A video coder may be configured to determine a partitioning for a block of video data using geometric partitioning mode; construct two uni-prediction motion vector candidate lists for the block of video data, and code the block of video data using uni-prediction based on at least one of the two uni-prediction motion vector candidate lists to generate a decoded block of video data.

A video coder may be configured to determine a partitioning for a block of video data using geometric partitioning mode; construct two uni-prediction motion vector candidate lists for the block of video data, and code the block of video data using uni-prediction based on at least one of the two uni-prediction motion vector candidate lists to generate a decoded block of video data.

A macro block size determining unit 1 determines the size of each macro block on a frame-by-frame basis. A macro block dividing unit 2 divides an inputted image into macro blocks each having the size determined by the macro block size determining unit 1. A macro block coding unit 3 determines a coding mode for each of the macro blocks divided by the macro block dividing unit 2, and codes pixel values in each of the macro blocks in the determined coding mode.

A macro block size determining unit 1 determines the size of each macro block on a frame-by-frame basis. A macro block dividing unit 2 divides an inputted image into macro blocks each having the size determined by the macro block size determining unit 1. A macro block coding unit 3 determines a coding mode for each of the macro blocks divided by the macro block dividing unit 2, and codes pixel values in each of the macro blocks in the determined coding mode.

This disclosure relates to video coding and more particularly to techniques for signaling picture information for coded video. According to an aspect of an invention, first syntax element specifying an index corresponding to a collocated picture used for temporal motion vector prediction is parsed from a picture header in a case that both (a) first flag indicating whether temporal motion vector predictor can be enabled for a picture associated with the picture header and (b) second flag indicating information associated with reference picture list are equal to 1.

This disclosure relates to video coding and more particularly to techniques for signaling picture information for coded video. According to an aspect of an invention, first syntax element specifying an index corresponding to a collocated picture used for temporal motion vector prediction is parsed from a picture header in a case that both (a) first flag indicating whether temporal motion vector predictor can be enabled for a picture associated with the picture header and (b) second flag indicating information associated with reference picture list are equal to 1.

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.

A video decoding method and apparatus, a video encoding method and apparatus, a computer device, and a storage medium, which belong to the field of video processing. The video decoding method includes: performing classification on a displacement vector of a decoded block in a historical motion information list according to a following classification method, the classification method comprising: in a case that the decoded block satisfies a classification condition of any class of a plurality of classes, adding the displacement vector of the decoded block to the class, and stopping performing classification on the displacement vector of the decoded block.

A video decoding method and apparatus, a video encoding method and apparatus, a computer device, and a storage medium, which belong to the field of video processing. The video decoding method includes: performing classification on a displacement vector of a decoded block in a historical motion information list according to a following classification method, the classification method comprising: in a case that the decoded block satisfies a classification condition of any class of a plurality of classes, adding the displacement vector of the decoded block to the class, and stopping performing classification on the displacement vector of the decoded block.

A method of video decoding performed in a video decoder includes receiving a coded video bitstream including a current block that is divided into a plurality of sub-blocks. The method includes performing sub-block based affine motion compensation on the current block to generate a sub-block prediction for each pixel in each sub-block of the current block. The method further includes determining one or more spatial gradients for each sub-block prediction. The method includes performing, for each sub-block prediction, prediction refinement with an optical flow process using the respective determined one or more spatial gradients and at least one constraint included in the coded video bitstream. The method further includes adding, for each sub-block prediction, an output of the respective prediction refinement to the respective sub-block prediction to generate a final prediction for each pixel in each sub-block of the current block.