include "opencv2/highgui/highgui.hpp"

include"opencv2/core/core.hpp"

include"opencv2/imgproc/imgproc.hpp"

include<stdlib.h>

include <iostream>

#include "opencv2/highgui/highgui.hpp"
#include"opencv2/core/core.hpp"
#include"opencv2/imgproc/imgproc.hpp"
#include<stdlib.h>
#include <iostream>

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

    if (!cap.isOpened()) // if not success, exit program
{
 
    {
        cout << "ERROR: Cannot open the video file" << endl;
 return -1;
}
    }
    namedWindow("My",CV_WINDOW_AUTOSIZE); 
 double j=cap.get(CV_CAP_PROP_FPS);
 double width=cap.get(CV_CAP_PROP_FRAME_WIDTH);
 double height=cap.get(CV_CAP_PROP_FRAME_HEIGHT);
cout<<width&lt;<endl; size="" framesize(static_cast<int="">(width),static_cast<int>(height));
    cout<<width<<endl;
    Size framesize(static_cast<int>(width),static_cast<int>(height));
    VideoWriter ovid("D:\ashish.avi",CV_FOURCC('P','I','M','1'),20,framesize,true);
cout<<framesize; if(!ovid.isopened())="" {<="" p="">

    cout<<framesize;
    if(!ovid.isOpened())
    {

        system("pause");
 return -1;
 
}
 

    }

    while (1)
{
    {
        Mat frame;
 cap>>frame;
 ovid.write(frame);
 imshow("My", 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;
 
}0;
}

above code executes with no warning but no video is displays on window as well as no recording happens.