Scrambling and descrambling of video signals using horizontal line combinations
First Claim
1. A method of scrambling a video signal having first and second components to produce a scrambled video signal, comprising the steps of:
- delaying the first component in time to produce a delayed first component; and
combining the second component with the delayed first component to produce the scrambled video signal.
5 Assignments
0 Petitions
Accused Products
Abstract
A plurality of video lines in a raster scan video image are scrambled by delaying a first video line in time equal to the horizontal line scan time for the raster scan video field to produce a delayed first video line. The delayed first video line is inverted to produce an inverted delayed first video line and one of the delayed first video line, the inverted delayed first video line and a null signal is added to a second horizontal video line to produce a horizontal line of a scrambled video signal. The scrambled horizontal lines of video information are descrambled by delaying a first scrambled horizontal video line in time equal to the horizontal line scan time for the raster scan video field to produce a delayed first scrambled video line. The delayed first scrambled video line is inverted to produce an inverted delayed first scrambled video line and one of the delayed first scrambled video line, the inverted delayed first scrambled video line and a null signal is added to a second scrambled horizontal video line and to a feedback signal to produce a descrambled horizontal video line.
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Citations
38 Claims
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1. A method of scrambling a video signal having first and second components to produce a scrambled video signal, comprising the steps of:
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delaying the first component in time to produce a delayed first component; and combining the second component with the delayed first component to produce the scrambled video signal. - View Dependent Claims (2, 3, 4)
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5. A method of descrambling a scrambled video signal having first and second scrambled components to produce a first component of a descrambled video signal having first and second components, comprising the steps of:
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delaying the first scrambled component in time; combining the delayed first scrambled component, the second scrambled component and a feedback signal to produce the first component of the descrambled video signal; and delaying the second component of the descrambled video signal in time to produce the feedback signal. - View Dependent Claims (6, 7, 8)
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9. A method of scrambling a plurality of video lines in a raster scan video image for a video field comprising the steps of:
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(1) delaying a first video line in a time equal to the horizontal line scan time for the raster scan video field to produce a delayed first video line; (2) inverting the delayed first video line to produce an inverted delayed first video line; (3) selecting one of, (a) the delayed first video line, or (b) the inverted delayed first video line, or (c) a zero-level signal (4) adding a second video line to the selected one of (a), (b), or (c); and (5) repeating steps (1)-(4) for each of the plurality of video lines of the video field. - View Dependent Claims (10, 11)
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12. A method of descrambling a plurality of scrambled video lines in a raster scan video image for a video field comprising the steps of:
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(1) delaying a first scrambled video line an amount of time equal to the horizontal line scan time for the raster scan video field to provide a delayed first scrambled video line; (2) inverting the delayed first scrambled video line to provide an inverted delayed first scrambled video line; (3) selecting one of, (a) the delayed first scrambled video line, or (b) the inverted delayed first scrambled video line, or (c) a zero-level signal (4) adding a second scrambled video line to the selected one of (a), (b), or (c) and to a feedback signal to produce a descrambled video line; (5) developing the feedback signal from a delayed descrambled video line; and (6) repeating steps (1)-(5) for each of the plurality of scrambled video lines of the video field. - View Dependent Claims (13, 14, 15)
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16. An apparatus for scrambling a video signal having first and second components to produce a scrambled video signal, including:
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means for delaying the first component in time to produce a delayed first component; means coupled to the delaying means for combining the second component with the delayed first component to produce the scrambled video signal. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23, 24, 25)
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26. An apparatus for descrambling a scrambled video signal having first and second scrambled components to produce a first component of a descrambled video signal having first and second components, comprising:
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means for delaying the first scrambled component in time; means for combining the delayed first scrambled component, the second scrambled component and a feedback signal to produce the first component of the descrambled video signal; and means responsive to the second component of the descrambled video signal for producing the feedback signal. - View Dependent Claims (27, 28, 29, 30, 31, 32, 33, 34, 35, 36)
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37. A method of transmitting a video signal having first and second original components to develop a reproduced video signal having first and second reproduced components, comprising the steps of:
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delaying the first original component of the video signal in time to produce a delayed first original component; combining the second original component of the video signal with the delayed first original component to produce a portion of a scrambled video signal having first and second scrambled components; transmitting the scrambled video signal; receiving the transmitted scrambled video signal; delaying the first scrambled component of the received scrambled video signal in time; combining the delayed first scrambled component of the received scrambled video signal, the second scrambled component of the received scrambled video signal and a feedback signal to develop the first reproduced component of the reproduced video signal; and delaying the second reproduced component of the reproduced video signal to produce the feedback signal. - View Dependent Claims (38)
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Specification