JP2002197842A - Recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily and rapidly obtain the total reproducing time of all data files of a recording medium recorded with the plural data files varying in data compression rates. SOLUTION: The recording medium is provided with a data region where the plural data files varying in the data compression rates are recorded and a catalog management region where track number information corresponding to the respective data files, address information indicating recording positions and data compression rate information of the respective data files are recorded. The total reproducing time of all of the data files recorded at the recording medium can be determined simply by reading out the address information and data compression rate information of the catalog management region.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording medium on which a plurality of data files are recorded.

[0002]

2. Description of the Related Art The applicant of the present invention has previously disclosed a technique for compressing an input digital audio signal into bits and recording the digital audio signal in a burst with a predetermined data amount as a recording unit, for example, as disclosed in Japanese Patent Application No. 2-169977. , Japanese Patent Application No. 2-2136
4, Japanese Patent Application No. 2-221365, Japanese Patent Application No. 2-2228
No. 21 to Japanese Patent Application No. 2-222823 are proposed in each specification and drawings.

[0003] This technique uses a magneto-optical disk or the like as a recording medium and uses, for example, AD (adaptive difference) PCM audio data defined in the audio data format of a so-called CD-I (CD-interactive) or CD-ROM XA. Alternatively, digital audio data bit-compressed and encoded according to another format is recorded and reproduced. This bit-compressed digital audio data has a predetermined data amount as a recording unit, and
For example, for every 32 sectors, a connecting sector (linking sector) is added before and after in consideration of interleaving with data of an adjacent sector, and the sector is recorded continuously in a burst (intermittent) manner. .

Here, for example, a so-called straight PC which is obtained by simply linearly quantizing data of a standard CD (compact disk) format (CD-DA format) or an analog audio signal.
Consider a case in which M audio data is recorded and reproduced with approximately 1/4 bit compression. The playback time (play time) of the disc recorded with the bit compression of approximately 1/4 is approximately four times that of recording the straight PCM data before compression, for example, the data of the CD-DA format. Become. This is the standard one for smaller discs
Since the same recording and reproduction time as that of a 2 cm CD can be obtained, the size of the apparatus can be reduced. Also, the (instantaneous) bit rate of recording / reproduction is set to the standard CD-D
By using the same format as the A format, the time required for actually performing recording and reproduction can be reduced to approximately 1/4, so that the remaining approximately 3/4 time can be allocated to so-called retries. it can. Specifically, for example, at the time of data recording, a confirmation (verify) operation of whether or not recording was normally performed, a rewrite operation at the time of not successfully performing recording, and the like.
This is a re-read operation when the error rate of reproduced data is high. Accordingly, recording and reproduction can be performed more reliably even under bad conditions in which the mechanical unit vibrates due to disturbance and focus, tracking, and the like are lost, and application to a small portable device becomes possible.

[0005] In order to record and reproduce such digital audio data that has been bit-compressed by approximately 1/4,
A buffer memory for recording and / or reproducing compressed data is required. In this memory, during recording, compressed data is continuously written at a constant rate, and is read out in bursts or intermittently at approximately four times the speed. One data amount at the time of this burst reading is a predetermined data amount serving as the recording unit, for example, 32 sectors. As described above, several sectors for linking are added before and after, and spatially on the disk. It is recorded continuously (following the previous recording part). At the time of reproduction, the data of the data amount of the predetermined recording unit (for example, 32 sectors + several sectors for linking) is reproduced from the disk at a speed of about 4 times in a burst or intermittent manner. Are written to the buffer memory. The compressed data is continuously read from the memory at the constant rate.

[0006]

Incidentally, the compression ratio of the recording data is not limited to one type, but several types are prepared in advance, and the compression ratio is determined according to the contents and use of the data. May be switched. In this case 1
A plurality of data files (for example, songs) having different compression rates may be recorded on one recording medium, for example, one disk.

As described above, for example, when a plurality of music pieces having different compression ratios are mixedly recorded on one disk, for example, the reproduction time of the music piece cannot be obtained only from the information of the data amount. In particular, it is difficult to obtain a total (all songs) playback time.

The present invention has been made in view of such circumstances. Even if a plurality of data files (songs and the like) having different compression ratios coexist on a recording medium such as a disc, the total time (all songs) can be obtained. Reproduction time) can be easily obtained.

[0009]

A recording medium according to the present invention has a data area in which a plurality of data files having different compression ratios are recorded, track number information corresponding to each data file, and recording of each data file. The above-described problem is solved by having address information indicating a position and a catalog management area in which compression ratio information of each data file is recorded.

Here, as a specific example, when an optical disk is used as the recording medium, and one music file of the digital audio signal is made to correspond to one data file, music pieces having different compression rates are mixed in one optical disk. In addition, time information as an address and compression ratio information are recorded for each music piece. In this case, the time information as an address is information indicating a start time (start time) and an end time (stop time) of the music, and the reproduction time as a data amount of the music is obtained by subtracting the start time from the end time. Can be requested. The actual playback time (playing time) of each song can be obtained by multiplying the playback time as the data amount of each song by the compression rate, and by taking the total playing time of each song, You can find the playing time of all songs. In this case, the inventory management area may be a TOC (table of contents) area, a directory area, a lead-in area, or a user TOC area.
(So-called U-TOC) region.

[0011]

According to the present invention, the total time information of all data files in the recording medium, especially the decompression, is based on the track number information, the address information indicating the recording position, and the compression ratio information of each data file recorded in the inventory management area of the recording medium. It is possible to calculate the total reproduction time information for the data obtained by the processing.

[0012]

FIG. 1 is a block circuit diagram showing a schematic configuration of an optical disk recording / reproducing apparatus using an optical disk as an example of a recording medium according to the present invention.

In FIG. 1, on a recording medium such as the optical disk 2, digital audio signals for a plurality of music pieces (a plurality of data files) compressed at several different bit compression rates are recorded. This recording signal is transmitted to the optical head 3
Thus, burst reading is performed for each predetermined recording unit (for example, 32 sectors + several sectors), and bit-compressed audio data is obtained via a decoder 21 for descrambling and error correction decoding. The compressed data is written into a memory 22 such as a RAM (random access memory), read out from the memory 22 at a constant data rate, and passed through a decoder 23 for restoring (expanding) bit compression on the recording side. Perform playback.

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

The system controller 7 having a CPU (Central Processing Processor) and the like
By reading the time information and the compression ratio information recorded in the OC area and the like, obtaining the actual reproduction time (playing time) for each music (each data file) as described above, and adding these, the optical disc is obtained. The actual total playback time (total playing time, total playing time) of all the songs (all files) in 2 is calculated. The calculated total playback time is displayed on the display unit 9 in accordance with a key operation (for example, an operation of a time display key) on the key input operation unit 8 or the like.

In the TOC area and the like of the optical disk 2, the standard reproduction time information itself, information on substantial reproduction time (performance time) obtained by multiplying each music by a compression ratio, and the like are recorded. You may put it.

Hereinafter, the specific configuration shown in FIG. 1 will be described in detail. As the optical disk 2 driven to rotate by the spindle motor 1, a recordable, for example, a magneto-optical disk is used. However, in the case of playback only,
An aluminum reflective film type optical disk similar to a normal CD (compact disk) can also be used. An optical head 3 for performing recording and / or reproduction on the optical disk (for example, a magneto-optical disk) 2 includes, for example,
Laser light sources such as laser diodes, collimator lenses,
The optical system includes optical components such as an objective lens, a polarizing beam splitter, and a cylindrical lens, and a photodetector having a light receiving portion having a predetermined pattern. The optical head 3 is provided at a position facing the magnetic head 4 via the magneto-optical disk 2. When data is recorded on the magneto-optical disk 2, the magnetic head 4 is driven by a recording-system head drive circuit 16, which will be described later, to apply a modulation magnetic field according to the recorded data. By irradiating the track with laser light, thermomagnetic recording is performed by a magnetic field modulation method. The optical head 3 detects reflected light of the laser beam applied to the target track, detects a focus error by, for example, a so-called astigmatism method, and detects a tracking error by, for example, a 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 of the laser light from the target track and reproduces the data. Generate a signal.

The output of the optical head 3 is supplied to an 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 the focus error signal and the tracking error signal to the servo control circuit 6 and binarizes the reproduction signal and supplies it to a reproduction system decoder 21 described later. .

The servo control circuit 6 comprises, for example, a focus servo control circuit, a tracking servo control circuit, a spindle motor servo control circuit, a thread servo control circuit and the like. The focus servo control circuit performs focus control of the optical system of the optical head 3 so that the focus error signal becomes zero. Further, the tracking servo control circuit performs tracking control 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 thread servo control circuit moves the optical head 3 and the magnetic head 4 to target track positions of the magneto-optical disk 2 designated by the system controller 7. The servo control circuit 6 that performs such various control operations supplies information indicating the operation state of each unit controlled by the servo control circuit 6 to the system controller 7.

A key input operation unit 8 and a display unit 9 are connected to the system controller 7. The system controller 7 controls a recording system and a reproduction system in an operation mode specified by operation input information from the key input operation unit 8. The system controller 7 controls the magneto-optical disk 2
Based on address information (time information) in sector units reproduced from the recording track by a header time, Q data of a subcode, and the like, the recording position on the recording track traced by the optical head 3 and the magnetic head 4, Manage playback position. The display unit 9 displays information on the recording position or the reproduction position, information on the function selected by the key operation, and the like as necessary. Here, Table 1 shows contents (recording format) recorded as a so-called subcode Q channel signal in a lead-in area or TOC area on a recordable / reproducible disk such as the magneto-optical disk 2.
Is shown.

[0021]

[Table 1]

In Table 1, P in the item of P / R is:
A so-called mechanical pit indicates a pre-master portion pre-recorded and formed in a non-rewritable manner, and R indicates a recordable portion. The time information and the compression ratio information related to the embodiment of the present invention include the user TOC (so-called UT).
In the OC) area, the index is recorded in a portion from N + 1 to 99. Here, N is a so-called BCD (Binary Decimal Number) and takes any value from 00 to 98. It is conceivable to write the above-mentioned compression ratio information in a so-called "zero-byte" in the U-TOC (TOC for user). A specific example is shown in Table 2.

[0023]

[Table 2]

In Table 2, bit 7 (most significant bit) of a so-called "zero-byte" is used as a flag indicating overwrite (rewrite) protection for each music piece, and this bit 7 is set to "0". Is defined as writing prohibited, and "1" is defined as writing permitted.
Bits 0 to 2 (lower 3 bits) of this so-called “zero-byte” are used to indicate information on 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. When bit 7 is "0", the sampling frequency of the standard CD-DA format is 44.1 kHz (or the standard sampling frequency of the so-called CD-I or CD-ROM / XA format is 37.8 kHz). )age,
When "1", the frequency is half that frequency. This sampling data is quantized by 16 bits, and the compression algorithm of bit 1 is that when "0" is compressed to about 4 bits of 1/4, and when "1", it is compressed to about 8 bits of 1/2. Stipulates that it be compressed. Bit 0 indicates “stereo” when “0” and monaural when “1”. From the values of these bits 2 to 0, the compression ratio in each case as shown in Table 3 is obtained.

[0025]

[Table 3]

As apparent from Table 3, for example, the sampling frequency of bit 2 = "0" is the standard (44.1k
Hz or 37.8 kHz), an algorithm for compressing to about 8 bits of bit 1 = “1” is used, and in the case of stereo of bit 0 = “0”, the compression ratio is the smallest and becomes “2”. Conversely, when the sampling frequency of bit 2 = “1” is half (22.55 kHz or 18.9 kHz), bit 1 =
An algorithm for compressing to about 4 bits of “0” is used, and when the bit 0 = “1” monaural, the compression rate is the largest and becomes “16”. For other combinations of bit values, the compression ratio is "4" or "8".

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

[0028]

[Table 4]

Table 4 shows a specific example of the recorded contents of the U-TOC at the time when four pieces of music are recorded on the magneto-optical disk 2. The time information includes a start time (start time) and an end time ( Stop time). From the time information corresponding to the indexes B2 and B3, it can be seen that the recording has been 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. The compression ratio information can be obtained as shown in Table 3 based on the values of bits 0 to 2 of the so-called “zero-byte”. Here, the standard reproduction time for each song is obtained by subtracting the start time from the end time of each song, and the compression ratio for each song is 4 for the first song, 8 for the second song, and 8 for the third song. Since 8 and 4 are selected for the fourth and fourth songs, respectively, the values obtained by multiplying these compression ratios become the actual reproduction time (playing time, playing time) for each song. Such calculations are performed by the system controller 7, and the total playback time (performance time) can be obtained by taking the total of the actual playback time for each song. In the example of Table 4, the time 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 calculation of the actual reproduction time (performance time).

[0030]

[Table 5]

In Table 5, the actual reproduction time Tp of one song is the end time Te expressed by the standard reproduction time.
By subtracting the start time Ts from the above, and multiplying the result by the compression ratio k of the music, it can be obtained as Tp = k (Te-Ts).

Next, the recording system of the disk recording / reproducing apparatus will be described.

The analog audio input signal _{A IN} from the input terminal 10 is supplied to the A / D converter 12 through a low-pass filter 11. A / D converter 12 quantizes the analog audio input signal A _IN, a digital audio signal obtained, for example AD (adaptive differential)
It is supplied to an encoder 13 for high-efficiency encoding processing such as PCM. Further, an external digital audio signal may be supplied to the encoder 13 via a digital input interface circuit (not shown). The digital audio PCM signal input to the encoder 13 is so-called straight PCM data that has not been subjected to compression processing or the like, and as a specific example, a standard CD (compact disk) format (CD
-DA format), the sampling frequency is 44.1 kHz and the number of quantization bits is 16 bits.
Data. The input audio PCM data is processed by the encoder 13 to have a high bit rate of 1/2 to 1/16 according to the sampling frequency, the bit compression algorithm, and the combination of stereo / monaural as described above. An efficiency compression encoding process is performed. In the following description, an example of compressing to a bit rate of approximately 1/4 (when the above-described compression ratio is 4) is given.
In addition, the basic operation is the same in the case of compression to a bit rate of 1/2, 1/8, 1/16 or the like.

The memory 14 is controlled by the system controller 7 to write and read data. The memory 14 temporarily stores bit-compressed data supplied from the encoder 13, and records the bit-compressed data on a disk as necessary. Is used as a buffer memory. That is, in the data compression mode in which the compression ratio is 4, for example, compressed data of a constant bit rate reduced to approximately 1/4 of the data transfer rate (bit rate) of the standard CD-DA format is stored in the memory 14. Written continuously.
When recording this compressed data on the magneto-optical disk 2,
The data is recorded in a burst or discrete manner at the same data transfer speed under the same disk rotation speed (constant linear speed) as the standard CD-DA format. That is, the time during which the signal is actually recorded in the recording mode is approximately 1/4 of the whole, and the remaining 3/4 time is a pause 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 pause period, and continuous recording is performed on the medium surface. Thereby, for example, a standard CD-DA
Recording of the same recording density and storage pattern as the format is performed.

Therefore, the compressed data is read from the memory 14 in a burst at a bit rate corresponding to the data transfer rate of the standard CD-DA format.
The read compressed data is supplied to an encoder 15 for performing an interleaving process, an error correction coding process, an EFM modulation process, and the like. Here, in the data string supplied from the memory 14 to the encoder 15, one cluster composed of a predetermined plurality of sectors (for example, 32 sectors) is a unit that is continuously recorded in one recording, and when this is encoded, The data amount is obtained by adding several sectors for cluster connection to the data amount for one cluster. The cluster connection sector is set to be longer than the interleave length in the encoder 15 so that even if interleaved, data in other clusters is not affected.

The details of the recording in cluster units will be described later with reference to FIG.

The encoder 15 converts the recording data supplied in bursts from the memory 14 as described above.
Encoding processing (parity addition and interleaving processing) for error correction, EFM encoding processing, and the like are performed. Also,
The addition of a synchronization pattern and a so-called sub-coding portion is also performed at the same time, and the Q channel of the sub-coding portion in the U-TOC (TOC for user) region is provided with the above Table
Time information and compression ratio information described with Table 4 are recorded. The recording data that has been subjected to the encoding process by the encoder 15 is supplied to the magnetic head drive circuit 16. The magnetic head drive circuit 16 is connected to the magnetic head 4 and drives the magnetic head 4 so as to apply a modulation magnetic field corresponding to the recording data to the magneto-optical disk 2.

The system controller 7 performs the above-described memory control on the memory 14 and continuously records the recording data read out from the memory 14 in a burst on the recording track of the magneto-optical disk 2 by the memory control. The recording position is controlled so that The recording position is controlled by controlling the recording position of the recording data read out from the memory 14 in a burst manner by the system controller 7 and transmitting a control signal designating the recording position on the recording track of the magneto-optical disk 2 to a servo control circuit. 6
Is performed by supplying the

Next, a reproducing system of the disk recording / reproducing apparatus will be described.

This reproducing system is for reproducing the recording data continuously recorded on the recording tracks of the magneto-optical disk 2 by the above-mentioned recording system. Is traced by a laser beam, whereby a recording signal is read from the magneto-optical disk 2. Here, the magneto-optical disk 2 is rotationally driven at the same rotational speed (constant linear velocity) as the standard CD-DA format, and is burst-like (discrete) at the same data transfer speed as the CD-DA format. The read signal is read by the RF amplifier circuit 5, binarized by the RF amplifier circuit 5, and supplied to the decoder 21.

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

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

The system controller 7 performs a memory control of writing / reading of the reproduction data to / from the memory 22 and, by the memory control, the reproduction data written in a burst from the memory 22 to the magneto-optical disk 2. The playback position is controlled so as to continuously play back from the recording track. The reproduction position is controlled by controlling the reproduction position of the reproduction data read in a burst from the memory 22 by the system controller 7 and transmitting a control signal designating the reproduction position on the recording track of the magneto-optical disk 2 to a servo control circuit. 6.

Compressed data obtained as reproduced data continuously read from the memory 22 at a transfer rate (bit rate) of approximately 1/4 of the standard is supplied to a decoder 23. The decoder 23 corresponds to the encoder 13 of the recording system. For example, the decoder 23 expands the compressed data of 1/4 by, for example, 4 times (bit expansion) to obtain 1 data.
6-bit digital audio data is reproduced. The digital audio data from the decoder 23 is
It 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 an analog audio output signal _AOUT from an output terminal 26 via a low-pass filter 25.

Incidentally, it is desirable that the magneto-optical disk 2 used in such a disk recording / reproducing apparatus has a capacity capable of recording a stereo audio signal for about 60 minutes to about 74 minutes.
, About 130 Mbytes are required.
In addition, a portable or pocket-sized record and / or
Or, in order to configure a reproducing apparatus, the outer diameter of the disc is 8c.
It is desirable to use a disk of m or smaller diameter. Further, the track pitch and the linear velocity are the same as those of the CD, ie, the track pitch is 1.6 μm and the linear velocity is 1.
It is desired to be 2 to 1.4 m / s. As a disk satisfying these conditions, for example, a disk having an outer diameter of 6
4 mm, the outer diameter of the data recording area is 61 mm, the inner diameter of the data recording area is 32 mm, the inner diameter of the lead-in area is 30 mm,
The center hole diameter may be 10 mm. If this disc is stored in a disc caddy measuring 70 mm × 74 mm in length and width and supplied to the market, recording and reproduction on the disc can be performed by a recording / reproducing apparatus having a pocket size. The range of the inner and outer diameters of the data recording area of the disc for enabling recording and reproduction for about 72 to 76 minutes in the data compression mode with the compression ratio of 4 is as follows.
The diameter may be appropriately set within a range from an outer diameter of 60 mm to 62 mm when the inner diameter is 32 mm to an outer diameter of 71 mm to 73 mm when the inner diameter is 50 mm.

Next, the basic recording / reproducing operation by the disk recording / reproducing apparatus as described above will be described in further detail.

First, the recording data (read from the memory 14)
Data) is a fixed number (for example, 32) of sectors
(Or blocks).
Several sectors for cluster connection are arranged between rasters
It is in the form that was. Specifically, as shown in FIG.
Cluster C consists of 32 sectors (blocks) B0-B31
And each of these clusters C has four
Sectors L1 to L4 for connection (for linking) are
Connected to the raster. Where one cluster, example
For example, the k-th cluster C_k If you want to record
Cluster C_k Not only the 32 sectors B0 to B31,
3 sectors forward, 1 sector backward, connecting sector
Cluster C_k-1 2 for run-in block on the side
Sectors L2 and L3 and one sector L4 for sub data
And cluster C_{k + 1} Side run-out block
A total of 36 sectors including one sector L1
I try to keep a record. At this time, these 36
Data from the memory 14 to the encoder 15
The encoder 15 performs an interleave process.
As a result, up to 108 frames (about 1.1 sections)
Are sorted), but the above class
TA C_k The data in
It is well within the range of Kuta L1 ~ L4, other classes
TA C_k-1 And C _{k + 1} Has no effect on
Note that, for example, dummy data such as 0 is allocated to the sectors L1 to L3.
The auxiliary sub data is allocated to sector L4.
Of the original data due to the interleave processing.
The effect can be avoided. Here, the main data sector B0
To B31 are 8-bit binary numbers as shown in FIG.
(2 digits hexadecimal number) 0000 0000 (00H) to 0001 11
11 (1FH) sector numbers are assigned, and Linkin
0010 0000 (20H) for the sector L1 in the logging section, and L2 to L4
Is the section from 0011 1101 (3DH) to 0011 1111 (3FH).
Data numbers. Also, with the above cluster
For example, 36 sectors including linking sectors
May be regarded as one cluster.

Such a linking sector is necessary for facilitating burst recording or overwrite recording. However, when recording all tracks continuously on a disk, specific examples are given below. Is unnecessary when creating a commercially available read-only software disc. For example, FIG.
B, adjacent data clusters C may be directly connected (without linking sectors). In this case, both the data cluster and the recording cluster have 32 sectors.

Table 6 shows the head trace time per physical sector or cluster actually recorded on the magneto-optical disk 2. Table 6 shows the values calculated corresponding to B in FIG. 3 described above. When the linking sector is added as described above, each time is slightly longer. It should be noted that various other definitions of the compression ratio are conceivable, and the values slightly change.

[0051]

[Table 6]

By performing such recording in cluster units, it is not necessary to consider mutual interference due to interleaving with other clusters, and data processing is greatly simplified. Also, if the recording data cannot be recorded normally at the time of recording due to defocus, tracking deviation, other malfunction, etc., re-recording can be performed in cluster units, and if effective data reading cannot be performed during reproduction, Re-reading can be performed in cluster units.

Incidentally, one sector (block) is 235.
23 bytes consisting of 2 bytes, 12 bytes for synchronization, 4 bytes for header, and data D0001 to D2336 from the beginning.
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), followed by 10 bytes of FFH, and the last 1 byte is 00H. The next 4-byte header is composed of one byte for mode information, following the minute, second, and block address portions of one byte each. This mode information is mainly for indicating 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 beginning of the 2336-byte area, an 8-byte sub-header, 128 bytes each, and 18 groups of sound groups SG01 to SG01 are provided. SG18, a 20-byte space area, and a 4-byte reserved area are arranged in this order. 8 above
The byte subheader has a file number, a channel number, a submode, and a data type of 1 byte, which are arranged twice.

When such sector-structured data is recorded on a disk, the encoder 15 performs an encoding process including a parity addition and an interleave process, and performs an EFM (8-14 modulation) process. FIG. 4
Recording is performed in a recording format as shown in FIG.

In FIG. 4, one block (one sector) is composed of 98 frames from the first frame to the 98th frame, and one frame has a channel clock period T
588 times (588T) of the frame synchronization pattern part of 24T (+3 connection bits) in one frame, 14T
A (+ connection bit 3T) subcode portion and a 544T data (audio data and parity data) portion are provided. The data portion of 544T is so-called EFM-modulated 12-byte (12-symbol) audio data, 4-byte parity data, 12-byte audio data, and 4-byte parity data, and audio data in one frame. Is 24 bytes (that is, one word of audio sample data is 16 bytes).
12 words). The sub-code part is obtained by subjecting 8-bit sub-code data to EFM modulation, and is divided into blocks of 98 frames, and each bit forms eight sub-code channels P to W. However, the subcode portions of the first and second frames are block synchronization patterns S _{0 and} S ₁ outside the rules of the EFM modulation (out-of-rule), and the subcode channels P to W are shifted from the third frame to the third frame. It is 96 bits each for up to 98 frames.

The above audio data is recorded after being subjected to an interleaving process. During reproduction, the audio data is subjected to a deinterleaving process so as to be audio data having a data arrangement according to a time order. Instead of this audio data,
General CD-I data and the like can be recorded.

In the disk 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 bit rate of the compressed data as shown in FIG. continuously writing Te, the unread data volume of the compressed data stored in the memory 14 becomes equal to or larger than a predetermined amount M _K, pursuant read pointer R of the memory 14 in the standard CD-DA format The memory control is performed such that the data is incremented in a burst at the transfer speed and read out in predetermined recording units (for example, 32 sectors). Therefore, in the memory 14, the data amount that can be written without destroying the unread data, that is, the recordable capacity is:
It will be prevented below a predetermined amount _(M T -M _K).

Here, the recording data read in bursts from the memory 14 is continuous on the recording tracks of the magneto-optical disk 2 by controlling the recording position on the recording tracks of the magneto-optical disk 2 by the system controller 7. The status can be recorded. Further, as described above, since a data write area of a predetermined amount or more is always secured in the memory 14, the system controller 7 detects that a track jump or the like has occurred due to disturbance or the like, and performs a recording operation on the magneto-optical disk 2. Even when the recording is interrupted, the input data is continuously written in the recordable area of the predetermined amount or more, and the return processing operation can be performed during that time, and the input data is continuously recorded on the recording track of the magneto-optical disk 2. The status can be recorded.

Next, in the reproducing system of the disk recording / reproducing apparatus shown in FIG. 1, the system controller 7 sets the write pointer W of the memory 22 to a standard CD as shown in FIG.
-While incrementing at a transfer rate in accordance with the DA format and writing in a burst, the read pointer R of the memory 22 is continuously incremented and read at a rate corresponding to the bit rate of the compressed data. It stops writing when caught up with the read pointer R (writable area becomes zero), so that the unread data amount stored in the memory 22 writes the equal to or less than a predetermined amount M _L Perform memory control. Accordingly, while ensuring a data read area always a predetermined amount M _L or more unread data volume in the memory 22 can be read continuously reproduced data from the memory 22.

The reproduction data written in a burst to the memory 22 is reproduced in a continuous state on the recording track of the magneto-optical disk 2 by controlling the reproduction position on the recording track of the magneto-optical disk 2 by the system controller 7. can do. 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 interrupting playback operation, it is possible to continue the output of the analog audio signal by reading the playback data from the predetermined amount M _L or more data read area, it is possible to perform the return processing operations in the meantime.

In a system in which compressed audio data is recorded on the small-diameter magneto-optical disk 2 as described above, information on a wobbling component when a so-called pre-groove is previously cut on the magneto-optical disk 2 before recording. Recording absolute time information (ATIP: Absolute Time Implement Groove) has been considered, and the method of inserting time information in this ATIP, the method of inserting time information into a so-called header time portion, and the like are considered. That format has been proposed. However, in the above-described small-diameter disk system, there is not much merit even if the address on the disk or the address of the sector is entered in time (minute, second, frame) as in a conventional so-called CD or the like. Since such a linking area is required, it is not preferable for time correction and display. Therefore, for example, when the compression ratio is determined as shown in Table 6 above and each sector number is assigned to each cluster as shown in FIG. 3, the data portion for actually reproducing the audio signal has the above-mentioned sector number. 8-bit binary number (2 hexadecimal digits), 0000 0000
(00H) to 0001 1111 (1FH) are recorded only in the sector. In that sense, only the sector data having the same sector number is sent to the memory 22 regardless of whether the disk is a read-only disk using an aluminum reflective film or a recordable disk using a magneto-optical recording medium film. If processing for display or processing for total time display is performed, the processing can be shared. The actual playing time may be displayed by detecting the compression rate information, calculating the product sum of the values in Table 6 above and the number of sectors or clusters, and displaying the result.

The present invention is not limited to the above embodiment. For example, the time information recorded on the recording medium is not limited to the start time and the end time, but may be the reproduction time or the actual time. The performance time may be written in the U-TOC area or the like. In addition to the time information and the compression ratio information, in addition to using the Q channel signal of the subcode,
For example, the data may be written in a header portion, a subheader portion, or the like in one sector in FIG. 2, or may be written in a portion other than the U-TOC of the disk lead-in area.

[0064]

As is apparent from the above description, according to the recording medium of the present invention, the data area in which a plurality of data files having different compression rates are recorded, and the track number information corresponding to each of the data files And a list management area in which address information indicating the recording position of each data file and the compression ratio information of each data file are recorded. Therefore, a track for each data file recorded in the list management area is provided. Calculating total time information of all data files in a recording medium, in particular, total reproduction time information of data obtained by decompression processing, based on number information, address information indicating a recording position, and compression ratio information. Can be.

Here, an optical disk is used as the recording medium, and a digital audio signal 1
When associating music pieces, music pieces having different compression rates are mixedly recorded on one optical disc, and time information and compression rate information as addresses are recorded for each music piece. In this case, the time information as an address is information indicating a start time (start time) and an end time (stop time) of the music, and the reproduction time as a data amount of the music is obtained by subtracting the start time from the end time. Can be requested. The actual playback time (playing time) of each song can be obtained by multiplying the playback time as the data amount of each song by the compression rate, and by taking the total playing time of each song, You can find the playing time of all songs.

[Brief description of the drawings]

FIG. 1 is a block circuit diagram showing a configuration example of a disk recording / reproducing apparatus using an example of a recording medium according to the present invention.

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

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

FIG. 4 is a diagram showing a format of a frame and a sector (block) in the standard of a so-called CD (compact disk).

FIG. 5 is a diagram showing a state of a memory whose memory is controlled in a recording system of the disk recording / reproducing apparatus.

FIG. 6 is a diagram showing a state of a memory whose memory is controlled in a reproducing system of the disk recording / reproducing apparatus.

[Explanation of symbols]

2 magneto-optical disk, 3 optical head, 7 system controller, 8 key input operation unit, 9 display unit,
13 data compression encoder, 14, 22 memory, 15 encoder, 16 magnetic head drive circuit, 21 decoder, 23 data expansion decoder

Claims (1)

[Claims] 1. A data area in which a plurality of data files having different compression ratios are recorded, track number information corresponding to each data file, address information indicating a recording position of each data file, and compression of each data file. A list management area in which rate information is recorded.