Ge Video Compression, LLC

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

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

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

Dolby Video Compression, LLC

Thomson Licensing

Heiko Schwarz

Thomas Wiegand

Detlev Marpe

Heiner Kirchhoffer

Philipp Helle

Martin Winken

Benjamin Bross

Tobias Hinz

Tung Nguyen

Mischa Siekmann

Jan Stegemann

Jonathan Pfaff

Philipp Merkle

Christian Bartnik

Phan Hoang Tung Nguyen

Simon Oudin

Haricharan Lakshman

Karsten Suehring

Ali Atef Ibrahim Khairat Abdelhamid

Adam Wieckowski

Sebastian Bosse

Valeri George

Detlef Marpe

Jens Brandenburg

Jackie Ma

Björn Stallenberger

Thomas Schierl

Santiago De Luxán Hernández

Christian Helmrich

Christian Rudat

Paul Haase

Robert Philipp Skupin

Yago Sánchez De La Fuente

Michael Schäfer

Gerhard Tech

Karsten Mueller

Paul Keydel

Christian Lehmann

Hunn Rhee

Wojciech Samek

Stephan Kaltenstadler

Heribert Brust

Roman Rischke

Bjoern Stallenberger

Anastasia Henkel

Michael Schaefer

Gayathri Venugopal

Dominique Maniry

Ivan Zupancic

Michael Schafer

Stefan Matlage

Johannes Erfurt

Lim Wang-Q

Simone Walter

Matthias Preiss

Dan Grois

Klaus-Robert Mueller

Aljoscha Smolic

Brad Schumitsch

Thomas Weigand

Patrick Ndjiki-Nya

Georg Maier

Karsten Müller

Thomas Wiegard

Soenke Schmidt

Soeren Becker

Wang-Q Lim

Jennifer Rasch

Remco C Veltkamp

Heiner Kirchhoffeer

Gitta Kutyniok

Philipp Merkel

Bela Makai

An encoding scheme is provided for arithmetically encoding a sequence of information values into an arithmetic coded bitstream by providing the bitstream with entry point information, allowing for resuming arithmetic decoding of the bitstream from a predetermined entry point onward. A respective decoding scheme is also provided. These encoding and decoding schemes provide more efficient encoding in view of the decoding speed.

Arithmetic encoder for arithmetically encoding and arithmetic decoder for arithmetically decoding a sequence of information values, methods for arithmetically encoding and decoding a sequence of information values and computer program for implementing these methods

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

A higher coding efficiency for coding a significance map indicating positions of significant transform coefficients within a transform coefficient block is achieved by the scan order by which the sequentially extracted syntax elements indicating, for associated positions within the transform coefficient block, as to whether at the respective position a significant or insignificant transform coefficient is situated, are sequentially associated to the positions of the transform coefficient block, among the positions of the transform coefficient block depends on the positions of the significant transform coefficients indicated by previously associated syntax elements. Alternatively, the first-type elements may be context-adaptively entropy decoded using contexts which are individually selected for each of the syntax elements dependent on a number of significant transform coefficients in a neighborhood of the respective syntax element, indicated as being significant by any of the preceding syntax elements.

Coding of significance maps and transform coefficient blocks

Concepts for transform coefficient block coding are described which enable coding of coefficients of a transform block in a manner suitable for dependent quantization and effectively implementable by entropy coding in terms of coding efficiency.

Entropy coding of transform coefficients suitable for dependent scalar quantization

Decomposing a value range of the respective syntax elements into a sequence of n partitions with coding the components of z laying within the respective partitions separately with at least one by VLC coding and with at least one by PIPE or entropy coding is used to greatly increase the compression efficiency at a moderate coding overhead since the coding scheme used may be better adapted to the syntax element statistics. Accordingly, syntax elements are decomposed into a respective number n of source symbols swith i=1 . . . n, the respective number n of source symbols depending on as to which of a sequence of n partitions into which a value range of the respective syntax elements is sub-divided, a value z of the respective syntax elements falls into, so that a sum of values of the respective number of source symbols syields z, and, if n>1, for all i=1 . . . n−1, the value of scorresponds to a range of the ipartition.

Entropy encoding and decoding scheme

A video encoder is configured to encode, by block based predictive encoding, pictures of a video into coding data, wherein the block based predictive encoding includes an intra-picture prediction. The video encoder is configured to use, for the intra-picture prediction, for encoding a prediction block of a picture, a plurality of nearest reference samples of the picture directly neighboring the prediction block and a plurality of extended reference samples, each extended reference sample of the plurality of extended reference samples separated from the prediction block at least by one nearest reference sample of the plurality of reference samples. The video encoder is further configured to sequentially determine an availability or unavailability of each of the plurality of nearest reference samples and to substitute a nearest reference sample being determined as unavailable by a substitution sample. The video encoder is configured to use the substitution sample for the intra-picture prediction.

Extended reference intra-picture prediction

A video decoder employs context-adaptive binary arithmetic coding for decoding a video from a data stream. The video decoder determines a parametrization for the context-adaptive binary arithmetic coding.

Determining a parametrization for context-adaptive binary arithmetic 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 presented which achieve a more efficient coding of coefficients of a transform block by use of dependent quantization and context adaptive entropy coding or achieve a coding of coefficients of a transform block in a manner which allows a more efficient coding even if a usage of dependent quantization is combined with the usage of context adaptive entropy coding.

Efficient coding of transform coefficients using or suitable for a combination with dependent scalar quantization

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

Block-based coding of a picture is done by providing an intra-prediction coding concept according to which a certain block of the picture is intra-prediction coded using a certain intra-coding mode by partitioning the predetermined block into partitions which are, for reconstruction purposes, sequentially subject to spatial prediction using the intra-prediction coding mode signaled for the certain block followed by correcting the thus obtained predictor using a prediction residual so that for preceding partitions a reconstruction of the samples is available to the decoder at the time of processing the next, then current, partition.

Partitioned intra coding concept

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

Rendered portions of a renderable portion of a first view of a multi-view signal are introduced into a prediction loop of a multi-view encoder to form a reference signal for the block-based prediction of the encoder's view predictor may improve the prediction and thereby increasing the coding efficiency. The introduction may be performed by completely inserting the renderable portion into the prediction loop to form new reference pictures with their own reference picture indices in addition to reference pictures obtained by the reconstructed version of the multi-view signal of the block-based prediction. Alternatively, the rendered portion may be introduced into the prediction loop completely, but with replacing the normal prediction reference signal, i.e., the normally reconstructed signal as obtained by block-based prediction. Alternatively, it may be signaled within the data stream which portions of the renderable portion are used to replace respective portions in the normally reconstructed signal.

Multi-view coding with exploitation of renderable portions

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

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Berlin, Germany

Heiko Schwarz