ISO/IEC TS 30135-5:2014

TECHNICAL ISO/IEC
SPECIFICATION TS
30135-5
First edition
2014-11-15
Information technology — Digital
publishing — EPUB3 —
Part 5:
Media Overlay
Technologies de l'information — Publications numériques — EPUB3 —
Partie 5: Superposition de médias

Reference number
©
ISO/IEC 2014
©  ISO/IEC 2014
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 2014 – All rights reserved

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.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of the joint technical committee is to prepare International Standards. Draft International
Standards adopted by the joint technical committee are circulated to national bodies for voting. Publication as
an International Standard requires approval by at least 75 % of the national bodies casting a vote.
In other circumstances, particularly when there is an urgent market requirement for such documents, the joint
technical committee may decide to publish an ISO/IEC Technical Specification (ISO/IEC TS), which
represents an agreement between the members of the joint technical committee and is accepted for
publication if it is approved by 2/3 of the members of the committee casting a vote.
An ISO/IEC TS is reviewed after three years in order to decide whether it will be confirmed for a further three
years, revised to become an International Standard, or withdrawn. If the ISO/IEC TS is confirmed, it is
reviewed again after a further three years, at which time it must either be transformed into an International
Standard or be withdrawn.
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.
ISO/IEC TS 30135 series were prepared by Korean Agency for Technology and Standards (as KS X 6070
series) with International Digital Publishing Forum and were adopted, under a special “fast-track procedure”,
by Joint Technical Committee ISO/IEC JTC 1, Information technology, in parallel with its approval by the
national bodies of ISO and IEC.
ISO/IEC TS 30135 consists of the following parts, under the general title Information technology — Document
description and processing languages — EPUB 3:
—  Part 1: Overview
—  Part 2: Publications
—  Part 3: Content Documents
—  Part 4: Open Container Format
—  Part 5: Media Overlay
—  Part 6: Canonical Fragment Identifier
—  Part 7: Fixed-Layout Documents

EPUB Media Overlays 3.0
Recommended Specification 11 October 2011
THIS VERSION
http://www.idpf.org/epub/30/spec/epub30-mediaoverlays-20111011.html
LATEST VERSION
http://www.idpf.org/epub/30/spec/epub30-mediaoverlays.html
PREVIOUS VERSION
http://www.idpf.org/epub/30/spec/epub30-mediaoverlays-20110908.html
A diff of changes from the previous draft is available at this link.
Please refer to the errata for this document, which may include some normative corrections.
All rights reserved. This work is protected under Title 17 of the United States Code. Reproduction and
dissemination of this work with changes is prohibited except with the written permission of the International
Digital Publishing Forum (IDPF).
EPUB is a registered trademark of the International Digital Publishing Forum.
Editors
Marisa DeMeglio, DAISY Consortium
Daniel Weck, DAISY Consortium
TAB LE O F CO NTENTS
1. Overview
1.1. Purpose and Scope
1.2. Relationship to Other Specifications
1.3. Terminology
1.4. Conformance Statements
2. Media Overlay Document Definition
2.1. Introduction
2.2. Content Conformance
2.3. Reading System Conformance
2.4. Media Overlay Document Definition
2.4.1. The smil Element
2.4.2. The head Element
2.4.3. The metadata Element
2.4.4. The body Element
2.4.5. The seq Element
2.4.6. The par Element
2.4.7. The text Element
2.4.8. The audio Element
3. Creating Media Overlays
3.1. Overview
3.2. Relationship to the EPUB Content Document
3.2.1. Structure
3.2.2. Granularity
3.2.3. Embedded Audio and Video

3.2.4. Text-to-Speech
3.3. Semantic Inflection
3.4. Associating Style Information
3.5. Packaging
3.5.1. Including Media Overlays
3.5.2. Media Overlays Metadata Vocabulary
4. Playback Behaviors
4.1. Loading the Media Overlay
4.2. Basic Playback
4.2.1. Timing and Synchronization
4.2.2. Rendering Audio
4.2.3. Rendering EPUB Content Document Elements
4.3. Interacting with the EPUB Content Document
4.3.1. Navigation
4.3.2. Embedded Audio and Video
4.3.3. Text-to-Speech
4.4. Skippability and Escapability
4.4.1. Skippability
4.4.2. Escapability
A. Media Overlays Schema
A.1. Using the Media Overlays Schema
B. Examples of Clock Values
C. Acknowledgements and Contributors
References
› 1 Overview
› 1.1 Purpose and Scope
This section is informative
This specification, EPUB Media Overlays 3.0, defines a usage of [SMIL] (Synchronized Multimedia
Integration Language), the Package Document, the EPUB® Style Sheet, and the EPUB Content
Document for representation of audio synchronized with the EPUB Content Document.
This specification is one of a family of related specifications that compose EPUB 3, the third major
revision of an interchange and delivery format for digital publications based on XML and Web Standards. It
is meant to be read and understood in concert with the other specifications that make up EPUB 3:
The EPUB 3 Overview [EPUB3Overview], which provides an informative overview of EPUB and a
roadmap to the rest of the EPUB 3 documents. The Overview should be read first.
EPUB Publications 3.0 [Publications30], which defines publication-level semantics and
overarching conformance requirements for EPUB Publications.
EPUB Content Documents 3.0 [ContentDocs30], which defines profiles of XHTML, SVG and CSS
for use in the context of EPUB Publications.
EPUB Open Container Format (OCF) 3.0 [OCF3], which defines a file format and processing
model for encapsulating a set of related resources into a single-file (ZIP) EPUB Container.
› 1.2 Relationship to Other Specifications
This section is informative
This specification relies on a subset of [SMIL], from which the EPUB Media Overlays elements and
attributes defined in Media Overlay Document Definition are derived.
1.3 Terminology
›
EPUB Publication (or Publication)
A logical document entity consisting of a set of interrelated resources and packaged in an
EPUB Container, as defined by this specification and its sibling specifications.
Publication Resource
A resource that contains content or instructions that contribute to the logic and rendering of
the EPUB Publication. In the absence of this resource, the Publication might not render as
intended by the Author. Examples of Publication Resources include the Package Document,
EPUB Content Documents, EPUB Style Sheets, audio, video, images, embedded fonts and
scripts.
With the exception of the Package Document itself, Publication Resources must be listed in
the manifest [Publications30] and must be bundled in the EPUB container file unless
specified otherwise in Publication Resource Locations [Publications30].
Examples of resources that are not Publication Resources include those identified by the
Package Document link [Publications30] element and those identified in outbound hyperlinks
that resolve outside the EPUB Container (e.g., referenced from an [HTML5] a element href
attribute).
EPUB Content Document
A Publication Resource that conforms to one of the EPUB Content Document definitions
(XHTML or SVG).
An EPUB Content Document is a Core Media Type, and may therefore be included in the
EPUB Publication without the provision of fallbacks [Publications30].
XHTML Content Document
An EPUB Content Document conforming to the profile of [HTML5] defined in XHTML Content
Documents [ContentDocs30].
XHTML Content Documents use the XHTML syntax of [HTML5].
SVG Content Document
An EPUB Content Document conforming to the constraints expressed in SVG Content
Documents [ContentDocs30].
EPUB Navigation Document
A specialization of the XHTML Content Document, containing human- and machine-readable
global navigation information, conforming to the constraints expressed in EPUB Navigation
Documents [ContentDocs30].
Core Media Type
A set of Publication Resource types for which no fallback is required. Refer to Publication
Resources [Publications30] for more information.
Package Document
A Publication Resource carrying bibliographical and structural metadata about the EPUB

Publication, as defined in Package Documents [Publications30].
Manifest
A list of all Publication Resources that constitute the EPUB Publication.
Refer to manifest [Publications30] for more information.
Spine
An ordered list of Publication Resources, typically EPUB Content Documents, representing
the default reading order of the Publication.
Refer to spine [Publications30] for more information.
Media Overlay Document
An XML document that associates the XHTML Content Document with pre-recorded audio
narration in order to provide a synchronized playback experience, as defined in this
specification.
Text-to-Speech (TTS)
The rendering of the textual content of an EPUB Publication as artificial human speech using
a synthesized voice.
EPUB Style Sheet (or Style Sheet)
A CSS Style Sheet conforming to the CSS profile defined in EPUB Style Sheets
[ContentDocs30].
Viewport
The region of an EPUB Reading System in which the content of an EPUB Publication is
rendered visually to a User.
CSS Viewport
A Viewport capable of displaying CSS-styled content.
EPUB Container (or Container)
The ZIP-based packaging and distribution format for EPUB Publications defined in [OCF3].
Author
The person(s) or organization responsible for the creation of an EPUB Publication, which is
not necessarily the creator of the content and resources it contains.
User
An individual that consumes an EPUB Publication using an EPUB Reading System.
EPUB Reading System (or Reading System)
A system that processes EPUB Publications for presentation to a User in a manner
conformant with this specification and its sibling specifications.
› 1.4 Conformance Statements
The keywords "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD
NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described
in [RFC2119].
All sections of this specification are normative except where identified by the informative status label
"This section is informative". The application of informative status to sections and appendices applies to
all child content and subsections they may contain.
All examples in this specification are informative.
› 2 Media Overlay Document Definition
› 2.1 Introduction
This section is informative
Books featuring synchronized audio narration are found in mainstream e-books, educational tools and e-
books formatted for persons with print disabilities. In EPUB 3, these types of books are created by using
Media Overlay Documents to describe the timing for the pre-recorded audio narration and how it relates to
the EPUB Content Document markup. The file format for Media Overlays is defined as a subset of SMIL,
a W3C recommendation for representing synchronized multimedia information in XML.
The Media Overlays feature is designed to be transparent to EPUB Reading Systems that do not support
the feature. The inclusion of Media Overlays in an EPUB Publication has no impact on the ability of
Media Overlay-unaware Reading Systems to render that Publication as a "regular" EPUB Publication.
Although future versions of this specification may incorporate support for video media (e.g., synchronized
text/sign-language books), this version supports only synchronizing audio media with the EPUB Content
Document.
› 2.2 Content Conformance
A Media Overlay Document must meet all of the following criteria:
Document Properties
› It must meet the conformance constraints for XML documents defined in XML Conformance
[Publications30].
› It must be valid to the Media Overlays schema as defined in Appendix A, Media Overlays
Schema and conform to all content conformance constraints expressed in Media Overlay
Document Definition.
› It must be authored to reflect the structure of the EPUB Content Document with which it is
associated, as stated in Structure .
› Authors should avoid using scripts to control audio and video embedded in the EPUB Content
Document, as stated in Embedded Audio and Video.
› It should use semantic markup where appropriate, as described in Semantic Inflection.
› It must be packaged with the EPUB Publication as shown in Packaging.
File Properties
› The Media Overlay Document filename should use the file extension .smil.
› 2.3 Reading System Conformance

EPUB Reading System support for Media Overlays is optional. A Reading System that supports Media
Overlays must meet the following criteria:
› It must process the Media Overlay Document in conformance with all Reading System
conformance constraints expressed in Media Overlay Document Definition.
› It must support XHTML Content Documents, and it may support SVG Content Documents.
› It must render Media Overlay elements as describe
...