Fraunhofer-Gesellschaft Zur Foerderung Der Angewandten Forschung E.V.

Paul Haase

Thomas Wiegand

Detlev Marpe

Heiko Schwarz

Heiner Kirchhoffer

Phan Hoang Tung Nguyen

Mischa Siekmann

Christian Rudat

Jan Stegemann

Christian Bartnik

Stefan Matlage

Karsten Mueller

Karsten Müller

Soenke Schmidt

An encoding scheme for encoding a sequence of integer values comprises encoding a value at a predetermined position and then consecutively calculating and encoding differences between neighboring values. A respective decoding scheme is also provided. These encoding and decoding schemes provide a more efficient encoding concept.

Apparatuses for encoding and decoding a sequence of integer values, methods for encoding and decoding a sequence of integer values and computer program for implementing these methods

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

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 decoder configured to decode residual levels, and sequentially dequantize the residual levels by selecting a quantizer out of a set of default quantizers depending on a current transition state, and updating the current transition state depending on a current residual level's characteristic obtained by an application of a binary function onto the current residual level, and depending on a quantization mode information contained in the data stream. The current transition state transitions, according to a surjective mapping which depends on the quantization mode information, from a domain of combinations of a set of one or more transition states with the current residual level's characteristic onto the set of one or more transition states, wherein a cardinality of the set of one or more transition states differs depending on the quantization mode information.

Decoder, encoder and method for supporting adaptive dependent quantization of transform coefficient levels

An arithmetic encoder for encoding a plurality of symbols having symbol values is configured to derive an interval size information for an arithmetic encoding of one or more symbol values to be encoded based on a plurality of state variable values representing statistics of a plurality of previously encoded symbol values with different adaptation time constants. The arithmetic encoder is configured to map a first state variable value, or a scaled and/or rounded version thereof, using a lookup-table and to map a second state variable value, or a scaled and/or rounded version thereof using the lookup-table, in order to obtain the interval size information describing an interval size for the arithmetic encoding of one or more symbols to be encoded. Further arithmetic encoders, arithmetic decoders, video encoders, video decoder, methods for encoding, methods for decoding and computer programs are also disclosed which are based on the same concept and on other concepts.

Arithmetic encoders, arithmetic decoders, video encoder, video decoder, methods for encoding, methods for decoding and computer program

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

Paul Haase