3 * Copyright (C) 2009 Sebastian Dröge <sebastian.droege@collabora.co.uk>
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.
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.
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.
23 * SECTION:element-audioiirfilter
25 * audioiirfilter implements a generic audio <ulink url="http://en.wikipedia.org/wiki/Infinite_impulse_response">IIR filter</ulink>. Before usage the
26 * "a" and "b" properties have to be set to the filter coefficients that
29 * The filter coefficients describe the numerator and denominator of the
32 * To change the filter coefficients whenever the sampling rate changes the
33 * "rate-changed" signal can be used. This should be done for most
34 * IIR filters as they're depending on the sampling rate.
37 * <title>Example application</title>
39 * <xi:include xmlns:xi="http://www.w3.org/2003/XInclude" parse="text" href="../../../../tests/examples/audiofx/iirfilter-example.c" />
44 /* FIXME 0.11: suppress warnings for deprecated API such as GValueArray
45 * with newer GLib versions (>= 2.31.0) */
46 #define GLIB_DISABLE_DEPRECATION_WARNINGS
55 #include <gst/audio/gstaudiofilter.h>
57 #include "audioiirfilter.h"
59 #include "gst/glib-compat-private.h"
61 #define GST_CAT_DEFAULT gst_audio_iir_filter_debug
62 GST_DEBUG_CATEGORY_STATIC (GST_CAT_DEFAULT);
77 static guint gst_audio_iir_filter_signals[LAST_SIGNAL] = { 0, };
79 #define gst_audio_iir_filter_parent_class parent_class
80 G_DEFINE_TYPE (GstAudioIIRFilter, gst_audio_iir_filter,
81 GST_TYPE_AUDIO_FX_BASE_IIR_FILTER);
83 static void gst_audio_iir_filter_set_property (GObject * object, guint prop_id,
84 const GValue * value, GParamSpec * pspec);
85 static void gst_audio_iir_filter_get_property (GObject * object, guint prop_id,
86 GValue * value, GParamSpec * pspec);
87 static void gst_audio_iir_filter_finalize (GObject * object);
89 static gboolean gst_audio_iir_filter_setup (GstAudioFilter * base,
90 const GstAudioInfo * info);
93 gst_audio_iir_filter_class_init (GstAudioIIRFilterClass * klass)
95 GObjectClass *gobject_class = (GObjectClass *) klass;
96 GstElementClass *gstelement_class = (GstElementClass *) klass;
97 GstAudioFilterClass *filter_class = (GstAudioFilterClass *) klass;
99 GST_DEBUG_CATEGORY_INIT (gst_audio_iir_filter_debug, "audioiirfilter", 0,
100 "Generic audio IIR filter plugin");
102 gobject_class->set_property = gst_audio_iir_filter_set_property;
103 gobject_class->get_property = gst_audio_iir_filter_get_property;
104 gobject_class->finalize = gst_audio_iir_filter_finalize;
106 g_object_class_install_property (gobject_class, PROP_A,
107 g_param_spec_value_array ("a", "A",
108 "Filter coefficients (denominator of transfer function)",
109 g_param_spec_double ("Coefficient", "Filter Coefficient",
110 "Filter coefficient", -G_MAXDOUBLE, G_MAXDOUBLE, 0.0,
111 G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS),
112 G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
113 g_object_class_install_property (gobject_class, PROP_B,
114 g_param_spec_value_array ("b", "B",
115 "Filter coefficients (numerator of transfer function)",
116 g_param_spec_double ("Coefficient", "Filter Coefficient",
117 "Filter coefficient", -G_MAXDOUBLE, G_MAXDOUBLE, 0.0,
118 G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS),
119 G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
121 filter_class->setup = GST_DEBUG_FUNCPTR (gst_audio_iir_filter_setup);
124 * GstAudioIIRFilter::rate-changed:
125 * @filter: the filter on which the signal is emitted
126 * @rate: the new sampling rate
128 * Will be emitted when the sampling rate changes. The callbacks
129 * will be called from the streaming thread and processing will
130 * stop until the event is handled.
132 gst_audio_iir_filter_signals[SIGNAL_RATE_CHANGED] =
133 g_signal_new ("rate-changed", G_TYPE_FROM_CLASS (klass),
134 G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GstAudioIIRFilterClass, rate_changed),
135 NULL, NULL, NULL, G_TYPE_NONE, 1, G_TYPE_INT);
137 gst_element_class_set_static_metadata (gstelement_class,
138 "Audio IIR filter", "Filter/Effect/Audio",
139 "Generic audio IIR filter with custom filter kernel",
140 "Sebastian Dröge <sebastian.droege@collabora.co.uk>");
144 gst_audio_iir_filter_update_coefficients (GstAudioIIRFilter * self,
145 GValueArray * va, GValueArray * vb)
147 gdouble *a = NULL, *b = NULL;
152 g_value_array_free (self->a);
158 g_value_array_free (self->b);
163 if (self->a && self->a->n_values > 0) {
164 a = g_new (gdouble, self->a->n_values);
166 for (i = 0; i < self->a->n_values; i++) {
167 GValue *v = g_value_array_get_nth (self->a, i);
168 a[i] = g_value_get_double (v);
172 if (self->b && self->b->n_values > 0) {
173 b = g_new (gdouble, self->b->n_values);
174 for (i = 0; i < self->b->n_values; i++) {
175 GValue *v = g_value_array_get_nth (self->b, i);
176 b[i] = g_value_get_double (v);
180 gst_audio_fx_base_iir_filter_set_coefficients (GST_AUDIO_FX_BASE_IIR_FILTER
181 (self), a, (self->a) ? self->a->n_values : 0, b,
182 (self->b) ? self->b->n_values : 0);
186 gst_audio_iir_filter_init (GstAudioIIRFilter * self)
191 a = g_value_array_new (1);
193 g_value_init (&v, G_TYPE_DOUBLE);
194 g_value_set_double (&v, 1.0);
195 g_value_array_append (a, &v);
199 gst_audio_iir_filter_update_coefficients (self, a, b);
201 g_mutex_init (&self->lock);
204 /* GstAudioFilter vmethod implementations */
206 /* get notified of caps and plug in the correct process function */
208 gst_audio_iir_filter_setup (GstAudioFilter * base, const GstAudioInfo * info)
210 GstAudioIIRFilter *self = GST_AUDIO_IIR_FILTER (base);
211 gint new_rate = GST_AUDIO_INFO_RATE (info);
213 if (GST_AUDIO_FILTER_RATE (self) != new_rate) {
214 g_signal_emit (G_OBJECT (self),
215 gst_audio_iir_filter_signals[SIGNAL_RATE_CHANGED], 0, new_rate);
218 return GST_AUDIO_FILTER_CLASS (parent_class)->setup (base, info);
222 gst_audio_iir_filter_finalize (GObject * object)
224 GstAudioIIRFilter *self = GST_AUDIO_IIR_FILTER (object);
226 g_mutex_clear (&self->lock);
229 g_value_array_free (self->a);
232 g_value_array_free (self->b);
235 G_OBJECT_CLASS (parent_class)->finalize (object);
239 gst_audio_iir_filter_set_property (GObject * object, guint prop_id,
240 const GValue * value, GParamSpec * pspec)
242 GstAudioIIRFilter *self = GST_AUDIO_IIR_FILTER (object);
244 g_return_if_fail (GST_IS_AUDIO_IIR_FILTER (self));
248 g_mutex_lock (&self->lock);
249 gst_audio_iir_filter_update_coefficients (self, g_value_dup_boxed (value),
251 g_mutex_unlock (&self->lock);
254 g_mutex_lock (&self->lock);
255 gst_audio_iir_filter_update_coefficients (self, NULL,
256 g_value_dup_boxed (value));
257 g_mutex_unlock (&self->lock);
260 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
266 gst_audio_iir_filter_get_property (GObject * object, guint prop_id,
267 GValue * value, GParamSpec * pspec)
269 GstAudioIIRFilter *self = GST_AUDIO_IIR_FILTER (object);
273 g_value_set_boxed (value, self->a);
276 g_value_set_boxed (value, self->b);
279 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);