1、BRITISH STANDARD BS ISO/IEC 13522-6:1998 Information technology Coding of multimedia and hypermedia information Part 6: Support for enhanced interactive applications ICS 35.040; 35.240.99BSISO/IEC13522-6:1998 This British Standard, having been prepared under the directionof the DISC Board, waspublis
2、hed under the authorityof the Standards Committee and comes into effect on 15 December 1998 BSI 07-1999 ISBN 0 580 30788 3 National foreword This British Standard reproduces verbatim ISO/IEC 13522-6:1998 and implements it as the UK national standard. The UK participation in its preparation was entru
3、sted to Technical Committee IST/37, Coding of picture, audio, multimedia and hypermedia information, which has the responsibility to: aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and ke
4、ep the UK interests informed; monitor related international and European developments and promulgate them in the UK. 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 pub
5、lications referred to in this document may be found in the BSI Standards Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Find” facility of the BSI Standards Electronic Catalogue. A British Standard does not purport to include all the necessary pr
6、ovisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, theISO/IEC ti
7、tle page, pages ii to vi, pages 1 to 86 and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. Amendments issued since publication Amd. No. Date CommentsBSISO/IEC13522-6:
8、1998 BSI 07-1999 i Contents Page National foreword Inside front cover Foreword v Text of ISO/IEC 13522-6 1ii blankBSISO/IEC13522-6:1998 ii BSI 07-1999 Contents Page Foreword v 1 Scope 1 1.1 Context of the scope 1 1.2 Scope of this part of ISO/IEC 13522 1 2 Normative references 2 2.1 International st
9、andards 2 2.2 Referenced specifications 2 3 Terms and definitions 2 3.1 applet 2 3.2 application class 2 3.3 application programming interface (API) 2 3.4 attribute 2 3.5 class 3 3.6 exception 3 3.7 hypermedia, adj 3 3.8 instance 3 3.9 interface 3 3.10 Java Virtual Machine (JVM) 3 3.11 method 3 3.12
10、 MHEG-5 API 3 3.13 MHEG-5 InterchangedProgram object 3 3.14 MHEG-5 object 3 3.15 MHEG-6, adj 3 3.16 MHEG-6 Applet object 4 3.17 MHEG-6 application 4 3.18 MHEG-6 engine 4 3.19 MHEG-6 InterchangedProgram object 4 3.20 MHEG-6 object 4 3.21 MHEG-6 profile 4 3.22 MHEG-6 program 4 3.23 multimedia, adj 4 3
11、.24 multimedia and hypermedia application 4 3.25 multimedia application 4 3.26 operation 4 3.27 program 4 3.28 Program content interchange format 4 3.29 scripting language 5 3.30 stack 5 3.31 system class 5 3.32 virtual machine (VM) 5 4 Symbols and abbreviations 5 5 Conformance requirements 5 5.1 In
12、formation object conformance 5 5.1.1 Encoding and syntax 5 5.1.2 Semantics 5 5.1.3 Profiles 6 5.2 Implementation conformance 6 5.2.1 Conformance requirements 6 5.2.2 Conformance documentation 6 5.3 Application conformance 6BSISO/IEC13522-6:1998 BSI 07-1999 iii Page 6 Structure of this part of ISO/IE
13、C 13522 7 7 MHEG-6 InterchangedProgram class 7 7.1 InterchangedProgram object syntax 7 7.1.1 Syntax of InterchangedProgram class 7 7.1.1.1 Name attribute 7 7.1.1.2 OriginalContent attribute 7 7.1.1.3 ContentHook attribute 8 7.1.1.4 Shared attribute 8 7.1.2 Syntax of elementary actions applicable to
14、InterchangedProgram objects 8 7.2 InterchangedProgram object semantics 8 7.2.1 InitiallyAvailable attribute 8 7.2.2 Scope of InterchangedProgram objects 8 7.2.3 Effect of elementary actions applicable to InterchangedProgram objects 8 7.2.3.1 Preparation behaviour 8 7.2.3.2 Activation behaviour 9 7.2
15、.3.3 Deactivation behaviour 10 7.2.3.4 Destruction behaviour 10 8 Applet class 10 8.1 Attributes 10 8.1.1 Inherited attributes 10 8.1.2 Own exchanged attributes 11 8.1.3 Own internal MHEG-5 attributes 11 8.2 Events 11 8.3 Internal behaviours 11 8.4 Effect of MHEG-5 elementary actions 12 8.5 Formal d
16、escription 14 9 Virtual machine 14 9.1 VM instruction set 14 9.2 VM interchange format 14 10 Kernel API 14 10.1 Specification of the kernel API 14 10.2 Syntax requirement 15 10.3 Semantics requirement 15 10.4 Pragmatics requirement 15 11 MHEG-5 API 15 11.1 Specification of the MHEG-5 API 15 11.1.1 D
17、esign principles 15 11.1.2 Grades 15 11.2 Syntax requirement 16 11.3 Semantics requirement 16 11.4 Pragmatics requirement 16 11.5 Interworking considerations 16 12 MHEG-5/JVM interworking provisions 17 12.1 Program content interchange format 17 12.2 Semantics of elementary actions 17 12.2.1 Call 17B
18、SISO/IEC13522-6:1998 iv BSI 07-1999 Page 12.2.2 Fork 17 12.2.3 Invoke 18 12.2.4 Stop 18 12.2.5 MHEG-5 API operations 18 12.3 Execution semantics 18 12.3.1 Engine bootstrapping 18 12.3.2 ClassMapper initialisation 18 12.3.3 Program preparation 19 12.3.4 Program activation 19 12.3.5 Program deactivati
19、on 19 12.3.6 Program destruction 20 12.3.7 ClassMapper for Applet 20 Annex A (normative) ASN.1 notation 21 Annex B (normative) Textual notation 44 Annex C (normative) MHEG-5 API 62 Annex D (informative) Mapping elementary actions to MHEG-5 API operations 78 Annex E (informative) Relationships betwee
20、n MHEG-6 Applets and World Wide Web applets 82 Annex F (informative) Main features 83 Annex G (informative) IPR issues 86 Table 1 Mapping of MHEG-5 parameter types to JVM types 9 Table B.1 definitions of Symbols in Textual Notation 44 Table B.2 Tag abbreviations 46 Table D.1 Mapping elementary to MH
21、EG-5 API operations 78BSISO/IEC 13522-6:1998 BSI 07-1999 v Foreword ISO (the International Organization for Standardization) and IEC (the International Electrotechnical Commission) form the specialised system for worldwide standardisation. National bodies that are members of ISO or IEC participate i
22、n the development of International Standards through technical committees established by the respective organisation to deal with particular fields of technical activity. ISO and IEC technical committees collaborate in fields of mutual interest. Other international organisations, governmental and no
23、n-governmental, in liaison with ISO and IEC, also take part in the work. In the field of Information technology, ISO and IEC have established a joint technical committee, ISO/IECJTC1. Draft International Standards adopted by the joint technical committee are circulated to national bodies for voting.
24、 Publication as an International Standard requires approval by at least75% of the national bodies casting a vote. International Standard ISO/IEC13522-6 was prepared by Joint Technical Committee ISO/IECJTC1, Information technology, Subcommittee SC29, Coding of audio, picture, multimedia and hypermedi
25、a information. ISO/IEC13522 consists of the following parts, under the general title Information technology Coding of multimedia and hypermedia information: Part 1: MHEG object representation Base notation (ASN.1); Part 3: MHEG script interchange representation; Part 4: MHEG registration procedure;
26、Part 5: Support for base-level interactive applications; Part 6: Support for enhanced interactive applications; Part 7: Interoperability and conformance testing for ISO/IEC13522-5. Annex A toAnnex C form an integral part of this part of ISO/IEC13522. Annex D toAnnex G are for information only.vi bla
27、nkBSISO/IEC13522-6:1998 BSI 07-1999 1 1 Scope 1.1 Context of the scope ISO/IEC 13522 specifies the coded representation of multimedia/hypermedia information objects (MHEG objects) for interchange as final form units within or across services and applications, by any means of interchange including lo
28、cal area networks, wide area telecommunication or broadcast networks, storage media, etc. MHEG objects can be produced by computer tools taking as source form multimedia applications designed using multimedia scripting languages. In this context, the MHEG script (or program) classes are intended to
29、complement the other MHEG classes in expressing the functionality commonly supported by scripting languages. Script (or program) objects express more powerful control mechanisms and describe more complex relationships among MHEG objects than can be expressed by MHEG action and link objects alone. Fu
30、rthermore, script (or program) objects express access to and interaction with external services provided by the run-time environment. ISO/IEC13522-5 defines the MHEG object classes for interchange and use in base-level applications intended to be run on limited resource terminals such as set-top-box
31、es in such contexts as interactive broadband services. ISO/IEC13522-5 defines the coded representation for program objects in an open manner so that program objects may encapsulate either standardised or proprietary program code. ISO/IEC13522-5 allows program objects to include or reference programs
32、 that may be encoded in any encoding format as defined by the application domain. 1.2 Scope of this part of ISO/IEC 13522 The scope of this part of ISO/IEC13522 is to define the semantics and final-form coded representation for the interchange of enhanced interactive multimedia applications. These a
33、pplications extend applications covered by ISO/IEC13522-5 in incorporating functionality such as computing (data processing) and extended communication with the external environment, including servers, local devices, etc. These applications may be exploited in any communication environment including
34、 broadcast-only mode, interactive client-server or peer-to-peer (conversational). However, the main focus is on interactive retrieval (client-server) applications running on limited resource set-top-units involving asymmetrical data interchange with real-time audiovisuals on the downstream channel.
35、The coded representation defined by this part of ISO/IEC13522 specialises the coded representation defined by ISO/IEC13522-5. Especially, this part of ISO/IEC13522 defines the coded representation for the OriginalContent attribute of the MHEG-5 InterchangedProgram class. In addition, this part of IS
36、O/IEC13522 defines the Applet class; this subclass of InterchangedProgram features the ability to manage its own display and interaction, by delegation from the engine. The resulting coded representation is compatible with that defined by ISO/IEC 13522-5; appropriate for execution on a set-top-unit
37、with the same minimal resource constraints as expressed by ISO/IEC13522-5. This part of ISO/IEC 13522 specifies the interchange format for the OriginalContent attribute of the MHEG-5 InterchangedProgram class; the semantics of this coded representation; the coded representation and semantics of the
38、Applet class; the semantic extensions to the MHEG-5 engine behaviour described by ISO/IEC13522-5; the semantic restrictions on the MHEG-5 interchange format described by ISO/IEC13522-5; the MHEG-5 API, which allows the code of an InterchangedProgram object to call upon the MHEG-5 engines presentatio
39、n functionality; the provisions for interworking between the MHEG-5 engine execution model and the execution model that underlies the program content interchange format.BSISO/IEC13522-6:1998 2 BSI 07-1999 MHEG engines are system or application components that handle, interpret and present MHEG objec
40、ts. This part of ISO/IEC13522 specifies the semantics of the MHEG-6 coded representation. These semantics are defined in terms of minimum requirements on the behaviour of MHEG-6 engines. This part of ISO/IEC13522 is applicable to all applications that interchange multimedia and hypermedia informatio
41、n. 2 Normative references 2.1 International standards The following standards contain provisions which, through reference in this text, constitute provisions of this part of ISO/IEC13522. At the time of publication, the editions indicated were valid. All standards are subject to revision, and partie
42、s to agreements based on this part of ISO/IEC13522 are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. Members of ISO and IEC maintain registers of currently valid International Standards. ISO/IEC 646:1991, Information technology ISO 7
43、-bit coded character set for information interchange. ISO/IEC 8824-1:1995, Information technology Abstract Syntax Notation One (ASN.1): Specification of basic notation. ISO/IEC 8825-1:1995, Information technology ASN.1 encoding rules: Specification of Basic Encoding Rules (BER), Canonical Encoding R
44、ules (CER) and Distinguished Encoding Rules (DER). ISO/IEC 10646-1:1993, Information technology Universal Multiple-Octet Coded Character Set (UCS) Part 1: Architecture and Basic Multilingual Plane. ISO/IEC 13522-5:1997, Information technology Coding of multimedia and hypermedia information Part 5: S
45、upport for base-level interactive applications. 2.2 Referenced specifications All references in this subclause were correct at the time of approval of this part of ISO/IEC13522. The provisions of the referenced specifications, as identified in this subclause, are valid within the context of this par
46、t of ISO/IEC13522. The reference to a specification within this part of ISO/IEC13522 does not give it any further status within ISO/IEC; in particular, it does not give the referenced specification the status of an International Standard. Lindholm, Tim and Yellin, Frank (September 1996), The Java Vi
47、rtual machine specification. ISBN: 0-201-63452-X, Addison-Wesley Publishing Co.: Reading, Massachussets. Gosling, James, Yellin, Frank and the Java team (May 1996), The Java Application Programming Interface, Volume 1: Core Packages. ISBN:0-201-63453-8, Addison-Wesley Publishing Co.: Reading, Massac
48、hussets. 3 Terms and definitions For the purposes of this part of ISO/IEC13522, the terms and definitions given in ISO/IEC13522-5 and the following terms and definitions apply. 3.1 applet autonomous program that can be run only within a host framework 3.2 application class JVM class entirely impleme
49、nted in JVM code and interchanged as part of an MHEG-6 application 3.3 application programming interface (API) boundary across which a software application uses facilities of programming languages to invoke software services 3.4 attribute named, typed association between an object and a value, declared as part of the interface of a class: a) MHEG-5 attribute (see ISO/IEC 13522-5);BSISO/IEC13522-6:1998 BSI 07-1999 3 b) attribute of a JVM class (see 2.2) 3.5 class abstract definition of the data (attributes)
