Abstract: A video coder can be configured to code video data by determining a first block size threshold for a block of video data; determining a second block size threshold, wherein the second block size threshold is smaller than the first block size threshold; partitioning the block of video data into smaller sub-blocks; in response to determining that a first partition of the partitioned block is smaller or equal to the first block size threshold, determining that blocks within the partition belong to a parallel estimation area; and in response to determining that a second partition of the partitioned block is smaller or equal to the second block size threshold, determining that blocks within the second partition belong to an area for a shared candidate list.

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 select two or more subblocks of one or more blocks of video data and generate an affine motion model for a current block of video data using a subblock motion vector from each of the two or more subblocks as control-point motion vectors for the current block. The one or more processors are further configured to determine one or more prediction blocks based on the affine motion model and predict the current block with the one or more prediction blocks.

Abstract: An example video coding system may determine a first coding mode for a first block of video data of a plurality of blocks of video data in a processing area. The video coding system may compare a characteristic of the processing area to a threshold. The video coding system may determine whether to enable or disable use of a second coding mode for the remainder of the plurality of blocks of video data in the processing area based on the comparison. The video coding system may code the first block based on the first coding mode and code at least one block of the remainder of the plurality of blocks of video data based on the comparison.

Abstract: The present disclosure provides various techniques related to adaptive loop filtering (ALF), and particular to geometry transformation-based ALF (GALF). In an aspect, a method for decoding video data includes receiving an encoded bitstream having coded video data from which reconstructed video units are generated, identifying multiple filter supports for the reconstructed video units, and filtering the reconstructed video units using the respective multiple filter supports to produce a decoded video output. Another method includes enabling block-level control of ALF of chroma components for the reconstructed video units, performing, for the reconstructed video units, the block-level ALF for the chroma components when ALF is enabled for one video block and skip performing the block-level ALF for the chroma components when ALF is disabled for another video block, and generating, based on the enabled block-level control of ALF, a decoded video output.

Abstract: A video coder may be configured to determine a partitioning for a picture of video data using dual tree partitioning. The video coder may receive a picture of video data, determine a partitioning for the picture of video data using dual tree partitioning for luma blocks and chroma blocks based on a minimum quadtree size, wherein a maximum value for the minimum quadtree size is equal to a threshold used for inferring a quadtree split, and code the partitioned picture.

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: A video coder is configured to code a block of video data using bi-prediction with bi-directional optical flow. The video coder may determine an offset using bi-directional optical flow and may add the offset to prediction samples determined from the bi-prediction. In one example, the video coder code a current block of video data using bi-prediction and bi-directional optical flow, wherein the bi-directional flow does not include one or more of a rounding operation or a division by 2 in an offset calculation. Additionally, the video coder may perform a motion vector refinement calculation for the bi-directional flow, wherein the motion vector refinement calculation is compensated to account for the offset calculation not including the division by 2.

Abstract: An example device for coding video data may include a memory configured to store a current block of the video data and one or more processors implemented in circuitry coupled to the memory. The one or more processor may be configured to determine delta motion vectors from control point motion vectors of a neighboring block of a current block. The one or more processors may also be configured to clip the delta motion vectors to a predefined range. The one or more processors may also be configured to code the current block of video data using the clipped delta motion vectors.

Abstract: A video decoder selects a source affine block. The source affine block is an affine-coded block that spatially neighbors a current block. Additionally, the video decoder extrapolates motion vectors of control points of the source affine block to determine motion vector predictors for control points of the current block. The video decoder inserts, into an affine motion vector predictor (MVP) set candidate list, an affine MVP set that includes the motion vector predictors for the control points of the current block. The video decoder also determines, based on an index signaled in a bitstream, a selected affine MVP set in the affine MVP set candidate list. The video decoder obtains, from the bitstream, motion vector differences (MVDs) that indicate differences between motion vectors of the control points of the current block and motion vector predictors in the selected affine MVP set.

Abstract: A method of processing video data includes classifying, by processing circuitry, luma samples of a neighboring luma block of a reference block and luma samples of a neighboring luma block of a current block into a plurality of groups and deriving, by the processing circuitry, one or more local illumination compensation parameters for each group of the plurality of groups to generate a plurality of local illumination compensation parameters for the current block. The method further includes deriving, by the processing circuitry, a plurality of linear models between the neighboring luma block of the reference block and the neighboring luma block of the current block using the plurality of local illumination compensation parameters for the current block and generating, by the processing circuitry, a prediction block using the plurality of linear models.

Abstract: A device for coding video data is configured to determine that a current block of video data is coded using an intra prediction mode; add an intra prediction mode of a first neighboring block of the current block to a most probable mode candidate list for the current block; add an intra prediction mode for a second neighboring block of the current block to the most probable mode candidate list for the current block; add an intra prediction mode for a third neighboring block of the current block to the most probable mode candidate list for the current block; and code the current block of video data using an intra prediction mode.

Abstract: A device for coding video data may determine whether a switchable interpolation filter (SIF) index value of a first motion vector (MV) component of a pairwise average motion vector predictor (MVP) is equal to a SIF index value of a second MV component of the pairwise average MVP. Based on the SIF index value of the first MV component being equal to the SIF index value of the second MV component, the device may set the SIF index of the pairwise average MVP to be equal to the SIF index of the first MV component. The device may code the video data based on the SIF index value of the pairwise average MVP.

Abstract: A video encoder and video decoder are configured to perform an ultimate motion vector expression (UMVE)-based pruning method which is used to prune motion vectors in a motion vector candidate list. The video encoder and video decoder may add one or more motion vector candidates to a candidate list for motion vector prediction for a current block of the video data, determine whether to add a next motion vector candidate to the candidate list based on a UMVE candidate of a respective candidate of the one or more candidates, and encode/decode the current block of the video data using the candidate list.

Abstract: A device and method for coding video data determines a spatial-temporal motion vector predictor (STMVP) so that the STMVP does not need to be motion vector scaled. The device may determine a candidate list. The device may then determine which candidates in the candidate list have the same reference picture. The device may then generate the STMVP based on the candidates in the candidate list determined to have the same reference picture. The device may then code a current block of video data using the STMVP.

Abstract: In one example, a device includes a memory configured to store video data, and one or more processing units implemented in circuitry configured to construct a plurality of filters for classes of blocks of a current picture of the video data, wherein to construct the plurality of filters, the one or more processing units are configured to generate a plurality of sets of filter coefficients, and for a subset of the plurality of filters, determine respective indexes that identify one of the sets of filter coefficients for the corresponding filter of the subset; decode a current block of the current picture, determine a class for the current block, select a filter of the plurality of filters that corresponds to the class for the current block, and filter at least one pixel of the current block using the selected filter.

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 device for decoding video data can be configured to store a table of history-based motion vector predictors (HMVPs); determine motion information for a first block of the video data; add the motion information for the first block to the table of HMVPs in response to determining that the first block is located at a bottom-right corner of a motion estimation region (MER); and use the table of HMVPs to decode a second block of the video data.

Abstract: Systems and techniques for processing video data include a history-based motion vector predictor (HMVP) table with two or more HMVP candidates, where a first entry of the HMVP table associated with a first index value includes a first HMVP candidate and a second entry of the HMVP table associated with a second index value includes a second HMVP candidate, the first index value being lower than the second index value. For an advanced motion vector prediction (AMVP) candidate list, one or more HMVP candidates from the HMVP table are selected in a reverse order, where the second HMVP candidate is selected before the first HMVP candidate according to the reverse order. The selected one or more HMVP candidates are added to the AMVP candidate list. The AMVP candidate list can be used to perform AMVP for the one or more blocks of video data.

Abstract: An example method for coding video data includes determining, for a current block of a current picture of video data, the current block coded using an intra block copy (IBC) mode, whether a motion vector (MV) for identifying a prediction block for the current block is a legal MV. The example method further includes, responsive to determining that the MV is not a legal MV, reconstructing samples of the current block using an alternative processing method.

Abstract: A video encoder and video decoder are configured to encode and decode blocks of video data using affine motion prediction. Affine motion prediction may include predicting control point motion vectors using an affine advanced motion vector prediction (AMVP) motion vector predictor list. The video encoder and video decoder may be configured to construct the affine AMVP motion vector predictor list of candidate control point motion vectors for the block of video data, wherein the affine AMVP motion vector predictor list includes one or more affine motion vector predictors that have all control point motion vectors equal to a designated motion vector.