src/spectral/constantq.c: first constant-q draft, plain implementation

diff --git a/src/aubio.h b/src/aubio.h
index 0d02136..8688300 100644 (file)
--- a/src/aubio.h
+++ b/src/aubio.h
@@ -183,6 +183,7 @@ extern "C"
 #include "temporal/c_weighting.h"
 #include "spectral/fft.h"
 #include "spectral/phasevoc.h"
+#include "spectral/constantq.h"
 #include "spectral/filterbank.h"
 #include "spectral/filterbank_mel.h"
 #include "spectral/mfcc.h"

diff --git a/src/spectral/constantq.c b/src/spectral/constantq.c
new file mode 100644 (file)
index 0000000..4293f3f
--- /dev/null
+++ b/src/spectral/constantq.c
@@ -0,0 +1,123 @@
+/*
+  Copyright (C) 2018 Paul Brossier <piem@aubio.org>
+
+  This file is part of aubio.
+
+  aubio 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 3 of the License, or
+  (at your option) any later version.
+
+  aubio 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 aubio.  If not, see <http://www.gnu.org/licenses/>.
+
+*/
+
+/** \file
+
+  Constant-Q Transform
+
+  TODO add long description
+
+  \example spectral/test-constantq.c
+
+*/
+
+#include "aubio_priv.h"
+#include "fvec.h"
+#include "cvec.h"
+#include "fmat.h"
+#include "spectral/constantq.h"
+
+struct _aubio_constantq_t {
+  uint_t size;
+  uint_t samplerate;
+  uint_t bins_per_octave;
+  fmat_t *coeffs;
+  smpl_t high_freq;
+  smpl_t low_freq;
+};
+
+uint_t aubio_constantq_reset_filters (aubio_constantq_t *s);
+
+aubio_constantq_t * new_aubio_constantq(uint_t size, uint_t samplerate,
+    uint_t bins_per_octave) {
+  aubio_constantq_t * s = AUBIO_NEW (aubio_constantq_t);
+  if ((sint_t) size <= 0) {
+    AUBIO_ERROR("constantq: failed creating with size %d, should be > 0\n",
+        size);
+    goto beach;
+  }
+  if ((sint_t) bins_per_octave <= 0) {
+    AUBIO_ERROR("constantq: failed creating with bins_per_octave %d"
+        ", should be > 0\n", bins_per_octave);
+    goto beach;
+  }
+
+  s->size = size / 2 + 1;
+  s->samplerate = samplerate;
+  s->bins_per_octave = bins_per_octave;
+  s->low_freq = aubio_miditofreq(19.0);
+  s->high_freq = aubio_miditofreq(MIN(140.0, 139.0 + 12.0/s->bins_per_octave));
+  if (aubio_constantq_reset_filters (s) != AUBIO_OK) goto beach;
+  //AUBIO_WRN ("constantq: %d size, %d Hz, %d bins\n", s->size, s->samplerate,
+  //    s->bins_per_octave);
+  return s;
+beach:
+  AUBIO_FREE(s);
+  return NULL;
+}
+
+uint_t aubio_constantq_reset_filters (aubio_constantq_t *s)
+{
+  // compute transform coefficients
+  uint_t i, j;
+  smpl_t ratio = POW(2.0, 1.0 / s->bins_per_octave);
+  uint_t nbins = (uint_t) FLOOR (LOG (s->high_freq / s->low_freq) / LOG (ratio));
+  if (nbins <= 0) {
+    AUBIO_ERROR ("constantq: can not be created with 0 bins, low_freq %.2f, "
+        "high_freq %.2f, bins_per_octave %d\n", s->low_freq, s->high_freq,
+        s->bins_per_octave);
+    return AUBIO_FAIL;
+  }
+  if (s->coeffs) del_fmat(s->coeffs);
+  s->coeffs = new_fmat (nbins, s->size);
+
+  smpl_t freq_step = s->samplerate * 0.5 / (s->size - 1.);
+  smpl_t min_bw = (smpl_t) s->samplerate / (smpl_t) s->size;
+
+  for (i = 0; i < nbins; i++) {
+    smpl_t band_freq = s->low_freq * POW (ratio, i);
+    smpl_t band_bw = MAX (band_freq * (ratio - 1.), min_bw);
+    for (j = 0; j < s->size; j++) {
+      smpl_t fftfreq = j * freq_step;
+      smpl_t val = (band_freq - fftfreq) / band_bw;
+      s->coeffs->data[i][j] = EXP (- 0.5 * SQR(val));
+    }
+  }
+
+  return AUBIO_OK;
+}
+
+void del_aubio_constantq(aubio_constantq_t *s) {
+  del_fmat(s->coeffs);
+  AUBIO_FREE(s);
+}
+
+void aubio_constantq_do(aubio_constantq_t *s, const cvec_t *input,
+    fvec_t *cqt_output) {
+  fvec_t input_norm;
+  input_norm.length = input->length;
+  input_norm.data = input->norm;
+  fmat_vecmul (s->coeffs, &input_norm, cqt_output);
+}
+
+uint_t aubio_constantq_get_numbins (aubio_constantq_t *s) {
+  if (!s || !s->coeffs) return 0;
+  return s->coeffs->height;
+}

diff --git a/src/spectral/constantq.h b/src/spectral/constantq.h
new file mode 100644 (file)
index 0000000..b57130b
--- /dev/null
+++ b/src/spectral/constantq.h
@@ -0,0 +1,84 @@
+/*
+  Copyright (C) 2017 Paul Brossier <piem@aubio.org>
+
+  This file is part of aubio.
+
+  aubio 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 3 of the License, or
+  (at your option) any later version.
+
+  aubio 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 aubio.  If not, see <http://www.gnu.org/licenses/>.
+
+*/
+
+/** \file
+
+  Constant-Q Transform
+
+  TODO add long description
+
+  \example spectral/test-constantq.c
+
+*/
+
+#ifndef AUBIO_CONSTANTQ_H
+#define AUBIO_CONSTANTQ_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/** Constant-Q transofmr object
+
+  This object computes the forward Constant-Q transform.
+
+*/
+typedef struct _aubio_constantq_t aubio_constantq_t;
+
+/** create new constant-Q computation object
+
+  \param size length of the Constant-Q
+  \param samplerate sampling rate of the input signal
+  \param bins_per_octave number of bins per octave
+
+*/
+aubio_constantq_t * new_aubio_constantq(uint_t size, uint_t samplerate,
+        uint_t bins_per_octave);
+
+/** compute constant-Q
+
+  \param s constant-Q object as returned by new_aubio_constantq
+  \param input input fft grain
+  \param cqt_output transformed input array
+
+*/
+void aubio_constantq_do (aubio_constantq_t *s, const cvec_t * input,
+        fvec_t * cqt_output);
+
+/** delete constant-q object
+
+  \param s constant-q object as returned by new_aubio_constantq
+
+*/
+void del_aubio_constantq (aubio_constantq_t *s);
+
+/** get number of output bins of a constant-q object
+
+  \param s constant-q object as returned by new_aubio_constantq
+  \return number of output bins
+
+*/
+uint_t aubio_constantq_get_numbins (aubio_constantq_t *s);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* AUBIO_CONSTANTQ_H */