CLAM-Development  1.4.0
SpectralExciter.cxx
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1 /*
2  * Copyright (c) 2001-2004 MUSIC TECHNOLOGY GROUP (MTG)
3  * UNIVERSITAT POMPEU FABRA
4  *
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, write to the Free Software
18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19  *
20  */
21 
22 #include "SpectralExciter.hxx"
23 #include "ProcessingFactory.hxx"
24 
25 namespace CLAM
26 {
27 namespace Hidden
28 {
29  static const char * metadata[] = {
30  "key", "SpectralExciter",
31  // "category", "Spectral Transformations",
32  // "description", "SpectralExciter",
33  0
34  };
35  static FactoryRegistrator<ProcessingFactory, SpectralExciter> reg = metadata;
36 }
37 
38 
39 bool SpectralExciter::Do(const Spectrum& in, Spectrum& out)
40 {
41  out = in; //we are better off copying it no matter whether out has to be preserved or not.
42 
43 
44  int spectrumSize = in.GetSize();
45  TData spectralResolution = spectrumSize/in.GetSpectralRange();
46 
47  int highCutoff = Round(mHighCutoffFreqCtl.GetLastValue()* spectralResolution);
48 
49  TData threshold = log2lin(mThresholdCtl.GetLastValue());
50  TData gain = log2lin(mHarmonicsGainCtl.GetLastValue());
51 
52  DataArray& outMag = out.GetMagBuffer();
53 
54  int i,n;
55 
56  //note: we might want to do something to the phase
57  for(i = spectrumSize; i>highCutoff; i--)
58  {
59  if(outMag[i]>threshold)
60  {
61  for (n=i*2; n<spectrumSize; n+=i) {
62  outMag[n] += outMag[i]*gain;
63  if (outMag[n]>1.) {
64  outMag[n]=1.;
65  }
66  }
67  }
68  }
69  return true;
70 }
71 
72 
73 }
74