Abstract: Embodiments of the disclosure provide systems and methods for applying neural network based sample adaptive offset (SAO) for video coding. The method may include classifying reconstructed samples of a reconstructed block into a set of categories based on neural network based in-loop filtering (NNLF). The reconstructed block includes a reconstructed version of a video block of a video frame from a video. The method may further include determining a set of offsets for the set of categories based on the classification of the reconstructed samples. The method may additionally include, responsive to the NNLF being performed on the reconstructed block, performing SAO filtering on the NNLF filtered samples based on the set of offsets. The NNLF filtered samples are generated from the reconstructed samples using the NNLF.

Abstract: This application is directed to decoding video data including a plurality of luma components of a plurality of pixels in a video frame. The plurality of pixels belong to a coding block, and include a boundary pixel that is inside the coding block wherein the boundary pixel is immediately adjacent to a boundary of the coding block. One or more neighboring pixels of the boundary pixel are outside of the coding block and determined as being not available. A respective luma component corresponding to the boundary pixel is assigned to a luma component corresponding to each of the one or more neighboring pixels. A boundary luma component is determined based, at least, on the luma components of the one or more neighboring pixels and the boundary pixel according to a predefined luma interpolation scheme. A boundary chroma component is converted from the boundary luma component according to a linear mapping model.

Abstract: This application is directed to coding video data including a plurality of transform blocks according to a transform skip mode. Two or more control flags are obtained with the video data to indicate signaling of a Rice parameter for the transform blocks on different hierarchical levels. In accordance with a determination that a first control flag is enabled on a first hierarchical level and a second control flag is enabled on a second hierarchical level lower than the first hierarchical level, entropy coding is performed for a subset of the transform blocks based on a Rice parameter obtained with the video data. In accordance with a determination that the first control flag is enabled and that the second control flag is disabled on the second hierarchical level, entropy coding is performed for the subset of the transform blocks based on a predetermined Rice parameter at the second hierarchical level.

Abstract: An electronic apparatus performs a method of decoding video data that includes: if the adaptive color transform (ACT) is enabled for the residuals of a coding unit, receiving, from information in a bitstream, the adjustment values applied to the quantization parameters for de-quantization, and the coefficients for the residuals of the coding unit; reconstructing the residuals of the coding unit by applying the de-quantization and inverse transform to the received coefficients for the residuals of the coding unit; and if the residuals of the coding unit have been coded using the ACT, modifying the reconstructed residuals of the coding unit by applying an inverse ACT to convert the reconstructed residuals of the coding unit from the YCgCo color space to the original color space based on one same inverse ACT matrix that is applied to the one coding unit being coded either in a lossy or lossless coding mode.

Abstract: A method and a computing device are provided for video coding. The method may include deriving parameter ? and parameter ? for a CCLM mode by using a predetermined number of neighboring reconstructed luma samples and chroma samples in a CU; and generating a final chroma predictor for the chroma samples of the CU by using the parameter a and the parameter ?.

Abstract: An electronic apparatus performs a method of encoding and decoding video data. The method comprises: receiving, from a bitstream, the video data corresponding to a coding unit; receiving, from the video data, a first syntax element that defines a Motion Estimation Region (MER); receiving a plurality of second syntax elements from the video data, wherein the plurality of second syntax elements indicate whether the coding unit is in a subblock-based temporal motion vector prediction (SbTMVP) mode; in accordance with a determination that the coding unit is in the SbTMVP mode, determining whether both a spatial neighboring block used to determine a temporal vector of the coding unit and the coding unit are within the same MER; and in accordance with a determination that both the spatial neighboring block and the coding unit are within the same MER, setting the temporal vector of the coding unit to zero.

Abstract: Cross plane filtering may be used for enhanced chroma coding. An indication of a cross-plane filter associated with a current picture may be received. The current picture may include an intra-coded video block and a plurality of reference samples. The plurality of reference samples may be used to predict the intra-coded video block. A luma sample region may be determined in the current picture. The luma sample region may determined to enhance a corresponding chroma sample in the current picture. The cross-plane filter may be applied to a plurality of luma samples in the luma sample region to determine an offset. The cross-plane filter may be a high pass filter. The offset may be applied to the corresponding chroma sample to determine an enhanced chroma sample.

Abstract: This application is directed to coding video data that includes a plurality of image samples of a video frame. Each image sample corresponds to one of a luma sample and a chroma sample. Each image sample is filtered using an adaptive in-loop filter having a filter length and a set of filter coefficients. A set of related image samples are identified in the filter length of each image sample. For each related image sample, a respective clip value index and a corresponding filter coefficient are identified. A difference of each related image sample and the respective image sample is clipped based on the respective clip value index that corresponds to a respective clipping boundary value equal to 2 to a power of a respective clipping number. The respective image sample is modified with the clipped difference of each of the related image samples based on the respective filter coefficient.

Abstract: Systems and methods are described for reducing the complexity of using bi-directional optical flow (BIO) in video coding. In some embodiments, bit-width reduction steps are introduced in the BIO motion refinement process to reduce the maximum bit-width used for BIO calculations. In some embodiments, simplified interpolation filters are used to generate predicted samples in an extended region around a current coding unit. In some embodiments, different interpolation filters are used for vertical versus horizontal interpolation. In some embodiments, BIO is disabled for coding units with small heights and/or for coding units that are predicted using a sub-block level inter prediction technique, such as advanced temporal motion vector prediction (ATMVP) or affine prediction.

Abstract: Systems and methods are described for selecting a motion vector (MV) to use in frame-rate up conversion (FRUC) coding of a block of video. In one embodiment, a first set of motion vector candidates is identified for FRUC prediction of the block. A search center is defined based on the first set of motion vector candidates, and a search window is determined, the search window having a selected width and being centered on the search center. A search for a selected MV is performed within the search window. In some embodiments, an initial set of MVs is processed with a clustering algorithm to generate a smaller number of MVs that are used as the first set. The selected MV may be subject to a motion refinement search, which may also be performed over a constrained search range. In additional embodiments, search iterations are constrained to limit complexity.

Abstract: This application is directed to processing video data that includes a plurality of luma samples and a plurality of chroma samples corresponding to a plurality of pixel groups of a video frame. For each pixel group, an electronic device identifies a respective chroma sample and a set of luma samples and determines an anchor luma sample from the set of luma samples. A chroma refinement value is generated based on the set of luma samples by differencing a respective luminance value of each luma sample in the set by an anchor luminance value of the anchor luma sample and applying a cross component filter to the difference luminance values of the set of luma samples. The electronic device then updates the chroma sample using the chroma refinement value for each pixel group and stores the updated respective chroma sample of each pixel group in association with the video frame.

Abstract: Systems and methods are described for video coding using generalized bi-prediction. In an exemplary embodiment, to code a current block of a video in a bitstream, a first reference block is selected from a first reference picture and a second reference block is selected from a second reference picture. Each reference block is associated with a weight, where the weight may be an arbitrary weight ranging, e.g., between 0 and 1. The current block is predicted using a weighted sum of the reference blocks. The weights may be selected from among a plurality of candidate weights. Candidate weights may be signaled in the bitstream or may be derived implicitly based on a template. Candidate weights may be pruned to avoid out-of-range or substantially duplicate candidate weights. Generalized bi-prediction may additionally be used in frame rate up conversion.

Abstract: An electronic apparatus performs a method of decoding video data, comprising: receiving, from bitstream, a first syntax element in a slice header of a slice that indicates whether luma mapping with chroma scaling (LMCS) is applied to a coding unit in the slice; receiving a second syntax element for the coding unit that indicates whether the coding unit has been coded using adaptive color-space transform (ACT); if the second syntax element has a non-zero value, decoding the coding unit by applying inverse ACT to convert luma and chroma residuals of the coding unit from a transformed color space to an original color space of the video data; and if the first syntax element has a non-zero value, decoding the coding unit by performing inverse luma mapping to the luma samples and inverse scaling to the chroma residuals of the coding unit after performing the inverse ACT.

Abstract: An electronic apparatus performs a method of encoding and decoding video data. The method comprises: decoding a first coding block and a second coding block that shares a common edge on a first picture, wherein decoding the first coding block and the second coding block includes reconstructing a first residual block for the first coding block and a second residual block for the second coding block; determining that the first picture has a first resolution, a first reference picture corresponding to the first coding block has a second resolution, and a second reference picture corresponding to the second coding block has a third resolution; deriving a deblocking strength (bS) value based, at least in part, on the first resolution, second resolution, and the third resolution; and performing in-loop filtering on the reconstructed first residual block and the reconstructed second residual block using a deblocking filter in accordance with the derived bS value.

Abstract: An electronic apparatus performs a method of encoding and decoding video data. The method comprises: receiving bitstream encoding a transform block, wherein the transform block includes a non-zero region and a zero-out region; checking whether there is any non-zero coefficient within the zero-out region; in accordance with a determination that there is no non-zero coefficient within the zero-out region of the transform block: determining a scan order index of a last non-zero coefficient of the transform block along a scanning direction; in accordance with a determination that the scan order index of the last non-zero coefficient is greater than a predefined threshold: receiving, from the bitstream, a value for multiple transform selection (MTS) index; and applying respective transforms to transform coefficients of the transform block in both horizontal and vertical directions based on the value of the MTS index.

Abstract: Cross plane filtering may be used for enhanced chroma coding. An indication of a cross-plane filter associated with a current picture may be received. The current picture may include an intra-coded video block and a plurality of reference samples. The plurality of reference samples may be used to predict the intra-coded video block. A luma sample region may be determined in the current picture. The luma sample region may determined to enhance a corresponding chroma sample in the current picture. The cross-plane filter may be applied to a plurality of luma samples in the luma sample region to determine an offset. The cross-plane filter may be a high pass filter. The offset may be applied to the corresponding chroma sample to determine an enhanced chroma sample.

Abstract: A method for video encoding is provided. The method includes: generating an inter prediction of a current coding block based on at least one motion vector from a current picture to at least one reference picture respectively; generating an intra prediction of the current coding block based on an intra prediction mode; generating a final prediction of the current coding block by weighted averaging the inter prediction and the intra prediction; determining the current coding block is treated as inter mode upon constructing a most probable mode (MPM) list of a neighboring coding block, or determining the current coding block is treated as intra mode upon constructing an MPM list of a neighboring coding block; and putting entropy-encoded information indicating that the current coding block is treated as inter mode or intra mode in a bitstream to be transmitted to a decoder.

Abstract: Systems, methods, and instrumentalities are described herein for calculating local illumination compensation (LIC) parameters for bi-predicted coding unit (CU). The LIC parameters may be used to generate adjusted samples for the current CU and to address local illumination changes that may exist among temporal neighboring pictures. LIC parameters may be calculated based on bi-predicted reference template samples and template samples for a current CU. Bi-predicted reference template samples may be generated based on reference template samples neighboring temporal reference CUs. For example, the bi-predicted reference template samples may be generated based on averaging the reference template samples. The reference template samples may correspond to template samples for the current CU. A CU may be or may include a coding block and/or a sub-block that may be derived by dividing the coding block.

Abstract: A method for video encoding is provided. The method includes: partitioning a frame of video data into a plurality of blocks; obtaining a current prediction of a current block of the plurality of blocks using one or more motion vectors of the current block; obtaining one or more collocated predictions of the current block using one or more motion vectors of one or more neighbor blocks of the current block in respective one or more blending areas, where each of the one or more blending areas is at least part of the current block and adjustable based at least on the partitioning; and obtaining a combined prediction of the current block by combing the current prediction with the one or more collocated predictions.

Abstract: External overlapped block motion compensation (OBMC) may be performed for samples of a coding unit (CU) located along an inter-CU boundary of the CU while internal OBMC may be performed separately for samples located along inter-sub-block boundaries inside the CU. External OBMC may be applied based on substantially similar motion information associated with multiple external blocks neighboring the CU. The external blocks may be treated as a group to provide OBMC for multiple boundary samples together in an external OBMC operation. Internal OBMC may be applied using the same sub-block size used for sub-block level motion derivation. Internal OBMC may be disabled for the CU, for example, if the CU is coded in a spatial-temporal motion vector prediction (STMVP) mode.