Abstract: A video coding device generates first and second components of a current picture. Additionally, the video coding device determines a first parameter and a second parameter. The first and second parameters are each based on a value of a current sample in the first component. The video coding device applies a cross-component filter to the current sample, thereby determining a filtered value of the current sample based on the first parameter, the second parameter, and one or more cross-component samples. Each of the one or more cross-component samples is in the second component.

Abstract: In one example, an apparatus for encoding video data includes a video encoder configured to select an intra-prediction mode to use to encode a block of video data, determine whether the block includes a sub-block of a size for which multiple transforms are possible based on the size of the sub-block and the selected intra-prediction mode, when the block includes the sub-block of the size for which multiple transforms are possible based on the size of the sub-block and the selected intra-prediction mode, select one of the multiple possible transforms, transform the sub-block using the selected one of the multiple possible transforms, and provide an indication of the selected one of the multiple possible transforms for the size of the block.

Abstract: A video encoder performs an Advanced Motion Vector Prediction (AMVP) process for a current block of a current picture. As part of performing the AMVP process, the video encoder may determine whether local illumination compensation (LIC) is being applied in the AMVP process. Based on LIC being applied in the AMVP process, the video encoder may skip a bi-directional AMVP motion estimation process that sets a cost associated with encoding the current block using a bi-directional AMVP mode. Rather, the video encoder may set the cost to a maximum cost value.

Abstract: Improved systems and methods related to decoder-side motion vector derivation (DMVD), for example, in applying one or more constraints to motion information, such as a MV derived by DMVD, and/or a MV difference between an initial MV and an MV derived by DMVD. These techniques may be applied to any of the existing video codecs, such as HEVC (High Efficiency Video Coding), and/or may be an efficient coding tool in any future video coding standards. In one example, the block size used for DMVD can be restricted. In another example, FRUC bilateral matching can be simplified by not searching outside reference blocks indicated by the original motion vector.

Abstract: A method and system of coding video data using affine motion compensation is described. A method may include receiving a current block of video data that is to be decoded using affine motion compensation, and constructing an affine motion vector predictor (MVP) list for one or more control points of the current block of video data, including adding a motion vector from a neighboring block of video data to the affine MVP list in the case that the motion vector has an associated reference picture that is the same as a target reference picture for the current block of video data. A video coder may determine motion vectors for the one or more control points using the affine MVP list, and code the current block of video data with the determined motion vectors for the one or more control points of the current block of video data.

Abstract: A device for video decoding may include a memory configured to store video data and a processor configured receive a bitstream including encoded video data. The processor may be configured to select a number of template matching (TM) candidates for a temporal layer or slice during the video decoding. The number of TM candidates selected are fixed prior to the video decoding, or adaptively calculated during the video decoding. The processor may be configured to generate a prediction block and residual block, based on a template matching candidate, to reconstruct the video data.

Abstract: Motion compensated prediction using affine motion models can be used to improve coding efficiency. In a practical encoder/decoder, a line buffer is used to store associated data for neighboring blocks. Embodiments of affine model based motion compensated prediction include methods and systems of determining motion vectors for control points that are aware of line buffer storage limitations.

Abstract: A method of decoding video data includes constructing, by a video decoder implemented in processing circuitry, a candidate list of motion vector information for a portion of a current frame. The method includes receiving, by the video decoder, signaling information indicating starting motion vector information of the candidate list of motion vector information, the starting motion vector information indicating an initial position in a reference frame. The method includes refining, by the video decoder, based on one or more of bilateral matching or template matching, the starting motion vector information to determine refined motion vector information indicating a refined position in the reference frame that is within a search range from the initial position. The method includes generating, by the video decoder, a predictive block based on the refined motion vector information and decoding, by the video decoder, the current frame based on the predictive block.

Abstract: A method of decoding video data includes determining, by a video decoder, a neighboring block in a current frame is inter coded. The method includes, in response to determining the neighboring block is inter coded, determining, by the video decoder, a template for a current block in the current frame based on a partial reconstruction of the neighboring block. The method includes determining, by the video decoder, a reference block in a reference frame corresponding to the template for the current block and determining, by the video decoder, motion vector information for the current frame based on the reference block and the template. The method includes generating, by the video decoder, a predictive block for the current block of video data based on the motion vector information and decoding, by the video decoder, the current block of video data based on the predictive block.

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: 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 method of decoding video data includes determining, by a video decoder implemented in circuitry, a bi-predicted MV predictor for a block of video data. The bi-predicted MV predictor indicates a first input reference block and a second input reference block. The method further includes refining, by the video decoder, the bi-predicted MV predictor using gradient information to determine a refined bi-predicted MV predictor indicating a first refined reference block that is within a search range from the first input reference block and a second refined reference block that is within the search range from the second input reference block. The method further includes generating, by the video decoder, a predictive block for the block of video data based on the refined bi-predicted MV predictor, and decoding, by the video decoder, the block of video data based on the predictive block.

Abstract: A device for decoding video data determines a block of video data is coded in an inter prediction mode; implicitly determines that a decoder-side motion vector derivation (DMVD) mode is enabled for the block of video data; determines motion information for the block of video data; uses the motion information to determine a reference block in accordance with the DMVD mode; and generates a predictive block for the block of video data based on the reference block.

Abstract: Techniques related to decoder-side motion vector derivation (DMVD) are described. For example, this disclosure describes techniques related to applying one or more constraints to motion information, such as a motion vector (MV) derived by DMVD, and/or a MV difference between an initial MV and an MV derived by DMVD. When the constraint is applied to the DMVD, in certain examples, only the derived motion information which meets the constraint is regarded as valid motion information. Conditions may be placed on the constraints.

Abstract: Techniques and systems are provided for deriving one or more sets of affine motion parameters at a decoder. For example, the decoder can obtain video data from an encoded video bitstream. The video data includes at least a current picture and a reference picture. The decoder can determine a set of affine motion parameters for a current block of the current picture. The set of affine motion parameters can be used for performing motion compensation prediction for the current block. The set of affine motion parameters can be determined using a current affine template of the current block and a reference affine template of the reference picture.

Abstract: A video decoder can be configured to determine that a block of video data is encoded using a bi-directional inter prediction mode; determine that the block of video data is encoded using a bi-directional optical flow (BIO) process; inter predict the block of video data according to the bi-directional inter prediction mode; perform the BIO process for the block, wherein performing the BIO process for the block comprises determining a single motion vector refinement for a group of pixels in the block, wherein the group of pixels comprises at least two pixels; refine the group of pixels based on the single motion vector refinement; and output a BIO refined predictive block of video data comprising the refined group of pixels.

Abstract: An example device for decoding video data includes a memory configured to store video data, and a video decoder implemented in circuitry and configured to determine that motion information of a current block of the video data is to be derived using decoder-side motion vector derivation (DMVD), determine a pixels clue for the current block, the pixels clue comprising pixel data obtained from one or more groups of previously decoded pixels, derive the motion information for the current block according to DMVD from the pixels clue, and decode the current block using the motion information. The video decoder may generate the pixels clue using multiple hypothesis predictions from multiple motion compensated blocks. The video decoder may determine an inter-prediction direction for the motion information according to matching costs between different prediction directions. The video decoder may refine the motion information using a calculated matching cost for the pixels clue.

Abstract: A method of decoding video comprising: receiving an encoded block of video data, determining a transform for the encoded block of video data, wherein the transform has a size S that is not a power of two, rounding S to a power of two creating a transform with a modified size S?, applying an inverse transform with the modified size S? to the encoded block of video data to create residual video data, and decoding the residual video data to create decoded block of video data.

Abstract: A video decoder determines a current block of a current picture of video data has a size of P×Q, wherein P is a first value corresponding to a width of the current block and Q is a second value corresponding to a height of the current block, wherein P is not equal to Q, wherein the current block includes a short side and a long side, and wherein the first value added to the second value does not equal a value that is a power of 2; decodes the current block of video data using intra DC mode prediction, wherein decoding the current block of video data using intra DC mode prediction comprises performing a shift operation to calculate a DC value and generating a prediction block for the current block of video data using the calculated DC value; and outputs a decoded version of the current picture.

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.