YUYV格式到RGB格式的轉換：
爲什麼YUYV格式要轉到RGB格式，視頻的顯示調用的多數API都是基於RGB格式，所以需要進行格式的轉換。
YUYV格式如下：
Y0U0Y1V0 Y2U1Y3V1..........
說 明：一個Y代表一個像素，而一個Y和UV組合起來構成一個像素，所以第0個像素Y0和第一個像素Y1都是共用第0個像素的U0和V0。而每個分量 Y，U，V都是佔用一個字節的存儲空間。所以Y0U0Y1V0相當於兩個像素，佔用了4個字節的存儲空間，平均一個像素佔用兩個字節。
RGB格式：
R0G0B0 R1G1B1.........
說明：一個像素由三個分量構成，即一個像素佔用三個字節。
YUV到RGB的轉換有如下公式：
R = 1.164*(Y-16) + 1.159*(V-128);
G = 1.164*(Y-16) - 0.380*(U-128)+ 0.813*(V-128);
B = 1.164*(Y-16) + 2.018*(U-128));
int yuvtorgb0(unsigned char *yuv, unsigned char *rgb, unsigned int
width, unsigned int height)
{
unsigned int in, out;
int y0, u, y1, v;
unsigned int pixel24;
unsigned char *pixel = (unsigned char *)&pixel24;
unsigned int size = width*height*2;/*yuyv中一個像素佔據兩個字節*/
for(in = 0, out = 0; in < size; in += 4, out += 6)
{
y0 = yuv[in+0];/*分離出Y U V*/
u = yuv[in+1];
y1 = yuv[in+2];
v = yuv[in+3];
sign3 = true;
pixel24 = yuvtorgb(y0, u, v);/*轉化第0個像素*/
rgb[out+0] = pixel[0]; //for QT
rgb[out+1] = pixel[1];
rgb[out+2] = pixel[2];
//rgb[out+0] = pixel[2]; //for iplimage
//rgb[out+1] = pixel[1];
//rgb[out+2] = pixel[0];
//sign3 = true;
pixel24 = yuvtorgb(y1, u, v);/*轉化第1個像素*/
rgb[out+3] = pixel[0];
rgb[out+4] = pixel[1];
rgb[out+5] = pixel[2];
//rgb[out+3] = pixel[2];
//rgb[out+4] = pixel[1];
//rgb[out+5] = pixel[0];
}
return 0;
}
int yuvtorgb(int y, int u, int v)
{
unsigned int pixel24 = 0;
unsigned char *pixel = (unsigned char *)&pixel24;
int r, g, b;
static long int ruv, guv, buv;
if(sign3)
{
sign3 = false;
ruv = 1159*(v-128);
guv = 380*(u-128) + 813*(v-128);
buv = 2018*(u-128);
}
r = (1164*(y-16) + ruv) / 1000;
g = (1164*(y-16) - guv) / 1000;
b = (1164*(y-16) + buv) / 1000;
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;
pixel[0] = r;
pixel[1] = g;
pixel[2] = b;
return pixel24;
}