I.R.I.S. Working Group

Interoperable Multimedia Retrieval in Distributed Systems

The MPEG Query Format (part 12 of MPEG-7)

(Further reading & legal notice available at: I.R.I.S. Working Group)

Digital media content is being generated, distributed and stored worldwide at an ever increasing rate. In consequence, vast repositories of multimedia content are becoming commonplace. This is leading to an increased urgency to find and standardise solutions for accessing and querying those multimedia repositories. Currently, almost every multimedia repository offers a different retrieval interface and multimedia metadata description format, preventing unified and efficient access to those repositories. In this context, ISO/IEC SC29WG11 (more commonly known as MPEG) established the MPEG Query Format (MPQF) standardisation to create a standard interface for media repositories. The MPQF standardizes messages from and to multimedia repositories and provides extended functionalities for service discovery, service selection and service capability description.

The MPEG Query Format supports among others the following main features:

  • MPQF bases on XML and is defined by an XML Schema
  • decoupled from any other metadata standard (also MPEG-7)
  • support for any XML based MM metadata description
  • MPQF divided into 3 main categories (Input Query Format, Output Query Format, Query Management Tools)
  • rich set of Multimedia query types (e.g., QueryByMedia, QueryByDescription, QueryByFreeText, Spatial Query, TemporalQuery, SpatioTemporalQuery, QueryByXQuery, etc.)
  • service capability description
  • service discovery functionality
  • support for synchronous and asynchronous mode
  • allows the definition of the content as well as structure of the result set
  • modular filter architecture
  • assign preference value to every condition
  • join functionality
  • specification of data granularity
  • combines exact match and fuzzy retrieval

Possible scenario for the use of the MPEG Query Format: