1、STDmITU-T RECMN T-LTL-ENGL L97b 9 4862591 Ob35430 Tb7 D INTERNATIONAL TELECOMMUNICATION UN ION ITU=T - TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU TA71 (1 0196) SERIES T: TERMINALS FOR TELEMATIC SERVICES P rot oco1 s for i n te ract ive a u d i ovis ua I servi ces : coded representation of multi
2、media and hypermedia objects ITU-T Recommendation T. 171 (Previously CCITT Recommendation) STD-ITU-T RECMN T.17L-ENGL 199b LiBb2571 Ob35431 7T5 D ITLJ-T T-SERIES RECOMMENDATIONS TERMINALS FOR TELEMATIC SERVICES - For further details, please ref to ITU-T List of Recommendations. FOREWORD The IT-T (Te
3、lecommunication Standardization Sector) is a permanent organ of the International Telecommunication Union (ITU). The ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommen- dations on them with a view to standardizing telecommunications on a worldwide basis.
4、 The World Telecommunication Standardization Conference (WTSC), which meets every four years, establishes the topics fer study by the ITLJ-T Study Groups which, in their turn, produce Recommendations on these topics. The approval of Recommendations by the Members of the ITU-T is covered by the proce
5、dure laid down in WTSC Resolution No. 1 (Helsinki, March 1-12, 1993). ITU-T Recommendation T.171 was prepared by ITLJ-T Study Group 8 (1993-1996) and was approved by the WTSC (Geneva, October 9-18, 1996). NOTE in this Recommendation, the expression “Administration” is used for conciseness to indicat
6、e both a telecommunication administration and a recognized operating agency. O ITU 1997 All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the I
7、TU. Recommendation T.171 (10/96) i STD-ITU-T RECMN T.17L-ENGL L77b D 4Bb259L Ob35433 778 W CONTENTS Introduction O . 1 Application domains for requirements analysis 0.2 MultimediaHypermedia application requirements . 0.3 Rationale for standardisation of multimedia and hypermedia information . 0.4 T.
8、171 Objectives . 0.5 T.171 concepts 0.6 The MHEG application interface 0.7 T . 17 1 extensibility Seope . 1.1 Specificity of the scope . 1.2 Issues outside T.171 scope . Conformance 2.1 Profiles 2.2 Syntax . 2.3 Semantics Normative References Definitions Symbols and abbreviations . SECTION 1 . OVERV
9、IEW . 6 T . 171 principal feature . 6.1 Interchanging multimedia objects . 6.2 The object-oriented approach . 6.3 Technical features . 7 MHEG Engine Assumptions 7.1 Handling and Interchange of objects 7.2 The MHEG application interface 7.3 Exception handling . 8 Methodology Methodology of representa
10、tion of MHEG objects 8.1 Modularity 8.2 SECTION 2 - GENERIC UTILITY AND USEFUL DEFINITION MECHANISMS . 9 Presentation Mechanism 9.1 Presentation Space (PS) 9.2 riginal Presentation Space (OPS) . 9.3 Channel Presentation Space (CPS) . 9.4 Relative Presentation Space (RPS) . 10 Generic identification
11、mechanism 10.1 External identification . 10.2 Internal identification 10.3 Symbolic identification . Il Generic reference mechanism 1 1.1 Generic reference using generic identification . 1 1.2 Predefined references 11.3 ? reference . 9.5 CPS mapping 11 Recommendation T.171 (10/96) Page 1 1 2 4 5 6 1
12、0 10 10 11 11 11 11 11 11 12 12 19 21 21 21 21 23 27 27 28 29 29 29 29 33 33 34 37 38 39 39 40 41 43 47 47 47 50 50 . STD-ITU-T RECMN T.17L-ENGL 199b I Li662591 Ob35434 604 W 12 Generic Value . 12.1 Generic boolean 12.2 Generic numeric 12.3 Generic integer 12.4 Generic ratio . 12.5 Generic string 12
13、.6 Generic reference . 12.7 Generic list 13 Macro Mechanism 14 Hooks . 15 Extensibility . 15.1 Catalogues . f5.2 Addition ofNew MHEG object classes 15.3 Extensibility Provision SECTION 3 - OVERVIEW OF MHEG CLASSES 16 MHEG object classes overview . Structure of MH-Object Class 17.1 Class identificati
14、on . 17.2 MHEG-ID . 17.3 General object information . I 17 18 Structure of Action Class . 18.1 Elementary actions 18.2 Basic action object 18.3 Nested action object 18.4 Macro action object Structure of Link Class . 19.1 Link Condition 19.2 Link Effect 19.3 Basic link object . 19.4 Nested link objec
15、t . 19.5 Macro link object Structure of Model Class Structure of Script Class . 19 20 21 Page 52 53 53 53 53 54 54 54 54 56 57 57 58 58 58 58 59 59 59 59 60 60 61 61 61 61 62 71 71 71 72 72 72 22 Structure of Component Class 72 23 24 25 Structure of Content Class Structure of Multiplexed Content Cla
16、ss . 25.1 Availability Start-up . 25.2 Availability Close-down . 25.4 Rt-Availability Close-down 25.5 Composition Element . 25.6 Composition example . Structure of Container Class 26.1 Container Start-up . 26.2 Container Close-down 26.3 Container Element Structure of Composite Class . 25.3 RT-Availa
17、bility Start-up . 26 73 73 74 75 76 76 76 77 77 78 78 78 78 . Recommendation T.171 (10/96) 111 STD-ITU-T RECMN T-17L-ENGL L99b qBb2591 Ob35435 540 D 27 Structure of Descriptor Class . 27.1 Related Object 27.2 Other Descriptor . 27.3 Readme . 27.4 System Readable Material 27.5 Channel Information . 2
18、7.6 Catalogued Style Information . 27.7 27.8 Cat Ext Attribute Info . Cat Ext elementary action info . SECTION 4 - MHEG ENTITIES COMMON BEHAVIOUR 28 29 30 31 32 33 I 34 35 36 MHEG entity behaviour . MHEG entity state definition . MHEG object availability . . 29.3 Channel availability 29.4 Rt-object
19、availability . 29.5 Rt-Component running behaviour 29.6 Rt-Component presentation behaviour . Life cycle of MHEG entities 29.1 29.2 Link activation General action mechanisms 3 1.1 Action treatment . 3 1.2 Processing of link effect . 3 1.3 3 i . 4 Resolution of target set . 3 1.5 Arithmetic precision
20、 . 32.1 Elementary actions 32.2 Get actions Basic processing of an elementary action . Common action effects and handling . 32.3 Recommended exception handling . Postpone Behaviour . 33.1 Behaviour attributes and statuses 33.2 Actions to change the behaviour . Returnability Behaviour . 34.1 Behaviou
21、r attributes and statuses 34.2 Actions to change the behaviour . Alias Behaviour 35.1 Behaviour attributes and statuses 35.2 Actions to change the behaviour . Extensibility Behaviour 36.1 Behaviour attributes and statuses 36.2 Catalogued Attribute . 36.3 Actions to change the behaviour . 36.4 Action
22、s to retrieve the behaviour SECTION 5 . MHEG OBJECTS BEHAVIOUR 37 MHEG Objects Availability Behaviour . 37.2 Preparation Status . 37.1 37.3 37.4 Behaviour attributes and statuses Actions to change the behaviour . Actions to retrieve the behaviour Page 79 79 81 81 81 81 82 82 82 82 82 82 83 84 85 86
23、88 89 92 92 92 93 95 95 95 96 96 96 97 97 97 97 98 98 98 98 98 98 99 99 99 99 100 101 101 101 101 101 104 iv Recommendation T.171 (10/96) STD-ITU-T RECMN T.17L-ENGL Lb m V8b259L Ub3543b V87 38 I 39 I 40 41 Link Object Activation Behaviour . 38.1 Behaviour attributes and statuses 38.2 Activation Stat
24、us 38.3 Actions to change the behaviour . 38.4 Actions to retrieve the behaviour Link Object Abort Behavio ur . 39.1 Behaviour attributes and statuses 39.2 Actions to change the behaviour . Content Class Generic Value Storage Behavio ur . 40.1 Behaviour attributes and statuses 40.2 Data . 40.3 Actio
25、ns to change the behaviour . 40.4 Actions to retrieve the behaviour Content Class Copy Behaviour 41 . 1 Behaviour attributes and statuses 41.2 Actions to change the behaviour . - SECTION 6 . RT-OBJECTS BEHAVIOUR 42 43 44 45 46 47 48 Rt-Objects Availability Behavio ur . Behaviour attributes and statu
26、ses 42.2 Rt-Availability Status . Actions to change the behaviour . Actions to retrieve the behaviour Rt-Objects Running Behaviour Behaviour attributes and statuses 43.2 Running Status Actions to change the behaviour . Actions to retrieve the behaviour Rt-Script Passing Parameters Behaviour 44.1 Beh
27、aviour attributes and statuses 44.2 Actions to change the behaviour . Rt-Scripts Termination Behaviour . 45.1 Behaviour attributes and statuses 45.2 Termination Status 45.3 Actions to retrieve the behaviour Sockets Presentation and Structural Dynamism Behaviour . 46.1 Behaviour attributes and status
28、es 46.2 Actions to change the behaviour . Rt-Composite Navigation Behaviour . 47.1 Behaviour attributes and statuses 47.2 Rt-Composite Address 47.3 Navigation Command . 47.4 Child . 47.5 Emptychild . 47.6 Sibling . 47.7 Ancestor 47.8 Actions to retrieve the behaviour Rt-Components Rps Assignment Beh
29、aviour Behaviour attributes and statuses 48.2 RPS Assignment . Actions to change the behaviour . Actions to retrieve the behaviour 42.1 42.3 42.4 43.1 43.3 43.4 48.1 48.3 48.4 Recommendation T.171 (10196) Page 104 104 105 105 105 106 106 106 107 107 107 107 112 113 113 113 114 114 114 114 114 116 11
30、7 117 117 117 119 120 120 120 121 121 121 121 122 122 122 124 124 124 124 124 124 124 124 125 125 125 125 125 126 V STD-ITU-T RECMN T-17L-ENGL L77b 48b259L Ob35437 313 D Page 49 Rt-Components Perceptability Behaviour 127 49.1 Behaviour attributes and statuses 127 49.2 Perceptability 127 49.3 Present
31、ation Priority . 127 49.4 Actions to change the behaviour . 127 49.5 Actions to retrieve the behaviour 129 50 Rt-Components Temporal Behaviour 50.1 Behaviour attributes and statuses 50.2 OD 50.3 POD 50.4 OVD 50.5 PVD 5Q.6 Temporal Termination 50.7 PVD Position 50.8 CTP . 50.9 GTF . 50.10 Timestone S
32、tatus . 50.1 1 Timestone ID 50.12 Expected OVD Result . 50.13 Expected PVD Result . 50.14 Actions to change the behaviour . 50.15 Actions to retrieve the behavio ur 129 129 130 130 130 130 130 131 132 133 133 133 133 133 133 136 51 Rt-Components Spatial Behaviour . 141 51.1 Behaviour attributes and
33、statuses 141 51.2 51.3 51.4 51.5 51.6 51.7 51.8 51.9 51.10 51.11 51.12 51.13 51.14 51.15 51.16 51.17 51.18 51.19 os . POS . Aspect Ratio Resizing Strategy ovs OAP OVS Position PVS b OVS Proj Strategy PAP . PVS Position . GSF . Spatial Control User Spatial Control . Expected Axis Result Param . Point
34、 Type Param . Actions to change the behaviour . Actions to retrieve the behaviour 141 141 141 142 143 143 143 144 144 144 144 144 145 145 145 145 145 151 52 Rt-Components Audible Behaviour . 157 52.1 Behaviour attributes and statuses 157 52.2 OV 157 52.3 CV . 157 52.4 PCV 157 52.5 GVF 158 52.6 Actio
35、ns to change the behaviour . 158 52.7 Actions to retrieve the behaviour 159 vi Recommendation T.171 (10/96) STD-ITU-T RECMN T-LiL-ENGL L97b 4Bb2591 b35438 25T Page 53 Rt-Mux Stream Choice Behavio ur . 53.1 Behaviour attributes and statuses 53.2 Stream Choice . 53.3 Stream Chosen State . 53.4 Stream
36、Identification . 53.5 Actions to change the behaviour . 53.6 Actions to retrieve the behaviour 54 Interaction Behaviour . 54.1 Behaviour attributes and statuses 54.2 Interaction Type 54.3 Interaction Status 54.4 Selection Status . 54.5 Modification Status 54.6 Interaction Ability . 54.7 Selectabilit
37、y 54.8 Modifiability . 54.9 Min Interact Required . - 54.10 Max Interact Required 54.1 1 Number of Interacted Sockets . 54.12 Actions to change the behaviour . 54.13 Actions to retrieve the behaviour 55 Rt-Components Style Behaviour 55.1 Behaviour attributes and statuses 55.3 Actions to change the b
38、ehaviour . 55.4 Actions to change the behaviour . Rt-Contents Anchor Behavio ur 56.1 Behaviour attributes and statuses 56.2 Actions to change the behaviour . 55.2 Style 56 SECTION 7 - CHANNELS BEHAVIOUR 57 Channel Availability Behaviour . 57.1 Behaviour attributes and statuses 57.2 Channel Availabil
39、ity Status 57.3 Actions to change the behaviour . 57.4 Actions to retrieve the behaviour 58 Channel Perceptability Behaviour 58.1 Behaviour attributes and statuses 58.2 Channel Perceptability 58.3 Actions to change the behaviour . 58.4 Actions to retrieve the behaviour Channel Presentation Space Beh
40、aviour 59.1 Behaviour attributes and statuses 59.2 Actions to change the behaviour . 59 SECTION 8 - CHANNELS AND RT-COMPONENTS BEHAVIOUR 60 Channels and Rt-Components Events Behaviour 60.1 Behaviour attributes and statuses 60.2 Event . 60.3 Event Data 60.4 Actions to change the behaviour . 60.5 Acti
41、ons to retrieve the behaviour Recommendation T.171 (10196) . 160 160 161 161 161 161 161 162 163 163 163 163 164 164 164 164 164 165 165 166 167 169 170 170 170 170 171 171 171 173 173 173 173 173 174 175 175 175 175 176 176 176 176 177 177 177 177 177 177 178 vii SECTION 9 . DETAILED REPRESENTATION
42、 OF MHEG OBJECTS 61 MH-object class representation attributes 61.1 MH-object Class . 61.2 Class Identification . 61.3 Class ID 6 1.4 Description 61.5 Name . 61.6 Owner . 61.7 Version 61.8 Date . 61.9 Keywords 61.10 Copyright 61.1 1 Copyright ID . 6 1 . 12 Copyright Number 61.13 Licence 6 1.14 Cache
43、Priority . 61.15 Comments . I 62 Action class representation attributes . 62.1 Action Class - I 62.2 Synchro Indicator Param 62.3 Synchro Indicator Macro 62.5 Synchronised Action . 62.6 Action Object 62.4 Synchro Indicator 63 Link class representation attributes 63.1 Link Class . 63.2 Link Condition
44、 63.3 Trigger Condition . 63.4 Constraint Condition . 63.5 Source Value . 63.6 Comparison Operation 63.7 Comparison Value 63.8 Previous Condition . 63.9 Current Condition . 63.10 Comparison Operator 63.1 1 Logical Combination 63.12 Logical Operator . 63.13 Condition 63.14 Link Effect 63.15 Macro Par
45、ameter Resolution 63.16 Usage Value 64 Model class representation attributes . 64.1 Model Class 65 Script class representation attributes 65.1 Script Class . 65.2 Script Classification 65.3 Script Data 65.4 Script Inclusion . 65.5 InterchangedScript 66.1 Component Class 66 Component class representa
46、tion attributes . Page 179 179 179 179 180 180 180 180 180 180 180 180 180 180 180 181 181 181 181 181 181 182 182 182 182 182 183 183 183 183 183 183 183 183 183 184 184 184 184 184 184 184 184 185 185 185 185 185 185 185 186 viii Recommendation T.171 (10/96) STD-ITU-T RECMN T-17L-ENGL L99b W 48b25
47、7L b35440 908 67 68 69 70 71 Content class representation attributes . 67.1 Content Class 67.2 Content Data . 67.3 Data Inclusion . Multiplexed content class representation attributes . 68.1 Multiplexed Content Class Composite class representation attributes 68.2 Multiplexed Stream . 69.1 Composite
48、Class . 69.2 Availability Start-up . 69.3 Availability Close-down . 69.4 Rt-Availability Start-up 69.5 Rt-Availability Close-down 69.6 Link Object 69.7 Nb of Elements . 69.8 Composition Element . 69.9 Element Index . 69.10 Associated Model . 69.1 1 Label . 70.1 Container Class . 70.2 Container Start
49、-up . 70.3 Container Close-down 70.4 Container Element Container class representation attributes Descriptor class representation attributes . 71.1 71.2 71.3 71.4 71.5 71.6 71.7 71.8 71.9 71.10 71.11 71.12 71.13 71.14 71.15 71.16 71.17 71.18 71.19 7 1.20 71.21 7 1.22 7 1.23 7 1.24 71.25 71.26 Descriptor Class Related Object Object Information Object Size Class Specific Information Script Class Information . Content Class Information Mux Content Class Info Number of Streams . Stream Information . Alternative Object . Alternative Readme Offset Readme
