Abstract: A method for controlling bit-width for bi-directional optical flow (BDOF) for video coding includes acquiring, for a current picture, a first reference picture and a second reference picture, the second reference picture being different than the first reference picture, where the first reference picture is displayed before the current picture and the second reference picture is displayed after the current picture. A motion refinement of a coding unit (CU) is calculated by minimizing a difference between a first prediction L0 and a second prediction L1. First gradient values for the first prediction L0 and second gradient values for the second prediction L1 are calculated. A final bi-prediction of the CU is calculated. Also disclosed are an associated apparatus and an associated non-transitory computer readable storage medium.

Abstract: An electronic apparatus performs a method of decoding video data. The method comprises: receiving, from the video signal, a picture frame that includes a first component and a second component; determining a classifier for the second component from a set of samples of the first component associated with a respective sample of the second component; when the set of samples of the first component associated with the respective sample of the second component is divided by a virtual boundary, copying one or more central subsets of the set of samples of the first component to a first boundary position and a second boundary position of the set of samples of the first component; determining a sample offset for the respective sample of the second component according to the classifier; and modifying the value of the respective sample of the second component based on the determined sample offset.

Abstract: The present disclosure relates to a method for deriving constructed affine merge candidates. The method includes acquiring one or more control point sets from a decoder. The decoder determines whether a reference index of each control point for the control point set index within the control point set associated with a reference index pointing into a reference picture in a first reference picture list is greater than or equal to zero and each is equal to each other. The decoder also determines whether a reference index of each control point for the control point set index within the control point set associated with a reference index pointing into a reference picture in a second reference picture list is greater than or equal to zero and each is equal to each other. The decoder determines that an affine motion model is available based on the determination result.

Abstract: The present disclosure relates to a method for deriving constructed affine merge candidates. The method includes acquiring one or more control point sets from a decoder. The decoder determines whether a reference index of each control point for the control point set index within the control point set associated with a reference index pointing into a reference picture in a first reference picture list is greater than or equal to zero and each is equal to each other. The decoder also determines whether a reference index of each control point for the control point set index within the control point set associated with a reference index pointing into a reference picture in a second reference picture list is greater than or equal to zero and each is equal to each other. The decoder determines that an affine motion model is available based on the determination result.

Abstract: Methods, apparatuses, and non-transitory computer-readable storage mediums are provided for encoding video. An encoder may obtain a first motion vector (MV) associated with a video block obtained from the video. The encoder may obtain a first prediction signal of the video block using the first MV. The encoder may identify a target MV by applying a gradient-based motion refinement algorithm in a recursive manner using the first prediction signal and the first MV. The encoder may obtain a second prediction signal of the video block based on the target MV.

Abstract: A method and an apparatus for hybrid training of neural networks for video coding are provided. The method includes: obtaining, in an offline training stage, an offline trained network by training a first neural network offline using a plurality of first data sets; refining, in an online training stage, a plurality of neural network layers using a plurality of second data sets, wherein the plurality of neural network layers comprise at least one neural network layer in the offline trained network or in a second neural network connected to the offline trained network.

Abstract: A computing device performs a method of decoding video data by reconstructing a luma block corresponding to a chroma block; searching a sub-group of a plurality of reconstructed neighboring luma samples in a predefined order to identify a maximum luma sample and a minimum luma sample; computing a down-sampled maximum luma sample corresponding to the maximum luma sample; computing a down-sampled minimum luma sample corresponding to the minimum luma sample; generating a linear model using the down-sampled maximum luma sample, the down-sampled minimum luma sample, the first reconstructed chroma sample, and the second reconstructed chroma sample; computing down-sampled luma samples from luma samples of the reconstructed luma block, wherein each down-sampled luma sample corresponds to a chroma sample of the chroma block; and predicting chroma samples of the chroma block by applying the liner model to the corresponding down-sampled luma samples.

Abstract: An electronic apparatus performs a method of decoding video data. The method comprises: receiving, from the video signal, a picture frame that includes a first component and a second component; receiving, from the video signal, a first syntax element that indicates whether Cross-component Sample Adaptive Offset (CCSAO) is enabled for the second component at a picture level; when the first syntax element indicates the CCSAO is enabled for the second component at the picture level, receiving, from the video signal, a second syntax element that indicates whether the CCSAO is controlled for the second component at a coding tree block (CTB) level; and when the second syntax element indicates the CCSAO is controlled for the second component at the CTB level, receiving, from the video signal, a third syntax element that indicates whether the CCSAO is enabled for the second component at the CTB level.

Abstract: A method of constructing a uni-directional motion vector merge list for triangular shape processing units (PUs) in the triangle prediction mode of video coding standards, such as the current Versatile Video Coding (VVC), is performed at a computing device. The computing device constructs the motion vector merge list for the coding unit (CU) containing the triangular shape PUs, and then constructs the uni-directional motion vector merge list for the triangular shape PUs based on the motion vector merge list for the CU.

Abstract: A method, apparatus, and a non-transitory computer-readable storage medium for decoding a video signal are provided. A decoder may receive, through a bitstream, arranged syntax elements in sequence parameter set (SPS) level. The arranged syntax elements in the SPS level are arranged so that functions of related syntax elements are grouped in versatile video coding (VVC) syntax at a coding level. The decoder may receive, through the bitstream and in response to multiple syntax elements satisfy a predefined condition, a second syntax element immediately after the multiple syntax elements. The decoder may perform, through the bitstream, a related syntax element function to video data from the bitstream in accordance with the multiple syntax elements and the second syntax element.

Abstract: An electronic apparatus performs a method of decoding video data. The method includes receiving, from the video signal, a picture frame that includes a first component and a second component, receiving, from the video signal, a plurality of sample offsets associated with the second component, reconstructing the samples of the first component before a first in-loop filter module, reconstructing the samples of the second component after a second in-loop filter module, determining a classifier for the second component from one or more reconstructed samples of the first component relative to each sample of the second component, selecting a sample offset from the plurality of sample offsets for the second component according to the classifier, and modifying the reconstructed samples of the second component based on the selected sample offset.

Abstract: Methods and devices are provided for rectifying a forward mapping coding bit length issue introduced by LMCS. In one method, a plurality of prediction samples, in a mapped domain, of luma component of a CU that is coded by a CIIP mode under LMCS framework is obtained, a plurality of residual samples, in the mapped domain, of the luma component of the CU is obtained, the plurality of prediction samples in the mapped domain is added to the plurality of residual samples in the mapped domain, resulting in a plurality of reconstructed samples, in the mapped domain, of the luma component, and the plurality of reconstructed samples of the luma component is converted from the mapped domain into an original domain based on a pre-defined plurality of inverse mapping scaling factors.

Abstract: A computing device performs a method of decoding video data by reconstructing a luma block corresponding to a chroma block; searching a sub-group of a plurality of reconstructed neighboring luma samples in a predefined order to identify a maximum luma sample and a minimum luma sample; computing a down-sampled maximum luma sample corresponding to the maximum luma sample; computing a down-sampled minimum luma sample corresponding to the minimum luma sample; generating a linear model using the down-sampled maximum luma sample, the down-sampled minimum luma sample, the first reconstructed chroma sample, and the second reconstructed chroma sample; computing down-sampled luma samples from luma samples of the reconstructed luma block, wherein each down-sampled luma sample corresponds to a chroma sample of the chroma block; and predicting chroma samples of the chroma block by applying the liner model to the corresponding down-sampled luma samples.

Abstract: Methods and apparatuses for video coding are provided. The method includes that a decoder receives a first syntax element in picture parameter sets(PPS) specifying whether a picture corresponding to the PPS comprises one or more network abstraction layer (NAL) units and whether the one or more NAL units have a same NAL unit type, receives a second syntax element in a picture header (PH) specifying whether the picture corresponding to the PH is an intra random access point (IRAP) picture or a gradual intra refreshing (GDR) picture, and determines a value of the first syntax element based on a value of the second syntax element or determines the value of the second syntax element based on the value of the first syntax element.

Abstract: Methods, apparatuses, and non-transitory computer-readable storage mediums are provided for decoding a video block in geometry partition mode (GPM). The method may include partitioning the video block into first and second geometric partitions. The method may include obtaining a first motion vector refinement (MVR) for the first geometric partition. The method may include obtaining a second MVR for the second geometric partition. The method may include obtaining a candidate list that comprises a plurality of motion vectors (MVs). The method may include obtaining a first MV from the candidate list for the first geometric partition. The method may include obtaining a second MV from the candidate list for the second geometric partition. The method may include calculating a third MV by adding the first MV with the first MVR for the first geometric partition. The method may include calculating a fourth MV. The method may include obtaining prediction samples.

Abstract: An electronic apparatus performs a method of coding video data. The method comprises: receiving, from the bitstream, syntax elements associated with a coding unit, wherein the syntax elements include a first coded block flag (CBF) for residual samples of a first chroma component, a second CBF for residual samples of a second chroma component, and a third syntax element indicating whether adaptive color transform (ACT) is applied to the coding unit; determining whether to perform the chroma residual scaling to the residual samples of the chroma components according to the first CBF, the second CBF, and the third syntax element; in accordance with a determination to perform the chroma residual scaling to the residual samples of the first and second chroma components, scaling the residual samples of the at least one of the first and second chroma components based on a corresponding scaling parameter.

Abstract: Methods, devices, and storage mediums are provided for decoding video signals. A decoder receives at least one versatile video coding (VVC) syntax flag. The decoder receives, in response to a syntax element indicating that inter prediction is allowed, inter related syntax elements. The decoder obtains a first reference picture I(0) and a second reference picture I(1) associated with a video block in a bitstream. The decoder obtains first prediction samples I(0)(i,j) of the video block from a reference block in the first reference picture I(0). The decoder obtains second prediction samples I(1)(i,j) of the video block from a reference block in the second reference picture I(1). The decoder obtains bi-prediction samples based on the at least one VVC syntax flag, the inter related syntax elements, the first prediction samples I(0)(i,j), and the second prediction samples I(1)(i,j).

Abstract: A method for video coding is provided. The method includes: partitioning video pictures into a plurality of coding units (CUs), at least one of which is further portioned into two prediction units (PUs) including at least one triangular shaped PU with a partitioning orientation in one of: from top-left corner to bottom-right corner, and from top-right corner to bottom-left corner; constructing a uni-prediction motion vector candidate list; determining whether a current CU is coded as triangle prediction mode according to coded information; signaling a partition orientation flag indicating the partitioning orientation; and signaling index values that indicate selected entries in the constructed uni-prediction motion vector candidate list.

Abstract: A method for video coding is provided. The method includes: partitioning video pictures into a plurality of coding units (CUs), at least one of which is further portioned into two prediction units (PUs) including at least one triangular shaped PU with a partitioning orientation in one of: from top-left corner to bottom-right corner, and from top-right corner to bottom-left corner; constructing a uni-prediction motion vector candidate list; determining whether a current CU is coded as triangle prediction mode according to coded information; signaling a partition orientation flag indicating the partitioning orientation; and signaling index values that indicate selected entries in the constructed uni-prediction motion vector candidate list.

Abstract: A computing device performs a method of decoding video data by acquiring a video bitstream including data associated with multiple encoded pictures, each picture including multiple rows of coding tree units (CTUs) and each CTU including one or more coding units (CUs). A data buffer storing a plurality of history-based motion vector predictors is used for encoding the rows of CTUs and the decoding process resets the buffer before decoding a first CU of a current row of CTUs. For a current CU of the row of CTUs, a motion vector candidate list is constructed from exploiting spatial and temporal correlation of motion vectors of neighbouring code units as well as the history-based motion vector predictors in the buffer. Finally, one motion vector predictor is selected, from the motion vector candidate list, for decoding the current CU and the buffer is updated based on the selected one.