市面上销售的录像带有些是经过加密处理的。录像带的加密过程是,当复制录像带时,在母带放像机输出的视频信号中的色同步信号后图像信号前,加入行同步信号干扰脉冲,再输入到经改制的子带录像机中,这时复制的子录像带就有加密特性了。如果把这样经过加密的子录像带作为母带,再进行下一级子带的复制,则复制出的再下一级子带在普通的录像机上放像 Some of the video tapes on the market are encrypted. Video tape encryption process is, when the tape copy, the master video player output video signal after the burst signal before the image signal, add the line sync signal interference pulse, and then input to the modified sub-video recorder, then copy The sub-video has the encryption feature. If the encrypted sub-video tape is used as a master tape and then the next-level sub-tape is copied, the reproduced next-level sub-tape is played on a normal video recorder