# US 2024/0205448 A1 · Video Processing Methods and Apparatuses for Sub-block Motion Compensation in Video Coding Systems > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2024/0205448 A1 - Document ID: US20240205448A1 - Status: Published application - Kind: A1 - Application number: 18/595,935 - Filed: 2024-03-05 - Published: 2024-06-20 - Earliest claimed: 2018-04-02 - Assignees: Hfi Innovation Inc. - Applicants: HFI Innovation Inc. - Inventors: Tzu-Der CHUANG; Ching-Yeh CHEN; Chen-Yen LAI; Chih-Wei HSU - Web page: https://patentgrep.com/patent/US20240205448A1 ## CPC - H04N 19/513: Processing of motion vectors - H04N 19/105: Selection of the reference unit for prediction within a chosen coding or prediction mode, e.g. adaptive choice of position and number of pixels used for prediction - H04N 19/119: Adaptive subdivision aspects, e.g. subdivision of a picture into rectangular or non-rectangular coding blocks - H04N 19/159: Prediction type, e.g. intra-frame, inter-frame or bidirectional frame prediction - H04N 19/176: the region being a block, e.g. a macroblock - H04N 19/533: Motion estimation using multistep search, e.g. two-dimensional [2D]-log search or one-at-a-time search [OTS] - H04N 19/55: Motion estimation with spatial constraints, e.g. at image or region borders - H04N 19/70: characterised by syntax aspects related to video coding, e.g. related to compression standards - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract Video processing methods for coding a current block comprise receiving input data of a current block, checking whether a sub-block motion compensation coding tool is applied to the current block based on a size, width, or height of the current block, a size, area, shape, width, or height of sub-blocks partitioned from the current block, an inter prediction direction of a sub-block Motion Vector (MV), primary MV, or one of control point MVs of the current block, a primary MV, the control point MVs, affine parameters; encoding or decoding the current block using the sub-block motion compensation coding tool or another coding tool according to a result of the checking indicating whether application of the sub-block motion compensation coding tool is valid or invalid; and a MV clipping process is applied to each sub-block in the current block if the checking result is false, indicating the validity is invalid. ## Claims ### Claim 1 A video processing method for sub-block motion compensation in a video coding system, comprising: receiving input video data associated with a current block in a current picture to be encoded or decoded; checking whether a sub-block motion compensation coding tool is applied to the current block based on a size, width, or height of the current block, a size, area, shape, width, or height of sub-blocks partitioned from the current block, an inter prediction direction of a sub-block Motion Vector (MV), primary MV, or one of control point MVs of the current block, a primary MV, the control point MVs, affine parameters, or a combination thereof; encoding or decoding the current block using the sub-block motion compensation coding tool or another coding tool according to a result of the checking indicating whether application of the sub-block motion compensation coding tool is valid or invalid; a MV clipping process is applied to each sub-block in the current block if the checking result is false, indicating the validity is invalid; and wherein the MV clipping process includes setting all the sub-block MVs equal to the primary MV. ### Claim 2 (depends on 1) The method of claim 1, wherein the sub-block motion compensation coding tool is selected from a group comprising subblock Temporal Motion Vector Prediction (subblock TMVP), Spatial-Temporal Motion Vector Prediction (STMVP), affine motion compensation prediction, and sub-block refined Pattern-based Motion Vector Derivation (PMVD) mode. ### Claim 3 A video processing method for sub-block motion compensation in a video coding system, comprising: receiving input video data associated with a current block in a current picture; adaptively determining a sub-block size for partitioning the current block, wherein the sub-block size for partitioning the current block and a sub-block size for partitioning another block coded by a same sub-block motion compensation coding tool are different; partitioning the current block into multiple sub-blocks according to the sub-block size; deriving sub-block Motion Vectors (MVs) associated with the sub-blocks in the current block according to the sub-block motion compensation coding tool; and applying motion compensation to the current block using the sub-block MVs to encode or decode the current block. ### Claim 4 (depends on 3) The method of claim 3, wherein the sub-block size is determined according to a derived MV of the current block, one or more control point MVs of the current block, or a derived sub-block MV. ### Claim 5 (depends on 4) The method of claim 4, wherein a first sub-block size is used if the derived MV, one or more control point MVs of the current block, or the derived sub-block MV is bi-prediction or multi-hypothesis prediction and a second sub-block size is used if the derived MV, one or more control point MVs of the current block, or the derived sub-block MV is uni-prediction, and the first sub-block size is larger than the second sub-block size. ### Claim 6 (depends on 4) The method of claim 4, wherein the sub-block size is restricted to be larger than or equal to a minimum sub-block size, and a first minimum sub-block size for bi-predicted or multi-hypothesis predicted sub-blocks is set to be larger than a second minimum sub-block size for uni-predicted sub-blocks. ### Claim 7 (depends on 3) The method of claim 3, wherein the sub-block size is determined or restricted according to control point MVs of the current block when the sub-block motion compensation coding tool is affine motion compensation prediction. ### Claim 8 (depends on 3) The method of claim 3, wherein the sub-block size is determined or restricted according to a distance between the current picture and a reference picture of the current block. ### Claim 9 (depends on 3) The method of claim 3, wherein the sub-block size is determined or restricted according to a size, width, or height of the current block, a size, area, shape, width, or height of sub-blocks partitioned from the current block, an inter prediction direction of a sub-block MV, a control point MV, or a current MV, control point MVs, affine parameters, or a combination thereof. ### Claim 10 (depends on 3) The method of claim 3, wherein the sub-block motion compensation coding tool is selected from a group comprising subblock Temporal Motion Vector Prediction (sub-PU TMVP), Spatial-Temporal Motion Vector Prediction (STMVP), affine motion compensation prediction, and sub-block refined Pattern-based Motion Vector Derivation (PMVD) mode. ### Claim 11 (depends on 3) The method of claim 3, further comprising signaling information related to the sub-block size for partitioning the current block in a video bitstream by a video encoder.