JP3590733B2 - Music signal generator - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention belongs to the technical field of a tone signal generator.
[0002]
[Prior art]
For example, an electronic keyboard instrument represented by an electronic piano includes a plurality of tone generation channels for generating tone signals, channel state storage means for storing the operation state of each tone generation channel, and channel state storage means for detecting key-on. , A pair of tone generation channels is selected, a left tone signal for stereo performance is assigned to one of the selected tone generation channels as an L channel, and a right tone signal for stereo performance is assigned to the other as an R channel. A tone signal generator having a left output system for outputting a left tone signal and a right output system for outputting a right tone signal; a left speaker driven by a tone signal from the left output system; There is a type in which a right speaker is driven by a tone signal from an output system to perform a stereo performance.
[0003]
In order to perform a stereo performance, two tone generation channels (L / R channels) are required for one key operation (key-on). If such L / R channel pairs are prepared by the number of keys, the number of channels does not become insufficient. However, increasing the number of tone generating channels increases the cost. 32 channels), the effective use of a limited number of tone generation channels has been studied.
[0004]
As one of the techniques for effectively utilizing such a tone generation channel, there is a tone generation device disclosed in Japanese Patent Application Laid-Open No. Hei 10-49159. In this tone generating apparatus, when a new key-on is performed when all the tone generating channels are used, two pairs of L / R channels are selected, and one of the tone generating channels forming the pair is truncated. (Rapid decay), and the remaining channels are operated as they are. As a result, the two tone generation channels become free, and they can be used as the L / R channels corresponding to the newly keyed-on keys.
[0005]
[Problems to be solved by the invention]
However, according to the technique disclosed in Japanese Patent Application Laid-Open No. H10-49159, only one of the stereo sounds (one-side channel) remains, and there is a possibility that the volume balance may vary between the left and right. In order to prevent this, it is necessary to control the channel to be truncated such that "the channel was previously the L channel and the R channel is used this time", which complicates the control.
[0006]
In addition, since the sound of one channel is completely eliminated by the truncation process, for example, if the key-on successively occurs with the damper pedal depressed, the total number of channels is stereo-generated, although the overall volume is desired to gradually increase. The volume could not be increased beyond the volume.
[0007]
The present invention provides a tone signal generating apparatus that truncates one of the tone generating channels that are sounding in stereo, and uses the truncated channel for sounding a newly keyed-on key. It is another object of the present invention that the total volume can be increased according to key-on.
[0013]
Means for Solving the Problems and Effects of the Invention
According to a first aspect of the present invention, there is provided a tone signal generating apparatus , comprising: a plurality of tone generating channels for generating tone signals; channel state storage means for storing an operating state of each tone generating channel; Then, a pair of the tone generation channels is selected with reference to the storage contents of the channel state storage means, and one of the selected tone generation channels is assigned as an L channel, and a left tone signal for stereo performance is assigned. A tone signal generating apparatus comprising: allocating means for assigning a right tone signal for the stereo performance using the other as an R channel; a left output system for outputting the left tone signal; and a right output system for outputting the right tone signal. ,
When a new key-on is detected, a pair of the L channel and the R channel corresponding to the key that has been keyed on before is selected by referring to the storage contents of the channel state storage means, and the selected tone generation is selected. The panning value of one tone signal of the channel is asymptotically reduced to 0 (referred to asymptotically 0), and the tone signal of the other tone generating channel is converted to the key scale at the time of key-on which triggered the operation of the tone generating channel. And a recurrence panning means for asymptotically approaching a panning value based on the panning value (referred to as asymptotic key scale).
[0014]
In this tone signal generating apparatus, when a new key-on is detected, the recurrence panning means refers to the contents stored in the channel state storage means and refers to a pair of the L channel and the R channel corresponding to the key that was previously keyed on. A channel is selected, and the panning value of one tone signal of the selected tone generation channel is asymptotically reduced to 0, and the tone signal of the other tone generation channel is converted to a key scale at the time of key-on which triggered the operation of the tone generation channel. Key scale asymptotics to the panning value based on.
[0015]
As a result, a tone generation channel whose panning value is asymptotically set to 0 can be used as a tone generation channel corresponding to a new key-on.
Then, by decreasing the panning value of the tone signal of the remaining tone generating channel to the key scale asymptotically, it is possible to prevent the volume from decreasing due to the asymptotic approach to zero. Can be increased.
In response to the new key-on, two pairs of L and R channels corresponding to the two keys previously keyed on are selected, and zero asymptotic and key-scale asymptotically performed for each channel pair to obtain two empty channels. Once the channels are created, they can be used as tone generation channels for stereo sound corresponding to the new key-on.
[0016]
At this time, as described in claim 2, in the tone signal generating apparatus according to claim 1 , if the speed of the asymptotic zero and the speed of the key scale asymptotically are substantially the same, the volume decrease due to the asymptotic zero is reduced. It can be compensated for by increasing the volume due to the asymptotic key scale, preventing a change in the total volume and not giving a sense of incongruity.
[0017]
Also, as claimed in claim 3, wherein, in the musical tone signal generating apparatus of the mounting according to claim 1, wherein 0 is also the sum of the volume of the asymptotic tone signal to the key scale asymptotic is to tone signal as substantially constant, the same as defined in Claim 2 The effect can be obtained.
[0021]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, an embodiment of the present invention will be described by describing an embodiment of the present invention with reference to the drawings.
[0022]
【Example】
FIG. 1 is a block diagram showing an overall configuration of a keyboard-type electronic musical instrument provided with a tone signal generating device.
The keyboard-type electronic musical instrument 10 includes a keyboard 12 and a panel 14. A player can operate keys on the keyboard 12 and switches on the panel 14.
[0023]
When a key on the keyboard 12 is operated, the key scan circuit 16 detects key depression and key release, that is, key-on and key-off, and sends the detected on / off information to the bus line 17 together with the key number. The key-on / off information and the key number sent to the bus line 17 are taken into the CPU 24 and the tone signal generator 40, and stored in the CPU work RAM 30 under the control of the CPU 24. The CPU work RAM 30 stores an operation state of a tone generation channel described later, and functions as a channel state storage unit.
[0024]
The on / off and position of the mode selection switch, tone color selection switch, and volume controller of the panel 14 are detected by the panel scan 18. The switch information is transmitted from the panel scan 18 to the bus line 17 and stored in the CPU work RAM 30 under the control of the CPU 24.
[0025]
Further, the panel 14 is provided with a panel display 20, which receives an instruction from the CPU 24 and turns on and off an LED for displaying the state of the electronic musical instrument 10 and the like.
Further, a UART 22, which is a serial input / output circuit, is connected to the bus line 17, and receives a MIDI signal.
[0026]
The CPU 24 operates according to the operation program stored in the CPU program ROM 26, and controls the operation of each unit of the electronic musical instrument 10.
The tone color parameter ROM 28 stores a stereo tone color parameter having the structure shown in FIG. 4 and a monaural tone color parameter shown in FIG. As shown in FIG. 4, the stereo timbre parameters are such that the L-side DCO and the R-side DCO are paired for each timbre, and each DCO has a wave start address (Wave Start Address), L-side and R-side panning coefficients, and an attack side. (Attack), decay (Decay), and release (Release). In the case of the present embodiment, the L-side panning coefficient of the L-side DCO is set to 70 for all of the low, middle, and treble, and the R-side panning coefficient is set to 0 for all of the low, middle, and treble. In addition, the L-side panning coefficient is set to 0 for both low, middle, and high sounds, and the R-side panning coefficient is set to 70 for low, middle, and high sounds.
[0027]
Further, as shown in FIG. 5, the monaural tone color parameters include a wave start address, L-side and R-side panning coefficients, attack, decay and release envelope data as an L / R common DCO. In the present embodiment, the panning coefficients of the monaural tone parameters follow the panning curves shown in FIG. 6 (the low-frequency side 80-the high-frequency side 40 curve (L) and the low-frequency side 40-the high-frequency side 80 curve (R)). The L side is set to 80 and the R side is set to 40, the middle tone is set to L side and the R side is set to 70, and the high tone is set to 40 on the L side and 80 on the R side.
[0028]
Returning to FIG. 1, the tone signal generator 40 is connected to the bus line 17. The tone signal generator 40 includes a waveform ROM 42 storing sample waveform data, a sample waveform generator 44 for generating a sample waveform (tone signal) based on the sample waveform data read from the waveform ROM 42, and a sample waveform generator 44. An assignment memory 46 of a RAM as a part, a panning circuit 50 for performing a panning process on the sample waveform generated by the sample waveform generator 44, a sequence accumulation circuit 60 for performing a sequence accumulation process on the panned sample waveform, and the like. It is composed of
[0029]
In the tone signal generator 40 of the present embodiment, the sample waveform generator 44 has 32 tone generation channels for generating a sample waveform, and each channel generates a sample waveform of one sound.
Then, the assignment memory 46 stores key assignment information as shown in FIG. 3 for each channel. That is, the key number, its on / off information, the wave start address, the L-side and R-side panning coefficients, each of the attack, decay and release envelope data, and the loudness data are assignment information for one channel. I can remember.
[0030]
The stored key numbers and their on / off information are transmitted from the key scan circuit 16 to the bus line 17. The wave start address, the L-side and R-side panning coefficients, and the envelope data are obtained from the timbre parameter ROM 28 based on the timbre selection switch on the panel 14. The loudness data is data that the position of the volume controller is detected by the panel scan 18, digitized, and transmitted to the bus line 17. In other words, it can be said that the assignment memory 46 stores data on the key number, timbre, and volume corresponding to the sample waveform generated by each channel.
[0031]
Returning to FIG. 1, the series accumulation circuit 60 has a right output system including DAC 62R, Amp64R, and SP66R as well as a left output system including a digital-analog converter (DAC) 62L, an amplifier (Amp) 64L, and a speaker (SP) 66L. Are connected, and the left and right output systems can convert digital signals output from the sequence accumulation circuit 60 into analog signals, amplify the signals, and output audio.
[0032]
As shown in FIG. 2, the sample waveform generator 44 includes an F-number ROM 70, an F-number accumulator 72, a sample interpolator 74, an envelope generator 76, an assignment memory 46 (not shown in FIG. 2), and the like. ing. Of these, the F number accumulator 72, the sample interpolator 74, and the envelope generator 76 form one set to generate one sample waveform. In this embodiment, 32 sets of these sets (ie, the tone generation channel) Are 32 channels).
[0033]
The key number from the assignment memory 46 is input to the F number ROM 70, and the F number corresponding to the key number is read into the F number accumulator 72. The key on / off information from the assignment memory 46 is also input to the F number accumulator 72. The F number accumulator 72 sends the integer part of the F number to the adder ADD1 and sends the decimal part to the sample interpolator 74. In the adder ADD1, the wave start address from the assignment memory 46 is added to the integer part of the F number, and the data after the addition specifies the address of the waveform ROM 42. The sample interpolator 74 reads the addressed sampled waveform data, and performs an interpolation process on the sampled waveform data using the decimal part of the F number.
[0034]
The sample waveform data output from the sample interpolator 74 is sent to the multiplier MLT1. The multiplier MLT1 receives the envelope data from the envelope generator 76, and multiplies the sample waveform data by the envelope data. The envelope data is based on the attack, decay and release envelope data supplied from the assignment memory 46 to the envelope generator 76. Further, the sample waveform data is multiplied by the loudness data from the assignment memory 46 in the multiplier MLT2.
[0035]
The sample waveform data obtained by multiplying the envelope data and the loudness data in this manner is sent to the panning circuit 50.
The panning circuit 50 is composed of an L-side sequence composed of an L-side panning value interpolation circuit 50L and a multiplier MLT3, and an R-side sequence composed of an R-side panning value interpolation circuit 50R and a multiplier MLT4. The series accumulation circuit 60 also includes an L-side series including an adder ADD3 and a latch 60L, and an R-side series including an adder ADD4 and a latch 60R.
[0036]
The L-side panning value interpolation circuit 50L and the R-side panning value interpolation circuit 50R are instructed by the CPU 24 whether or not interpolation is performed, and if interpolation is performed, send the panning coefficient (pan value) acquired from the assignment memory 46 to the multipliers MLT3 and MLT4. I do. When the panning coefficient is sent to the multipliers MLT3 and MLT4, the panning coefficient is multiplied by the sample waveform data.
[0037]
Further, the sample waveform data is sent to the latches 60L and 60R via the adders ADD3 and ADD4, and the accumulation processing for all channels is performed. As described above, the accumulated data is converted into an analog signal in the left and right output systems, amplified, and output as audio.
[0038]
In the electronic musical instrument 10, as shown in FIG. 7, when the power of the electronic musical instrument 10 is turned on, the CPU 24 performs various initialization processes (S101).
Thereafter, panel processing (S102) for setting the tone color, volume, and the like in accordance with the mode selection switch, tone color selection switch, and on / off and position of the volume controller on the panel 14, and key on / off. The key event (S103), which is a process for executing sound generation and mute, and other processes (S104) are repeatedly executed.
[0039]
As a subroutine included in the key event (S103), a key assignment process closely related to the present invention is performed, and the process will be described with reference to FIG.
In the key assignment process, the CPU 24 first determines whether there is a key-on (S120). If there is a key-on, the CPU 24 searches the CPU work RAM 30 to determine whether there are two empty channels (S121). If there is no empty channel, one pair of stereo sounding pair channels is selected (S122). This selection criterion may be appropriately set. In this embodiment, the oldest paired channel that starts sounding is selected.
[0040]
Subsequently, the CPU 24 instructs the tone signal generator 40 to release one of the selected pair channels (the L channel in the present embodiment) at a high speed (that is, truncate) (S123). Further, the CPU 24 instructs the tone signal generator 40 to change the panning coefficient of the other of the selected pair channels (the R channel in this embodiment) based on the key number, and converts the monaural sound of the R channel into the left and right output systems. (S124). This panning coefficient is determined by, for example, a panning curve (a panning curve of 80-40 and a panning curve of 40-80 in the present embodiment) shown in FIG. 6 (the example of FIG. 6 is a panning curve of a monaural piano sound). , A panning coefficient corresponding to the key number is determined. Although the above-described panning curve is employed in this embodiment, other types of panning curves, for example, full panning curves (L, R) may be used.
[0041]
The fast release is realized by the operation of the envelope generator 76, and the change of the panning is realized by the operation of the panning circuit 50. Therefore, the CPU 24 for instructing monauralization, the envelope generator 76 for realizing the instruction, and the panning circuit 50 function together as monauralizing means and correction panning means.
[0042]
Next, the CPU 24 selects another pair channel of stereo sound (S125), releases one of the selected pair channels (the L channel in this embodiment) at a high speed (S126), and releases the other of the pair channels (this channel). The panning coefficient of the R channel in the embodiment is changed based on the key number, and the monaural sound is output from the left and right output systems (S127).
[0043]
Then, since two empty channels are thus created, new key-on L and R channels are assigned to them (S128). More specifically, data having the contents shown in FIG. 3 is written into an area corresponding to the two empty channels on the assignment memory 46, and the storage of the operating state of the tone generation channel in the CPU work RAM 30 is updated.
[0044]
If there is no key-on (S120: NO), the process returns without performing the processing of S121 and thereafter, and if there is an empty channel (S121: YES), the processing of S122 to S127 is jumped to S128.
In this way, when a new key-on is performed and there is no empty channel to which it is assigned, two pairs of channels are selected, and one channel of each pair is truncated to form two empty channels. And assigning them to a new key-on, enabling stereo sound corresponding to the new key-on. In addition, since the panning coefficient of the channel that has not been truncated at that time is changed and output from both the left and right output systems, the left and right balance can be maintained. Further, the volume of the remaining monaural sound can be prevented from decreasing due to truncation. For example, when key-on is performed successively with the damper pedal depressed, the overall volume can be gradually increased.
( Example of asymptotic processing )
Although the above example employs a technique of rapidly releasing one of the paired channels, as shown in FIG. 9, even if the panning coefficient is set to 0 (S123 ′, S126 ′), two empty channels are created and Can be assigned to a new key-on, and the monaural sound of the remaining channels can prevent the total volume from decreasing. In S123 'and S126', zero asymptote is performed, and in S124 and S127, key scale asymptote is performed (recursive panning means).
[0045]
As described above, the embodiments of the present invention have been described according to the examples. However, it is needless to say that the present invention is not limited to such examples, and can be variously implemented without departing from the gist of the present invention.
[Brief description of the drawings]
FIG. 1 is a block diagram of the overall configuration of an electronic musical instrument according to an embodiment.
FIG. 2 is a block diagram illustrating details of a musical sound signal generating device for an electronic musical instrument according to an embodiment.
FIG. 3 is an explanatory diagram of a structure of an assignment memory of the musical sound signal generator according to the embodiment.
FIG. 4 is an explanatory diagram of a structure of a stereo timbre parameter in a timbre parameter ROM of the electronic musical instrument of the embodiment.
FIG. 5 is an explanatory diagram of a structure of a monaural tone color parameter in a tone color parameter ROM of the electronic musical instrument of the embodiment.
FIG. 6 is a graph showing a panning curve of a monaural piano sound in the electronic musical instrument of the embodiment.
FIG. 7 is a flowchart of a main process executed by a CPU of the electronic musical instrument of the embodiment.
FIG. 8 is a flowchart of a key assignment process executed by a CPU of the electronic musical instrument according to the embodiment.
FIG. 9 is a flowchart of a modified example of the key assignment process.
[Explanation of symbols]
10 electronic musical instrument 24 CPU (allocation means, monaural means, correction panning means)
26 ... CPU program ROM
28 ... Tone parameter ROM
30 ... CPU work RAM (channel state storage means)
40 ... tone signal generator 42 ... waveform ROM
44 sample waveform generator 46 assignment memory 50 panning circuit (monaural means, correction panning means)
60: Series accumulation circuit 62L: Digital-to-analog converter (left output system)
64L… Amplifier (left output system)
66L ... speaker (left output system)
62R: Digital-to-analog converter (right output system)
64R ... Amplifier (right output system)
66R: Speaker (right output system)
70… F number ROM
72 ... F number accumulator 74 ... Sample interpolator 76 ... Envelope generator (monaural unit, correction panning unit)

Claims (3)

A plurality of tone generation channels for generating a tone signal; channel state storage means for storing an operation state of each of the tone generation channels; and when a key-on is detected, the tone is referred to by referring to storage contents of the channel state storage means. Assigning means for selecting a pair of generation channels, assigning one of the selected tone generation channels as an L channel to assign a left tone signal for stereo performance, and assigning the other as an R channel to assign a right tone signal for the stereo performance; And a left output system for outputting the left tone signal, and a right output system for outputting the right tone signal.
When a new key-on is detected, by referring to the stored contents of the channel state storage means, previous to select the pair of the L channel and R channel corresponding to the key-on the provided key, the selected said musical tone-generating The panning value of one tone signal of the channel is asymptotically reduced to 0 (referred to asymptotically 0), and the tone signal of the other tone generating channel is converted to the key scale at the time of key-on which triggered the operation of the tone generating channel. A tone signal generating apparatus comprising: a recurrence panning means for asymptotically approaching a panning value based on the panning value (referred to as key-scale asymptosis) . The tone signal generating device according to claim 1,
The tone signal generating device according to claim 1, wherein the asymptotic speed is substantially the same as the key scale asymptotic speed . The tone signal generating device according to claim 1 ,
A tone signal generating apparatus , wherein the sum of the volume of the tone signal to be asymptotic to 0 and the tone volume of the tone signal to be asymptotic to the key scale is substantially constant .

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