JPH11353798A - Sound recording and reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sound recording and reproducing device capable of realizing simultaneous recording and simultaneous reproduction in plural channels efficiently and without causing any incompatibility. SOLUTION: In the case of simultaneous sound recording, a system control section 13 adds attribute data of each channel to block unit sound data from each sound recording reproducing block 10, and they are composed time sequentially to obtain one sound file. In the case of simultaneous reproduction, sound data is read out from the sound file obtained by the sound recording processing at the prescribed timing and sent to the corresponding sound recording reproducing block 10. After that, the sound data is converted into an analog signal for every sound recording reproducing block 10, these converted voice signals are composed by a signal composing unit 8.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an audio recording / reproducing apparatus, and more particularly to an audio recording / reproducing apparatus for recording audio data on a recording medium or reproducing audio data recorded on a recording medium.

[0002]

2. Description of the Related Art Conventionally, in a court or the like, a special voice recording device has been used to record the progress of a trial or the like. This audio recording device is capable of performing multi-channel and long-time recording so as to be suitable for a special use such as recording of a proceeding of a trial. When using such a sound recording device, a plurality of microphones should be connected to the judge, the prosecution, the defense,
It is installed at witness seats, jury seats, etc., and records audio input from each microphone for each channel.

[0003] As such a voice recording device,
2. Description of the Related Art There has been known an apparatus that records audio tracks on a tape-shaped recording medium such as a magnetic tape by dividing the number of audio tracks into channels.
However, in such devices, digital audio recording devices as shown below have been proposed in recent years because of difficulty in increasing the number of channels, recording time, and difficulty in securing a recording medium capable of recording for a long time. Has been reached.

[0004] This digital audio recording device is a device that converts audio into digital data and records it. To achieve long-time recording, a data compression technology, particularly a compression technology such as a waveform synthesis encoding technology, is used. Used.

[0005] By the way, speech compression such as the waveform synthesis coding technique can obtain a very high compression rate, but it is difficult to reproduce the speech when a plurality of people utter simultaneously. In some cases, it may even be difficult to determine. As described above, it is practically problematic to synthesize the input audio signals of a plurality of channels in an analog manner, convert them into digital signals, and compress them. In addition, it was extremely difficult to extract only one voice for transcription. For these reasons, the audio data input from each microphone is converted into a digital signal for each channel and recorded separately.

[0006]

However, in the case of an apparatus for recording tracks on a magnetic tape separately for each channel, it is necessary to use a special head corresponding to the recording / reproducing head. In addition, as the number of channels increases, special control is required to solve the problem of deviation between tracks and interference. As a result, the recording apparatus itself becomes expensive, and the number of channels that can be recorded or reproduced is limited.

As described above, in the case where simultaneous recording on multiple channels by a plurality of microphones is performed for a long time and a disk-shaped recording medium is used as a recording medium, an analog audio signal is converted into digital data and recorded on the recording medium. Is done. This disc-shaped recording medium is far superior to a tape-shaped recording medium in random access to any file or any recording position, but if audio data of each channel is recorded in another file, Is data that is irrelevant in time even if it is recorded at the same time.

Therefore, when such data is reproduced at the same time, synchronization is achieved only with information such as a recording start time recorded in a file header or the like.
As disclosed in Japanese Patent No. 7485, a method of recording time information data for each unit time and performing synchronization based on the data is conceivable.

However, if time data is inserted for each unit time, for example, for each frame of digital conversion for the purpose of minimizing the time lag, the time data of year, month, day, hour, minute, second, and finer unit Must be recorded until
The data volume is enormous and is not realistic.

Therefore, in the case where voices are separately recorded for each microphone (for each channel) and are synthesized and output at the time of reproduction, a time lag between channels is tolerated, or a unit of recording is sacrificed at the expense of recording time. It was necessary to insert time information data every hour.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide an audio recording / reproducing apparatus which realizes simultaneous recording and reproduction on a plurality of channels efficiently and without a sense of incongruity.

[0012]

In order to achieve the above object, a first audio recording / reproducing apparatus according to the present invention comprises: input means for inputting audio data in a plurality of channels; Means for converting into audio data in block units of length, and audio data synthesizing means for taking out the audio data in block units for each channel in time division from each channel and synthesizing them with channel attribute data for each block unit Audio file generating means for generating one audio file by time-sequentially synthesizing audio data for each block synthesized by the audio data synthesizing means; Audio file recording means for recording the audio file recorded on the recording medium, and an audio file for reading the audio file recorded on the recording medium. Reading means, means for judging which of the plurality of channels the audio data contained in the audio file read by the audio file reading means is, and a block unit contained in the audio file D / A conversion means for converting the audio data into an analog signal for each channel;
And a signal synthesizing means for synthesizing and outputting the analog signal converted for each channel by the / A conversion means.

[0013] To achieve the above object, a second aspect of the present invention is provided.
In the first audio recording and reproducing apparatus, the block unit having the predetermined length is a frame unit for encoding audio data.

[0014] To achieve the above object, a third aspect of the present invention is provided.
The audio recording and reproducing apparatus according to the first aspect, wherein in the first audio recording and reproducing apparatus, of the audio data for a plurality of channels included in the audio file read by the audio file reading means, audio data to be synthesized by the signal synthesizing means is arbitrarily selected. It can be selected for

[0015]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing a configuration of a digital audio recording / reproducing apparatus according to a first embodiment of the present invention.

The digital audio recording apparatus according to the present embodiment includes a plurality of recording / reproducing blocks 10 for inputting audio under the control of a system control unit 13 to obtain predetermined audio data and performing a reproducing process on the audio data. I have one. Here, the recording / reproducing block 10 will be described with reference to FIG.

As shown in FIG. 2, the recording / reproducing block 10 includes a microphone 1 for converting a sound into an electric signal, and a sound output from the microphone 1 is amplified by a microphone amplifier (AMP) 2 connected thereto. It has become so. The output of the microphone amplifier 2 is input to an A / D converter (A / D) 4 via a low-pass filter (LPF) 3, and the analog audio signal amplified by the microphone amplifier 2 is supplied to a low-pass filter. An unnecessary frequency band is cut by the filter 3 in order to prevent the generation of aliasing noise, and is input to the A / D converter 4. The A / D converter 4 converts an audio signal, which is an analog signal, into a digital signal, and then inputs the digital signal to a digital signal processing unit (DSP) 9.

Under the control of the system control unit 13, the digital signal processing unit 9 compresses (encodes) the audio signal converted into a digital signal by the A / D converter 4 into data in a predetermined format. Then, the data is transmitted to the system control unit 13 via the system bus 18. On the other hand, during reproduction, the digital signal processing unit 9
And performs a process of expanding and converting (decoding) the data from the system control unit 13 and transmitting the decoded digital signal to a D / A converter (D / A) 5. The D / A converter 5 functions as a D / A converter that converts audio data in block units included in the audio file into analog signals for each channel.

The audio signal converted into an analog signal by the D / A converter 5 is passed through a low-pass filter (LPF) 6 that cuts unnecessary frequency bands to reduce quantization noise, and amplifies the audio signal. (AMP) 7 is input.

The recording / reproducing block 10 is configured as described above.
Are connected to one signal synthesizer 8. The signal synthesizer 8 performs a predetermined synthesis operation on the plurality of audio signals, which will be described in detail later. Further, a speaker 11 is connected to an output end of the signal synthesizer 8, and sounds amplified by the amplifier 7 and appropriately synthesized by the signal synthesizer 8 are generated. The signal synthesizer 8 serves as a signal synthesizing means for synthesizing and outputting analog signals converted for each channel (for each recording / playback block 10) by the D / A converting means (D / A converter 5). Fulfill.

Here, the configuration of the signal synthesizer 8 will be described with reference to FIG. As shown in FIG.
Is composed of a plurality of input circuits (consisting of capacitors and resistors) connected to the output terminals of the respective recording / reproducing blocks 10, and an amplifying unit (an amplifier and an amplifier) for combining and amplifying output signals of these input circuits in an analog manner. And an output capacitor). Then, the audio signal from the recording / reproducing block 10 passes through the input circuit, is synthesized, and is amplified by the amplifying unit to operate the speaker 11.

As described above, a plurality of recording / playback blocks 10 are provided, and serve as input means for inputting audio data in a plurality of channels. Further, the digital signal processing section 9 serves as a means for converting the input audio data into audio data of a predetermined length in block units for each channel.

Returning to FIG. 1, the audio recording / reproducing apparatus of this embodiment includes a system control unit 13 for controlling the operation of each unit of the digital audio recording / reproducing apparatus. The system control unit 13 is constituted by a microprocessor (CPU), and serves as a control unit of each unit. In addition, the system control unit 13 extracts audio data in block units for each channel from the respective channels in a time-division manner and sequentially extracts the audio data. Audio data synthesizing means for synthesizing with channel attribute data for each block unit, audio file generating means for generating one audio file by synthesizing the audio data for each block unit synthesized in the audio data synthesizing unit in time series, Audio file recording means for recording the audio file generated by the audio file generation means on a predetermined recording medium, audio file reading means for reading the audio file recorded on the recording medium, audio read by the audio file reading means If the audio data contained in the file is Means for determining whether the audio data according to Le, serve as.

The system control section 13 is connected to the plurality of recording / reproducing blocks 10, and further includes a recording medium drive device 12 to which a removable recording medium 30 such as a magneto-optical disk (MO) can be mounted, A data buffer 19 for temporarily storing the converted data and an external input device 15 operated by a user are connected, and a display 17 for displaying an operation mode and the like is provided with a drive circuit 1.
6 are connected.

Further, a power control unit 14 for controlling a battery (not shown) for supplying a power supply voltage to the entire digital audio recording / reproducing apparatus is connected to the system control unit 13, and controls the power supply. It has become.

The plurality of recording / reproducing blocks 10,
A system bus 18 is connected between the signal combiner 8, the recording medium drive device 12, the power supply control unit 14, the external input device 15, the drive circuit 16, the data buffer 19 and the system control unit 13.

Further, a removable recording medium 30 for recording a signal converted (encoded) by the digital signal processing section 9 can be mounted on the recording medium drive device 12.

The data buffer 19 serves as buffer means for temporarily storing data encoded in the digital signal processing unit 9 at a predetermined timing under the control of the system control unit 13.

The external input device 15 is constituted by a keyboard which can be operated by a user, and serves as a signal supply means for giving a timing signal for starting or stopping recording of audio data for each channel.

An address control circuit (not shown) is connected to the system control unit 13, and the external input device 1
5, an appropriate address signal is given to the address control circuit, and in addition to the audio data from the digital signal processing unit 9 (or recorded in the data buffer 19),
The recording date and time, index information, and the like are recorded on the recording medium 30 based on a predetermined format.

Next, the operation of the audio recording / reproducing apparatus according to the present embodiment having the above-described configuration will be described with reference to flowcharts shown in FIGS. FIG. 5 is a flowchart showing a routine for selecting a recording / reproducing operation in the audio recording / reproducing apparatus of the present embodiment.

When the power of the audio recording / reproducing apparatus of this embodiment is turned on, the system control unit 13 performs initial setting of various circuits in the audio recording / reproducing apparatus, and furthermore, the display 1
7 is displayed (step S1). After that, it waits for a recording or reproducing operation instruction from the external input device 15 (steps S2 and S4). Then, when a recording button REC (not shown) of the external input device 15 is pressed, the system control unit 13 performs a recording processing subroutine (step S3). On the other hand, when a play button PLAY (not shown) of the external input device 15 is pressed, the system control unit 13 performs a subroutine of a play process (step S5).

The recording and reproducing operations will be described below. FIG. 6 is a flowchart illustrating a subroutine of a recording process in the audio recording / reproducing device of the present embodiment.

In response to the operation of the recording button of the external input device 15 (FIG. 5, step S2), the system control section 13 executes the recording process shown in FIG. Prior to the recording process, the user operates the external input device 15 to specify a recording / playback block 10 (channel) to be used in the recording. In response to this operation, the system control unit 13 selects the recording / playback block 10 to be used for the simultaneous recording operation (step S6), and instructs the recording / playback block 10 to start recording. In response to this instruction, the recording / playback block 10 enters the recording state (step S7).

The analog signal input from the microphone 1 is amplified by an amplifier (AMP) 2 and unnecessary high-frequency components are removed by a low-pass filter (LPF) 3.
After being converted into a digital signal by the A / D converter 4, the digital signal is input to a digital signal processing unit (DSP) 9. The digital signal processor 9 compresses the digital audio data at regular time intervals and sends it to the system controller 13 as audio data in block units.

At regular intervals (step S8), the system control unit 13 receives the audio data of each block in order from each recording / reproducing block 10, adds the channel attribute information of each block to the audio data, and adds the audio data of all the channels. Data is sequentially recorded in one audio file (steps S8 to S12). This processing is performed by the external input device 15
Is repeated until the stop button STOP (not shown) is pressed (step S13).

When a stop operation is performed in step S13, the system control section 13 ends the recording operation (step S14) and returns to the main routine (see FIG. 5).

Next, the reproduction processing operation will be described. FIG. 7 is a flowchart showing a subroutine of a reproduction process in the audio recording / reproducing apparatus of the present embodiment.

In response to the operation of the reproduction button of the external input device 15 (FIG. 5, step S4), the system control section 13 executes the reproduction processing shown in FIG. That is, when receiving the reproduction operation, the system control unit 13 instructs the recording / reproduction block 10 to start reproduction (step S15). In response to this instruction, the recording / reproducing block 10 enters the reproducing state, and the system control unit 13 continues the audio file recorded by the recording operation from the recording medium 30 mounted on the recording medium drive device 12 (step S17).

The system control unit 13 sequentially reads out the audio data in units of blocks from the recording medium 30 and determines from which channel audio data the audio data in units of blocks is based on the channel attribute data added to the read audio data. Is transmitted to the recording / reproducing block 10 corresponding to the channel attribute data, and the digital signal is converted into an analog signal for each channel (steps S18 to S23). Further, the audio signal converted into the analog signal for each channel is synthesized by the signal synthesizer 8 and output as sound from the speaker 11 (step S24).

This process is repeated until a stop button STOP (not shown) on the external input device 15 is pressed (step S25).

When a stop operation is performed in step S25, the system control section 13 ends the reproduction operation (step S26), and returns to the main routine (see FIG. 5).

Here, the plurality of recording / playback blocks 10
With reference to FIG. 3, a description will be given, with reference to FIG. 3, of a case where simultaneous recording is performed using three recording / playback blocks, that is, a case where simultaneous recording is performed on three channels. The system control unit 13 performs the above-described recording processing on the sound input from the channels 1, 2, and 3 (three recording / playback blocks 10). That is, each channel attribute data is added to audio data of a predetermined length in block units. Here, time t
The audio data processed at the timing of (1) is continuously recorded in one file in the order of channel 1, channel 2, and channel 3. Thereafter, t + 1, t + 2... T + n
In the same timing, audio data is recorded, and audio data for three channels is recorded as one audio file.

Next, referring to FIG. 4, a description will be given of the synthesis of audio signals when simultaneous playback is performed using three recording and playback blocks of the plurality of recording and playback blocks 10, that is, when simultaneous playback is performed on three channels. explain. The system control unit 13 reads the recorded audio data for the three channels from the audio file on which the recording process shown in FIG. Then, the audio data is sent to the recording / reproducing block 10 of the corresponding channel. Thereafter, the audio data is converted into an analog signal by the D / A converter 5. Thereafter, t + 1,
At the timing of t + 2... t + n, the audio data is similarly converted into an analog signal for each channel. These converted audio signals are synthesized by the signal synthesizer 8 and output from the speaker 11 as audio.

As described above, according to the audio recording / reproducing apparatus of the present embodiment, simultaneous recording and simultaneous reproduction on a plurality of channels can be performed without discomfort. In addition, it is possible to minimize the influence on the recording time. Furthermore, by searching the channel attribute data, it is also possible to perform independent reproduction for each channel, so that even when multiple people speak simultaneously,
It becomes possible to reproduce separately.

The audio recording / reproducing apparatus of the present embodiment described above can be applied, for example, to a recording / reproducing apparatus for recording a court record in a court. Hereinafter, a specific mode when the present invention is applied to such a recording / reproducing apparatus will be described. In this embodiment, a magneto-optical disk (MO) is used as a recording medium.

When a recording start command is input from an external input device such as a keyboard to the recording / reproducing device, a recording state is set.
The audio signal input from each microphone is converted and compressed for each channel, and is output as digital signal audio data from the digital signal processing unit to the system control unit. This audio data is temporarily stored in a data buffer for each channel under the control of the system control unit, and is written to the MO when the data exceeds a certain amount, such as the minimum size for writing to the MO.

Note that the audio data is output from the digital signal processing unit every conversion frame unit of about several tens of milliseconds.
Then, the system control unit adds channel attribute data of about 8 bits, which indicates which channel the data is converted to, to the audio data. Further, the audio data converted at the same timing is recorded as data of the same audio file.

For example, the audio data input to channel 1 is recorded at the timing of time t from the start address of the predetermined sector on the MO, and the audio data input to channel 2 at the timing of the same t is recorded in the area immediately thereafter. Record. Further, the same processing is performed on channels 3 to n, and recording is performed in order. The same processing is performed at the subsequent timing of t + 1.

With the above-described method, by collectively recording audio data input at the same timing on the MO, a temporal correlation can be provided between the channels.

On the other hand, in the case of reproduction, the audio data recorded on the MO is read out in the minimum unit of readout, for example, in cluster units, and once taken into the data buffer.
Here, data is read from the head address of the recording, and data from the data on channel 1 to immediately before the data on the next channel 1 is read from the data buffer based on the attribute data. In the above recording example, data from channel 1 to channel n is extracted. The data 1 to n are audio data recorded at the same timing.

The extracted audio data is converted into an analog audio signal by a recording / reproducing block for each channel, and the audio signals from all the channels are synthesized in an analog manner by a signal synthesizer and output from a speaker. At this time, since the data recorded at the same timing is continuously recorded, the sound is reproduced for each unit, so that there is no time lag between the channels, and it is possible to perform the synthetic reproduction without feeling unnatural.

Although the recording medium is a magneto-optical disk in the above embodiment, the present invention is not limited to this, and disk-shaped recording media such as an optical disk, a phase-change optical disk, a magnetic disk, DAT, 8 mm tape, VHS tape , A tape-shaped recording medium using a magnetic tape, such as a C cassette, a semiconductor memory, an IC card or the like.

Since the tape-shaped recording medium has a large recording capacity, continuous long-time recording from several hundred hours to thousands of hours can be performed. Become. In addition, a disk-shaped recording medium is capable of recording for a long time, though it is inferior to a tape-shaped recording medium, and is capable of random access. Therefore, it is a medium that is effective for purposes such as instant access to a target file or a specific conversation position, and repeat reproduction of a specific portion.

In the above embodiment, a keyboard is used as a means for inputting a command from an operator to the recording / reproducing apparatus. However, the present invention is not limited to this, and an interactive menu such as a touch panel may be used. Alternatively, it may be connected to a personal computer or the like with a communication cable of several meters or a LAN cable of several tens of meters or more, and may be remotely controlled from an external control device.

In order to use the recording capacity more effectively, it is conceivable to apply voice activation means. However, if the file is separately recorded for each channel and the voice activation recording is performed,
Absolute time management becomes difficult. The embodiment of the present invention also takes this point into consideration, and by synthesizing audio data (in block units) of another channel between main audio data (in block units) when recording is restarted by voice activation, It is also possible to easily manage the time. Alternatively, even when the number of recording channels is increased halfway, a time lag between channels can be prevented.

Further, by searching the channel attribute data, it is possible to perform independent reproduction for each channel. Therefore, even when a plurality of people utter simultaneously, it is possible to reproduce separately.

The present invention also provides multi-channel simultaneous recording and simultaneous playback using voice activation, in which only one channel performs normal recording and the other channels automatically start and stop recording depending on the presence or absence of sound. It can also be applied to a device that performs this. Therefore, according to the apparatus to which the present invention is applied, it is possible to easily perform recording by voice activation, which was conventionally difficult to reproduce simultaneously because the temporal pattern of recording differs for each channel.

[0060]

As described above, according to the present invention, it is possible to provide an audio recording / reproducing apparatus which realizes simultaneous recording and reproduction on a plurality of channels efficiently and without a sense of incongruity.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a digital audio recording / reproducing apparatus according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a recording / reproducing block in the audio recording / reproducing apparatus of the embodiment.

FIG. 3 is a diagram illustrating a specific example of a recording operation in the audio recording / reproducing device of the embodiment.

FIG. 4 is a diagram illustrating a specific example of a reproducing operation in the audio recording and reproducing device of the embodiment.

FIG. 5 is a flowchart showing a main routine in the audio recording / reproducing apparatus of the embodiment.

FIG. 6 is a flowchart showing a subroutine of a recording processing operation in the audio recording / reproducing apparatus of the embodiment.

FIG. 7 is a flowchart showing a subroutine of a reproduction processing operation in the audio recording / reproducing apparatus of the embodiment.

FIG. 8 is a block diagram showing a configuration of a signal synthesizer in the audio recording / reproducing apparatus of the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Microphone 2 ... Microphone amplifier 3 ... Low-pass filter 4 ... A / D converter 5 ... D / A converter 8 ... Signal synthesizer 9 ... Digital signal processing unit 10 ... Recording / reproducing block 11 ... Speaker 12 ... Recording medium drive device 13 ... System control unit 15: External input device 30: Recording medium Attorney Patent Attorney Susumu Ito

Claims (3)

[Claims] An input unit for inputting audio data in a plurality of channels; a unit for converting the input audio data into audio data in block units having a predetermined length for each channel; Audio data synthesizing means for sequentially extracting time-divisionally from each channel and synthesizing the channel attribute data for each block unit; and audio data for each block unit synthesized by the audio data synthesizing means in time series. Voice file generating means for generating one voice file; voice file recording means for recording the voice file generated by the voice file generating means on a predetermined recording medium; and voice file recording on the recording medium. Voice file reading means to be read, and voice file read means included in the voice file read means. Means for judging which of the plurality of channels the audio data belongs to, and D / A conversion means for converting block-by-block audio data contained in the audio file into an analog signal for each channel And a signal synthesizing means for synthesizing and outputting an analog signal converted for each channel by the D / A converting means, and a signal synthesizing apparatus. 2. The audio recording / reproducing apparatus according to claim 1, wherein the block unit having the predetermined length is a frame unit for encoding audio data. 3. The audio data to be synthesized by the signal synthesizing unit can be arbitrarily selected from the audio data of a plurality of channels included in the audio file read by the audio file reading unit. Audio recording and playback device.