Abstract: A system and method that provides a unique or custom context for a plurality of blocks of data, yet compresses the blocks independently from the others, such that each block is independently decompressible. The method analyzes a collection of blocks for compression, and computes a unique context, such as a Huffman tree, given the distribution of symbols or phrases across all the blocks in the collection. Each block in the collection can be independently decompressed, in any order, using the shared context that is common to the collection.

Abstract: The present invention provides a method for tuning output drivers to an operating frequency based on settings used to tune other devices within the device such as a VCO. First the VCO within a PLL and clock circuit is tuned to the desired operating frequency. This operating frequency then corresponds to a discrete tuning setting. The discrete setting that causes the VCO to function at the operating frequency are then transferred to scaled amplifiers within output drivers. These drivers are then tuned to the operating frequency with these settings. This process eliminates the need to individually tune each output driver to function properly at the operating frequency.

Abstract: A method of data transmission from a data source to a data sink via a bus system. Run length encoding of the data to be transmitted is performed, where data units 1; 1′ having two data elements 2, 3; 2′, 3′ are used, the first data element 2 of which contains a repeat factor n of a datum D, and the second data element 3 contains the corresponding datum D; and at least one predefined repeat factor m in the first data element 2′ is defined as a flag for the presence of additional information ZI, where the second data element 3′ contains the additional information ZI.

Abstract: The compression efficiency of variable length coding is preserved by altering the syntax of a bit stream input to a variable length coder if the bit stream is likely to include a symbol with a high occurrence probability.

Abstract: Apparatuses and methods for decoding a bit stream of variable-length and fixed-length codewords representing encoded digital content. A decoder includes a memory for storing microinstructions that control the decoder. The decoder further includes a first barrel shifter for extracting a first bit field from the bit stream, a position of the first bit field being specified by the microinstruction, and a second barrel shifter for extracting a second bit field from the bit stream, a position of the second bit field being specified by the microinstructions. A microprogram counter keeps an address of a currently-executing microinstruction of the microinstructions, where a next state of the microprogram counter is determined by the microinstructions and the first bit field. A data converter modifies a value of the second bit field according to the microinstructions. A data storage stores either data in the microinstructions or an output of the data converter as decoded data values.

Abstract: A method and system for decompressing image data in a digital scanning system such as a printer. A plurality of streams of digital data are received in a compressed format. The compressed format contains a control byte preceding a plurality of data bytes. A initial RLE mode bit of the control byte indicates whether the following data bytes are run length encoded or not run length encoded and subsequent bits indicate a repeat amount. If the following data bytes are run length encoded, the decompression apparatus determines the number of times the data byte(s) are to be repeated at the output of the apparatus. In special cases where the repeat count is a zero, the mode bit may indicate that the data byte is to be repeated either to an end of scan marker or to an end of object marker. The RLE mode bit may also indicate that non-run length encoded data is to be passed through as-is, preferably in multiples of a selected integer number.

Abstract: A method and apparatus enabling the substantially concurrent operation of multiple decimators within a digitizing measurement device such as a digital storage oscilloscope (DSO), wherein the multiple decimators provide multiple processed sample streams that may be used for a composite presentation of input signal data.

Abstract: A system and method that efficiently compresses data sets that contain one or more repetitive data values. Substitute symbols represent repeated data sequences in the compressed data output. Data sequences that terminate with one or more of a particular value are specially processed by storing their substitute symbols separately from the general substitute symbol dictionary so that they are able to be more efficiently accessed. Substitute symbols for contiguous data sequences that consist of those particular values are also stored separately. The preferred embodiment specially processes data sequences that contain data bytes equal to zero.

Abstract: To realize image coding/decoding device that can compress an input multivalued image with high compression efficiency, the following measures are taken. First and second predictors predict the value of a target pixel based upon image data according to respective predetermined methods and respectively generate predicted value data. A run counter compares the image data and the predicted value data and if prediction hits and run continues to a pixel immediately before a count value of the run of the corresponding predictor is incremented by one. If there is no predictor the prediction of which hits and the runs of which continued to a pixel immediately before, the runs are sent to a selector together with the identification number of the predictor as run data. The selector selectively outputs a run value and an identification number or prediction error data from a prediction error calculator and outputs after the selector encodes it (them).

Abstract: In one example embodiment, data is transferred at high speeds over a parallel data bus without loss of data integrity by transferring the data encoded with the quantity of ones relatively the same as the quantity of zeroes. Consistent with one embodiment of the present invention, a bus-interface circuit encodes a set of X data bits into a set of Y data bits, where Y is greater than X. The encoding is implemented to approximately balance the number of ones and the number of zeroes in each set to be transmitted. A specific example application involves encoding the set of X data bits so that there is a balanced number of ones and zeroes in the set of Y data bits. In certain applications, the present invention is implemented to reduce current flow between transmitting and receiving modules and thereby reduce EMI, reduce the number of power pins required for the bus interface, and/or reduce the I/O delay and the skew from voltage sag in the signals passed over the parallel data bus.

Abstract: A scalable physical coding sublayer (PCS) can be adjusted to provide different combinations of communication channels and data widths. The PCS can use 8B/10B encoders having a disparity input connection and at least one disparity output connection. In one embodiment, the encoder has both a synchronous and an asynchronous disparity output connection. The encoder can be coupled with additional encoders to provide an expanded width channel of 16B/20B encoding. Additional configurations are possible. In expanded operation, only one of the encoders needs to output special codes. The encoders, therefore, include a slave input connection to place the encoder in a slave mode so that a special code is replaced with an inert special code. All but one encoder in an expanded system are slave encoders. An idle input connection is also provided in the encoders to place the encoder in an idle mode where pre-defined data is output from the encoder.

Abstract: A Huffman encoder and a method for Huffman encoding in which a data compression rate can be easily changed and a recording medium having a program for a Huffman encoding process recorded thereon. A quantizer quantizes DCT coefficients output by a DCT device to output quantized DCT coefficients. A comparator judges a quantized DCT coefficient to be an invalid coefficient when the absolute value of the DCT coefficient is equal to or smaller than a threshold and judges the quantized DCT coefficient to be a valid coefficient when the absolute value of the DCT coefficient is greater than the threshold. A run length counter counts the number of consecutive invalid coefficients to output run lengths and outputs valid coefficients. An encoder performs encoding based on the valid coefficients and the run lengths to output encoded data.

Abstract: A method and apparatus for variable length coding is described. A method comprises receiving a group of data having a group of set values, identifying a group of positions of the group of set values within the group of data without branching, for each of the group of positions, encoding a run of non-set values preceding each of the group of positions.

Abstract: The invention concerns a method of coding a set of coefficients representing physical quantities,

Abstract: A method for run-length encoding two or more data values, the method comprising: loading the data values into storage by forming a first data string, the data string comprising a plurality of data sub-strings and each data sub-string representing at least one of the data values; generating a second data string having a data sub-string corresponding to each data sub-string of the first data string, all the bits of each of the data sub-strings of the second data string having a first predetermined value if all the bits of the corresponding data sub-string of the first data string have a second predetermined value and having a third predetermined value if any of the bits of the corresponding data sub-string of the first data string has other than the second predetermined value; starting from a predetermined end of the second data string, counting the number of consecutive bits of the second data spring having the first predetermined value; and dividing the said number by the number of bits in each data sub-strin

Abstract: A clock synchronization device is disclosed that includes a phase detecting unit for detecting a phase difference between an external clock signal and an internal clock signal, a binary code generating unit for outputting a binary code value according to output signals from the phase detecting unit, a code converting unit for converting the binary code value from the binary code generating unit into a thermometer code value, a D/A converting unit for outputting a voltage corresponding to the thermometer code value from the code converting unit and a clock synchronization control unit for outputting the internal clock signal from the external clock signal according to the output voltage from the D/A converting unit. As the result, the clock synchronization device is controlled by employing the D/A converting unit for converting the binary code to the thermometer code in order to decrease the number of the registers, the leakage current and the chip size.

Abstract: A method for significantly decreasing the number of times prior art coding schemes, such as variable length coding, are implemented in the course of encoding/decoding a given data block includes cataloging the occurrences, or locations, of a designated frequently occurring value in the data block and then excluding the frequently occurring value from the prior art coding scheme.

Abstract: A lossless data compression system comprises a content addressable memory dictionary (30), a coder (38), and a run length encoding means (39) connected to receive the output of the coder (38), the encoding means (39) being arranged to count the number of times a match consecutively occurs at a predetermined dictionary location, i.e. the number of times the same search tuple is loaded into the same address (50) of the dictionary. Compression is improved.

Abstract: In methods for compressing data, when differences between two adjacent data among a series of N data , where N is a positive integer, are all less than a reference value, delta data values are generated on the basis of the differences. When the differences are the reference value or less and at least one delta data is stored, a command indicating that compression operations are performed on the basis of the differences, the number of the stored delta data, and the stored delta data are generated as compressed data. The compression method of the present method can obtain higher compression efficiency as compared with conventional RLC or modified-RLC compression methods.

Abstract: A video data transmitting device for discriminatively protecting compressed video data from errors according to the significance of the data and for transmitting the video data, and a video data receiving device for decompressing video data transmitted by the transmitting device, are provided. The video data transmitting device includes a compression portion for discriminating the significance of the video data, generating region information classified by regions, compressing the video data by regions according to the region information, and outputting compressed video data, and a coding portion for receiving the region information and the compressed video data, coding the compressed video data by regions according to a predetermined coding rule corresponding to the significance included in the region information using the RCPC coding method, inserting a predetermined marker into the coded data, and outputting channel-coded video data via a communications channel.

Abstract: Data compression techniques reduce a number of encoding words for compressing data. One technique is to assign a common encoding word to a group of data whose activation sequence is pre-selected. Another technique is to assign an encoding word to a pair of converted data. Yet another technique is to assign an encoding word that is indicative of the length of the repletion in the converted word. The above assignments substantially reduces a number of encoding words for the converted words in a process of data compression.

Abstract: The invention relates to compressing and decompressing digitized analogue signals, such as speech or music, by continuously adjusting the sampling rate to the time-varying information density of any given signal. The invention consists of three main parts: 1) a technique for measuring the time-varying information density of the signal, utilizing a line search for the optimal time-varying rate. 2) a technique for compressing and decompressing the signal by digitally resampling the signal from a constant high rate to a time-variable lower rate that follows the measured time-varying information density in the signal, and 3) a technique for decompression by resampling back to a constant high rate. The preferred embodiment utilizes a generalization of the cardinal series reconstruction kernel which is directly expressed in terms of the varying sampling rate.

Abstract: A method for significantly decreasing the number of times prior art coding schemes, such as variable length coding, are implemented in the course of encoding/decoding a given data block includes cataloging the occurrences, or locations, of a designated frequently occurring value in the data block and then excluding the frequently occurring value from the prior art coding scheme.

Abstract: The present invention is directed to a variable coding of the bit-planes for a particular source signal. This includes first partitioning or grouping the different bit-planes into embedded sub-signals and then coding each sub-signal. This technique enables an encoder according to the present invention to control and achieve a desired trade-off point between scalability and coding-efficiency. Therefore, in cases where bit or bit-plane level granularity is not required, coding efficiency can be improved by combining two or more bit-planes prior to coding. In addition, since the statistical nature of each bit-plane is different, the level of grouping used across the bit-planes can vary.

Abstract: A sampling system includes an input terminal for receiving a data signal having a signal component and possibly a noise component. A sampler samples the data signal at a sample rate set in responsive to a control signal. A noise detector detects the presence of a noise component, and if a noise component is detected, generates the control signal conditioning the sampler to sample the data signal at a first sample rate satisfying the Nyquist criterion for the data signal including the noise component, and otherwise generating the control signal conditioning the sampler to sample the data signal at a second data rate satisfying the Nyquist criterion for the data signal including only the signal component.

Abstract: A minimum difference from the predictive loop outputs for each block in a predetermined length of time to delete a run common to the blocks and subjects the shifted up data to the Huffman conversion. Thus, the source data of a 96 kHz/24 bits/6 ch format (13.824 MBps) can be compressed at a compression ratio of 0.7 so that the data rate is not greater than 9.6 Mbps determined by the DVD format. Similarly, mode of 192 kHz/24 bits/2 ch format and the like can be realized. A large amount of the linear PCM super-audio data are compressed can be recorded and reproduced in the DVD format, and the recording time is increased.

Abstract: During the transformation of data, for example the decoding of encoded and transformed data, there is front-end processing (FE) to generate a data block for subsequent back-end processing (TR), this front-end processing may include run-length decoding (RLD). Auxiliary data (AUX) indicating the structure of the data block (MB) is also generated during the front-end processing. Typically, the auxiliary data is indicative of the location of zero coefficients within the data block. The implementation of the back-end processing (TR) is adapted to the structure of the data block (MB) based upon the content of the auxiliary data (AUX), thereby making the implementation more efficient. For example, the content of the auxiliary data can determine which shortcuts can be applied during the implementation of an inverse discrete cosine transformation.

Abstract: The present invention provides a variable length decoder which can reduce the processing time. The variable length decoder of the present invention comprises plural decoding table address generation circuits, and a selector for selecting one of plural address candidates generated from these circuits. During decoding of one variable length code, the variable length decoder obtains address candidates for the next variable length code, and then selects one of the address candidates for the next variable length code on the basis of an obtained code length of the variable length code, to output the same to the decoding table RAM.

Abstract: The present invention relates to a transcoding device comprising partial decoding means (PD) for receiving a primary coded signal (S1) and providing a dequantized signal (IQS) including DCT coefficients ; quantization means (Q) for receiving the dequantized signal and providing a quantized signal (QS) using correction matrices (COR); and partial encoding means (PE) for receiving the quantized signal and providing a secondary coded signal (S2). Such a transcoding device allows the primary signal encoded at a first bit rate to be converted into the secondary signal encoded at a second bit rate lower than the first one while an optimum signal quality is maintained.

Abstract: A system and method for the on-demand transcoding of media content from a source type to a destination type is provided, wherein the system includes a plurality of transcoders for transcoding from a plurality of source types to a plurality of destination types, and wherein the system receives a transcoding request for media content, fetches the media content in response to the transcoding request, sends the media content to one of the plurality of transcoders based on the source type and destination type, transcodes the media content from the source type to the destination type, thereby generating transcoded media content, and transmits the transcoded media content. The system fetches, sends, and transcodes the media content and transmits the transcoded media content in a pipelined fashion. The system also provides for the publication of media content as a file or stream of digital data, for the archiving of media content, and the caching of transcoded media content to improve system efficiency.

Abstract: An encoder is provided that converts data words into code words. The code words, when concatenated together, are such that sub-strings of consecutive first symbols in the code words have no more symbols than a maximum number; sub-strings having the maximum number of consecutive first symbols and beginning at selected locations within the code words appear without restriction, and sub-strings having the maximum number of consecutive first symbols and beginning at locations other than the selected locations appear only where the sub-string is concatenated with an acceptable secondary sub-string. A method is also provided for generating a set of such code words for an encoder.

Abstract: A method for reducing radio frequency interference from a high frequency serial bus by scrambling data signals and reducing the repetition of control signals. Beginning and ending control signals are provided with meaningless signals provided therebetween.

Abstract: Entropy encoding and decoding of data with a code book containing variable length entropy-type codes that are assigned to variable length input symbol groupings. The variable length input sequences are identified by scanning an input channel, such as a live broadcast, non-volatile data storage, or network connection (e.g., LAN, WAN, Internet). Each time a symbol grouping is recognized, a corresponding entropy-type code is output as a replacement for the input stream. Decoding is the inverse process of encoding, where a code word is looked up in the code book and the corresponding original input is obtained.

Abstract: A method and computer program product are provided for implementing text conversion table compression. For implementing text conversion table compression, a character sequence is loaded from a full-size conversion table. The character sequence is checked for one of plurality of character patterns. Responsive to identifying one of the plurality of character patterns, the character sequence is compressed into a compressed conversion table for the identified one character pattern. Responsive to failing to identify one of the plurality of character patterns, the character sequence is copied into the compressed conversion table. The character sequence from the full-size conversion table is checked for one of the plurality of character patterns including a repeating character sequence, a ramping character sequence, and a repeating high byte character sequence.

Abstract: A portable information equipment has a main body portion and a display portion hinged each other. A space is secured in the display portion by using a cabinet for a reflection type liquid crystal display which requires no backlight instead of a liquid crystal display with backlight. The space is used for an additional internal battery. The additional internal battery increases an electric capacity to extend an operation time of the portable information equipment and need no externally attached extension battery.

Abstract: A code concatenating unit incorporates carry signals in a retained remaining code, and couples thereto an inputted variable length code to generate a concatenated code. An undefined code length detection unit, and first to third computation units acquire the code length of a defined code portion that is not influenced by the carry signal and output the same. As long as the whole of the concatenated code is an undefined code, a cumulative addition/subtraction unit adds cumulatively its code length, and a code generation unit generates and outputs a predetermined defined code with the cumulative value as its code length.

Abstract: For every data, the number of data matches that occurred consecutively is written to a memory together with nonmatching data, and data from the memory is read out to continuously perform subsequent data processing and detect, at the same time, the last data written to the memory. To achieve this, a desired value is set in a data register, and a comparison instruction is issued by which the value set in the register is compared with a value set in a second register, and the number of matches that occurred consecutively is output together with nonmatching data; upon the output of a retrieval counter reaching a predetermined value, the comparison instruction is terminated, whereupon the number of consecutive matches, the nonmatching data, and an end flag signal are written to the memory at the same address.

Abstract: A novel system and method are provided for storing a configuration data file for a programmable logic device such as an FPGA and for loading such a file into the device. The system and method of the present invention improves the performance of a bitstream storage apparatus by compressing the bitstream by a factor of about 5:1 to 10:1 before loading the bitstream into a storage unit, and then decompressing the bitstream, preferably within the storage unit, before forwarding the bitstream to the programmable device. In one embodiment, the decompression circuit is programmable, being able to utilize any of two or more different algorithms. In this embodiment, several different compression algorithms are evaluated, and the most efficient algorithm for that particular bitstream is utilized.

Abstract: In a data compressor, the input stream of data characters is formed into one or more data character groupings where each grouping comprises a predetermined number of the data characters (grouped character) followed by one or more of the input data characters. The formed input is compared to similarly configured stored strings until a longest match is determined. Each stored string has a code associated therewith and the code of the longest match is output by the compressor. An extended string is stored comprising the longest match extended by the data character that caused the mismatch. A next compression cycle begins with a grouped character comprising the data character that caused the mismatch concatenated by one less than the predetermined number of the next following data characters. In one embodiment, data character strings comprise an initial grouped character followed by as many data characters as can be matched.

Abstract: A frequency-domain audio coder selects among different entropy coding modes according to characteristics of an input stream. In particular, the input stream is partitioned into frequency ranges according to some statistical criteria derived from a statistical analysis of typical or actual input to be encoded. Each range is assigned an entropy encoder optimized to encode that range's type of data. During encoding and decoding, a mode selector applies the correct entropy method to the different frequency ranges. Partition boundaries can be decided in advance, allowing the decoder to implicitly know which decoding method to apply to encoded data. Or, adaptive arrangements may be used, in which boundaries are flagged in the output stream by indicating a change in encoding mode for subsequent data. For example, one can create a partition boundary which separates out primarily zero quantized frequency coefficients, from primarily non-zero quantized coefficients, and then apply a coder optimized for such data.

Abstract: Encoding and decoding systems and methods for digital data in 24 bit sequences. An encoder generates state variables as a function of four or fewer bits of the 24 bit sequence, and encodes the sequence into 11 and 14 bit codewords. After transmission, the 11 bit and 14 bit codewords are decoded using recovered state variables. The encoding places a run length limit (RLL) of k=7 on a 25 bit codeword comprised of the 11 and 14 bit codewords to limit runs of zeros. Each of the 11 bit and 14 bit codewords are preferably also encoded with a run length limit of interleaved bits is i=7. The encoding and decoding systems and methods can be applied to a magnetic disc drive.

Abstract: The subtracter performs subtraction processing between a pointer outputted from the pointer register and code words candidate outputted from the code word count storing circuit, and in accordance with whether the result is negative or positive, determines the code words of input data words. Code word candidates stored in the code word count storing circuit are created according to a finite-state transition diagram stored in the state transition storing circuit. An encoder and a decoder are thus made compact and faster.

Abstract: The disclosed data compressor receives an input stream of data characters and provides a corresponding stream of output codes. The compressor generates a sequence of numerically increasing output codes corresponding to numerically increasing contiguous segments of a detected run of the same data character. Non-run characters of the input stream are transmitted directly in synchronism with incrementing the codes of the code sequence. In one embodiment, the number of characters in the run segments are stored together with the respective codes representing the segments. In later encounters of a previously processed run, the stored data is accessed and the stored codes corresponding to the run segments are output as appropriate.

Abstract: A method of automatically selecting processing parameters for encoding digital content. Metadata containing the genre of the digital content, receiving the compression level selected for encoding the digital content is received. An algorithm selected for encoding the digital content is received. And a previously defined table to select the processing parameters for encoding the digital content based on the genre of the content, the compression level selected and the algorithm selected is indexed and the processing parameters are retrieved.

Abstract: The invention concerns a data encoding/decoding process. In the encoding process, data are converted from a decoded state into an encoded state in which: the data, both in the encoded state and in the decoded state, are in the form of a stream of binary information, by processing the decoded string of data from left to right, its current prefix and the next binary information being considered, a list of binary patterns being registered, in which for each is emphasized the last binary information and the corresponding prefix, a comparison is made between the current prefix of the decoded string and the prefixes of registered patterns. The list of patterns is a set of patterns that do not occur and when a prefix of the decoded string matches with a prefix of a registered pattern, the next binary information of the decoded string is omitted from the decoded stream to make the encoded stream.

Abstract: A method and system for handling literals in a Lempel-Ziv data compression system. The literals are arranged in a storage array in an MRU/LRU format in a defined sequential MRU/LRU order, with shorter MRU/LRU reference codes assigned to the MRU literals and longer MRU/LRU reference codes to the LRU literals. Upon receiving an input literal, a selector selects the literal and a reference encoder provides the assigned MRU/LRU reference code for the literal as the output. The literals are then rearranged. An incrementor responds to the literal selection, by incrementing downward one location in the sequential order, all the literals in the storage array from the top of the MRU order to the one of the literals in the order immediately preceding the selected literal, and the selector moves the selected literal to the top of the MRU order.

Abstract: A system for compressing and decompressing a data pattern of data bits, so as to obtain a highly compressed data record. In accordance with embodiments of the invention, a group of candidate numbers is provided with each number comprising a sequence of statistically random bits. Bits of a subject data pattern are compared with bits of each candidate of the group of numbers to find a largest sequence of bits of the subject data pattern which match a sequence of bits within any one of the group of candidate numbers. Stored are all of: the data pattern except the matched bits, information designating the candidate number providing a largest matching sequence of bits, locations of the matched bits in the subject data pattern and in the candidate number, and a number encoding a number of the matched bits.

Abstract: The disclosed data compressor compresses an input stream of data characters using LZW data compression. When the occurrence of a run of input data characters is detected, the run is processed by successively looking ahead into the input to determine the contiguous numerically increasing segments that exist in the run and by utilizing codes from the compressor code counter to correspond to the contiguous numerically increasing run segments. Alternatively, the detected run is processed by determining the length of the run and mathematically determining, from the length of the run, the respective codes from the code counter corresponding to the contiguous numerically increasing segments that exist in the run. Specifically, an iterative mathematical algorithm or a quadratic equation algorithm are utilized to process the run.

Abstract: The disclosed data compressor compresses an input stream of data characters using LZW data compression. When the occurrence of a run of input data characters is detected, the run is processed by successively looking ahead into the input to determine the contiguous numerically increasing segments that exist in the run and by utilizing codes from the compressor code counter to correspond to the contiguous numerically increasing run segments. Alternatively, the detected run is processed by determining the length of the run and mathematically determining, from the length of the run, the respective codes from the code counter corresponding to the contiguous numerically increasing segments that exist in the run. Specifically an iterative mathematical algorithm or a quadratic equation algorithm are utilized to process the run.

Abstract: A method of variable length coding/decoding of image data and an apparatus thereof can vary the length of an escape sequence during variable length coding to thereby reduce the amount of transmitted data. The method of variable length coding/decoding includes the steps of loading an initial potential maximum run length; determining a number of bits necessary to express the potential maximum run length, coding a run length using the necessary number of bits and decreasing the potential maximum ran length by an amount equal to the previously coded run length to arrive at a new potential maximum ran length until an end of a block to be encoded has been reached.