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/
29 * - this filter is totally unoptimized !
30 * - we do not destroy the allocated memory for filters and residue
31 * - this might be improved upon with bytestream
34 #ifndef __GST_LPWSINC_H__
35 #define __GST_LPWSINC_H__
37 #include "gstfilter.h"
39 #include <gst/base/gstbasetransform.h>
43 #define GST_TYPE_LPWSINC \
44 (gst_lpwsinc_get_type())
45 #define GST_LPWSINC(obj) \
46 (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_LPWSINC,GstLPWSinc))
47 #define GST_LPWSINC_CLASS(klass) \
48 (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_LPWSINC,GstLPWSincClass))
49 #define GST_IS_LPWSINC(obj) \
50 (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_LPWSINC))
51 #define GST_IS_LPWSINC_CLASS(klass) \
52 (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_LPWSINC))
54 typedef struct _GstLPWSinc GstLPWSinc;
55 typedef struct _GstLPWSincClass GstLPWSincClass;
60 * Opaque data structure.
63 GstBaseTransform element;
65 void (*process)(GstLPWSinc*, gpointer, gint);
68 int wing_size; /* length of a "wing" of the filter;
69 actual length is 2 * wing_size + 1 */
71 gfloat *residue; /* buffer for left-over samples from previous buffer */
75 struct _GstLPWSincClass {
76 GstBaseTransformClass parent_class;
81 #endif /* __GST_LPWSINC_H__ */