Building temporal structures in a layered multimedia data model

The Layered Multimedia Data Model (LMDM) aids in the specification of multimedia compositions by dividing the problem into smaller, more manageable pieces. In this paper we describe the lower two layers of the LMDM, the Data Definition Layer, which allows the specification of multimedia objects in a database, and the Data Manipulation Layer, which allows the specification of temporal structures built from those objects. Several examples demonstrate the advantages of the layered paradigm: simple specifications, and modular, reusable components.