1、BSI Standards Publication BS ISO/IEC 23008-11:2015 Information technology High efficiency coding and media delivery in heterogeneous environments Part 11: MPEG Media Transport Composition InformationBS ISO/IEC 23008-11:2015 BRITISH STANDARD National foreword This British Standard is the UK implement
2、ation of ISO/IEC 23008-11:2015. The UK participation in its preparation was entrusted to Technical Committee IST/37, Coding of picture, audio, multimedia and hypermedia information. A list of organizations represented on this committee can be obtained on request to its secretary. This publication do
3、es not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. The British Standards Institution 2015. Published by BSI Standards Limited 2015 ISBN 978 0 580 84993 0 ICS 35.040 Compliance with a British Standard cannot confer immunity from le
4、gal obligations. This British Standard was published under the authority of the Standards Policy and Strategy Committee on 30 April 2015. Amendments issued since publication Date Text affectedBS ISO/IEC 23008-11:2015 Information technology High efficiency coding and media delivery in heterogeneous e
5、nvironments Part 11: MPEG Media Transport Composition Information Technologies de linformation Codage haute efficacit et livraison des medias dans des environnements htrognes Partie 11: Informations de composition pour le transport des medias MPEG INTERNATIONAL STANDARD ISO/IEC 23008-11 Reference nu
6、mber ISO/IEC 23008-11:2015(E) First edition 2015-04-01 ISO/IEC 2015 BS ISO/IEC 23008-11:2015ii ISO/IEC 2015 All rights reserved COPYRIGHT PROTECTED DOCUMENT ISO/IEC 2015 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form o
7、r by any means, electronic or mechanical, 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 office Case postale 56 CH
8、-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Switzerland ISO/IEC 23008-11:2015(E)BS ISO/IEC 23008-11:2015ISO/IEC 23008-11:2015(E)Foreword iv Introduction v 1 Scope . 1 2 Normative references 1 3 Symbols and abbreviated terms . 1 4
9、Overview . 1 5 Composition Information 2 5.1 Introduction 2 5.2 Structure of the CI document . 3 5.2.1 Overview . 3 5.3 The attributes of a CI document . 4 5.3.1 The begin attribute . 4 5.3.2 The end attribute 4 5.3.3 The dur attribute . 4 5.3.4 The clipBegin attribute . 5 5.3.5 The clipEnd attribut
10、e 5 5.3.6 The refDiv attribute 5 5.3.7 The style attribute 5 5.3.8 The xlink:href attributes 5 5.3.9 The xlink:actuate attributes . 5 5.3.10 The viewRole attributes 5 5.3.11 The isDependent attributes 5 5.3.12 The depId attributes . 6 5.3.13 The refId attribute . 6 5.3.14 The mediaSrc attribute . 6
11、5.3.15 The obsolete attribute 7 5.3.16 The obsoleteTime attribute. 7 5.4 The elements of a CI document 8 5.4.1 The CI element . 8 5.4.2 The reference element 8 5.4.3 The view element 9 5.4.4 The area element 10 5.4.5 The MediaSync element 11 5.4.6 The sourceList element .12 6 HTML data attributes 12
12、 6.1 Introduction .12 6.2 Attributes 12 6.2.1 data-version attribute 12 6.2.2 data-ci attribute .12 7 Update Mechanism 13 7.1 Introduction .13 Annex A (informative) XML Schema of Composition Information 14 Annex B (informative) Examples of CI document .17 Bibliography .34 ISO/IEC 2015 All rights res
13、erved iii Contents PageBS ISO/IEC 23008-11:2015ISO/IEC 23008-11:2015(E) Foreword ISO (the 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
14、participate in the development of International Standards through technical committees established 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, govern
15、mental 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 technical committee, ISO/IEC JTC 1. The procedures used to develop this document and those intended for its further maintenance are descr
16、ibed in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed 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
17、 possibility that some of the elements of this document may be the subject of patent rights. 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 t
18、he ISO list of patent declarations received (see www.iso.org/patents). Any trade name used in 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 assessme
19、nt, as well as information about ISOs adherence to the WTO principles in the Technical Barriers 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, pictur
20、e, multimedia and hypermedia information. ISO/IEC 23008 consists of the following parts, under 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 A
21、udio Part 5: HEVC Conformance testing and reference software Part 8: Confomance Specification 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
22、2015 All rights reservedBS ISO/IEC 23008-11:2015ISO/IEC 23008-11:2015(E) Introduction This part 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
23、and unidirectional digital broadcasting networks. In this part of ISO/IEC 23008, “coded media data” 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
24、 an arbitrary time based on the context of the service or the user interaction. MMT is designed under 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
25、 non-constant end-to-end delivery delay of each packet from the sending entity to the receiving entity 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
26、 networks, this part of ISO/IEC 23008 provides the following elements: logical model to construct content 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.
27、 packetization and adaptation); packetization method and the structure of the packet to deliver media 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 presen
28、tation and delivery of media content; format of information to be exchanged across layers of the delivery 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 deliver
29、y in heterogeneous environments Part 11: MPEG Media Transport Composition Information 1 Scope This part 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
30、 technologies for composition function specify the method associating content delivered in the format defined in this part of ISO/IEC 23008 to the presentation and the method representing synchronization between timed and non-timed content. 2 Normative references The following documents, in whole or
31、 in part, are normatively referenced in this document and are indispensable for its application. For dated 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
32、 for HTML and XHTML, W3C Candidate Recommendation 17 December 2012 3 Symbols and abbreviated terms AU access unit CI composition information MMT MPEG media transport MPU media processing unit SVC scalable video coding URL uniform resource locator URN uniform resource name XML extensible mark-up lang
33、uage 4 Overview This part of ISO/IEC 23008 defines a Composition Information (CI) layer that controls the temporal and 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 presen
34、tation such as an MMT Package. The composition layer in this part of ISO/IEC 23008 addresses delivery of synchronization 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
35、 be replaced by others based on the context of the user, such as location or personal preferences. Presentation time of INTERNATIONAL ST ANDARD 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 con
36、tent is encapsulated but needs only to be decided when the content is acutally consumed. A multimedia service may use any 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/IE
37、C 23008 or may be defined elsewhere. 5 Composition Information 5.1 Introduction The Composition layer provides information on temporal relationships among the media content of a presentation to complement the associated HTML5 document, since the associated HTML5 document only provides initial inform
38、ation on spatial relationships among media elements. The composition layer also provides information on relationships between 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
39、 document) providing descriptive representation of such temporal relationship information, thus enabling various ways to implement the composition layer (including implementations that do not use any scripts processing engine.) To support descriptive representation of temporal relationships among me
40、dia data (such as MMT assets or MPUs) and mapping of media data to be consumed on multiple devices, the composition layer defines 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.
41、Designation of certain parts of the presentation to be presented on a particular screen in a multi- screen environment. A CI processing 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 acc
42、ordingly. The HTML5 file is typically parsed into a Document Object Model (DOM) tree and stored in memory. The CI processing engine 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 pos
43、sibly using a certain pattern (e.g. provided through jQuery selectors). Figure 1 CI Layer2 ISO/IEC 2015 All rights reservedBS ISO/IEC 23008-11:2015ISO/IEC 23008-11:2015(E) 5.2 Structure of the CI document 5.2.1 Overview The CI document is defined as an XML document with the XML schema provided in An
44、nex A. The CI document is defined with several elements referring the elements defined in the HTML5 document by their IDs as shown 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 inform
45、ation. A reference to the CI document may be included in the HTML5 document, typically as part of the Javascript that launches the CI 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 docume
46、nt shall include more than one spatial area (i.e. div element), if partial consumption of the presentation on multiple screens is to be allowed. To efficiently represent temporal relationships among media data to be synchronously consumed on multiple screens that are independently processing a prese
47、ntation, the CI document defines in a hierarchical structure the concepts of Area and View. An Area in the CI document represents a spatial 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
48、single screen. Figure 2 Structure of CI document and its relationship with HTML5 document The CI document provides temporal information 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 th
49、ese elements are as follows: view: provides temporal information about the spatial changes of a View and its Areas. MediaSync: provides 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
