Abstract: An entropy encoder block for use in a context adaptive encoder and an entropy decoder block for use in a context adaptive decoder are provided.

Abstract: An entropy decoder and method for decoding code words with an indication of associated probability for each code word. The decoder may include an input buffer in communication with a branch node block, the branch node block in communication with a leaf node block. The input buffer operable to receive code words and the indication of associated probability. The branch node block comprising one or more branch node lookup tables and branch node control logic. The branch node control logic operable to process a code word in the input buffer using a selected table from the one or more branch node lookup tables to obtain leaf node information and a bit count of a code word size, the branch control logic further operable to refresh the input buffer to replace the bit count of the code word size and to make the leaf node information and the table selection available to the leaf node block. The leaf node block may include one or more leaf node lookup tables and leaf node control logic.

Abstract: A method and system for entropy coding can comprise, in response to detecting a first symbol combination comprising first run information indicating a first number of contiguous zero coefficients is greater than a cut-off-run value, assigning a first codeword to a first symbol combination, wherein the first codeword comprises an escape code from a first-level VLC table; and in response to a second symbol combination comprising second run information indicating a second number of contiguous zero coefficients is less than or equal to the cut-off-run value, assigning a second codeword to the second symbol combination, wherein the second codeword is from the first-level VLC table. The system and method can further comprise collecting coding statistics for a set of candidate symbol combinations and adjusting a mapping between codewords of the first-level VLC table and a subset of the set of candidate symbol combinations based on the coding statistics.

Abstract: Techniques and tools for encoding and decoding data values that are hierarchically organized are presented. For example, an encoder encodes data as a set that has a hierarchy of subsets with set symbols. In the encoding, the encoder evaluates the data values of the set and selectively encodes a symbol combination code that indicates the set symbols of multiple subsets of the set. Then, for each of the multiple subsets considered as a new set, the encoder selectively repeats the evaluating, selective encoding and selective repetition for the new set. In corresponding decoding, a decoder decodes data encoded as a set that has a hierarchy of subsets with set symbols. In some implementations, the encoding and decoding are adaptive and use a symbol alphabet with nested elements.

Abstract: A variable length data storage device enables clearly and quickly determining where there are breaks in variable length data even when such data is stored without gaps in a stored data file. A variable length data storage step stores variable length items, each containing variable length data including at the beginning the length of such data, without gaps in a stored data file. A marker management item registration step registers marker management items, each containing a break marker and the storage location of the variable length data corresponding to the break marker, in a marker management file. A marker identifier management item registration step registers marker identifier management items, each including a marker identifier composed of a predetermined number of characters from the beginning of the text string used as the break marker and the storage location of the break marker, in a marker management memory area.

Abstract: Arithmetic coding utilizes probability values associated with contexts and context indexed values. The probability values are stored within a random access memory 6 from where they are fetched to a cache memory 8 before being supplied to an arithmetic encoder and decoder 4. The context indexed values used are mapped to the plurality of contexts employed such that context indexed values used to process data values close by in a position within the stream of data values being processed have a greater statistical likelihood of sharing a group of contexts than context values used to process data values far away in position within the stream of data values. Thus, a group of contexts for which the probability values are fetched together into the cache memory 8 will have an increased statistical likelihood of being used together in close proximity in processing the stream of data values. This reduces the number of cache flush operations and cache line fill operations.

Abstract: Method and apparatus for variable length code (VLC) encoding is described. In some examples, a symbol of frequency transform values having a run and a level is VLC encoded. An address is generated, at a processor, for a lookup table (LUT) in a memory based on the run and the level, the LUT storing VLC entries for all possible combinations of run values ranging from minimum to maximum runs and level values ranging from minimum to maximum levels, each of the VLC entries including a flag indicative of an escape mode. A VLC entry is read from the LUT using the address. A VLC code and bit length are obtained from the VLC entry if the flag in the VLC entry is a first value. A fixed length VLC code is generated from an escape code, the run, and the level if the flag in the VLC entry is a second value.

Abstract: Provided are a computer program product, system, method, and data structure for using variable length code tables to compress an input data stream to a compressed output data stream. A determination is made as to whether a number of at least two consecutive data units in the input data stream match the number of consecutive data units in a history buffer of previously received data units in the input data stream. If so, a copy pointer symbol is generated including data indicating a copy pointer symbol referencing previously received data units in the history buffer and indicating the determined number of consecutive data units. A determination is made of a relative displacement count in the history buffer at which the number of matching consecutive data units start. A determination is made from a variable length code table an encoding of the relative displacement count in the history buffer.

Abstract: Provided are a computer program product, system, method, and data structure for using variable length code tables to compress an input data stream to a compressed output data stream. If a number of consecutive data units in the input data stream match the number of consecutive data units in a history buffer of previously received data units in the input data stream, a copy pointer symbol is generated indicating the copy pointer symbol referencing previously received data units in the history buffer and indicating a location of a start of the consecutive data units in the history buffer. A determination is made from a variable length code table of an encoding of the number. Indication is made in the generated copy pointer symbol the determined encoding of the number and the copy pointer symbol is outputted in the compressed output data stream.

Abstract: This application relates to decoding signals that carry clock and data information. In particular, it relates to construction a time-varying histogram of inter-arrival times between pulse edges and using the histogram to identify whether a pulse edge encodes a single length interval, a double length interval or some longer length interval. Further details and embodiments of the technology disclosed are provided in the drawings, detailed description and claims.

Abstract: The disclosure relates to variable length encoding and decoding. A symbol is variable length encoded by selecting a variable length code word table from a set of variable length code word tables based on a value of a variable; selecting a code word from the selected variable length code word table on the basis of said symbol; and updating the value of said variable by comparing the correspondence between said symbol and said variable. If the comparison indicates that the value of the variable is smaller than the symbol, the value of said variable is incremented; else if the comparison indicates that the value of the variable is greater than the symbol, the value of said variable is decremented; else the value of the variable is not amended.

Abstract: A method of transmitting a control channel format indicator (CCFI), also known as PCFICH (Physical Control Format Indicator Channel), in case where the length of a coded CCFI is not an integer multiple of three, including mapping a plurality of two-bit CCFI into a codebook with each component codeword having three bits; generating a sequence of codewords selected from the codebook by repeating the selected component codeword for predetermined times; generating a codeword by concatenating the sequence of the selected component codewords with the original CCFI bits; and transmitting the codeword carrying information of CCFI. The method further includes a step of generating a permutation of each of the four codewords by assigning K repetitions of the three-bit component codeword to the number of K resource units respectively and mapping remaining K bits of each of the four codewords separately to the number of K resource units.

Abstract: A variable-length code decoding apparatus has a first table storing part capable of converting the variable-length codes into first decoded data comprising successive zeros, a second table storing part capable of converting a variable-length code and for which corresponding decoded data comprises no zeros, a third table storing part capable of converting a variable-length code comprising a code length of N and for which corresponding decoded data comprises no zeros or capable of converting a combination of the variable-length codes, a bit shifting part configured to shift the input bitstream by a specific number of bits, a fourth table storing part capable of converting a variable-length code at a header of the bit-shifted input bitstream into fourth decoded data, a combining part configured to combine the second or the third decoded data and the fourth decoded data.

Abstract: Variable length code decoding device for decoding variable length code data, including: decoding process tables each including at least two kinds of formats consisting a first format storing identification information for designating a subsequent table to be referred to in a subsequent decoding process, and a second format that stores a decoded value obtained by repeating the decoding process and a significant bit length to be referred to with respect to variable length code data. The device utilizes first, second, third and fourth formats and relative addresses.

Abstract: Provided is a method for generating codewords. The method comprises the following steps: receiving an information bit; generating a generating matrix in which a size of a column is identical with a length of the information bit, a size of a row is 24 rows, and values of symbols that are elements of the matrix are 0 or 1; modifying the generating matrix by dividing the generated generating matrix into an upper group and a lower group having an identical size and replacing rows so that the number of symbols having a value of 1 in the upper group is identical with the number of symbols having a value of 1 in the lower group; and obtaining inner products from the information bit and each row of the modified generating matrix and generating codewords from remainders obtained by dividing the inner products by 2.

Abstract: A variable-length code decoding apparatus has a first-table storing part to store a first table, a second-table storing part to store a second table, a priority determining part to read out by priority a combination of zero information that is stored in the second table and corresponds a combination of variable-length codes having the largest number of codes, whereas if variable-length codes included in the input bitstream is not stored in the second table but stored in the first table, to read out zero information, and a decoding part to generate the decoded data based on the zero information or the combination of zero information read out by the priority determining part.

Abstract: A specially programmed computer encodes repeating sequences of equidistant-spaced bit series that are identified in an input file. The position of each sequence is encoded relative to one or more instances of the previous sequence, including both the spacing between bits and the bit position of identified portions of each. For a certain class of input files, this encoding of repeating sequences significantly compresses the input file into the output file. A specially programmed computer decodes files that have been encoded in this manner.

Abstract: Systems, methods, and apparatus for a scalable processor architecture for variety of string processing application are described. In one such apparatus, n input first in, first out (FIFO) buffer stores an input stream. A plurality of memory banks store data from the input stream. A re-configurable controller processes the input stream. And an output FIFO buffer stores the processed input stream.

Abstract: Waveforms are digitally sampled and compressed for storage in memory. The compression of the data includes generating a truncated entropy encoding map and using the values within the map to obtain good compression. An encoder further sub-selects values to be encoded and values to remain unencoded to provide an overall compression of the data.

Abstract: A plurality of segments of the sequence are identified, wherein a segment of the plurality of segments includes at least one unsigned integer of the unsigned integer data, and wherein the plurality of segments are based in part on context within the sequence. The plurality of segments are coded, wherein each segment of the plurality of segments is coded using a different coding alphabet, wherein a coding alphabet is constrained at least by unsigned integers of a corresponding segment.

Abstract: A table device includes a match cell number output unit 25 for outputting a match cell number showing a cell PE which outputs a matching signal, and an address decoder 26 for specifying a node from among nodes in a search tree which construct a conversion table, the node corresponding to the match cell number. The table device acquires a data conversion value assigned to the above-mentioned node from a configuration memory 21, and, when the data conversion value is data showing a coded result or the like, outputs the data conversion value to outside the table device, whereas when the data conversion value is a branch code of the search tree, updates the cell PE to which a comparison instruction signal is furnished.

Abstract: The method includes the following units: a coefficient number detecting unit (109) for detecting the number of coefficients which has a value other than 0 for each block according to the generated coefficient, a coefficient number storing unit (110) for storing the number of coefficients detected, a coefficient number coding unit (111) for selecting a table for variable length coding based on the numbers of coefficients in the coded blocks located on the periphery of a current block to be coded with reference to the selected table for variable length coding so as to perform variable length coding for the number of coefficients.

Abstract: A method for storing node information of a Huffman tree. The method creates an index of each node in the Huffman tree using a breadth first search (BFS) algorithm. The method further reads each node of the Huffman tree beginning from a root node according to a sequence of the index of each node, and stores node information of each node into an array of the Huffman tree.

Abstract: A variable-length encoder that feeds a Coded Block Pattern (CBP) as an input symbol to variable-length code output part. Coded symbol memory supplies CBPs in neighboring blocks as coding map table reference information to coding map table provider. Coding map table provider determines a coding map table used in coding of the CBP, based on these CBPs in the neighboring blocks, and provides a coding map table H4 to variable-length code output part. Variable-length coding table provider feeds a variable-length coding table to variable-length code output part. Then the coding target CBP is subjected to variable-length coding, and the resultant is outputted as coded data. This allows information source coding of coding symbols to be performed efficiently according to the coding condition and the property of image.

Abstract: A variable length code decoding device for decoding variable length code data, including: a table memory that stores a plurality of decoding process tables having a reference relationship therein; and a decoding control unit that sequentially selects the decoding process tables according to the decoded data to control a process of decoding the variable length code data, wherein when referring to the decoding process table to perform an initial decoding of the variable length code data, the initial decoding process is conducted by a longer bit length to be clipped from the variable length code data for referring to the decoding process table than the bit length used when referring to the other portions of the decoding process table.

Abstract: The method includes the following units: a coefficient number detecting unit (109) for detecting the number of coefficients which has a value other than 0 for each block according to the generated coefficient, a coefficient number storing unit (110) for storing the number of coefficients detected, a coefficient number coding unit (111) for selecting a table for variable length coding based on the numbers of coefficients in the coded blocks located on the periphery of a current block to be coded with reference to the selected table for variable length coding so as to perform variable length coding for the number of coefficients.

Abstract: An optimized method and system for entropy coding is described. The system may include an input module to receive a digital image, a Discrete Cosine Transform (DCT) module to obtain a plurality of DCT coefficients associated with the digital image, a statistics generator to generate statistics associated with the plurality of DCT coefficients, a placement module to store the generated statistics in the plurality of DCT coefficients and entropy coder to generate uniquely decodable (UD) codes for the plurality of DCT coefficients. The entropy coder may utilize the statistics stored in the plurality of DCT coefficients.

Abstract: An encoding apparatus includes a unit that calculates a plurality of normalized values by dividing input values in an input signal by either a normalization coefficient that is closest to a maximum value of absolute values of the input values or a normalization coefficient that is closest to the maximum value from among normalization coefficients that are larger than the maximum value; a unit that generates a plurality of quantized values by quantizing the plurality of normalized values; a unit that stores a code table in which the smaller the probability of occurrence of the plurality of quantized values, the longer the code length of a variable-length code allocated to the plurality of quantized values; and a unit that outputs, when the plurality of quantized values are all zero, a variable-length code allocated to a combination of a plurality of quantized values in accordance with the code table.

Abstract: A variable-length code decoding apparatus that decodes a bitstream includes: a storage unit that stores a variable-length code table; a bitstream cutout unit that outputs a bit string of a fixed length; a reference unit that outputs decoded data and a code length with reference to the storage unit; a determination unit that determines whether a bit string of the fixed length is accumulated; a determination unit that determines whether a bit string of a length that is shorter than the fixed length is accumulated; and a selection unit that selects one of the determination results from the determination units. The bitstream cutout unit sets a starting bit based on the selected determination result, and the selection unit switches the selection of the determination results from the determination units.

Abstract: A system to compress an inter-system channel data stream may include a data compression application executing via a computer processor. The system may additionally include a transmit dictionary used by said data compression application to compress an inter-system channel data stream. The system may also include a data decompression application executing via a second computer processor to decompress the inter-system channel data stream. The system may further include a receive dictionary used by said data decompression application to decompress the inter-system channel data stream.

Abstract: In one embodiment, a protection control monitoring device includes a conversion unit sequentially converting analog data corresponding to an amount of electricity of a power system into digital data and outputting the results as a data sequence, a calculation unit sequentially calculating difference data representing a difference between adjacent data in the data sequence and outputting results as a difference data sequence, a data block generation unit dividing each of a plurality of difference data in the difference data sequence into a plurality of partial data, generating data blocks from a plurality of corresponding partial data, and outputting results as a data block sequence, a compression unit losslessly compressing the data block sequence, and a storage unit storing the losslessly compressed data block sequence.

Abstract: Methods and apparatus for iteratively encoding a portion of a signal are described in which the portion of the signal is quantised and an output bit count is estimated based on the sum of logarithms to base n of values of each sample in the plurality of quantised samples and the total number of samples. The output bit count corresponds to an estimate of the output bit count for the portion of the signal once encoded using a code, such as a Huffman code.

Abstract: In one example, this disclosure describes a method of codeword adaptation for variable length coding. The method comprises applying a first codeword adaptation scheme to a first group of codewords of a variable length coding (VLC) table to change a mapping of codewords to events in the VLC table; and applying a second codeword adaptation scheme to a second group of codewords of the VLC table to change the mapping of the codewords to the events in the VLC table.

Abstract: In one example, this disclosure describes a method of codeword adaptation for variable length coding. The method includes applying a first codeword adaptation scheme to groups of codewords in a variable length coding (VLC) table to change mappings of codewords within the groups to events in the VLC table; and applying a second codeword adaptation scheme to individual codewords within the groups of codewords in the VLC table to change mappings of the codewords to the events within the groups in the VLC table.

Abstract: Methods and apparatus are provided to allow Internet Key Exchange (IKE) phase 1 keying materials to be periodically refreshed in a secure manner without requiring user interaction. A client and server perform authentication and key exchange during set up of a secure connection. A token is passed to the client by the server during or after the initial user authentication phase. The token is stored both at the client and at the server. Instead of requiring user credentials, the token can be used to securely prove the identity of the client.

Abstract: In a data encoding process: data is encoded by using unit bit series obtained from an encoding bit series; the encoding bit series is searched for a first bit series identical to a portion of the encoded data; the portion is substituted with a second bit series which includes a leading code indicating a leading position of a substitution range and position information indicating the position of the first bit series in the encoding bit series. In a data decoding process: the position information is detected from the substitution range in received data after the leading code is detected in the data; a substitution bit series is extracted from the position in the encoding bit series indicated by the position information; and the data in the substitution range is substituted with the substitution bit series so as to restore the encoded data.

Abstract: A method and apparatus for generating and transmitting codewords is provided. The method includes receiving information bits with a variable length, selecting vectors by the length of the information bits from a generator matrix, and generating a codeword based on the information bits and the generator matrix. Codewords with a certain length providing a coding performance with respect to received variable information bits can be obtained.

Abstract: A data modulation apparatus includes: insertion means for inserting information bits into data at a predetermined interval; conversion means for converting the data into which the information bits are inserted into an RLL code based on a modulation table that has a variable-length conversion rule; setting means for setting a control section that is used for calculating a value of the information bit; and determination means for determining the value of the information bit inserted into the control section that is different from a calculation target by calculating the code of the control section.

Abstract: A variable length data storage device enables clearly and quickly determining where there are breaks in variable length data even when the variable length data is stored without gaps therebetween in a stored data file. A variable length data storage step (S509) stores a plurality of variable length items, each containing variable length data including at the beginning the data length of the variable length data, without gaps therebetween in a stored data file. A marker management item registration step (step S510) registers a plurality of marker management items, each containing a break marker and the storage location of the variable length data corresponding to the break marker, in a marker management file.

Abstract: An integer value sequence is used as an input, and [1] codes corresponding to integers (referred to as specified integers) and [2] codes (referred to as extension codes) corresponding to sets of a plurality of integers other than the specified integers are previously determined. Coding is performed in such a manner that the code corresponding to the specified integer is adopted as the result of the coding if an integer value to be coded in the integer value sequence is the specified integer, and a code obtained by combining the extension code and a code obtained by applying a predetermined coding method corresponding to the extension code to the integer value to be coded is adopted as the result of the coding if the integer value to be coded in the integer value sequence is not the specified integer.

Abstract: A compression engine starts compressing data by a preset first compression rule, compresses the following data by a second compression rule when the characteristics of the data satisfy a predetermined switching condition, and returns to the first compression rule when the characteristics of the data do not satisfy the switching condition to compress the data and the following data. A decompression engine starts decompressing compressed data by a first decompression rule corresponding to the first compression rule, decompresses the following compressed data by a second decompression rule corresponding to the second compression rule when the characteristics of the data after decompression satisfy the switching condition, and returns to the first decompression rule when the characteristics of the data after decompression do not satisfy the switching condition to decompress the data and the following compressed data.

Abstract: An image processing apparatus and an image processing method that reduce data transmission time by transmitting data between internal memories of a codec without passing through a system memory. Reducing the number of accesses to the system memory increases processing speed, and reduces the load of a main processor, when image data is to be encoded or decoded.

Abstract: A first video signal processor (103) receives a first encoded video signal from which a video unit (201) generates a second encoded video signal, where the second encoded video signal is a reduced data rate version of the first encoded video signal. An error encoder (203) generates error redundancy data for the second encoded video signal and a multiplexer (207) generates output video data comprising the first encoded video signal and the error correcting data but not comprising the second encoded video signal. A second video processor (105) receives the output video data and a video unit (303) regenerates the second video signal from the first video signal. An error unit (305) detects errors for at least a first segment of the second video signal in response to the error redundancy data. A combiner (307) then generates combined video data by combining corresponding segments of the first encoded video signal and the second encoded video signal.

Abstract: The invention relates to a fractional bit encoder (1) and a method for encoding a data stream into code word identifiers for a physical line encoder (13), wherein said fractional bit encoder (1) comprises a (1:K) demultiplexer (3) for a de-multiplexing a received data stream into a predetermined number (K) of bit streams, a first (K1:n) multiplexer (4) for re-multiplexing a first number (K1) of said K bit streams onto n parallel lines transporting n re-multiplexed bit streams and a second multiplexer (5) re-multiplexing a second number (K2) of said K bit streams (K2:1) onto a single line transporting one further re-multiplexed bit stream, wherein n=[ld(M)] and M being a configurable number of different code word identifiers, a class detector (7) which evaluates the first n re-multiplexed bit streams to determine a class of the respective bit combination and a word encoder (10) which encodes the respective bit combination depending on the determined class of the bit combination.

Abstract: A method for assigning codes to Huffman trees and repairing invalid Huffman trees is disclosed using a calculated delta and moving nodes within the Huffman tree by adjusting their encode register entries.

Abstract: The present disclosure includes apparatus, systems and techniques relating to pipelined processing. In some implementations, a method performed by a data processing device includes storing data in a memory module. The method includes processing the stored data in accordance with a compression algorithm to produce processed data. Processing the stored data includes pipelined processing of a defined number of symbols of the stored data in parallel, and discarding results of the pipelined processing that are rendered invalid by other results of the pipelined processing. Additionally, the method includes outputting the processed data.

Abstract: The invention is made in the technical field of encoding and decoding of bit sequences. The invention proposes a device for compression-encoding an input bit sequence in which Zeroes and Ones occur equally frequent, comprising an XOR gate adapted for receiving pairs of immediately succeeding bits of the input bit sequence as inputs and for outputting further bits of another bit sequence, means for adding a bit to said other bit sequence wherein the added bit is a primary bit which is equal to a primary bit of the input bit sequence or a last bit which is equal to a last bit of the input bit sequence, and means for encoding the other sequence. The XOR gate transforms the input bit sequence into the other bit sequence which comprises more uneven frequencies of occurrence of Zeroes and Ones than the input bit sequence.

Abstract: Systems, methods, and physical computer-readable storage media for performing geometric data compression and geometric data decompression and/or geometric data encryption and geometric data decryption. A virtual geometric compression object is generated within a computer system by defining a plurality of discrete elements arranged in a geometric shape and assigning one or more data bit values to each of the plurality of discrete elements. The virtual geometric compression object is used by the computer system to compress sequences of uncompressed data bits into compression definitions. A compression definition defines a path through the virtual geometric compression object corresponding to a sequence of uncompressed data bits. In a reverse manner, for data decompression, at least a portion of a virtual geometric compression object is generated and a compression definition is used to extract a corresponding sequence of uncompressed data bits from the portion of the virtual geometric compression object.

Abstract: Provided is an encoding apparatus including: a determination unit which determines bit allocation at the time of quantizing a data signal based on normalization information of the data signal so that a data length as a result of fixed length encoding of the quantized data signal becomes close to a second data length which is equal to or larger than a first data length allocated to a result of variable length encoding of the quantized data signal; a quantizer which quantizes the data signal based on the bit allocation; and an encoder which performs variable length encoding on the quantized data signal, wherein the determination unit updates the second data length so that a difference between a data length of the variable-length-encoded data signal and the first data length is within a predetermined range.

Abstract: A method of transmitting a control channel format indicator (CCFI), also known as PCFICH (Physical Control Format Indicator Channel), in case where the length of a coded CCFI is not an integer multiple of three, including mapping a plurality of two-bit CCFI into a codebook with each component codeword having three bits; generating a sequence of codewords selected from the codebook by repeating the selected component codeword for predetermined times; generating a codeword by concatenating the sequence of the selected component codewords with the original CCFI bits; and transmitting the codeword carrying information of CCFI. The method further includes a step of generating a permutation of each of the four codewords by assigning K repetitions of the three-bit component codeword to the number of K resource units respectively and mapping remaining K bits of each of the four codewords separately to the number of K resource units.