US5874908A
Expired / Lapsed
US
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Method and apparatus for encoding Lempel-Ziv 1 variants
Assignee: International Business Machines Corp
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Filing: 1997-09-19
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Granted: 1999-02-23
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Expires: 2017-09-19
Abstract
Abstract A method for encoding an input data stream of source symbols to produce an output sequence of pointers is disclosed. A LITERAL string in an input data stream is first loaded into a history-buffer. A value of a history-buffer pointer is copied to a register to indicate a starting position of the LITERAL string within the history-buffer. A counter is incremented for each subsequent LITERAL symbol from the input data stream. Then, the LITERAL string and each subsequent LITERAL symbol from the input data stream is encoded utilizing a value within the register and a value within the counter as a LITERAL -- POINTER. Finally, the LITERAL -- POINTER is outputted from a data compressor.
Inventors
- 👤 David John Craft
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 15:50
CPC Classifications
H; H03; H03M; H03M7/00; H03M7/30; H03M7/46; G; G06; G06T; G06T9/00; G06T9/005; H03M7/3084; H03M7/3086
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
121 words
A method for encoding an input data stream of source symbols to produce an output sequence of pointers by utilizing a history-buffer within a data compressor, said method comprising the steps of: loading a LITERAL string in said input data stream to said history-buffer; copying a value of a history-buffer pointer to a register to indicate a starting position of a LITERAL string within said history-buffer; incrementing a counter for each subsequent LITERAL symbol from said input data stream; encoding said LITERAL string and each said subsequent LITERAL symbol from said input data stream utilizing a value within said register and a value within said counter as a LITERAL -- POINTER; and outputting said LITERAL -- POINTER from said data compressor.
Claim 2
Independent Claim
121 words
A method for encoding an input data stream of source symbols to produce an output sequence of pointers by utilizing a history-buffer within a data compressor, said method comprising the steps of: loading a LITERAL string in said input data stream to said history-buffer; copying a value of a history-buffer pointer to a register to indicate a starting position of a LITERAL string within said history-buffer; incrementing a counter for each subsequent LITERAL symbol from said input data stream; encoding said LITERAL string and each said subsequent LITERAL symbol from said input data stream utilizing a value within said register and a value within said counter as a LITERAL -- POINTER; and outputting said LITERAL -- POINTER from said data compressor.
Claim 3
Dependent Claim
36 words
The method for encoding an input data stream of source symbols according to claim 1, wherein said LITERAL -- POINTER includes a SYMBOL -- COUNT code followed by a corresponding number of LITERAL -- DATA symbols.
Claim 4
Dependent Claim
28 words
The method for encoding an input data stream of source symbols according to claim 1, wherein said SYMBOL -- COUNT can be of fixed length or variable length.
Claim 5
Dependent Claim
27 words
The method for encoding an input data stream of source symbols according to claim 1, wherein said counter can count up to the size of said history-buffer.
Claim 6
Dependent Claim
126 words
A data compressor for encoding an input data stream of source symbols to produce an output sequence of pointers by utilizing a history-buffer, said data compressor comprising: means for loading a LITERAL string in said input data stream to said history-buffer; means for copying a value of a history-buffer pointer to a register to indicate a starting position of a LITERAL string within said history-buffer; means for incrementing a counter for each subsequent LITERAL symbol from said input data stream; means for encoding said LITERAL string and each said subsequent LITERAL symbol from said input data stream utilizing a value within said register and a value within said counter as a LITERAL -- POINTER; and means for outputting said LITERAL -- POINTER from said data compressor.
Claim 7
Dependent Claim
126 words
A data compressor for encoding an input data stream of source symbols to produce an output sequence of pointers by utilizing a history-buffer, said data compressor comprising: means for loading a LITERAL string in said input data stream to said history-buffer; means for copying a value of a history-buffer pointer to a register to indicate a starting position of a LITERAL string within said history-buffer; means for incrementing a counter for each subsequent LITERAL symbol from said input data stream; means for encoding said LITERAL string and each said subsequent LITERAL symbol from said input data stream utilizing a value within said register and a value within said counter as a LITERAL -- POINTER; and means for outputting said LITERAL -- POINTER from said data compressor.
Claim 8
Dependent Claim
28 words
The data compressor according to claim 5, wherein said LITERAL -- POINTER includes a SYMBOL -- COUNT code followed by a corresponding number of LITERAL -- DATA symbols.
Claim 9
Dependent Claim
20 words
The data compressor according to claim 5, wherein said SYMBOL -- COUNT can be of fixed length or variable length.
Claim 10
Dependent Claim
19 words
The data compressor according to claim 5, wherein said counter can count up to the size of said history-buffer.
Claim 11
Dependent Claim
138 words
A program software product for encoding an input data stream of source symbols to produce an output sequence of pointers by utilizing a history-buffer, said program software product comprising: program code means for loading a LITERAL string in said input data stream to said history-buffer; program code means for copying a value of a history-buffer pointer to a register to indicate a starting position of a LITERAL string within said history-buffer; program code means for incrementing a counter for each subsequent LITERAL symbol from said input data stream; program code means for encoding said LITERAL string and each said subsequent LITERAL symbol from said input data stream utilizing a value within said register and a value within said counter as a LITERAL -- POINTER; and program code means for outputting said LITERAL -- POINTER from said data compressor.
Claim 12
Dependent Claim
138 words
A program software product for encoding an input data stream of source symbols to produce an output sequence of pointers by utilizing a history-buffer, said program software product comprising: program code means for loading a LITERAL string in said input data stream to said history-buffer; program code means for copying a value of a history-buffer pointer to a register to indicate a starting position of a LITERAL string within said history-buffer; program code means for incrementing a counter for each subsequent LITERAL symbol from said input data stream; program code means for encoding said LITERAL string and each said subsequent LITERAL symbol from said input data stream utilizing a value within said register and a value within said counter as a LITERAL -- POINTER; and program code means for outputting said LITERAL -- POINTER from said data compressor.
Claim 13
Dependent Claim
45 words
The program software product for encoding an input data stream of source symbols to produce an output sequence of pointers according to claim 9, wherein said LITERAL -- POINTER includes a SYMBOL -- COUNT code followed by a corresponding number of LITERAL -- DATA symbols.
Claim 14
Dependent Claim
37 words
The program software product for encoding an input data stream of source symbols to produce an output sequence of pointers according to claim 9, wherein said SYMBOL -- COUNT can be of fixed length or variable length.
Claim 15
Dependent Claim
36 words
The program software product for encoding an input data stream of source symbols to produce an output sequence of pointers according to claim 9, wherein said counter can count up to the size of said history-buffer.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2002-02-22 | 2002-08-24 | 2003-02-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-02-22 | 2006-08-24 | 2007-02-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-02-22 | 2010-08-24 | 2011-02-23 | $7700.00 | Window Closed / Lapsed |