Abstract: Devices, systems and methods for sub-block based prediction are described. In a representative aspect, a method for video processing includes partitioning a first component of a current video block into a first set of sub-blocks and partitioning a second component of the current video block into a second set of sub-blocks. A sub-block of the second component corresponds to one or more sub-blocks of the first component. The method also includes deriving, based on a color format of the current video block, motion vectors for a sub-block of the second component based on motion vectors for one or more corresponding sub-blocks of the first color component.

Abstract: A method of decoding JVET video, comprising defining a coding unit (CU) template within a decoded area of a video frame, the CU template being positioned above and/or to the left of a current decoding position for which data was intra predicted, defining a search window within the decoded area, the search window being adjacent to the CU template, generating a plurality of candidate prediction templates based on pixel values in the search window, each of the plurality of candidate prediction templates being generated using different intra prediction modes, calculating a matching cost between the CU template and each of the plurality of candidate prediction templates, selecting an intra prediction mode that generated the candidate prediction template that had the lowest matching cost relative to the CU template, and generating a prediction CU for the current decoding position based on the intra prediction mode.

Abstract: The present invention relates to a technique for encoding and decoding video data, and more particularly, to a method for performing inter-prediction in an effective manner. The present invention combines an inter-prediction method using an AMVP mode and an inter-prediction method using a merge mode so as to propose a method for using the same candidate. The method for encoding video data proposed by the present invention comprises the following steps: receiving mode information on an inter-prediction method of a current block; determining, on the basis of the received mode information, whether the interprediction method to be applied to the current block is an AMVP mode or a merge mode; and selecting a candidate to derive motion information of the current block, wherein the candidate is selected in a left region, top region and corner region of the current block and in the same position block as the current block, and the AMVP mode and the merge mode are applied on the basis of the selected candidate.

Abstract: An image processing apparatus including a memory and a processor is provided. The image processing apparatus is configured to perform selecting one of data compression processing modes in response to a user input, and executing, according to the selected data compression processing mode, data compression processing on an input captured image based on an inter-frame prediction. The image processing apparatus is further configured perform generating a compressed image from the executed data compression processing. A group of pictures with respect to the generated compressed image is different according to the data compression processing modes. When receiving a request for acquiring vital information from a person captured in the input captured image, one of the data compression processing modes is selected so that the generated compressed image is configured by I pictures only.

Abstract: In a moving image decoding device for decoding encoded data of a tile group splitting a picture into one or more rectangular regions and consisting of one or more segments, a WPP enabled flag for indicating whether a segment in an object tile group is a CTU row having a height of one CTU is decoded, and when the WPP enabled flag is 1, after a CTU at a right end of the CTU row is decoded, an end bit of a first segment having a fixed value is decoded.

Abstract: An image decoding method performed by a decoding device according to the present disclosure comprises: a step of deriving reference picture list 0 (L0) and reference picture list 1 (L1); a step of deriving two motion vectors (MV) for a current block, the two MVs including MVL0 for the L0 and MVL1 for the L1; a step of determining whether to apply bi-prediction optical flow (BIO) prediction for deriving refined motion vectors by sub-blocks to the current block; a step of deriving a refined motion vector for a sub-block of the current block based on the MVL0 and MVL1, if the BIO prediction is applied to the current block; and a step of deriving a prediction sample based on the refined motion vector.

Abstract: A method of dividing an input image signal into pixel blocks, and performing inter-prediction on the divided pixel blocks. This method includes selecting predicted motion information from a motion information buffer storing motion information in an encoded region, and predicting motion information of an encoding target block by using the predicted motion information. The method further includes acquiring representative motion information from a plurality of items of motion information in an encoded region in accordance with first information indicating a method of selecting the predicted motion information, thereby obtaining only the representative motion information.

Abstract: An intra predictor (181) for performing intra prediction on each of blocks obtained by dividing an original image in the form of a frame, the intra predictor (181) includes; a linear model calculator (1811a) configured to calculate a linear model of the luminance component and the chroma component of the target block using decoded pixel values of the luminance component and decoded pixel values of the chroma component around the target block on which the intra prediction is performed; a chroma component predictor (1811b) configured to predict pixel values of the chroma component of the target block by applying the linear model calculated by the linear model calculator (1811a) to decoded pixel values of a luminance component of the target block; and a chroma component corrector (1812) configured to correct predicted pixel values of the chroma component obtained by the chroma component predictor (1811b) using decoded pixel values that were not used to calculate a linear model by the linear model calculator (181

Abstract: According to the present invention, provided is a method of processing a video signal, the method including: obtaining a transform coefficient of a current block from a bitstream according to a predetermined scanning order; determining an intra prediction mode of the current block on the basis of the transform coefficient; and performing intra prediction on the current block using the intra prediction mode and a neighboring sample adjacent to the current block.

Abstract: A video processing method includes determining, for a conversion between a block of a video and a bitstream representation of the video, that a secondary transform with a reduced dimension dimension (e.g., an inverse low frequency non-separable transform) is applicable to a single sub-block of the block in case a dimension of the block satisfies a condition. The secondary transform is performed between a forward primary transform and a quantization step or between a de-quantization step and an inverse primary transform. The reduced dimension is reduced from a dimension of the block. The method also includes performing the conversion based on the determining.

Abstract: Particular embodiments provide a variable, BitDepth, that may be set at a value based on a number of bits used to represent pixels in pictures of a video. The variable may be used in syntax elements in HEVC, such as the HEVC range extension, but other coding standards may be used. By using the variable, different resolutions for the video may be accommodated during the encoding and decoding process. For example, the number of pixels in the pictures may be represented by 8 bits, 10 bits, 12 bits, or another number of bits depending on the resolution. Using the BitDepth variable in the syntax provides flexibility in the motion estimation and motion compensation process. For example, syntax elements used in the weighted prediction process may take into account different numbers of bits used to represent the pictures.

Abstract: A method for video processing is provided. The method includes determining, for a conversion between a current video block of a video that is a chroma block and a coded representation of the video, multiple sets of parameters, wherein each set of parameters defines a cross-component linear model (CCLM) and is derived from a corresponding group of chroma samples at corresponding chroma sample positions; determining, based on the multiple sets of parameters, parameters for a final CCLM; and performing the conversion based on the final CCLM.

Abstract: A video encoder and video decoder may be configured to disable subpicture processing in situations where reference picture scaling is enabled. In another example, when reference picture scaling is enabled, a video encoder may determine a reference picture scaling ratio for the reference picture resampling process based on a width of a scaling window (PicOutputWidthL) of the current picture and a height of the scaling window (PicOutputHeightL) of the current picture. The values of PicOutputWidthL and PicOutputHeightL are constrained, respectively, relative to a width of a scaling window (refPicOutputWidthL) of the reference picture and a height of the scaling window (refPicOutputHeightL) of the reference picture.

Abstract: An image decoding method according to the present disclosure includes deriving a history-based motion vector prediction (HMVP) buffer for a current block, deriving motion information of the current block based on an HMVP candidate included in the HMVP buffer, generating prediction samples for the current block based on the motion information, and generating reconstructed samples based on the prediction samples, and the HMVP buffer is initialized when processing a first-ordered CTU in a CTU row in which a current CTU is located, and the current block is included in the current CTU.

Abstract: Devices, systems and methods for digital video coding, which include sub-block based inter prediction methods, are described. An exemplary method for video processing includes determining, for a conversion between a current block of video and a bitstream representation of the video, a maximum number of candidates in a sub-block based merge candidate list and/or whether to add sub-block based temporal motion vector prediction (SbTMVP) candidates to the sub-block based merge candidate list based on whether temporal motion vector prediction (TMVP) is enabled for use during the conversion or whether a current picture referencing (CPR) coding mode is used for the conversion, and performing, based on the determining, the conversion.

Abstract: To apply a filter to input image data in accordance with an image characteristic. A CNN filter includes a neural network configured to receive an input of one or multiple first type input image data and one or multiple second type input image data, and output one or multiple first type output image data, the one or multiple first type input image data each having a pixel value of a luminance or chrominance, the one or multiple second type input image data each having a pixel value of a value corresponding to a reference parameter for generating a prediction image and a differential image, the one or multiple first type output image data each having a pixel value of a luminance or chrominance.

Abstract: Embodiments of the present disclosure provide a method and device for processing a video signal. A method for decoding an image signal according to an embodiment of the present disclosure comprises the steps of: determining a non-separable transform set index indicating a non-separable transform set used for a non-separable transform of a current block from among non-separable transform sets predefined on the basis of an intra-prediction mode of the current block; determining. as a non-separable transform matrix, a transform kernel indicated by a non-separable transform index for the current block from among transform kernels included in the non-separable transform set indicated by the non-separable transform set index; and applying the non-separable transform matrix to an upper left region which of the current block, which is determined according to the width and height of the current block, wherein each of the predefined non-separable transform sets includes two transform kernels.

Abstract: Innovations in unified intra block copy (“BC”) and inter prediction modes are presented. In some example implementations, bitstream syntax, semantics of syntax elements and many coding/decoding processes for inter prediction mode are reused or slightly modified to enable intra BC prediction for blocks of a frame. For example, to provide intra BC prediction for a current block of a current picture, a motion compensation process applies a motion vector that indicates a displacement within the current picture, with the current picture being used as a reference picture for the motion compensation process. With this unification of syntax, semantics and coding/decoding processes, various coding/decoding tools designed for inter prediction mode, such as advanced motion vector prediction, merge mode and skip mode, can also be applied when intra BC prediction is used, which simplifies implementation of intra BC prediction.

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 intra prediction method according to the present invention comprises the following steps: performing a directional prediction using at least one of a neighboring pixel of a current block and a left upper corner pixel positioned at a left upper corner of the current block so as to obtain a first prediction value for the current block; obtaining a second prediction value for the current block using the reference sample positioned in the current block; and weighted summing the first prediction value and the second prediction value using a weighting matrix so as to obtain a final prediction value for the current block. According to the present invention, image encoding/decoding efficiency may be improved.

Abstract: Generating, by a processor in response to instructions stored on a non-transitory computer readable medium, a reconstructed frame, may include generating a reconstructed block of the reconstructed frame by decoding from an encoded bitstream. Decoding may include decoding a value from the encoded bitstream, identifying, in accordance with the value, a probability distribution for generating the reconstructed block, wherein the value indicates the probability distribution among a plurality of probability distributions determined independently of generating the reconstructed frame, entropy decoding an encoded prediction mode from the encoded bitstream using the probability distribution to identify a prediction mode for generating the reconstructed block, generating a prediction block in accordance with the prediction mode; combining the prediction block and a reconstructed residual block to obtain the reconstructed block, and including the reconstructed block in the reconstructed frame.

Abstract: A system comprises an encoder configured to compress attribute and/or spatial information for a point cloud and/or a decoder configured to decompress compressed attribute and/or spatial information for the point cloud. To compress the attribute and/or spatial information, the encoder is configured to convert a point cloud into an image based representation. Also, the decoder is configured to generate a decompressed point cloud based on an image based representation of a point cloud. In some embodiments, an encoder applies an attribute transfer function to attributes of an image based representation with out-of-loop smoothing such that a decoder may apply any smoothing filter supported by the decoder without being restricted to using a similar smoothing filter as the encoder.

Abstract: A decoder includes circuitry configured to receive a current block, determine the current block is a block for updating an unavailable reference frame based on the current block, and update the unavailable reference frame using the current block. Related apparatus, systems, techniques, and articles are also described.

Abstract: An image decoding method according to the present disclosure comprises deriving a first candidate intra prediction mode based on a first neighboring block of a current block; deriving a second candidate intra prediction mode based on a second neighboring block of the current block; constructing MPM (Most Probable Mode) list of the current block based on the first candidate intra prediction mode and the second candidate intra prediction mode; deriving an intra prediction mode for the current block based on the MPM list; and generating a prediction sample for the current block based on the intra prediction mode, wherein the first neighboring block is a left neighboring block located at the lowermost side among neighboring blocks adjacent to a left boundary of the current block, and wherein the second neighboring block is an upper neighboring block located at the rightmost side among neighboring blocks adjacent to an upper boundary of the current block.

Abstract: An image decoding apparatus includes: a first filter unit configured to apply a first filter to an image (a luminance image and a chrominance image); a second filter unit configured to apply a second filter to an output image of the first filter; a filter set derivation unit configured to decode a filter coefficient from coded data; and a third filter unit configured to apply a third filter to an output image of the second filter by using the filter coefficient. In a case that the third filter unit performs filter processing for the luminance image by using a luminance output image of the second filter, the third filter unit performs processing of clipping an amount of change of a pixel value through the filter processing within a prescribed range of value.

Abstract: Encoding or decoding a picture part of video information can include using a refinement mode per block where the refinement mode can be based on a refinement parameter. The refinement mode can include a cross-component refinement that can be a cross-component chroma refinement. The refinement mode can include enabling selection per block of a refinement parameter where the refinement parameter can include one or more chroma refinement parameters included in a chroma refinement table.

Abstract: An image decoding method according to the present invention may comprise the steps of: generating a merge candidate list of a current block; selecting one merge candidate from merge candidates included in the merge candidate list; and performing motion compensation of the current block on the basis of motion information of the selected merge candidate.

Abstract: A video encoding device includes a local decode generation unit for generating a reference image based on a result of encoding of a divided image, a compression unit for compressing the reference image to generate a compressed data, a reference image storage determination unit for determining whether to store the compressed data in a memory, and an inter-prediction unit for performing motion vector search for inter-coding based on a reference image stored in the memory. The reference image storage determination unit sets an allowable data amount used for storing the reference image for each determined area of the moving image data, and determines whether or not to store the compressed data obtained by compressing the reference image in the memory based on the allowable data amount. Inter-prediction unit sets the reference image corresponding to the compressed data stored in the memory as the search range of motion vector search.

Abstract: A method for decoding an image by a decoding device, according to the present document, comprises the steps of: acquiring image information; and generating a reconstructed picture on the basis of the image information.

Abstract: This application provides an example inter prediction method and a related example apparatus. One example method includes parsing a bitstream to determine prediction information of a to-be-processed picture block, where the prediction information indicates that a prediction direction of the to-be-processed picture block is bidirectional prediction, where the bitstream does not include target identification information, and where the target identification information indicates to perform local illumination compensation (LIC) on the to-be-processed picture block; and obtaining a prediction value of the to-be-processed picture block based on the prediction information.

Abstract: Embodiments for volumetric video encoding and decoding relating to one or more three-dimensional objects are disclosed. In encoding, after mapping from 3D space to 2D plane (802) a point in the 2D plane is examined (805) to determine which points of the 3D object are mapped to the same point to obtain a set of candidate points. Candidate points belonging to a same surface can be used to determine a center of mass for the surface (807). A depth value of the centre of mass is mapped to a 2D projection depth plane (808). A colour value for the centre of mass is interpolated from colour values of points of the set of surface points which are nearest neighbours of the center of mass (810), and used as the colour of the surface in the texture plane (812). Corresponding embodiments for decoding are provided.

Abstract: A method of coding video data includes determining that chroma related syntax elements of the video data are present for luma mapping with chroma scaling (LMCS) for a coding unit (CU) of the video data, coding a syntax element of the video data when the chroma related syntax elements are present for LMCS for the CU, the syntax element is indicative of a value for determining a scaling parameter for chroma scaling in LMCS, and coding a chroma block of the CU based on the scaling parameter for chroma scaling.

Abstract: An example method includes coding, by a video coder and via a coded video bitstream, a syntax element that specifies whether the coded video bitstream includes a plurality of syntax elements that specify parameters of a temporal motion vector prediction (TMVP) candidate derivation process; where the syntax element specifies that the coded video bitstream includes the plurality of syntax elements: coding, by the video coder, the plurality of syntax elements via the coded video bitstream; and deriving, by the video coder and based on parameters specified by the plurality of syntax elements, a TMVP candidate for a current block of a current picture of video data; generating, for the current block, a list of motion vector candidates, the list including the derived TMVP candidate; and predicting, based on the list of motion vector candidates, the current block.

Abstract: A method of decoding a stream of encoded data the method comprising, at a decoder: receiving an encoded dataset comprising multiple tiles; receiving a data structure, said data structure indicative of the amount of data required to encode a plurality of tiles; identifying a portion of the encoded dataset to be decoded by: identifying the tiles associated with the portion to be decoded; determining the location of data related to the tiles based on the amount of data required to encode said tiles; extracting the identified portion of the encoded dataset from the encoded dataset; and decoding said identified portion of the encoded data set.

Abstract: A method and apparatus for encoding or decoding transform coefficients in a video coding system are disclosed. According to this method, a region after zero-outis determined. A remaining number of context-coded bins is determined for the current TB based on a size of the region after zero-out. The current TB is encoded or decoded using context-based coding with a constraint based on the remaining number of context-coded bins. According to another method, a remaining number of context-coded bins is determined for the current TB based on the last significant CG index.

Abstract: A deblocking filter control device that controls a deblocking filter process performed on a decoded image includes: a parameter deriver configured to derive a parameter value that controls a filter strength in the deblocking filter process; and a parameter transformer configured to output a transformed parameter value by transforming the parameter value based on an input bit depth that is a bit depth of the video signal, wherein when the input bit depth is smaller than a predetermined bit depth, the parameter transformer is configured to output the transformed parameter value by adding an offset value to the parameter value and making a bit shift of a result of the addition, and the parameter transformer is configured to change the offset value based on the input bit depth.

Abstract: A method for video processing is provided. The method includes performing downsampling on chroma and luma samples of a neighboring block of the current video block; determining, for a conversion between a current video block of a video that is a chroma block and a coded representation of the video, parameters of cross-component linear model (CCLM) based on the downsampled chroma and luma samples obtained from the downsampling; applying the CCLM on luma samples located in a luma block corresponding to the current video block to derive prediction values of the current video block; and performing the conversion based on the prediction values.

Abstract: A decoder includes circuitry configured to receive a bitstream; store a plurality of long-term reference frames in a reference list; retain a long-term reference frame in the reference list for a length of time based on a retention time; and decode at least a portion of video using the long-term reference frame retained in the reference list. Related apparatus, systems, techniques and articles are also described.

Abstract: An image encoding/decoding method and apparatus are provided. An image decoding method performed by an image decoding apparatus may comprise identifying a current chroma block by splitting an image, identifying whether a matrix based intra prediction mode applies to a first luma sample position corresponding to the current chroma block, identifying whether a predetermined prediction mode applies to a second luma sample position corresponding to the current chroma block, based on the matrix based intra prediction mode doing not apply, and determining an intra prediction mode candidate of the current chroma block based on an intra prediction mode applying to a third luma sample position corresponding to the current chroma block, based on the predetermined prediction mode doing not apply.

Abstract: A method for derivation of a temporal motion data (TMD) candidate for a prediction unit (PU) in video encoding or video decoding is provided. The derived TMD candidate is for inclusion in an inter-prediction candidate list for the PU. The method includes determining a primary TMD position relative to a co-located PU in a co-located largest coding unit (LCU), wherein the co-located PU is a block in a reference picture having a same size, shape, and coordinates as the PU, and selecting at least some motion data of a secondary TMD position as the TMD candidate when the primary TMD position is in a bottom neighboring LCU or in a bottom right neighboring LCU of the co-located LCU, wherein the secondary TMD position is determined relative to the co-located PU.

Abstract: A video decoding apparatus includes matrix reference pixel derivation circuitry that derives reference samples by using top neighboring samples and left neighboring samples of a current block, weight matrix derivation circuitry that derives a weight matrix, matrix prediction image derivation circuitry that derives a prediction image, and matrix prediction image interpolation circuitry that derives a predicted image by using the prediction image. A size index is derived according to a value of a target block width and a value of a target block height. A prediction size is derived using the size index. In a case that a first condition, that both the value of the transform block width and the value of the transform block height are equal to 4, is true, the size index is set equal to 0 and the prediction size is set equal to 4.

Abstract: A set of rough prediction modes including a MPM subset is determined for a code block during image encoding. A first prediction mode having a mode cost less than a first threshold is selected from the set of rough prediction modes, and a second prediction mode having a mode cost less than a second threshold is selected from the MPM subset. A candidate mode subset is determined based on mode types of prediction modes contained in the set of rough prediction modes and a ranking result of mode costs of the prediction modes, when the mode cost of the first prediction mode is different from the mode cost of the second prediction mode. A target prediction mode is determined for the code block from the candidate mode subset. The code block is encoded with the target prediction mode.

Abstract: A method is disclosed. In the method, color differences are calculated between a current video frame and a motion predicted version of the current video frame based on a human visual system's ability to perceive the color differences. Also, information in a difference frame is discarded based on the color differences. The difference frame includes differences between the current video frame and the motion predicted version of the current video frame.

Abstract: A mode decision component is configured to determine the costs of different modes for a selected partition of a frame of a video using an estimated compression coding data, which is calculated prior to a corresponding actual compression coding data being calculated based on another partition immediately prior to the selected partition in a partition processing order. The estimated compression coding data is determined based on a previously calculated compression coding data calculated based on a completed partition prior to the selected partition in the partition processing order. The mode decision component is configured to use the determined costs to select one of the modes. An encoder component is configured to use the selected mode to encode the selected partition by using the corresponding actual compression coding data calculated based on the another partition immediately prior to the selected partition in the partition processing order.

Abstract: A system for decoding a video bitstream includes receiving a reference picture set associated with a frame including a set of reference picture identifiers. The reference picture set identifies one or more reference pictures to be used for inter-prediction of the frame based upon its associated least significant bits of a picture order count based upon the reference picture identifiers. The one or more reference pictures is a second or greater previous frame to the frame having the matching reference picture identifier.

Abstract: A video coding method using inter-layer prediction or referencing is provided. A video decoder receives data from a bitstream carrying data for video pictures in a plurality of different layers. At least one of the plurality of layers comprises temporal sublayers that correspond to levels in a hierarchical temporal prediction structure. Each temporal sublayer is associated with a temporal identifier. The video decoder receives an inter-layer prediction constraint parameter constraining a maximum temporal sublayer used in inter-layer prediction. The video decoder reconstructs a first picture in a first layer by referencing data of a second picture in a second layer. A temporal identifier of the referenced data satisfies the received inter-layer prediction constraint parameter.

Abstract: The disclosure proposes a decoder for decoding coefficients of blocks of a video sequence from a bitstream. The decoder comprises a scan pattern list module for providing one or more pre-defined scan orders, a scan order generator for generating one or more scan orders, a scan order selector for selecting a scan order for each block from the pre-defined and generated scan orders on the basis of scan order information contained in the bitstream, a decoding module for decoding one or more coefficient vectors of each block from the bitstream, a deserializer for inverse scanning, for each block, the one or more coefficient vectors of that block according to the scan order selected for that block so as to obtain a coefficient matrix. The scan order generator generates the one or more scan orders depending on one or more previously obtained coefficient matrices of blocks of the video sequence.

Abstract: Aspects of the disclosure provide methods and apparatuses for video encoding/decoding. In some examples, an apparatus for video decoding includes receiving circuitry and processing circuitry. For example, the processing circuitry decodes prediction information of a current block in a current picture from a coded video bitstream. The prediction information is indicative of an inter prediction mode with a potential usage of a refinement technique based on a first reference picture and a second reference picture. Then, the processing circuitry determines whether a first equal weighting condition of chroma components from the first reference picture and the second reference picture is satisfied. In response to a failure to satisfy the first equal weighting condition of the chroma components from the first reference picture and the second reference picture, the processing circuitry disables the refinement technique in a reconstruction of a sample in the current block.

Abstract: An image encoding/decoding method and apparatus are provided. An image decoding method performed by an image decoding apparatus may include determining a chroma array type of a current image, determining an adaptive loop filter (ALF) indicator of a chroma component based on the chroma array type, and performing ALF filtering with respect to a reconstructed image based on a value of the ALF indicator. The value of the ALF indicator may be determined to be a predetermined value without being obtained from a bitstream, based on the chroma array type being a predetermined type, and the value of the ALF indicator may be obtained from the bitstream, based on the chroma array type being not the predetermined type.

Abstract: A video processing method is provided to include: performing a conversion between a current video block of a video and a coded representation of the video, wherein the performing of the conversion includes configuring, based on a characteristic of the current video block of a video, a context model for coding a bin or bypass coding the bin of a bin string corresponding to an index of a secondary transform tool, wherein the index indicates an applicability of the secondary transform tool and/or a kernel information of the secondary transform tool, and wherein the secondary transform tool includes applying, during encoding, a forward secondary transform to an output of a forward primary transform applied to a residual of a video block prior to quantization, or wherein the secondary transform tool includes applying, during decoding, an inverse secondary transform to an output of dequantization to the video block before applying an inverse primary transform.