/*
   Copyright (C) 2003 Paul Brossier

   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., 675 Mass Ave, Cambridge, MA 02139, USA.

*/

#include "aubio_priv.h"
#include "fvec.h"
#include "cvec.h"
#include "mathutils.h"
#include "spectral/fft.h"

#if HAVE_FFTW3F
#define fftw_malloc            fftwf_malloc
#define fftw_free              fftwf_free
#define fftw_execute           fftwf_execute
#define fftw_plan_dft_r2c_1d   fftwf_plan_dft_r2c_1d
#define fftw_plan_dft_c2r_1d   fftwf_plan_dft_c2r_1d
#define fftw_plan_r2r_1d       fftwf_plan_r2r_1d
#define fftw_plan              fftwf_plan
#define fftw_destroy_plan      fftwf_destroy_plan
#endif

#if HAVE_FFTW3F
#if !AUBIO_SINGLE_PRECISION 
#warning "Using aubio in double precision with fftw3 in single precision"
#endif
#define real_t float 
#else
#define real_t double 
#endif

struct _aubio_fft_t {
  uint_t winsize;
  uint_t channels;
  uint_t fft_size;
  real_t *in, *out;
  fftw_plan pfw, pbw;
  fft_data_t * specdata;     /* complex spectral data */
  fvec_t * compspec;
};

aubio_fft_t * new_aubio_fft(uint_t winsize, uint_t channels) {
  aubio_fft_t * s = AUBIO_NEW(aubio_fft_t);
  s->winsize  = winsize;
  s->channels = channels;
  /* allocate memory */
  s->in       = AUBIO_ARRAY(real_t,winsize);
  s->out      = AUBIO_ARRAY(real_t,winsize);
  s->compspec = new_fvec(winsize,channels);
  /* create plans */
#ifdef HAVE_COMPLEX_H
  s->fft_size = winsize/2 + 1;
  s->specdata = (fft_data_t*)fftw_malloc(sizeof(fft_data_t)*s->fft_size);
  s->pfw = fftw_plan_dft_r2c_1d(winsize, s->in,  s->specdata, FFTW_ESTIMATE);
  s->pbw = fftw_plan_dft_c2r_1d(winsize, s->specdata, s->out, FFTW_ESTIMATE);
#else
  s->fft_size = winsize;
  s->specdata = (fft_data_t*)fftw_malloc(sizeof(fft_data_t)*s->fft_size);
  s->pfw = fftw_plan_r2r_1d(winsize, s->in,  s->specdata, FFTW_R2HC, FFTW_ESTIMATE);
  s->pbw = fftw_plan_r2r_1d(winsize, s->specdata, s->out, FFTW_HC2R, FFTW_ESTIMATE);
#endif
  return s;
}

void del_aubio_fft(aubio_fft_t * s) {
  /* destroy data */
  del_fvec(s->compspec);
  fftw_destroy_plan(s->pfw);
  fftw_destroy_plan(s->pbw);
  fftw_free(s->specdata);
  AUBIO_FREE(s->out);
  AUBIO_FREE(s->in );
  AUBIO_FREE(s);
}

void aubio_fft_do(aubio_fft_t * s, fvec_t * input, cvec_t * spectrum) {
  aubio_fft_do_complex(s, input, s->compspec);
  aubio_fft_get_spectrum(s->compspec, spectrum);
}

void aubio_fft_rdo(aubio_fft_t * s, cvec_t * spectrum, fvec_t * output) {
  aubio_fft_get_realimag(spectrum, s->compspec);
  aubio_fft_rdo_complex(s, s->compspec, output);
}

void aubio_fft_do_complex(aubio_fft_t * s, fvec_t * input, fvec_t * compspec) {
  uint_t i, j;
  for (i = 0; i < s->channels; i++) {
    for (j=0; j < s->winsize; j++) {
      s->in[j] = input->data[i][j];
    }
    fftw_execute(s->pfw);
#ifdef HAVE_COMPLEX_H
    compspec->data[i][0] = REAL(s->specdata[0]);
    for (j = 1; j < s->fft_size -1 ; j++) {
      compspec->data[i][j] = REAL(s->specdata[j]);
      compspec->data[i][compspec->length - j] = IMAG(s->specdata[j]);
    }
    compspec->data[i][s->fft_size-1] = REAL(s->specdata[s->fft_size-1]);
#else
    for (j = 0; j < s->fft_size; j++) {
      compspec->data[i][j] = s->specdata[j];
    }
#endif
  }
}

void aubio_fft_rdo_complex(aubio_fft_t * s, fvec_t * compspec, fvec_t * output) {
  uint_t i, j;
  const smpl_t renorm = 1./(smpl_t)s->winsize;
  for (i = 0; i < compspec->channels; i++) {
#ifdef HAVE_COMPLEX_H
    s->specdata[0] = compspec->data[i][0];
    for (j=1; j < s->fft_size - 1; j++) {
      s->specdata[j] = compspec->data[i][j] + 
        I * compspec->data[i][compspec->length - j];
    }
    s->specdata[s->fft_size - 1] = compspec->data[i][s->fft_size - 1];
#else
    for (j=0; j < s->fft_size; j++) {
      s->specdata[j] = compspec->data[i][j];
    }
#endif
    fftw_execute(s->pbw);
    for (j = 0; j < output->length; j++) {
      output->data[i][j] = s->out[j]*renorm;
    }
  }
}

void aubio_fft_get_spectrum(fvec_t * compspec, cvec_t * spectrum) {
  aubio_fft_get_phas(compspec, spectrum);
  aubio_fft_get_norm(compspec, spectrum);
}

void aubio_fft_get_realimag(cvec_t * spectrum, fvec_t * compspec) {
  aubio_fft_get_imag(spectrum, compspec);
  aubio_fft_get_real(spectrum, compspec);
}

void aubio_fft_get_phas(fvec_t * compspec, cvec_t * spectrum) {
  uint_t i, j;
  for (i = 0; i < spectrum->channels; i++) {
    spectrum->phas[i][0] = 0.;
    for (j=1; j < spectrum->length - 1; j++) {
      if (compspec->data[i][j] == 0.) spectrum->phas[i][j] = 0;
      else
      spectrum->phas[i][j] = atan2f(compspec->data[i][compspec->length-j],
          compspec->data[i][j]);
    }
    spectrum->phas[i][spectrum->length-1] = 0.;
  }
}

void aubio_fft_get_norm(fvec_t * compspec, cvec_t * spectrum) {
  uint_t i, j = 0;
  for (i = 0; i < spectrum->channels; i++) {
    spectrum->norm[i][0] = ABS(compspec->data[i][0]);
    for (j=1; j < spectrum->length - 1; j++) {
      spectrum->norm[i][j] = SQRT(SQR(compspec->data[i][j]) 
          + SQR(compspec->data[i][compspec->length - j]) );
    }
    spectrum->norm[i][spectrum->length-1] = 
      ABS(compspec->data[i][compspec->length/2]);
  }
}

void aubio_fft_get_imag(cvec_t * spectrum, fvec_t * compspec) {
  uint_t i, j;
  for (i = 0; i < compspec->channels; i++) {
    for (j = 1; j < compspec->length / 2 + 1; j++) {
      compspec->data[i][compspec->length - j] =
        spectrum->norm[i][j]*SIN(spectrum->phas[i][j]);
    }
  }
}

void aubio_fft_get_real(cvec_t * spectrum, fvec_t * compspec) {
  uint_t i, j;
  for (i = 0; i < compspec->channels; i++) {
    for (j = 0; j< compspec->length / 2 + 1; j++) {
      compspec->data[i][j] = 
        spectrum->norm[i][j]*COS(spectrum->phas[i][j]);
    }
  }
}