DVB Blue Book on TTML Subtitling Systems

I just noticed that DVB has published a Blue Book (A174) titled Digital Video Broadcasting (DVB): TTML Subtitling Systems, available at:

https://www.dvb.org/resources/public/standards/a174_dvb_ttml_subtitling_systems.pdf

It specifies the carriage of TTML in DVB MPEG-2 Transport Streams. It allows TTML profiles to be signalled using short codes, and specifies a default conformance point that is the intersection of EBU-TT-D and IMSC 1. It also supports downloadable fonts.

DVB Blue books are typically published in advance of, and as the basis for, an ETSI standard.

Kind regards,

Nigel