JP6505398B2 - Effect giving device - Google Patents

Description

  The present invention relates to an effect applying device for applying an acoustic effect to musical tone data output from a sound source.

  In electronic musical instruments and the like, processing is performed to apply various sound effects such as chorus and delay to musical tone data output from a sound source using a digital signal processor (DSP) or the like.

  During the processing, the DSP often has an external memory and interpolates and uses sample data stored therein.

  In order to perform this sample interpolation, it is necessary to read out at least two or more consecutive sample data from the external memory.

  However, since the external memory access generally requires more time than the memory access inside the DSP, the number of accesses is limited. When many effects are simultaneously given, it becomes difficult to assign many external memory accesses to one effect, and there is a problem that the target acoustic effect can not be realized.

  The present invention has been made in view of such circumstances, and is an effect imparting device for efficiently achieving a target acoustic effect with high quality even when the number of times of accessing an external memory from a DSP is limited. It is intended to provide

Therefore, the configuration of the present invention is
An effect applying device for applying an acoustic effect to tone data output from a sound source,
External memory,
Data writing means for writing sample data obtained from tone data into one memory area of the external memory;
And data reading means for reading the written sample data from the external memory,
When the data supplied to the data writing means is a true value Xn sampled at a certain time n, when the next time (n + 1) is sampled, the true value Xn immediately before that and the difference value (Xn + 1-Xn) Or a second form representing a true value X n collected at a certain time n.
When the sample interpolation operation is selected and processed, the data supplied from the data reading means is separately read into the operation register into the true value Xn and the difference value (Xn + 1−Xn), and the sample interpolation operation is performed. When the first process is performed without selecting the sample interpolation operation, the data supplied from the data reading means is the sampled true value Xn of the second format into the operation register of this apparatus. The basic feature is to apply an arbitrary sound effect to the above-mentioned tone data by executing the second process to be read.

  According to the above configuration, when storing sample data in the external memory, only the true value is stored in the second format, or the true value and the difference value are stored as one data in the first format. .

  On the other hand, when reading sample data from the external memory, only the true value is read to the operation register by the second process, or the true value and the difference value are read to the operation register by the first process to perform sample interpolation operation Will do.

  As described above, when only the true value is read out to the operation register, since the sample interpolation operation is not performed, it is sufficient to read the data only once, and when the sample interpolation operation is performed, the true value and the difference necessary for the operation Since the values are read at the same time, the data read may be done once.

  Therefore, even when the number of times of accessing the external memory is limited, the target acoustic effect can be easily obtained.

  According to the above configuration of the present invention, when the sample interpolation operation process is performed, the true value and the difference value are read as a set in one sample data, so that the sample interpolation operation process can be easily performed. Even when the number of times of access is limited, the target acoustic effect can be easily obtained, and when the sample interpolation operation processing is not performed, the true value is read with the original data accuracy, so high quality is obtained. It is possible to achieve an excellent effect that processing is possible.

  Hereinafter, embodiments of the present invention will be described together with illustrated examples.

  FIG. 1 is a block diagram schematically showing the configuration of an electronic keyboard instrument in which the effect imparting device of the present invention is used.

  As shown in the figure, the system bus 300 is connected to the keyboard 310, the tone generator 312 and the DSP 10 via the CPU 302, ROM 304, RAM 306 and the operation panel 308 via the panel scan circuit 308a and the keyboard scan circuit 310a. It is done. Input / output of command data to each part and timing control of those inputs / outputs are performed. That is, the system bus 300 controls the respective circuits connected thereto by the CPU 302 described later to function as an electronic keyboard instrument.

  The ROM 304 stores a program memory (not shown) that stores programs used in the CPU 302 and the DSP 10 described later, and necessary various data (for example, coefficients used in the DSP 10).

  The RAM 306 temporarily stores various parameters, data, and the like generated under control of the CPU 302.

  The electronic keyboard instrument is provided with an operation panel 308, a keyboard 310, and the like. The operation panel 308 is provided with a tone color switch for selecting a tone color of a tone to be generated, a switch for effect setting such as delay, and the like. Information set from the operation panel 308 is scanned by the panel scan circuit 308a. The setting value is detected by the above-mentioned and supplied to the CPU 302 via the system bus 300.

  The keyboard 310 is an 88-key keyboard, and each key is provided with a keyboard sensor (not shown) that is a touch sensor. The keyboard sensor detects a player's performance operation on the keyboard 310 and uses various performance information as key press information [information including key press timing (key ON) and key release timing (key OFF) is also included]. Output. Those data are detected by the keyboard scan circuit 310a, a key map KMP is created from these data, and those data are supplied to the CPU 302 via the system bus 300 and sent to the sound source 312 by the CPU 302. Tone data is generated by reading out waveform data from the waveform memory 312a by the tone generator 312.

  The CPU 302 executes the program read from the ROM 304 to control the respective units and input / output processing of data, and controls the entire circuits connected by the system bus 300 as an electronic keyboard instrument. Together with issuing a control command to the tone generator 312, and from the ROM 304, a program for using the DSP 10 for processing the present effect processing device and necessary coefficient data are read out and sent to the DSP 10; The sound effects necessary for the data are thereby added. At this time, the DSP 10 has the external memory 20 under control, performs specific processing based on the tone data input from the tone generator 312, and writes it as sampling data to the external memory 20. Then, processing as described later is performed to read sampling data and output it as musical tone data.

  The musical tone data to which the sound effect is output from the DSP 10 is input to the D / A converter 314 and converted into an analog signal. The analog signal is output from a sound system 316 (such as an amplifier or a speaker).

  FIGS. 2 and 3 show the process of writing tone data input from the sound source 312 into the external memory 20 as sampling data, and the process of reading the sampling data from the external memory 20 and outputting it as tone data. It is explanatory drawing explaining the method of the process by the apparatus of invention.

  As a premise of these figures, tone data output from the sound source 312 is input to the DSP 10, where various effects are applied. At that time, in the DSP 10, various effect programs transmitted from the CPU 302 and coefficients used therein are stored in a program memory (not shown) and coefficient memory (not shown) in the DSP 10, and the above-mentioned musical tones are based on them. Arithmetic processing is performed on the data to generate tone data to which an acoustic effect is applied. Particularly when the reverberation effect is applied, the external memory 20 is connected to the outside of the DSP 10, and using the external memory 20, the DSP 10 performs the following arithmetic processing for writing and reading processing, Such processing results (sampling data) are temporarily stored there, and sampling data that is delayed and output by arithmetic processing is processed one after another, and a reverberation effect is given. Thereafter, it is input to the D / A converter 314 and converted into an analog signal. The analog signal is output from a sound system 316 (such as an amplifier or a speaker).

  As shown in the configuration of this embodiment, sample data acquired from musical tone data sent from the tone generator 312 is based on the first format 12 or the second format based on the various effect programs transmitted from the CPU 302 and the coefficients used therein. Data is written to the external memory 20 in the format 14 and the sample data is read from the external memory 20, and the data is subjected to the first processing or the second processing of these data together with the addition of the sound effect of the tone data. The writing unit 10 a or the data reading unit 10 b is configured in the DSP 10.

Among them, as shown in FIG. 2, when the true value of sample data sampled at time n is X _n , the first format 12 is the true value immediately before that at the next time (n + 1) It is a combination of X _n and its difference value (X _{n +1} −X _n ) so as to be within the size of the original sample data, and is written to one memory area of the external memory 20 by the data writing unit 10 a. Note that, in the figure, a state where sample data is temporarily stored in the write buffer 16 before writing in a predetermined area of the external memory 20 is shown.

The second format 14 is the true value X _{n of} sample data sampled at time n, as shown in the figure, and is written in one memory area of the external memory 20. The write buffer 16 is the same as described above.

On the other hand, when trying to read out the written sample data from the external memory 20 and apply an acoustic effect, as shown in FIG. 3, the data reading unit 10b is paired with the operation register 11 of the present apparatus. Of the true value X _n and the difference value (X _{n + 1} -X _n ) (in the drawing, it is shown that the data is initially read out to the read buffer 18), and the true value X _n and the difference value (X _{n +1} -X _n ) And the sample interpolation calculation is performed.

At the same time, as shown in the figure, the data reading unit 10b reads the true value X _n to the operation register 11 of the present apparatus and sends it as sample data as it is.

  According to the processing flow of FIG. 5 to FIG. 8 described later, writing of sample data and reading of the same data are performed by the data writing unit 10a and the data reading unit 10b. Effects etc. will be given.

In FIG. 4, sample data of amplitudes X _n and X _{n + 1} at times n and (n + 1) are taken by the first processing unit 12, and it is temporarily separated from time n by c. It is explanatory drawing explaining about the process in the case of calculating _| requiring amplitude X _inp by sample interpolation calculation.

The amplitude X _inp is calculated by the sample interpolation calculation process according to the following equation 1.

(1)
X _inp = X _n + (X _{n +1} −X _n ) × c

  FIG. 5 is a flowchart showing the entire processing flow performed when the power of the electronic keyboard instrument is turned on. That is, when the power is turned on, the electronic keyboard instrument is initialized (step S100).

  Then, panel event processing is performed (step S102), and keyboard event processing (step S104) and pedal event processing (step S106) are performed, and then tone generation processing is performed (step S108).

  Subsequently, an acoustic effect application process is performed (step S110), and after the other processes are performed (step S112), the process returns to step S102 and the above process is repeated.

  FIG. 6 is a flowchart showing the process flow of the acoustic effect application process of step S110 of FIG. As shown in the figure, data is read from the external memory 20 (step S200). At that time, either processing 1 or processing 2 is determined in advance for each effect. Then, arithmetic processing for applying an effect according to the effect is performed (step S202).

  Next, a process of writing data to the external memory 20 is performed (step S204). Also in this case, the type 1 or type 2 is determined in advance for each effect. Then, a sound effect output process is performed (step S206).

  7 and 8 show that when sample data is written from the tone data to the external memory 20, it is written as sample data of the first format 12, ie, a set of true value and difference value, or the second format. 14 shows a processing flow for determining whether 14 sample data, that is, only true values are to be written.

As shown in FIG. 7, the data writing process in the first format is processed as follows. That is, new data X _n is collected (step S300). Then, the old data X _n-1 is acquired from the old data buffer (step S302). Thereafter, difference calculation (D _n = X _n −X _n-1 ) is performed (step S304). Then, D and X _n−1 are combined and converted, and one data S _n is obtained according to the following formula 2 (step S 306). The S _n are stored in the data write buffer (step S308). Further, X _n is stored in the old data buffer (step S310).

(2)
S _n = combo (X _n-1 , D)

On the other hand, the data writing process in the second format is performed as shown in FIG. That is, new data X _n is collected (step S400), and X _n is stored in the data write buffer (step S402).

The first process described above is performed as shown in FIG. That is, data is acquired from the read buffer (step S500). Further, the data is separated into a true value R and a difference d (step S502). Sample interpolation is performed according to the following equation 3 with a predetermined coefficient c (step S504). Thereafter, the amplitude X _inp is transmitted as data for effect processing (step S506).

(Number 3)
X _inp = R + d × c

  Further, the second process is performed as shown in FIG. That is, data is acquired from the read buffer (step S600). Then, the acquired data is sent out as effect processing data (step S602).

  According to the configuration of the above embodiment, when storing sample data in the external memory 20, only the true value is stored in the second format 14 or the true value and the difference value are stored as one data in the first format 12 It will

  On the other hand, when reading sample data from the external memory 20, only the true value is read into the calculation register 11 by the data reading unit 10b, or the true value and the difference value are read into the calculation register 11 by the unit 10b. Interpolation will be performed.

  As described above, when the sample interpolation operation process is performed, the true value and the difference value are read as a set in one sample data, so that the sample interpolation operation process can be easily performed by the data reading unit 10b, Even when the memory 20 is accessed, the target acoustic effect can be easily obtained even when the number of times is limited, and when the sample interpolation operation process is not performed, the true value is obtained with the original data accuracy in the data reading unit 10b. Because it is read out, high quality processing is possible.

  The effect imparting device of the present invention is not limited to the above-described illustrated example, and it goes without saying that various changes can be made without departing from the scope of the present invention.

  The effect imparting device of the present invention can be used in various devices as long as it can be configured to add an acoustic effect by a DSP.

It is a block diagram showing an outline of composition of an electronic keyboard instrument with which an effect imparting device of the present invention was used. FIG. 6 is an explanatory view showing a processing mode by the present effect imparting device when writing sample data acquired from tone data to the external memory 20. It is explanatory drawing which shows the processing aspect by this effect provision apparatus at the time of trying to read the written sample data from the external memory 20, and try to provide an acoustic effect. It is process explanatory drawing in the case of calculating | requiring by sample interpolation calculation by the data read-in part 10b. It is a flowchart which shows the whole processing flow performed when the power supply of this electronic keyboard instrument is turned on. It is a flowchart which shows the processing flow of an acoustic effect provision process of FIG.5 S110. 10 is a flowchart showing a processing flow of writing processing in the first format 12 when sample data is written from the musical tone data to the external memory 20. FIG. 18 is a flowchart showing a processing flow of a writing process in a second format 14 when sample data is written from the musical tone data to the external memory 20. FIG. ₁₈ is a flowchart for describing processing in the case where the amplitude X _inp is obtained by sample interpolation operation by the first processing unit 12. FIG. It is a flowchart explaining about the data processing by the 2nd process part 14. FIG.

10 DSP
10a data writing unit 10b data reading unit 11 calculation register 12 first format (sample data of)
14 Second format (sample data of)
16 write buffer 18 read buffer 20 external memory 300 system bus 302 CPU
304 ROM
306 RAM
308 operation panel 308a panel scan circuit 310 keyboard 310a keyboard scan circuit 312 sound source 312a waveform memory 314 D / A converter 316 sound system

Claims (1)

An effect applying device for applying an acoustic effect to tone data output from a sound source,
External memory,
Data writing means for writing sample data obtained from tone data into one memory area of the external memory;
And data reading means for reading the written sample data from the external memory,
When the data supplied to the data writing means is a true value Xn sampled at a certain time n, when the next time (n + 1) is sampled, the true value Xn immediately before that and the difference value (Xn + 1-Xn) Or a second form representing a true value X n collected at a certain time n.
When the sample interpolation operation is selected and processed, the data supplied from the data reading means is separately read into the operation register into the true value Xn and the difference value (Xn + 1−Xn), and the sample interpolation operation is performed. When the first process is performed without selecting the sample interpolation operation, the data supplied from the data reading means is the sampled true value Xn of the second format into the operation register of this apparatus. An effect imparting device characterized by giving an arbitrary sound effect to the musical tone data by executing a second process to be read.

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