opencv write webcam output to avi file

Question

I am trying to create an avi video from my webcam output using opencv. No exceptions are thrown, however the avi file it creates is 414 bytes in size and does not grow.

Answer 1

Dont use outdated C, use C++ api, it is easy to use and simple, for example the above code can be rewritten in C++ like,

#include "opencv2/opencv.hpp"
#include 

using namespace std;
using namespace cv;

int main(){

    VideoCapture vcap(0); 
      if(!vcap.isOpened()){
             cout << "Error opening video stream or file" << endl;
             return -1;
      }

   int frame_width=   vcap.get(CV_CAP_PROP_FRAME_WIDTH);
   int frame_height=   vcap.get(CV_CAP_PROP_FRAME_HEIGHT);
   VideoWriter video("out.avi",CV_FOURCC('M','J','P','G'),10, Size(frame_width,frame_height),true);

   for(;;){

       Mat frame;
       vcap >> frame;
       video.write(frame);
       imshow( "Frame", frame );
       char c = (char)waitKey(33);
       if( c == 27 ) break;
    }
  return 0;
}