Get System Volume

uses MMSystem

//

procedure GetVolume(var volL, volR: Word);
var
  hWO: HWAVEOUT;
  waveF: TWAVEFORMATEX;
  vol: DWORD;
begin
  volL:= 0;
  volR:= 0;
  // init TWAVEFORMATEX
  FillChar(waveF, SizeOf(waveF), 0);
  // open WaveMapper = std output of playsound
  waveOutOpen(@hWO, WAVE_MAPPER, @waveF, 0, 0, 0);
  // get volume
  waveOutGetVolume(hWO, @vol);
  volL:= vol and $FFFF;
  volR:= vol shr 16;
  waveOutClose(hWO);
end;


procedure SetVolume(const volL, volR: Word);
var
  hWO: HWAVEOUT;
  waveF: TWAVEFORMATEX;
  vol: DWORD;
begin
  // init TWAVEFORMATEX
  FillChar(waveF, SizeOf(waveF), 0);
  // open WaveMapper = std output of playsound
  waveOutOpen(@hWO, WAVE_MAPPER, @waveF, 0, 0, 0);
  vol:= volL + volR shl 16;
  // set volume
  waveOutSetVolume(hWO, vol);
  waveOutClose(hWO);
end;

procedure TForm1.FormCreate(Sender: TObject);
var
  VolLi, VolRe: Word;
begin
  GetVolume(VolLi,VolRe);

  Label1.Caption := IntToStr(VolLi);
  Label2.Caption := IntToStr(VolRe);
end;