1 files changed, 54 insertions, 0 deletions
diff --git a/src/temporal/biquad.c b/src/temporal/biquad.c
new file mode 100644
index 0000000..6a03aa6
--- /dev/null
+++ b/src/temporal/biquad.c
@@ -0,0 +1,54 @@
+/*
+  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 "lvec.h"
+#include "temporal/filter.h"
+#include "temporal/biquad.h"
+
+uint_t
+aubio_filter_set_biquad (aubio_filter_t * f, lsmp_t b0, lsmp_t b1, lsmp_t b2,
+    lsmp_t a1, lsmp_t a2)
+{
+  uint_t order = aubio_filter_get_order (f);
+  lvec_t *bs = aubio_filter_get_feedforward (f);
+  lvec_t *as = aubio_filter_get_feedback (f);
+
+  if (order != 3) {
+    AUBIO_ERROR ("order of biquad filter must be 3, not %d\n", order);
+    return AUBIO_FAIL;
+  }
+  bs->data[0] = b0;
+  bs->data[1] = b1;
+  bs->data[2] = b2;
+  as->data[0] = 1.;
+  as->data[1] = a1;
+  as->data[1] = a2;
+  return AUBIO_OK;
+}
+
+aubio_filter_t *
+new_aubio_filter_biquad (lsmp_t b0, lsmp_t b1, lsmp_t b2, lsmp_t a1, lsmp_t a2)
+{
+  aubio_filter_t *f = new_aubio_filter (3);
+  aubio_filter_set_biquad (f, b0, b1, b2, a1, a2);
+  return f;
+}