Video segmentation is among the most important challenges of video processing and compression (MPEG-4 and MPEG-7). A drawback of classical methods is the computational cost due to the model complexity. In this paper we propose to use a B-Spline parametric contour to implement a region-based active contour segmentation. Hence we get a fast variational method based on active contours with an intrinsic regularizing constraint. More precisely the evolution force follows from the minimization of a region-based criterion. The theory of B-Splines allows analytical computation of the contour curvature at any point. The model complexity is fixed and depends on the desired level of detail. This complexity is highly compared to non parametric methods. We compare our new approach to classical parametric polygon-based methods. We show experiments on real video sequences.