private bool ProcessCode(int code, byte[] buffer, int offset, int count, ref int read)
{
if (code < this._codeTable.Count)
{
LzwDecompressStream.Sequence sequence = this._codeTable[code];
if (sequence.IsStopCode)
{
return(false);
}
if (sequence.IsClearCode)
{
this.InitCodeTable();
return(true);
}
this._remainingBytes = LzwDecompressStream.CopySequenceToBuffer(sequence.Bytes, buffer, offset, count, ref read);
if (this._prevCode >= 0)
{
this._codeTable.Add(this._codeTable[this._prevCode].Append(sequence.Bytes[0]));
}
}
else
{
LzwDecompressStream.Sequence sequence1 = this._codeTable[this._prevCode];
LzwDecompressStream.Sequence local = sequence1;
//int num = (int)local.Bytes[0];
LzwDecompressStream.Sequence sequence2 = (local).Append(/*(byte)num*/ local.Bytes[0]);
this._codeTable.Add(sequence2);
this._remainingBytes = LzwDecompressStream.CopySequenceToBuffer(sequence2.Bytes, buffer, offset, count, ref read);
}
this._prevCode = code;
return(true);
}
private void FlushRemainingBytes(byte[] buffer, int offset, int count, ref int read)
{
if (this._remainingBytes == null)
{
return;
}
this._remainingBytes = LzwDecompressStream.CopySequenceToBuffer(this._remainingBytes, buffer, offset, count, ref read);
}
private static async Task DecompressAllFramesAsync(string path)
{
using (var fileStream = File.OpenRead(path))
{
var gif = await GifDataStream.ReadAsync(fileStream);
for (int i = 0; i < gif.Frames.Count; i++)
{
var frame = gif.Frames[i];
fileStream.Seek(frame.ImageData.CompressedDataStartOffset, SeekOrigin.Begin);
using (var ms = new MemoryStream())
{
await GifHelpers.CopyDataBlocksToStreamAsync(fileStream, ms);
using (var lzwStream = new LzwDecompressStream(ms.GetBuffer(), frame.ImageData.LzwMinimumCodeSize))
using (var indOutStream = File.OpenWrite($"{path}.{i}.ind"))
{
await lzwStream.CopyToAsync(indOutStream);
}
}
}
}
}
private async Task<Stream> GetIndexStreamAsync(GifFrame frame, CancellationToken cancellationToken)
{
var data = frame.ImageData;
cancellationToken.ThrowIfCancellationRequested();
_sourceStream.Seek(data.CompressedDataStartOffset, SeekOrigin.Begin);
using (var ms = new MemoryStream(_indexStreamBuffer))
{
await GifHelpers.CopyDataBlocksToStreamAsync(_sourceStream, ms, cancellationToken).ConfigureAwait(false);
}
var lzwStream = new LzwDecompressStream(_indexStreamBuffer, data.LzwMinimumCodeSize);
return lzwStream;
}