Loading patent…
AssigneePayview Limited
InventorsJohn R. Thompson, Curtis J. Hunting, Ronald K. Masson, Craig E. Trivelpiece
Estimating the term…
A multimode scrambling system for video signal transmission systems is described. The system provides for baseband video scrambling controlled by a central originating computer facility. The scrambling of each field of a video changes on a per field basis. The video signal is scrambled in several modes including vertical interval scrambling, alternate line inversion, bogus sync pulse generation, video compression and video offset techniques. A scrambling sequence is sent by a unique algorithm, sent during the vertical interval to each system decoder. The algorithm is reordered for each of a plurality of fields of the video signal and the reordering position is identified by a unique synchronization pulse transmitted during the vertical interval of the video signal. Additional security measures are provided to inhibit a subscriber from avoiding a transmitted disable command, or an attempt to invade the subscriber decoder mechanical packaging security.
A method for scrambling a video signal, said video signal including a plurality of sequential fields, each field having a plurality of active line portions preceded by a horizontal synchronization period comprising:
A video signal scrambling system comprising:
In a system for scrambling a video signal, an apparatus for transmitting a signal identifying one of a plurality of scrambled sequences comprising:
In a system for scrambling and descrambling a video signal, in accordance with one of a plurality of scrambling algorithms, means for transmitting to a receiving station the identity of a scrambling sequence comprising:
In a system for scrambling and descrambling video signals, wherein a plurality of video lines are inverted in accordance with one of a series of scrambling sequences, a method for sending and receiving a decoding signal, comprising:
A system for scrambling a video signal with a different scrambling sequence for each field of said video signal comprising:
A system for scrambling a video signal which includes a plurality of fields of line information, each field separated by a vertical interval, comprising:
A system for descrambling a video signal including false synchronization pulses which are inserted in the video signal, an offset added to said video signal whereby active portions of said video signal are biased to below a black level, said video signal including during a specified line of said video signal, a reference black level and a white level, comprising:
In a system for scrambling a video signal, wherein each subscriber of the system includes a decoder which can be disabled by transmitting a disable command, a method to prevent said subscriber from avoiding a disable command by disconnecting said decoder comprising:
Dependencies are inferred from the claim text.