RGB24与YUV420之间的互相转换

 //
 //              rgb转yuv420
 //
 bool  RGB2YUV(LPBYTE RgbBuf,UINT nWidth,UINT nHeight,LPBYTE yuvBuf,unsigned long *len)
 {
     int i, j;
     unsigned char*bufY, *bufU, *bufV, *bufRGB,*bufYuv;
     memset(yuvBuf,0,(unsigned int )*len);
     bufY = yuvBuf;
     bufV = yuvBuf + nWidth * nHeight;
     bufU = bufV + (nWidth * nHeight* 1/4);
     *len = 0;
     unsigned char y, u, v, r, g, b,testu,testv;
     unsigned int ylen = nWidth * nHeight;
     unsigned int ulen = (nWidth * nHeight)/4;
     unsigned int vlen = (nWidth * nHeight)/4;
     for (j = 0; j
     {
         bufRGB = RgbBuf + nWidth * (nHeight - 1 - j) * 3 ;
         for (i = 0;i
         {
             int pos = nWidth * i + j;
             r = *(bufRGB++);
             g = *(bufRGB++);
             b = *(bufRGB++);
             y = (unsigned char)( ( 66 * r + 129 * g +  25 * b + 128) >> 8) + 16  ;
             u = (unsigned char)( ( -38 * r -  74 * g + 112 * b + 128) >> 8) + 128 ;
             v = (unsigned char)( ( 112 * r -  94 * g -  18 * b + 128) >> 8) + 128 ;
             *(bufY++) = max( 0, min(y, 255 ));
             if (j%2==0&&i%2 ==0)
             {
                 if (u>255)
                 {
                     u=255;
                 }
                 if (u<0)
                 {
                     u = 0;
                 }
                 *(bufU++) =u;
                 //存u分量
             }
             else
             {
                 //存v分量
                 if (i%2==0)
                 {
                     if (v>255)
                     {
                         v = 255;
                     }
                     if (v<0)
                     {
                         v = 0;
                     }
                     *(bufV++) =v;
                 }
             }
         }
     }
     *len = nWidth * nHeight+(nWidth * nHeight)/2;
     return true;
 }
 //
 //              yuv420转rgb
 //
 bool YUV2RGB(LPBYTE yuvBuf,UINT nWidth,UINT nHeight,LPBYTE pRgbBuf,unsigned long *len)
 {
 #define PIXELSIZE nWidth * nHeight
     const int Table_fv1[256]={ -180, -179, -177, -176, -174, -173, -172, -170, -169, -167, -166, -165, -163, -162, -160, -159, -158, -156, -155, -153, -152, -151, -149, -148, -146, -145, -144, -142, -141, -139, -138, -137, -135, -134, -132, -131, -130, -128, -127, -125, -124, -123, -121, -120, -118, -117, -115, -114, -113, -111, -110, -108, -107, -106, -104, -103, -101, -100, -99, -97, -96, -94, -93, -92, -90, -89, -87, -86, -85, -83, -82, -80, -79, -78, -76, -75, -73, -72, -71, -69, -68, -66, -65, -64, -62, -61, -59, -58, -57, -55, -54, -52, -51, -50, -48, -47, -45, -44, -43, -41, -40, -38, -37, -36, -34, -33, -31, -30, -29, -27, -26, -24, -23, -22, -20, -19, -17, -16, -15, -13, -12, -10, -9, -8, -6, -5, -3, -2, 0, 1, 2, 4, 5, 7, 8, 9, 11, 12, 14, 15, 16, 18, 19, 21, 22, 23, 25, 26, 28, 29, 30, 32, 33, 35, 36, 37, 39, 40, 42, 43, 44, 46, 47, 49, 50, 51, 53, 54, 56, 57, 58, 60, 61, 63, 64, 65, 67, 68, 70, 71, 72, 74, 75, 77, 78, 79, 81, 82, 84, 85, 86, 88, 89, 91, 92, 93, 95, 96, 98, 99, 100, 102, 103, 105, 106, 107, 109, 110, 112, 113, 114, 116, 117, 119, 120, 122, 123, 124, 126, 127, 129, 130, 131, 133, 134, 136, 137, 138, 140, 141, 143, 144, 145, 147, 148, 150, 151, 152, 154, 155, 157, 158, 159, 161, 162, 164, 165, 166, 168, 169, 171, 172, 173, 175, 176, 178 };
     const int Table_fv2[256]={ -92, -91, -91, -90, -89, -88, -88, -87, -86, -86, -85, -84, -83, -83, -82, -81, -81, -80, -79, -78, -78, -77, -76, -76, -75, -74, -73, -73, -72, -71, -71, -70, -69, -68, -68, -67, -66, -66, -65, -64, -63, -63, -62, -61, -61, -60, -59, -58, -58, -57, -56, -56, -55, -54, -53, -53, -52, -51, -51, -50, -49, -48, -48, -47, -46, -46, -45, -44, -43, -43, -42, -41, -41, -40, -39, -38, -38, -37, -36, -36, -35, -34, -33, -33, -32, -31, -31, -30, -29, -28, -28, -27, -26, -26, -25, -24, -23, -23, -22, -21, -21, -20, -19, -18, -18, -17, -16, -16, -15, -14, -13, -13, -12, -11, -11, -10, -9, -8, -8, -7, -6, -6, -5, -4, -3, -3, -2, -1, 0, 0, 1, 2, 2, 3, 4, 5, 5, 6, 7, 7, 8, 9, 10, 10, 11, 12, 12, 13, 14, 15, 15, 16, 17, 17, 18, 19, 20, 20, 21, 22, 22, 23, 24, 25, 25, 26, 27, 27, 28, 29, 30, 30, 31, 32, 32, 33, 34, 35, 35, 36, 37, 37, 38, 39, 40, 40, 41, 42, 42, 43, 44, 45, 45, 46, 47, 47, 48, 49, 50, 50, 51, 52, 52, 53, 54, 55, 55, 56, 57, 57, 58, 59, 60, 60, 61, 62, 62, 63, 64, 65, 65, 66, 67, 67, 68, 69, 70, 70, 71, 72, 72, 73, 74, 75, 75, 76, 77, 77, 78, 79, 80, 80, 81, 82, 82, 83, 84, 85, 85, 86, 87, 87, 88, 89, 90, 90 };
     const int Table_fu1[256]={ -44, -44, -44, -43, -43, -43, -42, -42, -42, -41, -41, -41, -40, -40, -40, -39, -39, -39, -38, -38, -38, -37, -37, -37, -36, -36, -36, -35, -35, -35, -34, -34, -33, -33, -33, -32, -32, -32, -31, -31, -31, -30, -30, -30, -29, -29, -29, -28, -28, -28, -27, -27, -27, -26, -26, -26, -25, -25, -25, -24, -24, -24, -23, -23, -22, -22, -22, -21, -21, -21, -20, -20, -20, -19, -19, -19, -18, -18, -18, -17, -17, -17, -16, -16, -16, -15, -15, -15, -14, -14, -14, -13, -13, -13, -12, -12, -11, -11, -11, -10, -10, -10, -9, -9, -9, -8, -8, -8, -7, -7, -7, -6, -6, -6, -5, -5, -5, -4, -4, -4, -3, -3, -3, -2, -2, -2, -1, -1, 0, 0, 0, 1, 1, 1, 2, 2, 2, 3, 3, 3, 4, 4, 4, 5, 5, 5, 6, 6, 6, 7, 7, 7, 8, 8, 8, 9, 9, 9, 10, 10, 11, 11, 11, 12, 12, 12, 13, 13, 13, 14, 14, 14, 15, 15, 15, 16, 16, 16, 17, 17, 17, 18, 18, 18, 19, 19, 19, 20, 20, 20, 21, 21, 22, 22, 22, 23, 23, 23, 24, 24, 24, 25, 25, 25, 26, 26, 26, 27, 27, 27, 28, 28, 28, 29, 29, 29, 30, 30, 30, 31, 31, 31, 32, 32, 33, 33, 33, 34, 34, 34, 35, 35, 35, 36, 36, 36, 37, 37, 37, 38, 38, 38, 39, 39, 39, 40, 40, 40, 41, 41, 41, 42, 42, 42, 43, 43 };
     const int Table_fu2[256]={ -227, -226, -224, -222, -220, -219, -217, -215, -213, -212, -210, -208, -206, -204, -203, -201, -199, -197, -196, -194, -192, -190, -188, -187, -185, -183, -181, -180, -178, -176, -174, -173, -171, -169, -167, -165, -164, -162, -160, -158, -157, -155, -153, -151, -149, -148, -146, -144, -142, -141, -139, -137, -135, -134, -132, -130, -128, -126, -125, -123, -121, -119, -118, -116, -114, -112, -110, -109, -107, -105, -103, -102, -100, -98, -96, -94, -93, -91, -89, -87, -86, -84, -82, -80, -79, -77, -75, -73, -71, -70, -68, -66, -64, -63, -61, -59, -57, -55, -54, -52, -50, -48, -47, -45, -43, -41, -40, -38, -36, -34, -32, -31, -29, -27, -25, -24, -22, -20, -18, -16, -15, -13, -11, -9, -8, -6, -4, -2, 0, 1, 3, 5, 7, 8, 10, 12, 14, 15, 17, 19, 21, 23, 24, 26, 28, 30, 31, 33, 35, 37, 39, 40, 42, 44, 46, 47, 49, 51, 53, 54, 56, 58, 60, 62, 63, 65, 67, 69, 70, 72, 74, 76, 78, 79, 81, 83, 85, 86, 88, 90, 92, 93, 95, 97, 99, 101, 102, 104, 106, 108, 109, 111, 113, 115, 117, 118, 120, 122, 124, 125, 127, 129, 131, 133, 134, 136, 138, 140, 141, 143, 145, 147, 148, 150, 152, 154, 156, 157, 159, 161, 163, 164, 166, 168, 170, 172, 173, 175, 177, 179, 180, 182, 184, 186, 187, 189, 191, 193, 195, 196, 198, 200, 202, 203, 205, 207, 209, 211, 212, 214, 216, 218, 219, 221, 223, 225 };
     *len = 3* nWidth * nHeight;
     if(!yuvBuf || !pRgbBuf)
         return false;
     const long nYLen = long(PIXELSIZE);
     const int nHfWidth = (nWidth>>1);
     if(nYLen<1 || nHfWidth<1)
         return false;
     // Y data
     unsigned char* yData = yuvBuf;
     // v data
     unsigned char* vData = &yData[nYLen];
     // u data
     unsigned char* uData = &vData[nYLen>>2];
     if(!uData || !vData)
         return false;
     int rgb[3];
     int i, j, m, n, x, y, pu, pv, py, rdif, invgdif, bdif;
     m = -nWidth;
     n = -nHfWidth;
     bool addhalf = true;
     for(y=0; y
         m += nWidth;
         if( addhalf ){
             n+=nHfWidth;
             addhalf = false;
         } else {
             addhalf = true;
         }
         for(x=0; x
             i = m + x;
             j = n + (x>>1);
             py = yData[i];
             // search tables to get rdif invgdif and bidif
             rdif = Table_fv1[vData[j]];    // fv1
             invgdif = Table_fu1[uData[j]] + Table_fv2[vData[j]]; // fu1+fv2
             bdif = Table_fu2[uData[j]]; // fu2
             rgb[0] = py+rdif;    // R
             rgb[1] = py-invgdif; // G
             rgb[2] = py+bdif;    // B
             j = nYLen - nWidth - m + x;
             i = (j<<1) + j;
             // copy this pixel to rgb data
             for(j=0; j<3; j++)
             {
                 if(rgb[j]>=0 && rgb[j]<=255){
                     pRgbBuf[i + j] = rgb[j];
                 }
                 else{
                     pRgbBuf[i + j] = (rgb[j] < 0)? 0 : 255;
                 }
             }
         }
     }
     return true;
 }

http://blog.csdn.net/wangjiannuaa/article/details/6572281