Abstract: Systems and techniques for processing video data include a pruning processes for motion vector candidate list construction. An illumination compensation flag of a potential motion information candidate to be added to a motion information candidate list can include motion information associated with a block of video data, where the motion information can include a motion vector and an illumination compensation flag. The motion information can be compared with stored motion information in the motion information candidate list, where the stored motion information can include at least one stored motion vector and associated stored illumination compensation flag. When the motion vector matches the stored motion vector, the pruning process can include not adding the motion vector to the motion information candidate list, and updating the stored illumination compensation flag based on a value of the illumination compensation flag and a value of the stored illumination compensation flag.

Abstract: A video decoder is configured to, for a group of video blocks of the video data, determine a number of merged groups for a plurality of classes is equal to one merged group; receive a first flag indicating that filter coefficient information for at least one merged group is not coded in the video data; receive for the one merged group, a second flag, wherein a first value for the second flag indicates that filter coefficient information mapped to the one merged group is coded in the video data, and wherein a second value for the second flag indicates that the filter coefficient information mapped to the one merged group is all zero values; determine the second flag is equal to the second value; and determine one or more filters from the set of filters using the all zero values.

Abstract: A video decoder can be configured to determine a predicted luma quantization parameter (QP) for a luma component of a coding unit; receive, in the bitstream of encoded video data, first syntax indicating a luma delta QP value for the luma component; determine a QP value for the luma component based on the predicted luma QP and the luma delta QP value; determine a predicted chroma QP for a chroma component of the coding unit; receive, in the bitstream of encoded video data, second syntax indicating a chroma delta QP value for the chroma component of the coding unit; and determine a QP value for the chroma component of the coding unit based on the predicted chroma QP and the chroma delta QP value.

Abstract: Embodiments include methods and apparatus for encoding and decoding video data. In particular, embodiments include methods and apparatus for encoding and decoding video using a combined inter/intra prediction mode. In one such embodiment, the inter prediction is performed using a equal weighted bi-prediction mode determined using a merge mode that would otherwise indicate a non-equal weighted bi-prediction.

Abstract: Techniques and systems are provided for processing video data. For example, a current block of a picture of the video data can be obtained for processing by an encoding device or a decoding device. A parameter of the current block can be determined. Based on the determined parameter of the current block, at least one or more of a number of rows of samples or a number columns of samples in a template of the current block and at least one or more of a number of rows of samples or a number columns of samples in a template of a reference picture can be determined. Motion compensation for the current block can be performed. For example, one or more local illumination compensation parameters can be derived for the current block using the template of the current block and the template of the reference picture.

Abstract: A device for decoding video data can be configured to receive a syntax element indicating a maximum block size for a transform skip mode; determine a maximum block size for a block-based delta pulse code modulation (BDPCM) mode based on the syntax element; and decode block of video data based on the determined maximum block size for the BDPCM mode.

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: A video encoder and a video decoder are configured to store and modify motion vectors to an effective range based on one or more of a motion vector precision and a motion vector bit-depth. For example, a video decoder may determine a first motion vector for a first block of video data, scale the first motion vector to produce a scaled motion vector, determine a first effective motion vector range based on a first bit-depth of the first motion vector and a first motion vector precision of the first motion vector, clip the scaled motion vector to a first effective motion vector range to produce a first clipped motion vector, and decode the first block of video data using the first clipped motion vector.

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: 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 includes a memory configured to store video data; and one or more processors implemented in circuitry and configured to: construct a motion vector predictor candidate list for a current block of the video data, the motion vector predictor candidate list identifying one or more blocks that are non-adjacent to the current block, each of the non-adjacent blocks being in a coding tree unit (CTU) including the current block or a line buffer including the current block; select a motion vector predictor from one of the blocks that is non-adjacent to the current block and in the motion vector predictor candidate list; and code motion information of the current block using the motion vector predictor.

Abstract: Provided are systems, methods, and computer-readable medium for encoding and decoding video data. In various examples, a coding device can include multiple luma QP and chroma QP relationship tables. In performing quantization or inverse quantization one video data being encoded or decoded, respectively, the coding device can select a table. The table can be selected based on, for example, a slice type, a prediction mode, and/or a luminance value, among other factors. The coding device can then use the luma QP value to look up a chroma QP value from the table. The luma QP and chroma QP values can then be used in quantization or inverse quantization.

Abstract: A video coder may reconstruct a current picture of video data. A current region of the current picture is associated with a temporal index indicating a temporal layer to which the current region belongs. Furthermore, for each respective array of a plurality of arrays that correspond to different temporal layers, the video coder may store, in the respective array, sets of adaptive loop filtering (ALF) parameters used in applying ALF filters to samples of regions of pictures of the video data that are decoded prior to the current region and that are in the temporal layer corresponding to the respective array or a lower temporal layer than the temporal layer corresponding to the respective array. The video coder determines, based on a selected set of ALF parameters in the array corresponding to the temporal layer to which the current region belongs, an applicable set of ALF parameters.

Abstract: An example device for coding video data includes a memory configured to store video data, and one or more processors implemented in circuitry and configured to code a first motion vector difference (MVD) representing a difference between a first motion vector of a current block of video data predicted using affine prediction and a first motion vector predictor (MVP) for the first motion vector, predict a second MVD from the first MVD for a second motion vector of the current block, and code the current block using affine prediction according to the first motion vector and the second motion vector. Predicting the second MVD from the first MVD in this may reduce bitrate of a bitstream including coded video data, as well as improve processing efficiency.

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 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: This disclosure describes gradient-based prediction refinement. A video coder (e.g., video encoder or video decoder) determines one or more prediction blocks for inter-predicting a current block (e.g., based on one or more motion vectors for the current block). In gradient-based prediction refinement, the video coder modifies one or more samples of the prediction block based on various factors such as displacement in a horizontal direction, the horizontal gradient, a displacement in the vertical direction, and a vertical gradient. This disclosure provides for gradient-based prediction refinement where a precision level of the displacement (e.g., at least one of the horizontal or vertical displacement) is unified (e.g., the same) for different prediction modes (e.g., including an affine mode and a bi-directional optical flow (BDOF) 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 device for coding video data includes a memory configured to store video data; and one or more processors comprising circuitry and configured to generate a prediction block for a current block of video data; apply a bilateral filter to the prediction block to generate a filtered prediction block for the current block, wherein to apply the bilateral filter, the processor is configured to determine weighting values to apply to neighboring pixels to a current pixel of the prediction block to be filtered according to values of the neighboring pixels; and code the current block using the filtered prediction block.

Abstract: A video coder is configured to code video data using triangular partitions. The video coder may determine a size of a block of video data, and disable a partitioning mode that includes triangular prediction units based on the size of the block of video data, wherein disabling the partitioning mode that includes triangular prediction units removes the partitioning mode from available coding modes. For example, the video coder may disable the partitioning mode that includes triangular prediction units in the case that the width or the height of the block is larger than a threshold. The video coder may then code the block of video data with one or more of the available coding modes.