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1 /* Lzma86Enc.h -- LZMA + x86 (BCJ) Filter Encoder | |
2 2008-08-05 | |
3 Igor Pavlov | |
4 Public domain */ | |
5 | |
6 #ifndef __LZMA86ENC_H | |
7 #define __LZMA86ENC_H | |
8 | |
9 #include "../Types.h" | |
10 | |
11 /* | |
12 It's an example for LZMA + x86 Filter use. | |
13 You can use .lzma86 extension, if you write that stream to file. | |
14 .lzma86 header adds one additional byte to standard .lzma header. | |
15 .lzma86 header (14 bytes): | |
16 Offset Size Description | |
17 0 1 = 0 - no filter, | |
18 = 1 - x86 filter | |
19 1 1 lc, lp and pb in encoded form | |
20 2 4 dictSize (little endian) | |
21 6 8 uncompressed size (little endian) | |
22 | |
23 | |
24 Lzma86_Encode | |
25 ------------- | |
26 level - compression level: 0 <= level <= 9, the default value for "level" is 5. | |
27 | |
28 | |
29 dictSize - The dictionary size in bytes. The maximum value is | |
30 128 MB = (1 << 27) bytes for 32-bit version | |
31 1 GB = (1 << 30) bytes for 64-bit version | |
32 The default value is 16 MB = (1 << 24) bytes, for level = 5. | |
33 It's recommended to use the dictionary that is larger than 4 KB and | |
34 that can be calculated as (1 << N) or (3 << N) sizes. | |
35 For better compression ratio dictSize must be >= inSize. | |
36 | |
37 filterMode: | |
38 SZ_FILTER_NO - no Filter | |
39 SZ_FILTER_YES - x86 Filter | |
40 SZ_FILTER_AUTO - it tries both alternatives to select best. | |
41 Encoder will use 2 or 3 passes: | |
42 2 passes when FILTER_NO provides better compression. | |
43 3 passes when FILTER_YES provides better compression. | |
44 | |
45 Lzma86Encode allocates Data with MyAlloc functions. | |
46 RAM Requirements for compressing: | |
47 RamSize = dictionarySize * 11.5 + 6MB + FilterBlockSize | |
48 filterMode FilterBlockSize | |
49 SZ_FILTER_NO 0 | |
50 SZ_FILTER_YES inSize | |
51 SZ_FILTER_AUTO inSize | |
52 | |
53 | |
54 Return code: | |
55 SZ_OK - OK | |
56 SZ_ERROR_MEM - Memory allocation error | |
57 SZ_ERROR_PARAM - Incorrect paramater | |
58 SZ_ERROR_OUTPUT_EOF - output buffer overflow | |
59 SZ_ERROR_THREAD - errors in multithreading functions (only for Mt version) | |
60 */ | |
61 | |
62 enum ESzFilterMode | |
63 { | |
64 SZ_FILTER_NO, | |
65 SZ_FILTER_YES, | |
66 SZ_FILTER_AUTO | |
67 }; | |
68 | |
69 SRes Lzma86_Encode(Byte *dest, size_t *destLen, const Byte *src, size_t srcLen, | |
70 int level, UInt32 dictSize, int filterMode); | |
71 | |
72 #endif | |
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