To reduce memory capacity and memory access to be used for decoding processing by defining encoded data corresponding to one or plural frame images added to an inputted moving image by a moving image encoding means as encoded data not to be referred to when decoding the other frame image.

An input frame encoding means 101 encodes the respective frames of moving images inputted at the frame rate of 10 frames/sec as an I frame in an MPEG system. A moving image encoding means 103 generate the MPEG encoded data finally containing data corresponding to the image of 30 frames per second by successively alternately combining two B frame encoded data 102 to one encoded data as the I frame outputted from the input frame encoding means 101. Since only the reproduced image encoded as the I frame is referred to at the time of reproducing the other image, it is not necessary to store the image of B frame in a memory.