Data processing method and device for processing speech signal or audio signal

A time-domain to frequency-domain signal processing method for processing a raw audio signal performed by an audio signal processing device comprising a processor, comprising:

• obtaining a time domain signal corresponding to the raw audio signal;
• obtaining a pre-processed signal by pre-processing the time domain signal;
• pre-rotating the pre-processed signal by using a rotate factor (a·WNn+0.5) to generate a pre-rotated signal;
• performing a Fast Fourier Transform (FFT) of N/4 point on the pre-rotated signal to generate a FFT transformed signal;
• post-rotating the FFT transformed signal using a rotate factor (b·WNk+0.5), so as to obtain a frequency domain signal;
• writing a processed audio signal based on the frequency domain signal into a bitstream for transmitting or storing;
• wherein, before the obtaining the frequency domain signal, the method further comprises performing fixed rotate compensation by using a fixed rotate compensation factor;
• (a) and (b) are constants, the N is the length of the time domain signal, and
• W
• N
• =
• ⅇ
• -
• j
• ⁢
• ⁢
• 2
• ⁢
• π
• N
• .

A frequency-domain to time-domain signal processing method for processing a raw audio signal performed by an audio signal processing device including a processor, comprising:

• obtaining a frequency domain signal corresponding to the raw audio signal;
• obtaining a twiddled signal by twiddling the frequency domain signal;
• pre-rotating the twiddled signal by using a rotate factor (c·WNk+0.5) to generate a pre-rotated signal;
• performing a Fast Fourier Transform (FFT) of N/4 point on the pre-rotated signal to generate a FFT transformed signal;
• post-rotating the FFT transformed signal using a rotate factor (d·WNn+0.5) to generate a post-rotated signal;
• post-processing the post-rotated signal, so as to obtain a time domain signal;
• and
• obtaining a processed audio audio signal based on the post-rotated signal;
• wherein, before obtaining the time domain signal, the method further comprises performing fixed rotate compensation by using a fixed rotate compensation factor;
• (c) and (d) are constants, the N is twice the length of the frequency domain signal, and
• W
• N
• =
• ⅇ
• -
• j
• ⁢
• ⁢
• 2
• ⁢
• π
• N
• .

A signal processing device for processing a raw audio signal to transform the raw audio signal from time domain to frequency or from frequency domain to time domain and including a processor, comprising:

• a unit configured to obtain an input signal corresponding to the raw audio signal;
• a twiddle unit, configured to twiddle the input signal, so as to obtain a twiddled signal;
• a pre-rotate unit, configured to pre-rotate the twiddled signal by using a first symmetric rotate factor to generate a pre-rotated signal, wherein the first symmetric rotate factor is (a·W4L2p+1), wherein p=0, . . . , L/2−1, and (a) is a constant;
• a transform unit, configured to perform a Fast Fourier Transform (FFT) of L/2 point on the pre-rotated signal to generate a FFT transformed signal, wherein L is the length of the input signal;
• a post-rotate unit, configured to post-rotate the FFT transformed signal using a second symmetric rotate factor to generate a post-rotated signal, wherein the second symmetric rotate factor is (b·W42q+1), wherein q=0, . . . , L/2−1, and wherein (b) is a constant;
• and
• a unit configured to write a processed audio signal based on the post-rotated signal into a bitstream for transmitting or storing.

A time-domain to frequency-domain signal processing device for processing a raw audio signal and including a processor, comprising:

• a unit configured to obtain a time domain signal corresponding to the raw audio signal;
• a pre-processing unit, configured to pre-process the time domain signal, so as to obtain a pre-processed signal;
• a pre-rotate unit, configured to pre-rotate the pre-processed signal by using a rotate factor (a·Nn+0.5) to generate a pre-rotated signal;
• a transform unit, configured to perform a Fast Fourier Transform (FFT) of N/4 point on the pre-rotated signal to generate a FFT transformed signal;
• a post-rotate unit, configured to post-rotate the FFT transformed signal using a rotate factor (b·WNk+0.5), so as to obtain a frequency domain signal;
• a unit configured to write a processed audio signal based on the frequency domain signal into a bitstream for transmitting or storing;
• wherein, the device further comprises:
• a fixed compensation unit, configured to perform fixed rotate compensation by using a fixed rotate compensation factor;
• the (a) and (b) are constants, the N is the length of the time domain signal, and
• W
• N
• =
• ⅇ
• -
• j
• ⁢
• ⁢
• 2
• ⁢
• π
• N
• .

A frequency-domain to time-domain signal processing device for processing a raw audio signal and including a processor, comprising:

• a unit configured to obtain a frequency domain signal corresponding to the raw audio signal;
• a twiddle unit, configured to twiddle the frequency domain signal, so as to obtain a twiddled signal;
• a pre-rotate unit, configured to pre-rotate the twiddled signal by using a rotate factor (c·WNk+0.5) to generate a pre-rotated signal;
• a transform unit, configured to perform a Fast Fourier Transform (FFT) of N/4 point on the pre-rotated signal to generate a FFT transformed signal;
• a post-rotate unit, configured to post-rotate the FFT transformed signal using a rotate factor (d·WNn+0.5);
• a unit configured to obtain a processed audio signal based on the post-rotated signal;
• wherein, the device further comprises:
• a fixed compensation unit, configured to perform fixed rotate compensation by using a fixed rotate compensation factor;
• the (c) and (d) are constants, the N is twice the length of the frequency domain signal, and
• W
• N
• =
• ⅇ
• -
• j
• ⁢
• 2
• ⁢
• ⁢
• π
• N
• .

A time-domain to frequency-domain audio signal processing method, with the audio signal processing being performed by an audio signal processing device including a processor, comprising:

• obtaining a time domain signal corresponding to a raw audio signal;
• applying at least one twiddle factor to the time domain signal to obtain a twiddled signal;
• pre-rotating, by using a symmetric rotation factor (a·W4L2p+1), the twiddled signal to obtain a pre-rotated signal, wherein p=0, . . . , L/2−1, and (a) is a constant;
• performing a Fast Fourier Transform (FFT) of L/2 points on the pre-rotated signal to obtain a FFT transformed signal;
• performing a fixed rotate compensation to the FFT transformed signal by multiplying the FFT transformed signal with a fixed rotate compensation factor;
• post-rotating the FFT transformed signal using a symmetric rotate factor (b·W4L2q+1) to obtain a post-rotated signal, wherein q=0, . . . , L/2−1, and (b) is a constant;
• writing a processed audio signal based on the post-rotated signal into a bitstream for transmitting or storing.

A time-domain to frequency-domain audio signal processing apparatus, comprising:

• a processor;
• and
• memory coupled to the processor and including non-transitory computer-readable instructions that, when executed by the processor:
• obtain a time domain signal corresponding to a raw audio signal;
• apply twiddle factors to the time domain signal to obtain a twiddled signal;
• pre-rotate, by using a symmetric rotation factor (a·W4L2p+1), the twiddled signal to obtain a pre-rotated signal, wherein p=0, . . . , L/2−1, and (a) is a constant;
• perform a Fast Fourier Transform (FFT) of L/2 points on the pre-rotated signal to obtain a FFT transformed signal;
• perform a fixed rotate compensation to the FFT transformed signal by multiplying the FFT transformed signal with a fixed rotate compensation factor;
• post-rotate the FFT transformed signal using a symmetric rotate factor (b·W4L2q+1) to obtain a post-rotated signal, wherein q=0, . . . , L/2−1, and (b) is a constant;
• write a processed audio signal based on the post-rotated signal into a bitstream for transmitting or storing.