Patent ID: 8073060
Filing Date: 2011-12-06
Classification: H04N

Abstract:
1. A method of synchronizing the phase of a local image frame synchronization signal generator of a local video data processor in communication with an asynchronous switched packet network to the phase of a reference image frame synchronization signal generator of a reference video data processor also coupled to said network, said local and reference processors having respective clocks, said reference and local image frame synchronization signal generators generating periodic image frame synchronization signals in synchronism with said reference and local clocks respectively, said method comprising the steps of: frequency synchronizing said local and reference clocks; said reference video data processor sending, via said network, to said local data processor one image timing packet providing reference image frame synchronization data indicating a difference in timing, measured with respect to said reference processor's clock, between a time at which said image timing packet is launched onto said network and a time of production of a reference image frame synchronization signal; said local video data processor controlling the phase of production of said local image frame synchronization signals in dependence on said reference image frame synchronization data and a time of arrival of said one image timing packet; and sending to said local video data processor from said reference video data processor, via said network, data packets containing video data, said image timing packet being sent independently of said data packets.