opencv 如何缩放 YUV420 数据
我从文件中读取 一帧 yuv420 的数据，保存到一个数组中，
请问 如何使用opencv 对yuv数据进行缩放？
或者不用opencv 使用其他的函数？
[解决办法]
yuv转rgb的函数：

void YUV420_C_RGB( char* pYUV, unsigned char* pRGB, int height, int width)
{
    char* pY = pYUV;
    char* pU = pYUV+height*width;
    char* pV = pU+(height*width/4);


    unsigned char* pBGR = NULL;
    unsigned char R = 0;
    unsigned char G = 0;
    unsigned char B = 0;
    char Y = 0;
    char U = 0;
    char V = 0;
    double tmp = 0;
    for ( int i = 0; i < height; ++i )
    {
        for ( int j = 0; j < width; ++j )
        {
            pBGR = pRGB+ i*width*3+j*3;

            Y = *(pY+i*width+j);
            U = *pU;
            V = *pV;

            //B
            tmp = MB(Y, U, V);
            //B = (tmp > 255) ? 255 : (char)tmp;
            //B = (B<0) ? 0 : B;
B = (unsigned char)tmp;
            //G
            tmp = MG(Y, U, V);
            //G = (tmp > 255) ? 255 : (char)tmp;
           // G = (G<0) ? 0 : G;
G = (unsigned char)tmp;
            //R
            tmp = MR(Y, U, V);
            //R = (tmp > 255) ? 255 : (char)tmp;
            //R = (R<0) ? 0 : R;
R = (unsigned char)tmp;


            *pBGR     = R;            
            *(pBGR+1) = G;        
            *(pBGR+2) = B;
        

            if ( i%2 == 0 && j%2 == 0)
            {
                *pU++;
//*pV++;
            }
            else
            {
                if ( j%2 == 0 )
                {
                    *pV++ ;
                }
}
        }
    
    }
} 
 

cvResize


[解决办法]
OpenCV的话：
YUV->IplImage->缩放->转换回YUV
可参考：YUV转IPLImage（RGB）

或者使用ffmpeg的swscale可以直接实现
可参考：FFMPEG 实现 YUV，RGB各种图像原始数据之间的转换（swscale）