Moving-image signal encoding apparatus with variably selected quantization step size

摘要

A moving-image signal encoding apparatus includes a transmission buffer memory. A first quantization step size for a normal block other than a refreshed block is determined on the basis of an occupied capacity of the buffer memory. A second quantization step size for the refreshed block is determined on the basis of the first quantization step size. A refreshment instruction signal is generated. One of the first quantization step size and the second quantization step size is selected in response to the refreshment instruction signal.