Design and analysis of a scalable watermarking scheme for the scalable audio coder

In this paper, we present a scalable approach to lossless watermarking for audio signals. The proposed watermarking framework is built on a recently standardized two-layer scalable audio coder advanced audio zip (AAZ) [1]. By embedding watermarks in both the core layer and enhancement layer bitstreams. in a special way, the watermark distortion in either layer is compensated by the watermark in the opposite layer. The proposed spread-spectrum-based solution overcomes both the problem of introducing noninvertible distortions in lossy watermark approaches and the problem of nonadaptive embedding in lossless watermarking approaches. Theoretic analysis and experiment results further confirm the validity of the proposed framework in terms of payload, robustness, data expansion property, and perceptual quality.