JPS62275369A - Data recorder - Google Patents

Abstract

PURPOSE:To obtain a data recorder suited to record a continuous data for a long time by preparing a corresponding table of the input time points of the recorded input data and the discontinuous specific sectors of a memory device storing the continuous input data after dividing them into sectors. CONSTITUTION:A control circuit 8 increases the value of an address counter 8b and at the same time reads successively the time codes out of the discontinuous 256 regular sectors of an optical disk device 1 in the order of younger addresses of those sectors. Then these read codes are successively written to a read table 10 at and after the head one. Thus a correspondence table is formed into the table 10. The correspondence table contains the absolute addresses of those prescribed 256 sectors and the input time points of voice data recorded to each sector. Then the circuit 8 inputs the correspondence table, i.e., the table 10 to the disk 1 via a switch circuit 9.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention [Technical Field] The present invention relates to a data recording device, and more particularly to a data recording device suitable for long-term recording of audio data.

[Prior art]

Conventionally, magnetic tape recorders have generally been used to record audio such as telephone communications and radio communications.

However, when recording is performed over a long period of time, there is a problem in that it takes time to search for the desired recorded content during playback.

〔the purpose〕

Therefore, an object of the present invention is to solve such problems and provide a data recording device suitable for long-term recording of temporally continuous data such as audio data.

〔composition〕

In order to achieve this object, the data recording device of the present invention includes a storage device that can be accessed in sector units, a means for dividing temporally continuous input data into sector units and recording it in the storage device, and The present invention is configured to include means for creating a correspondence table between randomly specified sectors of the storage device and input times of input data recorded therein.

〔Example〕

An embodiment of the present invention will be described in detail below with reference to one drawing.

FIG. 1 is a schematic block diagram of one embodiment of the present invention. This embodiment is intended for recording audio input through a telephone line, and has a storage capacity of 700 MB (megabytes) as a storage device that can be accessed in sector units.
This optical disk device 1 is adopted.

First, the configuration and operation related to recording will be explained. Once the telephone line is connected and an audio signal is input,
The signal detection circuit 2 turns on the detection signal line 2a. Further, the audio signal is inputted to the compression circuit 3. This compression circuit 3
, the audio signal is digitized and then ADP
Data is compressed using the CM method. In the case of the ADPCM system, up to about 48 hours worth of audio data can be continuously recorded on the optical disk device 1.

4 is a real-time clock, which generates time information. This time information is input to the time code adding circuit 5.

In response to turning on of the detection signal line 2a, the time code addition circuit 5 creates an 8B (byte) time code (additional information) including time information and a start mark, and inputs it to one audio manual buffer 7A. Such operations are controlled by the control circuit 8. Following that, compression circuit 3
The audio data (compressed data) outputted from the audio data buffer 7A is sequentially input to the audio manual buffer 7A, and is stored in sequence following the time code.

Note that a total of 2048B consisting of such a time code and 2040B of audio data is treated as data for one sector.

The control circuit 8 monitors the number of input bytes of audio data by a byte counter 8a, and after the time code, 2
When 040B worth of audio data is input, that is, when one sector worth of data is input, the time code addition circuit 5 is again instructed to add a time code. In response to this instruction, the time code is again input from the time code adding circuit 5 to the audio manual buffer 7A. The time code at this time includes a continuous mark instead of a start mark. Subsequently, the audio data is input to the audio buffer 7A and sequentially stored.

In this way, when 3 sectors worth of data, that is, 6144B of data, is accumulated in the audio manual buffer 7A, the byte counter 8a generates a carry signal and is reset.
The control circuit 8 then controls the other audio manual buffer 7B to similarly input the time code and audio data.

Further, in parallel with this input operation, the control circuit 8 sequentially outputs three sectors worth of data accumulated in the audio input buffer 7A, inputs it to the optical disk device 1 via the switch circuit 9, and inputs the data. Control is performed so that one sector is sequentially stored in sectors at consecutive addresses.

When three sectors worth of data is stored in the audio input buffer 7B, the data is written to the optical disk device 1, and in parallel, data is sequentially stored in the audio manual buffer 7A.

Thereafter, similarly, the audio data covers 7A and 7B are used alternately, the audio data is divided into sectors, and a time code containing information on the input time is added to the beginning of each sector so that the audio data can be continuously transmitted to the optical disk device 1. The data will be recorded sequentially in the sectors of the addresses.

When the signal detection circuit 2 detects a silent period longer than a specified time, it turns off the detection signal line 2a. As a result, the control circuit 8 determines that the input has ended, and instructs the time code addition circuit 5 to add a time code including an end mark. In response to this, the time code including the end mark is input from the time code addition circuit 5 to the audio manual buffer 7A or 7B. One sector worth of data with this time code added to the beginning is recorded on the optical disk device 1.

FIG. 2 shows the format of one sector of data and the structure of the time code. In this figure, the entire time code is 8B, and X-L to xL are each 4-bit B.
This is the CD code. Year, X, and x in X engineering and x2
4 is the month, X, and x6 is the day, x7 and X, is the hour, x
9 and xl. Minutes in minutes, X□□ and XL, seconds in
and XX4 respectively display 1/100th of a second. X engineering,
is used as a start mark, continuation mark, or end mark, which is a sector status flag. The last one, xl, is reserved and unused.

Note that if the audio signal is input again after the input is determined to have ended due to a silent period of a certain length, the audio data is similarly divided into sectors, and a time signal containing information about the input time is divided into sectors. A code is added and the data is recorded sequentially starting from the sector following the last sector recorded last time.

Now, the control circuit 8 also determines the end of recording using the address counter 8b. In this embodiment, when the address of the final sector of the optical disk device 1 and the value of the address counter 8b match, the control circuit 8 determines that recording has ended, and even if audio data continues to be input, the recording operation continues. , and move on to creating the next correspondence table.

In this embodiment, the last sector of optical disk device ll is used as the correspondence table. That is, the control circuit 8 increments the value of the address counter 8b by a predetermined value, and transfers the time codes stored in 256 specified sectors of the optical disk device 1 to the sectors with the smallest addresses. sequentially read out
Then, the time codes are written into the reading table 10 in order from the beginning.

In this way, a correspondence table as shown in FIG. 3 is created in the read table 10. This correspondence table is a table that associates each absolute address of 256 predefined sectors with the input time of audio data recorded in each sector. Thereafter, the control circuit 8 inputs the correspondence table created in the read table 10 to the optical disk device 1 via the switch circuit 9.

It is recorded in the last sector.

In the case of continuous recording, the input time and recording address of recording data for a maximum of 48 hours can be managed in units of about 11 minutes using this correspondence table. Therefore, as will be described later, it is possible to efficiently search for data at a desired time during playback based on this correspondence table.

The reason for creating a correspondence table for discrete sectors instead of creating a similar correspondence table for all addresses is to avoid the following disadvantages. In other words, since the number of sectors becomes enormous when long-term recording is desired, if a similar correspondence table is created for all sectors, a considerable amount of storage space of the optical disk device 1 will be consumed to store it. This may cause restrictions on the recording time of necessary data and may lead to an increase in device costs. Furthermore, if the correspondence table becomes large in this way, there is a risk that the time required to refer to it and search for a storage sector for desired data may conversely increase.

Next, the configuration and operation related to reproduction of recorded data will be explained. When the reproduction mode is specified by the mode line 8c, the control circuit 8 operates in the reproduction mode.

First, the control circuit 8 reads the correspondence table from the last sector of the optical disk device 1 and writes it into the read table 1o.

Generally, the recording medium (optical disk) of the optical disk device 1 is replaceable, so for each loaded recording medium,
The contents of the corresponding table are different. Therefore, a correspondence table is recorded on the recording medium side, and at the time of reproduction, the correspondence table unique to the recording medium is read out to the read table 10.

Next, the control circuit 8 activates the sector search circuit 11.

This sector search circuit 11 searches the recording sector of the audio data input at the time specified by the time input line 12 by referring to the corresponding table on the read table 10, and sends the sector address to the control circuit 8. This is the circuit that reports.

As described above, the recording sector and time of audio data can be determined in units of about 11 minutes using the correspondence table. Therefore, even if you compare the time indicated by the time code on the correspondence table with the specified time, search for the sector address corresponding to the closest time code before the specified time, and start data playback from that sector, playback will start. The maximum error between the input time of audio data and the specified time is about 11
It can be held down in minutes.

However, in order to further reduce this error and significantly shorten the time it takes to start playing the desired audio data,
In this embodiment, the sector search circuit 11 searches for the target sector in the following manner.

Searched.

The sector search circuit 11 searches the correspondence table for the time code that indicates the time closest to the specified time At by the time input line 12. Next, the sector search circuit 11 searches the correspondence table for the time code that indicates the time closest to the specified time At by the time input line 12. Assuming that the sector addresses are B and C, D=(B+C)/2 is calculated, and the control circuit 8 is instructed to read the recorded data of the sector at address D.

The time code of the recorded data is input from the time code detection circuit 13 to the sector search circuit 11.

The sector search circuit 11 determines the display time D of the time code.
t and the designated time At are compared to check the context and difference between the two. If the difference is large, E=(A+D)/2 is calculated, the recorded data of the sector at address E is read out, and the display time of the time code is compared with the specified time At. Thereafter, in the same manner, the sector in which data at the closest time before the specified time At is recorded is searched.

In this way, once the desired sector is found.

The sector search circuit 11 sends the address of the sector and a search completion report to the control circuit 8 (the sector address is set in the address counter 8b).

In response, the control circuit 8 causes the optical disk device 1 to output the recording data of the sector at the designated address.

The read data is inputted to one audio output buffer 14A after the time code is removed by the time code detection circuit 12. When the audio data of that sector is input to the audio output buffer 14A to the end, the control circuit 8 sequentially inputs the audio data to the expansion circuit 15 in synchronization with a specified clock. In parallel with this, the control circuit 8 causes the storage data of the sector of the next address to be output,
The audio data is input to the other audio output buffer 14B.

When the audio output buffer 14A runs out of data.

The control circuit 8 sequentially inputs the data of the other audio output buffer 14B to the decompression circuit 15, and in parallel inputs the stored data of the primary sector to the audio output buffer 14A. In this way, the audio output buffers 14A, 14B
are used alternately, and the audio data stored in consecutive sectors is continuously input to the decompression circuit 15. The audio data is expanded by an expansion circuit 15 and then input to a public address system 16, where it is reproduced as audio.

In this way, continuously input audio data is automatically and continuously reproduced. When the time code detection circuit 13 detects the end mark and receives the detection signal, the control circuit 8 stops reading the next sector, and starts playback when the audio output buffers 14A and 14B are empty. to stop.

Although one embodiment has been described above, the present invention is not limited thereto.

For example, in the embodiment described above, time information may be recorded only in discrete sectors that are directly related to the creation of the correspondence table.

Alternatively, the correspondence table may be created at the same time as input data is recorded. In that case, it is not necessarily necessary to record additional information including time information in the sector.

Instead of the optical disk device, it is also possible to use other storage devices that can be accessed in sector units.

The data recording format can also be changed as appropriate.

Other configurations may also be modified in various ways without departing from the gist of the present invention.

Furthermore, the present invention can be similarly applied to the recording of code data that is input continuously in time, other than audio data.

〔effect〕

As is clear from the above description, in the present invention, continuous input data for two hours is divided into sectors and recorded in a storage device that can be accessed sector by sector. By creating a correspondence table between sectors and the input times of the input data recorded in them, it is possible to realize a data recording device that can quickly search and reproduce input data at a desired time even if the recording time is long. .

[Brief explanation of the drawing]

FIG. 1 is a schematic block diagram showing a simplified functional configuration of an embodiment of the present invention, FIG. 2 is an explanatory diagram of sector-based data and time codes, and FIG. 3 is an explanatory diagram of a correspondence table. 1... Optical disk device, 2... Signal detection circuit, 3
... Compression circuit, 4... Real-time clock. 5... Time code addition circuit, 7A, 7B... Audio input buffer, 8... Control circuit, 10... Readout table, 1
1... Sector search circuit, 13... Time code detection circuit, 14A, 14B... Audio output buffer,
15... Expansion circuit, 16... Expansion device.

Claims (1)

[Claims] (1) A storage device that can be accessed in sector units, a means for dividing temporally continuous input data into sector units and recording them in the storage device, and a means for dividing temporally continuous input data into sector units and recording them in the storage device; A data recording device comprising means for creating a correspondence table between input data and input times.