Abstract: Method and apparatus for coding system using affine motion model are disclosed. According to one method, a neighbouring block set of the current block comprising multiple spatial neighbouring blocks and one or more collocated blocks is determined for the current block. One or more constructed affine MVP candidates are derived for an affine MVP candidate list based on CP (control-point) MVs (motion vectors) at multiple spatial neighbouring blocks and said one or more collocated blocks. One constructed affine MVP candidate without one temporal MV is checked and inserted into the affine MVP candidate list before any constructed affine MV with one temporal MV. The current block or motion information of the current block is then encoded or decoded based on the affine MVP candidate list.

Abstract: Aspects of the disclosure include a video encoding device that includes a processing circuit configured to receive a first block corresponding to a first color space component and a second block corresponding to a second color space component. The processing circuit is configured to determine transform settings for processing a first transformed block and a second transformed block corresponding to the first and second blocks, respectively. The processing circuit is configured to generate a first syntax element set to be signaled in association with the first color space component, and to generate a second syntax element set to be signaled in association with the second color space component, where the first syntax element set indicates a first transform setting for processing the first transformed block, and the second syntax element set indicates a second transform setting for processing the second transformed block.

Abstract: A video coder that constrains the total number of regular bins used for entropy coding syntax elements of a current block is provided. The video coder entropy encodes or decodes the syntax elements selectively as either regular bins using context modeling or as bypass bins without context modeling. A constraint is specified to limit a total number of regular bins used for entropy coding the syntax elements of the current block. There may be no constraint limiting a number of regular bins specific to an individual syntax element of the current block.

Abstract: Video processing methods and apparatuses in a video coding system include receiving input video data of a current block in a current picture, determining whether a transform skip mode is enabled for the current picture, signaling or parsing a syntax element associated with a size constraint for enabling the transform skip mode in a SPS referred to by the current picture when the transform skip mode is enabled, determining whether the transform skip mode is applied to the current block when the current block satisfies the size constraint, processing residues of the current block according to the transform skip mode when the transform skip mode is applied to the current block, and encoding or decoding the current block. An enabling flag is signaled in a high-level syntax set or parsed from the high-level syntax set to determine whether the transform skip mode is enabled for the current picture.

Abstract: Methods and apparatuses for processing video data include receiving input data associated with a current video picture, dividing the current video picture into non-overlapping rectangular tiles, grouping the tiles in the current video picture into tile groups, and encoding or decoding video data in the tile groups within the current video picture. According to one embodiment, each tile group is composed of an integer number of tiles, and shapes of all the tile groups are constrained to be rectangle. According to one embodiment, a flag is used to indicate whether one or more in-loop filtering operations are performed across tile group boundaries.

Abstract: A video processing method for a video encoder or decoder comprises receiving input data of a current chroma block in a current picture coded in a 4:2:2 color format, determining a luma mode of a luma block corresponding to the current chroma block, mapping the luma mode to a mapped intra mode of the current chroma block, selectively replacing the mapped intra mode by wide angle intra prediction mapping based on a width to height ratio of the current chroma block, deriving an intra predictor according to the mapped intra mode after wide angle intra prediction mapping, and encoding or decoding the current chroma block according to the intra predictor. The mapped intra mode is mode 57 when the luma mode is mode 61 and the mapped intra mode is mode 55 when the luma mode is mode 57.

Abstract: Methods and apparatus for Adaptive Loop Filter (ALF) processing of reconstructed video are disclosed. According to one method, clipping values for the ALF processing are determined depending on a bit depth of a center reconstructed pixel. A current ALF output for the current block is derived, where the current ALF output comprises a weighted sum of clipped differences of original differences and each of the original differences is calculated between a first reconstructed pixel at a non-center filter location and the center reconstructed pixel, and each of the original differences is clipped according to a corresponding clipping value to form one clipped difference. In another method, a target clipping value is always signaled at an encoder side or parsed at a decoder side even if the target clipping value is zero. In another method, the clipping values are encoded or decoded using a fixed-length code.

Abstract: Exemplary video processing methods and apparatuses for encoding or decoding a current block by bi-directional prediction. Multiple weight sets are utilized for blending List 0 and List 1 predictors, and the selection among multiple weight sets may be implicitly determined based on video information. Each weight set is composed of multiple candidate weights, and one candidate weight is selected for the current block. A weight pair associated with the selected weight for the current block is used for weighted averaging List 0 and List 1 predictors of the current block to generate a final inter predictor. The video processing methods and apparatuses encode or decode the current block according to the final inter predictor of the current block.

Abstract: A method of video coding with reduced implementation cost by reusing transform coefficient buffer palette for palette coding is disclosed. If the current prediction mode is an Intra prediction mode or the Inter prediction mode, information related to transform coefficients for prediction residual of the current block resulted from Intra prediction or Inter prediction is stored in the transform coefficient buffer. If the current prediction mode is the palette coding mode, information related to palette data associated with the current block is stored in the transform coefficient buffer. The current block is then encoded or decoded based on the information related to the transform coefficients if the current block is coded in the Intra prediction mode or the Inter prediction mode, or the information related to the palette data stored in the transform coefficient buffer if the current prediction mode is the palette coding mode.

Abstract: Method and apparatus of coding a video sequence are disclosed, wherein Reference Picture Resampling (RPR) mode is included as a coding tool. According to the method, a bitstream corresponding to encoded data of the video sequence is generated or received, where the bitstream includes one or more syntaxes related to the RPR mode when the RPR mode is enabled, and scaling information for the RPR mode is derived using first information including said one or more syntaxes, and wherein said one or more syntaxes are constrained by taking into account a value corresponding to Max(8, (minimum coding block size for a luma component)). A target picture of the video sequence is encoded or decoded utilizing the scaling information when the RPR mode is enabled for the target picture.

Abstract: Method and apparatus of coding a video sequence, are disclosed. According to the method, a bitstream corresponding to encoded data of the video sequence is generated at an encoder side or received at a decoder side, where the bitstream complies with a bitstream conformance that one or more constraints are satisfied. The constraints are related to a set of RPR (Reference Picture Resampling) parameters including scaling window width or height of a current picture, scaling window width or height of a reference picture, current picture width or height, and maximum picture width or height specified for the video sequence. Scaling information for the RPR mode is derived using the set of RPR parameters. A target picture of the video sequence is then encoded at the encoder side or decoded at the decoder side by utilizing the scaling information when the RPR mode is enabled for the target picture.

Abstract: Video data processing methods and apparatuses comprise receiving input data associated with a current chroma block, determine a luma Quantization Parameter (QP) of a collocated luma block, reuse the luma QP of the collocated luma block to derive a chroma QP for the current chroma block, and encode or decode one or more Transform Units (TUs) associated with the current chroma block using the chroma QP. The collocated luma block is a block that covers a collocated sample of one predefined sample of the current chroma block, and an example of the predefined sample is a center sample of the current chroma block. The input video data is partitioned according to two separate Coding Unit (CU) partitioning structures for luma and chroma components when dual tree coding is enabled.

Abstract: Method and apparatus for constrained mode signaling are disclosed. According to one method, a plurality of mode syntaxes are used to signal a current mode used for the current block. If one or more of the plurality of candidate modes are unavailable according to one or more conditions related to the current block, signaling a mode syntax is skipped at the video encoder side or parsing the mode syntax is skipped at the video decoder side. In one embodiment, a regular flag indicating on or off of a regular Merge mode or Skip mode is not signaled if Merge mode with MVD (MMVD) mode, Affine mode, subblock Temporal Motion Vector Prediction (SbTMVP) mode, Combined Inter and Intra Prediction (CIIP) Merge mode, and Triangle Prediction Mode (TPM) are disabled as indicated by an SPS flag.

Abstract: Encoding methods and apparatuses include applying a Cross-Component Adaptive Loop Filter (CCALF) processing on a current picture based on CCALF coefficients signaled in one or more Adaptive Loop Filter (ALF) Adaptation Parameter Sets (APSs) to refine one or more chroma components according to a luma component, signaling two ALF signal flags and two CCALF signal flags in each ALF APS or parsing two ALF signal flags and two CCALF signal flags from each ALF APS, and encoding or decoding the current picture. Values of the two ALF signal flags and the two CCALF signal flags in each ALF APS are not all equal to 0 to ensure none of the ALF APS is an empty APS.

Abstract: A method and apparatus of prediction for video coding are disclosed. According to the method, when the Intra Sub-Partition (ISP) mode is applied to a block, the block is partitioned into multiple sub-blocks horizontally or vertically. A target horizontal transform and a target vertical transform are determined from a candidate transform set for each of the multiple sub-blocks according to a target setting belonging to a setting group comprising unified setting and block setting. The target horizontal transform and the target vertical transform selected are then applied to each of the multiple sub-blocks. According to another method, a target horizontal and vertical transform are determined from a candidate transform set without a transform index for the current block according to unified setting, wherein the unified setting comprises two or more Intra modes or Intra-related modes.

Abstract: A method and apparatus of entropy coding of coding symbols using Context-Based Adaptive Binary Arithmetic Coder (CABAC) are disclosed. The method operates by applying context-adaptive arithmetic encoding or decoding to a current bin of a binary data of a current coding symbol according to a current binarized probability value of the current bin and a current range associated with a current state of the context-adaptive arithmetic encoding or decoding; deriving an LPS probability index corresponding to an inverted current binarized probability value or the current binarized probability value, depending on whether the current binarized probability value of the current bin is greater than or equal to 2k?1, k being a positive integer; deriving a range index for identifying one range interval containing the current range; and deriving an LPS range using one or more mathematical operations.

Abstract: A method and apparatus of video coding are disclosed. A piece-wise linear mapping is derived to map a target luma sample from a first signal domain to a second signal domain, or vice versa. The piece-wise linear mapping process comprises determining first pivot points for performing video encoding or decoding of the luma samples using a piece-wise linear mapping. The first pivot points are determined so that: if a target mapped pivot point corresponding to one first pivot point in the second signal domain has a multiple of the target interval value, the target mapped pivot point and a next mapped pivot point can be located in a same second segment; and otherwise, the target mapped pivot point and the next mapped pivot point cannot be located in the same second segment.

Abstract: An intra prediction method comprises receiving input data of a current block in a current picture, deriving reference samples of the current block from boundary samples, selecting a matrix for the current block, generating intermediate predicted samples by multiplying the reference samples and the matrix, and clipping the intermediate predicted samples before up-sampling. The intra prediction method further comprises performing an up-sampling process on the clipped intermediate predicted samples to generate predicted samples for the current block, and encoding or decoding the current block according to the predicted samples of the current block.

Abstract: A method and apparatus or decoding prediction residues in a video coding system are disclosed. According to this method, a first syntax element to a fourth syntax element are signalled or parsed in a first coding pass for at least sub-block. The current residual block is encoded or decoded using information comprising the first syntax element, the second syntax element, the third syntax element, and the fourth syntax element. The first syntax element indicates whether an absolute value of a current transform coefficient level is greater than 0. The second syntax element indicates whether the absolute value of the current transform coefficient level is greater than 1. The third syntax element indicates a parity of the current transform coefficient level. The fourth syntax element indicates whether the absolute value of the current transform coefficient level downward shifted by 1 is greater than 1.

Abstract: A method for performing transform skip mode (TSM) in a video decoder is provided. A video decoder receives data from a bitstream to be decoded as a plurality of video pictures. The video decoder parses the bitstream for a first syntax element in a sequence parameter set (SPS) of a current sequence of video pictures. When the first syntax element indicates that transform skip mode is allowed for the current sequence of video pictures and when transform skip mode is used for a current block in a current picture of the current sequence, the video decoder reconstructs the current block by using quantized residual signals that are not transformed.