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: 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).

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 decoding method is presented. At least one high level syntax element is decoded that indicates whether generalized bi-prediction applies for predicting blocks of a slice. A block is then decoded from said slice using generalized bi-prediction in the case where said at least one high level syntax element indicates to apply generalized bi-prediction.

Abstract: Different implementations are described, particularly implementations for video encoding and decoding based on a linear model responsive to neighboring samples are presented. Accordingly, for a block being encoded or decoded in a picture, at least one spatial neighboring template is determined and at least one linear model parameter is determined based on reconstructed samples of the at least one spatial neighboring template. In a first embodiment, the number N of reconstructed samples corresponds to N=2k with k chosen so that n is the maxim integer smaller than sum of the block width and block height. In a second embodiment, the an offset for the relative position of a first sample in the template among samples of a left, respectively top, neighboring line of the block is determined. In a third embodiment, the number of reconstructed samples is set to a higher number in the larger dimension of the block.

Abstract: Different implementations are described for determining one or more illumination compensation parameters for a current block being encoded by a video encoder or decoded by a video decoder, based on the selection of one or more neighboring samples. The selection of the one or more neighboring samples is based on information used to reconstruct a plurality of neighboring reconstructed blocks. The selection may be based on the motion information, such as motion vector and reference picture information. In one example, only samples from neighboring reconstructed blocks that have (1) the same reference picture index and/or (2) a motion vector close to the motion vector of the current block is selected. In another example, if the current block derives or inherits some motion information from a top or left neighboring block, then only the top or left neighboring samples are selected for IC parameter calculation.

Abstract: The present disclosure relates to a method and device for adapting a video content decoded from elementary streams to the characteristics of a display from at least one type of metadata giving information regarding said elementary streams. Such a method comprises:—obtaining (102) an additional information (HDR DESCR.) indicating the presence of one particular type of metadata;—determining if said video content decoded from elementary streams is display-able on said display (11) from said additional information (HDR DESCR.) and the characteristics of the display (EDID); and—if said video content decoded from elementary streams is determined as being displayable, selecting (105) a process from said additional information and the characteristics of the display and adapting (106) the video content according to the selected process.

Abstract: Methods (1100, 1300) and apparatuses (600, 1200) for video coding and decoding are provided. The method of video encoding includes accessing (1110) a reconstructed block corresponding to a block in a picture of a video, determining (1120) at least one filter pattern based on a property of the block and filtering (1130) the reconstructed block according to the at least one filter pattern. The method of video decoding includes accessing (1310) a reconstructed block corresponding to a block in a picture of an encoded video, determining (1320) at least one filter pattern based on a property of the block and filtering (1330) the reconstructed block according to the at least one filter pattern. A bitstream formatted to include encoded data, a computer-readable storage medium and a computer program product are also described.

Abstract: In a video bitstream, Cb and Cr channels are demultiplexed before dequantization instead of after inverse transformation. In this way, regular Cb and Cr quantization control parameters can be used, optionally with minor adjustments when a video block is joint-chroma coded. In one embodiment, some specific quantization control parameters canbe specified. In another embodiment, separate Cb and Cr offsets can be specified for joint chroma coded blocks. In another embodiment, quantization control parameters specific to joint chroma coded blocks can be used for both Cb and Cr channels instead of nominal chroma quantization parameters.

Abstract: At least a method and an apparatus are presented for efficiently encoding or decoding video. For example, an intra prediction of an image block using at least one neural network from a context comprising pixels surrounding the image block is determined and an information relative to a transform method to apply for decoding the image block is also determined. The transform method is adapted to the neural network intra prediction mode of the block to encode or decode. The information relative to the transform method is inferred from the at least one neural network used in intra prediction of the image block at the encoding and either signaled or also inferred at the decoding.

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).

Abstract: In one implementation, to perform in-loop filtering of a version of reconstructed samples of a block, only a single offset parameter is signaled in the bitstream. Based on the version of reconstructed samples, a pixel-wise weight mask is generated using a neural network. Because the neural network parameters are known at both the encoder and decoder, these parameters need not to be signaled in the bitstream. The single offset parameter scaled by the weighted mask is used to adjust the samples in the block. Thus, even though only a single offset parameter is used, the samples are adjusted by pixel-wise offsets. The neural network may also take other parameters, such as quantization parameters and picture types as input. Further, there can be multiple neural networks that generate different weight masks, where different offsets are signaled and one or more of the neural networks are to be selected for filtering.

Abstract: Different implementations are described, particularly implementations for video encoding and decoding using motion compensation with bi-prediction are presented. The encoding method comprises for a picture, obtaining a first predictor for a block of the picture using a first reference picture; obtaining a second predictor for said block of the picture using a second reference picture; using the first predictor and the second predictor for forming a third predictor for the block in bi-prediction inter prediction, wherein the third predictor is obtained as a weighted average of the first predictor and the second predictor; and wherein a weight used in the weighed prediction depend on the position of the sample in the block. Others embodiments are presented for implementing block triangle partition prediction, for implementing block partition prediction using multiple patterns and for corresponding motion compensation in decoding method.

Abstract: For a bi-prediction block, the initial motion field can be refined using a DNN. In one implementation, the initial motion field is integer rounded to obtain initial prediction blocks. Based on the initial prediction, the DNN can generate motion refinement information, which is scaled and added to the sub-pel residual motion from the initial motion field to generate a refined motion field. The scaling factor can take a default value, or be based on the motion asymmetry. While the initial motion field is usually block based on sub-block based, the refined motion field is pixel based or sub-block based and can be at an arbitrary accuracy. The same refinement process is performed at both the encoder and decoder, and thus the motion refinement information need not to be signaled. Whether the refinement is enabled can be determined based on the initial motion, the block activities and the block size.

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 and apparatus to improve compression efficiency in a video compression scheme enables separate control of a local chroma quantization parameter. The control can be used to disable a local chroma quantization parameter. One embodiment uses an existing local luma quantization parameter control flag for controlling local chroma quantization parameter. Another embodiment includes a separate local chroma quantization parameter control flag. Bitstream syntax is used to convey the flags.

Abstract: A video coding system is provided that performs intra prediction in a mode using a neural network for block of only a set of specific block sizes. The signaling of this mode is designed to be efficient in terms of rate-distortion under this constraint. Different transformations of the context of a block and the neural network prediction of this block are introduced in order to use one single neural network for predicting blocks of several sizes, as well as the corresponding signaling. The neural network-based prediction mode considers both luminance blocks and chrominance blocks. The video coding system comprises encoder and decoder apparatuses, encoding, decoding and signal generation methods and a signal carrying information corresponding to the described coding mode.

Abstract: A coding tool set enablement scheme allows one or more coding tools to be used in the encoding or decoding of video data based on one or more characteristics related to the video. In one embodiment, some coding tools are enabled for block sizes below a particular threshold. In another embodiment, a group of coding tools are enabled based on one flag for blocks having a particular characteristic. In another embodiment, these flags are included in a bitstream with the video. In another embodiment, at least one of the flags are inferred to enable some coding tools.

Abstract: In general, encoding or decoding a picture part can involve determining a spatiotemporal motion vector predictor (STMVP) candidate for a merge mode of operation from spatial motion vector candidates taken from spatial positions around a current coding unit (CU) and a temporal motion vector candidate, where at least one embodiment involves determining the STMVP candidate based on considering at most two spatial positions and based on an average of at least two of the spatial and temporal motion vector candidates.

Abstract: In an encoding apparatus or a decoding apparatus, an encoding method or decoding method combines various coding tools with intra sub partitioning mode in which a coding unit is split in multiple sub partitions. At least one embodiment particularly aims at the selection of primary transforms among a set of multiple transforms for video encoding or decoding of intra sub block partitions. At least one embodiment particularly aims at intra coding using Ma-trix-Based Intra Prediction mode combined with Intra Sub Partition mode. At least one embodiment particularly aims at intra coding using Multi-Reference-Line intra prediction mode combined with Intra Sub Partition mode.