--- /dev/null
+/* -*- 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_bpwsinc_details = {
+ "BPWSinc",
+ "Filter/Audio/Effect",
+ "Band-Pass Windowed sinc filter",
+ VERSION,
+ "Thomas <thomas@apestaart.org>",
+ "(C) 2002 Steven W. Smith",
+};
+
+enum {
+ /* FILL ME */
+ LAST_SIGNAL
+};
+
+enum {
+ ARG_0,
+ ARG_LENGTH,
+ ARG_LOWER_FREQUENCY,
+ ARG_UPPER_FREQUENCY,
+};
+
+#define GST_TYPE_BPWSINC \
+ (gst_bpwsinc_get_type())
+#define GST_BPWSINC(obj) \
+ (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_BPWSINC,GstBPWSinc))
+#define GST_BPWSINC_CLASS(klass) \
+ (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_ULAW,GstBPWSinc))
+#define GST_IS_BPWSINC(obj) \
+ (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_BPWSINC))
+#define GST_IS_BPWSINC_CLASS(obj) \
+ (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_BPWSINC))
+
+typedef struct _GstBPWSinc GstBPWSinc;
+typedef struct _GstBPWSincClass GstBPWSincClass;
+
+struct _GstBPWSinc
+{
+ GstElement element;
+
+ GstPad *sinkpad, *srcpad;
+
+ double frequency;
+ double lower_frequency, upper_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 _GstBPWSincClass
+{
+ GstElementClass parent_class;
+};
+
+static void gst_bpwsinc_class_init (GstBPWSincClass * klass);
+static void gst_bpwsinc_init (GstBPWSinc * filter);
+
+static void gst_bpwsinc_set_property (GObject * object, guint prop_id,
+ const GValue * value,
+ GParamSpec * pspec);
+static void gst_bpwsinc_get_property (GObject * object, guint prop_id,
+ GValue * value, GParamSpec * pspec);
+
+static void gst_bpwsinc_chain (GstPad * pad, GstBuffer * buf);
+static GstPadConnectReturn
+ gst_bpwsinc_sink_connect (GstPad * pad, GstCaps * caps);
+
+static GstElementClass *parent_class = NULL;
+/*static guint gst_bpwsinc_signals[LAST_SIGNAL] = { 0 }; */
+
+GType gst_bpwsinc_get_type (void)
+{
+ static GType bpwsinc_type = 0;
+
+ if (!bpwsinc_type) {
+ static const GTypeInfo bpwsinc_info = {
+ sizeof (GstBPWSincClass), NULL, NULL,
+ (GClassInitFunc) gst_bpwsinc_class_init, NULL, NULL,
+ sizeof (GstBPWSinc), 0,
+ (GInstanceInitFunc) gst_bpwsinc_init,
+ };
+
+ bpwsinc_type = g_type_register_static (GST_TYPE_ELEMENT, "GstBPWSinc",
+ &bpwsinc_info, 0);
+ }
+ return bpwsinc_type;
+}
+
+static void
+gst_bpwsinc_class_init (GstBPWSincClass * 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_LOWER_FREQUENCY,
+ g_param_spec_double ("lower-frequency", "Lower Frequency",
+ "Cut-off lower frequency (relative to sample rate)",
+ 0.0, 0.5,
+ 0, G_PARAM_READWRITE));
+ g_object_class_install_property (G_OBJECT_CLASS (klass), ARG_UPPER_FREQUENCY,
+ g_param_spec_double ("upper-frequency", "Upper Frequency",
+ "Cut-off upper 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_bpwsinc_set_property;
+ gobject_class->get_property = gst_bpwsinc_get_property;
+}
+
+static void
+gst_bpwsinc_init (GstBPWSinc * filter)
+{
+ filter->sinkpad = gst_pad_new_from_template (gst_filter_sink_factory (), "sink");
+ gst_pad_set_chain_function (filter->sinkpad, gst_bpwsinc_chain);
+ gst_pad_set_connect_function (filter->sinkpad, gst_bpwsinc_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->lower_frequency = 0.25;
+ filter->upper_frequency = 0.3;
+ filter->kernel = NULL;
+}
+
+static GstPadConnectReturn
+gst_bpwsinc_sink_connect (GstPad * pad, GstCaps * caps)
+{
+ int i = 0;
+ double sum = 0.0;
+ int len = 0;
+ double *kernel_lp, *kernel_hp;
+
+ GstBPWSinc *filter = GST_BPWSINC (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))
+ {
+ len = filter->wing_size;
+ /* fill the lp kernel */
+ GST_DEBUG (GST_CAT_PLUGIN_INFO,
+ "bpwsinc: initializing LP kernel of length %d with cut-off %f",
+ len * 2 + 1, filter->lower_frequency);
+ kernel_lp = (double *) g_malloc (sizeof (double) * (2 * len + 1));
+ for (i = 0; i <= len * 2; ++i)
+ {
+ if (i == len)
+ kernel_lp[i] = 2 * M_PI * filter->lower_frequency;
+ else
+ kernel_lp[i] = sin (2 * M_PI * filter->lower_frequency * (i - len))
+ / (i - len);
+ /* Blackman windowing */
+ kernel_lp[i] *= (0.42 - 0.5 * cos (M_PI * i / len)
+ + 0.08 * cos (2 * M_PI * i / len));
+ }
+
+ /* normalize for unity gain at DC
+ * FIXME: sure this is not supposed to be quadratic ? */
+ sum = 0.0;
+ for (i = 0; i <= len * 2; ++i) sum += kernel_lp[i];
+ for (i = 0; i <= len * 2; ++i) kernel_lp[i] /= sum;
+
+ /* fill the hp kernel */
+ GST_DEBUG (GST_CAT_PLUGIN_INFO,
+ "bpwsinc: initializing HP kernel of length %d with cut-off %f",
+ len * 2 + 1, filter->upper_frequency);
+ kernel_hp = (double *) g_malloc (sizeof (double) * (2 * len + 1));
+ for (i = 0; i <= len * 2; ++i)
+ {
+ if (i == len)
+ kernel_hp[i] = 2 * M_PI * filter->upper_frequency;
+ else
+ kernel_hp[i] = sin (2 * M_PI * filter->upper_frequency * (i - len))
+ / (i - len);
+ /* Blackman windowing */
+ kernel_hp[i] *= (0.42 - 0.5 * cos (M_PI * i / len)
+ + 0.08 * cos (2 * M_PI * i / len));
+ }
+
+ /* normalize for unity gain at DC
+ * FIXME: sure this is not supposed to be quadratic ? */
+ sum = 0.0;
+ for (i = 0; i <= len * 2; ++i) sum += kernel_hp[i];
+ for (i = 0; i <= len * 2; ++i) kernel_hp[i] /= sum;
+
+ /* do spectral inversion to get a HP filter */
+ for (i = 0; i <= len * 2; ++i) kernel_hp[i] = -kernel_hp[i];
+ kernel_hp[len] += 1;
+
+ /* combine the two filters */
+
+ filter->kernel = (double *) g_malloc (sizeof (double) * (2 * len + 1));
+
+ for (i = 0; i <= len * 2; ++i)
+ filter->kernel[i] = kernel_lp[i] + kernel_hp[i];
+
+ /* do spectral inversion to go from band reject to bandpass */
+ for (i = 0; i <= len * 2; ++i) filter->kernel[i] = -filter->kernel[i];
+ filter->kernel[len] += 1;
+
+ /* free the helper kernels */
+ g_free (kernel_lp);
+ g_free (kernel_hp);
+
+ /* 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_bpwsinc_chain (GstPad * pad, GstBuffer * buf)
+{
+ GstBPWSinc *filter;
+ gfloat *src;
+ gfloat *input;
+ gint residue_samples;
+ gint input_samples;
+ gint total_samples;
+ int i, j;
+
+ filter = GST_BPWSINC (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_bpwsinc_set_property (GObject * object, guint prop_id, const GValue * value, GParamSpec * pspec)
+{
+ GstBPWSinc *filter;
+
+ /* it's not null if we got it, but it might not be ours */
+ g_return_if_fail (GST_IS_BPWSINC (object));
+
+ filter = GST_BPWSINC (object);
+
+ switch (prop_id) {
+ case ARG_LENGTH:
+ filter->wing_size = g_value_get_int (value);
+ break;
+ case ARG_LOWER_FREQUENCY:
+ filter->lower_frequency = g_value_get_double (value);
+ break;
+ case ARG_UPPER_FREQUENCY:
+ filter->upper_frequency = g_value_get_double (value);
+ break;
+ default:
+ break;
+ }
+}
+
+static void
+gst_bpwsinc_get_property (GObject * object, guint prop_id, GValue * value, GParamSpec * pspec)
+{
+ GstBPWSinc *filter;
+
+ /* it's not null if we got it, but it might not be ours */
+ g_return_if_fail (GST_IS_BPWSINC (object));
+
+ filter = GST_BPWSINC (object);
+
+ switch (prop_id) {
+ case ARG_LENGTH:
+ g_value_set_int (value, filter->wing_size);
+ break;
+ case ARG_LOWER_FREQUENCY:
+ g_value_set_double (value, filter->lower_frequency);
+ break;
+ case ARG_UPPER_FREQUENCY:
+ g_value_set_double (value, filter->upper_frequency);
+ break;
+ default:
+ G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+ break;
+ }
+}
+
#include <math.h> /* M_PI */
#include <string.h> /* memmove */
-GstElementDetails gst_wsinc_details = {
- "WSinc",
+GstElementDetails gst_lpwsinc_details = {
+ "LPWSinc",
"Filter/Audio/Effect",
- "Windowed sinc filter",
+ "Low-pass Windowed sinc filter",
VERSION,
"Thomas <thomas@apestaart.org>",
"(C) 2002 Steven W. Smith",
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
+#define GST_TYPE_LPWSINC \
+ (gst_lpwsinc_get_type())
+#define GST_LPWSINC(obj) \
+ (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_LPWSINC,GstLPWSinc))
+#define GST_LPWSINC_CLASS(klass) \
+ (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_ULAW,GstLPWSinc))
+#define GST_IS_LPWSINC(obj) \
+ (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_LPWSINC))
+#define GST_IS_LPWSINC_CLASS(obj) \
+ (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_LPWSINC))
+
+typedef struct _GstLPWSinc GstLPWSinc;
+typedef struct _GstLPWSincClass GstLPWSincClass;
+
+struct _GstLPWSinc
{
GstElement element;
double *kernel;
};
-struct _GstWSincClass
+struct _GstLPWSincClass
{
GstElementClass parent_class;
};
-static void gst_wsinc_class_init (GstWSincClass * klass);
-static void gst_wsinc_init (GstWSinc * filter);
+static void gst_lpwsinc_class_init (GstLPWSincClass * klass);
+static void gst_lpwsinc_init (GstLPWSinc * filter);
-static void gst_wsinc_set_property (GObject * object, guint prop_id,
+static void gst_lpwsinc_set_property (GObject * object, guint prop_id,
const GValue * value,
GParamSpec * pspec);
-static void gst_wsinc_get_property (GObject * object, guint prop_id,
+static void gst_lpwsinc_get_property (GObject * object, guint prop_id,
GValue * value, GParamSpec * pspec);
-static void gst_wsinc_chain (GstPad * pad, GstBuffer * buf);
+static void gst_lpwsinc_chain (GstPad * pad, GstBuffer * buf);
static GstPadConnectReturn
- gst_wsinc_sink_connect (GstPad * pad, GstCaps * caps);
+ gst_lpwsinc_sink_connect (GstPad * pad, GstCaps * caps);
static GstElementClass *parent_class = NULL;
-/*static guint gst_wsinc_signals[LAST_SIGNAL] = { 0 }; */
+/*static guint gst_lpwsinc_signals[LAST_SIGNAL] = { 0 }; */
-GType gst_wsinc_get_type (void)
+GType gst_lpwsinc_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,
+ static GType lpwsinc_type = 0;
+
+ if (!lpwsinc_type) {
+ static const GTypeInfo lpwsinc_info = {
+ sizeof (GstLPWSincClass), NULL, NULL,
+ (GClassInitFunc) gst_lpwsinc_class_init, NULL, NULL,
+ sizeof (GstLPWSinc), 0,
+ (GInstanceInitFunc) gst_lpwsinc_init,
};
- wsinc_type = g_type_register_static (GST_TYPE_ELEMENT, "GstWSinc",
- &wsinc_info, 0);
+ lpwsinc_type = g_type_register_static (GST_TYPE_ELEMENT, "GstLPWSinc",
+ &lpwsinc_info, 0);
}
- return wsinc_type;
+ return lpwsinc_type;
}
static void
-gst_wsinc_class_init (GstWSincClass * klass)
+gst_lpwsinc_class_init (GstLPWSincClass * klass)
{
GObjectClass *gobject_class;
GstElementClass *gstelement_class;
1, G_MAXINT,
1, G_PARAM_READWRITE));
- gobject_class->set_property = gst_wsinc_set_property;
- gobject_class->get_property = gst_wsinc_get_property;
+ gobject_class->set_property = gst_lpwsinc_set_property;
+ gobject_class->get_property = gst_lpwsinc_get_property;
}
static void
-gst_wsinc_init (GstWSinc * filter)
+gst_lpwsinc_init (GstLPWSinc * 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_pad_set_chain_function (filter->sinkpad, gst_lpwsinc_chain);
+ gst_pad_set_connect_function (filter->sinkpad, gst_lpwsinc_sink_connect);
gst_element_add_pad (GST_ELEMENT (filter), filter->sinkpad);
filter->srcpad = gst_pad_new_from_template (gst_filter_src_factory (), "src");
}
static GstPadConnectReturn
-gst_wsinc_sink_connect (GstPad * pad, GstCaps * caps)
+gst_lpwsinc_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));
+ GstLPWSinc *filter = GST_LPWSINC (gst_pad_get_parent (pad));
g_assert (GST_IS_PAD (pad));
g_assert (caps != NULL);
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);
+ "lpwsinc: 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)
}
static void
-gst_wsinc_chain (GstPad * pad, GstBuffer * buf)
+gst_lpwsinc_chain (GstPad * pad, GstBuffer * buf)
{
- GstWSinc *filter;
+ GstLPWSinc *filter;
gfloat *src;
gfloat *input;
gint residue_samples;
gint total_samples;
int i, j;
- filter = GST_WSINC (gst_pad_get_parent (pad));
+ filter = GST_LPWSINC (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
}
static void
-gst_wsinc_set_property (GObject * object, guint prop_id, const GValue * value, GParamSpec * pspec)
+gst_lpwsinc_set_property (GObject * object, guint prop_id, const GValue * value, GParamSpec * pspec)
{
- GstWSinc *filter;
+ GstLPWSinc *filter;
/* it's not null if we got it, but it might not be ours */
- g_return_if_fail (GST_IS_WSINC (object));
+ g_return_if_fail (GST_IS_LPWSINC (object));
- filter = GST_WSINC (object);
+ filter = GST_LPWSINC (object);
switch (prop_id) {
case ARG_LENGTH:
}
static void
-gst_wsinc_get_property (GObject * object, guint prop_id, GValue * value, GParamSpec * pspec)
+gst_lpwsinc_get_property (GObject * object, guint prop_id, GValue * value, GParamSpec * pspec)
{
- GstWSinc *filter;
+ GstLPWSinc *filter;
/* it's not null if we got it, but it might not be ours */
- g_return_if_fail (GST_IS_WSINC (object));
+ g_return_if_fail (GST_IS_LPWSINC (object));
- filter = GST_WSINC (object);
+ filter = GST_LPWSINC (object);
switch (prop_id) {
case ARG_LENGTH:
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