title: HTML5 Graphics in Subtitles using Webvtt
body: <p>I'm trying to achieve having little graphics in the video subtitles (Webvtt format) displayed by the <code>&lt;track&gt;</code>-Element in HTML5 (using Chrome).
  I tried it with CSS so far using <code>content:url()</code> or <code>background-image:url()</code> but wasn't successful.
  Does somebody have any ideas or tips how I can solve my problem?</p>
  
  <p>Thanks in advance</p>