US 12,348,761 B2
Merge with motion vector differencing in affine mode
Kai Zhang, San Diego, CA (US); Li Zhang, San Diego, CA (US); Hongbin Liu, Beijing (CN); and Yue Wang, Beijing (CN)
Assigned to BEIJING BYTEDANCE NETWORK TECHNOLOGY CO., LTD., Beijing (CN); and BYTEDANCE INC., Los Angeles, CA (US)
Filed by Beijing Bytedance Network Technology Co., Ltd., Beijing (CN); and Bytedance Inc., Los Angeles, CA (US)
Filed on Jun. 2, 2022, as Appl. No. 17/831,074.
Application 17/831,074 is a continuation of application No. PCT/CN2020/133271, filed on Dec. 2, 2020.
Claims priority of application No. PCT/CN2019/122347 (WO), filed on Dec. 2, 2019.
Prior Publication US 2022/0303571 A1, Sep. 22, 2022
Int. Cl. H04N 19/517 (2014.01); H04N 19/176 (2014.01); H04N 19/70 (2014.01)
CPC H04N 19/517 (2014.11) [H04N 19/176 (2014.11); H04N 19/70 (2014.11)] 14 Claims
OG exemplary drawing
 
1. A method of visual media processing, comprising:
determining, for a conversion between a current video block of visual media data and a bitstream of the visual media data, that an affine candidate for the current video block is subject to a modification based on a modification rule; and
performing the conversion based on the determining,
wherein the modification rule specifies to modify one or more control point motion vectors associated with the current video block;
wherein modifying the one or more control point motion vectors of the affine candidate for the current video block includes adding one or more offset values to the one or more control point motion vectors, wherein each of the one or more offset values is derived by using a direction index and a distance index associated with a control point motion vector; and
wherein when an affine model of the current video block is a 6-parameter model defined using three control point motion vectors MV0, MV1 and MV2, only two control point motion vectors are to be modified, and the only two control point motion vectors to be modified are MV0 and MV1.