JP3185338B2 - Anti-dubbing apparatus and method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for recording and reproducing video signals, and more particularly to a video signal dubbing prevention apparatus and method for preventing illegal copying (copying or dubbing).

[0002]

2. Description of the Related Art Conventionally, various methods for preventing dubbing have been attempted for effectively preventing illegal dubbing in a video tape recording / reproducing apparatus or when providing a video signal. As one of the dubbing prevention methods, a copy protection method proposed by Macrovision Inc. (hereinafter referred to as a macrovision method) is known (for example,
See JP-A-63-107281. The outline of the macro vision system is described. As shown in FIG. 12, a signal having an excessive amplitude shown by a solid line exceeding a normal amplitude level shown by a broken line is applied during a blanking period of a video signal. A video tape recording / reproducing apparatus is provided with an automatic gain adjustment (control) circuit (AGC). Usually, a video signal which automatically adjusts a subsequent video signal based on the amplitude of a broken line level during recording is used. The automatic gain adjustment of the automatic gain adjustment circuit in the tape recording / reproducing apparatus is performed based on the excessive amplitude signal, and the automatic gain adjustment is intentionally disrupted.
As a result, the amplitude of the video signal following the excessive amplitude signal is recorded with its amplitude lower than the original level by automatic gain adjustment. When the dubbed video signal is reproduced, the display becomes dark and the image becomes difficult to see. Therefore, it is meaningless to reproduce and dub the image, which contributes to the prevention of dubbing.

[0003]

In the above-described macro vision system, an excessive amplitude signal is applied during a blanking period which does not affect the display of a normal video signal. For this reason, the macro vision method is based on the premise that the excessive amplitude signal is used without being removed in the video tape recording / reproducing apparatus and is applied. Therefore, a video tape recording / reproducing apparatus of a type in which only an input video signal is processed by a color difference line order method without removing and using an applied blanking period signal, for example, a video signal processing for high definition The device encounters a problem that the macrovision method cannot be applied because the excessive amplitude signal is not used.

A specific example of the above-described color difference line order video signal processing will be described in detail with reference to FIG. FIG. 13 (A)
Is a high-definition video signal, a luminance signal Y, a first luminance signal Y,
The color difference signal PB and the second color difference signal PR of FIG. 1 show the waveform forms of the video signal input to the video tape recording apparatus. FIG.
(B) shows the horizontal synchronization signal H in the video tape recording device.
-SYNC, other signals in the blanking period are removed, converted to a time-base compression / expansion (TCI) signal, and rearranged in a color difference line order to generate a signal form generated as an A channel signal Ach and a B channel signal Bch. Show. FIG. 13 (C)
Indicates that the horizontal difference signal H-SYNC,
The signal waveforms of the A and B channels to which a burst signal BURST, an index signal ID, and the like are added, FM-modulated, and recorded on a video tape via a magnetic head are shown. FIG.
The horizontal synchronizing signal H-SYNC, burst signal BURST, index signal ID, and the like shown in (C) are added in the video tape recording device. At the stage shown in FIG. 13A, even if an excessive amplitude signal by the macrovision method is applied during the blanking period,
Since the signal in the retrace period is removed at the stage of processing the signal (B), application of the excessive amplitude signal for the purpose of preventing dubbing becomes meaningless. An object of the present invention is to provide a dubbing prevention method which can be applied to a video signal recording / reproducing apparatus which performs the above-described color difference line order signal processing.

[0005]

According to a first aspect of the present invention, there is provided a video signal processing apparatus for processing an applied video signal in a color difference line order system. In an apparatus for providing a signal, both the horizontal and vertical portions of an overscan area around a region where a video signal is effectively displayed in a portion where a video signal is inserted are overlapped.
The first and second fields at the video signal insertion position corresponding to any or a plurality of the four corner portions only
Combinations of patterns that do not exist as normal video signals
An anti-dubbing device is provided, comprising a device for applying a code signal for prohibiting illegal dubbing.

According to a second aspect of the present invention, both the horizontal and vertical portions of an overscan area around a region where a video signal is effectively displayed in a portion where a video signal is inserted are displayed.
Any or more of the four overlapping corners only
Normal movies in the first and second fields of the position corresponding to
A dubbing prevention method is provided, wherein a code signal for preventing illegal dubbing of a combination of patterns that does not exist as an image signal is applied.

Further, according to a third aspect of the present invention, the horizontal and vertical portions of the overscan area around the area where the video signal is effectively displayed in the portion where the video signal is inserted are displayed.
Any or more of only the four corners overlapping the
Set of patterns that do not exist as normal video signals inserted in the first and second fields at positions corresponding to the minutes
Video signal recording apparatus comprising means for inhibiting the dubbing by detecting the code signal to prevent illegal dubbing combined is provided.

[0008]

In a video signal recording device that performs signal processing using the color difference line order method, for example, a video tape recording device,
Even if an excessive amplitude signal is applied during a blanking period (blanking period) by the macrovision method, the signal is removed and dubbing cannot be prevented. For example, as the format of the video signal for HDTV, the area where the video signal is displayed effectively,
An overscan area is defined around the area, and a spare area is defined outside the overscan area. The video signal is usually inserted at a position corresponding to the above-mentioned effective display area .
Any one of only the four corners that overlap vertically or
In the first and second fields at positions corresponding to multiple parts
Union of non-existent pattern as a normal video signal
Video signals were, for example, the first field is black putter
In the first and second fields, a video signal having a combination of white patterns can be inserted, and further, a spare area can be inserted.

Although the video signal inserted in the overscan area or the spare area is not displayed on the TV monitor, it is not a blanking signal, and is not removed in a video tape recording apparatus of the color difference line order system. Four corners that overlap both horizontally and vertically in the overscan area
The first part of the part corresponding to one or more parts of
And does not exist as a normal video signal in the second field.
If a video signal of a combination of different patterns is input as a code signal having a certain pattern capable of detecting illegal dubbing, it will not be displayed and will not affect normal reproduction. During dubbing, the video signal processing device detects a code signal of a certain pattern that does not exist as the normal video signal, and prohibits the dubbing.

[0010]

FIG. 1 is a block diagram showing a schematic configuration of a dubbing prevention apparatus according to the present invention. Hereinafter, as an embodiment of the present invention, an example will be described in which a video tape on which a video signal generated by the dubbing prevention apparatus of the present invention is recorded is applied to a high-definition video tape recording / reproducing apparatus. The anti-dubbing device includes a video signal generating device 1, an anti-dubbing signal adding device 3, a video tape 5 as an example of a video signal recording medium, and a video signal recording / reproducing device (or video signal processing device) 7 for high definition. .

FIG. 2 shows a video signal storage area for a high-definition signal defined by the BTA. FIG. 3 shows a display screen of a high-definition TV monitor. The video signal is stored in a range that covers the area 8B in FIG. 2, but the video signal located in the surrounding area 8B is reserved and is not displayed.
The shaded area 8A in FIG. 2 is the range in which the video signal is actually displayed. As illustrated in FIG. 3, the shaded area 8A includes the overscan area 10B and the effective display in the shaded area. Even if a video signal exists in a portion located in the overscan region 10B, which is composed of the region 10A, it is not actually displayed. For example, even for 1035 lines, actually, the video signal of about 97.5 to 95% of the number of lines is effectively displayed in the effective video display area 10A,
About several percent is defined as the overscan area 10B.
It is not displayed even if there is a video signal there.

An effective video signal having a time width of 25.86 μs is displayed in the horizontal (horizontal) time T2 of the image displayable area 8A in FIG. 2, and 1035 or 1080 horizontal lines are displayed in the vertical direction. is there. The spare area not to be displayed has 1125 lines in the vertical direction, and the time width T1 in the horizontal direction is 29.63 μs. Note that the horizontal time ta outside the image displayable area 8A in FIG.
tb is ta = 2.586 μs and tb = 1.18, respectively.
5 μs. The spare area 8B in FIG. 3 is the spare area 1 in FIG.
It corresponds to 0C.

The effective display area 10A in FIG. 3 is several percent smaller than the overscan area 10B. If the video signal is assumed to be overscan area 10B or spare area 1
Even if it is inserted at the position of 0C (8B), it is not displayed in the effective display area 10A, but since it is not a blanking period, the video signal is not removed by the video signal recording / reproducing device 7, and the video signal is not recorded. Sometimes it is subject to automatic gain adjustment. When a signal having a specific code pattern indicating dubbing prevention is applied to the portion located in the overscan area 10B or the spare area 10C by the anti-dubbing signal adding device 3, the video signal processing device 7 detects the code pattern signal and Dubbing can be prohibited. Since the code pattern signal for preventing dubbing applied to the overscan area 10B does not affect the display of the effective video display area 10A, the video tape 5 on which such a code pattern signal is recorded is reproduced by the video signal processing device 7. This does not affect the image displayed in the effective video display area 10A.

FIG. 4 shows a format of a high definition video signal. FIG. 5 is a partial view of a video tape format of a high definition video signal. In FIG. 4, counting from the vertical reference phase, 3H preamble PRE AM
Following BLE, as a position corresponding to the spare area 8B,
Lines 17-20 to 37 for the first field
-40, line 579-521 for second field
There is a spare video signal storage location on lines 599-602. The high-definition video signal displayed in the effective video display area 10A of the high-definition TV monitor screen 10 in FIG. 3 starts from 41 lines in the first field and 603 lines in the second field, counting from the vertical reference phase . A margin of about several percent is expected, and this margin is not displayed as the overscan area 10B. Symbol X in the preamble PRE AMBLE is an X signal, CW is a carrier signal, VL is a segment synchronization signal, and R is a portion where a ramp signal is set. Of the video signals,
Are displayed in the effective video display area 10A in the first field, 45 lines are displayed, and in the second field, 607 lines are displayed.

Referring to FIG. 6, the application position of the anti-dubbing signal DP in the overscan area will be described. In the present embodiment, of the overscan area 10B,
A dubbing prevention signal DP having a code pattern shown in FIG. 7 was applied to each of the corners A, B, C, and D. Originally, no video signal should exist at the corner of the overscan area 10B. Even if they exist, the combination of patterns as shown in FIG. 7 is not normally considered as a video signal in the natural world. Therefore, if a code signal having a pattern as shown in FIG. 7 is used as the dubbing prevention signal DP, it is easy to identify it as a dubbing prevention signal. Since the dubbing prevention signal DP is applied to the corner of the overscan area 10B, it does not affect the video signal displayed in the effective video display area 10A during reproduction.

FIG. 8 shows a video tape 5 to which the dubbing prevention signal DP is applied, reproduced by a reproducing apparatus 400.
When dubbing the reproduction signal, the dubbing prevention signal D
1 shows an apparatus configuration for detecting P. The detection device 500 has the code pattern signal shown in FIG. 7 at a position corresponding to the corners A, B, C, and D of the overscan area 10B in the video signal reproduced by the reproduction device 400. Detect whether or not to do. FIG. 9 shows a processing flowchart in the detection device 500. Step S01: The detection device 500 detects video signals of the corners A, B, C, and D of the overscan area among the video signals reproduced by the reproduction device 400. Step S02: The detection device 500 determines that the dubbing prevention signal DP has been detected when the signals at the corners A, B, C, and D of the overscan area indicate the pattern shown in FIG. Step S03:
If the detection device 500 determines that the dubbing prevention signal DP has been detected, the detection device 500 outputs a dubbing stop signal to the recording device 200. Upon inputting the stop signal, the recording device 200 stops recording the reproduced video signal.

The function of the detection device 500 shown in FIG. 8 may be incorporated in the recording device 200. FIG. 10 (A), (B)
Is a recording circuit 200 of the video signal recording / reproducing apparatus 7 incorporating a circuit for detecting such a dubbing prevention signal DP.
A and 200B show circuit examples. Recording device 200A
Are the input luminance signal Y, the first color difference signal P _B , the second
The color difference signals P _R dubbing preventing signal for detecting the low frequency signal pass filter block 20 of three systems for passing component, the dubbing preventing signal DP from the output signal of the low pass filter (which is called collectively as a video signal) It has a detection circuit section 41. The anti-dubbing signal detection circuit section 41 sequentially turns the corners A, B,
The signals existing there are extracted (detected) at the timings corresponding to C and D, and when the signal reaches the corner D of the overscan area, does the code pattern of the extracted signals match those shown in FIG. Determine whether or not. If it is determined that the signal is the dubbing prevention signal DP, the dubbing prevention signal detection circuit section 41 outputs a recording stop signal to the recording control circuit 43 to stop the subsequent dubbing. The anti-dubbing signal detection circuit section 41 includes an automatic gain adjustment circuit 2 described later.
It may be provided after 1. When the dubbing prevention signal DP is not detected, signal processing in the circuit described below is performed. After the anti-dubbing signal detection circuit 41,
Three automatic gain adjustment circuits (AG
C) Block 21, an A / D conversion circuit block 21A for converting a gain-controlled analog video signal into a digital video signal, a nonlinear emphasis signal processing circuit 22 for performing non-linear emphasis and vertical emphasis, and a non-linear emphasis signal processing circuit A time-division multiplexing (TDM) encoding signal processing circuit 23 is provided, which performs time-axis compression / expansion (TCI) signal processing on the output signal from the CPU 22 and performs shuffling processing for color difference line sequential processing. Automatic gain adjustment circuit block 2
1 is an A / D conversion circuit block 21 as indicated by a broken line.
It may be arranged after A.

Nonlinear emphasis signal processing circuit 2
2 the first color difference signal P _B and the second 2 for the color difference signals P _R strains of vertical filter circuit block 22A, 3
A vertical non-linear emphasis circuit block 22B of three systems and a horizontal non-linear emphasis circuit block 22C of three systems are provided.
A DM encoding signal processing circuit 23 is provided. The recording apparatus 200A further includes a D / A conversion circuit block 26, an emphasis circuit block 28, and an FM modulation circuit block 2 each having a two-system circuit configuration of A channel and B channel.
9, amplification circuit block 30, magnetic heads 31A and 31B
have. The signal addition circuit 24 and the synchronization signal
A burst signal generation circuit 25 is provided, and a synchronizing signal and a synchronizing signal
Synchronization signal SY generated from burst signal generation circuit 25
NC and burst signal BURST are applied.

In the configuration shown in FIG. 10B, the horizontal non-linear emphasis circuit block 22C is shifted to the subsequent stage of the TDM encode signal processing circuit 23.
By this arrangement change, the three horizontal non-linear emphasis circuits 22C shown in FIG. 10A become two horizontal non-linear emphasis circuits 22C '.

The operation of the recording device 200A or 200B shown in FIG. 10 will be described with reference to the video signal shown in FIG.
The luminance signal Y, the first color difference signal P _B , and the luminance signal Y shown in FIG.
When the second color difference signal P _R is applied to the low pass filter 20, from TDM encoding the signal processing circuit 23, FIG. 1
A color difference line-sequential signal of two A and B channels shown in FIG. The horizontal synchronization signal H-SYNC and the burst signal BURST output from the synchronization signal / burst signal generation circuit 25 are added to the output signal from the TDM encoding signal processing circuit 23. If necessary, an index signal ID (not shown) is also applied. Then, the D / A conversion circuit 26, the low-pass filter 27, the emphasis circuit 2
8, via the FM modulation circuit 29, the horizontal synchronizing signal H-
The video tape recording signal having the waveform shown in FIG. 11C to which the SYNC and the burst signal BURST are added is recorded on the video tape 5 from the magnetic heads 31A and 31B.

The dubbing prevention signal DP can be inserted at an arbitrary position in the overscan area 10B instead of at the corner of the overscan area. The code pattern shown in FIG. 7 is an example, and other patterns that do not exist in the natural world, for example, red, green, blue, white, or black at corners A, B, C, and D of the overscan area, respectively. Such a pattern can be used. Further, in the present invention, the code pattern signal can be inserted into a video signal storage position corresponding to a spare area outside the overscan area.

In practicing the present invention, various modifications can be made without being limited to the above-described embodiment. In carrying out the present invention, the above-described embodiments can be appropriately combined.

Although the above embodiment has been described with particular reference to an example utilizing the characteristics of a high-definition video signal, the anti-dubbing apparatus and method of the present invention are not limited to the prevention of dubbing of a high-definition video signal. Can be applied to available video signal forms.

[0024]

As described above, according to the present invention, it is difficult to cancel the anti-dubbing signal, and an effective anti-dubbing device is provided which records a video signal which is meaningless even if dubbing is prevented. The method can be provided. Also, since the anti-dubbing apparatus and method of the present invention do not affect the video signal itself to be displayed effectively, the anti-dubbing measures of the present invention do not affect the displayed image itself. .

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a dubbing prevention device of the present invention.

FIG. 2 is a plan view of a TV monitor screen for explaining an effective video signal portion of a Hi-Vision signal defined by BTA.

FIG. 3 is a plan view of a TV monitor screen for explaining an effective display portion of the TV monitor.

FIG. 4 is a diagram showing a format and a waveform of a high-definition video signal applied to the dubbing prevention apparatus of the present invention.

FIG. 5 is a diagram illustrating a format of a high-definition video signal.

FIG. 6 is a diagram showing a dubbing signal application position in the dubbing prevention apparatus of the present invention.

FIG. 7 is a diagram showing an example of a code pattern of a dubbing signal applied to the position shown in FIG. 6;

8 is a diagram illustrating a configuration of a video signal processing device that detects an anti-dubbing signal illustrated in FIG. 7 and prohibits illegal dubbing.

FIG. 9 is a flowchart showing a dubbing prevention signal detection process in the detection device shown in FIG. 8;

FIG. 10 is a circuit configuration diagram of a video signal recording device that records a video signal from a video tape by the dubbing prevention device of the present invention.

11 is a waveform diagram showing a recording operation process of a video signal to which a dubbing prevention signal according to an embodiment of the present invention is applied in the video signal recording device shown in FIG.

FIG. 12 is a diagram illustrating a waveform of a conventional anti-dubbing signal.

FIG. 13 is a diagram showing a recording process in a video signal processing device to which the dubbing prevention device of the present invention is applied.

[Explanation of symbols]

1. Video signal generating device 3. Dubbing prevention signal adding device 5. Video tape 7. Video signal processing device (video signal recording / reproducing device) 8.10 TV monitor screen for Hi-Vision 10A: effective video display area, 10B: overscan area, 20: low-pass filter block, 21: automatic gain adjustment circuit block, 21A: A / D conversion circuit block, 22: non-linear emphasis signal processing circuit , 22A-vertical filter circuit block, 22B-vertical non-linear emphasis circuit block, 22C-horizontal non-linear emphasis circuit block, 23-TDM encode signal processing circuit, 24-signal addition circuit, 25-・ Synchronization signal ・ Burst signal generation circuit, 26 ・ ・ D / A conversion circuit block , 27..Low-pass filter block, 28..Emphasis circuit block, 29..FM modulation circuit block, 31A, 31B..Magnetic head, 41..Dubbing prevention signal detection circuit section, 43..Recording control circuit, 200A , 200B ... recording device, 400 ... reproducing device, 500 ... detecting device.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H04N 5/91-5/956 H04N 9/79-9/898

Claims (3)

(57) [Claims] An apparatus for providing a video signal for use in a video signal processing apparatus for performing a signal processing on an applied video signal by a color difference line order method, wherein a video signal in a portion where a video signal is inserted is effectively displayed. Horizontal and vertical overscan areas around the area
Any one or more of the four corners that overlap directly
First and second files at the video signal insertion position corresponding to the portion
Pattern that does not exist as a normal video signal
An anti-dubbing device comprising a device for applying a code signal for inhibiting illegal dubbing of a combination . 2. An overscan area around a region where a video signal is effectively displayed in a portion where a video signal is inserted.
Only four corners that overlap both horizontally and vertically
Re or first and second off position corresponding to a plurality of portions
Pattern that does not exist in the field as a normal video signal
A method for preventing dubbing, comprising applying a code signal for preventing illegal dubbing of the combination of the above . 3. An overscan area around a region where a video signal is effectively displayed in a portion where a video signal is inserted.
Only four corners that overlap both horizontally and vertically
Re or first and second off position corresponding to a plurality of portions
It does not exist as a normal video signal inserted in the field.
A video signal recording device comprising means for detecting a code signal for preventing illegal dubbing of a combination of patterns and prohibiting dubbing.