/* Lzma86.h -- LZMA + x86 (BCJ) Filter | |
2013-01-18 : Igor Pavlov : Public domain */ | |
#ifndef __LZMA86_H | |
#define __LZMA86_H | |
#include "7zTypes.h" | |
EXTERN_C_BEGIN | |
#define LZMA86_SIZE_OFFSET (1 + 5) | |
#define LZMA86_HEADER_SIZE (LZMA86_SIZE_OFFSET + 8) | |
/* | |
It's an example for LZMA + x86 Filter use. | |
You can use .lzma86 extension, if you write that stream to file. | |
.lzma86 header adds one additional byte to standard .lzma header. | |
.lzma86 header (14 bytes): | |
Offset Size Description | |
0 1 = 0 - no filter, pure LZMA | |
= 1 - x86 filter + LZMA | |
1 1 lc, lp and pb in encoded form | |
2 4 dictSize (little endian) | |
6 8 uncompressed size (little endian) | |
Lzma86_Encode | |
------------- | |
level - compression level: 0 <= level <= 9, the default value for "level" is 5. | |
dictSize - The dictionary size in bytes. The maximum value is | |
128 MB = (1 << 27) bytes for 32-bit version | |
1 GB = (1 << 30) bytes for 64-bit version | |
The default value is 16 MB = (1 << 24) bytes, for level = 5. | |
It's recommended to use the dictionary that is larger than 4 KB and | |
that can be calculated as (1 << N) or (3 << N) sizes. | |
For better compression ratio dictSize must be >= inSize. | |
filterMode: | |
SZ_FILTER_NO - no Filter | |
SZ_FILTER_YES - x86 Filter | |
SZ_FILTER_AUTO - it tries both alternatives to select best. | |
Encoder will use 2 or 3 passes: | |
2 passes when FILTER_NO provides better compression. | |
3 passes when FILTER_YES provides better compression. | |
Lzma86Encode allocates Data with MyAlloc functions. | |
RAM Requirements for compressing: | |
RamSize = dictionarySize * 11.5 + 6MB + FilterBlockSize | |
filterMode FilterBlockSize | |
SZ_FILTER_NO 0 | |
SZ_FILTER_YES inSize | |
SZ_FILTER_AUTO inSize | |
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) | |
*/ | |
enum ESzFilterMode | |
{ | |
SZ_FILTER_NO, | |
SZ_FILTER_YES, | |
SZ_FILTER_AUTO | |
}; | |
SRes Lzma86_Encode(Byte *dest, size_t *destLen, const Byte *src, size_t srcLen, | |
int level, UInt32 dictSize, int filterMode); | |
/* | |
Lzma86_GetUnpackSize: | |
In: | |
src - input data | |
srcLen - input data size | |
Out: | |
unpackSize - size of uncompressed stream | |
Return code: | |
SZ_OK - OK | |
SZ_ERROR_INPUT_EOF - Error in headers | |
*/ | |
SRes Lzma86_GetUnpackSize(const Byte *src, SizeT srcLen, UInt64 *unpackSize); | |
/* | |
Lzma86_Decode: | |
In: | |
dest - output data | |
destLen - output data size | |
src - input data | |
srcLen - input data size | |
Out: | |
destLen - processed output size | |
srcLen - processed input size | |
Return code: | |
SZ_OK - OK | |
SZ_ERROR_DATA - Data error | |
SZ_ERROR_MEM - Memory allocation error | |
SZ_ERROR_UNSUPPORTED - unsupported file | |
SZ_ERROR_INPUT_EOF - it needs more bytes in input buffer | |
*/ | |
SRes Lzma86_Decode(Byte *dest, SizeT *destLen, const Byte *src, SizeT *srcLen); | |
EXTERN_C_END | |
#endif |