WO2003065716A2 - Protection contre la copie destinee a des signaux video - Google Patents

Protection contre la copie destinee a des signaux video Download PDF

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Publication number
WO2003065716A2
WO2003065716A2 PCT/GB2003/000450 GB0300450W WO03065716A2 WO 2003065716 A2 WO2003065716 A2 WO 2003065716A2 GB 0300450 W GB0300450 W GB 0300450W WO 03065716 A2 WO03065716 A2 WO 03065716A2
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WO
WIPO (PCT)
Prior art keywords
video signal
pulse
modified
signal
modifying
Prior art date
Application number
PCT/GB2003/000450
Other languages
English (en)
Other versions
WO2003065716A3 (fr
Inventor
Arie Wijnen
Baolin Tan
Original Assignee
Dwight Cavendish Systems Limited
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Dwight Cavendish Systems Limited filed Critical Dwight Cavendish Systems Limited
Publication of WO2003065716A2 publication Critical patent/WO2003065716A2/fr
Publication of WO2003065716A3 publication Critical patent/WO2003065716A3/fr
Priority to US10/909,918 priority Critical patent/US20050111661A1/en
Priority to US12/463,209 priority patent/US8542980B2/en
Priority to US14/033,235 priority patent/US9269392B2/en

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Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N5/00—Details of television systems
    • H04N5/76—Television signal recording
    • H04N5/91—Television signal processing therefor
    • H04N5/913—Television signal processing therefor for scrambling ; for copy protection
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N5/00—Details of television systems
    • H04N5/76—Television signal recording
    • H04N5/91—Television signal processing therefor
    • H04N5/913—Television signal processing therefor for scrambling ; for copy protection
    • H04N2005/91307—Television signal processing therefor for scrambling ; for copy protection by adding a copy protection signal to the video signal
    • H04N2005/91314—Television signal processing therefor for scrambling ; for copy protection by adding a copy protection signal to the video signal the copy protection signal being a pulse signal inserted in blanking intervals of the video signal, e.g. pseudo-AGC pulses, pseudo-sync pulses
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N5/00—Details of television systems
    • H04N5/76—Television signal recording
    • H04N5/765—Interface circuits between an apparatus for recording and another apparatus
    • H04N5/775—Interface circuits between an apparatus for recording and another apparatus between a recording apparatus and a television receiver
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N5/00—Details of television systems
    • H04N5/76—Television signal recording
    • H04N5/765—Interface circuits between an apparatus for recording and another apparatus
    • H04N5/775—Interface circuits between an apparatus for recording and another apparatus between a recording apparatus and a television receiver
    • H04N5/7755—Interface circuits between an apparatus for recording and another apparatus between a recording apparatus and a television receiver the recorder being connected to, or coupled with, the antenna of the television receiver

Definitions

  • the present application relates to a method and an apparatus for modifying a raster-scanned video signal such that the modified video signal will still be viewable on a display device, such as a television screen, but that following recording of the modified video signal, playback of the recorded modified signal will be adversely affected.
  • the present application provides a way of preventing unauthorised copying of an original video signal, and may be used, in particular, to deter copying onto tape of Pay-Per-View video signals, and video-to-video (tape-to- tape) copying.
  • Video piracy is a significant problem for broadcasters and distributors of video signals, since the unauthorised copying and distribution of video recordings by pirates can impact drastically on the revenue generated by a broadcaster or distributor through legitimate sales. It is therefore desirable to prevent video pirates from making unauthorised copies of video signals.
  • the unauthorised recording of the video signal is made less enjoyable to watch by the interaction of the original signal to which the protection has been applied with the electronic components in either the video cassette recorder or the television receiver itself.
  • making an unauthorised copy of the video signal too dark to be viewed satisfactorily may be achieved by adding to the original video signal a pulse which is significantly larger than that part of the signal which carries the picture information.
  • the position at which the pulse is added depends on the way in which the circuits in the television receiver or video recorder process the signal.
  • the modified signal is processed by the automatic gain control circuits of a video cassette recorder, the amplitude of the signal is perceived as being that of the added pulse and not that of the portion of the signal carrying the useful information.
  • the video cassette recorder or television receiver amplifies the received signal by a smaller factor than if the pulse was not present. As a result of this the information-carrying portion of the signal is not therefore amplified enough to be seen satisfactorily when reproduced.
  • Such methods have however a number of drawbacks. Methods which rely on the automatic gain control of the video cassette recorder, such as adding a large pulse to the signal, tend to result in a modified signal that cannot itself be viewed on a television through the video channel regardless of whether the signal is being or has been recorded.
  • a further technique relies on inserting a pulse into the color burst information portion of the signal section of the signal, such that automatic gain control circuits that rely on the average dc level of the color burst to determine the necessary amplification of the signal, make such amplification too small.
  • An opposing pulse signal having a magnitude sufficient to offset the change in dc level of the color burst portion caused by the pulse signal, and optionally a second pulse, are inserted somewhere from the last half of the remainder of the back porch of the signal to the end of the start of the picture information portion.
  • a positive-going pulse is added to the back porch of the raster-scanned video signal such that it is substantially contiguous with the negative-going horizontal synchronisation pulse.
  • the effect of the pulse is again apparent following recording of the video signal by a video cassette recorder.
  • a negative-going pulse 96 may be added after the color burst 92 and a further positive-going pulse 98 at the start of the active line 84.
  • Figure 1 is an illustration of portions of a typical video picture signal
  • Figure 2 is an illustration of an example integrator circuit such as that used to detect vertical synchronisation pulses in television receivers;
  • Figure 3 is an illustration of the voltage output from the example integrator circuit shown in Figure 2, following the receipt of a conventional vertical synchronisation pulse;
  • Figure 4 is an illustration of a modified signal in accordance with a first aspect of the invention.
  • Figures 5a and 5b illustrate a single modified vertical synchronisation pulse of the signal shown in Figure 4 before and after recording
  • Figure 6 is a schematic circuit diagram showing a preferred set-top box incorporating apparatus for producing the signal shown in Figures 4 and 5a;
  • Figure 7a is an illustration of a number of lines of a known unmodified picture signal
  • Figure 7b is an illustration of a modified PAL picture signal according to the second aspect of the invention
  • Figure 7c is an illustration of a modified NTSC signal in accordance with the second embodiment of the invention.
  • Figure 8 is a schematic circuit diagram showing the preferred embodiment of apparatus for generating the signal shown in Figure 7b.
  • Figure 1 shows part of a conventional raster-scanned video signal 2 for a PAL picture signal. Two blanking regions of the signal are shown with a few picture lines on either side. The upper blanking region shown is at the end of an odd field and the lower one is at the end of an even field.
  • the picture signal is comprised of 625 lines 4 containing control information 6, such as synchronisation pulses, which are used to configure the response of the television receiver to the signal and ensure generation of a good quality picture, and usually picture information 8.
  • control information 6 such as synchronisation pulses, which are used to configure the response of the television receiver to the signal and ensure generation of a good quality picture, and usually picture information 8.
  • the line numbers 1-9, 308-320, and 622-625 are shown on the figure.
  • the synchronisation pulses are used to reset the television receiver so that it is ready to display the next line of picture information, following the completion of the previous line (horizontal synchronisation pulses), or following completion of an entire field (vertical synchronisation pulses).
  • each picture information line 5 namely the lines at the left side of the figure, can be seen to comprise picture information 8, shown as a positive going waveform, and a horizontal synchronisation pulse, 10, shown as a negative-going pulse.
  • the vertical blanking region 12 of the signal contains the vertical synchronisation pulses 14 used to control fly-back from the bottom of the television screen to the top once a field or raster of the picture has been displayed.
  • a PAL or NTSC
  • the picture is generated on the screen in two rasters that are interlaced with each other, and it is therefore necessary to have two blanking regions. These are both illustrated for the PAL signal in Figure 1.
  • the first blanking region 12 begins at line 310 of the picture signal and the second blanking region 16 begins at line 623-5.
  • Line 623 of the picture signal therefore contains only a half line of picture information.
  • the television receiver is set up such that this line lies outside of the viewable area of the television screen and, like the blanking section, is therefore not viewed. It will be appreciated by those skilled in the art that the lines of the picture signal are numbered consecutively from 1 to 625, and that the signal between the two blanking regions is therefore continuous.
  • the blanking section itself comprises five negative-going equalisation 18 pulses each of 2.3 ⁇ s width, followed by five negative-going vertical synchronisation pulses 14 each of 27.3 ⁇ s width, followed by a further five equalisation pulses.
  • the equalisation pulses 18 play a similar role to the horizontal synchronisation pulses 10 and need not be discussed further here as their function is well known to those skilled in the art.
  • the dc level 20, namely the voltage from which the line synchronisation pulses extend is called the blanking level. This voltage corresponds to the color black in the picture information.
  • the vertical synchronisation pulses control vertical fly-back between fields.
  • a television receiver detects the presence of the vertical synchronisation pulses using an integrator circuit.
  • a capacitor in the integrator circuit charges, during each of the synchronisation pulses, and discharges during the spaces in between. The positioning and the duration of the vertical synchronisation pulses is such that the capacitor charges beyond a predetermined threshold that would not be reached due to charging from the narrower horizontal synchronisation pulses or equalisation pulses alone.
  • Figures 2 and 3 respectively show an example of an integrator circuit and of the voltage across the capacitor as the synchronisation pulses are received.
  • the integrator circuit 30 shown comprises two input terminals 32 and two output terminals 34.
  • a resistor 36 is connected between first input and first output terminals, to form the first stage of the circuit, and a capacitor 38 is connected, after the resistor, across the output terminals to form the end-stage of the circuit.
  • the voltage across the capacitor increases as shown in Figure 3.
  • the duration of the horizontal synchronisation pulses and equalisation pulses produces only small increases in voltage as shown by peaks 40 and 42 respectively.
  • the vertical synchronisation pulses produce a much greater increase in voltage, as illustrated by peaks 44, such that the capacitor voltage exceeds a predetermined detection threshold 46.
  • the threshold need not be exceeded after the first synchronisation pulse, as shown in Figure 3, but will, in normal operation, be exceeded at least by the time the fifth vertical synchronisation pulse is received.
  • a video signal is modified such that it can be viewed on a television screen in the same way as an unmodified signal, but following recording by a conventional Video Cassette Recorder (VCR), subsequent playback of the recorded signal is unwatchable due to poor picture quality.
  • VCR Video Cassette Recorder
  • the reduction in the picture quality in particular appears as instability in the vertical hold of the picture causing it to jump and jitter on the screen.
  • the synchronisation pulses shown in the top half of Figure 4 have been modulated according to the invention to include a waveform 52 with a much shorter period than that of the vertical synchronisation period and which extends above the blanking level. It has been found that this additional waveform may have a frequency in the range 50kHz to 5MHz, and a minimum voltage level of
  • the presence of the modulation or additional waveform 52 in the modified signal does not have an effect on vertical synchronisation of the picture until it is recorded. This is because the amplitude of the additional waveform is too small before recording to have any significant effect on vertical synchronisation pulse detection. As a result the modified signal may be viewed normally.
  • the modified signal when recorded by a video recorder, the signal is amplified.
  • the magnitude of the part of the signal lying below the blanking signal is 'clamped' or limited such that, even after amplification, the amplitude of the negative-going horizontal and vertical synchronisation pulses remains substantially at the synchronisation pulse level, that is the predetermined voltage required to ensure operation of the respective synchronisation pulse detection circuits.
  • the signal that is above the blanking level is effectively amplified in relation to the negative part of the signal and therefore takes up a larger proportion of the total amplitude of the signal.
  • Figure 5a shows one vertical synchronisation pulse 50 of a signal modified according to the first aspect of the invention to contain an additional waveform 52, before the signal has been recorded.
  • the blanking level 20 is indicated on the figure, as is the zero-crossing point 54, or average value of the signal.
  • the additional waveform is a square wave, as shown, as this is found after amplification to have a greater effect on the zero-crossing point or average value than a substantially sinusoidal waveform for example.
  • the square wave does not necessarily have to have a duty cycle of 50%.
  • the positive amplitude of the signal might typically extend to +250mV.
  • the amplitude of the additional waveform applied to the vertical synchronisation pulse is not sufficient, before recording, to cause instability in the vertical hold of the picture when viewed, either directly on the television or monitor, or indirectly through the video recorder.
  • the part of the additional waveform lying above the blanking signal is amplified in relation to the negative-going synchronisation pulse, which remains clamped at the same amplitude. This is illustrated in Figure 5b, which shows the signal of Figure 5a after being recorded.
  • an initial modulated signal of amplitude +250mV might be amplified to +500mV above the blanking level, while the signal below the blanking level remains clamped at an amplitude of -300mV.
  • the average level of the signal in the region of the field synchronisation pulses is now less negative than before it was recorded.
  • the zero-crossing point or average value of the signal in the region of the vertical synchronisation pulse is raised, and the capacitor does not charge as rapidly towards the predetermined detection threshold.
  • the television receiver cannot therefore detect the field synchronisation pulses as easily, and the resulting recorded picture, when played-back, will jump and jitter and not be enjoyable to watch.
  • the effect of the amplification of the modulation signal in the field synchronisation pulses might be sufficient after just a single recording to result in the television receiver having difficulty detecting the pulses.
  • a front porch 56 is added to the signal before the first modulated vertical synchronisation pulse.
  • the front porch shown has an amplitude of -300mV, i.e. about the same as that of the vertical synchronising pulses, and a width of 10 ⁇ s, though a range of 5 ⁇ s to 15 ⁇ s may be found to be effective, and is found to improve the stability of the un-recorded modified signal when viewed.
  • Certain television receivers have difficulty detecting the vertical synchronisation pulses when they have been modified according to the invention, and as a result jitter during display of the video signal on the television screen can occur even before recording of the signal has occurred.
  • the front porch therefore acts like a single, unmodified vertical synchronisation pulse, and even though its duration is much shorter than typical vertical synchronisation pulses, it has been found just enough to mark the beginning of the blanking signal in which the vertical pulses are contained and aid their detection by such television receivers.
  • the above described techniques for producing an video signal with anti- copy protection have the advantage that the resulting modified signal may be viewed on a television set through the video channel or otherwise, without any disruption to the picture quality. Only when the signal has actually been recorded on a video recorder and is being played-back is the effect on the picture quality realised.
  • This technique has considerable application to pay-per-view broadcasts, in which a broadcaster may, by transmitting a modified picture signal in accordance with the first aspect of the invention, prevent a receiver of the video signals from recording them onto tape. This allows broadcasting companies to broadcast programmes or movies before they are due for release on video, and be sure that any subsequent licensed sales of the programmes or movies on video will be substantially unaffected. As the receiver of the programme cannot record it, the copyright in the programme may be protected.
  • the vertical synchronisation pulses of both PAL and NTSC signals can be modified in the manner described above.
  • FIG. 6 shows a preferred circuit for generating the modified video signal described above.
  • This circuit may be provided as a separate apparatus or, as is more likely, as part of a Pay-Per-
  • the set-top-box 60 shown in Figure 6 has a housing 62 in which input terminal 64 is mounted.
  • An unmodified video signal is received at the input terminal 64 and is passed to an internal synchronisation generator circuit 66 and to video mixer 68.
  • the synchronisation generator circuit 66 strips the picture information from the received video signal and produces a signal containing just the negative-going horizontal and vertical synchronisation pulses and the equalisation pulses.
  • the 'stripped' signal is then passed to a vertical synchronisation pulse detector circuit 70 which detects the vertical synchronisation pulses of the signal and produces, as an output, a signal containing only vertical synchronisation pulses of the required amplitude of -300mV.
  • the output signal is next passed to a square wave generator 72.
  • the square wave generator 72 is triggered by the arrival of each vertical synchronisation pulse to produce a square wave of predetermined frequency for the duration of the vertical synchronisation pulse. This square wave is added to the vertical synchronisation pulse in order to produce the desired modulation.
  • the output of the square wave generator 72 is the combination of the square wave and the vertical synchronisation pulse, which form the modified synchronisation pulse shown in Figure 5a.
  • the modified signal from the square wave generator is then passed to the mixer 68.
  • Mixer 68 combines the signal containing the modified vertical synchronisation pulses from the square wave generator 72 and the original signal received from the input 64, such that the unmodified vertical synchronisation pulses of the original signal are replaced by the modified vertical synchronisation pulses.
  • the horizontal synchronisation pulses and the original picture signal remain effectively unaltered in the mixer.
  • the modified signal is then supplied to an amplifier 74, which amplifies the signal and supplies it to SCART connector 76 or a BNC connector (not shown), or to an RF output terminal 78.
  • the signal can then be viewed on a television or monitor in the usual way, but is rendered unwatchable when recorded by a VCR.
  • Figure 7a shows two adjacent active lines 80 of an unmodified video signal 82.
  • the video signal could be either a PAL or an NTSC signal.
  • Video information 84 is represented by the stepped waveform ascending from the blanking or black level at its bottom to the white peak level at its top. It will be appreciated that this waveform if viewed on a television screen would be seen as color bars.
  • the modified PAL signal includes a first additional pulse 94 with a magnitude that is approximately equal to the peak-white level; typically at a level of 1 to 1 -2 volts.
  • the first additional pulse is substantially contiguous with the horizontal synchronisation pulse. As shown it is situated directly adjacent to the horizontal line synchronisation pulse. In fact the ascending or right-hand edge of the horizontal synchronisation pulse meets the ascending or left-hand edge of the additional pulse smoothly to form a continuous slope, that is to say that there is substantially no space between the edges of the two pulses.
  • AGC Automatic Gain Control circuits of video recorders. These circuits detect horizontal synchronisation pulses and, based on a determination of their amplitude, amplify the video signal such that it is suitable for recording.
  • the amplification provided by the automatic gain control circuit is less than it should be and is insufficient in respect of the rest of the video signal.
  • the recorded signal when played back later on a television receiver, will be too dark to be satisfactorily viewed. Furthermore it may exhibit stability problems, as the horizontal synchronisation pulses and vertical synchronisation pulses have not been amplified enough to be reliably detected by the circuits of the television receiver.
  • the additional pulse be placed contiguous with the horizontal synchronisation pulse.
  • the pulse is not placed in the color burst part of the signal, as this has been found to have an adverse effect on the picture quality while having little or no effect on the automatic gain control circuits.
  • the amplitude of the pulse 94 is approximately white level, as shown, though it may be that an amplitude above 30% of white level will be sufficient in certain circumstances.
  • the duration of the pulse 94 is between 0-5 and 2 ⁇ s and is preferably about 1 ⁇ s. If the duration of the pulse 94 is at the larger end of the range, the horizontal synchronising pulse 86 can be moved slightly earlier (to the left) to provide sufficient space.
  • first pulse 94 has however been found to have a detrimental effect on the payability of the modified signal even before unauthorised recording has occurred. This is because the pulse interferes with the detection stage circuits in the television receiver causing the receiver to display the modified signal as a picture that is darker than it should be.
  • a second, negative going pulse 96 substantially equal in magnitude to a normal horizontal synchronisation pulse, is preferably added to the signal directly after the color burst. This additional negative-going pulse has been found to reverse the ill-effect of first pulse 94 on legitimate playback of the original modified signal.
  • the duration of pulse 96 is in the range 1 to 5 ⁇ s, and is preferably 1 -8 ⁇ s.
  • second pulse 96 makes possible the addition of a third, positive-going pulse 98, located just prior to or at the start of the active video information contained in the signal, and directly next to the negative-going pulse 96.
  • the magnitude of the third pulse is about the same as that of the peak white level, and its duration is in the range 1 to 4 ⁇ s, preferably 2 ⁇ s.
  • the third pulse acts in the same way as first pulse 94, by interfering with the operation of the automatic gain control of the video recorder.
  • the combination of the pulses 96 and 98 again appear like a horizontal synchronisation pulse of larger magnitude than an ordinary synchronisation pulse, and therefore interferes with the automatic gain control circuits of the video recorder to add to the effect caused by the first pulse 94. Without second pulse 96, the presence of third pulse 98 is not enough to cause sufficient instability in the recorded signal.
  • Figure 7c shows a video signal modified according to the invention in a second aspect for use with NTSC television receivers.
  • the signal is similar to that shown in Figure 7b for PAL receivers except that the third pulse 98 is missing and the second pulse is narrower and is located before the color burst rather than after it.
  • the second pulse is given the reference numeral 99 to make it clear that it is different to the second pulse 96 in the case of PAL transmission.
  • the second pulse 99 has a duration in the range 0-5 to 1-2 ⁇ s, and is preferably 0-9 ⁇ s.
  • the horizontal synchronisation pulse 86 can be moved slightly earlier if necessary to provide sufficient space for the second pulse 99.
  • first pulse 94 and second pulse 99 shown in Figure 7c, has been found in the case of NTSC receivers to produce a signal that, once recorded by a video cassette recorder, cannot be viewed on a televison receiver, but that before recording can be viewed at or near to the picture quality intended by the originator of the video signal.
  • second pulse 99 is to undo the darkening effect that the pulse 94 has on playback of the television signal.
  • the preferred apparatus for adding pulses 94, 96 and 98 to the video signal is shown in Figure 8 to which reference should next be made.
  • this apparatus is made use of by video distributors to add the anti-copy protection described above to the video signal. Both however include the first additional pulses 94.
  • the apparatus 100 comprises a housing 102 in which an external input 104 is mounted for receiving an unmodified video signal.
  • the signal is passed from the input to a digital video processor 106 controlled by control software 108.
  • the digital processor analyses the received unmodified signal, and under the control of the software 108, adds pulses to the signal in the manner described above.
  • the digital video processor outputs a signal containing the original signal and the additional pulses to video amplifier 110. This amplifies the signal for output to a video output 112 external to the apparatus.
  • the video output thereby supplies a video signal that has been protected against unauthorised copying according to the second aspect of the invention described above.
  • the video distributor can then record this onto a video cassette using a professional video recorder in which the automatic gain control circuit is turned off.

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  • Engineering & Computer Science (AREA)
  • Multimedia (AREA)
  • Signal Processing (AREA)
  • Television Signal Processing For Recording (AREA)

Abstract

L'invention concerne un appareil et un procédé d'application d'une protection contre la copie à un signal vidéo balayé de façon récurrente. Dans un premier aspect de l'invention, une forme d'onde carrée (52) est ajoutée aux impulsions de synchronisation verticale (50) du signal vidéo. L'effet de la forme d'onde n'est pas apparente jusqu'à ce qu'elle a été enregistrée par un magnétoscope. Ce signal vidéo protégé contre la copie peut alors être vu normalement sur un dispositif d'affichage au niveau, ou presque, de la qualité d'image voulu par l'émetteur du signal vidéo. Cependant, une fois enregistré, la qualité d'image de ce signal vidéo diminue, ce qui rend le signal vidéo désagréable à regarder. Dans un second aspect, une impulsion de sens positif (94) est ajoutée à l'arrière garde du signal vidéo balayé de façon récurrente de sorte qu'elle est sensiblement contiguë à l'impulsion de synchronisation horizontale de sens négatif (86). L'effet de l'impulsion est de nouveau apparent après l'enregistrement du signal vidéo par un magnétoscope. Une impulsion de sens négatif (96) peut être ajoutée après l'impulsion de synchronisation de la couleur (92) et une impulsion de sens positif au début de la ligne active (84).
PCT/GB2003/000450 2002-02-01 2003-02-03 Protection contre la copie destinee a des signaux video WO2003065716A2 (fr)

Priority Applications (3)

Application Number Priority Date Filing Date Title
US10/909,918 US20050111661A1 (en) 2002-02-01 2004-08-02 Anti-copy protection for a video signal
US12/463,209 US8542980B2 (en) 2002-02-01 2009-05-08 Anti-copy protection for a video signal
US14/033,235 US9269392B2 (en) 2002-02-01 2013-09-20 Anti-copy protection for a video signal

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB0202384A GB2387497B (en) 2002-02-01 2002-02-01 Anti-copy protection for a video signal
GB0202384.4 2002-02-01

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US10/909,918 Continuation-In-Part US20050111661A1 (en) 2002-02-01 2004-08-02 Anti-copy protection for a video signal

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WO2003065716A2 true WO2003065716A2 (fr) 2003-08-07
WO2003065716A3 WO2003065716A3 (fr) 2003-12-31

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Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2004110060A1 (fr) * 2003-06-05 2004-12-16 Dwight Cavendish Systems Limited Systemes d'interruption de traitement numerique
US8019201B2 (en) 2002-06-28 2011-09-13 Dcs Copy Protection Limited Method and apparatus for providing a copy-protected video signal
US8160423B2 (en) 2004-10-13 2012-04-17 Dcs Copy Protection Limited Audio copy protection system
US8306403B2 (en) 2010-03-29 2012-11-06 Rovi Technologies Corporation Content control via guide data and/or metadata
US8428258B2 (en) 2007-05-02 2013-04-23 Rovi Technologies Corporation Method and apparatus for providing content control via detection of modifications to a signal

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1996031878A1 (fr) * 1995-04-07 1996-10-10 Trevor Franklin Procede et appareil de traitement d'un signal video
US5737417A (en) * 1995-04-24 1998-04-07 Technicolor Videocassette, Inc. Videotape anti-copying encryption scheme
WO1999000977A1 (fr) * 1997-06-30 1999-01-07 Macrovision Corporation Protection d'un signal video composant

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6052625B2 (ja) * 1976-03-22 1985-11-20 ソニー株式会社 記録済記録媒体及びその作製方法
JPS52114313A (en) * 1976-03-23 1977-09-26 Sony Corp Recorded medium and production method therefor
US4571642A (en) * 1981-08-24 1986-02-18 Hofstein Steven R Method of and apparatus for modifying a video signal to prevent the unauthorized recording and reproduction thereof
US4631603A (en) * 1985-04-17 1986-12-23 Macrovision Method and apparatus for processing a video signal so as to prohibit the making of acceptable video tape recordings thereof
SE458081B (sv) * 1986-09-24 1989-02-20 Conny Togeretz Foerfarande foer att hindra obehoerig kopiering av innehaallet paa videokassettband och anordning foer genomfoerande av foerfarandet
JPS63228888A (ja) * 1987-03-18 1988-09-22 Shinano Kikaku:Kk 記録済ビデオテ−プとその作製方法
US6188832B1 (en) * 1997-05-07 2001-02-13 Microvision Corp Method and apparatus for modifications made to a video signal to inhibit the making of acceptable videotape recordings

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1996031878A1 (fr) * 1995-04-07 1996-10-10 Trevor Franklin Procede et appareil de traitement d'un signal video
US5737417A (en) * 1995-04-24 1998-04-07 Technicolor Videocassette, Inc. Videotape anti-copying encryption scheme
WO1999000977A1 (fr) * 1997-06-30 1999-01-07 Macrovision Corporation Protection d'un signal video composant

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8019201B2 (en) 2002-06-28 2011-09-13 Dcs Copy Protection Limited Method and apparatus for providing a copy-protected video signal
US9264657B2 (en) 2002-06-28 2016-02-16 Dcs Copy Protection Limited Method and apparatus for providing a copy-protected video signal
WO2004110060A1 (fr) * 2003-06-05 2004-12-16 Dwight Cavendish Systems Limited Systemes d'interruption de traitement numerique
US8032006B2 (en) 2003-06-05 2011-10-04 Dcs Copy Protection Limited Digital processing disruption systems
US8837909B2 (en) 2003-06-05 2014-09-16 Dcs Copy Protection Ltd. Digital processing disruption systems
US8160423B2 (en) 2004-10-13 2012-04-17 Dcs Copy Protection Limited Audio copy protection system
US8639092B2 (en) 2004-10-13 2014-01-28 Dcs Copy Protection Limited Audio copy protection system
US8428258B2 (en) 2007-05-02 2013-04-23 Rovi Technologies Corporation Method and apparatus for providing content control via detection of modifications to a signal
US8306403B2 (en) 2010-03-29 2012-11-06 Rovi Technologies Corporation Content control via guide data and/or metadata

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GB2396767B8 (en) 2005-03-15
GB2387497B (en) 2004-12-08
GB0202384D0 (en) 2002-03-20
GB2396767A (en) 2004-06-30
GB2387497A (en) 2003-10-15
WO2003065716A3 (fr) 2003-12-31
GB2396767B (en) 2004-09-08
GB0407606D0 (en) 2004-05-05
GB2396767A8 (en) 2005-03-15

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