摘要 |
Various audio signal watermarking systems are known, which are also applied to digitally encoded audio signals. However, in current audio signal watermarking systems the watermark signal and its watermark payload do not survive very low bit rate audio coding, in particular parametric coding. According to the invention, a watermarked uncompressed audio signal bit-stream is low-bit rate compressed, but the water-marking is removed and the watermark's payload only is transmitted together with the compressed audio signal bit-stream. At decoder side, the received audio signal bit stream is de-compressed and water-marked again using the transmitted watermark payload. Advantageously, it does not matter that the compressed bitstream is not watermarked because the compressed bitstream can be encrypted prior to transmission.
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