2 * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
3 * 2000 Wim Taymans <wtay@chello.be>
5 * gstelement.c: The base element, all elements derive from this
7 * This library is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Library General Public
9 * License as published by the Free Software Foundation; either
10 * version 2 of the License, or (at your option) any later version.
12 * This library is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Library General Public License for more details.
17 * You should have received a copy of the GNU Library General Public
18 * License along with this library; if not, write to the
19 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
20 * Boston, MA 02111-1307, USA.
23 //#define GST_DEBUG_ENABLED
24 #include "gst_private.h"
26 #include "gstelement.h"
27 #include "gstextratypes.h"
29 #include "gstscheduler.h"
32 /* Element signals and args */
50 static void gst_element_class_init (GstElementClass *klass);
51 static void gst_element_init (GstElement *element);
52 static void gst_element_base_class_init (GstElementClass *klass);
54 static void gst_element_set_property (GObject *object, guint prop_id, const GValue *value, GParamSpec *pspec);
55 static void gst_element_get_property (GObject *object, guint prop_id, GValue *value, GParamSpec *pspec);
57 static void gst_element_shutdown (GObject *object);
58 static void gst_element_real_destroy (GObject *object);
60 static GstElementStateReturn gst_element_change_state (GstElement *element);
62 #ifndef GST_DISABLE_LOADSAVE
63 static xmlNodePtr gst_element_save_thyself (GstObject *object, xmlNodePtr parent);
64 GstElement* gst_element_restore_thyself (xmlNodePtr self, GstObject *parent);
67 static GstObjectClass *parent_class = NULL;
68 static guint gst_element_signals[LAST_SIGNAL] = { 0 };
70 GType gst_element_get_type(void) {
71 static GType element_type = 0;
74 static const GTypeInfo element_info = {
75 sizeof(GstElementClass),
76 (GBaseInitFunc)gst_element_base_class_init,
78 (GClassInitFunc)gst_element_class_init,
83 (GInstanceInitFunc)gst_element_init,
85 element_type = g_type_register_static(GST_TYPE_OBJECT, "GstElement", &element_info, G_TYPE_FLAG_ABSTRACT);
91 gst_element_class_init (GstElementClass *klass)
93 GObjectClass *gobject_class;
94 GstObjectClass *gstobject_class;
96 gobject_class = (GObjectClass*) klass;
97 gstobject_class = (GstObjectClass*) klass;
99 parent_class = g_type_class_ref(GST_TYPE_OBJECT);
101 gst_element_signals[STATE_CHANGE] =
102 g_signal_newc ("state_change", G_TYPE_FROM_CLASS(klass), G_SIGNAL_RUN_LAST,
103 G_STRUCT_OFFSET (GstElementClass, state_change), NULL, NULL,
104 g_cclosure_marshal_VOID__INT, G_TYPE_NONE, 1,
106 gst_element_signals[NEW_PAD] =
107 g_signal_newc ("new_pad", G_TYPE_FROM_CLASS(klass), G_SIGNAL_RUN_LAST,
108 G_STRUCT_OFFSET (GstElementClass, new_pad), NULL, NULL,
109 g_cclosure_marshal_VOID__POINTER, G_TYPE_NONE, 1,
111 gst_element_signals[PAD_REMOVED] =
112 g_signal_newc ("pad_removed", G_TYPE_FROM_CLASS(klass), G_SIGNAL_RUN_LAST,
113 G_STRUCT_OFFSET (GstElementClass, pad_removed), NULL, NULL,
114 g_cclosure_marshal_VOID__POINTER, G_TYPE_NONE, 1,
116 gst_element_signals[NEW_GHOST_PAD] =
117 g_signal_newc ("new_ghost_pad", G_TYPE_FROM_CLASS(klass), G_SIGNAL_RUN_LAST,
118 G_STRUCT_OFFSET (GstElementClass, new_ghost_pad), NULL, NULL,
119 g_cclosure_marshal_VOID__POINTER, G_TYPE_NONE, 1,
121 gst_element_signals[GHOST_PAD_REMOVED] =
122 g_signal_newc ("ghost_pad_removed", G_TYPE_FROM_CLASS(klass), G_SIGNAL_RUN_LAST,
123 G_STRUCT_OFFSET (GstElementClass, ghost_pad_removed), NULL, NULL,
124 g_cclosure_marshal_VOID__POINTER, G_TYPE_NONE, 1,
126 gst_element_signals[ERROR] =
127 g_signal_newc ("error", G_TYPE_FROM_CLASS(klass), G_SIGNAL_RUN_LAST,
128 G_STRUCT_OFFSET (GstElementClass, error), NULL, NULL,
129 g_cclosure_marshal_VOID__STRING, G_TYPE_NONE,1,
131 gst_element_signals[EOS] =
132 g_signal_newc ("eos", G_TYPE_FROM_CLASS(klass), G_SIGNAL_RUN_LAST,
133 G_STRUCT_OFFSET (GstElementClass,eos), NULL, NULL,
134 g_cclosure_marshal_VOID__VOID, G_TYPE_NONE, 0);
138 gobject_class->set_property = GST_DEBUG_FUNCPTR(gst_element_set_property);
139 gobject_class->get_property = GST_DEBUG_FUNCPTR(gst_element_get_property);
140 gobject_class->shutdown = GST_DEBUG_FUNCPTR(gst_element_shutdown);
142 // gobject_class->destroy = GST_DEBUG_FUNCPTR(gst_element_real_destroy);
144 #ifndef GST_DISABLE_LOADSAVE
145 gstobject_class->save_thyself = GST_DEBUG_FUNCPTR(gst_element_save_thyself);
146 gstobject_class->restore_thyself = GST_DEBUG_FUNCPTR(gst_element_restore_thyself);
149 klass->change_state = GST_DEBUG_FUNCPTR(gst_element_change_state);
150 klass->elementfactory = NULL;
151 klass->padtemplates = NULL;
152 klass->numpadtemplates = 0;
156 gst_element_base_class_init (GstElementClass *klass)
158 GObjectClass *gobject_class;
160 gobject_class = (GObjectClass*) klass;
162 gobject_class->set_property = GST_DEBUG_FUNCPTR(gst_element_set_property);
163 gobject_class->get_property = GST_DEBUG_FUNCPTR(gst_element_get_property);
167 gst_element_init (GstElement *element)
169 element->current_state = GST_STATE_NULL;
170 element->pending_state = -1;
171 element->numpads = 0;
172 element->numsrcpads = 0;
173 element->numsinkpads = 0;
174 element->pads = NULL;
175 element->loopfunc = NULL;
176 element->threadstate = NULL;
177 element->sched = NULL;
182 gst_element_set_property (GObject *object, guint prop_id, const GValue *value, GParamSpec *pspec)
184 GstElementClass *oclass = (GstElementClass *)G_OBJECT_GET_CLASS(object);
186 GST_SCHEDULE_LOCK_ELEMENT ( GST_ELEMENT_SCHED(object), GST_ELEMENT(object) );
188 if (oclass->set_property)
189 (oclass->set_property)(object,prop_id,value,pspec);
191 GST_SCHEDULE_UNLOCK_ELEMENT ( GST_ELEMENT_SCHED(object), GST_ELEMENT(object) );
196 gst_element_get_property (GObject *object, guint prop_id, GValue *value, GParamSpec *pspec)
198 GstElementClass *oclass = (GstElementClass *)G_OBJECT_GET_CLASS(object);
200 GST_SCHEDULE_LOCK_ELEMENT (GST_ELEMENT_SCHED(object), GST_ELEMENT(object) );
202 if (oclass->get_property)
203 (oclass->get_property)(object,prop_id,value,pspec);
205 GST_SCHEDULE_UNLOCK_ELEMENT (GST_ELEMENT_SCHED(object), GST_ELEMENT(object) );
212 * Create a new element. Should never be used, as it does no good.
214 * Returns: new element
217 gst_element_new(void)
219 return GST_ELEMENT (g_object_new(GST_TYPE_ELEMENT,NULL));
223 * gst_element_set_name:
224 * @element: GstElement to set name of
225 * @name: new name of element
227 * Set the name of the element, getting rid of the old name if there was
231 gst_element_set_name (GstElement *element, const gchar *name)
233 g_return_if_fail (element != NULL);
234 g_return_if_fail (GST_IS_ELEMENT (element));
235 g_return_if_fail (name != NULL);
237 gst_object_set_name (GST_OBJECT (element), name);
241 * gst_element_get_name:
242 * @element: GstElement to get name of
244 * Get the name of the element.
246 * Returns: name of the element
249 gst_element_get_name (GstElement *element)
251 g_return_val_if_fail (element != NULL, NULL);
252 g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);
254 return GST_OBJECT_NAME (element);
258 * gst_element_set_parent:
259 * @element: GstElement to set parent of
260 * @parent: new parent of the object
262 * Set the parent of the element.
265 gst_element_set_parent (GstElement *element, GstObject *parent)
267 g_return_if_fail (element != NULL);
268 g_return_if_fail (GST_IS_ELEMENT (element));
269 g_return_if_fail (GST_OBJECT_PARENT (element) == NULL);
270 g_return_if_fail (parent != NULL);
271 g_return_if_fail (GST_IS_OBJECT (parent));
272 g_return_if_fail ((gpointer)element != (gpointer)parent);
274 gst_object_set_parent (GST_OBJECT (element), parent);
278 * gst_element_get_parent:
279 * @element: GstElement to get the parent of
281 * Get the parent of the element.
283 * Returns: parent of the element
286 gst_element_get_parent (GstElement *element)
288 g_return_val_if_fail (element != NULL, NULL);
289 g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);
291 return GST_OBJECT_PARENT (element);
295 * gst_element_add_pad:
296 * @element: element to add pad to
299 * Add a pad (connection point) to the element, setting the parent of the
300 * pad to the element (and thus adding a reference).
303 gst_element_add_pad (GstElement *element, GstPad *pad)
305 g_return_if_fail (element != NULL);
306 g_return_if_fail (GST_IS_ELEMENT (element));
307 g_return_if_fail (pad != NULL);
308 g_return_if_fail (GST_IS_PAD (pad));
310 // first check to make sure the pad's parent is already set
311 g_return_if_fail (GST_PAD_PARENT (pad) == NULL);
313 // then check to see if there's already a pad by that name here
314 g_return_if_fail (gst_object_check_uniqueness (element->pads, GST_PAD_NAME(pad)) == TRUE);
316 /* set the pad's parent */
317 GST_DEBUG (GST_CAT_ELEMENT_PADS,"setting parent of pad '%s' to '%s'\n",
318 GST_PAD_NAME (pad), GST_ELEMENT_NAME (element));
319 gst_object_set_parent (GST_OBJECT (pad), GST_OBJECT (element));
321 /* add it to the list */
322 element->pads = g_list_append (element->pads, pad);
324 if (gst_pad_get_direction (pad) == GST_PAD_SRC)
325 element->numsrcpads++;
327 element->numsinkpads++;
329 /* emit the NEW_PAD signal */
330 g_signal_emit (G_OBJECT (element), gst_element_signals[NEW_PAD], 0, pad);
334 * gst_element_remove_pad:
335 * @element: element to remove pad from
336 * @pad: pad to remove
338 * Remove a pad (connection point) from the element,
341 gst_element_remove_pad (GstElement *element, GstPad *pad)
343 g_return_if_fail (element != NULL);
344 g_return_if_fail (GST_IS_ELEMENT (element));
345 g_return_if_fail (pad != NULL);
346 g_return_if_fail (GST_IS_PAD (pad));
348 g_return_if_fail (GST_PAD_PARENT (pad) == element);
350 /* add it to the list */
351 element->pads = g_list_remove (element->pads, pad);
353 if (gst_pad_get_direction (pad) == GST_PAD_SRC)
354 element->numsrcpads--;
356 element->numsinkpads--;
358 g_signal_emit (G_OBJECT (element), gst_element_signals[PAD_REMOVED], 0, pad);
360 gst_object_unparent (GST_OBJECT (pad));
364 * gst_element_add_ghost_pad:
365 * @element: element to add ghost pad to
366 * @pad: pad from which the new ghost pad will be created
367 * @name: name of the new ghost pad
369 * Create a ghost pad from the given pad, and add it to the list of pads
373 gst_element_add_ghost_pad (GstElement *element, GstPad *pad, gchar *name)
377 g_return_if_fail (element != NULL);
378 g_return_if_fail (GST_IS_ELEMENT (element));
379 g_return_if_fail (pad != NULL);
380 g_return_if_fail (GST_IS_PAD (pad));
382 // then check to see if there's already a pad by that name here
383 g_return_if_fail (gst_object_check_uniqueness (element->pads, name) == TRUE);
385 GST_DEBUG(GST_CAT_ELEMENT_PADS,"creating new ghost pad called %s, from pad %s:%s\n",
386 name,GST_DEBUG_PAD_NAME(pad));
387 ghostpad = gst_ghost_pad_new (name, pad);
389 /* add it to the list */
390 GST_DEBUG(GST_CAT_ELEMENT_PADS,"adding ghost pad %s to element %s\n",
391 name, GST_ELEMENT_NAME (element));
392 element->pads = g_list_append (element->pads, ghostpad);
394 // set the parent of the ghostpad
395 gst_object_set_parent (GST_OBJECT (ghostpad), GST_OBJECT (element));
397 GST_DEBUG(GST_CAT_ELEMENT_PADS,"added ghostpad %s:%s\n",GST_DEBUG_PAD_NAME(ghostpad));
399 /* emit the NEW_GHOST_PAD signal */
400 g_signal_emit (G_OBJECT (element), gst_element_signals[NEW_GHOST_PAD], 0, ghostpad);
404 * gst_element_remove_ghost_pad:
405 * @element: element to remove the ghost pad from
406 * @pad: ghost pad to remove
408 * removes a ghost pad from an element
412 gst_element_remove_ghost_pad (GstElement *element, GstPad *pad)
414 g_return_if_fail (element != NULL);
415 g_return_if_fail (GST_IS_ELEMENT (element));
416 g_return_if_fail (pad != NULL);
417 g_return_if_fail (GST_IS_GHOST_PAD (pad));
419 // FIXME this is redundant?
420 // wingo 10-july-2001: I don't think so, you have to actually remove the pad
421 // from the element. gst_pad_remove_ghost_pad just removes the ghostpad from
422 // the real pad's ghost pad list
423 gst_pad_remove_ghost_pad (GST_PAD (GST_PAD_REALIZE (pad)), pad);
424 gst_element_remove_pad (element, pad);
429 * gst_element_get_pad:
430 * @element: element to find pad of
431 * @name: name of pad to retrieve
433 * Retrieve a pad from the element by name.
435 * Returns: requested pad if found, otherwise NULL.
438 gst_element_get_pad (GstElement *element, const gchar *name)
442 g_return_val_if_fail (element != NULL, NULL);
443 g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);
444 g_return_val_if_fail (name != NULL, NULL);
446 // if there aren't any pads, well, we're not likely to find one
447 if (!element->numpads)
450 // look through the list, matching by name
451 walk = element->pads;
453 GstPad *pad = GST_PAD(walk->data);
454 if (!strcmp (GST_PAD_NAME(pad), name)) {
455 GST_INFO(GST_CAT_ELEMENT_PADS,"found pad %s:%s",GST_DEBUG_PAD_NAME(pad));
458 walk = g_list_next (walk);
461 GST_INFO(GST_CAT_ELEMENT_PADS,"no such pad '%s' in element \"%s\"",name,GST_ELEMENT_NAME(element));
466 * gst_element_get_pad_list:
467 * @element: element to get pads of
469 * Retrieve a list of the pads associated with the element.
471 * Returns: GList of pads
474 gst_element_get_pad_list (GstElement *element)
476 g_return_val_if_fail (element != NULL, NULL);
477 g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);
479 /* return the list of pads */
480 return element->pads;
484 * gst_element_class_add_padtemplate:
485 * @klass: element class to add padtemplate to
486 * @templ: padtemplate to add
488 * Add a padtemplate to an element class. This is useful if you have derived a custom
489 * bin and wish to provide an on-request pad at runtime. Plugin writers should use
490 * gst_elementfactory_add_padtemplate instead.
493 gst_element_class_add_padtemplate (GstElementClass *klass, GstPadTemplate *templ)
495 g_return_if_fail (klass != NULL);
496 g_return_if_fail (GST_IS_ELEMENT_CLASS (klass));
497 g_return_if_fail (templ != NULL);
498 g_return_if_fail (GST_IS_PADTEMPLATE (templ));
500 klass->padtemplates = g_list_append (klass->padtemplates, templ);
501 klass->numpadtemplates++;
505 * gst_element_get_padtemplate_list:
506 * @element: element to get padtemplates of
508 * Retrieve a list of the padtemplates associated with the element.
510 * Returns: GList of padtemplates
513 gst_element_get_padtemplate_list (GstElement *element)
515 GstElementClass *oclass;
517 g_return_val_if_fail (element != NULL, NULL);
518 g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);
520 oclass = GST_ELEMENT_CLASS (G_OBJECT_GET_CLASS(element));
522 return oclass->padtemplates;
526 * gst_element_get_padtemplate_by_name:
527 * @element: element to get padtemplate of
528 * @name: the name of the padtemplate to get.
530 * Retrieve a padtemplate from this element with the
533 * Returns: the padtemplate with the given name
536 gst_element_get_padtemplate_by_name (GstElement *element, const guchar *name)
540 g_return_val_if_fail (element != NULL, NULL);
541 g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);
542 g_return_val_if_fail (name != NULL, NULL);
544 padlist = gst_element_get_padtemplate_list (element);
547 GstPadTemplate *padtempl = (GstPadTemplate*) padlist->data;
549 if (!strcmp (padtempl->name_template, name))
552 padlist = g_list_next (padlist);
559 * gst_element_get_padtemplate_by_compatible:
560 * @element: element to get padtemplate of
561 * @templ: a template to find a compatible template for
563 * Generate a padtemplate for this element compatible with the given
564 * template, ie able to link to it.
566 * Returns: the padtemplate
568 static GstPadTemplate*
569 gst_element_get_padtemplate_by_compatible (GstElement *element, GstPadTemplate *compattempl)
571 GstPadTemplate *newtempl = NULL;
574 GST_DEBUG(GST_CAT_ELEMENT_PADS,"gst_element_get_padtemplate_by_compatible()\n");
576 g_return_val_if_fail (element != NULL, NULL);
577 g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);
578 g_return_val_if_fail (compattempl != NULL, NULL);
580 padlist = gst_element_get_padtemplate_list (element);
583 GstPadTemplate *padtempl = (GstPadTemplate*) padlist->data;
584 gboolean compat = FALSE;
588 // Check direction (must be opposite)
591 GST_DEBUG(GST_CAT_CAPS,"checking direction and caps\n");
592 if (padtempl->direction == GST_PAD_SRC &&
593 compattempl->direction == GST_PAD_SINK) {
594 GST_DEBUG(GST_CAT_CAPS,"compatible direction: found src pad template\n");
595 compat = gst_caps_check_compatibility(GST_PADTEMPLATE_CAPS (padtempl),
596 GST_PADTEMPLATE_CAPS (compattempl));
597 GST_DEBUG(GST_CAT_CAPS,"caps are %scompatible\n", (compat?"":"not "));
598 } else if (padtempl->direction == GST_PAD_SINK &&
599 compattempl->direction == GST_PAD_SRC) {
600 GST_DEBUG(GST_CAT_CAPS,"compatible direction: found sink pad template\n");
601 compat = gst_caps_check_compatibility(GST_PADTEMPLATE_CAPS (compattempl),
602 GST_PADTEMPLATE_CAPS (padtempl));
603 GST_DEBUG(GST_CAT_CAPS,"caps are %scompatible\n", (compat?"":"not "));
611 padlist = g_list_next (padlist);
618 gst_element_request_pad (GstElement *element, GstPadTemplate *templ)
620 GstPad *newpad = NULL;
621 GstElementClass *oclass;
623 oclass = GST_ELEMENT_CLASS (G_OBJECT_GET_CLASS(element));
624 if (oclass->request_new_pad)
625 newpad = (oclass->request_new_pad)(element, templ);
631 * gst_element_request_compatible_pad:
632 * @element: element to request a new pad from
633 * @templ: a pad template to which the new pad should be able to connect
635 * Request a new pad from the element. The template will
636 * be used to decide what type of pad to create. This function
637 * is typically used for elements with a padtemplate with presence
640 * Returns: the new pad that was created.
643 gst_element_request_compatible_pad (GstElement *element, GstPadTemplate *templ)
645 GstPadTemplate *templ_new;
648 g_return_val_if_fail (element != NULL, NULL);
649 g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);
650 g_return_val_if_fail (templ != NULL, NULL);
652 templ_new = gst_element_get_padtemplate_by_compatible (element, templ);
653 if (templ_new != NULL)
654 pad = gst_element_request_pad (element, templ_new);
660 * gst_element_request_pad_by_name:
661 * @element: element to request a new pad from
662 * @name: the name of the padtemplate to use.
664 * Request a new pad from the element. The name argument will
665 * be used to decide what padtemplate to use. This function
666 * is typically used for elements with a padtemplate with presence
669 * Returns: the new pad that was created.
672 gst_element_request_pad_by_name (GstElement *element, const gchar *name)
674 GstPadTemplate *templ;
677 g_return_val_if_fail (element != NULL, NULL);
678 g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);
679 g_return_val_if_fail (name != NULL, NULL);
681 templ = gst_element_get_padtemplate_by_name (element, name);
685 pad = gst_element_request_pad (element, templ);
691 * gst_element_connect:
692 * @src: element containing source pad
693 * @srcpadname: name of pad in source element
694 * @dest: element containing destination pad
695 * @destpadname: name of pad in destination element
697 * Connect the two named pads of the source and destination elements.
698 * Side effect is that if one of the pads has no parent, it becomes a
699 * child of the parent of the other element. If they have different
700 * parents, the connection fails.
703 gst_element_connect (GstElement *src, const gchar *srcpadname,
704 GstElement *dest, const gchar *destpadname)
706 GstPad *srcpad,*destpad;
708 g_return_if_fail (src != NULL);
709 g_return_if_fail (GST_IS_ELEMENT(src));
710 g_return_if_fail (srcpadname != NULL);
711 g_return_if_fail (dest != NULL);
712 g_return_if_fail (GST_IS_ELEMENT(dest));
713 g_return_if_fail (destpadname != NULL);
715 /* obtain the pads requested */
716 srcpad = gst_element_get_pad (src, srcpadname);
717 if (srcpad == NULL) {
718 GST_ERROR(src,"source element has no pad \"%s\"",srcpadname);
721 destpad = gst_element_get_pad (dest, destpadname);
722 if (srcpad == NULL) {
723 GST_ERROR(dest,"destination element has no pad \"%s\"",destpadname);
727 /* we're satisified they can be connected, let's do it */
728 gst_pad_connect(srcpad,destpad);
732 * gst_element_disconnect:
733 * @src: element containing source pad
734 * @srcpadname: name of pad in source element
735 * @dest: element containing destination pad
736 * @destpadname: name of pad in destination element
738 * Disconnect the two named pads of the source and destination elements.
741 gst_element_disconnect (GstElement *src, const gchar *srcpadname,
742 GstElement *dest, const gchar *destpadname)
744 GstPad *srcpad,*destpad;
746 g_return_if_fail (src != NULL);
747 g_return_if_fail (GST_IS_ELEMENT(src));
748 g_return_if_fail (srcpadname != NULL);
749 g_return_if_fail (dest != NULL);
750 g_return_if_fail (GST_IS_ELEMENT(dest));
751 g_return_if_fail (destpadname != NULL);
753 /* obtain the pads requested */
754 srcpad = gst_element_get_pad (src, srcpadname);
755 if (srcpad == NULL) {
756 GST_ERROR(src,"source element has no pad \"%s\"",srcpadname);
759 destpad = gst_element_get_pad (dest, destpadname);
760 if (srcpad == NULL) {
761 GST_ERROR(dest,"destination element has no pad \"%s\"",destpadname);
765 /* we're satisified they can be disconnected, let's do it */
766 gst_pad_disconnect(srcpad,destpad);
771 * @element: Element with the error
772 * @error: String describing the error
774 * This function is used internally by elements to signal an error
775 * condition. It results in the "error" signal.
778 gst_element_error (GstElement *element, const gchar *error)
780 g_error("GstElement: error in element '%s': %s\n", GST_ELEMENT_NAME(element), error);
782 /* FIXME: this is not finished!!! */
784 g_signal_emit (G_OBJECT (element), gst_element_signals[ERROR], 0, error);
789 * gst_element_set_state:
790 * @element: element to change state of
791 * @state: new element state
793 * Sets the state of the element. This function will only set
794 * the elements pending state.
796 * Returns: whether or not the state was successfully set.
799 gst_element_set_state (GstElement *element, GstElementState state)
801 GstElementClass *oclass;
802 GstElementState curpending;
803 GstElementStateReturn return_val = GST_STATE_SUCCESS;
805 // g_print("gst_element_set_state(\"%s\",%08lx)\n",
806 // element->name,state);
808 g_return_val_if_fail (element != NULL, GST_STATE_FAILURE);
809 g_return_val_if_fail (GST_IS_ELEMENT (element), GST_STATE_FAILURE);
810 g_return_val_if_fail (element->sched != NULL, GST_STATE_FAILURE);
812 GST_DEBUG_ELEMENT (GST_CAT_STATES,element, "setting state from %s to %s\n",
813 gst_element_statename(GST_STATE(element)),
814 gst_element_statename(state));
816 /* start with the current state */
817 curpending = GST_STATE(element);
819 /* loop until the final requested state is set */
820 while (GST_STATE(element) != state) {
821 /* move the curpending state in the correct direction */
822 if (curpending < state) curpending<<=1;
825 /* set the pending state variable */
826 // FIXME: should probably check to see that we don't already have one
827 GST_STATE_PENDING (element) = curpending;
828 if (curpending != state)
829 GST_DEBUG_ELEMENT (GST_CAT_STATES,element,"intermediate: setting state to %s\n",
830 gst_element_statename(curpending));
832 /* call the state change function so it can set the state */
833 oclass = GST_ELEMENT_CLASS (G_OBJECT_GET_CLASS(element));
834 if (oclass->change_state)
835 return_val = (oclass->change_state)(element);
837 /* if that outright didn't work, we need to bail right away */
838 /* NOTE: this will bail on ASYNC as well! */
839 if (return_val == GST_STATE_FAILURE) {
840 GST_DEBUG_ELEMENT (GST_CAT_STATES,element,"have failed change_state return\n");
844 /* Last thing we do is verify that a successful state change really
845 * did change the state... */
846 if (GST_STATE(element) != curpending) {
847 GST_DEBUG_ELEMENT (GST_CAT_STATES, element, "element claimed state-change success, but state didn't change\n");
848 return GST_STATE_FAILURE;
852 /* this is redundant, really, it will always return SUCCESS */
857 * gst_element_get_factory:
858 * @element: element to request the factory
860 * Retrieves the factory that was used to create this element
862 * Returns: the factory used for creating this element
865 gst_element_get_factory (GstElement *element)
867 GstElementClass *oclass;
869 g_return_val_if_fail (element != NULL, NULL);
870 g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);
872 oclass = GST_ELEMENT_CLASS (G_OBJECT_GET_CLASS(element));
874 return oclass->elementfactory;
879 * gst_element_change_state:
880 * @element: element to change state of
882 * Changes the state of the element, but more importantly fires off a signal
883 * indicating the new state.
884 * The element will have no pending states anymore.
886 * Returns: whether or not the state change was successfully set.
888 GstElementStateReturn
889 gst_element_change_state (GstElement *element)
891 g_return_val_if_fail (element != NULL, GST_STATE_FAILURE);
892 g_return_val_if_fail (GST_IS_ELEMENT (element), GST_STATE_FAILURE);
894 // GST_DEBUG_ELEMENT (GST_CAT_STATES, element, "default handler sets state to %s\n",
895 // gst_element_statename(GST_STATE_PENDING(element)));
897 if (GST_STATE_TRANSITION(element) == GST_STATE_PAUSED_TO_PLAYING) {
898 g_return_val_if_fail(GST_ELEMENT_SCHED(element), GST_STATE_FAILURE);
899 if (GST_ELEMENT_PARENT(element))
900 GST_DEBUG(GST_CAT_STATES,"PAUSED->PLAYING: element \"%s\" has parent \"%s\" and sched %p\n",
901 GST_ELEMENT_NAME(element),GST_ELEMENT_NAME(GST_ELEMENT_PARENT(element)),GST_ELEMENT_SCHED(element));
902 GST_SCHEDULE_ENABLE_ELEMENT (element->sched,element);
904 else if (GST_STATE_TRANSITION(element) == GST_STATE_PLAYING_TO_PAUSED) {
905 if (GST_ELEMENT_PARENT(element))
906 GST_DEBUG(GST_CAT_STATES,"PLAYING->PAUSED: element \"%s\" has parent \"%s\" and sched %p\n",
907 GST_ELEMENT_NAME(element),GST_ELEMENT_NAME(GST_ELEMENT_PARENT(element)),GST_ELEMENT_SCHED(element));
908 GST_SCHEDULE_DISABLE_ELEMENT (element->sched,element);
911 GST_STATE (element) = GST_STATE_PENDING (element);
912 GST_STATE_PENDING (element) = GST_STATE_VOID_PENDING;
914 // note: queues' state_change is a special case because it needs to lock
915 // for synchronization (from another thread). since this signal may block
916 // or (worse) make another state change, the queue needs to unlock before
917 // calling. thus, gstqueue.c::gst_queue_state_change() blocks, unblocks,
918 // unlocks, then emits this.
919 g_signal_emit (G_OBJECT (element), gst_element_signals[STATE_CHANGE], 0,
920 GST_STATE (element));
921 return GST_STATE_SUCCESS;
925 gst_element_shutdown (GObject *object)
927 GstElement *element = GST_ELEMENT (object);
929 GST_DEBUG_ELEMENT (GST_CAT_REFCOUNTING, element, "shutdown\n");
931 if (GST_IS_BIN (GST_OBJECT_PARENT (element)))
932 gst_bin_remove (GST_BIN (GST_OBJECT_PARENT (element)), element);
934 if (G_OBJECT_CLASS (parent_class)->shutdown)
935 G_OBJECT_CLASS (parent_class)->shutdown (G_OBJECT (object));
939 gst_element_real_destroy (GObject *object)
941 GstElement *element = GST_ELEMENT (object);
945 GST_DEBUG_ELEMENT (GST_CAT_REFCOUNTING, element, "destroy\n");
949 orig = pads = g_list_copy (element->pads);
951 pad = GST_PAD (pads->data);
952 //gst_object_destroy (GST_OBJECT (pad));
953 gst_object_ref (GST_OBJECT (pad));
954 gst_element_remove_pad (element, pad);
955 gst_object_unref (GST_OBJECT (pad));
956 pads = g_list_next (pads);
959 g_list_free (element->pads);
960 element->pads = NULL;
963 element->numsrcpads = 0;
964 element->numsinkpads = 0;
967 // if (G_OBJECT_CLASS (parent_class)->destroy)
968 // G_OBJECT_CLASS (parent_class)->destroy (object);
972 static gchar *_gst_element_type_names[] = {
988 #ifndef GST_DISABLE_LOADSAVE
990 * gst_element_save_thyself:
991 * @element: GstElement to save
992 * @parent: the xml parent node
994 * Saves the element as part of the given XML structure
996 * Returns: the new xml node
999 gst_element_save_thyself (GstObject *object,
1003 GstElementClass *oclass;
1005 GstElement *element;
1007 g_return_val_if_fail (object != NULL, parent);
1008 g_return_val_if_fail (GST_IS_ELEMENT (object), parent);
1009 g_return_val_if_fail (parent != NULL, parent);
1011 element = GST_ELEMENT (object);
1013 oclass = GST_ELEMENT_CLASS (G_OBJECT_GET_CLASS(element));
1015 xmlNewChild(parent, NULL, "name", GST_ELEMENT_NAME(element));
1017 if (oclass->elementfactory != NULL) {
1018 GstElementFactory *factory = (GstElementFactory *)oclass->elementfactory;
1020 xmlNewChild (parent, NULL, "type", factory->name);
1021 xmlNewChild (parent, NULL, "version", factory->details->version);
1024 // if (element->manager)
1025 // xmlNewChild(parent, NULL, "manager", GST_ELEMENT_NAME(element->manager));
1027 /* FIXME FIXME FIXME!
1028 // output all args to the element
1029 type = G_OBJECT_TYPE (element);
1030 while (type != G_TYPE_INVALID) {
1035 args = gtk_object_query_args (type, &flags, &num_args);
1037 for (i=0; i<num_args; i++) {
1038 if ((args[i].type > G_TYPE_NONE) &&
1039 (flags[i] & GTK_ARG_READABLE)) {
1041 gtk_object_getv (G_OBJECT (element), 1, &args[i]);
1042 arg = xmlNewChild (parent, NULL, "arg", NULL);
1043 xmlNewChild (arg, NULL, "name", args[i].name);
1044 switch (args[i].type) {
1046 xmlNewChild (arg, NULL, "value",
1047 g_strdup_printf ("%c", G_VALUE_CHAR (args[i])));
1050 xmlNewChild (arg, NULL, "value",
1051 g_strdup_printf ("%d", G_VALUE_UCHAR (args[i])));
1054 xmlNewChild (arg, NULL, "value",
1055 G_VALUE_BOOL (args[i]) ? "true" : "false");
1058 xmlNewChild (arg, NULL, "value",
1059 g_strdup_printf ("%d", G_VALUE_INT (args[i])));
1062 xmlNewChild (arg, NULL, "value",
1063 g_strdup_printf ("%ld", G_VALUE_LONG (args[i])));
1066 xmlNewChild (arg, NULL, "value",
1067 g_strdup_printf ("%lu", G_VALUE_ULONG (args[i])));
1070 xmlNewChild (arg, NULL, "value",
1071 g_strdup_printf ("%f", G_VALUE_FLOAT (args[i])));
1074 xmlNewChild (arg, NULL, "value",
1075 g_strdup_printf ("%g", G_VALUE_DOUBLE (args[i])));
1078 xmlNewChild (arg, NULL, "value", G_VALUE_STRING (args[i]));
1081 if (args[i].type == GST_TYPE_FILENAME) {
1082 xmlNewChild (arg, NULL, "value", G_VALUE_STRING (args[i]));
1088 type = gtk_type_parent (type);
1092 pads = GST_ELEMENT_PADS (element);
1095 GstPad *pad = GST_PAD (pads->data);
1096 // figure out if it's a direct pad or a ghostpad
1097 if (GST_ELEMENT (GST_OBJECT_PARENT (pad)) == element) {
1098 xmlNodePtr padtag = xmlNewChild (parent, NULL, "pad", NULL);
1099 gst_object_save_thyself (GST_OBJECT (pad), padtag);
1101 pads = g_list_next (pads);
1108 * gst_element_restore_thyself:
1109 * @self: the xml node
1110 * @parent: the parent of this object when it's loaded
1112 * Load the element from the XML description
1114 * Returns: the new element
1117 gst_element_restore_thyself (xmlNodePtr self, GstObject *parent)
1119 xmlNodePtr children = self->xmlChildrenNode;
1120 GstElement *element;
1121 GstObjectClass *oclass;
1122 guchar *name = NULL;
1123 guchar *value = NULL;
1124 guchar *type = NULL;
1126 // first get the needed tags to construct the element
1128 if (!strcmp (children->name, "name")) {
1129 name = g_strdup (xmlNodeGetContent (children));
1130 } else if (!strcmp (children->name, "type")) {
1131 type = g_strdup (xmlNodeGetContent (children));
1133 children = children->next;
1135 g_return_val_if_fail (name != NULL, NULL);
1136 g_return_val_if_fail (type != NULL, NULL);
1138 GST_INFO (GST_CAT_XML,"loading \"%s\" of type \"%s\"", name, type);
1140 element = gst_elementfactory_make (type, name);
1142 g_return_val_if_fail (element != NULL, NULL);
1144 // ne need to set the parent on this object bacause the pads
1145 // will go through the hierarchy to connect to thier peers
1147 gst_object_set_parent (GST_OBJECT (element), parent);
1149 // we have the element now, set the arguments
1150 children = self->xmlChildrenNode;
1153 if (!strcmp (children->name, "arg")) {
1154 xmlNodePtr child = children->xmlChildrenNode;
1157 if (!strcmp (child->name, "name")) {
1158 name = g_strdup (xmlNodeGetContent (child));
1160 else if (!strcmp (child->name, "value")) {
1161 value = g_strdup (xmlNodeGetContent (child));
1163 child = child->next;
1165 gst_util_set_object_arg ((GObject *)G_OBJECT (element), name, value);
1167 children = children->next;
1169 // we have the element now, set the pads
1170 children = self->xmlChildrenNode;
1173 if (!strcmp (children->name, "pad")) {
1174 gst_pad_load_and_connect (children, GST_OBJECT (element));
1176 children = children->next;
1179 oclass = GST_OBJECT_CLASS (G_OBJECT_GET_CLASS(element));
1180 if (oclass->restore_thyself)
1181 (oclass->restore_thyself) (GST_OBJECT (element), self);
1184 gst_object_unparent (GST_OBJECT (element));
1186 gst_class_signal_emit_by_name (GST_OBJECT (element), "object_loaded", self);
1190 #endif // GST_DISABLE_LOADSAVE
1193 * gst_element_set_sched:
1194 * @element: Element to set manager of.
1195 * @sched: @GstSchedule to set.
1197 * Sets the scheduler of the element. For internal use only, unless you're
1198 * writing a new bin subclass.
1201 gst_element_set_sched (GstElement *element,
1204 GST_INFO_ELEMENT (GST_CAT_PARENTAGE, element, "setting scheduler to %p",sched);
1205 element->sched = sched;
1209 * gst_element_get_sched:
1210 * @element: Element to get manager of.
1212 * Returns the scheduler of the element.
1214 * Returns: Element's scheduler
1217 gst_element_get_sched (GstElement *element)
1219 return element->sched;
1223 * gst_element_set_loop_function:
1224 * @element: Element to set loop function of.
1225 * @loop: Pointer to loop function.
1227 * This sets the loop function for the element. The function pointed to
1228 * can deviate from the GstElementLoopFunction definition in type of
1231 * NOTE: in order for this to take effect, the current loop function *must*
1232 * exit. Assuming the loop function itself is the only one who will cause
1233 * a new loopfunc to be assigned, this should be no problem.
1236 gst_element_set_loop_function(GstElement *element,
1237 GstElementLoopFunction loop)
1239 /* set the loop function */
1240 element->loopfunc = loop;
1242 /* set the NEW_LOOPFUNC flag so everyone knows to go try again */
1243 GST_FLAG_SET(element,GST_ELEMENT_NEW_LOOPFUNC);
1247 * gst_element_signal_eos:
1248 * @element: element to trigger the eos signal of
1250 * Throws the eos signal to indicate that the end of the stream is reached.
1253 gst_element_signal_eos (GstElement *element)
1255 g_return_if_fail (element != NULL);
1256 g_return_if_fail (GST_IS_ELEMENT (element));
1258 GST_DEBUG(GST_CAT_EVENT, "signaling EOS on element %s\n",GST_OBJECT_NAME(element));
1259 g_signal_emit (G_OBJECT (element), gst_element_signals[EOS], 0);
1260 GST_FLAG_SET(element,GST_ELEMENT_COTHREAD_STOPPING);
1264 const gchar *gst_element_statename(int state) {
1266 #ifdef GST_DEBUG_COLOR
1267 case GST_STATE_VOID_PENDING: return "NONE_PENDING";break;
1268 case GST_STATE_NULL: return "\033[01;37mNULL\033[00m";break;
1269 case GST_STATE_READY: return "\033[01;31mREADY\033[00m";break;
1270 case GST_STATE_PLAYING: return "\033[01;32mPLAYING\033[00m";break;
1271 case GST_STATE_PAUSED: return "\033[01;33mPAUSED\033[00m";break;
1272 default: return "\033[01;37;41mUNKNOWN!\033[00m";
1274 case GST_STATE_VOID_PENDING: return "NONE_PENDING";break;
1275 case GST_STATE_NULL: return "NULL";break;
1276 case GST_STATE_READY: return "READY";break;
1277 case GST_STATE_PLAYING: return "PLAYING";break;
1278 case GST_STATE_PAUSED: return "PAUSED";break;
1279 default: return "UNKNOWN!";