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"Teletext" in this context is a signalling protocol for transmitting text content over PAL TV, for decoding by an appropriate receiver. The BBC's service was b
by Symbiote 3y ago
"Teletext" in this context is a signalling protocol for transmitting text content over PAL TV, for decoding by an appropriate receiver.
The BBC's service was branded "Ceefax", ITV and Channel 4 branded theirs "Teletext".
The current 'red button' service is a completely different protocol running on DVB (Digital Video Broadcast, i.e. digital TV). Text packets are added to the MPEG-2 stream.
- PodgieTar 3y agoAh, my apologies then. My confusion was that I didn't think there was a difference between the current mechanism and the old one.
- phh 3y agoFWIW you can still get Teletext over MPEG TS (DVB or IPTV), it's just already de-modulated, but even error correction bits are still there (and are useless). In France most IPTV operators still use teletext for live subtitling because it eats much less bandwidth than dvbsub
- Doctor_Fegg 3y agoThe ITV/C4 service was originally Oracle; this was later replaced by “Teletext Ltd”. https://en.m.wikipedia.org/wiki/ORACLE_(teletext) https://en.m.wikipedia.org/wiki/ORACLE_(teletext)