Method for synchronising and rendering multimedia streams

A synchronisation method for synchronising at least two rendering systems (12, 14) for rendering multimedia streams, one of the rendering systems (12, 14) being a main multimedia system (12) and at least one of the rendering systems (12, 14) being a dependent multimedia system (14), the method comprising:

• the detection (120) of a pulse (In) of a same signal of fixed frequency by each rendering system (12, 14) and by a main clock system (15),
• the generation (130), based on the detected pulse (In) of a main clock signal by the main clock system (15) in order to form a main time base, and, by each rendering system (12, 14), of a dependent clock signal in order to form a dependent time base;
• the estimation (150) by the main clock system (15) based on the detected pulse (ln) and the main clock signal, of a main local date (tp,n+1) of reception of the subsequent pulse (In+1) in the main time base, and by each rendering system (12, 14) based on the detected pulse (In) and the dependent clock signal of the said rendering system (12, 14) of a dependent local date (td,n+1) of reception of the subsequent pulse (In+1) in the dependent time base of the said rendering system (12, 14)
• for each rendering system (12, 14), the calculation (170) of the difference (Δn+1) between the main local date (tp,n+1) of the main clock system (15) and the dependent local date (td,n+1) of the considered rendering system (12, 14) and the storing of the calculated difference (Δn+1);
• for each rendering system (12, 14), the iteration of the previous steps (120, 130, 150, 170) until a first condition concerning the differences (Δn+1) calculated for the considered rendering system (12, 14) has been fulfilled,
• the receiving (190) of a multimedia stream by each of the rendering systems (12, 14);
• the sending (190), by the main multimedia system (12), at least to the dependent multimedia system (14), of a rendering date (tr) expressed in the time base of the main multimedia system (12), the rendering date (tr) being calculated based on the main clock signal and the differences calculated (Δn+1) for the main multimedia system (12);
• the calculation (200), by each rendering system (12, 14) in the time base of the considered rendering system (12, 14), of an effective date (te) of rendering of the multimedia stream based on the clock signal of the considered rendering system (12, 14), the rendering date (tr) and the calculated differences (Δn+1) for the considered rendering system (12, 14).