Patent ID: 8254461

Claim:
A method of decoding coded video data, comprising: calculating, for a current frame of video data to be decoded, a scale factor (Z) based on a ratio of two time differences (Δt 1 /Δt 2 ), the first time difference (Δt 1 ) representing a temporal difference between the current frame and a first reference frame and the second time difference (Δt 2 ) representing a temporal difference between the first reference frame and a second reference frame, the scale factor representing the ratio multiplied by a power of two (Z=2 N *(Δt 1 /Δt 2 )) subject to rounding, predicting data of pixelblocks of the current frame from data of the reference frames according to predictive coding techniques, and further comprising, as part of the prediction, interpolating a motion vector (mv PB ) of the pixelblocks from a motion vector (mv REF ) of a co-located pixelblock in one of the reference frames as mv PB =mv REF *Z/2 N .