On delphi XE3 the "ImagingFmx.pas" by 4 error.

I'm trying to convert a frame of animated gif file to "FMX TImage".
The problem with this code is that there is no transparency in the alpha channel does not work.
Sorry for my bad inghlese.

procedure TForm5.Button1Click(Sender: TObject);
var
  I,y,x: LongInt;
  T: Int64;
  io:Tmemorystream;
  Dest, Src: PByte;
  Alpha: Byte;
begin
    try
      FImage := TMultiImage.Create;
      FImage2 := TMultiImage.Create;

      // Load all subimages in file
      T := ImagingUtility.GetTimeMicroseconds;
      FImage.LoadMultiFromFile('E:\espulso.gif');
      FImage2.LoadMultiFromFile('E:\espulso.gif');

      for I := 0 to FImage.ImageCount - 1 do
      begin
        FImage.ActiveImage := I;
        if not (FImage.Format in TImagingCanvas.GetSupportedFormats) then
          FImage.Format := ifA8R8G8B8;
        for Y := 0 to Height - 1 do
        begin
          Src := FImage.Scanline[y];
          Dest := FImage2.ScanLine[y];
          for X := 0 to Width - 1 do
          begin
            Alpha := Src[X * 4 + 3];
            Dest[X * 4 + 0] := Src[x * 4 + 0] * Alpha div 255;
            Dest[X * 4 + 1] := Src[x * 4 + 1] * Alpha div 255;
            Dest[X * 4 + 2] := Src[x * 4 + 2] * Alpha div 255;
            Dest[X * 4 + 3] := Alpha;
          end;
        end;
        io:=Tmemorystream.Create;
        FImage2.SaveToStream('gif',io);
        image1.Bitmap.LoadFromStream(io);
        ............
        break;

      end;
      // Activate first image and update UI
      FImage.ActiveImage := 0;
    except
      raise;
    end;

end;