Opecv实战之视频的读取与存储

以为为函数内部内容…

视频的读

system("color F0");  //更改输出界面颜色
    // 进行初始化，参数可以修改，0默认为本地摄像头，也可以把超参数选择为视频路径或者rtsp流
    cv::VideoCapture video(0);
    // 视频的状态为开
    if (video.isOpened())
    {
        cout << "视频中图像的宽度=" << video.get(cv::CAP_PROP_FRAME_WIDTH) << endl;
        cout << "视频中图像的高度=" << video.get(cv::CAP_PROP_FRAME_HEIGHT) << endl;
        cout << "视频帧率=" << video.get(cv::CAP_PROP_FPS) << endl;
        cout << "视频的总帧数=" << video.get(cv::CAP_PROP_FRAME_COUNT);
    }
    else
    {
        cout << "error!" << endl;
    }
    
    while (video.isOpened())
    {
        cv::Mat frame;
        // 将图片重载入视频
        video >> frame;
        if (frame.empty())
        {
            break;
        }
         // 显示图片函数
        cv::imshow("video", frame);
        // 延时操作
        cv::waitKey(30 );/// video.get(cv::CAP_PROP_FPS));
    }
    // 释放资源~
    video.release();
    // 销毁所有窗口
    cv::destroyAllWindows();

视频的存储

cv::Mat src;
    // use default camera as video source
    cv::VideoCapture cap(0);
    // check if we succeeded
    if (!cap.isOpened()) {
        cerr << "ERROR! Unable to open camera\n";
        return -1;
    }
    // get one frame from camera to know frame size and type
    cap >> src;
    // check if we succeeded
    if (src.empty()) {
        cerr << "ERROR! blank frame grabbed\n";
        return -1;
    }
    // 确定格式为8位3通道
    bool isColor = (src.type() == CV_8UC3);
    //--- INITIALIZE VIDEOWRITER
    cv::VideoWriter writer;
    // 确认编码
    int codec = cv::VideoWriter::fourcc('M', 'J', 'P', 'G');  // select desired codec (must be available at runtime)
    // 帧数
    double fps = 25.0;                          // framerate of the created video stream
    // 存储的文件名字
    string filename = "./live.avi";             // name of the output video file
    // 视频流初始化
    writer.open(filename, codec, fps, src.size(), isColor);
    // check if we succeeded
    if (!writer.isOpened()) {
        cerr << "Could not open the output video file for write\n";
        return -1;
    }
    //--- GRAB AND WRITE LOOP
    cout << "Writing videofile: " << filename << endl
         << "Press any key to terminate" << endl;
     // 死循环，可以替换成while(true)
    for (;;)
    {
        // check if we succeeded
        // 读取源
        if (!cap.read(src)) {
            cerr << "ERROR! blank frame grabbed\n";
            break;
        }
        // encode the frame into the videofile stream
        // 将视频流写入
        writer.write(src);
        // show live and wait for a key with timeout long enough to show images
        imshow("Live", src);
        if (cv::waitKey(5) >= 0)
            break;
    }
    // the videofile will be closed and released automatically in VideoWriter destructor
    return 0;