--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/spandsp-0.0.6pre17/src/spandsp/complex_filters.h	Fri Jun 25 15:50:58 2010 +0200
@@ -0,0 +1,75 @@
+/*
+ * SpanDSP - a series of DSP components for telephony
+ *
+ * complex_filters.h
+ *
+ * Written by Steve Underwood <steveu@coppice.org>
+ *
+ * Copyright (C) 2003 Steve Underwood
+ *
+ * All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1,
+ * as published by the Free Software Foundation.
+ *
+ * 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 Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ * $Id: complex_filters.h,v 1.14 2009/02/03 16:28:41 steveu Exp $
+ */
+
+#if !defined(_SPANDSP_COMPLEX_FILTERS_H_)
+#define _SPANDSP_COMPLEX_FILTERS_H_
+
+typedef struct filter_s filter_t;
+
+typedef float (*filter_step_func_t)(filter_t *fi, float x);
+
+/*! Filter state */
+typedef struct
+{
+    int nz;
+    int np;
+    filter_step_func_t fsf;
+} fspec_t;
+
+struct filter_s
+{
+    fspec_t *fs;
+    float sum;
+    int ptr;            /* Only for moving average filters */
+    float v[];
+};
+
+typedef struct
+{
+    filter_t *ref;
+    filter_t *imf;
+} cfilter_t;
+
+#if defined(__cplusplus)
+extern "C"
+{
+#endif
+
+SPAN_DECLARE(filter_t *) filter_create(fspec_t *fs);
+SPAN_DECLARE(void) filter_delete(filter_t *fi);
+SPAN_DECLARE(float) filter_step(filter_t *fi, float x);
+
+SPAN_DECLARE(cfilter_t *) cfilter_create(fspec_t *fs);
+SPAN_DECLARE(void) cfilter_delete(cfilter_t *cfi);
+SPAN_DECLARE(complexf_t) cfilter_step(cfilter_t *cfi, const complexf_t *z);
+
+#if defined(__cplusplus)
+}
+#endif
+
+#endif
+/*- End of file ------------------------------------------------------------*/