--- a/misc/libphysfs/lzma/CS/7zip/Compress/RangeCoder/RangeCoderBit.cs Wed May 16 18:22:28 2018 +0200
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,117 +0,0 @@
-using System;
-
-namespace SevenZip.Compression.RangeCoder
-{
- struct BitEncoder
- {
- public const int kNumBitModelTotalBits = 11;
- public const uint kBitModelTotal = (1 << kNumBitModelTotalBits);
- const int kNumMoveBits = 5;
- const int kNumMoveReducingBits = 2;
- public const int kNumBitPriceShiftBits = 6;
-
- uint Prob;
-
- public void Init() { Prob = kBitModelTotal >> 1; }
-
- public void UpdateModel(uint symbol)
- {
- if (symbol == 0)
- Prob += (kBitModelTotal - Prob) >> kNumMoveBits;
- else
- Prob -= (Prob) >> kNumMoveBits;
- }
-
- public void Encode(Encoder encoder, uint symbol)
- {
- // encoder.EncodeBit(Prob, kNumBitModelTotalBits, symbol);
- // UpdateModel(symbol);
- uint newBound = (encoder.Range >> kNumBitModelTotalBits) * Prob;
- if (symbol == 0)
- {
- encoder.Range = newBound;
- Prob += (kBitModelTotal - Prob) >> kNumMoveBits;
- }
- else
- {
- encoder.Low += newBound;
- encoder.Range -= newBound;
- Prob -= (Prob) >> kNumMoveBits;
- }
- if (encoder.Range < Encoder.kTopValue)
- {
- encoder.Range <<= 8;
- encoder.ShiftLow();
- }
- }
-
- private static UInt32[] ProbPrices = new UInt32[kBitModelTotal >> kNumMoveReducingBits];
-
- static BitEncoder()
- {
- const int kNumBits = (kNumBitModelTotalBits - kNumMoveReducingBits);
- for (int i = kNumBits - 1; i >= 0; i--)
- {
- UInt32 start = (UInt32)1 << (kNumBits - i - 1);
- UInt32 end = (UInt32)1 << (kNumBits - i);
- for (UInt32 j = start; j < end; j++)
- ProbPrices[j] = ((UInt32)i << kNumBitPriceShiftBits) +
- (((end - j) << kNumBitPriceShiftBits) >> (kNumBits - i - 1));
- }
- }
-
- public uint GetPrice(uint symbol)
- {
- return ProbPrices[(((Prob - symbol) ^ ((-(int)symbol))) & (kBitModelTotal - 1)) >> kNumMoveReducingBits];
- }
- public uint GetPrice0() { return ProbPrices[Prob >> kNumMoveReducingBits]; }
- public uint GetPrice1() { return ProbPrices[(kBitModelTotal - Prob) >> kNumMoveReducingBits]; }
- }
-
- struct BitDecoder
- {
- public const int kNumBitModelTotalBits = 11;
- public const uint kBitModelTotal = (1 << kNumBitModelTotalBits);
- const int kNumMoveBits = 5;
-
- uint Prob;
-
- public void UpdateModel(int numMoveBits, uint symbol)
- {
- if (symbol == 0)
- Prob += (kBitModelTotal - Prob) >> numMoveBits;
- else
- Prob -= (Prob) >> numMoveBits;
- }
-
- public void Init() { Prob = kBitModelTotal >> 1; }
-
- public uint Decode(RangeCoder.Decoder rangeDecoder)
- {
- uint newBound = (uint)(rangeDecoder.Range >> kNumBitModelTotalBits) * (uint)Prob;
- if (rangeDecoder.Code < newBound)
- {
- rangeDecoder.Range = newBound;
- Prob += (kBitModelTotal - Prob) >> kNumMoveBits;
- if (rangeDecoder.Range < Decoder.kTopValue)
- {
- rangeDecoder.Code = (rangeDecoder.Code << 8) | (byte)rangeDecoder.Stream.ReadByte();
- rangeDecoder.Range <<= 8;
- }
- return 0;
- }
- else
- {
- rangeDecoder.Range -= newBound;
- rangeDecoder.Code -= newBound;
- Prob -= (Prob) >> kNumMoveBits;
- if (rangeDecoder.Range < Decoder.kTopValue)
- {
- rangeDecoder.Code = (rangeDecoder.Code << 8) | (byte)rangeDecoder.Stream.ReadByte();
- rangeDecoder.Range <<= 8;
- }
- return 1;
- }
- }
- }
-}