src/time_frequency.h

Go to the documentation of this file.

/***************************************************************************
 *   Copyright (C) 2008 by Matthias Ihrke   *
 *   mihrke@uni-goettingen.de   *
 *                                                                         *
 *   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 2 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, write to the                         *
 *   Free Software Foundation, Inc.,                                       *
 *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
 ***************************************************************************/
#ifndef TIME_FREQUENCY_H
# define TIME_FREQUENCY_H

#include "definitions.h"
#include "complex.h"
#include "array.h"
#include "optarg.h"
#include <math.h>

#ifdef __cplusplus
extern "C" {
#endif

  typedef Array* (*WindowFunction)(int,double);

  typedef struct {
    int            N_freq;       
    int            N_time;  
     double         samplingrate; 
     double         low_corner_freq; 
     double         up_corner_freq; 
     Complex        **sgram; 
  } Spectrogram;
  
  Spectrogram* spectrogram_stft(const Array* sig, double sampling_rate,
                                          const Array *Window, int N_freq, int N_time, 
                                          double corner_freqs[2], 
                                          int *timepoints, Spectrogram *spectgram);
  Spectrogram* spectrogram( const Array *sig, Spectrogram *spectgram, 
                                     OptArgList *optargs );
  Array* spectrogram_powerspectrum( const Spectrogram *spect );

  Spectrogram* spectrogram_init( int N_freq, int N_time );
  void         spectrogram_free( Spectrogram *s );


  /*------------------- window functions --------------- */
  Array* window_dirichlet( int n, double noparam );
  Array* window_gaussian ( int n, double sigma );
  Array* window_hamming  ( int n, double noparam );
  Array* window_hanning  ( int n, double noparam );
  Array* window_kaiser   ( int n, double alpha );

#ifdef __cplusplus
}
#endif



#endif /* TIME_FREQUENCY_H */