JPH09219065A - Data recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify position information for designating the position of packet recorded on a recording medium when data of packet unit being length inputted into a data recorder are recorded on the recording medium. SOLUTION: In this recorder, data of two packets do not coexist in one block of the track of the recording medium by converting data of the packet unit being the length of N bytes inputted by a block converter 111 into block units prescribed length of L pieces and M bytes and recording the data of block units obtained by the lock converter 111 on the recording medium by a recording circuit 101.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data recording device for recording digital data on a recording medium.

[0002]

2. Description of the Related Art Recently, as the performance of computer equipment has improved, the amount of data to be handled has increased, and with the increase in the amount of data, it has been required to increase the capacity of recording media. In order to meet such requirements, commercialization or development of an apparatus having a large-capacity recording medium is in progress. Currently available data recording devices include, for example, hard disk devices and CDs.
-Using a disk medium such as a ROM device, 8m
Some tape media such as m tape and DAT (Digital Audio Tape) are used. Further, the capacity of these data recording devices has been further increased by the technological development of recording media. The data of the computer used in these data recording devices are handled in file units, and each file is composed of packets of a fixed length as one information unit.

In a conventional data recording device using a tape as a recording medium, computer data is recorded on the tape in block units. Each recorded block has data in which the input packet unit data is divided into fixed bytes, synchronous data, ID data, error correction code (ECC), and the like. FIG. 6 is a block diagram of one block 3 recorded on a recording medium by a conventional data recording device. The block-unit data thus configured is modulated and sequentially recorded in the data recording area on the track of the tape which is the recording medium. FIG. 7 shows an arrangement of a plurality of blocks 3 recorded on the track 2 of the tape 1. The predetermined number of tracks 2 recorded in this way is set as one editing unit (frame), and if necessary, an error correction code is further added to make one frame.

As described above, when the conventional data recording apparatus records the input data formed in packet units on the tape, the data in packet units is sequentially stored in a plurality of blocks. Therefore, when specifying a specific packet, it is necessary to specify the track number, block number, and byte number, which are information (position information) regarding the position where the packet is recorded. For example, a tape capable of recording a current television signal for 4 hours and 30 minutes (Specifications by the HD-VCR Council)
f Consumer-Use Digital VCRs) about 500
Since it is possible to record tens of thousands of tracks, if the track number is 23 bits and the number of blocks of data that can be recorded on one track is 135, the block number is 8 bits and the number of bytes of data in one block is 77 bytes , 7 bits are required for each byte number. For this reason, as the amount of data for position information, these 3
A total of 38 bits is required. As described above, in the conventional data recording device, when a specific packet is designated during track reproduction, the position of the packet designated based on the position information (track number, block number, byte number) represented by 38 bits. Is detected.

[0005]

As described above, in the conventional data recording apparatus, the data transmitted from the outside of the apparatus in packet units are recorded in blocks. For example, if the length of one packet is N bytes and the length of one block is M bytes (N> M), then the packet length N bytes is the block length M.
If it is an integral multiple of bytes, the data of one packet is stored in at least G (G = N / M) blocks. However, if the packet length N bytes is not an integral multiple of the block length M bytes, at least L (L
= (Int (N / M) +1)). Int (N / M) in the above equation is N
Is the integer part of the value divided by M, where int is the mathematical term (in
Abbreviation for teger) is an abbreviation that indicates the integer part. As a result,
In the Lth block, T bytes (T = N−M ×
The data of the next packet is recorded after the Lth eye.

FIG. 8 shows a state in which input data 4 in packet units is converted into recording data 5 in block units. FIG.
As shown in, the data of two packets are mixed in the L-th block L recorded by the conventional data recording device. That is, the head data of the next packet is recorded from the middle of the Lth block L. Similarly, with respect to data of packets subsequent to that packet, data of two packets may be mixed and recorded in one block. In order to specify a specific packet in the data recorded in such a mixed format, it is necessary to specify the data of all the track numbers, block numbers, and byte numbers.
For this reason, in the conventional data recording device, there are many things about the structure of the file allocation table (FAT) and, when accessing a specified packet, which track, which block, which byte are accessed. However, there is a problem in that the circuit configuration for performing arithmetic processing becomes complicated because the position information of is required.

The present invention has been made to solve the above problems, and simplifies the positional relationship between input packet-unit data and recorded block-unit data, and performs arithmetic operations for position information. The purpose is to simplify the process.

[0008]

According to the data recording apparatus of the present invention, the data of one packet having the length N input by the block converting means is transferred to L number of blocks, each block having a length M shorter than the N. It is configured such that the data is converted into blocks, the recording means performs predetermined signal processing on the data in block units obtained by the block conversion means, and records the signal on the recording medium. Since the data recording device of the present invention is configured as described above, the data of one packet is always converted into a fixed number of blocks and recorded, and the position information for designating the packet recorded on the recording medium is significantly increased. It is possible to reduce the number, and it is possible to simplify the positional relationship between the input packet unit data and the recorded block unit data.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The data recording device of the present invention is a block conversion means for converting input data of one packet having a length N into L blocks, each block having a length M shorter than N. And recording means for performing a predetermined signal processing on the data in block units obtained by the block conversion means and recording the signal-processed signal on a recording medium. Therefore, the data recording apparatus of the present invention can specify the position of the data in packet units recorded on the recording medium based on the position information having a small data amount.

Further, in the data recording apparatus of the present invention, the block conversion means adds auxiliary data to each final block storing each packet. Therefore, the empty data in the block can be effectively used.

Also, in the data recording apparatus of the present invention, in the block conversion means, the length of one packet is N,
When the length of one block is M, which is shorter than N, the number L of blocks for converting one packet is set to the value of the integer part of the value obtained by dividing the value of N by M and rounding up to the nearest whole number. There is. Therefore, it is possible to simplify the positional relationship between the input packet unit data and the recorded block unit data.

Further, in the data recording apparatus of the present invention, when the recording means can arrange K blocks in one track, the number of packets stored in one track is converted into one packet. It is set to the number of integer parts of the value obtained by dividing K by the number L of blocks. Therefore, it is possible to simplify the positional relationship between the input data in packet units and the recorded data in block units.

Further, in the data recording apparatus of the present invention, when the recording means can arrange K ₂ blocks in H tracks constituting one frame, the number of packets to be stored in the H tracks can be set. The number of integral parts of the value obtained by dividing K ₂ by the number L of blocks converted from one packet is set. Therefore, it is possible to indicate the position information regarding the input data in packet units with a small amount of data.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, preferred embodiments of the data recording apparatus of the present invention will be described with reference to the drawings. << Embodiment 1 >> A first embodiment of the data recording apparatus of the present invention will be described below with reference to FIGS. Figure 1
FIG. 3 is a block diagram showing a configuration of a data recording device of the embodiment. FIG. 2 is an explanatory diagram showing a conversion state from input data in units of packets to recording data in units of blocks in the data recording apparatus of the first embodiment. FIG. 3 is an arrangement view of data in units of packets on a track recorded by the data recording apparatus of the first embodiment. In the first embodiment, a data recording device in which input packet-unit data is recorded on a tape which is a recording medium will be described as an example of the present invention.

As shown in FIG. 1, the data recording apparatus of the first embodiment comprises a block converter 111, a recording circuit 101, a head 102, and a tape 103 which is a recording medium. The packet-unit data input to the data recording device of the first embodiment is input to the block converter 111. The input data is converted by the block converter 111 into a plurality of blocks having a fixed length. At this time, assuming that the length of one packet is N bytes and the length of one block is M bytes (N> M), L (L> N / M) blocks are allocated to one packet. . In this embodiment, N is not an integral multiple of M, and L is an integer. As shown in FIG.
The input data 104 in packet units is the block converter 11
1 is converted into block-unit recording data 105,
The first packet 1 of the input data 104 is sequentially stored from the first block 1 to the Lth block L.
In this way, when the final data of the packet is stored in the L-th block L, the remaining T bytes (T = N- (M ×
L)) is added with dummy data 106. In the same manner, the input data and the dummy data 106 for each packet are stored using the L blocks for the subsequent packets.

The print data 105 converted into blocks in the block converter 111 is output to the print circuit 101. In the recording circuit 101, synchronization data, ID data, error correction code, etc. are added to each block. Then, these data are modulated in the recording circuit 101 into recording signals suitable for recording on the tape 103. The recording signal output from the recording circuit 101 is recorded by the head 102 in the data recording area on the track of the tape 103. Therefore, as the position information, the position of a specific packet can be specified by only two kinds of data, that is, the track number and the block number, and the byte number that was necessary in the conventional device is unnecessary. Therefore, according to the data recording apparatus of the first embodiment, it is possible to simplify the relationship between the input data in packet units and the data in block units corresponding to the packet.

In the block converter 111 described above, L
When one packet of data is stored in this block, T bytes (T = N-
Although dummy data was recorded in the area of (M × L)),
A case where auxiliary data is recorded instead of the dummy data will be described below. The auxiliary data recorded in the L-th block L is management data relating to a packet, for example, a number indicating the order of input data, a number indicating the order of packets in the input data, and a number indicating the order of packets from the beginning of the tape. Etc. By recording the management data in the block in this way, it becomes possible to know the information regarding the packet, for example, the number of the packet in the input data. Alternatively, T bytes that are not necessary for recording the input data are divided into L pieces and distributed to each block, and the allocated area indicates which block of the packet corresponds to this packet. It is also possible to add a number.

The block converter 11 of the first embodiment described above.
If the minimum number of blocks is to be assigned to one packet in No. 1, the number of blocks L is L = in
t (N / M) +1. That is, the number of blocks L is a value obtained by adding 1 to the integer part of the value obtained by dividing N by M. As a result, the input data can be efficiently recorded on the track of the tape, and as a result, the amount of data that can be recorded on the tape is increased. In the above-mentioned recording circuit 101, when K blocks are arranged to be recorded on one track, J (J = int (K / L)) packets are recorded on one track. Will be placed. Therefore, the position of the packet on the tape, which is the recording medium, can be specified only by two types of data, the track number and the packet number indicating the position of the packet recorded in the track. Since the position of the packet can be specified only by the track number and the packet number in this way, the amount of data for the position information is reduced, and the circuit configuration for arithmetic processing can be simplified.

FIG. 3 is a diagram showing the arrangement of data in units of packets stored in the data recording area of the track 107. The number of blocks K (K = J × L) on one track is one packet. A case where the number of blocks is an integral multiple of L is shown. When the length N of one packet in the input data 104 in packet units is 2064 bytes and the length M of one block is 77 bytes, the data of each packet is 27.
(27 = int (2064/77) +1) blocks. If the number K of blocks arranged on one track is 135, 5 packets (5 = int (135/27)) are always arranged on one track. Therefore, the packet number can be indicated by 3 bits, and the amount of data for the position information is further reduced.

As described above, according to the configuration of the first embodiment, the amount of data for the position information for designating a specific packet is reduced, and the packet designated at the time of reproduction is accessed. Since it is possible to simplify the arithmetic processing for determining the corresponding packet, it is possible to reduce the circuit scale for the arithmetic processing. In the first embodiment, the length N of one packet is 1
Although the case where the length N of one block is not an integral multiple of the length M of the block has been described, if the length N of the packet is an integral multiple of the length M of the block, the data of one packet is G (G =
N / M; G is an integer) block and is stored in the first
The positional relationship between the input data in units of packets and the recording data in units of blocks is simplified as in the above embodiment. In the block converter, the data recording device of the present invention is such that, when one packet has a length of N and one block has a length of M, the number of blocks L for converting one packet is L, and N is the M. The case where N is an integer multiple of M is set by setting it to the value of the integer part of the value obtained by rounding up the fractional part of the value divided by.

<< Second Embodiment >> Next, a second embodiment of the data recording apparatus of the present invention will be described with reference to FIGS. FIG. 4 is a layout diagram of packets on a track by the data recording apparatus of the second embodiment of the present invention, and FIG. 5 shows that one frame is composed of three tracks in the data recording apparatus of the second embodiment. It is a layout diagram of the packet on the track when there is. The track shown in FIG. 5 is a general track showing two recording areas, a video signal recording area and an audio signal recording area.

The data recording apparatus of the second embodiment has the same structure as that shown in FIG. 1 in the first embodiment. The method of allocating the input data in units of packets to the recording data in units of blocks by the data recording apparatus of the second embodiment is the same as the allocation method shown in FIG. 2 in the first embodiment. Further, in the first embodiment, the auxiliary data may be stored in the L-th block as in the first embodiment. In the second embodiment, X blocks are recorded on one track, and one frame is composed of H tracks. According to the data recording apparatus of the second embodiment, K ₂ (K ₂ = H × X) blocks can be recorded in one frame, and packets converted into L blocks can be recorded in J frames. ₂ (J ₂ = int (K ₂ / L)) pieces can be arranged.

For example, the number of blocks per track is 9 in addition to the 135 blocks in the first embodiment.
If you add 144 to add 9 per track
Since 27 blocks are added, 27 blocks are added in 3 tracks. Therefore, the number of blocks L (27) into which one packet is converted is added. Therefore, assuming that the number of tracks H in one frame is 3, the number of packets J ₂ per frame is just 16 (16 = (144 × 3)
/ 27). FIG. 5 shows the arrangement of packets on the three tracks at this time. As described above, since one frame is composed of three tracks, the frame number can be used instead of the track number as the position information for identifying the packet. Since the number of frames per tape is 1/3 of the number of tracks, for example, in the case of a tape capable of recording about 5 million tracks, the number of frames is about 1.7 million frames. The frame number for specifying the frame can be indicated by 21 bits.

The number J of packets per frame
_{Since 2} is 16 (00 to 15), the data amount required for the packet number is 4 bits. This number of 16 is a power of 2 and can allocate all the data amount of 4 bits, eliminating redundant use. Therefore, in the data recording apparatus of the second embodiment, a specific packet can be designated only by the frame number and the packet number, so that the amount of data for position information is greatly reduced as compared with the conventional apparatus. be able to. Further, in the data recording apparatus of the second embodiment, it is possible to suppress the occurrence of errors caused by dropout or the like by performing error correction processing and interleave processing within a frame.

In the data recording apparatus of the second embodiment described above, the case where the number H of tracks per frame is 3 has been described. However, the number H of tracks per frame is doubled to 6 In this case, for example, assuming that the length N of one packet is 2064 bytes and the length M of one block is 77 bytes, the number J ₃ of packets per frame is 32 (int 144 × 77 × 6/206).
4) In this case, the number of frames per tape is half of that in the above-described second embodiment (the number of tracks per frame H = 3), and thus the frame number for indicating the frame in this case. Is represented by a data amount of 20 bits. Further, in this case, the number J ₃ of packets per frame is 32 (00 to 31), so that the amount of data required to represent the packet number is 5 bits. Since the number 32 is a power of 2, all the data amount of 5 bits can be allocated, and redundant use can be eliminated.

Further, when the number of tracks H per frame is further doubled to 12, if the length N of one packet is 2064 bytes and the length M of one block is 77 bytes, 1 The number of packets J ₄ per frame is 64. In this case, the number of frames per tape is half that in the case where the number of tracks H per frame is 6, and the number of bits of the frame number for indicating the frame in this case is 19 bits. . Further, in this case, the number of packets J ₄ per frame is 64, so that the amount of data required to represent the packet number is 6 bits. This number of 64 is also a power of 2, and it is possible to allocate all the data amount of 6 bits, so that redundant use can be eliminated.

With the above configuration, when the input data in packet units is recorded on the recording medium, the data amount of the position information for designating the position where the data of the specific packet is recorded can be reduced and reproduced. It is possible to simplify the arithmetic processing for accessing the designated packet at time. Note that the data recording apparatus in each of the above-described embodiments of the present invention has been described by taking the tape as an example of the recording medium, but the technique of the present invention can be applied to other recording media such as a disc, and a recording block The arrangement is also not limited to the arrangement of the above-mentioned embodiment.
If there are a plurality of packet lengths in the input data, the block converter detects the packet length N, and based on the detected length N, determines the number of blocks L of the packet. Even if configured to ask
It is possible to obtain the same effects as those of the above-described embodiments. Further, in the above-mentioned second embodiment, the case where the number H of tracks per frame is 3, 6, and 12 has been described, but the data recording apparatus of the present invention is limited to these numbers. Instead, the same effect can be obtained by setting an arbitrary number.

[0028]

In the data recording apparatus of the present invention, the input data of one packet having the length N is converted into the recording data of the L blocks having the length M, and the data of the two packets becomes 1. It was recorded so that it would not be mixed in one block. This makes it possible to reduce the amount of data for position information that specifies the position of a packet recorded on the recording medium, and at the same time, input data in packet units input and recorded data in block units recorded. The positional relationship of can be simplified.

According to the data recording device of the present invention,
When accessing a specific packet during reproduction, it is possible to simplify the arithmetic processing for determining the corresponding packet, and therefore it is possible to reduce the circuit scale for performing the arithmetic processing.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a data recording device according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram of conversion of input data in units of packets into recording data in units of blocks in the data recording apparatus according to the first embodiment of the present invention.

FIG. 3 is a layout diagram of data in units of packets on a track by the data recording device of the first embodiment of the present invention.

FIG. 4 is an arrangement view of data in units of packets on a track by the data recording device of the second embodiment of the present invention.

FIG. 5 is an arrangement view of data in units of packets on a track by the data recording apparatus of the second embodiment of the present invention.

FIG. 6 is a layout diagram of data in block units recorded on a recording medium by a conventional data recording device.

FIG. 7 is a layout diagram of tracks on a tape and block-based data layout on a track by a conventional data recording device.

FIG. 8 is an explanatory diagram of a method of converting input data in units of packets into recording data in units of blocks by a conventional data recording device.

[Explanation of symbols]

 101 recording circuit 102 head 103 tape 111 block converter

Claims (5)

[Claims] 1. Input data of one packet having a length N, L in which each block has a length M shorter than said N.
Block conversion means for converting into individual blocks, and recording means for performing predetermined signal processing on the data in block units obtained by the block conversion means and recording the signal-processed signal on a recording medium. A data recording device characterized in that 2. The data recording apparatus according to claim 1, wherein the block conversion means adds auxiliary data to each final block storing each packet. 3. In the block conversion means, when the length of one packet is N and the length of one block is M shorter than N, the number L of blocks for converting one packet is set to N. 3. The data recording apparatus according to claim 1, wherein the value divided by the M is set to the value of the integer part of the value rounded up after the decimal point. 4. In the recording means, when K blocks can be arranged on one track, the number of packets to be stored on one track is determined by the number L of blocks converted from one packet. 4. The data recording device according to claim 1, wherein the number is the integer part of the divided value. 5. When, in the recording means, K ₂ blocks can be arranged in H tracks constituting one frame, the number of packets to be stored in the H tracks is calculated by converting one packet into a block. 5. The data recording device according to claim 1, wherein the number of integers of the value obtained by dividing K ₂ by the number L of the data recording units is set.