Interdigital Vc Holdings, Inc.

Interdigital Ce Patent Holdings, Sas

Interdigital Madison Patent Holdings, Sas

Thomson Licensing

Contentarmor

Interdigital Patent Holdings, Inc.

Interdigital Madison Holdings, Sas

Antoine Robert

Tangi Poirier

Franck Galpin

Fabrice Leleannec

Philippe Bordes

Fabrice LeLeannec

Fabrice Urban

Ya Chen

Karam Naser

Fabien Racape

Gagan Bihari Rath

Gwenael Doerr

Fabrice Le Leannec

Séverine Baudry

Simon Danten

Frederic Lefebvre

Frédéric Lefebvre

Philippe Roudot

Omar Julian Alvarez Gomez

Omar Alvarez Gomez

Systems, methods, and instrumentalities are disclosed for performing local illumination compensation (LIC) with multiple linear models. In an example, a device, such as a video decoding device, or a video encoding device, may determine that sub-partition-based local illumination compensation (sub-LIC) is enabled for a current block. The device may divide the current block into a plurality of sub-partitions. The device may identify a plurality of templates associated with the plurality of sub-partitions. The device may derive a plurality of local illumination compensation (LIC) parameter sets associated with the plurality of sub-partitions based on the plurality of templates associated with the plurality of sub-partitions. The device may process (e.g., encode and/or decode) the current block based on the plurality of LIC parameter sets.

Local illumination compensation with multiple linear models

Implementations are described for determining, for a block being encoded in a picture, at least one predictor candidate, determining for the at least one predictor candidate, one or more corresponding control point generator motion vectors, based on motion information associated to the at least one predictor candidate, determining for the block being encoded, one or more corresponding control point motion vectors, based on the one or more corresponding control point generator motion vectors determined for the at least one predictor candidate, determining, based on the one or more corresponding control point motion vectors determined for the block, a corresponding motion field, and encoding the block based on the corresponding motion field.

Methods and apparatuses for video encoding and video decoding

In one implementation, when coding a block in the intra prediction mode, the block can be split into two sub-partitions by a geometrically located straight line. Each geometric partition within the CU is intra predicted using its own intra mode with its available reference sample. One sub-partition copies and uses the intra prediction mode from the parent block, and another sub-partition uses another implicit or explicit signaled intra prediction mode. After predicting geometric partition, the sample values along the split boundary are adjusted using a blending process with adaptive weights. The geometric partition based intra prediction could be applied for one angular intra prediction mode, or only for one negative-directional intra prediction mode, or only for one specific intra prediction mode (e.g., mode 34). The transform selection or other intra coding tools (i.e., intra sub-partition) can be adapted for the geometric partition based intra prediction.

Intra prediction with geometric partition

A decoding method for decoding a block of an image is disclosed that comprises: determining a split mode for said block in a set of split modes; splitting said block into at least two sub-blocks responsive to said split mode; decoding each of the at least two sub-blocks; wherein said set of split modes comprises at least one split mode for asymmetrically splitting said block into the at least two sub-blocks.

Encoding and decoding methods and corresponding devices

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 Matrix-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.

Intra sub partitions for video encoding and decoding combined with multiple transform selection, matrix weighted intra prediction or multi-reference-line intra prediction

Different implementations are described, particularly implementations for determining a set of predictor candidates for affine merge coding mode from neighboring blocks 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 or AMVP mode for a video content encoder or decoder. The motion model, may be, e.g., an affine model based on top-left/top-right control point motion vectors or an affine model based on top-left/bottom-left control point motion vectors. Such affine model may be signaled by a flag. In an embodiment, predictor candidates are sorted in the set based on a criterion such as, e.g., a validity check or a vectors coherence cost. 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.

Predictor candidates for motion compensation

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.

Extended motion information comparison

Different implementations are described, particularly implementations for video encoding and decoding are presented. Accordingly, the encoding or decoding comprises obtaining a merging candidate index that enables deriving both a first merging candidate index and a second merging candidate index in a triangular shape based motion compensation candidates list in list in use in a triangular shape based motion compensation. According to a particular characteristic, a mapping function determines the derivation process of both indices among a subset of possible combinations of merge candidate indices.

Signaling of merge indices for triangle partitions

PROF (Prediction Refinement with Optical Flow) and BDOF (Bi-directional Optical Flow) use the optical flow model to provide sample-wise motion compensation refinement. In one implementation, to calculate the spatial gradients in BDOF, an extended region is generated around a block to be coded. To simplify the computation, BDOF may use the same padding operations as in PROF, namely, a padding sample is copied from the nearest integer neighbor in the reference picture. BDOF and PROF can also be used together when sub-block based affine motion-compensated prediction is used. BDOF can be applied after PROF generates new prediction blocks, or BDOF can use the spatial gradients in the original prediction blocks to re-use the computations with PROF. In addition, BDOF and PROF operations can be combined, and the prediction adjustment will be directly based on the spatial gradients in the original prediction blocks.

Bi-prediction refinement in affine with optical flow

Video signal coding and decoding functions can generate lists of potential candidates to use in coding and decoding, for example, predictors. Video signal coding component candidate undergo operations before potential inclusion in candidate lists. The candidates are checked after being modified by the operations to see if other equal candidates are already in the candidate list. If equal candidates are not in the list, the modified candidates are added to the candidate list. If equal candidates are already in the list, the modified candidates are not added to the list. Operations that can be performed comprise rounding and clipping.

Method and apparatus for candidate list pruning

To encode a coding unit in the inter modes, there exist multiple inter modes that signal the motion information using a Motion Vector Predictor (MW) list. The MW lists for different coding modes include spatial predictors. In one embodiment, for all coding modes that use MVP lists, the top spatial predictor is first added to the motion vector predictor list before the left spatial predictor. In another embodiment, a subset of coding modes adds the top spatial predictor before the left spatial predictor, and another subset of coding modes adds the left spatial predictor before the top spatial predictor. For example, all merge modes add the top spatial predictor first, and all AMVP modes add the left spatial predictor first. In another example, all non-sub-block modes add the top spatial predictor first, and all sub-block modes add the left spatial predictor first.

Spatial predictor scan order

A video encoder or decoder processes portions of video using virtual temporal affine motion candidates. Under the general aspects, virtual temporal affine candidates are created using only the classical temporal motion buffer information, avoiding the storage of additional affine parameters in a temporal motion buffer. A motion field for encoding or decoding a video block is generated based on the virtual temporal affine candidates. In one embodiment, collocated motion candidates are rescaled by adjusting the picture order count of the determined motion field. In another embodiment, resolution adaptation is performed to enable a current motion buffer to correspond to a reference motion buffer.

Virtual temporal affine candidates

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.

Unified process and syntax for generalized prediction in video coding/decoding

Sub-block merge motion field is combined with triangle partitioning and geometric partitioning modes to further give coding and decoding schemes flexibility. In at least one embodiment, a flag is used to signal if sub-block merge candidates are used in place of regular merge candidates. In another embodiment, regular merge candidates are replaced by sub-block merge candidates. In another embodiment, at least one motion field is stored. In another embodiment, all sub-block merge candidates or only sub-block temporal motion vector predictors or only affine predictors are considered.

Subblock merge candidates in triangle merge mode

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.

Growing community of inventors

Mezieres sur Couesnon, France

Antoine Robert