US 12,452,405 B2
Handling of bi-directional optical flow (BIO) coding tool for reference picture resampling in video coding
Jianle Chen, San Diego, CA (US); FNU Hendry, San Diego, CA (US); and Ye-Kui Wang, San Diego, CA (US)
Assigned to Huawei Technologies Co., Ltd., Shenzhen (CN)
Filed by Huawei Technologies Co., Ltd., Shenzhen (CN)
Filed on Sep. 24, 2021, as Appl. No. 17/484,796.
Application 17/484,796 is a continuation of application No. PCT/US2020/032922, filed on May 14, 2020.
Claims priority of provisional application 62/848,409, filed on May 15, 2019.
Prior Publication US 2022/0014735 A1, Jan. 13, 2022
Int. Cl. H04N 19/105 (2014.01); H04N 19/132 (2014.01); H04N 19/159 (2014.01); H04N 19/176 (2014.01); H04N 19/46 (2014.01); H04N 19/513 (2014.01)
CPC H04N 19/105 (2014.11) [H04N 19/132 (2014.11); H04N 19/159 (2014.11); H04N 19/176 (2014.11); H04N 19/46 (2014.11); H04N 19/513 (2014.11)] 21 Claims
OG exemplary drawing
 
1. A method of decoding implemented by a video decoder, comprising:
determining whether a resolution of a current picture being decoded is the same as a resolution of reference pictures identified by a reference picture list associated with the current picture;
enabling bi-direction optical flow (BDOF) for a current block of the current picture when the resolution of the current picture is determined to be the same as the resolution of each of the reference pictures, a motion model index (MotionModelIdc) of the current block is equal to zero, a merge subblock flag is equal to zero, and at least one flag outside a sequence parameter set and a derived BDOF variable each have a value specifying that the BDOF is enabled;
disabling the BDOF for the current block of the current picture based at least on the flag outside the sequence parameter set or when the resolution of the current picture is determined to be different than the resolution of either of the reference pictures; and
refining motion vectors corresponding to the current block using the BDOF when the BDOF is enabled for the current block.