1、BRITISH STANDARDBS EN 62298-3:2005Teleweb application Part 3: Superteletext profile The European Standard EN 62298-3:2005 has the status of a British StandardICS 33.170; 35.240.99g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g
2、54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58BS EN 62298-3:2005This British Standard was published under the authority of the Standards Policy and Strategy Committee on 14 October 2005 BSI 14 October 2005ISBN 0 580 46513 6National forewordThis British Standard is th
3、e official English language version of EN 62298-3:2005. It is identical with IEC 62298-3:2005.The UK participation in its preparation was entrusted to Technical Committee EPL/100, Audio, video and multimedia systems and equipment, which has the responsibility to:A list of organizations represented o
4、n this committee can be obtained on request to its secretary.Cross-referencesThe British Standards which implement international or European publications referred to in this document may be found in the BSI Catalogueunder the section entitled “International Standards Correspondence Index”, or by usi
5、ng the “Search” facility of the BSI Electronic Catalogue or of British Standards Online.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application.Compliance with a British Standard does not of itself confer immunity fro
6、m legal obligations. aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep UK interests informed; monitor related international and European developments and promulgate them in the UK.S
7、ummary of pagesThis document comprises a front cover, an inside front cover, the EN title page, pages 2 to 98, an inside back cover and a back cover.The BSI copyright notice displayed in this document indicates when the document was last issued.Amendments issued since publicationAmd. No. Date Commen
8、tsEUROPEAN STANDARD EN 62298-3NORME EUROPENNE EUROPISCHE NORM June 2005 CENELECEuropean Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Central Secretariat: rue de Stassart 35, B - 1050 Brussels 2005 CENE
9、LEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members. Ref. No. EN 62298-3:2005 E ICS 33.170; 35.240.99 English version Teleweb application Part 3: Superteletext profile (IEC 62298-3:2005)Application Teleweb Partie 3: Profil supertltexte (CEI 62298-3:20
10、05) TeleWeb-Anwendung Teil 3: Superteletext-Profil (IEC 62298-3:2005) This European Standard was approved by CENELEC on 2005-06-01. CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national
11、standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CENELEC member. This European Standard exists in three official versions (English, French, German). A version in any
12、 other language made by translation under the responsibility of a CENELEC member into its own language and notified to the Central Secretariat has the same status as the official versions. CENELEC members are the national electrotechnical committees of Austria, Belgium, Cyprus, Czech Republic, Denma
13、rk, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. 2Foreword The text of document 100/924/FDIS, future edition 1 of IEC 62298-
14、3, prepared by IEC TC 100, Audio, video and multimedia systems and equipment, was submitted to the IEC-CENELEC parallel vote and was approved by CENELEC as EN 62298-3 on 2005-06-01. The following dates were fixed: latest date by which the EN has to be implemented at national level by publication of
15、an identical national standard or by endorsement (dop) 2006-03-01 - latest date by which the national standards conflicting with the EN have to be withdrawn (dow) 2008-06-01 Annex ZA has been added by CENELEC. _ Endorsem ent notice The text of the International Standard IEC 62298-3:2005 was approved
16、 by CENELEC as a European Standard without any modification. _ EN 62298-3:2005 3 CONTENTS INTRODUCTION.51 Scope.62 Normative references .63 Terms, definitions and abbreviations 73.1 Terms and definitions 73.2 Abbreviations 74 Display .84.1 Colour representation84.2 Text representation .94.3 Text pla
17、cement114.4 Image representation 124.5 4:3 and 16:9 aspect ratio displays .125 URLs135.1 File naming .145.2 Access through page number 145.3 TeleWeb file reference scheme .155.4 Teletext page reference scheme175.5 NexTView reference scheme .185.6 Special function URLs .196 Text and hypertext196.1 Te
18、leWeb HTML file format.196.2 Syntax of TeleWeb HTML tags .216.3 Document structure elements 236.4 Header section tags 266.5 Paragraph formatting.286.6 Character formatting316.7 Hypertext links 356.8 Lists 406.9 Tables .436.10 Images 496.11 Ticker text .526.12 Exceptional ignored tags .547 TeleWeb de
19、fault style .548 Image files548.1 GIF548.2 JPEG 559 Content labelling 559.1 Predefined themes and identifier coding559.2 Parental ratings.5510 Special data .5510.1 Service identification graphic.5510.2 Home page5610.3 Default page56EN 62298-3:2005 4 10.4 Profile upgrade page .5610.5 ZLIB dictionary
20、files .5611 Service-related attributes5711.1 Name 5711.2 Information5711.3 Language 5711.4 Transmission schedule 5712 File-related attributes5812.1 General file attributes 5912.2 File content attributes 6012.3 Time- and date-related attributes .6112.4 Storage-related attributes 6212.5 Special functi
21、on attributes6213 Short and full TeleWeb service .6314 Individual addressing Group addressing.64Annex A (informative) HTML compatibility .65Annex B (normative) Default colour palette specification68Annex C (normative) Table of predefined themes 70Annex D (informative) TeleWeb document type definitio
22、n (DTD) 77Annex E (informative) TeleWeb default CSS2 style sheet 86Annex F (normative) Font metrics89Annex G (informative) TeleWeb Superteletext profile reference decoder .94Bibliography .97Annex ZA (normative) Normative references to international publications with theircorresponding European publi
23、cations .98Table 1 Default colour palette 9Table 2 Font sizes .10Table 3 File naming .14Table 4 EPG parameters16Table 5 Profile parameter.17Table 6 Special function URLs .19Table 7 List of service-related attributes .57Table 8 List of file-related attributes .58Table 9 Rating scheme 61Table 10 Filte
24、r attributes for nexTView references 64Table A.1 HTML V3.2 tags not supported .65Table A.2 HTML V3.2 attributes not supported66Table A.3 Browser specific tags supported .66Table A.4 TeleWeb specific tags supported 66Table B.1 Default colour palette specification .68Table C.1 Predefined themes .70EN
25、62298-3:2005 5 INTRODUCTION The aim of TeleWeb is to deliver World Wide Web-style content to the living-room TV to give the viewer an enhanced television experience. A TeleWeb service broadcasts data files containing text and high-definition graphics to suitable decoders. The data transmitted can be
26、 closely linked to events within the accompanying TV programs or can be more general in nature to emulate a traditional, but higher definition, superteletext service. Different profiles are defined. It is intended that TV-based decoders can be implemented in a cost-effective manner without recourse
27、to the technology normally associated with personal computers. In part, this is achieved by limiting the number of different types of multimedia data that can be used within a service. By careful design of the user interface, decoder manufacturers will be able to offer easy-to-use equipment for acce
28、ssing TeleWeb services without requiring the consumer to be computer-literate. In addition, they will be able to customize their products to differentiate them from those of their competitors. This standard specifies the TeleWeb Superteletext profile and focuses on the presentation layer especially
29、the implementation of TeleWeb HTML. It further defines graphical requirements like colours and fonts and the content formats used. EN 62298-3:2005 6 TELEWEB APPLICATION Part 3: Superteletext profile 1 Scope This part of IEC 62298 specifies the TeleWeb Superteletext profile that allows Web-style text
30、 and graphics to be displayed on suitable decoders. A TeleWeb service comprises multimedia data files whose format and attributes are defined by this specification. This specification focuses on the presentation layer especially the implementation of TeleWeb HTML. It further defines graphical requir
31、ements like colours and fonts and the used content formats. For information regarding general information and the transport layer, refer to IEC 62298-1 and IEC 62298-2. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated referen
32、ces, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.IEC 62297-1, Triggering messages for broadcast applications TISO 639-2, Codes for the representation of names and languages Part 2: Alpha-3 code ISO 8601, Dat
33、a elements and interchange formats Information interchange Representation of dates and times ISO 8859-1:1998, Information technology 8-bit single-byte coded graphic character sets Part 1: Latin alphabet No. 1 ETSI TR 101 231, Television systems; Register of Country and Network Identification (CNI),
34、Video Programming System (VPS) codes and Application codes for Teletext based systems ETSI EN 300 231, Television systems; Specification of the domestic video Program Delivery Control (PDC) system ETSI EN 300 468, Digital Video Broadcasting (DVB); Specification for Service Information (SI) in DVB sy
35、stems ETSI EN 300 706, Enhanced Teletext SpecificationETSI EN 300 707, Electronic Program Guide (EPG); Protocol for a TV Guide using electronic data transmissionEN 62298-3:2005 7 3 Terms, definitions and abbreviations 3.1 Terms and definitions For the purposes of this document, the following terms a
36、nd definitions apply. 3.1.1 buttonpart of the user interface that enables the viewer to select a page or trigger an event, etc. It may not necessarily exist as a physical button on a remote control handset 3.1.2 CDATA character data in an HTML document. Character entities and HTML mark-up is not rec
37、ognized 3.1.3 conditional access (CA) mechanism by which user access to service components can be restricted 3.1.4 PCDATA Parsed character data in an HTML document. Character entities (numeric and named entities) as well as HTML mark-up are recognized in the data 3.1.5 signed_integer positive or neg
38、ative integer value, in decimal notation. The first digit is preceded by a mandatory plus (+) or minus () symbol with no white space between the symbol and the first digit 3.1.6 text_string sequence of displayable Latin-1 characters 3.1.7 unsigned_integer integer value, in decimal notation, without
39、a preceding plus (+) or minus (-) symbol3.2 Abbreviations ASCII American Standard Code for Information Interchange CA Conditional Access CDATA Character Data CRC Cyclic Redundancy Check DTD Document Type Definition DVB Digital Video Broadcasting ETS European Telecommunication Standard GIF Graphics I
40、nterchange Format HTML Hyper Text Mark-up Language JFIF JPEG File Interchange Format JPEG Joint Picture Experts Group LSB Least Significant Bit EN 62298-3:2005 8 MJD Modified Julian Date MSB Most Significant Bit PCDATA Parsed Character Data between tags RFC Request For Comments URL Uniform Resource
41、Locator UTC Universal Time Coordinated WWW World Wide Web 4 Display This clause defines the minimum requirements of a TeleWeb display. They are applicable to both editing stations and decoders. 4.1 Colour representation 4.1.1 General requirements A decoder shall be able to display each pixel on the
42、text/graphics, background image and background colour planes in a different colour from a palette of at least 188 colours. Full transparency and one-level semi-transparency to video shall also be supported. A decoder may be implemented with either a true-colour store or an indexed colour system. To
43、accommodate the latter type of decoder and to define a palette for GIF images that do not specify a palette themselves, a single 188 colour palette is defined in 4.1.5. As a minimum, the text/graphics, background image and background colour planes shall be able to support colours subjectively equiva
44、lent to these colours. Content can be authored using other colours, but authors should be aware that some decoders may not be able to reproduce them exactly and may map such a colour to the closest match in the pre-defined colour palette. For authoring purposes the text/graphics, background image an
45、d background colour planes shall support at least 188 colours on the screen at any one time. In practical terms, a decoder is likely to be able to display at least 256 colours, giving the equipment manufacturers at least 68 colours for their user interface. To get an optimal display, the content sho
46、uld be authored using the TeleWeb default colour palette. The response of a decoder is not defined by this specification if the colours used are not all taken from the pre-defined colour palette. Under these circumstances, colour dithering or matching techniques may need to be applied and the respon
47、se of decoders may differ. 4.1.2 Colour resolution Each colour shall be defined by red, green and blue (RGB) components or by a colour constant (see 6.2.5.1). The authored content shall define colours as 24-bit values, i.e. 8 bits for each component in the order R, G, B. A decoder is required to hav
48、e a colour resolution of at least 4 bits per component (12 bits minimum overall). 4.1.3 Gamma Decoders shall assume that all RGB values defined and invoked by authored content have been gamma pre-corrected for the eye. EN 62298-3:2005 9 4.1.4 Transparency Decoders are required to implement a minimum
49、 of three levels of transparency opaque, semi-transparency and completely transparent. The colour palette is optimized for 30 % semi-transparency. Where the decoder cannot implement the value of 30 % semi-transparency, it shall replace it with the nearest value of semi-transparency it can implement. If the encoded value of transparency is in the range between 10 % and 90 %, it shall not be approximated as either 0 % or 100 % transparency. So, 9 % may be approximated as 0 % but
