JP3705203B2 - Music generation method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a musical sound generation method in which a musical sound can be generated by a general-purpose processing device including an arithmetic processing device.
[0002]
[Prior art]
Conventionally, in a musical tone generator, dedicated tone generator circuits (hardware tone generators) such as a frequency modulation method and a waveform memory method and a microprocessor (CPU) are prepared, and a MIDI (Musical Instrument Digital Interface), keyboard, sequencer, etc. In general, the CPU generates the musical sound by controlling the hardware sound source in accordance with the performance information from the CPU. For this reason, the musical sound generator becomes a dedicated device for generating musical sounds, and it is necessary to prepare a dedicated musical sound generator when generating musical sounds.
[0003]
In order to solve this, recently, a musical sound generation method has been proposed in which the operation of the hardware sound source is replaced with sound source processing (software sound source) by a computer program, and the performance processing and sound source processing are executed by the CPU. (Japanese Patent Application No. 7-144159). Here, the performance process is a process for creating control information for controlling a musical tone to be generated based on performance information such as input MIDI, and the sound source process is a control created in the performance process. This is a process for generating musical tone waveform data based on the information.
[0004]
As a specific example, the CPU normally performs performance processing such as key depression detection, and interrupts sound source processing for each sampling cycle (conversion timing of the digital / analog converter) for the performance processing. There has also been proposed a method of executing and generating waveform data for one sample of musical sounds of a plurality of channels and then returning to performance processing again.
In such a musical tone generation method, a musical tone can be generated by using a DA conversion chip in addition to the CPU and software without using a dedicated musical tone generator.
[0005]
[Problems to be solved by the invention]
In the above-described conventional method for generating a musical tone equipped with a software sound source, the software sound source is used exclusively, and the generated performance information is fixedly supplied to the software sound source. It was.
By the way, as described above, the software sound source can be executed by a general-purpose computer such as a personal computer. Generally, a personal computer or the like may be equipped with a hardware sound source using an expansion board, but if a musical sound generation method equipped with a software sound source is executed on a general-purpose computer equipped with a hardware sound source using an expansion board, the expansion There was a problem that the hardware sound source by the board could not be used.
[0006]
Therefore, an object of the present invention is to provide a musical sound generation method that can use a hardware sound source even if it includes a software sound source.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, a musical sound generating method according to the present invention is a musical sound generating method executed in an arithmetic unit, wherein a step of sequentially supplying performance information and at least one of a hardware sound source and a software sound source are specified. And an input step for causing the hardware sound source and / or the software sound source to be input according to the designation, wherein the input step causes the computing device to input the hardware sound source. Is not connected, the performance information is input to the software sound source, the software sound source, Every predetermined period Multiple of Generating musical sound waveform samples for sampling period in a batch Perform waveform generation calculation It is supposed to be.
In the input step, when the software sound source is designated, performance information is input to the software sound source at an earlier timing than when the hardware sound source is designated. It is.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows the configuration of an embodiment of a musical sound generating apparatus capable of executing the musical sound generating method of the present invention.
In this figure, 1 is a microprocessor (CPU) that performs various controls such as generation of musical sound waveform samples by executing an application program and the like, 2 is a read only memory (ROM) in which preset tone color data and the like are stored, 3 A random access memory (RAM) having storage areas such as a work memory area, a tone color data area, an input buffer area, a channel register area, and an output buffer area of the CPU 1, 4 indicates the time, and the timing of timer interrupt processing to the CPU 1 The instructing timer 5 is a MIDI interface that receives a MIDI event and outputs a generated MIDI event, and an external sound source 6 can be connected to the MIDI interface as indicated by a dotted line.
[0009]
7 is a so-called personal computer keyboard having keys such as letters, kana, numbers, symbols, etc. 8 is a display (monitor) for the user to interact with the musical sound generating device, 9 is installed with various application programs and musical sounds. A hard disk drive (HDD) 10 stores musical sound waveform data used for generating waveform samples, and 10 stores data of musical sound waveform samples stored in an area designated by the CPU 1 in the RAM 3 via the CPU 1. A direct memory access (DMA) circuit that delivers data directly to the digital-to-analog converter (DAC) 11 at a constant sampling period (for example, 48 kHz). To digital-to-analog converter (DAC) 12 is a kind of expansion board, a sound card hardware sound source described above is mounted. 13 is a mixer circuit that mixes the tone signal output from the DAC 11 and the tone signal output from the sound card 12, and 14 is a sound that emits the tone signal converted to an analog signal output from the mixer circuit 13. System.
The above configuration is the same as that of a general-purpose computer such as a personal computer or a workstation, and the musical tone generation method of the present invention can be implemented on them.
[0010]
FIG. 2 shows an example of the software module configuration of this musical tone generator. In this figure, only parts related to the musical sound generating method of the present invention are shown for the sake of simplicity.
As shown in this figure, application software is located in the highest layer, and 21 is a program that requests reproduction of MIDI such as a MIDI sequencer, game software, or karaoke software (hereinafter simply referred to as “sequencer program”). It is. The next layer is a system software group, where a software sound source 23 is located, and the software sound source 23 includes a (software) sound source MIDI driver and a sound source unit. Reference numeral 25 is a program group for realizing a so-called multimedia function such as a waveform (WAVE) input / output driver, 26 is a codec driver for a codec circuit 16 described later, and 28 is a sound card driver for the sound card 12. . The codec circuit 16 includes an A / D converter and a D / A converter for inputting and outputting waveform sample data. The D / A converter is the DAC 11 in FIG.
[0011]
Reference numeral 22 denotes a software sound source MIDI output API (application programming interface) for interfacing the application program with the software sound source 23, and reference numeral 24 denotes a waveform (WAVE) input in the application program and the program group 25. A waveform output API 27 for interfacing with the output driver is a MIDI output API 27 for interfacing application software such as the sequencer program 21 with the sound card driver 28 and the external sound source 6. Each program can use various services provided by the system program using these APIs.
Although not shown, the system software hierarchy naturally includes a group of programs such as a device driver group and a memory management, file system, and user interface included in a general general-purpose OS.
[0012]
In such a configuration, a MIDI event is output from the sequencer program 21 as performance information. In the present invention, as the output destination of this performance information, one or both of the soft sound source MIDI output API 22 and the MIDI output API 27 can be selected as shown in the figure. This is realized by designating an API that should receive the MIDI event and sending the MIDI event from the sequencer program 21. However, the hardware sound source cannot be selected when the hardware sound source is not attached.
[0013]
When the software sound source 23 is selected as the output destination of the performance information from the sequencer program 21 and a MIDI event is output to the software sound source MIDI output API 22, the software sound source 23 converts the received MIDI message into waveform (WAVE) output data. And the waveform output API 24 is called. The waveform data corresponding to the generated musical sound is output to the codec circuit 16 via the codec driver 26, converted into an analog signal by the DAC 11 as described above, and is generated by the sound system 14.
[0014]
On the other hand, when a hardware sound source mounted on the sound card 12 is selected as an output destination of performance information from the sequencer program 21, and a MIDI event is output to the MIDI output API 27, the MIDI event is sent to the sound card driver 28. To a hardware sound source in the sound card 12 and corresponding musical sound is generated based on a musical sound generation method specific to the hardware sound source.
Further, when an external sound source 6 connected to the outside is selected as an output destination of performance information, a MIDI event is output to the MIDI output API 27, and the external sound source is connected via the external MIDI driver in the program group 25 and the MIDI interface 5. 6 is output. Thereby, the corresponding musical sound is generated from the external sound source 6.
[0015]
FIG. 3 is a diagram for explaining a musical sound generation process performed using the software sound source 23. In this figure, what is described as performance input is a MIDI event output from the sequencer program 21 described above, and is transmitted at a timing according to the score, for example, at times ta, tb, tc, and td. When this MIDI event is received, an interrupt with the highest priority is generated, and in the MIDI reception interrupt processing, the MIDI event is stored in the input buffer together with the reception time data. Thus, the MIDI processing is performed in the software sound source 23, and the sound generation control signal corresponding to each MIDI event is written in the sound source register of the corresponding sound generation channel.
[0016]
The middle part of the figure shows the timing of the waveform generation calculation executed by the sound source processing unit of the software sound source 23, which is activated at a constant cycle as indicated by calculation times t0, t1, t2, and t3. . This period is called a frame period, which is a period corresponding to the number of waveform samples that can be stored in one output buffer. In each frame period, the waveform generation calculation of each sound channel is executed using the sound generation control signal stored in the sound source register of each sound channel by the MIDI processing according to the MIDI event received in the previous frame period Is done. The waveform data generated in this way is added to the output buffer, and as shown in the lower part of FIG. 3, the DMA circuit 10 sequentially reads out each sampling period in the next frame period and is reproduced by the DAC 11. The As a result, pronunciation is performed without interruption.
[0017]
(Software sound source processing)
FIG. 4 is a diagram showing a flowchart of processing executed by the software sound source 23. When the software sound source 23 is activated, first, in step S10, initialization such as clearing of various registers is performed. Subsequently, in step S11, a screen preparation process such as displaying an icon for displaying that the software sound source is activated to the user is performed. Next, the process proceeds to step S12, where it is checked whether or not there is an activation factor. As activation factors, (1) there is an unprocessed event in the input buffer (this occurs when a MIDI event is received), and (2) a waveform calculation request is generated (as the calculation time). There are four factors: (3) a processing request other than MIDI processing such as input of a sound source operation control command from the keyboard or panel is generated, and (4) an end request is generated. Is present.
[0018]
In step S13, it is determined whether there is an activation factor. If NO, the process returns to step S12 and waits for the activation factor to occur. If the decision result in the step S13 is YES and it is detected that the activation factor is generated, the process proceeds to a step S14 to determine which of the (1) to (4) is the activation factor. .
[0019]
(MIDI processing)
As a result of this determination, (1) when there is an unprocessed event in the input buffer, the process proceeds to step S15 and MIDI processing is performed. In this MIDI processing, processing for converting a MIDI event written in the input buffer into a control parameter to be passed to a sound source (sound generation channel) corresponding to the MIDI event is performed. After the MIDI process in step S15 is completed, a reception display process in step S16 is performed, and the fact that the MIDI has been received is displayed on the screen. Then, the process returns to step S12 and waits for the generation of the activation factor.
[0020]
An example of the MIDI processing in step S15 is shown in FIGS. FIG. 5A is a flowchart of the MIDI processing executed when the MIDI event stored in the input buffer is a note-on event. When the unprocessed event is a note-on event, first, in step S31, the note number is taken as NN, the velocity is set as VEL, and the tone data for each part is taken as t, respectively. Is generated in the TM register. Next, the sound generation assignment process of the note number NN taken into the register in step S32 is performed, and the assigned channel (ch) number is taken into the register as i.
[0021]
Subsequently, in step S33, the timbre data TP (t) corresponding to t is processed according to the note number NN and the velocity VEL. In step S34, the processed tone color data, note-on and generation time data TM are written to the i-channel sound source register, and the note-on event process is terminated.
[0022]
FIG. 5B is a flowchart of processing when the unprocessed event is a note-off event.
When the note-off process is started, in step S41, the note number of the note-off event in the input buffer is taken as NN, and the tone data for each part is taken as t, respectively. Is generated in the register as TM. Next, in step S42, the sound channel (ch) sounded with the note number NN is searched, and the number of the sound sound channel found is taken into the register as i. Next, in step S43, note-off and occurrence time TM are written in the sound source register of ich, and the note-off event process is terminated.
[0023]
(Sound source processing)
In step S14, when the activation factor is (2) generation of a waveform calculation request, the sound source process of step S17 is executed. This process is a process for performing a waveform generation calculation, and the waveform generation calculation is performed based on the musical tone control data stored in the tone generator register corresponding to each channel (ch) in the MIDI process in step S15. After the sound source process in step S17 is completed, for example, the CPU load amount required for the sound source process is displayed in step S18. Thereafter, the process returns to step S12 and enters a waiting state.
[0024]
In the sound source processing in step S17, first, the LFO, filter G, and volume EG waveforms are calculated for the first tone generation channel (ch) in the calculation order, and the LFO waveform and FEG waveform necessary for calculation within a predetermined time range. A sample of the AEG waveform is generated. The LFO waveform is added to the F number, FEG waveform, and AEG waveform to modulate each data. For the sound generation channel designated as the channel to be muted, a dump AEG waveform that rapidly attenuates within the above range is calculated and generated as the volume EG.
Next, the F number is repeatedly added with the previous read address as an initial value to generate a read address for each sample within the time range, and a waveform sample is obtained from the waveform storage area in the timbre data based on the integer part of the read address. At the same time as reading, interpolation is performed between the waveform samples read based on the decimal part of the read address, and all interpolation samples within the time range are calculated.
[0025]
Furthermore, timbre filter processing is performed on the interpolation sample within the time range, timbre control is performed based on the FEG waveform, amplitude control processing is performed on the sample within the time range that has been filtered, Based on the AEG and the volume data, amplitude control of the musical sound waveform samples is performed, and an accumulative writing process is performed in which the musical sound waveform samples of the time range subjected to the amplitude control processing are respectively added to the corresponding samples in the output buffer. Is done.
In this way, the waveform sample generation processing of each sound generation channel is performed until the calculation of all sound generation channels is completed, and the generated samples for the predetermined time range are sequentially added to the corresponding samples in the output buffer.
[0026]
Note that the MIDI processing in step S15 and the sound source processing in step S17 are described in detail in Japanese Patent Application No. 7-144159, so refer to this publication if necessary.
[0027]
(Other processing)
If it is determined in step S14 that (3) it is another processing request, the process proceeds to step S19, and if the corresponding processing, for example, this processing request is a timbre setting / changing process, it is set. After performing processing such as setting a timbre number, the process proceeds to step S20 to display the set timbre number, and then returns to step S12 to enter a waiting state.
Further, if it is determined in step S14 that (4) it is an end request, end processing is performed in step S21, related screen information is erased in step S22, and this software sound source processing is ended.
[0028]
(MIDI reception interrupt processing)
Next, a flowchart of the MIDI reception interrupt process executed by the CPU 1 is shown in FIG. This process is started by an interrupt generated when the software tone generator MIDI output API 22 is called and performance information (MIDI event) is received from the sequencer program 21 or the like. The priority of this interrupt is the highest, and this MIDI reception interrupt process is a process that is performed in preference to other processes such as the sequencer program 21 and the software tone generator 23. When this MIDI reception interrupt process is started, the MIDI event data received in step S51 is fetched. In step S52, the received data is written in the input buffer in combination with the time data at the time of reception. Return to the process when an interrupt occurs. As a result, the received MIDI data is sequentially written to the input buffer together with the reception time.
[0029]
(Sequencer program)
FIG. 7 shows a flowchart of processing in the sequencer program 21. When the sequencer program 21 is activated, first, initial settings such as clearing of various registers are performed in step S61, and then an icon or the like indicating that the program is activated is displayed in step S62. Screen preparation processing is performed. Then, the process proceeds to step S63, where it is checked whether or not an activation factor has occurred. If it is determined in step S64 that an activation factor has occurred, the process proceeds to step S65. In step S65, it is determined what the generated activation factor is, and the process branches to a corresponding step according to the activation factor. If no activation factor has occurred, the process returns to step S63 to wait for the activation factor to occur.
[0030]
The sequencer program activation factors include (1) generation of a start / stop request, (2) generation of an interrupt from the tempo timer, (3) designation of an output destination sound source, change of tempo, change of part balance, Other requests such as editing or automatic performance recording processing are generated, and (4) a program termination request is generated.
[0031]
First, when the determination result of the factor in step S65 is (3) generation of another request, processing corresponding to each request as described above is performed in step S90, and then a corresponding display is displayed in step S91. Done. Then, the process returns to step S63 and waits.
[0032]
(Output destination specification processing)
The performance information output destination designation process is one of the processes processed in step S90. For example, when the player clicks a switch for switching the output sound source displayed on the screen of the display 8 with the mouse in step S62, the designation of the output sound source is detected as an activation factor in step S65. This output destination designation process is activated. The output destination designation process will be described with reference to FIG.
[0033]
FIG. 8A is a flowchart showing a first form of output destination designation processing. In this embodiment, output destination sound sources of all performance information output from the sequencer program 21 are selected at once.
When the process is started, first, in step S900, output sound source designation data designated by the user is stored in the TGS register. In this embodiment, every time the performer clicks the output sound source designation switch displayed on the screen, the four selection states shown in FIG. 8B, that is, (A) do not output to any sound source. (B) Output to software sound source, (c) Output to hardware sound source, (d) Output to both software sound source and hardware sound source are changed cyclically, The value of the modulo 4 of the number of clicks is stored in the TGS register as output sound source designation data.
[0034]
In step S901, it is determined whether the sound source designated by the contents of the TGS register is the software sound source 23 or the hardware sound source 12. In step S902, a logo indicating the standard of the selected output sound source is displayed on the display screen. An example of this display is shown in FIG. This logo display allows the performer to know the standard of the sound source used.
[0035]
FIG. 8D shows a flowchart of the second form of the output destination designation process. In this form, a sound source to be output for each performance part can be selected.
When the process is started, first, in step S910, the input part designation data is fetched as a variable p. Next, in step S911, the output sound source designation data of the designated part p is stored in the TGSp register. In step S912, the setting state of each part and the corresponding output sound source is displayed. Thus, by providing a register for storing output sound source designation data for each part, it becomes possible to select a sound source to be output for each part.
[0036]
For example, for a certain piece of music, the drum part is a software sound source (GM), the base part is a software sound source (XG), the guitar part is a hardware sound source (XG), and the electric piano part is a hardware sound source (FM sound source). Can be specified.
The correspondence between each part and the sound source to be output may be set by the performer, or if the sound data of each part is provided in the hardware sound source, the hardware sound source is used. Otherwise, a software sound source may be used.
[0037]
In addition, when a hardware sound source or a software sound source is used, it is automatically determined whether the sound card 12 or the external sound source 6 is attached to the general-purpose computer. Can automatically select a hardware sound source and select a software sound source when not installed.
Thereby, it is not necessary to change the setting by attaching and detaching the hardware sound source.
[0038]
(Start / stop processing)
As a result of the determination in step S65, if the activation factor is (1) generation of a start / stop request, start / stop processing is performed in step 70, and after the start / stop state is displayed in step S71. Then, the process returns to step S63 and waits for an activation factor to be generated.
The start / stop process in step S70 will be described with reference to FIG. This start / stop request is made by a player's operation. For example, a start / stop request is input by clicking a predetermined field on the screen. When this start / stop request is input, whether or not the current state is the stop state is determined in step S700 based on the state of the RUN flag. The RUN flag is a flag that is set to “1” when in the performance state, and when the determination result is NO, the current state is in the performance state. Therefore, the process proceeds to step S701, and the RUN flag is reset. In step S702, the tempo timer is stopped, and in step S703, post-processing of automatic performance is performed to stop the performance.
[0039]
On the other hand, if it is currently stopped and the determination result in step S700 is YES, the process proceeds to step S704, where the RUN flag is set, and preparation for automatic performance is made in step S705. In preparation for this automatic performance, various processes such as transfer of designated song data from the hard disk device 9 or the like to the RAM 3, setting of the start address to the read pointer, preparation of the first event, and setting of volume for each part, etc. Is done. Subsequently, a tempo timer is set in step S706, and the tempo timer is started in step S707 to start playing.
[0040]
(Event playback processing)
If the determination result of the activation factor in step S65 is (2) tempo timer interrupt is present, event reproduction processing is performed in step S80, and then the event is displayed in step S81. Then, the process returns to step S63 to enter a waiting state for an activation factor.
The event reproduction process in step S80 will be described with reference to FIG. The tempo timer interrupt is an interrupt periodically generated to determine the performance tempo, and the performance time is determined by this interrupt. When this tempo timer interruption occurs, the time is counted in step S800. Then, in step S801, it is determined whether or not the count result exceeds the event time at which the event should be reproduced. If not, the event reproduction process S80 is terminated.
[0041]
On the other hand, if the decision result in the step S801 is YES, the process advances to a step S802 to reproduce the event, that is, take out the event from the RAM 3. In step S803, the extracted event (reproduction event) is output. This reproduction event output process is a mediation routine corresponding to the contents of the TGS register set in the output destination designation process, that is, when outputting the reproduction event to the software sound source 23, the software sound source MIDI output API 22, the hardware sound source 12 is a process of outputting to the MIDI output API 27. As a result, the MIDI event is output to the designated sound source. In step S804, the reproduction time of the next event is calculated by adding the duration data of the retrieved reproduction event and the event time, and the event reproduction processing routine is terminated. Note that the processing in step S803 corresponds to the form shown in FIG. 8A in which the output sound source is collectively designated for the entire performance information.
[0042]
As described above, when an event is output by the reproduction event output process in S803, the MIDI reception interrupt is generated and the MIDI event is stored in the input buffer. Then, after the interruption process is completed, control returns to the event reproduction process routine described above, and the next event time calculation process in step S804 is executed.
[0043]
FIGS. 10A and 10B show a modification of the reproduction event output processing step S803. FIG. 10 (a) corresponds to the form of designating the output destination sound source for each performance part shown in FIG. 8 (b). First, in step S810, the part of the reproduction event is detected and taken as a variable p. In step S811, the contents of the register TGSp are referenced, and the reproduction event is output to a mediation routine (API) corresponding to the contents. Thereby, performance information is output to the sound source designated for each part.
[0044]
FIG. 10B shows that performance information is preferentially output to a hardware sound source, and when the number of channels to be sounded exceeds the number of soundable channels of the hardware sound source, the performance information corresponding to that number is output. This is a form in which sound is generated by a software sound source. In this modified example, first, in step S820, it is determined whether or not the reproduction event extracted in step S802 (FIG. 9B) is a note-on event. If it is not a note-on event, the process proceeds to step S821, where this event is output to a sound source that has previously received a note-on corresponding to the event, and the process ends.
[0045]
On the other hand, if the playback event is a note-on event and the determination result in step S820 is YES, the current sound generation number of the hardware sound source is detected in step S822, and the sound source of the hardware sound source can be generated by the playback event in step S823. Determine whether the number of channels is exceeded. If the determination result is NO, the process proceeds to step S824, and this reproduction event is output to the hardware sound source. If the decision result in the step S823 becomes YES, the process proceeds to a step S825 to output this reproduction event to the software sound source 23. As a result, it is possible to generate a sound that exceeds the number of channels (for example, 32 ch) that can be generated by the hardware sound source using the software sound source.
[0046]
If the activation result is (4) termination request as a result of the determination in step S65, the process proceeds to step S100 to perform termination processing. finish.
[0047]
When performance information is output to a hardware sound source mounted on the sound card 12 or an external sound source 6 connected to the outside, sound generation processing is executed on the hardware sound source by a well-known method.
However, when the performance information is output to both the software sound source and the hardware sound source, as described above, a delay of a predetermined time occurs in the generation of the musical sound by the software sound source. It is necessary to perform processing such as delaying the output of performance information to the hardware sound source by the time.
[0048]
In addition, when the sequencer program 21 is software in which musical tone reproduction and other processing such as image display are performed in synchronization, it may be necessary to consider this delay time.
For example, in the case of karaoke software, it is common to display lyrics along with the performance of a song. A process of gradually changing the color of the lyrics according to the progress of the accompaniment (wipe process) and a process of replacing the displayed lyrics are performed. By the way, such lyrics display processing needs to be synchronized with the accompaniment sound. Therefore, when the hardware sound source and the software sound source can be selected by the karaoke software as in the present invention, it is necessary to change the display timing according to which sound source is selected. That is, when a software sound source is selected, display processing is performed at a later timing than when a hardware sound source is selected. Further, instead of taking the timing when displaying lyrics, the timing of performance information supplied to each sound source may be adjusted. That is, when a software sound source is selected, performance information is output to the sound source at an earlier timing than when a hardware sound source is selected.
Note that the present invention can be applied in exactly the same manner when performance information input from an external sequencer or the like is passed to a sound source via a MIDI interface.
[0049]
【The invention's effect】
According to the present invention, it is possible to select a software sound source and a hardware sound source and output performance information, and when a hardware sound source is not installed, the software sound source is automatically selected. It is possible to eliminate the need to change the setting of whether to use the hardware sound source or the software sound source when the wear sound source is attached or detached.
[Brief description of the drawings]
FIG. 1 is an example of a musical sound generating apparatus capable of executing a musical sound generating method of the present invention.
FIG. 2 is a software module configuration of the musical sound generating device of FIG. 1;
FIG. 3 is a diagram for explaining a musical sound generation process performed using a software sound source;
FIG. 4 is a flowchart of software sound source processing.
FIG. 5 is a flowchart of MIDI processing.
FIG. 6 is a flowchart of a MIDI reception interrupt process.
FIG. 7 is a flowchart of processing performed by a sequencer.
FIG. 8 is a diagram for explaining an output destination designation routine.
FIG. 9 is a flowchart of start / stop processing and event reproduction processing;
FIG. 10 is a flowchart of playback event output processing.
[Explanation of symbols]
1 CPU, 2 ROM, 3 RAM, 4 timer, 5 MIDI interface, 6 external sound source, 7 keyboard, 8 display, 9 hard disk drive, 10 DMA circuit, 11 D / A converter (DAC), 12 sound card, 13 mixer , 14 Sound system, 15 Bus, 16 Codec, 21 Sequencer program, 22, 24, 27 API, 23 Software sound source, 25 Program group, 26 Codec driver, 28 Sound card driver

Claims (2)

A musical sound generation method executed in an arithmetic device,
Sequentially supplying performance information;
Designating at least one of a hardware sound source and a software sound source;
An input step of causing the hardware sound source and / or the software sound source to be input in accordance with the specification, the supplied performance information,
In the input step, when the hardware sound source is not connected to the arithmetic device, the performance information is input to the software sound source,
The method according to claim 1, wherein the software sound source performs a waveform generation calculation for generating a plurality of musical sound waveform samples for a plurality of sampling periods at a predetermined period .   In the input step, when the software sound source is designated, performance information is input to the software sound source at an earlier timing than when the hardware sound source is designated. The method for generating musical sounds according to claim 1.

Images