CA2234971A1 - Method and apparatus for removing or defeating effects of copy protection signals from a video signal - Google Patents

Method and apparatus for removing or defeating effects of copy protection signals from a video signal

Info

Publication number
CA2234971A1
CA2234971A1 CA002234971A CA2234971A CA2234971A1 CA 2234971 A1 CA2234971 A1 CA 2234971A1 CA 002234971 A CA002234971 A CA 002234971A CA 2234971 A CA2234971 A CA 2234971A CA 2234971 A1 CA2234971 A1 CA 2234971A1
Authority
CA
Canada
Prior art keywords
video signal
copy protection
video
portions
signals
Prior art date
Legal status (The legal status 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 status listed.)
Granted
Application number
CA002234971A
Other languages
French (fr)
Other versions
CA2234971C (en
Inventor
Ronald Quan
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Rovi Corp
Original Assignee
Individual
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 Individual filed Critical Individual
Publication of CA2234971A1 publication Critical patent/CA2234971A1/en
Application granted granted Critical
Publication of CA2234971C publication Critical patent/CA2234971C/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N7/00—Television systems
    • H04N7/16—Analogue secrecy systems; Analogue subscription systems
    • H04N7/167—Systems rendering the television signal unintelligible and subsequently intelligible
    • H04N7/171—Systems operating in the amplitude domain of the television signal
    • H04N7/1713—Systems operating in the amplitude domain of the television signal by modifying synchronisation signals
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03K—PULSE TECHNIQUE
    • H03K19/00—Logic circuits, i.e. having at least two inputs acting on one output; Inverting circuits
    • H03K19/02—Logic circuits, i.e. having at least two inputs acting on one output; Inverting circuits using specified components
    • H03K19/173—Logic circuits, i.e. having at least two inputs acting on one output; Inverting circuits using specified components using elementary logic circuits as components
    • H03K19/1733—Controllable logic circuits
    • H03K19/1737—Controllable logic circuits using multiplexers
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03K—PULSE TECHNIQUE
    • H03K19/00—Logic circuits, i.e. having at least two inputs acting on one output; Inverting circuits
    • H03K19/20—Logic circuits, i.e. having at least two inputs acting on one output; Inverting circuits characterised by logic function, e.g. AND, OR, NOR, NOT circuits
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03K—PULSE TECHNIQUE
    • H03K21/00—Details of pulse counters or frequency dividers
    • H03K21/38—Starting, stopping or resetting the counter
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03M—CODING; DECODING; CODE CONVERSION IN GENERAL
    • H03M1/00—Analogue/digital conversion; Digital/analogue conversion
    • H03M1/66—Digital/analogue converters
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N5/00—Details of television systems
    • H04N5/14—Picture signal circuitry for video frequency region
    • H04N5/20—Circuitry for controlling amplitude response
    • 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
    • H04N7/00—Television systems
    • H04N7/08—Systems for the simultaneous or sequential transmission of more than one television signal, e.g. additional information signals, the signals occupying wholly or partially the same frequency band, e.g. by time division
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N7/00—Television systems
    • H04N7/08—Systems for the simultaneous or sequential transmission of more than one television signal, e.g. additional information signals, the signals occupying wholly or partially the same frequency band, e.g. by time division
    • H04N7/087—Systems for the simultaneous or sequential transmission of more than one television signal, e.g. additional information signals, the signals occupying wholly or partially the same frequency band, e.g. by time division with signal insertion during the vertical blanking interval only
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N7/00—Television systems
    • H04N7/08—Systems for the simultaneous or sequential transmission of more than one television signal, e.g. additional information signals, the signals occupying wholly or partially the same frequency band, e.g. by time division
    • H04N7/087—Systems for the simultaneous or sequential transmission of more than one television signal, e.g. additional information signals, the signals occupying wholly or partially the same frequency band, e.g. by time division with signal insertion during the vertical blanking interval only
    • H04N7/088—Systems for the simultaneous or sequential transmission of more than one television signal, e.g. additional information signals, the signals occupying wholly or partially the same frequency band, e.g. by time division with signal insertion during the vertical blanking interval only the inserted signal being digital
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N7/00—Television systems
    • H04N7/16—Analogue secrecy systems; Analogue subscription systems
    • H04N7/167—Systems rendering the television signal unintelligible and subsequently intelligible
    • H04N7/169—Systems operating in the time domain of the television signal
    • H04N7/1693—Systems operating in the time domain of the television signal by displacing synchronisation signals relative to active picture signals or vice versa
    • 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
    • H04N5/91—Television signal processing therefor
    • H04N5/913—Television signal processing therefor for scrambling ; for copy protection
    • H04N2005/91357—Television signal processing therefor for scrambling ; for copy protection by modifying the video signal
    • 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
    • H04N2005/91357—Television signal processing therefor for scrambling ; for copy protection by modifying the video signal
    • H04N2005/91371—Television signal processing therefor for scrambling ; for copy protection by modifying the video signal the video color burst signal being modified

Abstract

In a known copy protection process for preventing recording of video signals, pseudo sync and AGC pulses (Fig. 2) are present on predetermined lines within the blanking intervals of the video signal so that any subsequent video tape recording of the video signal shows a picture of very low entertainment quality. This copy protection process is defeated first by determining the location of the video lines containing the copy protection using the color burst signal or chroma in the horizontal blanking interval to determine online detection (Fig. 4). Then some or all of the lines including copy protection signals are modified so as to render the overall video signal recordable. The modification is accomplished in a number of ways, including gain shifting portions of the video signal, level shifting portions of the video signal, bandwidth limiting certain portions of the video signal or replacing certain portions of the video signal with other video elements (Fig. 5).
CA002234971A 1995-10-17 1996-10-17 Method and apparatus for removing or defeating effects of copy protection signals from a video signal Expired - Lifetime CA2234971C (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
US568195P 1995-10-17 1995-10-17
US60/005,681 1995-10-17
PCT/US1996/016783 WO1997015142A1 (en) 1995-10-17 1996-10-17 Method and apparatus for removing or defeating effects of copy protection signals from a video signal

Publications (2)

Publication Number Publication Date
CA2234971A1 true CA2234971A1 (en) 1997-04-24
CA2234971C CA2234971C (en) 2001-08-07

Family

ID=21717156

Family Applications (2)

Application Number Title Priority Date Filing Date
CA002234971A Expired - Lifetime CA2234971C (en) 1995-10-17 1996-10-17 Method and apparatus for removing or defeating effects of copy protection signals from a video signal
CA002234972A Expired - Lifetime CA2234972C (en) 1995-10-17 1996-10-17 Digitally removing video copy protection pulses

Family Applications After (1)

Application Number Title Priority Date Filing Date
CA002234972A Expired - Lifetime CA2234972C (en) 1995-10-17 1996-10-17 Digitally removing video copy protection pulses

Country Status (12)

Country Link
US (4) US6002830A (en)
EP (4) EP1646234A3 (en)
JP (2) JP4450434B2 (en)
KR (2) KR100474124B1 (en)
CN (2) CN1164113C (en)
AT (2) ATE477678T1 (en)
AU (3) AU700093B2 (en)
CA (2) CA2234971C (en)
DE (2) DE69635555T2 (en)
HK (1) HK1015100A1 (en)
NZ (2) NZ323128A (en)
WO (2) WO1997015142A1 (en)

Families Citing this family (56)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6516132B1 (en) * 1995-05-09 2003-02-04 Macrovision Corp Method and apparatus for improving the effects of color burst modifications to a video signal
JP3624226B2 (en) * 1995-05-09 2005-03-02 マクロビジョン コーポレーション Method and apparatus for negating the effects of color burst changes on video signals
CN1164113C (en) * 1995-10-17 2004-08-25 麦克罗维西恩公司 Digitally removing video copy protection pulses
ES2150243T3 (en) * 1996-04-01 2000-11-16 Macrovision Corp A METHOD AND APPARATUS TO PROVIDE PROTECTION AGAINST COPIES OF SIGNAL MATERIAL TRANSMITTED THROUGH DIGITAL DELIVERY NETWORKS TO A CONSUMER DECODER TERMINAL.
US7395545B2 (en) * 1997-03-31 2008-07-01 Macrovision Corporation Method and apparatus for providing copy protection using a transmittal mode command
JP3891230B2 (en) * 1997-05-29 2007-03-14 ソニー株式会社 Additional information superimposing apparatus and additional information superimposing method
US6295360B1 (en) 1997-06-30 2001-09-25 Macrovision Corporation Method and apparatus to defeat composite video signal protection
US6404889B1 (en) * 1997-06-30 2002-06-11 Macrovision Corporation Protection of a component video signal
JP4003096B2 (en) * 1997-09-01 2007-11-07 ソニー株式会社 Method and apparatus for superimposing additional information on video signal
US6141488A (en) * 1997-09-05 2000-10-31 United Video Properties, Inc. Program guide system for recording television programs
US6459795B1 (en) * 1998-02-26 2002-10-01 Macrovision Corporation Method and apparatus for enhancing the scrambling of a TV signal via erroneous clamp signals
US6600873B1 (en) * 1998-03-20 2003-07-29 Macrovision Corporation Method and apparatus for detecting modified color burst signals to prevent the copying of a video program
US6137952A (en) * 1998-04-02 2000-10-24 Hewlett-Packard Company Apparatus and method for degrading the quality of unauthorized copies of color images and video sequences
WO1999060748A1 (en) * 1998-05-20 1999-11-25 Recording Industry Association Of America Data disc modulation for minimizing pirating
US6345099B1 (en) * 1998-05-22 2002-02-05 S3 Incorporated System and method for copy protecting computer graphics
US6836549B1 (en) 1998-09-02 2004-12-28 Macrovision Corporation Method and apparatus for synthesizing and reducing the effects of video copy protection signals
EP1480456A1 (en) * 1998-09-02 2004-11-24 Macrovision Corporation Method and apparatus to reduce the effects of video copy protection signals
CN1809149B (en) * 1998-09-02 2010-09-08 麦克罗维西恩公司 Method and apparatus to synthesize and defeat video copy protection signals
WO2000028664A2 (en) 1998-11-12 2000-05-18 Broadcom Corporation Fully integrated tuner architecture
US7634089B1 (en) 1999-10-29 2009-12-15 Sarnoff Corporation Cinema anti-piracy measures
US7324646B1 (en) 1999-10-29 2008-01-29 Sarnoff Corporation Method and apparatus for film anti-piracy
FR2808957B1 (en) * 2000-05-11 2003-10-24 Dominique Patrick Bryszkowski ECONOMIC ELECTRONIC DEVICES DESACHIVING OR ATTENUATING THE EFFECTS OF ANTI-COPY SIGNALS INSERTED IN A VIDEO SIGNAL AND AUTHORIZING COPY
US6842522B1 (en) * 2000-06-01 2005-01-11 Macrovision Corporation Secure digital video disk and player
US6638593B2 (en) 2000-06-30 2003-10-28 Verification Technologies, Inc. Copy-protected optical media and method of manufacture thereof
US20050063256A1 (en) * 2000-06-30 2005-03-24 Selinfreund Richard H. Data storage in optical discs
AU2001259033A1 (en) 2000-06-30 2002-01-14 Verification Technologies, Inc. Copy-protected optical media and method of manufacture thereof
US7124944B2 (en) * 2000-06-30 2006-10-24 Verification Technologies, Inc. Product packaging including digital data
US7660415B2 (en) 2000-08-03 2010-02-09 Selinfreund Richard H Method and apparatus for controlling access to storage media
US7050698B1 (en) * 2000-08-15 2006-05-23 Macrovision Corporation Method and apparatus for synthesizing or modifying a copy protection signal using a lowered signal level portion
US7110042B1 (en) * 2001-11-07 2006-09-19 Pixelworks, Inc. Synchronization signal decoder and associated method
US7599604B2 (en) * 2001-12-14 2009-10-06 Thomson Licensing Asynchronous copy protection detector
US20050084645A1 (en) * 2002-02-07 2005-04-21 Selinfreund Richard H. Method and system for optical disc copy-protection
JP3789838B2 (en) * 2002-03-26 2006-06-28 三洋電機株式会社 Display device
JP2004064369A (en) * 2002-07-29 2004-02-26 Toshiba Corp Apparatus and method for detecting signal for preventing reproduction
US7398008B2 (en) * 2002-09-19 2008-07-08 Hewlett-Packard Development Company, L.P. Copy protection for analog video signals from computing devices
EP1547054A4 (en) * 2002-09-26 2010-01-20 Verification Technologies Inc Authentication of items using transient optical state change materials
US7376337B2 (en) * 2002-09-30 2008-05-20 Matsushita Electric Industrial Co., Ltd. Video signal recording apparatus for copyrighted works
US20060203700A1 (en) * 2003-02-06 2006-09-14 Verification Technologies, Inc. Method and system for optical disk copy-protection
US7116374B2 (en) * 2003-08-26 2006-10-03 Koplar Interactive Systems International, L.L.C. Method and system for enhanced modulation of video signals
US7865057B2 (en) * 2003-10-07 2011-01-04 Rovi Solutions Corporation Method and apparatus for conveying rights across an analog video interface
KR20050070953A (en) 2003-12-31 2005-07-07 삼성전자주식회사 Analogue/digital signal processing apparatus for outputting the analogue input signal without eliminating the copy protection signal included therein and method thereof
US7664175B1 (en) 2004-06-16 2010-02-16 Koplar Interactive Systems International, L.L.C. Mark-based content modulation and detection
US20060023598A1 (en) * 2004-07-30 2006-02-02 Babinski James P Method and apparatus for protecting against copying of content recorded on optical recording media
DE102004046618A1 (en) * 2004-09-25 2006-03-30 Robert Bosch Gmbh Circuit arrangement for analog / digital conversion
US7784103B2 (en) * 2004-10-19 2010-08-24 Rovi Solutions Corporation Method and apparatus for storing copy protection information separately from protected content
US7907727B2 (en) * 2004-10-19 2011-03-15 Rovi Solutions Corporation System and method for allowing copying or distribution of a copy protected signal
CA2585732C (en) * 2004-10-28 2012-03-20 Macrovision Corporation Content management for high definition television
US7792293B2 (en) * 2005-05-06 2010-09-07 Rovi Solutions Corporation Method and apparatus for modifying a subsequently generated control command in a content control system
US20080100597A1 (en) * 2006-10-25 2008-05-01 Macrovision Corporation Method and apparatus to improve playability in overscan areas of a TV display
US20080309816A1 (en) * 2007-06-15 2008-12-18 Macrovision Corporation Television content control system and method with cross-platform capability
US8798133B2 (en) * 2007-11-29 2014-08-05 Koplar Interactive Systems International L.L.C. Dual channel encoding and detection
US20090317057A1 (en) * 2008-06-24 2009-12-24 Hua Wu Apparatus and method for selectively outputting hd/sd signals as high definition video according to copy protection
US8280049B2 (en) * 2008-08-27 2012-10-02 Rovi Solutions Corporation Method and apparatus for synthesizing copy protection for reducing/defeating the effectiveness or capability of a circumvention device
TWI357186B (en) * 2008-10-17 2012-01-21 Wistron Corp Electronic card connector, electronic decoding dev
US8374490B2 (en) * 2010-02-24 2013-02-12 Rovi Technologies Corporation Method and apparatus for receiving metadata, EPG, or IPG signals in an integrated circuit for control purposes
US10945051B1 (en) 2020-04-06 2021-03-09 Bank Of America Corporation System and method for intentionally distorting digital media to reduce the accuracy of generative machine learning algorithms

Family Cites Families (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4336554A (en) * 1980-06-23 1982-06-22 Clarion Co., Ltd. Code signal blanking apparatus
US4571615A (en) * 1983-06-10 1986-02-18 General Instrument Corporation Timing generator for sync suppressed television signals
US4577216A (en) * 1983-11-14 1986-03-18 Macrovision Method and apparatus for modifying the color burst to prohibit videotape recording
US4819098A (en) * 1983-11-23 1989-04-04 Macrovision Corporation Method and apparatus for clustering modifications made to a video signal to inhibit the making of acceptable videotape recordings
US5194965A (en) * 1983-11-23 1993-03-16 Macrovision Corporation Method and apparatus for disabling anti-copy protection system in video signals
US4742543A (en) * 1983-12-22 1988-05-03 Frederiksen Jeffrey E Video transmission system
US4626890A (en) * 1984-07-03 1986-12-02 Macrovision Method and apparatus for removing phase modulation from the color burst
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
US4695901A (en) * 1986-03-04 1987-09-22 Macrovision Method and apparatus for removing pseudo-sync and/or agc pulses from a video signal
US4907093A (en) * 1986-08-11 1990-03-06 Macrovision Corporation Method and apparatus for preventing the copying of a video program
US4937679A (en) * 1986-08-11 1990-06-26 Macrovision Dual deck video recording apparatus having enhanced copy protection and method for providing enhanced copy protection to such a recording apparatus
EP0301504B1 (en) * 1987-07-29 1996-09-25 Scitec Corporation Method of copy protecting a pre-recorded videotape
US5058157A (en) * 1989-09-06 1991-10-15 Macrovision Corporation Method and apparatus for encrypting and decrypting time domain signals
US5157510A (en) * 1990-12-20 1992-10-20 Macrovision Corporation Method and apparatus for disabling anti-copy protection system in video signals using pulse narrowing
US5315448A (en) * 1993-03-18 1994-05-24 Macrovision Corporation Copy protection for hybrid digital video tape recording and unprotected source material
US5583936A (en) * 1993-05-17 1996-12-10 Macrovision Corporation Video copy protection process enhancement to introduce horizontal and vertical picture distortions
JP3624226B2 (en) * 1995-05-09 2005-03-02 マクロビジョン コーポレーション Method and apparatus for negating the effects of color burst changes on video signals
CN1164113C (en) * 1995-10-17 2004-08-25 麦克罗维西恩公司 Digitally removing video copy protection pulses
JP3694981B2 (en) * 1996-04-18 2005-09-14 ソニー株式会社 Video signal processing apparatus and video signal processing method
US6058191A (en) * 1997-02-04 2000-05-02 Macrovision Corp Method and apparatus for modifying the envelope of a RF carrier signal to remove copy protection signals therefrom

Also Published As

Publication number Publication date
CN1200219A (en) 1998-11-25
US6421497B1 (en) 2002-07-16
KR19990064292A (en) 1999-07-26
AU7718396A (en) 1997-05-15
JPH11513861A (en) 1999-11-24
ATE312475T1 (en) 2005-12-15
EP0856224A4 (en) 1998-11-25
JP4355819B2 (en) 2009-11-04
AU7458096A (en) 1997-05-07
US6002830A (en) 1999-12-14
DE69638231D1 (en) 2010-09-23
DE69635555D1 (en) 2006-01-12
US6173109B1 (en) 2001-01-09
CN1118192C (en) 2003-08-13
AU715473B2 (en) 2000-02-03
CA2234971C (en) 2001-08-07
DE69635555T2 (en) 2006-07-13
JPH11513872A (en) 1999-11-24
KR100489145B1 (en) 2005-09-14
EP1416730A2 (en) 2004-05-06
JP4450434B2 (en) 2010-04-14
AU700266B2 (en) 1998-12-24
KR19990064352A (en) 1999-07-26
EP1646234A2 (en) 2006-04-12
CN1200222A (en) 1998-11-25
CA2234972C (en) 2001-07-31
EP0890261A4 (en) 1999-01-13
KR100474124B1 (en) 2005-07-18
HK1015100A1 (en) 1999-10-08
EP0890261A1 (en) 1999-01-13
EP0856224A1 (en) 1998-08-05
NZ321300A (en) 1998-08-26
EP0890261B1 (en) 2010-08-11
US5953417A (en) 1999-09-14
AU1428799A (en) 1999-04-01
EP1646234A3 (en) 2010-11-24
CA2234972A1 (en) 1997-05-01
NZ323128A (en) 1998-09-24
WO1997015142A1 (en) 1997-04-24
EP0856224B1 (en) 2005-12-07
ATE477678T1 (en) 2010-08-15
EP1416730A3 (en) 2010-07-07
AU700093B2 (en) 1998-12-24
WO1997016022A1 (en) 1997-05-01
CN1164113C (en) 2004-08-25

Similar Documents

Publication Publication Date Title
CA2234971A1 (en) Method and apparatus for removing or defeating effects of copy protection signals from a video signal
MY118026A (en) Method and apparatus for defeating effects of color burst modifications to a video signal
ATE48732T1 (en) METHOD AND APPARATUS FOR PROCESSING A VIDEO SIGNAL TO PREVENT THE PRODUCTION OF ACCEPTABLE VIDEO TAPE RECORDING THEREOF.
WO1997015142A9 (en) Method and apparatus for removing or defeating effects of copy protection signals from a video signal
US6600873B1 (en) Method and apparatus for detecting modified color burst signals to prevent the copying of a video program
JPH11503282A (en) Method and apparatus for processing video signals
GB2396767A (en) Inserting positive-going pulses to back porch of a video signal for copy protection
JP3141032B2 (en) A method for adaptively controlling the presence or absence of a copy protection signal
AU720847B2 (en) Method and apparatus for detecting modified color burst signals to prevent the copying of a video program
ATE462274T1 (en) METHOD AND APPARATUS FOR MODIFYING A VIDEO SIGNAL TO PREVENT THE PRODUCTION OF ACCEPTABLE VIDEO TAPES
MX9708327A (en) Method and apparatus for defeating effects of color burst modifications to a video signal.

Legal Events

Date Code Title Description
EEER Examination request
MKEX Expiry

Effective date: 20161017

MKEX Expiry

Effective date: 20161017