Method and an apparatus for decoding an audio signal

• US 7,783,051 B2
• Filed: 10/02/2009
• Issued: 08/24/2010
• Est. Priority Date: 12/07/2006
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Oh, Hyen-O, Jung, Yang-Won
• Primary Examiner(s): Chin; Vivian
• Assistant Examiner(s): Kurr; Jason R
• Application Number:
  US12/573,067
• Publication Number:
  US 20100014680A1
• Time in Patent Office: 326 Days
• Field of Search: 700/94, 704/500, 704/504, 381/22, 381/23, 381/2, 381/119, 381 17- 19, 386/54, 386/96, 369/1, 369/4
• US Class Current: 381/22
• 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: H04S 2420/01 Enhancing the perception of the sound image or of the spatial distribution using head related transfer functions [HRTF's] or equivalents thereof, e.g. interaural time difference [ITD] or interaural level difference [ILD]
• CPC Class Codes: H04S 2420/03 Application of parametric coding in stereophonic audio systems
• CPC Class Codes: H04S 3/008 in which the audio signals are in digital form, i.e. employing more than two discrete digital channels data reduction aspects thereof based on psychoacoustics G10L19/02
• CPC Class Codes: H04S 7/302 Electronic adaptation of stereophonic sound system to listener position or orientation H04S7/301 takes precedence

Abstract

A method for processing an audio signal, comprising: receiving a downmix signal, an object information, and a mix information; generating a multi-channel information including at least one gain modification factor using the object information and the mix information, wherein the gain modification factor corresponds to a time-subband-variant factor for controlling gain of the downmix signal is disclosed.

Claims

1. A method for decoding an audio signal performed by an audio coding system, comprising:

receiving a downmix signal comprising at least one object signal;

receiving object information determined when the downmix signal is generated;

receiving mix information for controlling the at least one object signal;

bypassing processing the downmix signal using downmix processing information if the downmix signal corresponds to a mono signal; and

generating multi-channel information including at least one gain modification factor using the object information and the mix information if the downmix signal corresponds to the mono signal,

wherein;

the gain modification factor corresponds to a time-subband-variant factor for controlling gain of the downmix signal;

the gain modification factor is used to modify a gain of the downmix signal;

the downmix processing information is estimated based on the object information and the mix information;

the object information includes at least one of object level information and object correlation information;

the multi-channel information includes at least one of a channel level difference, an inter channel correlation, and a channel prediction coefficient;

the downmix signal corresponds to the mono signal or a stereo signal;

the multi-channel information is used to generate a multi-channel signal using the downmix signal; and

a number of channels of the multi-channel signal is more than a number of channels of the downmix signal.

2. The method of claim 1, further comprising:

generating the downmix processing information using the object information and the mix information if the downmix signal corresponds to the stereo signal; and

processing the downmix signal using the downmix processing information to generate a processed downmix signal if the downmix signal corresponds to the stereo signal,

wherein the number of channels of the downmix signal is equal to a number of channels of the processed downmix signal.

3. The method of claim 1, wherein the gain modification factor describes a ratio of a first gain estimated based on the mix information and the object information over a second gain estimated based on the object information.

4. The method of claim 1, further comprising:

generating a multi-channel bitstream using the multi-channel information.

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

a downmix processing unit bypassing processing a downmix signal using downmix processing information if the downmix signal corresponds to a mono signal; and

,

an information generating unit receiving object information determined when the downmix signal is generated, receiving mix information for controlling at least one object signal, and generating multi-channel information including at least one gain modification factor using the object information and the mix information if the downmix signal comprising the at least one object signal corresponds to the mono signal,

wherein;

the gain modification factor corresponds to a time-subband-variant factor for controlling gain of the downmix signal;

the gain modification factor is used to modify a gain of the downmix signal;

the downmix processing information is estimated based on the object information and the mix information;

the object information includes at least one of object level information and object correlation information;

the multi-channel information includes at least one of a channel level difference, an inter channel correlation, and a channel prediction coefficient;

the downmix signal corresponds to the mono signal or a stereo signal;

the multi-channel information is used to generate a multi-channel signal using the downmix signal, and,

a number of channels of the multi-channel signal is more than a number of channels of the downmix signal.

6. The method of claim 5, wherein the information generating unit generates downmix processing information using the object information and the mix information if the downmix signal corresponds to a stereo signal;

and

the downmix processing unit processes the downmix signal using the downmix processing information to generate a processed downmix signal if the downmix signal corresponds to the stereo signal,

wherein the number of channels of the downmix signal is equal to a number of channels of the processed downmix signal.

7. The apparatus of claim 5, wherein the gain modification factor describes a ratio of a first gain estimated based on the mix information and the object information over a second gain estimated based on the object information.

8. The apparatus of claim 5, wherein the information generating unit generates a multi-channel bitstream using the multi-channel information.