DEVICE AND METHOD FOR PICTURE PROCESSING AND PRESENTATION MEDIUM

PROBLEM TO BE SOLVED: To prevent quality deterioration of a decoded picture by change of a quantization step of a macro block caused by rate control. SOLUTION: A quantizer 2 quantizes picture data by a specified quantization step. A buffer 4 supplies a rate controller 11 with the first parameter by one screen for having the generated code amount of data that encode a picture coincide with the target code amount. A parameter detector 10 supplies the rate controller 11 with the second parameter corresponding to an activity of a macro block. An encoder control subsystem 12 supplies the rate controller with the third parameter corresponding to the target code amount. The rate controller 11 controls a quantized step based on the supplied first to third parameters.