1、BRITISH STANDARD BS EN 62297-1:2005 Triggering messages for broadcast applications Part 1: Format The European Standard EN 62297-1:2005 has the status of a British Standard ICS 33.170 BS EN 62297-1:2005 This British Standard was published under the authority of the Standards Policy and Strategy Comm
2、ittee on 5 December 2005 BSI 5 December 2005 ISBN 0 580 46331 1 National foreword This British Standard is the official English language version of EN 62297-1:2005. It is identical with IEC 62297-1:2005. The UK participation in its preparation was entrusted to Technical Committee EPL/100, Audio, vid
3、eo and multimedia systems and equipment, which has the responsibility to: A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references The British Standards which implement international or European publications referred to in this document may
4、be found in the BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by using 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 ar
5、e responsible for its correct application. Compliance with a British Standard does not of itself confer immunity from 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
6、 keep UK interests informed; monitor related international and European developments and promulgate them in the UK. Summary of pages This document comprises a front cover, an inside front cover, the EN title page, pages 2 to 24, an inside back cover and a back cover. The BSI copyright notice display
7、ed in this document indicates when the document was last issued. Amendments issued since publication Amd. No. Date CommentsEUROPEAN STANDARD EN 62297-1 NORME EUROPENNE EUROPISCHE NORM June 2005 CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotech
8、nique Europisches Komitee fr Elektrotechnische Normung Central Secretariat: rue de Stassart 35, B - 1050 Brussels 2005 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members. Ref. No. EN 62297-1:2005 E ICS 33.170 English version Triggering messages f
9、or broadcast applications Part 1: Format (IEC 62297-1:2005) Messages de dclenchement pour les applications de radiodiffusion Partie 1: Format (CEI 62297-1:2005) Triggernachrichten fr Rundfunkanwendungen Teil 1: Format (IEC 62297-1:2005) This European Standard was approved by CENELEC on 2005-05-01. C
10、ENELEC 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 standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained o
11、n 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 other language made by translation under the responsibility of a CENELEC member into its own language and notified to the Central Se
12、cretariat has the same status as the official versions. CENELEC members are the national electrotechnical committees of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, N
13、orway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EN 62297-1:2005 2 Foreword The text of document 100/910/FDIS, future edition 1 of IEC 62297-1, prepared by IEC TC 100, Audio, video and multimedia systems and equipment, was submitted to the IEC-CENELEC paral
14、lel vote and was approved by CENELEC as EN 62297-1 on 2005-05-01. The following dates were fixed: latest date by which the EN has to be implemented at national level by publication of an identical national standard or by endorsement (dop) 2006-02-01 latest date by which the national standards confli
15、cting with the EN have to be withdrawn (dow) 2008-05-01 Annex ZA has been added by CENELEC. _ Endorsement notice The text of the International Standard IEC 62297-1:2005 was approved by CENELEC as a European Standard without any modification. _ 3 EN 62297-1:2005 CONTENTS INTRODUCTION4 1 Scope 7 2 Nor
16、mative references .7 3 Terms, definitions and abbreviations.7 3.1 Definitions.7 3.2 Abbreviations 9 4 Trigger message 10 4.1 General.10 4.1.1 Viewer interaction 10 4.1.2 Priority ratings .10 4.1.3 Character coding .10 4.1.4 Future compatibility10 4.2 Life cycles.10 4.2.1 Trigger message and event me
17、ssage life cycle .10 4.2.2 Event message preparation life cycle11 4.2.3 Application life cycle 12 4.3 Syntax of trigger message 14 4.3.1 General .14 4.3.2 Trigger text length14 4.3.3 Syntax of trigger text14 4.3.4 Trigger repetition .18 Annex A (informative) Recommendations .19 Annex B (informative)
18、 Code of practice 20 B.1 Time reference 20 B.2 Modifying triggers20 B.3 Trigger expiry 20 B.4 Countdown values .20 B.5 Initial state 20 B.6 Multiple sources 20 B.7 Receivers not supporting concurrent ApplicationObject instances .21 B.8 Receivers supporting concurrent ApplicationObject instances.21 B
19、.9 The ICON bitmap.21 B.10 The use of priority22 B.11 Interaction of name and script attributes.22 B.12 Supporting multiple applications.22 B.13 Supporting multiple transport layers .22 B.14 Who is in control22 Annex ZA (normative) Normative references to international publications with their corres
20、ponding European publications23 Bibliography24 Figure 1 Trigger messages and event messages life cycle 11 Figure 2 TriggerObject life cycle.12 Figure 3 ApplicationObject life cycle.13 Figure B.1 Icon bitmap tailored for a display with a resolution of 640 by 480 .21 EN 62297-1:2005 4 Table 1 Syntax o
21、f trigger_message 14 Table 2 Syntax of trigger_text 14 5 EN 62297-1:2005 INTRODUCTION Emerging data broadcasting specifications allow a service provider to trigger an application in a TV receiver. This International Standard specifies the format of a triggering message for TV broadcasting as based o
22、n the requirements defined in Annex A. Examples of possible use include displaying information to warn for severe weather conditions or to give rating advice for extreme content in TV programmes. In an interactive system, a message or icon might be displayed inviting on-line access to vote, to regis
23、ter an interest in an advertised product, or to browse programme-related content. This standard describes a trigger mechanism for teletext transmission methods. The trigger mechanism can also be used for services broadcast via MPEG-2 DSM-CC sections. For the purposes of this standard, a trigger is d
24、efined as information sent from a service provider as part of a data broadcasting transmission and intended to control an application in a TV receiver. Additional information can be supplied along with the basic trigger to allow filtering or prioritization techniques to be applied at the receiver. T
25、he transmission aspects of trigger messages are specified in IEC 62297-2. This trigger mechanism is very similar to the one defined in IEC/PAS 62292. The difference lies primarily in different state models, semantics and attribute names. blank 7 EN 62297-1:2005 TRIGGERING MESSAGES FOR BROADCAST APPL
26、ICATIONS Part 1: Format 1 Scope This part of IEC 62297 specifies an application-triggering scheme for TV broadcasting information sent from a service provider as part of a data broadcasting transmission and intended to control an application in a receiver. 2 Normative references The following refere
27、nced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 8859-1, Information technology 8-bit single-byte coded graphic ch
28、aracter sets Part 1: Latin alphabet No. 1 ETSI TS 101 231, Television systems; Register of Country and Network Identification (CNI), Video Programming System (VPS) codes and Application codes for Teletext based systems ETSI EN 300 706, Enhanced Teletext Specification 3 Terms, definitions and abbrevi
29、ations 3.1 Definitions For the purposes of this document, the following terms and definitions, in singular or plural form, apply. 3.1.1 ActiveTimeValue member of the ApplicationObject. The value decrements at video frame rate. It is updated on every reception of an event message. 3.1.2 Application s
30、oftware running on a receiver that is addressed by the URL of a trigger message and providing the following modes of operation: a) the display of information, the playback of sound, the download of data; b) the initiation of any action. Application examples include the display of a simple text messa
31、ge sent as part of the trigger message, the display of a Teletext, Superteletext (TeleWeb Tw) or Internet page, information from an Electronic Programme Guide (EPG), electronic voting, an emergency alert 3.1.3 ApplicationObject object storing the information about an application started or modified
32、by triggers referencing the same URL EN 62297-1:2005 8 3.1.4 Attribute member of an ApplicationObject or TriggerObject storing the information transported via an attribute element 3.1.5 attribute element attribute name/value pair 3.1.6 attribute string any sequence of characters with codes in the ra
33、nge 020 to 07E inclusive, excluding square brackets (05B and 05D) 3.1.7 charset abbreviation for character set 3.1.8 CountdownValue member of a TriggerObject. The value decrements at video frame rate. It is updated on every reception of a trigger mes 3.1.9 DateTime date and time instance of UTC expr
34、essed in the form: yyyymmddThhmmss, where yyyy represents a year, mm represents a month (range 112), dd represents the day of the month (range 131), the capital letter T separates the date component from the time component, hh represents an hour (range 023), mm represents the minutes (range 059) and
35、 ss represents the seconds (range 059) 3.1.10 Dummy URL URL that does not reference any application or data and used in the mandatory URL field of a trigger message when the intention is to display only the trigger icon (together with its text) and not to control an application 3.1.11 event message
36、information extracted from a trigger message that is used to create an ApplicationObject 3.1.12 event start event message with its script attribute element set to start 3.1.13 event stop event message with its script attribute element set to stop 3.1.14 pending trigger state where a trigger message
37、has created a TriggerObject but the conditions to create an ApplicationObject have not yet occurred 3.1.15 priority filtering rejecting a trigger message on account of the value assigned to its priority attribute element 9 EN 62297-1:2005 3.1.16 RelativeTime time period measured in seconds and video
38、 frames 3.1.17 string any sequence of characters with codes in the range 020 to 07E inclusive. Throughout this document strings are not case-sensitive unless otherwise indicated 3.1.18 trigger signal sent from a service provider as part of a data broadcasting transmission with the intention to start
39、 or modify an application at a certain time 3.1.19 trigger character character with a code in the range 020 to 07E inclusive 3.1.20 trigger del trigger message with a delete attribute element 3.1.21 trigger event instant in time when a trigger fires and an event message is created 3.1.22 trigger mes
40、 trigger message without a delete attribute element 3.1.23 trigger message information embedded in a trigger and intended to control an application in a receiver 3.1.24 TriggerObject object storing the information from all the triggers referencing the same URL 3.1.25 trigger_text descriptive part of
41、 a trigger message. 3.1.26 URL string any sequence of characters with codes in the range 020 to 07E inclusive, excluding angular brackets (03C and 03E) 3.2 Abbreviations CNI Country and Network Identification URL Uniform Resource Locator UTC Coordinated Universal Time VPS Video Programming System EN
42、 62297-1:2005 10 4 Trigger message 4.1 General 4.1.1 Viewer interaction The mechanism through which the viewer enables or disables trigger handling or sets priority threshold levels is at the receiver manufacturers discretion. The appearance of an icon and the viewer interaction when responding to i
43、t is also at the receiver manufacturers discretion. 4.1.2 Priority ratings Triggers labelled with the emergency priority rating should always be processed, even if the viewer has disabled trigger handling. The emergency priority shall only be used by service providers for genuine emergency situation
44、s. The set maker is allowed to provide the user with the ability to switch off this emergency priority. 4.1.3 Character coding All characters used to code triggers are taken from the ISO 8859-1 character set and are in the range 020 to 07E inclusive. A character outside this range shall be encoded u
45、sing the per cent character (%) followed by the two-digit hexadecimal value of the character. The % character itself is represented by the string %25. The character is represented by %5B, the character by %5D. The default character coding for all string attribute values is ISO 8859-1. The character
46、coding for the name attribute can be changed with the charset attribute. 4.1.4 Future compatibility To ensure future compatibility, a receiver should ignore data it does not understand, such as attribute elements not defined by this edition. 4.2 Life cycles 4.2.1 Trigger message and event message li
47、fe cycle Figure 1 describes the life-cycle trigger message and an event message referencing the same resource (URL). An incoming trigger message is acquired through the transport layer. The priority filtering process provides the opportunity to reject a trigger message on account of its priority att
48、ribute element. However, it is not recommended to reject a trigger message with its priority attribute element set to 0 (zero) as this value is reserved for emergency trigger messages. The Event message preparation processes the filtered trigger messages and provides robustness to the trigger protocol when carried over a unidirectional transport layer where the reception of the information is not always guaranteed. Each trigger message carries a countdown value indicating the time delay before the trigger should fire. To aid robustness, the trigger message can be transmitted at
