Lightweight video service for multi-media digital libraries

In this paper we present the design, architecture, implementation and performance of a digital library of video data. Our goal is to provide a lightweight video service for multimedia digital libraries built upon an ATM infrastructure, providing nonlinear editing and viewing of video. To accomplish this objective we have used a low overhead, high performance persistent object manager to manage the underlying video data. To test these ideas, we used the lightweight persistent object manager PTool, developed by the Laboratory for Advanced Computing at the University of Illinois at Chicago, to create persistent object stores of video data on a cluster of Unix workstations connected with an ATM switch. To improve performance, we striped the video data across the cluster. We verified that we were able to manage gigabytes of video data without performance degradation and that striping improved performance linearly up to the bandwidth of the equipment. We also compared the performance of ATM networked and ethernet networked clusters. Finally, we mention that viewing the video data as a persistent collection of objects (i.e. each frame of video as an object) provides attribute based retrieval of data, and hence allows for very simple editing, querying and retrieval of video data by attribute. It allows for the use of object associations to combine video, audio, text, etc.