Re: Beep(freq,dur) MIDI-style

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#16248

From: Ted Lyngmo
Date: Fri, 23 May 2003 02:18

31 lines
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Chris Hill wrote:
 >
 > DWORD FreqToNote(DWORD frequency)
 > {
 > 	double freq;
 > 	int x;
 >
 > 	for(x = 0; x < 127; x++)
 > 	{
 > 		freq = (440.0 / 32) * pow(2,((x - 9) / 12));
 > 		if (freq > frequency)
 > 			break;
 > 	}
 > 	
 > 	return x;
 > }

An alternative way of doing the frequency to midi note conversion:

int FreqToNote(double frequency) {
     static const double base=55.0*pow(2.0,-33.0/12.0); // C0

     return (int) (log(frequency/base)/(log(2.0)/12.0)+.5);
}

Kind regards,
Ted Lyngmo

-- 
Replace MY_FIRST_NAME in my email address with my first name to send a private
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