Abstract: Flexible methods to use a combination of coding modes while keeping good performance tradeoff are implemented with embodiments that determine coding mode information. In one embodiment, determination is made of activation of a first coding mode, and upon determination of whether a second coding mode is used, coding or decoding using the determined modes occurs. Other embodiments enable use of multiple reference lines, intra sub-block partitioning, matrix intra prediction, and low frequency non-separable transforms.

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 method for reconstructing a picture block is disclosed, wherein the block is predicted using local illumination compensation. The parameters of local illumination compensation are determined according to a selection of reconstructed samples located to the left and above of the current block. In the case where some of them are unavailable, they may be replaced using different techniques.

Abstract: A method and an apparatus for encoding or decoding a video are provided. At least one motion compensation interpolation filter for a block of the video is determined. In an embodiment, the length of the motion compensation interpolation filter is adapted based on block conditions. A prediction block is determined based on the at least one motion compensation interpolation filter and a reference block determined for the block and the block of the video is encoded or decoded based at least on the prediction block.

Abstract: A decoding method for decoding blocks of a picture part is disclosed that comprises: decoding a plurality of candidate sets of filter parameters from a bitstream; decoding for a current block of said picture an index identifying one of the candidate sets of filter parameters from said bitstream; decoding said current block from said bitstream; and filtering said decoded current block with the candidate set of filter parameters identified by said decoded index.

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: Decoding and encoding methods and apparatuses are described for at least one first block level parameter for a current block. Bi-directional Optical flow mode allowing refining a motion of samples of a block based on an optical flow for the current block is disabled responsive to the at least one first block level parameter indicating generalized bi-prediction weights are not equal to default weights. The current block is then decoded or encoded accordingly.

Abstract: Various embodiments relate to a video coding system in which some elements required for decoding are generated according to a process that not specified within the video coding system. This process is hereafter referenced to as being the “external” process. This external process may generate “external” reference pictures to be used by a decoder that is adapted to use these external pictures. Encoding method, decoding method, encoding apparatus, decoding apparatus based on this post-processing method are proposed.

Abstract: A method for decoding a video sequence representing original video data comprising a first picture of the video sequence having a feature related to a chroma component of the first picture different from a same feature related to a chroma component of a second picture of the video sequence, the feature related to a chroma component being representative of a chroma format and/or of a relative position of chroma samples with respect to luma samples.

Abstract: Methods and apparatuses to improve compression efficiency in a video compression scheme are described to enable flexible use of local illumination compensation. Such methods comprise individual local illumination compensation for components of a video block. Such methods also comprise flexible derivation methods for illumination compensation information. In one embodiment, local illumination compensation information can be inherited from other others, such as neighboring blocks.

Abstract: Template based derivation of intra sub-partitioning (ISP) mode is used to improve coding efficiency of intra predicted coded video blocks. The template is formed from surrounding reconstructed top and left samples. In one embodiment, ISP is performed independently from template based intra mode derivation (TIMD). The derivation of an intra sub-block partition mode is determined from template pixels using a current prediction mode for either an upper or left template. In another embodiment, ISP and TIMD are combined. In a further embodiment, a flag is signaled to communicate template based intra mode derivation and intra sub-block partition usage.

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: Inferring an illumination compensation flag during encoding or decoding of a video image signal using frame rate up conversion can save one bit and eliminate complexity. The illumination compensation flag can be derived from the corresponding flags of at least one bi-predictive or bi-directional prediction candidates. The flag can also be derived from some function of the flags from those candidates. Alternatively, several flags can be used for respective coding or decoding of blocks if there are more than one prediction candidate using illumination compensation.

Abstract: A method for decoding. the method comprising: obtaining an ordered list of a plurality of positions in a spatial neighborhood of a current block in a picture; parsing the list in order until first motion information is available at one of the positions and second motion information is available at a position in a reference picture designated by the first motion information; using the second motion information to obtain at least one motion vector predictor candidate to be inserted in at least one list of motion vector predictor candidates used for predicting a motion vector used for the current block.

Abstract: Video processing such as encoding and/or decoding a picture can involve deriving an inter-prediction parameter based on first and second merge candidates used to generate a pairwise merge candidate, wherein the inter-prediction parameter comprises at least one of an index for weighted bi-prediction or an interpolation filter index; and encoding at least a portion of the picture information based on the inter-prediction parameter.

Abstract: In a video coding system, it is proposed to adapt video coding tools to the use of Reference Picture Re-scaling where a reference picture has a different size than the current picture to be coded or decoded. Different embodiments are proposed hereafter, introducing some tools modifications to increase coding efficiency and improve the codec consistency when RPR is enabled. A video encoding method, a decoding method, a video encoder and a video decoder are described.

Abstract: A method includes decoding a first portion of video data consisting of an information set consisting of information representative of a plurality of candidate sets of sample adaptive offset filter parameters. A set of sample adaptive offset parameters comprises information representative of an offset to be added to a sample value of a current block. A first syntax element representing an index that identifies a first candidate set of the plurality of candidate sets of sample adaptive offset filter parameters is decoded from the video data for the current block. The current block is decoded from a second portion of the video data different from the first portion. The decoded current block is filtered with the first candidate set identified by the index. The first portion is signaled with syntax elements at a level of a block of a group of blocks comprising the current block decoded first in decoding order.

Abstract: Described are methods and apparatus for estimating weighted prediction parameters intended to be used for predicting an image block. A component of an image block of a video may be precited from a set of options that includes a first version of weighted prediction parameters, a refined version of the weighted prediction parameters, or no weighted prediction parameters, and the image block may be encoded.

Abstract: A decoding method is disclosed. It comprises: —decoding parameters for a current block; —disabling a first coding tool for said current block in the case where one or more of the following conditions is verified: a second coding tool is used for said current block and a given condition on the decoded parameters is verified; —enabling for said current block said first coding tool otherwise; and —decoding said current block using said first coding tool if said first coding tool is enabled.

Abstract: A decoding method is disclosed. A quantization parameter of at least one luma block is obtained. The at least one luma block comprises a luma sample co-located with at least one chroma sample selected in a current chroma block. The luma and chroma blocks are coded in dual tree mode. A quantization parameter of the current chroma block is then determined responsive to the quantization parameter of the at least one luma block. Finally, the current chroma block is decoded using the quantization parameter of the current chroma block.