Abstract: Methods, systems, and devices for luma mapping with chroma scaling for video and image coding are disclosed. An example method of video processing includes performing, for a current region comprising a luma block, a first chroma block, and a second chroma block, a conversion between the current region of a video and a bitstream representation of the video according to a rule that specifies an order in which, during decoding, the first chroma block and the second chroma block are processed based on mapped sample values of the luma block.

Abstract: A method of video processing, including performing a conversion between a video block of a video component of a video and a bitstream of the video, where the video block includes sub-blocks, where a filtering tool is used during the conversion according to a rule, and where the rule specifies that the filtering tool is applied by using a single offset for all samples of each sub-block of the video block.

Abstract: A method and a device for encoding or decoding based on an inter-frame prediction. The method includes steps of: determining a temporal motion vector prediction value of a to-be-processed coding unit, where the temporal motion vector prediction value is a temporal motion vector prediction value of a sub-block, a temporal motion vector of which is obtainable through prediction, in sub-blocks adjacent to the to-be-processed coding unit and/or sub-blocks in the to-be-processed coding unit; determining a motion vector residual prediction value of the to-be-processed coding unit according to the temporal motion vector prediction value; determining a motion vector of a sub-block in the to-be-processed coding unit according to the temporal motion vector prediction value and the motion vector residual prediction value and performing a motion compensation according to the motion vector of the sub-block in the to-be-processed coding unit to determine a prediction block of the to-be-processed coding unit.

Abstract: Techniques for video processing, including video coding, video decoding and video transcoding are described. One example method includes performing a conversion between a video picture that includes one or more tiles and one or more rectangular slices and a bitstream of the video according to a rule. The rule specifies that, for iteratively determining information about the one or more rectangular slices, a variable indicating a tile index is updated only for slices having indices that are smaller than a value equal to a number of slices in the video picture minus 1.

Abstract: Techniques for video processing, including video coding, video decoding and video transcoding are described. One example method includes performing a conversion between a video picture that includes one or more tiles and one or more rectangular slices and a bitstream of the video according to a rule. The rule specifies that, for iteratively determining information about the one or more rectangular slices, a variable indicating a tile index is updated only for slices having indices that are smaller than a value equal to a number of slices in the video picture minus 1.

Abstract: A method includes performing a conversion between a video comprising a video picture that includes one or more subpictures and a bitstream of the video according to a format rule. The format rule specifies that whether each of the one or more subpictures in the video picture includes a single slice is determined based on a constraint flag.

Abstract: Techniques for video processing, including video coding, video decoding and video transcoding are described. One example method includes performing a conversion between a video picture that includes one or more tiles and one or more rectangular slices and a bitstream of the video according to a rule. The rule specifies that, for iteratively determining information about the one or more rectangular slices, a variable indicating a tile index is updated only for slices having indices that are smaller than a value equal to a number of slices in the video picture minus 1.

Abstract: Embodiments of the present disclosure provide a solution for video processing. A method for video processing is proposed. The method comprises: obtaining a reference picture for a target picture of a video; determining whether the reference picture is to be used for filtering the target picture based at least in part on a difference between the reference picture and the target picture; and in accordance with a determination that the reference picture is to be used for filtering the target picture, performing temporal filtering on the target picture based on the reference picture. Compared with the conventional solution, the proposed method can advantageously improve the coding speed and efficiency.

Abstract: Methods, apparatus, systems for video processing, including video encoding or video decoding are described. One example method includes performing a conversion between a video including a video picture that includes a video slice and a bitstream of the video. The bitstream conforms to a format rule specifying that a slice type of the video slice determines a manner by which certain information from a picture header for the video picture is inherited by a slice header of the video slice.

Abstract: A method for deriving motion vector is provided, this method includes: obtaining a space domain motion vector prediction and a time domain motion vector prediction of adjacent blocks of a coding unit in a predetermined direction; performing a filtering operation on the space domain motion vector and the time domain motion vector prediction to obtain the space domain motion vector prediction and the time domain motion vector prediction of the filtered adjacent blocks; determining, according to a predetermined inter-frame prediction mode, reference motion vectors of a current block in four side directions by using the space domain motion vector prediction and the time domain motion vector prediction of the filtered adjacent blocks and a coordinate position of the current block in the coding unit; and deriving motion vectors of the current block according to the reference motion vectors and the coordinate position of the current block in the coding unit.

Abstract: Methods, systems, apparatus for video processing are described. The processing may include encoding, decoding or transcoding. One example video processing method includes performing a conversion between a video including one or more pictures and a bitstream of the video according to a format rule. The format rule specifies to include, in a general constrain syntax structure, a syntax element indicating whether each picture includes only one slice, and whether a picture header syntax structure is present in a slice header.

Abstract: Methods, apparatus, systems for video processing, including video encoding or video decoding are described. One example method includes performing a conversion between a video including a video picture that includes one or more subpictures and a bitstream of the video. The bitstream conforms to a format rule specifying that a first syntax element indicating whether an operation is performed across a boundary of a subpicture in the coded layer video sequence is selectively included responsive to a number of subpictures in the video picture.

Abstract: Devices, systems and methods for digital video coding, which includes methods for transform design, are described. In a representative aspect, a method of video processing includes performing a conversion between a current video block of a video and a bitstream of the video based on a rule, wherein the rule specifies that a selection of a transform matrix set for performing a transform operation during the conversion is based on a low-frequency non-separable transform index indicated in the bitstream, wherein the rule specifies that the transform operation includes, during an encoding operation, coding the current video block into the bitstream by applying a forward transform on residual values of the current video block, or wherein the rule specifies that the transform operation includes, during a decoding operation, generating from the bitstream the current video block by applying an inverse transform to scaled coefficients indicated in the bitstream.

Abstract: Techniques for video processing, including video coding, video decoding and video transcoding are described. One example method includes performing a conversion between a video picture that includes one or more tiles and one or more rectangular slices and a bitstream of the video according to a rule. The rule specifies that, for iteratively determining information about the one or more rectangular slices, a variable indicating a tile index is updated only for slices having indices that are smaller than a value equal to a number of slices in the video picture minus 1.

Abstract: Methods, systems, apparatus for video processing are described. The processing may include encoding, decoding or transcoding. One example video processing method includes performing a conversion between a video including one or more pictures and a bitstream of the video according to a format rule. The format rule specifies to include, in a general constrain syntax structure, a syntax element indicating whether each picture includes only one slice, and whether a picture header syntax structure is present in a slice header.

Abstract: Methods, systems, apparatuses for video processing are described. A method for processing video includes performing a conversion between a video and a bitstream of the video according to a format rule, and wherein the format rule specifies to include, in a general constraint syntax structure associated with the video, one or more general constraint flags indicating whether corresponding syntax elements are included in a sequence parameter set (SPS) and/or a picture parameter set (PPS) and/or a picture header (PH) and/or a slice header (SH) or to constrain values of the syntax elements in the SPS and/or the PPS and/or the PH and/or the SH.

Abstract: A video processing method is described. The method includes performing a conversion between a video region of a video and a coded representation of the video. The performing of the conversion includes configuring, based on a partition type of the video region, a context model for coding a first bin. The first bin and a second bin are included in a bin string corresponding to an index of a secondary transform tool. The index indicates an applicability of the secondary transform tool and/or a kernel information of the secondary transform tool. The secondary transform tool includes applying, during encoding, a forward secondary transform to an output of a forward primary transform applied to a residual of a video block prior to quantization, or applying, during decoding, an inverse secondary transform to an output of dequantization to the video block before applying an inverse primary transform.

Abstract: Methods, systems, apparatus for video processing are described. A method for processing video includes performing a conversion between a video and a bitstream of the video according to a format rule, and wherein the format rule specifies whether a syntax element in a sequence parameter set (SPS) based on a value of a general constraint flag.

Abstract: A method includes performing a conversion between a video including a video picture including one or more tiles and a bitstream of the video. The video picture refers to a picture parameter set, and the picture parameter set conforms to a format rule specifying that the picture parameter set includes a list of column widths for N tile columns, where N is an integer. An (N?1)-th tile column exists in the video picture and the (N?1)-th tile column has a width that is equal to an (N?1)-th entry in a list of explicitly included tile column widths plus one number of coding tree blocks.

Abstract: Devices, systems and methods for digital video coding, which includes methods for transform design, are described. In a representative aspect, a method of video processing includes performing a conversion between a current video block of a video and a bitstream of the video based on a rule, wherein the rule specifies that a selection of a transform matrix set for performing a transform operation during the conversion is based on a low-frequency non-separable transform index indicated in the bitstream, wherein the rule specifies that the transform operation includes, during an encoding operation, coding the current video block into the bitstream by applying a forward transform on residual values of the current video block, or wherein the rule specifies that the transform operation includes, during a decoding operation, generating from the bitstream the current video block by applying an inverse transform to scaled coefficients indicated in the bitstream.