Abstract: An image-coding format converting apparatus comprising an EMPEG2 image decoder 30, a resolution/frame rate converter 31, a motion vector converter 32, and an MPEG4 encoder 33. The EMPEG2 decoder 30 decodes a bit stream of EMPEG2 image codes, generating an image signal. The resolution/frame rate converter 31 converts the image signal. The MPEG4 encoder 33 encodes the output of the resolution/frame rate converter 31, generating a bit stream of MPEG4 image codes. In the resolution/frame rate converter 31, pixels are added or extracted in accordance with the start position of a macro block, thus adjusting the input image signal to one than can easily be encoded to MPEG4 image codes. The motion vector converter 32 generates an MPEG4 motion vector from parameters such as an MPEG2 motion vector. The MPEG4 encoder 33 uses the MPEG4 motion vector to encode the output of the resolution/frame rate converter 31.