Abstract: A subblock-based coding of transform coefficient blocks of the enhancement layer is rendered more efficient. To this end, the subblock subdivision of the respective transform coefficient block is controlled on the basis of the base layer residual signal or the base layer signal. In particular, by exploiting the respective base layer hint, the subblocks may be made longer along a spatial frequency axis transverse to edge extensions observable from the base layer residual signal or the base layer signal.

Abstract: 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.

Abstract: The coding efficiency of scalable video coding is increased by substituting missing spatial intra prediction parameter candidates in a spatial neighborhood of a current block of the enhancement layer by use of intra prediction parameters of a co-located block of the base layer signal. By this measure, the coding efficiency for coding the spatial intra prediction parameters is increased due to the improved prediction quality of the set of intra prediction parameters of the enhancement layer, or, more precisely stated, the increased likelihood, that appropriate predictors for the intra prediction parameters for an intra predicted block of the enhancement layer are available thereby increasing the likelihood that the signaling of the intra prediction parameter of the respective enhancement layer block may be performed, on average, with less bits.

Abstract: Apparatus for decoding a predetermined block (18) of a picture using intra-prediction, configured to read, from the data stream (12), a mode index (200), the mode index pointing to one out of a list (204) of matrix-based intra-prediction modes. Additionally, the apparatus is configured to predict samples (108) of the predetermined block (18) by computing a matrix-vector product (206) between an input vector (102) derived from reference samples (17) in a neighborhood of the predetermined block (18) and a prediction matrix (19) associated with the matrix-based intra-prediction mode (k) pointed to by the mode index (200) and associating components (210) of an output vector (208) obtained by the matrix vector product (206) onto sample positions (104) of the predetermined block.

Abstract: 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.

Abstract: Scalable video coding is rendered more efficient by deriving/selecting a subblock subdivision to be used for enhancement layer prediction, among a set of possible subblock subdivisions of an enhancement layer block by evaluating the spatial variation of the base layer coding parameters over the base layer signal. By this measure, less of the signalization overhead has to be spent on signaling this subblock subdivision within the enhancement layer data stream, if any. The subblock subdivision thus selected may be used in predictively coding/decoding the enhancement layer signal.

Abstract: 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 initial

Abstract: 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.

Abstract: 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.

Abstract: Scalable video coding is rendered more efficient by deriving/selecting a subblock subdivision to be used for enhancement layer prediction, among a set of possible subblock subdivisions of an enhancement layer block by evaluating the spatial variation of the base layer coding parameters over the base layer signal. By this measure, less of the signalization overhead has to be spent on signaling this subblock subdivision within the enhancement layer data stream, if any. The subblock subdivision thus selected may be used in predictively coding/decoding the enhancement layer signal.

Abstract: In accordance with a first aspect, an improved compression efficiency is achieved by letting a block-wise picture codec support a set of intra-prediction modes according to which the intra-prediction signal for a current block of a picture is determined by applying a set of neighboring samples of the current block onto a neural network. A second aspect of the present application is that, additionally or alternatively to the spending of neural network-based intra-prediction modes, the mode selection may be rendered more effective by the usage of a neural network dedicated to determine a rank or a probability value for each of the set of intra-prediction modes by applying a set of neighboring samples thereonto with the rank or probability value being used for the selection of one intra-prediction mode out of the plurality of intra-prediction modes including or coinciding with the set of intra-prediction modes.

Abstract: An apparatus for determining visual activity information for a predetermined picture block of a video sequence including a plurality of video frames, the plurality of video frames including a current video frame and one or more timely-preceding video frames, wherein the one or more timely-preceding video frames precede the current video frame in time, is provided. The apparatus is configured to receive the predetermined picture block of each of the one or more timely-preceding video frames and the predetermined picture block of the current video frame. Moreover, the apparatus is configured to determine the visual activity information depending on the predetermined picture block of the current video frame and depending on the predetermined picture block of each of the one or more timely-preceding video frames and depending on a temporal high-pass filter.

Abstract: A video coding method and apparatus for codes a video in a data stream using block-based predictive coding by deriving a collection of one or more primitive predictions for a block using a set of primitive prediction modes adapted for predicting blocks of a picture of the video. Each primitive prediction in the collection of primitive predictions is derived using a respective primitive prediction mode from the set of primitive prediction modes. A composite prediction signal for the block is composed by combining primitive predictions from the collection of one or more primitive predictions, and the block is predicted using the composite prediction signal.

Abstract: 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.

Abstract: In accordance with a first aspect, an improved compression efficiency is achieved by letting a block-wise picture codec support a set of intra-prediction modes according to which the intra-prediction signal for a current block of a picture is determined by applying a set of neighboring samples of the current block onto a neural network. A second aspect of the present application is that, additionally or alternatively to the spending of neural network-based intra-prediction modes, the mode selection may be rendered more effective by the usage of a neural network dedicated to determine a rank or a probability value for each of the set of intra-prediction modes by applying a set of neighboring samples thereonto with the rank or probability value being used for the selection of one intra-prediction mode out of the plurality of intra-prediction modes including or coinciding with the set of intra-prediction modes.

Abstract: 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.

Abstract: A decoder is described, which receives an encoded data stream. The encoded data stream includes data representing a picture and a classification mode parameter. The classification mode parameter specifies a certain classification to be applied to samples in the picture, the certain classification selected from a plurality of classifications. The decoder decodes the encoded data stream to obtain a reconstructed picture and the classification mode parameter, classifies samples of the reconstructed picture into one of a plurality of classes using the certain classification specified by the classification mode parameter, and filters the samples of the reconstructed picture. A sample is filtered using a filter for the class into which the sample has been classified.

Abstract: A video encoder encodes a video into a data stream, the video encoder being configured to vary a granularity at which a Quantization Parameter—QP—is applied depending on an association of frames of the video to temporally hierarchical layers at which the video is encoded into the data stream. The technology also concerns a respective decoder, a respective method for encoding and decoding, and a computer program for implementing the methods.

Abstract: 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.

Abstract: A video decoder for decoding a video from a data stream using block-based predictive decoding, the video decoder supporting a set of primitive prediction modes for predicting blocks of a picture of the video, is configured to predict a predetermined block by a composed prediction signal by deriving, using a collection of one or more primitive prediction modes out of the set of primitive prediction modes, a collection of one or more primitive predictions for the predetermined block, and composing the composed prediction signal for the predetermined block by combining the collection of one or more primitive predictions.