Method of YC separation of YC separation filter

1. A YC separation filter comprising:

a YC separation circuit for separating luminance signal and chromatic signal from an input composite video signal sampled by predetermined clock timing, adaptive to a motion of the composite video signal, by one frame delayed signal and two frames delayed signal of the input composite video signal;

a decoder for decoding a color difference signal from the chromatic signal outputted from the YC separation circuit, and obtaining a phase value of a sub carrier of the input composite video signal;

a sampling phase detection means for detecting sampling phase information under sampling period of predetermined clock and the phase value of the sub carrier;

a delay means for receiving a time-series combined signal of the input composite video signal and the sampling phase information, and outputting a first combined signal delayed for one frame and a second combined signal delayed for two frames through a memory;

a first compensation filter for outputting composite video signal in the first combined signal by controlling a transfer function of the first compensation filter to synchronize sampling phase extracted from the first combined signal and the sample phase information from the sampling phase detection means;

a second compensation filter for outputting composite video signal in the second combined signal by controlling a transfer function of second compensation filter to synchronize sampling phase extracted from the second combined signal and the sample phase information from the sampling phase detection means; and

a control means for controlling the delay means by one clock order based on a timing signal which becomes predetermined value once in the timing corresponding to the sampling phase information from the sampling phase detection means;

wherein the first compensation filter provides the first combined signal delayed for one frame as an one frame delayed signal, and the second compensation filter provides the second combined signal delayed for two frames as a two frames delayed signal.

2. A method for YC separation of a composite video signal comprising the steps of;

separating luminance signal and chromatic signal from an input composite video signal sampled by predetermined clock timing, by one frame delayed signal and two frames delayed signal of the input composite video signal adaptive to the motion of the input composite video signal;

decoding a color difference signal from the chromatic signal separated from the input composite video signal, and obtaining a phase value of the sub carrier of the input composite video signal;

detecting sampling phase information under sampling period of a predetermined clock and the phase value of sub carrier of the input composite video signal;

outputting through a memory, one frame delayed signal and two frames delayed signal respectively, which signal is combined the input composite video signal with the sampling phase information;

compensating a phase information of one frame delayed signal to synchronize the phase information of one frame delayed signal and the sampling phase information, and compensating the phase information of two frames delayed signal to synchronize the phase information of the two frames delayed signal and the sampling phase information;

controlling one clock order based on a timing signal which becomes predetermined value once in the timing corresponding to the sampling phase information from the sampling phase detection means;

wherein a first compensation filter provides a first combined signal delayed for one frame as said one frame delayed signal, and a second compensation filter provides a second combined signal delayed for two frames as said two frames delayed signal.