ADOPTING NEW SUBTITLE FORMATS TO MEET AUDIENCE NEEDS NIGEL MEGITT, IRT SUBTECH1 SYMPOSIUM 25 MAY 2018

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1 ADOPTING NEW SUBTITLE FORMATS TO MEET AUDIENCE NEEDS NIGEL MEGITT, IRT SUBTECH1 SYMPOSIUM 25 MAY 2018

2 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

3 3 A BRIEF HISTORY OF AUDIENCE EXPECTATIONS

Ofcom took over from the ITC they have commissioned research on subtitling speed (11) view to revising the ITC guidelines, which they published following a public consultation in These new guidelines

4 Ofcom took over from the ITC they have commissioned research on subtitling speed (11) view to revising the ITC guidelines, which they published following a public consultation in These new guidelines are considerably shorter than the ITC document, removing the ce ona editing and formatting of subtitles. However, they still contain some legacy issues BRIEF HISTORY OF AUDIENCE EXPECTATIONS ed from Teletext (12). Since 2013 Ofcom has been focusing on a programme of work SUBTITLES: THE EARLY DAYS ring the quality of live subtitling (13). ADOPTING NEW SUBTITLE FORMATS TO MEET AUDIENCE NEEDS 40 years ago, the BBC began broadcasting subtitles TheAround Changing Media Landscape using the excellent new Teletext system. 9 BBCElectronic Online published a set of text displays were basic, and this system provided readable textthe in a small number ofrequirements colours with some nes outlining subtitling positioning. Great! content presented on the bbc.co.uk web 4). These were based on Over the years broadcasters likeexisting the BBC integrated the Teletext into their workﬂows, standardising ion subtitle guidelines and existingon storage formats (STL), and using ad hoc systems for inserting live ch (5,subtitles 6, 15). have been reviewing (e.g.we Nufor), and specifying how to carry the teletext in scanning video streams in ancillary data sections (SDI). idity of this guidance for the new viewing ms and viewing contexts. With television mmes available on computers and le devices the context for television g is a more individual experience and 4

ADOPTING NEW SUBTITLE FORMATS TO MEET AUDIENCE NEEDS A BRIEF HISTORY OF AUDIENCE EXPECTATIONS MEANWHILE the audience began to get used to computers that could produce nice looking text at home.

5 ADOPTING NEW SUBTITLE FORMATS TO MEET AUDIENCE NEEDS 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 speciﬁcation 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 workﬂow of Teletext remained though. 5

Your phone can do these! More importantly, they are necessary for making video accessible.

6 6 A BRIEF HISTORY OF AUDIENCE EXPECTATIONS BEGINNING TO LOOK A BIT WRONG? Teletext was great, but in 2018 it doesn t quite look fit for purpose. It can t do some things that we need for global use on the right are just a few. These are things that the web can do that the audience now just expects. Your phone can do these! More importantly, they are necessary for making video accessible. Display Unicode characters like,, Use a wide variety of colours Different fonts, including proportionally spaced Precise positioning Begin at the left edge שלום Handle bidirectional text Or vertical, or Ruby Work nicely on the web Carry metadata

7 7 BROADCASTER INFRASTRUCTURE

8 8 BROADCASTER INFRASTRUCTURE BBC SUBTITLE WORKFLOWS CURRENT (2018) NUFOR (1) Processing (minor) Conversion (major) Subtitle inserter Prepared workflow Live workflow Shortform (iplayer exclusive, clips) Subtitler (Red Bee) STL Playout Teletext (VANC) Broadcast Coding & Multiplexing DVB Bitmap & Teletext TV EBU-TT with embedded STL Teletext VANC (2) Digital archive File delivery receiving system EBU-TT with embedded STL BBC R&D Media Encode and Package services EBU-TT-D (live to VOD) TTML (3) BBC Standard Media Player STL Subtitler (BBC?) EBU-TT-D (clips etc) Internal Web production/ CMS tools EBU-TT-D 6 formats, 3 conversion points.

9 9 BROADCASTER INFRASTRUCTURE BBC SUBTITLE WORKFLOWS - VISION Processing (minor) Conversion (major) Subtitle inserter Prepared workflow Live workflow Shortform (iplayer exclusive, clips) Subtitler (Red Bee) EBU-TT (prepared) EBU-TT (live captured) File delivery receiving system EBU-TT Playout EBU-TT pt 3 Broadcast Coding & Multiplexing DVB Bitmap & Teletext & DVB TTML TV EBU-TT pt 3 Archive Search Digital archive EBU-TT Media Encode and Package services EBU-TT-D (VOD) EBU-TT-D in DASH (stream) BBC Standard Media Player, Freeview Play EBU-TT-D Subtitler (BBC?) EBU-TT-D Internal Web production/ CMS tools EBU-TT-D 2 file formats, 1 conversion point.

10 10 LONGER TERM IP EVERYWHERE? The broadcast industry seems to be heading strategically towards: IMF for mastering and archive IP streams (e.g. SMPTE 2110) for playout and live Everything is just an object. Subtitles were objects first! This means that we are generally heading towards a deembedded 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.

11 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 software and IP network based so we can choose the right deployment model.

12 12 ADOPTING NEW STANDARDS

13 13 ADOPTING NEW STANDARDS WHICH STANDARDS? There are a lot of subtitle formats (not so many standards)! BBC prefers: Open standards freely available, developed in an open process As few standards as possible, or minimal transcode requirements Technology that fits business processes The standard needs to support: Everything Teletext can do, and the things it can t do Prepared subtitles Live subtitles Hard of hearing and translation Broadcast and web distribution and playback Support for the whole broadcast workflow, i.e. the right timing and supporting metadata. 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 profiles that meet our needs, and the needs of our audience. TTML profiles include EBU-TT, EBU-TT Live, SMPTE-TT, IMSC, ARIB-TT etc. Industry seems to be converging on TTML globally: IMSC in MPEG CMAF and IMF (even on ios!) EBU-TT-D and IMSC in DVB TTML EBU-TT-D in HbbTV 2.0, Freeview Play IMSC in ATSC 3.0

14 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 workflows, but another where questions are often 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.

15 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

16 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 offer new cheaper ways to implement broadcast workflows. 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. Often there is a chicken-and-egg problem! Result: likely to take years rather than months.

17 17 CONCLUSIONS

18 18 CONCLUSIONS WE RE ON THE WAY We know the engineering problems we want to solve. We know how we want to solve them. The technical standards are mostly in place. There is momentum towards convergence in the industry. We have more work to do specifically in automated playout and in encoders and packagers. Calls to action: if you re buying new kit, consider moving to new standards. If you re selling kit, put this on your development roadmap. If you re representing the audience, let your broadcasters (and maybe even regulator) know what you would like to see and what editorial proposition you would like.

19 D + E THANK YOU! NIGEL MEGITT nigel.megitt@bbc.co.uk

20 20 ONWARD MORE INFORMATION BBC Subtitle Guidelines: BBC Academy Guide How to create subtitles : BBC R&D publications on accessibility:

4. Producing and delivering access services the options

Tutorial on Audio Visual Media Accessibility (New Delhi, India, 14-15 March 2012) 4. Producing and delivering access services the options Dr Takebumi ITAGAKI ECE, School of Engineering & Design, Brunel