Abstract: A method includes performing a conversion between a video including video pictures that include one or more subpictures and a bitstream of the video. The bitstream conforms to a format rule specifying that one or more syntax structures are constrained based on a constraint flag of a syntax element that includes general constraints information.

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: A method includes performing a conversion between a video that includes at least a video tile and a bitstream of the video according to a rule. The rule specifies that a height of a slice in the video tile in units of coding tree units is derived based on a value of a first syntax element in the bitstream indicating a number of explicitly provided slice heights for slices in the video tile that includes the slice.

Abstract: Methods, apparatus, systems for video processing, including video encoding or video decoding are described. One example method includes determining an output sub-bitstream by extracting a sub-bitstream of one or more target subpictures from a bitstream of a video including video pictures. At least one of the video pictures includes one or more subpictures. The output sub-bitstream conforms to a format rule specifying that the one or more target subpictures is represented as a single subpicture in the output sub-bitstream.

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: Methods, apparatus, systems for video processing, including video encoding or video decoding are described. One example method includes performing a conversion between a video comprising a video picture that includes a video slice and a bitstream of the video. The bitstream conforms to a format rule specifying that, in case a slice type of the video slice is type P and temporal motion vector prediction is enabled, usage of reference picture resampling (RPR) for a reference picture in a collocated reference picture list is disabled. The reference picture is indicated by a reference index of a collocated picture of the video slice used for the temporal motion vector prediction.

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: 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: 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: 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: An embodiment of the present disclosure discloses an intra-prediction-based encoding and decoding method, apparatus and filter, and belongs to a video coding technical field.

Abstract: A method of video processing is described. The method includes performing a conversion between a current block of a video and a bitstream representation of the video, wherein the current block is coded with a dictionary-based coding mode using one or more dictionaries, and wherein the conversion is based on the one or more dictionaries.

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: Disclosed is a boundary filtering method for intra prediction, relating to the video encoding technology filed. Whether boundary filtering is performed on an intra prediction block or not is adaptively selected by means of a rate distortion optimization decision; during filtering, a filter coefficient exponentially attenuated relative to distance to boundary is adopted to perform filtering on the first N rows or the first N columns of the intra prediction block by means of an intra prediction block filter, and different filtering strengths are used according to different sizes of the prediction blocks. Therefore, the boundary distortion problem of intra prediction block is solved, the intra prediction precision is improved, and the encoding efficiency of intra prediction block is increased; and the practicability and the robustness of the boundary filtering technology are improved.

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: 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 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: The present application provides methods, systems, devices and computer-readable mediums for encoding and decoding transform. A method of the present application comprises: performing transform-encoding on a prediction residual block separately using a plurality of transform matrices, to obtain transformed residual blocks; based on the transformed residual block, determining, by a rate-distortion optimization decision, a transform matrix or a combination of transform matrices matching the residual characteristics of the prediction residual block from the plurality of transform matrices, and determining a transformed residual block to be outputted in a bitstream. Compared with the prior art, the method of the embodiments of the present invention performs a residual transform using transform matrices that are more closely matched with the residual characteristic, thereby improving the expression of the residual signal and improving the coding efficiency of the residual block.

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, wherein 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 included in a bin string corresponding to an index of a secondary transform tool, wherein the index indicates an applicability of the secondary transform tool and/or a kernel information of the secondary transform tool, and wherein 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: The present application provides methods, systems, devices and computer-readable mediums for encoding and decoding transform. A method of the present application comprises: performing transform-encoding on a prediction residual block separately using a plurality of transform matrices, to obtain transformed residual blocks; based on the transformed residual block, determining, by a rate-distortion optimization decision, a transform matrix or a combination of transform matrices matching the residual characteristics of the prediction residual block from the plurality of transform matrices, and determining a transformed residual block to be outputted in a bitstream. Compared with the prior art, the method of the embodiments of the present invention performs a residual transform using transform matrices that are more closely matched with the residual characteristic, thereby improving the expression of the residual signal and improving the coding efficiency of the residual block.