title: Chromecast subtitle support
body: <p>Having played around alot with the Chromecast to find a good solution to closed captioning (in my project we already use TTML and segmented WEBVtt - both which does not work "as is") i was VERY supprised to find that my final bright idea, to manually add "new VTTCue()" to textTrack-element was unsupported.</p>
  
  <p>I've read alot of answers to questions here where the answer is along the lines of "do it yourselves" like this one <a href="https://stackoverflow.com/questions/19572313/does-chromecast-support-ttml">Does Chromecast support TTML?</a>. </p>
  
  <blockquote>
    <p>you can simply write a Javascript parser to parse the [ttml] file and add the cues to your video 
    element in javascript using methods such as addTextTrack(), etc</p>
  </blockquote>
  
  <p>Well, it does say that TTML IS supported here <a href="https://github.com/googlecast/CastClosedCaptioning-chrome" rel="nofollow noreferrer">https://github.com/googlecast/CastClosedCaptioning-chrome</a> but never mind.</p>
  
  <p>So having failed to power-google the answer (code alternatives to VTTCue) I turn to thee professionals - how can I add Cues seing that VTTCue is not supported?</p>
  
  <p>What I really really thought (hoped) would work:</p>
  
  <pre><code>loadTTML().done(function(ttml){
      var cueData = extractCueDataFromTTML(ttml);
      var vid = document.querySelector('video');
  
      vid.addTextTrack("subtitles", "sample");
      var track = vid.textTracks[0];
  
      cueData.forEach(function(cue){
          track.addCue(new VTTCue(cue.start, cue.end, cue.text))
      });
  })
  </code></pre>
  
  <p>Note:
  this is to avoid writing a TTML to WEBVtt converter or segmented WEBVtt combiner</p>