Abstract: Provided is a dynamic Huffman encoding method based on a sorting network. Compared with traditional dynamic Huffman coding solutions, the method implements sorting on the basis of the sorting network, therefore the sorting process is not only stable, but also may ensure a stable sorting result; and moreover, sorting steps and related operations are simpler, thereby greatly simplifying the sorting and iteration processes, and thus the sorting efficiency is higher. In addition, the sorting process better facilitates program implementation and transplantation, and implementation of hardware and software may achieve good effects. In addition, the present disclosure further provides a dynamic Huffman coding apparatus and device based on a sorting network, and a readable storage medium, and the technical effects thereof correspond to the technical effects of the above method.

Abstract: The disclosure provides image encoding methods and apparatuses. One example encoding method includes: obtaining a one-dimensional sequence of quantized coefficients of an image; obtaining a run-length value sequence and a level value sequence based on the one-dimensional sequence of the quantized coefficients; obtaining an updated second distribution probability of each level value in the level value sequence based on the m first distribution probabilities, the n second distribution probabilities, and a preset mapping rule; and performing encoding based on the level value sequence and the updated second distribution probability of each level value in the level value sequence to obtain and output encoded image data.

Abstract: There is provided a computer implemented method of compressing a baseline dataset comprising a sequence of a plurality of instances of a plurality of unique data elements, the method comprising: providing a weight function that calculates an increasing value for a weight for each one of the plurality of instances of each one of the plurality of unique data elements in the baseline dataset, as a function of increasing number of previously processed sequential locations of each of the plurality of instances of each respective unique data element within the baseline dataset relative to a current sequential location of the baseline dataset, computing an encoding for the baseline dataset according to a distribution of the weight function computed for the plurality of unique data elements in the baseline dataset, and creating a compressed dataset according to the encoding.

Abstract: Provided is a method for detecting duplicate audio content in an electronic device. The method includes receiving, by the electronic device, a plurality of audio content, decoding, by the electronic device, each of the audio content to extract a plurality of byte streams of each of the audio content and audio feature information, generating, by the electronic device, a unique signature for each of the audio content based on the plurality of byte streams of each of the audio content, and storing, by the electronic device, the unique signature of each of the audio content in the electronic device to identify duplicate audio content.

Abstract: A communication compression method based on model weight distribution in federated learning, and belongs to the technical field of wireless communication. Based on the existing federated average idea in federated learning, counts the distribution of model weight information to be transmitted between nodes during each communication, then performs scalar quantization and compression through Lloyd-Max quantizer according to their distribution characteristics, then encodes with Huffman coding method, and finally sends the codes to the target node, thereby the minimum mean square quantization error is realized and the number of bits required for communication is reduced.

Abstract: An audio decoder for providing a decoded audio information includes a arithmetic decoder for providing a plurality of decoded spectral values on the basis of an arithmetically-encoded representation of the spectral values and a frequency-domain-to-time-domain converter for providing a time-domain audio representation using the decoded spectral values. The arithmetic decoder is configured to select a mapping rule describing a mapping of a code value onto a symbol code in dependence on a context state. The arithmetic decoder is configured to determine or modify the current context state in dependence on a plurality of previously-decoded spectral values. The arithmetic decoder is configured to detect a group of a plurality of previously-decoded spectral values, which fulfill, individually or taken together, a predetermined condition regarding their magnitudes, and to determine the current context state in dependence on a result of the detection. An audio encoder uses similar principles.

Abstract: A method, computer program product, and system includes a processor obtaining data including values and generating a value conversion dictionary by applying a parse tree based compression algorithm to the data, where the value conversion dictionary includes dictionary entries that represent the values. The processor obtains a distribution of the values and estimates a likelihood for each based on the distribution. The processor generates a code word to represent each value, a size of each code word is inversely proportional to the likelihood of the word. The processor assigns a rank to each code word, the rank for each represents the likelihood of the value represented by the code word; and based on the rank associated with each code word, the processor reorders each dictionary entry in the value conversion dictionary to associate each dictionary entry with an equivalent rank, the reordered value conversion dictionary comprises an architected dictionary.

Abstract: Representative embodiments are disclosed for a rapid and highly parallel decompression of compressed executable and other files, such as executable files for operating systems and applications, having compressed blocks including run length encoded (“RLE”) data having data-dependent references. An exemplary embodiment includes a plurality of processors or processor cores to identify a start or end of each compressed block; to partially decompress, in parallel, a selected compressed block into independent data, dependent (RLE) data, and linked dependent (RLE) data; to sequence the independent data, dependent (RLE) data, and linked dependent (RLE) data from a plurality of partial decompressions of a plurality of compressed blocks, to obtain data specified by the dependent (RLE) data and linked dependent (RLE) data, and to insert the obtained data into a corresponding location in an uncompressed file.

Abstract: Embodiments provide a thread classification method that represents stack traces in a compact form using classification signatures. Some embodiments can receive a stack trace that includes a sequence of stack frames. Some embodiments may generate, based on the sequence of stack frames, a trace signature that represents the set. Some embodiments may receive one or more subsequent stack traces. For each of the one or more subsequent stack traces, some embodiments may determine whether a subsequent trace signature has been generated to represent the sequence of stack frames included within the subsequent stack trace. If not, some embodiments may generate, based on the trace signature and other subsequent trace signatures that were generated based on the trace signature, the subsequent trace signature to represent the subsequent sequence of stack frames.

Abstract: A highly programmable device, referred to generally as a data processing unit, having multiple processing units for processing streams of information, such as network packets or storage packets, is described. The data processing unit includes one or more specialized hardware accelerators configured to perform acceleration for various data-processing functions. This disclosure describes a parallel decoding of codewords within input data stream based on a codeword type and position.

Abstract: Systems and methods for encoding high resolution data associated with a relatively large number of bits to an encoded form having a relatively reduced number of bits. The method includes, by a processor: receiving an input image comprising one or more high resolution objects. The method further includes, for each of the one or more high resolution objects: identifying an object family for that object and determining whether a reference table exists for the object family. If a reference table exists for the object family, the method includes determining a size of that object, and identifying a tag based on the size. The method also includes encoding that object to form an encoded object having a relatively reduced number of bits, associating the identified tag with the encoded object, and saving the encoded object.

Abstract: Various embodiments are provided for length-limited Huffman encoding in a data compression accelerator in a computing environment by a processor. Symbol counts of a plurality of symbols in compressed data may be normalized and manipulated according to a maximum code length limiting operation such that those of the plurality of symbols having a least frequent symbol count have a symbol count equal to a maximum code length of a Huffman tree.

Abstract: Techniques disclosed herein relate to querying a hierarchical classification model that includes a plurality of classification models. The hierarchical classification model is configured to classify an input into a class in a plurality of classes and includes a tree structure. The tree structure includes leaf nodes and non-leaf nodes. Each non-leaf node has two child nodes associated with two respective sets of classes in the plurality of classes, where a difference between numbers of classes in the two sets of classes is zero or one. Each leaf node is associated with at least two but fewer than a first threshold number of classes. Each of the leaf nodes and non-leaf nodes is associated with a classification model in the plurality of classification models of the hierarchical classification model. The classification model associated with each respective node in the tree structure can be trained independently.

Abstract: One embodiment provides for a computer-implemented method comprising receiving a request to compile a set of program instructions coded in a high-level language, the set of program instructions including a pointer to a virtual memory address, the pointer having a pointer encoding including a base address and a length; while compiling the set of program instructions, decoding the base address and length from the pointer, wherein the base address specifies a first boundary for a memory allocation, the length defines a second boundary for the memory allocation and the length is an encoding of a size of the memory allocation; and generating a set of compiled instructions which, when executed, enable access to a physical address associated with a virtual address between the first boundary and the second boundary.

Abstract: Systems and methods described herein provides a method for dynamically allocating an iteration number for a decoder. The method includes receiving, at an input buffer, an input signal including at least one data packet. The method further includes calculating a first iteration number for decoding the at least one data packet. The method further includes monitoring at least one of available space of the input buffer and available decoding time for the at least one data packet. The method further includes dynamically adjusting the first iteration number to a second iteration number based on the available space or the available decoding time to continue decoding the at least one data packet.

Abstract: A memory device includes a compressed color table and corrective information. The compressed color table includes a first set of nodes of the color table compressed with a lossy compression at a selected compression ratio. The first set of nodes include a color difference within an error threshold at the selected compression ratio. Corrective information is included for a second set of nodes of the color table. The second set of nodes have a color difference outside the error threshold.

Abstract: Provided is an apparatus and method for encoding/decoding a moving picture based on adaptive scanning. The moving picture apparatus and method can increase a compression rate based on adaptive scanning by performing intra prediction onto blocks of a predetermined size, and scanning coefficients acquired from Discrete Cosine Transform (DCT) of a residue signal and quantization differently according to the intra prediction mode. The moving picture encoding apparatus includes: a mode selector for selecting and outputting a prediction mode; a predictor for predicting pixel values of pixels to be encoded of an input video based on the prediction mode to thereby output a residue signal block; a transform/quantization unit for performing DCT onto the residue signal block and quantizing the transformed residue signal block; and an encoder for adaptively scanning and encoding the quantized residue signal block based on the prediction mode.

Abstract: A data encoder including a preprocessor configured to divide a data stream into a plurality of sub data blocks; a plurality of meta data generators each configured to generate meta data from one of the plurality of sub data blocks; and a plurality of data compressors each configured to compress one of the plurality of sub data blocks according to the meta data.

Abstract: Embodiments provide a thread classification method that represents stack traces in a compact form using classification signatures. Some embodiments can receive a stack trace that includes a sequence of stack frames. Some embodiments may generate, based on the sequence of stack frames, a trace signature that represents the set. Some embodiments may receive one or more subsequent stack traces. For each of the one or more subsequent stack traces, some embodiments may determine whether a subsequent trace signature has been generated to represent the sequence of stack frames included within the subsequent stack trace. If not, some embodiments may generate, based on the trace signature and other subsequent trace signatures that were generated based on the trace signature, the subsequent trace signature to represent the subsequent sequence of stack frames.

Abstract: A language processing method and apparatus is disclosed. The language processing method includes obtaining, using an encoder, a first feature vector representing an input word based on an input sequence of first characters included in the input word. The method also generates, using a word estimator, a second feature vector representing a predicted word associated with the input word by processing the first feature vector using a language model, and decodes, using a decoder, the second feature vector to an output sequence of second characters included in the predicted word using the second feature vector.

Abstract: A method of copying a block of samples of a video bitstream, is disclosed. A plurality of adaptation parameters is read from a local memory store. Each adaptation parameter corresponds to a component of a multi-dimensional vector in the video bitstream. Each of the components of the vector is decoded from the video bitstream using the corresponding adaptation parameter. The block of samples is copied from the video bitstream. The spatial location of the block of samples is identified using the decoded components of the vector.

Abstract: A method of compressing digital image data is provided that includes selecting an entropy code for encoding a line of pixels in the digital image data, wherein the entropy code is selected from a plurality of variable length entropy codes, using spatial prediction to compute a pixel predictor and a pixel residual for a pixel in the line of pixels, and selectively encoding the pixel residual using one of the entropy code or run mode encoding.

Abstract: A storage device may program data differently for different memory areas of a memory. In some embodiments, the storage device may use different codebooks for different memory areas. In other embodiments, the storage device may modify bit orders differently for different memory areas. What codebook the storage device uses or what bit order modification the storage device performs for a particular memory area may depend on the bad storage locations specific to that memory area. Where different codebooks are used, optimal codebooks may be selected from a library, or codebooks may be modified based on the bad storage locations of the memory areas.

Abstract: A data processing apparatus executes a stream of instructions. Memory access circuitry accesses a memory in response to control signals associated with a memory access instruction that is executed in the stream of instructions. Branch prediction circuitry predicts the outcome of branch instructions in the stream of instructions based on a branch prediction table. Processing circuitry performs a determination of whether out-of-order execution of memory access instructions is to be performed based on memory prediction data, and selectively enables out-of-order execution of the memory access instructions in dependence on the determination. The memory prediction data is stored in the branch prediction table.

Abstract: B-Tree data is serialized to existing data for all types of workloads. Each of an identified data range is encoded with frequency encoding, wherein a first value in a frequency encoded identified data range is a first value in original data and all subsequent values in the frequency encoded identified data range are equal to a difference between a corresponding value in an input file and a previous value in the input file.

Abstract: A system includes an image transmitting unit and an image receiving unit. The image transmitting unit has a compression unit for compressing, in accordance with a provided compression parameter, a pixel block in image data, and a first transmitting unit for transmitting the compressed data to an image receiving unit in the system. The image receiving unit has a receiving unit for receiving the compressed data, a decompression unit for decompressing the received compressed data, a determination unit for determining a compression parameter based on the result of the decompression, and a second transmitting unit for transmitting the determined compression parameter to the image transmitting unit. The compression unit compresses an untransmitted second pixel block in the image data to be compressed in accordance with the compression parameter transmitted from the second transmitting unit.

Abstract: An imaging device and method for P-phase data compression are provided. The imaging device includes one or more circuits configured to receive a plurality of blocks of P-phase data values from an image sensor. A predictor value is determined for a first input block of the plurality of blocks of P-phase data values. A reconstructed first block of P-phase data values is generated, based on the P-phase data values of the first input block and the determined predictor value. The determined predictor value is then updated for a second block of P-phase data values based on the P-phase data values of the generated reconstructed first block. Compressed P-phase data values that correspond to the received plurality of blocks of P-phase data values are generated, based on the reconstructed first block and at least a reconstructed second block.

Abstract: Methods and systems for encoding video data are provided. Evolving standards for video encoding such as High Efficiency Video Coding (HEVC) standard require a significant increase in computational complexity for both inter and intra encoding. The method includes calculating an approximate cost of each of a first set of prediction modes. Then selecting a second set of prediction modes from the first set of prediction modes based on probability distributions associated with each of the modes in the first set of prediction modes, the second set having substantially fewer prediction modes than the first. A number of candidate prediction modes prior to rate distortion optimization (RDO) is reduced. Experimental results show that the proposed method provides substantial time reduction and negligible quality loss as compared to the HEVC reference.

Abstract: A system, method and apparatus to provide searching capabilities of a given queue to all of requested search patterns in a non-volatile storage unit with compressed data without decompression thereof. In one embodiment the invention provides system, method and apparatus to execute one or more queued search request of one or more search pattern for one or more non-volatile storage units without decompression of non-volatile storage units compressed data in sequence or in parallel, in order or out of order from the queue. In another embodiment the system, method, and apparatus utilizes a software storage device driver scheduler to distribute the search queues to one or more non-volatile storage units in series or in parallel, in order or out of order, in standard or virtualized operating system capable environments.

Abstract: Detailed herein are embodiments of systems, methods, and apparatuses for decompression using hardware and software. In hardware, an input buffer stores incoming input records from a compressed stream. A plurality of decoders decode at least one input record from the input buffer out output an intermediate record from the decoded data and a subset of the plurality of decoders to output a stream of literals. Finally, a reformat circuit formats an intermediate record into one of two types of tokens.

Abstract: Representative embodiments are disclosed for a rapid and highly parallel decompression of compressed executable and other files, such as executable files for operating systems and applications, having compressed blocks including run length encoded (“RLE”) data having data-dependent references. An exemplary embodiment includes a plurality of processors or processor cores to identify a start or end of each compressed block; to partially decompress, in parallel, a selected compressed block into independent data, dependent (RLE) data, and linked dependent (RLE) data; to sequence the independent data, dependent (RLE) data, and linked dependent (RLE) data from a plurality of partial decompressions of a plurality of compressed blocks, to obtain data specified by the dependent (RLE) data and linked dependent (RLE) data, and to insert the obtained data into a corresponding location in an uncompressed file.

Abstract: Techniques are described herein for storing and processing codes included in dictionary-encoded data. In an embodiment, for each respective code of a plurality of codes in the dictionary-encoded data: a plurality of bits from a first portion of the respective code is contiguously stored. One or more bits from a second portion of the respective code is stored in one or more slices. Each respective slice of the one or more slices stores a bit from the one or more bits with a corresponding bit position in the respective code. In another embodiment, a bit-vector is generated based on at least one slice by loading each respective bit of the plurality of bits into different respective partitions in a register at a bit position corresponding to the at least one slice. A plurality of codes may be reconstructed by combining the bit-vector with one or more other bit-vectors.

Abstract: The disclosure provides a sample adaptive offset (SAO) encoder. The SAO encoder includes a statistics collection (SC) block and a rate distortion optimization (RDO) block coupled to the SC block. The SC block receives a set of deblocked pixels and a set of original pixels. The SC block categorizes each deblocked pixel of the set of deblocked pixels in at least one of a plurality of band and edge categories. The SC block estimates an error in each category as difference between a deblocked pixel of the set of deblocked pixels and corresponding original pixel of the set of original pixels. The RDO block determines a set of candidate offsets associated with each category and selects a candidate offset with a minimum RD cost. The minimum RD cost is used by a SAO type block and a decision block to generate final offsets for the SAO encoder.

Abstract: A generic categorization method may include receiving interaction data on a distributed computing system operating on a plurality of computing nodes. The distributed computing system may distribute the received interaction data across the plurality of nodes. On each node, categorization rules may be applied to the interaction data via parallel processing. The results, which may include a category associated with each interaction, may be written to a distributed storage system. A user interface may allow a user to define the categorization rules and schemas of interaction data.

Abstract: A device and a method for encoding a data column are disclosed. A schema inquiry unit inquires into a schema of an original table which is a data table for performing encoding in a database in which a plurality of data tables are stored. A backup performing unit generates schema information of a backup table on the basis of the schema of the original table, generates a backup table by using the schema information of the backup table so as to copy data of the original table into the backup table, changes the original table by adding a backup column to the original table, and inactivates constraint conditions included in the changed original table so as to copy original columns included in the changed original table into the backup column. An encoding unit encodes data of an encoding target column, a column in which encoding is to be performed in the changed original table, and enters the data in each field of the original columns of the changed original table.

Abstract: In this invention, the design of the Huffman table can be done offline with a large input sequence database. The range of the quantization indices (or differential indices) for Huffman coding is identified. For each value of range, all the input signal which have the same range will be gathered and the probability distribution of each value of the quantization indices (or differential indices) within the range is calculated. For each value of range, one Huffman table is designed according to the probability. And in order to improve the bits efficiency of the Huffman coding, apparatus and methods to reduce the range of the quantization indices (or differential indices) are also introduced.

Abstract: An example method to parallelize data decompression includes adjusting a first one of initial starting positions to determine a first adjusted starting position by decoding the bitstream starting at a training position in the bitstream, the decoding including traversing the bitstream from the training position as though first data located at the training position is a valid token; and merging, by executing an instruction with the processor, first decoded data generated by decoding a first segment of the compressed data bitstream starting from the first adjusted starting position with second decoded data generated by decoding a second segment of the compressed data bitstream, the decoding of the second segment starting from a second position in the compressed data bitstream and being performed in parallel with the decoding of the first segment, and the second segment preceding the first segment in the compressed data bitstream.

Abstract: Examples of the disclosure describe user environment aware single channel acoustic noise reduction. A noisy signal received by a computing device is transformed and feature vectors of the received noisy signal are determined. The computing device accesses classification data corresponding to a plurality of user environments. The classification data for each user environment has associated therewith a noise model. A comparison is performed between the determined feature vectors and the accessed classification data to identify a current user environment. A noise level, a speech level, and a speech presence probability from the transformed noisy signal are estimated and the noise signal is reduced based on the estimates. The resulting signal is outputted as an enhanced signal with a reduced or eliminated noise signal.

Abstract: An apparatus including a Huffman decoder circuit is described. In a first embodiment, the Huffman decoder circuit includes a register file with simultaneous parallel load capability. The register file is to keep multiple copies of same decoded values in different entries of the register file. The different entries are to be addressed by respective addresses having a same leading edge encoded symbol. The parallel load capability is to simultaneously load a same decoded value for those register file addresses having a same leading edge encoded symbol. In a second embodiment, the Huffman decoder circuit includes a CAM circuit coupled to a register file, wherein respective match lines of the CAM circuit are coupled to respective entries of the register file. The CAM circuit is to keep encoded symbols. The register file is to keep decoded values of the encoded symbols.

Abstract: A system comprising a processor and a memory comprising firmware is provided. The firmware is executable by the processor to cause the processor to operate a print mechanism in accordance with a first state associated with a capability of the print mechanism, change the first state associated with the capability to a second state in response to receiving first information from an external interface, and operate the print mechanism in accordance with the second state associated with the capability.

Abstract: Efficient operations in image or video decoding. For example, a tool such as an image or video decoder receives and decodes encoded data for a picture in a bitstream. As part of the decoding, the tool adapts a multi-symbol lookup table to use in decoding of symbols then decodes the symbols using the multi-symbol lookup table, producing exactly correct results. The tool can also perform selectively truncated inverse frequency transforms. For a given block, the tool identifies upper horizontal and vertical frequencies among non-zero coefficients for the block and, based on the upper frequency values, selectively applies a simplified inverse frequency transform to transform coefficients for the block without hurting decoding quality. Using restart markers in the bitstream, the tool can organize multiple blocks of the picture as partitions. The tool decodes at least some of the partitions in parallel on a partition-by-partition basis using multiple processing cores.

Abstract: A method for generating Huffman codewords to encode a dataset includes selecting a Huffman tree type from a plurality of different Huffman tree types. Each of the Huffman tree types specifies a different range of codeword length in a Huffman tree. A Huffman tree of the selected type is produced by: determining a number of nodes available to be allocated as leaves in each level of the Huffman tree accounting for allocation of leaves in each level of the Huffman tree; allocating nodes to be leaves such that the number of nodes allocated in a given level of the Huffman tree is constrained to be no more than the number of nodes available to be allocated in the given level; and assigning the leaves to symbols of the dataset based an assignment strategy selected from a plurality of assignment strategies to produce symbol codeword information.

Abstract: A method for determining the bandwidth of an incoming frame in a wireless local area network (WLAN), includes the following steps, executed at least by a processor, upon reception of a first plurality of samples representative of a first signal of the frame received at a primary WLAN channel, and of a second plurality of samples of the frame representative of a second signal of the frame received at a secondary WLAN channel: computing at least a correlation of a sample among the first plurality of samples with a sample among the second plurality of samples; if the correlation exceeds a threshold then setting a receiver mode to a first bandwidth otherwise setting a receiver mode to a second bandwidth. A device for setting the bandwidth of a receiver for a wireless local area network and a system integrating such device are also described.

Abstract: The present disclosure relates to an add and decode hardware logic circuit for adding two n bit inputs, A and B. A series of n logic stages are each configured to perform a first operation of propagating a result of a preceding stage on the condition that the sum of A[m] and B[m] is equal to 0, wherein 0<=m<n, perform a second operation of performing a bitwise left shift by 2m of the result of the preceding stage on the condition that the sum of A[m] and B[m] is equal to 1, or perform a third operation of performing a bitwise left shift by 2m+1 of the result of the preceding stage on the condition that the sum of A[m] and B[m] is equal to 2. An output at the last stage provides a decoded sum of the inputs A and B.

Abstract: A video decoding apparatus includes a decoder to decode division information related to dividing a current block into subblocks, and reconstruct transform coefficients of each of the subblocks identified by the division information, and thereby generate transformed residual subblocks; an inverse transformer to inverse-transform each of the transformed residual subblocks, and thereby generate residual subblocks; a predictor to generate predicted subblocks by intra-predicting each of the subblocks; an adder to reconstruct the current block by adding the predicted subblocks to the residual subblocks corresponding thereto; and a first filter to perform deblocking-filtering on boundaries between the subblocks in a reconstructed picture including the reconstructed current block.

Abstract: According to an example, an original image is divided into image blocks according to a preset size, at least one pixel is overlapped between adjacent image blocks, a target image block is obtained after performing reduction processing for each of the image blocks according to a reduction factor, coordinates of the target image block are obtained according to the reduction factor and coordinates of the image block; and the target image blocks are combined according to the coordinates of the target image blocks.

Abstract: Systems, methods, and computer readable storage mediums for optimistically managing compressed data in a storage system. When possible, multiple input blocks are compressed into a buffer and stored in a single physical block on a storage device. The metadata of the multiple input blocks can be managed separately. A fingerprint of the compressed buffer can be generated and used as an index to the single physical block. Alternatively, fingerprints of the uncompressed input blocks can be generated, and reference counts can be maintained to track the number of input blocks which reference the compressed buffer.

Abstract: A method of cryptographic processing of data (X), in particular a method protected against fault injection attacks, and an associated device. The processing includes at least one transformation (100, 1001-1006) of an input data item (s) into a result data item (s?). In this case the method includes a step (E204) of verifying the transformation including the following steps: obtaining (E206) a first data item (DV(s?)) that is compressed by applying a compression operation (110, MDV, ADV) to the result data item (s?); obtaining (E208) a second compressed data item (DV(s)) that is compressed by applying the compression operation (110, MDV, ADV) to the input data item (s); determining (E210) a verification data item (DV(s)?) by applying the transformation (100, 1001-1006) to the second compressed data item (DV(s)) and; comparing (E212) the verification data item and the first compressed data item.

Abstract: A computer-readable recording medium stores a program causing a computer to determine the size of an applied 2N-branch non-contact Huffman tree depending on where in a range the total number of types (X) of character information groups exists. The size of the 2N-branch non-contact Huffman tree has the maximum number of branches, 2N. The radicand N is an upper limit of the length of a compression code. Thus, when the size of the 2N-branch non-contact Huffman tree is determined, the radicand (N) may be determined depending on the total number of types (X) of character information groups. Specifically, when the total number of types (X) of character information groups is 2x?2<X?2x?1, if the maximum number of branches (2N) is at least 2x?1, a Huffman tree can be established. To minimize the size, N=x?1 may be adopted. Further, when the total number of types (X) of character information groups is 2x?1<X?2x, if the maximum number of branches (2N) is at least 2x, a Huffman tree can be established.

Abstract: When a block (MB22) of which motion vector is referred to in the direct mode contains a plurality of motion vectors, 2 motion vectors MV23 and MV24, which are used for inter picture prediction of a current picture (P23) to be coded, are determined by scaling a value obtained from averaging the plurality of motion vectors or selecting one of the plurality of the motion vectors.