Systems, methods, and instrumentalities for affine motion estimation for affine model-based video coding may be disclosed herein. A first motion vector (MV) set including one or more MVs may be derived for a first coding block. The MVs may be control point MVs (CPMVs) and the MVs may be derived by performing affine motion estimation (ME) associated with the first coding block. The first MV set may be added to a recently-estimated MV list. A head of the recently-estimated MV list may be set to the first MV set. The recently-estimated MV list may be empty or may contain one or more previously-added MV sets.

A picture decoding method includes: determining motion information of a to-be-decoded block; obtaining a first decoding prediction block of the to-be-decoded block based on the motion information; performing motion search with first precision in the prediction reference picture block to obtain at least two second decoding prediction blocks; performing downsampling on the first decoding prediction block and the at least two second decoding prediction blocks to obtain a first sampling pixel array and at least two second sampling pixel arrays, respectively; calculating a difference between the first sampling pixel array and each of the second sampling pixel arrays, and using, as a target prediction motion vector, a motion vector corresponding to a second sampling pixel array with a minimum difference; and obtaining a target decoding prediction block of the to-be-decoded block based on the target prediction motion vector, and decoding the to-be-decoded block based on the target decoding prediction block.

The disclosure discloses a method for processing video signals and an apparatus therefor. Specifically, the method of processing video signals based on inter prediction, comprising: configuring a merge candidate list based on a spatial neighboring block and a temporal neighboring block to a current block; adding a history-based merge candidate of the current block to the merge candidate list; obtaining a merge index indicating a merge candidate used for an inter prediction of the current block within the merge candidate list; generating a prediction sample of the current block based on motion information of the merge candidate indicated by the merge index; and updating a history-based merge candidate list based on the motion information.

The disclosure discloses a method for processing video signals and an apparatus therefor. Specifically, the method of processing video signals based on inter prediction, comprising: configuring a merge candidate list based on a spatial neighboring block and a temporal neighboring block to a current block; adding a history-based merge candidate of the current block to the merge candidate list; obtaining a merge index indicating a merge candidate used for an inter prediction of the current block within the merge candidate list; generating a prediction sample of the current block based on motion information of the merge candidate indicated by the merge index; and updating a history-based merge candidate list based on the motion information.

A video motion estimation method including obtaining a plurality of image frames in a video, and performing scenario classification processing on the plurality of image frames to obtain a plurality of image frame sets. The method further includes extracting a contour feature and a color feature of a foreground object of each image frame, and determining a search range corresponding to each image frame set. The method further includes determining a starting search point in each predicted frame. The method further includes, for each image frame set, performing motion estimation processing in a search region corresponding to the search range of each predicted frame set based on the starting search point of the respective predicted frame, a reference block in at least one reference frame of the respective image frame set, and the color feature of the foreground object, to obtain a motion vector corresponding to the reference block.

A video encoding system encodes source image data corresponding with an image includes a low resolution pipeline that receives the source image data corresponding with a first coding block in the image. The low resolution pipeline includes a low resolution motion estimation block programmed to generate a first downscaled coding block by downscaling resolution of the source image data corresponding with the first coding block. The first downscaled coding block comprises a first downscaled prediction block corresponding with a first prediction block in the first coding block. The low resolution pipeline may also perform several low resolution motion estimation searches to generate motion vector candidates. The video encoding system also includes a main pipeline that receives the source image data and determines encoding parameters to be used to encode the first coding block based at least partially on the motion vector candidates.

A video encoding system encodes source image data corresponding with an image includes a low resolution pipeline that receives the source image data corresponding with a first coding block in the image. The low resolution pipeline includes a low resolution motion estimation block programmed to generate a first downscaled coding block by downscaling resolution of the source image data corresponding with the first coding block. The first downscaled coding block comprises a first downscaled prediction block corresponding with a first prediction block in the first coding block. The low resolution pipeline may also perform several low resolution motion estimation searches to generate motion vector candidates. The video encoding system also includes a main pipeline that receives the source image data and determines encoding parameters to be used to encode the first coding block based at least partially on the motion vector candidates.

A method of coding video data, including constructing a history-based motion vector prediction (HMVP) candidate history table that includes motion vector information of previously coded blocks that extend beyond adjacent neighboring blocks of a current block, constructing a motion vector predictor list, and adding one or more HMVP candidates from the HMVP candidate history table to the motion vector predictor list. Adding the one or more HMVP candidates from the HMVP candidate history table comprises comparing a first HMVP candidate in the HMVP candidate history table to two entries in the motion vector predictor list and no other entries, and adding the first HMVP candidate to the motion vector predictor list when the first HMVP candidate is different than both of the two entries in the motion vector predictor list. The method also includes coding the current block of video data using the motion vector predictor list.

A method of coding video data, including constructing a history-based motion vector prediction (HMVP) candidate history table that includes motion vector information of previously coded blocks that extend beyond adjacent neighboring blocks of a current block, constructing a motion vector predictor list, and adding one or more HMVP candidates from the HMVP candidate history table to the motion vector predictor list. Adding the one or more HMVP candidates from the HMVP candidate history table comprises comparing a first HMVP candidate in the HMVP candidate history table to two entries in the motion vector predictor list and no other entries, and adding the first HMVP candidate to the motion vector predictor list when the first HMVP candidate is different than both of the two entries in the motion vector predictor list. The method also includes coding the current block of video data using the motion vector predictor list.

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.