Abstract: Methods, systems, and devices for implementing an adaptive color transform (ACT) during image/video encoding and decoding, including: determining, for a conversion between a video including a block and a bitstream of the video, that a size of the block is greater than a maximum allowed size for an ACT mode, and performing, based on the determining, the conversion. In response to the size of the block being greater than the maximum allowed size for the ACT mode, the block is partitioned into multiple sub-blocks. Each of the multiple sub-blocks share a same prediction mode, and the ACT mode is enabled at a sub-block level.

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: 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 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: Method, device, apparatus, and computer-readable storage medium to determine whether video block is a fractional boundary video block (See paragraph [0032] and FIG. 7.) and to partition the fractional boundary video block into inferred partitions using a subset of available partition modes (See paragraph [0033] and FIG. 8.) are disclosed.

Abstract: A method of coding of video data is disclosed. According to the method, a predicted luma quantization parameter is derived and a luma quantization parameter is generated. The predicted luma quantization parameter is derived by using a tree type specifying whether a single tree or a dual tree is used to partition a coding tree. The luma quantization parameter is generated by using the predicted luma quantization parameter. The predicted luma quantization parameter is set equal to a luma quantization parameter of a coding unit containing a luma coding block covering a neighbouring location by using a current quantization group and a neighbouring block availability.

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: A method of video processing is provided. The method includes: determining, for a conversion between a current video unit of a video and a coded representation of the video, that applicability of a first coding tool and a second coding tool is mutually exclusive; and performing the conversion based on the determining, wherein the first coding tool corresponds to an adaptive color space transformation (ACT) tool; wherein 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 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: This disclosure relates to video coding and more particularly to techniques for performing deblocking of reconstructed video data. In one example, a method of filtering reconstructed video data is disclosed. The method comprises: receiving an edge type variable specifying whether a vertical or horizontal edge is filtered; deriving a maximum filter length based on the edge type variable; and performing a deblocking filtering for a current block based on the maximum filter length.

Abstract: Methods, systems and devices for implementing adaptive color transform (ACT) and block based delta pulse code modulation (BDPCM) during image/video encoding or decoding are described. An example method of video processing includes determining, for a conversion between a current video unit of a video that is a chroma video unit and a bitstream representation of the video, whether a block-based delta pulse code modulation (BDPCM) mode is available based on a rule, and performing the conversion based on the determining, wherein the rule is based on whether an adaptive color transform (ACT) mode is used for coding the current video unit and/or whether the BDPCM mode is used for coding a luma video unit corresponding to the current video unit.

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 for implementing an adaptive color transform (ACT) during image/video encoding and decoding, comprises determining, for a conversion between a video comprising a block and a bitstream of the video, that a size of the block is greater than a maximum allowed size for an ACT mode, and performing, based on the determining, the conversion, wherein, in response to the size of the block being greater than the maximum allowed size for the ACT mode, the block is partitioned into multiple sub-blocks, and wherein each of the multiple sub-blocks share a same prediction mode, and the ACT mode is enabled at a sub-block level.

Abstract: A method for implementing an adaptive colour transform (ACT) mode during image/video encoding and decoding includes performing a conversion between a current video block of a video and a bitstream of the video, wherein the current video block is coded using the ACT mode, wherein the conversion includes applying an inverse ACT transform on the current video block according to a rule, and wherein the rule specifies that a clipping operation, based on a bit depth of the current video block, is applied to an input of the inverse ACT transform.

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: 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: 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 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 implementing an adaptive color transform (ACT) during image/video encoding and decoding, including: determining, for a conversion between a video comprising a block and a bitstream of the video, that a size of the block is greater than a maximum allowed size for an ACT mode, and performing, based on the determining, the conversion, wherein, in response to the size of the block being greater than the maximum allowed size for the ACT mode, the block is partitioned into multiple sub-blocks, and wherein each of the multiple sub-blocks share a same prediction mode, and the ACT mode is enabled at a sub-block level.