SIST EN 300 472 V1.3.1:2005

• Abstract:

  Revision based on TM 1241 Rev. 4.

• Status: Published
• Publication Date: 31-Oct-2005
• ICS: 33.170 - Television and radio broadcasting
• Technical Committee: RES - Radio equipment and systems
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 01-Nov-2005
• Due Date: 01-Nov-2005
• Completion Date: 01-Nov-2005
• Mandate: T-304
• Ref Project: ETSI EN 300 472 V1.3.1 (2003-05) - Digital Video Broadcasting (DVB); Specification for conveying ITU-R System B Teletext in DVB bitstreams

SIST EN 300 472 V1.3.1:2005 is the Slovenian adoption of ETSI EN 300 472 V1.3.1, a DVB standard for carrying ITU-R System B Teletext in DVB bitstreams. It tells broadcasters, multiplexers, and receiver or decoder designers how Teletext data are signalled, packetized, and timed in MPEG-2 transport streams. In practice, it is the document to use when Teletext must be transported so it can also be transcoded to the analogue VBI and decoded with the right presentation timing.

What does SIST EN 300 472 V1.3.1:2005 specify?

SIST EN 300 472 V1.3.1:2005 specifies the method for conveying ITU-R System B Teletext, also known as EBU Teletext, in DVB bitstreams. The scope is focused on transport, signalling, and timing for Teletext services, especially where the data may be transcoded into the Vertical Blanking Interval (VBI) of analogue video.

The document also states the intended transport constraints: compatibility with existing TV receivers with Teletext decoders, a maximum rate equivalent to 16 lines per field for each Teletext service, and timing accurate enough for subtitles near frame accuracy. General-purpose new data-service transport is outside the scope, although the syntax defined here can be adapted to other data.

Annex	What it covers
Annex A	Informative notes on PTS transmission

The document is organized into scope, references, definitions and abbreviations, insertion of Teletext into the MPEG-2 transport multiplex, a Teletext decoder model, and an informative annex on PTS transmission.

What are the key requirements of SIST EN 300 472 V1.3.1:2005?

SIST EN 300 472 V1.3.1:2005 requires Teletext to be carried in Packetized Elementary Stream (PES) packets, which are then carried in Transport Stream (TS) packets as defined in ISO/IEC 13818-1. For implementers, this means Teletext is not sent as an ad hoc payload - it follows MPEG-2 transport rules.

Signalling and stream identification

Clause 4 requires the Teletext stream PID to be listed in the Program Map Table (PMT) of the service’s Program Specific Information (PSI). The stream_type value is 0x06, and the ES_info field shall contain a Teletext descriptor from EN 300 468. This is what lets a receiver recognize that the stream carries Teletext and link it to the correct service.

A service may carry more than one Teletext data stream if each stream uses a different data_identifier and the descriptors keep the streams distinguishable. In practice, that allows separate Teletext flows, such as different content types, to coexist without ambiguity.

Packet formatting constraints

Clause 4.1 limits the TS packet adaptation_field_control to the values "01" and "10". Clause 4.2 fixes the PES stream_id to private_stream_1, sets the PES packet length so the packet ends on a transport packet boundary, and requires data_alignment_indicator to be set to "1". For packagers, this means the PES structure is tightly constrained to support clean mapping into TS packets.

Clause 4.3 defines the PES data field syntax, including data_identifier, data_unit_id, data_unit_length, and the Teletext data_field. Clause 4.4 then restricts the coded values used for EBU Teletext data, including the permitted data_unit_id values, the fixed data_unit_length for EBU Teletext data, and the allowed line_offset range. That matters because a conforming encoder must generate exactly the values the decoder expects.

Teletext packet order and timing

Clause 4.4 says the Teletext packet bytes are placed in the same order as they are meant to arrive at the decoder or be transcoded into the VBI. That preserves the logical order of Teletext content and avoids reassembly errors.

Clause 5 defines the Teletext decoder model. A Teletext access unit is a Teletext data packet, the PTS applies to the first access unit after that PTS field, and the model uses buffer and timing constraints, including a 40 ms maximum residence time in the buffer. For implementation, this means the transmitter and receiver must keep Teletext synchronized closely enough for display or VBI insertion.

Annex A adds practical guidance on PTS transmission: encoders should support inserting PTS whenever possible, and decoders may use PTS for synchronization but must also be able to decode within the 40 ms limit.

What terms does SIST EN 300 472 V1.3.1:2005 define?

• MPEG-2 - The coding family used here for systems transport, video, and audio; this standard uses its transport layer.
• section - The syntactic structure used to map Service Information into TS packets.
• service - A broadcaster-controlled sequence of programmes that can be scheduled and broadcast together.
• Teletext descriptor - The descriptor in the PMT that identifies streams carrying EBU data.
• Packetized Elementary Stream (PES) - The packet form used to carry Teletext data before it is placed into TS packets.
• Transport Stream (TS) - The MPEG-2 transport packet structure used for DVB delivery.
• Presentation Time Stamp (PTS) - The timing reference used to present or insert Teletext access units at the intended time.
• Vertical Blanking Interval (VBI) - The analogue video interval where Teletext may be transcoded for legacy receivers.

Who uses SIST EN 300 472 V1.3.1:2005?

This standard is used by DVB broadcasters, head-end and multiplexer engineers, Teletext encoder developers, receiver and set-top-box designers, and test or quality teams validating service carriage. It is relevant in digital television systems where Teletext must remain compatible with analogue-style VBI workflows or existing Teletext receivers. It also helps teams responsible for service signalling in PSI/PMT and for checking timing and packet alignment during integration.

Which standards are used with SIST EN 300 472 V1.3.1:2005?

Clause 2 names four referenced standards and recommendations that define the surrounding Teletext and DVB framework:

• ISO/IEC 13818-1 - Provides the MPEG-2 systems layer used for TS and PES packetization.
• ETSI EN 300 468 - Defines Service Information, including the PMT and the Teletext descriptor.
• ITU-R Recommendation BT.653 - Defines Teletext systems and the Teletext packet structure referenced here.
• ETSI EN 300 706 - Gives the Enhanced Teletext specification, also referenced as the EBU Teletext definition.

What does the SIST EN 300 472 V1.3.1:2005 document contain?

The document contains the transport syntax for inserting Teletext into the MPEG-2 transport multiplex, including the PES and TS packet constraints. It includes tables for the PES data field and the Teletext data field, plus tables for data_identifier, data_unit_id, and line_offset values. It also includes a conceptual Teletext decoder model with buffer and timing behaviour, which is useful for implementation and verification. Annex A provides informative guidance on how PTS is used in practice.

SLOVENSKI STANDARD
01-november-2005
Digitalna videoradiodifuzija (DVB) – Specifikacija za prenos teleteksta po
standardu ITU-R sistem B v bitnih tokih digitalne videoradiodifuzije
Digital Video Broadcasting (DVB); Specification for conveying ITU-R System B Teletext
in DVB bitstreams
Ta slovenski standard je istoveten z: EN 300 472 Version 1.3.1
ICS:
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 Standard (Telecommunications series)

Digital Video Broadcasting (DVB);
Specification for conveying ITU-R System B Teletext
in DVB bitstreams
European Broadcasting Union Union Européenne de Radio-Télévision
EBU·UER
2 ETSI EN 300 472 V1.3.1 (2003-05)

Reference
REN/JTC-DVB-143
Keywords
broadcasting, digital, DVB, MPEG, teletext, TV,
video
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ETSI
3 ETSI EN 300 472 V1.3.1 (2003-05)
Contents
Intellectual Property Rights.4
Foreword.4
1 Scope.5
2 References.5
3 Definitions and abbreviations.5
3.1 Definitions.5
3.2 Abbreviations.6
4 Insertion of Teletext into MPEG-2 transport multiplex .6
4.1 Transport Stream (TS) packet format.6
4.2 PES packet format.6
4.3 Syntax for PES data field .7
4.4 Semantics for PES data field .7
5 Teletext decoder model .9
Annex A (informative): PTS transmission .10
History .11

ETSI
4 ETSI EN 300 472 V1.3.1 (2003-05)
Intellectual Property Rights
IPRs essential or potentially essential to the present document may have been declared to ETSI. The information
pertaining to these essential IPRs, if any, is publicly available for ETSI members and non-members, and can be found
in ETSI SR 000 314: "Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in
respect of ETSI standards", which is available from the ETSI Secretariat. Latest updates are available on the ETSI Web
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All published ETSI deliverables shall include information which directs the reader to the above source of information.
Foreword
This European Standard (Telecommunications series) has been produced by Joint Technical Committee (JTC)
Broadcast of the European Broadcasting Union (EBU), Comité Européen de Normalisation ELECtrotechnique
(CENELEC) and the European Telecommunications Standards Institute (ETSI).
NOTE: The EBU/ETSI JTC Broadcast was established in 1990 to co-ordinate the drafting of standards in the
specific field of broadcasting and related fields. Since 1995 the JTC Broadcast became a tripartite body
by including in the Memorandum of Understanding also CENELEC, which is responsible for the
standardization of radio and television receivers. The EBU is a professional association of broadcasting
organizations whose work includes the co-ordination of its members' activities in the technical, legal,
programme-making and programme-exchange domains. The EBU has active members in about
60 countries in the European broadcasting area; its headquarters is in Geneva.
European Broadcasting Union
CH-1218 GRAND SACONNEX (Geneva)
Switzerland
Tel: [phone]
Fax: [phone]
Founded in September 1993, the DVB Project is a market-led consortium of public and private sector organizations in
the television industry. Its aim is to establish the framework for the introduction of MPEG-2 based digital television
services. Now comprising over 200 organizations from more than 25 countries around the world, DVB fosters
market-led systems, which meet the real needs, and economic circumstances, of the consumer electronics and the
broadcast industry.
National transposition dates
Date of adoption of this EN: 23 May 2003
Date of latest announcement of this EN (doa): 31 August 2003
Date of latest publication of new National Standard
or endorsement of this EN (dop/e): 29 February 2004
Date of withdrawal of any conflicting National Standard (dow): 29 February 2004

ETSI
5 ETSI EN 300 472 V1.3.1 (2003-05)
1 Scope
The present document specifies the method by which ITU-R System B Teletext (ITU-R Recommendation BT.653 [3]),
also known as EBU Teletext (see EN 300 706 [4]), may be carried in DVB bitstreams. This transport mechanism is
intended to satisfy the following requirements:
- to support the transcoding of the Teletext data into the Vertical Blanking Interval (VBI) of analogue video.
The transcoded signal should be compatible with existing TV receivers with Teletext decoders;
- the maximum data rate for each Teletext service is equivalent to 16 lines per field so that the service is always
suitable for transcoding into the VBI;
- the transmission mechanism should be capable of transmitting subtitles with accurate timing with respect to
the video (i.e. to within or near frame accuracy).
A more general data transport mechanism for conveying new types of data services is outside the scope of the present
document, but the transport syntax specified here can also be adapted for other data.
2 References
The following documents contain provisions which, through reference in this text, constitute provisions of the present
document.
• References are either specific (identified by date of publication and/or edition number or version number) or
non-specific.
• For a specific reference, subsequent revisions do not apply.
• For a non-specific reference, the latest version applies.
Referenced documents which are not found to be publicly available in the expected location might be found at
http://docbox.etsi.org/Reference.
[1] ISO/IEC 13818-1: "Information technology - Generic coding of moving pictures and associated
audio information: Systems".
[2] ETSI EN 300 468: "Digital Video Broadcasting (DVB); Specification for Service Information (SI)
in DVB systems".
[3] ITU-R Recommendation BT.653: "Teletext systems".
[4] ETSI EN 300 706: "Enhanced Teletext specification".
3 Definitions and abbreviations
3.1 Definitions
For the purposes of the present document, the following terms and definitions apply.
MPEG-2: Refers to the standard ISO/IEC 13818. Systems coding is defined in part 1 [1]. Video coding is defined in
part 2. Audio coding is defined in part 3 of ISO/IEC 13818.
section: syntactic structure used for mapping all service information defined in EN 300 468 into ISO/IEC 13818-1
Transport Stream (TS) packets
service: sequence of programmes under the control of a broadcaster which can be broadcast as part of a schedul
...