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1 /* Lzma86.h -- LZMA + x86 (BCJ) Filter
2 2013-01-18 : Igor Pavlov : Public domain */
3 
4 #ifndef __LZMA86_H
5 #define __LZMA86_H
6 
7 #include "7zTypes.h"
8 
9 EXTERN_C_BEGIN
10 
11 #define LZMA86_SIZE_OFFSET (1 + 5)
12 #define LZMA86_HEADER_SIZE (LZMA86_SIZE_OFFSET + 8)
13 
14 /*
15 It's an example for LZMA + x86 Filter use.
16 You can use .lzma86 extension, if you write that stream to file.
17 .lzma86 header adds one additional byte to standard .lzma header.
18 .lzma86 header (14 bytes):
19   Offset Size  Description
20     0     1    = 0 - no filter, pure LZMA
21                = 1 - x86 filter + LZMA
22     1     1    lc, lp and pb in encoded form
23     2     4    dictSize (little endian)
24     6     8    uncompressed size (little endian)
25 
26 
27 Lzma86_Encode
28 -------------
29 level - compression level: 0 <= level <= 9, the default value for "level" is 5.
30 
31 dictSize - The dictionary size in bytes. The maximum value is
32         128 MB = (1 << 27) bytes for 32-bit version
33           1 GB = (1 << 30) bytes for 64-bit version
34      The default value is 16 MB = (1 << 24) bytes, for level = 5.
35      It's recommended to use the dictionary that is larger than 4 KB and
36      that can be calculated as (1 << N) or (3 << N) sizes.
37      For better compression ratio dictSize must be >= inSize.
38 
39 filterMode:
40     SZ_FILTER_NO   - no Filter
41     SZ_FILTER_YES  - x86 Filter
42     SZ_FILTER_AUTO - it tries both alternatives to select best.
43               Encoder will use 2 or 3 passes:
44               2 passes when FILTER_NO provides better compression.
45               3 passes when FILTER_YES provides better compression.
46 
47 Lzma86Encode allocates Data with MyAlloc functions.
48 RAM Requirements for compressing:
49   RamSize = dictionarySize * 11.5 + 6MB + FilterBlockSize
50       filterMode     FilterBlockSize
51      SZ_FILTER_NO         0
52      SZ_FILTER_YES      inSize
53      SZ_FILTER_AUTO     inSize
54 
55 
56 Return code:
57   SZ_OK               - OK
58   SZ_ERROR_MEM        - Memory allocation error
59   SZ_ERROR_PARAM      - Incorrect paramater
60   SZ_ERROR_OUTPUT_EOF - output buffer overflow
61   SZ_ERROR_THREAD     - errors in multithreading functions (only for Mt version)
62 */
63 
64 enum ESzFilterMode
65 {
66   SZ_FILTER_NO,
67   SZ_FILTER_YES,
68   SZ_FILTER_AUTO
69 };
70 
71 SRes Lzma86_Encode(Byte *dest, size_t *destLen, const Byte *src, size_t srcLen,
72     int level, UInt32 dictSize, int filterMode);
73 
74 
75 /*
76 Lzma86_GetUnpackSize:
77   In:
78     src      - input data
79     srcLen   - input data size
80   Out:
81     unpackSize - size of uncompressed stream
82   Return code:
83     SZ_OK               - OK
84     SZ_ERROR_INPUT_EOF  - Error in headers
85 */
86 
87 SRes Lzma86_GetUnpackSize(const Byte *src, SizeT srcLen, UInt64 *unpackSize);
88 
89 /*
90 Lzma86_Decode:
91   In:
92     dest     - output data
93     destLen  - output data size
94     src      - input data
95     srcLen   - input data size
96   Out:
97     destLen  - processed output size
98     srcLen   - processed input size
99   Return code:
100     SZ_OK           - OK
101     SZ_ERROR_DATA  - Data error
102     SZ_ERROR_MEM   - Memory allocation error
103     SZ_ERROR_UNSUPPORTED - unsupported file
104     SZ_ERROR_INPUT_EOF - it needs more bytes in input buffer
105 */
106 
107 SRes Lzma86_Decode(Byte *dest, SizeT *destLen, const Byte *src, SizeT *srcLen);
108 
109 EXTERN_C_END
110 
111 #endif
112