METHODS AND APPARATUS FOR EMBEDDING CODES IN COMPRESSED AUDIO DATA STREAMS

摘要

Example methods disclosed herein to embed a watermark in a compressed audio stream include 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. Such disclosed example methods also include 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. Such disclosed example methods further include replacing the first scale factor with the second scale factor and the first set of mantissas with the second set of mantissas to embed the watermark in the compressed audio stream.

主权项

1. A method to embed a watermark in a compressed audio stream, the method comprising:
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.