ADOPTING NEW ADOPTING NEW SUBTITLE SUBTITLE FORMATS TO FORMATS TO MEET AUDIENCE MEET AUDIENCE NEEDS NEEDS NIGEL MEGITT, IRT SUBTECH1 SYMPOSIUM 25 MAY 2018
ADOPTING NEW SUBTITLE FORMATS TO MEET AUDIENCE NEEDS 2 A BIT ABOUT THE PRESENTER NIGEL MEGITT Executive Product Manager, Design + Engineering, BBC Other roles: Co-Chair, W3C Timed Text Working Group Co-Chair, EBU Timed Text Group Contributor to many others…
ADOPTING NEW SUBTITLE FORMATS TO MEET AUDIENCE NEEDS 3 A BRIEF HISTORY OF AUDIENCE EXPECTATIONS
ADOPTING NEW SUBTITLE FORMATS TO MEET AUDIENCE NEEDS 4 A BRIEF HISTORY OF AUDIENCE EXPECTATIONS SUBTITLES: THE EARLY DAYS Around 40 years ago, the BBC began broadcasting subtitles using the excellent new Teletext system. Electronic text displays were basic, and this system provided readable text in a small number of colours with some positioning. Great! Over the years broadcasters like the BBC integrated the Teletext into their work fl ows, standardising on storage formats (STL), and using ad hoc systems for inserting live subtitles (e.g. Nufor), and specifying how to carry the teletext in scanning video streams in ancillary data sections (SDI).
ADOPTING NEW SUBTITLE FORMATS TO MEET AUDIENCE NEEDS 5 A BRIEF HISTORY OF AUDIENCE EXPECTATIONS MEANWHILE… … the audience began to get used to computers that could produce nice looking text at home. The old monospaced Teletext font began to look a bit dated. DVB created a bitmap speci fi cation that encoders could generate from the Teletext source data, to make the text look nicer. Some platforms like Sky rendered the Teletext in the client device. The common backbone to the work fl ow of Teletext remained though.
ADOPTING NEW SUBTITLE FORMATS TO MEET AUDIENCE NEEDS 6 A BRIEF HISTORY OF AUDIENCE EXPECTATIONS BEGINNING TO LOOK A BIT WRONG? Display Unicode characters like € , ♫ , 🤕 Teletext was great, but in 2018 it doesn’t quite look fi t for purpose. Use a wide variety of colours It can’t do some things that we need for Di ff erent fonts, including proportionally spaced global use – on the right are just a few. Precise positioning These are things that the web can do that the audience now just expects . Begin at the le fu edge Your phone can do these! Handle bidirectional text םולש More importantly, they are necessary Or vertical, or Ruby… for making video accessible. Work nicely on the web Carry metadata
ADOPTING NEW SUBTITLE FORMATS TO MEET AUDIENCE NEEDS 7 BROADCASTER INFRASTRUCTURE
ADOPTING NEW SUBTITLE FORMATS TO MEET AUDIENCE NEEDS 8 BROADCASTER INFRASTRUCTURE Processing (minor) BBC SUBTITLE WORKFLOWS – CURRENT (2018) Conversion (major) Subtitle inserter Prepared workflow NUFOR Live workflow (1) Shortform (iPlayer exclusive, clips) Broadcast Subtitler STL Playout Teletext (VANC) Coding & DVB Bitmap & Teletext TV (Red Bee) Multiplexing EBU-TT with Teletext VANC embedded STL (2) Digital archive EBU-TT with File delivery embedded STL EBU-TT-D (live to VOD) Media Encode receiving BBC Standard and Package “TTML” (3) BBC R&D system Media Player services STL Internal Web Subtitler EBU-TT-D (clips etc) production/ EBU-TT-D (BBC?) CMS tools 6 formats, 3 conversion points.
ADOPTING NEW SUBTITLE FORMATS TO MEET AUDIENCE NEEDS 9 BROADCASTER INFRASTRUCTURE Processing (minor) BBC SUBTITLE WORKFLOWS - VISION Conversion (major) Subtitle inserter Prepared workflow Live workflow Shortform (iPlayer exclusive, clips) DVB Bitmap File delivery Broadcast EBU-TT (prepared) Subtitler & Teletext receiving EBU-TT Playout EBU-TT pt 3 Coding & TV (Red Bee) & DVB TTML system Multiplexing EBU-TT (live captured) EBU-TT pt 3 Media Encode EBU-TT-D (VOD) BBC Standard Archive Digital archive EBU-TT and Package Media Player, Search services Freeview Play EBU-TT-D in DASH (stream) EBU-TT-D Internal Web Subtitler EBU-TT-D production/ EBU-TT-D (BBC?) CMS tools 2 file formats, 1 conversion point.
ADOPTING NEW SUBTITLE FORMATS TO MEET AUDIENCE NEEDS 10 LONGER TERM IP EVERYWHERE? The broadcast industry seems to be heading strategically Everything is just an object. Subtitles were objects first! towards: • IMF for mastering and archive • IP streams (e.g. SMPTE 2110) for playout and live This means that we are generally heading towards a de- embedded future, where subtitles are not embedded directly into other media. But there may be a case for doing that with e.g. MXF deliverables intended for playout. This doesn’t change the vision for subtitles, but it might have a big impact on how subtitle streams are carried and how the audio and video are managed.
ADOPTING NEW SUBTITLE FORMATS TO MEET AUDIENCE NEEDS 11 LONGER TERM THE CLOUD! Quite a lot of Teletext-based solutions depend on physical hardware, for example to insert subtitles into an SDI stream. We are moving more and more towards cloud based solutions, especially for providing web-based streams. We just can not spin up and spin down processing instances when there’s a dependency on a limited number of physical machines. Whatever solution we choose needs to be so fu ware and IP network based so we can choose the right deployment model.
ADOPTING NEW SUBTITLE FORMATS TO MEET AUDIENCE NEEDS 12 ADOPTING NEW STANDARDS
ADOPTING NEW SUBTITLE FORMATS TO MEET AUDIENCE NEEDS 13 ADOPTING NEW STANDARDS WHICH STANDARDS? There are a lot of subtitle formats (not so many standards)! Our preferred choice is the TTML family. We helped make it, initiating the work in W3C back in 2003, and have worked with W3C and EBU since to create pro fi les that meet our BBC prefers: needs, and the needs of our audience. • Open standards – freely available, developed in an open process TTML pro fi les include EBU-TT, EBU-TT Live, SMPTE-TT, • As few standards as possible, or minimal transcode IMSC, ARIB-TT etc. requirements • Technology that fi ts business processes Industry seems to be converging on TTML globally: • IMSC in MPEG CMAF and IMF (even on iOS!) The standard needs to support: • EBU-TT-D and IMSC in DVB TTML • Everything Teletext can do, and the things it can’t do • EBU-TT-D in HbbTV 2.0, Freeview Play • Prepared subtitles • IMSC in ATSC 3.0 • Live subtitles • Hard of hearing and translation • Broadcast and web distribution and playback • Support for the whole broadcast work fl ow, i.e. the right timing and supporting metadata.
ADOPTING NEW SUBTITLE FORMATS TO MEET AUDIENCE NEEDS 14 ADOPTING NEW STANDARDS DO WE NEED MORE STANDARDS SUPPORT? Mostly no, the standards are in a pretty good state, and have maintenance routes. One missing area is for subtitles in IP infrastructure: • EBU-TT Live in SMPTE 2110? That’s good for de-embedded work fl ows, but another where questions are o fu en asked is where subtitles are embedded into AV assets: • TTML in MXF? Some work may be needed, not sure. • EBU-TT Live in SDI? Might be a short term gain, possibly not worth it if we’re going straight to SMPTE-2110.
ADOPTING NEW SUBTITLE FORMATS TO MEET AUDIENCE NEEDS 15 ADOPTING NEW STANDARDS STEPS ALONG THE WAY Workflow step What we want Can we use? Authoring EBU-TT + EBU-TT Live OK Archive and Exchange EBU-TT OK Playout EBU-TT + EBU-TT Live No support Encoding for broadcast EBU-TT Live -> multiple No commercial options Broadcast Distribution EBU-TT-D/IMSC Poor support? Broadcast Player EBU-TT-D/IMSC OK + more coming Online Distribution EBU-TT-D/IMSC OK Online Player EBU-TT-D/IMSC OK
ADOPTING NEW SUBTITLE FORMATS TO MEET AUDIENCE NEEDS 16 ADOPTING NEW STANDARDS HOW LONG WILL IT TAKE? Broadcast infrastructure seems to cost a lot and be refreshed as rarely as the business thinks it can get away with. There may in the future be disruptors that o ff er new cheaper ways to implement broadcast work fl ows. Assuming there are not, we will need to work with our major suppliers to make sure any new functionality is either built into existing equipment or included in any technical refresh projects. O fu en there is a “chicken-and-egg” problem! Result: likely to take years rather than months.
ADOPTING NEW SUBTITLE FORMATS TO MEET AUDIENCE NEEDS 17 CONCLUSIONS
ADOPTING NEW SUBTITLE FORMATS TO MEET AUDIENCE NEEDS 18 CONCLUSIONS WE’RE ON THE WAY We know the engineering problems we Calls to action: want to solve. • if you’re buying new kit, consider moving to new standards. We know how we want to solve them. • If you’re selling kit, put this on your The technical standards are mostly in development roadmap. place. • If you’re representing the audience, let There is momentum towards your broadcasters (and maybe even convergence in the industry. regulator) know what you would like to see and what editorial proposition you We have more work to do speci fi cally in would like. automated playout and in encoders and packagers.
+ + D E THANK YOU! NIGEL MEGITT nigel.megitt@bbc.co.uk
ADOPTING NEW SUBTITLE FORMATS TO MEET AUDIENCE NEEDS 20 ONWARD… MORE INFORMATION BBC Subtitle Guidelines: http://bbc.github.io/subtitle-guidelines/ BBC Academy Guide “How to create subtitles”: http://www.bbc.co.uk/guides/zmgnng8 BBC R&D publications on accessibility: https://www.bbc.co.uk/rd/topics/accessibility
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