master volume control

Hi Stu,

Thanks for your answer but I was not able to make it work. I did some experienting and this is what I found.

AuxSetVolume(DeviceID, VolumeLevel)
AuxGetVolume(DeviceID, VolumeLevel)
I played with the get volume command. I assume except for what the functions do they both go to the same place. With the device id set to 5 i get an error code ~ MMSYSERR_BADDEVICEID

But device id 0 does controls the line device and id 1 controls the cd device. I tried other id's all gave me MMSYSERR_BADDEVICEID

I thought maybe I could gain control with with the wave and midi volume control. No help. Below is my souce code and the results.
I know it is possible to control the master volume from a program because the netscape media player does it. Let me know if u still want to work on it or not. If not I still give u some points for a good try.

Thanks
  Danny

unit Voltest;

interface

uses
  SysUtils, WinTypes, WinProcs, Messages, Classes, Graphics, Controls,
  Forms, Dialogs, mmsystem, StdCtrls;

type
  TForm1 = class(TForm)
    Label1: TLabel;
    Button1: TButton;
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;
  lVolume: Longint;

implementation

{$R *.DFM}

procedure TForm1.Button1Click(Sender: TObject);

var
  ccode: word;

begin
  {
  line in is $0
  the cd is $1
  ccode := auxGetVolume( $0, @lVolume ); }

  {
  the wave is $0
  ccode := waveOutGetVolume( $0, @lVolume );}

  {
   $1 controls returns $ffff as the volume, returns no error code. $ffff
      does not coraspond to anything.
   $0 returns and error 8 ~ mmsyserr_NotSupported
  ccode := midiOutGetVolume( $2, @lVolume ); }

  if ccode <> 0 then begin
    messagedlg( 'ccode is ' + intToStr( ccode ), mtinformation, [mbOk], 0 );
    if MMSYSERR_BADDEVICEID = ccode then
      messagedlg( 'ccode is MMSYSERR_BADDEVICEID', mtinformation, [mbOk], 0 );
    end;
  label1.caption := intToHex( lVolume, 4 )
end;

end.

Hi Dan,

I'll have a go at it shortly.  However, one thing I must mention is that some sound cards do not work with any of these API calls.  It depends on the sound card.  I have no explaination as to why, but its a sad fact.  We develop multi-media educational products, and when SoundBlaster cards where the norm, we had no problems adjusting the mixer settings.  Now with all these cheap second rate sound cards, we have stopped doing it (we actually launch Windows mixer!).

As I said, I'll see if i can figure something out for you.  I'll let you know either way.

Stu