METHODS AND APPARATUS FOR EMBEDDING CODES IN COMPRESSED AUDIO DATA STREAMS

摘要

A method to embed a watermark in a compressed audio stream is disclosed. The method may comprise: accessing a first scale factor and a first set of mantissas for a first set of transform coefficients included in the compressed audio stream, the first set of transform coefficients corresponding to a first band of a compression standard; quantizing a second set of transform coefficients based on a second scale factor corresponding to the first scale factor reduced by a unit of resolution to determine a second set of mantissas, the second set of transform coefficients corresponding to the first band of the compression standard and including the watermark; and replacing the first scale factor with the second scale factor and the first set of mantissas with the second set of mantissas to modify the first set of transform coefficients to embed the watermark in the compressed audio stream.