Tencent America LLC

Meng Xu

Shan Liu

Xiang Yang Li

Xiaozhong Xu

Xin Zhao

Guichun Li

Xiang Li

Stephan Wenger

Jing Ye

Fai Yeung

Weiwei Feng

Shalin Mahendra

Aspects of the disclosure provide methods and apparatuses for video encoding/decoding. An apparatus for video decoding includes processing circuitry that decodes prediction information for a current block in a current coded picture. The prediction information indicates a motion vector predictor index (MVP_idx) for selecting a motion vector predictor in a motion vector predictor list. The processing circuitry determines whether the MVP_idx is smaller than a threshold. When the MVP_idx is determined to be smaller than the threshold, the processing circuitry decodes a motion vector difference (MVD) corresponding to the motion vector predictor and reconstructs the current block based on the motion vector predictor and the MVD. When the MVP_idx is determined to be equal to or larger than the threshold, the processing circuitry reconstructs the current block based on the motion vector predictor without the MVD which is not signaled in the coded video sequence.

Methods and apparatuses for video coding

An apparatus for video decoding includes processing circuitry configured to receive a splitting direction syntax element, a first merge triangle index syntax element, and a second merge triangle index syntax element that are associated with a coding block of a picture. The coding block is coded according to a triangular prediction mode and partitioned into a first prediction unit and a second prediction unit according to a split direction. A first merge index identifies first motion information in a merge candidate list of the coding block. A second merge index identifies second motion information in the merge candidate list of the coding block. The coding block is reconstructed according to first prediction samples of the first prediction unit and second prediction samples of the second prediction unit. A value of the second merge triangle index syntax element is based on the first merge index.

Derivation of triangular prediction information

Methods and apparatuses for video coding. An example method includes: encoding information associated with a block of a picture to be included in a coded video bitstream. The encoding information indicating a position of a sub-region in the block and a position of an additional sub-region in each of at least one neighboring block of the block, a combined sub-region including the sub-region and the additional sub-region in each of the at least one neighboring block being at a center of a combined block including the block and the at least one neighboring block, wherein an outside area within the combined block completely surrounds and is outside of the combined sub-region, the combined sub-region and the outside area being determined based on the combined sub-region having residue data of samples above a predetermined threshold and the outside area having residue data of samples below or equal to the predetermined threshold.

Method and apparatus for video coding

Signaling for triangle mode

A method of video encoding includes determining a first maximum allowed number of triangular prediction mode (TPM) candidates of a TPM applied to a first set of coding blocks, and constructing a TPM candidate list of a current coding block within the first set of coding blocks processed with the TPM according to the determined first maximum allowed number of TPM candidates. The method also includes generating a coded bitstream including the current coding block encoded according to the constructed TPM candidate list and including a first syntax element indicating the first maximum allowed number of TPM candidates.

Signaling of flexible maximum allowed number of TPM candidates

A first motion vector and a second motion vector are determined for a first block in a current picture of a video, where the first motion vector is indicative of a first reference block in a first picture, and the second motion vector is indicative of a second reference block in a second picture. A bilateral template is generated based on a weighted combination of the first reference block and the second reference block. A refined first motion vector is determined based on the bilateral template and a first set of reference blocks in the first picture. A refined second motion vector is determined based on the bilateral template and a second set of reference blocks in the second picture. Prediction information of the first block is generated according to (i) the refined first motion vector, (ii) the refined second motion vector, and (iii) a final motion compensation interpolation filter.

Decoder side MV derivation and refinement

Methods and apparatuses for video encoding/decoding are provided. In some examples, an apparatus for video decoding includes receiving circuitry and processing circuitry. The processing circuitry decodes prediction information of a current block in a current picture from a coded video bitstream. The prediction information is indicative of an inter prediction mode. Then, the processing circuitry determines a usage of a first DMVD process on the current block at least partially based on a second DMVD process not being used on the current block. Further, the processing circuitry reconstructs the current block according to the inter prediction mode with the first DMVD process.

Aspects of the disclosure provide methods and apparatuses for video coding. In some examples, an apparatus includes processing circuitry that obtains motion information of a group of blocks in a picture from a coded video bitstream, the motion information indicating base motion vectors for the group of blocks, and the base motion vectors pointing to a reference picture in a prediction list. The processing circuitry determines a range of target motion vectors for the group of blocks along a particular coordinate direction according to the base motion vectors and a target difference, where, for any two motion vector within the range, a difference of integer-pixel parts thereof along the particular coordinate direction is equal to or less than the target difference. The processing circuitry further converts the base motion vectors into the target motion vectors according to the range for reconstructing samples of the group of blocks.

Constraining motion vectors of groups of blocks

In a method of video decoding in a decoder, a merge candidate list of a current coding block is constructed for processing the current coding block with a triangular prediction mode (TPM). The merge candidate list can include merge candidates each having one or two motion vectors. Each motion vector can be associated with a first reference picture list or a second reference picture list. A first motion vector and a second motion vector are determined from the motion vectors of the merge candidates on the merge candidate list. The current block is processed with the TPM with the first and second motion vectors as two motion vector predictors (MVPs) of two triangular partitions of the current coding block.

Aspects of the disclosure provide a method and an apparatus for video coding. In some embodiments, the apparatus includes processing circuitry. The processing circuitry can decode encoding information for a block of a picture in a coded video bitstream. The encoding information indicates a position of a sub-region in the block and a position of an additional sub-region in each of at least one neighboring block of the block. A combined sub-region includes the sub-region and the additional sub-region in each of the at least one neighboring block. The combined sub-region is at a center of a combined block including the block and the at least one neighboring block. The processing circuitry can reconstruct first samples that are inside the combined sub-region using residue data of the first samples and reconstruct second samples that are outside of the combined sub-region in the combined block without residue data.

A method of video decoding performed in a video decoder is provided. In the method, a bit stream including coded bits of bins of syntax elements is received. The syntax elements correspond to residues of a region of a transform skipped block in a coded picture. Context modeling is performed to determine a context model for each of a number of the bins of syntax elements of the region. The number of the bins of syntax elements that are context coded does not exceed a maximum number of context coded bins set for the region. The coded bits of the number of the bins of syntax elements are decoded based on the determined context models.

A method for video decoding includes decoding prediction information of a current block, the prediction information indicating a sub-block based inter prediction mode, the current block including a plurality of sub-blocks arranged into one or more areas. For each area, the method includes determining base motion vectors of a portion of the sub-blocks within the area, the portion including at least one non-corner sub-block of the current block, and converting the base motion vectors of the portion of the sub-blocks into respective target motion vectors. The method further includes generating reconstructed samples of the corresponding area according to the target motion vectors of the portion of the sub-blocks, and reconstructing the current block for output based on reconstructed samples of the one or more areas

Method and apparatus for video coding with motion vector constraints

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 decodes prediction information of a current block from a coded video bitstream. The prediction information is indicative of a subset of inter prediction modes associated with a merge flag being false. Then, the processing circuitry decodes at least an additional flag that is used for selecting a specific inter prediction mode from the subset of inter prediction modes. Further, the processing circuitry reconstructs samples of the current block according to the specific inter prediction mode.

Signaling for non-merge inter modes

In a method for video decoding in a decoder, a first motion vector and a second motion vector for a first block in a current picture are received. The first motion vector is indicative of a first reference block in a first picture, and the second motion vector is indicative of a second reference block in a second picture. A bilateral template is generated based on a weighted combination of the first reference block and the second reference block. A refined first motion vector and a refined second motion vector are determined based on the bilateral template, reference blocks in the first picture and reference blocks in the second picture respectively. An initial motion vector of a second block that is ceded after the first block is determined according to at least one of the first motion vector and the second motion vector for the first block.

Aspects of the disclosure provide methods and apparatuses for video encoding/decoding. In some examples, an apparatus for video decoding includes processing circuitry that decodes prediction information for a plurality of first blocks in a current coded picture that is a part of a coded video sequence. The prediction information indicates that the plurality of first blocks is coded in a local illumination compensation (LIC) mode. The processing circuitry selects a neighboring region for each of the plurality of first blocks. The selected neighboring region and the respective first block form a second block. The processing circuitry performs an inter prediction for the plurality of second blocks in parallel. The processing circuitry determines a set of LIC parameters for each of the plurality of first blocks based on the selected neighboring region of the respective first block and reconstructs the plurality of first blocks based on the sets of LIC parameters.

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San Jose, CA, United States of America

Meng Xu