JP3038799B2 - Video signal dubbing prevention device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video signal dubbing prevention apparatus for inhibiting illegal dubbing of a video signal in, for example, a VTR.

[Summary of the Invention]

The present invention relates to an apparatus for preventing dubbing of a video signal, in which a signal corresponding to an arbitrary integral conversion value of an effective screen is inserted into a video signal, and a signal corresponding to an arbitrary integral conversion value of the effective screen and the inserted signal are included. Is compared to determine whether dubbing is possible or not, illegal dubbing can be favorably prevented, and the formation of a release device for this prevention device is extremely difficult.

[Conventional technology]

For example, dubbing a commercially available soft tape in a VTR is not only legally illegal, but also infringes the rights of authors and the like, and impedes the sound spread of VTRs and soft tapes.

Conventionally, for such illegal dubbing of a soft tape, for example, a plurality of pseudo horizontal sync pulses are inserted within a vertical blanking period, and a signal of a white peak level is provided at the trailing edge of the pseudo horizontal sync pulse. Therefore, the AGC of the VTR on the dubbing side is caused to malfunction. Alternatively, the width of the vertical synchronization signal is narrowed so that vertical synchronization of the dubbing-side VTR is not performed.

[Problems to be solved by the invention]

However, in any of these, the processing performed on the video signal is fixed, so that it is easy to change the signal, and a release device that changes a non-dubbable video signal into a dubbable one can be formed at low cost. Met.

The present application has been made in view of such a point, and it is intended to prevent dubbing satisfactorily and to make it extremely difficult to form a release device.

[Means for solving the problem]

A first means according to the present invention comprises: an A / D converter (2) for digitizing an input video signal (input terminal (1));
Multipliers (31a) to (3a) to which the output of the / D converter is supplied
1p), an address supply means (timing decoder (32)) for supplying horizontal and vertical address signals of an effective screen of the input video signal, and conversion into the plurality of multipliers according to the address from the address supply means. (ROM (33)) for supplying coefficients for the plurality of multipliers, and a plurality of integrating means (adders (34a)-
(34p) and registers (35a) to (35p)) and a D / A converter (5) for converting the outputs of the plurality of integrating means into analog signals.
And an insertion unit (switch (6)) for inserting an output of the D / A converter into a predetermined position of the input video signal.

The second means is an A / D converter (2) for digitizing an input video signal (input terminal (1)), and a plurality of multipliers (31a) to which the output of the A / D converter is supplied. (31p) and address supply means (timing decoder (3p) for supplying horizontal and vertical address signals of the effective screen of the input video signal.
2)), a memory (ROM (33)) for supplying a coefficient for conversion to the plurality of multipliers according to the address from the address supply means, and a plurality of memories for integrating outputs of the plurality of multipliers, respectively. (Adders (34a) to (34p) and registers (35a) to (35p)), and outputs the outputs of the plurality of integrators and the signal inserted at a predetermined position of the input video signal to the A / D Digitized by the converter (A / D converter (1
2)) Comparison means (subtractor (51) to
Flip-flop (54)), and dubbing is disabled when the two signals do not match (terminal (17)).
An apparatus for preventing dubbing of a video signal as described above.

[Action]

According to this, the signals sequentially obtained by the calculating means are inserted into predetermined positions of the video signal, so that it is possible to easily determine whether dubbing is possible by comparing this signal with the signal obtained by the calculating means. In addition, by including an arbitrary integral conversion of the effective screen of the video signal in the arithmetic means, it is extremely difficult to form this signal by other means, and it is extremely difficult to form the release device without permission. can do.

〔Example〕

FIG. 1 shows an example of an apparatus for generating a signal for permitting dubbing and inserting it into a predetermined position of a video signal.
In this figure, an input video signal supplied to an input terminal (1) is digitized by an A / D converter (2) and, for example,
It is supplied to multipliers (31a) to (31p) constituting arithmetic means (3) for calculating six kinds of two-dimensional Hadamard transform values.

At the same time, the video signal supplied to the input terminal (1) is
The signals are supplied to the PLL (4) to form horizontal / vertical synchronization signals and clock signals, and these signals are supplied to the timing decoder (32). Further, from the timing decoder (32), address signals indicating the horizontal and vertical positions of the effective screen of the video signal are read-only memory (ROM) (33).
−1, 0, +1 for performing a two-dimensional Hadamard transform operation for each of the multipliers (31a) to (31p) according to the horizontal and vertical addresses from the ROM (33). Show 2
A bit (32 bits total) value is formed. These values are supplied to the corresponding multipliers (31a) to (31p).

Further, output signals of these multipliers (31a) to (31p) are supplied to registers (R) (35a) to (35p) through adders (34a) to (34p), respectively, and these registers (35a) to (35p) 35p) is the adder (34a)
To (34p) and integration is performed. In the drawing,
Since the circuits of the multipliers (31a) to (31p), the adders (34a) to (34p), and the registers (35a) to (35p) are repetitive, some of them are omitted.

Then, integrated values from these registers (35a) to (35p) are supplied to a shift register (36), and the shift register (36) receives a timing corresponding to a predetermined position of a video signal by a signal from a timing decoder (32). Are sequentially shifted. Immediately before this shift, the registers (35a) to (35p) receive signals from the timing decoder (32).
Is loaded into the shift register (36), and immediately after this shift, the contents of the registers (35a) to (35p) are cleared.

As a result, at the timing corresponding to the predetermined position of the video signal, conversion values (integrated values) obtained by two-dimensional Hadamard conversion of the effective screen of the video signal are sequentially shifted and extracted from the shift register (36). The converted value is converted into an analog signal by the D / A converter (5) and supplied to one fixed contact A of the switch (6). The video signal supplied to the input terminal (1) is supplied to the other fixed contact B. Further, the switch (6) is switched by a signal from the timing decoder (32) to form a video signal in which a signal of a conversion value converted into an analog signal by the D / A converter (5) is inserted at a predetermined position, It is taken out to the output terminal (7).

That is, FIG. 2 shows a procedure of signal generation. This example is applied to a so-called high-vision video signal.

In this figure, FIG. 7A schematically shows the effective screen of the previous field. For example, each of the multipliers (from the screen divided into 5 vertically and 8 horizontally) is selected. For each of 31a) to (31p), a value obtained by multiplying the signal of the pixel designated by the ROM (33) by -1 or +1 is formed as shown in the figure, and these values are integrated, and these integrated values are calculated. Are sequentially taken out and converted into analog signals to form signals as shown in FIG. Then, this signal is inserted, for example, at a predetermined position in the vertical blanking period of the video signal to form a video signal as shown in FIG.

For example, when dubbing is not allowed,
As shown in FIG. 3A, only the original video signal is recorded. On the other hand, when dubbing is permitted,
As shown in (1), a video signal with the above signal inserted is recorded at a predetermined position in the vertical blanking period. Alternatively, a video signal having the above-described signal inserted may be recorded at a predetermined position in the effective screen as shown in FIG.

FIG. 4 shows an example of an apparatus for determining whether dubbing is possible or not using the above-mentioned signals. In this figure, a video signal supplied to an input terminal (11) is digitized by an A / D converter (12), and a calculation for calculating, for example, 16 kinds of two-dimensional Hadamard conversion values having the same configuration as described above. The signals are supplied to multipliers (31a) to (31p) constituting the means (3). At the same time, the video signal supplied to the input terminal (11) is supplied to the PLL (14) to form horizontal and vertical synchronization signals and clock signals, and these signals are supplied to the timing decoder (32). The ROM (3
3) to shift register (36) are provided.

As a result, at the timing corresponding to the predetermined position of the video signal, conversion values (integrated values) obtained by two-dimensional Hadamard conversion of the effective screen of the video signal are sequentially shifted and extracted from the shift register (36). This converted value is supplied to a subtractor (51) for detecting coincidence. A / D converter (1
The digital value from 2) is supplied to a subtractor (51).
The subtraction output is supplied to digital comparators (52a) and (52b) and compared with a window corresponding to an arbitrary error range. The comparison output is supplied to a reset of a flip-flop (54) through a NAND circuit (53). You. Further, the flip-flop (54) is set by the signal from the timing decoder (32) immediately before the shift of the shift register (36), and the signal from the flip-flop (54) is supplied to the latch circuit (16). The latch circuit (16) is driven by the signal from the timing decoder (32) immediately after the shift of the shift register (36), and the signals sequentially detected by the subtracter (51) to the flip-flop (54) are latched. And output to the output terminal (18).

Therefore, in this circuit, when the signal inserted at a predetermined position of the video signal coincides with the conversion value obtained by sequentially performing the two-dimensional Hadamard conversion from the signal of the previous field, the subtractor (51) to the flip-flop (54) Are sequentially latched, and a control output enabling dubbing is output from an output terminal (18). On the other hand, when the signal inserted at the predetermined position of the video signal does not match the conversion value obtained by performing the two-dimensional Hadamard conversion on the signal of the previous field, the subtractor (51) to the flip-flop (54) No detection signal is obtained, and dubbing of the video signal at this time is prohibited.

Thus, according to the above-described apparatus, the signals sequentially obtained by the calculating means are inserted into predetermined positions of the video signal, so that this signal can be easily compared with the signal obtained by the calculating means for dubbing. In addition to being able to judge whether this is possible or not and including any integral conversion of the effective screen of the video signal in this arithmetic means, it becomes extremely difficult to form this signal by other means, and the unauthorized formation of the release device can be prevented. It can be extremely difficult.

That is, in the above device, the signal inserted into the video signal is changed for each field,
Therefore, it is extremely difficult to form this signal by means other than the above-mentioned calculating means (3). On the other hand, the arithmetic means (3) is composed of a complicated digital arithmetic processing circuit as described above. Such a circuit is, for example, in a consumer high-definition VTR, an integrated LSI with a digital circuit for processing video signals. This makes it easy to implement, and makes it extremely difficult to form an illegal release device due to misuse of this LSI or the like. In this case, the A / D converter (2) (1
2), PLL (4) (14), D / A converter (5), etc.
It can be omitted because it is shared with the video signal processing circuit.

In implementing the above-described apparatus, it is necessary to provide a circuit for forming the above-described dubbing-permitted signal in a video camera in which a signal is always dubbable. In a television tuner, a video enhancer, an AV selector, and the like, in which a signal is always allowed to be dubbed, it is necessary to have a characteristic in which a dubbing-enabled signal inserted in a signal transmitting side device such as a broadcasting station is transmitted. .

By the way, in the high-definition broadcasting described above, Muse
A method of transmitting only an effective screen of a video signal called VTR has been implemented, and a VTR based on this method has been proposed.

That is, FIG. 5 shows a VTR recording pattern in the Muse system. In this example, the 581st to 1120th horizontal scanning lines of the effective screen of the odd field are distributed over four tracks as shown in FIG. Is what you are doing. When this signal is reproduced, the signal in the vertical blanking period is restored as shown in FIG. B, and the original Hi-Vision signal is output.

In this case, for example, as shown in FIG. 6, if the 1120th horizontal scanning line in the effective screen is determined to be the area of the above-mentioned signal that allows dubbing, this signal can be a video signal band or a signal. Therefore, this signal can be transmitted with the conventional configuration, and by providing the recording side VTR with a device for determining whether or not the above dubbing is possible, good dubbing prevention can be performed. .

On the other hand, when it is not recognized that the effective screen is damaged, an arbitrary identification signal is provided in the postamble portion of the fourth track, for example, as shown in FIG. As shown in the figure, the signal in the vertical blanking period is restored, and the discrimination signal is discriminated to form a signal enabling dubbing. The signal is transferred to a predetermined position (for example, the ninth horizontal line) in the vertical blanking period. Scan line). As a result, the recording side VTR can determine whether or not the above-described dubbing is possible.

Further, FIG. 8 shows an example of an apparatus for generating a signal for enabling dubbing in that case and inserting the signal into a predetermined position of the video signal. In this figure, a signal obtained by restoring the above-described vertical blanking period is supplied to an input terminal (1), and an AND gate (9) is provided in a signal path from the above-mentioned timing decoder (7). The gate (9) is supplied with the discrimination output of the identification signal from the terminal (10). Others are the same as the above-mentioned apparatus. According to this, a signal that allows dubbing is inserted into the reproduction signal only when the identification signal is determined, and the above-described determination of whether or not dubbing can be performed can be performed by the VTR on the recording side.

FIG. 9 shows an example in which the above-described apparatus is integrated with an apparatus for determining whether dubbing is possible. In this figure, the digital value from the shift register (36) is further supplied to the subtractor (51), and the digital value from the A / D converter (2) is supplied to the subtractor (51).
The detection output from the subtractor (51) to the flip-flop (54) is supplied to the latch circuit (16). Further, the latch circuit (16) is driven by the signal from the timing decoder (32), and the signals detected by the subtractor (51) to the flip-flop (54) are sequentially latched and taken out to the output terminal (18). According to this, the device can be realized with an extremely simple configuration by sharing a circuit.

In implementing these devices, the so-called Muse
It is necessary to provide a similar circuit in a broadcast decoder device or the like. In that case, the decoder device of Muse broadcasting and the VT of Muse system
In R, video signal processing is performed digitally, so A / D
Circuits such as the converter (2), the PLL (4), and the D / A converter (5) can be omitted because they are shared with the video signal processing circuit.

〔The invention's effect〕

According to the present invention, the signals sequentially obtained by the calculating means are inserted into predetermined positions of the video signal, so that it is possible to easily determine whether dubbing is possible by comparing this signal with the signal obtained by the calculating means. In addition to being able to judge and including any integral conversion of the effective screen of the video signal in this calculating means, it is extremely difficult to form this signal by other means, and it is extremely difficult to form the release device without permission. You can now.

[Brief description of the drawings]

FIG. 1 is a block diagram of an example of an apparatus for generating a signal for enabling dubbing and inserting it into a predetermined position of a video signal by a video signal dubbing prevention apparatus according to the present invention, and FIG. FIG. 3 is a waveform diagram showing an example of a video signal, FIG. 4 is a configuration diagram of an example of a device for determining whether dubbing is possible or not, and FIGS. 8 and 9 are diagrams showing an example of a VTR recording pattern and a reproduction signal in the system, respectively. FIGS. FIG. 2 is a configuration diagram of an example of a device for inserting the device at a predetermined position. (1) (11) is an input terminal, (2) and (12) are A / D converters,
(3) arithmetic means, (4) (14) PLL, (5) D / A converter, (6) switch, (7) (17) output terminals,
(16) is a latch circuit, (31a) to (31p) are multipliers, (3
2) is a timing decoder, (33) is a read-only memory, (34a) to (34p) are adders, (35a) to (35p) are registers, (36) is a shift register, (51) is a subtractor,
(52a) and (52b) are digital comparators, (53) is a NAND circuit, and (54) is a flip-flop.

Claims (2)

(57) [Claims] An A / D converter for digitizing an input video signal, a plurality of multipliers to which an output of the A / D converter is supplied, and a horizontal and vertical address signal of an effective screen of the input video signal Address supply means for supplying a coefficient for conversion to the plurality of multipliers in accordance with the address from the address supply means, and a plurality of integration means for respectively integrating outputs of the plurality of multipliers A D / A converter that converts the outputs of the plurality of integration means into analog, and an insertion means that inserts the output of the D / A converter into a predetermined position of the input video signal. apparatus. 2. An A / D converter for digitizing an input video signal, a plurality of multipliers to which the output of the A / D converter is supplied, and a horizontal and vertical address signal of an effective screen of the input video signal. Address supply means for supplying a coefficient for conversion to the plurality of multipliers in accordance with the address from the address supply means, and a plurality of integration means for respectively integrating outputs of the plurality of multipliers And comparing means for comparing the output of the plurality of integrating means with a signal obtained by digitizing the signal inserted at a predetermined position of the input video signal by the A / D converter, wherein the two signals match. An apparatus for preventing dubbing of a video signal in which dubbing is disabled when not performed.