Digital processing disruption systems

摘要

A method and apparatus are described for modifying an analogue video signal to impair its conversion to a digital signal by an analogue to digital converter. The resulting modified signal may prevent the operation of the analogue to digital converter altogether, or even if a digital signal can be output and recorded, may result in a signal which is difficult to view due to a reduction in quality on playback. The modifications made to the signal include altering the amplitude of the horizontal synchronization pulses in the original signal, and/or modifying the level of the back porch, or the region of the signal adjacent the back porch. Additionally, methods are contemplated for the use of specific response models for target analogue to digital converters, and display devices.

主权项

1. A method executable by a device to modify an analog video signal and thereby impair analog to digital conversion of the signal, the analog video signal comprising a plurality of horizontal synchronization pulses, each adjacent a respective back porch, the method comprising:
receiving the analog video signal for modification at the device; receiving disruption components from a remote source; modifying, by the device, at least one of the horizontal synchronization pulses of the signal from its original form to have a different amplitude over at least a part of the pulse width, wherein the modifying is configurable to be based upon the disruption components received from the remote source; additionally modifying the region of the signal following the horizontal synchronization pulse from its original form, wherein the additional modifying of the region following at least one of the horizontal synchronization pulses is configurable to be based upon the disruption components received from the remote source; and outputting the modified video signal by the device, wherein the modified video signal is such that the modified video signal interferes with the operation of an analog to digital video conversion system to such an extent that the output of the analog to digital video conversion system has a reduced quality on playback in comparison to the original analog video signal.