Patent ID: 6848117

Claim:
A video server apparatus for a video-on-demand system, for providing one of bit streams stored therein in response to a request from a terminal apparatus, the video server apparatus comprising: stream storage means for storing bit streams; keyframe read/transmission bit rate calculating means for calculating a keyframe read bit rate and a keyframe transmission bit rate that are to be used in reading out only keyframes from one of the bit streams and a data length of the keyframes; stream control means for determining, when only the keyframes are read out from the bit stream in accordance with a playback speed designated by the terminal apparatus, a minimum keyframe playback interval that allows complete transmission of the keyframes based on the keyframe read bit rate or the keyframe transmission bit rate, and the keyframe data length, and for determining a keyframe readout interval and a keyframe playback interval that satisfy the designated playback speed based on the minimum keyframe playback interval, a keyframe interval of the bit stream, and the designated playback speed; stream reading means for reading out only the keyframes from the bit stream stored in the stream storage means in accordance with the keyframe readout interval, and for inserting or burying, as additional data, the keyframe playback interval into a stream including the read-out keyframes; and stream transmitting means for transmitting the stream that is output from the stream reading means to the terminal apparatus.