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 * gstdeviceproviderfactory.c: GstDeviceProviderFactory 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:gstdeviceproviderfactory
26 * @title: GstDeviceProviderFactory
27 * @short_description: Create GstDeviceProviders from a factory
28 * @see_also: #GstDeviceProvider, #GstPlugin, #GstPluginFeature, #GstPadTemplate.
30 * #GstDeviceProviderFactory is used to create instances of device providers. A
31 * GstDeviceProviderfactory can be added to a #GstPlugin as it is also a
34 * Use the gst_device_provider_factory_find() and
35 * gst_device_provider_factory_get() functions to create device
36 * provider instances or use gst_device_provider_factory_get_by_name() as a
37 * convenient shortcut.
46 #include "gst_private.h"
48 #include "gstdeviceproviderfactory.h"
51 #include "glib-compat-private.h"
53 GST_DEBUG_CATEGORY_STATIC (device_provider_factory_debug);
54 #define GST_CAT_DEFAULT device_provider_factory_debug
56 static void gst_device_provider_factory_finalize (GObject * object);
57 static void gst_device_provider_factory_cleanup (GstDeviceProviderFactory *
60 /* static guint gst_device_provider_factory_signals[LAST_SIGNAL] = { 0 }; */
62 /* this is defined in gstelement.c */
63 extern GQuark __gst_deviceproviderclass_factory;
67 GST_DEBUG_CATEGORY_INIT (device_provider_factory_debug, "GST_DEVICE_PROVIDER_FACTORY", \
68 GST_DEBUG_BOLD | GST_DEBUG_FG_WHITE | GST_DEBUG_BG_RED, \
69 "device provider factories keep information about installed device providers"); \
72 G_DEFINE_TYPE_WITH_CODE (GstDeviceProviderFactory, gst_device_provider_factory,
73 GST_TYPE_PLUGIN_FEATURE, _do_init);
76 gst_device_provider_factory_class_init (GstDeviceProviderFactoryClass * klass)
78 GObjectClass *gobject_class = (GObjectClass *) klass;
80 gobject_class->finalize = gst_device_provider_factory_finalize;
84 gst_device_provider_factory_init (GstDeviceProviderFactory * factory)
89 gst_device_provider_factory_finalize (GObject * object)
91 GstDeviceProviderFactory *factory = GST_DEVICE_PROVIDER_FACTORY (object);
92 GstDeviceProvider *provider;
94 gst_device_provider_factory_cleanup (factory);
96 provider = g_atomic_pointer_get (&factory->provider);
98 gst_object_unref (provider);
100 G_OBJECT_CLASS (gst_device_provider_factory_parent_class)->finalize (object);
104 * gst_device_provider_factory_find:
105 * @name: name of factory to find
107 * Search for an device provider factory of the given name. Refs the returned
108 * device provider factory; caller is responsible for unreffing.
110 * Returns: (transfer full) (nullable): #GstDeviceProviderFactory if
111 * found, %NULL otherwise
115 GstDeviceProviderFactory *
116 gst_device_provider_factory_find (const gchar * name)
118 GstPluginFeature *feature;
120 g_return_val_if_fail (name != NULL, NULL);
122 feature = gst_registry_find_feature (gst_registry_get (), name,
123 GST_TYPE_DEVICE_PROVIDER_FACTORY);
125 return GST_DEVICE_PROVIDER_FACTORY (feature);
127 /* this isn't an error, for instance when you query if an device provider factory is
129 GST_LOG ("no such device provider factory \"%s\"", name);
135 gst_device_provider_factory_cleanup (GstDeviceProviderFactory * factory)
137 if (factory->metadata) {
138 gst_structure_free ((GstStructure *) factory->metadata);
139 factory->metadata = NULL;
142 factory->type = G_TYPE_INVALID;
146 #define CHECK_METADATA_FIELD(klass, name, key) \
148 const gchar *metafield = gst_device_provider_class_get_metadata (klass, key); \
149 if (G_UNLIKELY (metafield == NULL || *metafield == '\0')) { \
150 g_warning ("Device provider factory metadata for '%s' has no valid %s field", name, key); \
156 * gst_device_provider_register:
157 * @plugin: (allow-none): #GstPlugin to register the device provider with, or %NULL for
158 * a static device provider.
159 * @name: name of device providers of this type
160 * @rank: rank of device provider (higher rank means more importance when autoplugging)
161 * @type: GType of device provider to register
163 * Create a new device providerfactory capable of instantiating objects of the
164 * @type and add the factory to @plugin.
166 * Returns: %TRUE, if the registering succeeded, %FALSE on error
171 gst_device_provider_register (GstPlugin * plugin, const gchar * name,
172 guint rank, GType type)
174 GstPluginFeature *existing_feature;
175 GstRegistry *registry;
176 GstDeviceProviderFactory *factory;
177 GstDeviceProviderClass *klass;
179 g_return_val_if_fail (name != NULL, FALSE);
180 g_return_val_if_fail (g_type_is_a (type, GST_TYPE_DEVICE_PROVIDER), FALSE);
182 registry = gst_registry_get ();
184 /* check if feature already exists, if it exists there is no need to update it
185 * when the registry is getting updated, outdated plugins and all their
186 * features are removed and readded.
188 existing_feature = gst_registry_lookup_feature (registry, name);
189 if (existing_feature) {
190 GST_DEBUG_OBJECT (registry, "update existing feature %p (%s)",
191 existing_feature, name);
192 factory = GST_DEVICE_PROVIDER_FACTORY_CAST (existing_feature);
193 factory->type = type;
194 existing_feature->loaded = TRUE;
195 g_type_set_qdata (type, __gst_deviceproviderclass_factory, factory);
196 gst_object_unref (existing_feature);
200 factory = g_object_new (GST_TYPE_DEVICE_PROVIDER_FACTORY, NULL);
201 gst_plugin_feature_set_name (GST_PLUGIN_FEATURE_CAST (factory), name);
202 GST_LOG_OBJECT (factory, "Created new device providerfactory for type %s",
205 /* provide info needed during class structure setup */
206 g_type_set_qdata (type, __gst_deviceproviderclass_factory, factory);
207 klass = GST_DEVICE_PROVIDER_CLASS (g_type_class_ref (type));
209 CHECK_METADATA_FIELD (klass, name, GST_ELEMENT_METADATA_LONGNAME);
210 CHECK_METADATA_FIELD (klass, name, GST_ELEMENT_METADATA_KLASS);
211 CHECK_METADATA_FIELD (klass, name, GST_ELEMENT_METADATA_DESCRIPTION);
212 CHECK_METADATA_FIELD (klass, name, GST_ELEMENT_METADATA_AUTHOR);
214 factory->type = type;
215 factory->metadata = gst_structure_copy ((GstStructure *) klass->metadata);
217 if (plugin && plugin->desc.name) {
218 GST_PLUGIN_FEATURE_CAST (factory)->plugin_name = plugin->desc.name;
219 GST_PLUGIN_FEATURE_CAST (factory)->plugin = plugin;
220 g_object_add_weak_pointer ((GObject *) plugin,
221 (gpointer *) & GST_PLUGIN_FEATURE_CAST (factory)->plugin);
223 GST_PLUGIN_FEATURE_CAST (factory)->plugin_name = "NULL";
224 GST_PLUGIN_FEATURE_CAST (factory)->plugin = NULL;
226 gst_plugin_feature_set_rank (GST_PLUGIN_FEATURE_CAST (factory), rank);
227 GST_PLUGIN_FEATURE_CAST (factory)->loaded = TRUE;
229 gst_registry_add_feature (registry, GST_PLUGIN_FEATURE_CAST (factory));
236 gst_device_provider_factory_cleanup (factory);
242 * gst_device_provider_factory_get:
243 * @factory: factory to instantiate
245 * Returns the device provider of the type defined by the given device
248 * Returns: (transfer full) (nullable): the #GstDeviceProvider or %NULL
249 * if the device provider couldn't be created
254 gst_device_provider_factory_get (GstDeviceProviderFactory * factory)
256 GstDeviceProvider *device_provider;
257 GstDeviceProviderClass *oclass;
258 GstDeviceProviderFactory *newfactory;
260 g_return_val_if_fail (factory != NULL, NULL);
263 GST_DEVICE_PROVIDER_FACTORY (gst_plugin_feature_load (GST_PLUGIN_FEATURE
266 if (newfactory == NULL)
269 factory = newfactory;
271 GST_INFO ("getting device provider \"%s\"", GST_OBJECT_NAME (factory));
273 if (factory->type == 0)
276 device_provider = g_atomic_pointer_get (&newfactory->provider);
277 if (device_provider) {
278 gst_object_unref (factory);
279 return gst_object_ref (device_provider);
282 /* create an instance of the device provider, cast so we don't assert on NULL
283 * also set name as early as we can
285 device_provider = g_object_new (factory->type, NULL);
286 if (G_UNLIKELY (device_provider == NULL))
287 goto no_device_provider;
289 /* fill in the pointer to the factory in the device provider class. The
290 * class will not be unreffed currently.
291 * Be thread safe as there might be 2 threads creating the first instance of
292 * an device provider at the same moment
294 oclass = GST_DEVICE_PROVIDER_GET_CLASS (device_provider);
295 if (!g_atomic_pointer_compare_and_exchange (&oclass->factory, NULL, factory)) {
296 gst_object_unref (factory);
298 /* This ref will never be dropped as the class is never destroyed */
299 GST_OBJECT_FLAG_SET (factory, GST_OBJECT_FLAG_MAY_BE_LEAKED);
302 gst_object_ref_sink (device_provider);
304 /* We use an atomic to make sure we don't create two in parallel */
305 if (!g_atomic_pointer_compare_and_exchange (&newfactory->provider, NULL,
307 gst_object_unref (device_provider);
309 device_provider = g_atomic_pointer_get (&newfactory->provider);
312 GST_DEBUG ("created device provider \"%s\"", GST_OBJECT_NAME (factory));
314 return gst_object_ref (device_provider);
319 GST_WARNING_OBJECT (factory,
320 "loading plugin containing feature %s returned NULL!",
321 GST_OBJECT_NAME (factory));
326 GST_WARNING_OBJECT (factory, "factory has no type");
327 gst_object_unref (factory);
332 GST_WARNING_OBJECT (factory, "could not create device provider");
333 gst_object_unref (factory);
339 * gst_device_provider_factory_get_by_name:
340 * @factoryname: a named factory to instantiate
342 * Returns the device provider of the type defined by the given device
345 * Returns: (transfer full) (nullable): a #GstDeviceProvider or %NULL
346 * if unable to create device provider
351 gst_device_provider_factory_get_by_name (const gchar * factoryname)
353 GstDeviceProviderFactory *factory;
354 GstDeviceProvider *device_provider;
356 g_return_val_if_fail (factoryname != NULL, NULL);
357 g_return_val_if_fail (gst_is_initialized (), NULL);
359 GST_LOG ("gstdeviceproviderfactory: get_by_name \"%s\"", factoryname);
361 factory = gst_device_provider_factory_find (factoryname);
365 GST_LOG_OBJECT (factory, "found factory %p", factory);
366 device_provider = gst_device_provider_factory_get (factory);
367 if (device_provider == NULL)
370 gst_object_unref (factory);
371 return device_provider;
376 GST_INFO ("no such device provider factory \"%s\"!", factoryname);
381 GST_INFO_OBJECT (factory, "couldn't create instance!");
382 gst_object_unref (factory);
388 * gst_device_provider_factory_get_device_provider_type:
389 * @factory: factory to get managed #GType from
391 * Get the #GType for device providers managed by this factory. The type can
392 * only be retrieved if the device provider factory is loaded, which can be
393 * assured with gst_plugin_feature_load().
395 * Returns: the #GType for device providers managed by this factory.
400 gst_device_provider_factory_get_device_provider_type (GstDeviceProviderFactory *
403 g_return_val_if_fail (GST_IS_DEVICE_PROVIDER_FACTORY (factory),
406 return factory->type;
410 * gst_device_provider_factory_get_metadata:
411 * @factory: a #GstDeviceProviderFactory
414 * Get the metadata on @factory with @key.
416 * Returns: (nullable): the metadata with @key on @factory or %NULL
417 * when there was no metadata with the given @key.
422 gst_device_provider_factory_get_metadata (GstDeviceProviderFactory * factory,
425 return gst_structure_get_string ((GstStructure *) factory->metadata, key);
429 * gst_device_provider_factory_get_metadata_keys:
430 * @factory: a #GstDeviceProviderFactory
432 * Get the available keys for the metadata on @factory.
434 * Returns: (transfer full) (element-type utf8) (array zero-terminated=1) (nullable):
435 * a %NULL-terminated array of key strings, or %NULL when there is no
436 * metadata. Free with g_strfreev() when no longer needed.
441 gst_device_provider_factory_get_metadata_keys (GstDeviceProviderFactory *
444 GstStructure *metadata;
448 g_return_val_if_fail (GST_IS_DEVICE_PROVIDER_FACTORY (factory), NULL);
450 metadata = (GstStructure *) factory->metadata;
451 if (metadata == NULL)
454 num = gst_structure_n_fields (metadata);
458 arr = g_new (gchar *, num + 1);
459 for (i = 0; i < num; ++i) {
460 arr[i] = g_strdup (gst_structure_nth_field_name (metadata, i));
467 * gst_device_provider_factory_has_classesv:
468 * @factory: a #GstDeviceProviderFactory
469 * @classes: (array zero-terminated=1) (allow-none): a %NULL terminated array
470 * of classes to match, only match if all classes are matched
472 * Check if @factory matches all of the given classes
474 * Returns: %TRUE if @factory matches.
479 gst_device_provider_factory_has_classesv (GstDeviceProviderFactory * factory,
484 g_return_val_if_fail (GST_IS_DEVICE_PROVIDER_FACTORY (factory), FALSE);
486 klass = gst_device_provider_factory_get_metadata (factory,
487 GST_ELEMENT_METADATA_KLASS);
490 GST_ERROR_OBJECT (factory,
491 "device provider factory is missing klass identifiers");
495 for (; classes != NULL && classes[0] != NULL; classes++) {
499 if (classes[0][0] == '\0')
502 found = strstr (klass, classes[0]);
506 if (found != klass && *(found - 1) != '/')
509 len = strlen (classes[0]);
510 if (found[len] != 0 && found[len] != '/')
518 * gst_device_provider_factory_has_classes:
519 * @factory: a #GstDeviceProviderFactory
520 * @classes: (allow-none): a "/" separate list of classes to match, only match
521 * if all classes are matched
523 * Check if @factory matches all of the given @classes
525 * Returns: %TRUE if @factory matches or if @classes is %NULL.
530 gst_device_provider_factory_has_classes (GstDeviceProviderFactory * factory,
531 const gchar * classes)
539 classesv = g_strsplit (classes, "/", 0);
541 res = gst_device_provider_factory_has_classesv (factory, classesv);
543 g_strfreev (classesv);
549 device_provider_filter (GstPluginFeature * feature, GstRank * minrank)
551 /* we only care about device provider factories */
552 if (G_UNLIKELY (!GST_IS_DEVICE_PROVIDER_FACTORY (feature)))
555 return (gst_plugin_feature_get_rank (feature) >= *minrank);
559 * gst_device_provider_factory_list_get_device_providers:
560 * @minrank: Minimum rank
562 * Get a list of factories with a rank greater or equal to @minrank.
563 * The list of factories is returned by decreasing rank.
565 * Returns: (transfer full) (element-type Gst.DeviceProviderFactory):
566 * a #GList of #GstDeviceProviderFactory device providers. Use
567 * gst_plugin_feature_list_free() after usage.
572 gst_device_provider_factory_list_get_device_providers (GstRank minrank)
576 /* get the feature list using the filter */
577 result = gst_registry_feature_filter (gst_registry_get (),
578 (GstPluginFeatureFilter) device_provider_filter, FALSE, &minrank);
580 /* sort on rank and name */
581 result = g_list_sort (result, gst_plugin_feature_rank_compare_func);