Method and apparatus for generating data, and method and apparatus for restoring data

摘要

A data generation apparatus providing a high security level of trial data is disclosed. Normalization coefficient information not contained in a trial band is replaced with dummy data, and spectral coefficient information is extracted from a code frame. The location where the extracted spectral coefficient was written is filled with a spectral coefficient in a higher frequency range. Trial data to be distributed to users is thus generated. The true values of the normalization coefficient information and the spectral coefficient information are described in additional data. To restore original data from the trial data, the trial data and the additional data that is separately acquired are used. The present invention is applicable to an encoder, a replay apparatus, and a recording apparatus.