Patent ID: 7256835

Claim:
A system, comprising: an input buffer adapted to receive a video stream in an interlaced format; and a processor configured to determine whether or not at least a portion of the video stream in said input buffer was originally in a progressive format by: (a) identifying a line of pixels that is missing from a field of the video stream; (b) calculating a base value for a pixel on the missing line; (c) calculating a difference value between the base value on the missing line and an actual value for a correspondingly located pixel on the corresponding line from a previous field, the corresponding line being not missing in the previous frame; (d) repeating operations recited in paragraphs (a), (b) and (c) for a plurality of consecutive fields; and (e) concluding that the video stream originated from a progressive format when the difference values alternate repetitively between a high value and low value for the plurality of consecutive fields.