Behind the Scenes of Teletext: Subtitles, Data Broadcasting, and More

Former BBC engineer Peter Wietzel joins Russell Trafford-Jones in this episode of Broadcast Focus as they delve into the intricacies of Teletext covering how subtitles work, why the BBC tansmission actually used two simultaneous subtitle transitions, and the many uses of carrying arbitrary data over Teletex were were the hidden heros! Peter finishes by talking about how the implementation was one of the first cross industry examples of collaboration in creating standards and talks about MHEG which replaced Teletext. Whether you're a technical enthusiast or just curious about broadcasting history, this should be good!

00:00 Welcome & Intro

02:30 Understanding Subtitles in Teletext

04:11 Technical Details of Subtitles Transmission

10:42 Subtitle Demo

11:10 Inserting Live and Recorded Subtitles

15:57 Dealing with Lack of Subtitles & Policing

18:35 Using 'Subtitles' to Help Deal with AFD/VI/Aspect Ratio

19:34 A Second Simultaneous Subtitle System for Internal Use

21:27 Inserting Subtitles in the BBC Regions

22:50 Teletext in SDI - SDI Bridge

25:25 Second Generation SDI Bridge

27:40 Quick look at Presfax

29:06 Databroadcasting – Sending Generic Data

31:40 Uses of Databroadcaster

34:00 Dairy Farming

36:00 Carrying audio over Teletext

40:40 Presfax Details

44:36 Controling Overlay Insertion at Transmitters

46:11 Ceefax In Vision

49:25 Teletext Standards

50:58 Collaboration and Standardisation in the 90s

54:58 Technical Enhancements and Memory Management

01:02:56 The Rise of Electronic Programme Guides

01:08:19 PDC - Recording Programmes

01:20:09 The Transition to Digital Broadcasting

01:23:00 The End of Teletext and Its Legacy

01:28:00 Reflections and Closing Remarks

With thanks to https://www.nathanmediaservices.co.uk/ceefax/ for the demos and by extension ZXGuesser