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

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

Christian Rudat

Thomas Wiegand

Detlev Marpe

Heiko Schwarz

Heiner Kirchhoffer

Phan Hoang Tung Nguyen

Mischa Siekmann

Paul Haase

Martin Winken

Jonathan Pfaff

Benjamin Bross

A video encoder is configured to entropy encode an absolute value of a quantization level of a current transform coefficient at position (xC, yC), wherein the absolute value is encoded using context adaptive binary arithmetic encoding of bins of a first binarization. The video coder is further configured, for the current transform coefficient, to encode a bin of the first binarization by using a context which is determined based on a sum of minimum absolute values of transform coefficient quantization levels, based on encoded bins of the first binarization, at one or more transform coefficient positions among (xC+1, yC), (xC+2, yC), (xC+1, yC+1), (xC, yC+1), and (xC, yC+2).

Transform coefficient block coding

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

Arithmetic encoder for encoding a plurality of symbols is configured to derive an interval size information for an arithmetic encoding of one or more symbol values to be encoded on the basis of one or more state variable value, in a first mode of operation, and to update the one or more state variable values and/or the interval size information for an encoding of one or more subsequent symbol values to be encoded in the first mode; in a second mode, the arithmetic encoder is configured to disable an update of the one or more state variable values and/or of the interval size information. Additionally, further embodiments of arithmetic encoders and decoders and video encoders and decoders are described.

Arithmetic encoders and decoders, video encoders and decoders, methods for encoding or decoding symbols, and methods for encoding or decoding video content

An encoder encodes transform coefficients of a transform coefficient block representing a block of a picture using a scan pattern which sequentially traverses the transform coefficients of the transform block by encoding absolute values of quantization levels of the transform coefficients. The absolute values are binarized with a binarization comprising a first part of the binarization below a cutoff value and a second part of the binarization, prefixed by a codeword of the first part of the binarization for the cutoff value, above the cutoff value. The encoder adaptively, based on previously encoded transform coefficients, decreases the cutoff value to zero monotonically during encoding of the transform coefficients so that the binarization comprises the second part of the binarization and not the first part of the binarization.

A video decoder decodes a first indication () indicating whether transform coefficients of a first transform coefficient block () corresponding to a first color component are encoded into a data stream. The decoder also decodes a second indication () indicating whether transform coefficients of a second transform coefficient block () corresponding to a second color component are encoded into the data stream using context-adaptive entropy decoding with a context selected based on the first indication for the first transform coefficient block (). The decoder further derives a block () of the picture by, separately for the first color component and the second color component, a reverse transformation of the first transform coefficient block (and the second transform block (, respectively.

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Berlin, Germany

Christian Rudat