Data compression method of individual sequences of strings of a data stream based on a dictionary and device for performing the same

摘要

A method for data compression of individual sequences in a data stream comprising the step of initializing a dictionary consisting of a set of strings with an index or a codeword for each of said strings and including all possible strings of length 1. Each current string of the dictionary is stored in a memory storage (300) which is addressed by the current index corresponding to the current string. The organization of the memory is such that, for each index used as an address, the memory storage returns a data which comprises: a first field defining the index of the last character of the string being stored; a second field defining the index of the string (SON) that comprises said current string plus an additional character and being the first string that chronologically follows the creation of said current string; and a third field defining the index of the string (BROTHER) which appears within the dictionary after the creation of the current string and which has the same common characters than said current string except for the last; and a fourth field defining the index of the string (PARENT) that comprises all the characters of said current string except the last. Therefore, the different fields stored within the memory represents pointers which characterize the relationship between the different strings which are stored in the dictionary. Since the memory is arranged in accordance with the tree structure of this dictionary, the different access to the memory are made easier, thus decreasing the processing resources. The method is particularly embodied by use of a specific compression processor which has specific set of registers which provides a direct access to the different fields of the data stored within the memory.