- Added generic shaper element that keeps two streams in sync.

Original commit message from CVS:
- Added generic shaper element that keeps two streams in sync.

gst/elements/Makefile.am

@@ -16,6 +16,7 @@ libgstelements_la_SOURCES =	\
 	gstpipefilter.c		\
 	gsttee.c		\
 	gstaggregator.c		\
+	gstshaper.c		\
 	gststatistics.c		\
 	gstmd5sink.c
 libgstelements_la_CFLAGS = $(GST_CFLAGS)
@@ -33,6 +34,7 @@ noinst_HEADERS =		\
 	gstpipefilter.h		\
 	gsttee.h		\
 	gstaggregator.h		\
+	gstshaper.h		\
 	gststatistics.h	        \
 	gstfilesrc.h		\
 	gstmd5sink.h

gst/elements/gstelements.c

@@ -33,6 +33,7 @@
 #include "gstpipefilter.h"
 #include "gsttee.h"
 #include "gstaggregator.h"
+#include "gstshaper.h"
 #include "gststatistics.h"
 #include "gstmd5sink.h"
 
@@ -60,6 +61,7 @@ static struct _elements_entry _elements[] = {
   { "pipefilter",   gst_pipefilter_get_type, 	&gst_pipefilter_details,	NULL },
   { "tee",     	    gst_tee_get_type, 		&gst_tee_details,		gst_tee_factory_init },
   { "aggregator",   gst_aggregator_get_type, 	&gst_aggregator_details,	gst_aggregator_factory_init },
+  { "shaper",       gst_shaper_get_type, 	&gst_shaper_details,		gst_shaper_factory_init },
   { "statistics",   gst_statistics_get_type, 	&gst_statistics_details,	NULL },
   { "md5sink",      gst_md5sink_get_type, 	&gst_md5sink_details,		gst_md5sink_factory_init },
   { NULL, 0 },

gst/elements/gstshaper.c

@@ -0,0 +1,383 @@
+/* GStreamer
+ * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
+ *                    2000 Wim Taymans <wtay@chello.be>
+ *
+ * gstshaper.c: 
+ *
+ * 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 <stdlib.h>
+#include <gstshaper.h>
+
+GstElementDetails gst_shaper_details = {
+  "Shaper",
+  "Generic",
+  "LGPL",
+  "Synchronizes streams on different pads",
+  VERSION,
+  "Wim Taymans <wim.taymans@chello.be>",
+  "(C) 2003",
+};
+
+
+/* Shaper signals and args */
+enum {
+  /* FILL ME */
+  LAST_SIGNAL
+};
+
+enum {
+  ARG_0,
+  ARG_POLICY,
+  ARG_SILENT,
+  ARG_LAST_MESSAGE,
+};
+
+typedef struct
+{
+  GstPad 	*sinkpad;
+  GstPad 	*srcpad;
+  GstBuffer	*buffer;
+} GstShaperConnection;
+
+GST_PAD_TEMPLATE_FACTORY (shaper_src_factory,
+  "src%d",
+  GST_PAD_SRC,
+  GST_PAD_SOMETIMES,
+  NULL                  /* no caps */
+);
+
+GST_PAD_TEMPLATE_FACTORY (shaper_sink_factory,
+  "sink%d",
+  GST_PAD_SINK,
+  GST_PAD_REQUEST,
+  NULL                  /* no caps */
+);
+
+#define GST_TYPE_SHAPER_POLICY (gst_shaper_policy_get_type())
+static GType
+gst_shaper_policy_get_type (void)
+{
+  static GType shaper_policy_type = 0;
+  static GEnumValue shaper_policy[] = {
+    { SHAPER_POLICY_TIMESTAMPS,         "1", "sync on timestamps"},
+    { SHAPER_POLICY_BUFFERSIZE,         "2", "sync on buffer size"},
+    {0, NULL, NULL},
+  };
+  if (!shaper_policy_type) {
+    shaper_policy_type = g_enum_register_static ("GstShaperPolicy", shaper_policy);
+  }
+  return shaper_policy_type;
+}
+
+static void 	gst_shaper_class_init		(GstShaperClass *klass);
+static void 	gst_shaper_init			(GstShaper *shaper);
+
+static void 	gst_shaper_set_property		(GObject *object, guint prop_id, 
+						 const GValue *value, GParamSpec *pspec);
+static void 	gst_shaper_get_property		(GObject *object, guint prop_id, 
+						 GValue *value, GParamSpec *pspec);
+
+static GstPad* 	gst_shaper_request_new_pad 	(GstElement *element, GstPadTemplate *templ, 
+						 const gchar *unused);
+
+static void 	gst_shaper_loop			(GstElement *element);
+
+static GstElementClass *parent_class = NULL;
+/* static guint gst_shaper_signals[LAST_SIGNAL] = { 0 }; */
+
+GType
+gst_shaper_get_type (void) 
+{
+  static GType shaper_type = 0;
+
+  if (!shaper_type) {
+    static const GTypeInfo shaper_info = {
+      sizeof(GstShaperClass),      NULL,
+      NULL,
+      (GClassInitFunc)gst_shaper_class_init,
+      NULL,
+      NULL,
+      sizeof(GstShaper),
+      0,
+      (GInstanceInitFunc)gst_shaper_init,
+    };
+    shaper_type = g_type_register_static (GST_TYPE_ELEMENT, "GstShaper", &shaper_info, 0);
+  }
+  return shaper_type;
+}
+
+static void 
+gst_shaper_class_init (GstShaperClass *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_POLICY,
+    g_param_spec_enum ("policy", "Policy", "Shaper policy",
+                       GST_TYPE_SHAPER_POLICY, SHAPER_POLICY_TIMESTAMPS, G_PARAM_READWRITE));
+  g_object_class_install_property (G_OBJECT_CLASS (klass), ARG_SILENT,
+    g_param_spec_boolean ("silent", "silent", "silent",
+                          FALSE, G_PARAM_READWRITE)); 
+  g_object_class_install_property (G_OBJECT_CLASS (klass), ARG_LAST_MESSAGE,
+    g_param_spec_string ("last-message", "last-message", "last-message",
+                         NULL, G_PARAM_READABLE)); 
+
+  gobject_class->set_property = GST_DEBUG_FUNCPTR (gst_shaper_set_property);  
+  gobject_class->get_property = GST_DEBUG_FUNCPTR (gst_shaper_get_property);
+
+  gstelement_class->request_new_pad = GST_DEBUG_FUNCPTR (gst_shaper_request_new_pad);
+}
+
+static GstBufferPool*
+gst_shaper_get_bufferpool (GstPad *pad)
+{
+  GstShaperConnection *connection;
+
+  connection = gst_pad_get_element_private (pad);
+
+  return gst_pad_get_bufferpool (connection->srcpad);
+}
+
+static GstCaps*
+gst_shaper_getcaps (GstPad *pad, GstCaps *caps)
+{
+  GstPad *otherpad;
+  GstShaperConnection *connection;
+
+  connection = gst_pad_get_element_private (pad);
+
+  otherpad = (pad == connection->srcpad ? connection->sinkpad : connection->srcpad);
+
+  return gst_pad_get_allowed_caps (otherpad);
+}
+
+static GList*
+gst_shaper_get_internal_link (GstPad *pad)
+{
+  GList *res = NULL;
+  GstShaperConnection *connection;
+  GstPad *otherpad;
+
+  connection = gst_pad_get_element_private (pad);
+
+  otherpad = (pad == connection->srcpad ? connection->sinkpad : connection->srcpad);
+
+  res = g_list_prepend (res, otherpad);
+
+  return res;
+}
+
+static GstPadLinkReturn
+gst_shaper_link (GstPad *pad, GstCaps *caps)
+{
+  GstPad *otherpad;
+  GstShaperConnection *connection;
+
+  connection = gst_pad_get_element_private (pad);
+
+  otherpad = (pad == connection->srcpad ? connection->sinkpad : connection->srcpad);
+
+  return gst_pad_proxy_link (otherpad, caps);
+}
+
+static GstShaperConnection*
+gst_shaper_create_connection (GstShaper *shaper)
+{
+  GstShaperConnection *connection;
+  gchar *padname;
+
+  shaper->nconnections++;
+
+  connection = g_new0 (GstShaperConnection, 1);
+
+  padname = g_strdup_printf ("sink%d", shaper->nconnections);
+  connection->sinkpad = gst_pad_new_from_template (shaper_sink_factory (), padname);
+  g_free (padname);
+  gst_pad_set_bufferpool_function (connection->sinkpad, gst_shaper_get_bufferpool);
+  gst_pad_set_getcaps_function (connection->sinkpad, gst_shaper_getcaps);
+  gst_pad_set_internal_link_function (connection->sinkpad, gst_shaper_get_internal_link);
+  gst_pad_set_link_function (connection->sinkpad, gst_shaper_link);
+  gst_pad_set_element_private (connection->sinkpad, connection);
+  gst_element_add_pad (GST_ELEMENT (shaper), connection->sinkpad);
+
+  padname = g_strdup_printf ("src%d", shaper->nconnections);
+  connection->srcpad = gst_pad_new_from_template (shaper_src_factory (), padname);
+  g_free (padname);
+  gst_pad_set_getcaps_function (connection->srcpad, gst_shaper_getcaps);
+  gst_pad_set_internal_link_function (connection->srcpad, gst_shaper_get_internal_link);
+  gst_pad_set_link_function (connection->srcpad, gst_shaper_link);
+  gst_pad_set_element_private (connection->srcpad, connection);
+  gst_element_add_pad (GST_ELEMENT (shaper), connection->srcpad);
+
+  shaper->connections = g_slist_prepend (shaper->connections, connection);
+
+  return connection;
+}
+
+static GstPad*
+gst_shaper_request_new_pad (GstElement *element, GstPadTemplate *templ, const gchar *unused)
+{
+  GstShaper *shaper = GST_SHAPER (element);
+  GstShaperConnection *connection;
+
+  connection = gst_shaper_create_connection (shaper);
+
+  return connection->sinkpad;
+}
+
+static void 
+gst_shaper_init (GstShaper *shaper) 
+{
+  gst_element_set_loop_function (GST_ELEMENT (shaper), gst_shaper_loop);
+
+  shaper->policy = SHAPER_POLICY_TIMESTAMPS;
+  shaper->connections = NULL;
+  shaper->nconnections = 0;
+  shaper->silent = FALSE;
+  shaper->last_message = NULL;
+}
+
+static void 
+gst_shaper_loop (GstElement *element) 
+{
+  GstShaper *shaper;
+  GSList *connections;
+  gboolean eos = TRUE;
+  GstShaperConnection *min = NULL;
+
+  shaper = GST_SHAPER (element);
+
+  /* first make sure we have a buffer on all pads */
+  connections = shaper->connections;
+  while (connections) {
+    GstShaperConnection *connection = (GstShaperConnection *) connections->data;
+
+    /* try to fill a connection without a buffer on a pad that is
+     * active */
+    if (connection->buffer == NULL && GST_PAD_IS_USABLE (connection->sinkpad)) {
+      GstBuffer *buffer;
+
+      buffer = gst_pad_pull (connection->sinkpad);
+
+      /* events are simply pushed ASAP */
+      if (GST_IS_EVENT (buffer)) {
+	/* save event type as it will be unreffed after the next push */
+	GstEventType type = GST_EVENT_TYPE (buffer);
+
+	gst_pad_push (connection->srcpad, buffer);
+
+	switch (type) {
+          /* on EOS we disable the pad so that we don't pull on
+	   * it again and never get more data */
+          case GST_EVENT_EOS:
+	    gst_pad_set_active (connection->sinkpad, FALSE);
+	    break;
+	  default:
+	    break;
+	}
+      }
+      else {
+	/* we store the buffer */
+	connection->buffer = buffer;
+      }
+    }
+    /* FIXME policy stuff goes here */
+    /* find connection with lowest timestamp */
+    if (min == NULL || (connection->buffer != NULL &&
+	(GST_BUFFER_TIMESTAMP (connection->buffer) < 
+	 GST_BUFFER_TIMESTAMP (min->buffer)))) 
+    {
+      min = connection;
+    }
+    connections = g_slist_next (connections);
+  }
+  /* if we have a connection with a buffer, push it */
+  if (min != NULL && min->buffer) {
+    gst_pad_push (min->srcpad, min->buffer);
+    min->buffer = NULL;
+    /* since we pushed a buffer, it's not EOS */
+    eos = FALSE;
+  }
+  
+  if (eos) {
+    gst_element_set_eos (element);
+  }
+}
+
+static void 
+gst_shaper_set_property (GObject *object, guint prop_id, const GValue *value, GParamSpec *pspec) 
+{
+  GstShaper *shaper;
+
+  /* it's not null if we got it, but it might not be ours */
+  g_return_if_fail (GST_IS_SHAPER (object));
+  
+  shaper = GST_SHAPER (object);
+
+  switch (prop_id) {
+    case ARG_POLICY:
+      shaper->policy = g_value_get_enum (value);
+      break;
+    case ARG_SILENT:
+      shaper->silent = g_value_get_boolean (value);
+      break;
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+  }
+}
+
+static void gst_shaper_get_property(GObject *object, guint prop_id, GValue *value, GParamSpec *pspec) {
+  GstShaper *shaper;
+
+  /* it's not null if we got it, but it might not be ours */
+  g_return_if_fail (GST_IS_SHAPER (object));
+  
+  shaper = GST_SHAPER (object);
+
+  switch (prop_id) {
+    case ARG_POLICY:
+      g_value_set_enum (value, shaper->policy);
+      break;
+    case ARG_SILENT:
+      g_value_set_boolean (value, shaper->silent);
+      break;
+    case ARG_LAST_MESSAGE:
+      g_value_set_string (value, shaper->last_message);
+      break;
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+  }
+}
+
+gboolean
+gst_shaper_factory_init (GstElementFactory *factory)
+{
+  gst_element_factory_add_pad_template (factory, GST_PAD_TEMPLATE_GET (shaper_src_factory));
+  gst_element_factory_add_pad_template (factory, GST_PAD_TEMPLATE_GET (shaper_sink_factory));
+
+  return TRUE;
+}
+

gst/elements/gstshaper.h

@@ -0,0 +1,77 @@
+/* GStreamer
+ * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
+ *                    2000 Wim Taymans <wtay@chello.be>
+ *
+ * gstshaper.h: 
+ *
+ * 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_SHAPER_H__
+#define __GST_SHAPER_H__
+
+
+#include <config.h>
+#include <gst/gst.h>
+
+G_BEGIN_DECLS
+
+GstElementDetails gst_shaper_details;
+
+
+#define GST_TYPE_SHAPER \
+  (gst_shaper_get_type())
+#define GST_SHAPER(obj) \
+  (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_SHAPER,GstShaper))
+#define GST_SHAPER_CLASS(klass) \
+  (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_SHAPER,GstShaperClass))
+#define GST_IS_SHAPER(obj) \
+  (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_SHAPER))
+#define GST_IS_SHAPER_CLASS(obj) \
+  (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_SHAPER))
+
+typedef enum {
+  SHAPER_POLICY_TIMESTAMPS = 1,
+  SHAPER_POLICY_BUFFERSIZE,
+} GstShaperPolicyType;
+
+typedef struct _GstShaper GstShaper;
+typedef struct _GstShaperClass GstShaperClass;
+
+struct _GstShaper {
+  GstElement 	 element;
+
+  GSList 	*connections;
+  gint		 nconnections;
+
+  GstShaperPolicyType	policy;
+
+  gboolean 	 silent;
+  gchar 	*last_message;
+};
+
+struct _GstShaperClass {
+  GstElementClass parent_class;
+};
+
+GType 		gst_shaper_get_type	(void);
+gboolean 	gst_shaper_factory_init (GstElementFactory *factory);
+
+
+G_END_DECLS
+
+#endif /* __GST_SHAPER_H__ */

plugins/elements/Makefile.am

@@ -16,6 +16,7 @@ libgstelements_la_SOURCES =	\
 	gstpipefilter.c		\
 	gsttee.c		\
 	gstaggregator.c		\
+	gstshaper.c		\
 	gststatistics.c		\
 	gstmd5sink.c
 libgstelements_la_CFLAGS = $(GST_CFLAGS)
@@ -33,6 +34,7 @@ noinst_HEADERS =		\
 	gstpipefilter.h		\
 	gsttee.h		\
 	gstaggregator.h		\
+	gstshaper.h		\
 	gststatistics.h	        \
 	gstfilesrc.h		\
 	gstmd5sink.h

plugins/elements/gstelements.c

@@ -33,6 +33,7 @@
 #include "gstpipefilter.h"
 #include "gsttee.h"
 #include "gstaggregator.h"
+#include "gstshaper.h"
 #include "gststatistics.h"
 #include "gstmd5sink.h"
 
@@ -60,6 +61,7 @@ static struct _elements_entry _elements[] = {
   { "pipefilter",   gst_pipefilter_get_type, 	&gst_pipefilter_details,	NULL },
   { "tee",     	    gst_tee_get_type, 		&gst_tee_details,		gst_tee_factory_init },
   { "aggregator",   gst_aggregator_get_type, 	&gst_aggregator_details,	gst_aggregator_factory_init },
+  { "shaper",       gst_shaper_get_type, 	&gst_shaper_details,		gst_shaper_factory_init },
   { "statistics",   gst_statistics_get_type, 	&gst_statistics_details,	NULL },
   { "md5sink",      gst_md5sink_get_type, 	&gst_md5sink_details,		gst_md5sink_factory_init },
   { NULL, 0 },

plugins/elements/gstshaper.c

@@ -0,0 +1,383 @@
+/* GStreamer
+ * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
+ *                    2000 Wim Taymans <wtay@chello.be>
+ *
+ * gstshaper.c: 
+ *
+ * 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 <stdlib.h>
+#include <gstshaper.h>
+
+GstElementDetails gst_shaper_details = {
+  "Shaper",
+  "Generic",
+  "LGPL",
+  "Synchronizes streams on different pads",
+  VERSION,
+  "Wim Taymans <wim.taymans@chello.be>",
+  "(C) 2003",
+};
+
+
+/* Shaper signals and args */
+enum {
+  /* FILL ME */
+  LAST_SIGNAL
+};
+
+enum {
+  ARG_0,
+  ARG_POLICY,
+  ARG_SILENT,
+  ARG_LAST_MESSAGE,
+};
+
+typedef struct
+{
+  GstPad 	*sinkpad;
+  GstPad 	*srcpad;
+  GstBuffer	*buffer;
+} GstShaperConnection;
+
+GST_PAD_TEMPLATE_FACTORY (shaper_src_factory,
+  "src%d",
+  GST_PAD_SRC,
+  GST_PAD_SOMETIMES,
+  NULL                  /* no caps */
+);
+
+GST_PAD_TEMPLATE_FACTORY (shaper_sink_factory,
+  "sink%d",
+  GST_PAD_SINK,
+  GST_PAD_REQUEST,
+  NULL                  /* no caps */
+);
+
+#define GST_TYPE_SHAPER_POLICY (gst_shaper_policy_get_type())
+static GType
+gst_shaper_policy_get_type (void)
+{
+  static GType shaper_policy_type = 0;
+  static GEnumValue shaper_policy[] = {
+    { SHAPER_POLICY_TIMESTAMPS,         "1", "sync on timestamps"},
+    { SHAPER_POLICY_BUFFERSIZE,         "2", "sync on buffer size"},
+    {0, NULL, NULL},
+  };
+  if (!shaper_policy_type) {
+    shaper_policy_type = g_enum_register_static ("GstShaperPolicy", shaper_policy);
+  }
+  return shaper_policy_type;
+}
+
+static void 	gst_shaper_class_init		(GstShaperClass *klass);
+static void 	gst_shaper_init			(GstShaper *shaper);
+
+static void 	gst_shaper_set_property		(GObject *object, guint prop_id, 
+						 const GValue *value, GParamSpec *pspec);
+static void 	gst_shaper_get_property		(GObject *object, guint prop_id, 
+						 GValue *value, GParamSpec *pspec);
+
+static GstPad* 	gst_shaper_request_new_pad 	(GstElement *element, GstPadTemplate *templ, 
+						 const gchar *unused);
+
+static void 	gst_shaper_loop			(GstElement *element);
+
+static GstElementClass *parent_class = NULL;
+/* static guint gst_shaper_signals[LAST_SIGNAL] = { 0 }; */
+
+GType
+gst_shaper_get_type (void) 
+{
+  static GType shaper_type = 0;
+
+  if (!shaper_type) {
+    static const GTypeInfo shaper_info = {
+      sizeof(GstShaperClass),      NULL,
+      NULL,
+      (GClassInitFunc)gst_shaper_class_init,
+      NULL,
+      NULL,
+      sizeof(GstShaper),
+      0,
+      (GInstanceInitFunc)gst_shaper_init,
+    };
+    shaper_type = g_type_register_static (GST_TYPE_ELEMENT, "GstShaper", &shaper_info, 0);
+  }
+  return shaper_type;
+}
+
+static void 
+gst_shaper_class_init (GstShaperClass *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_POLICY,
+    g_param_spec_enum ("policy", "Policy", "Shaper policy",
+                       GST_TYPE_SHAPER_POLICY, SHAPER_POLICY_TIMESTAMPS, G_PARAM_READWRITE));
+  g_object_class_install_property (G_OBJECT_CLASS (klass), ARG_SILENT,
+    g_param_spec_boolean ("silent", "silent", "silent",
+                          FALSE, G_PARAM_READWRITE)); 
+  g_object_class_install_property (G_OBJECT_CLASS (klass), ARG_LAST_MESSAGE,
+    g_param_spec_string ("last-message", "last-message", "last-message",
+                         NULL, G_PARAM_READABLE)); 
+
+  gobject_class->set_property = GST_DEBUG_FUNCPTR (gst_shaper_set_property);  
+  gobject_class->get_property = GST_DEBUG_FUNCPTR (gst_shaper_get_property);
+
+  gstelement_class->request_new_pad = GST_DEBUG_FUNCPTR (gst_shaper_request_new_pad);
+}
+
+static GstBufferPool*
+gst_shaper_get_bufferpool (GstPad *pad)
+{
+  GstShaperConnection *connection;
+
+  connection = gst_pad_get_element_private (pad);
+
+  return gst_pad_get_bufferpool (connection->srcpad);
+}
+
+static GstCaps*
+gst_shaper_getcaps (GstPad *pad, GstCaps *caps)
+{
+  GstPad *otherpad;
+  GstShaperConnection *connection;
+
+  connection = gst_pad_get_element_private (pad);
+
+  otherpad = (pad == connection->srcpad ? connection->sinkpad : connection->srcpad);
+
+  return gst_pad_get_allowed_caps (otherpad);
+}
+
+static GList*
+gst_shaper_get_internal_link (GstPad *pad)
+{
+  GList *res = NULL;
+  GstShaperConnection *connection;
+  GstPad *otherpad;
+
+  connection = gst_pad_get_element_private (pad);
+
+  otherpad = (pad == connection->srcpad ? connection->sinkpad : connection->srcpad);
+
+  res = g_list_prepend (res, otherpad);
+
+  return res;
+}
+
+static GstPadLinkReturn
+gst_shaper_link (GstPad *pad, GstCaps *caps)
+{
+  GstPad *otherpad;
+  GstShaperConnection *connection;
+
+  connection = gst_pad_get_element_private (pad);
+
+  otherpad = (pad == connection->srcpad ? connection->sinkpad : connection->srcpad);
+
+  return gst_pad_proxy_link (otherpad, caps);
+}
+
+static GstShaperConnection*
+gst_shaper_create_connection (GstShaper *shaper)
+{
+  GstShaperConnection *connection;
+  gchar *padname;
+
+  shaper->nconnections++;
+
+  connection = g_new0 (GstShaperConnection, 1);
+
+  padname = g_strdup_printf ("sink%d", shaper->nconnections);
+  connection->sinkpad = gst_pad_new_from_template (shaper_sink_factory (), padname);
+  g_free (padname);
+  gst_pad_set_bufferpool_function (connection->sinkpad, gst_shaper_get_bufferpool);
+  gst_pad_set_getcaps_function (connection->sinkpad, gst_shaper_getcaps);
+  gst_pad_set_internal_link_function (connection->sinkpad, gst_shaper_get_internal_link);
+  gst_pad_set_link_function (connection->sinkpad, gst_shaper_link);
+  gst_pad_set_element_private (connection->sinkpad, connection);
+  gst_element_add_pad (GST_ELEMENT (shaper), connection->sinkpad);
+
+  padname = g_strdup_printf ("src%d", shaper->nconnections);
+  connection->srcpad = gst_pad_new_from_template (shaper_src_factory (), padname);
+  g_free (padname);
+  gst_pad_set_getcaps_function (connection->srcpad, gst_shaper_getcaps);
+  gst_pad_set_internal_link_function (connection->srcpad, gst_shaper_get_internal_link);
+  gst_pad_set_link_function (connection->srcpad, gst_shaper_link);
+  gst_pad_set_element_private (connection->srcpad, connection);
+  gst_element_add_pad (GST_ELEMENT (shaper), connection->srcpad);
+
+  shaper->connections = g_slist_prepend (shaper->connections, connection);
+
+  return connection;
+}
+
+static GstPad*
+gst_shaper_request_new_pad (GstElement *element, GstPadTemplate *templ, const gchar *unused)
+{
+  GstShaper *shaper = GST_SHAPER (element);
+  GstShaperConnection *connection;
+
+  connection = gst_shaper_create_connection (shaper);
+
+  return connection->sinkpad;
+}
+
+static void 
+gst_shaper_init (GstShaper *shaper) 
+{
+  gst_element_set_loop_function (GST_ELEMENT (shaper), gst_shaper_loop);
+
+  shaper->policy = SHAPER_POLICY_TIMESTAMPS;
+  shaper->connections = NULL;
+  shaper->nconnections = 0;
+  shaper->silent = FALSE;
+  shaper->last_message = NULL;
+}
+
+static void 
+gst_shaper_loop (GstElement *element) 
+{
+  GstShaper *shaper;
+  GSList *connections;
+  gboolean eos = TRUE;
+  GstShaperConnection *min = NULL;
+
+  shaper = GST_SHAPER (element);
+
+  /* first make sure we have a buffer on all pads */
+  connections = shaper->connections;
+  while (connections) {
+    GstShaperConnection *connection = (GstShaperConnection *) connections->data;
+
+    /* try to fill a connection without a buffer on a pad that is
+     * active */
+    if (connection->buffer == NULL && GST_PAD_IS_USABLE (connection->sinkpad)) {
+      GstBuffer *buffer;
+
+      buffer = gst_pad_pull (connection->sinkpad);
+
+      /* events are simply pushed ASAP */
+      if (GST_IS_EVENT (buffer)) {
+	/* save event type as it will be unreffed after the next push */
+	GstEventType type = GST_EVENT_TYPE (buffer);
+
+	gst_pad_push (connection->srcpad, buffer);
+
+	switch (type) {
+          /* on EOS we disable the pad so that we don't pull on
+	   * it again and never get more data */
+          case GST_EVENT_EOS:
+	    gst_pad_set_active (connection->sinkpad, FALSE);
+	    break;
+	  default:
+	    break;
+	}
+      }
+      else {
+	/* we store the buffer */
+	connection->buffer = buffer;
+      }
+    }
+    /* FIXME policy stuff goes here */
+    /* find connection with lowest timestamp */
+    if (min == NULL || (connection->buffer != NULL &&
+	(GST_BUFFER_TIMESTAMP (connection->buffer) < 
+	 GST_BUFFER_TIMESTAMP (min->buffer)))) 
+    {
+      min = connection;
+    }
+    connections = g_slist_next (connections);
+  }
+  /* if we have a connection with a buffer, push it */
+  if (min != NULL && min->buffer) {
+    gst_pad_push (min->srcpad, min->buffer);
+    min->buffer = NULL;
+    /* since we pushed a buffer, it's not EOS */
+    eos = FALSE;
+  }
+  
+  if (eos) {
+    gst_element_set_eos (element);
+  }
+}
+
+static void 
+gst_shaper_set_property (GObject *object, guint prop_id, const GValue *value, GParamSpec *pspec) 
+{
+  GstShaper *shaper;
+
+  /* it's not null if we got it, but it might not be ours */
+  g_return_if_fail (GST_IS_SHAPER (object));
+  
+  shaper = GST_SHAPER (object);
+
+  switch (prop_id) {
+    case ARG_POLICY:
+      shaper->policy = g_value_get_enum (value);
+      break;
+    case ARG_SILENT:
+      shaper->silent = g_value_get_boolean (value);
+      break;
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+  }
+}
+
+static void gst_shaper_get_property(GObject *object, guint prop_id, GValue *value, GParamSpec *pspec) {
+  GstShaper *shaper;
+
+  /* it's not null if we got it, but it might not be ours */
+  g_return_if_fail (GST_IS_SHAPER (object));
+  
+  shaper = GST_SHAPER (object);
+
+  switch (prop_id) {
+    case ARG_POLICY:
+      g_value_set_enum (value, shaper->policy);
+      break;
+    case ARG_SILENT:
+      g_value_set_boolean (value, shaper->silent);
+      break;
+    case ARG_LAST_MESSAGE:
+      g_value_set_string (value, shaper->last_message);
+      break;
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+  }
+}
+
+gboolean
+gst_shaper_factory_init (GstElementFactory *factory)
+{
+  gst_element_factory_add_pad_template (factory, GST_PAD_TEMPLATE_GET (shaper_src_factory));
+  gst_element_factory_add_pad_template (factory, GST_PAD_TEMPLATE_GET (shaper_sink_factory));
+
+  return TRUE;
+}
+

plugins/elements/gstshaper.h

@@ -0,0 +1,77 @@
+/* GStreamer
+ * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
+ *                    2000 Wim Taymans <wtay@chello.be>
+ *
+ * gstshaper.h: 
+ *
+ * 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_SHAPER_H__
+#define __GST_SHAPER_H__
+
+
+#include <config.h>
+#include <gst/gst.h>
+
+G_BEGIN_DECLS
+
+GstElementDetails gst_shaper_details;
+
+
+#define GST_TYPE_SHAPER \
+  (gst_shaper_get_type())
+#define GST_SHAPER(obj) \
+  (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_SHAPER,GstShaper))
+#define GST_SHAPER_CLASS(klass) \
+  (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_SHAPER,GstShaperClass))
+#define GST_IS_SHAPER(obj) \
+  (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_SHAPER))
+#define GST_IS_SHAPER_CLASS(obj) \
+  (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_SHAPER))
+
+typedef enum {
+  SHAPER_POLICY_TIMESTAMPS = 1,
+  SHAPER_POLICY_BUFFERSIZE,
+} GstShaperPolicyType;
+
+typedef struct _GstShaper GstShaper;
+typedef struct _GstShaperClass GstShaperClass;
+
+struct _GstShaper {
+  GstElement 	 element;
+
+  GSList 	*connections;
+  gint		 nconnections;
+
+  GstShaperPolicyType	policy;
+
+  gboolean 	 silent;
+  gchar 	*last_message;
+};
+
+struct _GstShaperClass {
+  GstElementClass parent_class;
+};
+
+GType 		gst_shaper_get_type	(void);
+gboolean 	gst_shaper_factory_init (GstElementFactory *factory);
+
+
+G_END_DECLS
+
+#endif /* __GST_SHAPER_H__ */