| 摘要 |
<p>An audio scrambler digitally samples a continuous audio signal, scrambles the derived samples and inserts at least one scrambled sample in the unoccupied region of the video signals of a video system for transmission line per line as an analog composite audio-video signal. A RAM device is used for this purpose which has the digital samples stored sequentially, then read at random. A special memory arrangement is used as a scratchpad in order to insure that while addressing the RAM at random there will be no repetition, nor omission of a particular address. Provision is made for the insertion of more than one sample per video line, in particular while transmitting severe audio signals on the same video system. The same technique is used at the receiver end for unscrambling the samples once extracted from the video lines.</p> |
