US 11,973,931 B2
Weighted sample bi-prediction in video coding
Yang Wang, Beijing (CN); Hongbin Liu, Beijing (CN); Li Zhang, San Diego, CA (US); Kai Zhang, San Diego, CA (US); Jizheng Xu, San Diego, CA (US); 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 Mar. 10, 2022, as Appl. No. 17/691,910.
Application 17/691,910 is a continuation of application No. PCT/CN2020/114761, filed on Sep. 11, 2020.
Claims priority of application No. PCT/CN2019/105825 (WO), filed on Sep. 13, 2019.
Prior Publication US 2022/0201310 A1, Jun. 23, 2022
Int. Cl. H04N 19/132 (2014.01); H04N 19/103 (2014.01); H04N 19/105 (2014.01); H04N 19/137 (2014.01); H04N 19/159 (2014.01); H04N 19/176 (2014.01); H04N 19/184 (2014.01); H04N 19/186 (2014.01); H04N 19/46 (2014.01); H04N 19/50 (2014.01)
CPC H04N 19/103 (2014.11) [H04N 19/105 (2014.11); H04N 19/132 (2014.11); H04N 19/137 (2014.11); H04N 19/159 (2014.11); H04N 19/176 (2014.11); H04N 19/184 (2014.11); H04N 19/186 (2014.11); H04N 19/46 (2014.11); H04N 19/50 (2014.11)] 20 Claims
OG exemplary drawing
 
1. A method of processing video data, comprising:
deriving, for a conversion between a current block of a video and a bitstream of the video, a prediction block for the current block that is determined according to a tool in which weights are used to determine a weighted sum of two initial prediction blocks used to determine the prediction block; and
performing the conversion based on the prediction block,
wherein the deriving of the prediction block comprises:
applying weights to two intermediate prediction samples that are respectively in the two initial prediction blocks to derive a weighted prediction sample;
performing a right shift operation on the weighted prediction sample, wherein a value of the right shift operation is (shift1+3), wherein shift1 is set equal to Max(2, 14−bitDepth), in which bitDepth represents a sample bit depth; and
determining the prediction block based on the weighted prediction sample with the right shift operation,
wherein the method further comprises:
applying a format rule on the bitstream, wherein the format rule specifies a selective inclusion in the bitstream of an indication of a skip mode coding of the current block, wherein the skip mode coding allows to perform the conversion without generating or coding of a residual of the current block, and
wherein the format rule specifies that the indication is included in the bitstream in a case that conditions are satisfied, and the conditions consist of:
1) a slice type of a slice comprising the current block being not an I-slice, or a flag indicating whether an intra block copy (IBC) mode is enabled being set to true, wherein the flag indicating whether the intra block copy (IBC) mode is enabled represents as sps_ibc_enabled_flag, and
2) the current block being not chroma component under dual tree partition structure, and
3) i) a height and/or a width of the current block being not equal to 4 and ii) modeType of the current block being not MODE_TYPE_INTRA, or iii) the flag indicating whether the intra block copy (IBC) mode is enabled being set to true and the height and the width of the current block being less than or equal to 64;
wherein, before performing the right shift operation, an offset is added to the weighted prediction sample;
wherein, the offset is offset3=1<<(shift1+2);
wherein determining the prediction block based on the weighted prediction sample with the right shift operation comprises deriving a final prediction sample, in which pbSamples[x][y]=Clip3(0, (1<<bitDepth)−1, (w0*predSamplesL0[x][y]+w1*predSamplesL1[x][y]+offset3)>>(shift1+3)),
wherein pbSamples[x][y] represents the final prediction sample, w0 and w1 are the weights, predSamplesL0[x][y] and predSamplesL1[x][y] are the two intermediate prediction samples, w0*predSamplesL0[x][y]+w1*predSamplesL1[x][y] represents the weighted prediction sample;
wherein the format rule specifies that the selective inclusion of the indication is independent of a flag indicating whether a palette mode is enabled, wherein the flag indicating whether the palette mode is enabled represents as sps_palette_enabled_flag.