JPH10210431A - Video signal transmission method, superimposed information extracting method, video signal output device, video signal receiver and video signal recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely provide additional information superimposed on a video signal by preventing the additional information superimposed on the video signal by spreading a spectrum from being diminished or deteriorated. SOLUTION: A pseudo-random noise PN code generating control part 15 generates a PN code reset timing signal RE to start generation of a PN code string for every one vertical section, forms a PN code generating clock signal PNCLK of one horizontal period or plural horizontal periods and supplies them to a spread spectrum SS copy prevention control signal generating part 16. The SS copy prevention control signal generating part 16 makes the vertical section one period and generates repetitively the PN code string, in which one tip is assigned to one horizontal section or plural horizontal/sections and applies spread spectrum processing to a copy prevention control signal S3 by using the PN code string, so as to be completed in the PN code string by one period to form an SS copy prevention control signal S5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to, for example, reproducing a video signal recorded on a recording medium, transmitting the reproduced signal together with information for preventing duplication, receiving the transmitted video signal, and transmitting the received video signal to another recording medium. As in the case where recording is restricted or prohibited, additional information is superimposed on the video signal and output, and this is received, the superimposed additional information is extracted, and duplication prevention control using the extracted additional information is performed. And a video signal recording medium.

[0002]

2. Description of the Related Art With the widespread use of VTRs (video tape recorders), many software programs that can be played back on VTRs have been provided. In recent years, digital VTRs and DVD (digital video disk) playback devices have become reality, and it has become possible to easily play back and view video and audio with good image quality and sound quality. ing.

[0003] On the other hand, however, there is a problem that such abundantly provided software may be copied indefinitely, and various countermeasures against copying have been conventionally taken.

For example, although this is not a method of directly prohibiting copying of an analog video signal, for example, a VTR as a recording device and an AGC of a monitor receiver for providing video are used.
There is a method of substantially preventing duplication by utilizing a difference in (auto gain control) method or a difference in APC (auto phase control) characteristics.

That is, for example, a VTR performs AGC using a pseudo-synchronous signal inserted into a video signal, and a monitor receiver employs an AGC method that does not use the pseudo-synchronous signal. In the former example, when recording an analog video signal on an original recording medium, a pseudo-synchronous signal having an extremely large level is inserted as a synchronizing signal for AGC, and recording is performed from a reproduction VTR. Video signal supplied to the VTR
As a synchronizing signal for C, a pseudo synchronizing signal whose level is extremely large is inserted.

APC in a VTR follows a color burst signal in a video signal with a short time constant, whereas an APC in a monitor receiver follows a color burst signal with a relatively long time constant. The latter method is a method of utilizing the difference. When an analog video signal is recorded on the original recording medium, the phase of the color burst signal of the video signal is partially inverted, and the phase is changed from the reproduction VTR to the recording VTR. It outputs a signal in which the phase of a color burst signal is partially inverted as a supplied video signal.

In the case described above, in a monitor receiver that receives an analog video signal from a reproduction VTR, the effect of partial inversion of the phase of a pseudo-synchronous signal or a color burst signal used for APC. The video is normally reproduced without receiving the video.

However, upon receiving the analog video signal from the reproduction VTR into which the pseudo-synchronous signal has been inserted as described above or under the phase inversion control of the color burst signal, this is recorded on a recording medium. In a VTR, gain control or phase control based on an input signal cannot be normally performed, and a video signal cannot be normally recorded. Therefore, even if the recorded video signal is reproduced, a normal viewable video can be prevented from being reproduced.

When an analog video signal is handled in this way, duplication is not prohibited, but a reproduced video that can be normally viewed is not obtained. This is a passive copy prevention control. It is.

On the other hand, when dealing with digitized information such as a video signal, a copy protection control signal comprising a copy protection code or a copy generation limit code is added to the video signal as digital data. By recording on a recording medium, direct duplication prevention control such as prohibition of duplication is performed.

FIG. 9 is a basic configuration diagram of a duplication apparatus for handling the digitized information. The digital information reproduced by the digital reproduction apparatus 110 is transmitted to the digital recording apparatus 120 through the digital transmission path 101. Those that can be sent and duplicated execute the duplication, and those that are not permitted are those that prohibit the duplication.

[0012] In addition to digital main information, copy prevention control information as additional information is recorded on the recording medium 111 loaded in the digital reproduction device 110. This copy prevention control information indicates, as control contents, copy prohibition, copy permission, generation restriction, and the like. The digital reproduction unit 112 reads information from the recording medium 111, obtains duplication prevention control information together with digital main information, and sends this to the digital recording device 120 via the digital transmission path 101.

The anti-duplication control signal detector 122 of the digital recording device 120 detects an anti-duplication control signal from information received through the digital transmission line 101, and determines the control content. The discrimination result is stored in the digital recording unit 1.
Send to 21.

The digital recording section 121 receives the result of the determination of the copy protection control signal from the copy protection control signal detection section 122,
When the recording of the digital information input through the digital transmission path 101 is permitted, the input digital signal is converted into digital information suitable for recording, and is written on the recording medium 123 to execute recording. on the other hand,
When the determination result of the copy protection control signal from the copy protection control signal detection unit 122 indicates that copying is prohibited, the digital recording unit 121 does not perform the recording processing of the input digital information.

Further, when the determination result of the copy protection control signal from the copy protection control signal detection section 122 indicates that only the first generation copy is permitted, the digital recording section 12
Numeral 1 converts the input digital signal into digital information suitable for recording, writes the digital signal on the recording medium 123, executes recording, and instructs the duplication prevention control signal as additional information to prohibit duplication (prohibition of next generation duplication). To be recorded on the recording medium 123. Therefore, the video signal cannot be duplicated using the duplicated recording medium 123.

As described above, the main information signal and the anti-duplication control signal as additional information are supplied as digital signals to the recording apparatus. Since the control signal is included, it is possible to reliably perform the copy prevention control such as the copy inhibition in the recording apparatus by using the copy prevention control signal.

[0017]

In the case where the digital reproducing apparatus shown in FIG. 9 is, for example, a digital VTR, the reproduced video signal and audio signal are monitored.
Only the video and audio signals that are the main information signals are D / A
An analog signal is converted through a conversion circuit 113 into an analog signal, and an analog output terminal 114 to which a monitor receiver is normally connected.
To be derived.

As described above, even in a digital information reproducing apparatus, an analog signal derived from the analog output terminal 114 does not include a duplication prevention control signal. Therefore, in the case of an analog connection in which an analog VTR or the like is connected to the analog output terminal 114, the information signal can be duplicated.

Therefore, it is conceivable to superimpose a duplication control signal on the D / A-converted video signal or audio signal. However, the D / A-converted video signal or audio signal can be copied without deterioration. It is difficult to add a prevention control signal and take it out of the recording apparatus and use it for copy prevention control.

Therefore, conventionally, in the case of analog connection, a passive copy protection method using the above-described difference between the AGC method of the VTR and the monitor receiver or the difference between the characteristics of the APC is used. There was no other way but to do.

However, in the case of the above-described copy prevention control method using the difference between the AGC method of the VTR and the monitor receiver or the difference of the APC characteristic, the AGC on the recording apparatus side is used.
In some cases, depending on the type of APC and the characteristics of the APC, the video signal is normally recorded, and the passive duplication prevention may not be possible. In addition, there is a possibility that a problem that a reproduced image of the monitor receiver is disturbed occurs.

As an effective duplication prevention control method which solves the above problems and is effective for both analog connection and digital connection without deteriorating reproduced video and audio, the present applicant has In addition, a method has been proposed in which the anti-duplication control signal is spectrum-spread and the spectrum-spread anti-duplication control signal is superimposed on the video signal in the state of an analog signal to digitally or analog record the video signal (Japanese Patent Application Hei 7-339959).

In this system, a code of a PN (Pseudorandom Noise) sequence (hereinafter, referred to as a PN code) used as a spreading code is generated at a sufficiently short cycle, and is multiplied with a duplication prevention control signal to thereby obtain a spectrum. The spread, narrow-band, high-level anti-duplication control signal is converted to a wide-band, low-level signal that does not affect video or audio signals. Then, the spectrum-spread anti-duplication control signal is superimposed on the analog video signal and recorded on the recording medium. In this case, the video signal to be recorded on the recording medium can be either analog or digital.

In this system, since the duplication control signal is spread spectrum and superimposed on the video signal as a wideband, low-level signal, a person trying to copy illegally can copy the superimposed duplication control signal. It is difficult to remove from the video signal.

However, it is possible to detect and use the superimposed anti-duplication control signal by performing inverse spectrum spreading. Therefore, the duplication control signal can be reliably provided to the recording device together with the video signal, and the recording device can detect the duplication control signal and reliably perform the duplication control according to the detected duplication control signal. It can be carried out.

However, as described above, in the case of the system in which the anti-duplication control signal is spread spectrum and superimposed on the video signal, the anti-duplication control signal which has been spread spectrum is removed by using the noise reduction system of the video signal. Or may be degraded or replaced.

For example, in the case of a noise elimination system that removes noise of a video signal by utilizing the correlation between fields and frames of a video signal, a difference is obtained between video signals between adjacent fields and between frames. The obtained difference is removed as noise.

In this case, the anti-duplication control signal that is spread spectrum and superimposed on the video signal is calculated as a difference, and may be removed as described above. Further, when the signal is removed, there is a possibility that the signal is replaced with another spectrum-spread anti-duplication control signal.

In the case where the above-described noise elimination system is used, not all of the anti-duplication control signals which are spread spectrum and superimposed on the video signal are partially transmitted. The copy prevention control signal may be degraded, for example, by being removed. In this case,
It becomes impossible to extract an accurate duplication prevention control signal superimposed on a video signal, and it becomes impossible to perform anti-duplication control according to the duplication prevention control signal.

Further, for example, when a so-called landscape wide TV image having an aspect ratio of 16: 9 is converted into a standard TV image having an aspect ratio of 4: 3, or vice versa, the horizontal direction is used. When the horizontal portion is deleted, the spread-spectrum duplication control signal superimposed on the decimated video signal disappears, or the spread-spectrum duplication prevention control signal is discontinuously interpolated by the interpolated data. In other words, the anti-duplication control signal may not be restored due to spectrum despreading.

When a VTR performs variable-speed playback such as slow-motion playback or double-speed playback, the video signal for one field is lost or duplicated. The anti-duplication control signal becomes discontinuous, and the anti-duplication control signal may not be restored due to spectrum despreading.

Also, when the so-called cut editing is performed and the video signal in the field unit is thinned out, similarly, in the video signal after the cut editing, the spread-spectrum duplication prevention control signal is discontinuous. And the anti-duplication control signal may not be restored due to spectrum despreading.

In view of the above, the present invention has been made to solve the above-described problem, and to provide the additional information which is spread spectrum and superimposed on the video signal to the receiver without fail, and to extract the complete additional information. It is an object of the present invention to provide a method, an apparatus and a video signal recording medium which enable it.

[0034]

In order to solve the above-mentioned problems, a video signal transmission method according to the first aspect of the present invention comprises:
A transmission method in which spectrum spread additional information is superimposed on a video signal and transmitted, wherein a period within one vertical section is defined as one cycle based on a synchronization signal, and a space which is a horizontal direction and a time axis direction of a screen unit. The additional information is repeatedly generated using the spreading code, and the additional information is spectrum-spread so as to be completed in the section within the one vertical section. It is characterized by being superimposed on a signal and transmitted.

According to a fourth aspect of the present invention, there is provided the superimposition information extracting method, wherein a period within one vertical section is defined as one cycle with respect to a synchronization signal, and a spatial direction which is a horizontal direction and a time axis direction in screen units. A superimposition information extracting method for extracting the additional information from a video signal on which additional information that has been spectrum-spread so as to be completed within one vertical interval by a spreading code that is repeatedly generated so as to be the same as above. In synchronization with a synchronization signal, a despreading code having a period within one vertical section as one cycle is repeatedly generated corresponding to the section in which the spectrum-spread additional information is superimposed, and The additional information superimposed on the video signal is repeatedly extracted by performing spectrum despreading using a spreading code.

According to the video signal transmission method of the present invention, the spread code is the same in the horizontal direction, and one chip of the spread spectrum signal is superimposed on each horizontal line. Therefore, even if horizontal thinning or interpolation is performed, the spectrum-spread additional information (spread-spectrum signal) is reliably transmitted.

The spread code is also the same in the spatial direction (hereinafter, simply referred to as the time axis direction) which is the time axis direction of the screen unit, and the same chip of the spread spectrum signal is also superimposed in the time axis direction. Will be done.

Accordingly, when a noise removal system utilizing the correlation between fields and frames of a video signal is used, even if a difference is obtained between fields and between frames, the spectrum superimposed on the video signal is obtained. Since the spread signal is not detected as a difference, it is not deleted or deteriorated. Even if variable speed reproduction or cut editing is performed, the spread spectrum signal is transmitted reliably in the same manner.

According to the superimposition information extracting method according to the fourth aspect of the present invention, while synchronizing with the synchronizing signal, the section in which the spectrum-spread additional information (spread spectrum signal) is superimposed, A spreading code for despreading is generated. By performing despread spectrum using the spread code for despreading, additional information is repeatedly extracted.

Therefore, as described above, the use of the noise elimination system utilizing the correlation of the video signal prevents the additional information spread in the spectrum from being removed or deteriorated. Further, even when interpolation and thinning of pixels in the horizontal direction by horizontal reduction and enlargement of the video signal are performed, the additional information superimposed on the video signal can be reliably extracted.

[0041]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a video signal transmission method, a superimposition information extraction method, a video signal output device, a video signal receiving device, and a video signal recording medium according to the present invention will be described below with reference to the drawings.

The video signal output device described below uses a DV
D (Digital Video Disc) recording / reproducing device (DVD
The following description will be made assuming that the present invention is applied to an apparatus.
Also, for simplicity of description, description of the audio signal system is omitted.

FIG. 1 is a diagram for explaining a video signal output device (hereinafter, simply referred to as an output device) 10 used in the video signal duplication control system of this embodiment. That is, the output device 10 corresponds to the reproduction system of the DVD device in the first embodiment.

In FIG. 1, a recording medium 100 stores a digitized video signal and an audio signal, and a duplication prevention control signal as additional information. In this example, the recording medium 100 is a DVD. The anti-duplication control signal is the innermost and outermost TOC (Table Of Contents) of the disc.
Alternatively, the data can be recorded in a track area called a file or a directory, or can be inserted and recorded in a track where video data and audio data are recorded, with a separate recording area. The example described below is an example of the latter case, in which, when video data is read, a duplication prevention control signal is also read at the same time.

Further, the duplication prevention control signal may have a content of generation restriction such as permitting only the first generation duplication, a signal indicating prohibition or permission of duplication of the video signal, or the like. The description will be made assuming that it is composed of bits or several bits.

As shown in FIG. 1, an output device 10 according to this embodiment includes a reading unit 11, a decoding unit 12, a duplication prevention control signal extracting unit 13, a synchronization separating unit 14, a PN code generation controlling unit 15, (SS is an abbreviation for spread spectrum; hereinafter the same)
Conversion circuits 191 and 192 are provided.

The reading section 11 extracts a reproduced video signal component S2 from the signal S1 obtained by reproducing the recording medium 100, and supplies this to the decoding section 12 and the duplication prevention control signal extracting section 13.

The decoding section 12 performs a decoding process on the reproduced video signal component S2 to form a digital video signal,
This is supplied to the D / A conversion circuit 191. The D / A conversion circuit 191 performs D / A conversion of the digital video signal to form an analog video signal S3 having a synchronization signal, and supplies the analog video signal S3 to the synchronization separation unit 14 and the addition unit 17.

The anti-duplication control signal extractor 13 extracts the anti-duplication control signal S4 added to the reproduced video signal component S2 and supplies it to the SS anti-duplication control signal generator 16.

On the other hand, the synchronization separation section 14 extracts the horizontal synchronization signal H and the vertical synchronization signal V from the analog video signal S3 and supplies them to the PN code generation control section 15.

The PN code generation control section 15 uses the horizontal synchronizing signal H and the vertical synchronizing signal V as reference signals, and
A PN code reset timing signal RE for starting code generation and a clock signal PNCLK are generated.

FIG. 2 is a block diagram for explaining the PN code generation control section 15 of this embodiment. As shown in FIG. 2, the PN code generation control unit 15 of this embodiment
Are the PN code reset timing signal generator 151, P
N clock generator 152, timing signal generator 153
PN code reset timing signal generator 151
Is supplied with the vertical synchronization signal V from the synchronization separation unit 14,
The horizontal synchronization signal H from the synchronization separation unit 14 is supplied to the PN clock generation unit 152 and the timing signal generation unit 153.

PN code reset timing signal generator 1
Reference numeral 51 denotes a spreading PN used for spread spectrum using the vertical synchronization signal V as shown in FIG. 3A as a reference signal.
A vertical cycle reset signal RE (see FIG. 3B) that determines the repetition cycle of the code string is generated. In this example, the reset signal RE is a signal of a vertical cycle rising at the leading edge of the vertical synchronization signal V.

The PN clock generator 152 is a PN clock PNC synchronized with the horizontal synchronization signal H as shown in FIG. 3D.
Generate LK. The PN clock PNCLK determines the chip period of the spreading code.
A PN clock PNCLK having a horizontal period is generated as shown in FIG.

The timing signal generator 153 generates various timing signals used in the output device 10 based on the horizontal synchronizing signal H.

Then, the PN code reset timing signals RE and PN generated by the PN code generation controller 15 are generated.
The clock signal PNCLK is supplied to the SS duplication prevention control signal generation unit 16.

The SS anti-duplication control signal generating section 16 spreads the spectrum of the anti-duplication control signal S4 extracted by the anti-duplication control signal extracting section 13 using a PN code string, and spreads the spectrum to superimpose on the video signal S3. The duplication prevention control signal (hereinafter referred to as SS duplication prevention control signal) S5 is formed.

FIG. 4 is a block diagram for explaining the SS duplication prevention control signal generator 16 according to this embodiment.
As shown in FIG. 4, the SS duplication prevention control signal generation unit 16
Has a duplication prevention control signal sequence generation unit 161, a PN code sequence generation unit 162, and a multiplication circuit 163.

The anti-duplication control signal S4 from the anti-duplication control signal extracting unit 15
, A timing signal TM, and a PN clock signal PNCL.
K is supplied. In this case, the timing signal TM indicates the timing of the delimitation for each bit of the duplication prevention control signal S4.

Then, the duplication prevention control signal sequence generator 161
Generates a duplication prevention control signal sequence FS by outputting the duplication prevention control signal S4 for each bit for a predetermined number of clocks, and supplies this to the multiplication circuit 163.
In this case, the duplication prevention control signal sequence generation unit 161 generates a low-bit duplication prevention control signal sequence FS of 1 bit to several bits instructing duplication prohibition, duplication permission, and the like so as to be completed within one vertical section. To do.

The PN code sequence generator 162 is supplied with the clock signal CLK, the enable signal EN, and the PN code reset timing signal RE. Enable signal EN
Is a signal for putting the PN code string generation unit 162 into an operating state. In this embodiment, the signal is generated by turning on the power to the output device 10 and transmitted to the PN code string generation unit 162. Supplied.

The PN code sequence generator 162 is enabled to operate according to the enable signal EN. And P
The N code sequence generation unit 162 is reset at every rising edge of the PN code reset timing signal RE, and generates a PN code sequence PS having a predetermined code pattern from the beginning according to the PN clock signal PNCLK. That is, as shown in FIG. 3C, the PN code string PS repeats in one vertical cycle, and one chip is allocated to one horizontal section.

FIG. 5 is a diagram showing an example of the configuration of the PN code sequence generator 162. The PN code sequence generation unit 162 in this example includes:
Eight D flip-flops REG1 to REG8 constituting an eight-stage shift register, and an exclusive OR circuit EX for calculating an appropriate tap output of the shift register
-OR1 to EX-OR3. Then, the PN code sequence generation unit 162 illustrated in FIG.
Based on the enable EN, the PN clock signal PNCLK, and the PN code reset timing signal RE, the M series P
Generate an N code sequence PS. The PN code string PS generated by the PN code string generation unit 162 is supplied to the multiplication circuit 163.

The clock rate of the clock PNCLK supplied to the PN code string generation unit 162 in FIG.
In the case of the video signal of the C system, the horizontal frequency is 1
At 5.734 kHz, one vertical section contains 255 chips.

FIG. 6 is a diagram for explaining the state of generation of the PN code generated by the PN code string generation unit 162, that is, the mapping of the PN code to the video signal. As described above, in this embodiment,
The PN code sequence generation unit 162 sets one vertical section as one cycle,
PN code string PS that generates one chip per horizontal section
Generate

FIG. 6 shows a case where one vertical section is composed of four horizontal sections for the sake of simplicity. As shown in FIG. 6, in this example, the PN code sequence generation section 162 uses For each horizontal section, a PN code string PS composed of chips 1, 2, 3, and 4 having separate data is generated. And this PN code string PS is
PN code reset timing signal RE, clock signal P
In each field (vertical section), the same timing is repeatedly generated at the same timing based on NCLK.

As a result, as shown in FIG. 6, chips having different data are generated in the vertical direction in units of one horizontal section, but the same chip is generated in the horizontal direction.
Chips having the same data are also arranged repeatedly in the time axis direction. Since the anti-duplication control signal is completed in one vertical section, conceptually as an SS anti-duplication control signal, as shown in FIG.
The same chip was formed in the horizontal direction and the time axis direction. 4
There are two planes.

Therefore, this PN code string PS is, for example, superimposed on the video signal as it is, and as described above, when noise removal using the correlation of the video signal is performed, the adjacent field Even if a difference is taken between adjacent frames, the PN code string PS composed of the PN code chips 1, 2, 3, and 4 is not detected as a difference, and the obtained difference is regarded as noise and removed. Is performed, the PN code string PS is not removed.

As described above, when an image is enlarged or reduced in the horizontal direction, pixels are deleted and interpolation is performed.
Since the chips are allocated, the original PN data is not damaged even if the horizontal pixel data is deleted or interpolated.

Further, even if field thinning or field interpolation is performed, the chip having the same data in the time axis direction is generated, so that the original PN data remains intact.

As described above, in this embodiment,
It is possible to generate a PN code string PS that does not change the data on the data plane shown in FIG. 6 even if noise removal using the correlation of the video signal and interpolation or thinning out in the horizontal and vertical directions are performed. it can.

The multiplication circuit 163 uses the PN code string PS generated as described above to generate a duplication prevention control signal string F.
S is spread spectrum to form an SS duplication prevention control signal S5. As described above, the duplication prevention control signal S4 is
The multiplication circuit 163 is supplied to the multiplication circuit 163 as a duplication prevention control signal sequence FS that is completed within an effective screen section of one vertical section, and the spectrum is spread so as to be completed by a PN code string PS for one cycle.

That is, even if the anti-duplication control signal S4 indicates the control content of anti-duplication control with one bit,
Even if a plurality of bits, such as two bits or three bits, indicate the control content of the anti-duplication control, the spectrum is spread using the PN code string PS for one cycle. As described above, since the duplication prevention control signal S3 is spread spectrum so as to be completed by the PN code string PS for one cycle, the same SS duplication prevention control signal S5 is formed corresponding to each vertical section.

The SS anti-duplication control signal S 5 formed in the SS anti-duplication control signal generator 16 is supplied to the D / A conversion circuit 192. The D / A conversion circuit 192
The anti-duplication control signal S5 is converted into an analog SS anti-duplication control signal S5A and supplied to the adder 17.

The adder 17 superimposes the analog SS duplication prevention control signal S5A on the analog video signal S3,
An output video signal S6A is formed and output. As described above, the adder 17 adds P to the analog video signal S3.
It has a function as superimposing means for superimposing the SS anti-duplication control signal S5A, which is the anti-duplication control signal spectrum-spread by the N code string PS.

In this case, noise removal using correlation between adjacent fields and frames, thinning and interpolation of horizontal pixels for horizontal reduction and enlargement of an image,
Even when thinning or interpolation in the time axis direction, that is, when field thinning or interpolation is performed, SS duplication prevention in the horizontal direction and time axis direction of an image formed by a video signal on which an SS duplication control signal is superimposed. As the data sequence of the control signal, a data sequence in which the content does not change can be formed.

Therefore, in the output device 10 or a device such as a recording device which receives supply of a video signal from the output device 10 or a device which receives the supply of the video signal from the output device 10 and the output device 10 In the case where the noise removal using the correlation of the video signal and the interpolation or thinning in the horizontal direction or the time axis direction are performed as described above, the anti-duplication control signal (SS The anti-duplication control signal) can be reliably transmitted by being superimposed on the video signal and provided to a subsequent device.

Further, since the anti-duplication control signal is spread spectrum and superimposed on the video signal, the anti-duplication control signal superimposed on the video signal does not degrade the video signal, and the video signal can be easily reproduced. The SS duplication prevention control signal is not removed from the signal.

FIG. 7 shows the relationship between the anti-duplication control signal and the main information signal, in this example, the video signal in the form of a spectrum. The anti-duplication control signal contains a small amount of information, is a low bit rate signal, and is a narrow band signal as shown in FIG. When this is subjected to spectrum spreading, a signal having a wide bandwidth as shown in FIG. 7B is obtained. At this time, the spread spectrum signal level decreases in inverse proportion to the band expansion ratio.

This spread spectrum signal, that is, S
The S duplication prevention control signal S5A is superimposed on the information signal by the adder 17. In this case, as shown in FIG. 7 (c), the level of the S duplication prevention signal S5A is smaller than the dynamic range of the video signal as the information signal. The duplication prevention control signal S5A is superimposed. By superimposing in this way, deterioration of the main information signal can hardly occur. Therefore, as described above, when the video signal on which the SS anti-duplication control signal is superimposed is supplied to the monitor receiver and the video is reproduced, the influence of the SS anti-duplication control signal is almost negligible. Is obtained.

On the other hand, as will be described later, in order to detect the SS anti-duplication control signal on the recording side, when the inverse spread spectrum is performed, as shown in FIG. Is restored. By providing a sufficient band spreading factor, the power of the anti-duplication control signal after despreading exceeds that of the information signal and becomes detectable.

In this case, since the SS anti-duplication control signal superimposed on the analog video signal is superimposed on the analog video signal at the same time and within the same frequency, deletion and modification are not possible by replacing the frequency filter or simple information. It is possible.

Therefore, the SS duplication prevention control signal superimposed on the video signal is not removed, and the SS duplication prevention control signal can be reliably provided to devices such as a monitor receiver and a recording device.

Thus, the SS duplication prevention control signal S5A
Is supplied to a monitor receiver for displaying an image and a recording device 20 to be described later.

Next, the recording device 20 that receives the supply of the video signal S6A from the output device 10 and records the video signal will be described.

FIG. 8 is a diagram for explaining a video signal recording device (hereinafter simply referred to as a recording device) 20 used in the video signal duplication control system of this embodiment. That is, the recording device 20 corresponds to the recording system of the DVD device in the first embodiment.

As shown in FIG. 8, the recording device 20 includes an encoding unit 21, a synchronization separation unit 22, a PN code generation control unit 23,
A detection unit (hereinafter, referred to as an SS duplication prevention control signal detection unit) 24 that detects a duplication prevention control signal that is spread spectrum and superimposed on a video signal; a duplication control unit 25 that performs control such as permitting or prohibiting duplication; 26, and an A / D conversion circuit 291. The recording medium 200 is a DVD to which a video signal is written by the recording device 20.

The video signal S6 supplied from the output device 10
A is converted into a digital video signal S21 by an A / D conversion circuit 291 and is encoded by the encoding unit 21, the synchronization separation unit 22,
It is supplied to the SS duplication prevention control signal detection unit 24.

The encoding section 21 converts the digital video signal S21
In response to the supply of, the video synchronization signal is removed, or performs encoding processing such as data compression of the digital video signal,
Digital video signal S for recording supplied to recording medium 200
22 is formed and supplied to the writing unit 26.

The synchronization separating section 22 extracts the horizontal synchronizing signal H and the vertical synchronizing signal V from the digital video signal S21 before being subjected to the encoding processing, and outputs them to the PN code generation control section 2.
Supply 3

In this embodiment, the PN code generation control unit 23 of the recording device 20 is configured in the same manner as the PN code generation control unit 15 of the output device 10 described above with reference to FIG. Therefore, here, the PN code generation control unit 23 will be described as having the configuration shown in FIG.

The PN code reset timing signal generation section 151 of the PN code generation control section 23 uses the vertical synchronization signal V as a reference signal, and corresponds to the output device 10 described above.
A PN code reset timing signal RE for providing a reset timing of a PN code sequence for despreading used for spectrum despreading is generated. The PN code reset timing signal RE generated here is based on the P
This signal is the same as the PN code reset timing signal generated by the N code generation control unit 15, and provides a timing corresponding to the start position of the vertical section of the video signal.

The PN clock generation section 152 of the PN code generation control section 23 generates a PN clock signal PNCLK synchronized with the horizontal synchronization signal H. This clock signal PNCL
K is a signal having the same frequency as the clock signal PNCLK used in the output device 10 described above. Also, PN
The timing signal generation unit 163 of the code generation control unit 23
Various timing signals are generated based on the horizontal synchronization signal H.

The PN code reset timing signal RE and the clock signal PNCLK generated by the PN code generation control unit 23 are supplied to the SS duplication prevention control signal detection unit 24.

In this embodiment, the SS anti-duplication control signal detection section 24 includes a PN code generator and a multiplying circuit, performs spectrum despreading, and extracts the anti-duplication control signal superimposed on the video signal S21. It has a function as spectrum despreading means.

The SS anti-duplication control signal detecting section 24
Sign reset timing signal RE, clock signal PNC
A PN code sequence for despreading is generated according to the LK. The PN code sequence for despreading has one vertical section as one cycle, and has the same code pattern as the PN code sequence PS used in the output device 10 for spectrum spreading of the duplication prevention control signal.

Then, the SS duplication prevention control signal detecting section 24
Is the P used in the spread spectrum for the video signal in each vertical section on which the SS duplication prevention control signal is superimposed.
Spectrum despreading is performed using the PN code sequence for despreading, which is the same PN code sequence as the N code sequence, to extract a duplication prevention control signal superimposed on the video signal. The extracted duplication prevention control signal S24 is supplied to the duplication control unit 25.

The duplication control unit 25 outputs a duplication prevention control signal S2
4 is decoded to determine whether the video signal supplied to the recording device 20 is a signal whose duplication is prohibited or whose duplication is permitted. Then, based on the determination result, a write control signal S25 is generated, and this is
, Thereby performing copy prevention control such as permission and prohibition of writing of the video signal S22.

The writing section 26 has a write control signal S2
5 permits writing, the video signal S
22 is written to the recording medium 200, and if the write control signal S25 prohibits the writing, the video signal S22 is not written to the recording medium 200.

As described above, the recording apparatus 2 of this embodiment
0 corresponds to the output device 10, and performs inverse spectrum spreading on the video signal on which the SS anti-duplication control signal is superimposed by using the same PN code sequence as used in the spread spectrum of the anti-duplication control signal. To extract the duplication prevention control signal superimposed on the video signal.

In this case, as described above, the SS duplication prevention control signal having the same data in the horizontal direction and the time axis direction is superimposed on the video signal output from the output device 10.

Therefore, as described above, even when noise removal utilizing the correlation of the video signal is performed, the SS duplication prevention control signal superimposed on the video signal is not removed. In addition, when deletion or interpolation is performed in the horizontal direction or the time axis direction of an image, the SS superimposed on the video signal
The copy protection control signal is not damaged.

For this reason, the SS duplication prevention control signal is degraded even when the aspect ratio is converted, the variable speed reproduction is performed, or the so-called cut editing is performed at the time of input to the recording apparatus. Therefore, the control content of the duplication prevention control indicated by the SS duplication prevention control signal is not lost.

For this reason, in the recording device 20, it is possible to reliably and accurately extract the anti-duplication control signal that is spread spectrum and superimposed on the video signal, and to perform anti-duplication control according to the extracted anti-duplication control signal. it can.

Further, the output device 10 and the recording device 20 generate the PN code reset timing signal RE using the vertical synchronization signal as a reference signal. Can generate a PN code sequence at the same timing.

Thus, the recording apparatus 20 detects a PN code string in which the anti-duplication control signal superimposed on the video signal is spectrum-spread using, for example, a sliding correlator or the like, and reversely detects the PN code string at the same timing. Since there is no need to perform phase control to generate a PN code sequence for spreading, it is possible to quickly extract a duplication prevention control signal by inverse spectrum spreading.

As described above, in the output device 10 and the recording device 20, since the frequency of the clock signals CLK and CLK1 is determined using the horizontal synchronization signal as the reference signal, both the output device 10 and the recording device 20 are used. At
Clock signals of the same frequency can be reliably generated.

In the above-described embodiment, in the output device 10 and the recording device 20, the SS duplication prevention control signal is superimposed on all sections of the video signal.
Excluding vertical and horizontal blanking periods,
The SS duplication prevention control signal may be superimposed only on the valid screen section. Further, the SS duplication prevention control signal does not have to be superimposed on the entire effective screen area. For example, it is also possible to set finely based on the horizontal synchronization signal, for example, from several clocks to several tens of clocks from the leading edge of the horizontal synchronization signal.

The PN clock signal PNCLK is a clock having a horizontal period so that one chip is allocated to each horizontal section. However, a PN clock signal PNCLK having two horizontal periods as shown in FIG.
One chip may be allocated to two horizontal sections using the N clock signal PNCLK. Further, a PN clock signal PNCLK having a plurality of horizontal cycles of three or more horizontal cycles
May be used to generate a PN code having a repetition period of one vertical period.

The period of the PN code is not limited to one vertical period. For example, the PN code may be set to 0.5 vertical period and repeated twice in one vertical period.
N codes may be generated.

In the above-described embodiment, the analog connection in which an analog video signal is supplied from the output device 10 to the recording device 20 has been described. However, the present invention is also applicable to a digital connection. Is also good.

That is, the spread-spectrum anti-duplication control signal can be superimposed on an analog video signal or a digital video signal.

In the recording device 20, the video signal to be supplied to the SS anti-duplication control signal detection unit is filtered in advance, and the low-level video in which the spectrum anti-duplication control signal is superimposed is superimposed. A signal may be extracted and supplied to the SS duplication prevention control signal detection unit.

In the above-described embodiment, the output device and the recording device are both described as DVD devices. However, the present invention is not limited to this.
The present invention can also be applied to R, video disk and video CD output devices and recording devices. That is, the present invention can be applied to both analog devices such as analog VTRs and digital devices such as DVD devices.

In the above-described embodiment, the anti-duplication control signal added to the video signal recorded on the recording medium 100 is extracted, and this is spectrum-spread using the PN code, and recorded. Although the video signal is superimposed on the video signal supplied to the device 20, a recording medium on which a video signal on which a spectrum prevention duplication control signal is superimposed in advance may be used.

That is, for a video signal to be recorded on a recording medium, the anti-duplication control signal is spectrum-spread so as to be completed within one vertical section using, for example, a PN code string having one vertical section as one cycle. The anti-duplication control signal subjected to spectrum spreading is superimposed on the video signal. A recording medium on which the video signal on which the anti-duplication control signal thus spread in spectrum is superimposed is recorded is created.

As described above, in the case of a recording medium on which a video signal on which a spectrum-spread anti-duplication control signal is superimposed in advance is recorded, the anti-duplication control signal is taken out.
It is not necessary to perform processes such as generation of a PN code, spread spectrum, and superposition of the spread spectrum copy control signal on the video signal in the output device. That is, in this case, the output device only needs to reproduce and output the video signal recorded on the recording medium.

In this case, on the recording apparatus side, the same code pattern as that of the PN code string for which the SS anti-duplication control signal superimposed on the video signal is spread spectrum is used similarly to the recording apparatus 20 of the above-described embodiment. PN for despreading
A code string is generated for the video signal at the same timing as when the spectrum is spread, and spectrum despreading is performed using the generated code string, whereby a duplication prevention control signal superimposed on the video signal can be extracted.

When the anti-duplication control signal, which has been spectrum-spread, is preliminarily superimposed on the video signal recorded on the recording medium, the function of extracting the anti-duplication control signal by despreading the spectrum to the recording apparatus is provided. If so, the duplication prevention control signal superimposed on the video signal in advance can be extracted and the duplication control can be effectively performed.

Further, the output unit is provided with a duplication preventing control signal generating unit, and the duplication preventing control signal generated in the output unit is spectrum-spread using a PN code string, and is output by being superimposed on a video signal. You may.

In this case, even when the anti-duplication control signal is not originally recorded on the recording medium, or when the anti-duplication control signal subjected to spectrum spreading is not superimposed, the video signal is generated by the output device. The duplication control can be performed on the recording apparatus side by using the duplication prevention control signal superimposed on the data.

In the above-described embodiment, the output device as a DVD device is used as the duplication prevention control device.
Although the case of the recording device has been described, the present invention is not limited to this. For example, the present invention can be applied to a case where the present invention is applied to a television signal output device on a broadcasting station side and a television signal to be transmitted is superimposed with a spectrum spread duplication prevention control signal and transmitted. . And
On the receiving side, despread spectrum is performed to extract a duplication prevention control signal sequence superimposed on the video signal,
The duplication prevention control of the video signal can be performed based on this duplication prevention control signal.

Of course, the present invention can be applied to a video output device and a video reception device for transmitting and receiving a video signal via a cable, such as a cable television.

Further, in the above-described embodiment, the anti-duplication control signal is superimposed as the additional information. However, the additional information superimposed on the video signal is not limited to the anti-duplication control signal.

For example, copyright information for identifying the copyright holder of the video reproduced by the video signal may be superimposed on the video signal by spectrum spreading. In this case, the copyright information superimposed on the video signal can be extracted by inverse spectrum spreading and the copyright owner can be confirmed, which helps prevent copyright infringement and allows the copyright owner to copy the copyright. In the case where the video possessed is used without permission or the like, it is possible to easily indicate that it is a copyright infringement.

As described above, noise removal using the correlation of the video signal, thinning and interpolation of horizontal pixels formed by the video signal, and field thinning and interpolation in the time axis direction are performed. In such a case, the copyright information is not removed or deteriorated, so that the copyright information can be reliably taken out and used.

[0127]

As described above, according to the video signal transmission method, the superimposition information extraction method, the video signal output device, the video signal receiving device, and the video signal recording medium according to the present invention, the video signal is written in the horizontal direction and in the horizontal direction. Additional information that is made to have the same data in the time axis direction is repeatedly superimposed. Accordingly, the additional information superimposed on the video signal by the spread spectrum is not removed or deteriorated by the noise removal using the correlation of the video signal.

Further, when the video signal is thinned or interpolated in the horizontal direction or thinned or interpolated in the time axis direction, even if the video signal changes, even if the video signal changes, the additional information superimposed on the video signal by spectrum spreading is superimposed. Changes can be prevented.

As a result, it is possible to reliably transmit the additional information that has been spectrum-spread and superimposed on the video signal, and the receiving side can reliably transmit the additional information that has been spread and superimposed on the received video signal. Can be detected.

[Brief description of the drawings]

FIG. 1 is a block diagram for explaining an embodiment of a video signal output device according to the present invention.

FIG. 2 is a block diagram for explaining an example of a PN code generation control unit of the video signal output device shown in FIG.

3 is a diagram for explaining an example of a PN code generation timing signal generated in the video signal output device shown in FIG.

FIG. 4 is a diagram for explaining an example of an SS duplication prevention control signal generation unit of the video signal output device shown in FIG. 1;

FIG. 5 is a diagram illustrating an example of a PN code generator used in an SS duplication prevention control signal generation unit of the video signal output device shown in FIG. 1;

FIG. 6 is a conceptual diagram for explaining a generation state (mapping) of a PN code used in the video signal output device shown in FIG.

FIG. 7 is a diagram showing a relationship between an SS duplication prevention control signal and a video signal in a spectrum.

FIG. 8 is a block diagram for explaining an embodiment of a video signal recording device to which the video signal receiving device according to the present invention is applied.

FIG. 9 is a block diagram for explaining a conventional configuration of a duplication prevention control system.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Video signal output device, 11 ... Readout part, 12 ... Decoding part, 13 ... Duplication prevention control signal extraction part, 14 ... Synchronization separation part, 15 ... PN code generation control part, 16 ... SS duplication prevention control signal generation part , 17 ... Addition unit, 20 ... Video signal recording device, 21 ... Encoding unit, 22 ... Sync separation unit, 23 ... PN code generation control unit, 24 ... SS duplication prevention control signal detection unit, 2
5: replication control unit, 26: writing unit, 191, 192 ...
D / A conversion circuit, 291: A / D conversion circuit, 100: reproduction side recording medium, 200: recording side recording medium

Claims (13)

[Claims] 1. A transmission method for superimposing spectrum spread additional information on a video signal and transmitting the superimposed information, wherein a period within one vertical period is defined as one cycle based on a synchronization signal, and a time in a horizontal direction and a screen unit is used. The same spreading code is repeatedly generated in the spatial direction that is the axial direction, and the additional information is spectrum-spread using the spreading code so as to be completed in the section within the one vertical section. A video signal transmission method, wherein information is transmitted while being superimposed on the video signal. 2. The video signal transmission method according to claim 1, wherein the section within one vertical section is an effective screen section. 3. The video according to claim 1, wherein the additional information is anti-duplication control information for performing anti-duplication control on a video signal on which the additional information is superimposed. Signal transmission method. 4. A spread code repeatedly generated so as to be the same in a horizontal direction and a spatial direction which is a time axis direction of a screen unit, with one period as one period within a vertical period based on a synchronization signal. A superimposition information extraction method for extracting the additional information from a video signal on which additional information that has been spectrum-spread so as to be completed within a vertical section is superimposed, wherein the additional information is synchronized with a synchronization signal and is spread. By repeatedly generating a despreading code having a period within one vertical section as one cycle corresponding to the section in which the information is superimposed, and performing spectrum despreading using the generated despreading code, A method for extracting superimposed information, wherein the additional information superimposed on a video signal is repeatedly extracted. 5. A spread code repeatedly generated so as to be the same in a horizontal direction and a spatial direction which is a time axis direction of a screen unit, with a period within one vertical period as one cycle based on a synchronization signal. Spreading code generating means, Spread spectrum using the spreading code generated by the spreading code generating means, spread spectrum of the additional information, to generate a spread spectrum signal completed in the section within the one vertical section, A video signal output device, comprising: superimposing means for superimposing the spread spectrum signal from the spread spectrum means on the video signal. 6. The video signal output according to claim 5, wherein said spread code generating means repeatedly generates a spread code by setting an effective screen section within one vertical section as a section within said one vertical section. apparatus. 7. The apparatus according to claim 1, wherein said additional information spectrum-spread by said spread spectrum means is anti-duplication control information for performing anti-duplication control on a video signal on which said additional information is superimposed. The video signal output device according to claim 5 or 6. 8. A spread code repeatedly generated so as to be the same in a horizontal direction and a spatial direction which is a time axis direction in a unit of a screen, with a period within one vertical period as one cycle based on a synchronization signal. What is claimed is: 1. A receiving apparatus for receiving a video signal on which spectrum spread additional information is superimposed so as to be completed in a section within a vertical section, wherein the section is synchronized with a synchronization signal and the spectrum spread additional information is superimposed. A spread spectrum means for generating a spread code for despreading with one section within one vertical section as one cycle; and performing the spectrum despread using the generated despread code to obtain the image. And a spectrum despreading means for repeatedly extracting the additional information superimposed on the signal. 9. The image processing apparatus according to claim 1, wherein the additional information is an anti-duplication control signal for a video signal on which the additional information is superimposed, and wherein the received video signal is received in accordance with the additional information extracted by the inverse spread spectrum means. 9. The video signal receiving apparatus according to claim 8, further comprising a duplication control means for performing duplication prevention control. 10. A video signal transmission / reception device comprising: a video signal output device for superimposing spectrum spread additional information on a video signal and outputting the video signal; and a video signal reception device for receiving the video signal output from the video signal output device. The video signal output device, wherein a period within one vertical section is defined as one cycle based on a synchronization signal, and is repeated so as to be the same in a spatial direction which is a horizontal direction and a time axis direction of a screen unit. A spread code generating means for generating a generated spread code; and a spread spectrum signal for the additional information using the spread code generated by the spread code generating means, and a spread spectrum signal completed in an interval within one vertical interval. Generating a spread spectrum means, and superimposing the spread spectrum signal from the spread spectrum means on the video signal. Means, and wherein the video signal receiving apparatus synchronizes with a synchronizing signal, and corresponds to a section in which the spectrum-spread additional information is superimposed, and has a period within one vertical section as one cycle. Spectrum spreading means for generating a spreading code for, and spectrum despreading means for repeatedly extracting the additional information superimposed on the video signal by performing spectrum despreading using the generated despreading code, A video signal transmission / reception system comprising: 11. The video signal output device, wherein the spread code generating means repeatedly generates a spread code by setting an effective screen section within one vertical section as a section within the one vertical section. The video signal transmission / reception system according to claim 10. 12. The anti-duplication control information for performing anti-duplication control on a video signal on which the additional information is superimposed, wherein the video signal receiving device is extracted by the inverse spectrum spreading means. 11. A duplication control means for performing duplication prevention control of the received video signal in accordance with the additional information obtained.
Alternatively, the video signal transmission / reception system according to claim 11. 13. A period within one vertical section is defined as one cycle based on the synchronization signal, and a spreading code repeatedly generated so as to be the same in the horizontal direction and in the spatial direction which is the time axis direction of the screen unit is used. A video signal recording medium that records a video signal on which additional information that has been spread spectrum so as to be completed within a vertical section is superimposed.