INTRODUCTION
-This is wimlib version 1.7.4-BETA (December 2014). wimlib is a C library for
+This is wimlib version 1.8.0-BETA (February 2015). wimlib is a C library for
creating, modifying, extracting, and mounting files in the Windows Imaging
Format (WIM files). wimlib and its command-line frontend 'wimlib-imagex'
provide a free and cross-platform alternative to Microsoft's WIMGAPI, ImageX,
wimlib includes its own compression codecs and does not use the compression API
available on some versions of Windows.
-I have gradually been improving the compression codecs in wimlib. For XPRESS
-and LZX, they now usually outperform and outcompress the equivalent Microsoft
+I have gradually been improving the compression codecs in wimlib. For all three
+codecs, they now usually outperform and outcompress the equivalent Microsoft
implementations. Although results will vary depending on the data being
compressed, in the table below I present the results for a common use case:
compressing an x86 Windows PE image. Each row displays the compression type,
implementation in WIMGAPI is included.
=============================================================================
- | Compression || wimlib (v1.7.4) | WIMGAPI (Windows 8.1) |
+ | Compression || wimlib (v1.8.0) | WIMGAPI (Windows 8.1) |
=============================================================================
| None [1] || 361,314,224 in 2.4s | 361,315,338 in 4.5s |
| XPRESS [2] || 138,218,750 in 3.0s | 140,457,436 in 6.0s |
| XPRESS (slow) [3] || 135,173,511 in 8.9s | N/A |
- | LZX (quick) [4] || 130,332,007 in 4.1s | N/A |
- | LZX (normal) [5] || 126,714,807 in 12.5s | 127,293,240 in 19.2s |
- | LZX (slow) [6] || 126,150,743 in 20.5s | N/A |
- | LZMS (non-solid) [7] || 121,909,792 in 11.9s | N/A |
- | LZMS (solid) [8] || 93,650,936 in 45.0s | 88,771,192 in 109.2 |
+ | LZX (quick) [4] || 130,207,195 in 3.8s | N/A |
+ | LZX (normal) [5] || 126,522,539 in 10.4s | 127,293,240 in 19.2s |
+ | LZX (slow) [6] || 126,042,313 in 17.3s | N/A |
+ | LZMS (non-solid) [7] || 116,150,682 in 25.3s | N/A |
+ | LZMS (solid) [8] || 88,107,484 in 61.7s | 88,769,830 in 102.3s |
| "WIMBoot" [9] || 167,023,719 in 3.5s | 169,109,211 in 10.4s |
| "WIMBoot" (slow) [10] || 165,027,583 in 7.9s | N/A |
=============================================================================
[8] '--solid' for wimlib-imagex. Should be '/compress:recovery' for DISM,
but only works for /Export-Image, not /Capture-Image. Compression chunk
- size in solid blocks defaults to 33554432 for wimlib, 67108864 for DISM.
+ size in solid resources defaults to 67108864 bytes in both cases.
[9] '--wimboot' for wimlib-imagex; '/wimboot' for DISM.
This is really XPRESS compression with 4096 byte chunks, so the same as
The compression ratio provided by wimlib is also competitive with commonly used
archive formats. Below are file sizes that result when the Canterbury corpus is
-compressed with wimlib (v1.7.2), WIMGAPI (Windows 8.1), and some other
+compressed with wimlib (v1.8.0), WIMGAPI (Windows 8.1), and some other
formats/programs:
=====================================================
| WIM (WIMGAPI, None) | 2,814,254 |
| WIM (wimlib, None) | 2,814,216 |
| WIM (WIMGAPI, XPRESS) | 825,536 |
- | WIM (wimlib, XPRESS) | 790,016 |
+ | WIM (wimlib, XPRESS) | 789,296 |
| tar.gz (gzip, default) | 738,796 |
| ZIP (Info-ZIP, default) | 735,334 |
| tar.gz (gzip, -9) | 733,971 |
| ZIP (Info-ZIP, -9) | 732,297 |
- | WIM (wimlib, LZX quick) | 704,006 |
+ | WIM (wimlib, LZX quick) | 690,110 |
| WIM (WIMGAPI, LZX) | 651,866 |
- | WIM (wimlib, LZX normal) | 632,614 |
- | WIM (wimlib, LZX slow) | 625,050 |
- | WIM (wimlib, LZMS non-solid) | 581,960 |
+ | WIM (wimlib, LZX normal) | 624,634 |
+ | WIM (wimlib, LZX slow) | 620,728 |
+ | WIM (wimlib, LZMS non-solid) | 581,046 |
| tar.bz2 (bzip, default) | 565,008 |
| tar.bz2 (bzip, -9) | 565,008 |
- | WIM (wimlib, LZX solid) | 532,700 |
- | WIM (wimlib, LZMS solid) | 525,990 |
- | WIM (wimlib, LZX solid, slow) | 525,140 |
- | WIM (wimlib, LZMS solid, slow) | 523,728 |
| WIM (WIMGAPI, LZMS solid) | 521,366 |
- | WIM (wimlib, LZX solid, very slow) | 520,832 |
+ | WIM (wimlib, LZMS solid) | 515,800 |
| tar.xz (xz, default) | 486,916 |
| tar.xz (xz, -9) | 486,904 |
| 7z (7-zip, default) | 484,700 |
The WIM file format is partially specified in a document that can be found in
the Microsoft Download Center. However, this document really only provides an
overview of the format and is not a formal specification. It also does not
-cover later extensions of the format, such as solid blocks.
+cover later extensions of the format, such as solid resources.
With regards to the supported compression formats:
git://wimlib.net / wimlib / blobdiff