uint_t
aubio_filterbank_set_triangle_bands (aubio_filterbank_t * fb,
- fvec_t * freqs, smpl_t samplerate)
+ const fvec_t * freqs, smpl_t samplerate)
{
fmat_t *filters = aubio_filterbank_get_coeffs (fb);
uint_t n_filters = filters->height, win_s = filters->length;
+ fvec_t *lower_freqs, *upper_freqs, *center_freqs;
+ fvec_t *triangle_heights, *fft_freqs;
uint_t fn; /* filter counter */
uint_t bin; /* bin counter */
+ smpl_t riseInc, downInc;
+
/* freqs define the bands of triangular overlapping windows.
throw a warning if filterbank object fb is too short. */
if (freqs->length - 2 > n_filters) {
n_filters, freqs->length - 2);
}
- if (freqs->data[freqs->length - 1] > samplerate / 2) {
- AUBIO_WRN ("Nyquist frequency is %fHz, but highest frequency band ends at \
-%fHz\n", samplerate / 2, freqs->data[freqs->length - 1]);
+ for (fn = 0; fn < freqs->length; fn++) {
+ if (freqs->data[fn] < 0) {
+ AUBIO_ERR("filterbank_mel: freqs must contain only positive values.\n");
+ return AUBIO_FAIL;
+ } else if (freqs->data[fn] > samplerate / 2) {
+ AUBIO_WRN("filterbank_mel: freqs should contain only "
+ "values < samplerate / 2.\n");
+ } else if (fn > 0 && freqs->data[fn] < freqs->data[fn-1]) {
+ AUBIO_ERR("filterbank_mel: freqs should be a list of frequencies "
+ "sorted from low to high, but freq[%d] < freq[%d-1]\n", fn, fn);
+ return AUBIO_FAIL;
+ } else if (fn > 0 && freqs->data[fn] == freqs->data[fn-1]) {
+ AUBIO_WRN("filterbank_mel: set_triangle_bands received a list "
+ "with twice the frequency %f\n", freqs->data[fn]);
+ }
}
/* convenience reference to lower/center/upper frequency for each triangle */
- fvec_t *lower_freqs = new_fvec (n_filters);
- fvec_t *upper_freqs = new_fvec (n_filters);
- fvec_t *center_freqs = new_fvec (n_filters);
+ lower_freqs = new_fvec (n_filters);
+ upper_freqs = new_fvec (n_filters);
+ center_freqs = new_fvec (n_filters);
/* height of each triangle */
- fvec_t *triangle_heights = new_fvec (n_filters);
+ triangle_heights = new_fvec (n_filters);
/* lookup table of each bin frequency in hz */
- fvec_t *fft_freqs = new_fvec (win_s);
+ fft_freqs = new_fvec (win_s);
/* fill up the lower/center/upper */
for (fn = 0; fn < n_filters; fn++) {
}
/* compute triangle heights so that each triangle has unit area */
- for (fn = 0; fn < n_filters; fn++) {
- triangle_heights->data[fn] =
- 2. / (upper_freqs->data[fn] - lower_freqs->data[fn]);
+ if (aubio_filterbank_get_norm(fb)) {
+ for (fn = 0; fn < n_filters; fn++) {
+ triangle_heights->data[fn] =
+ 2. / (upper_freqs->data[fn] - lower_freqs->data[fn]);
+ }
+ } else {
+ fvec_ones (triangle_heights);
}
/* fill fft_freqs lookup table, which assigns the frequency in hz to each bin */
/* zeroing of all filters */
fmat_zeros (filters);
- if (fft_freqs->data[1] >= lower_freqs->data[0]) {
- /* - 1 to make sure we don't miss the smallest power of two */
- uint_t min_win_s =
- (uint_t) FLOOR (samplerate / lower_freqs->data[0]) - 1;
- AUBIO_WRN ("Lowest frequency bin (%.2fHz) is higher than lowest frequency \
-band (%.2f-%.2fHz). Consider increasing the window size from %d to %d.\n",
- fft_freqs->data[1], lower_freqs->data[0],
- upper_freqs->data[0], (win_s - 1) * 2,
- aubio_next_power_of_two (min_win_s));
- }
-
/* building each filter table */
for (fn = 0; fn < n_filters; fn++) {
}
/* compute positive slope step size */
- smpl_t riseInc =
- triangle_heights->data[fn] /
- (center_freqs->data[fn] - lower_freqs->data[fn]);
+ riseInc = triangle_heights->data[fn]
+ / (center_freqs->data[fn] - lower_freqs->data[fn]);
/* compute coefficients in positive slope */
for (; bin < win_s - 1; bin++) {
}
/* compute negative slope step size */
- smpl_t downInc =
- triangle_heights->data[fn] /
- (upper_freqs->data[fn] - center_freqs->data[fn]);
+ downInc = triangle_heights->data[fn]
+ / (upper_freqs->data[fn] - center_freqs->data[fn]);
/* compute coefficents in negative slope */
for (; bin < win_s - 1; bin++) {
del_fvec (triangle_heights);
del_fvec (fft_freqs);
- return 0;
+ return AUBIO_OK;
}
uint_t
uint_t fn; /* filter counter */
+ smpl_t lastlinearCF;
+
/* buffers to compute filter frequencies */
- fvec_t *freqs = new_fvec (n_filters + 2);
+ fvec_t *freqs;
+
+ if (samplerate <= 0) {
+ AUBIO_ERR("filterbank: set_mel_coeffs_slaney samplerate should be > 0\n");
+ return AUBIO_FAIL;
+ }
+
+ freqs = new_fvec (n_filters + 2);
/* first step: fill all the linear filter frequencies */
for (fn = 0; fn < linearFilters; fn++) {
freqs->data[fn] = lowestFrequency + fn * linearSpacing;
}
- smpl_t lastlinearCF = freqs->data[fn - 1];
+ lastlinearCF = freqs->data[fn - 1];
/* second step: fill all the log filter frequencies */
for (fn = 0; fn < logFilters + 2; fn++) {
return retval;
}
+
+static uint_t aubio_filterbank_check_freqs (aubio_filterbank_t *fb UNUSED,
+ smpl_t samplerate, smpl_t *freq_min, smpl_t *freq_max)
+{
+ if (samplerate <= 0) {
+ AUBIO_ERR("filterbank: set_mel_coeffs samplerate should be > 0\n");
+ return AUBIO_FAIL;
+ }
+ if (*freq_max < 0) {
+ AUBIO_ERR("filterbank: set_mel_coeffs freq_max should be > 0\n");
+ return AUBIO_FAIL;
+ } else if (*freq_max == 0) {
+ *freq_max = samplerate / 2.;
+ }
+ if (*freq_min < 0) {
+ AUBIO_ERR("filterbank: set_mel_coeffs freq_min should be > 0\n");
+ return AUBIO_FAIL;
+ }
+ return AUBIO_OK;
+}
+
+uint_t
+aubio_filterbank_set_mel_coeffs (aubio_filterbank_t * fb, smpl_t samplerate,
+ smpl_t freq_min, smpl_t freq_max)
+{
+ uint_t m, retval;
+ smpl_t start = freq_min, end = freq_max, step;
+ fvec_t *freqs;
+ fmat_t *coeffs = aubio_filterbank_get_coeffs(fb);
+ uint_t n_bands = coeffs->height;
+
+ if (aubio_filterbank_check_freqs(fb, samplerate, &start, &end)) {
+ return AUBIO_FAIL;
+ }
+
+ start = aubio_hztomel(start);
+ end = aubio_hztomel(end);
+
+ freqs = new_fvec(n_bands + 2);
+ step = (end - start) / (n_bands + 1);
+
+ for (m = 0; m < n_bands + 2; m++)
+ {
+ freqs->data[m] = MIN(aubio_meltohz(start + step * m), samplerate/2.);
+ }
+
+ retval = aubio_filterbank_set_triangle_bands (fb, freqs, samplerate);
+
+ /* destroy vector used to store frequency limits */
+ del_fvec (freqs);
+ return retval;
+}
+
+uint_t
+aubio_filterbank_set_mel_coeffs_htk (aubio_filterbank_t * fb, smpl_t samplerate,
+ smpl_t freq_min, smpl_t freq_max)
+{
+ uint_t m, retval;
+ smpl_t start = freq_min, end = freq_max, step;
+ fvec_t *freqs;
+ fmat_t *coeffs = aubio_filterbank_get_coeffs(fb);
+ uint_t n_bands = coeffs->height;
+
+ if (aubio_filterbank_check_freqs(fb, samplerate, &start, &end)) {
+ return AUBIO_FAIL;
+ }
+
+ start = aubio_hztomel_htk(start);
+ end = aubio_hztomel_htk(end);
+
+ freqs = new_fvec (n_bands + 2);
+ step = (end - start) / (n_bands + 1);
+
+ for (m = 0; m < n_bands + 2; m++)
+ {
+ freqs->data[m] = MIN(aubio_meltohz_htk(start + step * m), samplerate/2.);
+ }
+
+ retval = aubio_filterbank_set_triangle_bands (fb, freqs, samplerate);
+
+ /* destroy vector used to store frequency limits */
+ del_fvec (freqs);
+ return retval;
+}
projects / aubio.git / blobdiff