Voice Recording/Saving in Delphi

Question

Is there a component or code that allows the following: Record a spoken word (or words) and save it/them to a file that can be played back. The file must be able to be played back on XP, Vista and Windows 7. The file can be either stand alone or saved to a datasource.

[Using Delphi 7 for creating apps on XP and using Absolute Database.]

Answer 1

The functions in MMSystem.pas let you do this using Windows API. You can either use high-level functions such as the MCI functions and PlaySound, or low-level functions such as waveInOpen, waveInPrepareHeader, waveInProc etc.

If you want high control, you really should use the low-level functions. Except for PlaySound, I have never used the high-level MCI interface.

MCI

This is working code:

procedure TForm1.FormCreate(Sender: TObject);
var
  op: TMCI_Open_Parms;
  rp: TMCI_Record_Parms;
  sp: TMCI_SaveParms;
begin

  // Open
  op.lpstrDeviceType := 'waveaudio';
  op.lpstrElementName := '';
  if mciSendCommand(0, MCI_OPEN, MCI_OPEN_ELEMENT or MCI_OPEN_TYPE, cardinal(@op)) <> 0 then
    raise Exception.Create('MCI error');

  try

    // Record
    rp.dwFrom := 0;
    rp.dwTo := 5000; // 5000 ms = 5 sec
    rp.dwCallback := 0;
    if mciSendCommand(op.wDeviceID, MCI_RECORD, MCI_TO or MCI_WAIT, cardinal(@rp)) <> 0 then
      raise Exception.Create('MCI error. No microphone connected to the computer?');

    // Save
    sp.lpfilename := PChar(ExtractFilePath(Application.ExeName) + 'test.wav');
    if mciSendCommand(op.wDeviceID, MCI_SAVE, MCI_SAVE_FILE or MCI_WAIT, cardinal(@sp)) <> 0 then
      raise Exception.Create('MCI error');

  finally
    mciSendCommand(op.wDeviceID, MCI_CLOSE, 0, 0);
  end;

end;