title: how to use a video stream as input in python/opencv programme
body: <p>I am able to stream and receive webcam feed in two terminal via udp</p>
  
  <p>command for streaming:</p>
  
  <pre><code>ffmpeg -i /dev/video0 -b 50k -r 20 -s 858x500 -f mpegts udp://127.0.0.1:2000  
  </code></pre>
  
  <p>command for recieving:</p>
  
  <pre><code>ffplay  udp://127.0.0.1:2000 
  </code></pre>
  
  <p>Now i have to use this received video stream as input in python/opencv how can i do that.
  I will be doing this using rtp and rstp as well.
  But in case of rtsp it is essential to initiate the receiving terminal, but if I do that then port will become busy and my program will not be able to take the feed.How could it be resolved. 
  I am currently using opencv 2.4.13, python 2.7 in ubuntu 14.04</p>