Abstract: An intra prediction method comprises receiving input data of a current block in a current picture, deriving multiple Most Probable Modes (MPMs) to be included in a MPM list for the current block, setting remaining intra prediction modes as non-MPMs, and encoding or decoding the current block according to a current intra prediction mode selecting from the MPMs and non-MPMs. The first MPM in the MPM list is Planar mode for blocks coded or to be coded in intra prediction, and one or more other MPMs in the MPM list are derived according to a number of available angular mode of one or more neighboring blocks of the current block.

Abstract: Video processing methods and apparatuses include receiving input data associated with a current picture composed of multiple Coding Tree Units (CTUs) for encoding or decoding, partitioning the current picture into multiple subpictures, determining one or more reference pictures for inter coding the current picture, and encoding or decoding one or more blocks in one or more CTUs of the current picture by inter coding using the one or more reference pictures. Each of the reference pictures used for inter coding the current picture has a same CTU size as that of the current picture when the reference picture is not an Inter Layer Reference Picture (ILRP) containing one subpicture.

Abstract: Method and apparatus for encoding and decoding prediction residues in a video coding system also disclosed. At the decoder side, a Rice parameter for the target transform coefficient is determined based on a local sum of absolute levels of neighboring transform coefficients of the target transform coefficient. A dependent quantization state is determined and a zero-position variable is determined based on the dependent quantization state and the Rice parameter. One or more coded bits associated with a first syntax element for the target transform coefficient in a transform block are parsed and decoded using one or more codes including a Golomb-Rice code with the Rice parameter, where the first syntax element corresponds to a modified absolute level value of the target transform coefficient. An absolute level value of the target transform coefficient is derived according to the zero-position variable and the first syntax element.

Abstract: A method and apparatus for encoding or decoding transform coefficients in a video coding system are disclosed. According to this method, a region after zero-outis determined. A remaining number of context-coded bins is determined for the current TB based on a size of the region after zero-out. The current TB is encoded or decoded using context-based coding with a constraint based on the remaining number of context-coded bins. According to another method, a remaining number of context-coded bins is determined for the current TB based on the last significant CG index.

Abstract: A video system that applies constraints on block partitioning is provided. The system receives a partitioning control parameter from a bitstream specifying a maximum block size for enabling ternary-tree split that is constrained to be 64 or smaller. The system receives data from a bitstream for a block of pixels to be decoded as a current block of a current picture of a video. The system splits the current block into one or more partitions recursively, wherein ternary split is disallowed for a partition of the current block unless the partition is less than or equal to the maximum block size. The system reconstructs the one or more partitions of the current block.

Abstract: Video processing methods comprise receiving input data of a current block, checking whether the current block is a root block by considering one or more predefined criteria, applying a mode constraint, a chroma split constraint, or both the mode and chroma split constraints to the current block if the current block is set to be a root block, and encoding or decoding the current block. The mode constraint restricts all blocks split from the current block to be processed by a same prediction mode and the chroma split constraints prohibits chroma components of the current block to be further partitioned while allowing a luma component of the current block to be partitioned into smaller blocks.

Abstract: A method and apparatus of video coding operate by receiving input data associated with a current data unit in a current picture, wherein the current data unit includes a luma component and a chroma component and the current data unit includes a luma data unit and a chroma data unit. The operation proceeds by splitting the luma data unit and the Chroma data unit using one shared tree until the luma data unit and the chroma data unit reach a stop node, encoding or decoding the stop node as a leaf CU (coding unit) if the stop node is greater than M×N for the luma component, M and N are positive integers, and signalling or parsing a prediction mode for the stop node if the stop node is smaller than or equal to M×N for the luma component.

Abstract: A method and apparatus for video coding utilizing a current block, a maximum side of the transform block of the current block corresponds to 64. A scaling matrix is derived from elements of an 8×8 base scaling matrix, where the elements in a bottom-right 4×4 region of the 8×8 base scaling matrix are skipped, either not signaled or set to zero. According to another method, a current block belongs to a current picture in a first color format that has only a first color component. A first scaling matrix is signaled at the video encoder side or parsed at the video decoder side for the first color component of the current block. Signaling any second scaling matrix is disabled at the video encoder side or parsing any second scaling matrix is disabled at the video decoder side for a second or third color component of the current block.

Abstract: Video processing methods and apparatuses in a video encoding or decoding system for processing residual data of transform blocks. A current transform block in a video picture is divided into multiple sub-blocks, and each sub-block in the current transform block is entropy encoded or decoded using multiple sub-block coding passes. Each transform coefficient level in each sub-block is visited once according to a pre-defined scanning order in each sub-block coding pass. Two or more syntax elements associated with transform coefficient levels in the current transform block are aggregated and coded in one single sub-block coding pass. The video processing method is applied if the current transform block contains at least one non-zero transform coefficient level and the current transform block is coded in Transform Skip Mode (TSM) according to some embodiments.

Abstract: A method and apparatus for video coding are disclosed. According to this method, a current block is received at an encoder side or compressed data comprising the current block is received at a decoder side, where the current block is partitioned into two geometric prediction units. Motion information for the two geometric prediction units is determined. Weighting information for the two geometric prediction units is determined. A motion storage type variable based on the weighting information is determined, where the motion information associated with the current block is stored according to a value of the motion storage type variable. A geometric predictor for the current block is generated by blending two geometric predictors according to the weighting information, where the two geometric predictors are derived for the two geometric prediction units using the motion information associated with the current block.

Abstract: A video decoder receives to-be-decoded data from a bitstream for a block of pixels to be decoded as a current block of a current picture of the video. The video decoder generates a first prediction of the current block based on a first prediction mode that is selected from a first candidate list. The video decoder generates a second prediction of the current block based on a second prediction mode that is selected from a second candidate list. The video decoder generates a combined prediction for the current block based on the first prediction and the second prediction. The video decoder reconstructs the current block by using the combined prediction.

Abstract: A method for adaptive MV precision is disclosed. According to one embodiment, whether to use or not to use the adaptive MV precision for a current block is determined according to a prediction mode/partition type of the current block. If the adaptive MV precision is used, a current MV precision is determined for a current MV of the current block, and the current MV is encoded or decoded at the current MV precision. If the adaptive MV precision is not used, the current MV is encoded or decoded at a finer MV precision. In another embodiment, a value of a current adaptive MV precision flag is selected for a current block to indicate whether to use or not to use the adaptive MV precision for a current block according to a prediction mode/partition type of the current block.

Abstract: A method and apparatus of prediction for video coding using MH (Multiple Hypothesis) mode are disclosed. According to this method, a block is partitioned into a first partition and a second partition. A first candidate and a second candidate are derived for the first and second partitions respectively. At least one of the first candidate and the second candidate is derived using a candidate list derived for a regular Merge mode (or also called as normal Merge mode). An MH prediction generated by blending a first prediction corresponding to a first candidate and a second prediction corresponding to a second candidate, and the MH prediction is applied to a part of the current block.

Abstract: A method and apparatus of Inter prediction for video coding using UMVE (Ultimate Motion Vector Expression) are disclosed. According to this method, a base candidate is selected from an original Inter candidate list, where the base candidate has a base prediction direction. One or more extended candidates are derived by adding one or more offsets to the base candidate, where said one or more extended candidates have a same prediction direction as the base prediction direction. The extended candidates are then inserted into the original Inter candidate list to form an extended Inter candidate list for encoding or decoding. According to another method, the UMVE mode is treated as an additional AMVP (Advanced Motion Vector Prediction) mode.

Abstract: Video processing methods and apparatuses for processing a current block in a current picture include receiving input data of the current block, determining a reference picture, determining whether picture sizes of the current and reference pictures are different, determining whether horizontal wraparound motion compensation is enabled for predicting the current block, performing motion compensation for the current block to obtain a reference block from the reference picture, and encoding or decoding the current block according to the reference block. Horizontal wraparound motion compensation is disabled when the picture sizes of the current and reference pictures are different.

Abstract: Video processing methods and apparatuses in a video encoding or decoding system for processing residual data of transform blocks. A current transform block in a video picture is divided into multiple sub-blocks, and each sub-block in the current transform block is entropy encoded or decoded using multiple sub-block coding passes. Each transform coefficient level in each sub-block is visited once according to a pre-defined scanning order in each sub-block coding pass. Two or more syntax elements associated with transform coefficient levels in the current transform block are aggregated and coded in one single sub-block coding pass. The video processing method is applied if the current transform block contains at least one non-zero transform coefficient level and the current transform block is coded in Transform Skip Mode (TSM) according to some embodiments.

Abstract: Methods and apparatus for video coding are disclosed. According to one method, a bitstream is generated or received, where the bitstream includes a first syntax and a second syntax. The first syntax is related to a target number of bits used to represent a set of third syntaxes and each third syntax specifies one subpicture ID for one subpicture in a set of subpictures. The second syntax is related to a total number of subpictures in the set of subpicture, where a first number that can be represented by the target number of bits is equal to or greater than the total number of subpictures. According to another method, the subpicture ID syntaxes have different values for different subpictures.

Abstract: The techniques described herein relate to methods, apparatus, and computer readable media configured to encode and/or decode video data. A prediction mode is determined for intra prediction coding a current data unit, where the determined prediction mode is a most probable mode of a plurality of most probable modes determined for the current data unit. The MPM information of the determined prediction mode is encoded using a coding bin, including context encoding the bin based on whether the bin is a first coding bin for the MPM information.

Abstract: A method and apparatus for video coding incorporating enhanced multiple transform (EMT) are disclosed. According to one method, the number of candidates for EMT in the horizontal direction or vertical direction is reduced depending on the current block size. According to another method, an EMT flag, one or more EMT indices or both are signalled only if the total number of non-zero coefficients in at least a part of the 2D coefficient block is greater than a threshold, where the threshold is equal to 1 or larger. A method and apparatus for video coding using non-separable secondary transform (NSST) are disclosed. According to this method, a total number of non-zero first coefficients in a partial block of the 2D coefficient block is determined and used to determine whether to apply the NSST process.

Abstract: A method and apparatus of Inter prediction for video coding are disclosed. According to one method, a sub-block motion vector prediction (MVP) mode is turned off for small size coding units (CUs). In another method, if the neighbouring reference block for a current coding unit (CU) is in a root CU region, the neighbouring reference block is not used to derive a Merge candidate or a modified neighbouring reference block on the shared boundary of the root CU is used to derive the Merge candidate for the current block. In yet another method, a shared sub-block Merge candidate list is derived for sub-CUs within a root CU region or an MER (Merge estimation region). If a neighbouring reference block is within the same MER as a current sub-CU, the neighbouring reference block is not used for deriving a candidate for the shared sub-CU Merge list.