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;
239 GstObjectClass *gstobject_class;
241 gobject_class = G_OBJECT_CLASS (klass);
242 gstobject_class = GST_OBJECT_CLASS (klass);
244 parent_class = g_type_class_peek_parent (klass);
246 gobject_class->dispose = GST_DEBUG_FUNCPTR (gst_pad_dispose);
247 gobject_class->finalize = GST_DEBUG_FUNCPTR (gst_pad_finalize);
248 gobject_class->set_property = GST_DEBUG_FUNCPTR (gst_pad_set_property);
249 gobject_class->get_property = GST_DEBUG_FUNCPTR (gst_pad_get_property);
253 * @pad: the pad that emitted the signal
254 * @peer: the peer pad that has been connected
256 * Signals that a pad has been linked to the peer pad.
258 gst_pad_signals[PAD_LINKED] =
259 g_signal_new ("linked", G_TYPE_FROM_CLASS (klass), G_SIGNAL_RUN_LAST,
260 G_STRUCT_OFFSET (GstPadClass, linked), NULL, NULL,
261 gst_marshal_VOID__OBJECT, G_TYPE_NONE, 1, GST_TYPE_PAD);
264 * @pad: the pad that emitted the signal
265 * @peer: the peer pad that has been disconnected
267 * Signals that a pad has been unlinked from the peer pad.
269 gst_pad_signals[PAD_UNLINKED] =
270 g_signal_new ("unlinked", G_TYPE_FROM_CLASS (klass), G_SIGNAL_RUN_LAST,
271 G_STRUCT_OFFSET (GstPadClass, unlinked), NULL, NULL,
272 gst_marshal_VOID__OBJECT, G_TYPE_NONE, 1, GST_TYPE_PAD);
274 * GstPad::request-link:
275 * @pad: the pad that emitted the signal
276 * @peer: the peer pad for which a connection is requested
278 * Signals that a pad connection has been requested.
280 gst_pad_signals[PAD_REQUEST_LINK] =
281 g_signal_new ("request-link", G_TYPE_FROM_CLASS (klass),
282 G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GstPadClass, request_link), NULL,
283 NULL, gst_marshal_VOID__OBJECT, G_TYPE_NONE, 0);
287 * @pad: the pad that emitted the signal
288 * @mini_obj: new data
290 * Signals that new data is available on the pad. This signal is used
291 * internally for implementing pad probes.
292 * See gst_pad_add_*_probe functions.
294 * Returns: %TRUE to keep the data, %FALSE to drop it
296 gst_pad_signals[PAD_HAVE_DATA] =
297 g_signal_new ("have-data", G_TYPE_FROM_CLASS (klass),
298 G_SIGNAL_RUN_LAST | G_SIGNAL_DETAILED,
299 G_STRUCT_OFFSET (GstPadClass, have_data),
300 _gst_do_pass_data_accumulator,
301 NULL, gst_marshal_BOOLEAN__POINTER, G_TYPE_BOOLEAN, 1,
302 GST_TYPE_MINI_OBJECT);
304 g_object_class_install_property (gobject_class, PAD_PROP_CAPS,
305 g_param_spec_boxed ("caps", "Caps", "The capabilities of the pad",
306 GST_TYPE_CAPS, G_PARAM_READABLE));
307 g_object_class_install_property (gobject_class, PAD_PROP_DIRECTION,
308 g_param_spec_enum ("direction", "Direction", "The direction of the pad",
309 GST_TYPE_PAD_DIRECTION, GST_PAD_UNKNOWN,
310 G_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY));
311 g_object_class_install_property (gobject_class, PAD_PROP_TEMPLATE,
312 g_param_spec_object ("template", "Template",
313 "The GstPadTemplate of this pad", GST_TYPE_PAD_TEMPLATE,
316 #ifndef GST_DISABLE_LOADSAVE
317 gstobject_class->save_thyself = GST_DEBUG_FUNCPTR (gst_pad_save_thyself);
319 gstobject_class->path_string_separator = ".";
321 klass->have_data = default_have_data;
325 gst_pad_init (GstPad * pad)
327 pad->direction = GST_PAD_UNKNOWN;
330 pad->chainfunc = NULL;
334 pad->linkfunc = NULL;
335 pad->getcapsfunc = NULL;
337 pad->activatefunc = GST_DEBUG_FUNCPTR (gst_pad_activate_default);
338 pad->eventfunc = GST_DEBUG_FUNCPTR (gst_pad_event_default);
339 pad->querytypefunc = GST_DEBUG_FUNCPTR (gst_pad_get_query_types_default);
340 pad->queryfunc = GST_DEBUG_FUNCPTR (gst_pad_query_default);
341 pad->intlinkfunc = GST_DEBUG_FUNCPTR (gst_pad_get_internal_links_default);
342 GST_PAD_ACCEPTCAPSFUNC (pad) = GST_DEBUG_FUNCPTR (gst_pad_acceptcaps_default);
344 pad->do_buffer_signals = 0;
345 pad->do_event_signals = 0;
347 GST_PAD_UNSET_FLUSHING (pad);
349 pad->preroll_lock = g_mutex_new ();
350 pad->preroll_cond = g_cond_new ();
352 pad->stream_rec_lock = g_new (GStaticRecMutex, 1);
353 g_static_rec_mutex_init (pad->stream_rec_lock);
355 pad->block_cond = g_cond_new ();
359 gst_pad_dispose (GObject * object)
361 GstPad *pad = GST_PAD (object);
363 GST_CAT_DEBUG (GST_CAT_REFCOUNTING, "dispose %s:%s",
364 GST_DEBUG_PAD_NAME (pad));
366 /* we don't hold a ref to the peer so we can just set the
368 GST_PAD_PEER (pad) = NULL;
371 gst_caps_replace (&GST_PAD_CAPS (pad), NULL);
373 gst_pad_set_pad_template (pad, NULL);
375 G_OBJECT_CLASS (parent_class)->dispose (object);
379 gst_pad_finalize (GObject * object)
381 GstPad *pad = GST_PAD (object);
384 /* in case the task is still around, clean it up */
385 if ((task = GST_PAD_TASK (pad))) {
386 gst_task_join (task);
387 GST_PAD_TASK (pad) = NULL;
388 gst_object_unref (task);
391 if (pad->stream_rec_lock) {
392 g_static_rec_mutex_free (pad->stream_rec_lock);
393 g_free (pad->stream_rec_lock);
394 pad->stream_rec_lock = NULL;
396 if (pad->preroll_lock) {
397 g_mutex_free (pad->preroll_lock);
398 g_cond_free (pad->preroll_cond);
399 pad->preroll_lock = NULL;
400 pad->preroll_cond = NULL;
402 if (pad->block_cond) {
403 g_cond_free (pad->block_cond);
404 pad->block_cond = NULL;
407 G_OBJECT_CLASS (parent_class)->finalize (object);
411 gst_pad_set_property (GObject * object, guint prop_id,
412 const GValue * value, GParamSpec * pspec)
414 g_return_if_fail (GST_IS_PAD (object));
417 case PAD_PROP_DIRECTION:
418 GST_PAD_DIRECTION (object) = g_value_get_enum (value);
420 case PAD_PROP_TEMPLATE:
421 gst_pad_set_pad_template (GST_PAD_CAST (object),
422 (GstPadTemplate *) g_value_get_object (value));
425 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
431 gst_pad_get_property (GObject * object, guint prop_id,
432 GValue * value, GParamSpec * pspec)
434 g_return_if_fail (GST_IS_PAD (object));
438 g_value_set_boxed (value, GST_PAD_CAPS (object));
440 case PAD_PROP_DIRECTION:
441 g_value_set_enum (value, GST_PAD_DIRECTION (object));
443 case PAD_PROP_TEMPLATE:
444 g_value_set_object (value, GST_PAD_PAD_TEMPLATE (object));
447 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
454 * @name: the name of the new pad.
455 * @direction: the #GstPadDirection of the pad.
457 * Creates a new pad with the given name in the given direction.
458 * If name is NULL, a guaranteed unique name (across all pads)
460 * This function makes a copy of the name so you can safely free the name.
462 * Returns: a new #GstPad, or NULL in case of an error.
467 gst_pad_new (const gchar * name, GstPadDirection direction)
469 return g_object_new (GST_TYPE_PAD,
470 "name", name, "direction", direction, NULL);
474 * gst_pad_new_from_template:
475 * @templ: the pad template to use
476 * @name: the name of the element
478 * Creates a new pad with the given name from the given template.
479 * If name is NULL, a guaranteed unique name (across all pads)
481 * This function makes a copy of the name so you can safely free the name.
483 * Returns: a new #GstPad, or NULL in case of an error.
486 gst_pad_new_from_template (GstPadTemplate * templ, const gchar * name)
488 g_return_val_if_fail (GST_IS_PAD_TEMPLATE (templ), NULL);
490 return g_object_new (GST_TYPE_PAD,
491 "name", name, "direction", templ->direction, "template", templ, NULL);
495 * gst_pad_new_from_static_template:
496 * @templ: the #GstStaticPadTemplate to use
497 * @name: the name of the element
499 * Creates a new pad with the given name from the given static template.
500 * If name is NULL, a guaranteed unique name (across all pads)
502 * This function makes a copy of the name so you can safely free the name.
504 * Returns: a new #GstPad, or NULL in case of an error.
507 gst_pad_new_from_static_template (GstStaticPadTemplate * templ,
511 GstPadTemplate *template;
513 template = gst_static_pad_template_get (templ);
514 pad = gst_pad_new_from_template (template, name);
515 gst_object_unref (template);
520 * gst_pad_get_direction:
521 * @pad: a #GstPad to get the direction of.
523 * Gets the direction of the pad. The direction of the pad is
524 * decided at construction time so this function does not take
527 * Returns: the #GstPadDirection of the pad.
532 gst_pad_get_direction (GstPad * pad)
534 GstPadDirection result;
536 /* PAD_UNKNOWN is a little silly but we need some sort of
537 * error return value */
538 g_return_val_if_fail (GST_IS_PAD (pad), GST_PAD_UNKNOWN);
540 GST_OBJECT_LOCK (pad);
541 result = GST_PAD_DIRECTION (pad);
542 GST_OBJECT_UNLOCK (pad);
548 gst_pad_activate_default (GstPad * pad)
550 return gst_pad_activate_push (pad, TRUE);
554 pre_activate (GstPad * pad, GstActivateMode new_mode)
557 case GST_ACTIVATE_PUSH:
558 case GST_ACTIVATE_PULL:
559 GST_OBJECT_LOCK (pad);
560 GST_DEBUG_OBJECT (pad, "setting ACTIVATE_MODE %d, unset flushing",
562 GST_PAD_UNSET_FLUSHING (pad);
563 GST_PAD_ACTIVATE_MODE (pad) = new_mode;
564 GST_OBJECT_UNLOCK (pad);
566 case GST_ACTIVATE_NONE:
567 GST_OBJECT_LOCK (pad);
568 GST_DEBUG_OBJECT (pad, "setting ACTIVATE_MODE NONE, set flushing",
570 GST_PAD_SET_FLUSHING (pad);
571 /* unlock blocked pads so element can resume and stop */
572 GST_PAD_BLOCK_SIGNAL (pad);
573 GST_OBJECT_UNLOCK (pad);
579 post_activate (GstPad * pad, GstActivateMode new_mode)
582 case GST_ACTIVATE_PUSH:
583 case GST_ACTIVATE_PULL:
586 case GST_ACTIVATE_NONE:
587 /* ensures that streaming stops */
588 GST_PAD_STREAM_LOCK (pad);
589 /* while we're at it set activation mode */
590 GST_OBJECT_LOCK (pad);
591 GST_DEBUG_OBJECT (pad, "setting ACTIVATE_MODE %d", new_mode);
592 GST_PAD_ACTIVATE_MODE (pad) = new_mode;
593 GST_OBJECT_UNLOCK (pad);
594 GST_PAD_STREAM_UNLOCK (pad);
600 * gst_pad_set_active:
601 * @pad: the #GstPad to activate or deactivate.
602 * @active: whether or not the pad should be active.
604 * Activates or deactivates the given pad.
605 * Normally called from within core state change functions.
607 * If @active, makes sure the pad is active. If it is already active, either in
608 * push or pull mode, just return. Otherwise dispatches to the pad's activate
609 * function to perform the actual activation.
611 * If not @active, checks the pad's current mode and calls
612 * gst_pad_activate_push() or gst_pad_activate_pull(), as appropriate, with a
615 * Returns: #TRUE if the operation was successful.
620 gst_pad_set_active (GstPad * pad, gboolean active)
623 gboolean ret = FALSE;
625 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
627 GST_OBJECT_LOCK (pad);
628 old = GST_PAD_ACTIVATE_MODE (pad);
629 GST_OBJECT_UNLOCK (pad);
633 case GST_ACTIVATE_PUSH:
634 case GST_ACTIVATE_PULL:
637 case GST_ACTIVATE_NONE:
638 ret = (GST_PAD_ACTIVATEFUNC (pad)) (pad);
643 case GST_ACTIVATE_PUSH:
644 ret = gst_pad_activate_push (pad, FALSE);
646 case GST_ACTIVATE_PULL:
647 ret = gst_pad_activate_pull (pad, FALSE);
649 case GST_ACTIVATE_NONE:
655 if (!active && !ret) {
656 GST_OBJECT_LOCK (pad);
657 g_critical ("Failed to deactivate pad %s:%s, very bad",
658 GST_DEBUG_PAD_NAME (pad));
659 GST_OBJECT_UNLOCK (pad);
666 * gst_pad_activate_pull:
667 * @pad: the #GstPad to activate or deactivate.
668 * @active: whether or not the pad should be active.
670 * Activates or deactivates the given pad in pull mode via dispatching to the
671 * pad's activatepullfunc. For use from within pad activation functions only.
672 * When called on sink pads, will first proxy the call to the peer pad, which is
673 * expected to activate its internally linked pads from within its activate_pull
676 * If you don't know what this is, you probably don't want to call it.
678 * Returns: TRUE if the operation was successful.
683 gst_pad_activate_pull (GstPad * pad, gboolean active)
685 GstActivateMode old, new;
688 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
690 GST_OBJECT_LOCK (pad);
691 old = GST_PAD_ACTIVATE_MODE (pad);
692 GST_OBJECT_UNLOCK (pad);
694 if ((active && old == GST_ACTIVATE_PULL)
695 || (!active && old == GST_ACTIVATE_NONE))
699 g_return_val_if_fail (old == GST_ACTIVATE_NONE, FALSE);
701 g_return_val_if_fail (old == GST_ACTIVATE_PULL, FALSE);
704 if (gst_pad_get_direction (pad) == GST_PAD_SINK) {
705 if ((peer = gst_pad_get_peer (pad))) {
706 if (!gst_pad_activate_pull (peer, active))
708 gst_object_unref (peer);
711 if (GST_PAD_GETRANGEFUNC (pad) == NULL)
712 goto failure; /* Can't activate pull on a src without a
716 new = active ? GST_ACTIVATE_PULL : GST_ACTIVATE_NONE;
717 pre_activate (pad, new);
719 if (GST_PAD_ACTIVATEPULLFUNC (pad)) {
720 if (!GST_PAD_ACTIVATEPULLFUNC (pad) (pad, active))
723 /* can happen for sinks of passthrough elements */
726 post_activate (pad, new);
728 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "%s in pull mode",
729 active ? "activated" : "deactivated");
734 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "already %s in pull mode",
735 active ? "activated" : "deactivated");
740 GST_OBJECT_LOCK (peer);
741 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
742 "activate_pull on peer (%s:%s) failed", GST_DEBUG_PAD_NAME (peer));
743 GST_OBJECT_UNLOCK (peer);
744 gst_object_unref (peer);
749 GST_CAT_INFO_OBJECT (GST_CAT_PADS, pad, "failed to %s in pull mode",
750 active ? "activate" : "deactivate");
751 pre_activate (pad, GST_ACTIVATE_NONE);
752 post_activate (pad, GST_ACTIVATE_NONE);
758 * gst_pad_activate_push:
759 * @pad: the #GstPad to activate or deactivate.
760 * @active: whether the pad should be active or not.
762 * Activates or deactivates the given pad in push mode via dispatching to the
763 * pad's activatepushfunc. For use from within pad activation functions only.
765 * If you don't know what this is, you probably don't want to call it.
767 * Returns: %TRUE if the operation was successful.
772 gst_pad_activate_push (GstPad * pad, gboolean active)
774 GstActivateMode old, new;
776 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
777 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "trying to set %s in push mode",
778 active ? "activated" : "deactivated");
780 GST_OBJECT_LOCK (pad);
781 old = GST_PAD_ACTIVATE_MODE (pad);
782 GST_OBJECT_UNLOCK (pad);
784 if ((active && old == GST_ACTIVATE_PUSH)
785 || (!active && old == GST_ACTIVATE_NONE))
789 g_return_val_if_fail (old == GST_ACTIVATE_NONE, FALSE);
791 g_return_val_if_fail (old == GST_ACTIVATE_PUSH, FALSE);
794 new = active ? GST_ACTIVATE_PUSH : GST_ACTIVATE_NONE;
795 pre_activate (pad, new);
797 if (GST_PAD_ACTIVATEPUSHFUNC (pad)) {
798 if (!GST_PAD_ACTIVATEPUSHFUNC (pad) (pad, active)) {
802 /* quite ok, element relies on state change func to prepare itself */
805 post_activate (pad, new);
807 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "%s in push mode",
808 active ? "activated" : "deactivated");
813 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "already %s in push mode",
814 active ? "activated" : "deactivated");
819 GST_CAT_INFO_OBJECT (GST_CAT_PADS, pad, "failed to %s in push mode",
820 active ? "activate" : "deactivate");
821 pre_activate (pad, GST_ACTIVATE_NONE);
822 post_activate (pad, GST_ACTIVATE_NONE);
829 * @pad: the #GstPad to query
831 * Query if a pad is active
833 * Returns: TRUE if the pad is active.
838 gst_pad_is_active (GstPad * pad)
840 gboolean result = FALSE;
842 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
844 GST_OBJECT_LOCK (pad);
845 result = GST_PAD_MODE_ACTIVATE (GST_PAD_ACTIVATE_MODE (pad));
846 GST_OBJECT_UNLOCK (pad);
852 * gst_pad_set_blocked_async:
853 * @pad: the #GstPad to block or unblock
854 * @blocked: boolean indicating whether the pad should be blocked or unblocked
855 * @callback: #GstPadBlockCallback that will be called when the
857 * @user_data: user data passed to the callback
859 * Blocks or unblocks the dataflow on a pad. The provided callback
860 * is called when the operation succeeds; this happens right before the next
861 * attempt at pushing a buffer on the pad.
863 * This can take a while as the pad can only become blocked when real dataflow
865 * When the pipeline is stalled, for example in PAUSED, this can
866 * take an indeterminate amount of time.
867 * You can pass NULL as the callback to make this call block. Be careful with
868 * this blocking call as it might not return for reasons stated above.
870 * Returns: TRUE if the pad could be blocked. This function can fail
871 * if wrong parameters were passed or the pad was already in the
877 gst_pad_set_blocked_async (GstPad * pad, gboolean blocked,
878 GstPadBlockCallback callback, gpointer user_data)
880 gboolean was_blocked, was_ghost = FALSE;
882 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
884 if (GST_IS_GHOST_PAD (pad)) {
885 pad = gst_ghost_pad_get_target (GST_GHOST_PAD (pad));
892 GST_OBJECT_LOCK (pad);
894 was_blocked = GST_PAD_IS_BLOCKED (pad);
896 if (G_UNLIKELY (was_blocked == blocked))
897 goto had_right_state;
900 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "blocking pad %s:%s",
901 GST_DEBUG_PAD_NAME (pad));
903 GST_OBJECT_FLAG_SET (pad, GST_PAD_BLOCKED);
904 pad->block_callback = callback;
905 pad->block_data = user_data;
907 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "waiting for block");
908 GST_PAD_BLOCK_WAIT (pad);
909 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "blocked");
912 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "unblocking pad %s:%s",
913 GST_DEBUG_PAD_NAME (pad));
915 GST_OBJECT_FLAG_UNSET (pad, GST_PAD_BLOCKED);
917 pad->block_callback = callback;
918 pad->block_data = user_data;
921 GST_PAD_BLOCK_SIGNAL (pad);
923 GST_PAD_BLOCK_SIGNAL (pad);
924 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "waiting for unblock");
925 GST_PAD_BLOCK_WAIT (pad);
926 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "unblocked");
929 GST_OBJECT_UNLOCK (pad);
932 gst_object_unref (pad);
939 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
940 "pad %s:%s was in right state (%d)", GST_DEBUG_PAD_NAME (pad),
942 GST_OBJECT_UNLOCK (pad);
945 gst_object_unref (pad);
952 * gst_pad_set_blocked:
953 * @pad: the #GstPad to block or unblock
954 * @blocked: boolean indicating we should block or unblock
956 * Blocks or unblocks the dataflow on a pad. This function is
957 * a shortcut for gst_pad_set_blocked_async() with a NULL
960 * Returns: TRUE if the pad could be blocked. This function can fail
961 * wrong parameters were passed or the pad was already in the
967 gst_pad_set_blocked (GstPad * pad, gboolean blocked)
969 return gst_pad_set_blocked_async (pad, blocked, NULL, NULL);
973 * gst_pad_is_blocked:
974 * @pad: the #GstPad to query
976 * Checks if the pad is blocked or not. This function returns the
977 * last requested state of the pad. It is not certain that the pad
978 * is actually blocked at this point.
980 * Returns: TRUE if the pad is blocked.
985 gst_pad_is_blocked (GstPad * pad)
987 gboolean result = FALSE;
989 g_return_val_if_fail (GST_IS_PAD (pad), result);
991 GST_OBJECT_LOCK (pad);
992 result = GST_OBJECT_FLAG_IS_SET (pad, GST_PAD_BLOCKED);
993 GST_OBJECT_UNLOCK (pad);
999 * gst_pad_set_activate_function:
1000 * @pad: a sink #GstPad.
1001 * @activate: the #GstPadActivateFunction to set.
1003 * Sets the given activate function for the pad. The activate function will
1004 * dispatch to activate_push or activate_pull to perform the actual activation.
1005 * Only makes sense to set on sink pads.
1007 * Call this function if your sink pad can start a pull-based task.
1010 gst_pad_set_activate_function (GstPad * pad, GstPadActivateFunction activate)
1012 g_return_if_fail (GST_IS_PAD (pad));
1014 GST_PAD_ACTIVATEFUNC (pad) = activate;
1015 GST_CAT_DEBUG (GST_CAT_PADS, "activatefunc for %s:%s set to %s",
1016 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (activate));
1020 * gst_pad_set_activatepull_function:
1021 * @pad: a sink #GstPad.
1022 * @activatepull: the #GstPadActivateModeFunction to set.
1024 * Sets the given activate_pull function for the pad. An activate_pull function
1025 * prepares the element and any upstream connections for pulling. See XXX
1026 * part-activation.txt for details.
1029 gst_pad_set_activatepull_function (GstPad * pad,
1030 GstPadActivateModeFunction activatepull)
1032 g_return_if_fail (GST_IS_PAD (pad));
1034 GST_PAD_ACTIVATEPULLFUNC (pad) = activatepull;
1035 GST_CAT_DEBUG (GST_CAT_PADS, "activatepullfunc for %s:%s set to %s",
1036 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (activatepull));
1040 * gst_pad_set_activatepush_function:
1041 * @pad: a sink #GstPad.
1042 * @activatepush: the #GstPadActivateModeFunction to set.
1044 * Sets the given activate_push function for the pad. An activate_push function
1045 * prepares the element for pushing. See XXX part-activation.txt for details.
1048 gst_pad_set_activatepush_function (GstPad * pad,
1049 GstPadActivateModeFunction activatepush)
1051 g_return_if_fail (GST_IS_PAD (pad));
1053 GST_PAD_ACTIVATEPUSHFUNC (pad) = activatepush;
1054 GST_CAT_DEBUG (GST_CAT_PADS, "activatepushfunc for %s:%s set to %s",
1055 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (activatepush));
1059 * gst_pad_set_chain_function:
1060 * @pad: a sink #GstPad.
1061 * @chain: the #GstPadChainFunction to set.
1063 * Sets the given chain function for the pad. The chain function is called to
1064 * process a #GstBuffer input buffer.
1067 gst_pad_set_chain_function (GstPad * pad, GstPadChainFunction chain)
1069 g_return_if_fail (GST_IS_PAD (pad));
1070 g_return_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SINK);
1072 GST_PAD_CHAINFUNC (pad) = chain;
1073 GST_CAT_DEBUG (GST_CAT_PADS, "chainfunc for %s:%s set to %s",
1074 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (chain));
1078 * gst_pad_set_getrange_function:
1079 * @pad: a source #GstPad.
1080 * @get: the #GstPadGetRangeFunction to set.
1082 * Sets the given getrange function for the pad. The getrange function is called to
1083 * produce a new #GstBuffer to start the processing pipeline. Getrange functions cannot
1087 gst_pad_set_getrange_function (GstPad * pad, GstPadGetRangeFunction get)
1089 g_return_if_fail (GST_IS_PAD (pad));
1090 g_return_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SRC);
1092 GST_PAD_GETRANGEFUNC (pad) = get;
1094 GST_CAT_DEBUG (GST_CAT_PADS, "getrangefunc for %s:%s set to %s",
1095 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (get));
1099 * gst_pad_set_checkgetrange_function:
1100 * @pad: a source #GstPad.
1101 * @check: the #GstPadCheckGetRangeFunction to set.
1103 * Sets the given checkgetrange function for the pad. Implement this function on
1104 * a pad if you dynamically support getrange based scheduling on the pad.
1107 gst_pad_set_checkgetrange_function (GstPad * pad,
1108 GstPadCheckGetRangeFunction check)
1110 g_return_if_fail (GST_IS_PAD (pad));
1111 g_return_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SRC);
1113 GST_PAD_CHECKGETRANGEFUNC (pad) = check;
1115 GST_CAT_DEBUG (GST_CAT_PADS, "checkgetrangefunc for %s:%s set to %s",
1116 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (check));
1120 * gst_pad_set_event_function:
1121 * @pad: a source #GstPad.
1122 * @event: the #GstPadEventFunction to set.
1124 * Sets the given event handler for the pad.
1127 gst_pad_set_event_function (GstPad * pad, GstPadEventFunction event)
1129 g_return_if_fail (GST_IS_PAD (pad));
1131 GST_PAD_EVENTFUNC (pad) = event;
1133 GST_CAT_DEBUG (GST_CAT_PADS, "eventfunc for %s:%s set to %s",
1134 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (event));
1138 * gst_pad_set_query_function:
1139 * @pad: a #GstPad of either direction.
1140 * @query: the #GstPadQueryFunction to set.
1142 * Set the given query function for the pad.
1145 gst_pad_set_query_function (GstPad * pad, GstPadQueryFunction query)
1147 g_return_if_fail (GST_IS_PAD (pad));
1149 GST_PAD_QUERYFUNC (pad) = query;
1151 GST_CAT_DEBUG (GST_CAT_PADS, "queryfunc for %s:%s set to %s",
1152 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (query));
1156 * gst_pad_set_query_type_function:
1157 * @pad: a #GstPad of either direction.
1158 * @type_func: the #GstPadQueryTypeFunction to set.
1160 * Set the given query type function for the pad.
1163 gst_pad_set_query_type_function (GstPad * pad,
1164 GstPadQueryTypeFunction type_func)
1166 g_return_if_fail (GST_IS_PAD (pad));
1168 GST_PAD_QUERYTYPEFUNC (pad) = type_func;
1170 GST_CAT_DEBUG (GST_CAT_PADS, "querytypefunc for %s:%s set to %s",
1171 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (type_func));
1175 * gst_pad_get_query_types:
1178 * Get an array of supported queries that can be performed
1181 * Returns: a zero-terminated array of #GstQueryType.
1183 const GstQueryType *
1184 gst_pad_get_query_types (GstPad * pad)
1186 GstPadQueryTypeFunction func;
1188 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
1190 if (G_UNLIKELY ((func = GST_PAD_QUERYTYPEFUNC (pad)) == NULL))
1202 gst_pad_get_query_types_dispatcher (GstPad * pad, const GstQueryType ** data)
1204 *data = gst_pad_get_query_types (pad);
1210 * gst_pad_get_query_types_default:
1213 * Invoke the default dispatcher for the query types on
1216 * Returns: an zero-terminated array of #GstQueryType, or NULL if none of the
1217 * internally-linked pads has a query types function.
1219 const GstQueryType *
1220 gst_pad_get_query_types_default (GstPad * pad)
1222 GstQueryType *result = NULL;
1224 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
1226 gst_pad_dispatcher (pad, (GstPadDispatcherFunction)
1227 gst_pad_get_query_types_dispatcher, &result);
1233 * gst_pad_set_internal_link_function:
1234 * @pad: a #GstPad of either direction.
1235 * @intlink: the #GstPadIntLinkFunction to set.
1237 * Sets the given internal link function for the pad.
1240 gst_pad_set_internal_link_function (GstPad * pad, GstPadIntLinkFunction intlink)
1242 g_return_if_fail (GST_IS_PAD (pad));
1244 GST_PAD_INTLINKFUNC (pad) = intlink;
1245 GST_CAT_DEBUG (GST_CAT_PADS, "internal link for %s:%s set to %s",
1246 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (intlink));
1250 * gst_pad_set_link_function:
1252 * @link: the #GstPadLinkFunction to set.
1254 * Sets the given link function for the pad. It will be called when
1255 * the pad is linked with another pad.
1257 * The return value #GST_PAD_LINK_OK should be used when the connection can be
1260 * The return value #GST_PAD_LINK_REFUSED should be used when the connection
1261 * cannot be made for some reason.
1263 * If @link is installed on a source pad, it should call the #GstPadLinkFunction
1264 * of the peer sink pad, if present.
1267 gst_pad_set_link_function (GstPad * pad, GstPadLinkFunction link)
1269 g_return_if_fail (GST_IS_PAD (pad));
1271 GST_PAD_LINKFUNC (pad) = link;
1272 GST_CAT_DEBUG (GST_CAT_PADS, "linkfunc for %s:%s set to %s",
1273 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (link));
1277 * gst_pad_set_unlink_function:
1279 * @unlink: the #GstPadUnlinkFunction to set.
1281 * Sets the given unlink function for the pad. It will be called
1282 * when the pad is unlinked.
1285 gst_pad_set_unlink_function (GstPad * pad, GstPadUnlinkFunction unlink)
1287 g_return_if_fail (GST_IS_PAD (pad));
1289 GST_PAD_UNLINKFUNC (pad) = unlink;
1290 GST_CAT_DEBUG (GST_CAT_PADS, "unlinkfunc for %s:%s set to %s",
1291 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (unlink));
1295 * gst_pad_set_getcaps_function:
1297 * @getcaps: the #GstPadGetCapsFunction to set.
1299 * Sets the given getcaps function for the pad. @getcaps should return the
1300 * allowable caps for a pad in the context of the element's state, its link to
1301 * other elements, and the devices or files it has opened. These caps must be a
1302 * subset of the pad template caps. In the NULL state with no links, @getcaps
1303 * should ideally return the same caps as the pad template. In rare
1304 * circumstances, an object property can affect the caps returned by @getcaps,
1305 * but this is discouraged.
1307 * You do not need to call this function if @pad's allowed caps are always the
1308 * same as the pad template caps. This can only be true if the padtemplate
1309 * has fixed simple caps.
1311 * For most filters, the caps returned by @getcaps is directly affected by the
1312 * allowed caps on other pads. For demuxers and decoders, the caps returned by
1313 * the srcpad's getcaps function is directly related to the stream data. Again,
1314 * @getcaps should return the most specific caps it reasonably can, since this
1315 * helps with autoplugging.
1317 * Note that the return value from @getcaps is owned by the caller, so the caller
1318 * should unref the caps after usage.
1321 gst_pad_set_getcaps_function (GstPad * pad, GstPadGetCapsFunction getcaps)
1323 g_return_if_fail (GST_IS_PAD (pad));
1325 GST_PAD_GETCAPSFUNC (pad) = getcaps;
1326 GST_CAT_DEBUG (GST_CAT_PADS, "getcapsfunc for %s:%s set to %s",
1327 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (getcaps));
1331 * gst_pad_set_acceptcaps_function:
1333 * @acceptcaps: the #GstPadAcceptCapsFunction to set.
1335 * Sets the given acceptcaps function for the pad. The acceptcaps function
1336 * will be called to check if the pad can accept the given caps. Setting the
1337 * acceptcaps function to NULL restores the default behaviour of allowing
1338 * any caps that matches the caps from gst_pad_get_caps.
1341 gst_pad_set_acceptcaps_function (GstPad * pad,
1342 GstPadAcceptCapsFunction acceptcaps)
1344 g_return_if_fail (GST_IS_PAD (pad));
1346 GST_PAD_ACCEPTCAPSFUNC (pad) = acceptcaps;
1347 GST_CAT_DEBUG (GST_CAT_PADS, "acceptcapsfunc for %s:%s set to %s",
1348 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (acceptcaps));
1352 * gst_pad_set_fixatecaps_function:
1354 * @fixatecaps: the #GstPadFixateCapsFunction to set.
1356 * Sets the given fixatecaps function for the pad. The fixatecaps function
1357 * will be called whenever the default values for a GstCaps needs to be
1361 gst_pad_set_fixatecaps_function (GstPad * pad,
1362 GstPadFixateCapsFunction fixatecaps)
1364 g_return_if_fail (GST_IS_PAD (pad));
1366 GST_PAD_FIXATECAPSFUNC (pad) = fixatecaps;
1367 GST_CAT_DEBUG (GST_CAT_PADS, "fixatecapsfunc for %s:%s set to %s",
1368 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (fixatecaps));
1372 * gst_pad_set_setcaps_function:
1374 * @setcaps: the #GstPadSetCapsFunction to set.
1376 * Sets the given setcaps function for the pad. The setcaps function
1377 * will be called whenever a buffer with a new media type is pushed or
1378 * pulled from the pad. The pad/element needs to update its internal
1379 * structures to process the new media type. If this new type is not
1380 * acceptable, the setcaps function should return FALSE.
1383 gst_pad_set_setcaps_function (GstPad * pad, GstPadSetCapsFunction setcaps)
1385 g_return_if_fail (GST_IS_PAD (pad));
1387 GST_PAD_SETCAPSFUNC (pad) = setcaps;
1388 GST_CAT_DEBUG (GST_CAT_PADS, "setcapsfunc for %s:%s set to %s",
1389 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (setcaps));
1393 * gst_pad_set_bufferalloc_function:
1394 * @pad: a sink #GstPad.
1395 * @bufalloc: the #GstPadBufferAllocFunction to set.
1397 * Sets the given bufferalloc function for the pad. Note that the
1398 * bufferalloc function can only be set on sinkpads.
1401 gst_pad_set_bufferalloc_function (GstPad * pad,
1402 GstPadBufferAllocFunction bufalloc)
1404 g_return_if_fail (GST_IS_PAD (pad));
1405 g_return_if_fail (GST_PAD_IS_SINK (pad));
1407 GST_PAD_BUFFERALLOCFUNC (pad) = bufalloc;
1408 GST_CAT_DEBUG (GST_CAT_PADS, "bufferallocfunc for %s:%s set to %s",
1409 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (bufalloc));
1414 * @srcpad: the source #GstPad to unlink.
1415 * @sinkpad: the sink #GstPad to unlink.
1417 * Unlinks the source pad from the sink pad. Will emit the "unlinked" signal on
1420 * Returns: TRUE if the pads were unlinked. This function returns FALSE if
1421 * the pads were not linked together.
1426 gst_pad_unlink (GstPad * srcpad, GstPad * sinkpad)
1428 g_return_val_if_fail (GST_IS_PAD (srcpad), FALSE);
1429 g_return_val_if_fail (GST_IS_PAD (sinkpad), FALSE);
1431 GST_CAT_INFO (GST_CAT_ELEMENT_PADS, "unlinking %s:%s(%p) and %s:%s(%p)",
1432 GST_DEBUG_PAD_NAME (srcpad), srcpad,
1433 GST_DEBUG_PAD_NAME (sinkpad), sinkpad);
1435 GST_OBJECT_LOCK (srcpad);
1437 if (G_UNLIKELY (GST_PAD_DIRECTION (srcpad) != GST_PAD_SRC))
1440 GST_OBJECT_LOCK (sinkpad);
1442 if (G_UNLIKELY (GST_PAD_DIRECTION (sinkpad) != GST_PAD_SINK))
1445 if (G_UNLIKELY (GST_PAD_PEER (srcpad) != sinkpad))
1446 goto not_linked_together;
1448 if (GST_PAD_UNLINKFUNC (srcpad)) {
1449 GST_PAD_UNLINKFUNC (srcpad) (srcpad);
1451 if (GST_PAD_UNLINKFUNC (sinkpad)) {
1452 GST_PAD_UNLINKFUNC (sinkpad) (sinkpad);
1455 /* first clear peers */
1456 GST_PAD_PEER (srcpad) = NULL;
1457 GST_PAD_PEER (sinkpad) = NULL;
1459 GST_OBJECT_UNLOCK (sinkpad);
1460 GST_OBJECT_UNLOCK (srcpad);
1462 /* fire off a signal to each of the pads telling them
1463 * that they've been unlinked */
1464 g_signal_emit (G_OBJECT (srcpad), gst_pad_signals[PAD_UNLINKED], 0, sinkpad);
1465 g_signal_emit (G_OBJECT (sinkpad), gst_pad_signals[PAD_UNLINKED], 0, srcpad);
1467 GST_CAT_INFO (GST_CAT_ELEMENT_PADS, "unlinked %s:%s and %s:%s",
1468 GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (sinkpad));
1474 g_critical ("pad %s is not a source pad", GST_PAD_NAME (srcpad));
1475 GST_OBJECT_UNLOCK (srcpad);
1480 g_critical ("pad %s is not a sink pad", GST_PAD_NAME (sinkpad));
1481 GST_OBJECT_UNLOCK (sinkpad);
1482 GST_OBJECT_UNLOCK (srcpad);
1485 not_linked_together:
1487 /* we do not emit a warning in this case because unlinking cannot
1488 * be made MT safe.*/
1489 GST_OBJECT_UNLOCK (sinkpad);
1490 GST_OBJECT_UNLOCK (srcpad);
1496 * gst_pad_is_linked:
1497 * @pad: pad to check
1499 * Checks if a @pad is linked to another pad or not.
1501 * Returns: TRUE if the pad is linked, FALSE otherwise.
1506 gst_pad_is_linked (GstPad * pad)
1510 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
1512 GST_OBJECT_LOCK (pad);
1513 result = (GST_PAD_PEER (pad) != NULL);
1514 GST_OBJECT_UNLOCK (pad);
1519 /* get the caps from both pads and see if the intersection
1522 * This function should be called with the pad LOCK on both
1526 gst_pad_link_check_compatible_unlocked (GstPad * src, GstPad * sink)
1532 srccaps = gst_pad_get_caps_unlocked (src);
1533 sinkcaps = gst_pad_get_caps_unlocked (sink);
1535 GST_CAT_DEBUG (GST_CAT_CAPS, "src caps %" GST_PTR_FORMAT, srccaps);
1536 GST_CAT_DEBUG (GST_CAT_CAPS, "sink caps %" GST_PTR_FORMAT, sinkcaps);
1538 /* if we have caps on both pads we can check the intersection. If one
1539 * of the caps is NULL, we return TRUE. */
1540 if (srccaps == NULL || sinkcaps == NULL)
1543 icaps = gst_caps_intersect (srccaps, sinkcaps);
1544 gst_caps_unref (srccaps);
1545 gst_caps_unref (sinkcaps);
1550 GST_CAT_DEBUG (GST_CAT_CAPS,
1551 "intersection caps %p %" GST_PTR_FORMAT, icaps, icaps);
1553 if (gst_caps_is_empty (icaps))
1556 gst_caps_unref (icaps);
1561 /* incompatible cases */
1564 GST_CAT_DEBUG (GST_CAT_CAPS, "intersection gave NULL");
1569 GST_CAT_DEBUG (GST_CAT_CAPS, "intersection is EMPTY");
1570 gst_caps_unref (icaps);
1575 /* check if the grandparents of both pads are the same.
1576 * This check is required so that we don't try to link
1577 * pads from elements in different bins without ghostpads.
1579 * The LOCK should be helt on both pads
1582 gst_pad_link_check_hierarchy (GstPad * src, GstPad * sink)
1584 GstObject *psrc, *psink;
1585 gboolean res = TRUE;
1587 psrc = GST_OBJECT_PARENT (src);
1588 psink = GST_OBJECT_PARENT (sink);
1590 /* if one of the pads has no parent, we allow the link */
1591 if (psrc && psink) {
1592 /* if the parents are the same, we have a loop */
1593 if (psrc == psink) {
1594 GST_CAT_DEBUG (GST_CAT_CAPS, "pads have same parent %" GST_PTR_FORMAT,
1599 /* if they both have a parent, we check the grandparents */
1600 psrc = gst_object_get_parent (psrc);
1601 psink = gst_object_get_parent (psink);
1603 if (psrc != psink) {
1604 /* if they have grandparents but they are not the same */
1605 GST_CAT_DEBUG (GST_CAT_CAPS,
1606 "pads have different grandparents %" GST_PTR_FORMAT " and %"
1607 GST_PTR_FORMAT, psrc, psink);
1611 gst_object_unref (psrc);
1613 gst_object_unref (psink);
1619 /* FIXME leftover from an attempt at refactoring... */
1620 /* call with the two pads unlocked */
1621 static GstPadLinkReturn
1622 gst_pad_link_prepare (GstPad * srcpad, GstPad * sinkpad)
1624 /* generic checks */
1625 g_return_val_if_fail (GST_IS_PAD (srcpad), GST_PAD_LINK_REFUSED);
1626 g_return_val_if_fail (GST_IS_PAD (sinkpad), GST_PAD_LINK_REFUSED);
1628 GST_CAT_INFO (GST_CAT_PADS, "trying to link %s:%s and %s:%s",
1629 GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (sinkpad));
1631 GST_OBJECT_LOCK (srcpad);
1633 if (G_UNLIKELY (GST_PAD_DIRECTION (srcpad) != GST_PAD_SRC))
1636 if (G_UNLIKELY (GST_PAD_PEER (srcpad) != NULL))
1637 goto src_was_linked;
1639 GST_OBJECT_LOCK (sinkpad);
1641 if (G_UNLIKELY (GST_PAD_DIRECTION (sinkpad) != GST_PAD_SINK))
1644 if (G_UNLIKELY (GST_PAD_PEER (sinkpad) != NULL))
1645 goto sink_was_linked;
1647 /* check hierarchy, pads can only be linked if the grandparents
1649 if (!gst_pad_link_check_hierarchy (srcpad, sinkpad))
1650 goto wrong_hierarchy;
1652 /* check pad caps for non-empty intersection */
1653 if (!gst_pad_link_check_compatible_unlocked (srcpad, sinkpad))
1656 /* FIXME check pad scheduling for non-empty intersection */
1658 return GST_PAD_LINK_OK;
1662 g_critical ("pad %s is not a source pad", GST_PAD_NAME (srcpad));
1663 GST_OBJECT_UNLOCK (srcpad);
1664 return GST_PAD_LINK_WRONG_DIRECTION;
1668 GST_CAT_INFO (GST_CAT_PADS, "src %s:%s was already linked",
1669 GST_DEBUG_PAD_NAME (srcpad));
1670 /* we do not emit a warning in this case because unlinking cannot
1671 * be made MT safe.*/
1672 GST_OBJECT_UNLOCK (srcpad);
1673 return GST_PAD_LINK_WAS_LINKED;
1677 g_critical ("pad %s is not a sink pad", GST_PAD_NAME (sinkpad));
1678 GST_OBJECT_UNLOCK (sinkpad);
1679 GST_OBJECT_UNLOCK (srcpad);
1680 return GST_PAD_LINK_WRONG_DIRECTION;
1684 GST_CAT_INFO (GST_CAT_PADS, "sink %s:%s was already linked",
1685 GST_DEBUG_PAD_NAME (sinkpad));
1686 /* we do not emit a warning in this case because unlinking cannot
1687 * be made MT safe.*/
1688 GST_OBJECT_UNLOCK (sinkpad);
1689 GST_OBJECT_UNLOCK (srcpad);
1690 return GST_PAD_LINK_WAS_LINKED;
1694 GST_CAT_INFO (GST_CAT_PADS, "pads have wrong hierarchy");
1695 GST_OBJECT_UNLOCK (sinkpad);
1696 GST_OBJECT_UNLOCK (srcpad);
1697 return GST_PAD_LINK_WRONG_HIERARCHY;
1701 GST_CAT_INFO (GST_CAT_PADS, "caps are incompatible");
1702 GST_OBJECT_UNLOCK (sinkpad);
1703 GST_OBJECT_UNLOCK (srcpad);
1704 return GST_PAD_LINK_NOFORMAT;
1710 * @srcpad: the source #GstPad to link.
1711 * @sinkpad: the sink #GstPad to link.
1713 * Links the source pad and the sink pad.
1715 * Returns: A result code indicating if the connection worked or
1721 gst_pad_link (GstPad * srcpad, GstPad * sinkpad)
1723 GstPadLinkReturn result;
1725 /* prepare will also lock the two pads */
1726 result = gst_pad_link_prepare (srcpad, sinkpad);
1728 if (result != GST_PAD_LINK_OK)
1729 goto prepare_failed;
1731 /* must set peers before calling the link function */
1732 GST_PAD_PEER (srcpad) = sinkpad;
1733 GST_PAD_PEER (sinkpad) = srcpad;
1735 GST_OBJECT_UNLOCK (sinkpad);
1736 GST_OBJECT_UNLOCK (srcpad);
1738 /* FIXME released the locks here, concurrent thread might link
1739 * something else. */
1740 if (GST_PAD_LINKFUNC (srcpad)) {
1741 /* this one will call the peer link function */
1742 result = GST_PAD_LINKFUNC (srcpad) (srcpad, sinkpad);
1743 } else if (GST_PAD_LINKFUNC (sinkpad)) {
1744 /* if no source link function, we need to call the sink link
1745 * function ourselves. */
1746 result = GST_PAD_LINKFUNC (sinkpad) (sinkpad, srcpad);
1748 result = GST_PAD_LINK_OK;
1751 GST_OBJECT_LOCK (srcpad);
1752 GST_OBJECT_LOCK (sinkpad);
1754 if (result == GST_PAD_LINK_OK) {
1755 GST_OBJECT_UNLOCK (sinkpad);
1756 GST_OBJECT_UNLOCK (srcpad);
1758 /* fire off a signal to each of the pads telling them
1759 * that they've been linked */
1760 g_signal_emit (G_OBJECT (srcpad), gst_pad_signals[PAD_LINKED], 0, sinkpad);
1761 g_signal_emit (G_OBJECT (sinkpad), gst_pad_signals[PAD_LINKED], 0, srcpad);
1763 GST_CAT_INFO (GST_CAT_PADS, "linked %s:%s and %s:%s, successful",
1764 GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (sinkpad));
1766 GST_CAT_INFO (GST_CAT_PADS, "link between %s:%s and %s:%s failed",
1767 GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (sinkpad));
1769 GST_PAD_PEER (srcpad) = NULL;
1770 GST_PAD_PEER (sinkpad) = NULL;
1772 GST_OBJECT_UNLOCK (sinkpad);
1773 GST_OBJECT_UNLOCK (srcpad);
1784 gst_pad_set_pad_template (GstPad * pad, GstPadTemplate * templ)
1786 GstPadTemplate **template_p;
1788 /* this function would need checks if it weren't static */
1790 GST_OBJECT_LOCK (pad);
1791 template_p = &pad->padtemplate;
1792 gst_object_replace ((GstObject **) template_p, (GstObject *) templ);
1793 GST_OBJECT_UNLOCK (pad);
1796 gst_pad_template_pad_created (templ, pad);
1800 * gst_pad_get_pad_template:
1803 * Gets the template for @pad.
1805 * Returns: the #GstPadTemplate from which this pad was instantiated, or %NULL
1806 * if this pad has no template.
1808 * FIXME: currently returns an unrefcounted padtemplate.
1811 gst_pad_get_pad_template (GstPad * pad)
1813 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
1815 return GST_PAD_PAD_TEMPLATE (pad);
1819 /* should be called with the pad LOCK held */
1820 /* refs the caps, so caller is responsible for getting it unreffed */
1822 gst_pad_get_caps_unlocked (GstPad * pad)
1824 GstCaps *result = NULL;
1826 GST_CAT_DEBUG (GST_CAT_CAPS, "get pad caps of %s:%s (%p)",
1827 GST_DEBUG_PAD_NAME (pad), pad);
1829 if (GST_PAD_GETCAPSFUNC (pad)) {
1830 GST_CAT_DEBUG (GST_CAT_CAPS, "dispatching to pad getcaps function");
1832 GST_OBJECT_FLAG_SET (pad, GST_PAD_IN_GETCAPS);
1833 GST_OBJECT_UNLOCK (pad);
1834 result = GST_PAD_GETCAPSFUNC (pad) (pad);
1835 GST_OBJECT_LOCK (pad);
1836 GST_OBJECT_FLAG_UNSET (pad, GST_PAD_IN_GETCAPS);
1838 if (result == NULL) {
1839 g_critical ("pad %s:%s returned NULL caps from getcaps function",
1840 GST_DEBUG_PAD_NAME (pad));
1842 GST_CAT_DEBUG (GST_CAT_CAPS,
1843 "pad getcaps %s:%s returned %" GST_PTR_FORMAT,
1844 GST_DEBUG_PAD_NAME (pad), result);
1845 #ifndef G_DISABLE_ASSERT
1846 /* check that the returned caps are a real subset of the template caps */
1847 if (GST_PAD_PAD_TEMPLATE (pad)) {
1848 const GstCaps *templ_caps =
1849 GST_PAD_TEMPLATE_CAPS (GST_PAD_PAD_TEMPLATE (pad));
1850 if (!gst_caps_is_subset (result, templ_caps)) {
1853 GST_CAT_ERROR_OBJECT (GST_CAT_CAPS, pad,
1854 "pad returned caps %" GST_PTR_FORMAT
1855 " which are not a real subset of its template caps %"
1856 GST_PTR_FORMAT, result, templ_caps);
1858 ("pad %s:%s returned caps that are not a real subset of its template caps",
1859 GST_DEBUG_PAD_NAME (pad));
1860 temp = gst_caps_intersect (templ_caps, result);
1861 gst_caps_unref (result);
1869 if (GST_PAD_PAD_TEMPLATE (pad)) {
1870 GstPadTemplate *templ = GST_PAD_PAD_TEMPLATE (pad);
1872 result = GST_PAD_TEMPLATE_CAPS (templ);
1873 GST_CAT_DEBUG (GST_CAT_CAPS,
1874 "using pad template %p with caps %p %" GST_PTR_FORMAT, templ, result,
1877 result = gst_caps_ref (result);
1880 if (GST_PAD_CAPS (pad)) {
1881 result = GST_PAD_CAPS (pad);
1883 GST_CAT_DEBUG (GST_CAT_CAPS,
1884 "using pad caps %p %" GST_PTR_FORMAT, result, result);
1886 result = gst_caps_ref (result);
1890 GST_CAT_DEBUG (GST_CAT_CAPS, "pad has no caps");
1891 result = gst_caps_new_empty ();
1899 * @pad: a #GstPad to get the capabilities of.
1901 * Gets the capabilities this pad can produce or consume.
1902 * Note that this method doesn't necessarily return the caps set by
1903 * gst_pad_set_caps() - use #GST_PAD_CAPS for that instead.
1904 * gst_pad_get_caps returns all possible caps a pad can operate with, using
1905 * the pad's get_caps function;
1906 * this returns the pad template caps if not explicitly set.
1908 * Returns: a newly allocated copy of the #GstCaps of this pad.
1913 gst_pad_get_caps (GstPad * pad)
1915 GstCaps *result = NULL;
1917 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
1919 GST_OBJECT_LOCK (pad);
1921 GST_CAT_DEBUG (GST_CAT_CAPS, "get pad caps of %s:%s (%p)",
1922 GST_DEBUG_PAD_NAME (pad), pad);
1924 result = gst_pad_get_caps_unlocked (pad);
1925 GST_OBJECT_UNLOCK (pad);
1931 * gst_pad_peer_get_caps:
1932 * @pad: a #GstPad to get the peer capabilities of.
1934 * Gets the capabilities of the peer connected to this pad.
1936 * Returns: the #GstCaps of the peer pad. This function returns a new caps, so use
1937 * gst_caps_unref to get rid of it. this function returns NULL if there is no
1941 gst_pad_peer_get_caps (GstPad * pad)
1944 GstCaps *result = NULL;
1946 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
1948 GST_OBJECT_LOCK (pad);
1950 GST_CAT_DEBUG (GST_CAT_CAPS, "get peer caps of %s:%s (%p)",
1951 GST_DEBUG_PAD_NAME (pad), pad);
1953 peerpad = GST_PAD_PEER (pad);
1954 if (G_UNLIKELY (peerpad == NULL))
1957 gst_object_ref (peerpad);
1958 GST_OBJECT_UNLOCK (pad);
1960 result = gst_pad_get_caps (peerpad);
1962 gst_object_unref (peerpad);
1968 GST_OBJECT_UNLOCK (pad);
1974 fixate_value (GValue * dest, const GValue * src)
1976 if (G_VALUE_TYPE (src) == GST_TYPE_INT_RANGE) {
1977 g_value_init (dest, G_TYPE_INT);
1978 g_value_set_int (dest, gst_value_get_int_range_min (src));
1979 } else if (G_VALUE_TYPE (src) == GST_TYPE_DOUBLE_RANGE) {
1980 g_value_init (dest, G_TYPE_DOUBLE);
1981 g_value_set_double (dest, gst_value_get_double_range_min (src));
1982 } else if (G_VALUE_TYPE (src) == GST_TYPE_FRACTION_RANGE) {
1983 gst_value_init_and_copy (dest, gst_value_get_fraction_range_min (src));
1984 } else if (G_VALUE_TYPE (src) == GST_TYPE_LIST) {
1985 GValue temp = { 0 };
1987 gst_value_init_and_copy (&temp, gst_value_list_get_value (src, 0));
1988 if (!fixate_value (dest, &temp))
1989 gst_value_init_and_copy (dest, &temp);
1990 g_value_unset (&temp);
1991 } else if (G_VALUE_TYPE (src) == GST_TYPE_ARRAY) {
1992 gboolean res = FALSE;
1995 g_value_init (dest, GST_TYPE_ARRAY);
1996 for (n = 0; n < gst_value_array_get_size (src); n++) {
1998 const GValue *orig_kid = gst_value_array_get_value (src, n);
2000 if (!fixate_value (&kid, orig_kid))
2001 gst_value_init_and_copy (&kid, orig_kid);
2004 gst_value_array_append_value (dest, &kid);
2005 g_value_unset (&kid);
2009 g_value_unset (dest);
2020 gst_pad_default_fixate (GQuark field_id, const GValue * value, gpointer data)
2022 GstStructure *s = data;
2025 if (fixate_value (&v, value)) {
2026 gst_structure_id_set_value (s, field_id, &v);
2034 * gst_pad_fixate_caps:
2035 * @pad: a #GstPad to fixate
2036 * @caps: the #GstCaps to fixate
2038 * Fixate a caps on the given pad. Modifies the caps in place, so you should
2039 * make sure that the caps are actually writable (see gst_caps_make_writable()).
2042 gst_pad_fixate_caps (GstPad * pad, GstCaps * caps)
2044 GstPadFixateCapsFunction fixatefunc;
2047 g_return_if_fail (GST_IS_PAD (pad));
2048 g_return_if_fail (caps != NULL);
2050 if (gst_caps_is_fixed (caps))
2053 fixatefunc = GST_PAD_FIXATECAPSFUNC (pad);
2055 fixatefunc (pad, caps);
2058 /* default fixation */
2059 for (n = 0; n < gst_caps_get_size (caps); n++) {
2060 GstStructure *s = gst_caps_get_structure (caps, n);
2062 gst_structure_foreach (s, gst_pad_default_fixate, s);
2066 /* Default accept caps implementation just checks against
2067 * against the allowed caps for the pad */
2069 gst_pad_acceptcaps_default (GstPad * pad, GstCaps * caps)
2071 /* get the caps and see if it intersects to something
2075 gboolean result = FALSE;
2077 allowed = gst_pad_get_caps (pad);
2079 intersect = gst_caps_intersect (allowed, caps);
2081 result = !gst_caps_is_empty (intersect);
2083 gst_caps_unref (allowed);
2084 gst_caps_unref (intersect);
2091 * gst_pad_accept_caps:
2092 * @pad: a #GstPad to check
2093 * @caps: a #GstCaps to check on the pad
2095 * Check if the given pad accepts the caps.
2097 * Returns: TRUE if the pad can accept the caps.
2100 gst_pad_accept_caps (GstPad * pad, GstCaps * caps)
2103 GstPadAcceptCapsFunction acceptfunc;
2104 GstCaps *existing = NULL;
2106 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2108 /* any pad can be unnegotiated */
2112 GST_OBJECT_LOCK (pad);
2113 acceptfunc = GST_PAD_ACCEPTCAPSFUNC (pad);
2114 if (GST_PAD_CAPS (pad) != NULL)
2115 existing = gst_caps_ref (GST_PAD_CAPS (pad));
2117 GST_CAT_DEBUG (GST_CAT_CAPS, "pad accept caps of %s:%s (%p)",
2118 GST_DEBUG_PAD_NAME (pad), pad);
2119 GST_OBJECT_UNLOCK (pad);
2121 /* The current caps on a pad are trivially acceptable */
2123 if (caps == existing || gst_caps_is_equal (caps, existing))
2125 gst_caps_unref (existing);
2128 if (G_LIKELY (acceptfunc)) {
2129 /* we can call the function */
2130 result = acceptfunc (pad, caps);
2132 /* Only null if the element explicitly unset it */
2133 result = gst_pad_acceptcaps_default (pad, caps);
2138 gst_caps_unref (existing);
2143 * gst_pad_peer_accept_caps:
2144 * @pad: a #GstPad to check
2145 * @caps: a #GstCaps to check on the pad
2147 * Check if the given pad accepts the caps.
2149 * Returns: TRUE if the pad can accept the caps.
2152 gst_pad_peer_accept_caps (GstPad * pad, GstCaps * caps)
2157 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2159 GST_OBJECT_LOCK (pad);
2161 GST_CAT_DEBUG (GST_CAT_CAPS, "peer accept caps of %s:%s (%p)",
2162 GST_DEBUG_PAD_NAME (pad), pad);
2164 peerpad = GST_PAD_PEER (pad);
2165 if (G_UNLIKELY (peerpad == NULL))
2168 result = gst_pad_accept_caps (peerpad, caps);
2169 GST_OBJECT_UNLOCK (pad);
2175 GST_OBJECT_UNLOCK (pad);
2182 * @pad: a #GstPad to set the capabilities of.
2183 * @caps: a #GstCaps to set.
2185 * Sets the capabilities of this pad. The caps must be fixed. Any previous
2186 * caps on the pad will be unreffed. This function refs the caps so you should
2187 * unref if as soon as you don't need it anymore.
2188 * It is possible to set NULL caps, which will make the pad unnegotiated
2191 * Returns: TRUE if the caps could be set. FALSE if the caps were not fixed
2192 * or bad parameters were provided to this function.
2197 gst_pad_set_caps (GstPad * pad, GstCaps * caps)
2199 GstPadSetCapsFunction setcaps;
2202 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2203 g_return_val_if_fail (caps == NULL || gst_caps_is_fixed (caps), FALSE);
2205 GST_OBJECT_LOCK (pad);
2206 setcaps = GST_PAD_SETCAPSFUNC (pad);
2208 existing = GST_PAD_CAPS (pad);
2209 if (existing == caps) {
2210 GST_OBJECT_UNLOCK (pad);
2214 if (gst_caps_is_equal (caps, existing))
2215 goto setting_same_caps;
2217 /* call setcaps function to configure the pad only if the
2218 * caps is not NULL */
2219 if (setcaps != NULL && caps) {
2220 if (!GST_PAD_IS_IN_SETCAPS (pad)) {
2221 GST_OBJECT_FLAG_SET (pad, GST_PAD_IN_SETCAPS);
2222 GST_OBJECT_UNLOCK (pad);
2223 if (!setcaps (pad, caps))
2225 GST_OBJECT_LOCK (pad);
2226 GST_OBJECT_FLAG_UNSET (pad, GST_PAD_IN_SETCAPS);
2228 GST_CAT_DEBUG (GST_CAT_CAPS, "pad %s:%s was dispatching",
2229 GST_DEBUG_PAD_NAME (pad));
2233 gst_caps_replace (&GST_PAD_CAPS (pad), caps);
2234 GST_CAT_DEBUG (GST_CAT_CAPS, "%s:%s caps %" GST_PTR_FORMAT,
2235 GST_DEBUG_PAD_NAME (pad), caps);
2236 GST_OBJECT_UNLOCK (pad);
2238 g_object_notify (G_OBJECT (pad), "caps");
2244 gst_caps_replace (&GST_PAD_CAPS (pad), caps);
2245 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
2246 "caps %" GST_PTR_FORMAT " same as existing, updating ptr only", caps);
2247 GST_OBJECT_UNLOCK (pad);
2254 GST_OBJECT_LOCK (pad);
2255 GST_OBJECT_FLAG_UNSET (pad, GST_PAD_IN_SETCAPS);
2256 GST_CAT_DEBUG (GST_CAT_CAPS,
2257 "pad %s:%s, caps %" GST_PTR_FORMAT " could not be set",
2258 GST_DEBUG_PAD_NAME (pad), caps);
2259 GST_OBJECT_UNLOCK (pad);
2266 gst_pad_configure_sink (GstPad * pad, GstCaps * caps)
2268 GstPadSetCapsFunction setcaps;
2271 setcaps = GST_PAD_SETCAPSFUNC (pad);
2273 /* See if pad accepts the caps - only needed if
2274 * no setcaps function */
2275 if (setcaps == NULL)
2276 if (!gst_pad_accept_caps (pad, caps))
2279 /* set caps on pad if call succeeds */
2280 res = gst_pad_set_caps (pad, caps);
2281 /* no need to unref the caps here, set_caps takes a ref and
2282 * our ref goes away when we leave this function. */
2288 GST_CAT_DEBUG (GST_CAT_CAPS, "caps %" GST_PTR_FORMAT " not accepted", caps);
2293 /* returns TRUE if the src pad could be configured to accept the given caps */
2295 gst_pad_configure_src (GstPad * pad, GstCaps * caps, gboolean dosetcaps)
2297 GstPadSetCapsFunction setcaps;
2300 setcaps = GST_PAD_SETCAPSFUNC (pad);
2302 /* See if pad accepts the caps - only needed if
2303 * no setcaps function */
2304 if (setcaps == NULL)
2305 if (!gst_pad_accept_caps (pad, caps))
2309 res = gst_pad_set_caps (pad, caps);
2317 GST_CAT_DEBUG (GST_CAT_CAPS, "caps %" GST_PTR_FORMAT " not accepted", caps);
2323 * gst_pad_get_pad_template_caps:
2324 * @pad: a #GstPad to get the template capabilities from.
2326 * Gets the capabilities for @pad's template.
2328 * Returns: the #GstCaps of this pad template. If you intend to keep a reference
2329 * on the caps, make a copy (see gst_caps_copy ()).
2332 gst_pad_get_pad_template_caps (GstPad * pad)
2334 static GstStaticCaps anycaps = GST_STATIC_CAPS ("ANY");
2336 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2338 if (GST_PAD_PAD_TEMPLATE (pad))
2339 return GST_PAD_TEMPLATE_CAPS (GST_PAD_PAD_TEMPLATE (pad));
2341 return gst_static_caps_get (&anycaps);
2347 * @pad: a #GstPad to get the peer of.
2349 * Gets the peer of @pad. This function refs the peer pad so
2350 * you need to unref it after use.
2352 * Returns: the peer #GstPad. Unref after usage.
2357 gst_pad_get_peer (GstPad * pad)
2361 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2363 GST_OBJECT_LOCK (pad);
2364 result = GST_PAD_PEER (pad);
2366 gst_object_ref (result);
2367 GST_OBJECT_UNLOCK (pad);
2373 * gst_pad_get_allowed_caps:
2374 * @srcpad: a #GstPad, it must a a source pad.
2376 * Gets the capabilities of the allowed media types that can flow through
2377 * @srcpad and its peer. The pad must be a source pad.
2378 * The caller must free the resulting caps.
2380 * Returns: the allowed #GstCaps of the pad link. Free the caps when
2381 * you no longer need it. This function returns NULL when the @srcpad has no
2387 gst_pad_get_allowed_caps (GstPad * srcpad)
2394 g_return_val_if_fail (GST_IS_PAD (srcpad), NULL);
2395 g_return_val_if_fail (GST_PAD_IS_SRC (srcpad), NULL);
2397 GST_OBJECT_LOCK (srcpad);
2399 peer = GST_PAD_PEER (srcpad);
2400 if (G_UNLIKELY (peer == NULL))
2403 GST_CAT_DEBUG (GST_CAT_PROPERTIES, "%s:%s: getting allowed caps",
2404 GST_DEBUG_PAD_NAME (srcpad));
2406 gst_object_ref (peer);
2407 GST_OBJECT_UNLOCK (srcpad);
2408 mycaps = gst_pad_get_caps (srcpad);
2410 peercaps = gst_pad_get_caps (peer);
2411 gst_object_unref (peer);
2413 caps = gst_caps_intersect (mycaps, peercaps);
2414 gst_caps_unref (peercaps);
2415 gst_caps_unref (mycaps);
2417 GST_CAT_DEBUG (GST_CAT_CAPS, "allowed caps %" GST_PTR_FORMAT, caps);
2423 GST_CAT_DEBUG (GST_CAT_PROPERTIES, "%s:%s: no peer",
2424 GST_DEBUG_PAD_NAME (srcpad));
2425 GST_OBJECT_UNLOCK (srcpad);
2432 * gst_pad_get_negotiated_caps:
2435 * Gets the capabilities of the media type that currently flows through @pad
2438 * This function can be used on both src and sinkpads. Note that srcpads are
2439 * always negotiated before sinkpads so it is possible that the negotiated caps
2440 * on the srcpad do not match the negotiated caps of the peer.
2442 * Returns: the negotiated #GstCaps of the pad link. Free the caps when
2443 * you no longer need it. This function returns NULL when the @pad has no
2444 * peer or is not negotiated yet.
2449 gst_pad_get_negotiated_caps (GstPad * pad)
2454 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2456 GST_OBJECT_LOCK (pad);
2458 if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
2461 GST_CAT_DEBUG (GST_CAT_PROPERTIES, "%s:%s: getting negotiated caps",
2462 GST_DEBUG_PAD_NAME (pad));
2464 caps = GST_PAD_CAPS (pad);
2466 gst_caps_ref (caps);
2467 GST_OBJECT_UNLOCK (pad);
2469 GST_CAT_DEBUG (GST_CAT_CAPS, "negotiated caps %" GST_PTR_FORMAT, caps);
2475 GST_CAT_DEBUG (GST_CAT_PROPERTIES, "%s:%s: no peer",
2476 GST_DEBUG_PAD_NAME (pad));
2477 GST_OBJECT_UNLOCK (pad);
2483 static GstFlowReturn
2484 gst_pad_alloc_buffer_full (GstPad * pad, guint64 offset, gint size,
2485 GstCaps * caps, GstBuffer ** buf, gboolean setcaps)
2489 GstPadBufferAllocFunction bufferallocfunc;
2490 gboolean caps_changed;
2492 g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
2493 g_return_val_if_fail (GST_PAD_IS_SRC (pad), GST_FLOW_ERROR);
2494 g_return_val_if_fail (buf != NULL, GST_FLOW_ERROR);
2496 GST_OBJECT_LOCK (pad);
2497 while (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad)))
2498 if ((ret = handle_pad_block (pad)) != GST_FLOW_OK)
2501 if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
2504 gst_object_ref (peer);
2505 GST_OBJECT_UNLOCK (pad);
2507 if (G_LIKELY ((bufferallocfunc = peer->bufferallocfunc) == NULL))
2510 GST_OBJECT_LOCK (peer);
2511 /* when the peer is flushing we cannot give a buffer */
2512 if (G_UNLIKELY (GST_PAD_IS_FLUSHING (peer)))
2515 if (offset == GST_BUFFER_OFFSET_NONE) {
2516 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
2517 "calling bufferallocfunc &%s (@%p) of peer pad %s:%s for size %d offset NONE",
2518 GST_DEBUG_FUNCPTR_NAME (bufferallocfunc),
2519 &bufferallocfunc, GST_DEBUG_PAD_NAME (peer), size);
2521 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
2522 "calling bufferallocfunc &%s (@%p) of peer pad %s:%s for size %d offset %"
2523 G_GUINT64_FORMAT, GST_DEBUG_FUNCPTR_NAME (bufferallocfunc),
2524 &bufferallocfunc, GST_DEBUG_PAD_NAME (peer), size, offset);
2526 GST_OBJECT_UNLOCK (peer);
2528 ret = bufferallocfunc (peer, offset, size, caps, buf);
2530 if (G_UNLIKELY (ret != GST_FLOW_OK))
2532 if (G_UNLIKELY (*buf == NULL))
2535 /* If the buffer alloc function didn't set up the caps like it should,
2537 if (caps && (GST_BUFFER_CAPS (*buf) == NULL)) {
2538 GST_WARNING ("Buffer allocation function for pad % " GST_PTR_FORMAT
2539 " did not set up caps. Setting", peer);
2541 gst_buffer_set_caps (*buf, caps);
2545 gst_object_unref (peer);
2547 /* FIXME, move capnego this into a base class? */
2548 caps = GST_BUFFER_CAPS (*buf);
2549 caps_changed = caps && caps != GST_PAD_CAPS (pad);
2550 /* we got a new datatype on the pad, see if it can handle it */
2551 if (G_UNLIKELY (caps_changed)) {
2552 GST_DEBUG_OBJECT (pad, "caps changed to %" GST_PTR_FORMAT, caps);
2553 if (G_UNLIKELY (!gst_pad_configure_src (pad, caps, setcaps)))
2554 goto not_negotiated;
2560 GST_CAT_DEBUG (GST_CAT_PADS, "%s:%s pad block stopped by flush",
2561 GST_DEBUG_PAD_NAME (pad));
2562 GST_OBJECT_UNLOCK (pad);
2567 /* pad has no peer */
2568 GST_CAT_DEBUG (GST_CAT_PADS,
2569 "%s:%s called bufferallocfunc but had no peer",
2570 GST_DEBUG_PAD_NAME (pad));
2571 GST_OBJECT_UNLOCK (pad);
2572 return GST_FLOW_NOT_LINKED;
2576 /* peer was flushing */
2577 GST_OBJECT_UNLOCK (peer);
2578 gst_object_unref (peer);
2579 GST_CAT_DEBUG (GST_CAT_PADS,
2580 "%s:%s called bufferallocfunc but peer was flushing",
2581 GST_DEBUG_PAD_NAME (pad));
2582 return GST_FLOW_WRONG_STATE;
2584 /* fallback case, allocate a buffer of our own, add pad caps. */
2587 GST_CAT_DEBUG (GST_CAT_PADS,
2588 "%s:%s fallback buffer alloc", GST_DEBUG_PAD_NAME (pad));
2589 *buf = gst_buffer_new_and_alloc (size);
2590 GST_BUFFER_OFFSET (*buf) = offset;
2591 gst_buffer_set_caps (*buf, caps);
2599 gst_buffer_unref (*buf);
2601 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
2602 "alloc function returned unacceptable buffer");
2603 return GST_FLOW_NOT_NEGOTIATED;
2607 gst_object_unref (peer);
2608 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
2609 "alloc function returned error %s", gst_flow_get_name (ret));
2615 * gst_pad_alloc_buffer:
2616 * @pad: a source #GstPad
2617 * @offset: the offset of the new buffer in the stream
2618 * @size: the size of the new buffer
2619 * @caps: the caps of the new buffer
2620 * @buf: a newly allocated buffer
2622 * Allocates a new, empty buffer optimized to push to pad @pad. This
2623 * function only works if @pad is a source pad and has a peer.
2625 * You need to check the caps of the buffer after performing this
2626 * function and renegotiate to the format if needed.
2628 * A new, empty #GstBuffer will be put in the @buf argument.
2630 * Returns: a result code indicating success of the operation. Any
2631 * result code other than GST_FLOW_OK is an error and @buf should
2633 * An error can occur if the pad is not connected or when the downstream
2634 * peer elements cannot provide an acceptable buffer.
2639 gst_pad_alloc_buffer (GstPad * pad, guint64 offset, gint size, GstCaps * caps,
2642 return gst_pad_alloc_buffer_full (pad, offset, size, caps, buf, FALSE);
2646 * gst_pad_alloc_buffer_and_set_caps:
2647 * @pad: a source #GstPad
2648 * @offset: the offset of the new buffer in the stream
2649 * @size: the size of the new buffer
2650 * @caps: the caps of the new buffer
2651 * @buf: a newly allocated buffer
2653 * In addition to the function gst_pad_alloc_buffer(), this function
2654 * automatically calls gst_pad_set_caps() when the caps of the
2655 * newly allocated buffer are different from the @pad caps.
2657 * Returns: a result code indicating success of the operation. Any
2658 * result code other than GST_FLOW_OK is an error and @buf should
2660 * An error can occur if the pad is not connected or when the downstream
2661 * peer elements cannot provide an acceptable buffer.
2666 gst_pad_alloc_buffer_and_set_caps (GstPad * pad, guint64 offset, gint size,
2667 GstCaps * caps, GstBuffer ** buf)
2669 return gst_pad_alloc_buffer_full (pad, offset, size, caps, buf, TRUE);
2673 * gst_pad_get_internal_links_default:
2674 * @pad: the #GstPad to get the internal links of.
2676 * Gets a list of pads to which the given pad is linked to
2677 * inside of the parent element.
2678 * This is the default handler, and thus returns a list of all of the
2679 * pads inside the parent element with opposite direction.
2680 * The caller must free this list after use.
2682 * Returns: a newly allocated #GList of pads, or NULL if the pad has no parent.
2687 gst_pad_get_internal_links_default (GstPad * pad)
2692 GstPadDirection direction;
2694 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2696 direction = pad->direction;
2698 parent = GST_PAD_PARENT (pad);
2702 parent_pads = parent->pads;
2704 while (parent_pads) {
2705 GstPad *parent_pad = GST_PAD_CAST (parent_pads->data);
2707 if (parent_pad->direction != direction) {
2708 res = g_list_prepend (res, parent_pad);
2711 parent_pads = g_list_next (parent_pads);
2718 * gst_pad_get_internal_links:
2719 * @pad: the #GstPad to get the internal links of.
2721 * Gets a list of pads to which the given pad is linked to
2722 * inside of the parent element.
2723 * The caller must free this list after use.
2725 * Returns: a newly allocated #GList of pads.
2730 gst_pad_get_internal_links (GstPad * pad)
2734 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2736 if (GST_PAD_INTLINKFUNC (pad))
2737 res = GST_PAD_INTLINKFUNC (pad) (pad);
2744 gst_pad_event_default_dispatch (GstPad * pad, GstEvent * event)
2749 GST_INFO_OBJECT (pad, "Sending event %p to all internally linked pads",
2752 result = (GST_PAD_DIRECTION (pad) == GST_PAD_SINK);
2754 orig = pads = gst_pad_get_internal_links (pad);
2757 GstPad *eventpad = GST_PAD_CAST (pads->data);
2759 pads = g_list_next (pads);
2761 if (GST_PAD_DIRECTION (eventpad) == GST_PAD_SRC) {
2762 /* for each pad we send to, we should ref the event; it's up
2763 * to downstream to unref again when handled. */
2764 GST_LOG_OBJECT (pad, "Reffing and sending event %p (%s) to %s:%s",
2765 event, GST_EVENT_TYPE_NAME (event), GST_DEBUG_PAD_NAME (eventpad));
2766 gst_event_ref (event);
2767 gst_pad_push_event (eventpad, event);
2769 /* we only send the event on one pad, multi-sinkpad elements
2770 * should implement a handler */
2771 GST_LOG_OBJECT (pad, "sending event %p (%s) to one sink pad %s:%s",
2772 event, GST_EVENT_TYPE_NAME (event), GST_DEBUG_PAD_NAME (eventpad));
2773 result = gst_pad_push_event (eventpad, event);
2777 /* we handled the incoming event so we unref once */
2778 GST_LOG_OBJECT (pad, "handled event %p, unreffing", event);
2779 gst_event_unref (event);
2788 * gst_pad_event_default:
2789 * @pad: a #GstPad to call the default event handler on.
2790 * @event: the #GstEvent to handle.
2792 * Invokes the default event handler for the given pad. End-of-stream and
2793 * discontinuity events are handled specially, and then the event is sent to all
2794 * pads internally linked to @pad. Note that if there are many possible sink
2795 * pads that are internally linked to @pad, only one will be sent an event.
2796 * Multi-sinkpad elements should implement custom event handlers.
2798 * Returns: TRUE if the event was sent succesfully.
2801 gst_pad_event_default (GstPad * pad, GstEvent * event)
2803 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2804 g_return_val_if_fail (event != NULL, FALSE);
2806 switch (GST_EVENT_TYPE (event)) {
2809 GST_DEBUG_OBJECT (pad, "pausing task because of eos");
2810 gst_pad_pause_task (pad);
2816 return gst_pad_event_default_dispatch (pad, event);
2820 * gst_pad_dispatcher:
2821 * @pad: a #GstPad to dispatch.
2822 * @dispatch: the #GstDispatcherFunction to call.
2823 * @data: gpointer user data passed to the dispatcher function.
2825 * Invokes the given dispatcher function on all pads that are
2826 * internally linked to the given pad.
2827 * The GstPadDispatcherFunction should return TRUE when no further pads
2828 * need to be processed.
2830 * Returns: TRUE if one of the dispatcher functions returned TRUE.
2833 gst_pad_dispatcher (GstPad * pad, GstPadDispatcherFunction dispatch,
2836 gboolean res = FALSE;
2837 GList *int_pads, *orig;
2839 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2840 g_return_val_if_fail (dispatch != NULL, FALSE);
2842 orig = int_pads = gst_pad_get_internal_links (pad);
2845 GstPad *int_pad = GST_PAD_CAST (int_pads->data);
2846 GstPad *int_peer = GST_PAD_PEER (int_pad);
2849 res = dispatch (int_peer, data);
2853 int_pads = g_list_next (int_pads);
2863 * @pad: a #GstPad to invoke the default query on.
2864 * @query: the #GstQuery to perform.
2866 * Dispatches a query to a pad. The query should have been allocated by the
2867 * caller via one of the type-specific allocation functions in gstquery.h. The
2868 * element is responsible for filling the query with an appropriate response,
2869 * which should then be parsed with a type-specific query parsing function.
2871 * Again, the caller is responsible for both the allocation and deallocation of
2872 * the query structure.
2874 * Returns: TRUE if the query could be performed.
2877 gst_pad_query (GstPad * pad, GstQuery * query)
2879 GstPadQueryFunction func;
2881 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2882 g_return_val_if_fail (GST_IS_QUERY (query), FALSE);
2884 GST_DEBUG ("sending query %p to pad %s:%s", query, GST_DEBUG_PAD_NAME (pad));
2886 if ((func = GST_PAD_QUERYFUNC (pad)) == NULL)
2889 return func (pad, query);
2893 GST_DEBUG ("pad had no query function");
2899 * gst_pad_query_default:
2900 * @pad: a #GstPad to call the default query handler on.
2901 * @query: the #GstQuery to handle.
2903 * Invokes the default query handler for the given pad.
2904 * The query is sent to all pads internally linked to @pad. Note that
2905 * if there are many possible sink pads that are internally linked to
2906 * @pad, only one will be sent the query.
2907 * Multi-sinkpad elements should implement custom query handlers.
2909 * Returns: TRUE if the query was performed succesfully.
2912 gst_pad_query_default (GstPad * pad, GstQuery * query)
2914 switch (GST_QUERY_TYPE (query)) {
2915 case GST_QUERY_POSITION:
2916 case GST_QUERY_SEEKING:
2917 case GST_QUERY_FORMATS:
2918 case GST_QUERY_LATENCY:
2919 case GST_QUERY_JITTER:
2920 case GST_QUERY_RATE:
2921 case GST_QUERY_CONVERT:
2923 return gst_pad_dispatcher
2924 (pad, (GstPadDispatcherFunction) gst_pad_query, query);
2928 #ifndef GST_DISABLE_LOADSAVE
2929 /* FIXME: why isn't this on a GstElement ? */
2931 * gst_pad_load_and_link:
2932 * @self: an #xmlNodePtr to read the description from.
2933 * @parent: the #GstObject element that owns the pad.
2935 * Reads the pad definition from the XML node and links the given pad
2936 * in the element to a pad of an element up in the hierarchy.
2939 gst_pad_load_and_link (xmlNodePtr self, GstObject * parent)
2941 xmlNodePtr field = self->xmlChildrenNode;
2942 GstPad *pad = NULL, *targetpad;
2946 GstObject *grandparent;
2950 if (!strcmp ((char *) field->name, "name")) {
2951 name = (gchar *) xmlNodeGetContent (field);
2952 pad = gst_element_get_pad (GST_ELEMENT (parent), name);
2954 } else if (!strcmp ((char *) field->name, "peer")) {
2955 peer = (gchar *) xmlNodeGetContent (field);
2957 field = field->next;
2959 g_return_if_fail (pad != NULL);
2964 split = g_strsplit (peer, ".", 2);
2966 if (split[0] == NULL || split[1] == NULL) {
2967 GST_CAT_DEBUG (GST_CAT_XML,
2968 "Could not parse peer '%s' for pad %s:%s, leaving unlinked",
2969 peer, GST_DEBUG_PAD_NAME (pad));
2976 g_return_if_fail (split[0] != NULL);
2977 g_return_if_fail (split[1] != NULL);
2979 grandparent = gst_object_get_parent (parent);
2981 if (grandparent && GST_IS_BIN (grandparent)) {
2982 target = gst_bin_get_by_name_recurse_up (GST_BIN (grandparent), split[0]);
2989 targetpad = gst_element_get_pad (target, split[1]);
2991 if (targetpad == NULL)
2994 gst_pad_link (pad, targetpad);
3001 * gst_pad_save_thyself:
3002 * @pad: a #GstPad to save.
3003 * @parent: the parent #xmlNodePtr to save the description in.
3005 * Saves the pad into an xml representation.
3007 * Returns: the #xmlNodePtr representation of the pad.
3010 gst_pad_save_thyself (GstObject * object, xmlNodePtr parent)
3015 g_return_val_if_fail (GST_IS_PAD (object), NULL);
3017 pad = GST_PAD (object);
3019 xmlNewChild (parent, NULL, (xmlChar *) "name",
3020 (xmlChar *) GST_PAD_NAME (pad));
3021 if (GST_PAD_PEER (pad) != NULL) {
3024 peer = GST_PAD_PEER (pad);
3025 /* first check to see if the peer's parent's parent is the same */
3026 /* we just save it off */
3027 content = g_strdup_printf ("%s.%s",
3028 GST_OBJECT_NAME (GST_PAD_PARENT (peer)), GST_PAD_NAME (peer));
3029 xmlNewChild (parent, NULL, (xmlChar *) "peer", (xmlChar *) content);
3032 xmlNewChild (parent, NULL, (xmlChar *) "peer", NULL);
3039 * gst_ghost_pad_save_thyself:
3040 * @pad: a ghost #GstPad to save.
3041 * @parent: the parent #xmlNodePtr to save the description in.
3043 * Saves the ghost pad into an xml representation.
3045 * Returns: the #xmlNodePtr representation of the pad.
3048 gst_ghost_pad_save_thyself (GstPad * pad, xmlNodePtr parent)
3052 g_return_val_if_fail (GST_IS_GHOST_PAD (pad), NULL);
3054 self = xmlNewChild (parent, NULL, (xmlChar *) "ghostpad", NULL);
3055 xmlNewChild (self, NULL, (xmlChar *) "name", (xmlChar *) GST_PAD_NAME (pad));
3056 xmlNewChild (self, NULL, (xmlChar *) "parent",
3057 (xmlChar *) GST_OBJECT_NAME (GST_PAD_PARENT (pad)));
3059 /* FIXME FIXME FIXME! */
3064 #endif /* GST_DISABLE_LOADSAVE */
3067 * should be called with pad lock held
3071 static GstFlowReturn
3072 handle_pad_block (GstPad * pad)
3074 GstPadBlockCallback callback;
3076 GstFlowReturn ret = GST_FLOW_OK;
3078 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3079 "signal block taken on pad %s:%s", GST_DEBUG_PAD_NAME (pad));
3081 /* need to grab extra ref for the callbacks */
3082 gst_object_ref (pad);
3084 callback = pad->block_callback;
3086 user_data = pad->block_data;
3087 GST_OBJECT_UNLOCK (pad);
3088 callback (pad, TRUE, user_data);
3089 GST_OBJECT_LOCK (pad);
3091 GST_PAD_BLOCK_SIGNAL (pad);
3094 while (GST_PAD_IS_BLOCKED (pad)) {
3095 if (GST_PAD_IS_FLUSHING (pad))
3097 GST_PAD_BLOCK_WAIT (pad);
3098 if (GST_PAD_IS_FLUSHING (pad))
3102 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "got unblocked");
3104 callback = pad->block_callback;
3106 user_data = pad->block_data;
3107 GST_OBJECT_UNLOCK (pad);
3108 callback (pad, FALSE, user_data);
3109 GST_OBJECT_LOCK (pad);
3111 GST_PAD_BLOCK_SIGNAL (pad);
3114 gst_object_unref (pad);
3120 gst_object_unref (pad);
3121 return GST_FLOW_WRONG_STATE;
3125 /**********************************************************************
3126 * Data passing functions
3130 gst_pad_emit_have_data_signal (GstPad * pad, GstMiniObject * obj)
3133 GValue args[2] = { {0}, {0} };
3138 g_value_init (&ret, G_TYPE_BOOLEAN);
3139 g_value_set_boolean (&ret, TRUE);
3140 g_value_init (&args[0], GST_TYPE_PAD);
3141 g_value_set_object (&args[0], pad);
3142 g_value_init (&args[1], GST_TYPE_MINI_OBJECT); // G_TYPE_POINTER);
3143 gst_value_set_mini_object (&args[1], obj);
3145 if (GST_IS_EVENT (obj))
3146 detail = event_quark;
3148 detail = buffer_quark;
3151 g_signal_emitv (args, gst_pad_signals[PAD_HAVE_DATA], detail, &ret);
3152 res = g_value_get_boolean (&ret);
3155 g_value_unset (&ret);
3156 g_value_unset (&args[0]);
3157 g_value_unset (&args[1]);
3164 * @pad: a sink #GstPad.
3165 * @buffer: the #GstBuffer to send.
3167 * Chain a buffer to @pad.
3169 * Returns: a #GstFlowReturn from the pad.
3174 gst_pad_chain (GstPad * pad, GstBuffer * buffer)
3177 gboolean caps_changed;
3178 GstPadChainFunction chainfunc;
3180 gboolean emit_signal;
3182 g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
3183 g_return_val_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SINK,
3185 g_return_val_if_fail (buffer != NULL, GST_FLOW_ERROR);
3186 g_return_val_if_fail (GST_IS_BUFFER (buffer), GST_FLOW_ERROR);
3188 GST_PAD_STREAM_LOCK (pad);
3190 GST_OBJECT_LOCK (pad);
3191 if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad)))
3194 caps = GST_BUFFER_CAPS (buffer);
3195 caps_changed = caps && caps != GST_PAD_CAPS (pad);
3197 emit_signal = GST_PAD_DO_BUFFER_SIGNALS (pad) > 0;
3198 GST_OBJECT_UNLOCK (pad);
3200 /* see if the signal should be emited, we emit before caps nego as
3201 * we might drop the buffer and do capsnego for nothing. */
3202 if (G_UNLIKELY (emit_signal)) {
3203 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (buffer)))
3207 /* we got a new datatype on the pad, see if it can handle it */
3208 if (G_UNLIKELY (caps_changed)) {
3209 GST_DEBUG_OBJECT (pad, "caps changed to %" GST_PTR_FORMAT, caps);
3210 if (G_UNLIKELY (!gst_pad_configure_sink (pad, caps)))
3211 goto not_negotiated;
3214 /* NOTE: we read the chainfunc unlocked.
3215 * we cannot hold the lock for the pad so we might send
3216 * the data to the wrong function. This is not really a
3217 * problem since functions are assigned at creation time
3218 * and don't change that often... */
3219 if (G_UNLIKELY ((chainfunc = GST_PAD_CHAINFUNC (pad)) == NULL))
3222 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3223 "calling chainfunction &%s of pad %s:%s",
3224 GST_DEBUG_FUNCPTR_NAME (chainfunc), GST_DEBUG_PAD_NAME (pad));
3226 ret = chainfunc (pad, buffer);
3228 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3229 "called chainfunction &%s of pad %s:%s, returned %s",
3230 GST_DEBUG_FUNCPTR_NAME (chainfunc), GST_DEBUG_PAD_NAME (pad),
3231 gst_flow_get_name (ret));
3233 GST_PAD_STREAM_UNLOCK (pad);
3240 gst_buffer_unref (buffer);
3241 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3242 "pushing, but pad was flushing");
3243 GST_OBJECT_UNLOCK (pad);
3244 GST_PAD_STREAM_UNLOCK (pad);
3245 return GST_FLOW_WRONG_STATE;
3249 gst_buffer_unref (buffer);
3250 GST_DEBUG_OBJECT (pad, "Dropping buffer due to FALSE probe return");
3251 GST_PAD_STREAM_UNLOCK (pad);
3256 gst_buffer_unref (buffer);
3257 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3258 "pushing buffer but pad did not accept");
3259 GST_PAD_STREAM_UNLOCK (pad);
3260 return GST_FLOW_NOT_NEGOTIATED;
3264 gst_buffer_unref (buffer);
3265 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3266 "pushing, but not chainhandler");
3267 GST_ELEMENT_ERROR (GST_PAD_PARENT (pad), CORE, PAD, (NULL),
3268 ("push on pad %s:%s but it has no chainfunction",
3269 GST_DEBUG_PAD_NAME (pad)));
3270 GST_PAD_STREAM_UNLOCK (pad);
3271 return GST_FLOW_ERROR;
3277 * @pad: a source #GstPad.
3278 * @buffer: the #GstBuffer to push.
3280 * Pushes a buffer to the peer of @pad. This gives away your reference to
3282 * Buffer probes will be triggered before the buffer gets pushed.
3284 * Returns: a #GstFlowReturn from the peer pad.
3289 gst_pad_push (GstPad * pad, GstBuffer * buffer)
3295 gboolean caps_changed;
3297 g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
3298 g_return_val_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SRC, GST_FLOW_ERROR);
3299 g_return_val_if_fail (buffer != NULL, GST_FLOW_ERROR);
3300 g_return_val_if_fail (GST_IS_BUFFER (buffer), GST_FLOW_ERROR);
3302 GST_OBJECT_LOCK (pad);
3304 /* FIXME: this check can go away; pad_set_blocked could be implemented with
3305 * probes completely */
3306 while (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad)))
3307 if ((ret = handle_pad_block (pad)) != GST_FLOW_OK)
3310 /* we emit signals on the pad arg, the peer will have a chance to
3311 * emit in the _chain() function */
3312 if (G_UNLIKELY (GST_PAD_DO_BUFFER_SIGNALS (pad) > 0)) {
3313 /* unlock before emitting */
3314 GST_OBJECT_UNLOCK (pad);
3316 /* if the signal handler returned FALSE, it means we should just drop the
3318 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (buffer)))
3321 GST_OBJECT_LOCK (pad);
3324 if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
3326 gst_object_ref (peer);
3328 /* Before pushing the buffer to the peer pad, ensure that caps
3329 * are set on this pad */
3330 caps = GST_BUFFER_CAPS (buffer);
3331 caps_changed = caps && caps != GST_PAD_CAPS (pad);
3333 GST_OBJECT_UNLOCK (pad);
3335 /* we got a new datatype from the pad, it had better handle it */
3336 if (G_UNLIKELY (caps_changed)) {
3337 GST_DEBUG_OBJECT (pad, "caps changed to %" GST_PTR_FORMAT, caps);
3338 if (G_UNLIKELY (!gst_pad_configure_src (pad, caps, TRUE)))
3339 goto not_negotiated;
3342 ret = gst_pad_chain (peer, buffer);
3344 gst_object_unref (peer);
3348 /* ERROR recovery here */
3351 gst_buffer_unref (buffer);
3352 GST_DEBUG_OBJECT (pad, "pad block stopped by flush");
3353 GST_OBJECT_UNLOCK (pad);
3358 gst_buffer_unref (buffer);
3359 GST_DEBUG_OBJECT (pad, "Dropping buffer due to FALSE probe return");
3364 gst_buffer_unref (buffer);
3365 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3366 "pushing, but it was not linked");
3367 GST_OBJECT_UNLOCK (pad);
3368 return GST_FLOW_NOT_LINKED;
3372 gst_buffer_unref (buffer);
3373 gst_object_unref (peer);
3374 GST_CAT_DEBUG_OBJECT (GST_CAT_SCHEDULING, pad,
3375 "element pushed buffer then refused to accept the caps");
3376 return GST_FLOW_NOT_NEGOTIATED;
3381 * gst_pad_check_pull_range:
3382 * @pad: a sink #GstPad.
3384 * Checks if a gst_pad_pull_range() can be performed on the peer
3385 * source pad. This function is used by plugins that want to check
3386 * if they can use random access on the peer source pad.
3388 * The peer sourcepad can implement a custom #GstPadCheckGetRangeFunction
3389 * if it needs to perform some logic to determine if pull_range is
3392 * Returns: a gboolean with the result.
3397 gst_pad_check_pull_range (GstPad * pad)
3401 GstPadCheckGetRangeFunction checkgetrangefunc;
3403 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
3405 GST_OBJECT_LOCK (pad);
3406 if (GST_PAD_DIRECTION (pad) != GST_PAD_SINK)
3407 goto wrong_direction;
3409 if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
3412 gst_object_ref (peer);
3413 GST_OBJECT_UNLOCK (pad);
3415 /* see note in above function */
3416 if (G_LIKELY ((checkgetrangefunc = peer->checkgetrangefunc) == NULL)) {
3417 /* FIXME, kindoff ghetto */
3418 ret = GST_PAD_GETRANGEFUNC (peer) != NULL;
3420 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3421 "calling checkgetrangefunc %s of peer pad %s:%s",
3422 GST_DEBUG_FUNCPTR_NAME (checkgetrangefunc), GST_DEBUG_PAD_NAME (peer));
3424 ret = checkgetrangefunc (peer);
3427 gst_object_unref (peer);
3431 /* ERROR recovery here */
3434 GST_OBJECT_UNLOCK (pad);
3439 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3440 "checking pull range, but it was not linked");
3441 GST_OBJECT_UNLOCK (pad);
3447 * gst_pad_get_range:
3448 * @pad: a src #GstPad.
3449 * @offset: The start offset of the buffer
3450 * @size: The length of the buffer
3451 * @buffer: a pointer to hold the #GstBuffer.
3453 * Calls the getrange function of @pad.
3455 * Returns: a #GstFlowReturn from the pad.
3460 gst_pad_get_range (GstPad * pad, guint64 offset, guint size,
3461 GstBuffer ** buffer)
3464 GstPadGetRangeFunction getrangefunc;
3465 gboolean emit_signal;
3467 g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
3468 g_return_val_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SRC, GST_FLOW_ERROR);
3469 g_return_val_if_fail (buffer != NULL, GST_FLOW_ERROR);
3471 GST_PAD_STREAM_LOCK (pad);
3473 GST_OBJECT_LOCK (pad);
3474 if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad)))
3477 emit_signal = GST_PAD_DO_BUFFER_SIGNALS (pad) > 0;
3478 GST_OBJECT_UNLOCK (pad);
3480 if (G_UNLIKELY ((getrangefunc = GST_PAD_GETRANGEFUNC (pad)) == NULL))
3483 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3484 "calling getrangefunc %s of peer pad %s:%s, offset %"
3485 G_GUINT64_FORMAT ", size %u",
3486 GST_DEBUG_FUNCPTR_NAME (getrangefunc), GST_DEBUG_PAD_NAME (pad),
3489 ret = getrangefunc (pad, offset, size, buffer);
3491 /* can only fire the signal if we have a valid buffer */
3492 if (G_UNLIKELY (emit_signal) && (ret == GST_FLOW_OK)) {
3493 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (*buffer)))
3497 GST_PAD_STREAM_UNLOCK (pad);
3504 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3505 "pulling range, but pad was flushing");
3506 GST_OBJECT_UNLOCK (pad);
3507 GST_PAD_STREAM_UNLOCK (pad);
3508 return GST_FLOW_WRONG_STATE;
3512 GST_ELEMENT_ERROR (GST_PAD_PARENT (pad), CORE, PAD, (NULL),
3513 ("pullrange on pad %s:%s but it has no getrangefunction",
3514 GST_DEBUG_PAD_NAME (pad)));
3515 GST_PAD_STREAM_UNLOCK (pad);
3516 return GST_FLOW_ERROR;
3520 GST_DEBUG ("Dropping data after FALSE probe return");
3521 GST_PAD_STREAM_UNLOCK (pad);
3522 gst_buffer_unref (*buffer);
3524 return GST_FLOW_UNEXPECTED;
3530 * gst_pad_pull_range:
3531 * @pad: a sink #GstPad.
3532 * @offset: The start offset of the buffer
3533 * @size: The length of the buffer
3534 * @buffer: a pointer to hold the #GstBuffer.
3536 * Pulls a buffer from the peer pad. @pad must be a linked
3539 * Returns: a #GstFlowReturn from the peer pad.
3544 gst_pad_pull_range (GstPad * pad, guint64 offset, guint size,
3545 GstBuffer ** buffer)
3549 gboolean emit_signal;
3551 g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
3552 g_return_val_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SINK,
3554 g_return_val_if_fail (buffer != NULL, GST_FLOW_ERROR);
3556 GST_OBJECT_LOCK (pad);
3558 while (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad)))
3559 handle_pad_block (pad);
3561 if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
3564 /* signal emision for the pad, peer has chance to emit when
3565 * we call _get_range() */
3566 emit_signal = GST_PAD_DO_BUFFER_SIGNALS (pad) > 0;
3568 gst_object_ref (peer);
3569 GST_OBJECT_UNLOCK (pad);
3571 ret = gst_pad_get_range (peer, offset, size, buffer);
3573 gst_object_unref (peer);
3575 /* can only fire the signal if we have a valid buffer */
3576 if (G_UNLIKELY (emit_signal) && (ret == GST_FLOW_OK)) {
3577 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (*buffer)))
3582 /* ERROR recovery here */
3585 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3586 "pulling range, but it was not linked");
3587 GST_OBJECT_UNLOCK (pad);
3588 return GST_FLOW_NOT_LINKED;
3592 GST_DEBUG ("Dropping data after FALSE probe return");
3593 gst_buffer_unref (*buffer);
3595 return GST_FLOW_UNEXPECTED;
3600 * gst_pad_push_event:
3601 * @pad: a #GstPad to push the event to.
3602 * @event: the #GstEvent to send to the pad.
3604 * Sends the event to the peer of the given pad. This function is
3605 * mainly used by elements to send events to their peer
3608 * This function takes owership of the provided event so you should
3609 * gst_event_ref() it if you want to reuse the event after this call.
3611 * Returns: TRUE if the event was handled.
3616 gst_pad_push_event (GstPad * pad, GstEvent * event)
3621 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
3622 g_return_val_if_fail (event != NULL, FALSE);
3623 g_return_val_if_fail (GST_IS_EVENT (event), FALSE);
3625 GST_OBJECT_LOCK (pad);
3626 switch (GST_EVENT_TYPE (event)) {
3627 case GST_EVENT_FLUSH_START:
3628 GST_PAD_SET_FLUSHING (pad);
3630 case GST_EVENT_FLUSH_STOP:
3631 GST_PAD_UNSET_FLUSHING (pad);
3637 if (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad))) {
3638 if (GST_EVENT_TYPE (event) == GST_EVENT_FLUSH_START) {
3639 GST_PAD_BLOCK_SIGNAL (pad);
3643 if (G_UNLIKELY (GST_PAD_DO_EVENT_SIGNALS (pad) > 0)) {
3644 GST_OBJECT_UNLOCK (pad);
3646 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (event)))
3649 GST_OBJECT_LOCK (pad);
3651 peerpad = GST_PAD_PEER (pad);
3652 if (peerpad == NULL)
3655 GST_LOG_OBJECT (peerpad, "sending event on peerpad");
3656 gst_object_ref (peerpad);
3657 GST_OBJECT_UNLOCK (pad);
3659 result = gst_pad_send_event (peerpad, event);
3661 gst_object_unref (peerpad);
3662 GST_LOG_OBJECT (peerpad, "sent event on peerpad");
3666 /* ERROR handling */
3669 GST_DEBUG_OBJECT (pad, "Dropping event after FALSE probe return");
3670 gst_event_unref (event);
3675 gst_event_unref (event);
3676 GST_OBJECT_UNLOCK (pad);
3682 * gst_pad_send_event:
3683 * @pad: a #GstPad to send the event to.
3684 * @event: the #GstEvent to send to the pad.
3686 * Sends the event to the pad. This function can be used
3687 * by applications to send events in the pipeline.
3689 * If @pad is a source pad, @event should be an upstream event. If @pad is a
3690 * sink pad, @event should be a downstream event. For example, you would not
3691 * send a #GST_EVENT_EOS on a src pad; EOS events only propagate downstream.
3692 * Furthermore, some downstream events have to be serialized with data flow,
3693 * like EOS, while some can travel out-of-band, like #GST_EVENT_FLUSH_START. If
3694 * the event needs to be serialized with data flow, this function will take the
3695 * pad's stream lock while calling its event function.
3697 * To find out whether an event type is upstream, downstream, or downstream and
3698 * serialized, see #GstEventTypeFlags, gst_event_type_get_flags(),
3699 * #GST_EVENT_IS_UPSTREAM, #GST_EVENT_IS_DOWNSTREAM, and
3700 * #GST_EVENT_IS_SERIALIZED. Note that in practice that an application or plugin
3701 * doesn't need to bother itself with this information; the core handles all
3702 * necessary locks and checks.
3704 * This function takes owership of the provided event so you should
3705 * gst_event_ref() it if you want to reuse the event after this call.
3707 * Returns: TRUE if the event was handled.
3710 gst_pad_send_event (GstPad * pad, GstEvent * event)
3712 gboolean result = FALSE;
3713 GstPadEventFunction eventfunc;
3714 gboolean serialized, need_unlock = FALSE;
3716 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
3717 g_return_val_if_fail (event != NULL, FALSE);
3719 GST_OBJECT_LOCK (pad);
3720 if (GST_PAD_IS_SINK (pad)) {
3721 if (G_UNLIKELY (!GST_EVENT_IS_DOWNSTREAM (event)))
3722 goto wrong_direction;
3723 serialized = GST_EVENT_IS_SERIALIZED (event);
3724 } else if (GST_PAD_IS_SRC (pad)) {
3725 if (G_UNLIKELY (!GST_EVENT_IS_UPSTREAM (event)))
3726 goto wrong_direction;
3727 /* events on srcpad never are serialized */
3730 goto unknown_direction;
3732 if (G_UNLIKELY (GST_EVENT_SRC (event) == NULL)) {
3733 GST_LOG_OBJECT (pad, "event had no source, setting pad as event source");
3734 GST_EVENT_SRC (event) = gst_object_ref (pad);
3738 if (G_UNLIKELY (GST_PAD_DO_EVENT_SIGNALS (pad) > 0)) {
3739 GST_OBJECT_UNLOCK (pad);
3741 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT_CAST (event)))
3744 GST_OBJECT_LOCK (pad);
3747 switch (GST_EVENT_TYPE (event)) {
3748 case GST_EVENT_FLUSH_START:
3749 GST_CAT_DEBUG (GST_CAT_EVENT,
3750 "have event type %d (FLUSH_START) on pad %s:%s",
3751 GST_EVENT_TYPE (event), GST_DEBUG_PAD_NAME (pad));
3753 /* can't even accept a flush begin event when flushing */
3754 if (GST_PAD_IS_FLUSHING (pad))
3756 GST_PAD_SET_FLUSHING (pad);
3757 GST_CAT_DEBUG (GST_CAT_EVENT, "set flush flag");
3759 case GST_EVENT_FLUSH_STOP:
3760 GST_PAD_UNSET_FLUSHING (pad);
3761 GST_CAT_DEBUG (GST_CAT_EVENT, "cleared flush flag");
3762 GST_OBJECT_UNLOCK (pad);
3763 /* grab stream lock */
3764 GST_PAD_STREAM_LOCK (pad);
3766 GST_OBJECT_LOCK (pad);
3769 GST_CAT_DEBUG (GST_CAT_EVENT, "have event type %s on pad %s:%s",
3770 GST_EVENT_TYPE_NAME (event), GST_DEBUG_PAD_NAME (pad));
3772 /* make this a little faster, no point in grabbing the lock
3773 * if the pad is allready flushing. */
3774 if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad)))
3778 /* lock order: STREAM_LOCK, LOCK */
3779 GST_OBJECT_UNLOCK (pad);
3780 GST_PAD_STREAM_LOCK (pad);
3782 GST_OBJECT_LOCK (pad);
3783 if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad)))
3788 if (G_UNLIKELY ((eventfunc = GST_PAD_EVENTFUNC (pad)) == NULL))
3791 GST_OBJECT_UNLOCK (pad);
3793 result = eventfunc (pad, event);
3796 GST_PAD_STREAM_UNLOCK (pad);
3800 /* ERROR handling */
3803 g_warning ("pad %s:%s sending %s event in wrong direction",
3804 GST_DEBUG_PAD_NAME (pad), GST_EVENT_TYPE_NAME (event));
3805 GST_OBJECT_UNLOCK (pad);
3806 gst_event_unref (event);
3811 g_warning ("pad %s:%s has invalid direction", GST_DEBUG_PAD_NAME (pad));
3812 GST_OBJECT_UNLOCK (pad);
3813 gst_event_unref (event);
3818 g_warning ("pad %s:%s has no event handler, file a bug.",
3819 GST_DEBUG_PAD_NAME (pad));
3820 GST_OBJECT_UNLOCK (pad);
3821 gst_event_unref (event);
3826 GST_OBJECT_UNLOCK (pad);
3828 GST_PAD_STREAM_UNLOCK (pad);
3829 GST_CAT_INFO (GST_CAT_EVENT, "Received event on flushing pad. Discarding");
3830 gst_event_unref (event);
3835 GST_DEBUG ("Dropping event after FALSE probe return");
3836 gst_event_unref (event);
3842 * gst_pad_set_element_private:
3843 * @pad: the #GstPad to set the private data of.
3844 * @priv: The private data to attach to the pad.
3846 * Set the given private data gpointer on the pad.
3847 * This function can only be used by the element that owns the pad.
3848 * No locking is performed in this function.
3851 gst_pad_set_element_private (GstPad * pad, gpointer priv)
3853 pad->element_private = priv;
3857 * gst_pad_get_element_private:
3858 * @pad: the #GstPad to get the private data of.
3860 * Gets the private data of a pad.
3861 * No locking is performed in this function.
3863 * Returns: a #gpointer to the private data.
3866 gst_pad_get_element_private (GstPad * pad)
3868 return pad->element_private;
3872 * gst_pad_start_task:
3873 * @pad: the #GstPad to start the task of
3874 * @func: the task function to call
3875 * @data: data passed to the task function
3877 * Starts a task that repeadedly calls @func with @data. This function
3878 * is nostly used in the pad activation function to start the
3879 * dataflow. This function will automatically acquire the STREAM_LOCK of
3880 * the pad before calling @func.
3882 * Returns: a TRUE if the task could be started.
3885 gst_pad_start_task (GstPad * pad, GstTaskFunction func, gpointer data)
3889 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
3890 g_return_val_if_fail (func != NULL, FALSE);
3892 GST_OBJECT_LOCK (pad);
3893 task = GST_PAD_TASK (pad);
3895 task = gst_task_create (func, data);
3896 gst_task_set_lock (task, GST_PAD_GET_STREAM_LOCK (pad));
3897 GST_PAD_TASK (pad) = task;
3899 gst_task_start (task);
3900 GST_OBJECT_UNLOCK (pad);
3906 * gst_pad_pause_task:
3907 * @pad: the #GstPad to pause the task of
3909 * Pause the task of @pad. This function will also make sure that the
3910 * function executed by the task will effectively stop.
3912 * Returns: a TRUE if the task could be paused or FALSE when the pad
3916 gst_pad_pause_task (GstPad * pad)
3920 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
3922 GST_OBJECT_LOCK (pad);
3923 task = GST_PAD_TASK (pad);
3926 gst_task_pause (task);
3927 GST_OBJECT_UNLOCK (pad);
3929 GST_PAD_STREAM_LOCK (pad);
3930 GST_PAD_STREAM_UNLOCK (pad);
3936 GST_DEBUG_OBJECT (pad, "pad has no task");
3937 GST_OBJECT_UNLOCK (pad);
3943 * gst_pad_stop_task:
3944 * @pad: the #GstPad to stop the task of
3946 * Stop the task of @pad. This function will also make sure that the
3947 * function executed by the task will effectively stop if not called
3948 * from the GstTaskFunction.
3950 * This function will deadlock if called from the GstTaskFunction of
3951 * the task. Use gst_task_pause() instead.
3953 * Regardless of whether the pad has a task, the stream lock is acquired and
3954 * released so as to ensure that streaming through this pad has finished.
3956 * Returns: a TRUE if the task could be stopped or FALSE on error.
3959 gst_pad_stop_task (GstPad * pad)
3963 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
3965 GST_OBJECT_LOCK (pad);
3966 task = GST_PAD_TASK (pad);
3969 GST_PAD_TASK (pad) = NULL;
3970 gst_task_stop (task);
3971 GST_OBJECT_UNLOCK (pad);
3973 GST_PAD_STREAM_LOCK (pad);
3974 GST_PAD_STREAM_UNLOCK (pad);
3976 gst_task_join (task);
3978 gst_object_unref (task);
3984 GST_OBJECT_UNLOCK (pad);
3986 GST_PAD_STREAM_LOCK (pad);
3987 GST_PAD_STREAM_UNLOCK (pad);