System for the shifting of a television signal scrambler
AssigneeThomson Broadcast Systems
InventorsClaude Chapel, Philippe Lemonnier
Life of this patent
Estimating the term…
Abstract
The shifting system comprises a local scrambler (13) on a production site giving the necessary digital data elements to a scrambler (15) shifted to a transmission site. These data elements are inserted, at the image rate, into the compressed television signal transmitted on a low bit rate link to the transmission site. The application relates to systems for the transmission of encrypted television systems.
Claims14
A system for shifting a scrambler of a television signal coming from an audio and video source on a production site, the scrambled signal being transmitted to the subscriber from a transmission site different from the production site, wherein a local scrambler parameter determination mechanism on the production site receives the television signal to give digital data elements needed for the scrambling, but does not output a scrambled version of a video portion of said television signal, an encoder carries out a digital encoding of the television signal, said encoding depending on the signal entropy, the digital data elements and the encoded television signal are transmitted to the transmission site and a scrambler shifted to the transmission site scrambles the decompressed television signal on the basis of the digital data elements received by the transmission site.
A system comprising:
- a production facility having,
- a television signal source including an audio source that produces an audio signal and a video source that produces a video signal,
- a local scrambler parameter determination mechanism configured to produce digital data elements that relate to scrambling the video signal, said local scrambler determination mechanism configured to output said digital data elements, but not output a scrambled version of said video signal, and
- an encoder configured to receive said television signal and digitally, enthropically encode said television signal to form an encoded television signal, where the encoding depends on a signal entropy of the television signal, said encoder configured to receive and combine said digital data elements with said encoded television signal and to provide an output signal,
- a transmitter configured to transmit a scrambled television signal to a subscriber, having
- a decoder configured to receive said television signal and separate said digital data elements from said encoded television signal and decode said television signal, and
- a shifted scrambler configured to receive said digital data elements from said decoder and scramble said television signal with said digital data elements so as to provide said scrambled television signal;
- and
- a communication link that conveys said output signal from the production facility to the transmitter.
Dependencies are inferred from the claim text.