Very short pitch detection and coding
AssigneeHuawei Technologies Co., Ltd.
InventorsYang Gao, Fengyan Qi
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Abstract
A method includes detecting whether there is a very short pitch lag in a speech or audio signal that is shorter than a conventional minimum pitch limitation using a combination of time domain and frequency domain pitch detection techniques. The pitch detection techniques include using pitch correlations in a time domain and detecting a lack of low frequency energy in the speech or audio signal in a frequency domain. The detected very short pitch lag is coded using a pitch range from a predetermined minimum very short pitch limitation that is smaller than the conventional minimum pitch limitation.
Claims21
A method for pitch detection implemented by an encoder, the method comprising:
- determining a value of an initial pitch lag candidate of a current frame of a signal in a range from a second minimum pitch limitation to a first minimum pitch limitation using a time domain pitch detection technique, wherein a value of the second minimum pitch limitation is less than a value of the first minimum pitch limitation, and wherein the signal is a speech signal or an audio signal;
- determining whether the current frame lacks low-frequency energy;
- and
- determining the initial pitch lag candidate as a final pitch lag when one or more conditions are met,
- wherein the one or more conditions comprise that the current frame lacks the low-frequency energy.
An audio signal encoder, comprising:
- a memory configured to store program instructions;
- and
- one or more processors coupled to the memory and configured to execute the program instructions to cause the audio signal encoder to be configured to:
- determine a value of an initial pitch lag candidate of a current frame of a signal in a range from a second minimum pitch limitation to a first minimum pitch limitation using a time domain pitch detection technique, wherein a value of the second minimum pitch limitation is less than a value of the first minimum pitch limitation, and wherein the signal is a speech signal or an audio signal;
- determine whether the current frame lacks low-frequency energy;
- and
- determine the initial pitch lag candidate as a final pitch lag when one or more conditions are met, wherein the one or more conditions comprise that the current frame lacks the low-frequency energy.
A computer program product comprising instructions that are stored on a computer-readable medium and that, when executed by a processor, cause an audio signal encoder to be configured to:
- determine a value of an initial pitch lag candidate of a current frame of a signal in a range from a second minimum pitch limitation to a first minimum pitch limitation using a time domain pitch detection technique, wherein a value of the second minimum pitch limitation is less than a value of the first minimum pitch limitation, and wherein the signal is a speech signal or an audio signal;
- determine whether the current frame lacks low-frequency energy;
- and
- determine the initial pitch lag candidate as a final pitch lag when one or more conditions are met, wherein the one or more conditions comprise that the current frame lacks the low-frequency energy.
Dependencies are inferred from the claim text.