1 files changed, 203 insertions, 0 deletions
diff --git a/src/onset/peakpicker.c b/src/onset/peakpicker.c
new file mode 100644
index 0000000..0d83bec
--- /dev/null
+++ b/src/onset/peakpicker.c
@@ -0,0 +1,203 @@
+/*
+  Copyright (C) 2003-2009 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/>.
+
+*/
+
+#include "aubio_priv.h"
+#include "fvec.h"
+#include "mathutils.h"
+#include "lvec.h"
+#include "temporal/filter.h"
+#include "temporal/biquad.h"
+#include "onset/peakpicker.h"
+
+/** function pointer to thresholding function */
+typedef smpl_t (*aubio_thresholdfn_t)(fvec_t *input);
+/** function pointer to peak-picking function */
+typedef uint_t (*aubio_pickerfn_t)(fvec_t *input, uint_t pos);
+
+/** set peak picker thresholding function */
+uint_t aubio_peakpicker_set_thresholdfn(aubio_peakpicker_t * p, aubio_thresholdfn_t thresholdfn);
+/** get peak picker thresholding function */
+aubio_thresholdfn_t aubio_peakpicker_get_thresholdfn(aubio_peakpicker_t * p);
+
+/* peak picking parameters, default values in brackets
+ *
+ *     [<----post----|--pre-->]
+ *  .................|.............
+ *  time->           ^now
+ */
+struct _aubio_peakpicker_t
+{
+        /** thresh: offset threshold [0.033 or 0.01] */
+  smpl_t threshold;
+        /** win_post: median filter window length (causal part) [8] */
+  uint_t win_post;
+        /** pre: median filter window (anti-causal part) [post-1] */
+  uint_t win_pre;
+        /** threshfn: name or handle of fn for computing adaptive threshold [median]  */
+  aubio_thresholdfn_t thresholdfn;
+        /** picker: name or handle of fn for picking event times [peakpick] */
+  aubio_pickerfn_t pickerfn;
+
+        /** biquad lowpass filter */
+  aubio_filter_t *biquad;
+        /** original onsets */
+  fvec_t *onset_keep;
+        /** modified onsets */
+  fvec_t *onset_proc;
+        /** peak picked window [3] */
+  fvec_t *onset_peek;
+        /** thresholded function */
+  fvec_t *thresholded;
+        /** scratch pad for biquad and median */
+  fvec_t *scratch;
+
+        /** \bug should be used to calculate filter coefficients */
+  /* cutoff: low-pass filter cutoff [0.34, 1] */
+  /* smpl_t cutoff; */
+
+  /* not used anymore */
+  /* time precision [512/44100  winlength/samplerate, fs/buffer_size */
+  /* smpl_t tau; */
+  /* alpha: normalisation exponent [9] */
+  /* smpl_t alpha; */
+};
+
+
+/** modified version for real time, moving mean adaptive threshold this method
+ * is slightly more permissive than the offline one, and yelds to an increase
+ * of false positives. best  */
+void
+aubio_peakpicker_do (aubio_peakpicker_t * p, fvec_t * onset, fvec_t * out)
+{
+  fvec_t *onset_keep = p->onset_keep;
+  fvec_t *onset_proc = p->onset_proc;
+  fvec_t *onset_peek = p->onset_peek;
+  fvec_t *thresholded = p->thresholded;
+  fvec_t *scratch = p->scratch;
+  smpl_t mean = 0., median = 0.;
+  uint_t length = p->win_post + p->win_pre + 1;
+  uint_t j = 0;
+
+  /* store onset in onset_keep */
+  /* shift all elements but last, then write last */
+  for (j = 0; j < length - 1; j++) {
+    onset_keep->data[j] = onset_keep->data[j + 1];
+    onset_proc->data[j] = onset_keep->data[j];
+  }
+  onset_keep->data[length - 1] = onset->data[0];
+  onset_proc->data[length - 1] = onset->data[0];
+
+  /* filter onset_proc */
+  /** \bug filtfilt calculated post+pre times, should be only once !? */
+  aubio_filter_do_filtfilt (p->biquad, onset_proc, scratch);
+
+  /* calculate mean and median for onset_proc */
+  mean = fvec_mean (onset_proc);
+  /* copy to scratch */
+  for (j = 0; j < length; j++)
+    scratch->data[j] = onset_proc->data[j];
+  median = p->thresholdfn (scratch);
+
+  /* shift peek array */
+  for (j = 0; j < 3 - 1; j++)
+    onset_peek->data[j] = onset_peek->data[j + 1];
+  /* calculate new tresholded value */
+  thresholded->data[0] =
+      onset_proc->data[p->win_post] - median - mean * p->threshold;
+  onset_peek->data[2] = thresholded->data[0];
+  out->data[0] = (p->pickerfn) (onset_peek, 1);
+  if (out->data[0]) {
+    out->data[0] = fvec_quadratic_peak_pos (onset_peek, 1);
+  }
+}
+
+/** this method returns the current value in the pick peaking buffer
+ * after smoothing
+ */
+fvec_t *
+aubio_peakpicker_get_thresholded_input (aubio_peakpicker_t * p)
+{
+  return p->thresholded;
+}
+
+uint_t
+aubio_peakpicker_set_threshold (aubio_peakpicker_t * p, smpl_t threshold)
+{
+  p->threshold = threshold;
+  return AUBIO_OK;
+}
+
+smpl_t
+aubio_peakpicker_get_threshold (aubio_peakpicker_t * p)
+{
+  return p->threshold;
+}
+
+uint_t
+aubio_peakpicker_set_thresholdfn (aubio_peakpicker_t * p,
+    aubio_thresholdfn_t thresholdfn)
+{
+  p->thresholdfn = thresholdfn;
+  return AUBIO_OK;
+}
+
+aubio_thresholdfn_t
+aubio_peakpicker_get_thresholdfn (aubio_peakpicker_t * p)
+{
+  return (aubio_thresholdfn_t) (p->thresholdfn);
+}
+
+aubio_peakpicker_t *
+new_aubio_peakpicker (void)
+{
+  aubio_peakpicker_t *t = AUBIO_NEW (aubio_peakpicker_t);
+  t->threshold = 0.1;           /* 0.0668; 0.33; 0.082; 0.033; */
+  t->win_post = 5;
+  t->win_pre = 1;
+
+  t->thresholdfn = (aubio_thresholdfn_t) (fvec_median); /* (fvec_mean); */
+  t->pickerfn = (aubio_pickerfn_t) (fvec_peakpick);
+
+  t->scratch = new_fvec (t->win_post + t->win_pre + 1);
+  t->onset_keep = new_fvec (t->win_post + t->win_pre + 1);
+  t->onset_proc = new_fvec (t->win_post + t->win_pre + 1);
+  t->onset_peek = new_fvec (3);
+  t->thresholded = new_fvec (1);
+
+  /* cutoff: low-pass filter with cutoff reduced frequency at 0.34
+     generated with octave butter function: [b,a] = butter(2, 0.34);
+   */
+  t->biquad = new_aubio_filter_biquad (0.15998789, 0.31997577, 0.15998789,
+      -0.59488894, 0.23484048);
+
+  return t;
+}
+
+void
+del_aubio_peakpicker (aubio_peakpicker_t * p)
+{
+  del_aubio_filter (p->biquad);
+  del_fvec (p->onset_keep);
+  del_fvec (p->onset_proc);
+  del_fvec (p->onset_peek);
+  del_fvec (p->thresholded);
+  del_fvec (p->scratch);
+  AUBIO_FREE (p);
+}