////////////////////////////////////////////////////////////////////
// Decode dynamic Huffman header
////////////////////////////////////////////////////////////////////
private void DecodeDynamicHuffamTrees()
{
// length of length/literal tree
Int32 LiteralLength = GetBits(5) + 257;
// length of distance tree
Int32 DistanceLength = GetBits(5) + 1;
// length of bit length tree
Int32 BitLengthReceived = GetBits(4) + 4;
// get bit length info from input stream
// note: array length must be 19 and not length received
Array.Clear(BitLengthArray, 0, BitLengthArray.Length);
for (Int32 Index = 0; Index < BitLengthReceived; Index++)
{
BitLengthArray[BitLengthOrder[Index]] = (Byte)GetBits(3);
}
// create bit length hauffman tree
BitLengthTree.BuildTree(BitLengthArray, 0, BitLengthArray.Length);
// create a combined array of length/literal and distance
Int32 TotalLength = LiteralLength + DistanceLength;
Array.Clear(LiteralDistanceArray, 0, LiteralDistanceArray.Length);
Byte LastCode = 0;
for (Int32 Ptr = 0; Ptr < TotalLength;)
{
// get next symbol from input stream
Int32 Symbol = ReadSymbol(BitLengthTree);
// switch based on symbol
switch (Symbol)
{
// symbol is less than 16 it is a literal
default:
LiteralDistanceArray[Ptr++] = LastCode = (Byte)Symbol;
continue;
case RepeatSymbol_3_6:
for (Int32 Count = GetBits(2) + 3; Count > 0; Count--)
{
LiteralDistanceArray[Ptr++] = LastCode;
}
continue;
case RepeatSymbol_3_10:
for (Int32 Count = GetBits(3) + 3; Count > 0; Count--)
{
LiteralDistanceArray[Ptr++] = 0;
}
continue;
case RepeatSymbol_11_138:
for (Int32 Count = GetBits(7) + 11; Count > 0; Count--)
{
LiteralDistanceArray[Ptr++] = 0;
}
continue;
}
}
// create the literal array and distance array
LiteralTree.SetDynamic();
LiteralTree.BuildTree(LiteralDistanceArray, 0, LiteralLength);
DistanceTree.SetDynamic();
DistanceTree.BuildTree(LiteralDistanceArray, LiteralLength, DistanceLength);
return;
}
/// <summary>
/// Decode dynamic Huffman header
/// </summary>
private void DecodeDynamicHuffamTrees()
{
// length of length/literal tree
int literalLength = GetBits(5) + 257;
// length of distance tree
int distanceLength = GetBits(5) + 1;
// length of bit length tree
int bitLengthReceived = GetBits(4) + 4;
// get bit length info from input stream
// note: array length must be 19 and not length received
Array.Clear(_bitLengthArray, 0, _bitLengthArray.Length);
for (int index = 0; index < bitLengthReceived; index++)
{
_bitLengthArray[BitLengthOrder[index]] = (byte)GetBits(3);
}
// create bit length hauffman tree
_bitLengthTree.BuildTree(_bitLengthArray, 0, _bitLengthArray.Length);
// create a combined array of length/literal and distance
int totalLength = literalLength + distanceLength;
Array.Clear(_literalDistanceArray, 0, _literalDistanceArray.Length);
byte lastCode = 0;
for (int ptr = 0; ptr < totalLength;)
{
// get next symbol from input stream
int symbol = ReadSymbol(_bitLengthTree);
// switch based on symbol
switch (symbol)
{
// symbol is less than 16 it is a literal
default:
_literalDistanceArray[ptr++] = lastCode = (byte)symbol;
continue;
case RepeatSymbol_3_6:
for (int count = GetBits(2) + 3; count > 0; count--)
{
_literalDistanceArray[ptr++] = lastCode;
}
continue;
case RepeatSymbol_3_10:
for (int count = GetBits(3) + 3; count > 0; count--)
{
_literalDistanceArray[ptr++] = 0;
}
continue;
case RepeatSymbol_11_138:
for (int count = GetBits(7) + 11; count > 0; count--)
{
_literalDistanceArray[ptr++] = 0;
}
continue;
}
}
// create the literal array and distance array
_literalTree.SetDynamic();
_literalTree.BuildTree(_literalDistanceArray, 0, literalLength);
_distanceTree.SetDynamic();
_distanceTree.BuildTree(_literalDistanceArray, literalLength, distanceLength);
}
