High frequency regeneration of an audio signal with temporal shaping
First Claim
1. A method for generating a reconstructed audio signal having a baseband portion and a highband portion, the method comprising:
- extracting temporal envelope information, wherein the temporal envelope information includes coefficients representing a reconstruction filter;
extracting spectral components of the baseband portion, wherein the spectral components of the baseband portion do not include spectral components of the highband portion;
obtaining a decoded baseband audio signal, wherein the obtaining includes filtering in a frequency domain at least some of the spectral components of the baseband portion with the reconstruction filter using the temporal envelope information to shape a temporal envelope of the baseband portion;
extracting a noise parameter and an estimated spectral envelope of the highband portion;
obtaining a plurality of subband signals by filtering the decoded baseband audio signal;
generating a high-frequency reconstructed signal by copying a number of consecutive subband signals of the plurality of subband signals;
obtaining an envelope adjusted high-frequency signal by adjusting, based on the estimated spectral envelope of the highband portion, a spectral envelope of the high-frequency reconstructed signal;
generating a noise component based on the noise parameter, wherein the noise parameter indicates a level of noise contained in the highband portion;
obtaining a combined high-frequency signal by adding the noise component to the envelope adjusted high-frequency signal; and
obtaining a time-domain reconstructed audio signal by combining the decoded baseband audio signal and the combined high-frequency signal;
wherein the method is implemented by an audio decoding device comprising one or more hardware elements.
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Abstract
A method for generating a reconstructed audio signal having a baseband portion and a highband portion is disclosed. The method includes extracting temporal envelope information and spectral components of the baseband portion. The method further includes obtaining a decoded baseband audio signal. The obtaining includes filtering in a frequency domain at least some of the spectral components of the baseband portion with the reconstruction filter using the temporal envelope information to shape a temporal envelope of the baseband portion. The method also includes extracting a noise parameter and an estimated spectral envelope of the highband portion and obtaining a plurality of subband signals by filtering the decoded baseband audio signal. The method further includes generating a high-frequency reconstructed signal by copying a number of consecutive subband signals of the plurality of subband signals and obtaining an envelope adjusted high-frequency signal by adjusting, based on the estimated spectral envelope of the highband portion, a spectral envelope of the high-frequency reconstructed signal.
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Citations
11 Claims
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1. A method for generating a reconstructed audio signal having a baseband portion and a highband portion, the method comprising:
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extracting temporal envelope information, wherein the temporal envelope information includes coefficients representing a reconstruction filter; extracting spectral components of the baseband portion, wherein the spectral components of the baseband portion do not include spectral components of the highband portion; obtaining a decoded baseband audio signal, wherein the obtaining includes filtering in a frequency domain at least some of the spectral components of the baseband portion with the reconstruction filter using the temporal envelope information to shape a temporal envelope of the baseband portion; extracting a noise parameter and an estimated spectral envelope of the highband portion; obtaining a plurality of subband signals by filtering the decoded baseband audio signal; generating a high-frequency reconstructed signal by copying a number of consecutive subband signals of the plurality of subband signals; obtaining an envelope adjusted high-frequency signal by adjusting, based on the estimated spectral envelope of the highband portion, a spectral envelope of the high-frequency reconstructed signal; generating a noise component based on the noise parameter, wherein the noise parameter indicates a level of noise contained in the highband portion; obtaining a combined high-frequency signal by adding the noise component to the envelope adjusted high-frequency signal; and obtaining a time-domain reconstructed audio signal by combining the decoded baseband audio signal and the combined high-frequency signal; wherein the method is implemented by an audio decoding device comprising one or more hardware elements. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. An audio decoder generating a reconstructed audio signal having a baseband portion and a highband portion, the audio decoder comprising:
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an extractor for obtaining temporal envelope information, wherein the temporal envelope information includes coefficients representing a reconstruction filter; an extractor for obtaining spectral components of the baseband portion, wherein the spectral components of the baseband portion do not include spectral components of the highband portion; a decoder for obtaining a decoded baseband audio signal, wherein the decoder includes a reconstruction filter for processing at least some of the spectral components of the baseband portion using the temporal envelope information to shape a temporal envelope of the baseband portion; an extractor for obtaining a noise parameter and an estimated spectral envelope of the highband portion; a filter for obtaining a plurality of subband signals from the decoded baseband audio signal; a generator for creating a high-frequency reconstructed signal by copying a number of consecutive subband signals of the plurality of subband signals; an envelope adjuster for obtaining an envelope adjusted high-frequency signal by adjusting, based on the estimated spectral envelope of the highband portion, a spectral envelope of the high-frequency reconstructed signal; a noise generator for generating a noise component based on the noise parameter, wherein the noise parameter indicates a level of noise contained in the highband portion; a combiner for obtaining a combined high-frequency signal by adding the noise component to the envelope adjusted high-frequency signal; and a synthesizer for obtaining a time-domain reconstructed audio signal by combining the decoded baseband audio signal and the combined high-frequency signal; wherein the audio decoder comprises one or more hardware elements.
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Specification