Synchronized Hypermedia Documents: a Model and its Applications

Authoring, delivering and presenting hypermedia documents is a complex task, since such documents can contain a large number of components bound by multiple temporal and layout constraints. Media items are files which have to be arranged on the screen and synchronized to be displayed to the user. The growth of network bandwidth encourages the use of rich media types in documents, such as animations, audio and video, giving new possibilities to improve information presentation. A distributed environment adds further complexity: documents can contain links to other documents, and the user can interact with components inside them by pausing, stopping or resuming their playback, or by following links to other documents. In this thesis we discuss synchronization issues in hypermedia presentations composed of several continuous and noncontinuous media objects. We define a model for synchronization relationships among media objects, and formally describe a presentation behavior in terms of events which help an automaton to evolve. We have also implemented a visual authoring environment based on the model, and suggested a number of applications in areas related to automatic generation of standard presentations and multimedia information retrieval.