JP2006270522A - Sound image localization controller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize an optimal sound field according to the "position" and the "direction" of a listener in a living room. <P>SOLUTION: By means of video cameras 14-1 to 14-8 provided in the living room, a listener image is imaged, from which a CPU 2 obtains the position and the direction of the listener. When a signal source 18 outputs audio signals of a 5.1 surround system, the above signals except for a subwoofer are supplied to a mixer 20, in which signals of "16 systems", SA0-SA7, SB0-SB7 are generated so as to produce sound from "16" speakers. The mixing ratio in the mixer 20 is calculated so as to provide the listener with the optimal sound field. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a sound image localization control device suitable for use in a surround system.

  In a 5.1 surround system that has recently become popular, a plurality of speakers are arranged around a listener. Here, the channel assigned to each speaker is fixedly determined for each speaker. Patent Document 1 discloses a technique for detecting the position of a listener and automatically correcting the localization in a system using two speakers. In a surround system, the distance from the listener to each speaker is ideally the same, but the distance may not always be the same due to restrictions such as the listening room. Therefore, Patent Document 2 discloses a technique for simulating an ideal speaker arrangement by delaying the audio signal of each channel in accordance with the distance from each speaker to the listener.

JP-A-8-265900 JP-A-7-87598

By the way, in each technique described above, various audio signals are corrected in accordance with the “position” of the listener, but no particular control is performed regarding the “direction” of the listener's face. In addition, when sound signals are emitted using a surround system at an event venue, the position and direction of the listener changes every moment, but the sound signals can be emitted under optimum conditions depending on the state of such listeners. It was not a thing.
The present invention has been made in view of the above-described circumstances, and an object thereof is to provide a sound image localization control device that can provide an optimum sound field according to the “position” and “direction” of a listener.

In order to solve the above problems, the present invention is characterized by having the following configuration. The parentheses are examples.
In the sound image localization control apparatus according to claim 1, position / direction detection means (2, 12, 14) for detecting the position and direction of the listener, and m systems of inputs based on the position and direction of the listener. A mixing coefficient determining means (2) for determining m · n mixing coefficients for the signal and n output signals, and mixing the m input signals based on the determined mixing coefficients; And mixing means for outputting the output signals of the n systems.
The sound image localization control apparatus according to claim 1, wherein the n-system output signals are emitted and then simultaneously arrived at the listener based on the position of the listener. Delay time determining means (2) for determining a delay time for delay, and delay means (22) for delaying any one of the output signals of the n systems based on the determined delay time. And

  As described above, according to the present invention, by detecting the position and direction of the listener, m · n mixing coefficients are calculated, and m system input signals are mixed based on the calculated mixing coefficients to obtain n Since it is configured to output the output signal of the system, an optimal sound field can be realized according to the “position” and “direction” of the listener.

1． Configuration of Embodiment Next, the configuration of a surround system according to an embodiment of the present invention will be described with reference to FIG.
In FIG. 1, reference numeral 18 denotes a signal source, which is a “6” system signal constituting a 5.1 surround system, that is, a front left signal S_L, a center signal S_C, a front right signal S_R, a surround left signal S_LS, a surround right signal S_RS, and A subwoofer signal S_SW is output. Reference numeral 20 denotes a mixer. The “6” system signals SA0 to SA7 are obtained as a result of mixing the “5” system signals excluding the subwoofer signal S_SW and mixing them. , SB0 to SB7 are output. More specifically, in the mixer 20, for each input signal (total “5” system), the ratio of the input signal to the output signals SA0 to SA7 and SB0 to SB7 (total “16” system). “80” (= 5 × 16) types of mixing coefficients indicating whether to reflect in FIG. Each input signal is mixed in accordance with the mixing coefficient, and output signals SA0 to SA7 and SB0 to SB7 are generated.

  Reference numeral 22 denotes a delay unit, which performs a delay process for localization correction on the “16” system output signals. Reference numeral 24 denotes an amplifier that amplifies these “16” system signals SA0 to SA7, SB0 to SB7, and the subwoofer signal S_SW. The amplified signals are supplied to the speakers A0 to A7, B0 to B7, and the subwoofers 26 and 27, respectively. A CPU 2 controls each unit via the bus 16 based on a control program (details will be described later) stored in the ROM 4. A RAM 6 is readable / writable by the CPU 2 and stores various data used for the control program. Reference numeral 8 denotes a display that displays various types of information to the operator. Reference numeral 10 denotes an input device, which includes a keyboard and the like for giving instructions to the CPU 2. 14-1 to 14-8 are “eight” video cameras, which take images in various places in the listening room. An interface unit 12 receives these imaging results.

Next, the configuration of the listening room and the arrangement of the speakers will be described with reference to FIG.
In FIG. 2, the listening room is composed of rooms 30, 31 each having a substantially square shape.
In the room 30, a speaker A0 is arranged at the center on the right side of the figure, and the speakers A1 to A7 are arranged at the corners and the center of the side that are sequentially separated from the speaker A0 by “45 °” in order. In addition, the video cameras 14-1 to 14-4 are provided at the four corners of the room 30 so as to face the center of the room 30. Similarly, in the room 31, a speaker B0 is arranged at the center on the right side of the figure, and the speakers B1 to B7 are arranged at the corners and the center of the side that are sequentially separated from the speaker B0 by “45 °”. ing. In addition, the video cameras 14-5 to 14-8 are provided at the four corners of the room 31 so as to be directed toward the center of the room 31. These speakers and video cameras are suspended from the ceilings of the rooms 30 and 31, respectively, and a detachable partition plate 32 extends between the rooms 30 and 31. Although the subwoofers 26 and 27 are not particularly illustrated, they are arranged at appropriate locations on the floors in the rooms 30 and 31, respectively.

2． Next, the operation of this embodiment will be described. First, when the CPU 2 is started up, a speaker control routine shown in FIG. 3 is started. In the figure, when the process proceeds to step SP2, predetermined initial setting is performed. Next, when the process proceeds to step SP4, images taken by the video cameras 14-1 to 14-8 are taken into the RAM 6 via the interface unit 12, and the images are analyzed. Here, the details of the analysis processing will be described. First, when a listener enters the listening room, an image of the listener is picked up by the video cameras 14-1 to 14-8. When these images are supplied to the CPU 2 via the interface unit 12, the CPU 2 grasps the position of the listener and the direction of the face. That is, since the positions and directions of these video cameras are known, the position of the listener is immediately grasped by the position of the listener image on the image captured by each camera. Furthermore, the direction of the listener's face is also grasped by the position of the listener's ear, eyeball, nose, etc. in each image.

  Next, when the process proceeds to step SP6, it is determined whether or not the analysis process has been successful, that is, whether or not the listener position and the face direction have been analyzed. In the first place, when there is no listener in the listening room, or when the presence of the listener can be grasped and the face direction cannot be analyzed, “NO” is determined, and the process returns to step SP4. As a result, the image is captured and the analysis process is repeated until the analysis is successful. If the analysis is successful, “YES” is determined in step SP6, and the process proceeds to step SP8. Here, the mixing coefficient in the mixer 20 and the delay time in the delay unit 22 are updated by the CPU 2 in accordance with the position of the listener and the face direction. Then, the process returns to step SP4, and thereafter, the processes of steps SP4 to SP8 are repeated.

  In step SP8, the delay time in the delay unit 22 is set so that the signals SA0 to SA7 and SB0 to SB7 output simultaneously from the mixer 20 simultaneously arrive at the listener via the speakers. That is, a longer delay time is set for a speaker having a shorter distance from the listener. In the mixer 20, the mixing coefficient is set so that the sound signals of the respective channels constituting the 5.1 surround system can be heard from an appropriate direction with reference to the direction of the listener's face. By the way, in a present Example, the partition plate 32 is inserted between the rooms 30 and 31, the operation mode which uses these as an individual listening room, this partition plate 32 is removed, and the rooms 30 and 31 are made into "1. There are operation modes used as “single” listening rooms. Therefore, first, the details of the mixing coefficient when only a single room (in this case, room 30) is used will be described with reference to FIGS.

  First, in FIG. 4A, when the listener is located in the center of the room 30 and faces the direction D0 of the speaker A0, each mixing coefficient is set as shown in FIG. 5A. In this figure, the signal SA0 is generated with the mixing coefficient of the center signal S_C set to “1.0” and the mixing coefficient of other signals set to “0.0”, and eventually becomes a signal equal to the center signal S_C. Similarly, the signal SA1 is equal to the front right signal S_R, the signal SA3 is equal to the surround right signal S_RS, the signal SA5 is equal to the surround left signal S_LS, and the signal SA7 is equal to the front left signal S_L. The signals SA2, SA4, SA6 are silent because the mixing coefficients of all input signals are “0.0”. As a result, as shown in FIG. 4A, each speaker A0, A1, A3, A5, A7 includes a center speaker (C), a front right speaker (R), a surround right speaker (RS), and a surround left speaker. (LS) and the function of the front left speaker (L) are respectively provided.

  Further, when the listener faces the direction D1 of the speaker A1, each mixing coefficient is set as shown in FIG. That is, as shown in FIG. 4B, for each speaker A0, A1, A2, A4, A6, the front left speaker (L), the center speaker (C), the front right speaker (R), and the surround right speaker. (RS) and surround left speaker (LS) functions are provided. Even when the listener faces the front of another speaker, the function as the center speaker (C) is similarly given to the front speaker, and the other speakers have a positional relationship with the center speaker (C). Corresponding functions are given. The state is shown in FIGS.

  Also, the listener does not necessarily face the front of any speaker, but may face between “two” speakers. In such a case, the mixing coefficient of the center signal S_C for the “two” speakers is set so that the sound image of the center signal S_C is localized in front of the listener, and other signals are similarly set to their intended positions. A mixing coefficient is set so that the sound image is localized. As an example, FIG. 5C shows a mixing coefficient in the case where the listener faces a direction D0.5 that is intermediate between the direction D0 and the direction D1. In the figure, the front left signal S_L is distributed with a mixing ratio of “0.5” with respect to the signals SA0 and SA7. As a result, the sound image of the front left signal S_L is localized at the midpoint between the speakers A0 and A7. Similarly, the center signal S_C is located at the middle points of the speakers A0 and A1, the front right signal S_R is located at the speakers A1 and A2, the surround right signal S_RS is located at the speakers A3 and A4, and the surround left signal S_LS is located at the middle points between the speakers A5 and A6. It will be.

  Next, a method for setting a mixing coefficient when the partition plate 32 is removed and the rooms 30 and 31 are used as one listening room will be described with reference to FIGS. Here, assuming a value of “room coefficient R”, when the room coefficient R is “0”, the listener is located in the room 30, and when it is “1”, the listener is located in the room 31, In the case of “0.5”, the listener is located at the boundary between the rooms 30 and 31. First, as shown in FIG. 6A, when the listener is located near the center of the room 30 and faces the direction D0, each mixing coefficient is as shown in FIG. 7A. In this example, the mixing coefficients related to the speakers in the room 30 are the same as those shown in FIG. 5A described above, and all the speakers in the room 31 are set to the silent state. Further, as shown in FIG. 6B, when the listener is located at the boundary between the rooms 30 and 31 (room coefficient R = 0.5) and faces the direction D0, each mixing coefficient is shown in FIG. 7B. As shown. In this example, the front left speaker (L), the center speaker (C), the front right speaker (R), the surround right speaker (RS), and the surround left speaker (LS) are included in each speaker B7, B0, B1, A3, and A5. Each of the functions is given.

As shown in FIG. 6 (c), when the listener is located near the center of the room 31 (room coefficient R = 1) and faces the direction D0, each mixing coefficient is as shown in FIG. 7 (c). Become. In this example, the front left speaker (L), the center speaker (C), the front right speaker (R), the surround right speaker (RS), and the surround left speaker (LS) are included in each speaker B7, B0, B1, B3, and B5. Each of the functions is given. The room coefficient R continuously increases in the range of “0” to “1” according to the listener position as the listener walks from the position of FIG. 6A to the position of FIG. 6C. It is a value to go. When the room coefficient R is greater than “0” and less than “0.5”, each mixing coefficient is linearly interpolated between the coefficient shown in FIG. 7A and the coefficient shown in FIG. When the room coefficient R is greater than “0.5” and less than “1”, each mixing coefficient includes the coefficient shown in FIG. 7B and the coefficient shown in FIG. The value is linearly interpolated by the coefficient R. As a result, switching of speakers according to the position of the listener is executed very smoothly.
There wasn't.

  As described above, according to the present embodiment, since the mixing coefficient is determined every moment according to the “position” and “direction” of the listener, the listener moves in the listening room or changes the direction. In such a case, the optimum sound field can be provided very smoothly.

3． Modifications The present invention is not limited to the above-described embodiments, and various modifications can be made as follows, for example.
(1) In the above embodiment, the example in which the present invention is applied to the 5.1 surround system has been described. However, it is needless to say that the present invention is not limited to the 5.1 surround system. For example, as shown in FIGS. 8A and 8B, the present invention may be applied to a 6-channel or 7-channel surround system, and the function of the speaker may be switched according to the direction of the listener.

(2) In the above embodiment, an optimal sound field is provided for a “single” listener, but a plurality of listeners are detected by the video cameras 14-1 to 14-8. May provide a sound field with a wide sweet spot for the plurality of listeners. As an example, FIG. 8C shows an example in which the function of each speaker is set as a 7-channel surround system when “three” listeners are detected across the rooms 30 and 31. In the example of FIG. 8C, the function of each speaker is fixed to the illustrated function as long as the position of the listener is as illustrated, and the function is not particularly switched according to the direction of the listener.

(3) The present invention can also be applied to a security system. For example, when a suspicious person is found outside the listening room, it is possible to emit a sound as if a plurality of people are talking while walking. In addition, since the speaker that is the source of the sound can be smoothly moved from room to room, a highly realistic sound can be emitted.

(4) In the above embodiment, the video cameras 14-1 to 14-8 are used to detect the position and direction of the listener. However, the position and direction of the listener can be detected by other methods. . For example, a listener may be equipped with a GPS receiver for detecting a position and a geomagnetic sensor for detecting a direction, and the position and direction measured by these may be transmitted to the interface unit 12 by wire or wirelessly. It is done. In such a case, as an initial setting, the latitude, longitude, and direction when the listener stands in the center of the room 30 and faces the speaker A0 are recorded in the RAM 6, and then the listener stands in the center of the room 31 and faces the speaker B0. The latitude, longitude and direction at that time may be recorded in the RAM 6. Thereafter, the listener's position and direction at each time point can be grasped by measuring the latitude, longitude, and direction of the listener at a predetermined cycle and comparing the measurement result with the stored value in the RAM 6.

It is a block diagram of the surround system of one Example of this invention. It is an arrangement view of speakers and video cameras in a listening room. It is a flowchart of the control program of one Example. It is operation | movement explanatory drawing of the Example in the case of using only the room 30. FIG. It is a figure which shows the mixing coefficient in the case of using only the room 30. FIG. It is operation | movement explanatory drawing of the Example in the case of using room 30,31. It is a figure which shows the mixing coefficient in the case of using the rooms 30 and 31. FIG. It is operation | movement explanatory drawing of the various modifications of this invention.

Explanation of symbols

  2: CPU (mixing coefficient determining means, delay time determining means), 4: ROM, 6: RAM, 8: display, 10: input device, 12: interface unit (position / direction detecting means), 14-1 to 14- 8: Video camera (position / direction detection means), 16: bus, 18: signal source, 20: mixer, 22: delay unit, 24: amplifier, 32: partition plate, 26, 27: subwoofer, 30, 31: Room, A1 to A7, B1 to B7: Speaker, C: Center speaker, R: Front right speaker, L: Front left speaker, LS: Surround left speaker, RS: Surround right speaker.

Claims (2)

Position / direction detection means for detecting the position and direction of the listener;
Mixing coefficient determining means for determining m · n mixing coefficients for m input signals and n output signals based on the position and direction of the listener;
A sound image localization control apparatus comprising: mixing means for mixing the m system input signals based on the determined mixing coefficients and outputting the n system output signals. Delay time determining means for determining a delay time for simultaneously arriving at the listener after the output signals of the n systems are emitted based on the position of the listener;
The sound image localization control apparatus according to claim 1, further comprising delay means for delaying any one of the n systems of output signals based on the determined delay time.

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