1 /*
2  * GStreamer
3  * Copyright (C) 2007-2009 Sebastian Dröge <sebastian.droege@collabora.co.uk>
4  *
5  * This library is free software; you can redistribute it and/or
6  * modify it under the terms of the GNU Library General Public
7  * License as published by the Free Software Foundation; either
8  * version 2 of the License, or (at your option) any later version.
9  *
10  * This library is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13  * Library General Public License for more details.
14  *
15  * You should have received a copy of the GNU Library General Public
16  * License along with this library; if not, write to the
17  * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
18  * Boston, MA 02110-1301, USA.
19  */
20 
21 #ifndef __GST_AUDIO_FX_BASE_IIR_FILTER_H__
22 #define __GST_AUDIO_FX_BASE_IIR_FILTER_H__
23 
24 #include <gst/gst.h>
25 #include <gst/base/gstbasetransform.h>
26 #include <gst/audio/audio.h>
27 #include <gst/audio/gstaudiofilter.h>
28 
29 G_BEGIN_DECLS
30 
31 #define GST_TYPE_AUDIO_FX_BASE_IIR_FILTER            (gst_audio_fx_base_iir_filter_get_type())
32 #define GST_AUDIO_FX_BASE_IIR_FILTER(obj)            (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_AUDIO_FX_BASE_IIR_FILTER,GstAudioFXBaseIIRFilter))
33 #define GST_IS_AUDIO_FX_BASE_IIR_FILTER(obj)         (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_AUDIO_FX_BASE_IIR_FILTER))
34 #define GST_AUDIO_FX_BASE_IIR_FILTER_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST((klass) ,GST_TYPE_AUDIO_FX_BASE_IIR_FILTER,GstAudioFXBaseIIRFilterClass))
35 #define GST_IS_AUDIO_FX_BASE_IIR_FILTER_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE((klass) ,GST_TYPE_AUDIO_FX_BASE_IIR_FILTER))
36 #define GST_AUDIO_FX_BASE_IIR_FILTER_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS((obj) ,GST_TYPE_AUDIO_FX_BASE_IIR_FILTER,GstAudioFXBaseIIRFilterClass))
37 typedef struct _GstAudioFXBaseIIRFilter GstAudioFXBaseIIRFilter;
38 typedef struct _GstAudioFXBaseIIRFilterClass GstAudioFXBaseIIRFilterClass;
39 
40 typedef void (*GstAudioFXBaseIIRFilterProcessFunc) (GstAudioFXBaseIIRFilter *, guint8 *, guint);
41 
42 typedef struct
43 {
44   gdouble *x;
45   gint x_pos;
46   gdouble *y;
47   gint y_pos;
48 } GstAudioFXBaseIIRFilterChannelCtx;
49 
50 struct _GstAudioFXBaseIIRFilter
51 {
52   GstAudioFilter audiofilter;
53 
54   /* < private > */
55   GstAudioFXBaseIIRFilterProcessFunc process;
56 
57   gdouble *a;
58   guint na;
59   gdouble *b;
60   guint nb;
61   GstAudioFXBaseIIRFilterChannelCtx *channels;
62   guint nchannels;
63 
64   GMutex lock;
65 };
66 
67 struct _GstAudioFXBaseIIRFilterClass
68 {
69   GstAudioFilterClass parent;
70 };
71 
72 GType gst_audio_fx_base_iir_filter_get_type (void);
73 void gst_audio_fx_base_iir_filter_set_coefficients (GstAudioFXBaseIIRFilter *filter, gdouble *a, guint na, gdouble *b, guint nb);
74 gdouble gst_audio_fx_base_iir_filter_calculate_gain (gdouble *a, guint na, gdouble *b, guint nb, gdouble zr, gdouble zi);
75 
76 G_END_DECLS
77 
78 #endif /* __GST_AUDIO_FX_BASE_IIR_FILTER_H__ */
79