METHOD AND APPARATUS FOR ENCODING AND DECODING AUDIO SIGNAL USING LAYERED SINUSOIDAL PULSE CODING

• US 20120095754A1
• Filed: 05/19/2010
• Published: 04/19/2012
• Est. Priority Date: 05/19/2009
• Status: Active Grant

• Current Assignee: Electronics and Telecommunications Research Institute
• Original Assignee: Electronics and Telecommunications Research Institute
• Inventors: Lee, Mi-Suk, Sung, Jongmo, Bae, Hyun-Joo, Lee, Byung-Sun, Yang, Heesik, Kim, Hyun-Woo
• Granted Patent: US 8,805,680 B2
• Time in Patent Office: Days
• US Class Current: 704/203
• CPC Class Codes: G10L 19/02 using spectral analysis, e.g. transform vocoders or subband vocoders
• CPC Class Codes: G10L 19/0212 using orthogonal transformation
• 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

Abstract

Provided are a method and an apparatus for encoding and decoding an audio signal. A method for encoding an audio signal includes receiving a transformed audio signal, dividing the transformed audio signal into a plurality of subbands, performing a first sinusoidal pulse coding operation on the subbands, determining a performance region of a second sinusoidal pulse coding operation among the subbands on the basis of coding information of the first sinusoidal pulse coding operation, and performing the second sinusoidal pulse coding operation on the determined performance region, wherein the first sinusoidal pulse coding operation is performed variably according to the coding information. Accordingly, it is possible to further improve the quality of a synthesized signal by considering the sinusoidal pulse coding of a lower layer when encoding or decoding an audio signal in an upper layer by a layered sinusoidal pulse coding scheme.

Claims

1. A method for encoding an audio signal, comprising:

receiving a transformed audio signal;

dividing the transformed audio signal into a plurality of subbands;

performing a first sinusoidal pulse coding operation on the subbands;

determining a performance region of a second sinusoidal pulse coding operation among the subbands on the basis of coding information of the first sinusoidal pulse coding operation; and

performing the second sinusoidal pulse coding operation on the determined performance region,

wherein the first sinusoidal pulse coding operation is performed variably according to the coding information.

2. The method of claim 1, wherein the coding information is information about the number of bits allocated for the first sinusoidal pulse coding operation, or information about the number of pulses allocated for the first sinusoidal pulse coding operation.

3. The method of claim 1, wherein said determining a performance region of a second sinusoidal pulse coding operation among the subbands on the basis of coding information of the first sinusoidal pulse coding operation comprises:

determining a lower band of the subbands as the performance region of the second sinusoidal pulse coding operation if the coding information is smaller than a predetermined value; and

determining an upper band of the subbands as the performance region of the second sinusoidal pulse coding operation if the coding information is greater than or equal to the predetermined value.

4. An apparatus for encoding an audio signal, comprising:

an input unit configured to receive a transformed audio signal;

an operation unit configured to divide the transformed audio signal into a plurality of subbands;

a first sinusoidal pulse coding unit configured to perform a first sinusoidal pulse coding operation on the subbands; and

a second sinusoidal pulse coding unit configured to determine a performance region of a second sinusoidal pulse coding operation among the subbands on the basis of coding information of the first sinusoidal pulse coding operation, and perform the second sinusoidal pulse coding operation on the determined performance region,

wherein the first sinusoidal pulse coding unit performs the first sinusoidal pulse coding operation variably according to the coding information.

5. The apparatus of claim 4, wherein the coding information is information about the number of bits allocated for the first sinusoidal pulse coding operation, or information about the number of pulses allocated for the first sinusoidal pulse coding operation.

6. The apparatus of claim 4, wherein the second sinusoidal pulse coding unit determines a lower band of the subbands as the performance region of the second sinusoidal pulse coding operation if the coding information is smaller than a predetermined value, and determines an upper band of the subbands as the performance region of the second sinusoidal pulse coding operation if the coding information is greater than or equal to the predetermined value.

7. A method for decoding an audio signal, comprising:

receiving a transformed audio signal;

dividing the transformed audio signal into a plurality of subbands;

performing a first sinusoidal pulse decoding operation on the subbands;

determining a performance region of a second sinusoidal pulse decoding operation among the subbands on the basis of decoding information of the first sinusoidal pulse decoding operation; and

performing the second sinusoidal pulse decoding operation on the determined performance region,

wherein the first sinusoidal pulse decoding operation is performed variably according to the decoding information.

8. The method of claim 7, wherein the decoding information is information about the number of bits allocated for the first sinusoidal pulse decoding operation, or information about the number of pulses allocated for the first sinusoidal pulse decoding operation.

9. The method of claim 7, wherein said determining a performance region of a second sinusoidal pulse decoding operation among the subbands on the basis of decoding information of the first sinusoidal pulse decoding operation comprises:

determining a lower band of the subbands as the performance region of the second sinusoidal pulse decoding operation if the decoding information is smaller than a predetermined value; and

determining an upper band of the subbands as the performance region of the second sinusoidal pulse decoding operation if the decoding information is greater than or equal to the predetermined value.

10. An apparatus for decoding an audio signal, comprising:

an input unit configured to receive a transformed audio signal;

an operation unit configured to divide the transformed audio signal into a plurality of subbands;

a first sinusoidal pulse decoding unit configured to perform a first sinusoidal pulse decoding operation on the subbands; and

a second sinusoidal pulse decoding unit configured to determine a performance region of a second sinusoidal pulse decoding operation among the subbands on the basis of decoding information of the first sinusoidal pulse decoding operation, and perform the second sinusoidal pulse decoding operation on the determined performance region,

wherein the first sinusoidal pulse decoding unit performs the first sinusoidal pulse decoding operation variably according to the decoding information.

11. The apparatus of claim 10, wherein the decoding information is information about the number of bits allocated for the first sinusoidal pulse decoding operation, or information about the number of pulses allocated for the first sinusoidal pulse decoding operation.

12. The apparatus of claim 10, wherein the second sinusoidal pulse decoding unit determines a lower band of the subbands as the performance region of the second sinusoidal pulse decoding operation if the decoding information is smaller than a predetermined value, and determines an upper band of the subbands as the performance region of the second sinusoidal pulse decoding operation if the decoding information is greater than or equal to the predetermined value.