JPH0727384B2 - Music signal generator - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a musical tone signal generator capable of temporally changing a tone color by sequentially generating a plurality of different musical tone waveforms, and more particularly to a waveform. The present invention relates to enabling smooth switching of.

[Conventional technology]

Japanese Patent Application 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 tone signal whose tone color changes with time.

Japanese Patent Laid-Open No. 58-95790 discloses that a plurality of different musical tone waveforms are sequentially switched and read out in the same manner as described above, in which two musical tones to be generated before and after in time are generated. Waveforms are generated in parallel in two sequences, and both waveforms are interpolated and synthesized according to an interpolating function that changes with time, so that the switching of both waveforms can be performed smoothly.

[Problems to be solved by the invention]

In the former method such as the conventional technique, the waveform of the musical tone signal changes abruptly from the preceding musical tone waveform to the next musical tone waveform at the time of waveform switching, resulting in an abrupt tone color change, which is unnatural. In the latter method of the prior art, such unnaturalness at the time of switching waveforms can be prevented, but a musical tone waveform must be generated in two sequences, and an interpolation function generating circuit is required, and There is a problem that the hardware configuration becomes complicated and the cost becomes high because an interpolation calculation circuit such as a multiplier is required.

The present invention has been made in view of the above points, and it is possible to eliminate the unnaturalness at the time of switching musical tone waveforms and to realize it without requiring a complicated circuit configuration as seen in the interpolation method. The present invention intends to provide a musical tone signal generator according to the above.

[Means for solving problems]

The tone signal generator of the present invention has a plurality of main waveform data which are waveforms corresponding to a part of one tone and are to be read out by switching in a predetermined order, and two main waveforms whose switching orders are adjacent to each other. Waveform storage means for connecting between the waveforms, which stores data of a connecting waveform consisting of a plurality of periods, corresponding to the two main waveforms, and a repeat for storing the number of times of repeated reading for each of the plurality of main waveforms. The data of the preceding main waveform is stored in the repetition number storage means in the order of interposing the connecting waveform corresponding to the number of times storage means and the two main waveforms to be read one after another. After repeatedly reading the number of times indicated by the number of repetitions of the main waveform, the data of the connecting waveform is read, and then the data of the subsequent main waveform is repeated the number of times of repetition. It is characterized in that comprises a waveform reading means for repeatedly count about the main waveform stored in 憶 means repeatedly read out as many times shown.

[Operation and effect of the invention]

The time change of the timbre can be obtained by switching and reading the data of a plurality of main waveforms in a predetermined order. However, the switching of two main waveforms that should be read one after the other is different from the preceding main waveform. Instead of immediately switching to the subsequent main waveform, a connecting waveform is interposed between them. As a result, the obtained tone signal changes smoothly from the preceding main waveform to the succeeding main waveform without interposing a connecting waveform.

Therefore, according to the present invention, when a musical tone signal whose tone color changes with time is obtained by sequentially switching a plurality of waveforms, smooth waveform switching can be performed by interposing a connecting waveform at the time of switching. It will be possible to eliminate unnaturalness. Further, since the connecting waveform is stored in the storage means in advance, a troublesome process such as interpolation of two series of waveforms is not necessary, and the circuit configuration can be simplified and the cost can be reduced.

Further, it is possible to change the tone color time variation mode only by changing the number of repetitions of each main waveform stored in the number of repetitions storage means, and to generate musical tones having various variation modes with a relatively simple structure. be able to.

〔Example〕

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

First, with reference to FIG. 1, an example of the process of preparing the main waveform data and the connected waveform data will be described.

All waveforms from the start to the end of the desired natural musical instrument sound are sampled and prepared as an original waveform (Fig. 1 (a)).

Next, data of a plurality of main waveforms is created based on the original waveform. For example, since the attack part has a drastic change in waveform, the entire waveform of the attack part consisting of a plurality of periods in the original waveform is taken out as one main waveform (this is called attack part waveform AT). The original waveform after the attack part is divided into a plurality of frames along the time axis, and a main waveform consisting of one cycle or a plurality of cycles for each frame (this is the frame waveform FW
1 to FW3) data is created respectively. The frame waveforms FW1 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 an average waveform of each one-cycle waveform in the frame. Created by the process. An example of the plurality of main waveforms thus obtained is shown in FIG. 1 (b). The peak levels of all the frame waveforms FW1 to FW3 are unified to a predetermined standard level. The number of frames is not limited to 3,
It is optional.

Next, connecting waveforms CW1 to CW3 between each main waveform are created.
Each of the connecting waveforms CW1 to CW3 is for smoothly connecting between two main waveforms whose switching orders are consecutive and has a plurality of cycles. It is advisable to create a corresponding connecting waveform by performing a crossfade interpolation calculation between two main waveforms whose switching orders are adjacent to each other. Attack part waveform AT
And the connecting waveform CW1 corresponding to the first frame waveform FW1 is
The last one cycle waveform of the attack part waveform AT is repeated a plurality of cycles to create a crossfading envelope with a falling characteristic, and on the other hand, the frame waveform FW1 is repeated for the same cycle to create a rising characteristic. It is created by adding a crossfade envelope and adding both. As a result, the attack waveform AT
It is possible to obtain, as the first connecting waveform CW1, a multi-cycle waveform in which the waveform smoothly changes from the waveform corresponding to the last one cycle of the waveform to the waveform corresponding to the frame waveform FW1. Similarly, the first frame waveform FW1 is repeated for a plurality of cycles to create a crossfade envelope having a falling characteristic, and on the other hand, the second frame waveform FW2 is repeated for a plurality of cycles to obtain a rising characteristic. Is added with the crossfade envelope and the both are added to create the second connecting waveform CW2 having a plurality of cycles. In the same manner, two frame waveforms whose switching order is repeated are repeated for a plurality of cycles, and a plurality of cycle waveforms corresponding to the preceding frame waveform are weighted by the falling characteristic envelope to correspond to subsequent frame waveforms. The multiple cycle waveforms are weighted with the envelope of the rising characteristic, and by adding them, a multiple cycle waveform whose waveform changes smoothly from the preceding frame waveform to the following frame waveform is created, and this is converted into the two frame waveforms. Use the corresponding connecting waveform. In this way, connecting waveforms CW1, CW2, CW3, ... Composed of a plurality of cycles are created in advance corresponding to the combination of the two main waveforms AT, FW1, FW2, FW3 ... Fig. 1 (c) shows these connecting waveforms CW.
1 schematically shows an example of 1 to CW3.

The data of the sample points of the main waveforms AT, FW1 to FW3 and the connecting waveforms CW1 to CW3 prepared as described above are encoded by a predetermined encoding method, for example, PCM (pulse code modulation) method, and stored in the waveform memory. FIG. 1 (d) schematically shows the storage format of each main waveform and the connecting waveform in the waveform memory, and the waveforms are stored in the waveform memory in the order of reading.

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

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

In the waveform memory 10, the data of the main waveforms AT, FW1 to FW3 and the connecting waveforms CW1 to CW3 prepared in advance as described above are stored for each tone color type selectable by the tone color selection circuit 11. The keyboard 12 is provided with a plurality of keys for designating the pitch of the musical sound to be generated. In the key press detection circuit 13, this keyboard 12
Detected the pressed key in, and the key code corresponding to the pressed key
Key-on signal KON that keeps signal "1" during KC and key-pressing and key-on pulse KO that temporarily becomes signal "1" when key-pressing starts
Output NP. The note clock generation circuit 14 generates a note clock pulse NCP corresponding to the pitch of the pressed key according to the key code KC. The address counter 15 counts the note clock pulse NCP and generates an address signal AD for reading the waveform memory 10. The address counter 15 is reset by the key-on pulse KONP given through the OR circuit 16 and the output signal of the comparator 17.

The start address memory 18 stores, for each tone color, an address (start address) storing the data of the first sample points of the main waveforms AT, FW1 to FW3 and the connecting waveforms CW1 to CW3 in the waveform memory 10. End address memory
Reference numeral 19 stores, for each tone color, an address (end address) storing the data of the last sample points of the main waveforms AT, FW1 to FW3 and the connecting waveforms CW1 to CW3 in the waveform memory 10. The first diagram (d), the start address S ₀ to S ₆ and the end address E ₀ to E ₆ of each waveform AT~FW3 is illustrated. In this embodiment, the start addresses S _{0 to} S ₆ are given as absolute addresses in the waveform memory 10, and the end addresses E _{0 to} E ₆ are relative addresses (that is, from the start addresses S _{0 to} S ₆ corresponding to the respective addresses). Address number). Repeat count memory 20 is used for each main waveform AT, FW1 to FW
3 and the connecting waveforms CW1 to CW3 are repeatedly stored and stored for each timbre, one example of which is shown in FIG. 1 (e). That is, the attack waveform AT and the connecting waveforms CW1 to CW3 each having a plurality of cycles are read out only once, and the frame waveforms FW1 and FW2 are repeated N times and M times (N and M are arbitrary integers) and the last frame. Waveform FW
For step 3, do not set the number of repetitions and repeat until the end of sound generation.

Main waveform AT, FW1 to FW3 ... and connecting waveforms CW1 to CW3 ...
・ Each of these is collectively referred to as a segment, and according to the reading order AT, CW1, FW1, CW2, FW2, CW3, FW3 ...
It is assumed that the segment numbers 0, 1, 2, 3, 4, 5, 6 ... Are assigned. The segment counter 21 designates the waveform to be read from the waveform memory 10 by the segment number, and is reset to 0 by the key-on pulse KONP at the start of sound generation and is segment number 0, that is, the attack waveform AT.
Is designated, and thereafter, it is counted up by the output signal "1" of the comparator 23 given through the AND circuit 22. The count value of the segment counter 21 is given to each memory 18, 19, 20 as segment number data SEGN. Each memory 18, 19, 20 is also provided with tone color selection information TC from the tone color selection circuit 11, and according to the selected tone color and segment number data SEGN, the segment (main waveform AT, FW1 to FW3 ... or connecting waveform C
Any one of W1 to CW3 ...) Start address (S
₀ ~ S ₆ ... any one) and end address (E ₀ ~ E
₆ ) and the repeat count data are read out.

The last segment memory 24 is from the start to the end 1
The segment number of the main waveform (that is, the frame waveform) to be read out last in the sounding period is stored for each tone color, and the data of the segment number is read out according to the tone color selection information TC. In FIG. 1, the final segment is the third frame waveform FW3, but this is only an example and is arbitrary depending on the timbre.

The comparator 17 compares the address signal AD output from the address counter 15 with the end address data read from the end address memory 19, and outputs a signal "1" when both match. Therefore, each time the address signal AD for reading the waveform memory 10 reaches the end address, that is, the segment (main waveform AT, FW1 to FW3 or the connecting waveform CW1
~ CW3) is read once, the comparator 17 outputs the signal "1".
Is output. As described above, the reset input of the address counter 15 is given the output of the comparator 17 via the OR circuit 16, and the counter 15 is reset every time the output signal of the comparator 17 becomes “1”. It

The repetition number counter 25 counts the number of times the same segment is repeatedly read by counting the output signal “1” of the comparator 17, and outputs the key-on pulse KONP given through the OR circuit 26 and the comparator 23. Reset by. The comparator 23 compares the output of the repeat count counter 25 with the output of the repeat count memory 20, and outputs a signal "1" when the two match. For example, when the repeat count data read from the repeat count memory 20 is "1", when the count value of the repeat count counter 25 becomes "1", the output of the comparator 23 becomes "1". Counter 25 is reset. When the repeat count data read from the repeat count memory 20 is "N", the counter 25 is counted until the count value of the counter 25 becomes "N".
Then, the output of the comparator 17 is counted, and when it becomes "N", the output of the comparator 23 becomes "1" and the counter 25 is reset.

In this way, when the segment (main waveform AT, FW1 to FW3 or connecting waveforms CW1 to CW3) is read a predetermined number of times, the comparator 23
Output signal becomes "1", the signal "1" is given through the AND circuit 22, and the segment counter 21 is incremented by one. This allows the next highest segment (main waveform
FW1 to FW3 or connecting waveforms CW1 to CW3) are designated by the output SEGN of the segment counter 21, and the waveform to be read from the waveform memory 10 is switched. The comparator 27 compares the output SEGN of the segment counter 21 with the output of the final segment memory 24, and outputs a signal "1" when they match, that is, when the final segment (eg FW3) is read out. To do. The output of this comparator 27 is the inverter 28.
It is inverted by and is added to the other input of the AND circuit 22. Therefore, the output signal of the inverter 28 applied to the AND circuit 22 is
Normally it is "1", which allows the output signal "1" of the comparator 23 to be given to the segment counter 21, but it becomes "0" when the last segment is being read, and the AND circuit 22 is disabled. Then, the segment counter 21 stops counting. This enables the segment counter 21
The output SEGN of keeps the number of the last segment. Therefore, the number of repetitions of the waveform of the final segment is not limited,
It is possible to read repeatedly until the end of sounding.

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 specifies the waveform sample point data to be read from the waveform memory 10 with an absolute address. Outputs data AAD and stores it in waveform memory 1
Enter 0.

With the above configuration, the connecting waveforms CW1 to CW3 ... between the main waveforms AT, FW1 to FW3 ...
The data of each waveform is sequentially read from the waveform memory 10 in the order of interposing, and the individual waveforms are repeatedly read the number of times set in the repeat count memory 20. That is, first, when a key-on pulse KONP is generated at the start of key depression, each counter 15, 21, 25 is reset, the segment number SEGN output from the segment counter 21 becomes "0", and the attack waveform AT is specified. To do. As a result, the data indicating the start address S ₀ of the attack portion waveform AT is read from the start address memory 18. If the number of times of repeated reading is set as shown in FIG. 1 (e), data indicating the number of times of repeated "1" is read from the memory 20. Also, the end address memory 19
From this, data indicating the end address E ₀ of the attack portion waveform AT is read. The value of the address signal AD generated from the address counter 15 sequentially increases from “0” according to the note clock pulse NCP, and this is added to the start address S ₀ by the adder 29, so that the start address S ₀
The address data AAD that sequentially increases from is obtained. Data of the attack portion waveform AT is sequentially read from the waveform memory 10 according to the address data AAD. Address signal AD
When the end address E ₀ coincides with the end address E ₀ , the output of the comparator 17 becomes the signal “1”, the repeat counter 25 is incremented by 1 to set its content to “1” and the address counter
Reset 15 Then, the repeat count data “1” read from the memory 20 and the count value “1” of the counter 25 match, the output of the comparator 23 becomes a signal “1”, the repeat count counter 25 is reset, and the segment counter is reset. Count up 21 and set the content to "1". In this way, the segment number output from the counter 21
SEGN switches from "0" to "1", the attack waveform AT consisting of a plurality of cycles is read out only once, and the first connecting waveform CW1 is designated as the waveform to be read next. Waveform reading and switching control are performed in the same procedure below. In the case of FIG. 1 (e), the attack waveform AT is read once, the first connecting waveform CW1 is read once, and then the 1 frame waveform FW1 is read N times, then the second connection waveform CW2 is read once, then frame waveform FW2 is read M times, then the third connection waveform is read once, and finally The frame waveform FW3 is repeatedly read at least until the end of sounding. As is clear from the above, a block including circuits 14 to 29 functions as the reading means 30 of the waveform memory 10.

The waveform data read from the waveform memory 10 is given to the multiplier 31, and is multiplied by the envelope waveform signal given from the envelope generator 32. 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 color selection information TC. Attack waveform AT stored in waveform memory 10
If the attack envelope is given in advance, the rising edge of the envelope waveform signal generated from the envelope generator 32 may be a sharp rise without showing any particular attack curve characteristic, but the attack portion When the peak level of the waveform AT is standardized to a constant level and stored in the waveform memory 10, the envelope waveform signal rises with a predetermined attack curve characteristic. The output of the multiplier 31 is converted into an analog signal by the digital / analog converter 33 and given to the 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, the absolute address data AAD is input to the comparator 17 instead of the relative address signal AD.

In the above-described embodiment, the attack part reads the attack part waveform AT consisting of a plurality of cycles only once, but the invention is not limited to this, and a predetermined one cycle waveform may be repeatedly read a predetermined number of times.

Further, the reading means 30 for reading the waveform memory 10 is
The present invention is not limited to the discrete type circuit as shown in FIG. 2, but may be implemented by a software program using a microcomputer.

In the above-described embodiment, the connecting waveforms CW1 to CW3 ... Are prepared by performing crossfade interpolation calculation of two main waveforms that follow each other. However, the present invention is not limited to this. The connecting waveform may be formed by any method as long as it can be smoothly connected. For example, an appropriate multi-period waveform may be extracted from the original waveform, and the connected waveform may be created by appropriately modifying the waveform.

In the above-described embodiment, the main waveforms to be repeatedly read, that is, the frame waveforms FW1 to FW3 ... Can be set to arbitrary periods, and are not limited to one period waveforms and two or more period waveforms. Or a waveform of less than 1 cycle such as 1/2 cycle or 1/4 cycle. When a waveform of less than one cycle is stored, as is generally known, it is read as a one-cycle waveform by a method such as phase inversion or reverse reading, and this is repeated.

The original waveform that is the basis for creating the main waveform and the connecting waveform is not limited to a sample of a natural musical instrument sound, and may be any other waveform such as a sound waveform artificially created by a synthesizer. Further, each main waveform may be appropriately created without preparing the original waveform.

The main waveform and connecting waveform are stored in the waveform memory separately for each key (each pitch) or for each predetermined key range (tone range), depending on the pitch (or range) of the musical tone to be generated. They may be selected and read out.

Also, the encoding method of the waveform data stored in the waveform memory is
Not limited to the PCM system, any system such as a differential PCM system, a delta modulation (DM) system, an adaptive delta modulation (ADM) system may be used. In that case, an appropriate decoding circuit is provided on the output side of the waveform memory.

Although a single-tone electronic musical instrument is shown in FIG. 2, the present invention can 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. Further, the present invention can be applied not only to the generation of the scale sound corresponding to each key, but also to the generation of rhythm sound and other audible sounds.

[Brief description 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 to FW3 …… Frame waveform, CW
1~CW3 ...... connecting waveform, S ₀ ~S ₆ ...... start address,
E _{0 to} E ₆ …… End address, 10 …… Waveform memory, 11 ……
Tone selection circuit, 12 ... keyboard, 30 ... reading means.

Claims (1)

[Claims] 1. Data of a plurality of main waveforms, which are waveforms corresponding to respective portions of one musical tone and are to be read out by switching in a predetermined order, and between two main waveforms whose switching orders are in tandem. Waveform storage means for storing data of a connecting waveform consisting of a plurality of cycles, which corresponds to the two main waveforms, and a repetition number storage means for storing the number of repeated readings for each of the plurality of main waveforms. Repeating the data of the preceding main waveform with respect to the main waveform stored in the repetition number storage means in the order of interposing the corresponding connecting waveform between the two main waveforms to be read one after another. After repeatedly reading the number of times indicated by the number of times, the data of the connecting waveform is read, and subsequently the data of the main waveform is stored in the number of repetitions storing means. And has musical tone signal generating apparatus comprising a waveform reading means for reading repeatedly as many times indicated by the number of repetitions concerning the main waveform.