Video-on-demand system using optical mass storage system

Digital video-on-demand systems based on high-speed digital networks and video compression techniques have been proposed recently. One serious problem for these systems is achieving mass storage with quick access. In this paper we propose a video storage hierarchy of magnetic disks and an optical mass storage system (MSS). To solve the problems that occur when optical mass storage systems are used in video-on-demand services, we have proposed techniques such as quick-start and linking of playback, multiple readout, and visual search in a storage hierarchy with magnetic disks. A trial system has verified the feasibility of these new techniques. The average response time for `quick-start and linking' is less than one second. Another technical problem is the implementation of visual search functions such as fast forward and fast reverse together with multiple access. Average switch-over time between visual search functions is also less than one second. In this trial system, which uses the JPEG encoding algorithm, we proposed and verified a new method for synchronizing fixed bit-rate audio and variable bit-rate video.