Audio signal processing method and device

Patent metadata

Field	Value
Publication number	US-9986365-B2
Application number	US-201715825078-A
Country	US
Kind code	B2
Filing date	Nov 28, 2017
Priority date	Apr 2, 2014
Publication date	May 29, 2018
Grant date	May 29, 2018

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.

First claim

What is claimed is:

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.

Assignees

• Wilus Inst Standards & Tech Inc

Inventors

• Lee Taegyu
• Oh hyun oh

Classifications

• H04S7/306

  For headphones · CPC title

• H04S2400/11

  Positioning of individual sound objects, e.g. moving airplane, within a sound field (H04S2420/13 takes precedence) · CPC title

• H04S3/008 Primary

  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 title

• H04S2400/03

  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 title

• H04S2420/01

  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 title