APPARATUS FOR PROCESSING AN AUDIO SIGNAL AND METHOD THEREOF

• US 20100114585A1
• Filed: 11/04/2009
• Published: 05/06/2010
• Est. Priority Date: 11/04/2008
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: KIM, Dong Soo, LEE, Hyun Kook, YOON, Sung Yong, LIM, Jae Hyun
• Granted Patent: US 8,364,471 B2
• Time in Patent Office: Days
• US Class Current: 704/500
• CPC Class Codes: G10L 19/028 Noise substitution, i.e. substituting non-tonal spectral components by noisy source comfort noise for discontinuous speech transmission G10L19/012
• CPC Class Codes: G10L 19/035 Scalar quantisation
• CPC Class Codes: G10L 19/167 Audio streaming, i.e. formatting and decoding of an encoded audio signal representation into a data stream for transmission or storage purposes
• CPC Class Codes: G10L 21/038 using band spreading techniques

Abstract

An apparatus for processing an audio signal and method thereof are disclosed, by which a method for processing an audio signal, comprising: extracting noise filling flag information indicating whether noise filling is used to a plurality of frames; extracting coding scheme information indicating whether a current frame included in the plurality of frames is coded in either a frequency domain or a time domain; when the noise filling flag information indicates that the noise filling is used to for the plurality of frames and the coding scheme information indicates that the current frame is coded in the frequency domain, extracting noise level information for the current frame; when a noise level value corresponding to the noise level information meets a predetermined level, extracting noise offset information for the current frame; and, when the noise offset information is extracted, performs the noise-filling for the current frame based on the noise level value and the noise offset information.

Claims

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

extracting noise filling flag information indicating whether noise filling is used to a plurality of frames;

extracting coding scheme information indicating whether a current frame included in the plurality of frames is coded in either a frequency domain or a time domain;

when the noise filling flag information indicates that the noise filling is used to for the plurality of frames and the coding scheme information indicates that the current frame is coded in the frequency domain, extracting noise level information for the current frame;

when a noise level value corresponding to the noise level information meets a predetermined level, extracting noise offset information for the current frame; and

,

when the noise offset information is extracted, performs the noise-filling for the current frame based on the noise level value and the noise offset information.

2. The method of claim 1, wherein the noise-filling comprises:

determining a loss area of the current frame using a spectral data of the current frame;

generating a compensated spectral data by filling the loss area with a compensation signal using the noise level value; and

generating a compensated scalefactor based on the noise offset information.

3. The method of claim 1, further comprising:

extracting a level pilot value representing a reference value of a noise level, and an offset pilot value representing a reference value of a noise offset;

obtaining the noise level value by summing the level pilot value and the noise level information; and

,

when the noise offset information is extracted, obtaining a noise offset value by summing the offset pilot value and the noise offset information,

wherein the noise filling is performed using the noise level value and the noise offset value.

4. The method of claim 1, further comprising:

obtaining a noise level value of the current frame using a noise level value of a previous frame and the noise level information of the current frame; and

,

when the noise offset information is extracted, obtaining a noise offset value of the current frame using a noise offset value of the previous frame and the noise offset information of the current frame,

wherein the noise filling is performed using the noise level value and the noise offset value.

5. The method of claim 1, wherein both the noise level information and the noise offset information are extracted according to variable length coding scheme.

6. An apparatus for processing an audio signal, comprising:

a multiplexer extracting noise filling flag information indicating whether noise filling is used to a plurality of frames, and coding scheme information indicating whether a current frame included in the plurality of frames is coded in either a frequency domain or a time domain;

a noise information decoding part, when the noise filling flag information indicates that the noise filling is used to for the plurality of frames and the coding scheme information indicates that the current frame is coded in the frequency domain, extracting noise level information for the current frame, and when a noise level value corresponding to the noise level information meets a predetermined level, extracting noise offset information for the current frame; and

,

a loss compensation part, when the noise offset information is extracted, performs the noise-filling for the current frame based on the noise level value and the noise offset information.

7. The apparatus of claim 6, wherein the loss compensation part configured to:

determines a loss area of the current frame using a spectral data of the current frame,

generate a compensated spectral data by filling the loss area with a compensation signal using the noise level value, and

generate a compensated scalefactor based on the noise offset information.

8. The apparatus of claim 6, further comprising:

a data decoding part configured to;

extract a level pilot value representing a reference value of a noise level, and an offset pilot value representing a reference value of a noise offset,

obtain the noise level value by summing the level pilot value and the noise level information, and,

when the noise offset information is extracted, obtain a noise offset value by summing the offset pilot value and the noise offset information,

wherein the noise filling is performed using the noise level value and the noise offset value.

9. The apparatus of claim 6, further comprising:

a data decoding part configured to;

obtain a noise level value of the current frame using a noise level value of a previous frame and the noise level information of the current frame, and,

when the noise offset information is extracted, obtain a noise offset value of the current frame using a noise offset value of the previous frame and the noise offset information of the current frame,

wherein the noise filling is performed using the noise level value and the noise offset value.

10. The apparatus of claim 6, wherein both the noise level information and the noise offset information are extracted according to variable length coding scheme.

11. A method for processing an audio signal, comprising:

generating a noise level value and a noise offset value based on a quantized signal;

generating noise filling flag information indicating whether noise filling is used to a plurality of frames;

generating coding scheme information indicating whether a current frame included in the plurality of frames is coded in either a frequency domain or a time domain;

when the noise filling flag information indicates that the noise filling is used to for the plurality of frames and the coding scheme information indicates that the current frame is coded in the frequency domain, inserting noise level information for the current frame corresponding to the noise level value into a bitstream; and

,

when the noise level value meets a predetermined level, inserting noise offset information corresponding to the noise offset value into the bitstream.

12. An apparatus for processing an audio signal, comprising:

a loss compensation estimating part generating a noise level value and a noise offset value based on a quantized signal, and noise filling flag information indicating whether noise filling is used to a plurality of frames;

a signal classifier generating coding scheme information indicating whether a current frame included in the plurality of frames is coded in either a frequency domain or a time domain; and

,

a noise information encoding part, when the noise filling flag information indicates that the noise filling is used to for the plurality of frames and the coding scheme information indicates that the current domain is coded in the frequency domain, inserting noise level information for the current frame corresponding to the noise level value into a bitstream; and

, when the noise level value meets a predetermined level, inserting noise offset information corresponding to the noise offset value into the bitstream.

13. A computer-readable medium having instructions stored thereon, which, when executed by a processor, causes the processor to perform operations, comprising:

extracting noise filling flag information indicating whether noise filling is used to a plurality of frames;

extracting coding scheme information indicating whether a current frame included in the plurality of frames is coded in either a frequency domain or a time domain;

when the noise filling flag information indicates that the noise filling is used to for the plurality of frames and the coding scheme information indicates that the current frame is coded in the frequency domain, extracting noise level information for the current frame;

when a noise level value corresponding to the noise level information meets a predetermined level, extracting noise offset information for the current frame; and

,

when the noise offset information is extracted, performs the noise-filling for the current frame based on the noise level value and the noise offset information.