KR0145261B1 - Apparatus for recording digital signals - Google Patents

Abstract

In order to easily reproduce very important information at high speed, very important information is composed of fixed-length data and assigned from the head of the block. In order to record a signal to reliably reproduce very important information without increasing the recording rate, a dummy synchronization block is inserted immediately before the data synchronization block containing significant information to define or explain the content of the recorded signal. . In addition, in order to maintain the error correction capability in the normal refresh, the same sync block configuration as in the recorded signal is used for the very important information. In particular, by assigning information to a plurality of sync blocks with respect to very important information, reproduction can be reliably ensured also in the case of trick play.

Description

Digital signal recording device

1 is a block diagram showing a digital signal recording apparatus according to a first embodiment of the present invention;

2 is a block diagram showing a block of the present invention,

3 is a block diagram showing a track of the present invention,

4 is a block diagram showing an audio signal recording area of the present invention;

5 is a block diagram showing a video signal recording area of the present invention;

6 is a block diagram showing a search information recording area of the present invention;

7 is a diagram showing an arrangement of auxiliary data of the present invention;

8 is a block diagram showing a digital signal recording apparatus according to a second embodiment of the present invention;

Fig. 9 is a diagram showing a pattern of tracks formed on magnetic tapes by a digital signal recording apparatus.

* Explanation of symbols for main parts of the drawings

101: video A / D converter 102: video signal processor

103: voice A / D converter 104: voice signal processor

105: auxiliary data generator 106: the first block composer

107: second block composer 108: third block composer

109: fourth block composer 110: dummy data generator

111, 113: switch 112: error correction unit

114: modulator 117,172: selector

170: memory 171: external error correction unit

173: Internal Error Correction Unit

The present invention relates to a digital signal recording apparatus for recording auxiliary data on a recording medium while recording a digital video signal and / or an audio signal. When recording and reproducing the video signal and the audio signal, it is necessary to simultaneously record and reproduce the auxiliary data describing what the signal is apart from the signal itself. For example, the auxiliary data may include information indicating whether the video signal is composed of a 50 Hz system or a 60 Hz system, and information about the number of samples of an audio signal allocated to a block configured in synchronization with the video signal. And information such that once the signal is lost, it becomes impossible to reproduce the entire signal. As a conventional digital signal recording system, a digital audio tape recording system (DAT) for recording only an audio signal is listed. In the DAT, a track formed on magnetic tape is divided into a main area for recording an audio signal and a sub area 1 and a sub area 2 as areas for recording different information, and IBG (gap between blocks), which is a buffer area to be edited, Divided. The auxiliary data is recorded by dividing the main data, which is the block address of the main data block constituting the main area, and the sub-data blocks, which constitute the sub area, into sub IDs of the sub data, which are block addresses.

However, in the above recording method, since the error correction code for the auxiliary data is set only for a smaller capacity than the error correction code for the audio signal, the capacity of the error correction can be ensured only by repetitive recording. . In addition, when recording audio signals and auxiliary data in different areas, necessary auxiliary data may be accidentally lost in the case of editing or the like.

In addition, when recording audio signals, auxiliary data can be allocated at the block address. However, when recording a video signal using the same recording method, since there is a large amount of information to be recorded, the recording rate is repeatedly recorded in the block address. Difficult to make it higher On the other hand, it is not necessary to consider the output of the data during the trick play when recording the audio signal, but the trick play becomes an essential function when recording the audio signal using the same recording method. Particularly important data among auxiliary data for trick-placing should be protected from magnetic tape damage, errors caused by long bursts, or sync block detection errors.

The main object of the present invention is to solve the problem of the conventional digital signal recording method.

That is, an object of the present invention is to provide an apparatus for recording auxiliary data so that auxiliary data recorded at the time of reproduction can be easily protected.

Another object of the present invention is to provide a recording apparatus capable of detecting a sync block in which auxiliary data must be arranged, whether or not normal play or trick play, without increasing the recording rate.

It is still another object of the present invention to provide a digital signal recording apparatus that sufficiently guarantees error correction in normal play.

It is still another object of the present invention to provide a digital signal recording apparatus which cannot avoid the loss of the entire signal even when the sync block with auxiliary data is damaged due to tape damage or long burst during normal play. It is.

According to the first aspect of the present invention, a plurality of sync blocks having a sync pattern, at least one error correcting code composed of a block address, a data symbol, and a parity symbol are continuously arranged. When one or a plurality of block groups are distributed to one track, the reproduction synchronization establishing function is performed by recording the desynchronization block immediately before the synchronization block to which auxiliary data is allocated as recorded data.

The present recording apparatus is configured to give a demerger block for a sync block in which auxiliary data is arranged, thereby ensuring a sync block for arranging auxiliary data between normal play and trick play without increasing the recording rate. To be detected. Therefore, the occurrence of the loss of the entire signal due to the loss of the minor auxiliary data can be avoided, thereby providing a great practical effect.

According to another aspect of the present invention, when recording one or a plurality of block groups by allocating to one track, data for recording auxiliary data is allocated together to one or a plurality of sync blocks belonging to the same block group. By doing so, it is recorded.

According to the present recording apparatus, both the internal parity and the external parity are added to the auxiliary data in the same manner as the video signal and the audio signal, whereby the error detection capability of the normal play is sufficient. Also, for information on any loss that makes it impossible to reproduce the video signal, by recording the information in a plurality of portions of the area, the sync block of any auxiliary data is damaged due to damage or long burst on the recording medium. Even in this case, the loss of the entire signal can be avoided, whereby the practical effect is huge.

Fig. 1 shows a digital video cassette recorder which is a digital data recording apparatus according to the first embodiment of the present invention.

The input analog video signal is converted into a digital video signal by the video A / D converter 101. The digital video signal is supplied to the video signal processor 102 and subjected to filtering, suffling, bit rate reduction encoding, and the like to become video data, which is output to the first block composer 106. The input analog signal is converted into a digital audio signal by the voice A / D converter 103. The digital voice signal is transmitted to the voice signal processor 104, and the voice data is converted into voice data by performing suffling, encoding, or the like, and output to the third block composer 108. The type of the input video signal, the coding scheme, and other information necessary for decoding are supplied from the video signal processor 102 to the auxiliary data generator 105. The sampling frequency, sampling bit width, light and other information of the speech signal are also supplied from the speech signal processor 104 to the auxiliary data generator 105. It also generates recording time, recording date and other information, and generates timecode and others that need to be searched. In addition, the teletext, the program title given by the user, and the like can be supplied to the auxiliary data generator 105 as other information. Information for recovery, information for search, information such as a program title, and other information are configured in the auxiliary data generator 105 with auxiliary data having a fixed length of 5 bytes.

This auxiliary data is output to the second block composer 107, the third block composer 108 and the fourth block composer 109.

In particular, the auxiliary data related to the video signal is output to the second block composer 107, the auxiliary data related to the audio signal is output to the third block composer 108, and the auxiliary data necessary for the search is the fourth block composer 109. ) In the first block composer 106, as shown in Fig. 2 (a), the input video data is composed of a first block of 77 bytes. In the second block composer 107, as shown in FIG. 2 (b), the input auxiliary data relating to the video signal is constituted by the second block of 77 bytes. At this time, the second block composer 107 arranges the auxiliary data by filling from the head of the second block, and records the dummy data in the last two bytes.

In the third block composer 108, the input auxiliary data and the audio data are constituted by a third block of 77 bytes as shown in FIG. At this time, the third block composer 108 puts one auxiliary data at the head of the third block and arranges audio data of a trailing area of 72 bytes. In the fourth block composer 109, one input auxiliary data is composed of a fourth block of 5 bytes as shown in FIG. The dummy data generator 110 generates one byte of dummy data as shown in FIG. 2E and constitutes the fifth block. The first block, the second block, the third block, and the fourth block supply the switch 111. The switch 111 is controlled by the selector 117 and supplies any block to the error control encoder 112. The input block is a coded error correcting code and is supplied to the switch 113.

The first block and the second block are encoded together in the error correcting encoder 112 to generate outer parity, and the outer parity is composed of blocks of 77 bytes, and the blocks of the blocks of the first, second and outer parity are Each is coded in error correction information unit 112 to generate inner parity and adds internal parity to the block. The third block is encoded by the error correcting encoder 112 to generate external parity, the external parity is composed of blocks of 77 bytes, and each of the blocks of the third parity and the external parity is the error correcting code 112. Is encoded in to generate internal parity and adds internal parity to the block. In the switch 113, the fifth block generated in the dummy data generator 110 is supplied. The switch 113 is also controlled by the selector 117, selects an input block according to the selector 117, and outputs it to the modulator 114. In the modulator 114, a block address for detecting a block and a sync pattern are connected before the block, modulated as a sync block, and a modulated signal is output to the recording head 115. FIG. In the recording head 115, the modulation signal is recorded on the magnetic tape 116. Each block is formed on the magnetic tape 116 as shown in FIG.

The track pattern constituted by the recording apparatus of the first embodiment is shown in Fig. 3A.

The gaps 132 and 134 are recorded in the audio signal recording area 131, the video signal recording area 133, and the search information recording area 135. The gaps 132 and 134 are formed so as not to interfere in other areas when rewriting each recording area independently. In the audio signal recording area 131, error correction is performed from the pre-sync block 140, the data sync block 141 composed of the voice data and the auxiliary data, and the data sync block 141, as shown in FIG. The parity sync block 142 and the post sync block 143 composed of the external parity generated by the encoder 112 are sync blocks composed of the fifth block formed in the dummy data generator 110. The data sync block 141 is a sync block composed of a block formed in the third block composer 108. A specific configuration is shown in FIG.

The data arrangement of the video signal recording area 133 is shown in FIG. In the video signal recording area 133, as in the audio signal recording area 131, the head is recorded in the pre-synchronization convex 150, and the post-synchronization block 155 is finally recorded. The auxiliary data and video data are recorded as independent blocks, and the auxiliary data is recorded scattered in two places. Here, the parity sync block 133 is a sync block composed of external parity from the auxiliary sync blocks 151 and 154 and the data sync block 152 by the error correcting encoder 112. The pre-synchronization block 150 and the post-synchronization block 155 are composed of a fifth block formed in the dummy data generator 110. The image sync block 152 consists of a first block formed in the first block composer 106 and the auxiliary sync blocks 151 and 154 consist of a second block formed in the second block composer 107. A specific configuration is shown in FIG.

The data structure of the search information recording area 135 is shown in FIG. The auxiliary shifter block 160 recorded in the search information recording area 135 is composed of blocks formed in the fourth block composer 109. The specific configuration is shown in FIG.

A selector 117 for recording tracks of this configuration controls the switches 111 and 113.

8 shows a second embodiment of the denier data recording apparatus of the present invention.

The fourth block composer 109, the second block composer 107, the third block composer 108, the fourth block composer 109, the switch 111, the error correcting encoder 112, and the selector of the first embodiment. Instead of 117, it is possible to use the memory 170, the external error correcting code 171, the internal error coder 173 and the selector 172.

At this time, the generated audio data, video data, and auxiliary data are stored in the memory 170 according to the address generated by the selector 172. The input data is subjected to error correction encoding by the external error correcting encoder 171, and the external parity is stored in the memory 170. Data stored in the memory 170 is output to the internal error correcting unit 173. Here, the selector 172 can be configured as shown in FIG. 3 except for the memory 170 and the switch 113 such that each block is a block as shown in FIG. .

In the digital data recording apparatus configured as described above, all auxiliary data are allocated sequentially at the beginning of the block or at the beginning of the block. By forming the auxiliary data as fixed length data, the position of the auxiliary data of the block is fixed, and thus the auxiliary data of the block can be easily detected. For example, when using the auxiliary data of variable length, it is necessary to detect the head display every time the length of the auxiliary data is calculated or the specific auxiliary data is detected.

Compared with the above case, the device can reduce the circuit size. In addition, by recording the fixed length, it is possible to prevent the transmission of the error when the error remains even after error correction, thereby making it possible to reliably detect the auxiliary data.

Further, in the digital data recording apparatus configured as described above, the same error correcting code as that in the video data or the audio data can be used for the auxiliary data. By using the same error correcting code, the error correcting ability can be increased and the circuit can be shared, and the circuit size can be reduced, as compared with the case where the error correcting code is performed only by the auxiliary data.

In the video signal recording area 133, the auxiliary signals are interspersed in the two auxiliary synchronization blocks 151 and 154. One auxiliary data is repeatedly recorded on a plurality of tracks, and each position in the tracks is different from each other in adjacent tracks. Then, if one set of auxiliary data is lost due to tape damage in the longitudinal direction or the like, another set of auxiliary data can be obtained. Therefore, the error correction probability of auxiliary data containing important information becomes high, without increasing the redundancy rate. If one auxiliary data is repeatedly recorded on a plurality of tracks and all the data is allocated to the same position in the track, each time an error remains after error correction in the auxiliary synchronization block due to the tape scratches in the vertical direction, The chances of not playing it are quite high. In order to avoid this, when the auxiliary data is allocated to a plurality of locations on one track, the redundancy ratio becomes considerably high.

As shown in FIG. 7, in the video signal recording area 133, after one auxiliary data A is assigned to the auxiliary sync block 151 of the track, it is allocated to the auxiliary sync block 154 of the next track. do. Similarly, after the auxiliary data B is allocated to the auxiliary sync block 154 of the track, it is allocated to the auxiliary sync block 151 of the next track. By recording in this manner, when an uncorrectable error occurs in the longitudinal direction of the magnetic tape, the auxiliary data can be reliably reproduced without increasing the redundancy ratio. In the audio signal recording area 131, after the data synchronization block located at the head of the area is used for the auxiliary data (C) and (D) of the track, the data synchronization block located at the end of the area is used as the auxiliary data (C), Used for (D). Therefore, when an uncorrectable error occurs in the longitudinal direction of the magnetic tape, the auxiliary data can be reliably reproduced without increasing the redundancy rate.

In this embodiment, the sync block composed of the first block, the second block, the third block, and the external parity is arranged as shown in Figs. 4, 5, and 6, but this configuration is arbitrary, Even if it is comprised differently in a present Example, the same effect is acquired.

The error correcting code and the parity structure used in the present invention are just examples, and the same effect can be obtained by using the error correcting code or using three or more generation codes.

The auxiliary data is information of Table 1, but it is not necessary to record or record the information of Table 1 in accordance with digital data for recording other information. In addition, auxiliary data of a specific area may be recorded in another area.

Here, the auxiliary data on the other hand is 5 bytes in length, but as long as the length of the auxiliary data is fixed, the effects of the present invention can be obtained even when the lengths are different. Instead of being composed of 77-byte blocks of video data and 72-byte blocks of audio data, the effects of the present invention can also be obtained for other values. The number of sync blocks in each area is one example, and the same effect can be obtained for other values.

As for the sync pattern, the bit pattern and size may be arbitrary as long as each sync block can be recognized. For the block address, the addressing scheme may also be arbitrary as long as each sync block can be identified.

The length of the pre-sync block and the post-sync block composed of dummy data may be arbitrary.

The bit pattern of the dummy data may be arbitrary, and the fixed bit pattern or the information can be recorded.

When playing the track configured as described above, in the case of the normal play, since the internal parity and the external parity are added, the error correction capability for the auxiliary data is sufficient, and the loss of the entire signal due to the loss of the auxiliary data can be avoided. .

The configuration of the embodiment is only one example, and since the configuration of the audio signal recording area, the video signal recording area and the search information recording area can be arbitrary, it may be changed as necessary and the signal may not always be recorded.

Instead of dividing the auxiliary data into two, the sub data may be divided into arbitrary coefficients. The information whose loss makes the reproduction of the video signal impossible is doubled, but may be allocated more than three times. A large number of other auxiliary data may also be allocated. In addition, for a large number of allocation data, when the external parity is added, it is arranged so as to form elements of different codewords, so that error correction capability can also be reinforced in normal play.

Claims (7)

A digital signal recording apparatus for recording main data and associated auxiliary data on a recording medium, comprising: first encoding means for encoding a first input digital signal to obtain first main data, and a second input digital signal for encoding a second input digital signal. Second encoding means for obtaining main data, first auxiliary data of fixed data length having information relating to the first main data, second auxiliary data of fixed data length having information relating to the second main data, and Auxiliary data generating means for generating third auxiliary data having a fixed data length having different information, first block constituting means for constructing the first main data into a first block at a first predetermined data length, and the first block. Second block constituting means for constituting a second block by sequentially arranging a first predetermined number of one auxiliary data; and one second auxiliary data and the second main data as second predetermined data. Third block constituting means for sequentially arranging the third block by length, fourth block constituting means for constituting each of the third auxiliary data having a fixed data length as a fourth block, and dummy data generation for generating dummy data. Means and the first, second, third and fourth blocks together with the dummy data as a recording block, so that at least one dummy data, at least one second block and at least one A first recording block composed of the first block, a second recording block composed of at least one dummy data and at least one third block arranged sequentially, and a third recording block composed of at least one fourth block; And block arrangement means for forming the first, second, and third recording blocks in a predetermined order, and at least one of the first, second, and third recording blocks. Recordable And a recording means for recording the output of said block arrangement means by modulation in the form of a plurality of tracks on a recording medium so as to be recorded in a plurality of tracks having a space between each adjacent two blocks of the lock. Signal recorder. The method of claim 1, wherein the block arranging means sequentially arranges another first recording block by sequentially arranging at least one second block, at least one first block and at least one second block in this order. Digital signal recording device characterized in that 7. The apparatus of claim 6, wherein at least one second block disposed in front of the at least one first block in the first recording block and at least one disposed behind the at least one first block in the other first recording block. Create the first recording block and the other first recording block such that the second block has at least one same auxiliary data, and the recording means converts the first recording block and the other first recording block into the recording medium. A digital signal recording apparatus, characterized in that each recording in two adjacent special racks. The digital signal recording apparatus according to claim 1, wherein the first input digital signal is a digital video signal. 5. The digital signal recording apparatus according to claim 4, wherein the second input digital signal is a digital audio signal. 2. The apparatus of claim 1, wherein the block arranging means includes error correcting and encoding means for performing error correcting encoding, wherein at least one dummy data, at least one second block, and at least one first are arranged sequentially. The first recording block comprising at least one block and at least one parity block generated by error correcting and encoding the at least one second block and the at least one first block, at least one dummy data, and at least one first And a second recording block comprising three blocks and at least one parity block obtained by error correcting and encoding the at least one third block. 2. The block arranging means according to claim 1, wherein the block arranging means is the jth one of the plurality of third blocks in another second recording block, and the second auxiliary data is the ith one of the plurality of third blocks in the second recording block. The second recording block and the other second recording block each having a plurality of the third blocks are formed so as to be the same auxiliary data as the auxiliary data of (ij); And recording the second recording block and the other second recording block into two tracks, respectively.