ISO/IEC 23008-11:2015
(Main)Information technology — High efficiency coding and media delivery in heterogeneous environments — Part 11: MPEG media transport composition information
Information technology — High efficiency coding and media delivery in heterogeneous environments — Part 11: MPEG media transport composition information
ISO/IEC 23008-11:2015 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 defined in this part of ISO/IEC 23008 to the presentation and the method representing synchronization between timed and non-timed content.
Technologies de l'information — Codage à haute efficacité et livraison des medias dans des environnements hétérogènes — Partie 11: Informations de composition pour le transport des medias MPEG
General Information
Relations
Standards Content (Sample)
INTERNATIONAL ISO/IEC
STANDARD 23008-11
First edition
2015-04-01
Information technology — High
efficiency coding and media delivery
in heterogeneous environments —
Part 11:
MPEG Media Transport Composition
Information
Technologies de l’information — Codage à haute efficacité et livraison
des medias dans des environnements hétérogènes —
Partie 11: Informations de composition pour le transport des medias
MPEG
Reference number
ISO/IEC 23008-11:2015(E)
©
ISO/IEC 2015
---------------------- Page: 1 ----------------------
ISO/IEC 23008-11:2015(E)
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
or 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 ISO’s member body in the country of
the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.org
Web www.iso.org
Published in Switzerland
ii © ISO/IEC 2015 – All rights reserved
---------------------- Page: 2 ----------------------
ISO/IEC 23008-11:2015(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Symbols and abbreviated terms . 1
4 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 attribute . 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
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
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 reserved iii
---------------------- Page: 3 ----------------------
ISO/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 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, governmental 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
described 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 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 the 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
assessment, as well as information about ISO’s 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, picture, 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 Audio
— 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 guidelines
iv © ISO/IEC 2015 – All rights reserved
---------------------- Page: 4 ----------------------
ISO/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 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 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 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
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. 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 presentation 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 v
---------------------- Page: 5 ----------------------
INTERNATIONAL STANDARD ISO/IEC 23008-11:2015(E)
Information technology — High efficiency coding and
media delivery 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 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 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 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 language
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 presentation 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 be replaced by
others based on the context of the user, such as location or personal preferences. Presentation time of
© ISO/IEC 2015 – All rights reserved 1
---------------------- Page: 6 ----------------------
ISO/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 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/IEC 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 information 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 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 media 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.
— 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 accordingly.
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 possibly using
a certain pattern (e.g. provided through jQuery selectors).
Figure 1 — CI Layer
2 © ISO/IEC 2015 – All rights reserved
---------------------- Page: 7 ----------------------
ISO/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 Annex 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 information. 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 document 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 presentation, 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 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 these 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 3
---------------------- Page: 8 ----------------------
ISO/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 partitioned into multiple subsets that reference each other using
the XLink framework and where each subset of the CI may be delivered separately for example by using
the MPI signaling message (see ISO/IEC 23008-1 sub-clause 5.3.8 and 5.3.9).
Figure 3 shows an example representing the relationship among media data (MMT assets), Areas and View.
View
Area 1 Area 2
Asset
Asset
(Audio)
(Video)
Asset
(Image)
Asset
(Caption)
Area 3
Asset
(Text)
Figure 3 — Example of Asset/Area/View
CI uses the timing and synchronization module of SMIL [W3C SMIL 3.0]. For CI consumption the timing
and synchronization module shall be supported.
5.3 The attributes of a CI document
5.3.1 The begin attribute
The begin attribute indicates when the corresponding command has to be performed by the user agent,
e.g. when particular media data needs to be rendered by an HTML5 media element or when a change to
the spatial layout of the presentation has to be performed. The begin attribute is defined in section 5.4.3
of [W3C SMIL3.0]. All defined syncbases defined by [W3C SMIL 3.0] shall be supported.
5.3.2 The end attribute
The end attribute indicates when the corresponding CI action shall end. For media data it indicates when
the media data playback stops. When the parent element is a view element, the agent shall completely
remove the referenced div element from the DOM at the indicated end time. When not present for media
data, the end time shall be the time when the playback of the media data ends. The end attribute is
defined in section 5.4.3 of [W3C SMIL3.0].
5.3.3 The dur attribute
The dur attribute indicates the duration of the corresponding action, which is equivalent to the end time
– the begin time. The dur attribute shall not be present when the corresponding action is about spatial
layout. The dur attribute is defined in section 5.4.3 of [W3C SMIL3.0].
4 © ISO/IEC 2015 – All rights reserved
---------------------- Page: 9 ----------------------
ISO/IEC 23008-11:2015(E)
5.3.4 The clipBegin attribute
The clipBegin attribute indicates the beginning of a time interval of a continuous media element by offset
from the start of the media resource. The clipBegin attribute is defined in section 4.8.1 of [W3C SMIL3.0].
For example, a clipBegin=”10s” attribute would indicate that the first 10 seconds of the media resource
will not be played back.
5.3.5 The clipEnd attribute
The clipEnd attribute indicates the end of a time interval of a continuous media element by offset from
the start of the media. The clipEnd attribute is defined in section 4.8.1 of [W3C SMIL3.0].
5.3.6 The refDiv attribute
The refDiv attribute describes an ID of div element, which is used for linking to its area element. If the
referenced div element is not present in the HTML5, then a new div element is created and added to the
DOM at the indicated begin time.
5.3.7 The style attribute
The style attribute shall be used to indicate any spatial layout or style modifications to the referenced
div element. The style attribute shall conform to the CSS Style Attributes.
5.3.8 The xlink:href attributes
The xlink:href attribute provides the data that allows an XLink application to find a subset of CI data.
The value of the href attribute shall be an URI reference as defined in [RFC 2396] and shall be provided.
5.3.9 The xlink:actuate attributes
The xlink:actuate attribute defines the desired timing of traversal linked resources. If a value is supplied
for an actuate attribute, it must be one of following values.
— onLoad: linking a subset of CI data immediately on loading of the current CI document.
— onRequest: linking a subset of CI data when they are available or on user request (on-demand).
5.3.10 The viewRole attributes
The viewRole attribute indicates the role of the view element. Several view elements can be contained in
one CI document, and this attribute can be used to distinguish each of them. The following table defines
the meaning of the possible values for the viewRole attribute.
Table 1 — the viewRole for multi-screen presentation
Value Description
Indicates that this view is meant to be consumed on the main screen without required
Default
interaction with other screens.
Multiple Indicates that the view is meant to be consumed in a multi-screen environment.
Indicates that the view is a placeholder to be used to receive content in a multi-screen
Receptible
presentation.
5.3.11 The isDependent attributes
The isDependent attribute indicates whether the media element depends on another media element or
not, in order to be properly decoded and presented. If the isDependent attribute is “true”, the media
element depends on other media elements that are listed in depId.
© ISO/IEC 2015 – All rights reserved 5
---------------------- Page: 10 ----------------------
ISO/IEC 23008-11:2015(E)
5.3.12 The depId attributes
The depId attribute is a whitespace-separated list of refId of media elements on which the current media
element depends on. The depId attribute exists if and only if the isDependent attribute is set to “true”.
5.3.13 The refId attribute
The refId attribute identifies a media element (video, audio, img, track, object element of [W3C
HTML5]). This attribute is used for linking with a MediaSync element.
5.3.14 The mediaSrc attribute
The mediaSrc attribute indicates the address of media data (e.g. a particular MPU of an MMT Asset). The
mediaSrc attribute MAY also refer to an MPD. When an MPD is referenced the MPD@availabilityStartTime
shall be ignored and the time defined in the begin attribute is used instead to determine when to start
playback of the Presentation. When the mediaSrc attribute refers an MMT MPU, the URL format is
provided in ISO/IEC 23009-1.
6 © ISO/IEC 2015 – All rights reserved
---------------------- Page: 11 ----------------------
ISO/IEC 23008-11:2015(E)
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.