Patent ID: 6968007

Claim:
A method of modifying data in an input coded video signal for generating an output video signal, each video signal corresponding to a sequence of coded video frames, said method comprising at least: an error decoding step for delivering a decoded data signal from a current input coded video frame, a re-encoding step for delivering an output video frame, carried by said output video signal, from a modified signal, said modified signal resulting from an adding sub-step between a motion-compensated signal and said decoded data signal, a reconstruction step for delivering a coding error of said output video frame, a motion-compensation step for delivering said motion-compensated signal from a stored coding error of a previous output video frame, characterized in that said method comprises: a first switching step inserted between said re-encoding step and said reconstruction step for activating said reconstruction step, a second switching step inserted between said motion-compensation step and said adding sub-step for activating said motion-compensation step, said switching steps being controlled independently by a control strategy for defining a scalable method defining four architectures for modifying said input coded video signal; wherein the control strategy of said first switching step, performed at the macroblock level, comprises: a first prediction sub-step of the energy of said coding error, said coding error energy being predicted for all re-encoded macroblocks of an output video frame, a first selection sub-step for identifying, among macroblocks defining said coding error, a first set of macroblocks having a predicted coding error energy below a given threshold, the coding error of said first set of macroblocks being set to a zero value so as to result in a modified stored coding error, a second selection sub-step for identifying, among macroblocks defining said coding error, a second set of macroblocks having a predicted coding error energy above said given threshold, said first switching step activating the reconstruction step for said second set of macroblocks.