JPH05210916A - Video signal recording and reproducing system - Google Patents

Abstract

PURPOSE:To improve the restoration capability of index information by constituting a track of video, audio, and index sectors and changing the recording position of the index sector at every interval of prescribed tracks. CONSTITUTION:Tracks 15 to 18 consist of video sectors V35 to V42 including video signal information, audio sectors A27 to A34 including audio signal information, and index sectors I19 to I26 including a time code and index information for program search and are recorded on a magnetic tape. The recording position of the sector A is changed between tracks 15 and 16 and tracks 17 and 18 and is recorded, and thus, index information is restored at a high speed even if a flaw 43 occurs on the magnetic tape, and restoration of index data is always prevented from being impossible, and the restoration reliability of index information is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording / reproducing system, and more particularly to recording / reproducing an index information in addition to a video signal and an audio signal, and improving the reliability in reproducing the index information. Regarding the scheme.

[0002]

2. Description of the Related Art The popularity of a video signal recording apparatus using a magnetic tape as a recording medium, in particular, a domestic VTR (hereinafter referred to as a VTR) has rapidly increased. Nowadays, compact and lightweight products with many functions are in practical use.

However, it is expected that demand for higher image quality will further increase in the future. The approach is
VTR for digital processing / digital recording (hereinafter DV
Is described as TR).

A conventional example of this DVTR will be described below with reference to the drawings. FIG. 3 is a block diagram showing a conventional example. In the figure, 44 is a video signal input terminal, 4
5 is a video signal output terminal, 46 is a video signal processor, 47 is an audio signal input terminal, 48 is an audio signal output terminal, 49 is an audio signal processor, 50 is a synthesizer / separator, 51 is a modulator / demodulator, and 52 is a magnetic The head 53 is a magnetic tape.

A video signal to be recorded is a video signal input terminal 4
4 to the video signal processor 46. In the video signal processor 46, A / D conversion of the video signal, high efficiency encoding,
Error correction coding, formatting, etc. are performed. On the other hand, the audio signal to be recorded is applied to the audio signal processor 49 via the audio signal input terminal 47. The audio signal processor 49 uses the audio signal A
A / D conversion, high efficiency coding, error correction coding, formatting, etc. are executed. The outputs of the video signal processor 46 and the audio signal processor 49 are combined by the combiner / separator 50 and then digitally modulated by the modulator / demodulator 51. After being digitally modulated, it is recorded on the magnetic tape 53 via the magnetic head 52 mounted on the rotating cylinder.

At the time of reproduction, the signal recorded on the magnetic tape 53 is taken out via the magnetic head 52 and supplied to the modulator / demodulator 51. The demodulator 51 demodulates digitally,
The synthesizer / separator 50 separates the data, and the information of the video signal is sent to the video signal processor 46 and the information of the audio signal is sent to the audio signal processor 49. The video signal processor 46 carries out a process reverse to that at the time of recording. That is, D / A conversion, inverse conversion of high efficiency encoding, error correction decoding, reformatting, etc. are executed. The audio signal processor 49 performs a process reverse to that at the time of recording. That is, D / A conversion, inverse conversion of high efficiency encoding, error correction decoding, reformatting, etc. are executed. The output of the video signal processor 46 is taken out as a reproduced video signal via the video signal output terminal 45. The output of the audio signal processor 49 is taken out as a reproduced audio signal via the audio signal output terminal 48.

A track recording pattern in the conventional example of FIG. 3 is shown in FIG. In FIG. 4, 54 is a magnetic tape, 55 is an already recorded track, 56 is a video sector, 57 is an audio sector, and 58 is a scratch on the magnetic tape 54. Will be explained later). Tracks 55 are formed and recorded on the magnetic tape 54 (53) by the magnetic head 52 shown in FIG.
The information created by the video signal processor 46 constitutes a video sector 56, and the information created by the audio signal processor 49 constitutes an audio sector 57. Generally, the audio sector 57 and the video sector 56 are separated from each other in terms of editing function.

[0008]

By the way, the VTR has an indispensable function not only for normal recording and reproduction but also for special reproduction, that is, slow reproduction and fast-forward reproduction. Further, a function of searching a desired place at high speed (hereinafter referred to as high speed search) is also very important. In addition, in the DVTR, it is possible to introduce a function of recording and reproducing not only video signals and audio signals but also other information by utilizing the characteristics of digital recording.

In high-speed search, the magnetic tape runs at a speed different from normal reproduction, and the magnetic head cannot trace the track correctly on the magnetic tape. This situation will be further described with (FIG. 4).

In FIG. 4, reference numeral 59 is a trace locus of the magnetic head 52 during high speed reproduction. In high-speed reproduction, since the running speed of the magnetic tape 54 (53) is different from that in the normal case, the magnetic head 52 cannot trace the original track 55, resulting in a trace locus such as 59. As the feeding speed of the magnetic tape 54 (53) becomes faster, the trace locus 59 crosses many tracks, and the signal reproduced from the magnetic head 52 becomes many short bursts.

By the way, the video sector 56 and the audio sector 57 are formed by a number of sync blocks having a predetermined length. Also, this sync block cannot be made extremely short in terms of efficiency. Therefore, when the feeding speed of the magnetic tape 54 (53) becomes faster, the length of the burst becomes closer to the sync block length or becomes shorter than the sync block length. This happens when,
Information in the video sector 56 and audio sector 57 cannot be reproduced at all.

Further, various damages may occur on the magnetic tape 54 (53), and a typical example thereof is a scratch 58 in the longitudinal direction of the magnetic tape. Therefore, the wound 58
When damage such as the above occurs on the magnetic tape 54 (53), an error occurs at a certain place on each track,
The same index data cannot always be restored.

The present invention solves such a problem, makes it possible to reproduce necessary information even in special reproduction, and makes it possible to restore index data with high reliability even if a longitudinal scratch on the magnetic tape occurs. Is.

[0014]

SUMMARY OF THE INVENTION To achieve this object, the present invention forms a magnetic track by forming at least a video sector containing video signal information, an audio sector containing audio signal information, and an index sector containing index information. By recording on a tape and changing the recording position on the track of the index sector for each predetermined track, the restoring ability of various index information is improved.

[0015]

[Operation] Reproduction at a higher speed than normal reproduction requires information reproduction such as "time code" and "head start". By including this information in the index sector and changing the recording position on the track of this index sector in a predetermined manner, it is of course possible to restore the index information at a high speed as described above, as well as the magnetic tape. Even if a scratch is generated in the longitudinal direction of 54 (53), the same index data is always prevented from being unrecoverable.

[0016]

EXAMPLES Examples will be described below together with examples of the present invention.

FIG. 1 is a block diagram showing an embodiment of the present invention. In the figure, 1 is a video signal input terminal, 2
Is a video signal output terminal, 3 is a video signal processor, 4 is an audio signal input terminal, 5 is an audio signal output terminal, 6 is an audio signal processor, 7 is an index input terminal, 8
Is an index output terminal, 9 is an index signal processor, 10 is a synthesizer / separator, 11 is a controller, 12 is a modulator / demodulator, 13 is a magnetic head, and 14 is a magnetic tape.

The video signal to be recorded is the video signal input terminal 1
Is applied to the video signal processor 3 via. The video signal processor 3 executes A / D conversion, high efficiency coding, error correction coding, formatting, etc. of the video signal. On the other hand, the audio signal to be recorded is applied to the audio signal processor 6 via the audio signal input terminal 4. The audio signal processor 6 executes A / D conversion, high efficiency coding, error correction coding, formatting, etc. of the audio signal. The index information applied through the index input terminal 7 is applied to the index signal processor 9. The index signal processor 9 performs error correction coding (or error detection coding), formatting, etc. on the index signal applied via the index signal input terminal 7. The output of the index signal processor 9, the output of the video signal processor 3 and the output of the audio signal processor 6 are combined by the combiner / separator 10 and then digitally modulated by the modulator / demodulator 12. After being digitally modulated, it is recorded on the magnetic tape 14 via the magnetic head 13 mounted on the rotary cylinder.

At the time of reproduction, the signal recorded on the magnetic tape 14 is taken out via the magnetic head 13 and supplied to the modulator / demodulator 12. The demodulator 12 demodulates digitally,
The synthesizer / separator 10 separates the data, and sends the video signal information to the video signal processor 3, the audio signal information to the audio signal processor 6, and the index signal to the index signal processor 9. The video signal processor 3 performs a process reverse to that at the time of recording. That is, D / A conversion, high efficiency coding inverse conversion, error correction decoding, error detection, reformatting, etc. are executed. The audio signal processor 6 also performs the reverse process of the recording. That is, D / A conversion, high efficiency coding inverse conversion, error correction decoding, error detection, reformatting, etc. are executed. Further, the index signal processor 9 also performs processing reverse to that at the time of recording, that is, error correction decoding (or error detection decoding) and reformatting.
As an output of the video signal processor 3, a reproduced video signal is taken out via the video signal output terminal 2. Further, as an output of the audio signal processor 6, an audio reproduction video signal is taken out via the audio signal output terminal 5. Further, the output of the index signal processor 9 is taken out as an index signal via the index signal output terminal 8.

In playback at a speed faster than normal playback (that is, in high-speed playback, etc.), it is important to restore information such as "time code", "head start", photographer identification and title, and index signal input terminal These index information are input and output via 7 and the index signal output terminal 8.
By doing this, information such as "time code" and "head start" can be played back at high speed.

By the way, the controller 11 controls the operation of the synthesizer / separator 10 during recording to control the position of the index sector on the track. Naturally, at the time of reproduction, the operation of the synthesizer / separator 10 is controlled to correctly separate the data from the modulator / demodulator 12.

The track recording pattern in the embodiment of the present invention shown in FIG. 1 is shown in FIG.

In FIG. 2, 35 to 42 are video sectors, 27 to 34 are audio sectors, and 19 to 26.
Is an index sector, 15 to 18 are tracks, 43
Is a scratch on the magnetic tape 14 in the longitudinal direction of the magnetic tape.

FIG. 2 shows the tracks 15 to 18 in a direction perpendicular to the magnetic tape for the sake of simplicity. Also, the case where the audio sectors 27 to 34 and the index sectors 19 to 26 have the same sector length is shown. Tracks 15 to 18 are formed and recorded on the magnetic tape 14 by the magnetic head 13 shown in FIG.
Now, focusing on the tracks 15 to 16, the information on the video signals created by the video signal processor 3 is related to the video sectors 35 to 38 (denoted by V in the drawing) and the audio created by the audio signal processor 6. The information constitutes audio sectors 27-30 (denoted A in the drawing). On the other hand, the information such as the above-mentioned "time code", "head start", identification of the photographer, and title constitutes index sectors 19 to 22 (indicated by I in the drawing) as index signals.

On the other hand, focusing on the tracks 17 to 18,
Information about the video signal created by the video signal processor 3 is stored in the video sectors 39 to 42 (denoted by V in the drawing).
Information about audio generated by the audio signal processor 6 is stored in the audio sectors 31 to 34 (see A in the drawing).
Is described). On the other hand, the "time code" mentioned above
Information such as "head start", photographer identification, and title is used as index signals in the index sectors 23 to 26.
(Indicated as I in the drawing). The controller 11 controls the synthesizer / separator 10 so that the tracks 15 to 18 become such a data stream.

The case where the scratch 43 occurs will be described below. The position on the track is different between the index sectors 19 to 22 on the tracks 15 to 16 and the index sectors 23 to 26 on the tracks 17 to 18, and the index sectors 19 to 22 on the tracks 15 to 16 are different.
22 are struck by wound 43, but index sectors 23-26 on tracks 17-18 are not struck by wound 43.
Therefore, even if the scratch 43 occurs in the longitudinal direction of the magnetic tape 14, the index data of the same type is always prevented from being unrecoverable. In addition, in the case of this embodiment, the positions on the tracks are different between the audio sectors 27 to 30 on the tracks 15 to 16 and the audio sectors 31 to 34 on the tracks 17 to 18, and the tracks 17 to
Audio Sectors 31-34 at No. 18 get hit by scratches 43, but Audio Sectors 27 at tracks 15-16
~ 30 is not fucked by the wound 43. Therefore, as for the audio information, even if the scratch 43 occurs in the longitudinal direction of the magnetic tape 14, the audio data at the same location is always prevented from being unrecoverable.

Although the present invention has been described with reference to the embodiments, the present invention is not limited to swapping the positions of the index sector and the audio sector as shown in FIG. The point is that the position of the index sector on the track is not always fixed at a fixed place,
The technical idea of the present invention is to change the position of each predetermined section.

Further, (FIG. 2) shows an embodiment in which the index sector and the audio sector have the same sector length, but the present invention exhibits the same effect even if these sector lengths are different.

Further, (FIG. 2) shows the case where the tracks are formed in the direction perpendicular to the magnetic tape, but this is for the sake of simplification of explanation, and of course, the helical scan method. However, the present invention is realized.

[0030]

As described above, according to the present invention, "time code" which is emphasized during reproduction at a speed higher than that of normal reproduction.
By including information such as "head start" and "index" in the index sector and changing the recording position on the track of this index sector in a predetermined manner, it is of course possible to restore the index information at a high speed as described above. However, even if scratches occur in the longitudinal direction of the magnetic tape, the same index data will not always be unable to be restored, and the restoration reliability of the index information can be improved.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a schematic diagram showing a recording pattern in an embodiment of the present invention.

FIG. 3 is a block diagram showing a conventional method.

FIG. 4 is a schematic diagram showing a recording pattern in the conventional method.

[Explanation of symbols]

 1 video signal input terminal 2 video signal output terminal 3 video signal processor 4 audio signal input terminal 5 audio signal output terminal 6 audio signal processor 7 index signal input terminal 8 index signal output terminal 9 index signal processor 10 combiner and separator Device 11 Controller 12 Modulator / demodulator 13 Magnetic head 14 Magnetic tape 15-18 Track 19-26 Index sector 27-34 Audio sector 35-42 Video sector 43 Scratch

Claims (3)

[Claims] 1. A track is formed by recording at least a video sector containing video signal information, an audio sector containing audio signal information, and an index sector containing index information on a magnetic tape, and recording the track on the magnetic tape. The video signal recording / reproducing system is characterized in that the recording position is changed every predetermined track. 2. The video signal recording / reproducing system according to claim 1, wherein the recording position of the index sector on the track and the recording position of the audio sector on the track are exchanged for each predetermined track. 3. The video signal recording / reproducing system according to claim 2, wherein the sector length of the index sector and the sector length of the audio sector are made equal to each other.