Abstract: Disclosed and systems, methods and devices for video processing. An exemplary method for video processing includes: determining for a current video block, an indication which indicates that an affine merge with motion vector difference (MMVD) mode is applied to the current video block; performing a conversion between the current video block and a bitstream representation of a current video block based on the indication, the indication being activated based on the usage of at least one merge list for the current video block.

Abstract: A method of visual media processing includes determining a size of a buffer to store reference samples for prediction in an intra block copy mode; and performing a conversion between a current video block of visual media data and a bitstream of the current video block, using the reference samples stored in the buffer, wherein the conversion is performed in the intra block copy mode which is based on motion information related to a reconstructed block located in same video region with the current video block without referring to a reference picture.

Abstract: A method for video processing includes performing a conversion between a current video block of a video region of a video and a coded representation of the video. The conversion uses a coding mode in which the current video block is constructed based on a first domain and a second domain and/or chroma residue is scaled in a luma-dependent manner. A parameter set in the coded representation comprises parameter information for the coding mode.

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: Devices, systems and methods for sample refinement and filtering method for video coding are described. In an exemplary aspect, a method for video processing includes modifying for a conversion between a block of a video and a bitstream representation of the video, a refinement value for a prediction sample in the block by applying a clipping operation to refinement value. The refinement value is derived based on a gradient value of an optical flow coding process. An output of the clipping operation is within a range. The method also includes refining the prediction sample based on the refinement value and performing the conversion based on the refined prediction sample.

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: Techniques for implementing video processing techniques are described. In one example implementation, a method of video processing includes determining, for a conversion between a current block of a video and a bitstream representation of the video, whether a combined inter and intra prediction (CIIP) coding technique is to be applied to the current block based on a characteristic of the current block. The CIIP coding technique uses an intermedia inter prediction value and an intermedia intra prediction value to derive a final prediction value of the current block. The method also includes performing the conversion based on the determining.

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: 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: History-based affine parameters inheritance is described. In an exemplary aspect, a method for video processing includes deriving, for a conversion between a current block of video and a bitstream representation of the current block, affine related information associated with an affine model to be used by the current block based on affine related information associated with an affine model used by a first block stored in a buffer, wherein the first block is affine coded prior to the current block; and performing the conversion by using the derived affine related information.

Abstract: Methods, systems, and devices for coefficient scaling for high-precision image and video coding are described. An example method of video processing includes performing a conversion between a current block of a video and a bitstream representation of the video according to a rule. The rule specifies that the conversion includes during encoding, skipping applying a forward transform to residual coefficients of the current block prior to including in the bitstream representation, or during decoding, reconstructing residual coefficients of the current block from the bitstream representation without applying an inverse transform. The rule further specifies that a scale factor is applied to the residual coefficients independent of a size of the current block.

Abstract: Devices, systems and methods for video processing are described. An example method for video processing includes determining, for a conversion between a current block of a video and a bitstream representation of the video, a number of intra-coded neighboring blocks of the current block for a combined inter and intra prediction mode according to a rule that specifies a manner of treating a block coded using a palette coding mode in counting the number of intra-coded neighboring blocks for the combined inter and intra prediction mode. The method also includes performing the conversion based on the determining.

Abstract: Devices, systems, and methods for palette mode coding are described. An exemplary method for video processing includes performing a conversion between a block of a video and a bitstream representation of the video. The bitstream representation is processed according to a format rule that specifies a first indication of usage of a palette mode and a second indication of usage of an intra block copy (IBC) mode are signaled dependent of each other.

Abstract: A method of video processing includes determining a refined prediction sample P?(x,y) at a position (x,y) in a video block by modifying a prediction sample P(x,y) at the position (x,y) with a first gradient component Gx(x, y) in a first direction estimated at the position (x,y) and a second gradient component Gy(x, y) in a second direction estimated at the position (x,y) and a first motion displacement Vx(x,y) estimated for the position (x,y) and a second motion displacement Vy(x,y) estimated for the position (x,y), where x and y are integer numbers, and performing a conversion between the video block and a bitstream representation of the video block using a reconstructed sample value Rec(x,y) at the position (x,y) that is obtained based on the refined prediction sample P?(x,y) and a residue sample value Res(x,y).

Abstract: A method of video processing is described. The method includes: deriving, for a conversion between a current block of a video and a coded representation 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 using the prediction block; wherein the deriving includes: applying the weights to two intermediate prediction samples that respectively belong to the two initial prediction blocks to derive a final prediction sample; and performing a right shift operation for the final prediction sample, wherein the right shift operation is pbSample>> (shift1+3)), wherein pbSample represents the final prediction sample, shift1 is set equal to Max(2, 14?bitDepth); and determining the prediction block based on the final prediction sample.

Abstract: A method for processing a video includes performing a conversion between a current block of visual media data and a corresponding coded representation of the visual media data. The conversion of the current block includes determining whether a use of one or both of a bi-directional optical flow (BIO) technique or a decoder-side motion vector refinement (DMVR) technique to the current block is enabled or disabled. Determining the use of the BIO technique or the DMVR technique is based on a cost criterion associated with the current block.

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: 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: 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: Techniques for implementing video processing techniques are described. In one example implementation, a method of video processing includes determining, for a conversion between a current block of a video coded using a combined inter and intra prediction (CIIP) coding technique and a bitstream representation of the video, an intra-prediction mode of the current block independently from an intra-prediction mode of a neighboring block. The CIIP coding technique uses an intermedia inter prediction value and an intermedia intra prediction value to derive a final prediction value of the current block. The method also includes performing the conversion based on the determining.