title: Cast Receiver App does not show subtitles
body: <p>According to the <a href="https://developers.google.com/cast/docs/release-notes" rel="nofollow noreferrer">Release Notes</a> (of July 8), the docs for the <a href="https://developers.google.com/cast/docs/chrome_sender" rel="nofollow noreferrer">Sender</a> and the updated answer of <a href="https://stackoverflow.com/questions/23549445/chromecast-subtitles-on-default-receiver-applications">this question</a>, the Styled Media Receiver of Google Cast does now support Closed Captioning or Subtitle tracks.</p>
  
  <p>However, when I tell the Default or the Styled Media Receiver to show a text track, nothing happens. It does not even load the <code>.vtt</code> from the server, as I can see in the logs.</p>
  
  <p>I can tell the receiver app got the text tracks just fine, but even using the <a href="https://github.com/googlecast/CastVideos-android" rel="nofollow noreferrer">Android example app</a>, the subtitles never show up. According to all the logs, they are being sent and the receiver app is told to show them - but they never appear, they are never even loaded.</p>
  
  <p>The <code>MediaTrack</code> is being created as follows:</p>
  
  <pre><code>new MediaTrack.Builder(2, MediaTrack.TYPE_TEXT)
               .setName("Deutsch")
               .setSubtype(MediaTrack.SUBTYPE_CAPTIONS)
               .setContentId("https://example.com/video/caption_de.vtt")
               .setContentType("text/vtt")
               .setLanguage("de").build();
  </code></pre>
  
  <p>I have checked thrice that the file exists and is being loaded with the type <code>text/vtt</code>. But that does not matter, as the file is never even requested by the player. I have tried both <code>MediaTrack.SUBTYPE_CAPTIONS</code> and <code>MediaTrack.SUBTYPE_SUBTITLES</code>.</p>
  
  <p>So I need to know, is this claimed support of CC in the Styled Media Receiver simply a lie? Or is there some undocumented trick required to make it possible?</p>
  
  <p>If there is still a custom receiver required, I would like to know how to convert the <a href="https://github.com/googlecast/Cast-Player-Sample" rel="nofollow noreferrer">example player</a> to support subtitles, as it doesn't seem to support them either.</p>