EN 61866:1997

Audiovisual systems - Interactive text transmission system (ITTS)

Interactive text transmission system (ITTS) provides the mechanism for encoding sound associated data on prerecorded media and for the transport of such data across equipment interfaces. Defines the higher layers of ITTS, i.e. those system characteristics which are independent of the recording or interconnection medium.

Audiovisuelle Systeme - Interaktives Textübertragungssystem (ITTS)

Systèmes audiovisuels - Système de transmission de textes interactifs (ITTS)

Système de transmission de textes interactifs (ITTS) fournit le mécanisme permettant de coder des données audio sur des supports préenregistrés et de transporter ces données sur les interfaces appartenant à ces matériels. Définit les couches supérieures de l'ITTS, c'est-à-dire les caractéristiques du système qui sont indépendantes du moyen d'enregistrement ou d'interconnexion.

Audiovisual systems - Interactive text transmission system (ITTS) (IEC 61866:1997)

General Information

• Status: Published
• Publication Date: 21-Oct-1997
• Withdrawal Date: 30-Jun-1998
• ICS: 33.160.99 - Other audio, video and audiovisual equipment
• Technical Committee: CLC/TC 100X - Audio, video and multimedia systems and equipment and related sub-systems
• Drafting Committee: IEC/TC 100 - IEC_TC_100
• Parallel Committee: IEC/TC 100 - IEC_TC_100
• Current Stage: 6060 - Document made available - Publishing
• Start Date: 22-Oct-1997
• Completion Date: 22-Oct-1997
• Ref Project: SIST EN 61866:1999 - Audiovisual systems - Interactive text transmission system (ITTS)

Standards Content (Sample)

SLOVENSKI STANDARD
01-april-1999
Audiovisual systems - Interactive text transmission system (ITTS) (IEC
61866:1997)
Audiovisual systems - Interactive text transmission system (ITTS)
Audiovisuelle Systeme - Interaktives Textübertragungssystem (ITTS)
Systèmes audiovisuels - Système de transmission de textes interactifs (ITTS)
Ta slovenski standard je istoveten z: EN 61866:1997
ICS:
33.160.99 Druga avdio, video in Other audio, video and
avdiovizuelna oprema audiovisual equipment
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

NORME
CEI
INTERNATIONALE
IEC
INTERNATIONAL
Première édition
STANDARD
First edition
1997-08
Systèmes audiovisuels –
Système de transmission de textes interactifs (ITTS)
Audiovisual systems –
Interactive text transmission system (ITTS)
 IEC 1997 Droits de reproduction réservés  Copyright - all rights reserved
Aucune partie de cette publication ne peut être reproduite ni No part of this publication may be reproduced or utilized in
utilisée sous quelque forme que ce soit et par aucun any form or by any means, electronic or mechanical,
procédé, électronique ou mécanique, y compris la photo- including photocopying and microfilm, without permission in
copie et les microfilms, sans l'accord écrit de l'éditeur. writing from the publisher.
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Pour prix, voir catalogue en vigueur
For price, see current catalogue

61866 © IEC:1997 – 3 –
CONTENTS
Page
FOREWORD . 7
INTRODUCTION. 9
Clause
1 General. 11
1.1 Scope. 11
1.2 Definitions and abbreviations . 11
1.2.1 Definitions.11
1.2.2 Abbreviations. 11
1.3 Presentation conventions. 13
2 ITTS packet structure. 13
2.1 Introductory remark. 13
2.2 ITTS packet format . 13
2.3 Packet-header field descriptions, bytes 0 – 7 . 19
2.3.1 Packet-header byte 0: language number and application item. 19
2.3.2 Packet-header byte 1-2: packet index . 21
2.3.3 Packet-header byte 3-4. 23
2.3.4 Packet-header byte 5. 29
2.3.5 Packet-header byte 6: function controls. 33
2.3.6 Packet-header byte 7: character set control . 39
2.4 Data field description, bytes 8-47. 41
2.4.1 GRAPHICS packet . 41
2.4.2 DATA packet. 45
3 ITTS data presentation. 49
3.1 Character repertoire. 49
3.2 Serial textline attributes and character controls . 61
3.2.1 Serial text line attributes. 61
3.2.2 Decoder and character-display alternatives. 63
3.3 1-line display functions. 65
3.3.1 Validation of 12 characters from 40-character text. 69
3.3.2 Character validation. 69
3.4 HORIZONTAL SCROLL function for 12-character displays . 69
3.5 CLEAR SCREEN
..................................................................................................................... 71
3.6 Colours. 71
3.6.1 Default colours. 73
3.6.2 Highlighting related colour constraints. 73
3.7 Menus. 73
3.7.1 Vertical and horizontal menus. 75
3.7.2 Function control via commands. 77
3.7.3 Interactive commands. 77
3.7.4 IC command table. 77
3.8 Dynamically redefinable character (DRC) packet . 89
3.8.1 DRC pattern transmission format, single font mode. 89
3.8.2 DRC pattern transmission format, double size font mode . 91
3.9 Data integrity. 91

61866 © IEC:1997 – 5 –
Page
Tables
1 Latin-based alphanumeric character set. 51
2 Extended Latin-based alphanumeric character set . 53
3 Mosaic and lined graphics font set . 55
4 Japanese font table 1 . 57
5 Japanese font table 2 . 59
6 Conversion from ITTS character codes to JIS font numbers . 61
7 Serial textline attributes. 63
8 Foreground colour serial textline attributes. 65
9 Background colour serial textline attributes. 65
10 1-line display controls . 67
11 Colour look up table. 73
Figures
1 TEXT packet content .15
2 RUNTIME MENU
packet content. 15
3 GRAPHICS TEXT packet content. 17
4 GRAPHICS RUNTIME MENU packet content. 17
5 DATA packet content. 19
C.1 Character set selection within a text line – Example of mixed graphics and
alphanumeric line. 105
C.2 Character set selection within a text line – Example of mixed alphanumeric, Kanji
and Katakana line . 107
C.3 Language selection by indexing a maximum of seven languages out of a total
of 256 possible languages . 107
Annexes
A (informative) Application examples for 2-line coding . 93
B (informative) Sample outline for 12-character validation . 99
C (informative) Language support and character sets . 103
D (informative) Bibliography. 109

61866 © IEC:1997 – 7 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
_________
AUDIOVISUAL SYSTEMS –
INTERACTIVE TEXT TRANSMISSION SYSTEM (ITTS)
FOREWORD
1) The IEC (International Electrotechnical Commission) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of the IEC is to promote
international cooperation on all questions concerning standardization in the electrical and electronic fields. To this
end and in addition to other activities, the IEC publishes International Standards. Their preparation is entrusted to
technical committees; any IEC National Committee interested in the subject dealt with may participate in this
preparatory work. International, governmental and non-governmental organizations liaising with the IEC also
participate in this preparation. The IEC collaborates closely with the International Organization for Standardization
(ISO) in accordance with conditions determined by agreement between the two organizations.
2) The formal decisions or agreements of the IEC on technical matters express, as nearly as possible, an
international consensus of opinion on the relevant subjects since each technical committee has representation from
all interested National Committees.
3) The documents produced have the form of recommendations for international use and are published in the form
of standards, technical reports or guides and they are accepted by the National Committees in that sense.
4) In order to promote international unification, IEC National Committees undertake to apply IEC International
Standards transparently to the maximum extent possible in their national and regional standards. Any divergence
between the IEC Standard and the corresponding national or regional standard shall be clearly indicated in the
latter.
5) The IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with one of its standards.
6) Attention is drawn to the possibility that some of the elements of this International Standard may be the subject
of patent rights. The IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 61866 has been prepared by subcommittee 100C: Equipment and
systems in the field of audio, video and audiovisual engineering, of IEC technical committee 100:
Audio, video and multimedia systems and equipment.
The text of this standard is based on the following documents:
FDIS Report on voting
100C/114/FDIS 100C/132/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
Annexes A, B, C and D are for information only.

61866 © IEC:1997 – 9 –
INTRODUCTION
Distribution and reproduction of digital sound recordings can be accompanied by text
associated with the sound track. Such data can be, for instance, album and track titles, lyrics
or information about artists and performers.
ITTS covers application requirements for pre-recorded media, digital broadcasting and remote
controls. Several display options are supported for information readout: 21-, 2- and 1-line
displays of 40 characters each, as well as a 12-character display window.
The user interface consists of displayed text and provision for direct access to information by
means of related function control keys or a cursor positioned over a menu item and a SELECT
function key.
Various character sets can be used in the system. Up to 40 (horizontal) × 21 (vertical)
alphanumerical characters can be presented on a screen. For other fonts, like Kanji, the
number of fonts that can be presented on a screen depends on the font size which is defined
together with the font table.
ITTS uses the Latin-based alphanumeric character set based on ISO 8859-1 and the repertoire
described in EBU Tech. 3232. Further, a font set containing graphical elements and font sets
providing Japanese fonts are presently defined.
NOTE – User-defined 12 horizontal × 10 vertical pixel graphics may be included as well.
Information may be presented in monochrome or in up to 15 colours. These colours are
defined in a colour look up table (CLUT) and may be redefined from a palette of 4 096 colours.
Information can be accessed without delay if the ITTS decoder provides a cache memory in
which the data from the medium is captured before it is needed for display. An index is applied
to each transmission packet to serve this and several other functions.

61866 © IEC:1997 – 11 –
AUDIOVISUAL SYSTEMS –
INTERACTIVE TEXT TRANSMISSION SYSTEM (ITTS)
1 General
1.1 Scope
The interactive text transmission system (ITTS) provides the mechanism for encoding sound
associated data on prerecorded media and for the transport of such data across equipment
interfaces. This International Standard defines the higher layers of ITTS, i.e. those system
characteristics which are independent of the recording or interconnection medium.
1.2 Definitions and abbreviations
1.2.1 Definitions
For the purpose of this International Standard the following definitions apply:
1.2.1.1 ITTS: Interactive text transmission system
1.2.1.2 ITTS packet: A data structure comprising header information plus either coded
text and graphics or control and presentation commands. ITTS packets have a fixed length
of 48 bytes.
1.2.2 Abbreviations
The following abbreviations are introduced in the main text:
AI: application item;
IC: interactive command;
ICP: interactive command present;
TCI: text continuity index;
ICI: instruction continuity index;
CDS: category data start;
CDE: category data end;
CI: command index;
PI: packet index;
MMC: main message channel;
SMC: submessage channel;
CLUT: colour look up table;
DRCS: dynamic redefinable character set.

61866 © IEC:1997 – 13 –
1.3 Presentation conventions
The following conventions are used in this standard to specify binary and hexadecimal
numbers.
Where a hexadecimal code or binary code occurs in tables
– the hexadecimal code is followed by a lower case h; for example, the hexadecimal
presentation for a byte containing all binary values 1 is written as FFh,
– the binary code is represented by a string of 1s and 0s. A string of 8 bits, comprised in
one byte, is written in two groups of 4 bits; for example the binary presentation of a byte
containing the binary equivalent of decimal 255 is written as 1111 1111.
Where a hexadecimal code or binary code occurs in running text, the code values as described
above are enclosed in double quotes.
2 ITTS packet structure
2.1 Introductory remark
Text information arranged in packets according to the ITTS format can be carried by a
subchannel along with audio data. ITTS packets have a length of 48 bytes: an 8 byte header
and a 40 byte TEXT or DATA string.
Details on how ITTS packets are carried in the subchannel of transmission media is given in
the following standards:
1)
– amendment 2 to IEC 60908 ;
– amendment 2 to IEC 60958;
– ETS 300 401.
2.2 ITTS packet format
The 48 bytes of an ITTS packet are grouped into the
– packet-header field: bytes 0 – 7,
– data field: bytes 8 – 47.
The packet content differs according to the application item code in bits 3-0 of the first packet
byte. The following five packet types are defined:
– TEXT packet;
– RUNTIME MENU packet;
– GRAPHICS TEXT packet;
– GRAPHICS RUNTIME MENU packet;
– DATA packet.
________
1)
To be published.
61866 © IEC:1997 – 15 –
Figures 1 to 5 specify the content lay-out of the packet header for each of these packet types.
Bit  MSB LSB
7    .    6    .    5    .    4    .    3    .    2    .    1    .   0
Byte
LANGUAGE NUMBER APPLICATION ITEM
1 PACKET INDEX MSByte
2 PACKET INDEX LSByte
3 MAIN MESSAGE CHANNEL CODE
Packet
header
4 SUBMESSAGE CHANNEL CODE
5 21-LINE CODE
2-LINE CODE
6ICP
SCROLL ATTRIBUTE TCI CDS CDE
7 CHARACTER SETS
8 CHARACTER CODE 1
One
CHARACTER CODE 2 – 39
text line
47 CHARACTER CODE 40
Figure 1 –TEXT packet content
Bit  MSB LSB
7    .    6    .    5    .    4    .    3    .    2    .    1    .   0
Byte
LANGUAGE NUMBER APPLICATION ITEM
1 PACKET INDEX MSByte
2 PACKET INDEX LSByte
3 RUNTIME MENU SEGMENT NUMBER (BCD)
Packet
header
4 RUNTIME MENU SUBSEGMENT NUMBER (BCD)
5 21-LINE CODE
2-LINE CODE
6ICP
SCROLL ATTRIBUTE TCI CDS CDE
7 CHARACTER SETS
8 CHARACTER CODE 1
One
CHARACTER CODE 2 – 39
text line
47 CHARACTER CODE 40
Figure 2 – RUNTIME MENU packet content

61866 © IEC:1997 – 17 –
Bit  MSB LSB
7    .    6    .    5    .    4    .    3    .    2    .    1    .   0
Byte
LANGUAGE NUMBER APPLICATION ITEM
1 PACKET INDEX MSByte
2 PACKET INDEX MSByte
3 MAIN MESSAGE CHANNEL CODE
Packet
header
4 SUBMESSAGE CHANNEL CODE
5 21-LINE CODE
2-LINE CODE
6ICP
SCROLL ATTRIBUTE TCI CDS CDE
7MODE
HORIZONTAL POSITION
8 GRAPHICS PIXEL CODE 1
One
graphics
GRAPHICS PIXEL CODE 2 – 39
area
47 GRAPHICS PIXEL CODE 40
Figure 3 – GRAPHICS TEXT packet content
Bit  MSB LSB
7    .    6    .    5    .    4    .    3    .    2    .    1    .   0
Byte
LANGUAGE NUMBER APPLICATION ITEM
1 PACKET INDEX MSByte
2 PACKET INDEX LSByte
3 RUNTIME MENU SEGMENT NUMBER (BCD)
Packet
header
4 RUNTIME MENU SUBSEGMENT NUMBER (BCD)
5 21-LINE CODE
2-LINE CODE
6ICP
SCROLL ATTRIBUTE TCI CDS CDE
7MODE
HORIZONTAL POSITION
8 GRAPHICS PIXEL CODE 1
One
graphics
GRAPHICS PIXEL CODE 2 – 39
area
47 GRAPHICS PIXEL CODE 40
Figure 4 – GRAPHICS RUNTIME MENU packet content

61866 © IEC:1997 – 19 –
Bit  MSB LSB
7    .    6    .    5    .    4    .    3    .    2    .    1    .   0
Byte
LANGUAGE NUMBER APPLICATION ITEM
1 PACKET INDEX MSByte
2 PACKET INDEX LSByte
3 MAIN MESSAGE CHANNEL CODE
Packet
header
4 SUBMESSAGE CHANNEL CODE
5 RESERVED
DATA TYPE
RESERVED ICI CDS CDE
Reserved
8 DATA BYTE 1
Data
DATA BYTE 2 – 39
47 DATA BYTE 40
Figure 5 – DATA packet content
2.3 Packet-header field descriptions, bytes 0 – 7
2.3.1 Packet-header byte 0: language number and application item
Bit 7
0 Reserved for future use
1 Default (must be set to 1 to identify the packet format according to this standard)
Bit 6-4 = language number
000 Language-independent text or one language only
001 Main language, if various languages are recorded

* * * Additional languages

111 
NOTE – Text lines that are identical in all language versions need to be recorded only once if the given
language number is "000". It is recommended to apply additional languages in consecutive order.
If more than one language is applied, then the main language with code "001" shall be
specified by the content provider.

61866 © IEC:1997 – 21 –
Bit 3-0 = application item
0000 TEXT packet for 2-line and 21-line display
0001 RUNTIME MENU packet for 2-line and 21-line display
0010 GRAPHICS TEXT packet for 2-line and 21-line display
0011 GRAPHICS RUNTIME MENU packet
0111 DATA packet.
1000 TEXT packet, also for 1-line display
1001 RUNTIME MENU packet, also for 1-line display
1010 GRAPHICS TEXT packet, also for 1-line display
1011 GRAPHICS RUNTIME MENU packet, also for 1-line display
**** All other codes are reserved
Only one packet per message channel or RUNTIME menu segment shall be specified as "also
for 1-line display".
2.3.2 Packet-header byte 1-2: packet index
The main applications for the packet indices are
– to support cache memory management for ITTS program packets;
– to control text line order when loaded into the display memory;
– to specify packets, the content of which shall not be loaded into a cache memory but
displayed and/or executed immediately after passing the input filter stages of the decoder;
– to define the priority of a packet with respect to the cache memory size;
– to link DATA packet inherent commands with TEXT packet(s);
– to link DATA packets with horizontal menu text;
– to support a packet group validity check.
The packet index is carried in byte 1-2 of each packet. Rules related to the packet index are
as follows:
– a packet index other than "0000h" indicates at which cache memory address the packet
shall be stored;
– packets with index "0000h" shall not be loaded into the cache memory;
– textual contents of packets with index "0000h" shall be displayed immediately when
occurring at the output of the language and channel filter bank;
– commands (IC) with command index "0000h" in DATA packets with index "0000h" shall be
executed immediately;
– commands (IC) with command index "0000h" in DATA packets with index other than
"0000h" shall be executed when the corresponding channel becomes invoked. If an IC
inherent command index is equal to its packet index, then this IC can only be activated by
an IC 5 command; this means such commands are not activated when the corresponding
message channel becomes invoked;

61866 © IEC:1997 – 23 –
– the command index of an IC shall have the same value as the packet index of the text
packet to which it is linked;
– commands (IC) in a packet index sequence defined by a CDS and CDE pair shall be
executed in the ascending order of packet indices and packet inherent bytes;
– the packet index "0003h" is reserved for the first packet of the main menu packet
sequence of the submessage channel;
– packets with equal language, main and submessage channel specifier shall have
contiguous ascending packet index values.
NOTE – All data which belong to a selected language and main message channel may be loaded into a cache
memory irrespective of the user's submessage channel selection. Packets which cannot be stored in the cache
memory due to lack of memory capacity are retrieved as they appear in the transmission sequence of the
current category display constraint.
2.3.2.1 Reserved packet index "0001h"
The packet with index "0001h" is reserved for a DATA packet which contains access
instruction(s) for the most significant channel. Recommended applications are the super-main
menu or an access instruction for a submessage channel with application-specific presentation
preference. A super-main menu access instruction may replace any other contents which
already exist at the same location. Packet index "0001h" inherent instructions shall only be
active at decoder POWER-UP or insertion of a new program.
In program generation for prerecorded media, it is essential to take into account that ins-
truction(s) at packet index "0001h" may become lost during post-processing or in multiple main
message channel applications.
The default coding format for a packet index code "0001h" is the following:
Application item 0111
DATA
type 00010
Main message channel (MMC) 0000 0000
Submessage channel (SMC) 0000 0000
CDS 1
CDE 1
IC command indices 0000h
2.3.2.2 Reserved packet index "0002h" for default CLUT data
A packet with index "0002h" provides a colour look up table for all submessage channels of
the actual main message channel; this packet is transmitted in a DATA packet with DATA type
code "00001" (see 2.4.2.1).
2.3.3 Packet-header byte 3-4
TEXT GRAPHICS TEXT DATA
2.3.3.1 , and packet
The packet data stream may consist of up to 254 main message channels plus one reserved
for hardware function control; 255 submessage channels for each main message channel
are available. Only one main message channel is selected at a time. For pre-recorded media, the
main message channel is defined by code "xxx0 0001". Parallel channels in multiple-sector appli-
cations are uniquely accessible via dedicated coding of the three most significant bits of byte 3.

61866 © IEC:1997 – 25 –
One main message channel (MMC) code is defined as belonging to all main message
channels, and for each main message channel there is also a submessage channel (SMC)
code to identify packets that belong to all submessage channels:
– the channel "00h/00h" shall override any other pre-selection;
– the channel "MMC/00h" shall override any submessage channel pre-selection in the
selected main message channel;
– the channel "00h/SMC" shall override any main message channel pre-selection.
Decoder initial settings after power-up for language, main message channel and submessage
channel are:
Language 000 and 001
Main message channel 0000 0001 (pre-recorded media)
Submessage channel 1111 1111 (main menu of this MMC)
The decoder first filters all data for packets with valid language and main message channel
codes as selected.
The submessage channel filter follows the language and main message channel filter stages.
The submessage channel filter output delivers the packets for display, command execution and
system control as actually selected.
Packets with index "0000h" that pass the submessage channel filter are available for
immediate processing and/or for display. Those that do not pass this filter are lost. Packets
with index greater than "0000h" are loaded into a cache memory (if available); those that are
out of the range of the cache memory are lost.
The packets belonging to one submessage channel shall be delimited by dedicated category
data start/end flags (CDS/CDE) (see 2.3.5.1).
Byte 3 = main message channel code
For prerecorded media the main message channel code shall be as follows:
000 This packet is recorded on a 2-sector tape and also on 4-sector tape, for those
packets which belong to channels I and II
010 This packet is recorded on a 4-sector tape for those packets which belong to channel I
only
100 This packet is recorded on a 4-sector tape for those packets which belong to
channel II only
00001 End user information
00010 Disc jockey information
Byte 4 = submessage channel code
7654 3210
0000 0000 Submessage channel independent packet
0000 0001

**** **** Application specific submessage channel 1-253


0000 1101
0000 1110 Language MENU packet
1111 1111 Main MENU packet
61866 © IEC:1997 – 27 –
Reserved submessage channel codes for prerecorded media shall be as follows:
0000 0001 VOLUME title plus related information
0000 0010 RUNTIME MENU related TEXT packet
0000 0011 Actual RUNTIME MENU segment-related names and credits
0000 0100

**** **** Major submessage channels


0000 1000
0000 1001 Lyrics, may be synchronized
0000 1010

**** **** Supplementary submessage channels


1001 1111
1010 0000

**** **** Reserved


1111 1011
1111 1101 Reserved (for identification of recording equipment on consumer-recorded
media)
1111 1110 Language MENU
1111 1111 Main channel MENU
2.3.3.2 RUNTIME MENU and GRAPHICS RUNTIME MENU packet
RUNTIME MENU
Byte 3 = segment number 0-99 (BCD) or medium specific lead-in/out area code
Byte 4 = RUNTIME MENU sub-segment number 0-99 (BCD) or medium specific lead-in/out
area code
No interactive commands (ICs) shall be appended to packets with application item code
"0001", "0011", "1001" or "1011".
NOTE – The RUNTIME MENU segment specifier in bytes 3 and 4 of RUNTIME MENU packets (i.e. application item
code "0001", "0011", "1001" or "1011") may also serve for a GOTO_a_RUNTIME_MENU_segment hardware control
function. This makes the transmission of separate commands superfluous by maintaining the RUNTIME MENU
segment inherent SELECT and GOTO functions.
The decoder may invoke a select function for the RUNTIME MENU segment specified by the bytes 3 and 4 if the
received packet is coded with packet index "0000h".
In case an application contains packets other than RUNTIME MENU packets within the RUNTIME
MENU packet sequence, then these packets shall be coded as follows:
– packet byte 3 XXX0 0001 (pre-recorded media);
– packet byte 4 0000 0010 (RUNTIME MENU related TEXT packet).

61866 © IEC:1997 – 29 –
2.3.4 Packet-header byte 5
2.3.4.1 TEXT, RUNTIME MENU, GRAPHICS TEXT and GRAPHICS RUNTIME MENU packet
Bit 7-3 21-line code
00000 Not displayed on the 21-line display

***** Line number 1-21



***** Reserved


11100 Scroll-in from the bottom of the display, while the whole displayed text scrolls up
11101 Scroll-in from the top of display, while the whole displayed text scrolls down

***** Reserved


The 21-line code specifies a static position for channel header and footer text defined by the
scroll attributes "110" and "111" in the first TEXT packets of a submessage channel.
TEXT
packets with static header or footer text shall lead corresponding scrollable text in the
ascending order of packet indices (see 2.3.5.1, scroll attributes).
The area on the display in between the last header and first footer textline forms a display
window for scrollable text.
The 21-line code specifies a relative position to the actual scroll window area of a display,
separately for each non-static text group. These text groups are defined by a scroll attribute
applied to the first of TEXT packets forming a text section.
In a first TEXT packet of a text section or paragraph, a relative 21-line code "00001" indicates
that the section shall be displayed directly under preceding text or at the top of the
scroll window; a relative 21-line code "00010" indicates that one blank line shall be left in
between, etc.
Static and relative 21-line coding shall comply with the option to use fonts of double height or
size in a single textline, so that the decoder occupies the contiguous next display line number
in ascending order (top to bottom). A textline comprising double height fonts shall not be coded
for the display line number 21 as it cannot be displayed.

61866 © IEC:1997 – 31 –
Bit 2-0 2-line code
000 Not shown on the 2-line display
001 TOP line; the textline is fixed on the upper display line. A multiple of TOP line codes
"001" shall not be applied if both TOP and BOTTOM codes are used simultaneously
010 BOTTOM line; the textline is fixed on the lower line of the display. A multiple of BOTTOM
line codes "010" shall not be applied if both TOP and BOTTOM codes are used
simultaneously
011 Reserved
100 Reserved
101 ENTRY line. This textline is displayed when the corresponding submessage channel is
activated and no SCROLL function has been activated; in this function, the 2-line
display code "101" shall delimit the decoder search for subsequent TOP or BOTTOM line
codes
110 Reserved
111 FILL line. These textlines fill free lines on the display
Functional requirements for 2-line display decoding
A decoder shall scan actual textline packet indices in ascending order. If submessage channel
text is recorded in a logical order, then the result is the same as with textlines being scanned in
the TOP DOWN direction.
A decoder searches through the list of text packets (downwards, starting at the packet with
CDS = "1", towards the packet with CDE = "1") of the actual language and submessage
channel.
If the decoder finds an ENTRY line, and
a) a TOP line is found (but no BOTTOM line is found) before the ENTRY line, then the ENTRY
line is shown on the lower line of the display;
b) a BOTTOM line is found (but no TOP line is found) before the ENTRY line, then the ENTRY
line is shown on the upper line of the display and the (last found) BOTTOM line is shown on
the lower line of the display;
c) no TOP or BOTTOM line is found before the ENTRY line, then the ENTRY line is shown in the
upper line of the display and the lower line of the display shows the next FILL line in the list,
unless a TOP or BOTTOM line is encountered before the next FILL line; in that case the lower
display line remains blank because that TOP or BOTTOM line is regarded as the start of a
new section;
d) both a TOP line and a BOTTOM line are found before the ENTRY line, then the (last found)
TOP line is shown on the upper line of the display and the (last found) BOTTOM line is shown
in the lower line of the display; in that case the ENTRY
line is not shown on a 2-line display.
If no ENTRY line is found, but at least one FILL line is found in the list, then the first FILL line of
the list is regarded as entry point and the same routine is used to fill the display.
If no ENTRY line and no FILL line is found in the list, and
a) a TOP line is found (but no BOTTOM line is found) in the list, then the (last found) TOP line
is shown in the upper line of the display; the lower display line remains blank;

61866 © IEC:1997 – 33 –
b) a BOTTOM line is found (but no TOP line is found) in the list, then the (last found) BOTTOM
line is shown in the lower line of the display; the upper display line remains blank;
c) no TOP or BOTTOM line is found in the list, then both display lines remain blank;
d) both a TOP and BOTTOM line are found in the list, then the (last found) TOP line is shown in
the upper line of the display and the (last found) BOTTOM line is shown in the lower line of
the display.
If no ENTRY or FILL line(s) are present, then no scrolling is possible; this applies as well to
RUNTIME menu segments.
When the decoder receives a scroll-up or scroll-down command, then the previous or next line
with FILL or ENTRY code is taken as the entry point.
When a submessage channel is selected and neither a TOP nor a BOTTOM line is to be shown
for a group of corresponding text, then the first TEXT packet shall be displayed on the upper
free line of the display.
For the RUNTIME MENU readout via 2-line display, the default scan start location shall be the first
packet of an actual RUNTIME MENU segment. If the decoder is not capable to start the validation
of text for display at RUNTIME MENU segment or MENU independent list items it will display the
last independent TOP or BOTTOM item.
For further clarification, examples for 2-line coding are provided in annex A.
2.3.4.2 DATA
packet
Bit 7-5 = reserved
Bit 4-0 = DATA type of the packet bytes 8-47
00001 Packet contains CLUT colour data
00010 Packet with five interactive commands (ICs)
00011 Packet with commands which correspond to horizontal type menu text or 'hotspot'
areas respectively
00100 DRC packet
***** All other codes are reserved
2.3.5 Packet-header byte 6: function controls
2.3.5.1 TEXT RUNTIME MENU GRAPHICS TEXT GRAPHICS RUNTIME MENU
, , and packet
Bit 7 = interactive command present (ICP)
0 No interactive command to be linked to this packet
1 Program contains corresponding interactive command
This bit is set to "1" when a command is linked to the text line. This bit shall be set to "0" in
RUNTIME MENU and GRAPHICS RUNTIME MENU packets.

61866 © IEC:1997 – 35 –
Bit 6-4 = scroll attribute
000 This line is part of a group that forms a text section
001 This code marks the first line of a new text section that shall be kept together during a
manual scroll function. Several text sections may fill the display at once. In case the
number of textlines of one contiguous text section exceeds the actual scroll-window
size, then the manual scroll function starts display of text from top to bottom until the
display is filled
010 First line of the first text section of a new paragraph, which means that this packet and
corresponding text sections shall be scrolled up to the top of the display area or scroll
window respectively. Only one paragraph header text shall be shown at once
110 Static channel header textline, cannot be scrolled
111 Static channel footer textline, cannot be scrolled
Static channel header or footer textlines shall be overwritten only by TEXT packets, the index of
which is "0000h".
The area on display between the last line marked by code "110" and/or the first line marked by
code "111" forms a window for scrollable TEXT packets (seen from display top to bottom).
No more than 21 lines with codes "110" and/or "111" are allowed in a channel text.
NOTE – A decoder may either start scrolling text when the cursor has reached the end of the display area, or
allow some forthcoming textlines to be visible.
Bit 3-2 = text continuity index (TCI)
00 The text of the related packet remains the same on the entire program. This signals to
the decoder that it need not erase the text of that packet as long as the ITTS source is
available


11) Cyclic changing text continuity indices applied to packets which relate only to a

program segment e.g. a new track; the packets related to a new track shall have
a different text continuity index
The TCI of packets which are not coded as "00" and belong to the same submessage channel
program section shall all be identical except when the packet index of a packet is "0000h". In
that case the TCI is coded as "00". The decoder regards this as identical to the TCI of other
packets in the same submessage channel.
A decoder shall use a change of the text continuity index to clear the actual display content and
re-invoke the last function as activated by the user.
Bit 1-0 = category data start and category data and (CDS and CDE)
The CDS is used to synchronize the start of a series of packets carrying information that
should be retrieved as a specified group of information. The CDS bit is set on the first packet
and the CDE bit is set on the last packet of a series of packets belonging to the same
language, channel and/or group of packets to be retrieved and shown as a contiguous unit.

61866 © IEC:1997 – 37 –
CDS and CDE shall both be set in packets whose content is specified for immediate display.
When changing from one main message channel code to another (but not code "FFh", which
applies to a separate cache memory or dedicated ROM), the submessage channel data in the
cache memory are cleared with the exception of the packet index "01h" content. The decoder
may not validate newly retrieved channel data for display until all corresponding new packets,
including the ones with active CDS and CDE flag have been received. This prevents possible
display of mixed old and new data when loaded from the cache memory.
CDS/CDE related functions may be overruled by ICs which specify start/end packets by other
means or by hardware without sufficient cache memory.
Category data start/end coding scheme:
CDS
0 Not a first packet of a category
1 First of packets comprising a category
CDE
0 Not a last packet of a category
1 Last of packets comprising a category
2.3.5.2 DATA packet
Bit 7-4 = reserved
Bit 3-2 = instruction continuity index (ICI)
00 The last invoked function remains the same for the entire program. This signals to the
decoder that it need not change the last invoked function as long as the program
source is available



11 Cyclic changing instruction continuity indices for packets of a time code related next
program segment of the same category
The ICI of packets which are not coded as "00" and belong to the same submessage channel
program section shall all be identical except when the packet index of a packet equals "0000h".
In that case the ICI is coded as "00": the decoder then regards this as identical to the ICI of
other packets in the same submessage channel.
A decoder shall use a change of the instruction continuity index to re-invoke the last function or
command(s) activated by the user.

61866 © IEC:1997 – 39 –
2.3.6 Packet-header byte 7: character set control
2.3.6.1 TEXT and RUNTIME MENU packet
Bit 7-2 = character set control
765432 Serial attribute GS0-related character set (default) Serial attribute GS3-related
character set
000000 ALPHANUMERIC character set, 40 characters per Extended ALPHANUMERIC character set
text line
000100 ALPHANUMERIC character set
GRAPHIC font set, 40 characters per text line
ALPHANUMERIC
001000 Dynamic redefinable character set (DRCS), character set
40 characters per text line
001100 Double size dynamic redefinable character set, ALPHANUMERIC character set
20 characters per text line
110100 Reserved for Korean HANJA and Hangul font set, Reserved
based upon 20 characters/line
111000 Reserved for Chinese HANZI font set, Reserved
20 characters per text line
111100 Japanese font set: JIS X 0208-1990, Japanese font set: JIS X 0208-1990,
ALPHANUMERIC
(20 char/line) + (40 char/line) (20 char/line)+ KATAKANA (40 char/line)
All other codes are reserved.
The default character set, related to GS0, is effective from the start of a text line onwards, until
it is changed by means of another GS control within the line or until the end of the line.
Examples of character set invocation in relation to language support are provided in annex C.
When bits 7-2 = "000000", the default character set is specified as the Latin-based alpha-
numeric character set (see 3.1).
NOTE – IC 20 provides a function by which any character or serial attribute can be replaced by one from
another table. Multiple attributes specified for one and the same display line location apply in par
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