||The EBU Group on Subtitles in XML has created the EBU-TT format, which provides a W3C TTML based way to exchange and archive subtitles. EBU-TT is a follow-up for the well-known EBU STL format.|
Subtitling is used extensively by broadcasters, both for foreign-language subtitling and as an access service to help people with a disability access television programmes. The creation of subtitles has long used stand-alone file formats, including the well-known EBU Tech 3264 ('EBU STL') and many proprietary formats.
EBU Timed Text (EBU-TT)
For today's IT-centric world, EBU Tech 3264 is out-dated and limited in terms of functionality (e.g. the characters which are supported). At the same time new distribution platforms, such as subtitling for online applications, ask for an XML-based format. Added to that broadcasters are switching to fully file-based (e.g. MXF) operations.
These are the three main reasons which have pushed the EBU group to develop an XML-based format for use in subtitling production and exchange, based on W3C's Timed Text Markup Language (TTML) v1.0. The spec is called EBU-TT (EBU Tech 3350) . In June 2013, EBU-TT part 2 v0.9 was published. This specification provides a mapping from STL to EBU-TT. An XML Schema and example files are also available to help developers implement EBU-TT.
EBU-TT-D for distribution
In January 2014, EBU-TT-D was published ( EBU Tech 3380 ). This subtitling format is for the distribution of subtitles over IP. A mapping document to ISO BMFF (MPEG-DASH) is also available ( EBU Tech 3381 v0.9 ).
The EBU group is currently working on Live Subtitling (EBU-TT part 3).