JPH0777982A - Effect adding device - Google Patents

Abstract

PURPOSE:To automatically and properly set effect addition characteristics according to the tempo of musical by automatically extracting tempo information from a musical performance signal and controlling characteristics of the effect adding device according to the tempo information. CONSTITUTION:A MIDI sequencer 5 generates a MIDI signal on the basis of stored MIDI data on music. A sound source system 6 receives the MIDI signal and generates musical sound signals of plural channels at the same time on the basis of the data. Plural sound source systems are connected in parallel and different MIDI channels are specified for the respective positions, so that different musical sounds can be generated by the sound source systems at the same time. A reverberation device 7 is connected to the sound source system 6 and inputs the MIDI signal from the MIST sequencer and adds reverberation effect to a musical sound. Its output is amplified by an amplifier 8 and sounded from a speaker 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an effect adding device, and more particularly to a so-called reverb device for adding reverberant sound.

[0002]

2. Description of the Related Art A reverb device is an effect adding device that adds reverberation to a musical tone. Conventionally, a mechanical reverberation adding device using a spring, a metal plate, or the like was used, but in recent years, a device that uses an analog delay element or a musical sound is A / D converted, and reverberation sound is generated by digital signal processing. Is proposed. These reverberation sound adding devices have a function of variably setting reverberation characteristics manually from a panel or the like.

[0003]

In recent years, the development of automatic musical instruments such as MIDI has been remarkable, and there are many opportunities for various musical compositions to be played by the automatic musical instrument. In these automatic performance devices, the tempo can be easily changed, and in many cases, the automatic performance is performed at a speed other than the original tempo of the music. When such an automatic performance device and a reverb device are combined, for example, if the reverberation time is lengthened, the musical tone corresponding to each note in a fast-tempo song will be buried in the reverberation sound, and the outline of the performance will be blurred. .
Therefore, the conventional reverb device has a problem that the operator needs to reset the reverberation characteristic when the tempo changes, even for the same music, for example.

An object of the present invention is to improve the above-mentioned problems of the prior art, and to provide an effect adding device in which the effect adding characteristics are automatically set appropriately in accordance with the tempo of the music. .

[0005]

FIG. 1 is a functional block diagram showing an outline of the present invention. The effect adding means 1 adds an effect to the inputted musical tone signal. The tempo measuring means 2 measures the tempo of a music piece at intervals such as a MIDI timing clock signal. The control signal generating means 3 generates a control signal for appropriately controlling the effect adding means based on the tempo information. That is, according to the present invention, a tempo measuring means for inputting a performance signal and outputting tempo information of a musical composition, a control signal generating means for generating a control signal based on the tempo information, and an input musical tone signal based on the control signal. And an effect adding means for applying an effect.

[0006]

According to the present invention, the tempo information is automatically extracted from the performance signal input from the outside by such means, and the characteristic of the effect adding device is controlled according to the tempo information. Even if the tempo is changed, the effect can always be added with optimum characteristics.

[0007]

Embodiments of the effect adding device to which the present invention is applied will be described in detail below. FIG. 2 is a block diagram showing the overall configuration of the automatic performance system including the effect adding circuit (reverb device) of the present invention. The MIDI sequencer 5 generates a MIDI signal based on the stored MIDI data of the music. In this MIDI signal, note-on (pronounced,
In addition to the chord 9x) and note-off (silence, chord 8x) signals, there are signals such as a timing clock (chord F8) which is a tempo signal output at a rate of 24 notes per quarter note.

The sound source system 6 receives the MIDI signal,
According to the data, musical tone signals of a plurality of channels are simultaneously generated. By connecting a plurality of sound source systems in parallel and assigning different MIDI channels to the respective devices, it is possible to simultaneously generate different musical sounds from the plurality of sound source systems. The reverb device 7 is connected to the tone generator system 6 and inputs a MIDI signal from a MIDI sequencer to add a reverb effect to a musical sound. This output is amplified by the amplifier 8 and the speaker 9
Pronounced from.

FIG. 3 is a block diagram showing the internal structure of the reverb device 7 of FIG. The input adjusting volume 10 adjusts the input signal level. The A / D converter 11 A / D converts the input musical tone signal. The DSP (Digital Signal Processor) 12 is a processor having a high-speed arithmetic function, and performs reverberation sound addition processing by a certain kind of filter arithmetic processing as described later. D / A converter 13 is DS
The output digital tone signal of P12 is D / A converted. The wet level volume 14 adjusts the reverberation level.
The dry level volume 15 adjusts the level of only the input signal to which no reverberant sound is added. The adder circuit 16 adds the input signal and the reverberant sound, synthesizes them, and outputs them.

The panel 17 is a switch or volume for instructing various modes and parameters to the reverb device,
And a display device for displaying modes and parameters. MIDI interface 18 is an asynchronous MID
I-serial signal is received, converted to parallel data, CP
Interrupt U19 and transfer. CPU19 is R
The entire device is controlled in accordance with the program stored in the OM 20, and a process of creating a control signal from the received MIDI signal is also performed as described later. Further, it has a built-in timer and can issue a timer interrupt at an arbitrarily set cycle. The ROM 20 stores a control program and various data tables. The RAM 21 is used as a work area of the CPU. The bus 22 connects each circuit in the device.

Next, the processing of the DSP will be described.
FIG. 4 is a functional block diagram showing the processing of the DSP 12 of the first embodiment. This block diagram has a configuration of a non-recursive digital filter. In FIG. 4A, a plurality of delay circuits 40, 41 and 42 delay the input signal by the set delay amounts D1 to Dn. The plurality of coefficient multiplying circuits G43, 44, 45 multiply the output of the delay circuit by a coefficient K or 0 based on control information Ta from the outside, as shown in the internal configuration of FIG. Multiple adders 4
Reference numerals 6 and 47 add the outputs of the coefficient multipliers.

FIG. 4B is a block diagram showing the internal structure of the coefficient multiplier G shown in FIG. The comparison circuit 48 is C
The control information Ta set from the PU 18 and the total delay amount from the delay circuit to which the coefficient multiplier is connected (D1 to D
If the total delay amount is smaller, 1 is output, and if not, 0 is output. The selector 49 outputs 0 when the control input is 0 and outputs a coefficient K when the control input is 1. The multiplier 50 multiplies the output from the delay circuit and the output from the selector 49 and outputs the result to the adder shown in FIG.

When the delay amount D of the digital filter as shown in FIG. 4 and the coefficient K by which each delay data is multiplied are appropriately set and the control information Ta is given, the total delay amount in each coefficient multiplication circuit is Ta. A circuit that is larger than 0 outputs 0, and a reverberation sound signal with a large delay amount is not generated. That is T
The reverberation time is controlled by a. The reverberation time can be controlled not only by changing Ta but also by changing the delay time D of the delay circuit or the coefficient K by which each delay data is multiplied. Also, let K be a large value,
By setting Ta to a small value, a so-called gate reverb effect can be applied. The gate reverb is an effect of adding a reverberant sound to, for example, a drum sound, and gate-off the sound in the middle of the reverberation to give a listener an unexpected feeling.

FIG. 5 is a functional block diagram showing the processing of the DSP 12 of the second embodiment. This block diagram has a configuration of a recursive digital filter. The filter is
The adder 30, a plurality of delay circuits 31, 32, 33 that delay the output signal of the adder 30 by a delay amount D, and a plurality of multipliers 34, 35, 3 that multiply the output of the delay circuit by a coefficient K
6, a plurality of adders 37, 3 for adding the outputs of the multipliers
8. A multiplier 39 that multiplies the added signal by a control parameter T and inputs the result to the adder 30 in order to control the amount of circulation.
It consists of The delay circuit can be configured in series as shown in FIG.

In the functional block diagram of FIG. 5, first, the cyclic amount parameter T is set to 0, and the delay amounts D1 to Dn are set such that the values increase in order. The smaller the delay amount is, the larger the coefficient K1 to Kn becomes. If set, gate 40
A reverberation sound is obtained at the input of, but a large amount of delay circuits, multipliers, and adders are required to increase the number and time of reverberations. Therefore, when the cyclic amount parameter T is set in the range of 0 <T <1, the reverberation sound is attenuated by T and circulates to the input side again, and a plurality of reverberation sounds are obtained corresponding to one delay circuit. Therefore, by properly selecting the parameters D, T, and K, reverberant sound having arbitrary characteristics can be obtained.

FIG. 6 is a functional block diagram showing the processing of the DSP 12 of the third embodiment. This embodiment is a combination of the first embodiment and the second embodiment, and has a configuration in which a multiplier 60 and an adder 61 are added to the circuit of FIG. In this embodiment, by appropriately selecting the parameters D, T, and K, the reverberation sound having an arbitrary characteristic can be obtained with a single filter from short-term to long-term.

Next, the operation of the CPU will be described. FIG. 7 is a flowchart showing the main processing of the CPU. When the power is turned on, in step S1, R
Initializes various control information areas in the AM and registers in the MIDI interface circuit. In step S2, a reset command is sent to the DSP, and the DSP 12
To initialize. In step S3, the states of the switches on the panel are scanned, and if there is a change in the state, the process proceeds to step S4 and the corresponding processing is performed. The tempo measurement is executed by an interrupt process described later.

FIG. 8 is a flow chart showing the processing at the MIDI signal reception interrupt and the timer interrupt. In this embodiment, a program-controlled counter is used to measure the cycle of the clock signal, that is, the tempo. FIG. 8B is a flowchart showing the processing at the time of the timer interrupt. In step S20, 1 is added to the counter for measuring the tempo (clock signal period), and the interrupt processing is ended. Figure 8 (a) shows MIDI
It is a flowchart which shows a signal reception interruption process. In step S10, it is checked whether or not the received MIDI signal is the timing clock signal (code F8). If it is any other signal, the reverb device does not need it and interrupt processing is terminated. If it is a signal, the process proceeds to step S11. In step S11, based on the value of the tempo measuring counter,
The filter control parameter T of the DSP is obtained by referring to the conversion table between the count value and the filter control parameter T of the DSP. In step S12, the obtained parameter T is set in the DSP, and the filter characteristic of the DSP is updated. In step S13, the tempo measurement counter is cleared and the measurement of the next cycle is started. By the above-described processing, the filter control parameter T of the DSP corresponding to the cycle is obtained every time the clock signal is received, and the characteristics of the DSP are updated. Therefore, the reverb characteristic corresponding to the tempo is always obtained.

FIG. 9 is an explanatory diagram showing an example of the contents of the conversion table between the count value and the filter control parameter T of the DSP. The graph of FIG. 9A shows a characteristic that the count value and the parameter T are offset by a predetermined value and are directly proportional to each other by a predetermined coefficient, and FIG.
The graph of shows the logarithmic characteristic or a characteristic close to it, in which the count value and the parameter T are offset by a predetermined value. A conversion table showing such characteristics is used to convert the count value of the tempo measuring counter into a control parameter T, which is set as the control parameter Ta or Tb of the filter shown in FIG. A reverb characteristic corresponding to the tempo can be obtained.

Although the embodiment has been described above, the following modifications are also possible. In the embodiment, the example in which the parameter T is obtained by the control of the CPU and set in the DSP has been shown. However, the signal corresponding to the clock signal from the CPU is
It is also possible to output to the SP, measure the tempo in the DSP, and obtain the parameter. Further, the count value of a hardware counter that counts a constant clock signal may be latched by the clock signal output from the CPU, the counter may be reset, and the latched count result may be fetched into the DSP.

As the tempo signal, 24 per quarter note
In addition to the timing clock (chord F8) which is a tempo signal output at a rate of 48, a timing clock (D at a rate of 48 per quarter note) (D
Various types such as INSYNC etc. are available,
It is necessary to change the set value of the timer that counts up the counter according to the type of clock signal.

In the embodiment, the filter is used as a reverberation signal generator, and its frequency characteristic should be designed to be as flat as possible, but conversely, for example, a high band or a low band is emphasized. Alternatively, it is possible to provide a frequency characteristic that passes or blocks only a specific frequency band. By doing so, it is possible to change the timbre of the reverberation sound. In the present application, the reverb is described as the embodiment, but the present invention can be applied to various effect adding devices such as a vibrato, a tremolo, a growl, and a pan, in addition to the reverb.

[0023]

As described above, according to the present invention, it is possible to add an appropriate effect according to the tempo of a music piece.

[Brief description of drawings]

FIG. 1 is a functional block diagram showing an outline of the present invention.

FIG. 2 is a block diagram showing the configuration of the entire automatic performance system.

FIG. 3 is a block diagram showing an internal configuration of a reverb device.

FIG. 4 is a functional block diagram showing the processing of the DSP of the first embodiment.

FIG. 5 is a functional block diagram showing the processing of the DSP of the second embodiment.

FIG. 6 is a functional block diagram showing the processing of the DSP of the third embodiment.

FIG. 7 is a flowchart showing a main process of a CPU.

FIG. 8 is a flowchart showing interrupt processing of a CPU.

FIG. 9 is an explanatory diagram showing the contents of a control parameter conversion table.

[Explanation of symbols]

1 ... Effect adding means, 2 ... Gate means, 3 ... Gate signal generating means, 5 ... MIDI sequencer, 6 ... Sound source system,
7 ... Reverb device, 8 ... Amplifier, 9 ... Speaker

Claims (3)

[Claims] 1. A tempo measuring means for inputting a performance signal and outputting tempo information of music, a control signal generating means for generating a control signal based on the tempo information, and an effect on an input musical tone signal based on the control signal. An effect adding device comprising: an effect adding means for applying an effect. 2. The effect adding device according to claim 1, wherein the effect adding device is a reverberation adding device that controls the duration of the reverberation sound according to the control signal. 3. The reverberation adding means comprises a digital filter, and controls at least one of a delay amount, a coefficient of each delay data, and a cyclic coefficient according to the control signal. The effect adding device according to claim 2.