SIST ETS 300 714 E1:2003

SLOVENSKI STANDARD
01-december-2003
Terminalska oprema (TE) – Aplikacijski programski vmesnik za ravnanje z
multimedijskimi in hipermedijskimi informacijskimi objekti
Terminal Equipment (TE); Application Programming Interface (API) for the manipulation
of Multimedia and Hypermedia information objects
Ta slovenski standard je istoveten z: ETS 300 714 Edition 1
ICS:
33.160.60 9HþSUHGVWDYQLPXOWLPHGLMVNL Multimedia systems and
VLVWHPLLQRSUHPD]D teleconferencing equipment
WHOHNRQIHUHQFH
35.180 Terminalska in druga IT Terminal and other
periferna oprema IT peripheral equipment
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN ETS 300 714
TELECOMMUNICATION May 1997
STANDARD
Source: ETSI TC-MTA Reference: DE/MTA-001045
formerly DE/TE-01045
ICS: 33.020
Key words: API, MHEG, multimedia
Terminal Equipment (TE);
Application Programming Interface (API) for the manipulation of
Multimedia and Hypermedia information objects
ETSI
European Telecommunications Standards Institute
ETSI Secretariat
Postal address: F-06921 Sophia Antipolis CEDEX - FRANCE
Office address: 650 Route des Lucioles - Sophia Antipolis - Valbonne - FRANCE
X.400: c=fr, a=atlas, p=etsi, s=secretariat - Internet: secretariat@etsi.fr
Tel.: +33 4 92 94 42 00 - Fax: +33 4 93 65 47 16
Copyright Notification: No part may be reproduced except as authorized by written permission. The copyright and the
foregoing restriction extend to reproduction in all media.
© European Telecommunications Standards Institute 1997. All rights reserved.

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ETS 300 714: May 1997
Whilst every care has been taken in the preparation and publication of this document, errors in content,
typographical or otherwise, may occur. If you have comments concerning its accuracy, please write to
"ETSI Editing and Committee Support Dept." at the address shown on the title page.

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ETS 300 714: May 1997
Contents
Foreword .9
Introduction.9
1 Scope .11
2 Normative references.11
3 Definitions and abbreviations .12
3.1 Definitions .12
3.2 Abbreviations .15
4 Conformance.16
4.1 Implementation conformance .16
4.1.1 Conformance requirements.16
4.1.2 Conformance documentation.16
4.2 Application conformance .17
4.2.1 Strictly conforming application.17
4.2.2 Conforming application.17
4.3 Test methods.17
5 General description .17
5.1 Functional reference model of applications using MHEG.17
5.1.1 Reference model for multimedia applications .17
5.1.2 The MHEG API.22
5.2 Functional specification of the MHEG API.23
5.2.1 MHEG usage specifications .23
5.2.1.1 Definitions.23
5.2.1.2 MHEG objects .23
5.2.1.3 Mh-objects .24
5.2.1.4 Rt-objects .24
5.2.1.5 Channels.24
5.2.1.6 Interchanged MHEG objects .24
5.2.2 Description of MHEG-related services .25
6 API definition principles .26
6.1 Satisfaction of technical requirements on the MHEG API .26
6.2 Use of Interface Definition Language .26
6.2.1 Comprehensive introduction to IDL.26
6.2.2 The Interface Definition Language (IDL) .27
6.2.2.1 Objects .27
6.2.2.2 Requests.27
6.2.2.3 Types.28
6.2.2.4 Interfaces.28
6.2.2.5 Operations .28
6.2.2.6 Attributes.29
6.2.2.7 Subtyping versus inheritance.29
6.2.2.8 Subtyping.29
6.2.2.9 Inheritance.29
6.2.3 Principles for mapping IDL interfaces to API primitives .29
6.2.4 Fulfilment of technical requirements .30
6.3 Overview of the API definition and general principles.30
6.3.1 The MHEG API object model .30
7 Definition of the MHEG API.32
7.1 Mandatory primitives.32

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7.1.1 MHEGEngine object . 32
7.1.1.1 initialiseEngine operation . 32
7.1.1.2 shutdownEngine operation. 32
7.1.1.3 IDL description . 32
7.1.2 NotificationManager object . 32
7.1.2.1 getReturnability operation . 32
7.1.2.2 getNotification operation . 33
7.1.2.3 IDL description . 33
7.1.3 EntityManager object . 33
7.1.3.1 getAvailableMhObjects operation . 33
7.1.3.2 getAvailableRtObjects operation. 34
7.1.3.3 getAvailableChannels operation . 34
7.1.3.4 releaseAlias operation. 34
7.1.3.5 IDL description . 35
7.1.4 Entity object . 35
7.1.4.1 setAlias operation. 35
7.1.4.2 getAlias operation . 35
7.1.4.3 IDL description . 36
7.1.5 MhObject object. 36
7.1.5.1 bind operation . 36
7.1.5.2 unbind operation . 36
7.1.5.3 prepare operation. 37
7.1.5.4 destroy operation . 37
7.1.5.5 getPreparationStatus operation . 38
7.1.5.6 getIdentifier operation . 38
7.1.5.7 kill operation. 38
7.1.5.8 IDL description . 39
7.1.6 MhAction object . 39
7.1.6.1 delay operation. 39
7.1.6.2 IDL description . 40
7.1.7 MhLink object. 40
7.1.7.1 abort operation. 40
7.1.7.2 IDL description . 40
7.1.8 MhModel object . 40
7.1.8.1 IDL description . 41
7.1.9 MhComponent object. 41
7.1.9.1 IDL description . 41
7.1.10 MhGenericContent object. 41
7.1.10.1 copy operation. 41
7.1.10.2 IDL description . 41
7.1.11 MhContent object. 42
7.1.11.1 setData operation. 42
7.1.11.2 getData operation. 42
7.1.11.3 IDL description . 43
7.1.12 MhMultiplexedContent object . 43
7.1.12.1 setMultiplex operation . 43
7.1.12.2 setDemultiplex operation . 44
7.1.12.3 IDL description . 44
7.1.13 MhComposite object. 44
7.1.13.1 IDL description . 45
7.1.14 MhScript object. 45
7.1.14.1 IDL description . 45
7.1.15 MhContainer object. 45
7.1.15.1 IDL description . 45
7.1.16 MhDescriptor object. 45
7.1.16.1 IDL description . 45
7.1.17 RtObjectOrSocket object. 45
7.1.17.1 setGlobalBehaviour operation. 45
7.1.17.2 getGlobalBehaviour operation. 46
7.1.17.3 run operation. 46
7.1.17.4 stop operation . 46
7.1.17.5 IDL description . 47
7.1.18 RtObject object . 47

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7.1.18.1 bind operation.47
7.1.18.2 unbind operation.48
7.1.18.3 new operation .48
7.1.18.4 delete operation.48
7.1.18.5 getAvailabilityStatus operation.49
7.1.18.6 getIdentifier operation.49
7.1.18.7 kill operation.50
7.1.18.8 getRunningStatus operation .50
7.1.18.9 IDL description.50
7.1.19 Socket object.51
7.1.19.1 bind operation.51
7.1.19.2 unbind operation.51
7.1.19.3 getIdentifier operation.52
7.1.19.4 kill operation.52
7.1.19.5 plug operation.52
7.1.19.6 setVisibleDurationPosition operation.53
7.1.19.7 getVisibleDurationPosition operation.53
7.1.19.8 IDL description.54
7.1.20 RtScript object.54
7.1.20.1 setParameters operation .54
7.1.20.2 getTerminationStatus operation .55
7.1.20.3 IDL description.55
7.1.21 RtComponentOrSocket object .55
7.1.21.1 setRGS operation .55
7.1.21.2 getRGS operation.56
7.1.21.3 setOpacity operation.56
7.1.21.4 setPresentationPriority operation.57
7.1.21.5 getOpacity operation.57
7.1.21.6 getEffectiveOpacity operation.58
7.1.21.7 getPresentationPriority operation .58
7.1.21.8 setVisibleDuration operation.58
7.1.21.9 setTemporalTermination operation .59
7.1.21.10 setCurrentTemporalPosition operation.59
7.1.21.11 setSpeed operation.60
7.1.21.12 setTimestones operation .61
7.1.21.13 getInitialTemporalPosition operation .61
7.1.21.14 getTerminalTemporalPosition operation.62
7.1.21.15 getVDLength operation.62
7.1.21.16 getTemporalTermination operation .62
7.1.21.17 getCurrentTemporalPosition operation.63
7.1.21.18 getSpeedRate operation.63
7.1.21.19 getOGTR operation .64
7.1.21.20 getEffectiveSpeedRate operation.64
7.1.21.21 getEffectiveOGTR operation .64
7.1.21.22 getTimestoneStatus operation.65
7.1.21.23 setPerceptibleSizeProjection operation.65
7.1.21.24 setAspectRatio operation.66
7.1.21.25 setVisibleSize operation .66
7.1.21.26 setVisibleSizesAdjustment operation.67
7.1.21.27 setBox operation.67
7.1.21.28 setDefaultBackground operation .68
7.1.21.29 setAttachmentPoint operation .69
7.1.21.30 setAttachmentPointPosition operation.69
7.1.21.31 setVisibleSizesAlignment operation.70
7.1.21.32 setMovingAbility operation.71
7.1.21.33 setResizingAbility operation.71
7.1.21.34 setScalingAbility operation.71
7.1.21.35 setScrollingAbility operation.72
7.1.21.36 getGSR operation.72
7.1.21.37 getPS operation.73
7.1.21.38 getAspectRatio operation .73
7.1.21.39 getPSAP operation .74
7.1.21.40 getVSGS operation.74

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7.1.21.41 getVS operation . 74
7.1.21.42 getBox operation. 75
7.1.21.43 getDefaultBackground operation . 75
7.1.21.44 getVSIAP operation. 76
7.1.21.45 getVSIAPPosition operation. 76
7.1.21.46 getVSEAP operation . 76
7.1.21.47 getVSEAPPosition operation . 77
7.1.21.48 getMovingAbility operation . 77
7.1.21.49 getResizingAbility operation. 78
7.1.21.50 getScalingAbility operation. 78
7.1.21.51 getScrollingAbility operation. 78
7.1.21.52 setSelectability operation . 79
7.1.21.53 setSelectionStatus operation . 80
7.1.21.54 setSelectionPresentationEffectResponsibility operation. 80
7.1.21.55 getSelectability operation . 81
7.1.21.56 getEffectiveSelectability operation . 81
7.1.21.57 getSelectionStatus operation . 82
7.1.21.58 getSelectionMode operation . 82
7.1.21.59 getSelectionPresentationEffectResponsibility operation. 82
7.1.21.60 setModifiability operation. 83
7.1.21.61 setModificationStatus operation. 84
7.1.21.62 setModificationPresentationEffectResponsibility operation. 84
7.1.21.63 getModifiability operation. 85
7.1.21.64 getEffectiveModifiability operation. 85
7.1.21.65 getModificationStatus operation. 86
7.1.21.66 getModificationMode operation. 86
7.1.21.67 getModificationPresentationEffectResponsibility operation 86
7.1.21.68 setNoInteractionStyle operation . 87
7.1.21.69 IDL description . 87
7.1.22 RtComponent object. 92
7.1.22.1 IDL description . 92
7.1.23 RtCompositeOrStructuralSocket object. 92
7.1.23.1 setResizingStrategy operation . 92
7.1.23.2 getResizingStrategy operation . 92
7.1.23.3 setAudibleCompositionEffect operation. 93
7.1.23.4 getAudibleCompositionEffect operation. 93
7.1.23.5 getNumberOfSelectedSockets operation . 94
7.1.23.6 getNumberOfModifiedSockets operation. 94
7.1.23.7 setMenuInteractionStyle operation. 95
7.1.23.8 setScrollingListInteractionStyle operation . 95
7.1.23.9 IDL description . 96
7.1.24 RtComposite object . 97
7.1.24.1 IDL description . 97
7.1.25 StructuralSocket object. 97
7.1.25.1 IDL description . 97
7.1.26 RtGenericContentOrPresentableSocket object. 97
7.1.26.1 setAudibleVolume operation . 98
7.1.26.2 getInitialOriginalAudibleVolume operation . 98
7.1.26.3 getCurrentOriginalAudibleVolume operation. 99
7.1.26.4 getEffectiveOriginalAudibleVolume operation. 99
7.1.26.5 getPerceptibleAudibleVolume operation. 100
7.1.26.6 setButtonInteractionStyle operation . 100
7.1.26.7 IDL description . 101
7.1.27 RtGenericContent object . 101
7.1.27.1 IDL description . 101
7.1.28 GenericPresentableSocket object . 101
7.1.28.1 IDL description . 101
7.1.29 RtContentOrPresentableSocket object. 102
7.1.29.1 setSliderInteractionStyle operation . 102
7.1.29.2 setEntryFieldInteractionStyle operation. 103
7.1.29.3 IDL description . 103
7.1.30 RtContent object. 104
7.1.30.1 IDL description . 104

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7.1.31 PresentableSocket object.104
7.1.31.1 IDL description.104
7.1.32 RtMultiplexedContentOrPresentableSocket object .104
7.1.32.1 setStreamChoice operation .104
7.1.32.2 getStreamChosen operation.105
7.1.32.3 IDL description.105
7.1.33 RtMultiplexedContent object .105
7.1.33.1 IDL description.105
7.1.34 MultiplexedPresentableSocket object .105
7.1.34.1 IDL description.105
7.1.35 Channel object .105
7.1.35.1 bind operation.106
7.1.35.2 unbind operation.106
7.1.35.3 new operation .106
7.1.35.4 delete operation.107
7.1.35.5 getRtAvailabilityStatus operation .107
7.1.35.6 getIdentifier operation.108
7.1.35.7 kill operation.108
7.1.35.8 setPerceptability operation .108
7.1.35.9 getPerceptability operation .109
7.1.35.10 getAssignedPerceptibles operation .109
7.1.35.11 IDL description.109
7.1.36 Parameter definition .110
7.1.37 Exceptions.124
7.1.37.1 InvalidTarget exception.124
7.1.37.2 InvalidParameter exception .124
7.1.37.3 NotBound exception .124
7.1.37.4 AlreadyBound exception.124
7.1.37.5 IDL definition.125
7.2 Optional primitives .125
Annex A (normative): Complete IDL definition of the MHEG API .126
History.127

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Foreword
This European Telecommunication Standard (ETS) has been produced by the Terminal Equipment (TE)
Technical Committee of the European Telecommunications Standards Institute (ETSI).
Introduction
This ETS specifies the abstract Application Programming Interface (API) for the manipulation of
multimedia and hypermedia information objects, i.e. the API that shall be provided by Multimedia and
Hypermedia Experts Group (MHEG) engines for their control by MHEG applications.
This ETS is part of a broader standardisation framework that specifies the usage of MHEG so that
interoperable equipment can be effectively developed to support multimedia information services and
applications. This implies:
- specifying additional constraints on the use of MHEG objects within distributed systems and
applications using telecommunication networks;
- defining APIs that building blocks of architectures using MHEG should provide;
- defining MHEG profiles complementing the MHEG-1 standard by specifying restrictions on the
coded representation and specifying the complete required behaviour of an MHEG engine that
should be supported for a given category of applications and/or terminal equipment;
- defining an MHEG script interchange representation;
- defining end-to-end protocols for multimedia/hypermedia information services using MHEG;
- specifying conformance testing procedures for these standards.
Functional and technical requirements of this ETS have been described in ETR 225 [4].
Transposition dates
Date of adoption: 18 April 1997
Date of latest announcement of this ETS (doa): 31 August 1997
Date of latest publication of new National Standard
or endorsement of this ETS (dop/e): 28 February 1998
Date of withdrawal of any conflicting National Standard (dow): 28 February 1998

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1 Scope
Multimedia and Hypermedia Experts Group (MHEG) Part 1 (ISO/IEC DIS 13522-1 [1]) is a generic
standard, which specifies the coded representation of interchanged multimedia/hypermedia information
objects (MHEG objects). These so-called MHEG objects are handled, interpreted and presented by
MHEG engines.
This European Telecommunication Standard (ETS) specifies the abstract Application Programming
Interface (API) for the manipulation of multimedia and hypermedia information objects, i.e. the API that
shall be provided by MHEG engines for their control by MHEG applications.
This API meets the following requirements:
- it is independent of the programming language used for the MHEG application;
- it is independent of the underlying operating system;
- it is independent of the mechanism used for interchanging information between the API user (i.e.
MHEG application) and the API provider (i.e. MHEG engine, the messages that are exchanged as
the result of triggering API primitives);
- it is independent of the actual encoding of these messages;
- it is generic and meant to cover all application requirements;
- it is conformance testable;
- it aims to be as easy as possible to implement.
2 Normative references
This ETS incorporates by dated and undated reference, provisions from other publications. These
normative references are cited at the appropriate places in the text and the publications are listed
hereafter. For dated references, subsequent amendments to or revisions of any of these publications
apply to this ETS only when incorporated in it by amendment or revision. For undated references the latest
edition of the publication referred to applies.
[1] ISO/IEC DIS 13522-1 (1994): "Information technology - Coding of Multimedia
and Hypermedia Information - Part 1: MHEG object representation - Base
Notation".
[2] ISO/IEC 9646 Parts 1 to 5 (1991): "Information Technology - Open Systems
Interconnection - Conformance testing methodology and framework".
[3] ETR 173 (1995): "Terminal Equipment (TE); Functional Model for Multimedia
Applications".
[4] ETR 225 (1995): "Terminal Equipment (TE); Application Programmable
Interface (API) and script representation for MHEG; Requirements and
framework".
[5] (Reserved).
[6] (Reserved).
[7] ITU-T Recommendation I.113 (1994): "Vocabulary of terms for broadband
aspects of ISDN".
[8] ITU-T Recommendation I.112 (1993): "Vocabulary of terms for ISDNs".
[9] CCITT Recommendation Q.9 (1990): "Vocabulary of switching and signalling
terms".
[10] ISO/IEC 14750-1 Working Draft: "CORBA IDL as an Interface Definition
Language for ODP Systems".
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3 Definitions and abbreviations
3.1 Definitions
For the purposes of this ETS, the following definitions apply:
NOTE: Due to the particular nature of this ETS, some of the words and expressions used in
this ETS come from the "telecommunication services" standards glossary, while others
come from the "software technology" standards glossary. This leads to words whose
meaning vary according to the context, i.e. the expression within which they are used.
For this reason, many of these expressions are defined in this subclause.
Should any ambiguity occur, definitions of the following standards would apply, in
decreasing order:
- ISO/IEC DIS 13522-1 [1];
- any other standard part of ISO/IEC 13522 [1];
- ITU-T Recommendation I.113 [7];
- ITU-T Recommendation I.112 [8];
- CCITT Recommendation Q.9 [9].
Application Programming Interface (API): A boundary across which a software application uses
facilities of programming languages to invoke software services. These facilities may include procedures
or operations, shared data objects and resolution of identifiers.
function family: A cluster of functional MHEG API requirements consisting of functions with related
semantics and applying to the same type of target.
hypermedia: The ability to access monomedia and multimedia information by interaction with explicit
links.
interactive service: A service which provides the means for bidirectional exchange of information
between users or between users and hosts. Interactive services are subdivided into three classes of
services: conversational services, messaging services and retrieval services (ITU-T
Recommendation I.113 [7]).
local application: A piece of software which is part of the (telecommunication) application and is running
on the considered equipment.
MHEG API: The API provided by an MHEG engine to MHEG applications for the manipulation of MHEG
objects, as defined in this ETS.
MHEG application: A piece of software which uses the MHEG API. An MHEG application is therefore a
client of an MHEG engine.
MHEG engine: A process or a set of processes that interpret MHEG objects encoded according to the
encoding specifications of ISO/IEC DIS 13522-1 [1]: Abstract Syntax Notation One (ASN.1) for Part 1,
Standard Generalized Markup Language (SGML) for Part 2.
MHEG using application: An application which involves the interchange of MHEG objects within itself or
with another application.
multimedia and hypermedia application: An application which involves the presentation of multimedia
information to the user and the interactive navigation across this information by the user.

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Multimedia And Hypermedia Information Retrieval Services (M&HIRS): A generic set of services
which provide users with the capability to access and interchange multimedia and hypermedia
information.
multimedia application: An application which involves the presentation of multimedia information to the
user.
multimedia: The property of handling several types of representation media.
primitive: One of the basic entry points provided by a provider module to any user module to enable the
user module to access the software service(s) supplied by the provider module.
software application: A piece of software answering a set of user's requirements and for use by a
computer user.
software service: A set of functions provided by a (server) software or system to a client software or
system, usually accessible through an application programming interface.
telecommunication application: A set of a user's requirements (CCITT Recommendation Q.9 [9]).
telecommunication service: That which is offered by an administration to its customers in order to
satisfy a specific telecommunication requirement (ITU-T Recommendation I.112 [8]).
terminal application: A piece of software running on the terminal and performing that part of the
processing required to make the terminal appropriate for user access to the application. The terminal
application is usually the "master" module in the terminal.
user: A person or machine delegated by a customer to use the services and/or facilities of a
telecommunication network (ITU-T Recommendation I.112 [8]).
action object: An object that provides operation on objects: e.g. to change their attributes or states.
channel: A logical space in which rt-components are positioned for final presentation. Channels are
mapped by the MHEG engine to physical devices such as screen windows or loudspeaker for making the
rt-objects within them perceivable by the user.
component object: An abstraction which represents objects of Content or Composite type.
composite object: A list of Composition Elements grouped for presentation. The presentation of a
Composite object consists of the presentation of its Composition Elements.
container object: A means to group objects without specifying specific relationships.
content object: Encoded generic value, media or non-media data.
descriptor object: A structure for the interchange of resource information about a single or a set of other
interchanged objects.
IDL attribute: An identifiable association between an object and a value. An attribute A is made visible to
clients as a pair of operations: get_A and set_A. Read only attributes only generate a get operation.
IDL class: An implementation that can be instantiated to create multiple objects with the same behaviour.
An object is an instance of a class. Types classify objects according to a common implementation.
IDL data type: A categorisation of values operation arguments, typically covering both behaviour and
representation (i.e., the traditional non-Object Oriented (OO) programming language notion of type).
IDL instance: A object is an instance of an interface if it provides the operations, signatures and
semantics specified by that interface. An object is an instance of an implementation if its behaviour is
provided by that implementation.

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IDL object: A combination of state and a set of methods that explicitly embodies an abstraction
characterised by the behaviour of the relevant requests. An object is an instance of an implementation
and an interface. An object models a real-world-entity, and it is implemented as a computational entity
that encapsulates state and operations (internally implemented as data and methods) and responds to
requester services.
IDL operation: A service that can be requested. An operation has an associated signature, which may
restrict which actual parameters are valid.
Interface Definition Language (IDL): A language that specifies types and objects by specifying their
interface. It provides a conceptual framework for describing the objects.
link object: An object which defines spatio-temporal relationships between other objects.
macro object: An object that provides the facility to replace the parameters in frequently used action
objects.
mh-object: MhObjects (and their subtypes) match form b) objects as defined in ISO/IEC DIS 13522-1 [1],
subclause 6.2.4, i.e. objects available to the MHEG engine.
MHEG elementary action: An attribute of the MHEG Action class which instructs an object to perform a
certain operation: e.g. to change one of its attributes or states.
MHEG entity: Any MHEG object, rt-object, content data, script data, socket, channel or other construction
identified or referred to in ISO/IEC DIS 13522-1 [1].
MHEG interpretation service: The service takes interchanged MHEG objects and messages issued by
the presentation system as an input. It analyses this data in order to trigger the presentation of content
data according to its semantics.
MHEG object handling service: This facility physically creates, handles and maintains intermediate data
structures necessary to implement a client access to the MHEG objects and their contents.
MHEG object: A coded representation of an MHEG object class instance.
model object: Object instanciations from the MHEG classes.
notification: A primitive issued by the server on its own initiative to forward information to the client.
request: A primitive issued by the client on its own initiative to forward information to the server.
response: A primitive issued by the server as a reply to a request to forward information to the client.
rt-object: RtObjects (and their subtypes) match form c objects as defined in ISO/IEC DIS 13522-1 [1],
subclause 6.2.4, i.e. instances of MhObjects available to the presentation process.
script object: Object that provides the structure to interchange script data in a specified encoded form.
socket: An element of an rt-composite. Rt-components are plugged into sockets. Different types of
sockets are defined depending on the rt-component plugged into the socket:
- empty socket, i.e. a null rt-component is plugged;
- presentable socket, i.e. an rt-content or an rt-multiplexed content is plugged;
- structural socket, i.e. an rt-composite is plugged.

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3.2 Abbreviations
For the purposes of this ETS, the following abbreviations apply:
AP Attachment Point
API Application Programming Interface
ASN.1 Abstract Syntax Notation One
C1 State period for a Channel: "non available"
C2 State period for a Channel: "processing"
C3 State period for a Channel: "available"
C4 State period for a Channel: "processing"
CGS Channel Generic Space
CGSU Channel Generic Space Unit
CORBA Common Object Request Broker Architecture
EBNF Extended Backus Naur Form
GSR Generic Spatial Ratio
GTU Generic Temporal Unit
IDL Interface Definition Language (as defined in ISO/IEC 14750-1 [10])
IOGTR Initial Original generic space Generic Temporal Ratio
IOV Initial Original audible Volume
MCU Multipoint Control Unit
mh multimedia/hypermedia
MHEG Multimedia and Hypermedia information coding Experts Group
MPEG Moving Picture Experts Group
O1 State period for an mh-object: "not ready"
O2 State period for an mh-object: "processing"
O3 State period for an mh-object: "ready"
O4 State period for an mh-object: "processing"
OGS Original Generic Space
OGSU Original generic space Generic Spatial Unit
OGTR Original generic space Generic Temporal Ratio
OGTU Original generic space Generic Temporal Unit
OO Object Oriented
OV Original Volume
PRGS Parent Relative Generic Space
PS Perceptible Size
PSAP Perceptible Size Attachment Point
R1 State period for an rt-object: "not available"
R2 State period for an rt-object: "processing"
R3 State period for an rt-object: "available"
R4 State period for an rt-object: "processing"
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