A frame coding unit generates individual picture signal information from a moving picture signal, and outputs a frame code value which is a numeric value to be obtained as a result of coding picture signal information of each frame. A variable length coding unit decomposes the frame code value into unit frame code values which are basic units of coding, converts the unit frame code values into frame code words using only a single code table, and constructs a frame stream by combining the converted frame code words. A multiplexing unit multiplexes a header stream which is constructed through a method equivalent to a conventional method and the frame stream, and constructs a picture coded signal.

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 s.sub.i with 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 s.sub.i yields z, and, if n>1, for all i=1 . . . n1, the value of s.sub.i corresponds to a range of the i.sup.th partition.

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.

Methods and apparatus are provided for improved entropy encoding and decoding. An apparatus includes a video encoder (200) for encoding at least a block in a picture by transforming a residue of the block to obtain transform coefficients, quantizing the transform coefficients to obtain quantized transform coefficients, and entropy coding the quantized transform coefficients. The quantized transform coefficients are encoded using a flag to indicate that a current one of the quantized transform coefficients being processed is a last non-zero coefficient for the block having a value greater than or equal to a specified value.

The present invention provides arithmetic encoder and decoder, and methods implemented therein for termination of arithmetic coding. The arithmetic encoder first determines whether a bin value indicates termination of arithmetic encoding. If the bin value is determined not indicating termination of arithmetic encoding, no bit is written in a bitstream indicative of the bin value so determined. If the bin value is determined indicating termination of arithmetic encoding, a stop bit is written in the bitstream. The arithmetic decoder determines whether or not the end of a coded slice has been reached, based on a number of bits in the bitstream. More specifically, the arithmetic decoder makes a determination, based on a number of bits preceding a stop bit located in a last byte in the bitstream.

The present invention is a variable length coding method for coding coefficients in each block which are obtained by performing frequency transformation on picture data of a moving picture per block having a predetermined size, and comprises: a coefficient scanning step of scanning the coefficients in the block in a predetermined order; and a coding step of coding the coefficients scanned in the coefficient scanning step into variable length codes in a predetermined order by switching a plurality of tables to be used for coding. Here, a direction of switching between the tables may be one-directional. Also, the coding may be non-arithmetic coding.

The present invention is a variable length coding method for coding coefficients in each block which are obtained by performing frequency transformation on picture data of a moving picture per block having a predetermined size, and comprises: a coefficient scanning step of scanning the coefficients in the block in a predetermined order; and a coding step of coding the coefficients scanned in the coefficient scanning step into variable length codes in a predetermined order by switching a plurality of tables to be used for coding. Here, a direction of switching between the tables may be one-directional. Also, the coding may be non-arithmetic coding.

The transmission of broadcast data, such as financial data and news feeds, is accelerated over a communication channel using data compression and decompression to provide secure transmission and transparent multiplication of communication bandwidth, as well as reduce the latency. Broadcast data may include packets having fields. Encoders associated with particular fields may be selected to compress those particular fields.

The invention proposes a method and a device for arithmetic encoding of a current spectral coefficient using preceding spectral coefficients. Said preceding spectral coefficients are already encoded and both, said preceding and current spectral coefficients, are comprised in one or more quantized spectra resulting from quantizing time-frequency-transform of video, audio or speech signal sample values.

Said method comprises processing the preceding spectral coefficients, using the processed preceding spectral coefficients for determining a context class being one of at least two different context classes, using the determined context class and a mapping from the at least two different context classes to at least two different probability density functions for determining the probability density function, and arithmetic encoding the current spectral coefficient based on the determined probability density function wherein processing the preceding spectral coefficients comprises non-uniformly quantizing absolutes of the preceding spectral coefficients for use in determining of the context class.

An arithmetic encoder is provided for converting an event sequence comprised of a plurality of events to an information sequence comprised of at least one information piece, and includes a core engine for receiving an event of the event sequence, and a probability estimate from a probability estimator, and generating zero or more pieces of the information sequence responsive to the received event and the probability estimate by bounding the ratio of events to information pieces. An arithmetic encoder is provided that is capable of constraining a number of events in at least one event sequence as a function of the number of generated information pieces in at least one information sequence. An arithmetic decoder is provided for converting an information sequence comprised of at least one information piece to an event sequence comprised of a plurality of events, and includes a core engine for processing at least one information piece of the information sequence from the sequencer responsive to a probability estimate received from a probability estimator to generate at least one event by accounting for a bounded ratio of events to information pieces in the information sequence.