Beijing Dajia Internet Information Technology Co., Ltd.

Tsung-Chuan Ma

Xianglin Wang

Xiaoyu Xiu

Yi-Wen Chen

Hong-Jheng Jhu

Bing Yu

Shuiming Ye

Wei Chen

Che-Wei Kuo

Yun-fei Zheng

Methods and apparatuses are provided for video coding with lossless coding modes. The method includes: partitioning a video picture into a plurality of CUs comprising a lossless CU; determining a residual coding block size of the lossless CU; and in response to determining that the residual coding block size of the lossless CU is greater than a predefined maximum value, splitting the residual coding block into two or more residual blocks for residual coding.

Lossless coding modes for video coding

A method for video coding is provided. The method includes: determining a signaling of merge modes for deriving motion information of a current block, where the merge modes include: regular merge mode and extended merge modes; and deriving motion information of the current block using the regular merge mode, upon determining that the signaling of merge modes includes a positive signal of regular merge mode.

Methods and apparatuses for signaling of merge modes in video coding

Methods and apparatuses are provided for video coding. The method includes: partitioning a picture into a plurality of coding units; partitioning a coding unit of the plurality of coding units into two geometric partitions; and performing a predetermined number of motion vector comparison operations during a process of constructing a merging candidate list for either of the two geometric partitions.

Methods and apparatuses for video coding using geometric partition

A method of video coding comprises independently generating a respective intra prediction for each of a plurality of corresponding sub-partitions. Each respective intra prediction is generated using a plurality of reference samples from a current coding block. Illustratively, no reconstructed sample from a first sub-partition of the plurality of corresponding sub-partitions is used to generate a respective intra prediction for any other sub-partition of the plurality of corresponding sub-partitions, and each of the plurality of corresponding sub-partitions has a width less than or equal to 2.

Video coding using intra sub-partition coding mode

A method, apparatus, and a non-transitory computer-readable storage medium for decoding a video signal are provided. A decoder may receive, through a bitstream, arranged syntax elements in sequence parameter set (SPS) level. The arranged syntax elements in the SPS level are arranged so that functions of related syntax elements are grouped in versatile video coding (VVC) syntax at a coding level. The decoder may receive, through the bitstream and in response to multiple syntax elements satisfy a predefined condition, a second syntax element immediately after the multiple syntax elements. The decoder may perform, through the bitstream, a related syntax element function to video data from the bitstream in accordance with the multiple syntax elements and the second syntax element.

High-level syntax for video coding

Methods, apparatuses, and non-transitory computer-readable storage mediums are provided for coding a video signal. A method includes obtaining a first reference picture and a second reference picture associated with a video block; obtaining first prediction samples of the video block from the first reference picture; obtaining second prediction samples of the video block from the second reference picture; obtaining padded prediction samples, and obtaining horizontal and vertical gradient values of the first prediction samples and the second prediction samples based on the padded prediction samples; obtaining motion refinements for samples in the video block based on the horizontal and vertical gradient values; and obtaining bi-prediction samples of the video block based on the motion refinements.

Methods and apparatuses for prediction refinement with optical flow

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.

Methods and apparatus for prediction refinement with optical flow

Methods are provided for video coding. The method includes: partitioning video pictures into a plurality of coding units (CUs), at least one of which is further partitioned into two prediction units (PUs) including at least one geometric shaped PU; obtaining a first merge list including a plurality of candidates, each including one or more motion vectors; and obtaining a uni-prediction merge list for the geometric shaped PU by selecting the one or more motion vectors directly from the first merge list.

Methods and apparatus of video coding for triangle prediction

Methods, apparatuses, and non-transitory computer-readable storage mediums are provided for encoding a video signal. A method includes obtaining a first reference picture associated with a video block in a current picture within the video signal and a first motion vector (MV) from the video block to a reference block; obtaining first prediction samples of the video block generated from samples of the reference block; controlling internal bit-depths of internal prediction refinement with optical flow (PROF) parameters by performing a shift operation; obtaining a prediction refinement value for the first prediction sample based on the horizontal and vertical gradient values and the horizontal and vertical motion differences; obtaining second prediction samples associated with a second MV and a prediction refinement value for a second prediction sample; and obtaining a final prediction sample of the video block based on the first prediction sample, the second prediction sample, and the prediction refinement values.

Methods, apparatuses, and non-transitory computer-readable storage mediums are provided for encoding a video signal. A method may include obtain a first reference picture and a second reference picture associated with a video block, wherein the first reference picture is before a current picture and the second reference picture is after the current picture in display order; obtain first prediction samples of the video block from the first reference picture; obtain second prediction samples of the video block from the second reference picture; obtain padded prediction samples; obtain horizontal and vertical gradient values of the first prediction samples and the second prediction samples based on the padded prediction samples; obtain motion refinements for samples in the video block based on the horizontal and vertical gradient values; and obtain bi-prediction samples of the video block based on the motion refinements.

Methods, apparatuses, and non-transitory computer-readable storage mediums are provided for video decoding. A decoder may receive a video stream. The decoder may receive a control flag in a slice header level. The decoder may receive at least one syntax element in the slice header level. The decoder may entropy decode the video bitstream based on the control flag and the at least one syntax element.

Residual and coefficients coding for video coding

A method for video encoding is provided. The method includes obtaining, by an encoder, a plurality of blocks from a video picture, wherein each of the plurality of blocks is to be encoded by an intra prediction mode or an inter prediction mode; in response to a first pre-defined condition being satisfied, determining, by the encoder, that a current block in the plurality of blocks is eligible for an application of Decoder-side Motion Vector Refinement (DMVR); in response to the current block being eligible for both applications of DMVR and Bi-Directional Optical Flow (BDOF), determining, by the encoder, whether a pre-defined criterion based on mode information of the current block is satisfied; avoiding, by the encoder in response to the pre-defined criterion being satisfied, applying BDOF to a subblock in the current block; and outputting, by the encoder by a bitstream, prediction mode information of the current block.

Methods and devices for selectively applying bi-directional optical flow and decoder-side motion vector refinement for video coding

Methods and devices for video encoding are provided. In the method, the device determines, for a current luma transform block in a coding unit, whether an intra subpartition (ISP) split type is an ISP mode. In response to determining that the intra subpartition split type is not the ISP mode, the device determines a first context index for a Coded Block Flag (CBF) flag of the current luma transform block as being equal to zero or one, where the CBF flag specifies whether the current luma transform block comprises one or more transform coefficient levels not equal to zero. In response to determining that the intra subpartition split type is the ISP mode, the device determines the first context index based on whether a current transform unit is a first one to be parsed in the coding unit. The device encodes the CBF flag based on the first context index.

Coding of transform coefficients in video coding

Methods and devices for video coding are provided. In the method, the device determines, for a current luma transform block in a coding unit, whether an intra subpartition (ISP) split type is an ISP mode. In response to determining that the intra subpartition split type is not the ISP mode, the device determines a first context index for a Coded Block Flag (CBF) flag of the current luma transform block as being equal to zero or one, where the CBF flag specifies whether the current luma transform block comprises one or more transform coefficient levels not equal to zero. In response to determining that the intra subpartition split type is the ISP mode, the device determines the first context index based on whether a current transform unit is a first one to be parsed in the coding unit. The device decodes the CBF flag based on the first context index.

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Tsung-Chuan Ma