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 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: Methods, systems, and devices for performing entropy coding for a palette escape symbol in palette mode coding and decoding are described. An example method for video processing includes performing a conversion between a video having one or more video regions including a current video block and a bitstream representation of the video, wherein the bitstream representation conforms to a format rule that the current video block is coded using a palette mode coding tool, wherein a binarization of an escape symbol for the current video block uses an exponential-Golomb (EG) code of order K, wherein K is a non-negative integer that is unequal to three, and wherein the palette mode coding tool represents the current video block using a palette of representative color values and wherein the escape symbol is used for a sample of the current video block coded without using the representative color values.

Abstract: Methods and apparatus for video processing are disclosed. The processing may include video encoding, video decoding, or video transcoding. One example method includes performing a conversion between a current block of a video and a bitstream of the video. The bitstream conforms to a rule that specifies that a context index offset is used for including a first sign flag of a first coefficient in the bitstream. The rule specifies that a value of the context index offset is based on whether a first coding mode is applied on the current block in the bitstream.

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.

Abstract: In an exemplary aspect, a method for visual media processing includes identifying a boundary at a vertical edge and/or a horizontal edge of two video blocks; calculating a boundary strength of a filter based on at least one of the two video blocks crossing a vertical edge or a horizontal edge is coded using a combined intra-inter prediction (CIIP) mode; deciding whether to turn on or off the filter; selecting a strength of the filter in case the filter is turned on; and performing, based on the selecting, a deblocking filter (DB) process to the video blocks.

Abstract: Methods, systems, and devices for quantization parameter derivation in palette mode coding and decoding 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, that the current block is coded using a palette mode and an escape symbol value is signaled in the bitstream representation, and performing, based on the determining, the conversion, wherein a clipped quantization parameter for the current block is used in the conversion, and wherein the clipped quantization parameter used for a chroma component of the video is derived based on a quantization parameter subsequent to a mapping operation of a quantization process or a dequantization process.

Abstract: A method of video processing is described. The method includes performing a conversion between a current video block of a video and a coded representation of the current video block according to a rule, wherein the rule specifies that, due to use of an identity transform coding tool for representing the current video block into the coded representation, a syntax field indicative of a quantization parameter used for decoding the current video block is included such that a value of the quantization parameter is modified according to a rule, wherein the identity transform coding tool allows coefficient values at a transform domain of the current block to be same as values of a residual block of the current video block.

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: Devices, systems and methods for palette mode coding are described. An exemplary method for video processing includes determining, for a conversion between a block of a video region in a video and a bitstream representation of the video, a prediction mode based on one or more allowed prediction modes that include at least a palette mode of the block. An indication of usage of the palette mode is determined according to the prediction mode. The method also includes performing the conversion based on the one or more allowed prediction modes.

Abstract: A method of visual media processing video, includes determining that palette mode is to be used for processing a first portion of a video block and intra block copy (IBC) mode is to be used for processing a second portion of the video block, and performing further processing of the first portion of the video block using the palette mode and the second portion of the video using the IBC mode, wherein indications of the first portion of the video block processed using the palette mode and indications of the second portion of the video block processed using the IBC mode are included in a palette index identifying the first portion of the video block and the second portion of the video block.

Abstract: A method of video processing is provided. The method includes determining, due to a dual tree partitioning structure being used for a conversion between a video unit and a coded representation of the video unit, that use of an adaptive color space transformation (ACT) tool is disabled for the video unit; and performing, based on the determining, the conversion by disabling the ACT tool for the video unit, wherein the use of the ACT tool comprises: converting, during encoding a representation of a visual signal from a first color domain to a second color domain, or converting during decoding, a representation of a visual signal from the second color domain to the first color domain.

Abstract: A method includes deriving, for a current video block of a video that is a chroma block and coded in a chroma derived mode (DM), an intra prediction mode for the current video block according to a rule related to a coding mode of the current video block; and performing a conversion between the current video block and a coded presentation of the video, wherein the rule specifies to derive the intra prediction mode based on an intra prediction direction of a corresponding luma block used to derive the chroma DM mode and coded using a block differential pulse code modulation representation of a quantized residual block corresponding to the current video block.

Abstract: A method includes performing a conversion between a block of a video and a bitstream of the video according to a rule. The rule specifies that whether a syntax element identifying a deblocking offset for a chroma component of the video is included in a video region level is determined based on a colour format of the video.

Abstract: Methods, systems, and devices for using palette mode with different partition structures are described. An example method for video processing includes maintaining, for a conversion between a video comprising one or more video regions comprising a current video block and a bitstream representation of the video, a palette prediction table for a prediction of a palette used in a palette mode coding tool used for the current video block, making a determination that a local dual tree coding is applied to the conversion, modifying, based on the determination, the palette prediction table, and performing, based on the palette prediction table subsequent to the modifying, the conversion, wherein the palette mode coding tool represents the current video block using a palette of representative color values, and wherein the local dual tree coding enables partitioning of chroma blocks independently from corresponding luma blocks based on a block size.

Abstract: Video processing methods, systems and appratrus are described. One example method includes performing a conversion between a video block of a video and a bitstream of the video using a palette mode in which samples of the video block are represented using a palette of representive color values. A size of the palette of the video block is determined based on whether a local dual tree is applied for the conversion.

Abstract: A method of video processing comprises performing a conversion between a video unit of a video and a bitstream of the video according to a rule, wherein the rule specifies that whether a cross-component adaptive loop filter (CC-ALF) mode and an adaptive loop filter (ALF) mode are enabled for coding the video unit are indicated in the bitstream in a mutually independent manner.

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.