Watermarking for musical pieces indexing used in automatic cue sheet generation systems
We propose a fast and robust watermarking scheme for digital audio signals that allows automatic identification of musical pieces transmitted in TV broadcast programs. Usually the watermark is used as a way for hiding information on digital media. The watermarked information may allow copyright protection or user identification and media indexing. In our application the watermark must be, obviously, imperceptible to the users to maintain the quality of the source, should be robust to standard TV and radio editing and its processing has to require a very low complexity. This last item is essential to allow a software real-time implementation of the insertion and detection of watermark using only a minimum amount of the computation power of a modern PC. In the proposed algorithm we divide the audio signal in frames, on each frame a masking function is computed based on the human auditory system (HAS), and the watermark is embedded using a spread spectrum technique. Simulation results obtained on a long set of subjective tests prove the quality and the robustness of the proposed approach.