Abstract: At least a method and an apparatus are provided for efficiently encoding or decoding video. For example, a plurality of different motion prediction modes for a current block are obtained. The current block is encoded or decoded based on a combination of the plurality of different motion prediction modes with corresponding weights for a plurality of sub-blocks of the current block, wherein the combination with the corresponding weights comprising an inter prediction mode and an intra prediction mode.

Abstract: A decoding method is disclosed. First, context for a syntax clement associated with a current transform coefficient of a block of a picture is determined. The context is determined based on the area of said block, on the position of the current transform coefficient within the block and on the number of non-zero neighboring transform coefficients in a local template. Second, the syntax element is decoded based at least on the determined context. Advantageously, the local template depends on the shape of said block.

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 of performing intra prediction for encoding or decoding uses multiple layers of reference samples. The layers are formed into reference arrays that are used by a function, such as a weighted combination, to form a final prediction. The prediction is used in encoding or decoding a block of video data. The weights can be determined in a number of ways, and for a given prediction mode, the same weights, or different weights can be used for all pixels in a target block. If the weights are varied, they can depend on the distance of the target pixel from reference arrays.

Abstract: The present principles relate to a method and device. A method for encoding a residual block comprises: obtaining (500) a first coding mode relative to a first 2D transform when coding the residual blocks according to a coding mode relative to a first 2D transform is enabled; obtaining (510) a second coding mode relative to a second 2D transform when coding the residual blocks according to a coding mode relative to a second 2D transform is enabled; and encoding (530) the residual block according to either said first coding mode or said second coding mode or both; the method is characterized in that enabling or disabling (520) the coding of the residual block according to said second coding mode depends on said first coding mode. The present principles relate also to a method and device for encoding/decoding a picture.

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: At least a method and an apparatus are provided for efficiently encoding or decoding video. For example, a plurality of different motion prediction modes are obtained for a current block. The current block is encoded or decoded based on a combination of the plurality of different motion prediction modes with corresponding weights, wherein the combination with the corresponding weights comprising at least two inter prediction modes, or an inter prediction mode and an intra prediction mode. Both triangle prediction and multi-hypothesis prediction are allowed to be indicated in one or more lists of possible motion vector candidates, such as, e.g., in advanced motion vector prediction (AMVP) mode.

Abstract: A method of performing intra prediction for encoding or decoding uses multiple layers of reference samples. The layers are formed into reference arrays that are used by a function, such as a weighted combination, to form a final prediction. The prediction is used in encoding or decoding a block of video data. The weights can be determined in a number of ways, and for a given prediction mode, the same weights, or different weights can be used for all pixels in a target block. If the weights are varied, they can depend on the distance of the target pixel from reference arrays.

Abstract: A decoding method is disclosed. First, context for a syntax element associated with a current transform coefficient of a block of a picture is determined. The context is determined based on the area of said block, on the position of the current transform coefficient within the block and on the number of non-zero neighboring transform coefficients in a local template. Second, the syntax element is decoded based at least on the determined context. Advantageously, the local template depends on the shape of said block.

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 comprising obtaining an encoded video stream comprising a bitstream portion gathering high level syntax elements, at least one of said syntax elements providing an information indicating if a use of an encoding tool or feature corresponding to that high level syntax element is allowed in the encoded video stream; and, determining from a high level syntax element comprised in the bitstream portion if a use of an encoding tool or feature is allowed for decoding the encoded video stream, wherein the encoding tool or feature is at least one of Multi-Type Tree, a scaling matrix, Long Term Reference Picture, a maximum transform unit size equal to a predetermined highest possible maximum transform unit size or weighted prediction.

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: The present principles relate to a method and device. A method for encoding a residual block comprises: obtaining (500) a first coding mode relative to a first 2D transform when coding the residual blocks according to a coding mode relative to a first 2D transform is enabled; obtaining (510) a second coding mode relative to a second 2D transform when coding the residual blocks according to a coding mode relative to a second 2D transform is enabled; and encoding (530) the residual block according to either said first coding mode or said second coding mode or both; the method is characterized in that enabling or disabling (520) the coding of the residual block according to said second coding mode depends on said first coding mode. The present principles relate also to a method and device for encoding/decoding a picture.

Abstract: Different implementations are described, particularly implementations for video encoding and decoding are presented. Accordingly, the encoding or decoding comprises obtaining parameters of a decoded picture buffer used in decoding an encoded picture. The signaling of parameters relative to the decoded picture buffer is controlled by a syntax data element sps_sublayer_dpb_params_flag related to the control of the presence of syntax elements in a decoded picture buffer parameters syntax structure in a SPS. According to a particular characteristic, the syntax data element sps_sublayer_dpb_params_flag is inferred to zero when the syntax data element sps_ptl_dpb_hrd_params_present_flag specifies that decoded picture buffer parameters syntax structure is not present in the SPS.

Abstract: Methods and apparatus for implementing Discrete Trigonometric transforms are based on maximum transform size. In one embodiment, matrix-based intra prediction is enabled for coding unit sizes up to a specified size, regardless of the maximum transform size. In another embodiment, low-frequency non-separable transforms are used to improve coding gain. Syntax in a bitstream can be used to indicate a coding tool that is used.

Abstract: At least a method and an apparatus are provided for efficiently encoding or decoding video. For example, a plurality of different motion prediction modes for a current block are obtained. The current block is encoded or decoded based on a combination of the plurality of different motion prediction modes with corresponding weights for a plurality of sub-blocks of the current block, wherein the combination with the corresponding weights comprising an inter prediction mode and an intra prediction mode.

Abstract: Different implementations are described, particularly implementations for video encoding and decoding based on wherein the partitioning tree structure is partially shared between luma and chroma blocks are presented. According to an implementation, a single partitioning tree structure is shared between luma and chroma blocks from a root node of the partitioning tree down to a switching node and a dual partitioning tree structure is determined for luma and chroma blocks from the switching node down to a leaf node of the partitioning tree. Thus, this implementation optimizes the coding efficiency by allowing separated trees for smaller blocks, while limiting the complexity of decoding pipeline.

Abstract: Different implementations are described, particularly implementations for video encoding and decoding are presented. Accordingly, the encoding or decoding comprises obtaining a residual coding mode of a block of a picture, wherein the residual coding mode is one of regular residual coding mode (RRC) or transform skip residual coding mode (TSRC); decoding the block of the picture according to the obtained residual coding mode. According to a particular characteristic, the residual coding mode is set to regular residual coding mode (RRC) when transform skip is disabled. According to another particular characteristic, the residual coding mode is decoded from a syntax element when transform skip is enabled.

Abstract: In some chroma formats, monochrome processing is performed for each color component. For example, for 4:0:0, only luma components exist, and all chroma related syntax and code are not used. In addition, for 4:4:4 when separable color plane is activated, the chroma components are treated as independent luma components, and the codec may behave as if no chroma is present at all and no chroma related tools are used. To reduce redundancy in coding parameters related to chroma, in one implementation, a flag indicating the availability of chroma components is coded. In another implementation, inter-related syntax is omitted in an intra-only coding mode for video data. In addition, slice level control of LMCS is provided.