JPH05300471A - Video signal reproducing device - Google Patents

Abstract

PURPOSE:To make it possible to make a variable-speed reproduced screen, which becomes an extremely unsightly screen as the screen becomes the one combined with the image data of the screens of other times at the time of a high speed reproduction in the case of a digital VTR and the location on the screen is dispersed every image block, an easily visible screen. CONSTITUTION:Reproduced signals which are different in the time when they are recorded by an image block unit in a first deshuffling memory 7 and a second deshuffling memory 8 are written at the time of a variable-speed reproduction. The image data which are the same in the time when they are recorded in all the image blocks is outputted in the output from an adder 12 by calculating a factor so that the time of the reproduced image may be the same in a factor calculation circuit 9 and multiplying the factor in a first multiplier 10 and a second multiplier 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video signal reproducing device for special reproduction.

[0002]

2. Description of the Related Art In recent years, many announcements have been made regarding a video tape recorder (hereinafter referred to as VTR) for digitally recording compressed data obtained by compressing a TV signal by high efficiency coding. As a method of this high-efficiency encoding, after orthogonal transform is performed on image block data such as adjacent 8 pixels × 8 lines, the orthogonal transform data of an image block group consisting of a predetermined number of image blocks is compressed to a fixed length. A method of performing such variable length coding processing is generally used. In addition, in order to improve the compression efficiency, a process of rearranging the order of the image blocks in one screen is performed before the variable length coding process is performed so that the positions of the image blocks in the image block group are apart from each other on the screen. Give. In such a VTR, the order of the image blocks corresponding to the data recorded on the tracks on the tape is different from the order of the positions on the screen.

FIG. 5 is a block diagram of a conventional VTR, FIG.
7 is a block diagram showing an image block group of a conventional VTR, FIG. 7A is a diagram showing screen data of a conventional VTR, FIG.
8B is a diagram showing tape recording data, FIG. 8 is a diagram showing a reproduction envelope signal at the time of high-speed reproduction, and FIG. 9 is a conventional VTR.
It is a figure which shows the content of the deshuffling memory at the time of high-speed reproduction of.

First, the recording operation of the conventional VTR will be described. In the recording section of the VTR shown in FIG. 5, a video signal is input to the input terminal 21. The video signal is A / D converter 22
At, it is converted into digital image data. The image data is subjected to a process of rearranging the data in the shuffling memory 23 in an order suitable for high efficiency encoding. That is, as shown in FIG. 6, image data is divided into image blocks 31 of, for example, 8 pixels × 8 lines, and an image block group 36 is composed of image blocks 31 to 35 whose positions in one field are separated from each other.

Data is output from the input shuffling memory 23 for each such image block group, and the encoding circuit 2
Added to 4. In the encoding circuit 24, processing such as orthogonal transformation is performed on each image block, fixed-length data is obtained for each image block group, converted into data suitable for recording by the recording data creation circuit 25, and then recorded on the tape. It Here, as shown in FIG. 7, the image blocks are sequentially recorded on the tape in units of image block groups.

Next, the variable speed reproduction operation of the conventional example will be described.
At the time of variable speed reproduction, the reproducing head 2 scans the tracks on the tape obliquely to output intermittent envelope signals as shown in FIG. Here, t1, t2 ...
t8 represents the time at the time of recording, and its interval is one field time. The reproduction data is added to the block reproduction circuit 4 via the reproduction amplifier 3. The block reproduction circuit 4 performs block detection and error detection / correction processing, and error-free block data is added to the reproduction / decompression circuit 5. The reproduction / reconstruction circuit 5 converts the data into image data for each image block and outputs the image data to the deshuffling memory 15. In the deshuffling memory 15, the image data is rearranged to create one screen of data, which is then D / A converted by the D / A converter 13 and output from the output terminal 14.

Here, in the deshuffling memory 15, FIG.
As shown in, the playback signal is written in several image blocks at different recording times, so the playback screen is a combination of image blocks of screens at different times, and the position in the field is also different. Have the same time for each image block group separated from each other. Also, the faster the playback speed, the greater the difference in time within one screen.

[0008]

As described above, in the VTR having the conventional structure, the variable speed reproduction screen is a combination of the image data of the screens at different times, and even in the image data of the screens at the same time, Since the positions on the screen are dispersed for each image block, there is a drawback in that the high-speed playback screen is very unsightly.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a video signal reproducing apparatus capable of making the variable speed reproduction screen easy to see.

[0010]

In order to solve the above problems, according to the present invention, a plurality of field memories for writing a signal reproduced from a magnetic tape and writing for the field memory are selected corresponding to reproduced signals. Means, a multiplier that multiplies each of the data read out from the field memory by a coefficient, and an adder that outputs the video signal by adding the output of the multiplier, corresponding to the recording time of the reproduction signal during variable speed reproduction. This is a configuration for determining the coefficient of the multiplier.

[0011]

According to the present invention, the coefficient of the multiplier is adjusted so that the time of each reproduced image block becomes the same for the data read simultaneously from a plurality of field memories corresponding to the recording time of the reproduced signal during variable speed reproduction. By determining, the image blocks of the output video signal have the same time, so that the high-speed playback screen can be easily viewed.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of a reproducing section of a video signal reproducing apparatus of the present invention, FIG. 2 is a view showing a reproduction envelope signal at the time of variable speed reproduction, and FIG. 3 is a reproduction deshuffling of the video signal reproducing apparatus of the present invention. FIG. 4 is a diagram showing the contents of the memory, and FIG. 4 is a diagram showing the coefficients of the multiplier of the video signal reproducing apparatus of this embodiment.

In FIG. 1, 1 is a magnetic tape, 2 is a reproducing head, 3 is a reproducing amplifier, 4 is a block reproducing circuit for performing block detection and error detection / correction processing on reproduced data, and 5 is data for each image block. And a reproduction / decompression circuit for converting into image data, 6 is a memory selection switch, 7 and 8 are first and second deshuffling memories capable of writing video data for at least 8 fields, and 9 is a coefficient operation circuit,
Reference numeral 10 is a first multiplier, 11 is a second multiplier, 12 is an adder, 13 is a D / A converter, and 14 is an output terminal.

The operation of this embodiment configured as described above will be described. First, at the time of variable speed reproduction in which the magnetic tape 1 is moved at a speed higher than the recording speed to reproduce a video signal, the reproducing head 2 scans the track on the magnetic tape 1 obliquely, as shown in FIG. Thus, an intermittent envelope signal is output. Where t1, t2
..T11 ... represents the time at the time of recording, and the interval is 1
It's field time. The reproduction data is added to the block reproduction circuit 4 via the reproduction amplifier 3. The block reproduction circuit 4 performs block detection and error detection / correction processing, and error-free block data is added to the reproduction / decompression circuit 5.

The reproduction / reconstruction circuit 5 converts the data into image data for each image block and outputs the image data to the memory selection switch 6. Further, the image data of t1 to t8 is written in the first deshuffling memory 7, and the image data of t9 to t16 is written in the second deshuffling memory 8.
A control signal for controlling the memory selection switch 6 is output to the memory selection switch 6. Based on the control signal, the memory selection switch 6 writes the first deshuffling memory 7 and the second deshuffling memory 8 every time the reproduction signal data is written for 8 fields, as shown in FIG. 2B. Select. As a result, the first deshuffling memory 7 and the second deshuffling memory 8 are stored in FIG.
As shown in (b), reproduction signals having different recording times are written in several image block units.

Here, in the coefficient calculation circuit 9, for example, the coefficients corresponding to the respective image blocks of the first deshuffling memory 7 and the second deshuffling memory 8 are shown so that the time of the reproduced image becomes t9. 4 (a) and (b) can be calculated. The first multiplier 10 and the second multiplier 11 multiply the image blocks by the coefficient shown in FIG. 4, so that the output from the adder 12 is the same image at the recording time t9 in all the image blocks. The data is output. That is, since the data of t1 is multiplied by the coefficient 0/8 by the first multiplier 10 and the data of t9 is multiplied by the coefficient 8/8 by the second multiplier 11, each multiplication result is added by the adder 12. The data of t9 is obtained by adding. Also, t2
Is multiplied by the coefficient ⅛ by the first multiplier 10, and the data of t10 is multiplied by the coefficient 7 / by the second multiplier 11.
Since 8 is multiplied, the addition data of each multiplication result is obtained by the adder 12 to obtain addition data of t2 · 1/8 + t10 · 8/7. This addition data is regarded as the data at time t9 by weighting the data at times t2 and t10. Similarly, t3 and t11, t4 and t12, t5 and t13 ...
· Weighted and added to.

The data added as described above is D
The signal is D / A converted by the / A converter 13 and output from the output terminal 14.

As described above, according to the present embodiment, when the high speed reproduction is performed, each reproduction is performed with respect to the data read at different times simultaneously from the two deshuffling memories 7 and 8 corresponding to the recording time of the reproduction signal. By determining the coefficients of the first and second multipliers 10 and 11 so that the time of the image block is the same, it is possible to make the time of the image block in the reproduction screen the same, and The screen can be made easy to see.

Here, in the present embodiment, all processing is performed in field units, but it is clear that the same effect can be obtained even when processing is performed in frame units. Further, in the present embodiment, the deshuffling process and the process for making the time of the variable speed reproduction image data the same are performed at the same time, but they may be configured separately. Further, every time the reproduction signal data is written for 8 fields, the first deshuffling memory 7
Although the writing of the second deshuffling memory 8 is selected, the present invention is not limited to this, and the first and second deshuffling memories are set to have a capacity capable of writing a plurality of fields, and writing is performed for a plurality of fields. First and second for each
Alternatively, the writing of the deshuffling memory may be selected.

[0021]

As is apparent from the above embodiments, the present invention makes it possible to set the same recording time in all image blocks in a reproduced image during variable speed reproduction, so that a video signal that is easy to see on a screen during high speed reproduction can be obtained. There is an effect that a reproducing device can be realized.

[Brief description of drawings]

FIG. 1 is a block diagram of a reproducing unit of a video signal reproducing apparatus according to an embodiment of the present invention.

FIG. 2A is a timing diagram of a reproduction envelope signal during high-speed reproduction, and FIG. 2B is a timing diagram of a control signal of a memory selection switch during high-speed reproduction.

FIG. 3A is a diagram showing the contents of the deshuffling memory during high-speed reproduction in the present embodiment. FIG. 3B is a diagram showing the contents of the deshuffling memory during high-speed reproduction in the present embodiment.

FIG. 4A is a diagram showing coefficients of a multiplier in one embodiment of the present invention; FIG. 4B is a diagram showing coefficients of a multiplier in one embodiment of the present invention;

FIG. 5 is a block diagram of a conventional VTR.

FIG. 6 is a block diagram showing an image block group of a conventional VTR.

7A is a diagram showing screen data of a conventional VTR, and FIG. 7B is a diagram showing recording data of a magnetic tape of the conventional VTR.

FIG. 8 is a diagram showing a reproduction envelope signal during high-speed reproduction of a conventional VTR.

FIG. 9 is a block diagram showing the contents of a deshuffling memory during high-speed playback of a conventional VTR.

[Explanation of symbols]

 6 Memory Selection Switch 7 First Deshuffling Memory 8 Second Deshuffling Memory 9 Coefficient Operation Circuit 10 First Multiplier 11 Second Multiplier 12 Adder

Claims (1)

[Claims] 1. A plurality of field memories for writing a signal reproduced from a recording medium, a unit for selecting writing in the field memory corresponding to a reproduced signal, and a multiplication for multiplying each of the read data of the field memory by a coefficient. And a multiplier for adding a calculation result of the multiplier and outputting a video signal, wherein the coefficient of the multiplier is switched according to the time when the reproduction signal is recorded during variable speed reproduction. Signal reproduction device.