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;
1957 GstPadTemplate *templ;
1959 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "get pad caps");
1961 if (GST_PAD_GETCAPSFUNC (pad)) {
1962 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
1963 "dispatching to pad getcaps function");
1965 GST_OBJECT_FLAG_SET (pad, GST_PAD_IN_GETCAPS);
1966 GST_OBJECT_UNLOCK (pad);
1967 result = GST_PAD_GETCAPSFUNC (pad) (pad);
1968 GST_OBJECT_LOCK (pad);
1969 GST_OBJECT_FLAG_UNSET (pad, GST_PAD_IN_GETCAPS);
1971 if (result == NULL) {
1972 g_critical ("pad %s:%s returned NULL caps from getcaps function",
1973 GST_DEBUG_PAD_NAME (pad));
1975 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
1976 "pad getcaps returned %" GST_PTR_FORMAT, result);
1977 #ifndef G_DISABLE_ASSERT
1978 /* check that the returned caps are a real subset of the template caps */
1979 if (GST_PAD_PAD_TEMPLATE (pad)) {
1980 const GstCaps *templ_caps =
1981 GST_PAD_TEMPLATE_CAPS (GST_PAD_PAD_TEMPLATE (pad));
1982 if (!gst_caps_is_subset (result, templ_caps)) {
1985 GST_CAT_ERROR_OBJECT (GST_CAT_CAPS, pad,
1986 "pad returned caps %" GST_PTR_FORMAT
1987 " which are not a real subset of its template caps %"
1988 GST_PTR_FORMAT, result, templ_caps);
1990 ("pad %s:%s returned caps which are not a real "
1991 "subset of its template caps", GST_DEBUG_PAD_NAME (pad));
1992 temp = gst_caps_intersect (templ_caps, result);
1993 gst_caps_unref (result);
2001 if ((templ = GST_PAD_PAD_TEMPLATE (pad))) {
2002 result = GST_PAD_TEMPLATE_CAPS (templ);
2003 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
2004 "using pad template %p with caps %p %" GST_PTR_FORMAT, templ, result,
2007 result = gst_caps_ref (result);
2010 if ((result = GST_PAD_CAPS (pad))) {
2011 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
2012 "using pad caps %p %" GST_PTR_FORMAT, result, result);
2014 result = gst_caps_ref (result);
2018 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "pad has no caps");
2019 result = gst_caps_new_empty ();
2027 * @pad: a #GstPad to get the capabilities of.
2029 * Gets the capabilities this pad can produce or consume.
2030 * Note that this method doesn't necessarily return the caps set by
2031 * gst_pad_set_caps() - use #GST_PAD_CAPS for that instead.
2032 * gst_pad_get_caps returns all possible caps a pad can operate with, using
2033 * the pad's get_caps function;
2034 * this returns the pad template caps if not explicitly set.
2036 * Returns: a newly allocated copy of the #GstCaps of this pad.
2041 gst_pad_get_caps (GstPad * pad)
2043 GstCaps *result = NULL;
2045 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2047 GST_OBJECT_LOCK (pad);
2049 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "get pad caps");
2051 result = gst_pad_get_caps_unlocked (pad);
2052 GST_OBJECT_UNLOCK (pad);
2058 * gst_pad_peer_get_caps:
2059 * @pad: a #GstPad to get the peer capabilities of.
2061 * Gets the capabilities of the peer connected to this pad.
2063 * Returns: the #GstCaps of the peer pad. This function returns a new caps, so
2064 * use gst_caps_unref to get rid of it. this function returns NULL if there is
2068 gst_pad_peer_get_caps (GstPad * pad)
2071 GstCaps *result = NULL;
2073 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2075 GST_OBJECT_LOCK (pad);
2077 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "get peer caps");
2079 peerpad = GST_PAD_PEER (pad);
2080 if (G_UNLIKELY (peerpad == NULL))
2083 gst_object_ref (peerpad);
2084 GST_OBJECT_UNLOCK (pad);
2086 result = gst_pad_get_caps (peerpad);
2088 gst_object_unref (peerpad);
2094 GST_OBJECT_UNLOCK (pad);
2100 fixate_value (GValue * dest, const GValue * src)
2102 if (G_VALUE_TYPE (src) == GST_TYPE_INT_RANGE) {
2103 g_value_init (dest, G_TYPE_INT);
2104 g_value_set_int (dest, gst_value_get_int_range_min (src));
2105 } else if (G_VALUE_TYPE (src) == GST_TYPE_DOUBLE_RANGE) {
2106 g_value_init (dest, G_TYPE_DOUBLE);
2107 g_value_set_double (dest, gst_value_get_double_range_min (src));
2108 } else if (G_VALUE_TYPE (src) == GST_TYPE_FRACTION_RANGE) {
2109 gst_value_init_and_copy (dest, gst_value_get_fraction_range_min (src));
2110 } else if (G_VALUE_TYPE (src) == GST_TYPE_LIST) {
2111 GValue temp = { 0 };
2113 gst_value_init_and_copy (&temp, gst_value_list_get_value (src, 0));
2114 if (!fixate_value (dest, &temp))
2115 gst_value_init_and_copy (dest, &temp);
2116 g_value_unset (&temp);
2117 } else if (G_VALUE_TYPE (src) == GST_TYPE_ARRAY) {
2118 gboolean res = FALSE;
2121 g_value_init (dest, GST_TYPE_ARRAY);
2122 for (n = 0; n < gst_value_array_get_size (src); n++) {
2124 const GValue *orig_kid = gst_value_array_get_value (src, n);
2126 if (!fixate_value (&kid, orig_kid))
2127 gst_value_init_and_copy (&kid, orig_kid);
2130 gst_value_array_append_value (dest, &kid);
2131 g_value_unset (&kid);
2135 g_value_unset (dest);
2146 gst_pad_default_fixate (GQuark field_id, const GValue * value, gpointer data)
2148 GstStructure *s = data;
2151 if (fixate_value (&v, value)) {
2152 gst_structure_id_set_value (s, field_id, &v);
2160 * gst_pad_fixate_caps:
2161 * @pad: a #GstPad to fixate
2162 * @caps: the #GstCaps to fixate
2164 * Fixate a caps on the given pad. Modifies the caps in place, so you should
2165 * make sure that the caps are actually writable (see gst_caps_make_writable()).
2168 gst_pad_fixate_caps (GstPad * pad, GstCaps * caps)
2170 GstPadFixateCapsFunction fixatefunc;
2173 g_return_if_fail (GST_IS_PAD (pad));
2174 g_return_if_fail (caps != NULL);
2176 if (gst_caps_is_fixed (caps))
2179 fixatefunc = GST_PAD_FIXATECAPSFUNC (pad);
2181 fixatefunc (pad, caps);
2184 /* default fixation */
2185 for (n = 0; n < gst_caps_get_size (caps); n++) {
2186 GstStructure *s = gst_caps_get_structure (caps, n);
2188 gst_structure_foreach (s, gst_pad_default_fixate, s);
2192 /* Default accept caps implementation just checks against
2193 * against the allowed caps for the pad */
2195 gst_pad_acceptcaps_default (GstPad * pad, GstCaps * caps)
2197 /* get the caps and see if it intersects to something
2201 gboolean result = FALSE;
2203 GST_DEBUG_OBJECT (pad, "caps %" GST_PTR_FORMAT, caps);
2205 allowed = gst_pad_get_caps (pad);
2207 goto nothing_allowed;
2209 GST_DEBUG_OBJECT (pad, "allowed caps %" GST_PTR_FORMAT, allowed);
2211 intersect = gst_caps_intersect (allowed, caps);
2213 GST_DEBUG_OBJECT (pad, "intersection %" GST_PTR_FORMAT, intersect);
2215 result = !gst_caps_is_empty (intersect);
2217 GST_DEBUG_OBJECT (pad, "intersection gave empty caps");
2219 gst_caps_unref (allowed);
2220 gst_caps_unref (intersect);
2227 GST_DEBUG_OBJECT (pad, "no caps allowed on the pad");
2233 * gst_pad_accept_caps:
2234 * @pad: a #GstPad to check
2235 * @caps: a #GstCaps to check on the pad
2237 * Check if the given pad accepts the caps.
2239 * Returns: TRUE if the pad can accept the caps.
2242 gst_pad_accept_caps (GstPad * pad, GstCaps * caps)
2245 GstPadAcceptCapsFunction acceptfunc;
2246 GstCaps *existing = NULL;
2248 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2250 /* any pad can be unnegotiated */
2254 /* lock for checking the existing caps */
2255 GST_OBJECT_LOCK (pad);
2256 acceptfunc = GST_PAD_ACCEPTCAPSFUNC (pad);
2257 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "accept caps of %p", caps);
2258 /* The current caps on a pad are trivially acceptable */
2259 if (G_LIKELY ((existing = GST_PAD_CAPS (pad)))) {
2260 if (caps == existing || gst_caps_is_equal (caps, existing))
2263 GST_OBJECT_UNLOCK (pad);
2265 if (G_LIKELY (acceptfunc)) {
2266 /* we can call the function */
2267 result = acceptfunc (pad, caps);
2268 GST_DEBUG_OBJECT (pad, "acceptfunc returned %d", result);
2270 /* Only null if the element explicitly unset it */
2271 result = gst_pad_acceptcaps_default (pad, caps);
2272 GST_DEBUG_OBJECT (pad, "default acceptcaps returned %d", result);
2278 GST_DEBUG_OBJECT (pad, "pad had same caps");
2279 GST_OBJECT_UNLOCK (pad);
2285 * gst_pad_peer_accept_caps:
2286 * @pad: a #GstPad to check the peer of
2287 * @caps: a #GstCaps to check on the pad
2289 * Check if the peer of @pad accepts @caps. If @pad has no peer, this function
2292 * Returns: TRUE if the peer of @pad can accept the caps or @pad has no peer.
2295 gst_pad_peer_accept_caps (GstPad * pad, GstCaps * caps)
2300 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2302 GST_OBJECT_LOCK (pad);
2304 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "peer accept caps of (%p)", pad);
2306 peerpad = GST_PAD_PEER (pad);
2307 if (G_UNLIKELY (peerpad == NULL))
2310 result = gst_pad_accept_caps (peerpad, caps);
2311 GST_OBJECT_UNLOCK (pad);
2317 GST_OBJECT_UNLOCK (pad);
2324 * @pad: a #GstPad to set the capabilities of.
2325 * @caps: a #GstCaps to set.
2327 * Sets the capabilities of this pad. The caps must be fixed. Any previous
2328 * caps on the pad will be unreffed. This function refs the caps so you should
2329 * unref if as soon as you don't need it anymore.
2330 * It is possible to set NULL caps, which will make the pad unnegotiated
2333 * Returns: TRUE if the caps could be set. FALSE if the caps were not fixed
2334 * or bad parameters were provided to this function.
2339 gst_pad_set_caps (GstPad * pad, GstCaps * caps)
2341 GstPadSetCapsFunction setcaps;
2344 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2345 g_return_val_if_fail (caps == NULL || gst_caps_is_fixed (caps), FALSE);
2347 GST_OBJECT_LOCK (pad);
2348 existing = GST_PAD_CAPS (pad);
2349 if (existing == caps)
2352 if (gst_caps_is_equal (caps, existing))
2353 goto setting_same_caps;
2355 setcaps = GST_PAD_SETCAPSFUNC (pad);
2357 /* call setcaps function to configure the pad only if the
2358 * caps is not NULL */
2359 if (setcaps != NULL && caps) {
2360 if (!GST_PAD_IS_IN_SETCAPS (pad)) {
2361 GST_OBJECT_FLAG_SET (pad, GST_PAD_IN_SETCAPS);
2362 GST_OBJECT_UNLOCK (pad);
2363 if (!setcaps (pad, caps))
2365 GST_OBJECT_LOCK (pad);
2366 GST_OBJECT_FLAG_UNSET (pad, GST_PAD_IN_SETCAPS);
2368 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "pad was dispatching");
2372 gst_caps_replace (&GST_PAD_CAPS (pad), caps);
2373 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "caps %" GST_PTR_FORMAT, caps);
2374 GST_OBJECT_UNLOCK (pad);
2376 g_object_notify (G_OBJECT (pad), "caps");
2382 GST_OBJECT_UNLOCK (pad);
2387 gst_caps_replace (&GST_PAD_CAPS (pad), caps);
2388 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
2389 "caps %" GST_PTR_FORMAT " same as existing, updating ptr only", caps);
2390 GST_OBJECT_UNLOCK (pad);
2397 GST_OBJECT_LOCK (pad);
2398 GST_OBJECT_FLAG_UNSET (pad, GST_PAD_IN_SETCAPS);
2399 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
2400 "caps %" GST_PTR_FORMAT " could not be set", caps);
2401 GST_OBJECT_UNLOCK (pad);
2408 gst_pad_configure_sink (GstPad * pad, GstCaps * caps)
2412 /* See if pad accepts the caps */
2413 if (!gst_pad_accept_caps (pad, caps))
2416 /* set caps on pad if call succeeds */
2417 res = gst_pad_set_caps (pad, caps);
2418 /* no need to unref the caps here, set_caps takes a ref and
2419 * our ref goes away when we leave this function. */
2425 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
2426 "caps %" GST_PTR_FORMAT " not accepted", caps);
2431 /* returns TRUE if the src pad could be configured to accept the given caps */
2433 gst_pad_configure_src (GstPad * pad, GstCaps * caps, gboolean dosetcaps)
2437 /* See if pad accepts the caps */
2438 if (!gst_pad_accept_caps (pad, caps))
2442 res = gst_pad_set_caps (pad, caps);
2450 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
2451 "caps %" GST_PTR_FORMAT " not accepted", caps);
2457 * gst_pad_get_pad_template_caps:
2458 * @pad: a #GstPad to get the template capabilities from.
2460 * Gets the capabilities for @pad's template.
2462 * Returns: the #GstCaps of this pad template. If you intend to keep a
2463 * reference on the caps, make a copy (see gst_caps_copy ()).
2466 gst_pad_get_pad_template_caps (GstPad * pad)
2468 static GstStaticCaps anycaps = GST_STATIC_CAPS ("ANY");
2470 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2472 if (GST_PAD_PAD_TEMPLATE (pad))
2473 return GST_PAD_TEMPLATE_CAPS (GST_PAD_PAD_TEMPLATE (pad));
2475 return gst_static_caps_get (&anycaps);
2480 * @pad: a #GstPad to get the peer of.
2482 * Gets the peer of @pad. This function refs the peer pad so
2483 * you need to unref it after use.
2485 * Returns: the peer #GstPad. Unref after usage.
2490 gst_pad_get_peer (GstPad * pad)
2494 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2496 GST_OBJECT_LOCK (pad);
2497 result = GST_PAD_PEER (pad);
2499 gst_object_ref (result);
2500 GST_OBJECT_UNLOCK (pad);
2506 * gst_pad_get_allowed_caps:
2509 * Gets the capabilities of the allowed media types that can flow through
2510 * @pad and its peer.
2512 * The allowed capabilities is calculated as the intersection of the results of
2513 * calling gst_pad_get_caps() on @pad and its peer. The caller owns a reference
2514 * on the resulting caps.
2516 * Returns: the allowed #GstCaps of the pad link. Unref the caps when you no
2517 * longer need it. This function returns NULL when @pad has no peer.
2522 gst_pad_get_allowed_caps (GstPad * pad)
2529 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2531 GST_OBJECT_LOCK (pad);
2533 peer = GST_PAD_PEER (pad);
2534 if (G_UNLIKELY (peer == NULL))
2537 GST_CAT_DEBUG_OBJECT (GST_CAT_PROPERTIES, pad, "getting allowed caps");
2539 gst_object_ref (peer);
2540 GST_OBJECT_UNLOCK (pad);
2541 mycaps = gst_pad_get_caps (pad);
2543 peercaps = gst_pad_get_caps (peer);
2544 gst_object_unref (peer);
2546 caps = gst_caps_intersect (mycaps, peercaps);
2547 gst_caps_unref (peercaps);
2548 gst_caps_unref (mycaps);
2550 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "allowed caps %" GST_PTR_FORMAT,
2557 GST_CAT_DEBUG_OBJECT (GST_CAT_PROPERTIES, pad, "no peer");
2558 GST_OBJECT_UNLOCK (pad);
2565 * gst_pad_get_negotiated_caps:
2568 * Gets the capabilities of the media type that currently flows through @pad
2571 * This function can be used on both src and sinkpads. Note that srcpads are
2572 * always negotiated before sinkpads so it is possible that the negotiated caps
2573 * on the srcpad do not match the negotiated caps of the peer.
2575 * Returns: the negotiated #GstCaps of the pad link. Unref the caps when
2576 * you no longer need it. This function returns NULL when the @pad has no
2577 * peer or is not negotiated yet.
2582 gst_pad_get_negotiated_caps (GstPad * pad)
2587 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2589 GST_OBJECT_LOCK (pad);
2591 if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
2594 GST_CAT_DEBUG_OBJECT (GST_CAT_PROPERTIES, pad, "getting negotiated caps");
2596 caps = GST_PAD_CAPS (pad);
2598 gst_caps_ref (caps);
2599 GST_OBJECT_UNLOCK (pad);
2601 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "negotiated caps %" GST_PTR_FORMAT,
2608 GST_CAT_DEBUG_OBJECT (GST_CAT_PROPERTIES, pad, "no peer");
2609 GST_OBJECT_UNLOCK (pad);
2615 /* calls the buffer_alloc function on the given pad */
2616 static GstFlowReturn
2617 gst_pad_buffer_alloc_unchecked (GstPad * pad, guint64 offset, gint size,
2618 GstCaps * caps, GstBuffer ** buf)
2621 GstPadBufferAllocFunction bufferallocfunc;
2623 GST_OBJECT_LOCK (pad);
2624 /* when the pad is flushing we cannot give a buffer */
2625 if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad)))
2628 bufferallocfunc = pad->bufferallocfunc;
2630 if (offset == GST_BUFFER_OFFSET_NONE) {
2631 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
2632 "calling bufferallocfunc &%s (@%p) for size %d offset NONE",
2633 GST_DEBUG_FUNCPTR_NAME (bufferallocfunc), bufferallocfunc, size);
2635 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
2636 "calling bufferallocfunc &%s (@%p) of for size %d offset %"
2637 G_GUINT64_FORMAT, GST_DEBUG_FUNCPTR_NAME (bufferallocfunc),
2638 bufferallocfunc, size, offset);
2640 GST_OBJECT_UNLOCK (pad);
2642 /* G_LIKELY for now since most elements don't implement a buffer alloc
2643 * function and there is no default alloc proxy function as this is usually
2645 if (G_LIKELY (bufferallocfunc == NULL))
2648 ret = bufferallocfunc (pad, offset, size, caps, buf);
2649 if (G_UNLIKELY (ret != GST_FLOW_OK))
2651 /* no error, but NULL buffer means fallback to the default */
2652 if (G_UNLIKELY (*buf == NULL))
2655 /* If the buffer alloc function didn't set up the caps like it should,
2657 if (G_UNLIKELY (caps && (GST_BUFFER_CAPS (*buf) == NULL))) {
2658 GST_WARNING_OBJECT (pad,
2659 "Buffer allocation function did not set caps. Setting");
2660 gst_buffer_set_caps (*buf, caps);
2666 /* pad was flushing */
2667 GST_OBJECT_UNLOCK (pad);
2668 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "pad was flushing");
2669 return GST_FLOW_WRONG_STATE;
2673 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
2674 "alloc function returned error (%d) %s", ret, gst_flow_get_name (ret));
2679 /* fallback case, allocate a buffer of our own, add pad caps. */
2680 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "fallback buffer alloc");
2682 *buf = gst_buffer_new_and_alloc (size);
2683 GST_BUFFER_OFFSET (*buf) = offset;
2684 gst_buffer_set_caps (*buf, caps);
2690 static GstFlowReturn
2691 gst_pad_alloc_buffer_full (GstPad * pad, guint64 offset, gint size,
2692 GstCaps * caps, GstBuffer ** buf, gboolean setcaps)
2696 gboolean caps_changed;
2698 g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
2699 g_return_val_if_fail (GST_PAD_IS_SRC (pad), GST_FLOW_ERROR);
2700 g_return_val_if_fail (buf != NULL, GST_FLOW_ERROR);
2702 GST_DEBUG_OBJECT (pad, "offset %" G_GUINT64_FORMAT ", size %d", offset, size);
2704 GST_OBJECT_LOCK (pad);
2705 while (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad)))
2706 if ((ret = handle_pad_block (pad)) != GST_FLOW_OK)
2709 if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
2712 gst_object_ref (peer);
2713 GST_OBJECT_UNLOCK (pad);
2715 ret = gst_pad_buffer_alloc_unchecked (peer, offset, size, caps, buf);
2716 gst_object_unref (peer);
2718 if (G_UNLIKELY (ret != GST_FLOW_OK))
2721 /* FIXME, move capnego this into a base class? */
2722 caps = GST_BUFFER_CAPS (*buf);
2724 /* Lock for checking caps, pretty pointless as the _pad_push() function might
2725 * change it concurrently, one of the problems with automatic caps setting in
2726 * pad_alloc_and_set_caps. Worst case, if does a check too much, but only
2727 * when there is heavy renegotiation going on in both directions. */
2728 GST_OBJECT_LOCK (pad);
2729 caps_changed = caps && caps != GST_PAD_CAPS (pad);
2730 GST_OBJECT_UNLOCK (pad);
2732 /* we got a new datatype on the pad, see if it can handle it */
2733 if (G_UNLIKELY (caps_changed)) {
2734 GST_DEBUG_OBJECT (pad,
2735 "caps changed from %" GST_PTR_FORMAT " to %p %" GST_PTR_FORMAT,
2736 GST_PAD_CAPS (pad), caps, caps);
2737 if (G_UNLIKELY (!gst_pad_configure_src (pad, caps, setcaps)))
2738 goto not_negotiated;
2744 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "pad block stopped by flush");
2745 GST_OBJECT_UNLOCK (pad);
2750 /* pad has no peer */
2751 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
2752 "called bufferallocfunc but had no peer");
2753 GST_OBJECT_UNLOCK (pad);
2754 return GST_FLOW_NOT_LINKED;
2758 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
2759 "alloc function returned error %s", gst_flow_get_name (ret));
2764 gst_buffer_unref (*buf);
2766 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
2767 "alloc function returned unacceptable buffer");
2768 return GST_FLOW_NOT_NEGOTIATED;
2773 * gst_pad_alloc_buffer:
2774 * @pad: a source #GstPad
2775 * @offset: the offset of the new buffer in the stream
2776 * @size: the size of the new buffer
2777 * @caps: the caps of the new buffer
2778 * @buf: a newly allocated buffer
2780 * Allocates a new, empty buffer optimized to push to pad @pad. This
2781 * function only works if @pad is a source pad and has a peer.
2783 * A new, empty #GstBuffer will be put in the @buf argument.
2784 * You need to check the caps of the buffer after performing this
2785 * function and renegotiate to the format if needed.
2787 * Returns: a result code indicating success of the operation. Any
2788 * result code other than #GST_FLOW_OK is an error and @buf should
2790 * An error can occur if the pad is not connected or when the downstream
2791 * peer elements cannot provide an acceptable buffer.
2796 gst_pad_alloc_buffer (GstPad * pad, guint64 offset, gint size, GstCaps * caps,
2799 return gst_pad_alloc_buffer_full (pad, offset, size, caps, buf, FALSE);
2803 * gst_pad_alloc_buffer_and_set_caps:
2804 * @pad: a source #GstPad
2805 * @offset: the offset of the new buffer in the stream
2806 * @size: the size of the new buffer
2807 * @caps: the caps of the new buffer
2808 * @buf: a newly allocated buffer
2810 * In addition to the function gst_pad_alloc_buffer(), this function
2811 * automatically calls gst_pad_set_caps() when the caps of the
2812 * newly allocated buffer are different from the @pad caps.
2814 * Returns: a result code indicating success of the operation. Any
2815 * result code other than #GST_FLOW_OK is an error and @buf should
2817 * An error can occur if the pad is not connected or when the downstream
2818 * peer elements cannot provide an acceptable buffer.
2823 gst_pad_alloc_buffer_and_set_caps (GstPad * pad, guint64 offset, gint size,
2824 GstCaps * caps, GstBuffer ** buf)
2826 return gst_pad_alloc_buffer_full (pad, offset, size, caps, buf, TRUE);
2830 * gst_pad_get_internal_links_default:
2831 * @pad: the #GstPad to get the internal links of.
2833 * Gets a list of pads to which the given pad is linked to
2834 * inside of the parent element.
2835 * This is the default handler, and thus returns a list of all of the
2836 * pads inside the parent element with opposite direction.
2837 * The caller must free this list after use.
2839 * Returns: a newly allocated #GList of pads, or NULL if the pad has no parent.
2844 gst_pad_get_internal_links_default (GstPad * pad)
2849 GstPadDirection direction;
2851 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2853 direction = pad->direction;
2855 parent = GST_PAD_PARENT (pad);
2859 parent_pads = parent->pads;
2861 while (parent_pads) {
2862 GstPad *parent_pad = GST_PAD_CAST (parent_pads->data);
2864 if (parent_pad->direction != direction) {
2865 GST_DEBUG_OBJECT (pad, "adding pad %s:%s",
2866 GST_DEBUG_PAD_NAME (parent_pad));
2867 res = g_list_prepend (res, parent_pad);
2869 parent_pads = g_list_next (parent_pads);
2875 GST_DEBUG_OBJECT (pad, "no parent");
2881 * gst_pad_get_internal_links:
2882 * @pad: the #GstPad to get the internal links of.
2884 * Gets a list of pads to which the given pad is linked to
2885 * inside of the parent element.
2886 * The caller must free this list after use.
2888 * Returns: a newly allocated #GList of pads.
2893 gst_pad_get_internal_links (GstPad * pad)
2897 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2899 if (GST_PAD_INTLINKFUNC (pad))
2900 res = GST_PAD_INTLINKFUNC (pad) (pad);
2907 gst_pad_event_default_dispatch (GstPad * pad, GstEvent * event)
2912 GST_INFO_OBJECT (pad, "Sending event %p (%s) to all internally linked pads",
2913 event, GST_EVENT_TYPE_NAME (event));
2915 result = (GST_PAD_DIRECTION (pad) == GST_PAD_SINK);
2917 orig = pads = gst_pad_get_internal_links (pad);
2920 GstPad *eventpad = GST_PAD_CAST (pads->data);
2922 pads = g_list_next (pads);
2924 if (GST_PAD_DIRECTION (eventpad) == GST_PAD_SRC) {
2925 /* for each pad we send to, we should ref the event; it's up
2926 * to downstream to unref again when handled. */
2927 GST_LOG_OBJECT (pad, "Reffing and sending event %p (%s) to %s:%s",
2928 event, GST_EVENT_TYPE_NAME (event), GST_DEBUG_PAD_NAME (eventpad));
2929 gst_event_ref (event);
2930 gst_pad_push_event (eventpad, event);
2932 /* we only send the event on one pad, multi-sinkpad elements
2933 * should implement a handler */
2934 GST_LOG_OBJECT (pad, "sending event %p (%s) to one sink pad %s:%s",
2935 event, GST_EVENT_TYPE_NAME (event), GST_DEBUG_PAD_NAME (eventpad));
2936 result = gst_pad_push_event (eventpad, event);
2940 /* we handled the incoming event so we unref once */
2941 GST_LOG_OBJECT (pad, "handled event %p, unreffing", event);
2942 gst_event_unref (event);
2951 * gst_pad_event_default:
2952 * @pad: a #GstPad to call the default event handler on.
2953 * @event: the #GstEvent to handle.
2955 * Invokes the default event handler for the given pad. End-of-stream and
2956 * discontinuity events are handled specially, and then the event is sent to all
2957 * pads internally linked to @pad. Note that if there are many possible sink
2958 * pads that are internally linked to @pad, only one will be sent an event.
2959 * Multi-sinkpad elements should implement custom event handlers.
2961 * Returns: TRUE if the event was sent succesfully.
2964 gst_pad_event_default (GstPad * pad, GstEvent * event)
2966 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2967 g_return_val_if_fail (event != NULL, FALSE);
2969 switch (GST_EVENT_TYPE (event)) {
2972 GST_DEBUG_OBJECT (pad, "pausing task because of eos");
2973 gst_pad_pause_task (pad);
2980 return gst_pad_event_default_dispatch (pad, event);
2984 * gst_pad_dispatcher:
2985 * @pad: a #GstPad to dispatch.
2986 * @dispatch: the #GstDispatcherFunction to call.
2987 * @data: gpointer user data passed to the dispatcher function.
2989 * Invokes the given dispatcher function on each respective peer of
2990 * all pads that are internally linked to the given pad.
2991 * The GstPadDispatcherFunction should return TRUE when no further pads
2992 * need to be processed.
2994 * Returns: TRUE if one of the dispatcher functions returned TRUE.
2997 gst_pad_dispatcher (GstPad * pad, GstPadDispatcherFunction dispatch,
3000 gboolean res = FALSE;
3001 GList *int_pads, *orig;
3003 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
3004 g_return_val_if_fail (dispatch != NULL, FALSE);
3006 orig = int_pads = gst_pad_get_internal_links (pad);
3009 GstPad *int_pad = GST_PAD_CAST (int_pads->data);
3010 GstPad *int_peer = gst_pad_get_peer (int_pad);
3013 GST_DEBUG_OBJECT (int_pad, "dispatching to peer %s:%s",
3014 GST_DEBUG_PAD_NAME (int_peer));
3015 res = dispatch (int_peer, data);
3016 gst_object_unref (int_peer);
3020 GST_DEBUG_OBJECT (int_pad, "no peer");
3022 int_pads = g_list_next (int_pads);
3025 GST_DEBUG_OBJECT (pad, "done, result %d", res);
3032 * @pad: a #GstPad to invoke the default query on.
3033 * @query: the #GstQuery to perform.
3035 * Dispatches a query to a pad. The query should have been allocated by the
3036 * caller via one of the type-specific allocation functions in gstquery.h. The
3037 * element is responsible for filling the query with an appropriate response,
3038 * which should then be parsed with a type-specific query parsing function.
3040 * Again, the caller is responsible for both the allocation and deallocation of
3041 * the query structure.
3043 * Returns: TRUE if the query could be performed.
3046 gst_pad_query (GstPad * pad, GstQuery * query)
3048 GstPadQueryFunction func;
3050 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
3051 g_return_val_if_fail (GST_IS_QUERY (query), FALSE);
3053 GST_DEBUG_OBJECT (pad, "sending query %p", query);
3055 if ((func = GST_PAD_QUERYFUNC (pad)) == NULL)
3058 return func (pad, query);
3062 GST_DEBUG_OBJECT (pad, "had no query function");
3068 * gst_pad_peer_query:
3069 * @pad: a #GstPad to invoke the peer query on.
3070 * @query: the #GstQuery to perform.
3072 * Performs gst_pad_query() on the peer of @pad.
3074 * The caller is responsible for both the allocation and deallocation of
3075 * the query structure.
3077 * Returns: TRUE if the query could be performed. This function returns %FALSE
3078 * if @pad has no peer.
3083 gst_pad_peer_query (GstPad * pad, GstQuery * query)
3088 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
3089 g_return_val_if_fail (GST_IS_QUERY (query), FALSE);
3091 GST_OBJECT_LOCK (pad);
3093 GST_DEBUG_OBJECT (pad, "peer query");
3095 peerpad = GST_PAD_PEER (pad);
3096 if (G_UNLIKELY (peerpad == NULL))
3099 gst_object_ref (peerpad);
3100 GST_OBJECT_UNLOCK (pad);
3102 result = gst_pad_query (peerpad, query);
3104 gst_object_unref (peerpad);
3111 GST_WARNING_OBJECT (pad, "pad has no peer");
3112 GST_OBJECT_UNLOCK (pad);
3118 * gst_pad_query_default:
3119 * @pad: a #GstPad to call the default query handler on.
3120 * @query: the #GstQuery to handle.
3122 * Invokes the default query handler for the given pad.
3123 * The query is sent to all pads internally linked to @pad. Note that
3124 * if there are many possible sink pads that are internally linked to
3125 * @pad, only one will be sent the query.
3126 * Multi-sinkpad elements should implement custom query handlers.
3128 * Returns: TRUE if the query was performed succesfully.
3131 gst_pad_query_default (GstPad * pad, GstQuery * query)
3133 switch (GST_QUERY_TYPE (query)) {
3134 case GST_QUERY_POSITION:
3135 case GST_QUERY_SEEKING:
3136 case GST_QUERY_FORMATS:
3137 case GST_QUERY_LATENCY:
3138 case GST_QUERY_JITTER:
3139 case GST_QUERY_RATE:
3140 case GST_QUERY_CONVERT:
3142 return gst_pad_dispatcher
3143 (pad, (GstPadDispatcherFunction) gst_pad_query, query);
3147 #ifndef GST_DISABLE_LOADSAVE
3148 /* FIXME: why isn't this on a GstElement ? */
3150 * gst_pad_load_and_link:
3151 * @self: an #xmlNodePtr to read the description from.
3152 * @parent: the #GstObject element that owns the pad.
3154 * Reads the pad definition from the XML node and links the given pad
3155 * in the element to a pad of an element up in the hierarchy.
3158 gst_pad_load_and_link (xmlNodePtr self, GstObject * parent)
3160 xmlNodePtr field = self->xmlChildrenNode;
3161 GstPad *pad = NULL, *targetpad;
3165 GstObject *grandparent;
3169 if (!strcmp ((char *) field->name, "name")) {
3170 name = (gchar *) xmlNodeGetContent (field);
3171 pad = gst_element_get_pad (GST_ELEMENT (parent), name);
3173 } else if (!strcmp ((char *) field->name, "peer")) {
3174 peer = (gchar *) xmlNodeGetContent (field);
3176 field = field->next;
3178 g_return_if_fail (pad != NULL);
3183 split = g_strsplit (peer, ".", 2);
3185 if (split[0] == NULL || split[1] == NULL) {
3186 GST_CAT_DEBUG_OBJECT (GST_CAT_XML, pad,
3187 "Could not parse peer '%s', leaving unlinked", peer);
3194 g_return_if_fail (split[0] != NULL);
3195 g_return_if_fail (split[1] != NULL);
3197 grandparent = gst_object_get_parent (parent);
3199 if (grandparent && GST_IS_BIN (grandparent)) {
3200 target = gst_bin_get_by_name_recurse_up (GST_BIN (grandparent), split[0]);
3207 targetpad = gst_element_get_pad (target, split[1]);
3209 if (targetpad == NULL)
3212 gst_pad_link (pad, targetpad);
3219 * gst_pad_save_thyself:
3220 * @pad: a #GstPad to save.
3221 * @parent: the parent #xmlNodePtr to save the description in.
3223 * Saves the pad into an xml representation.
3225 * Returns: the #xmlNodePtr representation of the pad.
3228 gst_pad_save_thyself (GstObject * object, xmlNodePtr parent)
3233 g_return_val_if_fail (GST_IS_PAD (object), NULL);
3235 pad = GST_PAD (object);
3237 xmlNewChild (parent, NULL, (xmlChar *) "name",
3238 (xmlChar *) GST_PAD_NAME (pad));
3240 if (GST_PAD_IS_SRC (pad)) {
3241 xmlNewChild (parent, NULL, (xmlChar *) "direction", (xmlChar *) "source");
3242 } else if (GST_PAD_IS_SINK (pad)) {
3243 xmlNewChild (parent, NULL, (xmlChar *) "direction", (xmlChar *) "sink");
3245 xmlNewChild (parent, NULL, (xmlChar *) "direction", (xmlChar *) "unknown");
3248 if (GST_PAD_PEER (pad) != NULL) {
3251 peer = GST_PAD_PEER (pad);
3252 /* first check to see if the peer's parent's parent is the same */
3253 /* we just save it off */
3254 content = g_strdup_printf ("%s.%s",
3255 GST_OBJECT_NAME (GST_PAD_PARENT (peer)), GST_PAD_NAME (peer));
3256 xmlNewChild (parent, NULL, (xmlChar *) "peer", (xmlChar *) content);
3259 xmlNewChild (parent, NULL, (xmlChar *) "peer", NULL);
3266 * gst_ghost_pad_save_thyself:
3267 * @pad: a ghost #GstPad to save.
3268 * @parent: the parent #xmlNodePtr to save the description in.
3270 * Saves the ghost pad into an xml representation.
3272 * Returns: the #xmlNodePtr representation of the pad.
3275 gst_ghost_pad_save_thyself (GstPad * pad, xmlNodePtr parent)
3279 g_return_val_if_fail (GST_IS_GHOST_PAD (pad), NULL);
3281 self = xmlNewChild (parent, NULL, (xmlChar *) "ghostpad", NULL);
3282 xmlNewChild (self, NULL, (xmlChar *) "name", (xmlChar *) GST_PAD_NAME (pad));
3283 xmlNewChild (self, NULL, (xmlChar *) "parent",
3284 (xmlChar *) GST_OBJECT_NAME (GST_PAD_PARENT (pad)));
3286 /* FIXME FIXME FIXME! */
3291 #endif /* GST_DISABLE_LOADSAVE */
3294 * should be called with pad OBJECT_LOCK and STREAM_LOCK held.
3295 * GST_PAD_IS_BLOCKED (pad) == TRUE when this function is
3298 * This function performs the pad blocking when an event, buffer push
3299 * or buffer_alloc is performed on a _SRC_ pad. It blocks the
3300 * streaming thread after informing the pad has been blocked.
3302 * An application can with this method wait and block any streaming
3303 * thread and perform operations such as seeking or linking.
3305 * Two methods are available for notifying the application of the
3307 * - the callback method, which happens in the STREAMING thread with
3308 * the STREAM_LOCK held. With this method, the most useful way of
3309 * dealing with the callback is to post a message to the main thread
3310 * where the pad block can then be handled outside of the streaming
3311 * thread. With the last method one can perform all operations such
3312 * as doing a state change, linking, unblocking, seeking etc on the
3314 * - the GCond signal method, which makes any thread unblock when
3315 * the pad block happens.
3317 * During the actual blocking state, the GST_PAD_BLOCKING flag is set.
3318 * The GST_PAD_BLOCKING flag is unset when the pad was unblocked.
3322 static GstFlowReturn
3323 handle_pad_block (GstPad * pad)
3325 GstPadBlockCallback callback;
3327 GstFlowReturn ret = GST_FLOW_OK;
3329 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "signal block taken");
3331 /* flushing, don't bother trying to block and return WRONG_STATE
3333 if (GST_PAD_IS_FLUSHING (pad))
3334 goto flushingnonref;
3336 /* we grab an extra ref for the callbacks, this is probably not
3337 * needed (callback code does not have a ref and cannot unref). I
3338 * think this was done to make it possible to unref the element in
3339 * the callback, which is in the end totally impossible as it
3340 * requires grabbing the STREAM_LOCK and OBJECT_LOCK which are
3341 * all taken when calling this function. */
3342 gst_object_ref (pad);
3344 /* we either have a callback installed to notify the block or
3345 * some other thread is doing a GCond wait. */
3346 callback = pad->block_callback;
3348 /* there is a callback installed, call it. We release the
3349 * lock so that the callback can do something usefull with the
3351 user_data = pad->block_data;
3352 GST_OBJECT_UNLOCK (pad);
3353 callback (pad, TRUE, user_data);
3354 GST_OBJECT_LOCK (pad);
3356 /* we released the lock, recheck flushing */
3357 if (GST_PAD_IS_FLUSHING (pad))
3360 /* no callback, signal the thread that is doing a GCond wait
3362 GST_PAD_BLOCK_BROADCAST (pad);
3365 /* OBJECT_LOCK could have been released when we did the callback, which
3366 * then could have made the pad unblock so we need to check the blocking
3367 * condition again. */
3368 while (GST_PAD_IS_BLOCKED (pad)) {
3369 /* now we block the streaming thread. It can be unlocked when we
3370 * deactivate the pad (which will also set the FLUSHING flag) or
3371 * when the pad is unblocked. A flushing event will also unblock
3372 * the pad after setting the FLUSHING flag. */
3373 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3374 "Waiting to be unblocked or set flushing");
3375 GST_OBJECT_FLAG_SET (pad, GST_PAD_BLOCKING);
3376 GST_PAD_BLOCK_WAIT (pad);
3377 GST_OBJECT_FLAG_UNSET (pad, GST_PAD_BLOCKING);
3379 /* see if we got unblocked by a flush or not */
3380 if (GST_PAD_IS_FLUSHING (pad))
3384 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "got unblocked");
3386 /* when we get here, the pad is unblocked again and we perform
3387 * the needed unblock code. */
3388 callback = pad->block_callback;
3390 /* we need to call the callback */
3391 user_data = pad->block_data;
3392 GST_OBJECT_UNLOCK (pad);
3393 callback (pad, FALSE, user_data);
3394 GST_OBJECT_LOCK (pad);
3396 /* we need to signal the thread waiting on the GCond */
3397 GST_PAD_BLOCK_BROADCAST (pad);
3400 gst_object_unref (pad);
3406 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "pad was flushing");
3407 return GST_FLOW_WRONG_STATE;
3411 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "pad became flushing");
3412 gst_object_unref (pad);
3413 return GST_FLOW_WRONG_STATE;
3417 /**********************************************************************
3418 * Data passing functions
3422 gst_pad_emit_have_data_signal (GstPad * pad, GstMiniObject * obj)
3425 GValue args[2] = { {0}, {0} };
3430 g_value_init (&ret, G_TYPE_BOOLEAN);
3431 g_value_set_boolean (&ret, TRUE);
3432 g_value_init (&args[0], GST_TYPE_PAD);
3433 g_value_set_object (&args[0], pad);
3434 g_value_init (&args[1], GST_TYPE_MINI_OBJECT);
3435 gst_value_set_mini_object (&args[1], obj);
3437 if (GST_IS_EVENT (obj))
3438 detail = event_quark;
3440 detail = buffer_quark;
3443 g_signal_emitv (args, gst_pad_signals[PAD_HAVE_DATA], detail, &ret);
3444 res = g_value_get_boolean (&ret);
3447 g_value_unset (&ret);
3448 g_value_unset (&args[0]);
3449 g_value_unset (&args[1]);
3454 /* this is the chain function that does not perform the additional argument
3455 * checking for that little extra speed.
3457 static inline GstFlowReturn
3458 gst_pad_chain_unchecked (GstPad * pad, GstBuffer * buffer)
3461 gboolean caps_changed;
3462 GstPadChainFunction chainfunc;
3464 gboolean emit_signal;
3466 GST_PAD_STREAM_LOCK (pad);
3468 GST_OBJECT_LOCK (pad);
3469 if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad)))
3472 caps = GST_BUFFER_CAPS (buffer);
3473 caps_changed = caps && caps != GST_PAD_CAPS (pad);
3475 emit_signal = GST_PAD_DO_BUFFER_SIGNALS (pad) > 0;
3476 GST_OBJECT_UNLOCK (pad);
3478 /* see if the signal should be emited, we emit before caps nego as
3479 * we might drop the buffer and do capsnego for nothing. */
3480 if (G_UNLIKELY (emit_signal)) {
3481 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (buffer)))
3485 /* we got a new datatype on the pad, see if it can handle it */
3486 if (G_UNLIKELY (caps_changed)) {
3487 GST_DEBUG_OBJECT (pad, "caps changed to %p %" GST_PTR_FORMAT, caps, caps);
3488 if (G_UNLIKELY (!gst_pad_configure_sink (pad, caps)))
3489 goto not_negotiated;
3492 /* NOTE: we read the chainfunc unlocked.
3493 * we cannot hold the lock for the pad so we might send
3494 * the data to the wrong function. This is not really a
3495 * problem since functions are assigned at creation time
3496 * and don't change that often... */
3497 if (G_UNLIKELY ((chainfunc = GST_PAD_CHAINFUNC (pad)) == NULL))
3500 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3501 "calling chainfunction &%s", GST_DEBUG_FUNCPTR_NAME (chainfunc));
3503 ret = chainfunc (pad, buffer);
3505 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3506 "called chainfunction &%s, returned %s",
3507 GST_DEBUG_FUNCPTR_NAME (chainfunc), gst_flow_get_name (ret));
3509 GST_PAD_STREAM_UNLOCK (pad);
3516 gst_buffer_unref (buffer);
3517 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3518 "pushing, but pad was flushing");
3519 GST_OBJECT_UNLOCK (pad);
3520 GST_PAD_STREAM_UNLOCK (pad);
3521 return GST_FLOW_WRONG_STATE;
3525 gst_buffer_unref (buffer);
3526 GST_DEBUG_OBJECT (pad, "Dropping buffer due to FALSE probe return");
3527 GST_PAD_STREAM_UNLOCK (pad);
3532 gst_buffer_unref (buffer);
3533 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3534 "pushing buffer but pad did not accept");
3535 GST_PAD_STREAM_UNLOCK (pad);
3536 return GST_FLOW_NOT_NEGOTIATED;
3540 gst_buffer_unref (buffer);
3541 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3542 "pushing, but not chainhandler");
3543 GST_ELEMENT_ERROR (GST_PAD_PARENT (pad), CORE, PAD, (NULL),
3544 ("push on pad %s:%s but it has no chainfunction",
3545 GST_DEBUG_PAD_NAME (pad)));
3546 GST_PAD_STREAM_UNLOCK (pad);
3547 return GST_FLOW_NOT_SUPPORTED;
3553 * @pad: a sink #GstPad, returns GST_FLOW_ERROR if not.
3554 * @buffer: the #GstBuffer to send, return GST_FLOW_ERROR if not.
3556 * Chain a buffer to @pad.
3558 * The function returns #GST_FLOW_WRONG_STATE if the pad was flushing.
3560 * If the caps on @buffer are different from the current caps on @pad, this
3561 * function will call any setcaps function (see gst_pad_set_setcaps_function())
3562 * installed on @pad. If the new caps are not acceptable for @pad, this
3563 * function returns #GST_FLOW_NOT_NEGOTIATED.
3565 * The function proceeds calling the chain function installed on @pad (see
3566 * gst_pad_set_chain_function()) and the return value of that function is
3567 * returned to the caller. #GST_FLOW_NOT_SUPPORTED is returned if @pad has no
3570 * In all cases, success or failure, the caller loses its reference to @buffer
3571 * after calling this function.
3573 * Returns: a #GstFlowReturn from the pad.
3578 gst_pad_chain (GstPad * pad, GstBuffer * buffer)
3580 g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
3581 g_return_val_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SINK,
3583 g_return_val_if_fail (GST_IS_BUFFER (buffer), GST_FLOW_ERROR);
3585 return gst_pad_chain_unchecked (pad, buffer);
3590 * @pad: a source #GstPad, returns #GST_FLOW_ERROR if not.
3591 * @buffer: the #GstBuffer to push returns GST_FLOW_ERROR if not.
3593 * Pushes a buffer to the peer of @pad.
3595 * This function will call an installed pad block before triggering any
3596 * installed pad probes.
3598 * If the caps on @buffer are different from the currently configured caps on
3599 * @pad, this function will call any installed setcaps function on @pad (see
3600 * gst_pad_set_setcaps_function()). In case of failure to renegotiate the new
3601 * format, this function returns #GST_FLOW_NOT_NEGOTIATED.
3603 * The function proceeds calling gst_pad_chain() on the peer pad and returns
3604 * the value from that function. If @pad has no peer, #GST_FLOW_NOT_LINKED will
3607 * In all cases, success or failure, the caller loses its reference to @buffer
3608 * after calling this function.
3610 * Returns: a #GstFlowReturn from the peer pad.
3615 gst_pad_push (GstPad * pad, GstBuffer * buffer)
3621 gboolean caps_changed;
3623 g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
3624 g_return_val_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SRC, GST_FLOW_ERROR);
3625 g_return_val_if_fail (GST_IS_BUFFER (buffer), GST_FLOW_ERROR);
3627 GST_OBJECT_LOCK (pad);
3629 /* FIXME: this check can go away; pad_set_blocked could be implemented with
3630 * probes completely or probes with an extended pad block. */
3631 while (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad)))
3632 if ((ret = handle_pad_block (pad)) != GST_FLOW_OK)
3635 /* we emit signals on the pad arg, the peer will have a chance to
3636 * emit in the _chain() function */
3637 if (G_UNLIKELY (GST_PAD_DO_BUFFER_SIGNALS (pad) > 0)) {
3638 /* unlock before emitting */
3639 GST_OBJECT_UNLOCK (pad);
3641 /* if the signal handler returned FALSE, it means we should just drop the
3643 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (buffer)))
3646 GST_OBJECT_LOCK (pad);
3649 if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
3652 /* take ref to peer pad before releasing the lock */
3653 gst_object_ref (peer);
3655 /* Before pushing the buffer to the peer pad, ensure that caps
3656 * are set on this pad */
3657 caps = GST_BUFFER_CAPS (buffer);
3658 caps_changed = caps && caps != GST_PAD_CAPS (pad);
3660 GST_OBJECT_UNLOCK (pad);
3662 /* we got a new datatype from the pad, it had better handle it */
3663 if (G_UNLIKELY (caps_changed)) {
3664 GST_DEBUG_OBJECT (pad,
3665 "caps changed from %" GST_PTR_FORMAT " to %p %" GST_PTR_FORMAT,
3666 GST_PAD_CAPS (pad), caps, caps);
3667 if (G_UNLIKELY (!gst_pad_configure_src (pad, caps, TRUE)))
3668 goto not_negotiated;
3671 ret = gst_pad_chain_unchecked (peer, buffer);
3673 gst_object_unref (peer);
3677 /* ERROR recovery here */
3680 gst_buffer_unref (buffer);
3681 GST_DEBUG_OBJECT (pad, "pad block stopped by flush");
3682 GST_OBJECT_UNLOCK (pad);
3687 gst_buffer_unref (buffer);
3688 GST_DEBUG_OBJECT (pad, "Dropping buffer due to FALSE probe return");
3693 gst_buffer_unref (buffer);
3694 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3695 "pushing, but it was not linked");
3696 GST_OBJECT_UNLOCK (pad);
3697 return GST_FLOW_NOT_LINKED;
3701 gst_buffer_unref (buffer);
3702 gst_object_unref (peer);
3703 GST_CAT_DEBUG_OBJECT (GST_CAT_SCHEDULING, pad,
3704 "element pushed buffer then refused to accept the caps");
3705 return GST_FLOW_NOT_NEGOTIATED;
3710 * gst_pad_check_pull_range:
3711 * @pad: a sink #GstPad.
3713 * Checks if a gst_pad_pull_range() can be performed on the peer
3714 * source pad. This function is used by plugins that want to check
3715 * if they can use random access on the peer source pad.
3717 * The peer sourcepad can implement a custom #GstPadCheckGetRangeFunction
3718 * if it needs to perform some logic to determine if pull_range is
3721 * Returns: a gboolean with the result.
3726 gst_pad_check_pull_range (GstPad * pad)
3730 GstPadCheckGetRangeFunction checkgetrangefunc;
3732 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
3734 GST_OBJECT_LOCK (pad);
3735 if (GST_PAD_DIRECTION (pad) != GST_PAD_SINK)
3736 goto wrong_direction;
3738 if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
3741 gst_object_ref (peer);
3742 GST_OBJECT_UNLOCK (pad);
3744 /* see note in above function */
3745 if (G_LIKELY ((checkgetrangefunc = peer->checkgetrangefunc) == NULL)) {
3746 /* FIXME, kindoff ghetto */
3747 ret = GST_PAD_GETRANGEFUNC (peer) != NULL;
3748 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3749 "no checkgetrangefunc, assuming %d", ret);
3751 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3752 "calling checkgetrangefunc %s of peer pad %s:%s",
3753 GST_DEBUG_FUNCPTR_NAME (checkgetrangefunc), GST_DEBUG_PAD_NAME (peer));
3755 ret = checkgetrangefunc (peer);
3758 gst_object_unref (peer);
3762 /* ERROR recovery here */
3765 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3766 "checking pull range, but pad must be a sinkpad");
3767 GST_OBJECT_UNLOCK (pad);
3772 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3773 "checking pull range, but it was not linked");
3774 GST_OBJECT_UNLOCK (pad);
3780 * gst_pad_get_range:
3781 * @pad: a src #GstPad, returns #GST_FLOW_ERROR if not.
3782 * @offset: The start offset of the buffer
3783 * @size: The length of the buffer
3784 * @buffer: a pointer to hold the #GstBuffer, returns #GST_FLOW_ERROR if %NULL.
3786 * When @pad is flushing this function returns #GST_FLOW_WRONG_STATE
3789 * Calls the getrange function of @pad, see #GstPadGetRangeFunction for a
3790 * description of a getrange function. If @pad has no getrange function
3791 * installed (see gst_pad_set_getrange_function()) this function returns
3792 * #GST_FLOW_NOT_SUPPORTED.
3794 * @buffer's caps must either be unset or the same as what is already
3795 * configured on @pad. Renegotiation within a running pull-mode pipeline is not
3798 * This is a lowlevel function. Usualy gst_pad_pull_range() is used.
3800 * Returns: a #GstFlowReturn from the pad.
3805 gst_pad_get_range (GstPad * pad, guint64 offset, guint size,
3806 GstBuffer ** buffer)
3809 GstPadGetRangeFunction getrangefunc;
3810 gboolean emit_signal;
3812 g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
3813 g_return_val_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SRC, GST_FLOW_ERROR);
3814 g_return_val_if_fail (buffer != NULL, GST_FLOW_ERROR);
3816 GST_PAD_STREAM_LOCK (pad);
3818 GST_OBJECT_LOCK (pad);
3819 if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad)))
3822 emit_signal = GST_PAD_DO_BUFFER_SIGNALS (pad) > 0;
3823 GST_OBJECT_UNLOCK (pad);
3825 if (G_UNLIKELY ((getrangefunc = GST_PAD_GETRANGEFUNC (pad)) == NULL))
3828 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3829 "calling getrangefunc %s, offset %"
3830 G_GUINT64_FORMAT ", size %u",
3831 GST_DEBUG_FUNCPTR_NAME (getrangefunc), offset, size);
3833 ret = getrangefunc (pad, offset, size, buffer);
3835 /* can only fire the signal if we have a valid buffer */
3836 if (G_UNLIKELY (emit_signal) && (ret == GST_FLOW_OK)) {
3837 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (*buffer)))
3841 GST_PAD_STREAM_UNLOCK (pad);
3843 if (G_LIKELY (ret == GST_FLOW_OK)) {
3845 gboolean caps_changed;
3847 GST_OBJECT_LOCK (pad);
3848 /* Before pushing the buffer to the peer pad, ensure that caps
3849 * are set on this pad */
3850 caps = GST_BUFFER_CAPS (*buffer);
3851 caps_changed = caps && caps != GST_PAD_CAPS (pad);
3852 GST_OBJECT_UNLOCK (pad);
3854 /* we got a new datatype from the pad not supported in a running pull-mode
3856 if (G_UNLIKELY (caps_changed))
3857 goto not_negotiated;
3865 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3866 "pulling range, but pad was flushing");
3867 GST_OBJECT_UNLOCK (pad);
3868 GST_PAD_STREAM_UNLOCK (pad);
3869 return GST_FLOW_WRONG_STATE;
3873 GST_ELEMENT_ERROR (GST_PAD_PARENT (pad), CORE, PAD, (NULL),
3874 ("pullrange on pad %s:%s but it has no getrangefunction",
3875 GST_DEBUG_PAD_NAME (pad)));
3876 GST_PAD_STREAM_UNLOCK (pad);
3877 return GST_FLOW_NOT_SUPPORTED;
3881 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3882 "Dropping data after FALSE probe return");
3883 GST_PAD_STREAM_UNLOCK (pad);
3884 gst_buffer_unref (*buffer);
3886 return GST_FLOW_UNEXPECTED;
3890 /* ideally we want to use the commented-out code, but currently demuxers
3891 * and typefind do not follow part-negotiation.txt. When switching into
3892 * pull mode, typefind should probably return the found caps from
3893 * getcaps(), and demuxers should do the setcaps(). */
3896 gst_buffer_unref (*buffer);
3898 GST_CAT_WARNING_OBJECT (GST_CAT_SCHEDULING, pad,
3899 "getrange returned buffer of different caps");
3900 return GST_FLOW_NOT_NEGOTIATED;
3902 GST_CAT_DEBUG_OBJECT (GST_CAT_SCHEDULING, pad,
3903 "getrange returned buffer of different caps");
3910 * gst_pad_pull_range:
3911 * @pad: a sink #GstPad, returns GST_FLOW_ERROR if not.
3912 * @offset: The start offset of the buffer
3913 * @size: The length of the buffer
3914 * @buffer: a pointer to hold the #GstBuffer, returns GST_FLOW_ERROR if %NULL.
3916 * Pulls a @buffer from the peer pad.
3918 * This function will first trigger the pad block signal if it was
3921 * When @pad is not linked #GST_FLOW_NOT_LINKED is returned else this
3922 * function returns the result of gst_pad_get_range() on the peer pad.
3923 * See gst_pad_get_range() for a list of return values and for the
3924 * semantics of the arguments of this function.
3926 * @buffer's caps must either be unset or the same as what is already
3927 * configured on @pad. Renegotiation within a running pull-mode pipeline is not
3930 * Returns: a #GstFlowReturn from the peer pad.
3931 * When this function returns #GST_FLOW_OK, @buffer will contain a valid
3932 * #GstBuffer that should be freed with gst_buffer_unref() after usage.
3933 * @buffer may not be used or freed when any other return value than
3934 * #GST_FLOW_OK is returned.
3939 gst_pad_pull_range (GstPad * pad, guint64 offset, guint size,
3940 GstBuffer ** buffer)
3944 gboolean emit_signal;
3946 g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
3947 g_return_val_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SINK,
3949 g_return_val_if_fail (buffer != NULL, GST_FLOW_ERROR);
3951 GST_OBJECT_LOCK (pad);
3953 while (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad)))
3954 handle_pad_block (pad);
3956 if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
3959 /* signal emision for the pad, peer has chance to emit when
3960 * we call _get_range() */
3961 emit_signal = GST_PAD_DO_BUFFER_SIGNALS (pad) > 0;
3963 gst_object_ref (peer);
3964 GST_OBJECT_UNLOCK (pad);
3966 ret = gst_pad_get_range (peer, offset, size, buffer);
3968 gst_object_unref (peer);
3970 /* can only fire the signal if we have a valid buffer */
3971 if (G_UNLIKELY (emit_signal) && (ret == GST_FLOW_OK)) {
3972 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (*buffer)))
3976 if (G_LIKELY (ret == GST_FLOW_OK)) {
3978 gboolean caps_changed;
3980 GST_OBJECT_LOCK (pad);
3981 /* Before pushing the buffer to the peer pad, ensure that caps
3982 * are set on this pad */
3983 caps = GST_BUFFER_CAPS (*buffer);
3984 caps_changed = caps && caps != GST_PAD_CAPS (pad);
3985 GST_OBJECT_UNLOCK (pad);
3987 /* we got a new datatype on the pad, see if it can handle it */
3988 if (G_UNLIKELY (caps_changed))
3989 goto not_negotiated;
3994 /* ERROR recovery here */
3997 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3998 "pulling range, but it was not linked");
3999 GST_OBJECT_UNLOCK (pad);
4000 return GST_FLOW_NOT_LINKED;
4004 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
4005 "Dropping data after FALSE probe return");
4006 gst_buffer_unref (*buffer);
4008 return GST_FLOW_UNEXPECTED;
4012 /* ideally we want to use the commented-out code, but currently demuxers
4013 * and typefind do not follow part-negotiation.txt. When switching into
4014 * pull mode, typefind should probably return the found caps from
4015 * getcaps(), and demuxers should do the setcaps(). */
4018 gst_buffer_unref (*buffer);
4020 GST_CAT_WARNING_OBJECT (GST_CAT_SCHEDULING, pad,
4021 "pullrange returned buffer of different caps");
4022 return GST_FLOW_NOT_NEGOTIATED;
4024 GST_CAT_DEBUG_OBJECT (GST_CAT_SCHEDULING, pad,
4025 "pullrange returned buffer of different caps");
4031 * gst_pad_push_event:
4032 * @pad: a #GstPad to push the event to.
4033 * @event: the #GstEvent to send to the pad.
4035 * Sends the event to the peer of the given pad. This function is
4036 * mainly used by elements to send events to their peer
4039 * This function takes owership of the provided event so you should
4040 * gst_event_ref() it if you want to reuse the event after this call.
4042 * Returns: TRUE if the event was handled.
4047 gst_pad_push_event (GstPad * pad, GstEvent * event)
4052 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
4053 g_return_val_if_fail (event != NULL, FALSE);
4054 g_return_val_if_fail (GST_IS_EVENT (event), FALSE);
4056 GST_LOG_OBJECT (pad, "event: %s", GST_EVENT_TYPE_NAME (event));
4058 GST_OBJECT_LOCK (pad);
4060 /* Two checks to be made:
4061 * . (un)set the FLUSHING flag for flushing events,
4062 * . handle pad blocking */
4063 switch (GST_EVENT_TYPE (event)) {
4064 case GST_EVENT_FLUSH_START:
4065 GST_PAD_SET_FLUSHING (pad);
4067 if (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad))) {
4068 /* flush start will have set the FLUSHING flag and will then
4069 * unlock all threads doing a GCond wait on the blocking pad. This
4070 * will typically unblock the STREAMING thread blocked on a pad. */
4071 GST_LOG_OBJECT (pad, "Pad is blocked, not forwarding flush-start, "
4072 "doing block signal.");
4073 GST_PAD_BLOCK_BROADCAST (pad);
4077 case GST_EVENT_FLUSH_STOP:
4078 GST_PAD_UNSET_FLUSHING (pad);
4080 /* if we are blocked, flush away the FLUSH_STOP event */
4081 if (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad))) {
4082 GST_LOG_OBJECT (pad, "Pad is blocked, not forwarding flush-stop");
4087 while (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad))) {
4088 /* block the event as long as the pad is blocked */
4089 if (handle_pad_block (pad) != GST_FLOW_OK)
4095 if (G_UNLIKELY (GST_PAD_DO_EVENT_SIGNALS (pad) > 0)) {
4096 GST_OBJECT_UNLOCK (pad);
4098 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (event)))
4101 GST_OBJECT_LOCK (pad);
4103 peerpad = GST_PAD_PEER (pad);
4104 if (peerpad == NULL)
4107 GST_LOG_OBJECT (pad, "sending event %s to peerpad %" GST_PTR_FORMAT,
4108 GST_EVENT_TYPE_NAME (event), peerpad);
4109 gst_object_ref (peerpad);
4110 GST_OBJECT_UNLOCK (pad);
4112 result = gst_pad_send_event (peerpad, event);
4114 /* Note: we gave away ownership of the event at this point */
4115 GST_LOG_OBJECT (pad, "sent event to peerpad %" GST_PTR_FORMAT ", result %d",
4117 gst_object_unref (peerpad);
4121 /* ERROR handling */
4124 GST_DEBUG_OBJECT (pad, "Dropping event after FALSE probe return");
4125 gst_event_unref (event);
4130 GST_DEBUG_OBJECT (pad, "Dropping event because pad is not linked");
4131 gst_event_unref (event);
4132 GST_OBJECT_UNLOCK (pad);
4137 GST_DEBUG_OBJECT (pad,
4138 "Not forwarding event since we're flushing and blocking");
4139 gst_event_unref (event);
4140 GST_OBJECT_UNLOCK (pad);
4146 * gst_pad_send_event:
4147 * @pad: a #GstPad to send the event to.
4148 * @event: the #GstEvent to send to the pad.
4150 * Sends the event to the pad. This function can be used
4151 * by applications to send events in the pipeline.
4153 * If @pad is a source pad, @event should be an upstream event. If @pad is a
4154 * sink pad, @event should be a downstream event. For example, you would not
4155 * send a #GST_EVENT_EOS on a src pad; EOS events only propagate downstream.
4156 * Furthermore, some downstream events have to be serialized with data flow,
4157 * like EOS, while some can travel out-of-band, like #GST_EVENT_FLUSH_START. If
4158 * the event needs to be serialized with data flow, this function will take the
4159 * pad's stream lock while calling its event function.
4161 * To find out whether an event type is upstream, downstream, or downstream and
4162 * serialized, see #GstEventTypeFlags, gst_event_type_get_flags(),
4163 * #GST_EVENT_IS_UPSTREAM, #GST_EVENT_IS_DOWNSTREAM, and
4164 * #GST_EVENT_IS_SERIALIZED. Note that in practice that an application or
4165 * plugin doesn't need to bother itself with this information; the core handles
4166 * all necessary locks and checks.
4168 * This function takes owership of the provided event so you should
4169 * gst_event_ref() it if you want to reuse the event after this call.
4171 * Returns: TRUE if the event was handled.
4174 gst_pad_send_event (GstPad * pad, GstEvent * event)
4176 gboolean result = FALSE;
4177 GstPadEventFunction eventfunc;
4178 gboolean serialized, need_unlock = FALSE;
4180 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
4181 g_return_val_if_fail (event != NULL, FALSE);
4183 GST_OBJECT_LOCK (pad);
4184 if (GST_PAD_IS_SINK (pad)) {
4185 if (G_UNLIKELY (!GST_EVENT_IS_DOWNSTREAM (event)))
4186 goto wrong_direction;
4187 serialized = GST_EVENT_IS_SERIALIZED (event);
4188 } else if (GST_PAD_IS_SRC (pad)) {
4189 if (G_UNLIKELY (!GST_EVENT_IS_UPSTREAM (event)))
4190 goto wrong_direction;
4191 /* events on srcpad never are serialized */
4194 goto unknown_direction;
4196 if (G_UNLIKELY (GST_EVENT_SRC (event) == NULL)) {
4197 GST_LOG_OBJECT (pad, "event had no source, setting pad as event source");
4198 GST_EVENT_SRC (event) = gst_object_ref (pad);
4202 if (G_UNLIKELY (GST_PAD_DO_EVENT_SIGNALS (pad) > 0)) {
4203 GST_OBJECT_UNLOCK (pad);
4205 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT_CAST (event)))
4208 GST_OBJECT_LOCK (pad);
4211 switch (GST_EVENT_TYPE (event)) {
4212 case GST_EVENT_FLUSH_START:
4213 GST_CAT_DEBUG_OBJECT (GST_CAT_EVENT, pad,
4214 "have event type %d (FLUSH_START)", GST_EVENT_TYPE (event));
4216 /* can't even accept a flush begin event when flushing */
4217 if (GST_PAD_IS_FLUSHING (pad))
4219 GST_PAD_SET_FLUSHING (pad);
4220 GST_CAT_DEBUG_OBJECT (GST_CAT_EVENT, pad, "set flush flag");
4222 case GST_EVENT_FLUSH_STOP:
4223 GST_PAD_UNSET_FLUSHING (pad);
4224 GST_CAT_DEBUG_OBJECT (GST_CAT_EVENT, pad, "cleared flush flag");
4225 GST_OBJECT_UNLOCK (pad);
4226 /* grab stream lock */
4227 GST_PAD_STREAM_LOCK (pad);
4229 GST_OBJECT_LOCK (pad);
4232 GST_CAT_DEBUG_OBJECT (GST_CAT_EVENT, pad, "have event type %s",
4233 GST_EVENT_TYPE_NAME (event));
4235 /* make this a little faster, no point in grabbing the lock
4236 * if the pad is allready flushing. */
4237 if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad)))
4241 /* lock order: STREAM_LOCK, LOCK, recheck flushing. */
4242 GST_OBJECT_UNLOCK (pad);
4243 GST_PAD_STREAM_LOCK (pad);
4245 GST_OBJECT_LOCK (pad);
4246 if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad)))
4251 if (G_UNLIKELY ((eventfunc = GST_PAD_EVENTFUNC (pad)) == NULL))
4254 GST_OBJECT_UNLOCK (pad);
4256 result = eventfunc (pad, event);
4259 GST_PAD_STREAM_UNLOCK (pad);
4261 GST_DEBUG_OBJECT (pad, "sent event, result %d", result);
4265 /* ERROR handling */
4268 g_warning ("pad %s:%s sending %s event in wrong direction",
4269 GST_DEBUG_PAD_NAME (pad), GST_EVENT_TYPE_NAME (event));
4270 GST_OBJECT_UNLOCK (pad);
4271 gst_event_unref (event);
4276 g_warning ("pad %s:%s has invalid direction", GST_DEBUG_PAD_NAME (pad));
4277 GST_OBJECT_UNLOCK (pad);
4278 gst_event_unref (event);
4283 g_warning ("pad %s:%s has no event handler, file a bug.",
4284 GST_DEBUG_PAD_NAME (pad));
4285 GST_OBJECT_UNLOCK (pad);
4287 GST_PAD_STREAM_UNLOCK (pad);
4288 gst_event_unref (event);
4293 GST_OBJECT_UNLOCK (pad);
4295 GST_PAD_STREAM_UNLOCK (pad);
4296 GST_CAT_INFO_OBJECT (GST_CAT_EVENT, pad,
4297 "Received event on flushing pad. Discarding");
4298 gst_event_unref (event);
4303 GST_DEBUG_OBJECT (pad, "Dropping event after FALSE probe return");
4304 gst_event_unref (event);
4310 * gst_pad_set_element_private:
4311 * @pad: the #GstPad to set the private data of.
4312 * @priv: The private data to attach to the pad.
4314 * Set the given private data gpointer on the pad.
4315 * This function can only be used by the element that owns the pad.
4316 * No locking is performed in this function.
4319 gst_pad_set_element_private (GstPad * pad, gpointer priv)
4321 pad->element_private = priv;
4325 * gst_pad_get_element_private:
4326 * @pad: the #GstPad to get the private data of.
4328 * Gets the private data of a pad.
4329 * No locking is performed in this function.
4331 * Returns: a #gpointer to the private data.
4334 gst_pad_get_element_private (GstPad * pad)
4336 return pad->element_private;
4340 * gst_pad_start_task:
4341 * @pad: the #GstPad to start the task of
4342 * @func: the task function to call
4343 * @data: data passed to the task function
4345 * Starts a task that repeatedly calls @func with @data. This function
4346 * is mostly used in pad activation functions to start the dataflow.
4347 * The #GST_PAD_STREAM_LOCK of @pad will automatically be acquired
4348 * before @func is called.
4350 * Returns: a %TRUE if the task could be started.
4353 gst_pad_start_task (GstPad * pad, GstTaskFunction func, gpointer data)
4357 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
4358 g_return_val_if_fail (func != NULL, FALSE);
4360 GST_DEBUG_OBJECT (pad, "start task");
4362 GST_OBJECT_LOCK (pad);
4363 task = GST_PAD_TASK (pad);
4365 task = gst_task_create (func, data);
4366 gst_task_set_lock (task, GST_PAD_GET_STREAM_LOCK (pad));
4367 GST_PAD_TASK (pad) = task;
4368 GST_DEBUG_OBJECT (pad, "created task");
4370 gst_task_start (task);
4371 GST_OBJECT_UNLOCK (pad);
4377 * gst_pad_pause_task:
4378 * @pad: the #GstPad to pause the task of
4380 * Pause the task of @pad. This function will also wait until the
4381 * function executed by the task is finished if this function is not
4382 * called from the task function.
4384 * Returns: a TRUE if the task could be paused or FALSE when the pad
4388 gst_pad_pause_task (GstPad * pad)
4392 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
4394 GST_DEBUG_OBJECT (pad, "pause task");
4396 GST_OBJECT_LOCK (pad);
4397 task = GST_PAD_TASK (pad);
4400 gst_task_pause (task);
4401 GST_OBJECT_UNLOCK (pad);
4403 GST_PAD_STREAM_LOCK (pad);
4404 GST_PAD_STREAM_UNLOCK (pad);
4410 GST_DEBUG_OBJECT (pad, "pad has no task");
4411 GST_OBJECT_UNLOCK (pad);
4417 * gst_pad_stop_task:
4418 * @pad: the #GstPad to stop the task of
4420 * Stop the task of @pad. This function will also make sure that the
4421 * function executed by the task will effectively stop if not called
4422 * from the GstTaskFunction.
4424 * This function will deadlock if called from the GstTaskFunction of
4425 * the task. Use gst_task_pause() instead.
4427 * Regardless of whether the pad has a task, the stream lock is acquired and
4428 * released so as to ensure that streaming through this pad has finished.
4430 * Returns: a TRUE if the task could be stopped or FALSE on error.
4433 gst_pad_stop_task (GstPad * pad)
4437 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
4439 GST_DEBUG_OBJECT (pad, "stop task");
4441 GST_OBJECT_LOCK (pad);
4442 task = GST_PAD_TASK (pad);
4445 GST_PAD_TASK (pad) = NULL;
4446 gst_task_stop (task);
4447 GST_OBJECT_UNLOCK (pad);
4449 GST_PAD_STREAM_LOCK (pad);
4450 GST_PAD_STREAM_UNLOCK (pad);
4452 if (!gst_task_join (task))
4455 gst_object_unref (task);
4461 GST_DEBUG_OBJECT (pad, "no task");
4462 GST_OBJECT_UNLOCK (pad);
4464 GST_PAD_STREAM_LOCK (pad);
4465 GST_PAD_STREAM_UNLOCK (pad);
4467 /* this is not an error */
4472 /* this is bad, possibly the application tried to join the task from
4473 * the task's thread. We install the task again so that it will be stopped
4474 * again from the right thread next time hopefully. */
4475 GST_OBJECT_LOCK (pad);
4476 GST_DEBUG_OBJECT (pad, "join failed");
4477 /* we can only install this task if there was no other task */
4478 if (GST_PAD_TASK (pad) == NULL)
4479 GST_PAD_TASK (pad) = task;
4480 GST_OBJECT_UNLOCK (pad);