1. A method comprising: selection by a device, for a current image portion to be encoded and for at least one encoding module included in a video encoder, of at least one encoding parameter from amongst a set of encoding parameters available for said at least one encoding module, the selection being based on a decision model defining a minimization, under a rate constraint, of a first measurement of distortion D between source samples, included in said current image portion to be encoded, and current reconstructed samples, included in a current reconstructed image portion, obtained from the current image portion to be encoded; and wherein the decision model defines said minimization under an additional smoothness constraint, pertaining to a second measurement of distortion D′ between said current reconstructed samples and preceding reconstructed samples, belonging to a temporal reference neighborhood comprising at least one preceding reconstructed image portion obtained from at least one preceding encoded image portion.