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Diffstat (limited to 'doc/lziprecover.texinfo')
| -rw-r--r-- | doc/lziprecover.texinfo | 35 |
1 files changed, 22 insertions, 13 deletions
diff --git a/doc/lziprecover.texinfo b/doc/lziprecover.texinfo index 22eea8a..872abb4 100644 --- a/doc/lziprecover.texinfo +++ b/doc/lziprecover.texinfo @@ -6,8 +6,8 @@ @finalout @c %**end of header -@set UPDATED 24 February 2012 -@set VERSION 1.13 +@set UPDATED 27 February 2013 +@set VERSION 1.14-rc1 @dircategory Data Compression @direntry @@ -44,7 +44,7 @@ This manual is for Lziprecover (version @value{VERSION}, @value{UPDATED}). @end menu @sp 1 -Copyright @copyright{} 2009, 2010, 2011, 2012 Antonio Diaz Diaz. +Copyright @copyright{} 2009, 2010, 2011, 2012, 2013 Antonio Diaz Diaz. This manual is free documentation: you have unlimited permission to copy, distribute and modify it. @@ -155,7 +155,9 @@ Keep (don't delete) input files during decompression. @item -l @itemx --list Print total file sizes and ratios. The values produced are correct even -for multi-member files. +for multi-member files. Use it together with @samp{-v} to see +information about the members in the file. + @item -m @itemx --merge @@ -245,6 +247,11 @@ Table of SI and binary prefixes (unit multipliers): @chapter File Format @cindex file format +Perfection is reached, not when there is no longer anything to add, but +when there is no longer anything to take away.@* +--- Antoine de Saint-Exupery + +@sp 1 In the diagram below, a box like this: @verbatim +---+ @@ -280,15 +287,16 @@ All multibyte values are stored in little endian order. A four byte string, identifying the lzip format, with the value "LZIP". @item VN (version number, 1 byte) -Just in case something needs to be modified in the future. Valid values -are 0 and 1. Version 0 files are deprecated. They can contain only one -member and lack the @samp{Member size} field. +Just in case something needs to be modified in the future. 1 for now. @item DS (coded dictionary size, 1 byte) -Bits 4-0 contain the base 2 logarithm of the base dictionary size.@* -Bits 7-5 contain the number of "wedges" to substract from the base -dictionary size to obtain the dictionary size. The size of a wedge is -(base dictionary size / 16).@* +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).@* +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.@* Valid values for dictionary size range from 4KiB to 512MiB. @item Lzma stream @@ -302,8 +310,9 @@ CRC of the uncompressed original data. Size of the uncompressed original data. @item Member size (8 bytes) -Total size of the member, including header and trailer. This facilitates -safe recovery of undamaged members from multi-member files. +Total size of the member, including header and trailer. This field acts +as a distributed index, and facilitates safe recovery of undamaged +members from multi-member files. @end table |