VIDEO SIGNAL SCRAMBLE METHOD

摘要

PURPOSE:To eliminate waveform distortion by allowing an encoder to multiplex a video signal in the vicinity of a cut point as a digital data onto a signal within a vertical blanking period and allowing a decoder to replace a video signal in the vicinity of a connecting point as a digital data into the video signal in the vicinity of the cut point multiplexed in the vertical blanking period. CONSTITUTION:A video signal is inputted to an input terminal 1 and given to a synchronizing separator circuit 2 and an A/D converter 3 and a synchronizing signal is separated and given to a timing signal generating circuit 4. An analog signal given to the A/D converter 3 is converted into a digital signal and given to a picture memory 5 and an extraction memory circuit 7. A control signal representing a cut point of each scanning line is inputted and given to a memory address generating circuit 6. An address to write a video signal from the A/D converter 3 to the picture memory 5 and a read address for line rotation are generated. Scrambling is implemented by line rotation, and an encoder side uses a video signal in the vicinity of the connecting point as a digital data is replaced into the video signal in the vicinity of the cut point multiplexed in the vertical blanking period to eliminate waveform distortion thereby improving the decoded quality of the descramble picture.