Scrambling and descrambling of video signals using horizontal line combinations

摘要

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.