procedure TForm1.BitBtn_StartClick(Sender: TObject);

Var euh : tstringlist;
  I, J: Integer;
  S: string;
  Resolution: TStringBuilder;
  ResIndex: Integer;
  ResolutionList: TStringList;

const
ALLOWED_CHARS = ['0' .. '9', '*']; // Only numbers and the *

begin
  Screen.Cursor := crHourGlass;
  BitBtn_Start.Enabled := false;
  Application.ProcessMessages;
  fVideoImage.VideoStart(ComboBox1.Items[ComboBox1.itemindex]);
  ResolutionList := TStringList.Create;
  FVideoImage.GetListOfSupportedVideoSizes(ResolutionList);

  Resolution := TStringBuilder.Create;
  ResIndex := 0; // If none is found, 0 will be used as default

  // Iterate through all the resolutions
  for I := 0 to ResolutionList.Count - 1 do
  begin
    S := ResolutionList[I]; // Store each resolution in a string
    Resolution.Clear; // Clear previous resolutions // Iterate through all the chars from current resolution
  for J := 0 to Length(S) do
  begin
  // Add each char to Resolution var in case they are valid ones
  if S[J] in ALLOWED_CHARS then
    Resolution.Append(S[J]);
  end; // Now Resolution has only valid chars, check it this is the ideal
  //if Resolution.ToString = '1280*720' then
  //if Resolution.ToString = '640*480' then

  if Resolution.ToString = edit1.text then
    begin
      ResIndex := I; // Get the index from the ideal resolution
      Break; // Get out of the loop
    end;
  end; // Set the resolution by using the ideal index


  ShowMessage (IntToStr(ResIndex)); // <<<<<< ohne hängt das Programm



  Button1.Enabled := true;
  BitBtn_Stop.Enabled := true;
  BitBtn_Properties.Enabled := true;
  BitBtn_StreamProp.Enabled := true;
  BitBtn_SaveBMP.Enabled := true;
  Screen.Cursor := crDefault;
  FVideoImage.SetResolutionByIndex(ResIndex);

end;