Audio processing for voice encoding and decoding using spectral shaper model
The present disclosure relates to an audio encoding and decoding (codec) system for voice encoding/decoding using a spectral shaper model. In an embodiment, a method of audio signal decoding comprises: receiving a bit stream associated with an audio signal, the bit stream including encoded transform coefficients, spectral envelope data and one or more parameters of a spectral shaper model, the spectral shaper model indicative of a fundamental frequency of a multi-sinusoidal signal model, where the fundamental frequency corresponds to a time domain delay; decoding the encoded transform coefficients; adjusting the decoded transform coefficients using the spectral envelope data and the spectral shaper model; reconstructing transform coefficients of the audio signal using the adjusted, decoded transform coefficients; and transforming the reconstructed transform coefficients into a time domain audio signal.
1. A method of audio signal decoding, comprising:
receiving a bit stream associated with an audio signal, the bit stream including encoded transform coefficients, spectral envelope data and one or more parameters of a spectral shaper, the spectral shaper indicative of a fundamental frequency of a multi-sinusoidal signal model, where the fundamental frequency corresponds to a time domain delay;
decoding the encoded transform coefficients;
adjusting, with a subband predictor, the decoded transform coefficients using the spectral envelope data and the spectral shaper;
reconstructing transform coefficients of the audio signal using the adjusted, decoded transform coefficients; and
transforming the reconstructed transform coefficients into a time domain audio signal.
2. The method of claim 1 , further comprising:
dequantizing the transform coefficients with a quantizer selected from a plurality of quantizers.
3. The method of claim 1 , wherein adjusting the transform coefficients includes unflattening the transform coefficients.
4. The method of claim 1 , wherein the one or more parameters include a gain parameter and a lag parameter in stride units.
5. A system comprising:
one or more processors; and
a non-transitory computer-readable medium storing instructions that, when executed by the one or more processors, causes the one or more processors to perform operations comprising:
receiving a bit stream associated with an audio signal, the bit stream including encoded transform coefficients, spectral envelope data and one or more parameters of a spectral shaper, the spectral shaper indicative of a fundamental frequency of a multi-sinusoidal signal model, where the fundamental frequency corresponds to a time domain delay;
decoding the encoded transform coefficients;
adjusting, with a subband predictor, the decoded transform coefficients using the spectral envelope data and the spectral shaper;
reconstructing transform coefficients of the audio signal using the adjusted, decoded transform coefficients; and
transforming the reconstructed transform coefficients into a time domain audio signal.
6. The system of claim 5 , the operations further comprising:
dequantizing the transform coefficients with a quantizer selected from a plurality of quantizers.
7. The system of claim 5 , wherein adjusting the transform coefficients includes unflattening the transform coefficients.
8. The system of claim 5 , wherein the one or more parameters include a gain parameter and a lag parameter in stride units.
9. A non-transitory computer-readable medium storing instructions that, when executed by one or more processors, causes the one or more processors to perform operations comprising:
receiving a bit stream associated with an audio signal, the bit stream including encoded transform coefficients, spectral envelope data and one or more parameters of a spectral shaper, the spectral shaper indicative of a fundamental frequency of a multi-sinusoidal signal model, where the fundamental frequency corresponds to a time domain delay;
decoding the encoded transform coefficients;
adjusting, with a subband predictor, the decoded transform coefficients using the spectral envelope data and the spectral shaper;
reconstructing transform coefficients of the audio signal using the adjusted, decoded transform coefficients; and
transforming the reconstructed transform coefficients into a time domain audio signal.
10. The non-transitory computer-readable medium of claim 9 , the operations further comprising:
dequantizing the transform coefficients with a quantizer selected from a plurality of quantizers.
11. The non-transitory computer-readable medium of claim 9 , wherein adjusting the transform coefficients includes unflattening the transform coefficients.
12. The non-transitory computer-readable medium of claim 9 , wherein the one or more parameters include a gain parameter and a lag parameter in stride units.