new filter subdir for standard audio filters first filter uses code from vorbis to implement an iir filter not optimi...

Original commit message from CVS:
new filter subdir for standard audio filters
first filter uses code from vorbis to implement an iir filter
not optimized yet, iir code uses doubles and plugin uses float

1 files changed, 259 insertions, 0 deletions

diff --git a/gst/filter/gstiir.c b/gst/filter/gstiir.c
new file mode 100644
index 00000000..811b6a12
--- /dev/null
+++ b/gst/filter/gstiir.c
@@ -0,0 +1,259 @@
+/* -*- c-basic-offset: 2 -*-
+ * GStreamer
+ * Copyright (C) 1999-2001 Erik Walthinsen <omega@cse.ogi.edu>
+ *
+ * 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.
+ */
+
+#include <gst/gst.h>
+#include "gstfilter.h"
+#include "iir.h"
+
+GstElementDetails gst_iir_details = {
+  "IIR",
+  "Filter/Audio/Effect",
+  "IIR filter based on vorbis code",
+  VERSION,
+  "Monty <monty@xiph.org>, "\
+  "Thomas <thomas@apestaart.org>",
+  "(C) 2001",
+};
+
+enum {
+  /* FILL ME */
+  LAST_SIGNAL
+};
+
+enum {
+  ARG_0,
+  ARG_A,
+  ARG_B,
+  ARG_GAIN,
+  ARG_STAGES,
+};
+
+#define GST_TYPE_IIR \
+  (gst_iir_get_type())
+#define GST_IIR(obj) \
+      (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_IIR,GstIIR))
+#define GST_IIR_CLASS(klass) \
+      (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_ULAW,GstIIR))
+#define GST_IS_IIR(obj) \
+      (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_IIR))
+#define GST_IS_IIR_CLASS(obj) \
+      (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_IIR))
+
+typedef struct _GstIIR GstIIR;
+typedef struct _GstIIRClass GstIIRClass;
+
+struct _GstIIR
+{
+  GstElement element;
+
+  GstPad *sinkpad, *srcpad;
+
+  double A, B;
+  double gain;
+  int stages;
+  IIR_state *state;
+};
+
+struct _GstIIRClass
+{
+    GstElementClass parent_class;
+};
+
+static void gst_iir_class_init		(GstIIRClass * klass);
+static void gst_iir_init               	(GstIIR * filter);
+
+static void gst_iir_set_property	(GObject * object, guint prop_id,
+                                         const GValue * value, 
+					 GParamSpec * pspec);
+static void gst_iir_get_property	(GObject * object, guint prop_id,
+                                         GValue * value, GParamSpec * pspec);
+
+static void gst_iir_chain		(GstPad * pad, GstBuffer * buf);
+static GstPadConnectReturn
+       gst_iir_sink_connect 		(GstPad * pad, GstCaps * caps);
+
+static GstElementClass *parent_class = NULL;
+/*static guint gst_iir_signals[LAST_SIGNAL] = { 0 }; */
+
+GType gst_iir_get_type (void)
+{
+  static GType iir_type = 0;
+
+  if (!iir_type) {
+    static const GTypeInfo iir_info = {
+      sizeof (GstIIRClass), NULL, NULL,
+      (GClassInitFunc) gst_iir_class_init, NULL, NULL,
+      sizeof (GstIIR), 0,
+      (GInstanceInitFunc) gst_iir_init,
+    };
+
+    iir_type = g_type_register_static (GST_TYPE_ELEMENT, "GstIIR", 
+	                                   &iir_info, 0);
+  }
+  return iir_type;
+}
+
+static void
+gst_iir_class_init (GstIIRClass * klass)
+{
+  GObjectClass *gobject_class;
+  GstElementClass *gstelement_class;
+
+  gobject_class = (GObjectClass *) klass;
+  gstelement_class = (GstElementClass *) klass;
+
+  parent_class = g_type_class_ref (GST_TYPE_ELEMENT);
+
+  g_object_class_install_property (G_OBJECT_CLASS (klass), ARG_A,
+      g_param_spec_double ("A", "A", "A filter coefficient", 
+	                   -G_MAXDOUBLE, G_MAXDOUBLE, 
+	                   0, G_PARAM_READWRITE));
+  g_object_class_install_property (G_OBJECT_CLASS (klass), ARG_B,
+      g_param_spec_double ("B", "B", "B filter coefficient", 
+	                   -G_MAXDOUBLE, G_MAXDOUBLE, 
+	                   0, G_PARAM_READWRITE));
+  g_object_class_install_property (G_OBJECT_CLASS (klass), ARG_GAIN,
+      g_param_spec_double ("gain", "Gain", "Filter gain", 
+	                   -G_MAXDOUBLE, G_MAXDOUBLE, 
+	                   0, G_PARAM_READWRITE));
+  g_object_class_install_property (G_OBJECT_CLASS (klass), ARG_STAGES,
+      g_param_spec_int ("stages", "Stages", "Number of filter stages", 
+	                   1, G_MAXINT, 
+	                   0, G_PARAM_READWRITE));
+
+  gobject_class->set_property = gst_iir_set_property;
+  gobject_class->get_property = gst_iir_get_property;
+}
+
+static void
+gst_iir_init (GstIIR * filter)
+{
+  filter->sinkpad = gst_pad_new_from_template (gst_filter_sink_factory (), "sink");
+  gst_pad_set_chain_function (filter->sinkpad, gst_iir_chain);
+  gst_pad_set_connect_function (filter->sinkpad, gst_iir_sink_connect);
+  gst_element_add_pad (GST_ELEMENT (filter), filter->sinkpad);
+
+  filter->srcpad = gst_pad_new_from_template (gst_filter_src_factory (), "src");
+  gst_element_add_pad (GST_ELEMENT (filter), filter->srcpad);
+
+  filter->A = 0.0;
+  filter->B = 0.0;
+  filter->gain = 1.0;	/* unity gain as default */
+  filter->stages = 1;
+  filter->state = NULL;
+}
+
+static GstPadConnectReturn
+gst_iir_sink_connect (GstPad * pad, GstCaps * caps)
+{
+  GstIIR *filter;
+  
+  filter = GST_IIR (gst_pad_get_parent (pad));
+  
+  if (!GST_CAPS_IS_FIXED (caps))
+    return GST_PAD_CONNECT_DELAYED;
+    
+  if (gst_pad_try_set_caps (filter->srcpad, caps)) {
+    /* connection works, so init the filter */
+    /* FIXME: remember to free it */
+    filter->state = (IIR_state *) g_malloc (sizeof (IIR_state));
+    IIR_init (filter->state, filter->stages, 
+	      filter->gain, &(filter->A), &(filter->B));
+    return GST_PAD_CONNECT_OK;
+  }
+
+  return GST_PAD_CONNECT_REFUSED;
+}
+
+static void
+gst_iir_chain (GstPad * pad, GstBuffer * buf)
+{
+  GstIIR *filter;
+  gfloat *src;
+  int i;
+
+  filter = GST_IIR (gst_pad_get_parent (pad));
+
+  src = (gfloat *) GST_BUFFER_DATA (buf);
+
+  /* do an in-place edit */
+  for (i = 0; i < GST_BUFFER_SIZE (buf) / sizeof (gfloat); ++i)
+    *(src + i) = (gfloat) IIR_filter (filter->state, (double) *(src + i));
+
+  gst_pad_push (filter->srcpad, buf);
+}
+
+static void
+gst_iir_set_property (GObject * object, guint prop_id, const GValue * value, GParamSpec * pspec)
+{
+  GstIIR *filter;
+
+  /* it's not null if we got it, but it might not be ours */
+  g_return_if_fail (GST_IS_IIR (object));
+
+  filter = GST_IIR (object);
+
+  switch (prop_id) {
+    case ARG_A:
+     filter->A = g_value_get_double (value);
+     break; 
+    case ARG_B:
+     filter->B = g_value_get_double (value);
+     break; 
+    case ARG_GAIN:
+     filter->gain = g_value_get_double (value);
+     break; 
+    case ARG_STAGES:
+     filter->stages = g_value_get_int (value);
+     break; 
+    default:
+      break;
+  }
+}
+
+static void
+gst_iir_get_property (GObject * object, guint prop_id, GValue * value, GParamSpec * pspec)
+{
+  GstIIR *filter;
+
+  /* it's not null if we got it, but it might not be ours */
+  g_return_if_fail (GST_IS_IIR (object));
+  
+  filter = GST_IIR (object);
+
+  switch (prop_id) {
+    case ARG_A:
+      g_value_set_double (value, filter->A);
+      break;
+    case ARG_B:
+      g_value_set_double (value, filter->B);
+      break;
+    case ARG_GAIN:
+      g_value_set_double (value, filter->gain);
+      break;
+    case ARG_STAGES:
+      g_value_set_int (value, filter->stages);
+      break;
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+  }
+} 
+