METHODS OF PROVIDING TIMING INFORMATION FOR SYNCHRONIZING MMT PACKET STREAMS IN MMT HYBRID DELIVERY SERVICE AND METHODS OF SYNCHRONIZING MMT PACKET STREAMS IN MMT HYBRID DELIVERY SERVICE

摘要

PURPOSE: A timing information providing method an MMT packet stream synchronization method are provided to obtain the absolute time information for synchronization of each media device transmitted from each server using timing information. CONSTITUTION: A first server(310) transmits a first media entity. The second server(350) transmits a second media entity. The second server generates timing information for synchronization of a second packet including the second media entity and a first packet including the first media entity(351). The second server provides the timing information and the second packet including the second media entity to a client(359). The timing information included in a control message of an MMT C.2 layer is provided to the client(313-2). [Reference numerals] (310) First server; (311) Generating an MMT packet; (313-1,313-2) First MMT packet including a foreign film; (315) First MMT packet including a default subtitle; (330) Client; (331) Requesting the foreign film and the default subtitle; (333) De-packetizing and synchronizing the first MMT packet and playing; (335) Requiring SDH subtitle viewing by a user; (337) Requesting the SDH subtitle; (339) Determining the synchronization between two media objects; (341) De-packetizing the first and second MMT packets and playing the synchronized foreign film and the SDH subtitle; (350) Second server; (351) Generating timing information by calculating start_clock_offset, MCR_0; (353) Control message of a C layer; (357) Generating a second MMT packet; (359) Second MMT packet including the SDH subtitle