APPARATUS AND METHOD FOR SEPARATING MULTI-CHANNEL AUDIO SIGNAL

• US 20150063574A1
• Filed: 08/29/2014
• Published: 03/05/2015
• Est. Priority Date: 08/30/2013
• Status: Abandoned Application

• Current Assignee: Electronics and Telecommunications Research Institute
• Original Assignee: Electronics and Telecommunications Research Institute
• Inventors: PARK, Tae Jin, YOO, Jae Hyoun, SEO, Jeong Il, JANG, Dae Young, KANG, Kyeong Ok, KIM, Jin Woong, CHOI, Keunwoo
• Application Number:
  US14/472,634
• Publication Number:
  US 20150063574A1
• Time in Patent Office: Days
• US Class Current: 381/18
• CPC Class Codes: H04S 2400/01 Multi-channel, i.e. more than two input channels, sound reproduction with two speakers wherein the multi-channel information is substantially preserved
• CPC Class Codes: H04S 2400/11 Positioning of individual sound objects, e.g. moving airplane, within a sound field H04S2420/13 takes precedence
• CPC Class Codes: H04S 2420/07 Synergistic effects of band splitting and sub-band processing
• CPC Class Codes: H04S 3/02 of the matrix type, i.e. in which input signals are combined algebraically, e.g. after having been phase shifted with respect to each other
• CPC Class Codes: H04S 5/00 Pseudo-stereo systems, e.g. in which additional channel signals are derived from monophonic signals by means of phase shifting, time delay or reverberation

Abstract

An apparatus and method for separating a multi-channel audio signal that separates a multi-channel audio signal into a plurality of sound source objects is disclosed, the apparatus including a multi-channel stereo transformer to transform a multi-channel audio signal into a plurality of stereo signals, and a stereo sound source separator to separate the plurality of stereo signals into a plurality of sound source objects.

Claims

1. An apparatus for separating a multi-channel audio signal, the apparatus comprising:

a multi-channel-stereo transformer to transform a multi-channel audio signal into a plurality of stereo signals; and

a stereo sound source separator to separate the plurality of stereo signals into a plurality of sound source objects.

2. The apparatus of claim 1, wherein the multi-channel-stereo transformer transforms the multi-channel audio signal into a signal of a time-frequency region, and transforms the multi-channel audio signal into the plurality of stereo signals through use of a cross correlation coefficient of a time-frequency (TF) bin.

3. The apparatus of claim 2, wherein the multi-channel-stereo transformer determines a mask to be applied to the multi-channel audio signal transformed into the time-frequency region based on the cross correlation coefficient, and generates a stereo signal through use of the determined mask.

4. The apparatus of claim 1, wherein the multi-channel-stereo transformer determines a “

K”

number of stereo signals to be output based on Equation 3 when a multi-channel audio signal having an “

N”

number of channels is input,

where

5. The apparatus of claim 1, wherein the multi-channel-stereo transformer comprises:

a time-frequency transformer to transform the multi-channel audio signal into a time-frequency region;

a cross correlation coefficient calculator to calculate a cross correlation coefficient of a TF bin in the multi-channel audio signal transformed into the time-frequency region;

a mask determiner to determine a mask to be applied to the multi-channel audio signal transformed into the time-frequency region based on the cross correlation coefficient; and

a stereo signal generator to generate a stereo signal through use of the mask.

6. The apparatus of claim 1, wherein the cross correlation coefficient calculator calculates a cross correlation coefficient through use of a forgetting factor for reflecting a temporal change and the TF bin.

7. The apparatus of claim 5, wherein the mask determiner compares cross correlation coefficients of an audio channel pair, and determines an audio channel pair to which the TF bin belongs.

8. The apparatus of claim 5, wherein the mask determiner sets a value of a mask corresponding to a greatest cross correlation coefficient to “

1”

, and sets a value of a mask corresponding to other cross correlation coefficients to “

0”

from among cross correlation coefficients of an audio channel pair including a predetermined channel.

9. The apparatus of claim 5, wherein the mask determiner sets a value of a mask to a continuous value between “

0” and

“

1”

based on a size of the cross correlation coefficients of the audio channel pair including the predetermined channel.

10. The apparatus of claim 5, wherein the stereo signal generator generates a stereo signal through use of the TF bin of the multi-channel audio signal transformed into the time-frequency signal and a mask corresponding to the TF bin.

11. A method of separating a multi-channel audio signal, the method comprising:

transforming a multi-channel audio signal into a plurality of stereo signals; and

separating the plurality of stereo signals into a plurality of sound source objects.

12. The method of claim 11, wherein the transforming comprises:

transforming the multi-channel audio signal into a signal of a time-frequency region; and

transforming the multi-channel audio signal into the plurality of stereo signals through use of a cross correlation coefficient of a time-frequency (TF) bin.

13. The method of claim 12, wherein the transforming comprises:

determining a mask to be applied to the multi-channel audio signal transformed into the signal of the time-frequency region based on the cross correlation coefficient; and

generating a stereo signal through use of the determined mask.

14. The method of claim 11, wherein the transforming comprises:

transforming the multi-channel audio signal into the signal of the time-frequency region;

calculating a cross correlation coefficient of the TF bin in the multi-channel audio signal transformed into the signal of the time-frequency region;

determining a mask to be applied to the multi-channel audio signal transformed into the signal of the time-frequency region based on the cross correlation coefficient; and

generating a stereo signal through use of the mask.

15. The method of claim 14, wherein the calculating of the cross correlation coefficient comprises:

calculating the cross correlation coefficient through use of a forgetting factor for reflecting a temporal change and the TF bin.

16. The method of claim 14, wherein the determining of the mask comprises:

setting a value of a mask corresponding to a greatest cross correlation coefficient to “

1”

, and setting a value of a mask corresponding to other cross correlation coefficients to “

0”

from among cross correlation coefficients of an audio channel pair including a predetermined channel.

17. The method of claim 14, wherein the determining of the mask comprises:

setting a value of a mask to a continuous value between “

0” and

“

1”

based on a size of the cross correlation coefficients of the audio channel pair including the predetermined channel.

18. The method of claim 14, wherein the generating of the stereo signal comprises:

generating a stereo signal through use of the TF bin of the multi-channel audio signal transformed into the signal of the time-frequency region and a mask corresponding to the TF bin.