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US 11,081,121 B2Granted
Signal processing method and device
AssigneeHuawei Technologies Co., Ltd.
InventorsBin Wang, Lei Miao, Zexin Liu
Life of this patent
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Abstract
A signal processing method and device includes obtaining spectral coefficients of a current frame of an audio signal, in which N sub-bands of the current frame comprises at least one of the spectral coefficients. A total energy of M successive sub-bands of the N sub-bands, a total energy of K successive sub-bands of the N sub-bands, and an energy of a first sub-band are obtained to determine whether to modify original envelope values of the M sub-bands. When the original envelope values of the M sub-bands are modified, encoding bits are allocated to each of the N sub-bands according to the modified envelope values of the M sub-bands.
Claims20
An audio signal processing method implemented by an audio signal encoder, the audio signal processing method comprising:
- obtaining an analog audio signal;
- converting the analog audio signal to a digital time domain audio signal;
- transforming the digital time domain audio signal to a frequency domain audio signal, wherein a current frame of the frequency domain audio signal comprises a plurality of spectral coefficients, wherein each of N sub-bands of the current frame comprises at least one of the spectral coefficients, and wherein N is a positive integer greater than 1;
- obtaining a total energy of M successive sub-bands of the N sub-bands;
- determining a largest sub-band energy among the M successive sub-bands;
- obtaining a total energy of K successive sub-bands of the N sub-bands, wherein the M successive sub-bands and the K successive sub-bands are separate, wherein M and K are positive integers, and wherein N=M+K;
- modifying original envelope values of the M successive sub-bands individually to obtain modified envelope values of the M successive sub-bands when the total energy of the M successive sub-bands is greater than the total energy of the K successive sub-bands multiplied by a first factor, when the total energy of the M successive sub-bands is less than the total energy of the K successive sub-bands multiplied by a second factor and when the energy of a first sub-band of the N sub-bands multiplied by a third factor and further multiplied by M is greater than the total energy of the M successive sub-bands, wherein the first factor is less than the second factor, wherein the modified envelope values of the M successive sub-bands is a determining factor for allocating encoding bits to the N sub-bands, and wherein at least one sub-band of the N sub-bands has at least one encoding bit allocated;
- quantizing spectral coefficients of each sub-band that has at least one encoding bit allocated using the at least one encoding bit;
- writing the spectral coefficients of each sub-band that has the at least one encoding bit into a bitstream in response to quantizing the spectral coefficients of each sub-band that has at least one encoding bit;
- and
- sending the bitstream via a network interface.
8 more elements
An audio signal encoder device, comprising:
- a microphone configured to obtain an analog audio signal;
- an analog to digital (A/D) converter coupled to the microphone and configured to convert the analog audio signal to a digital time domain audio signal;
- a digital signal processor coupled to the A/D converter configured to:
- transform the digital time domain audio signal to a frequency domain audio signal, wherein a current frame of the frequency domain audio signal comprises a plurality of spectral coefficients, wherein each of N sub-bands of the current frame comprises at least one of the spectral coefficients, and wherein N is a positive integer greater than 1;
- obtain a total energy of M successive sub-bands of the N sub-bands;
- determine a largest sub-band energy among the M successive sub-bands;
- obtain a total energy of K successive sub-bands of the N sub-bands, wherein the M successive sub-bands and the K successive sub-bands are separate and distinct, wherein M and K are positive integers, and wherein N=M+K;
- modify original envelope values of the M successive sub-bands individually to obtain modified envelope values of the M successive sub-bands when the total energy of the M successive sub-bands is greater than the total energy of the K successive sub-bands multiplied by a first factor, when the total energy of the M successive sub-bands is less than the total energy of the K successive sub-bands multiplied by a second factor, and when the energy of a first sub-band of the N sub-bands multiplied by a third factor and further multiplied by M is greater than the total energy of the M successive sub-bands, wherein the first factor is less than the second factor, wherein the modified envelope values of the M successive sub-bands is a determining factor for allocating encoding bits to the N sub-bands, and wherein at least one sub-band of the N sub-bands has at least one encoding bit allocated;
- quantize spectral coefficients of each sub-band that has at least one encoding bit allocated using the at least one encoding bit;
- and
- write the spectral coefficients of each sub-band that has the at least one encoding bit into a bitstream in response to quantizing the spectral coefficients of each sub-band that has at least one encoding bit;
- and
- a network interface configured to send the bitstream via a network interface.
10 more elements
A non-transitory computer readable storage medium, embodying computer program code, which, when executed by a computer processor, causes the computer processor to be configured to:
- transform a digital time domain audio signal obtained by an analog to digital converter to a frequency domain audio signal, wherein a current frame of the frequency domain audio signal comprises a plurality of spectral coefficients, wherein each of N sub-bands of the current frame comprises at least one of the spectral coefficients, and wherein N is a positive integer greater than 1;
- obtain a total energy of M successive sub-bands of the N sub-bands;
- determine a largest sub-band energy among the M successive sub-bands;
- obtain a total energy of K successive sub-bands of the N sub-bands, wherein the M successive sub-bands and the K successive sub-bands are separate and distinct, wherein M and K are positive integers, and wherein N=M+K;
- modify original envelope values of the M successive sub-bands individually to obtain modified envelope values of the M successive sub-bands when the total energy of the M successive sub-bands is greater than the total energy of the K successive sub-bands multiplied by a first factor, when the total energy of the M successive sub-bands is less than the total energy of the K successive sub-bands multiplied by a second factor, and when the energy of a first sub-band of the N sub-bands multiplied by a third factor and further multiplied by M is greater than the total energy of the M successive sub-bands, wherein the first factor is less than the second factor, wherein the modified envelope values of the M successive sub-bands is a determining factor for allocating encoding bits to the N sub-bands, and wherein at least one sub-band of the N sub-bands has at least one encoding bit allocated;
- quantize spectral coefficients of each sub-band that has at least one encoding bit allocated using the at least one encoding bit;
- write the spectral coefficients of each sub-band that has the at least one encoding bit into a bitstream in response to quantizing the spectral coefficients of each sub-band that has at least one encoding bit;
- and
- send the bitstream via a network interface.
6 more elements
Dependencies are inferred from the claim text.