The disclosure discloses a method for processing a video signal and an apparatus therefor. Specifically, the method of processing a video signal based on an inter prediction, comprising: configuring a merge list based on a neighboring block of a current block; adding a history based merge candidate included in a history based merge candidate list to the merge list when a number of a merge candidate included in the merge list is smaller than a first predetermined number; obtaining a merge index indicating a merge candidate used for an inter prediction of the current block within the merge list; and generating a prediction block of the current block based on motion information of a merge candidate indicated by the merge index, wherein a step of adding the history based merge candidate to the merge list comprises checking whether a second predetermined number of the history based merge candidate within the history based merge candidate list has the same motion information as the merge candidate included in the merge list.

Various innovations facilitate the use of intra-picture prediction modes such as palette prediction mode, intra block copy mode, intra line copy mode and intra string copy mode by an encoder or decoder when wavefront parallel processing (“WPP”) is enabled. For example, for a palette coding/decoding mode, an encoder or decoder predicts a palette for an initial unit in a current WPP row of a picture using previous palette data from a previous unit in a previous WPP row of the picture. Or, as another example, for an intra copy mode (e.g., intra block copy mode, intra string copy mode, intra line copy mode), an encoder enforces one or more constraints attributable to the WPP, or a decoder receives and decodes encoded data that satisfies one or more constraints attributable to WPP.

Various innovations facilitate the use of intra-picture prediction modes such as palette prediction mode, intra block copy mode, intra line copy mode and intra string copy mode by an encoder or decoder when wavefront parallel processing (“WPP”) is enabled. For example, for a palette coding/decoding mode, an encoder or decoder predicts a palette for an initial unit in a current WPP row of a picture using previous palette data from a previous unit in a previous WPP row of the picture. Or, as another example, for an intra copy mode (e.g., intra block copy mode, intra string copy mode, intra line copy mode), an encoder enforces one or more constraints attributable to the WPP, or a decoder receives and decodes encoded data that satisfies one or more constraints attributable to WPP.

A 360-degree video data processing method performed by a 360-degree video transmission device, according to the present invention, comprises the steps of: acquiring 360-degree video data; processing the 360-degree video data so as to acquire a 2D picture; dividing the 2D picture so as to derive sub-pictures; generating metadata for the 360-degree video data; encoding at least one of the sub-pictures; and performing processing for storing or transmitting the encoded at least one sub-picture and the metadata, wherein the metadata includes position information of the sub-picture on the 2D picture.

The present disclosure relates to motion vector determination using template or bilateral matching and predictor generation based on the motion vector. The template or bilateral matching and/or the predictor generation use interpolation filtering. The interpolation filtering operation accesses integer sample positions within a window, and further uses padded sample values for integer sample positions outside the window, which are based on at least one sample within said window, and uses the accessed integer sample position values as well as the padded sample values to perform the template or bilateral matching and/or predictor generation.

The present disclosure relates to motion vector determination using template or bilateral matching and predictor generation based on the motion vector. The template or bilateral matching and/or the predictor generation use interpolation filtering. The interpolation filtering operation accesses integer sample positions within a window, and further uses padded sample values for integer sample positions outside the window, which are based on at least one sample within said window, and uses the accessed integer sample position values as well as the padded sample values to perform the template or bilateral matching and/or predictor generation.

A method for coding a video implemented in an encoder or a decoder including the enhanced interpolation filter, EIF, for motion compensation, the method comprising: i) determining control point motion vectors, CPMVs, for a block according to affine inter-prediction, the block being an affine block or a sub-block of the affine block; ii) for a predefined sub-block size determining a reference area for a sub-block with the predefined sub-block size according to values of the CPMVs; iii) comparing the determined reference area with a predefined threshold; iv) applying EIF for motion compensation, comprising deriving the pixel-based motion vector field for the block; wherein if the determined reference area is larger than the threshold, deriving the pixel-based motion vector field for the block further comprises motion vector clipping, wherein motion vector clipping range is determined based on motion model of the block and the size of the block.

A method of video processing includes performing a conversion between a video comprising a picture that includes multiple sub-pictures and a coded representation of the video using a coding mode according to a rule. The rule specifies that certain stored information about a previous sub-picture is reset prior to processing each next sub-picture of the multiple sub-pictures.

A system for storing and providing video pixel data for video encoding is disclosed. The system comprises a memory storage and a cache storage. The system further comprises a controller. The controller is configured to receive a request that causes transferring of a reference pixel block of a video, wherein the video is being encoded using the reference pixel block. The controller is configured to determine whether the reference pixel block has at least a portion that is outside a frame of the video. In response to the determination of the reference pixel block having at least a portion outside the frame of the video, the controller is configured to cause a portion of the reference pixel block of the video inside the frame of the video to be fetched from a memory storage and stored in a cache storage, pad a remaining missing portion of the reference pixel block of the video outside the frame of the video with padding pixel data to form the reference pixel block, and transfer the reference pixel block in response to the request.

The embodiments disclosed herein relate to the construction of a search space for determining a motion vector for a current block of a picture in a video sequence. The search space construction is split into in two main stages, wherein a first and a second partial search space are respectively determined. Based on an initial estimate of a motion vector, a first search space is first constructed. A first and a second candidate motion of the first search space are identified according to a cost function. Based on the first and the second candidate motion vectors, a second search space is constructed. The motion vector for the current block is selected from the candidate motion vectors of the first search space and the second search space.