1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/other-licenses/7zstub/src/7zip/Compress/RangeCoder/RangeCoder.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,205 @@
1.4 +// Compress/RangeCoder/RangeCoder.h
1.5 +
1.6 +#ifndef __COMPRESS_RANGECODER_H
1.7 +#define __COMPRESS_RANGECODER_H
1.8 +
1.9 +#include "../../Common/InBuffer.h"
1.10 +#include "../../Common/OutBuffer.h"
1.11 +
1.12 +namespace NCompress {
1.13 +namespace NRangeCoder {
1.14 +
1.15 +const int kNumTopBits = 24;
1.16 +const UInt32 kTopValue = (1 << kNumTopBits);
1.17 +
1.18 +class CEncoder
1.19 +{
1.20 + UInt32 _cacheSize;
1.21 + Byte _cache;
1.22 +public:
1.23 + UInt64 Low;
1.24 + UInt32 Range;
1.25 + COutBuffer Stream;
1.26 + bool Create(UInt32 bufferSize) { return Stream.Create(bufferSize); }
1.27 +
1.28 + void SetStream(ISequentialOutStream *stream) { Stream.SetStream(stream); }
1.29 + void Init()
1.30 + {
1.31 + Stream.Init();
1.32 + Low = 0;
1.33 + Range = 0xFFFFFFFF;
1.34 + _cacheSize = 1;
1.35 + _cache = 0;
1.36 + }
1.37 +
1.38 + void FlushData()
1.39 + {
1.40 + // Low += 1;
1.41 + for(int i = 0; i < 5; i++)
1.42 + ShiftLow();
1.43 + }
1.44 +
1.45 + HRESULT FlushStream() { return Stream.Flush(); }
1.46 +
1.47 + void ReleaseStream() { Stream.ReleaseStream(); }
1.48 +
1.49 + void Encode(UInt32 start, UInt32 size, UInt32 total)
1.50 + {
1.51 + Low += start * (Range /= total);
1.52 + Range *= size;
1.53 + while (Range < kTopValue)
1.54 + {
1.55 + Range <<= 8;
1.56 + ShiftLow();
1.57 + }
1.58 + }
1.59 +
1.60 + void ShiftLow()
1.61 + {
1.62 + if ((UInt32)Low < (UInt32)0xFF000000 || (int)(Low >> 32) != 0)
1.63 + {
1.64 + Byte temp = _cache;
1.65 + do
1.66 + {
1.67 + Stream.WriteByte((Byte)(temp + (Byte)(Low >> 32)));
1.68 + temp = 0xFF;
1.69 + }
1.70 + while(--_cacheSize != 0);
1.71 + _cache = (Byte)((UInt32)Low >> 24);
1.72 + }
1.73 + _cacheSize++;
1.74 + Low = (UInt32)Low << 8;
1.75 + }
1.76 +
1.77 + void EncodeDirectBits(UInt32 value, int numTotalBits)
1.78 + {
1.79 + for (int i = numTotalBits - 1; i >= 0; i--)
1.80 + {
1.81 + Range >>= 1;
1.82 + if (((value >> i) & 1) == 1)
1.83 + Low += Range;
1.84 + if (Range < kTopValue)
1.85 + {
1.86 + Range <<= 8;
1.87 + ShiftLow();
1.88 + }
1.89 + }
1.90 + }
1.91 +
1.92 + void EncodeBit(UInt32 size0, UInt32 numTotalBits, UInt32 symbol)
1.93 + {
1.94 + UInt32 newBound = (Range >> numTotalBits) * size0;
1.95 + if (symbol == 0)
1.96 + Range = newBound;
1.97 + else
1.98 + {
1.99 + Low += newBound;
1.100 + Range -= newBound;
1.101 + }
1.102 + while (Range < kTopValue)
1.103 + {
1.104 + Range <<= 8;
1.105 + ShiftLow();
1.106 + }
1.107 + }
1.108 +
1.109 + UInt64 GetProcessedSize() { return Stream.GetProcessedSize() + _cacheSize + 4; }
1.110 +};
1.111 +
1.112 +class CDecoder
1.113 +{
1.114 +public:
1.115 + CInBuffer Stream;
1.116 + UInt32 Range;
1.117 + UInt32 Code;
1.118 + bool Create(UInt32 bufferSize) { return Stream.Create(bufferSize); }
1.119 +
1.120 + void Normalize()
1.121 + {
1.122 + while (Range < kTopValue)
1.123 + {
1.124 + Code = (Code << 8) | Stream.ReadByte();
1.125 + Range <<= 8;
1.126 + }
1.127 + }
1.128 +
1.129 + void SetStream(ISequentialInStream *stream) { Stream.SetStream(stream); }
1.130 + void Init()
1.131 + {
1.132 + Stream.Init();
1.133 + Code = 0;
1.134 + Range = 0xFFFFFFFF;
1.135 + for(int i = 0; i < 5; i++)
1.136 + Code = (Code << 8) | Stream.ReadByte();
1.137 + }
1.138 +
1.139 + void ReleaseStream() { Stream.ReleaseStream(); }
1.140 +
1.141 + UInt32 GetThreshold(UInt32 total)
1.142 + {
1.143 + return (Code) / ( Range /= total);
1.144 + }
1.145 +
1.146 + void Decode(UInt32 start, UInt32 size)
1.147 + {
1.148 + Code -= start * Range;
1.149 + Range *= size;
1.150 + Normalize();
1.151 + }
1.152 +
1.153 + UInt32 DecodeDirectBits(int numTotalBits)
1.154 + {
1.155 + UInt32 range = Range;
1.156 + UInt32 code = Code;
1.157 + UInt32 result = 0;
1.158 + for (int i = numTotalBits; i != 0; i--)
1.159 + {
1.160 + range >>= 1;
1.161 + /*
1.162 + result <<= 1;
1.163 + if (code >= range)
1.164 + {
1.165 + code -= range;
1.166 + result |= 1;
1.167 + }
1.168 + */
1.169 + UInt32 t = (code - range) >> 31;
1.170 + code -= range & (t - 1);
1.171 + result = (result << 1) | (1 - t);
1.172 +
1.173 + if (range < kTopValue)
1.174 + {
1.175 + code = (code << 8) | Stream.ReadByte();
1.176 + range <<= 8;
1.177 + }
1.178 + }
1.179 + Range = range;
1.180 + Code = code;
1.181 + return result;
1.182 + }
1.183 +
1.184 + UInt32 DecodeBit(UInt32 size0, UInt32 numTotalBits)
1.185 + {
1.186 + UInt32 newBound = (Range >> numTotalBits) * size0;
1.187 + UInt32 symbol;
1.188 + if (Code < newBound)
1.189 + {
1.190 + symbol = 0;
1.191 + Range = newBound;
1.192 + }
1.193 + else
1.194 + {
1.195 + symbol = 1;
1.196 + Code -= newBound;
1.197 + Range -= newBound;
1.198 + }
1.199 + Normalize();
1.200 + return symbol;
1.201 + }
1.202 +
1.203 + UInt64 GetProcessedSize() {return Stream.GetProcessedSize(); }
1.204 +};
1.205 +
1.206 +}}
1.207 +
1.208 +#endif
