Method for reducing data expansion during data compression

摘要

A method of reducing data expansion during data compression is provided that allows the coding scheme used to compress data to be swapped between two or more coding schemes. Specifically, a coding window is provided that allows analysis of the compression potential of data within the coding window. The data within the coding window then is analyzed to determine the compression potential of the data. If the compression potential of the data exceeds a first predetermined value, the coding scheme used to compress the data within the coding window is swapped from one coding scheme to another. Preferably the first predetermined value is programmable and is related to the bit cost required to swap back and forth between coding schemes. The two preferred coding schemes are ALDC Lempel-Ziv 1 coding and a pass-through coding scheme wherein raw data is passed unencoded.