JPH07105942B2 - Video signal processor - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video signal processing device for changing the order of scanning lines of video signals in satellite communication and CATV.

2. Description of the Related Art Conventionally, in the video signal scanning line transition, each field effective screen is set to 240 lines, and a block of 60 lines in this range is set to 4 lines.
A block or a block of 30 lines is divided into 8 blocks, and scanning line transition is performed within each block. The number of lines in the block is switched in frame units, and the block is 60 blocks.
It was fixed to a block of lines or a block of 30 lines.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention In the scanning line transition by such a conventional video signal processing device, since the block performing the scanning line transition is fixed to a block of 60 lines or 30 lines in frame units,
When a video signal that has undergone a scan line transition is displayed on a monitor with a conventional video signal processing device, the boundaries of blocks can be easily confirmed on the screen, and a large clue that the viewer illegally decodes the content of the scan line transition. Becomes

Means for Solving the Problems To solve the above problems, a video signal processing device of the present invention is a video signal processing device having a first random number generating means, a second random number generating means, and a scanning line transfer means. The scanning line transition unit determines the number of scanning lines in a block, which is the size of the scanning line transition block for performing the scanning line transition, by the first random number generated by the first random number generation unit, and generates the second random number. The second random number generated by the means is used as an initial value to randomly replace the scanning lines in the number-of-scans block determined by the first random number. Action The present invention uses the above-described video signal processing device to display continuous screens. Scan line transition blocks of different sizes are mixed in
Moreover, since the configuration of the scanning line transition block can be changed even within the screen, it is difficult to detect the size and division of the block on the screen as compared with the conventional device in which the size of the scanning line transition block is fixed, A high degree of confidentiality can be realized against illegal decryption.

Embodiment A video signal processing device according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a video signal processing circuit diagram to which a video signal processing device according to an embodiment of the present invention is applied.
A / D converter, 3 is a memory, 4 is a control information input terminal to which control information for giving the processing content of the video signal is inputted, 5 is a random number generation circuit which sequentially shifts to generate random numbers, and 6 is a block latch pulse generation circuit , 7 is a latch, 8 is an intra-block address generation circuit, 9 is a D / A converter, and 10 is an output terminal of a video signal.

The video signal processing circuit used in the present embodiment performs the scanning line transition during the 240 lines of each field of the video signal. The video signal is input from the input terminal 1, converted into digital data by the A / D converter, and sequentially written in the memory 3. From the control information input terminal 4, the memory 3
The control information used as an initial value of how to read out the video signal written in and to perform the scan line transition process is input. The random number generation circuit 5 uses the control information input from the control information input terminal 4 as an initial value to sequentially generate random numbers M
The latch 7 is provided with a first random number and a second random number sequentially. The block rack pulse generation circuit 6 first gives a latch pulse to the latch 7 at the timing of determining the first block of the effective screen. Then, a first random number is provided as data for determining the number of lines in the first block, and an initial value for generating an address for randomly replacing lines in a block of a size determined by the first random number is given. The random number is latched by the latch 7. In-block address generation circuit 8
Are supplied with a first random number and a second random number, and the block latch pulse generation circuit 6 is supplied with a first random number that determines the timing for generating the next latch pulse. The first random number that determines the number of lines in a block is given by a random number sequence of 0 and 1, with 0 being 30 lines and 1 being 60 lines. It is assumed that 60 lines are designated in the first block. Now, the determination of the second block is performed by the block latch pulse generation circuit 6 according to the first random number which is the data of the number of lines of the first block given to the block latch pulse generation circuit 6.
Latch pulse 7 immediately before processing 60 lines.
Give to. With this latch pulse, the latch 7 latches the first random number and the second random number sequentially generated by the random number generation circuit 5 at the timing of the latch pulse, and is given to the intra-block address generation circuit 8 to generate the intra-block address. The generation circuit 8 generates an address that randomly replaces the lines of the second block. After that, by repeating this
60 lines and 30 lines in the period of 240 lines in each field
Blocks of lines are randomly specified. Here, when the first and second random numbers for processing the final block of each field are latched by the latch 7, if the number of remaining lines of the effective screen that can be processed as the final block is 30, the random number generation circuit 5 sequentially Even if a 60-line block is designated with the first random number shifted by 1, the data is forcibly converted into 30-line block data 0 by the latch 7 and given to the in-block address generation circuit 8. In this way, during the period of 240 lines of each field, the addresses for randomly switching the lines in the block of 60 lines and 30 lines are sequentially generated by the intra-block address generation circuit 8 and are sequentially supplied to the memory 3 by being supplied to the memory 3. The image data is read out after being randomly transferred by scanning lines for each block. Then, it is D / A converted and output from the output terminal 10 as an analog signal.

FIG. 2 is a block designation diagram showing a state in which blocks of 60 lines and 30 lines in each field are designated when a video signal is processed by the video signal processing device of the present invention. FIG. 2 shows an example of the nth field to the (n + 2) th field, with 60 lines in the field.
The block allocation of 30 lines is different in each field and is randomly specified.

As described above, the number of lines of a block and the data used for the processing of the block are sequentially obtained by the random number data from the random number generation circuit 5, so that the number of lines of the block is randomly specified. Boundaries can be obscured, and the processing contents of each block given by a random number also differ from block to block, so a high degree of confidentiality can be realized against illegal decryption.

As described above, the present invention is a video signal processing device having a first random number generating means, a second random number generating means, and a scanning line transition means, wherein the scanning line transition means is a first random number generation means. The number of scanning lines in the block, which is the size of the scanning line transition block for performing scanning line transition, is determined by the first random number generated by the means, and the second random number generated by the second random number generating means is set to the initial value. As the scanning lines in the scanning line block determined by the first random number are randomly exchanged, the scanning line transition blocks of different sizes are mixed in the continuous screen, and the scanning line transition block is also present between the screens. Since the configuration of can be changed, it is more difficult to check the block size and break on the screen compared to the conventional device with a fixed scan line transition block size, and high confidentiality against unauthorized decryption is achieved. Can be realized.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a video signal processing circuit in an embodiment to which a video signal processing device of the present invention is applied, and FIG. 2 is an embodiment to which a video signal processing device of the present invention is applied. 6 is a block designation diagram in FIG. 1 ... input terminal, 2 ... A / D converter, 3 ... memory, 4
...... Control information input terminal, 5 …… Random number generation circuit, 6 …… Block latch pulse generation circuit, 7 …… Latch, 8 …… In-block address generation circuit, 9 …… D / A converter, 10 ……
Output terminal.

Claims (1)

[Claims] 1. A video signal processing device having a first random number generating means, a second random number generating means, and a scanning line shifting means, wherein the scanning line shifting means is generated by the first random number generating means. The number of scanning lines within a block, which is the size of the scanning line transition block for performing the scanning line transition, is determined by the first random number generated, and the second random number generated by the second random number generating means is used as an initial value. A video signal processing device, wherein scanning lines in a scanning number block determined by a random number of 1 are randomly replaced.