(Des)Compactação com ZLib

procedure TForm1.CompressFiles(Files : TStrings; const Filename : String);
var
  InFile, OutFile, TmpFile : TFileStream;
  Compr : TCompressionStream;
  I, L : Integer;
  S : String;
begin
  if Files.Count > 0 then
  begin
OutFile := TFileStream.Create(Filename,fmCreate);
try
  { the number of files }
  L := Files.Count;
  OutFile.Write(L,SizeOf(L));
  for I := 0 to Files.Count-1 do
  begin
InFile := TFileStream.Create(Files[I],fmOpenRead);
try
  { the original filename }
  S := ExtractFilename(Files[I]);
  L := Length(S);
  OutFile.Write(L,SizeOf(L));
  OutFile.Write(S[1],L);
  { the original filesize }
  L := InFile.Size;
  OutFile.Write(L,SizeOf(L));
  { compress and store the file temporary}
  TmpFile := TFileStream.Create(´tmp´,fmCreate);
  Compr := TCompressionStream.Create(clMax,TmpFile);
  try
Compr.CopyFrom(InFile,L);
  finally
Compr.Free;
TmpFile.Free;
  end;
  { append the Compressed file to the destination file }
  TmpFile := TFileStream.Create(´tmp´,fmOpenRead);
  try
OutFile.CopyFrom(TmpFile,0);
  finally
TmpFile.Free;
  end;
finally
  InFile.Free;
end;
  end;
finally
  OutFile.Free;
end;
DeleteFile(´tmp´);
  end;
end;

procedure TForm1.DecompressFiles(const Filename, DestDirectory : String);
var
  Dest,S: String;
  Decompr: TDecompressionStream;
  InFile, OutFile: TFilestream;
  I,L,C: Integer;
begin
  Dest   := IncludeTrailingPathDelimiter(DestDirectory);
  InFile := TFileStream.Create(Filename,fmOpenRead);
  try
{ number of files }
InFile.Read(C,SizeOf(C));
for I := 1 to C do
begin
  { read filename }
  InFile.Read(L,SizeOf(L));
  SetLength(S,L);
  InFile.Read(S[1],L);
  { read filesize }
  InFile.Read(L,SizeOf(L));
  { Decompress the files and store it }
  S := Dest+S; //include the path
  OutFile := TFileStream.Create(Dest+S,fmCreate);
  Decompr := TDecompressionStream.Create(InFile);
  try
OutFile.CopyFrom(Decompr,L);
  finally
OutFile.Free;
Decompr.Free;
  end;
end;
  finally
InFile.Free;
  end;
end;