AUDIO SIGNAL ENCODING AND DECODING METHOD, AND AUDIO SIGNAL ENCODING AND DECODING APPARATUS

• US 20180018989A1
• Filed: 09/28/2017
• Published: 01/18/2018
• Est. Priority Date: 01/11/2013
• 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: Liu, Zexin, Wang, Bin, Miao, Lei
• Granted Patent: US 10,373,629 B2
• Time in Patent Office: Days
• CPC Class Codes: G10L 19/0204 using subband decomposition
• CPC Class Codes: G10L 19/08 Determination or coding of the excitation function; Determination or coding of the long-term prediction parameters
• CPC Class Codes: G10L 19/24 Variable rate codecs, e.g. for generating different qualities using a scalable representation such as hierarchical encoding or layered encoding
• CPC Class Codes: G10L 19/265 Pre-filtering, e.g. high frequency emphasis prior to encoding
• CPC Class Codes: G10L 21/038 using band spreading techniques
• CPC Class Codes: G10L 21/0388 Details of processing therefor
• CPC Class Codes: G10L 25/93 Discriminating between voiced and unvoiced parts of speech signals G10L25/90 takes precedence

Abstract

An audio signal encoding and decoding method, an audio signal encoding and decoding apparatus, a transmitter, a receiver, and a communications system, which can improve encoding and/or decoding performance. The audio signal encoding method includes dividing a to-be-encoded time domain signal into a low band signal and a high band signal; encoding the low band signal to obtain a low frequency encoding parameter; calculating a voiced degree factor, and predicting a high band excitation signal; weighting the high band excitation signal and random noise using the voiced degree factor, so as to obtain a synthesized excitation signal; and obtaining a high frequency encoding parameter based on the synthesized excitation signal and the high band signal. Technical solutions in the embodiments of the present invention can improve an encoding or decoding effect.

Claims

1. An audio signal encoding method, comprising:

encoding a low band signal of an audio signal to obtain one or more low frequency encoding parameters;

calculating a voiced factor according to the one or more low frequency encoding parameters;

obtaining a high band excitation signal according to the one or more low frequency encoding parameters;

obtaining an emphasized noise by performing an emphasis operation on a random noise;

obtaining a synthesized excitation signal according to the emphasized noise, the high band excitation signal and the voiced factor; and

obtaining a high frequency encoding parameter based on the synthesized excitation signal and a high band signal of the audio signal.

2. The method according to claim 1, wherein obtaining a synthesized excitation signal according to the emphasized noise, the high band excitation signal and the voiced factor comprises:

obtaining the synthesized excitation signal by calculating a weighted sum of the high band excitation signal and the emphasized noise;

wherein weighting factor for calculating the weighted sum is obtained according to the voiced factor.

3. The method according to claim 1, wherein an emphasis factor of the emphasis operation on the random noise is a fixed value.

4. The method according to claim 1, wherein an emphasis factor of the emphasis operation on the random noise is greater than 0 and less than 1.

5. An audio signal decoding method, comprising:

obtaining a low frequency encoding parameter and a high frequency encoding parameter from an encoded audio signal;

obtaining a low band signal of the audio signal according to the low frequency encoding parameter;

calculating a voiced factor according to the low frequency encoding parameter;

obtaining a high band excitation signal according to the low frequency encoding parameter;

obtaining an emphasized noise by performing an emphasis operation on a random noise;

obtaining a synthesized excitation signal according to the emphasized noise, the high band excitation signal and the voiced factor;

obtaining a high band signal of the audio signal based on the synthesized excitation signal and the high frequency encoding parameter; and

obtaining the audio signal by combining the low band signal and the high band signal.

6. The method according to claim 5, wherein obtaining the synthesized excitation signal according to the emphasized noise, the high band excitation signal and the voiced factor comprises:

obtaining the synthesized excitation signal by calculating a weighted sum of the high band excitation signal and the emphasized noise;

weighting factor for calculating the weighted sum is obtained according to the voiced factor.

7. The method according to claim 5, wherein an emphasis factor of the emphasis operation on the random noise is a fixed value.

8. The method according to claim 5, wherein an emphasis factor of the emphasis operation on the random noise is greater than 0 and less than 1.

9. An audio signal encoding apparatus comprising:

a processor and a memory storing computer-readable instructions for execution by the processor;

wherein the processor is configured to execute the instructions to;

encode a low band signal of an audio signal to obtain one or more low frequency encoding parameters;

calculate a voiced factor according to the one or more low frequency encoding parameters;

obtain a high band excitation signal according to the one or more low frequency encoding parameters;

obtain an emphasized noise by performing an emphasis operation on a random noise;

obtain a synthesized excitation signal according to the emphasized noise, the high band excitation signal and the voiced factor; and

obtain a high frequency encoding parameter based on the synthesized excitation signal and a high band signal of the audio signal.

10. The apparatus according to claim 9, wherein in obtaining a synthesized excitation signal according to the emphasized noise, the high band excitation signal and the voiced factor, the processor is configured to:

obtain the synthesized excitation signal by calculating a weighted sum of the high band excitation signal and the emphasized noise;

wherein weighting factor for calculating the weighted sum is obtained according to the voiced factor.

11. The apparatus according to claim 9, wherein an emphasis factor of the emphasis operation on the random noise is a fixed value.

12. The apparatus according to claim 9, wherein an emphasis factor of the emphasis operation on the random noise is greater than 0 and less than 1.

13. An audio signal decoding apparatus, comprising:

a processor and a memory storing computer-readable instructions for execution by the processor;

wherein the processor is configured to execute the instructions to;

obtain a low frequency encoding parameter and a high frequency encoding parameter from an encoded audio signal;

obtain a low band signal of the audio signal according to the low frequency encoding parameter;

calculate a voiced factor according to the low frequency encoding parameter;

obtain a high band excitation signal according to the low frequency encoding parameter;

obtain an emphasized noise by performing an emphasis operation on a random noise;

obtain a synthesized excitation signal according to the emphasized noise, the high band excitation signal and the voiced factor;

obtain a high band signal of the audio signal based on the synthesized excitation signal and the high frequency encoding parameter; and

obtain the audio signal by combining the low band signal and the high band signal.

14. The apparatus according to claim 13, wherein in obtaining the synthesized excitation signal according to the emphasized noise, the high band excitation signal and the voiced factor, the processor is configured to:

obtain the synthesized excitation signal by calculating a weighted sum of the high band excitation signal and the emphasized noise;

weighting factor for calculating the weighted sum is obtained according to the voiced factor.

15. The apparatus according to claim 13, wherein an emphasis factor of the emphasis operation on the random noise is a fixed value.

16. The apparatus according to claim 13, wherein an emphasis factor of the emphasis operation on the random noise is greater than 0 and less than 1.