Ge Video Compression, LLC

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

Dolby Video Compression, LLC

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

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

Valeri George

Detlev Marpe

Heiner Kirchhoffer

Thomas Wiegand

Thomas Schierl

Benjamin Bross

Tung Nguyen

Mischa Siekmann

Jan Stegemann

Matthias Preiss

Anastasia Henkel

Robert Philipp Skupin

Karsten Grueneberg

Heiko Schwarz

Christian Bartnik

Tobias Hinz

Jens Brandenburg

Yago Sánchez De La Fuente

Karsten Grüneberg

Adam Wieckowski

Jackie Ma

Karsten Suehring

Christian Lehmann

Cornelius Hellge

Karsten Sühring

Karsten Gruneberg

Yago Sanchez De La Fuente

Santiago De Luxán Hernández

Gerhard Tech

Phan Hoang Tung Nguyen

Gayathri Venugopal

Thomas Weigand

The entropy coding of a current part of a predetermined entropy slice is based on, not only, the respective probability estimations of the predetermined entropy slice as adapted using the previously coded part of the predetermined entropy slice, but also probability estimations as used in the entropy coding of a spatially neighboring, in entropy slice order preceding entropy slice at a neighboring part thereof. Thereby, the probability estimations used in entropy coding are adapted to the actual symbol statistics more closely, thereby lowering the coding efficiency decrease normally caused by lower-delay concepts. Temporal interrelationships are exploited additionally or alternatively.

Sample array coding for low-delay

Sub-picture extraction is rendered less complex by providing each slice with start position information which indicates a starting position from which onwards the picture is, along a coding path, encoded into the respective slice, relative to an onset position at which the coding path starts traversing a segment the starting position is located in. Alternatively or additionally, sub-picture extraction processes are treated like choosing one layer out of a multi-layer datastream.

Efficient sub-picture extraction

An entropy decoder is configured to, for horizontal and vertical components of motion vector differences, derive a truncated unary code from the data stream using context-adaptive binary entropy decoding with exactly one context per bin position of the truncated unary code, which is common for horizontal and vertical components of the motion vector differences, and an Exp-Golomb code using a constant equi-probability bypass mode to obtain the binarizations of the motion vector differences. A desymbolizer is configured to debinarize the binarizations of the motion vector difference syntax elements to obtain integer values of the horizontal and vertical components of the motion vector differences. A reconstructor is configured to reconstruct a video based on the integer values of the horizontal and vertical components of the motion vector differences.

Entropy coding of motion vector differences

A decoder for decoding a data stream into which media data is coded has a mode switch configured to activate a low-complexity mode or a high-efficiency mode depending on the data stream, an entropy decoding engine configured to retrieve each symbol of a sequence of symbols by entropy decoding using a selected one of a plurality of entropy decoding schemes, a desymbolizer configured to desymbolize the sequence of symbols to obtain a sequence of syntax elements, a reconstructor configured to reconstruct the media data based on the sequence of syntax elements, selection depending on the activated low-complexity mode or the high-efficiency mode. In another aspect, a desymbolizer is configured to perform desymbolization such that the control parameter varies in accordance with the data stream at a first rate in case of the high-efficiency mode being activated and the control parameter is constant irrespective of the data stream or changes depending on the data stream, but at a second lower rate in case of the low-complexity mode being activated.

Entropy coding supporting mode switching

Scalable coding concepts are described. One aspect improves parallel decoding of inter-dependent layers of a multi-layer video data stream by introducing a long-term syntax element structure for guaranteeing that during a predetermined time period the pictures of the dependent layer are subdivided so that borders of the spatial segments of the pictures of the second layer and the spatial segments of the first layer overlay. Another aspect concerns upsampling from base layer to enhancement layer. Another aspect introduces a long-term syntax element structure allowing the decoder to determine the inter-layer offset for a predetermined time period. Another aspect introduces a type indicator field changing a way a layer indicator field within the NAL unit headers is to be interpreted. Another aspect allows different codecs/standards to be used for the different layers. Another aspect concerns a syntax element structure which indicates the inter-layer offset in units of the base layer blocks.

Efficient scalable coding concept

Video/picture coding of improved coding efficiency with supporting varying resolution and/or efficiently handling region-wise packing.

Picture/video coding supporting varying resolution and/or efficiently handling region-wise packing

The present invention concerns an apparatus configured to partition a picture into leaf blocks using recursive multi-tree partitioning, block-based encode the picture into a data stream using the partitioning of the picture into the leaf blocks, wherein the apparatus is configured to, in partitioning the picture into the leaf blocks, for a predetermined block which extends beyond a boundary of the picture, reduce an available set of split modes depending on a position at which the boundary of the picture crosses the predetermined block in order to obtain a reduced set of one or more split modes, wherein the apparatus is configured to signal a selected split mode in the data stream.

Apparatus and method for encoding and decoding a picture using picture boundary handling

Parallel processing concepts such as wavefront parallel processing, are realized with a reduced end-to-end delay by giving up the usual slice concept according to which slices are either coded/decoded completely independent from areas of the picture outside of the respective slice, or at least independent from areas outside the respective slice as far as the entropy coding is concerned, namely in favor of slices of different modes, namely ones called dependent slices which allow for interdependencies across slice boundaries, and others which do not, called normal slices, for example. Combined with the aspect or not, WPP processing concept is made more efficiently by using the slices' start syntax portions to locate WPP entry points.

Low delay picture coding

Video codec for supporting temporal inter-prediction, configured to perform padding of an area of a referenced portion of a reference picture which extends beyond a border of the reference picture, which referenced portion is referenced by an inter predicted block of a current picture by selecting one of a plurality of intra-prediction modes, and padding the area using the selected intra-prediction mode.

Apparatus for selecting an intra-prediction mode for padding

A video decoder for decoding an encoded video signal including encoded picture data and indication data of a picture of a video to reconstruct the picture of the video is provided. The video decoder includes an interface configured for receiving the encoded video signal, and a data decoder configured for reconstructing the picture of the video by decoding the encoded picture data using the indication data. The picture is partitioned into a plurality of coding areas. One or more coding areas of the plurality of coding areas include two or more coding tree units of the plurality of coding tree units, wherein each coding area of the one or more coding areas which includes two or more coding tree units exhibits a coding order for the two or more coding tree units of the coding area.

Encoder and decoder, encoding method and decoding method for versatile spatial partitioning of coded pictures

Decoder for decoding a picture, wherein blocks into which the picture is subdivided are assigned to a set of prediction types, which include intra prediction and inter prediction. For each of predetermined intra-predicted blocks, the decoder is configured to derive, from the data stream, an information on a partitioning of the respective predetermined intra-predicted block into partitions. The decoder is configured to derive, from the data stream, for each partition of the respective predetermined intra-predicted block, a partition-specific prediction residual signal related to a spatial domain prediction residual signal of the respective partition of the respective predetermined intra-predicted block via a predetermined transform. The predetermined transform can be identified out of a set of transforms including a first transform and a second transform, which equals a concatenation of a primary transform and a secondary transform applied onto a subset of coefficients of the primary transform.

Decoder, encoder and methods comprising a coding for intra subpartitions

A decoder includes an entropy decoder configured to derive a number of bins of the binarizations from the data stream using binary entropy decoding by selecting a context among different contexts and updating probability states associated with the different contexts, dependent on previously decoded portions of the data stream; a desymbolizer configured to debinarize the binarizations of the syntax elements to obtain integer values of the syntax elements; a reconstructor configured to reconstruct the video based on the integer values of the syntax elements using a quantization parameter, wherein the entropy decoder is configured to distinguish between 126 probability states and to initialize the probability states associated with the different contexts according to a linear equation of the quantization parameter, wherein the entropy decoder is configured to, for each of the different contexts, derive a slope and an offset of the linear equation from first and second four bit parts of a respective 8 bit initialization value.

Context initialization in entropy coding

A raw byte sequence payload describing a picture in slices, WPP substreams or tiles and coded using context-adaptive binary arithmetic coding is subdivided into tranches with continuing the context-adaptive binary arithmetic coding probability adaptation across tranche boundaries. Thereby, tranche boundaries additionally introduced within slices, WPP substreams or tiles do not lead to a reduction in the entropy coding efficiency of these entities. However, the tranches are smaller than the original slices, WPP substreams or tiles and accordingly they may be transmitted earlier, i.e. with lower delay, than the un-chopped original entities. According to another aspect combinable with the first aspect, substream marker NAL units are used within a sequence of NAL units of a video bitstream to enable a transport demultiplexer to assign data of slices within NAL units to the corresponding substreams or tiles so as to be able to, in parallel, serve a multi-threaded decoder with the corresponding substreams or tiles.

Coding concept allowing parallel processing, transport demultiplexer and video bitstream

Decoder for block-based decoding of a picture from a data stream, configured to decode an intra-coding mode for a predetermined block of the picture from the data stream, configured to decode a partition dimension flag for the predetermined block of the picture from the data stream and set a partition dimension depending on the partition dimension flag to be horizontal or vertical and the decoder is configured to partition, along the predetermined dimension, the predetermined block into transform partitions which are as wide as the predetermined block perpendicular to predetermined dimension, furthermore configured to decode, for each transform partition, a transform of a prediction residual from the data stream; intra-predicting the predetermined block depending on one or more already reconstructed samples neighboring the predetermined block in a manner depending on the intra-coding mode to obtain a predictor for the predetermined block; and reconstructing the predetermined block by correcting the predictor within each transform partition using the transform of the prediction residual decoded for the respective transform partition.

Implementation efficient partition-based intra coding concept

Decoder retrieval timing information, ROI information and tile identification information are conveyed within a video data stream at a level which allows for an easy access by network entities such as MANEs or decoder. In order to reach such a level, information of such types are conveyed within a video data stream by way of packets interspersed into packets of access units of a video data stream. In accordance with an embodiment, the interspersed packets are of a removable packet type, i.e. the removal of these interspersed packets maintains the decoder's ability to completely recover the video content conveyed via the video data stream.

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Berlin, Germany

Valeri George