1 package SevenZip.Compression.RangeCoder;

     2 import java.io.IOException;

     3 

     4 public class Encoder

     5 {

     6 	static final int kTopMask = ~((1 << 24) - 1);

     7 	

     8 	static final int kNumBitModelTotalBits = 11;

     9 	static final int kBitModelTotal = (1 << kNumBitModelTotalBits);

    10 	static final int kNumMoveBits = 5;

    11 	

    12 	java.io.OutputStream Stream;

    13 

    14 	long Low;

    15 	int Range;

    16 	int _cacheSize;

    17 	int _cache;

    18 	

    19 	long _position;

    20 	

    21 	public void SetStream(java.io.OutputStream stream)

    22 	{

    23 		Stream = stream;

    24 	}

    25 	

    26 	public void ReleaseStream()

    27 	{

    28 		Stream = null;

    29 	}

    30 	

    31 	public void Init()

    32 	{

    33 		_position = 0;

    34 		Low = 0;

    35 		Range = -1;

    36 		_cacheSize = 1;

    37 		_cache = 0;

    38 	}

    39 	

    40 	public void FlushData() throws IOException

    41 	{

    42 		for (int i = 0; i < 5; i++)

    43 			ShiftLow();

    44 	}

    45 	

    46 	public void FlushStream() throws IOException

    47 	{

    48 		Stream.flush();

    49 	}

    50 	

    51 	public void ShiftLow() throws IOException

    52 	{

    53 		int LowHi = (int)(Low >>> 32);

    54 		if (LowHi != 0 || Low < 0xFF000000L)

    55 		{

    56 			_position += _cacheSize;

    57 			int temp = _cache;

    58 			do

    59 			{

    60 				Stream.write(temp + LowHi);

    61 				temp = 0xFF;

    62 			}

    63 			while(--_cacheSize != 0);

    64 			_cache = (((int)Low) >>> 24);

    65 		}

    66 		_cacheSize++;

    67 		Low = (Low & 0xFFFFFF) << 8;

    68 	}

    69 	

    70 	public void EncodeDirectBits(int v, int numTotalBits) throws IOException

    71 	{

    72 		for (int i = numTotalBits - 1; i >= 0; i--)

    73 		{

    74 			Range >>>= 1;

    75 			if (((v >>> i) & 1) == 1)

    76 				Low += Range;

    77 			if ((Range & Encoder.kTopMask) == 0)

    78 			{

    79 				Range <<= 8;

    80 				ShiftLow();

    81 			}

    82 		}

    83 	}

    84 	

    85 	

    86 	public long GetProcessedSizeAdd()

    87 	{

    88 		return _cacheSize + _position + 4;

    89 	}

    90 	

    91 	

    92 	

    93 	static final int kNumMoveReducingBits = 2;

    94 	public static final int kNumBitPriceShiftBits = 6;

    95 	

    96 	public static void InitBitModels(short []probs)

    97 	{

    98 		for (int i = 0; i < probs.length; i++)

    99 			probs[i] = (kBitModelTotal >>> 1);

   100 	}

   101 	

   102 	public void Encode(short []probs, int index, int symbol) throws IOException

   103 	{

   104 		int prob = probs[index];

   105 		int newBound = (Range >>> kNumBitModelTotalBits) * prob;

   106 		if (symbol == 0)

   107 		{

   108 			Range = newBound;

   109 			probs[index] = (short)(prob + ((kBitModelTotal - prob) >>> kNumMoveBits));

   110 		}

   111 		else

   112 		{

   113 			Low += (newBound & 0xFFFFFFFFL);

   114 			Range -= newBound;

   115 			probs[index] = (short)(prob - ((prob) >>> kNumMoveBits));

   116 		}

   117 		if ((Range & kTopMask) == 0)

   118 		{

   119 			Range <<= 8;

   120 			ShiftLow();

   121 		}

   122 	}

   123 	

   124 	private static int[] ProbPrices = new int[kBitModelTotal >>> kNumMoveReducingBits];

   125 	

   126 	static

   127 	{

   128 		int kNumBits = (kNumBitModelTotalBits - kNumMoveReducingBits);

   129 		for (int i = kNumBits - 1; i >= 0; i--)

   130 		{

   131 			int start = 1 << (kNumBits - i - 1);

   132 			int end = 1 << (kNumBits - i);

   133 			for (int j = start; j < end; j++)

   134 				ProbPrices[j] = (i << kNumBitPriceShiftBits) +

   135 						(((end - j) << kNumBitPriceShiftBits) >>> (kNumBits - i - 1));

   136 		}

   137 	}

   138 	

   139 	static public int GetPrice(int Prob, int symbol)

   140 	{

   141 		return ProbPrices[(((Prob - symbol) ^ ((-symbol))) & (kBitModelTotal - 1)) >>> kNumMoveReducingBits];

   142 	}

   143 	static public int GetPrice0(int Prob)

   144 	{ 

   145 		return ProbPrices[Prob >>> kNumMoveReducingBits]; 

   146 	}

   147 	static public int GetPrice1(int Prob)

   148 	{ 

   149 		return ProbPrices[(kBitModelTotal - Prob) >>> kNumMoveReducingBits]; 

   150 	}

   151 }