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., 59 Temple Place - Suite 330,
19 * Boston, MA 02111-1307, 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.
33 * This element was previously part of gst-plugins-farsight, and then
36 * Documentation last reviewed on 2010-12-30 (0.10.31)
49 GST_DEBUG_CATEGORY_STATIC (valve_debug);
50 #define GST_CAT_DEFAULT (valve_debug)
52 static GstStaticPadTemplate sinktemplate = GST_STATIC_PAD_TEMPLATE ("sink",
57 static GstStaticPadTemplate srctemplate = GST_STATIC_PAD_TEMPLATE ("src",
68 #define DEFAULT_DROP FALSE
70 static void gst_valve_set_property (GObject * object,
71 guint prop_id, const GValue * value, GParamSpec * pspec);
72 static void gst_valve_get_property (GObject * object,
73 guint prop_id, GValue * value, GParamSpec * pspec);
75 static GstFlowReturn gst_valve_chain (GstPad * pad, GstBuffer * buffer);
76 static gboolean gst_valve_sink_event (GstPad * pad, GstEvent * event);
77 static gboolean gst_valve_query (GstPad * pad, GstObject * parent,
81 GST_DEBUG_CATEGORY_INIT (valve_debug, "valve", 0, "Valve");
82 #define gst_valve_parent_class parent_class
83 G_DEFINE_TYPE_WITH_CODE (GstValve, gst_valve, GST_TYPE_ELEMENT, _do_init);
86 gst_valve_class_init (GstValveClass * klass)
88 GObjectClass *gobject_class;
89 GstElementClass *gstelement_class;
91 gobject_class = (GObjectClass *) klass;
92 gstelement_class = (GstElementClass *) (klass);
94 gobject_class->set_property = gst_valve_set_property;
95 gobject_class->get_property = gst_valve_get_property;
97 g_object_class_install_property (gobject_class, PROP_DROP,
98 g_param_spec_boolean ("drop", "Drop buffers and events",
99 "Whether to drop buffers and events or let them through",
100 DEFAULT_DROP, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
102 gst_element_class_add_pad_template (gstelement_class,
103 gst_static_pad_template_get (&srctemplate));
104 gst_element_class_add_pad_template (gstelement_class,
105 gst_static_pad_template_get (&sinktemplate));
107 gst_element_class_set_details_simple (gstelement_class, "Valve element",
108 "Filter", "Drops buffers and events or lets them through",
109 "Olivier Crete <olivier.crete@collabora.co.uk>");
113 gst_valve_init (GstValve * valve)
116 valve->discont = FALSE;
118 valve->srcpad = gst_pad_new_from_static_template (&srctemplate, "src");
119 gst_pad_set_query_function (valve->srcpad,
120 GST_DEBUG_FUNCPTR (gst_valve_query));
121 gst_element_add_pad (GST_ELEMENT (valve), valve->srcpad);
123 valve->sinkpad = gst_pad_new_from_static_template (&sinktemplate, "sink");
124 gst_pad_set_chain_function (valve->sinkpad,
125 GST_DEBUG_FUNCPTR (gst_valve_chain));
126 gst_pad_set_event_function (valve->sinkpad,
127 GST_DEBUG_FUNCPTR (gst_valve_sink_event));
128 gst_pad_set_query_function (valve->sinkpad,
129 GST_DEBUG_FUNCPTR (gst_valve_query));
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));
145 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
151 gst_valve_get_property (GObject * object,
152 guint prop_id, GValue * value, GParamSpec * pspec)
154 GstValve *valve = GST_VALVE (object);
158 g_value_set_boolean (value, g_atomic_int_get (&valve->drop));
161 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
167 gst_valve_chain (GstPad * pad, GstBuffer * buffer)
169 GstValve *valve = GST_VALVE (GST_OBJECT_PARENT (pad));
170 GstFlowReturn ret = GST_FLOW_OK;
172 if (g_atomic_int_get (&valve->drop)) {
173 gst_buffer_unref (buffer);
174 valve->discont = TRUE;
176 if (valve->discont) {
177 buffer = gst_buffer_make_writable (buffer);
178 GST_BUFFER_FLAG_SET (buffer, GST_BUFFER_FLAG_DISCONT);
179 valve->discont = FALSE;
182 ret = gst_pad_push (valve->srcpad, buffer);
186 /* Ignore errors if "drop" was changed while the thread was blocked
189 if (g_atomic_int_get (&valve->drop))
197 gst_valve_sink_event (GstPad * pad, GstEvent * event)
202 valve = GST_VALVE (GST_PAD_PARENT (pad));
204 if (g_atomic_int_get (&valve->drop))
205 gst_event_unref (event);
207 ret = gst_pad_push_event (valve->srcpad, event);
209 /* Ignore errors if "drop" was changed while the thread was blocked
212 if (g_atomic_int_get (&valve->drop))
219 gst_valve_query (GstPad * pad, GstObject * parent, GstQuery * query)
225 valve = GST_VALVE (parent);
227 otherpad = (pad == valve->sinkpad ? valve->srcpad : valve->sinkpad);
229 switch (GST_QUERY_TYPE (query)) {
231 if (!(res = gst_pad_peer_query (otherpad, query)))
232 res = gst_pad_query_default (pad, parent, query);
235 res = gst_pad_peer_query (otherpad, query);