KR20170059135A

KR20170059135A - High-Quality 3D Audio Generation Method and System

Info

Publication number: KR20170059135A
Application number: KR1020150163039A
Authority: KR
Inventors: 이영한; 조충상; 김제우; 김용환
Original assignee: 전자부품연구원
Priority date: 2015-11-20
Filing date: 2015-11-20
Publication date: 2017-05-30

Abstract

A method and system for producing high quality 3D audio is provided. A 3D audio generating method according to an embodiment of the present invention processes an audio original sound through one of a first channel and a second channel and processes the filtered audio original sound through the other channel. Thus, filtering is not performed in both channels, and sound quality improvement can be expected in providing 3D audio.

Description

TECHNICAL FIELD [0001] The present invention relates to a high-quality 3D audio generation method and system,

The present invention relates to audio technology, and more particularly, to a method and system for generating high quality 3D audio.

The HRTF (Head-Related Transfer Function) used in 3D audio is to measure the difference between the left and right audio signals to create an impulse response and apply it to the audio signal to generate a 3D audio effect.

FIG. 1 is a view showing the principle of conventional 3D audio. As shown in Fig. 1, in the 3D audio, what is transmitted from the sound source S to the ears is defined as filters.

That is, the source S can be seen that each converted to audio signals S _L × H, S H × _R of the left and right channel via the left and right filters H _L, H _R. As a result, the user can feel the difference between the channels, and the difference ultimately becomes the directionality.

Therefore, if H _L and H _R are known according to the angle of the sound source S, the direction of the sound source S can be added through the filtering process as shown in FIG. FIG. 2 is a diagram illustrating a 3D audio generation method based on HRTF.

However, since filtering is performed on both of the left and right channels, sound quality deterioration occurs in both the left and right channels. In particular, since the characteristics of the HRTF measurement space are applied to the audio generation, it is significantly different from the original sound.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a high quality 3D audio generating method and system capable of minimizing sound quality deterioration.

According to an aspect of the present invention, there is provided a 3D audio generating method including: a first processing step of processing audio original sound through one of a first channel and a second channel; And a second processing step of causing the filtered audio original sound to be output through another one of the first channel and the second channel.

In the first processing step, the audio source sound is output through a channel having a short sound source distance among the first channel and the second channel.

In addition, the first processing step may not filter the audio original sound.

According to another aspect of the present invention, there is provided a 3D audio generating method comprising: changing a channel on which audio original sound is output and a channel on which a filtered audio original sound is to be output, when a channel having a short sound source distance is changed due to movement of a sound source; As shown in FIG.

Further, the filtering may use HRTF components made up of the HRTF component for the first channel and the HRTF component for the second channel.

According to another aspect of the present invention, there is provided a 3D audio generation system including: And an audio processor for processing the audio original sound to be output through one of the first channel and the second channel and processing the audio original sound filtered through the other of the first channel and the second channel to be output.

As described above, according to the embodiments of the present invention, filtering is not performed in both channels, and sound quality improvement can be expected in providing 3D audio.

In addition, according to the embodiments of the present invention, since only one channel is subjected to filtering, directional audio can be provided using a minimum amount of calculation and a memory.

FIG. 1 is a diagram illustrating the principle of conventional 3D audio,
2 is a diagram illustrating a 3D audio generation method based on HRTF,
FIG. 3 is a block diagram illustrating the principle of 3D audio generation according to an embodiment of the present invention.
FIG. 4 is a block diagram illustrating a method of generating 3D audio according to an exemplary embodiment of the present invention.
5 is a block diagram of a 3D audio generation system according to an embodiment of the present invention;
6 is a flowchart provided for explanation of the 3D audio generation process by the audio processor 120,
FIG. 7 shows the original sound for the case where the sound source is located on the right side,
FIG. 8 is a diagram illustrating 3D audio generated according to a conventional method,
9 is a spectrogram of 3D audio generated by a method according to an embodiment of the present invention.

Hereinafter, the present invention will be described in detail with reference to the drawings.

3D audio basically recognizes directions, distances, etc. by using difference of signals acquired from both ears.

It is a method to improve the disadvantage that the sound quality of 3D audio is deteriorated compared to the original sound due to the characteristics of the HRTF measurement space as well as the direction which can be felt by the ear when HRTF (Head-Related Transfer Function) is applied In the embodiment of the present invention, 3D audio is generated so that original sound is output from one ear.

That is, in the embodiment of the present invention, the difference between the filtering of one channel, that is, the difference of the impulse response between left and right channels is applied to only one channel, rather than filtering all channels.

FIG. 3 is a diagram provided in the explanation of the principle of 3D audio generation according to the embodiment of the present invention. In Fig. 3, it is assumed that the sound source is located close to the left ear. That is, it is assumed that the sound source distance of the left channel is shorter than the sound source distance of the right channel.

For high quality 3D audio generation, as shown in FIG. 3,

. Then, the audio signals of the left and right channels through H _L , H _R are S,

. That is,

Is positioned at a specific position.

FIG. 4 is a diagram illustrating a 3D audio generation method according to an embodiment of the present invention. 4, in the 3D audio generation method according to the embodiment of the present invention, the original sound S is provided to the left channel, and the ratio of the left HRTF component to the right HRTF component

).

This can be seen as a 3D audio generation method that does not perform filtering on both channels by composing a set of Impulse responses in the right and left and generating one impulse response.

The 3D audio generated according to the method shown in FIG. 4 has similar directionality to the 3D audio generated according to the conventional method, and the sound quality is improved. This is because the original sound is output from the channel close to the sound source.

Also, since the filtering process is reduced to one channel unlike the conventional method in which the filtering is performed for two channels, the amount of calculation for the memory storing the filter coefficients and the filtering process is reduced to half.

5 is a block diagram of a 3D audio generation system according to an embodiment of the present invention. The 3D audio generating system according to the embodiment of the present invention includes an audio providing unit 110, an audio processor 120, and audio output units 130-L, R, as shown in FIG.

The audio data providing unit 110 may be implemented by a microphone for acquiring an audio source sound, a storage medium for storing an audio source sound, and a communication unit for receiving an audio source sound from an external device or an external network.

The audio processor 120 generates 3D audio from the audio sound provided by the audio data providing unit 110. [ The 3D audio generation process by the audio processor 120 will be described later in detail with reference to FIG.

The audio output units 130-L and 130-L are means for outputting the 3D audio generated by the audio processor 120. In the audio output unit-L 130-L, And audio of the right channel is output in the audio channel 130-R.

FIG. 6 is a flowchart provided for explanation of the 3D audio generation process by the audio processor 120. FIG.

6, when an audio original sound is input from the audio data providing unit 110 to the audio processor 120 in step S210, the audio processor 120 determines a sound source distance in step S220.

In step S220, the source distance can be grasped not only by analyzing the sound source, but also by the input / setting contents of the 3D audio producer.

Next, the audio processor 120 generates 3D audio (S230, S240) such that the original sound is output for the channel whose sound source distance is short, and the filtered original sound is output for the channel whose sound source distance is long.

Steps S210 to S240 are repeated until 3D audio generation is completed (S250). In this process, when a change occurs in a channel having a short sound source distance due to the movement of the sound source, the channel to which the audio original sound is output and the channel to which the filtered audio original sound is output are changed.

The 3D audio quality enhancement according to the 3D audio generation method according to the embodiment of the present invention will be verified with reference to FIGS. 7 to 9. FIG.

FIG. 7 is an original sound when a sound source is located on the right side, FIG. 8 is 3D audio generated according to a conventional method, and FIG. 9 is a spectrogram of 3D audio generated by the method according to an embodiment of the present invention.

As can be seen from a comparison with the spectrogram of the original sound shown in FIG. 7, the conventional method shown in FIG. 8 shows that both channels of the original sound are modified, whereas the method according to the embodiment of FIG. Is the same as the original sound, and it can be confirmed that only one channel is modified.

Up to now, preferred embodiments have been described in detail for high quality 3D audio generation methods and systems.

In order to improve the disadvantage that the sound quality of the 3D audio is deteriorated compared to the original sound due to the characteristic of the HRTF measurement space as well as the direction that the ear can feel when the HRTF is applied, In one ear, 3D audio was generated to output the original sound.

That is, in the embodiment of the present invention, the difference between the filtering of one channel, that is, the difference of the impulse response between left and right channels is applied to only one channel, not the filtering of both channels.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the present invention.

110: Audio Offering
120: audio processor
130-L: Audio output section-L
130-R: Audio output section -R

Claims

A first processing step of processing an audio original sound through one of a first channel and a second channel so as to be output; And
And a second processing step of processing the filtered audio original sound through another one of the first channel and the second channel to output the filtered audio original sound.

The method according to claim 1,
In the first processing step,
Wherein processing is performed such that audio original sound is output through a channel having a short sound source distance among the first channel and the second channel.

The method of claim 2,
In the first processing step,
Wherein the audio source sound is not filtered.

The method of claim 2,
And changing a channel on which audio original sound is to be output and a channel on which filtered audio original sound is to be output, when the channel having a short sound source distance is changed due to the movement of the sound source.

The method according to claim 1,
The filtering,
Wherein an HRTF component consisting of a ratio of an HRTF component to a first channel and an HRTF component to a second channel is used.

A providing unit for providing an audio original sound;
And an audio processor for processing the audio original sound to be outputted through one of the first channel and the second channel and for processing the audio original sound filtered through the other one of the first channel and the second channel to be outputted, 3D audio production system.