uses MPlayer; 
 
function Dauer(MIDI: TFilename; twc: TWinControl): string; 
const 
  mn = 60; 
  st = 3600; 
var 
  Mediaplayer: TMediaplayer; 
  zt, hr: integer; 
begin 
  Mediaplayer := TMediaplayer.create(twc); 
  Mediaplayer.parent := twc; 
  //------ eigentliche Routine ---------------------------------- 
  Mediaplayer.Filename := MIDI; 
  Mediaplayer.open; 
  Mediaplayer.Timeformat := tfMilliseconds; 
  zt := round(Mediaplayer.Length / 1000); 
  hr := zt div st; 
  dec(zt, hr * st); 
  Result := Format('%.2d:%.2d:%.2d', [hr, zt div mn, zt mod mn]); 
  //------------------------------------------------------------- 
  Mediaplayer.close; 
  Mediaplayer.free; 
end; 
 
// Beispielaufruf 
 
procedure TForm1.Button3Click(Sender: TObject); 
begin 
  screen.cursor := crHourglass; 
  Label1.caption := Dauer('c:\nicesong.mid', self); 
  screen.cursor := crDefault; 
end;