Abstract: Systems, methods and apparatus for video processing are described. The video processing may include video encoding, video decoding, or video transcoding. One example method of video processing includes performing a conversion between a video and a bitstream of the video according to a format rule. The format rule specifies that a first field at a sequence level or a picture level or a slice level controls a value of a second field in an adaptation parameter set.

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 and a bitstream of the video according to a rule, and wherein the rule specifies that a syntax element is included in a profile, tier, level information syntax structure to indicate whether one or more general constraint information syntax elements are included in a general constraint information syntax structure and/or whether the general constraint information syntax structure is included in the profile, tier, level information syntax structure.

Abstract: An example method of video processing includes determining, for a conversion between a block of a first sub-picture of a video and a bitstream representation of the video, whether to apply a deblocking process across an edge between the block and a neighboring block of a second sub-picture based on whether a loop filtering process is allowed across subpicture boundaries. The method also includes performing the conversion based on the determining.

Abstract: A method for visual media processing includes performing a conversion between a current video unit of a visual media data and a bitstream representation of the current video unit. The bitstream representation is configured according to a format rule. The format rule specifies a level of a video segment at which one or more syntax elements indicative of a scaling factor by which a chroma residual is scaled for coding the current video unit is selectively included in the bitstream representation.

Abstract: A method of video processing is described. The method includes determining, for a conversion between a current video block of a video and a coded representation of the video, whether a certain partitioning scheme is allowed for the current video block according to a rule that depends on a coding mode type used for representing the current video block in the coded representation and a dimension of the current video block; and performing the conversion based on the determining.

Abstract: Methods, systems, and devices for coding or decoding video wherein the picture partition mode is based on block size are described. An example method for video processing includes using a dimension of a virtual pipeline data unit (VPDU) used for a conversion between a video comprising one or more video regions comprising one or more video blocks and a bitstream representation of the video to perform a determination of whether a ternary-tree (TT) or a binary tree (BT) partitioning of a video block of the one or more video blocks is enabled, and performing, based on the determination, the conversion, wherein the dimension is equal to VSize in luma samples, wherein dimensions of the video block are CtbSizeY in luma samples, wherein VSize=min(M, CtbSizeY), and wherein M is a positive integer.

Abstract: A video processing method is provided to include performing a conversion between a video and a bitstream of the video, wherein the bitstream conforms to a format rule, and wherein the format rule specifies a condition that controls whether or how one or more syntax elements related to picture order counts for a long term reference picture are included in a reference picture list syntax structure in the bitstream.

Abstract: Examples of video encoding methods and apparatus and video decoding methods and apparatus are described. An example method of video processing includes performing a conversion between a current picture of a video and a bitstream of the video according to a rule. The rule specifies that a number of entries in a reference picture list of the current picture is greater than 0 in response to (1) one or more slices in the current picture being allowed to have a slice type other than an Intra (I) slice type, and (2) reference picture list (RPL) information being present in a picture 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 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: A method of video processing is provided that includes performing a conversion between a block of a video and a bitstream of the video. The bitstream conforms to a formatting rule specifying that a size of a merge estimation region (MER) is indicated in the bitstream and the size of the MER is based on a dimension of a video unit. The MER comprises a region used for deriving a motion candidate for the conversion.

Abstract: A method includes determining, for a conversion between a video block of a video and a bitstream of the video, a size of prediction block corresponding to the video block according to a rule. The method also includes performing the conversion based on the determining. The rule specifies that a first size of the prediction block is determined responsive to whether a prediction refinement using optical flow technique is used for coding the video block. The video block has a second size and is coded using an affine merge mode or an affine advanced motion vector prediction mode.

Abstract: A method for video processing includes performing a conversion between a current video block of a video and a bitstream representation of the current video block using a matrix based intra prediction (MIP) mode, where the conversion includes performing the upsampling operation in which the final prediction block is determined by using a reduced prediction block of the current video block and by using reconstructed neighboring samples of the current video block according to a rule, and where the reduced prediction block is obtained by performing the matrix vector multiplication operation on reduced boundary samples of the current video block.

Abstract: Systems, methods and apparatus for video processing are described. The video processing may include video encoding, video decoding, or video transcoding. One example method of video processing includes performing a conversion between a video and a bitstream of the video according to a format rule. The format rule specifies that constraints on values of one or more first syntax elements in an adaptation parameter set are defined based on semantics of second syntax elements in a picture header and/or a slice header when a picture or a slice referring to the adaptation parameter set.

Abstract: Devices, systems, and methods for digital video coding, which includes matrix-based intra prediction methods for video coding, are described. In a representative aspect, a method for video processing includes performing a conversion between a current video block of a video and a bitstream representation of the current video block using a matrix based intra prediction (MIP) mode in which a prediction block of the current video block is determined by performing, on previously coded samples of the video, a boundary downsampling operation, followed by a matrix vector multiplication operation, and followed by an upsampling operation, where the upsampling operation is performed, in both a vertical direction and a horizontal direction in a fixed order, on samples obtained from the matrix vector multiplication operation.

Abstract: Video processing, including video coding, video decoding and video transcoding, is described. One example method includes performing a conversion between a video comprising a video picture and a bitstream of a video according to a rule, where the rule specifies that syntax elements indicate a first width and a first height of a scaling window for the video picture, and where the rule specifies that a range of permissible values for the syntax elements include values greater than or equal to two times a second width of the video picture and two times a second height of the video picture.

Abstract: Devices, systems and methods related to digital video coding, and specifically, to signaling of slice types in video picture headers are described. One example method of video processing includes performing a conversion between a video including one or more video pictures including one or more slices and a bitstream of the video, wherein the bitstream conforms to a format rule, and wherein the format rule specifies that for a video picture of the one or more video pictures having all slices coded as I slices, P slice and B slice related syntax elements are omitted from a picture header for the video picture.

Abstract: Several techniques for video encoding and video decoding are described. One example 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 flag indicating whether transform skip residual coding is enabled at a video unit level is present in the bitstream is based on values of a first syntax element indicating usage of sign data hiding in the video unit and a second syntax element indicating usage of dependent quantization in the video unit.

Abstract: A method performed by a first network device comprises reaching a synchronization state with a first communication device based on alignment information of a first interface of the first network device. The alignment information of the first interface includes at least one of a line rate order for line rate iteration, an iteration time interval and an iteration start time. The method further comprises determining whether a second network device has reached the synchronization state with a second communication device at a same line rate as the first interface, wherein the second network device includes a second interface, and the second network device tries to reach the synchronization state with the second communication device based on the same alignment information as the first interface of the first network device. The method further comprises locking the same line rate at the first interface of the first network device.

Abstract: A video processing method includes performing a conversion between a video comprising a video unit and a bitstream of the video according to a rule. The rule specifies whether or how to include, in an adaptation parameter set (APS), information related to a scaling list of the video is based on a first syntax element. The first syntax element indicates whether the APS includes chroma component related syntax elements and is independent of one or more syntax elements in a sequence parameter set (SPS).

Abstract: Several techniques for video encoding and video decoding are described. One example method includes performing a conversion between a subpicture in a video picture of a video and a bitstream of the video according to a rule. The rule specifies that, in in case a subpicture is treated as a video picture for the conversion, a cross-layer alignment restriction is applied to less than all of the multiple layers including a current layer that includes the subpicture and a subset of layers associated with the current layer.