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/* Lzma86.h -- LZMA + x86 (BCJ) Filter
2013-01-18 : Igor Pavlov : Public domain */
#ifndef __LZMA86_H
#define __LZMA86_H
#include "7zTypes.h"
EXTERN_C_BEGIN
#define LZMA86_SIZE_OFFSET (1 + 5)
#define LZMA86_HEADER_SIZE (LZMA86_SIZE_OFFSET + 8)
/*
It's an example for LZMA + x86 Filter use.
You can use .lzma86 extension, if you write that stream to file.
.lzma86 header adds one additional byte to standard .lzma header.
.lzma86 header (14 bytes):
Offset Size Description
0 1 = 0 - no filter, pure LZMA
= 1 - x86 filter + LZMA
1 1 lc, lp and pb in encoded form
2 4 dictSize (little endian)
6 8 uncompressed size (little endian)
Lzma86_Encode
-------------
level - compression level: 0 <= level <= 9, the default value for "level" is 5.
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, for level = 5.
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.
For better compression ratio dictSize must be >= inSize.
filterMode:
SZ_FILTER_NO - no Filter
SZ_FILTER_YES - x86 Filter
SZ_FILTER_AUTO - it tries both alternatives to select best.
Encoder will use 2 or 3 passes:
2 passes when FILTER_NO provides better compression.
3 passes when FILTER_YES provides better compression.
Lzma86Encode allocates Data with MyAlloc functions.
RAM Requirements for compressing:
RamSize = dictionarySize * 11.5 + 6MB + FilterBlockSize
filterMode FilterBlockSize
SZ_FILTER_NO 0
SZ_FILTER_YES inSize
SZ_FILTER_AUTO inSize
Return code:
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)
*/
enum ESzFilterMode
{
SZ_FILTER_NO,
SZ_FILTER_YES,
SZ_FILTER_AUTO
};
SRes Lzma86_Encode(Byte *dest, size_t *destLen, const Byte *src, size_t srcLen,
int level, UInt32 dictSize, int filterMode);
/*
Lzma86_GetUnpackSize:
In:
src - input data
srcLen - input data size
Out:
unpackSize - size of uncompressed stream
Return code:
SZ_OK - OK
SZ_ERROR_INPUT_EOF - Error in headers
*/
SRes Lzma86_GetUnpackSize(const Byte *src, SizeT srcLen, UInt64 *unpackSize);
/*
Lzma86_Decode:
In:
dest - output data
destLen - output data size
src - input data
srcLen - input data size
Out:
destLen - processed output size
srcLen - processed input size
Return code:
SZ_OK - OK
SZ_ERROR_DATA - Data error
SZ_ERROR_MEM - Memory allocation error
SZ_ERROR_UNSUPPORTED - unsupported file
SZ_ERROR_INPUT_EOF - it needs more bytes in input buffer
*/
SRes Lzma86_Decode(Byte *dest, SizeT *destLen, const Byte *src, SizeT *srcLen);
EXTERN_C_END
#endif
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