Patent ID: 6987808

Claim:
A transcoding method of converting first coded data, which is obtained from a plurality of pictures of a moving-picture by performing discrete cosine transform (DCT) and performing a coding process including quantization, into second coded data, the transcoding method comprising: an inverse-quantization step of performing inverse-quantization, corresponding to the quantization, on the first coded data respectively corresponding to macroblocks of each of the plurality of pictures; an obtaining step of obtaining DC-component difference values of DCT coefficients of each of the macroblocks of an intra-frame coded intra picture included in the first coded data; and a generating step of performing requantization on the inverse-quantized data respectively corresponding to the macroblocks by using a requantization scale corresponding to a corresponding one of the obtained DC-component difference values respectively corresponding to the macroblocks of the intra picture to generate the second coded data.