Audio signal processing method and device

• US 9,986,365 B2
• Filed: 11/28/2017
• Issued: 05/29/2018
• Est. Priority Date: 04/02/2014
• Status: Active Grant

• Current Assignee: GCOA Company Limited, Wilus Institute of Standards & Technology, Inc. (Good Day to Invent, Inc.)
• Original Assignee: Wilus Institute of Standards & Technology, Inc. (Good Day to Invent, Inc.)
• Inventors: Lee, Taegyu, Oh, Hyun Oh
• Primary Examiner(s): HUBER, PAUL W
• Application Number:
  US15/825,078
• Publication Number:
  US 20180091927A1
• Time in Patent Office: 182 Days
• Field of Search: None
• 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 19/167 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: H04R 2430/03 Synergistic effects of band splitting and sub-band processing
• CPC Class Codes: H04R 2499/11 Transducers incorporated or for use in hand-held devices, e.g. mobile phones, PDA's, camera's
• CPC Class Codes: H04R 2499/15 Transducers incorporated in visual displaying devices, e.g. televisions, computer displays, laptops
• CPC Class Codes: H04R 3/04 for correcting frequency response
• 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 2400/03 Aspects of down-mixing multi-channel audio to configurations with lower numbers of playback channels, e.g. 7.1 -> 5.1 H04S2400/01 takes precedence
• 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 2420/01 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 2420/07 Synergistic effects of band splitting and sub-band processing
• 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 7/303 Tracking of listener position or orientation
• CPC Class Codes: H04S 7/306 For headphones
• CPC Class Codes: H04S 7/307 Frequency adjustment, e.g. tone control H04S7/301 takes precedence

Abstract

The present invention relates to a method and an apparatus for processing an audio signal, and more particularly, to a method and an apparatus for processing an audio signal, which synthesizes an object signal and a channel signal and effectively binaural-render the synthesized signal.

To this end, the present invention provides a method for processing an audio signal, including: receiving an input audio signal including at least one of a multi-channel signal and a multi-object signal; receiving type information of a filter set for binaural filtering of the input audio signal, the type of the filter set being one of a finite impulse response (FIR) filter, a parameterized filter in a frequency domain, and a parameterized filter in a time domain; receiving filter information for binaural filtering based on the type information; and performing the binaural filtering for the input audio signal by using the received filter information, wherein when the type information indicates the parameterized filter in the frequency domain, in the receiving of the filter information, a subband filter coefficient having a length determined for each subband of a frequency domain is received, and in the performing of the binaural filtering, each subband signal of the input audio signal is filtered by using the subband filter coefficient corresponding thereto and an apparatus for processing an audio signal by using the same.

Claims

1. A method for generating a filter for an audio signal, comprising:

receiving time domain binaural room impulse response (BRIR) filter coefficients for binaural filtering an input audio signal;

obtaining propagation time information of the time domain BRIR filter coefficients, the propagation time information representing a time from an initial sample to direct sound of the BRIR filter coefficients;

QMF-converting time domain BRIR filter coefficients subsequent to the obtained propagation time to generate a plurality of sets of subband filter coefficients;

obtaining filter order information for determining a truncation length of each set of subband filter coefficients by at least partially using characteristic information extracted from the set of subband filter coefficients, the filter order being variably determined in a frequency domain; and

truncating each set of subband filter coefficients based on the obtained filter order information for each subband.

2. The method of claim 1, wherein the obtaining the propagation time information further comprises:

measuring frame energies by shifting a predetermined hop wise;

identifying a first frame in which a frame energy is larger than a predetermined threshold; and

obtaining the propagation time information based on position information of the identified first frame.

3. The method of claim 2, wherein the measuring frame energies measures an average value of frame energies for each channel with respect to a same time interval.

4. The method of claim 2, wherein the threshold is determined to be a value which is lower than a maximum value of the measured frame energy by a predetermined proportion.

5. The method of claim 1, wherein the characteristic information comprises reverberation time information of the corresponding set of subband filter coefficients, and the filter order has a single value for each subband.

6. A parameterization device for generating a filter for an audio signal, the parameterization device configured to:

receive time domain binaural room impulse response (BRIR) filter coefficients for binaural filtering an input audio signal;

obtain propagation time information of the time domain BRIR filter coefficients, the propagation time information representing a time from an initial sample to direct sound of the BRIR filter coefficients;

QMF-convert time domain BRIR filter coefficients subsequent to the obtained propagation time to generate a plurality of sets of subband filter coefficients;

obtain filter order information for determining a truncation length of each set of subband filter coefficients by at least partially using characteristic information extracted from the set of subband filter coefficients, the filter order being variably determined in a frequency domain; and

truncate each set of subband filter coefficients based on the obtained filter order information for each subband.

7. The device of claim 6, wherein the parameterization device is further configured to:

measure frame energies by shifting a predetermined hop wise;

identify a first frame in which a frame energy is larger than a predetermined threshold; and

obtain the propagation time information based on position information of the identified first frame.

8. The device of claim 7, wherein the parameterization device measures an average value of frame energies for each channel with respect to a same time interval.

9. The device of claim 7, wherein the threshold is determined to be a value which is lower than a maximum value of the measured frame energies by a predetermined proportion.

10. The device of claim 6, wherein the characteristic information comprises reverberation time information of the corresponding set of subband filter coefficients, and the filter order has a single value for each subband.