PURPOSE: To improve the picture quality and to obtain the high encoding efficiency by changing the system of encoding for each part of the dynamic picture based on the priority while setting the priority for each part encoding the dynamic picture and succeeding the priority according to the moving information obtained at the motion detection.

CONSTITUTION: The generation information amount of a VLC circuit 9 is detected in an intra-frame/inter-frame discriminating device 21 of a microprocessor. The combination pattern between the optimum intra-frame encoding and the inter-frame encoding is decided under the condition that the picture quality is best when the generation information amount is within the constant value. The encoding suitable for the human vision can be performed by deciding the priority in advance. When setting the high priority in the noted part of the picture, the part can be encoded with good picture quality in preference. The combination pattern of the intra-frame encoding and the encoding between backward and forward prediction and both direction prediction for each 1 to N frame can be selected by collecting the information of moving picture sequence to be encoded in advance.