Abstract: Apparatuses and methods are disclosed including techniques for encoding and decoding video data. The disclosed techniques include obtaining video data, including data representing a video data region, and then computing models used for cross-component based prediction of chroma samples from the video data region. The computing of models includes accumulating concurrently data of multiple models using a single loop through reference samples selected from the video data. The accumulated data of the models are generated based on the reference samples according to their classification into respective classes. The models are then applied using a single loop through samples of the video region, the models applied to predict the chroma samples according to their classification into the respective classes.

Abstract: Described are methods and apparatuses for encoding/decoding a picture comprising predicting at least one block, wherein the predicting comprises performing motion compensation and local illumination compensation based on a reference block, the local illumination compensation including applying a linear model based on sums of absolute differences of neighboring reconstructed samples and corresponding reference samples of the reference block, wherein the neighboring reconstructed samples and corresponding reference samples of the reference block are co-located according to an L-shape substantially adjacent to the block to be predicted, the L-shape comprising a row of pixels located to the top side of the predicted block and a column of pixels located to the left side of the predicted block, the co-location being determined according a motion vector of the predicted block.

Abstract: Systems and methods are disclosed including techniques for encoding and decoding video data. The disclosed techniques include obtaining video data, including luma and chroma samples, and coding a chroma sample of the chroma samples. The coding of a chroma sample comprises deriving a phase-based model and then predicting the chroma sample using the phase-based model. The phase-based model is a function of a corresponding luma sample, a gradient, and a chroma phase. The disclosed techniques also include obtaining a bitstream that codes video data, including luma and chroma samples, and decoding a chroma sample of the chroma samples. The decoding of the chroma sample comprises deriving a phase-based model and then predicting the chroma sample using the phase-based model.

Abstract: Systems, devices, and methods are described herein for local illumination compensation (LIC) with extended models. An example device for video decoding may determine an LIC model for a block; obtain a set of LIC parameters based on the determined LIC model for the block; and decode the block based on the set of LIC parameters. An example device for video encoding may select a LIC model, from a plurality of LIC models, for block; obtain a set of LIC parameters based on the selected LIC model for the block; and encode the block based on the set of LIC parameters.

Abstract: Systems, methods, and instrumentalities are disclosed for performing regression-based intra prediction mode (IPM) blending. Regression-based intra prediction may be computed (e.g., iteratively computed) as a linear combination of parameters derived from the template. A video decoding device may be configured to obtain a template associated with a block, including reconstructed samples and corresponding predicted samples of the template. The video decoding device may determine weights based on minimizing a difference of the predicted samples and the corresponding reconstructed samples. The video decoding device may apply the weights to respective parameters to determine an intra prediction model. Parameters may include reconstructed samples and/or iteratively derived prediction samples that neighbor a sample location. The video decoding device may determine intra prediction samples for the block based on the intra prediction model.

Abstract: Systems, methods, and instrumentalities may be provided for history-based motion vector prediction (HMVP) candidate reordering. A video decoding device may obtain a history-based motion vector prediction (HMVP) candidate list for a current block, the HMVP list comprising multiple HMVP candidates. The device may determine a template matching cost of an HMVP candidate from the multiple HMVP candidates. The device may reorder the HMVP candidate list based on the template matching cost of the HMVP candidate. The device may decode the current block based on the reordered HMVP candidate list.

Abstract: A video codec can involve determining a motion compensation mode associated with encoding a first block of picture information, the motion compensation mode including a sub-block based motion compensation prediction mode or a non-rectangular block partition mode; determining that a second block of picture information spatially neighboring the first block was encoded or decoded based on an illumination compensation; and encoding or decoding the first block based on the motion compensation mode and the illumination compensation.

Abstract: A method includes encoding a first message including first parameters for a first color transform that transforms a video signal into a first color-mapped video signal; encoding a second message including second parameters for a second color transform that transforms the video signal into a second color-mapped video signal; and encoding the video signal, the first message, and the second message in a video bitstream. A method includes decoding the video bitstream into the video signal, the first message including the first parameters, and the second message including the second parameters, and performing at least one of the following: displaying the video signal; transforming the video signal into the first color-mapped video signal by applying the first color transform and displaying the first color-mapped video signal; and transforming the video signal into the second color-mapped video signal by applying the second color transform and displaying the second color-mapped video signal.

Abstract: A device may be configured to perform one or more actions. The device may be configured to obtain a value associated with quantization parameter correction for context-adaptive entropy decoding. The device may be configured to obtain a slope coefficient and an offset coefficient. The device may be configured to determine an initial value of a probability state associated with the context-adaptive entropy decoding based on the slope coefficient, the offset coefficient, and the value associated with the quantization parameter correction. The device may be configured to perform the context-adaptive entropy decoding based on the initial value of the probability state.

Abstract: A method for decoding or encoding comprising: determining if an inter prediction mode called weighted prediction is enabled for a current block; and, if weighted prediction is enabled, modifying a part of a reconstruction process of said current block related to the weighted prediction and/or to at least another prediction tool of a first set of prediction tools, the first set comprising a triangle prediction mode, a geometrical prediction mode, a local illumination compensation mode, a combined intra inter prediction mode, and modes in which motion information used for motion compensation may be refined based on an optical flow model.

Abstract: Apparatuses and methods are disclosed for encoding and decoding data, including video blocks. Techniques disclosed include adapting a decoder-side motion vector refinement (DMVR) process to coding tools with an illumination change. For a video block being encoded or decoded, the DMVR process includes determining that at least one coding tool, of the coding tools with the illumination change, is enabled; and performing the DMVR process, where a distortion metric is selected based on the enabled coding tool.

Abstract: In general, encoding or decoding a picture part can involve a first CABAC probability model associated with a first flag indicating use of an affine mode and a second CABAC probability model associated with a second flag indicating use of either the affine mode or a second mode different from the affine mode, where the first and second CABAC probability models are different and are determined independently.

Abstract: Methods and apparatus for performing in-loop filtering in an encoder or a decoder provide regions which use a common set of filter parameters An index can be sent from an encoder to a decoder indicating which set of filter parameters is to be used for a particular region. The in-loop filter can be Sample Adaptive Offset, Adaptive Loop Filter, or any other such filter. An encoder classifies regions of a picture according to blocks using a common set of filter parameter. The classification can be in the form of a map. Filtering blocks use the common set of filter parameters for a region. A decoder parses a bitstream for a set of filter parameters and an index indicative of the filter parameter set for a region being decoded.

Abstract: Different implementations are described, particularly implementations for video encoding and decoding are presented including a method for deblocking an image. According to an implementation, in a method for deblocking an image, at least one boundary is determined between a first block of samples and a second block of samples; a boundary strength is determined according to at least one of a prediction mode of the first block and a prediction mode of the second block; and samples of the first and second blocks neighboring the at least one boundary are filtered according to the boundary strength. Advantageously, in case the prediction mode of the first block is a weighted prediction mode, the boundary strength further depends on the relative weight of samples used in predicting the first block of samples according to the weighted prediction mode of the first block and reciprocally for the second block.

Abstract: A restricted syntax range per layer in a multi-layer video coding scheme prevents inter-layer conflicts. In one embodiment, adaptive loop filtering sets defined in an adaptive parameter set are distinct in the multiple layers. In another embodiment, a layer identification is also used to uniquely identify the adaptation parameter set. In a related embodiment, a high-level syntax flag indicates whether a layer is independent of other layers.

Abstract: A method and an apparatus for encoding or decoding a video wherein for at least one first block to encode or decode, at least one reference sample is determined based on a coding mode used for reconstructing at least one second block. For instance, intrapadding or motion-compensation of a third block to which the at least one reference sample belong is performed using coding data of the at least one second block. A prediction is then obtained for the at least one first block using the at least one reference sample, and the at least one first block is encoded or decoded based on the prediction.

Abstract: A video coding system may use different types of templates when using template-based prediction modes such as intra template matching prediction mode. The ‘L-shape’ template conventionally used by template-based coding tools may be split into a horizontal ‘above’ (or ‘upper’) template and a vertical ‘left’ template. This allows the encoder to select the appropriate part of the template that better captures statistical properties of the current block and results into improving the coding performance. The use of the type of template is signaled in the encoded data so that the decoder can use the appropriate template for the reconstruction when using a template-based prediction mode such as intra template matching prediction mode.

Abstract: A method comprising obtaining (711) from video data an information allowing determining a picture order count difference between a picture order count of a current reference picture of a list of reference pictures associated to a current picture and a picture order count of the current picture; determining (712) the picture order count difference from the information; and, determining (713) a picture order count of the current reference picture from the picture order count difference; wherein, the determining of the picture order count difference from the information is based at least on a temporal identifier of the current picture.

Abstract: Encoding and decoding methods are disclosed wherein directional intra prediction is used. Each directional intra prediction mode of a given set is associated (S100) with a sum of gradient's values associated with pixels whose direction perpendicular to gradient's direction is the closest to a direction of said directional intra prediction mode and with information representative of a spatial position of each pixel contributing to the sum. At least two directional intra prediction modes are selected (S102) associated with the sums of largest amplitude and at least two predictions of said current picture block are obtained (S107) from them. Finally: the at least two predictions are blended (S108) based on information representative of a spatial position of at least one pixel contributing to the sum associated with at least one of said selected directional intra prediction modes. The current picture block is reconstructed (S110) from the blended prediction.

Abstract: A Local illumination compensation system for video encoding and decoding uses memory for storing illumination compensation parameters and does not require access to reconstructed pixels of neighboring blocks. A set of illumination compensation parameters is stored in a dedicated buffer, which is of limited size, and which is decoupled from the coding unit level storage of information. The buffer contains a set of illumination compensation parameters, which may be, for example, computed (or determined in some other manner) on the fly or determined beforehand (for example for example obtained from the video signal or from a device).