The DPP has agreed an industry document format standard for the exchange of subtitles for the hard of hearing and audio description.
Aligned with the EBU’s new subtitle document format (EBU-TT), produced in July 2012, the new standard has been created to support UK broadcasters’ requirements for subtitle and audio description script transfer.
The DPP’s subtitle document format extends EBU-TT with metadata required to support the workflow for delivering prepared subtitles and captured live subtitles in addition to the scripts used during the production of audio description.
All DPP subtitle documents are valid EBU-TT, itself based on the W3C TTML recommendation. The format separates the text and it’s associated display timing from information about that text, such as where it should be placed on the screen, the font style, size and colour, and separate metadata such as whether a given subtitle is describing dialogue, music, sounds effects etc., and what language the subtitles are in.
The format is a flavour of XML whose format can be validated using off the shelf tools and extended to meet specific requirements while still being interchangeable. In addition it can support all Unicode characters and arbitrary fonts, should downstream platforms support them. EBU is in the process of finalising the draft guidance for converting from the legacy STL format to EBU-TT.
DPP’s subtitle document format will allow UK broadcasters and access service providers to move away from legacy formats, proprietary or otherwise, and towards an open future-facing format that can be used to provide subtitles on broadcast television and online. By agreeing this format before making the transition, DPP is able to lay the groundwork for a common UK interchange format that will benefit all businesses that need to exchange these documents.
Companies that manufacture access services authoring and processing tools have a clear target format, which is vital in a historically fragmented marketplace. Broadcasters and distributors similarly will have a lower cost of adoption of this richer format that is not encumbered by the constraints of legacy formats.
Kevin Burrows, DPP Technical Standards Lead and CTO Broadcast & Distribution, Channel 4, said, “This new subtitle standard, encompassing the existing EBU TT specification, will allow for the display of subtitles on current and future consumer platforms by the UK broadcasters. T his will benefit viewers by enabling a consistent viewer experience across their services.”
Alan Whiston, DPP Board Member and Technology Controller, BBC Television, North & Nations, added, “This demonstrates the continued collaboration between broadcasters and standards bodies through the forum of the DPP. This is an essential step for enhancing the experience across platforms and services for the benefit of the audience.”