public void Encode(Stream stream)
{
var first = true;
int suffix = Nullcode;
var codeTable = new Dictionary<string, int>();
var codeSize = (byte) (this.colorsDepth + 1);
var availableCode = this.endCode + 1;
var bitEncoder = new BitEncoder(codeSize);
stream.WriteByte(this.colorsDepth);
bitEncoder.Add(this.clearCode);
var releaseCount = 0;
while (releaseCount < this.imageData.Length)
{
if (first)
{
suffix = this.imageData[releaseCount++];
if (releaseCount == this.imageData.Length)
{
this.EncodeBits(stream, bitEncoder, suffix);
break;
}
first = false;
continue;
}
var prefix = suffix;
suffix = this.imageData[releaseCount++];
var entry = string.Format("{0},{1}", prefix, suffix);
if (!codeTable.ContainsKey(entry))
{
bitEncoder.Add(prefix);
codeTable.Add(entry, availableCode++);
if (availableCode > (MaxStackSize - 3))
{
codeTable.Clear();
this.colorsDepth = this.initialColorsDepth;
codeSize = (byte) (this.colorsDepth + 1);
availableCode = this.endCode + 1;
bitEncoder.Add(this.clearCode);
bitEncoder.InitialBit = codeSize;
}
else if (availableCode > (1 << codeSize))
{
this.colorsDepth++;
codeSize = (byte) (this.colorsDepth + 1);
bitEncoder.InitialBit = codeSize;
}
if (bitEncoder.Length >= 255)
{
stream.WriteByte(255);
stream.Write(bitEncoder.ToArray(), 0, 255);
if (bitEncoder.Length > 255)
{
var leftBuffer = new byte[bitEncoder.Length - 255];
bitEncoder.CopyTo(255, leftBuffer, 0, leftBuffer.Length);
bitEncoder.Clear();
bitEncoder.AddRange(leftBuffer);
}
else
{
bitEncoder.Clear();
}
}
}
else
{
suffix = codeTable[entry];
}
if (releaseCount != this.imageData.Length)
{
continue;
}
this.EncodeBits(stream, bitEncoder, suffix);
break;
}
}
private void EncodeBits(Stream stream, BitEncoder bitEncoder, int suffix)
{
bitEncoder.Add(suffix);
bitEncoder.Add(this.endCode);
bitEncoder.End();
if (bitEncoder.Length > 255)
{
var leftBuffer = new byte[bitEncoder.Length - 255];
bitEncoder.CopyTo(255, leftBuffer, 0, leftBuffer.Length);
bitEncoder.Clear();
bitEncoder.AddRange(leftBuffer);
stream.WriteByte((byte) leftBuffer.Length);
stream.WriteBytes(leftBuffer);
}
else
{
stream.WriteByte((byte) (bitEncoder.Length));
stream.WriteBytes(bitEncoder.ToArray());
bitEncoder.Clear();
}
}
