.net: What is TTML?
JF: #TTML (Timed Text Markup Language) is a #W3C Standard finalised in 2010, but was many years in the making. An XML-based language, it contains a rich set of features and capability of expression. Significant contributions to TTML were made by representatives of Samsung, Microsoft, Apple, the BBC, WGBH/NCAM and RealNetworks. Flash-based players from companies such as Adobe and Longtail Video (the JW FLV Player) provide native support for TTML files today.
Most recently, the Society of Motion Picture and Television Engineers (SMPTE) created a superset of TTML called SMPTE Timed Text which added some additional capabilities to address legacy meta-data requirements from their constituents.
.net: And what about WebVTT?
JF: #WebVTT (Web Video Text Tracks) is a time-stamp format intended for marking up external text track resources. It’s copyrighted by Apple Computer, Inc, Mozilla Foundation, and Opera Software ASA, although liberally licensed.
The principal author is Ian Hickson, and it’s heavily based on the SRT time-stamp format, which emerged from the fan-sub community (primarily in Europe) who were using it to create and share unauthorised subtitles to movie torrents and similar content.
