Update wimlib-imagex documentation

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

diff --git a/doc/imagex-capture.1.in b/doc/imagex-capture.1.in
index 6a0ed43d2c644e9817a35653822251ba9d52673c..8b70c9ba3e301ea585ff0a2369bf0d56c41ab9d4 100644 (file)
--- a/doc/imagex-capture.1.in
+++ b/doc/imagex-capture.1.in
@@ -189,6 +189,14 @@ request a better compression ratio at the cost of more time spent compressing.
 .IP ""
 You may also specify the actual names of the compression algorithms, "XPRESS"
 and "LZX", instead of "fast" and "maximum", respectively.
+.IP ""
+As of wimlib v1.6.0, a third compression type, "recovery" or "LZMS", is also
+available.  Its use is not recommended because other than wimlib itself, as of
+Windows 8 it is only compatible with WIMGAPI and Windows Setup (not even ImageX
+or Dism).  Furthermore, wimlib's LZMS compressor is currently less well
+optimized than its LZX compressor.  However, LZMS is the compression algorithm
+used in packed resources created if the \fB--pack-streams\fR option is
+specified.
 .TP
 \fB--compress-slow\fR
 Like \fB--compress\fR=\fImaximum\fR, but spend even more time compressing the
@@ -196,13 +204,31 @@ data to achieve a very slightly better compression ratio.
 .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.
+recommended because WIM chunk sizes other than the default of 32768 have varying
+levels of compatibility with Microsoft's software (depending on the compression
+type, chunk size, and software version).  In addition, wimlib versions before
+1.6.0 do not support alternate chunk sizes.  But if you decide to use this
+option regardless, you can choose a chunk size that is a power of 2 greater than
+or equal to 2^15 (32768) up to a maximum determined by the compression format.
+Larger chunks mean larger LZ77 dictionaries and better compression ratios on
+sufficiently large files, but slower random access.  For LZX ("maximum")
+compression, the maximum allowed chunk size is 2^21 (2097152), and for XPRESS
+("fast") and LZMS ("recovery") compression, the maximum allowed chunk size is
+2^26 (67108644).
+.TP
+\fB--pack-streams\fR
+Create a "solid" archive that compresses multiple unique streams ("files")
+together, rather than each unique stream ("file") independently.  This can
+result in a significantly better compression ratio, but this format greatly
+decreases the performance of random access to the data, as may occur on a WIM
+mounted with \fB@IMAGEX_PROGNAME@ mount\fR.  Also, WIMs created using this
+option use a different version number in their header and as of Windows 8 are
+only compatible with Windows Setup and WIMGAPI, not even ImageX and Dism.
+.IP ""
+Packed resources use a chunk size that is independent of the WIM's "default
+chunk size", the latter of which may be adjusted by the \fB--chunk-size\fR
+option.  For compatibility reasons, there is currently no option to change the
+compression algorithm or chunk size used in packed resources.
 .TP
 \fB--threads\fR=\fINUM_THREADS\fR
 Number of threads to use for compressing data.  Default: autodetect (number of