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 methods of filtering video data using a plurality of filters are disclosed. In an embodiment, a method includes receiving and decoding a plurality of filters embedded in a video data bitstream at a video decoder. The method includes selecting, based on information included in the video data bitstream, a particular filter of the plurality of filters. The method further includes applying the particular filter to at least a portion of decoded video data of the video data bitstream to produce filtered decoded video data.

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: Systems and methods of filtering video data using a plurality of filters are disclosed. In an embodiment, a method includes receiving and decoding a plurality of filters embedded in a video data bitstream at a video decoder. The method includes selecting, based on information included in the video data bitstream, a particular filter of the plurality of filters. The method further includes applying the particular filter to at least a portion of decoded video data of the video data bitstream to produce filtered decoded video data.

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 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: 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: Techniques related to derivation of motion vectors of a first color component (e.g., chroma component) from motion vectors of a second color component (e.g., luma component) are described. A video coder (e.g., video encoder or video decoder), for a CU coded in affine mode with 4:4:4 color format, may determine a motion vector for each sub-block of the luma block, and determine a motion vector for each sub-block of the chroma block based only on the motion vector for each co-located (also called collocated) sub-block of the luma block. However, for another CU coded in affine mode but with a color format other than 4:4:4 (e.g., 4:2:2 or 4:2:0), the video coder may determine a motion vector for each sub-block of the chroma block based on an average of two or more motion vectors of sub-blocks of the luma block.

Abstract: An example device for decoding video data includes a memory for storing the video data and one or more processors implemented in circuitry and communicatively coupled to the memory. The one or more processors are configured to determine whether a first coding unit (CU) is a skip mode CU, and based on the first CU not being a skip mode CU, determine whether the first CU is encoded using one of an intra mode or a palette mode. The one or more processors are also configured to determine whether the first CU is encoded using the palette mode based on the first CU being encoded using one of the intra mode or the palette mode. The one or more processors are also configured to decode the first CU based on the determination of whether the first CU is encoded using the palette mode.

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: An example device for coding video data determines for a first block of the video data whether to use a sub-block merge mode. Based on the determination not to use the sub-block merge mode for the first block, the device determines whether to use a merge mode with blending for the first block. Based on the determination to use the merge mode with blending for the first block, the device codes the first block with the merge mode with blending.

Abstract: An example device for coding video data includes a memory configured to store video data; and one or more processing units implemented in circuitry and configured to: store motion information for a first coding tree unit (CTU) line of a picture in a first history motion vector predictor (MVP) buffer of the memory; reset a second history MVP buffer of the memory; and after resetting the second history MVP buffer, store motion information for a second CTU line of the picture in the second history MVP buffer, the second CTU line being different than the first CTU line. Separate threads of a video coding process executed by the one or more processors may process respective CTU lines, in some examples.

Abstract: An example video coding device is configured to: code a first set of motion information for a current block of video data partitioned into a first partition and a second partition according to a non-rectangular partition mode, the first set of motion information referring to a reference picture list and being associated with the first partition; after coding the first set of motion information, code a second set of motion information for the current block referring to the reference picture list and that is associated with the second partition; in response to the first set of motion information and the second set of motion information both referring to the reference picture list, store the second set of motion information for the current block; and predict subsequent motion information of a subsequent block of the video data that neighbors the current block using the stored second set of motion information.

Abstract: An example device for filtering a decoded block of video data includes one or more processors implemented in circuitry and configured to decode a current block of a current picture of the video data, select a filter (such as an adaptive loop filter) to be used to filter pixels of the current block, calculate a gradient of at least one pixel for the current block, select a geometric transform to be performed on one of a filter support region or coefficients of the selected filter, wherein the one or more processors are configured to select the geometric transform that corresponds to an orientation of the gradient of the at least one pixel, perform the geometric transform on either the filter support region or the coefficients of the selected filter, and filter the at least one pixel of the current block using the selected filter after performing the geometric transform.

Abstract: An example method of decoding video data includes obtaining, from a coded video bitstream and for a current block of the video data, an indication of an intra-prediction mode that identifies an initial predictive block; filtering, in parallel, samples in a current line of a plurality of lines of the initial predictive block based on filtered values of samples in a preceding line of the plurality of lines and unfiltered values of samples in the current line to generate filtered values for samples for the current line; and reconstructing, using intra prediction, values of samples of the current block based on the filtered values of the samples of the current initial predictive block and residual data for the current block that represents a difference between the filtered values of the samples of the current initial predictive block and the values of samples of the current block.

Abstract: A device for decoding video data includes a memory configured to store video data; and one or more processors implemented in circuitry and configured to: determine a deterministic bounding box from which to retrieve reference samples of reference pictures of video data for performing decoder-side motion vector derivation (DMVD) for a current block of the video data; derive a motion vector for the current block according to DMVD using the reference samples within the deterministic bounding box; form a prediction block using the motion vector; and decode the current block using the prediction block.

Abstract: Systems and techniques are provided for processing video data. For example, the systems and techniques can include obtaining a current picture of video data and obtaining reference pictures for the current picture from the video data. A merge mode candidate can be determined for the current picture. First and second motion vectors can be identified for the merge mode candidate. A motion vector search strategy can be selected for the merge mode candidate from a plurality of motion vector search strategies. The selected motion vector search strategy can be associated with one or more constraints corresponding to at least one of the first motion vector or the second motion vector. The selected motion vector search strategy can be used to determine refined motion vectors based on the first motion vector, the second motion vector, and the reference pictures. The merge mode candidate can be processed using the refined motion vectors.

Abstract: A video encoder may encode a picture of video data using merge estimation regions (MERs). The video encoder may determine merge candidate lists in parallel for coding units within a MER. The video encoder may also partition the picture of video data into coding units according to a constraint, wherein the constraint specifies that the partitioning is constrained such that, for each MER containing one or more coding units, the one or more coding units are completely in the MER, and for each coding unit containing one or more MERs, the MERs are completely in the coding unit.

Abstract: An example method includes determining, for each respective coding block of a plurality of coding blocks of a current coding tree unit (CTU) of video data in a current picture of video data, a respective search area of a plurality of respective search areas, wherein at least one of the plurality of search areas includes samples of the current picture located outside of the current CTU, and wherein at least one of the plurality of search areas does not include samples of the current picture located outside of the current CTU; selecting, for each respective coding block and from within the respective search area for the respective coding block, a respective predictor block of a plurality of predictor blocks; and reconstructing samples of each respective coding block based on samples included in a corresponding predictor block in the plurality of predictor blocks.

Abstract: An example method includes determining, without receiving explicit signaling, whether motion compensation for a current block of a current picture of video data is to be performed using a four-parameter affine motion model (AMM) defined by two motion vectors (MVs) or using a six-parameter AMM defined by three MVs; deriving values of predictors for MVs of the AMM of the current block; decoding a representation of differences between the values of the MVs of the AMM for the current block and the values of the predictors; determining the values of the MVs of the AMM for the current block from the values of the predictors and the decoded differences; determining, based on the determined values of the MVs of the AMM for the current block of video data, a predictor block of video data; and reconstructing the current block based on the predictor block.