||The neutrality of this article is disputed. (June 2009)|
The MPEG-21 standard, from the Moving Picture Experts Group, aims at defining an open framework for multimedia applications. MPEG-21 is ratified in the standards ISO/IEC 21000 - Multimedia framework (MPEG-21).
MPEG-21 is based on two essential concepts:
- definition of a Digital Item (a fundamental unit of distribution and transaction)
- users interacting with Digital Items
Digital Items can be considered the kernel of the Multimedia Framework and the users can be considered as who interacts with them inside the Multimedia Framework. At its most basic level, MPEG-21 provides a framework in which one user interacts with another one, and the object of that interaction is a Digital Item. Due to that, we could say that the main objective of the MPEG-21 is to define the technology needed to support users to exchange, access, consume, trade or manipulate Digital Items in an efficient and transparent way.
MPEG-21 Part 9: File Format defined the storage of an MPEG-21 Digital Item in a file format based on the ISO base media file format, with some or all of Digital Item's ancillary data (such as movies, images or other non-XML data) within the same file. It uses filename extensions .m21 or .mp21 and MIME type application/mp21.
Digital Rights Management 
MPEG-21 defines also a "Rights Expression Language" standard as means of managing restrictions for digital content usage. As an XML-based standard, MPEG-21 is designed to communicate machine-readable license information and do so in a "ubiquitous, unambiguous and secure" manner.
Among the aspirations for this standard, that the industry hope will put an end to file sharing, is that it will constitute: "A normative open framework for multimedia delivery and consumption for use by all the players in the delivery and consumption chain. This open framework will provide content creators, producers, distributors and service providers with equal opportunities in the MPEG-21 enabled open market."
See also 
- ISO. "ISO/IEC TR 21000-1:2001 - Information technology -- Multimedia framework (MPEG-21) -- Part 1: Vision, Technologies and Strategy". Retrieved 2009-10-31.
- ISO. "ISO/IEC 21000-2:2003 - Information technology -- Multimedia framework (MPEG-21) -- Part 2: Digital Item Declaration". Retrieved 2009-10-31.
- ISO. "ISO/IEC 21000-3:2003 - Information technology -- Multimedia framework (MPEG-21) -- Part 3: Digital Item Identification". Retrieved 2009-10-31.
- MPEG. "About MPEG - Achievements". chiariglione.org. Retrieved 2009-10-31.[dead link]
- MPEG. "Terms of Reference". chiariglione.org. Retrieved 2009-10-31.[dead link]
- MPEG. "MPEG standards". chiariglione.org. Retrieved 2009-10-31.[dead link]
- ISO (2006). "MPEG-21 File Format white paper - Proposal". chiariglione.org. Retrieved 2010-08-20.
- ISO/IEC 21000-9 First edition, 2005-07-01, AMENDMENT 1 2008-10-01, Information technology — Multimedia framework (MPEG-21) — Part 9: File Format AMENDMENT 1: MIME type registration, retrieved 2010-08-20
Further reading 
- Framework Overview
- Part 1: Vision, Technologies and Strategy
- 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 (.m21 or .mp21)
- Part 10: Digital Item Processing, C++ bindings and Session Mobility
- Part 11: Evaluation Tools for Persistent Association
- Part 15: Event Reporting
- Part 17: Fragment Identification for MPEG Resources
- Part 18: Digital Item Streaming
- Part 19: Media Value Chain Ontology (MVCO)
- Part 20: Contract Expression Language
- Part 21: Media Contract Ontology
- MPEG-21 Overview
- MPEG-21 Resources section of the MPEG Industry Forum web site
- MPEG-21 Multimedia Framework (Overview and State of the Art)
- MPEG-21 Overview (blog)
- MPEG-7/-21 Community Portal
- MPEG-21 schema files