Digital Teletext

Overview

There are currently 3 different systems of Digital Text being broadcast on the DVB-T platform around the world:


VBI Text (Europe & Australia)

This is the familiar type of teletext that uses a page numbering system to select the page to view. Graphics are blocky, but it does have an advantage in that there is a huge amount of information available on these pages due to it being the system of choice for analogue TV viewers. DigiTV supports the FastText system (where available) with a large page caching buffer. Textual information can be extracted from any page and saved to a file (see Settings). See VBI Text Usage for how to access VBI Text from DigiTV in countries where it is transmitted.

MHEG-5 Text (UK Only)

MHEG-5 Teletext is quite a different animal to the teletext of old. Gone are the page numbers that you had to key in with your remote control, and gone are the blocky graphics that passed for pictures back in the '80s.

Nowadays, people expect a little more from their entertainment and digital teletext has gone a long way towards catching up with peoples' expectations.

Together with (the potential for) great graphics, Digital Teletext offers much more of an interactive feel to its pages with menu type selection methods. In the past, teletext pages were just that - pages of graphics that were simply displayed on the TV screen. Modern Digital Teletext is actually an amalgam of high-resolution images, movie clips and hypertext all controlled by a program that comes in over the airwaves.

Because the text is now controlled by a computer program rather than being displayed as a static page, it opens up a whole new world of interactive entertainment. We're just starting to see simple games being programmed by the teletext providers so that you can actually play the teletext page (although it'll be a little while before we see the likes of Doom III). In short, everything looks a lot nicer and you get picture-in-picture capability too.

The current language of Digital Text is MHEG-5 (Multimedia and Hypermedia information coding Experts Group) and DigiTV is designed to use UK profile 1.05. The standards information for profile 1.06 is now out and we will be updating to this profile soon - ready for when the new data is transmitted.


MHP Text (Europe & Australia)

This Digital Text format is just starting to appear in some countries across Europe, and test transmissions have taken place in Australia.

MHP stands for 'Media Home Platform' and it is intended to offer a fully interactive teletext system similar to MHEG-5.

DigiTV does not yet support MHP, but work is under way to provide full MHP functionality by the end of 2005/early 2006.