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
690 * is expected to activate its internally linked pads from within its
691 * activate_pull function.
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 if the
968 * wrong parameters were passed or the pad was already in the requested state.
973 gst_pad_set_blocked_async (GstPad * pad, gboolean blocked,
974 GstPadBlockCallback callback, gpointer user_data)
976 gboolean was_blocked = FALSE;
978 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
980 GST_OBJECT_LOCK (pad);
982 was_blocked = GST_PAD_IS_BLOCKED (pad);
984 if (G_UNLIKELY (was_blocked == blocked))
985 goto had_right_state;
988 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "blocking pad");
990 GST_OBJECT_FLAG_SET (pad, GST_PAD_BLOCKED);
991 pad->block_callback = callback;
992 pad->block_data = user_data;
994 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "waiting for block");
995 GST_PAD_BLOCK_WAIT (pad);
996 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "blocked");
999 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "unblocking pad");
1001 GST_OBJECT_FLAG_UNSET (pad, GST_PAD_BLOCKED);
1003 pad->block_callback = callback;
1004 pad->block_data = user_data;
1006 GST_PAD_BLOCK_BROADCAST (pad);
1008 /* no callback, wait for the unblock to happen */
1009 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "waiting for unblock");
1010 GST_PAD_BLOCK_WAIT (pad);
1011 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "unblocked");
1014 GST_OBJECT_UNLOCK (pad);
1020 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
1021 "pad was in right state (%d)", was_blocked);
1022 GST_OBJECT_UNLOCK (pad);
1029 * gst_pad_set_blocked:
1030 * @pad: the #GstPad to block or unblock
1031 * @blocked: boolean indicating we should block or unblock
1033 * Blocks or unblocks the dataflow on a pad. This function is
1034 * a shortcut for gst_pad_set_blocked_async() with a NULL
1037 * Returns: TRUE if the pad could be blocked. This function can fail if the
1038 * wrong parameters were passed or the pad was already in the requested state.
1043 gst_pad_set_blocked (GstPad * pad, gboolean blocked)
1045 return gst_pad_set_blocked_async (pad, blocked, NULL, NULL);
1049 * gst_pad_is_blocked:
1050 * @pad: the #GstPad to query
1052 * Checks if the pad is blocked or not. This function returns the
1053 * last requested state of the pad. It is not certain that the pad
1054 * is actually blocking at this point (see gst_pad_is_blocking()).
1056 * Returns: TRUE if the pad is blocked.
1061 gst_pad_is_blocked (GstPad * pad)
1063 gboolean result = FALSE;
1065 g_return_val_if_fail (GST_IS_PAD (pad), result);
1067 GST_OBJECT_LOCK (pad);
1068 result = GST_OBJECT_FLAG_IS_SET (pad, GST_PAD_BLOCKED);
1069 GST_OBJECT_UNLOCK (pad);
1075 * gst_pad_is_blocking:
1076 * @pad: the #GstPad to query
1078 * Checks if the pad is blocking or not. This is a guaranteed state
1079 * of whether the pad is actually blocking on a #GstBuffer or a #GstEvent.
1081 * Returns: TRUE if the pad is blocking.
1088 gst_pad_is_blocking (GstPad * pad)
1090 gboolean result = FALSE;
1092 g_return_val_if_fail (GST_IS_PAD (pad), result);
1094 GST_OBJECT_LOCK (pad);
1095 /* the blocking flag is only valid if the pad is not flushing */
1096 result = GST_OBJECT_FLAG_IS_SET (pad, GST_PAD_BLOCKING) &&
1097 !GST_OBJECT_FLAG_IS_SET (pad, GST_PAD_FLUSHING);
1098 GST_OBJECT_UNLOCK (pad);
1104 * gst_pad_set_activate_function:
1106 * @activate: the #GstPadActivateFunction to set.
1108 * Sets the given activate function for @pad. The activate function will
1109 * dispatch to gst_pad_activate_push() or gst_pad_activate_pull() to perform
1110 * the actual activation. Only makes sense to set on sink pads.
1112 * Call this function if your sink pad can start a pull-based task.
1115 gst_pad_set_activate_function (GstPad * pad, GstPadActivateFunction activate)
1117 g_return_if_fail (GST_IS_PAD (pad));
1119 GST_PAD_ACTIVATEFUNC (pad) = activate;
1120 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "activatefunc set to %s",
1121 GST_DEBUG_FUNCPTR_NAME (activate));
1125 * gst_pad_set_activatepull_function:
1127 * @activatepull: the #GstPadActivateModeFunction to set.
1129 * Sets the given activate_pull function for the pad. An activate_pull function
1130 * prepares the element and any upstream connections for pulling. See XXX
1131 * part-activation.txt for details.
1134 gst_pad_set_activatepull_function (GstPad * pad,
1135 GstPadActivateModeFunction activatepull)
1137 g_return_if_fail (GST_IS_PAD (pad));
1139 GST_PAD_ACTIVATEPULLFUNC (pad) = activatepull;
1140 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "activatepullfunc set to %s",
1141 GST_DEBUG_FUNCPTR_NAME (activatepull));
1145 * gst_pad_set_activatepush_function:
1147 * @activatepush: the #GstPadActivateModeFunction to set.
1149 * Sets the given activate_push function for the pad. An activate_push function
1150 * prepares the element for pushing. See XXX part-activation.txt for details.
1153 gst_pad_set_activatepush_function (GstPad * pad,
1154 GstPadActivateModeFunction activatepush)
1156 g_return_if_fail (GST_IS_PAD (pad));
1158 GST_PAD_ACTIVATEPUSHFUNC (pad) = activatepush;
1159 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "activatepushfunc set to %s",
1160 GST_DEBUG_FUNCPTR_NAME (activatepush));
1164 * gst_pad_set_chain_function:
1165 * @pad: a sink #GstPad.
1166 * @chain: the #GstPadChainFunction to set.
1168 * Sets the given chain function for the pad. The chain function is called to
1169 * process a #GstBuffer input buffer. see #GstPadChainFunction for more details.
1172 gst_pad_set_chain_function (GstPad * pad, GstPadChainFunction chain)
1174 g_return_if_fail (GST_IS_PAD (pad));
1175 g_return_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SINK);
1177 GST_PAD_CHAINFUNC (pad) = chain;
1178 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "chainfunc set to %s",
1179 GST_DEBUG_FUNCPTR_NAME (chain));
1183 * gst_pad_set_getrange_function:
1184 * @pad: a source #GstPad.
1185 * @get: the #GstPadGetRangeFunction to set.
1187 * Sets the given getrange function for the pad. The getrange function is
1188 * called to produce a new #GstBuffer to start the processing pipeline. see
1189 * #GstPadGetRangeFunction for a description of the getrange function.
1192 gst_pad_set_getrange_function (GstPad * pad, GstPadGetRangeFunction get)
1194 g_return_if_fail (GST_IS_PAD (pad));
1195 g_return_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SRC);
1197 GST_PAD_GETRANGEFUNC (pad) = get;
1199 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "getrangefunc set to %s",
1200 GST_DEBUG_FUNCPTR_NAME (get));
1204 * gst_pad_set_checkgetrange_function:
1205 * @pad: a source #GstPad.
1206 * @check: the #GstPadCheckGetRangeFunction to set.
1208 * Sets the given checkgetrange function for the pad. Implement this function
1209 * on a pad if you dynamically support getrange based scheduling on the pad.
1212 gst_pad_set_checkgetrange_function (GstPad * pad,
1213 GstPadCheckGetRangeFunction check)
1215 g_return_if_fail (GST_IS_PAD (pad));
1216 g_return_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SRC);
1218 GST_PAD_CHECKGETRANGEFUNC (pad) = check;
1220 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "checkgetrangefunc set to %s",
1221 GST_DEBUG_FUNCPTR_NAME (check));
1225 * gst_pad_set_event_function:
1226 * @pad: a #GstPad of either direction.
1227 * @event: the #GstPadEventFunction to set.
1229 * Sets the given event handler for the pad.
1232 gst_pad_set_event_function (GstPad * pad, GstPadEventFunction event)
1234 g_return_if_fail (GST_IS_PAD (pad));
1236 GST_PAD_EVENTFUNC (pad) = event;
1238 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "eventfunc for set to %s",
1239 GST_DEBUG_FUNCPTR_NAME (event));
1243 * gst_pad_set_query_function:
1244 * @pad: a #GstPad of either direction.
1245 * @query: the #GstPadQueryFunction to set.
1247 * Set the given query function for the pad.
1250 gst_pad_set_query_function (GstPad * pad, GstPadQueryFunction query)
1252 g_return_if_fail (GST_IS_PAD (pad));
1254 GST_PAD_QUERYFUNC (pad) = query;
1256 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "queryfunc set to %s",
1257 GST_DEBUG_FUNCPTR_NAME (query));
1261 * gst_pad_set_query_type_function:
1262 * @pad: a #GstPad of either direction.
1263 * @type_func: the #GstPadQueryTypeFunction to set.
1265 * Set the given query type function for the pad.
1268 gst_pad_set_query_type_function (GstPad * pad,
1269 GstPadQueryTypeFunction type_func)
1271 g_return_if_fail (GST_IS_PAD (pad));
1273 GST_PAD_QUERYTYPEFUNC (pad) = type_func;
1275 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "querytypefunc set to %s",
1276 GST_DEBUG_FUNCPTR_NAME (type_func));
1280 * gst_pad_get_query_types:
1283 * Get an array of supported queries that can be performed
1286 * Returns: a zero-terminated array of #GstQueryType.
1288 const GstQueryType *
1289 gst_pad_get_query_types (GstPad * pad)
1291 GstPadQueryTypeFunction func;
1293 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
1295 if (G_UNLIKELY ((func = GST_PAD_QUERYTYPEFUNC (pad)) == NULL))
1307 gst_pad_get_query_types_dispatcher (GstPad * pad, const GstQueryType ** data)
1309 *data = gst_pad_get_query_types (pad);
1315 * gst_pad_get_query_types_default:
1318 * Invoke the default dispatcher for the query types on
1321 * Returns: an zero-terminated array of #GstQueryType, or NULL if none of the
1322 * internally-linked pads has a query types function.
1324 const GstQueryType *
1325 gst_pad_get_query_types_default (GstPad * pad)
1327 GstQueryType *result = NULL;
1329 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
1331 gst_pad_dispatcher (pad, (GstPadDispatcherFunction)
1332 gst_pad_get_query_types_dispatcher, &result);
1338 * gst_pad_set_internal_link_function:
1339 * @pad: a #GstPad of either direction.
1340 * @intlink: the #GstPadIntLinkFunction to set.
1342 * Sets the given internal link function for the pad.
1345 gst_pad_set_internal_link_function (GstPad * pad, GstPadIntLinkFunction intlink)
1347 g_return_if_fail (GST_IS_PAD (pad));
1349 GST_PAD_INTLINKFUNC (pad) = intlink;
1350 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "internal link set to %s",
1351 GST_DEBUG_FUNCPTR_NAME (intlink));
1355 * gst_pad_set_link_function:
1357 * @link: the #GstPadLinkFunction to set.
1359 * Sets the given link function for the pad. It will be called when
1360 * the pad is linked with another pad.
1362 * The return value #GST_PAD_LINK_OK should be used when the connection can be
1365 * The return value #GST_PAD_LINK_REFUSED should be used when the connection
1366 * cannot be made for some reason.
1368 * If @link is installed on a source pad, it should call the #GstPadLinkFunction
1369 * of the peer sink pad, if present.
1372 gst_pad_set_link_function (GstPad * pad, GstPadLinkFunction link)
1374 g_return_if_fail (GST_IS_PAD (pad));
1376 GST_PAD_LINKFUNC (pad) = link;
1377 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "linkfunc set to %s",
1378 GST_DEBUG_FUNCPTR_NAME (link));
1382 * gst_pad_set_unlink_function:
1384 * @unlink: the #GstPadUnlinkFunction to set.
1386 * Sets the given unlink function for the pad. It will be called
1387 * when the pad is unlinked.
1390 gst_pad_set_unlink_function (GstPad * pad, GstPadUnlinkFunction unlink)
1392 g_return_if_fail (GST_IS_PAD (pad));
1394 GST_PAD_UNLINKFUNC (pad) = unlink;
1395 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "unlinkfunc set to %s",
1396 GST_DEBUG_FUNCPTR_NAME (unlink));
1400 * gst_pad_set_getcaps_function:
1402 * @getcaps: the #GstPadGetCapsFunction to set.
1404 * Sets the given getcaps function for the pad. @getcaps should return the
1405 * allowable caps for a pad in the context of the element's state, its link to
1406 * other elements, and the devices or files it has opened. These caps must be a
1407 * subset of the pad template caps. In the NULL state with no links, @getcaps
1408 * should ideally return the same caps as the pad template. In rare
1409 * circumstances, an object property can affect the caps returned by @getcaps,
1410 * but this is discouraged.
1412 * You do not need to call this function if @pad's allowed caps are always the
1413 * same as the pad template caps. This can only be true if the padtemplate
1414 * has fixed simple caps.
1416 * For most filters, the caps returned by @getcaps is directly affected by the
1417 * allowed caps on other pads. For demuxers and decoders, the caps returned by
1418 * the srcpad's getcaps function is directly related to the stream data. Again,
1419 * @getcaps should return the most specific caps it reasonably can, since this
1420 * helps with autoplugging.
1422 * Note that the return value from @getcaps is owned by the caller, so the
1423 * caller should unref the caps after usage.
1426 gst_pad_set_getcaps_function (GstPad * pad, GstPadGetCapsFunction getcaps)
1428 g_return_if_fail (GST_IS_PAD (pad));
1430 GST_PAD_GETCAPSFUNC (pad) = getcaps;
1431 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "getcapsfunc set to %s",
1432 GST_DEBUG_FUNCPTR_NAME (getcaps));
1436 * gst_pad_set_acceptcaps_function:
1438 * @acceptcaps: the #GstPadAcceptCapsFunction to set.
1440 * Sets the given acceptcaps function for the pad. The acceptcaps function
1441 * will be called to check if the pad can accept the given caps. Setting the
1442 * acceptcaps function to NULL restores the default behaviour of allowing
1443 * any caps that matches the caps from gst_pad_get_caps.
1446 gst_pad_set_acceptcaps_function (GstPad * pad,
1447 GstPadAcceptCapsFunction acceptcaps)
1449 g_return_if_fail (GST_IS_PAD (pad));
1451 GST_PAD_ACCEPTCAPSFUNC (pad) = acceptcaps;
1452 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "acceptcapsfunc set to %s",
1453 GST_DEBUG_FUNCPTR_NAME (acceptcaps));
1457 * gst_pad_set_fixatecaps_function:
1459 * @fixatecaps: the #GstPadFixateCapsFunction to set.
1461 * Sets the given fixatecaps function for the pad. The fixatecaps function
1462 * will be called whenever the default values for a GstCaps needs to be
1466 gst_pad_set_fixatecaps_function (GstPad * pad,
1467 GstPadFixateCapsFunction fixatecaps)
1469 g_return_if_fail (GST_IS_PAD (pad));
1471 GST_PAD_FIXATECAPSFUNC (pad) = fixatecaps;
1472 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "fixatecapsfunc set to %s",
1473 GST_DEBUG_FUNCPTR_NAME (fixatecaps));
1477 * gst_pad_set_setcaps_function:
1479 * @setcaps: the #GstPadSetCapsFunction to set.
1481 * Sets the given setcaps function for the pad. The setcaps function
1482 * will be called whenever a buffer with a new media type is pushed or
1483 * pulled from the pad. The pad/element needs to update its internal
1484 * structures to process the new media type. If this new type is not
1485 * acceptable, the setcaps function should return FALSE.
1488 gst_pad_set_setcaps_function (GstPad * pad, GstPadSetCapsFunction setcaps)
1490 g_return_if_fail (GST_IS_PAD (pad));
1492 GST_PAD_SETCAPSFUNC (pad) = setcaps;
1493 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "setcapsfunc set to %s",
1494 GST_DEBUG_FUNCPTR_NAME (setcaps));
1498 * gst_pad_set_bufferalloc_function:
1499 * @pad: a sink #GstPad.
1500 * @bufalloc: the #GstPadBufferAllocFunction to set.
1502 * Sets the given bufferalloc function for the pad. Note that the
1503 * bufferalloc function can only be set on sinkpads.
1506 gst_pad_set_bufferalloc_function (GstPad * pad,
1507 GstPadBufferAllocFunction bufalloc)
1509 g_return_if_fail (GST_IS_PAD (pad));
1510 g_return_if_fail (GST_PAD_IS_SINK (pad));
1512 GST_PAD_BUFFERALLOCFUNC (pad) = bufalloc;
1513 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "bufferallocfunc set to %s",
1514 GST_DEBUG_FUNCPTR_NAME (bufalloc));
1519 * @srcpad: the source #GstPad to unlink.
1520 * @sinkpad: the sink #GstPad to unlink.
1522 * Unlinks the source pad from the sink pad. Will emit the "unlinked" signal on
1525 * Returns: TRUE if the pads were unlinked. This function returns FALSE if
1526 * the pads were not linked together.
1531 gst_pad_unlink (GstPad * srcpad, GstPad * sinkpad)
1533 g_return_val_if_fail (GST_IS_PAD (srcpad), FALSE);
1534 g_return_val_if_fail (GST_IS_PAD (sinkpad), FALSE);
1536 GST_CAT_INFO (GST_CAT_ELEMENT_PADS, "unlinking %s:%s(%p) and %s:%s(%p)",
1537 GST_DEBUG_PAD_NAME (srcpad), srcpad,
1538 GST_DEBUG_PAD_NAME (sinkpad), sinkpad);
1540 GST_OBJECT_LOCK (srcpad);
1542 if (G_UNLIKELY (GST_PAD_DIRECTION (srcpad) != GST_PAD_SRC))
1545 GST_OBJECT_LOCK (sinkpad);
1547 if (G_UNLIKELY (GST_PAD_DIRECTION (sinkpad) != GST_PAD_SINK))
1550 if (G_UNLIKELY (GST_PAD_PEER (srcpad) != sinkpad))
1551 goto not_linked_together;
1553 if (GST_PAD_UNLINKFUNC (srcpad)) {
1554 GST_PAD_UNLINKFUNC (srcpad) (srcpad);
1556 if (GST_PAD_UNLINKFUNC (sinkpad)) {
1557 GST_PAD_UNLINKFUNC (sinkpad) (sinkpad);
1560 /* first clear peers */
1561 GST_PAD_PEER (srcpad) = NULL;
1562 GST_PAD_PEER (sinkpad) = NULL;
1564 GST_OBJECT_UNLOCK (sinkpad);
1565 GST_OBJECT_UNLOCK (srcpad);
1567 /* fire off a signal to each of the pads telling them
1568 * that they've been unlinked */
1569 g_signal_emit (G_OBJECT (srcpad), gst_pad_signals[PAD_UNLINKED], 0, sinkpad);
1570 g_signal_emit (G_OBJECT (sinkpad), gst_pad_signals[PAD_UNLINKED], 0, srcpad);
1572 GST_CAT_INFO (GST_CAT_ELEMENT_PADS, "unlinked %s:%s and %s:%s",
1573 GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (sinkpad));
1579 g_critical ("pad %s is not a source pad", GST_PAD_NAME (srcpad));
1580 GST_OBJECT_UNLOCK (srcpad);
1585 g_critical ("pad %s is not a sink pad", GST_PAD_NAME (sinkpad));
1586 GST_OBJECT_UNLOCK (sinkpad);
1587 GST_OBJECT_UNLOCK (srcpad);
1590 not_linked_together:
1592 /* we do not emit a warning in this case because unlinking cannot
1593 * be made MT safe.*/
1594 GST_OBJECT_UNLOCK (sinkpad);
1595 GST_OBJECT_UNLOCK (srcpad);
1601 * gst_pad_is_linked:
1602 * @pad: pad to check
1604 * Checks if a @pad is linked to another pad or not.
1606 * Returns: TRUE if the pad is linked, FALSE otherwise.
1611 gst_pad_is_linked (GstPad * pad)
1615 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
1617 GST_OBJECT_LOCK (pad);
1618 result = (GST_PAD_PEER (pad) != NULL);
1619 GST_OBJECT_UNLOCK (pad);
1624 /* get the caps from both pads and see if the intersection
1627 * This function should be called with the pad LOCK on both
1631 gst_pad_link_check_compatible_unlocked (GstPad * src, GstPad * sink)
1637 srccaps = gst_pad_get_caps_unlocked (src);
1638 sinkcaps = gst_pad_get_caps_unlocked (sink);
1640 GST_CAT_DEBUG (GST_CAT_CAPS, "src caps %" GST_PTR_FORMAT, srccaps);
1641 GST_CAT_DEBUG (GST_CAT_CAPS, "sink caps %" GST_PTR_FORMAT, sinkcaps);
1643 /* if we have caps on both pads we can check the intersection. If one
1644 * of the caps is NULL, we return TRUE. */
1645 if (srccaps == NULL || sinkcaps == NULL)
1648 icaps = gst_caps_intersect (srccaps, sinkcaps);
1649 gst_caps_unref (srccaps);
1650 gst_caps_unref (sinkcaps);
1655 GST_CAT_DEBUG (GST_CAT_CAPS,
1656 "intersection caps %p %" GST_PTR_FORMAT, icaps, icaps);
1658 if (gst_caps_is_empty (icaps))
1661 gst_caps_unref (icaps);
1666 /* incompatible cases */
1669 GST_CAT_DEBUG (GST_CAT_CAPS, "intersection gave NULL");
1674 GST_CAT_DEBUG (GST_CAT_CAPS, "intersection is EMPTY");
1675 gst_caps_unref (icaps);
1680 /* check if the grandparents of both pads are the same.
1681 * This check is required so that we don't try to link
1682 * pads from elements in different bins without ghostpads.
1684 * The LOCK should be held on both pads
1687 gst_pad_link_check_hierarchy (GstPad * src, GstPad * sink)
1689 GstObject *psrc, *psink;
1691 psrc = GST_OBJECT_PARENT (src);
1692 psink = GST_OBJECT_PARENT (sink);
1694 /* if one of the pads has no parent, we allow the link */
1695 if (G_UNLIKELY (psrc == NULL || psink == NULL))
1698 /* only care about parents that are elements */
1699 if (G_UNLIKELY (!GST_IS_ELEMENT (psrc) || !GST_IS_ELEMENT (psink)))
1700 goto no_element_parent;
1702 /* if the parents are the same, we have a loop */
1703 if (G_UNLIKELY (psrc == psink))
1706 /* if they both have a parent, we check the grandparents. We can not lock
1707 * the parent because we hold on the child (pad) and the locking order is
1708 * parent >> child. */
1709 psrc = GST_OBJECT_PARENT (psrc);
1710 psink = GST_OBJECT_PARENT (psink);
1712 /* if they have grandparents but they are not the same */
1713 if (G_UNLIKELY (psrc != psink))
1714 goto wrong_grandparents;
1721 GST_CAT_DEBUG (GST_CAT_CAPS,
1722 "one of the pads has no parent %" GST_PTR_FORMAT " and %"
1723 GST_PTR_FORMAT, psrc, psink);
1728 GST_CAT_DEBUG (GST_CAT_CAPS,
1729 "one of the pads has no element parent %" GST_PTR_FORMAT " and %"
1730 GST_PTR_FORMAT, psrc, psink);
1735 GST_CAT_DEBUG (GST_CAT_CAPS, "pads have same parent %" GST_PTR_FORMAT,
1741 GST_CAT_DEBUG (GST_CAT_CAPS,
1742 "pads have different grandparents %" GST_PTR_FORMAT " and %"
1743 GST_PTR_FORMAT, psrc, psink);
1748 /* FIXME leftover from an attempt at refactoring... */
1749 /* call with the two pads unlocked, when this function returns GST_PAD_LINK_OK,
1750 * the two pads will be locked in the srcpad, sinkpad order. */
1751 static GstPadLinkReturn
1752 gst_pad_link_prepare (GstPad * srcpad, GstPad * sinkpad)
1754 /* generic checks */
1755 g_return_val_if_fail (GST_IS_PAD (srcpad), GST_PAD_LINK_REFUSED);
1756 g_return_val_if_fail (GST_IS_PAD (sinkpad), GST_PAD_LINK_REFUSED);
1758 GST_CAT_INFO (GST_CAT_PADS, "trying to link %s:%s and %s:%s",
1759 GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (sinkpad));
1761 GST_OBJECT_LOCK (srcpad);
1763 if (G_UNLIKELY (GST_PAD_DIRECTION (srcpad) != GST_PAD_SRC))
1766 if (G_UNLIKELY (GST_PAD_PEER (srcpad) != NULL))
1767 goto src_was_linked;
1769 GST_OBJECT_LOCK (sinkpad);
1771 if (G_UNLIKELY (GST_PAD_DIRECTION (sinkpad) != GST_PAD_SINK))
1774 if (G_UNLIKELY (GST_PAD_PEER (sinkpad) != NULL))
1775 goto sink_was_linked;
1777 /* check hierarchy, pads can only be linked if the grandparents
1779 if (!gst_pad_link_check_hierarchy (srcpad, sinkpad))
1780 goto wrong_hierarchy;
1782 /* check pad caps for non-empty intersection */
1783 if (!gst_pad_link_check_compatible_unlocked (srcpad, sinkpad))
1786 /* FIXME check pad scheduling for non-empty intersection */
1788 return GST_PAD_LINK_OK;
1792 g_critical ("pad %s is not a source pad", GST_PAD_NAME (srcpad));
1793 GST_OBJECT_UNLOCK (srcpad);
1794 return GST_PAD_LINK_WRONG_DIRECTION;
1798 GST_CAT_INFO (GST_CAT_PADS, "src %s:%s was already linked to %s:%s",
1799 GST_DEBUG_PAD_NAME (srcpad),
1800 GST_DEBUG_PAD_NAME (GST_PAD_PEER (srcpad)));
1801 /* we do not emit a warning in this case because unlinking cannot
1802 * be made MT safe.*/
1803 GST_OBJECT_UNLOCK (srcpad);
1804 return GST_PAD_LINK_WAS_LINKED;
1808 g_critical ("pad %s is not a sink pad", GST_PAD_NAME (sinkpad));
1809 GST_OBJECT_UNLOCK (sinkpad);
1810 GST_OBJECT_UNLOCK (srcpad);
1811 return GST_PAD_LINK_WRONG_DIRECTION;
1815 GST_CAT_INFO (GST_CAT_PADS, "sink %s:%s was already linked to %s:%s",
1816 GST_DEBUG_PAD_NAME (sinkpad),
1817 GST_DEBUG_PAD_NAME (GST_PAD_PEER (sinkpad)));
1818 /* we do not emit a warning in this case because unlinking cannot
1819 * be made MT safe.*/
1820 GST_OBJECT_UNLOCK (sinkpad);
1821 GST_OBJECT_UNLOCK (srcpad);
1822 return GST_PAD_LINK_WAS_LINKED;
1826 GST_CAT_INFO (GST_CAT_PADS, "pads have wrong hierarchy");
1827 GST_OBJECT_UNLOCK (sinkpad);
1828 GST_OBJECT_UNLOCK (srcpad);
1829 return GST_PAD_LINK_WRONG_HIERARCHY;
1833 GST_CAT_INFO (GST_CAT_PADS, "caps are incompatible");
1834 GST_OBJECT_UNLOCK (sinkpad);
1835 GST_OBJECT_UNLOCK (srcpad);
1836 return GST_PAD_LINK_NOFORMAT;
1842 * @srcpad: the source #GstPad to link.
1843 * @sinkpad: the sink #GstPad to link.
1845 * Links the source pad and the sink pad.
1847 * Returns: A result code indicating if the connection worked or
1853 gst_pad_link (GstPad * srcpad, GstPad * sinkpad)
1855 GstPadLinkReturn result;
1857 /* prepare will also lock the two pads */
1858 result = gst_pad_link_prepare (srcpad, sinkpad);
1860 if (result != GST_PAD_LINK_OK)
1861 goto prepare_failed;
1863 /* must set peers before calling the link function */
1864 GST_PAD_PEER (srcpad) = sinkpad;
1865 GST_PAD_PEER (sinkpad) = srcpad;
1867 GST_OBJECT_UNLOCK (sinkpad);
1868 GST_OBJECT_UNLOCK (srcpad);
1870 /* FIXME released the locks here, concurrent thread might link
1871 * something else. */
1872 if (GST_PAD_LINKFUNC (srcpad)) {
1873 /* this one will call the peer link function */
1874 result = GST_PAD_LINKFUNC (srcpad) (srcpad, sinkpad);
1875 } else if (GST_PAD_LINKFUNC (sinkpad)) {
1876 /* if no source link function, we need to call the sink link
1877 * function ourselves. */
1878 result = GST_PAD_LINKFUNC (sinkpad) (sinkpad, srcpad);
1880 result = GST_PAD_LINK_OK;
1883 GST_OBJECT_LOCK (srcpad);
1884 GST_OBJECT_LOCK (sinkpad);
1886 if (result == GST_PAD_LINK_OK) {
1887 GST_OBJECT_UNLOCK (sinkpad);
1888 GST_OBJECT_UNLOCK (srcpad);
1890 /* fire off a signal to each of the pads telling them
1891 * that they've been linked */
1892 g_signal_emit (G_OBJECT (srcpad), gst_pad_signals[PAD_LINKED], 0, sinkpad);
1893 g_signal_emit (G_OBJECT (sinkpad), gst_pad_signals[PAD_LINKED], 0, srcpad);
1895 GST_CAT_INFO (GST_CAT_PADS, "linked %s:%s and %s:%s, successful",
1896 GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (sinkpad));
1898 GST_CAT_INFO (GST_CAT_PADS, "link between %s:%s and %s:%s failed",
1899 GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (sinkpad));
1901 GST_PAD_PEER (srcpad) = NULL;
1902 GST_PAD_PEER (sinkpad) = NULL;
1904 GST_OBJECT_UNLOCK (sinkpad);
1905 GST_OBJECT_UNLOCK (srcpad);
1916 gst_pad_set_pad_template (GstPad * pad, GstPadTemplate * templ)
1918 GstPadTemplate **template_p;
1920 /* this function would need checks if it weren't static */
1922 GST_OBJECT_LOCK (pad);
1923 template_p = &pad->padtemplate;
1924 gst_object_replace ((GstObject **) template_p, (GstObject *) templ);
1925 GST_OBJECT_UNLOCK (pad);
1928 gst_pad_template_pad_created (templ, pad);
1932 * gst_pad_get_pad_template:
1935 * Gets the template for @pad.
1937 * Returns: the #GstPadTemplate from which this pad was instantiated, or %NULL
1938 * if this pad has no template.
1940 * FIXME: currently returns an unrefcounted padtemplate.
1943 gst_pad_get_pad_template (GstPad * pad)
1945 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
1947 return GST_PAD_PAD_TEMPLATE (pad);
1951 /* should be called with the pad LOCK held */
1952 /* refs the caps, so caller is responsible for getting it unreffed */
1954 gst_pad_get_caps_unlocked (GstPad * pad)
1956 GstCaps *result = NULL;
1958 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "get pad caps");
1960 if (GST_PAD_GETCAPSFUNC (pad)) {
1961 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
1962 "dispatching to pad getcaps function");
1964 GST_OBJECT_FLAG_SET (pad, GST_PAD_IN_GETCAPS);
1965 GST_OBJECT_UNLOCK (pad);
1966 result = GST_PAD_GETCAPSFUNC (pad) (pad);
1967 GST_OBJECT_LOCK (pad);
1968 GST_OBJECT_FLAG_UNSET (pad, GST_PAD_IN_GETCAPS);
1970 if (result == NULL) {
1971 g_critical ("pad %s:%s returned NULL caps from getcaps function",
1972 GST_DEBUG_PAD_NAME (pad));
1974 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
1975 "pad getcaps returned %" GST_PTR_FORMAT, result);
1976 #ifndef G_DISABLE_ASSERT
1977 /* check that the returned caps are a real subset of the template caps */
1978 if (GST_PAD_PAD_TEMPLATE (pad)) {
1979 const GstCaps *templ_caps =
1980 GST_PAD_TEMPLATE_CAPS (GST_PAD_PAD_TEMPLATE (pad));
1981 if (!gst_caps_is_subset (result, templ_caps)) {
1984 GST_CAT_ERROR_OBJECT (GST_CAT_CAPS, pad,
1985 "pad returned caps %" GST_PTR_FORMAT
1986 " which are not a real subset of its template caps %"
1987 GST_PTR_FORMAT, result, templ_caps);
1989 ("pad %s:%s returned caps which are not a real "
1990 "subset of its template caps", GST_DEBUG_PAD_NAME (pad));
1991 temp = gst_caps_intersect (templ_caps, result);
1992 gst_caps_unref (result);
2000 if (GST_PAD_PAD_TEMPLATE (pad)) {
2001 GstPadTemplate *templ = GST_PAD_PAD_TEMPLATE (pad);
2003 result = GST_PAD_TEMPLATE_CAPS (templ);
2004 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
2005 "using pad template %p with caps %p %" GST_PTR_FORMAT, templ, result,
2008 result = gst_caps_ref (result);
2011 if (GST_PAD_CAPS (pad)) {
2012 result = GST_PAD_CAPS (pad);
2014 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
2015 "using pad caps %p %" GST_PTR_FORMAT, result, result);
2017 result = gst_caps_ref (result);
2021 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "pad has no caps");
2022 result = gst_caps_new_empty ();
2030 * @pad: a #GstPad to get the capabilities of.
2032 * Gets the capabilities this pad can produce or consume.
2033 * Note that this method doesn't necessarily return the caps set by
2034 * gst_pad_set_caps() - use #GST_PAD_CAPS for that instead.
2035 * gst_pad_get_caps returns all possible caps a pad can operate with, using
2036 * the pad's get_caps function;
2037 * this returns the pad template caps if not explicitly set.
2039 * Returns: a newly allocated copy of the #GstCaps of this pad.
2044 gst_pad_get_caps (GstPad * pad)
2046 GstCaps *result = NULL;
2048 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2050 GST_OBJECT_LOCK (pad);
2052 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "get pad caps");
2054 result = gst_pad_get_caps_unlocked (pad);
2055 GST_OBJECT_UNLOCK (pad);
2061 * gst_pad_peer_get_caps:
2062 * @pad: a #GstPad to get the peer capabilities of.
2064 * Gets the capabilities of the peer connected to this pad.
2066 * Returns: the #GstCaps of the peer pad. This function returns a new caps, so
2067 * use gst_caps_unref to get rid of it. this function returns NULL if there is
2071 gst_pad_peer_get_caps (GstPad * pad)
2074 GstCaps *result = NULL;
2076 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2078 GST_OBJECT_LOCK (pad);
2080 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "get peer caps");
2082 peerpad = GST_PAD_PEER (pad);
2083 if (G_UNLIKELY (peerpad == NULL))
2086 gst_object_ref (peerpad);
2087 GST_OBJECT_UNLOCK (pad);
2089 result = gst_pad_get_caps (peerpad);
2091 gst_object_unref (peerpad);
2097 GST_OBJECT_UNLOCK (pad);
2103 fixate_value (GValue * dest, const GValue * src)
2105 if (G_VALUE_TYPE (src) == GST_TYPE_INT_RANGE) {
2106 g_value_init (dest, G_TYPE_INT);
2107 g_value_set_int (dest, gst_value_get_int_range_min (src));
2108 } else if (G_VALUE_TYPE (src) == GST_TYPE_DOUBLE_RANGE) {
2109 g_value_init (dest, G_TYPE_DOUBLE);
2110 g_value_set_double (dest, gst_value_get_double_range_min (src));
2111 } else if (G_VALUE_TYPE (src) == GST_TYPE_FRACTION_RANGE) {
2112 gst_value_init_and_copy (dest, gst_value_get_fraction_range_min (src));
2113 } else if (G_VALUE_TYPE (src) == GST_TYPE_LIST) {
2114 GValue temp = { 0 };
2116 gst_value_init_and_copy (&temp, gst_value_list_get_value (src, 0));
2117 if (!fixate_value (dest, &temp))
2118 gst_value_init_and_copy (dest, &temp);
2119 g_value_unset (&temp);
2120 } else if (G_VALUE_TYPE (src) == GST_TYPE_ARRAY) {
2121 gboolean res = FALSE;
2124 g_value_init (dest, GST_TYPE_ARRAY);
2125 for (n = 0; n < gst_value_array_get_size (src); n++) {
2127 const GValue *orig_kid = gst_value_array_get_value (src, n);
2129 if (!fixate_value (&kid, orig_kid))
2130 gst_value_init_and_copy (&kid, orig_kid);
2133 gst_value_array_append_value (dest, &kid);
2134 g_value_unset (&kid);
2138 g_value_unset (dest);
2149 gst_pad_default_fixate (GQuark field_id, const GValue * value, gpointer data)
2151 GstStructure *s = data;
2154 if (fixate_value (&v, value)) {
2155 gst_structure_id_set_value (s, field_id, &v);
2163 * gst_pad_fixate_caps:
2164 * @pad: a #GstPad to fixate
2165 * @caps: the #GstCaps to fixate
2167 * Fixate a caps on the given pad. Modifies the caps in place, so you should
2168 * make sure that the caps are actually writable (see gst_caps_make_writable()).
2171 gst_pad_fixate_caps (GstPad * pad, GstCaps * caps)
2173 GstPadFixateCapsFunction fixatefunc;
2176 g_return_if_fail (GST_IS_PAD (pad));
2177 g_return_if_fail (caps != NULL);
2179 if (gst_caps_is_fixed (caps))
2182 fixatefunc = GST_PAD_FIXATECAPSFUNC (pad);
2184 fixatefunc (pad, caps);
2187 /* default fixation */
2188 for (n = 0; n < gst_caps_get_size (caps); n++) {
2189 GstStructure *s = gst_caps_get_structure (caps, n);
2191 gst_structure_foreach (s, gst_pad_default_fixate, s);
2195 /* Default accept caps implementation just checks against
2196 * against the allowed caps for the pad */
2198 gst_pad_acceptcaps_default (GstPad * pad, GstCaps * caps)
2200 /* get the caps and see if it intersects to something
2204 gboolean result = FALSE;
2206 allowed = gst_pad_get_caps (pad);
2208 goto nothing_allowed;
2210 intersect = gst_caps_intersect (allowed, caps);
2212 result = !gst_caps_is_empty (intersect);
2214 GST_DEBUG_OBJECT (pad, "intersection gave empty caps");
2216 gst_caps_unref (allowed);
2217 gst_caps_unref (intersect);
2224 GST_DEBUG_OBJECT (pad, "no caps allowed on the pad");
2230 * gst_pad_accept_caps:
2231 * @pad: a #GstPad to check
2232 * @caps: a #GstCaps to check on the pad
2234 * Check if the given pad accepts the caps.
2236 * Returns: TRUE if the pad can accept the caps.
2239 gst_pad_accept_caps (GstPad * pad, GstCaps * caps)
2242 GstPadAcceptCapsFunction acceptfunc;
2243 GstCaps *existing = NULL;
2245 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2247 /* any pad can be unnegotiated */
2251 /* lock for checking the existing caps */
2252 GST_OBJECT_LOCK (pad);
2253 acceptfunc = GST_PAD_ACCEPTCAPSFUNC (pad);
2254 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "accept caps of %p", caps);
2255 /* The current caps on a pad are trivially acceptable */
2256 if (G_LIKELY ((existing = GST_PAD_CAPS (pad)))) {
2257 if (caps == existing || gst_caps_is_equal (caps, existing))
2260 GST_OBJECT_UNLOCK (pad);
2262 if (G_LIKELY (acceptfunc)) {
2263 /* we can call the function */
2264 result = acceptfunc (pad, caps);
2265 GST_DEBUG_OBJECT (pad, "acceptfunc returned %d", result);
2267 /* Only null if the element explicitly unset it */
2268 result = gst_pad_acceptcaps_default (pad, caps);
2269 GST_DEBUG_OBJECT (pad, "default acceptcaps returned %d", result);
2275 GST_DEBUG_OBJECT (pad, "pad had same caps");
2276 GST_OBJECT_UNLOCK (pad);
2282 * gst_pad_peer_accept_caps:
2283 * @pad: a #GstPad to check the peer of
2284 * @caps: a #GstCaps to check on the pad
2286 * Check if the peer of @pad accepts @caps. If @pad has no peer, this function
2289 * Returns: TRUE if the peer of @pad can accept the caps or @pad has no peer.
2292 gst_pad_peer_accept_caps (GstPad * pad, GstCaps * caps)
2297 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2299 GST_OBJECT_LOCK (pad);
2301 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "peer accept caps of (%p)", pad);
2303 peerpad = GST_PAD_PEER (pad);
2304 if (G_UNLIKELY (peerpad == NULL))
2307 result = gst_pad_accept_caps (peerpad, caps);
2308 GST_OBJECT_UNLOCK (pad);
2314 GST_OBJECT_UNLOCK (pad);
2321 * @pad: a #GstPad to set the capabilities of.
2322 * @caps: a #GstCaps to set.
2324 * Sets the capabilities of this pad. The caps must be fixed. Any previous
2325 * caps on the pad will be unreffed. This function refs the caps so you should
2326 * unref if as soon as you don't need it anymore.
2327 * It is possible to set NULL caps, which will make the pad unnegotiated
2330 * Returns: TRUE if the caps could be set. FALSE if the caps were not fixed
2331 * or bad parameters were provided to this function.
2336 gst_pad_set_caps (GstPad * pad, GstCaps * caps)
2338 GstPadSetCapsFunction setcaps;
2341 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2342 g_return_val_if_fail (caps == NULL || gst_caps_is_fixed (caps), FALSE);
2344 GST_OBJECT_LOCK (pad);
2345 existing = GST_PAD_CAPS (pad);
2346 if (existing == caps)
2349 if (gst_caps_is_equal (caps, existing))
2350 goto setting_same_caps;
2352 setcaps = GST_PAD_SETCAPSFUNC (pad);
2354 /* call setcaps function to configure the pad only if the
2355 * caps is not NULL */
2356 if (setcaps != NULL && caps) {
2357 if (!GST_PAD_IS_IN_SETCAPS (pad)) {
2358 GST_OBJECT_FLAG_SET (pad, GST_PAD_IN_SETCAPS);
2359 GST_OBJECT_UNLOCK (pad);
2360 if (!setcaps (pad, caps))
2362 GST_OBJECT_LOCK (pad);
2363 GST_OBJECT_FLAG_UNSET (pad, GST_PAD_IN_SETCAPS);
2365 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "pad was dispatching");
2369 gst_caps_replace (&GST_PAD_CAPS (pad), caps);
2370 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "caps %" GST_PTR_FORMAT, caps);
2371 GST_OBJECT_UNLOCK (pad);
2373 g_object_notify (G_OBJECT (pad), "caps");
2379 GST_OBJECT_UNLOCK (pad);
2384 gst_caps_replace (&GST_PAD_CAPS (pad), caps);
2385 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
2386 "caps %" GST_PTR_FORMAT " same as existing, updating ptr only", caps);
2387 GST_OBJECT_UNLOCK (pad);
2394 GST_OBJECT_LOCK (pad);
2395 GST_OBJECT_FLAG_UNSET (pad, GST_PAD_IN_SETCAPS);
2396 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
2397 "caps %" GST_PTR_FORMAT " could not be set", caps);
2398 GST_OBJECT_UNLOCK (pad);
2405 gst_pad_configure_sink (GstPad * pad, GstCaps * caps)
2407 GstPadSetCapsFunction setcaps;
2410 setcaps = GST_PAD_SETCAPSFUNC (pad);
2412 /* See if pad accepts the caps - only needed if
2413 * no setcaps function */
2414 if (setcaps == NULL)
2415 if (!gst_pad_accept_caps (pad, caps))
2418 /* set caps on pad if call succeeds */
2419 res = gst_pad_set_caps (pad, caps);
2420 /* no need to unref the caps here, set_caps takes a ref and
2421 * our ref goes away when we leave this function. */
2427 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
2428 "caps %" GST_PTR_FORMAT " not accepted", caps);
2433 /* returns TRUE if the src pad could be configured to accept the given caps */
2435 gst_pad_configure_src (GstPad * pad, GstCaps * caps, gboolean dosetcaps)
2437 GstPadSetCapsFunction setcaps;
2440 setcaps = GST_PAD_SETCAPSFUNC (pad);
2442 /* See if pad accepts the caps - only needed if
2443 * no setcaps function */
2444 if (setcaps == NULL)
2445 if (!gst_pad_accept_caps (pad, caps))
2449 res = gst_pad_set_caps (pad, caps);
2457 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
2458 "caps %" GST_PTR_FORMAT " not accepted", caps);
2464 * gst_pad_get_pad_template_caps:
2465 * @pad: a #GstPad to get the template capabilities from.
2467 * Gets the capabilities for @pad's template.
2469 * Returns: the #GstCaps of this pad template. If you intend to keep a
2470 * reference on the caps, make a copy (see gst_caps_copy ()).
2473 gst_pad_get_pad_template_caps (GstPad * pad)
2475 static GstStaticCaps anycaps = GST_STATIC_CAPS ("ANY");
2477 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2479 if (GST_PAD_PAD_TEMPLATE (pad))
2480 return GST_PAD_TEMPLATE_CAPS (GST_PAD_PAD_TEMPLATE (pad));
2482 return gst_static_caps_get (&anycaps);
2488 * @pad: a #GstPad to get the peer of.
2490 * Gets the peer of @pad. This function refs the peer pad so
2491 * you need to unref it after use.
2493 * Returns: the peer #GstPad. Unref after usage.
2498 gst_pad_get_peer (GstPad * pad)
2502 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2504 GST_OBJECT_LOCK (pad);
2505 result = GST_PAD_PEER (pad);
2507 gst_object_ref (result);
2508 GST_OBJECT_UNLOCK (pad);
2514 * gst_pad_get_allowed_caps:
2517 * Gets the capabilities of the allowed media types that can flow through
2518 * @pad and its peer.
2520 * The allowed capabilities is calculated as the intersection of the results of
2521 * calling gst_pad_get_caps() on @pad and its peer. The caller owns a reference
2522 * on the resulting caps.
2524 * Returns: the allowed #GstCaps of the pad link. Unref the caps when you no
2525 * longer need it. This function returns NULL when @pad has no peer.
2530 gst_pad_get_allowed_caps (GstPad * pad)
2537 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2539 GST_OBJECT_LOCK (pad);
2541 peer = GST_PAD_PEER (pad);
2542 if (G_UNLIKELY (peer == NULL))
2545 GST_CAT_DEBUG_OBJECT (GST_CAT_PROPERTIES, pad, "getting allowed caps");
2547 gst_object_ref (peer);
2548 GST_OBJECT_UNLOCK (pad);
2549 mycaps = gst_pad_get_caps (pad);
2551 peercaps = gst_pad_get_caps (peer);
2552 gst_object_unref (peer);
2554 caps = gst_caps_intersect (mycaps, peercaps);
2555 gst_caps_unref (peercaps);
2556 gst_caps_unref (mycaps);
2558 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "allowed caps %" GST_PTR_FORMAT,
2565 GST_CAT_DEBUG_OBJECT (GST_CAT_PROPERTIES, pad, "no peer");
2566 GST_OBJECT_UNLOCK (pad);
2573 * gst_pad_get_negotiated_caps:
2576 * Gets the capabilities of the media type that currently flows through @pad
2579 * This function can be used on both src and sinkpads. Note that srcpads are
2580 * always negotiated before sinkpads so it is possible that the negotiated caps
2581 * on the srcpad do not match the negotiated caps of the peer.
2583 * Returns: the negotiated #GstCaps of the pad link. Free the caps when
2584 * you no longer need it. This function returns NULL when the @pad has no
2585 * peer or is not negotiated yet.
2590 gst_pad_get_negotiated_caps (GstPad * pad)
2595 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2597 GST_OBJECT_LOCK (pad);
2599 if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
2602 GST_CAT_DEBUG_OBJECT (GST_CAT_PROPERTIES, pad, "getting negotiated caps");
2604 caps = GST_PAD_CAPS (pad);
2606 gst_caps_ref (caps);
2607 GST_OBJECT_UNLOCK (pad);
2609 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "negotiated caps %" GST_PTR_FORMAT,
2616 GST_CAT_DEBUG_OBJECT (GST_CAT_PROPERTIES, pad, "no peer");
2617 GST_OBJECT_UNLOCK (pad);
2623 /* calls the buffer_alloc function on the given pad */
2624 static GstFlowReturn
2625 gst_pad_buffer_alloc_unchecked (GstPad * pad, guint64 offset, gint size,
2626 GstCaps * caps, GstBuffer ** buf)
2629 GstPadBufferAllocFunction bufferallocfunc;
2631 GST_OBJECT_LOCK (pad);
2632 /* when the pad is flushing we cannot give a buffer */
2633 if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad)))
2636 bufferallocfunc = pad->bufferallocfunc;
2638 if (offset == GST_BUFFER_OFFSET_NONE) {
2639 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
2640 "calling bufferallocfunc &%s (@%p) for size %d offset NONE",
2641 GST_DEBUG_FUNCPTR_NAME (bufferallocfunc), bufferallocfunc, size);
2643 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
2644 "calling bufferallocfunc &%s (@%p) of for size %d offset %"
2645 G_GUINT64_FORMAT, GST_DEBUG_FUNCPTR_NAME (bufferallocfunc),
2646 bufferallocfunc, size, offset);
2648 GST_OBJECT_UNLOCK (pad);
2650 /* G_LIKELY for now since most elements don't implement a buffer alloc
2651 * function and there is no default alloc proxy function as this is usually
2653 if (G_LIKELY (bufferallocfunc == NULL))
2656 ret = bufferallocfunc (pad, offset, size, caps, buf);
2657 if (G_UNLIKELY (ret != GST_FLOW_OK))
2659 /* no error, but NULL buffer means fallback to the default */
2660 if (G_UNLIKELY (*buf == NULL))
2663 /* If the buffer alloc function didn't set up the caps like it should,
2665 if (G_UNLIKELY (caps && (GST_BUFFER_CAPS (*buf) == NULL))) {
2666 GST_WARNING_OBJECT (pad,
2667 "Buffer allocation function did not set caps. Setting");
2668 gst_buffer_set_caps (*buf, caps);
2674 /* pad was flushing */
2675 GST_OBJECT_UNLOCK (pad);
2676 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "pad was flushing");
2677 return GST_FLOW_WRONG_STATE;
2681 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
2682 "alloc function returned error (%d) %s", ret, gst_flow_get_name (ret));
2687 /* fallback case, allocate a buffer of our own, add pad caps. */
2688 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "fallback buffer alloc");
2690 *buf = gst_buffer_new_and_alloc (size);
2691 GST_BUFFER_OFFSET (*buf) = offset;
2692 gst_buffer_set_caps (*buf, caps);
2698 static GstFlowReturn
2699 gst_pad_alloc_buffer_full (GstPad * pad, guint64 offset, gint size,
2700 GstCaps * caps, GstBuffer ** buf, gboolean setcaps)
2704 gboolean caps_changed;
2706 g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
2707 g_return_val_if_fail (GST_PAD_IS_SRC (pad), GST_FLOW_ERROR);
2708 g_return_val_if_fail (buf != NULL, GST_FLOW_ERROR);
2710 GST_DEBUG_OBJECT (pad, "offset %" G_GUINT64_FORMAT ", size %d", offset, size);
2712 GST_OBJECT_LOCK (pad);
2713 while (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad)))
2714 if ((ret = handle_pad_block (pad)) != GST_FLOW_OK)
2717 if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
2720 gst_object_ref (peer);
2721 GST_OBJECT_UNLOCK (pad);
2723 ret = gst_pad_buffer_alloc_unchecked (peer, offset, size, caps, buf);
2724 gst_object_unref (peer);
2726 if (G_UNLIKELY (ret != GST_FLOW_OK))
2729 /* FIXME, move capnego this into a base class? */
2730 caps = GST_BUFFER_CAPS (*buf);
2732 /* Lock for checking caps, pretty pointless as the _pad_push() function might
2733 * change it concurrently, one of the problems with automatic caps setting in
2734 * pad_alloc_and_set_caps. Worst case, if does a check too much, but only
2735 * when there is heavy renegotiation going on in both directions. */
2736 GST_OBJECT_LOCK (pad);
2737 caps_changed = caps && caps != GST_PAD_CAPS (pad);
2738 GST_OBJECT_UNLOCK (pad);
2740 /* we got a new datatype on the pad, see if it can handle it */
2741 if (G_UNLIKELY (caps_changed)) {
2742 GST_DEBUG_OBJECT (pad, "caps changed to %p %" GST_PTR_FORMAT, caps, caps);
2743 if (G_UNLIKELY (!gst_pad_configure_src (pad, caps, setcaps)))
2744 goto not_negotiated;
2750 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "pad block stopped by flush");
2751 GST_OBJECT_UNLOCK (pad);
2756 /* pad has no peer */
2757 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
2758 "called bufferallocfunc but had no peer");
2759 GST_OBJECT_UNLOCK (pad);
2760 return GST_FLOW_NOT_LINKED;
2764 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
2765 "alloc function returned error %s", gst_flow_get_name (ret));
2770 gst_buffer_unref (*buf);
2772 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
2773 "alloc function returned unacceptable buffer");
2774 return GST_FLOW_NOT_NEGOTIATED;
2779 * gst_pad_alloc_buffer:
2780 * @pad: a source #GstPad
2781 * @offset: the offset of the new buffer in the stream
2782 * @size: the size of the new buffer
2783 * @caps: the caps of the new buffer
2784 * @buf: a newly allocated buffer
2786 * Allocates a new, empty buffer optimized to push to pad @pad. This
2787 * function only works if @pad is a source pad and has a peer.
2789 * A new, empty #GstBuffer will be put in the @buf argument.
2790 * You need to check the caps of the buffer after performing this
2791 * function and renegotiate to the format if needed.
2793 * Returns: a result code indicating success of the operation. Any
2794 * result code other than #GST_FLOW_OK is an error and @buf should
2796 * An error can occur if the pad is not connected or when the downstream
2797 * peer elements cannot provide an acceptable buffer.
2802 gst_pad_alloc_buffer (GstPad * pad, guint64 offset, gint size, GstCaps * caps,
2805 return gst_pad_alloc_buffer_full (pad, offset, size, caps, buf, FALSE);
2809 * gst_pad_alloc_buffer_and_set_caps:
2810 * @pad: a source #GstPad
2811 * @offset: the offset of the new buffer in the stream
2812 * @size: the size of the new buffer
2813 * @caps: the caps of the new buffer
2814 * @buf: a newly allocated buffer
2816 * In addition to the function gst_pad_alloc_buffer(), this function
2817 * automatically calls gst_pad_set_caps() when the caps of the
2818 * newly allocated buffer are different from the @pad caps.
2820 * Returns: a result code indicating success of the operation. Any
2821 * result code other than #GST_FLOW_OK is an error and @buf should
2823 * An error can occur if the pad is not connected or when the downstream
2824 * peer elements cannot provide an acceptable buffer.
2829 gst_pad_alloc_buffer_and_set_caps (GstPad * pad, guint64 offset, gint size,
2830 GstCaps * caps, GstBuffer ** buf)
2832 return gst_pad_alloc_buffer_full (pad, offset, size, caps, buf, TRUE);
2836 * gst_pad_get_internal_links_default:
2837 * @pad: the #GstPad to get the internal links of.
2839 * Gets a list of pads to which the given pad is linked to
2840 * inside of the parent element.
2841 * This is the default handler, and thus returns a list of all of the
2842 * pads inside the parent element with opposite direction.
2843 * The caller must free this list after use.
2845 * Returns: a newly allocated #GList of pads, or NULL if the pad has no parent.
2850 gst_pad_get_internal_links_default (GstPad * pad)
2855 GstPadDirection direction;
2857 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2859 direction = pad->direction;
2861 parent = GST_PAD_PARENT (pad);
2865 parent_pads = parent->pads;
2867 while (parent_pads) {
2868 GstPad *parent_pad = GST_PAD_CAST (parent_pads->data);
2870 if (parent_pad->direction != direction) {
2871 GST_DEBUG_OBJECT (pad, "adding pad %s:%s",
2872 GST_DEBUG_PAD_NAME (parent_pad));
2873 res = g_list_prepend (res, parent_pad);
2875 parent_pads = g_list_next (parent_pads);
2881 GST_DEBUG_OBJECT (pad, "no parent");
2887 * gst_pad_get_internal_links:
2888 * @pad: the #GstPad to get the internal links of.
2890 * Gets a list of pads to which the given pad is linked to
2891 * inside of the parent element.
2892 * The caller must free this list after use.
2894 * Returns: a newly allocated #GList of pads.
2899 gst_pad_get_internal_links (GstPad * pad)
2903 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2905 if (GST_PAD_INTLINKFUNC (pad))
2906 res = GST_PAD_INTLINKFUNC (pad) (pad);
2913 gst_pad_event_default_dispatch (GstPad * pad, GstEvent * event)
2918 GST_INFO_OBJECT (pad, "Sending event %p (%s) to all internally linked pads",
2919 event, GST_EVENT_TYPE_NAME (event));
2921 result = (GST_PAD_DIRECTION (pad) == GST_PAD_SINK);
2923 orig = pads = gst_pad_get_internal_links (pad);
2926 GstPad *eventpad = GST_PAD_CAST (pads->data);
2928 pads = g_list_next (pads);
2930 if (GST_PAD_DIRECTION (eventpad) == GST_PAD_SRC) {
2931 /* for each pad we send to, we should ref the event; it's up
2932 * to downstream to unref again when handled. */
2933 GST_LOG_OBJECT (pad, "Reffing and sending event %p (%s) to %s:%s",
2934 event, GST_EVENT_TYPE_NAME (event), GST_DEBUG_PAD_NAME (eventpad));
2935 gst_event_ref (event);
2936 gst_pad_push_event (eventpad, event);
2938 /* we only send the event on one pad, multi-sinkpad elements
2939 * should implement a handler */
2940 GST_LOG_OBJECT (pad, "sending event %p (%s) to one sink pad %s:%s",
2941 event, GST_EVENT_TYPE_NAME (event), GST_DEBUG_PAD_NAME (eventpad));
2942 result = gst_pad_push_event (eventpad, event);
2946 /* we handled the incoming event so we unref once */
2947 GST_LOG_OBJECT (pad, "handled event %p, unreffing", event);
2948 gst_event_unref (event);
2957 * gst_pad_event_default:
2958 * @pad: a #GstPad to call the default event handler on.
2959 * @event: the #GstEvent to handle.
2961 * Invokes the default event handler for the given pad. End-of-stream and
2962 * discontinuity events are handled specially, and then the event is sent to all
2963 * pads internally linked to @pad. Note that if there are many possible sink
2964 * pads that are internally linked to @pad, only one will be sent an event.
2965 * Multi-sinkpad elements should implement custom event handlers.
2967 * Returns: TRUE if the event was sent succesfully.
2970 gst_pad_event_default (GstPad * pad, GstEvent * event)
2972 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2973 g_return_val_if_fail (event != NULL, FALSE);
2975 switch (GST_EVENT_TYPE (event)) {
2978 GST_DEBUG_OBJECT (pad, "pausing task because of eos");
2979 gst_pad_pause_task (pad);
2986 return gst_pad_event_default_dispatch (pad, event);
2990 * gst_pad_dispatcher:
2991 * @pad: a #GstPad to dispatch.
2992 * @dispatch: the #GstDispatcherFunction to call.
2993 * @data: gpointer user data passed to the dispatcher function.
2995 * Invokes the given dispatcher function on each respective peer of
2996 * all pads that are internally linked to the given pad.
2997 * The GstPadDispatcherFunction should return TRUE when no further pads
2998 * need to be processed.
3000 * Returns: TRUE if one of the dispatcher functions returned TRUE.
3003 gst_pad_dispatcher (GstPad * pad, GstPadDispatcherFunction dispatch,
3006 gboolean res = FALSE;
3007 GList *int_pads, *orig;
3009 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
3010 g_return_val_if_fail (dispatch != NULL, FALSE);
3012 orig = int_pads = gst_pad_get_internal_links (pad);
3015 GstPad *int_pad = GST_PAD_CAST (int_pads->data);
3016 GstPad *int_peer = gst_pad_get_peer (int_pad);
3019 GST_DEBUG_OBJECT (int_pad, "dispatching to peer %s:%s",
3020 GST_DEBUG_PAD_NAME (int_peer));
3021 res = dispatch (int_peer, data);
3022 gst_object_unref (int_peer);
3026 GST_DEBUG_OBJECT (int_pad, "no peer");
3028 int_pads = g_list_next (int_pads);
3031 GST_DEBUG_OBJECT (pad, "done, result %d", res);
3038 * @pad: a #GstPad to invoke the default query on.
3039 * @query: the #GstQuery to perform.
3041 * Dispatches a query to a pad. The query should have been allocated by the
3042 * caller via one of the type-specific allocation functions in gstquery.h. The
3043 * element is responsible for filling the query with an appropriate response,
3044 * which should then be parsed with a type-specific query parsing function.
3046 * Again, the caller is responsible for both the allocation and deallocation of
3047 * the query structure.
3049 * Returns: TRUE if the query could be performed.
3052 gst_pad_query (GstPad * pad, GstQuery * query)
3054 GstPadQueryFunction func;
3056 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
3057 g_return_val_if_fail (GST_IS_QUERY (query), FALSE);
3059 GST_DEBUG_OBJECT (pad, "sending query %p", query);
3061 if ((func = GST_PAD_QUERYFUNC (pad)) == NULL)
3064 return func (pad, query);
3068 GST_DEBUG_OBJECT (pad, "had no query function");
3074 * gst_pad_query_default:
3075 * @pad: a #GstPad to call the default query handler on.
3076 * @query: the #GstQuery to handle.
3078 * Invokes the default query handler for the given pad.
3079 * The query is sent to all pads internally linked to @pad. Note that
3080 * if there are many possible sink pads that are internally linked to
3081 * @pad, only one will be sent the query.
3082 * Multi-sinkpad elements should implement custom query handlers.
3084 * Returns: TRUE if the query was performed succesfully.
3087 gst_pad_query_default (GstPad * pad, GstQuery * query)
3089 switch (GST_QUERY_TYPE (query)) {
3090 case GST_QUERY_POSITION:
3091 case GST_QUERY_SEEKING:
3092 case GST_QUERY_FORMATS:
3093 case GST_QUERY_LATENCY:
3094 case GST_QUERY_JITTER:
3095 case GST_QUERY_RATE:
3096 case GST_QUERY_CONVERT:
3098 return gst_pad_dispatcher
3099 (pad, (GstPadDispatcherFunction) gst_pad_query, query);
3103 #ifndef GST_DISABLE_LOADSAVE
3104 /* FIXME: why isn't this on a GstElement ? */
3106 * gst_pad_load_and_link:
3107 * @self: an #xmlNodePtr to read the description from.
3108 * @parent: the #GstObject element that owns the pad.
3110 * Reads the pad definition from the XML node and links the given pad
3111 * in the element to a pad of an element up in the hierarchy.
3114 gst_pad_load_and_link (xmlNodePtr self, GstObject * parent)
3116 xmlNodePtr field = self->xmlChildrenNode;
3117 GstPad *pad = NULL, *targetpad;
3121 GstObject *grandparent;
3125 if (!strcmp ((char *) field->name, "name")) {
3126 name = (gchar *) xmlNodeGetContent (field);
3127 pad = gst_element_get_pad (GST_ELEMENT (parent), name);
3129 } else if (!strcmp ((char *) field->name, "peer")) {
3130 peer = (gchar *) xmlNodeGetContent (field);
3132 field = field->next;
3134 g_return_if_fail (pad != NULL);
3139 split = g_strsplit (peer, ".", 2);
3141 if (split[0] == NULL || split[1] == NULL) {
3142 GST_CAT_DEBUG_OBJECT (GST_CAT_XML, pad,
3143 "Could not parse peer '%s', leaving unlinked", peer);
3150 g_return_if_fail (split[0] != NULL);
3151 g_return_if_fail (split[1] != NULL);
3153 grandparent = gst_object_get_parent (parent);
3155 if (grandparent && GST_IS_BIN (grandparent)) {
3156 target = gst_bin_get_by_name_recurse_up (GST_BIN (grandparent), split[0]);
3163 targetpad = gst_element_get_pad (target, split[1]);
3165 if (targetpad == NULL)
3168 gst_pad_link (pad, targetpad);
3175 * gst_pad_save_thyself:
3176 * @pad: a #GstPad to save.
3177 * @parent: the parent #xmlNodePtr to save the description in.
3179 * Saves the pad into an xml representation.
3181 * Returns: the #xmlNodePtr representation of the pad.
3184 gst_pad_save_thyself (GstObject * object, xmlNodePtr parent)
3189 g_return_val_if_fail (GST_IS_PAD (object), NULL);
3191 pad = GST_PAD (object);
3193 xmlNewChild (parent, NULL, (xmlChar *) "name",
3194 (xmlChar *) GST_PAD_NAME (pad));
3196 if (GST_PAD_IS_SRC (pad)) {
3197 xmlNewChild (parent, NULL, (xmlChar *) "direction", (xmlChar *) "source");
3198 } else if (GST_PAD_IS_SINK (pad)) {
3199 xmlNewChild (parent, NULL, (xmlChar *) "direction", (xmlChar *) "sink");
3201 xmlNewChild (parent, NULL, (xmlChar *) "direction", (xmlChar *) "unknown");
3204 if (GST_PAD_PEER (pad) != NULL) {
3207 peer = GST_PAD_PEER (pad);
3208 /* first check to see if the peer's parent's parent is the same */
3209 /* we just save it off */
3210 content = g_strdup_printf ("%s.%s",
3211 GST_OBJECT_NAME (GST_PAD_PARENT (peer)), GST_PAD_NAME (peer));
3212 xmlNewChild (parent, NULL, (xmlChar *) "peer", (xmlChar *) content);
3215 xmlNewChild (parent, NULL, (xmlChar *) "peer", NULL);
3222 * gst_ghost_pad_save_thyself:
3223 * @pad: a ghost #GstPad to save.
3224 * @parent: the parent #xmlNodePtr to save the description in.
3226 * Saves the ghost pad into an xml representation.
3228 * Returns: the #xmlNodePtr representation of the pad.
3231 gst_ghost_pad_save_thyself (GstPad * pad, xmlNodePtr parent)
3235 g_return_val_if_fail (GST_IS_GHOST_PAD (pad), NULL);
3237 self = xmlNewChild (parent, NULL, (xmlChar *) "ghostpad", NULL);
3238 xmlNewChild (self, NULL, (xmlChar *) "name", (xmlChar *) GST_PAD_NAME (pad));
3239 xmlNewChild (self, NULL, (xmlChar *) "parent",
3240 (xmlChar *) GST_OBJECT_NAME (GST_PAD_PARENT (pad)));
3242 /* FIXME FIXME FIXME! */
3247 #endif /* GST_DISABLE_LOADSAVE */
3250 * should be called with pad OBJECT_LOCK and STREAM_LOCK held.
3251 * GST_PAD_IS_BLOCKED (pad) == TRUE when this function is
3254 * This function performs the pad blocking when an event, buffer push
3255 * or buffer_alloc is performed on a _SRC_ pad. It blocks the
3256 * streaming thread after informing the pad has been blocked.
3258 * An application can with this method wait and block any streaming
3259 * thread and perform operations such as seeking or linking.
3261 * Two methods are available for notifying the application of the
3263 * - the callback method, which happens in the STREAMING thread with
3264 * the STREAM_LOCK held. With this method, the most useful way of
3265 * dealing with the callback is to post a message to the main thread
3266 * where the pad block can then be handled outside of the streaming
3267 * thread. With the last method one can perform all operations such
3268 * as doing a state change, linking, unblocking, seeking etc on the
3270 * - the GCond signal method, which makes any thread unblock when
3271 * the pad block happens.
3273 * During the actual blocking state, the GST_PAD_BLOCKING flag is set.
3274 * The GST_PAD_BLOCKING flag is unset when the pad was unblocked.
3278 static GstFlowReturn
3279 handle_pad_block (GstPad * pad)
3281 GstPadBlockCallback callback;
3283 GstFlowReturn ret = GST_FLOW_OK;
3285 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "signal block taken");
3287 /* flushing, don't bother trying to block and return WRONG_STATE
3289 if (GST_PAD_IS_FLUSHING (pad))
3290 goto flushingnonref;
3292 /* we grab an extra ref for the callbacks, this is probably not
3293 * needed (callback code does not have a ref and cannot unref). I
3294 * think this was done to make it possible to unref the element in
3295 * the callback, which is in the end totally impossible as it
3296 * requires grabbing the STREAM_LOCK and OBJECT_LOCK which are
3297 * all taken when calling this function. */
3298 gst_object_ref (pad);
3300 /* we either have a callback installed to notify the block or
3301 * some other thread is doing a GCond wait. */
3302 callback = pad->block_callback;
3304 /* there is a callback installed, call it. We release the
3305 * lock so that the callback can do something usefull with the
3307 user_data = pad->block_data;
3308 GST_OBJECT_UNLOCK (pad);
3309 callback (pad, TRUE, user_data);
3310 GST_OBJECT_LOCK (pad);
3312 /* we released the lock, recheck flushing */
3313 if (GST_PAD_IS_FLUSHING (pad))
3316 /* no callback, signal the thread that is doing a GCond wait
3318 GST_PAD_BLOCK_BROADCAST (pad);
3321 /* OBJECT_LOCK could have been released when we did the callback, which
3322 * then could have made the pad unblock so we need to check the blocking
3323 * condition again. */
3324 while (GST_PAD_IS_BLOCKED (pad)) {
3325 /* now we block the streaming thread. It can be unlocked when we
3326 * deactivate the pad (which will also set the FLUSHING flag) or
3327 * when the pad is unblocked. A flushing event will also unblock
3328 * the pad after setting the FLUSHING flag. */
3329 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3330 "Waiting to be unblocked or set flushing");
3331 GST_OBJECT_FLAG_SET (pad, GST_PAD_BLOCKING);
3332 GST_PAD_BLOCK_WAIT (pad);
3333 GST_OBJECT_FLAG_UNSET (pad, GST_PAD_BLOCKING);
3335 /* see if we got unblocked by a flush or not */
3336 if (GST_PAD_IS_FLUSHING (pad))
3340 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "got unblocked");
3342 /* when we get here, the pad is unblocked again and we perform
3343 * the needed unblock code. */
3344 callback = pad->block_callback;
3346 /* we need to call the callback */
3347 user_data = pad->block_data;
3348 GST_OBJECT_UNLOCK (pad);
3349 callback (pad, FALSE, user_data);
3350 GST_OBJECT_LOCK (pad);
3352 /* we need to signal the thread waiting on the GCond */
3353 GST_PAD_BLOCK_BROADCAST (pad);
3356 gst_object_unref (pad);
3362 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "pad was flushing");
3363 return GST_FLOW_WRONG_STATE;
3367 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "pad became flushing");
3368 gst_object_unref (pad);
3369 return GST_FLOW_WRONG_STATE;
3373 /**********************************************************************
3374 * Data passing functions
3378 gst_pad_emit_have_data_signal (GstPad * pad, GstMiniObject * obj)
3381 GValue args[2] = { {0}, {0} };
3386 g_value_init (&ret, G_TYPE_BOOLEAN);
3387 g_value_set_boolean (&ret, TRUE);
3388 g_value_init (&args[0], GST_TYPE_PAD);
3389 g_value_set_object (&args[0], pad);
3390 g_value_init (&args[1], GST_TYPE_MINI_OBJECT);
3391 gst_value_set_mini_object (&args[1], obj);
3393 if (GST_IS_EVENT (obj))
3394 detail = event_quark;
3396 detail = buffer_quark;
3399 g_signal_emitv (args, gst_pad_signals[PAD_HAVE_DATA], detail, &ret);
3400 res = g_value_get_boolean (&ret);
3403 g_value_unset (&ret);
3404 g_value_unset (&args[0]);
3405 g_value_unset (&args[1]);
3410 /* this is the chain function that does not perform the additional argument
3411 * checking for that little extra speed.
3413 static inline GstFlowReturn
3414 gst_pad_chain_unchecked (GstPad * pad, GstBuffer * buffer)
3417 gboolean caps_changed;
3418 GstPadChainFunction chainfunc;
3420 gboolean emit_signal;
3422 GST_PAD_STREAM_LOCK (pad);
3424 GST_OBJECT_LOCK (pad);
3425 if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad)))
3428 caps = GST_BUFFER_CAPS (buffer);
3429 caps_changed = caps && caps != GST_PAD_CAPS (pad);
3431 emit_signal = GST_PAD_DO_BUFFER_SIGNALS (pad) > 0;
3432 GST_OBJECT_UNLOCK (pad);
3434 /* see if the signal should be emited, we emit before caps nego as
3435 * we might drop the buffer and do capsnego for nothing. */
3436 if (G_UNLIKELY (emit_signal)) {
3437 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (buffer)))
3441 /* we got a new datatype on the pad, see if it can handle it */
3442 if (G_UNLIKELY (caps_changed)) {
3443 GST_DEBUG_OBJECT (pad, "caps changed to %p %" GST_PTR_FORMAT, caps, caps);
3444 if (G_UNLIKELY (!gst_pad_configure_sink (pad, caps)))
3445 goto not_negotiated;
3448 /* NOTE: we read the chainfunc unlocked.
3449 * we cannot hold the lock for the pad so we might send
3450 * the data to the wrong function. This is not really a
3451 * problem since functions are assigned at creation time
3452 * and don't change that often... */
3453 if (G_UNLIKELY ((chainfunc = GST_PAD_CHAINFUNC (pad)) == NULL))
3456 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3457 "calling chainfunction &%s", GST_DEBUG_FUNCPTR_NAME (chainfunc));
3459 ret = chainfunc (pad, buffer);
3461 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3462 "called chainfunction &%s, returned %s",
3463 GST_DEBUG_FUNCPTR_NAME (chainfunc), gst_flow_get_name (ret));
3465 GST_PAD_STREAM_UNLOCK (pad);
3472 gst_buffer_unref (buffer);
3473 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3474 "pushing, but pad was flushing");
3475 GST_OBJECT_UNLOCK (pad);
3476 GST_PAD_STREAM_UNLOCK (pad);
3477 return GST_FLOW_WRONG_STATE;
3481 gst_buffer_unref (buffer);
3482 GST_DEBUG_OBJECT (pad, "Dropping buffer due to FALSE probe return");
3483 GST_PAD_STREAM_UNLOCK (pad);
3488 gst_buffer_unref (buffer);
3489 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3490 "pushing buffer but pad did not accept");
3491 GST_PAD_STREAM_UNLOCK (pad);
3492 return GST_FLOW_NOT_NEGOTIATED;
3496 gst_buffer_unref (buffer);
3497 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3498 "pushing, but not chainhandler");
3499 GST_ELEMENT_ERROR (GST_PAD_PARENT (pad), CORE, PAD, (NULL),
3500 ("push on pad %s:%s but it has no chainfunction",
3501 GST_DEBUG_PAD_NAME (pad)));
3502 GST_PAD_STREAM_UNLOCK (pad);
3503 return GST_FLOW_NOT_SUPPORTED;
3509 * @pad: a sink #GstPad, returns GST_FLOW_ERROR if not.
3510 * @buffer: the #GstBuffer to send, return GST_FLOW_ERROR if not.
3512 * Chain a buffer to @pad.
3514 * The function returns #GST_FLOW_WRONG_STATE if the pad was flushing.
3516 * If the caps on @buffer are different from the current caps on @pad, this
3517 * function will call any setcaps function (see gst_pad_set_setcaps_function())
3518 * installed on @pad. If the new caps are not acceptable for @pad, this
3519 * function returns #GST_FLOW_NOT_NEGOTIATED.
3521 * The function proceeds calling the chain function installed on @pad (see
3522 * gst_pad_set_chain_function()) and the return value of that function is
3523 * returned to the caller. #GST_FLOW_NOT_SUPPORTED is returned if @pad has no
3526 * In all cases, success or failure, the caller loses its reference to @buffer
3527 * after calling this function.
3529 * Returns: a #GstFlowReturn from the pad.
3534 gst_pad_chain (GstPad * pad, GstBuffer * buffer)
3536 g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
3537 g_return_val_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SINK,
3539 g_return_val_if_fail (GST_IS_BUFFER (buffer), GST_FLOW_ERROR);
3541 return gst_pad_chain_unchecked (pad, buffer);
3546 * @pad: a source #GstPad, returns #GST_FLOW_ERROR if not.
3547 * @buffer: the #GstBuffer to push returns GST_FLOW_ERROR if not.
3549 * Pushes a buffer to the peer of @pad.
3551 * This function will call an installed pad block before triggering any
3552 * installed pad probes.
3554 * If the caps on @buffer are different from the currently configured caps on
3555 * @pad, this function will call any installed setcaps function on @pad (see
3556 * gst_pad_set_setcaps_function()). In case of failure to renegotiate the new
3557 * format, this function returns #GST_FLOW_NOT_NEGOTIATED.
3559 * The function proceeds calling gst_pad_chain() on the peer pad and returns
3560 * the value from that function. If @pad has no peer, #GST_FLOW_NOT_LINKED will
3563 * In all cases, success or failure, the caller loses its reference to @buffer
3564 * after calling this function.
3566 * Returns: a #GstFlowReturn from the peer pad.
3571 gst_pad_push (GstPad * pad, GstBuffer * buffer)
3577 gboolean caps_changed;
3579 g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
3580 g_return_val_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SRC, GST_FLOW_ERROR);
3581 g_return_val_if_fail (GST_IS_BUFFER (buffer), GST_FLOW_ERROR);
3583 GST_OBJECT_LOCK (pad);
3585 /* FIXME: this check can go away; pad_set_blocked could be implemented with
3586 * probes completely or probes with an extended pad block. */
3587 while (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad)))
3588 if ((ret = handle_pad_block (pad)) != GST_FLOW_OK)
3591 /* we emit signals on the pad arg, the peer will have a chance to
3592 * emit in the _chain() function */
3593 if (G_UNLIKELY (GST_PAD_DO_BUFFER_SIGNALS (pad) > 0)) {
3594 /* unlock before emitting */
3595 GST_OBJECT_UNLOCK (pad);
3597 /* if the signal handler returned FALSE, it means we should just drop the
3599 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (buffer)))
3602 GST_OBJECT_LOCK (pad);
3605 if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
3608 /* take ref to peer pad before releasing the lock */
3609 gst_object_ref (peer);
3611 /* Before pushing the buffer to the peer pad, ensure that caps
3612 * are set on this pad */
3613 caps = GST_BUFFER_CAPS (buffer);
3614 caps_changed = caps && caps != GST_PAD_CAPS (pad);
3616 GST_OBJECT_UNLOCK (pad);
3618 /* we got a new datatype from the pad, it had better handle it */
3619 if (G_UNLIKELY (caps_changed)) {
3620 GST_DEBUG_OBJECT (pad, "caps changed to %p %" GST_PTR_FORMAT, caps, caps);
3621 if (G_UNLIKELY (!gst_pad_configure_src (pad, caps, TRUE)))
3622 goto not_negotiated;
3625 ret = gst_pad_chain_unchecked (peer, buffer);
3627 gst_object_unref (peer);
3631 /* ERROR recovery here */
3634 gst_buffer_unref (buffer);
3635 GST_DEBUG_OBJECT (pad, "pad block stopped by flush");
3636 GST_OBJECT_UNLOCK (pad);
3641 gst_buffer_unref (buffer);
3642 GST_DEBUG_OBJECT (pad, "Dropping buffer due to FALSE probe return");
3647 gst_buffer_unref (buffer);
3648 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3649 "pushing, but it was not linked");
3650 GST_OBJECT_UNLOCK (pad);
3651 return GST_FLOW_NOT_LINKED;
3655 gst_buffer_unref (buffer);
3656 gst_object_unref (peer);
3657 GST_CAT_DEBUG_OBJECT (GST_CAT_SCHEDULING, pad,
3658 "element pushed buffer then refused to accept the caps");
3659 return GST_FLOW_NOT_NEGOTIATED;
3664 * gst_pad_check_pull_range:
3665 * @pad: a sink #GstPad.
3667 * Checks if a gst_pad_pull_range() can be performed on the peer
3668 * source pad. This function is used by plugins that want to check
3669 * if they can use random access on the peer source pad.
3671 * The peer sourcepad can implement a custom #GstPadCheckGetRangeFunction
3672 * if it needs to perform some logic to determine if pull_range is
3675 * Returns: a gboolean with the result.
3680 gst_pad_check_pull_range (GstPad * pad)
3684 GstPadCheckGetRangeFunction checkgetrangefunc;
3686 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
3688 GST_OBJECT_LOCK (pad);
3689 if (GST_PAD_DIRECTION (pad) != GST_PAD_SINK)
3690 goto wrong_direction;
3692 if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
3695 gst_object_ref (peer);
3696 GST_OBJECT_UNLOCK (pad);
3698 /* see note in above function */
3699 if (G_LIKELY ((checkgetrangefunc = peer->checkgetrangefunc) == NULL)) {
3700 /* FIXME, kindoff ghetto */
3701 ret = GST_PAD_GETRANGEFUNC (peer) != NULL;
3702 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3703 "no checkgetrangefunc, assuming %d", ret);
3705 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3706 "calling checkgetrangefunc %s of peer pad %s:%s",
3707 GST_DEBUG_FUNCPTR_NAME (checkgetrangefunc), GST_DEBUG_PAD_NAME (peer));
3709 ret = checkgetrangefunc (peer);
3712 gst_object_unref (peer);
3716 /* ERROR recovery here */
3719 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3720 "checking pull range, but pad must be a sinkpad");
3721 GST_OBJECT_UNLOCK (pad);
3726 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3727 "checking pull range, but it was not linked");
3728 GST_OBJECT_UNLOCK (pad);
3734 * gst_pad_get_range:
3735 * @pad: a src #GstPad, returns #GST_FLOW_ERROR if not.
3736 * @offset: The start offset of the buffer
3737 * @size: The length of the buffer
3738 * @buffer: a pointer to hold the #GstBuffer, returns #GST_FLOW_ERROR if %NULL.
3740 * When @pad is flushing this function returns #GST_FLOW_WRONG_STATE
3743 * Calls the getrange function of @pad, see #GstPadGetRangeFunction for a
3744 * description of a getrange function. If @pad has no getrange function
3745 * installed (see gst_pad_set_getrange_function()) this function returns
3746 * #GST_FLOW_NOT_SUPPORTED.
3748 * @buffer's caps must either be unset or the same as what is already
3749 * configured on @pad. Renegotiation within a running pull-mode pipeline is not
3752 * This is a lowlevel function. Usualy gst_pad_pull_range() is used.
3754 * Returns: a #GstFlowReturn from the pad.
3759 gst_pad_get_range (GstPad * pad, guint64 offset, guint size,
3760 GstBuffer ** buffer)
3763 GstPadGetRangeFunction getrangefunc;
3764 gboolean emit_signal;
3766 g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
3767 g_return_val_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SRC, GST_FLOW_ERROR);
3768 g_return_val_if_fail (buffer != NULL, GST_FLOW_ERROR);
3770 GST_PAD_STREAM_LOCK (pad);
3772 GST_OBJECT_LOCK (pad);
3773 if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad)))
3776 emit_signal = GST_PAD_DO_BUFFER_SIGNALS (pad) > 0;
3777 GST_OBJECT_UNLOCK (pad);
3779 if (G_UNLIKELY ((getrangefunc = GST_PAD_GETRANGEFUNC (pad)) == NULL))
3782 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3783 "calling getrangefunc %s, offset %"
3784 G_GUINT64_FORMAT ", size %u",
3785 GST_DEBUG_FUNCPTR_NAME (getrangefunc), offset, size);
3787 ret = getrangefunc (pad, offset, size, buffer);
3789 /* can only fire the signal if we have a valid buffer */
3790 if (G_UNLIKELY (emit_signal) && (ret == GST_FLOW_OK)) {
3791 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (*buffer)))
3795 GST_PAD_STREAM_UNLOCK (pad);
3797 if (G_LIKELY (ret == GST_FLOW_OK)) {
3799 gboolean caps_changed;
3801 GST_OBJECT_LOCK (pad);
3802 /* Before pushing the buffer to the peer pad, ensure that caps
3803 * are set on this pad */
3804 caps = GST_BUFFER_CAPS (*buffer);
3805 caps_changed = caps && caps != GST_PAD_CAPS (pad);
3806 GST_OBJECT_UNLOCK (pad);
3808 /* we got a new datatype from the pad not supported in a running pull-mode
3810 if (G_UNLIKELY (caps_changed))
3811 goto not_negotiated;
3819 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3820 "pulling range, but pad was flushing");
3821 GST_OBJECT_UNLOCK (pad);
3822 GST_PAD_STREAM_UNLOCK (pad);
3823 return GST_FLOW_WRONG_STATE;
3827 GST_ELEMENT_ERROR (GST_PAD_PARENT (pad), CORE, PAD, (NULL),
3828 ("pullrange on pad %s:%s but it has no getrangefunction",
3829 GST_DEBUG_PAD_NAME (pad)));
3830 GST_PAD_STREAM_UNLOCK (pad);
3831 return GST_FLOW_NOT_SUPPORTED;
3835 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3836 "Dropping data after FALSE probe return");
3837 GST_PAD_STREAM_UNLOCK (pad);
3838 gst_buffer_unref (*buffer);
3840 return GST_FLOW_UNEXPECTED;
3844 /* ideally we want to use the commented-out code, but currently demuxers
3845 * and typefind do not follow part-negotiation.txt. When switching into
3846 * pull mode, typefind should probably return the found caps from
3847 * getcaps(), and demuxers should do the setcaps(). */
3850 gst_buffer_unref (*buffer);
3852 GST_CAT_WARNING_OBJECT (GST_CAT_SCHEDULING, pad,
3853 "getrange returned buffer of different caps");
3854 return GST_FLOW_NOT_NEGOTIATED;
3856 GST_CAT_DEBUG_OBJECT (GST_CAT_SCHEDULING, pad,
3857 "getrange returned buffer of different caps");
3864 * gst_pad_pull_range:
3865 * @pad: a sink #GstPad, returns GST_FLOW_ERROR if not.
3866 * @offset: The start offset of the buffer
3867 * @size: The length of the buffer
3868 * @buffer: a pointer to hold the #GstBuffer, returns GST_FLOW_ERROR if %NULL.
3870 * Pulls a @buffer from the peer pad.
3872 * This function will first trigger the pad block signal if it was
3875 * When @pad is not linked #GST_FLOW_NOT_LINKED is returned else this
3876 * function returns the result of gst_pad_get_range() on the peer pad.
3877 * See gst_pad_get_range() for a list of return values and for the
3878 * semantics of the arguments of this function.
3880 * @buffer's caps must either be unset or the same as what is already
3881 * configured on @pad. Renegotiation within a running pull-mode pipeline is not
3884 * Returns: a #GstFlowReturn from the peer pad.
3885 * When this function returns #GST_FLOW_OK, @buffer will contain a valid
3886 * #GstBuffer that should be freed with gst_buffer_unref() after usage.
3887 * @buffer may not be used or freed when any other return value than
3888 * #GST_FLOW_OK is returned.
3893 gst_pad_pull_range (GstPad * pad, guint64 offset, guint size,
3894 GstBuffer ** buffer)
3898 gboolean emit_signal;
3900 g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
3901 g_return_val_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SINK,
3903 g_return_val_if_fail (buffer != NULL, GST_FLOW_ERROR);
3905 GST_OBJECT_LOCK (pad);
3907 while (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad)))
3908 handle_pad_block (pad);
3910 if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
3913 /* signal emision for the pad, peer has chance to emit when
3914 * we call _get_range() */
3915 emit_signal = GST_PAD_DO_BUFFER_SIGNALS (pad) > 0;
3917 gst_object_ref (peer);
3918 GST_OBJECT_UNLOCK (pad);
3920 ret = gst_pad_get_range (peer, offset, size, buffer);
3922 gst_object_unref (peer);
3924 /* can only fire the signal if we have a valid buffer */
3925 if (G_UNLIKELY (emit_signal) && (ret == GST_FLOW_OK)) {
3926 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (*buffer)))
3930 if (G_LIKELY (ret == GST_FLOW_OK)) {
3932 gboolean caps_changed;
3934 GST_OBJECT_LOCK (pad);
3935 /* Before pushing the buffer to the peer pad, ensure that caps
3936 * are set on this pad */
3937 caps = GST_BUFFER_CAPS (*buffer);
3938 caps_changed = caps && caps != GST_PAD_CAPS (pad);
3939 GST_OBJECT_UNLOCK (pad);
3941 /* we got a new datatype on the pad, see if it can handle it */
3942 if (G_UNLIKELY (caps_changed))
3943 goto not_negotiated;
3948 /* ERROR recovery here */
3951 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3952 "pulling range, but it was not linked");
3953 GST_OBJECT_UNLOCK (pad);
3954 return GST_FLOW_NOT_LINKED;
3958 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3959 "Dropping data after FALSE probe return");
3960 gst_buffer_unref (*buffer);
3962 return GST_FLOW_UNEXPECTED;
3966 /* ideally we want to use the commented-out code, but currently demuxers
3967 * and typefind do not follow part-negotiation.txt. When switching into
3968 * pull mode, typefind should probably return the found caps from
3969 * getcaps(), and demuxers should do the setcaps(). */
3972 gst_buffer_unref (*buffer);
3974 GST_CAT_WARNING_OBJECT (GST_CAT_SCHEDULING, pad,
3975 "pullrange returned buffer of different caps");
3976 return GST_FLOW_NOT_NEGOTIATED;
3978 GST_CAT_DEBUG_OBJECT (GST_CAT_SCHEDULING, pad,
3979 "pullrange returned buffer of different caps");
3985 * gst_pad_push_event:
3986 * @pad: a #GstPad to push the event to.
3987 * @event: the #GstEvent to send to the pad.
3989 * Sends the event to the peer of the given pad. This function is
3990 * mainly used by elements to send events to their peer
3993 * This function takes owership of the provided event so you should
3994 * gst_event_ref() it if you want to reuse the event after this call.
3996 * Returns: TRUE if the event was handled.
4001 gst_pad_push_event (GstPad * pad, GstEvent * event)
4006 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
4007 g_return_val_if_fail (event != NULL, FALSE);
4008 g_return_val_if_fail (GST_IS_EVENT (event), FALSE);
4010 GST_LOG_OBJECT (pad, "event: %s", GST_EVENT_TYPE_NAME (event));
4012 GST_OBJECT_LOCK (pad);
4014 /* Two checks to be made:
4015 * . (un)set the FLUSHING flag for flushing events,
4016 * . handle pad blocking */
4017 switch (GST_EVENT_TYPE (event)) {
4018 case GST_EVENT_FLUSH_START:
4019 GST_PAD_SET_FLUSHING (pad);
4021 if (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad))) {
4022 /* flush start will have set the FLUSHING flag and will then
4023 * unlock all threads doing a GCond wait on the blocking pad. This
4024 * will typically unblock the STREAMING thread blocked on a pad. */
4025 GST_LOG_OBJECT (pad, "Pad is blocked, not forwarding flush-start, "
4026 "doing block signal.");
4027 GST_PAD_BLOCK_BROADCAST (pad);
4031 case GST_EVENT_FLUSH_STOP:
4032 GST_PAD_UNSET_FLUSHING (pad);
4034 /* if we are blocked, flush away the FLUSH_STOP event */
4035 if (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad))) {
4036 GST_LOG_OBJECT (pad, "Pad is blocked, not forwarding flush-stop");
4041 while (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad))) {
4042 /* block the event as long as the pad is blocked */
4043 if (handle_pad_block (pad) != GST_FLOW_OK)
4049 if (G_UNLIKELY (GST_PAD_DO_EVENT_SIGNALS (pad) > 0)) {
4050 GST_OBJECT_UNLOCK (pad);
4052 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (event)))
4055 GST_OBJECT_LOCK (pad);
4057 peerpad = GST_PAD_PEER (pad);
4058 if (peerpad == NULL)
4061 GST_LOG_OBJECT (pad, "sending event %s to peerpad %" GST_PTR_FORMAT,
4062 GST_EVENT_TYPE_NAME (event), peerpad);
4063 gst_object_ref (peerpad);
4064 GST_OBJECT_UNLOCK (pad);
4066 result = gst_pad_send_event (peerpad, event);
4068 /* Note: we gave away ownership of the event at this point */
4069 GST_LOG_OBJECT (pad, "sent event to peerpad %" GST_PTR_FORMAT, peerpad);
4070 gst_object_unref (peerpad);
4074 /* ERROR handling */
4077 GST_DEBUG_OBJECT (pad, "Dropping event after FALSE probe return");
4078 gst_event_unref (event);
4083 GST_DEBUG_OBJECT (pad, "Dropping event because pad is not linked");
4084 gst_event_unref (event);
4085 GST_OBJECT_UNLOCK (pad);
4090 GST_DEBUG_OBJECT (pad,
4091 "Not forwarding event since we're flushing and blocking");
4092 gst_event_unref (event);
4093 GST_OBJECT_UNLOCK (pad);
4099 * gst_pad_send_event:
4100 * @pad: a #GstPad to send the event to.
4101 * @event: the #GstEvent to send to the pad.
4103 * Sends the event to the pad. This function can be used
4104 * by applications to send events in the pipeline.
4106 * If @pad is a source pad, @event should be an upstream event. If @pad is a
4107 * sink pad, @event should be a downstream event. For example, you would not
4108 * send a #GST_EVENT_EOS on a src pad; EOS events only propagate downstream.
4109 * Furthermore, some downstream events have to be serialized with data flow,
4110 * like EOS, while some can travel out-of-band, like #GST_EVENT_FLUSH_START. If
4111 * the event needs to be serialized with data flow, this function will take the
4112 * pad's stream lock while calling its event function.
4114 * To find out whether an event type is upstream, downstream, or downstream and
4115 * serialized, see #GstEventTypeFlags, gst_event_type_get_flags(),
4116 * #GST_EVENT_IS_UPSTREAM, #GST_EVENT_IS_DOWNSTREAM, and
4117 * #GST_EVENT_IS_SERIALIZED. Note that in practice that an application or
4118 * plugin doesn't need to bother itself with this information; the core handles
4119 * all necessary locks and checks.
4121 * This function takes owership of the provided event so you should
4122 * gst_event_ref() it if you want to reuse the event after this call.
4124 * Returns: TRUE if the event was handled.
4127 gst_pad_send_event (GstPad * pad, GstEvent * event)
4129 gboolean result = FALSE;
4130 GstPadEventFunction eventfunc;
4131 gboolean serialized, need_unlock = FALSE;
4133 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
4134 g_return_val_if_fail (event != NULL, FALSE);
4136 GST_OBJECT_LOCK (pad);
4137 if (GST_PAD_IS_SINK (pad)) {
4138 if (G_UNLIKELY (!GST_EVENT_IS_DOWNSTREAM (event)))
4139 goto wrong_direction;
4140 serialized = GST_EVENT_IS_SERIALIZED (event);
4141 } else if (GST_PAD_IS_SRC (pad)) {
4142 if (G_UNLIKELY (!GST_EVENT_IS_UPSTREAM (event)))
4143 goto wrong_direction;
4144 /* events on srcpad never are serialized */
4147 goto unknown_direction;
4149 if (G_UNLIKELY (GST_EVENT_SRC (event) == NULL)) {
4150 GST_LOG_OBJECT (pad, "event had no source, setting pad as event source");
4151 GST_EVENT_SRC (event) = gst_object_ref (pad);
4155 if (G_UNLIKELY (GST_PAD_DO_EVENT_SIGNALS (pad) > 0)) {
4156 GST_OBJECT_UNLOCK (pad);
4158 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT_CAST (event)))
4161 GST_OBJECT_LOCK (pad);
4164 switch (GST_EVENT_TYPE (event)) {
4165 case GST_EVENT_FLUSH_START:
4166 GST_CAT_DEBUG_OBJECT (GST_CAT_EVENT, pad,
4167 "have event type %d (FLUSH_START)", GST_EVENT_TYPE (event));
4169 /* can't even accept a flush begin event when flushing */
4170 if (GST_PAD_IS_FLUSHING (pad))
4172 GST_PAD_SET_FLUSHING (pad);
4173 GST_CAT_DEBUG_OBJECT (GST_CAT_EVENT, pad, "set flush flag");
4175 case GST_EVENT_FLUSH_STOP:
4176 GST_PAD_UNSET_FLUSHING (pad);
4177 GST_CAT_DEBUG_OBJECT (GST_CAT_EVENT, pad, "cleared flush flag");
4178 GST_OBJECT_UNLOCK (pad);
4179 /* grab stream lock */
4180 GST_PAD_STREAM_LOCK (pad);
4182 GST_OBJECT_LOCK (pad);
4185 GST_CAT_DEBUG_OBJECT (GST_CAT_EVENT, pad, "have event type %s",
4186 GST_EVENT_TYPE_NAME (event));
4188 /* make this a little faster, no point in grabbing the lock
4189 * if the pad is allready flushing. */
4190 if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad)))
4194 /* lock order: STREAM_LOCK, LOCK, recheck flushing. */
4195 GST_OBJECT_UNLOCK (pad);
4196 GST_PAD_STREAM_LOCK (pad);
4198 GST_OBJECT_LOCK (pad);
4199 if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad)))
4204 if (G_UNLIKELY ((eventfunc = GST_PAD_EVENTFUNC (pad)) == NULL))
4207 GST_OBJECT_UNLOCK (pad);
4209 result = eventfunc (pad, event);
4212 GST_PAD_STREAM_UNLOCK (pad);
4216 /* ERROR handling */
4219 g_warning ("pad %s:%s sending %s event in wrong direction",
4220 GST_DEBUG_PAD_NAME (pad), GST_EVENT_TYPE_NAME (event));
4221 GST_OBJECT_UNLOCK (pad);
4222 gst_event_unref (event);
4227 g_warning ("pad %s:%s has invalid direction", GST_DEBUG_PAD_NAME (pad));
4228 GST_OBJECT_UNLOCK (pad);
4229 gst_event_unref (event);
4234 g_warning ("pad %s:%s has no event handler, file a bug.",
4235 GST_DEBUG_PAD_NAME (pad));
4236 GST_OBJECT_UNLOCK (pad);
4238 GST_PAD_STREAM_UNLOCK (pad);
4239 gst_event_unref (event);
4244 GST_OBJECT_UNLOCK (pad);
4246 GST_PAD_STREAM_UNLOCK (pad);
4247 GST_CAT_INFO_OBJECT (GST_CAT_EVENT, pad,
4248 "Received event on flushing pad. Discarding");
4249 gst_event_unref (event);
4254 GST_DEBUG_OBJECT (pad, "Dropping event after FALSE probe return");
4255 gst_event_unref (event);
4261 * gst_pad_set_element_private:
4262 * @pad: the #GstPad to set the private data of.
4263 * @priv: The private data to attach to the pad.
4265 * Set the given private data gpointer on the pad.
4266 * This function can only be used by the element that owns the pad.
4267 * No locking is performed in this function.
4270 gst_pad_set_element_private (GstPad * pad, gpointer priv)
4272 pad->element_private = priv;
4276 * gst_pad_get_element_private:
4277 * @pad: the #GstPad to get the private data of.
4279 * Gets the private data of a pad.
4280 * No locking is performed in this function.
4282 * Returns: a #gpointer to the private data.
4285 gst_pad_get_element_private (GstPad * pad)
4287 return pad->element_private;
4291 * gst_pad_start_task:
4292 * @pad: the #GstPad to start the task of
4293 * @func: the task function to call
4294 * @data: data passed to the task function
4296 * Starts a task that repeatedly calls @func with @data. This function
4297 * is mostly used in pad activation functions to start the dataflow.
4298 * The #GST_PAD_STREAM_LOCK of @pad will automatically be acquired
4299 * before @func is called.
4301 * Returns: a %TRUE if the task could be started.
4304 gst_pad_start_task (GstPad * pad, GstTaskFunction func, gpointer data)
4308 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
4309 g_return_val_if_fail (func != NULL, FALSE);
4311 GST_DEBUG_OBJECT (pad, "start task");
4313 GST_OBJECT_LOCK (pad);
4314 task = GST_PAD_TASK (pad);
4316 task = gst_task_create (func, data);
4317 gst_task_set_lock (task, GST_PAD_GET_STREAM_LOCK (pad));
4318 GST_PAD_TASK (pad) = task;
4319 GST_DEBUG_OBJECT (pad, "created task");
4321 gst_task_start (task);
4322 GST_OBJECT_UNLOCK (pad);
4328 * gst_pad_pause_task:
4329 * @pad: the #GstPad to pause the task of
4331 * Pause the task of @pad. This function will also make sure that the
4332 * function executed by the task will effectively stop.
4334 * Returns: a TRUE if the task could be paused or FALSE when the pad
4338 gst_pad_pause_task (GstPad * pad)
4342 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
4344 GST_DEBUG_OBJECT (pad, "pause task");
4346 GST_OBJECT_LOCK (pad);
4347 task = GST_PAD_TASK (pad);
4350 gst_task_pause (task);
4351 GST_OBJECT_UNLOCK (pad);
4353 GST_PAD_STREAM_LOCK (pad);
4354 GST_PAD_STREAM_UNLOCK (pad);
4360 GST_DEBUG_OBJECT (pad, "pad has no task");
4361 GST_OBJECT_UNLOCK (pad);
4367 * gst_pad_stop_task:
4368 * @pad: the #GstPad to stop the task of
4370 * Stop the task of @pad. This function will also make sure that the
4371 * function executed by the task will effectively stop if not called
4372 * from the GstTaskFunction.
4374 * This function will deadlock if called from the GstTaskFunction of
4375 * the task. Use gst_task_pause() instead.
4377 * Regardless of whether the pad has a task, the stream lock is acquired and
4378 * released so as to ensure that streaming through this pad has finished.
4380 * Returns: a TRUE if the task could be stopped or FALSE on error.
4383 gst_pad_stop_task (GstPad * pad)
4387 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
4389 GST_DEBUG_OBJECT (pad, "stop task");
4391 GST_OBJECT_LOCK (pad);
4392 task = GST_PAD_TASK (pad);
4395 GST_PAD_TASK (pad) = NULL;
4396 gst_task_stop (task);
4397 GST_OBJECT_UNLOCK (pad);
4399 GST_PAD_STREAM_LOCK (pad);
4400 GST_PAD_STREAM_UNLOCK (pad);
4402 if (!gst_task_join (task))
4405 gst_object_unref (task);
4411 GST_DEBUG_OBJECT (pad, "no task");
4412 GST_OBJECT_UNLOCK (pad);
4414 GST_PAD_STREAM_LOCK (pad);
4415 GST_PAD_STREAM_UNLOCK (pad);
4417 /* this is not an error */
4422 /* this is bad, possibly the application tried to join the task from
4423 * the task's thread. We install the task again so that it will be stopped
4424 * again from the right thread next time hopefully. */
4425 GST_OBJECT_LOCK (pad);
4426 GST_DEBUG_OBJECT (pad, "join failed");
4427 /* we can only install this task if there was no other task */
4428 if (GST_PAD_TASK (pad) == NULL)
4429 GST_PAD_TASK (pad) = task;
4430 GST_OBJECT_UNLOCK (pad);