Frequency envelope vector quantization method and apparatus

• US 10,032,460 B2
• Filed: 09/26/2017
• Issued: 07/24/2018
• Est. Priority Date: 07/04/2013
• Status: Active Grant

• Current Assignee: Crystal Clear Codec, LLC
• Original Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Inventors: Hu, Chen, Miao, Lei, Liu, Zexin
• Primary Examiner(s): ROBERTS, SHAUN A
• Application Number:
  US15/715,179
• Publication Number:
  US 20180018980A1
• Time in Patent Office: 301 Days
• Field of Search: 704206, 704222, 704500
• CPC Class Codes: G10L 19/038 Vector quantisation, e.g. TwinVQ audio
• CPC Class Codes: G10L 19/06 Determination or coding of the spectral characteristics, e.g. of the short-term prediction coefficients
• CPC Class Codes: G10L 2019/0005 Multi-stage vector quantisation
• CPC Class Codes: H03M 7/3082 Vector coding for television signals, see H04N19/94

Abstract

Embodiments of the present application proposes a frequency envelope vector quantization method and apparatus, where the method includes: dividing N frequency envelopes in one frame into N1 vectors; quantizing a first vector in the N1 vectors by using a first codebook, to obtain a code word corresponding to the quantized first vector, where the first codebook is divided into 2^B1 portions; determining, according to the code word corresponding to the quantized first vector; determining a second codebook according to the codebook of the i^th portion; and quantizing a second vector in the N1 vectors based on the second codebook. In the embodiments of the present application, vector quantization can be performed on frequency envelope vectors by using a codebook with a smaller quantity of bits. Therefore, complexity of vector quantization can be reduced, and an effect of vector quantization can also be ensured.

Claims

1. A method of quantizing frequency envelops of an audio signal for use by an audio signal encoder, comprising:

obtaining N frequency envelopes of a frame of the audio signal, wherein N is an even integer;

organizing the N frequency envelopes into N1 groups, wherein each group comprises two frequency envelopes, and N=2×

N1;

quantizing a first group of frequency envelopes to obtain a first vector by using a codebook, wherein the codebook has 2^B code words and each code word corresponds to a vector, and B is a positive integer greater than or equal to 2;

determining if a code word corresponding to the first vector is in a first half of the codebook or in a second half of the codebook; and

if the code word corresponding to the first vector is in the first half of the codebook, quantizing a second group of frequency envelopes by using the first half of the codebook, or

if the code word corresponding to the first vector is in the second half of the codebook, quantizing a second group of frequency envelopes by using the second half of the codebook.

2. The method according to claim 1, wherein N is 8.

3. The method according to claim 2, wherein B is 4.

4. The method according to claim 1, wherein B is 4.

5. An audio signal encoding apparatus, comprising a processor and a memory storing program codes, wherein the program codes, when executed by the processor, cause the apparatus to perform a process that comprises:

obtaining N frequency envelopes of a frame of an audio signal, wherein N is an even integer;

organizing the N frequency envelopes into N1 groups, wherein each group comprises two frequency envelopes, and N=2×

N1;

quantizing a first group of frequency envelopes to obtain a first vector by using a codebook, wherein the codebook has 2^B code words and each code word corresponds to a vector, and B is a positive integer greater than or equal to 2;

determining if a code word corresponding to the first vector is in a first half of the codebook or in a second half of the codebook; and

if the code word corresponding to the first vector is in the first half of the codebook, quantizing a second group of frequency envelopes by using the first half of the codebook, or

if the code word corresponding to the first vector is in the second half of the codebook, quantizing a second group of frequency envelopes by using the second half of the codebook.

6. The apparatus according to claim 5, wherein N is 8.

7. The apparatus according to claim 6, wherein B is 4.

8. The apparatus according to claim 5, wherein B is 4.

9. A method of quantizing frequency envelops of an audio signal for use by an audio signal encoder, comprising:

obtaining N frequency envelopes of a frame of the audio signal, wherein N is an even integer;

organizing the N frequency envelopes into N1 groups, wherein each group comprises two frequency envelopes, and N=2×

N1;

quantizing a first group of frequency envelopes to obtain a first vector by using a codebook, wherein the codebook has 2^B code words and each code word corresponds to a vector, and B is a positive integer greater than or equal to 2;

determining if the first vector is in a first half of the codebook or in a second half of the codebook; and

if the first vector is in the first half of the codebook, quantizing a second group of frequency envelopes by using the first half of the codebook, or

if the first vector is in the second half of the codebook, quantizing a second group of frequency envelopes by using the second half of the codebook.

10. The method according to claim 9, wherein N is 8.

11. The method according to claim 10, wherein B is 4.

12. The method according to claim 9, wherein B is 4.

13. An audio signal encoding apparatus, comprising a processor and a memory storing program codes, wherein the program codes, when executed by the processor, cause the apparatus to perform a process that comprises:

obtaining N frequency envelopes of a frame of an audio signal, wherein N is an even integer;

organizing the N frequency envelopes into N1 groups, wherein each group comprises two frequency envelopes, and N=2×

N1;

quantizing a first group of frequency envelopes to obtain a first vector by using a codebook, wherein the codebook has 2^B code words and each code word corresponds to a vector, and B is a positive integer greater than or equal to 2;

determining if the first vector is in a first half of the codebook or in a second half of the codebook; and

if the first vector is in the first half of the codebook, quantizing a second group of frequency envelopes by using the first half of the codebook, or

if the first vector is in the second half of the codebook, quantizing a second group of frequency envelopes by using the second half of the codebook.

14. The apparatus according to claim 13, wherein N is 8.

15. The apparatus according to claim 14, wherein B is 4.

16. The apparatus according to claim 13, wherein B is 4.