Date: May. 12, 2001
Link: http://www.expway.tv/bim/bim.html
Source Author or Organization: CRC for Distributed Systems Technology

In MPEG-7 metadata are expressed in XML. The W3C's XML Schema Language is used to define datastructures. A large library of types are defined to describe many aspects of a multimedia document ranging from low level features (colors, movement, etc.) to high level RDF-like descriptions.

For that purpose MPEG-7 designed a binary encoding format somewhat similar to ASN-1. XML can be easily encoded, streamed, and filtered. XML descriptions can be sent whole or synchronously streamed within an AV stream (MPEG-2 or MPEG-4).

The codec is dynamically generated as expressed using XML Schemas. Compression ratios show that elements can be represented by few bits in average (sometimes less than one bit), values are coded using specific datatype encodings.