CLAM-Development  1.4.0
SpectralCombTriang.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 "SpectralCombTriang.hxx"
23 #include "ProcessingFactory.hxx"
24 
25 namespace CLAM
26 {
27 
28 namespace Hidden
29 {
30  static const char * metadata[] = {
31  "key", "SpectralCombTriang",
32  // "category", "Spectral Transformations",
33  // "description", "SpectralCombTriang",
34  0
35  };
36  static FactoryRegistrator<ProcessingFactory, SpectralCombTriang> reg = metadata;
37 }
38 
39 
41 {
42  if (!mConfig.GetPreserveOuts())
43  {
44  out = in; //TODO big cludge for streaming
45  }
46  DataArray& inMag = in.GetMagBuffer();
47  DataArray& outMag = out.GetMagBuffer();
48 
49  int spectrumSize = in.GetSize();
50 
51  TData spectralResolution = spectrumSize/in.GetSpectralRange();
52  int fundamental = Round(mFundamentalCtl.GetLastValue()* spectralResolution);
53 
54  int i;
55  int n;
56  n = 0;
57  int bandlimit = fundamental;
58  //control expected in dB
59  TData overallGain = log2lin(mAmount.GetLastValue());
60  for(i = 0; i<spectrumSize; i++)
61  {
62  if(i > bandlimit)
63  {
64  n++;
65  bandlimit = fundamental * n;
66  }
67  outMag[i] = inMag[i]*GetGain(fundamental, i, n)*overallGain;
68  }
69  return true;
70 }
71 
72 TData SpectralCombTriang::GetGain(int fundamental, int binPos, int bandNum)
73 {
74  //first we find whether the binPos is on a positive or negative slope part
75  //auxiliary data
76  TData period = fundamental;
77 
78  //compute mid point
79  int midPoint = int (period * 0.5);
80 
81  bool ascending = false;
82  if ((binPos - fundamental*bandNum)> midPoint || bandNum == 0) ascending = true;
83 
84 
85  //compute linear equation y = ax + b
86  //first the 'a'
87  TData a = 2/fundamental;
88  if (!ascending) a = -a;
89  //now the 'b'
90  TData b = 1;
91  if(ascending) b = 0;
92  //now the x
93  int x;
94  if (bandNum==0) x = binPos;
95  else if(ascending) x = binPos - int(fundamental*bandNum + midPoint);
96  else x = binPos - int(fundamental * bandNum);
97 
98  //ready to compute the gain
99  return a*x + b;
100 }
101 
102 
103 }
104