1、BSI Standards PublicationBS ISO/IEC 23008-11:2015Information technology High efficiency codingand media delivery inheterogeneous environmentsPart 11: MPEG Media TransportComposition InformationBS ISO/IEC 23008-11:2015 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of
2、 ISO/IEC23008-11:2015.The UK participation in its preparation was entrusted to TechnicalCommittee IST/37, Coding of picture, audio, multimedia andhypermedia information.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not purport
3、to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. The British Standards Institution 2015. Published by BSI StandardsLimited 2015ISBN 978 0 580 84993 0ICS 35.040Compliance with a British Standard cannot confer immunity fromlegal obligations.This B
4、ritish Standard was published under the authority of theStandards Policy and Strategy Committee on 30 April 2015.Amendments issued since publicationDate Text affectedBS ISO/IEC 23008-11:2015Information technology High efficiency coding and media delivery in heterogeneous environments Part 11: MPEG M
5、edia Transport Composition InformationTechnologies de linformation Codage haute efficacit et livraison des medias dans des environnements htrognes Partie 11: Informations de composition pour le transport des medias MPEGINTERNATIONAL STANDARDISO/IEC23008-11Reference numberISO/IEC 23008-11:2015(E)Firs
6、t edition2015-04-01 ISO/IEC 2015BS ISO/IEC 23008-11:2015ii ISO/IEC 2015 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO/IEC 2015All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanic
7、al, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below or ISOs member body in the country of the requester.ISO copyright officeCase postale 56 CH-1211 Geneva 20Tel. + 41 22 749 01 11Fax
8、 + 41 22 749 09 47E-mail copyrightiso.orgWeb www.iso.orgPublished in SwitzerlandISO/IEC 23008-11:2015(E)BS ISO/IEC 23008-11:2015ISO/IEC 23008-11:2015(E)Foreword ivIntroduction v1 Scope . 12 Normative references 13 Symbols and abbreviated terms . 14 Overview . 15 Composition Information 25.1 Introduc
9、tion 25.2 Structure of the CI document . 35.2.1 Overview . 35.3 The attributes of a CI document . 45.3.1 The begin attribute . 45.3.2 The end attribute 45.3.3 The dur attribute . 45.3.4 The clipBegin attribute . 55.3.5 The clipEnd attribute 55.3.6 The refDiv attribute 55.3.7 The style attribute 55.3
10、.8 The xlink:href attributes 55.3.9 The xlink:actuate attributes . 55.3.10 The viewRole attributes 55.3.11 The isDependent attributes 55.3.12 The depId attributes . 65.3.13 The refId attribute . 65.3.14 The mediaSrc attribute . 65.3.15 The obsolete attribute 75.3.16 The obsoleteTime attribute. 75.4
11、The elements of a CI document 85.4.1 The CI element . 85.4.2 The reference element 85.4.3 The view element 95.4.4 The area element 105.4.5 The MediaSync element 115.4.6 The sourceList element . 126 HTML data attributes 126.1 Introduction . 126.2 Attributes 126.2.1 data-version attribute 126.2.2 data
12、-ci attribute .127 Update Mechanism 137.1 Introduction . 13Annex A (informative) XML Schema of Composition Information 14Annex B (informative) Examples of CI document .17Bibliography .34 ISO/IEC 2015 All rights reserved iiiContents PageBS ISO/IEC 23008-11:2015ISO/IEC 23008-11:2015(E)ForewordISO (the
13、 International Organization for Standardization) and IEC (the International 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 es
14、tablished by the respective organization to deal with particular fields of technical activity. ISO and IEC technical committees collaborate in fields of mutual interest. Other international organizations, governmental and non-governmental, in liaison with ISO and IEC, also take part in the work. In
15、the field of information technology, ISO and IEC have established a joint technical committee, ISO/IEC JTC 1.The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular the different approval criteria need
16、ed for the different types of document should be noted. This document was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights
17、. ISO and IEC shall not be held responsible for identifying any or all such patent rights. Details of any patent rights identified during the development of the document will be in the Introduction and/or on the ISO list of patent declarations received (see www.iso.org/patents).Any trade name used i
18、n this document is information given for the convenience of users and does not constitute an endorsement.For an explanation on the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISOs adherence to the WTO principles in the Technical Barrie
19、rs to Trade (TBT), see the following URL: Foreword Supplementary information .The committee responsible for this document is ISO/IEC JTC 1, Information technology, Subcommittee SC 29, Coding of audio, picture, multimedia and hypermedia information.ISO/IEC 23008 consists of the following parts, under
20、 the general title Information technology High efficiency coding and media delivery in heterogeneous environments: Part 1: MPEG media transport (MMT) Part 2: High efficiency video coding (HEVC) Part 3: 3D Audio Part 5: HEVC Conformance testing and reference software Part 8: Confomance Specification
21、for HEVC Part 10: MPEG Media Transport Forward Error Correction (FEC) codes Part 11: MPEG Media Transport Composition Information Part 12: Image file format Part 13: MMT Implementation guidelinesiv ISO/IEC 2015 All rights reservedBS ISO/IEC 23008-11:2015ISO/IEC 23008-11:2015(E)IntroductionThis part
22、of ISO/IEC 23008 specifies technologies for the delivery of coded media data for multimedia services over concatenation of heterogeneous packet-based network segments, including bidirectional IP networks and unidirectional digital broadcasting networks. In this part of ISO/IEC 23008, “coded media da
23、ta” includes both timed audiovisual media data requiring synchronized decoding and presentation of each specific unit of data at a designated time and non-timed data that could be decoded and presented at an arbitrary time based on the context of the service or the user interaction.MMT is designed u
24、nder the assumption that the coded media data will be delivered through a packet-based delivery network. Several characteristics of such delivery environments have been taken into consideration, such as non-constant end-to-end delivery delay of each packet from the sending entity to the receiving en
25、tity and means to distinguish signaling messages from the media data provided by the underlying network.For efficient and effective delivery of coded media data over heterogeneous packet-based delivery networks, this part of ISO/IEC 23008 provides the following elements: logical model to construct c
26、ontent composed of components from various sources (e.g. content for mash-up applications); structure of data conveying information about the coded media data for processing by the delivery layer (e.g. packetization and adaptation); packetization method and the structure of the packet to deliver med
27、ia content over packet-based delivery networks supporting hybrid multichannel delivery that is agnostic to the specific type of media or coding method; format of signaling messages to manage the presentation and delivery of media content; format of information to be exchanged across layers of the de
28、livery network to facilitate cross layer communication. ISO/IEC 2015 All rights reserved vBS ISO/IEC 23008-11:2015BS ISO/IEC 23008-11:2015Information technology High efficiency coding and media delivery in heterogeneous environments Part 11: MPEG Media Transport Composition Information1 ScopeThis pa
29、rt of ISO/IEC 23008 specifies MPEG Composition Information (CI), a method describing composition information of media for delivery of multimedia services over packet-based heterogeneous networks.The technologies for composition function specify the method associating content delivered in the format
30、defined in this part of ISO/IEC 23008 to the presentation and the method representing synchronization between timed and non-timed content.2 Normative referencesThe following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dat
31、ed references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.W3C HTML5, A vocabulary and associated APIs for HTML and XHTML, W3C Candidate Recommendation 17 December 20123 Symbols and abbreviated termsAU acces
32、s unitCI composition informationMMT MPEG media transportMPU media processing unitSVC scalable video codingURL uniform resource locatorURN uniform resource nameXML extensible mark-up language4 OverviewThis part of ISO/IEC 23008 defines a Composition Information (CI) layer that controls the temporal a
33、nd spatial layout of media. The composition layer is currently specified using HTML5 and XML technologies.The composition layer defines the presentation aspects of a multimedia presentation such as an MMT Package. The composition layer in this part of ISO/IEC 23008 addresses delivery of synchronizat
34、ion information of content that is composed of various content components and where multiple device screens may be used to present the content. Some parts of the content component may be replaced by others based on the context of the user, such as location or personal preferences. Presentation time
35、of INTERNATIONAL STANDARD ISO/IEC 23008-11:2015(E) ISO/IEC 2015 All rights reserved 1BS ISO/IEC 23008-11:2015ISO/IEC 23008-11:2015(E)some components may not be assigned when the content is encapsulated but needs only to be decided when the content is acutally consumed.A multimedia service may use an
36、y subset of the tools defined in this part of ISO/IEC 23008 according to their specific needs. Interfaces to other protocols and standards are either defined by this part of ISO/IEC 23008 or may be defined elsewhere.5 Composition Information5.1 IntroductionThe Composition layer provides information
37、on temporal relationships among the media content of a presentation to complement the associated HTML5 document, since the associated HTML5 document only provides initial information on spatial relationships among media elements. The composition layer also provides information on relationships betwe
38、en the media data (e.g. the MMT Assets) and possibly on how to optimally consume them on multiple screens. The Composition Information (CI) is represented as an XML document (CI document) providing descriptive representation of such temporal relationship information, thus enabling various ways to im
39、plement the composition layer (including implementations that do not use any scripts processing engine.)To support descriptive representation of temporal relationships among media data (such as MMT assets or MPUs) and mapping of media data to be consumed on multiple devices, the composition layer de
40、fines several elements and attributes as follows: Association of HTML5 media elements and media data as resources. Temporal information to presentation time of the media data. Designation of certain parts of the presentation to be presented on a particular screen in a multi-screen environment.A CI p
41、rocessing engine is responsible for fetching the CI file and the HTML5 file (and any other referenced files) and processing the CI information to control the presentation accordingly.The HTML5 file is typically parsed into a Document Object Model (DOM) tree and stored in memory. The CI processing en
42、gine applies changes to the DOM at specified time according to the information contained in the CI file. The DOM nodes/elements are referenced using their identifiers or possibly using a certain pattern (e.g. provided through jQuery selectors).Figure 1 CI Layer2 ISO/IEC 2015 All rights reservedBS IS
43、O/IEC 23008-11:2015ISO/IEC 23008-11:2015(E)5.2 Structure of the CI document5.2.1 OverviewThe CI document is defined as an XML document with the XML schema provided in Annex A. The CI document is defined with several elements referring the elements defined in the HTML5 document by their IDs as shown
44、in Figure 2.The HTML5 document shall include HTML5 media elements, which maybe any of video, audio, img, or track elements together with their associated spatial information. A reference to the CI document may be included in the HTML5 document, typically as part of the Javascript that launches the C
45、I parser. Spatial information of the media elements shall be used to present the corresponding media data (such as the MMT Assets). The body element of the HTML5 document shall include more than one spatial area (i.e. div element), if partial consumption of the presentation on multiple screens is to
46、 be allowed.To efficiently represent temporal relationships among media data to be synchronously consumed on multiple screens that are independently processing a presentation, the CI document defines in a hierarchical structure the concepts of Area and View. An Area in the CI document represents a s
47、patial region defined by a div element in the HTML5 document, which may include one or more HTML5 media elements. A View represents a set of Areas to be consumed on a single screen.Figure 2 Structure of CI document and its relationship with HTML5 documentThe CI document provides temporal information
48、 about Views, Areas and media data. The root element of CI document is the CI element, which may contain elements such as view and MediaSync element. The roles of these elements are as follows: view: provides temporal information about the spatial changes of a View and its Areas. MediaSync: provides
49、 temporal information about the presentation of media data (e.g. MMT assets). ISO/IEC 2015 All rights reserved 3BS ISO/IEC 23008-11:2015ISO/IEC 23008-11:2015(E)The initial Areas in a View are generated by the div element in the HTML5 document, and the spatial changes of the initial Areas in the View are provided by the area elements of the CI document. These two elements allow the spatial location of Areas to be dynamically changed and updated without reloading the HTML5 document.In MMT delivery, the CI data may be par
