Video copy protection process enhancement to introduce horizontal and vertical picture distortions

A method of modifying a video signal subject to copy protection to provide enhanced copy protection where the unmodified copy protection signal causes a reduced amplitude video signal to be recorded on the copy, comprising the steps of:

• providing a waveform of a type for indicating a video retrace;
• and
• substituting the waveform in at least one horizontal line of the copy protected video signal at a location following a synchronization signal of the video signal,
• wherein said waveform increases picture degradation of the copied signal.

A method of modifying a video signal subject to copy protection to provide enhanced copy protection where the unmodified copy protection signal causes a reduced amplitude video signal to be recorded on the copy, comprising the steps of:

• providing a waveform of a type for causing a television set on which the copy is being viewed to retrace horizontally prior to occurrence of the horizontal sync signal;
• and
• substituting the waveform in at least one horizontal line of the copy protection video signal at a location prior to the horizontal sync signal in that line in place of an active video signal otherwise present at that location,
• wherein said waveform increases picture degradation of the copied signal.

An apparatus for modifying a video signal subject to copy protection, to provide enhanced copy protection when a copy of the copy protected signal is played, where the unmodified copy protection causes a reduced amplitude video signal to be recorded on the copy, comprising:

• a blanker for blanking a portion of the active video of the video signal at a location prior to a synchronization signal in the overscan portion of the video signal;
• a pulse generator for generating a predetermined waveform;
• and an adder for adding the generated waveform to the blanked portion of the video signal,
• wherein said enhanced copy protection increases the picture degradation in a copied signal upon playback.

An apparatus for modifying a video signal subject to copy protection to provide enhanced copy protection where the unmodified copy protection signal causes a reduced amplitude video signal to be recorded on the copy, comprising:

• control circuitry for determining a portion of the active video of the copy protected video signal at a location prior to a synchronization signal in an overscan portion of the video signal;
• a pulse generator for generating a predetermined waveform;
• and
• a switch for switching the predetermined waveform into the determined portion of the active video,
• wherein said waveform increases picture degradation of the copied signal.

An apparatus for narrowing line synchronization pulses in a video signal having line synchronization pulses at the beginning of each line and a field synchronization pulse at the beginning of each field, comprising:

• a sync separator for providing indications of line and field synchronization pulses in the video signal;
• line selector circuitry responsive to the provided indications for selecting particular lines in each field of the video signal;
• a one-shot for generating a signal of predetermined length less than that of a line synchronization pulse in response to the provided indications of the line synchronization pulses;
• and
• logic circuitry for adding the generated signals to each of the selected particular lines at a location of the line synchronization pulse in each selected line, thereby reducing a duration of the line synchronization pulse in that line.

An apparatus for defeat of anticopy enhancement pulses present in active video portions of a video signal, the anticopy enhancement pulses being located at the end of at least some video fields and at the end of at least some video lines in the active video portions thereof, comprising:

• a sync level restoration circuit for restoring the horizontal sync pulse tips of the video signal to a predetermined level;
• circuitry for generating control signals of a first predetermined duration at the end of at least some lines of the video signal and of a second predetermined duration at the end of at least some fields of the video signal;
• and
• switch circuitry controlled by the control pulses for switching a particular video signal level into the restored video signal, thereby permitting an acceptable recording to be made thereof.

An apparatus for defeat of anticopy enhancement pulses added to the active video portions of a video signal prior to synchronization pulses, comprising:

• logic circuitry for generating control signals o predetermined duration during the active video portions;
• and
• circuitry actuated by the control pulses for combining a predetermined video signal into the active video portion containing anticopy enhancement pulses,
• wherein said defeat apparatus decreases picture degradation caused by the anticopy pulses added to the active video portions of a video signal prior to synchronization pulses in a copied signal upon playback.

An apparatus for defeat of an anticopy enhancement modification to a copy protected video signal, the anticopy enhancement modification including reducing a duration of at least some of the horizontal synchronization pulses in the video signal so as to be less than a standard duration, the apparatus comprising:

• logic circuitry for determining a location of the horizontal blanking interval in at least certain lines of the video signal and generating a control signal in response;
• a pulse generator for generating a horizontal synchronization pulse of predetermined duration;
• and
• switch circuitry for adding the generated horizontal synchronization pulse to the video signal, the switch circuitry so adding in response to the control signal,
• wherein said generated horizontal synchronization pulse defeats the anticopy enhancement modification to said copy protected video signal.

An apparatus for defeating anticopy enhancement pulses by level shifting of the anticopy enhancement pulses present in the active video portions of a video signal, the anticopy enhancement pulses being located at the end of at least some video lines in the active portion thereof, comprising:

• a timing circuit for generating a control signal at a start of the anticopy pulses at the end of at least some video lines;
• a pulse generator for generating a pulse having a particular level above a blanking level of the video signal at the end of each video line, in response to the control signal;
• and
• means for adding the generated pulse to the video signal, thereby increasing a level of the end of each video line and defeating the effect of the anticopy enhancement pulses.

A method of defeating copy protection enhancement pulses added to a copy protected video signal, the copy protection enhancement pulses being of a type to cause a video retrace other than at occurrence of a video synchronization signal, and being located in an active video portion of the video signal, comprising the steps of:

• determining a location of the video synchronization signal;
• generating a pulse of an amplitude approximately that of the video synchronization signal;
• and
• adding the generated pulse to the video signal immediately prior to occurrence of the video synchronization signal,
• thereby defeating the effects of the copy protection enhancement pulses.