Video signal processing apparatus

A video signal processing apparatus comprising an oscillating unit (3) for outputting a signal of a stable frequency, a counting unit (4) for counting the period of a cycle of a signal supplied from the outside based on the signal output by the oscillating unit (3), a clock number calculating unit (5) for calculating the number of clocks in a line based on a result of counting by the counting unit (4), a comparing unit (7) for comparing the number of clocks calculated by the clock number calculating unit (5) with a threshold to decide which is larger, a switching unit (8) for deciding the number of clocks in the next operation by switching to the number of clocks calculated by the clock number calculating unit (5) if the calculated number of clocks is larger than the threshold, or deciding the number of clocks in the next operation by holding the number of clocks in a line in the current operation as it is, and a synchronizing signal generating unit (9) for, based on the number of clocks in operation decided by the switching unit (8) and the signal output by the oscillating unit (3), generating a synchronizing signal for a video signal, thereby preventing a shake of a frame signal supplied from the outside from directly affecting a synchronizing signal to be generated for a video signal so that a visually adverse shake of image on a TV screen can be suppressed.