A method equalizing sizes of data packets by blocks of a multimedia stream including a succession of data packets of variable sizes. The method includes: storing a group of N (a predefined integer) data packets in a buffer memory; computing average size Tm of a packet from the different sizes of the N packets; generating a base stream including N data packets to be transmitted, wherein each has a size equal either to the rounded-down integer part └Tm┘, or to the rounded-up integer part └Tm┘ of the average size, and at least one additional stream including N redundant data packets computed from the base stream packets, having same size as the base stream packets, and intended to enable a receiver to restore any lost packets if the loss rate is greater than a predefined threshold; and transmitting the base stream and the additional stream(s) to the receivers.