Abstract: A method for encoding an input sequence of symbols to produce a bitstream and a method of decoding the bitstream to generate a reconstructed binary sequence. Encoding employs an encoding tree having primary codewords associated with leaf nodes and secondary codewords associated with internal nodes. A flush event may cause output of secondary codewords. A context model is used to select an encoding tree corresponding to an estimated probability at the encoder. The same context model is used by the decoder to select a decoding tree. The decoder interleaves bits from decoded bit sequences associated with different estimated probabilities based on the context model.

Abstract: A system and method combine an entropy coding algorithm like Huffman or arithmetic coding with a fixed length coding scheme and can improve the compression performance in a fixed rate compression scheme. The fixed length code assigns codes with a fixed length to symbols that have the highest probability of occurrence. Therefore, fixed length coding is used if all symbols in the sequence are from the set of symbols that have the highest probability values. Otherwise an entropy coding algorithm (e.g. Huffman coding) is used to encode quantized symbols.

Abstract: A system and method that process encoded data, wherein the encoded data is an encoded video stream. The encoded data may be buffered and the characteristics of the buffered encoded data may be determined and used to select a decoding table from a plurality of decoding tables. An encoded word may then be decoded using the selected decoding table. The output of the decoding table may be the corresponding decoded word and the size of the encoded word. The size of the encoded word may be utilized to shift the buffered encoded data. The decoded word may be sent to the appropriate portion of the system.

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: A system and method of selecting a predefined Huffman dictionary from a bank of dictionaries. The dictionary selection mechanism of the present invention effectively breaks the built-in tradeoff between compression ratio and compression rate for both hardware and software compression implementations. A mechanism is provided for automatically creating a predefined Huffman dictionary for a set of input files. The dictionary selection mechanism achieves high compression rate and ratio leveraging predefined Huffman dictionaries and provides a mechanism for dynamically speculating which predefined dictionary to select per input data block, thereby achieving close to a dynamic Huffman ratio at a static Huffman rate. In addition, a feedback loop is used to monitor the ongoing performance of the preset currently selected for use by the hardware accelerator. If the current preset is not optimal it is replaced with an optimal preset.

Abstract: An image coding apparatus provides a run-length encoding unit RLE1 that subjects quantized coefficients which are obtained by quantizing frequency components of an image signal to a variable length coding process by using a run value Run that indicates the number of successive zero coefficients and a level value Lev that indicates a value of a non-zero coefficient following the zero coefficients. The run-length encoding unit RLE1 includes a reordering unit Lreodr for reordering level values Lev; a variable length coder LVLC for coding reordered level values ROLev by using a code table that is selected according to the value of a quantization parameter QP; a reordering unit Rreodr for reordering run values Run from high frequency component of the quantized coefficients to low frequency component; and a variable length coder RVLC for coding reordered run values RORun by using a code table that is selected according to the number of already-processed run values.

Abstract: A system and method of accelerating dynamic Huffman decompaction within the inflate algorithm. To improve the performance of a decompression engine during the inflate/decompression process, Huffman trees decompacted a priori are used thus eliminating the requirement of decompacting the DHT for each input stream. The Huffman tree in the input stream is matched prior to decompaction. If a match is found, the stored decompacted Huffman tree is used which reduces the required decompression time.

Abstract: This disclosure describes techniques for coding an enhancement layer in a scalable video coding (SVC) scheme. The techniques involve run-length coding of significant coefficients and refinement coefficients of the enhancement layer. Rather than performing two different run-length passes to separately code the significant coefficients and refinement coefficients, the techniques of this disclosure perform run-length coding of the significant coefficients and refinement coefficients together. Therefore, run values of the run-length coding codes the significant coefficients with the refinement coefficients. Additional techniques are also described, which can eliminate the need to send sign information for some of the refinement coefficients. Instead, this sign information for some of the refinement coefficients may be derived at the decoder based on the sign values of corresponding coefficients of previously encoded layers of the SVC scheme, which can further improve compression efficiency.

Abstract: A dynamic decoding lookup table generation method is provided. The generation method includes: receiving a variable length coding (VLC) table; and dynamically establishing an adaptive decoding lookup table from the VLC table according to a target decoding rate and a free system memory resource.

Abstract: A system and method of accelerating dynamic Huffman decompaction within the inflate algorithm. To improve the performance of a decompression engine during the inflate/decompression process, Huffman trees decompacted a priori are used thus eliminating the requirement of decompacting the DHT for each input stream. The Huffman tree in the input stream is matched prior to decompaction. If a match is found, the stored decompacted Huffman tree is used which reduces the required decompression time.

Abstract: At least one example embodiment discloses a method of compressing data in a storage device. The method includes determining a codeword length of a symbol using a first table indicating a relationship between a number of occurrences of the symbol in received data and the codeword length, determining a codeword having the codeword length for the symbol, and generating compressed data of the received data, the generating including converting the symbol into the codeword.

Abstract: A Huffman decoder includes a storage module, a receiving module, and a determining module. The storage module stores a target path corresponding to a rare path. The receiving module receives a codeword in a source data stream and acquires corresponding path data for the codeword. The determining module compares the path data and the target path, and determines the codeword as the rare code when the path data and the target path are the same.

Abstract: A data-driven encoder receives fixed-length bit fields and generates variable length bit fields that are, on average, smaller than the fixed-length bit fields. The data-driven encoder removes leading zeros from a fixed-length bit field and appends a prefix code to the remaining bits that identifies the number of remaining bits. In an embodiment, the data-driven encoder may further append leading zeros before the prefix code to produce variable length bit fields having sizes that are integer multiples of bytes. The decoder identifies the original fixed-length bit fields from the variable length encoded bit fields.

Abstract: A semiconductor device may include a coding lookup table unit including a plurality of coding lookup tables each of which is selected by a respectively selection signal, and a selection unit configured to receive one of N-bit parallel data and extract respective encoded data corresponding to the selection signal and to which the N-bit parallel data is mapped from the coding lookup table unit, and encoded data and extract respective N-bit parallel data corresponding to the selection signal and to which the encoded data is mapped from the coding lookup table unit, wherein N is 2 or an integer greater than 2, and wherein the coding lookup tables respectively store a plurality of coded data patterns that respectively correspond to patterns of the N-bit parallel data and are random temporally and spatially.

Abstract: Data encoded by replacing each of a plurality of characters with bit strings is received. On the basis of definition information, at least one of the characters is recorded as corresponding to each of the bit lengths, and decode information is generated based on the number of characters, wherein the decode information includes bit string information for sorting the bit strings in a bit length order that is a predetermined order associated with bit lengths. In response to receiving a particular bit length, character information in which the characters are sorted in the bit length order is generated by inserting a character corresponding to the particular bit length into a position corresponding to the particular bit length in an array in which at least one of the bit lengths.

Abstract: A method of compressing sorted data representation symbols sequentially. Steps include determining whether a symbol currently being encoded is identical to an immediately preceding symbol; encoding the result as a binary event; if the symbols are identical, encoding the symbol ends; if the symbols are different and there is a constant difference between several previous pairs of symbols, determining whether the difference between the current symbol a and the symbol immediately preceding it b is the same as the difference between the symbol b and the symbol immediately preceding it c, and encoding the determination result as another binary event; in the case of positive result of the latest determination, encoding the symbol ends; otherwise, encoding the symbol using a bitwise operation in which bits of the symbol's binary representation are processed sequentially from the most significant bit to the least significant bit. A corresponding decompression method is provided.

Abstract: A decoding apparatus and method store at least one table including at least one code, receive at least one instruction signal, and extract a symbol value and a symbol length from the at least one table based on the at least one instruction signal. The decoding apparatus calculates a target suffix length that minimizes the size of a generated table and minimizes the size of a non-prefix length of the at least one code.

Abstract: Apparatus having corresponding methods and tangible computer-readable media comprise: an input module to receive a bitstream representing data words encoded according to a variable-length code; a peek module to select a peek block comprising a predetermined number of consecutive bits in the bitstream; and a decoder to provide a plurality of the data words based on the peek block.

Abstract: In a coding system, input data within a system is encoded. The input data might include sequences of symbols that repeat in the input data or occur in other input data encoded in the system. The encoding includes determining a target segment size, determining a window size, identifying a fingerprint within a window of symbols at an offset in the input data, determining whether the offset is to be designated as a cut point and segmenting the input data as indicated by the set of cut points. For each segment so identified, the encoder determines whether the segment is to be a referenced segment or an unreferenced segment, replacing the segment data of each referenced segment with a reference label and storing a reference binding in a persistent segment store for each referenced segment, if needed.

Abstract: Information that includes first information identifying integer quotients obtained by divisions using prediction residuals or integers not smaller than 0 that increase monotonically with increases in the amplitude of the prediction residuals, as dividends, and a separation parameter decided for a time segment corresponding to the prediction residuals or a mapped integer value of the separation parameter, as a modulus, and second information identifying the remainders obtained when the dividends are divided by the modulus is generated as a code corresponding to the prediction residuals, and each piece of side information that includes the separation parameter is subjected to variable length coding.

Abstract: A functional compression scheme involves determining a minimal entropy coloring of a characteristic graph of a random variable. Various scenarios are disclosed where the determination of the minimal entropy coloring of a characteristic graph is easy and tractable.

Abstract: Provided are a computer program product, system, and method for generating a code alphabet for use by a deployed program to determine codewords for words. A first code alphabet is generated having a first number of symbols that provide variable length codings of the words. The symbols in the first code alphabet are merged into a second number of groups of the symbols in the first code alphabet, where the second number is less than the first number. A second code alphabet is generated having the second number of symbols, wherein a second average codeword length of the codewords produced using the symbols in the second code alphabet is smaller than the codeword length (b) of the words, and wherein the second code alphabet comprises the code alphabet used by the deployed program.

Abstract: The simulation of film grain in a video image occurs by first creating a block (i.e., a matrix array) of transformed coefficients for a set of cut frequencies fHL, fVL, fHH and fVH associated with a desired grain pattern. (The cut frequencies fHL, fVL, fHH and fVH represent cut-off frequencies, in two dimensions, of a filter that characterizes the desired film grain pattern). The block of transformed coefficients undergoes an inverse transform to yield a bit-accurate film grain sample and the bit accurate sample undergoes scaling to enable blending with a video signal to simulate film grain in the signal.

Abstract: Mechanisms are provided for decoding a variable length encoded data stream. A decoder of a data processing system receives an input line of data. The input line of data is a portion of the variable length encoded data stream. The decoder determines an amount of bit spill over of the input line of data onto a next input line of data. The decoder aligns the input line of data to begin at a symbol boundary based on the determined amount of bit spill over. The decoder tokenizes the aligned input line of data to generate a set of tokens. Each token corresponds to an encoded symbol in the aligned next input line of data. The decoder generates an output word of data based on the set of tokens. The output word of data corresponds to a word of data in the original set of data.

Abstract: A method of decoding data that is encoded with a set of prefix codes begins by receiving the data at a computing device, and then compiling native machine code from the prefix code set for execution by a processing unit of the computing device. The machine code implements a binary tree of prefix codes that corresponds to the prefix code set. The data is decoded by traversing the prefix code tree, which is effected by executing the machine code with the processing unit.

Abstract: A method of separating data blocks with stationary informational characteristics, including the steps of sequentially collecting statistics for small data blocks in an input data set, calculating the relative change in the estimated compression efficiency for a solid block currently being formed caused by merging its statistics with the statistics of a next small block, deciding whether the small block should be added to the solid block; for any block for which the decision is no, the block is used as the starting block of the next solid block to be formed. Auxiliary block data type detection is used to improve the method.

Abstract: A method for encoding video includes receiving data, and encrypting the data using at least four Huffman trees. A method for encoding video includes receiving data, and encrypting the data such that an internal state of a stream cipher is independent of plaintext and ciphertext. A video encoding system for encoding video in a computing environment includes means for accessing data, and means for encrypting the data such that there are approximately 2106 possibilities.

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: A system and method of selecting a predefined Huffman dictionary from a bank of dictionaries. The dictionary selection mechanism of the present invention effectively breaks the built-in tradeoff between compression ratio and compression rate for both hardware and software compression implementations. A mechanism is provided for automatically creating a predefined Huffman dictionary for a set of input files. The dictionary selection mechanism achieves high compression rate and ratio leveraging predefined Huffman dictionaries and provides a mechanism for dynamically speculating which predefined dictionary to select per input data block, thereby achieving close to a dynamic Huffman ratio at a static Huffman rate. In addition, a feedback loop is used to monitor the ongoing performance of the preset currently selected for use by the hardware accelerator. If the current preset is not optimal it is replaced with an optimal preset.

Abstract: A system and method of selecting a predefined Huffman dictionary from a bank of dictionaries. The dictionary selection mechanism of the present invention effectively breaks the built-in tradeoff between compression ratio and compression rate for both hardware and software compression implementations. A mechanism is provided for automatically creating a predefined Huffman dictionary for a set of input files. The dictionary selection mechanism achieves high compression rate and ratio leveraging predefined Huffman dictionaries and provides a mechanism for dynamically speculating which predefined dictionary to select per input data block, thereby achieving close to a dynamic Huffman ratio at a static Huffman rate. In addition, a feedback loop is used to monitor the ongoing performance of the preset currently selected for use by the hardware accelerator. If the current preset is not optimal it is replaced with an optimal preset.

Abstract: A system and method of selecting a predefined Huffman dictionary from a bank of dictionaries. The dictionary selection mechanism of the present invention effectively breaks the built-in tradeoff between compression ratio and compression rate for both hardware and software compression implementations. A mechanism is provided for automatically creating a predefined Huffman dictionary for a set of input files. The dictionary selection mechanism achieves high compression rate and ratio leveraging predefined Huffman dictionaries and provides a mechanism for dynamically speculating which predefined dictionary to select per input data block, thereby achieving close to a dynamic Huffman ratio at a static Huffman rate. In addition, a feedback loop is used to monitor the ongoing performance of the preset currently selected for use by the hardware accelerator. If the current preset is not optimal it is replaced with an optimal preset.

Abstract: Methods and systems are described for combining sources in a data compression system. In a system in which a context model results in the production of multiple sources or symbols, each source being associated with a probability estimate, sources may be combined by defining another, reduced size, set of probabilities. The new set of probabilities may be a subset of the predefined set of probabilities provided by the context model. Minimizing relative entropy may be a basis upon which to define a mapping of predefined probabilities to the new set of probabilities. An input sequence that was modeled using the context model may then be entropy encoded and entropy decoded using the new set of probabilities based on a mapping between the new probabilities and the predefined probabilities.

Abstract: A method for compressing a data stream includes transforming a data stream into a transformed data stream of referencing symbols and other data elements, the referencing symbols representing a data sequence identical to a data sequence in a reference data block; and encoding the referencing symbols by replacing them with codewords according to an encoding scheme, the transformed stream includes at least one control symbol indicating a change between a portion of the transformed data stream containing a sequence of the other data elements and a portion of the transformed data stream containing a sequence of the codewords for the referencing symbols, the location of the control symbol within the transformed data stream defines the end of the respective portion of the transformed data stream, the encoding scheme providing at least one codeword associated to one of the referencing symbols is longer than a codeword representing the control symbol.

Abstract: The present invention provides a convolutional line coding method, including: constructing a sequence set, where the length of each sequence in the sequence set is n bits; selecting a balanced sequence in the sequence set, and obtaining source data of n?1 bits corresponding to the balanced sequence; performing Hamming distance detection for an unbalanced sequence in the sequence set to obtain source data of n?1 bits corresponding to the unbalanced sequence; sorting the balanced sequence and the unbalanced sequence according to an operation difference value, and generating a code table, where the source data of n?1 bits correspond to the sequence of n bits, and the code table is designed for line coding; and at time of encoding the source data of n?1 bits, obtaining a coding result of n bits according to a mapping relation in the code table.

Abstract: An information processing apparatus for converting fixed-length codes into variable-length codes comprises: an input unit configured to obtain each of the fixed-length codes as an input code; a determination unit configured to determine a fixed length encoding method of the input code; a conversion unit configured to perform variable length encoding, by using a first variable length encoding method, on the input code encoded by a first fixed length encoding method, and perform variable length encoding, by using a second variable length encoding method, on the input code encoded by a second fixed length encoding method; and an output unit configured to output a variable-length code obtained by the conversion unit.

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 In a data encoding apparatus, an acquisition unit acquires an input data including a plurality of arranged data. A conversion unit searches a data group including a first consecutive data and a second data adjacent to the first consecutive data, each data of the first consecutive data having a first value and the second data having a second value, and converts the data group into an intermediate data. A selection unit selects a selected encoding method among a plurality of encoding methods, at a time of encoding the intermediate data based on where a beginning of the data group corresponding to the intermediate data exists in the input data. An encoding unit can encode the intermediate data by using the selected encoding method.

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: A method for decoding encoded data includes receiving data encoded by replacing each of a plurality of characters with bit strings. The method also includes recording, on the basis of definition information, at least one of the characters as corresponding to each of the bit lengths, and generating decode information based on the number of characters, wherein the decode information includes bit string information for sorting the bit strings in a bit length order that is a predetermined order associated with bit lengths. The method also includes, in response to receiving a particular bit length, generating character information in which the characters are sorted in the bit length order by inserting a character corresponding to the particular bit length into a position corresponding to the particular bit length in an array in which at least one of the bit lengths.

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: 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 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: 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: A Huffman decoder includes a storage module, a receiving module, and a determining module. The storage module stores a target path corresponding to a rare path. The receiving module receives a codeword in a source data stream and acquires corresponding path data for the codeword. The determining module compares the path data and the target path, and determines the codeword as the rare code when the path data and the target path are the same.

Abstract: A recording medium stores an information processing program that causes a computer to execute storing a compression symbol map group having a bit string indicating for each character code, presence or absence of the character code in a file group, and a Huffman tree whose leaf corresponding to the character code has a pointer to a compression symbol map of the character code, the Huffman tree converting the character code into a compression symbol of the character code; compressing sequentially and according to the Huffman tree, a character code to be compressed and described in a file of the file group; detecting access to the leaf at the compressing; identifying by a pointer in the accessed leaf, a compression symbol map of the character code to be compressed; and updating a bit that indicates presence or absence of the character code to be compressed, in the identified compression symbol map.

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 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: 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.