Coding of Video Signals at 50 Kb/s using Motion Compensation Techniques

This paper describes the coding algorithm and the simulation of a multimode movement compensated interframe video coder operating at 50 kb/s for possible use in the proposed National Command Authority Teleconferencing System (NCATS)[1]. The system provides multisite, multimedia conferencing. The coding algorithm combines several data rate reduction techniques in what is termed as a multimode interframe video coder. A key element to achieving the required bit rate reduction while maintaining acceptable picture quality is the utilization of motion compensation techniques. In this paper issues related to displacement estimation and motion compensation techniques in the low bit rate coding environment are discussed. Simulation results using several color video sequences with varying amounts of motion are presented. These results show that acceptable picture quality is obtained at 50 kb/s.