Picture coding device and method, picture transmitting device and method and recording medium

Abstract

In a quantizing circuit, DCT coefficients output from a DCT circuitare quantized with the quantizing step corresponding to a quantizing index supplied from a quantizing index determining circuit. In the quantizing index determining circuit, the quantizing index is determined on the basis of a first variable corresponding to an occurrence code amount as a data accumulative amount of a bufferand a second variable corresponding to the activity of macroblocks output from an activity detection circuit. In this case, the quantizing index determining circuitadaptively sets a fixing mode for fixing the first variable or a variable mode for making variable the first variable.