Abstract: A method comprising obtaining a bitstream, the bitstream comprises a transform unit syntax and a coding unit syntax, the transform unit syntax includes a value of a first flag and a value of a second flag related to, respectively, a first chroma transform block and a second chroma transform block of a current transform unit or a current sub-transform unit within the current transform unit, the first or second flag specifies whether the first or second chroma transform block contains at least one transform coefficient levels not equal to 0, the coding unit syntax includes a value of a third flag specifying whether a transform tree structure is present or not; and deriving a value of a fourth flag based on the values of the first, second, and third flags, the fourth flag specifies whether a luma transform block contains at least one transform coefficient levels not equal to 0.

Abstract: A method related to adaptive usage of pixel-based and block-based affine motion compensation and includes performing sub-block-based affine transform prediction on an affine block with a first sub-block size if the first sub-block size is greater than or equal to a first sub-block size threshold. If the first sub-block size is less than the first sub-block size threshold, it is determined whether a pixel-based motion vector field is not applied for performing motion compensation for the affine block. If the motion vector field is not applied, a sub-block-based affine motion prediction is performed with a second sub-block size that is based on the first sub-block size. If the pixel-based motion vector field is applied, motion compensation is performed for a sub-block of the affine block using the pixel-based motion vector field.

Abstract: Apparatuses and methods for Intra Sub-Partitions (ISP) are provided. The method includes: obtaining information of ISP, and determining a size of a chroma transform block (TB) of the coding unit based on SubWidthC and SubHeightC when at least a first condition is fulfilled. The first condition includes the information of ISP indicates that ISP is used for splitting the luma coding block. SubWidthC and SubHeightC are variables depending on chroma format information. The chroma format information indicates a chroma format of a picture the coding unit belongs to. The method can apply to all chroma format. The chroma format includes at least one of: 4:2:0, or 4:2:2, or 4:4:4. An accurate and versatile way to determine the size of the chroma transform block for the ISP is achieved.

Abstract: An apparatus for inter prediction of a sample value of a current full-integer pixel of a plurality of pixels associated with a current block of a current frame of a video signal is disclosed. The apparatus is configured to: determine a motion vector of the current full-integer pixel based on a motion compensation model; determine for the current full-integer pixel a corresponding sub-integer pixel in a reference frame; determine positions of a set of corresponding filter support pixels in the reference frame; obtain a respective sample value of the corresponding sub-integer pixel of the current full-integer pixel and the corresponding filter support pixels in the reference frame by applying a bilinear interpolation; and determine the inter predicted sample value of the current full-integer pixel.

Abstract: The present disclosure provides a method of coding implemented by a decoding/encoding device for coding video data. The method comprises the following steps: for a block coded in affine mode, determining control point motion vectors, CPMVs; determining a reference area in a reference picture corresponding to a sub-block of the affine coded block based on the determined CPMVs; setting a variable clipMVX equal to TRUE if a size of the reference area is greater than a predefined threshold, otherwise setting a variable clipMVX equal to FALSE; deriving a pixel-based motion vector field for the affine coded block; wherein, if the variable clipMVX is equal to TRUE, the deriving the pixel-based motion vector field further comprises motion vector clipping based on a first clipping range, wherein the first clipping range is determined based on the determined CPMVs and a size of the affine coded block.

Abstract: A method for inverse quantization of a current block of a picture, the method comprising: receiving a bitstream; obtaining a joint chrominance component residual, JCCR, control flag from the bitstream; obtaining a chrominance mapping information from the bitstream based on the JCCR control flag; obtaining at least one chrominance quantization parameter, QP, offset from the bitstream based on the JCCR control flag; obtaining a QP value for the current chrominance block based on the obtained chrominance mapping information and the at least one obtained chrominance QP offset; performing inverse quantization on the current chrominance block by using the obtained QP value.

Abstract: A method for inverse quantization of a current block of a picture or a frame, where the method is performed by a decoder, and includes obtaining, by a decoder, from a bitstream, a joint chrominance residual (JCCR) mode for a current block of a picture or a frame, obtaining one or more quantization parameter (QP) offset values for chrominance components from the bitstream, determining at least one QP value for the current block depending on the JCCR mode, and performing an inverse quantization process on a chrominance component of the current block using the determined QP value.

Abstract: The present disclosure relates to methods and apparatuses for encoding video data into a bitstream and for decoding video data received in a bitstream. A second control flag indicating whether or not to use multi-hypothesis prediction for intra and inter mode is generated and transmitted only conditionally, upon a determination whether or not separate merge list technique for subblock merge candidates is used. On the other hand, a decoder is capable of deciding usage of multi-hypothesis prediction for intra and inter mode and separate merge list technique for subblock merge candidates even though the second control flag is transmitted only conditionally.

Abstract: A method of coding implemented by a decoding device or encoding device, the method comprising obtaining a bitstream, the bitstream comprises a transform unit syntax; the syntax comprises at least two cbf flags for chroma blocks (in an example, transform unit syntax correspond to either transform unit or sub-transform units which include two chroma cbf flags: tu_cbf_cb and tu_cbf_cb—one flag for each chroma plane), a chroma cbf flag specifies whether certain block has residue in correspondent color plane; deriving a value of a luma cbf flag tu_cbf_luma based on one or any combination of a value of a cu_cbf flag, values of two chroma cbf flags corresponding to a current transform unit or sub-transform unit, location of the sub-transform unit within transform unit, values of luma and chroma cbf flags correspondent to previous sub-transform units in the current transform unit.

Abstract: A filter is configured for processing a reconstructed frame for generation of a filtered reconstructed frame, and wherein the reconstructed frame comprises a plurality of pixels. The filter includes one or more processor configured to scan a current pixel of the reconstructed block and its neighboring pixels of the current pixel according to a predefined scan template, obtain spectrum components by performing transform for the current pixel and its neighboring pixels, obtain filtered spectrum components based on a filtering parameter and the spectrum components, obtain filtered pixels by performing inverse transform for the filtered spectrum components, and generate a filtered reconstructed block based on the filtered pixels.

Abstract: A method for coding a video implemented in an encoder or a decoder, comprising: determining control point motion vectors, CPMVs, for a block according to affine inter-prediction, according to a preselected affine motion model, the block being an affine block; performing motion compensation for the block using a pixel-based motion vector field according to values of the CPMVs, upon fulfilling at least one of the following conditions: A) for a predefined size of a sub-block of M×M, during processing of one line, respectively, of the sub-block the number of lines of the reference picture is less than N, where N is an integer and N is larger than 2.

Abstract: A method for coding a video implemented in an encoder or a decoder including the enhanced interpolation filter, EIF, for motion compensation, the method comprising: i) determining control point motion vectors, CPMVs, for a block according to affine inter-prediction, the block being an affine block or a sub-block of the affine block; ii) for a predefined sub-block size determining a reference area for a sub-block with the predefined sub-block size according to values of the CPMVs; iii) comparing the determined reference area with a predefined threshold; iv) applying EIF for motion compensation, comprising deriving the pixel-based motion vector field for the block; wherein if the determined reference area is larger than the threshold, deriving the pixel-based motion vector field for the block further comprises motion vector clipping, wherein motion vector clipping range is determined based on motion model of the block and the size of the block.

Abstract: A decoder for decoding a block of a current frame of a video from a bitstream and a corresponding encoder are provided. The decoder comprises a reference sample selection unit configured to select reference samples of a reconstructed part of the current frame, a filter unit configured to filter the reference samples, and a block generation unit configured to generate a prediction of the block based on the filtered reference samples, wherein the filter unit comprises a sharpening filter and/or a de-ringing filter.

Abstract: A method for deriving motion information for a current block includes: determining whether the current block and a top neighboring block of the current block are in a same coding tree unit (CTU) or not; obtaining a position of a spatial motion information candidate for the current block; obtaining motion information corresponding to the position of the spatial motion information candidate, depending on the result of whether the current block and top neighboring block of the current block are in the same CTU; adding the obtained motion information to a motion information candidate list for the current block; obtaining a value of a first index of a motion information candidate; and deriving motion information of the current block based on the motion information candidate list and the value of the first index.

Abstract: A filter, to an encoder and a decoder using the filter, to a filtering method and a corresponding program, as well as to encoding and decoding using the filtering method or the filter. The method includes obtaining of an extended reconstructed block by extending the current reconstructed block to include at least padding samples from the current reconstructed block. After padding, a current pixel of the extended reconstructed block and its neighboring pixels are loaded into a linear buffer and transformed with a one-dimensional (1D) transform. The method is performed in frequency domain using a look-up table and the filtered pixels are transformed back.

Abstract: A method for in-loop filtering by performing adaptive loop filtering on a reconstructed frame of a video stream, implemented by an encoding device or a decoding device, the method comprising forming differences between a pixel of the reconstructed frame and neighboring pixels in a connected area of the pixel, clipping the differences according to respective clipping levels, forming a weighted sum of the clipped differences, and adding the weighted sum to the pixel to determine a filtered pixel, wherein the respective clipping levels are chosen from a same set of clipping levels for the luma and chroma components.

Abstract: A method of obtaining quantization parameter (QP) for chrominance components based on QP for luminance component, wherein the method is performed by a decoder or encoder, and wherein the method comprises obtaining a luminance QP for a luma component of a coding unit; obtaining a QP index (QPi) based at least in a part on the luminance QP; and obtaining a chrominance QP (QPc) for a chroma component of the coding unit based on the QP index by using a preset lookup table, wherein the maximum difference between the QP index and the chrominance QP is equal to 3.

Abstract: A method of obtaining a chrominance quantization parameter (QP) for chrominance components based on a luminance QP for a luminance component, wherein the method is performed by a decoder, and comprises parsing a received bitstream to obtain the luminance QP and information of a mapping function (ƒ) which associates a QP index (QPi) to a chrominance QP (QPc); obtaining the QPi based at least in part on the luminance QP; obtaining the mapping function based on the obtained information of the mapping function; and obtaining a QPc based on the obtained mapping function and the obtained QPi.

Abstract: A method of obtaining a chrominance quantization parameter (QP) for chrominance components based on a luminance QP for luminance component, wherein the method is performed by a decoder, comprising parsing a received bitstream to obtain the luminance QP and information of a mapping function (ƒ) which associates a QP index (QPi) to the chrominance QP (QPc); obtaining the QPi based at least in a part on the luminance QP; obtaining the mapping function based on the obtained information; and obtaining a QPc based on the obtained mapping function and the obtained QPi.

Abstract: The disclosure relates to an in-loop filter apparatus for video coding, which is configured for processing a reconstructed frame corresponding to a current frame for generation of a filtered reconstructed frame, wherein the reconstructed frame comprises a plurality of pixels, each pixel being associated with a pixel value.