| 摘要 |
PURPOSE:To increase the secrecy by reversing the sequence of scanning lines of each block within the said block and replacing optionally the arrangement of the block to obtain scramble effect with a few number of blocks. CONSTITUTION:An analog video signal is inputted from a terminal 1, led to an A/D converter 3 and a master clock generator 4 through an LPF2, the generator 4 forms master clock having subcarrier frequencies fSC-3fSC based on a color burst signal and the result is fed to the A/D converter 3, a synchronizing separator 5 and a timing clock generating circuit 6. The converter 3 samples the input by using a master clock, converts it into a digital video signal, which is fed to a frame memory 7. Then the memory 7 has a capacity storing one frame of the video signal, written by a write address signal obtained from a ROM8, read by a read signal obtained from the ROM9 designated by a computer 10 and transmitted on a replaced scanning line. |
