title: How to open IP Camera Url by OpenCV and python?
body: <p>I have install opencv on MacX(Lion) with ffmpeg support</p>
  
  <pre><code>import cv2
  import cv
  import base64
  import time
  import urllib2
  import numpy as np
  
  from cv2 import __version__
  
  print(__version__)
  video="http://xxx.223.91.91/mjpg/1/video.mjpg?dummy=param.avi"
  vv = cv.CaptureFromFile(video)
  cv2.namedWindow("preview")
  vc = cv2.VideoCapture("http://xxx.223.91.91/mjpg/1/video.mjpg?dummy=param.mjpg")
  </code></pre>
  
  <p>but Show WARNING</p>
  
  <p>2.4.2</p>
  
  <p>WARNING: Couldn't read movie file <a href="http://xxx.223.91.91/mjpg/1/video.mjpg?dummy=param.avi" rel="nofollow">http://xxx.223.91.91/mjpg/1/video.mjpg?dummy=param.avi</a></p>
  
  <p>WARNING: Couldn't read movie file <a href="http://xxx.223.91.91/mjpg/1/video.mjpg?dummy=param.mjpg" rel="nofollow">http://xxx.223.91.91/mjpg/1/video.mjpg?dummy=param.mjpg</a></p>
  
  <p>I Google a lot of code, but could not find a solution to the problem.
  Please help me, thank you.</p>