JP7267007B2 - Information processing device, information processing method, and program - Google Patents

Description

The present invention relates to an information processing device, an information processing method, and a program.

Conventionally, when outputting sound according to the situation of a computer game, etc., there is known a technique of outputting reverberation sound corresponding to direct sound using an effector (reverberation effector, reverberator) (for example, Patent Document 1 ).

In addition, the data of the reflected sound (impulse response) for the impulse sound with a narrow time width in a building such as a hall is measured in advance and stored, and the signal of the sound effect, voice such as dialogue, and sound such as music that you want to output. There is known a technique of reproducing the reverberation in the hall or the like by performing a convolution operation. An effector using this technique is also called a convolution reverb.

JP-A-2000-267675

However, in the conventional technology, when the stages that output sound are different, it takes time and effort to measure the impulse response in each hall. Therefore, in one aspect, an object is to provide a technique capable of generating reverberant sound more appropriately.

In one proposal, the information processing device calculates the length of the impulse response, which is the data of the reflected sound for the impulse sound, the length from the output of the pulse sound to the return of the first reflected sound, and the volume attenuation index. The data of the impulse response is obtained by using the reception unit that receives the specified operation, the length of the impulse response, the length from the output of the pulse sound to the return of the first reflected sound, and the volume attenuation index. and an adjustment unit configured to generate reverberation sound for the audio data based on the impulse response data and the audio data stored in the storage unit, wherein the generation unit generates a pulse sound is set to 0, and the greater the index value indicating the time axis value of the impulse response data, the higher the probability of satisfying the condition. If the condition is not satisfied, the volume value of the impulse response data corresponding to the index value is set to 0, and if the condition is satisfied, the impulse The volume value of the response data approaches a value that exponentially decreases as the index value increases, and decreases exponentially as the index value increases. or set the volume value of the impulse response data to a value that decreases exponentially as the index value increases. , and the value obtained by multiplying the value of the sine of the angle at which the probability of the angle approaching 0 degrees increases as the index value increases.

According to one aspect, reverberant sound can be generated more appropriately.

It is a figure which shows the hardware structural example of the information processing apparatus which concerns on embodiment. 1 is a functional block diagram of an information processing device according to an embodiment; FIG. 4 is a flowchart showing an example of processing of the information processing device according to the embodiment; It is a figure explaining an example of the value which becomes large, so that the value of the index i which concerns on embodiment is large. FIG. 10 is a diagram illustrating an example of a value exponentially decreasing as the value of index i increases; FIG. 10 is a diagram illustrating an example of impulse response data when index i is greater than L _delay according to the embodiment;

An embodiment of the present invention will be described below based on the drawings.

<Hardware configuration>
FIG. 1 is a diagram showing a hardware configuration example of an information processing apparatus 10 according to an embodiment. The information processing apparatus 10 shown in FIG. 1 includes a drive device 100, an auxiliary storage device 102, a memory device 103, a CPU 104, an interface device 105, a display device 106, an input device 107, etc., which are connected to each other via a bus B. .

A game program that implements processing in the information processing device 10 is provided by the recording medium 101 . When the recording medium 101 recording the game program is set in the drive device 100 , the game program is installed from the recording medium 101 into the auxiliary storage device 102 via the drive device 100 . However, the game program does not necessarily have to be installed from the recording medium 101, and may be downloaded from another computer via the network. The auxiliary storage device 102 stores the installed game program, as well as necessary files and data.

The memory device 103 is, for example, a memory such as DRAM (Dynamic Random Access Memory) or SRAM (Static Random Access Memory). . The CPU 104 implements functions related to the information processing apparatus 10 according to programs stored in the memory device 103 . The interface device 105 is used as an interface for connecting to a network. A display device 106 displays a GUI (Graphical User Interface) or the like by a program. The input device 107 is composed of a controller or the like, a keyboard and a mouse or the like, or a touch panel and buttons or the like, and is used for inputting various operational instructions.

Note that an example of the recording medium 101 is a portable recording medium such as a CD-ROM, a DVD disc, a Blu-ray disc, or a USB memory. Examples of the auxiliary storage device 102 include a HDD (Hard Disk Drive), SSD (Solid State Drive), flash memory, and the like. Both the recording medium 101 and the auxiliary storage device 102 correspond to computer-readable recording media.

<Functional configuration>
Next, with reference to FIG. 2, the functional configuration of the information processing device 10 will be described. FIG. 2 is a functional block diagram of the information processing device 10 according to the embodiment.

The information processing device 10 has a storage unit 11 . The storage unit 11 is implemented using, for example, the auxiliary storage device 102 or the like. The storage unit 11 stores sound effects, recorded lines, audio data such as music, and the like.

The information processing apparatus 10 also includes a reception unit 12 , a generation unit 13 (an example of a “determination unit”), and an adjustment unit 14 . These units are implemented by one or more programs installed in the information processing device 10 causing the CPU 104 of the information processing device 10 to execute the processing.

The receiving unit 12 receives an operation to specify various parameters related to reverberation. The generator 13 generates (determines) impulse response data, which is reflected sound data for the impulse sound.

Based on the impulse response data generated by the generating unit 13 and the audio data stored in the storage unit 11, the adjustment unit 14 generates (adjusts) reverberation sound for the audio data, and outputs the reverberation sound to a speaker or the like. do. The adjustment unit 14 generates reverberant sound by, for example, convoluting the sound data and the impulse response data generated by the generation unit 13 .

<Processing>
Next, processing of the information processing apparatus 10 will be described with reference to FIGS. 3 to 4C. FIG. 3 is a flowchart showing an example of processing of the information processing device 10 according to the embodiment. FIG. 4A is a diagram illustrating an example of values that increase as the value of index i increases according to the embodiment. FIG. 4B is a diagram illustrating an example of values that exponentially decrease as the value of index i increases. FIG. 4C is a diagram illustrating an example of impulse response data when index i is greater than L _delay according to the embodiment.

In step S1, the receiving unit 12 receives an operation of designating various parameters related to reverberation. Here, the reception unit 12 performs an operation to set the length L of the impulse response data, the length L _delay from when the pulse sound is output until the first reflected sound is returned, and the volume attenuation index P _decay . Accept from users.

Note that L is the maximum index value of the impulse response data array IR[L] corresponding to the time (reverberation time) from when the pulse sound is output until the output of the reverberant sound is stopped and the sampling frequency. . Here, as the reverberation time, about 0.5 seconds may be specified in the case of a small room in which sound is output in a game or the like, and about several seconds in the case of a music hall or the like. For example, if the reverberation time is 5 seconds and the sound sampling frequency is 48 kHz, L is determined as 240000 (5×48k).

L _delay is a numerical value corresponding to the time from the output of the pulse sound to the return of the earliest initial reflection among the initial reflections from the wall, ceiling, floor, etc., and the sampling frequency. For example, when the time from the output of the pulse sound to the return of the earliest initial reflection is 10 msec, and the sampling frequency of the sound is 48 kHz, L is determined as 480 (10 m×48 k). The sound volume decay exponent P _decay is a value indicating the speed of decay, and the larger the value, the faster the speed of decay. For example, a value greater than 1 may be set as the value of P _decay .

Subsequently, the generation unit 13 sets impulse response data to 0 for the length of time from the output of the pulse sound to the return of the first reflected sound (step S2). Here, the generation unit 13 sets the values from IR[0] to IR[L _delay ] to values (for example, 0) equal to or less than a predetermined threshold.

Subsequently, the generation unit 13 initializes the index i indicating the value of the time axis of the impulse response data (step S3). Here, the generator 13 sets the value of i to 0, for example. Subsequently, the generation unit 13 determines whether or not the index i satisfies a condition that the probability of satisfying the condition increases as the value of the index i increases (step S4). Here, for example, the generation unit 13 first calculates a uniform random number value Ru. Note that Ru is, for example, a random number in which all real numbers appear with the same probability within an interval of 0 or more and less than 1. Then, for example, when the condition of Expression (1) below is satisfied, the generation unit 13 may determine that the condition is met. Note that L _body is LL _delay .

Ru<(i/ _Lbody ) (1)
As shown in FIG. 4A, the value 401 of i/L _body increases as the value of index i increases, so the probability that the condition of formula (1) is satisfied increases as the value of index i increases.

If the condition is not satisfied (NO in step S4), the generation unit 13 sets the impulse response data corresponding to the index i to a value (eg, 0) equal to or less than a predetermined threshold (step S5), and performs the process of step S7. proceed to In the process of step S5, the generator 13 sets the value of IR[L _delay +i], which is the impulse response data corresponding to the index i, to zero.

If the condition is satisfied (YES in step S4), the impulse response data when the index i is greater than L _delay is generated by a value that nonlinearly decreases as the value of the index i increases as the value of the index i increases. As the value of the index i increases, a value based on a random number such as white noise is set to a closer value (step S6). Through the processing in steps S5 and S6, the probability that the value of IR[i] exceeds the predetermined threshold increases as the value of index i increases. Therefore, as shown in FIG. 4C, the impulse response data 421 when the index i is greater than L _delay has a lower density of values that are not equal to or less than the predetermined threshold value as the value of the index i decreases. As the value of i increases, the density of values that are not below the predetermined threshold increases. Further, as a result of the processing in step S6, as shown in FIG. 4C, the impulse response data 421 when the index i is greater than L _delay gradually decreases while fluctuating in volume, and gradually approaches white noise. This makes it possible to generate impulse response data for outputting reverberant sound close to actual reverberant sound without measuring the actual impulse response in a hall or the like.

In the process of step S6, the generation unit 13 calculates GainScale (attenuation curve, an example of a “value that decreases nonlinearly”), which is a value that exponentially decreases as the value of the index i increases. For example, the generation unit 13 calculates the value of GainScale using the following equation (2). In addition, "ân" indicates the n-th power of a.

GainScale = (1-i/L _body )^P _decay (2)
By Equation (4), GainScale value 411 becomes a value that decreases exponentially as the value of index i increases, as shown in FIG. 4B.

Here, for example, the generation unit 13 first calculates the normal random number value Rn. Rn may be, for example, a random number having a normal distribution within an interval greater than 0 and less than 1. In this case, the generation unit 13 may calculate Rn by transforming a uniform random number greater than 0 and less than or equal to 1 using the Box-Muller transform.

Then, the generation unit 13 calculates a value W representing white noise using the following equation (3).

W = (Rn-0.5)/V (3)
Note that V is a constant for adjusting the volume of white noise, and the generator 13 may set the value of V to 4, for example. Then, the generation unit 13 sets IR[L _delay +i] to the value calculated by the following formula (4).

IR[ _Ldelay +i]=(S(1−i/ _Lbody )+W(i/ _Lbody ))×GainScale (4)
where S is the sign of W and has values of -1, 0, and 1. The generator 13 sets S to −1 if the value of W is negative, sets S to 0 if the value of W is 0, and sets S to 1 if the value of W is positive.

As a result, as shown in FIG. 4C, the impulse response data 421 corresponding to the index i has a GainScale that decreases exponentially as the value of the index i increases as the value of the index i decreases. As the value of the index i increases, the value is set closer to the value obtained by multiplying the white noise value W by the GainScale.

Subsequently, the generator 13 increments (increases by one) the value of the index i (step S7). Subsequently, the generation unit 13 determines whether or not the value of the index i satisfies the termination condition (step S8). Here, the generation unit 13 determines that the end condition is satisfied when the value of the index i becomes equal to the value of L _delay . If the value of index i does not satisfy the termination condition (NO in step S8), the process proceeds to step S4. On the other hand, if the value of index i satisfies the termination condition (YES in step S8), the process is terminated.

<Modification 1>
In step S6 of FIG. 3, the generating unit 13 sets IR[L delay +i] to IR[L _delay +i], instead of setting the value calculated using Equation (4) to IR[ L _delay +i].

In this case, the generator 13 first calculates a uniform random number value Ru2. Note that Ru2 is, for example, a random number in which all real numbers appear with the same probability within an interval of 0 to 1 inclusive. Then, the generation unit 13 calculates the angle θ by the following formula (5).

θ=(π/2)×(1−Ru2×(i/L _body )) (5)
Then, the generation unit 13 inverts the sign of the angle θ with a probability of 1/2. Then, the generation unit 13 sets IR[L _delay +i] to the value calculated by the following formula (6).

IR[ _Ldelay +i]=sinθ×GainScale (6)
As a result, the impulse response data array IR[L] approaches GainScale, which is a value exponentially decreasing as the value of index i increases, as the value of index i decreases. In the array IR[L] of the impulse response data, the value of the index i is multiplied by the value obtained by multiplying the gain scale by the sine value of the angle at which the probability of the angle being closer to 0 degrees increases as the value of the index i increases. It is set to a value that approaches as it is larger. Note that the generation unit 13 may switch the method for determining the value of IR[L _delay +i] by user operation. The generation unit 13 also sets IR[L _delay +i] to the value calculated by the following equation (7).

IR[ _Ldelay +i]=(S(1−i/ _Lbody )+sinθ(i/ _Lbody ))×GainScale (7)
As a result, the impulse response data corresponding to the index i approaches the GainScale, which is a value exponentially decreasing as the value of the index i increases, as the value of the index i decreases, and the value of the index i increases. The larger the value of the index i, the higher the probability that the angle will be close to 0 degrees.

<Modification 2>
Each functional unit of the information processing device 10 may be realized by cloud computing configured by one or more computers, for example.

Although the embodiments of the present invention have been described in detail above, the present invention is not limited to such specific embodiments, and various modifications can be made within the scope of the gist of the invention described in the claims.・Changes are possible.

10 information processing device 11 storage unit 12 reception unit 13 generation unit 14 adjustment unit

Claims (3)

a reception unit that receives an operation to specify the length of an impulse response, which is data of a reflected sound for an impulse sound, the length from the output of the pulse sound to the return of the first reflected sound, and the volume attenuation index;
a generation unit that generates the impulse response data using the length of the impulse response, the length from the output of the pulse sound to the return of the first reflected sound, and the volume attenuation index;
an adjustment unit that generates reverberation sound for the audio data based on the impulse response data and the audio data stored in the storage unit;
has
The generating unit
setting the volume value of the impulse response data from the output of the pulse sound to the return of the first reflected sound to 0;
Determining whether a condition is satisfied such that the greater the index value indicating the value of the time axis of the impulse response data, the higher the probability of being satisfied;
if the condition is not satisfied, setting the volume value of the impulse response data corresponding to the index value to 0;
When the condition is satisfied, the volume value of the impulse response data approaches a value that decreases exponentially as the index value increases as the index value decreases, and the index value increases. As the index value increases, the volume value of the impulse response data is set so as to approach a value obtained by multiplying the exponentially decreasing value by the white noise value. It is determined to approach a value obtained by multiplying an exponentially decreasing value by a sine value of an angle at which the probability of an angle close to 0 degrees increases as the index value increases.
Information processing equipment. information processing equipment,
a reception unit that receives an operation to specify the length of an impulse response, which is data of reflected sound for an impulse sound, the length from the output of the pulse sound to the return of the first reflected sound, and the volume attenuation index;
a generation unit that generates the impulse response data using the length of the impulse response, the length from the output of the pulse sound to the return of the first reflected sound, and the volume attenuation index;
an adjusting unit that generates reverberant sound for the audio data based on the impulse response data and the audio data stored in the storage unit;
function as
The generating unit
setting the volume value of the impulse response data from the output of the pulse sound to the return of the first reflected sound to 0;
Determining whether a condition is satisfied such that the greater the index value indicating the value of the time axis of the impulse response data, the higher the probability of being satisfied;
if the condition is not satisfied, setting the volume value of the impulse response data corresponding to the index value to 0;
When the condition is satisfied, the volume value of the impulse response data approaches a value that decreases exponentially as the index value increases as the index value decreases, and the index value increases. As the index value increases, the volume value of the impulse response data is set so as to approach a value obtained by multiplying the exponentially decreasing value by the white noise value. A program for determining a value approaching a value obtained by multiplying an exponentially decreasing value by a sine value of an angle at which the probability of an angle close to 0 degrees increases as the index value increases. The information processing device
a process of accepting an operation to specify the length of the impulse response, which is the data of the reflected sound for the impulse sound, the length from the output of the pulse sound to the return of the first reflected sound, and the volume attenuation index;
a process of generating the impulse response data using the length of the impulse response, the length from the output of the pulse sound to the return of the first reflected sound, and the volume attenuation index;
a process of generating reverberant sound for the audio data based on the impulse response data and the audio data stored in a storage unit;
and run
The process of generating impulse response data includes:
setting the volume value of the impulse response data from the output of the pulse sound to the return of the first reflected sound to 0;
Determining whether a condition is satisfied such that the greater the index value indicating the value of the time axis of the impulse response data, the higher the probability of being satisfied;
if the condition is not satisfied, setting the volume value of the impulse response data corresponding to the index value to 0;
When the condition is satisfied, the volume value of the impulse response data approaches a value that decreases exponentially as the index value increases as the index value decreases, and the index value increases. As the index value increases, the volume value of the impulse response data is set so as to approach a value obtained by multiplying the exponentially decreasing value by the white noise value. Information processing that determines a value approaching a value obtained by multiplying an exponentially decreasing value by a sine value of an angle that increases the probability of an angle approaching 0 degrees as the index value increases. Method.

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