title: OpenCV frame capture from AVI
body: <p>I am working on a project with openCV 2.2.  I need to do processing on each frame of an AVI file but when I run my code it only grabs the first frame of the file.  The CV_CAP_PROP_POS_FRAMES does not seem to be working.  Any ideas why not?</p>
  
  <pre><code>    CvCapture* capture = cvCaptureFromAVI("test1.avi");
  
      IplImage *img = 0;
  
      if (!cvGrabFrame(capture)) {
              printf("Error: Couldn't open the image file.\n");
              return 1;
      }
  
      int numFrames = (int) cvGetCaptureProperty(capture, CV_CAP_PROP_FRAME_COUNT);
      int posFrame = 1;
      for(int i =0; i &lt;= numFrames; i++){
          cvSetCaptureProperty(capture, CV_CAP_PROP_POS_FRAMES, i);
                posFrame = cvGetCaptureProperty(capture, CV_CAP_PROP_POS_FRAMES);
  
                img = cvGrabFrame(capture);
                cvNamedWindow("Image:", CV_WINDOW_AUTOSIZE);
                cvShowImage("Image:", img);
                printf("%i\n",posFrame);
  
                cvWaitKey(0);
  
                cvDestroyWindow("Image:");
      }
  </code></pre>