Synchronization of distributed multimedia systems with user interactions

Abstract

Without user interactions, multimedia presentations are just fancy slide shows with sound and video supports. User interactions by themselves do not change the temporal relationships among multimedia objects, such as texts, graphics, images, audio, and video, but affect the play-back schedules. In this paper, we propose a synchronization mechanism to guarantee the quality of multimedia presentation with user interactions. In our protocol, each presentation site requests media transmission from the required media servers at certain time intervals prior to the play-back deadlines, where these time intervals are the response times to cover possible experienced end-to-end delays and packet losses, and waits for an initial setup time to ensure intermedia synchronization before starting the presentation. Users may interact with the presentation. This synchronization mechanism solves the problems incurred by user interactions by determining the new presentation scenario produced by the interactive operation, calculating the corresponding setup time, and then rendering the new playback and retrieval schedules.