title: Can't get VideoCapture property as the property identifier are not defined
body: <p>I am trying to process frames in a video file, and to know what is the current frame position in the video.</p>
  
  <pre><code>cap = cv2.VideoCapture('Videos/IMG_2483.MOV')
  print("Position : %d" % cap.get(cv2.CV_CAP_PROP_POS_MSEC))
  </code></pre>
  
  <p>I keep getting this error : </p>
  
  <pre><code>AttributeError: 'module' object has no attribute 'CV_CAP_PROP_POS_MSEC'
  </code></pre>
  
  <p>I guess I am wrongly calling the attribute "CV_CAP_PROP_POS_MSEC". I've been looking everywhere but I can't figure it out.</p>
  
  <p>Thanks in advance!</p>