LZMA is a data compression algorithm, used in the 7z format of the 7-Zip archiver.
Support for multi-threading and for the Pentium 4 microprocessor's hyper-threading feature The decompression code for LZMA is around 5KB and the dynamic memory needed during decompression is modest (it depends on the dictionary size).
Unfortunately, the use of Microsoft Windows specific features is deeply buried in the source code, which makes it very difficult to create a Unix compatible version.
LZMA is a compression algorithm, based on the famous LempelZiv compression method.
The main characteristics of the algorithm are very good compression, fast decompression, use of lot of RAM for compression and low usage of RAM for decompression.
LZMA provides high compression ratio and very fast decompression, so it is very suitable for embedded applications.
There are some claims that LZMA can offer up to 30% better compression over ZLIB, however a 10 to 15% gain is normally achievable on the typical squashFS images found in modems such as the NB5.
One of LZMAs disadvantages is it requires more memory and CPU to compress the data, however only uses 1/10 of the memory to decompress.
SquashFS using LZMA currently requires patches, and unfortunately there is a couple of versions floating around were the format of the headers/properties are different and hence cause incompatibility problems.
The downside of lzma (of which we have added to) is that there seems to be no real standard on how the files are made which makes the different utils incompatible with eachother.
The feature common for all these packages are that they use the zlib/stream based method as used by the lzma patched mksquashfs found at http://oleg.wl500g.info/ Thanks to Ming-Ching Tiew for lzmatools and the kernel patch.
Buildroot stuff: lzmatools-buildroot.tgz is make files for lzmatools lzma-buildroot.tgz is a separate lzma tool from http://martinus.geekisp.com/rublog.cgi/Projects/LZMA This is not compatible with the other lzma based tools and patches here and neither the lzma tools you can compile from the SDK (the last time I checked at least) Thomas.
It needs to allocate some scratch space (between 5228 and 6295148 bytes, default value is 15980 bytes) besides src and dst.
lzma decompression can be called the same way as nrv2b decompression: static unsigned long unlzma(unsigned char * src, unsigned char * dst); Patch is attached.
Average compression ratio of LZMA is about 30% better than that of gzip, and 15% better than that of bzip2.
Decompression speed is only little slower than that of gzip, being two to five times faster than bzip2.
The patch for GNU tar integrates LZMA compression with the tar command in the same way as with gzip and bzip2.
tukaani.org /lzma (223 words)
OpenBSD Package Details - lzma-4.32.0beta2.tgz(Site not responding. Last check: )
With bzip2LZMA is in par when compressing with approximately same compression ratio but for smallest file size the time required can be 5 times the time used by bzip2.
Luckily the same does not apply to decompression speed: even the tightest LZMA files can be decompressed in time less than a half of the time that bzip2 would take.
This makes LZMA an ideal compression tool for distributing files in the Internet and on CDs/DVDs because the files are usually compressed only once but decompressed many times.
This tool uses raw LZMA format as opposed to 7z container format, which uses LZMA as the default compression algorithm, but has many additional features and a header incompatible to that of raw LZMA streams.
Simple command line version of compression program using LZMA compression method.
LZMA can compress and decompress data streams using standard input/output.
Supports creation of a single EXE to install your program for easy online distribution.
Includes integrated support for "deflate", bzip2, and 7-ZipLZMA file compression.
The installer has the ability to compare file version info, replace in-use files, use shared file counting, register DLL/OCX's and type libraries, and install fonts.
