title: python opencv: no image
body: <p>I am trying to capture from a Sony Handicam DCR-HC38, running the code below, and passing [-1 .. 3] to the CaptureFromCAM function.  The code runs, but I get no image.  Do I need to "wrap" the camera somehow?  Skype recognizes the camera, but python/opencv won't.  I'm running Windows Vista if that helps any.</p>
  
  <pre><code>import cv
  
  cv.NamedWindow("camera", 1)
  
  capture = cv.CaptureFromCAM(-1)
  
  while True:
      img = cv.QueryFrame(capture)
      cv.ShowImage("camera", img)
      if cv.WaitKey(10) == 27:
          break
  </code></pre>