protected void DecodeDynHeader(out DecompressorHuffmanTree lengthTree, out DecompressorHuffmanTree distanceTree)
{
byte[] arrDecoderCodeLengths;
byte[] arrResultingCodeLengths;
byte bLastSymbol = 0;
int iLengthsCount = ReadBits(5);
int iDistancesCount = ReadBits(5);
int iCodeLengthsCount = ReadBits(4);
if (iLengthsCount < 0 || iDistancesCount < 0 || iCodeLengthsCount < 0)
throw new FormatException("Wrong dynamic huffman codes.");
iLengthsCount += 257;
iDistancesCount += 1;
int iResultingCodeLengthsCount = iLengthsCount + iDistancesCount;
arrResultingCodeLengths = new byte[iResultingCodeLengthsCount];
arrDecoderCodeLengths = new byte[19];
iCodeLengthsCount += 4;
int iCurrentCode = 0;
while (iCurrentCode < iCodeLengthsCount)
{
int len = ReadBits(3);
if (len < 0)
throw new FormatException("Wrong dynamic huffman codes.");
arrDecoderCodeLengths[BitUtils.DEF_HUFFMAN_DYNTREE_CODELENGTHS_ORDER[iCurrentCode++]] =
(byte)len;
}
DecompressorHuffmanTree treeInternalDecoder = new
DecompressorHuffmanTree(arrDecoderCodeLengths);
iCurrentCode = 0;
for (; ; )
{
int symbol;
bool bNeedBreak = false;
while (((symbol = treeInternalDecoder.UnpackSymbol(this)) & ~15) == 0)
{
arrResultingCodeLengths[iCurrentCode++] = bLastSymbol = (byte)symbol;
if (iCurrentCode == iResultingCodeLengthsCount)
{
bNeedBreak = true;
break;
}
}
if (bNeedBreak) break;
if (symbol < 0)
throw new FormatException("Wrong dynamic huffman codes.");
if (symbol >= 17)
{
bLastSymbol = 0;
}
else if (iCurrentCode == 0)
{
throw new FormatException("Wrong dynamic huffman codes.");
}
int m_iRepSymbol = symbol - 16;
int bits = DEF_HUFFMAN_DYNTREE_REPEAT_BITS[m_iRepSymbol];
int count = ReadBits(bits);
if (count < 0)
throw new FormatException("Wrong dynamic huffman codes.");
count += DEF_HUFFMAN_DYNTREE_REPEAT_MINIMUMS[m_iRepSymbol];
if (iCurrentCode + count > iResultingCodeLengthsCount)
throw new FormatException("Wrong dynamic huffman codes.");
while (count-- > 0)
{
arrResultingCodeLengths[iCurrentCode++] = bLastSymbol;
}
if (iCurrentCode == iResultingCodeLengthsCount) break;
}
byte[] tempArray = new byte[iLengthsCount];
Array.Copy(arrResultingCodeLengths, 0, tempArray, 0, iLengthsCount);
lengthTree = new DecompressorHuffmanTree(tempArray);
tempArray = new byte[iDistancesCount];
Array.Copy(arrResultingCodeLengths, iLengthsCount, tempArray, 0, iDistancesCount);
distanceTree = new DecompressorHuffmanTree(tempArray);
}
