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 gboolean gst_valve_event (GstPad * pad, GstEvent * event);
76 static GstFlowReturn gst_valve_buffer_alloc (GstPad * pad, guint64 offset,
77 guint size, GstCaps * caps, GstBuffer ** buf);
78 static GstFlowReturn gst_valve_chain (GstPad * pad, GstBuffer * buffer);
79 static GstCaps *gst_valve_getcaps (GstPad * pad);
81 #define _do_init(bla) \
82 GST_DEBUG_CATEGORY_INIT (valve_debug, "valve", 0, "Valve");
84 GST_BOILERPLATE_FULL (GstValve, gst_valve, GstElement,
85 GST_TYPE_ELEMENT, _do_init);
88 gst_valve_base_init (gpointer klass)
90 GstElementClass *element_class = GST_ELEMENT_CLASS (klass);
92 gst_element_class_add_pad_template (element_class,
93 gst_static_pad_template_get (&srctemplate));
94 gst_element_class_add_pad_template (element_class,
95 gst_static_pad_template_get (&sinktemplate));
97 gst_element_class_set_details_simple (element_class, "Valve element",
98 "Filter", "Drops buffers and events or lets them through",
99 "Olivier Crete <olivier.crete@collabora.co.uk>");
103 gst_valve_class_init (GstValveClass * klass)
105 GObjectClass *gobject_class;
107 gobject_class = (GObjectClass *) klass;
109 gobject_class->set_property = gst_valve_set_property;
110 gobject_class->get_property = gst_valve_get_property;
112 g_object_class_install_property (gobject_class, PROP_DROP,
113 g_param_spec_boolean ("drop", "Drop buffers and events",
114 "Whether to drop buffers and events or let them through",
115 DEFAULT_DROP, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
119 gst_valve_init (GstValve * valve, GstValveClass * klass)
122 valve->discont = FALSE;
124 valve->srcpad = gst_pad_new_from_static_template (&srctemplate, "src");
125 gst_pad_set_getcaps_function (valve->srcpad,
126 GST_DEBUG_FUNCPTR (gst_valve_getcaps));
127 gst_element_add_pad (GST_ELEMENT (valve), valve->srcpad);
129 valve->sinkpad = gst_pad_new_from_static_template (&sinktemplate, "sink");
130 gst_pad_set_chain_function (valve->sinkpad,
131 GST_DEBUG_FUNCPTR (gst_valve_chain));
132 gst_pad_set_event_function (valve->sinkpad,
133 GST_DEBUG_FUNCPTR (gst_valve_event));
134 gst_pad_set_bufferalloc_function (valve->sinkpad,
135 GST_DEBUG_FUNCPTR (gst_valve_buffer_alloc));
136 gst_pad_set_getcaps_function (valve->sinkpad,
137 GST_DEBUG_FUNCPTR (gst_valve_getcaps));
138 gst_element_add_pad (GST_ELEMENT (valve), valve->sinkpad);
143 gst_valve_set_property (GObject * object,
144 guint prop_id, const GValue * value, GParamSpec * pspec)
146 GstValve *valve = GST_VALVE (object);
150 g_atomic_int_set (&valve->drop, g_value_get_boolean (value));
153 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
159 gst_valve_get_property (GObject * object,
160 guint prop_id, GValue * value, GParamSpec * pspec)
162 GstValve *valve = GST_VALVE (object);
166 g_value_set_boolean (value, g_atomic_int_get (&valve->drop));
169 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
175 gst_valve_chain (GstPad * pad, GstBuffer * buffer)
177 GstValve *valve = GST_VALVE (GST_OBJECT_PARENT (pad));
178 GstFlowReturn ret = GST_FLOW_OK;
180 if (g_atomic_int_get (&valve->drop)) {
181 gst_buffer_unref (buffer);
182 valve->discont = TRUE;
184 if (valve->discont) {
185 buffer = gst_buffer_make_metadata_writable (buffer);
186 GST_BUFFER_FLAG_SET (buffer, GST_BUFFER_FLAG_DISCONT);
187 valve->discont = FALSE;
190 ret = gst_pad_push (valve->srcpad, buffer);
194 /* Ignore errors if "drop" was changed while the thread was blocked
197 if (g_atomic_int_get (&valve->drop))
205 gst_valve_event (GstPad * pad, GstEvent * event)
207 GstValve *valve = GST_VALVE (gst_pad_get_parent_element (pad));
210 if (g_atomic_int_get (&valve->drop))
211 gst_event_unref (event);
213 ret = gst_pad_push_event (valve->srcpad, event);
215 /* Ignore errors if "drop" was changed while the thread was blocked
218 if (g_atomic_int_get (&valve->drop))
221 gst_object_unref (valve);
226 gst_valve_buffer_alloc (GstPad * pad, guint64 offset, guint size,
227 GstCaps * caps, GstBuffer ** buf)
229 GstValve *valve = GST_VALVE (gst_pad_get_parent_element (pad));
230 GstFlowReturn ret = GST_FLOW_OK;
232 if (g_atomic_int_get (&valve->drop))
235 ret = gst_pad_alloc_buffer (valve->srcpad, offset, size, caps, buf);
237 /* Ignore errors if "drop" was changed while the thread was blocked
240 if (g_atomic_int_get (&valve->drop))
243 gst_object_unref (valve);
249 gst_valve_getcaps (GstPad * pad)
251 GstValve *valve = GST_VALVE (gst_pad_get_parent (pad));
254 if (pad == valve->sinkpad)
255 caps = gst_pad_peer_get_caps (valve->srcpad);
257 caps = gst_pad_peer_get_caps (valve->sinkpad);
260 caps = gst_caps_copy (gst_pad_get_pad_template_caps (pad));
262 gst_object_unref (valve);