US 12,425,585 B2
Classification in adaptive loop filtering
Li Zhang, San Diego, CA (US); Kai 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 Feb. 27, 2023, as Appl. No. 18/174,961.
Application 18/174,961 is a continuation of application No. 17/575,754, filed on Jan. 14, 2022, granted, now 11,700,368.
Application 17/575,754 is a continuation of application No. PCT/CN2020/102003, filed on Jul. 15, 2020.
Claims priority of application No. PCT/CN2019/096059 (WO), filed on Jul. 15, 2019; and application No. PCT/CN2019/096398 (WO), filed on Jul. 17, 2019.
Prior Publication US 2023/0231998 A1, Jul. 20, 2023
This patent is subject to a terminal disclaimer.
Int. Cl. H04N 19/117 (2014.01); H04N 19/13 (2014.01); H04N 19/176 (2014.01); H04N 19/96 (2014.01); H04N 19/98 (2014.01)
CPC H04N 19/117 (2014.11) [H04N 19/13 (2014.11); H04N 19/176 (2014.11); H04N 19/96 (2014.11); H04N 19/98 (2014.11)] 18 Claims
OG exemplary drawing
 
1. A method of processing video data, comprising:
determining, for a conversion between a picture in a video comprising one or more coding tree blocks and a bitstream of the video, gradients of a subset of samples in a region with a dimension of 8×8 for deriving a classification of a 4×4 block of a first coding tree block in an adaptive loop filtering process, wherein the 4×4 block is located within the first coding tree block and the 8×8 region is centered at the 4×4 block and the 8×8 region is located within a 10×10 region; and
performing the conversion based on the determining,
wherein the adaptive loop filtering process comprises:
determining a filtering coefficient set for a sample of the 4×4 block based on the gradients;
determining a clipping value set for the sample; and
applying a filter on the sample based on the filtering coefficient set and the clipping value set,
wherein in case it is disallowed to use samples across a boundary of a video unit in the adaptive loop filtering process, left-most two columns of samples in the 8×8 region are padded when there is a sample in the 4×4 block located at a left boundary of the video unit, and left-most three columns of samples in the 10×10 region including the two columns of samples in the 8×8 region are padded when there is a sample in the 4×4 block located at a left boundary of the video unit,
wherein the boundary of the video unit comprises a slice boundary or a tile boundary, and
wherein separate syntax elements indicating whether samples across different kinds of boundaries are allowed to be used are signaled at different levels, and wherein the different kinds of boundaries comprise the slice boundary, the tile boundary and a sub-picture boundary.