METHOD AND SYSTEM OF ELECTRONIC WATERMARK OF COMPRESSED AUDIO DATA

摘要

PROBLEM TO BE SOLVED: To provide a method and a system for directly operating information in compressed digital audio data. SOLUTION: A system which embeds additional information in compressed audio data has (1) a means for restoring a MDCT(modified Discrete Cosine Transform) coefficient from the compressed audio data, (2) a means which finds frequency components of the audio data by using the restored MDCT coefficient, (3) a means for embedding the additional information in the found frequency components in a frequency space, and (5) a means for generating compressed audio data from the MDCT coefficient embedded in the additional information.