--- /dev/null
+/* GStreamer
+ * Copyright (C) 2011 Tiago Katcipis <tiagokatcipis@gmail.com>
+ * Copyright (C) 2011 Paulo Pizarro <paulo.pizarro@gmail.com>
+ *
+ * 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-removesilence
+ *
+ * Removes all silence periods from an audio stream, dropping silence buffers.
+ *
+ * <refsect2>
+ * <title>Example launch line</title>
+ * |[
+ * gst-launch -v -m filesrc location="audiofile" ! decodebin2 ! removesilence remove=true ! wavenc ! filesink location=without_audio.wav
+ * ]|
+ * </refsect2>
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <gst/gst.h>
+#include <gst/base/gstbasetransform.h>
+#include <gst/controller/gstcontroller.h>
+
+#include "gstremovesilence.h"
+
+
+GST_DEBUG_CATEGORY_STATIC (gst_remove_silence_debug);
+#define GST_CAT_DEFAULT gst_remove_silence_debug
+#define DEFAULT_VAD_HYSTERESIS 480 /* 60 mseg */
+
+/* Filter signals and args */
+enum
+{
+ /* FILL ME */
+ LAST_SIGNAL
+};
+
+enum
+{
+ PROP_0,
+ PROP_REMOVE,
+ PROP_HYSTERESIS
+};
+
+
+static GstStaticPadTemplate sink_template = GST_STATIC_PAD_TEMPLATE ("sink",
+ GST_PAD_SINK,
+ GST_PAD_ALWAYS,
+ GST_STATIC_CAPS
+ ("audio/x-raw-int, "
+ "rate=[1, MAX], channels=1, endianness=BYTE_ORDER, "
+ "width=16, depth=16, signed=true"));
+
+static GstStaticPadTemplate src_template = GST_STATIC_PAD_TEMPLATE ("src",
+ GST_PAD_SRC,
+ GST_PAD_ALWAYS,
+ GST_STATIC_CAPS
+ ("audio/x-raw-int, "
+ "rate=[1, MAX], channels=1, endianness=BYTE_ORDER, "
+ "width=16, depth=16, signed=true"));
+
+
+#define DEBUG_INIT(bla) \
+ GST_DEBUG_CATEGORY_INIT (gst_remove_silence_debug, "removesilence", 0, "removesilence element")
+
+GST_BOILERPLATE_FULL (GstRemoveSilence, gst_remove_silence, GstBaseTransform,
+ GST_TYPE_BASE_TRANSFORM, DEBUG_INIT);
+
+
+static void gst_remove_silence_set_property (GObject * object, guint prop_id,
+ const GValue * value, GParamSpec * pspec);
+static void gst_remove_silence_get_property (GObject * object, guint prop_id,
+ GValue * value, GParamSpec * pspec);
+
+static GstFlowReturn gst_remove_silence_transform_ip (GstBaseTransform * base,
+ GstBuffer * buf);
+static void gst_remove_silence_finalize (GObject * obj);
+static void gst_remove_silence_reset (GstRemoveSilence * filter);
+
+/* GObject vmethod implementations */
+
+static void
+gst_remove_silence_base_init (gpointer gclass)
+{
+ GstElementClass *element_class = GST_ELEMENT_CLASS (gclass);
+
+ gst_element_class_set_details_simple (element_class,
+ "RemoveSilence",
+ "Filter/Effect/Audio",
+ "Removes all the silence periods from the audio stream.",
+ "Tiago Katcipis <tiagokatcipis@gmail.com>\n \
+ Paulo Pizarro <paulo.pizarro@gmail.com>");
+
+ gst_element_class_add_pad_template (element_class,
+ gst_static_pad_template_get (&src_template));
+ gst_element_class_add_pad_template (element_class,
+ gst_static_pad_template_get (&sink_template));
+}
+
+/* initialize the removesilence's class */
+static void
+gst_remove_silence_class_init (GstRemoveSilenceClass * klass)
+{
+ GObjectClass *gobject_class;
+
+ gobject_class = (GObjectClass *) klass;
+ gobject_class->finalize = gst_remove_silence_finalize;
+ gobject_class->set_property = gst_remove_silence_set_property;
+ gobject_class->get_property = gst_remove_silence_get_property;
+
+ g_object_class_install_property (gobject_class, PROP_REMOVE,
+ g_param_spec_boolean ("remove", "Remove",
+ "Set to true to remove silence from the stream, false otherwhise",
+ FALSE, G_PARAM_READWRITE));
+
+ g_object_class_install_property (gobject_class, PROP_HYSTERESIS,
+ g_param_spec_uint64 ("hysteresis",
+ "Hysteresis",
+ "Set the hysteresis (on samples) used on the internal VAD",
+ 1, G_MAXUINT64, DEFAULT_VAD_HYSTERESIS, G_PARAM_READWRITE));
+
+
+ GST_BASE_TRANSFORM_CLASS (klass)->transform_ip =
+ GST_DEBUG_FUNCPTR (gst_remove_silence_transform_ip);
+}
+
+/* initialize the new element
+ * instantiate pads and add them to element
+ * set pad calback functions
+ * initialize instance structure
+ */
+static void
+gst_remove_silence_init (GstRemoveSilence * filter,
+ GstRemoveSilenceClass * gclass)
+{
+ filter->vad = vad_new (DEFAULT_VAD_HYSTERESIS);
+ filter->remove = FALSE;
+
+ if (!filter->vad) {
+ GST_DEBUG ("Error initializing VAD !!");
+ return;
+ }
+
+ gst_remove_silence_reset (filter);
+}
+
+static void
+gst_remove_silence_reset (GstRemoveSilence * filter)
+{
+ GST_DEBUG ("Reseting VAD");
+ if (filter->vad) {
+ vad_reset (filter->vad);
+ }
+ GST_DEBUG ("VAD Reseted");
+}
+
+static void
+gst_remove_silence_finalize (GObject * obj)
+{
+ GstRemoveSilence *filter = GST_REMOVE_SILENCE (obj);
+ GST_DEBUG ("Destroying VAD");
+ vad_destroy (filter->vad);
+ filter->vad = NULL;
+ GST_DEBUG ("VAD Destroyed");
+ G_OBJECT_CLASS (parent_class)->finalize (obj);
+}
+
+static void
+gst_remove_silence_set_property (GObject * object, guint prop_id,
+ const GValue * value, GParamSpec * pspec)
+{
+ GstRemoveSilence *filter = GST_REMOVE_SILENCE (object);
+
+ switch (prop_id) {
+ case PROP_REMOVE:
+ filter->remove = g_value_get_boolean (value);
+ break;
+ case PROP_HYSTERESIS:
+ vad_set_hysteresis (filter->vad, g_value_get_uint64 (value));
+ break;
+ default:
+ G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+ break;
+ }
+}
+
+static void
+gst_remove_silence_get_property (GObject * object, guint prop_id,
+ GValue * value, GParamSpec * pspec)
+{
+ GstRemoveSilence *filter = GST_REMOVE_SILENCE (object);
+
+ switch (prop_id) {
+ case PROP_REMOVE:
+ g_value_set_boolean (value, filter->remove);
+ break;
+ case PROP_HYSTERESIS:
+ g_value_set_uint64 (value, vad_get_hysteresis (filter->vad));
+ break;
+ default:
+ G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+ break;
+ }
+}
+
+static GstFlowReturn
+gst_remove_silence_transform_ip (GstBaseTransform * trans, GstBuffer * inbuf)
+{
+ GstRemoveSilence *filter = NULL;
+ int frame_type;
+
+ filter = GST_REMOVE_SILENCE (trans);
+
+ frame_type =
+ vad_update (filter->vad, (gint16 *) GST_BUFFER_DATA (inbuf),
+ GST_BUFFER_SIZE (inbuf) / sizeof (gint16));
+
+ if (frame_type == VAD_SILENCE) {
+
+ GST_DEBUG ("Silence detected");
+
+ if (filter->remove) {
+ GST_DEBUG ("Removing silence");
+ return GST_BASE_TRANSFORM_FLOW_DROPPED;
+ }
+
+ }
+
+ return GST_FLOW_OK;
+}
+
+/*Plugin init functions*/
+static gboolean
+plugin_init (GstPlugin * plugin)
+{
+ return gst_element_register (plugin, "removesilence", GST_RANK_NONE,
+ gst_remove_silence_get_type ());
+}
+
+GST_PLUGIN_DEFINE (GST_VERSION_MAJOR,
+ GST_VERSION_MINOR,
+ "removesilence",
+ "Removes silence from an audio stream",
+ plugin_init, VERSION, "LGPL", GST_PACKAGE_NAME, GST_PACKAGE_ORIGIN);
--- /dev/null
+/* GStreamer
+ * Copyright (C) 2011 Tiago Katcipis <tiagokatcipis@gmail.com>
+ * Copyright (C) 2011 Paulo Pizarro <paulo.pizarro@gmail.com>
+ *
+ *
+ * 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.
+ */
+
+#ifndef __GST_REMOVE_SILENCE_H__
+#define __GST_REMOVE_SILENCE_H__
+
+#include <gst/gst.h>
+#include <gst/base/gstbasetransform.h>
+#include "vad_private.h"
+
+G_BEGIN_DECLS
+
+#define GST_TYPE_REMOVE_SILENCE \
+ (gst_remove_silence_get_type())
+#define GST_REMOVE_SILENCE(obj) \
+ (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_REMOVE_SILENCE,GstRemoveSilence))
+#define GST_REMOVE_SILENCE_CLASS(klass) \
+ (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_REMOVE_SILENCE,GstRemoveSilenceClass))
+#define GST_IS_REMOVESILENCE(obj) \
+ (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_REMOVE_SILENCE))
+#define GST_IS_REMOVESILENCE_CLASS(klass) \
+ (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_REMOVE_SILENCE))
+
+typedef struct _GstRemoveSilence {
+ GstBaseTransform parent;
+ VADFilter* vad;
+ gboolean remove;
+} GstRemoveSilence;
+
+typedef struct _GstRemoveSilenceClass {
+ GstBaseTransformClass parent_class;
+} GstRemoveSilenceClass;
+
+GType gst_remove_silence_get_type (void);
+
+G_END_DECLS
+
+#endif /* __GST_REMOVE_SILENCE_H__ */
--- /dev/null
+/* GStreamer
+ * Copyright (C) 2009 Tiago Katcipis <tiagokatcipis@gmail.com>
+ * Copyright (C) 2009 Paulo Pizarro <paulo.pizarro@gmail.com>
+ * Copyright (C) 2009 Rogério Santos <rogerio.santos@digitro.com.br>
+ *
+ * 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 <string.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <glib.h>
+#include "vad_private.h"
+
+#define VAD_POWER_ALPHA 0x0800 /* Q16 */
+#define VAD_POWER_THRESHOLD 0x000010C7 /* -60 dB (square wave) */
+#define VAD_ZCR_THRESHOLD 0
+#define VAD_BUFFER_SIZE 256
+
+
+union pgen
+{
+ guint64 a;
+ gpointer v;
+ guint64 *l;
+ guchar *b;
+ guint16 *w;
+ gint16 *s;
+};
+
+struct _cqueue_s
+{
+ union pgen base;
+ union pgen tail;
+ union pgen head;
+ gint size;
+};
+
+typedef struct _cqueue_s cqueue_t;
+
+struct _vad_s
+{
+ gint16 vad_buffer[VAD_BUFFER_SIZE];
+ cqueue_t cqueue;
+ gint vad_state;
+ guint64 hysteresis;
+ guint64 vad_samples;
+ guint64 vad_power;
+ long vad_zcr;
+};
+
+VADFilter *
+vad_new (guint64 hysteresis)
+{
+ VADFilter *vad = malloc (sizeof (VADFilter));
+ vad_reset (vad);
+ vad->hysteresis = hysteresis;
+ return vad;
+}
+
+void
+vad_reset (VADFilter * vad)
+{
+ memset (vad, 0, sizeof (vad));
+ vad->cqueue.base.s = vad->vad_buffer;
+ vad->cqueue.tail.a = vad->cqueue.head.a = 0;
+ vad->cqueue.size = VAD_BUFFER_SIZE;
+ vad->vad_state = VAD_SILENCE;
+}
+
+void
+vad_destroy (VADFilter * p)
+{
+ free (p);
+}
+
+void
+vad_set_hysteresis (struct _vad_s *p, guint64 hysteresis)
+{
+ p->hysteresis = hysteresis;
+}
+
+guint64
+vad_get_hysteresis (struct _vad_s *p)
+{
+ return p->hysteresis;
+}
+
+gint
+vad_update (struct _vad_s * p, gint16 * data, gint len)
+{
+ guint64 tail;
+ gint frame_type;
+ gint16 sample;
+ gint i;
+
+ for (i = 0; i < len; i++) {
+ p->vad_power = VAD_POWER_ALPHA * ((data[i] * data[i] >> 14) & 0xFFFF) +
+ (0xFFFF - VAD_POWER_ALPHA) * (p->vad_power >> 16) +
+ ((0xFFFF - VAD_POWER_ALPHA) * (p->vad_power & 0xFFFF) >> 16);
+ /* Update VAD buffer */
+ p->cqueue.base.s[p->cqueue.head.a] = data[i];
+ p->cqueue.head.a = (p->cqueue.head.a + 1) & (p->cqueue.size - 1);
+ if (p->cqueue.head.a == p->cqueue.tail.a)
+ p->cqueue.tail.a = (p->cqueue.tail.a + 1) & (p->cqueue.size - 1);
+ }
+
+ tail = p->cqueue.tail.a;
+ p->vad_zcr = 0;
+ for (;;) {
+ sample = p->cqueue.base.s[tail];
+ tail = (tail + 1) & (p->cqueue.size - 1);
+ if (tail == p->cqueue.head.a)
+ break;
+ p->vad_zcr +=
+ ((sample & 0x8000) != (p->cqueue.base.s[tail] & 0x8000)) ? 1 : -1;
+ }
+
+ frame_type = (p->vad_power > VAD_POWER_THRESHOLD
+ && p->vad_zcr < VAD_ZCR_THRESHOLD) ? VAD_VOICE : VAD_SILENCE;
+
+ if (p->vad_state != frame_type) {
+ /* Voice to silence transition */
+ if (p->vad_state == VAD_VOICE) {
+ p->vad_samples += len;
+ if (p->vad_samples >= p->hysteresis) {
+ p->vad_state = frame_type;
+ p->vad_samples = 0;
+ }
+ } else {
+ p->vad_state = frame_type;
+ p->vad_samples = 0;
+ }
+ } else {
+ p->vad_samples = 0;
+ }
+
+ return p->vad_state;
+}
--- /dev/null
+/* GStreamer
+ * Copyright (C) 2009 Tiago Katcipis <tiagokatcipis@gmail.com>
+ * Copyright (C) 2009 Paulo Pizarro <paulo.pizarro@gmail.com>
+ * Copyright (C) 2009 Rogério Santos <rogerio.santos@digitro.com.br>
+ *
+ * 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.
+ */
+
+
+#ifndef __VAD_FILTER_H__
+#define __VAD_FILTER_H__
+
+#define VAD_SILENCE 0
+#define VAD_VOICE 1
+
+
+typedef struct _vad_s VADFilter;
+
+gint vad_update(VADFilter *p, gint16 *data, gint len);
+
+void vad_set_hysteresis(VADFilter *p, guint64 hysteresis);
+
+guint64 vad_get_hysteresis(VADFilter *p);
+
+VADFilter* vad_new(guint64 hysteresis);
+
+void vad_reset(VADFilter *p);
+
+void vad_destroy(VADFilter *p);
+
+#endif /* __VAD_FILTER__ */