How to scramble video signal
At present, there are many scrambling technical solutions, so there are many classification methods, such as scrambling mode and non-scrambling mode, analog mode and digital mode, band signal scrambling method and radio frequency signal scrambling method, time base processing method and frequency domain processing. But either way, the idea is to make it impossible for unauthorized users to receive normal signals.
Disturbing the normal signal, the first is to use the analog signal processing method to destroy the line and field synchronization of the TV signal, causing the distortion and jitter of the TV image; the second is to randomly change the grayscale or color of the image; the third is to use the digital processing technology to make the analog TV image. The pixel position in the system produces random spatial displacement; the fourth is to use digital encryption technology to change the sample value and pixel position of the digital TV signal.