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author | Peter Tyser <ptyser@xes-inc.com> | 2010-04-12 22:28:05 -0500 |
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committer | Wolfgang Denk <wd@denx.de> | 2010-04-13 09:13:04 +0200 |
commit | 78acc472d9719316f22e002a009a998d9ceec29d (patch) | |
tree | aa99461b3d693cf3691869abea485091860a66d0 /lib_generic/lzma/lzma.txt | |
parent | ea0364f1bbfed1e3ea711147420875cf338fe77a (diff) | |
download | u-boot-imx-78acc472d9719316f22e002a009a998d9ceec29d.zip u-boot-imx-78acc472d9719316f22e002a009a998d9ceec29d.tar.gz u-boot-imx-78acc472d9719316f22e002a009a998d9ceec29d.tar.bz2 |
Rename lib_generic/ to lib/
Now that the other architecture-specific lib directories have been
moved out of the top-level directory there's not much reason to have the
'_generic' suffix on the common lib directory.
Signed-off-by: Peter Tyser <ptyser@xes-inc.com>
Diffstat (limited to 'lib_generic/lzma/lzma.txt')
-rw-r--r-- | lib_generic/lzma/lzma.txt | 594 |
1 files changed, 0 insertions, 594 deletions
diff --git a/lib_generic/lzma/lzma.txt b/lib_generic/lzma/lzma.txt deleted file mode 100644 index aa20f9d..0000000 --- a/lib_generic/lzma/lzma.txt +++ /dev/null @@ -1,594 +0,0 @@ -LZMA SDK 4.65 -------------- - -LZMA SDK provides the documentation, samples, header files, libraries, -and tools you need to develop applications that use LZMA compression. - -LZMA is default and general compression method of 7z format -in 7-Zip compression program (www.7-zip.org). LZMA provides high -compression ratio and very fast decompression. - -LZMA is an improved version of famous LZ77 compression algorithm. -It was improved in way of maximum increasing of compression ratio, -keeping high decompression speed and low memory requirements for -decompressing. - - - -LICENSE -------- - -LZMA SDK is written and placed in the public domain by Igor Pavlov. - - -LZMA SDK Contents ------------------ - -LZMA SDK includes: - - - ANSI-C/C++/C#/Java source code for LZMA compressing and decompressing - - Compiled file->file LZMA compressing/decompressing program for Windows system - - -UNIX/Linux version ------------------- -To compile C++ version of file->file LZMA encoding, go to directory -C++/7zip/Compress/LZMA_Alone -and call make to recompile it: - make -f makefile.gcc clean all - -In some UNIX/Linux versions you must compile LZMA with static libraries. -To compile with static libraries, you can use -LIB = -lm -static - - -Files ---------------------- -lzma.txt - LZMA SDK description (this file) -7zFormat.txt - 7z Format description -7zC.txt - 7z ANSI-C Decoder description -methods.txt - Compression method IDs for .7z -lzma.exe - Compiled file->file LZMA encoder/decoder for Windows -history.txt - history of the LZMA SDK - - -Source code structure ---------------------- - -C/ - C files - 7zCrc*.* - CRC code - Alloc.* - Memory allocation functions - Bra*.* - Filters for x86, IA-64, ARM, ARM-Thumb, PowerPC and SPARC code - LzFind.* - Match finder for LZ (LZMA) encoders - LzFindMt.* - Match finder for LZ (LZMA) encoders for multithreading encoding - LzHash.h - Additional file for LZ match finder - LzmaDec.* - LZMA decoding - LzmaEnc.* - LZMA encoding - LzmaLib.* - LZMA Library for DLL calling - Types.h - Basic types for another .c files - Threads.* - The code for multithreading. - - LzmaLib - LZMA Library (.DLL for Windows) - - LzmaUtil - LZMA Utility (file->file LZMA encoder/decoder). - - Archive - files related to archiving - 7z - 7z ANSI-C Decoder - -CPP/ -- CPP files - - Common - common files for C++ projects - Windows - common files for Windows related code - - 7zip - files related to 7-Zip Project - - Common - common files for 7-Zip - - Compress - files related to compression/decompression - - Copy - Copy coder - RangeCoder - Range Coder (special code of compression/decompression) - LZMA - LZMA compression/decompression on C++ - LZMA_Alone - file->file LZMA compression/decompression - Branch - Filters for x86, IA-64, ARM, ARM-Thumb, PowerPC and SPARC code - - Archive - files related to archiving - - Common - common files for archive handling - 7z - 7z C++ Encoder/Decoder - - Bundles - Modules that are bundles of other modules - - Alone7z - 7zr.exe: Standalone version of 7z.exe that supports only 7z/LZMA/BCJ/BCJ2 - Format7zR - 7zr.dll: Reduced version of 7za.dll: extracting/compressing to 7z/LZMA/BCJ/BCJ2 - Format7zExtractR - 7zxr.dll: Reduced version of 7zxa.dll: extracting from 7z/LZMA/BCJ/BCJ2. - - UI - User Interface files - - Client7z - Test application for 7za.dll, 7zr.dll, 7zxr.dll - Common - Common UI files - Console - Code for console archiver - - - -CS/ - C# files - 7zip - Common - some common files for 7-Zip - Compress - files related to compression/decompression - LZ - files related to LZ (Lempel-Ziv) compression algorithm - LZMA - LZMA compression/decompression - LzmaAlone - file->file LZMA compression/decompression - RangeCoder - Range Coder (special code of compression/decompression) - -Java/ - Java files - SevenZip - Compression - files related to compression/decompression - LZ - files related to LZ (Lempel-Ziv) compression algorithm - LZMA - LZMA compression/decompression - RangeCoder - Range Coder (special code of compression/decompression) - - -C/C++ source code of LZMA SDK is part of 7-Zip project. -7-Zip source code can be downloaded from 7-Zip's SourceForge page: - - http://sourceforge.net/projects/sevenzip/ - - - -LZMA features -------------- - - Variable dictionary size (up to 1 GB) - - Estimated compressing speed: about 2 MB/s on 2 GHz CPU - - Estimated decompressing speed: - - 20-30 MB/s on 2 GHz Core 2 or AMD Athlon 64 - - 1-2 MB/s on 200 MHz ARM, MIPS, PowerPC or other simple RISC - - Small memory requirements for decompressing (16 KB + DictionarySize) - - Small code size for decompressing: 5-8 KB - -LZMA decoder uses only integer operations and can be -implemented in any modern 32-bit CPU (or on 16-bit CPU with some conditions). - -Some critical operations that affect the speed of LZMA decompression: - 1) 32*16 bit integer multiply - 2) Misspredicted branches (penalty mostly depends from pipeline length) - 3) 32-bit shift and arithmetic operations - -The speed of LZMA decompressing mostly depends from CPU speed. -Memory speed has no big meaning. But if your CPU has small data cache, -overall weight of memory speed will slightly increase. - - -How To Use ----------- - -Using LZMA encoder/decoder executable --------------------------------------- - -Usage: LZMA <e|d> inputFile outputFile [<switches>...] - - e: encode file - - d: decode file - - b: Benchmark. There are two tests: compressing and decompressing - with LZMA method. Benchmark shows rating in MIPS (million - instructions per second). Rating value is calculated from - measured speed and it is normalized with Intel's Core 2 results. - Also Benchmark checks possible hardware errors (RAM - errors in most cases). Benchmark uses these settings: - (-a1, -d21, -fb32, -mfbt4). You can change only -d parameter. - Also you can change the number of iterations. Example for 30 iterations: - LZMA b 30 - Default number of iterations is 10. - -<Switches> - - - -a{N}: set compression mode 0 = fast, 1 = normal - default: 1 (normal) - - d{N}: Sets Dictionary size - [0, 30], default: 23 (8MB) - The maximum value for dictionary size is 1 GB = 2^30 bytes. - Dictionary size is calculated as DictionarySize = 2^N bytes. - For decompressing file compressed by LZMA method with dictionary - size D = 2^N you need about D bytes of memory (RAM). - - -fb{N}: set number of fast bytes - [5, 273], default: 128 - Usually big number gives a little bit better compression ratio - and slower compression process. - - -lc{N}: set number of literal context bits - [0, 8], default: 3 - Sometimes lc=4 gives gain for big files. - - -lp{N}: set number of literal pos bits - [0, 4], default: 0 - lp switch is intended for periodical data when period is - equal 2^N. For example, for 32-bit (4 bytes) - periodical data you can use lp=2. Often it's better to set lc0, - if you change lp switch. - - -pb{N}: set number of pos bits - [0, 4], default: 2 - pb switch is intended for periodical data - when period is equal 2^N. - - -mf{MF_ID}: set Match Finder. Default: bt4. - Algorithms from hc* group doesn't provide good compression - ratio, but they often works pretty fast in combination with - fast mode (-a0). - - Memory requirements depend from dictionary size - (parameter "d" in table below). - - MF_ID Memory Description - - bt2 d * 9.5 + 4MB Binary Tree with 2 bytes hashing. - bt3 d * 11.5 + 4MB Binary Tree with 3 bytes hashing. - bt4 d * 11.5 + 4MB Binary Tree with 4 bytes hashing. - hc4 d * 7.5 + 4MB Hash Chain with 4 bytes hashing. - - -eos: write End Of Stream marker. By default LZMA doesn't write - eos marker, since LZMA decoder knows uncompressed size - stored in .lzma file header. - - -si: Read data from stdin (it will write End Of Stream marker). - -so: Write data to stdout - - -Examples: - -1) LZMA e file.bin file.lzma -d16 -lc0 - -compresses file.bin to file.lzma with 64 KB dictionary (2^16=64K) -and 0 literal context bits. -lc0 allows to reduce memory requirements -for decompression. - - -2) LZMA e file.bin file.lzma -lc0 -lp2 - -compresses file.bin to file.lzma with settings suitable -for 32-bit periodical data (for example, ARM or MIPS code). - -3) LZMA d file.lzma file.bin - -decompresses file.lzma to file.bin. - - -Compression ratio hints ------------------------ - -Recommendations ---------------- - -To increase the compression ratio for LZMA compressing it's desirable -to have aligned data (if it's possible) and also it's desirable to locate -data in such order, where code is grouped in one place and data is -grouped in other place (it's better than such mixing: code, data, code, -data, ...). - - -Filters -------- -You can increase the compression ratio for some data types, using -special filters before compressing. For example, it's possible to -increase the compression ratio on 5-10% for code for those CPU ISAs: -x86, IA-64, ARM, ARM-Thumb, PowerPC, SPARC. - -You can find C source code of such filters in C/Bra*.* files - -You can check the compression ratio gain of these filters with such -7-Zip commands (example for ARM code): -No filter: - 7z a a1.7z a.bin -m0=lzma - -With filter for little-endian ARM code: - 7z a a2.7z a.bin -m0=arm -m1=lzma - -It works in such manner: -Compressing = Filter_encoding + LZMA_encoding -Decompressing = LZMA_decoding + Filter_decoding - -Compressing and decompressing speed of such filters is very high, -so it will not increase decompressing time too much. -Moreover, it reduces decompression time for LZMA_decoding, -since compression ratio with filtering is higher. - -These filters convert CALL (calling procedure) instructions -from relative offsets to absolute addresses, so such data becomes more -compressible. - -For some ISAs (for example, for MIPS) it's impossible to get gain from such filter. - - -LZMA compressed file format ---------------------------- -Offset Size Description - 0 1 Special LZMA properties (lc,lp, pb in encoded form) - 1 4 Dictionary size (little endian) - 5 8 Uncompressed size (little endian). -1 means unknown size - 13 Compressed data - - -ANSI-C LZMA Decoder -~~~~~~~~~~~~~~~~~~~ - -Please note that interfaces for ANSI-C code were changed in LZMA SDK 4.58. -If you want to use old interfaces you can download previous version of LZMA SDK -from sourceforge.net site. - -To use ANSI-C LZMA Decoder you need the following files: -1) LzmaDec.h + LzmaDec.c + Types.h -LzmaUtil/LzmaUtil.c is example application that uses these files. - - -Memory requirements for LZMA decoding -------------------------------------- - -Stack usage of LZMA decoding function for local variables is not -larger than 200-400 bytes. - -LZMA Decoder uses dictionary buffer and internal state structure. -Internal state structure consumes - state_size = (4 + (1.5 << (lc + lp))) KB -by default (lc=3, lp=0), state_size = 16 KB. - - -How To decompress data ----------------------- - -LZMA Decoder (ANSI-C version) now supports 2 interfaces: -1) Single-call Decompressing -2) Multi-call State Decompressing (zlib-like interface) - -You must use external allocator: -Example: -void *SzAlloc(void *p, size_t size) { p = p; return malloc(size); } -void SzFree(void *p, void *address) { p = p; free(address); } -ISzAlloc alloc = { SzAlloc, SzFree }; - -You can use p = p; operator to disable compiler warnings. - - -Single-call Decompressing -------------------------- -When to use: RAM->RAM decompressing -Compile files: LzmaDec.h + LzmaDec.c + Types.h -Compile defines: no defines -Memory Requirements: - - Input buffer: compressed size - - Output buffer: uncompressed size - - LZMA Internal Structures: state_size (16 KB for default settings) - -Interface: - int LzmaDecode(Byte *dest, SizeT *destLen, const Byte *src, SizeT *srcLen, - const Byte *propData, unsigned propSize, ELzmaFinishMode finishMode, - ELzmaStatus *status, ISzAlloc *alloc); - In: - dest - output data - destLen - output data size - src - input data - srcLen - input data size - propData - LZMA properties (5 bytes) - propSize - size of propData buffer (5 bytes) - finishMode - It has meaning only if the decoding reaches output limit (*destLen). - LZMA_FINISH_ANY - Decode just destLen bytes. - LZMA_FINISH_END - Stream must be finished after (*destLen). - You can use LZMA_FINISH_END, when you know that - current output buffer covers last bytes of stream. - alloc - Memory allocator. - - Out: - destLen - processed output size - srcLen - processed input size - - Output: - SZ_OK - status: - LZMA_STATUS_FINISHED_WITH_MARK - LZMA_STATUS_NOT_FINISHED - LZMA_STATUS_MAYBE_FINISHED_WITHOUT_MARK - SZ_ERROR_DATA - Data error - SZ_ERROR_MEM - Memory allocation error - SZ_ERROR_UNSUPPORTED - Unsupported properties - SZ_ERROR_INPUT_EOF - It needs more bytes in input buffer (src). - - If LZMA decoder sees end_marker before reaching output limit, it returns OK result, - and output value of destLen will be less than output buffer size limit. - - You can use multiple checks to test data integrity after full decompression: - 1) Check Result and "status" variable. - 2) Check that output(destLen) = uncompressedSize, if you know real uncompressedSize. - 3) Check that output(srcLen) = compressedSize, if you know real compressedSize. - You must use correct finish mode in that case. */ - - -Multi-call State Decompressing (zlib-like interface) ----------------------------------------------------- - -When to use: file->file decompressing -Compile files: LzmaDec.h + LzmaDec.c + Types.h - -Memory Requirements: - - Buffer for input stream: any size (for example, 16 KB) - - Buffer for output stream: any size (for example, 16 KB) - - LZMA Internal Structures: state_size (16 KB for default settings) - - LZMA dictionary (dictionary size is encoded in LZMA properties header) - -1) read LZMA properties (5 bytes) and uncompressed size (8 bytes, little-endian) to header: - unsigned char header[LZMA_PROPS_SIZE + 8]; - ReadFile(inFile, header, sizeof(header) - -2) Allocate CLzmaDec structures (state + dictionary) using LZMA properties - - CLzmaDec state; - LzmaDec_Constr(&state); - res = LzmaDec_Allocate(&state, header, LZMA_PROPS_SIZE, &g_Alloc); - if (res != SZ_OK) - return res; - -3) Init LzmaDec structure before any new LZMA stream. And call LzmaDec_DecodeToBuf in loop - - LzmaDec_Init(&state); - for (;;) - { - ... - int res = LzmaDec_DecodeToBuf(CLzmaDec *p, Byte *dest, SizeT *destLen, - const Byte *src, SizeT *srcLen, ELzmaFinishMode finishMode); - ... - } - - -4) Free all allocated structures - LzmaDec_Free(&state, &g_Alloc); - -For full code example, look at C/LzmaUtil/LzmaUtil.c code. - - -How To compress data --------------------- - -Compile files: LzmaEnc.h + LzmaEnc.c + Types.h + -LzFind.c + LzFind.h + LzFindMt.c + LzFindMt.h + LzHash.h - -Memory Requirements: - - (dictSize * 11.5 + 6 MB) + state_size - -Lzma Encoder can use two memory allocators: -1) alloc - for small arrays. -2) allocBig - for big arrays. - -For example, you can use Large RAM Pages (2 MB) in allocBig allocator for -better compression speed. Note that Windows has bad implementation for -Large RAM Pages. -It's OK to use same allocator for alloc and allocBig. - - -Single-call Compression with callbacks --------------------------------------- - -Check C/LzmaUtil/LzmaUtil.c as example, - -When to use: file->file decompressing - -1) you must implement callback structures for interfaces: -ISeqInStream -ISeqOutStream -ICompressProgress -ISzAlloc - -static void *SzAlloc(void *p, size_t size) { p = p; return MyAlloc(size); } -static void SzFree(void *p, void *address) { p = p; MyFree(address); } -static ISzAlloc g_Alloc = { SzAlloc, SzFree }; - - CFileSeqInStream inStream; - CFileSeqOutStream outStream; - - inStream.funcTable.Read = MyRead; - inStream.file = inFile; - outStream.funcTable.Write = MyWrite; - outStream.file = outFile; - - -2) Create CLzmaEncHandle object; - - CLzmaEncHandle enc; - - enc = LzmaEnc_Create(&g_Alloc); - if (enc == 0) - return SZ_ERROR_MEM; - - -3) initialize CLzmaEncProps properties; - - LzmaEncProps_Init(&props); - - Then you can change some properties in that structure. - -4) Send LZMA properties to LZMA Encoder - - res = LzmaEnc_SetProps(enc, &props); - -5) Write encoded properties to header - - Byte header[LZMA_PROPS_SIZE + 8]; - size_t headerSize = LZMA_PROPS_SIZE; - UInt64 fileSize; - int i; - - res = LzmaEnc_WriteProperties(enc, header, &headerSize); - fileSize = MyGetFileLength(inFile); - for (i = 0; i < 8; i++) - header[headerSize++] = (Byte)(fileSize >> (8 * i)); - MyWriteFileAndCheck(outFile, header, headerSize) - -6) Call encoding function: - res = LzmaEnc_Encode(enc, &outStream.funcTable, &inStream.funcTable, - NULL, &g_Alloc, &g_Alloc); - -7) Destroy LZMA Encoder Object - LzmaEnc_Destroy(enc, &g_Alloc, &g_Alloc); - - -If callback function return some error code, LzmaEnc_Encode also returns that code. - - -Single-call RAM->RAM Compression --------------------------------- - -Single-call RAM->RAM Compression is similar to Compression with callbacks, -but you provide pointers to buffers instead of pointers to stream callbacks: - -HRes LzmaEncode(Byte *dest, SizeT *destLen, const Byte *src, SizeT srcLen, - CLzmaEncProps *props, Byte *propsEncoded, SizeT *propsSize, int writeEndMark, - ICompressProgress *progress, ISzAlloc *alloc, ISzAlloc *allocBig); - -Return code: - SZ_OK - OK - SZ_ERROR_MEM - Memory allocation error - SZ_ERROR_PARAM - Incorrect paramater - SZ_ERROR_OUTPUT_EOF - output buffer overflow - SZ_ERROR_THREAD - errors in multithreading functions (only for Mt version) - - - -LZMA Defines ------------- - -_LZMA_SIZE_OPT - Enable some optimizations in LZMA Decoder to get smaller executable code. - -_LZMA_PROB32 - It can increase the speed on some 32-bit CPUs, but memory usage for - some structures will be doubled in that case. - -_LZMA_UINT32_IS_ULONG - Define it if int is 16-bit on your compiler and long is 32-bit. - -_LZMA_NO_SYSTEM_SIZE_T - Define it if you don't want to use size_t type. - - -C++ LZMA Encoder/Decoder -~~~~~~~~~~~~~~~~~~~~~~~~ -C++ LZMA code use COM-like interfaces. So if you want to use it, -you can study basics of COM/OLE. -C++ LZMA code is just wrapper over ANSI-C code. - - -C++ Notes -~~~~~~~~~~~~~~~~~~~~~~~~ -If you use some C++ code folders in 7-Zip (for example, C++ code for .7z handling), -you must check that you correctly work with "new" operator. -7-Zip can be compiled with MSVC 6.0 that doesn't throw "exception" from "new" operator. -So 7-Zip uses "CPP\Common\NewHandler.cpp" that redefines "new" operator: -operator new(size_t size) -{ - void *p = ::malloc(size); - if (p == 0) - throw CNewException(); - return p; -} -If you use MSCV that throws exception for "new" operator, you can compile without -"NewHandler.cpp". So standard exception will be used. Actually some code of -7-Zip catches any exception in internal code and converts it to HRESULT code. -So you don't need to catch CNewException, if you call COM interfaces of 7-Zip. - ---- - -http://www.7-zip.org -http://www.7-zip.org/sdk.html -http://www.7-zip.org/support.html |