Marsyas  0.5.0-beta1
/Users/jleben/code/marsyas/src/marsyas/ERBTools.h
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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 #ifndef MARSYAS_ERBTOOLS_H
00020 #define MARSYAS_ERBTOOLS_H
00021 
00022 namespace Marsyas
00023 {
00024 
00025 //
00026 // From ERBTools.h in AIMC
00027 //
00028 class ERBTools {
00029 public:
00030   static double Freq2ERB(double freq) {
00031     return 21.4 * log10(4.37 * freq / 1000.0 + 1.0);
00032   }
00033 
00034   static double Freq2ERBw(double freq) {
00035     return 24.7 * (4.37 * freq / 1000.0 + 1.0);
00036   }
00037 
00038   static double ERB2Freq(double erb) {
00039     return (pow(10, (erb / 21.4)) - 1.0) / 4.37 * 1000.0;
00040   }
00041 };
00042 }
00043 #endif