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 /* FIXME, Make G_PARAM_CONSTRUCT_ONLY when we fix ghostpads. */
317 g_object_class_install_property (gobject_class, PAD_PROP_TEMPLATE,
318 g_param_spec_object ("template", "Template",
319 "The GstPadTemplate of this pad", GST_TYPE_PAD_TEMPLATE,
322 #ifndef GST_DISABLE_LOADSAVE
323 gstobject_class->save_thyself = GST_DEBUG_FUNCPTR (gst_pad_save_thyself);
325 gstobject_class->path_string_separator = ".";
327 klass->have_data = default_have_data;
331 gst_pad_init (GstPad * pad)
333 GST_PAD_DIRECTION (pad) = GST_PAD_UNKNOWN;
334 GST_PAD_PEER (pad) = NULL;
336 GST_PAD_CHAINFUNC (pad) = NULL;
338 GST_PAD_LINKFUNC (pad) = NULL;
340 GST_PAD_CAPS (pad) = NULL;
341 GST_PAD_GETCAPSFUNC (pad) = NULL;
343 GST_PAD_ACTIVATEFUNC (pad) = GST_DEBUG_FUNCPTR (gst_pad_activate_default);
344 GST_PAD_EVENTFUNC (pad) = GST_DEBUG_FUNCPTR (gst_pad_event_default);
345 GST_PAD_QUERYTYPEFUNC (pad) =
346 GST_DEBUG_FUNCPTR (gst_pad_get_query_types_default);
347 GST_PAD_QUERYFUNC (pad) = GST_DEBUG_FUNCPTR (gst_pad_query_default);
348 GST_PAD_INTLINKFUNC (pad) =
349 GST_DEBUG_FUNCPTR (gst_pad_get_internal_links_default);
350 GST_PAD_ACCEPTCAPSFUNC (pad) = GST_DEBUG_FUNCPTR (gst_pad_acceptcaps_default);
352 pad->do_buffer_signals = 0;
353 pad->do_event_signals = 0;
355 GST_PAD_SET_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_OBJECT (GST_CAT_REFCOUNTING, pad, "dispose");
373 /* we don't hold a ref to the peer so we can just set the
375 GST_PAD_PEER (pad) = NULL;
378 gst_caps_replace (&GST_PAD_CAPS (pad), NULL);
380 gst_pad_set_pad_template (pad, NULL);
382 G_OBJECT_CLASS (parent_class)->dispose (object);
386 gst_pad_finalize (GObject * object)
388 GstPad *pad = GST_PAD (object);
391 /* in case the task is still around, clean it up */
392 if ((task = GST_PAD_TASK (pad))) {
393 gst_task_join (task);
394 GST_PAD_TASK (pad) = NULL;
395 gst_object_unref (task);
398 if (pad->stream_rec_lock) {
399 g_static_rec_mutex_free (pad->stream_rec_lock);
400 g_free (pad->stream_rec_lock);
401 pad->stream_rec_lock = NULL;
403 if (pad->preroll_lock) {
404 g_mutex_free (pad->preroll_lock);
405 g_cond_free (pad->preroll_cond);
406 pad->preroll_lock = NULL;
407 pad->preroll_cond = NULL;
409 if (pad->block_cond) {
410 g_cond_free (pad->block_cond);
411 pad->block_cond = NULL;
414 G_OBJECT_CLASS (parent_class)->finalize (object);
418 gst_pad_set_property (GObject * object, guint prop_id,
419 const GValue * value, GParamSpec * pspec)
421 g_return_if_fail (GST_IS_PAD (object));
424 case PAD_PROP_DIRECTION:
425 GST_PAD_DIRECTION (object) = g_value_get_enum (value);
427 case PAD_PROP_TEMPLATE:
428 gst_pad_set_pad_template (GST_PAD_CAST (object),
429 (GstPadTemplate *) g_value_get_object (value));
432 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
438 gst_pad_get_property (GObject * object, guint prop_id,
439 GValue * value, GParamSpec * pspec)
441 g_return_if_fail (GST_IS_PAD (object));
445 GST_OBJECT_LOCK (object);
446 g_value_set_boxed (value, GST_PAD_CAPS (object));
447 GST_OBJECT_UNLOCK (object);
449 case PAD_PROP_DIRECTION:
450 g_value_set_enum (value, GST_PAD_DIRECTION (object));
452 case PAD_PROP_TEMPLATE:
453 g_value_set_object (value, GST_PAD_PAD_TEMPLATE (object));
456 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
463 * @name: the name of the new pad.
464 * @direction: the #GstPadDirection of the pad.
466 * Creates a new pad with the given name in the given direction.
467 * If name is NULL, a guaranteed unique name (across all pads)
469 * This function makes a copy of the name so you can safely free the name.
471 * Returns: a new #GstPad, or NULL in case of an error.
476 gst_pad_new (const gchar * name, GstPadDirection direction)
478 return g_object_new (GST_TYPE_PAD,
479 "name", name, "direction", direction, NULL);
483 * gst_pad_new_from_template:
484 * @templ: the pad template to use
485 * @name: the name of the element
487 * Creates a new pad with the given name from the given template.
488 * If name is NULL, a guaranteed unique name (across all pads)
490 * This function makes a copy of the name so you can safely free the name.
492 * Returns: a new #GstPad, or NULL in case of an error.
495 gst_pad_new_from_template (GstPadTemplate * templ, const gchar * name)
497 g_return_val_if_fail (GST_IS_PAD_TEMPLATE (templ), NULL);
499 return g_object_new (GST_TYPE_PAD,
500 "name", name, "direction", templ->direction, "template", templ, NULL);
504 * gst_pad_new_from_static_template:
505 * @templ: the #GstStaticPadTemplate to use
506 * @name: the name of the element
508 * Creates a new pad with the given name from the given static template.
509 * If name is NULL, a guaranteed unique name (across all pads)
511 * This function makes a copy of the name so you can safely free the name.
513 * Returns: a new #GstPad, or NULL in case of an error.
516 gst_pad_new_from_static_template (GstStaticPadTemplate * templ,
520 GstPadTemplate *template;
522 template = gst_static_pad_template_get (templ);
523 pad = gst_pad_new_from_template (template, name);
524 gst_object_unref (template);
529 * gst_pad_get_direction:
530 * @pad: a #GstPad to get the direction of.
532 * Gets the direction of the pad. The direction of the pad is
533 * decided at construction time so this function does not take
536 * Returns: the #GstPadDirection of the pad.
541 gst_pad_get_direction (GstPad * pad)
543 GstPadDirection result;
545 /* PAD_UNKNOWN is a little silly but we need some sort of
546 * error return value */
547 g_return_val_if_fail (GST_IS_PAD (pad), GST_PAD_UNKNOWN);
549 GST_OBJECT_LOCK (pad);
550 result = GST_PAD_DIRECTION (pad);
551 GST_OBJECT_UNLOCK (pad);
557 gst_pad_activate_default (GstPad * pad)
559 return gst_pad_activate_push (pad, TRUE);
563 pre_activate (GstPad * pad, GstActivateMode new_mode)
566 case GST_ACTIVATE_PUSH:
567 case GST_ACTIVATE_PULL:
568 GST_OBJECT_LOCK (pad);
569 GST_DEBUG_OBJECT (pad, "setting ACTIVATE_MODE %d, unset flushing",
571 GST_PAD_UNSET_FLUSHING (pad);
572 GST_PAD_ACTIVATE_MODE (pad) = new_mode;
573 GST_OBJECT_UNLOCK (pad);
575 case GST_ACTIVATE_NONE:
576 GST_OBJECT_LOCK (pad);
577 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_BROADCAST (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:
664 GST_OBJECT_LOCK (pad);
666 g_critical ("Failed to deactivate pad %s:%s, very bad",
667 GST_DEBUG_PAD_NAME (pad));
669 GST_WARNING ("Failed to activate pad %s:%s", GST_DEBUG_PAD_NAME (pad));
671 GST_OBJECT_UNLOCK (pad);
678 * gst_pad_activate_pull:
679 * @pad: the #GstPad to activate or deactivate.
680 * @active: whether or not the pad should be active.
682 * Activates or deactivates the given pad in pull mode via dispatching to the
683 * pad's activatepullfunc. For use from within pad activation functions only.
684 * When called on sink pads, will first proxy the call to the peer pad, which is
685 * expected to activate its internally linked pads from within its activate_pull
688 * If you don't know what this is, you probably don't want to call it.
690 * Returns: TRUE if the operation was successful.
695 gst_pad_activate_pull (GstPad * pad, gboolean active)
697 GstActivateMode old, new;
700 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
702 GST_OBJECT_LOCK (pad);
703 old = GST_PAD_ACTIVATE_MODE (pad);
704 GST_OBJECT_UNLOCK (pad);
708 case GST_ACTIVATE_PULL:
710 case GST_ACTIVATE_PUSH:
711 /* pad was activate in the wrong direction, deactivate it
712 * and reactivate it in pull mode */
713 if (G_UNLIKELY (!gst_pad_activate_push (pad, FALSE)))
714 goto deactivate_failed;
715 /* fallthrough, pad is deactivated now. */
716 case GST_ACTIVATE_NONE:
721 case GST_ACTIVATE_NONE:
723 case GST_ACTIVATE_PUSH:
724 /* pad was activated in the other direction, deactivate it
725 * in push mode, this should not happen... */
726 if (G_UNLIKELY (!gst_pad_activate_push (pad, FALSE)))
727 goto deactivate_failed;
728 /* everything is fine now */
730 case GST_ACTIVATE_PULL:
735 if (gst_pad_get_direction (pad) == GST_PAD_SINK) {
736 if ((peer = gst_pad_get_peer (pad))) {
737 if (G_UNLIKELY (!gst_pad_activate_pull (peer, active)))
739 gst_object_unref (peer);
742 if (G_UNLIKELY (GST_PAD_GETRANGEFUNC (pad) == NULL))
743 goto failure; /* Can't activate pull on a src without a
747 new = active ? GST_ACTIVATE_PULL : GST_ACTIVATE_NONE;
748 pre_activate (pad, new);
750 if (GST_PAD_ACTIVATEPULLFUNC (pad)) {
751 if (G_UNLIKELY (!GST_PAD_ACTIVATEPULLFUNC (pad) (pad, active)))
754 /* can happen for sinks of passthrough elements */
757 post_activate (pad, new);
759 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "%s in pull mode",
760 active ? "activated" : "deactivated");
766 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "already %s in pull mode",
767 active ? "activated" : "deactivated");
772 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
773 "failed to %s in switch to pull from mode %d",
774 (active ? "activate" : "deactivate"), old);
779 GST_OBJECT_LOCK (peer);
780 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
781 "activate_pull on peer (%s:%s) failed", GST_DEBUG_PAD_NAME (peer));
782 GST_OBJECT_UNLOCK (peer);
783 gst_object_unref (peer);
788 GST_OBJECT_LOCK (pad);
789 GST_CAT_INFO_OBJECT (GST_CAT_PADS, pad, "failed to %s in pull mode",
790 active ? "activate" : "deactivate");
791 GST_PAD_SET_FLUSHING (pad);
792 GST_PAD_ACTIVATE_MODE (pad) = old;
793 GST_OBJECT_UNLOCK (pad);
799 * gst_pad_activate_push:
800 * @pad: the #GstPad to activate or deactivate.
801 * @active: whether the pad should be active or not.
803 * Activates or deactivates the given pad in push mode via dispatching to the
804 * pad's activatepushfunc. For use from within pad activation functions only.
806 * If you don't know what this is, you probably don't want to call it.
808 * Returns: %TRUE if the operation was successful.
813 gst_pad_activate_push (GstPad * pad, gboolean active)
815 GstActivateMode old, new;
817 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
818 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "trying to set %s in push mode",
819 active ? "activated" : "deactivated");
821 GST_OBJECT_LOCK (pad);
822 old = GST_PAD_ACTIVATE_MODE (pad);
823 GST_OBJECT_UNLOCK (pad);
827 case GST_ACTIVATE_PUSH:
829 case GST_ACTIVATE_PULL:
830 /* pad was activate in the wrong direction, deactivate it
831 * an reactivate it in push mode */
832 if (G_UNLIKELY (!gst_pad_activate_pull (pad, FALSE)))
833 goto deactivate_failed;
834 /* fallthrough, pad is deactivated now. */
835 case GST_ACTIVATE_NONE:
840 case GST_ACTIVATE_NONE:
842 case GST_ACTIVATE_PULL:
843 /* pad was activated in the other direction, deactivate it
844 * in pull mode, this should not happen... */
845 if (G_UNLIKELY (!gst_pad_activate_pull (pad, FALSE)))
846 goto deactivate_failed;
847 /* everything is fine now */
849 case GST_ACTIVATE_PUSH:
854 new = active ? GST_ACTIVATE_PUSH : GST_ACTIVATE_NONE;
855 pre_activate (pad, new);
857 if (GST_PAD_ACTIVATEPUSHFUNC (pad)) {
858 if (G_UNLIKELY (!GST_PAD_ACTIVATEPUSHFUNC (pad) (pad, active))) {
862 /* quite ok, element relies on state change func to prepare itself */
865 post_activate (pad, new);
867 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "%s in push mode",
868 active ? "activated" : "deactivated");
873 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "already %s in push mode",
874 active ? "activated" : "deactivated");
879 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
880 "failed to %s in switch to push from mode %d",
881 (active ? "activate" : "deactivate"), old);
886 GST_OBJECT_LOCK (pad);
887 GST_CAT_INFO_OBJECT (GST_CAT_PADS, pad, "failed to %s in push mode",
888 active ? "activate" : "deactivate");
889 GST_PAD_SET_FLUSHING (pad);
890 GST_PAD_ACTIVATE_MODE (pad) = old;
891 GST_OBJECT_UNLOCK (pad);
898 * @pad: the #GstPad to query
900 * Query if a pad is active
902 * Returns: TRUE if the pad is active.
907 gst_pad_is_active (GstPad * pad)
909 gboolean result = FALSE;
911 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
913 GST_OBJECT_LOCK (pad);
914 result = GST_PAD_MODE_ACTIVATE (GST_PAD_ACTIVATE_MODE (pad));
915 GST_OBJECT_UNLOCK (pad);
921 * gst_pad_set_blocked_async:
922 * @pad: the #GstPad to block or unblock
923 * @blocked: boolean indicating whether the pad should be blocked or unblocked
924 * @callback: #GstPadBlockCallback that will be called when the
926 * @user_data: user data passed to the callback
928 * Blocks or unblocks the dataflow on a pad. The provided callback
929 * is called when the operation succeeds; this happens right before the next
930 * attempt at pushing a buffer on the pad.
932 * This can take a while as the pad can only become blocked when real dataflow
934 * When the pipeline is stalled, for example in PAUSED, this can
935 * take an indeterminate amount of time.
936 * You can pass NULL as the callback to make this call block. Be careful with
937 * this blocking call as it might not return for reasons stated above.
939 * Returns: TRUE if the pad could be blocked. This function can fail
940 * if wrong parameters were passed or the pad was already in the
946 gst_pad_set_blocked_async (GstPad * pad, gboolean blocked,
947 GstPadBlockCallback callback, gpointer user_data)
949 gboolean was_blocked = FALSE;
951 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
953 GST_OBJECT_LOCK (pad);
955 was_blocked = GST_PAD_IS_BLOCKED (pad);
957 if (G_UNLIKELY (was_blocked == blocked))
958 goto had_right_state;
961 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "blocking pad");
963 GST_OBJECT_FLAG_SET (pad, GST_PAD_BLOCKED);
964 pad->block_callback = callback;
965 pad->block_data = user_data;
967 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "waiting for block");
968 GST_PAD_BLOCK_WAIT (pad);
969 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "blocked");
972 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "unblocking pad");
974 GST_OBJECT_FLAG_UNSET (pad, GST_PAD_BLOCKED);
976 pad->block_callback = callback;
977 pad->block_data = user_data;
979 GST_PAD_BLOCK_BROADCAST (pad);
981 /* no callback, wait for the unblock to happen */
982 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "waiting for unblock");
983 GST_PAD_BLOCK_WAIT (pad);
984 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "unblocked");
987 GST_OBJECT_UNLOCK (pad);
993 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
994 "pad was in right state (%d)", was_blocked);
995 GST_OBJECT_UNLOCK (pad);
1002 * gst_pad_set_blocked:
1003 * @pad: the #GstPad to block or unblock
1004 * @blocked: boolean indicating we should block or unblock
1006 * Blocks or unblocks the dataflow on a pad. This function is
1007 * a shortcut for gst_pad_set_blocked_async() with a NULL
1010 * Returns: TRUE if the pad could be blocked. This function can fail
1011 * wrong parameters were passed or the pad was already in the
1017 gst_pad_set_blocked (GstPad * pad, gboolean blocked)
1019 return gst_pad_set_blocked_async (pad, blocked, NULL, NULL);
1023 * gst_pad_is_blocked:
1024 * @pad: the #GstPad to query
1026 * Checks if the pad is blocked or not. This function returns the
1027 * last requested state of the pad. It is not certain that the pad
1028 * is actually blocking at this point (see gst_pad_is_blocking()).
1030 * Returns: TRUE if the pad is blocked.
1035 gst_pad_is_blocked (GstPad * pad)
1037 gboolean result = FALSE;
1039 g_return_val_if_fail (GST_IS_PAD (pad), result);
1041 GST_OBJECT_LOCK (pad);
1042 result = GST_OBJECT_FLAG_IS_SET (pad, GST_PAD_BLOCKED);
1043 GST_OBJECT_UNLOCK (pad);
1049 * gst_pad_is_blocking:
1050 * @pad: the #GstPad to query
1052 * Checks if the pad is blocking or not. This is a guaranteed state
1053 * of whether the pad is actually blocking on a #GstBuffer or a #GstEvent.
1055 * Returns: TRUE if the pad is blocking.
1062 gst_pad_is_blocking (GstPad * pad)
1064 gboolean result = FALSE;
1066 g_return_val_if_fail (GST_IS_PAD (pad), result);
1068 GST_OBJECT_LOCK (pad);
1069 /* the blocking flag is only valid if the pad is not flushing */
1070 result = GST_OBJECT_FLAG_IS_SET (pad, GST_PAD_BLOCKING) &&
1071 !GST_OBJECT_FLAG_IS_SET (pad, GST_PAD_FLUSHING);
1072 GST_OBJECT_UNLOCK (pad);
1078 * gst_pad_set_activate_function:
1080 * @activate: the #GstPadActivateFunction to set.
1082 * Sets the given activate function for @pad. The activate function will
1083 * dispatch to gst_pad_activate_push() or gst_pad_activate_pull() to perform
1084 * the actual activation. Only makes sense to set on sink pads.
1086 * Call this function if your sink pad can start a pull-based task.
1089 gst_pad_set_activate_function (GstPad * pad, GstPadActivateFunction activate)
1091 g_return_if_fail (GST_IS_PAD (pad));
1093 GST_PAD_ACTIVATEFUNC (pad) = activate;
1094 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "activatefunc set to %s",
1095 GST_DEBUG_FUNCPTR_NAME (activate));
1099 * gst_pad_set_activatepull_function:
1101 * @activatepull: the #GstPadActivateModeFunction to set.
1103 * Sets the given activate_pull function for the pad. An activate_pull function
1104 * prepares the element and any upstream connections for pulling. See XXX
1105 * part-activation.txt for details.
1108 gst_pad_set_activatepull_function (GstPad * pad,
1109 GstPadActivateModeFunction activatepull)
1111 g_return_if_fail (GST_IS_PAD (pad));
1113 GST_PAD_ACTIVATEPULLFUNC (pad) = activatepull;
1114 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "activatepullfunc set to %s",
1115 GST_DEBUG_FUNCPTR_NAME (activatepull));
1119 * gst_pad_set_activatepush_function:
1121 * @activatepush: the #GstPadActivateModeFunction to set.
1123 * Sets the given activate_push function for the pad. An activate_push function
1124 * prepares the element for pushing. See XXX part-activation.txt for details.
1127 gst_pad_set_activatepush_function (GstPad * pad,
1128 GstPadActivateModeFunction activatepush)
1130 g_return_if_fail (GST_IS_PAD (pad));
1132 GST_PAD_ACTIVATEPUSHFUNC (pad) = activatepush;
1133 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "activatepushfunc set to %s",
1134 GST_DEBUG_FUNCPTR_NAME (activatepush));
1138 * gst_pad_set_chain_function:
1139 * @pad: a sink #GstPad.
1140 * @chain: the #GstPadChainFunction to set.
1142 * Sets the given chain function for the pad. The chain function is called to
1143 * process a #GstBuffer input buffer. see #GstPadChainFunction for more details.
1146 gst_pad_set_chain_function (GstPad * pad, GstPadChainFunction chain)
1148 g_return_if_fail (GST_IS_PAD (pad));
1149 g_return_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SINK);
1151 GST_PAD_CHAINFUNC (pad) = chain;
1152 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "chainfunc set to %s",
1153 GST_DEBUG_FUNCPTR_NAME (chain));
1157 * gst_pad_set_getrange_function:
1158 * @pad: a source #GstPad.
1159 * @get: the #GstPadGetRangeFunction to set.
1161 * Sets the given getrange function for the pad. The getrange function is called to
1162 * produce a new #GstBuffer to start the processing pipeline. see
1163 * #GstPadGetRangeFunction for a description of the getrange function.
1166 gst_pad_set_getrange_function (GstPad * pad, GstPadGetRangeFunction get)
1168 g_return_if_fail (GST_IS_PAD (pad));
1169 g_return_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SRC);
1171 GST_PAD_GETRANGEFUNC (pad) = get;
1173 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "getrangefunc set to %s",
1174 GST_DEBUG_FUNCPTR_NAME (get));
1178 * gst_pad_set_checkgetrange_function:
1179 * @pad: a source #GstPad.
1180 * @check: the #GstPadCheckGetRangeFunction to set.
1182 * Sets the given checkgetrange function for the pad. Implement this function on
1183 * a pad if you dynamically support getrange based scheduling on the pad.
1186 gst_pad_set_checkgetrange_function (GstPad * pad,
1187 GstPadCheckGetRangeFunction check)
1189 g_return_if_fail (GST_IS_PAD (pad));
1190 g_return_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SRC);
1192 GST_PAD_CHECKGETRANGEFUNC (pad) = check;
1194 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "checkgetrangefunc set to %s",
1195 GST_DEBUG_FUNCPTR_NAME (check));
1199 * gst_pad_set_event_function:
1200 * @pad: a source #GstPad.
1201 * @event: the #GstPadEventFunction to set.
1203 * Sets the given event handler for the pad.
1206 gst_pad_set_event_function (GstPad * pad, GstPadEventFunction event)
1208 g_return_if_fail (GST_IS_PAD (pad));
1210 GST_PAD_EVENTFUNC (pad) = event;
1212 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "eventfunc for set to %s",
1213 GST_DEBUG_FUNCPTR_NAME (event));
1217 * gst_pad_set_query_function:
1218 * @pad: a #GstPad of either direction.
1219 * @query: the #GstPadQueryFunction to set.
1221 * Set the given query function for the pad.
1224 gst_pad_set_query_function (GstPad * pad, GstPadQueryFunction query)
1226 g_return_if_fail (GST_IS_PAD (pad));
1228 GST_PAD_QUERYFUNC (pad) = query;
1230 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "queryfunc set to %s",
1231 GST_DEBUG_FUNCPTR_NAME (query));
1235 * gst_pad_set_query_type_function:
1236 * @pad: a #GstPad of either direction.
1237 * @type_func: the #GstPadQueryTypeFunction to set.
1239 * Set the given query type function for the pad.
1242 gst_pad_set_query_type_function (GstPad * pad,
1243 GstPadQueryTypeFunction type_func)
1245 g_return_if_fail (GST_IS_PAD (pad));
1247 GST_PAD_QUERYTYPEFUNC (pad) = type_func;
1249 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "querytypefunc set to %s",
1250 GST_DEBUG_FUNCPTR_NAME (type_func));
1254 * gst_pad_get_query_types:
1257 * Get an array of supported queries that can be performed
1260 * Returns: a zero-terminated array of #GstQueryType.
1262 const GstQueryType *
1263 gst_pad_get_query_types (GstPad * pad)
1265 GstPadQueryTypeFunction func;
1267 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
1269 if (G_UNLIKELY ((func = GST_PAD_QUERYTYPEFUNC (pad)) == NULL))
1281 gst_pad_get_query_types_dispatcher (GstPad * pad, const GstQueryType ** data)
1283 *data = gst_pad_get_query_types (pad);
1289 * gst_pad_get_query_types_default:
1292 * Invoke the default dispatcher for the query types on
1295 * Returns: an zero-terminated array of #GstQueryType, or NULL if none of the
1296 * internally-linked pads has a query types function.
1298 const GstQueryType *
1299 gst_pad_get_query_types_default (GstPad * pad)
1301 GstQueryType *result = NULL;
1303 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
1305 gst_pad_dispatcher (pad, (GstPadDispatcherFunction)
1306 gst_pad_get_query_types_dispatcher, &result);
1312 * gst_pad_set_internal_link_function:
1313 * @pad: a #GstPad of either direction.
1314 * @intlink: the #GstPadIntLinkFunction to set.
1316 * Sets the given internal link function for the pad.
1319 gst_pad_set_internal_link_function (GstPad * pad, GstPadIntLinkFunction intlink)
1321 g_return_if_fail (GST_IS_PAD (pad));
1323 GST_PAD_INTLINKFUNC (pad) = intlink;
1324 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "internal link set to %s",
1325 GST_DEBUG_FUNCPTR_NAME (intlink));
1329 * gst_pad_set_link_function:
1331 * @link: the #GstPadLinkFunction to set.
1333 * Sets the given link function for the pad. It will be called when
1334 * the pad is linked with another pad.
1336 * The return value #GST_PAD_LINK_OK should be used when the connection can be
1339 * The return value #GST_PAD_LINK_REFUSED should be used when the connection
1340 * cannot be made for some reason.
1342 * If @link is installed on a source pad, it should call the #GstPadLinkFunction
1343 * of the peer sink pad, if present.
1346 gst_pad_set_link_function (GstPad * pad, GstPadLinkFunction link)
1348 g_return_if_fail (GST_IS_PAD (pad));
1350 GST_PAD_LINKFUNC (pad) = link;
1351 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "linkfunc set to %s",
1352 GST_DEBUG_FUNCPTR_NAME (link));
1356 * gst_pad_set_unlink_function:
1358 * @unlink: the #GstPadUnlinkFunction to set.
1360 * Sets the given unlink function for the pad. It will be called
1361 * when the pad is unlinked.
1364 gst_pad_set_unlink_function (GstPad * pad, GstPadUnlinkFunction unlink)
1366 g_return_if_fail (GST_IS_PAD (pad));
1368 GST_PAD_UNLINKFUNC (pad) = unlink;
1369 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "unlinkfunc set to %s",
1370 GST_DEBUG_FUNCPTR_NAME (unlink));
1374 * gst_pad_set_getcaps_function:
1376 * @getcaps: the #GstPadGetCapsFunction to set.
1378 * Sets the given getcaps function for the pad. @getcaps should return the
1379 * allowable caps for a pad in the context of the element's state, its link to
1380 * other elements, and the devices or files it has opened. These caps must be a
1381 * subset of the pad template caps. In the NULL state with no links, @getcaps
1382 * should ideally return the same caps as the pad template. In rare
1383 * circumstances, an object property can affect the caps returned by @getcaps,
1384 * but this is discouraged.
1386 * You do not need to call this function if @pad's allowed caps are always the
1387 * same as the pad template caps. This can only be true if the padtemplate
1388 * has fixed simple caps.
1390 * For most filters, the caps returned by @getcaps is directly affected by the
1391 * allowed caps on other pads. For demuxers and decoders, the caps returned by
1392 * the srcpad's getcaps function is directly related to the stream data. Again,
1393 * @getcaps should return the most specific caps it reasonably can, since this
1394 * helps with autoplugging.
1396 * Note that the return value from @getcaps is owned by the caller, so the caller
1397 * should unref the caps after usage.
1400 gst_pad_set_getcaps_function (GstPad * pad, GstPadGetCapsFunction getcaps)
1402 g_return_if_fail (GST_IS_PAD (pad));
1404 GST_PAD_GETCAPSFUNC (pad) = getcaps;
1405 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "getcapsfunc set to %s",
1406 GST_DEBUG_FUNCPTR_NAME (getcaps));
1410 * gst_pad_set_acceptcaps_function:
1412 * @acceptcaps: the #GstPadAcceptCapsFunction to set.
1414 * Sets the given acceptcaps function for the pad. The acceptcaps function
1415 * will be called to check if the pad can accept the given caps. Setting the
1416 * acceptcaps function to NULL restores the default behaviour of allowing
1417 * any caps that matches the caps from gst_pad_get_caps.
1420 gst_pad_set_acceptcaps_function (GstPad * pad,
1421 GstPadAcceptCapsFunction acceptcaps)
1423 g_return_if_fail (GST_IS_PAD (pad));
1425 GST_PAD_ACCEPTCAPSFUNC (pad) = acceptcaps;
1426 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "acceptcapsfunc set to %s",
1427 GST_DEBUG_FUNCPTR_NAME (acceptcaps));
1431 * gst_pad_set_fixatecaps_function:
1433 * @fixatecaps: the #GstPadFixateCapsFunction to set.
1435 * Sets the given fixatecaps function for the pad. The fixatecaps function
1436 * will be called whenever the default values for a GstCaps needs to be
1440 gst_pad_set_fixatecaps_function (GstPad * pad,
1441 GstPadFixateCapsFunction fixatecaps)
1443 g_return_if_fail (GST_IS_PAD (pad));
1445 GST_PAD_FIXATECAPSFUNC (pad) = fixatecaps;
1446 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "fixatecapsfunc set to %s",
1447 GST_DEBUG_FUNCPTR_NAME (fixatecaps));
1451 * gst_pad_set_setcaps_function:
1453 * @setcaps: the #GstPadSetCapsFunction to set.
1455 * Sets the given setcaps function for the pad. The setcaps function
1456 * will be called whenever a buffer with a new media type is pushed or
1457 * pulled from the pad. The pad/element needs to update its internal
1458 * structures to process the new media type. If this new type is not
1459 * acceptable, the setcaps function should return FALSE.
1462 gst_pad_set_setcaps_function (GstPad * pad, GstPadSetCapsFunction setcaps)
1464 g_return_if_fail (GST_IS_PAD (pad));
1466 GST_PAD_SETCAPSFUNC (pad) = setcaps;
1467 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "setcapsfunc set to %s",
1468 GST_DEBUG_FUNCPTR_NAME (setcaps));
1472 * gst_pad_set_bufferalloc_function:
1473 * @pad: a sink #GstPad.
1474 * @bufalloc: the #GstPadBufferAllocFunction to set.
1476 * Sets the given bufferalloc function for the pad. Note that the
1477 * bufferalloc function can only be set on sinkpads.
1480 gst_pad_set_bufferalloc_function (GstPad * pad,
1481 GstPadBufferAllocFunction bufalloc)
1483 g_return_if_fail (GST_IS_PAD (pad));
1484 g_return_if_fail (GST_PAD_IS_SINK (pad));
1486 GST_PAD_BUFFERALLOCFUNC (pad) = bufalloc;
1487 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "bufferallocfunc set to %s",
1488 GST_DEBUG_FUNCPTR_NAME (bufalloc));
1493 * @srcpad: the source #GstPad to unlink.
1494 * @sinkpad: the sink #GstPad to unlink.
1496 * Unlinks the source pad from the sink pad. Will emit the "unlinked" signal on
1499 * Returns: TRUE if the pads were unlinked. This function returns FALSE if
1500 * the pads were not linked together.
1505 gst_pad_unlink (GstPad * srcpad, GstPad * sinkpad)
1507 g_return_val_if_fail (GST_IS_PAD (srcpad), FALSE);
1508 g_return_val_if_fail (GST_IS_PAD (sinkpad), FALSE);
1510 GST_CAT_INFO (GST_CAT_ELEMENT_PADS, "unlinking %s:%s(%p) and %s:%s(%p)",
1511 GST_DEBUG_PAD_NAME (srcpad), srcpad,
1512 GST_DEBUG_PAD_NAME (sinkpad), sinkpad);
1514 GST_OBJECT_LOCK (srcpad);
1516 if (G_UNLIKELY (GST_PAD_DIRECTION (srcpad) != GST_PAD_SRC))
1519 GST_OBJECT_LOCK (sinkpad);
1521 if (G_UNLIKELY (GST_PAD_DIRECTION (sinkpad) != GST_PAD_SINK))
1524 if (G_UNLIKELY (GST_PAD_PEER (srcpad) != sinkpad))
1525 goto not_linked_together;
1527 if (GST_PAD_UNLINKFUNC (srcpad)) {
1528 GST_PAD_UNLINKFUNC (srcpad) (srcpad);
1530 if (GST_PAD_UNLINKFUNC (sinkpad)) {
1531 GST_PAD_UNLINKFUNC (sinkpad) (sinkpad);
1534 /* first clear peers */
1535 GST_PAD_PEER (srcpad) = NULL;
1536 GST_PAD_PEER (sinkpad) = NULL;
1538 GST_OBJECT_UNLOCK (sinkpad);
1539 GST_OBJECT_UNLOCK (srcpad);
1541 /* fire off a signal to each of the pads telling them
1542 * that they've been unlinked */
1543 g_signal_emit (G_OBJECT (srcpad), gst_pad_signals[PAD_UNLINKED], 0, sinkpad);
1544 g_signal_emit (G_OBJECT (sinkpad), gst_pad_signals[PAD_UNLINKED], 0, srcpad);
1546 GST_CAT_INFO (GST_CAT_ELEMENT_PADS, "unlinked %s:%s and %s:%s",
1547 GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (sinkpad));
1553 g_critical ("pad %s is not a source pad", GST_PAD_NAME (srcpad));
1554 GST_OBJECT_UNLOCK (srcpad);
1559 g_critical ("pad %s is not a sink pad", GST_PAD_NAME (sinkpad));
1560 GST_OBJECT_UNLOCK (sinkpad);
1561 GST_OBJECT_UNLOCK (srcpad);
1564 not_linked_together:
1566 /* we do not emit a warning in this case because unlinking cannot
1567 * be made MT safe.*/
1568 GST_OBJECT_UNLOCK (sinkpad);
1569 GST_OBJECT_UNLOCK (srcpad);
1575 * gst_pad_is_linked:
1576 * @pad: pad to check
1578 * Checks if a @pad is linked to another pad or not.
1580 * Returns: TRUE if the pad is linked, FALSE otherwise.
1585 gst_pad_is_linked (GstPad * pad)
1589 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
1591 GST_OBJECT_LOCK (pad);
1592 result = (GST_PAD_PEER (pad) != NULL);
1593 GST_OBJECT_UNLOCK (pad);
1598 /* get the caps from both pads and see if the intersection
1601 * This function should be called with the pad LOCK on both
1605 gst_pad_link_check_compatible_unlocked (GstPad * src, GstPad * sink)
1611 srccaps = gst_pad_get_caps_unlocked (src);
1612 sinkcaps = gst_pad_get_caps_unlocked (sink);
1614 GST_CAT_DEBUG (GST_CAT_CAPS, "src caps %" GST_PTR_FORMAT, srccaps);
1615 GST_CAT_DEBUG (GST_CAT_CAPS, "sink caps %" GST_PTR_FORMAT, sinkcaps);
1617 /* if we have caps on both pads we can check the intersection. If one
1618 * of the caps is NULL, we return TRUE. */
1619 if (srccaps == NULL || sinkcaps == NULL)
1622 icaps = gst_caps_intersect (srccaps, sinkcaps);
1623 gst_caps_unref (srccaps);
1624 gst_caps_unref (sinkcaps);
1629 GST_CAT_DEBUG (GST_CAT_CAPS,
1630 "intersection caps %p %" GST_PTR_FORMAT, icaps, icaps);
1632 if (gst_caps_is_empty (icaps))
1635 gst_caps_unref (icaps);
1640 /* incompatible cases */
1643 GST_CAT_DEBUG (GST_CAT_CAPS, "intersection gave NULL");
1648 GST_CAT_DEBUG (GST_CAT_CAPS, "intersection is EMPTY");
1649 gst_caps_unref (icaps);
1654 /* check if the grandparents of both pads are the same.
1655 * This check is required so that we don't try to link
1656 * pads from elements in different bins without ghostpads.
1658 * The LOCK should be held on both pads
1661 gst_pad_link_check_hierarchy (GstPad * src, GstPad * sink)
1663 GstObject *psrc, *psink;
1665 psrc = GST_OBJECT_PARENT (src);
1666 psink = GST_OBJECT_PARENT (sink);
1668 /* if one of the pads has no parent, we allow the link */
1669 if (G_UNLIKELY (psrc == NULL || psink == NULL))
1672 /* if the parents are the same, we have a loop */
1673 if (G_UNLIKELY (psrc == psink))
1676 /* if they both have a parent, we check the grandparents. We can not lock
1677 * the parent because we hold on the child (pad) and the locking order is
1678 * parent >> child. */
1679 psrc = GST_OBJECT_PARENT (psrc);
1680 psink = GST_OBJECT_PARENT (psink);
1682 /* if they have grandparents but they are not the same */
1683 if (G_UNLIKELY (psrc != psink))
1684 goto wrong_grandparents;
1691 GST_CAT_DEBUG (GST_CAT_CAPS,
1692 "one of the pads has no parent %" GST_PTR_FORMAT " and %"
1693 GST_PTR_FORMAT, psrc, psink);
1698 GST_CAT_DEBUG (GST_CAT_CAPS, "pads have same parent %" GST_PTR_FORMAT,
1704 GST_CAT_DEBUG (GST_CAT_CAPS,
1705 "pads have different grandparents %" GST_PTR_FORMAT " and %"
1706 GST_PTR_FORMAT, psrc, psink);
1711 /* FIXME leftover from an attempt at refactoring... */
1712 /* call with the two pads unlocked, when this function returns GST_PAD_LINK_OK,
1713 * the two pads will be locked in the srcpad, sinkpad order. */
1714 static GstPadLinkReturn
1715 gst_pad_link_prepare (GstPad * srcpad, GstPad * sinkpad)
1717 /* generic checks */
1718 g_return_val_if_fail (GST_IS_PAD (srcpad), GST_PAD_LINK_REFUSED);
1719 g_return_val_if_fail (GST_IS_PAD (sinkpad), GST_PAD_LINK_REFUSED);
1721 GST_CAT_INFO (GST_CAT_PADS, "trying to link %s:%s and %s:%s",
1722 GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (sinkpad));
1724 GST_OBJECT_LOCK (srcpad);
1726 if (G_UNLIKELY (GST_PAD_DIRECTION (srcpad) != GST_PAD_SRC))
1729 if (G_UNLIKELY (GST_PAD_PEER (srcpad) != NULL))
1730 goto src_was_linked;
1732 GST_OBJECT_LOCK (sinkpad);
1734 if (G_UNLIKELY (GST_PAD_DIRECTION (sinkpad) != GST_PAD_SINK))
1737 if (G_UNLIKELY (GST_PAD_PEER (sinkpad) != NULL))
1738 goto sink_was_linked;
1740 /* check hierarchy, pads can only be linked if the grandparents
1742 if (!gst_pad_link_check_hierarchy (srcpad, sinkpad))
1743 goto wrong_hierarchy;
1745 /* check pad caps for non-empty intersection */
1746 if (!gst_pad_link_check_compatible_unlocked (srcpad, sinkpad))
1749 /* FIXME check pad scheduling for non-empty intersection */
1751 return GST_PAD_LINK_OK;
1755 g_critical ("pad %s is not a source pad", GST_PAD_NAME (srcpad));
1756 GST_OBJECT_UNLOCK (srcpad);
1757 return GST_PAD_LINK_WRONG_DIRECTION;
1761 GST_CAT_INFO (GST_CAT_PADS, "src %s:%s was already linked to %s:%s",
1762 GST_DEBUG_PAD_NAME (srcpad),
1763 GST_DEBUG_PAD_NAME (GST_PAD_PEER (srcpad)));
1764 /* we do not emit a warning in this case because unlinking cannot
1765 * be made MT safe.*/
1766 GST_OBJECT_UNLOCK (srcpad);
1767 return GST_PAD_LINK_WAS_LINKED;
1771 g_critical ("pad %s is not a sink pad", GST_PAD_NAME (sinkpad));
1772 GST_OBJECT_UNLOCK (sinkpad);
1773 GST_OBJECT_UNLOCK (srcpad);
1774 return GST_PAD_LINK_WRONG_DIRECTION;
1778 GST_CAT_INFO (GST_CAT_PADS, "sink %s:%s was already linked to %s:%s",
1779 GST_DEBUG_PAD_NAME (sinkpad),
1780 GST_DEBUG_PAD_NAME (GST_PAD_PEER (sinkpad)));
1781 /* we do not emit a warning in this case because unlinking cannot
1782 * be made MT safe.*/
1783 GST_OBJECT_UNLOCK (sinkpad);
1784 GST_OBJECT_UNLOCK (srcpad);
1785 return GST_PAD_LINK_WAS_LINKED;
1789 GST_CAT_INFO (GST_CAT_PADS, "pads have wrong hierarchy");
1790 GST_OBJECT_UNLOCK (sinkpad);
1791 GST_OBJECT_UNLOCK (srcpad);
1792 return GST_PAD_LINK_WRONG_HIERARCHY;
1796 GST_CAT_INFO (GST_CAT_PADS, "caps are incompatible");
1797 GST_OBJECT_UNLOCK (sinkpad);
1798 GST_OBJECT_UNLOCK (srcpad);
1799 return GST_PAD_LINK_NOFORMAT;
1805 * @srcpad: the source #GstPad to link.
1806 * @sinkpad: the sink #GstPad to link.
1808 * Links the source pad and the sink pad.
1810 * Returns: A result code indicating if the connection worked or
1816 gst_pad_link (GstPad * srcpad, GstPad * sinkpad)
1818 GstPadLinkReturn result;
1820 /* prepare will also lock the two pads */
1821 result = gst_pad_link_prepare (srcpad, sinkpad);
1823 if (result != GST_PAD_LINK_OK)
1824 goto prepare_failed;
1826 /* must set peers before calling the link function */
1827 GST_PAD_PEER (srcpad) = sinkpad;
1828 GST_PAD_PEER (sinkpad) = srcpad;
1830 GST_OBJECT_UNLOCK (sinkpad);
1831 GST_OBJECT_UNLOCK (srcpad);
1833 /* FIXME released the locks here, concurrent thread might link
1834 * something else. */
1835 if (GST_PAD_LINKFUNC (srcpad)) {
1836 /* this one will call the peer link function */
1837 result = GST_PAD_LINKFUNC (srcpad) (srcpad, sinkpad);
1838 } else if (GST_PAD_LINKFUNC (sinkpad)) {
1839 /* if no source link function, we need to call the sink link
1840 * function ourselves. */
1841 result = GST_PAD_LINKFUNC (sinkpad) (sinkpad, srcpad);
1843 result = GST_PAD_LINK_OK;
1846 GST_OBJECT_LOCK (srcpad);
1847 GST_OBJECT_LOCK (sinkpad);
1849 if (result == GST_PAD_LINK_OK) {
1850 GST_OBJECT_UNLOCK (sinkpad);
1851 GST_OBJECT_UNLOCK (srcpad);
1853 /* fire off a signal to each of the pads telling them
1854 * that they've been linked */
1855 g_signal_emit (G_OBJECT (srcpad), gst_pad_signals[PAD_LINKED], 0, sinkpad);
1856 g_signal_emit (G_OBJECT (sinkpad), gst_pad_signals[PAD_LINKED], 0, srcpad);
1858 GST_CAT_INFO (GST_CAT_PADS, "linked %s:%s and %s:%s, successful",
1859 GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (sinkpad));
1861 GST_CAT_INFO (GST_CAT_PADS, "link between %s:%s and %s:%s failed",
1862 GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (sinkpad));
1864 GST_PAD_PEER (srcpad) = NULL;
1865 GST_PAD_PEER (sinkpad) = NULL;
1867 GST_OBJECT_UNLOCK (sinkpad);
1868 GST_OBJECT_UNLOCK (srcpad);
1879 gst_pad_set_pad_template (GstPad * pad, GstPadTemplate * templ)
1881 GstPadTemplate **template_p;
1883 /* this function would need checks if it weren't static */
1885 GST_OBJECT_LOCK (pad);
1886 template_p = &pad->padtemplate;
1887 gst_object_replace ((GstObject **) template_p, (GstObject *) templ);
1888 GST_OBJECT_UNLOCK (pad);
1891 gst_pad_template_pad_created (templ, pad);
1895 * gst_pad_get_pad_template:
1898 * Gets the template for @pad.
1900 * Returns: the #GstPadTemplate from which this pad was instantiated, or %NULL
1901 * if this pad has no template.
1903 * FIXME: currently returns an unrefcounted padtemplate.
1906 gst_pad_get_pad_template (GstPad * pad)
1908 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
1910 return GST_PAD_PAD_TEMPLATE (pad);
1914 /* should be called with the pad LOCK held */
1915 /* refs the caps, so caller is responsible for getting it unreffed */
1917 gst_pad_get_caps_unlocked (GstPad * pad)
1919 GstCaps *result = NULL;
1921 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "get pad caps");
1923 if (GST_PAD_GETCAPSFUNC (pad)) {
1924 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
1925 "dispatching to pad getcaps function");
1927 GST_OBJECT_FLAG_SET (pad, GST_PAD_IN_GETCAPS);
1928 GST_OBJECT_UNLOCK (pad);
1929 result = GST_PAD_GETCAPSFUNC (pad) (pad);
1930 GST_OBJECT_LOCK (pad);
1931 GST_OBJECT_FLAG_UNSET (pad, GST_PAD_IN_GETCAPS);
1933 if (result == NULL) {
1934 g_critical ("pad %s:%s returned NULL caps from getcaps function",
1935 GST_DEBUG_PAD_NAME (pad));
1937 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
1938 "pad getcaps returned %" GST_PTR_FORMAT, result);
1939 #ifndef G_DISABLE_ASSERT
1940 /* check that the returned caps are a real subset of the template caps */
1941 if (GST_PAD_PAD_TEMPLATE (pad)) {
1942 const GstCaps *templ_caps =
1943 GST_PAD_TEMPLATE_CAPS (GST_PAD_PAD_TEMPLATE (pad));
1944 if (!gst_caps_is_subset (result, templ_caps)) {
1947 GST_CAT_ERROR_OBJECT (GST_CAT_CAPS, pad,
1948 "pad returned caps %" GST_PTR_FORMAT
1949 " which are not a real subset of its template caps %"
1950 GST_PTR_FORMAT, result, templ_caps);
1952 ("pad %s:%s returned caps which are not a real "
1953 "subset of its template caps", GST_DEBUG_PAD_NAME (pad));
1954 temp = gst_caps_intersect (templ_caps, result);
1955 gst_caps_unref (result);
1963 if (GST_PAD_PAD_TEMPLATE (pad)) {
1964 GstPadTemplate *templ = GST_PAD_PAD_TEMPLATE (pad);
1966 result = GST_PAD_TEMPLATE_CAPS (templ);
1967 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
1968 "using pad template %p with caps %p %" GST_PTR_FORMAT, templ, result,
1971 result = gst_caps_ref (result);
1974 if (GST_PAD_CAPS (pad)) {
1975 result = GST_PAD_CAPS (pad);
1977 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
1978 "using pad caps %p %" GST_PTR_FORMAT, result, result);
1980 result = gst_caps_ref (result);
1984 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "pad has no caps");
1985 result = gst_caps_new_empty ();
1993 * @pad: a #GstPad to get the capabilities of.
1995 * Gets the capabilities this pad can produce or consume.
1996 * Note that this method doesn't necessarily return the caps set by
1997 * gst_pad_set_caps() - use #GST_PAD_CAPS for that instead.
1998 * gst_pad_get_caps returns all possible caps a pad can operate with, using
1999 * the pad's get_caps function;
2000 * this returns the pad template caps if not explicitly set.
2002 * Returns: a newly allocated copy of the #GstCaps of this pad.
2007 gst_pad_get_caps (GstPad * pad)
2009 GstCaps *result = NULL;
2011 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2013 GST_OBJECT_LOCK (pad);
2015 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "get pad caps");
2017 result = gst_pad_get_caps_unlocked (pad);
2018 GST_OBJECT_UNLOCK (pad);
2024 * gst_pad_peer_get_caps:
2025 * @pad: a #GstPad to get the peer capabilities of.
2027 * Gets the capabilities of the peer connected to this pad.
2029 * Returns: the #GstCaps of the peer pad. This function returns a new caps, so use
2030 * gst_caps_unref to get rid of it. this function returns NULL if there is no
2034 gst_pad_peer_get_caps (GstPad * pad)
2037 GstCaps *result = NULL;
2039 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2041 GST_OBJECT_LOCK (pad);
2043 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "get peer caps");
2045 peerpad = GST_PAD_PEER (pad);
2046 if (G_UNLIKELY (peerpad == NULL))
2049 gst_object_ref (peerpad);
2050 GST_OBJECT_UNLOCK (pad);
2052 result = gst_pad_get_caps (peerpad);
2054 gst_object_unref (peerpad);
2060 GST_OBJECT_UNLOCK (pad);
2066 fixate_value (GValue * dest, const GValue * src)
2068 if (G_VALUE_TYPE (src) == GST_TYPE_INT_RANGE) {
2069 g_value_init (dest, G_TYPE_INT);
2070 g_value_set_int (dest, gst_value_get_int_range_min (src));
2071 } else if (G_VALUE_TYPE (src) == GST_TYPE_DOUBLE_RANGE) {
2072 g_value_init (dest, G_TYPE_DOUBLE);
2073 g_value_set_double (dest, gst_value_get_double_range_min (src));
2074 } else if (G_VALUE_TYPE (src) == GST_TYPE_FRACTION_RANGE) {
2075 gst_value_init_and_copy (dest, gst_value_get_fraction_range_min (src));
2076 } else if (G_VALUE_TYPE (src) == GST_TYPE_LIST) {
2077 GValue temp = { 0 };
2079 gst_value_init_and_copy (&temp, gst_value_list_get_value (src, 0));
2080 if (!fixate_value (dest, &temp))
2081 gst_value_init_and_copy (dest, &temp);
2082 g_value_unset (&temp);
2083 } else if (G_VALUE_TYPE (src) == GST_TYPE_ARRAY) {
2084 gboolean res = FALSE;
2087 g_value_init (dest, GST_TYPE_ARRAY);
2088 for (n = 0; n < gst_value_array_get_size (src); n++) {
2090 const GValue *orig_kid = gst_value_array_get_value (src, n);
2092 if (!fixate_value (&kid, orig_kid))
2093 gst_value_init_and_copy (&kid, orig_kid);
2096 gst_value_array_append_value (dest, &kid);
2097 g_value_unset (&kid);
2101 g_value_unset (dest);
2112 gst_pad_default_fixate (GQuark field_id, const GValue * value, gpointer data)
2114 GstStructure *s = data;
2117 if (fixate_value (&v, value)) {
2118 gst_structure_id_set_value (s, field_id, &v);
2126 * gst_pad_fixate_caps:
2127 * @pad: a #GstPad to fixate
2128 * @caps: the #GstCaps to fixate
2130 * Fixate a caps on the given pad. Modifies the caps in place, so you should
2131 * make sure that the caps are actually writable (see gst_caps_make_writable()).
2134 gst_pad_fixate_caps (GstPad * pad, GstCaps * caps)
2136 GstPadFixateCapsFunction fixatefunc;
2139 g_return_if_fail (GST_IS_PAD (pad));
2140 g_return_if_fail (caps != NULL);
2142 if (gst_caps_is_fixed (caps))
2145 fixatefunc = GST_PAD_FIXATECAPSFUNC (pad);
2147 fixatefunc (pad, caps);
2150 /* default fixation */
2151 for (n = 0; n < gst_caps_get_size (caps); n++) {
2152 GstStructure *s = gst_caps_get_structure (caps, n);
2154 gst_structure_foreach (s, gst_pad_default_fixate, s);
2158 /* Default accept caps implementation just checks against
2159 * against the allowed caps for the pad */
2161 gst_pad_acceptcaps_default (GstPad * pad, GstCaps * caps)
2163 /* get the caps and see if it intersects to something
2167 gboolean result = FALSE;
2169 allowed = gst_pad_get_caps (pad);
2171 goto nothing_allowed;
2173 intersect = gst_caps_intersect (allowed, caps);
2175 result = !gst_caps_is_empty (intersect);
2177 GST_DEBUG_OBJECT (pad, "intersection gave empty caps");
2179 gst_caps_unref (allowed);
2180 gst_caps_unref (intersect);
2187 GST_DEBUG_OBJECT (pad, "no caps allowed on the pad");
2193 * gst_pad_accept_caps:
2194 * @pad: a #GstPad to check
2195 * @caps: a #GstCaps to check on the pad
2197 * Check if the given pad accepts the caps.
2199 * Returns: TRUE if the pad can accept the caps.
2202 gst_pad_accept_caps (GstPad * pad, GstCaps * caps)
2205 GstPadAcceptCapsFunction acceptfunc;
2206 GstCaps *existing = NULL;
2208 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2210 /* any pad can be unnegotiated */
2214 /* lock for checking the existing caps */
2215 GST_OBJECT_LOCK (pad);
2216 acceptfunc = GST_PAD_ACCEPTCAPSFUNC (pad);
2217 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "accept caps of %p", caps);
2218 /* The current caps on a pad are trivially acceptable */
2219 if (G_LIKELY ((existing = GST_PAD_CAPS (pad)))) {
2220 if (caps == existing || gst_caps_is_equal (caps, existing))
2223 GST_OBJECT_UNLOCK (pad);
2225 if (G_LIKELY (acceptfunc)) {
2226 /* we can call the function */
2227 result = acceptfunc (pad, caps);
2228 GST_DEBUG_OBJECT (pad, "acceptfunc returned %d", result);
2230 /* Only null if the element explicitly unset it */
2231 result = gst_pad_acceptcaps_default (pad, caps);
2232 GST_DEBUG_OBJECT (pad, "default acceptcaps returned %d", result);
2238 GST_DEBUG_OBJECT (pad, "pad had same caps");
2239 GST_OBJECT_UNLOCK (pad);
2245 * gst_pad_peer_accept_caps:
2246 * @pad: a #GstPad to check the peer of
2247 * @caps: a #GstCaps to check on the pad
2249 * Check if the peer of @pad accepts @caps. If @pad has no peer, this function
2252 * Returns: TRUE if the peer of @pad can accept the caps or @pad has no peer.
2255 gst_pad_peer_accept_caps (GstPad * pad, GstCaps * caps)
2260 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2262 GST_OBJECT_LOCK (pad);
2264 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "peer accept caps of (%p)", pad);
2266 peerpad = GST_PAD_PEER (pad);
2267 if (G_UNLIKELY (peerpad == NULL))
2270 result = gst_pad_accept_caps (peerpad, caps);
2271 GST_OBJECT_UNLOCK (pad);
2277 GST_OBJECT_UNLOCK (pad);
2284 * @pad: a #GstPad to set the capabilities of.
2285 * @caps: a #GstCaps to set.
2287 * Sets the capabilities of this pad. The caps must be fixed. Any previous
2288 * caps on the pad will be unreffed. This function refs the caps so you should
2289 * unref if as soon as you don't need it anymore.
2290 * It is possible to set NULL caps, which will make the pad unnegotiated
2293 * Returns: TRUE if the caps could be set. FALSE if the caps were not fixed
2294 * or bad parameters were provided to this function.
2299 gst_pad_set_caps (GstPad * pad, GstCaps * caps)
2301 GstPadSetCapsFunction setcaps;
2304 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2305 g_return_val_if_fail (caps == NULL || gst_caps_is_fixed (caps), FALSE);
2307 GST_OBJECT_LOCK (pad);
2308 existing = GST_PAD_CAPS (pad);
2309 if (existing == caps)
2312 if (gst_caps_is_equal (caps, existing))
2313 goto setting_same_caps;
2315 setcaps = GST_PAD_SETCAPSFUNC (pad);
2317 /* call setcaps function to configure the pad only if the
2318 * caps is not NULL */
2319 if (setcaps != NULL && caps) {
2320 if (!GST_PAD_IS_IN_SETCAPS (pad)) {
2321 GST_OBJECT_FLAG_SET (pad, GST_PAD_IN_SETCAPS);
2322 GST_OBJECT_UNLOCK (pad);
2323 if (!setcaps (pad, caps))
2325 GST_OBJECT_LOCK (pad);
2326 GST_OBJECT_FLAG_UNSET (pad, GST_PAD_IN_SETCAPS);
2328 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "pad was dispatching");
2332 gst_caps_replace (&GST_PAD_CAPS (pad), caps);
2333 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "caps %" GST_PTR_FORMAT, caps);
2334 GST_OBJECT_UNLOCK (pad);
2336 g_object_notify (G_OBJECT (pad), "caps");
2342 GST_OBJECT_UNLOCK (pad);
2347 gst_caps_replace (&GST_PAD_CAPS (pad), caps);
2348 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
2349 "caps %" GST_PTR_FORMAT " same as existing, updating ptr only", caps);
2350 GST_OBJECT_UNLOCK (pad);
2357 GST_OBJECT_LOCK (pad);
2358 GST_OBJECT_FLAG_UNSET (pad, GST_PAD_IN_SETCAPS);
2359 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
2360 "caps %" GST_PTR_FORMAT " could not be set", caps);
2361 GST_OBJECT_UNLOCK (pad);
2368 gst_pad_configure_sink (GstPad * pad, GstCaps * caps)
2370 GstPadSetCapsFunction setcaps;
2373 setcaps = GST_PAD_SETCAPSFUNC (pad);
2375 /* See if pad accepts the caps - only needed if
2376 * no setcaps function */
2377 if (setcaps == NULL)
2378 if (!gst_pad_accept_caps (pad, caps))
2381 /* set caps on pad if call succeeds */
2382 res = gst_pad_set_caps (pad, caps);
2383 /* no need to unref the caps here, set_caps takes a ref and
2384 * our ref goes away when we leave this function. */
2390 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
2391 "caps %" GST_PTR_FORMAT " not accepted", caps);
2396 /* returns TRUE if the src pad could be configured to accept the given caps */
2398 gst_pad_configure_src (GstPad * pad, GstCaps * caps, gboolean dosetcaps)
2400 GstPadSetCapsFunction setcaps;
2403 setcaps = GST_PAD_SETCAPSFUNC (pad);
2405 /* See if pad accepts the caps - only needed if
2406 * no setcaps function */
2407 if (setcaps == NULL)
2408 if (!gst_pad_accept_caps (pad, caps))
2412 res = gst_pad_set_caps (pad, caps);
2420 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
2421 "caps %" GST_PTR_FORMAT " not accepted", caps);
2427 * gst_pad_get_pad_template_caps:
2428 * @pad: a #GstPad to get the template capabilities from.
2430 * Gets the capabilities for @pad's template.
2432 * Returns: the #GstCaps of this pad template. If you intend to keep a reference
2433 * on the caps, make a copy (see gst_caps_copy ()).
2436 gst_pad_get_pad_template_caps (GstPad * pad)
2438 static GstStaticCaps anycaps = GST_STATIC_CAPS ("ANY");
2440 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2442 if (GST_PAD_PAD_TEMPLATE (pad))
2443 return GST_PAD_TEMPLATE_CAPS (GST_PAD_PAD_TEMPLATE (pad));
2445 return gst_static_caps_get (&anycaps);
2451 * @pad: a #GstPad to get the peer of.
2453 * Gets the peer of @pad. This function refs the peer pad so
2454 * you need to unref it after use.
2456 * Returns: the peer #GstPad. Unref after usage.
2461 gst_pad_get_peer (GstPad * pad)
2465 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2467 GST_OBJECT_LOCK (pad);
2468 result = GST_PAD_PEER (pad);
2470 gst_object_ref (result);
2471 GST_OBJECT_UNLOCK (pad);
2477 * gst_pad_get_allowed_caps:
2478 * @srcpad: a #GstPad, it must a a source pad.
2480 * Gets the capabilities of the allowed media types that can flow through
2481 * @srcpad and its peer. The pad must be a source pad.
2482 * The caller must free the resulting caps.
2484 * Returns: the allowed #GstCaps of the pad link. Free the caps when
2485 * you no longer need it. This function returns NULL when the @srcpad has no
2491 gst_pad_get_allowed_caps (GstPad * srcpad)
2498 g_return_val_if_fail (GST_IS_PAD (srcpad), NULL);
2499 g_return_val_if_fail (GST_PAD_IS_SRC (srcpad), NULL);
2501 GST_OBJECT_LOCK (srcpad);
2503 peer = GST_PAD_PEER (srcpad);
2504 if (G_UNLIKELY (peer == NULL))
2507 GST_CAT_DEBUG_OBJECT (GST_CAT_PROPERTIES, srcpad, "getting allowed caps");
2509 gst_object_ref (peer);
2510 GST_OBJECT_UNLOCK (srcpad);
2511 mycaps = gst_pad_get_caps (srcpad);
2513 peercaps = gst_pad_get_caps (peer);
2514 gst_object_unref (peer);
2516 caps = gst_caps_intersect (mycaps, peercaps);
2517 gst_caps_unref (peercaps);
2518 gst_caps_unref (mycaps);
2520 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, srcpad, "allowed caps %" GST_PTR_FORMAT,
2527 GST_CAT_DEBUG_OBJECT (GST_CAT_PROPERTIES, srcpad, "no peer");
2528 GST_OBJECT_UNLOCK (srcpad);
2535 * gst_pad_get_negotiated_caps:
2538 * Gets the capabilities of the media type that currently flows through @pad
2541 * This function can be used on both src and sinkpads. Note that srcpads are
2542 * always negotiated before sinkpads so it is possible that the negotiated caps
2543 * on the srcpad do not match the negotiated caps of the peer.
2545 * Returns: the negotiated #GstCaps of the pad link. Free the caps when
2546 * you no longer need it. This function returns NULL when the @pad has no
2547 * peer or is not negotiated yet.
2552 gst_pad_get_negotiated_caps (GstPad * pad)
2557 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2559 GST_OBJECT_LOCK (pad);
2561 if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
2564 GST_CAT_DEBUG_OBJECT (GST_CAT_PROPERTIES, pad, "getting negotiated caps");
2566 caps = GST_PAD_CAPS (pad);
2568 gst_caps_ref (caps);
2569 GST_OBJECT_UNLOCK (pad);
2571 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "negotiated caps %" GST_PTR_FORMAT,
2578 GST_CAT_DEBUG_OBJECT (GST_CAT_PROPERTIES, pad, "no peer");
2579 GST_OBJECT_UNLOCK (pad);
2585 /* calls the buffer_alloc function on the given pad */
2586 static GstFlowReturn
2587 gst_pad_buffer_alloc_unchecked (GstPad * pad, guint64 offset, gint size,
2588 GstCaps * caps, GstBuffer ** buf)
2591 GstPadBufferAllocFunction bufferallocfunc;
2593 GST_OBJECT_LOCK (pad);
2594 /* when the pad is flushing we cannot give a buffer */
2595 if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad)))
2598 bufferallocfunc = pad->bufferallocfunc;
2600 if (offset == GST_BUFFER_OFFSET_NONE) {
2601 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
2602 "calling bufferallocfunc &%s (@%p) for size %d offset NONE",
2603 GST_DEBUG_FUNCPTR_NAME (bufferallocfunc), bufferallocfunc, size);
2605 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
2606 "calling bufferallocfunc &%s (@%p) of for size %d offset %"
2607 G_GUINT64_FORMAT, GST_DEBUG_FUNCPTR_NAME (bufferallocfunc),
2608 bufferallocfunc, size, offset);
2610 GST_OBJECT_UNLOCK (pad);
2612 /* G_LIKELY for now since most elements don't implement a buffer alloc
2613 * function and there is no default alloc proxy function as this is usually
2615 if (G_LIKELY (bufferallocfunc == NULL))
2618 ret = bufferallocfunc (pad, offset, size, caps, buf);
2619 if (G_UNLIKELY (ret != GST_FLOW_OK))
2621 /* no error, but NULL buffer means fallback to the default */
2622 if (G_UNLIKELY (*buf == NULL))
2625 /* If the buffer alloc function didn't set up the caps like it should,
2627 if (G_UNLIKELY (caps && (GST_BUFFER_CAPS (*buf) == NULL))) {
2628 GST_WARNING_OBJECT (pad,
2629 "Buffer allocation function did not set caps. Setting");
2630 gst_buffer_set_caps (*buf, caps);
2636 /* pad was flushing */
2637 GST_OBJECT_UNLOCK (pad);
2638 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "pad was flushing");
2639 return GST_FLOW_WRONG_STATE;
2643 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
2644 "alloc function returned error (%d) %s", ret, gst_flow_get_name (ret));
2649 /* fallback case, allocate a buffer of our own, add pad caps. */
2650 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "fallback buffer alloc");
2652 *buf = gst_buffer_new_and_alloc (size);
2653 GST_BUFFER_OFFSET (*buf) = offset;
2654 gst_buffer_set_caps (*buf, caps);
2660 static GstFlowReturn
2661 gst_pad_alloc_buffer_full (GstPad * pad, guint64 offset, gint size,
2662 GstCaps * caps, GstBuffer ** buf, gboolean setcaps)
2666 gboolean caps_changed;
2668 g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
2669 g_return_val_if_fail (GST_PAD_IS_SRC (pad), GST_FLOW_ERROR);
2670 g_return_val_if_fail (buf != NULL, GST_FLOW_ERROR);
2672 GST_OBJECT_LOCK (pad);
2673 while (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad)))
2674 if ((ret = handle_pad_block (pad)) != GST_FLOW_OK)
2677 if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
2680 gst_object_ref (peer);
2681 GST_OBJECT_UNLOCK (pad);
2683 ret = gst_pad_buffer_alloc_unchecked (peer, offset, size, caps, buf);
2684 gst_object_unref (peer);
2686 if (G_UNLIKELY (ret != GST_FLOW_OK))
2689 /* FIXME, move capnego this into a base class? */
2690 caps = GST_BUFFER_CAPS (*buf);
2692 /* Lock for checking caps, pretty pointless as the _pad_push() function might
2693 * change it concurrently, one of the problems with automatic caps setting in
2694 * pad_alloc_and_set_caps. Worst case, if does a check too much, but only when
2695 * there is heavy renegotiation going on in both directions. */
2696 GST_OBJECT_LOCK (pad);
2697 caps_changed = caps && caps != GST_PAD_CAPS (pad);
2698 GST_OBJECT_UNLOCK (pad);
2700 /* we got a new datatype on the pad, see if it can handle it */
2701 if (G_UNLIKELY (caps_changed)) {
2702 GST_DEBUG_OBJECT (pad, "caps changed to %p %" GST_PTR_FORMAT, caps, caps);
2703 if (G_UNLIKELY (!gst_pad_configure_src (pad, caps, setcaps)))
2704 goto not_negotiated;
2710 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "pad block stopped by flush");
2711 GST_OBJECT_UNLOCK (pad);
2716 /* pad has no peer */
2717 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
2718 "called bufferallocfunc but had no peer");
2719 GST_OBJECT_UNLOCK (pad);
2720 return GST_FLOW_NOT_LINKED;
2724 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
2725 "alloc function returned error %s", gst_flow_get_name (ret));
2730 gst_buffer_unref (*buf);
2732 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
2733 "alloc function returned unacceptable buffer");
2734 return GST_FLOW_NOT_NEGOTIATED;
2739 * gst_pad_alloc_buffer:
2740 * @pad: a source #GstPad
2741 * @offset: the offset of the new buffer in the stream
2742 * @size: the size of the new buffer
2743 * @caps: the caps of the new buffer
2744 * @buf: a newly allocated buffer
2746 * Allocates a new, empty buffer optimized to push to pad @pad. This
2747 * function only works if @pad is a source pad and has a peer.
2749 * A new, empty #GstBuffer will be put in the @buf argument.
2750 * You need to check the caps of the buffer after performing this
2751 * function and renegotiate to the format if needed.
2753 * Returns: a result code indicating success of the operation. Any
2754 * result code other than #GST_FLOW_OK is an error and @buf should
2756 * An error can occur if the pad is not connected or when the downstream
2757 * peer elements cannot provide an acceptable buffer.
2762 gst_pad_alloc_buffer (GstPad * pad, guint64 offset, gint size, GstCaps * caps,
2765 return gst_pad_alloc_buffer_full (pad, offset, size, caps, buf, FALSE);
2769 * gst_pad_alloc_buffer_and_set_caps:
2770 * @pad: a source #GstPad
2771 * @offset: the offset of the new buffer in the stream
2772 * @size: the size of the new buffer
2773 * @caps: the caps of the new buffer
2774 * @buf: a newly allocated buffer
2776 * In addition to the function gst_pad_alloc_buffer(), this function
2777 * automatically calls gst_pad_set_caps() when the caps of the
2778 * newly allocated buffer are different from the @pad caps.
2780 * Returns: a result code indicating success of the operation. Any
2781 * result code other than #GST_FLOW_OK is an error and @buf should
2783 * An error can occur if the pad is not connected or when the downstream
2784 * peer elements cannot provide an acceptable buffer.
2789 gst_pad_alloc_buffer_and_set_caps (GstPad * pad, guint64 offset, gint size,
2790 GstCaps * caps, GstBuffer ** buf)
2792 return gst_pad_alloc_buffer_full (pad, offset, size, caps, buf, TRUE);
2796 * gst_pad_get_internal_links_default:
2797 * @pad: the #GstPad to get the internal links of.
2799 * Gets a list of pads to which the given pad is linked to
2800 * inside of the parent element.
2801 * This is the default handler, and thus returns a list of all of the
2802 * pads inside the parent element with opposite direction.
2803 * The caller must free this list after use.
2805 * Returns: a newly allocated #GList of pads, or NULL if the pad has no parent.
2810 gst_pad_get_internal_links_default (GstPad * pad)
2815 GstPadDirection direction;
2817 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2819 direction = pad->direction;
2821 parent = GST_PAD_PARENT (pad);
2825 parent_pads = parent->pads;
2827 while (parent_pads) {
2828 GstPad *parent_pad = GST_PAD_CAST (parent_pads->data);
2830 if (parent_pad->direction != direction) {
2831 res = g_list_prepend (res, parent_pad);
2834 parent_pads = g_list_next (parent_pads);
2841 * gst_pad_get_internal_links:
2842 * @pad: the #GstPad to get the internal links of.
2844 * Gets a list of pads to which the given pad is linked to
2845 * inside of the parent element.
2846 * The caller must free this list after use.
2848 * Returns: a newly allocated #GList of pads.
2853 gst_pad_get_internal_links (GstPad * pad)
2857 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2859 if (GST_PAD_INTLINKFUNC (pad))
2860 res = GST_PAD_INTLINKFUNC (pad) (pad);
2867 gst_pad_event_default_dispatch (GstPad * pad, GstEvent * event)
2872 GST_INFO_OBJECT (pad, "Sending event %p (%s) to all internally linked pads",
2873 event, GST_EVENT_TYPE_NAME (event));
2875 result = (GST_PAD_DIRECTION (pad) == GST_PAD_SINK);
2877 orig = pads = gst_pad_get_internal_links (pad);
2880 GstPad *eventpad = GST_PAD_CAST (pads->data);
2882 pads = g_list_next (pads);
2884 if (GST_PAD_DIRECTION (eventpad) == GST_PAD_SRC) {
2885 /* for each pad we send to, we should ref the event; it's up
2886 * to downstream to unref again when handled. */
2887 GST_LOG_OBJECT (pad, "Reffing and sending event %p (%s) to %s:%s",
2888 event, GST_EVENT_TYPE_NAME (event), GST_DEBUG_PAD_NAME (eventpad));
2889 gst_event_ref (event);
2890 gst_pad_push_event (eventpad, event);
2892 /* we only send the event on one pad, multi-sinkpad elements
2893 * should implement a handler */
2894 GST_LOG_OBJECT (pad, "sending event %p (%s) to one sink pad %s:%s",
2895 event, GST_EVENT_TYPE_NAME (event), GST_DEBUG_PAD_NAME (eventpad));
2896 result = gst_pad_push_event (eventpad, event);
2900 /* we handled the incoming event so we unref once */
2901 GST_LOG_OBJECT (pad, "handled event %p, unreffing", event);
2902 gst_event_unref (event);
2911 * gst_pad_event_default:
2912 * @pad: a #GstPad to call the default event handler on.
2913 * @event: the #GstEvent to handle.
2915 * Invokes the default event handler for the given pad. End-of-stream and
2916 * discontinuity events are handled specially, and then the event is sent to all
2917 * pads internally linked to @pad. Note that if there are many possible sink
2918 * pads that are internally linked to @pad, only one will be sent an event.
2919 * Multi-sinkpad elements should implement custom event handlers.
2921 * Returns: TRUE if the event was sent succesfully.
2924 gst_pad_event_default (GstPad * pad, GstEvent * event)
2926 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2927 g_return_val_if_fail (event != NULL, FALSE);
2929 switch (GST_EVENT_TYPE (event)) {
2932 GST_DEBUG_OBJECT (pad, "pausing task because of eos");
2933 gst_pad_pause_task (pad);
2939 return gst_pad_event_default_dispatch (pad, event);
2943 * gst_pad_dispatcher:
2944 * @pad: a #GstPad to dispatch.
2945 * @dispatch: the #GstDispatcherFunction to call.
2946 * @data: gpointer user data passed to the dispatcher function.
2948 * Invokes the given dispatcher function on each respective peer of
2949 * all pads that are internally linked to the given pad.
2950 * The GstPadDispatcherFunction should return TRUE when no further pads
2951 * need to be processed.
2953 * Returns: TRUE if one of the dispatcher functions returned TRUE.
2956 gst_pad_dispatcher (GstPad * pad, GstPadDispatcherFunction dispatch,
2959 gboolean res = FALSE;
2960 GList *int_pads, *orig;
2962 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2963 g_return_val_if_fail (dispatch != NULL, FALSE);
2965 orig = int_pads = gst_pad_get_internal_links (pad);
2968 GstPad *int_pad = GST_PAD_CAST (int_pads->data);
2969 GstPad *int_peer = GST_PAD_PEER (int_pad);
2972 res = dispatch (int_peer, data);
2976 int_pads = g_list_next (int_pads);
2986 * @pad: a #GstPad to invoke the default query on.
2987 * @query: the #GstQuery to perform.
2989 * Dispatches a query to a pad. The query should have been allocated by the
2990 * caller via one of the type-specific allocation functions in gstquery.h. The
2991 * element is responsible for filling the query with an appropriate response,
2992 * which should then be parsed with a type-specific query parsing function.
2994 * Again, the caller is responsible for both the allocation and deallocation of
2995 * the query structure.
2997 * Returns: TRUE if the query could be performed.
3000 gst_pad_query (GstPad * pad, GstQuery * query)
3002 GstPadQueryFunction func;
3004 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
3005 g_return_val_if_fail (GST_IS_QUERY (query), FALSE);
3007 GST_DEBUG_OBJECT (pad, "sending query %p", query);
3009 if ((func = GST_PAD_QUERYFUNC (pad)) == NULL)
3012 return func (pad, query);
3016 GST_DEBUG_OBJECT (pad, "had no query function");
3022 * gst_pad_query_default:
3023 * @pad: a #GstPad to call the default query handler on.
3024 * @query: the #GstQuery to handle.
3026 * Invokes the default query handler for the given pad.
3027 * The query is sent to all pads internally linked to @pad. Note that
3028 * if there are many possible sink pads that are internally linked to
3029 * @pad, only one will be sent the query.
3030 * Multi-sinkpad elements should implement custom query handlers.
3032 * Returns: TRUE if the query was performed succesfully.
3035 gst_pad_query_default (GstPad * pad, GstQuery * query)
3037 switch (GST_QUERY_TYPE (query)) {
3038 case GST_QUERY_POSITION:
3039 case GST_QUERY_SEEKING:
3040 case GST_QUERY_FORMATS:
3041 case GST_QUERY_LATENCY:
3042 case GST_QUERY_JITTER:
3043 case GST_QUERY_RATE:
3044 case GST_QUERY_CONVERT:
3046 return gst_pad_dispatcher
3047 (pad, (GstPadDispatcherFunction) gst_pad_query, query);
3051 #ifndef GST_DISABLE_LOADSAVE
3052 /* FIXME: why isn't this on a GstElement ? */
3054 * gst_pad_load_and_link:
3055 * @self: an #xmlNodePtr to read the description from.
3056 * @parent: the #GstObject element that owns the pad.
3058 * Reads the pad definition from the XML node and links the given pad
3059 * in the element to a pad of an element up in the hierarchy.
3062 gst_pad_load_and_link (xmlNodePtr self, GstObject * parent)
3064 xmlNodePtr field = self->xmlChildrenNode;
3065 GstPad *pad = NULL, *targetpad;
3069 GstObject *grandparent;
3073 if (!strcmp ((char *) field->name, "name")) {
3074 name = (gchar *) xmlNodeGetContent (field);
3075 pad = gst_element_get_pad (GST_ELEMENT (parent), name);
3077 } else if (!strcmp ((char *) field->name, "peer")) {
3078 peer = (gchar *) xmlNodeGetContent (field);
3080 field = field->next;
3082 g_return_if_fail (pad != NULL);
3087 split = g_strsplit (peer, ".", 2);
3089 if (split[0] == NULL || split[1] == NULL) {
3090 GST_CAT_DEBUG_OBJECT (GST_CAT_XML, pad,
3091 "Could not parse peer '%s', leaving unlinked", peer);
3098 g_return_if_fail (split[0] != NULL);
3099 g_return_if_fail (split[1] != NULL);
3101 grandparent = gst_object_get_parent (parent);
3103 if (grandparent && GST_IS_BIN (grandparent)) {
3104 target = gst_bin_get_by_name_recurse_up (GST_BIN (grandparent), split[0]);
3111 targetpad = gst_element_get_pad (target, split[1]);
3113 if (targetpad == NULL)
3116 gst_pad_link (pad, targetpad);
3123 * gst_pad_save_thyself:
3124 * @pad: a #GstPad to save.
3125 * @parent: the parent #xmlNodePtr to save the description in.
3127 * Saves the pad into an xml representation.
3129 * Returns: the #xmlNodePtr representation of the pad.
3132 gst_pad_save_thyself (GstObject * object, xmlNodePtr parent)
3137 g_return_val_if_fail (GST_IS_PAD (object), NULL);
3139 pad = GST_PAD (object);
3141 xmlNewChild (parent, NULL, (xmlChar *) "name",
3142 (xmlChar *) GST_PAD_NAME (pad));
3144 if (GST_PAD_IS_SRC (pad)) {
3145 xmlNewChild (parent, NULL, (xmlChar *) "direction", (xmlChar *) "source");
3146 } else if (GST_PAD_IS_SINK (pad)) {
3147 xmlNewChild (parent, NULL, (xmlChar *) "direction", (xmlChar *) "sink");
3149 xmlNewChild (parent, NULL, (xmlChar *) "direction", (xmlChar *) "unknown");
3152 if (GST_PAD_PEER (pad) != NULL) {
3155 peer = GST_PAD_PEER (pad);
3156 /* first check to see if the peer's parent's parent is the same */
3157 /* we just save it off */
3158 content = g_strdup_printf ("%s.%s",
3159 GST_OBJECT_NAME (GST_PAD_PARENT (peer)), GST_PAD_NAME (peer));
3160 xmlNewChild (parent, NULL, (xmlChar *) "peer", (xmlChar *) content);
3163 xmlNewChild (parent, NULL, (xmlChar *) "peer", NULL);
3170 * gst_ghost_pad_save_thyself:
3171 * @pad: a ghost #GstPad to save.
3172 * @parent: the parent #xmlNodePtr to save the description in.
3174 * Saves the ghost pad into an xml representation.
3176 * Returns: the #xmlNodePtr representation of the pad.
3179 gst_ghost_pad_save_thyself (GstPad * pad, xmlNodePtr parent)
3183 g_return_val_if_fail (GST_IS_GHOST_PAD (pad), NULL);
3185 self = xmlNewChild (parent, NULL, (xmlChar *) "ghostpad", NULL);
3186 xmlNewChild (self, NULL, (xmlChar *) "name", (xmlChar *) GST_PAD_NAME (pad));
3187 xmlNewChild (self, NULL, (xmlChar *) "parent",
3188 (xmlChar *) GST_OBJECT_NAME (GST_PAD_PARENT (pad)));
3190 /* FIXME FIXME FIXME! */
3195 #endif /* GST_DISABLE_LOADSAVE */
3198 * should be called with pad OBJECT_LOCK and STREAM_LOCK held.
3199 * GST_PAD_IS_BLOCKED (pad) == TRUE when this function is
3202 * This function perform the pad blocking when an event, buffer push
3203 * or buffer_alloc is performed on a _SRC_ pad. It blocks the
3204 * streaming thread after informing the pad has been blocked.
3206 * An application can with this method wait and block any streaming
3207 * thread and perform operations such as seeking or linking.
3209 * Two methods are available for notifying the application of the
3211 * - the callback method, which happens in the STREAMING thread with
3212 * the STREAM_LOCK held. With this method, the most usefull way of
3213 * dealing with the callback is to post a message to the main thread
3214 * where the pad block can then be handled outside of the streaming
3215 * thread. With the last method one can perform all operations such
3216 * as doing a state change, linking, unblocking, seeking etc on the
3218 * - the GCond signal method, which makes any thread unblock when
3219 * the pad block happens.
3221 * During the actual blocking state, the GST_PAD_BLOCKING flag is set.
3222 * The GST_PAD_BLOCKING flag is unset when the pad was unblocked.
3226 static GstFlowReturn
3227 handle_pad_block (GstPad * pad)
3229 GstPadBlockCallback callback;
3231 GstFlowReturn ret = GST_FLOW_OK;
3233 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "signal block taken");
3235 /* flushing, don't bother trying to block and return WRONG_STATE
3237 if (GST_PAD_IS_FLUSHING (pad))
3238 goto flushingnonref;
3240 /* we grab an extra ref for the callbacks, this is probably not
3241 * needed (callback code does not have a ref and cannot unref). I
3242 * think this was done to make it possible to unref the element in
3243 * the callback, which is in the end totally impossible as it
3244 * requires grabbing the STREAM_LOCK and OBJECT_LOCK which are
3245 * all taken when calling this function. */
3246 gst_object_ref (pad);
3248 /* we either have a callback installed to notify the block or
3249 * some other thread is doing a GCond wait. */
3250 callback = pad->block_callback;
3252 /* there is a callback installed, call it. We release the
3253 * lock so that the callback can do something usefull with the
3255 user_data = pad->block_data;
3256 GST_OBJECT_UNLOCK (pad);
3257 callback (pad, TRUE, user_data);
3258 GST_OBJECT_LOCK (pad);
3260 /* we released the lock, recheck flushing */
3261 if (GST_PAD_IS_FLUSHING (pad))
3264 /* no callback, signal the thread that is doing a GCond wait
3266 GST_PAD_BLOCK_BROADCAST (pad);
3269 /* OBJECT_LOCK could have been released when we did the callback, which
3270 * then could have made the pad unblock so we need to check the blocking
3271 * condition again. */
3272 while (GST_PAD_IS_BLOCKED (pad)) {
3273 /* now we block the streaming thread. It can be unlocked when we
3274 * deactivate the pad (which will also set the FLUSHING flag) or
3275 * when the pad is unblocked. A flushing event will also unblock
3276 * the pad after setting the FLUSHING flag. */
3277 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3278 "Waiting to be unblocked or set flushing");
3279 GST_OBJECT_FLAG_SET (pad, GST_PAD_BLOCKING);
3280 GST_PAD_BLOCK_WAIT (pad);
3281 GST_OBJECT_FLAG_UNSET (pad, GST_PAD_BLOCKING);
3283 /* see if we got unblocked by a flush or not */
3284 if (GST_PAD_IS_FLUSHING (pad))
3288 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "got unblocked");
3290 /* when we get here, the pad is unblocked again and we perform
3291 * the needed unblock code. */
3292 callback = pad->block_callback;
3294 /* we need to call the callback */
3295 user_data = pad->block_data;
3296 GST_OBJECT_UNLOCK (pad);
3297 callback (pad, FALSE, user_data);
3298 GST_OBJECT_LOCK (pad);
3300 /* we need to signal the thread waiting on the GCond */
3301 GST_PAD_BLOCK_BROADCAST (pad);
3304 gst_object_unref (pad);
3310 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "pad was flushing");
3311 return GST_FLOW_WRONG_STATE;
3315 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "pad became flushing");
3316 gst_object_unref (pad);
3317 return GST_FLOW_WRONG_STATE;
3321 /**********************************************************************
3322 * Data passing functions
3326 gst_pad_emit_have_data_signal (GstPad * pad, GstMiniObject * obj)
3329 GValue args[2] = { {0}, {0} };
3334 g_value_init (&ret, G_TYPE_BOOLEAN);
3335 g_value_set_boolean (&ret, TRUE);
3336 g_value_init (&args[0], GST_TYPE_PAD);
3337 g_value_set_object (&args[0], pad);
3338 g_value_init (&args[1], GST_TYPE_MINI_OBJECT); // G_TYPE_POINTER);
3339 gst_value_set_mini_object (&args[1], obj);
3341 if (GST_IS_EVENT (obj))
3342 detail = event_quark;
3344 detail = buffer_quark;
3347 g_signal_emitv (args, gst_pad_signals[PAD_HAVE_DATA], detail, &ret);
3348 res = g_value_get_boolean (&ret);
3351 g_value_unset (&ret);
3352 g_value_unset (&args[0]);
3353 g_value_unset (&args[1]);
3358 /* this is the chain function that does not perform the additional argument
3359 * checking for that little extra speed.
3361 static inline GstFlowReturn
3362 gst_pad_chain_unchecked (GstPad * pad, GstBuffer * buffer)
3365 gboolean caps_changed;
3366 GstPadChainFunction chainfunc;
3368 gboolean emit_signal;
3370 GST_PAD_STREAM_LOCK (pad);
3372 GST_OBJECT_LOCK (pad);
3373 if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad)))
3376 caps = GST_BUFFER_CAPS (buffer);
3377 caps_changed = caps && caps != GST_PAD_CAPS (pad);
3379 emit_signal = GST_PAD_DO_BUFFER_SIGNALS (pad) > 0;
3380 GST_OBJECT_UNLOCK (pad);
3382 /* see if the signal should be emited, we emit before caps nego as
3383 * we might drop the buffer and do capsnego for nothing. */
3384 if (G_UNLIKELY (emit_signal)) {
3385 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (buffer)))
3389 /* we got a new datatype on the pad, see if it can handle it */
3390 if (G_UNLIKELY (caps_changed)) {
3391 GST_DEBUG_OBJECT (pad, "caps changed to %p %" GST_PTR_FORMAT, caps, caps);
3392 if (G_UNLIKELY (!gst_pad_configure_sink (pad, caps)))
3393 goto not_negotiated;
3396 /* NOTE: we read the chainfunc unlocked.
3397 * we cannot hold the lock for the pad so we might send
3398 * the data to the wrong function. This is not really a
3399 * problem since functions are assigned at creation time
3400 * and don't change that often... */
3401 if (G_UNLIKELY ((chainfunc = GST_PAD_CHAINFUNC (pad)) == NULL))
3404 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3405 "calling chainfunction &%s", GST_DEBUG_FUNCPTR_NAME (chainfunc));
3407 ret = chainfunc (pad, buffer);
3409 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3410 "called chainfunction &%s, returned %s",
3411 GST_DEBUG_FUNCPTR_NAME (chainfunc), gst_flow_get_name (ret));
3413 GST_PAD_STREAM_UNLOCK (pad);
3420 gst_buffer_unref (buffer);
3421 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3422 "pushing, but pad was flushing");
3423 GST_OBJECT_UNLOCK (pad);
3424 GST_PAD_STREAM_UNLOCK (pad);
3425 return GST_FLOW_WRONG_STATE;
3429 gst_buffer_unref (buffer);
3430 GST_DEBUG_OBJECT (pad, "Dropping buffer due to FALSE probe return");
3431 GST_PAD_STREAM_UNLOCK (pad);
3436 gst_buffer_unref (buffer);
3437 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3438 "pushing buffer but pad did not accept");
3439 GST_PAD_STREAM_UNLOCK (pad);
3440 return GST_FLOW_NOT_NEGOTIATED;
3444 gst_buffer_unref (buffer);
3445 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3446 "pushing, but not chainhandler");
3447 GST_ELEMENT_ERROR (GST_PAD_PARENT (pad), CORE, PAD, (NULL),
3448 ("push on pad %s:%s but it has no chainfunction",
3449 GST_DEBUG_PAD_NAME (pad)));
3450 GST_PAD_STREAM_UNLOCK (pad);
3451 return GST_FLOW_NOT_SUPPORTED;
3457 * @pad: a sink #GstPad, returns GST_FLOW_ERROR if not.
3458 * @buffer: the #GstBuffer to send, return GST_FLOW_ERROR if not.
3460 * Chain a buffer to @pad.
3462 * The function returns #GST_FLOW_WRONG_STATE if the pad was flushing.
3464 * If the caps on @buffer are different from the current caps on @pad, this
3465 * function will call any setcaps function (see gst_pad_set_setcaps_function())
3466 * installed on @pad. If the new caps are not acceptable for @pad, this function
3467 * returns #GST_FLOW_NOT_NEGOTIATED.
3469 * The function proceeds calling the chain function installed on @pad (see
3470 * gst_pad_set_chain_function()) and the return value of that function is
3471 * returned to the caller. #GST_FLOW_NOT_SUPPORTED is returned if @pad has no
3474 * In all cases, success or failure, the caller loses its reference to @buffer
3475 * after calling this function.
3477 * Returns: a #GstFlowReturn from the pad.
3482 gst_pad_chain (GstPad * pad, GstBuffer * buffer)
3484 g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
3485 g_return_val_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SINK,
3487 g_return_val_if_fail (GST_IS_BUFFER (buffer), GST_FLOW_ERROR);
3489 return gst_pad_chain_unchecked (pad, buffer);
3494 * @pad: a source #GstPad, returns #GST_FLOW_ERROR if not.
3495 * @buffer: the #GstBuffer to push returns GST_FLOW_ERROR if not.
3497 * Pushes a buffer to the peer of @pad.
3499 * This function will call an installed pad block before triggering any
3500 * installed pad probes.
3502 * If the caps on @buffer are different from the currently configured caps on
3503 * @pad, this function will call any installed setcaps function on @pad (see
3504 * gst_pad_set_setcaps_function()). In case of failure to renegotiate the new
3505 * format, this function returns #GST_FLOW_NOT_NEGOTIATED.
3507 * The function proceeds calling gst_pad_chain() on the peer pad and returns the
3508 * value from that function. If @pad has no peer, #GST_FLOW_NOT_LINKED will be
3511 * In all cases, success or failure, the caller loses its reference to @buffer
3512 * after calling this function.
3514 * Returns: a #GstFlowReturn from the peer pad.
3519 gst_pad_push (GstPad * pad, GstBuffer * buffer)
3525 gboolean caps_changed;
3527 g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
3528 g_return_val_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SRC, GST_FLOW_ERROR);
3529 g_return_val_if_fail (GST_IS_BUFFER (buffer), GST_FLOW_ERROR);
3531 GST_OBJECT_LOCK (pad);
3533 /* FIXME: this check can go away; pad_set_blocked could be implemented with
3534 * probes completely or probes with an extended pad block. */
3535 while (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad)))
3536 if ((ret = handle_pad_block (pad)) != GST_FLOW_OK)
3539 /* we emit signals on the pad arg, the peer will have a chance to
3540 * emit in the _chain() function */
3541 if (G_UNLIKELY (GST_PAD_DO_BUFFER_SIGNALS (pad) > 0)) {
3542 /* unlock before emitting */
3543 GST_OBJECT_UNLOCK (pad);
3545 /* if the signal handler returned FALSE, it means we should just drop the
3547 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (buffer)))
3550 GST_OBJECT_LOCK (pad);
3553 if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
3556 /* take ref to peer pad before releasing the lock */
3557 gst_object_ref (peer);
3559 /* Before pushing the buffer to the peer pad, ensure that caps
3560 * are set on this pad */
3561 caps = GST_BUFFER_CAPS (buffer);
3562 caps_changed = caps && caps != GST_PAD_CAPS (pad);
3564 GST_OBJECT_UNLOCK (pad);
3566 /* we got a new datatype from the pad, it had better handle it */
3567 if (G_UNLIKELY (caps_changed)) {
3568 GST_DEBUG_OBJECT (pad, "caps changed to %p %" GST_PTR_FORMAT, caps, caps);
3569 if (G_UNLIKELY (!gst_pad_configure_src (pad, caps, TRUE)))
3570 goto not_negotiated;
3573 ret = gst_pad_chain_unchecked (peer, buffer);
3575 gst_object_unref (peer);
3579 /* ERROR recovery here */
3582 gst_buffer_unref (buffer);
3583 GST_DEBUG_OBJECT (pad, "pad block stopped by flush");
3584 GST_OBJECT_UNLOCK (pad);
3589 gst_buffer_unref (buffer);
3590 GST_DEBUG_OBJECT (pad, "Dropping buffer due to FALSE probe return");
3595 gst_buffer_unref (buffer);
3596 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3597 "pushing, but it was not linked");
3598 GST_OBJECT_UNLOCK (pad);
3599 return GST_FLOW_NOT_LINKED;
3603 gst_buffer_unref (buffer);
3604 gst_object_unref (peer);
3605 GST_CAT_DEBUG_OBJECT (GST_CAT_SCHEDULING, pad,
3606 "element pushed buffer then refused to accept the caps");
3607 return GST_FLOW_NOT_NEGOTIATED;
3612 * gst_pad_check_pull_range:
3613 * @pad: a sink #GstPad.
3615 * Checks if a gst_pad_pull_range() can be performed on the peer
3616 * source pad. This function is used by plugins that want to check
3617 * if they can use random access on the peer source pad.
3619 * The peer sourcepad can implement a custom #GstPadCheckGetRangeFunction
3620 * if it needs to perform some logic to determine if pull_range is
3623 * Returns: a gboolean with the result.
3628 gst_pad_check_pull_range (GstPad * pad)
3632 GstPadCheckGetRangeFunction checkgetrangefunc;
3634 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
3636 GST_OBJECT_LOCK (pad);
3637 if (GST_PAD_DIRECTION (pad) != GST_PAD_SINK)
3638 goto wrong_direction;
3640 if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
3643 gst_object_ref (peer);
3644 GST_OBJECT_UNLOCK (pad);
3646 /* see note in above function */
3647 if (G_LIKELY ((checkgetrangefunc = peer->checkgetrangefunc) == NULL)) {
3648 /* FIXME, kindoff ghetto */
3649 ret = GST_PAD_GETRANGEFUNC (peer) != NULL;
3651 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3652 "calling checkgetrangefunc %s of peer pad %s:%s",
3653 GST_DEBUG_FUNCPTR_NAME (checkgetrangefunc), GST_DEBUG_PAD_NAME (peer));
3655 ret = checkgetrangefunc (peer);
3658 gst_object_unref (peer);
3662 /* ERROR recovery here */
3665 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3666 "checking pull range, but pad must be a sinkpad");
3667 GST_OBJECT_UNLOCK (pad);
3672 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3673 "checking pull range, but it was not linked");
3674 GST_OBJECT_UNLOCK (pad);
3680 * gst_pad_get_range:
3681 * @pad: a src #GstPad, returns #GST_FLOW_ERROR if not.
3682 * @offset: The start offset of the buffer
3683 * @size: The length of the buffer
3684 * @buffer: a pointer to hold the #GstBuffer, returns #GST_FLOW_ERROR if %NULL.
3686 * When @pad is flushing this function returns #GST_FLOW_WRONG_STATE
3689 * Calls the getrange function of @pad, see #GstPadGetRangeFunction for a
3690 * description of a getrange function. If @pad has no getrange function
3691 * installed (see gst_pad_set_getrange_function()) this function returns
3692 * #GST_FLOW_NOT_SUPPORTED.
3694 * This function will call gst_pad_set_caps() on @pad if the pull is successful
3695 * and the caps on @buffer differ from what is already set on @pad, as is done
3696 * in gst_pad_push(). This could cause the function to return
3697 * #GST_FLOW_NOT_NEGOTIATED if the caps could not be set.
3699 * Returns: a #GstFlowReturn from the pad.
3704 gst_pad_get_range (GstPad * pad, guint64 offset, guint size,
3705 GstBuffer ** buffer)
3708 GstPadGetRangeFunction getrangefunc;
3709 gboolean emit_signal;
3711 g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
3712 g_return_val_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SRC, GST_FLOW_ERROR);
3713 g_return_val_if_fail (buffer != NULL, GST_FLOW_ERROR);
3715 GST_PAD_STREAM_LOCK (pad);
3717 GST_OBJECT_LOCK (pad);
3718 if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad)))
3721 emit_signal = GST_PAD_DO_BUFFER_SIGNALS (pad) > 0;
3722 GST_OBJECT_UNLOCK (pad);
3724 if (G_UNLIKELY ((getrangefunc = GST_PAD_GETRANGEFUNC (pad)) == NULL))
3727 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3728 "calling getrangefunc %s, offset %"
3729 G_GUINT64_FORMAT ", size %u",
3730 GST_DEBUG_FUNCPTR_NAME (getrangefunc), offset, size);
3732 ret = getrangefunc (pad, offset, size, buffer);
3734 /* can only fire the signal if we have a valid buffer */
3735 if (G_UNLIKELY (emit_signal) && (ret == GST_FLOW_OK)) {
3736 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (*buffer)))
3740 GST_PAD_STREAM_UNLOCK (pad);
3742 if (G_LIKELY (ret == GST_FLOW_OK)) {
3744 gboolean caps_changed;
3746 GST_OBJECT_LOCK (pad);
3747 /* Before pushing the buffer to the peer pad, ensure that caps
3748 * are set on this pad */
3749 caps = GST_BUFFER_CAPS (*buffer);
3750 caps_changed = caps && caps != GST_PAD_CAPS (pad);
3751 GST_OBJECT_UNLOCK (pad);
3753 /* we got a new datatype from the pad, it had better handle it */
3754 if (G_UNLIKELY (caps_changed)) {
3755 GST_DEBUG_OBJECT (pad, "caps changed to %p %" GST_PTR_FORMAT, caps, caps);
3756 if (G_UNLIKELY (!gst_pad_configure_src (pad, caps, TRUE)))
3757 goto not_negotiated;
3766 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3767 "pulling range, but pad was flushing");
3768 GST_OBJECT_UNLOCK (pad);
3769 GST_PAD_STREAM_UNLOCK (pad);
3770 return GST_FLOW_WRONG_STATE;
3774 GST_ELEMENT_ERROR (GST_PAD_PARENT (pad), CORE, PAD, (NULL),
3775 ("pullrange on pad %s:%s but it has no getrangefunction",
3776 GST_DEBUG_PAD_NAME (pad)));
3777 GST_PAD_STREAM_UNLOCK (pad);
3778 return GST_FLOW_NOT_SUPPORTED;
3782 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3783 "Dropping data after FALSE probe return");
3784 GST_PAD_STREAM_UNLOCK (pad);
3785 gst_buffer_unref (*buffer);
3787 return GST_FLOW_UNEXPECTED;
3791 gst_buffer_unref (*buffer);
3793 GST_CAT_DEBUG_OBJECT (GST_CAT_SCHEDULING, pad,
3794 "getrange returned buffer then refused to accept the caps");
3795 return GST_FLOW_NOT_NEGOTIATED;
3801 * gst_pad_pull_range:
3802 * @pad: a sink #GstPad, returns GST_FLOW_ERROR if not.
3803 * @offset: The start offset of the buffer
3804 * @size: The length of the buffer
3805 * @buffer: a pointer to hold the #GstBuffer, returns GST_FLOW_ERROR if %NULL.
3807 * Pulls a buffer from the peer pad.
3809 * This function will first trigger the pad block signal if it was
3812 * When @pad is not linked #GST_FLOW_NOT_LINKED is returned else this
3813 * function returns the result of gst_pad_get_range() on the peer pad.
3814 * See gst_pad_get_range() for a list of return values and for the
3815 * semantics of the arguments of this function.
3817 * This function will call gst_pad_set_caps() on @pad if the pull is successful
3818 * and the caps on @buffer differ from what is already set on @pad, as is done
3819 * in gst_pad_chain(). This could cause the function to return
3820 * #GST_FLOW_NOT_NEGOTIATED if the caps could not be set.
3822 * Returns: a #GstFlowReturn from the peer pad.
3823 * When this function returns #GST_FLOW_OK, @buffer will contain a valid
3824 * #GstBuffer that should be freed with gst_buffer_unref() after usage.
3825 * @buffer may not be used or freed when any other return value than
3826 * #GST_FLOW_OK is returned.
3831 gst_pad_pull_range (GstPad * pad, guint64 offset, guint size,
3832 GstBuffer ** buffer)
3836 gboolean emit_signal;
3838 g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
3839 g_return_val_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SINK,
3841 g_return_val_if_fail (buffer != NULL, GST_FLOW_ERROR);
3843 GST_OBJECT_LOCK (pad);
3845 while (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad)))
3846 handle_pad_block (pad);
3848 if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
3851 /* signal emision for the pad, peer has chance to emit when
3852 * we call _get_range() */
3853 emit_signal = GST_PAD_DO_BUFFER_SIGNALS (pad) > 0;
3855 gst_object_ref (peer);
3856 GST_OBJECT_UNLOCK (pad);
3858 ret = gst_pad_get_range (peer, offset, size, buffer);
3860 gst_object_unref (peer);
3862 /* can only fire the signal if we have a valid buffer */
3863 if (G_UNLIKELY (emit_signal) && (ret == GST_FLOW_OK)) {
3864 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (*buffer)))
3868 if (G_LIKELY (ret == GST_FLOW_OK)) {
3870 gboolean caps_changed;
3872 GST_OBJECT_LOCK (pad);
3873 /* Before pushing the buffer to the peer pad, ensure that caps
3874 * are set on this pad */
3875 caps = GST_BUFFER_CAPS (*buffer);
3876 caps_changed = caps && caps != GST_PAD_CAPS (pad);
3877 GST_OBJECT_UNLOCK (pad);
3879 /* we got a new datatype on the pad, see if it can handle it */
3880 if (G_UNLIKELY (caps_changed)) {
3881 GST_DEBUG_OBJECT (pad, "caps changed to %p %" GST_PTR_FORMAT, caps, caps);
3882 if (G_UNLIKELY (!gst_pad_configure_sink (pad, caps)))
3883 goto not_negotiated;
3889 /* ERROR recovery here */
3892 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3893 "pulling range, but it was not linked");
3894 GST_OBJECT_UNLOCK (pad);
3895 return GST_FLOW_NOT_LINKED;
3899 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3900 "Dropping data after FALSE probe return");
3901 gst_buffer_unref (*buffer);
3903 return GST_FLOW_UNEXPECTED;
3907 gst_buffer_unref (*buffer);
3909 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3910 "pulled buffer but pad did not accept the caps");
3911 return GST_FLOW_NOT_NEGOTIATED;
3916 * gst_pad_push_event:
3917 * @pad: a #GstPad to push the event to.
3918 * @event: the #GstEvent to send to the pad.
3920 * Sends the event to the peer of the given pad. This function is
3921 * mainly used by elements to send events to their peer
3924 * This function takes owership of the provided event so you should
3925 * gst_event_ref() it if you want to reuse the event after this call.
3927 * Returns: TRUE if the event was handled.
3932 gst_pad_push_event (GstPad * pad, GstEvent * event)
3937 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
3938 g_return_val_if_fail (event != NULL, FALSE);
3939 g_return_val_if_fail (GST_IS_EVENT (event), FALSE);
3941 GST_LOG_OBJECT (pad, "event: %s", GST_EVENT_TYPE_NAME (event));
3943 GST_OBJECT_LOCK (pad);
3945 /* Two checks to be made:
3946 * . (un)set the FLUSHING flag for flushing events,
3947 * . handle pad blocking */
3948 switch (GST_EVENT_TYPE (event)) {
3949 case GST_EVENT_FLUSH_START:
3950 GST_PAD_SET_FLUSHING (pad);
3952 if (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad))) {
3953 /* flush start will have set the FLUSHING flag and will then
3954 * unlock all threads doing a GCond wait on the blocking pad. This
3955 * will typically unblock the STREAMING thread blocked on a pad. */
3956 GST_LOG_OBJECT (pad, "Pad is blocked, not forwarding flush-start, "
3957 "doing block signal.");
3958 GST_PAD_BLOCK_BROADCAST (pad);
3962 case GST_EVENT_FLUSH_STOP:
3963 GST_PAD_UNSET_FLUSHING (pad);
3965 /* if we are blocked, flush away the FLUSH_STOP event */
3966 if (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad))) {
3967 GST_LOG_OBJECT (pad, "Pad is blocked, not forwarding flush-stop");
3972 while (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad))) {
3973 /* block the event as long as the pad is blocked */
3974 if (handle_pad_block (pad) != GST_FLOW_OK)
3980 if (G_UNLIKELY (GST_PAD_DO_EVENT_SIGNALS (pad) > 0)) {
3981 GST_OBJECT_UNLOCK (pad);
3983 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (event)))
3986 GST_OBJECT_LOCK (pad);
3988 peerpad = GST_PAD_PEER (pad);
3989 if (peerpad == NULL)
3992 GST_LOG_OBJECT (pad, "sending event %s to peerpad %" GST_PTR_FORMAT,
3993 GST_EVENT_TYPE_NAME (event), peerpad);
3994 gst_object_ref (peerpad);
3995 GST_OBJECT_UNLOCK (pad);
3997 result = gst_pad_send_event (peerpad, event);
3999 /* Note: we gave away ownership of the event at this point */
4000 GST_LOG_OBJECT (pad, "sent event to peerpad %" GST_PTR_FORMAT, peerpad);
4001 gst_object_unref (peerpad);
4005 /* ERROR handling */
4008 GST_DEBUG_OBJECT (pad, "Dropping event after FALSE probe return");
4009 gst_event_unref (event);
4014 GST_DEBUG_OBJECT (pad, "Dropping event because pad is not linked");
4015 gst_event_unref (event);
4016 GST_OBJECT_UNLOCK (pad);
4021 GST_DEBUG_OBJECT (pad,
4022 "Not forwarding event since we're flushing and blocking");
4023 gst_event_unref (event);
4024 GST_OBJECT_UNLOCK (pad);
4030 * gst_pad_send_event:
4031 * @pad: a #GstPad to send the event to.
4032 * @event: the #GstEvent to send to the pad.
4034 * Sends the event to the pad. This function can be used
4035 * by applications to send events in the pipeline.
4037 * If @pad is a source pad, @event should be an upstream event. If @pad is a
4038 * sink pad, @event should be a downstream event. For example, you would not
4039 * send a #GST_EVENT_EOS on a src pad; EOS events only propagate downstream.
4040 * Furthermore, some downstream events have to be serialized with data flow,
4041 * like EOS, while some can travel out-of-band, like #GST_EVENT_FLUSH_START. If
4042 * the event needs to be serialized with data flow, this function will take the
4043 * pad's stream lock while calling its event function.
4045 * To find out whether an event type is upstream, downstream, or downstream and
4046 * serialized, see #GstEventTypeFlags, gst_event_type_get_flags(),
4047 * #GST_EVENT_IS_UPSTREAM, #GST_EVENT_IS_DOWNSTREAM, and
4048 * #GST_EVENT_IS_SERIALIZED. Note that in practice that an application or plugin
4049 * doesn't need to bother itself with this information; the core handles all
4050 * necessary locks and checks.
4052 * This function takes owership of the provided event so you should
4053 * gst_event_ref() it if you want to reuse the event after this call.
4055 * Returns: TRUE if the event was handled.
4058 gst_pad_send_event (GstPad * pad, GstEvent * event)
4060 gboolean result = FALSE;
4061 GstPadEventFunction eventfunc;
4062 gboolean serialized, need_unlock = FALSE;
4064 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
4065 g_return_val_if_fail (event != NULL, FALSE);
4067 GST_OBJECT_LOCK (pad);
4068 if (GST_PAD_IS_SINK (pad)) {
4069 if (G_UNLIKELY (!GST_EVENT_IS_DOWNSTREAM (event)))
4070 goto wrong_direction;
4071 serialized = GST_EVENT_IS_SERIALIZED (event);
4072 } else if (GST_PAD_IS_SRC (pad)) {
4073 if (G_UNLIKELY (!GST_EVENT_IS_UPSTREAM (event)))
4074 goto wrong_direction;
4075 /* events on srcpad never are serialized */
4078 goto unknown_direction;
4080 if (G_UNLIKELY (GST_EVENT_SRC (event) == NULL)) {
4081 GST_LOG_OBJECT (pad, "event had no source, setting pad as event source");
4082 GST_EVENT_SRC (event) = gst_object_ref (pad);
4086 if (G_UNLIKELY (GST_PAD_DO_EVENT_SIGNALS (pad) > 0)) {
4087 GST_OBJECT_UNLOCK (pad);
4089 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT_CAST (event)))
4092 GST_OBJECT_LOCK (pad);
4095 switch (GST_EVENT_TYPE (event)) {
4096 case GST_EVENT_FLUSH_START:
4097 GST_CAT_DEBUG_OBJECT (GST_CAT_EVENT, pad,
4098 "have event type %d (FLUSH_START)", GST_EVENT_TYPE (event));
4100 /* can't even accept a flush begin event when flushing */
4101 if (GST_PAD_IS_FLUSHING (pad))
4103 GST_PAD_SET_FLUSHING (pad);
4104 GST_CAT_DEBUG_OBJECT (GST_CAT_EVENT, pad, "set flush flag");
4106 case GST_EVENT_FLUSH_STOP:
4107 GST_PAD_UNSET_FLUSHING (pad);
4108 GST_CAT_DEBUG_OBJECT (GST_CAT_EVENT, pad, "cleared flush flag");
4109 GST_OBJECT_UNLOCK (pad);
4110 /* grab stream lock */
4111 GST_PAD_STREAM_LOCK (pad);
4113 GST_OBJECT_LOCK (pad);
4116 GST_CAT_DEBUG_OBJECT (GST_CAT_EVENT, pad, "have event type %s",
4117 GST_EVENT_TYPE_NAME (event));
4119 /* make this a little faster, no point in grabbing the lock
4120 * if the pad is allready flushing. */
4121 if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad)))
4125 /* lock order: STREAM_LOCK, LOCK, recheck flushing. */
4126 GST_OBJECT_UNLOCK (pad);
4127 GST_PAD_STREAM_LOCK (pad);
4129 GST_OBJECT_LOCK (pad);
4130 if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad)))
4135 if (G_UNLIKELY ((eventfunc = GST_PAD_EVENTFUNC (pad)) == NULL))
4138 GST_OBJECT_UNLOCK (pad);
4140 result = eventfunc (pad, event);
4143 GST_PAD_STREAM_UNLOCK (pad);
4147 /* ERROR handling */
4150 g_warning ("pad %s:%s sending %s event in wrong direction",
4151 GST_DEBUG_PAD_NAME (pad), GST_EVENT_TYPE_NAME (event));
4152 GST_OBJECT_UNLOCK (pad);
4153 gst_event_unref (event);
4158 g_warning ("pad %s:%s has invalid direction", GST_DEBUG_PAD_NAME (pad));
4159 GST_OBJECT_UNLOCK (pad);
4160 gst_event_unref (event);
4165 g_warning ("pad %s:%s has no event handler, file a bug.",
4166 GST_DEBUG_PAD_NAME (pad));
4167 GST_OBJECT_UNLOCK (pad);
4168 gst_event_unref (event);
4173 GST_OBJECT_UNLOCK (pad);
4175 GST_PAD_STREAM_UNLOCK (pad);
4176 GST_CAT_INFO_OBJECT (GST_CAT_EVENT, pad,
4177 "Received event on flushing pad. Discarding");
4178 gst_event_unref (event);
4183 GST_DEBUG_OBJECT (pad, "Dropping event after FALSE probe return");
4184 gst_event_unref (event);
4190 * gst_pad_set_element_private:
4191 * @pad: the #GstPad to set the private data of.
4192 * @priv: The private data to attach to the pad.
4194 * Set the given private data gpointer on the pad.
4195 * This function can only be used by the element that owns the pad.
4196 * No locking is performed in this function.
4199 gst_pad_set_element_private (GstPad * pad, gpointer priv)
4201 pad->element_private = priv;
4205 * gst_pad_get_element_private:
4206 * @pad: the #GstPad to get the private data of.
4208 * Gets the private data of a pad.
4209 * No locking is performed in this function.
4211 * Returns: a #gpointer to the private data.
4214 gst_pad_get_element_private (GstPad * pad)
4216 return pad->element_private;
4220 * gst_pad_start_task:
4221 * @pad: the #GstPad to start the task of
4222 * @func: the task function to call
4223 * @data: data passed to the task function
4225 * Starts a task that repeadedly calls @func with @data. This function
4226 * is nostly used in the pad activation function to start the
4227 * dataflow. This function will automatically acquire the #GST_PAD_STREAM_LOCK
4228 * of the pad before calling @func.
4230 * Returns: a %TRUE if the task could be started.
4233 gst_pad_start_task (GstPad * pad, GstTaskFunction func, gpointer data)
4237 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
4238 g_return_val_if_fail (func != NULL, FALSE);
4240 GST_DEBUG_OBJECT (pad, "start task");
4242 GST_OBJECT_LOCK (pad);
4243 task = GST_PAD_TASK (pad);
4245 task = gst_task_create (func, data);
4246 gst_task_set_lock (task, GST_PAD_GET_STREAM_LOCK (pad));
4247 GST_PAD_TASK (pad) = task;
4248 GST_DEBUG_OBJECT (pad, "created task");
4250 gst_task_start (task);
4251 GST_OBJECT_UNLOCK (pad);
4257 * gst_pad_pause_task:
4258 * @pad: the #GstPad to pause the task of
4260 * Pause the task of @pad. This function will also make sure that the
4261 * function executed by the task will effectively stop.
4263 * Returns: a TRUE if the task could be paused or FALSE when the pad
4267 gst_pad_pause_task (GstPad * pad)
4271 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
4273 GST_DEBUG_OBJECT (pad, "pause task");
4275 GST_OBJECT_LOCK (pad);
4276 task = GST_PAD_TASK (pad);
4279 gst_task_pause (task);
4280 GST_OBJECT_UNLOCK (pad);
4282 GST_PAD_STREAM_LOCK (pad);
4283 GST_PAD_STREAM_UNLOCK (pad);
4289 GST_DEBUG_OBJECT (pad, "pad has no task");
4290 GST_OBJECT_UNLOCK (pad);
4296 * gst_pad_stop_task:
4297 * @pad: the #GstPad to stop the task of
4299 * Stop the task of @pad. This function will also make sure that the
4300 * function executed by the task will effectively stop if not called
4301 * from the GstTaskFunction.
4303 * This function will deadlock if called from the GstTaskFunction of
4304 * the task. Use gst_task_pause() instead.
4306 * Regardless of whether the pad has a task, the stream lock is acquired and
4307 * released so as to ensure that streaming through this pad has finished.
4309 * Returns: a TRUE if the task could be stopped or FALSE on error.
4312 gst_pad_stop_task (GstPad * pad)
4316 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
4318 GST_DEBUG_OBJECT (pad, "stop task");
4320 GST_OBJECT_LOCK (pad);
4321 task = GST_PAD_TASK (pad);
4324 GST_PAD_TASK (pad) = NULL;
4325 gst_task_stop (task);
4326 GST_OBJECT_UNLOCK (pad);
4328 GST_PAD_STREAM_LOCK (pad);
4329 GST_PAD_STREAM_UNLOCK (pad);
4331 if (!gst_task_join (task))
4334 gst_object_unref (task);
4340 GST_DEBUG_OBJECT (pad, "no task");
4341 GST_OBJECT_UNLOCK (pad);
4343 GST_PAD_STREAM_LOCK (pad);
4344 GST_PAD_STREAM_UNLOCK (pad);
4346 /* this is not an error */
4351 /* this is bad, possibly the application tried to join the task from
4352 * the task's thread. We install the task again so that it will be stopped
4353 * again from the right thread next time hopefully. */
4354 GST_OBJECT_LOCK (pad);
4355 GST_DEBUG_OBJECT (pad, "join failed");
4356 /* we can only install this task if there was no other task */
4357 if (GST_PAD_TASK (pad) == NULL)
4358 GST_PAD_TASK (pad) = task;
4359 GST_OBJECT_UNLOCK (pad);