# US 2023/0054988 A1 · Video coding based on multiple sets of subblock motion vectors > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2023/0054988 A1 - Document ID: US20230054988A1 - Status: Published application - Kind: A1 - Application number: 17/975,386 - Filed: 2022-10-27 - Published: 2023-02-23 - Earliest claimed: 2019-02-28 - Assignees: Tencent America LLC - Applicants: Tencent America LLC - Inventors: Guichun LI; Xiang LI; Shan LIU - Web page: https://patentgrep.com/patent/US20230054988A1 ## CPC - H04N 19/513: Processing of motion vectors - H04N 19/52: by predictive encoding - 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 19/176: the region being a block, e.g. a macroblock - H04N 19/189: characterised by the adaptation method, adaptation tool or adaptation type used for the adaptive coding - H04N 19/436: using parallelised computational arrangements - H04N 19/577: Motion compensation with bidirectional frame interpolation, i.e. using B-pictures - H04N 19/119: Adaptive subdivision aspects, e.g. subdivision of a picture into rectangular or non-rectangular coding blocks - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract Aspects of the disclosure provide a method and an apparatus for video coding. In some examples, an apparatus includes processing circuitry that determines first motion vectors for a plurality of subblocks of a current block based on a first relative position in each subblock of the plurality of subblocks, and determines second motion vectors for the plurality of subblocks based on a second relative position in each subblock of the plurality of subblocks. The processing circuitry obtains a first set of predicted samples for the current block based on the first motion vectors of the plurality of subblocks. Further, the processing circuitry obtains a second set of predicted samples for the current block based on the second motion vectors of the plurality of subblocks, and obtains a third set of predicted samples for the current block based on the first set of predicted samples and the second set of predicted samples. ## Claims ### Claim 1 A method of video decoding in a decoder, comprising: determining first motion vectors for a plurality of subblocks of a current block based on a first relative position in each subblock of the plurality of subblocks; determining second motion vectors for the plurality of subblocks based on a second relative position in each subblock of the plurality of subblocks; obtaining a first set of predicted samples for the current block based on the first motion vectors of the plurality of subblocks; obtaining a second set of predicted samples for the current block based on the second motion vectors of the plurality of subblocks; and obtaining a third set of predicted samples for the current block based on the first set of predicted samples and the second set of predicted samples. ### Claim 2 (depends on 1) The method of claim 1, wherein the first motion vectors for the plurality of subblocks are determined based on a plurality of control point motion vectors of the current block, and the second motion vectors for the plurality of subblocks are determined based on the plurality of control point motion vectors of the current block. ### Claim 3 (depends on 1) The method of claim 1, wherein the obtaining the third set of predicted samples comprises: obtaining the third set of predicted samples for the current block based on a weighted average of the first set of predicted samples and the second set of predicted samples. ### Claim 4 (depends on 1) The method of claim 1, wherein the first relative position is a center of each subblock. ### Claim 5 (depends on 4) The method of claim 4, wherein the second relative position is a corner of each subblock. ### Claim 6 (depends on 1) The method of claim 1, wherein the first relative position and the second relative position of each subblock are symmetric with respect to one of a vertical line, a horizontal line, and a diagonal line intersecting a center of the respective subblock. ### Claim 7 (depends on 1) The method of claim 1, wherein the first relative position is a center of a first edge of each subblock, and the second relative position is a center of a second edge of each subblock. ### Claim 8 (depends on 3) The method of claim 3, wherein a first pixel in the first set of predicted samples for one of the subblocks is located at a first position in the one of the subblocks, a second pixel in the first set of predicted samples for the one of the subblocks is located at a second position in the one of the subblocks, the first position is closer to the first relative position of the one of the subblocks than the second position, and the weighted average of the first set of predicted samples and the second set of predicted samples is calculated by applying a first weight to the first pixel and a second weight to the second pixel, and the first weight being greater than the second weight. ### Claim 9 (depends on 8) The method of claim 8, wherein the weighted average of the first set of predicted samples and the second set of predicted samples is calculated by applying a first weight to a pixel in the first set of predicted samples for the one of the plurality of subblocks, and the first weight is ¾ based on the pixel being located less than three pixels away from the first relative position along a horizontal direction or a vertical direction, and the first weight is ¼ based on the pixel being located three or more pixels away from the first relative position along the horizontal direction or the vertical direction. ### Claim 10 (depends on 3) The method of claim 3, wherein the weighted average of the first set of predicted samples and the second set of predicted samples is calculated by applying weights for one of the plurality of subblocks that are derived according to a bi-prediction index that is a generalized bi-prediction (GBi) index for the one of the subblocks. ### Claim 11 (depends on 1) The method of claim 1, wherein the current block is a uni-predicted block. ### Claim 12 (depends on 1) The method of claim 1, wherein a de-blocking process is not performed on the current block. ### Claim 13 (depends on 1) The method of claim 1, further comprising: determining whether a stacked affine mode is enabled for the current block according to a flag, wherein the determining the second motion vectors for the plurality of subblocks, the obtaining the second set of predicted samples for the current block, and the obtaining the third set of predicted samples are performed based on the stacked affine mode being enabled, and the determining the second motion vectors for the plurality of subblocks, the obtaining the second set of predicted samples for the current block, and the obtaining the third set of predicted samples are not performed based on the stacked affine mode not being enabled. ### Claim 14 (depends on 13) The method of claim 13, wherein the flag indicates that the stacked affine mode is enabled, and the determining the second motion vectors for the plurality of subblocks, the obtaining the second set of predicted samples for the current block, and the obtaining the third set of predicted samples are not performed on any bi-predicted block. ### Claim 15 An apparatus, comprising: processing circuitry configured to: determine first motion vectors for a plurality of subblocks of a current block based on a first relative position in each subblock of the plurality of subblocks; determine second motion vectors for the plurality of subblocks based on a second relative position in each subblock of the plurality of subblocks; obtain a first set of predicted samples for the current block based on the first motion vectors of the plurality of subblocks; obtain a second set of predicted samples for the current block based on the second motion vectors of the plurality of subblocks; and obtain a third set of predicted samples for the current block based on the first set of predicted samples and the second set of predicted samples. ### Claim 16 (depends on 15) The apparatus of claim 15, wherein the first relative position is a center of each subblock. ### Claim 17 (depends on 15) The apparatus of claim 15, wherein the first relative position is a center of a first edge of each subblock, and the second relative position is a center of a second edge of each subblock. ### Claim 18 (depends on 15) The apparatus of claim 15, wherein the third set of predicted samples for the current block is obtained based on a weighted average of the first set of predicted samples and the second set of predicted samples, a first pixel in the first set of predicted samples for one of the subblocks is located at a first position in the one of the subblocks, a second pixel in the first set of predicted samples for the one of the subblocks is located at a second position in the one of the subblocks, the first position is closer to the first relative position of the one of the subblocks than the second position, and the weighted average of the first set of predicted samples and the second set of predicted samples is calculated by applying a first weight to the first pixel and a second weight to the second pixel, and the first weight being greater than the second weight. ### Claim 19 A non-transitory computer-readable medium storing instructions which when executed by a computer for video decoding cause the computer to perform: determining first motion vectors for a plurality of subblocks of a current block based on a first relative position in each subblock of the plurality of subblocks; determining second motion vectors for the plurality of subblocks based on a second relative position in each subblock of the plurality of subblocks; obtaining a first set of predicted samples for the current block based on the first motion vectors of the plurality of subblocks; obtaining a second set of predicted samples for the current block based on the second motion vectors of the plurality of subblocks; and obtaining a third set of predicted samples for the current block based on the first set of predicted samples and the second set of predicted samples. ### Claim 20 (depends on 19) The non-transitory computer-readable medium of claim 19, wherein the first relative position is a center of each subblock.