小编Ben*_*n S的帖子

我正在尝试使用以下代码使用 openCV 2.4.6.1 修改和编写一些视频：

cv::VideoCapture capture( video_filename );

    // Check if the capture object successfully initialized
    if ( !capture.isOpened() ) 
    {
        printf( "Failed to load video, exiting.\n" );
        return -1;
    }

    cv::Mat frame, cropped_img;

    cv::Rect ROI( OFFSET_X, OFFSET_Y, WIDTH, HEIGHT );


    int fourcc = static_cast<int>(capture.get(CV_CAP_PROP_FOURCC));
    double fps = 30;
    cv::Size frame_size( RADIUS, (int) 2*PI*RADIUS );
    video_filename = "test.avi";
    cv::VideoWriter writer( video_filename, fourcc, fps, frame_size );

    if ( !writer.isOpened() && save )
    {
        printf("Failed to initialize video writer, unable to save …