2 * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
3 * 2000 Wim Taymans <wtay@chello.be>
5 * gstpad.c: Pads for linking elements together
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.
24 * @short_description: Object contained by elements that allows links to
26 * @see_also: #GstPadTemplate, #GstElement, #GstEvent
28 * A #GstElement is linked to other elements via "pads", which are extremely
29 * light-weight generic link points.
30 * After two pads are retrieved from an element with gst_element_get_pad(),
31 * the pads can be link with gst_pad_link(). (For quick links,
32 * you can also use gst_element_link(), which will make the obvious
33 * link for you if it's straightforward.)
35 * Pads are typically created from a #GstPadTemplate with
36 * gst_pad_new_from_template().
38 * Pads have #GstCaps attached to it to describe the media type they are
39 * capable of dealing with. gst_pad_get_caps() and gst_pad_set_caps() are
40 * used to manipulate the caps of the pads.
41 * Pads created from a pad template cannot set capabilities that are
42 * incompatible with the pad template capabilities.
44 * Pads without pad templates can be created with gst_pad_new(),
45 * which takes a direction and a name as an argument. If the name is NULL,
46 * then a guaranteed unique name will be assigned to it.
48 * gst_pad_get_parent() will retrieve the #GstElement that owns the pad.
50 * A #GstElement creating a pad will typically use the various
51 * gst_pad_set_*_function() calls to register callbacks for various events
54 * GstElements will use gst_pad_push() and gst_pad_pull_range() to push out
55 * or pull in a buffer.
57 * To send a #GstEvent on a pad, use gst_pad_send_event().
59 * Last reviewed on 2005-11-23 (0.9.5)
63 #include "gst_private.h"
66 #include "gstghostpad.h"
67 #include "gstpadtemplate.h"
68 #include "gstenumtypes.h"
69 #include "gstmarshal.h"
74 #include "glib-compat-private.h"
76 GST_DEBUG_CATEGORY_STATIC (debug_dataflow);
77 #define GST_CAT_DEFAULT GST_CAT_PADS
79 /* Pad signals and args */
99 static void gst_pad_class_init (GstPadClass * klass);
100 static void gst_pad_init (GstPad * pad);
101 static void gst_pad_dispose (GObject * object);
102 static void gst_pad_finalize (GObject * object);
103 static void gst_pad_set_property (GObject * object, guint prop_id,
104 const GValue * value, GParamSpec * pspec);
105 static void gst_pad_get_property (GObject * object, guint prop_id,
106 GValue * value, GParamSpec * pspec);
108 static GstFlowReturn handle_pad_block (GstPad * pad);
109 static GstCaps *gst_pad_get_caps_unlocked (GstPad * pad);
110 static void gst_pad_set_pad_template (GstPad * pad, GstPadTemplate * templ);
111 static gboolean gst_pad_activate_default (GstPad * pad);
112 static gboolean gst_pad_acceptcaps_default (GstPad * pad, GstCaps * caps);
114 #ifndef GST_DISABLE_LOADSAVE
115 static xmlNodePtr gst_pad_save_thyself (GstObject * object, xmlNodePtr parent);
118 static GstObjectClass *parent_class = NULL;
119 static guint gst_pad_signals[LAST_SIGNAL] = { 0 };
121 /* quarks for probe signals */
122 static GQuark buffer_quark;
123 static GQuark event_quark;
132 static GstFlowQuarks flow_quarks[] = {
133 {GST_FLOW_RESEND, "resend", 0},
134 {GST_FLOW_OK, "ok", 0},
135 {GST_FLOW_NOT_LINKED, "not-linked", 0},
136 {GST_FLOW_WRONG_STATE, "wrong-state", 0},
137 {GST_FLOW_UNEXPECTED, "unexpected", 0},
138 {GST_FLOW_NOT_NEGOTIATED, "not-negotiated", 0},
139 {GST_FLOW_ERROR, "error", 0},
140 {GST_FLOW_NOT_SUPPORTED, "not-supported", 0},
147 * @ret: a #GstFlowReturn to get the name of.
149 * Gets a string representing the given flow return.
151 * Returns: a string with the name of the flow return.
153 G_CONST_RETURN gchar *
154 gst_flow_get_name (GstFlowReturn ret)
158 for (i = 0; flow_quarks[i].name; i++) {
159 if (ret == flow_quarks[i].ret)
160 return flow_quarks[i].name;
167 * @ret: a #GstFlowReturn to get the quark of.
169 * Get the unique quark for the given GstFlowReturn.
171 * Returns: the quark associated with the flow return or 0 if an
172 * invalid return was specified.
175 gst_flow_to_quark (GstFlowReturn ret)
179 for (i = 0; flow_quarks[i].name; i++) {
180 if (ret == flow_quarks[i].ret)
181 return flow_quarks[i].quark;
187 gst_pad_get_type (void)
189 static GType gst_pad_type = 0;
191 if (G_UNLIKELY (gst_pad_type == 0)) {
192 static const GTypeInfo pad_info = {
193 sizeof (GstPadClass), NULL, NULL,
194 (GClassInitFunc) gst_pad_class_init, NULL, NULL,
197 (GInstanceInitFunc) gst_pad_init, NULL
201 gst_pad_type = g_type_register_static (GST_TYPE_OBJECT, "GstPad",
204 buffer_quark = g_quark_from_static_string ("buffer");
205 event_quark = g_quark_from_static_string ("event");
207 for (i = 0; flow_quarks[i].name; i++) {
208 flow_quarks[i].quark = g_quark_from_static_string (flow_quarks[i].name);
211 GST_DEBUG_CATEGORY_INIT (debug_dataflow, "GST_DATAFLOW",
212 GST_DEBUG_BOLD | GST_DEBUG_FG_GREEN, "dataflow inside pads");
218 _gst_do_pass_data_accumulator (GSignalInvocationHint * ihint,
219 GValue * return_accu, const GValue * handler_return, gpointer dummy)
221 gboolean ret = g_value_get_boolean (handler_return);
223 GST_DEBUG ("accumulated %d", ret);
224 g_value_set_boolean (return_accu, ret);
230 default_have_data (GstPad * pad, GstMiniObject * o)
236 gst_pad_class_init (GstPadClass * klass)
238 GObjectClass *gobject_class;
241 GstObjectClass *gstobject_class;
243 gobject_class = (GObjectClass *) klass;
244 gstobject_class = (GstObjectClass *) klass;
246 parent_class = g_type_class_ref (GST_TYPE_OBJECT);
248 gobject_class->dispose = GST_DEBUG_FUNCPTR (gst_pad_dispose);
249 gobject_class->finalize = GST_DEBUG_FUNCPTR (gst_pad_finalize);
250 gobject_class->set_property = GST_DEBUG_FUNCPTR (gst_pad_set_property);
251 gobject_class->get_property = GST_DEBUG_FUNCPTR (gst_pad_get_property);
255 * @pad: the pad that emitted the signal
256 * @peer: the peer pad that has been connected
258 * Signals that a pad has been linked to the peer pad.
260 gst_pad_signals[PAD_LINKED] =
261 g_signal_new ("linked", G_TYPE_FROM_CLASS (klass), G_SIGNAL_RUN_LAST,
262 G_STRUCT_OFFSET (GstPadClass, linked), NULL, NULL,
263 gst_marshal_VOID__OBJECT, G_TYPE_NONE, 1, GST_TYPE_PAD);
266 * @pad: the pad that emitted the signal
267 * @peer: the peer pad that has been disconnected
269 * Signals that a pad has been unlinked from the peer pad.
271 gst_pad_signals[PAD_UNLINKED] =
272 g_signal_new ("unlinked", G_TYPE_FROM_CLASS (klass), G_SIGNAL_RUN_LAST,
273 G_STRUCT_OFFSET (GstPadClass, unlinked), NULL, NULL,
274 gst_marshal_VOID__OBJECT, G_TYPE_NONE, 1, GST_TYPE_PAD);
276 * GstPad::request-link:
277 * @pad: the pad that emitted the signal
278 * @peer: the peer pad for which a connection is requested
280 * Signals that a pad connection has been requested.
282 gst_pad_signals[PAD_REQUEST_LINK] =
283 g_signal_new ("request-link", G_TYPE_FROM_CLASS (klass),
284 G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GstPadClass, request_link), NULL,
285 NULL, gst_marshal_VOID__OBJECT, G_TYPE_NONE, 0);
289 * @pad: the pad that emitted the signal
290 * @mini_obj: new data
292 * Signals that new data is available on the pad. This signal is used
293 * internally for implementing pad probes.
294 * See gst_pad_add_*_probe functions.
296 * Returns: %TRUE to keep the data, %FALSE to drop it
298 gst_pad_signals[PAD_HAVE_DATA] =
299 g_signal_new ("have-data", G_TYPE_FROM_CLASS (klass),
300 G_SIGNAL_RUN_LAST | G_SIGNAL_DETAILED,
301 G_STRUCT_OFFSET (GstPadClass, have_data),
302 _gst_do_pass_data_accumulator,
303 NULL, gst_marshal_BOOLEAN__POINTER, G_TYPE_BOOLEAN, 1,
304 GST_TYPE_MINI_OBJECT);
306 g_object_class_install_property (G_OBJECT_CLASS (klass), PAD_PROP_CAPS,
307 g_param_spec_boxed ("caps", "Caps", "The capabilities of the pad",
308 GST_TYPE_CAPS, G_PARAM_READABLE));
309 g_object_class_install_property (G_OBJECT_CLASS (klass), PAD_PROP_DIRECTION,
310 g_param_spec_enum ("direction", "Direction", "The direction of the pad",
311 GST_TYPE_PAD_DIRECTION, GST_PAD_UNKNOWN,
312 G_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY));
313 g_object_class_install_property (G_OBJECT_CLASS (klass), PAD_PROP_TEMPLATE,
314 g_param_spec_object ("template", "Template",
315 "The GstPadTemplate of this pad", GST_TYPE_PAD_TEMPLATE,
318 #ifndef GST_DISABLE_LOADSAVE
319 gstobject_class->save_thyself = GST_DEBUG_FUNCPTR (gst_pad_save_thyself);
321 gstobject_class->path_string_separator = ".";
323 klass->have_data = default_have_data;
327 gst_pad_init (GstPad * pad)
329 pad->direction = GST_PAD_UNKNOWN;
332 pad->chainfunc = NULL;
336 pad->linkfunc = NULL;
337 pad->getcapsfunc = NULL;
339 pad->activatefunc = GST_DEBUG_FUNCPTR (gst_pad_activate_default);
340 pad->eventfunc = GST_DEBUG_FUNCPTR (gst_pad_event_default);
341 pad->querytypefunc = GST_DEBUG_FUNCPTR (gst_pad_get_query_types_default);
342 pad->queryfunc = GST_DEBUG_FUNCPTR (gst_pad_query_default);
343 pad->intlinkfunc = GST_DEBUG_FUNCPTR (gst_pad_get_internal_links_default);
344 GST_PAD_ACCEPTCAPSFUNC (pad) = GST_DEBUG_FUNCPTR (gst_pad_acceptcaps_default);
346 pad->do_buffer_signals = 0;
347 pad->do_event_signals = 0;
349 GST_PAD_UNSET_FLUSHING (pad);
351 pad->preroll_lock = g_mutex_new ();
352 pad->preroll_cond = g_cond_new ();
354 pad->stream_rec_lock = g_new (GStaticRecMutex, 1);
355 g_static_rec_mutex_init (pad->stream_rec_lock);
357 pad->block_cond = g_cond_new ();
361 gst_pad_dispose (GObject * object)
363 GstPad *pad = GST_PAD (object);
365 GST_CAT_DEBUG (GST_CAT_REFCOUNTING, "dispose %s:%s",
366 GST_DEBUG_PAD_NAME (pad));
368 /* we don't hold a ref to the peer so we can just set the
370 GST_PAD_PEER (pad) = NULL;
373 gst_caps_replace (&GST_PAD_CAPS (pad), NULL);
375 gst_pad_set_pad_template (pad, NULL);
377 G_OBJECT_CLASS (parent_class)->dispose (object);
381 gst_pad_finalize (GObject * object)
383 GstPad *pad = GST_PAD (object);
386 /* in case the task is still around, clean it up */
387 if ((task = GST_PAD_TASK (pad))) {
388 gst_task_join (task);
389 GST_PAD_TASK (pad) = NULL;
390 gst_object_unref (task);
393 if (pad->stream_rec_lock) {
394 g_static_rec_mutex_free (pad->stream_rec_lock);
395 g_free (pad->stream_rec_lock);
396 pad->stream_rec_lock = NULL;
398 if (pad->preroll_lock) {
399 g_mutex_free (pad->preroll_lock);
400 g_cond_free (pad->preroll_cond);
401 pad->preroll_lock = NULL;
402 pad->preroll_cond = NULL;
404 if (pad->block_cond) {
405 g_cond_free (pad->block_cond);
406 pad->block_cond = NULL;
409 G_OBJECT_CLASS (parent_class)->finalize (object);
413 gst_pad_set_property (GObject * object, guint prop_id,
414 const GValue * value, GParamSpec * pspec)
416 g_return_if_fail (GST_IS_PAD (object));
419 case PAD_PROP_DIRECTION:
420 GST_PAD_DIRECTION (object) = g_value_get_enum (value);
422 case PAD_PROP_TEMPLATE:
423 gst_pad_set_pad_template (GST_PAD_CAST (object),
424 (GstPadTemplate *) g_value_dup_gst_object (value));
427 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
433 gst_pad_get_property (GObject * object, guint prop_id,
434 GValue * value, GParamSpec * pspec)
436 g_return_if_fail (GST_IS_PAD (object));
440 g_value_set_boxed (value, GST_PAD_CAPS (object));
442 case PAD_PROP_DIRECTION:
443 g_value_set_enum (value, GST_PAD_DIRECTION (object));
445 case PAD_PROP_TEMPLATE:
446 g_value_set_object (value, GST_PAD_PAD_TEMPLATE (object));
449 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
456 * @name: the name of the new pad.
457 * @direction: the #GstPadDirection of the pad.
459 * Creates a new pad with the given name in the given direction.
460 * If name is NULL, a guaranteed unique name (across all pads)
462 * This function makes a copy of the name so you can safely free the name.
464 * Returns: a new #GstPad, or NULL in case of an error.
469 gst_pad_new (const gchar * name, GstPadDirection direction)
471 return g_object_new (GST_TYPE_PAD,
472 "name", name, "direction", direction, NULL);
476 * gst_pad_new_from_template:
477 * @templ: the pad template to use
478 * @name: the name of the element
480 * Creates a new pad with the given name from the given template.
481 * If name is NULL, a guaranteed unique name (across all pads)
483 * This function makes a copy of the name so you can safely free the name.
485 * Returns: a new #GstPad, or NULL in case of an error.
488 gst_pad_new_from_template (GstPadTemplate * templ, const gchar * name)
490 g_return_val_if_fail (GST_IS_PAD_TEMPLATE (templ), NULL);
492 return g_object_new (GST_TYPE_PAD,
493 "name", name, "direction", templ->direction, "template", templ, NULL);
497 * gst_pad_new_from_static_template:
498 * @templ: the #GstStaticPadTemplate to use
499 * @name: the name of the element
501 * Creates a new pad with the given name from the given static template.
502 * If name is NULL, a guaranteed unique name (across all pads)
504 * This function makes a copy of the name so you can safely free the name.
506 * Returns: a new #GstPad, or NULL in case of an error.
509 gst_pad_new_from_static_template (GstStaticPadTemplate * templ,
513 GstPadTemplate *template;
515 template = gst_static_pad_template_get (templ);
516 pad = gst_pad_new_from_template (template, name);
517 gst_object_unref (template);
522 * gst_pad_get_direction:
523 * @pad: a #GstPad to get the direction of.
525 * Gets the direction of the pad. The direction of the pad is
526 * decided at construction time so this function does not take
529 * Returns: the #GstPadDirection of the pad.
534 gst_pad_get_direction (GstPad * pad)
536 GstPadDirection result;
538 /* PAD_UNKNOWN is a little silly but we need some sort of
539 * error return value */
540 g_return_val_if_fail (GST_IS_PAD (pad), GST_PAD_UNKNOWN);
542 GST_OBJECT_LOCK (pad);
543 result = GST_PAD_DIRECTION (pad);
544 GST_OBJECT_UNLOCK (pad);
550 gst_pad_activate_default (GstPad * pad)
552 return gst_pad_activate_push (pad, TRUE);
556 pre_activate (GstPad * pad, GstActivateMode new_mode)
559 case GST_ACTIVATE_PUSH:
560 case GST_ACTIVATE_PULL:
561 GST_OBJECT_LOCK (pad);
562 GST_DEBUG_OBJECT (pad, "setting ACTIVATE_MODE %d, unset flushing",
564 GST_PAD_UNSET_FLUSHING (pad);
565 GST_PAD_ACTIVATE_MODE (pad) = new_mode;
566 GST_OBJECT_UNLOCK (pad);
568 case GST_ACTIVATE_NONE:
569 GST_OBJECT_LOCK (pad);
570 GST_DEBUG_OBJECT (pad, "setting ACTIVATE_MODE NONE, set flushing",
572 GST_PAD_SET_FLUSHING (pad);
573 /* unlock blocked pads so element can resume and stop */
574 GST_PAD_BLOCK_SIGNAL (pad);
575 GST_OBJECT_UNLOCK (pad);
581 post_activate (GstPad * pad, GstActivateMode new_mode)
584 case GST_ACTIVATE_PUSH:
585 case GST_ACTIVATE_PULL:
588 case GST_ACTIVATE_NONE:
589 /* ensures that streaming stops */
590 GST_PAD_STREAM_LOCK (pad);
591 /* while we're at it set activation mode */
592 GST_OBJECT_LOCK (pad);
593 GST_DEBUG_OBJECT (pad, "setting ACTIVATE_MODE %d", new_mode);
594 GST_PAD_ACTIVATE_MODE (pad) = new_mode;
595 GST_OBJECT_UNLOCK (pad);
596 GST_PAD_STREAM_UNLOCK (pad);
602 * gst_pad_set_active:
603 * @pad: the #GstPad to activate or deactivate.
604 * @active: whether or not the pad should be active.
606 * Activates or deactivates the given pad.
607 * Normally called from within core state change functions.
609 * If @active, makes sure the pad is active. If it is already active, either in
610 * push or pull mode, just return. Otherwise dispatches to the pad's activate
611 * function to perform the actual activation.
613 * If not @active, checks the pad's current mode and calls
614 * gst_pad_activate_push() or gst_pad_activate_pull(), as appropriate, with a
617 * Returns: #TRUE if the operation was successful.
622 gst_pad_set_active (GstPad * pad, gboolean active)
625 gboolean ret = FALSE;
627 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
629 GST_OBJECT_LOCK (pad);
630 old = GST_PAD_ACTIVATE_MODE (pad);
631 GST_OBJECT_UNLOCK (pad);
635 case GST_ACTIVATE_PUSH:
636 case GST_ACTIVATE_PULL:
639 case GST_ACTIVATE_NONE:
640 ret = (GST_PAD_ACTIVATEFUNC (pad)) (pad);
645 case GST_ACTIVATE_PUSH:
646 ret = gst_pad_activate_push (pad, FALSE);
648 case GST_ACTIVATE_PULL:
649 ret = gst_pad_activate_pull (pad, FALSE);
651 case GST_ACTIVATE_NONE:
657 if (!active && !ret) {
658 GST_OBJECT_LOCK (pad);
659 g_critical ("Failed to deactivate pad %s:%s, very bad",
660 GST_DEBUG_PAD_NAME (pad));
661 GST_OBJECT_UNLOCK (pad);
668 * gst_pad_activate_pull:
669 * @pad: the #GstPad to activate or deactivate.
670 * @active: whether or not the pad should be active.
672 * Activates or deactivates the given pad in pull mode via dispatching to the
673 * pad's activatepullfunc. For use from within pad activation functions only.
674 * When called on sink pads, will first proxy the call to the peer pad, which is
675 * expected to activate its internally linked pads from within its activate_pull
678 * If you don't know what this is, you probably don't want to call it.
680 * Returns: TRUE if the operation was successful.
685 gst_pad_activate_pull (GstPad * pad, gboolean active)
687 GstActivateMode old, new;
690 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
692 GST_OBJECT_LOCK (pad);
693 old = GST_PAD_ACTIVATE_MODE (pad);
694 GST_OBJECT_UNLOCK (pad);
696 if ((active && old == GST_ACTIVATE_PULL)
697 || (!active && old == GST_ACTIVATE_NONE))
701 g_return_val_if_fail (old == GST_ACTIVATE_NONE, FALSE);
703 g_return_val_if_fail (old == GST_ACTIVATE_PULL, FALSE);
706 if (gst_pad_get_direction (pad) == GST_PAD_SINK) {
707 if ((peer = gst_pad_get_peer (pad))) {
708 if (!gst_pad_activate_pull (peer, active))
710 gst_object_unref (peer);
713 if (GST_PAD_GETRANGEFUNC (pad) == NULL)
714 goto failure; /* Can't activate pull on a src without a
718 new = active ? GST_ACTIVATE_PULL : GST_ACTIVATE_NONE;
719 pre_activate (pad, new);
721 if (GST_PAD_ACTIVATEPULLFUNC (pad)) {
722 if (!GST_PAD_ACTIVATEPULLFUNC (pad) (pad, active))
725 /* can happen for sinks of passthrough elements */
728 post_activate (pad, new);
730 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "%s in pull mode",
731 active ? "activated" : "deactivated");
736 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "already %s in pull mode",
737 active ? "activated" : "deactivated");
742 GST_OBJECT_LOCK (peer);
743 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
744 "activate_pull on peer (%s:%s) failed", GST_DEBUG_PAD_NAME (peer));
745 GST_OBJECT_UNLOCK (peer);
746 gst_object_unref (peer);
751 GST_CAT_INFO_OBJECT (GST_CAT_PADS, pad, "failed to %s in pull mode",
752 active ? "activate" : "deactivate");
753 pre_activate (pad, GST_ACTIVATE_NONE);
754 post_activate (pad, GST_ACTIVATE_NONE);
760 * gst_pad_activate_push:
761 * @pad: the #GstPad to activate or deactivate.
762 * @active: whether or not the pad should be active.
764 * Activates or deactivates the given pad in push mode via dispatching to the
765 * pad's activatepushfunc. For use from within pad activation functions only.
767 * If you don't know what this is, you probably don't want to call it.
769 * Returns: TRUE if the operation was successfull.
774 gst_pad_activate_push (GstPad * pad, gboolean active)
776 GstActivateMode old, new;
778 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
779 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "trying to set %s in push mode",
780 active ? "activated" : "deactivated");
782 GST_OBJECT_LOCK (pad);
783 old = GST_PAD_ACTIVATE_MODE (pad);
784 GST_OBJECT_UNLOCK (pad);
786 if ((active && old == GST_ACTIVATE_PUSH)
787 || (!active && old == GST_ACTIVATE_NONE))
791 g_return_val_if_fail (old == GST_ACTIVATE_NONE, FALSE);
793 g_return_val_if_fail (old == GST_ACTIVATE_PUSH, FALSE);
796 new = active ? GST_ACTIVATE_PUSH : GST_ACTIVATE_NONE;
797 pre_activate (pad, new);
799 if (GST_PAD_ACTIVATEPUSHFUNC (pad)) {
800 if (!GST_PAD_ACTIVATEPUSHFUNC (pad) (pad, active)) {
804 /* quite ok, element relies on state change func to prepare itself */
807 post_activate (pad, new);
809 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "%s in push mode",
810 active ? "activated" : "deactivated");
815 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "already %s in push mode",
816 active ? "activated" : "deactivated");
821 GST_CAT_INFO_OBJECT (GST_CAT_PADS, pad, "failed to %s in push mode",
822 active ? "activate" : "deactivate");
823 pre_activate (pad, GST_ACTIVATE_NONE);
824 post_activate (pad, GST_ACTIVATE_NONE);
831 * @pad: the #GstPad to query
833 * Query if a pad is active
835 * Returns: TRUE if the pad is active.
840 gst_pad_is_active (GstPad * pad)
842 gboolean result = FALSE;
844 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
846 GST_OBJECT_LOCK (pad);
847 result = GST_PAD_MODE_ACTIVATE (GST_PAD_ACTIVATE_MODE (pad));
848 GST_OBJECT_UNLOCK (pad);
854 * gst_pad_set_blocked_async:
855 * @pad: the #GstPad to block or unblock
856 * @blocked: boolean indicating whether the pad should be blocked or unblocked
857 * @callback: #GstPadBlockCallback that will be called when the
859 * @user_data: user data passed to the callback
861 * Blocks or unblocks the dataflow on a pad. The provided callback
862 * is called when the operation succeeds; this happens right before the next
863 * attempt at pushing a buffer on the pad.
865 * This can take a while as the pad can only become blocked when real dataflow
867 * When the pipeline is stalled, for example in PAUSED, this can
868 * take an indeterminate amount of time.
869 * You can pass NULL as the callback to make this call block. Be careful with
870 * this blocking call as it might not return for reasons stated above.
872 * Returns: TRUE if the pad could be blocked. This function can fail
873 * if wrong parameters were passed or the pad was already in the
879 gst_pad_set_blocked_async (GstPad * pad, gboolean blocked,
880 GstPadBlockCallback callback, gpointer user_data)
882 gboolean was_blocked, was_ghost = FALSE;
884 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
886 if (GST_IS_GHOST_PAD (pad)) {
887 pad = gst_ghost_pad_get_target (GST_GHOST_PAD (pad));
894 GST_OBJECT_LOCK (pad);
896 was_blocked = GST_PAD_IS_BLOCKED (pad);
898 if (G_UNLIKELY (was_blocked == blocked))
899 goto had_right_state;
902 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "blocking pad %s:%s",
903 GST_DEBUG_PAD_NAME (pad));
905 GST_OBJECT_FLAG_SET (pad, GST_PAD_BLOCKED);
906 pad->block_callback = callback;
907 pad->block_data = user_data;
909 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "waiting for block");
910 GST_PAD_BLOCK_WAIT (pad);
911 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "blocked");
914 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "unblocking pad %s:%s",
915 GST_DEBUG_PAD_NAME (pad));
917 GST_OBJECT_FLAG_UNSET (pad, GST_PAD_BLOCKED);
919 pad->block_callback = callback;
920 pad->block_data = user_data;
923 GST_PAD_BLOCK_SIGNAL (pad);
925 GST_PAD_BLOCK_SIGNAL (pad);
926 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "waiting for unblock");
927 GST_PAD_BLOCK_WAIT (pad);
928 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "unblocked");
931 GST_OBJECT_UNLOCK (pad);
934 gst_object_unref (pad);
941 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
942 "pad %s:%s was in right state", GST_DEBUG_PAD_NAME (pad));
943 GST_OBJECT_UNLOCK (pad);
946 gst_object_unref (pad);
953 * gst_pad_set_blocked:
954 * @pad: the #GstPad to block or unblock
955 * @blocked: boolean indicating we should block or unblock
957 * Blocks or unblocks the dataflow on a pad. This function is
958 * a shortcut for gst_pad_set_blocked_async() with a NULL
961 * Returns: TRUE if the pad could be blocked. This function can fail
962 * wrong parameters were passed or the pad was already in the
968 gst_pad_set_blocked (GstPad * pad, gboolean blocked)
970 return gst_pad_set_blocked_async (pad, blocked, NULL, NULL);
974 * gst_pad_is_blocked:
975 * @pad: the #GstPad to query
977 * Checks if the pad is blocked or not. This function returns the
978 * last requested state of the pad. It is not certain that the pad
979 * is actually blocked at this point.
981 * Returns: TRUE if the pad is blocked.
986 gst_pad_is_blocked (GstPad * pad)
988 gboolean result = FALSE;
990 g_return_val_if_fail (GST_IS_PAD (pad), result);
992 GST_OBJECT_LOCK (pad);
993 result = GST_OBJECT_FLAG_IS_SET (pad, GST_PAD_BLOCKED);
994 GST_OBJECT_UNLOCK (pad);
1000 * gst_pad_set_activate_function:
1001 * @pad: a sink #GstPad.
1002 * @activate: the #GstPadActivateFunction to set.
1004 * Sets the given activate function for the pad. The activate function will
1005 * dispatch to activate_push or activate_pull to perform the actual activation.
1006 * Only makes sense to set on sink pads.
1008 * Call this function if your sink pad can start a pull-based task.
1011 gst_pad_set_activate_function (GstPad * pad, GstPadActivateFunction activate)
1013 g_return_if_fail (GST_IS_PAD (pad));
1015 GST_PAD_ACTIVATEFUNC (pad) = activate;
1016 GST_CAT_DEBUG (GST_CAT_PADS, "activatefunc for %s:%s set to %s",
1017 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (activate));
1021 * gst_pad_set_activatepull_function:
1022 * @pad: a sink #GstPad.
1023 * @activatepull: the #GstPadActivateModeFunction to set.
1025 * Sets the given activate_pull function for the pad. An activate_pull function
1026 * prepares the element and any upstream connections for pulling. See XXX
1027 * part-activation.txt for details.
1030 gst_pad_set_activatepull_function (GstPad * pad,
1031 GstPadActivateModeFunction activatepull)
1033 g_return_if_fail (GST_IS_PAD (pad));
1035 GST_PAD_ACTIVATEPULLFUNC (pad) = activatepull;
1036 GST_CAT_DEBUG (GST_CAT_PADS, "activatepullfunc for %s:%s set to %s",
1037 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (activatepull));
1041 * gst_pad_set_activatepush_function:
1042 * @pad: a sink #GstPad.
1043 * @activatepush: the #GstPadActivateModeFunction to set.
1045 * Sets the given activate_push function for the pad. An activate_push function
1046 * prepares the element for pushing. See XXX part-activation.txt for details.
1049 gst_pad_set_activatepush_function (GstPad * pad,
1050 GstPadActivateModeFunction activatepush)
1052 g_return_if_fail (GST_IS_PAD (pad));
1054 GST_PAD_ACTIVATEPUSHFUNC (pad) = activatepush;
1055 GST_CAT_DEBUG (GST_CAT_PADS, "activatepushfunc for %s:%s set to %s",
1056 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (activatepush));
1060 * gst_pad_set_chain_function:
1061 * @pad: a sink #GstPad.
1062 * @chain: the #GstPadChainFunction to set.
1064 * Sets the given chain function for the pad. The chain function is called to
1065 * process a #GstBuffer input buffer.
1068 gst_pad_set_chain_function (GstPad * pad, GstPadChainFunction chain)
1070 g_return_if_fail (GST_IS_PAD (pad));
1071 g_return_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SINK);
1073 GST_PAD_CHAINFUNC (pad) = chain;
1074 GST_CAT_DEBUG (GST_CAT_PADS, "chainfunc for %s:%s set to %s",
1075 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (chain));
1079 * gst_pad_set_getrange_function:
1080 * @pad: a source #GstPad.
1081 * @get: the #GstPadGetRangeFunction to set.
1083 * Sets the given getrange function for the pad. The getrange function is called to
1084 * produce a new #GstBuffer to start the processing pipeline. Getrange functions cannot
1088 gst_pad_set_getrange_function (GstPad * pad, GstPadGetRangeFunction get)
1090 g_return_if_fail (GST_IS_PAD (pad));
1091 g_return_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SRC);
1093 GST_PAD_GETRANGEFUNC (pad) = get;
1095 GST_CAT_DEBUG (GST_CAT_PADS, "getrangefunc for %s:%s set to %s",
1096 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (get));
1100 * gst_pad_set_checkgetrange_function:
1101 * @pad: a source #GstPad.
1102 * @check: the #GstPadCheckGetRangeFunction to set.
1104 * Sets the given checkgetrange function for the pad. Implement this function on
1105 * a pad if you dynamically support getrange based scheduling on the pad.
1108 gst_pad_set_checkgetrange_function (GstPad * pad,
1109 GstPadCheckGetRangeFunction check)
1111 g_return_if_fail (GST_IS_PAD (pad));
1112 g_return_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SRC);
1114 GST_PAD_CHECKGETRANGEFUNC (pad) = check;
1116 GST_CAT_DEBUG (GST_CAT_PADS, "checkgetrangefunc for %s:%s set to %s",
1117 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (check));
1121 * gst_pad_set_event_function:
1122 * @pad: a source #GstPad.
1123 * @event: the #GstPadEventFunction to set.
1125 * Sets the given event handler for the pad.
1128 gst_pad_set_event_function (GstPad * pad, GstPadEventFunction event)
1130 g_return_if_fail (GST_IS_PAD (pad));
1132 GST_PAD_EVENTFUNC (pad) = event;
1134 GST_CAT_DEBUG (GST_CAT_PADS, "eventfunc for %s:%s set to %s",
1135 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (event));
1139 * gst_pad_set_query_function:
1140 * @pad: a #GstPad of either direction.
1141 * @query: the #GstPadQueryFunction to set.
1143 * Set the given query function for the pad.
1146 gst_pad_set_query_function (GstPad * pad, GstPadQueryFunction query)
1148 g_return_if_fail (GST_IS_PAD (pad));
1150 GST_PAD_QUERYFUNC (pad) = query;
1152 GST_CAT_DEBUG (GST_CAT_PADS, "queryfunc for %s:%s set to %s",
1153 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (query));
1157 * gst_pad_set_query_type_function:
1158 * @pad: a #GstPad of either direction.
1159 * @type_func: the #GstPadQueryTypeFunction to set.
1161 * Set the given query type function for the pad.
1164 gst_pad_set_query_type_function (GstPad * pad,
1165 GstPadQueryTypeFunction type_func)
1167 g_return_if_fail (GST_IS_PAD (pad));
1169 GST_PAD_QUERYTYPEFUNC (pad) = type_func;
1171 GST_CAT_DEBUG (GST_CAT_PADS, "querytypefunc for %s:%s set to %s",
1172 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (type_func));
1176 * gst_pad_get_query_types:
1179 * Get an array of supported queries that can be performed
1182 * Returns: a zero-terminated array of #GstQueryType.
1184 const GstQueryType *
1185 gst_pad_get_query_types (GstPad * pad)
1187 GstPadQueryTypeFunction func;
1189 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
1191 if (G_UNLIKELY ((func = GST_PAD_QUERYTYPEFUNC (pad)) == NULL))
1203 gst_pad_get_query_types_dispatcher (GstPad * pad, const GstQueryType ** data)
1205 *data = gst_pad_get_query_types (pad);
1211 * gst_pad_get_query_types_default:
1214 * Invoke the default dispatcher for the query types on
1217 * Returns: an zero-terminated array of #GstQueryType, or NULL if none of the
1218 * internally-linked pads has a query types function.
1220 const GstQueryType *
1221 gst_pad_get_query_types_default (GstPad * pad)
1223 GstQueryType *result = NULL;
1225 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
1227 gst_pad_dispatcher (pad, (GstPadDispatcherFunction)
1228 gst_pad_get_query_types_dispatcher, &result);
1234 * gst_pad_set_internal_link_function:
1235 * @pad: a #GstPad of either direction.
1236 * @intlink: the #GstPadIntLinkFunction to set.
1238 * Sets the given internal link function for the pad.
1241 gst_pad_set_internal_link_function (GstPad * pad, GstPadIntLinkFunction intlink)
1243 g_return_if_fail (GST_IS_PAD (pad));
1245 GST_PAD_INTLINKFUNC (pad) = intlink;
1246 GST_CAT_DEBUG (GST_CAT_PADS, "internal link for %s:%s set to %s",
1247 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (intlink));
1251 * gst_pad_set_link_function:
1253 * @link: the #GstPadLinkFunction to set.
1255 * Sets the given link function for the pad. It will be called when
1256 * the pad is linked with another pad.
1258 * The return value #GST_PAD_LINK_OK should be used when the connection can be
1261 * The return value #GST_PAD_LINK_REFUSED should be used when the connection
1262 * cannot be made for some reason.
1264 * If @link is installed on a source pad, it should call the #GstPadLinkFunction
1265 * of the peer sink pad, if present.
1268 gst_pad_set_link_function (GstPad * pad, GstPadLinkFunction link)
1270 g_return_if_fail (GST_IS_PAD (pad));
1272 GST_PAD_LINKFUNC (pad) = link;
1273 GST_CAT_DEBUG (GST_CAT_PADS, "linkfunc for %s:%s set to %s",
1274 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (link));
1278 * gst_pad_set_unlink_function:
1280 * @unlink: the #GstPadUnlinkFunction to set.
1282 * Sets the given unlink function for the pad. It will be called
1283 * when the pad is unlinked.
1286 gst_pad_set_unlink_function (GstPad * pad, GstPadUnlinkFunction unlink)
1288 g_return_if_fail (GST_IS_PAD (pad));
1290 GST_PAD_UNLINKFUNC (pad) = unlink;
1291 GST_CAT_DEBUG (GST_CAT_PADS, "unlinkfunc for %s:%s set to %s",
1292 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (unlink));
1296 * gst_pad_set_getcaps_function:
1298 * @getcaps: the #GstPadGetCapsFunction to set.
1300 * Sets the given getcaps function for the pad. @getcaps should return the
1301 * allowable caps for a pad in the context of the element's state, its link to
1302 * other elements, and the devices or files it has opened. These caps must be a
1303 * subset of the pad template caps. In the NULL state with no links, @getcaps
1304 * should ideally return the same caps as the pad template. In rare
1305 * circumstances, an object property can affect the caps returned by @getcaps,
1306 * but this is discouraged.
1308 * You do not need to call this function if @pad's allowed caps are always the
1309 * same as the pad template caps. This can only be true if the padtemplate
1310 * has fixed simple caps.
1312 * For most filters, the caps returned by @getcaps is directly affected by the
1313 * allowed caps on other pads. For demuxers and decoders, the caps returned by
1314 * the srcpad's getcaps function is directly related to the stream data. Again,
1315 * @getcaps should return the most specific caps it reasonably can, since this
1316 * helps with autoplugging.
1318 * Note that the return value from @getcaps is owned by the caller, so the caller
1319 * should unref the caps after usage.
1322 gst_pad_set_getcaps_function (GstPad * pad, GstPadGetCapsFunction getcaps)
1324 g_return_if_fail (GST_IS_PAD (pad));
1326 GST_PAD_GETCAPSFUNC (pad) = getcaps;
1327 GST_CAT_DEBUG (GST_CAT_PADS, "getcapsfunc for %s:%s set to %s",
1328 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (getcaps));
1332 * gst_pad_set_acceptcaps_function:
1334 * @acceptcaps: the #GstPadAcceptCapsFunction to set.
1336 * Sets the given acceptcaps function for the pad. The acceptcaps function
1337 * will be called to check if the pad can accept the given caps. Setting the
1338 * acceptcaps function to NULL restores the default behaviour of allowing
1339 * any caps that matches the caps from gst_pad_get_caps.
1342 gst_pad_set_acceptcaps_function (GstPad * pad,
1343 GstPadAcceptCapsFunction acceptcaps)
1345 g_return_if_fail (GST_IS_PAD (pad));
1347 GST_PAD_ACCEPTCAPSFUNC (pad) = acceptcaps;
1348 GST_CAT_DEBUG (GST_CAT_PADS, "acceptcapsfunc for %s:%s set to %s",
1349 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (acceptcaps));
1353 * gst_pad_set_fixatecaps_function:
1355 * @fixatecaps: the #GstPadFixateCapsFunction to set.
1357 * Sets the given fixatecaps function for the pad. The fixatecaps function
1358 * will be called whenever the default values for a GstCaps needs to be
1362 gst_pad_set_fixatecaps_function (GstPad * pad,
1363 GstPadFixateCapsFunction fixatecaps)
1365 g_return_if_fail (GST_IS_PAD (pad));
1367 GST_PAD_FIXATECAPSFUNC (pad) = fixatecaps;
1368 GST_CAT_DEBUG (GST_CAT_PADS, "fixatecapsfunc for %s:%s set to %s",
1369 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (fixatecaps));
1373 * gst_pad_set_setcaps_function:
1375 * @setcaps: the #GstPadSetCapsFunction to set.
1377 * Sets the given setcaps function for the pad. The setcaps function
1378 * will be called whenever a buffer with a new media type is pushed or
1379 * pulled from the pad. The pad/element needs to update it's internal
1380 * structures to process the new media type. If this new type is not
1381 * acceptable, the setcaps function should return FALSE.
1384 gst_pad_set_setcaps_function (GstPad * pad, GstPadSetCapsFunction setcaps)
1386 g_return_if_fail (GST_IS_PAD (pad));
1388 GST_PAD_SETCAPSFUNC (pad) = setcaps;
1389 GST_CAT_DEBUG (GST_CAT_PADS, "setcapsfunc for %s:%s set to %s",
1390 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (setcaps));
1394 * gst_pad_set_bufferalloc_function:
1395 * @pad: a sink #GstPad.
1396 * @bufalloc: the #GstPadBufferAllocFunction to set.
1398 * Sets the given bufferalloc function for the pad. Note that the
1399 * bufferalloc function can only be set on sinkpads.
1402 gst_pad_set_bufferalloc_function (GstPad * pad,
1403 GstPadBufferAllocFunction bufalloc)
1405 g_return_if_fail (GST_IS_PAD (pad));
1406 g_return_if_fail (GST_PAD_IS_SINK (pad));
1408 GST_PAD_BUFFERALLOCFUNC (pad) = bufalloc;
1409 GST_CAT_DEBUG (GST_CAT_PADS, "bufferallocfunc for %s:%s set to %s",
1410 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (bufalloc));
1415 * @srcpad: the source #GstPad to unlink.
1416 * @sinkpad: the sink #GstPad to unlink.
1418 * Unlinks the source pad from the sink pad. Will emit the "unlinked" signal on
1421 * Returns: TRUE if the pads were unlinked. This function returns FALSE if
1422 * the pads were not linked together.
1427 gst_pad_unlink (GstPad * srcpad, GstPad * sinkpad)
1429 g_return_val_if_fail (GST_IS_PAD (srcpad), FALSE);
1430 g_return_val_if_fail (GST_IS_PAD (sinkpad), FALSE);
1432 GST_CAT_INFO (GST_CAT_ELEMENT_PADS, "unlinking %s:%s(%p) and %s:%s(%p)",
1433 GST_DEBUG_PAD_NAME (srcpad), srcpad,
1434 GST_DEBUG_PAD_NAME (sinkpad), sinkpad);
1436 GST_OBJECT_LOCK (srcpad);
1438 if (G_UNLIKELY (GST_PAD_DIRECTION (srcpad) != GST_PAD_SRC))
1441 GST_OBJECT_LOCK (sinkpad);
1443 if (G_UNLIKELY (GST_PAD_DIRECTION (sinkpad) != GST_PAD_SINK))
1446 if (G_UNLIKELY (GST_PAD_PEER (srcpad) != sinkpad))
1447 goto not_linked_together;
1449 if (GST_PAD_UNLINKFUNC (srcpad)) {
1450 GST_PAD_UNLINKFUNC (srcpad) (srcpad);
1452 if (GST_PAD_UNLINKFUNC (sinkpad)) {
1453 GST_PAD_UNLINKFUNC (sinkpad) (sinkpad);
1456 /* first clear peers */
1457 GST_PAD_PEER (srcpad) = NULL;
1458 GST_PAD_PEER (sinkpad) = NULL;
1460 GST_OBJECT_UNLOCK (sinkpad);
1461 GST_OBJECT_UNLOCK (srcpad);
1463 /* fire off a signal to each of the pads telling them
1464 * that they've been unlinked */
1465 g_signal_emit (G_OBJECT (srcpad), gst_pad_signals[PAD_UNLINKED], 0, sinkpad);
1466 g_signal_emit (G_OBJECT (sinkpad), gst_pad_signals[PAD_UNLINKED], 0, srcpad);
1468 GST_CAT_INFO (GST_CAT_ELEMENT_PADS, "unlinked %s:%s and %s:%s",
1469 GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (sinkpad));
1475 g_critical ("pad %s is not a source pad", GST_PAD_NAME (srcpad));
1476 GST_OBJECT_UNLOCK (srcpad);
1481 g_critical ("pad %s is not a sink pad", GST_PAD_NAME (sinkpad));
1482 GST_OBJECT_UNLOCK (sinkpad);
1483 GST_OBJECT_UNLOCK (srcpad);
1486 not_linked_together:
1488 /* we do not emit a warning in this case because unlinking cannot
1489 * be made MT safe.*/
1490 GST_OBJECT_UNLOCK (sinkpad);
1491 GST_OBJECT_UNLOCK (srcpad);
1497 * gst_pad_is_linked:
1498 * @pad: pad to check
1500 * Checks if a @pad is linked to another pad or not.
1502 * Returns: TRUE if the pad is linked, FALSE otherwise.
1507 gst_pad_is_linked (GstPad * pad)
1511 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
1513 GST_OBJECT_LOCK (pad);
1514 result = (GST_PAD_PEER (pad) != NULL);
1515 GST_OBJECT_UNLOCK (pad);
1520 /* get the caps from both pads and see if the intersection
1523 * This function should be called with the pad LOCK on both
1527 gst_pad_link_check_compatible_unlocked (GstPad * src, GstPad * sink)
1533 srccaps = gst_pad_get_caps_unlocked (src);
1534 sinkcaps = gst_pad_get_caps_unlocked (sink);
1536 GST_CAT_DEBUG (GST_CAT_CAPS, "src caps %" GST_PTR_FORMAT, srccaps);
1537 GST_CAT_DEBUG (GST_CAT_CAPS, "sink caps %" GST_PTR_FORMAT, sinkcaps);
1539 /* if we have caps on both pads we can check the intersection. If one
1540 * of the caps is NULL, we return TRUE. */
1541 if (srccaps == NULL || sinkcaps == NULL)
1544 icaps = gst_caps_intersect (srccaps, sinkcaps);
1545 gst_caps_unref (srccaps);
1546 gst_caps_unref (sinkcaps);
1551 GST_CAT_DEBUG (GST_CAT_CAPS,
1552 "intersection caps %p %" GST_PTR_FORMAT, icaps, icaps);
1554 if (gst_caps_is_empty (icaps))
1557 gst_caps_unref (icaps);
1562 /* incompatible cases */
1565 GST_CAT_DEBUG (GST_CAT_CAPS, "intersection gave NULL");
1570 GST_CAT_DEBUG (GST_CAT_CAPS, "intersection is EMPTY");
1571 gst_caps_unref (icaps);
1576 /* check if the grandparents of both pads are the same.
1577 * This check is required so that we don't try to link
1578 * pads from elements in different bins without ghostpads.
1580 * The LOCK should be helt on both pads
1583 gst_pad_link_check_hierarchy (GstPad * src, GstPad * sink)
1585 GstObject *psrc, *psink;
1586 gboolean res = TRUE;
1588 psrc = GST_OBJECT_PARENT (src);
1589 psink = GST_OBJECT_PARENT (sink);
1591 /* if one of the pads has no parent, we allow the link */
1592 if (psrc && psink) {
1593 /* if the parents are the same, we have a loop */
1594 if (psrc == psink) {
1595 GST_CAT_DEBUG (GST_CAT_CAPS, "pads have same parent %" GST_PTR_FORMAT,
1600 /* if they both have a parent, we check the grandparents */
1601 psrc = gst_object_get_parent (psrc);
1602 psink = gst_object_get_parent (psink);
1604 if (psrc != psink) {
1605 /* if they have grandparents but they are not the same */
1606 GST_CAT_DEBUG (GST_CAT_CAPS,
1607 "pads have different grandparents %" GST_PTR_FORMAT " and %"
1608 GST_PTR_FORMAT, psrc, psink);
1612 gst_object_unref (psrc);
1614 gst_object_unref (psink);
1620 /* FIXME leftover from an attempt at refactoring... */
1621 /* call with the two pads unlocked */
1622 static GstPadLinkReturn
1623 gst_pad_link_prepare (GstPad * srcpad, GstPad * sinkpad)
1625 /* generic checks */
1626 g_return_val_if_fail (GST_IS_PAD (srcpad), GST_PAD_LINK_REFUSED);
1627 g_return_val_if_fail (GST_IS_PAD (sinkpad), GST_PAD_LINK_REFUSED);
1629 GST_CAT_INFO (GST_CAT_PADS, "trying to link %s:%s and %s:%s",
1630 GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (sinkpad));
1632 GST_OBJECT_LOCK (srcpad);
1634 if (G_UNLIKELY (GST_PAD_DIRECTION (srcpad) != GST_PAD_SRC))
1637 if (G_UNLIKELY (GST_PAD_PEER (srcpad) != NULL))
1638 goto src_was_linked;
1640 GST_OBJECT_LOCK (sinkpad);
1642 if (G_UNLIKELY (GST_PAD_DIRECTION (sinkpad) != GST_PAD_SINK))
1645 if (G_UNLIKELY (GST_PAD_PEER (sinkpad) != NULL))
1646 goto sink_was_linked;
1648 /* check hierarchy, pads can only be linked if the grandparents
1650 if (!gst_pad_link_check_hierarchy (srcpad, sinkpad))
1651 goto wrong_hierarchy;
1653 /* check pad caps for non-empty intersection */
1654 if (!gst_pad_link_check_compatible_unlocked (srcpad, sinkpad))
1657 /* FIXME check pad scheduling for non-empty intersection */
1659 return GST_PAD_LINK_OK;
1663 g_critical ("pad %s is not a source pad", GST_PAD_NAME (srcpad));
1664 GST_OBJECT_UNLOCK (srcpad);
1665 return GST_PAD_LINK_WRONG_DIRECTION;
1669 GST_CAT_INFO (GST_CAT_PADS, "src %s:%s was already linked",
1670 GST_DEBUG_PAD_NAME (srcpad));
1671 /* we do not emit a warning in this case because unlinking cannot
1672 * be made MT safe.*/
1673 GST_OBJECT_UNLOCK (srcpad);
1674 return GST_PAD_LINK_WAS_LINKED;
1678 g_critical ("pad %s is not a sink pad", GST_PAD_NAME (sinkpad));
1679 GST_OBJECT_UNLOCK (sinkpad);
1680 GST_OBJECT_UNLOCK (srcpad);
1681 return GST_PAD_LINK_WRONG_DIRECTION;
1685 GST_CAT_INFO (GST_CAT_PADS, "sink %s:%s was already linked",
1686 GST_DEBUG_PAD_NAME (sinkpad));
1687 /* we do not emit a warning in this case because unlinking cannot
1688 * be made MT safe.*/
1689 GST_OBJECT_UNLOCK (sinkpad);
1690 GST_OBJECT_UNLOCK (srcpad);
1691 return GST_PAD_LINK_WAS_LINKED;
1695 GST_CAT_INFO (GST_CAT_PADS, "pads have wrong hierarchy");
1696 GST_OBJECT_UNLOCK (sinkpad);
1697 GST_OBJECT_UNLOCK (srcpad);
1698 return GST_PAD_LINK_WRONG_HIERARCHY;
1702 GST_CAT_INFO (GST_CAT_PADS, "caps are incompatible");
1703 GST_OBJECT_UNLOCK (sinkpad);
1704 GST_OBJECT_UNLOCK (srcpad);
1705 return GST_PAD_LINK_NOFORMAT;
1711 * @srcpad: the source #GstPad to link.
1712 * @sinkpad: the sink #GstPad to link.
1714 * Links the source pad and the sink pad.
1716 * Returns: A result code indicating if the connection worked or
1722 gst_pad_link (GstPad * srcpad, GstPad * sinkpad)
1724 GstPadLinkReturn result;
1726 /* prepare will also lock the two pads */
1727 result = gst_pad_link_prepare (srcpad, sinkpad);
1729 if (result != GST_PAD_LINK_OK)
1730 goto prepare_failed;
1732 GST_OBJECT_UNLOCK (sinkpad);
1733 GST_OBJECT_UNLOCK (srcpad);
1735 /* FIXME released the locks here, concurrent thread might link
1736 * something else. */
1737 if (GST_PAD_LINKFUNC (srcpad)) {
1738 /* this one will call the peer link function */
1739 result = GST_PAD_LINKFUNC (srcpad) (srcpad, sinkpad);
1740 } else if (GST_PAD_LINKFUNC (sinkpad)) {
1741 /* if no source link function, we need to call the sink link
1742 * function ourselves. */
1743 result = GST_PAD_LINKFUNC (sinkpad) (sinkpad, srcpad);
1745 result = GST_PAD_LINK_OK;
1748 GST_OBJECT_LOCK (srcpad);
1749 GST_OBJECT_LOCK (sinkpad);
1751 if (result == GST_PAD_LINK_OK) {
1752 GST_PAD_PEER (srcpad) = sinkpad;
1753 GST_PAD_PEER (sinkpad) = srcpad;
1755 GST_OBJECT_UNLOCK (sinkpad);
1756 GST_OBJECT_UNLOCK (srcpad);
1758 /* fire off a signal to each of the pads telling them
1759 * that they've been linked */
1760 g_signal_emit (G_OBJECT (srcpad), gst_pad_signals[PAD_LINKED], 0, sinkpad);
1761 g_signal_emit (G_OBJECT (sinkpad), gst_pad_signals[PAD_LINKED], 0, srcpad);
1763 GST_CAT_INFO (GST_CAT_PADS, "linked %s:%s and %s:%s, successful",
1764 GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (sinkpad));
1766 GST_CAT_INFO (GST_CAT_PADS, "link between %s:%s and %s:%s failed",
1767 GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (sinkpad));
1769 GST_OBJECT_UNLOCK (sinkpad);
1770 GST_OBJECT_UNLOCK (srcpad);
1781 gst_pad_set_pad_template (GstPad * pad, GstPadTemplate * templ)
1783 GstPadTemplate **template_p;
1785 /* this function would need checks if it weren't static */
1787 GST_OBJECT_LOCK (pad);
1788 template_p = &pad->padtemplate;
1789 gst_object_replace ((GstObject **) template_p, (GstObject *) templ);
1790 GST_OBJECT_UNLOCK (pad);
1793 gst_pad_template_pad_created (templ, pad);
1797 * gst_pad_get_pad_template:
1800 * Gets the template for @pad.
1802 * Returns: the #GstPadTemplate from which this pad was instantiated, or %NULL
1803 * if this pad has no template.
1805 * FIXME: currently returns an unrefcounted padtemplate.
1808 gst_pad_get_pad_template (GstPad * pad)
1810 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
1812 return GST_PAD_PAD_TEMPLATE (pad);
1816 /* should be called with the pad LOCK held */
1817 /* refs the caps, so caller is responsible for getting it unreffed */
1819 gst_pad_get_caps_unlocked (GstPad * pad)
1821 GstCaps *result = NULL;
1823 GST_CAT_DEBUG (GST_CAT_CAPS, "get pad caps of %s:%s (%p)",
1824 GST_DEBUG_PAD_NAME (pad), pad);
1826 if (GST_PAD_GETCAPSFUNC (pad)) {
1827 GST_CAT_DEBUG (GST_CAT_CAPS, "dispatching to pad getcaps function");
1829 GST_OBJECT_FLAG_SET (pad, GST_PAD_IN_GETCAPS);
1830 GST_OBJECT_UNLOCK (pad);
1831 result = GST_PAD_GETCAPSFUNC (pad) (pad);
1832 GST_OBJECT_LOCK (pad);
1833 GST_OBJECT_FLAG_UNSET (pad, GST_PAD_IN_GETCAPS);
1835 if (result == NULL) {
1836 g_critical ("pad %s:%s returned NULL caps from getcaps function",
1837 GST_DEBUG_PAD_NAME (pad));
1839 GST_CAT_DEBUG (GST_CAT_CAPS,
1840 "pad getcaps %s:%s returned %" GST_PTR_FORMAT,
1841 GST_DEBUG_PAD_NAME (pad), result);
1842 #ifndef G_DISABLE_ASSERT
1843 /* check that the returned caps are a real subset of the template caps */
1844 if (GST_PAD_PAD_TEMPLATE (pad)) {
1845 const GstCaps *templ_caps =
1846 GST_PAD_TEMPLATE_CAPS (GST_PAD_PAD_TEMPLATE (pad));
1847 if (!gst_caps_is_subset (result, templ_caps)) {
1850 GST_CAT_ERROR_OBJECT (GST_CAT_CAPS, pad,
1851 "pad returned caps %" GST_PTR_FORMAT
1852 " which are not a real subset of its template caps %"
1853 GST_PTR_FORMAT, result, templ_caps);
1855 ("pad %s:%s returned caps that are not a real subset of its template caps",
1856 GST_DEBUG_PAD_NAME (pad));
1857 temp = gst_caps_intersect (templ_caps, result);
1858 gst_caps_unref (result);
1866 if (GST_PAD_PAD_TEMPLATE (pad)) {
1867 GstPadTemplate *templ = GST_PAD_PAD_TEMPLATE (pad);
1869 result = GST_PAD_TEMPLATE_CAPS (templ);
1870 GST_CAT_DEBUG (GST_CAT_CAPS,
1871 "using pad template %p with caps %p %" GST_PTR_FORMAT, templ, result,
1874 result = gst_caps_ref (result);
1877 if (GST_PAD_CAPS (pad)) {
1878 result = GST_PAD_CAPS (pad);
1880 GST_CAT_DEBUG (GST_CAT_CAPS,
1881 "using pad caps %p %" GST_PTR_FORMAT, result, result);
1883 result = gst_caps_ref (result);
1887 GST_CAT_DEBUG (GST_CAT_CAPS, "pad has no caps");
1888 result = gst_caps_new_empty ();
1896 * @pad: a #GstPad to get the capabilities of.
1898 * Gets the capabilities this pad can produce or consume.
1899 * Note that this method doesn't necessarily returns the caps set by
1900 * gst_pad_set_caps() - use #GST_PAD_CAPS for that instead.
1901 * gst_pad_get_caps returns all possible caps a pad can operate with, using
1902 * the pad's get_caps function;
1903 * this returns the pad template caps if not explicitly set.
1905 * Returns: a newly allocated copy of the #GstCaps of this pad.
1910 gst_pad_get_caps (GstPad * pad)
1912 GstCaps *result = NULL;
1914 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
1916 GST_OBJECT_LOCK (pad);
1918 GST_CAT_DEBUG (GST_CAT_CAPS, "get pad caps of %s:%s (%p)",
1919 GST_DEBUG_PAD_NAME (pad), pad);
1921 result = gst_pad_get_caps_unlocked (pad);
1922 GST_OBJECT_UNLOCK (pad);
1928 * gst_pad_peer_get_caps:
1929 * @pad: a #GstPad to get the peer capabilities of.
1931 * Gets the capabilities of the peer connected to this pad.
1933 * Returns: the #GstCaps of the peer pad. This function returns a new caps, so use
1934 * gst_caps_unref to get rid of it. this function returns NULL if there is no
1938 gst_pad_peer_get_caps (GstPad * pad)
1941 GstCaps *result = NULL;
1943 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
1945 GST_OBJECT_LOCK (pad);
1947 GST_CAT_DEBUG (GST_CAT_CAPS, "get peer caps of %s:%s (%p)",
1948 GST_DEBUG_PAD_NAME (pad), pad);
1950 peerpad = GST_PAD_PEER (pad);
1951 if (G_UNLIKELY (peerpad == NULL))
1954 gst_object_ref (peerpad);
1955 GST_OBJECT_UNLOCK (pad);
1957 result = gst_pad_get_caps (peerpad);
1959 gst_object_unref (peerpad);
1965 GST_OBJECT_UNLOCK (pad);
1971 fixate_value (GValue * dest, const GValue * src)
1973 if (G_VALUE_TYPE (src) == GST_TYPE_INT_RANGE) {
1974 g_value_init (dest, G_TYPE_INT);
1975 g_value_set_int (dest, gst_value_get_int_range_min (src));
1976 } else if (G_VALUE_TYPE (src) == GST_TYPE_DOUBLE_RANGE) {
1977 g_value_init (dest, G_TYPE_DOUBLE);
1978 g_value_set_double (dest, gst_value_get_double_range_min (src));
1979 } else if (G_VALUE_TYPE (src) == GST_TYPE_FRACTION_RANGE) {
1980 gst_value_init_and_copy (dest, gst_value_get_fraction_range_min (src));
1981 } else if (G_VALUE_TYPE (src) == GST_TYPE_LIST) {
1982 GValue temp = { 0 };
1984 gst_value_init_and_copy (&temp, gst_value_list_get_value (src, 0));
1985 if (!fixate_value (dest, &temp))
1986 gst_value_init_and_copy (dest, &temp);
1987 g_value_unset (&temp);
1988 } else if (G_VALUE_TYPE (src) == GST_TYPE_ARRAY) {
1989 gboolean res = FALSE;
1992 g_value_init (dest, GST_TYPE_ARRAY);
1993 for (n = 0; n < gst_value_array_get_size (src); n++) {
1995 const GValue *orig_kid = gst_value_array_get_value (src, n);
1997 if (!fixate_value (&kid, orig_kid))
1998 gst_value_init_and_copy (&kid, orig_kid);
2001 gst_value_array_append_value (dest, &kid);
2002 g_value_unset (&kid);
2006 g_value_unset (dest);
2017 gst_pad_default_fixate (GQuark field_id, const GValue * value, gpointer data)
2019 GstStructure *s = data;
2022 if (fixate_value (&v, value)) {
2023 gst_structure_id_set_value (s, field_id, &v);
2031 * gst_pad_fixate_caps:
2032 * @pad: a #GstPad to fixate
2033 * @caps: the #GstCaps to fixate
2035 * Fixate a caps on the given pad. Modifies the caps in place, so you should
2036 * make sure that the caps are actually writable (see gst_caps_make_writable()).
2039 gst_pad_fixate_caps (GstPad * pad, GstCaps * caps)
2041 GstPadFixateCapsFunction fixatefunc;
2044 g_return_if_fail (GST_IS_PAD (pad));
2045 g_return_if_fail (caps != NULL);
2047 if (gst_caps_is_fixed (caps))
2050 fixatefunc = GST_PAD_FIXATECAPSFUNC (pad);
2052 fixatefunc (pad, caps);
2055 /* default fixation */
2056 for (n = 0; n < gst_caps_get_size (caps); n++) {
2057 GstStructure *s = gst_caps_get_structure (caps, n);
2059 gst_structure_foreach (s, gst_pad_default_fixate, s);
2063 /* Default accept caps implementation just checks against
2064 * against the allowed caps for the pad */
2066 gst_pad_acceptcaps_default (GstPad * pad, GstCaps * caps)
2068 /* get the caps and see if it intersects to something
2072 gboolean result = FALSE;
2074 allowed = gst_pad_get_caps (pad);
2076 intersect = gst_caps_intersect (allowed, caps);
2078 result = !gst_caps_is_empty (intersect);
2080 gst_caps_unref (allowed);
2081 gst_caps_unref (intersect);
2088 * gst_pad_accept_caps:
2089 * @pad: a #GstPad to check
2090 * @caps: a #GstCaps to check on the pad
2092 * Check if the given pad accepts the caps.
2094 * Returns: TRUE if the pad can accept the caps.
2097 gst_pad_accept_caps (GstPad * pad, GstCaps * caps)
2100 GstPadAcceptCapsFunction acceptfunc;
2101 GstCaps *existing = NULL;
2103 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2105 /* any pad can be unnegotiated */
2109 GST_OBJECT_LOCK (pad);
2110 acceptfunc = GST_PAD_ACCEPTCAPSFUNC (pad);
2111 if (GST_PAD_CAPS (pad) != NULL)
2112 existing = gst_caps_ref (GST_PAD_CAPS (pad));
2114 GST_CAT_DEBUG (GST_CAT_CAPS, "pad accept caps of %s:%s (%p)",
2115 GST_DEBUG_PAD_NAME (pad), pad);
2116 GST_OBJECT_UNLOCK (pad);
2118 /* The current caps on a pad are trivially acceptable */
2120 if (caps == existing || gst_caps_is_equal (caps, existing))
2122 gst_caps_unref (existing);
2125 if (G_LIKELY (acceptfunc)) {
2126 /* we can call the function */
2127 result = acceptfunc (pad, caps);
2129 /* Only null if the element explicitly unset it */
2130 result = gst_pad_acceptcaps_default (pad, caps);
2135 gst_caps_unref (existing);
2140 * gst_pad_peer_accept_caps:
2141 * @pad: a #GstPad to check
2142 * @caps: a #GstCaps to check on the pad
2144 * Check if the given pad accepts the caps.
2146 * Returns: TRUE if the pad can accept the caps.
2149 gst_pad_peer_accept_caps (GstPad * pad, GstCaps * caps)
2154 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2156 GST_OBJECT_LOCK (pad);
2158 GST_CAT_DEBUG (GST_CAT_CAPS, "peer accept caps of %s:%s (%p)",
2159 GST_DEBUG_PAD_NAME (pad), pad);
2161 peerpad = GST_PAD_PEER (pad);
2162 if (G_UNLIKELY (peerpad == NULL))
2165 result = gst_pad_accept_caps (peerpad, caps);
2166 GST_OBJECT_UNLOCK (pad);
2172 GST_OBJECT_UNLOCK (pad);
2179 * @pad: a #GstPad to set the capabilities of.
2180 * @caps: a #GstCaps to set.
2182 * Sets the capabilities of this pad. The caps must be fixed. Any previous
2183 * caps on the pad will be unreffed. This function refs the caps so you should
2184 * unref if as soon as you don't need it anymore.
2185 * It is possible to set NULL caps, which will make the pad unnegotiated
2188 * Returns: TRUE if the caps could be set. FALSE if the caps were not fixed
2189 * or bad parameters were provided to this function.
2194 gst_pad_set_caps (GstPad * pad, GstCaps * caps)
2196 GstPadSetCapsFunction setcaps;
2199 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2200 g_return_val_if_fail (caps == NULL || gst_caps_is_fixed (caps), FALSE);
2202 GST_OBJECT_LOCK (pad);
2203 setcaps = GST_PAD_SETCAPSFUNC (pad);
2205 existing = GST_PAD_CAPS (pad);
2206 if (gst_caps_is_equal (caps, existing))
2207 goto setting_same_caps;
2209 /* call setcaps function to configure the pad only if the
2210 * caps is not NULL */
2211 if (setcaps != NULL && caps) {
2212 if (!GST_PAD_IS_IN_SETCAPS (pad)) {
2213 GST_OBJECT_FLAG_SET (pad, GST_PAD_IN_SETCAPS);
2214 GST_OBJECT_UNLOCK (pad);
2215 if (!setcaps (pad, caps))
2217 GST_OBJECT_LOCK (pad);
2218 GST_OBJECT_FLAG_UNSET (pad, GST_PAD_IN_SETCAPS);
2220 GST_CAT_DEBUG (GST_CAT_CAPS, "pad %s:%s was dispatching",
2221 GST_DEBUG_PAD_NAME (pad));
2225 gst_caps_replace (&GST_PAD_CAPS (pad), caps);
2226 GST_CAT_DEBUG (GST_CAT_CAPS, "%s:%s caps %" GST_PTR_FORMAT,
2227 GST_DEBUG_PAD_NAME (pad), caps);
2228 GST_OBJECT_UNLOCK (pad);
2230 g_object_notify (G_OBJECT (pad), "caps");
2236 gst_caps_replace (&GST_PAD_CAPS (pad), caps);
2237 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
2238 "caps %" GST_PTR_FORMAT " same as existing, updating ptr only", caps);
2239 GST_OBJECT_UNLOCK (pad);
2246 GST_OBJECT_LOCK (pad);
2247 GST_OBJECT_FLAG_UNSET (pad, GST_PAD_IN_SETCAPS);
2248 GST_CAT_DEBUG (GST_CAT_CAPS,
2249 "pad %s:%s, caps %" GST_PTR_FORMAT " could not be set",
2250 GST_DEBUG_PAD_NAME (pad), caps);
2251 GST_OBJECT_UNLOCK (pad);
2258 gst_pad_configure_sink (GstPad * pad, GstCaps * caps)
2260 GstPadSetCapsFunction setcaps;
2263 setcaps = GST_PAD_SETCAPSFUNC (pad);
2265 /* See if pad accepts the caps - only needed if
2266 * no setcaps function */
2267 if (setcaps == NULL)
2268 if (!gst_pad_accept_caps (pad, caps))
2271 /* set caps on pad if call succeeds */
2272 res = gst_pad_set_caps (pad, caps);
2273 /* no need to unref the caps here, set_caps takes a ref and
2274 * our ref goes away when we leave this function. */
2280 GST_CAT_DEBUG (GST_CAT_CAPS, "caps %" GST_PTR_FORMAT " not accepted", caps);
2285 /* returns TRUE if the src pad could be configured to accept the given caps */
2287 gst_pad_configure_src (GstPad * pad, GstCaps * caps, gboolean dosetcaps)
2289 GstPadSetCapsFunction setcaps;
2292 setcaps = GST_PAD_SETCAPSFUNC (pad);
2294 /* See if pad accepts the caps - only needed if
2295 * no setcaps function */
2296 if (setcaps == NULL)
2297 if (!gst_pad_accept_caps (pad, caps))
2301 res = gst_pad_set_caps (pad, caps);
2309 GST_CAT_DEBUG (GST_CAT_CAPS, "caps %" GST_PTR_FORMAT " not accepted", caps);
2315 * gst_pad_get_pad_template_caps:
2316 * @pad: a #GstPad to get the template capabilities from.
2318 * Gets the capabilities for @pad's template.
2320 * Returns: the #GstCaps of this pad template. If you intend to keep a reference
2321 * on the caps, make a copy (see gst_caps_copy ()).
2324 gst_pad_get_pad_template_caps (GstPad * pad)
2326 static GstStaticCaps anycaps = GST_STATIC_CAPS ("ANY");
2328 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2330 if (GST_PAD_PAD_TEMPLATE (pad))
2331 return GST_PAD_TEMPLATE_CAPS (GST_PAD_PAD_TEMPLATE (pad));
2333 return gst_static_caps_get (&anycaps);
2339 * @pad: a #GstPad to get the peer of.
2341 * Gets the peer of @pad. This function refs the peer pad so
2342 * you need to unref it after use.
2344 * Returns: the peer #GstPad. Unref after usage.
2349 gst_pad_get_peer (GstPad * pad)
2353 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2355 GST_OBJECT_LOCK (pad);
2356 result = GST_PAD_PEER (pad);
2358 gst_object_ref (result);
2359 GST_OBJECT_UNLOCK (pad);
2365 * gst_pad_get_allowed_caps:
2366 * @srcpad: a #GstPad, it must a a source pad.
2368 * Gets the capabilities of the allowed media types that can flow through
2369 * @srcpad and its peer. The pad must be a source pad.
2370 * The caller must free the resulting caps.
2372 * Returns: the allowed #GstCaps of the pad link. Free the caps when
2373 * you no longer need it. This function returns NULL when the @srcpad has no
2379 gst_pad_get_allowed_caps (GstPad * srcpad)
2386 g_return_val_if_fail (GST_IS_PAD (srcpad), NULL);
2387 g_return_val_if_fail (GST_PAD_IS_SRC (srcpad), NULL);
2389 GST_OBJECT_LOCK (srcpad);
2391 peer = GST_PAD_PEER (srcpad);
2392 if (G_UNLIKELY (peer == NULL))
2395 GST_CAT_DEBUG (GST_CAT_PROPERTIES, "%s:%s: getting allowed caps",
2396 GST_DEBUG_PAD_NAME (srcpad));
2398 gst_object_ref (peer);
2399 GST_OBJECT_UNLOCK (srcpad);
2400 mycaps = gst_pad_get_caps (srcpad);
2402 peercaps = gst_pad_get_caps (peer);
2403 gst_object_unref (peer);
2405 caps = gst_caps_intersect (mycaps, peercaps);
2406 gst_caps_unref (peercaps);
2407 gst_caps_unref (mycaps);
2409 GST_CAT_DEBUG (GST_CAT_CAPS, "allowed caps %" GST_PTR_FORMAT, caps);
2415 GST_CAT_DEBUG (GST_CAT_PROPERTIES, "%s:%s: no peer",
2416 GST_DEBUG_PAD_NAME (srcpad));
2417 GST_OBJECT_UNLOCK (srcpad);
2424 * gst_pad_get_negotiated_caps:
2427 * Gets the capabilities of the media type that currently flows through @pad
2430 * This function can be used on both src and sinkpads. Note that srcpads are
2431 * always negotiated before sinkpads so it is possible that the negotiated caps
2432 * on the srcpad do not match the negotiated caps of the peer.
2434 * Returns: the negotiated #GstCaps of the pad link. Free the caps when
2435 * you no longer need it. This function returns NULL when the @pad has no
2436 * peer or is not negotiated yet.
2441 gst_pad_get_negotiated_caps (GstPad * pad)
2446 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2448 GST_OBJECT_LOCK (pad);
2450 if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
2453 GST_CAT_DEBUG (GST_CAT_PROPERTIES, "%s:%s: getting negotiated caps",
2454 GST_DEBUG_PAD_NAME (pad));
2456 caps = GST_PAD_CAPS (pad);
2458 gst_caps_ref (caps);
2459 GST_OBJECT_UNLOCK (pad);
2461 GST_CAT_DEBUG (GST_CAT_CAPS, "negotiated caps %" GST_PTR_FORMAT, caps);
2467 GST_CAT_DEBUG (GST_CAT_PROPERTIES, "%s:%s: no peer",
2468 GST_DEBUG_PAD_NAME (pad));
2469 GST_OBJECT_UNLOCK (pad);
2475 static GstFlowReturn
2476 gst_pad_alloc_buffer_full (GstPad * pad, guint64 offset, gint size,
2477 GstCaps * caps, GstBuffer ** buf, gboolean setcaps)
2481 GstPadBufferAllocFunction bufferallocfunc;
2482 gboolean caps_changed;
2484 g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
2485 g_return_val_if_fail (GST_PAD_IS_SRC (pad), GST_FLOW_ERROR);
2486 g_return_val_if_fail (buf != NULL, GST_FLOW_ERROR);
2488 GST_OBJECT_LOCK (pad);
2489 while (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad)))
2490 if ((ret = handle_pad_block (pad)) != GST_FLOW_OK)
2493 if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
2496 gst_object_ref (peer);
2497 GST_OBJECT_UNLOCK (pad);
2499 if (G_LIKELY ((bufferallocfunc = peer->bufferallocfunc) == NULL))
2502 GST_OBJECT_LOCK (peer);
2503 /* when the peer is flushing we cannot give a buffer */
2504 if (G_UNLIKELY (GST_PAD_IS_FLUSHING (peer)))
2507 if (offset == GST_BUFFER_OFFSET_NONE) {
2508 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
2509 "calling bufferallocfunc &%s (@%p) of peer pad %s:%s for size %d offset NONE",
2510 GST_DEBUG_FUNCPTR_NAME (bufferallocfunc),
2511 &bufferallocfunc, GST_DEBUG_PAD_NAME (peer), size);
2513 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
2514 "calling bufferallocfunc &%s (@%p) of peer pad %s:%s for size %d offset %"
2515 G_GUINT64_FORMAT, GST_DEBUG_FUNCPTR_NAME (bufferallocfunc),
2516 &bufferallocfunc, GST_DEBUG_PAD_NAME (peer), size, offset);
2518 GST_OBJECT_UNLOCK (peer);
2520 ret = bufferallocfunc (peer, offset, size, caps, buf);
2522 if (G_UNLIKELY (ret != GST_FLOW_OK))
2524 if (G_UNLIKELY (*buf == NULL))
2527 /* If the buffer alloc function didn't set up the caps like it should,
2529 if (caps && (GST_BUFFER_CAPS (*buf) == NULL)) {
2530 GST_WARNING ("Buffer allocation function for pad % " GST_PTR_FORMAT
2531 " did not set up caps. Setting", peer);
2533 gst_buffer_set_caps (*buf, caps);
2537 gst_object_unref (peer);
2539 /* FIXME, move capnego this into a base class? */
2540 caps = GST_BUFFER_CAPS (*buf);
2541 caps_changed = caps && caps != GST_PAD_CAPS (pad);
2542 /* we got a new datatype on the pad, see if it can handle it */
2543 if (G_UNLIKELY (caps_changed)) {
2544 GST_DEBUG_OBJECT (pad, "caps changed to %" GST_PTR_FORMAT, caps);
2545 if (G_UNLIKELY (!gst_pad_configure_src (pad, caps, setcaps)))
2546 goto not_negotiated;
2552 GST_CAT_DEBUG (GST_CAT_PADS, "%s:%s pad block stopped by flush",
2553 GST_DEBUG_PAD_NAME (pad));
2554 GST_OBJECT_UNLOCK (pad);
2559 /* pad has no peer */
2560 GST_CAT_DEBUG (GST_CAT_PADS,
2561 "%s:%s called bufferallocfunc but had no peer",
2562 GST_DEBUG_PAD_NAME (pad));
2563 GST_OBJECT_UNLOCK (pad);
2564 return GST_FLOW_NOT_LINKED;
2568 /* peer was flushing */
2569 GST_OBJECT_UNLOCK (peer);
2570 gst_object_unref (peer);
2571 GST_CAT_DEBUG (GST_CAT_PADS,
2572 "%s:%s called bufferallocfunc but peer was flushing",
2573 GST_DEBUG_PAD_NAME (pad));
2574 return GST_FLOW_WRONG_STATE;
2576 /* fallback case, allocate a buffer of our own, add pad caps. */
2579 GST_CAT_DEBUG (GST_CAT_PADS,
2580 "%s:%s fallback buffer alloc", GST_DEBUG_PAD_NAME (pad));
2581 *buf = gst_buffer_new_and_alloc (size);
2582 GST_BUFFER_OFFSET (*buf) = offset;
2583 gst_buffer_set_caps (*buf, caps);
2591 gst_buffer_unref (*buf);
2593 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
2594 "alloc function returned unacceptable buffer");
2595 return GST_FLOW_NOT_NEGOTIATED;
2599 gst_object_unref (peer);
2600 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
2601 "alloc function returned error %s", gst_flow_get_name (ret));
2607 * gst_pad_alloc_buffer:
2608 * @pad: a source #GstPad
2609 * @offset: the offset of the new buffer in the stream
2610 * @size: the size of the new buffer
2611 * @caps: the caps of the new buffer
2612 * @buf: a newly allocated buffer
2614 * Allocates a new, empty buffer optimized to push to pad @pad. This
2615 * function only works if @pad is a source pad and has a peer.
2617 * You need to check the caps of the buffer after performing this
2618 * function and renegotiate to the format if needed.
2620 * A new, empty #GstBuffer will be put in the @buf argument.
2622 * Returns: a result code indicating success of the operation. Any
2623 * result code other than GST_FLOW_OK is an error and @buf should
2625 * An error can occur if the pad is not connected or when the downstream
2626 * peer elements cannot provide an acceptable buffer.
2631 gst_pad_alloc_buffer (GstPad * pad, guint64 offset, gint size, GstCaps * caps,
2634 return gst_pad_alloc_buffer_full (pad, offset, size, caps, buf, FALSE);
2638 * gst_pad_alloc_buffer_and_set_caps:
2639 * @pad: a source #GstPad
2640 * @offset: the offset of the new buffer in the stream
2641 * @size: the size of the new buffer
2642 * @caps: the caps of the new buffer
2643 * @buf: a newly allocated buffer
2645 * In addition to the function gst_pad_alloc_buffer(), this function
2646 * automatically calls gst_pad_set_caps() when the caps of the
2647 * newly allocated buffer are different from the @pad caps.
2649 * Returns: a result code indicating success of the operation. Any
2650 * result code other than GST_FLOW_OK is an error and @buf should
2652 * An error can occur if the pad is not connected or when the downstream
2653 * peer elements cannot provide an acceptable buffer.
2658 gst_pad_alloc_buffer_and_set_caps (GstPad * pad, guint64 offset, gint size,
2659 GstCaps * caps, GstBuffer ** buf)
2661 return gst_pad_alloc_buffer_full (pad, offset, size, caps, buf, TRUE);
2665 * gst_pad_get_internal_links_default:
2666 * @pad: the #GstPad to get the internal links of.
2668 * Gets a list of pads to which the given pad is linked to
2669 * inside of the parent element.
2670 * This is the default handler, and thus returns a list of all of the
2671 * pads inside the parent element with opposite direction.
2672 * The caller must free this list after use.
2674 * Returns: a newly allocated #GList of pads, or NULL if the pad has no parent.
2679 gst_pad_get_internal_links_default (GstPad * pad)
2684 GstPadDirection direction;
2686 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2688 direction = pad->direction;
2690 parent = GST_PAD_PARENT (pad);
2694 parent_pads = parent->pads;
2696 while (parent_pads) {
2697 GstPad *parent_pad = GST_PAD_CAST (parent_pads->data);
2699 if (parent_pad->direction != direction) {
2700 res = g_list_prepend (res, parent_pad);
2703 parent_pads = g_list_next (parent_pads);
2710 * gst_pad_get_internal_links:
2711 * @pad: the #GstPad to get the internal links of.
2713 * Gets a list of pads to which the given pad is linked to
2714 * inside of the parent element.
2715 * The caller must free this list after use.
2717 * Returns: a newly allocated #GList of pads.
2722 gst_pad_get_internal_links (GstPad * pad)
2726 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2728 if (GST_PAD_INTLINKFUNC (pad))
2729 res = GST_PAD_INTLINKFUNC (pad) (pad);
2736 gst_pad_event_default_dispatch (GstPad * pad, GstEvent * event)
2741 GST_INFO_OBJECT (pad, "Sending event %p to all internally linked pads",
2744 result = (GST_PAD_DIRECTION (pad) == GST_PAD_SINK);
2746 orig = pads = gst_pad_get_internal_links (pad);
2749 GstPad *eventpad = GST_PAD_CAST (pads->data);
2751 pads = g_list_next (pads);
2753 if (GST_PAD_DIRECTION (eventpad) == GST_PAD_SRC) {
2754 /* for each pad we send to, we should ref the event; it's up
2755 * to downstream to unref again when handled. */
2756 GST_LOG_OBJECT (pad, "Reffing and sending event %p (%s) to %s:%s",
2757 event, GST_EVENT_TYPE_NAME (event), GST_DEBUG_PAD_NAME (eventpad));
2758 gst_event_ref (event);
2759 gst_pad_push_event (eventpad, event);
2761 /* we only send the event on one pad, multi-sinkpad elements
2762 * should implement a handler */
2763 GST_LOG_OBJECT (pad, "sending event %p (%s) to one sink pad %s:%s",
2764 event, GST_EVENT_TYPE_NAME (event), GST_DEBUG_PAD_NAME (eventpad));
2765 result = gst_pad_push_event (eventpad, event);
2769 /* we handled the incoming event so we unref once */
2770 GST_LOG_OBJECT (pad, "handled event %p, unreffing", event);
2771 gst_event_unref (event);
2780 * gst_pad_event_default:
2781 * @pad: a #GstPad to call the default event handler on.
2782 * @event: the #GstEvent to handle.
2784 * Invokes the default event handler for the given pad. End-of-stream and
2785 * discontinuity events are handled specially, and then the event is sent to all
2786 * pads internally linked to @pad. Note that if there are many possible sink
2787 * pads that are internally linked to @pad, only one will be sent an event.
2788 * Multi-sinkpad elements should implement custom event handlers.
2790 * Returns: TRUE if the event was sent succesfully.
2793 gst_pad_event_default (GstPad * pad, GstEvent * event)
2795 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2796 g_return_val_if_fail (event != NULL, FALSE);
2798 switch (GST_EVENT_TYPE (event)) {
2801 GST_DEBUG_OBJECT (pad, "pausing task because of eos");
2802 gst_pad_pause_task (pad);
2808 return gst_pad_event_default_dispatch (pad, event);
2812 * gst_pad_dispatcher:
2813 * @pad: a #GstPad to dispatch.
2814 * @dispatch: the #GstDispatcherFunction to call.
2815 * @data: gpointer user data passed to the dispatcher function.
2817 * Invokes the given dispatcher function on all pads that are
2818 * internally linked to the given pad.
2819 * The GstPadDispatcherFunction should return TRUE when no further pads
2820 * need to be processed.
2822 * Returns: TRUE if one of the dispatcher functions returned TRUE.
2825 gst_pad_dispatcher (GstPad * pad, GstPadDispatcherFunction dispatch,
2828 gboolean res = FALSE;
2829 GList *int_pads, *orig;
2831 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2832 g_return_val_if_fail (dispatch != NULL, FALSE);
2834 orig = int_pads = gst_pad_get_internal_links (pad);
2837 GstPad *int_pad = GST_PAD_CAST (int_pads->data);
2838 GstPad *int_peer = GST_PAD_PEER (int_pad);
2841 res = dispatch (int_peer, data);
2845 int_pads = g_list_next (int_pads);
2855 * @pad: a #GstPad to invoke the default query on.
2856 * @query: the #GstQuery to perform.
2858 * Dispatches a query to a pad. The query should have been allocated by the
2859 * caller via one of the type-specific allocation functions in gstquery.h. The
2860 * element is responsible for filling the query with an appropriate response,
2861 * which should then be parsed with a type-specific query parsing function.
2863 * Again, the caller is responsible for both the allocation and deallocation of
2864 * the query structure.
2866 * Returns: TRUE if the query could be performed.
2869 gst_pad_query (GstPad * pad, GstQuery * query)
2871 GstPadQueryFunction func;
2873 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2874 g_return_val_if_fail (GST_IS_QUERY (query), FALSE);
2876 GST_DEBUG ("sending query %p to pad %s:%s", query, GST_DEBUG_PAD_NAME (pad));
2878 if ((func = GST_PAD_QUERYFUNC (pad)) == NULL)
2881 return func (pad, query);
2885 GST_DEBUG ("pad had no query function");
2891 * gst_pad_query_default:
2892 * @pad: a #GstPad to call the default query handler on.
2893 * @query: the #GstQuery to handle.
2895 * Invokes the default query handler for the given pad.
2896 * The query is sent to all pads internally linked to @pad. Note that
2897 * if there are many possible sink pads that are internally linked to
2898 * @pad, only one will be sent the query.
2899 * Multi-sinkpad elements should implement custom query handlers.
2901 * Returns: TRUE if the query was performed succesfully.
2904 gst_pad_query_default (GstPad * pad, GstQuery * query)
2906 switch (GST_QUERY_TYPE (query)) {
2907 case GST_QUERY_POSITION:
2908 case GST_QUERY_SEEKING:
2909 case GST_QUERY_FORMATS:
2910 case GST_QUERY_LATENCY:
2911 case GST_QUERY_JITTER:
2912 case GST_QUERY_RATE:
2913 case GST_QUERY_CONVERT:
2915 return gst_pad_dispatcher
2916 (pad, (GstPadDispatcherFunction) gst_pad_query, query);
2920 #ifndef GST_DISABLE_LOADSAVE
2921 /* FIXME: why isn't this on a GstElement ? */
2923 * gst_pad_load_and_link:
2924 * @self: an #xmlNodePtr to read the description from.
2925 * @parent: the #GstObject element that owns the pad.
2927 * Reads the pad definition from the XML node and links the given pad
2928 * in the element to a pad of an element up in the hierarchy.
2931 gst_pad_load_and_link (xmlNodePtr self, GstObject * parent)
2933 xmlNodePtr field = self->xmlChildrenNode;
2934 GstPad *pad = NULL, *targetpad;
2938 GstObject *grandparent;
2942 if (!strcmp ((char *) field->name, "name")) {
2943 name = (gchar *) xmlNodeGetContent (field);
2944 pad = gst_element_get_pad (GST_ELEMENT (parent), name);
2946 } else if (!strcmp ((char *) field->name, "peer")) {
2947 peer = (gchar *) xmlNodeGetContent (field);
2949 field = field->next;
2951 g_return_if_fail (pad != NULL);
2956 split = g_strsplit (peer, ".", 2);
2958 if (split[0] == NULL || split[1] == NULL) {
2959 GST_CAT_DEBUG (GST_CAT_XML,
2960 "Could not parse peer '%s' for pad %s:%s, leaving unlinked",
2961 peer, GST_DEBUG_PAD_NAME (pad));
2968 g_return_if_fail (split[0] != NULL);
2969 g_return_if_fail (split[1] != NULL);
2971 grandparent = gst_object_get_parent (parent);
2973 if (grandparent && GST_IS_BIN (grandparent)) {
2974 target = gst_bin_get_by_name_recurse_up (GST_BIN (grandparent), split[0]);
2981 targetpad = gst_element_get_pad (target, split[1]);
2983 if (targetpad == NULL)
2986 gst_pad_link (pad, targetpad);
2993 * gst_pad_save_thyself:
2994 * @pad: a #GstPad to save.
2995 * @parent: the parent #xmlNodePtr to save the description in.
2997 * Saves the pad into an xml representation.
2999 * Returns: the #xmlNodePtr representation of the pad.
3002 gst_pad_save_thyself (GstObject * object, xmlNodePtr parent)
3007 g_return_val_if_fail (GST_IS_PAD (object), NULL);
3009 pad = GST_PAD (object);
3011 xmlNewChild (parent, NULL, (xmlChar *) "name",
3012 (xmlChar *) GST_PAD_NAME (pad));
3013 if (GST_PAD_PEER (pad) != NULL) {
3016 peer = GST_PAD_PEER (pad);
3017 /* first check to see if the peer's parent's parent is the same */
3018 /* we just save it off */
3019 content = g_strdup_printf ("%s.%s",
3020 GST_OBJECT_NAME (GST_PAD_PARENT (peer)), GST_PAD_NAME (peer));
3021 xmlNewChild (parent, NULL, (xmlChar *) "peer", (xmlChar *) content);
3024 xmlNewChild (parent, NULL, (xmlChar *) "peer", NULL);
3031 * gst_ghost_pad_save_thyself:
3032 * @pad: a ghost #GstPad to save.
3033 * @parent: the parent #xmlNodePtr to save the description in.
3035 * Saves the ghost pad into an xml representation.
3037 * Returns: the #xmlNodePtr representation of the pad.
3040 gst_ghost_pad_save_thyself (GstPad * pad, xmlNodePtr parent)
3044 g_return_val_if_fail (GST_IS_GHOST_PAD (pad), NULL);
3046 self = xmlNewChild (parent, NULL, (xmlChar *) "ghostpad", NULL);
3047 xmlNewChild (self, NULL, (xmlChar *) "name", (xmlChar *) GST_PAD_NAME (pad));
3048 xmlNewChild (self, NULL, (xmlChar *) "parent",
3049 (xmlChar *) GST_OBJECT_NAME (GST_PAD_PARENT (pad)));
3051 /* FIXME FIXME FIXME! */
3056 #endif /* GST_DISABLE_LOADSAVE */
3059 * should be called with pad lock held
3063 static GstFlowReturn
3064 handle_pad_block (GstPad * pad)
3066 GstPadBlockCallback callback;
3068 GstFlowReturn ret = GST_FLOW_OK;
3070 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3071 "signal block taken on pad %s:%s", GST_DEBUG_PAD_NAME (pad));
3073 /* need to grab extra ref for the callbacks */
3074 gst_object_ref (pad);
3076 callback = pad->block_callback;
3078 user_data = pad->block_data;
3079 GST_OBJECT_UNLOCK (pad);
3080 callback (pad, TRUE, user_data);
3081 GST_OBJECT_LOCK (pad);
3083 GST_PAD_BLOCK_SIGNAL (pad);
3086 while (GST_PAD_IS_BLOCKED (pad)) {
3087 if (GST_PAD_IS_FLUSHING (pad))
3089 GST_PAD_BLOCK_WAIT (pad);
3090 if (GST_PAD_IS_FLUSHING (pad))
3094 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "got unblocked");
3096 callback = pad->block_callback;
3098 user_data = pad->block_data;
3099 GST_OBJECT_UNLOCK (pad);
3100 callback (pad, FALSE, user_data);
3101 GST_OBJECT_LOCK (pad);
3103 GST_PAD_BLOCK_SIGNAL (pad);
3106 gst_object_unref (pad);
3112 gst_object_unref (pad);
3113 return GST_FLOW_WRONG_STATE;
3117 /**********************************************************************
3118 * Data passing functions
3122 gst_pad_emit_have_data_signal (GstPad * pad, GstMiniObject * obj)
3125 GValue args[2] = { {0}, {0} };
3130 g_value_init (&ret, G_TYPE_BOOLEAN);
3131 g_value_set_boolean (&ret, TRUE);
3132 g_value_init (&args[0], GST_TYPE_PAD);
3133 g_value_set_object (&args[0], pad);
3134 g_value_init (&args[1], GST_TYPE_MINI_OBJECT); // G_TYPE_POINTER);
3135 gst_value_set_mini_object (&args[1], obj);
3137 if (GST_IS_EVENT (obj))
3138 detail = event_quark;
3140 detail = buffer_quark;
3143 g_signal_emitv (args, gst_pad_signals[PAD_HAVE_DATA], detail, &ret);
3144 res = g_value_get_boolean (&ret);
3147 g_value_unset (&ret);
3148 g_value_unset (&args[0]);
3149 g_value_unset (&args[1]);
3156 * @pad: a sink #GstPad.
3157 * @buffer: the #GstBuffer to send.
3159 * Chain a buffer to @pad.
3161 * Returns: a #GstFlowReturn from the pad.
3166 gst_pad_chain (GstPad * pad, GstBuffer * buffer)
3169 gboolean caps_changed;
3170 GstPadChainFunction chainfunc;
3172 gboolean emit_signal;
3174 g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
3175 g_return_val_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SINK,
3177 g_return_val_if_fail (buffer != NULL, GST_FLOW_ERROR);
3178 g_return_val_if_fail (GST_IS_BUFFER (buffer), GST_FLOW_ERROR);
3180 GST_PAD_STREAM_LOCK (pad);
3182 GST_OBJECT_LOCK (pad);
3183 if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad)))
3186 caps = GST_BUFFER_CAPS (buffer);
3187 caps_changed = caps && caps != GST_PAD_CAPS (pad);
3189 emit_signal = GST_PAD_DO_BUFFER_SIGNALS (pad) > 0;
3190 GST_OBJECT_UNLOCK (pad);
3192 /* see if the signal should be emited, we emit before caps nego as
3193 * we might drop the buffer and do capsnego for nothing. */
3194 if (G_UNLIKELY (emit_signal)) {
3195 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (buffer)))
3199 /* we got a new datatype on the pad, see if it can handle it */
3200 if (G_UNLIKELY (caps_changed)) {
3201 GST_DEBUG_OBJECT (pad, "caps changed to %" GST_PTR_FORMAT, caps);
3202 if (G_UNLIKELY (!gst_pad_configure_sink (pad, caps)))
3203 goto not_negotiated;
3206 /* NOTE: we read the chainfunc unlocked.
3207 * we cannot hold the lock for the pad so we might send
3208 * the data to the wrong function. This is not really a
3209 * problem since functions are assigned at creation time
3210 * and don't change that often... */
3211 if (G_UNLIKELY ((chainfunc = GST_PAD_CHAINFUNC (pad)) == NULL))
3214 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3215 "calling chainfunction &%s of pad %s:%s",
3216 GST_DEBUG_FUNCPTR_NAME (chainfunc), GST_DEBUG_PAD_NAME (pad));
3218 ret = chainfunc (pad, buffer);
3220 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3221 "called chainfunction &%s of pad %s:%s, returned %s",
3222 GST_DEBUG_FUNCPTR_NAME (chainfunc), GST_DEBUG_PAD_NAME (pad),
3223 gst_flow_get_name (ret));
3225 GST_PAD_STREAM_UNLOCK (pad);
3232 gst_buffer_unref (buffer);
3233 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3234 "pushing, but pad was flushing");
3235 GST_OBJECT_UNLOCK (pad);
3236 GST_PAD_STREAM_UNLOCK (pad);
3237 return GST_FLOW_WRONG_STATE;
3241 gst_buffer_unref (buffer);
3242 GST_DEBUG_OBJECT (pad, "Dropping buffer due to FALSE probe return");
3243 GST_PAD_STREAM_UNLOCK (pad);
3248 gst_buffer_unref (buffer);
3249 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3250 "pushing buffer but pad did not accept");
3251 GST_PAD_STREAM_UNLOCK (pad);
3252 return GST_FLOW_NOT_NEGOTIATED;
3256 gst_buffer_unref (buffer);
3257 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3258 "pushing, but not chainhandler");
3259 GST_ELEMENT_ERROR (GST_PAD_PARENT (pad), CORE, PAD, (NULL),
3260 ("push on pad %s:%s but it has no chainfunction",
3261 GST_DEBUG_PAD_NAME (pad)));
3262 GST_PAD_STREAM_UNLOCK (pad);
3263 return GST_FLOW_ERROR;
3269 * @pad: a source #GstPad.
3270 * @buffer: the #GstBuffer to push.
3272 * Pushes a buffer to the peer of @pad.
3273 * buffer probes will be triggered before the buffer gets pushed.
3275 * Returns: a #GstFlowReturn from the peer pad.
3280 gst_pad_push (GstPad * pad, GstBuffer * buffer)
3285 gboolean caps_changed;
3287 g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
3288 g_return_val_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SRC, GST_FLOW_ERROR);
3289 g_return_val_if_fail (buffer != NULL, GST_FLOW_ERROR);
3290 g_return_val_if_fail (GST_IS_BUFFER (buffer), GST_FLOW_ERROR);
3292 GST_OBJECT_LOCK (pad);
3294 /* FIXME: this check can go away; pad_set_blocked could be implemented with
3295 * probes completely */
3296 while (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad)))
3297 if ((ret = handle_pad_block (pad)) != GST_FLOW_OK)
3300 /* we emit signals on the pad arg, the peer will have a chance to
3301 * emit in the _chain() function */
3302 if (G_UNLIKELY (GST_PAD_DO_BUFFER_SIGNALS (pad) > 0)) {
3303 /* unlock before emitting */
3304 GST_OBJECT_UNLOCK (pad);
3306 /* if the signal handler returned FALSE, it means we should just drop the
3308 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (buffer)))
3311 GST_OBJECT_LOCK (pad);
3314 if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
3316 gst_object_ref (peer);
3318 /* Before pushing the buffer to the peer pad, ensure that caps
3319 * are set on this pad */
3320 caps = GST_BUFFER_CAPS (buffer);
3321 caps_changed = caps && caps != GST_PAD_CAPS (pad);
3323 GST_OBJECT_UNLOCK (pad);
3325 /* we got a new datatype from the pad, it had better handle it */
3326 if (G_UNLIKELY (caps_changed)) {
3327 GST_DEBUG_OBJECT (pad, "caps changed to %" GST_PTR_FORMAT, caps);
3328 if (G_UNLIKELY (!gst_pad_configure_src (pad, caps, TRUE)))
3329 goto not_negotiated;
3332 ret = gst_pad_chain (peer, buffer);
3334 gst_object_unref (peer);
3338 /* ERROR recovery here */
3341 gst_buffer_unref (buffer);
3342 GST_DEBUG_OBJECT (pad, "pad block stopped by flush");
3343 GST_OBJECT_UNLOCK (pad);
3348 gst_buffer_unref (buffer);
3349 GST_DEBUG_OBJECT (pad, "Dropping buffer due to FALSE probe return");
3354 gst_buffer_unref (buffer);
3355 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3356 "pushing, but it was not linked");
3357 GST_OBJECT_UNLOCK (pad);
3358 return GST_FLOW_NOT_LINKED;
3362 gst_buffer_unref (buffer);
3363 gst_object_unref (peer);
3364 GST_CAT_DEBUG_OBJECT (GST_CAT_SCHEDULING, pad,
3365 "element pushed buffer then refused to accept the caps");
3366 return GST_FLOW_NOT_NEGOTIATED;
3371 * gst_pad_check_pull_range:
3372 * @pad: a sink #GstPad.
3374 * Checks if a gst_pad_pull_range() can be performed on the peer
3375 * source pad. This function is used by plugins that want to check
3376 * if they can use random access on the peer source pad.
3378 * The peer sourcepad can implement a custom #GstPadCheckGetRangeFunction
3379 * if it needs to perform some logic to determine if pull_range is
3382 * Returns: a gboolean with the result.
3387 gst_pad_check_pull_range (GstPad * pad)
3391 GstPadCheckGetRangeFunction checkgetrangefunc;
3393 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
3395 GST_OBJECT_LOCK (pad);
3396 if (GST_PAD_DIRECTION (pad) != GST_PAD_SINK)
3397 goto wrong_direction;
3399 if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
3402 gst_object_ref (peer);
3403 GST_OBJECT_UNLOCK (pad);
3405 /* see note in above function */
3406 if (G_LIKELY ((checkgetrangefunc = peer->checkgetrangefunc) == NULL)) {
3407 /* FIXME, kindoff ghetto */
3408 ret = GST_PAD_GETRANGEFUNC (peer) != NULL;
3410 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3411 "calling checkgetrangefunc %s of peer pad %s:%s",
3412 GST_DEBUG_FUNCPTR_NAME (checkgetrangefunc), GST_DEBUG_PAD_NAME (peer));
3414 ret = checkgetrangefunc (peer);
3417 gst_object_unref (peer);
3421 /* ERROR recovery here */
3424 GST_OBJECT_UNLOCK (pad);
3429 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3430 "checking pull range, but it was not linked");
3431 GST_OBJECT_UNLOCK (pad);
3437 * gst_pad_get_range:
3438 * @pad: a src #GstPad.
3439 * @offset: The start offset of the buffer
3440 * @size: The length of the buffer
3441 * @buffer: a pointer to hold the #GstBuffer.
3443 * Calls the getrange function of @pad.
3445 * Returns: a #GstFlowReturn from the pad.
3450 gst_pad_get_range (GstPad * pad, guint64 offset, guint size,
3451 GstBuffer ** buffer)
3454 GstPadGetRangeFunction getrangefunc;
3455 gboolean emit_signal;
3457 g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
3458 g_return_val_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SRC, GST_FLOW_ERROR);
3459 g_return_val_if_fail (buffer != NULL, GST_FLOW_ERROR);
3461 GST_PAD_STREAM_LOCK (pad);
3463 GST_OBJECT_LOCK (pad);
3464 if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad)))
3467 emit_signal = GST_PAD_DO_BUFFER_SIGNALS (pad) > 0;
3468 GST_OBJECT_UNLOCK (pad);
3470 if (G_UNLIKELY ((getrangefunc = GST_PAD_GETRANGEFUNC (pad)) == NULL))
3473 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3474 "calling getrangefunc %s of peer pad %s:%s, offset %"
3475 G_GUINT64_FORMAT ", size %u",
3476 GST_DEBUG_FUNCPTR_NAME (getrangefunc), GST_DEBUG_PAD_NAME (pad),
3479 ret = getrangefunc (pad, offset, size, buffer);
3481 /* can only fire the signal if we have a valid buffer */
3482 if (G_UNLIKELY (emit_signal) && (ret == GST_FLOW_OK)) {
3483 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (*buffer)))
3487 GST_PAD_STREAM_UNLOCK (pad);
3494 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3495 "pulling range, but pad was flushing");
3496 GST_OBJECT_UNLOCK (pad);
3497 GST_PAD_STREAM_UNLOCK (pad);
3498 return GST_FLOW_WRONG_STATE;
3502 GST_ELEMENT_ERROR (GST_PAD_PARENT (pad), CORE, PAD, (NULL),
3503 ("pullrange on pad %s:%s but it has no getrangefunction",
3504 GST_DEBUG_PAD_NAME (pad)));
3505 GST_PAD_STREAM_UNLOCK (pad);
3506 return GST_FLOW_ERROR;
3510 GST_DEBUG ("Dropping data after FALSE probe return");
3511 GST_PAD_STREAM_UNLOCK (pad);
3512 gst_buffer_unref (*buffer);
3514 return GST_FLOW_UNEXPECTED;
3520 * gst_pad_pull_range:
3521 * @pad: a sink #GstPad.
3522 * @offset: The start offset of the buffer
3523 * @size: The length of the buffer
3524 * @buffer: a pointer to hold the #GstBuffer.
3526 * Pulls a buffer from the peer pad. @pad must be a linked
3529 * Returns: a #GstFlowReturn from the peer pad.
3534 gst_pad_pull_range (GstPad * pad, guint64 offset, guint size,
3535 GstBuffer ** buffer)
3539 gboolean emit_signal;
3541 g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
3542 g_return_val_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SINK,
3544 g_return_val_if_fail (buffer != NULL, GST_FLOW_ERROR);
3546 GST_OBJECT_LOCK (pad);
3548 while (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad)))
3549 handle_pad_block (pad);
3551 if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
3554 /* signal emision for the pad, peer has chance to emit when
3555 * we call _get_range() */
3556 emit_signal = GST_PAD_DO_BUFFER_SIGNALS (pad) > 0;
3558 gst_object_ref (peer);
3559 GST_OBJECT_UNLOCK (pad);
3561 ret = gst_pad_get_range (peer, offset, size, buffer);
3563 gst_object_unref (peer);
3565 /* can only fire the signal if we have a valid buffer */
3566 if (G_UNLIKELY (emit_signal) && (ret == GST_FLOW_OK)) {
3567 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (*buffer)))
3572 /* ERROR recovery here */
3575 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3576 "pulling range, but it was not linked");
3577 GST_OBJECT_UNLOCK (pad);
3578 return GST_FLOW_NOT_LINKED;
3582 GST_DEBUG ("Dropping data after FALSE probe return");
3583 gst_buffer_unref (*buffer);
3585 return GST_FLOW_UNEXPECTED;
3590 * gst_pad_push_event:
3591 * @pad: a #GstPad to push the event to.
3592 * @event: the #GstEvent to send to the pad.
3594 * Sends the event to the peer of the given pad. This function is
3595 * mainly used by elements to send events to their peer
3598 * This function takes owership of the provided event so you should
3599 * gst_event_ref() it if you want to reuse the event after this call.
3601 * Returns: TRUE if the event was handled.
3606 gst_pad_push_event (GstPad * pad, GstEvent * event)
3611 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
3612 g_return_val_if_fail (event != NULL, FALSE);
3613 g_return_val_if_fail (GST_IS_EVENT (event), FALSE);
3615 GST_OBJECT_LOCK (pad);
3616 switch (GST_EVENT_TYPE (event)) {
3617 case GST_EVENT_FLUSH_START:
3618 GST_PAD_SET_FLUSHING (pad);
3620 case GST_EVENT_FLUSH_STOP:
3621 GST_PAD_UNSET_FLUSHING (pad);
3627 if (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad))) {
3628 if (GST_EVENT_TYPE (event) == GST_EVENT_FLUSH_START) {
3629 GST_PAD_BLOCK_SIGNAL (pad);
3633 if (G_UNLIKELY (GST_PAD_DO_EVENT_SIGNALS (pad) > 0)) {
3634 GST_OBJECT_UNLOCK (pad);
3636 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (event)))
3639 GST_OBJECT_LOCK (pad);
3641 peerpad = GST_PAD_PEER (pad);
3642 if (peerpad == NULL)
3645 GST_LOG_OBJECT (peerpad, "sending event on peerpad");
3646 gst_object_ref (peerpad);
3647 GST_OBJECT_UNLOCK (pad);
3649 result = gst_pad_send_event (peerpad, event);
3651 gst_object_unref (peerpad);
3652 GST_LOG_OBJECT (peerpad, "sent event on peerpad");
3656 /* ERROR handling */
3659 GST_DEBUG_OBJECT (pad, "Dropping event after FALSE probe return");
3660 gst_event_unref (event);
3665 gst_event_unref (event);
3666 GST_OBJECT_UNLOCK (pad);
3672 * gst_pad_send_event:
3673 * @pad: a #GstPad to send the event to.
3674 * @event: the #GstEvent to send to the pad.
3676 * Sends the event to the pad. This function can be used
3677 * by applications to send events in the pipeline.
3679 * If @pad is a source pad, @event should be an upstream event. If @pad is a
3680 * sink pad, @event should be a downstream event. For example, you would not
3681 * send a #GST_EVENT_EOS on a src pad; EOS events only propagate downstream.
3682 * Furthermore, some downstream events have to be serialized with data flow,
3683 * like EOS, while some can travel out-of-band, like #GST_EVENT_FLUSH_START. If
3684 * the event needs to be serialized with data flow, this function will take the
3685 * pad's stream lock while calling its event function.
3687 * To find out whether an event type is upstream, downstream, or downstream and
3688 * serialized, see #GstEventTypeFlags, gst_event_type_get_flags(),
3689 * #GST_EVENT_IS_UPSTREAM, #GST_EVENT_IS_DOWNSTREAM, and
3690 * #GST_EVENT_IS_SERIALIZED. Note that in practice that an application or plugin
3691 * doesn't need to bother itself with this information; the core handles all
3692 * necessary locks and checks.
3694 * This function takes owership of the provided event so you should
3695 * gst_event_ref() it if you want to reuse the event after this call.
3697 * Returns: TRUE if the event was handled.
3700 gst_pad_send_event (GstPad * pad, GstEvent * event)
3702 gboolean result = FALSE;
3703 GstPadEventFunction eventfunc;
3704 gboolean serialized, need_unlock = FALSE;
3706 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
3707 g_return_val_if_fail (event != NULL, FALSE);
3709 GST_OBJECT_LOCK (pad);
3710 if (GST_PAD_IS_SINK (pad)) {
3711 if (G_UNLIKELY (!GST_EVENT_IS_DOWNSTREAM (event)))
3712 goto wrong_direction;
3713 serialized = GST_EVENT_IS_SERIALIZED (event);
3714 } else if (GST_PAD_IS_SRC (pad)) {
3715 if (G_UNLIKELY (!GST_EVENT_IS_UPSTREAM (event)))
3716 goto wrong_direction;
3717 /* events on srcpad never are serialized */
3720 goto unknown_direction;
3722 if (G_UNLIKELY (GST_EVENT_SRC (event) == NULL)) {
3723 GST_LOG_OBJECT (pad, "event had no source, setting pad as event source");
3724 GST_EVENT_SRC (event) = gst_object_ref (pad);
3728 if (G_UNLIKELY (GST_PAD_DO_EVENT_SIGNALS (pad) > 0)) {
3729 GST_OBJECT_UNLOCK (pad);
3731 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT_CAST (event)))
3734 GST_OBJECT_LOCK (pad);
3737 switch (GST_EVENT_TYPE (event)) {
3738 case GST_EVENT_FLUSH_START:
3739 GST_CAT_DEBUG (GST_CAT_EVENT,
3740 "have event type %d (FLUSH_START) on pad %s:%s",
3741 GST_EVENT_TYPE (event), GST_DEBUG_PAD_NAME (pad));
3743 /* can't even accept a flush begin event when flushing */
3744 if (GST_PAD_IS_FLUSHING (pad))
3746 GST_PAD_SET_FLUSHING (pad);
3747 GST_CAT_DEBUG (GST_CAT_EVENT, "set flush flag");
3749 case GST_EVENT_FLUSH_STOP:
3750 GST_PAD_UNSET_FLUSHING (pad);
3751 GST_CAT_DEBUG (GST_CAT_EVENT, "cleared flush flag");
3752 GST_OBJECT_UNLOCK (pad);
3753 /* grab stream lock */
3754 GST_PAD_STREAM_LOCK (pad);
3756 GST_OBJECT_LOCK (pad);
3759 GST_CAT_DEBUG (GST_CAT_EVENT, "have event type %s on pad %s:%s",
3760 GST_EVENT_TYPE_NAME (event), GST_DEBUG_PAD_NAME (pad));
3762 /* make this a little faster, no point in grabbing the lock
3763 * if the pad is allready flushing. */
3764 if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad)))
3768 /* lock order: STREAM_LOCK, LOCK */
3769 GST_OBJECT_UNLOCK (pad);
3770 GST_PAD_STREAM_LOCK (pad);
3772 GST_OBJECT_LOCK (pad);
3773 if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad)))
3778 if (G_UNLIKELY ((eventfunc = GST_PAD_EVENTFUNC (pad)) == NULL))
3781 GST_OBJECT_UNLOCK (pad);
3783 result = eventfunc (pad, event);
3786 GST_PAD_STREAM_UNLOCK (pad);
3790 /* ERROR handling */
3793 g_warning ("pad %s:%s sending %s event in wrong direction",
3794 GST_DEBUG_PAD_NAME (pad), GST_EVENT_TYPE_NAME (event));
3795 GST_OBJECT_UNLOCK (pad);
3796 gst_event_unref (event);
3801 g_warning ("pad %s:%s has invalid direction", GST_DEBUG_PAD_NAME (pad));
3802 GST_OBJECT_UNLOCK (pad);
3803 gst_event_unref (event);
3808 g_warning ("pad %s:%s has no event handler, file a bug.",
3809 GST_DEBUG_PAD_NAME (pad));
3810 GST_OBJECT_UNLOCK (pad);
3811 gst_event_unref (event);
3816 GST_OBJECT_UNLOCK (pad);
3818 GST_PAD_STREAM_UNLOCK (pad);
3819 GST_CAT_INFO (GST_CAT_EVENT, "Received event on flushing pad. Discarding");
3820 gst_event_unref (event);
3825 GST_DEBUG ("Dropping event after FALSE probe return");
3826 gst_event_unref (event);
3832 * gst_pad_set_element_private:
3833 * @pad: the #GstPad to set the private data of.
3834 * @priv: The private data to attach to the pad.
3836 * Set the given private data gpointer on the pad.
3837 * This function can only be used by the element that owns the pad.
3838 * No locking is performed in this function.
3841 gst_pad_set_element_private (GstPad * pad, gpointer priv)
3843 pad->element_private = priv;
3847 * gst_pad_get_element_private:
3848 * @pad: the #GstPad to get the private data of.
3850 * Gets the private data of a pad.
3851 * No locking is performed in this function.
3853 * Returns: a #gpointer to the private data.
3856 gst_pad_get_element_private (GstPad * pad)
3858 return pad->element_private;
3862 * gst_pad_start_task:
3863 * @pad: the #GstPad to start the task of
3864 * @func: the task function to call
3865 * @data: data passed to the task function
3867 * Starts a task that repeadedly calls @func with @data. This function
3868 * is nostly used in the pad activation function to start the
3869 * dataflow. This function will automatically acquire the STREAM_LOCK of
3870 * the pad before calling @func.
3872 * Returns: a TRUE if the task could be started.
3875 gst_pad_start_task (GstPad * pad, GstTaskFunction func, gpointer data)
3879 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
3880 g_return_val_if_fail (func != NULL, FALSE);
3882 GST_OBJECT_LOCK (pad);
3883 task = GST_PAD_TASK (pad);
3885 task = gst_task_create (func, data);
3886 gst_task_set_lock (task, GST_PAD_GET_STREAM_LOCK (pad));
3887 GST_PAD_TASK (pad) = task;
3889 gst_task_start (task);
3890 GST_OBJECT_UNLOCK (pad);
3896 * gst_pad_pause_task:
3897 * @pad: the #GstPad to pause the task of
3899 * Pause the task of @pad. This function will also make sure that the
3900 * function executed by the task will effectively stop.
3902 * Returns: a TRUE if the task could be paused or FALSE when the pad
3906 gst_pad_pause_task (GstPad * pad)
3910 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
3912 GST_OBJECT_LOCK (pad);
3913 task = GST_PAD_TASK (pad);
3916 gst_task_pause (task);
3917 GST_OBJECT_UNLOCK (pad);
3919 GST_PAD_STREAM_LOCK (pad);
3920 GST_PAD_STREAM_UNLOCK (pad);
3926 GST_DEBUG_OBJECT (pad, "pad has no task");
3927 GST_OBJECT_UNLOCK (pad);
3933 * gst_pad_stop_task:
3934 * @pad: the #GstPad to stop the task of
3936 * Stop the task of @pad. This function will also make sure that the
3937 * function executed by the task will effectively stop if not called
3938 * from the GstTaskFunction.
3940 * This function will deadlock if called from the GstTaskFunction of
3941 * the task. Use gst_task_pause() instead.
3943 * Regardless of whether the pad has a task, the stream lock is acquired and
3944 * released so as to ensure that streaming through this pad has finished.
3946 * Returns: a TRUE if the task could be stopped or FALSE on error.
3949 gst_pad_stop_task (GstPad * pad)
3953 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
3955 GST_OBJECT_LOCK (pad);
3956 task = GST_PAD_TASK (pad);
3959 GST_PAD_TASK (pad) = NULL;
3960 gst_task_stop (task);
3961 GST_OBJECT_UNLOCK (pad);
3963 GST_PAD_STREAM_LOCK (pad);
3964 GST_PAD_STREAM_UNLOCK (pad);
3966 gst_task_join (task);
3968 gst_object_unref (task);
3974 GST_OBJECT_UNLOCK (pad);
3976 GST_PAD_STREAM_LOCK (pad);
3977 GST_PAD_STREAM_UNLOCK (pad);