Chapter 6 Functions Superimposed Over TV Signals
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6.3 Teletext
6.3.1 Description and specifications
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What is “Teletext”?
Teletext is the name of a system used to send still picture program data of text and graphics after multiplexing it in the vertical
sync blanking interval of the TV signals. Programs broadcast in Teletext include subtitled broadcasts, news broadcasts, weather
forecasts and stock market information. Teletext has achieved a high penetration rate in various countries in Europe and
Southeast Asia where the 625/50i system is used.
With Teletext, a total of 40 characters × 25 lines can be contained on a page (per screen), and between 100 and 899 pages of
information can be displayed.
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Teletext specifications
Teletext supports the following TV signals.
Teletext is superimposed onto the composite signals and Y/C signals.
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PAL (but not PAL-Nc)
The vertical sync blanking interval (VBI) and Teletext waveforms are shown below.
The Teletext data can be output in lines 8 to 22 (first field) and lines 321 to 335 (second filed) in the vertical sync blanking interval
of the PAL signals.
A total of 45 bytes consisting of the Clock Run-In, Framing Code and data bytes (42 bytes) are superimposed in one line.
VBI waveforms
Clock Run-In
66IRE
0I
RE
1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 1 1 0 0 1 0 0
Framing
Code
2byte
1byte
45byte
Teletext
Summary of Contents for VG-884
Page 1: ...Portable Video Signal Generator VG 884 Instruction Manual Ver 1 00 ...
Page 2: ......
Page 3: ...Portable Video Signal Generator VG 884 Instruction Manual 2012 7 Ver 1 00 ASTRODESIGN Inc ...
Page 4: ......
Page 16: ...xii ...
Page 26: ...10 ...
Page 58: ...42 ...
Page 93: ...Chapter 4 Selecting and Editing Pattern Data 77 ...
Page 96: ...80 ...
Page 99: ...Chapter 4 Selecting and Editing Pattern Data 83 12BIT 0 4095 ...
Page 108: ...92 0 1 2 3 4 5 6 ...
Page 147: ...Chapter 5 Output Settings 131 MENU Display returns to the initial screen ...
Page 161: ...Chapter 5 Output Settings 145 3 4Kx2K 24Hz SMPTE ...
Page 164: ...148 9 16 9 4 3 center ...
Page 166: ...150 3 AdobeYCC601 4 AdobeRGB ...
Page 170: ...154 6 176 4kHz 7 192kHz ...
Page 177: ...Chapter 5 Output Settings 161 2 12bit ...
Page 183: ...Chapter 5 Output Settings 167 1 Advance Cipher Enhanced Link Verification is not supported ...
Page 206: ...190 9 16 9 4 3 center ...
Page 208: ...192 3 AdobeYCC601 4 AdobeRGB ...
Page 211: ...Chapter 5 Output Settings 195 7 192kHz ...
Page 228: ...212 ...
Page 246: ...230 Teletext waveforms ...
Page 270: ...254 ...
Page 290: ...274 Select EXECUTE using or INC DEC and then press SET to erase the user characters ...
Page 304: ...288 ...
Page 351: ...Carter10 Internal data 335 ...
Page 354: ...338 F0H letters me 1 F1H letters me 2 VESA specifications ...
Page 355: ...Carter10 Internal data 339 ...
Page 356: ...340 F2H Chinese character AI F3H Chinese character BI ...
Page 357: ...Carter10 Internal data 341 ...
Page 358: ...342 F4H Chinese character TAKA F5H Chinese character KIRI ...
Page 359: ...Carter10 Internal data 343 ...
Page 360: ...344 F6H Chinese character KEN F7H Burst ...
Page 361: ...Carter10 Internal data 345 ...
Page 362: ...346 10 4 Character pattern data 5 7 character pattern table 1 of 2 ...
Page 363: ...Carter10 Internal data 347 ...
Page 364: ...348 5 7 character pattern table 2 of 2 ...
Page 365: ...Carter10 Internal data 349 7 9 character pattern table 1 of 2 ...
Page 366: ...350 ...
Page 368: ...352 ...
Page 369: ...Carter10 Internal data 353 16 16 character pattern table 1 of 4 ...
Page 370: ...354 ...
Page 371: ...Carter10 Internal data 355 16 16 character pattern table 2 of 4 ...
Page 372: ...356 ...
Page 373: ...Carter10 Internal data 357 16 16 character pattern table 3 of 4 ...
Page 374: ...358 ...
Page 375: ...Carter10 Internal data 359 16 16 character pattern table 4 of 4 ...
Page 376: ...360 ...
Page 379: ...Chapter10 Internal data 363 Table of TV standard signal timing waveforms 1 of 3 ...
Page 380: ...364 Table of TV standard signal timing waveforms 2 of 3 ...
Page 381: ...Chapter10 Internal data 365 Table of TV standard signal timing waveforms 3 of 3 ...
Page 382: ...366 ...
Page 384: ...368 ...