CLAM-Development  1.4.0
SpectralNotch.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 "SpectralNotch.hxx"
23 #include "ProcessingFactory.hxx"
24 
25 namespace CLAM
26 {
27 
28 namespace Hidden
29 {
30  static const char * metadata[] = {
31  "key", "SpectralNotch",
32  // "category", "Spectral Transformations",
33  // "description", "SpectralNotch",
34  0
35  };
36  static FactoryRegistrator<ProcessingFactory, SpectralNotch> reg = metadata;
37 }
38 
39 bool SpectralNotch::Do(const Spectrum& in, Spectrum& out)
40 {
41  out = in; //we need to copy input to output no matter what
42 
43  DataArray& outMag = out.GetMagBuffer();
44 
45  int spectrumSize = in.GetSize();
46 
47  TData spectralResolution = spectrumSize/in.GetSpectralRange();
48  int centerFreq = Round(mFreq.GetLastValue()*spectralResolution);
49  int band = Round(mBandwidthCtl.GetLastValue()*spectralResolution);
50  TData gain = log2lin(mGainCtl.GetLastValue());
51  int n;
52  int harmonic = 1;
53  int leftLimit = centerFreq-band;
54  if(leftLimit<0) leftLimit = 0;
55  int rightLimit = centerFreq+band+1;
56  if(rightLimit>spectrumSize) rightLimit=spectrumSize;
57  for (n=leftLimit; n<rightLimit;n++)
58  {
59  outMag[n] *= gain ;
60  }
61  //implement small rolloff to avoid Gibbs effect
62  outMag[leftLimit-1] *= (gain*0.5);
63  outMag[rightLimit] *= (gain*0.5);
64  return true;
65 }
66 
67 
68 }
69