Digital video-on-demand is becoming important, in conjunction with the digitazation of communications and advances in video compression techniques. This paper proposes three new techniques to improve the function and performance of digital video-on-demand systems : multiple readouts of video programs within a few seconds from a disk drive, variable-bit-rate video storage for consistent video quality and efficient multiple readouts, and audio-and-video synchronization that is compatible with a variety of communication networks and video decoding speeds. A new system architecture is also proposed to employ these techniques and video packet transmission. The feasibility of these techniques is experimentally verified. A response time of under one second is achieved from a program request to program initiation on a terminal. In addition, simultaneous access to a video storage server is possible from four terminals if the maximum video bit rate is 2.8 Mbps.