1 /* GStreamer valve element
2 * Copyright 2007-2009 Collabora Ltd
3 * @author: Olivier Crete <olivier.crete@collabora.co.uk>
4 * Copyright 2007-2009 Nokia Corporation
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Library General Public
8 * License as published by the Free Software Foundation; either
9 * version 2 of the License, or (at your option) any later version.
11 * This library is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Library General Public License for more details.
16 * You should have received a copy of the GNU Library General Public
17 * License along with this library; if not, write to the
18 * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
19 * Boston, MA 02110-1301, USA.
24 * SECTION:element-valve
26 * The valve is a simple element that drops buffers when the #GstValve:drop
27 * property is set to %TRUE and lets then through otherwise.
29 * Any downstream error received while the #GstValve:drop property is %FALSE
30 * is ignored. So downstream element can be set to %GST_STATE_NULL and removed,
31 * without using pad blocking.
42 GST_DEBUG_CATEGORY_STATIC (valve_debug);
43 #define GST_CAT_DEFAULT (valve_debug)
45 static GstStaticPadTemplate sinktemplate = GST_STATIC_PAD_TEMPLATE ("sink",
50 static GstStaticPadTemplate srctemplate = GST_STATIC_PAD_TEMPLATE ("src",
61 #define DEFAULT_DROP FALSE
63 static void gst_valve_set_property (GObject * object,
64 guint prop_id, const GValue * value, GParamSpec * pspec);
65 static void gst_valve_get_property (GObject * object,
66 guint prop_id, GValue * value, GParamSpec * pspec);
68 static GstFlowReturn gst_valve_chain (GstPad * pad, GstObject * parent,
70 static gboolean gst_valve_event (GstPad * pad, GstObject * parent,
72 static gboolean gst_valve_query (GstPad * pad, GstObject * parent,
76 GST_DEBUG_CATEGORY_INIT (valve_debug, "valve", 0, "Valve");
77 #define gst_valve_parent_class parent_class
78 G_DEFINE_TYPE_WITH_CODE (GstValve, gst_valve, GST_TYPE_ELEMENT, _do_init);
81 gst_valve_class_init (GstValveClass * klass)
83 GObjectClass *gobject_class;
84 GstElementClass *gstelement_class;
86 gobject_class = (GObjectClass *) klass;
87 gstelement_class = (GstElementClass *) (klass);
89 gobject_class->set_property = gst_valve_set_property;
90 gobject_class->get_property = gst_valve_get_property;
92 g_object_class_install_property (gobject_class, PROP_DROP,
93 g_param_spec_boolean ("drop", "Drop buffers and events",
94 "Whether to drop buffers and events or let them through",
95 DEFAULT_DROP, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
97 gst_element_class_add_pad_template (gstelement_class,
98 gst_static_pad_template_get (&srctemplate));
99 gst_element_class_add_pad_template (gstelement_class,
100 gst_static_pad_template_get (&sinktemplate));
102 gst_element_class_set_static_metadata (gstelement_class, "Valve element",
103 "Filter", "Drops buffers and events or lets them through",
104 "Olivier Crete <olivier.crete@collabora.co.uk>");
108 gst_valve_init (GstValve * valve)
111 valve->discont = FALSE;
113 valve->srcpad = gst_pad_new_from_static_template (&srctemplate, "src");
114 gst_pad_set_event_function (valve->srcpad,
115 GST_DEBUG_FUNCPTR (gst_valve_event));
116 gst_pad_set_query_function (valve->srcpad,
117 GST_DEBUG_FUNCPTR (gst_valve_query));
118 GST_PAD_SET_PROXY_CAPS (valve->srcpad);
119 gst_element_add_pad (GST_ELEMENT (valve), valve->srcpad);
121 valve->sinkpad = gst_pad_new_from_static_template (&sinktemplate, "sink");
122 gst_pad_set_chain_function (valve->sinkpad,
123 GST_DEBUG_FUNCPTR (gst_valve_chain));
124 gst_pad_set_event_function (valve->sinkpad,
125 GST_DEBUG_FUNCPTR (gst_valve_event));
126 gst_pad_set_query_function (valve->sinkpad,
127 GST_DEBUG_FUNCPTR (gst_valve_query));
128 GST_PAD_SET_PROXY_CAPS (valve->sinkpad);
129 GST_PAD_SET_PROXY_ALLOCATION (valve->sinkpad);
130 gst_element_add_pad (GST_ELEMENT (valve), valve->sinkpad);
135 gst_valve_set_property (GObject * object,
136 guint prop_id, const GValue * value, GParamSpec * pspec)
138 GstValve *valve = GST_VALVE (object);
142 g_atomic_int_set (&valve->drop, g_value_get_boolean (value));
143 gst_pad_push_event (valve->sinkpad, gst_event_new_reconfigure ());
146 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
152 gst_valve_get_property (GObject * object,
153 guint prop_id, GValue * value, GParamSpec * pspec)
155 GstValve *valve = GST_VALVE (object);
159 g_value_set_boolean (value, g_atomic_int_get (&valve->drop));
162 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
169 forward_sticky_events (GstPad * pad, GstEvent ** event, gpointer user_data)
171 GstValve *valve = user_data;
173 if (!gst_pad_push_event (valve->srcpad, gst_event_ref (*event)))
174 valve->need_repush_sticky = TRUE;
180 gst_valve_repush_sticky (GstValve * valve)
182 valve->need_repush_sticky = FALSE;
183 gst_pad_sticky_events_foreach (valve->sinkpad, forward_sticky_events, valve);
187 gst_valve_chain (GstPad * pad, GstObject * parent, GstBuffer * buffer)
189 GstValve *valve = GST_VALVE (parent);
190 GstFlowReturn ret = GST_FLOW_OK;
192 if (g_atomic_int_get (&valve->drop)) {
193 gst_buffer_unref (buffer);
194 valve->discont = TRUE;
196 if (valve->discont) {
197 buffer = gst_buffer_make_writable (buffer);
198 GST_BUFFER_FLAG_SET (buffer, GST_BUFFER_FLAG_DISCONT);
199 valve->discont = FALSE;
202 if (valve->need_repush_sticky)
203 gst_valve_repush_sticky (valve);
205 ret = gst_pad_push (valve->srcpad, buffer);
209 /* Ignore errors if "drop" was changed while the thread was blocked
212 if (g_atomic_int_get (&valve->drop))
220 gst_valve_event (GstPad * pad, GstObject * parent, GstEvent * event)
223 gboolean is_sticky = GST_EVENT_IS_STICKY (event);
226 valve = GST_VALVE (parent);
228 if (g_atomic_int_get (&valve->drop)) {
229 valve->need_repush_sticky |= is_sticky;
230 gst_event_unref (event);
232 if (valve->need_repush_sticky)
233 gst_valve_repush_sticky (valve);
234 ret = gst_pad_event_default (pad, parent, event);
237 /* Ignore errors if "drop" was changed while the thread was blocked
240 if (g_atomic_int_get (&valve->drop)) {
241 valve->need_repush_sticky |= is_sticky;
251 gst_valve_query (GstPad * pad, GstObject * parent, GstQuery * query)
253 GstValve *valve = GST_VALVE (parent);
255 if (g_atomic_int_get (&valve->drop))
258 return gst_pad_query_default (pad, parent, query);