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.

Abstract: A video coding device may be configured to perform video coding according to one or more of the techniques described herein. In one example, a method of partitioning video data for video coding, comprises receiving a video block including sample values, and partitioning the sample values according to the following set of partitioning modes: quadtree, horizontal or vertical symmetric binary tree, horizontal or vertical asymmetric binary tree, and horizontal or vertical triple tree.

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: 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: 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: Some embodiments provide a method of decoding a current video block in a video picture. From several partitioning schemes, the method identifies a partitioning scheme that is used to partition the current video block. Based on the identified partitioning scheme, the method selects one derivation to compute a first quantization parameter for the current video block from several candidate derivations for computing the first quantization parameter. The method computes a second quantization parameter for the current video block based at least in part on the computed first quantization parameter. The method then uses the computed second quantization parameter to decode the current video block.

Abstract: Devices, systems and methods for video processing are described. An example method for video processing includes performing a conversion between a video comprising luma blocks and corresponding chroma blocks and a bitstream representation of the video according to a rule that specifies that, for a case that a current luma block is coded using a palette coding mode and a corresponding current chroma block coded with a derived mode, the current luma block is treated as having a default intra prediction mode and the current chroma block is coded with the default intra prediction mode.

Abstract: Devices, systems and methods for video processing are described. An exemplary method for video processing includes determining, for a conversion between a current block of a video and a bitstream representation of the video, that a neighboring block of the current block that is coded in a palette mode is processed as an intra-coded block having a default mode during a construction of a list of most probable modes (MPM) candidates of the current block in case the neighboring block is located above or left of the current block. 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 region of a video and a bitstream representation of the video. The bitstream representation is processed according to a first format rule that specifies whether a first indication of usage of a palette mode is signaled for the block and a second format rule that specifies a position of the first indication relative to a second indication of usage of a prediction mode for the block.

Abstract: A method of video processing includes determining, for a conversion between a video component of a video comprising a current video block and a bitstream representation of the video, that an adaptive color space transformation (ACT) tool is used based on a rule for the current video block; and performing the conversion according to the determining, and wherein the rule specifies to use a same constant quantization parameter (QP) offset for each of one or more color component of the current video block.

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: 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: An example method of video processing includes applying, in a conversion between a video comprising multiple components and a bitstream representation of the video, a deblocking filter to video blocks of the multiple components. A deblocking filter strength for the deblocking filter of each of the multiple components is determined according to a rule that specifies to use a different manner for determining the deblocking filter strength for the video blocks of each of the multiple components.

Abstract: Devices, systems and methods for video processing are described. An example method for video processing includes performing a conversion between a video comprising luma blocks and corresponding chroma blocks and a bitstream representation of the video according to a rule that specifies that, for a case that a current luma block is coded using a palette coding mode and a corresponding current chroma block coded with a derived mode, the current luma block is treated as having a default intra prediction mode and the current chroma block is coded with the default intra prediction mode.

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 that a first block coded using a first prediction mode is treated as a non-intra block to be excluded from counting of the number of intra-coded neighboring blocks. In the first prediction mode, reconstructed samples are represented by a set of representative color values, and the set of representative color values comprises at least one of 1) palette predictors, 2) escaped samples, or 3) palette information included in the bitstream. The method also includes performing the conversion based on the determining.

Abstract: A method of video processing includes performing a conversion between a portion of a chroma component of a video and a bitstream representation of the video according to a rule, wherein the rule specifies that whether a cross-component adaptive loop filtering (CC-ALF) tool is available for the conversion of the portion of the video is dependent on whether an availability or a use of an adaptive loop filtering (ALF) tool is indicated for a corresponding portion of a luma component.

Abstract: An example method of video processing includes performing a conversion between a video comprising one or more coding units and a bitstream representation of the video. The bitstream representation conforms to a format rule that specifies that chroma quantization parameters are included in the bitstream representation at a coding unit level or a transform unit level according to the format rule.

Abstract: An electronic device of decoding a current video block in a video picture is provided. The electronic device determines whether a partitioning scheme of the current video block is a single tree partitioning or a dual tree partitioning. The electronic device selects, based on the partitioning scheme, one derivation from candidate derivations to compute a first predictive quantization parameter (QP) for the current video block. A first derivation comprises computing the first predictive QP based at least in part on another QP and an additional value when the partitioning scheme is the single tree partitioning. A second derivation comprises computing the first predictive QP by using a previously-derived QP when the partitioning scheme is the dual tree partitioning. The electronic device computes a second QP based at least in part on the first predictive QP and an offset value, and use the second QP to decode the current video block.

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: Devices, systems and methods for video processing are described. An exemplary method for video processing includes determining, for a block of a video, a quantization parameter associated with the block, coding the block of the video into a bitstream representation of the video as a palette coded block in part based on a modified value of the quantization parameter, and signaling coded information related to the quantization parameter in the bitstream representation.