Author: Tomas Rutkauskas

How can I change the volume?

Answer:

1   procedure SetVolume(X: Word);
2   var
3     iErr: Integer;
4     i: integer;
5     a: TAuxCaps;
6   begin
7     for i := 0 to auxGetNumDevs do
8     begin
9       auxGetDevCaps(i, Addr(a), SizeOf(a));
10      if a.wTechnology = AUXCAPS_CDAUDIO then
11        break;
12    end;
13  
14    // Sets volume equally for left and right channels.
15    // VOLUME := LEFT * $10000 + RIGHT * 1 (or the other way? :)
16  
17    iErr := auxSetVolume(i, (X * $10001));
18    if (iErr = 0) then
19      ShowMessage('No audio devices are available!');
20  end;
21  
22  function GetVolume: Word;
23  var
24    iErr: Integer;
25    i: integer;
26    a: TAuxCaps;
27    vol: word;
28  begin
29    for i := 0 to auxGetNumDevs do
30    begin
31      auxGetDevCaps(i, Addr(a), SizeOf(a));
32      if a.wTechnology = AUXCAPS_CDAUDIO then
33        break;
34    end;
35    iErr := auxGetVolume(i, addr(vol));
36    GetVolume := vol;
37    if (iErr = 0) then
38      ShowMessage('No audio devices are available!');
39  end;


You'll have to modify AUXCAPS_CDAUDIO to whatever suits
(check out available values via the Ctrl+Space shortcut in Delphi 3)