Synthesis device and method of vertical blanking signal

A method for controlling data transmission between a computer and a video client via an interface, the method comprising: the computer polling the interface(200) a first time to determine the size of the buffer on the interface; receiving a first buffer size value from the interface; sending a plurality of frames of video and audio data to the buffer on the interface such that a delay period exists between the sending of each frame; the computer polling the interface(204) a second time to determine buffer size after the frames are sent to the interface; receiving a second buffer size value from the interface; and modifying the amount(208,212) of time between the transmission of frames.