Changes in src/filterbank.c [45134c5:7c6c806d]

File:

• src/filterbank.c (modified) (2 diffs)

src/filterbank.c

@@ -1 +1 @@
 /*
-   Copyright (C) 2007 Amaury Hazan <ahazan@iua.upf.edu>
-                  and Paul Brossier <piem@piem.org>
+   Copyright (C) 2007 Amaury Hazan
+   Ported to aubio from LibXtract
+   http://libxtract.sourceforge.net/
+   
 
    This program is free software; you can redistribute it and/or modify
@@ -19 +21 @@
 */
 
-/* part of this mfcc implementation were inspired from LibXtract
-   http://libxtract.sourceforge.net/
-*/
-
 #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 */
-struct aubio_filterbank_t_ {
-    uint_t win_s;
-    uint_t n_filters;
-    fvec_t **filters;
+// Struct Declaration
+
+/** \brief A structure to store a set of n_filters Mel filters */
+typedef struct aubio_mel_filter_ {
+    int n_filters;
+    smpl_t **filters;
 };
 
-aubio_filterbank_t * new_aubio_filterbank(uint_t n_filters, uint_t win_s){
-  /** allocating space for filterbank object */
-  aubio_filterbank_t * fb = AUBIO_NEW(aubio_filterbank_t);
-  uint_t filter_cnt;
-  fb->win_s=win_s;
-  fb->n_filters=n_filters;
+// Initialization
 
-  /** allocating filter tables */
-  fb->filters=AUBIO_ARRAY(fvec_t*,n_filters);
-  for (filter_cnt=0; filter_cnt<n_filters; filter_cnt++)
-    /* considering one-channel filters */
-    fb->filters[filter_cnt]=new_fvec(win_s, 1);
+int aubio_mfcc_init(int N, smpl_t nyquist, int style, smpl_t freq_min, smpl_t freq_max, int freq_bands, smpl_t **fft_tables){
 
-  return fb;
-}
+    int 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;
 
-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);
+    mel_peak = height_norm = lin_peak = NULL;
+    fft_peak = NULL;
+    norm = 1; 
 
-  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_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) / freq_bands;
 
-  mel_peak = height_norm = lin_peak = NULL;
-  fft_peak = NULL;
-  norm = 1; 
+    mel_peak = (smpl_t *)malloc((freq_bands + 2) * sizeof(smpl_t)); 
+    /* +2 for zeros at start and end */
+    lin_peak = (smpl_t *)malloc((freq_bands + 2) * sizeof(smpl_t));
+    fft_peak = (int *)malloc((freq_bands + 2) * sizeof(int));
+    height_norm = (smpl_t *)malloc(freq_bands * sizeof(smpl_t));
 
-  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;
+    if(mel_peak == NULL || height_norm == NULL || 
+                    lin_peak == NULL || fft_peak == NULL)
+                    return XTRACT_MALLOC_FAILED;
+    
+    M = N >> 1;
 
-  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));
+    mel_peak[0] = mel_freq_min;
+    lin_peak[0] = 700 * (exp(mel_peak[0] / 1127) - 1);
+    fft_peak[0] = lin_peak[0] / nyquist * M;
 
-  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++){  
+    for (n = 1; n <= freq_bands; 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++)
-      fb->filters[n]->data[0][k]=0.f;
-
-    /*fill in the rise */
-    for(; i <= fft_peak[n]; i++){ 
-      fb->filters[n]->data[0][k]=val;
-      val += inc;
+        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;
     }
 
-    /*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--){ 
-      fb->filters[n]->data[0][k]=val;
-      val += inc;
+    for (n = 0; n < freq_bands; n++){
+        /*roll out normalised gain of each peak*/
+        if (style == XTRACT_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;
     }
 
-    /*zero the rest of the array*/
-    for(k = next_peak + 1; k < fb->win_s; k++)
-      fb->filters[n]->data[0][k]=0.f;
-  }
+    i = 0;
+   
+    for(n = 0; n < freq_bands; 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;
+  
+  /*fill in the rise */
+        for(; i <= fft_peak[n]; i++){ 
+            fft_tables[n][i] = 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;
+            val += inc;
+        }
 
-  free(mel_peak);
-  free(lin_peak);
-  free(height_norm);
-  free(fft_peak);
+  /*zero the rest of the array*/
+  for(k = next_peak + 1; k < N; k++)
+      fft_tables[n][k] = 0.f;
+    }
 
-  return fb;
+    free(mel_peak);
+    free(lin_peak);
+    free(height_norm);
+    free(fft_peak);
+
+    return XTRACT_SUCCESS;
 
 }
-
-
-void del_aubio_filterbank(aubio_filterbank_t * fb){
-  uint_t filter_cnt;
-  /** deleting filter tables first */
-  for (filter_cnt=0; filter_cnt<fb->n_filters; filter_cnt++)
-    del_fvec(fb->filters[filter_cnt]);
-  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->length); filter_cnt++){
-      out->data[0][filter_cnt] = 0.f;
-      for(n = 0; n < in->length; 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;
-}