Abstract: A method of video processing is described. The method includes determining, for subblocks of a current video block of a video, subblock boundaries to which a deblocking filter is to be applied according to a rule; and performing a conversion between the video and a coded representation of the video using the deblocking filter, wherein the rule specifies that a deblocking filter length is determined without checking a relationship between i) a sum of a position of a subblock of the current video block and a predefined value and ii) a width or a height of the current video block.

Abstract: A method for video processing is provided. The method includes determining, for a conversion between a current video block of a video that is a chroma block and a coded representation of the video, parameters of a cross-component linear model that are completely determinable by two chroma samples and corresponding two luma samples; and performing the conversion based on the determining.

Abstract: Video coding and decoding in which the bitstream is generated using affine motion compensation mode are described. One example includes generating, for a reconstruction of a current video unit, a list of affine motion vector prediction candidates in which each candidate in the list is calculated without using a clipping operation, wherein the clipping operation limits a magnitude of the candidate motion vectors to a range; and performing the reconstruction of the current video unit using the list of affine motion vector prediction candidates.

Abstract: A method for visual media processing, including: computing, during a conversion between a current video block of visual media data and a bitstream representation of the current video block, a cross-component linear model (CCLM) and/or a chroma residual scaling (CRS) factor for the current video block based, at least in part, on neighboring samples of a corresponding luma block which covers a top-left sample of a collocated luma block associated with the current video block, wherein one or more characteristics of the current video block are used for identifying the corresponding luma block.

Abstract: Devices, systems and methods for digital video coding, which includes in-loop reshaping for video coding, are described. An exemplary method for video processing includes performing a conversion between a video comprising one or more video data units and a bitstream representation of the video, the bitstream representation conforming to a format rule that specifies an inclusion of side information indicative of default parameters for a coding mode that is applicable to a video block of the one or more video data units for which the coding mode is enabled, and the side information providing parameters for constructing the video block based on a representation of the video block in an original domain and a reshaped domain and/or a luma-dependent scaling of a chroma residue of a chroma video block.

Abstract: Devices, systems and methods for digital video coding, which include sub-block based inter prediction methods, are described. An exemplary method for video processing includes determining, for a conversion between a current block of video and a bitstream representation of the video, a maximum number of candidates in a sub-block based merge candidate list and/or whether to add sub-block based temporal motion vector prediction (SbTMVP) candidates to the sub-block based merge candidate list based on whether temporal motion vector prediction (TMVP) is enabled for use during the conversion or whether a current picture referencing (CPR) coding mode is used for the conversion, and performing, based on the determining, the conversion.

Abstract: Video coding and decoding in which the bitstream is generated using affine motion compensation mode are described. One example includes generating, for a reconstruction of a current video unit, a list of affine motion vector prediction candidates in which each candidate in the list is calculated without using a clipping operation, wherein the clipping operation limits a magnitude of the candidate motion vectors to a range; and performing the reconstruction of the current video unit using the list of affine motion vector prediction candidates.

Abstract: A method for visual media processing, including performing a conversion between a current chroma chroma block of visual media data and a bitstream representation of the current chroma chroma block, wherein, during the conversion, a chroma residual of the current chroma chroma block is scaled based on a scaling coefficient, wherein the scaling coefficient is derived at least based on luma samples located in predefined positions.

Abstract: Devices, systems and methods for digital video coding, which includes matrix-based intra prediction methods for video coding, are described. In a representative aspect, a method for video processing includes performing a first determination that a luma video block of a video is coded using a matrix based intra prediction (MIP) mode in which a prediction block of the luma video block is determined by performing, on previously coded samples of the video, a boundary downsampling operation, followed by a matrix vector multiplication operation, and selectively followed by an upsampling operation, performing, based on the first determination, a second determination about a chroma intra mode to be used for a chroma video block associated with the luma video block, and performing, based on the second determination, a conversion between the chroma video block and a bitstream representation of the chroma video block.

Abstract: Devices, systems and methods for digital video coding, which include geometric partitioning, are described. An exemplary method for video processing includes making a decision, based on a priority rule, regarding an order of insertion of motion candidates into a motion candidate list for a conversion between a current block of video and a bitstream representation of the video, wherein the current block is coded using a geometry partition mode; and performing, based on the decision and the motion candidate list, the conversion.

Abstract: An example method of video processing includes performing a conversion between a block of a chroma component of a video and a bitstream representation of the video using a partitioning mode coding tool in which a final prediction of the chroma block is determined by blending predictions of the chroma block using weights that are based on the partitions. During the conversion, the weights are determined based on a type of chroma sample locations in the chroma component of the block.

Abstract: A method of video processing includes determining, for a conversion between a current block of a video and a coded representation of the video, that a resolution of a current picture containing the current block and a reference picture used for the conversion are different, and performing the conversion based on the determining such that predicted values of a group of samples of the current block are generated using a horizontal or a vertical interpolation filter.

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, and wherein 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: Devices, systems and methods for the simplification of sub-block motion candidate lists for video coding are described. In a representative aspect, a method for video processing includes determining, during a conversion between a current block and a bitstream representation of the current block, a temporal motion vector prediction candidate for a sub-block of the current block. The temporal motion vector prediction candidate is completely determined based on K neighboring blocks of the current block, K being a positive integer. The method also includes performing the conversion based on the temporal motion vector prediction candidate for the sub-block.

Abstract: A method of video processing includes making a determination, fora conversion between a current video block of a video and a coded representation of the video, of an affine merge candidate selectively according to a rule; and performing the conversion according to the determination. The rule specifies how the affine merge candidate is calculated without use of a log 2(X) operation where X is equal to or less than zero. The affine merge candidate is a motion candidate derived from neighboring affine coded video blocks.

Abstract: Embodiments of the present disclosure relates to constraints for usage of updated motion information. A method for video processing is provided, including: determining original motion information associated with a current block; generating updated motion information based on specific prediction mode; and performing, based on the updated motion information, a conversion between the current block and a bitstream representation of a video data including the current block, wherein the specific prediction mode includes one or more of bi-directional optical flow (BIO) refinement, a decoder-side motion vector refinement (DMVR), frame-rate up conversion (FRUC) techniques or a template matching technique.

Abstract: Symmetric motion vector difference coding is described. One example video processing method includes determining, for a conversion between a block of a current picture of video and a bitstream representation of the block, whether a symmetric motion vector difference (SMVD) mode is allowable for the block, wherein whether the SMVD mode is allowable depends on a derivation process of two target reference pictures of the current picture, which includes a first step for searching a forward target reference picture in the reference picture list 0 and searching a backward target reference picture in the reference picture list 1, and a second step for searching a backward target reference picture in the reference picture list 0 and searching a forward target reference picture in the reference picture list 1, outputs of the first step and the second step being independent of each other; and performing the conversion based on the determination.

Abstract: A method of video processing includes determining, for a conversion between a video region of a video and a bitstream representation of the video, to correct chroma samples of the video region using a cross-component adaptive loop filter (CC-ALF) process based on filtering of luma sample differences; and performing the conversion based on the determining.

Abstract: An example method of video processing includes determining, for a conversion between a chroma block of a video and a bitstream representation of the video, applicability of a deblocking filter process to at least some samples at an edge of the chroma block based on a mode of joint coding of chroma residuals for the chroma block. The method also includes performing the conversion based on the determining.

Abstract: A method of video processing includes making a determination for a conversion between a video region of a video and a bitstream representation of the video to use a cross-component adaptive loop filtering (CC-ALF) tool for refining chroma samples values using luma sample values; and performing the conversion based on the determination, wherein the refining includes correcting the chroma sample values using a final refinement that is a further refinement of a first refinement value determined by selectively filtering the luma sample values.