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author | 2015-01-11 08:10:25 +0100 | |
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committer | 2015-01-11 08:10:25 +0100 | |
commit | 6a23c2f3b766cf4fc7028628f76b5ff9396383f0 (patch) | |
tree | a01e16637118ae0c80f337119898bdf18f081e24 /3rdparty/lzma/CS/7zip/Compress/RangeCoder/RangeCoderBitTree.cs | |
parent | 45ac9b351e0076c371de4c7453f59567b27b1cb6 (diff) |
Added full lzma sdk source (nw)
Diffstat (limited to '3rdparty/lzma/CS/7zip/Compress/RangeCoder/RangeCoderBitTree.cs')
-rw-r--r-- | 3rdparty/lzma/CS/7zip/Compress/RangeCoder/RangeCoderBitTree.cs | 157 |
1 files changed, 157 insertions, 0 deletions
diff --git a/3rdparty/lzma/CS/7zip/Compress/RangeCoder/RangeCoderBitTree.cs b/3rdparty/lzma/CS/7zip/Compress/RangeCoder/RangeCoderBitTree.cs new file mode 100644 index 00000000000..4b4506f9d19 --- /dev/null +++ b/3rdparty/lzma/CS/7zip/Compress/RangeCoder/RangeCoderBitTree.cs @@ -0,0 +1,157 @@ +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; + } + } +} |