Abstract: A video coder may be configured to determine to use decoder side motion vector refinement and/or bi-directional optical flow based on the status of reference pictures associated with a block. In one example, a video decoder may determine whether decoder side motion vector refinement is enabled for a first block of video data based on whether a first reference picture from a first reference picture list is a short-term reference picture and whether a second reference picture from a second reference picture list is a short-term reference picture, and may then decode the first block of video data based on the determination.

Abstract: An example device for coding video data includes a processor configured to construct a motion vector predictor list for a current block of video data. The processor adds motion vectors for a first set of blocks that immediately neighbor the current block to the motion vector predictor list. The processor determines whether motion vectors for a second set of blocks that are separated from the current block by one or more blocks are duplicates of motion vectors in the motion vector predictor list, and if not, adds the motion vectors to the motion vector predictor list. The processor inter prediction codes the current block with a motion vector and codes the motion vector using the motion vector predictor list. The processor may further use a temporal motion vector as a motion vector predictor for the motion vector.

Abstract: Embodiments include systems and methods of generating merge candidates for an inter-prediction mode of a video block. In particular, embodiments include methods of generating spatial-temporal motion vector predictor candidates. Embodiments may include video encoders and video decoders.

Abstract: A method of decoding video data comprising performing a prediction process for one or more neighboring blocks of video data that are neighboring a current block of video data to obtain prediction pixel values for neighboring pixels of the current block of video data, deriving a template for the current block of video data using the prediction pixel values, performing a decoder-side motion vector derivation technique using the derived template to derive a motion vector for the current block of video data, and decoding the current block of video data using the derived motion vector.

Abstract: A method of decoding and encoding video data includes constructing a motion vector candidate list for the current block of video data based on the motion information from the neighboring blocks relative to the current block determined to include motion information, and adaptively ordering the constructed motion vector candidate list for the current block of video data based on at least one weight among a plurality of weights associated with motion information included in each neighboring block determined to include motion information.

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 pre-defined set of weights for template matching based motion compensation are also obtained. A plurality of metrics associated with one or more spatially neighboring samples of the current block and one or more spatially neighboring samples of at least one reference frame are determined. A set of weights are selected from the pre-defined set of weights to use for the template matching based motion compensation. The set of weights is determined based on the plurality of metrics. The template matching based motion compensation is performed for the current block using the selected set of weights.

Abstract: A video coding device includes a memory configured to store video data, and processing circuitry in communication with the memory. The processing circuitry is configured to determine that a current block of the video data stored to the memory is to be coded according to a merge mode, and to determine a temporal candidate associated with a merge candidate list for the current block in accordance with the merge mode. The processing circuitry is further configured to determine a pool of spatial candidates associated with the merge candidate list, based on each spatial candidate of the pool having a same reference picture as the temporal candidate, and to set a local illumination compensation (LIC) flag value for the temporal candidate based on respective LIC flag values of one or more spatial candidates of the pool.

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.

Abstract: Techniques for processing video data are described. The techniques include determining a first partition and a second partition for a current block coded in geometric partition mode, determining a first and second prediction block based on a first and second motion vector, blending the first prediction block and the second prediction block based on weights indicative of an amount to scale samples in the first prediction block and the second prediction block to generate a final prediction block, dividing the current block into a plurality of sub-blocks, determining a set of sub-blocks that each include at least one sample that corresponds to a prediction sample in the final prediction block that was generated based on equal weighting of a sample in the first prediction block and a sample in the second prediction block, and storing respective bi-prediction motion vectors for each sub-block in the determined set of sub-blocks.

Abstract: Techniques are described for decoding video data. A video decoder may determine chroma blocks in a chroma quantization group (QG) of the video data, determine a quantization parameter predictor that is the same for each of the chroma blocks of the chroma QG, determine an offset value that is the same for two or more of the chroma blocks of the chroma QG, determine a quantization parameter value for each of the two or more of the chroma blocks in the chroma QG based on the quantization parameter predictor and the offset value inverse quantize coefficients of one or more residual blocks for the chroma blocks based on the determined quantization parameter value, generate the one or more residual blocks based on the inverse quantized coefficients, and reconstruct the chroma blocks based on the one or more residual blocks.

Abstract: For a bi-directional inter predicted block, a video decoder is configured, using a first MV, to locate a first predictive block in a first reference picture; using a second MV, locate a second predictive block in a second reference picture; for a first sub-block of the first predictive block, determine a first amount of bi-directional optical flow (BIO) motion; determine a first final predictive sub-block for the block of video data based on the first amount of BIO motion; for a second sub-block of the first predictive block, determine a second amount of BIO motion; determine a second final predictive sub-block for the block of video data based on the second amount of BIO motion; and based on the first final predictive sub-block and the second final predictive sub-block, determine a final predictive block for the block of video data.

Abstract: A video decoder can be configured to determine that a block of the video data is formatted in accordance with a 4:4:4 video coding format; determine that the block of the video data is encoded in an intra prediction mode; determine that a smallest chroma intra prediction unit (SCIPU) is disabled for the block in response to determining that the block has the 4:4:4 video coding format; decode the block of the video data based on the determination that the SCIPU is disabled; and output decoded video data comprising a decoded version of the 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 decoding video data includes receiving encoded data for a current block of the video data, the current block comprising one or more escape mode encoded samples and decoding, from the encoded data, a value indicating that the current block includes the one or more escape mode encoded samples. The method further includes, in response to determining that the value indicates that the current block includes the one or more escape mode encoded samples and that a current tree type for the current block is not dual tree chroma, decoding an absolute value for a luma delta quantization parameter for the current block and a sign for the luma delta quantization parameter. The method further includes reconstructing the current block based on the absolute value for the luma delta quantization parameter for the current block and the sign for the luma delta quantization parameter.

Abstract: A method of coding video data comprising determining a quantization group (QG) based on one or more of a size of a CU splitting node and a value of a region-based parameter, determining a single quantization parameter for all blocks of video data within the determined quantization group, and performing a quantization process on transform coefficients of all blocks of video data within the determined quantization group using the determined single quantization parameter.

Abstract: A device for decoding video data is configured to perform interpolation filtering using an N-tap filter to generate an interpolated search space for a first block of video data; obtain a first predictive block in the interpolated search space; determine that a second block of video data is encoded using a bi-directional inter prediction mode and a bi-directional optical flow (BIO) process; perform an inter prediction process for the second block of video data using the bi-directional inter prediction mode to determine a second predictive block; perform the BIO process on the second predictive block to determine a BIO-refined version of the second predictive block, wherein a number of reference samples used for calculating intermediate values for BIO offsets is limited to a region of (W+N?1)×(H+N?1) integer samples, wherein W and H correspond to a width and height of the second block in integer samples.

Abstract: An example method includes coding a value of a motion vector difference (MVD) for a current block of video data; obtaining, from a motion vector (MV) buffer, a value of a motion vector predictor (MVP) for the current block of video data; determining a resolution of the value of the MVD for the current block; obtaining a storage resolution shift amount for MVs; rounding, based on the storage resolution shift amount, the value of the MVD obtained from the MV buffer directly to the resolution of the value of the MVD; adding the rounded value of the MVP to the value of the MVD to obtain a value of a MV for the current block; obtaining, based on the MV for the current block, samples of a predictor block for the current block; and reconstructing samples of the current block based on the samples of the predictor block.

Abstract: A device and method for coding video data utilizes ultimate motion vector expression (UMVE). The device determines a candidate list from one or more spatial neighboring blocks in a set of spatial neighboring blocks that spatially neighbor a current block of video data. The device may determine a base candidate index, a direction index and a distance index based on data obtained in the bitstream and may use those indices to determine a base candidate, a direction and a distance. The device may also use the direction and distance to calculate a motion vector difference (MVD). The device may determine a prediction block using the MVD and a motion vector of the base candidate, and decode the current block based on the prediction block.

Abstract: Examples of block-level signaling of quantization parameter offsets is described. Such block-level signaling of quantization parameter offsets provides block level flexibility to determine a more precise chroma quantization parameter (QP) for a chroma block. With the block-level quantization parameter offset signaling described in this disclosure, there is more flexibility in defining the chroma QP, resulting in more accurate determination of chroma QP on a chroma block-by-chroma block basis.

Abstract: A video decoder can be configured to perform a filtering operation by determining a first difference value that corresponds to a difference between the sample value of the selected sample and a sample value of a first neighboring sample; multiplying the first difference value by a first weighting parameter to determine a first weighted difference value; determining a second difference value that corresponds to a difference between the sample value of the selected sample and a sample value of a second neighboring sample; multiplying the second difference value by a second weighting parameter to determine a second weighted difference value; and adding the first weighted difference value and the second weighted difference value to the sample value of the selected sample to determine the modified sample value.