Modifying a television signal to inhibit recording/reproduction

A method of modifying a composite television signal to inhibit the reproduction of an unauthorized recording thereof by conventional video recorders but enable the display of a video picture therefrom on a television receiver, comprising:

• increasing above a standard number of horizontal line intervals normally included in a frame the number of horizontal line intervals included in a first predetermined number of frames of the television signal;
• decreasing below said standard number the number of horizontal line intervals included in a second predetermined number of frames of the television signal;
• the rate at which the numbers of horizontal line intervals are increased and decreased, the maximum and minimum numbers of horizontal line intervals in a frame to which said numbers of horizontal line intervals are increased and decreased, and the first and second predetermined numbers of frames containing the increased and decreased numbers of horizontal line intervals all corresponding to a profile pattern representing changes with respect to time in the number of horizontal line intervals in a frame and having a positive portion representing said first predetermined number of frames containing more than said standard number of horizontal line intervals in each frame and a negative portion representing said second predetermined number of frames containing less than said standard number of horizontal line intervals in each frame;
• and
• selectively changing said profile pattern from among a plurality of profile patterns and correspondingly changing at least one of the following:
• (a) the rate at which the number of horizontal line intervals in a frame change;
• (b) the maximum number of horizontal line intervals included in a frame;
• (c) the minimum number of horizontal line intervals included in a frame;
• (d) the first predetermined number of frames containing more than said standard number of horizontal line intervals;
• and (e) the second predetermined number of frames containing less than said standard number of horizontal line intervals.

Apparatus for modifying a composite television signal to inhibit reproduction of an unauthorized recording thereof by conventional video recorders but enable the display of a video picture therefrom on a television receiver, comprising:

• line duration increasing means for increasing the time durations of horizontal line intervals included in a first predetermined number of frames of the television signal from a standard horizontal line duration to a pre-established maximum time duration and then decreasing said time durations from said pre-established maximum to said standard;
• line duration decreasing means for decreasing the time durations of the horizontal line intervals included in a second predetermined number of frames of the television signal from said standard to a pre-established minimum time duration and then increasing said time durations from said pre-established minimum to said standard;
• and
• means for limiting the increase and decrease in the time durations of said horizontal line intervals such that the accumulated increase or decrease over a vertical interval is less than 200 nsec.

Apparatus for modifying a composite television signal to inhibit the reproduction of an unauthorized recording thereof by conventional video recorders but enable the display of a video picture therefrom on a television receiver, comprising:

• line interval increase means for increasing above a standard number of horizontal line intervals normally included in a frame the number of horizontal line intervals included in a first predetermined number of frames of the television signal;
• line interval decrease means for decreasing below said standard number the number of horizontal line intervals included in a second predetermined number of frames of the television signal;
• profile means for providing a profile pattern representing changes with respect to time in the number of horizontal line intervals in a frame, said profile pattern having a positive portion representing said first predetermined number of frames containing more than said standard number of horizontal line intervals in each frame and a negative portion representing said second predetermined number of frames containing less than said standard number of horizontal line intervals in each frame;
• means for selectively changing said profile pattern from among a plurality of profile patterns;
• and
• means for applying said profile pattern to said line interval increase and decrease means for changing at least one of the following:
• (a) the rate at which the number of horizontal line intervals in a frame change;
• (b) the maximum number of horizontal line intervals included in a frame;
• (c) the minimum number of horizontal line intervals included in a frame;
• (d) the first predetermined number of frames containing more than said standard number of horizontal line intervals;
• and (e) the second predetermined number of frames containing less than said standard number of horizontal line intervals.

Apparatus for transmitting to subscribers a modified composite television signal which inhibits reproduction of an unauthorized recording thereof by conventional video recorders but enables the display of a video picture therefrom on a television receiver included in a subscription television distribution system, said apparatus comprising:

• source means for providing television program signals to be transmitted via said subscription television distribution system;
• fingerprint location means for identifying locations in the television program signals into which fingerprint data related to the television program may be inserted and for producing fingerprint location data indicative thereof;
• profile data means for providing profile data of a profile pattern representing changes with respect to time of the vertical periods of the television program signals;
• scramble means for rearranging the television program signals to produce scrambled television signals and for producing scramble map data indicative of the rearrangement of the television program signals;
• means for inserting the fingerprint location data, the profile data and the scramble map data into predetermined portions of the rearranged television program signals;
• means for supplying to said subscription television distribution system the rearranged television program signals having said fingerprint location data, profile data and scramble map data inserted therein;
• and
• vertical period adjustment means responsive to the supplied profile data for modifying the vertical periods of the television program signals prior to transmission of the television program signals to subscribers via said subscription television distribution system, said vertical period adjustment means including memory means for temporarily storing and reading out successive field intervals of the scrambled television signals so as to modify said vertical periods and for returning the rearranged scrambled television signals to descrambled form.

A method of modifying a composite television signal to inhibit the reproduction of an unauthorized recording thereof by conventional video recorders but enable the display of a video picture therefrom on a television receiver, comprising:

• digitizing each horizontal line interval of active video information in each frame of the television signal;
• writing a fixed number of the digitized active video line intervals into memory means and subsequently reading from said memory means the fixed number of digitized active video line intervals;
• converting the digitized active video line intervals read from said memory means to analog form;
• generating horizontal line intervals of nonactive video information;
• and
• adding a variable number of generated horizontal line intervals of nonactive video information to the analog active video line intervals read from said memory means, whereby the total number of line intervals included in a frame is selectively greater than or less than a standard number of horizontal line intervals normally included in a frame, depending upon the number of line intervals of nonactive video information added to the active video line intervals.

Apparatus for modifying a composite television signal to inhibit the reproduction of an unauthorized recording thereof by conventional video recorders but enable the display of a video picture therefrom on a television receiver, comprising:

• means for deriving from said composite television signal a fixed number of horizontal line intervals of active video information in each frame of the television signal;
• nonactive video line interval generating means for generating horizontal line intervals of nonactive video information;
• combining means for combining the fixed number of active video line intervals with the nonactive video line intervals to produce an output frame;
• and
• means for varying the number of nonactive video line intervals which are combined with the fixed number of active video line intervals such that the total number of line intervals included in an output frame is selectively greater than or less than a standard number of horizontal line intervals normally included in a frame, depending upon the number of nonactive video line intervals which are combined.

A method of modifying a composite television signal to inhibit the reproduction of an unauthorized recording thereof by conventional video recorders but enable the display of a video picture therefrom on a television receiver, comprising:

• increasing above a standard number of horizontal line intervals normally included in a frame the number of horizontal line intervals included in a first predetermined number of frames of the television signal;
• decreasing below said standard number the number of horizontal line intervals included in a second predetermined number of frames of the television signal;
• the rate at which the numbers of horizontal line intervals are increased and decreased, the maximum and minimum numbers of horizontal line intervals in a frame to which said numbers of horizontal line intervals are increased and decreased, and the first and second predetermined numbers of frames containing the increased and decreased numbers of horizontal line intervals all corresponding to a profile pattern representing changes with respect to time in the number of horizontal line intervals in a frame and having a positive portion representing said first predetermined number of frames containing more than said standard number of horizontal line intervals in each frame and a negative portion representing said second predetermined number of frames containing less than said standard number of horizontal line intervals in each frame;
• selectively changing said profile pattern and correspondingly changing at least one of the following:
• (a) the rate at which the number of horizontal line intervals in a frame change;
• (b) the maximum number of horizontal line intervals included in a frame;
• (c) the minimum number of horizontal line intervals included in a frame;
• (d) the first predetermined number of frames containing more than said standard number of horizontal line intervals;
• and (e) the second predetermined number of frames containing less than said standard number of horizontal line intervals;
• and
• compensating for vertical shift otherwise present in a video picture displayed from the modified television signal caused by said increasing and decreasing of the number of horizontal line intervals in said frames.

Apparatus for modifying a composite television signal to inhibit the reproduction of an unauthorized recording thereof by conventional video recorders but enable the display of a video picture therefrom on a television receiver, comprising:

• line interval increase means for increasing above a standard number of horizontal line intervals normally included in a frame the number of horizontal line intervals included in a first predetermined number of frames of the television signal;
• line interval decrease means for decreasing below said standard number the number of horizontal line intervals included in a second predetermined number of frames of the television signal;
• profile means for providing a profile pattern representing changes with respect to time in the number of horizontal line intervals in a frame, said profile pattern having a positive portion representing said first predetermined number of frames containing more than said standard number of horizontal line intervals in each frame and a negative portion representing said second predetermined number of frames containing less than said standard number of horizontal line intervals in each frame;
• means for selectively changing said profile pattern;
• means for applying said profile pattern to said line interval increase and decrease means for changing at least one of the following:
• (a) the rate at which the number of horizontal line intervals in a frame change;
• (b) the maximum number of horizontal line intervals included in a frame;
• (c) the minimum number of horizontal line intervals included in a frame;
• (d) the first predetermined number of frames containing more than said standard number of horizontal line intervals;
• and (e) the second predetermined number of frames containing less than said standard number of horizontal line intervals;
• and
• means for compensating for vertical shift otherwise present in a video picture displayed from the modified television signal caused by said increasing and decreasing of the number of horizontal line intervals in said frames.