Scrambling of a video signal

Abstract

Abstract 2.1 Scrambling arrangements are known which prevent the reception of an original picture by unauthorised persons by means of simple measures. These scrambling arrangements, however, have high correlation which allows the video signal to be reproduced positionally correctly by unauthorised receivers by means of simple measures. 2.2 To achieve a correlation which tends towards zero, the video signal of one line is scrambled packet by packet within this line, the position of the lines in one field is exchanged and the fields or frames are exchanged within several fields or frames. 2.3 The invention is applied in protected broadcast transmissions.

Inventors

• 👤 Laurent Perdrieau

Bibliographic Details