File:Harmonic additive synthesis.ogg

Harmonic_additive_synthesis.ogg(Ogg Vorbis sound file, length 10 s, 155 kbps, file size: 189 KB)

Summary

Description
English: A sound created by harmonic additive synthesis. Generated by the following C++ source code (compiled with GNU g++ version 4.5.2 with libsndfile 1.0.23.)
#include <sndfile.h>
#include <cmath>
#include <algorithm>
using namespace std;
const double twopi=8*atan(1);
double Amplitude(int k, double t)
{
double mint=max(4-t,0.0)*max(4-t,0.0);
double sweepamount=0.5*(tanh(t-5)+1);
double amp=0.19*exp(-(mint*0.15+0.1)*(k-1));
amp*=sweepamount*sin(0.25*k-2*t)*sin(0.25*k-2*t)+(1-sweepamount);
if (!(k%2)) amp*=0.5*(tanh(7-t)+1);
return amp;
}
int main()
{
double sr=44100;
int nFrames=int(sr)*10;
double *buf = new double[nFrames];
double t=0, dt=1.0/sr;
double f0=440.0;
int K=44;
for (int n=0; n<nFrames; n++)
{
buf[n]=0;
for (int k=1; k<K; k++) buf[n]+=Amplitude(k,t)*sin(t*twopi*f0*k);
t+=dt;
}
SF_INFO sfinfo;
sfinfo.samplerate=sr;
sfinfo.channels=1;
sfinfo.format=SF_FORMAT_WAV|SF_FORMAT_PCM_16;
SNDFILE *out = sf_open("out.wav", SFM_WRITE, &sfinfo);
sf_writef_double(out, buf, nFrames);
sf_close(out);
delete [] buf;
return 0;
}
Date
Source Own work (Original text: Self-made)
Author Chrisjohnson (talk)
Permission
(Reusing this file)
Creative Commons Attribution-ShareAlike

Licensing

Chrisjohnson at English Wikipedia, the copyright holder of this work, hereby publishes it under the following license:
w:en:Creative Commons
attribution share alike
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Transferred from en.wikipedia to Commons by FSII using CommonsHelper.

The original description page was here. All following user names refer to en.wikipedia.
  • 2012-01-14 23:32 Chrisjohnson 0×0× (193179 bytes) {{Information |Description = A sound created by harmonic additive synthesis |Source = Self-made |Date = 2012-01-14 |Author = ~~~ |Permission = Creative Commons Attribution-ShareAlike }}

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14 January 2012

application/ogg

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Date/TimeThumbnailDimensionsUserComment
current11:48, 9 February 201210 s (189 KB)Upload Bot (Rich Smith) {{BotMoveToCommons|en.wikipedia|year={{subst:CURRENTYEAR}}|month={{subst:CURRENTMONTHNAME}}|day={{subst:CURRENTDAY}}}} {{Information |Description={{en|A sound created by harmonic additive synthesis. Generated by the following C++ source code (compiled wi
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