JPH0638167A - Method and device for digital video signal recording and reproducing - Google Patents

Abstract

PURPOSE:To obtain an excellent speed search pattern from the digital video signal recording and reproducing device dividing a video signal of one field into plural blocks and recording and reproducing the video signal to/from plural tracks. CONSTITUTION:A recording signal by one field divided into 5 segments is inputted to a shuffling-circuit 20, the replacement of sequence of the segments is implemented in one field, the signal is divided into two channels by a recording processor 8 and recorded on a magnetic tape 1 by magnetic heads 9a, 9b. A reproduction signal reproduced by magnetic heads 10a, 10b at a double speed search is synthesized into a reproduced digital signal by one field by a reproducing processor 11 and the result is fed to a de-shuffling circuit 21, in which segments of each field are restored the original sequence.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital video signal recording / reproducing apparatus (hereinafter referred to as a digital VTR) for recording / reproducing a digital video signal using a rotary head.

[0002]

2. Description of the Related Art Conventionally, in order to record and reproduce a wide-band video signal such as a high-definition signal using a small-diameter drum, for example, a high-definition VTR recording technology (Journal of Precision Engineering, Vol. 7.7.5)
There is also known a method in which a video signal of one field is divided into a plurality of segments and recorded on a plurality of tracks, as described in "1.

Further, a digital V for converting a video signal into a digital signal and recording / reproducing using a drum having a small diameter.
Even in TR, if the digitized video signal is recorded as it is, the bit rate of the recording signal becomes high. Therefore, as in the previous HDTV VTR, one-field video signal is distributed to a plurality of channels, and this is divided into a plurality of channels. A method of recording on a plurality of tracks by a magnetic head has been considered.

For example, as shown in FIG. 15, a method in which a video signal of one field is divided into five segments and recorded on 2.5 tracks (5 tracks / 1 frame) on a magnetic tape can be considered. , FIG. 15, FIG. 16 and FIG.
7, the recording method and the normal reproducing operation will be described in detail with a digital VTR having a recording format of 5 tracks / 1 frame as an example.

Here, FIG. 16 is a diagram showing scanning loci of the magnetic head on the tape at the time of recording and reproducing, and FIG. 17 shows an example of the configuration of the recording system and the reproducing system of the present digital VTR. It is a figure.

In FIG. 17, 1 is a magnetic tape, 2 is a video signal input terminal, 3 is an A / D converter for converting an analog signal into a digital signal, 4 is a high efficiency encoder for compressing and coding a video signal, 5 is an error correction encoder for adding an error correction code, 6 is a modulator for converting a recording signal into a code suitable for a transmission path, 7 is a modulator for converting a recording signal for one field into a signal suitable for the transmission path, Reference numeral 7 is a segment divider that divides a recording signal for one field into five segments as shown in FIG. 15, and 8 is two magnetic heads 10a, 1 which will be described later on the recording information divided into five segments.
In order to perform recording using 0b, a recording processor that controls to divide into two channels, 9a and 9b are magnetic heads for recording, 10a and 10b are magnetic heads for reproducing, and 17 is a rotary drum.

Reference numeral 11 is a reproduction processor for synthesizing reproduction information of five segments supplied from 10a and 10b into a digital signal for one field, 12 is a demodulator for demodulating the digital signal into an original digital signal, and 13 is transmission. An error correction decoder for detecting and correcting errors, 14 is a high efficiency decoder for expanding a compressed video signal into an original signal, 1
Reference numeral 5 is a D / A converter for modulating a digital video signal into an analog video signal, and 16 is an output terminal for the video signal.

Next, the operation of the recording system will be described. The video signal input from the input terminal 2 is converted into a digital video signal by the A / D converter 3, and the high efficiency encoder 4
Is output to. The high-efficiency encoder 4 compresses information by utilizing the correlation of video information. The output of the high efficiency encoder 4 is input to the error correction encoder 5, and an error correction code for correcting a transmission error in recording and reproduction is added. The data to which the error correction is added is converted into a recording signal suitable for the magnetic head and the magnetic tape by the modulator 6, and the recording information for one field is divided into five segments by the segment divider 7 as shown in FIG. To be done.

The recording signal divided into five segments is input to the recording processor 8, divided into two channels, and then recorded on the magnetic tape 1 by the magnetic heads 9a and 9b. The magnetic heads 9a and 9b are the rotary drum 1
7, the magnetic heads 9a and 9b also rotate when the rotary drum 17 rotates, and as shown in FIG. 16, the magnetic tape 1 is simultaneously moved by the magnetic heads 9a and 9b by a so-called helical scan method. Recording is done.

Taking the case of scanning [1] as an example, the data of segment 1 and segment 2 is recorded on one track by the magnetic head 9a in the order of segment 1 and then segment 2. Then, by the magnetic head 9b, the data of the segment 3 and the segment 4 are
The data of the segment 3 and then the data of the segment 4 are recorded on one track in this order.

In this way, the magnetic heads 9a and 9b similarly perform the scanning [2] to the scanning [5].
Recording is performed, and thereafter, the operations of scanning [1] to scanning [5] are repeated.

Next, the operation of the reproducing system will be described. The magnetic heads 10a and 10b are also mounted on the rotary drum 17 like the magnetic heads 9a and 9b.
The magnetic heads 10a and 10b also rotate due to the rotation of the magnetic disk 7, and at the same time, the tracks are scanned to supply the reproduction signal to the reproduction processor 11.

Taking the scan [1] in FIG. 16 as an example,
The magnetic head 10a causes the segment 1 and the segment 2
Data is reproduced in the order of segment 1 and then segment 2. Then, the magnetic head 10b reproduces the data of the segment 3 and the segment 4 in the order of the data of the segment 3 and then the data of the segment 4.

The reproduction processor 11 combines the data reproduced as described above into a digital signal for one field, and outputs the digital signal to the demodulator 12.

The demodulator 12 demodulates the digital signal into the original digital signal, the error correction decoder 14 performs error detection and error correction, and the high-efficiency decoder 14 converts the original signal from the compressed code. It becomes a digital video signal. The restored digital video signal is D / A
In the converter 15, converted into an analog video signal,
It is output by the output terminal 16.

Next, in the case of the speed search of the double speed of this digital VTR, FIG. 18, FIG. 19, FIG.
This will be described with reference to FIGS. 21, 22, and 23.

FIG. 18 is a diagram showing the scanning loci of the magnetic heads 10a and 10b in the case of the speed search at the double speed of the present digital VTR.

In the case of the speed search of 2 × speed, the head scanning locus is generally as shown by the hatched portion in FIG. 18. However, when about half the track width is reproduced, it is almost due to the error correction processing or the like. Since the data is completely restored, the shaded portion in FIG. 19 can be reproduced as a result, and the reproduction is performed by the magnetic heads 10a and 10b every two tracks.

FIG. 20 is a diagram showing an example of the relationship between the segment and the screen. Here, the case of segment 1 and segment 4 is shown, and the lower half of the segment corresponds to the left screen, and the upper half of the segment corresponds to the right screen of the screen.

Further, FIG. 21 shows a head scanning locus when a speed search at double speed is performed on the magnetic tape on which the video information is actually recorded. As described above, in the case of normal reproduction, information for one field can be obtained with 2.5 tracks. This is also the case during special playback, and in the case of double speed search, there are four patterns in which video information for one field, that is, video information for 2.5 tracks can be obtained. In FIG. 21, hatching types are shown as pattern 1 to pattern 4. In the field number, the above four patterns are repeated in the period from field 0 to field 7. Hereinafter, the description of the speed search at double speed will be made by using 8 fields and 4 patterns as a basic unit.

First, taking pattern 1 as an example, the video information for 2.5 tracks is the data of segment 1, segment 2, segment 3, segment 4 of field 0, and segment 4 of field 1 and segment 1 of field 2. The lower half of each.

At this time, in pattern 1, the information of segment 1 and segment 4 of field 0 and the information of segment 1 and segment 4 of field 1 are shown in the lower half of the segment, that is, shown in FIG. As in the left part of the segment overlaps.

Therefore, the magnetic heads 10a and 1a are displayed on the screen.
The data corresponding to the left screen of segment 1 of field 2 and segment 4 of field 1 which 0b has reproduced later is reproduced by the reproducing processor 11 first by the magnetic heads 10a, 1
0b is output in such a manner that the reproduced data of the left screen of segment 1 and segment 4 of field 0 is reproduced.

Similarly, in each of the patterns 2 to 4, the segment information in the scanning locus area surrounded by the hatched portion is detected as the screen information of one field.

In this way, pattern 1 to pattern 4
The 1-field digital signals up to are output to the demodulator 12 and demodulated to the original digital signals. And
The error correction decoder 14 performs error detection and error correction, and the high efficiency decoder 14 converts the compressed code into the original digital video signal. The restored digital video signal is converted into an analog video signal in the D / A converter 15. Then, the output terminal 16 outputs a double speed speed search screen.

FIG. 22 shows at which position on the screen of patterns 1 to 4 the information of which field is reproduced. The numbers in the figure indicate the field numbers, and the crosses indicate that the scanning of the corresponding segment within one pattern was impossible.

As shown in FIG. 22, in the case of the speed search of double speed, four patterns of pattern 1 to pattern 4 are repeated, so that the portion marked with X becomes a fixed error and appears on the reproduction screen.

Further, FIG. 23 shows an example in which, in the case of the speed search of double speed, reference fields are set in four patterns respectively and the difference between the fields of the reproduced segment with respect to the reference field is represented by the number of fields. It is possible to judge whether a natural screen is being reproduced.

In FIG. 23, for example, in the case of pattern 3, the reference field is field 4, the data of one field ahead is reproduced in segment 2, and the data of one field before in segment 3 is reproduced in the right screen. 1
An image that is unnatural in time, such as the data after the field is reproduced.

[0030]

Since the conventional digital VTR for dividing the video signal of one field into a plurality of segments and recording it on a plurality of tracks is constructed as described above, during the speed search, one field There is a problem that it is very unsightly because a part that is not always reproduced occurs and a fixed error occurs on the screen.

Further, in the above digital VTR, the video signal of one field is divided into a plurality of segments and recorded on a plurality of tracks. Therefore, at the time of speed search, there is a time difference between the screens of one field. Since there is a part that can be formed, there is a problem that it is very unsightly.

The present invention has been made to solve the above-mentioned problems, and it is possible to eliminate a fixed error on the screen at the time of speed search and reduce a time difference portion on the screen of one field. Therefore, a natural speed search screen can be obtained.

[0033]

A digital video signal recording / reproducing apparatus according to a first aspect of the present invention includes a block dividing means for dividing a recording video signal of one field or one frame into a plurality of blocks at the time of recording, and at the time of recording. Swap the block recording order in a predetermined order so that the re-screen product on the field or frame corresponding to the divided block played when performing special playback at a different specific speed becomes the maximum Means, a reproduction signal synthesizing means for synthesizing blocks reproduced during normal reproduction and special reproduction into a reproduction video signal for one field, and a reproduction order of the blocks of the reproduction video signal for one field. A block reproduction order changing means for changing the order is provided.

The digital video signal recording / reproducing apparatus according to the second invention of the present application is 1 field or 1 field at the time of special reproduction.
It is characterized in that a block at the same position on another field or a frame is selected and a reconstructing process is performed so that a time difference with another block in the frame is minimized.

In the digital video signal recording / reproducing apparatus of the third invention of the present application, data that belongs to a visually prominent position such as the center of the screen in the field or frame is assigned to a block that can be stably reproduced during special reproduction, and reproduction is impossible. For example, data belonging to a visually inconspicuous position such as a screen edge is assigned to an unstable block.

[0036]

In the digital video signal recording / reproducing apparatus of the first aspect of the present invention, when performing special reproduction such as speed search, the screen area can be reproduced to the maximum extent, so that a reproduction error screen area can be minimized. You can get the playback screen.

In the digital video signal recording / reproducing apparatus of the second aspect of the invention, when performing special reproduction such as speed search, the screen area of one field is reproduced to the maximum extent, and the non-reproduced portion or conversely the reproduced portion is reproduced. In the other portion, the temporally unnatural portion is interpolated by selecting another field closest in time, so that a natural special reproduction screen can be obtained.

In the digital video signal recording / reproducing apparatus of the third aspect of the invention, when performing special reproduction such as speed search, the screen area of one field is reproduced to the maximum extent, and the non-reproduced portion or conversely, the duplicated portion is reproduced. Even if you perform an operation such as interpolating by selecting another field that is closest in time to a part that is unnatural in time, a particularly unnatural part that remains on the screen can be viewed on the screen. Since it can be arranged in a position that is not noticeably noticeable, a more natural and better speed search screen can be obtained.

[0039]

EXAMPLES Example 1. An embodiment of the present invention will be described below with reference to FIGS.
This will be described with reference to FIG. First, a recording method and a normal reproducing operation of a digital VTR according to an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a block diagram of a recording system and a reproducing system of a digital VTR according to an embodiment of the present invention. In FIG. 1, reference numerals 1 to 17 are the same as those of the conventional example shown in FIG. , And detailed description thereof will be omitted.

Reference numeral 20 denotes a shuffling circuit for changing the recording order of the divided segments in one field by the segment divider 7, and 21 denotes the order of the changed segments originally reproduced by the shuffling circuit 20 at the time of reproduction. It is a de shuffling circuit that returns to the order of.

FIG. 2 shows an example of the shuffling for changing the order of the segments in the field and the deshuffling for returning the order of the segments to the original order according to the embodiment of the present invention.

FIG. 3 is a diagram showing an example of the recording format of the digital VTR of the present invention. FIG. 4 is a diagram showing scanning loci of the magnetic head on the magnetic tape during recording and reproduction of the digital VTR of the present invention.

First, the operation of the recording system will be described with reference to FIG. Similar to the conventional example, the video signal input from the input terminal 2 is converted into a digital video signal in the A / D converter 3 and output to the high efficiency encoder 4.
The high-efficiency encoder 4 compresses information by utilizing the correlation of video information. The output of the high efficiency encoder 4 is input to the error correction encoder 5, and an error correction code for correcting a transmission error in recording and reproduction is added. The data to which the error correction code is added is converted into a recording signal suitable for the magnetic head and the magnetic tape in the modulator 6, and the recording signal for one field is converted into 5 by the segment divider 7 as in the conventional example.
It is divided into two segments.

The recording signal for one field divided into five segments is input to the shuffling circuit 20.

In the shuffling circuit 20, for example, as shown in FIG. 2, the order of the segments is changed within one field.

Here, an example of a procedure for determining the segment replacement order shown in FIG. 2 will be described with reference to FIGS. 10 and 11. FIG. 10 shows a head scanning locus when a speed search of double speed is performed on the magnetic tape, and symbols A to E are attached instead of the segment numbers. Further, for convenience, the field 0, the field 2, the field 4, and the field 6 are EVEN fields, and the field 1, the field 3, the field 5, and the field 7 are ODD fields. Further, FIGS. 11 and 12 are diagrams specifically showing the procedure for determining the order of replacing the segments. The order of replacing the segments is determined based on the scanning conditions of the head scan patterns 1 to 4 during the speed search at double speed. Is to determine. In other words, each of the patterns 1 to 4 corresponds to the video information for one field, and scanning as many segments as possible in each pattern can obtain a good double speed speed search screen. It connects.
For example, the placement of the segment of the EVEN field is A
= 1, B = 2, C = 3, D = 4, E = 5, and O
A method of determining the order of replacing the segments of the DD field will be described here.

First, the pattern 1 will be described. As shown in FIG. 10 and FIG. 11, the head scanning condition of pattern 1 is as follows: EVEN field segments A, B, C, D
, And the lower half of segment A is scanned, and the lower half of segment D of the ODD field is scanned. here,
Since the segments of the EVEN field are allocated as described above, in the pattern 1, the information of the segments 1 to 4 has already been obtained only by scanning the EVEN field. Therefore, in order to obtain the information for one field in the pattern 1, it is not necessary to assign the segments 1 to 4 to the segment D of the ODD field, and the information of the segment 5 which cannot be obtained only by scanning the EVEN field is obtained. Must be assigned. Therefore, in FIG. 11, segments 1 to 4 in the column of segment D of the ODD field
Is marked with a cross.

The pattern 2 will be described. As shown in FIGS. 10 and 11, the head scanning condition of pattern 2 is such that the lower half of the segment A of the EVEN field and the entire segment B are scanned, and all of the segments B, D, E and the segment D of the ODD field are scanned. Half is scanned. Here, since the segments of the EVEN field are similarly allocated as described above, in the pattern 1, information on the upper half of the segment 1 and the segment 2 is obtained only by scanning the EVEN field. Therefore, in order to obtain information for one field in the pattern 1, it is not necessary to assign the segments 1 and 2 to the segments B, D, and E of the ODD field.
It is necessary to assign the information of the segments 3, 4, 5 which could not be obtained only by scanning the field. Therefore, FIG.
1, the ODD field segments B, D, E
Segments 1 and 2 in the column are marked with x.

In a similar procedure, pattern 3 in FIG.
Also for pattern 4 as well, unnecessary segment numbers are selected for the segments A, B, C, D, and E of the ODD field, and a cross mark is marked. FIG. 13 is a diagram in which the X marks of the above patterns 1 to 4 are overlapped, and from this figure, the EVEN field is A = 1, B = 2, C =
When 3, D = 4 and E = 5, the arrangement of the segments of the ODD field can be a combination of A = 1 or 2 B = 3 or 4 C = 1 or 2 D = 5 E = 3 or 4.

Based on this combination, the order of segment replacement is determined so that the number of ODD field segments that cannot be scanned is reduced as much as possible during the speed search at double speed. For example, A = 1, B = 3, C =
2, D = 5, E = 4 and so on.

In this embodiment, based on such a method,
A case of changing the order of the segments as shown in FIG. 2 will be described.

Next, the recording signal in which the order of the segments is changed is divided into two channels by the recording processor 8 and recorded on the magnetic tape 1 by the magnetic heads 9a and 9b as shown in FIG.

In FIG. 4, taking the scan [1] as an example,
The data of segment 3 and segment 2 are recorded on one track by the magnetic head 9a in the order of segment 3 and then segment 2. Then, the magnetic head 9b records the data of the segment 1 and the data of the segment 4 on one track in the order of the data of the segment 1 and then the data of the segment 4.

In this way, the magnetic heads 9a and 9b similarly perform the scan [2] to the scan [5].
Recording is performed on the magnetic tape 1, and thereafter, the operations of scanning [1] to scanning [5] are repeated.

Next, the operation of the reproducing system will be described. The magnetic heads 10a and 10b are also the rotary drum 17 as in the conventional example.
The magnetic heads 10a and 10b also rotate when the rotary drum 17 rotates, and at the same time scans a track and supplies a reproduction signal to the reproduction processor 11.

In FIG. 4, taking the scan [1] as an example,
The magnetic head 10a allows the segment 3 and the segment 2
Data of segment 3 and then data of segment 2 are reproduced in this order. Further, the data of segment 1 and segment 4 is reproduced by the magnetic head 10b in the order of segment 1, then segment 4.

The reproduction processor 11 synthesizes the reproduced data into a digital signal for one field, and the de-shuffling circuit 21 restores the segments of each field to the original order as shown in FIG. Be done.

The demodulator 12 demodulates the digital signal into the original digital signal, and the error correction decoder 14
The error is detected and the error is corrected in, and the compression code is converted into the original digital video signal in the high efficiency decoder 14. The restored digital video signal is converted into an analog video signal in the D / A converter 15 and output from the output terminal 16.

Next, the digital VTR in this embodiment
The case of the double speed search will be described with reference to FIGS. 5, 6 and 7.

Here, as in the conventional example, the scanning loci of the magnetic heads 10a and 10b in the case of the speed search at the double speed of the digital VTR of the present invention are as shown in FIG.

In the case of the double speed speed search, the head scanning locus is generally as shown by the hatched portion in FIG. 18. However, when about half the track width is reproduced, the error correction processing or the like is performed. Since the data is almost completely restored, as a result, the shaded portion in FIG. 19 can be reproduced and reproduced by the magnetic heads 10a and 10b every two tracks.

An example of the relationship between the segment and the screen as shown in FIG. 20 is similar to the conventional example. The lower half of the segment corresponds to the left screen and the upper half of the segment corresponds to the right screen. is doing.

FIG. 5 shows a head scanning locus when a speed search at double speed is actually performed on the magnetic tape on which video information is recorded. In the case of normal reproduction, it is possible to obtain information for one field with 2.5 tracks.
This is the same for special reproduction.

Similar to the conventional example, in the case of the speed search of double speed, the video information for one field, that is, 2.5.
There are four patterns in which the video information for the tracks can be obtained. In FIG. 5, these are shown as patterns 1 to 4 for the hatching types. In the field number, the above four patterns are repeated in the period from field 0 to field 7. Hereafter, this 8 which is the basic unit
The speed search at double speed will be described using field 4 patterns.

First, taking pattern 1 as an example, the video information for 2.5 tracks includes the data of segment 3, segment 2, segment 1, segment 4 of field 0, and segment 5 and feed 2 of field 1.
Are the lower halves of segment 3 of each.

At this time, in pattern 1, the data of segment 3 of field 0 and the data of segment 3 of field 2 overlap in the lower half of the segment, that is, in the left screen of the segment as shown in FIG.

Therefore, the magnetic heads 10a and 1a are displayed on the screen.
In the reproduction processor 11, the data corresponding to the left screen of the segment 3 of the two fields which 0b reproduces later rewrites the data corresponding to the left screen of the segment 3 of the field 0 reproduced by the magnetic heads 10a and 10b. Is output with.

Similarly, in each of the patterns 2 to 4, the segment information in the scanning locus area surrounded by the hatched portion is detected as the screen information of one field.

In this way, pattern 1 to pattern 4
In the de-shuffling circuit 21, the digital signals of the fields up to are restored to the original order of the segments of each field as shown in FIG. 2 and output to the demodulator 12 to be demodulated to the original digital signal. To be done. Then, the error correction decoder 14 performs error detection and error correction, and the high-efficiency decoder 14 converts the compressed code into the original digital video signal. The restored digital video signal is converted into an analog video signal in the D / A converter 15. Then, the output terminal 16 outputs a double speed speed search screen.

Here, in FIG. 6, patterns 1 to 4 are shown.
Up to which position of the screen the information of which field is reproduced is shown. The numbers in the figure indicate the field numbers, and the crosses indicate that the corresponding segment could not be reproduced in one pattern.

As shown in FIG. 6, in the case of the speed search of double speed, four patterns of pattern 1 to pattern 4 are repeated, and therefore the portion marked with X becomes a fixed error pattern, which occurs on the screen. Compared with FIG. 22, that is, when the speed search at the double speed is performed on the magnetic tape recorded in the conventional recording format, the x mark is obviously reduced.

Therefore, the error pattern fixed on the reproduction screen is also reduced, and the image quality of the double speed search screen can be improved.

Example 2. Next, a second embodiment will be described. First, a digital VTR recording method according to an embodiment of the present invention and a case of a normal reproducing operation will be described.

FIG. 7 is a block diagram of a recording system and a reproducing system of the digital VTR of this embodiment. 1-17,
And 20 to 21 are the same as in Example 1 shown in FIG.
Corresponding parts are designated by the same reference numerals, and detailed description thereof will be omitted. In FIG. 7, 30 is the magnetic heads 10a and 10b.
Playback data memory for temporarily storing all the data output from the playback data memory, 31 a memory control circuit for controlling the operation of the playback data memory 30, and 32 an output from the de-shuffling circuit 21 and the playback data memory 30. 2 is a reproduction data synthesizing circuit for synthesizing the output of. Reference numeral 33 is a reconstructed block selecting means that refers to a series of operations of the memory control circuit 31, the reproduction data memory 30, and the reproduction data synthesizing circuit 32.

First, the operation of the recording system will be described with reference to FIG. Similar to the conventional example, the video signal input from the input terminal 2 is converted into a digital video signal in the A / D converter 3 and output to the high efficiency encoder 4.
The high-efficiency encoder 4 compresses information by utilizing the correlation of video information. The output of the high efficiency encoder 4 is input to the error correction encoder 5, and an error correction code for correcting a transmission error in recording and reproduction is added. The data to which the error correction code is added is converted into a recording signal suitable for the magnetic head and the magnetic tape in the modulator 6, and the recording signal for one field is converted into 5 by the segment divider 7 as in the conventional example.
It is divided into two segments.

The recording signal for one field divided into five segments is input to the shuffling circuit 20.

In the shuffling circuit 20, for example, as shown in FIG. 2, the order of the segments is changed within one field.

Next, the recording signal in which the order of the segments is changed is divided into two channels by the recording processor 8 and recorded on the magnetic tape 1 by the magnetic heads 9a and 9b as shown in FIG.

In FIG. 4, taking the scan [1] as an example,
The data of segment 3 and segment 2 are recorded on one track by the magnetic head 9a in the order of segment 3 and then segment 2. Then, the magnetic head 9b records the data of the segment 1 and the data of the segment 4 on one track in the order of the data of the segment 1 and then the data of the segment 4.

In this way, in the scans [2] to [5], the magnetic heads 9a and 9b similarly perform
Recording is performed on the magnetic tape 1, and thereafter, the operations of scanning [1] to scanning [5] are repeated.

Next, the operation of the reproducing system will be described. The magnetic heads 10a and 10b are also the rotary drum 17 as in the conventional example.
The magnetic heads 10a and 10b also rotate when the rotary drum 17 rotates, and at the same time scans a track and supplies a reproduction signal to the reproduction processor 11.

In FIG. 4, taking the scan [1] as an example,
The magnetic head 10a allows the segment 3 and the segment 2
Data of segment 3 and then data of segment 2 are reproduced in this order. Further, the data of segment 1 and segment 4 is reproduced by the magnetic head 10b in the order of segment 1, then segment 4.

The reproducing processor 11 synthesizes the reproduced data into a digital signal for one field, and the de-shuffling circuit 21 restores the segments of each field to the original order as shown in FIG. Be done.

The data output from the de-shuffling circuit 21 is input to the reproduction data synthesizing circuit 32. The reproduction data synthesizing circuit 32 outputs the data as it is during normal reproduction, and at the time of double speed search. , And the output data from the reproduction data memory 30.

The data output from the reproduction data synthesizing circuit 32 demodulates the digital signal into the original digital signal in the demodulator 12, the error is detected and the error is corrected in the error correction decoder 14, and high efficiency decoding is performed. In the converter 14, the compressed code is converted into the original digital video signal. The restored digital video signal is converted into an analog video signal in the D / A converter 15 and output from the output terminal 16.

Next, the case of the speed search at the double speed of the present digital VTR will be described with reference to FIGS. 7, 8 and 9. In the reproduction processor 11, as described in the first embodiment, the magnetic signals from the magnetic heads 10a and 10b are combined into a digital signal for one field, and the deshuffling circuit 21 is added.
At the same time, all the data reproduced from the magnetic heads 10a and 10b is output to the reproduction data memory 30.

The reproduced data memory 30 stores all reproduced data, as shown in FIG. 8 (a). Then, according to the control signal of the memory control circuit 31, necessary data is output to the reproduction data synthesizing circuit 32 at a necessary timing.

As shown in FIG. 8B, the data output from the de-shuffling circuit 21 is also output to the reproduction data synthesizing circuit 32 at the same time, and as shown in FIG. Is synthesized.

Taking pattern 1 as an example, FIG.
Although the field 2 is selected as the left screen of the segment 3 in (b), the left screen of the segment 3 of the field 0 previously reproduced is output on the screen in order to obtain a temporally natural image. It is obvious that is good.

Therefore, as shown in FIG. 8A, the data of the left screen of the segment 3 of the field 0, which has been previously reproduced and stored in the reproduction data memory 30, is output by the control signal from the memory control circuit 31. , In the reproduction data synthesizing circuit 32, the data on the left screen of the segment 3 of the field 2 is replaced.

Similarly, taking pattern 1 as an example, as shown in FIG. 8B, the data on the right screen of segment 5 is missing. Here, since the double speed search screen is repeated with one cycle from pattern 1 to pattern 4, the data on the right screen of segment 5 of pattern 4 one cycle before is inserted and output on the screen.

Therefore, the data on the right screen of the segment 5 of the pattern 4 which is the data stored in the reproduction data memory 30 shown in FIG. 8A, which is one cycle before, is output by the control signal from the memory control circuit 31, In the reproduction data synthesizing circuit 32, the segment 5 in the pattern 1 is inserted into the right screen portion.

In this way, as shown in FIG. 8C, the reproduced data synthesizing circuit 32 synthesizes the screens of the screen patterns 1 to 4.

In this way, pattern 1 to pattern 4
The 1-field digital signals up to are output to the demodulator 12, and the de-shuffling circuit 21 restores the segments of each field to the original order as shown in FIG. 2 to demodulate the original digital signals. To be done. Then, the error correction decoder 14 performs error detection and error correction, and the high-efficiency decoder 14 converts the compressed code into the original digital video signal. The restored digital video signal is converted into an analog video signal in the D / A converter 15. Then, the output terminal 16 outputs a double speed speed search screen.

Further, FIG. 9 shows an example of setting the reference field in each of the four patterns and expressing the difference between the fields of the reproduced segment with respect to the reference field in terms of the number of fields in the case of the double speed speed search. It is possible to judge whether a natural screen is being reproduced.

Compared with FIG. 23 in the case of the conventional example, there is no portion marked with X, that is, a portion which is not reproduced, and when the reproduced screen as a whole for each of pattern 1 to pattern 4 is taken, the time intervals are substantially equal. Moreover, it is possible to reproduce the data within each screen so that the temporal variation (field difference) between the segments is minimized. That is, a more natural speed search image is constructed.
It becomes possible to reproduce.

Example 3. Separation / arrangement of the segments will be described below based on still another embodiment. In Example 2, the segments 1, 3 and 4 are relatively stable in time in FIG. 9, but the segments 2 and 5 are 0.
It can be understood that the stability is slightly inferior with respect to the continuity of the reproduced image because there is a part →→→ 2 → + 1.

Therefore, it is expected that the portions arranged in the segments 2 and 5 will be slightly harder to see than the other portions during the double speed search. Therefore, by selectively arranging the image positions to be arranged in the segments 2 and 5 so as not to be noticeable at the time of reproduction, it is possible to further improve the quality of the speed search screen at double speed. An example of actual placement based on this idea will be described.

As shown in FIG. 13, for example, the video signal of one field is divided into five segments, and shuffling and de-shuffling are performed as shown in FIG.
With respect to the continuity of the reproduced image, by further arranging the segment 2 and the segment 5, which are worse than others, at the edge portion of the screen which is visually inconspicuous, further improvement of the 2 × speed search screen is performed. You can

In the above description of the embodiment, the double-speed speed search has been described as an example of the special reproduction speed, but it is not limited to the double speed and the same effect can be obtained at any speed. Is obvious.

[0101]

As described above, according to the present invention, since the screen area of one field can be reproduced to the maximum during the special reproduction, the reproduction error of the special reproduction screen can be minimized. Become.

Further, according to the present invention, the screen area of one field can be reproduced to the maximum during the special reproduction, and the non-reproduced portion in the image output unit screen and the temporally unnatural portion are excluded. By interpolating in the field of, it is possible to obtain a natural and excellent special reproduction screen.

Furthermore, according to the present invention, the screen area of one field can be reproduced to the maximum extent during special reproduction, and a portion which has not been reproduced and a portion which is unnatural in time in the image output unit screen can be reproduced. By interpolating in the field of 1 and arranging a temporally unnatural portion on the screen at a position that is visually unnoticeable, a natural and extremely good special reproduction screen can be obtained.

[Brief description of drawings]

FIG. 1 is a block diagram of a recording / reproducing system of a digital video signal recording / reproducing apparatus according to a first embodiment of the present invention.

FIG. 2 is a conceptual diagram of shuffling and de-shuffling according to Embodiments 1 and 2 of the present invention.

FIG. 3 is a recording format on a magnetic tape according to the first and second embodiments of the present invention.

FIG. 4 is a diagram showing a head scanning locus during recording and reproduction according to the first and second embodiments of the present invention.

FIG. 5 is a diagram showing a head scanning locus during a speed search at a double speed according to the first and second embodiments of the present invention.

FIG. 6 is a diagram showing a state of a reproduction screen at a speed search of 2 × speed according to the first embodiment of the present invention.

FIG. 7 is a block configuration diagram of a recording and reproducing system of a digital video signal recording / reproducing apparatus according to a second embodiment of the present invention.

FIG. 8 is a diagram for explaining a procedure of synthesizing reproduction data according to the second embodiment of the present invention.

FIG. 9 is a diagram showing whether a temporally natural screen is reproduced at the time of a double speed search according to the second embodiment of the present invention.

FIG. 10 is a recording format on a magnetic tape for explaining the first embodiment of the present invention.

FIG. 11 is a diagram for explaining an example of a method of determining a shuffling pattern of the present invention.

FIG. 12 is a diagram for explaining an example of a method of determining a shuffling pattern of the present invention.

FIG. 13 is a conceptual diagram of a recording method for describing a third embodiment of the present invention, in which a recording signal of one field is divided into five segments and recorded on a magnetic tape.

FIG. 14 is a conceptual diagram of shuffling and de shuffling for explaining a third embodiment of the present invention.

FIG. 15 is a conceptual diagram of a recording method in which a video signal of one field is divided into five segments and recorded on a magnetic tape.

FIG. 16 is a diagram showing a head scanning locus during recording and reproduction in a conventional digital video signal recording / reproducing apparatus.

FIG. 17 is a block configuration diagram of a recording system and a reproducing system of a conventional digital video signal recording / reproducing apparatus.

FIG. 18 is a diagram showing an actual scanning locus of the magnetic head of the digital video signal recording / reproducing apparatus.

FIG. 19 is a simplified diagram of a scanning locus of a magnetic head of a digital video signal recording / reproducing apparatus.

FIG. 20 is a diagram showing an example of a relationship between a segment and a screen.

FIG. 21 shows a conventional digital video signal recording / reproducing device 2
It is a figure showing a head scanning locus at the time of speed search of double speed.

FIG. 22 shows a conventional digital video signal recording / reproducing apparatus 2
It is the figure which showed the mode of the reproduction screen at the time of speed search of double speed.

FIG. 23 shows a conventional digital video signal recording / reproducing apparatus 2
FIG. 7 is a diagram showing whether or not a screen that is natural in terms of time is being reproduced at the time of double speed search.

[Explanation of symbols]

 1 Magnetic Tape 2 Input Terminal 3 A / D Converter 4 High Efficiency Encoder 5 Error Correction Encoder 6 Modulator 7 Segment Divider 8 Recording Processor 9 Magnetic Head 10 Magnetic Head 11 Reproduction Processor 12 Demodulator 13 Error Correction Decoder 14 High Efficiency Decompressor 15 D / A converter 16 Output terminal 17 Rotating drum 20 Shuffling circuit 21 De-shuffling circuit 30 Reproduction data memory 31 Memory control circuit 32 Reproduction data synthesizing circuit 33 Reconstruction block selecting means

Claims (6)

[Claims] 1. A recording block order changing method for recording a digital video signal on a magnetic tape by dividing a video signal of one field or one frame into a plurality of blocks, and corresponds to a switching operation cycle. With respect to the fields, the recording part of each field having a predetermined equal area on the tape pattern is divided into areas equally divided by the number of blocks, and the first field of the replacement operation cycle (hereinafter referred to as the start field). ), The correspondence between the blocks and the above areas is appropriately determined, and the reconstructed area of the start field during special reproduction is determined from the head scanning locus during special reproduction at a predetermined constant speed, and the obtained special reproduction is obtained. Of the areas, the area whose block allocation is undecided is restored during special playback of the start field. Select the block that is different from the block by erasing from the allocation block candidate (erase method), and then, in all combinations of the replacement operation cycle and special playback head scan trajectory pattern, block allocation in each field that is replayed during special playback A method for recording / reproducing digital video signals, characterized in that the digital video signal blocks are exchanged in the order determined by sequentially selecting the undetermined areas by the erasing method. 2. In the recording format determined by the method according to claim 1, one field or one frame at the time of special reproduction is set in all combinations of the block replacement operation cycle and the head scanning locus pattern at the time of special reproduction. Reconstruction data of each block when the image is reproduced, by selecting the reference field determined from the special playback speed and all the data obtained up to the time of image reconstruction, whichever has the smallest absolute value of the field difference. A method for recording / reproducing a digital video signal, characterized in that the special reproduction block selection / reconstruction order is determined so that the special reproduction operation is performed according to the same order. 3. The special reproduction method for reproducing images in the image reproduction order according to claim 2, wherein in all combinations of a block replacement operation period and a head scanning locus pattern during special reproduction, a reference field of individual blocks is used. And the sum of the absolute values of the field numbers to which the reconstructed data belongs, the data in the central part of the field or frame position is assigned to the smaller block among all blocks, and the data in the peripheral part is assigned to the larger block. And a method for recording and reproducing a digital video signal. 4. A digital video signal recording / reproducing apparatus for recording / reproducing a video signal of 1 field or 1 frame into a reciprocal number of blocks and using a plurality of magnetic heads for a plurality of tracks, at the time of recording 1 field. Alternatively, a block dividing means for dividing a recorded video signal of one frame into a plurality of blocks, and a reproduction on a field or a frame corresponding to a divided block reproduced when special reproduction is performed at a specific speed different from that at the time of recording A block recording order changing means for changing the block recording order in the order determined by the method according to claim 1 so as to maximize the area, and the blocks reproduced during normal reproduction and special reproduction for one field. And a reproduction signal synthesizing means for synthesizing the reproduction video signal of A digital video signal recording / reproducing apparatus comprising block reproduction order changing means for changing the raw order to the original order. 5. A reconstructed block selecting means for selecting a reconstructed block in the order determined by the method according to claim 2 during special reproduction is provided. A digital video signal recording / reproducing apparatus according to the item. 6. The method according to claim 4, further comprising block classification means for allocating the data on the screen determined by the method according to claim 3 to the block during special reproduction. The digital video recording / reproducing apparatus according to item 5.