Method for determining audio coding/decoding mode and related product

Patent metadata

Field	Value
Publication number	US-12469503-B2
Application number	US-202418440210-A
Country	US
Kind code	B2
Filing date	Feb 13, 2024
Priority date	Aug 10, 2017
Publication date	Nov 11, 2025
Grant date	Nov 11, 2025

Abstract

A method for determining an audio coding mode and a related apparatus are provided. The method may include: determining a channel combination scheme for a current frame, where the determined channel combination scheme for the current frame is one of a plurality of channel combination schemes; and determining a coding mode of the current frame based on a channel combination scheme for a previous frame and the channel combination scheme for the current frame, where the coding mode of the current frame is one of a plurality of coding modes. The technical solutions provided in embodiments of this application help improve encoding quality.

First claim

The invention claimed is:

1 . A method for determining a channel combination scheme, comprising:
obtaining a first signal type of a current frame of an audio signal, wherein the first signal type is either a near in phase signal or a near out of phase signal, and wherein the current frame includes a left channel signal and a right channel signal; obtaining a previous channel combination scheme of a first previous frame of the audio signal, wherein the previous channel combination scheme is either an anticorrelated signal channel combination scheme corresponding to the near out of phase signal or a correlated signal channel combination scheme corresponding to the near in phase signal; obtaining a first signal-to-noise ratio of the left channel signal and a second signal-to-noise ratio of the right channel signal; determining whether the first signal-to-noise ratio is greater than a preset threshold; determining whether the second signal-to-noise ratio is greater than the preset threshold; and in response to determining that the first signal type of the current frame is the near in phase signal, the previous channel combination scheme is the anticorrelated signal channel combination scheme, and both the first signal-to-noise ratio and the second signal-to-noise ratio are less than the preset threshold, determining that an initial channel combination scheme of the current frame is the correlated signal channel combination scheme.

2 . The method according to claim 1 , further comprising:
determining whether the initial channel combination scheme needs to be modified; and in response to determining that the initial channel combination scheme needs to be modified, obtaining a final channel combination scheme by modifying the initial channel combination scheme.

3 . The method according to claim 2 , wherein the determining whether the initial channel combination scheme needs to be modified comprises:
obtaining a channel combination ratio factor modification flag of the first previous frame; determining whether the current frame meets a switching condition when the channel combination ratio factor modification flag indicates that a channel combination ratio factor does not need to be modified; and determining the final channel combination scheme based on a result of determining whether the current frame meets the switching condition.

4 . The method according to claim 3 , wherein the determining whether the current frame meets a switching condition comprises:
obtaining a second signal type of a primary channel signal of the first previous frame; obtaining a third signal type of a primary channel signal of a second previous frame prior to the first previous frame; and determining that the current frame meets the switching condition when the second signal type is UNVOICED_CLAS and the third signal type is VOICED_TRANSITION.

5 . The method according to claim 3 , wherein the determining whether the current frame meets a switching condition comprises:
obtaining a fourth signal type of a secondary channel signal of the first previous frame; obtaining a fifth signal type of a secondary channel signal of a second previous frame prior to the first previous frame; and determining that the current frame meets the switching condition when the fourth signal type is UNVOICED_CLAS and the fifth signal type is VOICED_TRANSITION.

6 . An apparatus comprising:
at least one processor; and one or more memories coupled to the at least one processor and storing programming instructions, which when executed by the at least one processor, cause the apparatus to: obtain a first signal type of a current frame of an audio signal, wherein the first signal type is either a near in phase signal or a near out of phase signal, and wherein the current frame includes a left channel signal and a right channel signal; obtain a previous channel combination scheme of a first previous frame of the audio signal, wherein the previous channel combination scheme is either an anticorrelated signal channel combination scheme corresponding to the near out of phase signal or a correlated signal channel combination scheme corresponding to the near in phase signal; obtain a first signal-to-noise ratio of the left channel signal and a second signal-to-noise ratio of the right channel signal; determine whether the first signal-to-noise ratio is greater than a preset threshold; determine whether the second signal-to-noise ratio is greater than the preset threshold; and in response to determining that the first signal type of the current frame is the near in phase signal, the previous channel combination scheme is the anticorrelated signal channel combination scheme, and both the first signal-to-noise ratio and the second signal-to-noise ratio are less than the preset threshold, determine that an initial channel combination scheme of the current frame is the correlated signal channel combination scheme.

7 . The apparatus according to claim 6 , wherein the programming instructions, when executed by the at least one processor, cause the apparatus further to:
determine whether the initial channel combination scheme needs to be modified; and in response to determining that the initial channel combination scheme needs to be modified, obtain a final channel combination scheme by modifying the initial channel combination scheme.

8 . The apparatus according to claim 7 , wherein the programming instructions, when executed by the at least one processor, cause the apparatus further to:
obtain a channel combination ratio factor modification flag of the first previous frame; determine whether the current frame meets a switching condition when the channel combination ratio factor modification flag indicates that a channel combination ratio factor does not need to be modified; and determine the final channel combination scheme based on a result of determining whether the current frame meets the switching condition.

9 . The apparatus according to claim 8 , wherein the programming instructions, when executed by the at least one processor, cause the apparatus further to:
obtain a second signal type of a primary channel signal of the first previous frame; obtain a third signal type of a primary channel signal of a second previous frame prior to the first previous frame; and determine that the current frame meets the switching condition when the second signal type is UNVOICED_CLAS and the third signal type is VOICED_TRANSITION.

10 . The apparatus according to claim 8 , wherein the programming instructions, when executed by the at least one processor, cause the apparatus further to:
obtain a fourth signal type of a secondary channel signal of the first previous frame; obtain a fifth signal type of a secondary channel signal of a second previous frame prior to the first previous frame; and determine that the current frame meets the switching condition when the fourth signal type is UNVOICED_CLAS and the fifth signal type is VOICED_TRANSITION.

11 . A non-transitory computer-readable storage medium storing computer instructions, which when executed by one or more processors, cause the one or more processors to perform operations, the operations comprising:
obtaining a first signal type of a current frame of an audio signal, wherein the first signal type is either a near in phase signal or a near out of phase signal, and wherein the current frame includes a left channel signal and a right channel signal; obtaining a previous channel combination scheme of a first previous frame of the audio signal, wherein the previous channel combination scheme is either an anticorrelated signal channel combination scheme corresp

Assignees

• Huawei Tech Co Ltd

Inventors

• Wang Bin
• Li Haiting
• Miao Lei

Classifications

• G10L19/22 Primary

  Mode decision, i.e. based on audio signal content versus external parameters · CPC title

• H04S2420/03

  Application of parametric coding in stereophonic audio systems · CPC title

• H04S1/007

  in which the audio signals are in digital form (data reduction aspects thereof based on psychoacoustics G10L19/02) · CPC title

• G10L19/20

  using sound class specific coding, hybrid encoders or object based coding · CPC title

• G10L19/008 Primary

  Multichannel audio signal coding or decoding using interchannel correlation to reduce redundancy, e.g. joint-stereo, intensity-coding or matrixing · CPC title