Method for equalizing the size of data packets by blocks of a multimedia stream

A method for equalizing a size of data packets by blocks of a multimedia stream including a succession of data packets of variable sizes to be transmitted in real time from a transmitter to one or more receivers, the method comprising:

• in the transmitter:
• storing a group of N data packets in a buffer memory, where N is a predefined integer;
• computing the average size 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, or to the rounded-up integer part of the average size, and at least one additional stream including N redundant data packets computed from the base stream packets, having a same size as the base stream packets, and intended to enable the receivers to restore any lost packets if the loss rate is greater than a predefined threshold;
• assessing reception conditions of the transmitted streams;
• transmitting to the receivers, either only the base stream if there is no loss of packets, or the base stream and at least one additional stream if packet loss occurs and if the loss rate is greater than a predefined threshold, a method in which the multimedia stream is transmitted in a multicast system with at least two layers using at least two multicast groups, wherein a first multicast group is used for transmission of the base stream and at least one other multicast group is used for transmission of at least one FEC stream;
• and
• in the receivers:
• configuring the receivers to receive either only the base stream if there is no packet loss, or the base stream and at least one additional stream if packet loss occurs and if the loss rate is greater than the predefined threshold.