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A Technical Report has been written to describe the multimedia framework and its architectural elements together with the functional requirements for their specification that was formally approved in September 2001.

• Define a 'vision' for a multimedia framework to enable transparent and augmented use of multimedia resources across a wide range of networks and devices to meet the needs of all users.
• Achieve the integration of components and standards to facilitate harmonisation of 'technologies' for the creation, management, transport, manipulation, distribution, and consumption of digital items.
• Define a 'strategy' for achieving a multimedia framework by the development of specifications and standards based on well-defined functional requirements through collaboration with other bodies.

The purpose of the Digital Item Declaration (DID) specification is to describe a set of abstract terms and concepts to form a useful model for defining Digital Items. Within this model, a Digital Item is the digital representation of “a work”, and as such, it is the thing that is acted upon (managed, described, exchanged, collected, etc.) within the model.

The DID technology is described in three normative sections:

• Model: The Digital Item Declaration Model describes a set of abstract terms and concepts to form a useful model for defining Digital Items. Within this model, a Digital Item is the digital representation of “a work”, and as such, it is the thing that is acted upon (managed, described, exchanged, collected, etc.) within the model.
• Representation: Normative description of the syntax and semantics of each of the Digital Item Declaration elements, as represented in XML. This section also contains some non-normative examples for illustrative purposes.
• Schema: Normative XML schema comprising the entire grammar of the Digital Item Declaration representation in XML.

The scope of the Digital Item Identification (DII) specification includes:

• How to uniquely identify Digital Items and parts thereof (including resources);
• How to uniquely identify IP related to the Digital Items (and parts thereof), for example abstractions;
• How to uniquely identify Description Schemes;
• How to use identifiers to link Digital Items with related information such as descriptive metadata.
• How to identify different types if Digital Items.

The DII specification does not specify new identification systems for the content elements for which identification and description schemes already exist.

The aim of MPEG-21 Intellectual Property Management and Protection (IPMP) Components is to allow controls on the flow and usage of Digital Items throughout their lifecycle.

It exists in two parts:

• IPMP Digital Item Declaration Language, which provides for a protected Representation of the DID Model.
• IPMP Information schemas, defining structures for expressing information relating to the protection of content, including tools, mechanisms and licenses.

A Rights Expression Language is seen as a machine-readable language that can declare rights and permissions using the terms as defined in the Rights Data Dictionary.

The REL is intended to provide flexible, interoperable mechanisms to support transparent and augmented use of digital resources in publishing, distributing, and consuming of digital movies, digital music, electronic books, broadcasting, interactive games, computer software and other creations in digital form, in a way that protects digital content and honours the rights, conditions, and fees specified for digital contents.

The Rights Data Dictionary (RDD) comprises a set of clear, consistent, structured, integrated and uniquely identified Terms to support the MPEG-21 Rights Expression Language.

The structure of the dictionary is specified, along with a methodology for creating the dictionary. The means by which further Terms may be defined is also explained.

The goal of the Terminals and Networks key element is to achieve interoperable transparent access to (distributed) advanced multimedia content by shielding users from network and terminal installation, management and implementation issues. This will enable the provision of network and terminal resources on demand to form user communities where multimedia content can be created and shared, always with the agreed/contracted quality, reliability and flexibility, allowing the multimedia applications to connect diverse sets of Users, such that the quality of the user experience will be guaranteed.

Towards this goal the adaptation of Digital Items is required. It is important to emphasise that the adaptation engines themselves are non-normative tools of Digital Item Adaptation. However, descriptions and format-independent mechanisms that provide support for Digital Item Adaptation in terms of resource adaptation, descriptor adaptation, and/or Quality of Service management are within the scope of the requirements.

The reference software of ISO/IEC 21000 serves three main purposes:

• Validation of the written specification of the several MPEG-21 parts.
• Clarification of the written specification of the several MPEG-21 parts.
• Conformance testing for checking interoperability for the various applications against the reference software which aims to be compliant to MPEG-21.

In other word, reference software implements the normative parts of the written specifications. Additionally, so-called utility software is provided which demonstrates how to use the reference software in various application scenarios.

An MPEG-21 Digital Item can be a complex collection of information. Both still and dynamic media (e.g. images and movies) can be included, as well as Digital Item information, meta-data, layout information, and so on. It can include both textual data (e.g. XML) and binary data (e.g. an MPEG-4 presentation or a still picture). For this reason, the MPEG-21 file format will inherit several concepts from MP4, in order to make ‘multi-purpose’ files possible. A dual-purpose MP4 and MP21 file, for example, would play just the MPEG-4 data on an MP4 player, and would play the MPEG-21 data on an MP21 player.

Digital Item Processing specifies tools enabling Users to provide suggested interactions with Digital Items, thereby enabling the inclusion of a dynamic aspect to the static declaration of Digital Items.

The term persistent association is used to categorise all the techniques for managing identification and description with content. This will include the carriage of identifiers within the context of different content file and transport formats, including file headers and embedded into content as a watermark. It also encompasses the ability for identifiers associated with content to be protected against their unauthorised removal and modification.

The test bed is mainly composed of a streaming player, a media server, and an IP network emulator. This document describes the API of each components of the test bed to facilitate a component oriented development process. This platform provides a flexible and fair test environment for evaluating scalable media streaming technologies for MPEG contents over IP networks.

The purpose of this part of MPEG-21 is to define new scalable video coding technology with high compression performance. Examples of potential applications that can benefit from such improved scalable coding technologies are: Internet video, wireless LAN video, mobile wireless video for conversational, VOD, and live broadcasting purposes, multi-channel content production and distribution, surveillance-and-storage applications, and layered protection of contents.

Event Reporting, specifies:

• How to express Event Report Requests (ER-R) that contain information about which events to report, what information is to be reported and to whom;
• How to express Event Reports (ER) which are created by an MPEG-21 Peer in response to an Event Report Request when the condition of the ER-R is met; and
• How to use Digital Items – as specified in part 2 of MPEG-21 – to package Event Reports and Event Report Request.

Part 16 of MPEG-21 specifies a binary format for XML-based descriptions as standardized within other parts of MPEG-21. This enables the efficient interchange or storage of MPEG-21 descriptions.

This part specifies a normative syntax for URI Fragment Identifiers to be used for addressing parts of any resource whose Internet Media Type is one of:

• audio/mpeg
• video/mpeg