View source for Accessibility/TimedText

[[File:Uhoh.jpg|thumb|Timing the text]]
== Resources relating to [http://www.w3.org/TR/2006/CR-ttaf1-dfxp-20061116/ W3C TimedText] ==

* [http://www.w3.org/TR/2003/WD-tt-af-1-0-req-20030915/ comprehensive requirements]
* [http://www.w3.org/TR/2006/CR-ttaf1-dfxp-20061116/#requirements DFXP satisfied requirements]
* [http://www.3gpp.org/ftp/Specs/archive/26_series/26.245/26245-700.zip 3GPP Timed Text]
* [http://www.w3.org/2006/DFXP/testsuite/Overview.html Test Cases]
* [http://www.w3.org/2005/03/21/DFXPLastCallResponses.html#Issue11 Discussion of open issues on DFXP]

== Interesting Features ==

=== DFXP ===

* head - body - separated document
* div, p and span elements to structure content; they all have begin, end and duration attributes; 
* a "region" element defines the area into which the text is to be rendered; multiple regions can be displayed at the same time and they can spatially overlap
* a "style" element defines a style for a region
* the region is then referred to from an div, p, or span element to define where and how to render the text
* a "layout" element groups metadata and regions
* had dynamic text display through dynamic flow style
* SMIL 2.1 based "set" element to control the animation of some other element
* SMIL 2.1 based "timeContainer" specification to specify local sequential or parallel child elements
* metadata specification possible in Dublin Core style

Example document: http://www.w3.org/TR/2006/CR-ttaf1-dfxp-20061116/#region-mapping-example-1-s

=== 3GPP 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