title: How can I display video as an overlay on markers detected by ARToolKit?
body: <p>I'm using ARToolKit to develop an iOS augmented reality application based on the detection of 2-D markers in the environment.  I'd like to be able to overlay video on these markers, but I'm not sure how to do this.</p>
  
  <p>How would I use ARToolKit to overlay video on specific markers within a live camera feed?</p>