Abstract: A video coder may determine a motion vector of a non-adjacent block of a current picture of the video data. The non-adjacent block is non-adjacent to a current block of the current picture. Furthermore, the video coder determines, based on the motion vector of the non-adjacent block, a motion vector predictor (MVP) for the current block. The video coder may determine a motion vector of the current block. The video coder may also determine a predictive block based on the motion vector of the current block.

Abstract: A method of coding video data, including coding a first block of video data using affine motion compensation prediction, updating a history-based motion vector prediction table using one or more motion vectors from one or more blocks that spatially neighbor the first block, determining a motion vector for a second block of video data using the history-based motion vector prediction table, and coding the second block of video data using the determined motion vector.

Abstract: An example method of coding video data includes selecting, by one or more processors a sub-set of a plurality of neighboring samples of a current block in a current picture, wherein the plurality of neighboring samples includes a row of samples adjacent to a top row of the current block in the current picture and a column of samples adjacent to a left column of the current block in the current picture; deriving, by the one or more processors and based on the sub-set of the plurality of neighboring samples in the current picture, local illumination compensation (LIC) parameters for the current block; and performing, by the one or more processors and based on the LIC parameters, LIC on samples of the current block to generate compensated samples of the current block.

Abstract: A video coder is configured to form, in a symmetric motion vector difference mode, a List 0 (L0) base vector using a L0 Advanced Motion Vector Prediction (AMVP) candidate list and a List 1 (L1) base vector using a L1 AMVP candidate list; determine a refined L0 motion vector and a refined L1 motion vector by performing a decoder-side motion vector refinement process that refines the L0 base vector and the L1 base vector; and use the refined L0 motion vector and the refined L1 motion vector to determine a prediction block for a current block of a current picture of the video data.

Abstract: In one example, a method of coding video data includes responsive to determining to predict a current block of a current picture of video data using intra block copy (IBC), generating a motion vector (MV) candidate list for the current block, wherein generating the MV candidate list comprises: determining one or more history-based motion vector prediction (HMVP) candidates; and including, as a last candidate in the MV candidate list, an HMVP candidate of the one or more HMVP candidates; selecting, from the MV candidate list, a particular MV candidate that identifies a predictor block in the current picture; and reconstructing pixels of the current block based on pixels of the predictor block.

Abstract: A video coder may be configured to determine to use a decoder side motion vector refinement process, including bi-lateral template matching, based on whether or not weights used for bi-predicted prediction are equal or not. In one example, decoder side motion vector refinement may be disabled when weights used for bi-predicted prediction are not equal.

Abstract: 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.

Abstract: This disclosure describes techniques for enabling very precise on/off control of two or more different decoder-side refinement tools. Rather than merely allowing or enabling these tools for an entire video sequence of video data, this disclosure describes techniques for enabling or disabling different decoder-side refinement tools for subsets (or portions) of a video sequence.

Abstract: An example device for coding video data is configured to determine that a block of the video data includes a plurality of sub-blocks, each of the sub-blocks having respective motion information referring to respective reference blocks in a reference picture in a memory, determine a single reference block of the reference picture, the single reference block including each of the respective reference blocks, wherein determining the single reference block comprises: determine four corner sub-blocks of the block included in the plurality of sub-blocks; and determine the single reference block according to the respective motion information for the four corner sub-blocks such that corners of the single reference block correspond to corners of the respective reference blocks of the four corner sub-blocks, retrieve data of the single reference block from the reference picture, and predict the sub-blocks from the respective reference blocks using the data of the single reference block.

Abstract: A video coder may determine a partitioning of a current picture of the video data into a plurality of partition blocks. The video coder may determine a plurality of processing areas in a unit in the current picture having sizes, where an average size of all of the plurality of processing areas in the unit is greater than or equal to a parameter N, and where determining the plurality of processing areas in the unit includes defining a processing area of the plurality of processing areas that has a size that fits two or more adjacent partition blocks of the plurality of adjacent blocks. The video coder may independently code coding units (CUs) within the processing area having the merged two or more adjacent partition blocks.

Abstract: An example device includes a memory to store the video data, and processing circuitry in communication with the memory. The processing circuitry is configured to compare a value of a dimension of a current block of the stored video data to a value of a corresponding dimension of a neighboring block of the current block to obtain a relative dimension value. The processing circuitry is further configured to determine, based on the relative dimension value, that the current block is to be partitioned according to a prediction tree (PT) portion of a multi-type tree-based partitioning scheme. The PT portion comprises partitioning according to one of a binary tree structure or a center-side triple tree structure. The processing circuitry is further configured to partition, based on the determination, the current block according to the PT portion, to form a plurality of sub-blocks.

Abstract: An example method includes decoding, from a coded video bitstream, an explicitly defined scaling list; determining, based on values of one or more syntax elements decoded from a sequence parameter set (SPS) of the coded video bitstream, a set of block types to which the explicitly defined scaling list is eligible for application; and applying the explicitly defined scaling list to a block included in the set of block types.

Abstract: A video coding device, such as a video encoder or video decoder, may determine that a block of video data has at least one of a width less than 8 pixels, a height less than 8 pixels, or the width and the height being equal to 8 pixels; in response, determine that the block is not coded using decoder-side motion vector refinement (DMVR); and code the block without performing DMVR for the block. The video coding device may determine that a second block of video data has a size of at least 8×N or N×8, wherein N is an integer value greater than 8, in response to determining that the second block of video data has the size of at least 8×N or N×8, and then determine whether to code the second block using DMVR.

Abstract: A video encoder and video decoder are configured to determine a partitioning for a picture of video data based on a virtual pipeline data unit (VPDU) size. For example, the video encoder and video decoder may determine a maximum ternary tree size to be in the range of a minimum allowed block size to a minimum of the VPDU size and a maximum coding tree unit (CTU) size, and/or determine a minimum quadtree size to be in the range of a minimum allowed block size to a minimum of the VPDU size and the maximum CTU size.

Abstract: An example method includes encoding, in a video bitstream, a first syntax element specifying whether affine model based motion compensation is enabled; based on affine model based motion compensation being enabled, encoding, in the video bitstream, a second syntax element specifying a maximum number of subblock-based merging motion vector prediction candidates, wherein a value of the second syntax element is constrained based on a value other than a value of the first syntax element; and encoding a picture of the video data based on the maximum number of subblock-based merging motion vector prediction candidates.

Abstract: Systems and techniques for improving costs and efficiency in affine motion prediction of a current block includes storing motion information of previously coded block in a line buffer or one or more local buffers of a coding unit such as coding tree unit (CTU). The line buffer can store motion information of a line of coding blocks located at a boundary of the CTU, while the local buffers can be utilized for storing motion information of coding blocks located anywhere in the CTU. The utilization of the line buffer can be improved by limiting the number of motion vectors of a neighboring block stored in the line buffer and obtaining remaining motion vectors from an additional block when available. The utilization of local buffers can be improved by restricting a size of neighboring blocks whose motion information is stored in the local buffers.

Abstract: A video decoder configured to generate a first merge candidate list for a first block; determine that the first block is coded in a merge mode with motion vector differences; in response to determining that a maximum number of entries for the first merge candidate list is equal to 1, infer a value of a first instance of a flag to be equal to a first value, wherein the first value for the flag indicates that the first block is to be decoded using a first entry in the first merge candidate list; receive first motion vector difference information; determine first motion information for predicting the first block based on candidate motion information included in the first entry of the first merge candidate list and the first motion vector difference information; and decode the first block using the first motion information.

Abstract: A device for processing video data includes a memory configured to store video data and one or more processors implemented in circuitry. The one or more processors are configured to generate a first weighting factor for a first reference picture in a first picture list using a second weighting factor for a second reference picture in a second picture list. The one or more processors are further configured to generate prediction information for a current block of video data using the first weighting factor and the second weighting factor.

Abstract: A device for processing video data includes a memory configured to store video data and one or more processors implemented in circuitry. The one or more processors are configured to generate a coding unit for chroma components of a block of video data. The one or more processors are configured to split the coding unit for chroma components into a first triangle-shaped partition and a second triangle-shaped partition. The one or more processors are configured to apply pixel blending using a set of weights for a YUV 4:2:0 format to generate a predicted block for the chroma components of the block of video data when the one or more processors generate the coding unit for chroma components in the YUV 4:2:0 format and when the one or more processors generate the coding unit for chroma components in a YUV 4:4:4 format.

Abstract: Techniques are described for constructing motion vector predictor lists based on spatially neighboring blocks and collocated blocks. A method of coding video data includes, for a first block, in a first picture having a left-to-right coding order, constructing a first motion vector predictor list, wherein a first entry in the first motion vector predictor list is based on motion vector information of a left neighboring block to the first block, coding the first block in the first picture based on the first motion vector predictor list, for a second block, in a second picture having a right-to-left coding order, constructing a second motion vector predictor list, wherein a first entry in the second motion vector predictor list is based on motion vector information of a right neighboring block to the second block, and coding the second block in the second picture based on the second motion vector predictor list.