RGB24转YUV420

BOOL RGB2YUV(LPBYTE RgbBuf, UINT nWidth, UINT nHeight, LPBYTE yuvBuf, unsigned long *len)
{
    if (RgbBuf == NULL)
    {
        return FALSE;
    }

    int i, j;
    unsigned char*bufY, *bufU, *bufV, *bufRGB;
    memset(yuvBuf,,(unsigned int )*len);
    bufY = yuvBuf;
    bufV = yuvBuf + nWidth * nHeight;
    bufU = bufV + (nWidth * nHeight* /);
    *len = ;
    unsigned char y, u, v, r, g, b;
    unsigned int ylen = nWidth * nHeight;
    unsigned int ulen = (nWidth * nHeight)/;
    unsigned int vlen = (nWidth * nHeight)/;
    for (j = ; j<nHeight;j++)
    {
        bufRGB = RgbBuf + nWidth * (nHeight -  - j) *  ;
        for (i = ;i<nWidth;i++)
        {
            int pos = nWidth * i + j;
            r = *(bufRGB++);
            g = *(bufRGB++);
            b = *(bufRGB++);
            y = (unsigned char)( (  * r +  * g +   * b + ) >> ) +   ;
            u = (unsigned char)( ( - * r -   * g +  * b + ) >> ) +  ;
            v = (unsigned char)( (  * r -   * g -   * b + ) >> ) +  ;
            *(bufY++) = max( , min(y,  ));
            if (j%==&&i% ==)
            {
                if (u>)
                {
                    u=;
                }
                if (u<)
                {
                    u = ;
                }
                *(bufU++) =u;
                //存u分量
            }
            else
            {
                //存v分量
                if (i%==)
                {
                    if (v>)
                    {
                        v = ;
                    }
                    if (v<)
                    {
                        v = ;
                    }
                    *(bufV++) =v;
                }
            }
        }
    }
    *len = nWidth * nHeight+(nWidth * nHeight)/; 

    return TRUE;
}