JPH02224484A - Video signal recording device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a video signal recording device, and more specifically to a video signal recording device that digitally records a video signal on a recording medium.

[Prior Art] Conventional video signal recording devices that digitally record video signals on recording media include so-called digital VTRs, which perform interleaving processing on one screen worth of digital video data according to a fixed interleaving rule. After this, an error correction code is added, a synchronization code and an ID code are added to form a synchronization block, and the block is recorded on a magnetic tape using, for example, a rotating magnetic head.

FIG. 4 shows the block configuration and interleaving area of one screen in the conventional example, and FIG. 5 shows the interleaving rules. However, horizontal (horizontal) 16 pixels, vertical (vertical) 6
Pixels constitute the minimum unit for recording and reproduction (specifically, a synchronization block), and there are 120 such minimum units in the horizontal direction and 180 in the vertical direction.

[Problems to be Solved by the Invention] In the conventional example described above, when performing special playback by transporting a magnetic tape at an integral multiple of standard playback, for example, there may be a portion on the playback screen that is not played for a long time. Furthermore, in a digital VTR, there is a high possibility that the magnetic tape will be damaged in the longitudinal direction of the tape, and in this case, a corresponding portion of the screen will not be played back for a long time. Furthermore, in devices that perform multi-channel recording and playback, 1
When recording frame video signals over multiple tracks, if one of the multiple heads becomes damaged or otherwise unable to perform its function, the corresponding portion on the screen cannot be reproduced at all.

Furthermore, as shown in FIG. 4, since one interleaving sequence covers a wide range, a fixed pattern occurs in the reproduced image during high-speed reproduction, making it unsightly.

Therefore, it is an object of the present invention to provide a video signal recording device in which a part of the screen does not become unplayable for a long time.

[Means for Solving the Problems] A video signal recording device according to the present invention includes a dividing unit that divides one screen of digital video data into a predetermined number of divided blocks, and an interleave processing unit that performs interleaving processing for each divided block. and recording means for recording the video data interleaved by the interleave processing means on a recording medium, and is characterized in that the interleaving rule of the interleaving processing means is changed for each recording screen.

[Operation] With the above means, the target range of the interleaving process is narrowed, and adjacent video data on the screen are recorded close to the recording medium. Therefore, adjacent video data can be used in interpolation processing during playback, and image blur and deterioration of contours can be reduced. In addition, by changing the interleaving rules for each recording screen, even during special playback or when a specific head of a multi-head malfunctions,
The recording position of the recording medium corresponding to a fixed position on the screen is changed for each screen, so that a situation where a signal at a fixed position on the screen cannot be reproduced for a long time does not occur.

[Example] Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 shows a block diagram of an embodiment of the present invention. 1
0 is an analog video signal input terminal, 12 is an A/D converter, 4 is a random access memory that can store video data for one frame, and 16 is a part that divides the data in memory 14 for interleaving. frame division circuit, 1
8 is an interleaving processing circuit that performs interleaving processing to be described later on the data divided by the frame division circuit 16;
20 is an ECC that adds an error correction code ECC to the data read out from the memory 14 after completing the interleaving process.
Additional circuit, 22 is synchronization code 5ync and identification code I
Add D to form a synchronous block 5sync!
24 is a modulation circuit, 26 is a rotating magnetic head for recording, and 28 is a magnetic tape.

The analog video signal at the input terminal 10 is digitized by the A/D converter 12 and written into the memory 14. The frame division circuit 16 divides the data stored in the memory 14 under the control of the interleave processing circuit 18. FIG. 2 shows an example of the division. In this example, horizontal (horizontal) 16
Six vertical (longitudinal) pixels constitute a minimum unit for recording and reproduction (specifically, a synchronization block), and there are 120 such minimum units in the horizontal direction and 180 in the vertical direction. A group of 120 minimum units arranged in the horizontal direction will be called a line block. That is, there are 180 line blocks in one frame. As shown in FIG. 2, the frame dividing circuit 16 divides one frame into three vertically divided blocks #1, 1 and 2, each consisting of 60 line blocks. #2. Divide into #3.

The interleaving processing circuit 18 processes each divided block #1.
#2. #3 is individually subjected to interleaving processing under a constant interleaving rule.

In this way, the interleaved video data is read out from the memory 14, added with an error correction code in the ECC addition circuit 20, and added with a synchronization code 5ync and 5ync for synchronous block formation in the 5ync-ID addition circuit 22. An identification code ID is added, modulated by a modulation circuit 24, and magnetically recorded on a magnetic tape 28 by a magnetic head 26. Third
The figure shows the recording arrangement when ten line blocks are recorded on one track. In this example, 18 tracks are used to record one frame.

As can be seen from a comparison between FIG. 3 and FIG. 5 of the conventional example, in this embodiment, the image information within a track is information at very close screen positions within a divided block. In other words, because the interleaving area is narrowed, one track contains information that is close in distance in the vertical direction of one screen.

The interleaving processing circuit 18 performs interleaving processing as shown in FIG. 3 on the first frame.
For the next second frame, interleaving processing is performed in which the recording arrangement in FIG. 3 is shifted to the left as a whole, and the leftmost one is moved to the rightmost end. Specifically, the same line block of the second track of the first frame is recorded on the first track of the second frame, and the line block recorded on the first track of the first frame is recorded on the first track of the second frame. It is recorded on the 18th track. Similarly, the arrangement of each line block is sequentially shifted to the left for each frame, and the leftmost one is moved to the rightmost end. In the present invention, changes in interleaving rules between frames include:
Not only left shift but also right shift and other change rules can be adopted.

According to this embodiment, signals at adjacent positions on the screen are recorded on the same or adjacent tracks, so even if interpolation is required, sufficiently approximate signals can be used to form an interpolated signal. This prevents extreme blurring of image quality, deterioration of contours, and time lag. Furthermore, since the signal at a fixed position on the screen is recorded in a different track position on the magnetic tape for each frame, there will be no screen position that cannot be reproduced for a long period of time, even during high-speed reproduction, for example. In the case of multi-heads, even if a particular head is damaged, playback can be performed using another head in the next frame, so a certain position on the screen will not become continuously unplayable.

In this embodiment, one screen is divided into three divided blocks in the vertical direction, but this is just an example and does not preclude the adoption of other division methods. Further, as the recording medium, other than magnetic tape, recording media such as solid-state memory devices, magnetic disks, magneto-optical disks, etc. can be used. Recording to a recording medium and reproducing from it are technically equivalent to transmission and reception via a transmission path.

Therefore, in this specification, recording should be understood to include the meaning of transmission, and reproduction should be understood to include the meaning of receiving.

[Effects of the Invention] As can be easily understood from the above explanation, according to the present invention, fixed pattern errors do not occur;
Furthermore, it is possible to obtain a good reproduced image with less extreme image quality blurring and less deterioration of contour parts.

[Brief explanation of the drawing]

FIG. 1 is a configuration block diagram of an embodiment of the present invention, FIG. 2 is an explanatory diagram of division of the frame division circuit 16 of FIG. 1, FIG. 3 is an example of interleaved recording according to FIG. 1, and FIG. Conventional Block Configuration and Interleave Area FIG. 5 is an example of conventional interleave recording. 10: Input terminal 14: Memory 16: Frame division circuit 18: Interleave processing 20: ECC addition circuit 22: 5ync-FD addition circuit 24: Modulation circuit 26: Rotating magnetic head 28: Magnetic tape

Claims (1)

[Claims] A dividing unit that divides one screen of digital video data into a predetermined number of divided blocks, an interleave processing unit that performs interleaving processing for each divided block, and recording the interleaved video data of the interleave processing unit on a recording medium. 1. A video signal recording device, comprising: recording means, and changing the interleaving rule of the interleaving processing means for each recording screen.