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_peek_parent (klass);
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);
345 GST_PAD_ACCEPTCAPSFUNC (pad) = GST_DEBUG_FUNCPTR (gst_pad_acceptcaps_default);
348 pad->do_buffer_signals = 0;
349 pad->do_event_signals = 0;
351 GST_PAD_UNSET_FLUSHING (pad);
353 pad->preroll_lock = g_mutex_new ();
354 pad->preroll_cond = g_cond_new ();
356 pad->stream_rec_lock = g_new (GStaticRecMutex, 1);
357 g_static_rec_mutex_init (pad->stream_rec_lock);
359 pad->block_cond = g_cond_new ();
363 gst_pad_dispose (GObject * object)
365 GstPad *pad = GST_PAD (object);
367 GST_CAT_DEBUG (GST_CAT_REFCOUNTING, "dispose %s:%s",
368 GST_DEBUG_PAD_NAME (pad));
370 /* we don't hold a ref to the peer so we can just set the
372 GST_PAD_PEER (pad) = NULL;
375 gst_caps_replace (&GST_PAD_CAPS (pad), NULL);
377 gst_pad_set_pad_template (pad, NULL);
379 G_OBJECT_CLASS (parent_class)->dispose (object);
383 gst_pad_finalize (GObject * object)
385 GstPad *pad = GST_PAD (object);
388 /* in case the task is still around, clean it up */
389 if ((task = GST_PAD_TASK (pad))) {
390 gst_task_join (task);
391 GST_PAD_TASK (pad) = NULL;
392 gst_object_unref (task);
395 if (pad->stream_rec_lock) {
396 g_static_rec_mutex_free (pad->stream_rec_lock);
397 g_free (pad->stream_rec_lock);
398 pad->stream_rec_lock = NULL;
400 if (pad->preroll_lock) {
401 g_mutex_free (pad->preroll_lock);
402 g_cond_free (pad->preroll_cond);
403 pad->preroll_lock = NULL;
404 pad->preroll_cond = NULL;
406 if (pad->block_cond) {
407 g_cond_free (pad->block_cond);
408 pad->block_cond = NULL;
411 G_OBJECT_CLASS (parent_class)->finalize (object);
415 gst_pad_set_property (GObject * object, guint prop_id,
416 const GValue * value, GParamSpec * pspec)
418 g_return_if_fail (GST_IS_PAD (object));
421 case PAD_PROP_DIRECTION:
422 GST_PAD_DIRECTION (object) = g_value_get_enum (value);
424 case PAD_PROP_TEMPLATE:
425 gst_pad_set_pad_template (GST_PAD_CAST (object),
426 (GstPadTemplate *) g_value_get_object (value));
429 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
435 gst_pad_get_property (GObject * object, guint prop_id,
436 GValue * value, GParamSpec * pspec)
438 g_return_if_fail (GST_IS_PAD (object));
442 g_value_set_boxed (value, GST_PAD_CAPS (object));
444 case PAD_PROP_DIRECTION:
445 g_value_set_enum (value, GST_PAD_DIRECTION (object));
447 case PAD_PROP_TEMPLATE:
448 g_value_set_object (value, GST_PAD_PAD_TEMPLATE (object));
451 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
458 * @name: the name of the new pad.
459 * @direction: the #GstPadDirection of the pad.
461 * Creates a new pad with the given name in the given direction.
462 * If name is NULL, a guaranteed unique name (across all pads)
464 * This function makes a copy of the name so you can safely free the name.
466 * Returns: a new #GstPad, or NULL in case of an error.
471 gst_pad_new (const gchar * name, GstPadDirection direction)
473 return g_object_new (GST_TYPE_PAD,
474 "name", name, "direction", direction, NULL);
478 * gst_pad_new_from_template:
479 * @templ: the pad template to use
480 * @name: the name of the element
482 * Creates a new pad with the given name from the given template.
483 * If name is NULL, a guaranteed unique name (across all pads)
485 * This function makes a copy of the name so you can safely free the name.
487 * Returns: a new #GstPad, or NULL in case of an error.
490 gst_pad_new_from_template (GstPadTemplate * templ, const gchar * name)
492 g_return_val_if_fail (GST_IS_PAD_TEMPLATE (templ), NULL);
494 return g_object_new (GST_TYPE_PAD,
495 "name", name, "direction", templ->direction, "template", templ, NULL);
499 * gst_pad_new_from_static_template:
500 * @templ: the #GstStaticPadTemplate to use
501 * @name: the name of the element
503 * Creates a new pad with the given name from the given static template.
504 * If name is NULL, a guaranteed unique name (across all pads)
506 * This function makes a copy of the name so you can safely free the name.
508 * Returns: a new #GstPad, or NULL in case of an error.
511 gst_pad_new_from_static_template (GstStaticPadTemplate * templ,
515 GstPadTemplate *template;
517 template = gst_static_pad_template_get (templ);
518 pad = gst_pad_new_from_template (template, name);
519 gst_object_unref (template);
524 * gst_pad_get_direction:
525 * @pad: a #GstPad to get the direction of.
527 * Gets the direction of the pad. The direction of the pad is
528 * decided at construction time so this function does not take
531 * Returns: the #GstPadDirection of the pad.
536 gst_pad_get_direction (GstPad * pad)
538 GstPadDirection result;
540 /* PAD_UNKNOWN is a little silly but we need some sort of
541 * error return value */
542 g_return_val_if_fail (GST_IS_PAD (pad), GST_PAD_UNKNOWN);
544 GST_OBJECT_LOCK (pad);
545 result = GST_PAD_DIRECTION (pad);
546 GST_OBJECT_UNLOCK (pad);
552 gst_pad_activate_default (GstPad * pad)
554 return gst_pad_activate_push (pad, TRUE);
558 pre_activate (GstPad * pad, GstActivateMode new_mode)
561 case GST_ACTIVATE_PUSH:
562 case GST_ACTIVATE_PULL:
563 GST_OBJECT_LOCK (pad);
564 GST_DEBUG_OBJECT (pad, "setting ACTIVATE_MODE %d, unset flushing",
566 GST_PAD_UNSET_FLUSHING (pad);
567 GST_PAD_ACTIVATE_MODE (pad) = new_mode;
568 GST_OBJECT_UNLOCK (pad);
570 case GST_ACTIVATE_NONE:
571 GST_OBJECT_LOCK (pad);
572 GST_DEBUG_OBJECT (pad, "setting ACTIVATE_MODE NONE, set flushing",
574 GST_PAD_SET_FLUSHING (pad);
575 /* unlock blocked pads so element can resume and stop */
576 GST_PAD_BLOCK_SIGNAL (pad);
577 GST_OBJECT_UNLOCK (pad);
583 post_activate (GstPad * pad, GstActivateMode new_mode)
586 case GST_ACTIVATE_PUSH:
587 case GST_ACTIVATE_PULL:
590 case GST_ACTIVATE_NONE:
591 /* ensures that streaming stops */
592 GST_PAD_STREAM_LOCK (pad);
593 /* while we're at it set activation mode */
594 GST_OBJECT_LOCK (pad);
595 GST_DEBUG_OBJECT (pad, "setting ACTIVATE_MODE %d", new_mode);
596 GST_PAD_ACTIVATE_MODE (pad) = new_mode;
597 GST_OBJECT_UNLOCK (pad);
598 GST_PAD_STREAM_UNLOCK (pad);
604 * gst_pad_set_active:
605 * @pad: the #GstPad to activate or deactivate.
606 * @active: whether or not the pad should be active.
608 * Activates or deactivates the given pad.
609 * Normally called from within core state change functions.
611 * If @active, makes sure the pad is active. If it is already active, either in
612 * push or pull mode, just return. Otherwise dispatches to the pad's activate
613 * function to perform the actual activation.
615 * If not @active, checks the pad's current mode and calls
616 * gst_pad_activate_push() or gst_pad_activate_pull(), as appropriate, with a
619 * Returns: #TRUE if the operation was successful.
624 gst_pad_set_active (GstPad * pad, gboolean active)
627 gboolean ret = FALSE;
629 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
631 GST_OBJECT_LOCK (pad);
632 old = GST_PAD_ACTIVATE_MODE (pad);
633 GST_OBJECT_UNLOCK (pad);
637 case GST_ACTIVATE_PUSH:
638 case GST_ACTIVATE_PULL:
641 case GST_ACTIVATE_NONE:
642 ret = (GST_PAD_ACTIVATEFUNC (pad)) (pad);
647 case GST_ACTIVATE_PUSH:
648 ret = gst_pad_activate_push (pad, FALSE);
650 case GST_ACTIVATE_PULL:
651 ret = gst_pad_activate_pull (pad, FALSE);
653 case GST_ACTIVATE_NONE:
659 if (!active && !ret) {
660 GST_OBJECT_LOCK (pad);
661 g_critical ("Failed to deactivate pad %s:%s, very bad",
662 GST_DEBUG_PAD_NAME (pad));
663 GST_OBJECT_UNLOCK (pad);
670 * gst_pad_activate_pull:
671 * @pad: the #GstPad to activate or deactivate.
672 * @active: whether or not the pad should be active.
674 * Activates or deactivates the given pad in pull mode via dispatching to the
675 * pad's activatepullfunc. For use from within pad activation functions only.
676 * When called on sink pads, will first proxy the call to the peer pad, which is
677 * expected to activate its internally linked pads from within its activate_pull
680 * If you don't know what this is, you probably don't want to call it.
682 * Returns: TRUE if the operation was successful.
687 gst_pad_activate_pull (GstPad * pad, gboolean active)
689 GstActivateMode old, new;
692 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
694 GST_OBJECT_LOCK (pad);
695 old = GST_PAD_ACTIVATE_MODE (pad);
696 GST_OBJECT_UNLOCK (pad);
698 if ((active && old == GST_ACTIVATE_PULL)
699 || (!active && old == GST_ACTIVATE_NONE))
703 g_return_val_if_fail (old == GST_ACTIVATE_NONE, FALSE);
705 g_return_val_if_fail (old == GST_ACTIVATE_PULL, FALSE);
708 if (gst_pad_get_direction (pad) == GST_PAD_SINK) {
709 if ((peer = gst_pad_get_peer (pad))) {
710 if (!gst_pad_activate_pull (peer, active))
712 gst_object_unref (peer);
715 if (GST_PAD_GETRANGEFUNC (pad) == NULL)
716 goto failure; /* Can't activate pull on a src without a
720 new = active ? GST_ACTIVATE_PULL : GST_ACTIVATE_NONE;
721 pre_activate (pad, new);
723 if (GST_PAD_ACTIVATEPULLFUNC (pad)) {
724 if (!GST_PAD_ACTIVATEPULLFUNC (pad) (pad, active))
727 /* can happen for sinks of passthrough elements */
730 post_activate (pad, new);
732 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "%s in pull mode",
733 active ? "activated" : "deactivated");
738 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "already %s in pull mode",
739 active ? "activated" : "deactivated");
744 GST_OBJECT_LOCK (peer);
745 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
746 "activate_pull on peer (%s:%s) failed", GST_DEBUG_PAD_NAME (peer));
747 GST_OBJECT_UNLOCK (peer);
748 gst_object_unref (peer);
753 GST_CAT_INFO_OBJECT (GST_CAT_PADS, pad, "failed to %s in pull mode",
754 active ? "activate" : "deactivate");
755 pre_activate (pad, GST_ACTIVATE_NONE);
756 post_activate (pad, GST_ACTIVATE_NONE);
762 * gst_pad_activate_push:
763 * @pad: the #GstPad to activate or deactivate.
764 * @active: whether the pad should be active or not.
766 * Activates or deactivates the given pad in push mode via dispatching to the
767 * pad's activatepushfunc. For use from within pad activation functions only.
769 * If you don't know what this is, you probably don't want to call it.
771 * Returns: %TRUE if the operation was successful.
776 gst_pad_activate_push (GstPad * pad, gboolean active)
778 GstActivateMode old, new;
780 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
781 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "trying to set %s in push mode",
782 active ? "activated" : "deactivated");
784 GST_OBJECT_LOCK (pad);
785 old = GST_PAD_ACTIVATE_MODE (pad);
786 GST_OBJECT_UNLOCK (pad);
788 if ((active && old == GST_ACTIVATE_PUSH)
789 || (!active && old == GST_ACTIVATE_NONE))
793 g_return_val_if_fail (old == GST_ACTIVATE_NONE, FALSE);
795 g_return_val_if_fail (old == GST_ACTIVATE_PUSH, FALSE);
798 new = active ? GST_ACTIVATE_PUSH : GST_ACTIVATE_NONE;
799 pre_activate (pad, new);
801 if (GST_PAD_ACTIVATEPUSHFUNC (pad)) {
802 if (!GST_PAD_ACTIVATEPUSHFUNC (pad) (pad, active)) {
806 /* quite ok, element relies on state change func to prepare itself */
809 post_activate (pad, new);
811 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "%s in push mode",
812 active ? "activated" : "deactivated");
817 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "already %s in push mode",
818 active ? "activated" : "deactivated");
823 GST_CAT_INFO_OBJECT (GST_CAT_PADS, pad, "failed to %s in push mode",
824 active ? "activate" : "deactivate");
825 pre_activate (pad, GST_ACTIVATE_NONE);
826 post_activate (pad, GST_ACTIVATE_NONE);
833 * @pad: the #GstPad to query
835 * Query if a pad is active
837 * Returns: TRUE if the pad is active.
842 gst_pad_is_active (GstPad * pad)
844 gboolean result = FALSE;
846 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
848 GST_OBJECT_LOCK (pad);
849 result = GST_PAD_MODE_ACTIVATE (GST_PAD_ACTIVATE_MODE (pad));
850 GST_OBJECT_UNLOCK (pad);
856 * gst_pad_set_blocked_async:
857 * @pad: the #GstPad to block or unblock
858 * @blocked: boolean indicating whether the pad should be blocked or unblocked
859 * @callback: #GstPadBlockCallback that will be called when the
861 * @user_data: user data passed to the callback
863 * Blocks or unblocks the dataflow on a pad. The provided callback
864 * is called when the operation succeeds; this happens right before the next
865 * attempt at pushing a buffer on the pad.
867 * This can take a while as the pad can only become blocked when real dataflow
869 * When the pipeline is stalled, for example in PAUSED, this can
870 * take an indeterminate amount of time.
871 * You can pass NULL as the callback to make this call block. Be careful with
872 * this blocking call as it might not return for reasons stated above.
874 * Returns: TRUE if the pad could be blocked. This function can fail
875 * if wrong parameters were passed or the pad was already in the
881 gst_pad_set_blocked_async (GstPad * pad, gboolean blocked,
882 GstPadBlockCallback callback, gpointer user_data)
884 gboolean was_blocked, was_ghost = FALSE;
886 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
888 if (GST_IS_GHOST_PAD (pad)) {
889 pad = gst_ghost_pad_get_target (GST_GHOST_PAD (pad));
896 GST_OBJECT_LOCK (pad);
898 was_blocked = GST_PAD_IS_BLOCKED (pad);
900 if (G_UNLIKELY (was_blocked == blocked))
901 goto had_right_state;
904 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "blocking pad %s:%s",
905 GST_DEBUG_PAD_NAME (pad));
907 GST_OBJECT_FLAG_SET (pad, GST_PAD_BLOCKED);
908 pad->block_callback = callback;
909 pad->block_data = user_data;
911 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "waiting for block");
912 GST_PAD_BLOCK_WAIT (pad);
913 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "blocked");
916 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "unblocking pad %s:%s",
917 GST_DEBUG_PAD_NAME (pad));
919 GST_OBJECT_FLAG_UNSET (pad, GST_PAD_BLOCKED);
921 pad->block_callback = callback;
922 pad->block_data = user_data;
925 GST_PAD_BLOCK_SIGNAL (pad);
927 GST_PAD_BLOCK_SIGNAL (pad);
928 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "waiting for unblock");
929 GST_PAD_BLOCK_WAIT (pad);
930 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "unblocked");
933 GST_OBJECT_UNLOCK (pad);
936 gst_object_unref (pad);
943 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
944 "pad %s:%s was in right state (%d)", GST_DEBUG_PAD_NAME (pad),
946 GST_OBJECT_UNLOCK (pad);
949 gst_object_unref (pad);
956 * gst_pad_set_blocked:
957 * @pad: the #GstPad to block or unblock
958 * @blocked: boolean indicating we should block or unblock
960 * Blocks or unblocks the dataflow on a pad. This function is
961 * a shortcut for gst_pad_set_blocked_async() with a NULL
964 * Returns: TRUE if the pad could be blocked. This function can fail
965 * wrong parameters were passed or the pad was already in the
971 gst_pad_set_blocked (GstPad * pad, gboolean blocked)
973 return gst_pad_set_blocked_async (pad, blocked, NULL, NULL);
977 * gst_pad_is_blocked:
978 * @pad: the #GstPad to query
980 * Checks if the pad is blocked or not. This function returns the
981 * last requested state of the pad. It is not certain that the pad
982 * is actually blocked at this point.
984 * Returns: TRUE if the pad is blocked.
989 gst_pad_is_blocked (GstPad * pad)
991 gboolean result = FALSE;
993 g_return_val_if_fail (GST_IS_PAD (pad), result);
995 GST_OBJECT_LOCK (pad);
996 result = GST_OBJECT_FLAG_IS_SET (pad, GST_PAD_BLOCKED);
997 GST_OBJECT_UNLOCK (pad);
1003 * gst_pad_set_activate_function:
1004 * @pad: a sink #GstPad.
1005 * @activate: the #GstPadActivateFunction to set.
1007 * Sets the given activate function for the pad. The activate function will
1008 * dispatch to activate_push or activate_pull to perform the actual activation.
1009 * Only makes sense to set on sink pads.
1011 * Call this function if your sink pad can start a pull-based task.
1014 gst_pad_set_activate_function (GstPad * pad, GstPadActivateFunction activate)
1016 g_return_if_fail (GST_IS_PAD (pad));
1018 GST_PAD_ACTIVATEFUNC (pad) = activate;
1019 GST_CAT_DEBUG (GST_CAT_PADS, "activatefunc for %s:%s set to %s",
1020 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (activate));
1024 * gst_pad_set_activatepull_function:
1025 * @pad: a sink #GstPad.
1026 * @activatepull: the #GstPadActivateModeFunction to set.
1028 * Sets the given activate_pull function for the pad. An activate_pull function
1029 * prepares the element and any upstream connections for pulling. See XXX
1030 * part-activation.txt for details.
1033 gst_pad_set_activatepull_function (GstPad * pad,
1034 GstPadActivateModeFunction activatepull)
1036 g_return_if_fail (GST_IS_PAD (pad));
1038 GST_PAD_ACTIVATEPULLFUNC (pad) = activatepull;
1039 GST_CAT_DEBUG (GST_CAT_PADS, "activatepullfunc for %s:%s set to %s",
1040 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (activatepull));
1044 * gst_pad_set_activatepush_function:
1045 * @pad: a sink #GstPad.
1046 * @activatepush: the #GstPadActivateModeFunction to set.
1048 * Sets the given activate_push function for the pad. An activate_push function
1049 * prepares the element for pushing. See XXX part-activation.txt for details.
1052 gst_pad_set_activatepush_function (GstPad * pad,
1053 GstPadActivateModeFunction activatepush)
1055 g_return_if_fail (GST_IS_PAD (pad));
1057 GST_PAD_ACTIVATEPUSHFUNC (pad) = activatepush;
1058 GST_CAT_DEBUG (GST_CAT_PADS, "activatepushfunc for %s:%s set to %s",
1059 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (activatepush));
1063 * gst_pad_set_chain_function:
1064 * @pad: a sink #GstPad.
1065 * @chain: the #GstPadChainFunction to set.
1067 * Sets the given chain function for the pad. The chain function is called to
1068 * process a #GstBuffer input buffer.
1071 gst_pad_set_chain_function (GstPad * pad, GstPadChainFunction chain)
1073 g_return_if_fail (GST_IS_PAD (pad));
1074 g_return_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SINK);
1076 GST_PAD_CHAINFUNC (pad) = chain;
1077 GST_CAT_DEBUG (GST_CAT_PADS, "chainfunc for %s:%s set to %s",
1078 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (chain));
1082 * gst_pad_set_getrange_function:
1083 * @pad: a source #GstPad.
1084 * @get: the #GstPadGetRangeFunction to set.
1086 * Sets the given getrange function for the pad. The getrange function is called to
1087 * produce a new #GstBuffer to start the processing pipeline. Getrange functions cannot
1091 gst_pad_set_getrange_function (GstPad * pad, GstPadGetRangeFunction get)
1093 g_return_if_fail (GST_IS_PAD (pad));
1094 g_return_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SRC);
1096 GST_PAD_GETRANGEFUNC (pad) = get;
1098 GST_CAT_DEBUG (GST_CAT_PADS, "getrangefunc for %s:%s set to %s",
1099 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (get));
1103 * gst_pad_set_checkgetrange_function:
1104 * @pad: a source #GstPad.
1105 * @check: the #GstPadCheckGetRangeFunction to set.
1107 * Sets the given checkgetrange function for the pad. Implement this function on
1108 * a pad if you dynamically support getrange based scheduling on the pad.
1111 gst_pad_set_checkgetrange_function (GstPad * pad,
1112 GstPadCheckGetRangeFunction check)
1114 g_return_if_fail (GST_IS_PAD (pad));
1115 g_return_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SRC);
1117 GST_PAD_CHECKGETRANGEFUNC (pad) = check;
1119 GST_CAT_DEBUG (GST_CAT_PADS, "checkgetrangefunc for %s:%s set to %s",
1120 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (check));
1124 * gst_pad_set_event_function:
1125 * @pad: a source #GstPad.
1126 * @event: the #GstPadEventFunction to set.
1128 * Sets the given event handler for the pad.
1131 gst_pad_set_event_function (GstPad * pad, GstPadEventFunction event)
1133 g_return_if_fail (GST_IS_PAD (pad));
1135 GST_PAD_EVENTFUNC (pad) = event;
1137 GST_CAT_DEBUG (GST_CAT_PADS, "eventfunc for %s:%s set to %s",
1138 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (event));
1142 * gst_pad_set_query_function:
1143 * @pad: a #GstPad of either direction.
1144 * @query: the #GstPadQueryFunction to set.
1146 * Set the given query function for the pad.
1149 gst_pad_set_query_function (GstPad * pad, GstPadQueryFunction query)
1151 g_return_if_fail (GST_IS_PAD (pad));
1153 GST_PAD_QUERYFUNC (pad) = query;
1155 GST_CAT_DEBUG (GST_CAT_PADS, "queryfunc for %s:%s set to %s",
1156 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (query));
1160 * gst_pad_set_query_type_function:
1161 * @pad: a #GstPad of either direction.
1162 * @type_func: the #GstPadQueryTypeFunction to set.
1164 * Set the given query type function for the pad.
1167 gst_pad_set_query_type_function (GstPad * pad,
1168 GstPadQueryTypeFunction type_func)
1170 g_return_if_fail (GST_IS_PAD (pad));
1172 GST_PAD_QUERYTYPEFUNC (pad) = type_func;
1174 GST_CAT_DEBUG (GST_CAT_PADS, "querytypefunc for %s:%s set to %s",
1175 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (type_func));
1179 * gst_pad_get_query_types:
1182 * Get an array of supported queries that can be performed
1185 * Returns: a zero-terminated array of #GstQueryType.
1187 const GstQueryType *
1188 gst_pad_get_query_types (GstPad * pad)
1190 GstPadQueryTypeFunction func;
1192 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
1194 if (G_UNLIKELY ((func = GST_PAD_QUERYTYPEFUNC (pad)) == NULL))
1206 gst_pad_get_query_types_dispatcher (GstPad * pad, const GstQueryType ** data)
1208 *data = gst_pad_get_query_types (pad);
1214 * gst_pad_get_query_types_default:
1217 * Invoke the default dispatcher for the query types on
1220 * Returns: an zero-terminated array of #GstQueryType, or NULL if none of the
1221 * internally-linked pads has a query types function.
1223 const GstQueryType *
1224 gst_pad_get_query_types_default (GstPad * pad)
1226 GstQueryType *result = NULL;
1228 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
1230 gst_pad_dispatcher (pad, (GstPadDispatcherFunction)
1231 gst_pad_get_query_types_dispatcher, &result);
1237 * gst_pad_set_internal_link_function:
1238 * @pad: a #GstPad of either direction.
1239 * @intlink: the #GstPadIntLinkFunction to set.
1241 * Sets the given internal link function for the pad.
1244 gst_pad_set_internal_link_function (GstPad * pad, GstPadIntLinkFunction intlink)
1246 g_return_if_fail (GST_IS_PAD (pad));
1248 GST_PAD_INTLINKFUNC (pad) = intlink;
1249 GST_CAT_DEBUG (GST_CAT_PADS, "internal link for %s:%s set to %s",
1250 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (intlink));
1254 * gst_pad_set_link_function:
1256 * @link: the #GstPadLinkFunction to set.
1258 * Sets the given link function for the pad. It will be called when
1259 * the pad is linked with another pad.
1261 * The return value #GST_PAD_LINK_OK should be used when the connection can be
1264 * The return value #GST_PAD_LINK_REFUSED should be used when the connection
1265 * cannot be made for some reason.
1267 * If @link is installed on a source pad, it should call the #GstPadLinkFunction
1268 * of the peer sink pad, if present.
1271 gst_pad_set_link_function (GstPad * pad, GstPadLinkFunction link)
1273 g_return_if_fail (GST_IS_PAD (pad));
1275 GST_PAD_LINKFUNC (pad) = link;
1276 GST_CAT_DEBUG (GST_CAT_PADS, "linkfunc for %s:%s set to %s",
1277 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (link));
1281 * gst_pad_set_unlink_function:
1283 * @unlink: the #GstPadUnlinkFunction to set.
1285 * Sets the given unlink function for the pad. It will be called
1286 * when the pad is unlinked.
1289 gst_pad_set_unlink_function (GstPad * pad, GstPadUnlinkFunction unlink)
1291 g_return_if_fail (GST_IS_PAD (pad));
1293 GST_PAD_UNLINKFUNC (pad) = unlink;
1294 GST_CAT_DEBUG (GST_CAT_PADS, "unlinkfunc for %s:%s set to %s",
1295 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (unlink));
1299 * gst_pad_set_getcaps_function:
1301 * @getcaps: the #GstPadGetCapsFunction to set.
1303 * Sets the given getcaps function for the pad. @getcaps should return the
1304 * allowable caps for a pad in the context of the element's state, its link to
1305 * other elements, and the devices or files it has opened. These caps must be a
1306 * subset of the pad template caps. In the NULL state with no links, @getcaps
1307 * should ideally return the same caps as the pad template. In rare
1308 * circumstances, an object property can affect the caps returned by @getcaps,
1309 * but this is discouraged.
1311 * You do not need to call this function if @pad's allowed caps are always the
1312 * same as the pad template caps. This can only be true if the padtemplate
1313 * has fixed simple caps.
1315 * For most filters, the caps returned by @getcaps is directly affected by the
1316 * allowed caps on other pads. For demuxers and decoders, the caps returned by
1317 * the srcpad's getcaps function is directly related to the stream data. Again,
1318 * @getcaps should return the most specific caps it reasonably can, since this
1319 * helps with autoplugging.
1321 * Note that the return value from @getcaps is owned by the caller, so the caller
1322 * should unref the caps after usage.
1325 gst_pad_set_getcaps_function (GstPad * pad, GstPadGetCapsFunction getcaps)
1327 g_return_if_fail (GST_IS_PAD (pad));
1329 GST_PAD_GETCAPSFUNC (pad) = getcaps;
1330 GST_CAT_DEBUG (GST_CAT_PADS, "getcapsfunc for %s:%s set to %s",
1331 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (getcaps));
1335 * gst_pad_set_acceptcaps_function:
1337 * @acceptcaps: the #GstPadAcceptCapsFunction to set.
1339 * Sets the given acceptcaps function for the pad. The acceptcaps function
1340 * will be called to check if the pad can accept the given caps.
1343 * acceptcaps function to NULL restores the default behaviour of allowing
1344 * any caps that matches the caps from gst_pad_get_caps.
1347 gst_pad_set_acceptcaps_function (GstPad * pad,
1348 GstPadAcceptCapsFunction acceptcaps)
1350 g_return_if_fail (GST_IS_PAD (pad));
1352 GST_PAD_ACCEPTCAPSFUNC (pad) = acceptcaps;
1353 GST_CAT_DEBUG (GST_CAT_PADS, "acceptcapsfunc for %s:%s set to %s",
1354 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (acceptcaps));
1358 * gst_pad_set_fixatecaps_function:
1360 * @fixatecaps: the #GstPadFixateCapsFunction to set.
1362 * Sets the given fixatecaps function for the pad. The fixatecaps function
1363 * will be called whenever the default values for a GstCaps needs to be
1367 gst_pad_set_fixatecaps_function (GstPad * pad,
1368 GstPadFixateCapsFunction fixatecaps)
1370 g_return_if_fail (GST_IS_PAD (pad));
1372 GST_PAD_FIXATECAPSFUNC (pad) = fixatecaps;
1373 GST_CAT_DEBUG (GST_CAT_PADS, "fixatecapsfunc for %s:%s set to %s",
1374 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (fixatecaps));
1378 * gst_pad_set_setcaps_function:
1380 * @setcaps: the #GstPadSetCapsFunction to set.
1382 * Sets the given setcaps function for the pad. The setcaps function
1383 * will be called whenever a buffer with a new media type is pushed or
1384 * pulled from the pad. The pad/element needs to update its internal
1385 * structures to process the new media type. If this new type is not
1386 * acceptable, the setcaps function should return FALSE.
1389 gst_pad_set_setcaps_function (GstPad * pad, GstPadSetCapsFunction setcaps)
1391 g_return_if_fail (GST_IS_PAD (pad));
1393 GST_PAD_SETCAPSFUNC (pad) = setcaps;
1394 GST_CAT_DEBUG (GST_CAT_PADS, "setcapsfunc for %s:%s set to %s",
1395 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (setcaps));
1399 * gst_pad_set_bufferalloc_function:
1400 * @pad: a sink #GstPad.
1401 * @bufalloc: the #GstPadBufferAllocFunction to set.
1403 * Sets the given bufferalloc function for the pad. Note that the
1404 * bufferalloc function can only be set on sinkpads.
1407 gst_pad_set_bufferalloc_function (GstPad * pad,
1408 GstPadBufferAllocFunction bufalloc)
1410 g_return_if_fail (GST_IS_PAD (pad));
1411 g_return_if_fail (GST_PAD_IS_SINK (pad));
1413 GST_PAD_BUFFERALLOCFUNC (pad) = bufalloc;
1414 GST_CAT_DEBUG (GST_CAT_PADS, "bufferallocfunc for %s:%s set to %s",
1415 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (bufalloc));
1420 * @srcpad: the source #GstPad to unlink.
1421 * @sinkpad: the sink #GstPad to unlink.
1423 * Unlinks the source pad from the sink pad. Will emit the "unlinked" signal on
1426 * Returns: TRUE if the pads were unlinked. This function returns FALSE if
1427 * the pads were not linked together.
1432 gst_pad_unlink (GstPad * srcpad, GstPad * sinkpad)
1434 g_return_val_if_fail (GST_IS_PAD (srcpad), FALSE);
1435 g_return_val_if_fail (GST_IS_PAD (sinkpad), FALSE);
1437 GST_CAT_INFO (GST_CAT_ELEMENT_PADS, "unlinking %s:%s(%p) and %s:%s(%p)",
1438 GST_DEBUG_PAD_NAME (srcpad), srcpad,
1439 GST_DEBUG_PAD_NAME (sinkpad), sinkpad);
1441 GST_OBJECT_LOCK (srcpad);
1443 if (G_UNLIKELY (GST_PAD_DIRECTION (srcpad) != GST_PAD_SRC))
1446 GST_OBJECT_LOCK (sinkpad);
1448 if (G_UNLIKELY (GST_PAD_DIRECTION (sinkpad) != GST_PAD_SINK))
1451 if (G_UNLIKELY (GST_PAD_PEER (srcpad) != sinkpad))
1452 goto not_linked_together;
1454 if (GST_PAD_UNLINKFUNC (srcpad)) {
1455 GST_PAD_UNLINKFUNC (srcpad) (srcpad);
1457 if (GST_PAD_UNLINKFUNC (sinkpad)) {
1458 GST_PAD_UNLINKFUNC (sinkpad) (sinkpad);
1461 /* first clear peers */
1462 GST_PAD_PEER (srcpad) = NULL;
1463 GST_PAD_PEER (sinkpad) = NULL;
1465 GST_OBJECT_UNLOCK (sinkpad);
1466 GST_OBJECT_UNLOCK (srcpad);
1468 /* fire off a signal to each of the pads telling them
1469 * that they've been unlinked */
1470 g_signal_emit (G_OBJECT (srcpad), gst_pad_signals[PAD_UNLINKED], 0, sinkpad);
1471 g_signal_emit (G_OBJECT (sinkpad), gst_pad_signals[PAD_UNLINKED], 0, srcpad);
1473 GST_CAT_INFO (GST_CAT_ELEMENT_PADS, "unlinked %s:%s and %s:%s",
1474 GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (sinkpad));
1480 g_critical ("pad %s is not a source pad", GST_PAD_NAME (srcpad));
1481 GST_OBJECT_UNLOCK (srcpad);
1486 g_critical ("pad %s is not a sink pad", GST_PAD_NAME (sinkpad));
1487 GST_OBJECT_UNLOCK (sinkpad);
1488 GST_OBJECT_UNLOCK (srcpad);
1491 not_linked_together:
1493 /* we do not emit a warning in this case because unlinking cannot
1494 * be made MT safe.*/
1495 GST_OBJECT_UNLOCK (sinkpad);
1496 GST_OBJECT_UNLOCK (srcpad);
1502 * gst_pad_is_linked:
1503 * @pad: pad to check
1505 * Checks if a @pad is linked to another pad or not.
1507 * Returns: TRUE if the pad is linked, FALSE otherwise.
1512 gst_pad_is_linked (GstPad * pad)
1516 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
1518 GST_OBJECT_LOCK (pad);
1519 result = (GST_PAD_PEER (pad) != NULL);
1520 GST_OBJECT_UNLOCK (pad);
1525 /* get the caps from both pads and see if the intersection
1528 * This function should be called with the pad LOCK on both
1532 gst_pad_link_check_compatible_unlocked (GstPad * src, GstPad * sink)
1538 srccaps = gst_pad_get_caps_unlocked (src);
1539 sinkcaps = gst_pad_get_caps_unlocked (sink);
1541 GST_CAT_DEBUG (GST_CAT_CAPS, "src caps %" GST_PTR_FORMAT, srccaps);
1542 GST_CAT_DEBUG (GST_CAT_CAPS, "sink caps %" GST_PTR_FORMAT, sinkcaps);
1544 /* if we have caps on both pads we can check the intersection. If one
1545 * of the caps is NULL, we return TRUE. */
1546 if (srccaps == NULL || sinkcaps == NULL)
1549 icaps = gst_caps_intersect (srccaps, sinkcaps);
1550 gst_caps_unref (srccaps);
1551 gst_caps_unref (sinkcaps);
1556 GST_CAT_DEBUG (GST_CAT_CAPS,
1557 "intersection caps %p %" GST_PTR_FORMAT, icaps, icaps);
1559 if (gst_caps_is_empty (icaps))
1562 gst_caps_unref (icaps);
1567 /* incompatible cases */
1570 GST_CAT_DEBUG (GST_CAT_CAPS, "intersection gave NULL");
1575 GST_CAT_DEBUG (GST_CAT_CAPS, "intersection is EMPTY");
1576 gst_caps_unref (icaps);
1581 /* check if the grandparents of both pads are the same.
1582 * This check is required so that we don't try to link
1583 * pads from elements in different bins without ghostpads.
1585 * The LOCK should be helt on both pads
1588 gst_pad_link_check_hierarchy (GstPad * src, GstPad * sink)
1590 GstObject *psrc, *psink;
1591 gboolean res = TRUE;
1593 psrc = GST_OBJECT_PARENT (src);
1594 psink = GST_OBJECT_PARENT (sink);
1596 /* if one of the pads has no parent, we allow the link */
1597 if (psrc && psink) {
1598 /* if the parents are the same, we have a loop */
1599 if (psrc == psink) {
1600 GST_CAT_DEBUG (GST_CAT_CAPS, "pads have same parent %" GST_PTR_FORMAT,
1605 /* if they both have a parent, we check the grandparents */
1606 psrc = gst_object_get_parent (psrc);
1607 psink = gst_object_get_parent (psink);
1609 if (psrc != psink) {
1610 /* if they have grandparents but they are not the same */
1611 GST_CAT_DEBUG (GST_CAT_CAPS,
1612 "pads have different grandparents %" GST_PTR_FORMAT " and %"
1613 GST_PTR_FORMAT, psrc, psink);
1617 gst_object_unref (psrc);
1619 gst_object_unref (psink);
1625 /* FIXME leftover from an attempt at refactoring... */
1626 /* call with the two pads unlocked */
1627 static GstPadLinkReturn
1628 gst_pad_link_prepare (GstPad * srcpad, GstPad * sinkpad)
1630 /* generic checks */
1631 g_return_val_if_fail (GST_IS_PAD (srcpad), GST_PAD_LINK_REFUSED);
1632 g_return_val_if_fail (GST_IS_PAD (sinkpad), GST_PAD_LINK_REFUSED);
1634 GST_CAT_INFO (GST_CAT_PADS, "trying to link %s:%s and %s:%s",
1635 GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (sinkpad));
1637 GST_OBJECT_LOCK (srcpad);
1639 if (G_UNLIKELY (GST_PAD_DIRECTION (srcpad) != GST_PAD_SRC))
1642 if (G_UNLIKELY (GST_PAD_PEER (srcpad) != NULL))
1643 goto src_was_linked;
1645 GST_OBJECT_LOCK (sinkpad);
1647 if (G_UNLIKELY (GST_PAD_DIRECTION (sinkpad) != GST_PAD_SINK))
1650 if (G_UNLIKELY (GST_PAD_PEER (sinkpad) != NULL))
1651 goto sink_was_linked;
1653 /* check hierarchy, pads can only be linked if the grandparents
1655 if (!gst_pad_link_check_hierarchy (srcpad, sinkpad))
1656 goto wrong_hierarchy;
1658 /* check pad caps for non-empty intersection */
1659 if (!gst_pad_link_check_compatible_unlocked (srcpad, sinkpad))
1662 /* FIXME check pad scheduling for non-empty intersection */
1664 return GST_PAD_LINK_OK;
1668 g_critical ("pad %s is not a source pad", GST_PAD_NAME (srcpad));
1669 GST_OBJECT_UNLOCK (srcpad);
1670 return GST_PAD_LINK_WRONG_DIRECTION;
1674 GST_CAT_INFO (GST_CAT_PADS, "src %s:%s was already linked",
1675 GST_DEBUG_PAD_NAME (srcpad));
1676 /* we do not emit a warning in this case because unlinking cannot
1677 * be made MT safe.*/
1678 GST_OBJECT_UNLOCK (srcpad);
1679 return GST_PAD_LINK_WAS_LINKED;
1683 g_critical ("pad %s is not a sink pad", GST_PAD_NAME (sinkpad));
1684 GST_OBJECT_UNLOCK (sinkpad);
1685 GST_OBJECT_UNLOCK (srcpad);
1686 return GST_PAD_LINK_WRONG_DIRECTION;
1690 GST_CAT_INFO (GST_CAT_PADS, "sink %s:%s was already linked",
1691 GST_DEBUG_PAD_NAME (sinkpad));
1692 /* we do not emit a warning in this case because unlinking cannot
1693 * be made MT safe.*/
1694 GST_OBJECT_UNLOCK (sinkpad);
1695 GST_OBJECT_UNLOCK (srcpad);
1696 return GST_PAD_LINK_WAS_LINKED;
1700 GST_CAT_INFO (GST_CAT_PADS, "pads have wrong hierarchy");
1701 GST_OBJECT_UNLOCK (sinkpad);
1702 GST_OBJECT_UNLOCK (srcpad);
1703 return GST_PAD_LINK_WRONG_HIERARCHY;
1707 GST_CAT_INFO (GST_CAT_PADS, "caps are incompatible");
1708 GST_OBJECT_UNLOCK (sinkpad);
1709 GST_OBJECT_UNLOCK (srcpad);
1710 return GST_PAD_LINK_NOFORMAT;
1716 * @srcpad: the source #GstPad to link.
1717 * @sinkpad: the sink #GstPad to link.
1719 * Links the source pad and the sink pad.
1721 * Returns: A result code indicating if the connection worked or
1727 gst_pad_link (GstPad * srcpad, GstPad * sinkpad)
1729 GstPadLinkReturn result;
1731 /* prepare will also lock the two pads */
1732 result = gst_pad_link_prepare (srcpad, sinkpad);
1734 if (result != GST_PAD_LINK_OK)
1735 goto prepare_failed;
1737 /* must set peers before calling the link function */
1738 GST_PAD_PEER (srcpad) = sinkpad;
1739 GST_PAD_PEER (sinkpad) = srcpad;
1741 GST_OBJECT_UNLOCK (sinkpad);
1742 GST_OBJECT_UNLOCK (srcpad);
1744 /* FIXME released the locks here, concurrent thread might link
1745 * something else. */
1746 if (GST_PAD_LINKFUNC (srcpad)) {
1747 /* this one will call the peer link function */
1748 result = GST_PAD_LINKFUNC (srcpad) (srcpad, sinkpad);
1749 } else if (GST_PAD_LINKFUNC (sinkpad)) {
1750 /* if no source link function, we need to call the sink link
1751 * function ourselves. */
1752 result = GST_PAD_LINKFUNC (sinkpad) (sinkpad, srcpad);
1754 result = GST_PAD_LINK_OK;
1757 GST_OBJECT_LOCK (srcpad);
1758 GST_OBJECT_LOCK (sinkpad);
1760 if (result == GST_PAD_LINK_OK) {
1761 GST_OBJECT_UNLOCK (sinkpad);
1762 GST_OBJECT_UNLOCK (srcpad);
1764 /* fire off a signal to each of the pads telling them
1765 * that they've been linked */
1766 g_signal_emit (G_OBJECT (srcpad), gst_pad_signals[PAD_LINKED], 0, sinkpad);
1767 g_signal_emit (G_OBJECT (sinkpad), gst_pad_signals[PAD_LINKED], 0, srcpad);
1769 GST_CAT_INFO (GST_CAT_PADS, "linked %s:%s and %s:%s, successful",
1770 GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (sinkpad));
1772 GST_CAT_INFO (GST_CAT_PADS, "link between %s:%s and %s:%s failed",
1773 GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (sinkpad));
1775 GST_PAD_PEER (srcpad) = NULL;
1776 GST_PAD_PEER (sinkpad) = NULL;
1778 GST_OBJECT_UNLOCK (sinkpad);
1779 GST_OBJECT_UNLOCK (srcpad);
1790 gst_pad_set_pad_template (GstPad * pad, GstPadTemplate * templ)
1792 GstPadTemplate **template_p;
1794 /* this function would need checks if it weren't static */
1796 GST_OBJECT_LOCK (pad);
1797 template_p = &pad->padtemplate;
1798 gst_object_replace ((GstObject **) template_p, (GstObject *) templ);
1799 GST_OBJECT_UNLOCK (pad);
1802 gst_pad_template_pad_created (templ, pad);
1806 * gst_pad_get_pad_template:
1809 * Gets the template for @pad.
1811 * Returns: the #GstPadTemplate from which this pad was instantiated, or %NULL
1812 * if this pad has no template.
1814 * FIXME: currently returns an unrefcounted padtemplate.
1817 gst_pad_get_pad_template (GstPad * pad)
1819 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
1821 return GST_PAD_PAD_TEMPLATE (pad);
1825 /* should be called with the pad LOCK held */
1826 /* refs the caps, so caller is responsible for getting it unreffed */
1828 gst_pad_get_caps_unlocked (GstPad * pad)
1830 GstCaps *result = NULL;
1832 GST_CAT_DEBUG (GST_CAT_CAPS, "get pad caps of %s:%s (%p)",
1833 GST_DEBUG_PAD_NAME (pad), pad);
1835 if (GST_PAD_GETCAPSFUNC (pad)) {
1836 GST_CAT_DEBUG (GST_CAT_CAPS, "dispatching to pad getcaps function");
1838 GST_OBJECT_FLAG_SET (pad, GST_PAD_IN_GETCAPS);
1839 GST_OBJECT_UNLOCK (pad);
1840 result = GST_PAD_GETCAPSFUNC (pad) (pad);
1841 GST_OBJECT_LOCK (pad);
1842 GST_OBJECT_FLAG_UNSET (pad, GST_PAD_IN_GETCAPS);
1844 if (result == NULL) {
1845 g_critical ("pad %s:%s returned NULL caps from getcaps function",
1846 GST_DEBUG_PAD_NAME (pad));
1848 GST_CAT_DEBUG (GST_CAT_CAPS,
1849 "pad getcaps %s:%s returned %" GST_PTR_FORMAT,
1850 GST_DEBUG_PAD_NAME (pad), result);
1851 #ifndef G_DISABLE_ASSERT
1852 /* check that the returned caps are a real subset of the template caps */
1853 if (GST_PAD_PAD_TEMPLATE (pad)) {
1854 const GstCaps *templ_caps =
1855 GST_PAD_TEMPLATE_CAPS (GST_PAD_PAD_TEMPLATE (pad));
1856 if (!gst_caps_is_subset (result, templ_caps)) {
1859 GST_CAT_ERROR_OBJECT (GST_CAT_CAPS, pad,
1860 "pad returned caps %" GST_PTR_FORMAT
1861 " which are not a real subset of its template caps %"
1862 GST_PTR_FORMAT, result, templ_caps);
1864 ("pad %s:%s returned caps that are not a real subset of its template caps",
1865 GST_DEBUG_PAD_NAME (pad));
1866 temp = gst_caps_intersect (templ_caps, result);
1867 gst_caps_unref (result);
1875 if (GST_PAD_PAD_TEMPLATE (pad)) {
1876 GstPadTemplate *templ = GST_PAD_PAD_TEMPLATE (pad);
1878 result = GST_PAD_TEMPLATE_CAPS (templ);
1879 GST_CAT_DEBUG (GST_CAT_CAPS,
1880 "using pad template %p with caps %p %" GST_PTR_FORMAT, templ, result,
1883 result = gst_caps_ref (result);
1886 if (GST_PAD_CAPS (pad)) {
1887 result = GST_PAD_CAPS (pad);
1889 GST_CAT_DEBUG (GST_CAT_CAPS,
1890 "using pad caps %p %" GST_PTR_FORMAT, result, result);
1892 result = gst_caps_ref (result);
1896 GST_CAT_DEBUG (GST_CAT_CAPS, "pad has no caps");
1897 result = gst_caps_new_empty ();
1905 * @pad: a #GstPad to get the capabilities of.
1907 * Gets the capabilities this pad can produce or consume.
1908 * Note that this method doesn't necessarily return the caps set by
1909 * gst_pad_set_caps() - use #GST_PAD_CAPS for that instead.
1910 * gst_pad_get_caps returns all possible caps a pad can operate with, using
1911 * the pad's get_caps function;
1912 * this returns the pad template caps if not explicitly set.
1914 * Returns: a newly allocated copy of the #GstCaps of this pad.
1919 gst_pad_get_caps (GstPad * pad)
1921 GstCaps *result = NULL;
1923 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
1925 GST_OBJECT_LOCK (pad);
1927 GST_CAT_DEBUG (GST_CAT_CAPS, "get pad caps of %s:%s (%p)",
1928 GST_DEBUG_PAD_NAME (pad), pad);
1930 result = gst_pad_get_caps_unlocked (pad);
1931 GST_OBJECT_UNLOCK (pad);
1937 * gst_pad_peer_get_caps:
1938 * @pad: a #GstPad to get the peer capabilities of.
1940 * Gets the capabilities of the peer connected to this pad.
1942 * Returns: the #GstCaps of the peer pad. This function returns a new caps, so use
1943 * gst_caps_unref to get rid of it. this function returns NULL if there is no
1947 gst_pad_peer_get_caps (GstPad * pad)
1950 GstCaps *result = NULL;
1952 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
1954 GST_OBJECT_LOCK (pad);
1956 GST_CAT_DEBUG (GST_CAT_CAPS, "get peer caps of %s:%s (%p)",
1957 GST_DEBUG_PAD_NAME (pad), pad);
1959 peerpad = GST_PAD_PEER (pad);
1960 if (G_UNLIKELY (peerpad == NULL))
1963 gst_object_ref (peerpad);
1964 GST_OBJECT_UNLOCK (pad);
1966 result = gst_pad_get_caps (peerpad);
1968 gst_object_unref (peerpad);
1974 GST_OBJECT_UNLOCK (pad);
1980 fixate_value (GValue * dest, const GValue * src)
1982 if (G_VALUE_TYPE (src) == GST_TYPE_INT_RANGE) {
1983 g_value_init (dest, G_TYPE_INT);
1984 g_value_set_int (dest, gst_value_get_int_range_min (src));
1985 } else if (G_VALUE_TYPE (src) == GST_TYPE_DOUBLE_RANGE) {
1986 g_value_init (dest, G_TYPE_DOUBLE);
1987 g_value_set_double (dest, gst_value_get_double_range_min (src));
1988 } else if (G_VALUE_TYPE (src) == GST_TYPE_FRACTION_RANGE) {
1989 gst_value_init_and_copy (dest, gst_value_get_fraction_range_min (src));
1990 } else if (G_VALUE_TYPE (src) == GST_TYPE_LIST) {
1991 GValue temp = { 0 };
1993 gst_value_init_and_copy (&temp, gst_value_list_get_value (src, 0));
1994 if (!fixate_value (dest, &temp))
1995 gst_value_init_and_copy (dest, &temp);
1996 g_value_unset (&temp);
1997 } else if (G_VALUE_TYPE (src) == GST_TYPE_ARRAY) {
1998 gboolean res = FALSE;
2001 g_value_init (dest, GST_TYPE_ARRAY);
2002 for (n = 0; n < gst_value_array_get_size (src); n++) {
2004 const GValue *orig_kid = gst_value_array_get_value (src, n);
2006 if (!fixate_value (&kid, orig_kid))
2007 gst_value_init_and_copy (&kid, orig_kid);
2010 gst_value_array_append_value (dest, &kid);
2011 g_value_unset (&kid);
2015 g_value_unset (dest);
2026 gst_pad_default_fixate (GQuark field_id, const GValue * value, gpointer data)
2028 GstStructure *s = data;
2031 if (fixate_value (&v, value)) {
2032 gst_structure_id_set_value (s, field_id, &v);
2040 * gst_pad_fixate_caps:
2041 * @pad: a #GstPad to fixate
2042 * @caps: the #GstCaps to fixate
2044 * Fixate a caps on the given pad. Modifies the caps in place, so you should
2045 * make sure that the caps are actually writable (see gst_caps_make_writable()).
2048 gst_pad_fixate_caps (GstPad * pad, GstCaps * caps)
2050 GstPadFixateCapsFunction fixatefunc;
2053 g_return_if_fail (GST_IS_PAD (pad));
2054 g_return_if_fail (caps != NULL);
2056 if (gst_caps_is_fixed (caps))
2059 fixatefunc = GST_PAD_FIXATECAPSFUNC (pad);
2061 fixatefunc (pad, caps);
2064 /* default fixation */
2065 for (n = 0; n < gst_caps_get_size (caps); n++) {
2066 GstStructure *s = gst_caps_get_structure (caps, n);
2068 gst_structure_foreach (s, gst_pad_default_fixate, s);
2072 /* Default accept caps implementation just checks against
2073 * against the allowed caps for the pad */
2075 gst_pad_acceptcaps_default (GstPad * pad, GstCaps * caps)
2077 /* get the caps and see if it intersects to something
2081 gboolean result = FALSE;
2083 allowed = gst_pad_get_caps (pad);
2085 intersect = gst_caps_intersect (allowed, caps);
2087 result = !gst_caps_is_empty (intersect);
2089 gst_caps_unref (allowed);
2090 gst_caps_unref (intersect);
2097 * gst_pad_accept_caps:
2098 * @pad: a #GstPad to check
2099 * @caps: a #GstCaps to check on the pad
2101 * Check if the given pad accepts the caps.
2103 * Returns: TRUE if the pad can accept the caps.
2106 gst_pad_accept_caps (GstPad * pad, GstCaps * caps)
2109 GstPadAcceptCapsFunction acceptfunc;
2110 GstCaps *existing = NULL;
2112 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2114 /* any pad can be unnegotiated */
2118 GST_OBJECT_LOCK (pad);
2119 acceptfunc = GST_PAD_ACCEPTCAPSFUNC (pad);
2120 if (GST_PAD_CAPS (pad) != NULL)
2121 existing = gst_caps_ref (GST_PAD_CAPS (pad));
2123 GST_CAT_DEBUG (GST_CAT_CAPS, "pad accept caps of %s:%s (%p)",
2124 GST_DEBUG_PAD_NAME (pad), pad);
2125 GST_OBJECT_UNLOCK (pad);
2127 /* The current caps on a pad are trivially acceptable */
2129 if (caps == existing || gst_caps_is_equal (caps, existing))
2131 gst_caps_unref (existing);
2134 if (G_LIKELY (acceptfunc)) {
2135 /* we can call the function */
2136 result = acceptfunc (pad, caps);
2138 /* Only null if the element explicitly unset it */
2139 result = gst_pad_acceptcaps_default (pad, caps);
2144 gst_caps_unref (existing);
2149 * gst_pad_peer_accept_caps:
2150 * @pad: a #GstPad to check
2151 * @caps: a #GstCaps to check on the pad
2153 * Check if the given pad accepts the caps.
2155 * Returns: TRUE if the pad can accept the caps.
2158 gst_pad_peer_accept_caps (GstPad * pad, GstCaps * caps)
2163 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2165 GST_OBJECT_LOCK (pad);
2167 GST_CAT_DEBUG (GST_CAT_CAPS, "peer accept caps of %s:%s (%p)",
2168 GST_DEBUG_PAD_NAME (pad), pad);
2170 peerpad = GST_PAD_PEER (pad);
2171 if (G_UNLIKELY (peerpad == NULL))
2174 result = gst_pad_accept_caps (peerpad, caps);
2175 GST_OBJECT_UNLOCK (pad);
2181 GST_OBJECT_UNLOCK (pad);
2188 * @pad: a #GstPad to set the capabilities of.
2189 * @caps: a #GstCaps to set.
2191 * Sets the capabilities of this pad. The caps must be fixed. Any previous
2192 * caps on the pad will be unreffed. This function refs the caps so you should
2193 * unref if as soon as you don't need it anymore.
2194 * It is possible to set NULL caps, which will make the pad unnegotiated
2197 * Returns: TRUE if the caps could be set. FALSE if the caps were not fixed
2198 * or bad parameters were provided to this function.
2203 gst_pad_set_caps (GstPad * pad, GstCaps * caps)
2205 GstPadSetCapsFunction setcaps;
2208 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2209 g_return_val_if_fail (caps == NULL || gst_caps_is_fixed (caps), FALSE);
2211 GST_OBJECT_LOCK (pad);
2212 setcaps = GST_PAD_SETCAPSFUNC (pad);
2214 existing = GST_PAD_CAPS (pad);
2215 if (gst_caps_is_equal (caps, existing))
2216 goto setting_same_caps;
2218 /* call setcaps function to configure the pad only if the
2219 * caps is not NULL */
2220 if (setcaps != NULL && caps) {
2221 if (!GST_PAD_IS_IN_SETCAPS (pad)) {
2222 GST_OBJECT_FLAG_SET (pad, GST_PAD_IN_SETCAPS);
2223 GST_OBJECT_UNLOCK (pad);
2224 if (!setcaps (pad, caps))
2226 GST_OBJECT_LOCK (pad);
2227 GST_OBJECT_FLAG_UNSET (pad, GST_PAD_IN_SETCAPS);
2229 GST_CAT_DEBUG (GST_CAT_CAPS, "pad %s:%s was dispatching",
2230 GST_DEBUG_PAD_NAME (pad));
2234 gst_caps_replace (&GST_PAD_CAPS (pad), caps);
2235 GST_CAT_DEBUG (GST_CAT_CAPS, "%s:%s caps %" GST_PTR_FORMAT,
2236 GST_DEBUG_PAD_NAME (pad), caps);
2237 GST_OBJECT_UNLOCK (pad);
2239 g_object_notify (G_OBJECT (pad), "caps");
2245 gst_caps_replace (&GST_PAD_CAPS (pad), caps);
2246 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
2247 "caps %" GST_PTR_FORMAT " same as existing, updating ptr only", caps);
2248 GST_OBJECT_UNLOCK (pad);
2255 GST_OBJECT_LOCK (pad);
2256 GST_OBJECT_FLAG_UNSET (pad, GST_PAD_IN_SETCAPS);
2257 GST_CAT_DEBUG (GST_CAT_CAPS,
2258 "pad %s:%s, caps %" GST_PTR_FORMAT " could not be set",
2259 GST_DEBUG_PAD_NAME (pad), caps);
2260 GST_OBJECT_UNLOCK (pad);
2267 gst_pad_configure_sink (GstPad * pad, GstCaps * caps)
2269 GstPadAcceptCapsFunction acceptcaps;
2270 GstPadSetCapsFunction setcaps;
2273 acceptcaps = GST_PAD_ACCEPTCAPSFUNC (pad);
2274 setcaps = GST_PAD_SETCAPSFUNC (pad);
2276 /* See if pad accepts the caps - only needed if
2277 * no setcaps function */
2278 if (setcaps == NULL && acceptcaps != NULL)
2279 if (!acceptcaps (pad, caps))
2282 /* set caps on pad if call succeeds */
2283 res = gst_pad_set_caps (pad, caps);
2284 /* no need to unref the caps here, set_caps takes a ref and
2285 * our ref goes away when we leave this function. */
2291 GST_CAT_DEBUG (GST_CAT_CAPS, "caps %" GST_PTR_FORMAT " not accepted", caps);
2296 /* returns TRUE if the src pad could be configured to accept the given caps */
2298 gst_pad_configure_src (GstPad * pad, GstCaps * caps, gboolean dosetcaps)
2300 GstPadAcceptCapsFunction acceptcaps;
2301 GstPadSetCapsFunction setcaps;
2304 acceptcaps = GST_PAD_ACCEPTCAPSFUNC (pad);
2305 setcaps = GST_PAD_SETCAPSFUNC (pad);
2307 /* See if pad accepts the caps - only needed if
2308 * no setcaps function */
2309 if (setcaps == NULL && acceptcaps != NULL)
2310 if (!acceptcaps (pad, caps))
2314 res = gst_pad_set_caps (pad, caps);
2322 GST_CAT_DEBUG (GST_CAT_CAPS, "caps %" GST_PTR_FORMAT " not accepted", caps);
2328 * gst_pad_get_pad_template_caps:
2329 * @pad: a #GstPad to get the template capabilities from.
2331 * Gets the capabilities for @pad's template.
2333 * Returns: the #GstCaps of this pad template. If you intend to keep a reference
2334 * on the caps, make a copy (see gst_caps_copy ()).
2337 gst_pad_get_pad_template_caps (GstPad * pad)
2339 static GstStaticCaps anycaps = GST_STATIC_CAPS ("ANY");
2341 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2343 if (GST_PAD_PAD_TEMPLATE (pad))
2344 return GST_PAD_TEMPLATE_CAPS (GST_PAD_PAD_TEMPLATE (pad));
2346 return gst_static_caps_get (&anycaps);
2352 * @pad: a #GstPad to get the peer of.
2354 * Gets the peer of @pad. This function refs the peer pad so
2355 * you need to unref it after use.
2357 * Returns: the peer #GstPad. Unref after usage.
2362 gst_pad_get_peer (GstPad * pad)
2366 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2368 GST_OBJECT_LOCK (pad);
2369 result = GST_PAD_PEER (pad);
2371 gst_object_ref (result);
2372 GST_OBJECT_UNLOCK (pad);
2378 * gst_pad_get_allowed_caps:
2379 * @srcpad: a #GstPad, it must a a source pad.
2381 * Gets the capabilities of the allowed media types that can flow through
2382 * @srcpad and its peer. The pad must be a source pad.
2383 * The caller must free the resulting caps.
2385 * Returns: the allowed #GstCaps of the pad link. Free the caps when
2386 * you no longer need it. This function returns NULL when the @srcpad has no
2392 gst_pad_get_allowed_caps (GstPad * srcpad)
2399 g_return_val_if_fail (GST_IS_PAD (srcpad), NULL);
2400 g_return_val_if_fail (GST_PAD_IS_SRC (srcpad), NULL);
2402 GST_OBJECT_LOCK (srcpad);
2404 peer = GST_PAD_PEER (srcpad);
2405 if (G_UNLIKELY (peer == NULL))
2408 GST_CAT_DEBUG (GST_CAT_PROPERTIES, "%s:%s: getting allowed caps",
2409 GST_DEBUG_PAD_NAME (srcpad));
2411 gst_object_ref (peer);
2412 GST_OBJECT_UNLOCK (srcpad);
2413 mycaps = gst_pad_get_caps (srcpad);
2415 peercaps = gst_pad_get_caps (peer);
2416 gst_object_unref (peer);
2418 caps = gst_caps_intersect (mycaps, peercaps);
2419 gst_caps_unref (peercaps);
2420 gst_caps_unref (mycaps);
2422 GST_CAT_DEBUG (GST_CAT_CAPS, "allowed caps %" GST_PTR_FORMAT, caps);
2428 GST_CAT_DEBUG (GST_CAT_PROPERTIES, "%s:%s: no peer",
2429 GST_DEBUG_PAD_NAME (srcpad));
2430 GST_OBJECT_UNLOCK (srcpad);
2437 * gst_pad_get_negotiated_caps:
2440 * Gets the capabilities of the media type that currently flows through @pad
2443 * This function can be used on both src and sinkpads. Note that srcpads are
2444 * always negotiated before sinkpads so it is possible that the negotiated caps
2445 * on the srcpad do not match the negotiated caps of the peer.
2447 * Returns: the negotiated #GstCaps of the pad link. Free the caps when
2448 * you no longer need it. This function returns NULL when the @pad has no
2449 * peer or is not negotiated yet.
2454 gst_pad_get_negotiated_caps (GstPad * pad)
2459 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2461 GST_OBJECT_LOCK (pad);
2463 if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
2466 GST_CAT_DEBUG (GST_CAT_PROPERTIES, "%s:%s: getting negotiated caps",
2467 GST_DEBUG_PAD_NAME (pad));
2469 caps = GST_PAD_CAPS (pad);
2471 gst_caps_ref (caps);
2472 GST_OBJECT_UNLOCK (pad);
2474 GST_CAT_DEBUG (GST_CAT_CAPS, "negotiated caps %" GST_PTR_FORMAT, caps);
2480 GST_CAT_DEBUG (GST_CAT_PROPERTIES, "%s:%s: no peer",
2481 GST_DEBUG_PAD_NAME (pad));
2482 GST_OBJECT_UNLOCK (pad);
2488 static GstFlowReturn
2489 gst_pad_alloc_buffer_full (GstPad * pad, guint64 offset, gint size,
2490 GstCaps * caps, GstBuffer ** buf, gboolean setcaps)
2494 GstPadBufferAllocFunction bufferallocfunc;
2495 gboolean caps_changed;
2497 g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
2498 g_return_val_if_fail (GST_PAD_IS_SRC (pad), GST_FLOW_ERROR);
2499 g_return_val_if_fail (buf != NULL, GST_FLOW_ERROR);
2501 GST_OBJECT_LOCK (pad);
2502 while (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad)))
2503 if ((ret = handle_pad_block (pad)) != GST_FLOW_OK)
2506 if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
2509 gst_object_ref (peer);
2510 GST_OBJECT_UNLOCK (pad);
2512 if (G_LIKELY ((bufferallocfunc = peer->bufferallocfunc) == NULL))
2515 GST_OBJECT_LOCK (peer);
2516 /* when the peer is flushing we cannot give a buffer */
2517 if (G_UNLIKELY (GST_PAD_IS_FLUSHING (peer)))
2520 if (offset == GST_BUFFER_OFFSET_NONE) {
2521 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
2522 "calling bufferallocfunc &%s (@%p) of peer pad %s:%s for size %d offset NONE",
2523 GST_DEBUG_FUNCPTR_NAME (bufferallocfunc),
2524 &bufferallocfunc, GST_DEBUG_PAD_NAME (peer), size);
2526 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
2527 "calling bufferallocfunc &%s (@%p) of peer pad %s:%s for size %d offset %"
2528 G_GUINT64_FORMAT, GST_DEBUG_FUNCPTR_NAME (bufferallocfunc),
2529 &bufferallocfunc, GST_DEBUG_PAD_NAME (peer), size, offset);
2531 GST_OBJECT_UNLOCK (peer);
2533 ret = bufferallocfunc (peer, offset, size, caps, buf);
2535 if (G_UNLIKELY (ret != GST_FLOW_OK))
2537 if (G_UNLIKELY (*buf == NULL))
2540 /* If the buffer alloc function didn't set up the caps like it should,
2542 if (caps && (GST_BUFFER_CAPS (*buf) == NULL)) {
2543 GST_WARNING ("Buffer allocation function for pad % " GST_PTR_FORMAT
2544 " did not set up caps. Setting", peer);
2546 gst_buffer_set_caps (*buf, caps);
2550 gst_object_unref (peer);
2552 /* FIXME, move capnego this into a base class? */
2553 caps = GST_BUFFER_CAPS (*buf);
2554 caps_changed = caps && caps != GST_PAD_CAPS (pad);
2555 /* we got a new datatype on the pad, see if it can handle it */
2556 if (G_UNLIKELY (caps_changed)) {
2557 GST_DEBUG_OBJECT (pad, "caps changed to %" GST_PTR_FORMAT, caps);
2558 if (G_UNLIKELY (!gst_pad_configure_src (pad, caps, setcaps)))
2559 goto not_negotiated;
2565 GST_CAT_DEBUG (GST_CAT_PADS, "%s:%s pad block stopped by flush",
2566 GST_DEBUG_PAD_NAME (pad));
2567 GST_OBJECT_UNLOCK (pad);
2572 /* pad has no peer */
2573 GST_CAT_DEBUG (GST_CAT_PADS,
2574 "%s:%s called bufferallocfunc but had no peer",
2575 GST_DEBUG_PAD_NAME (pad));
2576 GST_OBJECT_UNLOCK (pad);
2577 return GST_FLOW_NOT_LINKED;
2581 /* peer was flushing */
2582 GST_OBJECT_UNLOCK (peer);
2583 gst_object_unref (peer);
2584 GST_CAT_DEBUG (GST_CAT_PADS,
2585 "%s:%s called bufferallocfunc but peer was flushing",
2586 GST_DEBUG_PAD_NAME (pad));
2587 return GST_FLOW_WRONG_STATE;
2589 /* fallback case, allocate a buffer of our own, add pad caps. */
2592 GST_CAT_DEBUG (GST_CAT_PADS,
2593 "%s:%s fallback buffer alloc", GST_DEBUG_PAD_NAME (pad));
2594 *buf = gst_buffer_new_and_alloc (size);
2595 GST_BUFFER_OFFSET (*buf) = offset;
2596 gst_buffer_set_caps (*buf, caps);
2604 gst_buffer_unref (*buf);
2606 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
2607 "alloc function returned unacceptable buffer");
2608 return GST_FLOW_NOT_NEGOTIATED;
2612 gst_object_unref (peer);
2613 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
2614 "alloc function returned error %s", gst_flow_get_name (ret));
2620 * gst_pad_alloc_buffer:
2621 * @pad: a source #GstPad
2622 * @offset: the offset of the new buffer in the stream
2623 * @size: the size of the new buffer
2624 * @caps: the caps of the new buffer
2625 * @buf: a newly allocated buffer
2627 * Allocates a new, empty buffer optimized to push to pad @pad. This
2628 * function only works if @pad is a source pad and has a peer.
2630 * You need to check the caps of the buffer after performing this
2631 * function and renegotiate to the format if needed.
2633 * A new, empty #GstBuffer will be put in the @buf argument.
2635 * Returns: a result code indicating success of the operation. Any
2636 * result code other than GST_FLOW_OK is an error and @buf should
2638 * An error can occur if the pad is not connected or when the downstream
2639 * peer elements cannot provide an acceptable buffer.
2644 gst_pad_alloc_buffer (GstPad * pad, guint64 offset, gint size, GstCaps * caps,
2647 return gst_pad_alloc_buffer_full (pad, offset, size, caps, buf, FALSE);
2651 * gst_pad_alloc_buffer_and_set_caps:
2652 * @pad: a source #GstPad
2653 * @offset: the offset of the new buffer in the stream
2654 * @size: the size of the new buffer
2655 * @caps: the caps of the new buffer
2656 * @buf: a newly allocated buffer
2658 * In addition to the function gst_pad_alloc_buffer(), this function
2659 * automatically calls gst_pad_set_caps() when the caps of the
2660 * newly allocated buffer are different from the @pad caps.
2662 * Returns: a result code indicating success of the operation. Any
2663 * result code other than GST_FLOW_OK is an error and @buf should
2665 * An error can occur if the pad is not connected or when the downstream
2666 * peer elements cannot provide an acceptable buffer.
2671 gst_pad_alloc_buffer_and_set_caps (GstPad * pad, guint64 offset, gint size,
2672 GstCaps * caps, GstBuffer ** buf)
2674 return gst_pad_alloc_buffer_full (pad, offset, size, caps, buf, TRUE);
2678 * gst_pad_get_internal_links_default:
2679 * @pad: the #GstPad to get the internal links of.
2681 * Gets a list of pads to which the given pad is linked to
2682 * inside of the parent element.
2683 * This is the default handler, and thus returns a list of all of the
2684 * pads inside the parent element with opposite direction.
2685 * The caller must free this list after use.
2687 * Returns: a newly allocated #GList of pads, or NULL if the pad has no parent.
2692 gst_pad_get_internal_links_default (GstPad * pad)
2697 GstPadDirection direction;
2699 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2701 direction = pad->direction;
2703 parent = GST_PAD_PARENT (pad);
2707 parent_pads = parent->pads;
2709 while (parent_pads) {
2710 GstPad *parent_pad = GST_PAD_CAST (parent_pads->data);
2712 if (parent_pad->direction != direction) {
2713 res = g_list_prepend (res, parent_pad);
2716 parent_pads = g_list_next (parent_pads);
2723 * gst_pad_get_internal_links:
2724 * @pad: the #GstPad to get the internal links of.
2726 * Gets a list of pads to which the given pad is linked to
2727 * inside of the parent element.
2728 * The caller must free this list after use.
2730 * Returns: a newly allocated #GList of pads.
2735 gst_pad_get_internal_links (GstPad * pad)
2739 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2741 if (GST_PAD_INTLINKFUNC (pad))
2742 res = GST_PAD_INTLINKFUNC (pad) (pad);
2749 gst_pad_event_default_dispatch (GstPad * pad, GstEvent * event)
2754 GST_INFO_OBJECT (pad, "Sending event %p to all internally linked pads",
2757 result = (GST_PAD_DIRECTION (pad) == GST_PAD_SINK);
2759 orig = pads = gst_pad_get_internal_links (pad);
2762 GstPad *eventpad = GST_PAD_CAST (pads->data);
2764 pads = g_list_next (pads);
2766 if (GST_PAD_DIRECTION (eventpad) == GST_PAD_SRC) {
2767 /* for each pad we send to, we should ref the event; it's up
2768 * to downstream to unref again when handled. */
2769 GST_LOG_OBJECT (pad, "Reffing and sending event %p (%s) to %s:%s",
2770 event, GST_EVENT_TYPE_NAME (event), GST_DEBUG_PAD_NAME (eventpad));
2771 gst_event_ref (event);
2772 gst_pad_push_event (eventpad, event);
2774 /* we only send the event on one pad, multi-sinkpad elements
2775 * should implement a handler */
2776 GST_LOG_OBJECT (pad, "sending event %p (%s) to one sink pad %s:%s",
2777 event, GST_EVENT_TYPE_NAME (event), GST_DEBUG_PAD_NAME (eventpad));
2778 result = gst_pad_push_event (eventpad, event);
2782 /* we handled the incoming event so we unref once */
2783 GST_LOG_OBJECT (pad, "handled event %p, unreffing", event);
2784 gst_event_unref (event);
2793 * gst_pad_event_default:
2794 * @pad: a #GstPad to call the default event handler on.
2795 * @event: the #GstEvent to handle.
2797 * Invokes the default event handler for the given pad. End-of-stream and
2798 * discontinuity events are handled specially, and then the event is sent to all
2799 * pads internally linked to @pad. Note that if there are many possible sink
2800 * pads that are internally linked to @pad, only one will be sent an event.
2801 * Multi-sinkpad elements should implement custom event handlers.
2803 * Returns: TRUE if the event was sent succesfully.
2806 gst_pad_event_default (GstPad * pad, GstEvent * event)
2808 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2809 g_return_val_if_fail (event != NULL, FALSE);
2811 switch (GST_EVENT_TYPE (event)) {
2814 GST_DEBUG_OBJECT (pad, "pausing task because of eos");
2815 gst_pad_pause_task (pad);
2821 return gst_pad_event_default_dispatch (pad, event);
2825 * gst_pad_dispatcher:
2826 * @pad: a #GstPad to dispatch.
2827 * @dispatch: the #GstDispatcherFunction to call.
2828 * @data: gpointer user data passed to the dispatcher function.
2830 * Invokes the given dispatcher function on all pads that are
2831 * internally linked to the given pad.
2832 * The GstPadDispatcherFunction should return TRUE when no further pads
2833 * need to be processed.
2835 * Returns: TRUE if one of the dispatcher functions returned TRUE.
2838 gst_pad_dispatcher (GstPad * pad, GstPadDispatcherFunction dispatch,
2841 gboolean res = FALSE;
2842 GList *int_pads, *orig;
2844 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2845 g_return_val_if_fail (dispatch != NULL, FALSE);
2847 orig = int_pads = gst_pad_get_internal_links (pad);
2850 GstPad *int_pad = GST_PAD_CAST (int_pads->data);
2851 GstPad *int_peer = GST_PAD_PEER (int_pad);
2854 res = dispatch (int_peer, data);
2858 int_pads = g_list_next (int_pads);
2868 * @pad: a #GstPad to invoke the default query on.
2869 * @query: the #GstQuery to perform.
2871 * Dispatches a query to a pad. The query should have been allocated by the
2872 * caller via one of the type-specific allocation functions in gstquery.h. The
2873 * element is responsible for filling the query with an appropriate response,
2874 * which should then be parsed with a type-specific query parsing function.
2876 * Again, the caller is responsible for both the allocation and deallocation of
2877 * the query structure.
2879 * Returns: TRUE if the query could be performed.
2882 gst_pad_query (GstPad * pad, GstQuery * query)
2884 GstPadQueryFunction func;
2886 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2887 g_return_val_if_fail (GST_IS_QUERY (query), FALSE);
2889 GST_DEBUG ("sending query %p to pad %s:%s", query, GST_DEBUG_PAD_NAME (pad));
2891 if ((func = GST_PAD_QUERYFUNC (pad)) == NULL)
2894 return func (pad, query);
2898 GST_DEBUG ("pad had no query function");
2904 * gst_pad_query_default:
2905 * @pad: a #GstPad to call the default query handler on.
2906 * @query: the #GstQuery to handle.
2908 * Invokes the default query handler for the given pad.
2909 * The query is sent to all pads internally linked to @pad. Note that
2910 * if there are many possible sink pads that are internally linked to
2911 * @pad, only one will be sent the query.
2912 * Multi-sinkpad elements should implement custom query handlers.
2914 * Returns: TRUE if the query was performed succesfully.
2917 gst_pad_query_default (GstPad * pad, GstQuery * query)
2919 switch (GST_QUERY_TYPE (query)) {
2920 case GST_QUERY_POSITION:
2921 case GST_QUERY_SEEKING:
2922 case GST_QUERY_FORMATS:
2923 case GST_QUERY_LATENCY:
2924 case GST_QUERY_JITTER:
2925 case GST_QUERY_RATE:
2926 case GST_QUERY_CONVERT:
2928 return gst_pad_dispatcher
2929 (pad, (GstPadDispatcherFunction) gst_pad_query, query);
2933 #ifndef GST_DISABLE_LOADSAVE
2934 /* FIXME: why isn't this on a GstElement ? */
2936 * gst_pad_load_and_link:
2937 * @self: an #xmlNodePtr to read the description from.
2938 * @parent: the #GstObject element that owns the pad.
2940 * Reads the pad definition from the XML node and links the given pad
2941 * in the element to a pad of an element up in the hierarchy.
2944 gst_pad_load_and_link (xmlNodePtr self, GstObject * parent)
2946 xmlNodePtr field = self->xmlChildrenNode;
2947 GstPad *pad = NULL, *targetpad;
2951 GstObject *grandparent;
2955 if (!strcmp ((char *) field->name, "name")) {
2956 name = (gchar *) xmlNodeGetContent (field);
2957 pad = gst_element_get_pad (GST_ELEMENT (parent), name);
2959 } else if (!strcmp ((char *) field->name, "peer")) {
2960 peer = (gchar *) xmlNodeGetContent (field);
2962 field = field->next;
2964 g_return_if_fail (pad != NULL);
2969 split = g_strsplit (peer, ".", 2);
2971 if (split[0] == NULL || split[1] == NULL) {
2972 GST_CAT_DEBUG (GST_CAT_XML,
2973 "Could not parse peer '%s' for pad %s:%s, leaving unlinked",
2974 peer, GST_DEBUG_PAD_NAME (pad));
2981 g_return_if_fail (split[0] != NULL);
2982 g_return_if_fail (split[1] != NULL);
2984 grandparent = gst_object_get_parent (parent);
2986 if (grandparent && GST_IS_BIN (grandparent)) {
2987 target = gst_bin_get_by_name_recurse_up (GST_BIN (grandparent), split[0]);
2994 targetpad = gst_element_get_pad (target, split[1]);
2996 if (targetpad == NULL)
2999 gst_pad_link (pad, targetpad);
3006 * gst_pad_save_thyself:
3007 * @pad: a #GstPad to save.
3008 * @parent: the parent #xmlNodePtr to save the description in.
3010 * Saves the pad into an xml representation.
3012 * Returns: the #xmlNodePtr representation of the pad.
3015 gst_pad_save_thyself (GstObject * object, xmlNodePtr parent)
3020 g_return_val_if_fail (GST_IS_PAD (object), NULL);
3022 pad = GST_PAD (object);
3024 xmlNewChild (parent, NULL, (xmlChar *) "name",
3025 (xmlChar *) GST_PAD_NAME (pad));
3026 if (GST_PAD_PEER (pad) != NULL) {
3029 peer = GST_PAD_PEER (pad);
3030 /* first check to see if the peer's parent's parent is the same */
3031 /* we just save it off */
3032 content = g_strdup_printf ("%s.%s",
3033 GST_OBJECT_NAME (GST_PAD_PARENT (peer)), GST_PAD_NAME (peer));
3034 xmlNewChild (parent, NULL, (xmlChar *) "peer", (xmlChar *) content);
3037 xmlNewChild (parent, NULL, (xmlChar *) "peer", NULL);
3044 * gst_ghost_pad_save_thyself:
3045 * @pad: a ghost #GstPad to save.
3046 * @parent: the parent #xmlNodePtr to save the description in.
3048 * Saves the ghost pad into an xml representation.
3050 * Returns: the #xmlNodePtr representation of the pad.
3053 gst_ghost_pad_save_thyself (GstPad * pad, xmlNodePtr parent)
3057 g_return_val_if_fail (GST_IS_GHOST_PAD (pad), NULL);
3059 self = xmlNewChild (parent, NULL, (xmlChar *) "ghostpad", NULL);
3060 xmlNewChild (self, NULL, (xmlChar *) "name", (xmlChar *) GST_PAD_NAME (pad));
3061 xmlNewChild (self, NULL, (xmlChar *) "parent",
3062 (xmlChar *) GST_OBJECT_NAME (GST_PAD_PARENT (pad)));
3064 /* FIXME FIXME FIXME! */
3069 #endif /* GST_DISABLE_LOADSAVE */
3072 * should be called with pad lock held
3076 static GstFlowReturn
3077 handle_pad_block (GstPad * pad)
3079 GstPadBlockCallback callback;
3081 GstFlowReturn ret = GST_FLOW_OK;
3083 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3084 "signal block taken on pad %s:%s", GST_DEBUG_PAD_NAME (pad));
3086 /* need to grab extra ref for the callbacks */
3087 gst_object_ref (pad);
3089 callback = pad->block_callback;
3091 user_data = pad->block_data;
3092 GST_OBJECT_UNLOCK (pad);
3093 callback (pad, TRUE, user_data);
3094 GST_OBJECT_LOCK (pad);
3096 GST_PAD_BLOCK_SIGNAL (pad);
3099 while (GST_PAD_IS_BLOCKED (pad)) {
3100 if (GST_PAD_IS_FLUSHING (pad))
3102 GST_PAD_BLOCK_WAIT (pad);
3103 if (GST_PAD_IS_FLUSHING (pad))
3107 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "got unblocked");
3109 callback = pad->block_callback;
3111 user_data = pad->block_data;
3112 GST_OBJECT_UNLOCK (pad);
3113 callback (pad, FALSE, user_data);
3114 GST_OBJECT_LOCK (pad);
3116 GST_PAD_BLOCK_SIGNAL (pad);
3119 gst_object_unref (pad);
3125 gst_object_unref (pad);
3126 return GST_FLOW_WRONG_STATE;
3130 /**********************************************************************
3131 * Data passing functions
3135 gst_pad_emit_have_data_signal (GstPad * pad, GstMiniObject * obj)
3138 GValue args[2] = { {0}, {0} };
3143 g_value_init (&ret, G_TYPE_BOOLEAN);
3144 g_value_set_boolean (&ret, TRUE);
3145 g_value_init (&args[0], GST_TYPE_PAD);
3146 g_value_set_object (&args[0], pad);
3147 g_value_init (&args[1], GST_TYPE_MINI_OBJECT); // G_TYPE_POINTER);
3148 gst_value_set_mini_object (&args[1], obj);
3150 if (GST_IS_EVENT (obj))
3151 detail = event_quark;
3153 detail = buffer_quark;
3156 g_signal_emitv (args, gst_pad_signals[PAD_HAVE_DATA], detail, &ret);
3157 res = g_value_get_boolean (&ret);
3160 g_value_unset (&ret);
3161 g_value_unset (&args[0]);
3162 g_value_unset (&args[1]);
3169 * @pad: a sink #GstPad.
3170 * @buffer: the #GstBuffer to send.
3172 * Chain a buffer to @pad.
3174 * Returns: a #GstFlowReturn from the pad.
3179 gst_pad_chain (GstPad * pad, GstBuffer * buffer)
3182 gboolean caps_changed;
3183 GstPadChainFunction chainfunc;
3185 gboolean emit_signal;
3187 g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
3188 g_return_val_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SINK,
3190 g_return_val_if_fail (buffer != NULL, GST_FLOW_ERROR);
3191 g_return_val_if_fail (GST_IS_BUFFER (buffer), GST_FLOW_ERROR);
3193 GST_PAD_STREAM_LOCK (pad);
3195 GST_OBJECT_LOCK (pad);
3196 if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad)))
3199 caps = GST_BUFFER_CAPS (buffer);
3200 caps_changed = caps && caps != GST_PAD_CAPS (pad);
3202 emit_signal = GST_PAD_DO_BUFFER_SIGNALS (pad) > 0;
3203 GST_OBJECT_UNLOCK (pad);
3205 /* see if the signal should be emited, we emit before caps nego as
3206 * we might drop the buffer and do capsnego for nothing. */
3207 if (G_UNLIKELY (emit_signal)) {
3208 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (buffer)))
3212 /* we got a new datatype on the pad, see if it can handle it */
3213 if (G_UNLIKELY (caps_changed)) {
3214 GST_DEBUG_OBJECT (pad, "caps changed to %" GST_PTR_FORMAT, caps);
3215 if (G_UNLIKELY (!gst_pad_configure_sink (pad, caps)))
3216 goto not_negotiated;
3219 /* NOTE: we read the chainfunc unlocked.
3220 * we cannot hold the lock for the pad so we might send
3221 * the data to the wrong function. This is not really a
3222 * problem since functions are assigned at creation time
3223 * and don't change that often... */
3224 if (G_UNLIKELY ((chainfunc = GST_PAD_CHAINFUNC (pad)) == NULL))
3227 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3228 "calling chainfunction &%s of pad %s:%s",
3229 GST_DEBUG_FUNCPTR_NAME (chainfunc), GST_DEBUG_PAD_NAME (pad));
3231 ret = chainfunc (pad, buffer);
3233 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3234 "called chainfunction &%s of pad %s:%s, returned %s",
3235 GST_DEBUG_FUNCPTR_NAME (chainfunc), GST_DEBUG_PAD_NAME (pad),
3236 gst_flow_get_name (ret));
3238 GST_PAD_STREAM_UNLOCK (pad);
3245 gst_buffer_unref (buffer);
3246 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3247 "pushing, but pad was flushing");
3248 GST_OBJECT_UNLOCK (pad);
3249 GST_PAD_STREAM_UNLOCK (pad);
3250 return GST_FLOW_WRONG_STATE;
3254 gst_buffer_unref (buffer);
3255 GST_DEBUG_OBJECT (pad, "Dropping buffer due to FALSE probe return");
3256 GST_PAD_STREAM_UNLOCK (pad);
3261 gst_buffer_unref (buffer);
3262 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3263 "pushing buffer but pad did not accept");
3264 GST_PAD_STREAM_UNLOCK (pad);
3265 return GST_FLOW_NOT_NEGOTIATED;
3269 gst_buffer_unref (buffer);
3270 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3271 "pushing, but not chainhandler");
3272 GST_ELEMENT_ERROR (GST_PAD_PARENT (pad), CORE, PAD, (NULL),
3273 ("push on pad %s:%s but it has no chainfunction",
3274 GST_DEBUG_PAD_NAME (pad)));
3275 GST_PAD_STREAM_UNLOCK (pad);
3276 return GST_FLOW_ERROR;
3282 * @pad: a source #GstPad.
3283 * @buffer: the #GstBuffer to push.
3285 * Pushes a buffer to the peer of @pad. This gives away your reference to
3287 * Buffer probes will be triggered before the buffer gets pushed.
3289 * Returns: a #GstFlowReturn from the peer pad.
3294 gst_pad_push (GstPad * pad, GstBuffer * buffer)
3301 gboolean caps_changed;
3304 g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
3305 g_return_val_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SRC, GST_FLOW_ERROR);
3306 g_return_val_if_fail (buffer != NULL, GST_FLOW_ERROR);
3307 g_return_val_if_fail (GST_IS_BUFFER (buffer), GST_FLOW_ERROR);
3309 GST_OBJECT_LOCK (pad);
3311 /* FIXME: this check can go away; pad_set_blocked could be implemented with
3312 * probes completely */
3313 while (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad)))
3314 if ((ret = handle_pad_block (pad)) != GST_FLOW_OK)
3317 /* we emit signals on the pad arg, the peer will have a chance to
3318 * emit in the _chain() function */
3319 if (G_UNLIKELY (GST_PAD_DO_BUFFER_SIGNALS (pad) > 0)) {
3320 /* unlock before emitting */
3321 GST_OBJECT_UNLOCK (pad);
3323 /* if the signal handler returned FALSE, it means we should just drop the
3325 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (buffer)))
3328 GST_OBJECT_LOCK (pad);
3331 if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
3333 gst_object_ref (peer);
3336 /* FIXME, disabled for 0.10.5 release because it caused to much
3338 /* Before pushing the buffer to the peer pad, ensure that caps
3339 * are set on this pad */
3340 caps = GST_BUFFER_CAPS (buffer);
3341 caps_changed = caps && caps != GST_PAD_CAPS (pad);
3344 GST_OBJECT_UNLOCK (pad);
3347 /* we got a new datatype from the pad, it had better handle it */
3348 if (G_UNLIKELY (caps_changed)) {
3349 GST_DEBUG_OBJECT (pad, "caps changed to %" GST_PTR_FORMAT, caps);
3350 if (G_UNLIKELY (!gst_pad_configure_src (pad, caps, TRUE)))
3351 goto not_negotiated;
3355 ret = gst_pad_chain (peer, buffer);
3357 gst_object_unref (peer);
3361 /* ERROR recovery here */
3364 gst_buffer_unref (buffer);
3365 GST_DEBUG_OBJECT (pad, "pad block stopped by flush");
3366 GST_OBJECT_UNLOCK (pad);
3371 gst_buffer_unref (buffer);
3372 GST_DEBUG_OBJECT (pad, "Dropping buffer due to FALSE probe return");
3377 gst_buffer_unref (buffer);
3378 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3379 "pushing, but it was not linked");
3380 GST_OBJECT_UNLOCK (pad);
3381 return GST_FLOW_NOT_LINKED;
3386 gst_buffer_unref (buffer);
3387 gst_object_unref (peer);
3388 GST_CAT_DEBUG_OBJECT (GST_CAT_SCHEDULING, pad,
3389 "element pushed buffer then refused to accept the caps");
3390 return GST_FLOW_NOT_NEGOTIATED;
3396 * gst_pad_check_pull_range:
3397 * @pad: a sink #GstPad.
3399 * Checks if a gst_pad_pull_range() can be performed on the peer
3400 * source pad. This function is used by plugins that want to check
3401 * if they can use random access on the peer source pad.
3403 * The peer sourcepad can implement a custom #GstPadCheckGetRangeFunction
3404 * if it needs to perform some logic to determine if pull_range is
3407 * Returns: a gboolean with the result.
3412 gst_pad_check_pull_range (GstPad * pad)
3416 GstPadCheckGetRangeFunction checkgetrangefunc;
3418 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
3420 GST_OBJECT_LOCK (pad);
3421 if (GST_PAD_DIRECTION (pad) != GST_PAD_SINK)
3422 goto wrong_direction;
3424 if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
3427 gst_object_ref (peer);
3428 GST_OBJECT_UNLOCK (pad);
3430 /* see note in above function */
3431 if (G_LIKELY ((checkgetrangefunc = peer->checkgetrangefunc) == NULL)) {
3432 /* FIXME, kindoff ghetto */
3433 ret = GST_PAD_GETRANGEFUNC (peer) != NULL;
3435 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3436 "calling checkgetrangefunc %s of peer pad %s:%s",
3437 GST_DEBUG_FUNCPTR_NAME (checkgetrangefunc), GST_DEBUG_PAD_NAME (peer));
3439 ret = checkgetrangefunc (peer);
3442 gst_object_unref (peer);
3446 /* ERROR recovery here */
3449 GST_OBJECT_UNLOCK (pad);
3454 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3455 "checking pull range, but it was not linked");
3456 GST_OBJECT_UNLOCK (pad);
3462 * gst_pad_get_range:
3463 * @pad: a src #GstPad.
3464 * @offset: The start offset of the buffer
3465 * @size: The length of the buffer
3466 * @buffer: a pointer to hold the #GstBuffer.
3468 * Calls the getrange function of @pad.
3470 * Returns: a #GstFlowReturn from the pad.
3475 gst_pad_get_range (GstPad * pad, guint64 offset, guint size,
3476 GstBuffer ** buffer)
3479 GstPadGetRangeFunction getrangefunc;
3480 gboolean emit_signal;
3482 g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
3483 g_return_val_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SRC, GST_FLOW_ERROR);
3484 g_return_val_if_fail (buffer != NULL, GST_FLOW_ERROR);
3486 GST_PAD_STREAM_LOCK (pad);
3488 GST_OBJECT_LOCK (pad);
3489 if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad)))
3492 emit_signal = GST_PAD_DO_BUFFER_SIGNALS (pad) > 0;
3493 GST_OBJECT_UNLOCK (pad);
3495 if (G_UNLIKELY ((getrangefunc = GST_PAD_GETRANGEFUNC (pad)) == NULL))
3498 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3499 "calling getrangefunc %s of peer pad %s:%s, offset %"
3500 G_GUINT64_FORMAT ", size %u",
3501 GST_DEBUG_FUNCPTR_NAME (getrangefunc), GST_DEBUG_PAD_NAME (pad),
3504 ret = getrangefunc (pad, offset, size, buffer);
3506 /* can only fire the signal if we have a valid buffer */
3507 if (G_UNLIKELY (emit_signal) && (ret == GST_FLOW_OK)) {
3508 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (*buffer)))
3512 GST_PAD_STREAM_UNLOCK (pad);
3519 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3520 "pulling range, but pad was flushing");
3521 GST_OBJECT_UNLOCK (pad);
3522 GST_PAD_STREAM_UNLOCK (pad);
3523 return GST_FLOW_WRONG_STATE;
3527 GST_ELEMENT_ERROR (GST_PAD_PARENT (pad), CORE, PAD, (NULL),
3528 ("pullrange on pad %s:%s but it has no getrangefunction",
3529 GST_DEBUG_PAD_NAME (pad)));
3530 GST_PAD_STREAM_UNLOCK (pad);
3531 return GST_FLOW_ERROR;
3535 GST_DEBUG ("Dropping data after FALSE probe return");
3536 GST_PAD_STREAM_UNLOCK (pad);
3537 gst_buffer_unref (*buffer);
3539 return GST_FLOW_UNEXPECTED;
3545 * gst_pad_pull_range:
3546 * @pad: a sink #GstPad.
3547 * @offset: The start offset of the buffer
3548 * @size: The length of the buffer
3549 * @buffer: a pointer to hold the #GstBuffer.
3551 * Pulls a buffer from the peer pad. @pad must be a linked
3554 * Returns: a #GstFlowReturn from the peer pad.
3559 gst_pad_pull_range (GstPad * pad, guint64 offset, guint size,
3560 GstBuffer ** buffer)
3564 gboolean emit_signal;
3566 g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
3567 g_return_val_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SINK,
3569 g_return_val_if_fail (buffer != NULL, GST_FLOW_ERROR);
3571 GST_OBJECT_LOCK (pad);
3573 while (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad)))
3574 handle_pad_block (pad);
3576 if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
3579 /* signal emision for the pad, peer has chance to emit when
3580 * we call _get_range() */
3581 emit_signal = GST_PAD_DO_BUFFER_SIGNALS (pad) > 0;
3583 gst_object_ref (peer);
3584 GST_OBJECT_UNLOCK (pad);
3586 ret = gst_pad_get_range (peer, offset, size, buffer);
3588 gst_object_unref (peer);
3590 /* can only fire the signal if we have a valid buffer */
3591 if (G_UNLIKELY (emit_signal) && (ret == GST_FLOW_OK)) {
3592 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (*buffer)))
3597 /* ERROR recovery here */
3600 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3601 "pulling range, but it was not linked");
3602 GST_OBJECT_UNLOCK (pad);
3603 return GST_FLOW_NOT_LINKED;
3607 GST_DEBUG ("Dropping data after FALSE probe return");
3608 gst_buffer_unref (*buffer);
3610 return GST_FLOW_UNEXPECTED;
3615 * gst_pad_push_event:
3616 * @pad: a #GstPad to push the event to.
3617 * @event: the #GstEvent to send to the pad.
3619 * Sends the event to the peer of the given pad. This function is
3620 * mainly used by elements to send events to their peer
3623 * This function takes owership of the provided event so you should
3624 * gst_event_ref() it if you want to reuse the event after this call.
3626 * Returns: TRUE if the event was handled.
3631 gst_pad_push_event (GstPad * pad, GstEvent * event)
3636 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
3637 g_return_val_if_fail (event != NULL, FALSE);
3638 g_return_val_if_fail (GST_IS_EVENT (event), FALSE);
3640 GST_OBJECT_LOCK (pad);
3641 switch (GST_EVENT_TYPE (event)) {
3642 case GST_EVENT_FLUSH_START:
3643 GST_PAD_SET_FLUSHING (pad);
3645 case GST_EVENT_FLUSH_STOP:
3646 GST_PAD_UNSET_FLUSHING (pad);
3652 if (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad))) {
3653 if (GST_EVENT_TYPE (event) == GST_EVENT_FLUSH_START) {
3654 GST_PAD_BLOCK_SIGNAL (pad);
3658 if (G_UNLIKELY (GST_PAD_DO_EVENT_SIGNALS (pad) > 0)) {
3659 GST_OBJECT_UNLOCK (pad);
3661 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (event)))
3664 GST_OBJECT_LOCK (pad);
3666 peerpad = GST_PAD_PEER (pad);
3667 if (peerpad == NULL)
3670 GST_LOG_OBJECT (peerpad, "sending event on peerpad");
3671 gst_object_ref (peerpad);
3672 GST_OBJECT_UNLOCK (pad);
3674 result = gst_pad_send_event (peerpad, event);
3676 gst_object_unref (peerpad);
3677 GST_LOG_OBJECT (peerpad, "sent event on peerpad");
3681 /* ERROR handling */
3684 GST_DEBUG_OBJECT (pad, "Dropping event after FALSE probe return");
3685 gst_event_unref (event);
3690 gst_event_unref (event);
3691 GST_OBJECT_UNLOCK (pad);
3697 * gst_pad_send_event:
3698 * @pad: a #GstPad to send the event to.
3699 * @event: the #GstEvent to send to the pad.
3701 * Sends the event to the pad. This function can be used
3702 * by applications to send events in the pipeline.
3704 * If @pad is a source pad, @event should be an upstream event. If @pad is a
3705 * sink pad, @event should be a downstream event. For example, you would not
3706 * send a #GST_EVENT_EOS on a src pad; EOS events only propagate downstream.
3707 * Furthermore, some downstream events have to be serialized with data flow,
3708 * like EOS, while some can travel out-of-band, like #GST_EVENT_FLUSH_START. If
3709 * the event needs to be serialized with data flow, this function will take the
3710 * pad's stream lock while calling its event function.
3712 * To find out whether an event type is upstream, downstream, or downstream and
3713 * serialized, see #GstEventTypeFlags, gst_event_type_get_flags(),
3714 * #GST_EVENT_IS_UPSTREAM, #GST_EVENT_IS_DOWNSTREAM, and
3715 * #GST_EVENT_IS_SERIALIZED. Note that in practice that an application or plugin
3716 * doesn't need to bother itself with this information; the core handles all
3717 * necessary locks and checks.
3719 * This function takes owership of the provided event so you should
3720 * gst_event_ref() it if you want to reuse the event after this call.
3722 * Returns: TRUE if the event was handled.
3725 gst_pad_send_event (GstPad * pad, GstEvent * event)
3727 gboolean result = FALSE;
3728 GstPadEventFunction eventfunc;
3729 gboolean serialized, need_unlock = FALSE;
3731 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
3732 g_return_val_if_fail (event != NULL, FALSE);
3734 GST_OBJECT_LOCK (pad);
3735 if (GST_PAD_IS_SINK (pad)) {
3736 if (G_UNLIKELY (!GST_EVENT_IS_DOWNSTREAM (event)))
3737 goto wrong_direction;
3738 serialized = GST_EVENT_IS_SERIALIZED (event);
3739 } else if (GST_PAD_IS_SRC (pad)) {
3740 if (G_UNLIKELY (!GST_EVENT_IS_UPSTREAM (event)))
3741 goto wrong_direction;
3742 /* events on srcpad never are serialized */
3745 goto unknown_direction;
3747 if (G_UNLIKELY (GST_EVENT_SRC (event) == NULL)) {
3748 GST_LOG_OBJECT (pad, "event had no source, setting pad as event source");
3749 GST_EVENT_SRC (event) = gst_object_ref (pad);
3753 if (G_UNLIKELY (GST_PAD_DO_EVENT_SIGNALS (pad) > 0)) {
3754 GST_OBJECT_UNLOCK (pad);
3756 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT_CAST (event)))
3759 GST_OBJECT_LOCK (pad);
3762 switch (GST_EVENT_TYPE (event)) {
3763 case GST_EVENT_FLUSH_START:
3764 GST_CAT_DEBUG (GST_CAT_EVENT,
3765 "have event type %d (FLUSH_START) on pad %s:%s",
3766 GST_EVENT_TYPE (event), GST_DEBUG_PAD_NAME (pad));
3768 /* can't even accept a flush begin event when flushing */
3769 if (GST_PAD_IS_FLUSHING (pad))
3771 GST_PAD_SET_FLUSHING (pad);
3772 GST_CAT_DEBUG (GST_CAT_EVENT, "set flush flag");
3774 case GST_EVENT_FLUSH_STOP:
3775 GST_PAD_UNSET_FLUSHING (pad);
3776 GST_CAT_DEBUG (GST_CAT_EVENT, "cleared flush flag");
3777 GST_OBJECT_UNLOCK (pad);
3778 /* grab stream lock */
3779 GST_PAD_STREAM_LOCK (pad);
3781 GST_OBJECT_LOCK (pad);
3784 GST_CAT_DEBUG (GST_CAT_EVENT, "have event type %s on pad %s:%s",
3785 GST_EVENT_TYPE_NAME (event), GST_DEBUG_PAD_NAME (pad));
3787 /* make this a little faster, no point in grabbing the lock
3788 * if the pad is allready flushing. */
3789 if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad)))
3793 /* lock order: STREAM_LOCK, LOCK */
3794 GST_OBJECT_UNLOCK (pad);
3795 GST_PAD_STREAM_LOCK (pad);
3797 GST_OBJECT_LOCK (pad);
3798 if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad)))
3803 if (G_UNLIKELY ((eventfunc = GST_PAD_EVENTFUNC (pad)) == NULL))
3806 GST_OBJECT_UNLOCK (pad);
3808 result = eventfunc (pad, event);
3811 GST_PAD_STREAM_UNLOCK (pad);
3815 /* ERROR handling */
3818 g_warning ("pad %s:%s sending %s event in wrong direction",
3819 GST_DEBUG_PAD_NAME (pad), GST_EVENT_TYPE_NAME (event));
3820 GST_OBJECT_UNLOCK (pad);
3821 gst_event_unref (event);
3826 g_warning ("pad %s:%s has invalid direction", GST_DEBUG_PAD_NAME (pad));
3827 GST_OBJECT_UNLOCK (pad);
3828 gst_event_unref (event);
3833 g_warning ("pad %s:%s has no event handler, file a bug.",
3834 GST_DEBUG_PAD_NAME (pad));
3835 GST_OBJECT_UNLOCK (pad);
3836 gst_event_unref (event);
3841 GST_OBJECT_UNLOCK (pad);
3843 GST_PAD_STREAM_UNLOCK (pad);
3844 GST_CAT_INFO (GST_CAT_EVENT, "Received event on flushing pad. Discarding");
3845 gst_event_unref (event);
3850 GST_DEBUG ("Dropping event after FALSE probe return");
3851 gst_event_unref (event);
3857 * gst_pad_set_element_private:
3858 * @pad: the #GstPad to set the private data of.
3859 * @priv: The private data to attach to the pad.
3861 * Set the given private data gpointer on the pad.
3862 * This function can only be used by the element that owns the pad.
3863 * No locking is performed in this function.
3866 gst_pad_set_element_private (GstPad * pad, gpointer priv)
3868 pad->element_private = priv;
3872 * gst_pad_get_element_private:
3873 * @pad: the #GstPad to get the private data of.
3875 * Gets the private data of a pad.
3876 * No locking is performed in this function.
3878 * Returns: a #gpointer to the private data.
3881 gst_pad_get_element_private (GstPad * pad)
3883 return pad->element_private;
3887 * gst_pad_start_task:
3888 * @pad: the #GstPad to start the task of
3889 * @func: the task function to call
3890 * @data: data passed to the task function
3892 * Starts a task that repeadedly calls @func with @data. This function
3893 * is nostly used in the pad activation function to start the
3894 * dataflow. This function will automatically acquire the STREAM_LOCK of
3895 * the pad before calling @func.
3897 * Returns: a TRUE if the task could be started.
3900 gst_pad_start_task (GstPad * pad, GstTaskFunction func, gpointer data)
3904 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
3905 g_return_val_if_fail (func != NULL, FALSE);
3907 GST_OBJECT_LOCK (pad);
3908 task = GST_PAD_TASK (pad);
3910 task = gst_task_create (func, data);
3911 gst_task_set_lock (task, GST_PAD_GET_STREAM_LOCK (pad));
3912 GST_PAD_TASK (pad) = task;
3914 gst_task_start (task);
3915 GST_OBJECT_UNLOCK (pad);
3921 * gst_pad_pause_task:
3922 * @pad: the #GstPad to pause the task of
3924 * Pause the task of @pad. This function will also make sure that the
3925 * function executed by the task will effectively stop.
3927 * Returns: a TRUE if the task could be paused or FALSE when the pad
3931 gst_pad_pause_task (GstPad * pad)
3935 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
3937 GST_OBJECT_LOCK (pad);
3938 task = GST_PAD_TASK (pad);
3941 gst_task_pause (task);
3942 GST_OBJECT_UNLOCK (pad);
3944 GST_PAD_STREAM_LOCK (pad);
3945 GST_PAD_STREAM_UNLOCK (pad);
3951 GST_DEBUG_OBJECT (pad, "pad has no task");
3952 GST_OBJECT_UNLOCK (pad);
3958 * gst_pad_stop_task:
3959 * @pad: the #GstPad to stop the task of
3961 * Stop the task of @pad. This function will also make sure that the
3962 * function executed by the task will effectively stop if not called
3963 * from the GstTaskFunction.
3965 * This function will deadlock if called from the GstTaskFunction of
3966 * the task. Use gst_task_pause() instead.
3968 * Regardless of whether the pad has a task, the stream lock is acquired and
3969 * released so as to ensure that streaming through this pad has finished.
3971 * Returns: a TRUE if the task could be stopped or FALSE on error.
3974 gst_pad_stop_task (GstPad * pad)
3978 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
3980 GST_OBJECT_LOCK (pad);
3981 task = GST_PAD_TASK (pad);
3984 GST_PAD_TASK (pad) = NULL;
3985 gst_task_stop (task);
3986 GST_OBJECT_UNLOCK (pad);
3988 GST_PAD_STREAM_LOCK (pad);
3989 GST_PAD_STREAM_UNLOCK (pad);
3991 gst_task_join (task);
3993 gst_object_unref (task);
3999 GST_OBJECT_UNLOCK (pad);
4001 GST_PAD_STREAM_LOCK (pad);
4002 GST_PAD_STREAM_UNLOCK (pad);