INTERVAL-BASED CONCEPTUAL MODELS FOR TIME-DEPENDENT MULTIMEDIA DATA

Multimedia data often have time dependencies that must be satisfied at presentation time. To support a general-purpose multimedia informatio n system, these timing relationships must be managed to provide utilit y to both the data presentation system and the multimedia author. In t his paper we propose new conceptual models for capturing these timing relationships and managing them as part of a database. Specifically, w e introduce and define n-ary and reverse temporal relations along with their temporal constraints. These new relations are a generalization of our earlier temporal models and establish the basis for conceptual database structures and temporal access control algorithms to facilita te forward, reverse, and partial-interval evaluation during multimedia object playout. The proposed relations are defined to ensure a proper ty of monotonically increasing playout deadlines to facilitate both re al-time deadline-driven playout scheduling or optimistic interval-base d process playout. Furthermore, we show a translation of the conceptua l models to a structure suitable for a relational database.