type 
 EMyMCIException = class(Exception); 

var 
 FDeviceID: Word; 
 MyError, dwFlags: Longint; 

procedure TForm1.GetWaveLength; 
var 
 WaveLen: DWORD; 
begin 
 OpenMedia('C:\Hickory.wav'); 
 SetMediaTimeFormat; 
 WaveLen := GetMediaStatus(MCI_STATUS_LENGTH); 
 CloseMedia; 
 Form1.label1.Caption := IntToStr(WaveLen) + 'mS'; 
end; 

procedure TForm1.OpenMedia(FileName: string); 
var 
 MyOpenParms: TMCI_Open_Parms; 
begin 
 with MyOpenParms do 
 begin 
 dwCallback := Handle; // TForm1.Handle 
 lpstrDeviceType := PChar('WaveAudio'); 
 lpstrElementName := PChar(FileName); 
 end; {with MyOpenParms} 
 dwFlags := MCI_WAIT or MCI_OPEN_ELEMENT or MCI_OPEN_TYPE; 
 MyError := mciSendCommand(0, MCI_OPEN, dwFlags, Longint(@MyOpenParms)); 
 // one could use mciSendCommand(DevId, etc here to specify a particular 
 device 
 if MyError = 0 then 
 FDeviceID := MyOpenParms.wDeviceID 
 else 
 raise EMyMCIException.Create('Open Failed'); 
end; 

procedure TForm1.SetMediaTimeFormat; 
var 
 MySetParms: TMCI_Set_Parms; 
begin 
 if FDeviceID <> 0 then 
 begin 
 dwFlags := MCI_WAIT or MCI_SET_TIME_FORMAT; 
 MySetParms.dwCallback := Handle; // TForm1.Handle 
 MySetParms.dwTimeFormat := MCI_FORMAT_MILLISECONDS; 
 MyError := mciSendCommand(FDeviceID, MCI_SET, dwFlags, 
 Longint(@MySetParms)); 
 if MyError <> 0 then 
 raise EMyMCIException.Create('Status Failed'); 
 end; 
end; 

function TForm1.GetMediaStatus(StatusItem: DWORD): DWORD; 
var 
 MyStatusParms: TMCI_Status_Parms; 
begin 
 if FDeviceID <> 0 then 
 begin 
 dwFlags := MCI_WAIT or MCI_STATUS_ITEM; 
 MyStatusParms.dwCallback := Handle; // TForm1.Handle 
 MyStatusParms.dwItem := StatusItem; 
 MyError := mciSendCommand(FDeviceID, MCI_STATUS, dwFlags, 
 Longint(@MyStatusParms)); 
 if MyError = 0 then 
 Result := MyStatusParms.dwReturn 
 else 
 begin 
 raise EMyMCIException.Create('Status Failed'); 
 end; 
 end; 
end; 

procedure TForm1.CloseMedia; 
var 
 MyGenParms: TMCI_Generic_Parms; 
begin 
 if FDeviceID <> 0 then 
 begin 
 dwFlags := 0; 
 MyGenParms.dwCallback := Handle; // TForm1.Handle 
 MyError := mciSendCommand(FDeviceID, MCI_CLOSE, dwFlags, 
 Longint(@MyGenParms)); 
 if MyError = 0 then 
 FDeviceID := 0 
 else 
 begin 
 raise EMyMCIException.Create('Close Failed'); 
 end; 
 end; 
end;