Abstract: Methods and apparatus of motion compensation using the bi-directional optical flow (BIO) techniques are disclosed. According to one method of the present invention, the BIO process is applied to encode or decode bi-directional current block in Merge mode only or in AMVP (advanced motion vector prediction) mode only. According to another method, the BIO process conditionally to encode or decode the current block depending on a jointly-coded flag if the current block is coded using a bi-prediction mode. According to yet another method, x-offset value vx and y-offset value vy for the current block are added to the current motion vector to form a final motion vector. The final motion vector is then used as a reference motion vector for following blocks. In still yet another method, the BIO process is applied to the chroma component.

Abstract: Aspects of the disclosure provide a method and an apparatus for video coding. A processing circuitry determines a process unit size for a decoder-side motion vector refinement (DMVR). Then, the processing circuitry enables an application of the DMVR on a current block when a size of the current block is smaller than or equal to the process unit size; and disables the application of the DMVR on the current block when the size of the current block is larger than the process unit size. In an example, the application of the DMVR refines the motion vectors with or without a template block.

Abstract: Methods and apparatus for in-loop processing of reconstructed video are disclosed. According to one method, a virtual boundary is determined for to-be-processed pixels in the current picture, where the virtual boundary is aligned with block boundaries and at least one to-be-processed pixel on a first side of the virtual boundary requires one or more second pixels on a second side of the virtual boundary. According to the method, the in-loop processing is modified if a target to-be-processed pixel requires at least one second pixel from the second side of the virtual boundary and the modified in-loop processing eliminates the need for any second pixel on the second side of the virtual boundary. According to another method, the operations of block classification are changed when part of the required pixels in one 10×10 window used in classification are at the other side of virtual boundaries.

Abstract: A methods and apparatus for adaptive data dependency between corresponding blocks partitioned from separate partition trees according to an embodiment of the present invention are disclosed. The data dependency between different tree structures is allowed when the tree structures are mutually inclusive. When the splitting is not used in one tree or when splitting is used in one tree and the same splitting or no split is used in the other tree, the data dependency between different tree structures is allowed. When the splitting in different tree structures are different, then the data dependency between different tree structures is disallowed. For each leaf CU in chroma tree, it should include one or more complete luma leaf CUs or it is completely included in one luma leaf CU, when the data dependency between different tree structures is allowed. Otherwise, then the data dependency between different tree structures is disallowed.

Abstract: Video encoding methods and apparatuses for Sum of Absolute Transformed Difference (SATD) computation by folded Hadamard transform circuits include splitting a current block into SATD blocks, receiving input data associated with a first block of a first SATD block in a first cycle and receiving input data associated with a second block of the first SATD block in a second cycle, and performing calculations for the first block by shared Hadamard transform circuits in the first cycle and performing calculations for the second block by the shared Hadamard transform circuits in the second cycle. Each shared Hadamard transform circuit is a first part of each folded Hadamard transform circuit. The video encoding methods and apparatuses further perform calculations for the entire SATD block by a final part of each folded Hadamard transform circuit to generate a final SATD result of the first SATD block for encoding.

Abstract: Methods and apparatus for video coding using non-adjacent affine candidates are provided. According to this method, one or more neighboring MVs (motion vectors) are determined from one or more non-adjacent affine-coded neighbors of the current block. CPMVs (Control-Point Motion Vectors) are determined based on said one or more neighboring MVs, wherein if a target neighboring block associated with one target neighboring MV (Motion Vector) is outside an available region, a derived CPMV) is generated to replace the target neighboring MV. An affine merge list or an affine AMVP (Advanced Motion Vector Prediction) list having said one or more neighboring MVs as one non-adjacent affine candidate is generated, wherein said one non-adjacent affine candidate generates a non-adjacent affine predictor using motion information according to the CPMVs. The current block is encoded or decoded using a motion candidate selected from the affine merge list or the affine AMVP list.

Abstract: A method and apparatus for video coding. According to the method, a set of candidates associated with coding modes or mode parameters are determined. Boundary matching costs associated with the set of candidates are determined, where each of the boundary matching costs is determined for one target candidate of the set of candidates. The costs are calculated by using reconstructed or predicted samples of the current block and one or more neighboring blocks of the current block. Each of the boundary matching costs is calculated using one target configuration selected from a plurality of configurations. A final candidate is selected from the set of candidates based on the boundary matching costs. The current block is encoded or decoded using the final candidate.

Abstract: Method and apparatus of Inter prediction for video coding are disclosed. When a sub-block motion compensation coding tool is selected for the current block, the method generates sub-block MVs (motion vectors) associated with multiple sub-blocks, which are included or contained in the current block, according to the sub-block motion compensation coding tool, constrains the sub-block MVs within a range to form constrained sub-block MVs, and applies motion compensation to the current block using the constrained sub-block MVs or applies motion compensation to the current block using one sub-block MV within the range around the primary MV in a second list if a corresponding sub-block MV in a first list is outside the range. In another method, motion compensation is applied to the current block only using reference pixels of reference sub-blocks within a primary reference block.

Abstract: An image or video processing method comprises receiving input data of a current block, mapping an MIP mode index to a default mode, and encoding or decoding the current block by referencing the default mode. Another image or video processing method comprises receiving input data of a current block coded or to be coded by an MIP mode, and parsing or signaling a transpose flag for the current block indicating whether transposing is applied in coding the current block. Reference samples of the current block are prepared from neighboring boundary samples according to the transpose flag. A matrix is selected to be multiplied to the reference samples to generate predicted samples. A transposing process is adaptively applied to the current block according to the transpose flag, and the predicted samples are used to encode or decode the current block.

Abstract: A method and apparatus use an Inter coding tool and OBMC (Overlapped Block Motion Compensation). According to one implementation, a method of video coding using OBMC (Overlapped Block Motion Compensation) operates by receiving input data associated with a current block, wherein the input data correspond to pixel data to be coded at an encoder side or coded data to be decoded at a decoder side, applying the OBMC to the current block depending on one or more constraints, and signaling an OBMC syntax conditionally at the encoder side or parsing the OBMC syntax conditionally at the decoder side for the current block, wherein the OBMC syntax indicates whether the OBMC is applied to the current block.

Abstract: According to one implementation, a method receives input data related to a current block in a current picture at a video encoder side or receiving a video bitstream comprising coded data of the current block at a video decoder side. When hen the MIP mode is applied to the current block, the method checks availability for a target reference boundary region comprising left reference boundary samples and top reference boundary samples, wherein the left reference boundary samples and the top reference boundary samples are checked jointly for the current block. The method further performs a padding process if an unavailable sample exists in the target reference boundary region, wherein the unavailable sample is padded with a default value or a sample value of an available sample and derives a reduced predictor, and encodes or decodes the current block using a MIP predictor derived from the reduced predictor.

Abstract: Various schemes pertaining to video coding parallelization techniques are described. An apparatus receives video data. The apparatus subsequently calculates a plurality of figures of merits (FOMs), each of the FOM representing how well a particular coding tool may perform in encoding the video data. The apparatus further determines a coding tool that may be suitable for encoding the video data by comparing the FOMs. In determining the coding tool, the apparatus utilizes time-interleaving techniques to parallelly process the video data. The video data may include an array of coding blocks, and the apparatus may receive the video data using a snake-like processing order scanning through the array of coding blocks.

Abstract: A video encoder receives raw pixel data to be encoded as a current block of a current picture of a video into a bitstream. The video encoder identifies multiple candidate bi-prediction positions for the current block, including a center position, a first set of offset positions, and a second set of offset positions. The first set of offset positions and the second set of offset positions interleave each other. The encoder computes distortion values for each of the candidate bi-prediction positions based on several possible weighting parameter values. The distortion values for the center position are based on each of the several possible weighting parameter values. The distortion values for the first set of offset positions are based on a first subset of the possible weighting parameter values. The distortion values for the second set of offset positions are based on a second subset of the possible weighting parameter values.

Abstract: Various schemes for managing search memory are described, which are beneficial in achieving enhanced coding gain, low latency, and/or reduced hardware for a video encoder or decoder. In processing a current block of a current picture, an apparatus determines a quantity of a plurality of reference pictures of the current picture. The apparatus subsequently determines, for at least one of the reference pictures, a corresponding search range size based on the quantity. The apparatus then determines, based on the search range size and a location of the current block, a search range of the reference picture, based on which the apparatus encodes or decodes the current block.

Abstract: A video coding system generating candidates for Merge Mode with Motion Vector Difference (MMVD) with reduced resource usage is provided. The system receives data to be encoded or decoded as a current block of a current picture of a video. The system identifies multiple MMVD candidates for different offset positions based on a merge candidate of the current block. The system generates reference samples for the identified MMVD candidates. The system reconstructs the current block or encodes the current block into a bitstream by using the generated reference samples. The system processes the MMVD candidates in separate groups: a first group of vertical MMVD candidates and a second group of horizontal MMVD candidates. The system generates the reference samples for the identified MMVD candidates by applying a vertical filter to source reference samples of horizontal MMVD candidates and then applying a horizontal filter to outputs of the vertical filter.

Abstract: Video encoding methods and apparatuses for frequency domain mode decision include receiving residual data of a current block, testing multiple coding modes on the residual data, calculating a distortion associated with each of the coding modes in a frequency domain, performing a mode decision to select a best coding mode from the tested coding modes according to the distortion calculated in the frequency domain, and encoding the current block based on the best coding mode.

Abstract: The techniques described herein relate to methods, apparatus, and computer readable media configured to receive compressed video data, wherein the compressed video data is related to a set of frames. A decoder-side predictor refinement technique is used to calculate a new motion vector for a current frame from the set of frames, wherein the new motion vector estimates motion for the current frame based on one or more reference frames. An existing motion vector associated with a different frame from a motion vector buffer is retrieved. The new motion vector is calculated based on the existing motion vector using a decoder-side motion vector prediction technique, such that the existing motion vector is in the motion vector buffer after calculating the new motion vector.

Abstract: Video encoding methods and apparatuses include collecting statistics data, determining a matrix and vector representing a set of linear equations, solving the matrix and vector by a novel Gaussian elimination method to derive optimal parameter adjustments for an affine mode or adaptive loop filter coefficients, and encoding the current block by the affine mode or encoding one or more blocks by applying ALF filtering. Embodiments of the novel Gaussian elimination method reduce the critical path of entry operations in each row elimination step from one reciprocal, two multiplication, and one addition operations to one reciprocal, one multiplication, and one addition operations, or one multiplication and one addition operations.

Abstract: A methods and apparatus for adaptive data dependency between corresponding blocks partitioned from separate partition trees according to an embodiment of the present invention are disclosed. The data dependency between different tree structures is allowed when the tree structures are mutually inclusive. When the splitting is not used in one tree or when splitting is used in one tree and the same splitting or no split is used in the other tree, the data dependency between different tree structures is allowed. When the splitting in different tree structures are different, then the data dependency between different tree structures is disallowed. For each leaf CU in chroma tree, it should include one or more complete luma leaf CUs or it is completely included in one luma leaf CU, when the data dependency between different tree structures is allowed. Otherwise, then the data dependency between different tree structures is disallowed.

Abstract: Method and apparatus of video coding using decoder derived motion information based on bilateral matching or template matching are disclosed. According to one method, merge index for merge candidate group comprising bilateral matching merge candidate and/or template matching merge candidate are signalled using different codewords. According to another method, the first-stage MV or the first-stage MV pair is used as an only initial MV or MV pair or used as a central MV of search window for second-stage search. According to yet another method, after the reference template for a first reference list is found, the current template is modified for template search in the other reference list. According to yet another method, the sub-PU search is disabled for the template search. According to yet another method, block difference calculation is based on reduced bit depth during MV search associated with the decoder-side MV derivation process.