1、BRITISH STANDARD BS ISO/IEC 14478-1:1998 Information technology Computer graphics and image processing Presentation Environment for Multimedia Objects (PREMO) Part 1: Fundamentals of PREMO ICS 33.160.60; 35.140BSISO/IEC 14478-1:1998 This British Standard, having been prepared under the directionof t
2、he DISC Board, waspublished under the authorityof the Standards Committee and comes intoeffecton 15 March 1999 BSI 05-1999 ISBN 0 580 30075 7 National foreword This British Standard reproduces verbatim ISO/IEC 14478-1:1998 and implements it as the UK national standard. The UK participation in its pr
3、eparation was entrusted to Technical Committee IST/31, Computer graphics and image processing, 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 keep the
4、 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 publicati
5、ons 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 provisio
6、ns 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 title pa
7、ge, pages ii to iv, pages 1 to 36 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/IEC 14478-1:1998
8、BSI 05-1999 i Contents Page National foreword Inside front cover Foreword iv Text of ISO/IEC 14478-1 1ii blankBSISO/IEC14478-1:1998 ii BSI 05-1999 Contents Page Foreword iv Introduction 1 1 Scope 1 2 Normative references 2 3 Definitions 2 4 Symbols and abbreviations 9 5 Conformance 9 6 Requirements
9、for PREMO 9 6.1 Introduction 9 6.2 Extensibility 10 6.3 Configurability 10 6.4 Incremental, separable development 10 6.5 Simplicity 10 6.6 Ease of use 10 6.7 Other influences 11 6.7.1 Application development environment 11 6.7.2 Execution environment 11 6.8 Functionality 11 6.8.1 Introduction 11 6.8
10、.2 Computer graphics 11 6.8.3 User interfaces 11 6.8.4 Dynamic interactive graphics 11 6.8.5 Animation 11 6.8.6 Audio 12 6.8.7 Video 12 6.8.8 Other and future media 12 6.8.9 Co-representations 12 6.8.10 Cooperating applications 12 7 Architecture of PREMO 12 7.1 Introduction 12 7.2 The standards pers
11、pective 12 7.3 The functional perspective 13 7.3.1 Introduction 13 7.3.2 Description techniques 13 7.3.3 The object model 13 7.3.4 Components 13 7.4 The system perspective 13 7.4.1 Configuring PREMO-based applications 13 7.4.2 Distributed multimedia 14 7.4.3 Communication in PREMO 14 8 Object model
12、14 8.1 Introduction 14 8.2 Basic concepts 14 8.3 Non-object types 15 8.4 Object types 15 8.5 Object identity and object reference 15 8.6 Operations 15 8.7 Subtyping and inheritance 16 8.7.1 Overview 16 8.7.2 Subtyping 16BSISO/IEC14478-1:1998 BSI 05-1999 iii Page 8.7.3 Inheritance 17 8.7.4 Operation
13、dispatching 18 8.8 Abstract Types 19 8.9 Operation request semantics 19 8.10 Protected operations 20 8.11 Object and object reference life cycles 20 8.12 Exceptions 21 9 How PREMO components are described 21 Annex A (normative) Notational conventions 23 A.1 Type declarations 23 A.2 Data type definit
14、ions 23 A.2.1 Simple data type definitions 23 A.2.2 Constructed type definitions 24 A.3 Object type definitions 26 A.4 Definition of finite state machines 27 A.5 Reference to operations and objects 27 A.6 Shorthands for operation specifications 28 A.6.1 State transition operations of finite state ma
15、chines 28 A.6.2 Sequential composition of operations 29 A.7 Specification of components and profiles 30 Annex B (normative) Generic types 31 Annex C (informative) Graphical conventions 33 C.1 Graphical conventions for generic types 35 Figure 1 Type graph 17 Figure 2 Example for operation dispatching
16、 18 Descriptors: data processing, information interchange, graphic data processing, image processing, video data, audio data, coding (data conversion), coded representation.BSISO/IEC14478-1:1998 iv BSI 05-1999 Foreword ISO (the International Organization for Standardization) and IEC (the Internation
17、al Electrotechnical Commission) form the specialized system for worldwide standardization. National bodies that are members of ISO or IEC participate in the development of International Standards through technical committees established by the respective organization to deal with particular fields o
18、f technical activity. ISO and IEC technical committees collaborate in fields of mutual interest. Other international organizations, government and non-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 t
19、echnical committee ISO/IEC JTC1. Draft International Standards adopted by the joint technical committees are circulated to the national bodies for voting. Publication as an International Standard requires approval by at least 75% of the national bodies casting a vote. ISO/IEC 14478-1 was prepared by
20、 Joint Technical Committee ISO/IEC JTC1, Information technology, Subcommittee SC24, Computer graphics and image processing. ISO/IEC 14478 consists of the following parts under the general title Information technology Computer graphics and image processing Presentation Environment for Multimedia Obje
21、cts (PREMO): Part 1: Fundamentals of PREMO; Part 2: Foundation Component; Part 3: Multimedia Systems Services; Part 4: Modelling, Rendering, and Interaction Component. Additional parts may be defined as this work progresses. Annex A and Annex B form an integral part of this part of ISO/IEC 14478. An
22、nex C is for information only.BSISO/IEC 14478-1:1998 BSI 05-1999 1 Introduction The need for a coordinated method for addressing all aspects of the construction of, presentation of, and interaction with multimedia objects has led to the standardization of this Presentation Environment for Multimedia
23、 Objects. Multimedia means objects consisting of still computer graphics, moving computer graphics (animation), synthetic graphics of all types, audio, still images, moving images (including video), images coming from imaging operations, and any other content type or combination of content types tha
24、t can be “presented”. ISO/IEC 14478 is extensible and configurable, and allows the separate, incremental development of additional standardized and non-standardized components to meet the needs of application communities. PREMO currently consists of the following parts: Part 1: Fundamentals of PREMO
25、 Contains a motivational overview of PREMO giving its scope, justification, and an explanation of key concepts, describes the overall architecture of PREMO, and specifies the common semantics for specifying the externally visible characteristics of PREMO objects in an implementation-independent way.
26、 Part 2: Foundation component This component lists an initial set of object types and non-object types useful for the construction of, presentation of, and interaction with multimedia information. Any conforming PREMO implementation shall support these object types. Part 3: Multimedia Systems Servic
27、es Component Describes objects that provide an infrastructure for building multimedia computing platforms that support interactive multimedia applications dealing with synchronized, time-based media in a heterogeneous distributed environment. Part 4: Modelling, Presentation, and Interaction Componen
28、t Describes objects which are needed for advanced computer systems using graphics, video, audio, or other types of presentable media enhanced by time aspects. NOTEFurther internationally standardized components are expected to be developed within ISO/IEC JTC1/SC24 and by other subcommittees. 1 Scope
29、 ISO/IEC14478 specifies techniques for supporting interactive single, and multiple media applications which recognize and emphasize the interrelationships among user interfaces, multimedia applications, and multimedia information interchange. ISO/IEC14478 defines a flexible environment to encompass
30、modular functionality and is extensible through the creation of future components, both within and outside of standards committees. It supports a wide range of multimedia applications in a consistent way, from simple drawings up to full motion video, sound, and virtual reality environments. ISO/IEC1
31、4478 is independent of any particular implementation language, development environment, or execution environment.For integration into a programming environment, the standard shall be embedded in a system dependent interface following the particular conventions of that environment. ISO/IEC 14478 prov
32、ides versatile packaging techniques beyond the capabilities of monolithic single-media systems. This allows rearranging and extending functionality to satisfy requirements specific to particular application areas. ISO/IEC14478 is developed incrementally with parts 1 through 4 initially available. Ot
33、her components are expected to be standardized by ISO/IEC JTC1 SC24 or other subcommittees. ISO/IEC 14478 provides a framework within which application-defined ways of interacting with the environment can be integrated. Methods for the definition, presentation, and manipulation of both input and out
34、put objects are described. Application-supplied structuring of objects is also allowed and can, for example, be used as a basis for the development of toolkits for the creation of, presentation of, and interaction with multimedia and hyper-media documents and product model data. ISO/IEC14478 is able
35、 to support construction, presentation, and interaction with multiple simultaneous inputs and outputs using multiple media. Several such activities may occur simultaneously, and the application program can adapt its behaviour to make best use of the capabilities of its environment. ISO/IEC14478 incl
36、udes interfaces for external storage, retrieval and interchange of multimedia objects.BSISO/IEC 14478-1:1998 2 BSI 05-1999 2 Normative references The following standards contain provisions which, through reference in this text, constitute provisions of this part of ISO/IEC 14478. At the time of publ
37、ication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this part of ISO/IEC 14478 are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and ISO maintain regist
38、ers of currently valid International Standards. ISO/IEC 14478-2:1998, Information technology Computer graphics and image processing Presentation Environment for Multimedia Objects (PREMO) Part 2: Foundation Component. ISO/IEC 14478-3:1998, Information technology Computer graphics and image processin
39、g Presentation Environment for Multimedia Objects (PREMO) Part 3: Multimedia Systems Services. ISO/IEC 14478-4:1998, Information technology Computer graphics and image processing Presentation Environment for Multimedia Objects (PREMO) Part 4: Modelling, Rendering, and Interaction Component. 3 Defini
40、tions For the purposes of ISO/IEC 14478, the following definitions apply. 3.2.1 multimedia The creation, editing, composing, and/or presentation of products consisting of any combination of media. 3.2.1.1 multimedia object an object consisting of one or more types of media that can be presented to a
41、 user 3.2.2 medium (plural media) a means by which information is perceived, expressed, stored, or transmitted. Examples include audio, video, (animated) graphics, images, text 3.2.3 dynamic interactive graphics graphics applications where the graphics varies in real-time in response to user in-puts
42、 3.2.4 animation series of pictures in a time-ordered sequence to display as a video medium. This covers all changes that have a visual effect. It thus includes the time-varying position, shape, colour, transparency, structure, and texture of an object, and changes in lighting, camera position, orie
43、ntation, and focus, and even changes of rendering techniques 3.2.5 text a medium encompassing a character-based encoding only 3.2.6 audio a medium encompassing all forms of information transmitted by sound 3.2.7 video a medium encompassing a continuous series of pictures typically depicting motion o
44、r time sequenced events 3.2.8 co-representation a representation of information where the same information is presented in several different ways from which the most appropriate is chosenBSISO/IEC 14478-1:1998 BSI 05-1999 3 3.2.9 component A PREMO component is a set of related object types and non-o
45、bject types. The object and non-object types of a component are clustered into (component) profiles. 3.2.9.1 standard component a component that is defined in one of the parts of ISO/IEC 14478, or a component that has been registered by an approved registration authority, and conforming to the rules
46、 defined for components in PREMO 3.2.9.2 non-standard component a component that is not a standard component, but which obeys the rules defined by PREMO for conforming components 3.2.10 profile A profile is set of related object types and non-object types from which objects can be instantiated, and
47、a configuration specification which defines dependencies between object types and other profiles. Profiles offer a set of services embodied by the operations defined on its constituent object types. 3.2.10.1 basic profile (of a component) a mandatory set of object and non-object types for a specific
48、 component which shall be provided by all complying implementation of a component 3.2.11 object An entity that encapsulates some private state information or data, a set of associated operations that manipulate the data, and possibly a thread of control so that collectively they can be treated as a
49、single unit. 3.2.11.1 object type it defines the operations of objects; these operations collectively characterize the objects behaviour 3.2.11.2 object reference an object name which reliably denotes a particular object instance. This is a non-object 3.2.12 state information encapsulated within an object that has to be remembered when one operation alters the future behaviour of future operations 3.2.13 identity (of objects) objects have a unique, immutable identity which provides a means to denote or refer to the object independen
