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

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 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 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.

Methods and devices for video encoding are provided. In the method, the device divides a current picture into one or more coding units; determines, for a current luma transform block in a current coding unit of the one or more coding units, whether a first variable indicating an intra subpartition (ISP) split type equals ISP_NO_SPLIT. In response to determining the first variable equals ISP_NO_SPLIT, the device determines a luma block flag context index for a luma block flag of the current luma transform block as being equal to zero or one without determining whether the current luma transform block is smaller than the current coding unit. In response to determining the first variable does not equal ISP_NO_SPLIT, the device determines the luma block flag context index based on a second variable of a previous luma transform unit in the current coding unit.

Methods, apparatuses, and non-transitory computer-readable storage mediums are provided for video decoding. The method includes: constructing, by a decoder, a first merge list comprising a plurality of candidates, based on a merge list construction process for regular merge prediction, wherein each one of the plurality of candidates is a motion vector comprising a List 0 motion vector, or a List 1 motion vector, or both; receiving, by the decoder, a first/second index value to indicate a first/second candidate that is chosen from the first merge list; receiving, by the decoder, a first/second binary flag that is coded using a first/second context-adaptive binary arithmetic coding (CABAC) context modeling method to indicate whether a List 0 motion vector of the first/second candidate or a List 1 motion vector of the first/second candidate is selected for a first PU of the geometric prediction.

Methods and apparatuses for video coding with triangle prediction

A method for video encoding is provided. The method may be applied in an encoder and includes: determining, for a first coding block, a quantization parameter and a quantized level; deriving a scale value by scaling the quantization parameter by a scale factor, determining a plurality of parameters associated with a coding unit (CU); obtaining a plurality of bit-shifts by bit-shifting the plurality of parameters; and obtaining a plurality of coefficients associated with the CU based on the quantized level, the scale value, and the plurality of bit-shifts.

Methods and devices for quantization and de-quantization design in video coding

A method for video decoding is provided. The method may be applied in a decoder and includes: receiving a video bitstream comprising a quantization parameter and a quantized level; deriving a scale value by scaling the quantization parameter by a scale factor; determining a plurality of parameters associated with a coding unit (CU); obtaining a plurality of bit-shifts by bit-shifting the plurality of parameters; and obtaining a plurality of coefficients associated with the CU based on the quantized level, the scale value, and the plurality of bit-shifts.

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Tsung-Chuan Ma