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() and
58 * gst_pad_push_event().
60 * Last reviewed on 2006-07-06 (0.10.9)
63 #include "gst_private.h"
66 #include "gstpadtemplate.h"
67 #include "gstenumtypes.h"
68 #include "gstmarshal.h"
73 #include "glib-compat-private.h"
75 GST_DEBUG_CATEGORY_STATIC (debug_dataflow);
76 #define GST_CAT_DEFAULT GST_CAT_PADS
78 /* Pad signals and args */
98 static void gst_pad_class_init (GstPadClass * klass);
99 static void gst_pad_init (GstPad * pad);
100 static void gst_pad_dispose (GObject * object);
101 static void gst_pad_finalize (GObject * object);
102 static void gst_pad_set_property (GObject * object, guint prop_id,
103 const GValue * value, GParamSpec * pspec);
104 static void gst_pad_get_property (GObject * object, guint prop_id,
105 GValue * value, GParamSpec * pspec);
107 static GstFlowReturn handle_pad_block (GstPad * pad);
108 static GstCaps *gst_pad_get_caps_unlocked (GstPad * pad);
109 static void gst_pad_set_pad_template (GstPad * pad, GstPadTemplate * templ);
110 static gboolean gst_pad_activate_default (GstPad * pad);
111 static gboolean gst_pad_acceptcaps_default (GstPad * pad, GstCaps * caps);
113 #ifndef GST_DISABLE_LOADSAVE
114 static xmlNodePtr gst_pad_save_thyself (GstObject * object, xmlNodePtr parent);
117 static GstObjectClass *parent_class = NULL;
118 static guint gst_pad_signals[LAST_SIGNAL] = { 0 };
120 /* quarks for probe signals */
121 static GQuark buffer_quark;
122 static GQuark event_quark;
131 static GstFlowQuarks flow_quarks[] = {
132 {GST_FLOW_CUSTOM_SUCCESS, "custom-success", 0},
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},
141 {GST_FLOW_CUSTOM_ERROR, "custom-error", 0},
148 * @ret: a #GstFlowReturn to get the name of.
150 * Gets a string representing the given flow return.
152 * Returns: a static string with the name of the flow return.
154 G_CONST_RETURN gchar *
155 gst_flow_get_name (GstFlowReturn ret)
159 ret = CLAMP (ret, GST_FLOW_CUSTOM_ERROR, GST_FLOW_CUSTOM_SUCCESS);
161 for (i = 0; flow_quarks[i].name; i++) {
162 if (ret == flow_quarks[i].ret)
163 return flow_quarks[i].name;
170 * @ret: a #GstFlowReturn to get the quark of.
172 * Get the unique quark for the given GstFlowReturn.
174 * Returns: the quark associated with the flow return or 0 if an
175 * invalid return was specified.
178 gst_flow_to_quark (GstFlowReturn ret)
182 ret = CLAMP (ret, GST_FLOW_CUSTOM_ERROR, GST_FLOW_CUSTOM_SUCCESS);
184 for (i = 0; flow_quarks[i].name; i++) {
185 if (ret == flow_quarks[i].ret)
186 return flow_quarks[i].quark;
192 gst_pad_get_type (void)
194 static GType gst_pad_type = 0;
196 if (G_UNLIKELY (gst_pad_type == 0)) {
197 static const GTypeInfo pad_info = {
198 sizeof (GstPadClass), NULL, NULL,
199 (GClassInitFunc) gst_pad_class_init, NULL, NULL,
202 (GInstanceInitFunc) gst_pad_init, NULL
206 gst_pad_type = g_type_register_static (GST_TYPE_OBJECT, "GstPad",
209 buffer_quark = g_quark_from_static_string ("buffer");
210 event_quark = g_quark_from_static_string ("event");
212 for (i = 0; flow_quarks[i].name; i++) {
213 flow_quarks[i].quark = g_quark_from_static_string (flow_quarks[i].name);
216 GST_DEBUG_CATEGORY_INIT (debug_dataflow, "GST_DATAFLOW",
217 GST_DEBUG_BOLD | GST_DEBUG_FG_GREEN, "dataflow inside pads");
223 _gst_do_pass_data_accumulator (GSignalInvocationHint * ihint,
224 GValue * return_accu, const GValue * handler_return, gpointer dummy)
226 gboolean ret = g_value_get_boolean (handler_return);
228 GST_DEBUG ("accumulated %d", ret);
229 g_value_set_boolean (return_accu, ret);
235 default_have_data (GstPad * pad, GstMiniObject * o)
241 gst_pad_class_init (GstPadClass * klass)
243 GObjectClass *gobject_class;
244 GstObjectClass *gstobject_class;
246 gobject_class = G_OBJECT_CLASS (klass);
247 gstobject_class = GST_OBJECT_CLASS (klass);
249 parent_class = g_type_class_peek_parent (klass);
251 gobject_class->dispose = GST_DEBUG_FUNCPTR (gst_pad_dispose);
252 gobject_class->finalize = GST_DEBUG_FUNCPTR (gst_pad_finalize);
253 gobject_class->set_property = GST_DEBUG_FUNCPTR (gst_pad_set_property);
254 gobject_class->get_property = GST_DEBUG_FUNCPTR (gst_pad_get_property);
258 * @pad: the pad that emitted the signal
259 * @peer: the peer pad that has been connected
261 * Signals that a pad has been linked to the peer pad.
263 gst_pad_signals[PAD_LINKED] =
264 g_signal_new ("linked", G_TYPE_FROM_CLASS (klass), G_SIGNAL_RUN_LAST,
265 G_STRUCT_OFFSET (GstPadClass, linked), NULL, NULL,
266 gst_marshal_VOID__OBJECT, G_TYPE_NONE, 1, GST_TYPE_PAD);
269 * @pad: the pad that emitted the signal
270 * @peer: the peer pad that has been disconnected
272 * Signals that a pad has been unlinked from the peer pad.
274 gst_pad_signals[PAD_UNLINKED] =
275 g_signal_new ("unlinked", G_TYPE_FROM_CLASS (klass), G_SIGNAL_RUN_LAST,
276 G_STRUCT_OFFSET (GstPadClass, unlinked), NULL, NULL,
277 gst_marshal_VOID__OBJECT, G_TYPE_NONE, 1, GST_TYPE_PAD);
279 * GstPad::request-link:
280 * @pad: the pad that emitted the signal
281 * @peer: the peer pad for which a connection is requested
283 * Signals that a pad connection has been requested.
285 gst_pad_signals[PAD_REQUEST_LINK] =
286 g_signal_new ("request-link", G_TYPE_FROM_CLASS (klass),
287 G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GstPadClass, request_link), NULL,
288 NULL, gst_marshal_VOID__OBJECT, G_TYPE_NONE, 0);
292 * @pad: the pad that emitted the signal
293 * @mini_obj: new data
295 * Signals that new data is available on the pad. This signal is used
296 * internally for implementing pad probes.
297 * See gst_pad_add_*_probe functions.
299 * Returns: %TRUE to keep the data, %FALSE to drop it
301 gst_pad_signals[PAD_HAVE_DATA] =
302 g_signal_new ("have-data", G_TYPE_FROM_CLASS (klass),
303 G_SIGNAL_RUN_LAST | G_SIGNAL_DETAILED,
304 G_STRUCT_OFFSET (GstPadClass, have_data),
305 _gst_do_pass_data_accumulator,
306 NULL, gst_marshal_BOOLEAN__POINTER, G_TYPE_BOOLEAN, 1,
307 GST_TYPE_MINI_OBJECT);
309 g_object_class_install_property (gobject_class, PAD_PROP_CAPS,
310 g_param_spec_boxed ("caps", "Caps", "The capabilities of the pad",
311 GST_TYPE_CAPS, G_PARAM_READABLE));
312 g_object_class_install_property (gobject_class, PAD_PROP_DIRECTION,
313 g_param_spec_enum ("direction", "Direction", "The direction of the pad",
314 GST_TYPE_PAD_DIRECTION, GST_PAD_UNKNOWN,
315 G_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY));
316 g_object_class_install_property (gobject_class, PAD_PROP_TEMPLATE,
317 g_param_spec_object ("template", "Template",
318 "The GstPadTemplate of this pad", GST_TYPE_PAD_TEMPLATE,
321 #ifndef GST_DISABLE_LOADSAVE
322 gstobject_class->save_thyself = GST_DEBUG_FUNCPTR (gst_pad_save_thyself);
324 gstobject_class->path_string_separator = ".";
326 klass->have_data = default_have_data;
330 gst_pad_init (GstPad * pad)
332 GST_PAD_DIRECTION (pad) = GST_PAD_UNKNOWN;
333 GST_PAD_PEER (pad) = NULL;
335 GST_PAD_CHAINFUNC (pad) = NULL;
337 GST_PAD_LINKFUNC (pad) = NULL;
339 GST_PAD_CAPS (pad) = NULL;
340 GST_PAD_GETCAPSFUNC (pad) = NULL;
342 GST_PAD_ACTIVATEFUNC (pad) = GST_DEBUG_FUNCPTR (gst_pad_activate_default);
343 GST_PAD_EVENTFUNC (pad) = GST_DEBUG_FUNCPTR (gst_pad_event_default);
344 GST_PAD_QUERYTYPEFUNC (pad) =
345 GST_DEBUG_FUNCPTR (gst_pad_get_query_types_default);
346 GST_PAD_QUERYFUNC (pad) = GST_DEBUG_FUNCPTR (gst_pad_query_default);
347 GST_PAD_INTLINKFUNC (pad) =
348 GST_DEBUG_FUNCPTR (gst_pad_get_internal_links_default);
349 GST_PAD_ACCEPTCAPSFUNC (pad) = GST_DEBUG_FUNCPTR (gst_pad_acceptcaps_default);
351 pad->do_buffer_signals = 0;
352 pad->do_event_signals = 0;
354 /* FIXME, should be set flushing initially, see #339326 */
355 GST_PAD_UNSET_FLUSHING (pad);
357 pad->preroll_lock = g_mutex_new ();
358 pad->preroll_cond = g_cond_new ();
360 pad->stream_rec_lock = g_new (GStaticRecMutex, 1);
361 g_static_rec_mutex_init (pad->stream_rec_lock);
363 pad->block_cond = g_cond_new ();
367 gst_pad_dispose (GObject * object)
369 GstPad *pad = GST_PAD (object);
371 GST_CAT_DEBUG (GST_CAT_REFCOUNTING, "dispose %s:%s",
372 GST_DEBUG_PAD_NAME (pad));
374 /* we don't hold a ref to the peer so we can just set the
376 GST_PAD_PEER (pad) = NULL;
379 gst_caps_replace (&GST_PAD_CAPS (pad), NULL);
381 gst_pad_set_pad_template (pad, NULL);
383 G_OBJECT_CLASS (parent_class)->dispose (object);
387 gst_pad_finalize (GObject * object)
389 GstPad *pad = GST_PAD (object);
392 /* in case the task is still around, clean it up */
393 if ((task = GST_PAD_TASK (pad))) {
394 gst_task_join (task);
395 GST_PAD_TASK (pad) = NULL;
396 gst_object_unref (task);
399 if (pad->stream_rec_lock) {
400 g_static_rec_mutex_free (pad->stream_rec_lock);
401 g_free (pad->stream_rec_lock);
402 pad->stream_rec_lock = NULL;
404 if (pad->preroll_lock) {
405 g_mutex_free (pad->preroll_lock);
406 g_cond_free (pad->preroll_cond);
407 pad->preroll_lock = NULL;
408 pad->preroll_cond = NULL;
410 if (pad->block_cond) {
411 g_cond_free (pad->block_cond);
412 pad->block_cond = NULL;
415 G_OBJECT_CLASS (parent_class)->finalize (object);
419 gst_pad_set_property (GObject * object, guint prop_id,
420 const GValue * value, GParamSpec * pspec)
422 g_return_if_fail (GST_IS_PAD (object));
425 case PAD_PROP_DIRECTION:
426 GST_PAD_DIRECTION (object) = g_value_get_enum (value);
428 case PAD_PROP_TEMPLATE:
429 gst_pad_set_pad_template (GST_PAD_CAST (object),
430 (GstPadTemplate *) g_value_get_object (value));
433 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
439 gst_pad_get_property (GObject * object, guint prop_id,
440 GValue * value, GParamSpec * pspec)
442 g_return_if_fail (GST_IS_PAD (object));
446 g_value_set_boxed (value, GST_PAD_CAPS (object));
448 case PAD_PROP_DIRECTION:
449 g_value_set_enum (value, GST_PAD_DIRECTION (object));
451 case PAD_PROP_TEMPLATE:
452 g_value_set_object (value, GST_PAD_PAD_TEMPLATE (object));
455 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
462 * @name: the name of the new pad.
463 * @direction: the #GstPadDirection of the pad.
465 * Creates a new pad with the given name in the given direction.
466 * If name is NULL, a guaranteed unique name (across all pads)
468 * This function makes a copy of the name so you can safely free the name.
470 * Returns: a new #GstPad, or NULL in case of an error.
475 gst_pad_new (const gchar * name, GstPadDirection direction)
477 return g_object_new (GST_TYPE_PAD,
478 "name", name, "direction", direction, NULL);
482 * gst_pad_new_from_template:
483 * @templ: the pad template to use
484 * @name: the name of the element
486 * Creates a new pad with the given name from the given template.
487 * If name is NULL, a guaranteed unique name (across all pads)
489 * This function makes a copy of the name so you can safely free the name.
491 * Returns: a new #GstPad, or NULL in case of an error.
494 gst_pad_new_from_template (GstPadTemplate * templ, const gchar * name)
496 g_return_val_if_fail (GST_IS_PAD_TEMPLATE (templ), NULL);
498 return g_object_new (GST_TYPE_PAD,
499 "name", name, "direction", templ->direction, "template", templ, NULL);
503 * gst_pad_new_from_static_template:
504 * @templ: the #GstStaticPadTemplate to use
505 * @name: the name of the element
507 * Creates a new pad with the given name from the given static template.
508 * If name is NULL, a guaranteed unique name (across all pads)
510 * This function makes a copy of the name so you can safely free the name.
512 * Returns: a new #GstPad, or NULL in case of an error.
515 gst_pad_new_from_static_template (GstStaticPadTemplate * templ,
519 GstPadTemplate *template;
521 template = gst_static_pad_template_get (templ);
522 pad = gst_pad_new_from_template (template, name);
523 gst_object_unref (template);
528 * gst_pad_get_direction:
529 * @pad: a #GstPad to get the direction of.
531 * Gets the direction of the pad. The direction of the pad is
532 * decided at construction time so this function does not take
535 * Returns: the #GstPadDirection of the pad.
540 gst_pad_get_direction (GstPad * pad)
542 GstPadDirection result;
544 /* PAD_UNKNOWN is a little silly but we need some sort of
545 * error return value */
546 g_return_val_if_fail (GST_IS_PAD (pad), GST_PAD_UNKNOWN);
548 GST_OBJECT_LOCK (pad);
549 result = GST_PAD_DIRECTION (pad);
550 GST_OBJECT_UNLOCK (pad);
556 gst_pad_activate_default (GstPad * pad)
558 return gst_pad_activate_push (pad, TRUE);
562 pre_activate (GstPad * pad, GstActivateMode new_mode)
565 case GST_ACTIVATE_PUSH:
566 case GST_ACTIVATE_PULL:
567 GST_OBJECT_LOCK (pad);
568 GST_DEBUG_OBJECT (pad, "setting ACTIVATE_MODE %d, unset flushing",
570 GST_PAD_UNSET_FLUSHING (pad);
571 GST_PAD_ACTIVATE_MODE (pad) = new_mode;
572 GST_OBJECT_UNLOCK (pad);
574 case GST_ACTIVATE_NONE:
575 GST_OBJECT_LOCK (pad);
576 GST_DEBUG_OBJECT (pad, "setting ACTIVATE_MODE NONE, set flushing",
578 GST_PAD_SET_FLUSHING (pad);
579 /* unlock blocked pads so element can resume and stop */
580 GST_PAD_BLOCK_SIGNAL (pad);
581 GST_OBJECT_UNLOCK (pad);
587 post_activate (GstPad * pad, GstActivateMode new_mode)
590 case GST_ACTIVATE_PUSH:
591 case GST_ACTIVATE_PULL:
594 case GST_ACTIVATE_NONE:
595 /* ensures that streaming stops */
596 GST_PAD_STREAM_LOCK (pad);
597 /* while we're at it set activation mode */
598 GST_OBJECT_LOCK (pad);
599 GST_DEBUG_OBJECT (pad, "setting ACTIVATE_MODE %d", new_mode);
600 GST_PAD_ACTIVATE_MODE (pad) = new_mode;
601 GST_OBJECT_UNLOCK (pad);
602 GST_PAD_STREAM_UNLOCK (pad);
608 * gst_pad_set_active:
609 * @pad: the #GstPad to activate or deactivate.
610 * @active: whether or not the pad should be active.
612 * Activates or deactivates the given pad.
613 * Normally called from within core state change functions.
615 * If @active, makes sure the pad is active. If it is already active, either in
616 * push or pull mode, just return. Otherwise dispatches to the pad's activate
617 * function to perform the actual activation.
619 * If not @active, checks the pad's current mode and calls
620 * gst_pad_activate_push() or gst_pad_activate_pull(), as appropriate, with a
623 * Returns: #TRUE if the operation was successful.
628 gst_pad_set_active (GstPad * pad, gboolean active)
631 gboolean ret = FALSE;
633 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
635 GST_OBJECT_LOCK (pad);
636 old = GST_PAD_ACTIVATE_MODE (pad);
637 GST_OBJECT_UNLOCK (pad);
641 case GST_ACTIVATE_PUSH:
642 case GST_ACTIVATE_PULL:
645 case GST_ACTIVATE_NONE:
646 ret = (GST_PAD_ACTIVATEFUNC (pad)) (pad);
651 case GST_ACTIVATE_PUSH:
652 ret = gst_pad_activate_push (pad, FALSE);
654 case GST_ACTIVATE_PULL:
655 ret = gst_pad_activate_pull (pad, FALSE);
657 case GST_ACTIVATE_NONE:
663 if (!active && !ret) {
664 GST_OBJECT_LOCK (pad);
665 g_critical ("Failed to deactivate pad %s:%s, very bad",
666 GST_DEBUG_PAD_NAME (pad));
667 GST_OBJECT_UNLOCK (pad);
674 * gst_pad_activate_pull:
675 * @pad: the #GstPad to activate or deactivate.
676 * @active: whether or not the pad should be active.
678 * Activates or deactivates the given pad in pull mode via dispatching to the
679 * pad's activatepullfunc. For use from within pad activation functions only.
680 * When called on sink pads, will first proxy the call to the peer pad, which is
681 * expected to activate its internally linked pads from within its activate_pull
684 * If you don't know what this is, you probably don't want to call it.
686 * Returns: TRUE if the operation was successful.
691 gst_pad_activate_pull (GstPad * pad, gboolean active)
693 GstActivateMode old, new;
696 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
698 GST_OBJECT_LOCK (pad);
699 old = GST_PAD_ACTIVATE_MODE (pad);
700 GST_OBJECT_UNLOCK (pad);
704 case GST_ACTIVATE_PULL:
706 case GST_ACTIVATE_PUSH:
707 /* pad was activate in the wrong direction, deactivate it
708 * and reactivate it in pull mode */
709 if (G_UNLIKELY (!gst_pad_activate_push (pad, FALSE)))
710 goto deactivate_failed;
711 /* fallthrough, pad is deactivated now. */
712 case GST_ACTIVATE_NONE:
717 case GST_ACTIVATE_NONE:
719 case GST_ACTIVATE_PUSH:
720 /* pad was activated in the other direction, deactivate it
721 * in push mode, this should not happen... */
722 if (G_UNLIKELY (!gst_pad_activate_push (pad, FALSE)))
723 goto deactivate_failed;
724 /* everything is fine now */
726 case GST_ACTIVATE_PULL:
731 if (gst_pad_get_direction (pad) == GST_PAD_SINK) {
732 if ((peer = gst_pad_get_peer (pad))) {
733 if (G_UNLIKELY (!gst_pad_activate_pull (peer, active)))
735 gst_object_unref (peer);
738 if (G_UNLIKELY (GST_PAD_GETRANGEFUNC (pad) == NULL))
739 goto failure; /* Can't activate pull on a src without a
743 new = active ? GST_ACTIVATE_PULL : GST_ACTIVATE_NONE;
744 pre_activate (pad, new);
746 if (GST_PAD_ACTIVATEPULLFUNC (pad)) {
747 if (G_UNLIKELY (!GST_PAD_ACTIVATEPULLFUNC (pad) (pad, active)))
750 /* can happen for sinks of passthrough elements */
753 post_activate (pad, new);
755 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "%s in pull mode",
756 active ? "activated" : "deactivated");
762 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "already %s in pull mode",
763 active ? "activated" : "deactivated");
768 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
769 "failed to %s pad (%s:%s) in switch to pull from mode %d",
770 (active ? "activate" : "deactivate"), GST_DEBUG_PAD_NAME (pad), old);
775 GST_OBJECT_LOCK (peer);
776 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
777 "activate_pull on peer (%s:%s) failed", GST_DEBUG_PAD_NAME (peer));
778 GST_OBJECT_UNLOCK (peer);
779 gst_object_unref (peer);
784 GST_CAT_INFO_OBJECT (GST_CAT_PADS, pad, "failed to %s in pull mode",
785 active ? "activate" : "deactivate");
786 pre_activate (pad, GST_ACTIVATE_NONE);
787 post_activate (pad, GST_ACTIVATE_NONE);
793 * gst_pad_activate_push:
794 * @pad: the #GstPad to activate or deactivate.
795 * @active: whether the pad should be active or not.
797 * Activates or deactivates the given pad in push mode via dispatching to the
798 * pad's activatepushfunc. For use from within pad activation functions only.
800 * If you don't know what this is, you probably don't want to call it.
802 * Returns: %TRUE if the operation was successful.
807 gst_pad_activate_push (GstPad * pad, gboolean active)
809 GstActivateMode old, new;
811 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
812 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "trying to set %s in push mode",
813 active ? "activated" : "deactivated");
815 GST_OBJECT_LOCK (pad);
816 old = GST_PAD_ACTIVATE_MODE (pad);
817 GST_OBJECT_UNLOCK (pad);
821 case GST_ACTIVATE_PUSH:
823 case GST_ACTIVATE_PULL:
824 /* pad was activate in the wrong direction, deactivate it
825 * an reactivate it in push mode */
826 if (G_UNLIKELY (!gst_pad_activate_pull (pad, FALSE)))
827 goto deactivate_failed;
828 /* fallthrough, pad is deactivated now. */
829 case GST_ACTIVATE_NONE:
834 case GST_ACTIVATE_NONE:
836 case GST_ACTIVATE_PULL:
837 /* pad was activated in the other direction, deactivate it
838 * in pull mode, this should not happen... */
839 if (G_UNLIKELY (!gst_pad_activate_pull (pad, FALSE)))
840 goto deactivate_failed;
841 /* everything is fine now */
843 case GST_ACTIVATE_PUSH:
848 new = active ? GST_ACTIVATE_PUSH : GST_ACTIVATE_NONE;
849 pre_activate (pad, new);
851 if (GST_PAD_ACTIVATEPUSHFUNC (pad)) {
852 if (G_UNLIKELY (!GST_PAD_ACTIVATEPUSHFUNC (pad) (pad, active))) {
856 /* quite ok, element relies on state change func to prepare itself */
859 post_activate (pad, new);
861 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "%s in push mode",
862 active ? "activated" : "deactivated");
867 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "already %s in push mode",
868 active ? "activated" : "deactivated");
873 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
874 "failed to %s pad (%s:%s) in switch to push from mode %d",
875 (active ? "activate" : "deactivate"), GST_DEBUG_PAD_NAME (pad), old);
880 GST_CAT_INFO_OBJECT (GST_CAT_PADS, pad, "failed to %s in push mode",
881 active ? "activate" : "deactivate");
882 pre_activate (pad, GST_ACTIVATE_NONE);
883 post_activate (pad, GST_ACTIVATE_NONE);
890 * @pad: the #GstPad to query
892 * Query if a pad is active
894 * Returns: TRUE if the pad is active.
899 gst_pad_is_active (GstPad * pad)
901 gboolean result = FALSE;
903 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
905 GST_OBJECT_LOCK (pad);
906 result = GST_PAD_MODE_ACTIVATE (GST_PAD_ACTIVATE_MODE (pad));
907 GST_OBJECT_UNLOCK (pad);
913 * gst_pad_set_blocked_async:
914 * @pad: the #GstPad to block or unblock
915 * @blocked: boolean indicating whether the pad should be blocked or unblocked
916 * @callback: #GstPadBlockCallback that will be called when the
918 * @user_data: user data passed to the callback
920 * Blocks or unblocks the dataflow on a pad. The provided callback
921 * is called when the operation succeeds; this happens right before the next
922 * attempt at pushing a buffer on the pad.
924 * This can take a while as the pad can only become blocked when real dataflow
926 * When the pipeline is stalled, for example in PAUSED, this can
927 * take an indeterminate amount of time.
928 * You can pass NULL as the callback to make this call block. Be careful with
929 * this blocking call as it might not return for reasons stated above.
931 * Returns: TRUE if the pad could be blocked. This function can fail
932 * if wrong parameters were passed or the pad was already in the
938 gst_pad_set_blocked_async (GstPad * pad, gboolean blocked,
939 GstPadBlockCallback callback, gpointer user_data)
941 gboolean was_blocked = FALSE;
943 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
945 GST_OBJECT_LOCK (pad);
947 was_blocked = GST_PAD_IS_BLOCKED (pad);
949 if (G_UNLIKELY (was_blocked == blocked))
950 goto had_right_state;
953 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "blocking pad %s:%s",
954 GST_DEBUG_PAD_NAME (pad));
956 GST_OBJECT_FLAG_SET (pad, GST_PAD_BLOCKED);
957 pad->block_callback = callback;
958 pad->block_data = user_data;
960 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "waiting for block");
961 GST_PAD_BLOCK_WAIT (pad);
962 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "blocked");
965 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "unblocking pad %s:%s",
966 GST_DEBUG_PAD_NAME (pad));
968 GST_OBJECT_FLAG_UNSET (pad, GST_PAD_BLOCKED);
970 pad->block_callback = callback;
971 pad->block_data = user_data;
974 GST_PAD_BLOCK_SIGNAL (pad);
976 GST_PAD_BLOCK_SIGNAL (pad);
977 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "waiting for unblock");
978 GST_PAD_BLOCK_WAIT (pad);
979 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "unblocked");
982 GST_OBJECT_UNLOCK (pad);
988 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
989 "pad %s:%s was in right state (%d)", GST_DEBUG_PAD_NAME (pad),
991 GST_OBJECT_UNLOCK (pad);
998 * gst_pad_set_blocked:
999 * @pad: the #GstPad to block or unblock
1000 * @blocked: boolean indicating we should block or unblock
1002 * Blocks or unblocks the dataflow on a pad. This function is
1003 * a shortcut for gst_pad_set_blocked_async() with a NULL
1006 * Returns: TRUE if the pad could be blocked. This function can fail
1007 * wrong parameters were passed or the pad was already in the
1013 gst_pad_set_blocked (GstPad * pad, gboolean blocked)
1015 return gst_pad_set_blocked_async (pad, blocked, NULL, NULL);
1019 * gst_pad_is_blocked:
1020 * @pad: the #GstPad to query
1022 * Checks if the pad is blocked or not. This function returns the
1023 * last requested state of the pad. It is not certain that the pad
1024 * is actually blocked at this point.
1026 * Returns: TRUE if the pad is blocked.
1031 gst_pad_is_blocked (GstPad * pad)
1033 gboolean result = FALSE;
1035 g_return_val_if_fail (GST_IS_PAD (pad), result);
1037 GST_OBJECT_LOCK (pad);
1038 result = GST_OBJECT_FLAG_IS_SET (pad, GST_PAD_BLOCKED);
1039 GST_OBJECT_UNLOCK (pad);
1045 * gst_pad_set_activate_function:
1047 * @activate: the #GstPadActivateFunction to set.
1049 * Sets the given activate function for @pad. The activate function will
1050 * dispatch to gst_pad_activate_push() or gst_pad_activate_pull() to perform
1051 * the actual activation. Only makes sense to set on sink pads.
1053 * Call this function if your sink pad can start a pull-based task.
1056 gst_pad_set_activate_function (GstPad * pad, GstPadActivateFunction activate)
1058 g_return_if_fail (GST_IS_PAD (pad));
1060 GST_PAD_ACTIVATEFUNC (pad) = activate;
1061 GST_CAT_DEBUG (GST_CAT_PADS, "activatefunc for %s:%s set to %s",
1062 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (activate));
1066 * gst_pad_set_activatepull_function:
1068 * @activatepull: the #GstPadActivateModeFunction to set.
1070 * Sets the given activate_pull function for the pad. An activate_pull function
1071 * prepares the element and any upstream connections for pulling. See XXX
1072 * part-activation.txt for details.
1075 gst_pad_set_activatepull_function (GstPad * pad,
1076 GstPadActivateModeFunction activatepull)
1078 g_return_if_fail (GST_IS_PAD (pad));
1080 GST_PAD_ACTIVATEPULLFUNC (pad) = activatepull;
1081 GST_CAT_DEBUG (GST_CAT_PADS, "activatepullfunc for %s:%s set to %s",
1082 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (activatepull));
1086 * gst_pad_set_activatepush_function:
1088 * @activatepush: the #GstPadActivateModeFunction to set.
1090 * Sets the given activate_push function for the pad. An activate_push function
1091 * prepares the element for pushing. See XXX part-activation.txt for details.
1094 gst_pad_set_activatepush_function (GstPad * pad,
1095 GstPadActivateModeFunction activatepush)
1097 g_return_if_fail (GST_IS_PAD (pad));
1099 GST_PAD_ACTIVATEPUSHFUNC (pad) = activatepush;
1100 GST_CAT_DEBUG (GST_CAT_PADS, "activatepushfunc for %s:%s set to %s",
1101 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (activatepush));
1105 * gst_pad_set_chain_function:
1106 * @pad: a sink #GstPad.
1107 * @chain: the #GstPadChainFunction to set.
1109 * Sets the given chain function for the pad. The chain function is called to
1110 * process a #GstBuffer input buffer. see #GstPadChainFunction for more details.
1113 gst_pad_set_chain_function (GstPad * pad, GstPadChainFunction chain)
1115 g_return_if_fail (GST_IS_PAD (pad));
1116 g_return_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SINK);
1118 GST_PAD_CHAINFUNC (pad) = chain;
1119 GST_CAT_DEBUG (GST_CAT_PADS, "chainfunc for %s:%s set to %s",
1120 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (chain));
1124 * gst_pad_set_getrange_function:
1125 * @pad: a source #GstPad.
1126 * @get: the #GstPadGetRangeFunction to set.
1128 * Sets the given getrange function for the pad. The getrange function is called to
1129 * produce a new #GstBuffer to start the processing pipeline. see
1130 * #GstPadGetRangeFunction for a description of the getrange function.
1133 gst_pad_set_getrange_function (GstPad * pad, GstPadGetRangeFunction get)
1135 g_return_if_fail (GST_IS_PAD (pad));
1136 g_return_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SRC);
1138 GST_PAD_GETRANGEFUNC (pad) = get;
1140 GST_CAT_DEBUG (GST_CAT_PADS, "getrangefunc for %s:%s set to %s",
1141 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (get));
1145 * gst_pad_set_checkgetrange_function:
1146 * @pad: a source #GstPad.
1147 * @check: the #GstPadCheckGetRangeFunction to set.
1149 * Sets the given checkgetrange function for the pad. Implement this function on
1150 * a pad if you dynamically support getrange based scheduling on the pad.
1153 gst_pad_set_checkgetrange_function (GstPad * pad,
1154 GstPadCheckGetRangeFunction check)
1156 g_return_if_fail (GST_IS_PAD (pad));
1157 g_return_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SRC);
1159 GST_PAD_CHECKGETRANGEFUNC (pad) = check;
1161 GST_CAT_DEBUG (GST_CAT_PADS, "checkgetrangefunc for %s:%s set to %s",
1162 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (check));
1166 * gst_pad_set_event_function:
1167 * @pad: a source #GstPad.
1168 * @event: the #GstPadEventFunction to set.
1170 * Sets the given event handler for the pad.
1173 gst_pad_set_event_function (GstPad * pad, GstPadEventFunction event)
1175 g_return_if_fail (GST_IS_PAD (pad));
1177 GST_PAD_EVENTFUNC (pad) = event;
1179 GST_CAT_DEBUG (GST_CAT_PADS, "eventfunc for %s:%s set to %s",
1180 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (event));
1184 * gst_pad_set_query_function:
1185 * @pad: a #GstPad of either direction.
1186 * @query: the #GstPadQueryFunction to set.
1188 * Set the given query function for the pad.
1191 gst_pad_set_query_function (GstPad * pad, GstPadQueryFunction query)
1193 g_return_if_fail (GST_IS_PAD (pad));
1195 GST_PAD_QUERYFUNC (pad) = query;
1197 GST_CAT_DEBUG (GST_CAT_PADS, "queryfunc for %s:%s set to %s",
1198 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (query));
1202 * gst_pad_set_query_type_function:
1203 * @pad: a #GstPad of either direction.
1204 * @type_func: the #GstPadQueryTypeFunction to set.
1206 * Set the given query type function for the pad.
1209 gst_pad_set_query_type_function (GstPad * pad,
1210 GstPadQueryTypeFunction type_func)
1212 g_return_if_fail (GST_IS_PAD (pad));
1214 GST_PAD_QUERYTYPEFUNC (pad) = type_func;
1216 GST_CAT_DEBUG (GST_CAT_PADS, "querytypefunc for %s:%s set to %s",
1217 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (type_func));
1221 * gst_pad_get_query_types:
1224 * Get an array of supported queries that can be performed
1227 * Returns: a zero-terminated array of #GstQueryType.
1229 const GstQueryType *
1230 gst_pad_get_query_types (GstPad * pad)
1232 GstPadQueryTypeFunction func;
1234 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
1236 if (G_UNLIKELY ((func = GST_PAD_QUERYTYPEFUNC (pad)) == NULL))
1248 gst_pad_get_query_types_dispatcher (GstPad * pad, const GstQueryType ** data)
1250 *data = gst_pad_get_query_types (pad);
1256 * gst_pad_get_query_types_default:
1259 * Invoke the default dispatcher for the query types on
1262 * Returns: an zero-terminated array of #GstQueryType, or NULL if none of the
1263 * internally-linked pads has a query types function.
1265 const GstQueryType *
1266 gst_pad_get_query_types_default (GstPad * pad)
1268 GstQueryType *result = NULL;
1270 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
1272 gst_pad_dispatcher (pad, (GstPadDispatcherFunction)
1273 gst_pad_get_query_types_dispatcher, &result);
1279 * gst_pad_set_internal_link_function:
1280 * @pad: a #GstPad of either direction.
1281 * @intlink: the #GstPadIntLinkFunction to set.
1283 * Sets the given internal link function for the pad.
1286 gst_pad_set_internal_link_function (GstPad * pad, GstPadIntLinkFunction intlink)
1288 g_return_if_fail (GST_IS_PAD (pad));
1290 GST_PAD_INTLINKFUNC (pad) = intlink;
1291 GST_CAT_DEBUG (GST_CAT_PADS, "internal link for %s:%s set to %s",
1292 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (intlink));
1296 * gst_pad_set_link_function:
1298 * @link: the #GstPadLinkFunction to set.
1300 * Sets the given link function for the pad. It will be called when
1301 * the pad is linked with another pad.
1303 * The return value #GST_PAD_LINK_OK should be used when the connection can be
1306 * The return value #GST_PAD_LINK_REFUSED should be used when the connection
1307 * cannot be made for some reason.
1309 * If @link is installed on a source pad, it should call the #GstPadLinkFunction
1310 * of the peer sink pad, if present.
1313 gst_pad_set_link_function (GstPad * pad, GstPadLinkFunction link)
1315 g_return_if_fail (GST_IS_PAD (pad));
1317 GST_PAD_LINKFUNC (pad) = link;
1318 GST_CAT_DEBUG (GST_CAT_PADS, "linkfunc for %s:%s set to %s",
1319 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (link));
1323 * gst_pad_set_unlink_function:
1325 * @unlink: the #GstPadUnlinkFunction to set.
1327 * Sets the given unlink function for the pad. It will be called
1328 * when the pad is unlinked.
1331 gst_pad_set_unlink_function (GstPad * pad, GstPadUnlinkFunction unlink)
1333 g_return_if_fail (GST_IS_PAD (pad));
1335 GST_PAD_UNLINKFUNC (pad) = unlink;
1336 GST_CAT_DEBUG (GST_CAT_PADS, "unlinkfunc for %s:%s set to %s",
1337 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (unlink));
1341 * gst_pad_set_getcaps_function:
1343 * @getcaps: the #GstPadGetCapsFunction to set.
1345 * Sets the given getcaps function for the pad. @getcaps should return the
1346 * allowable caps for a pad in the context of the element's state, its link to
1347 * other elements, and the devices or files it has opened. These caps must be a
1348 * subset of the pad template caps. In the NULL state with no links, @getcaps
1349 * should ideally return the same caps as the pad template. In rare
1350 * circumstances, an object property can affect the caps returned by @getcaps,
1351 * but this is discouraged.
1353 * You do not need to call this function if @pad's allowed caps are always the
1354 * same as the pad template caps. This can only be true if the padtemplate
1355 * has fixed simple caps.
1357 * For most filters, the caps returned by @getcaps is directly affected by the
1358 * allowed caps on other pads. For demuxers and decoders, the caps returned by
1359 * the srcpad's getcaps function is directly related to the stream data. Again,
1360 * @getcaps should return the most specific caps it reasonably can, since this
1361 * helps with autoplugging.
1363 * Note that the return value from @getcaps is owned by the caller, so the caller
1364 * should unref the caps after usage.
1367 gst_pad_set_getcaps_function (GstPad * pad, GstPadGetCapsFunction getcaps)
1369 g_return_if_fail (GST_IS_PAD (pad));
1371 GST_PAD_GETCAPSFUNC (pad) = getcaps;
1372 GST_CAT_DEBUG (GST_CAT_PADS, "getcapsfunc for %s:%s set to %s",
1373 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (getcaps));
1377 * gst_pad_set_acceptcaps_function:
1379 * @acceptcaps: the #GstPadAcceptCapsFunction to set.
1381 * Sets the given acceptcaps function for the pad. The acceptcaps function
1382 * will be called to check if the pad can accept the given caps. Setting the
1383 * acceptcaps function to NULL restores the default behaviour of allowing
1384 * any caps that matches the caps from gst_pad_get_caps.
1387 gst_pad_set_acceptcaps_function (GstPad * pad,
1388 GstPadAcceptCapsFunction acceptcaps)
1390 g_return_if_fail (GST_IS_PAD (pad));
1392 GST_PAD_ACCEPTCAPSFUNC (pad) = acceptcaps;
1393 GST_CAT_DEBUG (GST_CAT_PADS, "acceptcapsfunc for %s:%s set to %s",
1394 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (acceptcaps));
1398 * gst_pad_set_fixatecaps_function:
1400 * @fixatecaps: the #GstPadFixateCapsFunction to set.
1402 * Sets the given fixatecaps function for the pad. The fixatecaps function
1403 * will be called whenever the default values for a GstCaps needs to be
1407 gst_pad_set_fixatecaps_function (GstPad * pad,
1408 GstPadFixateCapsFunction fixatecaps)
1410 g_return_if_fail (GST_IS_PAD (pad));
1412 GST_PAD_FIXATECAPSFUNC (pad) = fixatecaps;
1413 GST_CAT_DEBUG (GST_CAT_PADS, "fixatecapsfunc for %s:%s set to %s",
1414 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (fixatecaps));
1418 * gst_pad_set_setcaps_function:
1420 * @setcaps: the #GstPadSetCapsFunction to set.
1422 * Sets the given setcaps function for the pad. The setcaps function
1423 * will be called whenever a buffer with a new media type is pushed or
1424 * pulled from the pad. The pad/element needs to update its internal
1425 * structures to process the new media type. If this new type is not
1426 * acceptable, the setcaps function should return FALSE.
1429 gst_pad_set_setcaps_function (GstPad * pad, GstPadSetCapsFunction setcaps)
1431 g_return_if_fail (GST_IS_PAD (pad));
1433 GST_PAD_SETCAPSFUNC (pad) = setcaps;
1434 GST_CAT_DEBUG (GST_CAT_PADS, "setcapsfunc for %s:%s set to %s",
1435 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (setcaps));
1439 * gst_pad_set_bufferalloc_function:
1440 * @pad: a sink #GstPad.
1441 * @bufalloc: the #GstPadBufferAllocFunction to set.
1443 * Sets the given bufferalloc function for the pad. Note that the
1444 * bufferalloc function can only be set on sinkpads.
1447 gst_pad_set_bufferalloc_function (GstPad * pad,
1448 GstPadBufferAllocFunction bufalloc)
1450 g_return_if_fail (GST_IS_PAD (pad));
1451 g_return_if_fail (GST_PAD_IS_SINK (pad));
1453 GST_PAD_BUFFERALLOCFUNC (pad) = bufalloc;
1454 GST_CAT_DEBUG (GST_CAT_PADS, "bufferallocfunc for %s:%s set to %s",
1455 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (bufalloc));
1460 * @srcpad: the source #GstPad to unlink.
1461 * @sinkpad: the sink #GstPad to unlink.
1463 * Unlinks the source pad from the sink pad. Will emit the "unlinked" signal on
1466 * Returns: TRUE if the pads were unlinked. This function returns FALSE if
1467 * the pads were not linked together.
1472 gst_pad_unlink (GstPad * srcpad, GstPad * sinkpad)
1474 g_return_val_if_fail (GST_IS_PAD (srcpad), FALSE);
1475 g_return_val_if_fail (GST_IS_PAD (sinkpad), FALSE);
1477 GST_CAT_INFO (GST_CAT_ELEMENT_PADS, "unlinking %s:%s(%p) and %s:%s(%p)",
1478 GST_DEBUG_PAD_NAME (srcpad), srcpad,
1479 GST_DEBUG_PAD_NAME (sinkpad), sinkpad);
1481 GST_OBJECT_LOCK (srcpad);
1483 if (G_UNLIKELY (GST_PAD_DIRECTION (srcpad) != GST_PAD_SRC))
1486 GST_OBJECT_LOCK (sinkpad);
1488 if (G_UNLIKELY (GST_PAD_DIRECTION (sinkpad) != GST_PAD_SINK))
1491 if (G_UNLIKELY (GST_PAD_PEER (srcpad) != sinkpad))
1492 goto not_linked_together;
1494 if (GST_PAD_UNLINKFUNC (srcpad)) {
1495 GST_PAD_UNLINKFUNC (srcpad) (srcpad);
1497 if (GST_PAD_UNLINKFUNC (sinkpad)) {
1498 GST_PAD_UNLINKFUNC (sinkpad) (sinkpad);
1501 /* first clear peers */
1502 GST_PAD_PEER (srcpad) = NULL;
1503 GST_PAD_PEER (sinkpad) = NULL;
1505 GST_OBJECT_UNLOCK (sinkpad);
1506 GST_OBJECT_UNLOCK (srcpad);
1508 /* fire off a signal to each of the pads telling them
1509 * that they've been unlinked */
1510 g_signal_emit (G_OBJECT (srcpad), gst_pad_signals[PAD_UNLINKED], 0, sinkpad);
1511 g_signal_emit (G_OBJECT (sinkpad), gst_pad_signals[PAD_UNLINKED], 0, srcpad);
1513 GST_CAT_INFO (GST_CAT_ELEMENT_PADS, "unlinked %s:%s and %s:%s",
1514 GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (sinkpad));
1520 g_critical ("pad %s is not a source pad", GST_PAD_NAME (srcpad));
1521 GST_OBJECT_UNLOCK (srcpad);
1526 g_critical ("pad %s is not a sink pad", GST_PAD_NAME (sinkpad));
1527 GST_OBJECT_UNLOCK (sinkpad);
1528 GST_OBJECT_UNLOCK (srcpad);
1531 not_linked_together:
1533 /* we do not emit a warning in this case because unlinking cannot
1534 * be made MT safe.*/
1535 GST_OBJECT_UNLOCK (sinkpad);
1536 GST_OBJECT_UNLOCK (srcpad);
1542 * gst_pad_is_linked:
1543 * @pad: pad to check
1545 * Checks if a @pad is linked to another pad or not.
1547 * Returns: TRUE if the pad is linked, FALSE otherwise.
1552 gst_pad_is_linked (GstPad * pad)
1556 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
1558 GST_OBJECT_LOCK (pad);
1559 result = (GST_PAD_PEER (pad) != NULL);
1560 GST_OBJECT_UNLOCK (pad);
1565 /* get the caps from both pads and see if the intersection
1568 * This function should be called with the pad LOCK on both
1572 gst_pad_link_check_compatible_unlocked (GstPad * src, GstPad * sink)
1578 srccaps = gst_pad_get_caps_unlocked (src);
1579 sinkcaps = gst_pad_get_caps_unlocked (sink);
1581 GST_CAT_DEBUG (GST_CAT_CAPS, "src caps %" GST_PTR_FORMAT, srccaps);
1582 GST_CAT_DEBUG (GST_CAT_CAPS, "sink caps %" GST_PTR_FORMAT, sinkcaps);
1584 /* if we have caps on both pads we can check the intersection. If one
1585 * of the caps is NULL, we return TRUE. */
1586 if (srccaps == NULL || sinkcaps == NULL)
1589 icaps = gst_caps_intersect (srccaps, sinkcaps);
1590 gst_caps_unref (srccaps);
1591 gst_caps_unref (sinkcaps);
1596 GST_CAT_DEBUG (GST_CAT_CAPS,
1597 "intersection caps %p %" GST_PTR_FORMAT, icaps, icaps);
1599 if (gst_caps_is_empty (icaps))
1602 gst_caps_unref (icaps);
1607 /* incompatible cases */
1610 GST_CAT_DEBUG (GST_CAT_CAPS, "intersection gave NULL");
1615 GST_CAT_DEBUG (GST_CAT_CAPS, "intersection is EMPTY");
1616 gst_caps_unref (icaps);
1621 /* check if the grandparents of both pads are the same.
1622 * This check is required so that we don't try to link
1623 * pads from elements in different bins without ghostpads.
1625 * The LOCK should be helt on both pads
1628 gst_pad_link_check_hierarchy (GstPad * src, GstPad * sink)
1630 GstObject *psrc, *psink;
1631 gboolean res = TRUE;
1633 psrc = GST_OBJECT_PARENT (src);
1634 psink = GST_OBJECT_PARENT (sink);
1636 /* if one of the pads has no parent, we allow the link */
1637 if (psrc && psink) {
1638 /* if the parents are the same, we have a loop */
1639 if (psrc == psink) {
1640 GST_CAT_DEBUG (GST_CAT_CAPS, "pads have same parent %" GST_PTR_FORMAT,
1645 /* if they both have a parent, we check the grandparents */
1646 psrc = gst_object_get_parent (psrc);
1647 psink = gst_object_get_parent (psink);
1649 if (psrc != psink) {
1650 /* if they have grandparents but they are not the same */
1651 GST_CAT_DEBUG (GST_CAT_CAPS,
1652 "pads have different grandparents %" GST_PTR_FORMAT " and %"
1653 GST_PTR_FORMAT, psrc, psink);
1657 gst_object_unref (psrc);
1659 gst_object_unref (psink);
1665 /* FIXME leftover from an attempt at refactoring... */
1666 /* call with the two pads unlocked */
1667 static GstPadLinkReturn
1668 gst_pad_link_prepare (GstPad * srcpad, GstPad * sinkpad)
1670 /* generic checks */
1671 g_return_val_if_fail (GST_IS_PAD (srcpad), GST_PAD_LINK_REFUSED);
1672 g_return_val_if_fail (GST_IS_PAD (sinkpad), GST_PAD_LINK_REFUSED);
1674 GST_CAT_INFO (GST_CAT_PADS, "trying to link %s:%s and %s:%s",
1675 GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (sinkpad));
1677 GST_OBJECT_LOCK (srcpad);
1679 if (G_UNLIKELY (GST_PAD_DIRECTION (srcpad) != GST_PAD_SRC))
1682 if (G_UNLIKELY (GST_PAD_PEER (srcpad) != NULL))
1683 goto src_was_linked;
1685 GST_OBJECT_LOCK (sinkpad);
1687 if (G_UNLIKELY (GST_PAD_DIRECTION (sinkpad) != GST_PAD_SINK))
1690 if (G_UNLIKELY (GST_PAD_PEER (sinkpad) != NULL))
1691 goto sink_was_linked;
1693 /* check hierarchy, pads can only be linked if the grandparents
1695 if (!gst_pad_link_check_hierarchy (srcpad, sinkpad))
1696 goto wrong_hierarchy;
1698 /* check pad caps for non-empty intersection */
1699 if (!gst_pad_link_check_compatible_unlocked (srcpad, sinkpad))
1702 /* FIXME check pad scheduling for non-empty intersection */
1704 return GST_PAD_LINK_OK;
1708 g_critical ("pad %s is not a source pad", GST_PAD_NAME (srcpad));
1709 GST_OBJECT_UNLOCK (srcpad);
1710 return GST_PAD_LINK_WRONG_DIRECTION;
1714 GST_CAT_INFO (GST_CAT_PADS, "src %s:%s was already linked to %s:%s",
1715 GST_DEBUG_PAD_NAME (srcpad),
1716 GST_DEBUG_PAD_NAME (GST_PAD_PEER (srcpad)));
1717 /* we do not emit a warning in this case because unlinking cannot
1718 * be made MT safe.*/
1719 GST_OBJECT_UNLOCK (srcpad);
1720 return GST_PAD_LINK_WAS_LINKED;
1724 g_critical ("pad %s is not a sink pad", GST_PAD_NAME (sinkpad));
1725 GST_OBJECT_UNLOCK (sinkpad);
1726 GST_OBJECT_UNLOCK (srcpad);
1727 return GST_PAD_LINK_WRONG_DIRECTION;
1731 GST_CAT_INFO (GST_CAT_PADS, "sink %s:%s was already linked to %s:%s",
1732 GST_DEBUG_PAD_NAME (sinkpad),
1733 GST_DEBUG_PAD_NAME (GST_PAD_PEER (sinkpad)));
1734 /* we do not emit a warning in this case because unlinking cannot
1735 * be made MT safe.*/
1736 GST_OBJECT_UNLOCK (sinkpad);
1737 GST_OBJECT_UNLOCK (srcpad);
1738 return GST_PAD_LINK_WAS_LINKED;
1742 GST_CAT_INFO (GST_CAT_PADS, "pads have wrong hierarchy");
1743 GST_OBJECT_UNLOCK (sinkpad);
1744 GST_OBJECT_UNLOCK (srcpad);
1745 return GST_PAD_LINK_WRONG_HIERARCHY;
1749 GST_CAT_INFO (GST_CAT_PADS, "caps are incompatible");
1750 GST_OBJECT_UNLOCK (sinkpad);
1751 GST_OBJECT_UNLOCK (srcpad);
1752 return GST_PAD_LINK_NOFORMAT;
1758 * @srcpad: the source #GstPad to link.
1759 * @sinkpad: the sink #GstPad to link.
1761 * Links the source pad and the sink pad.
1763 * Returns: A result code indicating if the connection worked or
1769 gst_pad_link (GstPad * srcpad, GstPad * sinkpad)
1771 GstPadLinkReturn result;
1773 /* prepare will also lock the two pads */
1774 result = gst_pad_link_prepare (srcpad, sinkpad);
1776 if (result != GST_PAD_LINK_OK)
1777 goto prepare_failed;
1779 /* must set peers before calling the link function */
1780 GST_PAD_PEER (srcpad) = sinkpad;
1781 GST_PAD_PEER (sinkpad) = srcpad;
1783 GST_OBJECT_UNLOCK (sinkpad);
1784 GST_OBJECT_UNLOCK (srcpad);
1786 /* FIXME released the locks here, concurrent thread might link
1787 * something else. */
1788 if (GST_PAD_LINKFUNC (srcpad)) {
1789 /* this one will call the peer link function */
1790 result = GST_PAD_LINKFUNC (srcpad) (srcpad, sinkpad);
1791 } else if (GST_PAD_LINKFUNC (sinkpad)) {
1792 /* if no source link function, we need to call the sink link
1793 * function ourselves. */
1794 result = GST_PAD_LINKFUNC (sinkpad) (sinkpad, srcpad);
1796 result = GST_PAD_LINK_OK;
1799 GST_OBJECT_LOCK (srcpad);
1800 GST_OBJECT_LOCK (sinkpad);
1802 if (result == GST_PAD_LINK_OK) {
1803 GST_OBJECT_UNLOCK (sinkpad);
1804 GST_OBJECT_UNLOCK (srcpad);
1806 /* fire off a signal to each of the pads telling them
1807 * that they've been linked */
1808 g_signal_emit (G_OBJECT (srcpad), gst_pad_signals[PAD_LINKED], 0, sinkpad);
1809 g_signal_emit (G_OBJECT (sinkpad), gst_pad_signals[PAD_LINKED], 0, srcpad);
1811 GST_CAT_INFO (GST_CAT_PADS, "linked %s:%s and %s:%s, successful",
1812 GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (sinkpad));
1814 GST_CAT_INFO (GST_CAT_PADS, "link between %s:%s and %s:%s failed",
1815 GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (sinkpad));
1817 GST_PAD_PEER (srcpad) = NULL;
1818 GST_PAD_PEER (sinkpad) = NULL;
1820 GST_OBJECT_UNLOCK (sinkpad);
1821 GST_OBJECT_UNLOCK (srcpad);
1832 gst_pad_set_pad_template (GstPad * pad, GstPadTemplate * templ)
1834 GstPadTemplate **template_p;
1836 /* this function would need checks if it weren't static */
1838 GST_OBJECT_LOCK (pad);
1839 template_p = &pad->padtemplate;
1840 gst_object_replace ((GstObject **) template_p, (GstObject *) templ);
1841 GST_OBJECT_UNLOCK (pad);
1844 gst_pad_template_pad_created (templ, pad);
1848 * gst_pad_get_pad_template:
1851 * Gets the template for @pad.
1853 * Returns: the #GstPadTemplate from which this pad was instantiated, or %NULL
1854 * if this pad has no template.
1856 * FIXME: currently returns an unrefcounted padtemplate.
1859 gst_pad_get_pad_template (GstPad * pad)
1861 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
1863 return GST_PAD_PAD_TEMPLATE (pad);
1867 /* should be called with the pad LOCK held */
1868 /* refs the caps, so caller is responsible for getting it unreffed */
1870 gst_pad_get_caps_unlocked (GstPad * pad)
1872 GstCaps *result = NULL;
1874 GST_CAT_DEBUG (GST_CAT_CAPS, "get pad caps of %s:%s (%p)",
1875 GST_DEBUG_PAD_NAME (pad), pad);
1877 if (GST_PAD_GETCAPSFUNC (pad)) {
1878 GST_CAT_DEBUG (GST_CAT_CAPS, "dispatching to pad getcaps function");
1880 GST_OBJECT_FLAG_SET (pad, GST_PAD_IN_GETCAPS);
1881 GST_OBJECT_UNLOCK (pad);
1882 result = GST_PAD_GETCAPSFUNC (pad) (pad);
1883 GST_OBJECT_LOCK (pad);
1884 GST_OBJECT_FLAG_UNSET (pad, GST_PAD_IN_GETCAPS);
1886 if (result == NULL) {
1887 g_critical ("pad %s:%s returned NULL caps from getcaps function",
1888 GST_DEBUG_PAD_NAME (pad));
1890 GST_CAT_DEBUG (GST_CAT_CAPS,
1891 "pad getcaps %s:%s returned %" GST_PTR_FORMAT,
1892 GST_DEBUG_PAD_NAME (pad), result);
1893 #ifndef G_DISABLE_ASSERT
1894 /* check that the returned caps are a real subset of the template caps */
1895 if (GST_PAD_PAD_TEMPLATE (pad)) {
1896 const GstCaps *templ_caps =
1897 GST_PAD_TEMPLATE_CAPS (GST_PAD_PAD_TEMPLATE (pad));
1898 if (!gst_caps_is_subset (result, templ_caps)) {
1901 GST_CAT_ERROR_OBJECT (GST_CAT_CAPS, pad,
1902 "pad returned caps %" GST_PTR_FORMAT
1903 " which are not a real subset of its template caps %"
1904 GST_PTR_FORMAT, result, templ_caps);
1906 ("pad %s:%s returned caps that are not a real subset of its template caps",
1907 GST_DEBUG_PAD_NAME (pad));
1908 temp = gst_caps_intersect (templ_caps, result);
1909 gst_caps_unref (result);
1917 if (GST_PAD_PAD_TEMPLATE (pad)) {
1918 GstPadTemplate *templ = GST_PAD_PAD_TEMPLATE (pad);
1920 result = GST_PAD_TEMPLATE_CAPS (templ);
1921 GST_CAT_DEBUG (GST_CAT_CAPS,
1922 "using pad template %p with caps %p %" GST_PTR_FORMAT, templ, result,
1925 result = gst_caps_ref (result);
1928 if (GST_PAD_CAPS (pad)) {
1929 result = GST_PAD_CAPS (pad);
1931 GST_CAT_DEBUG (GST_CAT_CAPS,
1932 "using pad caps %p %" GST_PTR_FORMAT, result, result);
1934 result = gst_caps_ref (result);
1938 GST_CAT_DEBUG (GST_CAT_CAPS, "pad has no caps");
1939 result = gst_caps_new_empty ();
1947 * @pad: a #GstPad to get the capabilities of.
1949 * Gets the capabilities this pad can produce or consume.
1950 * Note that this method doesn't necessarily return the caps set by
1951 * gst_pad_set_caps() - use #GST_PAD_CAPS for that instead.
1952 * gst_pad_get_caps returns all possible caps a pad can operate with, using
1953 * the pad's get_caps function;
1954 * this returns the pad template caps if not explicitly set.
1956 * Returns: a newly allocated copy of the #GstCaps of this pad.
1961 gst_pad_get_caps (GstPad * pad)
1963 GstCaps *result = NULL;
1965 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
1967 GST_OBJECT_LOCK (pad);
1969 GST_CAT_DEBUG (GST_CAT_CAPS, "get pad caps of %s:%s (%p)",
1970 GST_DEBUG_PAD_NAME (pad), pad);
1972 result = gst_pad_get_caps_unlocked (pad);
1973 GST_OBJECT_UNLOCK (pad);
1979 * gst_pad_peer_get_caps:
1980 * @pad: a #GstPad to get the peer capabilities of.
1982 * Gets the capabilities of the peer connected to this pad.
1984 * Returns: the #GstCaps of the peer pad. This function returns a new caps, so use
1985 * gst_caps_unref to get rid of it. this function returns NULL if there is no
1989 gst_pad_peer_get_caps (GstPad * pad)
1992 GstCaps *result = NULL;
1994 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
1996 GST_OBJECT_LOCK (pad);
1998 GST_CAT_DEBUG (GST_CAT_CAPS, "get peer caps of %s:%s (%p)",
1999 GST_DEBUG_PAD_NAME (pad), pad);
2001 peerpad = GST_PAD_PEER (pad);
2002 if (G_UNLIKELY (peerpad == NULL))
2005 gst_object_ref (peerpad);
2006 GST_OBJECT_UNLOCK (pad);
2008 result = gst_pad_get_caps (peerpad);
2010 gst_object_unref (peerpad);
2016 GST_OBJECT_UNLOCK (pad);
2022 fixate_value (GValue * dest, const GValue * src)
2024 if (G_VALUE_TYPE (src) == GST_TYPE_INT_RANGE) {
2025 g_value_init (dest, G_TYPE_INT);
2026 g_value_set_int (dest, gst_value_get_int_range_min (src));
2027 } else if (G_VALUE_TYPE (src) == GST_TYPE_DOUBLE_RANGE) {
2028 g_value_init (dest, G_TYPE_DOUBLE);
2029 g_value_set_double (dest, gst_value_get_double_range_min (src));
2030 } else if (G_VALUE_TYPE (src) == GST_TYPE_FRACTION_RANGE) {
2031 gst_value_init_and_copy (dest, gst_value_get_fraction_range_min (src));
2032 } else if (G_VALUE_TYPE (src) == GST_TYPE_LIST) {
2033 GValue temp = { 0 };
2035 gst_value_init_and_copy (&temp, gst_value_list_get_value (src, 0));
2036 if (!fixate_value (dest, &temp))
2037 gst_value_init_and_copy (dest, &temp);
2038 g_value_unset (&temp);
2039 } else if (G_VALUE_TYPE (src) == GST_TYPE_ARRAY) {
2040 gboolean res = FALSE;
2043 g_value_init (dest, GST_TYPE_ARRAY);
2044 for (n = 0; n < gst_value_array_get_size (src); n++) {
2046 const GValue *orig_kid = gst_value_array_get_value (src, n);
2048 if (!fixate_value (&kid, orig_kid))
2049 gst_value_init_and_copy (&kid, orig_kid);
2052 gst_value_array_append_value (dest, &kid);
2053 g_value_unset (&kid);
2057 g_value_unset (dest);
2068 gst_pad_default_fixate (GQuark field_id, const GValue * value, gpointer data)
2070 GstStructure *s = data;
2073 if (fixate_value (&v, value)) {
2074 gst_structure_id_set_value (s, field_id, &v);
2082 * gst_pad_fixate_caps:
2083 * @pad: a #GstPad to fixate
2084 * @caps: the #GstCaps to fixate
2086 * Fixate a caps on the given pad. Modifies the caps in place, so you should
2087 * make sure that the caps are actually writable (see gst_caps_make_writable()).
2090 gst_pad_fixate_caps (GstPad * pad, GstCaps * caps)
2092 GstPadFixateCapsFunction fixatefunc;
2095 g_return_if_fail (GST_IS_PAD (pad));
2096 g_return_if_fail (caps != NULL);
2098 if (gst_caps_is_fixed (caps))
2101 fixatefunc = GST_PAD_FIXATECAPSFUNC (pad);
2103 fixatefunc (pad, caps);
2106 /* default fixation */
2107 for (n = 0; n < gst_caps_get_size (caps); n++) {
2108 GstStructure *s = gst_caps_get_structure (caps, n);
2110 gst_structure_foreach (s, gst_pad_default_fixate, s);
2114 /* Default accept caps implementation just checks against
2115 * against the allowed caps for the pad */
2117 gst_pad_acceptcaps_default (GstPad * pad, GstCaps * caps)
2119 /* get the caps and see if it intersects to something
2123 gboolean result = FALSE;
2125 allowed = gst_pad_get_caps (pad);
2127 intersect = gst_caps_intersect (allowed, caps);
2129 result = !gst_caps_is_empty (intersect);
2131 gst_caps_unref (allowed);
2132 gst_caps_unref (intersect);
2139 * gst_pad_accept_caps:
2140 * @pad: a #GstPad to check
2141 * @caps: a #GstCaps to check on the pad
2143 * Check if the given pad accepts the caps.
2145 * Returns: TRUE if the pad can accept the caps.
2148 gst_pad_accept_caps (GstPad * pad, GstCaps * caps)
2151 GstPadAcceptCapsFunction acceptfunc;
2152 GstCaps *existing = NULL;
2154 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2156 /* any pad can be unnegotiated */
2160 GST_OBJECT_LOCK (pad);
2161 acceptfunc = GST_PAD_ACCEPTCAPSFUNC (pad);
2162 if (GST_PAD_CAPS (pad) != NULL)
2163 existing = gst_caps_ref (GST_PAD_CAPS (pad));
2165 GST_CAT_DEBUG (GST_CAT_CAPS, "pad accept caps of %s:%s (%p)",
2166 GST_DEBUG_PAD_NAME (pad), pad);
2167 GST_OBJECT_UNLOCK (pad);
2169 /* The current caps on a pad are trivially acceptable */
2171 if (caps == existing || gst_caps_is_equal (caps, existing))
2173 gst_caps_unref (existing);
2176 if (G_LIKELY (acceptfunc)) {
2177 /* we can call the function */
2178 result = acceptfunc (pad, caps);
2180 /* Only null if the element explicitly unset it */
2181 result = gst_pad_acceptcaps_default (pad, caps);
2186 gst_caps_unref (existing);
2191 * gst_pad_peer_accept_caps:
2192 * @pad: a #GstPad to check
2193 * @caps: a #GstCaps to check on the pad
2195 * Check if the given pad accepts the caps.
2197 * Returns: TRUE if the pad can accept the caps.
2200 gst_pad_peer_accept_caps (GstPad * pad, GstCaps * caps)
2205 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2207 GST_OBJECT_LOCK (pad);
2209 GST_CAT_DEBUG (GST_CAT_CAPS, "peer accept caps of %s:%s (%p)",
2210 GST_DEBUG_PAD_NAME (pad), pad);
2212 peerpad = GST_PAD_PEER (pad);
2213 if (G_UNLIKELY (peerpad == NULL))
2216 result = gst_pad_accept_caps (peerpad, caps);
2217 GST_OBJECT_UNLOCK (pad);
2223 GST_OBJECT_UNLOCK (pad);
2230 * @pad: a #GstPad to set the capabilities of.
2231 * @caps: a #GstCaps to set.
2233 * Sets the capabilities of this pad. The caps must be fixed. Any previous
2234 * caps on the pad will be unreffed. This function refs the caps so you should
2235 * unref if as soon as you don't need it anymore.
2236 * It is possible to set NULL caps, which will make the pad unnegotiated
2239 * Returns: TRUE if the caps could be set. FALSE if the caps were not fixed
2240 * or bad parameters were provided to this function.
2245 gst_pad_set_caps (GstPad * pad, GstCaps * caps)
2247 GstPadSetCapsFunction setcaps;
2250 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2251 g_return_val_if_fail (caps == NULL || gst_caps_is_fixed (caps), FALSE);
2253 GST_OBJECT_LOCK (pad);
2254 setcaps = GST_PAD_SETCAPSFUNC (pad);
2256 existing = GST_PAD_CAPS (pad);
2257 if (existing == caps) {
2258 GST_OBJECT_UNLOCK (pad);
2262 if (gst_caps_is_equal (caps, existing))
2263 goto setting_same_caps;
2265 /* call setcaps function to configure the pad only if the
2266 * caps is not NULL */
2267 if (setcaps != NULL && caps) {
2268 if (!GST_PAD_IS_IN_SETCAPS (pad)) {
2269 GST_OBJECT_FLAG_SET (pad, GST_PAD_IN_SETCAPS);
2270 GST_OBJECT_UNLOCK (pad);
2271 if (!setcaps (pad, caps))
2273 GST_OBJECT_LOCK (pad);
2274 GST_OBJECT_FLAG_UNSET (pad, GST_PAD_IN_SETCAPS);
2276 GST_CAT_DEBUG (GST_CAT_CAPS, "pad %s:%s was dispatching",
2277 GST_DEBUG_PAD_NAME (pad));
2281 gst_caps_replace (&GST_PAD_CAPS (pad), caps);
2282 GST_CAT_DEBUG (GST_CAT_CAPS, "%s:%s caps %" GST_PTR_FORMAT,
2283 GST_DEBUG_PAD_NAME (pad), caps);
2284 GST_OBJECT_UNLOCK (pad);
2286 g_object_notify (G_OBJECT (pad), "caps");
2292 gst_caps_replace (&GST_PAD_CAPS (pad), caps);
2293 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
2294 "caps %" GST_PTR_FORMAT " same as existing, updating ptr only", caps);
2295 GST_OBJECT_UNLOCK (pad);
2302 GST_OBJECT_LOCK (pad);
2303 GST_OBJECT_FLAG_UNSET (pad, GST_PAD_IN_SETCAPS);
2304 GST_CAT_DEBUG (GST_CAT_CAPS,
2305 "pad %s:%s, caps %" GST_PTR_FORMAT " could not be set",
2306 GST_DEBUG_PAD_NAME (pad), caps);
2307 GST_OBJECT_UNLOCK (pad);
2314 gst_pad_configure_sink (GstPad * pad, GstCaps * caps)
2316 GstPadSetCapsFunction setcaps;
2319 setcaps = GST_PAD_SETCAPSFUNC (pad);
2321 /* See if pad accepts the caps - only needed if
2322 * no setcaps function */
2323 if (setcaps == NULL)
2324 if (!gst_pad_accept_caps (pad, caps))
2327 /* set caps on pad if call succeeds */
2328 res = gst_pad_set_caps (pad, caps);
2329 /* no need to unref the caps here, set_caps takes a ref and
2330 * our ref goes away when we leave this function. */
2336 GST_CAT_DEBUG (GST_CAT_CAPS, "caps %" GST_PTR_FORMAT " not accepted", caps);
2341 /* returns TRUE if the src pad could be configured to accept the given caps */
2343 gst_pad_configure_src (GstPad * pad, GstCaps * caps, gboolean dosetcaps)
2345 GstPadSetCapsFunction setcaps;
2348 setcaps = GST_PAD_SETCAPSFUNC (pad);
2350 /* See if pad accepts the caps - only needed if
2351 * no setcaps function */
2352 if (setcaps == NULL)
2353 if (!gst_pad_accept_caps (pad, caps))
2357 res = gst_pad_set_caps (pad, caps);
2365 GST_CAT_DEBUG (GST_CAT_CAPS, "caps %" GST_PTR_FORMAT " not accepted", caps);
2371 * gst_pad_get_pad_template_caps:
2372 * @pad: a #GstPad to get the template capabilities from.
2374 * Gets the capabilities for @pad's template.
2376 * Returns: the #GstCaps of this pad template. If you intend to keep a reference
2377 * on the caps, make a copy (see gst_caps_copy ()).
2380 gst_pad_get_pad_template_caps (GstPad * pad)
2382 static GstStaticCaps anycaps = GST_STATIC_CAPS ("ANY");
2384 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2386 if (GST_PAD_PAD_TEMPLATE (pad))
2387 return GST_PAD_TEMPLATE_CAPS (GST_PAD_PAD_TEMPLATE (pad));
2389 return gst_static_caps_get (&anycaps);
2395 * @pad: a #GstPad to get the peer of.
2397 * Gets the peer of @pad. This function refs the peer pad so
2398 * you need to unref it after use.
2400 * Returns: the peer #GstPad. Unref after usage.
2405 gst_pad_get_peer (GstPad * pad)
2409 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2411 GST_OBJECT_LOCK (pad);
2412 result = GST_PAD_PEER (pad);
2414 gst_object_ref (result);
2415 GST_OBJECT_UNLOCK (pad);
2421 * gst_pad_get_allowed_caps:
2422 * @srcpad: a #GstPad, it must a a source pad.
2424 * Gets the capabilities of the allowed media types that can flow through
2425 * @srcpad and its peer. The pad must be a source pad.
2426 * The caller must free the resulting caps.
2428 * Returns: the allowed #GstCaps of the pad link. Free the caps when
2429 * you no longer need it. This function returns NULL when the @srcpad has no
2435 gst_pad_get_allowed_caps (GstPad * srcpad)
2442 g_return_val_if_fail (GST_IS_PAD (srcpad), NULL);
2443 g_return_val_if_fail (GST_PAD_IS_SRC (srcpad), NULL);
2445 GST_OBJECT_LOCK (srcpad);
2447 peer = GST_PAD_PEER (srcpad);
2448 if (G_UNLIKELY (peer == NULL))
2451 GST_CAT_DEBUG (GST_CAT_PROPERTIES, "%s:%s: getting allowed caps",
2452 GST_DEBUG_PAD_NAME (srcpad));
2454 gst_object_ref (peer);
2455 GST_OBJECT_UNLOCK (srcpad);
2456 mycaps = gst_pad_get_caps (srcpad);
2458 peercaps = gst_pad_get_caps (peer);
2459 gst_object_unref (peer);
2461 caps = gst_caps_intersect (mycaps, peercaps);
2462 gst_caps_unref (peercaps);
2463 gst_caps_unref (mycaps);
2465 GST_CAT_DEBUG (GST_CAT_CAPS, "allowed caps %" GST_PTR_FORMAT, caps);
2471 GST_CAT_DEBUG (GST_CAT_PROPERTIES, "%s:%s: no peer",
2472 GST_DEBUG_PAD_NAME (srcpad));
2473 GST_OBJECT_UNLOCK (srcpad);
2480 * gst_pad_get_negotiated_caps:
2483 * Gets the capabilities of the media type that currently flows through @pad
2486 * This function can be used on both src and sinkpads. Note that srcpads are
2487 * always negotiated before sinkpads so it is possible that the negotiated caps
2488 * on the srcpad do not match the negotiated caps of the peer.
2490 * Returns: the negotiated #GstCaps of the pad link. Free the caps when
2491 * you no longer need it. This function returns NULL when the @pad has no
2492 * peer or is not negotiated yet.
2497 gst_pad_get_negotiated_caps (GstPad * pad)
2502 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2504 GST_OBJECT_LOCK (pad);
2506 if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
2509 GST_CAT_DEBUG (GST_CAT_PROPERTIES, "%s:%s: getting negotiated caps",
2510 GST_DEBUG_PAD_NAME (pad));
2512 caps = GST_PAD_CAPS (pad);
2514 gst_caps_ref (caps);
2515 GST_OBJECT_UNLOCK (pad);
2517 GST_CAT_DEBUG (GST_CAT_CAPS, "negotiated caps %" GST_PTR_FORMAT, caps);
2523 GST_CAT_DEBUG (GST_CAT_PROPERTIES, "%s:%s: no peer",
2524 GST_DEBUG_PAD_NAME (pad));
2525 GST_OBJECT_UNLOCK (pad);
2531 static GstFlowReturn
2532 gst_pad_alloc_buffer_full (GstPad * pad, guint64 offset, gint size,
2533 GstCaps * caps, GstBuffer ** buf, gboolean setcaps)
2537 GstPadBufferAllocFunction bufferallocfunc;
2538 gboolean caps_changed;
2540 g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
2541 g_return_val_if_fail (GST_PAD_IS_SRC (pad), GST_FLOW_ERROR);
2542 g_return_val_if_fail (buf != NULL, GST_FLOW_ERROR);
2544 GST_OBJECT_LOCK (pad);
2545 while (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad)))
2546 if ((ret = handle_pad_block (pad)) != GST_FLOW_OK)
2549 if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
2552 gst_object_ref (peer);
2553 GST_OBJECT_UNLOCK (pad);
2555 if (G_LIKELY ((bufferallocfunc = peer->bufferallocfunc) == NULL))
2558 GST_OBJECT_LOCK (peer);
2559 /* when the peer is flushing we cannot give a buffer */
2560 if (G_UNLIKELY (GST_PAD_IS_FLUSHING (peer)))
2563 if (offset == GST_BUFFER_OFFSET_NONE) {
2564 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
2565 "calling bufferallocfunc &%s (@%p) of peer pad %s:%s for size %d offset NONE",
2566 GST_DEBUG_FUNCPTR_NAME (bufferallocfunc),
2567 &bufferallocfunc, GST_DEBUG_PAD_NAME (peer), size);
2569 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
2570 "calling bufferallocfunc &%s (@%p) of peer pad %s:%s for size %d offset %"
2571 G_GUINT64_FORMAT, GST_DEBUG_FUNCPTR_NAME (bufferallocfunc),
2572 &bufferallocfunc, GST_DEBUG_PAD_NAME (peer), size, offset);
2574 GST_OBJECT_UNLOCK (peer);
2576 ret = bufferallocfunc (peer, offset, size, caps, buf);
2578 if (G_UNLIKELY (ret != GST_FLOW_OK))
2580 if (G_UNLIKELY (*buf == NULL))
2583 /* If the buffer alloc function didn't set up the caps like it should,
2585 if (caps && (GST_BUFFER_CAPS (*buf) == NULL)) {
2586 GST_WARNING ("Buffer allocation function for pad % " GST_PTR_FORMAT
2587 " did not set up caps. Setting", peer);
2589 gst_buffer_set_caps (*buf, caps);
2593 gst_object_unref (peer);
2595 /* FIXME, move capnego this into a base class? */
2596 caps = GST_BUFFER_CAPS (*buf);
2597 caps_changed = caps && caps != GST_PAD_CAPS (pad);
2598 /* we got a new datatype on the pad, see if it can handle it */
2599 if (G_UNLIKELY (caps_changed)) {
2600 GST_DEBUG_OBJECT (pad, "caps changed to %" GST_PTR_FORMAT, caps);
2601 if (G_UNLIKELY (!gst_pad_configure_src (pad, caps, setcaps)))
2602 goto not_negotiated;
2608 GST_CAT_DEBUG (GST_CAT_PADS, "%s:%s pad block stopped by flush",
2609 GST_DEBUG_PAD_NAME (pad));
2610 GST_OBJECT_UNLOCK (pad);
2615 /* pad has no peer */
2616 GST_CAT_DEBUG (GST_CAT_PADS,
2617 "%s:%s called bufferallocfunc but had no peer",
2618 GST_DEBUG_PAD_NAME (pad));
2619 GST_OBJECT_UNLOCK (pad);
2620 return GST_FLOW_NOT_LINKED;
2624 /* peer was flushing */
2625 GST_OBJECT_UNLOCK (peer);
2626 gst_object_unref (peer);
2627 GST_CAT_DEBUG (GST_CAT_PADS,
2628 "%s:%s called bufferallocfunc but peer was flushing",
2629 GST_DEBUG_PAD_NAME (pad));
2630 return GST_FLOW_WRONG_STATE;
2632 /* fallback case, allocate a buffer of our own, add pad caps. */
2635 GST_CAT_DEBUG (GST_CAT_PADS,
2636 "%s:%s fallback buffer alloc", GST_DEBUG_PAD_NAME (pad));
2637 *buf = gst_buffer_new_and_alloc (size);
2638 GST_BUFFER_OFFSET (*buf) = offset;
2639 gst_buffer_set_caps (*buf, caps);
2647 gst_buffer_unref (*buf);
2649 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
2650 "alloc function returned unacceptable buffer");
2651 return GST_FLOW_NOT_NEGOTIATED;
2655 gst_object_unref (peer);
2656 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
2657 "alloc function returned error %s", gst_flow_get_name (ret));
2663 * gst_pad_alloc_buffer:
2664 * @pad: a source #GstPad
2665 * @offset: the offset of the new buffer in the stream
2666 * @size: the size of the new buffer
2667 * @caps: the caps of the new buffer
2668 * @buf: a newly allocated buffer
2670 * Allocates a new, empty buffer optimized to push to pad @pad. This
2671 * function only works if @pad is a source pad and has a peer.
2673 * A new, empty #GstBuffer will be put in the @buf argument.
2674 * You need to check the caps of the buffer after performing this
2675 * function and renegotiate to the format if needed.
2677 * Returns: a result code indicating success of the operation. Any
2678 * result code other than #GST_FLOW_OK is an error and @buf should
2680 * An error can occur if the pad is not connected or when the downstream
2681 * peer elements cannot provide an acceptable buffer.
2686 gst_pad_alloc_buffer (GstPad * pad, guint64 offset, gint size, GstCaps * caps,
2689 return gst_pad_alloc_buffer_full (pad, offset, size, caps, buf, FALSE);
2693 * gst_pad_alloc_buffer_and_set_caps:
2694 * @pad: a source #GstPad
2695 * @offset: the offset of the new buffer in the stream
2696 * @size: the size of the new buffer
2697 * @caps: the caps of the new buffer
2698 * @buf: a newly allocated buffer
2700 * In addition to the function gst_pad_alloc_buffer(), this function
2701 * automatically calls gst_pad_set_caps() when the caps of the
2702 * newly allocated buffer are different from the @pad caps.
2704 * Returns: a result code indicating success of the operation. Any
2705 * result code other than #GST_FLOW_OK is an error and @buf should
2707 * An error can occur if the pad is not connected or when the downstream
2708 * peer elements cannot provide an acceptable buffer.
2713 gst_pad_alloc_buffer_and_set_caps (GstPad * pad, guint64 offset, gint size,
2714 GstCaps * caps, GstBuffer ** buf)
2716 return gst_pad_alloc_buffer_full (pad, offset, size, caps, buf, TRUE);
2720 * gst_pad_get_internal_links_default:
2721 * @pad: the #GstPad to get the internal links of.
2723 * Gets a list of pads to which the given pad is linked to
2724 * inside of the parent element.
2725 * This is the default handler, and thus returns a list of all of the
2726 * pads inside the parent element with opposite direction.
2727 * The caller must free this list after use.
2729 * Returns: a newly allocated #GList of pads, or NULL if the pad has no parent.
2734 gst_pad_get_internal_links_default (GstPad * pad)
2739 GstPadDirection direction;
2741 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2743 direction = pad->direction;
2745 parent = GST_PAD_PARENT (pad);
2749 parent_pads = parent->pads;
2751 while (parent_pads) {
2752 GstPad *parent_pad = GST_PAD_CAST (parent_pads->data);
2754 if (parent_pad->direction != direction) {
2755 res = g_list_prepend (res, parent_pad);
2758 parent_pads = g_list_next (parent_pads);
2765 * gst_pad_get_internal_links:
2766 * @pad: the #GstPad to get the internal links of.
2768 * Gets a list of pads to which the given pad is linked to
2769 * inside of the parent element.
2770 * The caller must free this list after use.
2772 * Returns: a newly allocated #GList of pads.
2777 gst_pad_get_internal_links (GstPad * pad)
2781 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2783 if (GST_PAD_INTLINKFUNC (pad))
2784 res = GST_PAD_INTLINKFUNC (pad) (pad);
2791 gst_pad_event_default_dispatch (GstPad * pad, GstEvent * event)
2796 GST_INFO_OBJECT (pad, "Sending event %p to all internally linked pads",
2799 result = (GST_PAD_DIRECTION (pad) == GST_PAD_SINK);
2801 orig = pads = gst_pad_get_internal_links (pad);
2804 GstPad *eventpad = GST_PAD_CAST (pads->data);
2806 pads = g_list_next (pads);
2808 if (GST_PAD_DIRECTION (eventpad) == GST_PAD_SRC) {
2809 /* for each pad we send to, we should ref the event; it's up
2810 * to downstream to unref again when handled. */
2811 GST_LOG_OBJECT (pad, "Reffing and sending event %p (%s) to %s:%s",
2812 event, GST_EVENT_TYPE_NAME (event), GST_DEBUG_PAD_NAME (eventpad));
2813 gst_event_ref (event);
2814 gst_pad_push_event (eventpad, event);
2816 /* we only send the event on one pad, multi-sinkpad elements
2817 * should implement a handler */
2818 GST_LOG_OBJECT (pad, "sending event %p (%s) to one sink pad %s:%s",
2819 event, GST_EVENT_TYPE_NAME (event), GST_DEBUG_PAD_NAME (eventpad));
2820 result = gst_pad_push_event (eventpad, event);
2824 /* we handled the incoming event so we unref once */
2825 GST_LOG_OBJECT (pad, "handled event %p, unreffing", event);
2826 gst_event_unref (event);
2835 * gst_pad_event_default:
2836 * @pad: a #GstPad to call the default event handler on.
2837 * @event: the #GstEvent to handle.
2839 * Invokes the default event handler for the given pad. End-of-stream and
2840 * discontinuity events are handled specially, and then the event is sent to all
2841 * pads internally linked to @pad. Note that if there are many possible sink
2842 * pads that are internally linked to @pad, only one will be sent an event.
2843 * Multi-sinkpad elements should implement custom event handlers.
2845 * Returns: TRUE if the event was sent succesfully.
2848 gst_pad_event_default (GstPad * pad, GstEvent * event)
2850 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2851 g_return_val_if_fail (event != NULL, FALSE);
2853 switch (GST_EVENT_TYPE (event)) {
2856 GST_DEBUG_OBJECT (pad, "pausing task because of eos");
2857 gst_pad_pause_task (pad);
2863 return gst_pad_event_default_dispatch (pad, event);
2867 * gst_pad_dispatcher:
2868 * @pad: a #GstPad to dispatch.
2869 * @dispatch: the #GstDispatcherFunction to call.
2870 * @data: gpointer user data passed to the dispatcher function.
2872 * Invokes the given dispatcher function on all pads that are
2873 * internally linked to the given pad.
2874 * The GstPadDispatcherFunction should return TRUE when no further pads
2875 * need to be processed.
2877 * Returns: TRUE if one of the dispatcher functions returned TRUE.
2880 gst_pad_dispatcher (GstPad * pad, GstPadDispatcherFunction dispatch,
2883 gboolean res = FALSE;
2884 GList *int_pads, *orig;
2886 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2887 g_return_val_if_fail (dispatch != NULL, FALSE);
2889 orig = int_pads = gst_pad_get_internal_links (pad);
2892 GstPad *int_pad = GST_PAD_CAST (int_pads->data);
2893 GstPad *int_peer = GST_PAD_PEER (int_pad);
2896 res = dispatch (int_peer, data);
2900 int_pads = g_list_next (int_pads);
2910 * @pad: a #GstPad to invoke the default query on.
2911 * @query: the #GstQuery to perform.
2913 * Dispatches a query to a pad. The query should have been allocated by the
2914 * caller via one of the type-specific allocation functions in gstquery.h. The
2915 * element is responsible for filling the query with an appropriate response,
2916 * which should then be parsed with a type-specific query parsing function.
2918 * Again, the caller is responsible for both the allocation and deallocation of
2919 * the query structure.
2921 * Returns: TRUE if the query could be performed.
2924 gst_pad_query (GstPad * pad, GstQuery * query)
2926 GstPadQueryFunction func;
2928 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2929 g_return_val_if_fail (GST_IS_QUERY (query), FALSE);
2931 GST_DEBUG ("sending query %p to pad %s:%s", query, GST_DEBUG_PAD_NAME (pad));
2933 if ((func = GST_PAD_QUERYFUNC (pad)) == NULL)
2936 return func (pad, query);
2940 GST_DEBUG ("pad had no query function");
2946 * gst_pad_query_default:
2947 * @pad: a #GstPad to call the default query handler on.
2948 * @query: the #GstQuery to handle.
2950 * Invokes the default query handler for the given pad.
2951 * The query is sent to all pads internally linked to @pad. Note that
2952 * if there are many possible sink pads that are internally linked to
2953 * @pad, only one will be sent the query.
2954 * Multi-sinkpad elements should implement custom query handlers.
2956 * Returns: TRUE if the query was performed succesfully.
2959 gst_pad_query_default (GstPad * pad, GstQuery * query)
2961 switch (GST_QUERY_TYPE (query)) {
2962 case GST_QUERY_POSITION:
2963 case GST_QUERY_SEEKING:
2964 case GST_QUERY_FORMATS:
2965 case GST_QUERY_LATENCY:
2966 case GST_QUERY_JITTER:
2967 case GST_QUERY_RATE:
2968 case GST_QUERY_CONVERT:
2970 return gst_pad_dispatcher
2971 (pad, (GstPadDispatcherFunction) gst_pad_query, query);
2975 #ifndef GST_DISABLE_LOADSAVE
2976 /* FIXME: why isn't this on a GstElement ? */
2978 * gst_pad_load_and_link:
2979 * @self: an #xmlNodePtr to read the description from.
2980 * @parent: the #GstObject element that owns the pad.
2982 * Reads the pad definition from the XML node and links the given pad
2983 * in the element to a pad of an element up in the hierarchy.
2986 gst_pad_load_and_link (xmlNodePtr self, GstObject * parent)
2988 xmlNodePtr field = self->xmlChildrenNode;
2989 GstPad *pad = NULL, *targetpad;
2993 GstObject *grandparent;
2997 if (!strcmp ((char *) field->name, "name")) {
2998 name = (gchar *) xmlNodeGetContent (field);
2999 pad = gst_element_get_pad (GST_ELEMENT (parent), name);
3001 } else if (!strcmp ((char *) field->name, "peer")) {
3002 peer = (gchar *) xmlNodeGetContent (field);
3004 field = field->next;
3006 g_return_if_fail (pad != NULL);
3011 split = g_strsplit (peer, ".", 2);
3013 if (split[0] == NULL || split[1] == NULL) {
3014 GST_CAT_DEBUG (GST_CAT_XML,
3015 "Could not parse peer '%s' for pad %s:%s, leaving unlinked",
3016 peer, GST_DEBUG_PAD_NAME (pad));
3023 g_return_if_fail (split[0] != NULL);
3024 g_return_if_fail (split[1] != NULL);
3026 grandparent = gst_object_get_parent (parent);
3028 if (grandparent && GST_IS_BIN (grandparent)) {
3029 target = gst_bin_get_by_name_recurse_up (GST_BIN (grandparent), split[0]);
3036 targetpad = gst_element_get_pad (target, split[1]);
3038 if (targetpad == NULL)
3041 gst_pad_link (pad, targetpad);
3048 * gst_pad_save_thyself:
3049 * @pad: a #GstPad to save.
3050 * @parent: the parent #xmlNodePtr to save the description in.
3052 * Saves the pad into an xml representation.
3054 * Returns: the #xmlNodePtr representation of the pad.
3057 gst_pad_save_thyself (GstObject * object, xmlNodePtr parent)
3062 g_return_val_if_fail (GST_IS_PAD (object), NULL);
3064 pad = GST_PAD (object);
3066 xmlNewChild (parent, NULL, (xmlChar *) "name",
3067 (xmlChar *) GST_PAD_NAME (pad));
3068 if (GST_PAD_PEER (pad) != NULL) {
3071 peer = GST_PAD_PEER (pad);
3072 /* first check to see if the peer's parent's parent is the same */
3073 /* we just save it off */
3074 content = g_strdup_printf ("%s.%s",
3075 GST_OBJECT_NAME (GST_PAD_PARENT (peer)), GST_PAD_NAME (peer));
3076 xmlNewChild (parent, NULL, (xmlChar *) "peer", (xmlChar *) content);
3079 xmlNewChild (parent, NULL, (xmlChar *) "peer", NULL);
3086 * gst_ghost_pad_save_thyself:
3087 * @pad: a ghost #GstPad to save.
3088 * @parent: the parent #xmlNodePtr to save the description in.
3090 * Saves the ghost pad into an xml representation.
3092 * Returns: the #xmlNodePtr representation of the pad.
3095 gst_ghost_pad_save_thyself (GstPad * pad, xmlNodePtr parent)
3099 g_return_val_if_fail (GST_IS_GHOST_PAD (pad), NULL);
3101 self = xmlNewChild (parent, NULL, (xmlChar *) "ghostpad", NULL);
3102 xmlNewChild (self, NULL, (xmlChar *) "name", (xmlChar *) GST_PAD_NAME (pad));
3103 xmlNewChild (self, NULL, (xmlChar *) "parent",
3104 (xmlChar *) GST_OBJECT_NAME (GST_PAD_PARENT (pad)));
3106 /* FIXME FIXME FIXME! */
3111 #endif /* GST_DISABLE_LOADSAVE */
3114 * should be called with pad OBJECT_LOCK and STREAM_LOCK helt.
3115 * GST_PAD_IS_BLOCK (pad) == TRUE when this function is
3118 * This function perform the pad blocking when an event, buffer push
3119 * or buffer_alloc is performed on a _SRC_ pad. It blocks the
3120 * streaming thread after informing the pad has been blocked.
3122 * An application can with this method wait and block any streaming
3123 * thread and perform operations such as seeking or linking.
3125 * Two methods are available for notifying the application of the
3127 * - the callback method, which happens in the STREAMING thread with
3128 * the STREAM_LOCK helt. With this method, the most usefull way of
3129 * dealing with the callback is to post a message to the main thread
3130 * where the pad block can then be handled outside of the streaming
3131 * thread. With the last method one can perform all operations such
3132 * as doing a state change, linking, unblocking, seeking etc on the
3134 * - the GCond signal method, which makes any thread unblock when
3135 * the pad block happens.
3139 static GstFlowReturn
3140 handle_pad_block (GstPad * pad)
3142 GstPadBlockCallback callback;
3144 GstFlowReturn ret = GST_FLOW_OK;
3146 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3147 "signal block taken on pad %s:%s", GST_DEBUG_PAD_NAME (pad));
3149 /* flushing, don't bother trying to block and return WRONG_STATE
3151 if (GST_PAD_IS_FLUSHING (pad))
3152 goto flushingnonref;
3154 /* we grab an extra ref for the callbacks, this is probably not
3155 * needed (callback code does not have a ref and cannot unref). I
3156 * think this was done to make it possible to unref the element in
3157 * the callback, which is in the end totally impossible as it
3158 * requires grabbing the STREAM_LOCK and OBJECT_LOCK which are
3159 * all taken when calling this function. */
3160 gst_object_ref (pad);
3162 /* we either have a callback installed to notify the block or
3163 * some other thread is doing a GCond wait. */
3164 callback = pad->block_callback;
3166 /* there is a callback installed, call it. We release the
3167 * lock so that the callback can do something usefull with the
3169 user_data = pad->block_data;
3170 GST_OBJECT_UNLOCK (pad);
3171 callback (pad, TRUE, user_data);
3172 GST_OBJECT_LOCK (pad);
3174 /* no callback, signal the thread that is doing a GCond wait
3176 GST_PAD_BLOCK_SIGNAL (pad);
3179 /* OBJECT_LOCK could have been released when we did the callback, which
3180 * then could have made the pad unblock so we need to check the blocking
3181 * condition again. */
3182 while (GST_PAD_IS_BLOCKED (pad)) {
3183 if (GST_PAD_IS_FLUSHING (pad))
3186 /* now we block the streaming thread. It can be unlocked when we
3187 * deactivate the pad (which will also set the FLUSHING flag) or
3188 * when the pad is unblocked. A flushing event will also unblock
3189 * the pad after setting the FLUSHING flag. */
3190 GST_PAD_BLOCK_WAIT (pad);
3192 /* see if we got unlocked by a flush or not */
3193 if (GST_PAD_IS_FLUSHING (pad))
3197 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "got unblocked");
3199 /* when we get here, the pad is unblocked again and we perform
3200 * the needed unblock code. */
3201 callback = pad->block_callback;
3203 /* we need to call the callback */
3204 user_data = pad->block_data;
3205 GST_OBJECT_UNLOCK (pad);
3206 callback (pad, FALSE, user_data);
3207 GST_OBJECT_LOCK (pad);
3209 /* we need to signal the thread waiting on the GCond */
3210 GST_PAD_BLOCK_SIGNAL (pad);
3213 gst_object_unref (pad);
3219 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3220 "pad %s:%s was flushing", GST_DEBUG_PAD_NAME (pad));
3221 return GST_FLOW_WRONG_STATE;
3225 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3226 "pad %s:%s became flushing", GST_DEBUG_PAD_NAME (pad));
3227 gst_object_unref (pad);
3228 return GST_FLOW_WRONG_STATE;
3232 /**********************************************************************
3233 * Data passing functions
3237 gst_pad_emit_have_data_signal (GstPad * pad, GstMiniObject * obj)
3240 GValue args[2] = { {0}, {0} };
3245 g_value_init (&ret, G_TYPE_BOOLEAN);
3246 g_value_set_boolean (&ret, TRUE);
3247 g_value_init (&args[0], GST_TYPE_PAD);
3248 g_value_set_object (&args[0], pad);
3249 g_value_init (&args[1], GST_TYPE_MINI_OBJECT); // G_TYPE_POINTER);
3250 gst_value_set_mini_object (&args[1], obj);
3252 if (GST_IS_EVENT (obj))
3253 detail = event_quark;
3255 detail = buffer_quark;
3258 g_signal_emitv (args, gst_pad_signals[PAD_HAVE_DATA], detail, &ret);
3259 res = g_value_get_boolean (&ret);
3262 g_value_unset (&ret);
3263 g_value_unset (&args[0]);
3264 g_value_unset (&args[1]);
3269 /* this is the chain function that does not perform the additional argument
3270 * checking for that little extra speed.
3272 static inline GstFlowReturn
3273 gst_pad_chain_unchecked (GstPad * pad, GstBuffer * buffer)
3276 gboolean caps_changed;
3277 GstPadChainFunction chainfunc;
3279 gboolean emit_signal;
3281 GST_PAD_STREAM_LOCK (pad);
3283 GST_OBJECT_LOCK (pad);
3284 if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad)))
3287 caps = GST_BUFFER_CAPS (buffer);
3288 caps_changed = caps && caps != GST_PAD_CAPS (pad);
3290 emit_signal = GST_PAD_DO_BUFFER_SIGNALS (pad) > 0;
3291 GST_OBJECT_UNLOCK (pad);
3293 /* see if the signal should be emited, we emit before caps nego as
3294 * we might drop the buffer and do capsnego for nothing. */
3295 if (G_UNLIKELY (emit_signal)) {
3296 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (buffer)))
3300 /* we got a new datatype on the pad, see if it can handle it */
3301 if (G_UNLIKELY (caps_changed)) {
3302 GST_DEBUG_OBJECT (pad, "caps changed to %" GST_PTR_FORMAT, caps);
3303 if (G_UNLIKELY (!gst_pad_configure_sink (pad, caps)))
3304 goto not_negotiated;
3307 /* NOTE: we read the chainfunc unlocked.
3308 * we cannot hold the lock for the pad so we might send
3309 * the data to the wrong function. This is not really a
3310 * problem since functions are assigned at creation time
3311 * and don't change that often... */
3312 if (G_UNLIKELY ((chainfunc = GST_PAD_CHAINFUNC (pad)) == NULL))
3315 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3316 "calling chainfunction &%s of pad %s:%s",
3317 GST_DEBUG_FUNCPTR_NAME (chainfunc), GST_DEBUG_PAD_NAME (pad));
3319 ret = chainfunc (pad, buffer);
3321 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3322 "called chainfunction &%s of pad %s:%s, returned %s",
3323 GST_DEBUG_FUNCPTR_NAME (chainfunc), GST_DEBUG_PAD_NAME (pad),
3324 gst_flow_get_name (ret));
3326 GST_PAD_STREAM_UNLOCK (pad);
3333 gst_buffer_unref (buffer);
3334 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3335 "pushing, but pad was flushing");
3336 GST_OBJECT_UNLOCK (pad);
3337 GST_PAD_STREAM_UNLOCK (pad);
3338 return GST_FLOW_WRONG_STATE;
3342 gst_buffer_unref (buffer);
3343 GST_DEBUG_OBJECT (pad, "Dropping buffer due to FALSE probe return");
3344 GST_PAD_STREAM_UNLOCK (pad);
3349 gst_buffer_unref (buffer);
3350 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3351 "pushing buffer but pad did not accept");
3352 GST_PAD_STREAM_UNLOCK (pad);
3353 return GST_FLOW_NOT_NEGOTIATED;
3357 gst_buffer_unref (buffer);
3358 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3359 "pushing, but not chainhandler");
3360 GST_ELEMENT_ERROR (GST_PAD_PARENT (pad), CORE, PAD, (NULL),
3361 ("push on pad %s:%s but it has no chainfunction",
3362 GST_DEBUG_PAD_NAME (pad)));
3363 GST_PAD_STREAM_UNLOCK (pad);
3364 return GST_FLOW_NOT_SUPPORTED;
3370 * @pad: a sink #GstPad, returns GST_FLOW_ERROR if not.
3371 * @buffer: the #GstBuffer to send, return GST_FLOW_ERROR if not.
3373 * Chain a buffer to @pad.
3375 * The function returns #GST_FLOW_WRONG_STATE if the pad was flushing.
3377 * If the caps on @buffer are different from the current caps on @pad, this
3378 * function will call any setcaps function (see gst_pad_set_setcaps_function())
3379 * installed on @pad. If the new caps are not acceptable for @pad, this function
3380 * returns #GST_FLOW_NOT_NEGOTIATED.
3382 * The function proceeds calling the chain function installed on @pad (see
3383 * gst_pad_set_chain_function()) and the return value of that function is
3384 * returned to the caller. #GST_FLOW_NOT_SUPPORTED is returned if @pad has no
3387 * In all cases, success or failure, the caller loses its reference to @buffer
3388 * after calling this function.
3390 * Returns: a #GstFlowReturn from the pad.
3395 gst_pad_chain (GstPad * pad, GstBuffer * buffer)
3397 g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
3398 g_return_val_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SINK,
3400 g_return_val_if_fail (GST_IS_BUFFER (buffer), GST_FLOW_ERROR);
3402 return gst_pad_chain_unchecked (pad, buffer);
3407 * @pad: a source #GstPad, returns #GST_FLOW_ERROR if not.
3408 * @buffer: the #GstBuffer to push returns GST_FLOW_ERROR if not.
3410 * Pushes a buffer to the peer of @pad.
3412 * This function will call an installed pad block before triggering any
3413 * installed pad probes.
3415 * If the caps on @buffer are different from the currently configured caps on
3416 * @pad, this function will call any installed setcaps function on @pad (see
3417 * gst_pad_set_setcaps_function()). In case of failure to renegotiate the new
3418 * format, this function returns #GST_FLOW_NOT_NEGOTIATED.
3420 * The function proceeds calling gst_pad_chain() on the peer pad and returns the
3421 * value from that function. If @pad has no peer, #GST_FLOW_NOT_LINKED will be
3424 * In all cases, success or failure, the caller loses its reference to @buffer
3425 * after calling this function.
3427 * Returns: a #GstFlowReturn from the peer pad.
3432 gst_pad_push (GstPad * pad, GstBuffer * buffer)
3438 gboolean caps_changed;
3440 g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
3441 g_return_val_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SRC, GST_FLOW_ERROR);
3442 g_return_val_if_fail (GST_IS_BUFFER (buffer), GST_FLOW_ERROR);
3444 GST_OBJECT_LOCK (pad);
3446 /* FIXME: this check can go away; pad_set_blocked could be implemented with
3447 * probes completely or probes with an extended pad block. */
3448 while (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad)))
3449 if ((ret = handle_pad_block (pad)) != GST_FLOW_OK)
3452 /* we emit signals on the pad arg, the peer will have a chance to
3453 * emit in the _chain() function */
3454 if (G_UNLIKELY (GST_PAD_DO_BUFFER_SIGNALS (pad) > 0)) {
3455 /* unlock before emitting */
3456 GST_OBJECT_UNLOCK (pad);
3458 /* if the signal handler returned FALSE, it means we should just drop the
3460 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (buffer)))
3463 GST_OBJECT_LOCK (pad);
3466 if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
3469 /* take ref to peer pad before releasing the lock */
3470 gst_object_ref (peer);
3472 /* Before pushing the buffer to the peer pad, ensure that caps
3473 * are set on this pad */
3474 caps = GST_BUFFER_CAPS (buffer);
3475 caps_changed = caps && caps != GST_PAD_CAPS (pad);
3477 GST_OBJECT_UNLOCK (pad);
3479 /* we got a new datatype from the pad, it had better handle it */
3480 if (G_UNLIKELY (caps_changed)) {
3481 GST_DEBUG_OBJECT (pad, "caps changed to %" GST_PTR_FORMAT, caps);
3482 if (G_UNLIKELY (!gst_pad_configure_src (pad, caps, TRUE)))
3483 goto not_negotiated;
3486 ret = gst_pad_chain_unchecked (peer, buffer);
3488 gst_object_unref (peer);
3492 /* ERROR recovery here */
3495 gst_buffer_unref (buffer);
3496 GST_DEBUG_OBJECT (pad, "pad block stopped by flush");
3497 GST_OBJECT_UNLOCK (pad);
3502 gst_buffer_unref (buffer);
3503 GST_DEBUG_OBJECT (pad, "Dropping buffer due to FALSE probe return");
3508 gst_buffer_unref (buffer);
3509 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3510 "pushing, but it was not linked");
3511 GST_OBJECT_UNLOCK (pad);
3512 return GST_FLOW_NOT_LINKED;
3516 gst_buffer_unref (buffer);
3517 gst_object_unref (peer);
3518 GST_CAT_DEBUG_OBJECT (GST_CAT_SCHEDULING, pad,
3519 "element pushed buffer then refused to accept the caps");
3520 return GST_FLOW_NOT_NEGOTIATED;
3525 * gst_pad_check_pull_range:
3526 * @pad: a sink #GstPad.
3528 * Checks if a gst_pad_pull_range() can be performed on the peer
3529 * source pad. This function is used by plugins that want to check
3530 * if they can use random access on the peer source pad.
3532 * The peer sourcepad can implement a custom #GstPadCheckGetRangeFunction
3533 * if it needs to perform some logic to determine if pull_range is
3536 * Returns: a gboolean with the result.
3541 gst_pad_check_pull_range (GstPad * pad)
3545 GstPadCheckGetRangeFunction checkgetrangefunc;
3547 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
3549 GST_OBJECT_LOCK (pad);
3550 if (GST_PAD_DIRECTION (pad) != GST_PAD_SINK)
3551 goto wrong_direction;
3553 if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
3556 gst_object_ref (peer);
3557 GST_OBJECT_UNLOCK (pad);
3559 /* see note in above function */
3560 if (G_LIKELY ((checkgetrangefunc = peer->checkgetrangefunc) == NULL)) {
3561 /* FIXME, kindoff ghetto */
3562 ret = GST_PAD_GETRANGEFUNC (peer) != NULL;
3564 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3565 "calling checkgetrangefunc %s of peer pad %s:%s",
3566 GST_DEBUG_FUNCPTR_NAME (checkgetrangefunc), GST_DEBUG_PAD_NAME (peer));
3568 ret = checkgetrangefunc (peer);
3571 gst_object_unref (peer);
3575 /* ERROR recovery here */
3578 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3579 "checking pull range, but pad must be a sinkpad");
3580 GST_OBJECT_UNLOCK (pad);
3585 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3586 "checking pull range, but it was not linked");
3587 GST_OBJECT_UNLOCK (pad);
3593 * gst_pad_get_range:
3594 * @pad: a src #GstPad, returns #GST_FLOW_ERROR if not.
3595 * @offset: The start offset of the buffer
3596 * @size: The length of the buffer
3597 * @buffer: a pointer to hold the #GstBuffer, returns #GST_FLOW_ERROR if %NULL.
3599 * When @pad is flushing this function returns #GST_FLOW_WRONG_STATE
3602 * Calls the getrange function of @pad, see #GstPadGetRangeFunction for a
3603 * description of a getrange function. If @pad has no getrange function
3604 * installed (see gst_pad_set_getrange_function()) this function returns
3605 * #GST_FLOW_NOT_SUPPORTED.
3607 * Returns: a #GstFlowReturn from the pad.
3612 gst_pad_get_range (GstPad * pad, guint64 offset, guint size,
3613 GstBuffer ** buffer)
3616 GstPadGetRangeFunction getrangefunc;
3617 gboolean emit_signal;
3619 g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
3620 g_return_val_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SRC, GST_FLOW_ERROR);
3621 g_return_val_if_fail (buffer != NULL, GST_FLOW_ERROR);
3623 GST_PAD_STREAM_LOCK (pad);
3625 GST_OBJECT_LOCK (pad);
3626 if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad)))
3629 emit_signal = GST_PAD_DO_BUFFER_SIGNALS (pad) > 0;
3630 GST_OBJECT_UNLOCK (pad);
3632 if (G_UNLIKELY ((getrangefunc = GST_PAD_GETRANGEFUNC (pad)) == NULL))
3635 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3636 "calling getrangefunc %s of peer pad %s:%s, offset %"
3637 G_GUINT64_FORMAT ", size %u",
3638 GST_DEBUG_FUNCPTR_NAME (getrangefunc), GST_DEBUG_PAD_NAME (pad),
3641 ret = getrangefunc (pad, offset, size, buffer);
3643 /* can only fire the signal if we have a valid buffer */
3644 if (G_UNLIKELY (emit_signal) && (ret == GST_FLOW_OK)) {
3645 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (*buffer)))
3649 GST_PAD_STREAM_UNLOCK (pad);
3656 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3657 "pulling range, but pad was flushing");
3658 GST_OBJECT_UNLOCK (pad);
3659 GST_PAD_STREAM_UNLOCK (pad);
3660 return GST_FLOW_WRONG_STATE;
3664 GST_ELEMENT_ERROR (GST_PAD_PARENT (pad), CORE, PAD, (NULL),
3665 ("pullrange on pad %s:%s but it has no getrangefunction",
3666 GST_DEBUG_PAD_NAME (pad)));
3667 GST_PAD_STREAM_UNLOCK (pad);
3668 return GST_FLOW_NOT_SUPPORTED;
3672 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3673 "Dropping data after FALSE probe return");
3674 GST_PAD_STREAM_UNLOCK (pad);
3675 gst_buffer_unref (*buffer);
3677 return GST_FLOW_UNEXPECTED;
3683 * gst_pad_pull_range:
3684 * @pad: a sink #GstPad, returns GST_FLOW_ERROR if not.
3685 * @offset: The start offset of the buffer
3686 * @size: The length of the buffer
3687 * @buffer: a pointer to hold the #GstBuffer, returns GST_FLOW_ERROR if %NULL.
3689 * Pulls a buffer from the peer pad.
3691 * This function will first trigger the pad block signal if it was
3694 * When @pad is not linked #GST_FLOW_NOT_LINKED is returned else this
3695 * function returns the result of gst_pad_get_range() on the peer pad.
3696 * See gst_pad_get_range() for a list of return values and for the
3697 * semantics of the arguments of this function.
3699 * Returns: a #GstFlowReturn from the peer pad.
3700 * When this function returns #GST_FLOW_OK, @buffer will contain a valid
3701 * #GstBuffer that should be freed with gst_buffer_unref() after usage.
3702 * @buffer may not be used or freed when any other return value than
3703 * #GST_FLOW_OK is returned.
3708 gst_pad_pull_range (GstPad * pad, guint64 offset, guint size,
3709 GstBuffer ** buffer)
3713 gboolean emit_signal;
3715 g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
3716 g_return_val_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SINK,
3718 g_return_val_if_fail (buffer != NULL, GST_FLOW_ERROR);
3720 GST_OBJECT_LOCK (pad);
3722 while (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad)))
3723 handle_pad_block (pad);
3725 if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
3728 /* signal emision for the pad, peer has chance to emit when
3729 * we call _get_range() */
3730 emit_signal = GST_PAD_DO_BUFFER_SIGNALS (pad) > 0;
3732 gst_object_ref (peer);
3733 GST_OBJECT_UNLOCK (pad);
3735 ret = gst_pad_get_range (peer, offset, size, buffer);
3737 gst_object_unref (peer);
3739 /* can only fire the signal if we have a valid buffer */
3740 if (G_UNLIKELY (emit_signal) && (ret == GST_FLOW_OK)) {
3741 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (*buffer)))
3746 /* ERROR recovery here */
3749 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3750 "pulling range, but it was not linked");
3751 GST_OBJECT_UNLOCK (pad);
3752 return GST_FLOW_NOT_LINKED;
3756 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3757 "Dropping data after FALSE probe return");
3758 gst_buffer_unref (*buffer);
3760 return GST_FLOW_UNEXPECTED;
3765 * gst_pad_push_event:
3766 * @pad: a #GstPad to push the event to.
3767 * @event: the #GstEvent to send to the pad.
3769 * Sends the event to the peer of the given pad. This function is
3770 * mainly used by elements to send events to their peer
3773 * This function takes owership of the provided event so you should
3774 * gst_event_ref() it if you want to reuse the event after this call.
3776 * Returns: TRUE if the event was handled.
3781 gst_pad_push_event (GstPad * pad, GstEvent * event)
3786 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
3787 g_return_val_if_fail (event != NULL, FALSE);
3788 g_return_val_if_fail (GST_IS_EVENT (event), FALSE);
3790 GST_LOG_OBJECT (pad, "event:%s", GST_EVENT_TYPE_NAME (event));
3792 GST_OBJECT_LOCK (pad);
3794 /* Two checks to be made:
3795 * . (un)set the FLUSHING flag for flushing events,
3796 * . handle pad blocking */
3797 switch (GST_EVENT_TYPE (event)) {
3798 case GST_EVENT_FLUSH_START:
3799 GST_PAD_SET_FLUSHING (pad);
3801 if (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad))) {
3802 /* flush start will have set the FLUSHING flag and will then
3803 * unlock all threads doing a GCond wait on the blocked pad. This
3804 * will typically unblock the STREAMING thread blocked on a pad. */
3805 GST_PAD_BLOCK_SIGNAL (pad);
3809 case GST_EVENT_FLUSH_STOP:
3810 GST_PAD_UNSET_FLUSHING (pad);
3812 if (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad)))
3816 if (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad))) {
3817 if (GST_PAD_IS_FLUSHING (pad))
3819 while (GST_PAD_IS_BLOCKED (pad))
3820 /* else block the event as long as the pad is blocked */
3821 if (handle_pad_block (pad) != GST_FLOW_OK)
3827 if (G_UNLIKELY (GST_PAD_DO_EVENT_SIGNALS (pad) > 0)) {
3828 GST_OBJECT_UNLOCK (pad);
3830 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (event)))
3833 GST_OBJECT_LOCK (pad);
3835 peerpad = GST_PAD_PEER (pad);
3836 if (peerpad == NULL)
3839 GST_LOG_OBJECT (peerpad, "sending event on peerpad");
3840 gst_object_ref (peerpad);
3841 GST_OBJECT_UNLOCK (pad);
3843 result = gst_pad_send_event (peerpad, event);
3845 gst_object_unref (peerpad);
3846 GST_LOG_OBJECT (peerpad, "sent event on peerpad");
3850 /* ERROR handling */
3853 GST_DEBUG_OBJECT (pad, "Dropping event after FALSE probe return");
3854 gst_event_unref (event);
3859 GST_DEBUG_OBJECT (pad, "Dropping event because pad is not linked");
3860 gst_event_unref (event);
3861 GST_OBJECT_UNLOCK (pad);
3867 GST_DEBUG_OBJECT (pad,
3868 "Not forwarding event since we're flushing and blocking");
3869 gst_event_unref (event);
3870 GST_OBJECT_UNLOCK (pad);
3876 * gst_pad_send_event:
3877 * @pad: a #GstPad to send the event to.
3878 * @event: the #GstEvent to send to the pad.
3880 * Sends the event to the pad. This function can be used
3881 * by applications to send events in the pipeline.
3883 * If @pad is a source pad, @event should be an upstream event. If @pad is a
3884 * sink pad, @event should be a downstream event. For example, you would not
3885 * send a #GST_EVENT_EOS on a src pad; EOS events only propagate downstream.
3886 * Furthermore, some downstream events have to be serialized with data flow,
3887 * like EOS, while some can travel out-of-band, like #GST_EVENT_FLUSH_START. If
3888 * the event needs to be serialized with data flow, this function will take the
3889 * pad's stream lock while calling its event function.
3891 * To find out whether an event type is upstream, downstream, or downstream and
3892 * serialized, see #GstEventTypeFlags, gst_event_type_get_flags(),
3893 * #GST_EVENT_IS_UPSTREAM, #GST_EVENT_IS_DOWNSTREAM, and
3894 * #GST_EVENT_IS_SERIALIZED. Note that in practice that an application or plugin
3895 * doesn't need to bother itself with this information; the core handles all
3896 * necessary locks and checks.
3898 * This function takes owership of the provided event so you should
3899 * gst_event_ref() it if you want to reuse the event after this call.
3901 * Returns: TRUE if the event was handled.
3904 gst_pad_send_event (GstPad * pad, GstEvent * event)
3906 gboolean result = FALSE;
3907 GstPadEventFunction eventfunc;
3908 gboolean serialized, need_unlock = FALSE;
3910 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
3911 g_return_val_if_fail (event != NULL, FALSE);
3913 GST_OBJECT_LOCK (pad);
3914 if (GST_PAD_IS_SINK (pad)) {
3915 if (G_UNLIKELY (!GST_EVENT_IS_DOWNSTREAM (event)))
3916 goto wrong_direction;
3917 serialized = GST_EVENT_IS_SERIALIZED (event);
3918 } else if (GST_PAD_IS_SRC (pad)) {
3919 if (G_UNLIKELY (!GST_EVENT_IS_UPSTREAM (event)))
3920 goto wrong_direction;
3921 /* events on srcpad never are serialized */
3924 goto unknown_direction;
3926 if (G_UNLIKELY (GST_EVENT_SRC (event) == NULL)) {
3927 GST_LOG_OBJECT (pad, "event had no source, setting pad as event source");
3928 GST_EVENT_SRC (event) = gst_object_ref (pad);
3932 if (G_UNLIKELY (GST_PAD_DO_EVENT_SIGNALS (pad) > 0)) {
3933 GST_OBJECT_UNLOCK (pad);
3935 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT_CAST (event)))
3938 GST_OBJECT_LOCK (pad);
3941 switch (GST_EVENT_TYPE (event)) {
3942 case GST_EVENT_FLUSH_START:
3943 GST_CAT_DEBUG (GST_CAT_EVENT,
3944 "have event type %d (FLUSH_START) on pad %s:%s",
3945 GST_EVENT_TYPE (event), GST_DEBUG_PAD_NAME (pad));
3947 /* can't even accept a flush begin event when flushing */
3948 if (GST_PAD_IS_FLUSHING (pad))
3950 GST_PAD_SET_FLUSHING (pad);
3951 GST_CAT_DEBUG (GST_CAT_EVENT, "set flush flag");
3953 case GST_EVENT_FLUSH_STOP:
3954 GST_PAD_UNSET_FLUSHING (pad);
3955 GST_CAT_DEBUG (GST_CAT_EVENT, "cleared flush flag");
3956 GST_OBJECT_UNLOCK (pad);
3957 /* grab stream lock */
3958 GST_PAD_STREAM_LOCK (pad);
3960 GST_OBJECT_LOCK (pad);
3963 GST_CAT_DEBUG (GST_CAT_EVENT, "have event type %s on pad %s:%s",
3964 GST_EVENT_TYPE_NAME (event), GST_DEBUG_PAD_NAME (pad));
3966 /* make this a little faster, no point in grabbing the lock
3967 * if the pad is allready flushing. */
3968 if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad)))
3972 /* lock order: STREAM_LOCK, LOCK */
3973 GST_OBJECT_UNLOCK (pad);
3974 GST_PAD_STREAM_LOCK (pad);
3976 GST_OBJECT_LOCK (pad);
3977 if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad)))
3982 if (G_UNLIKELY ((eventfunc = GST_PAD_EVENTFUNC (pad)) == NULL))
3985 GST_OBJECT_UNLOCK (pad);
3987 result = eventfunc (pad, event);
3990 GST_PAD_STREAM_UNLOCK (pad);
3994 /* ERROR handling */
3997 g_warning ("pad %s:%s sending %s event in wrong direction",
3998 GST_DEBUG_PAD_NAME (pad), GST_EVENT_TYPE_NAME (event));
3999 GST_OBJECT_UNLOCK (pad);
4000 gst_event_unref (event);
4005 g_warning ("pad %s:%s has invalid direction", GST_DEBUG_PAD_NAME (pad));
4006 GST_OBJECT_UNLOCK (pad);
4007 gst_event_unref (event);
4012 g_warning ("pad %s:%s has no event handler, file a bug.",
4013 GST_DEBUG_PAD_NAME (pad));
4014 GST_OBJECT_UNLOCK (pad);
4015 gst_event_unref (event);
4020 GST_OBJECT_UNLOCK (pad);
4022 GST_PAD_STREAM_UNLOCK (pad);
4023 GST_CAT_INFO (GST_CAT_EVENT, "Received event on flushing pad. Discarding");
4024 gst_event_unref (event);
4029 GST_DEBUG ("Dropping event after FALSE probe return");
4030 gst_event_unref (event);
4036 * gst_pad_set_element_private:
4037 * @pad: the #GstPad to set the private data of.
4038 * @priv: The private data to attach to the pad.
4040 * Set the given private data gpointer on the pad.
4041 * This function can only be used by the element that owns the pad.
4042 * No locking is performed in this function.
4045 gst_pad_set_element_private (GstPad * pad, gpointer priv)
4047 pad->element_private = priv;
4051 * gst_pad_get_element_private:
4052 * @pad: the #GstPad to get the private data of.
4054 * Gets the private data of a pad.
4055 * No locking is performed in this function.
4057 * Returns: a #gpointer to the private data.
4060 gst_pad_get_element_private (GstPad * pad)
4062 return pad->element_private;
4066 * gst_pad_start_task:
4067 * @pad: the #GstPad to start the task of
4068 * @func: the task function to call
4069 * @data: data passed to the task function
4071 * Starts a task that repeadedly calls @func with @data. This function
4072 * is nostly used in the pad activation function to start the
4073 * dataflow. This function will automatically acquire the STREAM_LOCK of
4074 * the pad before calling @func.
4076 * Returns: a TRUE if the task could be started.
4079 gst_pad_start_task (GstPad * pad, GstTaskFunction func, gpointer data)
4083 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
4084 g_return_val_if_fail (func != NULL, FALSE);
4086 GST_OBJECT_LOCK (pad);
4087 task = GST_PAD_TASK (pad);
4089 task = gst_task_create (func, data);
4090 gst_task_set_lock (task, GST_PAD_GET_STREAM_LOCK (pad));
4091 GST_PAD_TASK (pad) = task;
4093 gst_task_start (task);
4094 GST_OBJECT_UNLOCK (pad);
4100 * gst_pad_pause_task:
4101 * @pad: the #GstPad to pause the task of
4103 * Pause the task of @pad. This function will also make sure that the
4104 * function executed by the task will effectively stop.
4106 * Returns: a TRUE if the task could be paused or FALSE when the pad
4110 gst_pad_pause_task (GstPad * pad)
4114 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
4116 GST_OBJECT_LOCK (pad);
4117 task = GST_PAD_TASK (pad);
4120 gst_task_pause (task);
4121 GST_OBJECT_UNLOCK (pad);
4123 GST_PAD_STREAM_LOCK (pad);
4124 GST_PAD_STREAM_UNLOCK (pad);
4130 GST_DEBUG_OBJECT (pad, "pad has no task");
4131 GST_OBJECT_UNLOCK (pad);
4137 * gst_pad_stop_task:
4138 * @pad: the #GstPad to stop the task of
4140 * Stop the task of @pad. This function will also make sure that the
4141 * function executed by the task will effectively stop if not called
4142 * from the GstTaskFunction.
4144 * This function will deadlock if called from the GstTaskFunction of
4145 * the task. Use gst_task_pause() instead.
4147 * Regardless of whether the pad has a task, the stream lock is acquired and
4148 * released so as to ensure that streaming through this pad has finished.
4150 * Returns: a TRUE if the task could be stopped or FALSE on error.
4153 gst_pad_stop_task (GstPad * pad)
4157 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
4159 GST_OBJECT_LOCK (pad);
4160 task = GST_PAD_TASK (pad);
4163 GST_PAD_TASK (pad) = NULL;
4164 gst_task_stop (task);
4165 GST_OBJECT_UNLOCK (pad);
4167 GST_PAD_STREAM_LOCK (pad);
4168 GST_PAD_STREAM_UNLOCK (pad);
4170 gst_task_join (task);
4172 gst_object_unref (task);
4178 GST_OBJECT_UNLOCK (pad);
4180 GST_PAD_STREAM_LOCK (pad);
4181 GST_PAD_STREAM_UNLOCK (pad);