Abstract: A method of decoding video data includes determining, by a video decoder implemented in processing circuitry, a context initialization using a plurality of quantization parameters for a portion of a picture of video data decoded using temporal prediction. The method includes storing, by the video decoder, the context initialization with a single probability state for the plurality of quantization parameters. The method includes entropy decoding, by the video decoder, a set of syntax elements in a bitstream using the single probability state.

Abstract: An example device for decoding video data includes a memory for storing video data, and one or more processors implemented in circuitry and configured to construct an intra-prediction candidate list for a current chroma block of the video data indicating candidate intra-prediction modes for the current chroma block, wherein the intra-prediction candidate list indicates a subset of allowed luminance (luma) candidate intra-prediction modes, determine cost (e.g., sum of absolute transform difference (SATD)) values for each of the candidate intra-prediction modes in the intra-prediction candidate list for the current chroma block, and generate a prediction block for the current chroma block using one of the candidate intra-prediction modes indicated by the intra-prediction candidate list according to the cost values (e.g., the candidate intra-prediction mode having the lowest cost value).

Abstract: A video coder is configured to determine bi-directional motion vectors of a current block of the video data and determine that a condition is satisfied with respect to the current block based on each component of the bi-directional motion vectors of the current block being less than a threshold value. The video coder is further configured to, based on the condition being satisfied with respect to the current block, early terminate application of a motion vector refinement process to the bi-directional motion vectors of the current block. The video coder is further configured to determine a prediction block for the current block based on the bi-directional motion vectors of the current block and reconstruct the current block based on the prediction block for the current block.

Abstract: A video decoder can be configured to determine that a block of the video data is encoded using an adaptive color transform (ACT); determine that the block is encoded in a joint chroma mode, wherein for the joint chroma mode a single chroma residual block is encoded for a first chroma component of the block and a second chroma component of the block; determine a quantization parameter (QP) for the block; determine an ACT quantization parameter (QP) offset for the block based on the block being encoded using the ACT and encoded in the joint chroma mode; and determine an ACT QP for the block based on the QP and the ACT QP offset.

Abstract: A video coder selects a set of wide-angle intra prediction directions based on a size of a luma block of a picture having a YUV 4:2:2 chroma sampling format. Additionally, the video coder determines an intra prediction direction for the luma block. The intra prediction direction for the luma block is in the set of wide-angle intra prediction directions. The video coder also determines an intra prediction direction for a chroma block. The luma block is collocated in the picture with the chroma block. The chroma block has a different width/height ratio than the luma block. The intra prediction direction for the chroma block is guaranteed to have the intra prediction direction for the luma block. The video coder uses the intra prediction directions for the luma and chroma blocks to generate prediction blocks for the luma and chroma blocks, respectively.

Abstract: A video coder is configured to perform motion vector prediction to predict a motion vector for a block of video data. The motion vector prediction may use a motion vector predictor list that includes both adjacent and non-adjacent candidates relative to the current block. The video coder may divide spatial motion vector prediction candidates for a current block of video data into groups, add the spatial motion vector prediction candidates to a motion vector predictor list based on the groups, and decode a motion vector for the current block of video data based on the motion vector predictor list.

Abstract: An example device for decoding video data includes a memory configured to store the video data and one or more processors implemented in circuitry and coupled to the memory. The one or more processors are configured to determine a first distance index associated with a first geometric partition mode (GEO) angle for a first prediction unit (PU) of the video data to be 4. The one or more processors are configured to determine a first displacement value based on the first distance index, the first displacement value being indicative of a distance from a center of the first PU to a GEO split. The one or more processors are configured to decode the first PU based on the first GEO angle and the first displacement value. The first displacement value is half of a displacement value associated with a distance index of 2.

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: This disclosure describes example techniques that a video coder (e.g., video encoder or video decoder) may utilize to determine a block vector for a chroma block where the partition trees for the chroma component and the luma component are different (e.g., decoupled partition trees).

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: A method of decoding video data includes receiving a plurality of blocks of video data, wherein each block of the plurality of blocks is encoded using a respective affine motion model of a plurality of affine motion models, and decoding the plurality of blocks of video data using the same affine motion field derivation process for each of the plurality of affine motion models.

Abstract: Systems and techniques for intra-block copy (IBC) prediction in processing video data include the use of one or more virtual search areas (VSAs) which can be generated to include one or more references to one or more pixels stored in a physical memory. The one or more VSAs can provide references to additional reconstructed sample values that are derived from previously decoded blocks without incurring physical memory use for storage of the additional reconstructed samples. A search area for performing the IBC prediction for a current block of the video data can be extended to include the one or more VSAs. Extending the search area to include the one or more VSAs provides the IBC prediction with additional search area for finding one or more prediction blocks or prediction samples without having to utilize physical memory to store the additional reconstructed samples from previously decoded blocks.

Abstract: An example device for decoding video data includes a memory configured to store video data; and a processor implemented in circuitry and configured to decode a truncated unary codeword representing a multiple transform (MT) scheme for a current block of the video data to determine the MT scheme; apply the MT scheme to transform coefficients of the current block to produce residual data for the current block of video data; and decode the current block using the residual data. The MT scheme may include a plurality of transforms, such as a horizontal transform and a vertical transform, a primary transform and a second transform, or any combination of separable and/or non-separable transforms. Thus, a single truncated unary codeword may represent the entire MT scheme, that is, each of a plurality of transforms of the MT scheme.

Abstract: A method of decoding video data, including receiving an encoded block of video data that was encoded using an inter-prediction mode, receiving one or more syntax elements indicating a motion vector difference (MVD) associated with the encoded block of video data, determining a current MVD precision, from three or more MVD precisions, for the one or more syntax elements indicating the MVD, wherein the three or more MVD precisions include an N-sample MVD precision, where N is an integer indicating a number of samples indicated by each successive codeword of the one or more syntax elements indicating the MVD, and wherein N is greater than 1, decoding the one or more syntax elements indicating the MVD using the determined current MVD precision, and decoding the encoded block of video data using the decoded MVD.

Abstract: Embodiments include methods and apparatuses for decoding video data including receiving an encoded video bitstream that forms a representation of a coded picture of the video data and determining a partitioning of the coded picture of the video data into a plurality of coded unit. The partitioning may be according to a first tree structure and the plurality of coded units including a leaf node in the first tree structure. A method may further include determining that a residual block of the leaf node is recursively split into a plurality transform units according to a second tree structure.

Abstract: Codecs that use larger blocks may have larger boundary regions that may benefit from filtering. In some embodiments, the deblocking filter determines filters and/or a number of samples of the block to be filtered based on block dimensions. For example, In one embodiment, deblocking filter parameters for the video block are determined based on at least one dimension of the size of the video block. The filter parameters include a filter to be applied or a number of pixels along a boundary with a neighboring block to which the filter is to be applied determined based on the at least one dimension.

Abstract: Methods and devices for decoding including a processor configured to determine which picture is a collocated picture, and determine a location of an associated block of the video data in the collocated picture that corresponds to the current block of video data in the current coding picture, based on using previously decoded blocks in the current coding picture to find an initial motion vector between the associated block in the collocated picture and the current block in the current coding picture, where the associated block of the video data includes at least one first derived motion vector. The processor configured to determine at least one second derived motion vector associated with the current block in the current coding picture, when the initial motion vector points to the collocated picture, based on the at least on first derived motion vector associated with the associated block in the collocated picture.

Abstract: A video decoder can be configured to determine, for a block of video data encoded in a geometric partition mode, an angle for the block for the geometric partition mode; determine a separation line displacement relative to a center of the block for the geometric partition mode; partition the block into first and second partitions based on the angle and the separation line displacement; determine first predictive samples for the block using a motion vector for the first partition and second predictive samples for the block using a motion vector for the second partition; determine a power-of-2 number based on the angle for the block; determine weighting values based on the power-of-2 number; perform a blending operation on the first predictive samples and the second predictive samples based on the weighting values to determine a prediction block for the block.

Abstract: An example device for coding video data includes a memory configured to store 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 coding unit (CU) of the video data is an affine mode CU with adaptive motion vector resolution (AMVR). The one or more processors are configured to, based at least in part on the CU being an affine mode CU with AMVR, select a motion vector difference (MVD) resolution for the CU equal to a ? luma sample resolution. The MVD resolution is selected from among a ¼ luma sample resolution, an integer luma sample resolution, and the ? luma sample resolution. The one or more processors are further configured to code the CU based on the MVD resolution.

Abstract: A video coder is configured to use bi-directional optical flow (BDOF) to determine, based on a first reference picture and a second reference picture, a prediction block for a current block of a current picture of the video data. The first reference picture is a first picture order count (POC) distance from the current picture. The second reference picture is a second POC distance from the current picture. The first POC distance must be equal to the second POC distance for BDOF to be used to determine the prediction block for the current block. The video coder codes, according to the video coding standard, the current block based on the prediction block for the current block.