METHOD AND APPARATUS FOR ENCODING AND DECODING AUDIO SIGNAL USING ADAPTIVE SINUSOIDAL CODING

• US 20140310007A1
• Filed: 06/26/2014
• Published: 10/16/2014
• Est. Priority Date: 02/16/2009
• Status: Active Grant

• Current Assignee: Electronics and Telecommunications Research Institute
• Original Assignee: Electronics and Telecommunications Research Institute
• Inventors: LEE, Mi-Suk, Bae, Hyun-Joo, Lee, Byung-Sun
• Granted Patent: US 9,251,799 B2
• Time in Patent Office: Days
• US Class Current: 704/500
• CPC Class Codes: G10L 19/008 Multichannel audio signal coding or decoding using interchannel correlation to reduce redundancy, e.g. joint-stereo, intensity-coding or matrixing
• CPC Class Codes: G10L 19/0204 using subband decomposition
• CPC Class Codes: G10L 19/093 using sinusoidal excitation models
• 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

A method and an apparatus for encoding and decoding audio signals using adaptive sinusoidal coding are provided. The audio signal encoding method includes the steps of dividing a synthesized audio signal into a plurality of sub-bands, calculating the energy of each sub-band, selecting a predetermined number of sub-bands having a relatively large amount of energy from the sub-bands, and performing sinusoidal coding with regard to the selected sub-bands. Application of sinusoidal coding based on consideration of the amount of energy of each sub-band of the synthesized signal improves the quality of the synthesized signal more efficiently.

Claims

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

receiving a transformed audio signal;

dividing the transformed audio signal into a plurality of sub-bands;

calculating energy of each of the sub-bands;

selecting a predetermined number of sub-bands in the order of a large amount of energy of the sub-bands; and

performing sinusoidal coding with regard to the selected sub-bands.

2. The method of claim 1, wherein the performing sinusoidal coding with regard to the selected sub-bands comprises:

selecting the selected sub-bands as a search track for the sinusoidal coding based on the amount of energy of the sub-bands; and

performing the sinusoidal coding with regard to the search track.

3. The method of claim 2, wherein the performing sinusoidal coding with regard to the selected sub-bands, adjacent sub-bands among the selected sub-bands are selected as one search track.

4. The method of claim 1, wherein the performing sinusoidal coding with regard to the selected sub-bands comprises:

merging adjacent sub-bands among the selected sub-bands into one sub-band; and

performing the sinusoidal coding with regard to the merged sub-band.

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

an input unit configured to receive a transformed audio signal;

a calculation unit configured to divide the transformed audio signal into a plurality of sub-bands, calculate energy of each of the sub-bands, and select a predetermined number of sub-bands in the order of a large amount of energy of the sub-bands; and

a coding unit configured to perform sinusoidal coding with regard to the selected sub-bands.

6. The apparatus of claim 5, wherein the coding unit selects the selected sub-bands as a search track for the sinusoidal coding based on the amount of energy of the sub-bands, and performs the sinusoidal coding with regard to the search track.

7. The apparatus of claim 6, wherein the coding unit selects adjacent sub-bands among the selected sub-bands as one search track.

8. The apparatus of claim 5, wherein the coding unit merges adjacent sub-bands among the selected sub-bands into one sub-band, and performs the sinusoidal coding with regard to the merged sub-band.

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

receiving a transformed audio signal;

dividing the transformed audio signal into a plurality of sub-bands;

calculating energy of each of the sub-bands;

selecting a predetermined number of sub-bands in the order of a large amount of energy of the sub-bands; and

performing sinusoidal decoding with regard to the selected sub-bands.

10. The method of claim 9, wherein the performing sinusoidal decoding with regard to the selected sub-bands comprises:

selecting the selected sub-bands as a search track for the sinusoidal decoding based on the amount of energy of the sub-bands; and

performing the sinusoidal decoding with regard to the search track.

11. The method of claim 10, wherein the performing sinusoidal decoding with regard to the selected sub-bands, adjacent sub-bands among the selected sub-bands are selected as one search track.

12. The method of claim 9, wherein the performing sinusoidal decoding with regard to the selected sub-bands comprises:

merging adjacent sub-bands among the selected sub-bands into one sub-band; and

performing the sinusoidal decoding with regard to the merged sub-band.

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

an input unit configured to receive a transformed audio signal;

a calculation unit configured to divide the transformed audio signal into a plurality of sub-bands, calculate energy of each of the sub-bands, and select a predetermined number of sub-bands in the order of a large amount of energy of the sub-bands; and

a decoding unit configured to perform sinusoidal decoding with regard to the selected sub-bands.

14. The apparatus of claim 13, wherein the decoding unit selects the selected sub-bands as a search track for the sinusoidal decoding based on the amount of energy of the sub-bands, and performs the sinusoidal decoding with regard to the search track.

15. The apparatus of claim 14, wherein the decoding unit selects adjacent sub-bands among the selected sub-bands as one search track.

16. The apparatus of claim 13, wherein the decoding unit merges adjacent sub-bands among the selected sub-bands into one sub-band, and performs the sinusoidal decoding with regard to the merged sub-band.