A frame interpolation method for a video processor includes the steps of: determining whether a first input frame is received following a long-term cadence; generating interpolated frames by applying phase coefficients in a regular phase table corresponding to the long-term cadence when the first input frame is received following the long-term cadence; and generating interpolated frames by applying phase coefficients in a bad edit phase table corresponding to a bad edit cadence when the first input frame is received without following the long-term cadence.