Constraint-based automation of multimedia presentation assembly

In this paper, we present a methodology for automated construction of multimedia presentations. Semantic coherency of a multimedia presentation is expressed in terms of presentation inclusion and exclusion constraints. When a user specifies a set of segments for a presentation, the multimedia database system adds segments into and/or deletes segments from the set in order to satisfy the inclusion and exclusion constraints. We discuss the consistency and the satisfiability of inclusion and exclusion constraints when exclusion is allowed. Users express a presentation query by (a) pointing and clicking to an initial set of desired multimedia segments to be included into the presentation, and (b) specifying an upper bound on the time length of the presentation. The multimedia database system then finds the set of segments satisfying the inclusion-exclusion constraints and the time bound. Using priorities for segments and inclusion constraints, we give two algorithms for automated presentation assembly and discuss their complexity. To automate the assembly of a presentation with concurrent presentation streams, we introduce presentation organization constraints that are incorporated into the multimedia data model, independent of any presentation. We define four types of presentation organization constraints that, together with an underlying database ordering, allow us to obtain a unique presentation graph for a given set of multimedia segments. We briefly summarize a prototype system that fully incorporates the algorithms for the segment selection problem.