Patent ID: 7283967

Claim:
An encoding device that encodes an inputted audio signal, the encoding device comprising: a first encoding unit operable to encode spectral data in a lower frequency band out of spectral data which is obtained by transforming the audio signal inputted for a fixed time length and divided into a plurality of groups, the spectral data in the lower frequency band being represented by four parameters, the four parameters including (1) a normalizing factor for normalizing the spectral data in each of the groups of the lower frequency band, (2) a quantized value obtained by quantizing the spectral data in each of the groups of the lower frequency band using the normalizing factor, (3) a positive or negative sign indicating a phase of the spectral data in each of the groups of the lower frequency band, and (4) a position of the spectral data in each of the groups of the lower frequency band in a frequency domain; a sub information generating unit operable to generate sub information including: (1) specification information for specifying a spectrum in the lower frequency band in which a difference is minimum between (a) a distance in the frequency domain, for each of the groups of the higher frequency band, from a boundary of the group to a peak of a spectrum in the group and (b) a distance in the frequency domain, for each of the groups of the lower frequency band, from a boundary of the group to a peak of a spectrum in the group, as information for specifying spectral data in the lower frequency band which is approximate to the spectral data in each of the groups of the higher frequency band; and (2) correction information indicating a characteristic of the spectral data in the higher frequency band which is represented by three or less of the four parameters, as information for correcting the specified spectral data in the lower frequency band; a second encoding unit operable to encode the generated sub information; and an outputting unit operable to output the data encoded by the first encoding unit and the data encoded by the second encoding unit.