<!DOCTYPE html>
<html lang=en>
 <head>
 <script type="application/its+xml">  
 <its:rules xmlns:its="http://www.w3.org/2005/11/its" xmlns:h="http://www.w3.org/1999/xhtml"  version="2.0">
 <its:param name="externalresourceParam">video-image.png</its:param>
 <its:externalResourceRefRule selector="//h:video[@poster=$externalresourceParam]" externalResourceRefPointer="@src"/>
 </its:rules>
 </script>
  <meta charset=utf-8> 
  <title>Video element example</title>
 </head>
 <body>
  <video
    width="640"
    height="360"
    src="http://www.example.com/video/v2.mp"
    poster="video-image.png">If your browser doesn't support the <code>video</code> element, you can <a href="http://www.example.com/video/v2.mp">download the video</a> instead.</video>
 </body>
</html>