JPH08147900A - Digital signal recording device and reproducing device - Google Patents

Abstract

PURPOSE: To improve the error correcting ability of an error correction inspecting code by recording a signal used for a high speed reproduction in the prescribed area on a track and providing an area in which the error correction inspecting code is recorded in an area adjacent to the above prescribed area. CONSTITUTION: In this device, for the sake of making use of a limited data area, an area in which an error correcting code is added is arranged on the locus on which rotary heads 189a and 189b scan at the time of a special reproduction and also data are generated so as to add the error correcting code to data for a normal reproduction in the case a user attaches importance to the picture quality at the time of the normal reproduction and data are generated so as to add the error correction code to data for the special reproduction in the case where the user attaches importance to the reproduced picture quality at the time of the special reproduction. Thus, the error correcting ability at the time of decoding the error correction at the time of the normal reproduction is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital video tape recorder having a track format for recording a digital video signal and a digital audio signal in predetermined areas of diagonal tracks (hereinafter
It is referred to as a digital VTR. ), A digital video signal and a digital audio signal are input as a bit stream, and the present invention relates to a digital signal recording device and a reproducing device for recording the bit stream.

[0002]

21 is a track pattern diagram of a conventional general home-use digital VTR. In the figure, a diagonal track is formed on the magnetic tape, and one track is a video area for recording a digital video signal,
It is divided into two areas, an audio area for recording digital audio signals.

There are two methods for recording video and audio signals on such a home digital VTR. One is a so-called baseband recording method in which an analog video signal and an audio signal are input and a data rate is reduced and recorded by using a high-efficiency encoder for video and audio. The other is a so-called transparent recording system for recording a digitally transmitted bit stream.

ATV being discussed in the United States
The latter transparent recording method is suitable for recording the (Advanced Television) signal. The reason is that the ATV signal is already a digitally compressed signal and a high-efficiency encoder or decoder is not necessary, and since it is recorded as it is, there is no deterioration in image quality. On the other hand, the disadvantage is the image quality during high-speed reproduction, special reproduction such as still and slow reproduction. Particularly, if the bit stream is recorded on the diagonal track as it is, almost no image can be reproduced at the time of high speed reproduction.

As a method of the digital VTR for recording the above-mentioned ATV signal, "Intern" held in Ottawa, Canada from October 26 to 28, 1993.
national Workshop on HDTV '
"A Recording" in the technical announcement in "93"
Method of ATV data on aC
There is an "Digital Summarization VCR". Hereinafter, this content will be described as a conventional example.

As a basic specification of a home digital VTR prototype, SD (Standard Define) is used.
mode), the recording rate of the digital video signal is 25 Mbps, and the field frequency is 60 Hz.
In some cases, one frame of video is recorded in a video area of 10 tracks. Here, if the data rate of the ATV signal is set to 17 to 18 Mbps, transparent recording of the ATV signal becomes possible in this SD mode.

FIG. 22 is a diagram showing the head scanning loci of the rotary head during normal reproduction and high-speed reproduction of the digital VTR. In the figure, adjacent tracks are alternately recorded obliquely by heads having different azimuth angles. During normal reproduction, the tape feed speed is the same as during recording, so the head moves along the recording track as shown in FIG.
Can be traced like. However, during high speed reproduction, the tape speeds are different, so that it is possible to trace across several tracks and reproduce only the fragments of each same azimuth track. FIG. 22B shows a case of fast-forwarding at 5 times speed.

In the MPEG2 bit stream (ATV
The bit stream of the signal substantially conforms to the MPEG2 bit stream. ), Only intra-coded blocks can be independently decoded without reference to other frames. If the MPEG2 bit stream is recorded on each track in sequence, the reproduction data at the time of high-speed reproduction is the intra-coded data separated from the reproduction signal reproduced intermittently. The image will be reconstructed using only the data. At this time, the area to be played is not continuous on the screen, and
Pieces of blocks will spread across the screen. Furthermore, since the bitstream is variable length coded,
There is no guarantee that all of the screens will be updated periodically,
Some parts may not be updated for a long time. As a result, the image quality at the time of high speed reproduction cannot be said to be sufficient, and it cannot be accepted in a home digital VTR.

FIG. 23 is a block diagram of a conventional digital VTR capable of high speed reproduction. Here, the video area of each track includes a main area for recording bit streams of all ATV signals, and an important part (HP) of a bit stream used when an image is constructed during high-speed reproduction.
(Data) is divided into a copy area for recording. During high-speed playback, only the intra-coded block is effective, so this is recorded in the copy area. However, in order to further reduce the data, the low-frequency components are extracted from all intra-coded blocks and the HP data To record as. Figure 2
3, 1001 is an input terminal of the bit stream,
2 is a bit stream output terminal, 1003 is an HP data output terminal, 1004 is a variable length decoder, 1005 is a counter, 1006 is a data sampling circuit, and 1007 is E.
This is an OB (End of Block) addition circuit.

An MPEG2 bit stream is input from an input terminal 1001, directly output from an output terminal 1002, and sequentially recorded in a main area. On the other hand, the bit stream from the input terminal 1001 is also input to the variable length decoder 1004, the syntax of the MPEG2 bit stream is analyzed, an intra image is detected,
A counter 1005 generates timing, a data extracting circuit 1006 extracts low frequency components of all blocks of an intra image, and further, an EOB adding circuit 1
In 007, EOB is added to form HP data, which is recorded in the copy area.

FIG. 24 is a diagram showing an outline of a conventional digital VTR during normal reproduction and high-speed reproduction. During normal playback, all bitstreams recorded in the main area are played back, and MPEG2 outside the digital VTR is played.
Sent to the decoder. HP data is discarded. On the other hand, during high speed reproduction, only HP data in the copy area is collected and sent to the decoder, and the bit stream in the main area is discarded.

Next, the arrangement of the main area and the copy area on one track will be described. FIG. 25 is a head scanning locus diagram during general high-speed reproduction. If the tape speed is an integral multiple speed and phase lock control is performed, head scanning is synchronized with the same azimuth track. Therefore, the position of the reproduced data is fixed. In FIG. 25, if it is assumed that the part where the output level of the reproduction signal is higher than -6 dB is reproduced, the shaded area is reproduced by one head. FIG. 25 shows an example of 9x speed, and at 9x speed, signal reading of this shaded area is guaranteed. Therefore, HP data may be recorded in this area. However, at other speeds, signal reading is not guaranteed and this area must be chosen for reading at some tape speeds.

FIG. 26 is a diagram for explaining an overlap area at a plurality of conventional high-speed reproduction speeds, showing an example of three tape speed scan areas in which the heads are synchronized with the same azimuth track. The area scanned at each tape speed has some overlapping areas. A copy area is selected from these areas to ensure the reading of HP data at different tape speeds. Although FIG. 26 shows the cases of fast-forwarding at 4 times, 9 times, and 17 times, these scan areas are the same as those at the time of fast-forwarding at −2 times, −7 times, and −15 times.

At some tape speeds it is not possible for the head to trace the exact same area. This is because the number of tracks traversed by the head differs depending on the tape speed. In addition, it should be possible to trace from any one of the same azimuth tracks. FIG. 27 shows examples of head scanning loci at different tape speeds. In FIG. 27, areas 1, 2, and 3 are selected from the overlapping area of 5 × speed and 9 × speed. By repeatedly recording the same HP data on 9 tracks, the HP data can be read at either 5 × speed or 9 × speed.

FIG. 28 is a diagram showing two head scanning loci at the time of 5 × speed reproduction in the conventional digital VTR. As you can see, the same HP for the same number of tracks as the tape speed
By repeatedly recording data, HP data is
Reading can be performed by the head synchronized with the same azimuth track. Therefore, by duplicating the HP data for the same number of tracks as the maximum tape speed for high-speed reproduction, the duplicate HP data can be guaranteed to be read at both the forward and backward directions at some tape speeds. You can

FIG. 29 is a track layout diagram in a conventional digital VTR, showing an example of a main area and a copy area. In the home digital VTR, the video area of each track is composed of 135 sync blocks, the main area is 97 sync blocks, and the copy area is 32 sync blocks. This copy area is shown in FIG.
The overlapping area corresponding to 4, 7, and 17 times speed shown by is selected. In this case, the main area data rate is about 1
Since the same data is recorded in the copy area 17 times at 7.46 Mbps, it becomes about 338.8 kbps.

[0017]

Since the conventional home-use digital VTR is constructed as described above, special reproduction data is recorded in the copy area many times, which results in special reproduction. The recording rate of the data for use is extremely low, and there is a problem in that a reproduced image quality cannot be sufficiently obtained particularly in slow reproduction or high speed reproduction. For example, if the intra-frame is 2 frames / second, ATV
The data amount of only intra-coding of the signal is predicted to be about 3 Mbps, but in the conventional example, only about 340 Kbps can be recorded, and the reproduced image quality is extremely deteriorated.

FIG. 30 shows the structure of the error correction code in the video signal area and audio signal area in one track of the digital VTR defined in the SD mode (hereinafter referred to as SD standard). In the SD standard, the error correction code of the video signal area is recorded in the recording direction (85, 7
7, 9) Reed-Solomon code (hereinafter, referred to as C1 check code) is used in the vertical direction (149, 138, 12) Reed-Solomon code (hereinafter, referred to as C2 check code). Also, as an error correction code in the audio signal area, the same as the video signal in the recording direction (85, 77, 9)
Reed-Solomon code (C1 check code) is used in the vertical direction (14, 9, 6) Reed-Solomon code (hereinafter referred to as C3 check code). Further, one sync block is shown in FIG. As shown in FIG. 31, it is composed of 90 bytes, of which the sync pattern and the ID signal are recorded in the first 5 bytes, and the error correction code (C1 detection code) is recorded in the rear 8 bytes. It

As described above, the ATV signal is data-compressed using the compression method based on motion compensation prediction. The compressed data is the intra data (field, field, which can restore the image using only the reproduced data).
Or intra-frame coding) and inter-data (field or inter-frame coding) for restoring an image using reference field (or frame) data and reproduction data. Therefore, if an error occurs in the reproduced data, the error propagates to a plurality of fields or frames in the ATV signal, which is visually unsightly. Further, when the SD standard digital VTR is used as a storage medium for storing data such as a computer or a program, it may be a dropout caused by scratches on the tape or dust adhering to the magnetic tape. It is desired to add a stronger error correction code to the data that has not been reproduced so as to restore it (error correction).

Further, during special reproduction (high-speed reproduction, slow reproduction, still reproduction, etc.), since the rotary head crosses the recording track diagonally, the reproduction signal is intermittently reproduced from each track. Therefore, an error correction block (video data) as shown in FIG. 30A cannot be constructed during special reproduction. Therefore, during special reproduction, only the error correction by the C1 check code is applied to the reproduced data.

When only the error correction by the C1 check code is applied and the symbol error rate is 0.01, the error detection probability is 1.56 × 10 ⁻³ , and one error is detected in about 8 sync blocks. Will be Especially during special reproduction, the reproduction output is not stable, so that the symbol error rate often becomes 0.01 or more. Since the recorded data is variable-length coded, if an error occurs, the reproduced data cannot be used thereafter, which causes deterioration of the reproduced image quality. Further, residual error is also very occurrence frequency as high as 7.00 × 10 ^{over 8.}

The present invention has been made in order to solve the above-mentioned problems, and it is an error correction for correcting an error occurring particularly during normal reproduction or during special reproduction such as slow reproduction, still reproduction, high-speed reproduction and the like. An object of the present invention is to obtain a digital signal recording device and a reproducing device which have improved capability and improved reproduced image quality.

[0023]

According to a first aspect of the present invention, there is provided a digital signal recording apparatus for recording a normal recording signal on an inclined track formed on a surface of a magnetic tape by a rotary drum on which two types of azimuth heads are mounted. A signal used for high-speed reproduction is taken out and the signal used for high-speed reproduction is recorded in a predetermined area on the track. Further, an error correction check code area for recording an error correction check code is provided in an area adjacent to the predetermined area on the track for recording a signal used for the high speed playback, and at least high speed playback is provided in the error correction check code area. Error-correction check code / normal-reproduction error-correction check-code, one of the two kinds of signals is generated and recorded, and the signal recorded in the error-correction-check code area is the two kinds of signals. A signal for identifying one of them is generated and recorded on the track.

According to a second aspect of the present invention, the digital signal recording apparatus adds a signal for identifying one of the two types of signals to the ID signal or the subcode area in the recording signal and records the signal. It is configured to do.

Further, in the digital signal recording apparatus according to the third aspect of the present invention, when the signal recorded in the error correction check code area is the error correction check code for high speed reproduction, it is recorded in the error correction check code area. A signal is the error correction check code for high-speed reproduction and the fixed data determined in advance. When the error correction check code for normal reproduction is used, the signal recorded in the error correction check code area is used for error correction for normal reproduction. The check code is configured.

Further, in the digital signal recording apparatus according to the fourth aspect of the present invention, when a position where the error correction check code area is provided has a predetermined area on the track for recording the data used for the high speed reproduction, If a predetermined area for recording the data used for the high-speed reproduction does not exist on the track adjacent to the area for recording the data used for the high-speed reproduction, a predetermined area for recording the data used for the high-speed reproduction is provided. The error correction check code area provided on the track having the same azimuth as the track having no area and the area having the same height on the track are configured.

According to a fifth aspect of the present invention, a digital signal reproducing apparatus is capable of high-speed reproduction from a normal recording signal on an inclined track formed on the surface of a magnetic tape by a rotary drum having two types of azimuth heads mounted thereon. The signal used is extracted, the signal used for the high-speed reproduction is recorded in a predetermined area on the track, and the error correction is provided in the area adjacent to the predetermined area for recording the signal used for the high-speed reproduction on the track. In the check code area, at least one of two kinds of signals of error correction check code for high speed reproduction / error correction check code for normal reproduction is recorded and an identification signal for identifying these signals is recorded. A first data separating means for separating a signal used for the high speed reproduction from a reproduction signal at the time of high speed reproduction when reproducing the magnetic tape being recorded, Second data separating means for separating the error correction check code from the raw signal, identification signal separating means for separating the identification signal of the error check code, and error correction for decoding at least the error correction check code for high speed reproduction If the mode has a decoding means and the output of the identification signal separating means is a mode in which the error correction check code for high speed reproduction is recorded, the signal used for high speed reproduction and the error correction check code for high speed reproduction are used for high speed reproduction. Error-correction decoding is performed on the signal used for the high-speed reproduction to output a signal used for high-speed reproduction. The configuration is such that a high-speed reproduction signal is output without performing error correction decoding using a code.

A digital signal reproducing apparatus according to a sixth aspect of the present invention is used for high-speed reproduction from a normal recording signal on an inclined track formed on the surface of a magnetic tape by a rotary drum mounted with two types of azimuth heads. An error correction inspection provided in a region adjacent to a predetermined region on the track for recording a signal used for the high-speed reproduction and recording a signal used for the high-speed reproduction while taking out a signal In the code area, at least one of two kinds of signals of error correction check code for high speed reproduction / error correction check code for normal reproduction is recorded, and an identification signal for identifying these signals is recorded. When reproducing the magnetic tape, the data separation means for separating the error correction check code from the reproduction signal at the time of normal reproduction, and the error check code. Identification signal separation means for separating the identification signal and the error correction decoding means for decoding the normal reproduction error correction check code, and the output of the identification signal separation means records the normal reproduction error correction check code. If it is in the mode, the reproduction signal and the error correction check code for normal reproduction are used, the signal used for normal reproduction is subjected to error correction decoding, the normal reproduction signal is output, and the error correction check code for special reproduction is recorded. If the mode is set, the control is performed such that the reproduced signal is output without performing the error correction decoding by the error correction check code recorded in the error correction check code recording area.

[0029]

In the digital signal recording apparatus according to the first aspect of the present invention, when the digital signal is recorded on the inclined track formed on the surface of the magnetic tape by the rotary drum on which the two types of azimuth heads are mounted, There is provided at least an area for recording a normal recording signal, an area for recording data for high speed reproduction, and an area for recording an error correction check code. On the other hand, the digital signal input at the time of recording is recorded in the area for recording the normal recording signal, a signal used for high-speed reproduction is taken out from the input digital signal, and the signal used for high-speed reproduction is determined by the predetermined signal on the track. Record in the area for recording high-speed playback data. Further, an area for recording the error correction check code is provided in an area adjacent to an area for recording a signal used for the high speed reproduction, and at least the error correction check code for high speed reproduction /
One of two types of signals of the error correction check code for normal reproduction is recorded. Further, the signal recorded in the error correction check code area generates a signal for identifying one of the two types of signals and records it in a predetermined area on the track.

Further, in the digital signal recording apparatus according to the second aspect of the present invention, a signal for identifying one of the two types of signals is added to the ID signal in the recording signal or the sub-code area and recorded. To do.

In the digital signal recording apparatus according to the third aspect of the present invention, when the signal recorded in the error correction check code area is the error correction check code for high speed reproduction, the signal is recorded in the error correction check code area. The signal to be used is the error correction check code for high-speed reproduction and the predetermined fixed data. In the case of the normal reproduction error correction check code, the signal recorded in the error correction check code area is the normal reproduction error correction check code.

Further, in the digital signal recording apparatus according to the fourth aspect of the present invention, when the position where the error correction check code area is provided is a predetermined area on the track for recording the data used for the high speed reproduction. Is provided in an area adjacent to the area for recording the data used for the high speed reproduction. On the other hand, when the predetermined area for recording the data used for the high speed reproduction does not exist on the track, it is provided on the track having the same azimuth as the track for which the predetermined area for recording the data used for the high speed reproduction does not exist. An area for recording the error correction check code is provided at the same height on the track as the error correction check code area.

Further, in the digital signal reproducing apparatus according to the fifth aspect of the present invention, an inclined track formed on the surface of the magnetic tape is separated from a normal recording signal by a rotary drum on which two types of azimuth heads are mounted. A signal used for high-speed reproduction is recorded in a predetermined area on the track, and an error correction check code is provided in an area adjacent to a predetermined area for recording a signal used for high-speed reproduction on the track. At least one of two kinds of signals, that is, an error correction check code for high speed reproduction / an error correction check code for normal reproduction, is recorded in the correction check code area, and an identification for identifying these signals is provided. When reproducing a magnetic tape on which a signal is recorded, at the time of high-speed reproduction, the signal used for the high-speed reproduction from the reproduction signal and the error correction check code With separating, identifying the type of said error check code to detect the identification signal. When the error correction check code for high speed reproduction is recorded, the signal used for high speed reproduction and the error correction check code for high speed reproduction are used to perform error correction decoding on the signal used for high speed reproduction to obtain a high speed reproduction signal. If any other signal is recorded, the special reproduction data is output without performing error correction by the recorded error correction code of the error correction check code.

Further, in the digital signal reproducing apparatus according to the sixth aspect of the present invention, the normal recording signal is separated from the inclined track formed on the surface of the magnetic tape by the rotary drum on which the two types of azimuth heads are mounted. A signal used for high-speed reproduction is recorded in a predetermined area on the track, and an error correction check code is provided in an area adjacent to a predetermined area for recording a signal used for high-speed reproduction on the track. At least one of two kinds of signals of an error correction check code for high speed reproduction / an error correction check code for normal reproduction is recorded in the correction check code area, and an identification signal for identifying these signals When reproducing a magnetic tape on which is recorded, the area recorded with the error correction check code is separated from the reproduction signal during normal reproduction. To identify the type of said error check code to detect the identification signal. When the normal reproduction error correction check code is recorded, the reproduction signal and the normal reproduction error correction check code are used to perform error correction decoding on the reproduction signal and output the normal reproduction signal. If the signal is recorded, the normal reproduction signal is output without performing the error correction by the recorded error correction code of the error correction check code.

[0035]

【Example】

Example 1. FIG. 1 shows a digital V which is an embodiment of the present invention.
It is a block configuration diagram of a recording system of TR. In the figure, 1
01 is an input terminal of the transport packet. 10
5 is a TP header analysis circuit for detecting a transport header in the transport packet, 106 is a TP header correction circuit for correcting the transport header in the separated transport packet, 107 is a 1-bit bit of the transport packet De to convert to a stream
-Packet circuit 108 analyzes headers such as sequence headers and picture headers included in the bitstream, and performs frame or intra-field encoding (hereinafter,
It is referred to as intra coding. ) While separating the data,
The detected headers are added to the 4x speed data creation circuit 113 and the header addition circuit 1 in the 16x speed data creation circuit 112.
A header analysis circuit 109 for outputting to 10 outputs a high-speed reproduction speed (in the first embodiment, a quadruple speed, and 16 This is a special reproduction data creation circuit that generates and outputs special reproduction data at double speed.

110 is a special reproduction data creation circuit 109.
The header analysis circuit 10 is added to the 4 × speed output data.
A header adding circuit for adding necessary information (header information such as sequence header and picture header, and coding mode, quantization table information, etc.) from the respective headers output from 8; 111 is output from the header adding circuit 110 A Packet circuit for forming a transport packet of trick play data using the data to be reproduced, and a modified TP header adding circuit 112 for adding a modified transport header. The quadruple speed data creation circuit 113
P header correction circuit 106, header addition circuit 110, Pa
ccket circuit 111 and modified TP header addition circuit 1
12.

Reference numeral 114 is a 16x speed data creation circuit. Here, since the 16x speed data creating circuit 114 has the same configuration as the 4x speed data creating circuit 113, the detailed block diagram is omitted.

Reference numeral 180 converts the special reproduction data for 4 × speed and the special reproduction data for 16 × speed, which are input in the form of transport packets, into sync block formats (see FIG. 4, details will be described later). An EC for special reproduction in which an error correction check code for special reproduction (hereinafter referred to as C5 check code or simply C5 code) is added to this
The C circuit 181 converts the transport packet input from the input terminal 101 into the sync block format shown in FIG. 4B, and converts the data to which the error correction code is added by the ECC circuit for special reproduction 180. A data synthesizing circuit that synthesizes and arranges sync block data in a predetermined order.

Reference numeral 182 is a memory for temporarily holding the output from the data synthesizing circuit 181, and reference numeral 183 is a normal reproduction ECC for generating a normal reproduction error correction code (hereinafter referred to as C4 check code or simply C4 code). Circuit. 1
Reference numeral 84 indicates whether the recording mode of the error correction code at the time of recording is the special reproduction ECC recording mode or the normal reproduction EC according to an external input command signal or a preset mode.
The control signal indicating which of the error correction codes (the special correction error correction code and the normal reproduction error correction code) is to be recorded in the error correction code recording area described later is determined by the special reproduction. And an ECC control circuit for outputting to the normal ECC circuit 180, the data synthesizing circuit 181, the normal reproduction ECC circuit 186, and the digital modulating circuit 186. An ECC circuit 185 adds an error correction code (see FIG. 30) based on the SD standard to the data output from the memory 182. 186 is a digital modulation circuit,
Reference numeral 187 is a head amplifier, 188 is a drum, 189a and 189b are rotary heads, and 190 is a magnetic tape.

FIG. 2 is a block diagram of a trick play data creating circuit 109 which is an embodiment of the present invention. In the figure, 120 is an input terminal for inputting an intra data bit stream, 500 is a variable length decoder C for performing variable length decoding on the input bit stream, 501 is a counter C, and 502 is data for extracting data for quadruple speed. The sampling circuits A and 503 are data sampling circuits B that sample 16-times speed data. Reference numeral 127 is an EOB addition circuit A for adding an EOB (End Of Block) code to the special reproduction data for 4 × speed, and 128 is an EOB addition circuit B for adding EOB to the special reproduction data for 16 × speed. Reference numeral 129 is an output terminal for outputting special reproduction data for 4 × speed, and 130 is an output terminal for outputting special reproduction data for 16 × speed.

FIGS. 3A and 3B show the arrangement of rotary heads 189 (a) and 189 (b) on a typical rotary drum 188 used in the SD mode. The arrangement of the rotary head 189 shown in FIG.
It is described as × 2. Further, the rotary head 189 shown in FIG.
The arrangement is described as 2Ch × 1. FIG. 4 shows a data packet according to an embodiment of the present invention, and FIG. 4A is a transport packet diagram included in an input bitstream.
(B) is a recording data packet diagram recorded on the magnetic tape. The transport packet input from the input terminal 101 includes a digital video signal, a digital audio signal, and digital data relating to the video signal and the audio signal. These are the transport packet shown in FIG. It is divided into and transmitted. The packet consists of a 4-byte header part and 18
It consists of a 4-byte data section.

In the first embodiment, in order to record the input transport packet on the SD format recording track, two transport packets are converted into a recording data block of 5 sync blocks as shown in FIG. 4B. And record. In the figure, H1 is the first header, H2
Is the second header. 5 sync blocks (1
The data area in the sync block is composed of 77-byte data as shown in FIG. ), Identification data indicating the number of the sync) is recorded. Identification data such as video data or audio data is recorded in H2. In the first embodiment, the sync byte added to the head of the transport header added to the head of the transport packet may not be recorded. In the first embodiment, the description will be continued assuming that all the data in the transport packet is recorded.

FIG. 5 is a diagram showing the number of sync blocks that can be obtained from one track at each high reproduction speed. 9
What is the 000 rpm system? Fig. 3 (a) and Fig. 3
The system of the head arrangement shown to (b) is shown. In addition, each value in the figure is a sync that can be reproduced from one track at each reproduction speed when special reproduction is performed using a rotary head having a 10 μm (note that the track pitch in the SD standard is 10 μm). This shows the number of blocks. The calculation is performed assuming that the number of sync blocks in one track (corresponding to 180 degrees) is 186 sync blocks, and that a portion where the output level of the reproduction signal is higher than -6 dB can be obtained as in the conventional example.

FIG. 6 is a diagram showing the structure of a trick play data area which is an embodiment of the present invention. The details will be described later. FIG. 7 is a diagram showing the contents of data to be recorded in the special reproduction data area which is an embodiment of the present invention, and each special reproduction data area (including the error correction check code recording area of the first embodiment. ) Shows concrete data to be recorded. The details will be described later. FIG. 8 is a diagram showing a track pattern of a 4-track cycle including the arrangement of the special reproduction data area according to the embodiment of the present invention, which will be described in detail later. FIG. 9 is a diagram showing the arrangement of the 4-track cycle data shown in FIG. 8 on the magnetic tape 190.

The recording format of the first embodiment will be described below with reference to FIGS. In FIG. 6, reference numeral 150 denotes a B channel quadruple speed data recording area (including an error correction check code recording area) 151a to 151 for recording quadruple speed special reproduction data by the B channel head.
Reference numeral e denotes an A channel 16x speed data recording area (including an error correction check code recording area) for recording 16x speed special reproduction data by the A channel head.
2a and 152b are B channel error correction check code recording areas for recording error correction check codes. After that, A
A track recorded by the rotary head 189a of the channel is referred to as an A track, and a track recorded by the rotary head 189b of the B channel is referred to as a B track.

The number 1 added to each block in FIG.
The numbers 19 to 19 indicate the area numbers in the areas 150 to 152. The details of the data structure will be described later.

In FIG. 6, 150 data recording areas are composed of 34 sync blocks. The data recording area of 151a is composed of 6 sync blocks,
The data recording areas 151b to 151e are composed of 7 sync blocks. Reference numeral 152a is a data recording area composed of 5 sync blocks, and 152b is a data recording area composed of 4 sync blocks. The number of sync blocks assigned to each data recording area was determined based on the data shown in FIG. That is,
As shown in FIG. 5, 62 sync blocks can be obtained from one track during quad speed reproduction in the 9000 rpm system. Also, when playing back at 16x speed, 12
Sync block can be obtained. The data structure corresponding to each special reproduction speed constructed based on this is shown in FIG.

Further, FIG. 7 shows details of data contents recorded in each data area of FIG. Area 1 of the quad-speed reproduction data composed of 34 sync blocks shown in 150
5 sync block error correction check code recording area 1
(Hereinafter referred to as ECC1) is arranged, and 25 sync blocks of special reproduction image data recording area 2 (image 2) are arranged in area 2.
It is written. ) Is arranged, and an error correction check code recording area 3 (referred to as ECC3) of 4 sync blocks is arranged in area 3.

Of the 16 × speed reproduction data consisting of 6 sync blocks indicated by 151a, the special reproduction image data recording area 4 (referred to as image 4) is arranged in the area 4 and the error of 1 sync block in the area 5. A correction check code recording area 5 (referred to as ECC5) is arranged. further,
16 composed of 7 sync blocks 151b to 151e
Of the double speed reproduction data, the area 7, the area 10, the area 13, and the area 16, which are composed of 5 sync blocks, are sequentially recorded in the special reproduction image data recording area 7 (hereinafter referred to as the image 7) and the special reproduction image data recording. Area 10
An image data recording area 13 for special reproduction (hereinafter referred to as image 13) and an image data recording area for special reproduction 16 (hereinafter referred to as image 16) are arranged, each consisting of one sync block. Area 6, Area 8, Area 9,
The area 11, the area 12, the area 14, the area 15, and the area 17 are sequentially arranged in the order of error correction check code recording area 6 (hereinafter referred to as ECC6), error correction check code recording area 8 (hereinafter referred to as ECC8), and error correction check. A code recording area 9 (referred to as ECC9), an error correction check code recording area 11 (referred to as ECC11), an error correction check code recording area 12 (referred to as ECC12), and an error correction check code recording area 14 (referred to as ECC14). , Error correction check code recording area 15 (denoted by ECC 15) and error correction check code recording area 17 (denoted by ECC 17).

An error correction check code recording area 18 (referred to as ECC18) composed of 5 sync blocks is arranged in 152a, and an error correction check code recording area 19 (ECC19) composed of 4 sync blocks is arranged in 152b. ) Is placed. Note that error correction check codes (ECC1, ECC3) to be recorded in 150 areas, 151a-1
Error correction check code (ECC) to be recorded in the area 51e.
5, ECC6, ECC8, ECC9, ECC11, EC
C12, ECC14, ECC15, ECC17), and error correction check codes (ECC18, ECC19) recorded in the areas 152a and 152b are switched by the error correction code recorded by the control signal output from the ECC control circuit 184. To be

A method of recording an error correction code, which is one of the cores of the present invention, will be described below. As described in the conventional example, the ATV signal is compressed using a compression method based on motion compensation prediction. Therefore, when an error occurs in the reproduced data, the ATV signal has a problem that the error propagates to a plurality of fields or frames and is visually unsightly. Further, when the SD standard digital VTR is used as a storage medium for storing data such as a computer or a program, it may be a dropout caused by scratches on the tape or dust adhering to the magnetic tape. There is also a problem that it is desired to add a stronger error correction code to the data that has not been reproduced in order to restore it.

During special reproduction (high speed reproduction, slow reproduction, still reproduction, etc.), the rotary head 189 diagonally crosses the recording track, so that the reproduction signal is intermittently reproduced from each track. Therefore, during special playback, FIG.
It is not possible to construct an error correction block (video data) as shown in FIG. Therefore, during special reproduction, only the error correction by the C1 check code is applied to the reproduced data. At that time, C1
The error correction by the code has a problem that the reproduced image is often visually unsightly at the time of special reproduction because the error is frequently generated.

On the other hand, the amount of additional data that can be recorded on the magnetic tape 190 is limited as described in the conventional example.
Therefore, in the first embodiment, in order to effectively utilize the limited data area, the area to which the error correction code is added is arranged on the locus scanned by the rotary heads 189 (a) and 189 (b) during special reproduction. , When the user attaches importance to the image quality during normal reproduction, data is generated so that the error correction code is added to the normal reproduction data, and when the reproduction image quality during special reproduction is emphasized, error correction is performed on the special reproduction data. Data is generated so as to add a code.

As a result, the error correction code can be effectively added to the desired data within the limited data amount. When the digital VTR is used as a storage medium such as a computer, a powerful error correction code can be added in the same recording format. (The error correction code for normal reproduction is written in the error correction recording area.) The error correction check code recording areas (ECC18, ECC1) to be recorded in the areas 152a and 152b.
Regarding 9), when an error correction code is added to the data at the time of normal reproduction, the error correction check code for normal reproduction (C
In the case of recording 4 codes and adding an error correction code to the data at the time of special reproduction, fixed value data (for example, data in which all data are 0) is recorded. If it exists, it does not need to be fixed value data.). As a result, when the magnetic tape on which the error correction code for special reproduction is recorded is normally reproduced, since the data recorded in the above area is a fixed value, the error correction decoding during normal reproduction is performed. It is possible to slightly improve the error correction capability of the C2 code. (At the time of C2 decoding, the error correction capability can be improved because 9 symbols can be error-free.)

FIG. 8 shows an example in which each special reproduction data area is arranged on a track. At the left end of the figure, the data area recording area from the lower end to the upper end of the track based on the SD standard and its contents are shown. I from the bottom of the track
A TI area, an audio area, a video area, and a sub code area are arranged. Further, the scale shown in the figure indicates a sync block address (sync block number). As described above, the length of one track (corresponding to 180 degrees) is composed of data corresponding to 186 sync blocks.

In FIG. 8, reference numeral 160 denotes a first track recorded by the A channel head, and 161
Is a second track recorded by a B-channel head, 162 is a third track recorded by an A-channel head, and 163 is a fourth track recorded by a B-channel head. In the recording format of the first embodiment, data is recorded on the magnetic tape 190 by using the four tracks of the first track 160 to the fourth track 163 as one unit. In the drawing, f0, f1 and f2 shown on the lower side of the tracks indicate the types of pilot signals recorded on each track as reference signals for tracking during reproduction. Area 150, 151a ~
The input transport packet is recorded in the video areas on the tracks other than 151e, 152a, and 152b. (Hereafter, this area will be referred to as the main area.)

Also, 151a to 1a on the first track 160 and the third track 161 in the above four tracks.
Special reproduction data (image 4, image 7, image 10, image 13, and image 16) recorded in the area 51e.
In the figure, the same data is recorded in the areas marked with the same symbols. Regarding the area for recording the error correction code, when used as an area for recording the error correction check code for special reproduction, the same data is recorded on both tracks, but the error correction check code for normal reproduction is recorded. Needless to say, the same data is not recorded when used as an area for recording. Area 150 for 4x speed
During 4 × speed reproduction, one track can be reproduced by one scan of the rotary head 189 (b). Also, 16
In the double speed areas 151a to 151e, five areas can be reproduced from five tracks by one scan of the rotary head 189 (a) during 16 speed reproduction.

Note that there are 150 areas and 151a-1.
The error correction check code recorded in the area 51e is
When the data is added as the error correction code for special reproduction, the error is corrected to the special reproduction data by using these error correction check codes during special reproduction. On the other hand, data added as an error correction code for normal reproduction is ignored during special reproduction. Also, during normal playback,
When the signal recorded in the above area is data added as an error correction check code for normal reproduction,
Error correction is applied to the reproduced data using these error correction check codes. On the other hand, in the case of the data added as the error correction Kensa code for special reproduction, these data are ignored during normal reproduction. The details of the method of configuring the error correction check code during normal reproduction and special reproduction will be described later.

Further, the details will be explained in the reproducing system, but according to the data arrangement (recording format) of one unit shown in FIG. 8, the I shown in the figure at the time of 4 × speed reproduction and 16 × speed reproduction.
The rotary head 18 is used for the TI area and the subcode area.
9 (a) and 189 (b) scan. That is, during special reproduction, pilot signals f0, f1,
Tracking can be controlled using f2, and additional information such as time information and music number information recorded in the sub code area can be reproduced.

Data is recorded on the magnetic tape by repeating and recording one unit shown in FIG. FIG. 9 shows a recording format on the magnetic tape. In FIG.
The 4 × speed data recorded in the image 2 indicated by 150 is repeatedly recorded twice (see FIG. 9), and 151 a to 151
The 16 × speed data recorded in the image 4, the image 7, the image 10, the image 13, and the image 16 indicated by e is repeatedly recorded 8 times. That is, since the same data is recorded on two tracks in one unit (4 tracks) for 16 × speed data, the same data is repeatedly recorded 16 times. (The special reproduction data of 16x speed changes in a cycle of 32 tracks.) Further, the same data of 4x speed data is recorded twice. (The data for quadruple speed trick play changes in 8 track cycles.)

When the error correction code recorded in the error correction check code recording area is an error correction code for normal reproduction as described above, special reproduction for 4 × speed and 16 × speed in FIG. 7 is performed. C4 check codes for normal reproduction are recorded in the areas for recording the error correction check codes shown at both ends or one end of the data. At this time, the C4 check code for normal reproduction is recorded once. That is, in the error correction check code addition mode for normal reproduction, ECC1, ECC3, ECC5, EC in FIG.
C6, ECC8, ECC9, ECC11, ECC12,
ECC14, ECC15, ECC17, ECC18, E
The contents of the error check code for normal reproduction recorded in the CC 19 are all recorded only once without repeatedly recording the same data.

Next, with reference to FIGS. 10 to 14, normal reproduction,
The code structure of the error correction code used during special reproduction will be described. FIG. 10 is a diagram showing the structure of the error correction check code added to the normal reproduction data which is an embodiment of the present invention. In the first embodiment, in order to strengthen the error correction code (C4 code) at the time of normal reproduction, the interleaving depth of this C4 code is 10 tracks (138, 129, 10).
Reed-Solomon code is used. Note that the numbers in the vertical direction shown in the drawing show the sync block addresses when the C4 code is generated, and the numbers in the horizontal direction show the data addresses in one sync block.

FIG. 11A shows a specific arrangement of ATV data, trick play data, and error correction check code (C4 check code or C5 check code) on the A track. The arrangement of the ATV data and the C4 check code when the C4 code is generated is shown in FIG. C in the figure (c)
4 shows a specific arrangement of check codes. In FIG. 7D, special reproduction data when the C5 code is generated, and C
5 shows the arrangement of check codes. The specific arrangement of the C5 check code is shown in FIG. Similarly, FIG. 12A shows a specific arrangement of ATV data, special reproduction data, and error correction code (C4 check code or C5 check code) on the B track. The arrangement of the ATV data and the C4 check code when the C4 code is generated is shown in FIG. FIG. 7C shows the arrangement of special reproduction data and the C5 check code when the C5 code is generated.

In the first embodiment, as described above, the data is interleaved with a depth of 10 tracks to generate a C4 code. At that time, in the data synthesizing circuit 181, the input terminal 1
Transport packets input via 01 (see FIG.
(A)) is converted into sync block unit data shown in FIG. 4 (b). Then, the ATV signal converted into sync block units and special reproduction data output from the special reproduction ECC circuit 180 (note that special reproduction data is converted into sync block unit data in advance by the special reproduction ECC circuit 180). 11) by using FIG.
(B) or the block for generating the C4 code shown in FIG. 12 (b) is configured for each track unit. At that time, the C5 check code generated by the special reproduction ECC circuit 180 is stored at a predetermined address in the memory 182.

The recording data formed by each track unit in the data synthesizing circuit 181 is temporarily stored in the memory 182. When data for 10 tracks having the data structure shown in FIG. 11B or 12B is formed in the memory 182, the normal reproduction ECC circuit 182 is formed.
Then, the generation of the C4 code having the interleave depth of 10 tracks is started. The C4 code generation method will be described below with reference to FIG.

FIG. 13 shows a conceptual diagram of data interleaving according to the first embodiment. The interleaving method of the first embodiment is shown below. Here, the track number is Tn (0
≦ Tn ≦ 9), FIG. 11B, or the sync block number in the block configuration shown in FIG. 12B is SBn.
(0 ≦ SBn ≦ 137), and the data whose data number in the sync block is Dn (0 ≦ Dn ≦ 76) is D [T
n, SBn, Dn], in one embodiment of the shuffling shown in FIG. 13, (D [0,0,0], D [1,1,1], D [2,
2, 2], ..., D [(i mod 10), i
, (I mod 77)], ..., D [7,12
7,50], D [8,128,51], D [9,1
29,52], ..., D [7,137,60]). Here, D [0,0,0] to D [8,128,
129 bytes up to 51] are information symbols, D [9,1
The 9 bytes from 29,52] to D [7,137,60] are the C4 check code. FIG. 13 schematically shows the shuffling operation. Interleaving is performed by interleaving 10 tracks in the direction of the alternate long and short dash line.
The dotted line indicates the in-plane interleaving direction. (Actually,
Since interleaving is performed for every 10 tracks, one data is sampled for every 10 sync blocks. )

This operation is performed for all data in the sync block at the head of each track. That is, when the C4 code is generated with the k-th data starting from the sync block at the beginning of the j-th track, (D [j, 0, k], D [(j + 1 mod 1
0), 1, (k + 1 mod 77)], ..., D
[(J + i mod 10), i, (k + i mod 7)
7)], ..., D [(j + 128 mod 10),
128, (k + 128 mod 77)], D [(j +
129 mod 10), 129, (k + 129 mod)
d 77)], ..., D [(j + 137mod 1
0), 137, (k + 137 mod 77)]), k is changed from 0 to 76 per track, and this is applied to 10 tracks (j is changed from 0 to 9) to perform interleaving, and C4 is performed. Generate a check code. In addition, in FIG. 13 or in the above equation, (X mo
d Y) represents the remainder when the integer X is divided by the integer Y. The data for which the C4 code has been generated by the interleaving is read from the memory 182 so as to be recorded in a predetermined area shown in FIGS. 11 (a) and 12 (b). When the error check code addition mode is a mode in which the error correction check code is added to the special reproduction data, the C5 check code is recorded in the error correction check code recording area and the C4 code is discarded.

Next, the burst error correction capability of the C4 code will be described with reference to FIG. FIG. 14 is a diagram for explaining the burst error correction capability of the normal reproduction error correction check code according to the embodiment of the present invention.
(A) shows a recording area of the C4 check code on the A track, and (b) of FIG.
The position of the data reproduced from the A track is shown. Similarly, FIG. 7C shows the recording area of the C4 check code on the B track, and FIG. 7D shows the position of the data reproduced from the B track when the error correction by the C4 code is performed. . In each of the A track and the B track, data is sampled approximately every 10 symbols by interleaving of 10 tracks. Therefore, in the data arrangement of FIG. 14, up to 87 and 89 sync block burst errors can be corrected. As a result, the data can be restored by the C4 code even when the data of 80 sync blocks in one track has not been reproduced due to dropout during normal reproduction.

Next, the structure of the error correction code added to the special reproduction data and the arrangement of each data on the magnetic tape 190 will be described with reference to FIGS. 11, 12, and 15. FIG. 15 is a diagram showing the structure of an error correction check code added to special reproduction data according to an embodiment of the present invention. (Or later,
The data structure shown in FIG. 15 is referred to as an error correction block. )
As the error correction code (C5 code) added to the special reproduction data, the Reed Solomon code of (34, 25, 10) is used. FIG. 11D shows the arrangement of the 16x speed data to be recorded on the A track and the error correction code. The data of the error correction block shown in FIG. 15 is 5 for the 16 × speed reproduction data when recorded on the A track.
It is divided into sync blocks and recorded in respective areas shown in FIG. The error correction code is recorded in the error correction areas arranged in the sync blocks above and below the sync reproduction area for each sync block.

Similarly, the 4 × speed reproduction data recorded on the B track is recorded in the special reproduction area in units of 25 sync blocks. On the other hand, the error correction code is divided into four sync blocks in the first half and five sync blocks in the latter half and stored in error correction code recording areas provided with five sync blocks and four sync blocks above and below the special reproduction data recording area, respectively. To be done. Note that FIG.
The numbers written in the vertical direction in FIG. 12 indicate sync block addresses when forming the error correction code, and the numbers written in the horizontal direction indicate data addresses in one sync block.

Next, the operation of the recording system will be described with reference to FIGS. The transport packet input from the input terminal 101 is transmitted to the data synthesizing circuit 181 and T
It is input to the P header analysis circuit 105. The TP header analysis circuit 105 detects a transport header from the input transport packet. The detection results are the 4x speed data creation circuit 113 and the 16x speed data creation circuit 11.
4 and the ECC control circuit 184. on the other hand,
The transport packet in which the transport header is detected by the TP header analysis circuit 105 is de-Packet.
It is input to the circuit 107.

The de-packet circuit 107 performs parallel / serial conversion on the input transport packet and converts it into a 1-bit bit stream. de
-The bit stream data output from the Packet circuit 107 is input to the header analysis circuit 108. The header analysis circuit 108 detects headers such as a sequence header and a picture header from the input bitstream, and separates the intra-coded data. The intra data separated by the header analysis circuit 108 is input to the special reproduction data creation circuit 109.

The trick play data creating circuit 109 will be described in detail below with reference to FIG. (Note that MPEG2
Image compression by 8 lines × 8 pixels block (hereinafter,
It is referred to as a DCT block. ) To the discrete cosine transform (hereinafter,
It is referred to as DCT. ) Is performed, and the data subjected to DCT (hereinafter referred to as DCT coefficient) is read in a scanning order called zigzag scanning, and run-length coding with run of coefficient 0 (separated into run-length data and coefficient data). ), And then two-dimensional variable length coding is performed. ) The intra data input via the input terminal 120 includes the variable length decoder C500 and the data sampling circuit A50.
2 and the data sampling circuit B503.
The variable length decoder C500 performs variable length decoding on the input bit stream. In the first embodiment, the circuit size is reduced by not completely decoding the input bit stream at the time of variable length decoding, but detecting and outputting only the run length length and the code length of the variable length codeword. There is. (It goes without saying that variable length decoding may be performed completely.) The counter C501 counts the number of DCT coefficients in one DCT block decoded based on the run length length, and the data sampling circuit A502, And the count result is output to the data sampling circuit B503.

The data extracting circuit A502 extracts the variable length code word to be transmitted based on the count result output from the counter C501. The data extraction timing is controlled so that the number of decoded DCT coefficients output from the counter C501 is compared with a predetermined value and variable-length code words before the predetermined value are transmitted are transmitted. The break of the variable length code is detected by the code length information output from the variable length decoder C500. Similarly, the data sampling circuit B503 also samples data independently at preset timings (thresholds) based on the information output from the counter C501 and the variable length decoder C500. An EOB code is added to the extracted data by an EOB adding circuit A127 and an EOB adding circuit B128, and the data is output from an output terminal 129 and an output terminal 130, respectively.

At this time, the number of DCT coefficients for extracting data may be the same or different in each data extracting circuit. DCT to remove
The fact that the number of coefficients is different means that the number of DCT blocks recorded in the recorded trick play transport packet is different. The area in which special reproduction data can be recorded is limited as described above. Therefore, if the trick play data recording area has the same number of sync blocks for each trick play speed, 1D
If the number of recorded DCT coefficients in the CT block is increased, a special reproduction data recording area for recording is required, and the update cycle (hereinafter referred to as refresh) of the image data on the screen during reproduction at high speed reproduction is long. Become. The reproduction image quality is improved because more DCT coefficients are transmitted. On the contrary, 1
If the number of recorded DCT coefficients in the DCT block is reduced, the amount of special reproduction data per frame is reduced, and the special reproduction data recording area is reduced, so that the refresh of the reproduced image is shortened. The reproduced image quality is poor because the number of recorded DCT coefficients is small. The amount of data to be extracted at each double speed may be determined by the trade-off between refresh and image quality.

The special reproduction data for 4 × speed and the special reproduction data for 16 × speed output from the special reproduction data forming circuit 109 are respectively the 4 × speed data creating circuit 113 and the 16 × speed data creating circuit 114. Is input to. Subsequent processing is the same at each reproduction speed (4 × speed and 16 × speed), and therefore, the 4 × speed data creation will be described here. The quadruple speed data creation circuit 113 corrects the transport header based on the transport header information input from the TP header analysis circuit 105. Specifically, based on the intra data information output from the header analysis circuit 108, the header information indicating the continuity of the transport packet in the transport header of the transport packet that has transmitted the intra frame is rewritten. On the other hand, the header addition circuit 11
When 0, the header analysis circuit 10 is added to the special reproduction bit stream output from the special reproduction data creation circuit 109.
The header information such as the sequence header and the picture header detected in 8 and the information necessary for decoding the special reproduction data are added from each header. (Encoding mode flag, quantization table information, etc.)

The special reproduction data to which the header information is added is subjected to serial / parallel conversion in the packet circuit 111, and 1 byte is converted into 8-bit data. 8-bit data that has undergone serial / parallel conversion is 1
The data portion of the transport packet is configured by dividing the data into 84 bytes. In the serial / parallel conversion, “0” data is inserted before each header information so that each header information is composed of 4 bytes as defined by MPEG2. (Each header information is composed of 32 bits and needs to be composed of 4 bytes when a transport packet is generated.) Specifically, when the header information spans 5 bytes, the header information The header information is controlled to be composed of 4 bytes by adding "0" information to the front. Packet
The data of the 184-byte transport packet configured by the circuit 111 is transferred to the T
The transport header information output from the P header correction circuit 106 is added and output. The header information read from the TP header correction circuit 106 is Pac.
It is output based on the timing signal output from the ket circuit 111.

Here, the transport packetization of the 4x speed data has been described, but the same processing is performed on the 16x speed data. The special reproduction data for 16x speed output from the special reproduction data creation circuit 109 is input to the 16x speed data creation circuit 114. In the 16-fold data creation circuit 114, after the header addition circuit 110 adds each header and additional information based on the header information output from the header analysis circuit 108, the packet is added.
The circuit 111 performs serial / parallel conversion as described above to form the data portion of the transport packet, and the modified TP header adding circuit 112 adds the modified transport header, and the special reproduction ECC circuit 180 in the form of the transport packet. Is output to.

Now, the operation of the ECC control circuit 184 will be described. The ECC control circuit 184 determines the ECC mode for special reproduction or the ECC mode for normal reproduction in response to a command input from the user, and determines the type of the error correction check code to be recorded.
A data synthesis circuit 181, a normal reproduction ECC circuit 183,
And output to the digital modulation circuit 186,
A track identification signal having a 4-track cycle is also output based on the servo information output from the tape running control and the drum rotation control system. In the first embodiment, the error correction code is switched by the output of the memory 182.

4 × speed data creation circuit 113 and 1
Each trick play transport packet data output from the 6 × data creation circuit 114 is first collected by the trick play ECC circuit 180 into two transport packets, as shown in FIG. Converted to 5 sync block data. 5 as shown in FIG.
Twenty-five sync blocks of special reproduction data corresponding to each double speed number converted into sync block data are collected, and an error correction block is configured to add a C5 check code to the special reproduction data. Then, the C5 code is generated and added to the 4 × speed data and the 16 × speed data, respectively. The 4 × speed data and the 16 × speed data to which the C5 code is added are input to the data synthesizing circuit 181.

In the data synthesis circuit 181, the input terminal 10
A per transport packet input via 1
The TV signal is converted into the sync block format shown in FIG. 4B, and the converted ATV signal in sync block units and the special reproduction data output from the special reproduction ECC circuit 180 are combined to produce a signal shown in FIG. 11B. Alternatively, as shown in FIG. 12B, the ATV data and the special reproduction data are combined in units of one sync block. The identification of the tracks from the first track to the fourth track shown in FIG. 8 is performed based on the control signal output from the ECC control circuit 184. In addition, special playback ECC
The C5 check code generated by the circuit 180 is output together with the data configured in the above manner from the data synthesizing circuit 181 to the memory 182.
It is temporarily stored in the C5 code storage area provided in the memory 2.
In the memory 182, the data output from the data synthesizing circuit 181 is once written in a predetermined address in the memory.
It is assumed that the write address to the memory 182 and the control signal are output from the data synthesizing circuit 181.

Next, the operation of generating the C4 code will be described. The normal reproduction ECC circuit 183 performs the following operation on the data stored in the memory 182.
When the memory 182 has finished storing the data for 10 tracks, the normal reproduction ECC circuit 183 outputs the data read address for generating the C4 code and the control signal to the memory 182. The memory 182 reads out data based on the input control signal. (Note that the read data is interleaved with a depth of 10 tracks. That is, the read address output from the normal reproduction ECC circuit 183 has a depth of 10 tracks. Is assumed to have been interleaved in advance.) ECC circuit 183 for normal reproduction
Then, based on the data read from the memory 182, C4
Generate a code. The C4 code generated by the normal reproduction ECC circuit 183 is stored in the C4 code storage area provided in advance in the memory 182. C for 10 tracks
When the 4-code generation is completed, the data stored in the memory 182 is output to the ECC circuit 185.

Reading data from the memory 182 is E
This is performed based on the read address of the data output from the CC circuit 185 and the control signal. ECC circuit 18
5, the memory 182 is based on the mode signal output from the ECC control circuit 184 and the track identification signal.
The data stored therein is read in the order of the sync blocks shown in FIG. 11A or 12A. At that time, the ECC control circuit 184 selects the C4 code and the C5 code.
It is performed by the external input command signal input to.
(That is, the C5 code is read from the memory 182 at a predetermined timing in the special ECC mode, and the C4 code is read in the memory 18 in the normal reproduction ECC mode.
Read from 2 at a predetermined timing. )

The data read from the memory 182 is E
An error correction code based on the SD standard shown in FIG. 30 is added by the CC circuit 185. That is, the above-mentioned data recorded in the video area is first generated and added with the C2 check code for each track unit. For the data to which the C2 check code is added, a C1 check code is generated and added in sync block units. Further, the C3 check code and the C1 code are also added to the audio area. In addition, the first embodiment
Then, it is assumed that the audio data area is opened for future expansion, and the fixed value dummy data is recorded in the first embodiment. The data to which the error correction code based on the SD standard is added is read from the ECC circuit 185 at a predetermined timing for each track unit. At this time,
A track format based on the SD standard is generated. The generated data of the track format is
It is output to the digital modulation circuit 186.

In the digital modulation circuit 186, first, an ID signal is added to the head of each sync block. At that time, regarding the sync block recorded in the error correction code recording area, flag information for identifying the type of the error correction code is added to the ID signal. At the time of reproduction, the type of the error correction code is identified by the flag in the ID signal, and the error of each data is corrected. The data to which the ID signal is added is digitally modulated, amplified by the recording amplifier 187, and recorded on the magnetic tape 190 via the rotary heads 189a and 189b.

Next, the structure of the reproducing system of the digital VTR having the above recording format will be described. FIG.
FIG. 1 is a block configuration diagram of a reproducing system of a digital VTR which is an embodiment of the present invention. It is to be noted that the components designated by the same reference numerals as those in FIG. In the figure, 300 is a reproduction amplifier, 301 is a digital demodulator, 302 is reproduction data with a C1 check code,
And an ECC decoding circuit for correcting and detecting an error in the reproduction signal using the C2 check code, 303 is an input terminal of a mode signal (normal reproduction or special reproduction) indicating the current reproduction state, and 304 is an ECC decoding circuit The ECC control circuit switches the error correction decoding process during special reproduction or normal reproduction based on the ID signal output from 302 and the reproduction mode signal. 305 is a special reproduction memory that detects and stores a special reproduction signal from the data output from the ECC decoding circuit 302, and 306 is a normal reproduction memory that stores the data stored in the video area output from the ECC decoding circuit 302. It is a memory.

Reference numeral 307 denotes a control signal (ID detected by the ECC demodulation circuit 302) output from the ECC control circuit 304.
Based on the information discrimination result and the playback mode signal, etc.,
If the data stored in the special playback memory 305 is C
An ECC decoding circuit for special reproduction that performs error correction decoding using 5 codes, 308 is a control signal output from the ECC control circuit 304 (a discrimination result of ID information detected by the ECC demodulation circuit 302, a reproduction mode signal, etc.) Based on the above, the normal reproduction ECC circuit performs normal reproduction ECC decoding on the data in the normal reproduction memory 306 in the normal reproduction mode. 309, based on the control signal from the ECC control circuit 304, outputs the data in the special reproduction memory 305 in the special reproduction mode, and outputs the data in the normal reproduction memory 306 in the normal reproduction mode. And 310 is an output terminal.

Before explaining the operation of the reproducing system, FIG.
The digital VTR shown in the first embodiment using FIGS.
The operation when 4x speed reproduction and 16x speed reproduction are performed will be described. FIG. 17 is a diagram showing the relationship between the scanning locus of the rotary head and the track pattern when the magnetic tape having the recording format shown in FIG. 9 which is an embodiment of the present invention is reproduced at 4 × speed with the drum structure of 1 Ch × 2. . In the figure, the scanning locus denoted by A indicates the scanning locus of the rotary head of the A channel. Similarly, the scanning locus denoted by B indicates the scanning locus of the rotary head of channel B. (The arrow indicates the scan of the head during quadruple speed reproduction.) As described above, the special reproduction data for quadruple speed is recorded on the track of the B channel, and as described above, two units are repeatedly recorded (two locations). Since the same data is recorded in the recording area of the B channel), the A channel head scans one of the two units and the B channel head scans the other, as shown in FIG. The special reproduction data for quadruple speed recorded by the head can be reproduced. At this time, the head also scans the sub code area, and a signal of the sub code area can be obtained.
Also, tracking can be applied in the ITI area.

Similarly, FIG. 18 shows a magnetic tape having the recording format shown in FIG.
It is a figure which shows the scanning locus of a rotary head, and the relationship of a track pattern at the time of 4 times speed reproduction by the drum structure of hx1.
In the figure, the scanning locus denoted by A indicates the scanning locus of the rotary head of the A channel. Similarly, the scanning locus denoted by B is B
3 shows a scanning trace of a rotary head of a channel. (Arrow is 4
The following shows a scan of the head during double speed reproduction. As in the case of 1 Ch × 2, the special reproduction data for 4 × speed is recorded in the B channel, and 2 units are repeatedly recorded, so that the 2 Ch head always scans one of the 2 units. Therefore, it is possible to reproduce the special reproduction data for 4 × speed recorded by the head of the B channel.

FIG. 19 shows the relationship between the scanning locus of the rotary head and the track pattern when a magnetic tape having the recording format shown in FIG. 9 according to an embodiment of the present invention is reproduced at 16 × speed with a drum structure of 1 Ch × 2. It is a figure. In the figure,
The scanning locus marked A indicates the scanning locus of the rotary head of the A channel. Similarly, the scanning locus denoted by B indicates the scanning locus of the rotary head of channel B. (The arrow indicates the scan of the head during 16x speed reproduction.) The special reproduction data for 16x speed is repeatedly recorded on the A channel track in 8 units (the same data is recorded at 16 locations in total). As described in the conventional example, the 16-times speed data recorded by the A channel head can be reproduced. (As shown in FIG. 19, the special reproduction data for 16 × speed can be reproduced without fail by the rotary head 189 (a) of A channel.) At this time, the head scans the subcode area to obtain the signal of the subcode area. be able to. It should be noted that tracking can also be applied by the pilot signal recorded in the ITI area.

FIG. 20 shows the relationship between the scanning locus of the rotary head and the track pattern when the magnetic tape having the recording format shown in FIG. 9, which is an embodiment of the present invention, is reproduced at 16 × speed with a 2 Ch × 1 drum structure. It is a figure. In the figure,
The scanning locus marked A indicates the scanning locus of the rotary head of the A channel. Similarly, the scanning locus denoted by B indicates the scanning locus of the rotary head of channel B. (The arrow indicates the scan of the head during 16x speed reproduction.) Similar to the case of 1Ch × 2, the special reproduction data for 16x speed is repeatedly recorded for 8 units, so the 16x speed recorded by the A channel head is recorded. It is possible to reproduce the special reproduction data for. At this time, the head can scan the sub code area and obtain a signal of the sub code area. It should be noted that tracking can also be applied by the pilot signal recorded in the ITI area.

As shown in FIG. 5, the amount of data that can be reproduced from one track at the times of 4 × speed and 16 × speed is 62 SB at 4 × speed and 12 SB at 16 × speed. It should be noted that the reproduction positions of the data on the track for the −2 × speed reproduction and −14 × speed reproduction are the same as those for the 4 × speed and the 16 × speed reproduction, respectively, and therefore can be realized by the recording format shown in FIG. Therefore, in addition to special reproduction data, adjacent error correction code recording areas can be simultaneously reproduced during high-speed reproduction at each double speed. In addition, since the head scans all tracks during normal reproduction, all data recorded on the tracks can be reproduced. Therefore, the error correction code recording area can be reproduced in both high speed reproduction (4 × speed, 16 × speed reproduction, −2 × speed, and −14 × speed) and normal reproduction. It can be shared in the recording area. (That is, whichever error correction code is added, the above error correction check code can be reproduced during high speed reproduction or normal reproduction.)

In the above description, the tracking at high speed reproduction is performed in the ITI area, but the present invention is not limited to this. For example, in the case of 16 × speed reproduction, one data area of the special reproduction data recording area is used. May be used to detect and control the tracking phase, or the tracking phase may be detected and controlled in the plurality of special reproduction data recording areas. Further, regarding the 4 × speed reproduction, the tracking phase may be detected and controlled at a predetermined position of the adjacent A track. Further, the tracking phase may be roughly adjusted in the ITI area and finely adjusted in the special reproduction area. This is especially effective when there is a bend in the track due to compatible playback.

Next, the operation of the above reproduction system during normal reproduction will be described. Data reproduced from the magnetic tape 190 via the rotary heads 189a and 189b on the drum 188 is amplified by the reproduction amplifier 300 and input to the digital demodulation circuit 301. Digital demodulation circuit 3
At 01, data detection is performed from the input reproduction data, and after conversion into a reproduction digital signal, digital demodulation is performed. The reproduced digital data digitally demodulated in the digital demodulation circuit 301 is the ECC decoding circuit 30.
Entered in 2. When the reproduced digital signal is input, the ECC decoding circuit 302 separates the ID signal added to the head of each sync block, and outputs the result to the ECC control circuit 304. The reproduced digital data from which the ID signal is separated is corrected and detected by the ECC decoding circuit 302 by using the C1 check code and the C2 check code to correct an error generated during reproduction. The reproduced digital data that has undergone error correction in the ECC decoding circuit 302 is output to the special reproduction memory 305 and the normal reproduction memory 306. At that time, the special reproduction data reproduced from the special reproduction data recording area is stored in the special reproduction memory 305, and all the reproduction data output from the ECC decoding circuit 302 is the normal reproduction memory 306.
Is stored. In the first embodiment, during normal reproduction,
The error correction decoding operation using the C5 code in the trick-play ECC decoding circuit 307 is not performed. (That is, the trick play data is only written to the trick play memory 305, and no error correction decoding operation is performed.)

On the other hand, the ID signal detected by the ECC decoding circuit 302 is input to the ECC control circuit 304. ECC
In the control circuit 304, an ID separated from the sync block data recorded in the error correction code recording area
The signal is detected, the type of error correction code is identified using the added flag data, and the track number currently being reproduced is also detected during normal reproduction. Also,
The current reproduction mode is detected by the reproduction mode signal input via the input terminal 303. Then, the error correction code identification result, the track number, and the reproduction mode information are output to the special reproduction ECC decoding circuit 307 and the normal reproduction ECC decoding circuit 308, and the reproduction mode signal is supplied to the switch 309.

In the normal reproduction ECC decoding circuit 308, when the error correction code recorded in the error correction check code recording area is the normal reproduction error detection code, the track number information output from the ECC control circuit 304 is used. The error correction block in units of 10 tracks shown in FIG. Note that the 10-track interleaving at the time of decoding is performed at the time of controlling reproduction data read from the normal reproduction memory 306. The data subjected to C4 decoding is supplied to the output terminal 310 via the switch 309. On the other hand, when the error correction code recorded in the error correction check code recording area is the error detection code for special reproduction, the reproduction digital data is read out from the normal reproduction memory 306 as it is and output to the switch 309 without doing anything. To be done. The switch 309 is controlled to select the normal reproduction memory 306 during normal reproduction.

Next, the operation during special reproduction will be described. From magnetic tape 190 to rotary head 189 on drum 188
The data reproduced intermittently via a and 189b is amplified in the reproduction amplifier 300 and input to the digital demodulation circuit 301. The digital demodulation circuit 301 performs data detection from the input reproduction data, converts it into a reproduction digital signal, and then performs digital demodulation.
The reproduced digital data digitally demodulated in the digital demodulation circuit 301 is input to the ECC decoding circuit 302. When the reproduced digital signal is input, the ECC decoding circuit 302 separates the ID signal added to the head of each sync block, and the result is separated by the ECC control circuit 304.
Output to. The reproduced digital data from which the ID signal is separated is corrected and detected by the ECC decoding circuit 302 using the C1 check code to correct an error that has occurred during special reproduction. Since data is intermittently reproduced during special reproduction as described in the conventional example, the error correction block as shown in FIG. 30 or 10 cannot be formed. C4
No error correction by code shall be performed.

The reproduced digital data subjected to error correction in the ECC decoding circuit 302 is stored in the special reproduction memory 3
05 and the normal reproduction memory 306. At that time, the special reproduction data reproduced from the special reproduction data recording area is stored in the special reproduction memory 305.
Note that the reproduction data is not written in the normal reproduction memory 306 for the above reason.

As in the normal reproduction, the ECC decoding circuit 30
The ID signal detected in 2 is input to the ECC control circuit 304. The ECC control circuit 304 detects the ID signal separated from the sync block recorded in the error correction code recording area, identifies the type of the error correction code added to the ID signal, and detects the track currently being reproduced. The number is detected. Further, the current reproduction mode is detected by the reproduction mode signal input via the input terminal 303. The identification result of the error correction code, the track number, and the reproduction mode information are output to the special reproduction ECC decoding circuit 307 and the normal reproduction ECC decoding circuit 308, and the reproduction mode signal is supplied to the switch 309.

In the special reproduction ECC decoding circuit 307, if the error correction check code stored in the special reproduction memory 305 is data for normal reproduction, nothing is done and the reproduction data is read from the special reproduction memory 305 as it is. I will On the other hand, if the data is special reproduction data, the error correction block shown in FIG. 15 is configured to perform error correction by the C5 code on the special reproduction data stored in the special reproduction memory 305. The output of the special reproduction memory 305 is the switch 30.
9. The switch 309 is controlled so as to select the special reproduction memory 305 during special reproduction.

Since the digital VTR shown in the first embodiment is constructed as described above, the error correction code recording area provided in the recording track is recorded at a position where it can be read during normal reproduction and high speed reproduction. Therefore, the recording area of the error correction code can be shared, and the error correction code to be generated is switched according to the application, so that the area for recording the limited additional information can be effectively utilized, and in the future, When the digital VTR is used as an external device for recording data such as a computer, a powerful error correction code can be added to the data in the same recording format.

Further, since an error correction code is added according to the application, the error C is added when the reproduction image quality during special reproduction is emphasized.
By recording the 5 check code in the error correction check code recording area, the error correction capability during special reproduction is improved, and when the reproduction image quality during normal reproduction is emphasized, the C4 check code is usually recorded in the area. By improving the error correction capability of the reproduced data, it is possible to efficiently utilize the limited area on the magnetic tape, and in the future,
When the above digital VTR is used as an external storage device such as a computer, a powerful error correction check code can be added to the recorded data in the same recording format.
It can also be shared with external storage devices. Further, since the recording area on the recording track is used efficiently as described above, the amount of data that can be allocated to the special reproduction data is increased, and the reproduction image quality during special reproduction can be improved.

In the first embodiment, the case where the recording format is shown in FIG. 8 has been described, but the recording format is not limited to this format, and the special reproduction data is separated from the input data and stored in a predetermined area on the recording medium. In a digital signal recording / reproducing apparatus (digital VTR, digital disc player, etc.) having a recording format for recording, a system in which the error correction code recording area is provided adjacent to the special reproduction data recording area for recording Has the same effect.

Further, the depth of the interleave at the time of normal reproduction is not limited to 10 tracks, and P mainly in Europe is used.
In the AL area (frame frequency is 25 Hz), for example, 12
The depth of the track, the NTSC zone, and the interleave may be changed. Also in the NTSC area, 12 tracks or 1
It may be 5 tracks. Further, it goes without saying that the interleaving depth may be the same in the NTSC area and the PAL area. In addition, the interleaving method is shown in FIG.
Although shown in FIG. 13, it goes without saying that the present invention is not limited to this. For example, the direction of interleaving in the track may be vertical.

Further, it goes without saying that the recording data is not limited to the ATV signal, and the same effect can be obtained when a European DVB signal for compressing a video signal based on MPEG2 or a signal compressed by MPEG1 is recorded. Also, the reproduction speed at the time of high speed reproduction is not limited to 4 × speed and 16 × speed, and the special reproduction data recording area is arranged according to the reproduction speed required for the digital signal recording / reproducing apparatus, and the error The same effect can be obtained if the correction code recording area is provided adjacent to the special reproduction data recording area for recording.

In the first embodiment, the error correction check code area is provided adjacent to the special reproduction data recording area, but the present invention is not limited to this, and it is on the scanning locus of the rotary head 189 during high speed reproduction. Even if a dedicated area for recording the error correction check code is provided, the same effect can be obtained. Specifically, for example, in FIG. 8, the data for 16 × speed reproduction is reproduced on the tracks 160 and 162 at 151a to 151d.
, And the above error correction check code (error correction check code for special reproduction or normal reproduction) is arranged at 151e. In this case, the error correction check code is recorded 1
The size of the area 51e is, for example, 9 sync blocks. (Note that the recording area of the error correction check code recorded on the tracks 161 and 163 may be 6 sync blocks.) The minimum distance of the error correction check code may be determined by the size of the additional area. Good.

Example 2. In addition, 4x speed data area,
16x speed data area, ECC data area layout,
Yes, the number of areas is not limited to this. Also, the track cycle is not limited to the 4-track cycle. Also,
In the first embodiment, the 4 × speed or the 16 × speed is selected as one example of the high speed reproduction speed, but the present invention is not limited to this, and the rotary head 189 (a) may be used at other speeds as described above. , And 189 (b), a special reproduction data recording area and an error correction code recording area are provided on the scanning locus, and the error correction code to be recorded in this area can be switched according to the application. Play.

In the first embodiment, the error correction code stored in the error correction code recording area is switched according to the user's input command, but the invention is not limited to this. For example, in order to reduce the cost. , A digital VTR having only one of the error correction encoder and the decoder (the error correction code recording area has a structure for recording and reproducing only the error correction code added to the special reproduction data, or the above area). Even in the case of a digital VTR having a structure for recording and reproducing only the error correction code for normal reproduction, the magnetic tapes recorded by the respective digital VTRs are compatible with each other and the same effect can be obtained.

Further, it is a low-priced digital VTR which does not have an encoder for an error correction check code added to the error correction check code recording area and a decoder.
However, if a flag for identifying the above signal is recorded in, for example, an ID signal, compatibility with the above digital VTR can be achieved, and it is not necessary to determine a new recording format for low cost, and in the future, a computer will be used. Even when the above digital VTR is used as an external recording device such as the above, compatibility can be achieved.

Further, when performing the compatible reproduction using the above-mentioned three types of low-priced digital VTRs, an error correction decoder for decoding the error correction check code recorded in the error correction check code recording area is prepared. If not, it is needless to say that if the reproduction data is output without performing the error correction decoding using the error correction check code, the compatibility can be achieved as described above.

Example 3. Although the identification signal of the error correction check code is added to the ID signal in the first embodiment, the present invention is not limited to this. In the first embodiment, the subcode area is reproduced during high-speed reproduction. For example, in the recording format of the first embodiment, the subcode area can be reproduced during special reproduction. The same applies if an identification signal of an error correction check code, an error correction check code for high-speed reproduction, or a signal indicating a signal other than the error correction check code (for example, a signal of a predetermined fixed pattern) is recorded. Produce the effect of. At this time, there is almost no increase in the circuit scale. The identification signal may be added to both the ID signal and the subcode signal. In addition, it goes without saying that in the case of a standard in which an error correction code is always added, the identification flag need only switch between two signals.

Example 4. In addition, as shown in Example 1, C
By making the minimum distances of the 4-check code and the C5 check code the same, the encoder and the decoder of the error correction check code can be realized by adding some circuits, and the circuit scale can be reduced. . Specifically, at the time of decoding, a counter value setting circuit that counts the code length of the syndrome generation circuit, a selector circuit for setting the initial value of each register in the Chien search circuit, and a counter value setting that counts the number of chain searches All you need to do is add a circuit.
(As for the encoder, considering sharing with the decoder, it can be handled only by adding the above circuit.)

Example 5. Regarding the error correction check code recording area, when there is a track in which the special reproduction data is not recorded (the fourth track 163 shown in FIG. 8), the same azimuth in which the special reproduction data is recorded is recorded. The recording area of the error correction check code is provided at the same height as the error correction check code recording area provided on the track formed by the rotary head having the corners. (Fig. 8
The second track 161 shown in FIG. 4) makes it possible to make the burst error correction capability substantially uniform on tracks having the same azimuth angle, and to greatly simplify the control during interleaving during C4 code generation and reduce the circuit scale. ..
Although the circuit scale is slightly increased, a track having no special reproduction area is different from the error correction code recording area arranged on the track recorded at the same azimuth angle and having the special reproduction data recording area. It goes without saying that they may be arranged in areas (different heights).

[0114]

Since the present invention is constructed as described above, it has the following effects.

According to the digital signal recording apparatus of the first aspect of the present invention, when the digital signal is recorded on the inclined track formed on the surface of the magnetic tape by the rotary drum having the two types of azimuth heads mounted thereon, At least an area for recording a normal recording signal, an area for recording data for high-speed reproduction, and an area for recording an error correction check code are provided in the track. On the other hand, the digital signal input at the time of recording is recorded in the normal predetermined recording area, the signal used for high speed reproduction is taken out from the input digital signal, and the signal used for high speed reproduction is set in the predetermined area on the track. It is configured to record in. An area for recording the error correction check code is provided in an area adjacent to the predetermined area on the track for recording a signal used for the high speed reproduction, and an error correction check code area for recording the error correction check code is provided. In the error correction check code area, at least an error correction check code for high-speed reproduction /
A signal for recording any one of the two types of signals of the error correction check code for normal reproduction and a signal for recording in the error correction check code area for identifying one of the two types of signals. Is generated and recorded in a predetermined area on the track, the area for recording the error correction check code for high speed reproduction and the error correction check code for normal reproduction can be shared, and limited recording is possible. The area can be effectively used and the recording rate of the special reproduction data can be sufficiently secured, so that an excellent high-speed reproduction image can be obtained.

According to the second aspect of the digital signal recording apparatus of the present invention, a signal for discriminating between the two types of signals is added to the ID signal or the sub-code area in the recording signal. Since the recording is configured to be recorded, there is an effect that the error correction check code for high speed reproduction and the error correction check code for normal reproduction can be reliably discriminated with a simple circuit configuration.

According to the digital signal recording apparatus of the third aspect of the present invention, when the signal to be recorded in the error correction check code area is the error correction check code for high speed reproduction, the error correction check code area is written in the error correction check code area. The signal to be recorded is the error correction check code for high-speed reproduction, and the predetermined fixed data. When the error correction check code for normal reproduction is used, the signal to be recorded in the error correction check code area is for normal reproduction. Since the error correction check code is used as the error correction check code, the content of the area in which the fixed data is recorded is known at the time of error correction decoding, especially when the error correction check code for high-speed reproduction is recorded in the area. Since there is no need to perform error correction on this part, the error correction capability can be improved. Further, since the signal to be recorded is known in advance, there is an effect that the system control during reproduction does not break down.

According to the digital signal recording apparatus of the fourth aspect of the present invention, the position where the error correction check code area is provided has a predetermined area on the track for recording the data used for the high speed reproduction. In this case, the area for recording the data used for the high-speed reproduction is adjacent to the area. If there is no predetermined area for recording the data used for the high-speed reproduction on the track, the data used for the high-speed reproduction is recorded. Since the error correction check code area provided on the track having the same azimuth as the track in which the predetermined area does not exist and the area of the same height on the track are configured, the error correction check code can be formed with a simple circuit configuration. There is an effect that it is possible to determine and perform error correction decoding.

According to the fifth aspect of the digital signal reproducing apparatus of the present invention, a high speed recording from a normal recording signal is performed on an inclined track formed on the surface of a magnetic tape by a rotary drum having two azimuth heads mounted thereon. A signal used for reproduction is taken out, a signal used for high-speed reproduction is recorded in a predetermined area on the track, and an error correction check code is adjacent to a predetermined area for recording a signal used for high-speed reproduction on the track. In the error correction check code area provided in the area, at least one of two kinds of signals of the error correction check code for high speed reproduction / the error correction check code for normal reproduction is recorded, and these signals are identified. When a high-speed reproduction is performed on a magnetic tape on which an identification signal for With separating code, identifying the type of said error check code to detect the identification signal. When the error correction check code for high speed reproduction is recorded, the signal used for high speed reproduction and the error correction check code for high speed reproduction are used to perform error correction decoding on the signal used for high speed reproduction to obtain a high speed reproduction signal. If a signal other than that is output, the special reproduction data is output without performing error correction by the recorded error correction code of the error correction check code, so that other reproduction is performed by compatible reproduction or the like. Even when the data recorded by the digital signal recording device is reproduced, there is an effect that compatibility can be achieved and good high-speed reproduction can be performed. Further, the error correction check code recorded by sharing the area during high-speed reproduction and during normal reproduction is discriminated using an identification signal with a simple circuit configuration to perform error correction, and stable high-speed reproduction, and There is an effect that normal reproduction can be performed.

According to the sixth aspect of the digital signal reproducing apparatus of the present invention, a high speed recording from a normal recording signal is performed on an inclined track formed on the surface of a magnetic tape by a rotating drum on which two types of azimuth heads are mounted. The signal used for reproduction is taken out, the signal used for high-speed reproduction is recorded in a predetermined area on the track, and the signal used for high-speed reproduction is provided in an area adjacent to the predetermined area for recording the signal used for high-speed reproduction. At least one of two kinds of signals of an error correction check code for high speed reproduction / an error correction check code for normal reproduction is recorded in the error correction check code area and an identification signal for identifying these signals When reproducing the magnetic tape on which the Identifying the type of said error check code to detect the identification signal. If the identification result of the identification signal is the mode in which the normal reproduction error correction check code is recorded, the reproduction signal and the normal reproduction error correction check code are used to perform error correction decoding on the signal used for normal reproduction. If it is in the mode in which the special reproduction error correction check code is recorded, the normal reproduction signal is output and the reproduction signal is not subjected to error correction decoding by the error correction check code recorded in the error correction check code recording area. Since it is configured to control so as to output, it is possible to obtain compatibility even when reproducing data recorded by another digital signal recording device for compatibility reproduction, etc., and it is possible to perform good normal reproduction. . Also, the error correction check code recorded by sharing the area during high-speed reproduction and during normal reproduction is discriminated using an identification signal with a simple circuit configuration to perform error correction,
There is an effect that stable high speed reproduction and normal reproduction can be performed.

[Brief description of drawings]

FIG. 1 is a block configuration diagram of a recording system of a digital VTR which is an embodiment of the present invention.

FIG. 2 is a block configuration diagram of a trick play data creation circuit that is an embodiment of the present invention.

FIG. 3 is a head layout diagram of each channel on a typical rotary drum used in an SD standard digital VTR.

4A and 4B show data packets according to an embodiment of the present invention, FIG. 4A is a transport packet diagram of an input bitstream, and FIG. 4B is a record data packet diagram for recording on a magnetic tape.

FIG. 5 is a diagram showing the number of sync blocks that can be reproduced from one track at each high reproduction speed.

FIG. 6 is a diagram showing a configuration of a trick play data area according to an embodiment of the present invention.

FIG. 7 is a diagram showing the contents of data recorded in a trick play data area according to an embodiment of the present invention.

FIG. 8 is a diagram showing a track pattern of a 4-track cycle including an arrangement of a special reproduction data area according to an embodiment of the present invention.

FIG. 9 is a diagram showing the arrangement of the 4-track cycle data shown in FIG. 8 on a magnetic tape.

FIG. 10 is a diagram showing the structure of an error correction check code added to normal reproduction data according to an embodiment of the present invention.

FIG. 11 is a diagram showing an arrangement of data recorded on an A track, which is an embodiment of the present invention, and an error in one track when an error correction check code to be added to normal reproduction data and special reproduction data is generated. It is a figure which shows a correction block structure.

FIG. 12 is an arrangement of data recorded on a B track, which is an embodiment of the present invention, and an error within one track when an error correction check code to be added to normal reproduction data and special reproduction data is generated. It is a figure which shows a correction block structure.

FIG. 13 is a diagram for explaining an interleaving pattern of 10 tracks when generating an error correction check code for normal reproduction which is an embodiment of the present invention.

FIG. 14 is a diagram for explaining a burst error correction capability by an error correction check code for normal reproduction which is an embodiment of the present invention.

FIG. 15 is a diagram showing the structure of an error correction check code added to special reproduction data according to an embodiment of the present invention.

FIG. 16 is a digital VTR which is an embodiment of the present invention.
The block block diagram of the reproduction system of FIG.

FIG. 17 is a diagram showing the relationship between the scanning locus of the rotary head and the track pattern when the magnetic tape having the recording format shown in FIG. 9, which is an embodiment of the present invention, is reproduced at 4 × speed with a 1 Ch × 2 drum structure. is there.

FIG. 18 is a diagram showing the relationship between the scanning locus of the rotary head and the track pattern when the magnetic tape having the recording format shown in FIG. 9, which is an embodiment of the present invention, is reproduced at 4 × speed with a 2 Ch × 1 drum structure. is there.

FIG. 19 is a diagram showing the relationship between the scanning locus of the rotary head and the track pattern when a magnetic tape having the recording format shown in FIG. 9, which is an embodiment of the present invention, is reproduced at 16 × speed with a drum structure of 1 Ch × 2. is there.

FIG. 20 is a diagram showing the relationship between the scanning locus of the rotary head and the track pattern when a magnetic tape having the recording format shown in FIG. 9, which is an embodiment of the present invention, is reproduced at 16 × speed with a 2 Ch × 1 drum structure. is there.

FIG. 21 is a track pattern diagram of a conventional general home-use digital VTR.

FIG. 22 is a diagram showing a head scanning locus of the rotary head during normal reproduction and high-speed reproduction of the conventional digital VTR.

FIG. 23: Conventional digital VTR capable of high-speed reproduction
It is a block configuration diagram of.

FIG. 24 is a diagram showing an outline of a conventional digital VTR during normal reproduction and high-speed reproduction.

FIG. 25 is a head scanning locus diagram during general high-speed reproduction.

[Fig. 26] Fig. 26 is a diagram for describing an overlapping area at a plurality of conventional high-speed reproduction speeds.

FIG. 27 is a head scanning locus diagram of 5 × speed and 9 × speed in a conventional digital VTR.

FIG. 28 is a locus diagram of two head scans during 5 × speed reproduction in a conventional digital VTR.

FIG. 29 is a track layout diagram of a conventional digital VTR.

FIG. 30 is a data format diagram of a video signal recording area in one track of a video signal according to the SD standard.

FIG. 31 is a diagram showing the structure of one sync block in the SD standard.

[Explanation of symbols]

109 special reproduction data creation circuit circuit, 113 4 times data creation circuit, 114 16 times data creation circuit,
127 EOB addition circuit A, 128 EOB addition circuit B, 180 special reproduction ECC circuit, 181 data combination circuit, 182 memory, 183 normal reproduction ECC circuit, 184 ECC control circuit, 185 ECC circuit, 1
86 digital modulation circuit, 302 ECC decoding circuit,
304 ECC control circuit, 305 special playback memory,
306 normal reproduction memory, 307 special reproduction ECC decoding circuit, 308 normal reproduction ECC decoding circuit, 309
Switch, 500 Modulatable decoding C, 501 Counter C, 502 Data sampling circuit A, 503 Data sampling circuit B.

Claims (6)

[Claims] 1. A signal used for high-speed reproduction is extracted from a normal recording signal on an inclined track formed on the surface of a magnetic tape by a rotary drum on which two types of azimuth heads are mounted, and a signal used for the high-speed reproduction is output on the track. And an error correction check code area for recording an error correction check code in an area adjacent to the predetermined area on the track for recording a signal used for the high speed reproduction. A means for generating and recording at least one of two kinds of signals of an error correction check code for high speed reproduction / an error correction check code for normal reproduction in the check code area, and recording in the error correction check code area And a means for generating an identification signal for identifying one of the two types of signals, and recording the identification signal in a predetermined recording area. Digital signal recorder. 2. A digital signal recording apparatus according to claim 1, wherein a signal for discriminating one of the two types of signals is added to an ID signal in the recording signal or a subcode area and recorded. . 3. When the signal recorded in the error correction check code area is the error correction check code for high speed reproduction, the signal recorded in the error correction check code area is the error correction check code for high speed reproduction, and 2. Fixed fixed data, and in the case of the normal reproduction error correction check code, the signal recorded in the error correction check code area is the normal reproduction error correction check code. Item 2. A digital signal recording device according to item 2. 4. The position where the error correction check code area is provided is adjacent to the area for recording the data used for the high speed reproduction when a predetermined area for recording the data used for the high speed reproduction exists on the track. If the predetermined area for recording the data used for the high speed reproduction does not exist on the track, the area is provided on the track having the same azimuth as the track for which the predetermined area for recording the data used for the high speed reproduction does not exist. 3. The digital signal recording apparatus according to claim 1 or 2, wherein the error correction check code area and the area having the same height on a track are provided. 5. A signal used for high-speed reproduction is extracted from a normal recording signal on an inclined track formed on the surface of a magnetic tape by a rotary drum mounted with two types of azimuth heads, and the signal used for the high-speed reproduction is described above. At least an error correction check code for high-speed reproduction is recorded in a predetermined area on the track and in an error correction check code area provided in an area adjacent to the predetermined area for recording a signal used for high-speed reproduction on the track. In a digital signal reproducing apparatus for recording one of two kinds of signals of an error correction check code for normal reproduction and reproducing a magnetic tape on which an identification signal for identifying these signals is recorded, At the time of high speed reproduction, a first data separating means for separating the signal used for the high speed reproduction from the reproduction signal and the error correction detection from the reproduction signal. A second data separation means for separating the check code, an identification signal separation means for separating the identification signal of the error check code, and an error correction decoding means for decoding at least the error correction check code for high speed reproduction, If the output of the identification signal separating means is a mode in which the error correction check code for high speed reproduction is recorded, the signal used for the high speed reproduction,
And a mode in which the error correction check code for high speed reproduction is used to perform error correction decoding on the signal used for high speed reproduction to output the signal at the time of high speed reproduction, and the error correction check code for normal reproduction is recorded. Digital signal reproduction comprising an error correction decoding control means for controlling so as to output a signal at high speed reproduction without performing error correction decoding by the error correction check code recorded in the error correction check code recording area. apparatus. 6. A signal used for high speed reproduction is extracted from a normal recording signal on an inclined track formed on the surface of a magnetic tape by a rotary drum on which two types of azimuth heads are mounted, and the signal used for the high speed reproduction is described above. At least an error correction check code for high-speed reproduction is recorded in a predetermined area on the track and in an error correction check code area provided in an area adjacent to the predetermined area for recording a signal used for high-speed reproduction on the track. In a digital signal reproducing apparatus for recording one of two kinds of signals of an error correction check code for normal reproduction and reproducing a magnetic tape on which an identification signal for identifying these signals is recorded, At the time of normal reproduction, the data separation means for separating the error correction check code from the reproduced signal and the identification signal of the error check code are separated. An identification signal separating means and at least an error correction decoding means for decoding the error correction check code for normal reproduction are provided, and the output of the identification signal separation means is in a mode in which the error correction check code for normal reproduction is recorded. For example, using the reproduction signal and the error correction check code for normal reproduction,
In a mode in which a signal used for normal reproduction is subjected to error correction decoding and a normal reproduction signal is output, and an error correction check code for special reproduction is recorded, the error correction check recorded in the error correction check code recording area is performed. A digital signal reproducing apparatus having an error correction decoding control means for controlling so as to output a reproduced signal without performing error correction decoding by a code.