Image signal transcoder capable of bit stream transformation suppressing deterioration of picture quality

摘要

An MPEG2 decoder portion decodes an input bit stream and outputs a digital decoded image while extracting coding information and supplying the same to a control portion. An MPEG2 encoder portion re-encodes the digital decoded image output from the MPEG2 decoder portion. Coding information supplied from the control portion is reflected on a coding parameter in re-encoding. Transcoding between the MPEG2 standard and the DV standard can also be executed by arranging a decoder or an encoder corresponding to the DV standard in place of either the MPEG2 decoder portion or the MPEG2 encoder portion.