A method and a circuit for marking with a binary code a video sequence compressed by motion calculation, from one picture to another, of macroblocks dividing each picture, the digital pictures being distributed in at least two categories according to whether they are coded integrally or by the motion vectors of the macroblocks with respect to the previous picture or to the previous and next pictures, which includes, at least for the pictures coded by motion vectors, only marking the macroblocks for which the motion vectors are greater than a predetermined threshold.