| This thesis proposes database techniques for efficient management of multimedia presentations. The techniques proposed in the thesis include multimedia database design, buffer management techniques for multimedia servers, graphical query user interfaces, efficient graph query processing techniques, and electronic books for multimedia presentations.; The problem of querying multimedia presentations based on content information 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 application/database management system software. In this thesis we propose such a database management system, called ViSiOn.; Most multimedia servers reported in the literature are designed to serve multiple and independent video/audio streams. We think that multimedia servers also need to serve complete presentations. Multimedia presentations provide unique opportunities to develop algorithms for buffer management and admission control, as execution-time consumption requirements of presentations are known a priori. In our work, we examine presentations in three different domains (heavyweight, middleweight, and lightweight) and provide buffer management and admission control algorithms for the three domains. We propose two improvements (flattening and dynamic-adjustments) on the schedules created for heavyweight presentations.; We model multimedia presentations 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 a 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. To query the information flow throughout a multimedia presentation as well as in each individual multimedia stream, we use temporal operators Next, Connected, and Until, together with path formulas. These constructs allow us to specify and query paths along a presentation graph. We present an icon-based, graphical query language, GVISUAL that provides iconic representations for these constructs and a user-friendly graphical interface for query specification.; To evaluate queries with path algebra expressions, we propose the node code system. In the node code system, the nodes of a presentation graph are assigned binary codes (node codes) that are used to represent nodes and paths in a presentation graph. Using node codes makes it easy to find parent-child, predecessor-successor relationships between nodes. A pair of node codes for connected nodes uniquely identifies a path, and allows efficient set-at-a-time evaluations of path algebra expressions. In this thesis, we present the node code representation of nodes and paths in multimedia presentation graphs, and provide efficient algorithms and optimization techniques for the evaluation of queries with path algebra expressions.; Electronic books are typically large, usually contain hyper-linked table of contents, indexed search facilities on keywords, and occasionally have multimedia data such as images, maps, and audio/video streams. Most of the time, the sheer size of these electronic books and their static and black box nature impede the user in effectively learning from such books. We use the term electronic book as an application that contains and makes extensive use of a multimedia database and multimedia presentations stored in it. In this thesis, we use new and extended database techniques for electronic books containing hyperlinked text, instructor's audio/video clips, slides, animation, still images, etc. as well as content-based information about these data. |
