Chapter 3 Analog Output Settings (ANALOG OUTPUT)
17
● Teletext
■ What is teletext?
Teletext is the name of a system that multiplexes and sends text and graphic still image program data during the TV signal
vertical blanking interval. Program content includes subtitle broadcasts, news broadcasts, weather forecasts, stock information,
etc., with many countries adopting the European and Southeast Asian 625/50i system.
In teletext, 40 characters x 25 lines can be displayed per page (1 screen), from 100 to 899 pages.
■ Teletext specifications
Teletext is compatible with the following TV signals.
Teletext is superimposed on composite signals, and Y/C signals.
・ PAL (Does not include PAL-60, PAL-N, PAL-Nc)
The vertical blanking interval (VBI) and teletext waveform are shown below.
Teletext data is output in PAL signal vertical blanking interval lines 8 to 22 (1st field) and lines 321 to 335 (2nd field).
Additionally, data superimposed on line 1 is 45 bytes of Clock Run-IN and Framing Code data (42 bytes).
VBI waveform
Teletext waveform
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