Compressing data using an encoding table

A device for compressing a data stream, comprising:

• a transformation front end block configured to transform a data stream into a transformed data stream of referencing symbols and other data elements, the referencing symbols representing a data sequence in the data stream which is identical to a data sequence in a reference data block and being pointers to the identical data sequence in the reference data block;
• and
• an encoding back end block configured to encode the referencing symbols by replacing them with codewords according to an encoding scheme;
• wherein 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 replacing the referencing symbols, wherein the location of the at least one control symbol within the transformed data stream defines the end of the respective portion of the transformed data stream;
• and
• wherein the encoding back end block is configured such that the encoding scheme provides that at least one codeword associated to one of the referencing symbols is longer than the codeword associated to the control symbol.

A method for generating a representation of an encoding scheme for use in the compression of a data stream into a compressed data stream, wherein the encoding scheme associates codewords to each of one or more referencing symbols and to at least one control symbol, wherein each referencing symbol indicates a replaced data sequence in the compressed data stream and wherein the control symbols indicate a change between the referencing symbols and other data elements in the compressed data stream, wherein the representation of the encoding scheme is generated by:

• providing a set of the occurrence frequencies of each of the referencing symbols;
• adding a freely selected frequency to the set of the occurrence frequencies associated with the control symbol;
• forming the encoding scheme using a Huffman encoding algorithm, so that to each referencing symbol a codeword is associated according to its frequency of occurrence;
• and
• iteratively adapting the frequency of occurrence of the control symbol until the codeword associated to the control symbol has a desired length.