Variable LZX window sizes

[wimlib] / doc / imagex-optimize.1.in

diff --git a/doc/imagex-optimize.1.in b/doc/imagex-optimize.1.in
index 8ccbaa7dcb5c2a7c5957f20fb976dc28eace2457..c1cf5cb1290a0ea004e526f6340b6558fd09a9b4 100644 (file)
--- a/doc/imagex-optimize.1.in
+++ b/doc/imagex-optimize.1.in
@@ -1,4 +1,4 @@
-.TH WIMLIB-IMAGEX "1" "October 2013" "@IMAGEX_PROGNAME@ @VERSION@" "User Commands"
+.TH WIMLIB-IMAGEX "1" "December 2013" "@IMAGEX_PROGNAME@ @VERSION@" "User Commands"
 .SH NAME
 @IMAGEX_PROGNAME@-optimize \- Optimize a WIM archive
 .SH SYNOPSIS
@@ -33,20 +33,29 @@ better job than the program that wrote the original file.  A side effect of this
 is that every stream in the original WIM will be checksummed, so this can help
 verify that the WIM is intact (equivalent to applying all the images from it).
 .IP ""
-Note: as mentioned in the README, wimlib generally provides a slightly better
-XPRESS compression ratio than Microsoft's software, while it generally provides
-a slightly worse LZX compression ratio than Microsoft's software.  So, you may
-not want to specify \fB--recompress\fR when optimizing a LZX-compressed WIM
-created on Windows with Microsoft's ImageX.
+Note: as of wimlib v1.5.3, wimlib's LZX compressor usually achieves the same or
+better compression than Microsoft's, but is slightly slower.
 .TP
-\fB--compress-slow\fR
-With \fB--recompress\fR: Spend even more time compressing the data in order to
-achieve a higher compression ratio.  Currently, this only has an effect with LZX
-("maximum") compression.  Depending on the data, compressing with this option
-will take around 10 to 15 times longer and produce a LZX-compressed WIM about 1%
-to 5% smaller than one produced with the default LZX compressor.  Depending on
-the data, the resulting WIM may be approximately the same size (typically no
-more than 0.4% different) as a LZX-compressed WIM produced by WIMGAPI.
+\fB--recompress-slow\fR, \fB--compress-slow\fR
+Spend even more time compressing the data in order to achieve a more optimal
+compression ratio.  Compared to the default \fB--recompress\fR, this will make
+compression about twice as slow and will increase the compression ratio by maybe
+1%, depending on the data.  This option implies \fB--recompress\fR and
+\fB--compress\fR=\fImaximum\fR (recompress using LZX compression).
+.TP
+\fB--compress\fR=\fITYPE\fR
+Recompress the WIM file using the specified compression type.  \fITYPE\fR may be
+"none", "fast", or "maximum".  This implies \fB--recompress\fR.
+.TP
+\fB--chunk-size\fR=\fISIZE\fR
+Set the WIM compression chunk size to \fISIZE\fR.  Using this option is not
+recommended because WIM chunk sizes other than the default of 32768 are not
+supported by Microsoft's software.  But if you decide to use this option
+regardless, you can choose a chunk size that is any power of 2 greater than or
+equal to 2^15 (32768) up to 2^21 (2097152) for LZX ("maximum") compression or
+2^26 (67108864) for XPRESS ("fast") compression.  Larger chunks mean larger LZ77
+dictionaries and better compression ratios on sufficiently large files, but
+slower random access.
 .TP
 \fB--threads\fR=\fINUM_THREADS\fR
 Number of threads to use for compressing data.  Default: autodetect (number of