JPH04301898A - Musical sound signal generating device - Google Patents

Abstract

PURPOSE:To produce musical sounds having the natural change with time without noise or the unnatural change and to reproduce sounds from a waveform memory for a desired time by performing the cross fade control of the output from a waveform generating part and that from a loop circuit. CONSTITUTION:A key-on pulse KON, a key code KC, touch data TOUCH, and timbre data TC are inputted to a cross fade coefficient generating part 14. A cross fade coefficient A is outputted as a multiplier to a multiplier 5, and a cross fade coefficient B is outputted as a multiplier to a multiplier 13. The multiplier 13 multiplies a loop gain G outputted from a loop gain data generating part 12 and the cross fade coefficient B and outputs a multiplication result B.G to a multiplier 8. The output of a waveform generating part 4 is multiplied by the coefficient A in the multiplier 5, and the result is outputted to an adder 9. The output of a loop circuit 20 is multiplied in the multiplier 8 by the coefficient B.G gradually increased from o to G, and the result is outputted to the adder 9, thus realizing the cross fade control.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a musical tone signal generating apparatus, and more particularly to a musical tone signal generating apparatus capable of generating a musical sound waveform that changes naturally over time.

0002

2. Description of the Related Art Conventionally, a waveform memory in which a desired musical sound waveform is stored in an analog or digital manner is used, and the stored contents are repeatedly read out from the waveform memory at a speed proportional to the frequency of the musical sound to be generated. There is a musical tone signal generator that generates a musical tone signal. In addition, in order to generate musical tones with more variety, a musical sound waveform is added to the input terminal of a filter having desired frequency characteristics, and the musical sound waveform appearing at the output terminal of the filter is delayed by one cycle, and then returned to the input terminal of the filter. There is a musical tone signal generating device that forms a loop circuit so that a musical sound waveform circulates through a filter in such a way that the musical waveform is added to the filter, and extracts a sequentially changing musical waveform from such a loop circuit. In particular,
No. 8679 discloses an electronic musical instrument that uses a selector to initially use a musical sound waveform read from a waveform memory, and after a delay time of a loop circuit, switches to the musical sound waveform read from the loop circuit.

Furthermore, in Japanese Patent Publication No. 58-48109,
An electronic musical instrument is disclosed in which a musical sound waveform is obtained by mixing output data from a waveform memory and output data from a loop circuit at an appropriate mixing ratio.

0004

[Problem to be solved by the invention] Japanese Patent Publication No. 58-5867
The method No. 9 does not take into account the continuity of the waveform when switching the output musical waveform, so it may generate noise or
It may cause unnatural changes. In addition, special public service
In the method of No. 109, the waveform from the waveform memory is output as is only within the delay time (shift register) of the loop circuit, and it is not possible to output only the musical sound waveform from the waveform memory for a longer time. . For example, it is not possible to reproduce the waveform memory as it is as part of the attack waveform.

[0005] In view of the above-mentioned problems in the conventional example, the present invention makes it possible to generate musical tones that change naturally over time without producing noise or unnatural changes, and also to reproduce from a waveform memory for a desired length of time. The purpose of the present invention is to provide a musical tone signal generating device that can generate a musical tone.

[0006]

[Means for Solving the Problems] In order to achieve this object, a musical tone signal generating device according to the present invention includes a waveform generating means for generating a musical sound waveform for at least one period, and a musical tone signal generating means for generating a musical sound waveform for at least one cycle, a first multiplier that multiplies the waveform output by a first multiplier that gradually decreases; and an addition means that receives the output of the first multiplication means as one input; a loop means including a filter means for changing the output of the adding means, a delay means for delaying the musical sound waveform by one cycle, and a second multiplication means for multiplying by a gradually increasing second multiplier; is characterized in that it is used as a waveform for generating musical tones.

In particular, it is preferable that the time for gradual decrease in the multiplier in the first multiplication means and the time for gradual increase in the multiplier in the second multiplication means are variable.

[0008]

[Operation] The first multiplication means and the second multiplication means:
The output from the waveform generating means and the output from the loop means are subjected to so-called cross-fade control. This provides a natural musical tone that changes over time. In particular, if you set the time to start the crossfade (time to keep the multiplier of the first multiplication means at "1" and the multiplier of the second multiplication means at "0"), for example, the attack waveform It is possible to reproduce the waveform memory as it is and then use the output from the loop circuit under natural changes over time.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of a musical tone signal generating apparatus according to an embodiment of the present invention. This musical tone signal generation device includes a keyboard 1, switches 2 for specifying timbre, a control section 3, a waveform generation section 4, a delay circuit 6, a filter 7, a delay time data generation section 10, a filter coefficient generation section 11, and a loop gain. Data generator 12, crossfade coefficient generator 1
4, multipliers 5, 8, and 13, and an adder 9.

The control unit 3 detects the depression of a key on the keyboard 1,
The key-on pulse KON, the key code KC of the pressed key, and the touch data TOUCH are output. Further, the control section 3 outputs tone color data TC in response to the operation of the tone color specifying switch 2. The control section 3 has a MIDI interface.

The waveform generator 4 includes a waveform memory and a reading circuit therein, and sequentially reads and outputs waveform data WAVE from the waveform memory in response to a predetermined clock pulse φ. The waveform generator 4 inputs the key-on pulse KON, the key code KC, the touch data TOUCH, and the tone data TC, and sequentially reads and outputs the waveform data WAVE according to these input data. The waveform generating section 4 includes at least one
A device capable of generating a waveform corresponding to a period in an analog or digital manner, for example, a device that stores and reproduces musical tone signals using the PCM method is used. Output data WA of waveform generator 4
VE is added to the adder 9 via the multiplier 5 (first multiplication means).
Enter.

Adder 9, delay circuit 6, filter 7, and multiplier 8 are loop circuits (delay + feedback circuit)
It constitutes 20. The output data of the adder 9 is input to the delay circuit 6, and is output after being delayed for a predetermined time. As the delay circuit 6, for example, a shift register is used that stores one cycle of output data from the waveform generator 4 and outputs the data while shifting it in accordance with the clock pulse φ. The output of the delay circuit 6 is input to a filter 7. The musical sound waveform data is
Each time it loops through this loop circuit 20, it passes through the filter 7, and is thereby sequentially changed. In this way, complex musical tones can be formed. The output of the filter 7 is input to an adder 9 via a multiplier 8 (second multiplication means). Adder 9 adds the output from multiplier 8 and the output from multiplier 5. The addition result is again input to the delay circuit 6 and looped through the loop circuit 20. Also adder 9
The addition result is output as output data of this musical tone signal generator.

The delay time data generating section 10 inputs the key-on pulse KON and the key code KC, and outputs the delay circuit 6.
The delay time data DLY is output toward. The delay time data DLY defines the delay time of the delay circuit 6. Further, the filter coefficient generating section 11 includes a key-on pulse KON,
Input the key code KC, touch data TOUCH and tone data TC, and send the filter coefficient F to the filter 7.
Output LT. The filter coefficient FLT defines the frequency characteristics and phase characteristics of the filter 7. These parameters DLY and FLT define how the musical tone changes in the loop circuit 20.

The loop gain data generating section 12 generates key-on pulse KON, key code KC, and touch data TOU.
CH and tone data TC are input, and a loop gain G (0≦G≦1) is output to the multiplier 13. The loop gain G corresponds to the final target level when looping the musical sound waveform in the loop circuit 20. That is, as will be described later, the output of the waveform generator 4 and the output of the loop circuit 20 are cross-faded, the level of the output data of the waveform generator 4 gradually decreases, and the level of the output data of the loop circuit 20 gradually increases. The target level of the output data of the loop circuit 20 in such cross-fade control is defined by the loop gain G.

[0016] The cross-fade coefficient generating section 14 generates a key-on pulse KON, a key code KC, and touch data TOU.
CH and tone data TC are input, and cross-fade coefficients A and B for performing cross-fade control are output. The crossfade coefficient A starts from "1" and increases to "0".
'', and is output to the multiplier 5 as the multiplier. The cross-fade coefficient B is a coefficient that starts from "0" and gradually increases to "1", and is output to the multiplier 13 as a multiplier. The multiplier 13 multiplies the loop gain G output from the loop gain data generator 12 by a cross-fade coefficient B that gradually increases from "0" to "1", and directs the multiplication results B and G to the multiplier 8. Output. This multiplication result B・G starts from "0" and becomes "
This value becomes the multiplier of the multiplier 8.

From the above, the output of the waveform generator 4 is transmitted to the multiplier 5.
, it is multiplied by a coefficient A that gradually decreases from "1" to "0" and is output to the adder 9. Also, loop circuit 2
The output of 0 is multiplied by a coefficient B.G that gradually increases from "0" to "G" in the multiplier 8, and is output to the adder 9. This achieves cross-fade control. FIG. 2 shows an example of changes in cross-fade coefficients A and B over time. In this example, the cross-fade coefficient A maintains "1" until a predetermined time t1, gradually decreases at a constant rate from time t1 to t2, reaches "0" at time t2, and thereafter remains "0". do. The cross-fade coefficient B holds "0" until a predetermined time t1, and from time t1 to t
It gradually increases at a constant rate up to 2, and after reaching "1" at time t2, it remains at "1". In other words, the coefficient B is B=(1-A).

When the cross-fade coefficients A and B exhibit such a temporal change, the output of the musical tone signal generator of FIG. 1 is as follows. First, suppose that any key on keyboard 1 is pressed and a musical tone signal is output from time t=0.
Since the coefficients A=1 and B=0 from time t=0 to t1, the output WAVE from the waveform generator 4 is outputted via the multiplier 5 and the adder 9. Next, time t=t1 ~t
2, coefficient A gradually decreases from "1" to "0", and coefficient B gradually increases from "0" to "1" (the multiplier of multiplier 8 is "0").
The output from the waveform generator 4 and the output from the loop circuit 20 are mixed in the adder 9 at a mixing ratio according to these coefficients and output. Then, after time t=t2, the coefficients A=0 and B=1 (the multiplier of the multiplier 8 is "G"), so the output from the loop circuit 20 is outputted via the multiplier 8 and the adder 9. Ru.

FIG. 3 shows an example in which the output from the waveform generator 4 is used during the attack period of the output musical sound waveform. In the example of FIG. 3, time t1 in FIG. 2 is set to the end of the attack period, and time t2 is set to the middle of the first loop process. As a result, during the attack period, the output from the waveform generator 4 with good reproducibility is used as is, and after the attack period, the proportion of the output from the loop circuit 20, which is rich in variation, is gradually increased, and eventually the loop naturally occurs. The output from the circuit 20 can be used as the main output. Such control is suitable for synthesizing musical tones in which the attack plays an important role as a factor in determining the timbre, such as piano tones, and whose attenuation is relatively gentle.

FIG. 4 shows an example of cross-fading based on the zero-cross point of the waveform. In the example of FIG. 4, time t1 in FIG. 2 is set as the time when the waveform first crosses zero, and time t2 is set as the time of the next zero-cross. As a result, the output from the waveform generating section 4 with good reproducibility is initially used as it is until the zero crossing, and from then on, a crossfade is executed until the next zero crossing point, and finally the output from the loop circuit 20 is naturally used. You can make it the main focus.

Although the cross-fade coefficients A and B change complementary to each other in FIGS. 2 to 4 above, the coefficients A and B may be changed independently over time. Further, other parameters such as filter coefficients may be changed in accordance with changes in cross-fade coefficients A and B. Furthermore, it is preferable that the times t1 and t2 at which the coefficients A and B change can be changed as appropriate.

[0022]

[Effects of the Invention] As explained above, according to the present invention, since the output from the waveform generating means and the output from the loop means are cross-fade controlled, noise and unnatural changes are not caused. It is possible to generate musical tone signals that have natural changes over time. Furthermore, it is possible to perform reproduction from the waveform generating means for a desired time.

[Brief explanation of the drawing]

[Figure 1] Block configuration diagram of a musical tone signal generator according to an embodiment

[Figure 2] Graph showing an example of time changes in crossfade coefficients A and B

[Figure 3] Graph showing time changes when using the output from the waveform generator during the attack period

[Figure 4] Graph showing time changes when crossfading based on the zero-cross point of the waveform

[Explanation of symbols]

1...Keyboard, 2...Switches, 3...Control unit, 4...Waveform generation unit, 6...Delay circuit, 7...Filter, 10...Delay time data generation unit, 11...Filter coefficient generation unit, 12...Loop gain data generation Section, 14... Cross-fade coefficient generation section,
5, 8, 13...multiplier, 9...adder.

Claims (2)

[Claims] 1. Waveform generating means for generating a musical sound waveform for at least one cycle; and first multiplier means for multiplying the waveform output generated by the waveform generating means by a first multiplier that gradually decreases. , an addition means whose one input is the output of the first multiplication means, the addition means, a filter means for changing the musical sound waveform, and one of the musical sound waveforms.
a delay means for providing a delay of one cycle; and a second delay means for gradually increasing the delay time.
a second multiplication means for multiplying by a multiplier, and an output of the addition means is used as a waveform for generating a musical tone. 2. The musical tone signal generating device according to claim 1, wherein the time for gradual decrease of the multiplier in the first multiplication means and the time for gradual increase in the multiplier in the second multiplication means are variable.