| public static BitReverse ( uint code, int length ) : uint | ||
| code | uint | |
| length | int | |
| return | uint | |
private uint[] CalculateHuffmanCode()
{
uint[] numArray = new uint[0x11];
byte[] codeLengthArray = this.codeLengthArray;
for (int i = 0; i < codeLengthArray.Length; i++)
{
int index = codeLengthArray[i];
numArray[index]++;
}
numArray[0] = 0;
uint[] numArray2 = new uint[0x11];
uint num2 = 0;
for (int j = 1; j <= 0x10; j++)
{
numArray2[j] = (num2 + numArray[j - 1]) << 1;
}
uint[] numArray3 = new uint[0x120];
for (int k = 0; k < this.codeLengthArray.Length; k++)
{
int length = this.codeLengthArray[k];
if (length > 0)
{
numArray3[k] = DecodeHelper.BitReverse(numArray2[length], length);
numArray2[length]++;
}
}
return(numArray3);
}
// Calculate the huffman code for each character based on the code length for each character.
// This algorithm is described in standard RFC 1951
uint[] CalculateHuffmanCode()
{
uint[] bitLengthCount = new uint[17];
foreach (int codeLength in codeLengthArray)
{
bitLengthCount[codeLength]++;
}
bitLengthCount[0] = 0; // clear count for length 0
uint[] nextCode = new uint[17];
uint tempCode = 0;
for (int bits = 1; bits <= 16; bits++)
{
tempCode = (tempCode + bitLengthCount[bits - 1]) << 1;
nextCode[bits] = tempCode;
}
uint[] code = new uint[MaxLiteralTreeElements];
for (int i = 0; i < codeLengthArray.Length; i++)
{
int len = codeLengthArray[i];
if (len > 0)
{
code[i] = DecodeHelper.BitReverse(nextCode[len], len);
nextCode[len]++;
}
}
return(code);
}
