Abstract: Devices, systems and methods for transform design for large blocks in video coding are described. An exemplary method for video processing includes determining that a size of a residual block of a video is larger than a maximum block size allowed for a transform skip mode, in which, during a decoding operation, residual coefficients are decoded without performing an inverse transform operation; splitting, based on the size of a residual block, the residual block into multiple regions, wherein each region represents a portion of the residual block of a difference between a portion of a current video block and a prediction block corresponding to the portion of the current video block; and determining a reconstructed current video block from the residual block based on selectively performing the inverse transform operation according to an indicator that indicates the transform skip mode.

Abstract: In an exemplary aspect, a method for visual media processing includes determining whether a pair of adjacent blocks of visual media data are both intra block copy (IBC) coded; and selectively applying, based on the determination, a deblocking filter (DB) process by identifying a boundary at a vertical edge and/or a horizontal edge of the pair of adjacent blocks, calculating a boundary strength of a filter, deciding whether to turn on or off the filter, and selecting a strength of the filter in case the filter is turned on, wherein the boundary strength of the filter is dependent on a motion vector difference between motion vectors associated with the pair of adjacent blocks.

Abstract: A method for processing video data is described and the method includes: deriving, for a conversion between a video processing unit of the video and a bitstream of the video processing unit, at least one deblocking filter associated with a chroma deblocking filter process of the video processing unit; applying a same deblocking filter from the at least one deblocking filter for all chroma components of the video processing unit; and performing the conversion based on the same deblocking filter.

Abstract: Systems and methods for applying deblocking filters to reconstructed video data are disclosed. Sample values in adjacent reconstructed video blocks are modified according to multiple passes of a deblocking filter. A filtering pass may correspond to processing or constructing of all or subset of samples to be deblocked. The number of processing or constructing for each sample in a given pass may correspond to the pass index or order.

Abstract: A method for determining a partitioning of video data for video coding is provided. A coding unit is determined from a picture of the video data. The coding unit is determined as a fractional boundary coding unit when the coding unit has only a portion within a boundary of the picture. A subset of partitioning modes is available for partitioning the fractional boundary coding unit and includes quadtree splitting and symmetric binary tree splitting partitioning modes. When the coding unit is the fractional boundary coding unit, the method determines whether one of a block height and a block width of the coding unit is greater than a corresponding one of threshold values. A determination of the partitioning includes determining whether one of symmetric binary tree splittings is allowed for the coding unit based on the one of the block height and the block width and the corresponding threshold value.

Abstract: A video processing method is described. The method includes determining, for a conversion between a video unit of a video and a coded representation of the video, a maximum number of entries of a palette of representative values used during the conversion according to a rule; and performing the conversion using the palette, and wherein the rule specifies the maximum number of entries according to a characteristic of the video unit.

Abstract: Devices, systems and methods for coefficient coding in transform skip mode are described. An exemplary method for visual media processing includes making a decision, for encoding a current video block in a video region of a visual media data into a bitstream representation of the visual media data, regarding an application of an intra block copy (IBC) mode based on or inferred from at least a coding tree structure associated with the current video block; and selectively including, in the bitstream representation, a syntax element indicative of the application of the IBC mode based on or inferred from at least the coding tree structure.

Abstract: Video coding and decoding methods are described. In example method includes performing a conversion between a current video block of a video and a bitstream representation of the current video block by determining a first intra coding mode to be stored which is associated with the current video block using a differential coding mode, where the first intra coding mode associated with the current video block is determined according to a second prediction mode used by the differential coding mode, and where, in the differential coding mode, a difference between a quantized residual of an intra prediction of the current video block and a prediction of the quantized residual is represented in the bitstream representation for the current video block using a differential pulse coding modulation (DPCM) representation.

Abstract: Systems and methods for performing motion vector prediction for video coding are disclosed. A motion vector predictor is determined based at least in part on motion information associated with a selected motion vector predictor origin and offset values corresponding to a selected sampling point. The sampling point is specified according to a set of direction and distance on a sampling map for the motion vector predictor origin.

Abstract: A method for video processing includes determining, based on a first indication, whether a sub-block residual coding scheme is applied to residual of a current video block in a transform skip mode, the sub-block residual coding scheme splitting the residual of the current video block into multiple sub-blocks and a subset of the multiple sub-blocks have non-zero coefficients; determining, based on a second indication, a specific split pattern to be applied to the residual of the current video block, in response to the sub-block residual coding scheme being applied to the residual of the current video block; deriving, based on a third indication, the subset of the multiple sub-blocks which have non-zero coefficients; and performing a conversion on the residue of the current video block based on the determined subset of sub-blocks having non-zero coefficients.

Abstract: Devices, systems and methods for coefficient coding in transform skip mode are described. An exemplary method for visual media processing includes: for encoding a current video block in a video region of a visual media data into a bitstream representation of the visual media data, identifying usage of a coding mode and/or an intra prediction mode and/or a set of allowable intra prediction modes; and upon identifying the usage, making a decision of whether to include or exclude, in the bitstream representation, a syntax element indicative of selectively applying a transform skip mode to the current video block, wherein, in the transform skip mode, a residual of a prediction error between the current video block and a reference video block is represented in the bitstream representation of the visual media data without applying a transformation.

Abstract: A method for video processing includes applying a sub-block residual coding scheme to a current video block, wherein the residual of the current video block is split into a plurality of sub-blocks each having a size of M*N, determining at least one sub-block with non-zero coefficients based on characteristic associated with each of the plurality of sub-blocks; coding the residue of the current video block based on the derived at least one sub-block with non-zero coefficients.

Abstract: A video coding device may be configured to perform video coding according to one or more of the techniques described herein.

Abstract: Systems and methods for applying deblocking filters to reconstructed video data are disclosed. Sample values in adjacent reconstructed video blocks are modified according to multiple passes of a deblocking filter. A filtering pass may correspond to processing or constructing of all or subset of samples to be deblocked. The number of processing or constructing for each sample in a given pass may correspond to the pass index or order.

Abstract: Motion Vector Management for Decoder Side Motion Vector Refinement is disclosed. A method of video processing including: determining, for a conversion between a first block of video and a bitstream representation of the first block of video, whether and/or how to apply decoder-side motion vector refinement (DMVR) based on a signaled information; and performing the conversion based on the determination.

Abstract: Video coding and decoding methods are described. In example method includes determining that a differential coding mode is applicable to a conversion between a current video block of a video and a bitstream representation of the current video block, and performing, based on the determining, the conversion between the current video block and the bitstream representation of the current video block using the differential coding mode according to an implementation rule, where, in the differential coding mode, the current video block is represented in the bitstream representation using a difference between a quantized residual of an intra prediction of the current video block and a prediction of the quantized residual, and where, in the differential coding mode, the difference between the quantized residual and the prediction of the quantized residual is represented using a differential pulse coding modulation (DPCM) representation.

Abstract: Video coding and decoding methods are described. An example method includes determining, based on an applicability rule, that a differential coding mode is applicable to a conversion between a chroma video block of a video and a bitstream representation of the chroma video block, and performing, based on the determining, the conversion between the chroma video block and the bitstream representation of the chroma video block using the differential coding mode, where the chroma video block is represented in the bitstream representation using a difference between a quantized residual of an intra prediction of the chroma video block and a prediction of the quantized residual in the differential coding mode, where the intra prediction is performed in a first direction and the prediction of the quantized residual is performed in a second direction, and where the difference is represented using a differential pulse coding modulation (DPCM) representation.

Abstract: Devices, systems and methods for coefficient coding in transform skip mode are described. An exemplary method for video processing includes determining, for encoding one or more video blocks in a video region of a visual media data into a bitstream representation of the visual media data, a maximum allowed dimension up to which a current video block of the one or more video blocks is allowed to be encoded using a transform skip mode such that a residual of a prediction error between the current video block and a reference video block is represented in the bitstream representation without applying a transform; and including a syntax element indicative of the maximum allowed dimension in the bitstream representation.

Abstract: Methods, systems and device for hash-based motion estimation in video coding are described. An exemplary method of video processing includes determining, for a conversion between a current block of a video and a bitstream representation of the video, motion information associated with the current block using a hash-based motion search, a size of the current block being M×N, M and N being positive integers and M being not equal to N, applying, based on the motion information and a video picture comprising the current block, a prediction for the current block, and performing, based on the prediction, the conversion.

Abstract: Methods, systems and device for hash-based motion estimation in video coding are described. An exemplary method of video processing includes determining, for a conversion between a current block of a video and a bitstream representation of the video, motion information associated with the current block using a hash-based motion search, a size of the current block being M×N, M and N being positive integers and M being not equal to N, applying, based on the motion information and a video picture comprising the current block, a prediction for the current block, and performing, based on the prediction, the conversion.