An apparatus includes a generating unit and a transmitting unit. The generating unit generates synchronization format information regarding a vertical synchronizing frequency and a horizontal synchronizing frequency of a first video synchronizing signal, and generates phase difference information indicating a phase difference between the first video synchronizing signal and a first reference signal synchronized with a grand master clock. The transmitting unit transmits the synchronization format information and the phase difference information to an external apparatus that can generates a second video synchronizing signal synchronized with the first video synchronizing signal.