Patent ID: 8081757

Claim:
A method for watermarking data embedded in a non-transitory audio signal by using modifications of the phase values of the amplitude-phase vector s of a current time-to-frequency domain converted block of said audio signal, said method comprising the steps: controlling by the value of a current bit of said watermark data the selection or the generation of a corresponding pseudo-random reference data sequence, of which reference data sequence the phase values vector in the frequency domain is denoted p; modifying, according to said corresponding reference data sequence, phase values of said current time-to-frequency domain converted audio signal block by a phase values vector d, d =p−phase(s) , wherein on one hand each bin of vector d is incremented by 2π if it is lower than −π and decremented by 2π if it is greater than π and on the other hand each bin of vector d is further limited to a corresponding value in a phase values vector m, in which vector m a pre-determined maximum amount for said phase value modification is determined by psycho-acoustic related calculations; frequency-to-time domain converting the modified version of said current block of said audio signal; outputting the corresponding section of the watermarked audio signal.