A video signal and an audio signal are transmitted from a source device (400) to a sync device (410) in conformity with respective predetermined interfaces through respective transmission channels. The respective interfaces include bidirectional interface such as an HDMI and an IEEE1394. A controller (420) acquires delay information (TLv) representing the total delay time of the devices connectedto the transmission channels conforming to the bidirectional interface and corrects the difference in reproduction time between the video and audio signals by using the acquired delay information (TLv).