Development of Columbia's video on demand testbed

This paper describes our progress in developing an advanced video-on-demand (VOD) testbed, which will accommodate various multimedia research and applications such as Electronic News on Demand, Columbia's Video Course Network, and Digital Libraries. Two different prototypes have been completed. The first generation of the testbed was based on a constant-bit-rate (CBR) video server utilizing Ethernet delivery. Contents were encoded and stored as MPEG-2 audio/video elementary streams. Software encoders/decoders were used in content generation and playback. The second generation of the testbed was enhanced with the capability of transmitting true MPEG-2 transport streams over the campus ATM network as well as the wide-area NYNET ATM network. A real-time video pump and a distributed application control protocol (MPEG-2's DSM-CC) have been incorporated. Hardware decoders and set-tops are being incorporated to test wide-area video interoperability. Our VOD testbed also provides an advanced platform for implementing proof-of-concept prototypes of related research. Our current research focus covers video transmission with heterogeneous quality-of-service (QoS) provision, video storage architecture design, content-based video indexing and browsing, multi-resolution (MR) video coding, efficient manipulation of compressed video, and advanced user interfaces. An important aim is to enhance interoperability. Accommodation of practical multimedia applications and interoperability testing with external VOD systems are currently being undertaken.