1 files changed, 119 insertions, 0 deletions
diff --git a/src/pitch/pitchschmitt.c b/src/pitch/pitchschmitt.c
new file mode 100644
index 0000000..06a34e8
--- /dev/null
+++ b/src/pitch/pitchschmitt.c
@@ -0,0 +1,119 @@
+/*
+  Copyright (C) 2004, 2005  Mario Lang <mlang@delysid.org>
+  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 "pitch/pitchschmitt.h"
+
+smpl_t aubio_schmittS16LE (aubio_pitchschmitt_t * p, uint_t nframes,
+    signed short int *indata);
+
+struct _aubio_pitchschmitt_t
+{
+  uint_t blockSize;
+  uint_t rate;
+  signed short int *schmittBuffer;
+  signed short int *schmittPointer;
+  signed short int *buf;
+};
+
+aubio_pitchschmitt_t *
+new_aubio_pitchschmitt (uint_t size)
+{
+  aubio_pitchschmitt_t *p = AUBIO_NEW (aubio_pitchschmitt_t);
+  p->blockSize = size;
+  p->schmittBuffer = AUBIO_ARRAY (signed short int, p->blockSize);
+  p->buf = AUBIO_ARRAY (signed short int, p->blockSize);
+  p->schmittPointer = p->schmittBuffer;
+  return p;
+}
+
+void
+aubio_pitchschmitt_do (aubio_pitchschmitt_t * p, const fvec_t * input,
+    fvec_t * output)
+{
+  uint_t j;
+  for (j = 0; j < input->length; j++) {
+    p->buf[j] = input->data[j] * 32768.;
+  }
+  output->data[0] = aubio_schmittS16LE (p, input->length, p->buf);
+}
+
+smpl_t
+aubio_schmittS16LE (aubio_pitchschmitt_t * p, uint_t nframes,
+    signed short int *indata)
+{
+  uint_t i, j;
+  uint_t blockSize = p->blockSize;
+  signed short int *schmittBuffer = p->schmittBuffer;
+  signed short int *schmittPointer = p->schmittPointer;
+
+  smpl_t period = 0., trigfact = 0.6;
+
+  for (i = 0; i < nframes; i++) {
+    *schmittPointer++ = indata[i];
+    if (schmittPointer - schmittBuffer >= (sint_t) blockSize) {
+      sint_t endpoint, startpoint, t1, t2, A1, A2, tc, schmittTriggered;
+
+      schmittPointer = schmittBuffer;
+
+      for (j = 0, A1 = 0, A2 = 0; j < blockSize; j++) {
+        if (schmittBuffer[j] > 0 && A1 < schmittBuffer[j])
+          A1 = schmittBuffer[j];
+        if (schmittBuffer[j] < 0 && A2 < -schmittBuffer[j])
+          A2 = -schmittBuffer[j];
+      }
+      t1 = (sint_t) (A1 * trigfact + 0.5);
+      t2 = -(sint_t) (A2 * trigfact + 0.5);
+      startpoint = 0;
+      for (j = 1; j < blockSize && schmittBuffer[j] <= t1; j++);
+      for (     ; j < blockSize - 1 && !(schmittBuffer[j] >= t2 &&
+             schmittBuffer[j + 1] < t2); j++);
+      startpoint = j;
+      schmittTriggered = 0;
+      endpoint = startpoint + 1;
+      for (j = startpoint, tc = 0; j < blockSize; j++) {
+        if (!schmittTriggered) {
+          schmittTriggered = (schmittBuffer[j] >= t1);
+        } else if (schmittBuffer[j] >= t2 && schmittBuffer[j + 1] < t2) {
+          endpoint = j;
+          tc++;
+          schmittTriggered = 0;
+        }
+      }
+      if ((endpoint > startpoint) && (tc > 0)) {
+        period = (smpl_t) (endpoint - startpoint) / tc;
+      }
+    }
+  }
+
+  p->schmittBuffer = schmittBuffer;
+  p->schmittPointer = schmittPointer;
+  return period;
+}
+
+void
+del_aubio_pitchschmitt (aubio_pitchschmitt_t * p)
+{
+  AUBIO_FREE (p->schmittBuffer);
+  AUBIO_FREE (p->buf);
+  AUBIO_FREE (p);
+}