Abstract: When dependent scalar quantization is used, the choice of the quantizer depends on the decoding of the preceding transform coefficient, and the entropy decoding of a transform coefficient depends on quantizer choice. To maintain high throughput in hardware implementations for transform coefficient entropy coding, several decision schemes of the scaler quantizer are proposed. In one implementation, the state transition and the context model selection are based on only regular coded bins. For example, the state transition can be based on the sum of the SIG, gt1 and gt2 flags, the exclusive-or function of the SIG, gt1 and gt2 flags, or based on only the gt1 or gt2 flag. When a block of transform coefficients is coded, the regular mode bins can be coded first in one or more scan passes, and the remaining bypass coded bins are grouped together in another one or more scan passes.

Abstract: A block of video data is split using at least one splitting rule and coded using existing transform sizes through one of several embodiments. In one embodiment, the block is split using a triple tree splitting operation if said at least two rectangular sub-blocks can be achieved with two successions of split operations with at least one triple tree split. In another embodiment, the video block is split using an asymmetric binary tree splitting if said at least two rectangular sub-blocks can be achieved with two successions of split operations with at least one asymmetric binary split. In another embodiment, a video block is split using successive splits, using both of the rules of the other embodiments.

Abstract: At least a method and an apparatus are presented for efficiently encoding or decoding video. For example, one or more prediction models are determined respectively for one or more prediction candidates used for the video encoding based on one or more control point motion vectors of a current block of the video being encoded or decoded. It is determined from the one or more control point motion vectors that a first prediction model of the one or more prediction models may be a translational prediction model. It is also determined from the one or more control point motion vectors that a second prediction model of the one or more prediction models is to be an affine prediction model. The video is encoded or decoded based on a candidate list comprising the one or more prediction candidates determined respectively from the one or more prediction models.

Abstract: The method for intra frame prediction allows for the recovery of some intra directional modes that are otherwise rendered useless due to the classical padding process. Directional modes are recovered by filling pixel locations in the prediction unit with samples from the portion of the unit that is determined to have samples available for use using a counterpart directional mode to the one that is useless. When it is determined that reference samples are missing for a particular prediction unit or portion thereof given a particular directional mode, a determination is made about whether reference samples along another portion of the prediction unit are available. The other portion is the side of the prediction unit at an opposite end of the particular directional mode.

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 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: 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, refined linear model parameters are determined for a current subblock in the block and for encoding the block, the local illumination compensation uses a linear model for the current subblock based on the refined linear model parameters. In a first embodiment, the number N of reconstructed samples increases with the available data for the subblock. In a second embodiment, partial linear model parameters are determined for the subblock and refined linear model parameters are derived from a weighted sums of partial linear model parameters. In a third embodiment, the subblocks are independently LIC processed.

Abstract: A video coding system uses a value of a chroma quantization parameter table to quantize or de-quantize chroma values of a block of the video, the chroma quantization parameter table being directly coded in a set of parameters at the picture level or at the sequence level of the coded video stream. A corresponding encoding method, encoding device, decoding method, decoding device, video signal, computer program and non-transitory readable medium are proposed.

Abstract: A significance-coefficient flag indicates whether a given quantized transform coefficient is equal to zero or not. To encode the significant-coefficient flags, context-based entropy coding can be used. To adapt to the characteristics of a video sequence, the context model is selected based on the statistics of the transform coefficients. In one embodiment, the non-zero probabilities of transform coefficients are compared to different thresholds to divide a transform block into several context regions, where all coefficients in a context region use the same set of context models. In another embodiment, the transform block is first divided into several context regions based on the positions of the transform coefficients, and the non-zero probabilities of transform coefficients are compared with a threshold to divide each context region into two sub-regions, where all coefficients in a sub-region share the same set of context models.

Abstract: Encoding or decoding syntax information associated with video information can involve identifying a coding context associated with a syntax element of a current coding unit of the video information, wherein the identifying occurs without using a syntax element of a neighboring block, and encoding or decoding the syntax element of the current coding unit based on the coding context.

Abstract: Different implementations are described, particularly implementations for selecting a predictor candidate from a set of multiple predictor candidates for motion compensation of a picture block based on a motion model. The motion model, may be, e.g., an affine model in a merge mode for a video content encoder or decoder. In an embodiment, a predictor candidate is selected from the set based on a motion model for each of the multiple predictor candidates, and may be based on a criterion such as, e.g., a rate distortion cost. The corresponding motion field is determined based on, e.g., one or more corresponding control point motion vectors for the block being encoded or decoded. The corresponding motion field of an embodiment identifies motion vectors used for prediction of sub-blocks of the block being encoded or decoded.

Abstract: In some coding modes, such as the merge mode, a list of motion candidates is generated using spatial or temporal neighboring blocks or constructed ones, and one of the motion candidates is inherited by the current block. When constructing the list of motion candidates, motion information of a candidate to be added is checked to limit the redundancy in the constructed list. In one implementation, the switchable interpolation filter, the IFindex becomes part of the motion information to be used in comparison since it can modify the resulting prediction. Furthermore, the GBiIdx indicating the weights used in bi-prediction can also be part of the motion information to be compared and could also be taken into account in the redundancy check. In general, all or part of motion information that causes different prediction can be used in redundancy check.

Abstract: Aspects aim at improving and simplifying the design of modes similar to CCLM or LIC, that are based on neighboring samples dependent parametric models. Proposed modifications relate to ways of deriving the parameters of the parametric model and designing the parametric-model-based prediction tools contained in a codec in a unified and simplified way. In one embodiment, an approach proposes a simplification of the Cross-component linear model process for deriving the linear parameters. It is proposed to replace the Least Mean Squared method to derive parameters instead as parameters of a straight line passing through two points corresponding to the minimum and maximum luma values among all the luma neighboring reconstructed samples.

Abstract: To encode with CABAC, a non-binary syntax element value is mapped to a binary sequence (bin string), through a binarization process. A binary arithmetic coding engine encodes or decodes a bin, in a regular (context-based) mode and a bypass mode.

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 selecting a predictor candidate from a set of multiple predictor candidates for motion compensation of a picture block based on a motion model. The motion model, may be, e.g., an affine model in a merge mode for a video content encoder or decoder. In an embodiment, a predictor candidate is selected from the set based on a motion model for each of the multiple predictor candidates, and may be based on a criterion such as, e.g., a rate distortion cost. The corresponding motion field is determined based on, e.g., one or more corresponding control point motion vectors for the block being encoded or decoded. The corresponding motion field of an embodiment identifies motion vectors used for prediction of sub-blocks of the block being encoded or 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: Different implementations arc described, particularly implementations for selecting a scan order of the sub-blocks of a current block being encoded or decoded when the current block is composed of multiple sub-blocks. In one example, a corresponding dependency number indicative of a number of the other of the plurality of sub-blocks that each of the sub-blocks uses for spatial prediction is determined, based on the corresponding intra prediction mode for the each of the plurality of sub-blocks. A scan order of the plurality of sub-blocks is determined based on the determined corresponding dependency number for the each of the plurality of the sub-blocks. The current block is encoded or decoded using the determined scan order of the plurality of sub-blocks.

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: A chroma component block vector is initialized using one of a neighboring or collocated luma block vector when current picture referencing mode is used and when dual tree is enabled. In a first embodiment, if a collocated luminance block is not coded in current picture reference mode, a luma vector from a left chroma subblock is used. When the left chroma subblock is not coded in current picture reference mode, a luma vector from the above chroma subblock is used, and if that is not available, a default vector is used. In a second embodiment, a collocated luma block partition is used to derive a chroma block vector.