A data compression method includes inputting a data sequence that includes first data strings and second data strings alternating with each other, each of the first data strings containing one or more first data all of which have a same predetermined value, each of the second data strings containing one or more second data different from the predetermined value, determining first numbers and second numbers from a beginning of the input data sequence sequentially, each of the first numbers being a number of the first data in a respective one of the first data strings, and each of the second numbers being a number of the second data in a respective one of the second data strings, and arranging the first numbers, the second numbers, and the second data strings in a cyclic manner to generate compressed data.

Techniques are disclosed for compressing data. The techniques include identifying, in data to be compressed, a first set of values, wherein the first set of values include a first number of two or more consecutive identical non-zero values; including, in compressed data, a first control value indicating the first number of non-zero values and a first data item corresponding to the consecutive identical non-zero values; identifying, in the data to be compressed, a second value having an exponent value included in a defined set of exponent values; including, in the compressed data, a second control value indicating the exponent value and a second data item corresponding to a portion of the second value other than the exponent value; and including, in the compressed data, a third control value indicating a third set of one or more consecutive zero values in the data to be compressed.

Encoded (compressed) data in an encoded block format output by a data encoder, having an input including digital input elements from an input stream or file that are divided into blocks that contain Nb individual data elements per block. The encoded block format can include an index that, during decoding, supports random access. A decoder can losslessly decode the encoded block format. Each encoded block contains a header and a payload. The header specifies the unique characteristics of elements used by the payload to describe single-Byte or multi-Byte events that occurred in the input block. The encoded block format is generated by one or more block-oriented encoders (compressors). Blocks having the encoded block format may be consumed by one or more decoders (decompressors) that regenerate Nb elements from each decoded (uncompressed) block.

Encoded (compressed) data in an encoded block format output by a data encoder, having an input including digital input elements from an input stream or file that are divided into blocks that contain Nb individual data elements per block. The encoded block format can include an index that, during decoding, supports random access. A decoder can losslessly decode the encoded block format. Each encoded block contains a header and a payload. The header specifies the unique characteristics of elements used by the payload to describe single-Byte or multi-Byte events that occurred in the input block. The encoded block format is generated by one or more block-oriented encoders (compressors). Blocks having the encoded block format may be consumed by one or more decoders (decompressors) that regenerate Nb elements from each decoded (uncompressed) block.

A data packer is provided that is configured to form a bit stream for forwarding a plurality of values to memory. The bit stream includes the plurality of values and respective prefixes for identifying the values and the data packer is configured to insert the prefixes at predetermined boundaries in the bit stream, such that a prefix for identifying one value is inserted between bits that define a value identified by another prefix. A data unpacker is also provided that is configured to unpack a bit stream that comprises a plurality of values and respective prefixes for identifying those values that are located at predetermined boundaries in the bit stream, such that a prefix for identifying one value is inserted between bits that define a value identified by another prefix. The data unpacker is configured to identify a prefix at a predetermined boundary in the bit stream and determine, in dependence on that prefix and the predetermined boundaries, a location of the next prefix in the bit stream.

A data packer is provided that is configured to form a bit stream for forwarding a plurality of values to memory. The bit stream includes the plurality of values and respective prefixes for identifying the values and the data packer is configured to insert the prefixes at predetermined boundaries in the bit stream, such that a prefix for identifying one value is inserted between bits that define a value identified by another prefix. A data unpacker is also provided that is configured to unpack a bit stream that comprises a plurality of values and respective prefixes for identifying those values that are located at predetermined boundaries in the bit stream, such that a prefix for identifying one value is inserted between bits that define a value identified by another prefix. The data unpacker is configured to identify a prefix at a predetermined boundary in the bit stream and determine, in dependence on that prefix and the predetermined boundaries, a location of the next prefix in the bit stream.

Systems, apparatus and methods are provided for compressing data. An exemplary method may comprise interleaving one or more literal length fields with one or more literal fields to an output. The literal fields may contain a first data segment literally copied to the output, and each of the one or more literal length fields may contain a value representing a length of a succeeding literal field. The method may further comprise determining a second data segment being matched to a previously literally copied sequence of data and a match position and writing to the output one or more match length fields and a match position field containing the match position. The literal length fields may contain a total length of the first data segment and the match length fields may contain a total length of the second data segment.

An encoding/decoding technique is provided with which encoding can be performed using a small average number of bits even for a sequence of integer values including small non-zero values and having a distribution heavily biased toward small values. The present invention includes an integer encoding part 110 that, with respect to an inputted sequence of non-negative integer values x_n, n{1, 2, . . . , N} (hereinafter referred to as an integer sequence), obtains a 1-bit code as a code corresponding to a run of integer values 0 of length L, a predetermined number which satisfies 2L2.sup.K1, which is included in the integer sequence and obtains a (Kx_n)-bit or (Kx_n+1)-bit code as a code corresponding to a set of a run of integer values 0 of length from 0 to L1 and one non-zero integer value x_n included in the integer sequence, where K is assumed to be an integer equal to or larger than 2.

Methods, devices and systems enhance compression and decompression of data blocks of data values by selecting the best suited compression method and device among two or a plurality of compression methods and devices, which are combined together and which said compression methods and devices compress effectively data values of particular data types; said best suited compression method and device is selected using as main selection criterion the dominating data type in a data block by predicting the data types within said data block.

Methods, devices and systems enhance compression and decompression of data blocks of data values by selecting the best suited compression method and device among two or a plurality of compression methods and devices, which are combined together and which said compression methods and devices compress effectively data values of particular data types; said best suited compression method and device is selected using as main selection criterion the dominating data type in a data block by predicting the data types within said data block.