A decoder includes circuitry configured to receive a bitstream; construct, for a current block, a motion vector candidate list including a motion vector candidate having motion information that characterizes a global motion vector; reorder the motion vector candidate list such that the motion vector candidate having the motion information that characterizes the global motion vector is first in the reordered motion vector candidate list; and reconstruct pixel data of the current block and using the reordered motion vector candidate list. Related apparatus, systems, techniques and articles are also described.

A filter generation method according to one embodiment is a filter generation method for generating a filter for an inter prediction image in moving image coding or video coding, wherein a computer executes a first acquisition procedure for acquiring, for each of subblocks included in a coding object block, a region in a reference image that corresponds to the subblock, a second acquisition procedure for referring to block segmentation information of the reference image and acquiring a coding block that is a block of the reference image which includes the region, and a generation procedure for generating, for the coding object block or each of a plurality of coding object blocks, an image obtained by performing an inverse transformation on one or more coding blocks each acquired in the second acquisition procedure as the filter.

A method of encoding video data by an electronic device is provided. The electronic device determines whether an affine enabled flag corresponding to one or more image frames included in the video data is true. The electronic device determines a maximum number of zero or more subblock-based merging motion vector prediction candidates corresponding to the one or more image frames when the affine enabled flag is true. The maximum number is in a number range of K to N, N being a first integer and K being a second integer less than N. The electronic device determines that a maximum index is in an index range of 0 to N-K and generated by subtracting the maximum number from N when the affine enabled flag is true. An index value of the maximum index is in an index range of 0 to N-1 when K is 1.

Sub-block merge motion field is combined with triangle partitioning and geometric partitioning modes to further give coding and decoding schemes flexibility. In at least one embodiment, a flag is used to signal if sub-block merge candidates are used in place of regular merge candidates. In another embodiment, regular merge candidates are replaced by sub-block merge candidates. In another embodiment, at least one motion field is stored. In another embodiment, all sub-block merge candidates or only sub-block temporal motion vector predictors or only affine predictors are considered.

A video decoding method includes obtaining a to-be-entropy-decoded syntax element in a current block by parsing a received bitstream, where the to-be-entropy-decoded syntax element includes a syntax element 1 or a syntax element 2 in the current block, obtaining a context model corresponding to the to-be-entropy-decoded syntax element, where both of a context model corresponding to the syntax element 1 and a context model corresponding to the syntax element 2 are determined from the same preset context model set, entropy decoding the to-be-entropy-decoded syntax element based on the context model corresponding to the to-be-entropy-decoded syntax element, and obtaining a reconstructed image of the current block based on the syntax element obtained by entropy decoding.

A method of video processing is provided. The method includes: determining, for a conversion between a current video block of a video and a coded representation of the video, a mode of operation of an UMVE mode; and performing the conversion based on the determining, wherein the current video block is coded with an affine merge mode and motion vector differences in the affine UMVE mode, and wherein one or more fields in the coded representation correspond to the mode of operation, and wherein the one or more fields include: a list size field that indicates a size of a base affine merge candidate list for an affine merge mode with prediction offsets that is used by the UMVE mode, or a table field that signals a distance table or a direction table for the affine merge mode with prediction offsets.

An encoder includes circuitry and memory coupled to circuitry. In operation, circuitry: designs each of subpictures included in a picture in such a manner that at least one pixel included in the subpicture is included in a conformance cropping window; encodes arrangement information indicating an arrangement of each of the subpictures; and encodes each of the subpictures.

A method for processing a video signal using an affine motion prediction is disclosed. The method includes checking that a current block is encoded by the affine motion prediction, obtaining motion vectors for a plurality of control points of the current block, determining a motion vector for each of a plurality of subblocks included in the current block based on the motion vectors for the plurality of control points, and performing a prediction for the current block from the motion vector for each of the plurality of subblocks, wherein each of the plurality of subblocks is configured to have a pre-defined width and a pre-defined height.

An apparatus for video decoding includes processing circuitry. The circuitry can be configured to determine whether to apply the PROF to an affine coded block, and responsive to a determination to apply the PROF to the affine coded block, perform a PROF process. For example, during the PROF process, a prediction sample I(i,j) at a sample location (i,j) in the affine coded block can be generated. Spatial gradients g_x (i,j) and g_y (i,j) at the sample location (i,j) in the affine coded block can be generate. A prediction refinement ΔI(i,j) based on the spatial gradients g_x (i,j) and g_y (i,j) can be generated. The prediction refinement ΔI(i,j) can added to the prediction sample I(i,j) to generate a refined prediction sample. The PROF for affine prediction can be enabled according to a syntax element received at the decoder, or can be enabled by default.

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.