title: capture h264 to buffer with openCV
body: <p>I retrieve an rtp H264 stream. I process like this :
  - get Udp packet
  - remove rtp header and parse packet to get image
  - record/append image into a file
  - open this file with opencv (bool VideoCapture::open(const string&amp; filename))</p>
  
  <p>and all is working fine!!</p>
  
  <p>Now I want to skip the record in the file step and directly send image from udp process to opencv. But i don't know how initialise opencv with an input buffer. It only accept const string&amp; filename.</p>
  
  <p>Could somebody help me?</p>
  
  <p>Thanks</p>