Wadia Digital Corporation

Other

Intel Corporation

Robert W Moses

Donald W Moses

Charles H Hustig

James M Kresse

Robert S Bradford

Jeffrey L Ward

Wayne P Olson

Raymond S Miller

Norman Durkee

The foregoing problems are solved and a technical advance is achieved by a computer-implemented system for providing a digital watermark in an audio signal. In a preferred embodiment, a audio file, such as a .WAV file, representing an audio signal to be watermarked is preprocessed using an algorithm of the present invention herein referred to as the &ldquo;PAWS algorithm&rdquo; to determine and log the location and number of opportunities that exist for inserting a watermark into the audio signal such that it will be masked by the audio signal. The user can adjust certain parameters of the PAWS algorithm before the audio file is processed. A/B/X testing between the original and watermarked files is also supported to allow the user to undo or re-encode the watermark, if desired.

System for providing a digital watermark in an audio signal

A signal processing system comprises inputs for an analog audio signal and a digital data signal. The digital data signal is modulated to an analog data signal in an inaudible frequency band. Filters are used to ensure that the audio signal is restricted to audible frequencies and that the analog data signal is restricted to inaudible frequencies. The two analog signals are then combined into a composite analog signal. The composite signal is stored on a medium such as a compact disc. Filters are used to extract and separate the two analog signals from the composite signal stored on the medium. The analog data signal is demodulated to retrieve the original digital data signal.

System for carrying transparent digital data within an audio signal

A direct power output digital to analog conversion of digital audio signals operates to directly convert digital audio signals into an analog power audio output signal capable of driving a speaker, such that there is no need for further amplification or modification of the audio output signal after the direct power output digital to analog conversion of the digital audio signals. The direct power output digital to analog conversion incorporates a digital-to-analog converter within the same feedback circuit as a current-to-voltage power amplifier by using a single resistive feedback network to supply the feedback signal from the output terminal of the current-to-voltage power amplifier to the summing junction of the same current-to-voltage power amplifier.

Direct power output digital to analog conversion of digital audio signals

A method and system is provided for a digital audio system to reconstruct a digital audio signal using time domain interpolation and direct power digital-to-analog conversion. A signal processor performs the time domain interpolation on an original digital audio signal to allow for the proper recreation of the original audio signal and a direct power output digital-to-analog converter generates an analog power audio output signal from the interpolated digital audio signal that can directly drive a speaker to produce the sound waves represented by the audio output signal. The signal processor and direct power output digital-to-analog converter allow a digital audio system to more precisely reconstruct an analog power output audio signal from a digital audio signal such that there is no need for further amplification of the audio output signal and such that there will be no perceptible difference between the reconstructed digital signal and the original analog signal.

Method and system for time domain interpolation of digital audio signals

An apparatus for the domain interpolation of digital audio signals includes a signal processor apparatus to reconstruct the digital audio signal. The signal processor apparatus includes a receiver for receiving a digital audio signal, a decoder for demodulating the signal, a central processing unit for performing a time domain interpolation on the decoded signal to produce an interpolated data signal having an increased sampling rate over the digital audio signal, and a digital-to-analog converter for converting the interpolated data signal into an analog output signal that may be transmitted to an amplifier for output through a speaker. The signal processor apparatus achieves an oversampling rate and digital to analog conversion that will allow a digital audio system to more precisely reconstruct an analog audio signal from a digital audio signal such that there will be no perceptible difference between the reconstructed digital signal and the original analog signal.

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Seattle, WA, United States of America

Robert W Moses