Phd

The need for technological solutions to
these challenges is motivating the MPEG-21 Multimedia Framework initiative that
aims to enable the transparent and augmented use of multimedia resources across
a wide range of networks and devices..

MPEG-21 is based on two essential concepts:
the definition of a fundamental unit of distribution and transaction (the
Digital Item) and the concept of Users interacting with Digital Items. The
Digital Items can be considered the “what” of the Multimedia Framework (e.g., a
video collection, a music album) and the Users can be considered the “who” of
the Multimedia Framework.

• 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 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.

5.2.1     
Container

5.2.2     
Item

The relationship between items and
Digital Items (as defined in ISO/IEC 21000-1:2001, MPEG-21 Vision,
Technologies and Strategy) could be stated as follows: items are
declarative representations of Digital Items.

5.2.3     
Component

5.2.4     
Anchor

An anchor binds descriptors to
a fragment, which corresponds to a specific location or range within a
resource.

5.2.5     
Descriptor

A descriptor associates information with the enclosing
element. This information may be a component (such as a thumbnail of an
image, or a text component), or a textual statement. 

5.2.6     
Condition

A condition describes the enclosing element as being
optional, and links it to the selection(s) that affect its inclusion

5.2.7     
Choice

A choice describes a set of related
selections that can affect the configuration of an item

5.2.8     
Selection

A selection describes a specific
decision that will affect one or more conditions somewhere within an
item

5.2.9     
Annotation

An annotation describes a set of information about
another identified element of the model without altering or adding to that
element.

5.2.10  Assertion

An assertion defines a full or
partially configured state of a choice by asserting true, false or
undecided values for some number of predicates associated with the
selections for that choice.

.2.11  Resource

A resource is an individually
identifiable asset such as a video or audio clip, an image, or a textual
asset

5.2.12  Fragment

A fragment unambiguously designates a
specific point or range within a resource

5.2.13  Statement

A statement is a literal textual
value that contains information

5.2.14  Predicate

A predicate is an unambiguously
identifiable Declaration that can be true, false or undecided