1. A method for transmitting video data encoded in a scalable video stream representing said video data in a plurality of layers, comprising, for at least one layer: a step of obtaining pre-encoded macroblocks of said scalable video stream representing said video data in a plurality of layers, a step of grouping macroblocks, used for inter layer prediction, of the pre-encoded macroblocks obtained by the obtaining step, into first groups of macroblocks, a step of grouping macroblocks, not used for inter layer prediction, of the pre-encoded macroblocks obtained by the obtaining step, into second groups of macroblocks, a step of estimating a loss variability over a network, a step of selecting groups of macroblocks from the first and second groups of macroblocks based on the loss variability estimated by the estimating step and a step of transmitting the groups of macroblocks selected by the selecting step over the network.