AUDIO CODING METHOD AND RELATED APPARATUS

• US 20170047078A1
• Filed: 10/28/2016
• Published: 02/16/2017
• Est. Priority Date: 04/29/2014
• Status: Active Grant

• Current Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Original Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Inventors: Wang, Zhe
• Granted Patent: US 10,262,671 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G10L 19/02 using spectral analysis, e.g. transform vocoders or subband vocoders
• CPC Class Codes: G10L 19/04 using predictive techniques
• CPC Class Codes: G10L 19/12 the excitation function being a code excitation, e.g. in code excited linear prediction [CELP] vocoders
• CPC Class Codes: G10L 19/20 using sound class specific coding, hybrid encoders or object based coding
• CPC Class Codes: G10L 19/22 Mode decision, i.e. based on audio signal content versus external parameters

Abstract

An audio coding method and a related apparatus are disclosed. The audio coding method includes: estimating reference linear prediction efficiency of a current audio frame; determining an audio coding scheme that matches the reference linear prediction efficiency of the foregoing current audio frame; and performing audio coding on the foregoing current audio frame according to the audio coding scheme that matches the reference linear prediction efficiency of the foregoing current audio frame. The technical solutions provided in embodiments of the present disclosure help reduce overheads of audio coding.

Claims

1. An audio coding method, comprising:

estimating reference linear prediction efficiency of a current audio frame;

determining an audio coding scheme that matches the reference linear prediction efficiency of the current audio frame; and

performing audio coding on the current audio frame according to the audio coding scheme that matches the reference linear prediction efficiency of the current audio frame.

2. The method according to claim 1, wherein,

the reference linear prediction efficiency comprises at least one of the following linear prediction efficiency:

reference long-term linear prediction efficiency, reference short-term linear prediction efficiency, and reference integrated linear prediction efficiency.

3. The method according to claim 2, wherein,

if the reference linear prediction efficiency of the current audio frame comprises reference short-term linear prediction efficiency of the current audio frame, the determining an audio coding scheme that matches the reference linear prediction efficiency of the current audio frame comprises:

if the reference short-term linear prediction efficiency of the current audio frame is greater than or equal to a fifth threshold, determining that the audio coding scheme that matches the reference linear prediction efficiency of the current audio frame is a linear prediction based audio coding scheme.

4. The method according to claim 2, wherein,

if the reference linear prediction efficiency of the current audio frame comprises reference short-term linear prediction efficiency of the current audio frame, the determining an audio coding scheme that matches the reference linear prediction efficiency of the current audio frame comprises:

if the reference short-term linear prediction efficiency of the current audio frame is less than a fifth threshold, determining that the audio coding scheme that matches the reference linear prediction efficiency of the current audio frame is an audio coding scheme not based on linear prediction.

5. The method according to claim 3, wherein,

if the reference short-term linear prediction efficiency of the current audio frame is less than a fifth threshold, determining that the audio coding scheme that matches the reference linear prediction efficiency of the current audio frame is an audio coding scheme not based on linear prediction.

6. The method according to claim 2, wherein,

if the reference linear prediction efficiency of the current audio frame comprises reference short-term linear prediction efficiency of the current audio frame, the determining an audio coding scheme that matches the reference linear prediction efficiency of the current audio frame comprises:

determining a second linear prediction efficiency interval within which the reference short-term linear prediction efficiency of the current audio frame falls, and determining, according to a mapping relationship between a linear prediction efficiency interval and a linear prediction based audio coding scheme, a second audio coding scheme that is in a mapping relationship with the second linear prediction efficiency interval, wherein the second audio coding scheme is an audio coding scheme that matches the reference linear prediction efficiency of the current audio frame, and the second audio coding scheme is a linear prediction based audio coding scheme or an audio coding scheme not based on linear prediction.

7. The method according to claim 2, wherein,

the reference short-term linear prediction efficiency of the current audio frame is obtained by means of estimation in the following manner:

estimating short-term linear prediction efficiency of the current audio frame, wherein the short-term linear prediction efficiency of the current audio frame is the reference short-term linear prediction efficiency of the current audio frame.

8. The method according to claim 2, wherein,

the reference short-term linear prediction efficiency of the current audio frame is obtained by means of estimation in the following manner:

obtaining short-term linear prediction efficiency of the current audio frame by means of estimation;

acquiring linear prediction efficiency of N5 history audio frames of the current audio frame; and

calculating a fourth statistical value of the linear prediction efficiency of the N5 history audio frames and the short-term linear prediction efficiency of the current audio frame, wherein N5 is a positive integer, the fourth statistical value is the reference short-term linear prediction efficiency of the current audio frame, linear prediction efficiency of each history audio frame of N51 history audio frames is at least one of the following linear prediction efficiency;

long-term linear prediction efficiency, short-term linear prediction efficiency, and integrated linear prediction efficiency, and the N51 history audio frames are a subset of the N5 history audio frames.

9. The method according to claim 2, wherein,

the reference short-term linear prediction efficiency of the current audio frame is obtained by means of estimation in the following manner:

obtaining short-term linear prediction efficiency of the current audio frame by means of estimation;

acquiring reference linear prediction efficiency of N6 history audio frames of the current audio frame; and

calculating a fifth statistical value of the reference linear prediction efficiency of the N6 history audio frames and the short-term linear prediction efficiency of the current audio frame, wherein N6 is a positive integer, the fifth statistical value is the reference short-term linear prediction efficiency of the current audio frame, reference linear prediction efficiency of each history audio frame of N61 history audio frames is at least one of the following linear prediction efficiency;

reference long-term linear prediction efficiency, reference short-term linear prediction efficiency, and reference integrated linear prediction efficiency, and the N61 history audio frames are a subset of the N6 history audio frames.

10. The method according to claim 2, wherein,

the reference short-term linear prediction efficiency of the current audio frame is obtained by means of estimation in the following manner:

obtaining short-term linear prediction efficiency of the current audio frame by means of estimation;

acquiring reference linear prediction efficiency of N8 history audio frames of the current audio frame;

acquiring linear prediction efficiency of N7 history audio frames of the current audio frame; and

calculating a sixth statistical value of the linear prediction efficiency of the N7 history audio frames, the reference linear prediction efficiency of the N8 history audio frames, and the short-term linear prediction efficiency of the current audio frame, wherein N7 and N8 are positive integers, the sixth statistical value is the reference short-term linear prediction efficiency of the current audio frame, linear prediction efficiency of each history audio frame of N71 history audio frames is at least one of the following linear prediction efficiency;

long-term linear prediction efficiency, short-term linear prediction efficiency, and integrated linear prediction efficiency, reference linear prediction efficiency of each history audio frame of N81 history audio frames is at least one of the following linear prediction efficiency;

reference long-term linear prediction efficiency, reference short-term linear prediction efficiency, and reference integrated linear prediction efficiency, the N71 history audio frames are a subset of the N7 history audio frames, and the N81 history audio frames are a subset of the N8 history audio frames.

11. The method according to claim 7, wherein,

the obtaining short-term linear prediction efficiency of the current audio frame by means of estimation comprises:

obtaining the short-term linear prediction efficiency of the current audio frame based on a linear-prediction residual of the current audio frame.

12. The method according to claim 11, wherein,

the obtaining the short-term linear prediction efficiency of the current audio frame based on a linear-prediction residual of the current audio frame comprises:

calculating a change rate of energy that is of the current audio frame and obtained before and after short-term linear prediction is performed on the current audio frame, wherein the energy change rate is the short-term linear prediction efficiency of the current audio frame, or the short-term linear prediction efficiency of the current audio frame is obtained by means of transformation based on the energy change rate, and the energy that is of the current audio frame and obtained after the short-term linear prediction is performed on the current audio frame is energy of the linear-prediction residual of the current audio frame.

13. The method according to claim 12, wherein.

the change rate of the energy that is of the current audio frame and obtained before and after the short-term linear prediction is performed on the current audio frame is a ratio of the energy that is of the current audio frame and obtained before the short-term linear prediction is performed on the current audio frame to the energy of the linear-prediction residual of the current audio frame.

14. An audio coder, comprising:

an estimation unit, configured to estimate reference linear prediction efficiency of a current audio frame;

a determining unit, configured to determine an audio coding scheme that matches the reference linear prediction efficiency of the current audio frame that is estimated by the estimation unit; and

a coding unit, configured to perform audio coding on the current audio frame according to the audio coding scheme that matches the reference linear prediction efficiency of the current audio frame and that is determined by the determining unit.

15. The audio coder according to claim 14, wherein,

the reference linear prediction efficiency comprises at least one of the following linear prediction efficiency:

reference long-term linear prediction efficiency, reference short-term linear prediction efficiency, and reference integrated linear prediction efficiency.

16. The audio coder according to claim 15, wherein,

if the reference linear prediction efficiency of the current audio frame comprises reference short-term linear prediction efficiency of the current audio frame, the determining unit is specifically configured to:

if the reference short-term linear prediction efficiency of the current audio frame is greater than or equal to a fifth threshold, determine that the audio coding scheme that matches the reference linear prediction efficiency of the current audio frame is a linear prediction based audio coding scheme.

17. The audio coder according to claim 15, wherein,

if the reference linear prediction efficiency of the current audio frame comprises reference short-term linear prediction efficiency of the current audio frame, the determining unit is specifically configured to

if the reference short-term linear prediction efficiency of the current audio frame is less than a fifth threshold, determine that the audio coding scheme that matches the reference linear prediction efficiency of the current audio frame is an audio coding scheme not based on linear prediction.

18. The audio coder according to claim 16, wherein,

if the reference short-term linear prediction efficiency of the current audio frame is greater than or equal to a fifth threshold, determine that the audio coding scheme that matches the reference linear prediction efficiency of the current audio frame is a linear prediction based audio coding scheme.

19. The audio coder according to claim 15, wherein,

if the reference linear prediction efficiency of the current audio frame comprises reference short-term linear prediction efficiency of the current audio frame, the determining unit is specifically configured to:

determine a second linear prediction efficiency interval within which the reference short-term linear prediction efficiency of the current audio frame falls, and determine, according to a mapping relationship between a linear prediction efficiency interval and a linear prediction based audio coding scheme, a second audio coding scheme that is in a mapping relationship with the second linear prediction efficiency interval, wherein the second audio coding scheme is an audio coding scheme that matches the reference linear prediction efficiency of the current audio frame, and the second audio coding scheme is a linear prediction based audio coding scheme or an audio coding scheme not based on linear prediction.

20. The audio coder according to claim 15, wherein.

in an aspect of estimating the reference short-term linear prediction efficiency of the current audio frame, the estimation unit is specifically configured to:

estimate short-term linear prediction efficiency of the current audio frame, wherein the short-term linear prediction efficiency of the current audio frame is the reference short-term linear prediction efficiency of the current audio frame.

21. The audio coder according to claim 15, wherein,

in an aspect of estimating the reference short-term linear prediction efficiency of the current audio frame, the estimation unit is specifically configured to:

obtain short-term linear prediction efficiency of the current audio frame by means of estimation;

acquire linear prediction efficiency of N5 history audio frames of the current audio frame; and

calculate a fourth statistical value of the linear prediction efficiency of the N5 history audio frames and the short-term linear prediction efficiency of the current audio frame, wherein N5 is a positive integer, the fourth statistical value is the reference short-term linear prediction efficiency of the current audio frame, linear prediction efficiency of each history audio frame of N51 history audio frames is at least one of the following linear prediction efficiency;

long-term linear prediction efficiency, short-term linear prediction efficiency, and integrated linear prediction efficiency, and the N51 history audio frames are a subset of the N5 history audio frames.

22. The audio coder according to claim 15, wherein,

in an aspect of estimating the reference short-term linear prediction efficiency of the current audio frame, the estimation unit is specifically configured to:

obtain short-term linear prediction efficiency of the current audio frame by means of estimation;

acquire reference linear prediction efficiency of N6 history audio frames of the current audio frame; and

calculate a fifth statistical value of the reference linear prediction efficiency of the N6 history audio frames and the short-term linear prediction efficiency of the current audio frame, wherein N6 is a positive integer, the fifth statistical value is the reference short-term linear prediction efficiency of the current audio frame, reference linear prediction efficiency of each history audio frame of N61 history audio frames is at least one of the following linear prediction efficiency;

reference long-term linear prediction efficiency, reference short-term linear prediction efficiency, and reference integrated linear prediction efficiency, and the N61 history audio frames are a subset of the N6 history audio frames.

23. The audio coder according to claim 15, wherein,

in an aspect of estimating the reference short-term linear prediction efficiency of the current audio frame, the estimation unit is specifically configured to:

obtain short-term linear prediction efficiency of the current audio frame by means of estimation;

acquire reference linear prediction efficiency of N8 history audio frames of the current audio frame;

acquire linear prediction efficiency of N7 history audio frames of the current audio frame; and

calculate a sixth statistical value of the linear prediction efficiency of the N7 history audio frames, the reference linear prediction efficiency of the N8 history audio frames, and the short-term linear prediction efficiency of the current audio frame, wherein N7 and N8 are positive integers, the sixth statistical value is the reference short-term linear prediction efficiency of the current audio frame, linear prediction efficiency of each history audio frame of N71 history audio frames is at least one of the following linear prediction efficiency;

long-term linear prediction efficiency, short-term linear prediction efficiency, and integrated linear prediction efficiency, reference linear prediction efficiency of each history audio frame of N81 history audio frames is at least one of the following linear prediction efficiency;

reference long-term linear prediction efficiency, reference short-term linear prediction efficiency, and reference integrated linear prediction efficiency, the N71 history audio frames are a subset of the N7 history audio frames, and the N81 history audio frames are a subset of the N8 history audio frames.

24. The audio coder according to claim 20, wherein,

in the aspect of obtaining short-term linear prediction efficiency of the current audio frame by means of estimation, the estimation unit is specifically configured to obtain the short-term linear prediction efficiency of the current audio frame based on a linear-prediction residual of the current audio frame.

25. The audio coder according to claim 24, wherein,

in the aspect of obtaining the short-term linear prediction efficiency of the current audio frame based on a linear-prediction residual of the current audio frame, the estimation unit is specifically configured to calculate a change rate of energy that is of the current audio frame and obtained before and after short-term linear prediction is performed on the current audio frame, wherein the energy change rate is the short-term linear prediction efficiency of the current audio frame, or the short-term linear prediction efficiency of the current audio frame is obtained by means of transformation based on the energy change rate, and the energy that is of the current audio frame and obtained after the short-term linear prediction is performed on the current audio frame is energy of the linear-prediction residual of the current audio frame.

26. The audio coder according to claim 25, wherein,

the change rate of the energy that is of the current audio frame and obtained before and after the short-term linear prediction is performed on the current audio frame is a ratio of the energy that is of the current audio frame and obtained before the short-term linear prediction is performed on the current audio frame to the energy of the linear-prediction residual of the current audio frame.