Speech/audio signal processing method and apparatus

Patent metadata

Field	Value
Publication number	US-9691396-B2
Application number	US-201414470559-A
Country	US
Kind code	B2
Filing date	Aug 27, 2014
Priority date	Mar 1, 2012
Publication date	Jun 27, 2017
Grant date	Jun 27, 2017

Abstract

The present invention discloses a speech/audio signal processing method and apparatus. In an embodiment, the speech/audio signal processing method includes: when a speech/audio signal switches bandwidth, obtaining an initial high frequency signal corresponding to a current frame of speech/audio signal; obtaining a time-domain global gain parameter of the initial high frequency signal; performing weighting processing on an energy ratio and the time-domain global gain parameter, and using an obtained weighted value as a predicted global gain parameter, where the energy ratio is a ratio between energy of a historical frame of high frequency time-domain signal and energy of a current frame of initial high frequency signal; correcting the initial high frequency signal by using the predicted global gain parameter, to obtain a corrected high frequency time-domain signal; and synthesizing a current frame of narrow frequency time-domain signal and the corrected high frequency time-domain signal and outputting the synthesized signal.

First claim

What is claimed is:

1. A speech/audio signal processing method, comprising:
when a speech/audio signal switches from a wide frequency signal to a narrow frequency signal, obtaining, by a decoder, an initial high frequency signal corresponding to the narrow frequency signal;
obtaining, by the decoder, a time-domain global gain parameter of the initial high frequency signal according to a spectrum tilt parameter of the current frame of speech/audio signal and a correlation between a narrow frequency signal of the current frame and a narrow frequency signal of a historical frame;
performing, by the decoder, weighting processing on an energy ratio and the time-domain global gain parameter, and using an obtained weighted value as a predicted global gain parameter, wherein the energy ratio is a ratio between energy of a historical frame of high frequency time-domain signal and energy of a current frame of initial high frequency signal;
correcting, by the decoder, the initial high frequency signal by using the predicted global gain parameter, to obtain a corrected high frequency time-domain signal; and
synthesizing, by the decoder, a narrow frequency time-domain signal of the current frame and the corrected high frequency time-domain signal and outputting, by the decoder, the synthesized signal.

2. The method according to claim 1 , wherein the obtaining a time-domain global gain parameter of the initial high frequency signal according to a spectrum tilt parameter of the current frame of speech/audio signal and a correlation between a narrow frequency signal of the current frame and a narrow frequency signal of a historical frame comprises:
classifying the current frame of speech/audio signal as a first type of signal or a second type of signal according to the spectrum tilt parameter of the current frame of speech/audio signal and the correlation between the narrow frequency signal of the current frame and the narrow frequency signal of the historical frame;
when the current frame of speech/audio signal is a first type of signal, limiting the spectrum tilt parameter to less than or equal to a first predetermined value, to obtain a limited spectrum tilt parameter value;
when the current frame of speech/audio signal is a second type of signal, limiting the spectrum tilt parameter to a value in a first range, to obtain a limited spectrum tilt parameter value; and
using the limited spectrum tilt parameter value as the time-domain global gain parameter of the initial high frequency signal.

3. The method according to claim 2 , wherein the first predetermined value is 8 and the first range is [0.5, 1].

4. The method according to claim 1 , further comprising:
obtaining, by the decoder, a time-domain envelope parameter corresponding to the initial high frequency signal, wherein
the correcting the initial high frequency signal by using the time-domain global gain parameter comprises:
correcting the initial high frequency signal by using the time-domain envelope parameter and the time-domain global gain parameter.

5. A speech/audio signal processing apparatus, comprising:
a processor;
a predicting unit controlled by the processor, configured to: when a speech/audio signal switches from a wide frequency signal to a narrow frequency signal, obtain an initial high frequency signal corresponding to a current frame of speech/audio signal;
a parameter obtaining unit controlled by the processor, configured to obtain a time-domain global gain parameter of the initial high frequency signal according to a spectrum tilt parameter of the current frame of speech/audio signal and a correlation between a narrow frequency signal of the current frame and a narrow frequency signal of a historical frame;
a weighting processing unit controlled by the processor, configured to perform weighting processing on an energy ratio and the time-domain global gain parameter, and use an obtained weighted value as a predicted global gain parameter, wherein the energy ratio is a ratio between energy of a historical frame of high frequency time-domain signal and energy of a current frame of initial high frequency signal;
a correcting unit controlled by the processor, configured to correct the initial high frequency signal by using the predicted global gain parameter, to obtain a corrected high frequency time-domain signal; and
a synthesizing unit controlled by the processor, configured to synthesize a narrow frequency time-domain signal of the current frame and the corrected high frequency time-domain signal and output the synthesized signal.

6. The apparatus according to claim 5 , wherein
the parameter obtaining unit is further configured to obtain a time-domain envelope parameter corresponding to the initial high frequency signal; and
the correcting unit is configured to correct the initial high frequency signal by using the time-domain envelope parameter and the time-domain global gain parameter.

7. The apparatus according to claim 5 , wherein the parameter obtaining unit comprises:
a classifying unit, configured to classify the current frame of speech/audio signal as a first type of signal or a second type of signal according to the spectrum tilt parameter of the current frame of speech/audio signal and the correlation between the narrow frequency signal of the current frame and the narrow frequency signal of the historical frame;
a first limiting unit, configured to: when the current frame of speech/audio signal is a first type of signal, limit the spectrum tilt parameter to less than or equal to a first predetermined value, to obtain a limited spectrum tilt parameter value, and use the limited spectrum tilt parameter value as the time-domain global gain parameter of the initial high frequency signal; and
a second limiting unit, configured to: when the current frame of speech/audio signal is a second type of signal, limit the spectrum tilt parameter to a value in a first range, to obtain a limited spectrum tilt parameter value, and use the limited spectrum tilt parameter value as the time-domain global gain parameter of the initial high frequency signal.

8. The apparatus according to claim 7 , wherein the first predetermined value is 8 and the first range is [0.5, 1].

9. A speech/audio signal processing apparatus, comprising:
a processor;
an acquiring unit controlled by the processor, configured to: when a speech/audio signal switches bandwidth, obtain an initial high frequency signal corresponding to a current frame of speech/audio signal;
a parameter obtaining unit controlled by the processor, configured to obtain a time-domain global gain parameter corresponding to the initial high frequency signal;
a weighting processing unit controlled by the processor, configured to perform weighting processing on an energy ratio and the time-domain global gain parameter, and use an obtained weighted value as a predicted global gain parameter, wherein the energy ratio is a ratio between energy of a historical frame of high frequency time-domain signal and energy of a current frame of initial high frequency signal;
a correcting unit controlled by the processor, configured to correct the initial high frequency signal by using the predicted global gain parameter, to obtain a corrected high frequency time-domain signal; and
a synthesizing unit controlled by the processor, configured to synthesize a narrow frequency time-domain signal of the current frame and the corrected high frequency time-domain signal and output the synthesized signal.

10. The apparatus according to claim 9 , wherein the bandwidth switching is switching from a narrow frequency signal to a wide frequency signal, and the apparatus further comprises:
a weighting factor setting uni

Assignees

• Huawei Tech Co Ltd

Inventors

• Liu Zexin
• Miao Lei

Classifications

• G10L19/083 Primary

  the excitation function being an excitation gain (G10L25/90 takes precedence) · CPC title

• G10L19/0204

  using subband decomposition · CPC title

• G10L21/038

  using band spreading techniques · CPC title

• G10L19/125

  Pitch excitation, e.g. pitch synchronous innovation CELP [PSI-CELP] · CPC title

• G10L21/0224 Primary

  Processing in the time domain · CPC title