CPC H04N 19/105 (2014.11) [H04N 19/129 (2014.11); H04N 19/132 (2014.11); H04N 19/137 (2014.11); H04N 19/176 (2014.11)] | 17 Claims |
1. A video decoding method performed by a decoding apparatus, comprising:
obtaining motion prediction information for a current block from a bitstream;
constructing an affine Motion Vector Predictor (MVP) candidate list for the current block;
deriving Control Point Motion Vector Predictors (CPMVPs) for Control Points (CPs) of the current block based on the affine MVP candidate list;
deriving Control Point Motion Vector Differences (CPMVDs) for the CPs of the current block based on the motion prediction information;
deriving Control Point Motion Vectors (CPMVs) for the CPs of the current block based on the CPMVPs and the CPMVDs; and
generating a reconstructed picture for the current block by performing inter prediction on the current block based on the CPMVs,
wherein the constructing the affine MVP candidate list comprises:
checking whether an inherited affine MVP candidate is available, wherein the inherited affine MVP candidate is derived when the inherited affine MVP candidate is available;
checking whether a constructed affine MVP candidate is available, wherein the constructed affine MVP candidate is derived when the constructed affine MVP candidate is available, and the constructed affine MVP candidate includes a candidate motion vector for CP0 of the current block, a candidate motion vector for CP1 of the current block, and a candidate motion vector for CP2 of the current block;
when the number of derived affine MVP candidates including the inherited affine MVP candidate and the constructed affine MVP candidate is less than 2, deriving a first affine MVP candidate, wherein the first affine MVP candidate is an affine MVP candidate including a specific motion vector as candidate motion vectors for the CPs and the specific motion vector is an available motion vector among the candidate motion vector for the CP0, the candidate motion vector for the CP1, and the candidate motion vector for the CP2.
|