title: OpenCV can't capture the frame from the webcam
body: <p>I am using OpenCV 2.4.6 with VS2010.</p>
  
  <p>I think my webcam can't capture the frame. When I executed the code it built successfully, but I am not getting output. I think, when I check <code>if(!bSuccess)</code> it is executed and can't capture frame from the webcam. </p>
  
  <p>How can I resolve this problem? My code is below:</p>
  
  <pre>
  <code>
  #include "opencv2/highgui/highgui.hpp"
  #include 
  
  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  &lt&lt "Cannot open the video file" &lt&lt endl;
          return -1;
      }
  
     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 &lt&lt "Frame size : " &lt&lt dWidth &lt&lt " x " &lt&lt dHeight &lt&lt endl;
      namedWindow("MyVideo",CV_WINDOW_AUTOSIZE); //create a window called "MyVideo"
      while (1)
      {
         Mat frame;
         bool bSuccess = cap.read(frame); // read a new frame from video
         if (!bSuccess) //if not success, break loop
          {
           cout &lt&lt "Cannot read a frame from video file" &lt&lt endl;
              break;
          }
  
          imshow("MyVideo", frame); //show the frame in "MyVideo" window
  
          if (waitKey(30) == 27) 
          {
          cout &lt&lt "esc key is pressed by user" &lt&lt endl;
            break; 
          }
      }
      return 0;
  
  }
  </code>
  </pre>