A STORAGE AND RETRIEVAL TECHNIQUE FOR SCALABLE DELIVERY OF MPEG-ENCODED VIDEO

Concurrent retrieval of continuous media from a physical storage devic e can be achieved by interleaving data and providing a suitable schedu ling algorithm. Scheduling approaches that exploit gains from statisti cal multiplexing are susceptible to a nonzero probability of frame los s due to the variable-bit-rate characteristic of compressed video. Wit h interframe encoding schemes (such as specified by the MPEG standard) , the losses propagate, resulting in a net loss of frames that exceeds the fraction of lost data In this paper, we describe a mechanism for the storage and retrieval of MPEG-encoded video from a single disk sto rage system. The scheme balances the need for the reliable delivery of MPEG frames with the desire to support the largest number of sessions . Our approach reorganizes the MPEG-encoded video stream based on the relative importance of the frames and maps them to the storage device geometry. The reorganization reduces the impact of frames lost due to missed deadlines and distributes the frame losses over time and among sessions. Simulation results show that the new approach improves perfo rmance when compared to conventional storage and scheduling schemes. ( C) 1995 Academic Press, Inc.