Multimedia-On-Demand (MOD) represents a key demonstrative application for multimedia technology in communication, database, and interface research. This application requires to solve a number of diverse technical problems including the synchronization among time-dependent data such as audio and video.
In this thesis, we first describe the application fields for MOD and their intrinsic characteristics. Based on the characteristics, we propose a multimedia database model which includes an extension of the object-oriented data model, a spatio-temporal model, and a dynamic model. The proposed multimedia database model deals with several media types such as video, audio, image, and text. Moreover, our multimedia data model defines a class for each media and its superclass which has common features of the multimedia data. The spatio-temporal model appropriately composes the temporal information and the spatial information for each media. The temporal information has the responsibility for the synchronization among various media. The spatial information includes the locations of each media data displayed on the screen. The dynamic model represents a user interaction during multimedia presentation as well as VCR functions such as play, fast-forward, reverse, pause, and stop. Finally, we designed and implemented the proposed model in C using the UniSQL/X object-oriented database management system, on a Sun Sparc workstation.
