The latest release of the EBU-TT Live Interoperability Toolkit (LIT) includes a raft of new or enhanced features that allow anyone to quickly and easily set up a complete live subtitling test chain. The toolkit consists of a repository of open source software modules and tests that can be used by broadcasters, service providers, developers, and others to develop specification-conformant products and to validate the EBU-TT Live Subtitling specification (EBU Tech 3370) which aims to improve the interoperability of live subtitling solutions for broadcasters and content providers.
Release 2 provides a complete set of components for generating, validating and distributing live subtitles. Using one of the provided sample configuration files, an EBU-TT live subtitling environment can be created with a single command. A range of BDD (Behaviour Driven Development) tests to verify the implementation against the specification are part of the repository. Also included are a very basic test web-based authoring tool, an automated producer of test live subtitles, a distributor, two kinds of delay nodes, a basic validating consumer node, a "resequencer" and an EBU-TT-D encoder, and a carriage mechanism (Websockets). The toolkit itself is accompanied by comprehensive documentation that includes both detailed setup instructions and high-level explanations of design decisions.
EBU-TT Part 3 is currently undergoing the final stages of review and this release of the LIT implements most of the specification. The next release will include all the remaining components described in the specification as well as any final changes and will constitute a complete reference implementation. By providing the toolkit, the EBU aims to help both users and solution providers trialling and adopting the EBU-TT Live specification.