Tencent America LLC

Lien-Fei Chen

Shan Liu

Guichun Li

Xin Zhao

Xiang Li

Xiang Yang Li

Ling Li

Xiaozhong Xu

Han Gao

Roman Chernyak

Madhu Peringassery Krishnan

Biao Wang

A method includes receiving a bitstream of coded information for a sequence of pictures, the coded information indicates an inter prediction of a current block in a current picture using a formular based inter prediction technique, the formular based inter prediction technique generates a prediction sample of the current block based on a formular with reconstructed samples of a reference block in a reference picture being input to the formular, the formular includes parameters derived based on a current template of the current block and a reference template of the reference block. The method also includes constructing a candidate list including one or more coded blocks associated with the current block, a coded block in the one or more coded blocks is a candidate that provides formular based inter prediction information.

On list construction of coded information of inter prediction

Processing circuitry receives coded information of a motion vector difference (MVD). The processing circuitry calculates cost values associated with value combinations for a plurality of bits in coding bits of the MVD, at least one of the plurality of bits is a bit in a codeword for indicating a magnitude for the MVD. The processing circuitry determines a combination of prediction values for the plurality of bits from the value combinations, the combination of prediction values is associated with a lowest cost value in the cost values. The processing circuitry decodes the coded information of the MVD to obtain one or more indicators for the combination of prediction values, the one or more indicators indicates whether the plurality of bits is correctly predicted by the combination of prediction values. The processing circuitry determines the MVD based on the combination of prediction values and the one or more indicators.

Method and apparatus for motion vector coding

Processing circuitry receives a video bitstream comprising a current coding block in a picture coded in a template-based multiple reference line intra prediction (TMRL) mode. The processing circuitry determines combinations of reference lines and intra prediction modes for the current coding block. A first combination in the combinations includes a first reference line and a first intra prediction mode. For the first combination, the processing circuitry calculates template entry delta values respectively associated with entries of a template of the current coding block based on the first reference line and the first intra prediction mode, and calculates a first template matching cost value by unequal weighting of the template entry delta values. The processing circuitry sorts the combinations according to template matching cost values respectively associated with the combinations, selects a specific combination from the sorted combinations, and reconstructs the current coding block according to the specific combination.

Template matching for multiple reference line intra prediction

In a method of video decoding at a video decoder, a bitstream of a coded video associated with a current coding block that is partitioned into a first part and a second part along a partition edge for prediction in a geometric partitioning mode is received. A weight index at a sample position of the current coding block is determined based on a look up table. The weight index is used to derive a blending weight for blending two prediction signals corresponding to the first part and the second part of the current coding block. A stored motion vector type for a first motion storage unit in a motion field of the current coding block is determined based on a motion index of the first motion storage unit. A motion vector of the first motion storage unit is stored based on the stored motion vector type.

Weight derivation for geometric partitioning mode

Aspects of the disclosure provide methods and apparatuses for video encoding/decoding. In some examples, an apparatus for video decoding includes processing circuitry. The processing circuitry receives a coded video bitstream including a current picture. The current picture includes a current block. The processing circuitry determines, based on decoded information from the coded video bitstream, that the current block in the current picture is coded in an affine bi-prediction mode. The current block is predicted by a plurality of control point motion vectors. The processing circuitry refines the plurality of control point motion vectors by applying bilateral matching motion refinement, and reconstructs the current block according to the refined plurality of control point motion vectors associated with the current block.

Method for affine motion refinement

In a method for video decoding in a video decoder, prediction information of a current block in a coded bitstream is decoded. The prediction information indicates that template matching (TM) is applied with a merge mode with motion vector difference (MMVD) mode and indicates motion vector difference (MVD) information of the current block. Using the MMVD mode, one or more MVD candidates is determined based on the MVD information. TM is performed to search for a matched MVD between a current template of the current block and a reference template of a reference block of the current block based on the one or more MVD candidates determined using the MMVD mode. The current block is reconstructed based on a motion vector (MV) that is a summation of a motion vector predictor (MVP) and the matched MVD.

Template matching with merge mode with motion vector difference

A video bitstream is received. The video bitstream includes a current block comprising a plurality of subblocks and a template region of the current block comprising a plurality of template subblocks adjacent to at least one of a top side and a left side of the current block. A motion vector (MV) located in a center position of the current block is determined. The MV is determined based on at least one MV of the plurality of subblocks of the current block. A MV for each of the plurality of template subblocks is determined based on the MV located in the center position of the current block and a respective MV of a corresponding subblock of the plurality of subblocks that is adjacent to the respective template subblock. The current block is reconstructed based on the determined MVs for the plurality of template subblocks.

Motion vector derivation of subblock-based template-matching for subblock based motion vector predictor

Aspects of the disclosure provide methods and apparatuses for video encoding/decoding. In some examples, an apparatus for video decoding includes receiving circuitry and processing circuitry. The processing circuitry extracts, from a bitstream, a signal indicative of an application of a template matching based block vector refinement for coding a current block in a current picture referencing (CPR) mode. The processing circuitry derives a first refined block vector associated with the current block according to the template matching based block vector refinement. The first refined block vector includes a first block vector refinement offset applied on a first block vector associated with the current block. The processing circuitry reconstructs the current block according to a first reference block in a same picture as the current block, the first reference block being indicated by the first refined block vector.

Block vector refinement method for intra block copy

Aspects of the disclosure include methods and an apparatus for video coding. The apparatus includes processing circuitry that receives coded information of a current block in a current picture. The current block is coded with a first intra prediction mode that is different from a plurality of intra prediction modes including a DC mode, a Planar mode, and angular intra prediction modes. A candidate block in the current picture coded by an intra prediction mode different from the plurality of intra prediction modes is selected. If the candidate block is located within a pre-defined region, a second intra prediction mode is derived from the plurality of intra prediction modes for the candidate block. The second intra prediction mode is associated with the current block and is used to select a transform for the current block and/or to construct a most probable mode (MPM) list for another block.

Intra prediction mode derivation for coding blocks

Processing circuitry receives a coded video bitstream comprising coded information of a current block in a current picture, the coded information is indicative of an AMVP-merge mode, the AMVP-merge mode uses a bi-directional predictor including an AMVP predictor in a first direction and a merge predictor in a second direction. The processing circuitry constructs an AMVP candidate list that includes a plurality of AMVP candidates for the AMVP predictor and constructs a merge candidate list that includes a plurality of merge candidates for the merge predictor. The merge candidate list includes an SbTMVP candidate. The processing circuitry determines the AMVP predictor from the AMVP candidate list, determines the merge predictor from the merge candidate list, and reconstructs the current block according to a combination of a first prediction according to the AMVP predictor in the first direction and a second prediction according to the merge predictor in the second direction.

AMVP-merge mode with SBTMVP

Processing circuitry for video decoding receives coded information of a current block in a current picture from a coded video bitstream, the coded information is indicative of applying local illumination compensation (LIC) on the current block in the current picture. The processing circuitry derives, parameters of an LIC model, according to a first template of a current block and a second template of a reference block in a reference picture. The reference block is pointed based on a motion vector for the current block. The first template includes a subset of reconstructed neighboring samples that are above and left to the current block, and the second template includes collocated samples to the subset of the reconstructed neighboring samples. The processing circuitry applies the LIC model on the current block according to the reference block to generate compensated samples of the current block.

Local illumination compensation

Processing circuitry receives coded information of a current block indicative of applying LIC on the current block according to at least a first reference block in a first reference picture. The processing circuitry determines, for a sample in the current block, at least a first reference sample in the first reference block, the first reference sample is co-located to the sample in the current block. The processing circuitry calculates a weighted sum of a plurality of terms and an offset for the LIC according to a plurality of parameter values for a plurality of parameters used in the LIC, and reconstructs the sample accordingly. The plurality of parameter values includes at least a first weighting value for a first weighting that is applied to a non-linear term of the first reference sample of a kth power, k is a power index value and is not equal to 1.

Local illumination compensation for bi-prediction

A method and an apparatus are provided. The apparatus includes processing circuitry that receives a coded video bitstream comprising a current picture that includes a current block. The processing circuitry determines, based on a syntax element in the coded video bitstream, that the current block including a plurality of subblocks is coded in a subblock-based temporal motion vector prediction (SbTMVP) mode. The processing circuitry determines a plurality of displacement vector (DV) predictor (DVP) candidates and receives a base index indicating a DVP in the plurality of DVP candidates and a DV offset of the current block. The processing circuitry determines a DV based on the DVP and the DV offset. The DV indicates a block collocated with the current block in a collocated reference picture. The processing circuitry reconstructs a subblock in the plurality of subblocks based on motion information of a corresponding subblock in the collocated block.

Subblock level temporal motion vector prediction with multiple displacement vector predictors and an offset

Aspects of the disclosure provide a method and an apparatus including processing circuitry that adds merge candidates into a merge candidate list of a current block in a current picture. The merge candidates include available merge candidates including one or more of spatial motion vector predictors (MVP(s)), temporal MVP(s), non-adjacent MVP(s), history-based MVP(s), and pairwise average MVP(s). Whether the merge candidate list includes all available SMVP, TMVP, NA-MVP, HMVP, and PAMVP, and no merge candidate in the merge candidate list has a zero motion vector (zero MV) are determined. If the merge candidate list includes all available SMVP, TMVP, NA-MVP, HMVP, and PAMVP, and no merge candidate in the merge candidate list has the zero MV, the merge candidate having the zero MV is added to the merge candidate list. Merge candidates in the merge candidate list including the merge candidate having the zero MV are reordered using template matching.

Zero motion vector in adaptive reordering of merge candidates (ARMC)

A current block is partitioned into a first partition and a second partition. Template samples of the current block are split into a first template region adjacent to the first partition and a second template region adjacent to the second partition. A plurality of first candidate reference blocks is determined for the first partition. A plurality of second candidate reference blocks is determined for the second partition. At least one of the plurality of first candidate reference blocks and the plurality of second candidate reference blocks is reordered based on a size of the first template region of the template samples and a size of the second template region of the template samples. The current block is reconstructed based on a received index value and based on the reordered at least one of the plurality of first candidate reference blocks and the plurality of second candidate reference blocks.

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Taipei, Taiwan

Lien-Fei Chen