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Diffstat (limited to 'doc')
| -rw-r--r-- | doc/clzip.1 | 2 | ||||
| -rw-r--r-- | doc/clzip.info | 50 | ||||
| -rw-r--r-- | doc/clzip.texi | 43 |
3 files changed, 46 insertions, 49 deletions
diff --git a/doc/clzip.1 b/doc/clzip.1 index d351c01..cfc9050 100644 --- a/doc/clzip.1 +++ b/doc/clzip.1 @@ -1,5 +1,5 @@ .\" DO NOT MODIFY THIS FILE! It was generated by help2man 1.46.1. -.TH CLZIP "1" "February 2015" "clzip 1.7-pre1" "User Commands" +.TH CLZIP "1" "May 2015" "clzip 1.7-rc1" "User Commands" .SH NAME clzip \- reduces the size of files .SH SYNOPSIS diff --git a/doc/clzip.info b/doc/clzip.info index 848adc2..b66195e 100644 --- a/doc/clzip.info +++ b/doc/clzip.info @@ -11,7 +11,7 @@ File: clzip.info, Node: Top, Next: Introduction, Up: (dir) Clzip Manual ************ -This manual is for Clzip (version 1.7-pre1, 26 February 2015). +This manual is for Clzip (version 1.7-rc1, 23 May 2015). * Menu: @@ -38,8 +38,7 @@ File: clzip.info, Node: Introduction, Next: Algorithm, Prev: Top, Up: Top Clzip is a lossless data compressor with a user interface similar to the one of gzip or bzip2. Clzip is about as fast as gzip, compresses most files more than bzip2, and is better than both from a data recovery -perspective. Clzip is a clean implementation of the LZMA -(Lempel-Ziv-Markov chain-Algorithm) "algorithm". +perspective. Clzip uses the lzip file format; the files produced by clzip are fully compatible with lzip-1.4 or newer, and can be rescued with @@ -136,7 +135,7 @@ multivolume compressed tar archives. Clzip is able to compress and decompress streams of unlimited size by automatically creating multi-member output. The members so created are -large, about 64 PiB each. +large, about 2 PiB each. File: clzip.info, Node: Algorithm, Next: Invoking clzip, Prev: Introduction, Up: Top @@ -144,13 +143,14 @@ File: clzip.info, Node: Algorithm, Next: Invoking clzip, Prev: Introduction, 2 Algorithm *********** -There is no such thing as a "LZMA algorithm"; it is more like a "LZMA -coding scheme". For example, the option '-0' of lzip uses the scheme in -almost the simplest way possible; issuing the longest match it can find, -or a literal byte if it can't find a match. Inversely, a much more -elaborated way of finding coding sequences of minimum price than the one -currently used by lzip could be developed, and the resulting sequence -could also be coded using the LZMA coding scheme. +In spite of its name (Lempel-Ziv-Markov chain-Algorithm), LZMA is not a +concrete algorithm; it is more like "any algorithm using the LZMA coding +scheme". For example, the option '-0' of lzip uses the scheme in almost +the simplest way possible; issuing the longest match it can find, or a +literal byte if it can't find a match. Inversely, a much more elaborated +way of finding coding sequences of minimum size than the one currently +used by lzip could be developed, and the resulting sequence could also +be coded using the LZMA coding scheme. Clzip currently implements two variants of the LZMA algorithm; fast (used by option -0) and normal (used by all other compression levels). @@ -227,7 +227,7 @@ The format for running clzip is: '--member-size=BYTES' Set the member size limit to BYTES. A small member size may degrade compression ratio, so use it only when needed. Valid values - range from 100 kB to 64 PiB. Defaults to 64 PiB. + range from 100 kB to 2 PiB. Defaults to 2 PiB. '-c' '--stdout' @@ -406,14 +406,12 @@ additional information before, between, or after them. now. 'DS (coded dictionary size, 1 byte)' - Lzip divides the distance between any two powers of 2 into 8 - equally spaced intervals, named "wedges". The dictionary size is - calculated by taking a power of 2 (the base size) and substracting - from it a number of wedges between 0 and 7. The size of a wedge is - (base_size / 16). + The dictionary size is calculated by taking a power of 2 (the base + size) and substracting from it a fraction between 0/16 and 7/16 of + the base size. Bits 4-0 contain the base 2 logarithm of the base size (12 to 29). - Bits 7-5 contain the number of wedges (0 to 7) to substract from - the base size to obtain the dictionary size. + Bits 7-5 contain the numerator of the fraction (0 to 7) to + substract from the base size to obtain the dictionary size. Example: 0xD3 = 2^19 - 6 * 2^15 = 512 KiB - 6 * 32 KiB = 320 KiB Valid values for dictionary size range from 4 KiB to 512 MiB. @@ -547,13 +545,13 @@ Concept index Tag Table: Node: Top210 -Node: Introduction903 -Node: Algorithm6200 -Node: Invoking clzip8963 -Node: File format14514 -Node: Examples17046 -Node: Problems19015 -Node: Concept index19541 +Node: Introduction897 +Node: Algorithm6100 +Node: Invoking clzip8930 +Node: File format14479 +Node: Examples16881 +Node: Problems18850 +Node: Concept index19376 End Tag Table diff --git a/doc/clzip.texi b/doc/clzip.texi index 01f5f39..a74ec6f 100644 --- a/doc/clzip.texi +++ b/doc/clzip.texi @@ -6,8 +6,8 @@ @finalout @c %**end of header -@set UPDATED 26 February 2015 -@set VERSION 1.7-pre1 +@set UPDATED 23 May 2015 +@set VERSION 1.7-rc1 @dircategory Data Compression @direntry @@ -58,8 +58,7 @@ to copy, distribute and modify it. Clzip is a lossless data compressor with a user interface similar to the one of gzip or bzip2. Clzip is about as fast as gzip, compresses most files more than bzip2, and is better than both from a data recovery -perspective. Clzip is a clean implementation of the LZMA -(Lempel-Ziv-Markov chain-Algorithm) "algorithm". +perspective. Clzip uses the lzip file format; the files produced by clzip are fully compatible with lzip-1.4 or newer, and can be rescued with lziprecover. @@ -162,23 +161,24 @@ multivolume compressed tar archives. Clzip is able to compress and decompress streams of unlimited size by automatically creating multi-member output. The members so created are -large, about 64 PiB each. +large, about 2 PiB each. @node Algorithm @chapter Algorithm @cindex algorithm -There is no such thing as a "LZMA algorithm"; it is more like a "LZMA -coding scheme". For example, the option '-0' of lzip uses the scheme in -almost the simplest way possible; issuing the longest match it can find, -or a literal byte if it can't find a match. Inversely, a much more -elaborated way of finding coding sequences of minimum price than the one -currently used by lzip could be developed, and the resulting sequence -could also be coded using the LZMA coding scheme. +In spite of its name (Lempel-Ziv-Markov chain-Algorithm), LZMA is not a +concrete algorithm; it is more like "any algorithm using the LZMA coding +scheme". For example, the option '-0' of lzip uses the scheme in almost +the simplest way possible; issuing the longest match it can find, or a +literal byte if it can't find a match. Inversely, a much more elaborated +way of finding coding sequences of minimum size than the one currently +used by lzip could be developed, and the resulting sequence could also +be coded using the LZMA coding scheme. -Clzip currently implements two variants of the LZMA algorithm; fast (used -by option -0) and normal (used by all other compression levels). +Clzip currently implements two variants of the LZMA algorithm; fast +(used by option -0) and normal (used by all other compression levels). The high compression of LZMA comes from combining two basic, well-proven compression ideas: sliding dictionaries (LZ77/78) and markov models (the @@ -245,7 +245,7 @@ clzip [@var{options}] [@var{files}] Clzip supports the following options: -@table @samp +@table @code @item -h @itemx --help Print an informative help message describing the options and exit. @@ -258,7 +258,7 @@ Print the version number of clzip on the standard output and exit. @itemx --member-size=@var{bytes} Set the member size limit to @var{bytes}. A small member size may degrade compression ratio, so use it only when needed. Valid values -range from 100 kB to 64 PiB. Defaults to 64 PiB. +range from 100 kB to 2 PiB. Defaults to 2 PiB. @item -c @itemx --stdout @@ -441,13 +441,12 @@ A four byte string, identifying the lzip format, with the value "LZIP" Just in case something needs to be modified in the future. 1 for now. @item DS (coded dictionary size, 1 byte) -Lzip divides the distance between any two powers of 2 into 8 equally -spaced intervals, named "wedges". The dictionary size is calculated by -taking a power of 2 (the base size) and substracting from it a number of -wedges between 0 and 7. The size of a wedge is (base_size / 16).@* +The dictionary size is calculated by taking a power of 2 (the base size) +and substracting from it a fraction between 0/16 and 7/16 of the base +size.@* Bits 4-0 contain the base 2 logarithm of the base size (12 to 29).@* -Bits 7-5 contain the number of wedges (0 to 7) to substract from the -base size to obtain the dictionary size.@* +Bits 7-5 contain the numerator of the fraction (0 to 7) to substract +from the base size to obtain the dictionary size.@* Example: 0xD3 = 2^19 - 6 * 2^15 = 512 KiB - 6 * 32 KiB = 320 KiB@* Valid values for dictionary size range from 4 KiB to 512 MiB. |