Device and method for an improved compression of digital data, comprises input of two data flows and coding of symbols by use of table and by selecting redundant words

摘要

A coder for compressing digital data comprises an input for a first data flow (SH), an input for a second data flow (SL), a coding table containing a correspondence between the symbols of the first data flow and the code words, or for certain symbols several redundant words corresponding to the same symbol; and a processing module for coding the symbols of the first data flow after the table by selecting among the redundant words as a function of a part of at least the second data flow. The code words are of a fixed length. The processing module comprises a function for computing the current capacity of multiplexing of the first data flow (SH) by use of the coding table, and a function for extracting a multiplexed part in the second data flow (SL) to be carried by the redundant words. The coder (claimed) comprises a transformation of a binary flow into a flow of multi-valued variable. The second data flow is preliminary encoded. The rest of the second data flow is concatenated to the transmitted data. A decoder (claimed) effects operations inverse to those of the coder. The compression method (claimed) comprises the steps of establishing the coding table, and of coding the symbols of the first data flow after the table. A decompression method (claimed) comprises steps reciprocal to those of the compression method.