[Setup]
AppName=My Program & Bass Audio Project :-)
AppVersion=1.5
DefaultDirName={pf}\My Program
WizardImageFile=WelcomeImage.bmp

[Files]
Source: "Bass.dll"; Flags: dontcopy
Source: "AudioFile.mp3"; Flags: dontcopy
Source: "FinalImage.bmp"; Flags: dontcopy

[Code]
const
  BASS_SAMPLE_LOOP = 4;
  BASS_UNICODE = $80000000;
  BASS_CONFIG_GVOL_STREAM = 5;
  #ifndef UNICODE
    EncodingFlag = 0;
  #else
    EncodingFlag = BASS_UNICODE;
  #endif

type
  HSTREAM = DWORD;

function BASS_Init(device: LongInt; freq, flags: DWORD;
  win: HWND; clsid: Cardinal): BOOL;
  external 'BASS_Init@files:bass.dll stdcall';
function BASS_StreamCreateFile(mem: BOOL; f: string; offset1: DWORD;
  offset2: DWORD; length1: DWORD; length2: DWORD; flags: DWORD): HSTREAM;
  external 'BASS_StreamCreateFile@files:bass.dll stdcall';
function BASS_ChannelPlay(handle: DWORD; restart: BOOL): BOOL;
  external 'BASS_ChannelPlay@files:bass.dll stdcall';
function BASS_SetConfig(option: DWORD; value: DWORD ): BOOL;
  external 'BASS_SetConfig@files:bass.dll stdcall';
function BASS_Free: BOOL;
  external 'BASS_Free@files:bass.dll stdcall';

procedure InitializeWizard;
var
  StreamHandle: HSTREAM;
begin
  // extract the file from the [Files] section to the temporary folder
  ExtractTemporaryFile('FinalImage.bmp');
  // and load the just extracted bitmap to the image on the final page
  WizardForm.WizardBitmapImage2.Bitmap.LoadFromFile(ExpandConstant('{tmp}\FinalImage.bmp'));

  ExtractTemporaryFile('AudioFile.mp3');
  if BASS_Init(-1, 44100, 0, 0, 0) then
  begin
    StreamHandle := BASS_StreamCreateFile(False,
      ExpandConstant('{tmp}\AudioFile.mp3'), 0, 0, 0, 0,
      EncodingFlag or BASS_SAMPLE_LOOP);
    BASS_SetConfig(BASS_CONFIG_GVOL_STREAM, 2500);
    BASS_ChannelPlay(StreamHandle, False);
  end;
end;

procedure DeinitializeSetup;
begin
  BASS_Free;
end;