Changeset b276dee for src/filterbank.c

Timestamp:

Sep 8, 2007, 3:59:11 PM (17 years ago)

Author:

Paul Brossier <piem@piem.org>

Branches:

feature/autosink, feature/cnn, feature/cnn_org, feature/constantq, feature/crepe, feature/crepe_org, feature/pitchshift, feature/pydocstrings, feature/timestretch, fix/ffmpeg5, master, pitchshift, sampler, timestretch, yinfft+

Children:

f14a78d

Parents:

53a7576

Message:

mfcc.{c,h}, filterbank.{c,h}: move filter initialisation into new_aubio_filterbank_mfcc

File:

• src/filterbank.c (modified) (4 diffs)

src/filterbank.c

@@ -24 +24 @@
 
 #include "aubio_priv.h"
+#include "sample.h"
 #include "filterbank.h"
+
+#define USE_EQUAL_GAIN 1
+#define VERY_SMALL_NUMBER 2e-42
 
 /** \brief A structure to store a set of n_filters filters of lenghts win_s */
@@ -30 +34 @@
     uint_t win_s;
     uint_t n_filters;
-    fvec_t *filters;
+    fvec_t **filters;
 };
 
@@ -41 +45 @@
 
   /** allocating filter tables */
-  fb->filters=AUBIO_ARRAY(n_filters,fvec_t);
+  fb->filters=AUBIO_ARRAY(fvec_t*,n_filters);
   for (filter_cnt=0; filter_cnt<n_filters; filter_cnt++)
     /* considering one-channel filters */
-    filters[filter_cnt]=new_fvec(win_s, 1);
+    fb->filters[filter_cnt]=new_fvec(win_s, 1);
+
+  return fb;
+}
+
+aubio_filterbank_t * new_aubio_filterbank_mfcc(uint_t n_filters, uint_t win_s, smpl_t samplerate, smpl_t freq_min, smpl_t freq_max){
+  smpl_t nyquist = samplerate/2.;
+  uint_t style = 1;
+  aubio_filterbank_t * fb = new_aubio_filterbank(n_filters, win_s);
+
+  uint_t n, i, k, *fft_peak, M, next_peak; 
+  smpl_t norm, mel_freq_max, mel_freq_min, norm_fact, height, inc, val, 
+         freq_bw_mel, *mel_peak, *height_norm, *lin_peak;
+
+  mel_peak = height_norm = lin_peak = NULL;
+  fft_peak = NULL;
+  norm = 1; 
+
+  mel_freq_max = 1127 * log(1 + freq_max / 700);
+  mel_freq_min = 1127 * log(1 + freq_min / 700);
+  freq_bw_mel = (mel_freq_max - mel_freq_min) / fb->n_filters;
+
+  mel_peak = (smpl_t *)malloc((fb->n_filters + 2) * sizeof(smpl_t)); 
+  /* +2 for zeros at start and end */
+  lin_peak = (smpl_t *)malloc((fb->n_filters + 2) * sizeof(smpl_t));
+  fft_peak = (uint_t *)malloc((fb->n_filters + 2) * sizeof(uint_t));
+  height_norm = (smpl_t *)malloc(fb->n_filters * sizeof(smpl_t));
+
+  if(mel_peak == NULL || height_norm == NULL || 
+      lin_peak == NULL || fft_peak == NULL)
+    return NULL;
+
+  M = fb->win_s >> 1;
+
+  mel_peak[0] = mel_freq_min;
+  lin_peak[0] = 700 * (exp(mel_peak[0] / 1127) - 1);
+  fft_peak[0] = lin_peak[0] / nyquist * M;
+
+
+  for (n = 1; n <= fb->n_filters; n++){  
+    /*roll out peak locations - mel, linear and linear on fft window scale */
+    mel_peak[n] = mel_peak[n - 1] + freq_bw_mel;
+    lin_peak[n] = 700 * (exp(mel_peak[n] / 1127) -1);
+    fft_peak[n] = lin_peak[n] / nyquist * M;
+  }
+
+  for (n = 0; n < fb->n_filters; n++){
+    /*roll out normalised gain of each peak*/
+    if (style == USE_EQUAL_GAIN){
+      height = 1; 
+      norm_fact = norm;
+    }
+    else{
+      height = 2 / (lin_peak[n + 2] - lin_peak[n]);
+      norm_fact = norm / (2 / (lin_peak[2] - lin_peak[0]));
+    }
+    height_norm[n] = height * norm_fact;
+  }
+
+  i = 0;
+
+  for(n = 0; n < fb->n_filters; n++){
+
+    /*calculate the rise increment*/
+    if(n > 0)
+      inc = height_norm[n] / (fft_peak[n] - fft_peak[n - 1]);
+    else
+      inc = height_norm[n] / fft_peak[n];
+    val = 0;  
+
+    /*zero the start of the array*/
+    for(k = 0; k < i; k++)
+      //fft_tables[n][k] = 0.f;
+      fb->filters[n]->data[0][k]=0.f;
+
+    /*fill in the rise */
+    for(; i <= fft_peak[n]; i++){ 
+      // fft_tables[n][i] = val;
+      fb->filters[n]->data[0][k]=val;
+      val += inc;
+    }
+
+    /*calculate the fall increment */
+    inc = height_norm[n] / (fft_peak[n + 1] - fft_peak[n]);
+
+    val = 0;
+    next_peak = fft_peak[n + 1];
+
+    /*reverse fill the 'fall' */
+    for(i = next_peak; i > fft_peak[n]; i--){ 
+      //fft_tables[n][i] = val;
+      fb->filters[n]->data[0][k]=val;
+      val += inc;
+    }
+
+    /*zero the rest of the array*/
+    for(k = next_peak + 1; k < fb->win_s; k++)
+      //fft_tables[n][k] = 0.f;
+      fb->filters[n]->data[0][k]=0.f;
+  }
+
+  free(mel_peak);
+  free(lin_peak);
+  free(height_norm);
+  free(fft_peak);
+
+  return fb;
 
 }
 
+
 void del_aubio_filterbank(aubio_filterbank_t * fb){
-  
-  int filter_cnt;
+  uint_t filter_cnt;
   /** deleting filter tables first */
   for (filter_cnt=0; filter_cnt<fb->n_filters; filter_cnt++)
@@ -56 +166 @@
   AUBIO_FREE(fb->filters);
   AUBIO_FREE(fb);
-
 }
 
+void aubio_filterbank_do(aubio_filterbank_t * f, cvec_t * in, fvec_t *out) {
+  uint_t n, filter_cnt;
+  for(filter_cnt = 0; filter_cnt < f->n_filters; filter_cnt++){
+      out->data[0][filter_cnt] = 0.f;
+      for(n = 0; n < f->win_s; n++){
+          out->data[0][filter_cnt] += in->norm[0][n] 
+            * f->filters[filter_cnt]->data[0][n];
+      }
+      out->data[0][filter_cnt] =
+        LOG(out->data[0][filter_cnt] < VERY_SMALL_NUMBER ? 
+            VERY_SMALL_NUMBER : out->data[0][filter_cnt]);
+  }
+
+  return;
+}