PURPOSE: To always reproduce a color difference signal accurately by generating a color burst gate signal even when a waveform of a horizontal synchronizing signal is deformed and the horizontal synchronizing separation is not accurately executed.

CONSTITUTION: When a horizontal synchronizing signal of an input video signal is deformed, a synchronizing separator circuit 12 cannot attain accurate synchronizing separation and the width of a synchronizing separation signal is narrower than that at a normal state. Thus, a gate generating circuit 13 detects a tail end of a synchronizing separation signal and a gate signal D is generated. Since the width of the gate signal D is as wide as, e.g. 8μs, even when the synchronizing separation is disturbed, a color burst is extracted by the gate signal. Thus, even when the horizontal synchronizing signal is deformed, the color burst is not in existence at the outside of the gate signal.