User-interaction supported data-retrieving engine for distributed multimedia presentations

Distributed multimedia presentation enables users to view a multimedia presentation in the distributed manner, in which the objects of the presentation are located in remote sites. User-interaction provi des the viewer with convenient viewing styles like fast forward and fast backward for a presentation, but it also introduces complexity to the data-retrieving engine. A smart data-retrieving engine that supports user interactions for the SMIL-based multime dia presentation is proposed in the paper. The SMIL script of the presentation is first converted to Real -Time Synchronization Model (RTSM) in order to provide a systematic view of the synchronization relationship. The algorithm for determining the proper objects to be retrieved as well as the pre-fetch time of the object under user actions is proposed for the data-retrieving engine.