JPH11167382A - Waveform forming device and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a waveform of good quality rich in controllability by performing an extension and contraction control of a loop reproducing time when forming a sound waveform by using a loop waveform, and to perform a time-axis extension and contraction control of musical sound components in synchronism with that of musical sound waveform. SOLUTION: A loop reproducing waveform is formed by repeating a predetermined loop waveform in a predetermined sounding period, and when a sound waveform is formed including a section of plural different loop reproducing waveforms, it is generated by varying a time control signal TV timewise for expansion and contraction control of a waveform reproducing time, and the time length of each loop reproducing waveform section is controlled to be extended and contracted according to the time control signal TV. Moreover, in the case of generating musical sound control signals AV, PV varying timewise and controlling a time process of a musical waveform to be formed according to the musical sound control signals AV, TV, the time control signal TV for controlling a time process is generated, and according to this control signal, the time process of the musical sound waveform is controlled to be extended and contracted, and also according to this time control signal, the time process of the musical sound control signal is controlled to be extended and contracted at the same time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and a method for forming a waveform of a musical sound, voice or any other sound based on reading of waveform data from a memory or the like. In a technique for forming a waveform by repeating a predetermined loop waveform in a section, the present invention relates to performing expansion / contraction control of a waveform reproduction time. The present invention is not limited to electronic musical instruments, but also includes automatic performance devices, computers, electronic game devices, and other multimedia devices.
The present invention can be widely applied to devices, apparatuses, or methods in all fields having a function of generating a musical sound, a voice, or any other sound. In this specification, the musical sound waveform is not limited to a musical sound waveform, but may be a sound or any other sound waveform.

[0002]

2. Description of the Related Art In a waveform memory, PCM (pulse code modulation), DPCM (differential PCM), or ADPC
M (adaptive difference PCM) or the like, waveform data (that is, waveform sample data) encoded by an arbitrary encoding method is stored, and read out in correspondence with a desired musical tone pitch to form a musical tone waveform. The so-called “waveform memory readout” technique is already known, and various types of “waveform memory readout” techniques are known. Most of the conventionally known "waveform memory reading" techniques are for generating a single sound waveform from the start to the end of sounding. As an example, there is a method of storing waveform data of the entire waveform of one sound from the start to the end of sounding.
As another example, there is a method of storing the waveform data of all the waveforms in an attack portion having a complicated change, and storing a predetermined loop waveform in a sustain portion having little change (for example, Japanese Patent Application Laid-Open No. S59-5959). No. 188697). In the latter method, the amount of waveform data storage can be simplified by storing loop waveforms, and
By repeatedly reading out the loop waveform, the duration of the sound can be arbitrarily adjusted. In this specification, the “loop waveform” is used to mean a waveform that is repeatedly read (loop read).
The “loop reproduction waveform” is used to mean a waveform obtained (reproduced) by repeatedly reading (loop reading) the “loop waveform”.

Further, in order to generate one sound, a plurality of loop waveforms are used, each loop waveform is sequentially switched and read according to a specific sequence, and loop read output data of preceding and succeeding loop waveforms (that is, "loop reproduction output data"). Waveform")
Is also known (for example, Japanese Patent Application Laid-Open No. Sho 62-14696) in which the loop reproduction waveforms are connected smoothly by cross-fading. In this case, the cross-fade synthesis is performed in a predetermined cross-fade section. Unlike the simple repetitive reading technique of one loop waveform described above, the time length of each cross-fade section is arbitrarily variable. There is no indication of adjusting. That is, the cross-fade section can be switched only in a preset switching time, and controllability is poor.

On the other hand, as a time axis compression technique of an audio signal, for example, there is a technique disclosed in Japanese Patent Application Laid-Open No. 1-93795. It shows that a speech waveform is divided into a vowel section and a consonant section, the time axis compression ratio of the consonant section is relatively reduced, and the time axis compression ratio of the vowel section is relatively increased. Japanese Patent Application Laid-Open No. 5-274599 discloses that time axis compression control is not performed in a consonant section, and time axis compression control is performed only in a vowel section. However, these techniques are for data compression of an audio signal, and have nothing to do with consideration of articulation (playing style) of sound or enabling control thereof.

[0005]

The conventional tone waveform forming technique using a loop waveform is suitable for simplifying the amount of waveform data to be stored. It is not suitable for the formation of sound, and the articulation of sound
Was not related to the formation of the musical sound waveform. In general, in the musical sound waveform forming technique using a loop waveform, only a loop of a predetermined time mode can be performed.
Poor control and poor editability. on the other hand,
In the conventional voice time axis compression control technology, it is not considered to apply such a time axis compression control technology to a musical sound generation technology. No measures have been considered.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and when a sound waveform is formed using a loop waveform, a high-quality waveform is formed in consideration of sound articulation (playing style). It is an object of the present invention to provide a waveform forming apparatus and a method which are rich in controllability and editability. In addition, a waveform forming apparatus and method capable of performing appropriate control in consideration of control for various tone elements (pitch, volume, tone, etc.) of a musical sound waveform when performing time axis expansion / contraction control of the musical sound waveform. It is something to offer.

[0007]

According to a first aspect of the present invention, there is provided a waveform forming apparatus for controlling expansion and contraction of a waveform reproduction time, and a time control signal for generating a time control signal which is temporally variable. A generating unit, generating a loop reproduction waveform by repeating a predetermined loop waveform in a predetermined section in a sound generation period, forming a waveform of the sound including a plurality of different loop reproduction waveform sections, and forming each loop. A waveform forming unit that controls expansion and contraction of the time length of the reproduction waveform section according to the current value of the time control signal.

According to the present invention, for a plurality of different loop playback waveform sections, the playback time length, that is, the sound corresponding to the loop playback waveform is changed according to the current value of the temporally variable time control signal. The existing time length is controlled to expand and contract.
Therefore, a unique change can be given to a plurality of loop reproduction waveform sections constituting a sound, and a waveform with high controllability can be formed. Since the controllability of the loop reproduction waveform is improved in this manner, a loop waveform having a relatively simple waveform structure (for example, having a small memory capacity) can be converted into a high-quality waveform in consideration of sound articulation (playing style). It has an excellent effect that it can be easily used even in the formation scene. Further, since the time length of each loop reproduction waveform section is controlled to be expanded or contracted at any time according to the current value of the time control signal, the time length of a certain section of a plurality of loop reproduction waveform sections constituting a sound is set. , And extend the duration of another section, and so on.
It is now possible to combine multiple loop playback waveform sections with various time variations, so that it is possible to form a highly controllable waveform for the tone of the loop part, which could only be controlled monotonously in the past. No, it has an excellent effect.

In one embodiment, the time control signal changes with time according to a predetermined function, and the function may use a current value of the time control signal as a time variable. Thus, the predetermined function for generating the time control signal itself is controlled in accordance with the current value of the time control signal, thereby controlling the time lapse of the generation. Therefore, with the expansion and contraction of the waveform reproduction time according to the time control signal, the time lapse of the time control signal itself can be appropriately controlled.

Further, as one embodiment, the waveform forming section generates a first loop reproduction waveform by repeating a predetermined first loop waveform in the predetermined section and repeats a second loop waveform. Then, a second loop reproduction waveform may be generated, and the first and second loop reproduction waveforms may be cross-fade synthesized in the predetermined section to form a synthesized loop reproduction waveform. According to this, smooth waveform connection is performed by cross-fade synthesis, and interconnection of a plurality of loop reproduction waveform sections can be performed smoothly. In addition, since the time length of the first and second loop reproduced waveforms to be cross-fade synthesized can be controlled to expand and contract in accordance with the time control signal, the articulation (playing style) of the sound is considered in the same manner as described above. A good quality waveform can be easily formed using a loop waveform.

In one embodiment, the waveform forming section may generate a loop reproduction waveform by repeatedly reading out the waveform data of the loop waveform from a memory storing the waveform data of the loop waveform. Of course,
The present invention is not limited to this. For example, an arithmetic circuit, a non-linear circuit, a function generation circuit, or the like may be used as a loop waveform generation source without using a memory or a table as a loop waveform generation source.

A waveform forming apparatus according to a second aspect of the present invention includes a first control signal generating section for generating a time-varying musical tone control signal and a second control signal generating section for generating a time control signal for controlling the passage of time. A control signal generator, for forming a musical tone waveform, wherein the time lapse of the musical tone waveform to be formed is controlled by a time control signal generated by the second control signal generator, and the time control signal A waveform control section for controlling the time lapse of the musical tone control signal generated by the first control signal generating section and controlling the characteristics of the musical tone waveform to be formed by the musical tone control signal whose time lapse is controlled.

According to this, the lapse of time of the musical tone waveform formed by the waveform forming section is controlled by the time control signal, and the waveform reproduction time can be controlled to expand and contract by the time control signal in the same manner as described above. The tone control signal generated by the first control signal generator may control an arbitrary tone element such as an amplitude, a pitch, and a tone. It is well known that such a time-varying musical tone control signal is, for example, an amplitude envelope, a pitch variation envelope, or a timbre variation envelope. When controlling the expansion and contraction of the waveform reproduction time by the time control signal, not only the musical sound waveform but also the musical sound control signal for controlling the waveform, that is, the time axis of the amplitude envelope and the pitch change envelope, are simultaneously expanded and contracted to obtain the musical sound waveform. And the tone control signal for controlling the waveform can be controlled in synchronization with the time axis. Therefore,
When performing time axis expansion / contraction control of a musical sound waveform, it is possible to perform appropriate control in consideration of control for various musical sound elements (pitch, volume, tone, etc.) of the musical sound waveform. In the waveform forming apparatus according to the second aspect, the musical tone waveform may be either a loop waveform or a non-loop waveform, or may include both.

The present invention can be constructed and implemented not only as an apparatus invention, but also as a method invention.
It can also be implemented. Further, the present invention can be implemented in the form of a computer program, and can also be implemented in the form of a recording medium storing such a computer program. Further, the present invention can be embodied in the form of a recording medium storing waveform data having a novel data structure.

[0015]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a block diagram showing a hardware configuration example of a waveform forming apparatus according to one embodiment of the present invention. The hardware configuration example shown here is configured using a computer, and the waveform forming process is performed by executing a predetermined program (software) that realizes the waveform forming process according to the present invention. Will be implemented. Of course, this waveform formation processing is not limited to the form of computer software, but can also be implemented in the form of a microprogram processed by a DSP (digital signal processor). The present invention may be embodied in the form of a dedicated hardware device including a discrete circuit or an integrated circuit or a large-scale integrated circuit. Further, the waveform forming device may take any product application form such as an electronic musical instrument, a karaoke device, an electronic game device, other multimedia devices, or a personal computer.

In the example of the hardware configuration shown in FIG. 1, a CPU (central processing unit) 100 as a main control unit of a computer is provided with a ROM (read only memory).
101, RAM (random access memory) 102, hard disk device 103, removable disk device (for example, CD-ROM drive or MO drive) 104, display device 105, input operation device 106 such as keyboard and mouse, waveform interface 107, timer 108 , A communication interface 109, a MIDI interface 110 and the like are connected via a bus 111. The waveform interface 107 has a function of inputting an analog waveform signal (audio signal) from the outside, converting the signal into a digital signal, and sending the digital signal to the bus 111. It has a function of receiving the data via an analog converter, converting the data into an analog signal, and outputting the converted signal to a speaker system or the like. Of course, it is also possible to transfer and output the formed digital waveform data as it is to the outside.

When the waveform forming apparatus is in the form of a product application of a musical instrument, the input operation device 106 includes a performance keyboard for selecting and specifying a desired musical tone pitch. On the other hand, when this waveform forming apparatus is in a product application form other than the musical instrument, the MID
A MIDI keyboard module is connected to the I interface 110 so that a desired tone pitch can be selected and designated. The selection and designation of a desired tone pitch may be given in the form of automatic performance data. Automatic performance data is stored in ROM 101, RAM 102,
The information may be provided by reading data stored in any of the storage devices such as the hard disk device 103 and the removable disk device 104, or may be provided externally via the MIDI interface 110. Good. Although not described in detail,
As is generally known in the field of electronic musical instruments, the input operation device 106 includes various timbres, musical sound effects, and volume.
Switches and operators for selecting / setting various musical sound elements are provided as appropriate. The selection and setting of these various tone elements may be provided in the form of automatic performance data in the same manner as described above.

The function of the waveform memory WM for storing the waveform data may be performed by any type of data storage device. That is, any of the ROM 101, the RAM 102, the hard disk device 103, and the removable disk device 104 may function as the waveform memory WM. Generally, a hard disk drive 1 which is a large-capacity storage device
03, a removable storage medium such as a CD-ROM or an MO that can be attached to and detached from the removable disk device 104 may function as a waveform database, that is, as a waveform memory WM. Alternatively, a communication interface 1 may be used for a waveform database provided in an external host or server computer.
09 and the communication line, and the necessary waveform data may be downloaded to the hard disk device 103 or the RAM 102 or the like. A software program that executes the waveform forming process according to the present invention under the control of the CPU 100 includes the ROM 101 or the RAM 10
2 or the hard disk device 103. Also, this program is a CD-RO that is removable from the removable disk device 104.
The program may be recorded on a removable recording medium such as M or MO, or the program is received from an external host or server computer via the communication line and the communication interface 109 and downloaded to the hard disk device 103 or the RAM 102 or the like. You may do so.

The waveform memory WM stores waveform data of many unit waveforms. A unit waveform refers to one unit of a waveform that can be selected as one unit. There are a plurality of types of unit waveforms, and the types may be classified from both the musical or sensible meaning and the technical meaning based on the way of reading data. The classification based on the technical meaning is a classification based on whether or not the waveform data is repeatedly read. For convenience, a waveform data that is repeatedly read is called a “loop waveform”, and a waveform data that is not repeatedly read is “loop waveform”. "Non-loop waveform". On the other hand, classification based on musical or emotional meaning is classification based on what portion or section of the sound is appropriate for use in the sound. For example, the unit waveform suitable for use in the rising part of the sound (attack part) is “attack part waveform”, and the unit waveform suitable for use in the falling part of sound (release part) is “release part waveform”. The unit waveform suitable for use in the sustained part of the sound (sustain part) is called “sustain part waveform”, and the unit waveform suitable for use in the connection part between sounds that follow a specific playing style such as slur is “connected”. A unit waveform suitable for use in the sustained part of the sound according to a specific playing style such as vibrato or tremolo, etc., may be appropriately classified and appropriately named, such as `` intermediate playing style waveform ''. it can.

Generally, a unit waveform suitable for use in a part where a delicate articulation (reproduction style) is required is the articulation (reproduction style).
It is preferable to use a "non-loop waveform" that can express the feature of the color deeply. "Non-loop waveform"
Is usually composed of waveforms for a plurality of periods necessary and sufficient to express the characteristics of the articulation (playing style).
On the other hand, it is convenient to use a "loop waveform" for a relatively monotonous sound portion in terms of saving waveform data storage capacity. The “loop waveform” generally includes a waveform for one cycle or an appropriate plurality of cycles. The “loop waveform” can be used alone as a unit waveform of a relatively monotonous sound portion, for example, as a unit waveform of a “sustain portion waveform”. In this case, the waveform of the sustained portion of a series of sounds may be formed by sequentially combining a plurality of “loop waveforms” as appropriate, that is, by sequentially combining a plurality of unit waveforms. This is advantageous in that the Further, in order to smoothly connect the unit waveforms by cross-fade synthesis, it is also advantageous to use a “loop waveform” at the connection portion. Thus, even in a unit waveform including a “non-loop waveform”, it is considered as a preferable embodiment that a “loop waveform” is included in advance at a start end or an end which is a connection point with another unit waveform. On the other hand, needless to say, there may be a unit waveform composed only of the “non-loop waveform”, and in that case, connection with another unit waveform can be smoothly performed by appropriate phase matching processing at the connection point. .

FIG. 2 is a schematic diagram showing a typical example of some unit waveforms stored in the waveform memory WM. For simplicity of illustration, only a part of the actual waveform figure is shown, and only the outline of the location of the waveform is shown in a square frame. In addition,
In the illustrated example, the amplitude peak level of the waveform data is normalized to a fixed value and stored, and a required amplitude envelope is provided at the time of reading / reproducing. Of course, the present invention is not limited to this, and the amplitude peak level of the stored waveform data may not be standardized, and may be stored with an arbitrary amplitude envelope added. In the figure, the horizontal axis is the address of the memory. The waveform data of each unit waveform stored in the waveform memory WM is typically assumed to be PCM-converted waveform sample data. However, the coding form of the waveform data is not limited to PCM,
CM or ADPCM may be used.

FIG. 2A shows an example of an attack portion waveform, which is a preceding non-loop waveform NL.
W and a subsequent loop waveform LW. The start point of this attack part waveform in the waveform memory WM is specified by a specific start address SA. The start point of the loop waveform LW is specified by a specific loop start address LS. FIG. 2B is an example of a unit waveform corresponding to an intermediate waveform such as a sustain portion waveform, and the intermediate waveform is formed of one loop waveform LW. Also in this case, the start point of the intermediate waveform in the waveform memory WM, that is, the start point of the loop waveform LW is specified by a specific loop start address LS. Note that the form of the unit waveform corresponding to the intermediate waveform is not limited to this, and may include a non-loop waveform. For example, one unit waveform may be configured by arranging loop waveforms before and after a predetermined non-loop waveform, respectively. FIG. 2C shows an example of the release portion waveform, which is composed of a preceding loop waveform LW and a subsequent non-loop waveform NLW. The start point of the release portion waveform in the waveform memory WM, that is, the start point of the loop waveform LW is specified by a specific loop start address LS. Further, the end point of the release part waveform is specified by a specific end address EA. As described above, the attack portion waveform or the release portion waveform may include only the non-loop waveform NLW without including the loop waveform LW.

In FIG. 2, individual management information LS, LL, WN, and individual management information for managing each loop waveform LW are shown.
SP is also shown. As described above, the loop start address LS is the address of the start point of the loop waveform LW, and indicates the start address of repeated reading, that is, the loop reading. The loop length data LL is the loop waveform L
This is data indicating the length of W by the number of addresses.
The loop end address (the address at the end of the loop reading) can be specified by “S + LL”. Therefore, the loop waveform LW is repeatedly read, that is, the loop read is performed by repeatedly reading the waveform data from the loop start address LS to the loop end address “LS + LL”.

The loop wave number data WN is data indicating the wave number of the waveform constituting the loop waveform LW, that is, the cycle number. As described above, the loop waveform LW is not limited to one wave, that is, one cycle, and may include a plurality of waves, that is, a plurality of cycles. In this embodiment, since the wave number (WN) and address number (LL) of each loop waveform LW may be arbitrary, loop waveforms whose wave number (WN) and address number (LL) are appropriately different from each other are used. At the time of crossfade synthesis, these data W
The readout rate of each loop waveform is adjusted using N and LL so that the pitch of each loop waveform is adjusted. As described above, the configuration in which loop waveforms having appropriately different wave numbers (WN) and address numbers (LL) can be cross-fade together facilitates and facilitates a free combination of loop waveforms. Thus, controllability and editability in the waveform forming process can be improved.

The initial phase information SP is stored in the loop waveform LW corresponding to the loop start address LS.
Is information indicating the phase of the leading waveform sample data in absolute phase expression. That is, according to this embodiment, it is not necessary to previously align the initial phase of each loop waveform LW and store the waveform data, and instead, the initial phase information SP indicating the initial phase of the loop waveform LW is used. Is stored in the waveform memory WM in association with the waveform data of the loop waveform LW, and necessary phase adjustments and the like are managed using the initial phase information SP, so that the combination of loop waveforms ( At the time of connection or crossfade synthesis), appropriate phase matching can be performed. This eliminates the trouble of having to adjust the initial phase of each loop waveform LW in advance, and accordingly, the versatility of the loop waveform LW and the interoperability between different waveform databases can be enhanced. Therefore, it is very advantageous. Note that not only the initial phase information SP but also other phase management information is stored in the loop waveform LW.
May be stored in the waveform memory WM in association with the waveform data. For example, information indicating the end point of the loop waveform LW (waveform sample data corresponding to the loop end address “LS + LL”) (termination phase information)
May be used as the phase management information. Further, the phase management information such as the initial phase information SP or the terminal phase information is not limited to the absolute phase, but may be represented by a relative phase. For example, an arbitrary phase value may be used as a reference phase, and may be represented by a phase difference of an initial phase (or a terminal phase) with respect to the reference phase, that is, a relative phase. In this embodiment, the data representation of the phase management information such as the initial phase information SP or the terminal phase information uses the radian representation. However, the present invention is not limited to this. There may be. Further, the phase management information is not limited to the information indicating the initial phase and the ending phase of the loop waveform LW. And so on. Of course, without storing the phase management information as management data, waveform data obtained by previously adjusting the initial phase of each loop waveform LW may be stored in the waveform memory WM.

FIGS. 3A and 3B are diagrams showing enlarged examples of some loop waveforms. FIG. 3A shows a loop waveform example 1 in which the initial phase information SP is 0, and FIG. 3B shows a loop waveform example. Example 2 shows an example in which the initial phase information SP is ΔP1, and Example 3 of the loop waveform shown in (c) shows an example in which the initial phase information SP is ΔP2. The portion indicated by the black point in the figure corresponds to 0 phase (the absolute phase value 0). In each example of the drawing, WN = 1. In this example, since the initial phase information SP is represented by an absolute phase, SP = 0 when the initial phase is 0 as shown in FIG. 7A, and SP when the initial phase is ΔP1 as shown in FIG. = ΔP1, SP = ΔP2 when the initial phase is ΔP2 as in (c). On the other hand, for example, when the initial phase information SP is expressed by a relative phase based on the phase value ΔP1 of the absolute phase, the example of (a) is SP = 2π−ΔP1, and the example of (b) is S.
An example of P = 0 and (c) is expressed as SP = ΔP2-ΔP1. In the figure, a zero-phase address ZP indicates an address where waveform sample data of 0 phase (predetermined reference phase) in the loop waveform is located. As is clear from the figure, the initial phase of the loop waveform can be represented by such a zero-phase address ZP. This zero phase address Z
P may be represented by a relative value to the loop start address LS. The phase management information can be expressed in any other appropriate manner.

FIG. 4A is a diagram schematically showing a storage format in the waveform memory WM. The waveform memory WM includes a management data area and a waveform data area. The waveform data area is an area for individually storing waveform data (specific waveform sample data) of many unit waveforms of various types as described above. The management data area is an area that stores various management information necessary for individual waveform data stored in the waveform data area.

FIGS. 4B to 4D illustrate specific storage formats of management data for each waveform data stored in the management data area for some types of unit waveforms. . (B) is a non-loop waveform NL
An example of management data for an attack portion waveform composed of W and a loop waveform LW, (c) is an example of management data for an intermediate waveform composed of only a loop waveform LW, and (d) is a release composed of a loop waveform NL and a non-loop waveform NLW. 6 shows an example of management data for a partial waveform. In the illustrated management data format, type data TYPE
Is data indicating the type of the unit waveform. For example, in the case of (b), “attack portion waveform composed of non-loop waveform NLW and loop waveform LW”
Is indicated by the type data TYPE,
In the case of (c), the type data TYPE indicates "an intermediate waveform consisting of only the loop waveform LW", and in the case of (d), the "release waveform consisting of the loop waveform NL and the non-loop waveform NLW" is referred to as the type. Indicated by data TYPE. In addition, the type data TYPE includes information that can indicate the type according to the various types described above. The identification data ID is data for identifying individual waveform data (for example, a file name of individual waveform data).

The management data includes address data and other data necessary for reading the waveform data of the unit waveform from the waveform data area. In the example of (b), the start address SA, the loop start address LS, the loop length data LL, the loop wave number data WN,
This is the initial phase information SP of the loop waveform. In the example of (c), the information includes a loop start address LS, loop length data LL, loop wave number data WN, initial phase information SP of a loop waveform, and the like. In the example of (c), there are a loop start address LS, loop length data LL, loop wave number data WN, initial phase information SP of a loop waveform, an end address EA, and the like.

By the way, in the loop waveform LW, the number of addresses (the number of samples) per one wave, that is, one cycle waveform is determined from the loop length data LL and the loop wave number data WN. Data indicating the number of addresses (the number of samples) per one wave, that is, one periodic waveform is referred to as wavelength data WL. The wavelength data WL is obtained by the following equation (1). WL = LL / WN (1) As described above, these data (that is, wavelength data WL)
By adjusting the readout rate by using, the readout according to the desired tone pitch can be performed. This makes it possible to perform waveform data readout control in consideration of the difference in the sampling frequency during recording and the difference in the pitch of the original sound, etc., while maintaining the desired playback pitch while maintaining the desired playback pitch. It becomes easy to connect unit waveforms having different pitches or to perform crossfade synthesis.

For the same purpose, the non-loop waveform NL
Also in W, data (wavelength data WL) indicating a representative value of the number of addresses (the number of samples) per one waveform, that is, one cycle of the waveform, is stored in the management data. In that case, typical wavelength data WL
Can be generally obtained from the expression “sampling frequency at recording” 記録 “pitch frequency of original sound”. It should be noted that this type of wavelength data WL is stored in the management data of the unit waveform including only the non-loop waveform NLW, and the management data of the unit waveform including the non-loop waveform NLW and the loop waveform LW includes the loop waveform. For the LW, the wavelength data WL obtained from the above equation (1) may be used for the non-loop waveform NLW.

Next, a basic principle for reading out waveform data from the waveform memory WM in accordance with a desired tone reproduction pitch will be described. A "frequency number" (hereinafter abbreviated as "F number"), which is a constant proportional to the frequency of a desired tone reproduction pitch, is repeatedly added or subtracted (that is, accumulated) at regular time intervals corresponding to a predetermined reproduction sampling frequency. The principle of reading waveform data for reading waveform data using the integer part of the accumulated value as a memory read address is already known. In this embodiment, it is assumed that this principle of waveform reading is followed. Assuming that the frequency of the desired musical sound reproduction pitch is fn and the predetermined reproduction sampling frequency is fs, the standard F number (this is the standard F number Fst (N))
Is expressed by the following equation (2). Fst (N) = fn / fs (2) The standard F number Fst (N) is composed of decimal values and is stored in an appropriate F number table. When specified by information such as a code or a note number, it is read from the F number table.

The standard F number Fst (N) corresponds to the F number when the number of addresses corresponding to one cycle of the frequency fn of the desired tone reproduction pitch is set to one. That is,
This value is such that when Fst (N) is accumulated "fs / fn" times, the accumulation result becomes "1". However, the actual F number is obtained by changing the F number to the reproduction sampling frequency f.
The value should be such that when the accumulation is performed “fs / fn” times in the cycle according to s, the accumulation result becomes the number of addresses corresponding to the wavelength data WL (the number of addresses for one cycle).
The actual F number (referred to as F (N)) is calculated according to the following equation (3) using the standard F number Fst (N) and the wavelength data WL obtained by the above equation (1). F (N) = Fst (N) × WL (3)

Further, as will be described later, a pitch control function PV (vt) for temporally controlling the pitch of the reproduced musical tone.
When time-varying control of the reproduction pitch is performed using the (pitch vector), the actual F number F (N) is calculated according to the following equation (4). However, when there is no pitch change, PV (vt) = 1. F (N) = Fst (N) × WL × PV (vt) (4) The F number F (N) obtained by the above equation (4) is regularly accumulated at a period according to the reproduction sampling frequency fs. By reading the waveform data using the integer part of the accumulated value as a read address (relative address to the start address SA or LS), a waveform having a frequency fn corresponding to a desired tone reproduction pitch is made in accordance with the pitch control function PV (vt). Reproduction and reading can be performed while performing pitch-time fluctuation control. If the read address in this case is indicated by AD, when reading the waveform data of the loop waveform LW, it can be expressed as in the following equation (5). AD = LS + MOD.LL {F (N)} (5) Here, ΣF (N) indicates a value obtained by regularly accumulating the F number F (N) in a cycle according to the reproduction sampling frequency fs. MOD.LL {F (N)} calculates the accumulated value {F (N)
The remainder corresponding to the value corresponding to the loop length data LL of the loop waveform LW as the modulo number, that is, ΔF (N) is LL
The remainder of the quotient divided by. As a result, a read address AD that repeats (loops) in the address range of the loop length data LL starting from the loop start address LS is generated, and the waveform data of the loop waveform LW is repeatedly read according to the read address AD ( Loop readout).

When the non-loop waveform NLW of the attack portion waveform as shown in FIG. 2A is read, the read address AD may be generated according to the following equation (6). read out. AD = SA + ΣF (N) (6) When reading the non-loop waveform NLW of the release portion waveform as shown in FIG. 2C, the read address AD may be generated according to the following equation (7). , The non-loop waveform NLW is read only once. AD = LS + LL + ΣF (N) (7) Note that “LS + LL” indicates the start address of the non-loop waveform NLW of the release portion waveform.

The accumulated value of F number F (N) （F
Using the value of the fractional part of (N), the interpolation operation of the sample value of the waveform data is performed as is generally known, and the waveform data is generated with a resolution more precise than the resolution of the stored waveform data. Can be. By the way, when calculating the F number F (N) by the above equation (4), or when the accumulated value ΣF
In the calculation process of (N), since the number of bits (number of digits) of the calculation is limited, rounding processing of lower bits is performed. As a result, an error occurs, but a predetermined error correction operation may be performed at an appropriate cycle. Especially,
As described later, when two loop waveforms are cross-fade synthesized, by generating a read address AD of both loop waveforms while maintaining a phase difference corresponding to the initial phase shift between the two waveforms, Since the two loop reproduction waveforms are phase-matched, the rounding error causes an error in the phase difference between the read addresses AD of the two and an error in the phase adjustment of the loop reproduction waveform. In order to correct the influence of the rounding error which disturbs the predetermined phase difference between the read addresses AD in such cross-fade synthesis, the read and output addresses AD are forcibly applied at appropriate intervals so as to maintain the predetermined phase difference. In this case, the error correction calculation may be performed. For example, each time 512 waveform data is reproduced (approximately every 10 milliseconds when the reproduction sampling frequency fs is 48 kHz), or every time 4096 sample waveform data is reproduced (every 100 milliseconds). As described above, the accumulated value ΔF (N) may be corrected at a predetermined time interval so that the difference between the read addresses AD of both loop waveforms maintains the difference between the two initial phases SP.

Next, a basic example of a process for connecting loop waveforms and an example of time axis expansion / contraction control will be described. FIG.
(A) shows an example in which the preceding loop waveform A and the succeeding loop waveform B are simply connected. In this case, the connection is established by switching so that the preceding loop waveform A is loop-read a predetermined number of times and then the subsequent loop waveform B is loop-read. In this case, taking into account the initial phase information SP of both, the read start address of the subsequent loop waveform B is set so that the end of the preceding loop waveform A and the beginning of the subsequent loop waveform B at the connection point are in phase. Adjust it. For example, the loop waveform example 2 in FIG. 3B is the preceding loop waveform A, and the loop waveform example 3 in FIG.
Is the succeeding loop waveform B, when the read address reaches the zero-phase address ZP at the end of the loop read of the preceding loop waveform A, switching to reading of the subsequent loop waveform B is performed, and Reading may be started from the zero-phase address ZP.
As described above, even in the case of simple connection, the phase adjustment processing can be performed using the initial phase information SP of both so that the connection can be made smoothly.

In this case, the duration of each loop reproduction waveform, that is, the loop reproduction section, can be variably controlled by time control information. For example, assuming that the end point of the loop reproduction section of the loop waveform A when the time axis expansion and contraction is not performed is tb0, the end of the loop reproduction section of the loop waveform A by performing the time axis expansion and contraction control based on the time control information. The time is controlled to increase or decrease before and after tb0 (for example, tb1 or tb2). Of course, the next loop playback section of the loop waveform B starts from the end of the loop playback section of the loop waveform A that has been subjected to the time axis expansion / contraction control. Further, the time axis expansion / contraction control of the loop playback section of the next loop waveform B can be independently performed according to the unique time control information. That is, by making the time control information temporally variable, unique time axis expansion / contraction control is performed for each loop playback section. Note that the time axis expansion / contraction control can be performed only on the loop playback section without changing the change rate of the read address of the loop waveform, that is, the pitch of the playback tone.

FIG. 5B shows an example in which the preceding loop waveform A and the following loop waveform B are cross-fade synthesized. In this case, in the cross-fade section 1, the preceding loop waveform A is read out in a loop at the same time as the subsequent loop waveform B, and the loop reproduction waveform of the preceding loop waveform A is faded out as indicated by a dotted line in the figure. The amplitude is controlled by the envelope of the falling edge, and the amplitude of the subsequent loop reproduction waveform of the loop waveform B is controlled by the envelope of the fade-in (rising edge) as shown by the dotted line in the figure. Synthesize the loop playback waveform. The cross-fade synthesized loop reproduction waveform changes smoothly from the loop waveform A to the loop waveform B. In the next cross-fade period 2, the loop waveform B is read out in a loop, and the subsequent loop waveform C is also read out in a loop, and the two are cross-fade synthesized as described above.

Also in this case, the duration of the loop reproduction waveform in each cross-fade section can be variably controlled by time control information. For example, assuming that the end point of the crossfade section 1 when the time axis expansion and contraction is not performed is tb0, and the corresponding crossfade curve (the slope of the fade-out and in-envelopes) is XFb0, the corresponding time control information By changing the slope of the cross-fade curve in the cross-fade section (an example of increasing the slope is indicated by XFb1 and an example of reducing the slope is indicated by XFb2), the time length of the cross-fade section 1 can be variably controlled. In the crossfade synthesis, the variable length of the crossfade section in this way means that the speed at which the shape of the synthesized waveform changes from the preceding loop waveform to the subsequent loop waveform is variably controlled by the time control information. Is meant to be. Also in this case, the next crossfade section 2 is
It starts from the end of the crossfade section 1 under the time axis expansion / contraction control. Similarly to the above, the time control information is temporally variable, and the time axis expansion / contraction control of the next crossfade section 2 can be independently performed according to the unique time control information. Hereinafter, in an example described in further detail, it is assumed that connection processing between loop waveforms is performed by cross-fade synthesis.

When the read output of the two loop waveforms is cross-fade synthesized, if the phases of the two do not match,
It is not preferable because the cancellation of the waveform occurs. Therefore, it is necessary to appropriately adjust the phase so that the phases of the read outputs (that is, loop reproduction waveforms) of the two loop waveforms to be cross-fade are matched. For this purpose, the initial phase information SP of each loop waveform is used, and both read addresses AD are used.
Is controlled so that the phases of both loop reproduced waveforms match. In addition, "match phase"
This does not necessarily mean that the phases are strictly matched, but also includes that the phases are appropriately adjusted within a range where the cancellation of the waveform does not occur. That is, “loose phase adjustment” may be used.

As an example for this purpose, the read addresses ADi, ADi of the two loop waveforms to be cross-fade synthesized.
−1 may be calculated according to the following equations (8) and (9). Each variable AD, LS, LL, ΣF in these equations
The meaning of (N) is the same as in the above equation (5), and the subscript i-1 added to each variable indicates that it is a variable for the preceding loop waveform, and the subscript i is the following loop waveform. Is a variable for. That is, ADi-1
Is the read address of the preceding loop waveform, and ADi is the read address of the following loop waveform. SPi-1
Is initial phase information SP (radian expression) of the preceding loop waveform, and SPi is initial phase information S of the following loop waveform.
P (radian representation). In this example, equation (8) is the same as equation (5), and the address offset processing according to the initial phase information SP is not performed on the preceding loop waveform read address ADi-1. ADi-1 = LSi-1 + MOD.LLi-1 {Fi-1 (N)} ... (8) ADi = LSi + MOD.LLi {Fi (N)-(SPi-SPi-1) .times.WLi / 2.pi.} … (9)

In the above equation (9), "-(SPi-S
Pi-1) × WLi / 2π ”is the initial phase SPi and S
The phase difference between Pi-1 and SPi is converted into the number of addresses where one cycle (= 2π) of the wavelength data WLi of the subsequent loop waveform. Thereby, one read address A
Di is offset from the other read address ADi-1 by the number of addresses corresponding to the phase difference "SPi-SPi-1" between the two initial phases SP, and the read phase of the actual waveform data of both is matched. Will be. That is, when the waveform data is read from the address 0 of the initial phase SPi-1 by the read address ADi-1, the read address ADi-1
Address from its initial phase SPi to “SPi-SPi
The waveform data is read from the address offset by the phase difference of "-1", that is, the address corresponding to the phase of SPi- (SPi-SPi-1) = SPi-1. Will fit.

FIG. 6 shows the two series of read addresses ADi.
-1, ADi is the phase difference between the two initial phases SP "SPi
28 is a graph showing a state in which a loop is performed while maintaining a state of being offset by the number of addresses corresponding to “−SPi−1”. The vertical axis is address and the horizontal axis is time. Looping is performed in the address range corresponding to each of the loop length data LLi-1, LLi. As is apparent from this figure, the read address forming process includes a first address signal ADi for reading waveform data of a certain first loop waveform and a second address signal for reading waveform data of a certain second loop waveform. And the second address signal ADi-1 in a different manner according to the difference "SPi-SPi-1" between the initial phases of the first and second loop waveforms. By repeatedly reading out the waveform data of the first and second loop waveforms in accordance with the first and second address signals ADi and ADi-1, respectively, the first and second loop reproduction waveforms formed corresponding to the first and second loop waveforms are read out. Phase adjustment, that is, phase adjustment is performed. In the example of FIG. 6, it is assumed that the number of loop waves of the two loop waveforms is “1”, and each of the loop periods Ti−1 and Ti corresponds to one period T of the reproduction pitch. Then, the time difference ΔT between the loop timings of the two address signals ADi−1 and ADi can be expressed as 2π (ΔT / T) when converted to a radian expression in which one cycle T of the reproduction pitch is 2π, and this is represented by both loop waveforms. Initial phase SP
This corresponds to the phase difference ΔSP between i−1 and SPi. That is, the following relationship holds: ΔSP = SPi−SPi−1 = 2π (ΔT / T) As shown, this initial phase difference Δ
Each address signal ADi-1, ADi loops while maintaining the address shift corresponding to the SP.

By the way, when the cross-fade section is switched, the succeeding loop waveform is switched to the preceding loop waveform, and the next loop waveform is the succeeding loop waveform. To smooth the progress of the read address ADi that has switched from the subsequent loop waveform to the preceding loop waveform, at the end of the cross-fade section, the read address ADi of the subsequent loop waveform is changed to the end point address of the loop waveform (that is, L
The waveform may be switched when S + LL) is reached. Then, the next address to be taken by the read address ADi of the subsequent loop waveform that has been looping while offsetting the address according to the above equation (9) is the loop start address LS, and the next fade-out is performed by switching the cross-fade section. In the sampling period of this, this switches to the preceding loop waveform, and the read address A
Even if Di-1 is calculated according to the above equation (8), a predetermined loop start address LS is specified as a read address, and thus trouble-free control can be performed.

The equations for calculating the two read addresses ADi-1, ADi for crossfade synthesis are given by the above equations (8) and (9).
The present invention is not limited to this, and can be changed as appropriate. For example, as shown in the following equation, the offset may be offset by the number of addresses corresponding to the respective initial phases SPi-1, SPi. ADi-1 = LSi-1 + MOD.LLi-1 {Fi-1 (N)-SPi-1 x WLi-1 / 2π} ... (10) ADi = LSi + MOD.LLi @ Fi (N)-SPix WLi / 2π｝ (11) Also in this case, the time difference between the loop timings of the two read addresses ADi-1 and ADi corresponds to the phase difference “SPi−SPi−1” = ΔSP of the initial phase SP of both.
The readout phases of the actual waveform data of the two match.

Note that each read address A is considered in consideration of the phase difference "SPi-SPi-1" of the initial phase SP as described above.
The process of setting the time difference to the loop timings of Di-1 and ADi and performing loop readout control to substantially match the absolute phases of the loop reproduction waveforms of the two loop waveforms having different initial phases is a cross-over process. The present invention can be applied not only to the case of the fade synthesis, but also to the case where two or more series of loop waveforms are mixed (or interpolated) at an appropriate mixing ratio. Further, the initial phase information SP does not always have to be stored in the management data area in advance. In other words, when it is time to synthesize two loop waveforms each having an arbitrary initial phase, the two loop waveforms are analyzed to determine the difference between the two initial phases, and the two loop waveforms are read out according to the phase difference. By shifting the loop timing of the address, it is possible to substantially match the absolute phases of the loop reproduction waveforms of the two loop waveforms having different initial phases. The phase difference can be analyzed, for example, by finding the phase difference at which the cross-correlation function between the two loop waveforms is the largest.
When each waveform data is stored in the waveform memory WM in a state where the initial phase of each loop waveform is adjusted in advance, the term for the initial phase adjustment in the equations (9), (10), and (11) becomes unnecessary. Of course.

Next, processing for forming a series of sound waveforms will be described. Basically, a waveform of a series of sounds is formed by selecting a plurality of unit waveforms in a desired order, reading out the waveform data from the waveform memory WM, and connecting them together. As an example, the order of selecting unit waveforms, the readout procedure, and the like are specified by preset waveform sequence data. FIG. 4E shows an example of such waveform sequence data. This waveform sequence data is stored in ROM 101, RAM 102,
The data may be stored in advance in an appropriate data storage device such as the hard disk device 103 or the removable disk device 104, and an editing operation such as rewriting of the data content can be performed as appropriate.

The waveform sequence data shown in FIG. 4E corresponds to an example in which a plurality of unit waveforms are combined in a manner as shown in FIG. 7A. FIG.
In (e), first, waveform selection data specifying a specific unit waveform Atk5 is stored together with time data t0. The time data t0 is data indicating a waveform formation start timing. The value “A” specified by the waveform selection data
The management data of the unit waveform having the identification data ID of “Atk5” is read from the waveform memory WM using “tk5” as an index, and based on this, the waveform data of the unit waveform Atk5 is read in a predetermined procedure. For example, the type of the unit waveform Atk5 is an attack portion waveform composed of a non-loop waveform NLW and a loop waveform LW as shown in FIG. The next data XF5 is cross-fade section length data, and indicates a specific cross-fade section length (time length). The crossfade section length corresponds to the slope of the crossfade curve. That is, the crossfade curve is composed of a function that changes linearly in the range of coefficient values from 0 to 1 (or from 1 to 0), and its slope is directly from 0 to 1 (or from 1 to 0).
, Ie, the cross-fade section length. The next data Lp10 is waveform selection data that specifies a specific unit waveform Lp10 consisting of only a loop waveform. Therefore, the data XF5 has the unit waveform Atk.
5 and the next loop waveform Lp1
0 indicates the cross-fade section length when performing cross-fade synthesis with 0.

In the example shown in FIG. 7, thereafter, unit waveforms Lp12, Lp8, and Lp7 consisting of only the loop waveform are sequentially connected,
XF1, XF10,
It is shown that the setting is performed sequentially like XF7 and XF16. Therefore, the data of FIG. 4E is also stored so that a sequence corresponding to the data is obtained. The last unit waveform Rel5 is a release portion waveform composed of a loop waveform LW and a non-loop waveform NLW as shown in FIG. In the crossfade section in which the section length is indicated by the data XF16, crossfade synthesis is performed between the loop waveform Lp7 and the loop waveform at the beginning of the release part waveform Rel5.

In FIG. 7A, time points t1 to t6 are:
The timing at which the unit waveform to be used is switched is shown. These switching points are determined depending on the unique data length of the non-loop waveform and the length of each cross-fade section specified by the data XF, and are appropriately variably controlled along with the time axis expansion / contraction control of waveform data described later. The ordinal number i shown in FIG. 7A is an ordinal number indicating a unit waveform switching step in the waveform sequence, and changes in the order of 1, 2, 3,. FIG.
The state information ST shown in (a) is sequence management information that changes with the progress of the sequence. For example, 0 indicates a sound generation stop state, 1 indicates an attack state, and 2 indicates a unit waveform. , A cross-fade state where cross-fade synthesis of a loop waveform is performed, and a release state when 4.

According to the waveform sequence as described above,
Predetermined unit waveforms are sequentially read out, and at this time, loop readout is appropriately performed for the loop waveforms, and connection between the unit waveforms is smoothly performed by cross-fade synthesis between the loop waveforms. A sound waveform is formed. The series of sounds is not limited to one sound or note, but may be a plurality of sounds or notes (that is, phrases). At that time, when cross-fading the loop waveforms,
As described above, loop reading is performed while performing phase matching using the respective initial phase information SP.
The waveform sequence data for forming a desired series of sound waveforms is not limited to the case where data stored in a memory is used in advance, and may be created in real time according to a player's real time selection / setting operation. Or change it.

Further, in this embodiment, various tone elements of the waveform generated according to the above-described waveform sequence are variably controlled by various parameters. Typical examples of musical tone elements to be controlled are pitch,
Tone, amplitude, time, etc. The control amount for each tone element is given in the form of temporally variable envelope data. FIGS. 7B to 7D show examples of some tone element control data. FIG. 7B shows an example of data (time control information) for controlling a time element.
(C) is an example of data for controlling the amplitude element, and (d) is an example of data for controlling the pitch element. Such a time-change pattern of various control data, that is, an envelope shape may be prepared in advance as a template, or a user may freely create a desired template. Each template is
The information may be stored in an appropriate memory or table or the like in advance, or may be formed by an appropriate operation or the like without necessarily being stored in the memory or table or the like in advance.

Data for designating a predetermined template of these various tone element control data is prepared as vector data corresponding to each waveform sequence.
Vector data specifying time element control data (time control information) as shown in FIG.
I will say that. By this time vector TV,
A predetermined envelope-shaped (that is, time-varying) template of time element control data (time control information) can be specified and generated. Vector data specifying the amplitude element control data as shown in FIG. 7C is referred to as an amplitude vector AV. With this amplitude vector AV, a template of a predetermined amplitude envelope is specified,
The amplitude envelope can be generated. FIG.
Vector data specifying the pitch element control data as in (d) is referred to as a pitch vector PV. With the pitch vector PV, a template of a predetermined pitch fluctuation envelope can be specified, and the pitch fluctuation envelope can be generated. The pitch fluctuation envelope value based on the pitch vector PV is expressed as a ratio to the F number, and is “1” when the pitch is not changed, “1” or more when the pitch is increased, and “1” when the pitch is decreased. 1 ”.

The control of the time element performed based on the time vector TV means the control of extending or compressing the length of the waveform data on the time axis (that is, the duration time) (hereinafter, this control is referred to as time axis expansion and contraction). Control, abbreviated as TSC control). This kind of time axis expansion / contraction control, ie, TSC
It is desirable that the control can control the existence time length of the waveform data independently of the musical tone reproduction pitch. The time axis expansion / contraction control information based on the time vector TV is
Data showing the time axis expansion / contraction ratio (this is called CRate)
For example, it is represented by “1” when time axis expansion / contraction is not performed, a value less than “1” when time axis expansion is performed, and a value “1” or more when time axis compression is performed.

Further, the time axis expansion / contraction control, that is, TSC control will be described. In the case of a loop waveform, basically, by varying the number of loops, it is possible to relatively easily and variably control the time length of the entire loop reproduction waveform independently of the tone reproduction pitch. That is, when a specific crossfade curve is specified by the crossfade section length data XF, the crossfade section length (time length or number of loops) is determined accordingly. Here, the inclination of the crossfade curve is variably controlled by the time axis expansion / contraction ratio indicated by the time vector TV, whereby the speed of the crossfade is variably controlled, and the time length of the crossfade section is variably controlled. In the meantime, since the musical tone reproduction pitch is not affected, the loop length is variably controlled, so that the time length of the cross fade section is variably controlled.

On the other hand, in the case of a non-loop waveform, it is not so easy to variably control the existence time length on the time axis independently of the tone reproduction pitch. However, the time axis expansion / contraction control of a non-loop waveform can be performed by using the “time axis expansion / contraction control of waveform data” technique, which is a new technique already applied for by the present applicant. In other words, to summarize briefly, a non-loop waveform consisting of a fixed amount of waveform data is
In order to expand and contract the waveform data existence time length on the time axis while maintaining a constant reproduction sampling frequency and a predetermined reproduction pitch, in the case of compression, skip the appropriate part of the waveform data and read it out. In such a case, an appropriate portion of the waveform data is repeatedly read out,
Then, cross-fade synthesis is performed in order to remove discontinuity of waveform data due to skipping or partially repeated reading. This method can be applied to the TSC control in the non-loop waveform portion in the present embodiment, and can also be applied to the TSC control in the loop waveform portion as necessary.

The horizontal axis in FIGS. 7B to 7D is the time axis. However, this variable is not the actual time but
This is a time axis (this is referred to as a virtual time vt) whose expansion and contraction is controlled in accordance with the time axis expansion and contraction ratio data CRate based on the time vector TV as shown in FIG. That is, in the reproduced waveform data as shown in FIG. 7A, the existence time on the time axis is controlled to expand or contract according to the time vector TV shown in FIG. 7B. , The time axis of the control data based on each vector shown in FIGS. 7B to 7D needs to be expanded and contracted.
This is because the existence time of the control data of each tone element on the time axis also needs to be expanded and contracted in synchronization with the expansion and contraction of the time axis of the reproduced waveform data. For this reason, the virtual time vt is used as a time variable of the pitch control function PV (vt) in the equation (4). The virtual time vt is also used as a time variable of the amplitude envelope function AV (vt) and the pitch fluctuation envelope function PV (vt).
Is used.

Next, an example of a processing program for performing a waveform forming process by the computer in FIG. 1 according to the waveform sequence shown in FIG. 4 (e) or FIG. 7 (a) will be described with reference to FIGS. explain. FIG. 8 shows an outline of a process of advancing a waveform sequence for waveform reproduction. First, waveform sequence data to be reproduced is specified (step S1). Next, state S
T is set to "0" to prepare for starting waveform reproduction (step S2). In the next step S3, the presence or absence of a stop event STOP is checked. If the stop event STOP is not given, the time data t0
It is checked whether or not the waveform formation start timing indicated by (2) has arrived (step S4). If NO, the process returns to step S3 and repeats steps S3 and S4. When the waveform formation start timing has arrived and YES is determined in step S4, the state ST is set to "1" and the ordinal number i is set to "1" to prepare for reproducing the first unit waveform, that is, the attack part waveform. (Step S5). That is, each management data of the corresponding attack part waveform (for example, Atk5 in FIGS. 4E and 7A) is read from the management data area of the waveform memory WM,
The waveform data of the attack portion waveform Atk5 is stored in the waveform memory W
Prepare to start reading from the M waveform data area. Next, it is checked whether the state ST has become "2" (step S6). If NO, the process waits until the state ST becomes "2".

FIG. 9 shows the reproduction sampling frequency fs of 1
An example of interrupt processing that is regularly performed in each cycle will be described.
The processing of reading and forming the waveform data per sample is performed in this one interruption processing. Therefore, while the process of FIG. 8 is waiting at step S6, FIG.
Are repeatedly executed to read and form waveform data. In this interrupt processing,
First, it is checked whether or not the state ST is "0" (step S20). If "0", the interrupt is immediately terminated. If it is not "0", the process proceeds to the next step S21, and the virtual time vt is calculated. This calculation is based on the time expansion / contraction control data CRa specified by the time vector TV.
This is done by accumulating the current value of te. Next, according to the obtained virtual time vt, the time expansion / contraction control data TV (vt) based on the template corresponding to the time vector TV (that is, it corresponds to a new current value of CRate. Generate a current value PV (vt) (hereinafter simply referred to as a “pitch vector value PV (vt)”) of a pitch fluctuation envelope function based on a template corresponding to the “time vector value TV (vt)” and the pitch vector. (Step S2
2). In other words, the instantaneous value of the time expansion / contraction control data CRate and the instantaneous value of the pitch fluctuation envelope as shown in FIGS. Generate).

Next, it is checked whether or not the state ST is "3" (step S23). If the state is not the loop waveform reading state, the determination is NO, and the process goes to step S24 to perform the F number generation processing. In this F number generation processing, an F number F (N) for reading a non-loop waveform is generated according to the above equation (4). That is, the standard F corresponding to the pitch of the musical tone to be reproduced
Based on the number Fst (N), the wavelength data WL, and the pitch vector value PV (vt), a pitch-controlled F number F (N) to be used for the waveform read address calculation is obtained.

Next, at step S25, the F number F
By accumulating (N) for each sampling period, basically, a read address ADi for reading a non-loop waveform as shown in the above equation (6) or (7) is generated. However, the generation of the read address ADi is performed in consideration of the state ST. When the state ST is "1" or "4", the non-loop waveform NLW (non-loop waveform of the attack portion or the release portion) is read. A read address ADi is generated, but the state S
When T is "2" (corresponding to a transient state of waveform switching), a read address ADi for reading a loop waveform LW (a non-loop waveform in an attack portion or release portion waveform) is generated. When performing the time axis expansion / contraction control in the non-loop waveform portion, this step S2
In 5, the generation of the read address ADi is further appropriately controlled according to the time vector value TV (vt), that is, the time axis expansion / contraction ratio CRate. Next, in step S26, the waveform data is read from the waveform data area of the waveform memory WM based on the read address ADi. At this time, as described above, it is preferable to perform interpolation between waveform samples in accordance with the decimal part of the accumulated value of the F number F (N) (that is, the decimal part of the read address ADi).

In the next step S27, it is checked whether or not the state ST is "1" and has reached the end address ANend of the non-loop waveform portion of the attack portion waveform. The end address ANend of the non-loop waveform NLW portion of the attack portion waveform is the address “LS-1” immediately before the loop start address LS (see FIG. 2A) of the attack portion waveform, and the loop in the management data. It can be obtained based on the start address LS. Read address A
If Di has not yet reached the end address ANend of the non-loop waveform of the attack portion waveform (that is, during reading of the non-loop waveform), step S27 is NO,
Go to step S28. In step S28, the state ST is "4" and the end address E of the release portion waveform
A (see FIG. 2C) is checked. The read address ADi is the end address EA of the release section waveform
If has not reached yet, step S28 is NO and the procedure goes to step S29.

In step S29, the virtual time v
An amplitude vector value AV (vt) is generated according to t. In other words, the instantaneous value of the amplitude envelope based on the amplitude vector AV as shown in FIG. Then, the above step S26
Is controlled by the amplitude vector value AV (vt) (step S30).
The amplitude-controlled waveform sample data is output to the digital / analog converter (DAC) of the waveform interface 107 via the bus 111 (step S3).
1). Note that when waveform data for a plurality of channels is formed simultaneously and in parallel, the above-described steps S20 to S30 are performed.
Is performed a plurality of times for each channel, a channel combining step is provided after step S30, and the waveform sample data of each channel is summed and output in step S31.

As described above, the reproduction sampling frequency fs
The interrupt process of FIG. 9 is executed for each cycle of the above, and waveform data for one sample is generated. As a result, the non-loop waveform NLW of the attack portion waveform, which is the first unit waveform, and the subsequent loop waveform LW are sequentially read. After one reading of the loop waveform LW is completed, the read address A
When Di reaches the end address ANend of the non-loop waveform portion of the attack portion waveform, step S27 proceeds to YE
In S, the process proceeds to step S32, and the state ST is set to "2". Thereafter, steps S29 to S31
go to.

Returning to FIG. 8, in step S6, state S
When it is detected that T has become "2", the flow goes to step S7 to prepare for reading out the next waveform. That is, the content of the next step in the waveform sequence is read (FIG. 4E), the information of the waveform data to be read next is obtained, and necessary preparation processing is performed accordingly. FIG.
In the example of (e), the crossfade section length data XF5 is set next to the sequence step in which Atk5 is read.
And the subsequent waveform selection data for selecting the loop waveform Lp10 are read from the waveform sequence data memory unit.
In the next step S8, the type of the next unit waveform is determined. If it is a loop waveform, the process goes to step S9, where the state ST is set to "3" and the ordinal i is increased by one. Then, the process proceeds to step S6, and waits until the state ST becomes “2”. Step S
8, the loop waveform LW at the beginning like the release portion waveform
If the head loop waveform LW has not been read out yet, it is determined to be a loop waveform, and the process proceeds to step S9. In addition, in order to switch the state ST to “3” after continuing the state ST = “2” which is a transient state to the loop end of the loop waveform, in step S9, the read address reaches the loop end (LS + LL). After confirming this, the state ST is preferably switched to “3” and the ordinal i is increased by one.

On the other hand, in FIG. 9, when the state ST is set to "3", the step S23 branches to YES and the routine goes to a routine for performing loop read control. Step S33
Is an "F number generation process" similar to step S24, but for the purpose of crossfading, the F number Fi-1 (N) of the preceding loop waveform and the F number Fi (N) of the following loop waveform. Are separately generated in accordance with the above equation (4). Wavelength data WL of each loop waveform
Since the (number of addresses per wave) is arbitrary, the calculation of the above equation (4) is performed using the respective wavelength data WLi-1 and WLi, and the F number Fi-1 (N),
It is necessary to find Fi (N). In this case, the preceding loop waveform is the loop waveform added to the end of the attack part waveform, and the subsequent loop waveform is the newly selected loop waveform Lp10. The next step S34 is a process for generating the read address AD in the same manner as in step S25. However, for the purpose of loop reading and cross-fade synthesis, the read address ADi-1 of the preceding loop waveform is calculated according to the above equation (8). Calculate,
The read address ADi of the subsequent loop waveform is calculated according to the above equation (9). In the next step S35, according to the read addresses ADi-1, ADi, the waveform data of the corresponding loop waveforms are read out, and the inter-sample interpolation operation is performed.

In the next step S36, the current virtual time vt is applied as a time variable of a crossfade function XF having a slope characteristic determined by the crossfade section length data XF5, and the current value X of the crossfade coefficient is obtained.
Generate F (vt). For example, the crossfade function X
When F is a linear function, the current value XF (vt) of the crossfade coefficient can be obtained by multiplying the value of the virtual time vt by the value of the data XF5.
That is, when the time expansion / contraction ratio is 1, the virtual time vt corresponds to the real time and is a time function that increases by one for each sampling period.
, A linear function having a gradient corresponding to the value of the data XF5 can be created, and this can be used as a cross-fade function XF (vt). This can be expressed as follows: XF (vt) = XF5 × vt + C Here, C is an arbitrary constant. When the increase / decrease rate (that is, the slope) of the virtual time vt changes due to the change of the time vector TV, the crossfade function XF (v
The slope of t) also changes. Conversely, this is equivalent to variably controlling the slope of the crossfade curve having the slope characteristic determined by the crossfade section length data XF5 according to the current value of the time vector TV. In this way, it is possible to generate the crossfade function XF (vt) in which the time axis expansion / contraction control is performed according to the time vector TV. As a generalization, assuming that the crossfade function XF is represented by an arithmetic function f (x) or a template tbl (x) for a variable x, FX = f (vt) or tbl ( v
t). Note that, specifically, assuming that the crossfade function XF (vt) is composed of decimal values that change from 0 to 1, XF (vt) is used as a cross-fade coefficient for fade-in, and a fade-out coefficient for fade-out is used. The crossfade coefficient uses "1-XF (vt)".

In the next step S37, it is checked whether or not a predetermined crossfade end point XFend has been reached. The crossfade end point XFend indicates the end point of the crossfade section. That is, when the value of the crossfade function XF (vt), that is, the crossfade coefficient value on the fade-in side (subsequent waveform side) reaches the maximum value “1”, “1” is held as it is. After the fade coefficient value reaches the maximum value “1”, the read-out address ADi on the fade-in side (subsequent waveform side) becomes the address of the last point of the loop waveform (that is, LS + LL).
Is reached, it is determined as the cross-fade end point XFend. If the crossfade end point XFend has not yet been reached, step S37 is NO and step S37
38, the read waveform data (loop reproduction waveform) of each loop waveform according to the value of the cross-fade function XF (vt)
Are cross-fade synthesized. Then, from step S29
Go to S31.

The interrupt processing shown in FIG. 9 is executed for each cycle of the reproduction sampling frequency fs, and the steps S33 to S33 are executed.
The routine of 38 is repeatedly executed, and repeated reading of each loop waveform and cross-fade synthesis of the read output waveform data (loop reproduction waveform) are performed. Eventually, when the cross-fade end point XFend is reached, step S37 becomes YES, and the process goes to step S39 to set the state ST to "2". Thus, the crossfade synthesis processing for one crossfade section is completed.

Returning to FIG. 8, in step S6, state S
When it is detected that T has become "2", the flow goes to step S7 to prepare for reading out the next waveform. In the case of the example of FIG. 4E, as the next to the sequence step of reading Lp10, the waveform selection data for selecting the cross-fade section length data XF1 and the subsequent loop waveform Lp12 is read from the waveform sequence data memory unit. Thus,
The loop reading process and the cross-fade synthesizing process similar to the above are performed on different loop waveforms this time. That is, in the case of the present example, the preceding loop waveform is the loop waveform L which was the previous succeeding loop waveform.
p10, and the subsequent loop waveform is the newly selected loop waveform Lp12.

In this way, the loop readout processing and the cross-fade synthesis processing are performed while sequentially switching the loop waveforms according to the predetermined waveform sequence, and the waveforms constituting the partial sections of the sound are smoothly connected. Formed one after another. Eventually, step S7 in FIG.
As a waveform sequence step following the last loop waveform Lp7, the cross-fade section length data X
When F16 and the waveform selection data for selecting the release portion waveform Rel are read (FIG. 4E), the data of the loop waveform LW at the start end of the release portion waveform Rel is acquired as information of the waveform data to be read next, A necessary preparation process is performed accordingly. Then, the next step S8
Then, it is determined that the next waveform type is a loop waveform, and the process goes to step S9 to set the state ST to "3". Then, the process proceeds to step S6, and waits until the state ST becomes “2”. In this way, by the interrupt processing of FIG. 9, the loop read processing of the last loop waveform Lp7 and the loop waveform LW at the beginning of the release part waveform Rel and the crossfade synthesis processing are performed with the crossfade section length corresponding to the data XF16, Will be performed. When this last crossfade section ends, FIG.
In step S39, the state ST is set to "2".

Then, in step S7 of FIG. 8, the release portion waveform R
The data of the non-loop waveform NLW of el is acquired, and necessary preparation processing is performed accordingly. Then, in the next step S8, the type of the next waveform is the release portion waveform Re.
It is determined that the waveform is the non-loop waveform NLW of 1 and the process goes to step S10 to set the state ST to "4". Next, in step S11, the process waits until the state ST becomes “0”. On the other hand, in FIG. 9, NO in step S23
Then, the process branches to a non-loop waveform reading routine, and the release portion waveform R is obtained by the processes of steps S25 and S26.
An address ADi for reading out the non-loop waveform NLW of el is generated, the waveform data is sequentially read out, and inter-sample interpolation and the like are performed. Eventually, the read address ADi becomes the end address EA of the release portion waveform Rel.
Is reached, step S28 is YES, and the process goes to step S40 to set the state ST to "0".
In this way, the sound generation ends. Step S11 in FIG.
After confirming that the state ST has become "0", the process returns to step S3, and the loop of steps S3 and S4 is repeated. When the timing to generate the next sound in the waveform sequence comes, as described above, step S4
Is YES, and the same processing as described above is started. On the other hand, when the stop event STOP is generated based on the sequence data or in response to a manual operation or the like, the processing in FIG. 8 ends. That is, a waveform sequence can be formed so that a plurality of sounds are generated intermittently in one waveform sequence. That is, not only a musical tone waveform corresponding to one note can be described by one waveform sequence, but also a musical tone waveform corresponding to a plurality of notes (phrases) can be described.

In the above example, the transition state S
It has been described that the state ST is switched to the state ST = “3” after T = “2” is continued until the loop end of the loop waveform. As a result, the beginning of the cross-fade section matches the loop start address LS of the preceding loop waveform. However, the present invention is not limited to this, and the state ST = "2" may be immediately switched to the state ST = "3" in step 9 of FIG. 8 without continuing until the loop end of the loop waveform. In that case, the crossfade section starts from an arbitrary address of the preceding loop waveform, but the start value of the read address ADi of the subsequent loop waveform is offset by the crossfade start address (further than the offset corresponding to the initial phase difference). Offset).

FIG. 11 is a diagram showing a specific example of TSC control which can be realized by the embodiment described above. (A)
Shows an example of an original reproduction waveform in a case where a plurality of loop waveforms # 1, # 2 to # 8, and # 9 are sequentially switched to perform loop reproduction and cross-fade synthesis to form a series of sound waveforms. As shown in (b),
It is a waveform example obtained by maintaining the time axis expansion / contraction ratio CRate of the time vector TV at “1” during the entire sound generation period. Note that the loop waveform # 1 is the attack portion waveform A
A loop waveform included at the end of tk, a loop waveform # 9 is a loop waveform included at the beginning of the release portion waveform Rel, and the other loop waveforms # 2 to # 8 are each a single loop waveform. FIG. 3C shows a time vector TV as shown in FIG.
3 shows an example of a reproduced waveform obtained when the time axis expansion / contraction ratio CRate of FIG. In this case,
Generally, the time axis expansion / contraction ratio C of the time vector TV in the loop reproduction section (cross-fade section) of the loop waveforms # 1 to # 5.
Rate takes an appropriate value of 1 or more, and loop waveform # 5
In the loop playback section (cross-fade section) # 9, the time axis expansion / contraction ratio CRate of the time vector TV takes an appropriate value of less than 1. FIGS. 11A and 11C show an example of a state in which the amplitude envelope of the waveform has been controlled according to the amplitude vector AV. As described above, the time axis of the amplitude vector AV is controlled to expand and contract in accordance with the time variation of the time vector TV, so that an appropriate amplitude envelope is provided in synchronization with the change in the time axis of the waveform. In other words, the basic characteristics of the amplitude envelope in this case show a crescendo characteristic in which the amplitude gradually increases from the attack portion to a point in time where the intermediate predetermined loop waveform # 5 switches,
It shows a decrescendo characteristic in which the amplitude gradually decreases from that point to the release part. Even if the time axis expansion / contraction control of the waveform is performed, the amplitude envelope is controlled in time axis expansion / contraction in conjunction with the control, whereby a predetermined loop waveform # It is possible to maintain the basic characteristic that the crescendo characteristic is exhibited until around the switching point of 5, and thereafter the crescendo characteristic is exhibited. The expansion / contraction control of the time axis characteristics of other tone elements linked to the time axis expansion / contraction control of such a waveform is one in which the time axis control of each tone element does not fall apart but shows changes synchronously and integrally. Is good.

FIG. 12 is a diagram showing another specific example of the TSC control which can be realized by the embodiment described above. The example shown in the figure shows an example in which a waveform having a vibrato component is compressed by using a plurality of loop waveforms, and the waveform is reproduced by controlling the expansion and contraction on the time axis. That is, an example is shown in which a waveform having high-quality articulation like vibrato can be formed with rich controllability by combining a plurality of loop waveforms. FIG. 2A illustrates an original waveform including vibrato. In this original waveform, not only the waveform pitch fluctuates in one cycle of vibrato, but also the amplitude fluctuates.
(B) shows an example in which a plurality of loop waveforms a1, a2, a3, a4 are dispersedly extracted from the original waveform of (a). For example, as these loop waveforms a1 to a4, those having different waveform shapes (tone colors) are selected, cut out with an appropriate data size, and a standardization process is performed on the pitch and amplitude, and the necessary management data is obtained as described above. And the waveform data is stored in the waveform memory WM. As described above, this reading method uses the loop waveforms a1 to a4
Are sequentially read out in a loop and cross-fade synthesized.

FIG. 12C shows an example of a pitch vector PV (pitch change envelope) showing a pitch change characteristic during one vibrato cycle. In the drawing, the pitch change pattern of the pitch vector PV is a pattern which starts from a high pitch, shifts to a low pitch, and finally returns to a high pitch. However, the present invention is not limited to this, and other patterns (for example, from a low pitch to a high pitch) may be used. To a low pitch, or a pattern starting from an intermediate pitch and returning to a high pitch → low pitch → intermediate pitch).

FIG. 12D illustrates a cross-fade control waveform for each of the loop waveforms a1 to a4 read out from the loop. At first, the loop waveforms a1 and a2 are loop-read (repeatedly read) at a pitch according to the pitch vector PV of (c).
The amplitude of fade-in is controlled for the loop reproduction waveform No. 2 to synthesize the two. As a result, the waveform shape cross-fades from the loop waveforms a1 to a2 and changes sequentially, and the pitch of the cross-fade composite waveform changes sequentially at a pitch according to the pitch vector PV. Thereafter, the waveforms are sequentially switched in the same manner, and crossfade synthesis is performed at a2 and a3, then at a3 and a4, and then at a4 and a1. FIG. 12E shows an amplitude vector A indicating an amplitude variation characteristic during one vibrato cycle.
An example of V (amplitude change envelope) is shown. An amplitude envelope corresponding to the amplitude vector AV to be added to the cross-fade synthesized waveform is added. Of course, the application of the amplitude envelope according to the amplitude vector AV may be performed before the crossfade synthesis, or may be performed simultaneously with the crossfade synthesis.

FIG. 12F shows the synthesized waveform data. The waveform data is changed by smoothly cross-fading the waveform shape from the loop waveform a1 to a4 in order from one cycle of the vibrato and changing the pitch in accordance with the pitch vector PV during one cycle of the vibrato. Is attached. By repeating the above-described process of synthesizing the waveform data for one vibrato cycle, it is possible to synthesize waveform data over a plurality of vibrato cycles. In this case, the pitch vector PV and the amplitude vector AV for one cycle of the vibrato as shown in (c) and (e) may be looped by the required number of vibrato cycles.

In the example of FIG. 12, the time length of each cross-fade section shown in FIG.
In the case where the TSC control is performed without changing the tone reproduction pitch (the change rate of the loop waveform read address) by performing the TSC control according to Thus, the vibrato frequency can be controlled. In this case, if the time vector TV is prepared corresponding to one cycle of vibrato similarly to the pitch vector PV and the amplitude vector AV as shown in FIGS. The time vector TV may be looped by the required number of vibrato periods. Note that the pitch vector PV
And the output value of the amplitude vector AV are the time vector TV
Is described as a function of the virtual time vt generated based on the time vector TV, so that the time axes of the pitch vector PV and the amplitude vector AV are also controlled to expand and contract according to the time vector TV. On the other hand, by shifting the pitch change envelope characteristic indicated by the pitch vector PV up and down,
The tone reproduction pitch of the vibrato waveform can be variably controlled. In this case, by not changing the time vector TV, it is possible to control so as to keep the time length of one vibrato cycle constant regardless of the musical sound reproduction pitch.

In the above description, each of the loop waveforms a1 to a4
Has been described in which the pitch and amplitude are normalized and stored in the waveform memory WM. However, a loop waveform whose pitch or amplitude is not standardized is used, and the pitch and amplitude are stored in the pitch vector PV and the amplitude. It can also be controlled by vector AV. In this case, the waveform reading speed is controlled by the difference between the pitch unique to the loop waveform and the pitch vector PV, and the amplitude unique to the loop waveform and the amplitude vector A
Level control may be performed based on the difference from V.

Note that a music piece can be automatically played by combining a plurality of waveform sequences.
For this purpose, it is preferable to use a note sequence corresponding to the note sequence of the musical score. Note sequence is MI
The automatic performance sequence data may be the same as the automatic performance sequence data of DI. For example, a note, that is, a pitch of a musical tone to be reproduced and a sounding timing, and a waveform sequence to be used for generation of the note and each Just specify a vector. Alternatively, event data specifying a note, event data specifying a waveform sequence, and event data specifying each vector may be generated separately according to an automatic performance sequence, or may be generated according to event data specifying a note. Alternatively, other event data may be generated.

The contents of each waveform sequence and the contents of vector data TV, AV and PV corresponding to each waveform sequence can be freely edited by the user. FIG. 10A shows a flowchart example of the vector edit processing. First, a user selects a desired waveform sequence and specifies which tone element vector of various tone elements corresponding to the waveform sequence is to be changed (step S41). Next, according to the operation of the user, the vector data of the designated musical sound element is changed to replace it with another template, or the vector data is not changed, and the content of the corresponding template, that is, the vector data Processing such as appropriately changing the contents of the specified specific time variation control data is performed (step S42). FIG.
(B) shows a flowchart example of the waveform sequence editing process. First, a desired waveform sequence is selected by the user's operation, and a position of the unit waveform in the waveform sequence to be edited is designated (step S43). Next, according to the user's operation, an arbitrary unit waveform can be additionally inserted at the specified position, a unit waveform at the specified position can be deleted, or a unit waveform at the specified position can be changed to another unit. Processing such as changing to a waveform or changing the value of the cross-fade section length data XF at the designated position is performed (step S44).

In the above embodiment, the processing for forming the waveform sample data is performed by the interrupt processing shown in FIG. 9, and the interrupt processing for each cycle of the reproduction sampling frequency fs is performed for one sample in the sampling cycle. Is formed. However, the present invention is not limited to this, and as is known in the software sound source technology already proposed by the present applicant, waveform sample data for a large number of samples corresponding to one frame section is collectively formed in a short time. May be stored in an output buffer, and reading of the waveform sample data from the output buffer may be performed for each cycle of the reproduction sampling frequency fs. The waveform forming process according to the present invention is not limited to the waveform forming process based on the software program, but may be performed by a DSP device configured to operate with the same waveform forming process microprogram as in the above-described embodiment. Alternatively, a dedicated hardware circuit may be configured to perform the same waveform forming processing as in the above embodiment using an LSI circuit or a discrete circuit.

[0085]

As described above, according to the present invention, for a plurality of different loop playback waveform sections, the playback time length, that is, the loop playback time, is changed in accordance with the current value of the temporally variable time control signal. Since the length of time during which the sound corresponding to the waveform exists is controlled to expand or contract, it is possible to add unique changes to the multiple loop playback waveform sections that make up the sound, and to form a waveform with high controllability. The effect is excellent. Since the controllability of the loop reproduction waveform is improved in this manner, a loop waveform having a relatively simple waveform structure (for example, having a small memory capacity) can be converted into a high-quality waveform in consideration of sound articulation (playing style). It has an excellent effect that it can be easily used even in the formation scene. Further, since the time length of each loop reproduction waveform section is controlled to be expanded or contracted at any time according to the current value of the time control signal, the time length of a certain section of a plurality of loop reproduction waveform sections constituting a sound is set. Can be combined to expand the time length of another section, and so on.It is possible to combine multiple loop playback waveform sections with various time variations, and only conventional monotonous control is possible. This provides an excellent effect that a waveform with high controllability can be formed for a musical tone of a loop portion that was not present.

Further, according to the present invention, while the time lapse of the musical tone waveform is controlled to expand and contract by the time control signal for controlling the time lapse, the time of the musical tone control signal which changes with time for controlling the musical tone waveform is controlled. Since the elapse of time is also controlled by the time control signal, when the waveform control time is controlled by the time control signal, not only the waveform but also the tone control signal for controlling the waveform, that is, the amplitude envelope and the pitch change. By simultaneously controlling the expansion and contraction of the time axis of the envelope and the like, there is an excellent effect that both the musical sound waveform and the tone control signal for controlling the waveform can be controlled in synchronization with the expansion and contraction of the time axis.

[Brief description of the drawings]

FIG. 1 is a block diagram schematically illustrating a hardware configuration of an embodiment of a waveform forming apparatus according to the present invention.

FIG. 2 is a diagram conceptually showing some examples of unit waveforms stored in a waveform memory.

FIG. 3 is a waveform chart showing some specific examples of a loop waveform having an arbitrary initial phase.

FIG. 4 is a conceptual diagram showing an example of a storage format of a waveform memory and an example of waveform sequence data.

FIG. 5 is a conceptual diagram showing an example of connection between loop waveforms for simple connection and cross-fade synthesis.

FIG. 6 shows an example in which loop control is performed by shifting read addresses for reading two loop waveforms to be cross-fade synthesized in accordance with a difference between initial phases of the two loop waveforms.

FIG. 7 is a conceptual diagram showing an example of a waveform sequence and an example of vector data for musical tone element control corresponding to the waveform sequence.

FIG. 8 is a flowchart illustrating an example of a waveform sequence process.

FIG. 9 is a flowchart illustrating an example of a waveform sample data forming process executed as an interrupt process.

10A is a flowchart illustrating an example of a vector edit process, and FIG. 10B is a flowchart illustrating an example of a waveform sequence edit process.

FIG. 11 is an explanatory diagram showing a specific example of time axis expansion / contraction control of a waveform including a loop reproduction section.

FIG. 12 is an explanatory diagram showing another specific example of time axis expansion / contraction control of a waveform including a loop reproduction section.

[Explanation of symbols]

 100 CPU 101 ROM 102 RAM 103 Hard Disk Device 104 Removable Disk Device 105 Display 106 Input Operating Device 107 Waveform Interface 108 Timer 109 Communication Interface 110 MIDI Interface 111 Bus WM Waveform Memory

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Motoichi Tamura 10-1 Nakazawacho, Hamamatsu City, Shizuoka Prefecture Yamaha Corporation

Claims (9)

[Claims] 1. A time control signal generating section for controlling the expansion and contraction of a waveform reproduction time and generating a time control signal which is variable in time, and a predetermined loop waveform in a predetermined section in a sound generation period. Is repeated to generate a loop reproduction waveform, form a waveform of the sound including a plurality of different loop reproduction waveform sections, and set the time length of each loop reproduction waveform section according to the current value of the time control signal. A waveform forming apparatus comprising: a waveform forming unit that controls expansion and contraction. 2. The waveform forming apparatus according to claim 1, wherein the time control signal changes with time according to a predetermined function, and the function uses a current value of the time control signal as a time variable. . 3. The waveform forming section generates a first loop reproduction waveform by repeating a predetermined first loop waveform in the predetermined section, and repeats a second loop waveform by repeating a second loop waveform. 2. The waveform forming apparatus according to claim 1, wherein a reproduced waveform is generated, and the first and second loop reproduced waveforms are cross-fade synthesized in the predetermined section to form a synthesized loop reproduced waveform. 4. The waveform forming section generates a non-loop waveform that is not repeated in another predetermined section in the sound generation period, and controls a time length of the section of the non-loop waveform in accordance with the time control signal. The waveform forming device according to claim 1. 5. A first control signal generator for generating a time-varying musical tone control signal, a second control signal generator for generating a time control signal for controlling the passage of time, and forming a musical tone waveform. Wherein the time lapse of a musical tone waveform to be formed is controlled by a time control signal generated by the second control signal generator, and a tone generated by the first control signal generator by the time control signal. A waveform forming unit which controls the time lapse of the control signal and controls the characteristic of the musical tone waveform to be formed by the tone control signal whose time lapse is controlled. 6. A first method for generating a loop reproduction waveform by repeating a predetermined loop waveform in a predetermined section in a sound generation period of a sound and forming a waveform of the sound including a plurality of different loop reproduction waveform sections. A step of generating a time control signal that is time-variable and controls the expansion and contraction of the waveform reproduction time, and a section of the loop reproduction waveform generated in the first step. A third step of controlling expansion and contraction of the time length according to the current value of the time control signal. 7. A first step for generating a time-varying tone control signal, a second step for generating a time control signal for controlling the passage of time, and forming a musical tone waveform. Controlling the time lapse of the musical tone waveform to be generated by the time control signal generated in the second step, and controlling the time lapse of the musical tone control signal generated in the first step by the time control signal. Controlling the characteristic of the musical tone waveform to be formed by a controlled musical tone control signal. 8. A machine-readable recording medium containing instructions of a program for forming a waveform to be executed by a computer, the program comprising: a predetermined loop waveform in a predetermined section in a sound generation period. A first step of generating a loop reproduction waveform by including a plurality of different loop reproduction waveform sections to form a waveform of the sound, and controlling the expansion and contraction of the waveform reproduction time. A second step of generating a time control signal that is variable, and a second step of controlling the expansion and contraction of the time length of each section of the loop reproduction waveform generated in the first step in accordance with the current value of the time control signal. 3. A recording medium comprising: 9. A machine-readable recording medium containing instructions of a program for forming a waveform to be executed by a computer, the program comprising: a first program for generating a time-varying musical tone control signal. And a second step of generating a time control signal for controlling the passage of time. A time control signal for forming a musical tone waveform, wherein the time course of the musical tone waveform to be formed is generated in the second step. And controlling the time lapse of the tone control signal generated in the first step by the time control signal, and controlling the characteristic of the tone waveform to be formed by the tone control signal whose time lapse is controlled. 3. A recording medium comprising: