b24e7fce |
1 | /* LzmaLib.h -- LZMA library interface |
2 | 2013-01-18 : Igor Pavlov : Public domain */ |
3 | |
4 | #ifndef __LZMA_LIB_H |
5 | #define __LZMA_LIB_H |
6 | |
7 | #include "7zTypes.h" |
8 | |
9 | EXTERN_C_BEGIN |
10 | |
11 | #define MY_STDAPI int MY_STD_CALL |
12 | |
13 | #define LZMA_PROPS_SIZE 5 |
14 | |
15 | /* |
16 | RAM requirements for LZMA: |
17 | for compression: (dictSize * 11.5 + 6 MB) + state_size |
18 | for decompression: dictSize + state_size |
19 | state_size = (4 + (1.5 << (lc + lp))) KB |
20 | by default (lc=3, lp=0), state_size = 16 KB. |
21 | |
22 | LZMA properties (5 bytes) format |
23 | Offset Size Description |
24 | 0 1 lc, lp and pb in encoded form. |
25 | 1 4 dictSize (little endian). |
26 | */ |
27 | |
28 | /* |
29 | LzmaCompress |
30 | ------------ |
31 | |
32 | outPropsSize - |
33 | In: the pointer to the size of outProps buffer; *outPropsSize = LZMA_PROPS_SIZE = 5. |
34 | Out: the pointer to the size of written properties in outProps buffer; *outPropsSize = LZMA_PROPS_SIZE = 5. |
35 | |
36 | LZMA Encoder will use defult values for any parameter, if it is |
37 | -1 for any from: level, loc, lp, pb, fb, numThreads |
38 | 0 for dictSize |
39 | |
40 | level - compression level: 0 <= level <= 9; |
41 | |
42 | level dictSize algo fb |
43 | 0: 16 KB 0 32 |
44 | 1: 64 KB 0 32 |
45 | 2: 256 KB 0 32 |
46 | 3: 1 MB 0 32 |
47 | 4: 4 MB 0 32 |
48 | 5: 16 MB 1 32 |
49 | 6: 32 MB 1 32 |
50 | 7+: 64 MB 1 64 |
51 | |
52 | The default value for "level" is 5. |
53 | |
54 | algo = 0 means fast method |
55 | algo = 1 means normal method |
56 | |
57 | dictSize - The dictionary size in bytes. The maximum value is |
58 | 128 MB = (1 << 27) bytes for 32-bit version |
59 | 1 GB = (1 << 30) bytes for 64-bit version |
60 | The default value is 16 MB = (1 << 24) bytes. |
61 | It's recommended to use the dictionary that is larger than 4 KB and |
62 | that can be calculated as (1 << N) or (3 << N) sizes. |
63 | |
64 | lc - The number of literal context bits (high bits of previous literal). |
65 | It can be in the range from 0 to 8. The default value is 3. |
66 | Sometimes lc=4 gives the gain for big files. |
67 | |
68 | lp - The number of literal pos bits (low bits of current position for literals). |
69 | It can be in the range from 0 to 4. The default value is 0. |
70 | The lp switch is intended for periodical data when the period is equal to 2^lp. |
71 | For example, for 32-bit (4 bytes) periodical data you can use lp=2. Often it's |
72 | better to set lc=0, if you change lp switch. |
73 | |
74 | pb - The number of pos bits (low bits of current position). |
75 | It can be in the range from 0 to 4. The default value is 2. |
76 | The pb switch is intended for periodical data when the period is equal 2^pb. |
77 | |
78 | fb - Word size (the number of fast bytes). |
79 | It can be in the range from 5 to 273. The default value is 32. |
80 | Usually, a big number gives a little bit better compression ratio and |
81 | slower compression process. |
82 | |
83 | numThreads - The number of thereads. 1 or 2. The default value is 2. |
84 | Fast mode (algo = 0) can use only 1 thread. |
85 | |
86 | Out: |
87 | destLen - processed output size |
88 | Returns: |
89 | SZ_OK - OK |
90 | SZ_ERROR_MEM - Memory allocation error |
91 | SZ_ERROR_PARAM - Incorrect paramater |
92 | SZ_ERROR_OUTPUT_EOF - output buffer overflow |
93 | SZ_ERROR_THREAD - errors in multithreading functions (only for Mt version) |
94 | */ |
95 | |
96 | MY_STDAPI LzmaCompress(unsigned char *dest, size_t *destLen, const unsigned char *src, size_t srcLen, |
97 | unsigned char *outProps, size_t *outPropsSize, /* *outPropsSize must be = 5 */ |
98 | int level, /* 0 <= level <= 9, default = 5 */ |
99 | unsigned dictSize, /* default = (1 << 24) */ |
100 | int lc, /* 0 <= lc <= 8, default = 3 */ |
101 | int lp, /* 0 <= lp <= 4, default = 0 */ |
102 | int pb, /* 0 <= pb <= 4, default = 2 */ |
103 | int fb, /* 5 <= fb <= 273, default = 32 */ |
104 | int numThreads /* 1 or 2, default = 2 */ |
105 | ); |
106 | |
107 | /* |
108 | LzmaUncompress |
109 | -------------- |
110 | In: |
111 | dest - output data |
112 | destLen - output data size |
113 | src - input data |
114 | srcLen - input data size |
115 | Out: |
116 | destLen - processed output size |
117 | srcLen - processed input size |
118 | Returns: |
119 | SZ_OK - OK |
120 | SZ_ERROR_DATA - Data error |
121 | SZ_ERROR_MEM - Memory allocation arror |
122 | SZ_ERROR_UNSUPPORTED - Unsupported properties |
123 | SZ_ERROR_INPUT_EOF - it needs more bytes in input buffer (src) |
124 | */ |
125 | |
126 | MY_STDAPI LzmaUncompress(unsigned char *dest, size_t *destLen, const unsigned char *src, SizeT *srcLen, |
127 | const unsigned char *props, size_t propsSize); |
128 | |
129 | EXTERN_C_END |
130 | |
131 | #endif |