Goertzel algorithm

Signed-off-by: Mattias Andrée <maandree@member.fsf.org>

1 files changed, 34 insertions, 0 deletions

diff --git a/src/goertzel.h b/src/goertzel.h
new file mode 100644
index 0000000..ad1e4b8
--- /dev/null
+++ b/src/goertzel.h
@@ -0,0 +1,34 @@
+/**
+ * Copyright © 2015  Mattias Andrée (maandree@member.fsf.org)
+ * 
+ * This program 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.
+ * 
+ * This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#include <stddef.h>
+#include <stdint.h>
+
+
+
+struct goertzel_state
+{
+  double prev1;
+  double prev2;
+  double power;
+  size_t n;
+  double k;
+};
+
+
+void goertzel_init(double freq, double rate, struct goertzel_state* restrict state);
+double goertzel(size_t n, const uint32_t* restrict samples, struct goertzel_state* restrict state);
+