Speech/audio bitstream decoding method and apparatus

Patent metadata

Field	Value
Publication number	US-11031020-B2
Application number	US-201916358237-A
Country	US
Kind code	B2
Filing date	Mar 19, 2019
Priority date	Mar 21, 2014
Publication date	Jun 8, 2021
Grant date	Jun 8, 2021

Abstract

A speech/audio bitstream decoding method includes acquiring a speech/audio decoding parameter of a current speech/audio frame, where the foregoing current speech/audio frame is a redundant decoded frame or a speech/audio frame previous to the foregoing current speech/audio frame is a redundant decoded frame, performing post processing on the acquired speech/audio decoding parameter according to speech/audio parameters of X speech/audio frames, where the foregoing X speech/audio frames include M speech/audio frames previous to the foregoing current speech/audio frame and/or N speech/audio frames next to the foregoing current speech/audio frame, and recovering a speech/audio signal using the post-processed speech/audio decoding parameter of the foregoing current speech/audio frame. The technical solutions of the speech/audio bitstream decoding method help improve quality of an output speech/audio signal.

First claim

The invention claimed is:

1. A method for decoding a speech/audio an audio bitstream at a decoder, comprising:
acquiring a decoding parameter of a first frame, wherein the first frame or a second frame previous to the first frame is a redundant decoded frame, wherein a decoding parameter of the redundant decoded frame is obtained based on redundant bitstream information carried in another frame, and wherein the decoding parameter comprises at least one of an adaptive codebook gain, a spectrum tilt factor, or a spectral pair parameter;
performing post processing on the decoding parameter of the first frame according to parameters of one or more frames previous to the first frame and parameters of one or more frames next to the first frame to obtain a post-processed decoding parameter of the first frame, wherein the parameters of the one or more frames previous to the first frame comprise at least one of decoding parameters or a signal class of the one or more frames previous to the first frame, and wherein the parameters of the one or more frames next to the first frame comprise at least one of decoding parameters or a signal class of the one or more frames next to the first frame; and
recovering a speech/audio signal corresponding to the first frame using the post-processed decoding parameter of the first frame.

2. The method of claim 1 , wherein the decoding parameter of the first frame comprises a spectral pair parameter of the first frame, and wherein performing the post processing comprises performing the post processing on the spectral pair parameter of the first frame according to at least one of a signal class or a spectral pair parameter of the one or more frames previous to the first frame, and at least one of a signal class or a spectral pair parameter of the one or more frames next to the first frame to obtain a post-processed spectral pair parameter of the first frame.

3. The method of claim 1 , wherein the decoding parameter of the first frame comprises an adaptive codebook gain of the first frame, and wherein performing the post processing comprises adjusting the adaptive codebook gain of the first frame according to at least one of a signal class, an algebraic codebook gain, or an adaptive codebook gain of the one or more frames previous to the first frame, and at least one of a signal class, an algebraic codebook gain, or an adaptive codebook gain of the one or more frames next to the first frame to obtain a post-processed adaptive codebook gain of the first frame.

4. The method of claim 3 , wherein adjusting the adaptive codebook gain comprises attenuating an adaptive codebook gain of a subframe of the first frame, wherein the first frame is the redundant decoded frame, wherein a signal class of the first frame is not unvoiced, wherein a signal class of at least one of two frames next to the first frame is unvoiced, and wherein an algebraic codebook gain of the subframe is greater than or equal to an algebraic codebook gain of a previous frame adjacent to the first frame.

5. The method of claim 3 , wherein adjusting the adaptive codebook gain comprises attenuating an adaptive codebook gain of a subframe of the first frame, wherein the first frame is the redundant decoded frame, wherein a signal class of the first frame is not unvoiced, wherein a signal class of at least one of two frames next to the first frame is unvoiced, and wherein an algebraic codebook gain of the subframe is greater than or equal to an algebraic codebook gain of a subframe previous to the subframe.

6. The method of claim 1 , wherein the decoding parameter of the first frame comprises an algebraic codebook of the first frame, and wherein performing the post processing comprises performing the post processing on the algebraic codebook of the first frame according to at least one of a signal class, an algebraic codebook, or a spectrum tilt factor of the one or more frames previous to the first frame, and at least one of a signal class, an algebraic codebook, or a spectrum tilt factor of the one or more frames next to the first frame to obtain a post-processed algebraic codebook of the first frame.

7. The method of claim 1 , wherein the decoding parameter of the first frame comprises a bandwidth extension envelope of the first frame, and wherein performing the post processing comprises performing the post processing on the bandwidth extension envelope of the first frame according to at least one of a signal class, a bandwidth extension envelope, or a spectrum tilt factor of the one or more frames previous to the first frame and at least one of a signal class, a bandwidth extension envelope, or a spectrum tilt factor of the one or more frames next to the first frame to obtain a post-processed bandwidth extension envelope of the first frame.

8. The method of claim 7 , wherein performing the post processing on the bandwidth extension envelope of the first frame comprises obtaining the post-processed bandwidth extension envelope of the first frame based on a bandwidth extension envelope of the second frame and the bandwidth extension envelope of the first frame, wherein the second frame is a normal decoded frame, and wherein a signal class of the second frame is the same as that of a frame next to the first frame.

9. The method of claim 8 , wherein the first frame is a prediction form of redundancy decoding, and wherein the method further comprises obtaining the post-processed bandwidth extension envelope of the first frame based on a bandwidth extension envelope of a frame previous to the first frame and the bandwidth extension envelope of the first frame.

10. A decoder for decoding a speech/audio bitstream, comprising:
a memory storing instructions; and
a processor coupled to the memory, wherein the instructions cause the processor to be configured to:
acquire a decoding parameter of a first frame, wherein the first frame or a second frame previous to the first frame is a redundant decoded frame, wherein a decoding parameter of the redundant decoded frame is obtained based on redundant bitstream information carried in another frame, and wherein the decoding parameter comprises at least one of an adaptive codebook gain, a spectrum tilt factor, or a spectral pair parameter;
perform post processing on the decoding parameter of the first frame according to parameters of one or more frames previous to the first frame and parameters of one or more frames next to the first frame to obtain a post-processed decoding parameter of the first frame, wherein the parameters of the one or more frames previous to the first frame comprise at least one of decoding parameters or a signal class of the one or more frames previous to the first frame, and wherein the parameters of the one or more frames next to the first frame comprise at least one of decoding parameters or a signal class of the one or more frames next to the first frame; and
recover a speech/audio signal corresponding to the first frame using the post-processed decoding parameter of the first frame.

11. The decoder of claim 10 , wherein the decoding parameter of the first frame comprises a spectral pair parameter of the first frame, and wherein the instructions further cause the processor to perform the post processing on the spectral pair parameter of the first frame according to at least one of a spectral pair parameter or a signal class of the one or more frames previous to the first frame, and at least one of a signal class or a spectral pair parameter of the one or more frames next to the first frame to obtain a post-processed spectral pair parameter of the first frame.

12. The decoder of claim 10 , wherein the decoding parameter of the first frame comprises

Assignees

• Huawei Tech Co Ltd

Inventors

• Zhang Xingtao
• Liu Zexin
• Miao Lei

Classifications

• G10L2019/0002

  Codebook adaptations · CPC title

• G10L25/78

  Detection of presence or absence of voice signals (switching of direction of transmission by voice frequency in two-way loud-speaking telephone systems H04M9/10) · CPC title

• G10L19/005 Primary

  Correction of errors induced by the transmission channel, if related to the coding algorithm · CPC title

• G10L19/26

  Pre-filtering or post-filtering · CPC title

• G10L19/167

  Audio streaming, i.e. formatting and decoding of an encoded audio signal representation into a data stream for transmission or storage purposes · CPC title