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using System;↩
↩
namespace SevenZip.Compression.RangeCoder↩
{↩
struct BitTreeEncoder↩
{↩
BitEncoder[] Models;↩
int NumBitLevels;↩
↩
public BitTreeEncoder(int numBitLevels)↩
{↩
NumBitLevels = numBitLevels;↩
Models = new BitEncoder[1 << numBitLevels];↩
}↩
↩
public void Init()↩
{↩
for (uint i = 1; i < (1 << NumBitLevels); i++)↩
Models[i].Init();↩
}↩
↩
public void Encode(Encoder rangeEncoder, UInt32 symbol)↩
{↩
UInt32 m = 1;↩
for (int bitIndex = NumBitLevels; bitIndex > 0; )↩
{↩
bitIndex--;↩
UInt32 bit = (symbol >> bitIndex) & 1;↩
Models[m].Encode(rangeEncoder, bit);↩
m = (m << 1) | bit;↩
}↩
}↩
↩
public void ReverseEncode(Encoder rangeEncoder, UInt32 symbol)↩
{↩
UInt32 m = 1;↩
for (UInt32 i = 0; i < NumBitLevels; i++)↩
{↩
UInt32 bit = symbol & 1;↩
Models[m].Encode(rangeEncoder, bit);↩
m = (m << 1) | bit;↩
symbol >>= 1;↩
}↩
}↩
↩
public UInt32 GetPrice(UInt32 symbol)↩
{↩
UInt32 price = 0;↩
UInt32 m = 1;↩
for (int bitIndex = NumBitLevels; bitIndex > 0; )↩
{↩
bitIndex--;↩
UInt32 bit = (symbol >> bitIndex) & 1;↩
price += Models[m].GetPrice(bit);↩
m = (m << 1) + bit;↩
}↩
return price;↩
}↩
↩
public UInt32 ReverseGetPrice(UInt32 symbol)↩
{↩
UInt32 price = 0;↩
UInt32 m = 1;↩
for (int i = NumBitLevels; i > 0; i--)↩
{↩
UInt32 bit = symbol & 1;↩
symbol >>= 1;↩
price += Models[m].GetPrice(bit);↩
m = (m << 1) | bit;↩
}↩
return price;↩
}↩
↩
public static UInt32 ReverseGetPrice(BitEncoder[] Models, UInt32 startIndex,↩
int NumBitLevels, UInt32 symbol)↩
{↩
UInt32 price = 0;↩
UInt32 m = 1;↩
for (int i = NumBitLevels; i > 0; i--)↩
{↩
UInt32 bit = symbol & 1;↩
symbol >>= 1;↩
price += Models[startIndex + m].GetPrice(bit);↩
m = (m << 1) | bit;↩
}↩
return price;↩
}↩
↩
public static void ReverseEncode(BitEncoder[] Models, UInt32 startIndex,↩
Encoder rangeEncoder, int NumBitLevels, UInt32 symbol)↩
{↩
UInt32 m = 1;↩
for (int i = 0; i < NumBitLevels; i++)↩
{↩
UInt32 bit = symbol & 1;↩
Models[startIndex + m].Encode(rangeEncoder, bit);↩
m = (m << 1) | bit;↩
symbol >>= 1;↩
}↩
}↩
}↩
↩
struct BitTreeDecoder↩
{↩
BitDecoder[] Models;↩
int NumBitLevels;↩
↩
public BitTreeDecoder(int numBitLevels)↩
{↩
NumBitLevels = numBitLevels;↩
Models = new BitDecoder[1 << numBitLevels];↩
}↩
↩
public void Init()↩
{↩
for (uint i = 1; i < (1 << NumBitLevels); i++)↩
Models[i].Init();↩
}↩
↩
public uint Decode(RangeCoder.Decoder rangeDecoder)↩
{↩
uint m = 1;↩
for (int bitIndex = NumBitLevels; bitIndex > 0; bitIndex--)↩
m = (m << 1) + Models[m].Decode(rangeDecoder);↩
return m - ((uint)1 << NumBitLevels);↩
}↩
↩
public uint ReverseDecode(RangeCoder.Decoder rangeDecoder)↩
{↩
uint m = 1;↩
uint symbol = 0;↩
for (int bitIndex = 0; bitIndex < NumBitLevels; bitIndex++)↩
{↩
uint bit = Models[m].Decode(rangeDecoder);↩
m <<= 1;↩
m += bit;↩
symbol |= (bit << bitIndex);↩
}↩
return symbol;↩
}↩
↩
public static uint ReverseDecode(BitDecoder[] Models, UInt32 startIndex,↩
RangeCoder.Decoder rangeDecoder, int NumBitLevels)↩
{↩
uint m = 1;↩
uint symbol = 0;↩
for (int bitIndex = 0; bitIndex < NumBitLevels; bitIndex++)↩
{↩
uint bit = Models[startIndex + m].Decode(rangeDecoder);↩
m <<= 1;↩
m += bit;↩
symbol |= (bit << bitIndex);↩
}↩
return symbol;↩
}↩
}↩
}↩