Method and apparatus for changing the timbre and/or pitch of audio signals
AssigneeIVL Technologies Ltd.
InventorsBrian C. Gibson, Christopher M. Jubien, Brian J. Roden
Life of this patent
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Abstract
A method for shifting the timbre and/or pitch of an input signal samples the input signal at a first rate and stores the samples in a memory buffer. A digital signal processor resamples the stored input signal at a rate that differs from the first rate at which the input note is originally sampled and stores the resampled input signal in a second memory buffer. A pitch shifter shifts the pitch of the input signal by periodically scaling the resampled input signal by a window function to create an output signal. The rate at which the resampled data is replicated by the window function determines the pitch of the output signal.
Claims30
A method of creating a timbre shifted output signal from an input signal, comprising the steps of:
- receiving a digital representation of an input signal that has been sampled at a first rate and resampling the digital representation of the input signal at a second rate that differs from the first rate;
- and
- creating a digital representation of the timbre shifted output signal by periodically extracting a segment of the resampled input signal and replicating the extracted segments at a rate equal to a fundamental frequency of the output signal.
A method of creating a timbre, pitch shifted output signal from an input signal, comprising the steps of:
- receiving a digital representation of an input signal that has been sampled at a first rate and creating a digital representation of a pitch shifted output signal by periodically extracting a segment of the input signal and replicating the extracted segments at a rate equal to a fundamental frequency of the pitch shifted output signal;
- and
- creating a digital representation of the timbre shifted output signal by resampling the digital representation of the pitch shifted output signal at a second rate that differs from the first rate.
A method of generating a timbre shifted output vocal signal from an input vocal signal, comprising the steps of:
- receiving a digital representation of the input vocal signal that has been sampled at a first rate and resampling the digital representation of the input vocal signal at a second sampling rate different from the first sampling rate to create a resampled input vocal signal;
- and
- creating a digital representation of the timbre shifted output vocal signal by periodically extracting a segment of the resampled input vocal signal with a window function and replicating the extracted segments at a rate equal to a fundamental frequency of the output vocal signal.
A method of generating a timbre, pitch shifted output vocal signal from an input vocal signal, comprising the steps of:
- receiving a digital representation of the input vocal signal that has been sampled at a first rate and creating a digital representation of the pitch shifted output vocal signal by periodically extracting a segment of the input vocal signal with a window function and replicating the extracted segments at a rate equal to a fundamental frequency of the output vocal signal;
- and
- creating a digital representation of the timbre shifted output vocal signal by resampling the digital representation of the pitch shifted output vocal signal at a second sampling rate that is different from the first sampling rate.
An apparatus for producing a timbre shifted output signal from an input signal, comprising:
- a digital memory;
- a digital signal processor for receiving a digital representation of the input signal that has been sampled at a first rate and for storing the digital representation of the input signal in the digital memory;
- means for resampling the digital representation of the input signal that is stored in the digital memory at a second rate that differs from the first rate, and for storing the resampled input signal in the digital memory;
- and
- a pitch shifter for creating a digital representation of the timbre shifted output signal by periodically extracting a segment of the resampled input signal and replicating the extracted segments at a rate equal to a fundamental frequency of the timbre shifted output signal.
Dependencies are inferred from the claim text.