Abstract: Devices, systems and methods related to digital video coding, and specifically, to signaling of slice types in video picture headers are described. One example method of video processing includes performing a conversion between a video including one or more video pictures including one or more slices and a bitstream of the video, wherein the bitstream conforms to a format rule, and wherein the format rule specifies that for a video picture of the one or more video pictures having all slices coded as I slices, P slice and B slice related syntax elements are omitted from a picture header for the video picture.

Abstract: A method of video processing includes performing a conversion between a current video block of a second color component of a video and a bitstream of the video using a cross-component prediction with multiple-parameter model (CCPMPM) in which samples of the current video block are predictively coded in the bitstream using a linear combination of samples of a first color component multiplied by linear coefficients and/or one or more offsets. The bitstream conforms to a format rule. The linear coefficients of the CCPMPM are determined using a first rule. The samples of the first color component are determined using a second rule.

Abstract: A method of video processing is provided. The method includes determining, for a conversion between a video comprising a video unit and a bitstream of the video, whether a first coding tool is enabled for the video unit according to a rule. The rule specifies that the first coding tool and a second coding tool are mutually exclusively enabled. The first coding tool or the second coding tool comprises a sign data hiding tool. The method also includes performing the conversion according to the determining.

Abstract: Devices, systems and methods for sub-block based prediction are described. In a representative aspect, a method for video processing includes determining a block size constrain, making a determination, based on the block size constrain, about whether or not a merge affine mode and a non-merge affine mode are allowed for a video block in a video frame, and generating a bitstream representation of the video block based on the making the determination.

Abstract: Examples of video encoding methods and apparatus and video decoding methods and apparatus are described. An example method of processing video data includes determining, for a conversion between a video block of a video and a bitstream of the video, a gradient of a prediction vector at a sub-block level for the video block according to a rule, wherein the rule specifies to use a same gradient value is assigned for all samples within a sub-block of the video block; and performing the conversion based on the determining.

Abstract: Methods, devices, and systems related to video processing are disclosed. In one example aspect, a method of video processing includes performing a conversion between a block of a current picture of a video and a coded representation of the video using an intra-subblock partitioning (ISP) mode. A prediction is determined for each sub-partition using an intra-prediction process based on samples in the current picture using the ISP mode. The block is partitioned into multiple sub-partitions including a first sub-partitions having a same top-left corner position as a top-left corner position of the block.

Abstract: A method of video processing is described. The method includes determining, for a conversion between a current video unit of a video including one or more video blocks and a bitstream representation of the video, a padding process used for padding unavailable samples during application of a cross-component adaptive loop filtering (CC-ALF) tool to at least some video blocks of the current video unit according to a rule; and performing the conversion based on the determining. The rule specifies that the padding process is also used for padding unavailable samples during application of an adaptive loop filtering (ALF) tool to one or more video blocks of the current video unit.

Abstract: A method includes performing a conversion between a video including a video picture including one or more tiles and a bitstream of the video. The video picture refers to a picture parameter set, and the picture parameter set conforms to a format rule specifying that the picture parameter set includes a list of column widths for N tile columns, where N is an integer. An (N?1)-th tile column exists in the video picture and the (N?1)-th tile column has a width that is equal to an (N?1)-th entry in a list of explicitly included tile column widths plus one number of coding tree blocks.

Abstract: An example method of video processing includes performing a conversion between a picture of a video and a bitstream representation of the video. The picture includes one or more sub-pictures, and the bitstream representation conforms to a format rule that specifies that a length of a syntax element is equal to Ceil(Log 2(SS)) bits. SS is greater than 0, and the syntax element indicating a horizontal or a vertical position of a top-left corner of a coding tree unit of a sub-picture of the picture.

Abstract: Devices, systems and methods for encoding and decoding digital video using a look-up tables (LUTs) containing motion candidates are described. In a representative aspect, a method of video processing includes maintaining one or more tables, wherein at least one table of the one or more tables is associated with one or more entries, deriving, based on a first set of motion candidates in the at least one table, a second set of motion candidates, and performing, based on the second set of motion candidates, a conversion between a current block of a video and a bitstream representation of the video.

Abstract: A fusion method of satellite-based and ground-based lightning data includes S1, selecting valid data in the satellite-based and ground-based lightning data; S2, determining a time threshold for fusing the satellite-based and ground-based lightning data; S3, determining a spatial threshold for fusing the satellite-based lightning data and the ground-based lightning data; and S4, constructing a data fusion scheme to obtain a fused all lightning data set.

Abstract: A method of video decoding includes checking one or more video blocks in pre-defined relative positions compared to a first video block to derive a first set of candidates, wherein each of the first set of candidates is derived from corresponding motion information of the video blocks checked, checking, upon a determination that a number of the first set of candidates has not reached a predetermined limit, one or multiple tables to derive a second set of candidates, and processing the first video block based on a bitstream representation of the first video block and the constructed candidate list.

Abstract: An exemplary method for visual media processing includes performing a conversion between a current video block of a visual media data and a bitstream representation of the visual media data in accordance with a conditional signaling rule. The current video block is disabled from using an intra sub-block partitioning (ISP) split mode which divides the current video block into sub-blocks depending on dimensions of the current video block. In case that the conversion is associated with disabling use of the ISP split mode, the conditional signaling rule specifies selectively including in the bitstream representation a first syntax element indicating that a luma component of a sub-block of the current video block includes non-zero coefficient values. The selectively including is based at least on one or more other syntax elements having non-zero coefficient values of one or more previous sub-blocks included in the bitstream representation.

Abstract: Devices, systems and methods for applying intra-block copy (IBC) in video coding are described. In general, methods for integrating IBC with existing motion compensation algorithms for video encoding and decoding are described. In a representative aspect, a method for video encoding using IBC includes determining whether a current block of the current picture is to be encoded using a motion compensation algorithm, and encoding, based on the determining, the current block by selectively applying an intra-block copy to the current block. In a representative aspect, another method for video encoding using IBC includes determining whether a current block of the current picture is to be encoded using an intra-block copy, and encoding, based on the determining, the current block by selectively applying a motion compensation algorithm to the current block.

Abstract: Devices, systems and methods for digital video coding, which includes matrix-based intra prediction methods for video coding, are described. In one aspect, a method for video processing includes performing a conversion between a current video block of a video and a bitstream representation of the current video block using a matrix based intra prediction (MIP) mode, where the conversion includes performing the upsampling operation in which the final prediction block is determined by using a reduced prediction block of the current video block and by using reconstructed neighboring samples of the current video block according to a rule, and where the reduced prediction block is obtained by performing the matrix vector multiplication operation on reduced boundary samples of the current video block.

Abstract: Examples of video encoding methods and apparatus and video decoding methods and apparatus are described. An example method of processing video data includes determining, for a conversion between a video block of a video and a bitstream of the video, a gradient of a prediction vector at a sub-block level for the video block according to a rule, wherein the rule specifies to use a same gradient value is assigned for all samples within a sub-block of the video block; and performing the conversion based on the determining.

Abstract: A method for processing a video includes performing a determination, by a processor, that a first video block is partitioned to include a first prediction portion that is non-rectangular and non-square; adding a first motion vector (MV) prediction candidate associated with the first prediction portion to a motion candidate list associated with the first video block, wherein the first MV prediction candidate is derived from a sub-block MV prediction candidate; and performing further processing of the first video block using the motion candidate list.

Abstract: A method of visual media processing includes determining, for a conversion between a current video block of visual media data and a bitstream representation of the current video block, a buffer that stores reference samples for prediction in an intra block copy mode; for a sample spatially located at location of the current video block relative to an upper-left position of a coding tree unit including the current video block and having a block vector, computing a corresponding reference in the buffer at a reference location, wherein the reference location is determined using the block vector and the location; and upon determining that the reference location lies outside the buffer, re-computing the reference location based at least in part on a location of the current video block relative to the coding tree unit including the current video block.

Abstract: Difference calculation based on partial position is described. In a representative aspect, a method of video processing comprising: calculating, during a conversion between a current block of video and a bitstream representation of the current block, differences between two reference blocks associated with the current block or differences between two reference sub-blocks associated with a sub-block within the current block based on representative positions of the reference blocks or representative positions of the reference sub-blocks; and performing the conversion based on the differences.

Abstract: An example method of video processing includes determining, for a conversion between a block of a first sub-picture of a video and a bitstream representation of the video, whether to apply a deblocking process across an edge between the block and a neighboring block of a second sub-picture based on whether a loop filtering process is allowed across subpicture boundaries. The method also includes performing the conversion based on the determining.