/* LzmaLib.h -- LZMA library interface | |
2013-01-18 : Igor Pavlov : Public domain */ | |
#ifndef __LZMA_LIB_H | |
#define __LZMA_LIB_H | |
#include "7zTypes.h" | |
EXTERN_C_BEGIN | |
#define MY_STDAPI int MY_STD_CALL | |
#define LZMA_PROPS_SIZE 5 | |
/* | |
RAM requirements for LZMA: | |
for compression: (dictSize * 11.5 + 6 MB) + state_size | |
for decompression: dictSize + state_size | |
state_size = (4 + (1.5 << (lc + lp))) KB | |
by default (lc=3, lp=0), state_size = 16 KB. | |
LZMA properties (5 bytes) format | |
Offset Size Description | |
0 1 lc, lp and pb in encoded form. | |
1 4 dictSize (little endian). | |
*/ | |
/* | |
LzmaCompress | |
------------ | |
outPropsSize - | |
In: the pointer to the size of outProps buffer; *outPropsSize = LZMA_PROPS_SIZE = 5. | |
Out: the pointer to the size of written properties in outProps buffer; *outPropsSize = LZMA_PROPS_SIZE = 5. | |
LZMA Encoder will use defult values for any parameter, if it is | |
-1 for any from: level, loc, lp, pb, fb, numThreads | |
0 for dictSize | |
level - compression level: 0 <= level <= 9; | |
level dictSize algo fb | |
0: 16 KB 0 32 | |
1: 64 KB 0 32 | |
2: 256 KB 0 32 | |
3: 1 MB 0 32 | |
4: 4 MB 0 32 | |
5: 16 MB 1 32 | |
6: 32 MB 1 32 | |
7+: 64 MB 1 64 | |
The default value for "level" is 5. | |
algo = 0 means fast method | |
algo = 1 means normal method | |
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. | |
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. | |
lc - The number of literal context bits (high bits of previous literal). | |
It can be in the range from 0 to 8. The default value is 3. | |
Sometimes lc=4 gives the gain for big files. | |
lp - The number of literal pos bits (low bits of current position for literals). | |
It can be in the range from 0 to 4. The default value is 0. | |
The lp switch is intended for periodical data when the period is equal to 2^lp. | |
For example, for 32-bit (4 bytes) periodical data you can use lp=2. Often it's | |
better to set lc=0, if you change lp switch. | |
pb - The number of pos bits (low bits of current position). | |
It can be in the range from 0 to 4. The default value is 2. | |
The pb switch is intended for periodical data when the period is equal 2^pb. | |
fb - Word size (the number of fast bytes). | |
It can be in the range from 5 to 273. The default value is 32. | |
Usually, a big number gives a little bit better compression ratio and | |
slower compression process. | |
numThreads - The number of thereads. 1 or 2. The default value is 2. | |
Fast mode (algo = 0) can use only 1 thread. | |
Out: | |
destLen - processed output size | |
Returns: | |
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) | |
*/ | |
MY_STDAPI LzmaCompress(unsigned char *dest, size_t *destLen, const unsigned char *src, size_t srcLen, | |
unsigned char *outProps, size_t *outPropsSize, /* *outPropsSize must be = 5 */ | |
int level, /* 0 <= level <= 9, default = 5 */ | |
unsigned dictSize, /* default = (1 << 24) */ | |
int lc, /* 0 <= lc <= 8, default = 3 */ | |
int lp, /* 0 <= lp <= 4, default = 0 */ | |
int pb, /* 0 <= pb <= 4, default = 2 */ | |
int fb, /* 5 <= fb <= 273, default = 32 */ | |
int numThreads /* 1 or 2, default = 2 */ | |
); | |
/* | |
LzmaUncompress | |
-------------- | |
In: | |
dest - output data | |
destLen - output data size | |
src - input data | |
srcLen - input data size | |
Out: | |
destLen - processed output size | |
srcLen - processed input size | |
Returns: | |
SZ_OK - OK | |
SZ_ERROR_DATA - Data error | |
SZ_ERROR_MEM - Memory allocation arror | |
SZ_ERROR_UNSUPPORTED - Unsupported properties | |
SZ_ERROR_INPUT_EOF - it needs more bytes in input buffer (src) | |
*/ | |
MY_STDAPI LzmaUncompress(unsigned char *dest, size_t *destLen, const unsigned char *src, SizeT *srcLen, | |
const unsigned char *props, size_t propsSize); | |
EXTERN_C_END | |
#endif |