Aspects of the disclosure provide a method and an apparatus for video coding. A processing circuitry determines a process unit size for a decoder-side motion vector refinement (DMVR). Then, the processing circuitry enables an application of the DMVR on a current block when a size of the current block is smaller than or equal to the process unit size; and disables the application of the DMVR on the current block when the size of the current block is larger than the process unit size. In an example, the application of the DMVR refines the motion vectors with or without a template block.

Aspects of the disclosure provide a method and an apparatus for video coding. A processing circuitry determines a process unit size for a decoder-side motion vector refinement (DMVR). Then, the processing circuitry enables an application of the DMVR on a current block when a size of the current block is smaller than or equal to the process unit size; and disables the application of the DMVR on the current block when the size of the current block is larger than the process unit size. In an example, the application of the DMVR refines the motion vectors with or without a template block.

Techniques for coding and decoding video may include predicting picture regions defined by a time-varying tessellation and/or by a tessellation that varies spatially within a picture. These techniques improve decoded video quality, for example, by reducing block-based visual artifacts. Tessellation patterns may be irregular spatially to prevent alignment of some prediction region boundaries within a picture. Tessellation patterns may vary over time based on a spatial offset value, and the spatial offset value may be determined via a modulo function. Tessellation patterns may include overlapped shapes, for example when used in conjunction with overlapped block motion compensation.

Techniques for coding and decoding video may include predicting picture regions defined by a time-varying tessellation and/or by a tessellation that varies spatially within a picture. These techniques improve decoded video quality, for example, by reducing block-based visual artifacts. Tessellation patterns may be irregular spatially to prevent alignment of some prediction region boundaries within a picture. Tessellation patterns may vary over time based on a spatial offset value, and the spatial offset value may be determined via a modulo function. Tessellation patterns may include overlapped shapes, for example when used in conjunction with overlapped block motion compensation.

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.

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.

An image encoding/decoding apparatus according to the present invention can configure a merge candidate list of a current block to which a diagonal motion partition is applied, derive the motion information of the current block on the basis of the merge candidate list and a merge candidate index, and perform inter-prediction on the current block on the basis of the derived motion information.

A method and apparatus to improve compression efficiency in a video compression scheme enables use of switchable interpolation filters. The interpolation filters are used on multiple partitions of video blocks, enabling better motion compensated prediction and improved video coding efficiency. In one embodiment, an interpolation filter index is derived for triangle partitions of a block from motion information candidate parameters, so that each unidirectional motion compensation can use a different value of interpolation filter index. In another embodiment, an interpolation filter index is a function of characteristics, such as shape or area, of video partitions.

The present disclosure relates to moving picture processing, and in particular to cases where non-rectangular partitioning modes are used for the inter-prediction in a combination with weighted prediction (WP) for coding fades. Non-rectangular modes refer to those inter-prediction modes, in which case a current block is partitioned/sliced in a non-rectangular way (slices). Such modes may be triangular (TMP) or geometric (GEO) prediction. The aim of the invention is to harmonize non-rectangular partitioning modes with WP by way of disabling TMP/GEO when WP is applied. This may be accomplished by checking whether all reference pictures for a current slice are disabled, and if this is the case to disable the slice-level WP for non-rectangular prediction units. Whether the reference pictures are disabled may be determined based on conditions applied on set values, for example, of luma/chroma flags, which refer to the reference pictures.

Aspects of the disclosure provide methods, apparatuses, and non-transitory computer-readable storage mediums for video encoding/decoding. An apparatus includes processing circuitry that partitions a current block of a current picture based on a geometric partitioning mode (GPM). The current block is partitioned into two partitions in the GPM mode. Each of the partitions is associated with a respective predictor. A weighting index for a sample of the current block is determined based on a position of the sample. A weighting factor is calculated based on the weighting index of the sample according to an equation that converts the weighting index to the weighting factor. The sample is encoded based on the weighting factor and the predictor corresponding to the sample.