Method and device for spectral expansion for an audio signal
First Claim
1. A system, comprising:
- a processor that performs operations comprising;
generating a mapping matrix based on an analysis of a reference wideband signal and a reference narrowband signal, wherein the mapping matrix is generated without using a linear predictive coefficient (LPC) method, wherein the mapping matrix is generated based on using a dB domain for performing a linear prediction;
generating a resynthesized noise signal by processing a random noise signal with the mapping matrix and an energy envelope analysis of an input narrowband audio signal; and
generating an output audio signal by summing a high-pass filtered version of the resynthesized noise signal with the input narrowband audio signal.
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Abstract
A method and device for automatically increasing the spectral bandwidth of an audio signal including generating a “mapping” (or “prediction”) matrix based on the analysis of a reference wideband signal and a reference narrowband signal, the mapping matrix being a transformation matrix to predict high frequency energy from a low frequency energy envelope, generating an energy envelope analysis of an input narrowband audio signal, generating a resynthesized noise signal by processing a random noise signal with the mapping matrix and the envelope analysis, high-pass filtering the resynthesized noise signal, and summing the high-pass filtered resynthesized noise signal with the original an input narrowband audio signal. Other embodiments are disclosed.
131 Citations
20 Claims
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1. A system, comprising:
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a processor that performs operations comprising; generating a mapping matrix based on an analysis of a reference wideband signal and a reference narrowband signal, wherein the mapping matrix is generated without using a linear predictive coefficient (LPC) method, wherein the mapping matrix is generated based on using a dB domain for performing a linear prediction; generating a resynthesized noise signal by processing a random noise signal with the mapping matrix and an energy envelope analysis of an input narrowband audio signal; and
generating an output audio signal by summing a high-pass filtered version of the resynthesized noise signal with the input narrowband audio signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A method, comprising:
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generating, by utilizing a processor, a mapping matrix based on an analysis of a reference wideband signal and a reference narrowband signal, wherein the mapping matrix is generated without using a linear predictive coefficient (LPC) method, wherein the mapping matrix is generated based on using a dB domain for performing a linear prediction; generating a resynthesized noise signal by processing a random noise signal with the mapping matrix and an energy envelope analysis of an input narrowband audio signal; and
generating an output audio signal by summing a high-pass filtered version of the resynthesized noise signal with the input narrowband audio signal. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18)
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19. A non-transitory computer readable medium containing instructions, the execution of the instructions by a processor of a computer system causing the processor to perform operations comprising:
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generating a mapping matrix based on an analysis of a reference wideband signal and a reference narrowband signal, wherein the mapping matrix is generated based on using a dB domain for performing a linear prediction; generating a resynthesized noise signal by processing a random noise signal with the mapping matrix and an energy envelope analysis of an input narrowband audio signal; and generating an output audio signal by summing a high-pass filtered version of the resynthesized noise signal with the input narrowband audio signal. - View Dependent Claims (20)
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Specification