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1 /* GStreamer IIR equalizer
2  * Copyright (C) <2004> Benjamin Otte <otte@gnome.org>
3  *               <2007> Stefan Kost <ensonic@users.sf.net>
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_IIR_EQUALIZER__
22 #define __GST_IIR_EQUALIZER__
23 
24 #include <gst/audio/gstaudiofilter.h>
25 
26 void equalizer_element_init (GstPlugin * plugin);
27 
28 GST_ELEMENT_REGISTER_DECLARE (equalizer_nbands);
29 GST_ELEMENT_REGISTER_DECLARE (equalizer_3bands);
30 GST_ELEMENT_REGISTER_DECLARE (equalizer_10bands);
31 
32 typedef struct _GstIirEqualizer GstIirEqualizer;
33 typedef struct _GstIirEqualizerClass GstIirEqualizerClass;
34 typedef struct _GstIirEqualizerBand GstIirEqualizerBand;
35 
36 #define GST_TYPE_IIR_EQUALIZER \
37   (gst_iir_equalizer_get_type())
38 #define GST_IIR_EQUALIZER(obj) \
39   (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_IIR_EQUALIZER,GstIirEqualizer))
40 #define GST_IIR_EQUALIZER_CLASS(klass) \
41   (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_IIR_EQUALIZER,GstIirEqualizerClass))
42 #define GST_IS_IIR_EQUALIZER(obj) \
43   (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_IIR_EQUALIZER))
44 #define GST_IS_IIR_EQUALIZER_CLASS(klass) \
45   (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_IIR_EQUALIZER))
46 
47 #define LOWEST_FREQ (20.0)
48 #define HIGHEST_FREQ (20000.0)
49 
50 typedef void (*ProcessFunc) (GstIirEqualizer * eq, guint8 * data, guint size,
51     guint channels);
52 
53 struct _GstIirEqualizer
54 {
55   GstAudioFilter audiofilter;
56 
57   /*< private >*/
58 
59   GMutex bands_lock;
60   GstIirEqualizerBand **bands;
61 
62   /* properties */
63   guint freq_band_count;
64   /* for each band and channel */
65   gpointer history;
66   guint history_size;
67 
68   gboolean need_new_coefficients;
69 
70   ProcessFunc process;
71 };
72 
73 struct _GstIirEqualizerClass
74 {
75   GstAudioFilterClass audiofilter_class;
76 };
77 
78 extern void gst_iir_equalizer_compute_frequencies (GstIirEqualizer * equ, guint new_count);
79 
80 extern GType gst_iir_equalizer_get_type(void);
81 
82 #endif /* __GST_IIR_EQUALIZER__ */
83