b = 255;
       		if(r < 0)     r = 0;
			if(g < 0)     g = 0;
			if(b < 0)     b = 0;
			
			index = rgb_index % width + (height - i - 1) * width;
			rgb[index * 3+0] = b;
			rgb[index * 3+1] = g;
			rgb[index * 3+2] = r;
			rgb_index++;
		}
    }
    return 0;



}