Accessibility/TimedText

Resources relating to W3C TimedText

This specification defines the subpart of the DFXP authoring language that is supported on 3GPP and how it maps into the 3GPP file format.

each timed text track defines a region with width, height, translation
within the region is defined a text box set into which captions are rendered
styling is applied to the region and/or the text box(es)
there is a "layer" value that decides between timed text tracks and video tracks the order of display layers
i18n is achieved with language spec, writing direction, and character set support
marquee-scrolling (ticker scrolling) is defined through scroll-in, scroll-out, scroll-delay attributes, scroll speed depends on the duration of this text segment
dynamic highlighting as in Karaoke or Closed Captions is mentioned
soft text wrap from line to line is supported to fit text within a text box
outgoing hyperlinks are supported by attributing them to text boxes
media mapping is defined for MPEG-4