JPS6278599A - Musical tone signal generator - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a musical tone signal generating device that can temporally change the timbre by sequentially switching and generating a plurality of different musical waveforms. This relates to making it possible to perform smooth switching.

[Conventional technology]

Japanese Patent Laid-Open No. 56-35192 discloses that a plurality of different tone waveforms stored in a waveform memory are sequentially switched and read out to generate a musical tone signal whose timbre changes over time.

JP-A No. 58-95790 discloses a method in which a plurality of different musical sound waveforms are read out by switching between /[ and two different musical sound waveforms that should occur before and after the other in time, as described above. Two series of musical sound waveforms are generated in parallel, and both waveforms are interpolated and synthesized according to a temporally changing interpolation function, thereby making it possible to smoothly switch between the two waveforms.

[Problem that the invention seeks to solve]

In the former prior art method, the waveform of the musical tone signal abruptly changes from the preceding musical sound waveform to the next musical sound waveform at the time of waveform switching, resulting in a rapid timbre change, which is unnatural. In the latter conventional method, such unnaturalness at the time of waveform switching can be prevented, but musical waveforms must be generated in two series, an interpolation function generation circuit is required, and There is a problem in that the hardware configuration becomes complicated due to the need for an interpolation calculation circuit such as a multiplier, resulting in high costs.

This invention has been made in view of the above-mentioned points, and aims to eliminate the unnaturalness when musical sound waveforms are changed, and to achieve this without requiring a complicated circuit configuration as seen in the interpolation method. It is an object of the present invention to provide a musical tone signal generating device that has the following characteristics.

[Means for solving problems]

The musical tone signal generating device of the present invention provides data on a plurality of main waveforms to be switched and read out in a predetermined order, and data on the two main waveforms to connect between the two main waveforms whose switching order is one after the other. a waveform storage means storing data of a bridging waveform consisting of a corresponding multi-period force); The apparatus further comprises a reading means for repeatedly reading data of the main waveform a predetermined number of times, reading data of the connecting waveform, and then repeatedly reading data of the following main waveform a predetermined number of times. be.

[Action and effect of the invention]

Temporal changes in timbre are obtained by switching and reading the data of multiple main waveforms in a predetermined order, but switching between two main waveforms that should be read out one after the other is caused by switching from the preceding main waveform. Instead of immediately switching to the subsequent main waveform, a transition waveform is interposed in between. Thereby, the obtained musical tone signal does not change abruptly from the preceding main waveform to the following main waveform, but changes smoothly with the intervening waveform interposed.

Therefore, according to the present invention, when obtaining a musical tone signal whose timbre changes over time by sequentially switching a plurality of waveforms, it is possible to smoothly switch waveforms by interposing a transition waveform at the time of switching. This will help eliminate the unnaturalness. Further, since the connecting waveforms are stored in advance in the storage means, there is no need for troublesome processing such as interpolating two series of waveforms, and the circuit configuration can be simplified and costs can be reduced.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

First, an example of a process for preparing main waveform data and connecting waveform data will be described with reference to FIG.

Sample the entire waveform of the desired natural instrument sound from the start to the end, and prepare this as the original waveform (see Figure 1).
a]).

Next, data for a plurality of main waveforms is created based on the original waveform. For example, since the waveform of the attack part changes rapidly, the entire waveform of the attack part, which consists of multiple periods in the original waveform, can be
The two main waveforms (this is referred to as attack waveform AT) are extracted. The original waveform after the attack part is divided into multiple frames along the time axis, and each frame consists of one cycle or multiple cycles of the main waveform (this is called the frame waveform F).
(hereinafter referred to as W1 to FW3) are created respectively. The frame waveforms FWj to FW3 can be created by, for example, extracting a typical one-cycle or multiple-cycle waveform in the frame from the original waveform, or calculating the average waveform of each one-cycle waveform in the frame, etc. Created by processing. An example of the plurality of main waveforms obtained in this way is shown in FIG. 1(b). It is assumed that the peak levels of all frame waveforms FW1 to FW3 are unified to a predetermined standard level. Note that the number of frames is not limited to three, but is arbitrary.

Next, connecting waveforms cw1 to cw3 between each main waveform are created. Each of the connecting waveforms cw1 to cw3 is for smoothly connecting two main waveforms whose switching order is one after the other, and consists of a plurality of cycles.

It is preferable to create a corresponding connecting waveform by performing a cross-fade interpolation calculation between two main waveforms whose switching order is one after the other. The connecting waveform cw1 corresponding to the attack part waveform AT and the first frame waveform FWj is created by repeating the last one-cycle waveform of the attack part waveform AT for multiple cycles and adding a cross-fade envelope with a falling characteristic to this waveform. On the other hand, the frame waveform FWj is created by repeating the same cycle to add a cross-fade envelope having a rising characteristic, and then adding the two. As a result, the attack waveform AT
Frame waveform Fw1 from the waveform corresponding to the last one cycle of
A multi-period waveform whose waveform changes smoothly up to the waveform corresponding to can be obtained as the first connecting waveform cw1.

Similarly, the first frame waveform FWj is repeated for a plurality of cycles to create a cross-fade envelope shape with a falling characteristic, and on the other hand, the second frame waveform F'
W2 is repeated for multiple cycles to create a cross-fade envelope with rising characteristics, and by adding the two, a second connecting waveform c consisting of multiple cycles is created.
Create w2. Thereafter, in the same way, two frame waveforms whose switching order is sequential are repeated for multiple cycles, and the multiple cycle waveform corresponding to the preceding frame waveform is weighted with the envelope of the falling characteristic to correspond to the following frame waveform. By weighting the multi-period waveform with the envelope of the rising characteristic and adding the two, a multi-period waveform whose waveform changes smoothly from the preceding frame waveform to the following frame waveform is created, and this is added to the two frame waveforms. The corresponding connecting waveform is used. In this way, the two main waveforms AT, FWj, FW2 whose switching order is sequential
, FW3, . . . , connecting waveforms cw1, cw2, cw3, . Figure 1 CC) shows these connecting waveforms c
An example of w1 to CW3 is schematically shown.

Main waveforms AT, FWI to FW3 prepared as above
The data at each sample point of the connecting waveforms cw1 to cw3 are encoded using a predetermined encoding method, such as PCM (pulse code modulation).
code and store it in the waveform memory. Figure 1(d)
is a schematic representation of the storage format of each main waveform and connecting waveforms in the waveform memory, and they are stored in the waveform memory according to the order in which they should be read.

A musical tone signal is generated by reading data of the main waveform and transition waveform from the waveform memory in a predetermined order. In that case, the number of repetitions of each waveform is determined in advance, and after reading out the waveform repeatedly for that number of times, the waveform is switched to the other waveform. FIG. 1(e) shows an example of the reading order of the main waveform and the transition waveform and the number of times the reading is repeated.

Next, an embodiment of the musical tone signal generating device of the present invention will be described with reference to FIG.

In the waveform memory 10, the main waveforms AT, FW1 to F'W3 and connecting waveforms cw1 to cw prepared in advance as described above are stored.
The data of w3 is stored for each selectable timbre type by the timbre selection circuit 11, respectively. The keyboard 12 includes a plurality of keys for specifying the pitch of musical tones to be generated. The pressed key detection circuit 13 detects the pressed keys on this keyboard 12,
Key code KC corresponding to the pressed key and signal “1” while the key is pressed
It outputs a key-on signal KON that maintains the key-on signal KON and a key-on pulse KONP that temporarily becomes a signal "1" at the start of key depression. The note clock generation circuit 14 generates a note clock pulse NC corresponding to the pitch of the pressed key according to the key code KC.
Generate P. The address counter 15 counts note clock pulses NCP and generates an address signal AD for reading out the waveform memory 10. This address counter 15 is reset by the key-on pulse KONP applied via the OR circuit 16 and the output signal of the comparator 17.

The start address memory 18 stores each main waveform AT, FW1 to F'W3 and connecting waveform C in the waveform memory 10.
The address (start address) at which the data of the first sample point of W[~CW3 is stored is stored for each tone color. The end address memory 19 stores each main waveform AT, FW1 to FW3 and connecting waveform cw1 in the waveform memory 10.
The address (end address) storing the data of the last sample point of ~cw3 is stored for each tone. 1st
Figure (d) shows start addresses 5o-S and end addresses E of each waveform AT-FW3. -E6 is illustrated. Note that in this embodiment, the start address 5o-8
6 is given as an absolute address in the waveform memory 10,
It is assumed that the end addresses Eo-E6 are given as relative addresses (that is, the number of addresses from the corresponding start addresses 5o-86). The repetition number memory 20 stores each main waveform AT, FW1 to FW3, and connecting waveforms cw1 to C.
The number of times W3 should be repeated and read out is stored for each tone, and an example of this is shown in Figure 1 (eJ).In other words, the attack waveform AT and transition waveforms cw1 to cw3, each consisting of multiple periods, are Read only once, frame waveforms Ftj and FW2 are repeated 8 times and M times, respectively (N and M are arbitrary integers), and the last frame waveform FW3 is repeated until the end of sound generation without setting a specific number of repetitions. .

Each of the main waveforms AT, F'W1 to FW3... and connecting waveforms CW1 to CW3... is collectively referred to as a segment, and the reading order is AT, CWl, FWl.
, CW2, FW2, CW3, FW3, . . . and segment numbers 0.1, 2, 3, 4, 5.6, . . . are assigned. The segment counter 21 is
The waveform to be read from the waveform memory 10 is specified by a segment number.When sound generation starts, the segment number is reset to O by the key-on pulse KONP.
That is, the attack portion waveform AT is specified and thereafter counted up by the output signal "1" of the comparator 23 provided via the AND circuit 22. The count value of this segment counter 21 is given to each memory 18, 19.20 as segment number data 5EGN. Each memo IJ
18 , 19 , and 20 are also given tone color selection information TC from the tone color selection circuit 11, and select the segment (main waveform AT, main waveform AT, FW
[~FW3... or connecting waveform CW1~cw3...
) start address (5o=Sa...
・) and end address (Eo=Ea...
. ) and the repetition count data, respectively.

The final segment memory 24 stores, for each timbre, the segment number of the main waveform (that is, frame waveform) that should be read out last in one sounding period from the start to the end of sounding. Read the data of the segment number. In FIG. 1, the final segment is the third frame waveform FW3, but this is just an example and can be arbitrary depending on the tone.

The comparator 17 compares the address signal AD output from the address counter 15 and the end address memory read from the end address memory 19, and outputs a signal "1" when the two match.

Therefore, every time the address signal AD for reading out the waveform memory 10 reaches the end address, a segment (main waveform AT, FW1 to FW3 or connecting waveform cw
1 to CW3) are read once, the comparator 17 outputs a signal "1"'. As mentioned above, the output of the comparator 17 is applied to the recent input of the address counter 15 via the OR circuit 16, and the counter 15 is reset each time the output signal of the comparator 17 becomes "1". be done.

The repetition counter 25 receives the output signal "1" from the comparator 17.
By counting the number of times the same segment is read repeatedly, the γ circuit 26
It is reset by the key-on pulse KONF applied via the comparator 23 and the output of the comparator 23. The comparator 23 outputs the output of the repetition counter 25 and the repetition number memo IJ 20.
When the two match, a signal "1" is output.

For example, when the repetition number data read from the repetition number memory 20 is "1", when the count value of the repetition number counter 25 reaches "1", the output of the comparator 26 is l.
'', thereby resetting the counter 25. Also, when the repetition number data read from the repetition number memory 20 is rNJ, the counter 25 is compared until the count value of the counter 25 becomes "N". The output of the comparator 17 is counted, and when it reaches rNJ, the comparator 23
The output becomes I I+ and the counter 25 is reset.

In this way, the segment (main waveform AT, FW1 to FW3
When the connecting waveforms cw1 to cw5) are read out a predetermined number of times, the output signal of the comparator 23 becomes 11'', and the signal ``1'' is applied via the AND circuit 22 to amplify the segment counter 21 for one count. As a result, the next ranked segment (main waveforms FW1 to F'W3 or connecting waveforms CW1 to CW3) is displayed on the segment counter 21.
The waveform to be read from the waveform memory 10 is switched. The comparator 27 compares the output 5EGN of the segment counter 21 and the output of the final segment memory 24, and when the two match, that is, when the final segment (for example, FW 3) is about to be read, the signal "1" is output. ′ is output. The output of this comparator 27 is inverted by an inverter 28, and the AND circuit 2
It joins the other inputs of 2. Therefore, the output signal of the inverter 28 applied to the AND circuit 22 is normally ? + ], n
This allows the output signal "1" of the comparator 23 to be given to the segment counter 21, but when the final segment is being read, it becomes "OI+", disabling the AND circuit 22, and causing the segment counter 21 to receive the output signal "1". Stop the counting operation of 21.

As a result, the output 5EGN of the segment counter 21 maintains the number of the last segment. Therefore, the number of repetitions of the waveform of the final segment is not limited, and it is possible to read out the waveform repeatedly until the end of sound generation.

The adder 29 adds the start address data read from the start address memory 18 and the address signal AD read from the address counter 15, and generates an address that specifies the waveform sample point data to be read from the waveform memory 10 using an absolute address. Data AAD is output and inputted into the waveform memory 10.

With the above configuration, the connecting waveform cw is created between the main waveforms AT, FWj to FW3, which are to be sequentially switched and read out.
1 to CW3... in the order in which the waveform memory 10 is interposed.
The data of each waveform is sequentially read out from the memory 20, and each waveform is repeatedly read out the number of times set in the repetition number memory 20.

That is, first, the key-on pulse KONP is activated at the start of key depression.
is generated, each counter 15, 2f.

25 is reset, and the segment number 5EGN output from the segment counter 21 becomes "0", specifying the attack waveform AT. As a result, data indicating the start address SO of the attack portion waveform AT is read from the start address memory 18. Further, if the number of repeated readings is set as shown in FIG. 1(e), data indicating the number of repetitions "1" is read from the memory 20. Also, from the end address memory 19, the end address E of the attack waveform AT. The indicated data is read out. The value of the address signal AD generated from the address counter 15 is sequentially increased by rOJ according to the note clock pulse NCP, and this is added to the start address S by the adder 29. address data AAD that increases sequentially from the start address data) is obtained. According to this address data AAD, the waveform memory 1
The data of the attack waveform AT is sequentially read out from 0. When the address signal AD matches the end address Eo, the output of the comparator 17 becomes the signal ff 1 +1, and the repetition counter 25 is incremented by one to make its content "1", and the address counter 15 is reset. Then, the repetition number data "1" read from the memory 2o and the count value "l" of the counter 25 match, the output of the comparator 23 becomes a signal "1", and the repetition number counter 25 is reset and the segment counter 2
Increment 1 by 1 and set the content to rlJ.

Segment number 5 outputted from the counter 21 in this way
EGN switches from "0" to "1", the attack waveform AT consisting of a plurality of periods is read out only once, and the first connecting waveform cw1 is designated as the waveform to be read out next. Thereafter, waveform readout and switching control are performed in the same manner, and in the case of FIG. 1(e), the attack part waveform AT
After reading out once, the first connecting waveform cw1 is read out once, then the frame waveform FWj of tube 1 is read out N times, the second connecting waveform cw2 is read out once, and then the frame waveform FW2 is read out repeatedly M times, then the third connecting waveform is read out once, and finally, frame waveform FW3 is read out repeatedly until at least the end of sound generation. As is clear from the above, the block including the circuits 14 to 29 functions as the reading means 60 of the waveform memory 10.

The waveform data read from the waveform memory 10 is sent to the multiplier 3.
1 and is multiplied by the envelope waveform signal provided from the envelope generator 32. The envelope generator 32 generates an envelope waveform signal having characteristics such as attack and decay based on the key-on signal KON and the tone selection information TC. If the attack part waveform AT stored in the waveform memory 10 has been given an attack envelope in advance, the rise of the envelope waveform signal generated from the envelope generator 32 will not show any particular attack curve characteristics and will rise suddenly. However, if the peak level of the attack waveform AT is normalized to a constant level and is stored in the waveform memory 10, this envelope waveform signal rises with a predetermined attack curve characteristic. The output of the multiplier 31 is converted into an analog signal by a digital/analog converter 33 and provided to a sound system 34.

In the above embodiment, the end address data stored in the end address memory 19 is expressed as a relative address, but it may be expressed as an absolute address. In that case, absolute address data AAD is input to comparator 17 instead of relative address signal AD.

In the above embodiment, the attack section waveform AT consisting of multiple cycles is read out only once.
The present invention is not limited to this, and a predetermined one-cycle waveform may be repeatedly read out a predetermined number of times.

Also, a reading means 30 for reading out the waveform memory 10.
This is not limited to a discrete circuit as shown in FIG. 2, but may be implemented by a software program using a microcomputer.

In the above embodiment, the connecting waveforms cw1 to cw3... are prepared by performing cross-fade interpolation calculations on two main waveforms that follow each other, but the present invention is not limited to this.
The connecting waveforms may be formed in any way as long as the two main waveforms can be smoothly connected. For example, extract a suitable multi-period waveform from the original waveform,
A connecting waveform may be created by modifying this as appropriate.

In the above embodiment, the main waveforms, that is, the frame waveforms FWj to F'W3, which should be repeatedly read out, can each be set to any period, and are not limited to waveforms with one period, but can be waveforms with two or more periods. may be a waveform of less than one cycle, such as 〒cycle.

When a waveform of less than one period is stored, it is read out as a one-period waveform by a technique such as phase inversion or reverse reading, as is generally known, and this process is repeated.

The original waveform that is the basis for creating the main waveform and the connecting waveform is not limited to a sampled natural instrument sound, but may be any other waveform, such as a waveform of a sound artificially created by a synthesizer or the like. Furthermore, each main waveform may be created as appropriate without preparing the original waveform.

The main waveform and the connecting waveform are stored in the waveform memory separately for each key (each pitch) or for each predetermined key range (range), and the They may also be selected and read out.

In addition, the encoding method of waveform data stored in the waveform memory is not limited to the PCM method, but also the differential PCM method, delta modulation (D
Any method may be used, such as M) method or adaptive delta modulation (ADM) method. In that case, an appropriate decoding circuit shall be provided on the output side of the waveform memory.

Although FIG. 2 shows a single-tone electronic musical instrument, the present invention can also be applied to a multi-tone electronic musical instrument. In that case, each counter 15, 21, 25 may be configured to operate in a time-divisional manner on a plurality of channels. Furthermore, the present invention is not limited to the generation of scale tones corresponding to each key, but can be applied to the generation of rhythm tones and other audible tones.

[Brief explanation of drawings]

FIG. 1 is a diagram schematically showing an example of a main waveform and a connecting waveform to be stored in a waveform memory, and FIG. 2 is a block diagram of an electronic musical instrument according to an embodiment of the present invention. AT...Attack waveform, FW1~FW3...Frame waveform, cw1~cw3...Connection waveform, So~S6...
...Start address, Eo-E6...End address, 10...Waveform memory, 11...Tone selection circuit,
12...Keyboard, 60...Reading means.

Claims (1)

[Scope of Claims] For connecting data of a plurality of main waveforms to be switched and read in a predetermined order and two main waveforms whose switching order is consecutive, corresponding to the two main waveforms, a waveform storage means storing data of a connecting waveform consisting of a plurality of periods; and data of the preceding main waveform in an order in which the corresponding connecting waveform is interposed between the two main waveforms to be read out one after the other. 1. A musical tone signal generating device comprising: reading means for repeatedly reading data of the connecting waveform a predetermined number of times, then reading data of the following main waveform repeatedly a predetermined number of times.