An Example C++ Program
Here is an example of what a program in the C++ language looks like.
This particular program loads a .WAV file
and then begins playing this song through the speakers. While the
song plays the left-channel and right-channel audio samples
are provided in real-time to the program.
Via a loop that executes every .1 seconds, we walk
through the latest batch of audio samples and determine
the peak amplitude. Ten times a second we then display the
detected peak volume on a stereo LED bar graph.
<![CDATA[
//////////////////////////////////////////////////////////////////////////////
// WinMain()
//
//////////////////////////////////////////////////////////////////////////////
int WINAPI WinMain( HINSTANCE hInstance, HINSTANCE hPrevInstance,
PSTR pszCmdLine, int iCmdShow )
{
// Ensure that the common control DLL is loaded.
InitCommonControls(); // InitCommonControlsEx() for the newer controls
// Create an instance of the cWinApp class. Every program
// that employs the CSL framework requires this object
// to provide infrastructure.
cWinApp theApp( hInstance, pszCmdLine, APPNAME );
// Instantiate an instance of whatever class provides your
// intended main window. The window will not be visible
// until you call the class's Create() member function.
cPeakDetectorDbg peak;
peak.Create();
char szSongTitle[] = "Its Only Money.wav";
peak.LoadSong( szSongTitle );
peak.printf( "Loaded %s\n", szSongTitle );
peak.printf( "click Play pushbutton\n" );
int iLeftChannelSamples[MAXNUMWAVESAMPLES];
int iRightChannelSamples[MAXNUMWAVESAMPLES];
UINT nSamples;
while ( theApp.PumpMessages() )
{
nSamples = peak.GetSamples( iLeftChannelSamples,
iRightChannelSamples,
MAXNUMWAVESAMPLES );
if ( nSamples > 0 )
{
UINT i;
int iMaxLeftSample = 0;
int iMaxRightSample = 0;
for ( i=0; i < nSamples; i++ )
{
if ( iLeftChannelSamples[i] > iMaxLeftSample )
iMaxLeftSample = iLeftChannelSamples[i];
if ( iRightChannelSamples[i] > iMaxRightSample )
iMaxRightSample = iRightChannelSamples[i];
}
peak.SetLevel( iMaxLeftSample, iMaxRightSample );
// write to the 2 channel LED bar graph
}
}
// Enter the message loop.
return theApp.Run();
// cWinApp::Run() does not return until a WM_QUIT message is received.
} // WinMain()
]]>
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