Abstract: This standard defines the format and content of the electronic file set that comprises a digital talking book (DTB) and establishes a limited set of requirements for DTB playback devices. It uses established and new specifications to delineate the structure of DTBs whose content can range from XML text only, to text with corresponding spoken audio, to audio with little or no text. DTBs are designed to make print material accessible and navigable for blind or otherwise print-disabled persons.
An American National Standard Developed by the National Information Standards Organization
Approved March 6, 2002, by the American National Standards Institute
Published by
NISO Press
4733 Bethesda Avenue, Suite 300
Bethesda, MD 20814
www.niso.org
Copyright ©2002 by the National Information Standards Organization.
All rights reserved under international and Pan-American Copyright
Conventions. For noncommercial purposes only this publication may be
reproduced or transmitted in any form or by any means without prior
permission in writing from the publisher. All inquiries regarding
commercial reproduction or distribution should be addressed to NISO
Press, 4733 Bethesda Avenue, Suite 300, Bethesda, MD 20814 USA.
ISSN: 1041-5653 National Information Standards Series
ISBN: 1-880124-52-1
(This foreword is not a part of ANSI/NISO Z39.86-2002, Specifications for the Digital Talking Book. It is included for information only.)
This standard presents specifications for digital talking books (DTBs) for blind, visually impaired, physically handicapped, learning-disabled, or otherwise print-disabled readers. For many years, "talking books" have been made available to print-disabled readers on analog media such as phonograph records and audiocassettes. These media serve their users well in providing human-speech recordings of a wide array of print material in increasingly robust and cost-effective formats. However, analog media are limited in several respects when compared to a print book. First, they are by their nature linear presentations, which leave much to be desired when reading reference works, textbooks, magazines, and other materials that are often accessed randomly. In contrast, digital media offer readers the ability to move around in a book or magazine as freely as (and more efficiently than) a sighted reader flips through a print book. Second, analog recordings do not allow users to interact with the book by placing bookmarks or highlighting material. A DTB offers this capability, storing the bookmarks and highlights separate from, but associated with, the DTB itself. Third, talking book users have long complained that they do not have access to the spelling of the words they hear. As will be explained below, some DTBs will include a file containing the full text of the work, synchronized with the audio presentation, thereby allowing readers to locate specific words and hear them spelled. Finally, analog audio offers readers only one version of the document. If, for example, a book contains footnotes, they are either read where referenced, which burdens the casual reader with unwanted interruptions, or grouped at a location out of the flow of the text, making them difficult for interested readers to access. A DTB allows the user to easily skip over or read footnotes. The Digital Talking Book offers the print-disabled user a significantly enhanced reading experience -- one that is much closer to that of the sighted reader using a print book.
The DTB goes far beyond the limits imposed on analog audio books because it can include not just the audio rendition of the work, but the full textual content and images as well. Because the textual content file is synchronized with the audio file, a DTB offers multiple sensory inputs to readers, a great benefit to, for example, learning-disabled readers. Some visually impaired readers may choose to listen to most of the book, but find that inspecting the images provides information not available in the narrative flow. Others may opt to skip the audio presentation altogether and instead view the text file via screen-enlarging software. Braille readers may prefer to read some or all of the document via a refreshable Braille display device connected to their DTB player and accessing the textual content file.
Digital Talking Books are not tied to a single distribution medium. CD-ROMs will be used first but DTBs will be portable to any digital distribution medium capable of handling the large files associated with digital audio recordings. Regardless of how a DTB is distributed, however, it will normally be in the context of a digital rights management system.
This standard describes the various files that make up a DTB and specifies how each must be formatted. The initiative behind this document grew from a desire to standardize DTB file structures in the hope that it might prevent a recurrence of the multiple formats currently used for talking books throughout the world. This document benefited greatly from the work of the DAISY Consortium, whose members had broken much of the ground covered in this standard and who contributed enormously to the solution of the many problems encountered.
3M
Jerry Karel
Susan Boettcher (Alt)
American Association of Law Libraries
Robert L. Oakley
Mary Alice Baish (Alt)
American Chemical Society
Robert S. Tannehill, Jr.
American Library Association
Paul J. Weiss
American Society for Information Science and Technology
Mark H. Needleman
American Society of Indexers
Judith Gibbs
Jacqueline Rodebaugh (Alt)
American Theological Library Association
Myron Chace
ARMA International
Diane Carlisle
Armed Forces Medical Library
Diane Zehnpfennig
Emily Court (Alt)
Art Libraries Society of North America
David L. Austin
AIIM International
Betsy A. Fanning
Association of Jewish Libraries
Caroline R. Miller
Elizabeth Vernon (Alt)
Association of Research Libraries
Duane E. Webster
Julia Blixrud (Alt)
BiblioMondo Inc.
Martin Sach
Book Industry Communication
Brian Green
Cambridge Scientific Abstracts
Michael Cairns
Matthew Dunie (Alt)
Checkpoint Systems, Inc.
Paul Simon
College Center for Library Automation
J. Richard Madaus
Ann Armbrister (Alt)
Congressional Information Service, Inc.
Robert Lester
devine, Inc.
Robert Boissy
Elsevier Science
Anthony Ross
John Mancia (Alt)
Endeavor Information Systems, Inc.
Verne Coppi
Cindy Miller (Alt)
epixtech, Inc.
John Bodfish
Ricc Ferante (Alt)
Ex Libris
James Steenbergen
Carl Grant (Alt)
Follett Corporation
D. Jeffrey Blumenthal
Don Rose (Alt)
Fretwell-Downing Informatics
Robin Murray
Gale Group
Katherine Gruber
Justine Carson (Alt)
Gaylord Information Systems
William Schickling
Linda Zaleski (Alt)
GCA Research Institute
Jane Harnad
H.W. Wilson Company
Ann Case
Information Use Management & Policy Institute
Charles McClure
John Carlo Bertot (Alt)
Infotrieve
Jan Peterson
Innovative Interfaces, Inc.
Gerald M. Kline
Sandy Westall (Alt)
Institute for Scientific Information
The International DOI Foundation
Norman Paskin
Library Binding Institute
Donald Dunham
The Library Corporation
Mark Wilson
Nancy Capps (Alt)
Library of Congress
Winston Tabb
Sally H. McCallum (Alt)
Los Alamos National Laboratory
Richard E. Luce
Lucent Technologies
M.E. Brennan
Medical Library Association
Nadine P. Ellero
Carla J. Funk (Alt)
MINITEX
Cecelia Boone
William DeJohn (Alt)
Modern Language Association
Daniel Bokser
Cameron Bardrick (Alt)
Motion Picture Association of America
William M. Baker
Axel aus der Muhlen (Alt)
Music Library Association
Lenore Coral
Mark McKnight (Alt)
National Agricultural Library
Gary K. McCone
National Archives and Records Administration
Mary Ann Hadyka
National Federation of Abstracting and Information Services
Marion Harrell
National Library of Medicine
Betsy L. Humphreys
Nylink
Mary-Alice Lynch
Jane Neale (Alt)
OASIS
OCLC, Inc.
Donald J. Muccino
Openly Informatics
Eric Hellman (Alt)
Proquest Information and Learning
Todd Fegan
James Brei (Alt)
Recording Industry Association of America
Linda R. Bocchi
Michael Williams (Alt)
Research Libraries Group
Lennie Stovel
Joan Aliprand (Alt)
SIRS Mandarin, Inc.
Leonardo Lazo
Harry Kaplanian (Alt)
Sirsi Corporation
Greg Hathorn
Slavko Manojlovich (Alt)
Society for Technical Communication
Annette Reilly
Kevin Burns (Alt)
Society of American Archivists
Lisa Weber
Special Libraries Association
Marcia Lei Zeng
Triangle Research Libraries Network
Jordan M. Scepanski
Mona C. Couts (Alt)
U.S. Department of Commerce
National Institute of Standards and Technology
Office of Information Services
U.S. Department of Defense
Defense Technical Information Center
Gopalakrishnan Nair
Jane L. Cohen (Alt)
U.S. National Commission on Libraries and Information Science
Denise Davis
VTLS Inc.
Vinod Chachra
At the time NISO approved this standard, the following individuals served on its Board of Directors:
Beverly P. Lynch, Chair
University of California, Los Angeles
Jan Peterson, Vice Chair/Chair-Elect
Infotrieve, Inc.
Donald J. Muccino, Immediate Past Chair
OCLC, Inc.
Jan Peterson, Treasurer
Infotrieve, Inc.
Patricia R. Harris, Executive Director
National Information Standards Organization
Pieter S. H. Bolman
Elsevier Science
Priscilla Caplan
Florida Center for Library Automation
Carl Grant
Ex Libris (USA), Inc.
Brian Green
BIC/EDItEUR
Jose-Marie Griffiths
University of Pittsburgh
Richard E. Luce
Los Alamos National Laboratory
Sally McCallum
Library of Congress
Norman Paskin
The International DOI Foundation
Steven Puglia
U.S. National Archives and Records Administration
Albert Simmonds
OCLC, Inc.
Standards Committee AQ on Digital Talking Books had the following members at the time this standard was approved:
Mr. Donald J. Breda
American Council of the Blind
Mr. George Brummell
Blinded Veterans Association
Mr. John Bryant
National Library Service for the Blind and Physically Handicapped
Library of Congress
Mr. Glen Cavanaugh
Telex Communications, Inc.
Mr. Curtis Chong
World Blind Union
Mr. Thomas Kjellberg Christensen
DAISY Consortium and the Danish National Library for
the Blind
Mr. John Cookson
National Library Service for the Blind and Physically Handicapped
Library of Congress
Mr. Keith Creasy
American Printing House for the Blind
Mr. Frank Kurt Cylke
National Library Service for the Blind and Physically Handicapped
Library of Congress
Mr. Jack Decker
American Printing House for the Blind
Dr. Judith Dixon
National Library Service for the Blind and Physically Handicapped
Library of Congress
Mr. Jim Dust
Telex Communications, Inc.
Dr. Michael Gosse
National Federation of the Blind
Mr. Luis Gutierrez
American Foundation for the Blind
Mr. Mark Hakkinen
Japanese Society for the Rehabilitation of Persons with Disabilities
Mr. John Hedges
American Printing House for the Blind
Ms. Vivian Seki
Hadley School for the Blind
Ms. Rosemary Kavanagh
Canadian National Institute for the Blind
Mr. George Kerscher
Recording for the Blind and Dyslexic and DAISY Consortium
Mr. Wells "Brad" Kormann
National Library Service for the Blind and Physically Handicapped
Library of Congress
Ms. Kathie Korpolinski
Recording for the Blind and Dyslexic
Mr. Dominic Labbé
VisuAide, Inc.
Ms. Mary-Frances Laughton
Assistive Devices Industry Office
Industry Canada
Mr. Thomas McLaughlin
National Library Service for the Blind and Physically Handicapped
Library of Congress
Mr. Michael Moodie, Chair
National Library Service for the Blind and Physically Handicapped
Library of Congress
Ms. Freddie Peaco
National Library Service for the Blind and Physically Handicapped
Library of Congress
Mr. Gilles Pepin
VisuAide, Inc.
Mr. Lloyd Rasmussen
National Library Service for the Blind and Physically Handicapped
Library of Congress
Ms. Janina Sajka
American Foundation for the Blind
Mr. Rudy Savage
Talking Book Publishers, Inc.
Mr. Larry Skutchan
American Printing House for the Blind
Ms. Linda Stetson
Association of Specialized and Cooperative Library Agencies
American Library Association
Mr. George Stockton
National Library Service for the Blind and Physically Handicapped
Library of Congress
Ms. Karen Taylor
Canadian National Institute for the Blind
Standards Committee AQ gratefully acknowledges the contributions made by the DAISY Consortium (www.daisy.org) to this work. The Consortium created a series of open international specifications (DAISY 2.0 ©1998, DAISY 2.01 ©1999, and DAISY 2.02 ©2001) that formed the foundation on which this standard is built. DAISY representatives served on Committee AQ since its inception and knowledge gained in their work on DAISY projects greatly informed the complex discussions and decisions leading to the creation of this document. In addition, they hosted several list-servs on which many issues critical to DTB work in general, and to this standard specifically, were discussed and resolved. It is no exaggeration to state that without their groundbreaking efforts and their ongoing contributions to Committee work, this standard would not exist in anything like its current level of sophistication.
In addition, the Committee wishes to thank the following individuals for their substantial assistance to the process of creating the standard: Robert Berkovitz, Sensimetrics Corporation; Harvey Bingham; Mike Brown; John Churchill, Recording for the Blind and Dyslexic; Manon Gaudet, VisuAide, Inc.; Al Gilman; Markus Gylling, Swedish Library of Talking Books and Braille; Steve Jacobs, NCR Corporation; Lynn Leith, Canadian National Institute for the Blind; Tatsu Nishizawa, Plextor Corporation; Dave Pawson, Royal National Institute for the Blind; James Pritchett, Recording for the Blind and Dyslexic; Dr. Gregg Vanderheiden, TRACE Research and Development Center, University of Wisconsin; Mr. Paul Vassallo, National Institute of Standards & Technology; with special thanks to members of the DAISY Consortium's Specifications and Guidelines Work Team and DTD Work Team. Thanks also to these members of the W3C Synchronized Multimedia (SYMM) Working Group: Dick Bulterman, Oratrix; Wo Chang, NIST; Lloyd Rutledge, CWI; Patrick Schmitz, Microsoft.
This standard establishes specifications for digital talking books (DTBs) for blind, visually impaired, physically handicapped, learning-disabled, or otherwise print-disabled readers. Its purpose is to ensure interoperability across service organizations and vendors providing content and playback systems to the target population.
This standard provides specifications primarily for DTB files and their interrelationships. It also includes specifications for DTB playback devices in two areas: player performance related to file requirements and player behavior in areas defined in user requirements.
The following abbreviations, acronyms, phrases, and terms are used in this standard as defined below. In the following definitions and throughout the standard, bracketed items correspond to entries in section 17, "References to Other Specifications/Documents," where the full URL is provided for each reference.
This standard is based primarily on a variety of widely used standards and specifications, including several from the World Wide Web Consortium and the Open eBook Forum™. Wherever applicable and appropriate standards or specifications existed they were used. The use of these specifications and technologies is intended to promote a fast and consistent adoption of this standard for the target population, while encouraging its extension into mainstream use.
Digital Talking Book files, streams, transformation processes, and players have been designed to present their content to people with a wide range of abilities and disabilities. They are designed to allow presentation in forms other than conventional print, due to the inaccessibility of printed documents to these users. It is in the best interest of users that, to the greatest extent possible, files, streams, transformation processes, and players make information available in as many presentation modes as practical, including human-narrated audio, Braille, synthesized speech, large print with user-specifiable size and text re-wrapping for players with visual display, and text and audio synchronization and other enhancements for persons with learning disabilities. Users will also be greatly benefited if controls on players are readily usable by people with a wide range of manual dexterity.
During the development of this standard, an advisory document, DTB Playback Device Features List, was created. Although it is not a normative part of this standard, player developers will find useful accessibility concepts embodied in it.
In addition to the provisions of this standard, valuable supplemental information is available from the guidelines and techniques produced by the Worldwide Web Consortium's Web Accessibility Initiative. At this time, these documents include:
Not all modes of presentation will be available in all players and documents, but it is strongly recommended that multiple equivalent presentations be made available to users whenever possible. Historically, products marketed to specific user groups with disabilities have sometimes proven unusable. Not all players need to be accessible to all target groups, but any device compliant with this standard must be accessible to the target group for which it is advertised. It is also strongly recommended that DTB production tools and processes be made accessible to persons with disabilities.
This standard is based on the specific versions of the standards and specifications referenced herein, which are used as defined except as noted by this document. Any refinement or replacement of a referenced specification by a newer or different version is not directly applicable to this standard. Conformance to this standard is based on the versions of the standards and specifications in effect at the time of this writing.
Playback systems must support at least UTF-8 and UTF-16 encodings. See section 2.2 of the XML specification [XML].
Implementation of this standard may involve the use of one or more inventions covered by patent rights. It is believed that all companies claiming such rights have agreed to grant a license under such rights as they hold on reasonable and nondiscriminatory terms and conditions to any applicant.
Producers of DTB systems or any component thereof are responsible for obtaining the appropriate licenses for any and all technology they use that is defined by the relevant standards and specifications referenced by this standard. There may be applicable patents of which this standards committee is unaware; it is the responsibility of the implementer to ensure that the implementation is non-infringing.
Issues surrounding the protection of intellectual property embodied in the works distributed as digital talking books are discussed in section 14, "Digital Rights Management".
The maintenance agency designated in Appendix 7 will be responsible for reviewing and acting upon suggestions for modifications to this standard. Questions concerning the implementation of this standard and requests for information should be sent to the maintenance agency.
A list of errata relating to this standard will be maintained at http://www.loc.gov/nls/z3986/v100/errata.html.
A digital talking book (DTB) is a collection of electronic files arranged to present information to the target population via alternative media, namely, human or synthetic speech, refreshable Braille, or visual display, e.g., large print. When these files are created and assembled into a DTB in accordance with this standard, they make possible a wide range of features such as rapid, flexible navigation; bookmarking and highlighting; keyword searching; spelling of words on demand; and user control over the presentation of selected items (e.g., footnotes, page numbers, etc.). Such features enable readers with visual and physical disabilities to access the information in DTBs flexibly and efficiently, and allow sighted users with learning or reading disabilities to receive the information through multiple senses. For a full discussion of these capabilities, see the "Document Navigation Features List" [Navigation Features], the user requirements document on which this standard was based. A document written during the development of this standard, Theory Behind the DTBook DTD [DTBook Theory], also describes the navigational capabilities of a DTB in some detail. The content of DTBs will range from audio alone, through a combination of audio, text, and images, to text alone. Section 13 describes these various types of DTBs.
DTB players will also be produced with a variety of capabilities. The simplest might be portable devices with audio-only capabilities. More complex portable players could include text-to-speech capabilities as well as audio output for recorded human speech. The most comprehensive playback systems are expected to be PC-based, supporting visual and audio output, text-to-speech capability, and output to a Braille display. The Playback Device Features List [Player Features] mentioned above presents the committee's priorities for a range of functions across three types of playback devices.
The files comprising a DTB fall into ten categories, as described below:
The Package File, drawn from the Open eBook Forum™ (OEBF) Publication Structure 1.0.1, contains administrative information about the DTB, the files that comprise it, and how these files interrelate. This section, drawn largely from the Publication Structure, provides only a brief summary of the function of each section with an example illustrating how it is applied to the DTB. See section 2 of the full OEBF Publication Structure 1.0.1 for complete details on the Package File.
The Publication Structure describes the major parts of the Package File as follows:
- PACKAGE IDENTITY - a unique identifier for the OEB publication as a whole.
- METADATA - Publication metadata (title, author, publisher, etc.).
- MANIFEST - A list of files (documents, images, style sheets, etc.) that make up the publication. The manifest also includes fallback declarations for files of types not supported by this specification.
- SPINE - An arrangement of documents providing a linear reading order.
- TOURS - A set of alternate reading sequences through the publication, such as selective views for various reading purposes, reader expertise levels, etc.
- GUIDE - A set of references to fundamental structural features of the publication, such as table of contents, foreword, bibliography, etc.
Here is an informal outline of the package file:
<?xml version="1.0"?>
<!DOCTYPE package PUBLIC "+//ISBN 0-9673008-1-9//DTD OEB 1.0.1 Package//EN"
"http://openebook.org/dtds/oeb-1.0.1/oebpkg101.dtd">
<package>
<metadata>...</metadata>
<manifest>...</manifest>
<spine>...</spine>
<tours>...</tours>
<guide>...</guide>
</package>
A DTB conforming to this standard must include exactly one Package File which must be a valid XML 1.0 document conforming to the OEBF Publication Structure 1.0.1 package DTD (oebpkg101.dtd) and its associated entity reference (oeb1.ent). The full specification, DTD, and entity reference for the OEBF package file are available for download from the OEBF site [OEBF]. The Package File must be named with the extension ".opf". If a DTB spans multiple media units, the identical Package File must be present on each media unit.
A Package File conforming to this standard must comply with all aspects of section 2 of the OEBF Publication Structure 1.0.1, with the following two exceptions:
spine element may refer only to item elements of media type text/x-oeb1-document. In DTB applications, the spine must only reference items of media type application/smil.The package must include a value for its unique-identifier
attribute. This is required because more than one dc:Identifier may
be present in a DTB's Package File metadata and the unique-identifier
specifies which dc:Identifier element provides the package's primary
identifier. The value of unique-identifier must match the id attribute
of one and only one dc:Identifier element, which is a descendant of
the package element.
The primary identifier of the DTB must be globally unique.
Example 3.1:
<package unique-identifier="uid">
<metadata>
<dc-metadata...>
<dc:Identifier id="uid" scheme="DTB">uk-rnib-db02006
</dc:Identifier>
...
</package>
This portion of the Package File contains the information about a DTB that would normally be found in a library catalog record. It includes data about the DTB itself (e.g., title, author, producer, format, and narrator) as well as information about the source publication (usually a print book) such as publisher, edition, copyright statement, etc.
The Package File must contain exactly one metadata element, which must contain
one and only one dc-metadata element holding Dublin Core [DC]
metadata and must contain supplemental metadata in an x-metadata element.
The x-metadata element must contain at least one instance of the meta
element, which uses name and content attributes to define
its value. (See section 3.2.3, "X-Metadata.")
The use of Dublin Core metadata within a compliant DTB must conform to the following description from the OEBF Publication Structure 1.0.1:
The dc-metadata element contains specific publication-level metadata as defined by the Dublin Core initiative (http://purl.org/dc/). The descriptions below are included for convenience, and the Dublin Core's own definitions take precedence (see http://www.ietf.org/rfc/rfc2413.txt).
The dc-metadata element can contain any number of instances of any Dublin Core elements. Dublin Core element names begin with the "dc:" prefix followed by a leading uppercase letter. Dublin Core metadata elements may occur in any order; in fact, multiple instances of the same element type (multiple dc:Creator elements, for example) can be interspersed with other metadata elements without change of meaning.
For upwards-compatibility, the element metadata in an OEB package is required to have an attribute of xmlns:dc="http://purl.org/dc/elements/1.0/" and xmlns:oebpackage="http://openebook.org/namespaces/oeb-package/1.0/".
Following are brief definitions of the Dublin Core elements. See
the Publication Structure and the Dublin Core itself for more complete descriptions.
The attributes "xml:lang" and "id" can be applied to all "dc:..." elements.
Additional attributes can be used with several elements as detailed below. Note
that all Dublin Core element types may be repeated (occur more than once) within
dc-metadata.
package unique-identifier attribute, must include an id.Various schemes are available for identifying digital publications. In the DTB domain, the requirements for an identifier are simply to identify the publication in a manner that is highly likely to be globally unique. A major purpose of the uniqueness requirement is to prevent filename collisions among bookmark files.
To meet this base requirement, a simple DTB id scheme might be used. A DTB identifier under this scheme consists of a hyphen-separated string consisting of a two-letter country code drawn from [ISO 3166], an agency code unique within its country, and an identifier unique within the agency. For example, us-afb-x12345.
This scheme will provide a simple solution to the uniqueness requirement that will serve DTB-publishers' needs in the short term. In the longer term, as the requirements of a global library of alternative format materials become more important, other more sophisticated mechanisms will doubtless be employed.
The following names were developed for the DTB
application to supply information that the Dublin Core element set does
not cover. These names may only appear within the x-metadata containing element, as values of the name attribute on the meta
element. Each x-metadata name below is shown as either "Repeatable" (it
may be used more than once) or "Not repeatable". Content producers may
introduce other metadata within x-metadata besides those
listed below, if needed. However, metadata names shall not begin with
the prefix "dtb:" unless defined in this standard. Players must not
fail when encountering unknown metadata but must, at a minimum, ignore
it.
Example 3.2:
...
<metadata>
<dc-metadata xmlns:dc="http://purl.org/dc/elements/1.0/"
xmlns:oebpackage="http://openebook.org/namespaces/oeb-package/1.0/">
<dc:Title>Revised Standards and Guidelines of
Service for the Library of Congress Network of Libraries for the
Blind and Physically Handicapped 1995</dc:Title>
<dc:Subject>library information networks</dc:Subject>
<dc:Subject>libraries and the physically
handicapped--standards--U.S.</dc:Subject>
<dc:Subject>libraries and the
blind--standards--U.S.</dc:Subject>
<dc:Identifier id="uid"
scheme="DTB">us-nls-db00001</dc:Identifier>
<dc:Identifier
scheme="DOI">10.1000/DX44998</dc:Identifier>
<dc:Creator role="aut">American Library Association.
Association of Specialized and Cooperative Library
Agencies</dc:Creator>
<dc:Publisher>National Library Service for the Blind
and Physically Handicapped, Library of Congress</dc:Publisher>
<dc:Date>2000-06-22</dc:Date>
<dc:Source>0-8389-7797-9</dc:Source>
<dc:Language>en</dc:Language>
<dc:Format>ANSI/NISO Z39.86-2002</dc:Format>
<dc:Description>A document developed to improve library
service for blind and physically disabled persons by providing a
tool for assessing the current status of those services
and for developing long-range plans.</dc:Description>
</dc-metadata>
<x-metadata>
<meta name="dtb:sourceDate" content="1995" />
<meta name="dtb:sourcePublisher"
content="American Library Association" />
<meta name="dtb:sourceRights" content="copyright 1995,
American Library Association" />
<meta name="dtb:narrator" content="Lowenstein, Ralph" />
<meta name="dtb:producer"
content="American Foundation for the Blind" />
<meta name="dtb:multimediaType" content="audioNcx" />
<meta name="dtb:totalTime" content="06:22:34.143" />
</x-metadata>
</metadata>
...
The manifest, which is a child of the package element, must
contain a complete list of all of the files (documents, audio files, images,
style sheets, etc.) that make up a given DTB including the package file itself.
The distInfo file and any associated audio changeMsgs are not considered
part of the DTB and thus shall not be listed (See section
11, "Packaging Files for Distribution.") Each file is referenced
by an item element. Each item must have an href attribute
that is the URI of the referenced file and is unique within
the manifest. This URI must not include fragment identifiers;
if relative, it is interpreted as relative to the package file itself. Further,
any relative URIs contained within an XML file listed in the manifest are considered
to be relative to the referring file.
In addition, each item must have a media-type attribute containing
the MIME media type of the file, and an id attribute. The id
is used primarily when a manifest item is referenced by the spine.
The manifest also includes fallback declarations for files of types
not supported by this standard. (See OEBF Publication Structure
for details.) Support for the fallback mechanism is not required by this standard.
The NCX entry in the Package File manifest must have an id value equal to "ncx".
The Resource File entry in the Package File manifest must have an id value equal
to "resource". The item elements listing SMIL files in the manifest
must have a media-type attribute of "application/smil". The item
elements for the NCX, textual content file(s), Package File, and
Resource File must have media-type attribute values of "text/xml". The
order of item
elements within the manifest is not significant.
A sample
manifest for a DTB with audio, structure, and text (multimediaType=audioFullText) follows:
Example 3.3:
...
<manifest>
<item id="opf" href="rs.opf" media-type="text/xml" />
<item id="text" href="rs.xml" media-type="text/xml" />
<item id="text_style" href="dtbbase.css" media-type="text/css2" />
<item id="ncx" href="rs.ncx" media-type="text/xml" />
<item id="ncx_style" href="ncx16.css" media-type="text/css2" />
<item id="SMIL" href="rs.smil" media-type="application/smil" />
<item id="foreword" href="rs_fwdx.mp3" media-type="audio/mp3" />
<item id="standards" href="rs_stdx.mp3" media-type="audio/mp3" />
<item id="appendices" href="rs_app.mp3" media-type="audio/mp3" />
<item id="index" href="rs_index.mp3" media-type="audio/mp3" />
<item id="fig_01" href="fig1.png" media-type="image/png" />
<item id="resource" href="rs.res" media-type="text/xml" />
<item id="resource_audio" href="res.mp3" media-type="audio/mp3" />
</manifest>
...
Here is a manifest for an audio-only
version of the above DTB (multimediaType=audioNcx) where separate SMIL
files were created for each segment of the book.
Example 3.4:
...
<manifest>
<item id="opf" href="rs.opf" media-type="text/xml" />
<item id="ncx" href="rs.ncx" media-type="text/xml" />
<item id="foreword" href="rs_fwdx.mp3" media-type="audio/mp3" />
<item id="standards" href="rs_stdx.mp3" media-type="audio/mp3" />
<item id="appendices" href="rs_app.mp3" media-type="audio/mp3" />
<item id="index" href="rs_index.mp3" media-type="audio/mp3" />
<item id="SMIL1" href="rsfwd.smil" media-type="application/smil" />
<item id="SMIL3" href="rsapp.smil" media-type="application/smil" />
<item id="SMIL4" href="rsind.smil" media-type="application/smil" />
<item id="SMIL2" href="rsstd.smil" media-type="application/smil" />
</manifest>
...
The spine, a child of the package element, shall
consist of a list of one or more itemref elements whose order defines
the default linear reading order for the DTB. Each itemref must
contain an idref which points to the id of a SMIL file
listed in the manifest. Only SMIL files can be referenced by itemrefs in the spine. The itemrefs must be listed in the spine in the order in which the SMIL files are to be presented. A player must consult the
spine when it reaches the end of a SMIL file to determine which file
to render next.
The first
of the following examples shows the spine that corresponds to the first of the two
manifest examples above.
Example 3.5:
<spine>
<itemref idref="SMIL" />
</spine>
The following spine matches the second manifest example above. The correct
reading order is presented here. Note that it does not match the order of files in the
manifest where order is not significant.
Example 3.6:
<spine>
<itemref idref="SMIL1" />
<itemref idref="SMIL2" />
<itemref idref="SMIL3" />
<itemref idref="SMIL4" />
</spine>
The tours element is an optional child of the package element.
The OEBF Publication Structure describes tours
as follows: "Much as a tour guide might assemble points of interest into a set
of sightseers' tours, a content provider may assemble selected parts of a publication
into a set of tours to enable convenient navigation. ... Reading systems may
use tours to provide various access sequences to parts of the publication, such
as selective views for various reading purposes, reader expertise levels, etc."
Because of inherent differences between the structures of a DTB and the OEBF
tours, it is not feasible to implement tours in a DTB prepared
in accordance with this standard. If a producer wishes to provide the functionality
described above, it may partially achieve it by producing customized navLists
in the NCX.
Compliant players are not required to support tours.
As specified in the OEBF Publication Structure, the guide,
a child of the package element, lists the key structural features
of the DTB, such as the table of contents, introduction, bibliography, etc.
to enable playback devices to provide convenient access to them. Because DTBs
include a mandatory NCX that satisfies a more rigorous and detailed access requirement,
the guide is not expected to be used in DTBs.
Compliant players are not required to support guides.
This standard defines an XML 1.0 Document Type Definition
-- DTBook -- for markup of the textual content files of books and other publications
presented in digital talking book format. To be compliant with this standard,
a textual content file of a DTB must be a valid XML file
conforming to dtbook110.dtd, which can be found in Appendix 1, "DTBook
DTD." The version attribute on the dtbook element must
be present and contain the value drawn from the above-named DTD.
A DTB that includes textual content will, in most cases, contain only one textual content file. However, when necessary (with a very large book, for example), a DTB can contain multiple textual content files, each of which must be valid to the DTBook DTD.
DTB content producers may extend the base DTD by including one or more new elements or full modules for special situations. To remain conformant with this standard, such extensions of the DTD must employ the mechanisms specified by XML 1.0. See section 4.2.2, "Modular Extension of the DTD."
A document developed during the creation of this standard, Theory Behind the DTBook DTD [DTBook Theory], discusses the rationale underlying the DTBook element set and the benefits it provides to digital talking book applications.
Two documents external to this standard provide detailed information on the use of the element set. First, an expanded version of the DTD, in HTML format, (see [DTBook HTML]) provides full detail on each element, describing where it can be used and which elements can be used within it, along with an expanded list of attributes.
Second, a comprehensive set of guidelines for applying DTBook markup is available from the DAISY Consortium. These Structure Guidelines [StructGuide] describe the correct application of the DTBook element set, emphasize the importance of capturing the structure of the text content, and provide detailed examples of the use of all DTBook elements.
The DTBook element set has considerable application outside of the digital talking book as well. It was designed to enable the production of documents in a variety of accessible formats. At least one U.S. Braille translation software package has implemented a facility that imports DTBook documents and automatically translates and formats them in Grade 2 Braille. It is expected that similar automated processes will be developed for converting properly marked-up documents into large print and for rendering DTBook documents in Braille, synthetic speech, and large print "on the fly." Finally, an attribute called "showin" is incorporated in the DTBook element set to control the display of selected segments of a DTBook document. For example, descriptions of a graph might vary between Braille and large print editions; "showin" could allow only the appropriate version to show in each edition, although both would be present in the DTBook document.
This standard does not mandate the degree of markup to be applied to a textual content file. However, the richer the markup, the greater the functionality available to the reader.
For more information on XML 1.0 markup and DTD usage, see the W3C XML site [XML].
To ensure efficient player operation with DTBs containing textual content files, the smilref attribute must be present and non-empty for each element in the textual content file referenced by a SMIL file. The smilref value shall normally be the URI of the SMIL time container (par or seq)
containing the media object that references a given element. However,
in a text-only DTB consisting of a sequence of text media objects, smilref contains the URI of the media object that references the element. The smilref attribute permits the DTB player to resume SMIL-based playback following text-based navigation, full-text searches, etc.
The DTBook DTD includes a base set of elements for use in marking up a broad range of material. Additional modules containing elements for specialized applications such as poetry, plays, dictionaries, mathematics, etc. can be "invoked" from within a DTBook document when needed, as described below.
A DTBook document is an XML application. Therefore it should
begin with the XML declaration identifying the version of XML, and the optional
character set encoding. (See Appendix 1, "DTBook DTD"
for more information.)
<?xml version="1.0" encoding="UTF-8" ?>
This is followed by the document type declaration:
<!DOCTYPE dtbook SYSTEM "dtbook110.dtd" >
For discussion of other ways of expressing the DOCTYPE, see section 2.3 of Appendix 1, "DTBook DTD."
A book can invoke other DTDs or modules to augment the DTBook DTD by adding instructions in square brackets before the concluding ">" of the document type declaration. Such instructions in square brackets are called the "internal subset of declarations." For example:
<!DOCTYPE dtbook SYSTEM "dtbook110.dtd"
[
<!ENTITY % dramaModule SYSTEM "drama.dtd" >
%dramaModule;
<!ENTITY % externalblock "| drama">
<!ENTITY % externalinline "| stagedir">
]>
The first line of the internal subset declares an
entity known as "dramaModule" and provides the URI where that module
can be found. The second line invokes this entity, that is "brings it
into" the current document, just as the DOCTYPE declaration invoked the
base DTD (dtbook110.dtd). The third line declares the entity "%
externalblock" and gives it the value "drama". Since dtbook110.dtd
contains an entity of the same name, and the internal subset overrules
the base (external) DTD (dtbook110.dtd) in areas of conflict,
everywhere in dtbook110.dtd where "%externalblock;" appears (that is,
wherever block elements are allowed), the value "drama" is added. Since
drama is the root element in the drama module, the full
drama module can be used there. Similarly, the last line effectively
allows the element stagedir to be used anywhere "%externalinline;" is allowed in dtbook110.dtd (that is, wherever inline elements can be used).
More than one module may be needed and included in a
book. In the following example, both a poetry and drama module are
invoked, as well as one inline element (stagedir) from the drama module.
[
<!ENTITY % poemModule "http://www.xyz.org/poem.dtd" >
%poemModule;
<!ENTITY % dramaModule "http://www.xyz.org/drama.dtd" >
%dramaModule;
<!ENTITY % externalblock "| poem | drama" >
<!ENTITY % externalinline "| stagedir">
]>
See section 3 of Appendix 1, "DTBook DTD" for a more detailed discussion of this issue.
A set of audio file formats is listed below. A compliant audio player must be capable of decoding at least one of the formats listed. It is strongly recommended that players be able to decode all listed formats. Content compliant with this standard must be delivered in one of the formats below, or any mixture of them. The file extensions shown for each format must be used in audio filenames in compliant DTBs. Values are not case-sensitive.
It is permissible for parts of a single book to be encoded in different audio formats. For example, a producer may choose to encode a lengthy bibliography at a lower bit rate or with a different codec than the main body of the book. Players must support transitions between differently encoded sections smoothly. There is no restriction on the granularity of these parts, i.e. they may occur at any point in the SMIL presentation.
Support for multi-channel rendering is not required. Stereo signals must be recognized and rendered at least in monaural format.
A compliant DTB player that provides audio output should be capable of decoding the following audio formats:
While the ISO standards for MP3 and AAC require support for variable bit rate playback, players compliant with this standard are only required to support constant bit rate playback.
Players must support sample rates of 44.1, 22.05, and 11.025 kHz at a depth of 16 bits per sample. Compressed audio must be encoded such that the output sampling rate is restricted to one of the above three rates.
Audio players capable of recording and exporting audio notes for bookmarks and highlights must support encoding in the following format or one of the formats specified in section 5.1. Audio players capable of importing bookmarks and highlights must support decoding of the following format.
Images included in DTBs must be presented in one or more of the following formats: JPEG (JFIF V 1.02) [JPEG] (extension: .jpg), PNG [RFC 2083] (extension: .png), or Scalable Vector Graphics [SVG] (extension: .svg). Filenames must use the file extensions specified; values are not case-sensitive. Compliant playback devices that support image display must be capable of displaying JPEG and PNG; support for SVG is recommended. Appendix 8 of the SVG specification addresses accessibility issues.
The Synchronized Multimedia Integration Language (SMIL 2.0) [SMIL] was developed by the World Wide Web Consortium as a standard for definition and playback of multimedia presentations over the Internet. SMIL defines the sequence of playback for one or more media objects. In the case of DTBs, the primary media objects are audio and textual content files; SMIL provides for their parallel and synchronized presentation. Any DTB constructed using SMIL, and utilizing content encoded in standard text and audio media types, is playable on any device or platform which has implemented a SMIL-conformant player of the same or later SMIL version, so long as the necessary audio and textual rendering decoders are present and no system for intellectual property protection restricts access.
What distinguishes a DTB playback system from a basic SMIL player is the inclusion of specific navigation and presentational capabilities set out in the user requirements for DTBs ([Navigation Features]). These capabilities can use information from an NCX file, from the textual content, and/or from the SMIL file itself. The key to this information is the inclusion of unique identifiers within the textual content (when present) and SMIL files. Audio files are indexed by time-based positions and in themselves contain no embedded semantic structure. To provide semantic structure to audio content, it is necessary to associate time-points in the audio file with the corresponding position within the textual content. This is achieved using SMIL through the pairing of a pointer to a specific position within a textual content file (referenced by a URI) with its corresponding time position in the audio content. In the case of the DTB SMIL application, each synchronization point within the SMIL file is assigned a unique identifier. The presence of these identifiers within both the textual content and the SMIL allows navigation to occur by several different methods, as determined by the playback system.
SMIL incorporates a control structure called customTests,
which allows SMIL authors to identify by class selected elements of a
document (e.g., notes, page numbers, line numbers). The playback device
can then expose to the user the presence of these classes and allow the
user to select whether a given class of elements is to be read or
skipped over during sequential playback.
The DTB producer determines granularity of the synchronization events. Synchronization events can be limited to the primary structural elements (those indicated in the NCX) or can be augmented in books with full textual content to include synchronization down to paragraph, sentence, or even word level. The requirement for this level of synchronization is that the textual content includes mark-up tags for the desired elements and that those elements include unique identifiers that can be referenced in the SMIL files.
The SMIL file for a DTB typically will consist of a sequence of parallel events
(e.g., text and audio (and possibly image) events occurring simultaneously).
SMIL represents this structure through the use of the "time containers" seq
(sequence of media objects) and par (parallel time grouping in which
multiple media objects play back at the same time). A simple form of DTB SMIL
file would be as follows, where the three pars shown are played one
after the other, and the text and audio content referenced in each par are rendered simultaneously:
<smil> ... <seq> <par><text.../><audio.../></par> <par><text.../><audio.../></par> <par><text.../><audio.../><img.../></par> </seq> ... </smil>
Synchronization of media objects in this standard is based on the SMIL 2.0 specification. Developers are requested to reference SMIL 2.0 [SMIL] for complete background and details. Only a small subset of the SMIL specification is used in this implementation, drawing from the following modules, which are grouped by functional area. Modules marked with asterisks are used in whole or in part in this application; the others are not used but are included because they are part of a core set of modules required for host language conformance under W3C modularization guidelines.
The modules mentioned above can be combined, using W3C modularization guidelines, to form a profile specific to DTB applications. Section 2 of the SMIL specification, "The SMIL 2.0 Modules," describes this process in detail.
To simplify validation using commonly available parsers and to lessen the complexity of determining content models and applicable attribute lists, a DTB-Specific SMIL DTD is included in this standard in Appendix 2. This DTD includes only those elements and attributes from the modules listed above that are required for the DTB application. In addition, it is more restrictive than the SMIL modules in that id attributes are often required in the DTB application when they are implied in the SMIL modules.
A compliant DTB must contain at least one SMIL file. All SMIL files included in a DTB must be valid XML documents conforming to dtbsmil110.dtd.
Time containers (seqs or pars) within SMIL files must contain
ids. Media objects (audio, text, and img) may also
contain ids, although this practice will generally be limited to single-medium
DTBs. See section 7.4.10, "Text-Only DTBs."
In the textual content file, each segment to be synchronized (e.g., heading,
paragraph, list item, etc.) must be contained within an element carrying a unique
id to which the corresponding SMIL segment points. In addition, any textual
content file element referenced by a SMIL file must include a smilref attribute
specifying the URI of the time container or media object that references it.
The smilref value shall normally be the URI of the SMIL time container
containing the media object that references a given element. However, in a text-only
DTB consisting of a sequence of text media objects, smilref shall contain
the URI of the referencing media object itself. See section 4.2.1, "DTBook
Markup Related to SMIL."
It is strongly recommended that the SMIL file(s) have a level of granularity matching that of the textual content file. That is, if the textual content file is marked up to the paragraph level, the SMIL file(s) should include synchronization to the paragraph level.
All time offsets in SMIL files (and all other applicable DTB files, e.g., NCX clipBegin/clipEnd, bookmark timeOffsets,
etc.), are based on normal play speed. In order to maintain
synchronization, a player must process time offsets independently of
actual playback speed.
As mentioned above, the DTB application uses only a portion of the elements and attributes that make up the modules in the DTB SMIL Profile. Playback devices compliant with this standard need support only the following SMIL elements and attributes, which make up the DTB-Specific SMIL DTD.
smil. The smil element contains exactly one head and exactly one body.<!ELEMENT smil (head, body) ><smil>...content...</smil> meta element), optional layout,
and optional customAttributes, in that order. <!ELEMENT head ((meta)*, (layout)?, (customAttributes)?
) ><head>...content...</head><smil> <meta ...attributes... /><!ELEMENT meta EMPTY ><head> region elements it
contains) where on a visual, audio, or tactile rendering space various producer-defined
elements, e.g., figures, text, footnotes, etc. are displayed.<!ELEMENT layout (region)+ ><layout>...content...</layout><head><!ELEMENT region EMPTY ><region ...attributes... />region attribute on media
object references the id on appropriate region element.region in display
space. See SMIL 2.0 for details.region display space.
See SMIL 2.0 for details.region in display
space. See SMIL 2.0 for details.region in display space.
See SMIL 2.0 for details.region in display
space. See SMIL 2.0 for details. region in display
space. See SMIL 2.0 for details.region in which it is displayed. See SMIL
2.0 for definitions of attribute values.region that is not covered by the media object(s) being displayed.backgroundColor of a region is shown when
no media is being rendered to the region. See SMIL
2.0 for definitions of attribute values.<layout>region attribute references
the id on a given region element will be displayed in that region.
customTests that allow
the producer to specify kinds of structures that the user can choose to have
automatically rendered or skipped.<!ELEMENT customAttributes (customTest)+ ><customAttributes>...content...</customAttributes><head>customTest attribute
for par and seq below.<!ELEMENT customTest EMPTY ><customTest ...attributes... />customTest attribute on par or seq in
body of SMIL. value = true) or skip (value = false)
the structure during sequential playback. If no value is present, the
default is false and the content is skipped.value= "visible") or hide from (value
= "hidden") the reader the ability to override the setting of defaultState.
See section 7.4.3, "'Skippable' Structures" for normative
content.<customAttributes><!ELEMENT body (par|seq|text|audio|img|a)+ ><body>...content...</body><smil>body contains zero or more seqs
or pars and may also directly contain zero or more media objects
(text, audio, img), or links (a). pars and seqs.<!ELEMENT seq (par|seq|text|audio|img|a)+ ><seq>...content...</seq>seq
with matching customTest element in head. begin. body, seq, parseqs. <!ELEMENT par (seq|text|audio|img|a)+ ><par>...content...</par>customTest
element in head. body, seqpars" for
normative content. <!ELEMENT text EMPTY ><text...attributes.../>region (defined
in layout in document head) in which the text
will be presented. References the id of the appropriate region.
All types of text objects that are to appear in the same rendering space
would be assigned the same value for region. For example,
page numbers and producer's notes might both be displayed in the main
text area of a screen (region="text"), while notes (e.g.,
footnotes) might be displayed in a separate area at the bottom of the
screen (region="notes").body, par, seq<!ELEMENT audio EMPTY ><audio...attributes... />clipBegin. region (defined
in layout in document head) in which the audio object
will be presented. References the id of the appropriate region.body, par, seq<!ELEMENT img EMPTY ><image...attributes... />region (defined
in layout in document head) in which the image will
be presented. References the id of the appropriate region.body, par, seq