EBU-TT stands for EBU Timed Text. It is an XML-based subtitling format intended as a follow-up to the currently widely used EBU STL format ( EBU Tech 3264). In 2012, version 1.0 of EBU-TT part 1 was published (EBU Tech 3350) . This specification defines an easy-to-use XML structure for the interchange and archiving of subtitles. It builds on the W3C Timed text Markup Language (TTML) 1.0 .
To help developers get started, an XML Schema implementation of EBU-TT part 1 is available too. Please note that the XML Schema is informative and cannot guarantee 100% conformance to the spec, so EBU Tech 3350 stays the normative reference. EBU-TT part 2 ( EBU Tech 3360 ) is a mapping guide on how to map EBU STL files to EBU-TT. It was published in June 2013 as a v0.9 for comments. The EBU has also developed a recommendation on the transport of subtitles inside and outside MXF files ( EBU R 133 ).
In January 2014 the EBU published EBU-TT-D ( EBU Tech 3380 ), the format for the distribution of subtitles over IP. There also is a document for the use of EBU-TT-D in ISO BMFF / MPEG-DASH ( EBU Tech 3381 v0.9 ).
The EBU Subtitling Group ( MIM-XMLSubs ) is now focussed on a solution for the production/contribution of live subtitling.