Changes in / [7a46bf6:ef1c3b7]

Files:

• examples/aubiomfcc.c (modified) (2 diffs)
• src/filterbank.c (modified) (3 diffs)
• src/filterbank.h (modified) (2 diffs)
• src/mfcc.c (modified) (1 diff)
• src/mfcc.h (modified) (1 diff)

examples/aubiomfcc.c

@@ -87 +87 @@
 int main(int argc, char **argv) {
   // params
-  //uint_t n_filters = 40;
-  //uint_t n_coefs = 15;
-
+  
   examples_common_init(argc,argv);
   smpl_t lowfreq = 133.333f;
@@ -97 +95 @@
   //populating the filter
   mfcc = new_aubio_mfcc(buffer_size, samplerate, n_filters, n_coefs , lowfreq, highfreq, channels);
-
+  dump_filterbank(mfcc);
+  
   //process
   examples_common_process(aubio_process,process_print);

src/filterbank.c

@@ -57 +57 @@
 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){
   
-  uint_t writelog=1;
-
-  FILE * mlog;
-  if(writelog==1) mlog=fopen("filterbank.txt","w");
-  
-
   smpl_t nyquist = samplerate/2.;
   uint_t style = 1;
@@ -152 +146 @@
       fb->filters[n]->data[0][k]=0.f;
 
-    if(writelog){
-      //dumping filter values
-      smpl_t area_tmp=0.f;
-      for(k = 0; k < fb->win_s; k++){
-        fprintf(mlog,"%f ",fb->filters[n]->data[0][k]);
-      }
-      fprintf(mlog,"\n");
-    }
 
   }
@@ -168 +154 @@
   free(fft_peak);
 
+
+  return fb;
+
+}
+
+
+aubio_filterbank_t * new_aubio_filterbank_mfcc2(uint_t n_filters, uint_t win_s, smpl_t samplerate, smpl_t freq_min, smpl_t freq_max){
+  
+  //slaney params
+  smpl_t lowestFrequency = 133.3333;
+  smpl_t linearSpacing = 66.66666666;
+  smpl_t logSpacing = 1.0711703;
+
+  uint_t linearFilters = 13;
+  uint_t logFilters = 27;
+  uint_t allFilters = linearFilters + logFilters;
+  
+  //buffers for computing filter frequencies
+  fvec_t * freqs=new_fvec( allFilters +2 , 1);
+  fvec_t * lower_freqs=new_fvec( allFilters, 1);
+  fvec_t * upper_freqs=new_fvec( allFilters, 1);
+  fvec_t * center_freqs=new_fvec( allFilters, 1);
+  fvec_t * triangle_heights=new_fvec( allFilters, 1);
+  //lookup table of each bin frequency in hz
+  fvec_t * fft_freqs=(win_s, 1);
+
+  uint_t filter_cnt, bin_cnt;
+  
+  //first: filling all the linear filter frequencies
+  for(filter_cnt=0; filter_cnt<linearFilters; filter_cnt++){
+    freqs[0][filter_cnt]=lowestFrequency+ filter_cnt*linearSpacing;
+  }
+  smpl_t lastlinearCF=freqs[0][filter_cnt-1];
+  
+  //second: filling all the log filter frequencies
+  for(filter_cnt=0; filter_cnt<logFilters+2; filter_cnt++){
+    freqs[filter_cnt+linearFilters]=lastlinearCF*(pow(logSpacing,filter_cnt+1));
+  }
+  //TODO: check if the referencing above works!
+  lower_freqs->data=freqs->data;
+  center_freqs->data=&(freqs->data[1]);
+  upper_freqs->data=&(freqs->data[2]);
+  
+  //computing triangle heights so that each triangle has unit area
+  for(filter_cnt=0; filter_cnt<allFilters; filter_cnt++){
+    triangle_heights[filter_cnt]=2./(upper_freqs[filter_cnt]-lower_freqs[filter_cnt]);
+  }
+
+  //filling the lookup table, which assign the frequency in hz to each bin
+  for(bin_cnt=0; bin_cnt<win_s; bin_cnt++){
+    //TODO: check the formula!
+    fft_freqs[bin_cnt]=((smpl_t) bin_cnt/(smpl_t) win_s)* (smpl_t) samplerate;
+  }
+  
+  //building each filter
+  for(filter_cnt=0; filter_cnt<allFilters; filter_cnt++){
+    //finding bins corresponding to lower, center, and upper frequencies
+
+    for(bin_cnt=0; bin_cnt<; bin_cnt++)
+      fb->filters[filter_cnt]->data[0][bin_cnt]=0.f;
+  }
+  
+  // xtract
+  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++)
+      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;
+    }
+
+    /*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;
+    }
+
+    /*zero the rest of the array*/
+    for(k = next_peak + 1; k < fb->win_s; k++)
+      fb->filters[n]->data[0][k]=0.f;
+
+
+  }
+
+  free(mel_peak);
+  free(lin_peak);
+  free(height_norm);
+  free(fft_peak);
+
+
+  return fb;
+
+}
+
+void aubio_dump_filterbank(aubio_filterbank_t * fb){
+
+  FILE * mlog;
+  mlog=fopen("filterbank.txt","w");
+  
+  int k,n;
+  //dumping filter values
+  //smpl_t area_tmp=0.f;
+  for(n = 0; n < fb->n_filters; n++){
+    for(k = 0; k < fb->win_s; k++){
+      fprintf(mlog,"%f ",fb->filters[n]->data[0][k]);
+    }
+    fprintf(mlog,"\n");
+  }
+  
   if(mlog) fclose(mlog);
-
-  return fb;
-
-}
-
+}
 
 void del_aubio_filterbank(aubio_filterbank_t * fb){

src/filterbank.h

@@ -46 +46 @@
 /** filterbank initialization for mel filters
 
-  \param nyquist nyquist frequency, i.e. half of the sampling rate
-  \param style libxtract style
-  \param freqmin lowest filter frequency
-  \param freqmax highest filter frequency
+  
+  \param n_filters number of filters
+  \param win_s window size
+  \param samplerate
+  \param freq_min lowest filter frequency
+  \param freq_max highest filter frequency
 
 */
 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);
+
+/** filterbank initialization for mel filters
+
+  \param n_filters number of filters
+  \param win_s window size
+  \param samplerate
+  \param freq_min lowest filter frequency
+  \param freq_max highest filter frequency
+
+*/
+aubio_filterbank_t * new_aubio_filterbank_mfcc_2(uint_t n_filters, uint_t win_s, smpl_t samplerate, smpl_t freq_min, smpl_t freq_max);
 
 
@@ -67 +80 @@
 void aubio_filterbank_do(aubio_filterbank_t * fb, cvec_t * in, fvec_t *out);
 
+/** dump filterbank filter tables in a txt file
+
+*/
+void aubio_dump_filterbank(aubio_filterbank_t * fb);
+
 #ifdef __cplusplus
 }

src/mfcc.c

@@ -112 +112 @@
 }
 
+//a bit a kludge
+void dump_filterbank(aubio_mfcc_t * mf){
+  aubio_dump_filterbank(mf->fb);
+
+}
+

src/mfcc.h

@@ -70 +70 @@
 void aubio_dct_do(aubio_mfcc_t * mf, fvec_t *in, fvec_t *out);
 
+/** dump filterbank to log file
+
+  \param mf mfcc object as returned by new_aubio_mfcc
+  
+*/
+void dump_filterbank(aubio_mfcc_t * mf);
+
 #ifdef __cplusplus
 }