1 /* -*- c-basic-offset: 2 -*-
4 * Copyright (C) 1999-2001 Erik Walthinsen <omega@cse.ogi.edu>
5 * 2006 Dreamlab Technologies Ltd. <mathis.hofer@dreamlab.net>
7 * This library is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Library General Public
9 * License as published by the Free Software Foundation; either
10 * version 2 of the License, or (at your option) any later version.
12 * This library is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Library General Public License for more details.
17 * You should have received a copy of the GNU Library General Public
18 * License along with this library; if not, write to the
19 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
20 * Boston, MA 02111-1307, USA.
23 * this windowed sinc filter is taken from the freely downloadable DSP book,
24 * "The Scientist and Engineer's Guide to Digital Signal Processing",
26 * available at http://www.dspguide.com/
30 #ifndef __GST_LPWSINC_H__
31 #define __GST_LPWSINC_H__
33 #include "gstfilter.h"
35 #include <gst/audio/gstaudiofilter.h>
39 #define GST_TYPE_LPWSINC \
40 (gst_lpwsinc_get_type())
41 #define GST_LPWSINC(obj) \
42 (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_LPWSINC,GstLPWSinc))
43 #define GST_LPWSINC_CLASS(klass) \
44 (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_LPWSINC,GstLPWSincClass))
45 #define GST_IS_LPWSINC(obj) \
46 (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_LPWSINC))
47 #define GST_IS_LPWSINC_CLASS(klass) \
48 (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_LPWSINC))
50 typedef struct _GstLPWSinc GstLPWSinc;
51 typedef struct _GstLPWSincClass GstLPWSincClass;
53 typedef void (*GstLPWSincProcessFunc) (GstLPWSinc *, guint8 *, guint8 *, guint);
58 * Opaque data structure.
61 GstAudioFilter element;
64 GstLPWSincProcessFunc process;
69 gint kernel_length; /* length of the filter kernel */
71 gdouble *residue; /* buffer for left-over samples from previous buffer */
72 gdouble *kernel; /* filter kernel */
80 struct _GstLPWSincClass {
81 GstAudioFilterClass parent_class;
84 GType gst_lpwsinc_get_type (void);
88 #endif /* __GST_LPWSINC_H__ */