ian@0: //  Copyright 2011, Ian Hobson.
ian@0: //
ian@0: //  This file is part of gpsynth.
ian@0: //
ian@0: //  gpsynth is free software: you can redistribute it and/or modify
ian@0: //  it under the terms of the GNU General Public License as published by
ian@0: //  the Free Software Foundation, either version 3 of the License, or
ian@0: //  (at your option) any later version.
ian@0: //
ian@0: //  gpsynth is distributed in the hope that it will be useful,
ian@0: //  but WITHOUT ANY WARRANTY; without even the implied warranty of
ian@0: //  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
ian@0: //  GNU General Public License for more details.
ian@0: //
ian@0: //  You should have received a copy of the GNU General Public License
ian@0: //  along with gpsynth in the file COPYING. 
ian@0: //  If not, see http://www.gnu.org/licenses/.
ian@0: 
ian@0: // Wrapper classes for FFTW
ian@0: 
ian@0: #pragma once
ian@0: 
ian@0: #include "fftw3.h"
ian@0: 
ian@0: #include <complex>
ian@0: 
ian@0: namespace dsp {
ian@0: 
ian@0: // Float version
ian@0: class SpectrumAnalyzerFloat {
ian@0:   fftwf_plan plan_;
ian@0:   int frame_size_;
ian@0:   float* input_;
ian@0:   std::complex<float>* output_;
ian@0: 
ian@0: public:
ian@0:   SpectrumAnalyzerFloat(int frame_size = 1024)
ian@0:   : frame_size_(frame_size)
ian@0:   {
ian@0:     input_ = (float*)fftw_malloc(sizeof(float) * frame_size);
ian@0:     int buffer_size = sizeof(std::complex<float>) * frame_size / 2;
ian@0:     output_ = (std::complex<float>*)fftw_malloc(buffer_size);
ian@0:     plan_ = fftwf_plan_dft_r2c_1d(frame_size,
ian@0:                                   input_,
ian@0:                                   reinterpret_cast<fftwf_complex*>(output_),
ian@0:                                   FFTW_ESTIMATE);
ian@0:   }
ian@0:   
ian@0:   SpectrumAnalyzerFloat() {
ian@0:     fftw_free(input_);
ian@0:     fftw_free(output_);
ian@0:     fftwf_destroy_plan(plan_);
ian@0:   }
ian@0:   
ian@0:   void Execute() {
ian@0:     fftwf_execute(plan_);
ian@0:   }
ian@0:   
ian@0:   int Size() { return frame_size_; }
ian@0:   float* Input() { return input_; }
ian@0:   std::complex<float>* Output() { return output_; }
ian@0: };
ian@0:   
ian@0: // Double version
ian@0: class SpectrumAnalyzer {
ian@0:   fftw_plan plan_;
ian@0:   int frame_size_;
ian@0:   double* input_;
ian@0:   std::complex<double>* output_;
ian@0:   
ian@0: public:
ian@0:   SpectrumAnalyzer(int frame_size = 1024)
ian@0:   : frame_size_(frame_size)
ian@0:   {
ian@0:     input_ = (double*)fftw_malloc(sizeof(double) * frame_size);
ian@0:     int buffer_size = sizeof(std::complex<double>) * frame_size;
ian@0:     output_ = (std::complex<double>*)fftw_malloc(buffer_size);
ian@0:     plan_ = fftw_plan_dft_r2c_1d(frame_size,
ian@0:                                  input_,
ian@0:                                  reinterpret_cast<fftw_complex*>(output_),
ian@0:                                  FFTW_ESTIMATE);
ian@0:   }
ian@0:   
ian@0:   SpectrumAnalyzer() {
ian@0:     fftw_free(input_);
ian@0:     fftw_free(output_);
ian@0:     fftw_destroy_plan(plan_);
ian@0:   }
ian@0:   
ian@0:   void Execute() {
ian@0:     fftw_execute(plan_);
ian@0:   }
ian@0:   
ian@0:   int Size() { return frame_size_; }
ian@0:   double* Input() { return input_; }
ian@0:   std::complex<double>* Output() { return output_; }
ian@0: };
ian@0: 
ian@0: } // dsp namespace