Unrecordable video signals

摘要

A technique for handling video signals so as to permit such signals to be satisfactorily displayed on video display devices, such as TV receivers or monitors, but to prevent such signals from being satisfactorily recorded by video recording devices. In a particular embodiment thereof the video frame time base is altered in a selected manner, as by lengthening or shortening the time bases of successive video frames, or successive groups of video frames. The alterations thereof can be in discrete steps and be performed cyclically so that during each overall cyclical time period the cumulative error is zero.