JPH04341970A - Circuit for intermittent reproduction of compressed sound data - Google Patents

Abstract

PURPOSE:To make it possible to process completed data, and in addition, to make its reproduction processing sure and easy by reproducing intermittently an intermittent-recorded track for every recording unit. CONSTITUTION:In the case that a disk record D rotated at constant linear speed by a disk motor 20 is reproduced, when an area capable of storing becomes larger than the data of the portion of the recording unit, a data quantity detecting means 35 generates a reproduction command signal, and the continuous reproduction is executed, and when terminal end detection output is generated from a record terminal end detecting means 32 in a state that the reproduction command signal is erased, the reproduction is interrupted, and a device is turned into a reproduction waiting state, and simultaneously with the regeneration of the reproduction command signal, the reproduction is restarted, and a reproducing state is continued. Then, synchronously with the generation of the terminal end detection output, the device is turned again into the reproduction waiting state. Thus, the intermittent reproduction of every recording track unit is performed.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intermittent reproduction circuit for reproducing a recording disk record formed by intermittently recording compressed audio data.

0002

[Prior Art] A CD-I format disc record compresses and time-divisionally records the audio data of many channels on one recording track, and the playback device only records audio information selected from the playback signal. The data is expanded and converted into an audio signal.

0003

[Problem to be Solved by the Invention] However, the CD-I format disc record is not a format suitable for recording and playing back two-channel audio data compressed. Recording is performed with many gaps left in the recording track, resulting in a significant drop in recording efficiency.

[0004] Therefore, it is conceivable to record compressed audio data intermittently every predetermined amount and to form one recording track by connecting these intermittent recording tracks.

However, when data is reproduced across intermittent recording tracks in a range different from that recorded, not only does data processing become complicated, but reproduction errors are likely to occur at the start and end of reproduction.

[0006]

[Means for Solving the Problems] Therefore, the present invention provides a disk in which continuous recording tracks are formed by intermittently recording recording data in which end identification data is added to the end of a predetermined amount of compressed audio data. In a playback device for playing records, a storage means for storing playback data at high speed and sequentially reading out the stored data, a data amount detection means for detecting when the amount of stored data has become less than a certain amount, and the storage means a recording end detecting means for detecting end identification data from the reproduced data; and a recording end detecting means for detecting end identification data from the reproduced data; and in response to the end detection output, continuous reproduction scanning is interrupted to enter a reproduction standby state, and the data amount is detected. The present invention is characterized by further comprising a reproducing means for starting reproduction from the next recording start end in accordance with the output of the means.

[0007]

[Operation] Therefore, according to the present invention, when a disk record rotating at a constant linear velocity is played back, playback is started from the recording start end of the intermittent recording track when the amount of data stored in the storage means becomes less than a certain level. The reproduction is interrupted at the timing when the end of recording is detected, and the reproduced data is supplied to the storage means at high speed. The data stored in the storage means is
The audio data is sequentially read out at low speed, decompressed, and restored to the original audio data.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a magneto-optical disk recording and reproducing system will be described below.

FIG. 1 is a block diagram of a reproducing circuit of a reproducing apparatus of this embodiment, FIG. 2 is a block diagram of a recording circuit of a recording apparatus of this embodiment, and FIG. 3 is a diagram illustrating the principle of signal processing of this embodiment.

First, in this embodiment, guide tracks are formed in advance on the recording surface of the disc record, as in the conventional case.
This guide track is made to meander with a signal FM modulated using an ATIP code, and is reproduced as a tracking error signal during recording or reproduction. Further, the center frequency of the carrier of the FM signal is set to 22.05 MHz, and is used as a pilot signal for the disk servo during recording and reproduction. Further, the ATIP code indicates an absolute address from the recording start end to the recording end of the guide track, and is composed of information on minutes, seconds, and 1/75 second subcode frame number, and is recorded on the guide track at the subcode frame period. ing. The configuration described above is a well-known configuration as a format for a rewritable disc record.

The signal processing principle of this embodiment will be explained below with reference to FIG. In this embodiment, 2-channel audio signals are AD converted to 16 bits at 44.1 KHz and 1.
4112 bits/second audio data is formed. This data is 2352 per subcode frame as shown in the figure.
Become a part-time worker. In this example, this AD conversion data is 1/
Data is compressed to 5. With this data compression, 1/1
Five seconds worth of audio data is compressed to 2325 bytes as shown. This compressed data is temporarily stored in memory,
The data is read out in units of 2048 bytes (2K bytes) and converted into a CD-ROM format signal. CD-
As shown in the figure, the ROM format signal has 12 bytes of sync data and 4 bytes of header at the beginning, followed by 2048 bytes of data, and 28 bytes of data per subframe.
8 bytes of correction data is added, making up a total of 2352 bytes. This CD-ROM format data is subjected to CD-DA encoding processing and converted into data of 3136 bytes per subcode frame. Note that one subcode frame is composed of 98EFM frames, and when encoding CD-DA,
Interleaving processing is performed in units of EFM frames. Further, in this embodiment, 350 Kbytes of compressed audio data for approximately 10 seconds are continuously read out from the memory and converted into continuous data in CD-ROM format. As shown in the figure, this continuous data includes a link block of 1 subcode frame and a lead-in block of 2 subcode frames preceding the data of 175 subcode frames, and a lead-out block of 2 subcode frames following the data. A link block of one subcode frame is provided. Therefore, in this example, 181 (=
3+175+3) Approximately 2.4 seconds of recording data with a subcode frame as a recording unit is formed as an intermittent recording track, and link blocks are recorded as start and end end identification data at the beginning and end of the intermittent recording track, respectively.

The magneto-optical recording operation of this embodiment will be explained below with reference to FIG. First, two-channel stereo audio is supplied to the A/D conversion means 1 as a recording signal. This A/D conversion means 1 converts each sample into 16 bits using a 44.1 KHz conversion clock similar to the CD format. This A/D converted data is supplied to the next stage data compression means 2 and is compressed to 1/5. This compressed audio data is sequentially stored in the memory 3. The above-mentioned operation is executed before the recording mode is set, and the write address in the memory 3 is updated to cyclically store compressed audio data. Inside this memory 3, there is a storage area 3a that functionally stores compressed data, a readout area 3b that has already stored 350K bytes of compressed audio data and reads out the stored data at once according to a readout command.
It is divided into a spare area 3c which functions when the storage amount of compressed audio data increases due to a recording failure or the like and the storage area becomes insufficient.

The write/read control means 4 controls writing to and reading from the memory 3 when setting the recording mode, and constantly updates and stores the compressed audio data while specifying the write address, and also updates and stores the compressed audio data while specifying the write address. The number of read addresses during update suspension is greater than the predetermined amount, that is, 35 in the storage area 3b.
When compressed audio data of 0K bytes or more is stored, the storage area is used as a readout area, the readout address is updated, and the data is supplied to the memory 3 to continuously read out the stored data.

The write/read control means 4 also sends a read command signal to the track jump control means 13 and the CD-R to instruct the execution of intermittent recording in conjunction with the update of the read address.
It is supplied to the OM encoder 5, CD-DA encoder 6, magnetic head drive means 7, and pickup 10 to put each means into operation.

As a result, the read storage data is converted into data in the aforementioned CD-ROM format by the CD-ROM encoder 5 to be recorded data, and then inputted to the CD-DA encoder 6. The recorded data is converted into a CD format signal, and is supplied to the magnetic head drive means 7 from the recording start position, and magnetic field modulation is started from the recording start position.

Furthermore, the track jump control means 13
During the recording standby period, a track jump pulse is supplied to the tracking coil drive circuit 15 to continuously reproduce the same ATIP code at the end of the previous intermittent recording track, and the recording standby state is maintained for about 7.6 seconds. However, during the generation period of the read command signal, generation of this track jump pulse is prohibited and the guide track is continuously scanned by the pickup, thereby making it possible to form intermittent recording tracks.

Furthermore, during the generation period of the read command signal, the pickup 10 increases the intensity of the laser beam from the recording start end of the intermittent recording track to heat the guide track and make magneto-optical recording possible.

Furthermore, the CD-ROM encoder 5
and the CD-DA encoder 6 each require a subcode indicating an address when encoding.
This subcode is A that inputs the output of the reproduction amplifier 11.
It is generated by inputting the ATIP code decoded by the TIP decoding means 12 to the subcode generation means 8. Therefore, the recorded subcode always matches the ATIP code.

On the other hand, the disk record D is kept at a constant linear velocity (1
．． The disk motor 19, which is driven at a speed of 3 m/sec), is driven by the motor drive means 18, and its rotational speed is determined by the 22.05 KHz reference signal of the fixed oscillator 16 and the ATI
It is controlled by inputting the high frequency tracking error signal obtained from the P decoding means 12 to the phase comparison means 17 and supplying the obtained phase comparison output to the motor drive means 18.

The output of the reproduction amplifier 11 is also supplied to a tracking error detection means 14, and the tracking error signal is supplied to a tracking coil drive means 15 in the same way as the track jump pulse. The tracking drive output obtained as a result is the pickup 10.
The optical axis of the objective lens is changed to achieve tracking and track jumping.

When the read address has been updated by a predetermined amount and all data in the read area of the memory 3 has been read out, the write/read control means 4 deactivates the read command signal. As a result, in conjunction with the deactivation of the read command signal, the CD-RO
The operations of M encoder 5 and below are sequentially prohibited. Further, the track jump control means 13 latches the ATIP code at the end of recording that was last captured by the ATIP decoding means 12, and repeats the track jump at the end of recording to enter a recording standby state. Furthermore, in conjunction with the completion of recording, the pickup 10 reduces the intensity of the laser beam and enters a recording standby reproduction state.

When the write/read control means 4 completes storing the compressed audio data in the new storage area 3b, it generates a read command signal again in the manner described above, reads out the stored data continuously, and performs the next intermittent operation. Make a record.

Disc record data is recorded by repeating intermittent recording of 7.6 seconds of rest and 2.4 seconds of recording, and connecting the intermittent recording tracks along the guide track.

The disc record recorded as described above is played back by the playback device shown in FIG. The illustrated reproducing apparatus compares a high-frequency tracking error signal with a reference signal of a fixed oscillator 23 using a phase comparing means 22, and outputs the comparison output when the rotation of a disc record D is driven by a disc motor 20, similar to the recording apparatus. The rotation of the disk motor 20 is controlled by the motor drive means 21 which receives the input.

The pickup 24 also amplifies the received light output to a reproducing amplifier 25, supplies the amplified output to a tracking error detection means 26, and forms a tracking error signal.
The signal is supplied to a tracking drive means 27 for tracking correction. Further, the ATIP decoding means 28
Track jump control means 2 by detecting ATIP code
9 and a high frequency error signal to the phase comparison means 22.
is supplied to. Therefore, in the reproduction standby state, the track jump control means 29 supplies a track jump pulse to the tracking coil drive means 27 so that the same ATIP code is reproduced.

The configuration described above is common to the recording apparatus shown in FIG. 2, and in the recording/reproducing apparatus, these configuration means can be used for both recording and reproduction.

The reproduction operation specific to the reproduction apparatus will be explained below. First, a reproduction signal derived from the recording/reproducing amplifier 25 in an initial state is decoded by the CD-DA decoder 30 and further inputted to the CD-ROM decoder 31. This CD-ROM decoder 31 decodes the input data and supplies it to the storage area 33a of the memory 33, detects the link block at the end of recording with the built-in recording end detection means 32, and outputs the end detection output. It is supplied to the write/read control means 34.

The write/read control means 34 supplies a write address to the memory 33 in order to store decoded data in the storage area 33a of the memory 33 at high speed during playback, and also supplies the storage area 33a of the storage area 33a where storage has been completed. In order to sequentially read out the stored data using the reading area 33b,
A read address is continuously supplied to the memory 33. Further, the data amount detection means 35 built in the write/read control means 32 calculates the difference between the read address and the write address, and calculates the storable storage area of 350 Kbytes (data amount per unit recording track length). ) or more, a reproduction command signal is supplied to the track jump control means 29.

The track jump control means 29 prohibits the generation of track jump pulses as long as the reproduction command signal is input, and when the termination detection signal is input with the reproduction command signal deactivated, the final A track jump pulse is generated in order to continuously reproduce the ATIP code and enter a reproduction standby state at the end of reproduction. Therefore, at the start of reproduction, a plurality of units of intermittent recording tracks are continuously generated despite the generation of the end detection output.

It should be noted that when the storage area is less than 350K bytes, the recording end detection signal is detected by the write/read control means 34.
When the write address is supplied to the memory 33, the supply of the write address to the memory 33 is interrupted.

In this state, the playback device enters a playback standby state and maintains the playback standby state until a playback command signal is generated from the data amount detection means 35.

The stored data that is continuously read out is expanded by the data expansion means 36 and sent to the D/A conversion means 3.
7 and is converted into a two-channel playback stereo audio signal.

When the storage data is read out from the memory 33 and the storable area exceeds 350K bytes, a reproduction command signal is generated when one recording unit of data can be stored in the storage area 33a. Then, playback standby is released and playback is started. The reproduced signal is decoded in the manner described above and stored in the storage area 33a of the memory 33, and once the recording end detection output is generated, the apparatus enters the reproduction standby state again.

[0034] Thereafter, similarly, every time the storable area exceeds the data amount for one recording track length, intermittent playback is resumed and decoded data is stored in the storage area 33a.

Although this embodiment focuses on the storable area of the memory 33, that is, the empty area, this is completely equivalent to focusing on the storage amount, that is, the stored area, as expressed in the claims. It is.

Furthermore, in this embodiment, the recording unit of the intermittent recording track is fixed at 181 subcode frames, but the recording unit can be switched automatically or by setting as necessary. The playback device is
Disk records recorded in this way can also be played back intermittently according to the recording unit.

Furthermore, in this embodiment, the recording device and the reproducing device are separate devices, but it is of course possible to apply the present invention to the recording/reproducing device, and in that case, the memory and the writing/reproducing device can be used as separate devices.
Naturally, the read control means and the like are shared.

When sharing the memory, reading is started with less stored data than during playback, taking into account that the amount of stored data increases due to a recording error during recording, and when playing back, the amount of stored data increases due to a playback error. Taking this into consideration, it is necessary to start reading when there is more stored data than when recording.

Furthermore, in order to reduce consumption of electricity when starting recording, the compressed audio data is continuously stored while the disk motor is stopped, and the write address to the memory is set in conjunction with the recording operation. If the configuration is such that reading is started from the memorized write address or its vicinity after the disk motor is driven to a recordable state in conjunction with the recording operation, recording can be started in conjunction with the recording operation. Partial audio can be recorded without any loss. Furthermore, if there is sufficient memory capacity, it is possible to reversely record the audio signal before the recording start timing.

[0040]

[Effects of the Invention] Therefore, according to the present invention, it is possible to process completed data in order to perform intermittent reproduction on an intermittent recording track for each recording unit, and the reproduction process is reliable and easy, and the effect is great. .

[Brief explanation of drawings]

FIG. 1 is a block diagram of a reproducing circuit according to the present embodiment.

FIG. 2 is a block diagram of a recording circuit of this embodiment.

FIG. 3 is an explanatory diagram of the signal processing principle of this embodiment.

[Explanation of symbols]

D Disc record 33 Memory 35 Data amount detection means 36 Data expansion means 32 Recording end detection means 21 Motor drive means 29 Track jump control means

Claims (1)

[Claims] Claim 1: A continuous line is created by intermittently magneto-optically recording the recorded data along a spiral guide track, using recorded data in which end identification data is added to the end of a predetermined amount of compressed audio data as a recording unit. In an optical reproducing device for reproducing a disk record formed of recording tracks with a constant speed, there is provided a storage means for storing reproduced data at high speed and sequentially reading out the stored data, and a storage means for reproducing the stored data when the amount of the stored data becomes less than a certain amount. a data amount detecting means for detecting the amount of data; a decompressing means for decompressing read data of the storage means; a recording end detecting means for detecting end identification data from reproduced data; and a disc for driving the disc record at a constant linear velocity. a driving means, and a reproducing means that interrupts continuous reproducing scanning in response to the end detection output to enter a reproduction standby state, and starts reproduction from the next recording start edge in response to the output of the data amount detection means, respectively. An intermittent playback circuit for compressed audio data.