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-rw-r--r--gst/audiofx/audioiirfilter.c291
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diff --git a/gst/audiofx/audioiirfilter.c b/gst/audiofx/audioiirfilter.c
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+/*
+ * GStreamer
+ * Copyright (C) 2009 Sebastian Dröge <sebastian.droege@collabora.co.uk>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ *
+ */
+
+/**
+ * SECTION:element-audioiirfilter
+ * @short_description: Generic audio IIR filter
+ *
+ * <refsect2>
+ * <para>
+ * audioiirfilter implements a generic audio <ulink url="http://en.wikipedia.org/wiki/Infinite_impulse_response">IIR filter</ulink>. Before usage the
+ * "a" and "b" properties have to be set to the filter coefficients that
+ * should be used.
+ * </para>
+ * <para>
+ * The filter coefficients describe the numerator and denominator of the
+ * transfer function.
+ * </para>
+ * <para>
+ * To change the filter coefficients whenever the sampling rate changes the
+ * "rate-changed" signal can be used. This should be done for most
+ * IIR filters as they're depending on the sampling rate.
+ * </para>
+ * <title>Example application</title>
+ * <para>
+ * <include xmlns="http://www.w3.org/2003/XInclude" href="element-iirfilter-example.xml" />
+ * </para>
+ * </refsect2>
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <string.h>
+#include <math.h>
+#include <gst/gst.h>
+#include <gst/audio/gstaudiofilter.h>
+#include <gst/controller/gstcontroller.h>
+
+#include "audioiirfilter.h"
+
+#define GST_CAT_DEFAULT gst_audio_iir_filter_debug
+GST_DEBUG_CATEGORY_STATIC (GST_CAT_DEFAULT);
+
+enum
+{
+ SIGNAL_RATE_CHANGED,
+ LAST_SIGNAL
+};
+
+enum
+{
+ PROP_0,
+ PROP_A,
+ PROP_B
+};
+
+static guint gst_audio_iir_filter_signals[LAST_SIGNAL] = { 0, };
+
+#define DEBUG_INIT(bla) \
+ GST_DEBUG_CATEGORY_INIT (gst_audio_iir_filter_debug, "audioiirfilter", 0, \
+ "Generic audio IIR filter plugin");
+
+GST_BOILERPLATE_FULL (GstAudioIIRFilter, gst_audio_iir_filter, GstAudioFilter,
+ GST_TYPE_AUDIO_FX_BASE_IIR_FILTER, DEBUG_INIT);
+
+static void gst_audio_iir_filter_set_property (GObject * object, guint prop_id,
+ const GValue * value, GParamSpec * pspec);
+static void gst_audio_iir_filter_get_property (GObject * object, guint prop_id,
+ GValue * value, GParamSpec * pspec);
+static void gst_audio_iir_filter_finalize (GObject * object);
+
+static gboolean gst_audio_iir_filter_setup (GstAudioFilter * base,
+ GstRingBufferSpec * format);
+
+/* Element class */
+static void
+gst_audio_iir_filter_base_init (gpointer g_class)
+{
+ GstElementClass *element_class = GST_ELEMENT_CLASS (g_class);
+
+ gst_element_class_set_details_simple (element_class,
+ "Audio IIR filter", "Filter/Effect/Audio",
+ "Generic audio IIR filter with custom filter kernel",
+ "Sebastian Dröge <sebastian.droege@collabora.co.uk>");
+}
+
+static void
+gst_audio_iir_filter_class_init (GstAudioIIRFilterClass * klass)
+{
+ GObjectClass *gobject_class = (GObjectClass *) klass;
+ GstAudioFilterClass *filter_class = (GstAudioFilterClass *) klass;
+
+ gobject_class->set_property = gst_audio_iir_filter_set_property;
+ gobject_class->get_property = gst_audio_iir_filter_get_property;
+ gobject_class->finalize = gst_audio_iir_filter_finalize;
+
+ g_object_class_install_property (gobject_class, PROP_A,
+ g_param_spec_value_array ("a", "A",
+ "Filter coefficients (numerator of transfer function)",
+ g_param_spec_double ("Coefficient", "Filter Coefficient",
+ "Filter coefficient", -G_MAXDOUBLE, G_MAXDOUBLE, 0.0,
+ G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS),
+ G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
+ g_object_class_install_property (gobject_class, PROP_B,
+ g_param_spec_value_array ("b", "B",
+ "Filter coefficients (denominator of transfer function)",
+ g_param_spec_double ("Coefficient", "Filter Coefficient",
+ "Filter coefficient", -G_MAXDOUBLE, G_MAXDOUBLE, 0.0,
+ G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS),
+ G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
+
+ filter_class->setup = GST_DEBUG_FUNCPTR (gst_audio_iir_filter_setup);
+
+ /**
+ * GstAudioIIRFilter::rate-changed:
+ * @filter: the filter on which the signal is emitted
+ * @rate: the new sampling rate
+ *
+ * Will be emitted when the sampling rate changes. The callbacks
+ * will be called from the streaming thread and processing will
+ * stop until the event is handled.
+ */
+ gst_audio_iir_filter_signals[SIGNAL_RATE_CHANGED] =
+ g_signal_new ("rate-changed", G_TYPE_FROM_CLASS (klass),
+ G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GstAudioIIRFilterClass, rate_changed),
+ NULL, NULL, gst_marshal_VOID__INT, G_TYPE_NONE, 1, G_TYPE_INT);
+}
+
+static void
+gst_audio_iir_filter_update_coefficients (GstAudioIIRFilter * self,
+ GValueArray * va, GValueArray * vb)
+{
+ gdouble *a = NULL, *b = NULL;
+ guint i;
+
+ if (va) {
+ if (self->a)
+ g_value_array_free (self->a);
+
+ self->a = va;
+ }
+ if (vb) {
+ if (self->b)
+ g_value_array_free (self->b);
+
+ self->b = vb;
+ }
+
+ if (self->a && self->a->n_values > 0)
+ a = g_new (gdouble, self->a->n_values);
+ if (self->b && self->b->n_values > 0)
+ b = g_new (gdouble, self->b->n_values);
+
+ if (self->a) {
+ for (i = 0; i < self->a->n_values; i++) {
+ GValue *v = g_value_array_get_nth (self->a, i);
+ a[i] = g_value_get_double (v);
+ }
+ }
+
+ if (self->b) {
+ for (i = 0; i < self->b->n_values; i++) {
+ GValue *v = g_value_array_get_nth (self->b, i);
+ b[i] = g_value_get_double (v);
+ }
+ }
+
+ gst_audio_fx_base_iir_filter_set_coefficients (GST_AUDIO_FX_BASE_IIR_FILTER
+ (self), a, (self->a) ? self->a->n_values : 0, b,
+ (self->b) ? self->b->n_values : 0);
+}
+
+static void
+gst_audio_iir_filter_init (GstAudioIIRFilter * self,
+ GstAudioIIRFilterClass * g_class)
+{
+ GValue v = { 0, };
+ GValueArray *a, *b;
+
+ a = g_value_array_new (1);
+
+ g_value_init (&v, G_TYPE_DOUBLE);
+ g_value_set_double (&v, 1.0);
+ g_value_array_append (a, &v);
+ g_value_unset (&v);
+
+ b = NULL;
+ gst_audio_iir_filter_update_coefficients (self, a, b);
+
+ self->lock = g_mutex_new ();
+}
+
+/* GstAudioFilter vmethod implementations */
+
+/* get notified of caps and plug in the correct process function */
+static gboolean
+gst_audio_iir_filter_setup (GstAudioFilter * base, GstRingBufferSpec * format)
+{
+ GstAudioIIRFilter *self = GST_AUDIO_IIR_FILTER (base);
+
+ if (self->rate != format->rate) {
+ g_signal_emit (G_OBJECT (self),
+ gst_audio_iir_filter_signals[SIGNAL_RATE_CHANGED], 0, format->rate);
+ self->rate = format->rate;
+ }
+
+ return GST_AUDIO_FILTER_CLASS (parent_class)->setup (base, format);
+}
+
+static void
+gst_audio_iir_filter_finalize (GObject * object)
+{
+ GstAudioIIRFilter *self = GST_AUDIO_IIR_FILTER (object);
+
+ g_mutex_free (self->lock);
+ self->lock = NULL;
+
+ if (self->a)
+ g_value_array_free (self->a);
+ self->a = NULL;
+ if (self->b)
+ g_value_array_free (self->b);
+ self->b = NULL;
+
+ G_OBJECT_CLASS (parent_class)->finalize (object);
+}
+
+static void
+gst_audio_iir_filter_set_property (GObject * object, guint prop_id,
+ const GValue * value, GParamSpec * pspec)
+{
+ GstAudioIIRFilter *self = GST_AUDIO_IIR_FILTER (object);
+
+ g_return_if_fail (GST_IS_AUDIO_IIR_FILTER (self));
+
+ switch (prop_id) {
+ case PROP_A:
+ g_mutex_lock (self->lock);
+ gst_audio_iir_filter_update_coefficients (self, g_value_dup_boxed (value),
+ NULL);
+ g_mutex_unlock (self->lock);
+ break;
+ case PROP_B:
+ g_mutex_lock (self->lock);
+ gst_audio_iir_filter_update_coefficients (self, NULL,
+ g_value_dup_boxed (value));
+ g_mutex_unlock (self->lock);
+ break;
+ default:
+ G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+ break;
+ }
+}
+
+static void
+gst_audio_iir_filter_get_property (GObject * object, guint prop_id,
+ GValue * value, GParamSpec * pspec)
+{
+ GstAudioIIRFilter *self = GST_AUDIO_IIR_FILTER (object);
+
+ switch (prop_id) {
+ case PROP_A:
+ g_value_set_boxed (value, self->a);
+ break;
+ case PROP_B:
+ g_value_set_boxed (value, self->b);
+ break;
+ default:
+ G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+ break;
+ }
+}
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