Video encoder/decoder system
First Claim
Patent Images
1. A video encoder system for processing a video signal on an input terminal having alternate video portions and vertical interval portions, each video portion including video data and horizontal sync pulses, to provide a scrambled video signal on an output terminal, comprising:
- first encoder means for inverting a plurality of the horizontal sync pulses in a first section of said video signal, said first section including at least part of the video portion and excluding at least part of the vertical interval portion;
second encoder means for reducing the amplitude of each said inverted horizontal sync pulses in said first section; and
scrambling means for generating a scrambled video signal having said first section of said video signal which has been processed by said first and second encoder means and a second section of said video signal, being that portion of the video signal which has not been processed by said first and second encoder means.
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Accused Products
Abstract
An apparatus and method for encoding and decoding a television signal are disclosed in which the horizontal sync pulses and the first section of the video signal are inverted, and the inverted horizontal sync pulses and video signals are reduced in amplitude by a predetermined amount.
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Citations
53 Claims
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1. A video encoder system for processing a video signal on an input terminal having alternate video portions and vertical interval portions, each video portion including video data and horizontal sync pulses, to provide a scrambled video signal on an output terminal, comprising:
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first encoder means for inverting a plurality of the horizontal sync pulses in a first section of said video signal, said first section including at least part of the video portion and excluding at least part of the vertical interval portion; second encoder means for reducing the amplitude of each said inverted horizontal sync pulses in said first section; and scrambling means for generating a scrambled video signal having said first section of said video signal which has been processed by said first and second encoder means and a second section of said video signal, being that portion of the video signal which has not been processed by said first and second encoder means. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A video encoder system for processing an initial video signal having alternate video portions and vertical interval portions, each video portion including video data and horizontal sync pulses, and each vertical interval portion including a vertical sync pulse, vertical interval dalta, and horizontal sync pulses to provide a scrambled video signal comprising:
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first encoder means for inverting each at least a part of said video portion; second encoder means for modifying the amplitude of each said video portion including the video data and the horizontal sync pulses; scrambling means for alternately outputting video portions of a modified video signal which have been processed by said first and second encoder means and vertical interval portions of said initial video signal to provide said scrambled video signal; and timing means for detecting the horizontal and vertical sync pulses of said initial video signal and for controlling said scrambling means to provide said scrambled video signal. - View Dependent Claims (8, 9, 10, 11)
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12. A video decoder system for processing a scrambled video signal having an inverted portion including inverted horizontal sync pulses, and a noninverted portion including at least a part of the vertical interval, to provide an unscrambled video signal, the inverted video portion having an amplitude different than the amplitude of the noninverted portion comprising:
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first decoder means for re-inverting said inverted portion of said scrambled video signal; second decoder means for modifying the amplitude of the reinverted portion of said scrambled video signal to correspond to the amplitude of the noninverted portion; and combining means for generating said unscrambled video signal by alternately outputting the re-inverted portion which has been processed by said first and second decoder means and the noninverted portion of the scrambled video signal. - View Dependent Claims (13, 14, 15, 16, 17, 18)
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19. A video encoder system for processing a video signal on an input terminal having alternate video portions and vertical interval portions, each video portion including video data and horizontal sync pulses, and each vertical interval portion including a vertical sync pulse, vertical interval data, and horizontal sync pulses to provide a scrambled video signal on an output terminal, comprising:
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inverting amplifier means in communication with said input terminal for inverting the video signal and for reducing the amplitude of the input video signal to generate an inverted video signal; switching means in communication with said inverting amplifier means and said input terminal for alternately passing to the output terminal at least a part of the vertical sync pulse and a plurality of the horizontal sync pulses in the vertical interval portion of the input video signal and at least a part of the video portion of the inverted video signal to generate a scrambled video signal; detection means in communication with said input terminal for detecting and transmitting the horizontal and vertical sync pulses of the vertical interval portion; and control means in communication with said detection means and said switching means for generating a control signal for the switching means to generate said scrambled video signal in response to the horizontal and vertical sync pulses transmitted by the detection means to the control means. - View Dependent Claims (20, 21, 22)
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23. A video decoder system for processing a scrambled video signal on an input terminal, said scrambled video signal having an encoded section including inverted horizontal sync pulses and inverted video data, and a nonencoded section including at least a part of a vertical interval pulse and a plurality of horizontal sync pulses, to provide an unscrambled video signal on an output terminal, comprising:
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inverting means in communication with said input terminal for inverting the scrambled video signal to generate an inverted video signal; Amplifier means for increasing the amplitude of the encoded section of the inverted video signal to generate a decoded section of said inverted video section; switching means in communication with the amplifier means and with the input terminal for alternately passing to the output terminal the nonencoded section of the scrambled video signal from the input terminal and the decoded section of the inverted video signal from the inverting means, to generate said unscrambled signal; detection means in communication with said output terminal for detecting and transmitting at least a part of the vertical interval pulse and the plurality of horizontal sync pulses in said nonencoded section; and control means in communication with said detection means and said switching means for generating a control signal for the switching means to provide said unscrambled video signal in response to at least a part of the vertical interval pulse and the plurality of horizontal sync pulses transmitted by said detection means to the control means. - View Dependent Claims (24, 25)
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26. A method of encoding a video signal having alternate video portions and vertical interval portions, each video portion including video data and horizontal sync pulses, and each vertical interval portion including a vertical sync pulse and horizontal sync pulses, to provide a scrambled video signal, comprising:
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inverting a plurality of the horizontal sync pulses in a first section of said video signal, said first section including at least part of the video portion and excluding at least part of the vertical interval portion; reducing the amplitude of said inverted horizontal sync pulses in said first section; and generating a scrambled video signal comprising, alternately, said first section of said video signal which has been inverted and reduced and a second section of said video signal comprising that portion of the video signal which has not been inverted and reduced. - View Dependent Claims (27, 28)
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29. A method of decoding a scrambled video signal having an inverted portion including inverted horizontal sync pulses, and a noninverted portion including at least a part of the vertical interval, the inverted portion having an amplitude different than the amplitude of the noninverted portion, to provide an unscrambled video signal, comprising:
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inverting said inverted portion of said scrambled video signal to generate a re-inverted portion; modifying the amplitude of the re-inverted video portion of said scrambled video signal to correspond to the amplitude of the noninverted portion; and generating an unscrambled video signal comprising, alternately, said modified re-inverted portions and said noninverted vertical interval portions of the scrambled video signal. - View Dependent Claims (30)
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31. A method of encoding a normalized video signal having periodic video fields, each field having a first DC voltage reference level, comprising:
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inverting a portion of each field of the video signal to provide an inverted portion and a noninverted portion of the video signal, reducing the amplitude of said inverted portion of the video signal by a first predetermined amount; determining the first DC voltage reference levels of said inverted portion and said non-inverted portion; and shifting the inverted portion relative to the noninverted portion so that the first DC reference level of the inverted portion is offset by a second predetermined amount from the first DC reference level of the noninverted portion of the video signal. - View Dependent Claims (32, 33, 34, 35, 36, 37, 38)
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39. A method of encoding a normalized video signal having periodic video fields with video information sections and vertical interval sections, each field having a blanking level, a white level and a horizontal sync tip level, comprising:
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inverting the video information section of each field to generate an inverted portion and non-inverted portion of the video signal; reducing the amplitude of said inverted portion of the video signal by a first predetermined amount; sensing the blanking levels of the inverted portion and the noninverted portion; and shifting the blanking level of the inverted portion relative to the blanking level of the noninverted portion by a second predetermined amount. - View Dependent Claims (40, 41)
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42. A video encoding system for encoding a normalized video signal having periodic video fields, each field having a first DC voltage reference level, comprising:
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first encoding means for inverting aportion of each field of the video signal to provide an inverted portion and a noninverted portion of the video signal, second encoding means for reducing the amplitude of said inverted portion of the video signal by a first predetermined amount; means for determining the first DC voltage reference levels of said inverted portion and said noninverted portion; and control means for shifting the inverted portion relative to the noninverted portion so that the first DC reference level of the inverted portion is offset by a second predetermined amount from the first DC reference level of the noninverted portion of the video signal. - View Dependent Claims (43, 44, 45, 46, 47, 48, 49)
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50. A method of decoding a normalized scrambled video signal having periodic video fields, each field having an inverted portion and a noninverted portion with an amplitude greater than the inverted portion and a first DC voltage reference level relative to each of the inverted and noninverted portions, comprising
inverting said inverted portion of the scrambled video signal to generate a re-inverted portion; -
increasing the amplitude of the re-inverted portion to correspond to the amplitude of the noninverted portion of the scrambled video signal; determining the first DC voltage reference levels of the reinverted portion and the noninverted portion; and shifting the re-inverted portion relative to the noninverted portion by a predetermined amount so that the DC reference levels of the re-inverted portion and noninverted portion are substantially aligned. - View Dependent Claims (51)
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52. A video decoding system for decoding a normalized scrambled video signal having periodic video fields, each field having an inverted portion and a noninverted portion with an amplitude greater than the inverted portion and a first DC voltage reference level relative to each of the inverted and noninverted portions, comprising
first decoding means for inverting said inverted portion of the scrambled video signal to generate a re-inverted portion; -
second decoding means for increasing the amplitude of the reinverted portion to correspond to the amplitude of the noninverted portion of the scrambled video signal; means for determining the first DC voltage reference levels of the re-inverted portion and the noninverted portion; and control means for shifting the re-inverted portion relative to the noninverted portion by a predetermined amount so that the DC reference levels of the re-inverted portion and noninverter portion are substantially aligned. - View Dependent Claims (53)
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Specification