JPH10112752A - Speech recording and reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To record a mixture of DTMF code data and digital voice compression data to an information recording medium by discriminating the DTMF code data and the digital voice compression data based on recording position information and recording time information recorded as header data. SOLUTION: A control section 11 separates a speech signal received by an input processing section 2 into a voice signal and a DTMF signal, the voice signal outputted from the input processing section 2 to a voice signal conversion circuit 3 is converted into digital voice compression data and the DTMF sinal outputted from the input processing section 2 to a DTMF conversion section 4 is converted into DTMF code data. Furthermore, the control section 11 controls a write conversion section 5 to generate header data consisting recording position information where the digital voice compression data and the DTMF code data are recorded and/or recording time information when they are recorded, generates recording data to synthesize the header data and outputs the recording data to a recording reproduction section 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a call recording / reproducing apparatus for recording a call signal on an information recording medium in order to maintain call contents as evidence.

[0002]

2. Description of the Related Art For the purpose of recording a large number of calls made by people continuously for a long time, a call recording / reproducing apparatus has a function capable of recording a plurality of calls for a long time without changing an information recording medium. Needed. Various technologies for performing continuous recording for a long time are employed in the call recording / reproducing apparatus.

[0003] As one of the techniques, a technique of converting a communication signal into digital communication data and compressing the digital communication data is employed. The call signal is converted into digital call data by analog-to-digital conversion (A / D conversion). This digital call data has a sampling frequency of 8 kHz and a quantity of 8 bits, ie,
It has a data amount of 64 kbps (bit per sec). If you do not compress digital call data,
Assuming that the capacity of the information recording medium is 1.2 Mbytes,
Digital communication data of the communication for about 150 seconds is recorded on this information recording medium.

Generally, data of a silent part during a call is deleted from the digital call data to reduce the amount of digital call data. When a conversation is made using a telephone, the conversation time between people is statistically about 3 hours of the conversation time.
0%. If the digital communication data of the silent part where no conversation occurs is not recorded, the amount of the compressed digital communication data can be reduced to about 30% of the amount of the uncompressed digital communication data.

[0005] The use of digital signal compression technology can further compress digital communication data. ITU (International Telec)
G. ommunication Union) of the T series recommendation. With the use of digital signal compression technology based on H.726, 64 kbps digital communication data can be reduced to about 1
/ 4. Combined with the digital communication data compression technique for eliminating silence, the data volume can be reduced to about 1/12.

However, while maintaining the conventional sound quality, 1/1
It is difficult to reduce the amount of data by two or more. One reason for this is that the numerical value that the conversation time is 30% of the talk time is merely a statistical value and can vary.

[0007] The compression ratio and sound quality of the digital signal compression technique are in a trade-off relationship. If the digital communication data is set to a compression ratio higher than 1/4, the sound quality deteriorates and is not suitable for a communication recording / reproducing apparatus which preserves the contents of communication as evidence.

It is noted that a telephone call is not necessarily limited to a conversation between humans. DTMF (DualIT) during a call
one Modulation Frequency
y) A signal may be used. In the DTMF signal, a sine wave having two frequencies is recorded as an analog signal, and numbers, characters, or symbols are assigned to combinations of frequencies.

FIG. 5 is a diagram for explaining the principle of generation of the DTMF signal. Low group frequency is 697Hz, 770Hz, 8
It consists of four kinds of frequencies of 52 Hz and 941 Hz, and the high group frequencies are 1209 Hz, 1336 Hz, and 1477 Hz.
And 1633 Hz. And
One frequency is combined from each of the low group frequency and the high group frequency to represent 16 types of symbols. Out of these 16 types of symbols, a total of 12 types of symbols including numbers from 0 to 9 and * and # symbols are used in general puffphone phones.

[0010] The DTMF signal is used not only for making a telephone call but also for various services such as a telephone reservation system for a JR express ticket or a designated ticket and a betting ticket purchase system of the JRA (Japan Central Racing Association). A person inputs a numerical value or the like by pressing a telephone button with a total of 12 types of symbols including numbers from 0 to 9, and symbols of * and #. The conventional call recording / reproducing apparatus records the DTMF signal and records the contents of the call as evidence in various services.

The DTMF signal is a number from 0 to 9,
The purpose is to represent a total of 16 types of symbols, *, # symbols, and A, B, C, and D characters. Since the DTMF signal is used on an analog telephone line, the DTMF signal is expressed as an analog signal combining two frequencies. Conventional call recording / reproducing apparatuses record DTMF signals as analog voices.

The DTMF signal, which is an analog signal, is
A method of converting the data into DTMF code data generally called character data and recording the converted data is being studied. DTM
When the F signal is converted into DTMF code data, significant compression becomes possible. When recording DTMF signals for 10 seconds as audio data, the frequency band is 8 kHz and the resolution is 8 bi.
If sampling is performed at t, the data bit rate is 64 kbps, and 640 kby for 10 seconds.
te capacity is required. On the other hand, the DTMF signal is
If it is recorded as code data, it is basically 1 byte per character.
0 bytes, resulting in a significant reduction in the amount of recording data.

An example of a communication device for converting a DTMF signal into DTMF code data is disclosed in Japanese Patent Application Laid-Open No. 2-46052. Thus, the DTMF signal is
Further reduction in the amount of data is being studied by converting the audio signal into digital-to-analog conversion (D / A conversion) and compression into digital audio compression data as F code data.

[0014]

However, when the digital signal is recorded together with the digital audio compression data and the DTMF code data generated by D / A conversion and compression of the audio signal, the DTMF code data and the digital audio compression data are not recorded. There was a problem that it could not be distinguished.

[0015]

According to an aspect of the present invention, there is provided an input processing unit for separating a speech signal input through a communication line into a voice signal and a DTMF signal; An audio signal conversion unit for converting an audio signal into digital audio compression data, and a DTMF signal
A DTMF signal conversion unit that converts the compressed audio data into F code data; a write conversion unit that adds header data indicating recording position information and / or recording time information of the digital audio compression data and the DTMF code data; A recording / reproducing unit that records DTMF code data and the header data on an information recording medium; and a control unit that controls the input processing unit, the audio signal converting unit, the DTMF signal converting unit, the writing converting unit, and the recording / reproducing unit. And the control unit converts the DTMF signal to DT
Converting the audio signal into digital audio compressed data, generating header data indicating recording position information and / or recording time information of the digital audio compressed data and the DTMF code data;
It is characterized by controlling to record on the recording / reproducing unit.

According to a second aspect of the present invention, there is provided a recording / reproducing section in which compressed digital audio data, DTMF code data and header data are recorded on an information recording medium, and wherein the recording / reproducing section reads out from the recording / reproducing section. A read conversion unit for separating the digital audio compressed data and the DTMF code data based on the recording position information and / or recording time information of the header data, and an audio signal inverse conversion unit for converting the digital audio compressed data into an audio signal When,
D for converting the DTMF code data into a DTMF signal
A TMF signal inverse conversion unit, an output processing unit for restoring the original speech signal from the voice signal and the DTMF signal, and the recording / reproducing unit, a read conversion unit, a voice signal inverse conversion unit, a DTMF signal inverse conversion unit, and an output processing unit And a control unit for controlling
The control unit transmits the DTMF code data to the DTMF code data.
And converting the digital voice compression data into the voice signal, and restoring the original speech signal from the voice signal and the DTMF signal based on the recording position information and / or recording time information of the header data. It is characterized by the following control.

The invention described in claim 3 is the first invention.
3. The call recording / reproducing apparatus according to claim 2, wherein the information recording medium of the recording / reproducing unit is a phase-change optical information recording medium, a magneto-optical information recording medium, or a write-once optical information recording medium, and as main data. The digital audio compression data and the DTMF code data are recorded, and the header data is recorded as management data for managing main data.

According to the first aspect of the present invention, when a voice signal is detected in a call signal, the voice signal is converted into digital voice compression data in a voice signal converter, and a DTMF signal is detected in the call signal. The DTMF signal conversion unit converts the DTMF signal into DTMF code data, and records digital audio compression data and DTMF code data from time to time and / or recording time information and / or digital audio compression data and DTMF code data. Is recorded on the information recording medium of the recording / reproducing unit by adding header-data which is recording position information indicating where and how much is recorded.
The recording data amount can be reduced while making it possible to distinguish between the F code data and the digital voice compression data.

According to the second aspect of the invention, at the time of reproduction, based on the header data read from the information recording medium, the digital audio compression data is subjected to audio expansion and D / A conversion by the audio signal inverse converter. It is converted and restored as a voice signal, and the DTMF code data is DTMF code data.
It is restored as a DTMF signal by the signal inversion unit. The voice signal and the DTMF signal are combined in the output processing unit and reproduced as a speech signal at the time of recording.

According to a third aspect of the present invention, an optical disc such as a phase change optical information recording medium, a magneto-optical information recording medium, or a write-once optical information recording medium is used as the information recording medium, and the digital audio The compressed data and the DTMF code data are recorded in the user recording area as main data. The header data is UTOC (User Table Of) as management data for managing main data.
Contents), it is easy to manage at what time and where the digital voice compression data and the DTMF code data are recorded.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of one embodiment of a call recording / reproducing apparatus according to the present invention, FIG. 2 is a conceptual diagram of signals output from respective components of the call recording / reproducing apparatus according to one embodiment of the present invention, and FIG. FIG. 4 is a flowchart showing a recording operation of an embodiment of the call recording / reproducing apparatus according to the present invention, and FIG. 4 is a flowchart showing a reproducing operation of an embodiment of the call recording / reproducing apparatus according to the present invention. Hereinafter, a call recording / reproducing apparatus according to an embodiment of the present invention will be described with reference to FIGS. Here, the symbols a to f laid down on the side of the signal line in FIG. 1 correspond to the signals shown in FIGS. 2A to 2F, and the signals of the signal line and The data shall be illustrated.

The interface unit 1 converts a call signal transmitted via a telephone line into a call signal used inside the call recording / reproducing apparatus. The speech signal output from the interface unit 1 is a mixture of a voice signal and a DTMF signal as shown in FIG. Input processing unit 2
Separates the voice signal and the DTMF signal from the call signal output from the interface unit 1. From the input processing unit 2, an audio signal as shown in FIG. 2 (b) is output to the audio signal conversion unit 3, and a DTMF signal as shown in FIG. 2 (c) is output to the DTMF signal conversion unit 4. You.

The audio signal converter 3 first converts an analog audio signal into digital audio data by A / D conversion, and further converts the digital audio data into digital audio compressed data as shown in FIG. , To the write conversion unit 5. The DTMF signal converter 4 converts the DTMF signal, which is an analog signal, into a DTMF signal as shown in FIG.
The data is converted into F code data and output to the write conversion unit 5.

The write conversion unit 5 adds header data indicating time information to the digital audio compression data and the DTMF code data. This header data will be described later. Then, the header data, the digital audio compression data and the DTMF code data are combined to generate recording data as shown in FIG. Here, for the sake of simplicity, in FIG. 2D, FIG. 2E and FIG. 2F, the digital audio compression data and the DTMF code data have the same time as the audio signal and the DTMF signal. As shown. However, actually, the recording time is shortened by the compression of data. The recording data is recorded on the information recording medium by the recording / reproducing unit 6. The recording / reproducing unit 6 is a recording / reproducing apparatus using a phase change optical disk, a magneto-optical disk, a write-once optical disk, or the like, but in the present embodiment, a recording / reproducing apparatus using a mini-disk which is a magneto-optical disk will be described. do.

The reproduction is as follows. Recording / playback unit 6
2 (f) read from the information recording medium is input to the read conversion unit 7 and separated into header data, compressed audio data, and DTMF code data. Figure 2
The digital audio compression data as shown in FIG. 2D is output to the audio signal inverse converter 8 and the DTMF code data as shown in FIG.

The audio signal inverse converter 8 converts digital audio compression data into digital audio data. Then D /
The digital audio data is converted into an analog audio signal as shown in FIG. The DTMF signal inverse converter 9 converts the DTMF code data into a DTMF signal as shown in FIG.

The output processing unit 10 outputs the audio signal and the D signal.
The original speech signal as shown in FIG. 2A is restored from the TMF signal. This call signal is output to the interface unit 1 or an audio amplifier (not shown). When the call signal is output to the interface unit 1, the call signal is converted into a call signal used for the telephone line. When the call signal is output to an audio amplifier (not shown), the call signal is converted by the audio amplifier. It is amplified and reaches the human ear through a speaker.

From the interface unit 1 to the output processing unit 10
The components described above are connected to the control unit 11. At the time of recording, the control unit 11 separates the speech signal input to the input processing unit 2 into a voice signal and a DTMF signal, and converts the voice signal output from the input processing unit 2 to the voice signal conversion unit 3 into digital voice compression data. DTMF signal output from the input processing unit 2 to the DTMF conversion unit 4
Control to convert to code data.

The control unit 11 also includes a write conversion unit 5
Generates header data, which is recording position information indicating where the digital audio compression data and DTMF code data are recorded and / or recording time information indicating when the digital audio compression data and DTMF code data are recorded, and generates digital audio compression data. Data, DTMF code data, and header data are combined to generate recording data, and control is performed to output the recording data to the recording / reproducing unit 6.

At the time of reproduction, the control unit 11 controls the recording / reproduction unit 6
The recording data output to the conversion unit 7 is converted into digital voice compression data and DTM based on the header data.
The digital audio compressed data output from the read conversion unit 7 to the audio signal inverse conversion unit 8 is converted into an audio signal, and the DTMF code data output from the read conversion unit 7 to the DTMF inverse conversion unit 9 Is converted to a DTMF signal. Also, the output processing unit 10 controls to restore the original speech signal from the voice signal and the DTMF signal.

The format of the recording data recorded on the information recording medium is as shown in FIG. FIG.
How the compressed digital voice data and the DTMF code data of (f) are recorded is determined by the header data. The header data is recorded in a UTOC area which is an area for managing main data of the mini disc. Thereby, the digital voice compression data and DT
The time and place where the MF code data is recorded can be determined.

Specifically, Heisei x year x month x day x hour x minute x
First DT from second to Heisei x year x month x day x hour x minute x second
MF code data, Heisei x year x month x day x hour x minute x
From the second to the Heisei x year x month x day x hour {minute} second, it is recorded as the first digital audio compression data. Also, the main data a to b on the mini-disc correspond to the first DT.
The fact that MF code data is recorded and that the first digital audio compression is recorded from c to d of the main data on the mini-disc is recorded as header data. From this header data, it can be determined whether the data is digital voice compression data or DTMF code data.

If the digital voice compression data and the DTMF code data are recorded in track units, it becomes possible to manage them in track units. Also, record data for one call
Tracks as digital audio compressed data and D
It can be assumed that the management of the TMF code data is performed in index units. Various methods of managing the main data can be considered.

A magnetic tape is considered as a case where the information recording medium is other than the optical disk. First, header data is recorded at the head of the information recording medium, and the header data records year, month, day, hour, minute, second, data type, data position, and the like.

Specifically, Heisei x year x month x day x hour x minute x
First DT from second to Heisei x year x month x day x hour x minute x second
MF code data, Heisei x year x month x day x hour x minute x
From the second to the Heisei x year x month x day x hour {minute} second, it is recorded as the first digital audio compression data. The header data indicates that the first DTMF code data is recorded from a to b on the magnetic tape and the first digital audio compression is recorded from c to d on the magnetic tape. It is recorded as.

The information recording medium is SMPTE (Society of Mo
tion Picture & Television Engineers) or EBU
(European Broadcasting Union) may be used to record the time code, match the time code with the recording time information of the header data, and determine the data.

FIG. 3 is a flowchart showing a recording operation of the embodiment of the call recording apparatus according to the present invention. Step S1 is a step indicating start. The recording / reproducing apparatus is powered on and is waiting for a telephone call bell. Step S2 is a step of receiving a telephone call. Initiate recording automatically in response to incoming call bells.

In step S3, the call signal is a voice signal or DT
This is a step of determining whether the signal is an MF signal. Integrated circuits that determine whether or not a signal is a DTMF signal are commercially available and widely used. The DTMF signal is determined using such an integrated circuit. If the call signal is a voice signal, the voice signal extracted from the call signal is output to the voice signal converter 3, and the process proceeds to step S4. If the call signal is a DTMF signal, the DTMF signal extracted from the call signal is output to the DTMF signal converter, and the process proceeds to step S6. Step S4 is a step in which the audio signal converter 3 converts the audio signal, which is an analog signal, into digital audio data by the A / D converter of the audio signal converter 3.

Step S5 is a step of further converting the digital voice data converted by the voice signal converter 3 into compressed digital voice data in the voice signal converter 3. The digital voice compression data is output to the write conversion unit 5. Step S6 is a step in which the DTMF signal conversion unit 6 changes the DTMF signal into a DTMF data code. If the DTMF data code is a character code, it is data of 8 bits per character, that is, about 1 byte per character. This DTMF code data is output to the write conversion unit 5.

Step S7 is a step in which the write conversion section 5 generates header data as recording position information and / or recording time information. The control unit 11 temporarily stores the generated header data. In step S8, the generated digital voice compression data, DTMF
This is a step of recording the code data and the header data on the information recording medium. The audio signal and the DTMF signal are sequentially recorded on the information recording medium, and each time the audio signal and the DTMF signal are switched, the control unit 11 updates the header data of the information recording medium.

Step S9 is a step for determining whether or not the recording process has been completed. If the call has been completed, the process proceeds to step S10 assuming that the recording process has been completed. If the call has not been completed, the process jumps to the beginning of step S3 to continue the recording process, and returns.
Hereinafter, the call recording process is continued. Step 10 is a step of terminating the call recording process.

FIG. 4 is a flowchart showing a reproducing operation of the embodiment of the call recording apparatus according to the present invention. Step S11
Is a step indicating start. In order to reproduce the recorded data from the recording / reproducing device, a play button of the call recording / reproducing device is pressed. Step S12 is a step of reading recording data from the information recording medium. The recording data read from the information recording medium is output to the read conversion unit 7.

Step S13 is a step in which the header data is separated from the read recording data and read to the control unit 11. The read conversion unit 7 separates digital voice compression data, DTMF code data, and header data from the recording data, and
Output to Step S14 is a step of determining whether the separated recording data is digital voice compression data or DTMF code data. Based on the header data, the control unit 11 controls the digital voice compression data or DTMF
It is determined whether the data is code data, and if the data is digital voice compression data, the data is output to the voice signal inverse conversion unit 8 and then step S
Proceed to step 15 for DTMF code data.
After outputting the signal to the signal inverse conversion unit 9, the process proceeds to step S17.

Step S15 is a step in which the digital audio compressed data is expanded and converted into digital audio data in the audio signal inverse converter 8. Step S1
Reference numeral 6 denotes a step of converting the digital audio data converted by the audio signal inverse conversion unit 8 into an analog audio signal. The converted audio signal is output to the output processing unit 1
Output to 0.

Step S17 is a step in which the DTMF signal inverse converter 9 converts DTMF code data into a DTMF signal. The DTMF signal is output to the output processing unit 1
Output to 0. Step S18 is a step in which the output processing unit 10 combines the voice signal and the call signal to generate a call signal, and outputs the signal to the interface unit 1 or a sound amplifier (not shown).

Step S19 is a step for judging whether or not the reproduction processing has been completed. If the reproduction has been completed, the process proceeds to step S19. If the reproduction has not been completed, it is determined that the reproduction process is to be continued in step S12.
Jumps back to the beginning, and then continues the reproduction process.
Step 20 is a step of terminating the call recording process.

[0047]

According to the call recording and reproducing apparatus of the present invention, D
Even if both the TMF code data and the digital audio compression data are recorded, the DTMF code data and the digital audio compression data are determined based on the recording position information and the recording time information recorded as the header data.
TMF code data and digital audio compression data can be mixed and recorded on one information recording medium.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of a call recording / playback apparatus according to the present invention.

FIG. 2 is a conceptual diagram of a signal output from each component of the embodiment of the call recording / reproducing apparatus according to the present invention.

FIG. 3 is a flowchart of a recording operation of a call recording apparatus according to an embodiment of the present invention;

FIG. 4 is a flowchart of a reproducing operation of the embodiment of the call recording device according to the present invention.

FIG. 5 is a view for explaining the principle of generation of a DTMF signal.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Interface part 2 ... Input processing part 3 ... Audio signal conversion part 4 ... DTMF signal conversion part 5 ... Write conversion part 6 ... Recording / reproduction part 7 ... Read conversion part 8 ... voice signal reverse conversion unit 9 ... DTMF signal reverse conversion unit 10 ... output processing unit 11 ... control unit

Claims (3)

[Claims] An input processing unit for separating a speech signal input through a communication line into a voice signal and a DTMF signal; a voice signal conversion unit for converting the voice signal into digital voice compressed data; and a DTMF code for the DTMF signal. D to convert to data
A TMF signal conversion unit; a write conversion unit for adding header data indicating recording position information and / or recording time information of the digital audio compression data and the DTMF code data; and the compression audio data, the DTMF code data and the header. A recording / reproducing unit for recording data on an information recording medium, the input processing unit, the audio signal converting unit, and the DTM
An F signal conversion unit, a control unit for controlling the write conversion unit and the recording / reproduction unit, the control unit converts the DTMF signal into DTMF code data, and converts the audio signal into digital audio compression data A call recording / reproducing device for generating header data indicating recording position information and / or recording time information of the digital voice compression data and the DTMF code data, and controlling to record the header data in the recording / reproducing unit. 2. A recording / reproducing section in which compressed digital audio data, DTMF code data and header data are recorded on an information recording medium, and the digital audio compressed data and DTMF code data read from the recording / reproducing section. A read conversion unit that separates the digital data based on the recording position information and / or recording time information of the header data, an audio signal inverse conversion unit that converts the digital audio compressed data into an audio signal, and a DTMF signal that converts the DTMF code data into a DTMF signal. Convert to D
A TMF signal inverse conversion unit, an output processing unit for restoring an original speech signal from the voice signal and the DTMF signal, the recording and reproduction unit, a read conversion unit,
A control unit that controls an audio signal inversion unit, a DTMF signal inversion unit, and an output processing unit, wherein the control unit converts the DTMF code data into the DTMF code data.
And converting the compressed digital audio data into the audio signal, and restoring the original speech signal from the audio signal and the DTMF signal based on the recording position information and / or the recording time information of the header data. A call recording / reproducing apparatus characterized by performing control as described above. 3. The communication recording / reproducing apparatus according to claim 1, wherein the information recording medium of the recording / reproducing unit is a phase change optical information recording medium, a magneto-optical information recording medium, or a write-once optical information recording medium. A call recording / reproducing apparatus, which is a recording medium, wherein the digital voice compression data and the DTMF code data are recorded as main data, and the header data is recorded as management data for managing the main data.