JPH083716B2 - Waveform synthesizer - Google Patents

Description

TECHNICAL FIELD The present invention relates to a waveform synthesizer used in an electronic musical instrument or the like.

[Background of the Invention]

Conventionally, it has been practiced to store digital information expressing a waveform in a memory and access the digital information at a speed according to a pitch to be generated to reproduce the original waveform. In this case, in the memory, for example, PCM (Pulse Code Modulatio
The waveform represented by n) is generally stored for the entire period from the beginning to the end.

By the way, when storing waveform information using such PCM technology, it is common to store it in, for example, a ROM using one selected as a specific sound source waveform by the manufacturer of the electronic technology. However, it was not versatile because the performer could not make various changes to obtain the desired waveform.

Further, for example, a user records natural sound through a microphone or the like and uses this as a sound source waveform to generate a musical tone signal of an arbitrary scale tone. The generated waveform could not be changed and was not interesting.

[Object of the Invention]

The present invention has been made to solve the above-mentioned drawbacks, and an object thereof is to provide a versatile waveform synthesizer.

[Outline of Invention]

The gist of the present invention is to input waveform information expressing a waveform of a predetermined cycle, and further input envelope information for this waveform to generate waveform information expressing a waveform from the beginning to the end of the waveform from this information. In the storage means, and further, digitally multiplies the newly input envelope information and the already-stored full-waveform information to generate a full-waveform of a new timbre, which is again stored in the storage means. When further storing, it is controlled so that all waveforms can be stored in the entire storage area without excess or deficiency.

Example of Invention

Examples of the present invention will be described below. FIG. 1 is a first embodiment showing the principle of the present invention, in which 1 is
It is an input device, and various keyboard devices or character and graphic input devices can be used. From this input device 1,
Waveform information indicating one cycle of the waveform is input to the memory 2, and envelope information indicating an envelope is input to the memory 3.

Now, the memory 2 is divided into M and one cycle of the waveform is M.
It is represented by sample points, and the crest value of each sample point is stored as digital information.
Similarly, the memory 3 is divided into N, and the envelope that determines the volume is represented by N sample points and stored by digital information.

Reference numeral 4 in the figure denotes a waveform synthesizing unit, which outputs waveform information obtained by synthesizing the information read from the memories 2 and 3 by an operation such as multiplication and supplies the waveform information to the adder 5. The output of the adder 5 is supplied to the memory 6.

The memory 6 is L-divided, and stores and stores the waveform information of the entire period from the beginning of the waveform to the end of the waveform by using L sample points. Then, the waveform information stored in the memory 6 is accessed and sent to the audio device, so that the pitch tone is generated.

The output of the memory 6 is fed back to the waveform synthesizer 4 via the switch 7. That is, the waveform information once stored in the memory 6 is multiplied by the envelope information stored in the memory 3 to newly obtain waveform information from the beginning to the end of the waveform, and the waveform information is again stored in the memory 6.
Can be stored in.

The output of the memory 6 is supplied to the adder 5 via the switch 8.

That is, the waveform information newly output from the waveform synthesizing unit 4 is added and synthesized to the waveform information representing all the waveforms from the beginning to the end of the waveform stored in the memory 6,
Waveform information expressing all waveforms from the beginning to the end of a new waveform obtained as a result can be written in the memory 6.

Next, the operation of FIG. 1 will be described with reference to FIG.

First, one cycle of waveform information and envelope information are stored in the memory 2 and the memory 3, respectively, by operating the input device 1. Then, the frequency f which determines the cycle of the waveform of the memory 2 is designated. The waveform synthesizing unit 4 multiplies these two pieces of information, successively calculates waveform information at the sampling frequency fsamp, and sends it to the memory 6.

By the way, this waveform synthesis is equivalent to performing the processing expressed by the following equation.

Here, i = 0 to L-1, and the i-th value of each of the memories 2, 3, and 6 is set to W [i-1], e [i-1], t [i-1].
And% represents the remainder of integer division.

That is, Represents the remainder when is divided by M.

Therefore, the memory 2 is repeatedly accessed to output the waveform information, is multiplied by the envelope information output from the memory 3, and new waveform information is generated from the waveform synthesizing unit 4 and written in the memory 6.

Therefore, by the above processing, the waveform information expressing all the waveforms from the beginning to the end of the waveform can be obtained from the waveform information and the envelope information of one cycle.

Next, a description will be given of synthesizing the waveform information stored in the memory 6 and the waveform information obtained by the same processing as above to calculate new waveform information.

That is, at this time, when the switch 8 is closed, the waveform information t ′ [i] calculated by the information obtained from the memories 2 and 3 and the waveform information t [i] previously stored in the memory 6 are stored. Waveform information obtained by summing and, that is, the processing represented by the following equation is stored in the memory 6.

Therefore, as is clear from the above description, it is possible to obtain an arbitrary waveform by repeating a plurality of waveforms obtained by envelope-multiplying the arbitrary waveform by repeating this process.

Therefore, for example, by changing the waveform to be stored in the memory 2 to the fundamental wave of the sine wave, the second harmonic, the third harmonic, and so on, and storing the corresponding envelope in the memory 3 independently. Thus, it is possible to obtain a sine wave synthesizing livelihood synthesizer in which the percentage of harmonic components changes with time.

In this way, it is possible to easily obtain the waveform information of the musical tone whose tone color changes with time.

Then, the process of multiplying the waveform information stored in the memory 6 by a completely different envelope will be described. That is, the waveform information t ″ [i] stored in the memory 6 is opened by opening the switch 8 and closing the switch 7.
Is supplied to the waveform synthesizing unit 4, and is multiplied by the envelope image e ″ [i] stored in the memory 3 in the waveform synthesizing unit 4.

 That is, the processing is expressed by the following equation.

t [i] = t ″ [i] × e ″ [i] As described above, the waveform information once stored in the memory 6 from the beginning to the end of the waveform is multiplied by the envelope information to obtain a different envelope. It is possible to calculate the waveform information that the user has.

Next, a second embodiment in which the principle circuit configuration shown in FIG. 1 is realized by using a concrete digital circuit will be described.

The memories 12, 13, 16 correspond to the memories 2, 3, 6 of the first embodiment, and the multiplier 14 is added to the waveform synthesizing unit 4 of the first embodiment.
Reference numeral 15 corresponds to the adder 5 of the first embodiment, and gates 17 and 18 correspond to the switches 7 and 8 of the first embodiment. The gate opening / closing signal g ₁ is applied to the gate 17, and the gate opening / closing signal g ₂ is applied to the gate 18.

The memories 12 and 13 store the waveform information and the envelope information supplied from the input device (not shown).
The address counters 19 and 20 specify the respective addresses, and the outputs from the programmable frequency dividers 21 and 22 sequentially increment the addresses. Then, a value for determining a frequency division ratio, which will be described later, is set to the programmable frequency dividers 21 and 22, the basic clock φ generated by the basic clock generator 23 is counted, and its carry output is It becomes the increment signal of the counters 19 and 20.

In addition, there is a latch 24 in front of the memory 16 and an adder 15
Output is latched. The address of the memory 16 is designated by the address counter 25, which receives the carry signal supplied from the programmable frequency divider 26 and sequentially increments it to generate and output the address signal.

That is, the programmable frequency divider 26 is preset with a value that determines the frequency division ratio, as will be described later, and counts the basic clock φ generated by the basic clock generator 23 to generate a carry output corresponding to the address. It serves as a count input to the counter 25 and also serves as a read command signal for the latch 24.

When the operation of the circuit shown in FIG. 3 is started, the start signal START is given and the basic clock generator 23
Address counter 19,20,
The clear signal CLR is given to 25 and the contents are initialized. Then, a read / write signal R / W is applied to the memories 12, 13, 16 according to their operating states, and read / write is controlled to be switched.

Further, when the carry signal is output from the address counter 25, it means that all the processes have been completed, so that it is applied to the basic clock generator 23 as a stop signal STOP. As a result, the basic clock φ is no longer output from the basic clock generator 23, and the operation ends.

Therefore, because of such a configuration, in this embodiment, the waveform information for one cycle is first input to the memory 12, and the envelope information is input to the memory 13. In that case, set a predetermined value, for example, 1 to the programmable frequency divider 21, and input waveform information one after another, or set a predetermined value, for example, 1 to the programmable frequency divider 22, and input envelope information one after another. Good.

Then, thereafter, from the information stored in the two memories 12 and 13, waveform information expressing all the waveforms from the beginning to the end of the waveform is generated and written in the memory 16. At this time, the gate signal g ₁ is given to the gate 17 so that the output of the memory 12 is given to the multiplier 14, and for the sake of simplicity, the memory lengths M, N of the memories 12, 13, 16 are now taken. , L is a power of 2. Then, at that time, for example, the following values are set in the programmable frequency dividers 21, 22, and 26 in advance. That is, the value 1 is set in the programmable frequency divider 21, and the value is set in the programmable frequency divider 22. Is set, and the programmable frequency divider 26 is set to the value fsamp / f. Therefore, the corresponding address counter 1
A count command is given to 9,20,25 when the basic clock φ is counted the number of times the programmable frequency dividers 21,22,26 are set.

Therefore, after the start signal START is given, the memories 12 and 13 are respectively accessed at the corresponding speeds, which are multiplied by the multiplier 14 and then latched in the latch 24 via the adder 15. Therefore, the latch 24 latches the applied data when the output signal from the programmable frequency divider 26 arrives, and then writes it in the memory 16.

Therefore, the waveform information representing all the waveforms from the beginning to the end of the waveform is sequentially written in the memory 16. The operation ends when the carry signal is output from the address counter 25.

Next, for the waveform information once written in the memory 16,
A case will be described in which different waveform information is calculated again and addition is performed. That is, at that time, the information of one cycle of the new waveform and the envelope information are set in the memories 12 and 13 in advance, and then both information are multiplied in the same manner as above to generate new waveform information. , This time, the gate signal g ₂ is given to the gate 18 to open it, and the pre-stored waveform information accessed and output from the memory 16 is added to the adder 15
To the latch 24, and the output from the multiplier 14 is added to synthesize the output.

Therefore, in this memory 16, the previously written waveform information is sequentially read, and new waveform information is sequentially written in the same memory area. Therefore, when the carry signal is output from the address counter 25, the new waveform information obtained by the synthesis is written in the memory 16.

Next, a case where the waveform information written in the memory 16 is newly multiplied by envelope information will be described. At this time, the gate signal g ₁ is applied to the gate 17 so that the output of the waveform memory 16 is supplied to the multiplier 14, and the output of the memory 13 storing the envelope is multiplied by the multiplier 14. To do.

At this time, the programmable frequency dividers 22 and 26 are
For example, the values L / N and 1 may be given to operate. As a result, the waveform information stored in the memory 16 is read out,
New envelope information is added, new waveform information is generated, and it is written in the memory 16 again.

As described above, in this embodiment, it is possible to obtain the same processing result as that of the first embodiment by using the digital circuit.

Next, a third embodiment of the present invention will be described. That is,
In this embodiment, the same operation is performed by the calculation processing of an electronic computer such as a personal computer, and as shown in FIG.
The personal computer 30 includes an electronic keyboard musical instrument 40 and a keyboard 32 and a digitizer 33 as an input device 31. That is, the keyboard 32 has a plurality of keys for inputting various commands and data, and the digitizer 33 is, for example, a waveform diagram or an envelope diagram drawn on paper placed thereon. By operating the operation 33-1, it is possible to input while tracing the figure on the paper.

An input device for inputting such two-dimensional coordinate information may be a digitizer, a mouse, a light pen, a trackball, or the like.
It can also be input by writing a waveform diagram on the CRT34 with a light pen or the like.

The personal computer 30 also includes a CPU (central processing unit) 35, and the CPU 35 controls all operations. In addition, although not shown in FIG. 4, there is a memory such as a floppy disk, a cassette tape, a ROM / RAM package (indicated by reference numeral 36 in FIG. 5 described later).
The electronic keyboard musical instrument 40 connected to the personal computer 30 is provided with a keyboard 41, a speaker 42, etc. on the outer surface thereof, and the waveform information obtained as a result of the arithmetic processing by the personal computer 30 is transferred and stored. It will be. Therefore, in the electronic keyboard instrument 40, the waveform information is accessed at a speed according to the scale frequency to generate the musical tone.

FIG. 5 shows a circuit configuration of the device shown in FIG. 4. As described above, in the personal computer 30, the input device 31, the CRT 34, and the CPU 3 connected to the bus line BUC are provided.
5. There is a memory 36, and from the waveform information and the envelope information input into the CPU 35, the same processing as in the first and second embodiments described above is performed by software, and all waveforms from the beginning to the end of the waveform are output. Is generated, and the waveform information is sent to the CPU 43 inside the electronic keyboard musical instrument 40 via the interface (I / O) circuit 37.

In the electronic keyboard instrument 40, the CPU 43 controls all operations and stores the waveform information transferred from the personal computer 30 in the waveform memory 44.

Then, the CPU 43 detects the performance of the keyboard 41 and accesses the waveform memory 44 at a speed according to the key depression. Then, the waveform information read from the waveform memory 44 is converted into an analog signal by the acoustic device 45, appropriately filtered, amplified, and then supplied to the speaker for sound emission.

The first to third embodiments of the present invention have been described above in detail, but there are the following modifications.

That is, in the above embodiment, 1
Although the waveform information of the cycle is stored, this is not limited to one cycle, and may be a waveform of a plurality of cycles or a waveform of a half cycle or the like. The waveform from the beginning to the end of the waveform may be generated according to the envelope information based on the waveform information.

Further, in the above embodiment, the waveform information of a predetermined cycle is manually set in the apparatus in advance, and waveform information for all periods from the beginning to the end of this waveform information and envelope information is generated. New waveform information obtained by the same procedure is added and combined with the waveform information to obtain a waveform different from the original waveform, and a waveform whose harmonic component changes with time. New waveform information is input by manual input, etc., to the waveform information that represents the waveform of all the periods from the beginning to the end of the output, which is preset by the ROM etc., and is added and synthesized. Waveform information may be generated.

Furthermore, in the above-described embodiment, the waveform information expressing the entire period from the beginning to the end of the waveform is calculated in advance, and a completely different envelope is manually input for this to calculate the waveform information having another envelope. However, for example, the envelope specified by manual input is added to the waveform information that represents the waveform of the entire period from the beginning to the end of the waveform that is stored in advance in the ROM, and a separate envelope is added. It is also possible to generate the waveform information that it has.

Further, in the above embodiment, the waveform is expressed in PCM, but as a method of digitally expressing the waveform, DPCM (Differential Pulse Code Modulatio
n), DM (Delta Modulation), ADM (Adaptive Delta M
It goes without saying that various types such as odulation) can be adopted.

〔The invention's effect〕

As described above, in the present invention, the waveform information representing the waveform of the predetermined period is input, and the envelope information for this waveform is also input, and the waveform from the beginning to the end of the waveform is represented from this information. Generating waveform information to be stored in the storage means, and digitally multiply the newly input envelope information and the already stored all waveform information to generate a new waveform of all the timbres, and store the waveform again. The waveform information is controlled so that all waveforms can be stored in the entire storage area without excess or deficiency when storing, so waveform information can be easily combined and output, and waveforms of various shapes can be input. It is effective because it can.

[Brief description of drawings]

The drawings show an embodiment of the present invention, FIG. 1 is a circuit configuration diagram of the first embodiment, FIG. 2 is a diagram for explaining the operation of the first embodiment, and FIG. 3 is a second embodiment. FIG. 4 is an external perspective view of the third embodiment, and FIG. 5 is a circuit construction diagram of the third embodiment. 1 ... input device, 2,3,6 ... memory, 4 ... waveform synthesis section, 5 ... adder, 7,8 ... switch, 12,13,16 ... memory, 14 ... multiplier, 15 …… Adder, 17,18 …… Gate, 19,20,25 …… Address counter, 21,22,26 …… Programmable divider,
30 …… Personal computer, 33 …… Digitizer, 40 …… Electronic keyboard instrument.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshi Morokuma 3-2-1 Sakaemachi, Hamura-cho, Nishitama-gun, Tokyo Satoshi Watanabe Examiner, Hamura Technology Center, Casio Computer Co., Ltd.

Claims (3)

[Claims] 1. A waveform information input means for inputting waveform information expressing a waveform of a predetermined period, an envelope information input means for inputting envelope information for determining an envelope for the waveform, and an envelope information input means for inputting the envelope information. Envelope information storage means for storing envelope information, digital multiplication of the waveform information input by the waveform input means and the envelope information stored in the envelope information storage means, and a new waveform from the beginning to the end. Multiplying means for generating first full-waveform information representing a waveform, full-waveform information storage means for storing the first full-waveform information generated by the multiplying means in a predetermined storage area, and the envelope information storage Means for storing the memory length of the means and all the waveform information in the all-waveform information storage means. According to the memory length of the area, the first total waveform information is generated from the multiplying means so that the start address and the end address of the storage area correspond to the start and end of the waveform respectively. The first control operation to be stored in the waveform information storage means is executed, the envelope information newly input by the envelope information input means and stored in the envelope information storage means, and the all-waveform information storage means The first all-waveform information is digitally multiplied again by the multiplication means, and according to the memory length of the envelope information storage means and the memory length of the storage area in the all-waveform information storage means for storing all the waveform information. , From the beginning of the waveform to the end of the waveform so that the start address and end address of this storage area correspond to the beginning and end of the waveform respectively. Control for executing a second control operation of causing the multiplication means to generate the second full-waveform information expressing the full-waveform of the above, and storing again the second full-waveform information generated by the multiplication means in the storage means. A waveform synthesizing device comprising: 2. The waveform synthesizing apparatus according to claim 1, wherein the waveform information input means is adapted to input the waveform information of the predetermined cycle by a handwriting input operation. 3. The waveform synthesizing apparatus according to claim 1, wherein the envelope information input means inputs the envelope information by a handwriting input operation.