Phase alternating line video signal processing apparatus

Abstract

Signal processing apparatus comprises a chrominance subsampler (10) for sampling the U and V components of a PAL video signal in response to an enable signal. A counter (30) responsive to the horizontal synchronization component of the PAL video signal generates the enable signal upon detection of a predetermined number of horizontal synchronization pulses. Logic (60,70,80) responsive to the vertical synchronization component of the PAL video signal resets and disables the counter (30) upon detection of a vertical synchronization pulse. Logic (50,60,70,80) restarts the counter (30) from a reset state upon detection of a predetermined polarity in the V component of the PAL video signal.

Dependencies are inferred from the claim text.