view src/Support/ERBTools.h @ 10:d54efba7f09b

- Updated contact details and copyright lines to reflect actual copyright ownership
 (the University of Cambridge's intellectual property policy says that students own the
copyright on stuff they write unless there is a funding agreement saying otherwise)

// Copyright 2006-2010, Thomas Walters
//
// AIM-C: A C++ implementation of the Auditory Image Model
// http://www.acousticscale.org/AIMC
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

/*! \file
 *  \brief ERB calculations
 */

/*! \author: Thomas Walters <[e-mail]>
 *  \date 2010/01/23
 *  \version \$Id: ERBTools.h 1 2010-02-02 11:04:50Z tcw $
 */

#ifndef _AIMC_SUPPORT_ERBTOOLS_H_
#define _AIMC_SUPPORT_ERBTOOLS_H_

#include <math.h>

namespace aimc {
class ERBTools {
 public:
  static float Freq2ERB(float freq) {
    return 21.4f * log10(4.37f * freq / 1000.0f + 1.0f);
  }

  static float Freq2ERBw(float freq) {
    return 24.7f * (4.37f * freq / 1000.0f + 1.0f);
  }

  static float ERB2Freq(float erb) {
    return (pow(10, (erb / 21.4f)) - 1.0f) / 4.37f * 1000.0f;
  }
};
}

#endif  // _AIMC_SUPPORT_ERBTOOLS_H_