Abstract: A system provider has a data storing unit for storing at least one digital picture data block referred to as a minimum playback picture block (GOP: Group of Pictures) in each fixed-length area (for example, picture data for one second is composed of eight GOPs) and a detecting unit for detecting an address in the data storing unit for the picture data to be provided as playback picture data corresponding to a playback request received from a user.

Abstract: A demultiplexer receives an MPEG1 system stream obtained by multiplexing encoded data of video and audio and separates the stream into elementary streams (ES) of video and audio. A packetizer forms packetized elementary streams (PES) of MPEG2. Finally, a multiplexer divides the stream into transport packets each having a prefixed length of 188 bytes and, after that, converts the stream to an MPEG2 transport stream (TS).

Abstract: A multimedia communication system which allows a user at a terminal to efficiently place an order for merchandise with a merchandise provider includes terminals and a multimedia server connected thereto via a public network. The multimedia server includes an information storage unit for storing multimedia information on each merchandise item, a communication control unit for controlling information transmission between terminals and the server via the public network, and a bulletin board service unit for transmitting merchandise items from the information storage unit to the communication control unit in response to a merchandise information look-up request from any of terminals. The multimedia server further has an ordering service unit and a main service unit.