YUV420 to YUV422转换

/* convert 4:2:0 to yuv 4:2:2 */ 
void yuv420p_to_yuv422(uint8_t * yuv420[3], uint8_t * dest, int width, 
                        int height) 
{ 
    unsigned int x, y; 
 
 
     for (y = 0; y < height; ++y) { 
       uint8_t *Y = yuv420[0] + y * width; 
        uint8_t *Cb = yuv420[1] + (y / 2) * (width / 2); 
       uint8_t *Cr = yuv420[2] + (y / 2) * (width / 2); 
        for (x = 0; x < width; x += 2) { 
             *(dest + 0) = Y[0]; 
           *(dest + 1) = Cb[0]; 
           *(dest + 2) = Y[1]; 
            *(dest + 3) = Cr[0]; 
             dest += 4; 
             Y += 2; 
             ++Cb; 
             ++Cr; 
         } 
     } 
}