Moving picture encoding system

Abstract

A moving picture encoding system includes an encoding control unit for setting a target quantiser step size used to encode each of different types of pictures included in a unit group to be encoded, and for performing a control operation to generate and furnish a quantiser step size to an encoding unit so that a ratio among the target quantiser step sizes set for the different types of pictures is a predetermined one. The encoding control unit initially sets the quantiser step size for a macroblock to be encoded first in the current picture currently being encoded to the target quantiser step size set for the picture type of that picture, and, each time the encoding unit encodes each of macroblocks remaining in the current picture, then updates the quantiser step size initially set for the first macroblock so that the average of the quantiser step sizes used during the encoding of all macroblocks in the current picture finally approaches the target quantiser step size set for the picture type of the current picture. Thus the system is able to control the amount of codes generated during the encoding of each of the plurality of pictures in the unit group while keeping the relative picture quality among the plurality of pictures adjacent with respect to time.