JP5488976B2 - Tone generator and program - Google Patents

Description

  The present invention relates to a sound source device and a program suitable for use in an electronic musical instrument or the like.

  2. Description of the Related Art Conventionally, a sound source device configured using a DSP that is a processor dedicated to digital signal processing is known. In a sound source device using a DSP, the sound source specifications are determined by a program (microcode) stored in the DSP, and therefore, a program that embodies various sound source methods such as a harmonic synthesis method and an FM calculation method can be stored. For example, a musical sound waveform can be generated by a plurality of types of sound source methods even with the same hardware.

  As this type of device, for example, in Patent Document 1, elements that function in common with a plurality of sound source systems are configured by hardware, while elements that function for each sound source system are configured by software in the DSP. In addition, a sound source device is disclosed in which it is possible to form a musical sound with a high degree of freedom by avoiding a reduction in the number of simultaneous sound generation channels while supporting a plurality of sound source methods.

Japanese Patent No. 3858187

  By the way, as described above, the sound source device using the DSP can flexibly cope with various sound source methods, but has a problem of lack of function expandability. The function extensibility here refers to extracting a signal being processed inside the sound source, performing predetermined processing on the extracted signal outside the sound source, and then returning it to the inside of the sound source again. For this reason, delay processing that delays the signal extracted from the inside of the sound source outside the sound source and returns it to the inside of the sound source again, or delay processing that effectively utilizes the path delay associated with signal extraction from the sound source and signal feedback to the sound source. There is a problem that it cannot be realized.

  The present invention has been made in view of such circumstances, and performs delay processing for delaying a signal extracted from the sound source to return it to the sound source again, accompanying signal extraction from the sound source and signal feedback to the sound source. An object of the present invention is to provide a sound source device and a program that can implement a delay process that effectively uses a path delay.

  In order to achieve the above object, according to the first aspect of the present invention, in the sound source device provided with various modules for modifying the musical sound, the extraction means for extracting any output of the various modules and the extraction means A transmitting means for transmitting a signal; a receiving means for receiving a signal that is delayed by a predetermined time in an external device for feedback; and a signal received by the receiving means from any of the various modules. And a path delay acquisition means for acquiring a path delay time from when the extraction means extracts a signal to when the input means inputs a signal.

  The invention according to claim 2 dependent on claim 1 is characterized in that the transmission means transmits an SPDIF signal obtained by encoding the signal extracted by the extraction means by a biphase mark method.

  The invention according to claim 3 that depends on claim 1 is characterized in that the receiving means receives and decodes the SPDIF signal encoded by the external apparatus by the biphase mark method.

  In the invention according to claim 4 subordinate to claim 1, the path delay acquisition means counts the total delay time from the time when the extraction means extracts the signal to the time when the input means inputs the signal. And a path delay calculating means for calculating a path delay time by subtracting the delay time in the external device from the total delay time measured by the time measuring means.

  The invention according to claim 5 is a program that is executed by a sound source device including various modules for modifying musical sounds, and is extracted by the extraction step of extracting any output of the various modules, and the extraction step. A transmission step of transmitting a signal; a reception step of receiving a signal that is delayed by a predetermined time in an external device for feedback; and a signal received by the reception step of any of the various modules And a path delay acquisition step of acquiring a path delay time from signal extraction in the extraction step to signal input in the input step.

  In the present invention, delay processing that delays a signal extracted from the inside of the sound source and returns it to the inside of the sound source again, or implements delay processing that effectively uses the path delay associated with signal extraction from the sound source and signal feedback to the sound source. I can do it.

It is a block diagram which shows the whole structure of the musical tone generator 100 by one Embodiment. It is a figure which shows the format of the SPDIF signal transmitted / received between the signal processing part 16 and the sound source 17. FIG. 3 is a block diagram showing a configuration of a sound source 17. FIG. It is a flowchart which shows the operation | movement of the path | route delay measurement process which CPU10 performs. It is a figure for demonstrating path | route delay time.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
A. Configuration (1) Overall configuration
FIG. 1 is a block diagram showing an overall configuration of a musical sound generating apparatus 100 including a sound source device according to an embodiment of the present invention. In FIG. 1, the CPU 10 controls each part of the apparatus according to a switch event generated by the operation unit 14, and controls the sound source 17 according to performance information generated by the keyboard 13. A characteristic processing operation of the CPU 10 according to the gist of the present invention will be described later.

  The ROM 11 stores various program data loaded into the CPU 10. The various programs referred to here include path delay measurement processing described later. The RAM 12 temporarily stores various register / flag data used for processing of the CPU 10. The keyboard 13 generates performance information such as a key-on / key-off signal, a key number, and velocity according to a performance operation (press / release key operation). The operation unit 14 has various operation switches arranged on the apparatus panel, and generates a switch event corresponding to the operated switch type.

  The display unit 15 displays the operation state and setting state of the apparatus on the screen in accordance with the display control signal supplied from the CPU 10. The signal processing unit 16 includes an SPDIF transceiver, performs delay processing on decoded data obtained by receiving and demodulating the SPDIF signal output from the sound source 17, and encodes the delay data obtained thereby into a SPDIF signal to generate a sound source. 17 to output.

  The tone generator 17 is configured by a well-known waveform memory reading method using a DSP, and forms and outputs musical tone data according to musical tone parameters generated by the CPU 10 based on performance information output from the keyboard 13. Further, as will be described later, the sound source 17 encodes data output from a user-specified module (described later) into an SPDIF signal and supplies it to the signal processing unit 16 and also outputs the SPDIF output from the signal processing unit 16. It also has a function of decoding a signal and inputting it to a user-specified module. The sound system 18 performs D / A conversion on the musical sound data output from the sound source 17 and performs filtering such as removing unnecessary noise from the resulting analog output signal, and then amplifies the signal to generate sound from the speaker. Let

(2) Signal Format of SPDIF Signal Next, the format of the SPDIF signal exchanged between the signal processing unit 16 and the sound source 17 will be described with reference to FIG. FIG. 2 is a diagram illustrating an example of an SPDIF format for transporting 2ch stereo data. The SPDIF signal is divided into block units, and one block is composed of 192 frames # 0 to # 191.

  One frame period corresponds to a sampling period (1 / fs) of data to be transferred. One frame is composed of two subframes (Lch subframe and Rch subframe). One subframe has a 32-bit width of 0SB to 31SB. Among them, a 0-bit to 3SB includes a 4-bit synchronization code Sync Code called a preamble, and an audio sample Audio Sample with a maximum length of 24 bits of 4SB to 27SB. And a 4-bit control signal of 28SB to 31SB. The transfer data of 4SB to 31SB, excluding the synchronization code Sync Code (preamble) in the subframe, is encoded (BMC encoded) by the biphase mark method in which 1 bit is represented by 2 bits.

  The synchronization code Sync Code in the first subframe in frame # 0 is “B” corresponding to the start bit, the synchronization code Sync Code in the next subframe is “W”, and the synchronization code Sync in the first subframe in the next frame # 1 The code is “M”, and thereafter “W” and “M” are alternately repeated until the frame # 191 is reached. The audio sample Audio Sample is usually 20-bit data per sample. However, if 4-bit spare AUX is used, even 24-bit data can be handled.

  The 4-bit control signal is composed of the 28SB validity V, the 29SB user data U, the 30SB channel status C, and the 31SB even parity P. The validity V is a bit indicating validity / invalidity of the audio sample Audio Sample, and is “0 (L)” if valid, and “1 (H)” if invalid. The user data U is user-defined information, and is used, for example, to represent time information such as an elapsed time from the beginning at the time of CD recording or an elapsed time in a song with 192 bits in one block.

  The channel status C is used to indicate an audio sample Audio Sample or an attribute relating to a frame (for example, information indicating a sampling period or copyright). In the even parity P, the parity check value of the transfer data from 4SB to 31SB excluding the synchronization code Sync Code (preamble) in the subframe is set.

(3) Configuration of Sound Source 17 Next, the configuration of the sound source 17 will be described with reference to FIG. The sound source 17 is composed of a known DSP. Therefore, FIG. 3 is a functional block diagram in which each function of the microprogram executed in the DSP is regarded as a hardware image. The sound source 17 shown in this figure includes modules (a waveform generator 30, a filter 31, an envelope generator 32, a mixer 33, and an effect applying unit 34) and an input / output unit (multiplexer 35, SPDIF transmitter 36, SPDIF receiver). Unit 37 and demultiplexer 38).

  The waveform generator 30 is configured by a well-known waveform memory reading method for storing waveform data of various timbres, and reads out waveform data of a specified tone color at a specified pitch according to a musical tone parameter generated by the CPU 10 according to performance information. The filter unit 31 is composed of a well-known DCF (digital control filter), and changes the low-pass characteristic by changing the cutoff frequency of the DCF, for example, according to the filter coefficient supplied from the CPU 10, thereby the waveform generation unit 50. Controls the tone of the waveform data output from.

  The envelope generating unit 32 generates an envelope waveform for volume control according to the ADSR type envelope level / rate supplied from the CPU 10, and multiplies the waveform waveform input from the filter unit 51 for output. The above components 30 to 32 are components corresponding to one sounding channel, and realize simultaneous sounding (polyphonic sounding) from a plurality of sounding channels by operating the structure in a time-sharing manner.

  The mixer unit 33 outputs musical tone data obtained by mixing the waveform data for each tone generation channel output from the envelope generation unit 32 according to the mixing ratio supplied from the CPU 10. The effect applying unit 34 outputs musical sound data in which the effect of the type specified by the effect type supplied from the CPU 10 is applied to the output of the mixer unit 33.

  The multiplexer 35 selects the output of the module specified by the user operation (switch operation) among the modules (the waveform generation unit 30, the filter unit 31, the envelope generation unit 32, the mixer unit 33, and the effect applying unit 34). This is supplied to the SPDIF transmission unit 36. The SPDIF transmission unit 36 encodes the module output extracted via the multiplexer 35 into an SPDIF signal and transmits it to the signal processing unit 16 (see FIG. 1).

  The SPDIF receiving unit 37 decodes and outputs the SPDIF signal transmitted from the signal processing unit 16. The demultiplexer 38 converts the received data output from the SPDIF receiving unit 37 into user operation (switch operation) among the modules (the waveform generation unit 30, the filter unit 31, the envelope generation unit 32, the mixer unit 33, and the effect applying unit 34). ) Input to the module specified by.

  According to such a configuration, for example, the output of the filter unit 31 is extracted and transmitted to the signal processing unit 16, and the signal processing unit 16 performs delay processing that repeats the delay while performing high-frequency attenuation, and outputs the delay processing to the envelope generation unit. In order to input to 32, the signal processing unit 16 and the sound source 17 transmit and receive the SPDIF signal through the path shown in FIG.

  That is, the output of the filter unit 31 is supplied to the SPDIF transmission unit 36 via the multiplexer 35, and the SPDIF signal encoded by the SPDIF transmission unit 36 is transmitted to the signal processing unit 16. The signal processing unit 16 applies low-pass filtering LPF to the received data obtained by decoding the transmitted SPDIF signal, and then adds a delay via a delay memory.

  The delayed data is encoded into an SPDIF signal by the signal processing unit 16 and transmitted to the SPDIF receiving unit 37. Then, the SPDIF receiving unit 37 decodes the received SPDIF signal and supplies it to the demultiplexer 38. The demultiplexer 38 supplies the reception data output from the SPDIF receiver 37 to the envelope generator 32. As a result, it is possible to perform a delay process for delaying the signal extracted from the inside of the sound source and return it to the inside of the sound source again.

B. Operation Next, as the operation of the tone generator 100 having the above-described configuration, a path delay measurement process executed by the CPU 10 will be described with reference to FIGS. As shown in FIG. 5 (a), as shown in FIG. 5 (a), in order to cause the output of the filter unit 31 to be input to the envelope generation unit 32 after being subjected to delay processing that repeats the delay while the signal processing unit 16 attenuates the high frequency band. The signal processing unit 16 and the sound source 17 exchange the SPDIF signal through the path to be transmitted, and it is necessary to measure the path delay time including the processing time required for encoding and decoding at that time in advance.

  Therefore, the CPU 10 executes a path delay measurement process for measuring the path delay time. When the path delay measurement process is executed, the CPU 10 proceeds to step S1 in the flowchart shown in FIG. 4 to clear the timer, and in the subsequent step S2, instructs the sound source 17 to output delay measurement data simultaneously with the start of the timer. To do. Specifically, for example, reading of waveform data for one sample is instructed from the waveform generator 30 of the sound source 17.

  Next, in step S3, the process waits until data is received. This data reception standby means that the waveform data output from the waveform generator 30 of the sound source 17 is “multiplexer 35” → “SPDIF transmitter 36” → “signal processor 16” → “SPDIF reception” shown in FIG. Section 37 ”→“ Demultiplexer 38 ”means a cycle until the sound data of the sound source 17 is output.

  When the data is received, the determination result in step S3 is “YES”, the process proceeds to step S4, and the timer is stopped. Thereafter, the process proceeds to step S5, where the path delay time (delay stage number conversion) is based on the result of subtracting the delay time of the delay memory of the signal processing unit 16 from the total delay time corresponding to the timer count value from the timer start to the timer stop. Is calculated. Thereafter, the process proceeds to step S6, where the calculated path delay time (delayed in the number of delay stages) is registered in a delay time table (not shown) of the RAM 12, and the present process ends. The CPU 10 refers to the path delay time (delayed in the number of delay stages) registered in the delay time table of the RAM 12 and instructs the signal processing unit 16 of the actually required delay stage number.

  In the ideal example with no path delay shown in FIG. 5A, a delay memory having a delay stage number of 44100 steps is required in order to delay the musical sound data of sampling rate 44 KHz by 1 sec in the signal processing unit 16. become. However, there is actually a path delay as shown in FIG. For example, if the path delay time (the number of delay stages) obtained by the above-described path delay measurement process and registered in the delay time table of the RAM 12 is 22050 steps, the CPU 10 stores the path delay time (registered in the delay time table of the RAM 12 ( The number of delay stages is referred to, and the signal processor 16 is instructed by the number of delay stages of 22050 steps, which is offset by that amount. That is, in the signal processing unit 16, if the delay memory has a delay stage number of 22050 steps, it is possible to delay musical sound data with a sampling rate of 44 KHz for 1 sec, so that signal extraction from the sound source and signal feedback to the sound source are possible. It is possible to implement a delay process that effectively uses the accompanying path delay.

  As described above, in this embodiment, among the modules (the waveform generation unit 30, the filter unit 31, the envelope generation unit 32, the mixer unit 33, and the effect imparting unit 34), a module specified by a user operation (switch operation). Is transmitted from the multiplexer 35 that selects the output of the signal, the SPDIF transmission unit 36 that encodes the module output extracted via the multiplexer 35 into the SPDIF signal, and transmits the SPDIF signal to the signal processing unit 16. The SPDIF receiving unit 37 that decodes and outputs the SPDIF signal, and the reception data output from the SPDIF receiving unit 37 are converted into modules (waveform generating unit 30, filter unit 31, envelope generating unit 32, mixer unit 33, and effect applying unit 34). ) Input to the module specified by the user operation (switch operation) Since there is provided a multiplexer 38 can be again returned to the internal sound by performing delay processing for delaying the signal extracted from the internal tone generator.

  Also, a path delay time for making a round of “multiplexer 35” → “SPDIF transmission section 36” → “signal processing section 16” → “SPDIF reception section 37” → “demultiplexer 38” is acquired, and the acquired path delay time is obtained. In order to incorporate this into the number of delay stages necessary for the delay process, it is possible to implement a delay process that effectively utilizes the path delay associated with signal extraction from the sound source and signal feedback to the sound source.

  In the above-described embodiment, an example in which the host CPU 10 that controls the sound source 17 executes the path delay measurement process (see FIG. 4) is described. However, the present invention is not limited to this, and the sound source 10 executes the path delay measurement process. It may be an aspect. In this case, the sound source 10 sends the acquired path delay time (delayed in the number of delay stages) to the CPU 10, and the CPU 10 registers the path delay time (converted in the number of delay stages) received from the sound source 10 in the delay time table of the RAM 12, and With reference to the path delay time (delayed in the number of delay stages) registered in the delay time table, the signal processor 16 is instructed to determine the actually required number of delay stages.

10 CPU
11 ROM
12 RAM
DESCRIPTION OF SYMBOLS 13 Keyboard 14 Operation part 15 Display part 16 Signal processing part 17 Sound source 18 Sound system 30 Waveform generation part 31 Filter part 32 Envelope generation part 33 Mixer part 34 Effect imparting part 35 Multiplexer 36 SPDIF transmission part 37 SPDIF reception part 38 Demultiplexer 100 Musical sound Generator

Claims (5)

In a sound source device equipped with various modules that modify music,
Extraction means for extracting any output of the various modules;
Transmitting means for transmitting the signal extracted by the extracting means;
Receiving means for receiving a signal that the signal transmitted by the transmitting means is delayed by a predetermined time in an external device and returned;
Input means for inputting a signal received by the receiving means to any of the various modules;
A sound source device comprising: a path delay acquisition unit that acquires a path delay time from when the extraction unit extracts a signal to when the input unit inputs a signal.   2. The sound source device according to claim 1, wherein the transmission unit transmits an SPDIF signal obtained by encoding the signal extracted by the extraction unit by a biphase mark method.   2. The sound source device according to claim 1, wherein the receiving unit receives and decodes an SPDIF signal encoded by an external device using a biphase mark method. The route delay acquisition means is
Time measuring means for measuring the total delay time from the time when the extracting means extracts the signal to the time when the input means inputs the signal;
The sound source device according to claim 1, further comprising: a path delay calculating unit that calculates a path delay time by subtracting a delay time in an external device from a total delay time measured by the time measuring unit. A program that is executed by a sound source device equipped with various modules for modifying musical sounds,
An extraction step of extracting any output of the various modules;
A transmission step of transmitting the signal extracted by the extraction step;
A reception step of receiving a signal in which the signal transmitted in the transmission step is delayed by a predetermined time in an external device and returned;
An input step of inputting the signal received in the reception step into any of the various modules;
A program causing a computer to execute a path delay acquisition step of acquiring a path delay time from signal extraction in the extraction step to signal input in the input step.

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