Virtual Stereo Synthesis Method and Apparatus

Patent metadata

Field	Value
Publication number	US-2016241986-A1
Application number	US-201615137493-A
Country	US
Kind code	A1
Filing date	Apr 25, 2016
Priority date	Oct 24, 2013
Publication date	Aug 18, 2016
Grant date	—

Abstract

A virtual stereo synthesis method includes acquiring at least one sound input signal on a first side and at least one sound input signal on a second side, separately performing ratio processing on a preset head related transfer function (HRTF) left-ear component and a preset HRTF right-ear component of each sound input signal on the second side, to obtain a filtering function of each sound input signal on the second side, separately performing convolution filtering on each sound input signal on the second side and the filtering function of the sound input signal on the second side, to obtain the filtered signal on the second side, and synthesizing all of the sound input signals on the first side and all of the filtered signals on the second side into a virtual stereo signal where the method may alleviate a coloration effect, and reduce calculation complexity.

First claim

What is claimed is:

1 . A virtual stereo synthesis method, comprising:
acquiring at least one sound input signal on a first side and at least one sound input signal on a second side; separately performing ratio processing on a preset head related transfer function (HRTF) left-ear component and a preset HRTF right-ear component of each sound input signal on the second side, to obtain a filtering function of each sound input signal on the second side; separately performing convolution filtering on each sound input signal on the second side and the filtering function of the sound input signal on the second side, to obtain a filtered signal on the second side; and synthesizing all of the sound input signals on the first side and all of the filtered signals on the second side into a virtual stereo signal.

2 . The method according to claim 1 , wherein separately performing the ratio processing on the preset HRTF left-ear component and the preset HRTF right-ear component of each sound input signal on the second side, to obtain the filtering function of each sound input signal on the second side comprises:
separately using a ratio of a left-ear frequency domain parameter to a right-ear frequency domain parameter of each sound input signal on the second side as a frequency-domain filtering function of each sound input signal on the second side, wherein the left-ear frequency domain parameter indicates the preset HRTF left-ear component of the sound input signal on the second side, and wherein the right-ear frequency domain parameter indicates the preset HRTF right-ear component of the sound input signal on the second side; separately transforming the frequency-domain filtering function of each sound input signal on the second side to a time-domain function; and using the time-domain function as the filtering function of each sound input signal on the second side.

3 . The method according to claim 2 , wherein separately transforming the frequency-domain filtering function of each sound input signal on the second side to the time-domain function, and using the time-domain function as the filtering function of each sound input signal on the second side comprises:
separately performing minimum phase filtering on the frequency-domain filtering function of each sound input signal on the second side; transforming the frequency-domain filtering function to the time-domain function; and using the time-domain function as the filtering function of each sound input signal on the second side.

4 . The method according to claim 2 , wherein before separately using the ratio of the left-ear frequency domain parameter to the right-ear frequency domain parameter of each sound input signal on the second side as the frequency-domain filtering function of each sound input signal on the second side, the method further comprises:
separately using a frequency domain of the preset HRTF left-ear component of each sound input signal on the second side as the left-ear frequency domain parameter of each sound input signal on the second side, and separately using a frequency domain of the preset HRTF right-ear component of each sound input signal on the second side as the right-ear frequency domain parameter of each sound input signal on the second side; or separately using a frequency domain of the preset HRTF left-ear component of each sound input signal on the second side as the left-ear frequency domain parameter of each sound input signal on the second side after diffuse-field equalization or subband smoothing, and separately using the frequency domain of the preset HRTF right-ear component of each sound input signal on the second side as the right-ear frequency domain parameter of each sound input signal on the second side after the diffuse-field equalization or the subband smoothing; or separately using the frequency domain of the preset HRTF left-ear component of each sound input signal on the second side as the left-ear frequency domain parameter of each sound input signal on the second side after diffuse-field equalization and subband smoothing is performed in sequence, and separately using the frequency domain of the preset HRTF right-ear component of each sound input signal on the second side as the right-ear frequency domain parameter of each sound input signal on the second side after diffuse-field equalization and subband smoothing is performed in sequence.

5 . The method according to claim 1 , wherein separately performing convolution filtering on each sound input signal on the second side and the filtering function of the sound input signal on the second side, to obtain the filtered signal on the second side comprises:
separately performing reverberation processing on each sound input signal on the second side; using the processed signal as a sound reverberation signal on the second side; and separately performing convolution filtering on each sound reverberation signal on the second side and the filtering function of the corresponding sound input signal on the second side, to obtain the filtered signal on the second side.

6 . The method according to claim 5 , wherein separately performing the reverberation processing on each sound input signal on the second side, and using the processed signal as the sound reverberation signal on the second side comprises:
separately passing each sound input signal on the second side through an all-pass filter, to obtain a reverberation signal of each sound input signal on the second side; and separately synthesizing each sound input signal on the second side and the reverberation signal of the sound input signal on the second side into the sound reverberation signal on the second side.

7 . The method according to claim 1 , wherein synthesizing all of the sound input signals on the first side and all of the filtered signals on the second side into the virtual stereo signal comprises:
summating all of the sound input signals on the first side and all of the filtered signals on the second side to obtain a synthetic signal; performing, using a fourth-order infinite impulse response (IIR) filter, timbre equalization on the synthetic signal; and using the timbre-equalized synthetic signal as the virtual stereo signal.

8 . A virtual stereo synthesis apparatus, comprising:
a memory; and a processor coupled to the memory, wherein the processor is configured to:
acquire at least one sound input signal on a first side and at least one sound input signal on a second side;
separately perform ratio processing on a preset head related transfer function (HRTF) left-ear component and a preset HRTF right-ear component of each sound input signal on the second side, to obtain a filtering function of each sound input signal on the second side;
separately perform convolution filtering on each sound input signal on the second side and the filtering function of the sound input signal on the second side, to obtain a filtered signal on the second side; and
synthesize all of the sound input signals on the first side and all of the filtered signals on the second side into a virtual stereo signal.

9 . The apparatus according to claim 8 , wherein the processor is further configured to:
separately use a ratio of a left-ear frequency domain parameter to a right-ear frequency domain parameter of each sound input signal on the second side as a frequency-domain filtering function of each sound input signal on the second side, wherein the left-ear frequency domain parameter indicates the preset HRTF left-ear component of the sound input signal on the second side, and wherein the right-ear frequency domain parameter indicates the preset HRTF right-ear component of the sound input signal on the second side; sep

Assignees

• Huawei Tech Co Ltd

Inventors

• Lang Yue
• Du Zhengzhong

Classifications

• H04S3/004 Primary

  For headphones · CPC title

• H04S1/005

  For headphones · CPC title

• H04S1/002

  Non-adaptive circuits, e.g. manually adjustable or static, for enhancing the sound image or the spatial distribution (control circuits for electronic adaptation of the sound field H04S7/30) · CPC title

• H04S2400/11

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

• H04R5/033

  Headphones for stereophonic communication {(details thereof, e.g. relating to batteries, cables or control elements H04R1/10)} · CPC title