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 00020 #include "DownSampler.h" 00021 #include "../common_source.h" 00022 00023 using std::ostringstream; 00024 using namespace Marsyas; 00025 00026 00027 DownSampler::DownSampler(mrs_string name):MarSystem("DownSampler",name) 00028 { 00029 addControls(); 00030 } 00031 00032 DownSampler::~DownSampler() 00033 { 00034 } 00035 00036 DownSampler::DownSampler(const DownSampler& a) : MarSystem(a) 00037 { 00040 ctrl_factor_ = getControl("mrs_natural/factor"); 00041 } 00042 00043 MarSystem* 00044 DownSampler::clone() const 00045 { 00046 return new DownSampler(*this); 00047 } 00048 00049 void 00050 DownSampler::addControls() 00051 { 00052 addControl("mrs_natural/factor", 2, ctrl_factor_); 00053 ctrl_factor_->setState(true); 00054 } 00055 00056 void 00057 DownSampler::myUpdate(MarControlPtr sender) 00058 { 00059 MRSDIAG("DownSampler.cpp - DownSampler:myUpdate"); 00060 00061 // Use the default MarSystem setup with equal input/output stream format ... 00062 MarSystem::myUpdate(sender); 00063 00064 // ... but override the onSamples and osrate settings based on the 00065 // downsample factor. 00066 mrs_natural factor = ctrl_factor_->to<mrs_natural>(); 00067 ctrl_osrate_->setValue(ctrl_israte_->to<mrs_real>() / factor, NOUPDATE); 00068 // When inSamples is divisible by factor, the number of output samples 00069 // onSamples is just the integer division inSamples / factor. 00070 // Otherwise, onSamples is the biggest integer obeying 00071 // factor * (onSamples - 1) < inSamples 00072 // which is ceil(inSamples / factor). 00073 mrs_natural onSamples = (mrs_natural) ceil((mrs_real)(ctrl_inSamples_->to<mrs_natural>()) / factor); 00074 ctrl_onSamples_->setValue(onSamples, NOUPDATE); 00075 } 00076 00077 void 00078 DownSampler::myProcess(realvec& in, realvec& out) 00079 { 00080 mrs_natural t,o; 00081 mrs_natural factor = ctrl_factor_->to<mrs_natural>(); 00082 00083 // Only copy samples at multiples of factor. 00084 for (o=0; o < inObservations_; o++) 00085 { 00086 for (t = 0; t < onSamples_; t++) 00087 { 00088 out(o, t) = in(o, t * factor); 00089 } 00090 } 00091 }