A method of converting a frame rate of a video signal includes the steps of: receiving a pulldown film sequence existing in or converted from a sequence of successive-in-time frames of the video signal, in which the pulldown film sequence comprises a plurality of diverse original frames each having a corresponding number of duplicate frames; modifying the original frames; performing estimation of at least one motion vector associated with the modified original frames; and interpolating new frames between the modified original frames in accordance with the motion vector.