JPH0479599A - Static variable acoustic signal recording and reproducing device - Google Patents

Abstract

PURPOSE:To always obtain the optimum static direction by decoding a direction signal and an audio signal from a digital sound format signal recorded on a recording medium, and computing the audio signal by the direction signal and the installing position coefficient of a speaker. CONSTITUTION:Information relating to the static direction of sound is inputted to direction input devices 2, 3 confirming to the audio signal. Thence, the direction signal and the audio signal outputted from the direction input device are encoded to digital sound formats by an encoder 6. An encoded digital sound format signal is recorded on the recording medium 7. The signals recorded on recording medium 7 are decoded to the direction signal and the audio signal again by a decoder 11, and the audio signal is computed by the direction signal and the installing position coefficient decided by the installing position of the speaker at an arithmetic unit 12 at every speaker, and is supplied to each speaker. Thereby, the optimum output signal can be obtained at a speaker position, and sound whose static direction matches with a recorded direction signal can be reproduced.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an audio recording and reproducing device that changes the localization direction of sound.

(Prior Art) As a current sound system, a stereo system using two-channel sound signals as shown in FIG. 5, for example, is known. According to this system, the right (hereinafter referred to as R) channel signal output from the player 41 is sent to the speaker R44 via the R channel signal line 42, and the left (hereinafter referred to as L) channel signal is sent to the L channel signal line. 43 to the speaker L45. According to this system, the direction in which sound can be localized is limited to a triangular plane connecting the two left and right speakers and the listener.

On the other hand, as more advanced sound systems, for example, U.S. Pat.
No. 59590, etc., using a two-channel acoustic signal, Dolby Stereo (registered trademark) or Dolby Surround (registered trademark), which localizes sound in various directions within a plane.
(registered trademark) method is disclosed.

In this Dolby stereo system, as shown in FIG. 6, the R and L channel signals output from the player 41 are sent to a 1.ruby stereo decoder 46 via signal lines 42 and 43, and this decoder 46 further sends the C channel signal. 47 and S channel signal 48 are generated, resulting in a total of 4 channel signals. The C and S channels are created by calculating the R and L channels as shown in the following equations.

C=L+R55=L-R Then, the four signals are compared, and the signal with a high level is increased, and the signal with a low level is further decreased. In this way, the four speakers 44, 45, 49 arranged around the listener transmit the four signals with the sound localization direction emphasized.
．． Play at 50.

In this way - localize the sound in various directions within the plane;

(Problems to be Solved by the Invention) With Dolby Stereo, the directions in which sound can be localized are limited to one plane.

In addition, only four channels' worth of signals can be obtained, and even if five or more speakers can be used, these speakers cannot be used effectively because it is not possible to supply more than four channels' worth of localized audio signals. .

Furthermore, the positions where these four speakers are placed depend on the conditions of the room, the preferences of the listeners, etc., and are not necessarily placed as intended by the producer. Therefore, depending on the position of the speaker, a sufficient localization effect may not be achieved. In addition, for the producer, the trackdown process required trial and error, including repeating encoding into two channels and checking the localization direction through trial listening.

(Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention provides a direction input device for inputting information related to the localization direction of sound, and a direction input device that inputs the input direction signal and audio signal in a digital audio format. an encoder that encodes a digital audio format signal, a recording medium that records this digital audio format signal, a decoder that decodes a direction signal and an audio signal from the digital audio format signal recorded on this recording medium, and an installation position of this direction signal and a speaker. and a calculation device that calculates this audio signal using coefficients.

(Operation) Information related to the localization direction of the sound is input to the direction input device in correspondence with the audio signal. Next, an encoder encodes the direction signal output from the direction input device and the audio signal into a digital audio format. This encoded digital audio format signal is recorded on a recording medium.

This recording medium is decoded again into a direction signal and an audio signal by a decoder. This audio signal is calculated for each speaker by a calculation device using the direction signal and an installation position coefficient determined by the installation position of the speaker, and is supplied to each speaker. As a result, an optimal output signal is obtained for that speaker position, and sound in the localized direction that matches the recorded direction signal is reproduced.

(Embodiment) FIG. 1 is a configuration diagram of a recording section of an embodiment according to the present invention, and
The figure is a configuration diagram of the playback section.

In FIG. 1, the recording unit 1- includes an input lever 2.3 for inputting the direction of sound in the L and R channels, an AD converter 4.5 for converting this direction signal from an analog signal to a digital signal, and an AD converter 4.5 for converting this direction signal from an analog signal to a digital signal. The encoder 6 receives direction signals via L and R channel direction signal lines 31, 32. Furthermore, the above and R channel audio signals are input to the encoder 6 via signal lines 33 and 34, respectively. Input lever 2.3 is front and rear, left and right.
One tab that allows you to set the sound localization in either direction.
You can independently set the direction of the L channel sound using the input lever 2, and the direction of the R channel sound using the input lever 3. Of course, by inputting the direction of the sound while moving the input lever 23, the direction of the sound can also be changed over time. Further, this setting may be made by inputting numerical values instead of using a lever. In this way, the direction signal and the audio signal are input to the encoder 6 via the signal lines 31, 32, 33, and 34. The encoder 6 encodes the direction signal and the audio signal according to a preset digital audio format. The digital audio format differs from conventional analog audio signals in that an area for recording additional information such as subcodes can be added separately from the audio signal.

Therefore, a direction signal is recorded in this subcode area.

The digital audio format signal encoded in this manner is sent to the recording medium 7 via the signal line 85.

This recording medium 7 includes video tapes, video discs,
There are audio tapes, audio discs, etc. still,
Since conventional recording and reproducing means are used, the explanation thereof will be omitted. Alternatively, the digital audio format signal may be sent using a wireless signal such as a broadcast radio wave instead of using such a recording medium.

In FIG. 2, the reproducing unit 10 includes a decoder 11 that inputs the output signal of the recording medium 7 via the signal line 36, and an arithmetic unit 12 that calculates the output signal of the decoder 11 and outputs it to each speaker. configured.

The decoder 11 converts the digital audio format signal into the above and R channel direction signals, and the above and R channel direction signals.
The channel audio signal is extracted and sent to the arithmetic unit 12. The calculation device 12 calculates an audio signal according to this direction signal. This calculation is to supply each speaker with the optimal output signal for each speaker's installation position and to achieve sound localization that matches the direction signal. Set for each speaker (1, calculated based on this coefficient. Therefore, when the position of the speaker is changed, the optimum localization direction can always be obtained by simply resetting this coefficient.

FIG. 3 is a diagram showing an example of the arrangement of speakers and listeners, and shows a case where one speaker is installed at each of the four corners. Of course 5
Similar calculations can be made with more than one machine. Further, to simplify the explanation, localization in one plane will be described, but localization in three dimensions can be similarly calculated.

A case will be explained in which the listener is located in the center of these speakers. Note that in order to represent the directions in a three-dimensional orthogonal coordinate system, the X axis is placed in front of the listener, the y axis is placed to the left of the listener, and the Z axis is placed above the listener.

First, the installation position coefficients of the four corner speakers are calculated. Taking the second speaker 20 on the left as an example, if the unit direction vector of the speaker as seen from the listener is Si, it is expressed as S i = (x, y, z) (r2/2.r2/2.O). be done. This numerical value is input using a direction vector input keyboard 29 connected to the outside of FIG. 2, and the input numerical value is written into the direction vector memory 13. The unit direction vector of the speaker may be input using a lever instead of the keyboard.

FIG. 4 is a diagram showing an example of the setting of the input lever 2.3, in which the localization direction of the L channel is set to the front direction, and the localization direction of the R channel is set to the rear direction.

Letting the direction vector of the L channel be DL and the direction vector of the 'RR channel be DR, then D, = (1,0,0) D, = (-1,O,O). The L and R channel direction signals are extracted by the decoder 11 shown in FIG. 2 and sent to the coefficient calculator 14. The coefficient calculator 14 retrieves the installation position coefficients calculated for each speaker from the direction vector memory 13 one by one, and multiplies this installation position coefficient by the L and R channel direction signals for each speaker.

That is, in FIG. 3, the L channel direction signal component of the speaker 20 is 2OL, and the R channel direction signal component is 2O.
When R is added, 2 OL = S i - D L = f 2 / 2
+ O+ 0=f2/2 20R-3i'DR" r2/2 〇ten〇=-"2/
It becomes 2. However, "・" represents the inner product of Bek) and Le.

In this case, when the vector becomes a negative number, all numbers are set to 0. That is, 2OR=O. This is to make the localization direction clearer by preventing the rear sound from being output from the front speakers. Similarly, all sounds from the front are set to 0 so that they are not output from the rear speakers. If the R channel direction signal component is calculated for speaker 2122.23 in this way, 21L=r2/2.21
R=0.22L=0, 22R=r2/2.23L=0.
23R=v=2/2.

In this way, L and R for each speaker
Once the direction signal component of the channel is calculated, the above and R channel audio signals corresponding to this direction signal component are:
The output calculators 15, 16, 17, and 18 shown in FIG. 2 perform calculations to obtain output signals for the respective speakers 20, 21, 22, and 23. These output signals are audio signals with direction signals added.

That is, in the output calculator 15, the output signal of the speaker 20=
It is calculated as 20LXLin+20RXRin=f2/2Lin. (1, in and Rin are L channel and R channel audio signals) Similarly, in the output calculator 16, the signal output of the speaker 21 = f 2 / 2 Li
n, in the output calculator 17, the signal output of the speaker 22 = r
2/2Rin.

The output calculator 18 calculates the signal output r2/2 of the speaker 23.
It is calculated as Rin.

By multiplying the direction signal component and the audio signal for each speaker in this way, it is possible to calculate and supply to each speaker an audio signal that realizes sound localization that matches the direction signal. Therefore, when changing the arrangement of the speakers or increasing or decreasing the number of speakers, the optimum localization direction can be obtained simply by resetting the direction vector of each speaker according to its placement location.

Also, since the localization direction can be input as a three-dimensional vector,
If the speaker is placed downward, vertical sound movement can also be reproduced.

In addition, if the signal recording medium has both an analog audio signal and a digital audio signal, the conventional Dolby stereo audio signal is recorded on the analog audio signal, and the localization variable sound according to the present invention is recorded on the digital audio signal. Signals can be recorded.

In this way, it is possible to support both playback using Dolby Stereo and playback according to the present invention.

As an example of the present invention, the case of audio equipment has been given, but of course it can be implemented in combination with video equipment, and when combined with video equipment, the effect of changing the sound localization according to the present invention is even more exhibited. Needless to say.

(Effects of the Invention) As described above, according to the present invention, the localization direction of sound can be arbitrarily set when recording an acoustic signal, a versatile digital audio format can be used as a medium, and,
When reproducing an acoustic signal, the optimum localization direction can always be obtained even if the number of speakers and their installation positions are changed.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of a recording section of an embodiment according to the present invention, and FIG.
3 is a diagram showing an example of the arrangement of speakers and listeners in the same embodiment. FIG. 4 is a diagram showing an example of setting the input lever in the same embodiment. , FIG. 5 is a diagram showing a conventional sound system, and FIG. 6 is a diagram showing a Dolby stereo system. 2.3...Input lever, 6...Encoder, 7...
- Recording medium, 11... Decoder, 12... Arithmetic device, Engineering 3... Direction vector memory, 14... Coefficient calculator, 1516 17.18 - Output calculator.

Claims (1)

[Claims] a direction input device for inputting information regarding the localization direction of the sound;
An encoder that encodes the direction signal and audio signal input by the direction input device into a digital audio format, a recording medium that records the encoded digital audio format signal, and a digital audio format signal recorded on the recording medium. A variable localization acoustic signal recording and reproducing device comprising: a decoder that decodes the direction signal and the audio signal; and an arithmetic device that calculates the audio signal based on the direction signal and a speaker installation position coefficient. .