2PSM: an efficient framework for searching video information in a limited-bandwidth environment

We present a novel technique, called 2-Phase Service Model, for streaming v ideos to home users in a limited-bandwidth environment. This scheme first d elivers some number of non-adjacent data fragments to the client in Phase 1 . The missing fragments are then transmitted in Phase 2 as the client is pl aying back the video. This approach offers many benefits. The isochronous b andwidth required for Phase 2 can be controlled within the capability of th e transport medium. The data fragments received during Phase 1 can be used to provide an excellent preview of the video. They can also be used to faci litate VCR-style operations such as fast-forward and fast-reverse. Systems designed based on this method are less expensive because the fast-forward a nd fast-reverse versions of the video files an no longer needed. Eliminatin g these files also improves system performance because mapping between the regular files and their fast-forward and fast-reverse versions is no longer part of the VCR operations. Furthermore, since each client machine handles its own VCR-style interaction, this technique is very scalable. We provide simulation results to show that 2-Phase Service Model is able to handle VC R functions efficiently. We also implement a video player called FRVplayer. With this prototype, we are able to judge that the visual quality of the p reviews and VCR-style operations is excellent. These features are essential to many important applications. We discuss the application of FRVplayer in the design of a video management system, called VideoCenter. This system i s intended for Internet applications such as digital video libraries.