Ge Video Compression, LLC

Fraunhofer-gesellschaft Zur Foerderung Der Angewandten Forschung E.v.

Fraunhofer-gesellschaft Zur F&#xf6;rderung Der Angewandten Forschung E. V.

Dolby Video Compression, LLC

Fraunhofer-gesellschaft Zur F&#xd6;rderung Der Angewandten Forschung E.v.

Martin Winken

Thomas Wiegand

Detlev Marpe

Heiko Schwarz

Philipp Helle

Heiner Kirchhoffer

Jonathan Pfaff

Mischa Siekmann

Simon Oudin

Philipp Merkle

Benjamin Bross

Tobias Hinz

Björn Stallenberger

Christian Bartnik

Michael Schäfer

Wojciech Samek

Stephan Kaltenstadler

Roman Rischke

Bjoern Stallenberger

Christian Rudat

Michael Schaefer

Thomas Schierl

Robert Philipp Skupin

Yago Sánchez De La Fuente

Anastasia Henkel

Adam Wieckowski

Paul Keydel

Dominique Maniry

Ivan Zupancic

Michael Schafer

Sebastian Bosse

Jackie Ma

Thomas Wiegard

A video decoder for decoding a video from a data stream using block-based predictive decoding is arranged to derive, using inter prediction, a first prediction, p, for a current block, derive, using intra prediction, a second prediction, p, for the current block determine a scalar weighting parameter, α, based at least in part on a look up table using prediction parameter information of blocks neighboring the current block, determine a prediction signal, q, for the current block as a weighted sum, of the first prediction, p, and the second prediction, p, using, at least in part, the scalar weighting parameter, α, and decode the current block using the prediction signal, q.

Composed prediction and restricted merge

An apparatus configured to select a predetermined intra prediction mode out of a plurality of intra-prediction modes which includes a first set of intra-prediction modes and a second set of matrix-based intra-prediction modes. The apparatus is configured to select a subset of one or more secondary transforms dependent on the predetermined intra prediction mode so that the subset is nonempty in case of the predetermined intra prediction mode being contained in the first set of intra-prediction modes or in the second set of matrix-based intra-prediction modes. The apparatus is configured to derive a transformed version of a prediction residual for a predetermined block, which is related to a spatial domain version of the prediction residual of the predetermined block via a transform defined by a concatenation of a primary transform and a predetermined secondary transform out of the subset of secondary transforms.

Coding using matrix based intra-prediction and secondary transforms

An encoder for hybrid video coding, the encoder for providing an encoded representation of a video sequence on the basis of an input video content, and the encoder configured to: determine one or more syntax elements related to a portion of the video sequence; select a processing scheme to be applied to the portion of the video sequence based a property described by on the one or more syntax elements, the processing scheme for acquiring a sample for a motion-compensated prediction at an integer and/or fractional location within the portion of the video sequence; encode an index indicating the selected processing scheme such that a given encoded index value represents different processing schemes depending on the property described by the one or more syntax elements; and provide, as the encoded representation of the video sequence, a bit stream including the one or more syntax elements and the encoded index.

Encoders, decoders, methods, and video bit streams, and computer programs for hybrid video coding

Coding schemes for coding a spatially sampled information signal using subdivision and coding scheme for coding a sub-division or a multi tree structure are described, wherein representative embodiments relate to picture and/or video coding applications.

Coding of a spatial sampling of a two-dimensional information signal using sub-division

Concepts are described, including encoding of a video into data stream and decoding of a data stream having a video encoded thereinto, using motion compensation prediction between pictures of equal resolution and pictures of different resolution, based on motion vectors at a half-sample resolution and on motion vectors at a different resolution using interpolation filters to obtain sub-sample values within a reference sample array. The interpolation filter is selected from two interpolation filter versions different in a higher edge preserving property, and the selection is depending on whether a current picture is equal in picture resolution to the reference sample array in horizontal and/or vertical dimension, and/or a constraint information in the data stream.

Factional sample interpolation for reference picture resampling

A method for decoding a predetermined block of a picture using intra-prediction by reading, for each of predetermined intra-prediction blocks, from a data stream, a mode index identifying a matrix-based intra-prediction mode is disclosed. Samples of each predetermined intra-prediction block are predicted by computing a matrix-vector product between an input vector derived from reference samples and a prediction matrix associated with the identified matrix-based intra-prediction mode (k)—and associating components of an output vector obtained by the matrix-vector product onto sample positions of the predetermined block. Further predetermined intra-predicted blocks of the picture are predicted to obtain a prediction signal. A transformation flag is decoded from the data stream using context adaptive binary arithmetic coding, and a prediction residual is decoded and re-transformed using a reverse transformation based on the transformation flag to obtain a prediction residual signal. The prediction residual signal is used to correct the prediction signal.

Efficient implementation of matrix-based intra-prediction

A gain in multi-view coding is achieved as follows: the residual signal involved with coding a dependent view of the multi-view signal is predicted from a reference residual signal of the current picture of the reference view using block-granular disparity-compensated prediction, i.e. using disparity compensated prediction with a disparity defined at, and varying with, block granularity so that each block of the current picture of the dependent view has its own disparity displacement such as its own disparity vector, associated therewith. In other words, a remaining similarity between the residual signal involved with predictively coding the reference view is used in order to predict the residual signal involved with predictively coding the dependent view.

Multi-view coding with efficient residual handling

Techniques for block wise encoding and decoding may be applied to encoders, decoders, and methods for encoding or decoding. In one example, there is provided a technique to decode or encode a predetermined block of the picture by assigning, based on a first signalization in the data stream, the predetermined block to a first set or a second set; sorting the assigned set of intra-prediction modes according to intra-prediction modes used for neighboring blocks, neighboring the predetermined block, to obtain a list of intra prediction modes; deriving, for the predetermined block, from the data stream, an index into the list of intra prediction modes; and predicting the predetermined block using an intra prediction mode onto which the index points. The decoder or encoder, if the assigned set is the first set of intra-prediction modes, in sorting the assigned set, uses a second mapping which maps each intra-prediction mode of the second set of prediction modes onto a representative one in the first set of intra-prediction modes.

Affine linear weighted intra predictions

An apparatus for block-wise decoding a picture from a data stream and/or encoding a picture into a data stream, the apparatus supporting at least one intra-prediction mode according to which the intra-prediction signal for a block of a predetermined size of the picture is determined by applying a first template of samples which neighbours the current block onto a neural network. The apparatus may be configured, for a current block differing from the predetermined size, to:

Intra-prediction mode using downsampling for block-wise picture coding

A video encoder for encoding a video into a data stream using motion compensated prediction for inter predicted blocks, comprising a hypothesis number control, configured to control a number of prediction hypotheses of the inter predicted blocks within a predetermined portion of the video to meet a predetermined criterion.

Multi-hypothesis prediction

A better rate distortion ratio is achieved by making interrelationships between coding parameters of different planes available for exploitation for the aim of redundancy reduction despite the additional overhead resulting from the need to signal the inter-plane prediction information to the decoder. In particular, the decision to use inter plane prediction or not may be performed for a plurality of planes individually. Additionally or alternatively, the decision may be done on a block basis considering one secondary plane.

Inter-plane prediction

A previously encoded or reconstructed version of a neighborhood of a predetermined block to be predicted is exploited so as to result into a more efficient predictive coding of the prediction block. In particular, a spectral decomposition of a region composed of this neighborhood and a first version of a predicted filling of the predetermined block results into a first spectrum which is subject to noise reduction and the thus resulting second spectrum may be subject to a spectral composition, thereby resulting in a modified version of this region including a second version of the predicted filling of the predetermined block. Owing to the exploitation of the already processed, i.e. encoded/reconstructed, neighborhood of the predetermined block, the second version of the predicted filling of the predetermined block tends to improve the coding efficiency.

Block-based predictive coding and decoding of a picture

Techniques for encoding/decoding of video signals are described, e.g. implemented in decoders, encoder, methods and non-transitory storage units storing instructions to perform the methods. A decoder or encoder may be configured to predict a predetermined block of the picture using a plurality of neighbouring samples by reducing the plurality of neighbouring samples to obtain a reduced set of samples values lower, in number of samples, than compared to the plurality of neighbouring samples, subjecting the reduced set of sample values to a linear or affine linear transformation to obtain predicted values for predetermined samples of the predetermined block.

Intra predictions using linear or affine transforms with neighbouring sample reduction

Apparatus configured to derive a set-selective syntax element indicating whether the predetermined block is to be predicted using one of a first set of intra-prediction modes comprising a DC intra prediction mode and angular prediction modes. If the set-selective syntax element indicates that the predetermined block is to be predicted using one of the first set of intra-prediction modes, the apparatus is configured to use a list of most probable intra-prediction modes. If the set-selective syntax element indicates that the predetermined block is not to be predicted using one of the first set of intra-prediction modes, the apparatus is configured to use a matrix-based intra-prediction mode. The list of most probable intra-prediction modes is formed such that the list of most probable intra-prediction modes is free of the DC intra prediction mode in case of the neighbouring blocks being predicted by any of the angular intra prediction modes.

Coding of intra-prediction modes

Apparatus for decoding a predetermined block () of a picture using intra-prediction, configured to read, from the data stream (), a mode index (), the mode index pointing to one out of a list () of matrix-based intra-prediction modes. Additionally, the apparatus is configured to predict samples () of the predetermined block () by computing a matrix-vector product () between an input vector () derived from reference samples () in a neighborhood of the predetermined block () and a prediction matrix () associated with the matrix-based intra-prediction mode (k) pointed to by the mode index () and associating components () of an output vector () obtained by the matrix vector product () onto sample positions () of the predetermined block. For each matrix-based intra-prediction mode, all entries of the prediction matrix () associated with the respective matrix-based intra-prediction mode are represented by a fixed point representation of a predetermined bit-depth, the predetermined bit-depth being equal for the matrix-based intra-prediction modes. Furthermore, the apparatus is configured to, for each matrix-based infra-prediction mode, compute the matrix vector product () between the input vector () and the prediction matrix () associated with the respective matrix-based infra-prediction mode (k) by performing, for each component of the output vector, a right shift at a number of bits which is equal for the matrix-based intra-prediction modes.

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Berlin, Germany

Martin Winken