× 4 . ▁ ▁The ▁frame ▁to ▁be ▁c oded ▁is ▁divided ▁into ▁blocks ▁of ▁equal ▁size ▁as ▁shown ▁in ▁the ▁picture ▁above . ▁Each ▁block ▁prediction ▁will ▁be ▁blocks ▁of ▁the ▁same ▁size ▁as ▁the ▁reference ▁pictures , ▁offset ▁by ▁a ▁small ▁disp lacement . ▁ ▁Resol ution ▁of ▁up ▁to ▁ ¼ ▁pixel ▁motion ▁compens ation ▁ ▁P ix els ▁at ▁half - p ixel ▁position ▁are ▁obtained ▁by ▁applying ▁a ▁filter ▁of ▁length ▁ 6 . ▁ ▁H =[ 1 ▁- 5 ▁ 2 0 ▁ 2 0 ▁- 5 ▁ 1 ] ▁ ▁For ▁example : ▁ ▁b = A ▁- ▁ 5 B ▁+ ▁ 2 0 C ▁+ ▁ 2 0 D ▁- ▁ 5 E ▁+ ▁F ▁ ▁P ix els ▁at ▁quarter - p ixel ▁position ▁are ▁obtained ▁by ▁bil ine ar ▁interpolation . ▁ ▁While ▁M PE G - 2 ▁allowed ▁a ▁ ½ ▁pixel ▁resolution , ▁Inter ▁frame ▁allows ▁up ▁to ▁ ¼ ▁pixel ▁resolution . ▁That ▁means ▁that ▁it ▁is ▁possible ▁to ▁search ▁a ▁block ▁in ▁the ▁frame ▁to ▁be ▁c oded ▁in ▁other ▁reference ▁frames , ▁or ▁we ▁can ▁interpol ate ▁none x istent ▁pixels ▁to ▁find ▁blocks ▁that ▁are ▁even ▁better ▁su ited ▁to ▁the ▁current ▁block . ▁If ▁motion ▁vector ▁is ▁an ▁integer ▁number ▁of ▁units ▁of ▁samples , ▁that ▁means ▁it ▁is ▁possible ▁to ▁find ▁in ▁reference ▁pictures ▁the ▁compens ated ▁block ▁in ▁motion . ▁If ▁motion ▁vector ▁is ▁not ▁an ▁integer , ▁the ▁prediction ▁will ▁be ▁obtained