Architecture of MPEG-2 digital set-top-box for CATV VOD system

We describe an MPEG-2 compliant VOD (video on demand) terminal (e.g. set-top-box) developed for field trial purposes. The hardware architecture of the set-top-box is discussed with emphasis on the graphics system which integrates the MPEG-2 format video, computer graphics and NTSC analog format video. A key point in the implementation of this architecture is the development of a clock rate conversion circuit. The set-top-box contains a one-chip MPEG-2 decoder.