Question

#include "opencv2/highgui/highgui.hpp"
#include <iostream>

using namespace cv;
using namespace std;

int main(int argc, char* argv[])
{
    VideoCapture cap(0); // open the video camera no. 0

    if (!cap.isOpened())  // if not success, exit program
    {
        cout << "ERROR: Cannot open the video file" << endl;
        return -1;
    }

 namedWindow("MyVideo",CV_WINDOW_AUTOSIZE); //create a window called "MyVideo"

   double dWidth = cap.get(CV_CAP_PROP_FRAME_WIDTH); //get the width of frames of the video
   double dHeight = cap.get(CV_CAP_PROP_FRAME_HEIGHT); //get the height of frames of the video

   cout << "Frame Size = " << dWidth << "x" << dHeight << endl;

   Size frameSize(static_cast<int>(dWidth), static_cast<int>(dHeight));

 VideoWriter oVideoWriter ("D:/MyVideo.avi", CV_FOURCC('P','I','M','1'), 20, frameSize, true); //initialize the VideoWriter object 

   if ( !oVideoWriter.isOpened() ) //if not initialize the VideoWriter successfully, exit the program
   {
        cout << "ERROR: Failed to write the video" << endl;
        return -1;
   }

    while (1)
    {

        Mat frame;

        bool bSuccess = cap.read(frame); // read a new frame from video

        if (!bSuccess) //if not success, break loop
       {
             cout << "ERROR: Cannot read a frame from video file" << endl;
             break;
        }

         oVideoWriter.write(frame); //writer the frame into the file

        imshow("MyVideo", frame); //show the frame in "MyVideo" window

        if (waitKey(10) == 27) //wait for 'esc' key press for 30ms. If 'esc' key is pressed, break loop
       {
            cout << "esc key is pressed by user" << endl;
            break; 
       }
    }

    return 0;

}

我正在使用Visual Studio 2012 express和opencv_2.4.9以及windows 7 x64开发此项目。

但是，这段代码无效。

只需写出此消息“错误：无法编写视频”。

Answer 1

使用try，catch查看是否可以获得更详细的错误消息。

我在编写视频时记得的一件事是，您需要验证是否安装了编解码器并将其添加到正确的目录中，或者添加为PATH环境变量。

opencv_ffmpeg.dll对我来说是个问题，并确保它位于正确的目录中并重命名为opencv_ffmpeg249.dll

如何使用opencv2.4.9录制网络摄像头视频？

1 个答案: