JP2000022644A - Sample data transfer system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily process sample data sampled at various frequencies by a device at the transfer destination by complementing sample data expressing a prescribed amplitude value at the interval of two samples, transforming these data to new sample data at the apparent frequency of a prescribed multiple in the case of transferring sample data at a prescribed frequency. SOLUTION: Concerning the sample data transfer system, a waveform reproducing device 10 as a device at the transfer source and a digital speaker device 30 as the device at the transfer destination are connected by a communication path 50, regenerative data are transferred from the waveform reproducing device 10 through the communication path 50 to the device 30, and the device 30 receives the transferred regenerative data and discharges sounds based on these data. A regenerative data memory 14 stores plural pieces of regenerative data and these regenerative data are composed of series of sample data expressing the waveforms of sounds and sampling frequency information expressing the sampling frequencies of these series of sample data.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a sample data transfer system, and more particularly, to a sample data transfer system capable of transferring sample data sampled at different sampling frequencies.

[0002]

2. Description of the Related Art Conventionally, sample data sampled at a predetermined sampling frequency has been transferred from one device (a source device) to another device (a destination device) by communication.

In general, monaural 16-bit (bit) data is transferred according to the data format shown in FIG. 1 regardless of the sampling frequency.

Here, if the sampling frequency is assumed to be 44 k
In the case of the sample data sampled in Hz, the data amount per unit time is “44 Kbytes × 2 / sec (second)” in the format shown in FIG.
On the other hand, if the sample data is sampled at a sampling frequency of 22 kHz, the data amount per unit time is “22 Kb” in the format shown in FIG.
yte × 2 / sec (second) ”, and the data is transferred from the transfer source device to the transfer destination device at a speed corresponding to each sampling frequency, and is processed in the transfer destination device.

FIG. 2 shows a personal computer (PC) 200 as a transfer source device to an external digital / analog conversion device (external D / A device) as a transfer destination device.
FIG. 1 shows the configuration of a conventional sample data transfer system when transferring sample data to 220.

In the conventional sample data transfer system shown in FIG. 2, digital audio data reproduced by an audio reproduction application program on a PC 200 is transmitted from a communication IC 204 through a driver (Driver) 202 to an external D. / A device 220 and received by the communication IC 222 of the external D / A device 220.

[0007] The digital audio data received by the communication IC 222 of the external D / A device 220 is filtered in a digital signal processor (DSP) 224 and further processed by a digital / analog converter (D / A).
/ A) Digital / analog conversion (D / A conversion) at 226
And converted to analog audio data.

[0008] The analog audio data obtained by the D / A conversion by the D / A 226 is supplied to the switch 23 of the analog filter switching mechanism 228.
The signal is output to the outside through an analog filter (22 kHz analog filter 232 or 11 kHz analog filter 234) switched by Oa and 230 b (the 22 kHz analog filter 232 and the 11 kHz analog filter 23).
4 will be described later. ) Where external D / A
When the data format shown in FIG. 1 is used in the device 220, it is necessary to provide a clock switching mechanism 236 for appropriately switching the operation clock according to the sampling frequency. That is,
When the sampling frequency of the digital audio data transmitted from the PC 200 is 44 kHz, the clock generator for generating the operation clock of the external D / A device 220 is controlled by the switch 238 of the clock switching mechanism 236 to the clock for 44 kHz. Switch to generator 240, digital audio transmitted from PC 200
If the data sampling frequency is 22 kHz,
The clock generator for generating the operation clock of the external D / A device 220 needs to be switched to the clock generator 242 for 22 kHz by the switch 238 of the clock switching mechanism 236.

That is, if the digital audio data transmitted from the PC 200 has the data format shown in FIG. 1 and the sampling frequency is 44 kHz, the operation clock of the external D / A device 220 is set to 44 kHz as described above. And DSP22
4 has a Nyquist frequency of 22 kHz
The filter is applied, and 22k is switched by the switches 230a and 230b of the analog filter switching mechanism 228.
Hz analog filter 232 had to be selected.

On the other hand, when the digital audio data transmitted from the PC 200 has a sampling frequency of 22 kHz in the data format shown in FIG. 1, the operation clock of the external D / A device 220 is set to 22 kHz as described above. And DSP22
4 has a digital Nyquist frequency of 11 kHz.
Filtered, 11k by switches 230a, 230b of analog filter switching mechanism 228
Hz analog filter 234 had to be selected.

That is, in the conventional sample data transfer system, when transferring sample data sampled at different sampling frequencies in the same system, an operation clock is set in the transfer destination device in accordance with the sampling frequency. And a means for switching the filter constant of the analog filter after the D / A conversion has to be provided, resulting in a problem that the configuration is complicated and the cost is increased.

[0012]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art,
The purpose is to process sample data sampled at different sampling frequencies without switching the operation clock and the filter constant of the analog filter after D / A conversion according to the sampling frequency at the transfer destination device. An object of the present invention is to provide a sample data transfer system capable of simplifying the configuration and reducing the cost.

[0013]

In order to achieve the above object, the present invention has been made based on the following principle.

That is, assuming that the data format shown in FIG. 3A indicates sample data sampled at a sampling frequency of 44 kHz, the transfer of the 22 kHz sample data is In the transfer source device, as shown in FIG. 3B, every other sample is supplemented with sample data having an amplitude value of 0 as other sample data, so that the apparent value is 44 kHz.
This is converted into new sample data to be sample data of z and transferred.

FIG. 4 shows a personal computer (PC) 100 as a transfer source device to an external digital / analog conversion device (external D / A device) 1 as a transfer destination device.
20 shows an example of the configuration of a sample data transfer system for performing transfer according to the above-described principle when transferring sample data to the sample data transfer apparatus 20.
In the data transfer system, digital audio data reproduced by the audio reproduction application program on the PC 100 is stored in a driver (Drive).
r) transmitted from the communication IC 104 to the external D / A device 120 via the
122.

The digital audio data received by the communication IC 122 of the external D / A device 120 is filtered in a digital signal processor (DSP) 124 and further processed by a digital / analog converter (D / A).
/ A) Digital / analog conversion (D / A conversion) at 126
And converted to analog audio data.

The analog audio data D / A converted by the D / A 126 is output to the outside through a 22 kHz analog filter 128.

When the data format shown in FIGS. 3A and 3B is used, the external D / A device 120 generates an operation clock for the external D / A device 120. 44k clock generator
The Hz clock generator 130 may be used at all times.

That is, when the digital audio data transmitted from the PC 100 has the data format shown in FIG. 3A and the sampling frequency is 44 kHz, the operation of the external D / A device 120 is performed as described above. The clock is set to 44 kHz, a digital filter having a Nyquist frequency of 22 kHz is applied in the DSP 124, and an analog filter after D / A conversion is set to 22.
A kHz analog filter 128 is used.

An audio format with a sampling frequency of 22 kHz in the data format shown in FIG.
When handling digital data, the driver 102 of the PC 100 converts the data into the data format shown in FIG. 3B, and the PC 100 outputs the data format shown in FIG.
Hz digital audio data will be transmitted. Also in this case, the operation clock of the external D / A device 120 is 44 kHz, a digital filter having a Nyquist frequency of 11 kHz is applied in the DSP 124, and a 22 kHz analog filter 128 is used as the analog filter after the D / A conversion. Is used.

Therefore, in the example of the configuration of the sample data transfer system according to the present invention shown in FIG.
6 is always generated 44 by clock generator 130
Since a clock of kHz is used as an operation clock, the sampling frequency of digital audio data is 44
Even if the frequency is 22 kHz or 22 kHz, the analog filter after the D / A conversion is 22 kHz.
A kHz analog filter 128 may be used.

As described above, by performing the conversion from the data format shown in FIG. 3A to the data format shown in FIG. 3B, the transfer destination device performs sampling at a different sampling frequency. When processing the sample data, the digital clock by the DSP is processed by software without switching the operation clock and the filter constant of the analog filter after the D / A conversion according to the sampling frequency.
The processing can be performed only by changing the filter coefficient for controlling the characteristics of the filter.

That is, according to the sample data transfer system of the present invention, when handling sample data of a plurality of sampling frequencies, for example, sample data of a sampling frequency such as half of the maximum sampling frequency or half thereof, An extremely simple system configuration can be adopted.

According to a first aspect of the present invention, there is provided a method for transmitting sample data representing a voice waveform from a source apparatus to a destination apparatus via a communication path.
In a data transfer system, the data transfer system includes a transfer source device and a transfer destination device connected by a communication path, and the transfer source device includes:
Transmitting a sample data representing an audio waveform to the transfer destination device and outputting an audio signal to the transfer destination device, wherein a series of sample data representing the audio waveform and a sampling of the series of sample data are provided. Storage means for storing information indicating a frequency, and reading out the series of sample data and the information indicating the sampling frequency from the storage means, and, in accordance with the information indicating the sampling frequency, storing the series of sample data. Data insertion means for outputting either a sequence or a new sequence of sample data obtained by inserting another sample data between the series of sample data; and The sample output by the insertion means
Transmitting means for transmitting the sequence of data and the information indicating the sampling frequency to the transfer destination device, wherein the transfer destination device performs digital processing for filtering the sequence of sample data transmitted by the transmission means. A filter, and control means for changing and controlling the characteristics of the digital filter based on the information indicating the sampling frequency transmitted by the transmission means.

According to a second aspect of the present invention, there is provided a sample data transfer system for transferring sample data representing an audio waveform from a transfer source apparatus to a transfer destination apparatus via a communication path. A source device and a destination device connected to the source device, the source device transmitting sample data representing an audio waveform to the destination device, and causing the destination device to output an audio signal. Storage means for storing a series of sample data representing an audio waveform and information indicating a sampling frequency of the series of sample data; and information indicating the series of sample data and the sampling frequency from the storage means. Is read out, and the sample data of the number corresponding to the information indicating the sampling frequency is written in the series of sample data.
Data insertion means for outputting a new sequence of sample data obtained by inserting the data between data, and the transfer destination of the sample data sequence output by the data insertion means and the information indicating the sampling frequency. Transmitting means for transmitting to the device, the transfer destination apparatus includes a digital filter for filtering a sequence of sample data transmitted by the transmitting means, and the sampling frequency transmitted by the transmitting means. And control means for changing and controlling the characteristics of the digital filter based on the information indicating

According to a third aspect of the present invention, in the first or second aspect of the present invention, the data inserting means sets the amplitude value to 0 as sample data to be inserted. The sample data to be represented is inserted.

According to a fourth aspect of the present invention, in the first or second aspect of the present invention, the data inserting means is configured to perform a predetermined operation regardless of the information indicating the sampling frequency. A sequence of a number of sample data is sequentially output, and the transmitting means sequentially transmits a predetermined number of sample data sequences output by the data inserting means as a unit.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a sample data transfer system according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 5 is a block diagram showing an example of an embodiment of the sample data transfer system according to the present invention. In the sample data transfer system shown in FIG. Waveform reproducing device 10
And a digital speaker device 30 as a transfer destination device are connected by a communication path 50, and the waveform reproduction device 10
From the digital speaker device 30 through the communication path 50
The digital speaker device 30 receives the transferred reproduction data and emits a sound based on the reproduction data.

Next, details of the configuration of the waveform reproducing device 10 and the digital speaker device 30 will be described.

First, the waveform reproducing device 10 is a device that stores a plurality of audio waveforms, transmits the audio waveform selected by the user as reproduction data to the digital speaker device 30, and emits sound.

The waveform reproducing apparatus 10 includes a clock generator 12, a reproduced data memory 14, a central processing unit (CPU) 16, an operator group 18, and a first communication IC 20.
And

The clock generator 12 generates a clock signal for synchronizing with the digital speaker device 30. In the clock generator 12, the clock signal is repeatedly generated every millisecond.

Next, the reproduction data memory 14 stores a plurality of reproduction data (n: "n" is a positive integer). The reproduction data is composed of a series of sample data representing a waveform of audio and sampling frequency information representing a sampling frequency of the series of sample data.

Here, the sampling frequency information is 0,
It is assumed that it takes a value of 1 or 2, and represents the following sampling frequency, respectively.

Sampling frequency information = 0 ... Sampling frequency 44 kHz Sampling frequency information = 1 ... Sampling frequency 22 kHz Sampling frequency information = 2 ... Sampling frequency 11 kHz Further, the CPU 16 reads the reproduction data from the reproduction data memory 14. The first communication I is read out as packet data.
Supply to C20. The details of the processing executed by the CPU 16 will be described later with reference to the flowchart shown in FIG.

The operator group 18 includes a reproduction data selection switch for the user to select the reproduction data, and a reproduction instruction switch for instructing the reproduction of the reproduction data selected by the reproduction data selection switch. It is configured.

The first communication IC 20 stores packet data sent from the CPU 16 in a built-in buffer and transmits the packet data based on a clock signal from the clock generator 12. Also,
The first communication IC 20 transmits the synchronization data based on the generation of the clock signal, and
Can be synchronized with the waveform reproducing apparatus 10.

Next, the digital speaker device 30
A second communication IC 32, a clock multiplier 34, a DSP 36 having a digital filter formed therein, a group of operators 38, a digital / analog converter (D / A) 40,
Low-pass filter (LPF) 42 and amplifier 44
And a speaker 46.

Here, the second communication IC 32 is connected to the communication path 50.
Packet data transmitted through the DSP 36
Is stored in a buffer as a sequence of sample data so that the data can be read. If the packet data is sampling frequency information, the packet data is sent to the DSP 36,
The change of the filter coefficient of the digital filter configured in the SP 36 is instructed. Further, when the synchronous data is received, the timing is immediately notified to the clock multiplier 34.

The clock multiplier 34 is connected to the second communication I
The timing (once per millisecond) notified from C32 is multiplied, and 44 clock signals (44000 per second) are generated per millisecond, and the DSP 36 and the D / A4 are generated.
Drive 0.

The DSP 36 is driven by a clock signal from the clock multiplier 34 and sequentially processes 44 kHz sample data.

The DSP 36 constitutes a digital filter as described above.
Upon receiving an instruction to change the filter coefficient from the communication IC 32, the cutoff frequency (Nyquist frequency) of the digital filter is changed. In this embodiment,
An instruction to change the filter coefficient is issued so that the following cutoff frequency is set according to the sampling frequency information.

Sampling frequency information = 0... Cutoff frequency 22 kHz Sampling frequency information = 1... Cutoff frequency 11 kHz Sampling frequency information = 2... Cutoff frequency 5.5 kHz Further, the DSP 36 controls the reverb effect. The reverberation time and the reverberation level can be set by operating the reverberation time setting operator and the reverberation level setting operator constituting the operator group 38.

It should be noted that a known technique can be applied to the processing for imparting the reverb effect, and a detailed description thereof will be omitted.

The D / A 40 is provided with a clock multiplier 34.
Is driven by a clock signal from the AK4, and performs digital / analog conversion of 44 kHz sample data.

The LPF 42 is an analog low-pass filter for blocking high-frequency components remaining during digital / analog conversion. The LPF 42 is set to have a cut-off frequency of 22 kHz corresponding to the operating frequency of the D / A 40.

Then, the analog data filtered by the LPF 42 is amplified by the amplifier 44 and is further emitted to the outside by the speaker 46.

Next, the details of the processing executed by the CPU 16 will be described with reference to the flowchart shown in FIG.

First, in the waveform reproducing apparatus 10, when the power is turned on, an initial setting process is performed (step S602). In this initialization process, initialization of the waveform reproducing apparatus 10 and initialization of a variable m for specifying selected reproduction data are performed.

When the processing in step S602 is completed, it is determined whether or not the reproduction data selection switch has been operated to perform a reproduction data selection operation (step S604).

If it is determined in step S604 that the reproduction data selection switch has been operated and the reproduction data selection operation has been performed, the variable m is changed to specify new reproduction data. (Step S6
06), and then go to step S608.

On the other hand, if it is determined in step S604 that the reproduction data selection switch has not been operated and that the reproduction data selection operation has not been performed, the process proceeds directly to step S608.

In step S608, it is determined whether the reproduction instruction switch has been operated and the operation of the reproduction instruction has been performed.

If it is determined in step S608 that the reproduction instruction switch has not been operated and the operation of the reproduction instruction has not been performed, the process proceeds to step S602.
Return to and repeat the process.

On the other hand, if it is determined in step S608 that the reproduction instruction switch has been operated and the operation of the reproduction instruction has been performed, the reproduction processing in step 610 and subsequent steps is performed.

In this reproduction processing, first, the sampling frequency information sf (m) of the reproduction data (m-th reproduction data) specified by the variable m is obtained (step S61).
0) Then, the sampling frequency information is
The data is transferred to the first communication IC 20 as packet data for transmission to the speaker device 30 (step S61).
2).

Then, when the processing of step S612 is completed, it is determined whether or not a clock signal has been generated by the clock signal generator 12 (step S614).

When it is determined in step S614 that the clock signal is not generated by the clock signal generator 12, the process of step S614 is repeated, and it is determined that the clock signal is generated by the clock signal generator 12. If so, the process proceeds to step S616 and subsequent steps.

That is, the process waits at step S614 until a clock signal is generated by the clock generator 12 which generates a clock signal every millisecond, and proceeds to step 616 when a clock signal is generated.

In step S616, step S
Sampling frequency information sf acquired in 610
The value of (m) is determined, and the sampling frequency information sf is determined.
Step S618, step S6 according to the value of (m)
20 or step S624.

First, if it is determined in step S616 that the value of the sampling frequency information sf (m) is 0, that is, if the sampling frequency is 44 kHz, the flow advances to step S618 to specify the variable m. From the reproduced data (m-th reproduced data). In other words, by repeatedly executing step 618, the sample data is sequentially acquired 44 samples at a time from the beginning.
In this case, since the sample data is transferred as a packet as it is, the sample data to be transferred is shown in FIG.
It becomes as shown in.

Note that in FIGS. 7A, 7B and 7C,
S1, S2, S3,..., S44 are columns of sample data obtained from the reproduced data, and 0 indicates 0 data having an inserted amplitude value of 0.

Next, if it is determined in step S616 that the value of the sampling frequency information sf (m) is 1, that is, if the sampling frequency is 22 kHz, the flow advances to step S620 to specify the variable m. Then, 22 new sample data are acquired from the reproduced data (m-th reproduced data). In other words, by repeatedly executing step 620, sample data is acquired sequentially 22 samples at a time from the beginning.

When the process of step S620 is completed, the process proceeds to step S622, where 0 data is inserted one by one between a series of sample data to generate 44 sample data. The sample data thus generated is to be transferred as a packet. In this case, the transferred sample data is as shown in FIG. 7B.

Further, if it is determined in step S616 that the value of the sampling frequency information sf (m) is 2, that is, if the sampling frequency is 11 kHz, the flow advances to step S624 to specify the variable m. New playback data (m-th playback data)
Get sample data for a sample. In other words, by repeatedly executing step 624, the sample data is acquired 11 samples at a time from the beginning.

When the process of step S624 is completed, the process proceeds to step S626, in which three 0 data are inserted between each of a series of sample data to generate 44 sample data. The sample data generated in this way is to be transferred as a packet. In this case, the transferred sample data is as shown in FIG.

When step S618, step S622 or step S626 is completed, the 44 samples obtained in step S618 are processed.
The data, the sample data of 44 samples generated in the chip 622 or the 4 data generated in the step S626.
The four sample data is transferred to the first communication IC 20 as packet data (step S62).
8).

Then, it is determined whether there is sample data to be acquired next (step S630).

If it is determined in step S630 that there is sample data to be acquired next, that is, if unprocessed sample data remains in the sample data of the reproduced data, the process returns to step S614. Repeat the process.

On the other hand, if it is determined in S630 that there is no sample data to be acquired next, that is, if all the series of sample data has been processed, in other words, the m-th reproduced data is reproduced. If the processing has been completed, the process returns to step S604 to repeat the processing.

Therefore, according to the sample data transfer system, even if the sampling frequency of the sample data transferred from the waveform reproducing device 10 to the digital speaker device 30 changes, the DSP 36 and the digital speaker device 30 It is not necessary to change the operation clock of the D / A 40, and as a result, LP
It is not necessary to change the cutoff frequency of F42, but simply change the filter coefficient of the digital filter formed in the DSP 36 according to the sampling frequency information. Sampling frequency information = 0... Cutoff frequency 22 kHz Sampling frequency information = 1: Cut-off frequency 11 kHz Sampling frequency information = 2: By controlling the cut-off frequency so that the cut-off frequency becomes 5.5 kHz,
It becomes possible to process sample data with different sampling frequencies transferred from the waveform reproducing device 10.

[0073]

Since the present invention is constructed as described above, the transfer destination device operates in accordance with the sampling frequency and the analog / digital data after D / A conversion.
Without changing the filter constant of the filter,
It is possible to process sample data sampled at different sampling frequencies, thereby achieving an excellent effect that the configuration can be simplified and the cost can be reduced.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a data format of general monaural 16-bit (bit) data.

FIG. 2 is a block diagram of a conventional sample data transfer system when transferring sample data from a personal computer as a transfer source device to an external digital / analog conversion device as a transfer destination device.

FIG. 3 is an explanatory diagram showing an example of a data format when data is transferred from a source device to a destination device by the sample data transfer system according to the present invention in order to explain the principle of the sample data transfer system according to the present invention; (A) shows the data format of sample data sampled at a sampling frequency of 44 kHz, and (b) shows the data format of sample data sampled at a sampling frequency of 22 kHz.

FIG. 4 is a block diagram for explaining the principle of a sample data transfer system according to the present invention, in which sample data is transferred from a personal computer as a transfer source device to an external digital / analog conversion device as a transfer destination device. FIG. 4 is a block diagram showing a case of transferring.

FIG. 5 is a block diagram showing an example of a sample data transfer system according to an embodiment of the present invention;

6 is a flowchart showing a routine of a process executed by a CPU of the waveform reproducing device in the sample data transfer system shown in FIG.

FIG. 7 shows a data format of sample data transferred from the waveform reproducing device to the digital speaker device in the sample data transfer system shown in FIG. 5, (a) shows a case where the sampling frequency is 44 kHz, (b) shows the case where the sampling frequency is 22 kHz, and (c) shows the case where the sampling frequency is 11 kHz.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Waveform generator 12 Clock generator 14 Reproduction data memory 16 Central processing unit (CPU) 18 Operator group 20 First communication IC 30 Digital speaker device 32 Second communication IC 34 Clock multiplier 36, 124 Digital signal Processor (DSP) 38 Operator group 40 Digital / analog converter (D /
A) 42 Low-pass filter (LPF) 44 Amplifier 46 Amplifier 100 Personal computer (P
C) 102 Driver 104 Communication IC 120 External digital / analog device (external D / A device) 122 Communication IC 126 Digital / analog converter (D / A
A) 128 analog filter 130 clock generator

Claims (4)

[Claims] 1. A sample data transfer system for transferring sample data representing a voice waveform from a transfer source device to a transfer destination device via a communication channel, comprising a transfer source device and a transfer destination device connected by a communication channel. The transfer source device transmits sample data representing an audio waveform to the transfer destination device and causes the transfer destination device to output an audio signal, wherein a series of sample data representing the audio waveform and Storage means for storing information indicating the sampling frequency of the series of sample data; and reading out the information indicating the series of sample data and the sampling frequency from the storage means, and according to the information indicating the sampling frequency. Output a sequence of the series of sample data, or another sample between the series of sample data. Data insertion means for performing either output of a new sample data sequence obtained by inserting data, and information indicating the sampling frequency and the sample data sequence output by the data insertion device. Transmitting means for transmitting to the transfer destination device, wherein the transfer destination device has a digital filter for filtering a sequence of sample data transmitted by the transmitting means, and has been transmitted by the transmitting means. A sample data transfer system having control means for changing and controlling characteristics of the digital filter based on the information indicating the sampling frequency. 2. A sample data transfer system for transferring sample data representing an audio waveform from a transfer source device to a transfer destination device via a communication path, comprising a transfer source apparatus and a transfer destination apparatus connected by a communication path. The transfer source device transmits sample data representing an audio waveform to the transfer destination device and causes the transfer destination device to output an audio signal, wherein a series of sample data representing the audio waveform and Storage means for storing information indicating the sampling frequency of the series of sample data; and reading the information indicating the series of sample data and the sampling frequency from the storage means, and responding to the information indicating the sampling frequency. New sample data obtained by inserting a number of sample data between the series of sample data. Data insertion means for outputting a sequence of data, and transmission means for transmitting information indicating the sampling frequency and the sampling frequency output by the data insertion means to the transfer destination device, the transfer destination The apparatus includes: a digital filter configured to filter a sequence of sample data transmitted by the transmitting unit; and a characteristic of the digital filter based on information indicating the sampling frequency transmitted by the transmitting unit. A sample data transfer system having control means for performing change control. 3. The sample data transfer system according to claim 1, wherein said data inserting means inserts sample data having an amplitude value of 0 as sample data to be inserted. Transfer system. 4. The sample data transfer system according to claim 1, wherein said data inserting means sequentially outputs a predetermined number of sample data columns irrespective of information indicating said sampling frequency. The sample data transfer system according to claim 1, wherein the transmitting unit sequentially transmits a predetermined number of sample data strings output by the data inserting unit in units.