lib/lzma/lzma.txt

2 -------------
8 in 7-Zip compression program (www.7-zip.org). LZMA provides high
19 -------
23 Some code in LZMA SDK is based on public domain code from another developers:
25   2) SHA-256: Wei Dai (Crypto++ library)
29 -----------------
33   - ANSI-C/C++/C#/Java source code for LZMA compressing and decompressing
34   - Compiled file->file LZMA compressing/decompressing program for Windows system
38 ------------------
39 To compile C++ version of file->file LZMA encoding, go to directory
42   make -f makefile.gcc clean all
46 LIB = -lm -static
50 ---------------------
51 lzma.txt     - LZMA SDK description (this file)
52 7zFormat.txt - 7z Format description
53 7zC.txt      - 7z ANSI-C Decoder description
54 methods.txt  - Compression method IDs for .7z
55 lzma.exe     - Compiled file->file LZMA encoder/decoder for Windows
56 7zr.exe      - 7-Zip with 7z/lzma/xz support.
57 history.txt  - history of the LZMA SDK
60 Source code structure
61 ---------------------
63 C/  - C files
64         7zCrc*.*   - CRC code
65         Alloc.*    - Memory allocation functions
66         Bra*.*     - Filters for x86, IA-64, ARM, ARM-Thumb, PowerPC and SPARC code
67         LzFind.*   - Match finder for LZ (LZMA) encoders
68         LzFindMt.* - Match finder for LZ (LZMA) encoders for multithreading encoding
69         LzHash.h   - Additional file for LZ match finder
70         LzmaDec.*  - LZMA decoding
71         LzmaEnc.*  - LZMA encoding
72         LzmaLib.*  - LZMA Library for DLL calling
73         Types.h    - Basic types for another .c files
74         Threads.*  - The code for multithreading.
76     LzmaLib  - LZMA Library (.DLL for Windows)
78     LzmaUtil - LZMA Utility (file->file LZMA encoder/decoder).
80     Archive - files related to archiving
81       7z     - 7z ANSI-C Decoder
83 CPP/ -- CPP files
85   Common  - common files for C++ projects
86   Windows - common files for Windows related code
88   7zip    - files related to 7-Zip Project
90     Common   - common files for 7-Zip
92     Compress - files related to compression/decompression
94     Archive - files related to archiving
96       Common   - common files for archive handling
97       7z       - 7z C++ Encoder/Decoder
99     Bundles    - Modules that are bundles of other modules
101       Alone7z           - 7zr.exe: Standalone version of 7z.exe that supports only 7z/LZMA/BCJ/BCJ2
102       LzmaCon           - lzma.exe: LZMA compression/decompression
103 …Format7zR         - 7zr.dll: Reduced version of 7za.dll: extracting/compressing to 7z/LZMA/BCJ/BCJ2
104       Format7zExtractR  - 7zxr.dll: Reduced version of 7zxa.dll: extracting from 7z/LZMA/BCJ/BCJ2.
106     UI        - User Interface files
108       Client7z - Test application for 7za.dll,  7zr.dll, 7zxr.dll
109       Common   - Common UI files
110       Console  - Code for console archiver
114 CS/ - C# files
116     Common   - some common files for 7-Zip
117     Compress - files related to compression/decompression
118       LZ     - files related to LZ (Lempel-Ziv) compression algorithm
119       LZMA         - LZMA compression/decompression
120       LzmaAlone    - file->file LZMA compression/decompression
121       RangeCoder   - Range Coder (special code of compression/decompression)
123 Java/  - Java files
125     Compression    - files related to compression/decompression
126       LZ           - files related to LZ (Lempel-Ziv) compression algorithm
127       LZMA         - LZMA compression/decompression
128       RangeCoder   - Range Coder (special code of compression/decompression)
131 C/C++ source code of LZMA SDK is part of 7-Zip project.
132 7-Zip source code can be downloaded from 7-Zip's SourceForge page:
139 -------------
140   - Variable dictionary size (up to 1 GB)
141   - Estimated compressing speed: about 2 MB/s on 2 GHz CPU
142   - Estimated decompressing speed:
143       - 20-30 MB/s on 2 GHz Core 2 or AMD Athlon 64
144       - 1-2 MB/s on 200 MHz ARM, MIPS, PowerPC or other simple RISC
145   - Small memory requirements for decompressing (16 KB + DictionarySize)
146   - Small code size for decompressing: 5-8 KB
149 implemented in any modern 32-bit CPU (or on 16-bit CPU with some conditions).
154   3) 32-bit shift and arithmetic operations
162 ----------
165 --------------------------------------
177      Also Benchmark checks possible hardware errors (RAM
179      (-a1, -d21, -fb32, -mfbt4). You can change only -d parameter.
187   -a{N}:  set compression mode 0 = fast, 1 = normal
190   d{N}:   Sets Dictionary size - [0, 30], default: 23 (8MB)
194           size D = 2^N you need about D bytes of memory (RAM).
196   -fb{N}: set number of fast bytes - [5, 273], default: 128
200   -lc{N}: set number of literal context bits - [0, 8], default: 3
203   -lp{N}: set number of literal pos bits - [0, 4], default: 0
205           equal 2^N. For example, for 32-bit (4 bytes)
209   -pb{N}: set number of pos bits - [0, 4], default: 2
213   -mf{MF_ID}: set Match Finder. Default: bt4.
216               fast mode (-a0).
228   -eos:   write End Of Stream marker. By default LZMA doesn't write
232   -si:    Read data from stdin (it will write End Of Stream marker).
233   -so:    Write data to stdout
238 1) LZMA e file.bin file.lzma -d16 -lc0
241 and 0 literal context bits. -lc0 allows to reduce memory requirements
245 2) LZMA e file.bin file.lzma -lc0 -lp2
248 for 32-bit periodical data (for example, ARM or MIPS code).
256 -----------------------
259 ---------------
263 data in such order, where code is grouped in one place and data is
264 grouped in other place (it's better than such mixing: code, data, code,
269 -------
272 increase the compression ratio on 5-10% for code for those CPU ISAs:
273 x86, IA-64, ARM, ARM-Thumb, PowerPC, SPARC.
275 You can find C source code of such filters in C/Bra*.* files
278 7-Zip commands (example for ARM code):
280   7z a a1.7z a.bin -m0=lzma
282 With filter for little-endian ARM code:
283   7z a a2.7z a.bin -m0=arm -m1=lzma
302 ---------------------------
306   5     8   Uncompressed size (little endian). -1 means unknown size
310 ANSI-C LZMA Decoder
313 Please note that interfaces for ANSI-C code were changed in LZMA SDK 4.58.
317 To use ANSI-C LZMA Decoder you need the following files:
323 -------------------------------------
326 larger than 200-400 bytes.
335 ----------------------
337 LZMA Decoder (ANSI-C version) now supports 2 interfaces:
338 1) Single-call Decompressing
339 2) Multi-call State Decompressing (zlib-like interface)
350 Single-call Decompressing
351 -------------------------
352 When to use: RAM->RAM decompressing
356   - Input buffer: compressed size
357   - Output buffer: uncompressed size
358   - LZMA Internal Structures: state_size (16 KB for default settings)
365     dest     - output data
366     destLen  - output data size
367     src      - input data
368     srcLen   - input data size
369     propData - LZMA properties  (5 bytes)
370     propSize - size of propData buffer (5 bytes)
371     finishMode - It has meaning only if the decoding reaches output limit (*destLen).
372          LZMA_FINISH_ANY - Decode just destLen bytes.
373          LZMA_FINISH_END - Stream must be finished after (*destLen).
376     alloc    - Memory allocator.
379     destLen  - processed output size
380     srcLen   - processed input size
388     SZ_ERROR_DATA - Data error
389     SZ_ERROR_MEM  - Memory allocation error
390     SZ_ERROR_UNSUPPORTED - Unsupported properties
391     SZ_ERROR_INPUT_EOF - It needs more bytes in input buffer (src).
403 Multi-call State Decompressing (zlib-like interface)
404 ----------------------------------------------------
406 When to use: file->file decompressing
410  - Buffer for input stream: any size (for example, 16 KB)
411  - Buffer for output stream: any size (for example, 16 KB)
412  - LZMA Internal Structures: state_size (16 KB for default settings)
413  - LZMA dictionary (dictionary size is encoded in LZMA properties header)
415 1) read LZMA properties (5 bytes) and uncompressed size (8 bytes, little-endian) to header:
442 For full code example, look at C/LzmaUtil/LzmaUtil.c code.
446 --------------------
452   - (dictSize * 11.5 + 6 MB) + state_size
455 1) alloc - for small arrays.
456 2) allocBig - for big arrays.
458 For example, you can use Large RAM Pages (2 MB) in allocBig allocator for
460 Large RAM Pages.
464 Single-call Compression with callbacks
465 --------------------------------------
469 When to use: file->file decompressing
530 If callback function return some error code, LzmaEnc_Encode also returns that code
531 or it can return the code like SZ_ERROR_READ, SZ_ERROR_WRITE or SZ_ERROR_PROGRESS.
534 Single-call RAM->RAM Compression
535 --------------------------------
537 Single-call RAM->RAM Compression is similar to Compression with callbacks,
544 Return code:
545   SZ_OK               - OK
546   SZ_ERROR_MEM        - Memory allocation error
547   SZ_ERROR_PARAM      - Incorrect paramater
548   SZ_ERROR_OUTPUT_EOF - output buffer overflow
549   SZ_ERROR_THREAD     - errors in multithreading functions (only for Mt version)
554 -------
556 _LZMA_SIZE_OPT - Enable some optimizations in LZMA Decoder to get smaller executable code.
558 _LZMA_PROB32   - It can increase the speed on some 32-bit CPUs, but memory usage for
561 _LZMA_UINT32_IS_ULONG  - Define it if int is 16-bit on your compiler and long is 32-bit.
563 _LZMA_NO_SYSTEM_SIZE_T  - Define it if you don't want to use size_t type.
566 _7ZIP_PPMD_SUPPPORT - Define it if you don't want to support PPMD method in AMSI-C .7z decoder.
571 C++ LZMA code use COM-like interfaces. So if you want to use it,
573 C++ LZMA code is just wrapper over ANSI-C code.
578 If you use some C++ code folders in 7-Zip (for example, C++ code for .7z handling),
580 7-Zip can be compiled with MSVC 6.0 that doesn't throw "exception" from "new" operator.
581 So 7-Zip uses "CPP\Common\NewHandler.cpp" that redefines "new" operator:
590 "NewHandler.cpp". So standard exception will be used. Actually some code of
591 7-Zip catches any exception in internal code and converts it to HRESULT code.
592 So you don't need to catch CNewException, if you call COM interfaces of 7-Zip.
594 ---
596 http://www.7-zip.org
597 http://www.7-zip.org/sdk.html
598 http://www.7-zip.org/support.html