JP5169566B2 - Reverberation imparting device and program - Google Patents

Description

  The present invention relates to a technique for imparting reverberation to an acoustic signal.

Conventionally, a technique for imparting reverberation to an acoustic signal by a convolution operation between the acoustic signal and an impulse response has been proposed. Patent Document 1 discloses a technique for changing an impulse response used for imparting reverberation to an acoustic signal in the middle of imparting reverberation. In the technique of Patent Document 1, as shown in FIG. 10, the process of generating the reverberation signal R1 by convolving the impulse response H1 before the change with the acoustic signal VIN, and the process of generating the reverberation signal R1 with the acoustic signal VIN. The reverberation signal R2 is generated in parallel, and the reverberation signal VOUT is synthesized by crossfading the reverberation signal R1 and the reverberation signal R2 within the interval C.
U.S. Pat. No. 6,216,697

  However, in the technique of Patent Document 1, the convolution calculation of the impulse response H1 and the convolution calculation of the impulse response H2 are executed in parallel for the section C to be crossfade in the acoustic signal VIN. There is a problem in that the amount of calculation increases during processing of section C of signal VIN. When the time length (reverberation time) of the impulse response H1 and the impulse response H2 is long, the amount of calculation for the section C is particularly serious. In view of the above circumstances, an object of the present invention is to reduce the amount of calculation when changing an impulse response used for imparting reverberation to an acoustic signal.

  In order to solve the above-described problem, the reverberation imparting device according to the first aspect of the present invention includes a section including a first section (for example, section S1 in FIG. 3) and the start of the first section in the acoustic signal. (E.g., section T1 in FIG. 3) first calculation means for generating a first reverberation signal obtained by convolving the first impulse response, and second after the first section has elapsed from the start point of the first section of the acoustic signal. Second calculation means for generating a second reverberation signal in which a first portion of the first impulse response is convoluted into a section (for example, section T2 in FIG. 3) including the end point of the section (for example, section S2 in FIG. 3); The first impulse response of the second impulse response is included in a section (for example, section T3 in FIG. 3) including the signal from the start point of the second section to the end point of the third section (for example, section S3 in FIG. 3) after the passage of the second section. A third computing means for generating a third reverberation signal convolved with a portion; A fourth computation means for generating a fourth reverberation signal in which the second impulse response is convoluted in a section including the interval and after the passage of the third section (for example, section T4 in FIG. 3), and second from the first reverberation signal. First synthesizing means for crossfading the first and second reverberation signals in the first interval so as to make a transition to the reverberation signal; and in the second interval so as to make a transition from the second reverberation signal to the third reverberation signal. The second reverberation means for crossfading the second reverberation signal and the third reverberation signal, and the third reverberation signal and the fourth reverberation signal in the third interval so as to transit from the third reverberation signal to the fourth reverberation signal. And third synthesizing means for crossfading.

  In the reverberation imparting device according to the first aspect, the convolution calculation of the first impulse response by the first calculation means and the convolution calculation of the first part of the first impulse response by the second calculation means are the first of the acoustic signals. The convolution calculation of the first portion of the second impulse response by the third calculation means and the convolution calculation of the second impulse response by the fourth calculation means are executed for the third section of the acoustic signal. The convolution calculation of the first part of the first impulse response by the second calculation means and the convolution calculation of the first part of the second impulse response by the third calculation means are executed for the second section of the acoustic signal. In the above configuration, it is not necessary to execute all the convolution operations of the first impulse response and all the convolution operations of the second impulse response for the common section of the acoustic signal. It is possible to reduce the amount of calculation.

  The reverberation imparting apparatus according to the second aspect of the present invention includes a first period (for example, section S1 in FIG. 5) and a section (for example, section T1 in FIG. 5) including the first section before the start of the first section. First calculation means for generating a first reverberation signal in which the first impulse response is convolved, and a second section (for example, section S2 in FIG. 5) after the first section has elapsed from the start point of the first section of the acoustic signal. A second calculation means for generating a second reverberation signal in which the first portion of the first impulse response is convoluted in a section including the end point of (for example, section T2 in FIG. 5), a second section of the acoustic signal, and the second section A fourth operation means for generating a fourth reverberation signal in which the second impulse response is convoluted into a section including after two sections (for example, section T4 in FIG. 5), and transition from the first reverberation signal to the second reverberation signal. The first reverberation signal and the second reverberation signal are cross-faded within the first interval. It includes a 1 synthesizing means, and second combining means for crossfading second reverberation signal within the second interval and a fourth reverberation signal to transition from the second reverberation signal to the fourth reverberation signal.

  In the reverberation imparting device according to the second aspect, the convolution calculation of the first impulse response by the first calculation means and the convolution calculation of the first part of the first impulse response by the second calculation means are the first of the acoustic signals. The convolution calculation of the first portion of the first impulse response by the second calculation means and the convolution calculation of the second impulse response by the fourth calculation means are executed for the second section of the acoustic signal. In the above configuration, it is not necessary to execute all the convolution operations of the first impulse response and all the convolution operations of the second impulse response for the common section of the acoustic signal. It is possible to reduce the amount of calculation.

  The reverberation imparting apparatus according to the third aspect of the present invention includes a first period (for example, section S1 in FIG. 7) and a section (for example, section T1 in FIG. 7) including the first section before the start of the first section. First calculation means for generating a first reverberation signal obtained by convolving the first impulse response, and a third section (for example, section S3 in FIG. 7) after the first section has elapsed from the start point of the first section of the acoustic signal. A third computation means for generating a third reverberation signal in which the first portion of the second impulse response is convoluted in a section including the end point (for example, section T3 in FIG. 7), a third section of the acoustic signal, and the third section A fourth operation means for generating a fourth reverberation signal in which the second impulse response is convoluted in a section including after the passage of three sections (for example, section T4 in FIG. 7), and transition from the first reverberation signal to the third reverberation signal. The first reverberation signal and the third reverberation signal are cross-faded within the first interval. 1 comprises a synthesizing unit, and a second combining means for crossfading third reverberation signal and the fourth reverberation signal within the third section to transition from the third reverberation signal to the fourth reverberation signal.

  In the reverberation imparting device according to the third aspect, the convolution calculation of the first impulse response by the first calculation means and the convolution calculation of the first part of the second impulse response by the third calculation means are the first of the acoustic signals. The convolution calculation of the first portion of the second impulse response by the third calculation means and the convolution calculation of the second impulse response by the fourth calculation means are executed for the third section of the acoustic signal. In the above configuration, it is not necessary to execute all the convolution operations of the first impulse response and all the convolution operations of the second impulse response for the common section of the acoustic signal. It is possible to reduce the amount of calculation.

  Note that the first part of the first impulse response in each of the above aspects is an arbitrary part of the first impulse response. However, in consideration of the tendency that the section including the initial reflected sound in the impulse response particularly characterizes the impression of the reverberant sound, the predetermined length section including the start point in the first impulse response is defined as the first portion (for example, the portion PA). It is preferably selected. The same applies to the second impulse response, and a section of a predetermined length including the start point in the second impulse response is suitable as the second portion (for example, the portion NB).

  In the specific example of the reverberation imparting device according to the first aspect or the second aspect, the first calculation means convolves the second portion other than the first portion (for example, the portion PB) of the first impulse response with the acoustic signal. Thus, the first convolution unit (for example, the convolution unit 312 in FIG. 9) that generates the reverberation signal, the reverberation signal generated by the first convolution unit, and the second reverberation signal generated by the second arithmetic unit are added. In this way, first adding means (for example, the adding unit 314 in FIG. 9) for generating the first reverberation signal is included. In the above aspect, the reverberation signal generated by the first calculation means from the second portion of the first impulse response and the second reverberation signal generated by the second calculation means from the first portion of the first impulse response are added. Thus, since the first reverberation signal is generated, the amount of calculation by the first calculation unit is reduced as compared with the configuration in which the first calculation unit performs all the convolution calculations of the first impulse response.

  In the specific example of the reverberation imparting device according to the first aspect or the third aspect, the fourth calculation means convolves a second part (for example, the part NB) other than the first part of the second impulse response with the acoustic signal. Thus, the second convolution means (for example, the convolution unit 342 in FIG. 9) that generates the reverberation signal, the reverberation signal generated by the second convolution means, and the third reverberation signal generated by the third arithmetic means are added. Thus, second adding means (for example, the adding unit 344 in FIG. 9) for generating the fourth reverberation signal is included. In the above configuration, the reverberation signal generated by the fourth calculation means from the second portion of the second impulse response and the third reverberation signal generated by the third calculation means from the first portion of the second impulse response are added. Since the fourth reverberation signal is generated, the amount of calculation by the fourth calculation means is reduced as compared with the configuration in which the fourth calculation means performs all the convolution calculations of the second impulse response.

  In the reverberation imparting apparatus according to the first to third aspects, the first calculation means generates the first reverberation signal from only the section (for example, section T1 in FIG. 8) before the end point of the first section in the acoustic signal. If the structure which produces | generates a 4th reverberation signal only from the area (for example, area T4 of FIG. 8) after the start point of the 3rd area among acoustic signals is adopted, and the 4th calculation means is adopted. The amount of computation by the fourth computing means is reduced. In addition, the second calculation means in the first mode or the second mode may be configured such that the second reverberation signal is obtained only from a section (for example, section T2 in FIG. 8) from the start point of the first section to the end point of the second section in the acoustic signal. And the third calculation means in the first mode or the third mode are used only from the section (for example, section T3 in FIG. 8) from the start point of the second section to the end point of the third section in the acoustic signal. If the configuration for generating the third reverberation signal is employed, the amount of calculation by the second calculation means and the third calculation means is reduced.

  The reverberation imparting apparatus according to each of the above aspects is realized by hardware (electronic circuit) such as a DSP (Digital Signal Processor) dedicated to imparting reverberation, or a general purpose such as a CPU (Central Processing Unit). This is also realized by cooperation between the arithmetic processing unit and the program. For example, the program for realizing the reverberation imparting device according to the first aspect is the first reverberation signal obtained by convolving the first impulse response into a section including the first section and the start of the first section of the acoustic signal. A first computation process for generating the first impulse response in a section including the first signal from the start point of the first section to the end point of the second section after the first section of the acoustic signal. 2 The second calculation process for generating a reverberation signal, and the first portion of the second impulse response is folded into a section including the start point of the second section and the end point of the third section after the second section of the acoustic signal. A fourth reverberation signal in which the second impulse response is convoluted in a section including the third calculation process for generating the third reverberation signal and the third section of the acoustic signal and after the third section has elapsed. Fourth arithmetic processing and transition from the first reverberation signal to the second reverberation signal As described above, the first reverberation signal and the second reverberation signal are cross-faded in the first interval, and the second reverberation in the second interval so that the second reverberation signal transitions to the third reverberation signal. A second synthesis process for crossfading the signal and the third reverberation signal, and a crossfade between the third reverberation signal and the fourth reverberation signal within the third interval so as to transition from the third reverberation signal to the fourth reverberation signal. The computer executes the third synthesis process. Similarly, for the reverberation imparting apparatus according to the second aspect or the third aspect, a program for causing a computer to function as the reverberation imparting apparatus is specified. According to the program of this invention, the effect | action and effect similar to the reverberation provision apparatus which concern on each above aspect are show | played. The program of the present invention is provided to a user in a form stored in a computer-readable recording medium and installed in the computer, or provided from a server device in a form of distribution via a communication network and installed in the computer. Is done.

<A: First Embodiment>
FIG. 1 is a block diagram of a reverberation imparting apparatus according to the first embodiment of the present invention. The reverberation imparting apparatus 100 is supplied with an acoustic signal VIN representing a waveform on the time axis of sound (musical sound or voice). The supply source (not shown) of the acoustic signal VIN is, for example, a sound collecting device that generates an acoustic signal VIN corresponding to surrounding sounds, or a playback device that acquires and outputs the acoustic signal VIN from a recording medium. The reverberation imparting device 100 generates and outputs a reverberation signal VOUT obtained by adding reverberation to the acoustic signal VIN. The reverberation signal VOUT is reproduced as a sound wave by being supplied to a sound emitting device (not shown) such as a speaker or headphones.

  As shown in FIG. 1, the reverberation imparting device 100 is a computer system including an arithmetic processing device 12, a storage device 14, and an input device 16. The storage device 14 stores a program executed by the arithmetic processing device 12 and data used by the arithmetic processing device 12. A known recording medium such as a semiconductor storage device or a magnetic storage device is arbitrarily adopted as the storage device 14. The storage device 14 stores a plurality of impulse responses H (H1, H2). Each impulse response H is a sample series (convolution calculation coefficient sequence) representing a waveform of a reverberant sound when an impulse sound is generated in the acoustic space. The acoustic characteristics (characteristics of the acoustic space from which the impulse response H is collected) are different for each impulse response H.

  The arithmetic processing unit 12 implements various functions (convolution operation unit 22 and waveform synthesis unit 24) by executing a program stored in the storage device 14. The arithmetic processing unit 12 of this embodiment generates a reverberation signal VOUT by executing a convolution operation between the acoustic signal VIN and the impulse response H. The impulse response H used for applying reverberation (convolution operation) to the acoustic signal VIN is changed from the impulse response H1 to the impulse response H2 during the generation of the reverberation signal VOUT. Therefore, the acoustic characteristic (frequency characteristic) of the reproduced sound of the reverberation signal VOUT changes from the characteristic corresponding to the impulse response H1 to the characteristic corresponding to the impulse response H2. A configuration in which each element of the arithmetic processing unit 12 is distributedly mounted on a plurality of integrated circuits, or a configuration in which an electronic circuit (DSP) dedicated to processing of the acoustic signal VIN realizes each element is also employed.

  The input device 16 is configured by an operator operated by a user for inputting an instruction to the reverberation imparting device 100. For example, the user appropriately operates the input device 16 to select the impulse response H1 before the change and the impulse response H2 after the change from the plurality of impulse responses H stored in the storage device 14. Further, the user inputs an instruction (hereinafter referred to as “change instruction”) for changing the impulse response H (H 1 → H 2) from the input device 16.

  As shown in FIG. 1, the arithmetic processing device 12 functions as a convolution operation unit 22 and a waveform synthesis unit 24. The convolution operation unit 22 performs a convolution operation between the acoustic signal VIN and the impulse response H. When a change instruction is given to the input device 16, the convolution operation unit 22 performs a convolution operation using the impulse response H1 before the change and the impulse response H2 after the change from the acoustic signal VIN to a plurality of reverberation signals R ( R1 to R4). Note that the method of generating the reverberation signal VOUT by the convolution calculation of the acoustic signal VIN and the impulse response H when the change instruction is not given is the same as the known technique. In the following description, specific functions and operations of the arithmetic processing unit 12 when a change instruction is given will be described mainly.

  1 synthesizes the reverberation signal VOUT by connecting a plurality of reverberation signals R (R1 to R4) along the time axis. Note that the processing by the convolution calculator 22 and the waveform synthesizer 24 may be executed in either the frequency domain or the time domain. When processing by the convolution operation unit 22 and the waveform synthesis unit 24 is executed in the frequency domain, processing (for example, Fourier transform) for converting the acoustic signal VIN and the impulse response H into the frequency domain, reverberation signal R and reverberation signal in the time domain A process for generating VOUT (for example, inverse Fourier transform) is executed at an appropriate time.

  FIG. 2 is a block diagram illustrating a specific configuration of the convolution operation unit 22 and the waveform synthesis unit 24. As shown in FIG. 2, the entire section P0 from the start point to the end point of the impulse response H1 before the change is divided into a part PA and a part PB along the time axis. The portion PA is a portion extending from the start point of the entire interval P0 (first sample of the impulse response H1) to a predetermined time length, and the portion PB is the end point of the entire interval P0 from the end point of the portion PA (last sample of the impulse response H1). ). Similarly, the entire section N0 from the start point to the end point of the impulse response H2 after the change is divided into a part NA having a predetermined length including the start point and a part NB following the part NA. For example, a section that includes abundant initial reflected sound is selected as the part PA or the part NA, and a section corresponding to the rear reverberant sound is selected as the part PB or the part NB.

  As shown in FIG. 2, the convolution calculation unit 22 includes a calculation unit 31, a calculation unit 32, a calculation unit 33, and a calculation unit 34. The computing unit 31 generates the reverberation signal R1 by convolving the acoustic signal VIN with the impulse response H1 (the entire section P0 composed of the part PA and the part PB). On the other hand, the calculation unit 32 generates the reverberation signal R2 by convolving only the portion PA of the impulse response H1 with the acoustic signal VIN. That is, the portion PB of the impulse response H1 is not used for the convolution calculation by the calculation unit 32. Similarly, the calculation unit 33 generates the reverberation signal R3 by convolving only the portion NA of the impulse response H2 (not using the portion NB) with the acoustic signal VIN, and the calculation unit 34 calculates the impulse response H2 to the acoustic signal VIN. A reverberation signal R4 is generated by convolving (all sections N0 composed of part NA and part NB).

  As shown in FIG. 2, the waveform synthesis unit 24 includes a synthesis unit 41, a synthesis unit 42, and a synthesis unit 43. The combining unit 41 connects the reverberation signal R1 generated by the calculation unit 31 and the reverberation signal R2 generated by the calculation unit 32 on the time axis. Similarly, the synthesis unit 42 connects the reverberation signal R2 and the reverberation signal R3 on the time axis, and the synthesis unit 43 connects the reverberation signal R3 and the reverberation signal R4 on the time axis. The signal connected by the waveform synthesizer 24 is output as the reverberation signal VOUT.

  FIG. 3 is a conceptual diagram for explaining the operations of the convolution operation unit 22 and the waveform synthesis unit 24. When the user gives a change instruction to the input device 16, the section S1, the section S2, and the section S3 are set to the acoustic signal VIN, for example, based on the time point of the change instruction. The section S2 is a section after the passage of the section S1, and the section S3 is a section after the passage of the section S2. The time length from the point of change instruction to the start point of each section S (S1, S2, S3) and the time length from the start point to the end point of each section S are predetermined values (for example, numerical values designated by the user from the input device 16). Set to

  First, a specific operation of the convolution operation unit 22 will be described. As shown in FIG. 3, the calculation unit 31 generates an impulse response H1 (all sections P0) for the section T1 including the section S1 and before the start of the section S1 (before the start point A1 of the section S1) in the acoustic signal VIN. Is used to generate a reverberation signal R1. The section T1 is a section from before the change instruction is given (for example, at the start of the operation of the convolution operation unit 22) to the time point tA2 after the passage of the section S1. On the other hand, the calculation unit 32 generates the reverberation signal R2 by convolving the portion PA of the impulse response H1 with respect to the section T2 including the start point A1 of the section S1 to the end point B2 of the section S2 in the acoustic signal VIN. The section T2 is a section from the time tA1 before the start of the section S1 to the time tB2 after the lapse of the section S2. As described above, the generation of the reverberation signal R1 by the calculation unit 31 (convolution of the impulse response H1) and the generation of the reverberation signal R2 by the calculation unit 32 (convolution of the portion PA of the impulse response H1) include the section S1. The processes are executed in parallel in the section from the time point tA1 to the time point tA2. Therefore, the reverberation signal R1 and the reverberation signal R2 overlap in the section S1.

  Further, as shown in FIG. 3, the calculation unit 33 reverberates by convolving the portion NA of the impulse response H2 with respect to the section T3 including the start point B1 of the section S2 to the end point C2 of the section S3 in the acoustic signal VIN. A signal R3 is generated. The section T3 is a section from the time tB1 before the start of the section S2 to the time tC2 after the passage of the section S3. Therefore, as shown in FIG. 3, the generation of the reverberation signal R2 by the calculation unit 32 and the generation of the reverberation signal R3 by the calculation unit 33 (convolution of the portion NA of the impulse response H2) are performed from the time point tB1 including the section S2. It is executed in parallel within the interval up to tB2. That is, the reverberation signal R2 and the reverberation signal R3 overlap in the section S2.

  Further, the calculation unit 34 generates the reverberation signal R4 by convolving the impulse response H2 (all intervals N0) with respect to the interval T4 including the interval S3 and after the passage of the interval S3 in the acoustic signal VIN. The section T4 is a section extending from the time tC1 before the start of the section T3 to after the passage of the section S3. Therefore, as shown in FIG. 3, the generation of the reverberation signal R3 by the calculation unit 33 and the generation of the reverberation signal R4 by the calculation unit 34 (convolution of the impulse response H2) are from the time point tC1 to the time point tC2 including the section S3. It is executed in parallel in the interval. That is, the reverberation signal R3 and the reverberation signal R4 overlap in the section S3.

  Next, a specific operation of the waveform synthesis unit 24 will be described. As shown in FIG. 3, the synthesizer 41 crossfades the reverberation signal R1 and the reverberation signal R2 within the section S1 so that the reverberation signal R1 smoothly transitions to the reverberation signal R2. That is, the synthesizing unit 41 continuously decreases the amplitude of the reverberation signal R1 from the start point A1 to the end point A2 of the section S1 (for example, multiplies by a coefficient that decreases from “1” to “0”), and the reverberation signal R2 While continuously increasing the amplitude (for example, multiplying by a coefficient increasing from “0” to “1”), the reverberation signal R1 and the reverberation signal R2 are added.

  Similar to the synthesis unit 41, the synthesis unit 42 crossfades the reverberation signal R2 and the reverberation signal R3 within the section S2 so that the reverberation signal R3 smoothly transitions from the reverberation signal R2 to the reverberation signal R3. The reverberation signal R3 and the reverberation signal R4 are cross-faded so that the transition from the R3 to the reverberation signal R4 is smoothly performed. As described above, the reverberation signal VOUT is generated by smoothly connecting the reverberation signals R by cross-fading, so that the reproduced sound of the reverberation signal VOUT has no discontinuity in the sections S1, S2, and S3. Is perceived by the listener as sound of a strong impression.

  Since the convolution operation unit 22 and the waveform synthesis unit 24 operate as described above, as shown in FIG. 3, the reverberation signal VOUT is changed from the reverberation signal R1 before the start of the section S1 to the reverberation signal R2 (time point A2 to time point). B1) and the reverberation signal R3 (time B2 to time C1), and then change to the reverberation signal R4 at the end point C2 of the section S3. That is, the impulse response H used to generate the reverberation signal VOUT is from the impulse response H1 (all intervals P0) to the portion PA of the impulse response H1 and the portion of the impulse response H2 from the start point A1 of the interval S1 to the end point C2 of the interval S3. The impulse response H2 (all intervals N0) is changed stepwise through NA. As shown in FIG. 3, in the acoustic signal VIN, the section T1 subject to convolution of the impulse response H1 and the section T4 subject to convolution of the impulse response H2 do not overlap on the time axis.

  In the above embodiment, the calculation unit 32 uses only the portion PA of the impulse response H1 in the interval from the time point tA1 to the time point tA2 where the calculation unit 31 performs the convolution calculation of the impulse response H1 (all intervals P0). Perform convolution operations in parallel. Similarly, in the interval from the time point tC1 to the time point tC2 where the calculation unit 34 performs the convolution calculation of the impulse response H2 (all intervals N0), the calculation unit 33 uses only the portion NA of the impulse response H2. Are executed in parallel. Further, in the section from time tB1 to time tB2, the convolution calculation (calculation unit 32) of the partial PA of the impulse response H1 and the convolution calculation (calculation unit 33) of the partial NA of the impulse response H2 are executed in parallel. The As described above, in this embodiment, it is necessary to execute the convolution operation for all sections P0 of the impulse response H1 and the convolution operation for all sections N0 of the impulse response H2 in parallel on the common section of the acoustic signal VIN. Therefore, as compared with the technique of Patent Document 1 illustrated in FIG. 10, there is an advantage that the calculation amount of the arithmetic processing device 12 is reduced when the impulse response H is changed (particularly, the sections S1, S2, and S3). is there.

  In the section from the end point A2 of the section S1 to the start point C1 of the section S3, the reverberation signal VOUT is generated by the convolution calculation of only a part (part PA or part NA) of the impulse response H. That is, the reverberant sound (part PB and part NB) of the impulse response H1 and the impulse response H2 is not used. However, since the reverberation signal VOUT in the section in which only the portion PA and the portion NA are used is in the process of changing the acoustic characteristics, the rear reverberation sound of the impulse response H is not added to the reverberation signal VOUT. The listener is hardly perceived by the listener.

<B: Second Embodiment>
Next, a second embodiment of the present invention will be described. In addition, about the element which is common in 1st Embodiment in each following form, the same code | symbol as the above is attached | subjected and each detailed description is abbreviate | omitted suitably.

  FIG. 4 is a block diagram of the convolution operation unit 22 and the waveform synthesis unit 24. As shown in FIG. 4, in the convolution operation part 22 of this embodiment, the operation part 33 of the first embodiment is omitted. The computing unit 34 generates the reverberation signal R4 by convolving the impulse response H2 (all intervals N0) with the acoustic signal VIN. Therefore, the impulse response H2 is not divided into a part NA and a part NB.

  The waveform synthesis unit 24 includes a synthesis unit 41 and a synthesis unit 42. The synthesizer 41 synthesizes (connects) the reverberation signal R1 and the reverberation signal R2 as in the first embodiment. The synthesis unit 42 synthesizes the reverberation signal R2 generated by the calculation unit 32 and the reverberation signal R4 generated by the calculation unit 34.

  FIG. 5 is a conceptual diagram for explaining the operations of the convolution operation unit 22 and the waveform synthesis unit 24. In response to the change instruction, the section S1 and the section S2 are set in the acoustic signal VIN. As shown in FIG. 5, the calculation unit 31 generates the reverberation signal R1 by the convolution calculation of the section T1 of the acoustic signal VIN and the impulse response H1 (all sections P0), and the calculation unit 32 performs the section of the acoustic signal VIN. The operation of generating the reverberation signal R2 by the convolution operation of T2 and the portion PA of the impulse response H1 is the same as that of the first embodiment.

  On the other hand, the calculation unit 34 generates the reverberation signal R4 by convolving the impulse response H2 (all intervals N0) into the interval T4 including the interval S2 and the passage of the interval S2 in the acoustic signal VIN. The section T4 is a section extending from the time tB1 before the start of the section S2 to after the passage of the section S2. As described above, the generation of the reverberation signal R2 by the calculation unit 32 and the generation of the reverberation signal R4 by the calculation unit 34 are executed in parallel in the section from the time point tB1 to the time point tB2, and therefore the reverberation signal R2 and the reverberation signal R4. And overlap in the section S2.

  As shown in FIG. 5, the synthesizing unit 41 connects the reverberation signal R1 and the reverberation signal R2 by the crossfade in the section S1 as in the first embodiment. On the other hand, the synthesis unit 42 crossfades the reverberation signal R2 and the reverberation signal R4 in the section S2 so that the reverberation signal R2 smoothly transitions to the reverberation signal R4. Therefore, the impulse response H used for generating the reverberation signal VOUT is from the impulse response H1 (all intervals P0) to the impulse response H2 (part PA) from the start point A1 of the interval S1 to the end point B2 of the interval S2. All sections N0) are changed in stages. As shown in FIG. 5, in the acoustic signal VIN, the section T1 in which the impulse response H1 is folded and the section T4 in which the impulse response H2 is folded do not overlap on the time axis.

  In the above embodiment, the calculation unit 32 is executed in parallel with the convolution calculation of the impulse response H1 (all intervals P0) by the calculation unit 31 and the convolution calculation of the impulse response H2 (all intervals N0) by the calculation unit 34. Therefore, it is not necessary to execute in parallel the convolution operation of the entire section P0 of the impulse response H1 and the convolution operation of the entire section N0 of the impulse response H2. Therefore, the same effect as the first embodiment is realized.

<C: Third Embodiment>
FIG. 6 is a block diagram of the convolution operation unit 22 and the waveform synthesis unit 24 in the third embodiment of the present invention. As shown in FIG. 6, in the convolution operation part 22 of this embodiment, the operation part 32 of the first embodiment is omitted. Further, the impulse response H1 is not divided into a part PA and a part PB. On the other hand, the waveform synthesizer 24 includes a synthesizer 41 that connects the reverberation signal R3 to the reverberation signal R1, and a synthesizer 42 that connects the reverberation signal R4 to the reverberation signal R3.

  FIG. 7 is a conceptual diagram for explaining the operations of the convolution operation unit 22 and the waveform synthesis unit 24. In response to the change instruction, the section S1 and the section S3 are set in the acoustic signal VIN. As shown in FIG. 7, the operation unit 31 generates the reverberation signal R1 from the section T1 and the impulse response H1 (all sections P0) of the acoustic signal VIN, and the operation unit 34 operates the section T4 and the impulse response of the acoustic signal VIN. The operation for generating the reverberation signal R4 from H2 (all intervals N0) is the same as in the first embodiment.

  The calculation unit 33 applies the portion NA of the impulse response H2 to the section T3 (section from the time tA1 before the start of the section S1 to the time tC2 after the lapse of the section S3) including the sections S1 and S3 in the acoustic signal VIN. A reverberation signal R3 is generated by convolution. As described above, since the generation of the reverberation signal R1 by the calculation unit 31 and the generation of the reverberation signal R3 by the calculation unit 33 are executed in parallel in the section (section S1) from the time point tA1 to the time point tC2. R1 and the reverberation signal R3 overlap in the section S1.

  As shown in FIG. 7, the synthesizer 41 crossfades the reverberation signal R1 and the reverberation signal R3 within the section S1 so that the reverberation signal R1 smoothly transitions to the reverberation signal R3. On the other hand, the synthesizing unit 42 connects the reverberation signal R3 and the reverberation signal R4 by crossfading within the section S3. Therefore, the impulse response H used to generate the reverberation signal VOUT is from the start point A1 of the section S1 to the end point C2 of the section S3, from the impulse response H1 (all sections P0) to the impulse response H2 (through the portion NA of the impulse response H2 ( All sections N0) are changed in stages. As shown in FIG. 7, the interval T1 in which the impulse response H1 is convoluted in the acoustic signal VIN and the interval T4 in which the impulse response H2 is convoluted do not overlap on the time axis.

  As described above, what is executed in parallel with the convolution calculation of the impulse response H1 (all intervals P0) and the impulse response H2 (all intervals N0) is the convolution calculation of the portion NA of the impulse response H2 by the calculation unit 33. Therefore, it is not necessary to execute in parallel the convolution operation for all sections P0 of the impulse response H1 and the convolution operation for all sections N0 of the impulse response H2. Therefore, the same effect as the first embodiment is realized.

<D: Fourth Embodiment>
FIG. 8 is a conceptual diagram for explaining the operation of the fourth embodiment of the present invention. As shown in FIG. 8, each section T (T1 to T4) of the acoustic signal VIN is set with the start point and end point of each section S (S1 to S3) to be crossfade by the waveform synthesizer 24 as end points. For example, the calculation unit 31 generates the reverberation signal R1 by the convolution calculation of the impulse response H1 only for the section T1 having the end point A2 of the section S1 as the end point (time tA2 in FIG. 3) in the acoustic signal VIN. That is, the convolution calculation of the impulse response H1 (all intervals P0) is not executed for the interval after the passage of the interval S1 (time point A2) in the acoustic signal VIN. Similarly, the calculation unit 34 generates the reverberation signal R4 by the convolution calculation of the impulse response H2 for only the section T4 starting from the starting point C1 of the section S3 in the acoustic signal VIN.

  Further, the calculation unit 32 generates a reverberation signal R2 by executing a convolution calculation of the portion PA of the impulse response H1 only for the section from the start point A1 of the section S1 to the end point B2 of the section S2 in the acoustic signal VIN. To do. That is, the convolution operation of the partial PA is not executed for the section of the acoustic signal VIN before the start of the section S1 (time A1) or after the section S2 (time B2) has elapsed. Similarly, the calculation unit 33 performs the convolution calculation of the portion NA of the impulse response H2 for only the section from the start point B1 of the section S2 to the end point C2 of the section S3 in the acoustic signal VIN, thereby obtaining the reverberation signal R3. Generate.

  In the above embodiment, since the convolution operation by the convolution operation unit 22 is executed only for the section necessary for the synthesis by the waveform synthesis unit 24 in the acoustic signal VIN, after the fade-out by the waveform synthesis unit 24 is completed. Sections (for example, time point A2 to time point tA2, time point B2 to time point tB2, time point C2 to time point tC2 in FIG. 3) and sections before the start of fade-in (for example, time point tA1 to time point A1, time point tB1 to time point B1, time point in FIG. Compared to the first embodiment in which the convolution operation is performed for tC1 to time C1), there is an advantage that the amount of calculation by the convolution operation unit 22 is reduced.

  In addition, although the aspect which deform | transformed 1st Embodiment was illustrated in the above, this form which performs the convolution calculation by the convolution calculating part 22 only for the area required for the production | generation of the reverberation signal VOUT among acoustic signals VIN is performed. This configuration is similarly applied to the second embodiment and the third embodiment.

<E: Fifth Embodiment>
FIG. 9 is a block diagram of the convolution operation unit 22 and the waveform synthesis unit 24 in the fifth embodiment of the present invention. As shown in FIG. 9, the calculation unit 31 of the convolution calculation unit 22 includes a convolution unit 312 and an addition unit 314. The convolution unit 312 generates the reverberation signal r1 by convolving only the portion PB of the impulse response H1 with the acoustic signal VIN. The adding unit 314 generates the reverberation signal R1 by adding the reverberation signal R2 generated by the arithmetic unit 32 and the reverberation signal r1 generated by the convolution unit 312. Since the reverberation signal R2 is generated by the convolution operation of the acoustic signal VIN and the portion PA of the impulse response H1, the reverberation signal R1 is an impulse response composed of the portion PA and the portion PB as in the first embodiment. This corresponds to a signal obtained by convolving H1 (all intervals P0) with the acoustic signal VIN.

  Similar to the calculation unit 31, the calculation unit 34 includes a convolution unit 342 and an addition unit 344. The convolution unit 342 generates the reverberation signal r4 by convolving only the portion NB of the impulse response H2 with the acoustic signal VIN. The adder 344 generates the reverberation signal R4 by adding the reverberation signal r4 to the reverberation signal R3 generated by the arithmetic unit 33 from the portion NA of the impulse response H2. Therefore, the reverberation signal R4 corresponds to a signal obtained by convolving the entire section N0 of the impulse response H2 with the acoustic signal VIN, as in the first embodiment.

  In the above embodiment, the object of the convolution operation in the operation unit 31 is reduced to the portion PB of the impulse response H1, and the object of the convolution operation in the operation unit 34 is reduced to the portion NB of the impulse response H2. Therefore, compared with the first embodiment in which all of the impulse responses (H1, H2) are used for the convolution calculation by the calculation unit 31 and the calculation unit 34, the calculation amount of the calculation unit 31 and the calculation unit 34 is reduced. There is an advantage.

  In addition, although the aspect which deform | transformed 1st Embodiment was illustrated in the above, the structure in which the calculating part 31 includes the convolution part 312 and the addition part 314 is applied similarly to 2nd Embodiment, and the calculating part 34 is The configuration including the convolution unit 342 and the addition unit 344 is similarly applied to the third embodiment. The fifth embodiment is also applied to the fourth embodiment.

<F: Modification>
Various modifications can be made to each of the forms exemplified above. An example of a specific modification is as follows. Two or more aspects may be arbitrarily selected from the following examples and combined.

(1) Modification 1
In each of the above embodiments, the amplitude of the reverberation signal R (R1 to R4) to be faded out or faded in is linearly and continuously increased or decreased. However, the amplitude of each reverberation signal R is curved (nonlinear). A crossfade that increases or decreases, or a crossfade that increases or decreases the amplitude of each reverberation signal R stepwise is also employed.

(2) Modification 2
In the above configuration, the impulse response H is changed in response to a change instruction from the user. However, the trigger for changing the impulse response H is arbitrary in the present invention. For example, a configuration in which data specifying the time point of change of the impulse response H and the impulse response H2 after the change in time series is sequentially obtained from the storage device 14 and used for changing the impulse response H is also suitable.

(3) Modification 3
In each of the above embodiments, the section extending from the starting point of the impulse response H (H1, H2) to the predetermined length is the part PA or the part NA, but the conditions for selecting the part PA or the part NA are changed as appropriate. For example, a configuration in which the portion PA and the portion NA are extracted starting from a time point delayed from the start point of the impulse response H (H1, H2) is also employed. That is, the part PA used by the calculation unit 32 and the part NA used by the calculation unit 33 need only be a part of the impulse response H (H1, H2), and the position and time length of the part PA or the part NA are defined in the present invention. Is optional.

It is a block diagram of the reverberation provision apparatus which concerns on 1st Embodiment of this invention. It is a block diagram of a convolution operation part and a waveform synthesis part in the first embodiment. It is a conceptual diagram for demonstrating operation | movement of the reverberation provision apparatus which concerns on 1st Embodiment. It is a block diagram of the convolution operation part and waveform synthesis part in 2nd Embodiment of this invention. It is a conceptual diagram for demonstrating operation | movement of the reverberation provision apparatus which concerns on 2nd Embodiment. It is a block diagram of the convolution operation part and waveform synthesis part in 3rd Embodiment of this invention. It is a conceptual diagram for demonstrating operation | movement of the reverberation provision apparatus which concerns on 3rd Embodiment. It is a conceptual diagram for demonstrating operation | movement of the reverberation provision apparatus which concerns on 4th Embodiment of this invention. It is a block diagram of the convolution operation part in 5th Embodiment of this invention. It is a conceptual diagram for demonstrating the prior art which changes an impulse response.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Reverberation imparting device, 12 ... Arithmetic processing device, 14 ... Memory | storage device, 16 ... Input device, 22 ... Convolution operation part, 24 ... Waveform synthesis part, 31, 32, 33, 34 ... Arithmetic unit 41, 42, 43 ... synthesizer, 312,342 ... convolution unit, 314,344 ... adder, VIN ... acoustic signal, VOUT ... reverberation signal, R (R1, R2, R3, R4) ... Reverberation signal, H ... Impulse response, H1 ... Impulse response before change, H2 ... Impulse response after change, PA, PB ... Impulse response part before change, NA, NB ... Change Later impulse response part.

Claims (10)

A first computing means for generating a first reverberation signal in which a first impulse response is convoluted in a section including the first section and the start of the first section of the acoustic signal;
A second reverberation signal is generated by convolving the first portion of the first impulse response in a section including the start point of the first section and the end point of the second section after the first section of the acoustic signal. A second computing means;
A third reverberation signal is generated by convolving the first portion of the second impulse response in a section including the start point of the second section and the end point of the third section after the second section of the acoustic signal. 3 computing means;
A fourth computing means for generating a fourth reverberation signal in which the second impulse response is convoluted in a section including the third section and after the passage of the third section in the acoustic signal;
First synthesizing means for crossfading the first reverberation signal and the second reverberation signal within the first interval so as to transition from the first reverberation signal to the second reverberation signal;
Second synthesizing means for crossfading the second reverberation signal and the third reverberation signal in the second interval so as to transition from the second reverberation signal to the third reverberation signal;
A reverberation imparting apparatus comprising: a third synthesizing unit that cross-fades the third reverberation signal and the fourth reverberation signal within the third interval so as to transition from the third reverberation signal to the fourth reverberation signal. A first computing means for generating a first reverberation signal in which a first impulse response is convoluted in a section including the first section and the start of the first section of the acoustic signal;
A second reverberation signal is generated by convolving the first portion of the first impulse response in a section including the start point of the first section and the end point of the second section after the first section of the acoustic signal. A second computing means;
A fourth calculation means for generating a fourth reverberation signal in which a second impulse response is convoluted in a section including the second section and after the passage of the second section in the acoustic signal;
First synthesizing means for crossfading the first reverberation signal and the second reverberation signal within the first interval so as to transition from the first reverberation signal to the second reverberation signal;
A reverberation adding device comprising: a second synthesizing unit that cross-fades the second reverberation signal and the fourth reverberation signal in the second interval so as to make a transition from the second reverberation signal to the fourth reverberation signal. A first computing means for generating a first reverberation signal in which a first impulse response is convoluted in a section including the first section and the start of the first section of the acoustic signal;
A third reverberation signal is generated by convolving the first portion of the second impulse response in a section including the start point of the first section to the end point of the third section after the first section of the acoustic signal. 3 computing means;
A fourth computing means for generating a fourth reverberation signal in which the second impulse response is convoluted in a section including the third section and after the passage of the third section in the acoustic signal;
First synthesizing means for crossfading the first reverberation signal and the third reverberation signal within the first interval so as to transition from the first reverberation signal to the third reverberation signal;
A reverberation imparting apparatus comprising: a second synthesizing unit that cross-fades the third reverberation signal and the fourth reverberation signal within the third interval so as to transition from the third reverberation signal to the fourth reverberation signal. The first calculation means includes
First convolution means for generating a reverberation signal by convolving a second part other than the first part of the first impulse response with the acoustic signal;
The first addition means for generating the first reverberation signal by adding the reverberation signal generated by the first convolution means and the second reverberation signal generated by the second calculation means. The reverberation imparting device according to claim 2. The fourth calculation means includes
A second convolution means for generating a reverberation signal by convolving a second portion other than the first portion of the second impulse response with the acoustic signal;
2. A second addition unit that generates the fourth reverberation signal by adding the reverberation signal generated by the second convolution unit and the third reverberation signal generated by the third calculation unit. The reverberation imparting device according to claim 3. The reverberation imparting device according to any one of claims 1 to 3, wherein the first calculation means generates the first reverberation signal only from a section before the end point of the first section in the acoustic signal. The reverberation imparting apparatus according to claim 1 or 2, wherein the second calculation means generates the second reverberation signal only from a section from the start point of the first section to the end point of the second section in the acoustic signal. The reverberation imparting apparatus according to claim 1 or 3, wherein the third calculation means generates the third reverberation signal only from a section from the start point of the second section to the end point of the third section in the acoustic signal. The reverberation imparting device according to any one of claims 1 to 3, wherein the fourth calculation means generates the fourth reverberation signal only from a section after the start point of the third section in the acoustic signal. A first arithmetic processing for generating a first reverberation signal in which a first impulse response is convoluted in a section including the first section and before the start of the first section of the acoustic signal;
A second reverberation signal is generated by convolving the first portion of the first impulse response in a section including the start point of the first section and the end point of the second section after the first section of the acoustic signal. A second calculation process;
A third reverberation signal is generated by convolving the first portion of the second impulse response in a section including the start point of the second section and the end point of the third section after the second section of the acoustic signal. 3 arithmetic processes,
A fourth calculation process for generating a fourth reverberation signal in which the second impulse response is convoluted in a section including the third section and after the passage of the third section in the acoustic signal;
A first synthesizing process for crossfading the first reverberation signal and the second reverberation signal within the first interval so as to transition from the first reverberation signal to the second reverberation signal;
A second synthesis process for crossfading the second reverberation signal and the third reverberation signal within the second interval so as to transition from the second reverberation signal to the third reverberation signal;
A program for causing a computer to execute a third synthesis process for crossfading the third reverberation signal and the fourth reverberation signal within the third interval so as to make a transition from the third reverberation signal to the fourth reverberation signal.

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