Abstract: Methods and devices are provided for decoding a video block in GPM. The method includes: partitioning the video block into first and second geometric partitions; receiving a first GPM with a motion vector refinement (GPM-MVR) enable flag for the first geometric partition and receiving a second GPM-MVR enable flag for the second geometric partition; receiving a joint template matching (TM) enable flag for the first and second geometric partition that jointly indicates whether a uni-directional motion of the first partition is refined by TM and whether a uni-directional motion of the second partition is refined by the TM; receiving a first merge GPM index for the first geometric partition and a second merge GPM index for the second geometric partition; constructing a uni-directional MV candidate list of the GPM; and generating a uni-directional MV for the first geometric partition and a uni-directional MV for the second geometric partition.

Abstract: Implementations of the disclosure provide video processing systems and methods. The video processing method may include receiving, by one or more processors, a video frame of a video for in-loop filtering. For a target pixel of the video frame, the video processing method may further include selecting, by the one or more processors, a bilateral filtering window to perform the in-loop filtering on the target pixel from a group of candidate filtering windows. The group of candidate filtering windows include a plurality of side filtering windows and a full filtering window. The video processing method may also include filtering, by the one or more processors, the target pixel of the video frame using the selected bilateral filtering window.

Abstract: The present disclosure relate to a bit-width control method of bi-directional optical flow (BDOF) for coding a video signal. The method includes obtaining a first reference picture I(0) and a second reference picture I(1) associated with a video block, obtaining first prediction samples I(0)(i,j) of the video block from a reference block in the first reference picture I(0), obtaining second prediction samples I(1)(i,j) of the video block from a reference block in the second reference picture I(1), controlling internal bit-widths of the BDOF by deriving internal bit-widths of intermediate parameters, obtaining motion refinements for samples in the video block based on the BDOF being applied to the video block based on the first prediction samples I(0)(i,j) and the second prediction samples I(1)(i,j), and obtaining bi-prediction samples of the video block based a the motion refinements.

Abstract: Methods and devices are provided for reducing the decoding latency introduced by LMCS. In one method, one or more luma prediction sample values are selected from an output of a bilinear filter of Decoder-side Motion Vector Derivation (DMVR), the one or more selected luma prediction sample values are adjusted into luma prediction sample values with the same bit depth as an original coding bit depth of an input video, the luma prediction sample values with the same bit depth as the original coding bit depth of the input video are used to derive a scaling factor for decoding one or more chroma residual samples, the scaling factor is used to scale one or more chroma residual samples, and one or more chroma residual samples are reconstructed by adding the one or more scaled chroma residual samples and their corresponding chroma prediction samples.

Abstract: Provided is a method for video decoding including: receiving a control variable enabling adaptive switch between motion vector refinement (MVR) offset sets; receiving an indication variable enabling adaptive switch between codeword tables that binarize offset magnitudes in the MVR offset sets under the coding level; partitioning the video block into a first and a second geometric partition; selecting an MVR offset set based on the control variable; receiving syntax elements to determine a first and second MVR offsets applied to the first and second geometric partitions from the selected MVR offset set; obtaining a first and second MVs from a candidate list for the first and the second geometric partition; calculating a first and second refined MVs based on the first and second MVs and the first and second MVR offsets; and obtaining prediction samples based on the first and second refined MVs.

Abstract: A method for video decoding is provided. The method includes: deriving, by a decoder, an initial motion vector (MV) of a current block; determining, by the decoder, a cost value for the initial MV; obtaining, by the decoder, an updated cost value by decreasing the cost value for the initial MV; and deriving, by the decoder, a refined MV based on the updated cost value.

Abstract: A method for video encoding is provided. The method includes: partitioning, by an encoder, a video frame into multiple blocks; deriving, by the encoder, an initial motion vector (MV) of a current block in the multiple blocks; determining, by the encoder, cost values for the initial MV and each of a plurality of MV candidates; obtaining, by the encoder, updated cost values by decreasing a cost value for the initial MV or increasing cost values for the MV candidates; and deriving, by the encoder a refined MV based on the updated cost values.

Abstract: A computer system acquires a video bitstream. The video bitstream includes data associated with multiple encoded pictures. Each encoded picture includes one or more coding units (CUs). While decoding a current CU of a picture in the video bitstream, the current CU having a plurality of reference subblocks located in one or more reference pictures, in accordance with a determination that the plurality of reference subblocks satisfy a first set of predefined conditions for enabling a subblock-based temporal motion vector prediction (SbTMVP) mode, the computer system retrieves, from the video bitstream, syntax elements associated with the SbTMVP mode. The computer system then decodes the current CU using the retrieved syntax elements associated with the SbTMVP mode.

Abstract: Embodiments of video coding systems and methods are described for reducing coding latency introduced by decoder-side motion vector refinement (DMVR). In one example, two non-refined motion vectors are identified for coding of a first block of samples (e.g. a first coding unit) using bi-prediction. One or both of the non-refined motion vectors are used to predict motion information for a second block of samples (e.g. a second coding unit). The two non-refined motion vectors are refined using DMVR, and the refined motion vectors are used to generate a prediction signal of the first block of samples. Such embodiments allow the second block of samples to be coded substantially in parallel with the first block without waiting for completion of DMVR on the first block. In additional embodiments, optical-flow-based techniques are described for motion vector refinement.

Abstract: A method, a computing device, and a computer readable storage medium are provided for video coding. The method may include deriving parameter ? and parameter ? for a CCLM mode by using a predetermined number of neighboring reconstructed luma samples and chroma samples in a CU; and generating a final chroma predictor for the chroma samples of the CU by using the parameter ? and the parameter ?.

Abstract: A method and a computing device are provided for video coding. The method may include deriving parameter ? and parameter ? for a CCLM mode by using a predetermined number of neighboring reconstructed luma samples and chroma samples in a CU; and generating a final chroma predictor for the chroma samples of the CU by using the parameter ? and the parameter ?.

Abstract: Methods and devices are provided for reducing the decoding latency introduced by LMCS. In one method, one or more luma prediction sample values are selected from an output of a bilinear filter of Decoder-side Motion Vector Derivation (DMVR), the one or more selected luma prediction sample values are adjusted into luma prediction sample values with the same bit depth as an original coding bit depth of an input video, the luma prediction sample values with the same bit depth as the original coding bit depth of the input video are used to derive a scaling factor for decoding one or more chroma residual samples, the scaling factor is used to scale one or more chroma residual samples, and one or more chroma residual samples are reconstructed by adding the one or more scaled chroma residual samples and their corresponding chroma prediction samples.

Abstract: An electronic apparatus performs a method of decoding video data. The method includes: receiving, from the video data, an Adaptation Parameter Set (APS) identifier associated with a number of previously used Cross-Component Sample Adaptive Offset (CCSAO) filter offset sets stored in APS; receiving, from the video data, a syntax in Picture Header (PH) or Slice Header (SH) that indicates the APS identifier used for a current picture or slice; decoding, for the current coding tree unit (CTU), a filter set index that indicates a particular previously used CCSAO filter offset set of the number of offset sets in the APS associated with the APS identifier; and applying the particular previously used CCSAO filter offset set to the current CTU of the video data.

Abstract: A bit-width representation method of prediction refinement with optical flow (PROF), apparatus, and a non-transitory computer-readable storage medium are provided. The method includes obtaining a reference picture I associated with a video block within the video signal, obtaining prediction samples I(i,j) of the video block from a reference block in the reference picture I, controlling internal bit-widths of a PROF derivation process for various representation precisions of internal PROF parameters by applying right-shifting to the internal PROF parameters based on different bit-shift values, obtaining prediction refinement values for samples in the video block based on the PROF derivation process being applied to the video block based on the prediction samples I(i,j), and obtaining prediction samples of the video block based on the combination of the prediction samples and the prediction refinement values.

Abstract: Systems and methods are described for reducing the complexity of using bi-directional optical flow (BIO) in video coding. In some embodiments, bit-width reduction steps are introduced in the BIO motion refinement process to reduce the maximum bit-width used for BIO calculations. In some embodiments, simplified interpolation filters are used to generate predicted samples in an extended region around a current coding unit. In some embodiments, different interpolation filters are used for vertical versus horizontal interpolation. In some embodiments, BIO is disabled for coding units with small heights and/or for coding units that are predicted using a sub-block level inter prediction technique, such as advanced temporal motion vector prediction (ATMVP) or affine prediction.

Abstract: Implementations of the disclosure provide systems and methods for motion refinement in a video. The method may include determining an initial motion vector for a video block of a video frame from the video. The method may include determining a matching target based on a weighted combination of a first reference block from a first reference frame in the video and a second reference block from a second reference frame in the video. The method may include performing a bilateral matching based motion refinement process at a block level to iteratively update the initial motion vector based on the matching target until a refined motion vector is obtained. The method may include refining a motion vector for each sub-block in the video block using the refined motion vector of the video block. Refining the motion vector at a sub-block level applies an affine motion model of the video block.

Abstract: A method for decoding a video block in GPM includes: partitioning the video block into two geometric partitions; constructing a uni-directional motion victor (MV) candidate list by adding regular merge candidates; in response to determining that the candidate list is not full, constructing a first updated candidate list by adding additional uni-directional MVs derived from bi-prediction MVs of a regular merge candidate list to the candidate list; in response to determining that the first updated candidate list is not full, constructing a second updated candidate list by adding pairwise average candidates to the first updated candidate list; in response to determining that the second updated candidate list is not full, periodically adding zero uni-directional MVs to the second updated candidate list until a maximum length is reached; and respectively generating a uni-directional MV for each geometric partition.

Abstract: Systems, methods, and instrumentalities are described herein for calculating local illumination compensation (LIC) parameters for bi-predicted coding unit (CU). The LIC parameters may be used to generate adjusted samples for the current CU and to address local illumination changes that may exist among temporal neighboring pictures. LIC parameters may be calculated based on bi-predicted reference template samples and template samples for a current CU. Bi-predicted reference template samples may be generated based on reference template samples neighboring temporal reference CUs. For example, the bi-predicted reference template samples may be generated based on averaging the reference template samples. The reference template samples may correspond to template samples for the current CU. A CU may be or may include a coding block and/or a sub-block that may be derived by dividing the coding block.

Abstract: A method for video coding is provided. The method includes: deriving an initial motion vector (MV) of a current block; deriving a plurality of MV candidates for decoder-side motion vector refinement (DMVR); determining cost values for the initial MV and each of the MV candidates; obtaining updated cost values of both the initial MV and the MV candidates by adjusting at least one of the cost values to favor the initial MV; and deriving a refined MV based on the updated cost values of both the initial MV and the MV candidate.

Abstract: The present disclosure relates to an intra sub-partition (ISP) method of decoding a video signal.