JPH0589646A - Data reproducing apparatus - Google Patents

Abstract

PURPOSE:To make the actual reproduction time of individual pieces of music equal when an introductory scanning reproduction operation is executed by means of a disk recording and reproducing apparatus used to reproduce an optical disk on which a plurality of musical data whose compressibility is different are recorded. CONSTITUTION:A musical data from a magnetooptical disk 2 is stored in a memory 22; it is expanded and read out; compressibility information is read out from, e.g. a TOC on the magnetooptical disk 2; the reproduction time from the magnetooptical disk 2 of individual pieces of music is controlled according to the compressibility information. Thereby, it is possible to realize an introductory scanning operation in which the actual reproduction time of the individual pieces of music becomes equal. Alternatively, the musical data from the magnetooptical disk 2 is stored in the memory 22; it is extended and read out; the compressibility information is read out from, e.g. the TOC on the magnetooptical disk 2; a reproduced data amount from the memory of the individual pieces of music is controlled according to the compressibility information. Thereby, it is possible to realize the introductory scanning operation in which the actual reproduction time of the individual pieces of music becomes equal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data reproducing device for reproducing an optical disc on which music information is recorded.
In particular, it relates to a data reproducing device having an introscan function.

[0002]

2. Description of the Related Art Conventionally, a so-called CD (compact disc) in which music information is recorded on an optical disc has been generally used. However, by utilizing the speed of access of the optical disc,
2. Description of the Related Art There is known an optical disk reproducing apparatus having a so-called intro scan function of sequentially reproducing only the head portion of each recorded music for several seconds.

This introscan is disclosed, for example, in Japanese Patent Laid-Open No.
As described in Japanese Patent Laid-Open No. 4-7511, the TOC (Table of.
Content) information, move the pickup to the beginning position of the song, play the recorded music information for a preset time (several seconds), then move the pickup to the beginning position of the next song, The operation of reproducing the recorded music information for the preset time is performed for each song.

By the way, the applicant of the present invention has previously described a technique for reproducing a disc in which data-compressed music information is continuously recorded on tracks of the disc, for example, Japanese Patent Application No. Hei 2-169977. It is proposed in each specification, drawings and the like of Japanese Patent Application No. 2-222821 to Japanese Patent Application No. 2-222823.

In this technique, a magneto-optical disk or the like is used as a recording medium and, for example, a so-called CD-I (CD-Intera) is used.
c)) or AD (adaptive difference) PCM audio data defined in the audio format of CD-ROM XA, or digital audio data bit-compressed and encoded according to another format. This bit-compressed digital audio data is added with a connecting sector (ringing sector) before and after, for example, every 32 sectors in consideration of interleaving with data of an adjacent sector, with a predetermined data amount as a recording unit. However, the sector is recorded continuously in a burst manner (intermittently).

Here, for example, so-called standard CD (compact disk) format (CD-DA) data, or so-called straight PCM audio data obtained by simply linearly quantizing an analog audio signal, is approximately 1 / Consider the case of bit-compressing to 4 and recording / reproducing. The reproduction time (play time) of the disc that is bit-compressed to approximately 1/4 and recorded is approximately four times as long as when the straight PCM data before compression, for example, the data in the CD-DA format is recorded. Become. This means that the recording and reproducing time of the same extent as a standard 12 cm CD can be obtained with a smaller disc, so that the device can be miniaturized. Further, by setting the (instantaneous) bit rate of recording / reproducing to be the same as that of the standard CD-DA format, the time required for actually writing to or reading from the disc is approximately Since only 1/4 is required, the remaining approximately 3/4 of the time can be allocated to so-called retries. Specifically, for example, at the time of recording data, a confirmation (verification) operation of whether or not the recording is normally performed, a rewriting operation when the recording is not normally performed, and the like, and at the time of reproduction, This is a re-reading operation or the like when the error rate of reproduced data is high. As a result, recording / reproduction can be performed more reliably even under adverse conditions in which the mechanism part vibrates due to disturbance and the focus, tracking, etc. are lost, and application to a small portable device becomes possible.

In order to record / reproduce such digital audio data bit-compressed to approximately 1/4,
A buffer memory for recording and / or reproducing compressed data is required. In this memory, compressed data is continuously written at a constant rate at the time of recording, and is read out in bursts or intermittently at a speed of about 4 times. The data amount of one time at the time of this burst read is a predetermined data amount as the recording unit, for example, 32 sectors, and as described above, several sectors for ringing before and after are added to spatially record on the disc. Is recorded continuously (following the previous recording portion). Further, at the time of reproduction, data of a predetermined recording unit (for example, 32 sectors + several sectors for ringing) is reproduced from the disc in a burst or intermittent manner at a speed approximately four times as high as the above and after, The ringing sector is removed and written to the buffer memory.
Compressed data is continuously read from the memory at the constant rate.

The recording data compression rate is not limited to one type, and several types are prepared in advance.
It is conceivable to switch the compression rate according to the content and use of the data. In this case, a plurality of data files (for example, songs) having different compression rates may be recorded in one recording medium, for example, one disc.

[0009]

However, when the above-described intro scan is performed using a disc on which a plurality of songs having different compression rates are recorded, the reading time of each song from the disc is kept constant. In such a case, there is an inconvenience that the reproduction time of the decompressed music data differs for each song. That is, for example, the first song is compressed by 1/4 (compression ratio 4), the second song is compressed by 1/2 (compression ratio 2),
When the third song is recorded with 1/8 compression (compression rate 8), if the beginning of each song is read from the disc for 2 seconds, the playback time of the expanded playback signal of each song is:
The first song is 8 seconds, the second song is 4 seconds, the third song is 16 seconds,
The second song is too short, the third one is too long.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a data reproducing apparatus having an introscan function so that the reproduction time between songs is almost always constant. To provide.

[0011]

A data reproducing apparatus according to the present invention records compressed music data and
In an optical disc reproducing apparatus for reproducing an optical disc in which head position information and compression rate information of each song are recorded at predetermined positions, reproduction position control means for moving a pickup to the head position of each song based on the head position information. Reproducing means for reproducing music data from the disc, and storage means for storing music data reproduced from the disc,
The music data read from the storage means has a data expansion means for expanding the music data according to the compression rate, and a reproduction control means for controlling a reproduction time from the disk according to the compression rate. At the end, the reproduction position control means is controlled so as to move the pickup to the beginning position of the next music piece.

A data reproducing apparatus according to the present invention is an optical disk reproducing apparatus for reproducing an optical disk in which compressed music data is recorded and head position information and compression rate information of each song are recorded at predetermined positions. Playback position control means for moving the pickup to the start position of each song based on the start position information, reproduction means for reproducing music data from the disc, and storage means for storing music data reproduced from the disc. And a data expansion means for expanding the music data read from the storage means according to the compression rate, and a reproduction control means for controlling the amount of data read from the storage means according to the compression rate. Then, at the end of reading the data according to the compression ratio, the reproduction position control means is arranged to move the pickup to the head position of the next music piece. It is characterized in that it has to be controlled.

[0013]

On the optical disk, time information and compression rate information of each music piece are recorded in the user TOC area, for example. When performing the intro-scan reproduction, the read time from the disc for each music for realizing the reproduction for the specified time is calculated from the specified time and the compression ratio of each music. By controlling the read time from the disc for each song corresponding to the read time, it is possible to realize an intro scan in which the same playing time is obtained for each song.

Further, the amount of data read from the memory 22 for each music for realizing the reproduction for the specified time is calculated from the specified time and the compression rate of each music. By controlling the amount of read data from the memory for each song in accordance with the amount of read data, it is possible to implement an intro scan with the same playing time for each song.

[0015]

EXAMPLES Examples of the present invention will be described in the following order. a. Overview of recording / reproducing device b. Specific configuration of recording / reproducing apparatus c. Description of recording system d. Description of playback system e. Introscan playback f. Basic recording / playback operation

A. 1. Outline of Recording / Reproducing Apparatus First, FIG. 1 is a block diagram showing a schematic configuration of an optical disk recording / reproducing apparatus as an embodiment of a data reproducing apparatus according to the present invention.

In FIG. 1, a recording medium such as an optical disk 2 records digital audio signals for a plurality of songs (a plurality of data files) compressed at several different bit compression rates. The recording signal is burst read by the optical head 3 for each predetermined recording unit (for example, 32 sectors + several sectors), and bit-compressed audio data is obtained through the decoder 21 for descramble and error correction decoding. This compressed data is written in a memory 22 such as a RAM (random access memory) and the memory 2
The audio signal is read from the data No. 2 at a constant data rate and reproduced through the decoder 23 for restoring (decompressing) the bit compression on the recording side.

Here, on the optical disk 2, time information and compression rate information of each song (data file) are recorded together with the digital audio data of a plurality of songs having different bit compression rates, for example, TOC (table of contents). ) Area or directory area.
Here, the time information in this case is address information indicating a start time and an end time of a tune when recording / reproducing in a standard format (for example, a CD-DA format which is a so-called standard compact disc audio format). , The playback time, which is the end time minus the start time,
The data amount recorded on the optical disk 2 is represented by standard time. Further, the compression information is information indicating a ratio of (data amount before compression) / (data amount after compression), for example, when standard straight PCM data is compressed to 1/4 data amount. The compression rate is 4. The compressed data is actually reproduced (a performance of a piece of music, so-called playback) for a time obtained by multiplying the data amount represented by the standard reproduction time by the compression rate.

The system controller 7 having a CPU (Central Processing Unit) and the like is the above-mentioned T of the optical disc 2.
By reading the time information and the compression rate information recorded in the OC area or the like, obtaining the actual reproduction time (performance time) of each song (each data file) and adding them as described above, the optical disc The actual total playback time (total playing time, total playing time) of all songs (previous file) in 2 is calculated. The calculated total reproduction time is displayed on the display unit 9 according to a key operation (for example, an operation of a time display key) on the key input operation unit 8.

In the TOC area and the like of the optical disc 2, the standard reproduction time information itself and the information of the substantial reproduction time (performance time) multiplied by the compression rate for each music are recorded. You may do it.

B. Specific Configuration of Recording / Reproducing Apparatus The specific configuration shown in FIG. 1 will be described below. A recordable and reproducible optical disc, for example, is used as the optical disc 2 which is rotated by the spindle motor 1. However, in the case of reproduction only, an aluminum reflection film type optical disk similar to a normal CD (compact disk) can be used. The optical head 3 for performing recording and / or reproduction with respect to the optical disc (for example, a magneto-optical disc) 2 is, for example, an optical source such as a laser light source such as a laser diode, a collimator lens, an objective lens, a polarization beam splitter, a cylindrical lens or the like. It is composed of a component and a photodetector having a light receiving portion of a predetermined pattern. The optical head 3 is provided at a position facing the magnetic head 4 with the magneto-optical disk 2 interposed therebetween. When recording data on the magneto-optical disk 2, a magnetic head 4 is driven by a head driving circuit 16 of a recording system to be described later to apply a modulation magnetic field according to the recording data, and the optical head 3 serves the purpose of the magneto-optical disk 2. Thermomagnetic recording is performed by a magnetic field modulation method by irradiating the track with laser light. Also, this optical head 3
Detects the reflected light of the laser light applied to the target track, and detects the tracking error by, for example, the so-called push-pull method. When reproducing data from the magneto-optical disk 2, the optical head 3 detects the focus error and the tracking error, and at the same time, detects the difference in the polarization angle (Kerr rotation angle) of the reflected light from the target track of the laser light and reproduces it. Generate a signal.

The output of the optical head 3 is supplied to the RF circuit 5. The RF circuit 5 extracts the focus error signal and the tracking error signal from the output of the optical head 3 and supplies them to the servo control circuit 6, and also binarizes the reproduction signal to supply it to a reproduction system decoder 21 described later.

The servo control circuit 6 is composed of, for example, a focus servo control circuit, a tracking servo control circuit, a spindle motor servo control circuit, a sled servo control circuit, and the like. The focus servo circuit controls the tracking of the optical system of the optical head 3 so that the focus error signal becomes zero. Further, the tracking servo control circuit controls the tracking of the optical system of the optical head 3 so that the tracking error signal becomes zero. Further, the spindle motor servo control circuit controls the spindle motor 1 so as to rotate the magneto-optical disk 2 at a predetermined rotation speed (for example, a constant linear speed). Further, the sled servo control circuit moves the optical head 3 and the magnetic head 4 to the target track position of the magneto-optical disk 2 designated by the system controller 7. The servo control circuit 6 that performs such various control operations supplies the system controller 7 with information indicating the operating state of each unit controlled by the servo control circuit 6.

A key input operation unit 8 and a display unit 9 are connected to the system controller 7. The system controller 7 controls the recording and reproducing system in an operation mode designated by the operation input information from the key input operation unit 8. Further, the system controller 7 traces the optical head 3 and the magnetic head 4 on the basis of address information (time information) in sector units reproduced from the recording track of the magneto-optical disk 2 by header time, Q data of subcode, or the like. The recording position and the reproducing position on the recording track being managed are managed. Information on the recording position or the reproducing position, information on the function selected by the key operation, and the like are displayed on the display unit 9 as necessary. Here, Table 1 shows the contents (recording format) recorded as a so-called sub-code Q channel signal in a lead-in area or TOC area on a recordable / reproducible disk such as the magneto-optical disk 2.

[Table 1]

In Table 1, the item P of P / R indicates a pre-master portion that is pre-recorded as a so-called physical pit and is not rewritable, and R indicates a recordable portion. The time information and the compression rate information are stored in a rewritable user TOC (so-called U-TOC) area,
The index is recorded in the part of N + 1 to 99. Here, N is a so-called BCD (binary coded decimal number) and takes any value from 00 to 98. It is conceivable to write the compression rate information in a so-called "zero-byte" in this U-TOC (TOC for user), and one specific example thereof is shown in Table 2.

[Table 2]

In Table 2, the so-called "zero-byte" is used.
Bit 7 (most significant bit) of is used as a flag indicating protection of overwrite (rewriting) of each music, and when this bit 7 is "0", writing is prohibited,
When it is “1”, the writing is specified. Bits 0 to 2 of this so-called "zero-byte" (lower 3 bits)
Is used to indicate information regarding the compression ratio. That is, bit 2 specifies the sampling frequency fs, bit 1 specifies the bit compression algorithm, and bit 0 specifies stereo / monaural. For bit 7, when it is "0", the standard CD-DA format sampling frequency is 44.1 kHz (or so-called CD-I or CD-R).
The standard sampling frequency of formats such as OM XA is 37.8 kHz), and when it is "1", the frequency is half that frequency. It is assumed that this sampling data is quantized with 16 bits, and the compression algorithm of bit 1 is compressed to about 4 bits which is 1/4 when "0",
It is specified that when "1", it is compressed to about 8 bits, which is 1/2. Bit 0 indicates stereo when "0" and monaural when "1". These bits 2
From each value of 0, the compression rate in each case as shown in Table 3 is obtained.

[Table 3]

As is apparent from Table 3, for example, the sampling frequency of bit 2 = "0" is standard (44.1k).
Hz or 37.8 kHz), bit 1 = "1" about 8
Bit 0 =
In the case of stereo of "0", the compression rate is the smallest and becomes "2". On the contrary, the sampling frequency of bit 2 = "1" is half (22.05 kHz or 18.5 kHz).
Then, an algorithm for compressing to about 4 bits of bit 1 = “0” is used, and when the bit 0 = “1” is monaural, the compression rate is the largest “16”. For other combinations of bit values, the compression rate is "4" or "8".

Here, the U-TOC (TO for user)
Table 4 shows a specific example of the recorded contents in C).

[Table 4]

Table 4 shows a specific example of the recorded contents of the U-TOC at the time of recording four songs on the magneto-optical disk 2, and the time information is the start time (start time).
And end time (stop time) are used. From the time information corresponding to the indexes B2 and B3, it can be seen that recording was performed up to the address position of 3 minutes 43 seconds 28 frames (blocks) in the standard reproduction time. Each information of the track, index, start time and end time in Table 4 is directly recorded and reproduced as the Q channel signal of the subcode as shown in Table 1 above. Also,
The compression rate information includes bits 0 to 0 of the so-called "zero-byte".
Based on the value of 2, it can be obtained as shown in Table 3 above. Here, the standard playback time for each song is obtained by subtracting the start time from the end time, but the compression ratio of each song is 4, the second song is 8, the second song is 8, and the third song is 8 ,
Since 4 is selected for each of the 4th songs, the value obtained by multiplying these compression ratios becomes the actual playback time (playing time, playing time) for each song. Such a calculation is performed by the system controller 7 and the total of the above-mentioned actual reproduction times for each music piece is calculated to obtain the total reproduction time (performance time). In the example of Table 4, it is 15 minutes 54 seconds 2 frames (block), and this numerical value is displayed on the display unit 9, for example.

Table 5 shows a generalized version of such actual reproduction time (performance time) calculation.

[Table 5]

In Table 5, the actual reproduction time Tp of one song is the end time Te expressed by the standard reproduction time.
It is possible to obtain Tp = k (Te−Ts) by multiplying the compression rate k of the music piece by subtracting the start time Ts from.

C. Description of Recording System Next, a recording system of the disc recording / reproducing apparatus will be described. The analog audio input signal A _IN from the input terminal 10 is passed through the low pass filter 11 to the A / D converter 12
Is being supplied to. The A / D converter 12 quantizes the analog audio signal A _IN , and the obtained digital audio signal is supplied to an encoder 13 for high efficiency encoding processing such as AD (adaptive difference) PCM. Further, a digital audio signal from the outside may be supplied to the encoder 13 via a digital input interface circuit (not shown). The digital audio PCM signal input to this encoder 13 is
This is so-called straight PCM data that has not been subjected to compression processing or the like, and as a specific example, similar to the standard CD (compact disc) format (CD-DA format), the sampling frequency is 44.1 kHz and quantized bits are used. The number is 16-bit PCM data. The input audio PCM data is output by the encoder 13 at a high bit rate of 1/2 to 1/16 in accordance with the sampling frequency, the bit compression algorithm, and the stereo / monaural combination as described above. Efficiency coding processing is performed. In the following description, the bit rate is compressed to approximately 1/4 (the above-mentioned compression rate is 4
(In the case of), an example is given, but other than this, 1/2, 1/8,
The operation is basically the same in the case of compression to a bit rate such as 1/16.

Next, in the memory 14, the writing and reading of data are controlled by the system controller 7, the bit compressed data supplied from the encoder 13 is temporarily stored, and is recorded on the disk as needed. It is used as a buffer memory of. That is,
For example, in the data compression mode where the compression rate is 4,
Compressed data of a constant bit rate, which is reduced to approximately 1/4 of the data transfer rate (bit rate) of the standard CD-DA format, is continuously written in the memory 14. When this compressed data is recorded on the magneto-optical disc 2, it is recorded in a burst or discrete manner at the same data transfer rate under the same disc rotation speed (constant linear velocity) as the standard CD-DA format. There is. That is, the time during which a signal is actually recorded in the recording mode is approximately 1/4 of the whole, and the remaining 3/4 time is a rest period during which no recording is performed. However, on the magneto-optical disk 2, the next recording is performed following the area recorded immediately before the rest period, and continuous recording is performed on the medium surface. This allows, for example, a standard CD-DA
The same recording density and recording pattern as the format will be recorded.

Therefore, a standard CD is read from the memory 14.
Compressed data is read in a burst at a bit rate according to the data transfer rate of the DA format, and the read compressed data is an encoder for performing interleave processing, error correction coding processing, EFM modulation processing, and the like. 15 are supplied. Here, in the data string supplied from the memory 14 to the encoder 15, one cluster consisting of a predetermined plurality of sectors (for example, 32 sectors) is a unit to be continuously recorded in one recording, and when this is subjected to encoding processing. , And the data amount for one class is added with several sectors for cluster connection. The sector for cluster connection is set longer than the interleave length in the encoder 15 so that the data of other clusters will not be affected even if interleaved.

Details of the recording in cluster units will be described later with reference to FIG. The encoder 15
The recording data supplied in bursts from the memory 14 as described above is subjected to error correction encoding processing (parity addition and interleave processing) and EFM encoding processing. Further, a synchronization pattern and a so-called sub-coding portion are also added at the same time, and the time information as described with the above Tables 1 to 4 is added to the Q channel of sub-coding in the U-TOC (TOC for user) area. And compression rate information is recorded. The recording data encoded by the encoder 15 is supplied to the magnetic head drive circuit 16. This magnetic head drive circuit 16
The magnetic head 4 is connected, and the magnetic head 4 is driven so as to apply the modulation magnetic field according to the recording data to the optical disc 2.

Further, the system controller 7 controls the memory 14 as described above, and continuously records the recording data burst-read from the memory 14 on the recording track of the magneto-optical disk 2 by this memory control. The recording position is controlled as described above. The recording position is controlled by controlling the recording position of the recording data read in burst from the memory 14 by the system controller 7 and servo-controlling a control signal designating the recording position on the recording track of the magneto-optical disk 2. Circuit 6
It is done by supplying to.

D. Description of Playback System Next, the playback system of the disc recording / playback apparatus will be described. This reproducing system is for reproducing the recording data continuously recorded on the recording track of the magneto-optical disk 2 by the above-mentioned recording system, and the recording track of the magneto-optical disk 2 is laser-lighted by the optical head 3. The recording signal is read from the magneto-optical disk 2 by tracing with. Here, the magneto-optical disk 2 is the standard C described above.
It is rotationally driven at the same rotation speed (constant linear velocity) as the D-DA format, and the recording signal is read in bursts (discretely) at the same data transfer rate as the CD-DA format, and is binary by the RF amplifier 5. Decoder 2
1 is supplied.

The decoder 21 corresponds to the encoder 15 in the recording system described above, and performs decoding processing for deinterleaving processing and error correction processing on the reproduction output binarized by the RF circuit 5. By performing processing such as EFM demodulation processing, compressed data having a compression rate of 4 is output in a burst at the same data transfer rate as the standard CD-DA format. In addition, the above U-TCO
The time information (start time, end time) is directly based on the signal of the Q channel of the subcode in the (user TOC) area, and bits 0 to 2 of the so-called "zero-byte" are used.
From the above, the compression rate information is obtained. The reproduction data obtained by the decoder 21 is supplied to the memory 22, and the subcode information and the like are supplied to the system controller 7.

In the memory 22, writing and reading of data are controlled by the system controller 7, and reproduction data which is supplied in burst from the decoder 21 at the same data transfer rate as the standard CD-DA format is written. Further, the memory 22 stores the reproduction data written in bursts at a constant bit rate, that is, approximately 1 / th of the standard CD-DA format.
The data is continuously read at the data transfer rate of 4.

The system controller 7 performs memory control for writing / reading reproduction data to / from the memory 22 and records the reproduction data burst-written from the memory 22 on the magneto-optical disk 2 by this memory control. The playback position is controlled so that playback is continued from the track. The reproduction position is controlled by managing the reproduction position of the reproduction data which is burst-read from the memory 22 by the system controller 7 and transmitting a control signal for designating the reproduction position on the recording track of the magneto-optical disk 2 to the servo circuit 6. It is done by supplying to.

Compressed data obtained as reproduced data continuously read from the memory 22 at a transfer rate (bit rate) of about 1/4 of the standard is supplied to the decoder 23. The decoder 23 corresponds to the encoder 13 of the recording system, and reproduces 16-bit digital audio data by, for example, decompressing (1/4) the compressed data of 1/4 (bit expansion).
The digital audio data from the decoder 23 is supplied to the D / A converter 24.

The D / A converter 24 converts the digital audio data supplied from the decoder 23 into an analog signal and outputs the analog audio output signal A _OUT from the output terminal 26 via the low pass filter 25.

By the way, it is desirable that the magneto-optical disk 2 used in the disk recording / reproducing apparatus has a capacity capable of recording a stereo audio signal for 60 minutes to 74 minutes. For example, a data compression rate of 4 is adopted. At this time, about 130 MB is required. In order to construct a portable or pocket-sized recording and / or reproducing apparatus, it is desirable to use a disk having an outer diameter of 8 cm or a smaller diameter. Further, regarding the track pitch and the linear velocity, the same track pitch as CD, about 1.6 μm, and the linear velocity 1.2 to 1.
4 m / s is desirable. As a disk satisfying these conditions, for example, the disc outer diameter is 64 mm, the data recordable area outer diameter is 61 mm, the data recordable area inner diameter is 31 mm, and the lead-in area inner diameter is 2 mm.
It may be 9 mm and the center hole diameter is 11 mm. If this disc is housed in a disc caddy having a length and width of 70 mm × 74 mm and supplied to the market, recording / reproducing can be performed on the disc by a reproducing device having a pocket size.

E. Intro Scan Reproduction Next, intro scan reproduction in this disc recording / reproducing apparatus will be described. In such a disc recording / reproducing apparatus, introscan reproduction is performed as follows. In the intro-scan reproduction, only the head portion of each song recorded on the magneto-optical disc 2 is sequentially reproduced for a predetermined time.

As described above, in this disc recording / reproducing apparatus, the digital audio signals for a plurality of songs compressed at several different bit compression rates are output from the magneto-optical disc 2.
Can be recorded in the optical head 3
The read compressed data is written in the memory 22 in a burst by every predetermined recording unit by
The audio signal is reproduced by reading data at a constant data rate. For example, in the data compression mode with a compression rate of 4, compressed data of a constant bit rate in which the data transfer rate of the standard CD-DA format is reduced to about 1/4 is recorded on the magneto-optical disk 2. Therefore, the actual reproduction time of a music piece having a compression rate of 4 is four times the reproduction time of data from the magneto-optical disk 2.
Since this disc recording / reproducing apparatus can record a plurality of data having different compression rates in the same disc, if the reproducing time from the magneto-optical disc 2 is made constant during introscan reproduction, The actual playback time of the song may be different.

Therefore, in this disc recording / reproducing apparatus,
In the first example, each song of the magneto-optical disk 2 for realizing a specified intro scan is performed by using the compression rate information obtained from bits 0 to 2 of so-called "zero bytes" in the U-TOC area described above. The introscan reproduction in which the reproduction time of each music piece is constant is realized by obtaining the reproduction time of the music piece and controlling so that the data of each music piece of the magneto-optical disk 2 is read out for the calculated time.

That is, the reading time T _D from the disc for each music for performing the intro-scan reproduction for the designated time T _A is obtained by T _D = T _A / K K: compression ratio. For example, when the data of each music piece is recorded at the compression rate as shown in Table 6, the read time of each music piece 01, 02, 03, 04 of the magneto-optical disk 2 is 1 second from the above formula. If it is set to 1/2 second, 1/2 second, and 1 second, the intro reproduction time of all songs will be equal to 4 seconds.
That is, since the music number 01 has a compression rate of 4, when data is read from the magneto-optical disk 1 for 1 second, reproduction is performed for 4 seconds. Moreover, since the song number 02 has a compression rate of 8, when the data is read from the magneto-optical disk 1 for 1/2 second, it becomes 4
Playback is performed for a second. Since the song number 03 has a compression ratio of 8, when data is read from the magneto-optical disk 1 for 1/2 second, reproduction is performed for 4 seconds. Since the song number 04 has a compression rate of 4, when data is read from the magneto-optical disk 1 for 1 second, reproduction is performed for 4 seconds.

[Table 6]

FIG. 3 shows an example of control when the intro scan is performed in this way. First, the song number N is (N =
1) (step 101), the optical head 3 and the magnetic head 4 are accessed to the position of the head track of the (N = 1) tune (step 102). And (N = 1)
The music data of the song is reproduced (step 103). The reproduction time obtained for the reproduction time of this (N = 1) song is
It is judged whether or not the time T _D obtained by the above equation (T _D = T _A / K) has been reached (step 104), and the reproduction time T
The playback of the (N = 1) song is continued until the _D is reached.
When the playback time from the disc reaches T _D (N = 1)
The reproduction of the music piece is ended, and the music piece number N to be reproduced is incremented (step 105). And step 101
Then, the position of the (N = 2) th song is accessed (step 102) and the (N = 2) th song is reproduced (step 103). Then, it is judged whether or not the reproduction time of the (N + 2) th song has reached T _D (step 10
4) Until the reproduction time T _D is reached, the reproduction of the (N = 2) th song is continued. When the playback time from the disc reaches T _D , the playback of the (N = 2) th song is finished and the song number N to be played is incremented (step 10).
5). Thereafter, intro scan reproduction of the third and fourth songs is continued in the same manner.

FIG. 4 shows another example of control when performing introscan reproduction. In this example, bits 0 to 2 of the so-called "zero byte" of the U-TOC area described above are used.
Using the compression rate information obtained from, calculate the amount of data required to realize the specified intro scan,
By controlling the data to be read from the memory 22 by the obtained data amount, the introscan reproduction in which the reproduction time of each music is constant is realized.

That is, assuming that the data amount for performing the introscan reproduction for the designated time is D _A , the memory 2 for each music piece required to realize the designated introscan.
The data amount D _M of the read data from 2 is obtained by D _M = D _A / K K: compression rate. By controlling the data amount of each piece of data read from the memory 22 so as to be the data amount D _M obtained in this way, it is possible to realize intro-scan reproduction with a fixed reproduction time for each piece of music.

In FIG. 4, first, the music number N is (N = 1).
(Step 201), the optical head 3 and the magnetic head 4 are accessed to the position of the head track of the (N = 1) song (step 202). Then, the music data of the (N = 1) piece of music is reproduced (step 203). It is determined whether or not the data amount of the (N = 1) music piece read from the memory 22 has reached the data amount D _M obtained by the above equation (D _M = D _A / K) (step 204), and the memory 21
The reproduction of the (N = 1) piece of music is continued until the amount of data from D reaches D _M. When the amount of data from the memory 22 reaches D _M , the reading of the data from the memory 22 is stopped (step 205), the memory 22 is cleared (step 206), and the music number N to be reproduced is incremented (step 207). .. Then, return to step 201,
(N = 2) The position of the tune is accessed (step 20
2) Then, reproduction is started (step 203). And
(N = 2) The read data amount of the memory 22 of the music piece is D _M
Is judged (step 204), and the reproduction of the second music is continued until the amount of data from the memory 22 reaches D _M. When the data amount of the memory 22 reaches D _M , the reading of the data of the memory 22 is stopped (step 205) and the memory 22 is cleared (step 20).
6) The music number N to be reproduced is incremented (step 207). Thereafter, intro scan reproduction of the third and fourth songs is continued in the same manner.

F. Basic Recording / Reproducing Operation Next, a basic recording / reproducing operation by the recording / reproducing apparatus as described above will be described. First, the recording data (data read from the memory 14) is clustered for every fixed number (for example, 32) of sectors (or blocks), and some sectors for cluster connection are provided between these clusters. It has been arranged. Specifically, as shown in FIG. 2, the class C is composed of 32 sectors (blocks) B0 to B31, and 4 sectors (for ringing) sector L1 are provided between each cluster C.
.About.L4 are arranged and connected to the adjacent sector. Here, one cluster, for example, when recording k-th cluster C _k, the 32 sectors B of this cluster C _k
Not only 0 to B31, but three sectors in the front and one sector in the rear for connection, that is, two sectors L2 and L3 for run-in block and one for sub data on the cluster C _k-1 side Recording is performed in a total of 36 sectors including the sector L4 and the sector L1. At this time, the recording data of these 36 sectors is stored in the memory 1
4 is sent to the encoder 15, and the interleave processing is performed by the encoder 15.
Although the distances of the frames (corresponding to about 1.1 sectors) are rearranged, regarding the data in the cluster C _k ,
It is well within the range of the ringing sectors L1 to L4 and does not affect other clusters C _k-1 and C _{k + 1} . The sectors L1 to L3 are provided with dummy data such as 0 and the sector L4 is provided with auxiliary sub-data, so that adverse effects on the original data due to the interleave processing can be avoided. Here, in the main data sectors B0 to B31, as shown in FIG. 5A, 0000 0000 in 8-bit binary system (two-digit hexadecimal number)
Sector numbers of (00H) to 0001 1111 (1FH) are assigned to the sector L1 of the ringing portion, and 0010 0000
(20H), L2 to L4 are 0011 1101 (3DH) to 00
11 Sector numbers of 1111 (3FH) are assigned respectively.
Further, as the cluster, for example, 36 sectors including the ringing sector may be set as one cluster.

[Table 7]

Such a ringing sector is required for facilitating burst recording or overwrite recording. However, when all tracks are continuously recorded on the disc, it is practical. Is not necessary when a commercially available read-only soft disk is created, and adjacent data clusters C may be directly connected (without a ringing sector) as shown in FIG. 5B. In this case, the data cluster and the recording cluster are equal to 32 sectors.

Table 7 shows the head trace time per physical sector or cluster actually recorded on the magneto-optical disk 2. This table 7 is shown in FIG.
The value calculated corresponding to B is shown, and each time becomes slightly longer when the ringing sector is added as described above. There are various other possible definitions of compression ratio,
It's a little different.

By performing such recording on a cluster-by-cluster basis, there is no need to consider mutual interference due to interleaving with other clusters, and data processing is greatly simplified. Also, if the recorded data could not be recorded normally during recording due to defocus, tracking error, or other malfunctions, rerecording could be performed in units of the above classes, and if effective data reading could not be performed during playback. , Re-reading can be done in cluster units.

By the way, one sector (block) has 235
It consists of 2 bytes, 12 bytes for synchronization from the beginning, 4 bytes for header, and data D0001 to D2336 23
36 bytes are arranged in this order. Of the 12 bytes for synchronization in the sector structure (block structure), the first 1 byte is 00H (H indicates a hexadecimal number), 10 bytes of FFH are continued, and the last 1 byte is 00H. The next 4-byte header consists of the minute, second, and block address portions, one byte each, followed by one byte for mode information. This mode information is
This is mainly for showing the mode of the CD-ROM, and the internal structure of the sector shown in FIG. 2 corresponds to the mode 2 of the CD-ROM format. CD-I is a standard using this mode 2.

The specific example of FIG. 2 further shows a format for recording compressed audio data.
From the head of the 336-byte area, an 8-byte sub-header, sound groups SG01 to SG18 of 18 groups each having 128 bytes, a 20-byte space area, and a 4-byte reserve area are arranged in this order. 8 above
The byte sub-header is formed by repeating a file number, a channel number, a sub mode, and a data type of 1 byte each twice.

By the way, when data having such a sector structure is recorded on the disk, encoding processing including parity addition and interleaving processing is performed by the encoder 15, and EFM (8-14 modulation) processing is performed. Given,
Recording is performed in a recording format as shown in FIG.

In FIG. 6, one block (one sector) consists of 98 frames from the first frame to the 98th frame, and one frame is a channel clock cycle T.
588 times (588T), 24T within one frame
(+ Connection bit 3T) frame synchronization pattern part, 1
4T (+ connection bit 3T) subcode portion, and 54
4T data (audio data and parity data)
Parts are provided. The data portion of 544T is 12
Byte (12 symbols) audio data, 4 bytes parity data, 12 bytes audio data, and 4 bytes parity data are so-called EFM modulated, and audio data in one frame is 24 bytes (that is, audio samples). 1 word of data is 1
Since it is 6 bits, it is 12 words). The sub-code portion is EFM-modulated 8-bit sub-code data, and is divided into blocks of 98 frames, and each bit constitutes eight sub-code channels P to W. However, the subcode portions of the first and second frames have block synchronization patterns S ₀ and S ₁ out of the rule of EFM (out-of-rule), and each subcode channel P to W is from the third frame to the third frame. Each of up to 98 frames has 96 bits.

Although the above audio data is interleaved and recorded, it is deinterleaved at the time of reproduction to be audio data having a data array in a time sequence. Instead of this audio data, general CD-I data or the like can be recorded.

In the disc recording / reproducing apparatus shown in FIG. 1, the system controller 7 continuously increments the write pointer W of the memory 14 at a speed corresponding to the compressed data bit rate as shown in FIG. When the unread data amount of the compressed data stored in the memory 14 is continuously written and becomes a predetermined amount M _k or more, the read pointer R of the memory 14 is transferred according to the standard CD-DA format. It is incremented in a burst manner at a speed and a predetermined recording unit (for example, 32
Memory control is performed so that the data is read every sector. Accordingly, within memory 14, the data amount that can be written without destroying the non-read data, that is, the recording capacity is possible will be prevented below a predetermined amount (M _T -M _K).

Here, the recording data read out from the memory 14 in a burst is continuous on the upper recording track of the magneto-optical disk 2 by controlling the recording position on the recording track of the magneto-optical disk 2 by the system controller 7. Can be recorded in the state. Moreover, as described above, since the memory 14 is always secured with a data write area of a predetermined amount or more, the system controller 7 detects that a track jump or the like has occurred due to disturbance or the like, and the recording operation to the magneto-optical disk 2 is performed. Even if the operation is interrupted, the recovery operation can be performed during that time, and the input data can be continuously recorded on the recording track of the magneto-optical disk 2.

Next, in the reproducing system of the disc recording / reproducing apparatus of FIG. 1, the system controller 7 sets the write pointer W of the memory 22 to a standard CD as shown in FIG.
-Increment at a transfer rate according to the DA format and write in bursts, and the read pointer R of the memory 22 is continuously incremented and read at a rate according to the bit rate of the compressed data, and the write pointer W reads the read. When the pointer R is caught up (the writable area becomes 0), the writing is stopped, and the writing is performed when the unread data amount stored in the memory 22 becomes a predetermined amount M _L or less. Performs memory control. Therefore, a predetermined amount M _L is always stored in the memory 222.
It is possible to continuously read the reproduction data from the memory 22 while securing the above unread area.

The reproduction data written in a burst in the memory 22 can be reproduced in a continuous state on the recording tracks of the magneto-optical disk 2 by the system controller 7. Moreover, since always a predetermined amount M _L or more data read area in the memory 22 as described above is secured, with respect to the optical disk 2 to detect that the track jump or the like occurs due to disturbances such as the system controller 7 Even when the reproduction operation is interrupted, it is possible to read the reproduction data from the data reading area of the predetermined amount M _L or more and continue the output of the analog audio signal.

By the way, in the system for recording the compressed audio data of the small-diameter magneto-optical disk 2 as described above, the information of the wobbling component when the so-called pre-groove is previously cut on the magneto-optical disk 2 before recording. To record the absolute time information (A
(IPT: Absolute Time In Pregroove) is considered, and several formats have been proposed for how to enter time information in this AIPT and how to put time information in the so-called header time part. .. However, in the above-mentioned small-diameter disk system, the address on the disk and the address of the sector are the so-called conventional C
It is not preferable for time correction or display because not only is there no merit in inserting in time (minutes, seconds, frames) like D, but also because the ringing area as described above is required. Therefore, for example, the compression ratio is determined as shown in Table 6 above, and each sector number is assigned to each cluster as shown in Table 3 above, and the sector number is assigned to the data portion for actually reproducing the audio signal. 8-bit binary number (2-digit hexadecimal number), 0000 0000 (00
H) to 0001 1111 (1FH). In that sense, since only sector data having the same sector number is sent to the memory 22, whether it is a read-only disc using an aluminum reflective film or a recordable disc using a magneto-optical recording medium film, etc., it is based on this sector number. If the processing for displaying and the processing for displaying the total time are performed, the processing can be standardized. The actual playing time may be displayed by detecting the compression ratio information, calculating the sum of products of the values in Table 6 and the number of sectors or the number of clusters, and displaying the sum.

The present invention is not limited to the above-mentioned embodiments, and the present invention can be applied not only to a recording / reproducing apparatus for an optical disk but also to a reproduction-only apparatus. The time information recorded on the recording medium is not limited to the above-mentioned start time and end time, and the reproduction time and the actual performance time are not limited to U.
It may be written in the -TOC area. Further, an address may be recorded on the recording medium instead of the time information, and in that case, the reproduced address may be converted into the time information. Also, the time information and compression information are
In addition to using the subcode Q channel signal, the subcode Q channel signal may be written in, for example, the header portion or subheader portion in one sector of FIG. 2, or the U-TO of the read area of the disc.
You may make it write in parts other than C, etc. Further, the intro scan does not have to be sequentially performed from the first tune, and the intro scan can be performed in a desired order by inputting an arbitrary order and controlling by the system controller.

[0067]

According to the present invention, the time information and the compression rate information of each song are recorded on the optical disc in the user TOC area, for example, and when the introscan reproduction is performed, the specified time and the compression rate of each song are recorded. From this, the read time from the disc for each song for realizing the reproduction of the designated time is calculated. By controlling the read time from the disc for each music corresponding to this read time, it is possible to realize introscan reproduction in which the same playing time is obtained for each music.

Further, in the present invention, the amount of read data from the memory for each song for realizing the playback of the designated time is calculated from the designated time and the compression ratio of each song, and the amount of read data is calculated according to the read data amount. By controlling the amount of data read from the memory for each song, it is possible to realize introscan reproduction with the same playing time for each song.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a disc recording / reproducing apparatus as an example of a data reproducing apparatus according to the present invention.

FIG. 2 is a diagram showing a format of a cluster structure which is a recording unit on a recording medium.

FIG. 3 is a diagram showing the contents of each sector of the cluster structure of FIG.

FIG. 4 is a flowchart used for explaining an example of an introscan reproduction operation in the disc recording / reproduction device according to the present invention.

FIG. 5 is a flowchart used for explaining another example of the introscan reproduction operation in the disk recording / reproduction device according to the present invention.

FIG. 6 is a diagram showing formats of frames and sectors (blocks) in the so-called CD (Compact Disc) standard.

FIG. 7 is a diagram showing a state of a memory-controlled memory in the recording system of the disc recording / reproducing apparatus according to the present invention.

FIG. 8 is a diagram showing a state of a memory-controlled memory in a reproducing system of the disk recording / reproducing apparatus according to the present invention.

[Explanation of symbols]

 2 magneto-optical disk 3 optical head 7 system controller 13 data compression encoder 14, 22 memory 15 encoder 16 magnetic head drive circuit 21 decoder 23 data expansion decoder

Claims (3)

[Claims] 1. An optical disk reproducing apparatus for reproducing an optical disk in which compressed music data is recorded and head position information and compression rate information of each song are recorded at predetermined positions, based on the head position information. The playback position control means for moving the pickup to the head position of each song, the playback means for playing the music data from the disc, the storage means for storing the music data played from the disc, and the reading means for reading from the storage means. It has a data decompression means for decompressing the outputted music data according to the compression rate and a reproduction control means for controlling the reproduction time from the disc according to the compression rate. A disc reproducing apparatus, characterized in that the reproducing position controlling means is controlled so as to move a pickup to a head position of a music piece. 2. An optical disk reproducing apparatus for reproducing an optical disk in which compressed music data is recorded, and head position information and compression rate information of each song are recorded at predetermined positions, based on the head position information. The playback position control means for moving the pickup to the head position of each song, the playback means for playing the music data from the disc, the storage means for storing the music data played from the disc, and the reading means for reading from the storage means. It has data decompression means for decompressing the outputted music data according to the compression rate, and reproduction control means for controlling the amount of data read from the storage means according to the compression rate. Control of the reproduction position control means so as to move the pickup to the beginning position of the next song at the end of reading the data. A characteristic optical disc reproducing apparatus. 3. The optical disk reproducing apparatus according to claim 2, further comprising: clearing the data stored in the storage means at the end of reading the data according to the compression rate.