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/* LzmaLib.h -- LZMA library interface
2008-08-05
Igor Pavlov
Public domain */
#ifndef __LZMALIB_H
#define __LZMALIB_H
#include "Types.h"
#ifdef __cplusplus
#define MY_EXTERN_C extern "C"
#else
#define MY_EXTERN_C extern
#endif
#define MY_STDAPI MY_EXTERN_C 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);
#endif
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