comparison libs/aubioFullOSXUni/include/aubio/biquad.h @ 0:bcb0d40158f4

started audio file loader project - using oF_061

+/*
+	 Copyright (C) 2003 Paul Brossier
+
+	 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 2 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, write to the Free Software
+	 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+*/
+
+#ifndef BIQUAD_H
+#define BIQUAD_H
+
+/** \file 
+
+  Second order Infinite Impulse Response filter
+
+  This file implements a normalised biquad filter (second order IIR):
+ 
+  \f$ y[n] = b_1 x[n] + b_2 x[n-1] + b_3 x[n-2] - a_2 y[n-1] - a_3 y[n-2] \f$
+
+  The filtfilt version runs the filter twice, forward and backward, to
+  compensate the phase shifting of the forward operation.
+
+*/
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/** biquad filter object */
+typedef struct _aubio_biquad_t aubio_biquad_t;
+
+/** filter input vector
+
+  \param b biquad object as returned by new_aubio_biquad
+  \param in input vector to filter
+
+*/
+void aubio_biquad_do(aubio_biquad_t * b, fvec_t * in);
+/** filter input vector forward and backward
+
+  \param b biquad object as returned by new_aubio_biquad
+  \param in input vector to filter
+  \param tmp memory space to use for computation
+
+*/
+void aubio_biquad_do_filtfilt(aubio_biquad_t * b, fvec_t * in, fvec_t * tmp);
+/** create new biquad filter
+
+  \param b1 forward filter coefficient
+  \param b2 forward filter coefficient
+  \param b3 forward filter coefficient
+  \param a2 feedback filter coefficient
+  \param a3 feedback filter coefficient
+
+*/
+aubio_biquad_t * new_aubio_biquad(lsmp_t b1, lsmp_t b2, lsmp_t b3, lsmp_t a2, lsmp_t a3);
+
+/** delete biquad filter 
+ 
+  \param b biquad object to delete 
+
+*/
+void del_aubio_biquad(aubio_biquad_t * b);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /*BIQUAD_H*/