ISO/IEC 21000-20:2016
(Main)Information technology — Multimedia framework (MPEG-21) — Part 20: Contract Expression Language
Information technology — Multimedia framework (MPEG-21) — Part 20: Contract Expression Language
ISO/IEC 21000-20:2016 specifies a language for representing contracts in the Multimedia Framework formed for the transaction of MPEG-21 Digital Items or services related to the MPEG-21 Framework. Contract Expression Language (CEL) aims at digitally representing the agreements made in environments using ISO/IEC 21000. These agreements are contracts for transactions of content packed as Digital Items, as well as services provided around this content. The range of contracts under scope are as follows: - contracts about transactions on rights for the exploitation of content as MPEG-21 Digital Items; - contracts about the provision of MPEG-21-based services, i.e. delivery, identification, encryption, search and others. The aspects represented by CEL contracts include the following: - the textual clauses, in natural language as they are in the narrative contract, duly structured; - the operative clauses, as computer language expressions.
Technologies de l'information — Cadre multimédia (MPEG-21) — Partie 20: Langage d'expression des contrats
General Information
Relations
Buy Standard
Standards Content (Sample)
INTERNATIONAL ISO/IEC
STANDARD 21000-20
Second edition
2016-12-15
Information technology — Multimedia
framework (MPEG-21) —
Part 20:
Contract Expression Language
Technologies de l’information — Cadre multimédia (MPEG-21) —
Partie 20: Langage d’expression des contrats
Reference number
ISO/IEC 21000-20:2016(E)
©
ISO/IEC 2016
---------------------- Page: 1 ----------------------
ISO/IEC 21000-20:2016(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO/IEC 2016, Published in Switzerland
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
Ch. de Blandonnet 8 • CP 401
CH-1214 Vernier, Geneva, Switzerland
Tel. +41 22 749 01 11
Fax +41 22 749 09 47
copyright@iso.org
www.iso.org
ii © ISO/IEC 2016 – All rights reserved
---------------------- Page: 2 ----------------------
ISO/IEC 21000-20:2016(E)
Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms, definitions and abbreviated terms . 1
3.1 Terms and definitions . 1
3.2 Abbreviated terms . 2
4 Conventions . 3
4.1 Document conventions . 3
4.2 Namespace prefix conventions . 4
4.2.1 General. 4
4.2.2 Use of prefixes . 4
5 Relationship to other parts of ISO/IEC 21000 . 5
6 Overview . 5
6.1 General aspects . 5
6.2 Syntactic representation . 6
7 Contract Structured Representation . 6
7.1 General . 6
7.2 XML Schema definition . 6
7.2.1 Contract element and main structure . 6
7.2.2 Example . 8
7.2.3 Metadata . 8
7.2.4 Element to relate contracts . 9
7.2.5 The parties . 9
7.2.6 Body element .12
7.3 CEL Deontic Structure.18
7.3.1 General.18
7.3.2 Deontic Structured Block .18
7.3.3 Statement .19
7.3.4 Deontic Structured Clause Type .19
7.4 CEL Extension for Exploitation of Intellectual Property Rights .35
7.4.1 General.35
7.4.2 Acts .36
7.4.3 Constraints .39
7.4.4 Permission attributes .55
7.5 CEL Extension for payments and notifications .55
7.5.1 General.55
7.5.2 Payment .56
7.5.3 Notify .58
7.6 CEL Extension for Rights Expression Language standard and multimedia
extensions rights and conditions .59
7.6.1 General.59
7.6.2 Acts .59
7.6.3 Constraints .61
7.7 Examples .63
7.7.1 General.63
7.7.2 Simple permission .63
7.7.3 Simple prohibition . .63
7.7.4 Simple obligation .64
7.7.5 Statement .65
7.7.6 PreCondition example .66
7.7.7 Complex permission .67
© ISO/IEC 2016 – All rights reserved iii
---------------------- Page: 3 ----------------------
ISO/IEC 21000-20:2016(E)
7.8 CEL Extension mechanism .68
Annex A (normative) Schemas .70
Annex B (informative) Examples of CEL contracts .71
Bibliography .81
iv © ISO/IEC 2016 – All rights reserved
---------------------- Page: 4 ----------------------
ISO/IEC 21000-20:2016(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 World Trade Organization (WTO) principles in the
Technical Barriers to Trade (TBT) see the following URL: www.iso.org/iso/foreword.html.
The committee responsible for this document is ISO/IEC JTC 1, Information Technology, Subcommittee
SC 21, Coding of audio, picture, multimedia and hypermedia information.
This second edition cancels and replaces the first edition (ISO/IEC 21000-20:2013), which has been
technically revised with the following changes:
— some strengthening of the core contract part and some reordering within the extension for the
exploitation of intellectual property rights have been provided;
— the set of facts available for specifying conditions has been completed;
— addition of a simple payment and notification extension;
— the relationship with acts defined in ISO/IEC 21000-5 (REL) has been refined;
— a clear mechanism for defining further future extensions is in place.
A list of parts in the ISO/IEC 21000 series can be found on the ISO website.
© ISO/IEC 2016 – All rights reserved v
---------------------- Page: 5 ----------------------
ISO/IEC 21000-20:2016(E)
Introduction
Today, many elements exist to build an infrastructure for the delivery and consumption of multimedia
content. There was, however, no ʺbig pictureʺ to describe how these elements, either in existence or
under development, relate to each other. The aim for the ISO/IEC 21000 series has been to describe
how these various elements fit together. New standards, as appropriate, will be developed while other
relevant standards may be developed by other bodies.
The result is an open framework for multimedia delivery and consumption, with both the content
creator and content consumer as focal points. This open framework provides content creators and
service providers with equal opportunities in the ISO/IEC 21000 series-enabled open market. This will
also be to the benefit of the content consumer providing them access to a large variety of content in
an interoperable manner. The vision for ISO/IEC 21000 is to define a multimedia framework to enable
transparent and augmented use of multimedia resources across a wide range of networks and devices
used by different communities.
ISO/IEC 21000 series aims thus at defining an open framework for multimedia applications, where
users distribute, consume, operate on and transact with content represented as Digital Items.
These transactions can be automatically governed by licenses using the Rights Expression Language
from ISO/IEC 21000. However, beyond the operative information present in a digital license, the digital
representation of the complete business agreements between the parties may prove useful for a number
of purposes. The Contract Expression Language (CEL) is the ISO/IEC language to express such contracts
in a structured representation.
CEL may be used to represent contracts, for content directly, or for services on content based on MPEG-
21 technologies. However, CEL may also be used as electronic format for contracts on the trade of media
rights also beyond the MPEG framework.
The provided features include the identification of the contract itself and of its parties, and an
unambiguous expression of the agreed permissions, obligations, and prohibitions, in a machine readable
way, so that their verification can be implemented in software.
In particular, the CEL deontic expressions address the rights for the exploitation of intellectual property
entities, including the specification of the associated conditions, together with other contractual
aspects, such as payments, notifications or material delivery.
However, CEL may also be used as electronic format for contracts on the trade of media rights also
beyond the MPEG framework.
The main aspect of CEL contracts are the operative clauses, represented as machine readable deontic
expressions, i.e. the agreed permissions, obligations, and prohibitions, and the associated terms and
conditions.
Besides, the CEL contract includes the identification of the contract itself, its parties, and the possible
relationships with other contracts.
Among the provided features, there is the possibility to insert the textual version of the contract and/or
of specific clauses, in particular for the case in which the original contract is narrative, i.e. written
in natural language. Also, it is possible to add metadata related to any contract entity and to have
encryption of the whole contract, or any sub-part of it. As electronic format for a contract document,
the agreement of the parties can be proved by their digital signature.
Eventually, CEL provides to the media companies the basic means for the collection of knowledge on held
rights, also derived from multiple contracts, as rights port-folio, for business management purposes.
Various potential benefits can be associated to the use of CEL. Firstly, CEL can support the business of
media companies, for product placement and maximizing reuse of archive content, implying also cost
reductions in all rights related activities, e.g. rights clearance. Afterwards, it supports the respect of
copyright laws with respect to new exploitation technologies, also by contributing to the reduction of
vi © ISO/IEC 2016 – All rights reserved
---------------------- Page: 6 ----------------------
ISO/IEC 21000-20:2016(E)
mistakes with respect to contract compliance, implying decreasing number of controversies and other
cost reductions. In general, CEL aims at increasing the quality of rights information, which gets more
reliable and can be integrated with other metadata in standard way. This can bring even to improve
working conditions and all the decision processes within media companies.
© ISO/IEC 2016 – All rights reserved vii
---------------------- Page: 7 ----------------------
INTERNATIONAL STANDARD ISO/IEC 21000-20:2016(E)
Information technology — Multimedia framework
(MPEG-21) —
Part 20:
Contract Expression Language
1 Scope
This document specifies a language for representing contracts in the Multimedia Framework formed
for the transaction of MPEG-21 Digital Items or services related to the MPEG-21 Framework.
Contract Expression Language (CEL) aims at digitally representing the agreements made in
environments using ISO/IEC 21000. These agreements are contracts for transactions of content packed
as Digital Items, as well as services provided around this content.
The range of contracts under scope are as follows:
— contracts about transactions on rights for the exploitation of content as MPEG-21 Digital Items;
— contracts about the provision of MPEG-21-based services, i.e. delivery, identification, encryption,
search and others.
The aspects represented by CEL contracts include the following:
— the textual clauses, in natural language as they are in the narrative contract, duly structured;
— the operative clauses, as computer language expressions.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO/IEC 21000-5, Information technology — Multimedia framework (MPEG-21) — Part 5: Rights
Expression Language
3 Terms, definitions and abbreviated terms
3.1 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at http://www.electropedia.org/
— ISO Online browsing platform: available at http://www.iso.org/obp
3.1.1
action
something done or performed by a party (3.1.6) or anyone acting on her behalf
Note 1 to entry: Action also represents the exercise of a right or duty.
© ISO/IEC 2016 – All rights reserved 1
---------------------- Page: 8 ----------------------
ISO/IEC 21000-20:2016(E)
3.1.2
deontic expression
generic entity encompassing the properties of an agreed machine readable contract clause regulating
the actions (3.1.1) of the parties (3.1.6)
3.1.3
MPEG-21 Contract
representation of agreements formed for the transaction of MPEG-21 Digital Items or services related
to the MPEG-21 Framework
3.1.4
MPEG-21 Service
system supplying utility in the MPEG-21 Framework
3.1.5
obligation
deontic expression (3.1.2) binding one of the parties (3.1.6) to execute an action (3.1.1)
3.1.6
party
organization or a user who accepts to respect the deontic expressions (3.1.2) defined in the contract and
who expects the other parties (3.1.6) in the same contract to do the same
3.1.7
permission
deontic expression (3.1.2) allowing one of the parties (3.1.6) to execute an action (3.1.1)
3.1.8
prohibition
deontic expression (3.1.2) binding one of the parties (3.1.6) not to execute an action (3.1.1)
3.2 Abbreviated terms
CEL Contract Expression Language
IPRE Intellectual Property Rights Exploitation
IRI Internationalized Resource Identifier
MCO Media Contract Ontology
MPEG Moving Picture Experts Group
MPEG-7 ISO/IEC 15938
MPEG-21 ISO/IEC 21000
OWL Web Ontology Language
RDF Resource Description Framework
REL Rights Expression Language
URI Uniform Resource Identifier (IETF Standard is RFC 3986)
URN Uniform Resource Name (IETF Standard is RFC 2141)
W3C World Wide Web Consortium
XML Extensible Markup Language (W3C Recommendation)
2 © ISO/IEC 2016 – All rights reserved
---------------------- Page: 9 ----------------------
ISO/IEC 21000-20:2016(E)
4 Conventions
4.1 Document conventions
XML Representation
The syntax of each XML element in the Contract Expression Language is specified using the constructs
provided by XML Schema. XML Schema documents or its fragments are presented in orange boxes.
Omissions are marked with suspension points ([.]).
XML documents or its fragments are presented in gray boxes. Omissions are marked with suspension
points ([…]).
cel-core.xsdʺ xmlns:dc=ʺhttp://purl.org/dc/elements/1.1/ʺ [.]
This document also makes use of diagrams to express portions of XML Schema, as shown in Figure 1.
Figure 1 — Sample XML Schema diagram
Figure 1 states which elements are required (boxes with solid outline), those that are optional (boxes
with dashed outline), the number of occurrences of each element (0…), and the lineage between elements
(symbols between elements indicating either a choice, or a sequence).
Figure 2 — Compositors used in XML Schema diagrams
Compositors, as shown in Figure 2, describe (from left to right), respectively, a sequence of elements, a
choice of elements and the all model.
© ISO/IEC 2016 – All rights reserved 3
---------------------- Page: 10 ----------------------
ISO/IEC 21000-20:2016(E)
Figure 3 — Graphical representation of contract examples
Graphical description of contract examples, as shown in Figure 3, presents how the elements in a
contract relate between themselves to facilitate understanding of complex representations. FactUnion
and FactIntersection allow the combination of constraints to represent complex relationships between
the constraints defined in this document to represent a contract.
4.2 Namespace prefix conventions
4.2.1 General
The namespace for CEL core XML Schema is:
urn:mpeg:mpeg21:cel:core:2015
The namespace for CEL extension on exploitation of intellectual property rights XML Schema is:
urn:mpeg:mpeg21:cel:ipre:2015
The namespace for CEL extension on payments and notification XML Schema is:
urn:mpeg:mpeg21:cel:pane:2015
The namespace for CEL extension on MPEG-21 REL standard and multimedia extensions is:
urn:mpeg:mpeg21:cel:rele:2015
4.2.2 Use of prefixes
The CEL makes use of elements defined in other schemas, either given by MPEG-21 or others. The used
namespace prefixes together with their reference is given in Table 1.
4 © ISO/IEC 2016 – All rights reserved
---------------------- Page: 11 ----------------------
ISO/IEC 21000-20:2016(E)
Table 1 — Mapping of prefixes to namespaces in examples and text
Prefix Corresponding namespace Ref
cel-core urn:mpeg:mpeg21:cel:core:2015 Here
cel-ipre urn:mpeg:mpeg21:cel:ipre:2015 Here
cel-pane urn:mpeg:mpeg21:cel:pane:2015 Here
cel-rele urn:mpeg:mpeg21:cel:rele:2015 Here
dc http://purl.org/dc/elements/1.1/ ISO 15836
dii urn:mpeg:mpeg21:2002:01-DII-NS ISO/IEC 21000-3
W3C XML Signature Syntax
dsig
http://www.w3.org/2000/09/xmldsig#
and Processing
rel-mx urn:mpeg:mpeg21:2003:01-REL-MX-NS ISO/IEC 21000-5
rel-r urn:mpeg:mpeg21:2003:01-REL-R-NS ISO/IEC 21000-5
rel-sx urn:mpeg:mpeg21:2003:01-REL-SX-NS ISO/IEC 21000-5
W3C XML Encryption Syntax
xenc
http://www.w3.org/2001/04/xmlenc#
and Processing
xsd W3C XML Schema
http://www.w3.org/2001/XMLSchema
xsi W3C XML Schema Instance
http://www.w3.org/2001/XMLSchema-instance
5 Relationship to other parts of ISO/IEC 21000
The Digital Item is the fundamental unit of distribution and transaction in the Multimedia Framework.
While the different parts of ISO/IEC 21000 deal with the components and different aspects of Digital
Items, together they form a complete integrated interoperable framework. This clause describes the
relationship of this document with the other parts of ISO/IEC 21000 in addressing the representation of
the agreements for the aforementioned transactions.
A contract represented following this document may become a part of a digital item (whose declaration
is given with the ISO/IEC 21000-2). If so, it will be declared with the Type element of ISO/IEC 21000-3
pointing to the CEL URI, as described in B.3.
This document has the aim, as ISO/IEC 21000-21, of digitally representing contracts information.
CEL enables the structured representation of contracts’ information making use of XML, while MCO
provides their semantic representation by means of OWL or RDF. Both parts share the goal of defining
a contract document able to provide the information listed in 6.1 and they share the semantics for
actions, facts and services.
This document also supports the expression of rights and conditions as defined in ISO/IEC 21000-5.
6 Overview
6.1 General aspects
A Contract Expression Language (CEL) contract is a document providing the following information,
optional unless otherwise stated:
— identification of the contract itself — Required;
— possible relationships with other contracts;
— the Parties — Required;
— the textual version of the contract;
— a number of textual clauses which can be referenced by the operative part element;
© ISO/IEC 2016 – All rights reserved 5
---------------------- Page: 12 ----------------------
ISO/IEC 21000-20:2016(E)
— the Object of the contract (Content or Service) — Required;
— the Operative part, containing the contract information which have to be machine readable (deontic
expressions, links to textual clauses) — Required.
CEL supports the possibility to encrypt either the whole contract or part of it.
CEL aims at providing the structural elements to syntactically represent operative clauses, in a
machine-readable form.
6.2 Syntactic representation
A Contract document defined by CEL shall be compliant to the XML representation defined in Clause 7.
The document format is specified by an XML Schema. Any representation of a contract document
defined by CEL supports the possibility of encrypting either the whole contract or part of it.
Contract documents shall validate against the CEL XML Schema, which is provided in Annex A. A
detailed description of the structured representation is given in Clause 7.
7 Contract Structured Representation
7.1 General
CEL standard specification enables the structured representation of digital media contracts by means
of XML. To this end, the CEL core XML schema has been defined. It normatively defines the core elements
for media contracts. Its URI is:
urn:mpeg:mpeg21:cel:core:2015
Media contracts consist of
...
DRAFT INTERNATIONAL STANDARD
ISO/IEC DIS 21000-20
ISO/IEC JTC 1/SC 29 Secretariat: JISC
Voting begins on: Voting terminates on:
2015-09-21 2015-12-21
Information technology — Multimedia framework (MPEG-
21) —
Part 20:
Contract Expression Language
Technologies de l’information — Cadre multimédia (MPEG-21) —
Partie 20: Langage d’expression des contrats
ICS: 35.040
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENT AND APPROVAL. IT IS
THEREFORE SUBJECT TO CHANGE AND MAY
NOT BE REFERRED TO AS AN INTERNATIONAL
STANDARD UNTIL PUBLISHED AS SUCH.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
BE CONSIDERED IN THE LIGHT OF THEIR
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
Reference number
NATIONAL REGULATIONS.
ISO/IEC DIS 21000-20:2015(E)
RECIPIENTS OF THIS DRAFT ARE INVITED
TO SUBMIT, WITH THEIR COMMENTS,
NOTIFICATION OF ANY RELEVANT PATENT
RIGHTS OF WHICH THEY ARE AWARE AND TO
©
PROVIDE SUPPORTING DOCUMENTATION. ISO/IEC 2015
---------------------- Page: 1 ----------------------
ISO/IEC DIS 21000-20:2015(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO/IEC 2015, Published in Switzerland
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
Ch. de Blandonnet 8 • CP 401
CH-1214 Vernier, Geneva, Switzerland
Tel. +41 22 749 01 11
Fax +41 22 749 09 47
copyright@iso.org
www.iso.org
ii © ISO/IEC 2015 – All rights reserved
---------------------- Page: 2 ----------------------
ISO/IEC DIS 21000-20
Contents Page
Foreword . iv
Introduction . vi
1 Scope . 1
2 Normative references . 2
3 Terms, definitions and abbreviated terms . 3
3.1 Terminology . 3
3.2 Abbreviated terms . 3
4 Conventions . 4
4.1 Document conventions . 4
4.2 Namespace prefix conventions . 6
5 Relationship to other ISO/IEC 21000 Parts . 7
6 Overview . 8
6.1 General aspects . 8
6.2 Syntactic representation. 8
7 Contract Structured Representation . 8
7.1 Introduction . 8
7.2 XML Schema definition . 9
7.3 CEL Deontic Structure . 20
7.4 CEL Extension for Exploitation of Intellectual Property Rights . 36
7.5 CEL Extension for Payments and Notifications . 55
7.6 CEL Extension for Rights Expression Language standard and multimedia extensions
rights and conditions . 59
7.7 Examples . 62
7.8 CEL Extension mechanism (informative) . 65
Annex A (normative) Schemas . 66
A.1 CEL XML Schemas . 66
A.2 CEL Reference Data . 66
Annex B (informative) Examples of CEL Contracts . 67
B.1 Example 1 . 67
B.2 Example 2 . 72
B.3 CEL contract as part of Digital Item . 75
© ISO/IEC 2015 – All rights reserved iii
---------------------- Page: 3 ----------------------
ISO/IEC DIS 21000-20
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.
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 21000-20 was prepared by Joint Technical Committee ISO/IEC JTC 1, Information Technology,
Subcommittee SC 21, Coding of audio, picture, multimedia and hypermedia information.
This second edition cancels and replaces the first edition which has been technically revised.
ISO/IEC 21000 consists of the following parts, under the general title Information Technology — Multimedia
Framework (MPEG-21):
⎯ Part 1: Vision, Technologies and Strategy [Technical Report]
⎯ Part 2: Digital Item Declaration
⎯ Part 3: Digital Item Identification
⎯ Part 4: Intellectual Property Management and Protection Components
⎯ Part 5: Rights Expression Language
⎯ Part 6: Rights Data Dictionary
⎯ Part 7: Digital Item Adaptation
⎯ Part 8: Reference Software
⎯ Part 9: File Format
⎯ Part 10: Digital Item Processing
⎯ Part 11: Evaluation Tools for Persistent Association Technologies [Technical Report]
⎯ Part 12: Test Bed for MPEG-21 Resource Delivery [Technical Report]
⎯ Part 14: Conformance Testing
⎯ Part 15: Event Reporting
iv © ISO/IEC 2015 – All rights reserved
---------------------- Page: 4 ----------------------
ISO/IEC DIS 21000-20
⎯ Part 16: Binary Format
⎯ Part 17: Fragment Identification of MPEG Resources
⎯ Part 18: Digital Item Streaming
⎯ Part 19: Media Value Chain Ontology
⎯ Part 20: Contract Expression Language
⎯ Part 21: Media Contract Ontology
© ISO/IEC 2015 – All rights reserved v
---------------------- Page: 5 ----------------------
ISO/IEC DIS 21000-20
Introduction
Today, many elements exist to build an infrastructure for the delivery and consumption of multimedia content.
There was, however, no "big picture" to describe how these elements, either in existence or under
development, relate to each other. The aim for the set of standards ISO/IEC 21000 has been to describe how
these various elements fit together. New standards as appropriate will be developed while other relevant
standards may be developed by other bodies.
The result is an open framework for multimedia delivery and consumption, with both the content creator and
content consumer as focal points. This open framework provides content creators and service providers with
equal opportunities in the ISO/IEC 21000 enabled open market. This will also be to the benefit of the content
consumer providing them access to a large variety of content in an interoperable manner. The vision for
ISO/IEC 21000 is to define a multimedia framework to enable transparent and augmented use of multimedia
resources across a wide range of networks and devices used by different communities.
ISO/IEC 21000 aims thus at defining an open framework for multimedia applications, where users distribute,
consume, operate on and transact with content represented as Digital Items.
These transactions can be automatically governed by licenses using the Rights Expression Language from
ISO/IEC 21000. However, beyond the operative information present in a digital license, the digital
representation of the complete business agreements between the parties may prove useful for a number of
purposes. The Contract Expression Language (CEL) is the ISO/IEC language to express such contracts in a
structured representation.
CEL may be used to represent contracts, for content directly, or for services on content based on MPEG-21
technologies. However CEL may also be used as electronic format for contracts on the trade of media rights
also beyond the MPEG framework.
The provided features include the identification of the contract itself and of its parties, and an unambiguous
expression of the agreed permissions, obligations, and prohibitions, in a machine readable way, so that their
verification can be implemented in software.
In particular the CEL deontic expressions address the rights for the exploitation of intellectual property entities,
including the specification of the associated conditions, together with other contractual aspects, such as
payments, notifications or material delivery.
vi © ISO/IEC 2015 – All rights reserved
---------------------- Page: 6 ----------------------
FINAL COMMITTEE DRAFT ISO/IEC DIS 21000-20
Information Technology — Multimedia Framework (MPEG-21) —
Part 20: Contract Expression Language
1 Scope
This part of ISO/IEC 21000 specifies a language for representing contracts in the Multimedia Framework
formed for the transaction of MPEG-21 Digital Items or services related to the MPEG-21 Framework.
The Contract Expression Language (CEL) aims at digitally representing the agreements made in an
environment of ISO/IEC 21000 use. These contracts include those about both transactions of content packed
as Digital Items as well as services provided around this content.
The range of contracts under scope is:
⎯ Contracts about transactions on rights for the exploitation of content as MPEG-21 Digital Items;
⎯ Contracts about the provision of MPEG-21-based services, i.e. delivery, identification, encryption, search
and others.
The aspects represented by CEL contracts include:
⎯ The textual clauses, in natural language as they are in the narrative contract, duly structured;
The operative clauses, as computer language expressions.
However CEL may also be used as electronic format for contracts on the trade of media rights also beyond
the MPEG framework.
The main aspect of CEL contracts are the operative clauses, represented as machine readable deontic
expressions, i.e. the agreed permissions, obligations, and prohibitions, and the associated terms and
conditions.
Besides, the CEL contract includes the identification of the contract itself, its parties, and the possible
relationships with other contracts.
Among the provided features there is the possibility to insert the textual version of the contract and/or of
specific clauses, in particular for the case in which the original contract is narrative, i.e. written in natural
language. Also it is possible to add metadata related to any contract entity and to have encryption of the whole
contract, or any-sub-part of it. As electronic format for a contract document, the agreement of the parties can
be proved by their digital signature.
Eventually CEL provides to the media companies the basic means for the collection of knowledge on held
rights, also derived from multiple contracts, as rights port-folio, for business management purposes.
Various potential benefits can be associated to the use of CEL. Firstly CEL can support the business of media
companies, for product placement and maximizing reuse of archive content, implying also cost reductions in
all rights related activities, e.g. rights clearance. Afterwards, it supports the respect of copyright laws with
respect to new exploitation technologies, also by contributing to the reduction of mistakes with respect to
contract compliance, implying decreasing number of controversies and other cost reductions. In general CEL
aims at increasing the quality of rights information, which gets more reliable and can be integrated with other
© ISO/IEC 2015 – All rights reserved 1
---------------------- Page: 7 ----------------------
ISO/IEC DIS 21000-20
metadata in standard way. This can bring even to improve working conditions and all the decision processes
within media companies.
With respect to the first edition (2013), this second edition of CEL provides: some strengthening of the core
contract part; some reordering within the extension for the exploitation of intellectual property rights, also by
completing the set of facts available for specifying conditions and the addition of a simple payment and
notification extension. The relationship with acts defined in ISO/IEC 21000 part 5 (REL) has been refined.
Finally, a clear mechanism for defining further future extensions is in place.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
IETF RFC 1738, Uniform Resource Locators (URL), December 1994, http://www.ietf.org/rfc/rfc1738.txt
IETF RFC 2141, Uniform Resource Name (URN) Syntax, May 1997, http://www.ietf.org/rfc/rfc2141.txt
IETF RFC 2396, Uniform Resource Identifiers (URI): Generic Syntax, Internet Standards Track Specification,
August 1998, http://www.ietf.org/rfc/rfc2396.txt
IETF RFC 2426, vCard MIME Directory Profile, F. Dawson and T. Howes, September 1998.
http://www.ietf.org/rfc/rfc2426.txt
ISO 639 (all parts), Codes for the representation of names of languages.
ISO 3166 (all parts), Codes for the representation of names of countries and their subdivisions.
ISO 4217, Codes for the representation of currencies and funds.
ISO 15836, Information and documentation — The Dublin Core metadata element set.
ISO/IEC 15938-5, Information technology – Multimedia content description interface – Part 5: Multimedia
description schemes
ISO/IEC 21000-3, Information technology – Multimedia Framework (MPEG-21) – Part 3: Digital Item
Identification
ISO/IEC 21000-5, Information technology – Multimedia Framework (MPEG-21) – Part 5: Rights Expression
Language
ISO/IEC 21000-21, Information technology – Multimedia Framework (MPEG-21) – Part 21 Media Contract
Ontology
ISO, MPEG-7 Classification Schema, http://standards.iso.org/ittf/PubliclyAvailableStandards/MPEG-
7_schema_files/mpeg7-v3.xsd
OWL Web Ontology Language Reference, 10 February 2004, http://www.w3.org/TR/2004/REC-owl-ref-
20040210
OWL 2, OWL 2 Web Ontology Language Document overview, W3C Recommendation, 27 October 2009,
http://www.w3.org/TR/owl2-overview/
RDF/XML, RDF/XML Syntax Specification (Revised), W3C Recommendation, 10 February 2004,
http://www.w3.org/TR/2004/REC-rdf-syntax-grammar-20040210/
2 © ISO/IEC 2015 – All rights reserved
---------------------- Page: 8 ----------------------
ISO/IEC DIS 21000-20
W3C, XML Encryption Syntax and Processing Version 1.1, W3C Working Draft 16 March 2010,
http://www.w3.org/TR/xmlenc-core1/
W3C, XML Schema, XML Schema Part 1: Structures and Part 2: Datatypes, W3C Recommendation, 2 May
2001, http://www.w3.org/TR/2001/REC-xmlschema-1-20010502, http://www.w3.org/TR/2001/REC-
xmlschema-2-20010502.
W3C, XML Signature Syntax and Processing - W3C Recommendation 12 February 2002.
http://www.w3.org/TR/xmldsig-core/.
3 Terms, definitions and abbreviated terms
3.1 Terminology
For the purposes of this document, the following terms and definitions apply.
3.1.1 Action
Something done or performed by a Party (or anyone acting on her behalf). It represent the exercise of a right
or duty.
3.1.2 Deontic expression
The generic entity encompassing the properties of an agreed machine readable contract clause regulating the
Actions of the parties.
3.1.3 MPEG-21 Contract
Representation of agreements formed for the transaction of MPEG-21 Digital Items or services related to the
MPEG-21 Framework.
3.1.4 MPEG-21 Service
System supplying utility in the MPEG-21 Framework.
3.1.5 Obligation
A deontic expression binding one of the parties to execute an Action.
3.1.6 Party
An organization or a user who accepts to respect the deontic expressions defined in the contract and who
expects the other parties in the same contract to do the same.
3.1.7 Permission
A deontic expression allowing one of the parties to execute an Action.
3.1.8 Prohibition
A deontic expression binding one of the parties not to execute an Action.
3.2 Abbreviated terms
For the purposes of this document, the following abbreviations apply.
CEL: Contract Expression Language
© ISO/IEC 2015 – All rights reserved 3
---------------------- Page: 9 ----------------------
ISO/IEC DIS 21000-20
IPRE: Intellectual Property Rights Exploitation
IRI: Internationalized Resource Identifier
MCO: Media Contract Ontology
MPEG: Moving Picture Experts Group
MPEG-7: ISO/IEC 15938
MPEG-21: ISO/IEC 21000
OWL: Web Ontology Language
RDF: Resource Description Framework
REL: Rights Expression Language
URI: Uniform Resource Identifier (IETF Standard is RFC 3986)
URN: Uniform Resource Name (IETF Standard is RFC 2141)
W3C: World Wide Web Consortium
XML: Extensible Markup Language (W3C Recommendation)
4 Conventions
4.1 Document conventions
4.1.1 XML Representation
The syntax of each XML element in the Contract Expression Language is specified using the constructs
provided by XML Schema. XML Schema documents or its fragments are presented in orange boxes.
Omissions are marked with suspension points ([.]).
XML documents or its fragments are presented in gray boxes. Omissions are marked with suspension points
([…]).
This part of ISO/IEC 21000 also makes use of diagrams to express portions of XML Schema, as shown in
Figure 1.
4 © ISO/IEC 2015 – All rights reserved
---------------------- Page: 10 ----------------------
ISO/IEC DIS 21000-20
Optional child
Sequence group
Required child
Parent element
Optional
unbounded
child
Required
unbounded
Choice group
child
Required child
with children
Figure 1 — Sample XML Schema diagram
This schema diagram states which elements are required (boxes with solid outline), those that are optional
(boxes with dashed outline), the number of occurrences of each element (0…), and the lineage between
elements (symbols between elements indicating either a choice, or a sequence).
Figure 2 — Compositors used in XML Schema diagrams
Compositors, as shown in Figure 2, describe (from left to right) respectively a sequence of elements, a choice
of elements and the all model.
Figure 3 — Graphical representation of contract examples
© ISO/IEC 2015 – All rights reserved 5
---------------------- Page: 11 ----------------------
ISO/IEC DIS 21000-20
Graphical description of contract examples, as shown in Figure 3, presents how the elements in a contract
relate between themselves to facilitate understanding of complex representations. FactUnion and
FactIntersection allow the combination of constraints to represent complex relationships between the
constraints defined in this document to represent a contract.
4.2 Namespace prefix conventions
The namespace for CEL core XML Schema is:
urn:mpeg:mpeg21:cel:core:2015
The namespace for CEL extension on exploitation of intellectual property rights XML Schema is:
urn:mpeg:mpeg21:cel:ipre:2015
The namespace for CEL extension on payments and notification XML Schema is:
urn:mpeg:mpeg21:cel:pane:2015
The namespace for CEL extension on MPEG-21 REL standard and multimedia extensions is:
urn:mpeg:mpeg21:cel:rele:2015
4.2.1 Use of prefixes
The CEL makes use of elements defined in other schemas, either given by MPEG-21 or others. The used
namespace prefixes together with their reference is given in Table 1.
Table 1 — Mapping of prefixes to namespaces in examples and text.
6 © ISO/IEC 2015 – All rights reserved
---------------------- Page: 12 ----------------------
ISO/IEC DIS 21000-20
Prefix Corresponding namespace Ref
cel-core urn:mpeg:mpeg21:cel:core:2015 Here
cel-ipre urn:mpeg:mpeg21:cel:ipre:2015 Here
cel-pane urn:mpeg:mpeg21:cel:pane:2015 Here
cel-rele urn:mpeg:mpeg21:cel:rele:2015 Here
dc http://purl.org/dc/elements/1.1/ ISO 15836
dii urn:mpeg:mpeg21:2002:01-DII-NS ISO/IEC
21000-3
dsig http://www.w3.org/2000/09/xmldsig# W3C XML
Signature
Syntax and
Processing
rel-mx urn:mpeg:mpeg21:2003:01-REL-MX-NS ISO/IEC
21000-5
rel-r urn:mpeg:mpeg21:2003:01-REL-R-NS ISO/IEC
21000-5
rel-sx urn:mpeg:mpeg21:2003:01-REL-SX-NS ISO/IEC
21000-5
xenc http://www.w3.org/2001/04/xmlenc# W3C XML
Encryption
Syntax and
Processing
xsd http://www.w3.org/2001/XMLSchema W3C XML
Schema
xsi http://www.w3.org/2001/XMLSchema-instance W3C XML
Schema
Instance
5 Relationship to other ISO/IEC 21000 Parts
The Digital Item is the fundamental unit of distribution and transaction in the Multimedia Framework. While the
different parts of ISO/IEC 21000 deal with the components and different aspects of Digital Items, together they
form a complete integrated interoperable framework. This clause describes the relationship of this part of
ISO/IEC 21000 with the other parts of ISO/IEC 21000 in addressing the representation of the agreements for
the aforementioned transactions.
A contract represented following this part of ISO/IEC 21000 may become a part of a Digital Item (whose
declaration is given with the ISO/IEC 21000-2 Part). If so, it will be declared with the Type element of ISO/IEC
21000-3 pointing to the CEL URI, as described in Annex B.3.
This part of ISO/IEC 21000 has the aim, as ISO/IEC 21000-21, of digitally representing contracts information.
CEL enables the structured representation of contracts‘ information making use of XML, while MCO provides
their semantic representation by means of OWL or RDF. Both parts share the goal of defining a contract
document able to provide the information listed in Clause 6.1 and they share the semantics for Actions, Facts
and Services.
This part of ISO/IEC 21000 also supports the expression of Rights and Conditions as defined in ISO/IEC
21000-5.
© ISO/IEC 2015 – All rights reserved 7
---------------------- Page: 13 ----------------------
ISO/IEC DIS 21000-20
6 Overview
6.1 General aspects
A Contract Expression Language (CEL) contract is a document providing the following information, optional
unless otherwise stated:
⎯ Identification of the contract itself – Required.
⎯ Possible relationships with other contracts.
⎯ The Parties – Required.
⎯ The textual version of the contract.
⎯ A number of textual clauses which can be referenced by the operative part element.
⎯ The Object of the contract (Content or Service) – Required.
⎯ The Operative part, containing the contract information which have to be machine readable (deontic
expressions, links to textual clauses) – Required.
CEL supports the possibility to encrypt either the whole contract or part of it.
CEL aims at providing the structural elements to syntactically represent operative clauses, in a machine-
readable form.
6.2 Syntactic representation
A Contract document defined by CEL shall be compliant to the XML representation defined in Clause 7. The
document format is specified by an XML Schema. Any representation of a contract document defined by CEL
supports the possibility of encrypting either the whole contract or part of it.
Contract documents shall validate against the CEL XML Schema, which is provided, as normative
specification, in Annex A. A detailed description of the structured representation is given in Clause 7.
7 Contract Structured Representation
7.1 Introduction
CEL standard specification enables the structured representation of digital media contracts by means of XML.
To this end, the CEL core XML schema has been defined It normatively defines the core elements for media
contracts. Its IRI is:
urn:mpeg:mpeg21:cel:core:2015
Media contracts consist of deontic expressions which permit, obligate or prohibit users to execute generic
actions over digital media if the imposed conditions are fulfilled. Common actions and conditions in media
contracts have been defined as acts and constraints in the XML CEL extension on exploitation of intellectual
property rights. Its IRI is:
urn:mpeg:mpeg21:cel:ipre:2015
Moreover, it is needed to represent the basic information about payment terms agreed in media contracts and
about agreed notification actions intended to inform the contract parties, or other indicated users, about the
occurrence of relevant events. This information is defined in the XML CEL extension on payments and
notification. Its IRI is:
8 © ISO/IEC 2015 – All rights reserved
---------------------- Page: 14 ----------------------
ISO/IEC DIS 21000-20
urn:mpeg:mpeg21:cel:pane:2015
Finally, to facilitate reference to MPEG-21 Rights Expression Language Standard and Multimedia extensions,
a separated schema is provided. Contracts not making use of actions or constraints defined in this schema,
do not need to include all of them. Its IRI is:
urn:mpeg:mpeg21:cel:rele:2015
MPEG-21 CEL contract documents shall validate against the XML Schema specification(s) described in this
subclause.
7.2 XML Schema definition
7.2.1 Contract element and main structure
The root element of a CEL contract is the cel-core:Contract element, which includes the structured
representation of the contract by means of deontic clauses, as well as the original text version of the contract.
It also provides mechanisms for relating the narrative clauses of the contract with its structured XML
representation.
The structure of the cel-core:Contract element is depicted in Figure 4. Its child elements are:
⎯ optionally a choice of cel-core:TextVersion containing the whole narrative contract as plain text; or
cel-core:EncryptedTextVersion containing an encrypted version of the whole narrative contract.
⎯ cel-core:Metadata, optionally including metadata such as contract author, contract language, etc.
⎯ cel-core:ContractsRelated, optionally including references to pre-existing contracts the validity of
which might be affected by the present one.
⎯ cel-core:Party, the number of parties is open; 0 means that the contract is a template.
⎯ cel-core:Body, exactly one body element is mandatory, with the contract clauses.
⎯ cel-core:EncryptedContract, a full version of an encrypted contract. If it is present, the rest of
elements do not appear.
© ISO/IEC 2015 – All rights reserved 9
---------------------- Pag
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.