SIST ETS 300 294 E1:2003

• Abstract:

  Wide screen signalling specification for terrestrial TV services (PAL/SECAM, PALplus); wide screen letterbox (aspect ratio 16:9, film bit, subtitling)

• Status: Published
• Publication Date: 30-Nov-2003
• ICS: 33.160.25 - Television receivers
• ICS: 33.170 - Television and radio broadcasting
• Technical Committee: SS EIT - Technical Board for the electrotechnical, information technology and telecommunications fields
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 01-Dec-2003
• Due Date: 01-Dec-2003
• Completion Date: 01-Dec-2003
• Ref Project: ETSI ETS 300 294 ed.1 (1994-11) - Television systems; 625-line television Wide Screen Signalling (WSS)

SIST ETS 300 294 E1:2003 is the Slovenian adoption of ETS 300 294 Edition 1, published by SIST. It specifies Wide Screen Signalling (WSS) for 625-line PAL and SECAM television, including PALplus-related signalling for 16:9, letterbox, film and subtitle information. In practice, it tells broadcasters and receiver designers how to carry that information in the TV signal so receivers can choose the right display mode.

What does SIST ETS 300 294 E1:2003 specify?

SIST ETS 300 294 E1:2003 specifies the WSS information, the coding of that information, and how it is inserted into a 625-line television system. It is intended for cases where broadcasters need wide-screen signalling on 625-line PAL and SECAM services.

The document covers the transmitted signal and the meaning of the data bits. It also points to receiver display rules and subtitling behavior in Annex A.

Annex	What it covers
Annex A	Rules of operation for receiver display formats, subtitling, and default behavior when signalling is absent
Annex B	Recommendations for low pass pre-filtering and response time

The WSS message carries the aspect ratio range and picture position, subtitle position, camera or film mode, and reserved bits for later EDTV-related use.

What are the key requirements of SIST ETS 300 294 E1:2003?

SIST ETS 300 294 E1:2003 defines a fixed transmission format on line 23, with a 5 MHz clock, bi-phase coding, and a 14-bit message structure. These details matter because receiver decoding depends on exact timing, pulse shape, and bit meaning.

Line code and timing

WSS bits shall be transmitted as a data burst in the first part of line 23, starting 11.0 ± 0.25 µs from the falling horizontal sync edge. Line 23 is occupied in every frame. This gives receivers a known place to look for the signalling.

The clock frequency is 5 MHz, the pulse shape is approximately sine-squared, and the signal amplitude is 0.5 V ± 5% relative to a 700 mV maximum video signal. In practice, this defines how the WSS signal sits inside the video waveform.

Bi-phase coding is used, and one data bit period equals 6 clock periods. The preamble contains a run-in and a start code. This supports reliable bit detection and frame synchronization.

Data structure and meaning

The message has 14 bits in total, with 13 data bits and 1 odd parity bit. The odd parity bit applies to the first 3 data bits only. That gives simple error detection before the receiver acts on the display command.

Data group 1 carries the aspect ratio label, the letterbox format, and the picture position. The labels cover 4:3, 14:9, 16:9, and >16:9 cases, and the document links them to ranges of aspect ratio. This is the core information used for automatic picture formatting.

Data group 2 carries the film bit. A value of 1 indicates film mode, while 0 indicates camera mode. The standard also says field dominance shall follow EBU Recommendation R62 in film mode, which matters for picture processing.

Data group 2 also contains reserved bits b5, b6, and b7, which should be set to 0. Data group 4 is also reserved and should be set to 0. These bits are kept for later standardization, so they are not for private use.

Data group 3 carries subtitle signalling. One bit says whether subtitles are present within Teletext, and two bits indicate whether subtitles are in the active image area, out of the active image area, or not open subtitles. This helps receivers and services handle subtitles without hiding them in the wrong display mode.

Annex A says a 16:9 receiver should choose a display format based on the signalled aspect ratio, and the viewer should be able to override that choice. It also gives the expected handling of 4:3, 14:9, 16:9, and >16:9 pictures, which is important for consistent presentation.

What terms does SIST ETS 300 294 E1:2003 define?

• letterbox operation - A picture wider than 4:3 is transmitted inside a 4:3 format by adding black lines above and below the active picture.
• aspect ratio (a) - The relation between picture width and height used to classify the signalled format.
• clock frequency (Fs) - The signalling clock used for the WSS bit timing.
• falling sync edge (o) - The timing reference on the horizontal sync signal from which WSS position is measured.
• data bit period (Td) - The time used to send one WSS data bit.
• sampling period (Ts) - The sampling interval used for decoding the WSS signal.
• Teletext (TXT) - The Teletext service used here for subtitle signalling.

Who uses SIST ETS 300 294 E1:2003?

Broadcasters use SIST ETS 300 294 E1:2003 when they need to signal 16:9, letterbox, film, or subtitle information in 625-line PAL or SECAM services. It is also relevant to PALplus and other enhanced television services that need reserved signalling bits for future use.

Receiver manufacturers and decoder designers use it to implement automatic aspect-ratio switching, subtitle handling, and Teletext detection. Test and quality teams use it to verify line 23 insertion, bit coding, parity, and response to the signalled display mode.

Which standards are used with SIST ETS 300 294 E1:2003?

SIST ETS 300 294 E1:2003 cites EBU Recommendation R62 (1990), "Recommendation dominant field for 625-line 50Hz processing". It contributes the field-dominance rule used when the film bit indicates film mode.

What does the SIST ETS 300 294 E1:2003 document contain?

The document contains a transmission scheme for WSS, shown in Table 1, that defines the bit groups, preamble, parity, and coding order. It includes code tables for aspect ratio labels, aspect ratio ranges, the film bit, subtitle signalling, and subtitling mode in Tables 2 to 6.

Figure 1 shows where the signal is inserted in line 23, and Figure 2 shows the bi-phase coding example. Figure 3 illustrates subtitle positions relative to the active image area.

Annex A gives receiver-side operating rules for display format selection, subtitle handling, and behavior when signalling is absent. Annex B gives practical recommendations for filtering and response time, which are useful when designing or testing receivers.

SLOVENSKI STANDARD
01-december-2003
7HOHYL]LMVNLVLVWHPL±6LJQDOL]DFLMD:66SULãLURNR]DVORQVNLYUVWLþQLWHOHYL]LML
Television systems; 625-line television Wide Screen Signalling (WSS)
Ta slovenski standard je istoveten z: ETS 300 294 Edition 1
ICS:
33.160.25 Televizijski sprejemniki Television receivers
33.170 Televizijska in radijska Television and radio
difuzija broadcasting
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN ETS 300 294
TELECOMMUNICATION November 1994
STANDARD
Source: EBU/ETSI JTC Reference: DE/JTC-WSS
ICS: 33.160.20, 33.160.40
Wide Screen Signalling (WSS), analogue television, 16:9 aspect ratio
Key words:
Television Systems;
625-Line television
Wide Screen Signalling (WSS)
ETSI
European Telecommunications Standards Institute
ETSI Secretariat
Postal address: F-06921 Sophia Antipolis CEDEX - FRANCE
Office address: 650 Route des Lucioles - Sophia Antipolis - Valbonne - FRANCE
X.400: c=fr, a=atlas, p=etsi, s=secretariat - Internet: [e-mail]
Tel.: [phone] - Fax: [phone]
Copyright Notification: No part may be reproduced except as authorized by written permission. The copyright and the
foregoing restriction extend to reproduction in all media.
© European Telecommunications Standards Institute 1994.
© European Broadcasting Union 1994.
All rights reserved.
New presentation - see History box

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ETS 300 294: November 1994
Whilst every care has been taken in the preparation and publication of this document, errors in content,
typographical or otherwise, may occur. If you have comments concerning its accuracy, please write to "ETSI
Editing and Committee Support Dept." at the address shown on the title page.

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ETS 300 294: November 1994
Contents
Foreword.5
Introduction .5
1 Scope .7
2 Normative references.7
3 Definitions symbols and abbreviations .7
3.1 Definitions .7
3.2 Symbols and abbreviations.7
4 Requirements .7
4.1 Line code.7
4.1.1 Position.8
4.1.2 Clock frequency.8
4.1.3 Signal shape.8
4.1.4 Signal amplitude .8
4.1.5 Modulation coding .9
4.1.6 Preamble .9
4.1.7 Data bits .9
4.1.8 Odd parity bit .9
4.2 Information content of data bits.11
4.2.1 Data group 1.11
4.2.1.1 Aspect ratio.11
4.2.2 Data group 2, enhanced services.12
4.2.2.1 Film bit .12
4.2.2.2 Bit b , b and b .12
5 6 7
4.2.3 Data group 3, subtitles.12
4.2.3.1 Subtitles within teletext bit.12
4.2.3.2 Subtitling mode .13
4.2.4 Data group 4, reserved.13
Annex A (informative): Rules of operation.14
A.1 Receiver display formats .14
A.2 Subtitling.15
A.3 Procedure in absence of signalling.15
Annex B (informative): Recommendations.16
B.1 Low pass pre-filtering .16
B.2 Response time on a change in the received signalling information .16
History.17

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ETS 300 294: November 1994
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ETS 300 294: November 1994
Foreword
This European Telecommunication Standard (ETS) has been produced under the authority of the Joint
Technical Committee (JTC) of the European Broadcasting Union (EBU) and the European Telecommunications
Standards Institute (ETSI), it was prepared by the Taskforce 16:9 of the PALplus group after consulting both the
EBU V/EPS and EBU/V2 groups.
This ETS defines the Wide Screen Signalling (WSS) information for 625 line PAL and SECAM television
systems.
NOTE: The EBU/ETSI JTC was established in 1990 to coordinate the drafting of European
Telecommunication Standards in the specific fields of radio, television and data
broadcasting.
The EBU is a professional association of broadcasting organizations whose work includes
coordination of its Members activities in the technical, legal, programme-making and
programme-exchange domains. The EBU has active members in about 50 Countries in
the European Broadcasting area; its headquarters is in Geneva *.
* European Broadcasting Union
Case Postale 67
CH-1218 GRAND SACONNEX (Geneva)
Switzerland
Tel: [phone]
Fax: [phone]
Transposition dates
Date of latest announcement of this ETS (doa): 28 February 1995
Date of latest publication of new National Standard
or endorsement of this ETS (dop/e): 31 August 1995
Date of withdrawal of any conflicting National Standard (dow): 31 August 1995
Introduction
For a smooth introduction of new television services with a 16:9 display aspect ratio in PAL and SECAM
standards, it is necessary to signal the aspect ratio used together with some switching information to the
television receiver. The receiver should be capable of reacting automatically to this information by displaying the
video information in a specified aspect ratio. This signalling is to be considered separately from the type of
system used, but it should allow transmission of system related switching information as well.
This ETS permits the later allocation of additional switching information, related to the introduction of enhanced
television services.
This ETS is applicable for 625 line PAL and SECAM television systems, but there is potential to adopt it to other
standards as well.
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ETS 300 294: November 1994
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ETS 300 294: November 1994
1 Scope
This European Telecommunication Standard (ETS) is applicable to 625 line PAL and SECAM systems in use, in
case, where wide-screen signalling is required by the broadcasters.
It specifies the wide screen signalling information, the coding and the way of incorporating the coded information
into a 625 line system.
The wide screen signalling information contains information on the aspect ratio range of the transmitted signal
and its position, on the position of the subtitles and on the camera/film mode. Furthermore some bits are
reserved for future EDTV signalling (e.g. PALplus) as well as for future use.
This ETS specifies the transmitted signal. Annex A gives the rules of operation for the minimum requirements
for receiver display formats as well as for subtitling.
2 Normative references
This ETS incorporates by dated and undated reference, provisions from other publications. These normative
references are cited at the appropriate places in the text and the publications are listed hereafter. For dated
references, subsequent amendments to or revisions of any of these publications apply to this ETS only when
incorporated in it by amendment or revision. For undated references the latest edition of the publication referred
to applies.
[1] EBU Recommendation R62 (1990): "Recommendation dominant field for 625-
line 50Hz processing".
3 Definitions symbols and abbreviations
3.1 Definitions
For the purpose of this ETS, the following definition applies:
letterbox operation: Is the use of a picture format with an aspect ratio greater than 1,33, in such a way that
empty (black) lines are added to conform to a 4:3 transmission format.
3.2 Symbols and abbreviations
For the purpose of this ETS, the following s
...