1 /* LzmaLib.h -- LZMA library interface 2 2009-04-07 : Igor Pavlov : Public domain */ 3 4 #ifndef __LZMA_LIB_H 5 #define __LZMA_LIB_H 6 7 #include "Types.h" 8 9 #ifdef __cplusplus 10 extern "C" { 11 #endif 12 13 #define MY_STDAPI int MY_STD_CALL 14 15 #define LZMA_PROPS_SIZE 5 16 17 /* 18 RAM requirements for LZMA: 19 for compression: (dictSize * 11.5 + 6 MB) + state_size 20 for decompression: dictSize + state_size 21 state_size = (4 + (1.5 << (lc + lp))) KB 22 by default (lc=3, lp=0), state_size = 16 KB. 23 24 LZMA properties (5 bytes) format 25 Offset Size Description 26 0 1 lc, lp and pb in encoded form. 27 1 4 dictSize (little endian). 28 */ 29 30 /* 31 LzmaCompress 32 ------------ 33 34 outPropsSize - 35 In: the pointer to the size of outProps buffer; *outPropsSize = LZMA_PROPS_SIZE = 5. 36 Out: the pointer to the size of written properties in outProps buffer; *outPropsSize = LZMA_PROPS_SIZE = 5. 37 38 LZMA Encoder will use defult values for any parameter, if it is 39 -1 for any from: level, loc, lp, pb, fb, numThreads 40 0 for dictSize 41 42 level - compression level: 0 <= level <= 9; 43 44 level dictSize algo fb 45 0: 16 KB 0 32 46 1: 64 KB 0 32 47 2: 256 KB 0 32 48 3: 1 MB 0 32 49 4: 4 MB 0 32 50 5: 16 MB 1 32 51 6: 32 MB 1 32 52 7+: 64 MB 1 64 53 54 The default value for "level" is 5. 55 56 algo = 0 means fast method 57 algo = 1 means normal method 58 59 dictSize - The dictionary size in bytes. The maximum value is 60 128 MB = (1 << 27) bytes for 32-bit version 61 1 GB = (1 << 30) bytes for 64-bit version 62 The default value is 16 MB = (1 << 24) bytes. 63 It's recommended to use the dictionary that is larger than 4 KB and 64 that can be calculated as (1 << N) or (3 << N) sizes. 65 66 lc - The number of literal context bits (high bits of previous literal). 67 It can be in the range from 0 to 8. The default value is 3. 68 Sometimes lc=4 gives the gain for big files. 69 70 lp - The number of literal pos bits (low bits of current position for literals). 71 It can be in the range from 0 to 4. The default value is 0. 72 The lp switch is intended for periodical data when the period is equal to 2^lp. 73 For example, for 32-bit (4 bytes) periodical data you can use lp=2. Often it's 74 better to set lc=0, if you change lp switch. 75 76 pb - The number of pos bits (low bits of current position). 77 It can be in the range from 0 to 4. The default value is 2. 78 The pb switch is intended for periodical data when the period is equal 2^pb. 79 80 fb - Word size (the number of fast bytes). 81 It can be in the range from 5 to 273. The default value is 32. 82 Usually, a big number gives a little bit better compression ratio and 83 slower compression process. 84 85 numThreads - The number of thereads. 1 or 2. The default value is 2. 86 Fast mode (algo = 0) can use only 1 thread. 87 88 Out: 89 destLen - processed output size 90 Returns: 91 SZ_OK - OK 92 SZ_ERROR_MEM - Memory allocation error 93 SZ_ERROR_PARAM - Incorrect paramater 94 SZ_ERROR_OUTPUT_EOF - output buffer overflow 95 SZ_ERROR_THREAD - errors in multithreading functions (only for Mt version) 96 */ 97 98 MY_STDAPI LzmaCompress(unsigned char *dest, size_t *destLen, const unsigned char *src, size_t srcLen, 99 unsigned char *outProps, size_t *outPropsSize, /* *outPropsSize must be = 5 */ 100 int level, /* 0 <= level <= 9, default = 5 */ 101 unsigned dictSize, /* default = (1 << 24) */ 102 int lc, /* 0 <= lc <= 8, default = 3 */ 103 int lp, /* 0 <= lp <= 4, default = 0 */ 104 int pb, /* 0 <= pb <= 4, default = 2 */ 105 int fb, /* 5 <= fb <= 273, default = 32 */ 106 int numThreads /* 1 or 2, default = 2 */ 107 ); 108 109 /* 110 LzmaUncompress 111 -------------- 112 In: 113 dest - output data 114 destLen - output data size 115 src - input data 116 srcLen - input data size 117 Out: 118 destLen - processed output size 119 srcLen - processed input size 120 Returns: 121 SZ_OK - OK 122 SZ_ERROR_DATA - Data error 123 SZ_ERROR_MEM - Memory allocation arror 124 SZ_ERROR_UNSUPPORTED - Unsupported properties 125 SZ_ERROR_INPUT_EOF - it needs more bytes in input buffer (src) 126 */ 127 128 MY_STDAPI LzmaUncompress(unsigned char *dest, size_t *destLen, const unsigned char *src, SizeT *srcLen, 129 const unsigned char *props, size_t propsSize); 130 131 #ifdef __cplusplus 132 } 133 #endif 134 135 #endif 136
