Aspects of the disclosure include methods, apparatuses, and non-transitory computer-readable storage mediums for video encoding/decoding. An apparatus includes processing circuitry that decodes prediction information of a current block in a current picture that is a part of a coded video sequence. The prediction information indicates a cross component filtering (CCF) process for the current block. The processing circuitry generates filtered reconstruction samples of the current block by applying the CCF process on at least one of predicted samples, residual values, or reconstruction samples of the current block. The filtered reconstruction samples of the current block are used for reconstruction of a subsequent block. The processing circuitry reconstructs the current block and the subsequent block based on the filtered reconstruction samples of the current block.

Disclosed herein are exemplary embodiments of methods, apparatus, and systems for performing content-adaptive deblocking to improve the visual quality of video images compressed using block-based motion-predictive video coding. For instance, in certain embodiments of the disclosed technology, edge information is obtained using global orientation energy edge detection (“OEED”) techniques on an initially deblocked image. OEED detection can provide a robust partition of local directional features (“LDFs”). For a local directional feature detected in the partition, a directional deblocking filter having an orientation corresponding to the orientation of the LDF can be used. The selected filter can have a filter orientation and activation thresholds that better preserve image details while reducing blocking artifacts. In certain embodiments, for a consecutive non-LDF region, extra smoothing can be imposed to suppress the visually severe blocking artifacts.

Disclosed herein are exemplary embodiments of methods, apparatus, and systems for performing content-adaptive deblocking to improve the visual quality of video images compressed using block-based motion-predictive video coding. For instance, in certain embodiments of the disclosed technology, edge information is obtained using global orientation energy edge detection (“OEED”) techniques on an initially deblocked image. OEED detection can provide a robust partition of local directional features (“LDFs”). For a local directional feature detected in the partition, a directional deblocking filter having an orientation corresponding to the orientation of the LDF can be used. The selected filter can have a filter orientation and activation thresholds that better preserve image details while reducing blocking artifacts. In certain embodiments, for a consecutive non-LDF region, extra smoothing can be imposed to suppress the visually severe blocking artifacts.

A method for decoding a video according to the present invention may comprise: deriving a spatial merge candidate for a current block, generating a merge candidate list for the current block based on the spatial merge candidate, obtaining motion information for the current block based on the merge candidate list, and performing motion compensation for the current block using the motion information. Herein, if the current block does not have a pre-defined shape or does not have a size equal to or greater than a pre-defined size, the spatial merge candidate of the current block is derived based on a block having the pre-defined shape or having a size equal to or greater than the pre-defined size, the block comprising the current block.

A method for decoding a video according to the present invention may comprise: deriving a spatial merge candidate for a current block, generating a merge candidate list for the current block based on the spatial merge candidate, obtaining motion information for the current block based on the merge candidate list, and performing motion compensation for the current block using the motion information. Herein, if the current block does not have a pre-defined shape or does not have a size equal to or greater than a pre-defined size, the spatial merge candidate of the current block is derived based on a block having the pre-defined shape or having a size equal to or greater than the pre-defined size, the block comprising the current block.

Provided is a video decoding method including obtaining split information indicating whether a current block is to be split; and when the split information indicates that the current block is to be split, splitting the current block into at least two lower blocks, obtaining encoding order information indicating an encoding order of the at least two lower blocks of the current block from the bitstream, determining a decoding order of the at least two lower blocks based on the encoding order information, and decoding the at least two lower blocks according to the decoding order.

Provided is a video decoding method including obtaining split information indicating whether a current block is to be split; and when the split information indicates that the current block is to be split, splitting the current block into at least two lower blocks, obtaining encoding order information indicating an encoding order of the at least two lower blocks of the current block from the bitstream, determining a decoding order of the at least two lower blocks based on the encoding order information, and decoding the at least two lower blocks according to the decoding order.

Concepts are described, including encoding of a video into data stream and decoding of a data stream having a video encoded thereinto, using motion compensation prediction between pictures of equal resolution and pictures of different resolution, based on motion vectors at a half-sample resolution and on motion vectors at a different resolution using interpolation filters to obtain sub-sample values within a reference sample array. The interpolation filter is selected from two interpolation filter versions different in a higher edge preserving property, and the selection is depending on whether a current picture is equal in picture resolution to the reference sample array in horizontal and/or vertical dimension, and/or a constraint information in the data stream.

Concepts are described, including encoding of a video into data stream and decoding of a data stream having a video encoded thereinto, using motion compensation prediction between pictures of equal resolution and pictures of different resolution, based on motion vectors at a half-sample resolution and on motion vectors at a different resolution using interpolation filters to obtain sub-sample values within a reference sample array. The interpolation filter is selected from two interpolation filter versions different in a higher edge preserving property, and the selection is depending on whether a current picture is equal in picture resolution to the reference sample array in horizontal and/or vertical dimension, and/or a constraint information in the data stream.

According to one embodiment of the present document, a cross component adaptive loop filtering (CCALF) process may be performed. The CCALF process can enhance the filtering performance for chroma components and improve the subjective/objective image quality of a picture.