1. A deinterlacing apparatus, comprising: a buffer to receive a plurality of consecutive fields of an interlaced video; a field combination module, coupled to the buffer, to deinterlace the interlaced video in accordance with cadence of the interlaced video; and a cadence detection module to detect the cadence by (1) causing each of the fields to be combined with its preceding field into a frame and with its subsequent field into another frame to obtain a plurality of combined frames, (2) determining a comb factor of each of the combined frames to obtain a sequence of comb factors of the combined frames by determining a comb factor value of each pixel in the frame and accumulating the comb factor value over all of the pixels within the frame to obtain the comb factor of that frame, and declaring the comb factor of a combined frame to be a high value if the accumulated comb factor value over all the pixels within the combined frame exceeds a pre-determined threshold while declaring the comb factor of the combined frame to be a low value if the accumulated comb factor value does not exceed the pre-determined threshold, and (3) determining if the sequence of comb factors of the combined frames follows a pre-determined repeating pattern.