| 摘要 |
Disclosed are a method and apparatus for switching between lossless data compression modes, and the switching indicated by at least one multibit mode switch character. The binary format input data is received and a FIFO determination of the compression efficiency of the input data under each mode is made on an ongoing basis. The ongoing basis may be for each compressed code word or more. A FIFO comparison of the compression efficiencies under each mode are made, and the modes for compressing the input data are switched only upon the comparison, or accumulated comparisons, indicating the compression efficiency of the present mode is less than the compression efficiency of the other mode by a threshold value, the threshold value directly related to the number of bits in the multibit mode switch character. One or both of the data compression modes may comprise a Lempel-Ziv compression, such as ALDC (LZ-1 derivative) or DCLZ (LZ-2 derivative), for compressing the input data into variable sized tokens, and the FIFO compression efficiency may be determined based on the bit length of each variable sized token.
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