CPC H04N 19/107 (2014.11) [H04N 19/176 (2014.11); H04N 19/184 (2014.11); H04N 19/513 (2014.11); H04N 19/70 (2014.11)] | 13 Claims |
1. A video decoding method for decoding a sequence of coded pictures on a block-by-block basis, comprising:
setting, at a sequence level, whether affine motion prediction is allowed by decoding a first high-level syntax element from a bitstream;
setting, at a picture level, whether each of at least one coding tool is allowed by decoding one or more second high-level syntax elements for each of the at least one coding tool from the bitstream depending on the first high-level syntax element, the at least one coding tool including sample-by-sample adjustment of affine motion prediction samples;
when the setting at the sequence level indicates that the affine motion prediction is allowed, determining two or three control point motion vectors of a target block encoded using the affine motion prediction, and generating affine prediction samples for each of subblocks in the target block by performing affine motion prediction in the unit of the subblocks using the control point motion vectors; and
when it is identified, based on the setting at the picture level, that the sample-by-sample adjustment of the affine motion prediction samples is allowed for a current picture containing the target block, modifying sample values of the affine prediction samples by compensating for motion according to a sample position in each of the subblocks based on the control point motion vectors of the target block.
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