title: Select usb camera in cv2 in python
body: <p>I would like to access my web camera on my python program using cv2 library. </p>
  
  <p>I can see and use my camera in any mac program (photobooh, facetime,..) as well as skype,... </p>
  
  <p>But if I try to access it in python I can't:</p>
  
  <p>cap = cv</p>
  
  <pre><code>cv2.VideoCapture(1)
  success,image = cap.read() 
  print(success)
  &gt;&gt; False
  </code></pre>
  
  <p>I also try to get list of all devices (cameras) like this:</p>
  
  <pre><code>for i in range(1600):
      cap = cv2.VideoCapture(i)
      success,image = cap.read() 
      if success:
          print(i)
      cap.release()
  &gt;&gt; 0
  &gt;&gt; 1200
  </code></pre>
  
  <p>Both are default mac cameras,...</p>