YUYV格式到RGB格式的转换

Posted 2020-09-08 0 1 0 1

为什么YUYV格式要转到RGB格式，视频的显示调用的多数API都是基于RGB格式，所以需要进行格式的转换。

YUYV格式如下：
Y0U0Y1V0 Y2U1Y3V1..........
说明：一个Y代表一个像素，而一个Y和UV组合起来构成一个像素，所以第0个像素Y0和第一个像素Y1都是共用第0个像素的U0和V0。而每个分量Y，U，V都是占用一个字节的存储空间。所以Y0U0Y1V0相当于两个像素，占用了4个字节的存储空间，平均一个像素占用两个字节。

RGB格式：
R0G0B0 R1G1B1.........
说明：一个像素由三个分量构成，即一个像素占用三个字节。

YUV到RGB的转换有如下公式：
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));

 1 int yuvtorgb0(unsigned char *yuv, unsigned char *rgb, unsigned int width, unsigned int height)
 2 {
 3     unsigned int in, out;
 4     int y0, u, y1, v;
 5     unsigned int pixel24;
 6     unsigned char *pixel = (unsigned char *)&pixel24;
 7     unsigned int size = width*height*2;
 8 
 9     for (in = 0, out = 0; in < size; in += 4, out += 6)
10     {
11         y0 = yuv[in+0];
12         u  = yuv[in+1];
13         y1 = yuv[in+2];
14         v  = yuv[in+3];
15 
16         sign3 = true;
17         pixel24 = yuvtorgb(y0, u, v);
18         rgb[out+0] = pixel[0];    //for QT
19         rgb[out+1] = pixel[1];
20         rgb[out+2] = pixel[2];
21         //rgb[out+0] = pixel[2];  //for iplimage
22         //rgb[out+1] = pixel[1];
23         //rgb[out+2] = pixel[0];
24     
25         //sign3 = true;
26         pixel24 = yuvtorgb(y1, u, v);
27         rgb[out+3] = pixel[0];
28         rgb[out+4] = pixel[1];
29         rgb[out+5] = pixel[2];
30         //rgb[out+3] = pixel[2];
31         //rgb[out+4] = pixel[1];
32         //rgb[out+5] = pixel[0];
33     }
34     return 0;
35 }
36 
37 int yuvtorgb(int y, int u, int v)
38 {
39     unsigned int pixel24 = 0;
40     unsigned char *pixel = (unsigned char *)&pixel24;
41     int r, g, b;
42     static long int ruv, guv, buv;
43 
44     if (sign3)
45     {
46         sign3 = false;
47         ruv = 1159*(v-128);
48         guv = 380*(u-128) + 813*(v-128);
49         buv = 2018*(u-128);
50     }
51 
52     r = (1164*(y-16) + ruv) / 1000;
53     g = (1164*(y-16) - guv) / 1000;
54     b = (1164*(y-16) + buv) / 1000;
55 
56     if (r > 255) r = 255;
57     if (g > 255) g = 255;
58     if (b > 255) b = 255;
59     if (r < 0) r = 0;
60     if (g < 0) g = 0;
61     if (b < 0) b = 0;
62 
63     pixel[0] = r;
64     pixel[1] = g;
65     pixel[2] = b;
66 
67     return pixel24;
68 }

 http://blog.chinaunix.net/uid-21410064-id-3248638.html