A Uniform Resource Name (URN) Namespace for the Motion Picture Experts Group (MPEG)
A permanent naming system for standards and resources produced by MPEG.
Smith, J., "A Uniform Resource Name (URN) Namespace for the Motion Picture Experts Group (MPEG)", RFC 3614, DOI 10.17487/RFC3614, September 2003, <https://www.rfc-editor.org/info/rfc3614>.
@misc{rfc3614,
series = {Request for Comments},
number = 3614,
howpublished = {RFC 3614},
publisher = {RFC Editor},
doi = {10.17487/RFC3614},
url = {https://www.rfc-editor.org/info/rfc3614},
author = {J. Smith},
title = {{A Uniform Resource Name (URN) Namespace for the Motion Picture Experts Group (MPEG)}},
pagetotal = 6,
year = 2003,
month = sep,
} RFC text
Contents
Network Working Group J. Smith
Request for Comments: 3614 IBM T. J. Watson Research Center
Category: Informational September 2003
A Uniform Resource Name (URN) Namespace for the
Motion Picture Experts Group (MPEG)
Status of this Memo
This memo provides information for the Internet community. It does
not specify an Internet standard of any kind. Distribution of this
memo is unlimited.
Copyright Notice
Copyright (C) The Internet Society (2003). All Rights Reserved.
Abstract
This document describes a Uniform Resource Name (URN) namespace for
the Motion Picture Experts Group (MPEG) for naming persistent
resources as part of the MPEG standards. Example resources include
technical documents and specifications, eXtensible Markup Language
(XML) Schemas, classification schemes, XML Document Type Definitions
(DTDs), namespaces, style sheets, media assets, and other types of
resources produced or managed by MPEG.
1. Introduction
MPEG is a working group of the International Organization for
Standardization (ISO) and International Engineering Consortium (IEC)
in charge of the development of standards for coded representation of
digital audio and video. MPEG has produced MPEG-1, the standard on
which such products as Video CD and MP3 are based, MPEG-2, the
standard on which such products as Digital Television set top boxes
and DVD are based, MPEG-4, the standard for multimedia for the fixed
and mobile web, and MPEG-7, "Multimedia Content Description
Interface", the standard for description and search of audio and
visual content. Work on MPEG-21, "Multimedia Framework" is currently
underway.
MPEG would like to assign unique, permanent, location-independent
names based on URNs for some resources it produces or manages.
This namespace specification is for a formal namespace.
2. Specification Template
Namespace ID:
"mpeg"
Registration Information:
Version: 1
Date: 2001-11-20
Declared registrant of the namespace:
Name: John R. Smith
Title: Chair, MPEG MDS Subgroup
Affiliation: IBM T. J. Watson Research Center
Address: 30 Saw Mill River Road
Hawthorne, NY 10532 USA
Phone: +1 (914) 784-7320
Email: jrsmith@watson.ibm.com
Declaration of structure:
URNs assigned by MPEG will have the following hierarchical
structure based on the organizational structure of the MPEG
standards:
urn:mpeg:{standard name}:{assigned US-ASCII string}
where "{standard name}" is a US-ASCII string that conforms to URN
Syntax requirements ([RFC2141]) and corresponds to the name of an
MPEG standard (such as "mpeg1", "mpeg2", "mpeg4", "mpeg7",
"mpeg21", and
"{assigned US-ASCII string}" is a US-ASCII string that conforms to
URN Syntax requirements ([RFC2141]).
The individual URNs shall be assigned by MPEG through the process
of development of MPEG standards.
Relevant ancillary documentation:
None
Identifier uniqueness considerations:
MPEG shall establish unique identifiers as appropriate.
Uniqueness is guaranteed as long as the assigned string is never
reassigned for a given standard name and that the standard name is
never reassigned.
Identifier persistence considerations:
MPEG is committed to maintaining the accessibility and persistence
of all resources that are officially assigned URNs by the
organization.
Persistence of identifiers is dependent upon suitable delegation
of resolution at the level of "standard name"(s), and persistence
of standard name assignment.
Process of identifier assignment:
Assignment is limited to the owner and those authorities that are
specifically designated by the owner. MPEG may designate portions
of its namespace for assignment by other parties.
Process of identifier resolution:
The owner will develop and maintain "URN catalogs" that map all
assigned URNs to Uniform Resource Locators (URLs) specifically to
enable Web-based resolution of named resources. In the future an
interactive online resolution system may be developed to automate
this process.
The owner will authorize additional resolution services as
appropriate.
Rules for Lexical Equivalence:
The "standard name" is case-insensitive. Thus, the portion of the
URN:
urn:mpeg:{standard name}:
is case-insensitive for matches. The remainder of the identifier
must be considered case-sensitive.
Conformance with URN Syntax:
No special considerations.
Validation mechanism:
None specified. The owner will develop and maintain URN catalogs.
The presence of a URN in a catalog indicates that it is valid.
Scope:
Global
3. Examples
The following examples are not guaranteed to be real. They are
presented for pedagogical reasons only.
urn:mpeg:mpeg7:schema:2001
urn:mpeg:mpeg7:cs:VideoDomainCS:2001
urn:mpeg:mpeg7:cs:GenreCS:2001
urn:mpeg:mpeg7:cs:ContentCS:2001
4. Namespace Considerations
URN assignment procedures:
The individual URNs shall be assigned through the process of
development of MPEG standards by the Moving Picture Experts Group
(MPEG), which is a working group of ISO/IEC.
URN resolution/delegation:
The resolution and delegation shall be determined through the
process of development of MPEG standards by the Moving Picture
Experts Group (MPEG). MPEG has developed requests for
registration authority for MPEG-7 classification schemes and
MPEG-21 identification systems. These registration authorities
shall be responsible for corresponding parts of MPEG namespace.
Type of resources to be identified:
Types of resources to be identified include XML schema definition
files, classification schemes, identification systems.
Type of services to be supported:
Types of services supported include controlled term lookup in
classification schemes, resolution of ids in identification
systems.
5. Community Considerations
Open assignment and use of identifiers within the namespace:
With on-going development of MPEG standards, MPEG shall establish
requirements for assignment and use of identifiers within MPEG
namespace. MPEG has already established requirements for
assignment and use of MPEG-7 classification schemes under MPEG
namespace. A registration authority shall have the responsibility
for processing third party requests for registering classification
schemes.
Open operation of resolution servers for the namespace (server):
With on-going development of MPEG standards, MPEG shall establish
requirements and seek candidates for operating resolution servers
as appropriate.
Creation of software that can meaningfully resolve and access
services for the namespace (client):
With on-going development of MPEG standards, MPEG shall develop
reference software implementations of its standards.
6. Security Considerations
There are no additional security considerations other than those
normally associated with the use and resolution of URNs in general.
7. IANA Considerations
The IANA has registered formal URN namespace 12, to MPEG within the
IANA registry of URN NIDs.
8. Normative References
[RFC2141] Moats, R., "URN Syntax", RFC 2141, May 1997.
9. Author's Address
John R. Smith
IBM T. J. Watson Research Center
30 Saw Mill River Road
Hawthorne, NY 10532 USA
Phone: 1 (914) 784-7320
EMail: jrsmith@watson.ibm.com
10. Full Copyright Statement
Copyright (C) The Internet Society (2003). All Rights Reserved.
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included on all such copies and derivative works. However, this
document itself may not be modified in any way, such as by removing
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Internet organizations, except as needed for the purpose of
developing Internet standards in which case the procedures for
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followed, or as required to translate it into languages other than
English.
The limited permissions granted above are perpetual and will not be
revoked by the Internet Society or its successors or assignees.
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Acknowledgement
Funding for the RFC Editor function is currently provided by the
Internet Society.
AI ELI5
On this page
§1MPEG and Its Resource Naming Needs
The Motion Picture Experts Group (MPEG) is a working group of ISO and IEC that develops international standards for coded representation of digital audio and video. MPEG has produced MPEG-1 (foundation for Video CD and MP3), MPEG-2 (foundation for DVD and digital television), MPEG-4 (multimedia for the web), MPEG-7 (multimedia content description), and is developing MPEG-21 (multimedia framework).
MPEG produces many resources beyond protocol specifications: XML schemas, classification schemes, identification systems, technical documents, and other standards-related materials. To make these resources discoverable and persistent, MPEG requested a formal URN namespace. A Uniform Resource Name (URN) is a persistent, location-independent identifier that can be resolved to find the actual resource, no matter where it is stored.
MPEG makes video standards and tools. They need permanent names for each schema, document, and definition so people can find them anywhere.
§2URN Structure and Naming Hierarchy
MPEG URNs follow the form urn:mpeg:{standard name}:{assigned US-ASCII string}. The standard name corresponds to an MPEG standard like mpeg1, mpeg2, mpeg4, mpeg7, or mpeg21. The assigned string is any US-ASCII string that conforms to URN syntax.
For example, valid MPEG URNs include urn:mpeg:mpeg7:schema:2001 and urn:mpeg:mpeg7:cs:GenreCS:2001. The standard name is case-insensitive for matching purposes, meaning MPEG7 and mpeg7 refer to the same standard. Everything after the standard name is case-sensitive.
Uniqueness is guaranteed as long as the assigned string is never reused for a given standard and the standard name itself is never reassigned. Each URN is assigned through the development process of the MPEG standards.
Names look like urn:mpeg:mpeg7:myresource. The first part says what MPEG standard, the second part says what specific thing. MPEG decides what gets a name.
§3Assignment, Resolution, and Persistence
MPEG controls all URN assignments, though it may designate portions of its namespace for assignment by other parties (such as registration authorities for MPEG-7 classification schemes). Individual URNs are assigned through the normal MPEG standards development process.
MPEG develops and maintains URN catalogs that map all assigned URNs to Uniform Resource Locators (URLs), enabling Web-based resolution of named resources. In the future, MPEG may develop an interactive online resolution system to automate the process. The presence of a URN in a catalog indicates that it is valid.
MPEG is committed to maintaining the accessibility and persistence of all resources officially assigned URNs. This commitment depends on proper delegation at the standard-name level and persistence of standard-name assignments. MPEG may authorize additional resolution services as needed.
MPEG keeps a directory mapping each permanent name to where the file actually is. Anyone can ask MPEG 'where is this name?' and get pointed to the resource.
§4Types of Resources and Services
Resources that can be named include XML Schema Definition files, classification schemes, identification systems, and other materials produced as part of MPEG standards. The namespace is broad enough to cover the full range of MPEG's output.
Services that can be supported include controlled term lookup in classification schemes and resolution of identifiers in identification systems. As MPEG standards evolve and new resource types are produced, the namespace can accommodate them without modification, since MPEG controls the structure and can add new standard names as needed.
MPEG can name schemas, lists of categories, identification codes, and anything else it produces. People can use the names to look things up.
§5Community and Future Development
With ongoing development of MPEG standards, MPEG establishes requirements for assignment and use of identifiers within the namespace. For example, registration authorities have responsibility for processing third-party requests to register MPEG-7 classification schemes. MPEG continues to develop reference software implementations to help clients resolve and use URNs in MPEG standards.
This URN namespace allows MPEG to maintain persistence and discoverability of its resources over time, supporting the international multimedia standards community in adopting and implementing MPEG specifications.
MPEG keeps adding new standards, and the naming system grows with them. The permanent names ensure that old and new resources can always be found.