In this paper, we consider the problem of querying multimedia presentations based on content information. We believe that presentations should become an integral part of multimedia database systems and users should be able to store, query, and, possibly, manipulate multimedia presentations using a single database management system software. Multimedia presentations are modeled as presentation graphs, which are directed acyclic graphs that visually specify multimedia presentations. Each node of a presentation graph represents a media stream.
Edges depict sequential or concurrent playout of streams during the presentation.
Information captured in each individual stream and the presentation order of streams constitute the content information of the presentation. Querying multimedia presentation graphs based on content is important for the retrieval of information from a database. We present a graph data model for the specification of multimedia presentations and discuss query languages as effective tools to query and manipulate multimedia presentation graphs with respect to content information. Next, Connected, and Until, together with path formulas. These constructs allow us to specify and query paths along a presentation graph.