According to the Release Notes (of July 8), the docs for the Sender and the updated answer of this question, the Styled Media Receiver of Google Cast does now support Closed Captioning or Subtitle tracks.
However, when I tell the Default or the Styled Media Receiver to show a text track, nothing happens. It does not even load the .vtt from the server, as I can see in the logs.
I can tell the receiver app got the text tracks just fine, but even using the Android example app, 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.
The MediaTrack is being created as follows:
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();
I have checked thrice that the file exists and is being loaded with the type text/vtt. But that does not matter, as the file is never even requested by the player. I have tried both MediaTrack.SUBTYPE_CAPTIONS and MediaTrack.SUBTYPE_SUBTITLES.
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?
If there is still a custom receiver required, I would like to know how to convert the example player to support subtitles, as it doesn't seem to support them either.
First, I suggest you change your wording in future posts (re: "..is simply a lie.."); that is not appropriate at all. Secondly, it works and you can test that with the CastVideos-android app (or ios variation of it for that matter); the first three videos have CC. Lastly, we have documentation on that subject on our documentation site (https://developers.google.com/cast/docs/android_sender, under "Using the Tracks API").