Abstract: A method of decoding JVET video that includes receiving a bitstream indicating how a coding tree unit was partitioned into coding units, and parsing said bitstream to generate at least one predictor based on an intra prediction mode signaled in the bitstream, the intra prediction mode selected from a plurality of intra prediction modes for calculating a prediction pixel P[x,y] at coordinate x,y for the coding unit. A number of intra prediction modes available for coding the coding unit are reduced by replacing two or more non-weighted intra prediction modes by a weighted intra prediction mode.

Abstract: A method for processing a video includes determining characteristics regarding a current video block; determining an operational state regarding unsymmetrical quad-tree (UQT) splitting based on the determination of the characteristics, wherein the operational state indicates that whether the UQT splitting is enabled or disabled and/or indicates how to split the current video block into four partitions using the UQT splitting; and performing a conversion between the current video block and a bitstream representation of the current video block based on the operational state of UQT splitting.

Abstract: A method of decoding image data is provided. The method may include generating a dequantized block of an image based on a coded bitstream; determining whether to use one from among an implicit method and an explicit method for selecting a hybrid transform kernel from among one or more hybrid transform kernel that are available for decoding the dequantized block, wherein the one or more hybrid transform kernel are available for decoding the dequantized block based on associations between prediction modes and sizes of blocks; selecting, by using the one from among the implicit method and the explicit method, the hybrid transform kernel from among the one or more hybrid transform kernel; and performing inverse transform coding of the dequantized block based on the selected hybrid transform kernel.

Abstract: Video decoding innovations for multithreading implementations and graphics processor unit (“GPU”) implementations are described. For example, for multithreaded decoding, a decoder uses innovations in the areas of layered data structures, picture extent discovery, a picture command queue, and/or task scheduling for multithreading. Or, for a GPU implementation, a decoder uses innovations in the areas of inverse transforms, inverse quantization, fractional interpolation, intra prediction using waves, loop filtering using waves, memory usage and/or performance-adaptive loop filtering. Innovations are also described in the areas of error handling and recovery, determination of neighbor availability for operations such as context modeling and intra prediction, CABAC decoding, computation of collocated information for direct mode macroblocks in B slices, reduction of memory consumption, implementation of trick play modes, and picture dropping for quality adjustment.

Abstract: Video decoding innovations for multithreading implementations and graphics processor unit (“GPU”) implementations are described. For example, for multithreaded decoding, a decoder uses innovations in the areas of layered data structures, picture extent discovery, a picture command queue, and/or task scheduling for multithreading. Or, for a GPU implementation, a decoder uses innovations in the areas of inverse transforms, inverse quantization, fractional interpolation, intra prediction using waves, loop filtering using waves, memory usage and/or performance-adaptive loop filtering. Innovations are also described in the areas of error handling and recovery, determination of neighbor availability for operations such as context modeling and intra prediction, CABAC decoding, computation of collocated information for direct mode macroblocks in B slices, reduction of memory consumption, implementation of trick play modes, and picture dropping for quality adjustment.

Abstract: A method for adding at least one additional image frame to a stream of encoded image frames, the stream of encoded image frames comprising image frames encoded by an encoder. An event relating to at least one of: i) a change of operation state of a sender of the stream of encoded image frames, or ii) a change of connection state between the sender and a receiver is detected. Depending on the type of the detected event, the at least one additional image frame is provided. Each at least one additional image frame comprises a reference to a preceding image frame and codes a predetermined visual change relative to the preceding image frame. The predetermined visual change is indicative of the type of the detected event. The at least one additional image frame is added to the stream of encoded image frames to obtain a combined stream of image frames.

Abstract: A method and device for video signal processing are provided. The method includes: an intra prediction mode of a current block is determined, a reference sample for intra prediction of the current block is determined, a predetermined matrix is determined based on the intra prediction mode, and the current block is predicted based on the reference sample and the matrix. The operation of predicting the current block based on the reference sample and the matrix includes a prediction block is generated by applying the matrix to the reference sample.

Abstract: A method and device for video signal processing are provided. The method includes: an intra prediction mode of a current block is determined, a reference sample for intra prediction of the current block is determined, a predetermined matrix is determined based on the intra prediction mode, and the current block is predicted based on the reference sample and the matrix. The operation of predicting the current block based on the reference sample and the matrix includes a prediction block is generated by applying the matrix to the reference sample.

Abstract: A method and device for video signal processing are provided. The method includes: an intra prediction mode of a current block is determined, a reference sample for intra prediction of the current block is determined, a predetermined matrix is determined based on the intra prediction mode, and the current block is predicted based on the reference sample and the matrix. The operation of predicting the current block based on the reference sample and the matrix includes a prediction block is generated by applying the matrix to the reference sample.

Abstract: The present invention relates to a method for encoding/decoding a video. To this end, the method for decoding a video may include: deriving a spatial merge candidate from at least one of spatial candidate blocks of a current block, deriving a temporal merge candidate from a co-located block of the current block, and generating a prediction block of the current block based on at least one of the derived spatial merge candidate and the derived temporal merge candidate, wherein a reference picture for the temporal merge candidate is selected based on a reference picture list of a current picture including the current block and a reference picture list of a co-located picture including the co-located block.

Abstract: Embodiments include systems and methods of performing intra-prediction using enhanced interpolation filters, including applying variable types and degrees of smoothing based on information such as block size, intra-prediction mode. An encoder or decoder may determine an intra-prediction mode for predicting a block of video data and determine a type of smoothing filter to use for the block of video data. The type of the smoothing filter to be used for performing intra-prediction for the block may be determined based on comparing at least one of a width of the block of video data and a height of the block of video data to a threshold.

Abstract: A method of decoding includes partitioning a rectangular transform tree node (TTN) using either a vertical binary tree split or a horizontal binary tree split to generate square child TTNs when a maximum transform unit (TU) size for the TTN is smaller than either dimension of the TTN. The method further includes partitioning the child TTNs using a quadtree split to generate transform units (TUs) when the first child TTN dimension and the second child TTN dimension are larger than the maximum TU size, determining that the child TTNs are TUs when the first child TTN dimension and the second child TTN dimension are less than or equal to the maximum TU size, applying the TUs to transform coefficients to generate residuals, and generating a reconstructed block based on the residuals.

Abstract: Aspects of the disclosure provide a method and an apparatus including processing circuitry for video decoding. The processing circuitry decodes prediction information of a current block in a current picture from a coded video bitstream. The prediction information indicates a prediction mode for the current block being an inter prediction mode or an intra block copy (IBC) mode. The processing circuitry selects a base vector from a candidate list including a block vector candidate used in the IBC mode and determines an offset vector based on offset information that includes directions and sizes for constructing offset vectors. The processing circuitry determines a vector of the current block based on the base vector and the offset vector. The vector is a block vector when the prediction mode is the IBC mode and the vector is a motion vector when the prediction mode is the inter prediction mode.

Abstract: An image encoding/decoding method and apparatus are provided. An image decoding method performed by an image decoding apparatus of the present invention may comprise decoding an indicator indicating whether or not partition information of a current block is derived from partition information of a corresponding block of the current block, obtaining the partition information of the current block based on the decoded indicator, and partitioning the current block based on the obtained partition information.

Abstract: In a method of video encoding, a block vector of a current block of a current picture that is to be coded in intra block copy (IBC) mode is determined. The block vector points to a reference block of the current block in the current picture. The current block is encoded based on the block vector. A first modulo operation is performed on an x component of the block vector and a second modulo operation is performed on a y component of the block vector. The second modulo operation is different from the first modulo operation.

Abstract: A method for decoding a picture block is disclosed. The decoding method comprises: —decoding (10) at least one stream S_diff into decoded data and into one information for identifying a re-constructed reference picture in a decoder picture buffer; —reconstructing (12) a special reference picture from at least the identified reconstructed reference picture and from the decoded data; —reconstructing (16) the picture block from at least the special reference picture, wherein the at least the special reference picture is not displayed.

Abstract: Methods and systems are provided for encoding content using a first encoding algorithm to produce first encoded content. Content can also be encoded using a second encoding alaorithm to produce second encoded content, where the second encoded content can comprise data that can be used to reconstruct the first encoded content. At any time relative to the encoding, a request for the content can be received from a user device. In response to receipt of the request, the first encoded content is transmitted to the user device and the second encoded content is transmitted to the user device.

Abstract: Systems and methods for quick start-up of playback in accordance with embodiments of the invention are disclosed. Media content may be encoded in a plurality of alternative streams and a quick start-up stream. The quick start-up stream may include media content that is encoded at a lower quality that the alternative streams and may be encrypted with a different, less secure encryption process than that of the alternative streams. During a start-up of playback, the playback device streams the media content from a quick start-up stream until a metric, such as a decryption key for the alternative streams is met. The device then streams the media content from the alternative streams in response to the metric being met.

Abstract: A coding device and a decoding device are configured to include an estimated prediction mode deciding section (122a) including: a reference block selecting section (1223a) for selecting a reference block for use in estimating an intra-prediction mode for a subject block; an estimating number deciding section (1222a) for deciding an estimating number of estimated values to be estimated for the intra-prediction mode; and an estimated prediction mode deriving section (1221a) for estimating, based on a reference block, the estimating number of estimated values of the prediction mode.

Abstract: An image coding method includes: adding, to a candidate list, a first adjacent motion vector as a candidate for a predicted motion vector to be used for coding the current motion vector; selecting the predicted motion vector from the candidate list; and coding the current motion vector, wherein in the adding, the first adjacent motion vector indicating a position in a first reference picture included in a first reference picture list is added to the candidate list for the current motion vector indicating a position in a second reference picture included in a second reference picture list.

Abstract: A device for decoding video data includes memory configured to store the video data and processing circuitry. The processing circuitry is configured to determine that a current block of the video data is inter-predicted in a combined inter-intra prediction (CIIP) mode or a geometric partitioning mode (GPM), determine that template matching is enabled for the current block, generate a motion vector for the current block based on template matching; determine a prediction block for the current block based on the motion vector in accordance with the CIIP mode or the GPM, and reconstruct the current block based on the prediction block.

Abstract: The present disclosure relates to an image processing apparatus and an image processing method capable of suppressing a deterioration in image quality. The image processing apparatus includes a threshold value setting unit which sets a threshold value for identifying a feature of neighboring pixels of a current block in an intra prediction process in encoding of image data according to a bit depth of the image data and a filtering processing unit which performs a filtering process on the neighboring pixels by using a filter according to the feature of the neighboring pixels identified by using the threshold value set by the threshold value setting unit. The present disclosure may be applied to, for example, an image processing apparatus.

Abstract: Given a sequence of images in a first codeword representation, methods, processes, and systems are presented for integrating reshaping into a next generation video codec for encoding and decoding the images, wherein reshaping allows part of the images to be coded in a second codeword representation which allows more efficient compression than using the first codeword representation. A variety of architectures are discussed, including: an out-of-loop reshaping architecture, an in-loop-for intra pictures only reshaping architecture, an in-loop architecture for prediction residuals, and a hybrid in-loop reshaping architecture. Syntax methods for signaling reshaping parameters, and image-encoding methods optimized with respect to reshaping are also presented.

Abstract: Embodiments are disclosed for lossless image compression using block-based prediction and context adaptive entropy coding. A method of lossless image compression using block-based prediction and context adaptive entropy coding comprises dividing an input image into a plurality of blocks, determining a pixel predictor for each block based on a block strategy, determining a plurality of residual values using the pixel predictor for each block, selecting a subset of features associated with the plurality of residual values, performing context modeling on the plurality of residual values based on the subset of features to identify a plurality of residual clusters, and entropy coding the plurality of residual clusters.

Abstract: A method for intra prediction comprises determining a first MPM candidate corresponding to a left-side candidate block on the basis of a position of the left-side candidate block adjacent to a left side of a current block; determining a second MPM candidate corresponding to an upper-end candidate block on the basis of a position of the upper-end candidate block adjacent to an upper end of the current block; generating an MPM candidate list including a plurality of MPM candidates, on the basis of the first MPM candidate and the second MPM candidate; and determining one MPM candidate of the pluraity of the MPM candidates that constitute the MPM candidate list as an intra prediction mode of the current block, and performing intra prediction for the current block on the basis of the determined intra prediction mode to generate a prediction block corresponding to the current block.

Abstract: A decoder for block-based decoding of picture data of a picture is configured to decode a current block of the picture by determining first and second sets of luma in a neighborhood of the current block, the first set of luma samples having smaller luma values than the second set of luma samples, fitting a straight-line having a linear function through first and second pairs of luma-chroma samples, wherein the first and second pairs of luma-chroma samples are determined based on the first and second sets of luma samples, respectively, and on first and second corresponding chroma samples, respectively, in said neighborhood of the current block, and predicting chroma samples of the current block using luma samples of the current block and said linear function. The present proposal further concerns a respective encoder and corresponding methods for encoding and decoding.

Abstract: Systems and techniques are provided for processing video data. For example, an apparatus may obtain a reference data block for predicting a block of video data and determine, using an inter-prediction processing path, one or more refined motion vectors based on the reference data block. The apparatus may perform, using the inter-prediction processing path, inter-prediction for the block of video data, wherein the inter-prediction is based on the reference data block and the one or more refined motion vectors.

Abstract: A method for decoding a 360-degree image includes: receiving a bitstream obtained by encoding a 360-degree image; generating a prediction image by making reference to syntax information obtained from the received bitstream; combining the generated prediction image with a residual image obtained by dequantizing and inverse-transforming the bitstream, so as to obtain a decoded image; and reconstructing the decoded image into a 360-degree image according to a projection format. Here, generating the prediction image includes: checking, from the syntax information, prediction mode accuracy for a current block to be decoded; determining whether the checked prediction mode accuracy corresponds to most probable mode (MPM) information obtained from the syntax information; and when the checked prediction mode accuracy does not correspond to the MPM information, reconfiguring the MPM information according to the prediction mode accuracy for the current block.

Abstract: Video decoding innovations for multithreading implementations and graphics processor unit (“GPU”) implementations are described. For example, for multithreaded decoding, a decoder uses innovations in the areas of layered data structures, picture extent discovery, a picture command queue, and/or task scheduling for multithreading. Or, for a GPU implementation, a decoder uses innovations in the areas of inverse transforms, inverse quantization, fractional interpolation, intra prediction using waves, loop filtering using waves, memory usage and/or performance-adaptive loop filtering. Innovations are also described in the areas of error handling and recovery, determination of neighbor availability for operations such as context modeling and intra prediction, CABAC decoding, computation of collocated information for direct mode macroblocks in B slices, reduction of memory consumption, implementation of trick play modes, and picture dropping for quality adjustment.

Abstract: A video decoding method includes: obtaining target type information of a target video upon receiving a play instruction of the target video, the target type information indicating a type of the target video; obtaining specified type information of a plurality of decoders configured in a terminal, the specified type information of the decoders indicating types of videos of which decoding is supported by the decoders; and determining, from the plurality of decoders by comparing the specified type information of the plurality of decoders with the target type information, a target decoder that supports decoding of the target video. The target video is decoded by using the target decoder to play a decoded video.

Abstract: A method of decoding JVET video that includes receiving a bitstream indicating how a coding tree unit was partitioned into coding units, and parsing said bitstream to generate at least one predictor based on an intra prediction mode signaled in the bitstream, the intra prediction mode selected from a plurality of intra prediction modes for calculating a prediction pixel P[x,y] at coordinate x,y for the coding unit. A number of intra prediction modes available for coding the coding unit are reduced by replacing two or more non-weighted intra prediction modes by a weighted intra prediction mode.

Abstract: Embodiments of the present specification provide encoding and decoding methods for a video signal for an inter prediction. The decoding method according to an embodiment of the present specification comprises the steps of: identifying the size of a current block; acquiring an intra block copy (IBC) flag indicating whether or not an IBC is applied to the current block on the basis of the size of the current block and an IBC-allowed block size; determining the prediction mode of the current block on the basis of the IBC flag; and performing prediction of the current block from a reconstructed block in the current picture on the basis of the prediction mode. According to an embodiment of the present specification, coding complexity and coding time can be reduced by encoding/decoding a syntax element related to whether or not IBC mode is applied in consideration of a limited block size.

Abstract: A method for encoding video data is provided that includes determining whether or not a parent coding unit of a coding unit of the video data was predicted in intra-prediction block copy (IntraBC) mode and, when it is determined that the parent coding unit was not predicted in IntraBC mode: computing activity of the coding unit, determining an IntraBC coding cost of the coding unit by computing the IntraBC coding cost of the coding unit using a two dimensional (2D) search when the activity of the coding unit is not than an activity threshold, and computing the IntraBC coding cost of the coding unit using a one dimensional (1D) search when the activity of the coding unit is less than the activity threshold, using the IntraBC coding cost to select an encoding mode from one of a plurality of encoding modes, encoding the coding unit using the selected encoding mode.

Abstract: An image decoder parses an encoded bitstream to obtain a first parameter and a second parameter, and derives a partition mode based on the first and second parameters. Responsive to the derived partition mode being a first partition mode, the image decoder executes the first partition mode including; splitting a block of a picture into a plurality of first blocks including a N×2N block sized N pixels by 2N pixels; splitting the N×2N block, wherein a ternary split is allowed to split the N×2N block in a vertical direction, which is a direction along the 2N pixels, into a plurality of sub blocks including at least one sub block sized N/4×2N, while a binary split is not allowed to split the N×2N block in the vertical direction into two sub blocks that are equally sized N/2×2N; and decoding the plurality of sub blocks.

Abstract: There is provided an image processing apparatus and method that make it possible to suppress degradation of the encoding efficiency. In the case where primary transform that is a transform process for a prediction residual that is a difference between an image and a prediction image of the image is to be skipped, also secondary transform, which is a transform process for a primary transform coefficient obtained by the primary transform of the prediction residual, is skipped. The present disclosure can be applied, for example, to an image processing apparatus, an image encoding apparatus, an image decoding apparatus and so forth.

Abstract: A method of decoding image data is provided. The method may include generating a dequantized block of an image based on a coded bitstream; determining whether to use one from among an implicit method and an explicit method for selecting a hybrid transform kernel from among one or more hybrid transform kernel that are available for decoding the dequantized block, wherein the one or more hybrid transform kernel are available for decoding the dequantized block based on associations between prediction modes and sizes of blocks; selecting, by using the one from among the implicit method and the explicit method, the hybrid transform kernel from among the one or more hybrid transform kernel; and performing inverse transform coding of the dequantized block based on the selected hybrid transform kernel.

Abstract: An image prediction method, apparatus, and system, a device, and a storage medium are provided. The method includes: (401) obtaining a split mode of a current node, where the current node is an image block in a coding tree unit in a current image; (402) determining, based on the split mode of the current node and a size of the current node, whether the current node satisfies a first condition; and (403) when it is determined that the current node satisfies the first condition, performing intra prediction on all coding blocks belonging to the current node, to obtain predictors of all the coding blocks belonging to the current node.

Abstract: According to the disclosure of the present document, when the inter prediction type of a current block indicates bi-prediction, weight index information for candidates in a merge candidate list or a sub-block merge candidate list can be derived, and thus coding efficiency can be increased.

Abstract: A device for coding video data includes a processor configured to generate an inter-prediction block and an intra-prediction block for a current block of video data; for each sample of a prediction block to be generated: determine a first weight for the sample according to a position of the sample in the prediction block; determine a second weight for the sample according to the position of the sample in the prediction block; apply the first weight to a sample at the position in the inter-prediction block to generate a weighted inter-prediction sample; apply the second weight to a sample at the position in the intra-prediction block to generate a weighted intra-prediction sample; and calculate a value for the sample at the position in the prediction block using the weighted inter-prediction sample and the weighted intra-prediction sample; and code the current block using the prediction block.

Abstract: An apparatus including a first module and a second module. The first module may be configured to generate one or more values based upon an analysis of one or more samples of a first frame. The second module may be configured to encode one or more samples of a second frame taking into account the one or more values generated by the first module. The one or more values generally represent a measure of an effect on the one or more samples of the first frame of encoding decisions made during encoding of the one or more samples of the second frame.

Abstract: There is included a method and apparatus comprising computer code configured to cause a processor or processors to perform parsing at least one video parameter set comprising at least one syntax element indicating whether at least one layer in the scalable bitstream is one of a dependent layer of the scalable bitstream and an independent layer of the scalable bitstream, coding a picture in the dependent layer by parsing and interpreting an inter-layer reference picture list, and coding a picture in an independent layer without parsing and interpreting the inter-layer reference picture list.

Abstract: A method for intra prediction comprises determining a first MPM candidate corresponding to a left-side candidate block on the basis of a position of the left-side candidate block adjacent to a left side of a current block; determining a second MPM candidate corresponding to an upper-end candidate block on the basis of a position of the upper-end candidate block adjacent to an upper end of the current block; generating an MPM candidate list including a plurality of MPM candidates, on the basis of the first MPM candidate and the second MPM candidate; and determining one MPM candidate of the plurality of the MPM candidates that constitute the MPM candidate list as an intra prediction mode of the current block, and performing intra prediction for the current block on the basis of the determined intra prediction mode to generate a prediction block corresponding to the current block.

Abstract: A method for decoding a picture block is disclosed. The decoding method comprises: —decoding (10) at least one stream S_diff into decoded data and into one information for identifying a reconstructed reference picture in a decoder picture buffer; —reconstructing (12) a special reference picture from at least the identified reconstructed reference picture and from the decoded data; —reconstructing (16) the picture block from at least the special reference picture, wherein the at least the special reference picture is not displayed.

Abstract: A method by which a decoding device decodes an image, according to the present document, comprises the steps of: generating a restoration picture on the basis of prediction samples of a coding block; deriving a boundary strength (BS) for a boundary of the coding block in the restoration picture; performing deblocking filtering on the boundary of the coding block on the basis of the boundary strength; and deriving a modified restoration picture for the restoration picture on the basis of the deblocking filtering, wherein the boundary strength is derived on the basis of a prediction mode of a first block and a second block that are adjacent to the boundary of the coding block, and the prediction mode of the first block or the second block is derived on the basis of whether the prediction mode of the first block or the second block is a current picture referencing (CPR) mode to be coded in reference to a current picture.

Abstract: An apparatus for video coding includes processing circuitry that encodes prediction information of a current block in a video bitstream. The prediction information indicates a first set of intra prediction direction mode numbers for the current block. The processing circuitry determines whether a first intra prediction direction mode number of a neighboring block of the current block is in the first set of intra prediction direction mode numbers. In response to the first intra prediction direction mode number not being in the first set of intra prediction direction mode numbers, the processing circuitry determines a most probable mode for the current block based on a second intra prediction direction mode number in the first set of intra prediction direction mode numbers that is nearest to the first intra prediction direction mode number. The processing circuitry encodes the current block based on the most probable mode of the current block.

Abstract: An apparatus includes processing circuitry, which determines a block vector that points to a reference block in a same picture as a current block in an intra block copy mode. The current block is one of a plurality of coding blocks in a coding tree block (CTB) with a right to left coding order being allowed within the CTB. The processing circuitry checks that two corner samples of the reference block have been reconstructed based on first outputs from a derivation process for block availability. The processing circuitry checks that a non corner sample of the reference block has been reconstructed based on a second output from the derivation process. The processing circuitry encodes the current block based on reconstructed samples of the reference block after a determination that the two corner samples of the reference block and the non corner sample of the reference block have been reconstructed.

Abstract: A method for in-loop sample offset filtering in a video decoder is disclosed. The method includes obtaining at least one statistical property associated with reconstructed samples of at least a first color component in a current reconstructed data block of a video stream, selecting a target sample offset filter among a plurality of sample offset filters based on the at least one statistical property, the target sample offset filter comprising a nonlinear mapping between sample delta measures and sample offset values, and filtering a current sample in a second color component of the current reconstructed data block using the target sample offset filter and reference samples in a third color component of the current reconstructed data block to generate a filtered reconstructed sample of the current sample.

Abstract: Video decoding innovations for multithreading implementations and graphics processor unit (“GPU”) implementations are described. For example, for multithreaded decoding, a decoder uses innovations in the areas of layered data structures, picture extent discovery, a picture command queue, and/or task scheduling for multithreading. Or, for a GPU implementation, a decoder uses innovations in the areas of inverse transforms, inverse quantization, fractional interpolation, intra prediction using waves, loop filtering using waves, memory usage and/or performance-adaptive loop filtering. Innovations are also described in the areas of error handling and recovery, determination of neighbor availability for operations such as context modeling and intra prediction, CABAC decoding, computation of collocated information for direct mode macroblocks in B slices, reduction of memory consumption, implementation of trick play modes, and picture dropping for quality adjustment.

Abstract: Various concepts which further improve multi-view/layer coding concepts, are described.

Abstract: A method of encoding image data performed by at least one processor, may include: receiving information regarding a data block of an image; performing control so that a residual block composed of residual signals after intra or inter prediction is generated; identifying one or more hybrid transform kernel that are available for encoding the residual block based on associations between prediction modes and sizes of residual blocks; selecting a hybrid transform kernel from among the one or more hybrid transform kernel that are available for encoding the residual block; and performing transform coding of the residual block using the selected hybrid transform kernel.