/// <summary>
///
/// </summary>
///
/// <param name="fileStreamIn"></param>
/// <param name="fileStreamOut"></param>
/// <param name="prefixTree"></param>
public static void Decompress(Stream fileStreamIn, Stream fileStreamOut, PrefixTree prefixTree)
{
BitStream bitStream = new BitStream(fileStreamIn);
prefixTree.InitializeTrace();
int bit;
while ((bit = bitStream.ReadBit()) != -1)
{
byte symbol = prefixTree.Trace(bit);
if (symbol != 0)
{
fileStreamOut.WriteByte(symbol);
}
}
}
/// <summary>
///
/// </summary>
///
/// <param name="fileStreamIn"></param>
/// <param name="fileStreamOut"></param>
/// <param name="prefixTree"></param>
public static void Compress(Stream fileStreamIn, Stream fileStreamOut, PrefixTree prefixTree)
{
// Get the symbol codes from the prefix tree.
string[] symbolCodes = prefixTree.GetSymbolCodes();
BitStream bitStream = new BitStream(fileStreamOut);
int symbol;
while ((symbol = fileStreamIn.ReadByte()) != -1)
{
string code = symbolCodes[symbol];
foreach (char character in code)
{
int bit = (character == '1') ? 1 : 0;
bitStream.WriteBit(bit);
}
}
bitStream.Finish();
}
/// <summary>
/// The application's entry point.
/// </summary>
///
/// <param name="args">The commnad line arguments.</param>
static void Main(string[] args)
{
FileStream fileStreamIn = null;
FileStream fileStreamOut = null;
try
{
// ===== Build the prefix tree ======
// Open the input (uncompressed) file.
fileStreamIn = new FileStream(args[0], FileMode.Open);
// Count the character weights in the stream.
long[] symbolWeights = Huffman.CountSymbolWeights(fileStreamIn);
Console.WriteLine(ArrayToString(symbolWeights));
// Build the prefix tree from the character weights.
PrefixTree prefixTree = new PrefixTree(symbolWeights);
// Close the input (uncompressed) file.
fileStreamIn.Close();
// ====== Compress file ======
// Open the input (uncompressed) file.
fileStreamIn = new FileStream(args[0], FileMode.Open);
// Open the output (compressed) file.
fileStreamOut = new FileStream(args[1], FileMode.Create);
Huffman.Compress(fileStreamIn, fileStreamOut, prefixTree);
// Close the input (uncompressed) file.
fileStreamIn.Close();
// Close the output (compressed) file.
fileStreamOut.Close();
// ===== Decompress the file =====
// Open the input (compressed) file
fileStreamIn = new FileStream(args[1], FileMode.Open);
// Open the output (Uncompressed) file.
fileStreamOut = new FileStream(args[2], FileMode.Create);
Huffman.Decompress(fileStreamIn, fileStreamOut, prefixTree);
}
catch
{
}
finally
{
// Close the input file.
if (fileStreamIn != null)
{
fileStreamIn.Close();
}
// Close the output file.
if (fileStreamOut != null)
{
fileStreamOut.Close();
}
}
}
