ETSI EN 300 743 V1.6.1 (2018-10)

Digital Video Broadcasting (DVB); Subtitling systems

REN/JTC-DVB-378

Digitalna videoradiodifuzija (DVB) - Sistemi za podnaslove

Ta dokument določa metodo, s katero je mogoče kodirati podnaslove, logotipe in druge grafične elemente ter jih prenašati v bitnih tokih digitalne radiodifuzije (DVB). Sistem uporablja barvne tabele (CLUT) za določanje barv grafičnih elementov. Prenos kodiranih grafičnih elementov temelji na pretoku prenosov MPEG-2, opisanem v standardu ISO/IEC 13818-1 [1].

General Information

• Status: Published
• Publication Date: 29-Oct-2018
• Technical Committee: BROADCAS - EBU/CENELEC/ETSI on Broadcasting
• Current Stage: 12 - Completion
• Due Date: 05-Nov-2018
• Completion Date: 30-Oct-2018
• Ref Project: SIST EN 300 743 V1.6.1:2019 - Digital Video Broadcasting (DVB) - Subtitling systems

Standards Content (Sample)

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Digitalna videoradiodifuzija (DVB) - Sistemi za podnasloveDigital Video Broadcasting (DVB) - Subtitling systems33.170Televizijska in radijska difuzijaTelevision and radio broadcastingICS:Ta slovenski standard je istoveten z:ETSI EN 300 743 V1.6.1 (2018-10)SIST EN 300 743 V1.6.1:2019en01-januar-2019SIST EN 300 743 V1.6.1:2019SLOVENSKI
STANDARD



SIST EN 300 743 V1.6.1:2019



ETSI EN 300 743 V1.6.1 (2018-10) Digital Video Broadcasting (DVB); Subtitling systems
EUROPEAN STANDARD SIST EN 300 743 V1.6.1:2019



ETSI ETSI EN 300 743 V1.6.1 (2018-10) 2
Reference REN/JTC-DVB-378 Keywords broadcasting, digital, DVB, TV, video ETSI 650 Route des Lucioles F-06921 Sophia Antipolis Cedex - FRANCE
Tel.: [phone]
Fax: [phone]
Siret N° 348 623 562 00017 - NAF 742 C Association à but non lucratif enregistrée à la Sous-Préfecture de Grasse (06) N° 7803/88
Important notice The present document can be downloaded from: http://www.etsi.org/standards-search The present document may be made available in electronic versions and/or in print. The content of any electronic and/or print versions of the present document shall not be modified without the prior written authorization of ETSI. In case of any existing or perceived difference in contents between such versions and/or in print, the only prevailing document is the print of the Portable Document Format (PDF) version kept on a specific network drive within ETSI Secretariat. Users of the present document should be aware that the document may be subject to revision or change of status. Information on the current status of this and other ETSI documents is available at https://portal.etsi.org/TB/ETSIDeliverableStatus.aspx If you find errors in the present document, please send your comment to one of the following services: https://portal.etsi.org/People/CommiteeSupportStaff.aspx Copyright Notification No part may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm except as authorized by written permission of ETSI. The content of the PDF version shall not be modified without the written authorization of ETSI. The copyright and the foregoing restriction extend to reproduction in all media.
© ETSI 2018. © European Broadcasting Union 2018. All rights reserved.
DECTTM, PLUGTESTSTM, UMTSTM and the ETSI logo are trademarks of ETSI registered for the benefit of its Members. 3GPPTM and LTETM are trademarks of ETSI registered for the benefit of its Members and of the 3GPP Organizational Partners. oneM2M™ logo is a trademark of ETSI registered for the benefit of its Members and of the oneM2M Partners GSM® and the GSM logo are trademarks registered and owned by the GSM Association. SIST EN 300 743 V1.6.1:2019



ETSI ETSI EN 300 743 V1.6.1 (2018-10) 3 Contents Intellectual Property Rights . 6 Foreword . 6 Modal verbs terminology . 7 1 Scope . 8 2 References . 8 2.1 Normative references . 8 2.2 Informative references . 9 3 Definitions and abbreviations . 9 3.1 Definitions . 9 3.2 Abbreviations . 10 4 Introduction to the DVB subtitling system (informative) . 12 4.1 General . 12 4.2 Subtitling system evolution and service compatibility . 12 4.2.1 Introduction. 12 4.2.2 V1.1.1 and V1.2.1 . 12 4.2.3 V1.3.1 . 13 4.2.4 V1.4.1 and V1.5.1 . 13 4.2.5 V1.6.1 . 13 4.2.6 General subtitle service compatibility issues . 14 4.3 Basic concepts and terminology . 14 4.4 Subtitle stream composition . 15 4.5 Subtitle segment coding . 16 4.6 Subtitle stream transport . 17 4.7 Subtitling data hierarchy . 19 4.8 Temporal hierarchy and terminology . 19 5 Subtitle decoder model and subtitle stream provision . 20 5.0 Introduction . 20 5.1 General principles. 21 5.1.0 The subtitle epoch . 21 5.1.1 Subtitle service acquisition . 21 5.1.2 Presentation Time Stamps (PTS) . 21 5.1.3 Usage of the display definition segment . 22 5.1.4 Page composition . 22 5.1.5 Region composition . 22 5.1.6 Points to note . 23 5.2 Buffer memory model . 23 5.2.0 General . 23 5.2.1 Pixel buffer memory . 24 5.2.2 Region memory . 24 5.2.3 Composition buffer memory . 24 5.3 Cumulative display construction . 24 5.4 Decoder rendering bandwidth model . 24 5.4.0 General . 24 5.4.1 Page erasure . 25 5.4.2 Region move or change in visibility . 25 5.4.3 Region fill . 25 5.4.4 CLUT modification. 25 5.4.5 Graphic object decoding . 25 5.4.6 Character object decoding . 26 6 Subtitle stream carriage in the PES layer and in the Transport Stream, and signalling . 26 6.1 General . 26 6.2 Carriage in the PES layer . 26 6.3 Carriage and signalling in the transport stream . 27 SIST EN 300 743 V1.6.1:2019



ETSI ETSI EN 300 743 V1.6.1 (2018-10) 4 7 Subtitling service data specification . 28 7.1 Introduction . 28 7.2 Syntax and semantics of the subtitling segment . 28 7.2.0 General . 28 7.2.0.1 Segment syntax . 28 7.2.0.2 Forward compatibility . 30 7.2.1 Display definition segment . 30 7.2.2 Page composition segment . 32 7.2.3 Region composition segment . 34 7.2.4 CLUT definition segment . 36 7.2.5 Object data segment . 38 7.2.5.0 General . 38 7.2.5.1 Pixel-data sub-block . 41 7.2.5.2 Syntax and semantics of the pixel code strings . 42 7.2.5.2.1 2-bits per pixel code . 42 7.2.5.2.2 4-bits per pixel code . 43 7.2.5.2.3 8-bits per pixel code . 44 7.2.5.3 Progressive pixel block . 45 7.2.6 End of display set segment . 46 7.2.7 Disparity Signalling Segment . 46 7.2.8 Alternative CLUT segment . 52 7.3 Interoperability points . 54 8 Requirements for the subtitling data . 55 8.0 General . 55 8.1 Scope of Identifiers . 55 8.2 Scope of dependencies . 55 8.2.1 Composition page . 55 8.2.2 Ancillary page . 55 8.3 Order of delivery . 56 8.4 Positioning of regions and objects . 56 8.4.1 Regions . 56 8.4.2 Objects sharing a PTS . 56 8.4.3 Objects added to a region . 56 9 Translation to colour components . 56 9.0 General . 56 9.1 4- to 2-bit reduction . 57 9.2 8- to 2-bit reduction . 58 9.3 8- to 4-bit reduction . 58 10 Default CLUTs and map-tables contents . 58 10.0 General . 58 10.1 256-entry CLUT default contents . 58 10.2 16-entry CLUT default contents . 59 10.3 4-entry CLUT default contents . 60 10.4 2_to_4-bit_map-table default contents . 61 10.5 2_to_8-bit_map-table default contents . 61 10.6 4_to_8-bit_map-table default contents . 61 11 Structure of the pixel code strings (informative) . 62 12 Subtitle rendering issues . 63 12.1 Introduction . 63 12.2 Spatial scaling of subtitles . 63 12.3 Rendering subtitles over video with a different colour system . 63 Annex A (informative): How the DVB subtitling system works . 65 A.0 Introduction . 65 A.1 Data hierarchy and terminology . 65 A.2 Temporal hierarchy and terminology . 65 SIST EN 300 743 V1.6.1:2019



ETSI ETSI EN 300 743 V1.6.1 (2018-10) 5 A.3 Decoder temporal model . 65 A.4 Decoder display technology model . 65 A.4.1 Region based with indexed colours . 65 A.4.2 Colour quantization . 66 A.5 Examples of the subtitling system in operation . 66 A.5.1 Double buffering . 66 A.5.1.0 General . 66 A.5.1.1 Instant graphics . 66 A.5.1.2 Stenographic subtitles . 69 Annex B (informative): Use of the DDS for SDTV, HDTV and UHDTV services . 72 B.1 Introduction . 72 B.2 SDTV services . 72 B.3 HDTV services . 72 B.4 UHDTV services . 73 Annex C (informative): Illustration of the application of the disparity_shift_update_sequence mechanism for 3D content . 74 Annex D (informative): Guidelines on the use of ETSI EN 300 743 for 3D content . 78 Annex E (informative): Conversion of PNG files into progressively coded bitmap subtitles . 82 Annex F (informative): Bibliography . 84 History . 85
SIST EN 300 743 V1.6.1:2019



ETSI ETSI EN 300 743 V1.6.1 (2018-10) 6 Intellectual Property Rights Essential patents IPRs essential or potentially essential to normative deliverables 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 server (https://ipr.etsi.org/). Pursuant to the ETSI IPR Policy, no investigation, including IPR searches, has been carried out by ETSI. No guarantee can be given as to the existence of other IPRs not referenced in ETSI SR 000 314 (or the updates on the ETSI Web server) which are, or may be, or may become, essential to the present document. Trademarks The present document may include trademarks and/or tradenames which are asserted and/or registered by their owners. ETSI claims no ownership of these except for any which are indicated as being the property of ETSI, and conveys no right to use or reproduce any trademark and/or tradename. Mention of those trademarks in the present document does not constitute an endorsement by ETSI of products, services or organizations associated with those trademarks. Foreword This European Standard (EN) 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]
The Digital Video Broadcasting Project (DVB) is an industry-led consortium of broadcasters, manufacturers, network operators, software developers, regulatory bodies, content owners and others committed to designing global standards for the delivery of digital television and data services. DVB fosters market driven solutions that meet the needs and economic circumstances of broadcast industry stakeholders and consumers. DVB standards cover all aspects of digital television from transmission through interfacing, conditional access and interactivity for digital video, audio and data. The consortium came together in 1993 to provide global standardization, interoperability and future proof specifications.
National transposition dates Date of adoption of this EN: 22 October 2018 Date of latest announcement of this EN (doa): 31 January 2019 Date of latest publication of new National Standard or endorsement of this EN (dop/e):
31 July 2019 Date of withdrawal of any conflicting National Standard (dow): 31 July 2019 SIST EN 300 743 V1.6.1:2019



ETSI ETSI EN 300 743 V1.6.1 (2018-10) 7 Modal verbs terminology In the present document "shall", "shall not", "should", "should not", "may", "need not", "will", "will not", "can" and "cannot" are to be interpreted as described in clause 3.2 of the ETSI Drafting Rules (Verbal forms for the expression of provisions). "must" and "must not" are NOT allowed in ETSI deliverables except when used in direct citation.
SIST EN 300 743 V1.6.1:2019



ETSI ETSI EN 300 743 V1.6.1 (2018-10) 8 1 Scope The present document specifies the method by which subtitles, logos and other graphical elements may be coded and carried in DVB bitstreams. The system applies Colour Look-Up Tables (CLUTs) to define the colours of the graphical elements. The transport of the coded graphical elements is based on the MPEG-2 Transport Stream described in ISO/IEC 13818-1 [1]. 2 References 2.1 Normative references References are either specific (identified by date of publication and/or edition number or version number) or non-specific. For specific references, only the cited version applies. For non-specific references, the latest version of the referenced document (including any amendments) applies. Referenced documents which are not found to be publicly available in the expected location might be found at https://docbox.etsi.org/Reference/. NOTE: While any hyperlinks included in this clause were valid at the time of publication ETSI cannot guarantee their long term validity. The following referenced documents are necessary for the application of the present document. [1] ISO/IEC 13818-1: "Information technology - Generic coding of moving pictures and associated audio information. Part 1: Systems". [2] ETSI EN 300 468: "Digital Video Broadcasting (DVB); Specification for Service Information (SI) in DVB systems". [3] Recommendation ITU-R BT.601: "Studio encoding parameters of digital television for standard 4:3 and wide-screen 16:9 aspect ratios". [4] Recommendation ITU-R BT.656-4: "Interface for digital component video signals in 525-line and 625-line television systems operating at the 4:2:2 level of Recommendation ITU-R BT.601 (Part A)". [5] ETSI EN 300 743 (V1.2.1): "Digital Video Broadcasting (DVB); Subtitling systems". [6] ETSI EN 300 743 (V1.3.1): "Digital Video Broadcasting (DVB); Subtitling systems". [7] ETSI EN 300 743 (V1.4.1): "Digital Video Broadcasting (DVB); Subtitling systems". [8] ETSI EN 300 743 (V1.5.1): "Digital Video Broadcasting (DVB); Subtitling systems". [9] ETSI TS 101 154: "Digital Video Broadcasting (DVB); Specification for the use of Video and Audio Coding in Broadcasting Applications based on the MPEG-2 Transport Stream". [10] Recommendation ITU-R BT.709: "Parameter values for the HDTV standards for production and international programme exchange". [11] Recommendation ITU-R BT.2020-2: "Parameter values for ultra-high definition television systems for production and international programme exchange". [12] Recommendation ITU-R BT.2100-1: "Image parameter values for high dynamic range television for use in production and international programme exchange". [13] Recommendation ITU-R BT.1886: "Reference electro-optical transfer function for flat panel displays used in HDTV studio production". [14] IETF RFC 1950: "ZLIB Compressed Data Format Specification", (Version 3.3). [15] IETF RFC 1951: "DEFLATE Compressed Data
...

ETSI EN 300 743 V1.6.1 (2018-10)






EUROPEAN STANDARD
Digital Video Broadcasting (DVB);
Subtitling systems

---------------------- Page: 1 ----------------------
2 ETSI EN 300 743 V1.6.1 (2018-10)



Reference
REN/JTC-DVB-378
Keywords
broadcasting, digital, DVB, TV, video
ETSI
650 Route des Lucioles
F-06921 Sophia Antipolis Cedex - FRANCE

Tel.: [phone]  Fax: [phone]

Siret N° 348 623 562 00017 - NAF 742 C
Association à but non lucratif enregistrée à la
Sous-Préfecture de Grasse (06) N° 7803/88

Important notice
The present document can be downloaded from:
http://www.etsi.org/standards-search
The present document may be made available in electronic versions and/or in print. The content of any electronic and/or
print versions of the present document shall not be modified without the prior written authorization of ETSI. In case of any
existing or perceived difference in contents between such versions and/or in print, the only prevailing document is the
print of the Portable Document Format (PDF) version kept on a specific network drive within ETSI Secretariat.
Users of the present document should be aware that the document may be subject to revision or change of status.
Information on the current status of this and other ETSI documents is available at
https://portal.etsi.org/TB/ETSIDeliverableStatus.aspx
If you find errors in the present document, please send your comment to one of the following services:
https://portal.etsi.org/People/CommiteeSupportStaff.aspx
Copyright Notification
No part may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying
and microfilm except as authorized by written permission of ETSI.
The content of the PDF version shall not be modified without the written authorization of ETSI.
The copyright and the foregoing restriction extend to reproduction in all media.

© ETSI 2018.
© European Broadcasting Union 2018.
All rights reserved.

TM TM TM
DECT , PLUGTESTS , UMTS and the ETSI logo are trademarks of ETSI registered for the benefit of its Members.
TM TM
3GPP and LTE are trademarks of ETSI registered for the benefit of its Members and
of the 3GPP Organizational Partners.
oneM2M™ logo is a trademark of ETSI registered for the benefit of its Members and
of the oneM2M Partners
®
GSM and the GSM logo are trademarks registered and owned by the GSM Association.
ETSI

---------------------- Page: 2 ----------------------
3 ETSI EN 300 743 V1.6.1 (2018-10)
Contents
Intellectual Property Rights . 6
Foreword . 6
Modal verbs terminology . 7
1 Scope . 8
2 References . 8
2.1 Normative references . 8
2.2 Informative references . 9
3 Definitions and abbreviations . 9
3.1 Definitions . 9
3.2 Abbreviations . 10
4 Introduction to the DVB subtitling system (informative) . 12
4.1 General . 12
4.2 Subtitling system evolution and service compatibility . 12
4.2.1 Introduction. 12
4.2.2 V1.1.1 and V1.2.1 . 12
4.2.3 V1.3.1 . 13
4.2.4 V1.4.1 and V1.5.1 . 13
4.2.5 V1.6.1 . 13
4.2.6 General subtitle service compatibility issues . 14
4.3 Basic concepts and terminology . 14
4.4 Subtitle stream composition . 15
4.5 Subtitle segment coding . 16
4.6 Subtitle stream transport . 17
4.7 Subtitling data hierarchy . 19
4.8 Temporal hierarchy and terminology . 19
5 Subtitle decoder model and subtitle stream provision . 20
5.0 Introduction . 20
5.1 General principles. 21
5.1.0 The subtitle epoch . 21
5.1.1 Subtitle service acquisition . 21
5.1.2 Presentation Time Stamps (PTS) . 21
5.1.3 Usage of the display definition segment . 22
5.1.4 Page composition . 22
5.1.5 Region composition . 22
5.1.6 Points to note . 23
5.2 Buffer memory model . 23
5.2.0 General . 23
5.2.1 Pixel buffer memory . 24
5.2.2 Region memory . 24
5.2.3 Composition buffer memory . 24
5.3 Cumulative display construction . 24
5.4 Decoder rendering bandwidth model . 24
5.4.0 General . 24
5.4.1 Page erasure . 25
5.4.2 Region move or change in visibility . 25
5.4.3 Region fill . 25
5.4.4 CLUT modification. 25
5.4.5 Graphic object decoding . 25
5.4.6 Character object decoding . 26
6 Subtitle stream carriage in the PES layer and in the Transport Stream, and signalling . 26
6.1 General . 26
6.2 Carriage in the PES layer . 26
6.3 Carriage and signalling in the transport stream . 27
ETSI

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4 ETSI EN 300 743 V1.6.1 (2018-10)
7 Subtitling service data specification . 28
7.1 Introduction . 28
7.2 Syntax and semantics of the subtitling segment . 28
7.2.0 General . 28
7.2.0.1 Segment syntax . 28
7.2.0.2 Forward compatibility . 30
7.2.1 Display definition segment . 30
7.2.2 Page composition segment . 32
7.2.3 Region composition segment . 34
7.2.4 CLUT definition segment . 36
7.2.5 Object data segment . 38
7.2.5.0 General . 38
7.2.5.1 Pixel-data sub-block . 41
7.2.5.2 Syntax and semantics of the pixel code strings . 42
7.2.5.2.1 2-bits per pixel code . 42
7.2.5.2.2 4-bits per pixel code . 43
7.2.5.2.3 8-bits per pixel code . 44
7.2.5.3 Progressive pixel block . 45
7.2.6 End of display set segment . 46
7.2.7 Disparity Signalling Segment . 46
7.2.8 Alternative CLUT segment . 52
7.3 Interoperability points . 54
8 Requirements for the subtitling data . 55
8.0 General . 55
8.1 Scope of Identifiers . 55
8.2 Scope of dependencies . 55
8.2.1 Composition page . 55
8.2.2 Ancillary page . 55
8.3 Order of delivery . 56
8.4 Positioning of regions and objects . 56
8.4.1 Regions . 56
8.4.2 Objects sharing a PTS . 56
8.4.3 Objects added to a region . 56
9 Translation to colour components . 56
9.0 General . 56
9.1 4- to 2-bit reduction . 57
9.2 8- to 2-bit reduction . 58
9.3 8- to 4-bit reduction . 58
10 Default CLUTs and map-tables contents . 58
10.0 General . 58
10.1 256-entry CLUT default contents . 58
10.2 16-entry CLUT default contents . 59
10.3 4-entry CLUT default contents . 60
10.4 2_to_4-bit_map-table default contents . 61
10.5 2_to_8-bit_map-table default contents . 61
10.6 4_to_8-bit_map-table default contents . 61
11 Structure of the pixel code strings (informative) . 62
12 Subtitle rendering issues . 63
12.1 Introduction . 63
12.2 Spatial scaling of subtitles . 63
12.3 Rendering subtitles over video with a different colour system . 63
Annex A (informative): How the DVB subtitling system works . 65
A.0 Introduction . 65
A.1 Data hierarchy and terminology . 65
A.2 Temporal hierarchy and terminology . 65
ETSI

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5 ETSI EN 300 743 V1.6.1 (2018-10)
A.3 Decoder temporal model . 65
A.4 Decoder display technology model . 65
A.4.1 Region based with indexed colours . 65
A.4.2 Colour quantization . 66
A.5 Examples of the subtitling system in operation . 66
A.5.1 Double buffering . 66
A.5.1.0 General . 66
A.5.1.1 Instant graphics . 66
A.5.1.2 Stenographic subtitles . 69
Annex B (informative): Use of the DDS for SDTV, HDTV and UHDTV services . 72
B.1 Introduction . 72
B.2 SDTV services . 72
B.3 HDTV services . 72
B.4 UHDTV services . 73
Annex C (informative): Illustration of the application of the disparity_shift_update_sequence
mechanism for 3D content . 74
Annex D (informative): Guidelines on the use of ETSI EN 300 743 for 3D content . 78
Annex E (informative): Conversion of PNG files into progressively coded bitmap subtitles . 82
Annex F (informative): Bibliography . 84
History . 85

ETSI

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6 ETSI EN 300 743 V1.6.1 (2018-10)
Intellectual Property Rights
Essential patents
IPRs essential or potentially essential to normative deliverables 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
server (https://ipr.etsi.org/).
Pursuant to the ETSI IPR Policy, no investigation, including IPR searches, has been carried out by ETSI. No guarantee
can be given as to the existence of other IPRs not referenced in ETSI SR 000 314 (or the updates on the ETSI Web
server) which are, or may be, or may become, essential to the present document.
Trademarks
The present document may include trademarks and/or tradenames which are asserted and/or registered by their owners.
ETSI claims no ownership of these except for any which are indicated as being the property of ETSI, and conveys no
right to use or reproduce any trademark and/or tradename. Mention of those trademarks in the present document does
not constitute an endorsement by ETSI of products, services or organizations associated with those trademarks.
Foreword
This European Standard (EN) 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]

The Digital Video Broadcasting Project (DVB) is an industry-led consortium of broadcasters, manufacturers, network
operators, software developers, regulatory bodies, content owners and others committed to designing global standards
for the delivery of digital television and data services. DVB fosters market driven solutions that meet the needs and
economic circumstances of broadcast industry stakeholders and consumers. DVB standards cover all aspects of digital
television from transmission through interfacing, conditional access and interactivity for digital video, audio and data.
The consortium came together in 1993 to provide global standardization, interoperability and future proof
specifications.

National transposition dates
Date of adoption of this EN: 22 October 2018
Date of latest announcement of this EN (doa): 31 January 2019
Date of latest publication of new National Standard
or endorsement of this EN (dop/e): 31 July 2019
Date of withdrawal of any conflicting National Standard (dow): 31 July 2019
ETSI

---------------------- Page: 6 ----------------------
7 ETSI EN 300 743 V1.6.1 (2018-10)
Modal verbs terminology
In the present document "shall", "shall not", "should", "should not", "may", "need not", "will", "will not", "can" and
"cannot" are to be interpreted as described in clause 3.2 of the ETSI Drafting Rules (Verbal forms for the expression of
provisions).
"must" and "must not" are NOT allowed in ETSI deliverables except when used in direct citation.

ETSI

---------------------- Page: 7 ----------------------
8 ETSI EN 300 743 V1.6.1 (2018-10)
1 Scope
The present document specifies the method by which subtitles, logos and other graphical elements may be coded and
carried in DVB bitstreams. The system applies Colour Look-Up Tables (CLUTs) to define the colours of the graphical
elements. The transport of the coded graphical elements is based on the MPEG-2 Transport Stream described in
ISO/IEC 13818-1 [1].
2 References
2.1 Normative references
References are either specific (identified by date of publication and/or edition number or version number) or
non-specific. For specific references, only the cited version applies. For non-specific references, the latest version of the
referenced document (including any amendments) applies.
Referenced documents which are not found to be publicly available in the expected location might be found at
https://docbox.etsi.org/Reference/.
NOTE: While any hyperlinks included in this clause were valid at the time of publication ETSI cannot guarantee
their long term validity.
The following referenced documents are necessary for the application of the present document.
[1] ISO/IEC 13818-1: "Information technology - Generic coding of moving pictures and associated
audio information. Part 1: Systems".
[2] ETSI EN 300 468: "Digital Video Broadcasting (DVB); Specification for Service Information (SI)
in DVB systems".
[3] Recommendation ITU-R BT.601: "Studio encoding parameters of digital television for standard
4:3 and wide-screen 16:9 aspect ratios".
[4] Recommendation ITU-R BT.656-4: "Interface for digital component video signals in 525-line and
625-line television systems operating at the 4:2:2 level of Recommendation ITU-R BT.601
(Part A)".
[5] ETSI EN 300 743 (V1.2.1): "Digital Video Broadcasting (DVB); Subtitling systems".
[6] ETSI EN 300 743 (V1.3.1): "Digital Video Broadcasting (DVB); Subtitling systems".
[7] ETSI EN 300 743 (V1.4.1): "Digital Video Broadcasting (DVB); Subtitling systems".
[8] ETSI EN 300 743 (V1.5.1): "Digital Video Broadcasting (DVB); Subtitling systems".
[9] ETSI TS 101 154: "Digital Video Broadcasting (DVB); Specification for the use of Video and
Audio Coding in Broadcasting Applications based on the MPEG-2 Transport Stream".
[10] Recommendation ITU-R BT.709: "Parameter values for the HDTV standards for production and
international programme exchange".
[11] Recommendation ITU-R BT.2020-2: "Parameter values for ultra-high definition television systems
for production and international programme exchange".
[12] Recommendation ITU-R BT.2100-1: "Image parameter values for high dynamic range television
for use in production and international programme exchange".
[13] Recommendation ITU-R BT.1886: "Reference electro-optical transfer function for flat panel
displays used in HDTV studio production".
[14] IETF RFC 1950: "ZLIB Compressed Data Format Specification", (Version 3.3).
[15] IETF RFC 1951: "DEFLATE Comp
...

Draft ETSI EN 300 743 V1.6.1 (2018-07)






EUROPEAN STANDARD
Digital Video Broadcasting (DVB);
Subtitling systems

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2 Draft ETSI EN 300 743 V1.6.1 (2018-07)



Reference
REN/JTC-DVB-378
Keywords
broadcasting, digital, DVB, TV, video
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ETSI

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3 Draft ETSI EN 300 743 V1.6.1 (2018-07)
Contents
Intellectual Property Rights . 6
Foreword . 6
Modal verbs terminology . 7
1 Scope . 8
2 References . 8
2.1 Normative references . 8
2.2 Informative references . 9
3 Definitions and abbreviations . 9
3.1 Definitions . 9
3.2 Abbreviations . 10
4 Introduction to the DVB subtitling system (informative) . 12
4.1 General . 12
4.2 Subtitling system evolution and service compatibility . 12
4.2.1 Introduction. 12
4.2.2 V1.1.1 and V1.2.1 . 12
4.2.3 V1.3.1 . 13
4.2.4 V1.4.1 and V1.5.1 . 13
4.2.5 V1.6.1 . 13
4.2.6 General subtitle service compatibility issues . 14
4.3 Basic concepts and terminology . 14
4.4 Subtitle stream composition . 15
4.5 Subtitle segment coding . 16
4.6 Subtitle stream transport . 17
4.7 Subtitling data hierarchy . 19
4.8 Temporal hierarchy and terminology . 19
5 Subtitle decoder model and subtitle stream provision . 20
5.0 Introduction . 20
5.1 General principles. 21
5.1.0 The subtitle epoch . 21
5.1.1 Subtitle service acquisition . 21
5.1.2 Presentation Time Stamps (PTS) . 21
5.1.3 Usage of the display definition segment . 22
5.1.4 Page composition . 22
5.1.5 Region composition . 22
5.1.6 Points to note . 23
5.2 Buffer memory model . 23
5.2.0 General . 23
5.2.1 Pixel buffer memory . 24
5.2.2 Region memory . 24
5.2.3 Composition buffer memory . 24
5.3 Cumulative display construction . 24
5.4 Decoder rendering bandwidth model . 24
5.4.0 General . 24
5.4.1 Page erasure . 25
5.4.2 Region move or change in visibility . 25
5.4.3 Region fill . 25
5.4.4 CLUT modification. 25
5.4.5 Graphic object decoding . 25
5.4.6 Character object decoding . 26
6 Subtitle stream carriage in the PES layer and in the Transport Stream, and signalling . 26
6.1 General . 26
6.2 Carriage in the PES layer . 26
6.3 Carriage and signalling in the transport stream . 27
ETSI

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4 Draft ETSI EN 300 743 V1.6.1 (2018-07)
7 Subtitling service data specification . 28
7.1 Introduction . 28
7.2 Syntax and semantics of the subtitling segment . 28
7.2.0 General . 28
7.2.0.1 Segment syntax . 28
7.2.0.2 Forward compatibility . 29
7.2.1 Display definition segment . 30
7.2.2 Page composition segment . 32
7.2.3 Region composition segment . 33
7.2.4 CLUT definition segment . 36
7.2.5 Object data segment . 38
7.2.5.0 General . 38
7.2.5.1 Pixel-data sub-block . 41
7.2.5.2 Syntax and semantics of the pixel code strings . 42
7.2.5.2.1 2-bits per pixel code . 42
7.2.5.2.2 4-bits per pixel code . 43
7.2.5.2.3 8-bits per pixel code . 44
7.2.5.3 Progressive pixel block . 45
7.2.6 End of display set segment . 46
7.2.7 Disparity Signalling Segment . 46
7.2.8 Alternative CLUT segment . 52
7.3 Interoperability points . 54
8 Requirements for the subtitling data . 55
8.0 General . 55
8.1 Scope of Identifiers . 55
8.2 Scope of dependencies . 55
8.2.1 Composition page . 55
8.2.2 Ancillary page . 55
8.3 Order of delivery . 56
8.4 Positioning of regions and objects . 56
8.4.1 Regions . 56
8.4.2 Objects sharing a PTS . 56
8.4.3 Objects added to a region . 56
9 Translation to colour components . 56
9.0 General . 56
9.1 4- to 2-bit reduction . 57
9.2 8- to 2-bit reduction . 57
9.3 8- to 4-bit reduction . 58
10 Default CLUTs and map-tables contents . 58
10.0 General . 58
10.1 256-entry CLUT default contents . 58
10.2 16-entry CLUT default contents . 59
10.3 4-entry CLUT default contents . 60
10.4 2_to_4-bit_map-table default contents . 60
10.5 2_to_8-bit_map-table default contents . 61
10.6 4_to_8-bit_map-table default contents . 61
11 Structure of the pixel code strings (informative) . 62
12 Subtitle rendering issues . 63
12.1 Introduction . 63
12.2 Spatial scaling of subtitles . 63
12.3 Rendering subtitles over video with a different colour system . 63
Annex A (informative): How the DVB subtitling system works . 65
A.0 Introduction . 65
A.1 Data hierarchy and terminology . 65
A.2 Temporal hierarchy and terminology . 65
ETSI

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5 Draft ETSI EN 300 743 V1.6.1 (2018-07)
A.3 Decoder temporal model . 65
A.4 Decoder display technology model . 65
A.4.1 Region based with indexed colours . 65
A.4.2 Colour quantization . 66
A.5 Examples of the subtitling system in operation . 66
A.5.1 Double buffering . 66
A.5.1.0 General . 66
A.5.1.1 Instant graphics . 66
A.5.1.2 Stenographic subtitles . 69
Annex B (informative): Use of the DDS for SDTV, HDTV and UHDTV services . 72
B.1 Introduction . 72
B.2 SDTV services . 72
B.3 HDTV services . 72
B.4 UHDTV services . 73
Annex C (informative): Illustration of the application of the disparity_shift_update_sequence
mechanism for 3D content . 74
Annex D (informative): Guidelines on the use of ETSI EN 300 743 for 3D content . 78
Annex E (informative): Conversion of PNG files into progressively coded bitmap subtitles . 82
Annex F (informative): Bibliography . 84
History . 85

ETSI

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6 Draft ETSI EN 300 743 V1.6.1 (2018-07)
Intellectual Property Rights
Essential patents
IPRs essential or potentially essential to normative deliverables 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
server (https://ipr.etsi.org/).
Pursuant to the ETSI IPR Policy, no investigation, including IPR searches, has been carried out by ETSI. No guarantee
can be given as to the existence of other IPRs not referenced in ETSI SR 000 314 (or the updates on the ETSI Web
server) which are, or may be, or may become, essential to the present document.
Trademarks
The present document may include trademarks and/or tradenames which are asserted and/or registered by their owners.
ETSI claims no ownership of these except for any which are indicated as being the property of ETSI, and conveys no
right to use or reproduce any trademark and/or tradename. Mention of those trademarks in the present document does
not constitute an endorsement by ETSI of products, services or organizations associated with those trademarks.
Foreword
This draft European Standard (EN) 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), and is now submitted for the combined Public Enquiry and Vote phase
of the ETSI standards EN Approval Procedure.
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]

The Digital Video Broadcasting Project (DVB) is an industry-led consortium of broadcasters, manufacturers, network
operators, software developers, regulatory bodies, content owners and others committed to designing global standards
for the delivery of digital television and data services. DVB fosters market driven solutions that meet the needs and
economic circumstances of broadcast industry stakeholders and consumers. DVB standards cover all aspects of digital
television from transmission through interfacing, conditional access and interactivity for digital video, audio and data.
The consortium came together in 1993 to provide global standardization, interoperability and future proof
specifications.

Proposed national transposition dates
Date of latest announcement of this EN (doa): 3 months after ETSI publication
Date of latest publication of new National Standard
or endorsement of this EN (dop/e): 6 months after doa
Date of withdrawal of any conflicting National Standard (dow): 6 months after doa

ETSI

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7 Draft ETSI EN 300 743 V1.6.1 (2018-07)
Modal verbs terminology
In the present document "shall", "shall not", "should", "should not", "may", "need not", "will", "will not", "can" and
"cannot" are to be interpreted as described in clause 3.2 of the ETSI Drafting Rules (Verbal forms for the expression of
provisions).
"must" and "must not" are NOT allowed in ETSI deliverables except when used in direct citation.

ETSI

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8 Draft ETSI EN 300 743 V1.6.1 (2018-07)
1 Scope
The present document specifies the method by which subtitles, logos and other graphical elements may be coded and
carried in DVB bitstreams. The system applies Colour Look-Up Tables (CLUTs) to define the colours of the graphical
elements. The transport of the coded graphical elements is based on the MPEG-2 Transport Stream described in
ISO/IEC 13818-1 [1].
2 References
2.1 Normative references
References are either specific (identified by date of publication and/or edition number or version number) or
non-specific. For specific references, only the cited version applies. For non-specific references, the latest version of the
referenced document (including any amendments) applies.
Referenced documents which are not found to be publicly available in the expected location might be found at
https://docbox.etsi.org/Reference/.
NOTE: While any hyperlinks included in this clause were valid at the time of publication ETSI cannot guarantee
their long term validity.
The following referenced documents are necessary for the application of the present document.
[1] ISO/IEC 13818-1: "Information technology - Generic coding of moving pictures and associated
audio information. Part 1: Systems".
[2] ETSI EN 300 468: "Digital Video Broadcasting (DVB); Specification for Service Information (SI)
in DVB systems".
[3] Recommendation ITU-R BT.601: "Studio encoding parameters of digital television for standard
4:3 and wide-screen 16:9 aspect ratios".
[4] Recommendation ITU-R BT.656-4: "Interface for digital component video signals in 525-line and
625-line television systems operating at the 4:2:2 level of Recommendation ITU-R BT.601
(Part A)".
[5] ETSI EN 300 743 (V1.2.1): "Digital Video Broadcasting (DVB); Subtitling systems".
[6] ETSI EN 300 743 (V1.3.1): "Digital Video Broadcasting (DVB); Subtitling systems".
[7] ETSI EN 300 743 (V1.4.1): "Digital Video Broadcasting (DVB); Subtitling systems".
[8] ETSI EN 300 743 (V1.5.1): "Digital Video Broadcasting (DVB); Subtitling systems".
[9] ETSI TS 101 154: "Digital Video Broadcasting (DVB); Specification for the use of Video and
Audio Coding in Broadcasting Applications based on the MPEG-2 Transport Stream".
[10] Recommendation ITU-R BT.709: "Parameter values for the HDTV standards for production and
international programme exchange".
[11] Recommendation ITU-R BT.2020-2: "Parameter values for ultra-high definition television systems
for production and international programme exchange".
[12] Recommendation ITU-R BT.2100-1: "Image parameter values for high dynamic range television
for use in production and international programme exchange".
[13] Recommendation ITU-R BT.1886: "Reference electro-optical transfer function for flat panel
displays used in HDTV studio production".
[
...