JPH0114598B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a musical tone generating device, and particularly to one using a waveform memory read method.

This type of waveform readout musical tone generation device is used in electronic musical instruments, autorhythm performance devices, etc., but conventionally, waveform data for one period of a desired musical waveform is stored in a waveform memory in advance, and the waveform The waveform data stored in the memory is repeatedly read out at a predetermined speed corresponding to the frequency of the musical tone to be generated (i.e., at a speed corresponding to the pitch assigned to the pressed key). . in this case,
The waveform of the musical tone signal is stored in the waveform memory1.
By simply repeating the periodic waveform as the basic waveform from the start of sound generation (i.e., the rise of the sound) to the end of sound generation (i.e., the fall of the sound), the musical tone signal can be changed over time. It was not possible to change the waveform.

However, the waveform of the musical tone generated when playing a natural musical instrument usually changes from the time the musical tone starts until it ends, and for this reason, the waveform of the musical tone generated by the conventional musical tone generator described above usually changes. The musical tones lacked a natural feel, and it was inevitable that the musical expressions would become monotonous.

In order to solve this problem, it may be possible to store the entire waveform (a waveform approximated to a natural instrument) from the time a musical note starts until it ends in a waveform memory. There is a problem that the storage capacity of

The present invention was made in consideration of the above points, and aims to generate musical tones as rich in naturalness as possible using a waveform memory with as small a storage capacity as possible. In the invention, data of a reference waveform repeatedly included in a musical sound waveform from the start to the end of a musical sound is stored in a reference waveform memory, and a differential waveform representing the difference between the musical sound waveform and the reference waveform is stored. A tone signal is formed by storing the data in the differential waveform memory, repeatedly reading out the waveform data in the reference waveform memory, and synthesizing it with the waveform data in the differential waveform memory.

Embodiments in which the present invention is applied to an electronic musical instrument will be described in detail below with reference to the drawings. In Figure 1, 1
is a reference waveform memory that stores waveform data of a reference waveform. For example, as shown in FIG. 2, a percussive musical sound waveform M such as a piano or a guitar starts to sound at time _t1 until it ends at time _t2 . Reference waveform W ₁ that is repeatedly included between (Figure 3)
Each sample point waveform data is stored with a series of addresses attached for a predetermined period, for example, one period.

Further, 2 is a differential waveform memory that stores waveform data of the differential waveform, and includes waveform data of each sample point of the musical sound waveform M between time t ₁ and time t ₂ in FIG.
Difference waveform data between the reference waveform W ₁ and each sample point waveform data when the reference waveform W ₁ is repeated from time t ₁ to time t ₂ is stored with a series of addresses attached. Here, the address for the differential waveform data is divided into a large number of consecutive blocks, each block having a length corresponding to the length of one period of the address for the reference waveform data, and the first, second, third... blocks. It has a structure in which, for example, the upper bits have a block address part representing the reference waveform data, and the lower bits have the same address part as a series of addresses for reference waveform data. Thus, the first, second, third
...Each time you specify the address part corresponding to a block, you can specify the first, second, third...
The differential waveform data included in the block can be read out in synchronization with the repeated reading of the reference waveform data from the reference waveform memory 1.

In FIG. 1, reference numeral 3 denotes a pitch-corresponding numerical data memory, which receives pressed key number data S1 representing the key number of the pressed key from the keyboard 4 as an address number and receives it as an address number, for example. As the height increases, numerical data F, which increases accordingly, is given to the accumulator 5 as cumulative data. The key-on pulse KONP generated every time a new key is pressed on the keyboard 4 is given to the accumulator 5 as a clear signal, and thus the accumulator 5 is cleared every time a new key is pressed on the keyboard 4. and numerical data F of the size corresponding to the pitch of the relevant key.
is repeatedly accumulated at a predetermined period. In this way, each time the accumulator 5 repeats the accumulation 1, 2, 3... times, the accumulated output qF rises in steps like 1F, 2F, 3F, etc., and this is stored in the reference waveform memory 1.
and sample point address signal to differential waveform memory 2.
Given as AD ₁ .

When the accumulated content reaches the maximum value (for example, all bits are all "1"), the accumulator 5 sends out a carry signal CARY and performs a new accumulation operation again, so that the numerical data F becomes If the pitch of the operated key is high (in other words, if the pitch of the operated key is high), the waveform data stored in memories 1 and 2 is read out at a correspondingly shorter period to correspond to the operated key. Reference waveform data W ₁ and difference waveform data DF of the pitch to be
send out.

The carry signal CARY of the accumulator 5 is given to the block counter 6, and the number of occurrences thereof is counted from the state cleared by the key-on pulse KONP, and the count output S4
The block address signal AD ₂ is sent to the differential waveform memory 2.
given as.

The count output S4 of the block counter 6 is applied to the maximum block detection circuit 7. The maximum block detection circuit 7 detects when the count output S4 exceeds the number Z of the maximum block among the blocks of the differential waveform memory 2, and provides an operation prohibition signal S5 to the accumulator 5 to stop the accumulator 5.
This is done so that no further accumulation is allowed.

In this way, the reference waveform data W ₁ and the differential waveform data DF read from the reference waveform memory 1 and the differential waveform memory 2 after the accumulator 5 starts the accumulation operation and until the accumulation operation is stopped are stored in the adder circuit. The synthesized output is sent to the sound system 9 as a musical tone signal _W2 .
is given and converted into musical tones.

In the above configuration, when a key is pressed on the keyboard 4 at time t ₁ in FIG. 2, a key-on pulse is generated.
The accumulator 5 and block counter 6 are cleared by KONP, and the numerical data F corresponding to the pitch of the pressed key is read from the pitch-corresponding numerical data memory 3. accesses the addresses of the reference waveform memory 1 at a speed corresponding to the size of the numerical data F. When the accumulator 5 repeats the accumulation operation until it reaches its maximum value, one period of reference waveform data W ₁ as shown by the broken line in FIG. 4A is generated at a period corresponding to the pitch of the pressed key. Read out. At the same time, the first block is specified in the differential waveform memory 2 by the count output S4 of the block counter 6, and each address within the first block is specified by the cumulative output qF of the accumulator 5. The first block of differential waveform data _DF1 as shown in FIG. 4B is read out from the differential waveform memory 2.

The synthesis circuit 8 adds the reference waveform data W ₁ and the differential waveform data DF ₁ read in this way to produce a musical tone signal as shown by the symbol W ₂₁ in FIG. 4A.
Send W ₂ to the sound system 9.

Eventually, when the accumulator 5 exceeds the maximum value, the block counter 6 counts up by the carry signal CARY from the accumulator 5, and the count output S4 designates the second block, and the accumulator 5 repeats the accumulation operation again. , reads the memories 1 and 2 and sends the musical tone signal W ₂ to the sound system 9 in the same way as in the above case. Thereafter, in the same manner, each address of the reference waveform memory 1 is read out every time the block counter 6 performs a counting operation, and each address included in a designated block of the differential waveform memory 2 is read _out. As _shown in FIG _. 5B for _the n-th block corresponding to Waveform W _2o different from the first block
A musical tone signal _W2 (FIG. 5A) is obtained.

Eventually, at time _t2 in FIG. 2, the count output S4 of the block counter 6 exceeds the maximum value and the reading of the data stored in the differential waveform memory 2 is completed, so the accumulator 5 is disabled and the sound generation is started. stop.

As described above, according to the configuration shown in FIG. 1, it is possible to obtain a musical tone generating device that can change the waveform as necessary from the start of sound generation to the end of sound generation. In this way, a relatively large amplitude part of the waveform of each period of the musical tone signal _W2 is assigned to the reference waveform _W1 , and a change in the waveform is assigned to the relatively small amplitude difference waveform _DF1 ...DF _o ... By doing so, the overall storage capacity of the waveform memories 1 and 2 can be significantly reduced compared to the case where all the waveform data of the musical tone signal _W2 is stored.
Incidentally, by repeatedly reading out the large amplitude portion of the reference waveform _W1 from the reference waveform memory 1, the memory capacity can be made sufficiently small.

Here, especially the difference waveform for the entire block.
If the waveform of the reference waveform W ₁ is selected so that the amplitude of DF ₁ ...DF _o ... is as small as possible, the overall memory capacity can be further reduced.

FIG. 6 shows another embodiment, showing parts that replace the pitch-corresponding numerical value memory 3 and accumulator 5 in FIG. In FIG. 6, a pressed key number signal S1 sent from the keyboard 4 is received by a note clock generating circuit 15, and a clock pulse S11 of a frequency corresponding to the pitch of the pressed key is generated, and this clock pulse S11 is sent to a counter 16. Give as count input.

The counter 16 receives the key-on pulse KONP as a clear signal and starts counting from an all "0" state, and also receives the detection signal S5 from the maximum block detection circuit 7 as an operation prohibition signal.
As a result, the key-on signal KONP is generated, and after clearing the counter 16, the count output S12 is sent to the reference waveform memory 1 and the differential waveform memory 2 as the address signal _AD1 . Therefore, the counter 16 increases the count (and thus the address) at a speed corresponding to the pitch, so that the same operation and effect as in the case of FIG. 1 can be obtained.

In the above description, a case has been described in which one period's worth of waveform data is stored in the reference waveform memory 1, but instead of this, even if multiple periods' worth of waveform data are stored, the same effect as in the above case can be obtained. can be obtained.

As described above, according to the present invention, by providing a reference waveform memory that is repeatedly read out and a differential waveform memory that is sequentially read out from the time when musical tones are generated, musical tones with a rich natural feel similar to those of a natural musical instrument can be produced. It can be generated by a waveform memory with a much smaller storage capacity.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of a musical tone generating device according to the present invention, FIG. 2 is a signal waveform diagram showing generated musical tone signals, FIG. 3 is a signal waveform diagram showing a reference waveform, and FIGS. Figure 5 shows the time points t ₁ and 2 in Figure 2.
_FIG . 6 is a block diagram showing another embodiment of the present invention. 1...Reference waveform memory, 2...Difference waveform memory, 3...Pitch-corresponding numerical data memory, 4...Keyboard, 5...Accumulator, 6...Block counter, 7...Maximum block detection circuit, 8... ...Synthesis circuit, 15...Note clock generation circuit, 16...
…counter.

Claims (1)

[Scope of Claims] 1 a. A reference waveform memory that stores reference waveform data representing a predetermined reference waveform, and b. The reference waveform data and the musical tone signal to be generated corresponding to each sample point during musical tone generation. a differential waveform memory that stores differential waveform data representing the difference between c. A readout control means for sequentially reading out the waveform memories; and d a musical tone synthesis circuit for synthesizing the waveform data respectively read out from the reference waveform memory and the differential waveform memory to form a musical tone signal. Musical sound generator.