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-rw-r--r--gst/filter/Makefile.am2
-rw-r--r--gst/filter/gstfilter.c1
-rw-r--r--gst/filter/gstfilter.h3
-rw-r--r--gst/filter/gstiir.c2
-rw-r--r--gst/filter/gstwsinc.c311
5 files changed, 317 insertions, 2 deletions
diff --git a/gst/filter/Makefile.am b/gst/filter/Makefile.am
index 4204955f..fd11c105 100644
--- a/gst/filter/Makefile.am
+++ b/gst/filter/Makefile.am
@@ -2,7 +2,7 @@ plugindir = $(libdir)/gst
plugin_LTLIBRARIES = libgstfilter.la
-libgstfilter_la_SOURCES = gstfilter.c gstiir.c iir.c
+libgstfilter_la_SOURCES = gstfilter.c gstiir.c iir.c gstwsinc.c
libgstfilter_la_CFLAGS = $(GST_CFLAGS)
libgstfilter_la_LIBADD =
libgstfilter_la_LDFLAGS = $(GST_PLUGIN_LDFLAGS)
diff --git a/gst/filter/gstfilter.c b/gst/filter/gstfilter.c
index 2ed416c1..cd9f466e 100644
--- a/gst/filter/gstfilter.c
+++ b/gst/filter/gstfilter.c
@@ -32,6 +32,7 @@ struct _elements_entry {
static struct _elements_entry _elements[] = {
{ "iir", gst_iir_get_type, &gst_iir_details, NULL },
+ { "wsinc", gst_wsinc_get_type, &gst_wsinc_details, NULL },
{ NULL, 0 },
};
diff --git a/gst/filter/gstfilter.h b/gst/filter/gstfilter.h
index a806bb4d..a23a1440 100644
--- a/gst/filter/gstfilter.h
+++ b/gst/filter/gstfilter.h
@@ -31,4 +31,7 @@ extern GstElementDetails gst_iir_details;
extern GstPadTemplate *gst_filter_sink_factory ();
extern GstPadTemplate *gst_filter_src_factory ();
+GType gst_wsinc_get_type (void);
+extern GstElementDetails gst_wsinc_details;
+
#endif /* __GST_FILTER_H__ */
diff --git a/gst/filter/gstiir.c b/gst/filter/gstiir.c
index 811b6a12..0bbcb050 100644
--- a/gst/filter/gstiir.c
+++ b/gst/filter/gstiir.c
@@ -136,7 +136,7 @@ gst_iir_class_init (GstIIRClass * klass)
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));
+ 1, G_PARAM_READWRITE));
gobject_class->set_property = gst_iir_set_property;
gobject_class->get_property = gst_iir_get_property;
diff --git a/gst/filter/gstwsinc.c b/gst/filter/gstwsinc.c
new file mode 100644
index 00000000..19300456
--- /dev/null
+++ b/gst/filter/gstwsinc.c
@@ -0,0 +1,311 @@
+/* -*- 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.
+ */
+
+/* this windowed sinc filter is taken from the freely downloadable DSP book,
+ * "The Scientist and Engineer's Guide to Digital Signal Processing",
+ * chapter 16
+ * available at http://www.dspguide.com/
+ */
+
+/* FIXME:
+ * - this filter is totally unoptimized !
+ * - we do not destroy the allocated memory for filters and residue
+ * - this might be improved upon with bytestream
+ */
+
+#include <gst/gst.h>
+#include "gstfilter.h"
+#include <math.h> /* M_PI */
+#include <string.h> /* memmove */
+
+GstElementDetails gst_wsinc_details = {
+ "WSinc",
+ "Filter/Audio/Effect",
+ "Windowed sinc filter",
+ VERSION,
+ "Thomas <thomas@apestaart.org>",
+ "(C) 2002 Steven W. Smith",
+};
+
+enum {
+ /* FILL ME */
+ LAST_SIGNAL
+};
+
+enum {
+ ARG_0,
+ ARG_LENGTH,
+ ARG_FREQUENCY,
+};
+
+#define GST_TYPE_WSINC \
+ (gst_wsinc_get_type())
+#define GST_WSINC(obj) \
+ (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_WSINC,GstWSinc))
+#define GST_WSINC_CLASS(klass) \
+ (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_ULAW,GstWSinc))
+#define GST_IS_WSINC(obj) \
+ (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_WSINC))
+#define GST_IS_WSINC_CLASS(obj) \
+ (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_WSINC))
+
+typedef struct _GstWSinc GstWSinc;
+typedef struct _GstWSincClass GstWSincClass;
+
+struct _GstWSinc
+{
+ GstElement element;
+
+ GstPad *sinkpad, *srcpad;
+
+ double frequency;
+ int wing_size; /* length of a "wing" of the filter;
+ actual length is 2 * wing_size + 1 */
+
+ gfloat *residue; /* buffer for left-over samples from previous buffer */
+ double *kernel;
+};
+
+struct _GstWSincClass
+{
+ GstElementClass parent_class;
+};
+
+static void gst_wsinc_class_init (GstWSincClass * klass);
+static void gst_wsinc_init (GstWSinc * filter);
+
+static void gst_wsinc_set_property (GObject * object, guint prop_id,
+ const GValue * value,
+ GParamSpec * pspec);
+static void gst_wsinc_get_property (GObject * object, guint prop_id,
+ GValue * value, GParamSpec * pspec);
+
+static void gst_wsinc_chain (GstPad * pad, GstBuffer * buf);
+static GstPadConnectReturn
+ gst_wsinc_sink_connect (GstPad * pad, GstCaps * caps);
+
+static GstElementClass *parent_class = NULL;
+/*static guint gst_wsinc_signals[LAST_SIGNAL] = { 0 }; */
+
+GType gst_wsinc_get_type (void)
+{
+ static GType wsinc_type = 0;
+
+ if (!wsinc_type) {
+ static const GTypeInfo wsinc_info = {
+ sizeof (GstWSincClass), NULL, NULL,
+ (GClassInitFunc) gst_wsinc_class_init, NULL, NULL,
+ sizeof (GstWSinc), 0,
+ (GInstanceInitFunc) gst_wsinc_init,
+ };
+
+ wsinc_type = g_type_register_static (GST_TYPE_ELEMENT, "GstWSinc",
+ &wsinc_info, 0);
+ }
+ return wsinc_type;
+}
+
+static void
+gst_wsinc_class_init (GstWSincClass * 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_FREQUENCY,
+ g_param_spec_double ("frequency", "Frequency",
+ "Cut-off Frequency relative to sample rate)",
+ 0.0, 0.5,
+ 0, G_PARAM_READWRITE));
+ g_object_class_install_property (G_OBJECT_CLASS (klass), ARG_LENGTH,
+ g_param_spec_int ("length", "Length",
+ "N such that the filter length = 2N + 1",
+ 1, G_MAXINT,
+ 1, G_PARAM_READWRITE));
+
+ gobject_class->set_property = gst_wsinc_set_property;
+ gobject_class->get_property = gst_wsinc_get_property;
+}
+
+static void
+gst_wsinc_init (GstWSinc * filter)
+{
+ filter->sinkpad = gst_pad_new_from_template (gst_filter_sink_factory (), "sink");
+ gst_pad_set_chain_function (filter->sinkpad, gst_wsinc_chain);
+ gst_pad_set_connect_function (filter->sinkpad, gst_wsinc_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->wing_size = 50;
+ filter->frequency = 0.25;
+ filter->kernel = NULL;
+}
+
+static GstPadConnectReturn
+gst_wsinc_sink_connect (GstPad * pad, GstCaps * caps)
+{
+ int i = 0;
+ double sum = 0.0;
+ int len = 0;
+ GstWSinc *filter = GST_WSINC (gst_pad_get_parent (pad));
+
+ g_assert (GST_IS_PAD (pad));
+ g_assert (caps != NULL);
+
+ 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 */
+ /* fill the kernel */
+ g_print ("DEBUG: initing filter kernel\n");
+ len = filter->wing_size;
+ GST_DEBUG (GST_CAT_PLUGIN_INFO,
+ "wsinc: initializing filter kernel of length %d", len * 2 + 1);
+ filter->kernel = (double *) g_malloc (sizeof (double) * (2 * len + 1));
+
+ for (i = 0; i <= len * 2; ++i)
+ {
+ if (i == len)
+ filter->kernel[i] = 2 * M_PI * filter->frequency;
+ else
+ filter->kernel[i] = sin (2 * M_PI * filter->frequency * (i - len))
+ / (i - len);
+ /* windowing */
+ filter->kernel[i] *= (0.54 - 0.46 * cos (M_PI * i / len));
+ }
+
+ /* normalize for unity gain at DC
+ * FIXME: sure this is not supposed to be quadratic ? */
+ for (i = 0; i <= len * 2; ++i) sum += filter->kernel[i];
+ for (i = 0; i <= len * 2; ++i) filter->kernel[i] /= sum;
+
+ /* set up the residue memory space */
+ filter->residue = (gfloat *) g_malloc (sizeof (gfloat) * (len * 2 + 1));
+ for (i = 0; i <= len * 2; ++i) filter->residue[i] = 0.0;
+
+ return GST_PAD_CONNECT_OK;
+ }
+
+ return GST_PAD_CONNECT_REFUSED;
+}
+
+static void
+gst_wsinc_chain (GstPad * pad, GstBuffer * buf)
+{
+ GstWSinc *filter;
+ gfloat *src;
+ gfloat *input;
+ gint residue_samples;
+ gint input_samples;
+ gint total_samples;
+ int i, j;
+
+ filter = GST_WSINC (gst_pad_get_parent (pad));
+
+ /* FIXME: out of laziness, we copy the left-over bit from last buffer
+ * together with the incoming buffer to a new buffer to make the loop
+ * easy; this could be a lot more optimized though
+ * to make amends we keep the incoming buffer around and write our
+ * output samples there */
+
+ src = (gfloat *) GST_BUFFER_DATA (buf);
+ residue_samples = filter->wing_size * 2 + 1;
+ input_samples = GST_BUFFER_SIZE (buf) / sizeof (gfloat);
+ total_samples = residue_samples + input_samples;
+
+ input = (gfloat *) g_malloc (sizeof (gfloat) * total_samples);
+
+ /* copy the left-over bit */
+ memcpy (input, filter->residue, sizeof (gfloat) * residue_samples);
+
+ /* copy the new buffer */
+ memcpy (&input[residue_samples], src, sizeof (gfloat) * input_samples);
+ /* copy the tail of the current input buffer to the residue */
+ memcpy (filter->residue, &src[input_samples - residue_samples],
+ sizeof (gfloat) * residue_samples);
+
+ /* convolution */
+ /* since we copied the previous set of samples we needed before the actual
+ * input data, we need to add the filter length to our indices for input */
+ for (i = 0; i < input_samples; ++i)
+ {
+ src[i] = 0.0;
+ for (j = 0; j < residue_samples; ++j)
+ src[i] += input[i - j + residue_samples] * filter->kernel[j];
+ }
+
+ g_free (input);
+ gst_pad_push (filter->srcpad, buf);
+}
+
+static void
+gst_wsinc_set_property (GObject * object, guint prop_id, const GValue * value, GParamSpec * pspec)
+{
+ GstWSinc *filter;
+
+ /* it's not null if we got it, but it might not be ours */
+ g_return_if_fail (GST_IS_WSINC (object));
+
+ filter = GST_WSINC (object);
+
+ switch (prop_id) {
+ case ARG_LENGTH:
+ filter->wing_size = g_value_get_int (value);
+ break;
+ case ARG_FREQUENCY:
+ filter->frequency = g_value_get_double (value);
+ break;
+ default:
+ break;
+ }
+}
+
+static void
+gst_wsinc_get_property (GObject * object, guint prop_id, GValue * value, GParamSpec * pspec)
+{
+ GstWSinc *filter;
+
+ /* it's not null if we got it, but it might not be ours */
+ g_return_if_fail (GST_IS_WSINC (object));
+
+ filter = GST_WSINC (object);
+
+ switch (prop_id) {
+ case ARG_LENGTH:
+ g_value_set_int (value, filter->wing_size);
+ break;
+ case ARG_FREQUENCY:
+ g_value_set_double (value, filter->frequency);
+ break;
+ default:
+ G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+ break;
+ }
+}
+
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