OpenCV 图像格式BGR转 YUV420sp问题

一、OpenCV 图像格式转换为YUV420

         // yuv420sp format: CV_8UC1, cols: image_width, rows: image_height*3/2

         cv::cvtColor(image, yuv420sp, cv::COLOR_BGR2YUV_I420);

        注意: 上面这行代码转为YUV420后，Y、U、V都是单独平铺的,即 Y,Y,Y...   U,U,U... V,V,V...

二：转为YUV420sp, UV交叠

/*---------------------------------------------------------------------------
**  Convert image format: BGR to YUV420sp
**
**      YUV420sp:
**              Y  Y  Y   Y ...
**              U  V  U  V ...
** -------------------------------------------------------------------------*/
void    To_YUV420_SP(const cv::Mat &image, cv::Mat &yuv420sp)
{
    cv::cvtColor(image, yuv420sp, cv::COLOR_BGR2YUV_I420); // yuv420sp format: CV_8UC1, cols: image_width, rows: image_height*3/2

    cv::Mat  temp = yuv420sp.clone();
    const unsigned char *pU = temp.data + image.cols*image.rows;  // skip Y
    const unsigned char *pV = temp.data + image.cols*image.rows + image.cols*image.rows/4;  // skip Y and U

    unsigned char *pUV = yuv420sp.data + image.cols*image.rows;   // skip Y
    for(int j=0; j<image.cols*image.rows/4; j++){
        *pUV++ = *pU++;
        *pUV++ = *pV++;
    }
    return;
}