Exemple #1
0
 public void Lzma2EncProps_Init()
 {
     mLzmaProps       = CLzmaEncProps.LzmaEncProps_Init();
     mNumTotalThreads = -1;
     mNumBlockThreads = -1;
     mBlockSize       = 0;
 }
Exemple #2
0
        /*
         * RAM requirements for LZMA:
         * for compression:   (dictSize * 11.5 + 6 MB) + state_size
         * for decompression: dictSize + state_size
         *  state_size = (4 + (1.5 << (lc + lp))) KB
         *  by default (lc=3, lp=0), state_size = 16 KB.
         *
         * LZMA properties (5 bytes) format
         *  Offset Size  Description
         *    0     1    lc, lp and pb in encoded form.
         *    1     4    dictSize (little endian).
         */

        /*
         * LzmaCompress
         * ------------
         *
         * outPropsSize -
         *   In:  the pointer to the size of outProps buffer; *outPropsSize = LZMA_PROPS_SIZE = 5.
         *   Out: the pointer to the size of written properties in outProps buffer; *outPropsSize = LZMA_PROPS_SIZE = 5.
         *
         * LZMA Encoder will use defult values for any parameter, if it is
         * -1  for any from: level, loc, lp, pb, fb, numThreads
         * 0  for dictSize
         *
         * level - compression level: 0 <= level <= 9;
         *
         * level dictSize algo  fb
         *  0:    16 KB   0    32
         *  1:    64 KB   0    32
         *  2:   256 KB   0    32
         *  3:     1 MB   0    32
         *  4:     4 MB   0    32
         *  5:    16 MB   1    32
         *  6:    32 MB   1    32
         *  7+:   64 MB   1    64
         *
         * The default value for "level" is 5.
         *
         * algo = 0 means fast method
         * algo = 1 means normal method
         *
         * 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.
         *   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.
         *
         * lc - The number of literal context bits (high bits of previous literal).
         *   It can be in the range from 0 to 8. The default value is 3.
         *   Sometimes lc=4 gives the gain for big files.
         *
         * lp - The number of literal pos bits (low bits of current position for literals).
         *   It can be in the range from 0 to 4. The default value is 0.
         *   The lp switch is intended for periodical data when the period is equal to 2^lp.
         *   For example, for 32-bit (4 bytes) periodical data you can use lp=2. Often it's
         *   better to set lc=0, if you change lp switch.
         *
         * pb - The number of pos bits (low bits of current position).
         *   It can be in the range from 0 to 4. The default value is 2.
         *   The pb switch is intended for periodical data when the period is equal 2^pb.
         *
         * fb - Word size (the number of fast bytes).
         *   It can be in the range from 5 to 273. The default value is 32.
         *   Usually, a big number gives a little bit better compression ratio and
         *   slower compression process.
         *
         * numThreads - The number of thereads. 1 or 2. The default value is 2.
         *   Fast mode (algo = 0) can use only 1 thread.
         *
         * Out:
         * destLen  - processed output size
         * Returns:
         * 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)
         */

        public static SRes LzmaCompress(
            P <byte> dest, ref long destLen,
            P <byte> src, long srcLen,
            P <byte> outProps, ref long outPropsSize, /* *outPropsSize must be = 5 */
            int level,                                /* 0 <= level <= 9, default = 5 */
            uint dictSize,                            /* default = (1 << 24) */
            int lc,                                   /* 0 <= lc <= 8, default = 3  */
            int lp,                                   /* 0 <= lp <= 4, default = 0  */
            int pb,                                   /* 0 <= pb <= 4, default = 2  */
            int fb,                                   /* 5 <= fb <= 273, default = 32 */
            int numThreads)                           /* 1 or 2, default = 2 */
        {
            var props = CLzmaEncProps.LzmaEncProps_Init();

            props.mLevel      = level;
            props.mDictSize   = dictSize;
            props.mLC         = lc;
            props.mLP         = lp;
            props.mPB         = pb;
            props.mFB         = fb;
            props.mNumThreads = numThreads;

            return(LzmaEncode(dest, ref destLen, src, srcLen, props, outProps, ref outPropsSize, false, null, ISzAlloc.SmallAlloc, ISzAlloc.BigAlloc));
        }