Method and apparatus for disabling anti-copy protection system in video signals

A method for disabling the effects of copy-protect signals added to blanking intervals of a video signal having normal sync pulses, said copy-protect signals including at least one added AGC pulse, said method comprising the steps of:

• detecting said blanking interval of said video signal;
• identifying the position of said at least one added AGC pulse;
• and
• developing altered video signals in response to said detecting and identifying steps in a manner so as to alter the copy-protect signals to reduce their effectiveness in copy-prevention;
• wherein said copy-protect signals inhibit copying by a video cassette recorder and wherein said developing step comprises altering, reproducing or regenerating said copy-protect signals in a manner where internal characteristics of said video cassette recorder inherently nullify the effects of said copy-protect signals;
• and
• wherein said developing step comprises increasing a frequency of said copy-protect signals beyond an effective bandwidth of a video cassette recorder.

A method for reducing the effect of copy-protect signals in a blanking interval of a video signal wherein said copy-protect signals include at least one added AGC pulse, and said blanking interval includes at least one normal sync pulse, said method comprising the steps of:

• receiving an input video signal from said recording medium;
• detecting the normal sync signal and identifying the location of said copy-protect signals on the basis of the detected normal sync signal;
• generating copy-protect disabling signals which increase a frequency of said copy-protect signals beyond an effective bandwidth of a video cassette recorder in accordance with said detecting step;
• and
• transmitting an output video signal comprising a composite of said input video signal and said disabling signals.

A method for reducing the effect of copy-protect signals in a vertical blanking interval of a video signal wherein said copy-protect signals include at least one pseudo-sync pulse and an added AGC pulse, and said blanking interval includes at least one normal vertical sync pulse, said method comprising the steps of:

• receiving an input video signal from said recording medium;
• detecting the vertical sync signal and identifying the location of said copy-protect signals on the basis of the detected vertical sync signal;
• generating copy-protect disabling signals which increase a frequency of said copy-protect signals beyond an effective bandwidth of a video cassette recorder in accordance with said detecting step;
• and
• transmitting an output video signal in accordance with a representation of said input video signal and said disabling signals.

An apparatus for disabling the effects of copy-protect signals in a video signal, said copy-protect signals including at least one added AGC pulse, said apparatus comprising:

• receiving means for receiving an input signal representative of said video signal;
• detection means connected with said receiving means for detecting said copy-protect signals;
• signal disabling means responsive to said detection means for generating disabling signals;
• and
• output means for transmitting an output video signal in accordance with a representation of said input video signal and said disabling signals;
• wherein said signal disabling means includes level-shifting means for effecting transmission of an output video signal at least a portion of which having its D.C. level shifted.

An apparatus for disabling the effects of copy-protect signals in a video signal, said copy-protect signals including at least one added AGC pulse, said apparatus comprising:

• receiving means for receiving an input signal representative of said video signal;
• detection means connected with said receiving means for detecting said copy-protect signals;
• signal disabling means responsive to said detection means for generating disabling signals;
• and
• output means for transmitting an output video signal in accordance with a representation of said input video signal and said disabling signals;
• wherein said disabling means includes means for increasing an effective frequency of said copy-protect signals.

An apparatus for disabling the effects of copy-protect signals contained in vertical blanking intervals of a video signal, said copy-protect signals including at least one added pseudo-sync signal and one added AGC pulse, said apparatus comprising:

• receiving means for receiving an input signal representative of said video signal from said recording medium;
• detection means connected with said receiving means for detecting said vertical blanking interval which includes said copy-protect signals;
• signal disabling means responsive to said detection means for generating disabling signals during the occurrence of at least a portion of said copy-protect signals;
• and
• output means for transmitting an output video signal in accordance with a representation of said input video signal and said disabling signals;
• wherein said detection means comprises a sync separator for detecting the vertical blanking interval of the video signal, said disabling means comprises means for generating a D.C. level-shifting signal during a portion of the vertical blanking interval, and said output means includes means for combining the D.C. level-shifting signal with a representation of the input video signal, thereby to transmit an output video signal having disabled copy-protect signals.

An apparatus for disabling the effects of copy-protect signals contained in vertical blanking intervals of a video signal, said copy-protect signals including at least one added pseudo-sync signal and one added AGC pulse, said apparatus comprising:

• receiving means for receiving an input signal representative of said video signal from said recording medium;
• detection means connected with said receiving means for detecting said vertical blanking interval which includes said copy-protect signals;
• signal disabling means responsive to said detection means for generating disabling signals during the occurrence of at least a portion of said copy-protect signals;
• and
• output means for transmitting an output video signal in accordance with a representation of said input video signal and said disabling signals;
• wherein said detection means comprises a sync separator for separating the vertical blanking interval from the remaining video signal, said disabling means comprises means for increasing an effective frequency of said copy-protect signals thereby to produce altered signals, and said output means includes means for transmitting the altered signals and a representation of the input video signal.