Patent ID: 9635380
Date: 2017-04-25
CPC Classifications: H04N

Claim:
1. A video decoding method comprising: generating a prediction block by performing inter prediction for a current block, determining whether to perform scaling on a motion vector of a reference block based on picture order count (POC) values of a first reference picture which the current block refers and a second reference picture which the reference block refers used for inter prediction for the current block, and scaling the motion vector of the reference block by calculating a first value and a second value based on the POC values, calculating an offset value by performing an arithmetic right shift on an absolute value of the first value by a binary digit of 1 and calculating an inverse-proportional value of the first value using the offset value, and calculating a scaling factor based on the inverse-proportional value and the second value, in response to scaling of the motion vector of the reference block being performed, wherein the first value is a POC difference between a picture including the reference block and the second reference picture, the second value is a POC difference between a current picture and the first reference picture, the POC indicates the order of display output, the motion vector of the reference block is scaled in response to the first reference picture not being the same as the second reference picture when a spatial motion vector is induced, the motion vector of the reference block is scaled in response to the POC difference between the current picture and the first reference picture not being the same as the POC difference between the picture comprising the reference block and the second reference picture when a temporal motion vector or a temporal merge candidate is induced, and the reference block used when the spatial motion vector is induced comprises at least one of a lowermost block adjacent to a left side of the current block, a block adjacent to a lower side of the lowermost block, a block diagonally adjacent to a upper-left corner of the current block, a rightmost block adjacent to the upper side of the current block and a block adjacent to a right side of the rightmost block.