JP2005244859A - Device for adding copyright management information, and detecting/processing device of copyright management information - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent illegal copying of high-quality video contents made up of analog video signals directly in a digital recording/reproducing device. <P>SOLUTION: In the device for adding copyright management information, an input analog video signal is separated to a brightness signal and a color signal. A block, of which a luminance mean level is lowest, is detected in a frame, and the positional information and copyright management information (CGMS-A) are recorded at a prescribed position in a blanking interval. An auxiliary signal including high luminance signal is added to the block, and the processed luminance signal is synthesized with a color signal and generated as an output. In a copyright management information detecting/processing device, the copyright management information and addition position information of the auxiliary signal are detected, and then the auxiliary signal is detected from a block indicated by addition position information. According to a detection condition of each information/signal, permission/disapproval of recording is determined. In this way, in a simple constitution, a copyright protective system with high tolerance can be constituted. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an apparatus for adding copyright management information and a detection / processing apparatus for the information, and more particularly to prevent illegal copying (copying or dubbing) of video content input as an analog signal in a digital recording / reproducing apparatus. Relating to the device.

In recent years, with the widespread use of digital recording and playback devices, it has become easy to enjoy high-quality music and video content, but since digital content can be copied without deterioration, the importance of copyright protection Is growing.
In addition, with the advent of the full-fledged multimedia era, there is a need for a technology that effectively prevents illegal duplication of digital contents as well as the establishment of a legal system for copyright protection.

  In this trend of digitization, various measures have been devised to prevent duplication with a focus on digital signals. However, analog signals are used to prevent copying at analog inputs in digital recording / reproducing devices. Recently, there has been a tendency not to be omitted much because copying always involves some degradation.

However, with the development of digital recording / playback devices, the display quality has been improved, and the analog / digital conversion circuit has become more sophisticated. It has become possible to output digital signals as analog signals while maintaining high quality.
In other words, when copying is performed using analog signals via these devices, the quality is almost the same as when copying digital signals via high-quality analog signals, even if there is some degradation. A copy will be obtained.

Therefore, recently, there has been a strong demand from content creators and copyright holders to prevent copying of analog input / output in digital recording / reproducing apparatuses.
As for the problem, since it has been necessary to prevent illegal copying when providing a video signal for recording / playback or broadcasting of an analog video signal, various copy prevention methods have been proposed. Yes.

For example, in Patent Document 1 below, as shown in FIG. 17A, recording / reproduction is performed by applying a luminance signal with an excessive amplitude exceeding the amplitude level of a normal luminance signal within the blanking period of the video signal. The AGC (automatic gain adjustment) circuit of the apparatus is malfunctioning, and the amplitude of the subsequent video signal is recorded in a state in which the amplitude is controlled lower than the original level due to malfunction of the AGC circuit.
Specifically, recording is performed by inserting a pulse larger than the normal AGC reference level in the AGC reference level detection section of the video signal, and as shown in FIG. A pseudo SYNC pulse is inserted in part.
In the pseudo SYNC pulse in the figure, five waves are inserted at a level obtained by adding level p to the horizontal synchronizing pulse after the burst signal at 1H.
Meanwhile, as shown in FIG. 17C, there are many types of analog video tape recorders for home use in which AGC is applied using a 1H horizontal synchronizing pulse in a vertical blanking period.
Therefore, when a pseudo SYNC pulse having an amplitude larger than that of the horizontal sync pulse is inserted into a reference interval, the AGC circuit determines that the amplitude of the pseudo SYNC pulse is a reference level, and AGC is applied. As a result, AGC is applied. Since the level is detected as the level of the pseudo SYNC pulse, the original SYNC cannot be detected, and a normal image is not output, and illegal copying can be prevented.

Further, in Patent Document 2 below, by utilizing the standardization of a method for adding an identification signal called VBID within a blanking period of a video signal, copy protection (copyright protection) is applied to those VBID signals. ) Proposals have been made to superimpose information.
VBID is 20-bit digital data displayed with a reference signal of 70 IRE and an amplitude of 70 IRE or 0 IRE, and is inserted into an effective video portion of a predetermined 1H line and used as an identification signal.
Specifically, the configuration is as shown in FIG.
Bit Nos. 1 and 2 are wide IDs, and the No. 1 bit indicates the transmission aspect ratio [4: 3 when “0” and 16: 9 when “1”]. Indicates the screen format [normal display when “0”, letterbox display when “1”].
Bits Nos. 3 to 6 are mode IDs, and an identification signal relating to copyright is transmitted when “0000”. In this case, bit No. 7 is set to “0” and “no copyright”. , “1” is defined as “with copyright”.
Bit No. 8 is defined as image data or audio data sent as “0” as “original” and “1” as “not original (dubbed)”.
That is, SCMS (Serial Copy Management System) information is transmitted using bits Nos. 7-8.
Bit numbers 15 to 20 are CRCC (Cyclic Redundancy Check Character).
As described above, the VBID standard originally transmits information such as the aspect ratio of a TV signal, but is also used for transmission of copyright protection information because it is easy to add and detect signals.

JP 63-107281 A JP 2002-344908 A

In the case of the copy prevention method of Patent Document 1, the copy prevention signal is inserted within a period (VB: video blanking period) that does not affect the display of the effective portion of a normal video signal. It is possible to remove the signal applied during the blanking period without changing the effective image range, and if the applied luminance signal having an excessive amplitude is removed, the effectiveness is lost.
Also, in Patent Document 2, since only the blanking period of the video signal is used, copyright protection information can be removed without affecting the display of the effective portion of the video signal. There is a problem similar to the case of.
Then, a person who is familiar with the two methods manufactures a device that removes or replaces the copy protection signal inserted in a predetermined section of the blanking period of the video signal, and these devices are sold as a “copy guard removal device”. It is also true that illegal copies of content are frequently made.

On the other hand, to compensate for these shortcomings, a copyright identifier called a “watermark” is recently embedded in the content itself in an invisible state, and the recording / playback is stopped by detecting the copyright identifier during recording / playback. A method for controlling the reproduction of the image has also been proposed.
The “watermark” embedded in the content itself is an excellent method with little risk of removing the embedded copyright identifier from the content regardless of the medium or transmission path, regardless of whether the signal format is analog or digital. is there.
However, the basic premise is complex digital data processing such as a data diffusion method, which involves complicated processing during addition and playback, which requires a large processing circuit. Considering its effectiveness and the cost of incorporation into equipment. However, the current situation is that they are not so often adopted.

  Therefore, in view of the above-described problems, the present invention provides a digital image recording / playback apparatus that can prevent an illegal copy of video content input as an analog signal and prevent a predetermined image block from being displayed on an effective screen display portion. It was created for the purpose of providing a device for adding copyright management information including display and detecting / processing the copyright management information.

  According to a first aspect of the present invention, there is provided an apparatus for adding copyright management information to an analog video signal, a signal separation unit for separating a luminance signal from an input analog video signal, and a frame or a field portion separated by the signal separation unit. The signal dividing means for dividing the luminance signal into a plurality of blocks in a manner of dividing the screen, and the average level of the luminance signal is the lowest among the blocks for one frame or one field divided by the signal dividing means A position information calculating means for detecting position information of the detected block, a storage means for storing inputted copyright management information, and a predetermined image signal of the block size including a high luminance signal. Auxiliary signal generating means for generating auxiliary signals, copyright management information in the first storage means, and the position of the block obtained by the position information calculating means Information adding means for adding information to each predetermined position within a blanking period of the luminance signal separated by the signal separating means, and a block obtained by the position information calculating means in the luminance signal separated by the signal separating means Signal adding means for adding an auxiliary signal generated by the auxiliary signal generating means to a signal block corresponding to the position information of the signal, and a signal after the signal separating means has separated the luminance signal from the analog video signal A copyright management information adding apparatus comprising: a signal synthesizing means for synthesizing a luminance signal after being subjected to processing by the information adding means and the signal adding means in frame synchronization or field synchronization Concerning.

In the apparatus of the present invention, not only the copyright management information but also the position information of the signal block to which the auxiliary signal is added within the blanking period of the analog video signal.
The auxiliary signal is a predetermined image signal of the block size including a high luminance signal, and is superposed on a block in which the average level of the luminance signal is the lowest among the blocks for one frame or one field. It is added with.
Therefore, for the block, not an image of the original analog video signal but an image including a high-intensity signal by the auxiliary signal is displayed so as to prevent normal viewing of the content, and the block is not an analog video signal. The position changes with time depending on the contents, and the changed position information is recorded in the blanking period of the analog video signal as described above.
The processing by the apparatus of the present invention does not always have to be performed every frame or every field, and may be performed every several frames or every several fields. In the second invention described later, an auxiliary signal is sent one frame before or From the viewpoint of performing the process of replacing with the luminance signal of the corresponding block one field before, it is preferable to perform the process at a certain interval as in the latter case.
In addition, when obtaining the average level of the luminance signal of the block, the average value of the luminance level may be obtained directly. However, the luminance signal is once integrated by an integrating circuit and smoothed to obtain the average value. It is desirable.

  A second invention is a copyright management information detecting / processing device corresponding to an analog video signal processed by the copyright management information adding device according to the first invention, and is based on an input analog video signal. Signal separating means for separating the luminance signal, information detecting means for detecting copyright management information and additional position information of the auxiliary signal from each predetermined position within a blanking period of the luminance signal separated by the signal separating means, and the information On the basis of the additional position information of the auxiliary signal detected by the detecting means, auxiliary signal detecting means for detecting the auxiliary signal from the corresponding block of the luminance signal, and duplication permission information indicated by the copyright management information detected by the information detecting means, Based on the presence or absence of detection of each information by the information detection means and the auxiliary signal detection means, and the state of the auxiliary signal detected by the auxiliary signal detection means, the input analog video signal is detected. Determination means for determining whether recording is permitted / not permitted, signal holding means for always holding the luminance signal one frame before or one field before the luminance signal separated by the signal separation means, and the determination means for recording An auxiliary signal replacement means for replacing a signal block corresponding to the additional position information of the auxiliary signal in the luminance signal after separation with a corresponding signal block held by the signal holding means, when permission is determined; Signal synthesis in which the signal after the signal separation means separates the luminance signal from the analog video signal is combined with the luminance signal after the processing by the auxiliary signal replacement means is performed in frame synchronization or field synchronization. And a copyright management information detection / processing apparatus.

In the apparatus of the present invention, the copyright management information and the auxiliary signal additional position information added by the apparatus of the first invention are detected from the blanking period, and the corresponding block of the luminance signal is used by using the additional position information of the auxiliary signal. Auxiliary signals are detected from the information, and based on the information, permission / non-permission of recording of the analog video signal is determined.
In addition, when the recording permission is determined, the block to which the auxiliary signal is added is replaced with the image signal of the corresponding block one frame before or one field before, and normal using the high correlation of the image signal Record images that can be viewed easily.
Therefore, the analog video signal processed by the apparatus of the first invention cannot be copied or reproduced normally unless the apparatus of the second invention is used.
If the device of the second invention is not used, the protection state cannot be canceled simply by removing the copyright management information. If the copyright management information is to be removed, the auxiliary recorded in the blanking period is also used. If the additional position information of the signal is removed, information for removing the auxiliary signal is lost, and normal viewing of the image cannot be performed.
In addition, since the position of the signal block to which the auxiliary signal is added moves at any time, it is almost impossible to remove this information one by one without obtaining the additional position information of the auxiliary signal.

The copyright management information addition device and copyright management information detection / processing device of the present invention have the following effects based on the above configuration.
The present invention provides a system that is extremely resistant in order to protect copyrights against illegal copying of high-quality video content by an analog video signal as it is in a digital recording / playback apparatus.
In addition, the functional parts such as the signal separating means and the signal dividing means can be realized by an existing video signal processing circuit, and complicated signal processing is not required, so that it is excellent in cost performance built into the device.

Hereinafter, a copyright management information adding device according to the present invention will be described in detail as a first embodiment, and a detection / processing device for the information will be described as a second embodiment with reference to the drawings.
In each embodiment, an analog video signal of NTSC (National Television System Committee) signal system (interlace) is taken as an example.

FIG. 1 is a block circuit diagram of a copyright management information adding device according to this embodiment.
The input video signal is separated into a color signal and a luminance signal by the Y-C separation circuit 1. That is, using a correlation between a color signal and a luminance signal (for example, a phase difference between color signals for each line), separation is performed by a comb filter using a 1H delay line.
The separated luminance signal is input to the timing generation circuit 2, and the circuit 2 has a circuit configuration as shown in FIG.
In the timing generation circuit 2, the clamp level slice circuit 21 detects a composite synchronization signal of a video signal, and the vertical / horizontal synchronization separation circuit 22 separates it into a vertical synchronization signal and a horizontal synchronization signal, and outputs them. locked loop) circuit 23 generates a reference clock corresponding to an integral multiple of the horizontal synchronizing signal based on the vertical synchronizing signal and the horizontal synchronizing signal, and gate signal generating circuit 24 based on the vertical synchronizing signal, the horizontal synchronizing signal, and the reference clock. To generate and output a gate signal for extracting the luminance signal.
Further, in the timing generation circuit 2, the position update timing circuit 25 outputs a position update timing signal according to the preset value given from the update time setting switch 26 using the vertical synchronization signal, the horizontal synchronization signal, and the reference clock. Yes.

The counter circuit 3 has vertical (Y) and horizontal (X) direction counters for calculating the position on the screen, and the vertical synchronizing signal, horizontal synchronizing signal and reference clock output from the timing generating circuit 2 are provided. The count value synchronized with the vertical and horizontal directions of the screen is output based on the above.
Here, the operation of the counter circuit 3 will be specifically described with reference to FIG. However, although it is actually divided into about 128 counts, in order to facilitate understanding, description will be made assuming that 8 divisions in the horizontal direction and 8 divisions × 2 fields in the vertical direction are counted.

The counter circuit 3 is reset by the vertical synchronization signal of the first field and starts counting.
The Y counter is a counter that divides the position in the vertical direction, and outputs a Y count value obtained by dividing the effective screen into 8 vertical blocks per field using a vertical synchronization signal and a reference clock.
The X counter is a counter that divides the position in the horizontal direction, and repeatedly outputs the X count value so that the effective screen of one horizontal synchronization period (1H) is divided into 8 horizontal blocks using the horizontal synchronization signal and the reference clock. To do.
In this embodiment, since the NTSC system (interlace) is used as described above, the Y count value is 0 to 7 in the first field and 8 to 15 in the second field, and each field in one frame depends on the count value. Identified.
By combining the X count value and the Y count value, the position on the video signal divided into 8 × 8 blocks (position on the screen) is specified for every two fields in one frame of the NTSC signal. It will be possible.

In the area detection circuit 4, since the luminance signal separated by the Y-C separation circuit 1 includes a synchronization signal, the luminance extraction gate signal obtained from the timing generation circuit 2 is used as shown in FIG. Thus, a luminance signal not including a synchronization signal is extracted.
Then, as shown in FIG. 5A, the extracted luminance signal is input to a first integration circuit (not shown) having a long time constant, and the signal from which the short-time fluctuation is removed and Become.
Further, the signal after passing through the integrating circuit is averaged for each section based on the Y count value of the counter circuit 3, and the average value is compared with the average value before one count to compare the luminance signal. By capturing the change of the lowest value portion and repeatedly executing the operation every time the Y count value is updated, the luminance signal level is averagely the lowest in the vertical direction among the luminance signals in the frame, and the change A portion having a small amount is detected and the information is output as a detection signal Sv. Since the detection is performed in units of frames, the calculation data for obtaining the minimum value is reset by the vertical synchronization signal of the first field.
Further, in the region detection circuit 4, as shown in FIG. 5B, the luminance signal after the synchronization signal is removed is input to a second integration circuit (not shown), and the X count value of the counter circuit 3 is input. Based on the above, each section is averaged, and a portion where the level of the luminance signal is the lowest and the change is small is detected in each horizontal synchronization period (1H), and the information is output as a detection signal Sh.
Therefore, by combining the two detection signals Sv and Sh, as shown in FIG. 6, it is possible to detect one block having an average low luminance level and a small amount of change within 8 × 8 blocks × 2 fields. become.

Next, the position calculation circuit 5 uses the position update timing signal of the timing generation circuit 2, the X count value and the Y count value of the counter circuit 3, and the detection signals Sv and Sh of the area detection circuit 4 as auxiliary signals described later. The additional position information and the additional timing signal are output.
That is, when the position update timing signal is received from the timing generation circuit 2, the position information in the screen of the block specified by the detection signals Sv and Sh output from the area detection circuit 4 is obtained, and the additional position information of the auxiliary signal is obtained. And a signal for giving a timing for adding an auxiliary signal to the block.
The output cycle of the position update timing signal can be set by a preset value by the update time setting switch 26 in the timing generation circuit 2, and the output cycle of the position calculation circuit 5 is every frame, every 1 to 10 seconds, or the like. Can be set arbitrarily.

The luminance signal separated by the Y-C separation circuit 1 is input to the VBID addition circuit 6, and the VBID addition circuit 6 receives copyright management information (CGMS-A; Copy Generation Management System Analog) input in advance. Is added to a predetermined position within the blanking period of the luminance signal using the X count value and Y count value of the counter circuit 3.
Here, the copyright management information is recorded in 2 bits. “11” indicates “copy prohibited”, “01” indicates “one generation copy and no more copies”, “10” indicates “1”. "Copyable only once" and "00" indicate "Copyable".
The auxiliary position information of the auxiliary signal is input from the position calculation circuit 5 to the VBID addition circuit 6, and the additional position information is also input to the VBID addition circuit 6 within the blanking period of the video signal as in the copyright management information. Is added to a predetermined position.
Specifically, as shown in FIG. 7, the copyright management information and the auxiliary signal additional position information are recorded in the AGC reference level detection section in the blanking period, and the auxiliary signal additional position information is As shown in FIG. 8, the presence or absence of the auxiliary signal is recorded in the first 4 bits, and the Y count value and the X count value are recorded in the next 16 bits.
These signals are recorded by a method according to the recording of the pseudo SYNC pulse according to Patent Document 1 of the prior art.

The luminance signal that has undergone the processing in the VBID addition circuit 6 is then input to the auxiliary signal addition circuit 7.
The auxiliary signal adding circuit 7 adds the auxiliary signal stored in advance in the additional pattern ROM 7a to the corresponding block in the screen at the timing indicated by the additional timing signal.
For example, as shown in FIG. 6, when the lowest luminance block in the screen detected by the area detection circuit 4 is (7, 7), as shown in FIG. 9, a character (character, figure, symbol) is displayed. Etc.), a geometric pattern (checkered pattern, etc.), or a luminance signal for one block composed of a combination thereof, is added as an auxiliary signal to the luminance signal of the block (7, 7).
Further, as shown in FIG. 9 and FIG. 10, the auxiliary signal is detected by the area detection circuit 4 so that the luminance level of the portion corresponding to the ground color in the block prevents normal viewing of the content. The maximum luminance level signal far exceeds the average luminance level.
In the case of the circuit configuration in FIG. 1, the auxiliary timing additional signal is detected based on the luminance signal one frame before, and the position information is delayed by one frame in terms of timing. However, in the case of a moving image, since the correlation between frames is generally very high, the effect is hardly affected.

In this way, the luminance signal after the copyright management information, the additional position information of the auxiliary signal, and the auxiliary signal are added is output to the Y-C combining circuit 8, and the Y-C combining circuit 8 outputs the Y-C. The separation circuit 1 separates and combines with the color signal delayed by one frame period by the delay circuit 9, and is finally output as a video signal.
Incidentally, since the position of the lowest luminance block in the screen detected by the area detection circuit 4 is naturally moved according to the image content of the video signal (the temporal change in luminance of each block), the auxiliary signal additional position is set. Move accordingly.
In other words, a video signal is output in such a display state that the image block of the auxiliary signal shown in FIG. 9 moves in the frame image.
Then, the image block cannot be removed unless it is detected by a copyright management information detection / processing device corresponding to the copyright management information adding device of this embodiment, and as a result, an illegal copy of the video content is copied. It can be effectively prevented.

This embodiment relates to the same information detection / processing apparatus corresponding to the copyright management information adding apparatus of the first embodiment, and its block circuit diagram is shown in FIG.
First, in the figure, the video signal is input to the Y-C separation circuit 51. The basic functions of the Y-C separation circuit 51, the timing generation circuit 52, and the counter circuit 53 are those circuits 1 and 1 in the first embodiment. 2 and 3, and a description of these functions is omitted here.
In the first embodiment, the timing generation circuit 2 outputs a position update timing signal, but this signal is not necessary in this detection / processing device. The luminance extraction gate signal, the vertical synchronization signal, the horizontal synchronization signal, Only the reference clock is output.

The VBID separation storage circuit 54 uses the count values of the counter circuit 53 to obtain the copyright management information (CGMS-A) added on the copyright management information addition device side and the additional position information of the auxiliary signal as a luminance signal. Are extracted from the blanking period, and the information is decoded and the data is temporarily stored in the built-in memory.
That is, since each information is added to a predetermined position in the blanking period as described in FIG. 7 of the first embodiment, each information is stored at each predetermined timing using each count value and the reference clock. The signal can be extracted and decoded.
In the gate circuit 55, the additional position information of the auxiliary signal extracted and decoded by the VBID separation storage circuit 54 is compared with each count value of the counter circuit 53, and the auxiliary signal is recorded in the screen as shown in FIG. A replacement gate signal indicating the block position is output.

Next, the luminance signal separated by the Y-C separation circuit 51 is input to the auxiliary signal replacement circuit 56, and the replacement gate signal of the gate circuit 55 is also input to the auxiliary signal replacement circuit 56.
The auxiliary signal replacement circuit 56 includes a delay circuit 56a (one field or one frame delay) and a video signal band switch. The luminance signal of the image one field before or one frame before is sent to the delay circuit 56a. The auxiliary signal added to the block indicated by the replacement gate signal in the screen of the current image is replaced with the luminance signal of the corresponding block saved in the delay circuit 56a.
In that case, in the moving image, the correlation between the image one field before or one frame before and the current image is extremely high, so even if they differ by one field or one frame, the influence on the original image is very small.

  Then, the luminance signal after being processed by the auxiliary signal replacement circuit 56 is output to the Y-C synthesis circuit 57, where the Y-C separation circuit 51 separates and the delay circuit 59 outputs 1 It is combined with the color signal delayed for the frame period and finally outputted as a video signal.

On the other hand, the luminance signal separated by the Y-C separation circuit 51 is also input to the auxiliary signal detection circuit 59. The auxiliary signal detection circuit 59 receives the replacement gate signal from the gate circuit 55 as shown in FIG. In use, only the signal corresponding to the auxiliary signal is detected from the corresponding block and output to the copyright information determination circuit 60.
Further, as shown in FIG. 14, a pure luminance signal that does not include a synchronization signal is generated by masking other than the luminance signal based on the luminance extraction gate signal obtained from the timing generation circuit 52. After passing through an integration circuit having a constant, it is output to the copyright information determination circuit 60 as a reference value for comparison.
Then, the copyright information determination circuit 60 compares the detection signal with a reference value to confirm whether the auxiliary signal is recorded.
That is, if the auxiliary signal is recorded, as shown in FIG. 15, since the detection signal greatly exceeds the reference value, the recorded fact can be clearly confirmed.

  Next, the copyright information determination circuit 60 uses the copyright management information, the additional position information of the auxiliary signal, and the auxiliary signal to cope with the copyright management and the modification of the management information as shown in FIG. To determine whether the video signal can be recorded and monitor signal output (reproduction).

Hereinafter, the control relating to whether or not recording is possible, which is executed by the copyright information determination circuit 60, will be specifically described.
(1) If the copyright management information is “11” (copy prohibited) or “01” (one generation copy, no more copies allowed), it is possible to make a strict judgment and add an auxiliary signal. Recording is prohibited with or without position information or auxiliary signals.
(2) If the copyright management information is “10” (can be copied only once), it is determined that the signal has not been altered if the additional position information of the auxiliary signal and the auxiliary signal are correctly detected. Then, after changing the copyright management information to “01” (1st generation copy and no more copies allowed), recording is permitted.
However, when the additional position information of the auxiliary signal or the auxiliary signal is not normally detected, the signal is modified, and thus recording is prohibited.
(3) When the copyright management information is “00” (copiable), recording is naturally permitted if the auxiliary signal additional position information and the auxiliary signal are normally detected, but either or When both are not normally detected, recording is prohibited as in (2) above.
(4) If additional position information or an auxiliary signal is detected in spite of the absence of copyright management information, it is clear that a modification has been made to delete the copyright management information. Is forbidden.
However, if neither the copyright management information, the additional position information of the auxiliary signal, or the auxiliary signal is detected, it can be considered that there is no copyright intention display, so recording is permitted.

In the copyright management information detection / processing apparatus of this embodiment, the control of whether or not recording is possible by the copyright information determination circuit 60 and the modification of the auxiliary signal based on the processing in the auxiliary signal replacement circuit 56 are performed. It has the following resistance.
Only when the auxiliary signal has additional position information and the auxiliary signal is correctly detected based on the information, the auxiliary signal is replaced with the luminance signal of the corresponding block saved by the delay circuit 56a, and the auxiliary signal interferes. Can be obtained.
However, if the copyright management information is removed to remove the additional position information of the auxiliary signal, the position of the auxiliary signal cannot be confirmed and the above replacement cannot be performed normally. The display state moves from time to time in the frame image, and viewing is significantly hindered.
In addition, it can be estimated that while trying to check the block of the auxiliary signal on the display screen, trying to modify the signal of the block, in that case, the additional position information of the auxiliary signal remaining within the blanking period is used. Since the signal of the block at the corresponding position is not an auxiliary signal, the auxiliary signal replacement circuit 56 stops the output.
Therefore, viewing is impossible in such a case.

  In other words, when an analog video signal created by the apparatus of the first embodiment is output (reproduced) / recorded by the digital recording / reproducing apparatus as an input signal, the digital recording / reproducing apparatus changes the apparatus of the second embodiment. In the case of the applied regular device, the content can be normally reproduced and viewed, and if permitted by the copyright management information, it can be copied to another recording medium. In any case, in the case of a digital recording / playback device to which the above device is not applied, the block of the auxiliary signal becomes an image that moves in the screen, and the content cannot be normally viewed. Can be effectively prevented.

  In each of the above embodiments, the input analog video signal is described as a composite signal. However, in the case of a component signal, the luminance signal may be selectively extracted and the processed luminance signal may be restored to the original state. Can be applied regardless of whether it is a composite signal or a component signal.

  In addition to copyright management information (CGMS-A), auxiliary signals that interfere with the normal viewing of content and the addition of video content input as analog signals illegally by digital recording / playback devices By recording the position information in the image signal and the blanking period signal, it is possible to incorporate a robust copyright protection system in the digital recording / reproducing apparatus.

1 is a block circuit diagram of an apparatus for assigning copyright management information according to Embodiment 1. FIG. It is a block circuit diagram of a timing generation circuit. It is a figure for demonstrating the division | segmentation area | region division of the screen by a counter circuit. It is a signal timing chart for demonstrating the operation | movement when an area | region detection circuit isolate | separates only a luminance signal from the signal containing a luminance signal and a synchronizing signal. It is a signal timing chart for demonstrating operation | movement when an area | region detection apparatus calculates | requires the minimum part of the average level of the luminance signal which concerns on the vertical and horizontal direction on a screen. It is a figure which shows the relationship between the block from which the average level of a luminance signal becomes the minimum in a screen, and X, Y count value. It is a signal waveform diagram showing a state where copyright management information and auxiliary signal additional position information are recorded at a predetermined position within a blanking period of an analog video signal. It is a bit block diagram of the additional position information of an auxiliary signal. It is a figure which shows the aspect in which an auxiliary signal is added to the block in a screen. It is a signal waveform diagram in one vertical synchronization period and one horizontal synchronization period showing an addition mode of an auxiliary signal. 6 is a block circuit diagram of a copyright management information detection / processing apparatus according to Embodiment 2. FIG. It is a figure which shows the relationship between the replacement gate signal which a gate circuit outputs, and the block position where the auxiliary signal is recorded within the screen. It is a signal timing chart showing an operation when an auxiliary signal detection circuit detects only a signal corresponding to an auxiliary signal from a corresponding block using a replacement gate signal. It is a signal timing chart for demonstrating the detection operation | movement of the reference value for a comparison by an auxiliary signal detection circuit. It is a signal timing chart for demonstrating the confirmation operation | movement of the presence or absence of an auxiliary signal by a copyright information determination circuit. It is a table | surface which shows the recording control operation | movement by a copyright information determination circuit, the processing content in an auxiliary signal substitution circuit, etc. FIG. 10 is a signal waveform diagram for explaining the analog video signal copy prevention method disclosed in Patent Document 1; FIG. 10 is a bit configuration diagram of a VBID which is a premise regarding a method of superimposing copy prevention information on a VBID signal disclosed in Patent Document 2.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,51 ... Y-C separation circuit, 2,52 ... Timing generation circuit, 3,53 ... Counter circuit, 4 ... Area detection circuit, 5 ... Position calculation circuit, 6 ... VBID addition circuit, 7 ... Auxiliary signal addition circuit, 7a ... additional pattern ROM, 8, 57 ... Y-C synthesis circuit, 9 ... delay circuit, 21 ... clamp / level slice circuit, 22 ... vertical / horizontal sync separation circuit, 23 ... PLL circuit, 24 ... gate signal generation circuit, 25 ... Position update timing circuit, 26 ... Update time setting switch, 54 ... VBID separation memory circuit, 55 ... Gate circuit, 56 ... Auxiliary signal replacement circuit, 56a, 58 ... Delay circuit, 59 ... Auxiliary signal detection circuit, 60 ... Work Right information determination circuit.

Claims (2)

In an apparatus for adding copyright management information to an analog video signal,
Signal separating means for separating a luminance signal from an input analog video signal;
A signal dividing means for dividing the luminance signal for one frame or one field separated by the signal separating means into a plurality of blocks in a manner of dividing the screen;
Position information calculating means for detecting a block having the lowest average level of the luminance signal among blocks for one frame or one field divided by the signal dividing means, and obtaining position information of the detected block;
Storage means for storing inputted copyright management information;
Auxiliary signal generating means for generating an auxiliary signal that is a predetermined image signal of the block size including a high luminance signal;
Information addition for adding the copyright management information of the first storage means and the position information of the block obtained by the position information calculation means to each predetermined position within the blanking period of the luminance signal separated by the signal separation means Means,
Signal adding means for adding an auxiliary signal generated by the auxiliary signal generating means to a signal block corresponding to the position information of the block obtained by the position information calculating means in the luminance signal separated by the signal separating means;
The signal after the signal separation means separates the luminance signal from the analog video signal is combined with the luminance signal after processing by the information addition means and the signal addition means in frame synchronization or field synchronization. An apparatus for adding copyright management information, comprising: A copyright management information detection / processing device corresponding to an analog video signal processed by the copyright management information adding device according to claim 1,
Signal separating means for separating a luminance signal from an input analog video signal;
Information detecting means for detecting copyright management information and additional position information of the auxiliary signal from each predetermined position within a blanking period of the luminance signal separated by the signal separating means;
An auxiliary signal detecting means for detecting an auxiliary signal from the corresponding block of the luminance signal based on the additional position information of the auxiliary signal detected by the information detecting means;
Based on copy permission information indicated by the copyright management information detected by the information detection means, whether or not each information is detected by the information detection means and the auxiliary signal detection means, and the state of the auxiliary signal detected by the auxiliary signal detection means Determining means for determining permission / non-permission of recording of the input analog video signal;
About the luminance signal separated by the signal separation unit, a signal holding unit that always holds the luminance signal one frame before or one field before;
When the determination unit determines to permit recording, the signal block corresponding to the additional position information of the auxiliary signal in the separated luminance signal is replaced with a corresponding signal block held by the signal holding unit. Auxiliary signal replacement means;
Signal synthesis in which the signal after the signal separation means separates the luminance signal from the analog video signal is combined with the luminance signal after the processing by the auxiliary signal replacement means is performed in frame synchronization or field synchronization. An apparatus for detecting and processing copyright management information, characterized by comprising:

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