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 GST_PAD_ACTIVATE_MODE (pad) = new_mode;
580 /* unlock blocked pads so element can resume and stop */
581 GST_PAD_BLOCK_BROADCAST (pad);
582 GST_OBJECT_UNLOCK (pad);
588 post_activate (GstPad * pad, GstActivateMode new_mode)
591 case GST_ACTIVATE_PUSH:
592 case GST_ACTIVATE_PULL:
595 case GST_ACTIVATE_NONE:
596 /* ensures that streaming stops */
597 GST_PAD_STREAM_LOCK (pad);
598 GST_DEBUG_OBJECT (pad, "stopped streaming");
599 GST_PAD_STREAM_UNLOCK (pad);
605 * gst_pad_set_active:
606 * @pad: the #GstPad to activate or deactivate.
607 * @active: whether or not the pad should be active.
609 * Activates or deactivates the given pad.
610 * Normally called from within core state change functions.
612 * If @active, makes sure the pad is active. If it is already active, either in
613 * push or pull mode, just return. Otherwise dispatches to the pad's activate
614 * function to perform the actual activation.
616 * If not @active, checks the pad's current mode and calls
617 * gst_pad_activate_push() or gst_pad_activate_pull(), as appropriate, with a
620 * Returns: #TRUE if the operation was successful.
625 gst_pad_set_active (GstPad * pad, gboolean active)
628 gboolean ret = FALSE;
630 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
632 GST_OBJECT_LOCK (pad);
633 old = GST_PAD_ACTIVATE_MODE (pad);
634 GST_OBJECT_UNLOCK (pad);
638 case GST_ACTIVATE_PUSH:
639 GST_DEBUG_OBJECT (pad, "activating pad from push");
642 case GST_ACTIVATE_PULL:
643 GST_DEBUG_OBJECT (pad, "activating pad from pull");
646 case GST_ACTIVATE_NONE:
647 GST_DEBUG_OBJECT (pad, "activating pad from none");
648 ret = (GST_PAD_ACTIVATEFUNC (pad)) (pad);
653 case GST_ACTIVATE_PUSH:
654 GST_DEBUG_OBJECT (pad, "deactivating pad from push");
655 ret = gst_pad_activate_push (pad, FALSE);
657 case GST_ACTIVATE_PULL:
658 GST_DEBUG_OBJECT (pad, "deactivating pad from pull");
659 ret = gst_pad_activate_pull (pad, FALSE);
661 case GST_ACTIVATE_NONE:
662 GST_DEBUG_OBJECT (pad, "deactivating pad from none");
669 GST_OBJECT_LOCK (pad);
671 g_critical ("Failed to deactivate pad %s:%s, very bad",
672 GST_DEBUG_PAD_NAME (pad));
674 GST_WARNING_OBJECT (pad, "Failed to activate pad");
676 GST_OBJECT_UNLOCK (pad);
683 * gst_pad_activate_pull:
684 * @pad: the #GstPad to activate or deactivate.
685 * @active: whether or not the pad should be active.
687 * Activates or deactivates the given pad in pull mode via dispatching to the
688 * pad's activatepullfunc. For use from within pad activation functions only.
689 * When called on sink pads, will first proxy the call to the peer pad, which is
690 * expected to activate its internally linked pads from within its activate_pull
693 * If you don't know what this is, you probably don't want to call it.
695 * Returns: TRUE if the operation was successful.
700 gst_pad_activate_pull (GstPad * pad, gboolean active)
702 GstActivateMode old, new;
705 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
707 GST_OBJECT_LOCK (pad);
708 old = GST_PAD_ACTIVATE_MODE (pad);
709 GST_OBJECT_UNLOCK (pad);
713 case GST_ACTIVATE_PULL:
714 GST_DEBUG_OBJECT (pad, "activating pad from pull, was ok");
716 case GST_ACTIVATE_PUSH:
717 GST_DEBUG_OBJECT (pad,
718 "activating pad from push, deactivate push first");
719 /* pad was activate in the wrong direction, deactivate it
720 * and reactivate it in pull mode */
721 if (G_UNLIKELY (!gst_pad_activate_push (pad, FALSE)))
722 goto deactivate_failed;
723 /* fallthrough, pad is deactivated now. */
724 case GST_ACTIVATE_NONE:
725 GST_DEBUG_OBJECT (pad, "activating pad from none");
730 case GST_ACTIVATE_NONE:
731 GST_DEBUG_OBJECT (pad, "deactivating pad from none, was ok");
733 case GST_ACTIVATE_PUSH:
734 GST_DEBUG_OBJECT (pad, "deactivating pad from push, weird");
735 /* pad was activated in the other direction, deactivate it
736 * in push mode, this should not happen... */
737 if (G_UNLIKELY (!gst_pad_activate_push (pad, FALSE)))
738 goto deactivate_failed;
739 /* everything is fine now */
741 case GST_ACTIVATE_PULL:
742 GST_DEBUG_OBJECT (pad, "deactivating pad from pull");
747 if (gst_pad_get_direction (pad) == GST_PAD_SINK) {
748 if ((peer = gst_pad_get_peer (pad))) {
749 GST_DEBUG_OBJECT (pad, "calling peer");
750 if (G_UNLIKELY (!gst_pad_activate_pull (peer, active)))
752 gst_object_unref (peer);
757 if (G_UNLIKELY (GST_PAD_GETRANGEFUNC (pad) == NULL))
758 goto failure; /* Can't activate pull on a src without a
762 new = active ? GST_ACTIVATE_PULL : GST_ACTIVATE_NONE;
763 pre_activate (pad, new);
765 if (GST_PAD_ACTIVATEPULLFUNC (pad)) {
766 if (G_UNLIKELY (!GST_PAD_ACTIVATEPULLFUNC (pad) (pad, active)))
769 /* can happen for sinks of passthrough elements */
772 post_activate (pad, new);
774 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "%s in pull mode",
775 active ? "activated" : "deactivated");
781 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "already %s in pull mode",
782 active ? "activated" : "deactivated");
787 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
788 "failed to %s in switch to pull from mode %d",
789 (active ? "activate" : "deactivate"), old);
794 GST_OBJECT_LOCK (peer);
795 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
796 "activate_pull on peer (%s:%s) failed", GST_DEBUG_PAD_NAME (peer));
797 GST_OBJECT_UNLOCK (peer);
798 gst_object_unref (peer);
803 GST_CAT_INFO_OBJECT (GST_CAT_PADS, pad, "can't activate unlinked sink "
809 GST_OBJECT_LOCK (pad);
810 GST_CAT_INFO_OBJECT (GST_CAT_PADS, pad, "failed to %s in pull mode",
811 active ? "activate" : "deactivate");
812 GST_PAD_SET_FLUSHING (pad);
813 GST_PAD_ACTIVATE_MODE (pad) = old;
814 GST_OBJECT_UNLOCK (pad);
820 * gst_pad_activate_push:
821 * @pad: the #GstPad to activate or deactivate.
822 * @active: whether the pad should be active or not.
824 * Activates or deactivates the given pad in push mode via dispatching to the
825 * pad's activatepushfunc. For use from within pad activation functions only.
827 * If you don't know what this is, you probably don't want to call it.
829 * Returns: %TRUE if the operation was successful.
834 gst_pad_activate_push (GstPad * pad, gboolean active)
836 GstActivateMode old, new;
838 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
839 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "trying to set %s in push mode",
840 active ? "activated" : "deactivated");
842 GST_OBJECT_LOCK (pad);
843 old = GST_PAD_ACTIVATE_MODE (pad);
844 GST_OBJECT_UNLOCK (pad);
848 case GST_ACTIVATE_PUSH:
849 GST_DEBUG_OBJECT (pad, "activating pad from push, was ok");
851 case GST_ACTIVATE_PULL:
852 GST_DEBUG_OBJECT (pad,
853 "activating pad from push, deactivating pull first");
854 /* pad was activate in the wrong direction, deactivate it
855 * an reactivate it in push mode */
856 if (G_UNLIKELY (!gst_pad_activate_pull (pad, FALSE)))
857 goto deactivate_failed;
858 /* fallthrough, pad is deactivated now. */
859 case GST_ACTIVATE_NONE:
860 GST_DEBUG_OBJECT (pad, "activating pad from none");
865 case GST_ACTIVATE_NONE:
866 GST_DEBUG_OBJECT (pad, "deactivating pad from none, was ok");
868 case GST_ACTIVATE_PULL:
869 GST_DEBUG_OBJECT (pad, "deactivating pad from pull, weird");
870 /* pad was activated in the other direction, deactivate it
871 * in pull mode, this should not happen... */
872 if (G_UNLIKELY (!gst_pad_activate_pull (pad, FALSE)))
873 goto deactivate_failed;
874 /* everything is fine now */
876 case GST_ACTIVATE_PUSH:
877 GST_DEBUG_OBJECT (pad, "deactivating pad from push");
882 new = active ? GST_ACTIVATE_PUSH : GST_ACTIVATE_NONE;
883 pre_activate (pad, new);
885 if (GST_PAD_ACTIVATEPUSHFUNC (pad)) {
886 if (G_UNLIKELY (!GST_PAD_ACTIVATEPUSHFUNC (pad) (pad, active))) {
890 /* quite ok, element relies on state change func to prepare itself */
893 post_activate (pad, new);
895 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "%s in push mode",
896 active ? "activated" : "deactivated");
901 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "already %s in push mode",
902 active ? "activated" : "deactivated");
907 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
908 "failed to %s in switch to push from mode %d",
909 (active ? "activate" : "deactivate"), old);
914 GST_OBJECT_LOCK (pad);
915 GST_CAT_INFO_OBJECT (GST_CAT_PADS, pad, "failed to %s in push mode",
916 active ? "activate" : "deactivate");
917 GST_PAD_SET_FLUSHING (pad);
918 GST_PAD_ACTIVATE_MODE (pad) = old;
919 GST_OBJECT_UNLOCK (pad);
926 * @pad: the #GstPad to query
928 * Query if a pad is active
930 * Returns: TRUE if the pad is active.
935 gst_pad_is_active (GstPad * pad)
937 gboolean result = FALSE;
939 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
941 GST_OBJECT_LOCK (pad);
942 result = GST_PAD_MODE_ACTIVATE (GST_PAD_ACTIVATE_MODE (pad));
943 GST_OBJECT_UNLOCK (pad);
949 * gst_pad_set_blocked_async:
950 * @pad: the #GstPad to block or unblock
951 * @blocked: boolean indicating whether the pad should be blocked or unblocked
952 * @callback: #GstPadBlockCallback that will be called when the
954 * @user_data: user data passed to the callback
956 * Blocks or unblocks the dataflow on a pad. The provided callback
957 * is called when the operation succeeds; this happens right before the next
958 * attempt at pushing a buffer on the pad.
960 * This can take a while as the pad can only become blocked when real dataflow
962 * When the pipeline is stalled, for example in PAUSED, this can
963 * take an indeterminate amount of time.
964 * You can pass NULL as the callback to make this call block. Be careful with
965 * this blocking call as it might not return for reasons stated above.
967 * Returns: TRUE if the pad could be blocked. This function can fail
968 * if wrong parameters were passed or the pad was already in the
974 gst_pad_set_blocked_async (GstPad * pad, gboolean blocked,
975 GstPadBlockCallback callback, gpointer user_data)
977 gboolean was_blocked = FALSE;
979 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
981 GST_OBJECT_LOCK (pad);
983 was_blocked = GST_PAD_IS_BLOCKED (pad);
985 if (G_UNLIKELY (was_blocked == blocked))
986 goto had_right_state;
989 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "blocking pad");
991 GST_OBJECT_FLAG_SET (pad, GST_PAD_BLOCKED);
992 pad->block_callback = callback;
993 pad->block_data = user_data;
995 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "waiting for block");
996 GST_PAD_BLOCK_WAIT (pad);
997 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "blocked");
1000 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "unblocking pad");
1002 GST_OBJECT_FLAG_UNSET (pad, GST_PAD_BLOCKED);
1004 pad->block_callback = callback;
1005 pad->block_data = user_data;
1007 GST_PAD_BLOCK_BROADCAST (pad);
1009 /* no callback, wait for the unblock to happen */
1010 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "waiting for unblock");
1011 GST_PAD_BLOCK_WAIT (pad);
1012 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "unblocked");
1015 GST_OBJECT_UNLOCK (pad);
1021 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
1022 "pad was in right state (%d)", was_blocked);
1023 GST_OBJECT_UNLOCK (pad);
1030 * gst_pad_set_blocked:
1031 * @pad: the #GstPad to block or unblock
1032 * @blocked: boolean indicating we should block or unblock
1034 * Blocks or unblocks the dataflow on a pad. This function is
1035 * a shortcut for gst_pad_set_blocked_async() with a NULL
1038 * Returns: TRUE if the pad could be blocked. This function can fail
1039 * wrong parameters were passed or the pad was already in the
1045 gst_pad_set_blocked (GstPad * pad, gboolean blocked)
1047 return gst_pad_set_blocked_async (pad, blocked, NULL, NULL);
1051 * gst_pad_is_blocked:
1052 * @pad: the #GstPad to query
1054 * Checks if the pad is blocked or not. This function returns the
1055 * last requested state of the pad. It is not certain that the pad
1056 * is actually blocking at this point (see gst_pad_is_blocking()).
1058 * Returns: TRUE if the pad is blocked.
1063 gst_pad_is_blocked (GstPad * pad)
1065 gboolean result = FALSE;
1067 g_return_val_if_fail (GST_IS_PAD (pad), result);
1069 GST_OBJECT_LOCK (pad);
1070 result = GST_OBJECT_FLAG_IS_SET (pad, GST_PAD_BLOCKED);
1071 GST_OBJECT_UNLOCK (pad);
1077 * gst_pad_is_blocking:
1078 * @pad: the #GstPad to query
1080 * Checks if the pad is blocking or not. This is a guaranteed state
1081 * of whether the pad is actually blocking on a #GstBuffer or a #GstEvent.
1083 * Returns: TRUE if the pad is blocking.
1090 gst_pad_is_blocking (GstPad * pad)
1092 gboolean result = FALSE;
1094 g_return_val_if_fail (GST_IS_PAD (pad), result);
1096 GST_OBJECT_LOCK (pad);
1097 /* the blocking flag is only valid if the pad is not flushing */
1098 result = GST_OBJECT_FLAG_IS_SET (pad, GST_PAD_BLOCKING) &&
1099 !GST_OBJECT_FLAG_IS_SET (pad, GST_PAD_FLUSHING);
1100 GST_OBJECT_UNLOCK (pad);
1106 * gst_pad_set_activate_function:
1108 * @activate: the #GstPadActivateFunction to set.
1110 * Sets the given activate function for @pad. The activate function will
1111 * dispatch to gst_pad_activate_push() or gst_pad_activate_pull() to perform
1112 * the actual activation. Only makes sense to set on sink pads.
1114 * Call this function if your sink pad can start a pull-based task.
1117 gst_pad_set_activate_function (GstPad * pad, GstPadActivateFunction activate)
1119 g_return_if_fail (GST_IS_PAD (pad));
1121 GST_PAD_ACTIVATEFUNC (pad) = activate;
1122 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "activatefunc set to %s",
1123 GST_DEBUG_FUNCPTR_NAME (activate));
1127 * gst_pad_set_activatepull_function:
1129 * @activatepull: the #GstPadActivateModeFunction to set.
1131 * Sets the given activate_pull function for the pad. An activate_pull function
1132 * prepares the element and any upstream connections for pulling. See XXX
1133 * part-activation.txt for details.
1136 gst_pad_set_activatepull_function (GstPad * pad,
1137 GstPadActivateModeFunction activatepull)
1139 g_return_if_fail (GST_IS_PAD (pad));
1141 GST_PAD_ACTIVATEPULLFUNC (pad) = activatepull;
1142 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "activatepullfunc set to %s",
1143 GST_DEBUG_FUNCPTR_NAME (activatepull));
1147 * gst_pad_set_activatepush_function:
1149 * @activatepush: the #GstPadActivateModeFunction to set.
1151 * Sets the given activate_push function for the pad. An activate_push function
1152 * prepares the element for pushing. See XXX part-activation.txt for details.
1155 gst_pad_set_activatepush_function (GstPad * pad,
1156 GstPadActivateModeFunction activatepush)
1158 g_return_if_fail (GST_IS_PAD (pad));
1160 GST_PAD_ACTIVATEPUSHFUNC (pad) = activatepush;
1161 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "activatepushfunc set to %s",
1162 GST_DEBUG_FUNCPTR_NAME (activatepush));
1166 * gst_pad_set_chain_function:
1167 * @pad: a sink #GstPad.
1168 * @chain: the #GstPadChainFunction to set.
1170 * Sets the given chain function for the pad. The chain function is called to
1171 * process a #GstBuffer input buffer. see #GstPadChainFunction for more details.
1174 gst_pad_set_chain_function (GstPad * pad, GstPadChainFunction chain)
1176 g_return_if_fail (GST_IS_PAD (pad));
1177 g_return_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SINK);
1179 GST_PAD_CHAINFUNC (pad) = chain;
1180 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "chainfunc set to %s",
1181 GST_DEBUG_FUNCPTR_NAME (chain));
1185 * gst_pad_set_getrange_function:
1186 * @pad: a source #GstPad.
1187 * @get: the #GstPadGetRangeFunction to set.
1189 * Sets the given getrange function for the pad. The getrange function is called to
1190 * produce a new #GstBuffer to start the processing pipeline. see
1191 * #GstPadGetRangeFunction for a description of the getrange function.
1194 gst_pad_set_getrange_function (GstPad * pad, GstPadGetRangeFunction get)
1196 g_return_if_fail (GST_IS_PAD (pad));
1197 g_return_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SRC);
1199 GST_PAD_GETRANGEFUNC (pad) = get;
1201 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "getrangefunc set to %s",
1202 GST_DEBUG_FUNCPTR_NAME (get));
1206 * gst_pad_set_checkgetrange_function:
1207 * @pad: a source #GstPad.
1208 * @check: the #GstPadCheckGetRangeFunction to set.
1210 * Sets the given checkgetrange function for the pad. Implement this function on
1211 * a pad if you dynamically support getrange based scheduling on the pad.
1214 gst_pad_set_checkgetrange_function (GstPad * pad,
1215 GstPadCheckGetRangeFunction check)
1217 g_return_if_fail (GST_IS_PAD (pad));
1218 g_return_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SRC);
1220 GST_PAD_CHECKGETRANGEFUNC (pad) = check;
1222 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "checkgetrangefunc set to %s",
1223 GST_DEBUG_FUNCPTR_NAME (check));
1227 * gst_pad_set_event_function:
1228 * @pad: a source #GstPad.
1229 * @event: the #GstPadEventFunction to set.
1231 * Sets the given event handler for the pad.
1234 gst_pad_set_event_function (GstPad * pad, GstPadEventFunction event)
1236 g_return_if_fail (GST_IS_PAD (pad));
1238 GST_PAD_EVENTFUNC (pad) = event;
1240 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "eventfunc for set to %s",
1241 GST_DEBUG_FUNCPTR_NAME (event));
1245 * gst_pad_set_query_function:
1246 * @pad: a #GstPad of either direction.
1247 * @query: the #GstPadQueryFunction to set.
1249 * Set the given query function for the pad.
1252 gst_pad_set_query_function (GstPad * pad, GstPadQueryFunction query)
1254 g_return_if_fail (GST_IS_PAD (pad));
1256 GST_PAD_QUERYFUNC (pad) = query;
1258 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "queryfunc set to %s",
1259 GST_DEBUG_FUNCPTR_NAME (query));
1263 * gst_pad_set_query_type_function:
1264 * @pad: a #GstPad of either direction.
1265 * @type_func: the #GstPadQueryTypeFunction to set.
1267 * Set the given query type function for the pad.
1270 gst_pad_set_query_type_function (GstPad * pad,
1271 GstPadQueryTypeFunction type_func)
1273 g_return_if_fail (GST_IS_PAD (pad));
1275 GST_PAD_QUERYTYPEFUNC (pad) = type_func;
1277 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "querytypefunc set to %s",
1278 GST_DEBUG_FUNCPTR_NAME (type_func));
1282 * gst_pad_get_query_types:
1285 * Get an array of supported queries that can be performed
1288 * Returns: a zero-terminated array of #GstQueryType.
1290 const GstQueryType *
1291 gst_pad_get_query_types (GstPad * pad)
1293 GstPadQueryTypeFunction func;
1295 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
1297 if (G_UNLIKELY ((func = GST_PAD_QUERYTYPEFUNC (pad)) == NULL))
1309 gst_pad_get_query_types_dispatcher (GstPad * pad, const GstQueryType ** data)
1311 *data = gst_pad_get_query_types (pad);
1317 * gst_pad_get_query_types_default:
1320 * Invoke the default dispatcher for the query types on
1323 * Returns: an zero-terminated array of #GstQueryType, or NULL if none of the
1324 * internally-linked pads has a query types function.
1326 const GstQueryType *
1327 gst_pad_get_query_types_default (GstPad * pad)
1329 GstQueryType *result = NULL;
1331 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
1333 gst_pad_dispatcher (pad, (GstPadDispatcherFunction)
1334 gst_pad_get_query_types_dispatcher, &result);
1340 * gst_pad_set_internal_link_function:
1341 * @pad: a #GstPad of either direction.
1342 * @intlink: the #GstPadIntLinkFunction to set.
1344 * Sets the given internal link function for the pad.
1347 gst_pad_set_internal_link_function (GstPad * pad, GstPadIntLinkFunction intlink)
1349 g_return_if_fail (GST_IS_PAD (pad));
1351 GST_PAD_INTLINKFUNC (pad) = intlink;
1352 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "internal link set to %s",
1353 GST_DEBUG_FUNCPTR_NAME (intlink));
1357 * gst_pad_set_link_function:
1359 * @link: the #GstPadLinkFunction to set.
1361 * Sets the given link function for the pad. It will be called when
1362 * the pad is linked with another pad.
1364 * The return value #GST_PAD_LINK_OK should be used when the connection can be
1367 * The return value #GST_PAD_LINK_REFUSED should be used when the connection
1368 * cannot be made for some reason.
1370 * If @link is installed on a source pad, it should call the #GstPadLinkFunction
1371 * of the peer sink pad, if present.
1374 gst_pad_set_link_function (GstPad * pad, GstPadLinkFunction link)
1376 g_return_if_fail (GST_IS_PAD (pad));
1378 GST_PAD_LINKFUNC (pad) = link;
1379 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "linkfunc set to %s",
1380 GST_DEBUG_FUNCPTR_NAME (link));
1384 * gst_pad_set_unlink_function:
1386 * @unlink: the #GstPadUnlinkFunction to set.
1388 * Sets the given unlink function for the pad. It will be called
1389 * when the pad is unlinked.
1392 gst_pad_set_unlink_function (GstPad * pad, GstPadUnlinkFunction unlink)
1394 g_return_if_fail (GST_IS_PAD (pad));
1396 GST_PAD_UNLINKFUNC (pad) = unlink;
1397 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "unlinkfunc set to %s",
1398 GST_DEBUG_FUNCPTR_NAME (unlink));
1402 * gst_pad_set_getcaps_function:
1404 * @getcaps: the #GstPadGetCapsFunction to set.
1406 * Sets the given getcaps function for the pad. @getcaps should return the
1407 * allowable caps for a pad in the context of the element's state, its link to
1408 * other elements, and the devices or files it has opened. These caps must be a
1409 * subset of the pad template caps. In the NULL state with no links, @getcaps
1410 * should ideally return the same caps as the pad template. In rare
1411 * circumstances, an object property can affect the caps returned by @getcaps,
1412 * but this is discouraged.
1414 * You do not need to call this function if @pad's allowed caps are always the
1415 * same as the pad template caps. This can only be true if the padtemplate
1416 * has fixed simple caps.
1418 * For most filters, the caps returned by @getcaps is directly affected by the
1419 * allowed caps on other pads. For demuxers and decoders, the caps returned by
1420 * the srcpad's getcaps function is directly related to the stream data. Again,
1421 * @getcaps should return the most specific caps it reasonably can, since this
1422 * helps with autoplugging.
1424 * Note that the return value from @getcaps is owned by the caller, so the caller
1425 * should unref the caps after usage.
1428 gst_pad_set_getcaps_function (GstPad * pad, GstPadGetCapsFunction getcaps)
1430 g_return_if_fail (GST_IS_PAD (pad));
1432 GST_PAD_GETCAPSFUNC (pad) = getcaps;
1433 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "getcapsfunc set to %s",
1434 GST_DEBUG_FUNCPTR_NAME (getcaps));
1438 * gst_pad_set_acceptcaps_function:
1440 * @acceptcaps: the #GstPadAcceptCapsFunction to set.
1442 * Sets the given acceptcaps function for the pad. The acceptcaps function
1443 * will be called to check if the pad can accept the given caps. Setting the
1444 * acceptcaps function to NULL restores the default behaviour of allowing
1445 * any caps that matches the caps from gst_pad_get_caps.
1448 gst_pad_set_acceptcaps_function (GstPad * pad,
1449 GstPadAcceptCapsFunction acceptcaps)
1451 g_return_if_fail (GST_IS_PAD (pad));
1453 GST_PAD_ACCEPTCAPSFUNC (pad) = acceptcaps;
1454 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "acceptcapsfunc set to %s",
1455 GST_DEBUG_FUNCPTR_NAME (acceptcaps));
1459 * gst_pad_set_fixatecaps_function:
1461 * @fixatecaps: the #GstPadFixateCapsFunction to set.
1463 * Sets the given fixatecaps function for the pad. The fixatecaps function
1464 * will be called whenever the default values for a GstCaps needs to be
1468 gst_pad_set_fixatecaps_function (GstPad * pad,
1469 GstPadFixateCapsFunction fixatecaps)
1471 g_return_if_fail (GST_IS_PAD (pad));
1473 GST_PAD_FIXATECAPSFUNC (pad) = fixatecaps;
1474 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "fixatecapsfunc set to %s",
1475 GST_DEBUG_FUNCPTR_NAME (fixatecaps));
1479 * gst_pad_set_setcaps_function:
1481 * @setcaps: the #GstPadSetCapsFunction to set.
1483 * Sets the given setcaps function for the pad. The setcaps function
1484 * will be called whenever a buffer with a new media type is pushed or
1485 * pulled from the pad. The pad/element needs to update its internal
1486 * structures to process the new media type. If this new type is not
1487 * acceptable, the setcaps function should return FALSE.
1490 gst_pad_set_setcaps_function (GstPad * pad, GstPadSetCapsFunction setcaps)
1492 g_return_if_fail (GST_IS_PAD (pad));
1494 GST_PAD_SETCAPSFUNC (pad) = setcaps;
1495 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "setcapsfunc set to %s",
1496 GST_DEBUG_FUNCPTR_NAME (setcaps));
1500 * gst_pad_set_bufferalloc_function:
1501 * @pad: a sink #GstPad.
1502 * @bufalloc: the #GstPadBufferAllocFunction to set.
1504 * Sets the given bufferalloc function for the pad. Note that the
1505 * bufferalloc function can only be set on sinkpads.
1508 gst_pad_set_bufferalloc_function (GstPad * pad,
1509 GstPadBufferAllocFunction bufalloc)
1511 g_return_if_fail (GST_IS_PAD (pad));
1512 g_return_if_fail (GST_PAD_IS_SINK (pad));
1514 GST_PAD_BUFFERALLOCFUNC (pad) = bufalloc;
1515 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "bufferallocfunc set to %s",
1516 GST_DEBUG_FUNCPTR_NAME (bufalloc));
1521 * @srcpad: the source #GstPad to unlink.
1522 * @sinkpad: the sink #GstPad to unlink.
1524 * Unlinks the source pad from the sink pad. Will emit the "unlinked" signal on
1527 * Returns: TRUE if the pads were unlinked. This function returns FALSE if
1528 * the pads were not linked together.
1533 gst_pad_unlink (GstPad * srcpad, GstPad * sinkpad)
1535 g_return_val_if_fail (GST_IS_PAD (srcpad), FALSE);
1536 g_return_val_if_fail (GST_IS_PAD (sinkpad), FALSE);
1538 GST_CAT_INFO (GST_CAT_ELEMENT_PADS, "unlinking %s:%s(%p) and %s:%s(%p)",
1539 GST_DEBUG_PAD_NAME (srcpad), srcpad,
1540 GST_DEBUG_PAD_NAME (sinkpad), sinkpad);
1542 GST_OBJECT_LOCK (srcpad);
1544 if (G_UNLIKELY (GST_PAD_DIRECTION (srcpad) != GST_PAD_SRC))
1547 GST_OBJECT_LOCK (sinkpad);
1549 if (G_UNLIKELY (GST_PAD_DIRECTION (sinkpad) != GST_PAD_SINK))
1552 if (G_UNLIKELY (GST_PAD_PEER (srcpad) != sinkpad))
1553 goto not_linked_together;
1555 if (GST_PAD_UNLINKFUNC (srcpad)) {
1556 GST_PAD_UNLINKFUNC (srcpad) (srcpad);
1558 if (GST_PAD_UNLINKFUNC (sinkpad)) {
1559 GST_PAD_UNLINKFUNC (sinkpad) (sinkpad);
1562 /* first clear peers */
1563 GST_PAD_PEER (srcpad) = NULL;
1564 GST_PAD_PEER (sinkpad) = NULL;
1566 GST_OBJECT_UNLOCK (sinkpad);
1567 GST_OBJECT_UNLOCK (srcpad);
1569 /* fire off a signal to each of the pads telling them
1570 * that they've been unlinked */
1571 g_signal_emit (G_OBJECT (srcpad), gst_pad_signals[PAD_UNLINKED], 0, sinkpad);
1572 g_signal_emit (G_OBJECT (sinkpad), gst_pad_signals[PAD_UNLINKED], 0, srcpad);
1574 GST_CAT_INFO (GST_CAT_ELEMENT_PADS, "unlinked %s:%s and %s:%s",
1575 GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (sinkpad));
1581 g_critical ("pad %s is not a source pad", GST_PAD_NAME (srcpad));
1582 GST_OBJECT_UNLOCK (srcpad);
1587 g_critical ("pad %s is not a sink pad", GST_PAD_NAME (sinkpad));
1588 GST_OBJECT_UNLOCK (sinkpad);
1589 GST_OBJECT_UNLOCK (srcpad);
1592 not_linked_together:
1594 /* we do not emit a warning in this case because unlinking cannot
1595 * be made MT safe.*/
1596 GST_OBJECT_UNLOCK (sinkpad);
1597 GST_OBJECT_UNLOCK (srcpad);
1603 * gst_pad_is_linked:
1604 * @pad: pad to check
1606 * Checks if a @pad is linked to another pad or not.
1608 * Returns: TRUE if the pad is linked, FALSE otherwise.
1613 gst_pad_is_linked (GstPad * pad)
1617 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
1619 GST_OBJECT_LOCK (pad);
1620 result = (GST_PAD_PEER (pad) != NULL);
1621 GST_OBJECT_UNLOCK (pad);
1626 /* get the caps from both pads and see if the intersection
1629 * This function should be called with the pad LOCK on both
1633 gst_pad_link_check_compatible_unlocked (GstPad * src, GstPad * sink)
1639 srccaps = gst_pad_get_caps_unlocked (src);
1640 sinkcaps = gst_pad_get_caps_unlocked (sink);
1642 GST_CAT_DEBUG (GST_CAT_CAPS, "src caps %" GST_PTR_FORMAT, srccaps);
1643 GST_CAT_DEBUG (GST_CAT_CAPS, "sink caps %" GST_PTR_FORMAT, sinkcaps);
1645 /* if we have caps on both pads we can check the intersection. If one
1646 * of the caps is NULL, we return TRUE. */
1647 if (srccaps == NULL || sinkcaps == NULL)
1650 icaps = gst_caps_intersect (srccaps, sinkcaps);
1651 gst_caps_unref (srccaps);
1652 gst_caps_unref (sinkcaps);
1657 GST_CAT_DEBUG (GST_CAT_CAPS,
1658 "intersection caps %p %" GST_PTR_FORMAT, icaps, icaps);
1660 if (gst_caps_is_empty (icaps))
1663 gst_caps_unref (icaps);
1668 /* incompatible cases */
1671 GST_CAT_DEBUG (GST_CAT_CAPS, "intersection gave NULL");
1676 GST_CAT_DEBUG (GST_CAT_CAPS, "intersection is EMPTY");
1677 gst_caps_unref (icaps);
1682 /* check if the grandparents of both pads are the same.
1683 * This check is required so that we don't try to link
1684 * pads from elements in different bins without ghostpads.
1686 * The LOCK should be held on both pads
1689 gst_pad_link_check_hierarchy (GstPad * src, GstPad * sink)
1691 GstObject *psrc, *psink;
1693 psrc = GST_OBJECT_PARENT (src);
1694 psink = GST_OBJECT_PARENT (sink);
1696 /* if one of the pads has no parent, we allow the link */
1697 if (G_UNLIKELY (psrc == NULL || psink == NULL))
1700 /* if the parents are the same, we have a loop */
1701 if (G_UNLIKELY (psrc == psink))
1704 /* if they both have a parent, we check the grandparents. We can not lock
1705 * the parent because we hold on the child (pad) and the locking order is
1706 * parent >> child. */
1707 psrc = GST_OBJECT_PARENT (psrc);
1708 psink = GST_OBJECT_PARENT (psink);
1710 /* if they have grandparents but they are not the same */
1711 if (G_UNLIKELY (psrc != psink))
1712 goto wrong_grandparents;
1719 GST_CAT_DEBUG (GST_CAT_CAPS,
1720 "one of the pads has no parent %" GST_PTR_FORMAT " and %"
1721 GST_PTR_FORMAT, psrc, psink);
1726 GST_CAT_DEBUG (GST_CAT_CAPS, "pads have same parent %" GST_PTR_FORMAT,
1732 GST_CAT_DEBUG (GST_CAT_CAPS,
1733 "pads have different grandparents %" GST_PTR_FORMAT " and %"
1734 GST_PTR_FORMAT, psrc, psink);
1739 /* FIXME leftover from an attempt at refactoring... */
1740 /* call with the two pads unlocked, when this function returns GST_PAD_LINK_OK,
1741 * the two pads will be locked in the srcpad, sinkpad order. */
1742 static GstPadLinkReturn
1743 gst_pad_link_prepare (GstPad * srcpad, GstPad * sinkpad)
1745 /* generic checks */
1746 g_return_val_if_fail (GST_IS_PAD (srcpad), GST_PAD_LINK_REFUSED);
1747 g_return_val_if_fail (GST_IS_PAD (sinkpad), GST_PAD_LINK_REFUSED);
1749 GST_CAT_INFO (GST_CAT_PADS, "trying to link %s:%s and %s:%s",
1750 GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (sinkpad));
1752 GST_OBJECT_LOCK (srcpad);
1754 if (G_UNLIKELY (GST_PAD_DIRECTION (srcpad) != GST_PAD_SRC))
1757 if (G_UNLIKELY (GST_PAD_PEER (srcpad) != NULL))
1758 goto src_was_linked;
1760 GST_OBJECT_LOCK (sinkpad);
1762 if (G_UNLIKELY (GST_PAD_DIRECTION (sinkpad) != GST_PAD_SINK))
1765 if (G_UNLIKELY (GST_PAD_PEER (sinkpad) != NULL))
1766 goto sink_was_linked;
1768 /* check hierarchy, pads can only be linked if the grandparents
1770 if (!gst_pad_link_check_hierarchy (srcpad, sinkpad))
1771 goto wrong_hierarchy;
1773 /* check pad caps for non-empty intersection */
1774 if (!gst_pad_link_check_compatible_unlocked (srcpad, sinkpad))
1777 /* FIXME check pad scheduling for non-empty intersection */
1779 return GST_PAD_LINK_OK;
1783 g_critical ("pad %s is not a source pad", GST_PAD_NAME (srcpad));
1784 GST_OBJECT_UNLOCK (srcpad);
1785 return GST_PAD_LINK_WRONG_DIRECTION;
1789 GST_CAT_INFO (GST_CAT_PADS, "src %s:%s was already linked to %s:%s",
1790 GST_DEBUG_PAD_NAME (srcpad),
1791 GST_DEBUG_PAD_NAME (GST_PAD_PEER (srcpad)));
1792 /* we do not emit a warning in this case because unlinking cannot
1793 * be made MT safe.*/
1794 GST_OBJECT_UNLOCK (srcpad);
1795 return GST_PAD_LINK_WAS_LINKED;
1799 g_critical ("pad %s is not a sink pad", GST_PAD_NAME (sinkpad));
1800 GST_OBJECT_UNLOCK (sinkpad);
1801 GST_OBJECT_UNLOCK (srcpad);
1802 return GST_PAD_LINK_WRONG_DIRECTION;
1806 GST_CAT_INFO (GST_CAT_PADS, "sink %s:%s was already linked to %s:%s",
1807 GST_DEBUG_PAD_NAME (sinkpad),
1808 GST_DEBUG_PAD_NAME (GST_PAD_PEER (sinkpad)));
1809 /* we do not emit a warning in this case because unlinking cannot
1810 * be made MT safe.*/
1811 GST_OBJECT_UNLOCK (sinkpad);
1812 GST_OBJECT_UNLOCK (srcpad);
1813 return GST_PAD_LINK_WAS_LINKED;
1817 GST_CAT_INFO (GST_CAT_PADS, "pads have wrong hierarchy");
1818 GST_OBJECT_UNLOCK (sinkpad);
1819 GST_OBJECT_UNLOCK (srcpad);
1820 return GST_PAD_LINK_WRONG_HIERARCHY;
1824 GST_CAT_INFO (GST_CAT_PADS, "caps are incompatible");
1825 GST_OBJECT_UNLOCK (sinkpad);
1826 GST_OBJECT_UNLOCK (srcpad);
1827 return GST_PAD_LINK_NOFORMAT;
1833 * @srcpad: the source #GstPad to link.
1834 * @sinkpad: the sink #GstPad to link.
1836 * Links the source pad and the sink pad.
1838 * Returns: A result code indicating if the connection worked or
1844 gst_pad_link (GstPad * srcpad, GstPad * sinkpad)
1846 GstPadLinkReturn result;
1848 /* prepare will also lock the two pads */
1849 result = gst_pad_link_prepare (srcpad, sinkpad);
1851 if (result != GST_PAD_LINK_OK)
1852 goto prepare_failed;
1854 /* must set peers before calling the link function */
1855 GST_PAD_PEER (srcpad) = sinkpad;
1856 GST_PAD_PEER (sinkpad) = srcpad;
1858 GST_OBJECT_UNLOCK (sinkpad);
1859 GST_OBJECT_UNLOCK (srcpad);
1861 /* FIXME released the locks here, concurrent thread might link
1862 * something else. */
1863 if (GST_PAD_LINKFUNC (srcpad)) {
1864 /* this one will call the peer link function */
1865 result = GST_PAD_LINKFUNC (srcpad) (srcpad, sinkpad);
1866 } else if (GST_PAD_LINKFUNC (sinkpad)) {
1867 /* if no source link function, we need to call the sink link
1868 * function ourselves. */
1869 result = GST_PAD_LINKFUNC (sinkpad) (sinkpad, srcpad);
1871 result = GST_PAD_LINK_OK;
1874 GST_OBJECT_LOCK (srcpad);
1875 GST_OBJECT_LOCK (sinkpad);
1877 if (result == GST_PAD_LINK_OK) {
1878 GST_OBJECT_UNLOCK (sinkpad);
1879 GST_OBJECT_UNLOCK (srcpad);
1881 /* fire off a signal to each of the pads telling them
1882 * that they've been linked */
1883 g_signal_emit (G_OBJECT (srcpad), gst_pad_signals[PAD_LINKED], 0, sinkpad);
1884 g_signal_emit (G_OBJECT (sinkpad), gst_pad_signals[PAD_LINKED], 0, srcpad);
1886 GST_CAT_INFO (GST_CAT_PADS, "linked %s:%s and %s:%s, successful",
1887 GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (sinkpad));
1889 GST_CAT_INFO (GST_CAT_PADS, "link between %s:%s and %s:%s failed",
1890 GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (sinkpad));
1892 GST_PAD_PEER (srcpad) = NULL;
1893 GST_PAD_PEER (sinkpad) = NULL;
1895 GST_OBJECT_UNLOCK (sinkpad);
1896 GST_OBJECT_UNLOCK (srcpad);
1907 gst_pad_set_pad_template (GstPad * pad, GstPadTemplate * templ)
1909 GstPadTemplate **template_p;
1911 /* this function would need checks if it weren't static */
1913 GST_OBJECT_LOCK (pad);
1914 template_p = &pad->padtemplate;
1915 gst_object_replace ((GstObject **) template_p, (GstObject *) templ);
1916 GST_OBJECT_UNLOCK (pad);
1919 gst_pad_template_pad_created (templ, pad);
1923 * gst_pad_get_pad_template:
1926 * Gets the template for @pad.
1928 * Returns: the #GstPadTemplate from which this pad was instantiated, or %NULL
1929 * if this pad has no template.
1931 * FIXME: currently returns an unrefcounted padtemplate.
1934 gst_pad_get_pad_template (GstPad * pad)
1936 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
1938 return GST_PAD_PAD_TEMPLATE (pad);
1942 /* should be called with the pad LOCK held */
1943 /* refs the caps, so caller is responsible for getting it unreffed */
1945 gst_pad_get_caps_unlocked (GstPad * pad)
1947 GstCaps *result = NULL;
1949 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "get pad caps");
1951 if (GST_PAD_GETCAPSFUNC (pad)) {
1952 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
1953 "dispatching to pad getcaps function");
1955 GST_OBJECT_FLAG_SET (pad, GST_PAD_IN_GETCAPS);
1956 GST_OBJECT_UNLOCK (pad);
1957 result = GST_PAD_GETCAPSFUNC (pad) (pad);
1958 GST_OBJECT_LOCK (pad);
1959 GST_OBJECT_FLAG_UNSET (pad, GST_PAD_IN_GETCAPS);
1961 if (result == NULL) {
1962 g_critical ("pad %s:%s returned NULL caps from getcaps function",
1963 GST_DEBUG_PAD_NAME (pad));
1965 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
1966 "pad getcaps returned %" GST_PTR_FORMAT, result);
1967 #ifndef G_DISABLE_ASSERT
1968 /* check that the returned caps are a real subset of the template caps */
1969 if (GST_PAD_PAD_TEMPLATE (pad)) {
1970 const GstCaps *templ_caps =
1971 GST_PAD_TEMPLATE_CAPS (GST_PAD_PAD_TEMPLATE (pad));
1972 if (!gst_caps_is_subset (result, templ_caps)) {
1975 GST_CAT_ERROR_OBJECT (GST_CAT_CAPS, pad,
1976 "pad returned caps %" GST_PTR_FORMAT
1977 " which are not a real subset of its template caps %"
1978 GST_PTR_FORMAT, result, templ_caps);
1980 ("pad %s:%s returned caps which are not a real "
1981 "subset of its template caps", GST_DEBUG_PAD_NAME (pad));
1982 temp = gst_caps_intersect (templ_caps, result);
1983 gst_caps_unref (result);
1991 if (GST_PAD_PAD_TEMPLATE (pad)) {
1992 GstPadTemplate *templ = GST_PAD_PAD_TEMPLATE (pad);
1994 result = GST_PAD_TEMPLATE_CAPS (templ);
1995 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
1996 "using pad template %p with caps %p %" GST_PTR_FORMAT, templ, result,
1999 result = gst_caps_ref (result);
2002 if (GST_PAD_CAPS (pad)) {
2003 result = GST_PAD_CAPS (pad);
2005 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
2006 "using pad caps %p %" GST_PTR_FORMAT, result, result);
2008 result = gst_caps_ref (result);
2012 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "pad has no caps");
2013 result = gst_caps_new_empty ();
2021 * @pad: a #GstPad to get the capabilities of.
2023 * Gets the capabilities this pad can produce or consume.
2024 * Note that this method doesn't necessarily return the caps set by
2025 * gst_pad_set_caps() - use #GST_PAD_CAPS for that instead.
2026 * gst_pad_get_caps returns all possible caps a pad can operate with, using
2027 * the pad's get_caps function;
2028 * this returns the pad template caps if not explicitly set.
2030 * Returns: a newly allocated copy of the #GstCaps of this pad.
2035 gst_pad_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 pad caps");
2045 result = gst_pad_get_caps_unlocked (pad);
2046 GST_OBJECT_UNLOCK (pad);
2052 * gst_pad_peer_get_caps:
2053 * @pad: a #GstPad to get the peer capabilities of.
2055 * Gets the capabilities of the peer connected to this pad.
2057 * Returns: the #GstCaps of the peer pad. This function returns a new caps, so use
2058 * gst_caps_unref to get rid of it. this function returns NULL if there is no
2062 gst_pad_peer_get_caps (GstPad * pad)
2065 GstCaps *result = NULL;
2067 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2069 GST_OBJECT_LOCK (pad);
2071 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "get peer caps");
2073 peerpad = GST_PAD_PEER (pad);
2074 if (G_UNLIKELY (peerpad == NULL))
2077 gst_object_ref (peerpad);
2078 GST_OBJECT_UNLOCK (pad);
2080 result = gst_pad_get_caps (peerpad);
2082 gst_object_unref (peerpad);
2088 GST_OBJECT_UNLOCK (pad);
2094 fixate_value (GValue * dest, const GValue * src)
2096 if (G_VALUE_TYPE (src) == GST_TYPE_INT_RANGE) {
2097 g_value_init (dest, G_TYPE_INT);
2098 g_value_set_int (dest, gst_value_get_int_range_min (src));
2099 } else if (G_VALUE_TYPE (src) == GST_TYPE_DOUBLE_RANGE) {
2100 g_value_init (dest, G_TYPE_DOUBLE);
2101 g_value_set_double (dest, gst_value_get_double_range_min (src));
2102 } else if (G_VALUE_TYPE (src) == GST_TYPE_FRACTION_RANGE) {
2103 gst_value_init_and_copy (dest, gst_value_get_fraction_range_min (src));
2104 } else if (G_VALUE_TYPE (src) == GST_TYPE_LIST) {
2105 GValue temp = { 0 };
2107 gst_value_init_and_copy (&temp, gst_value_list_get_value (src, 0));
2108 if (!fixate_value (dest, &temp))
2109 gst_value_init_and_copy (dest, &temp);
2110 g_value_unset (&temp);
2111 } else if (G_VALUE_TYPE (src) == GST_TYPE_ARRAY) {
2112 gboolean res = FALSE;
2115 g_value_init (dest, GST_TYPE_ARRAY);
2116 for (n = 0; n < gst_value_array_get_size (src); n++) {
2118 const GValue *orig_kid = gst_value_array_get_value (src, n);
2120 if (!fixate_value (&kid, orig_kid))
2121 gst_value_init_and_copy (&kid, orig_kid);
2124 gst_value_array_append_value (dest, &kid);
2125 g_value_unset (&kid);
2129 g_value_unset (dest);
2140 gst_pad_default_fixate (GQuark field_id, const GValue * value, gpointer data)
2142 GstStructure *s = data;
2145 if (fixate_value (&v, value)) {
2146 gst_structure_id_set_value (s, field_id, &v);
2154 * gst_pad_fixate_caps:
2155 * @pad: a #GstPad to fixate
2156 * @caps: the #GstCaps to fixate
2158 * Fixate a caps on the given pad. Modifies the caps in place, so you should
2159 * make sure that the caps are actually writable (see gst_caps_make_writable()).
2162 gst_pad_fixate_caps (GstPad * pad, GstCaps * caps)
2164 GstPadFixateCapsFunction fixatefunc;
2167 g_return_if_fail (GST_IS_PAD (pad));
2168 g_return_if_fail (caps != NULL);
2170 if (gst_caps_is_fixed (caps))
2173 fixatefunc = GST_PAD_FIXATECAPSFUNC (pad);
2175 fixatefunc (pad, caps);
2178 /* default fixation */
2179 for (n = 0; n < gst_caps_get_size (caps); n++) {
2180 GstStructure *s = gst_caps_get_structure (caps, n);
2182 gst_structure_foreach (s, gst_pad_default_fixate, s);
2186 /* Default accept caps implementation just checks against
2187 * against the allowed caps for the pad */
2189 gst_pad_acceptcaps_default (GstPad * pad, GstCaps * caps)
2191 /* get the caps and see if it intersects to something
2195 gboolean result = FALSE;
2197 allowed = gst_pad_get_caps (pad);
2199 goto nothing_allowed;
2201 intersect = gst_caps_intersect (allowed, caps);
2203 result = !gst_caps_is_empty (intersect);
2205 GST_DEBUG_OBJECT (pad, "intersection gave empty caps");
2207 gst_caps_unref (allowed);
2208 gst_caps_unref (intersect);
2215 GST_DEBUG_OBJECT (pad, "no caps allowed on the pad");
2221 * gst_pad_accept_caps:
2222 * @pad: a #GstPad to check
2223 * @caps: a #GstCaps to check on the pad
2225 * Check if the given pad accepts the caps.
2227 * Returns: TRUE if the pad can accept the caps.
2230 gst_pad_accept_caps (GstPad * pad, GstCaps * caps)
2233 GstPadAcceptCapsFunction acceptfunc;
2234 GstCaps *existing = NULL;
2236 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2238 /* any pad can be unnegotiated */
2242 /* lock for checking the existing caps */
2243 GST_OBJECT_LOCK (pad);
2244 acceptfunc = GST_PAD_ACCEPTCAPSFUNC (pad);
2245 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "accept caps of %p", caps);
2246 /* The current caps on a pad are trivially acceptable */
2247 if (G_LIKELY ((existing = GST_PAD_CAPS (pad)))) {
2248 if (caps == existing || gst_caps_is_equal (caps, existing))
2251 GST_OBJECT_UNLOCK (pad);
2253 if (G_LIKELY (acceptfunc)) {
2254 /* we can call the function */
2255 result = acceptfunc (pad, caps);
2256 GST_DEBUG_OBJECT (pad, "acceptfunc returned %d", result);
2258 /* Only null if the element explicitly unset it */
2259 result = gst_pad_acceptcaps_default (pad, caps);
2260 GST_DEBUG_OBJECT (pad, "default acceptcaps returned %d", result);
2266 GST_DEBUG_OBJECT (pad, "pad had same caps");
2267 GST_OBJECT_UNLOCK (pad);
2273 * gst_pad_peer_accept_caps:
2274 * @pad: a #GstPad to check the peer of
2275 * @caps: a #GstCaps to check on the pad
2277 * Check if the peer of @pad accepts @caps. If @pad has no peer, this function
2280 * Returns: TRUE if the peer of @pad can accept the caps or @pad has no peer.
2283 gst_pad_peer_accept_caps (GstPad * pad, GstCaps * caps)
2288 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2290 GST_OBJECT_LOCK (pad);
2292 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "peer accept caps of (%p)", pad);
2294 peerpad = GST_PAD_PEER (pad);
2295 if (G_UNLIKELY (peerpad == NULL))
2298 result = gst_pad_accept_caps (peerpad, caps);
2299 GST_OBJECT_UNLOCK (pad);
2305 GST_OBJECT_UNLOCK (pad);
2312 * @pad: a #GstPad to set the capabilities of.
2313 * @caps: a #GstCaps to set.
2315 * Sets the capabilities of this pad. The caps must be fixed. Any previous
2316 * caps on the pad will be unreffed. This function refs the caps so you should
2317 * unref if as soon as you don't need it anymore.
2318 * It is possible to set NULL caps, which will make the pad unnegotiated
2321 * Returns: TRUE if the caps could be set. FALSE if the caps were not fixed
2322 * or bad parameters were provided to this function.
2327 gst_pad_set_caps (GstPad * pad, GstCaps * caps)
2329 GstPadSetCapsFunction setcaps;
2332 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2333 g_return_val_if_fail (caps == NULL || gst_caps_is_fixed (caps), FALSE);
2335 GST_OBJECT_LOCK (pad);
2336 existing = GST_PAD_CAPS (pad);
2337 if (existing == caps)
2340 if (gst_caps_is_equal (caps, existing))
2341 goto setting_same_caps;
2343 setcaps = GST_PAD_SETCAPSFUNC (pad);
2345 /* call setcaps function to configure the pad only if the
2346 * caps is not NULL */
2347 if (setcaps != NULL && caps) {
2348 if (!GST_PAD_IS_IN_SETCAPS (pad)) {
2349 GST_OBJECT_FLAG_SET (pad, GST_PAD_IN_SETCAPS);
2350 GST_OBJECT_UNLOCK (pad);
2351 if (!setcaps (pad, caps))
2353 GST_OBJECT_LOCK (pad);
2354 GST_OBJECT_FLAG_UNSET (pad, GST_PAD_IN_SETCAPS);
2356 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "pad was dispatching");
2360 gst_caps_replace (&GST_PAD_CAPS (pad), caps);
2361 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "caps %" GST_PTR_FORMAT, caps);
2362 GST_OBJECT_UNLOCK (pad);
2364 g_object_notify (G_OBJECT (pad), "caps");
2370 GST_OBJECT_UNLOCK (pad);
2375 gst_caps_replace (&GST_PAD_CAPS (pad), caps);
2376 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
2377 "caps %" GST_PTR_FORMAT " same as existing, updating ptr only", caps);
2378 GST_OBJECT_UNLOCK (pad);
2385 GST_OBJECT_LOCK (pad);
2386 GST_OBJECT_FLAG_UNSET (pad, GST_PAD_IN_SETCAPS);
2387 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
2388 "caps %" GST_PTR_FORMAT " could not be set", caps);
2389 GST_OBJECT_UNLOCK (pad);
2396 gst_pad_configure_sink (GstPad * pad, GstCaps * caps)
2398 GstPadSetCapsFunction setcaps;
2401 setcaps = GST_PAD_SETCAPSFUNC (pad);
2403 /* See if pad accepts the caps - only needed if
2404 * no setcaps function */
2405 if (setcaps == NULL)
2406 if (!gst_pad_accept_caps (pad, caps))
2409 /* set caps on pad if call succeeds */
2410 res = gst_pad_set_caps (pad, caps);
2411 /* no need to unref the caps here, set_caps takes a ref and
2412 * our ref goes away when we leave this function. */
2418 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
2419 "caps %" GST_PTR_FORMAT " not accepted", caps);
2424 /* returns TRUE if the src pad could be configured to accept the given caps */
2426 gst_pad_configure_src (GstPad * pad, GstCaps * caps, gboolean dosetcaps)
2428 GstPadSetCapsFunction setcaps;
2431 setcaps = GST_PAD_SETCAPSFUNC (pad);
2433 /* See if pad accepts the caps - only needed if
2434 * no setcaps function */
2435 if (setcaps == NULL)
2436 if (!gst_pad_accept_caps (pad, caps))
2440 res = gst_pad_set_caps (pad, caps);
2448 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
2449 "caps %" GST_PTR_FORMAT " not accepted", caps);
2455 * gst_pad_get_pad_template_caps:
2456 * @pad: a #GstPad to get the template capabilities from.
2458 * Gets the capabilities for @pad's template.
2460 * Returns: the #GstCaps of this pad template. If you intend to keep a reference
2461 * on the caps, make a copy (see gst_caps_copy ()).
2464 gst_pad_get_pad_template_caps (GstPad * pad)
2466 static GstStaticCaps anycaps = GST_STATIC_CAPS ("ANY");
2468 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2470 if (GST_PAD_PAD_TEMPLATE (pad))
2471 return GST_PAD_TEMPLATE_CAPS (GST_PAD_PAD_TEMPLATE (pad));
2473 return gst_static_caps_get (&anycaps);
2479 * @pad: a #GstPad to get the peer of.
2481 * Gets the peer of @pad. This function refs the peer pad so
2482 * you need to unref it after use.
2484 * Returns: the peer #GstPad. Unref after usage.
2489 gst_pad_get_peer (GstPad * pad)
2493 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2495 GST_OBJECT_LOCK (pad);
2496 result = GST_PAD_PEER (pad);
2498 gst_object_ref (result);
2499 GST_OBJECT_UNLOCK (pad);
2505 * gst_pad_get_allowed_caps:
2508 * Gets the capabilities of the allowed media types that can flow through
2509 * @pad and its peer.
2511 * The allowed capabilities is calculated as the intersection of the results of
2512 * calling gst_pad_get_caps() on @pad and its peer. The caller owns a reference
2513 * on the resulting caps.
2515 * Returns: the allowed #GstCaps of the pad link. Unref the caps when you no
2516 * longer need it. This function returns NULL when @pad has no peer.
2521 gst_pad_get_allowed_caps (GstPad * pad)
2528 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2530 GST_OBJECT_LOCK (pad);
2532 peer = GST_PAD_PEER (pad);
2533 if (G_UNLIKELY (peer == NULL))
2536 GST_CAT_DEBUG_OBJECT (GST_CAT_PROPERTIES, pad, "getting allowed caps");
2538 gst_object_ref (peer);
2539 GST_OBJECT_UNLOCK (pad);
2540 mycaps = gst_pad_get_caps (pad);
2542 peercaps = gst_pad_get_caps (peer);
2543 gst_object_unref (peer);
2545 caps = gst_caps_intersect (mycaps, peercaps);
2546 gst_caps_unref (peercaps);
2547 gst_caps_unref (mycaps);
2549 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "allowed caps %" GST_PTR_FORMAT,
2556 GST_CAT_DEBUG_OBJECT (GST_CAT_PROPERTIES, pad, "no peer");
2557 GST_OBJECT_UNLOCK (pad);
2564 * gst_pad_get_negotiated_caps:
2567 * Gets the capabilities of the media type that currently flows through @pad
2570 * This function can be used on both src and sinkpads. Note that srcpads are
2571 * always negotiated before sinkpads so it is possible that the negotiated caps
2572 * on the srcpad do not match the negotiated caps of the peer.
2574 * Returns: the negotiated #GstCaps of the pad link. Free the caps when
2575 * you no longer need it. This function returns NULL when the @pad has no
2576 * peer or is not negotiated yet.
2581 gst_pad_get_negotiated_caps (GstPad * pad)
2586 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2588 GST_OBJECT_LOCK (pad);
2590 if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
2593 GST_CAT_DEBUG_OBJECT (GST_CAT_PROPERTIES, pad, "getting negotiated caps");
2595 caps = GST_PAD_CAPS (pad);
2597 gst_caps_ref (caps);
2598 GST_OBJECT_UNLOCK (pad);
2600 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "negotiated caps %" GST_PTR_FORMAT,
2607 GST_CAT_DEBUG_OBJECT (GST_CAT_PROPERTIES, pad, "no peer");
2608 GST_OBJECT_UNLOCK (pad);
2614 /* calls the buffer_alloc function on the given pad */
2615 static GstFlowReturn
2616 gst_pad_buffer_alloc_unchecked (GstPad * pad, guint64 offset, gint size,
2617 GstCaps * caps, GstBuffer ** buf)
2620 GstPadBufferAllocFunction bufferallocfunc;
2622 GST_OBJECT_LOCK (pad);
2623 /* when the pad is flushing we cannot give a buffer */
2624 if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad)))
2627 bufferallocfunc = pad->bufferallocfunc;
2629 if (offset == GST_BUFFER_OFFSET_NONE) {
2630 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
2631 "calling bufferallocfunc &%s (@%p) for size %d offset NONE",
2632 GST_DEBUG_FUNCPTR_NAME (bufferallocfunc), bufferallocfunc, size);
2634 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
2635 "calling bufferallocfunc &%s (@%p) of for size %d offset %"
2636 G_GUINT64_FORMAT, GST_DEBUG_FUNCPTR_NAME (bufferallocfunc),
2637 bufferallocfunc, size, offset);
2639 GST_OBJECT_UNLOCK (pad);
2641 /* G_LIKELY for now since most elements don't implement a buffer alloc
2642 * function and there is no default alloc proxy function as this is usually
2644 if (G_LIKELY (bufferallocfunc == NULL))
2647 ret = bufferallocfunc (pad, offset, size, caps, buf);
2648 if (G_UNLIKELY (ret != GST_FLOW_OK))
2650 /* no error, but NULL buffer means fallback to the default */
2651 if (G_UNLIKELY (*buf == NULL))
2654 /* If the buffer alloc function didn't set up the caps like it should,
2656 if (G_UNLIKELY (caps && (GST_BUFFER_CAPS (*buf) == NULL))) {
2657 GST_WARNING_OBJECT (pad,
2658 "Buffer allocation function did not set caps. Setting");
2659 gst_buffer_set_caps (*buf, caps);
2665 /* pad was flushing */
2666 GST_OBJECT_UNLOCK (pad);
2667 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "pad was flushing");
2668 return GST_FLOW_WRONG_STATE;
2672 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
2673 "alloc function returned error (%d) %s", ret, gst_flow_get_name (ret));
2678 /* fallback case, allocate a buffer of our own, add pad caps. */
2679 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "fallback buffer alloc");
2681 *buf = gst_buffer_new_and_alloc (size);
2682 GST_BUFFER_OFFSET (*buf) = offset;
2683 gst_buffer_set_caps (*buf, caps);
2689 static GstFlowReturn
2690 gst_pad_alloc_buffer_full (GstPad * pad, guint64 offset, gint size,
2691 GstCaps * caps, GstBuffer ** buf, gboolean setcaps)
2695 gboolean caps_changed;
2697 g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
2698 g_return_val_if_fail (GST_PAD_IS_SRC (pad), GST_FLOW_ERROR);
2699 g_return_val_if_fail (buf != NULL, GST_FLOW_ERROR);
2701 GST_OBJECT_LOCK (pad);
2702 while (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad)))
2703 if ((ret = handle_pad_block (pad)) != GST_FLOW_OK)
2706 if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
2709 gst_object_ref (peer);
2710 GST_OBJECT_UNLOCK (pad);
2712 ret = gst_pad_buffer_alloc_unchecked (peer, offset, size, caps, buf);
2713 gst_object_unref (peer);
2715 if (G_UNLIKELY (ret != GST_FLOW_OK))
2718 /* FIXME, move capnego this into a base class? */
2719 caps = GST_BUFFER_CAPS (*buf);
2721 /* Lock for checking caps, pretty pointless as the _pad_push() function might
2722 * change it concurrently, one of the problems with automatic caps setting in
2723 * pad_alloc_and_set_caps. Worst case, if does a check too much, but only when
2724 * there is heavy renegotiation going on in both directions. */
2725 GST_OBJECT_LOCK (pad);
2726 caps_changed = caps && caps != GST_PAD_CAPS (pad);
2727 GST_OBJECT_UNLOCK (pad);
2729 /* we got a new datatype on the pad, see if it can handle it */
2730 if (G_UNLIKELY (caps_changed)) {
2731 GST_DEBUG_OBJECT (pad, "caps changed to %p %" GST_PTR_FORMAT, caps, caps);
2732 if (G_UNLIKELY (!gst_pad_configure_src (pad, caps, setcaps)))
2733 goto not_negotiated;
2739 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "pad block stopped by flush");
2740 GST_OBJECT_UNLOCK (pad);
2745 /* pad has no peer */
2746 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
2747 "called bufferallocfunc but had no peer");
2748 GST_OBJECT_UNLOCK (pad);
2749 return GST_FLOW_NOT_LINKED;
2753 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
2754 "alloc function returned error %s", gst_flow_get_name (ret));
2759 gst_buffer_unref (*buf);
2761 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
2762 "alloc function returned unacceptable buffer");
2763 return GST_FLOW_NOT_NEGOTIATED;
2768 * gst_pad_alloc_buffer:
2769 * @pad: a source #GstPad
2770 * @offset: the offset of the new buffer in the stream
2771 * @size: the size of the new buffer
2772 * @caps: the caps of the new buffer
2773 * @buf: a newly allocated buffer
2775 * Allocates a new, empty buffer optimized to push to pad @pad. This
2776 * function only works if @pad is a source pad and has a peer.
2778 * A new, empty #GstBuffer will be put in the @buf argument.
2779 * You need to check the caps of the buffer after performing this
2780 * function and renegotiate to the format if needed.
2782 * Returns: a result code indicating success of the operation. Any
2783 * result code other than #GST_FLOW_OK is an error and @buf should
2785 * An error can occur if the pad is not connected or when the downstream
2786 * peer elements cannot provide an acceptable buffer.
2791 gst_pad_alloc_buffer (GstPad * pad, guint64 offset, gint size, GstCaps * caps,
2794 return gst_pad_alloc_buffer_full (pad, offset, size, caps, buf, FALSE);
2798 * gst_pad_alloc_buffer_and_set_caps:
2799 * @pad: a source #GstPad
2800 * @offset: the offset of the new buffer in the stream
2801 * @size: the size of the new buffer
2802 * @caps: the caps of the new buffer
2803 * @buf: a newly allocated buffer
2805 * In addition to the function gst_pad_alloc_buffer(), this function
2806 * automatically calls gst_pad_set_caps() when the caps of the
2807 * newly allocated buffer are different from the @pad caps.
2809 * Returns: a result code indicating success of the operation. Any
2810 * result code other than #GST_FLOW_OK is an error and @buf should
2812 * An error can occur if the pad is not connected or when the downstream
2813 * peer elements cannot provide an acceptable buffer.
2818 gst_pad_alloc_buffer_and_set_caps (GstPad * pad, guint64 offset, gint size,
2819 GstCaps * caps, GstBuffer ** buf)
2821 return gst_pad_alloc_buffer_full (pad, offset, size, caps, buf, TRUE);
2825 * gst_pad_get_internal_links_default:
2826 * @pad: the #GstPad to get the internal links of.
2828 * Gets a list of pads to which the given pad is linked to
2829 * inside of the parent element.
2830 * This is the default handler, and thus returns a list of all of the
2831 * pads inside the parent element with opposite direction.
2832 * The caller must free this list after use.
2834 * Returns: a newly allocated #GList of pads, or NULL if the pad has no parent.
2839 gst_pad_get_internal_links_default (GstPad * pad)
2844 GstPadDirection direction;
2846 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2848 direction = pad->direction;
2850 parent = GST_PAD_PARENT (pad);
2854 parent_pads = parent->pads;
2856 while (parent_pads) {
2857 GstPad *parent_pad = GST_PAD_CAST (parent_pads->data);
2859 if (parent_pad->direction != direction) {
2860 GST_DEBUG_OBJECT (pad, "adding pad %s:%s",
2861 GST_DEBUG_PAD_NAME (parent_pad));
2862 res = g_list_prepend (res, parent_pad);
2864 parent_pads = g_list_next (parent_pads);
2870 GST_DEBUG_OBJECT (pad, "no parent");
2876 * gst_pad_get_internal_links:
2877 * @pad: the #GstPad to get the internal links of.
2879 * Gets a list of pads to which the given pad is linked to
2880 * inside of the parent element.
2881 * The caller must free this list after use.
2883 * Returns: a newly allocated #GList of pads.
2888 gst_pad_get_internal_links (GstPad * pad)
2892 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2894 if (GST_PAD_INTLINKFUNC (pad))
2895 res = GST_PAD_INTLINKFUNC (pad) (pad);
2902 gst_pad_event_default_dispatch (GstPad * pad, GstEvent * event)
2907 GST_INFO_OBJECT (pad, "Sending event %p (%s) to all internally linked pads",
2908 event, GST_EVENT_TYPE_NAME (event));
2910 result = (GST_PAD_DIRECTION (pad) == GST_PAD_SINK);
2912 orig = pads = gst_pad_get_internal_links (pad);
2915 GstPad *eventpad = GST_PAD_CAST (pads->data);
2917 pads = g_list_next (pads);
2919 if (GST_PAD_DIRECTION (eventpad) == GST_PAD_SRC) {
2920 /* for each pad we send to, we should ref the event; it's up
2921 * to downstream to unref again when handled. */
2922 GST_LOG_OBJECT (pad, "Reffing and sending event %p (%s) to %s:%s",
2923 event, GST_EVENT_TYPE_NAME (event), GST_DEBUG_PAD_NAME (eventpad));
2924 gst_event_ref (event);
2925 gst_pad_push_event (eventpad, event);
2927 /* we only send the event on one pad, multi-sinkpad elements
2928 * should implement a handler */
2929 GST_LOG_OBJECT (pad, "sending event %p (%s) to one sink pad %s:%s",
2930 event, GST_EVENT_TYPE_NAME (event), GST_DEBUG_PAD_NAME (eventpad));
2931 result = gst_pad_push_event (eventpad, event);
2935 /* we handled the incoming event so we unref once */
2936 GST_LOG_OBJECT (pad, "handled event %p, unreffing", event);
2937 gst_event_unref (event);
2946 * gst_pad_event_default:
2947 * @pad: a #GstPad to call the default event handler on.
2948 * @event: the #GstEvent to handle.
2950 * Invokes the default event handler for the given pad. End-of-stream and
2951 * discontinuity events are handled specially, and then the event is sent to all
2952 * pads internally linked to @pad. Note that if there are many possible sink
2953 * pads that are internally linked to @pad, only one will be sent an event.
2954 * Multi-sinkpad elements should implement custom event handlers.
2956 * Returns: TRUE if the event was sent succesfully.
2959 gst_pad_event_default (GstPad * pad, GstEvent * event)
2961 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2962 g_return_val_if_fail (event != NULL, FALSE);
2964 switch (GST_EVENT_TYPE (event)) {
2967 GST_DEBUG_OBJECT (pad, "pausing task because of eos");
2968 gst_pad_pause_task (pad);
2975 return gst_pad_event_default_dispatch (pad, event);
2979 * gst_pad_dispatcher:
2980 * @pad: a #GstPad to dispatch.
2981 * @dispatch: the #GstDispatcherFunction to call.
2982 * @data: gpointer user data passed to the dispatcher function.
2984 * Invokes the given dispatcher function on each respective peer of
2985 * all pads that are internally linked to the given pad.
2986 * The GstPadDispatcherFunction should return TRUE when no further pads
2987 * need to be processed.
2989 * Returns: TRUE if one of the dispatcher functions returned TRUE.
2992 gst_pad_dispatcher (GstPad * pad, GstPadDispatcherFunction dispatch,
2995 gboolean res = FALSE;
2996 GList *int_pads, *orig;
2998 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2999 g_return_val_if_fail (dispatch != NULL, FALSE);
3001 orig = int_pads = gst_pad_get_internal_links (pad);
3004 GstPad *int_pad = GST_PAD_CAST (int_pads->data);
3005 GstPad *int_peer = gst_pad_get_peer (int_pad);
3008 GST_DEBUG_OBJECT (int_pad, "dispatching to peer %s:%s",
3009 GST_DEBUG_PAD_NAME (int_peer));
3010 res = dispatch (int_peer, data);
3011 gst_object_unref (int_peer);
3015 GST_DEBUG_OBJECT (int_pad, "no peer");
3017 int_pads = g_list_next (int_pads);
3020 GST_DEBUG_OBJECT (pad, "done, result %d", res);
3027 * @pad: a #GstPad to invoke the default query on.
3028 * @query: the #GstQuery to perform.
3030 * Dispatches a query to a pad. The query should have been allocated by the
3031 * caller via one of the type-specific allocation functions in gstquery.h. The
3032 * element is responsible for filling the query with an appropriate response,
3033 * which should then be parsed with a type-specific query parsing function.
3035 * Again, the caller is responsible for both the allocation and deallocation of
3036 * the query structure.
3038 * Returns: TRUE if the query could be performed.
3041 gst_pad_query (GstPad * pad, GstQuery * query)
3043 GstPadQueryFunction func;
3045 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
3046 g_return_val_if_fail (GST_IS_QUERY (query), FALSE);
3048 GST_DEBUG_OBJECT (pad, "sending query %p", query);
3050 if ((func = GST_PAD_QUERYFUNC (pad)) == NULL)
3053 return func (pad, query);
3057 GST_DEBUG_OBJECT (pad, "had no query function");
3063 * gst_pad_query_default:
3064 * @pad: a #GstPad to call the default query handler on.
3065 * @query: the #GstQuery to handle.
3067 * Invokes the default query handler for the given pad.
3068 * The query is sent to all pads internally linked to @pad. Note that
3069 * if there are many possible sink pads that are internally linked to
3070 * @pad, only one will be sent the query.
3071 * Multi-sinkpad elements should implement custom query handlers.
3073 * Returns: TRUE if the query was performed succesfully.
3076 gst_pad_query_default (GstPad * pad, GstQuery * query)
3078 switch (GST_QUERY_TYPE (query)) {
3079 case GST_QUERY_POSITION:
3080 case GST_QUERY_SEEKING:
3081 case GST_QUERY_FORMATS:
3082 case GST_QUERY_LATENCY:
3083 case GST_QUERY_JITTER:
3084 case GST_QUERY_RATE:
3085 case GST_QUERY_CONVERT:
3087 return gst_pad_dispatcher
3088 (pad, (GstPadDispatcherFunction) gst_pad_query, query);
3092 #ifndef GST_DISABLE_LOADSAVE
3093 /* FIXME: why isn't this on a GstElement ? */
3095 * gst_pad_load_and_link:
3096 * @self: an #xmlNodePtr to read the description from.
3097 * @parent: the #GstObject element that owns the pad.
3099 * Reads the pad definition from the XML node and links the given pad
3100 * in the element to a pad of an element up in the hierarchy.
3103 gst_pad_load_and_link (xmlNodePtr self, GstObject * parent)
3105 xmlNodePtr field = self->xmlChildrenNode;
3106 GstPad *pad = NULL, *targetpad;
3110 GstObject *grandparent;
3114 if (!strcmp ((char *) field->name, "name")) {
3115 name = (gchar *) xmlNodeGetContent (field);
3116 pad = gst_element_get_pad (GST_ELEMENT (parent), name);
3118 } else if (!strcmp ((char *) field->name, "peer")) {
3119 peer = (gchar *) xmlNodeGetContent (field);
3121 field = field->next;
3123 g_return_if_fail (pad != NULL);
3128 split = g_strsplit (peer, ".", 2);
3130 if (split[0] == NULL || split[1] == NULL) {
3131 GST_CAT_DEBUG_OBJECT (GST_CAT_XML, pad,
3132 "Could not parse peer '%s', leaving unlinked", peer);
3139 g_return_if_fail (split[0] != NULL);
3140 g_return_if_fail (split[1] != NULL);
3142 grandparent = gst_object_get_parent (parent);
3144 if (grandparent && GST_IS_BIN (grandparent)) {
3145 target = gst_bin_get_by_name_recurse_up (GST_BIN (grandparent), split[0]);
3152 targetpad = gst_element_get_pad (target, split[1]);
3154 if (targetpad == NULL)
3157 gst_pad_link (pad, targetpad);
3164 * gst_pad_save_thyself:
3165 * @pad: a #GstPad to save.
3166 * @parent: the parent #xmlNodePtr to save the description in.
3168 * Saves the pad into an xml representation.
3170 * Returns: the #xmlNodePtr representation of the pad.
3173 gst_pad_save_thyself (GstObject * object, xmlNodePtr parent)
3178 g_return_val_if_fail (GST_IS_PAD (object), NULL);
3180 pad = GST_PAD (object);
3182 xmlNewChild (parent, NULL, (xmlChar *) "name",
3183 (xmlChar *) GST_PAD_NAME (pad));
3185 if (GST_PAD_IS_SRC (pad)) {
3186 xmlNewChild (parent, NULL, (xmlChar *) "direction", (xmlChar *) "source");
3187 } else if (GST_PAD_IS_SINK (pad)) {
3188 xmlNewChild (parent, NULL, (xmlChar *) "direction", (xmlChar *) "sink");
3190 xmlNewChild (parent, NULL, (xmlChar *) "direction", (xmlChar *) "unknown");
3193 if (GST_PAD_PEER (pad) != NULL) {
3196 peer = GST_PAD_PEER (pad);
3197 /* first check to see if the peer's parent's parent is the same */
3198 /* we just save it off */
3199 content = g_strdup_printf ("%s.%s",
3200 GST_OBJECT_NAME (GST_PAD_PARENT (peer)), GST_PAD_NAME (peer));
3201 xmlNewChild (parent, NULL, (xmlChar *) "peer", (xmlChar *) content);
3204 xmlNewChild (parent, NULL, (xmlChar *) "peer", NULL);
3211 * gst_ghost_pad_save_thyself:
3212 * @pad: a ghost #GstPad to save.
3213 * @parent: the parent #xmlNodePtr to save the description in.
3215 * Saves the ghost pad into an xml representation.
3217 * Returns: the #xmlNodePtr representation of the pad.
3220 gst_ghost_pad_save_thyself (GstPad * pad, xmlNodePtr parent)
3224 g_return_val_if_fail (GST_IS_GHOST_PAD (pad), NULL);
3226 self = xmlNewChild (parent, NULL, (xmlChar *) "ghostpad", NULL);
3227 xmlNewChild (self, NULL, (xmlChar *) "name", (xmlChar *) GST_PAD_NAME (pad));
3228 xmlNewChild (self, NULL, (xmlChar *) "parent",
3229 (xmlChar *) GST_OBJECT_NAME (GST_PAD_PARENT (pad)));
3231 /* FIXME FIXME FIXME! */
3236 #endif /* GST_DISABLE_LOADSAVE */
3239 * should be called with pad OBJECT_LOCK and STREAM_LOCK held.
3240 * GST_PAD_IS_BLOCKED (pad) == TRUE when this function is
3243 * This function perform the pad blocking when an event, buffer push
3244 * or buffer_alloc is performed on a _SRC_ pad. It blocks the
3245 * streaming thread after informing the pad has been blocked.
3247 * An application can with this method wait and block any streaming
3248 * thread and perform operations such as seeking or linking.
3250 * Two methods are available for notifying the application of the
3252 * - the callback method, which happens in the STREAMING thread with
3253 * the STREAM_LOCK held. With this method, the most usefull way of
3254 * dealing with the callback is to post a message to the main thread
3255 * where the pad block can then be handled outside of the streaming
3256 * thread. With the last method one can perform all operations such
3257 * as doing a state change, linking, unblocking, seeking etc on the
3259 * - the GCond signal method, which makes any thread unblock when
3260 * the pad block happens.
3262 * During the actual blocking state, the GST_PAD_BLOCKING flag is set.
3263 * The GST_PAD_BLOCKING flag is unset when the pad was unblocked.
3267 static GstFlowReturn
3268 handle_pad_block (GstPad * pad)
3270 GstPadBlockCallback callback;
3272 GstFlowReturn ret = GST_FLOW_OK;
3274 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "signal block taken");
3276 /* flushing, don't bother trying to block and return WRONG_STATE
3278 if (GST_PAD_IS_FLUSHING (pad))
3279 goto flushingnonref;
3281 /* we grab an extra ref for the callbacks, this is probably not
3282 * needed (callback code does not have a ref and cannot unref). I
3283 * think this was done to make it possible to unref the element in
3284 * the callback, which is in the end totally impossible as it
3285 * requires grabbing the STREAM_LOCK and OBJECT_LOCK which are
3286 * all taken when calling this function. */
3287 gst_object_ref (pad);
3289 /* we either have a callback installed to notify the block or
3290 * some other thread is doing a GCond wait. */
3291 callback = pad->block_callback;
3293 /* there is a callback installed, call it. We release the
3294 * lock so that the callback can do something usefull with the
3296 user_data = pad->block_data;
3297 GST_OBJECT_UNLOCK (pad);
3298 callback (pad, TRUE, user_data);
3299 GST_OBJECT_LOCK (pad);
3301 /* we released the lock, recheck flushing */
3302 if (GST_PAD_IS_FLUSHING (pad))
3305 /* no callback, signal the thread that is doing a GCond wait
3307 GST_PAD_BLOCK_BROADCAST (pad);
3310 /* OBJECT_LOCK could have been released when we did the callback, which
3311 * then could have made the pad unblock so we need to check the blocking
3312 * condition again. */
3313 while (GST_PAD_IS_BLOCKED (pad)) {
3314 /* now we block the streaming thread. It can be unlocked when we
3315 * deactivate the pad (which will also set the FLUSHING flag) or
3316 * when the pad is unblocked. A flushing event will also unblock
3317 * the pad after setting the FLUSHING flag. */
3318 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3319 "Waiting to be unblocked or set flushing");
3320 GST_OBJECT_FLAG_SET (pad, GST_PAD_BLOCKING);
3321 GST_PAD_BLOCK_WAIT (pad);
3322 GST_OBJECT_FLAG_UNSET (pad, GST_PAD_BLOCKING);
3324 /* see if we got unblocked by a flush or not */
3325 if (GST_PAD_IS_FLUSHING (pad))
3329 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "got unblocked");
3331 /* when we get here, the pad is unblocked again and we perform
3332 * the needed unblock code. */
3333 callback = pad->block_callback;
3335 /* we need to call the callback */
3336 user_data = pad->block_data;
3337 GST_OBJECT_UNLOCK (pad);
3338 callback (pad, FALSE, user_data);
3339 GST_OBJECT_LOCK (pad);
3341 /* we need to signal the thread waiting on the GCond */
3342 GST_PAD_BLOCK_BROADCAST (pad);
3345 gst_object_unref (pad);
3351 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "pad was flushing");
3352 return GST_FLOW_WRONG_STATE;
3356 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "pad became flushing");
3357 gst_object_unref (pad);
3358 return GST_FLOW_WRONG_STATE;
3362 /**********************************************************************
3363 * Data passing functions
3367 gst_pad_emit_have_data_signal (GstPad * pad, GstMiniObject * obj)
3370 GValue args[2] = { {0}, {0} };
3375 g_value_init (&ret, G_TYPE_BOOLEAN);
3376 g_value_set_boolean (&ret, TRUE);
3377 g_value_init (&args[0], GST_TYPE_PAD);
3378 g_value_set_object (&args[0], pad);
3379 g_value_init (&args[1], GST_TYPE_MINI_OBJECT); // G_TYPE_POINTER);
3380 gst_value_set_mini_object (&args[1], obj);
3382 if (GST_IS_EVENT (obj))
3383 detail = event_quark;
3385 detail = buffer_quark;
3388 g_signal_emitv (args, gst_pad_signals[PAD_HAVE_DATA], detail, &ret);
3389 res = g_value_get_boolean (&ret);
3392 g_value_unset (&ret);
3393 g_value_unset (&args[0]);
3394 g_value_unset (&args[1]);
3399 /* this is the chain function that does not perform the additional argument
3400 * checking for that little extra speed.
3402 static inline GstFlowReturn
3403 gst_pad_chain_unchecked (GstPad * pad, GstBuffer * buffer)
3406 gboolean caps_changed;
3407 GstPadChainFunction chainfunc;
3409 gboolean emit_signal;
3411 GST_PAD_STREAM_LOCK (pad);
3413 GST_OBJECT_LOCK (pad);
3414 if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad)))
3417 caps = GST_BUFFER_CAPS (buffer);
3418 caps_changed = caps && caps != GST_PAD_CAPS (pad);
3420 emit_signal = GST_PAD_DO_BUFFER_SIGNALS (pad) > 0;
3421 GST_OBJECT_UNLOCK (pad);
3423 /* see if the signal should be emited, we emit before caps nego as
3424 * we might drop the buffer and do capsnego for nothing. */
3425 if (G_UNLIKELY (emit_signal)) {
3426 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (buffer)))
3430 /* we got a new datatype on the pad, see if it can handle it */
3431 if (G_UNLIKELY (caps_changed)) {
3432 GST_DEBUG_OBJECT (pad, "caps changed to %p %" GST_PTR_FORMAT, caps, caps);
3433 if (G_UNLIKELY (!gst_pad_configure_sink (pad, caps)))
3434 goto not_negotiated;
3437 /* NOTE: we read the chainfunc unlocked.
3438 * we cannot hold the lock for the pad so we might send
3439 * the data to the wrong function. This is not really a
3440 * problem since functions are assigned at creation time
3441 * and don't change that often... */
3442 if (G_UNLIKELY ((chainfunc = GST_PAD_CHAINFUNC (pad)) == NULL))
3445 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3446 "calling chainfunction &%s", GST_DEBUG_FUNCPTR_NAME (chainfunc));
3448 ret = chainfunc (pad, buffer);
3450 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3451 "called chainfunction &%s, returned %s",
3452 GST_DEBUG_FUNCPTR_NAME (chainfunc), gst_flow_get_name (ret));
3454 GST_PAD_STREAM_UNLOCK (pad);
3461 gst_buffer_unref (buffer);
3462 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3463 "pushing, but pad was flushing");
3464 GST_OBJECT_UNLOCK (pad);
3465 GST_PAD_STREAM_UNLOCK (pad);
3466 return GST_FLOW_WRONG_STATE;
3470 gst_buffer_unref (buffer);
3471 GST_DEBUG_OBJECT (pad, "Dropping buffer due to FALSE probe return");
3472 GST_PAD_STREAM_UNLOCK (pad);
3477 gst_buffer_unref (buffer);
3478 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3479 "pushing buffer but pad did not accept");
3480 GST_PAD_STREAM_UNLOCK (pad);
3481 return GST_FLOW_NOT_NEGOTIATED;
3485 gst_buffer_unref (buffer);
3486 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3487 "pushing, but not chainhandler");
3488 GST_ELEMENT_ERROR (GST_PAD_PARENT (pad), CORE, PAD, (NULL),
3489 ("push on pad %s:%s but it has no chainfunction",
3490 GST_DEBUG_PAD_NAME (pad)));
3491 GST_PAD_STREAM_UNLOCK (pad);
3492 return GST_FLOW_NOT_SUPPORTED;
3498 * @pad: a sink #GstPad, returns GST_FLOW_ERROR if not.
3499 * @buffer: the #GstBuffer to send, return GST_FLOW_ERROR if not.
3501 * Chain a buffer to @pad.
3503 * The function returns #GST_FLOW_WRONG_STATE if the pad was flushing.
3505 * If the caps on @buffer are different from the current caps on @pad, this
3506 * function will call any setcaps function (see gst_pad_set_setcaps_function())
3507 * installed on @pad. If the new caps are not acceptable for @pad, this function
3508 * returns #GST_FLOW_NOT_NEGOTIATED.
3510 * The function proceeds calling the chain function installed on @pad (see
3511 * gst_pad_set_chain_function()) and the return value of that function is
3512 * returned to the caller. #GST_FLOW_NOT_SUPPORTED is returned if @pad has no
3515 * In all cases, success or failure, the caller loses its reference to @buffer
3516 * after calling this function.
3518 * Returns: a #GstFlowReturn from the pad.
3523 gst_pad_chain (GstPad * pad, GstBuffer * buffer)
3525 g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
3526 g_return_val_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SINK,
3528 g_return_val_if_fail (GST_IS_BUFFER (buffer), GST_FLOW_ERROR);
3530 return gst_pad_chain_unchecked (pad, buffer);
3535 * @pad: a source #GstPad, returns #GST_FLOW_ERROR if not.
3536 * @buffer: the #GstBuffer to push returns GST_FLOW_ERROR if not.
3538 * Pushes a buffer to the peer of @pad.
3540 * This function will call an installed pad block before triggering any
3541 * installed pad probes.
3543 * If the caps on @buffer are different from the currently configured caps on
3544 * @pad, this function will call any installed setcaps function on @pad (see
3545 * gst_pad_set_setcaps_function()). In case of failure to renegotiate the new
3546 * format, this function returns #GST_FLOW_NOT_NEGOTIATED.
3548 * The function proceeds calling gst_pad_chain() on the peer pad and returns the
3549 * value from that function. If @pad has no peer, #GST_FLOW_NOT_LINKED will be
3552 * In all cases, success or failure, the caller loses its reference to @buffer
3553 * after calling this function.
3555 * Returns: a #GstFlowReturn from the peer pad.
3560 gst_pad_push (GstPad * pad, GstBuffer * buffer)
3566 gboolean caps_changed;
3568 g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
3569 g_return_val_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SRC, GST_FLOW_ERROR);
3570 g_return_val_if_fail (GST_IS_BUFFER (buffer), GST_FLOW_ERROR);
3572 GST_OBJECT_LOCK (pad);
3574 /* FIXME: this check can go away; pad_set_blocked could be implemented with
3575 * probes completely or probes with an extended pad block. */
3576 while (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad)))
3577 if ((ret = handle_pad_block (pad)) != GST_FLOW_OK)
3580 /* we emit signals on the pad arg, the peer will have a chance to
3581 * emit in the _chain() function */
3582 if (G_UNLIKELY (GST_PAD_DO_BUFFER_SIGNALS (pad) > 0)) {
3583 /* unlock before emitting */
3584 GST_OBJECT_UNLOCK (pad);
3586 /* if the signal handler returned FALSE, it means we should just drop the
3588 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (buffer)))
3591 GST_OBJECT_LOCK (pad);
3594 if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
3597 /* take ref to peer pad before releasing the lock */
3598 gst_object_ref (peer);
3600 /* Before pushing the buffer to the peer pad, ensure that caps
3601 * are set on this pad */
3602 caps = GST_BUFFER_CAPS (buffer);
3603 caps_changed = caps && caps != GST_PAD_CAPS (pad);
3605 GST_OBJECT_UNLOCK (pad);
3607 /* we got a new datatype from the pad, it had better handle it */
3608 if (G_UNLIKELY (caps_changed)) {
3609 GST_DEBUG_OBJECT (pad, "caps changed to %p %" GST_PTR_FORMAT, caps, caps);
3610 if (G_UNLIKELY (!gst_pad_configure_src (pad, caps, TRUE)))
3611 goto not_negotiated;
3614 ret = gst_pad_chain_unchecked (peer, buffer);
3616 gst_object_unref (peer);
3620 /* ERROR recovery here */
3623 gst_buffer_unref (buffer);
3624 GST_DEBUG_OBJECT (pad, "pad block stopped by flush");
3625 GST_OBJECT_UNLOCK (pad);
3630 gst_buffer_unref (buffer);
3631 GST_DEBUG_OBJECT (pad, "Dropping buffer due to FALSE probe return");
3636 gst_buffer_unref (buffer);
3637 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3638 "pushing, but it was not linked");
3639 GST_OBJECT_UNLOCK (pad);
3640 return GST_FLOW_NOT_LINKED;
3644 gst_buffer_unref (buffer);
3645 gst_object_unref (peer);
3646 GST_CAT_DEBUG_OBJECT (GST_CAT_SCHEDULING, pad,
3647 "element pushed buffer then refused to accept the caps");
3648 return GST_FLOW_NOT_NEGOTIATED;
3653 * gst_pad_check_pull_range:
3654 * @pad: a sink #GstPad.
3656 * Checks if a gst_pad_pull_range() can be performed on the peer
3657 * source pad. This function is used by plugins that want to check
3658 * if they can use random access on the peer source pad.
3660 * The peer sourcepad can implement a custom #GstPadCheckGetRangeFunction
3661 * if it needs to perform some logic to determine if pull_range is
3664 * Returns: a gboolean with the result.
3669 gst_pad_check_pull_range (GstPad * pad)
3673 GstPadCheckGetRangeFunction checkgetrangefunc;
3675 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
3677 GST_OBJECT_LOCK (pad);
3678 if (GST_PAD_DIRECTION (pad) != GST_PAD_SINK)
3679 goto wrong_direction;
3681 if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
3684 gst_object_ref (peer);
3685 GST_OBJECT_UNLOCK (pad);
3687 /* see note in above function */
3688 if (G_LIKELY ((checkgetrangefunc = peer->checkgetrangefunc) == NULL)) {
3689 /* FIXME, kindoff ghetto */
3690 ret = GST_PAD_GETRANGEFUNC (peer) != NULL;
3691 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3692 "no checkgetrangefunc, assuming %d", ret);
3694 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3695 "calling checkgetrangefunc %s of peer pad %s:%s",
3696 GST_DEBUG_FUNCPTR_NAME (checkgetrangefunc), GST_DEBUG_PAD_NAME (peer));
3698 ret = checkgetrangefunc (peer);
3701 gst_object_unref (peer);
3705 /* ERROR recovery here */
3708 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3709 "checking pull range, but pad must be a sinkpad");
3710 GST_OBJECT_UNLOCK (pad);
3715 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3716 "checking pull range, but it was not linked");
3717 GST_OBJECT_UNLOCK (pad);
3723 * gst_pad_get_range:
3724 * @pad: a src #GstPad, returns #GST_FLOW_ERROR if not.
3725 * @offset: The start offset of the buffer
3726 * @size: The length of the buffer
3727 * @buffer: a pointer to hold the #GstBuffer, returns #GST_FLOW_ERROR if %NULL.
3729 * When @pad is flushing this function returns #GST_FLOW_WRONG_STATE
3732 * Calls the getrange function of @pad, see #GstPadGetRangeFunction for a
3733 * description of a getrange function. If @pad has no getrange function
3734 * installed (see gst_pad_set_getrange_function()) this function returns
3735 * #GST_FLOW_NOT_SUPPORTED.
3737 * @buffer's caps must either be unset or the same as what is already configured
3738 * on @pad. Renegotiation within a running pull-mode pipeline is not supported.
3740 * Returns: a #GstFlowReturn from the pad.
3745 gst_pad_get_range (GstPad * pad, guint64 offset, guint size,
3746 GstBuffer ** buffer)
3749 GstPadGetRangeFunction getrangefunc;
3750 gboolean emit_signal;
3752 g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
3753 g_return_val_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SRC, GST_FLOW_ERROR);
3754 g_return_val_if_fail (buffer != NULL, GST_FLOW_ERROR);
3756 GST_PAD_STREAM_LOCK (pad);
3758 GST_OBJECT_LOCK (pad);
3759 if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad)))
3762 emit_signal = GST_PAD_DO_BUFFER_SIGNALS (pad) > 0;
3763 GST_OBJECT_UNLOCK (pad);
3765 if (G_UNLIKELY ((getrangefunc = GST_PAD_GETRANGEFUNC (pad)) == NULL))
3768 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3769 "calling getrangefunc %s, offset %"
3770 G_GUINT64_FORMAT ", size %u",
3771 GST_DEBUG_FUNCPTR_NAME (getrangefunc), offset, size);
3773 ret = getrangefunc (pad, offset, size, buffer);
3775 /* can only fire the signal if we have a valid buffer */
3776 if (G_UNLIKELY (emit_signal) && (ret == GST_FLOW_OK)) {
3777 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (*buffer)))
3781 GST_PAD_STREAM_UNLOCK (pad);
3783 if (G_LIKELY (ret == GST_FLOW_OK)) {
3785 gboolean caps_changed;
3787 GST_OBJECT_LOCK (pad);
3788 /* Before pushing the buffer to the peer pad, ensure that caps
3789 * are set on this pad */
3790 caps = GST_BUFFER_CAPS (*buffer);
3791 caps_changed = caps && caps != GST_PAD_CAPS (pad);
3792 GST_OBJECT_UNLOCK (pad);
3794 /* we got a new datatype from the pad not supported in a running pull-mode
3796 if (G_UNLIKELY (caps_changed))
3797 goto not_negotiated;
3805 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3806 "pulling range, but pad was flushing");
3807 GST_OBJECT_UNLOCK (pad);
3808 GST_PAD_STREAM_UNLOCK (pad);
3809 return GST_FLOW_WRONG_STATE;
3813 GST_ELEMENT_ERROR (GST_PAD_PARENT (pad), CORE, PAD, (NULL),
3814 ("pullrange on pad %s:%s but it has no getrangefunction",
3815 GST_DEBUG_PAD_NAME (pad)));
3816 GST_PAD_STREAM_UNLOCK (pad);
3817 return GST_FLOW_NOT_SUPPORTED;
3821 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3822 "Dropping data after FALSE probe return");
3823 GST_PAD_STREAM_UNLOCK (pad);
3824 gst_buffer_unref (*buffer);
3826 return GST_FLOW_UNEXPECTED;
3830 /* ideally we want to use the commented-out code, but currently demuxers and
3831 * typefind do not follow part-negotiation.txt. When switching into pull
3832 * mode, typefind should probably return the found caps from getcaps(), and
3833 * demuxers should do the setcaps(). */
3836 gst_buffer_unref (*buffer);
3838 GST_CAT_WARNING_OBJECT (GST_CAT_SCHEDULING, pad,
3839 "getrange returned buffer of different caps");
3840 return GST_FLOW_NOT_NEGOTIATED;
3842 GST_CAT_DEBUG_OBJECT (GST_CAT_SCHEDULING, pad,
3843 "getrange returned buffer of different caps");
3850 * gst_pad_pull_range:
3851 * @pad: a sink #GstPad, returns GST_FLOW_ERROR if not.
3852 * @offset: The start offset of the buffer
3853 * @size: The length of the buffer
3854 * @buffer: a pointer to hold the #GstBuffer, returns GST_FLOW_ERROR if %NULL.
3856 * Pulls a buffer from the peer pad.
3858 * This function will first trigger the pad block signal if it was
3861 * When @pad is not linked #GST_FLOW_NOT_LINKED is returned else this
3862 * function returns the result of gst_pad_get_range() on the peer pad.
3863 * See gst_pad_get_range() for a list of return values and for the
3864 * semantics of the arguments of this function.
3866 * @buffer's caps must either be unset or the same as what is already configured
3867 * on @pad. Renegotiation within a running pull-mode pipeline is not supported.
3869 * Returns: a #GstFlowReturn from the peer pad.
3870 * When this function returns #GST_FLOW_OK, @buffer will contain a valid
3871 * #GstBuffer that should be freed with gst_buffer_unref() after usage.
3872 * @buffer may not be used or freed when any other return value than
3873 * #GST_FLOW_OK is returned.
3878 gst_pad_pull_range (GstPad * pad, guint64 offset, guint size,
3879 GstBuffer ** buffer)
3883 gboolean emit_signal;
3885 g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
3886 g_return_val_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SINK,
3888 g_return_val_if_fail (buffer != NULL, GST_FLOW_ERROR);
3890 GST_OBJECT_LOCK (pad);
3892 while (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad)))
3893 handle_pad_block (pad);
3895 if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
3898 /* signal emision for the pad, peer has chance to emit when
3899 * we call _get_range() */
3900 emit_signal = GST_PAD_DO_BUFFER_SIGNALS (pad) > 0;
3902 gst_object_ref (peer);
3903 GST_OBJECT_UNLOCK (pad);
3905 ret = gst_pad_get_range (peer, offset, size, buffer);
3907 gst_object_unref (peer);
3909 /* can only fire the signal if we have a valid buffer */
3910 if (G_UNLIKELY (emit_signal) && (ret == GST_FLOW_OK)) {
3911 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (*buffer)))
3915 if (G_LIKELY (ret == GST_FLOW_OK)) {
3917 gboolean caps_changed;
3919 GST_OBJECT_LOCK (pad);
3920 /* Before pushing the buffer to the peer pad, ensure that caps
3921 * are set on this pad */
3922 caps = GST_BUFFER_CAPS (*buffer);
3923 caps_changed = caps && caps != GST_PAD_CAPS (pad);
3924 GST_OBJECT_UNLOCK (pad);
3926 /* we got a new datatype on the pad, see if it can handle it */
3927 if (G_UNLIKELY (caps_changed))
3928 goto not_negotiated;
3933 /* ERROR recovery here */
3936 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3937 "pulling range, but it was not linked");
3938 GST_OBJECT_UNLOCK (pad);
3939 return GST_FLOW_NOT_LINKED;
3943 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3944 "Dropping data after FALSE probe return");
3945 gst_buffer_unref (*buffer);
3947 return GST_FLOW_UNEXPECTED;
3951 /* ideally we want to use the commented-out code, but currently demuxers and
3952 * typefind do not follow part-negotiation.txt. When switching into pull
3953 * mode, typefind should probably return the found caps from getcaps(), and
3954 * demuxers should do the setcaps(). */
3957 gst_buffer_unref (*buffer);
3959 GST_CAT_WARNING_OBJECT (GST_CAT_SCHEDULING, pad,
3960 "pullrange returned buffer of different caps");
3961 return GST_FLOW_NOT_NEGOTIATED;
3963 GST_CAT_DEBUG_OBJECT (GST_CAT_SCHEDULING, pad,
3964 "pullrange returned buffer of different caps");
3970 * gst_pad_push_event:
3971 * @pad: a #GstPad to push the event to.
3972 * @event: the #GstEvent to send to the pad.
3974 * Sends the event to the peer of the given pad. This function is
3975 * mainly used by elements to send events to their peer
3978 * This function takes owership of the provided event so you should
3979 * gst_event_ref() it if you want to reuse the event after this call.
3981 * Returns: TRUE if the event was handled.
3986 gst_pad_push_event (GstPad * pad, GstEvent * event)
3991 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
3992 g_return_val_if_fail (event != NULL, FALSE);
3993 g_return_val_if_fail (GST_IS_EVENT (event), FALSE);
3995 GST_LOG_OBJECT (pad, "event: %s", GST_EVENT_TYPE_NAME (event));
3997 GST_OBJECT_LOCK (pad);
3999 /* Two checks to be made:
4000 * . (un)set the FLUSHING flag for flushing events,
4001 * . handle pad blocking */
4002 switch (GST_EVENT_TYPE (event)) {
4003 case GST_EVENT_FLUSH_START:
4004 GST_PAD_SET_FLUSHING (pad);
4006 if (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad))) {
4007 /* flush start will have set the FLUSHING flag and will then
4008 * unlock all threads doing a GCond wait on the blocking pad. This
4009 * will typically unblock the STREAMING thread blocked on a pad. */
4010 GST_LOG_OBJECT (pad, "Pad is blocked, not forwarding flush-start, "
4011 "doing block signal.");
4012 GST_PAD_BLOCK_BROADCAST (pad);
4016 case GST_EVENT_FLUSH_STOP:
4017 GST_PAD_UNSET_FLUSHING (pad);
4019 /* if we are blocked, flush away the FLUSH_STOP event */
4020 if (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad))) {
4021 GST_LOG_OBJECT (pad, "Pad is blocked, not forwarding flush-stop");
4026 while (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad))) {
4027 /* block the event as long as the pad is blocked */
4028 if (handle_pad_block (pad) != GST_FLOW_OK)
4034 if (G_UNLIKELY (GST_PAD_DO_EVENT_SIGNALS (pad) > 0)) {
4035 GST_OBJECT_UNLOCK (pad);
4037 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (event)))
4040 GST_OBJECT_LOCK (pad);
4042 peerpad = GST_PAD_PEER (pad);
4043 if (peerpad == NULL)
4046 GST_LOG_OBJECT (pad, "sending event %s to peerpad %" GST_PTR_FORMAT,
4047 GST_EVENT_TYPE_NAME (event), peerpad);
4048 gst_object_ref (peerpad);
4049 GST_OBJECT_UNLOCK (pad);
4051 result = gst_pad_send_event (peerpad, event);
4053 /* Note: we gave away ownership of the event at this point */
4054 GST_LOG_OBJECT (pad, "sent event to peerpad %" GST_PTR_FORMAT, peerpad);
4055 gst_object_unref (peerpad);
4059 /* ERROR handling */
4062 GST_DEBUG_OBJECT (pad, "Dropping event after FALSE probe return");
4063 gst_event_unref (event);
4068 GST_DEBUG_OBJECT (pad, "Dropping event because pad is not linked");
4069 gst_event_unref (event);
4070 GST_OBJECT_UNLOCK (pad);
4075 GST_DEBUG_OBJECT (pad,
4076 "Not forwarding event since we're flushing and blocking");
4077 gst_event_unref (event);
4078 GST_OBJECT_UNLOCK (pad);
4084 * gst_pad_send_event:
4085 * @pad: a #GstPad to send the event to.
4086 * @event: the #GstEvent to send to the pad.
4088 * Sends the event to the pad. This function can be used
4089 * by applications to send events in the pipeline.
4091 * If @pad is a source pad, @event should be an upstream event. If @pad is a
4092 * sink pad, @event should be a downstream event. For example, you would not
4093 * send a #GST_EVENT_EOS on a src pad; EOS events only propagate downstream.
4094 * Furthermore, some downstream events have to be serialized with data flow,
4095 * like EOS, while some can travel out-of-band, like #GST_EVENT_FLUSH_START. If
4096 * the event needs to be serialized with data flow, this function will take the
4097 * pad's stream lock while calling its event function.
4099 * To find out whether an event type is upstream, downstream, or downstream and
4100 * serialized, see #GstEventTypeFlags, gst_event_type_get_flags(),
4101 * #GST_EVENT_IS_UPSTREAM, #GST_EVENT_IS_DOWNSTREAM, and
4102 * #GST_EVENT_IS_SERIALIZED. Note that in practice that an application or plugin
4103 * doesn't need to bother itself with this information; the core handles all
4104 * necessary locks and checks.
4106 * This function takes owership of the provided event so you should
4107 * gst_event_ref() it if you want to reuse the event after this call.
4109 * Returns: TRUE if the event was handled.
4112 gst_pad_send_event (GstPad * pad, GstEvent * event)
4114 gboolean result = FALSE;
4115 GstPadEventFunction eventfunc;
4116 gboolean serialized, need_unlock = FALSE;
4118 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
4119 g_return_val_if_fail (event != NULL, FALSE);
4121 GST_OBJECT_LOCK (pad);
4122 if (GST_PAD_IS_SINK (pad)) {
4123 if (G_UNLIKELY (!GST_EVENT_IS_DOWNSTREAM (event)))
4124 goto wrong_direction;
4125 serialized = GST_EVENT_IS_SERIALIZED (event);
4126 } else if (GST_PAD_IS_SRC (pad)) {
4127 if (G_UNLIKELY (!GST_EVENT_IS_UPSTREAM (event)))
4128 goto wrong_direction;
4129 /* events on srcpad never are serialized */
4132 goto unknown_direction;
4134 if (G_UNLIKELY (GST_EVENT_SRC (event) == NULL)) {
4135 GST_LOG_OBJECT (pad, "event had no source, setting pad as event source");
4136 GST_EVENT_SRC (event) = gst_object_ref (pad);
4140 if (G_UNLIKELY (GST_PAD_DO_EVENT_SIGNALS (pad) > 0)) {
4141 GST_OBJECT_UNLOCK (pad);
4143 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT_CAST (event)))
4146 GST_OBJECT_LOCK (pad);
4149 switch (GST_EVENT_TYPE (event)) {
4150 case GST_EVENT_FLUSH_START:
4151 GST_CAT_DEBUG_OBJECT (GST_CAT_EVENT, pad,
4152 "have event type %d (FLUSH_START)", GST_EVENT_TYPE (event));
4154 /* can't even accept a flush begin event when flushing */
4155 if (GST_PAD_IS_FLUSHING (pad))
4157 GST_PAD_SET_FLUSHING (pad);
4158 GST_CAT_DEBUG_OBJECT (GST_CAT_EVENT, pad, "set flush flag");
4160 case GST_EVENT_FLUSH_STOP:
4161 GST_PAD_UNSET_FLUSHING (pad);
4162 GST_CAT_DEBUG_OBJECT (GST_CAT_EVENT, pad, "cleared flush flag");
4163 GST_OBJECT_UNLOCK (pad);
4164 /* grab stream lock */
4165 GST_PAD_STREAM_LOCK (pad);
4167 GST_OBJECT_LOCK (pad);
4170 GST_CAT_DEBUG_OBJECT (GST_CAT_EVENT, pad, "have event type %s",
4171 GST_EVENT_TYPE_NAME (event));
4173 /* make this a little faster, no point in grabbing the lock
4174 * if the pad is allready flushing. */
4175 if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad)))
4179 /* lock order: STREAM_LOCK, LOCK, recheck flushing. */
4180 GST_OBJECT_UNLOCK (pad);
4181 GST_PAD_STREAM_LOCK (pad);
4183 GST_OBJECT_LOCK (pad);
4184 if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad)))
4189 if (G_UNLIKELY ((eventfunc = GST_PAD_EVENTFUNC (pad)) == NULL))
4192 GST_OBJECT_UNLOCK (pad);
4194 result = eventfunc (pad, event);
4197 GST_PAD_STREAM_UNLOCK (pad);
4201 /* ERROR handling */
4204 g_warning ("pad %s:%s sending %s event in wrong direction",
4205 GST_DEBUG_PAD_NAME (pad), GST_EVENT_TYPE_NAME (event));
4206 GST_OBJECT_UNLOCK (pad);
4207 gst_event_unref (event);
4212 g_warning ("pad %s:%s has invalid direction", GST_DEBUG_PAD_NAME (pad));
4213 GST_OBJECT_UNLOCK (pad);
4214 gst_event_unref (event);
4219 g_warning ("pad %s:%s has no event handler, file a bug.",
4220 GST_DEBUG_PAD_NAME (pad));
4221 GST_OBJECT_UNLOCK (pad);
4222 gst_event_unref (event);
4227 GST_OBJECT_UNLOCK (pad);
4229 GST_PAD_STREAM_UNLOCK (pad);
4230 GST_CAT_INFO_OBJECT (GST_CAT_EVENT, pad,
4231 "Received event on flushing pad. Discarding");
4232 gst_event_unref (event);
4237 GST_DEBUG_OBJECT (pad, "Dropping event after FALSE probe return");
4238 gst_event_unref (event);
4244 * gst_pad_set_element_private:
4245 * @pad: the #GstPad to set the private data of.
4246 * @priv: The private data to attach to the pad.
4248 * Set the given private data gpointer on the pad.
4249 * This function can only be used by the element that owns the pad.
4250 * No locking is performed in this function.
4253 gst_pad_set_element_private (GstPad * pad, gpointer priv)
4255 pad->element_private = priv;
4259 * gst_pad_get_element_private:
4260 * @pad: the #GstPad to get the private data of.
4262 * Gets the private data of a pad.
4263 * No locking is performed in this function.
4265 * Returns: a #gpointer to the private data.
4268 gst_pad_get_element_private (GstPad * pad)
4270 return pad->element_private;
4274 * gst_pad_start_task:
4275 * @pad: the #GstPad to start the task of
4276 * @func: the task function to call
4277 * @data: data passed to the task function
4279 * Starts a task that repeatedly calls @func with @data. This function
4280 * is mostly used in pad activation functions to start the dataflow.
4281 * The #GST_PAD_STREAM_LOCK of @pad will automatically be acquired
4282 * before @func is called.
4284 * Returns: a %TRUE if the task could be started.
4287 gst_pad_start_task (GstPad * pad, GstTaskFunction func, gpointer data)
4291 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
4292 g_return_val_if_fail (func != NULL, FALSE);
4294 GST_DEBUG_OBJECT (pad, "start task");
4296 GST_OBJECT_LOCK (pad);
4297 task = GST_PAD_TASK (pad);
4299 task = gst_task_create (func, data);
4300 gst_task_set_lock (task, GST_PAD_GET_STREAM_LOCK (pad));
4301 GST_PAD_TASK (pad) = task;
4302 GST_DEBUG_OBJECT (pad, "created task");
4304 gst_task_start (task);
4305 GST_OBJECT_UNLOCK (pad);
4311 * gst_pad_pause_task:
4312 * @pad: the #GstPad to pause the task of
4314 * Pause the task of @pad. This function will also make sure that the
4315 * function executed by the task will effectively stop.
4317 * Returns: a TRUE if the task could be paused or FALSE when the pad
4321 gst_pad_pause_task (GstPad * pad)
4325 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
4327 GST_DEBUG_OBJECT (pad, "pause task");
4329 GST_OBJECT_LOCK (pad);
4330 task = GST_PAD_TASK (pad);
4333 gst_task_pause (task);
4334 GST_OBJECT_UNLOCK (pad);
4336 GST_PAD_STREAM_LOCK (pad);
4337 GST_PAD_STREAM_UNLOCK (pad);
4343 GST_DEBUG_OBJECT (pad, "pad has no task");
4344 GST_OBJECT_UNLOCK (pad);
4350 * gst_pad_stop_task:
4351 * @pad: the #GstPad to stop the task of
4353 * Stop the task of @pad. This function will also make sure that the
4354 * function executed by the task will effectively stop if not called
4355 * from the GstTaskFunction.
4357 * This function will deadlock if called from the GstTaskFunction of
4358 * the task. Use gst_task_pause() instead.
4360 * Regardless of whether the pad has a task, the stream lock is acquired and
4361 * released so as to ensure that streaming through this pad has finished.
4363 * Returns: a TRUE if the task could be stopped or FALSE on error.
4366 gst_pad_stop_task (GstPad * pad)
4370 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
4372 GST_DEBUG_OBJECT (pad, "stop task");
4374 GST_OBJECT_LOCK (pad);
4375 task = GST_PAD_TASK (pad);
4378 GST_PAD_TASK (pad) = NULL;
4379 gst_task_stop (task);
4380 GST_OBJECT_UNLOCK (pad);
4382 GST_PAD_STREAM_LOCK (pad);
4383 GST_PAD_STREAM_UNLOCK (pad);
4385 if (!gst_task_join (task))
4388 gst_object_unref (task);
4394 GST_DEBUG_OBJECT (pad, "no task");
4395 GST_OBJECT_UNLOCK (pad);
4397 GST_PAD_STREAM_LOCK (pad);
4398 GST_PAD_STREAM_UNLOCK (pad);
4400 /* this is not an error */
4405 /* this is bad, possibly the application tried to join the task from
4406 * the task's thread. We install the task again so that it will be stopped
4407 * again from the right thread next time hopefully. */
4408 GST_OBJECT_LOCK (pad);
4409 GST_DEBUG_OBJECT (pad, "join failed");
4410 /* we can only install this task if there was no other task */
4411 if (GST_PAD_TASK (pad) == NULL)
4412 GST_PAD_TASK (pad) = task;
4413 GST_OBJECT_UNLOCK (pad);