TTML Content may also be used directly as a distribution format and is widely supported in media players, with the exception of major web browsers, where WebVTT, the second W3C standard for timed text in online media, has better built-in support in connection with the HTML5
The idea of adding timing information on the Web by extending HTML [2] came very early on, out of the work done on the Synchronized Multimedia Integration Language.
[5] In February 2012 the FCC declared the SMPTE closed-captioning standard for online video content, a superset of TTML, as a "safe harbor interchange, delivery format".
[6] In 2015, Netflix, Home Box Office (HBO), Telestream, SMPTE, and W3C received a Technology & Engineering Emmy Award for the category “Standardization and Pioneering Development of Non-Live Broadband Captioning,” for their work on TTML.
This profile defines the minimum feature requirements that a transformation processor (e.g. caption converter) needs to support in order to be considered TTML compliant.
This profile defines the minimum feature requirements that a presentation processor (e.g. video player) needs to support in order to be considered TTML compliant.
Interoperability with pre-existing and regionally-specific formats (such as CEA-708, CEA-608, DVB Subtitles, and WST (World System Teletext)) is provided by means of tunneling data or bit map images and adding necessary metadata.