OpenCV 播放视频文件

OpenCV播放视频文件

使用cv::VideoCapture类来读取视频文件，并用cv::imshow逐帧播放视频。

版本一：使用c api

int playVideoTest(const std::string & videoPath )
{
    
    CvCapture* capture;
    capture = cvCreateFileCapture(videoPath.c_str());
    
    if (!capture)
        return -100;
    
    double rate= (double)cvGetCaptureProperty( capture , CV_CAP_PROP_FPS);
    bool stop(false);
    IplImage* frame = NULL; 
    cvNamedWindow("Extracted Frame");
    int delay= 1000/rate;

    while (!stop) {
        frame = cvQueryFrame(capture);
        if (!frame)
            break;
        cvShowImage("Extracted Frame",frame);
        if (cvWaitKey(delay)>=0)
            stop= true;
    }
    cvDestroyWindow("Extracted Frame");
    cvReleaseCapture(&capture);
    return 1;
}

注：不知道如何释放frame空间，使用cvReleaseImage()和cvReleaseImageHeader()均会出错。

版本二：使用c++ api

int playVideo( const std::string & videoPath )
{
    cv::VideoCapture capture(videoPath)
        if (!capture.isOpened())
        return -1;

    double rate= capture.get(CV_CAP_PROP_FPS);

    bool stop(false);

    cv::Mat frame; 
    cv::namedWindow("Extracted Frame");
    int delay= static_cast<int>(1000/rate);
    
    while (!stop) {
        if (!capture.read(frame))
            break;
        cv::imshow("Extracted Frame",frame);
        if (cv::waitKey(delay)>=0)
            stop= true;
    }
    cv::destroyWindow("Extracted Frame");
    capture.release();
    return 1;
}