YUV420、YUV422、RGB24转换

//平面YUV422转平面RGB24
static void YUV422p_to_RGB24(unsigned char *yuv422[3], unsigned char *rgb24, int width, int height)
{
int R,G,B,Y,U,V;
int x,y;
int nWidth = width>>1; //色度信号宽度
for (y=0;y<height;y++)
{
for (x=0;x<width;x++)
{
Y = *(yuv422[0] + y*width + x);
U = *(yuv422[1] + y*nWidth + (x>>1));
V = *(yuv422[2] + y*nWidth + (x>>1));
R = Y + 1.402*(V-128);
G = Y – 0.34414*(U-128) – 0.71414*(V-128);
B = Y + 1.772*(U-128);

//防止越界
if (R>255)R=255;
if (R<0)R=0;
if (G>255)G=255;
if (G<0)G=0;
if (B>255)B=255;
if (B<0)B=0;

*(rgb24 + ((height-y-1)*width + x)*3) = B;
*(rgb24 + ((height-y-1)*width + x)*3 + 1) = G;
*(rgb24 + ((height-y-1)*width + x)*3 + 2) = R; 
}
}
}

//平面YUV420转平面YUV422
static void YUV420p_to_YUV422p(unsigned char *yuv420[3], unsigned char *yuv422, int width, int height)
{
int x, y;
//亮度信号Y复制
int Ylen = width*height;
memcpy(yuv422, yuv420[0], Ylen);
//色度信号U复制
unsigned char *pU422 = yuv422 + Ylen; //指向U的位置
int Uwidth = width>>1; //422色度信号U宽度
int Uheight = height>>1; //422色度信号U高度 
for (y = 0; y < Uheight; y++) 
{ 
memcpy(pU422 + y*width, yuv420[1] + y*Uwidth, Uwidth);
memcpy(pU422 + y*width + Uwidth, yuv420[1] + y*Uwidth, Uwidth);
}
//色度信号V复制
unsigned char *pV422 = yuv422 + Ylen + (Ylen>>1); //指向V的位置
int Vwidth = Uwidth; //422色度信号V宽度
int Vheight = Uheight; //422色度信号U宽度
for (y = 0; y < Vheight; y++) 
{ 
memcpy(pV422 + y*width, yuv420[2] + y*Vwidth, Vwidth);
memcpy(pV422 + y*width + Vwidth, yuv420[2] + y*Vwidth, Vwidth);
} 
}

//平面YUV420转RGB24
static void YUV420p_to_RGB24(unsigned char *yuv420[3], unsigned char *rgb24, int width, int height)
{
// int begin = GetTickCount();
int R,G,B,Y,U,V;
int x,y;
int nWidth = width>>1; //色度信号宽度
for (y=0;y<height;y++)
{
for (x=0;x<width;x++)
{
Y = *(yuv420[0] + y*width + x);
U = *(yuv420[1] + ((y>>1)*nWidth) + (x>>1));
V = *(yuv420[2] + ((y>>1)*nWidth) + (x>>1));
R = Y + 1.402*(V-128);
G = Y – 0.34414*(U-128) – 0.71414*(V-128);
B = Y + 1.772*(U-128);

//防止越界
if (R>255)R=255;
if (R<0)R=0;
if (G>255)G=255;
if (G<0)G=0;
if (B>255)B=255;
if (B<0)B=0;

*(rgb24 + ((height-y-1)*width + x)*3) = B;
*(rgb24 + ((height-y-1)*width + x)*3 + 1) = G;
*(rgb24 + ((height-y-1)*width + x)*3 + 2) = R;
// *(rgb24 + (y*width + x)*3) = B;
// *(rgb24 + (y*width + x)*3 + 1) = G;
// *(rgb24 + (y*width + x)*3 + 2) = R; 
}
}
}