scope:

This International Standard defines a Multimedia Content Description Interface, specifying a series of interfaces from system to application level to allow disparate systems to interchange information about multimedia content. It describes the architecture for systems, a language for extensions and specific applications, description tools in the audio and visual domains, as well as tools that are not specific to audio-visual domains. As a whole, this International Standard encompassing all of the aforementioned components is known as "MPEG-7." MPEG-7 is divided into eight parts (as defined in the Foreword). This part of the MPEG-7 Standard (Part 4: Audio) specifies description tools that pertain to multimedia in the audio domain. See below for further details of application. This part of the MPEG-7 Standard is intended to be implemented in conjunction with other parts of the standard. In particular, MPEG-7 Part 4: Audio assumes knowledge of Part 2: Description Definition Language (DDL) in its normative syntactic definitions of Descriptors and Description Schemes. This part of the standard also has dependencies upon clauses in Part 5: Multimedia Description Schemes, namely many of the fundamental Description Schemes that extend the basic type capabilities of the DDL. MPEG-7 is an extensible standard. The method to extend the standard beyond the Description Schemes provided in the standard is to define new ones in the DDL, and to make those DSs available with the instantiated descriptions. Further details are available in Part 2. To avoid duplicate functionality with other parts of the standard, the DDL is the only extension facility provided