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

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: Methods, apparatuses, and non-transitory computer-readable storage mediums are provided for decoding a video signal. The method includes obtaining a first reference picture I associated with a video block, obtaining control point motion vectors (CPMVs) of an affine coding block based on the video block, obtaining prediction samples I(i, j) of the affine coding block, deriving PROF prediction sample refinements of the affine coding block based on the PROF, receiving an LIC flag that indicates whether the LIC is applied to the affine coding block, deriving, and when the LIC is applied, LIC weight and offset based on neighboring reconstructed samples of the affine coding block and their corresponding reference samples in the first reference picture, and obtaining final prediction samples of the affine coding block based on the PROF prediction sample refinements and the LIC weight and offset.

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

Abstract: Methods, apparatuses, and non-transitory computer-readable storage mediums are provided for video decoding. In one method, a decoder receives a Sequence Parameter Set (SPS) rice extension flag that indicates whether an extension of rice parameter derivation for binarization of abs_remainder and dec_abs_level is enabled. In a second method, the decoder may receive a Sequence Parameter Set (SPS) rice adaption enabled flag that indicates whether rice parameter derivation for binarization of abs_remainder and dec_abs_level is used.

Abstract: An electronic apparatus performs a method of updating an inter-predicted current block using a neighboring affine block. The electronic apparatus first identifies a pixel within the inter-predicted current block, the pixel having a first inter-predicted pixel value. Next, the electronic apparatus determines a motion vector difference for the pixel based on a set of affine parameters of the neighboring affine block and then a pixel value difference for the pixel according to the motion vector difference. The pixel value difference is an inner product of the pixel value gradient vector and the motion vector difference as the pixel value difference. Finally, the electronic apparatus updates the first inter-predicted pixel value with the pixel value difference as a second inter-predicted pixel value.

Abstract: Methods and devices are provided for decoding a video block in GPM. The method includes: partitioning the video block into a first geometric partition and a second geometric partition; receiving a first template matching (TM) enable flag for the first geometric partition a second TM enable flag for the second geometric partition, the first TM enable flag indicating whether a uni-directional motion of the first geometric partition is refined by TM, and the second TM enable flag indicating 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 motion victor (MV) candidate list of the GPM; and generating a first uni-directional MV for the first geometric partition and a second uni-directional MV for the second geometric partition.