METHOD FOR DECODING CIPHERED TELEVISION SIGNAL AND SYSTEM THEREFOR

摘要

PROBLEM TO BE SOLVED: To improve security, secrecy, and complication by extending the part of the active video signal of at least one video line in a horizontal blanking period, and filling lines on the front port and rear port of the horizontal blanking period with color burst. SOLUTION: An input video signal is turned into a write clock signal by a synchronous connection 68, and turned into a digital video signal by a video A/D 74. The digital video signal and the output of a 1H buffer 76 for applying delay for one line are applied to an adder 78 so that a luminance signal Y can be obtained, and applied to a subtractor 80 so that a color difference signal C can be obtained. On the other hand, a write clock signal is temporarily locked by an address writing 70, and written in 1H buffers 82 and 84 synchronously with the luminance signal Y and the color difference signal C. As a result, a fluctuating video signal can be obtained by a read address 94.