Method and system for compression and decompression using variable-sized offset and length fields
US5933104A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 22, 1995 |
| Grant date | Aug 3, 1999 |
| Priority date | — |
| Expiry date | Nov 22, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M7/3086
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A computer system includes a compression engine for compressing a decompressed sequence of data to produce a compressed sequence of data. The compression engine encodes each piece of data in the decompressed sequence of data as either a portion of a copy token or as a literal token. Tokens are grouped together into groups of up to 8 tokens and a bitmap holding 8 bits is provided to identify the respective tokens as either copy tokens or literal tokens. The copy tokens encode sub-sequences of data that have previously occurred in the decompressed data sequence. Each copy token is of a like size but includes a variable-sized offset field for encoding an offset between a current occurrence of a sub-sequence of data and a previous occurrence of a sub-sequence of data. The offset field is variable-sized to encode the offset in a minimal number of bits. The computer system also includes a decompression engine for decompressing data sequences that have been compressed using the compression engine.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.