Data compression apparatus with shift register search means
US5003307A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 6, 1989 |
| Grant date | Mar 26, 1991 |
| Priority date | — |
| Expiry date | Oct 6, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M7/46
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An apparatus and method are disclosed for converting an input data character stream into a variable length encoded data stream in a data compression system. The data compression system includes a shift register means. The shift register means has a plurality of entries and each entry of the shift register means is for storing a data character of the input data stream. The method for converting the input data character stream includes the following steps. Performing a search in the shift register means for a data string which matches the input data string. The step for performing the search includes the steps of broadcasting each input data character of the input data stream to each entry of the shift register means and comparing each input data character simultaneously with the previously stored contents of each entry of said shift register means. If the matching data string is found within the shift register means, the next step includes encoding the longest matching data string by appending to the encoded data stream a tag indicating the matching data string and a string substitution code. If the matching data string is not found within the shift register means, the next step inc…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.