Marsyas
0.6.0-alpha
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00001 /* 00002 ** Copyright (C) 1998-2006 George Tzanetakis <gtzan@cs.uvic.ca> 00003 ** 00004 ** This program is free software; you can redistribute it and/or modify 00005 ** it under the terms of the GNU General Public License as published by 00006 ** the Free Software Foundation; either version 2 of the License, or 00007 ** (at your option) any later version. 00008 ** 00009 ** This program is distributed in the hope that it will be useful, 00010 ** but WITHOUT ANY WARRANTY; without even the implied warranty of 00011 ** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 00012 ** GNU General Public License for more details. 00013 ** 00014 ** You should have received a copy of the GNU General Public License 00015 ** along with this program; if not, write to the Free Software 00016 ** Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. 00017 */ 00018 00019 #include "Limiter.h" 00020 #include "../common_source.h" 00021 00022 using std::ostringstream; 00023 using namespace Marsyas; 00024 00025 Limiter::Limiter(mrs_string name):MarSystem("Limiter",name) 00026 { 00027 //type_ = "Limiter"; 00028 //name_ = name; 00029 00030 xdprev_ = 0.0; 00031 alpha_ = 0.0; 00032 00033 addControls(); 00034 } 00035 00036 00037 Limiter::~Limiter() 00038 { 00039 } 00040 00041 00042 MarSystem* 00043 Limiter::clone() const 00044 { 00045 return new Limiter(*this); 00046 } 00047 00048 void 00049 Limiter::addControls() 00050 { 00051 addctrl("mrs_real/thresh", 1.0); 00052 addctrl("mrs_real/at", 0.0001); 00053 addctrl("mrs_real/rt", 0.130); 00054 addctrl("mrs_real/slope", 1.0); 00055 } 00056 00057 00058 void 00059 Limiter::myUpdate(MarControlPtr sender) 00060 { 00061 MRSDIAG("Limiter.cpp - Limiter:myUpdate"); 00062 00063 // setctrl("mrs_natural/onSamples", getctrl("mrs_natural/inSamples")); 00064 // setctrl("mrs_natural/onObservations", getctrl("mrs_natural/inObservations")); 00065 // setctrl("mrs_real/osrate", getctrl("mrs_real/israte")); 00066 // setctrl("mrs_string/onObsNames", getctrl("mrs_string/inObsNames")); 00067 MarSystem::myUpdate(sender); //default myUpdate as defined at parent MarSystem class... 00068 00069 //defaultUpdate(); [!] 00070 inSamples_ = getctrl("mrs_natural/inSamples")->to<mrs_natural>(); 00071 00072 xd_.create(inSamples_); 00073 gains_.create(inSamples_); 00074 } 00075 00076 00077 void 00078 Limiter::myProcess(realvec& in, realvec& out) 00079 { 00080 //checkFlow(in,out); 00081 mrs_natural o,t; 00082 mrs_real thresh = getctrl("mrs_real/thresh")->to<mrs_real>(); 00083 mrs_real at = getctrl("mrs_real/at")->to<mrs_real>(); 00084 mrs_real rt = getctrl("mrs_real/rt")->to<mrs_real>(); 00085 mrs_real slope = getctrl("mrs_real/slope")->to<mrs_real>(); 00086 00087 // calculate at and rt time 00088 at = 1 - exp(-2.2/(22050*at)); 00089 rt = 1 - exp(-2.2/(22050*rt)); 00090 00091 for (o = 0; o < inObservations_; o++) 00092 { 00093 for (t = 0; t < inSamples_; t++) 00094 { 00095 // Calculates the current amplitude of signal and incorporates 00096 // the at and rt times into xd(o,t) 00097 alpha_ = fabs(in(o,t)) - xdprev_; 00098 00099 if (alpha_<0) 00100 { 00101 alpha_ = 0; 00102 } 00103 00104 xd_(o,t)=xdprev_*(1-rt)+at*alpha_; 00105 xdprev_ = xd_(o,t); 00106 00107 // Limiter 00108 if (xd_(o,t) > thresh) 00109 { 00110 gains_(o,t) = pow((mrs_real)10.0,-slope*(log10(xd_(o,t))-log10(thresh))); 00111 // linear calculation of gains_ = 10^(-Limiter Slope * (current value - Limiter Threshold)) 00112 } 00113 else 00114 { 00115 gains_(o,t) = 1; 00116 } 00117 00118 out(o,t) = gains_(o,t) * in(o,t); 00119 } 00120 } 00121 }