Abstract: The present disclosure relates to intra- or inter-prediction for video encoding and decoding. For that purpose, an apparatus and methods obtain a reference sample and a subpixel offset value. A 4-tap interpolation filter is used to filter the reference sample to obtain a predicted sample value. The filter coefficients c0, c1, c2, and c3 of the 4-tap interpolation filter satisfy subpixel offset.

Abstract: A method for picture or video encoding, wherein a block of residual signal is being subsampled before transform, quantization and residual coding, comprising obtaining a residual signal from an original picture and a predicted block; obtaining a subsampled block from samples of a near-boundary region of a block of residual signal, wherein the subsampled block has a smaller size than the block of residual signal; performing forward transform over the subsampled block; performing quantization over the subsampled block to obtain a subsampled quantized residual block; performing residual coding of the subsampled quantized residual block; obtaining a subsampled reconstructed residual block by inverse quantization and inverse transform of the subsampled quantized residual block; obtaining a reconstructed residual block by filling samples of the near-boundary region of the reconstructed residual block from the subsampled reconstructed residual block; and obtaining a reconstructed block from the predicted block and t

Abstract: A block vector predictor (BVP) may be adjusted to provide a more accurate prediction of a block vector (BV). A reference region may be determined corresponding to a direction for flipping, for example, based on a reconstruction-reordered intra block copy (RRIBC) mode being indicated in a direction for flipping a reference block relative to a current block. The reference region corresponding to the flipping direction may be used with respect to a BVP to determine whether the BVP should be replaced with an adjusted BVP.

Abstract: Encoding and/or decoding a block of a video frame may be based on a previously decoded reference block in the same frame or in a different frame. The reference block may be indicated by a block vector (BV). The BV may be encoded as difference (e.g., block vector difference (BVD)) between a block vector predictor (BVP) and the BV. The BVP may indicate a codeword comprising a prefix part and a suffix part. Efficient entropy coding may be achieved by selectively using variable length coding for the prefix part and the suffix part. For example, variable length coding for the prefix part and the suffix part may be used if the prefix part indicates a maximum prefix value.

Abstract: A video parameter (e.g., a block vector difference (BVD)) may be represented as a codeword encoded using an entropy code. The codeword may comprising a prefix part and a suffix part. A prefix part may indicate a range of values, and a suffix part may indicate a specific value within the range. Efficient entropy coding may be achieved by reducing lengths of suffix parts associated with one or more selected prefix parts. The prefix parts may be selected based on a maximum possible value of the video parameter.

Abstract: A method of video coding, wherein the method comprises inter-prediction processing of a first block, wherein the inter-prediction processing comprises subpixel interpolation filtering of samples of a reference block; intra-prediction processing of a second block, wherein the intra-prediction processing comprises subpixel interpolation filtering of reference samples; wherein the method further comprises selecting interpolation filter coefficients for the subpixel interpolation filtering based on a subpixel offset between integer reference sample positions and fractional reference samples' positions, wherein for the same subpixel offsets the same interpolation filter coefficients are selected for intra-prediction processing and inter-prediction processing.

Abstract: A method of an inter prediction process performed by a processing unit of a coding system comprises deriving combined linear combination parameters from two sets of linear combination parameters, where a first set of linear combination parameters is independent from the position of the to-be-predicted block and a second set of linear combination parameters depends on the position of the to-be-predicted block; and obtaining the value of the to-be-predicted sample using the combined linear combination parameters and predicted values of at least two samples belonging to different reference blocks of the to-be-predicted block.

Abstract: Provided are a method, an apparatus, a computer program product and a non-transitory computer-readable medium for video coding. The method comprises performing an intra-prediction process of a block comprising samples to be predicted, wherein an interpolation filter is applied to reference samples of the block during the intra-prediction process of the block. The interpolation filter is selected on the basis of a subpixel offset between the reference samples and the samples to be predicted, and a size of a main reference side used in the intra-prediction process is determined according to a length of the interpolation filter and an intra-prediction mode that provides, out of a 10 set of available intra-prediction modes, the greatest non-integer value of said subpixel offset, wherein the main reference side comprises the reference samples.

Abstract: Devices and methods of directional intra prediction for chroma component of a picture are provided. The method includes obtaining an initial intra prediction mode of the chroma component, and deriving a chroma intra prediction mode (intraPredModeC) from a look up table (LUT) by using the initial intra prediction mode of the chroma component. The chroma component has different subsampling ratios in horizontal and vertical directions. The method further includes performing wide-angle mapping on the chroma intra prediction mode (intraPredModeC) to obtain a modified intraPredModeC; obtaining an angle parameter for the chroma component based on the modified intraPredModeC; and obtaining predicted samples of the chroma component based on the angle parameter. The method provides the minimum number of entries in the LUT that is used to determine chroma intra prediction mode from the initial chroma intra prediction mode.

Abstract: Encoding and/or decoding a block of a video frame may be based on a previously decoded reference block in the same frame or a different frame. The reference block may be indicated by a block vector (BV). A block vector difference (BVD) predictor may be used to make predictions about the symbols of one or more magnitude components of a BVD. A quantity of symbols used for BVD magnitude prediction may be limited. The limited quantity of symbols used for prediction may be allocated to one or more of the magnitude components. Allocation of the symbols used for BVD magnitude prediction may be based on the total quantity of symbols used for BVD magnitude prediction and the respective quantities of symbols available for prediction of each of the magnitude components. Symbols of a motion vector difference (MVD) likewise may be predicted.

Abstract: The present disclosure relates to apparatuses and methods for intra- or inter-prediction for video encoding and decoding. In one embodiment, a method includes obtaining a reference sample and obtain a fractional sample position p; filtering the reference sample using a subpixel interpolation filter to obtain a predicted sample value. In the method, the filter coefficients of the subpixel interpolation filter satisfy a linear combination of p and a filter strength parameter S.

Abstract: Encoding and/or decoding a block of a video frame may be based on a previously decoded reference block in the same frame or a different frame. The reference block may be indicated by a block vector (BV). A block vector difference (BVD) predictor may be used to make predictions about whether the sign of a BVD is positive or negative. The sign of a BVD may be predicted based on a range of values for a magnitude of the BVD and independent of a precise value for the magnitude of the BVD. A motion vector difference (MVD) predictor may be used to make predictions about the sign of an MVD. The MVD may be used with a motion vector predictor (MVP) to indicate a motion vector (MV).

Abstract: Apparatuses and methods for encoding and decoding are provided. The method for intra predicting a chroma sample of a block by applying cross-component linear model includes: obtaining reconstructed luma samples; determining maximum and minimum luma sample values based on the reconstructed luma samples; obtaining a difference of the maximum and minimum luma sample values. The method also includes: fetching a value out of a lookup table (LUT) by using a set of bits as an index, the set of bits following a position of the most-significant bit; obtaining linear model parameters based on the fetched value; and calculating a predicted chroma sample value by using the obtained linear model parameters. The efficiency to fetch the value out of the LUT is increased.

Abstract: The present disclosure relates to a method and apparatus for motion vector derivation for affine based inter prediction of chroma subblocks based on a chroma format. The method includes: determining chroma scaling factors in horizontal and vertical directions based on chroma format information, wherein the chroma format information indicates a chroma format of a current picture which the current image block belongs to; determining a set of luma subblocks of the luma block based on values of the chroma scaling factors; and determining a motion vector for a chroma subblock of the co-located chroma block based on motion vectors of one or more luma subblocks in the set of luma subblocks.

Abstract: Encoding and/or decoding a block of a video frame may be based on a previously decoded reference block in the same frame or a different frame. The reference block may be indicated by a block vector (BV). A block vector difference (BVD) predictor may be used to make predictions about the magnitude of a BVD. The BVD predictor may be selected from BVD candidates, which may be pruned based on costs associated with them. Pruning the BVD candidates may improve additional predictions and thus improve the compression efficiency of the predictions. A motion vector difference (MVD) predictor may be used to make predictions about the magnitude of an MVD. The MVD may be used with a motion vector predictor (MVP) to indicate a motion vector (MV).

Abstract: A video coding device, comprising a sequence of filters that are configurable by one or more primary parameters and one or more secondary parameters, and a filter controller configured to adjust the one or more secondary parameters based on the one or more primary parameters and based on a strength criterion of the sequence of filters.

Abstract: Encoding and/or decoding a block of a video frame may be based on a previously decoded reference block in the same frame or a different frame. The reference block may be indicated by a block vector (BV). A block vector (BV) may be based on a block vector predictor (BVP) and a block vector difference (BVD). The BVD may be indicated based on a prediction about the magnitude of the BVD, which may improve the compression efficiency of one or more magnitude symbols of a BVD and reduce signaling overhead required for indicating the BVD. The disclosures described herein and used to indicate a BVD also may be used to indicate a motion vector difference (MVD).

Abstract: The present disclosure relates to intra- or inter-prediction for video encoding and decoding. For that purpose, an apparatus and methods obtain a reference sample and a subpixel offset value. A 4-tap interpolation filter is used to filter the reference sample to obtain a predicted sample value. The filter coefficients c0, c1, c2, and c3 of the 4-tap interpolation filter satisfy c 0 = 16 - p 2 , c 1 = 16 + 16 - p 2 , c 2 = 16 + p 2 , and ? ? c 3 = p 2 , with p being a fractional part of the value of the subpixel offset.

Abstract: Apparatuses and methods for intra predicting a block are described. The method of intra predicting a current block can include obtaining a predicted sample value from one or more reference sample values by using an intra prediction mode, obtaining at least one additional reference sample value in accordance with the intra prediction mode, and obtaining a thresholded additional reference sample value based on the additional reference sample value. The method can also include calculating an additional value from the thresholded additional reference sample value, multiplying the predicted sample value by a sample weighting factor, resulting in a weighted predicted sample value, adding the additional value to the weighted predicted sample value, resulting in a non-normalized predicted sample value, and normalizing the non-normalized predicted sample value, resulting in a normalized predicted sample values. The accuracy for the intra prediction is thus increased.

Abstract: Devices and methods of intra prediction of a block of a picture are provided. The method includes obtaining reference samples of a block, and determining a value of a predicted sample based on the reference samples and an intra prediction mode. The method further includes obtaining a value of a multiplier based on at least one dimension of the block, and normalizing the value of the predicted sample based on the value of the multiplier and a value of a shift. The intra prediction mode is INTRA_DC, or INTRA_BI, or horizontal intra prediction mode. By normalizing the value of the predicted sample based on the value of the multiplier and a value of a shift without division operation, the method could increase intra prediction efficiency.