JPH0877719A - Optical disk recording or reproducing method, optical disk recording or reproducing device and optical disk - Google Patents

Abstract

PURPOSE: To reproduce identification codes without change thereof to other codes at the time of discontinuous reproduction of data strings by adding dummy data in such a manner that the number of bits of data strings exclusive of the identification codes between the continuously appearing codes from the one identification code attains the multiple of the identification codes. CONSTITUTION: A video bit stream 101 encodes with high efficiency is inputted to an input terminal 101. The digital data strings are sequence start codes consisting of 32 bits. A detecting circuit 102 executes detection of the identification codes of 32 bits, removes the identification codes from the data strings and outputs only the identification codes to a counter circuit 103 and a multiplexer 105 and the data strings subjected to removal the identification codes to the counter circuit 103 and the multiplexer 105. The circuit 103 counts the number of the bits in the data strings and puts the total number of the number of the bits between the identification codes to a dummy data generating circuit 104. The circuit 104 divides the number of the input bits by the 32 bits and adds the dummy data of only the number of the bits obtd. by subtracting the remainder from 32 when the data is not the multiple of the 32 bits. The data is then recorded via a modulator 107.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk recording method and apparatus for recording a digital data string on an optical disk in sector units on a logical format composed of an ID section and a data section.

[0002]

2. Description of the Related Art As a device for recording / reproducing a digital data string on an optical disc, those shown in FIGS. 5 and 6 are generally known. FIG. 5 is a block diagram on the recording side, and FIG. 6 is a block diagram on the reproducing side.

In FIG. 5, 106 is an error detection / correction code addition circuit for adding parity for error detection / correction to a digital data sequence, and 107 is a digital data sequence to which an error detection / correction code has been added. A modulator for converting to a data string, a recording amplifier 108,
Reference numeral 109 is a recording head, and 110 is an optical disk.

Further, in FIG. 6, reference numeral 601 denotes a reproducing head for reproducing the signal recorded on the optical disk 110, and 602.
Is a reproduction amplifier, 603 is a demodulator, and 604 is an error detection / correction code addition circuit 106 based on the demodulated digital data sequence.
This is an error detection / correction circuit that removes the parity added by and corrects the data when an error is detected.

In FIG. 5, a serial digital data string is input to the input terminal 501. This data string is added with a parity for error correction by the error detection / correction code adding circuit 106, digitally modulated by EFM or the like by the modulator 107, and after a fixed length ID part is added for each sector. The recording head 1 is amplified by the recording amplifier 108.
The data is recorded on the optical disk 110 via sector 09 in sector units. The above is the operation on the recording side.

On the reproducing side, as shown in FIG. 6, a digital data string read from the optical disk 110 through the reproducing head 601 in sector units is amplified by a reproducing amplifier 602 and then demodulated by a demodulator 603. Detect the
The data in the data section is demodulated. Error detection / correction circuit 60
Reference numeral 4 detects a parity for error correction from the demodulated digital data, removes the parity, and corrects the error in the digital data when an error is detected by the syndrome operation. This digital data string is output from the output terminal 605.

[0007]

However, in the conventional configuration as described above, a digital data string including M (M is a natural number of 2 or more) kinds of identification codes composed of N (N is a natural number) bits is handled. In this case, there is no problem with normal recording / reproduction, but if the digital data string is reproduced discontinuously in sector units by special reproduction or the like, it is determined that an N-bit identification code exists across sectors. There is a serious problem that a discontinuity point occurs on the way, and the identification code is garbled into another identification code having a different meaning.

For example, taking a start code composed of 32 bits of an ISO / IEC11172 standard video bit stream as an M type of identification code composed of N bits as an example, this digital data string is divided into sector units in a logical format. A state of recording is schematically shown in FIG. In FIG. 7, the data length is shown in bytes for the sake of simplicity. In FIG. 7, hatched portions are identification codes (1) to (5) composed of 32 bits, only the identification code (1) is a picture start code (hexadecimal notation 00000100), and the identification code ( 2) to (5) are slice start codes (hexadecimal notation 0000101 to 0000104). Furthermore,
The identification code (2) is recorded with 3 bytes (hexadecimal expression 000001) at the end of sector 1 and 1 byte (hexadecimal expression 01) at the beginning of sector 2. Normally, sectors 1, 2, and 3 are reproduced in this order, but when special reproduction is performed in the order of sectors 1 and 3, the data indicated by the alternate long and short dash line is discontinuously reproduced, and slice start codes (hexadecimal notation) are reproduced. At 00000101)
Is the picture start code (0000 in hexadecimal notation)
0100), and the identification code may be garbled.

In view of the above point, the present invention provides an optical disc recording method and apparatus in which an identification code is not transformed into another identification code when a digital data string is discontinuously reproduced in sector units by special reproduction or the like. The purpose is to

[0010]

In order to achieve the above object, the present invention counts the number of bits of a digital data string other than an identification code which starts between at least one identification code and which appears consecutively. Then, the dummy data is added so that this becomes a multiple of the identification code length, and the dummy data is recorded in the data portion of the sector on the logical format.

In order to achieve the above object, the present invention starts with at least one identification code, and uses an identification code start signal and bit number information of a digital data string,
When the identification code is divided into multiple sectors, dummy data is added before the identification code so that the identification code starts from the beginning of the sector data and recorded in the data part of the sector on the logical format. It is a composition.

[0012]

According to the present invention, the identification code does not become another identification code even if the digital data string is discontinuously reproduced sector by sector due to the special reproduction or the like.

[0013]

【Example】

(Embodiment 1) Hereinafter, Embodiment 1 of the present invention will be described with reference to the drawings. 1 is a block diagram of an optical disk recording method and apparatus according to a first embodiment of the present invention.

In FIG. 1, blocks having the same numbers as those shown in FIG. 5 operate similarly to the conventional example. Reference numeral 102 denotes an identification code detection circuit that detects and removes a 32-bit identification code from the digital data string, and 103 is reset for each identification code, and the number of bits of digital data other than the identification code existing between the two identification codes. Is a bit number counting circuit, 104 is a dummy data generating circuit for generating dummy data, and 105 is a time division multiplexer for time division multiplexing an identification code, a digital data string other than the identification code, and dummy data. In this example,
The length of the data part in one sector on the logical format will be described as 2048 bytes.

The operation will be described in detail with reference to FIG.
For example, ISO / IEC11172 is used as the input terminal 101.
A video bitstream highly efficient coded according to the standard is input. At this time, the first input digital data string is a sequence start code composed of 32 bits. This digital data string is input to the identification code detection circuit 102. Identification code detection circuit 10
2 detects a 32-bit identification code,
The identification code is also removed from the digital data string, only the identification code is sent to the bit number counting circuit 103 and the time division multiplexer 105, and the digital data string from which the identification code is removed is sent to the bit number counting circuit 103. Output to the time division multiplexer 105.

The bit number counting circuit 103 is reset for each identification code detected by the identification code detection circuit 102, counts the number of bits of the digital data sequence other than the identification code existing between the identification codes, and outputs the identification code. The total number of bits existing between the dummy data generation circuit 10
4 is output. The dummy data generation circuit 104 divides the number of bits input from the bit number counting circuit 103 by 32 bits to obtain the remainder. When the remainder is not 0, that is, when the total number of bits existing between the identification codes is not a multiple of 32 bits, dummy data corresponding to the number of bits obtained by subtracting the remainder from 32 is generated.

Therefore, the maximum dummy data length is 31 bits. The time-division multiplexer 105 time-division multiplexes the identification code, the digital data string other than the identification code, and the dummy data, and sets 32 bits as the minimum unit.
A data portion in a sector on the logical format having a doubled length of 2048 bytes is configured. An error detection / correction code addition circuit 1 for this sector data for one sector
06 adds a parity for error detection and correction and outputs it to the modulator 107. The subsequent processing is the same as in the conventional example.

Regarding the structure at the time of reproduction, the digital data is read out in sector units and realized by the same structure as the conventional example shown in FIG. 6, but at least one identification code is selected from the sector data in the logical format. It has an identification code detector (not shown) for detecting, and various processes are performed according to the detection result.

FIG. 2 schematically shows a digital data string recorded in sector units on the logical format by the above operation on the recording side. In FIG. 2, the data length is shown in bytes for the sake of simplicity. The shaded area in Figure 2 is an identification code consisting of 4 bytes.
(1) to (5). The number of bits of the digital data string existing between the identification code (1) and the identification code (2) is 2041 bytes. When divided by 4 bytes, the remainder becomes 1 byte, so add 3 bytes of dummy data. Sector 1
Is composed.

Similarly, 1 is included in the 999-byte digital data string existing between the identification code (2) and the identification code (3).
Byte dummy data, identification code (3) and identification code
Sector 2 is formed by adding 3-byte dummy data to the 1037-byte digital data string existing between (4). For sector 3, the number of bits in the digital data string between the identification codes is divisible by 4 bytes,
No dummy data is added. Therefore, in FIG. 7, the identification code (2) is recorded over the sector 1 and the sector 2, whereas in FIG. 3, the identification code (2 ) Will only exist in sector 2.

The start code composed of 4 bytes of the ISO / IEC11172 standard video bit stream has a common first 3 bytes, and the remaining 1 byte has various meanings. If the start code is discontinuous within the first 3 bytes, it will be garbled to a different start code.
However, by recording on the optical disc with the configuration as described above, the video bit stream existing in one sector is recorded with the identification code length as a unit as shown in FIG. 1
One start code does not play discontinuously.

In the present embodiment, the length of the sector data is 2048 bytes, but this may be any multiple of the identification code length. Further, if the identification code is always the beginning of the sector data, the identification code can always be detected at the beginning of the sector, which simplifies the reproduction process.

(Embodiment 2) Since the optical disk recording method and apparatus according to Embodiment 1 of the present invention is configured to judge and insert dummy data every time an identification code is detected, it is possible to insert dummy data in sector units in a logical format. In the digital data string recorded in, dummy data may be inserted everywhere. If the amount of data between the identification codes becomes very short, the ratio of the substantial amount of information to be recorded to the recording capacity may decrease, that is, the recording efficiency may significantly decrease. In a second embodiment of the present invention, an optical disk recording method and apparatus for solving this problem will be described with reference to the drawings.

FIG. 3 is a block diagram of an optical disk recording method and apparatus according to the second embodiment of the present invention. In FIG. 3, blocks having the same numbers as those shown in FIG. 5 operate similarly to the conventional example. 302 is 3 out of the digital data string
An identification code detection circuit that detects a 2-bit identification code and generates a start signal thereof, 303 is a bit number counting circuit that is reset in sector length units, and counts the number of bits of an input digital data string, and 304 is an identification code Of the digital data string and a dummy data generation circuit for generating a predetermined amount of dummy data calculated from the number of bits in a sector of the digital data string. 306 is a time-division multiplexer for time-division multiplexing the digital data string and dummy data. In this embodiment, the length of the data part in one sector on the logical format is 16384 bits (2048 bytes).

The operation will be described in detail with reference to FIG.
The input terminal 301 is, for example, ISO / IEC11172
A video bitstream highly efficient coded according to the standard is input. This digital data string is input to the identification code detection circuit 302, the bit number counting circuit 303, and the time base multiplexer 306. Identification code detection circuit 3
02 detects a 32-bit identification code and outputs its start signal to the dummy data generation circuit 304.

The bit number counting circuit 303 includes a coincidence detector 3
The number of bits of the digital data string which is reset by the reset signal generated for each sector length 16384 bits by 05 is counted, and the value is output to the dummy data generation circuit 304 and the coincidence detector 305. In the dummy data generation circuit 304, the value input from the bit number counting circuit when the identification code start signal is input is 1 from 16354 (= 16384-32 + 2) bits.
If it is between 6384 bits, dummy data for the number of bits obtained by subtracting the value from 16385 is generated and output to the time axis multiplexer 306.

The time axis multiplexer 306 multiplexes the input digital data sequence and dummy data in a time division manner to make 32 bits the minimum unit, which is 512 times 2048.
A data part in a sector on a logical format having a byte length is configured. The subsequent processing is the same as in the first embodiment. The configuration at the time of reproduction is the same as that of the first embodiment of the present invention.

FIG. 4 schematically shows a digital data string recorded in units of sectors on the logical format by the above operation on the recording side. In FIG. 4, the data length is shown in bytes for the sake of simplicity. The shaded area in Fig. 4 is an identification code consisting of 4 bytes.
(1) to (5). At the start of the identification code (2), the value output from the bit number counting circuit 303 becomes 16361 bits, which is between 16354 bits and 16384 bits, so that dummy data for 24 bits is inserted. At the start of the identification codes (3), (4), and (5), the value output from the bit number counting circuit 203 is 8025 bits, 16
353 bits and 8001 bits, and 16354
Since it is not between the bit and 16384 bits, no dummy data is generated. Therefore, in FIG.
It is possible to reduce the generation of dummy data for bytes and prevent the identification code (2) from being recorded over the sectors 1 and 2.

In this embodiment, the sector data length is 2048 bytes, but this may be anything. Further, if the identification code is always the beginning of the sector data, the identification code can always be detected at the beginning of the sector, which simplifies the reproduction process.

[0030]

As described above, according to the present invention, the number of bits of the digital data string other than the identification code existing between the identification codes that continuously appear, starting with at least one identification code, is the identification code length. Since dummy data is added so as to be a multiple and recorded in the data part within one sector in the logical format, one identification code is not recorded across sectors and is reproduced discontinuously in sector units. However, the identification code is not transformed into another identification code having a different meaning, and the malfunction of the reproduction process can be prevented.

Further, when the identification code is divided into a plurality of sectors using the identification code start signal and the bit number information of the digital data string, the identification code starts before the identification code. Since the identification code is recorded in the data portion of the sector on the logical format by adding the dummy data so that it starts from the beginning of the sector data, not only the above effect can be obtained,
Further, the amount of dummy data can be minimized and the recording efficiency can be improved.

[Brief description of drawings]

FIG. 1 is a block diagram of an optical disc recording method and device according to a first embodiment of the present invention.

FIG. 2 is a schematic diagram of a digital data string recorded in sector units on a logical format according to the first embodiment of the present invention.

FIG. 3 is a block diagram of an optical disc recording method and device according to a second embodiment of the present invention.

FIG. 4 is a schematic diagram of a digital data string recorded in sector units on a logical format according to a second embodiment of the present invention.

FIG. 5 is a recording side block diagram of a conventional optical disc recording method and apparatus.

FIG. 6 is a reproduction side block diagram of a conventional optical disc recording method and apparatus.

FIG. 7 is a schematic diagram of a digital data string recorded in sector units on a logical format according to a conventional example.

[Explanation of symbols]

 102 identification code detection circuit 103 bit number counting circuit 104 dummy data generation circuit 105 time base multiplexer 106 error detection and correction code addition circuit 107 modulator 108 recording amplifier 109 recording head 110 optical disk 302 identification code detection circuit 303 bit number counting circuit 304 dummy data generation circuit 305 coincidence detector 306 time base multiplexer

Claims (12)

[Claims] 1. An M comprising N (N is a natural number) bits.
(M is a natural number of 2 or more) In an apparatus for recording a digital data string including identification codes of various types on an optical disk in sector units on a logical format composed of an ID section including address information and a data section, an identification code of 1 And a bit number counting means for counting the number of bits of the digital data sequence other than the identification code existing between the identification code 2 appearing first in the digital data sequence following the identification code 1 and the bit number counting means. The number of obtained bits L is N
If it is not a multiple of, dummy data of the number of bits corresponding to the value obtained by subtracting the remainder obtained by dividing L by N is inserted into the data before the identification code 2 so as to be a multiple. An optical disc recording apparatus, comprising: a dummy data inserting unit for recording the digital data string obtained by the dummy data inserting unit in a data section in one sector. 2. M composed of N (N is a natural number) bits
A method for recording a digital data string including (M is a natural number of 2 or more) kinds of identification codes on an optical disk in sector units in a logical format composed of an ID section including address information and a data section. If the number L of bits of the digital data string consisting of codes other than the identification code existing between the code 1 and the identification code 2 appearing first in the digital data string following the identification code 1 is not a multiple of N, it becomes a multiple. As described above, the dummy data having the number of bits corresponding to the value obtained by subtracting the remainder obtained by dividing the L by N with respect to the data before the identification code 2 is inserted and recorded in the data part in the sector. An optical disk recording method characterized by the above. 3. M composed of N (N is a natural number) bits
An apparatus for recording a digital data string including identification codes (where M is a natural number of 2 or more) on an optical disk in sector units in a logical format including an ID section including address information and a data section, wherein N bits Means for detecting M types of identification codes and generating a start signal thereof, and a bit number counting means for counting the number of bits B bits of the digital data string with the sector length K bits being the maximum value, When the number of bits B when the code start signal is generated changes from (K−N + 2) to K, (K−B +
1) Dummy data inserting means for inserting dummy data of bits into a digital data string when the identification code start signal is generated, and a digital data string obtained by the dummy data inserting means is recorded in a data part within one sector. An optical disk recording device characterized by the above. 4. M composed of N (N is a natural number) bits
A method of recording a digital data string including (M is a natural number of 2 or more) kinds of identification codes on an optical disc in sector units in a logical format composed of an ID portion including address information and a data portion, While detecting M kinds of identification codes consisting of N bits, the number of bits B bits of the digital data string is counted with the sector length K bits as the maximum value, and the number of bits at the start of the detected identification code is calculated. B is (K-
When changing from (N + 2) to K, (K-B + 1) bits of dummy data are inserted into the digital data string at the start of the identification code and recorded in the data part in the sector. . 5. The optical disc recording apparatus according to claim 1, wherein the data is recorded such that one of the M kinds of identification codes is always present at the head of the data portion in the sector. 6. The optical disk recording method according to claim 2, wherein the recording is performed so that one of the M kinds of identification codes always exists at the head of the data portion in the sector. 7. The optical disc recording apparatus according to claim 1, wherein the N is 32, and the M kinds of identification codes are common to consecutive 24 bits of 32 bits. 8. The optical disc recording method according to claim 2, wherein the N is 32, and the M kinds of identification codes are common to consecutive 24 bits of 32 bits. 9. An optical disc recorded by the optical disc recording apparatus according to claim 1. 10. An optical disc recorded by the optical disc recording method according to claim 2. 11. A unit for reading a digital data string from the optical disk according to claim 9 or 10 in units of sectors in a logical format, and M kinds of N bits from the digital data string existing in the data section in the sector. And a unit for detecting at least one of the identification codes of 1. 12. A digital data string is read from the optical disk according to claim 9 or 10 in units of sectors in a logical format, and M kinds of identification consisting of N bits are identified from the digital data string existing in the data section in the sector. An optical disk reproducing method characterized by detecting at least one of the codes.