Abstract: Example implementations include a method, apparatus and computer-readable medium of video coding, comprising performing a conversion between a video comprising a plurality of pictures and a bitstream of the video, wherein each picture comprises an alpha layer and at least one base layer, and wherein the bitstream comprises first layer information which is utilized in a first process performed on the at least one base layer and second layer information which is utilized in a second process performed on the alpha layer.

Abstract: Example implementations include a method, apparatus and computer-readable medium of video coding, comprising performing a conversion between a video comprising a plurality of pictures and a bitstream of the video, wherein each picture comprises an alpha layer and a base layer, and wherein the bitstream comprises a current block in the alpha layer of a current picture that is predicted from one or more reference blocks in the base layer.

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 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: Example implementations include a method, apparatus and computer-readable medium of video coding, comprising determining, for a conversion between a video comprising a plurality of pictures and a bitstream of the video, first layer information which is utilized in a first process performed on a first layer of each picture. The implementations further include determining, second layer information which is utilized in a second process performed on a second layer of each picture. Additionally, the implementations further include performing the conversion for the second layer based on the first layer information and the second layer information.

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. 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: 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.

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: 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: 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 example method of video processing includes making a determination, for a conversion between a current video block of a video and a bitstream representation of the video, whether a cross-component adaptive loop filtering tool is enabled for the current video block based on a color property of the video. The method also includes performing the conversion according to 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: Methods, systems, and devices for performing entropy coding for the palette escape symbol in palette mode coding and decoding are described. An example method for video processing includes performing a conversion between a video comprising one or more video regions comprising 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: An example method of video processing includes determining, for a conversion between a current block of a video and a bitstream representation of the video, whether to enable usage of a chroma quantization parameter (QP) offset for the current block according to a syntax element at a level of a video unit. The video unit includes the current block and a second block of the video. The method also includes performing the conversion based on the determining.

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. During the conversion, a deblocking filter process is applied to at least some samples along an edge of the block, and wherein chroma quantization parameter (QP) offsets are added to outputs from a chroma QP table to determine parameters for the deblocking filter process.

Abstract: In one example aspect, a method of video processing includes performing a conversion between a current block of a video and a bitstream of the video using a palette mode in which a palette of representative sample values is used for coding the current block. During the conversion, one or multiple predictor palettes are used for predicting the palette of representative sample values, and wherein updating of the one or multiple predictor palettes after the conversion of the current block is disabled according to a rule based on a characteristic of the current block.

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.