HTML5 kind attribute (subtitles, captions, metadata, descriptions, chapters)

Submitted by Brendan Long

Link to original bug (#698853)

Description

In HTML5, we need to mark text streams as subtitles, captions, metadata, descriptions or chapters, but there doesn't seem to be a way to do this in GStreamer. For audio and video tracks, there are also kinds: alternative, captions (legacy), description, main, main-desc, sign, subtitles (legacy), translation, and commentary.

For metadata, the caps will probably be different, but for everything else the caps would be the same.

The simplest solution seems to be to add a GST_TAG_KIND, which can contain any of the kinds defined in HTML5.

See:

http://www.whatwg.org/specs/web-apps/current-work/multipage/the-video-element.html#text-track-kind
http://www.whatwg.org/specs/web-apps/current-work/multipage/the-video-element.html#dom-audiotrack-kind