2 * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
3 * 2000 Wim Taymans <wtay@chello.be>
4 * 2003 Benjamin Otte <in7y118@public.uni-hamburg.de>
6 * gstdevicemonitorfactory.c: GstDeviceMonitorFactory object, support routines
8 * This library is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Library General Public
10 * License as published by the Free Software Foundation; either
11 * version 2 of the License, or (at your option) any later version.
13 * This library is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Library General Public License for more details.
18 * You should have received a copy of the GNU Library General Public
19 * License along with this library; if not, write to the
20 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
21 * Boston, MA 02111-1307, USA.
25 * SECTION:gstdevicemonitorfactory
26 * @short_description: Create GstDeviceMonitors from a factory
27 * @see_also: #GstDeviceMonitor, #GstPlugin, #GstPluginFeature, #GstPadTemplate.
29 * #GstDeviceMonitorFactory is used to create instances of device monitors. A
30 * GstDeviceMonitorfactory can be added to a #GstPlugin as it is also a
33 * Use the gst_device_monitor_factory_find() and gst_device_monitor_factory_create()
34 * functions to create device monitor instances or use gst_device_monitor_factory_make() as a
35 * convenient shortcut.
44 #include "gst_private.h"
46 #include "gstdevicemonitorfactory.h"
49 #include "glib-compat-private.h"
51 GST_DEBUG_CATEGORY_STATIC (device_monitor_factory_debug);
52 #define GST_CAT_DEFAULT device_monitor_factory_debug
54 static void gst_device_monitor_factory_finalize (GObject * object);
55 static void gst_device_monitor_factory_cleanup (GstDeviceMonitorFactory *
58 /* static guint gst_device_monitor_factory_signals[LAST_SIGNAL] = { 0 }; */
60 /* this is defined in gstelement.c */
61 extern GQuark __gst_devicemonitorclass_factory;
65 GST_DEBUG_CATEGORY_INIT (device_monitor_factory_debug, "GST_DEVICE_MONITOR_FACTORY", \
66 GST_DEBUG_BOLD | GST_DEBUG_FG_WHITE | GST_DEBUG_BG_RED, \
67 "device monitor factories keep information about installed device monitors"); \
70 G_DEFINE_TYPE_WITH_CODE (GstDeviceMonitorFactory, gst_device_monitor_factory,
71 GST_TYPE_PLUGIN_FEATURE, _do_init);
74 gst_device_monitor_factory_class_init (GstDeviceMonitorFactoryClass * klass)
76 GObjectClass *gobject_class = (GObjectClass *) klass;
78 gobject_class->finalize = gst_device_monitor_factory_finalize;
82 gst_device_monitor_factory_init (GstDeviceMonitorFactory * factory)
87 gst_device_monitor_factory_finalize (GObject * object)
89 GstDeviceMonitorFactory *factory = GST_DEVICE_MONITOR_FACTORY (object);
90 GstDeviceMonitor *monitor;
92 gst_device_monitor_factory_cleanup (factory);
94 monitor = g_atomic_pointer_get (&factory->monitor);
96 gst_object_unref (monitor);
98 G_OBJECT_CLASS (gst_device_monitor_factory_parent_class)->finalize (object);
102 * gst_device_monitor_factory_find:
103 * @name: name of factory to find
105 * Search for an device monitor factory of the given name. Refs the returned
106 * device monitor factory; caller is responsible for unreffing.
108 * Returns: (transfer full): #GstDeviceMonitorFactory if found, NULL otherwise
112 GstDeviceMonitorFactory *
113 gst_device_monitor_factory_find (const gchar * name)
115 GstPluginFeature *feature;
117 g_return_val_if_fail (name != NULL, NULL);
119 feature = gst_registry_find_feature (gst_registry_get (), name,
120 GST_TYPE_DEVICE_MONITOR_FACTORY);
122 return GST_DEVICE_MONITOR_FACTORY (feature);
124 /* this isn't an error, for instance when you query if an device monitor factory is
126 GST_LOG ("no such device monitor factory \"%s\"", name);
132 gst_device_monitor_factory_cleanup (GstDeviceMonitorFactory * factory)
134 if (factory->metadata) {
135 gst_structure_free ((GstStructure *) factory->metadata);
136 factory->metadata = NULL;
139 factory->type = G_TYPE_INVALID;
143 #define CHECK_METADATA_FIELD(klass, name, key) \
145 const gchar *metafield = gst_device_monitor_class_get_metadata (klass, key); \
146 if (G_UNLIKELY (metafield == NULL || *metafield == '\0')) { \
147 g_warning ("Device monitor factory metadata for '%s' has no valid %s field", name, key); \
153 * gst_device_monitor_register:
154 * @plugin: (allow-none): #GstPlugin to register the device monitor with, or NULL for
155 * a static device monitor.
156 * @name: name of device monitors of this type
157 * @rank: rank of device monitor (higher rank means more importance when autoplugging)
158 * @type: GType of device monitor to register
160 * Create a new device monitorfactory capable of instantiating objects of the
161 * @type and add the factory to @plugin.
163 * Returns: TRUE, if the registering succeeded, FALSE on error
168 gst_device_monitor_register (GstPlugin * plugin, const gchar * name, guint rank,
171 GstPluginFeature *existing_feature;
172 GstRegistry *registry;
173 GstDeviceMonitorFactory *factory;
174 GstDeviceMonitorClass *klass;
176 g_return_val_if_fail (name != NULL, FALSE);
177 g_return_val_if_fail (g_type_is_a (type, GST_TYPE_DEVICE_MONITOR), FALSE);
179 registry = gst_registry_get ();
181 /* check if feature already exists, if it exists there is no need to update it
182 * when the registry is getting updated, outdated plugins and all their
183 * features are removed and readded.
185 existing_feature = gst_registry_lookup_feature (registry, name);
186 if (existing_feature) {
187 GST_DEBUG_OBJECT (registry, "update existing feature %p (%s)",
188 existing_feature, name);
189 factory = GST_DEVICE_MONITOR_FACTORY_CAST (existing_feature);
190 factory->type = type;
191 existing_feature->loaded = TRUE;
192 g_type_set_qdata (type, __gst_devicemonitorclass_factory, factory);
193 gst_object_unref (existing_feature);
198 GST_DEVICE_MONITOR_FACTORY_CAST (g_object_newv
199 (GST_TYPE_DEVICE_MONITOR_FACTORY, 0, NULL));
200 gst_plugin_feature_set_name (GST_PLUGIN_FEATURE_CAST (factory), name);
201 GST_LOG_OBJECT (factory, "Created new device monitorfactory for type %s",
204 /* provide info needed during class structure setup */
205 g_type_set_qdata (type, __gst_devicemonitorclass_factory, factory);
206 klass = GST_DEVICE_MONITOR_CLASS (g_type_class_ref (type));
208 CHECK_METADATA_FIELD (klass, name, GST_ELEMENT_METADATA_LONGNAME);
209 CHECK_METADATA_FIELD (klass, name, GST_ELEMENT_METADATA_KLASS);
210 CHECK_METADATA_FIELD (klass, name, GST_ELEMENT_METADATA_DESCRIPTION);
211 CHECK_METADATA_FIELD (klass, name, GST_ELEMENT_METADATA_AUTHOR);
213 factory->type = type;
214 factory->metadata = gst_structure_copy ((GstStructure *) klass->metadata);
216 if (plugin && plugin->desc.name) {
217 GST_PLUGIN_FEATURE_CAST (factory)->plugin_name = plugin->desc.name;
218 GST_PLUGIN_FEATURE_CAST (factory)->plugin = plugin;
219 g_object_add_weak_pointer ((GObject *) plugin,
220 (gpointer *) & GST_PLUGIN_FEATURE_CAST (factory)->plugin);
222 GST_PLUGIN_FEATURE_CAST (factory)->plugin_name = "NULL";
223 GST_PLUGIN_FEATURE_CAST (factory)->plugin = NULL;
225 gst_plugin_feature_set_rank (GST_PLUGIN_FEATURE_CAST (factory), rank);
226 GST_PLUGIN_FEATURE_CAST (factory)->loaded = TRUE;
228 gst_registry_add_feature (registry, GST_PLUGIN_FEATURE_CAST (factory));
235 gst_device_monitor_factory_cleanup (factory);
241 * gst_device_monitor_factory_get:
242 * @factory: factory to instantiate
244 * Returns the device monitor of the type defined by the given device
247 * Returns: (transfer full): the #GstDeviceMonitor or NULL if the
248 * device monitor couldn't be created
253 gst_device_monitor_factory_get (GstDeviceMonitorFactory * factory)
255 GstDeviceMonitor *device_monitor;
256 GstDeviceMonitorClass *oclass;
257 GstDeviceMonitorFactory *newfactory;
259 g_return_val_if_fail (factory != NULL, NULL);
262 GST_DEVICE_MONITOR_FACTORY (gst_plugin_feature_load (GST_PLUGIN_FEATURE
265 if (newfactory == NULL)
268 factory = newfactory;
270 GST_INFO ("getting device monitor \"%s\"", GST_OBJECT_NAME (factory));
272 if (factory->type == 0)
275 device_monitor = g_atomic_pointer_get (&newfactory->monitor);
277 return gst_object_ref (device_monitor);
279 /* create an instance of the device monitor, cast so we don't assert on NULL
280 * also set name as early as we can
282 device_monitor = GST_DEVICE_MONITOR_CAST (g_object_newv (factory->type, 0,
284 if (G_UNLIKELY (device_monitor == NULL))
285 goto no_device_monitor;
287 /* fill in the pointer to the factory in the device monitor class. The
288 * class will not be unreffed currently.
289 * Be thread safe as there might be 2 threads creating the first instance of
290 * an device monitor at the same moment
292 oclass = GST_DEVICE_MONITOR_GET_CLASS (device_monitor);
293 if (!g_atomic_pointer_compare_and_exchange (&oclass->factory, NULL, factory))
294 gst_object_unref (factory);
296 gst_object_ref_sink (device_monitor);
298 /* We use an atomic to make sure we don't create two in parallel */
299 if (!g_atomic_pointer_compare_and_exchange (&newfactory->monitor, NULL,
301 gst_object_unref (device_monitor);
303 device_monitor = g_atomic_pointer_get (&newfactory->monitor);
306 GST_DEBUG ("created device monitor \"%s\"", GST_OBJECT_NAME (factory));
308 return gst_object_ref (device_monitor);
313 GST_WARNING_OBJECT (factory,
314 "loading plugin containing feature %s returned NULL!",
315 GST_OBJECT_NAME (factory));
320 GST_WARNING_OBJECT (factory, "factory has no type");
321 gst_object_unref (factory);
326 GST_WARNING_OBJECT (factory, "could not create device monitor");
327 gst_object_unref (factory);
333 * gst_device_monitor_factory_get_by_name:
334 * @factoryname: a named factory to instantiate
336 * Returns the device monitor of the type defined by the given device
339 * Returns: (transfer full): a #GstDeviceMonitor or NULL if unable to
340 * create device monitor
345 gst_device_monitor_factory_get_by_name (const gchar * factoryname)
347 GstDeviceMonitorFactory *factory;
348 GstDeviceMonitor *device_monitor;
350 g_return_val_if_fail (factoryname != NULL, NULL);
351 g_return_val_if_fail (gst_is_initialized (), NULL);
353 GST_LOG ("gstdevicemonitorfactory: get_by_name \"%s\"", factoryname);
355 factory = gst_device_monitor_factory_find (factoryname);
359 GST_LOG_OBJECT (factory, "found factory %p", factory);
360 device_monitor = gst_device_monitor_factory_get (factory);
361 if (device_monitor == NULL)
364 gst_object_unref (factory);
365 return device_monitor;
370 GST_INFO ("no such device monitor factory \"%s\"!", factoryname);
375 GST_INFO_OBJECT (factory, "couldn't create instance!");
376 gst_object_unref (factory);
382 * gst_device_monitor_factory_get_device_monitor_type:
383 * @factory: factory to get managed #GType from
385 * Get the #GType for device monitors managed by this factory. The type can
386 * only be retrieved if the device monitor factory is loaded, which can be
387 * assured with gst_plugin_feature_load().
389 * Returns: the #GType for device monitors managed by this factory or 0 if
390 * the factory is not loaded.
395 gst_device_monitor_factory_get_device_monitor_type (GstDeviceMonitorFactory *
398 g_return_val_if_fail (GST_IS_DEVICE_MONITOR_FACTORY (factory), 0);
400 return factory->type;
404 * gst_device_monitor_factory_get_metadata:
405 * @factory: a #GstDeviceMonitorFactory
408 * Get the metadata on @factory with @key.
410 * Returns: the metadata with @key on @factory or %NULL when there was no
411 * metadata with the given @key.
416 gst_device_monitor_factory_get_metadata (GstDeviceMonitorFactory * factory,
419 return gst_structure_get_string ((GstStructure *) factory->metadata, key);
423 * gst_device_monitor_factory_get_metadata_keys:
424 * @factory: a #GstDeviceMonitorFactory
426 * Get the available keys for the metadata on @factory.
428 * Returns: (transfer full) (element-type utf8) (array zero-terminated=1):
429 * a %NULL-terminated array of key strings, or %NULL when there is no
430 * metadata. Free with g_strfreev() when no longer needed.
435 gst_device_monitor_factory_get_metadata_keys (GstDeviceMonitorFactory * factory)
437 GstStructure *metadata;
441 g_return_val_if_fail (GST_IS_DEVICE_MONITOR_FACTORY (factory), NULL);
443 metadata = (GstStructure *) factory->metadata;
444 if (metadata == NULL)
447 num = gst_structure_n_fields (metadata);
451 arr = g_new (gchar *, num + 1);
452 for (i = 0; i < num; ++i) {
453 arr[i] = g_strdup (gst_structure_nth_field_name (metadata, i));
460 * gst_device_monitor_factory_has_classesv:
461 * @factory: a #GstDeviceMonitorFactory
462 * @classes: a %NULL terminated array of klasses to match, only match if all
463 * classes are matched
465 * Check if @factory matches all of the given classes
467 * Returns: %TRUE if @factory matches.
472 gst_device_monitor_factory_has_classesv (GstDeviceMonitorFactory * factory,
477 g_return_val_if_fail (GST_IS_DEVICE_MONITOR_FACTORY (factory), FALSE);
479 klass = gst_device_monitor_factory_get_metadata (factory,
480 GST_ELEMENT_METADATA_KLASS);
483 GST_ERROR_OBJECT (factory,
484 "device monitor factory is missing klass identifiers");
488 for (; classes[0]; classes++) {
492 if (classes[0] == '\0')
495 found = strstr (klass, classes[0]);
499 if (found != klass && *(found - 1) != '/')
502 len = strlen (classes[0]);
503 if (found[len] != 0 && found[len] != '/')
511 * gst_device_monitor_factory_has_classes:
512 * @factory: a #GstDeviceMonitorFactory
513 * @classes: a "/" separate list of klasses to match, only match if all classes
516 * Check if @factory matches all of the given @classes
518 * Returns: %TRUE if @factory matches.
523 gst_device_monitor_factory_has_classes (GstDeviceMonitorFactory * factory,
524 const gchar * classes)
529 classesv = g_strsplit (classes, "/", 0);
531 res = gst_device_monitor_factory_has_classesv (factory, classesv);
533 g_strfreev (classesv);
545 device_monitor_filter (GstPluginFeature * feature, FilterData * data)
549 /* we only care about device monitor factories */
550 if (G_UNLIKELY (!GST_IS_DEVICE_MONITOR_FACTORY (feature)))
553 res = (gst_plugin_feature_get_rank (feature) >= data->minrank) &&
554 gst_device_monitor_factory_has_classes (GST_DEVICE_MONITOR_FACTORY_CAST
555 (feature), data->classes);
561 * gst_device_monitor_factory_list_get_device_monitors:
562 * @classes: a "/" separate list of klasses to match, only match if all classes
564 * @minrank: Minimum rank
566 * Get a list of factories that match all of the given @classes. Only
567 * device monitors with a rank greater or equal to @minrank will be
568 * returned. The list of factories is returned by decreasing rank.
570 * Returns: (transfer full) (element-type Gst.DeviceMonitorFactory): a #GList of
571 * #GstDeviceMonitorFactory device monitors. Use gst_plugin_feature_list_free() after
576 GList *gst_device_monitor_factory_list_get_device_monitors
577 (const gchar * classes, GstRank minrank)
583 data.classes = classes;
584 data.minrank = minrank;
586 /* get the feature list using the filter */
587 result = gst_registry_feature_filter (gst_registry_get (),
588 (GstPluginFeatureFilter) device_monitor_filter, FALSE, &data);
590 /* sort on rank and name */
591 result = g_list_sort (result, gst_plugin_feature_rank_compare_func);