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 * gstelementfactory.c: GstElementFactory 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., 51 Franklin St, Fifth Floor,
21 * Boston, MA 02110-1301, USA.
25 * SECTION:gstelementfactory
26 * @short_description: Create GstElements from a factory
27 * @see_also: #GstElement, #GstPlugin, #GstPluginFeature, #GstPadTemplate.
29 * #GstElementFactory is used to create instances of elements. A
30 * GstElementfactory can be added to a #GstPlugin as it is also a
33 * Use the gst_element_factory_find() and gst_element_factory_create()
34 * functions to create element instances or use gst_element_factory_make() as a
35 * convenient shortcut.
37 * The following code example shows you how to create a GstFileSrc element.
40 * <title>Using an element factory</title>
41 * <programlisting language="c">
42 * #include <gst/gst.h>
45 * GstElementFactory *srcfactory;
47 * gst_init (&argc, &argv);
49 * srcfactory = gst_element_factory_find ("filesrc");
50 * g_return_if_fail (srcfactory != NULL);
51 * src = gst_element_factory_create (srcfactory, "src");
52 * g_return_if_fail (src != NULL);
57 * Last reviewed on 2005-11-23 (0.9.5)
60 #include "gst_private.h"
62 #include "gstelement.h"
63 #include "gstelementmetadata.h"
66 #include "gstregistry.h"
69 #include "glib-compat-private.h"
71 GST_DEBUG_CATEGORY_STATIC (element_factory_debug);
72 #define GST_CAT_DEFAULT element_factory_debug
74 static void gst_element_factory_finalize (GObject * object);
75 static void gst_element_factory_cleanup (GstElementFactory * factory);
77 /* static guint gst_element_factory_signals[LAST_SIGNAL] = { 0 }; */
79 /* this is defined in gstelement.c */
80 extern GQuark __gst_elementclass_factory;
84 GST_DEBUG_CATEGORY_INIT (element_factory_debug, "GST_ELEMENT_FACTORY", \
85 GST_DEBUG_BOLD | GST_DEBUG_FG_WHITE | GST_DEBUG_BG_RED, \
86 "element factories keep information about installed elements"); \
89 G_DEFINE_TYPE_WITH_CODE (GstElementFactory, gst_element_factory,
90 GST_TYPE_PLUGIN_FEATURE, _do_init);
93 gst_element_factory_class_init (GstElementFactoryClass * klass)
95 GObjectClass *gobject_class = (GObjectClass *) klass;
97 gobject_class->finalize = gst_element_factory_finalize;
101 gst_element_factory_init (GstElementFactory * factory)
103 factory->staticpadtemplates = NULL;
104 factory->numpadtemplates = 0;
106 factory->uri_type = GST_URI_UNKNOWN;
107 factory->uri_protocols = NULL;
109 factory->interfaces = NULL;
113 gst_element_factory_finalize (GObject * object)
115 GstElementFactory *factory = GST_ELEMENT_FACTORY (object);
117 gst_element_factory_cleanup (factory);
118 G_OBJECT_CLASS (gst_element_factory_parent_class)->finalize (object);
122 * gst_element_factory_find:
123 * @name: name of factory to find
125 * Search for an element factory of the given name. Refs the returned
126 * element factory; caller is responsible for unreffing.
128 * Returns: (transfer full): #GstElementFactory if found, NULL otherwise
131 gst_element_factory_find (const gchar * name)
133 GstPluginFeature *feature;
135 g_return_val_if_fail (name != NULL, NULL);
137 feature = gst_registry_find_feature (gst_registry_get (), name,
138 GST_TYPE_ELEMENT_FACTORY);
140 return GST_ELEMENT_FACTORY (feature);
142 /* this isn't an error, for instance when you query if an element factory is
144 GST_LOG ("no such element factory \"%s\"", name);
149 gst_element_factory_cleanup (GstElementFactory * factory)
153 if (factory->metadata) {
154 gst_structure_free ((GstStructure *) factory->metadata);
155 factory->metadata = NULL;
158 factory->type = G_TYPE_INVALID;
161 for (item = factory->staticpadtemplates; item; item = item->next) {
162 GstStaticPadTemplate *templ = item->data;
164 gst_static_caps_cleanup (&templ->static_caps);
165 g_slice_free (GstStaticPadTemplate, templ);
167 g_list_free (factory->staticpadtemplates);
168 factory->staticpadtemplates = NULL;
169 factory->numpadtemplates = 0;
170 factory->uri_type = GST_URI_UNKNOWN;
171 if (factory->uri_protocols) {
172 g_strfreev (factory->uri_protocols);
173 factory->uri_protocols = NULL;
176 g_list_free (factory->interfaces);
177 factory->interfaces = NULL;
180 #define CHECK_METADATA_FIELD(klass, name, key) \
182 const gchar *metafield = gst_element_class_get_metadata (klass, key); \
183 if (G_UNLIKELY (metafield == NULL || *metafield == '\0')) { \
184 g_warning ("Element factory metadata for '%s' has no valid %s field", name, key); \
190 * gst_element_register:
191 * @plugin: (allow-none): #GstPlugin to register the element with, or NULL for
193 * @name: name of elements of this type
194 * @rank: rank of element (higher rank means more importance when autoplugging)
195 * @type: GType of element to register
197 * Create a new elementfactory capable of instantiating objects of the
198 * @type and add the factory to @plugin.
200 * Returns: TRUE, if the registering succeeded, FALSE on error
203 gst_element_register (GstPlugin * plugin, const gchar * name, guint rank,
206 GstPluginFeature *existing_feature;
207 GstRegistry *registry;
208 GstElementFactory *factory;
210 guint n_interfaces, i;
211 GstElementClass *klass;
214 g_return_val_if_fail (name != NULL, FALSE);
215 g_return_val_if_fail (g_type_is_a (type, GST_TYPE_ELEMENT), FALSE);
217 registry = gst_registry_get ();
219 /* check if feature already exists, if it exists there is no need to update it
220 * when the registry is getting updated, outdated plugins and all their
221 * features are removed and readded.
223 existing_feature = gst_registry_lookup_feature (registry, name);
224 if (existing_feature) {
225 GST_DEBUG_OBJECT (registry, "update existing feature %p (%s)",
226 existing_feature, name);
227 factory = GST_ELEMENT_FACTORY_CAST (existing_feature);
228 factory->type = type;
229 existing_feature->loaded = TRUE;
230 g_type_set_qdata (type, __gst_elementclass_factory, factory);
231 gst_object_unref (existing_feature);
236 GST_ELEMENT_FACTORY_CAST (g_object_newv (GST_TYPE_ELEMENT_FACTORY, 0,
238 gst_plugin_feature_set_name (GST_PLUGIN_FEATURE_CAST (factory), name);
239 GST_LOG_OBJECT (factory, "Created new elementfactory for type %s",
242 /* provide info needed during class structure setup */
243 g_type_set_qdata (type, __gst_elementclass_factory, factory);
244 klass = GST_ELEMENT_CLASS (g_type_class_ref (type));
246 CHECK_METADATA_FIELD (klass, name, GST_ELEMENT_METADATA_LONGNAME);
247 CHECK_METADATA_FIELD (klass, name, GST_ELEMENT_METADATA_KLASS);
248 CHECK_METADATA_FIELD (klass, name, GST_ELEMENT_METADATA_DESCRIPTION);
249 CHECK_METADATA_FIELD (klass, name, GST_ELEMENT_METADATA_AUTHOR);
251 factory->type = type;
252 factory->metadata = gst_structure_copy ((GstStructure *) klass->metadata);
254 for (item = klass->padtemplates; item; item = item->next) {
255 GstPadTemplate *templ = item->data;
256 GstStaticPadTemplate *newt;
257 gchar *caps_string = gst_caps_to_string (templ->caps);
259 newt = g_slice_new (GstStaticPadTemplate);
260 newt->name_template = g_intern_string (templ->name_template);
261 newt->direction = templ->direction;
262 newt->presence = templ->presence;
263 newt->static_caps.caps = NULL;
264 newt->static_caps.string = g_intern_string (caps_string);
265 factory->staticpadtemplates =
266 g_list_append (factory->staticpadtemplates, newt);
268 g_free (caps_string);
270 factory->numpadtemplates = klass->numpadtemplates;
272 /* special stuff for URI handling */
273 if (g_type_is_a (type, GST_TYPE_URI_HANDLER)) {
274 GstURIHandlerInterface *iface = (GstURIHandlerInterface *)
275 g_type_interface_peek (klass, GST_TYPE_URI_HANDLER);
277 if (!iface || !iface->get_type || !iface->get_protocols)
280 factory->uri_type = iface->get_type (factory->type);
281 if (!GST_URI_TYPE_IS_VALID (factory->uri_type))
283 if (iface->get_protocols) {
284 const gchar *const *protocols;
286 protocols = iface->get_protocols (factory->type);
287 factory->uri_protocols = g_strdupv ((gchar **) protocols);
289 if (!factory->uri_protocols)
293 interfaces = g_type_interfaces (type, &n_interfaces);
294 for (i = 0; i < n_interfaces; i++) {
295 __gst_element_factory_add_interface (factory, g_type_name (interfaces[i]));
299 if (plugin && plugin->desc.name) {
300 GST_PLUGIN_FEATURE_CAST (factory)->plugin_name = plugin->desc.name;
301 GST_PLUGIN_FEATURE_CAST (factory)->plugin = plugin;
302 g_object_add_weak_pointer ((GObject *) plugin,
303 (gpointer *) & GST_PLUGIN_FEATURE_CAST (factory)->plugin);
305 GST_PLUGIN_FEATURE_CAST (factory)->plugin_name = "NULL";
306 GST_PLUGIN_FEATURE_CAST (factory)->plugin = NULL;
308 gst_plugin_feature_set_rank (GST_PLUGIN_FEATURE_CAST (factory), rank);
309 GST_PLUGIN_FEATURE_CAST (factory)->loaded = TRUE;
311 gst_registry_add_feature (registry, GST_PLUGIN_FEATURE_CAST (factory));
318 GST_WARNING_OBJECT (factory, "error with uri handler!");
319 gst_element_factory_cleanup (factory);
325 gst_element_factory_cleanup (factory);
331 * gst_element_factory_create:
332 * @factory: factory to instantiate
333 * @name: (allow-none): name of new element, or NULL to automatically create
336 * Create a new element of the type defined by the given elementfactory.
337 * It will be given the name supplied, since all elements require a name as
338 * their first argument.
340 * Returns: (transfer floating): new #GstElement or NULL if the element couldn't
344 gst_element_factory_create (GstElementFactory * factory, const gchar * name)
347 GstElementClass *oclass;
348 GstElementFactory *newfactory;
350 g_return_val_if_fail (factory != NULL, NULL);
353 GST_ELEMENT_FACTORY (gst_plugin_feature_load (GST_PLUGIN_FEATURE
356 if (newfactory == NULL)
359 factory = newfactory;
362 GST_INFO ("creating element \"%s\" named \"%s\"",
363 GST_OBJECT_NAME (factory), GST_STR_NULL (name));
365 GST_INFO ("creating element \"%s\"", GST_OBJECT_NAME (factory));
367 if (factory->type == 0)
370 /* create an instance of the element, cast so we don't assert on NULL
371 * also set name as early as we can
375 GST_ELEMENT_CAST (g_object_new (factory->type, "name", name, NULL));
377 element = GST_ELEMENT_CAST (g_object_newv (factory->type, 0, NULL));
378 if (G_UNLIKELY (element == NULL))
381 /* fill in the pointer to the factory in the element class. The
382 * class will not be unreffed currently.
383 * Be thread safe as there might be 2 threads creating the first instance of
384 * an element at the same moment
386 oclass = GST_ELEMENT_GET_CLASS (element);
387 if (!g_atomic_pointer_compare_and_exchange (&oclass->elementfactory, NULL,
389 gst_object_unref (factory);
391 GST_DEBUG ("created element \"%s\"", GST_OBJECT_NAME (factory));
398 GST_WARNING_OBJECT (factory,
399 "loading plugin containing feature %s returned NULL!", name);
404 GST_WARNING_OBJECT (factory, "factory has no type");
405 gst_object_unref (factory);
410 GST_WARNING_OBJECT (factory, "could not create element");
411 gst_object_unref (factory);
417 * gst_element_factory_make:
418 * @factoryname: a named factory to instantiate
419 * @name: (allow-none): name of new element, or NULL to automatically create
422 * Create a new element of the type defined by the given element factory.
423 * If name is NULL, then the element will receive a guaranteed unique name,
424 * consisting of the element factory name and a number.
425 * If name is given, it will be given the name supplied.
427 * Returns: (transfer floating): new #GstElement or NULL if unable to create element
430 gst_element_factory_make (const gchar * factoryname, const gchar * name)
432 GstElementFactory *factory;
435 g_return_val_if_fail (factoryname != NULL, NULL);
436 g_return_val_if_fail (gst_is_initialized (), NULL);
438 GST_LOG ("gstelementfactory: make \"%s\" \"%s\"",
439 factoryname, GST_STR_NULL (name));
441 factory = gst_element_factory_find (factoryname);
445 GST_LOG_OBJECT (factory, "found factory %p", factory);
446 element = gst_element_factory_create (factory, name);
450 gst_object_unref (factory);
456 GST_INFO ("no such element factory \"%s\"!", factoryname);
461 GST_INFO_OBJECT (factory, "couldn't create instance!");
462 gst_object_unref (factory);
468 __gst_element_factory_add_static_pad_template (GstElementFactory * factory,
469 GstStaticPadTemplate * templ)
471 g_return_if_fail (factory != NULL);
472 g_return_if_fail (templ != NULL);
474 factory->staticpadtemplates =
475 g_list_append (factory->staticpadtemplates, templ);
476 factory->numpadtemplates++;
480 * gst_element_factory_get_element_type:
481 * @factory: factory to get managed #GType from
483 * Get the #GType for elements managed by this factory. The type can
484 * only be retrieved if the element factory is loaded, which can be
485 * assured with gst_plugin_feature_load().
487 * Returns: the #GType for elements managed by this factory or 0 if
488 * the factory is not loaded.
491 gst_element_factory_get_element_type (GstElementFactory * factory)
493 g_return_val_if_fail (GST_IS_ELEMENT_FACTORY (factory), 0);
495 return factory->type;
499 * gst_element_factory_get_metadata:
500 * @factory: a #GstElementFactory
503 * Get the metadata on @factory with @key.
505 * Returns: the metadata with @key on @factory or %NULL when there was no
506 * metadata with the given @key.
509 gst_element_factory_get_metadata (GstElementFactory * factory,
512 return gst_structure_get_string ((GstStructure *) factory->metadata, key);
516 * gst_element_factory_get_metadata_keys:
517 * @factory: a #GstElementFactory
519 * Get the available keys for the metadata on @factory.
521 * Returns: (transfer full) (element-type utf8) (array zero-terminated=1):
522 * a %NULL-terminated array of key strings, or %NULL when there is no
523 * metadata. Free with g_strfreev() when no longer needed.
526 gst_element_factory_get_metadata_keys (GstElementFactory * factory)
528 GstStructure *metadata;
532 g_return_val_if_fail (GST_IS_ELEMENT_FACTORY (factory), NULL);
534 metadata = (GstStructure *) factory->metadata;
535 if (metadata == NULL)
538 num = gst_structure_n_fields (metadata);
542 arr = g_new (gchar *, num + 1);
543 for (i = 0; i < num; ++i) {
544 arr[i] = g_strdup (gst_structure_nth_field_name (metadata, i));
551 * gst_element_factory_get_num_pad_templates:
552 * @factory: a #GstElementFactory
554 * Gets the number of pad_templates in this factory.
556 * Returns: the number of pad_templates
559 gst_element_factory_get_num_pad_templates (GstElementFactory * factory)
561 g_return_val_if_fail (GST_IS_ELEMENT_FACTORY (factory), 0);
563 return factory->numpadtemplates;
567 * __gst_element_factory_add_interface:
568 * @elementfactory: The elementfactory to add the interface to
569 * @interfacename: Name of the interface
571 * Adds the given interfacename to the list of implemented interfaces of the
575 __gst_element_factory_add_interface (GstElementFactory * elementfactory,
576 const gchar * interfacename)
578 g_return_if_fail (GST_IS_ELEMENT_FACTORY (elementfactory));
579 g_return_if_fail (interfacename != NULL);
580 g_return_if_fail (interfacename[0] != '\0'); /* no empty string */
582 elementfactory->interfaces =
583 g_list_prepend (elementfactory->interfaces,
584 (gpointer) g_intern_string (interfacename));
588 * gst_element_factory_get_static_pad_templates:
589 * @factory: a #GstElementFactory
591 * Gets the #GList of #GstStaticPadTemplate for this factory.
593 * Returns: (transfer none) (element-type Gst.StaticPadTemplate): the
594 * static pad templates
597 gst_element_factory_get_static_pad_templates (GstElementFactory * factory)
599 g_return_val_if_fail (GST_IS_ELEMENT_FACTORY (factory), NULL);
601 return factory->staticpadtemplates;
605 * gst_element_factory_get_uri_type:
606 * @factory: a #GstElementFactory
608 * Gets the type of URIs the element supports or #GST_URI_UNKNOWN if none.
610 * Returns: type of URIs this element supports
613 gst_element_factory_get_uri_type (GstElementFactory * factory)
615 g_return_val_if_fail (GST_IS_ELEMENT_FACTORY (factory), GST_URI_UNKNOWN);
617 return factory->uri_type;
621 * gst_element_factory_get_uri_protocols:
622 * @factory: a #GstElementFactory
624 * Gets a NULL-terminated array of protocols this element supports or NULL if
625 * no protocols are supported. You may not change the contents of the returned
626 * array, as it is still owned by the element factory. Use g_strdupv() to
627 * make a copy of the protocol string array if you need to.
629 * Returns: (transfer none) (array zero-terminated=1): the supported protocols
633 gst_element_factory_get_uri_protocols (GstElementFactory * factory)
635 g_return_val_if_fail (GST_IS_ELEMENT_FACTORY (factory), NULL);
637 return (const gchar * const *) factory->uri_protocols;
641 * gst_element_factory_has_interface:
642 * @factory: a #GstElementFactory
643 * @interfacename: an interface name
645 * Check if @factory implements the interface with name @interfacename.
647 * Returns: #TRUE when @factory implement the interface.
650 gst_element_factory_has_interface (GstElementFactory * factory,
651 const gchar * interfacename)
655 g_return_val_if_fail (GST_IS_ELEMENT_FACTORY (factory), FALSE);
657 for (walk = factory->interfaces; walk; walk = g_list_next (walk)) {
658 gchar *iname = (gchar *) walk->data;
660 if (!strcmp (iname, interfacename))
669 GstElementFactoryListType type;
675 * gst_element_factory_list_is_type:
676 * @factory: a #GstElementFactory
677 * @type: a #GstElementFactoryListType
679 * Check if @factory is of the given types.
681 * Returns: %TRUE if @factory is of @type.
684 gst_element_factory_list_is_type (GstElementFactory * factory,
685 GstElementFactoryListType type)
687 gboolean res = FALSE;
691 gst_element_factory_get_metadata (factory, GST_ELEMENT_METADATA_KLASS);
694 GST_ERROR_OBJECT (factory, "element factory is missing klass identifiers");
698 /* Filter by element type first, as soon as it matches
699 * one type, we skip all other tests */
700 if (!res && (type & GST_ELEMENT_FACTORY_TYPE_SINK))
701 res = (strstr (klass, "Sink") != NULL);
703 if (!res && (type & GST_ELEMENT_FACTORY_TYPE_SRC))
704 res = (strstr (klass, "Source") != NULL);
706 if (!res && (type & GST_ELEMENT_FACTORY_TYPE_DECODER))
707 res = (strstr (klass, "Decoder") != NULL);
709 if (!res && (type & GST_ELEMENT_FACTORY_TYPE_ENCODER))
710 res = (strstr (klass, "Encoder") != NULL);
712 if (!res && (type & GST_ELEMENT_FACTORY_TYPE_MUXER))
713 res = (strstr (klass, "Muxer") != NULL);
715 if (!res && (type & GST_ELEMENT_FACTORY_TYPE_DEMUXER))
716 res = (strstr (klass, "Demux") != NULL);
718 /* FIXME : We're actually parsing two Classes here... */
719 if (!res && (type & GST_ELEMENT_FACTORY_TYPE_PARSER))
720 res = ((strstr (klass, "Parser") != NULL)
721 && (strstr (klass, "Codec") != NULL));
723 if (!res && (type & GST_ELEMENT_FACTORY_TYPE_DEPAYLOADER))
724 res = (strstr (klass, "Depayloader") != NULL);
726 if (!res && (type & GST_ELEMENT_FACTORY_TYPE_PAYLOADER))
727 res = (strstr (klass, "Payloader") != NULL);
729 if (!res && (type & GST_ELEMENT_FACTORY_TYPE_FORMATTER))
730 res = (strstr (klass, "Formatter") != NULL);
732 /* Filter by media type now, we only test if it
733 * matched any of the types above. */
735 && (type & (GST_ELEMENT_FACTORY_TYPE_MEDIA_AUDIO |
736 GST_ELEMENT_FACTORY_TYPE_MEDIA_VIDEO |
737 GST_ELEMENT_FACTORY_TYPE_MEDIA_IMAGE)))
738 res = ((type & GST_ELEMENT_FACTORY_TYPE_MEDIA_AUDIO)
739 && (strstr (klass, "Audio") != NULL))
740 || ((type & GST_ELEMENT_FACTORY_TYPE_MEDIA_VIDEO)
741 && (strstr (klass, "Video") != NULL))
742 || ((type & GST_ELEMENT_FACTORY_TYPE_MEDIA_IMAGE)
743 && (strstr (klass, "Image") != NULL));
749 element_filter (GstPluginFeature * feature, FilterData * data)
753 /* we only care about element factories */
754 if (G_UNLIKELY (!GST_IS_ELEMENT_FACTORY (feature)))
757 res = (gst_plugin_feature_get_rank (feature) >= data->minrank) &&
758 gst_element_factory_list_is_type (GST_ELEMENT_FACTORY_CAST (feature),
765 * gst_element_factory_list_get_elements:
766 * @type: a #GstElementFactoryListType
767 * @minrank: Minimum rank
769 * Get a list of factories that match the given @type. Only elements
770 * with a rank greater or equal to @minrank will be returned.
771 * The list of factories is returned by decreasing rank.
773 * Returns: (transfer full) (element-type Gst.ElementFactory): a #GList of
774 * #GstElementFactory elements. Use gst_plugin_feature_list_free() after
778 gst_element_factory_list_get_elements (GstElementFactoryListType type,
786 data.minrank = minrank;
788 /* get the feature list using the filter */
789 result = gst_registry_feature_filter (gst_registry_get (),
790 (GstPluginFeatureFilter) element_filter, FALSE, &data);
792 /* sort on rank and name */
793 result = g_list_sort (result, gst_plugin_feature_rank_compare_func);
799 * gst_element_factory_list_filter:
800 * @list: (transfer none) (element-type Gst.ElementFactory): a #GList of
801 * #GstElementFactory to filter
803 * @direction: a #GstPadDirection to filter on
804 * @subsetonly: whether to filter on caps subsets or not.
806 * Filter out all the elementfactories in @list that can handle @caps in
807 * the given direction.
809 * If @subsetonly is %TRUE, then only the elements whose pads templates
810 * are a complete superset of @caps will be returned. Else any element
811 * whose pad templates caps can intersect with @caps will be returned.
813 * Returns: (transfer full) (element-type Gst.ElementFactory): a #GList of
814 * #GstElementFactory elements that match the given requisits.
815 * Use #gst_plugin_feature_list_free after usage.
818 gst_element_factory_list_filter (GList * list,
819 const GstCaps * caps, GstPadDirection direction, gboolean subsetonly)
821 GQueue results = G_QUEUE_INIT;
823 GST_DEBUG ("finding factories");
825 /* loop over all the factories */
826 for (; list; list = list->next) {
827 GstElementFactory *factory;
828 const GList *templates;
831 factory = (GstElementFactory *) list->data;
833 GST_DEBUG ("Trying %s",
834 gst_plugin_feature_get_name ((GstPluginFeature *) factory));
836 /* get the templates from the element factory */
837 templates = gst_element_factory_get_static_pad_templates (factory);
838 for (walk = (GList *) templates; walk; walk = g_list_next (walk)) {
839 GstStaticPadTemplate *templ = walk->data;
841 /* we only care about the sink templates */
842 if (templ->direction == direction) {
845 /* try to intersect the caps with the caps of the template */
846 tmpl_caps = gst_static_caps_get (&templ->static_caps);
848 /* FIXME, intersect is not the right method, we ideally want to check
849 * for a subset here */
851 /* check if the intersection is empty */
852 if ((subsetonly && gst_caps_is_subset (caps, tmpl_caps)) ||
853 (!subsetonly && gst_caps_can_intersect (caps, tmpl_caps))) {
854 /* non empty intersection, we can use this element */
855 g_queue_push_tail (&results, gst_object_ref (factory));
856 gst_caps_unref (tmpl_caps);
859 gst_caps_unref (tmpl_caps);