2 * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
3 * 2000 Wim Taymans <wtay@chello.be>
5 * gstpad.c: Pads for linking elements together
7 * This library is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Library General Public
9 * License as published by the Free Software Foundation; either
10 * version 2 of the License, or (at your option) any later version.
12 * This library is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Library General Public License for more details.
17 * You should have received a copy of the GNU Library General Public
18 * License along with this library; if not, write to the
19 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
20 * Boston, MA 02111-1307, USA.
24 * @short_description: Object contained by elements that allows links to
26 * @see_also: #GstPadTemplate, #GstElement, #GstEvent
28 * A #GstElement is linked to other elements via "pads", which are extremely
29 * light-weight generic link points.
30 * After two pads are retrieved from an element with gst_element_get_pad(),
31 * the pads can be link with gst_pad_link(). (For quick links,
32 * you can also use gst_element_link(), which will make the obvious
33 * link for you if it's straightforward.)
35 * Pads are typically created from a #GstPadTemplate with
36 * gst_pad_new_from_template().
38 * Pads have #GstCaps attached to it to describe the media type they are
39 * capable of dealing with. gst_pad_get_caps() and gst_pad_set_caps() are
40 * used to manipulate the caps of the pads.
41 * Pads created from a pad template cannot set capabilities that are
42 * incompatible with the pad template capabilities.
44 * Pads without pad templates can be created with gst_pad_new(),
45 * which takes a direction and a name as an argument. If the name is NULL,
46 * then a guaranteed unique name will be assigned to it.
48 * gst_pad_get_parent() will retrieve the #GstElement that owns the pad.
50 * A #GstElement creating a pad will typically use the various
51 * gst_pad_set_*_function() calls to register callbacks for various events
54 * GstElements will use gst_pad_push() and gst_pad_pull_range() to push out
55 * or pull in a buffer.
57 * To send a #GstEvent on a pad, use gst_pad_send_event() and
58 * gst_pad_push_event().
60 * Last reviewed on 2006-07-06 (0.10.9)
63 #include "gst_private.h"
66 #include "gstpadtemplate.h"
67 #include "gstenumtypes.h"
68 #include "gstmarshal.h"
73 #include "glib-compat-private.h"
75 GST_DEBUG_CATEGORY_STATIC (debug_dataflow);
76 #define GST_CAT_DEFAULT GST_CAT_PADS
78 /* Pad signals and args */
98 static void gst_pad_class_init (GstPadClass * klass);
99 static void gst_pad_init (GstPad * pad);
100 static void gst_pad_dispose (GObject * object);
101 static void gst_pad_finalize (GObject * object);
102 static void gst_pad_set_property (GObject * object, guint prop_id,
103 const GValue * value, GParamSpec * pspec);
104 static void gst_pad_get_property (GObject * object, guint prop_id,
105 GValue * value, GParamSpec * pspec);
107 static GstFlowReturn handle_pad_block (GstPad * pad);
108 static GstCaps *gst_pad_get_caps_unlocked (GstPad * pad);
109 static void gst_pad_set_pad_template (GstPad * pad, GstPadTemplate * templ);
110 static gboolean gst_pad_activate_default (GstPad * pad);
111 static gboolean gst_pad_acceptcaps_default (GstPad * pad, GstCaps * caps);
113 #ifndef GST_DISABLE_LOADSAVE
114 static xmlNodePtr gst_pad_save_thyself (GstObject * object, xmlNodePtr parent);
117 static GstObjectClass *parent_class = NULL;
118 static guint gst_pad_signals[LAST_SIGNAL] = { 0 };
120 /* quarks for probe signals */
121 static GQuark buffer_quark;
122 static GQuark event_quark;
131 static GstFlowQuarks flow_quarks[] = {
132 {GST_FLOW_CUSTOM_SUCCESS, "custom-success", 0},
133 {GST_FLOW_RESEND, "resend", 0},
134 {GST_FLOW_OK, "ok", 0},
135 {GST_FLOW_NOT_LINKED, "not-linked", 0},
136 {GST_FLOW_WRONG_STATE, "wrong-state", 0},
137 {GST_FLOW_UNEXPECTED, "unexpected", 0},
138 {GST_FLOW_NOT_NEGOTIATED, "not-negotiated", 0},
139 {GST_FLOW_ERROR, "error", 0},
140 {GST_FLOW_NOT_SUPPORTED, "not-supported", 0},
141 {GST_FLOW_CUSTOM_ERROR, "custom-error", 0},
148 * @ret: a #GstFlowReturn to get the name of.
150 * Gets a string representing the given flow return.
152 * Returns: a static string with the name of the flow return.
154 G_CONST_RETURN gchar *
155 gst_flow_get_name (GstFlowReturn ret)
159 ret = CLAMP (ret, GST_FLOW_CUSTOM_ERROR, GST_FLOW_CUSTOM_SUCCESS);
161 for (i = 0; flow_quarks[i].name; i++) {
162 if (ret == flow_quarks[i].ret)
163 return flow_quarks[i].name;
170 * @ret: a #GstFlowReturn to get the quark of.
172 * Get the unique quark for the given GstFlowReturn.
174 * Returns: the quark associated with the flow return or 0 if an
175 * invalid return was specified.
178 gst_flow_to_quark (GstFlowReturn ret)
182 ret = CLAMP (ret, GST_FLOW_CUSTOM_ERROR, GST_FLOW_CUSTOM_SUCCESS);
184 for (i = 0; flow_quarks[i].name; i++) {
185 if (ret == flow_quarks[i].ret)
186 return flow_quarks[i].quark;
192 gst_pad_get_type (void)
194 static GType gst_pad_type = 0;
196 if (G_UNLIKELY (gst_pad_type == 0)) {
197 static const GTypeInfo pad_info = {
198 sizeof (GstPadClass), NULL, NULL,
199 (GClassInitFunc) gst_pad_class_init, NULL, NULL,
202 (GInstanceInitFunc) gst_pad_init, NULL
206 gst_pad_type = g_type_register_static (GST_TYPE_OBJECT, "GstPad",
209 buffer_quark = g_quark_from_static_string ("buffer");
210 event_quark = g_quark_from_static_string ("event");
212 for (i = 0; flow_quarks[i].name; i++) {
213 flow_quarks[i].quark = g_quark_from_static_string (flow_quarks[i].name);
216 GST_DEBUG_CATEGORY_INIT (debug_dataflow, "GST_DATAFLOW",
217 GST_DEBUG_BOLD | GST_DEBUG_FG_GREEN, "dataflow inside pads");
223 _gst_do_pass_data_accumulator (GSignalInvocationHint * ihint,
224 GValue * return_accu, const GValue * handler_return, gpointer dummy)
226 gboolean ret = g_value_get_boolean (handler_return);
228 GST_DEBUG ("accumulated %d", ret);
229 g_value_set_boolean (return_accu, ret);
235 default_have_data (GstPad * pad, GstMiniObject * o)
241 gst_pad_class_init (GstPadClass * klass)
243 GObjectClass *gobject_class;
244 GstObjectClass *gstobject_class;
246 gobject_class = G_OBJECT_CLASS (klass);
247 gstobject_class = GST_OBJECT_CLASS (klass);
249 parent_class = g_type_class_peek_parent (klass);
251 gobject_class->dispose = GST_DEBUG_FUNCPTR (gst_pad_dispose);
252 gobject_class->finalize = GST_DEBUG_FUNCPTR (gst_pad_finalize);
253 gobject_class->set_property = GST_DEBUG_FUNCPTR (gst_pad_set_property);
254 gobject_class->get_property = GST_DEBUG_FUNCPTR (gst_pad_get_property);
258 * @pad: the pad that emitted the signal
259 * @peer: the peer pad that has been connected
261 * Signals that a pad has been linked to the peer pad.
263 gst_pad_signals[PAD_LINKED] =
264 g_signal_new ("linked", G_TYPE_FROM_CLASS (klass), G_SIGNAL_RUN_LAST,
265 G_STRUCT_OFFSET (GstPadClass, linked), NULL, NULL,
266 gst_marshal_VOID__OBJECT, G_TYPE_NONE, 1, GST_TYPE_PAD);
269 * @pad: the pad that emitted the signal
270 * @peer: the peer pad that has been disconnected
272 * Signals that a pad has been unlinked from the peer pad.
274 gst_pad_signals[PAD_UNLINKED] =
275 g_signal_new ("unlinked", G_TYPE_FROM_CLASS (klass), G_SIGNAL_RUN_LAST,
276 G_STRUCT_OFFSET (GstPadClass, unlinked), NULL, NULL,
277 gst_marshal_VOID__OBJECT, G_TYPE_NONE, 1, GST_TYPE_PAD);
279 * GstPad::request-link:
280 * @pad: the pad that emitted the signal
281 * @peer: the peer pad for which a connection is requested
283 * Signals that a pad connection has been requested.
285 gst_pad_signals[PAD_REQUEST_LINK] =
286 g_signal_new ("request-link", G_TYPE_FROM_CLASS (klass),
287 G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GstPadClass, request_link), NULL,
288 NULL, gst_marshal_VOID__OBJECT, G_TYPE_NONE, 0);
292 * @pad: the pad that emitted the signal
293 * @mini_obj: new data
295 * Signals that new data is available on the pad. This signal is used
296 * internally for implementing pad probes.
297 * See gst_pad_add_*_probe functions.
299 * Returns: %TRUE to keep the data, %FALSE to drop it
301 gst_pad_signals[PAD_HAVE_DATA] =
302 g_signal_new ("have-data", G_TYPE_FROM_CLASS (klass),
303 G_SIGNAL_RUN_LAST | G_SIGNAL_DETAILED,
304 G_STRUCT_OFFSET (GstPadClass, have_data),
305 _gst_do_pass_data_accumulator,
306 NULL, gst_marshal_BOOLEAN__POINTER, G_TYPE_BOOLEAN, 1,
307 GST_TYPE_MINI_OBJECT);
309 g_object_class_install_property (gobject_class, PAD_PROP_CAPS,
310 g_param_spec_boxed ("caps", "Caps", "The capabilities of the pad",
311 GST_TYPE_CAPS, G_PARAM_READABLE));
312 g_object_class_install_property (gobject_class, PAD_PROP_DIRECTION,
313 g_param_spec_enum ("direction", "Direction", "The direction of the pad",
314 GST_TYPE_PAD_DIRECTION, GST_PAD_UNKNOWN,
315 G_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY));
316 /* FIXME, Make G_PARAM_CONSTRUCT_ONLY when we fix ghostpads. */
317 g_object_class_install_property (gobject_class, PAD_PROP_TEMPLATE,
318 g_param_spec_object ("template", "Template",
319 "The GstPadTemplate of this pad", GST_TYPE_PAD_TEMPLATE,
322 #ifndef GST_DISABLE_LOADSAVE
323 gstobject_class->save_thyself = GST_DEBUG_FUNCPTR (gst_pad_save_thyself);
325 gstobject_class->path_string_separator = ".";
327 klass->have_data = default_have_data;
331 gst_pad_init (GstPad * pad)
333 GST_PAD_DIRECTION (pad) = GST_PAD_UNKNOWN;
334 GST_PAD_PEER (pad) = NULL;
336 GST_PAD_CHAINFUNC (pad) = NULL;
338 GST_PAD_LINKFUNC (pad) = NULL;
340 GST_PAD_CAPS (pad) = NULL;
341 GST_PAD_GETCAPSFUNC (pad) = NULL;
343 GST_PAD_ACTIVATEFUNC (pad) = GST_DEBUG_FUNCPTR (gst_pad_activate_default);
344 GST_PAD_EVENTFUNC (pad) = GST_DEBUG_FUNCPTR (gst_pad_event_default);
345 GST_PAD_QUERYTYPEFUNC (pad) =
346 GST_DEBUG_FUNCPTR (gst_pad_get_query_types_default);
347 GST_PAD_QUERYFUNC (pad) = GST_DEBUG_FUNCPTR (gst_pad_query_default);
348 GST_PAD_INTLINKFUNC (pad) =
349 GST_DEBUG_FUNCPTR (gst_pad_get_internal_links_default);
350 GST_PAD_ACCEPTCAPSFUNC (pad) = GST_DEBUG_FUNCPTR (gst_pad_acceptcaps_default);
352 pad->do_buffer_signals = 0;
353 pad->do_event_signals = 0;
355 GST_PAD_SET_FLUSHING (pad);
357 pad->preroll_lock = g_mutex_new ();
358 pad->preroll_cond = g_cond_new ();
360 pad->stream_rec_lock = g_new (GStaticRecMutex, 1);
361 g_static_rec_mutex_init (pad->stream_rec_lock);
363 pad->block_cond = g_cond_new ();
367 gst_pad_dispose (GObject * object)
369 GstPad *pad = GST_PAD (object);
371 GST_CAT_DEBUG_OBJECT (GST_CAT_REFCOUNTING, pad, "dispose");
373 /* we don't hold a ref to the peer so we can just set the
375 GST_PAD_PEER (pad) = NULL;
378 gst_caps_replace (&GST_PAD_CAPS (pad), NULL);
380 gst_pad_set_pad_template (pad, NULL);
382 G_OBJECT_CLASS (parent_class)->dispose (object);
386 gst_pad_finalize (GObject * object)
388 GstPad *pad = GST_PAD (object);
391 /* in case the task is still around, clean it up */
392 if ((task = GST_PAD_TASK (pad))) {
393 gst_task_join (task);
394 GST_PAD_TASK (pad) = NULL;
395 gst_object_unref (task);
398 if (pad->stream_rec_lock) {
399 g_static_rec_mutex_free (pad->stream_rec_lock);
400 g_free (pad->stream_rec_lock);
401 pad->stream_rec_lock = NULL;
403 if (pad->preroll_lock) {
404 g_mutex_free (pad->preroll_lock);
405 g_cond_free (pad->preroll_cond);
406 pad->preroll_lock = NULL;
407 pad->preroll_cond = NULL;
409 if (pad->block_cond) {
410 g_cond_free (pad->block_cond);
411 pad->block_cond = NULL;
414 G_OBJECT_CLASS (parent_class)->finalize (object);
418 gst_pad_set_property (GObject * object, guint prop_id,
419 const GValue * value, GParamSpec * pspec)
421 g_return_if_fail (GST_IS_PAD (object));
424 case PAD_PROP_DIRECTION:
425 GST_PAD_DIRECTION (object) = g_value_get_enum (value);
427 case PAD_PROP_TEMPLATE:
428 gst_pad_set_pad_template (GST_PAD_CAST (object),
429 (GstPadTemplate *) g_value_get_object (value));
432 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
438 gst_pad_get_property (GObject * object, guint prop_id,
439 GValue * value, GParamSpec * pspec)
441 g_return_if_fail (GST_IS_PAD (object));
445 GST_OBJECT_LOCK (object);
446 g_value_set_boxed (value, GST_PAD_CAPS (object));
447 GST_OBJECT_UNLOCK (object);
449 case PAD_PROP_DIRECTION:
450 g_value_set_enum (value, GST_PAD_DIRECTION (object));
452 case PAD_PROP_TEMPLATE:
453 g_value_set_object (value, GST_PAD_PAD_TEMPLATE (object));
456 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
463 * @name: the name of the new pad.
464 * @direction: the #GstPadDirection of the pad.
466 * Creates a new pad with the given name in the given direction.
467 * If name is NULL, a guaranteed unique name (across all pads)
469 * This function makes a copy of the name so you can safely free the name.
471 * Returns: a new #GstPad, or NULL in case of an error.
476 gst_pad_new (const gchar * name, GstPadDirection direction)
478 return g_object_new (GST_TYPE_PAD,
479 "name", name, "direction", direction, NULL);
483 * gst_pad_new_from_template:
484 * @templ: the pad template to use
485 * @name: the name of the element
487 * Creates a new pad with the given name from the given template.
488 * If name is NULL, a guaranteed unique name (across all pads)
490 * This function makes a copy of the name so you can safely free the name.
492 * Returns: a new #GstPad, or NULL in case of an error.
495 gst_pad_new_from_template (GstPadTemplate * templ, const gchar * name)
497 g_return_val_if_fail (GST_IS_PAD_TEMPLATE (templ), NULL);
499 return g_object_new (GST_TYPE_PAD,
500 "name", name, "direction", templ->direction, "template", templ, NULL);
504 * gst_pad_new_from_static_template:
505 * @templ: the #GstStaticPadTemplate to use
506 * @name: the name of the element
508 * Creates a new pad with the given name from the given static template.
509 * If name is NULL, a guaranteed unique name (across all pads)
511 * This function makes a copy of the name so you can safely free the name.
513 * Returns: a new #GstPad, or NULL in case of an error.
516 gst_pad_new_from_static_template (GstStaticPadTemplate * templ,
520 GstPadTemplate *template;
522 template = gst_static_pad_template_get (templ);
523 pad = gst_pad_new_from_template (template, name);
524 gst_object_unref (template);
529 * gst_pad_get_direction:
530 * @pad: a #GstPad to get the direction of.
532 * Gets the direction of the pad. The direction of the pad is
533 * decided at construction time so this function does not take
536 * Returns: the #GstPadDirection of the pad.
541 gst_pad_get_direction (GstPad * pad)
543 GstPadDirection result;
545 /* PAD_UNKNOWN is a little silly but we need some sort of
546 * error return value */
547 g_return_val_if_fail (GST_IS_PAD (pad), GST_PAD_UNKNOWN);
549 GST_OBJECT_LOCK (pad);
550 result = GST_PAD_DIRECTION (pad);
551 GST_OBJECT_UNLOCK (pad);
557 gst_pad_activate_default (GstPad * pad)
559 return gst_pad_activate_push (pad, TRUE);
563 pre_activate (GstPad * pad, GstActivateMode new_mode)
566 case GST_ACTIVATE_PUSH:
567 case GST_ACTIVATE_PULL:
568 GST_OBJECT_LOCK (pad);
569 GST_DEBUG_OBJECT (pad, "setting ACTIVATE_MODE %d, unset flushing",
571 GST_PAD_UNSET_FLUSHING (pad);
572 GST_PAD_ACTIVATE_MODE (pad) = new_mode;
573 GST_OBJECT_UNLOCK (pad);
575 case GST_ACTIVATE_NONE:
576 GST_OBJECT_LOCK (pad);
577 GST_DEBUG_OBJECT (pad, "setting ACTIVATE_MODE NONE, set flushing");
578 GST_PAD_SET_FLUSHING (pad);
579 /* unlock blocked pads so element can resume and stop */
580 GST_PAD_BLOCK_BROADCAST (pad);
581 GST_OBJECT_UNLOCK (pad);
587 post_activate (GstPad * pad, GstActivateMode new_mode)
590 case GST_ACTIVATE_PUSH:
591 case GST_ACTIVATE_PULL:
594 case GST_ACTIVATE_NONE:
595 /* ensures that streaming stops */
596 GST_PAD_STREAM_LOCK (pad);
597 /* while we're at it set activation mode */
598 GST_OBJECT_LOCK (pad);
599 GST_DEBUG_OBJECT (pad, "setting ACTIVATE_MODE %d", new_mode);
600 GST_PAD_ACTIVATE_MODE (pad) = new_mode;
601 GST_OBJECT_UNLOCK (pad);
602 GST_PAD_STREAM_UNLOCK (pad);
608 * gst_pad_set_active:
609 * @pad: the #GstPad to activate or deactivate.
610 * @active: whether or not the pad should be active.
612 * Activates or deactivates the given pad.
613 * Normally called from within core state change functions.
615 * If @active, makes sure the pad is active. If it is already active, either in
616 * push or pull mode, just return. Otherwise dispatches to the pad's activate
617 * function to perform the actual activation.
619 * If not @active, checks the pad's current mode and calls
620 * gst_pad_activate_push() or gst_pad_activate_pull(), as appropriate, with a
623 * Returns: #TRUE if the operation was successful.
628 gst_pad_set_active (GstPad * pad, gboolean active)
631 gboolean ret = FALSE;
633 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
635 GST_OBJECT_LOCK (pad);
636 old = GST_PAD_ACTIVATE_MODE (pad);
637 GST_OBJECT_UNLOCK (pad);
641 case GST_ACTIVATE_PUSH:
642 case GST_ACTIVATE_PULL:
645 case GST_ACTIVATE_NONE:
646 ret = (GST_PAD_ACTIVATEFUNC (pad)) (pad);
651 case GST_ACTIVATE_PUSH:
652 ret = gst_pad_activate_push (pad, FALSE);
654 case GST_ACTIVATE_PULL:
655 ret = gst_pad_activate_pull (pad, FALSE);
657 case GST_ACTIVATE_NONE:
664 GST_OBJECT_LOCK (pad);
666 g_critical ("Failed to deactivate pad %s:%s, very bad",
667 GST_DEBUG_PAD_NAME (pad));
669 GST_WARNING ("Failed to activate pad %s:%s", GST_DEBUG_PAD_NAME (pad));
671 GST_OBJECT_UNLOCK (pad);
678 * gst_pad_activate_pull:
679 * @pad: the #GstPad to activate or deactivate.
680 * @active: whether or not the pad should be active.
682 * Activates or deactivates the given pad in pull mode via dispatching to the
683 * pad's activatepullfunc. For use from within pad activation functions only.
684 * When called on sink pads, will first proxy the call to the peer pad, which is
685 * expected to activate its internally linked pads from within its activate_pull
688 * If you don't know what this is, you probably don't want to call it.
690 * Returns: TRUE if the operation was successful.
695 gst_pad_activate_pull (GstPad * pad, gboolean active)
697 GstActivateMode old, new;
700 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
702 GST_OBJECT_LOCK (pad);
703 old = GST_PAD_ACTIVATE_MODE (pad);
704 GST_OBJECT_UNLOCK (pad);
708 case GST_ACTIVATE_PULL:
710 case GST_ACTIVATE_PUSH:
711 /* pad was activate in the wrong direction, deactivate it
712 * and reactivate it in pull mode */
713 if (G_UNLIKELY (!gst_pad_activate_push (pad, FALSE)))
714 goto deactivate_failed;
715 /* fallthrough, pad is deactivated now. */
716 case GST_ACTIVATE_NONE:
721 case GST_ACTIVATE_NONE:
723 case GST_ACTIVATE_PUSH:
724 /* pad was activated in the other direction, deactivate it
725 * in push mode, this should not happen... */
726 if (G_UNLIKELY (!gst_pad_activate_push (pad, FALSE)))
727 goto deactivate_failed;
728 /* everything is fine now */
730 case GST_ACTIVATE_PULL:
735 if (gst_pad_get_direction (pad) == GST_PAD_SINK) {
736 if ((peer = gst_pad_get_peer (pad))) {
737 if (G_UNLIKELY (!gst_pad_activate_pull (peer, active)))
739 gst_object_unref (peer);
744 if (G_UNLIKELY (GST_PAD_GETRANGEFUNC (pad) == NULL))
745 goto failure; /* Can't activate pull on a src without a
749 new = active ? GST_ACTIVATE_PULL : GST_ACTIVATE_NONE;
750 pre_activate (pad, new);
752 if (GST_PAD_ACTIVATEPULLFUNC (pad)) {
753 if (G_UNLIKELY (!GST_PAD_ACTIVATEPULLFUNC (pad) (pad, active)))
756 /* can happen for sinks of passthrough elements */
759 post_activate (pad, new);
761 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "%s in pull mode",
762 active ? "activated" : "deactivated");
768 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "already %s in pull mode",
769 active ? "activated" : "deactivated");
774 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
775 "failed to %s in switch to pull from mode %d",
776 (active ? "activate" : "deactivate"), old);
781 GST_OBJECT_LOCK (peer);
782 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
783 "activate_pull on peer (%s:%s) failed", GST_DEBUG_PAD_NAME (peer));
784 GST_OBJECT_UNLOCK (peer);
785 gst_object_unref (peer);
790 GST_CAT_INFO_OBJECT (GST_CAT_PADS, pad, "can't activate unlinked sink "
796 GST_OBJECT_LOCK (pad);
797 GST_CAT_INFO_OBJECT (GST_CAT_PADS, pad, "failed to %s in pull mode",
798 active ? "activate" : "deactivate");
799 GST_PAD_SET_FLUSHING (pad);
800 GST_PAD_ACTIVATE_MODE (pad) = old;
801 GST_OBJECT_UNLOCK (pad);
807 * gst_pad_activate_push:
808 * @pad: the #GstPad to activate or deactivate.
809 * @active: whether the pad should be active or not.
811 * Activates or deactivates the given pad in push mode via dispatching to the
812 * pad's activatepushfunc. For use from within pad activation functions only.
814 * If you don't know what this is, you probably don't want to call it.
816 * Returns: %TRUE if the operation was successful.
821 gst_pad_activate_push (GstPad * pad, gboolean active)
823 GstActivateMode old, new;
825 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
826 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "trying to set %s in push mode",
827 active ? "activated" : "deactivated");
829 GST_OBJECT_LOCK (pad);
830 old = GST_PAD_ACTIVATE_MODE (pad);
831 GST_OBJECT_UNLOCK (pad);
835 case GST_ACTIVATE_PUSH:
837 case GST_ACTIVATE_PULL:
838 /* pad was activate in the wrong direction, deactivate it
839 * an reactivate it in push mode */
840 if (G_UNLIKELY (!gst_pad_activate_pull (pad, FALSE)))
841 goto deactivate_failed;
842 /* fallthrough, pad is deactivated now. */
843 case GST_ACTIVATE_NONE:
848 case GST_ACTIVATE_NONE:
850 case GST_ACTIVATE_PULL:
851 /* pad was activated in the other direction, deactivate it
852 * in pull mode, this should not happen... */
853 if (G_UNLIKELY (!gst_pad_activate_pull (pad, FALSE)))
854 goto deactivate_failed;
855 /* everything is fine now */
857 case GST_ACTIVATE_PUSH:
862 new = active ? GST_ACTIVATE_PUSH : GST_ACTIVATE_NONE;
863 pre_activate (pad, new);
865 if (GST_PAD_ACTIVATEPUSHFUNC (pad)) {
866 if (G_UNLIKELY (!GST_PAD_ACTIVATEPUSHFUNC (pad) (pad, active))) {
870 /* quite ok, element relies on state change func to prepare itself */
873 post_activate (pad, new);
875 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "%s in push mode",
876 active ? "activated" : "deactivated");
881 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "already %s in push mode",
882 active ? "activated" : "deactivated");
887 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
888 "failed to %s in switch to push from mode %d",
889 (active ? "activate" : "deactivate"), old);
894 GST_OBJECT_LOCK (pad);
895 GST_CAT_INFO_OBJECT (GST_CAT_PADS, pad, "failed to %s in push mode",
896 active ? "activate" : "deactivate");
897 GST_PAD_SET_FLUSHING (pad);
898 GST_PAD_ACTIVATE_MODE (pad) = old;
899 GST_OBJECT_UNLOCK (pad);
906 * @pad: the #GstPad to query
908 * Query if a pad is active
910 * Returns: TRUE if the pad is active.
915 gst_pad_is_active (GstPad * pad)
917 gboolean result = FALSE;
919 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
921 GST_OBJECT_LOCK (pad);
922 result = GST_PAD_MODE_ACTIVATE (GST_PAD_ACTIVATE_MODE (pad));
923 GST_OBJECT_UNLOCK (pad);
929 * gst_pad_set_blocked_async:
930 * @pad: the #GstPad to block or unblock
931 * @blocked: boolean indicating whether the pad should be blocked or unblocked
932 * @callback: #GstPadBlockCallback that will be called when the
934 * @user_data: user data passed to the callback
936 * Blocks or unblocks the dataflow on a pad. The provided callback
937 * is called when the operation succeeds; this happens right before the next
938 * attempt at pushing a buffer on the pad.
940 * This can take a while as the pad can only become blocked when real dataflow
942 * When the pipeline is stalled, for example in PAUSED, this can
943 * take an indeterminate amount of time.
944 * You can pass NULL as the callback to make this call block. Be careful with
945 * this blocking call as it might not return for reasons stated above.
947 * Returns: TRUE if the pad could be blocked. This function can fail
948 * if wrong parameters were passed or the pad was already in the
954 gst_pad_set_blocked_async (GstPad * pad, gboolean blocked,
955 GstPadBlockCallback callback, gpointer user_data)
957 gboolean was_blocked = FALSE;
959 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
961 GST_OBJECT_LOCK (pad);
963 was_blocked = GST_PAD_IS_BLOCKED (pad);
965 if (G_UNLIKELY (was_blocked == blocked))
966 goto had_right_state;
969 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "blocking pad");
971 GST_OBJECT_FLAG_SET (pad, GST_PAD_BLOCKED);
972 pad->block_callback = callback;
973 pad->block_data = user_data;
975 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "waiting for block");
976 GST_PAD_BLOCK_WAIT (pad);
977 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "blocked");
980 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "unblocking pad");
982 GST_OBJECT_FLAG_UNSET (pad, GST_PAD_BLOCKED);
984 pad->block_callback = callback;
985 pad->block_data = user_data;
987 GST_PAD_BLOCK_BROADCAST (pad);
989 /* no callback, wait for the unblock to happen */
990 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "waiting for unblock");
991 GST_PAD_BLOCK_WAIT (pad);
992 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "unblocked");
995 GST_OBJECT_UNLOCK (pad);
1001 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
1002 "pad was in right state (%d)", was_blocked);
1003 GST_OBJECT_UNLOCK (pad);
1010 * gst_pad_set_blocked:
1011 * @pad: the #GstPad to block or unblock
1012 * @blocked: boolean indicating we should block or unblock
1014 * Blocks or unblocks the dataflow on a pad. This function is
1015 * a shortcut for gst_pad_set_blocked_async() with a NULL
1018 * Returns: TRUE if the pad could be blocked. This function can fail
1019 * wrong parameters were passed or the pad was already in the
1025 gst_pad_set_blocked (GstPad * pad, gboolean blocked)
1027 return gst_pad_set_blocked_async (pad, blocked, NULL, NULL);
1031 * gst_pad_is_blocked:
1032 * @pad: the #GstPad to query
1034 * Checks if the pad is blocked or not. This function returns the
1035 * last requested state of the pad. It is not certain that the pad
1036 * is actually blocking at this point (see gst_pad_is_blocking()).
1038 * Returns: TRUE if the pad is blocked.
1043 gst_pad_is_blocked (GstPad * pad)
1045 gboolean result = FALSE;
1047 g_return_val_if_fail (GST_IS_PAD (pad), result);
1049 GST_OBJECT_LOCK (pad);
1050 result = GST_OBJECT_FLAG_IS_SET (pad, GST_PAD_BLOCKED);
1051 GST_OBJECT_UNLOCK (pad);
1057 * gst_pad_is_blocking:
1058 * @pad: the #GstPad to query
1060 * Checks if the pad is blocking or not. This is a guaranteed state
1061 * of whether the pad is actually blocking on a #GstBuffer or a #GstEvent.
1063 * Returns: TRUE if the pad is blocking.
1070 gst_pad_is_blocking (GstPad * pad)
1072 gboolean result = FALSE;
1074 g_return_val_if_fail (GST_IS_PAD (pad), result);
1076 GST_OBJECT_LOCK (pad);
1077 /* the blocking flag is only valid if the pad is not flushing */
1078 result = GST_OBJECT_FLAG_IS_SET (pad, GST_PAD_BLOCKING) &&
1079 !GST_OBJECT_FLAG_IS_SET (pad, GST_PAD_FLUSHING);
1080 GST_OBJECT_UNLOCK (pad);
1086 * gst_pad_set_activate_function:
1088 * @activate: the #GstPadActivateFunction to set.
1090 * Sets the given activate function for @pad. The activate function will
1091 * dispatch to gst_pad_activate_push() or gst_pad_activate_pull() to perform
1092 * the actual activation. Only makes sense to set on sink pads.
1094 * Call this function if your sink pad can start a pull-based task.
1097 gst_pad_set_activate_function (GstPad * pad, GstPadActivateFunction activate)
1099 g_return_if_fail (GST_IS_PAD (pad));
1101 GST_PAD_ACTIVATEFUNC (pad) = activate;
1102 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "activatefunc set to %s",
1103 GST_DEBUG_FUNCPTR_NAME (activate));
1107 * gst_pad_set_activatepull_function:
1109 * @activatepull: the #GstPadActivateModeFunction to set.
1111 * Sets the given activate_pull function for the pad. An activate_pull function
1112 * prepares the element and any upstream connections for pulling. See XXX
1113 * part-activation.txt for details.
1116 gst_pad_set_activatepull_function (GstPad * pad,
1117 GstPadActivateModeFunction activatepull)
1119 g_return_if_fail (GST_IS_PAD (pad));
1121 GST_PAD_ACTIVATEPULLFUNC (pad) = activatepull;
1122 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "activatepullfunc set to %s",
1123 GST_DEBUG_FUNCPTR_NAME (activatepull));
1127 * gst_pad_set_activatepush_function:
1129 * @activatepush: the #GstPadActivateModeFunction to set.
1131 * Sets the given activate_push function for the pad. An activate_push function
1132 * prepares the element for pushing. See XXX part-activation.txt for details.
1135 gst_pad_set_activatepush_function (GstPad * pad,
1136 GstPadActivateModeFunction activatepush)
1138 g_return_if_fail (GST_IS_PAD (pad));
1140 GST_PAD_ACTIVATEPUSHFUNC (pad) = activatepush;
1141 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "activatepushfunc set to %s",
1142 GST_DEBUG_FUNCPTR_NAME (activatepush));
1146 * gst_pad_set_chain_function:
1147 * @pad: a sink #GstPad.
1148 * @chain: the #GstPadChainFunction to set.
1150 * Sets the given chain function for the pad. The chain function is called to
1151 * process a #GstBuffer input buffer. see #GstPadChainFunction for more details.
1154 gst_pad_set_chain_function (GstPad * pad, GstPadChainFunction chain)
1156 g_return_if_fail (GST_IS_PAD (pad));
1157 g_return_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SINK);
1159 GST_PAD_CHAINFUNC (pad) = chain;
1160 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "chainfunc set to %s",
1161 GST_DEBUG_FUNCPTR_NAME (chain));
1165 * gst_pad_set_getrange_function:
1166 * @pad: a source #GstPad.
1167 * @get: the #GstPadGetRangeFunction to set.
1169 * Sets the given getrange function for the pad. The getrange function is called to
1170 * produce a new #GstBuffer to start the processing pipeline. see
1171 * #GstPadGetRangeFunction for a description of the getrange function.
1174 gst_pad_set_getrange_function (GstPad * pad, GstPadGetRangeFunction get)
1176 g_return_if_fail (GST_IS_PAD (pad));
1177 g_return_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SRC);
1179 GST_PAD_GETRANGEFUNC (pad) = get;
1181 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "getrangefunc set to %s",
1182 GST_DEBUG_FUNCPTR_NAME (get));
1186 * gst_pad_set_checkgetrange_function:
1187 * @pad: a source #GstPad.
1188 * @check: the #GstPadCheckGetRangeFunction to set.
1190 * Sets the given checkgetrange function for the pad. Implement this function on
1191 * a pad if you dynamically support getrange based scheduling on the pad.
1194 gst_pad_set_checkgetrange_function (GstPad * pad,
1195 GstPadCheckGetRangeFunction check)
1197 g_return_if_fail (GST_IS_PAD (pad));
1198 g_return_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SRC);
1200 GST_PAD_CHECKGETRANGEFUNC (pad) = check;
1202 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "checkgetrangefunc set to %s",
1203 GST_DEBUG_FUNCPTR_NAME (check));
1207 * gst_pad_set_event_function:
1208 * @pad: a source #GstPad.
1209 * @event: the #GstPadEventFunction to set.
1211 * Sets the given event handler for the pad.
1214 gst_pad_set_event_function (GstPad * pad, GstPadEventFunction event)
1216 g_return_if_fail (GST_IS_PAD (pad));
1218 GST_PAD_EVENTFUNC (pad) = event;
1220 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "eventfunc for set to %s",
1221 GST_DEBUG_FUNCPTR_NAME (event));
1225 * gst_pad_set_query_function:
1226 * @pad: a #GstPad of either direction.
1227 * @query: the #GstPadQueryFunction to set.
1229 * Set the given query function for the pad.
1232 gst_pad_set_query_function (GstPad * pad, GstPadQueryFunction query)
1234 g_return_if_fail (GST_IS_PAD (pad));
1236 GST_PAD_QUERYFUNC (pad) = query;
1238 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "queryfunc set to %s",
1239 GST_DEBUG_FUNCPTR_NAME (query));
1243 * gst_pad_set_query_type_function:
1244 * @pad: a #GstPad of either direction.
1245 * @type_func: the #GstPadQueryTypeFunction to set.
1247 * Set the given query type function for the pad.
1250 gst_pad_set_query_type_function (GstPad * pad,
1251 GstPadQueryTypeFunction type_func)
1253 g_return_if_fail (GST_IS_PAD (pad));
1255 GST_PAD_QUERYTYPEFUNC (pad) = type_func;
1257 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "querytypefunc set to %s",
1258 GST_DEBUG_FUNCPTR_NAME (type_func));
1262 * gst_pad_get_query_types:
1265 * Get an array of supported queries that can be performed
1268 * Returns: a zero-terminated array of #GstQueryType.
1270 const GstQueryType *
1271 gst_pad_get_query_types (GstPad * pad)
1273 GstPadQueryTypeFunction func;
1275 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
1277 if (G_UNLIKELY ((func = GST_PAD_QUERYTYPEFUNC (pad)) == NULL))
1289 gst_pad_get_query_types_dispatcher (GstPad * pad, const GstQueryType ** data)
1291 *data = gst_pad_get_query_types (pad);
1297 * gst_pad_get_query_types_default:
1300 * Invoke the default dispatcher for the query types on
1303 * Returns: an zero-terminated array of #GstQueryType, or NULL if none of the
1304 * internally-linked pads has a query types function.
1306 const GstQueryType *
1307 gst_pad_get_query_types_default (GstPad * pad)
1309 GstQueryType *result = NULL;
1311 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
1313 gst_pad_dispatcher (pad, (GstPadDispatcherFunction)
1314 gst_pad_get_query_types_dispatcher, &result);
1320 * gst_pad_set_internal_link_function:
1321 * @pad: a #GstPad of either direction.
1322 * @intlink: the #GstPadIntLinkFunction to set.
1324 * Sets the given internal link function for the pad.
1327 gst_pad_set_internal_link_function (GstPad * pad, GstPadIntLinkFunction intlink)
1329 g_return_if_fail (GST_IS_PAD (pad));
1331 GST_PAD_INTLINKFUNC (pad) = intlink;
1332 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "internal link set to %s",
1333 GST_DEBUG_FUNCPTR_NAME (intlink));
1337 * gst_pad_set_link_function:
1339 * @link: the #GstPadLinkFunction to set.
1341 * Sets the given link function for the pad. It will be called when
1342 * the pad is linked with another pad.
1344 * The return value #GST_PAD_LINK_OK should be used when the connection can be
1347 * The return value #GST_PAD_LINK_REFUSED should be used when the connection
1348 * cannot be made for some reason.
1350 * If @link is installed on a source pad, it should call the #GstPadLinkFunction
1351 * of the peer sink pad, if present.
1354 gst_pad_set_link_function (GstPad * pad, GstPadLinkFunction link)
1356 g_return_if_fail (GST_IS_PAD (pad));
1358 GST_PAD_LINKFUNC (pad) = link;
1359 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "linkfunc set to %s",
1360 GST_DEBUG_FUNCPTR_NAME (link));
1364 * gst_pad_set_unlink_function:
1366 * @unlink: the #GstPadUnlinkFunction to set.
1368 * Sets the given unlink function for the pad. It will be called
1369 * when the pad is unlinked.
1372 gst_pad_set_unlink_function (GstPad * pad, GstPadUnlinkFunction unlink)
1374 g_return_if_fail (GST_IS_PAD (pad));
1376 GST_PAD_UNLINKFUNC (pad) = unlink;
1377 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "unlinkfunc set to %s",
1378 GST_DEBUG_FUNCPTR_NAME (unlink));
1382 * gst_pad_set_getcaps_function:
1384 * @getcaps: the #GstPadGetCapsFunction to set.
1386 * Sets the given getcaps function for the pad. @getcaps should return the
1387 * allowable caps for a pad in the context of the element's state, its link to
1388 * other elements, and the devices or files it has opened. These caps must be a
1389 * subset of the pad template caps. In the NULL state with no links, @getcaps
1390 * should ideally return the same caps as the pad template. In rare
1391 * circumstances, an object property can affect the caps returned by @getcaps,
1392 * but this is discouraged.
1394 * You do not need to call this function if @pad's allowed caps are always the
1395 * same as the pad template caps. This can only be true if the padtemplate
1396 * has fixed simple caps.
1398 * For most filters, the caps returned by @getcaps is directly affected by the
1399 * allowed caps on other pads. For demuxers and decoders, the caps returned by
1400 * the srcpad's getcaps function is directly related to the stream data. Again,
1401 * @getcaps should return the most specific caps it reasonably can, since this
1402 * helps with autoplugging.
1404 * Note that the return value from @getcaps is owned by the caller, so the caller
1405 * should unref the caps after usage.
1408 gst_pad_set_getcaps_function (GstPad * pad, GstPadGetCapsFunction getcaps)
1410 g_return_if_fail (GST_IS_PAD (pad));
1412 GST_PAD_GETCAPSFUNC (pad) = getcaps;
1413 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "getcapsfunc set to %s",
1414 GST_DEBUG_FUNCPTR_NAME (getcaps));
1418 * gst_pad_set_acceptcaps_function:
1420 * @acceptcaps: the #GstPadAcceptCapsFunction to set.
1422 * Sets the given acceptcaps function for the pad. The acceptcaps function
1423 * will be called to check if the pad can accept the given caps. Setting the
1424 * acceptcaps function to NULL restores the default behaviour of allowing
1425 * any caps that matches the caps from gst_pad_get_caps.
1428 gst_pad_set_acceptcaps_function (GstPad * pad,
1429 GstPadAcceptCapsFunction acceptcaps)
1431 g_return_if_fail (GST_IS_PAD (pad));
1433 GST_PAD_ACCEPTCAPSFUNC (pad) = acceptcaps;
1434 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "acceptcapsfunc set to %s",
1435 GST_DEBUG_FUNCPTR_NAME (acceptcaps));
1439 * gst_pad_set_fixatecaps_function:
1441 * @fixatecaps: the #GstPadFixateCapsFunction to set.
1443 * Sets the given fixatecaps function for the pad. The fixatecaps function
1444 * will be called whenever the default values for a GstCaps needs to be
1448 gst_pad_set_fixatecaps_function (GstPad * pad,
1449 GstPadFixateCapsFunction fixatecaps)
1451 g_return_if_fail (GST_IS_PAD (pad));
1453 GST_PAD_FIXATECAPSFUNC (pad) = fixatecaps;
1454 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "fixatecapsfunc set to %s",
1455 GST_DEBUG_FUNCPTR_NAME (fixatecaps));
1459 * gst_pad_set_setcaps_function:
1461 * @setcaps: the #GstPadSetCapsFunction to set.
1463 * Sets the given setcaps function for the pad. The setcaps function
1464 * will be called whenever a buffer with a new media type is pushed or
1465 * pulled from the pad. The pad/element needs to update its internal
1466 * structures to process the new media type. If this new type is not
1467 * acceptable, the setcaps function should return FALSE.
1470 gst_pad_set_setcaps_function (GstPad * pad, GstPadSetCapsFunction setcaps)
1472 g_return_if_fail (GST_IS_PAD (pad));
1474 GST_PAD_SETCAPSFUNC (pad) = setcaps;
1475 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "setcapsfunc set to %s",
1476 GST_DEBUG_FUNCPTR_NAME (setcaps));
1480 * gst_pad_set_bufferalloc_function:
1481 * @pad: a sink #GstPad.
1482 * @bufalloc: the #GstPadBufferAllocFunction to set.
1484 * Sets the given bufferalloc function for the pad. Note that the
1485 * bufferalloc function can only be set on sinkpads.
1488 gst_pad_set_bufferalloc_function (GstPad * pad,
1489 GstPadBufferAllocFunction bufalloc)
1491 g_return_if_fail (GST_IS_PAD (pad));
1492 g_return_if_fail (GST_PAD_IS_SINK (pad));
1494 GST_PAD_BUFFERALLOCFUNC (pad) = bufalloc;
1495 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "bufferallocfunc set to %s",
1496 GST_DEBUG_FUNCPTR_NAME (bufalloc));
1501 * @srcpad: the source #GstPad to unlink.
1502 * @sinkpad: the sink #GstPad to unlink.
1504 * Unlinks the source pad from the sink pad. Will emit the "unlinked" signal on
1507 * Returns: TRUE if the pads were unlinked. This function returns FALSE if
1508 * the pads were not linked together.
1513 gst_pad_unlink (GstPad * srcpad, GstPad * sinkpad)
1515 g_return_val_if_fail (GST_IS_PAD (srcpad), FALSE);
1516 g_return_val_if_fail (GST_IS_PAD (sinkpad), FALSE);
1518 GST_CAT_INFO (GST_CAT_ELEMENT_PADS, "unlinking %s:%s(%p) and %s:%s(%p)",
1519 GST_DEBUG_PAD_NAME (srcpad), srcpad,
1520 GST_DEBUG_PAD_NAME (sinkpad), sinkpad);
1522 GST_OBJECT_LOCK (srcpad);
1524 if (G_UNLIKELY (GST_PAD_DIRECTION (srcpad) != GST_PAD_SRC))
1527 GST_OBJECT_LOCK (sinkpad);
1529 if (G_UNLIKELY (GST_PAD_DIRECTION (sinkpad) != GST_PAD_SINK))
1532 if (G_UNLIKELY (GST_PAD_PEER (srcpad) != sinkpad))
1533 goto not_linked_together;
1535 if (GST_PAD_UNLINKFUNC (srcpad)) {
1536 GST_PAD_UNLINKFUNC (srcpad) (srcpad);
1538 if (GST_PAD_UNLINKFUNC (sinkpad)) {
1539 GST_PAD_UNLINKFUNC (sinkpad) (sinkpad);
1542 /* first clear peers */
1543 GST_PAD_PEER (srcpad) = NULL;
1544 GST_PAD_PEER (sinkpad) = NULL;
1546 GST_OBJECT_UNLOCK (sinkpad);
1547 GST_OBJECT_UNLOCK (srcpad);
1549 /* fire off a signal to each of the pads telling them
1550 * that they've been unlinked */
1551 g_signal_emit (G_OBJECT (srcpad), gst_pad_signals[PAD_UNLINKED], 0, sinkpad);
1552 g_signal_emit (G_OBJECT (sinkpad), gst_pad_signals[PAD_UNLINKED], 0, srcpad);
1554 GST_CAT_INFO (GST_CAT_ELEMENT_PADS, "unlinked %s:%s and %s:%s",
1555 GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (sinkpad));
1561 g_critical ("pad %s is not a source pad", GST_PAD_NAME (srcpad));
1562 GST_OBJECT_UNLOCK (srcpad);
1567 g_critical ("pad %s is not a sink pad", GST_PAD_NAME (sinkpad));
1568 GST_OBJECT_UNLOCK (sinkpad);
1569 GST_OBJECT_UNLOCK (srcpad);
1572 not_linked_together:
1574 /* we do not emit a warning in this case because unlinking cannot
1575 * be made MT safe.*/
1576 GST_OBJECT_UNLOCK (sinkpad);
1577 GST_OBJECT_UNLOCK (srcpad);
1583 * gst_pad_is_linked:
1584 * @pad: pad to check
1586 * Checks if a @pad is linked to another pad or not.
1588 * Returns: TRUE if the pad is linked, FALSE otherwise.
1593 gst_pad_is_linked (GstPad * pad)
1597 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
1599 GST_OBJECT_LOCK (pad);
1600 result = (GST_PAD_PEER (pad) != NULL);
1601 GST_OBJECT_UNLOCK (pad);
1606 /* get the caps from both pads and see if the intersection
1609 * This function should be called with the pad LOCK on both
1613 gst_pad_link_check_compatible_unlocked (GstPad * src, GstPad * sink)
1619 srccaps = gst_pad_get_caps_unlocked (src);
1620 sinkcaps = gst_pad_get_caps_unlocked (sink);
1622 GST_CAT_DEBUG (GST_CAT_CAPS, "src caps %" GST_PTR_FORMAT, srccaps);
1623 GST_CAT_DEBUG (GST_CAT_CAPS, "sink caps %" GST_PTR_FORMAT, sinkcaps);
1625 /* if we have caps on both pads we can check the intersection. If one
1626 * of the caps is NULL, we return TRUE. */
1627 if (srccaps == NULL || sinkcaps == NULL)
1630 icaps = gst_caps_intersect (srccaps, sinkcaps);
1631 gst_caps_unref (srccaps);
1632 gst_caps_unref (sinkcaps);
1637 GST_CAT_DEBUG (GST_CAT_CAPS,
1638 "intersection caps %p %" GST_PTR_FORMAT, icaps, icaps);
1640 if (gst_caps_is_empty (icaps))
1643 gst_caps_unref (icaps);
1648 /* incompatible cases */
1651 GST_CAT_DEBUG (GST_CAT_CAPS, "intersection gave NULL");
1656 GST_CAT_DEBUG (GST_CAT_CAPS, "intersection is EMPTY");
1657 gst_caps_unref (icaps);
1662 /* check if the grandparents of both pads are the same.
1663 * This check is required so that we don't try to link
1664 * pads from elements in different bins without ghostpads.
1666 * The LOCK should be held on both pads
1669 gst_pad_link_check_hierarchy (GstPad * src, GstPad * sink)
1671 GstObject *psrc, *psink;
1673 psrc = GST_OBJECT_PARENT (src);
1674 psink = GST_OBJECT_PARENT (sink);
1676 /* if one of the pads has no parent, we allow the link */
1677 if (G_UNLIKELY (psrc == NULL || psink == NULL))
1680 /* if the parents are the same, we have a loop */
1681 if (G_UNLIKELY (psrc == psink))
1684 /* if they both have a parent, we check the grandparents. We can not lock
1685 * the parent because we hold on the child (pad) and the locking order is
1686 * parent >> child. */
1687 psrc = GST_OBJECT_PARENT (psrc);
1688 psink = GST_OBJECT_PARENT (psink);
1690 /* if they have grandparents but they are not the same */
1691 if (G_UNLIKELY (psrc != psink))
1692 goto wrong_grandparents;
1699 GST_CAT_DEBUG (GST_CAT_CAPS,
1700 "one of the pads has no parent %" GST_PTR_FORMAT " and %"
1701 GST_PTR_FORMAT, psrc, psink);
1706 GST_CAT_DEBUG (GST_CAT_CAPS, "pads have same parent %" GST_PTR_FORMAT,
1712 GST_CAT_DEBUG (GST_CAT_CAPS,
1713 "pads have different grandparents %" GST_PTR_FORMAT " and %"
1714 GST_PTR_FORMAT, psrc, psink);
1719 /* FIXME leftover from an attempt at refactoring... */
1720 /* call with the two pads unlocked, when this function returns GST_PAD_LINK_OK,
1721 * the two pads will be locked in the srcpad, sinkpad order. */
1722 static GstPadLinkReturn
1723 gst_pad_link_prepare (GstPad * srcpad, GstPad * sinkpad)
1725 /* generic checks */
1726 g_return_val_if_fail (GST_IS_PAD (srcpad), GST_PAD_LINK_REFUSED);
1727 g_return_val_if_fail (GST_IS_PAD (sinkpad), GST_PAD_LINK_REFUSED);
1729 GST_CAT_INFO (GST_CAT_PADS, "trying to link %s:%s and %s:%s",
1730 GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (sinkpad));
1732 GST_OBJECT_LOCK (srcpad);
1734 if (G_UNLIKELY (GST_PAD_DIRECTION (srcpad) != GST_PAD_SRC))
1737 if (G_UNLIKELY (GST_PAD_PEER (srcpad) != NULL))
1738 goto src_was_linked;
1740 GST_OBJECT_LOCK (sinkpad);
1742 if (G_UNLIKELY (GST_PAD_DIRECTION (sinkpad) != GST_PAD_SINK))
1745 if (G_UNLIKELY (GST_PAD_PEER (sinkpad) != NULL))
1746 goto sink_was_linked;
1748 /* check hierarchy, pads can only be linked if the grandparents
1750 if (!gst_pad_link_check_hierarchy (srcpad, sinkpad))
1751 goto wrong_hierarchy;
1753 /* check pad caps for non-empty intersection */
1754 if (!gst_pad_link_check_compatible_unlocked (srcpad, sinkpad))
1757 /* FIXME check pad scheduling for non-empty intersection */
1759 return GST_PAD_LINK_OK;
1763 g_critical ("pad %s is not a source pad", GST_PAD_NAME (srcpad));
1764 GST_OBJECT_UNLOCK (srcpad);
1765 return GST_PAD_LINK_WRONG_DIRECTION;
1769 GST_CAT_INFO (GST_CAT_PADS, "src %s:%s was already linked to %s:%s",
1770 GST_DEBUG_PAD_NAME (srcpad),
1771 GST_DEBUG_PAD_NAME (GST_PAD_PEER (srcpad)));
1772 /* we do not emit a warning in this case because unlinking cannot
1773 * be made MT safe.*/
1774 GST_OBJECT_UNLOCK (srcpad);
1775 return GST_PAD_LINK_WAS_LINKED;
1779 g_critical ("pad %s is not a sink pad", GST_PAD_NAME (sinkpad));
1780 GST_OBJECT_UNLOCK (sinkpad);
1781 GST_OBJECT_UNLOCK (srcpad);
1782 return GST_PAD_LINK_WRONG_DIRECTION;
1786 GST_CAT_INFO (GST_CAT_PADS, "sink %s:%s was already linked to %s:%s",
1787 GST_DEBUG_PAD_NAME (sinkpad),
1788 GST_DEBUG_PAD_NAME (GST_PAD_PEER (sinkpad)));
1789 /* we do not emit a warning in this case because unlinking cannot
1790 * be made MT safe.*/
1791 GST_OBJECT_UNLOCK (sinkpad);
1792 GST_OBJECT_UNLOCK (srcpad);
1793 return GST_PAD_LINK_WAS_LINKED;
1797 GST_CAT_INFO (GST_CAT_PADS, "pads have wrong hierarchy");
1798 GST_OBJECT_UNLOCK (sinkpad);
1799 GST_OBJECT_UNLOCK (srcpad);
1800 return GST_PAD_LINK_WRONG_HIERARCHY;
1804 GST_CAT_INFO (GST_CAT_PADS, "caps are incompatible");
1805 GST_OBJECT_UNLOCK (sinkpad);
1806 GST_OBJECT_UNLOCK (srcpad);
1807 return GST_PAD_LINK_NOFORMAT;
1813 * @srcpad: the source #GstPad to link.
1814 * @sinkpad: the sink #GstPad to link.
1816 * Links the source pad and the sink pad.
1818 * Returns: A result code indicating if the connection worked or
1824 gst_pad_link (GstPad * srcpad, GstPad * sinkpad)
1826 GstPadLinkReturn result;
1828 /* prepare will also lock the two pads */
1829 result = gst_pad_link_prepare (srcpad, sinkpad);
1831 if (result != GST_PAD_LINK_OK)
1832 goto prepare_failed;
1834 /* must set peers before calling the link function */
1835 GST_PAD_PEER (srcpad) = sinkpad;
1836 GST_PAD_PEER (sinkpad) = srcpad;
1838 GST_OBJECT_UNLOCK (sinkpad);
1839 GST_OBJECT_UNLOCK (srcpad);
1841 /* FIXME released the locks here, concurrent thread might link
1842 * something else. */
1843 if (GST_PAD_LINKFUNC (srcpad)) {
1844 /* this one will call the peer link function */
1845 result = GST_PAD_LINKFUNC (srcpad) (srcpad, sinkpad);
1846 } else if (GST_PAD_LINKFUNC (sinkpad)) {
1847 /* if no source link function, we need to call the sink link
1848 * function ourselves. */
1849 result = GST_PAD_LINKFUNC (sinkpad) (sinkpad, srcpad);
1851 result = GST_PAD_LINK_OK;
1854 GST_OBJECT_LOCK (srcpad);
1855 GST_OBJECT_LOCK (sinkpad);
1857 if (result == GST_PAD_LINK_OK) {
1858 GST_OBJECT_UNLOCK (sinkpad);
1859 GST_OBJECT_UNLOCK (srcpad);
1861 /* fire off a signal to each of the pads telling them
1862 * that they've been linked */
1863 g_signal_emit (G_OBJECT (srcpad), gst_pad_signals[PAD_LINKED], 0, sinkpad);
1864 g_signal_emit (G_OBJECT (sinkpad), gst_pad_signals[PAD_LINKED], 0, srcpad);
1866 GST_CAT_INFO (GST_CAT_PADS, "linked %s:%s and %s:%s, successful",
1867 GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (sinkpad));
1869 GST_CAT_INFO (GST_CAT_PADS, "link between %s:%s and %s:%s failed",
1870 GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (sinkpad));
1872 GST_PAD_PEER (srcpad) = NULL;
1873 GST_PAD_PEER (sinkpad) = NULL;
1875 GST_OBJECT_UNLOCK (sinkpad);
1876 GST_OBJECT_UNLOCK (srcpad);
1887 gst_pad_set_pad_template (GstPad * pad, GstPadTemplate * templ)
1889 GstPadTemplate **template_p;
1891 /* this function would need checks if it weren't static */
1893 GST_OBJECT_LOCK (pad);
1894 template_p = &pad->padtemplate;
1895 gst_object_replace ((GstObject **) template_p, (GstObject *) templ);
1896 GST_OBJECT_UNLOCK (pad);
1899 gst_pad_template_pad_created (templ, pad);
1903 * gst_pad_get_pad_template:
1906 * Gets the template for @pad.
1908 * Returns: the #GstPadTemplate from which this pad was instantiated, or %NULL
1909 * if this pad has no template.
1911 * FIXME: currently returns an unrefcounted padtemplate.
1914 gst_pad_get_pad_template (GstPad * pad)
1916 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
1918 return GST_PAD_PAD_TEMPLATE (pad);
1922 /* should be called with the pad LOCK held */
1923 /* refs the caps, so caller is responsible for getting it unreffed */
1925 gst_pad_get_caps_unlocked (GstPad * pad)
1927 GstCaps *result = NULL;
1929 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "get pad caps");
1931 if (GST_PAD_GETCAPSFUNC (pad)) {
1932 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
1933 "dispatching to pad getcaps function");
1935 GST_OBJECT_FLAG_SET (pad, GST_PAD_IN_GETCAPS);
1936 GST_OBJECT_UNLOCK (pad);
1937 result = GST_PAD_GETCAPSFUNC (pad) (pad);
1938 GST_OBJECT_LOCK (pad);
1939 GST_OBJECT_FLAG_UNSET (pad, GST_PAD_IN_GETCAPS);
1941 if (result == NULL) {
1942 g_critical ("pad %s:%s returned NULL caps from getcaps function",
1943 GST_DEBUG_PAD_NAME (pad));
1945 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
1946 "pad getcaps returned %" GST_PTR_FORMAT, result);
1947 #ifndef G_DISABLE_ASSERT
1948 /* check that the returned caps are a real subset of the template caps */
1949 if (GST_PAD_PAD_TEMPLATE (pad)) {
1950 const GstCaps *templ_caps =
1951 GST_PAD_TEMPLATE_CAPS (GST_PAD_PAD_TEMPLATE (pad));
1952 if (!gst_caps_is_subset (result, templ_caps)) {
1955 GST_CAT_ERROR_OBJECT (GST_CAT_CAPS, pad,
1956 "pad returned caps %" GST_PTR_FORMAT
1957 " which are not a real subset of its template caps %"
1958 GST_PTR_FORMAT, result, templ_caps);
1960 ("pad %s:%s returned caps which are not a real "
1961 "subset of its template caps", GST_DEBUG_PAD_NAME (pad));
1962 temp = gst_caps_intersect (templ_caps, result);
1963 gst_caps_unref (result);
1971 if (GST_PAD_PAD_TEMPLATE (pad)) {
1972 GstPadTemplate *templ = GST_PAD_PAD_TEMPLATE (pad);
1974 result = GST_PAD_TEMPLATE_CAPS (templ);
1975 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
1976 "using pad template %p with caps %p %" GST_PTR_FORMAT, templ, result,
1979 result = gst_caps_ref (result);
1982 if (GST_PAD_CAPS (pad)) {
1983 result = GST_PAD_CAPS (pad);
1985 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
1986 "using pad caps %p %" GST_PTR_FORMAT, result, result);
1988 result = gst_caps_ref (result);
1992 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "pad has no caps");
1993 result = gst_caps_new_empty ();
2001 * @pad: a #GstPad to get the capabilities of.
2003 * Gets the capabilities this pad can produce or consume.
2004 * Note that this method doesn't necessarily return the caps set by
2005 * gst_pad_set_caps() - use #GST_PAD_CAPS for that instead.
2006 * gst_pad_get_caps returns all possible caps a pad can operate with, using
2007 * the pad's get_caps function;
2008 * this returns the pad template caps if not explicitly set.
2010 * Returns: a newly allocated copy of the #GstCaps of this pad.
2015 gst_pad_get_caps (GstPad * pad)
2017 GstCaps *result = NULL;
2019 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2021 GST_OBJECT_LOCK (pad);
2023 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "get pad caps");
2025 result = gst_pad_get_caps_unlocked (pad);
2026 GST_OBJECT_UNLOCK (pad);
2032 * gst_pad_peer_get_caps:
2033 * @pad: a #GstPad to get the peer capabilities of.
2035 * Gets the capabilities of the peer connected to this pad.
2037 * Returns: the #GstCaps of the peer pad. This function returns a new caps, so use
2038 * gst_caps_unref to get rid of it. this function returns NULL if there is no
2042 gst_pad_peer_get_caps (GstPad * pad)
2045 GstCaps *result = NULL;
2047 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2049 GST_OBJECT_LOCK (pad);
2051 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "get peer caps");
2053 peerpad = GST_PAD_PEER (pad);
2054 if (G_UNLIKELY (peerpad == NULL))
2057 gst_object_ref (peerpad);
2058 GST_OBJECT_UNLOCK (pad);
2060 result = gst_pad_get_caps (peerpad);
2062 gst_object_unref (peerpad);
2068 GST_OBJECT_UNLOCK (pad);
2074 fixate_value (GValue * dest, const GValue * src)
2076 if (G_VALUE_TYPE (src) == GST_TYPE_INT_RANGE) {
2077 g_value_init (dest, G_TYPE_INT);
2078 g_value_set_int (dest, gst_value_get_int_range_min (src));
2079 } else if (G_VALUE_TYPE (src) == GST_TYPE_DOUBLE_RANGE) {
2080 g_value_init (dest, G_TYPE_DOUBLE);
2081 g_value_set_double (dest, gst_value_get_double_range_min (src));
2082 } else if (G_VALUE_TYPE (src) == GST_TYPE_FRACTION_RANGE) {
2083 gst_value_init_and_copy (dest, gst_value_get_fraction_range_min (src));
2084 } else if (G_VALUE_TYPE (src) == GST_TYPE_LIST) {
2085 GValue temp = { 0 };
2087 gst_value_init_and_copy (&temp, gst_value_list_get_value (src, 0));
2088 if (!fixate_value (dest, &temp))
2089 gst_value_init_and_copy (dest, &temp);
2090 g_value_unset (&temp);
2091 } else if (G_VALUE_TYPE (src) == GST_TYPE_ARRAY) {
2092 gboolean res = FALSE;
2095 g_value_init (dest, GST_TYPE_ARRAY);
2096 for (n = 0; n < gst_value_array_get_size (src); n++) {
2098 const GValue *orig_kid = gst_value_array_get_value (src, n);
2100 if (!fixate_value (&kid, orig_kid))
2101 gst_value_init_and_copy (&kid, orig_kid);
2104 gst_value_array_append_value (dest, &kid);
2105 g_value_unset (&kid);
2109 g_value_unset (dest);
2120 gst_pad_default_fixate (GQuark field_id, const GValue * value, gpointer data)
2122 GstStructure *s = data;
2125 if (fixate_value (&v, value)) {
2126 gst_structure_id_set_value (s, field_id, &v);
2134 * gst_pad_fixate_caps:
2135 * @pad: a #GstPad to fixate
2136 * @caps: the #GstCaps to fixate
2138 * Fixate a caps on the given pad. Modifies the caps in place, so you should
2139 * make sure that the caps are actually writable (see gst_caps_make_writable()).
2142 gst_pad_fixate_caps (GstPad * pad, GstCaps * caps)
2144 GstPadFixateCapsFunction fixatefunc;
2147 g_return_if_fail (GST_IS_PAD (pad));
2148 g_return_if_fail (caps != NULL);
2150 if (gst_caps_is_fixed (caps))
2153 fixatefunc = GST_PAD_FIXATECAPSFUNC (pad);
2155 fixatefunc (pad, caps);
2158 /* default fixation */
2159 for (n = 0; n < gst_caps_get_size (caps); n++) {
2160 GstStructure *s = gst_caps_get_structure (caps, n);
2162 gst_structure_foreach (s, gst_pad_default_fixate, s);
2166 /* Default accept caps implementation just checks against
2167 * against the allowed caps for the pad */
2169 gst_pad_acceptcaps_default (GstPad * pad, GstCaps * caps)
2171 /* get the caps and see if it intersects to something
2175 gboolean result = FALSE;
2177 allowed = gst_pad_get_caps (pad);
2179 goto nothing_allowed;
2181 intersect = gst_caps_intersect (allowed, caps);
2183 result = !gst_caps_is_empty (intersect);
2185 GST_DEBUG_OBJECT (pad, "intersection gave empty caps");
2187 gst_caps_unref (allowed);
2188 gst_caps_unref (intersect);
2195 GST_DEBUG_OBJECT (pad, "no caps allowed on the pad");
2201 * gst_pad_accept_caps:
2202 * @pad: a #GstPad to check
2203 * @caps: a #GstCaps to check on the pad
2205 * Check if the given pad accepts the caps.
2207 * Returns: TRUE if the pad can accept the caps.
2210 gst_pad_accept_caps (GstPad * pad, GstCaps * caps)
2213 GstPadAcceptCapsFunction acceptfunc;
2214 GstCaps *existing = NULL;
2216 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2218 /* any pad can be unnegotiated */
2222 /* lock for checking the existing caps */
2223 GST_OBJECT_LOCK (pad);
2224 acceptfunc = GST_PAD_ACCEPTCAPSFUNC (pad);
2225 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "accept caps of %p", caps);
2226 /* The current caps on a pad are trivially acceptable */
2227 if (G_LIKELY ((existing = GST_PAD_CAPS (pad)))) {
2228 if (caps == existing || gst_caps_is_equal (caps, existing))
2231 GST_OBJECT_UNLOCK (pad);
2233 if (G_LIKELY (acceptfunc)) {
2234 /* we can call the function */
2235 result = acceptfunc (pad, caps);
2236 GST_DEBUG_OBJECT (pad, "acceptfunc returned %d", result);
2238 /* Only null if the element explicitly unset it */
2239 result = gst_pad_acceptcaps_default (pad, caps);
2240 GST_DEBUG_OBJECT (pad, "default acceptcaps returned %d", result);
2246 GST_DEBUG_OBJECT (pad, "pad had same caps");
2247 GST_OBJECT_UNLOCK (pad);
2253 * gst_pad_peer_accept_caps:
2254 * @pad: a #GstPad to check the peer of
2255 * @caps: a #GstCaps to check on the pad
2257 * Check if the peer of @pad accepts @caps. If @pad has no peer, this function
2260 * Returns: TRUE if the peer of @pad can accept the caps or @pad has no peer.
2263 gst_pad_peer_accept_caps (GstPad * pad, GstCaps * caps)
2268 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2270 GST_OBJECT_LOCK (pad);
2272 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "peer accept caps of (%p)", pad);
2274 peerpad = GST_PAD_PEER (pad);
2275 if (G_UNLIKELY (peerpad == NULL))
2278 result = gst_pad_accept_caps (peerpad, caps);
2279 GST_OBJECT_UNLOCK (pad);
2285 GST_OBJECT_UNLOCK (pad);
2292 * @pad: a #GstPad to set the capabilities of.
2293 * @caps: a #GstCaps to set.
2295 * Sets the capabilities of this pad. The caps must be fixed. Any previous
2296 * caps on the pad will be unreffed. This function refs the caps so you should
2297 * unref if as soon as you don't need it anymore.
2298 * It is possible to set NULL caps, which will make the pad unnegotiated
2301 * Returns: TRUE if the caps could be set. FALSE if the caps were not fixed
2302 * or bad parameters were provided to this function.
2307 gst_pad_set_caps (GstPad * pad, GstCaps * caps)
2309 GstPadSetCapsFunction setcaps;
2312 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2313 g_return_val_if_fail (caps == NULL || gst_caps_is_fixed (caps), FALSE);
2315 GST_OBJECT_LOCK (pad);
2316 existing = GST_PAD_CAPS (pad);
2317 if (existing == caps)
2320 if (gst_caps_is_equal (caps, existing))
2321 goto setting_same_caps;
2323 setcaps = GST_PAD_SETCAPSFUNC (pad);
2325 /* call setcaps function to configure the pad only if the
2326 * caps is not NULL */
2327 if (setcaps != NULL && caps) {
2328 if (!GST_PAD_IS_IN_SETCAPS (pad)) {
2329 GST_OBJECT_FLAG_SET (pad, GST_PAD_IN_SETCAPS);
2330 GST_OBJECT_UNLOCK (pad);
2331 if (!setcaps (pad, caps))
2333 GST_OBJECT_LOCK (pad);
2334 GST_OBJECT_FLAG_UNSET (pad, GST_PAD_IN_SETCAPS);
2336 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "pad was dispatching");
2340 gst_caps_replace (&GST_PAD_CAPS (pad), caps);
2341 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "caps %" GST_PTR_FORMAT, caps);
2342 GST_OBJECT_UNLOCK (pad);
2344 g_object_notify (G_OBJECT (pad), "caps");
2350 GST_OBJECT_UNLOCK (pad);
2355 gst_caps_replace (&GST_PAD_CAPS (pad), caps);
2356 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
2357 "caps %" GST_PTR_FORMAT " same as existing, updating ptr only", caps);
2358 GST_OBJECT_UNLOCK (pad);
2365 GST_OBJECT_LOCK (pad);
2366 GST_OBJECT_FLAG_UNSET (pad, GST_PAD_IN_SETCAPS);
2367 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
2368 "caps %" GST_PTR_FORMAT " could not be set", caps);
2369 GST_OBJECT_UNLOCK (pad);
2376 gst_pad_configure_sink (GstPad * pad, GstCaps * caps)
2378 GstPadSetCapsFunction setcaps;
2381 setcaps = GST_PAD_SETCAPSFUNC (pad);
2383 /* See if pad accepts the caps - only needed if
2384 * no setcaps function */
2385 if (setcaps == NULL)
2386 if (!gst_pad_accept_caps (pad, caps))
2389 /* set caps on pad if call succeeds */
2390 res = gst_pad_set_caps (pad, caps);
2391 /* no need to unref the caps here, set_caps takes a ref and
2392 * our ref goes away when we leave this function. */
2398 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
2399 "caps %" GST_PTR_FORMAT " not accepted", caps);
2404 /* returns TRUE if the src pad could be configured to accept the given caps */
2406 gst_pad_configure_src (GstPad * pad, GstCaps * caps, gboolean dosetcaps)
2408 GstPadSetCapsFunction setcaps;
2411 setcaps = GST_PAD_SETCAPSFUNC (pad);
2413 /* See if pad accepts the caps - only needed if
2414 * no setcaps function */
2415 if (setcaps == NULL)
2416 if (!gst_pad_accept_caps (pad, caps))
2420 res = gst_pad_set_caps (pad, caps);
2428 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
2429 "caps %" GST_PTR_FORMAT " not accepted", caps);
2435 * gst_pad_get_pad_template_caps:
2436 * @pad: a #GstPad to get the template capabilities from.
2438 * Gets the capabilities for @pad's template.
2440 * Returns: the #GstCaps of this pad template. If you intend to keep a reference
2441 * on the caps, make a copy (see gst_caps_copy ()).
2444 gst_pad_get_pad_template_caps (GstPad * pad)
2446 static GstStaticCaps anycaps = GST_STATIC_CAPS ("ANY");
2448 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2450 if (GST_PAD_PAD_TEMPLATE (pad))
2451 return GST_PAD_TEMPLATE_CAPS (GST_PAD_PAD_TEMPLATE (pad));
2453 return gst_static_caps_get (&anycaps);
2459 * @pad: a #GstPad to get the peer of.
2461 * Gets the peer of @pad. This function refs the peer pad so
2462 * you need to unref it after use.
2464 * Returns: the peer #GstPad. Unref after usage.
2469 gst_pad_get_peer (GstPad * pad)
2473 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2475 GST_OBJECT_LOCK (pad);
2476 result = GST_PAD_PEER (pad);
2478 gst_object_ref (result);
2479 GST_OBJECT_UNLOCK (pad);
2485 * gst_pad_get_allowed_caps:
2488 * Gets the capabilities of the allowed media types that can flow through
2489 * @pad and its peer.
2491 * The allowed capabilities is calculated as the intersection of the results of
2492 * calling gst_pad_get_caps() on @pad and its peer. The caller owns a reference
2493 * on the resulting caps.
2495 * Returns: the allowed #GstCaps of the pad link. Unref the caps when you no
2496 * longer need it. This function returns NULL when @pad has no peer.
2501 gst_pad_get_allowed_caps (GstPad * pad)
2508 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2510 GST_OBJECT_LOCK (pad);
2512 peer = GST_PAD_PEER (pad);
2513 if (G_UNLIKELY (peer == NULL))
2516 GST_CAT_DEBUG_OBJECT (GST_CAT_PROPERTIES, pad, "getting allowed caps");
2518 gst_object_ref (peer);
2519 GST_OBJECT_UNLOCK (pad);
2520 mycaps = gst_pad_get_caps (pad);
2522 peercaps = gst_pad_get_caps (peer);
2523 gst_object_unref (peer);
2525 caps = gst_caps_intersect (mycaps, peercaps);
2526 gst_caps_unref (peercaps);
2527 gst_caps_unref (mycaps);
2529 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "allowed caps %" GST_PTR_FORMAT,
2536 GST_CAT_DEBUG_OBJECT (GST_CAT_PROPERTIES, pad, "no peer");
2537 GST_OBJECT_UNLOCK (pad);
2544 * gst_pad_get_negotiated_caps:
2547 * Gets the capabilities of the media type that currently flows through @pad
2550 * This function can be used on both src and sinkpads. Note that srcpads are
2551 * always negotiated before sinkpads so it is possible that the negotiated caps
2552 * on the srcpad do not match the negotiated caps of the peer.
2554 * Returns: the negotiated #GstCaps of the pad link. Free the caps when
2555 * you no longer need it. This function returns NULL when the @pad has no
2556 * peer or is not negotiated yet.
2561 gst_pad_get_negotiated_caps (GstPad * pad)
2566 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2568 GST_OBJECT_LOCK (pad);
2570 if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
2573 GST_CAT_DEBUG_OBJECT (GST_CAT_PROPERTIES, pad, "getting negotiated caps");
2575 caps = GST_PAD_CAPS (pad);
2577 gst_caps_ref (caps);
2578 GST_OBJECT_UNLOCK (pad);
2580 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "negotiated caps %" GST_PTR_FORMAT,
2587 GST_CAT_DEBUG_OBJECT (GST_CAT_PROPERTIES, pad, "no peer");
2588 GST_OBJECT_UNLOCK (pad);
2594 /* calls the buffer_alloc function on the given pad */
2595 static GstFlowReturn
2596 gst_pad_buffer_alloc_unchecked (GstPad * pad, guint64 offset, gint size,
2597 GstCaps * caps, GstBuffer ** buf)
2600 GstPadBufferAllocFunction bufferallocfunc;
2602 GST_OBJECT_LOCK (pad);
2603 /* when the pad is flushing we cannot give a buffer */
2604 if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad)))
2607 bufferallocfunc = pad->bufferallocfunc;
2609 if (offset == GST_BUFFER_OFFSET_NONE) {
2610 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
2611 "calling bufferallocfunc &%s (@%p) for size %d offset NONE",
2612 GST_DEBUG_FUNCPTR_NAME (bufferallocfunc), bufferallocfunc, size);
2614 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
2615 "calling bufferallocfunc &%s (@%p) of for size %d offset %"
2616 G_GUINT64_FORMAT, GST_DEBUG_FUNCPTR_NAME (bufferallocfunc),
2617 bufferallocfunc, size, offset);
2619 GST_OBJECT_UNLOCK (pad);
2621 /* G_LIKELY for now since most elements don't implement a buffer alloc
2622 * function and there is no default alloc proxy function as this is usually
2624 if (G_LIKELY (bufferallocfunc == NULL))
2627 ret = bufferallocfunc (pad, offset, size, caps, buf);
2628 if (G_UNLIKELY (ret != GST_FLOW_OK))
2630 /* no error, but NULL buffer means fallback to the default */
2631 if (G_UNLIKELY (*buf == NULL))
2634 /* If the buffer alloc function didn't set up the caps like it should,
2636 if (G_UNLIKELY (caps && (GST_BUFFER_CAPS (*buf) == NULL))) {
2637 GST_WARNING_OBJECT (pad,
2638 "Buffer allocation function did not set caps. Setting");
2639 gst_buffer_set_caps (*buf, caps);
2645 /* pad was flushing */
2646 GST_OBJECT_UNLOCK (pad);
2647 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "pad was flushing");
2648 return GST_FLOW_WRONG_STATE;
2652 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
2653 "alloc function returned error (%d) %s", ret, gst_flow_get_name (ret));
2658 /* fallback case, allocate a buffer of our own, add pad caps. */
2659 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "fallback buffer alloc");
2661 *buf = gst_buffer_new_and_alloc (size);
2662 GST_BUFFER_OFFSET (*buf) = offset;
2663 gst_buffer_set_caps (*buf, caps);
2669 static GstFlowReturn
2670 gst_pad_alloc_buffer_full (GstPad * pad, guint64 offset, gint size,
2671 GstCaps * caps, GstBuffer ** buf, gboolean setcaps)
2675 gboolean caps_changed;
2677 g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
2678 g_return_val_if_fail (GST_PAD_IS_SRC (pad), GST_FLOW_ERROR);
2679 g_return_val_if_fail (buf != NULL, GST_FLOW_ERROR);
2681 GST_OBJECT_LOCK (pad);
2682 while (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad)))
2683 if ((ret = handle_pad_block (pad)) != GST_FLOW_OK)
2686 if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
2689 gst_object_ref (peer);
2690 GST_OBJECT_UNLOCK (pad);
2692 ret = gst_pad_buffer_alloc_unchecked (peer, offset, size, caps, buf);
2693 gst_object_unref (peer);
2695 if (G_UNLIKELY (ret != GST_FLOW_OK))
2698 /* FIXME, move capnego this into a base class? */
2699 caps = GST_BUFFER_CAPS (*buf);
2701 /* Lock for checking caps, pretty pointless as the _pad_push() function might
2702 * change it concurrently, one of the problems with automatic caps setting in
2703 * pad_alloc_and_set_caps. Worst case, if does a check too much, but only when
2704 * there is heavy renegotiation going on in both directions. */
2705 GST_OBJECT_LOCK (pad);
2706 caps_changed = caps && caps != GST_PAD_CAPS (pad);
2707 GST_OBJECT_UNLOCK (pad);
2709 /* we got a new datatype on the pad, see if it can handle it */
2710 if (G_UNLIKELY (caps_changed)) {
2711 GST_DEBUG_OBJECT (pad, "caps changed to %p %" GST_PTR_FORMAT, caps, caps);
2712 if (G_UNLIKELY (!gst_pad_configure_src (pad, caps, setcaps)))
2713 goto not_negotiated;
2719 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "pad block stopped by flush");
2720 GST_OBJECT_UNLOCK (pad);
2725 /* pad has no peer */
2726 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
2727 "called bufferallocfunc but had no peer");
2728 GST_OBJECT_UNLOCK (pad);
2729 return GST_FLOW_NOT_LINKED;
2733 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
2734 "alloc function returned error %s", gst_flow_get_name (ret));
2739 gst_buffer_unref (*buf);
2741 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
2742 "alloc function returned unacceptable buffer");
2743 return GST_FLOW_NOT_NEGOTIATED;
2748 * gst_pad_alloc_buffer:
2749 * @pad: a source #GstPad
2750 * @offset: the offset of the new buffer in the stream
2751 * @size: the size of the new buffer
2752 * @caps: the caps of the new buffer
2753 * @buf: a newly allocated buffer
2755 * Allocates a new, empty buffer optimized to push to pad @pad. This
2756 * function only works if @pad is a source pad and has a peer.
2758 * A new, empty #GstBuffer will be put in the @buf argument.
2759 * You need to check the caps of the buffer after performing this
2760 * function and renegotiate to the format if needed.
2762 * Returns: a result code indicating success of the operation. Any
2763 * result code other than #GST_FLOW_OK is an error and @buf should
2765 * An error can occur if the pad is not connected or when the downstream
2766 * peer elements cannot provide an acceptable buffer.
2771 gst_pad_alloc_buffer (GstPad * pad, guint64 offset, gint size, GstCaps * caps,
2774 return gst_pad_alloc_buffer_full (pad, offset, size, caps, buf, FALSE);
2778 * gst_pad_alloc_buffer_and_set_caps:
2779 * @pad: a source #GstPad
2780 * @offset: the offset of the new buffer in the stream
2781 * @size: the size of the new buffer
2782 * @caps: the caps of the new buffer
2783 * @buf: a newly allocated buffer
2785 * In addition to the function gst_pad_alloc_buffer(), this function
2786 * automatically calls gst_pad_set_caps() when the caps of the
2787 * newly allocated buffer are different from the @pad caps.
2789 * Returns: a result code indicating success of the operation. Any
2790 * result code other than #GST_FLOW_OK is an error and @buf should
2792 * An error can occur if the pad is not connected or when the downstream
2793 * peer elements cannot provide an acceptable buffer.
2798 gst_pad_alloc_buffer_and_set_caps (GstPad * pad, guint64 offset, gint size,
2799 GstCaps * caps, GstBuffer ** buf)
2801 return gst_pad_alloc_buffer_full (pad, offset, size, caps, buf, TRUE);
2805 * gst_pad_get_internal_links_default:
2806 * @pad: the #GstPad to get the internal links of.
2808 * Gets a list of pads to which the given pad is linked to
2809 * inside of the parent element.
2810 * This is the default handler, and thus returns a list of all of the
2811 * pads inside the parent element with opposite direction.
2812 * The caller must free this list after use.
2814 * Returns: a newly allocated #GList of pads, or NULL if the pad has no parent.
2819 gst_pad_get_internal_links_default (GstPad * pad)
2824 GstPadDirection direction;
2826 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2828 direction = pad->direction;
2830 parent = GST_PAD_PARENT (pad);
2834 parent_pads = parent->pads;
2836 while (parent_pads) {
2837 GstPad *parent_pad = GST_PAD_CAST (parent_pads->data);
2839 if (parent_pad->direction != direction) {
2840 res = g_list_prepend (res, parent_pad);
2843 parent_pads = g_list_next (parent_pads);
2850 * gst_pad_get_internal_links:
2851 * @pad: the #GstPad to get the internal links of.
2853 * Gets a list of pads to which the given pad is linked to
2854 * inside of the parent element.
2855 * The caller must free this list after use.
2857 * Returns: a newly allocated #GList of pads.
2862 gst_pad_get_internal_links (GstPad * pad)
2866 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2868 if (GST_PAD_INTLINKFUNC (pad))
2869 res = GST_PAD_INTLINKFUNC (pad) (pad);
2876 gst_pad_event_default_dispatch (GstPad * pad, GstEvent * event)
2881 GST_INFO_OBJECT (pad, "Sending event %p (%s) to all internally linked pads",
2882 event, GST_EVENT_TYPE_NAME (event));
2884 result = (GST_PAD_DIRECTION (pad) == GST_PAD_SINK);
2886 orig = pads = gst_pad_get_internal_links (pad);
2889 GstPad *eventpad = GST_PAD_CAST (pads->data);
2891 pads = g_list_next (pads);
2893 if (GST_PAD_DIRECTION (eventpad) == GST_PAD_SRC) {
2894 /* for each pad we send to, we should ref the event; it's up
2895 * to downstream to unref again when handled. */
2896 GST_LOG_OBJECT (pad, "Reffing and sending event %p (%s) to %s:%s",
2897 event, GST_EVENT_TYPE_NAME (event), GST_DEBUG_PAD_NAME (eventpad));
2898 gst_event_ref (event);
2899 gst_pad_push_event (eventpad, event);
2901 /* we only send the event on one pad, multi-sinkpad elements
2902 * should implement a handler */
2903 GST_LOG_OBJECT (pad, "sending event %p (%s) to one sink pad %s:%s",
2904 event, GST_EVENT_TYPE_NAME (event), GST_DEBUG_PAD_NAME (eventpad));
2905 result = gst_pad_push_event (eventpad, event);
2909 /* we handled the incoming event so we unref once */
2910 GST_LOG_OBJECT (pad, "handled event %p, unreffing", event);
2911 gst_event_unref (event);
2920 * gst_pad_event_default:
2921 * @pad: a #GstPad to call the default event handler on.
2922 * @event: the #GstEvent to handle.
2924 * Invokes the default event handler for the given pad. End-of-stream and
2925 * discontinuity events are handled specially, and then the event is sent to all
2926 * pads internally linked to @pad. Note that if there are many possible sink
2927 * pads that are internally linked to @pad, only one will be sent an event.
2928 * Multi-sinkpad elements should implement custom event handlers.
2930 * Returns: TRUE if the event was sent succesfully.
2933 gst_pad_event_default (GstPad * pad, GstEvent * event)
2935 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2936 g_return_val_if_fail (event != NULL, FALSE);
2938 switch (GST_EVENT_TYPE (event)) {
2941 GST_DEBUG_OBJECT (pad, "pausing task because of eos");
2942 gst_pad_pause_task (pad);
2949 return gst_pad_event_default_dispatch (pad, event);
2953 * gst_pad_dispatcher:
2954 * @pad: a #GstPad to dispatch.
2955 * @dispatch: the #GstDispatcherFunction to call.
2956 * @data: gpointer user data passed to the dispatcher function.
2958 * Invokes the given dispatcher function on each respective peer of
2959 * all pads that are internally linked to the given pad.
2960 * The GstPadDispatcherFunction should return TRUE when no further pads
2961 * need to be processed.
2963 * Returns: TRUE if one of the dispatcher functions returned TRUE.
2966 gst_pad_dispatcher (GstPad * pad, GstPadDispatcherFunction dispatch,
2969 gboolean res = FALSE;
2970 GList *int_pads, *orig;
2972 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2973 g_return_val_if_fail (dispatch != NULL, FALSE);
2975 orig = int_pads = gst_pad_get_internal_links (pad);
2978 GstPad *int_pad = GST_PAD_CAST (int_pads->data);
2979 GstPad *int_peer = GST_PAD_PEER (int_pad);
2982 res = dispatch (int_peer, data);
2986 int_pads = g_list_next (int_pads);
2996 * @pad: a #GstPad to invoke the default query on.
2997 * @query: the #GstQuery to perform.
2999 * Dispatches a query to a pad. The query should have been allocated by the
3000 * caller via one of the type-specific allocation functions in gstquery.h. The
3001 * element is responsible for filling the query with an appropriate response,
3002 * which should then be parsed with a type-specific query parsing function.
3004 * Again, the caller is responsible for both the allocation and deallocation of
3005 * the query structure.
3007 * Returns: TRUE if the query could be performed.
3010 gst_pad_query (GstPad * pad, GstQuery * query)
3012 GstPadQueryFunction func;
3014 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
3015 g_return_val_if_fail (GST_IS_QUERY (query), FALSE);
3017 GST_DEBUG_OBJECT (pad, "sending query %p", query);
3019 if ((func = GST_PAD_QUERYFUNC (pad)) == NULL)
3022 return func (pad, query);
3026 GST_DEBUG_OBJECT (pad, "had no query function");
3032 * gst_pad_query_default:
3033 * @pad: a #GstPad to call the default query handler on.
3034 * @query: the #GstQuery to handle.
3036 * Invokes the default query handler for the given pad.
3037 * The query is sent to all pads internally linked to @pad. Note that
3038 * if there are many possible sink pads that are internally linked to
3039 * @pad, only one will be sent the query.
3040 * Multi-sinkpad elements should implement custom query handlers.
3042 * Returns: TRUE if the query was performed succesfully.
3045 gst_pad_query_default (GstPad * pad, GstQuery * query)
3047 switch (GST_QUERY_TYPE (query)) {
3048 case GST_QUERY_POSITION:
3049 case GST_QUERY_SEEKING:
3050 case GST_QUERY_FORMATS:
3051 case GST_QUERY_LATENCY:
3052 case GST_QUERY_JITTER:
3053 case GST_QUERY_RATE:
3054 case GST_QUERY_CONVERT:
3056 return gst_pad_dispatcher
3057 (pad, (GstPadDispatcherFunction) gst_pad_query, query);
3061 #ifndef GST_DISABLE_LOADSAVE
3062 /* FIXME: why isn't this on a GstElement ? */
3064 * gst_pad_load_and_link:
3065 * @self: an #xmlNodePtr to read the description from.
3066 * @parent: the #GstObject element that owns the pad.
3068 * Reads the pad definition from the XML node and links the given pad
3069 * in the element to a pad of an element up in the hierarchy.
3072 gst_pad_load_and_link (xmlNodePtr self, GstObject * parent)
3074 xmlNodePtr field = self->xmlChildrenNode;
3075 GstPad *pad = NULL, *targetpad;
3079 GstObject *grandparent;
3083 if (!strcmp ((char *) field->name, "name")) {
3084 name = (gchar *) xmlNodeGetContent (field);
3085 pad = gst_element_get_pad (GST_ELEMENT (parent), name);
3087 } else if (!strcmp ((char *) field->name, "peer")) {
3088 peer = (gchar *) xmlNodeGetContent (field);
3090 field = field->next;
3092 g_return_if_fail (pad != NULL);
3097 split = g_strsplit (peer, ".", 2);
3099 if (split[0] == NULL || split[1] == NULL) {
3100 GST_CAT_DEBUG_OBJECT (GST_CAT_XML, pad,
3101 "Could not parse peer '%s', leaving unlinked", peer);
3108 g_return_if_fail (split[0] != NULL);
3109 g_return_if_fail (split[1] != NULL);
3111 grandparent = gst_object_get_parent (parent);
3113 if (grandparent && GST_IS_BIN (grandparent)) {
3114 target = gst_bin_get_by_name_recurse_up (GST_BIN (grandparent), split[0]);
3121 targetpad = gst_element_get_pad (target, split[1]);
3123 if (targetpad == NULL)
3126 gst_pad_link (pad, targetpad);
3133 * gst_pad_save_thyself:
3134 * @pad: a #GstPad to save.
3135 * @parent: the parent #xmlNodePtr to save the description in.
3137 * Saves the pad into an xml representation.
3139 * Returns: the #xmlNodePtr representation of the pad.
3142 gst_pad_save_thyself (GstObject * object, xmlNodePtr parent)
3147 g_return_val_if_fail (GST_IS_PAD (object), NULL);
3149 pad = GST_PAD (object);
3151 xmlNewChild (parent, NULL, (xmlChar *) "name",
3152 (xmlChar *) GST_PAD_NAME (pad));
3154 if (GST_PAD_IS_SRC (pad)) {
3155 xmlNewChild (parent, NULL, (xmlChar *) "direction", (xmlChar *) "source");
3156 } else if (GST_PAD_IS_SINK (pad)) {
3157 xmlNewChild (parent, NULL, (xmlChar *) "direction", (xmlChar *) "sink");
3159 xmlNewChild (parent, NULL, (xmlChar *) "direction", (xmlChar *) "unknown");
3162 if (GST_PAD_PEER (pad) != NULL) {
3165 peer = GST_PAD_PEER (pad);
3166 /* first check to see if the peer's parent's parent is the same */
3167 /* we just save it off */
3168 content = g_strdup_printf ("%s.%s",
3169 GST_OBJECT_NAME (GST_PAD_PARENT (peer)), GST_PAD_NAME (peer));
3170 xmlNewChild (parent, NULL, (xmlChar *) "peer", (xmlChar *) content);
3173 xmlNewChild (parent, NULL, (xmlChar *) "peer", NULL);
3180 * gst_ghost_pad_save_thyself:
3181 * @pad: a ghost #GstPad to save.
3182 * @parent: the parent #xmlNodePtr to save the description in.
3184 * Saves the ghost pad into an xml representation.
3186 * Returns: the #xmlNodePtr representation of the pad.
3189 gst_ghost_pad_save_thyself (GstPad * pad, xmlNodePtr parent)
3193 g_return_val_if_fail (GST_IS_GHOST_PAD (pad), NULL);
3195 self = xmlNewChild (parent, NULL, (xmlChar *) "ghostpad", NULL);
3196 xmlNewChild (self, NULL, (xmlChar *) "name", (xmlChar *) GST_PAD_NAME (pad));
3197 xmlNewChild (self, NULL, (xmlChar *) "parent",
3198 (xmlChar *) GST_OBJECT_NAME (GST_PAD_PARENT (pad)));
3200 /* FIXME FIXME FIXME! */
3205 #endif /* GST_DISABLE_LOADSAVE */
3208 * should be called with pad OBJECT_LOCK and STREAM_LOCK held.
3209 * GST_PAD_IS_BLOCKED (pad) == TRUE when this function is
3212 * This function perform the pad blocking when an event, buffer push
3213 * or buffer_alloc is performed on a _SRC_ pad. It blocks the
3214 * streaming thread after informing the pad has been blocked.
3216 * An application can with this method wait and block any streaming
3217 * thread and perform operations such as seeking or linking.
3219 * Two methods are available for notifying the application of the
3221 * - the callback method, which happens in the STREAMING thread with
3222 * the STREAM_LOCK held. With this method, the most usefull way of
3223 * dealing with the callback is to post a message to the main thread
3224 * where the pad block can then be handled outside of the streaming
3225 * thread. With the last method one can perform all operations such
3226 * as doing a state change, linking, unblocking, seeking etc on the
3228 * - the GCond signal method, which makes any thread unblock when
3229 * the pad block happens.
3231 * During the actual blocking state, the GST_PAD_BLOCKING flag is set.
3232 * The GST_PAD_BLOCKING flag is unset when the pad was unblocked.
3236 static GstFlowReturn
3237 handle_pad_block (GstPad * pad)
3239 GstPadBlockCallback callback;
3241 GstFlowReturn ret = GST_FLOW_OK;
3243 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "signal block taken");
3245 /* flushing, don't bother trying to block and return WRONG_STATE
3247 if (GST_PAD_IS_FLUSHING (pad))
3248 goto flushingnonref;
3250 /* we grab an extra ref for the callbacks, this is probably not
3251 * needed (callback code does not have a ref and cannot unref). I
3252 * think this was done to make it possible to unref the element in
3253 * the callback, which is in the end totally impossible as it
3254 * requires grabbing the STREAM_LOCK and OBJECT_LOCK which are
3255 * all taken when calling this function. */
3256 gst_object_ref (pad);
3258 /* we either have a callback installed to notify the block or
3259 * some other thread is doing a GCond wait. */
3260 callback = pad->block_callback;
3262 /* there is a callback installed, call it. We release the
3263 * lock so that the callback can do something usefull with the
3265 user_data = pad->block_data;
3266 GST_OBJECT_UNLOCK (pad);
3267 callback (pad, TRUE, user_data);
3268 GST_OBJECT_LOCK (pad);
3270 /* we released the lock, recheck flushing */
3271 if (GST_PAD_IS_FLUSHING (pad))
3274 /* no callback, signal the thread that is doing a GCond wait
3276 GST_PAD_BLOCK_BROADCAST (pad);
3279 /* OBJECT_LOCK could have been released when we did the callback, which
3280 * then could have made the pad unblock so we need to check the blocking
3281 * condition again. */
3282 while (GST_PAD_IS_BLOCKED (pad)) {
3283 /* now we block the streaming thread. It can be unlocked when we
3284 * deactivate the pad (which will also set the FLUSHING flag) or
3285 * when the pad is unblocked. A flushing event will also unblock
3286 * the pad after setting the FLUSHING flag. */
3287 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3288 "Waiting to be unblocked or set flushing");
3289 GST_OBJECT_FLAG_SET (pad, GST_PAD_BLOCKING);
3290 GST_PAD_BLOCK_WAIT (pad);
3291 GST_OBJECT_FLAG_UNSET (pad, GST_PAD_BLOCKING);
3293 /* see if we got unblocked by a flush or not */
3294 if (GST_PAD_IS_FLUSHING (pad))
3298 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "got unblocked");
3300 /* when we get here, the pad is unblocked again and we perform
3301 * the needed unblock code. */
3302 callback = pad->block_callback;
3304 /* we need to call the callback */
3305 user_data = pad->block_data;
3306 GST_OBJECT_UNLOCK (pad);
3307 callback (pad, FALSE, user_data);
3308 GST_OBJECT_LOCK (pad);
3310 /* we need to signal the thread waiting on the GCond */
3311 GST_PAD_BLOCK_BROADCAST (pad);
3314 gst_object_unref (pad);
3320 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "pad was flushing");
3321 return GST_FLOW_WRONG_STATE;
3325 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "pad became flushing");
3326 gst_object_unref (pad);
3327 return GST_FLOW_WRONG_STATE;
3331 /**********************************************************************
3332 * Data passing functions
3336 gst_pad_emit_have_data_signal (GstPad * pad, GstMiniObject * obj)
3339 GValue args[2] = { {0}, {0} };
3344 g_value_init (&ret, G_TYPE_BOOLEAN);
3345 g_value_set_boolean (&ret, TRUE);
3346 g_value_init (&args[0], GST_TYPE_PAD);
3347 g_value_set_object (&args[0], pad);
3348 g_value_init (&args[1], GST_TYPE_MINI_OBJECT); // G_TYPE_POINTER);
3349 gst_value_set_mini_object (&args[1], obj);
3351 if (GST_IS_EVENT (obj))
3352 detail = event_quark;
3354 detail = buffer_quark;
3357 g_signal_emitv (args, gst_pad_signals[PAD_HAVE_DATA], detail, &ret);
3358 res = g_value_get_boolean (&ret);
3361 g_value_unset (&ret);
3362 g_value_unset (&args[0]);
3363 g_value_unset (&args[1]);
3368 /* this is the chain function that does not perform the additional argument
3369 * checking for that little extra speed.
3371 static inline GstFlowReturn
3372 gst_pad_chain_unchecked (GstPad * pad, GstBuffer * buffer)
3375 gboolean caps_changed;
3376 GstPadChainFunction chainfunc;
3378 gboolean emit_signal;
3380 GST_PAD_STREAM_LOCK (pad);
3382 GST_OBJECT_LOCK (pad);
3383 if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad)))
3386 caps = GST_BUFFER_CAPS (buffer);
3387 caps_changed = caps && caps != GST_PAD_CAPS (pad);
3389 emit_signal = GST_PAD_DO_BUFFER_SIGNALS (pad) > 0;
3390 GST_OBJECT_UNLOCK (pad);
3392 /* see if the signal should be emited, we emit before caps nego as
3393 * we might drop the buffer and do capsnego for nothing. */
3394 if (G_UNLIKELY (emit_signal)) {
3395 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (buffer)))
3399 /* we got a new datatype on the pad, see if it can handle it */
3400 if (G_UNLIKELY (caps_changed)) {
3401 GST_DEBUG_OBJECT (pad, "caps changed to %p %" GST_PTR_FORMAT, caps, caps);
3402 if (G_UNLIKELY (!gst_pad_configure_sink (pad, caps)))
3403 goto not_negotiated;
3406 /* NOTE: we read the chainfunc unlocked.
3407 * we cannot hold the lock for the pad so we might send
3408 * the data to the wrong function. This is not really a
3409 * problem since functions are assigned at creation time
3410 * and don't change that often... */
3411 if (G_UNLIKELY ((chainfunc = GST_PAD_CHAINFUNC (pad)) == NULL))
3414 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3415 "calling chainfunction &%s", GST_DEBUG_FUNCPTR_NAME (chainfunc));
3417 ret = chainfunc (pad, buffer);
3419 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3420 "called chainfunction &%s, returned %s",
3421 GST_DEBUG_FUNCPTR_NAME (chainfunc), gst_flow_get_name (ret));
3423 GST_PAD_STREAM_UNLOCK (pad);
3430 gst_buffer_unref (buffer);
3431 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3432 "pushing, but pad was flushing");
3433 GST_OBJECT_UNLOCK (pad);
3434 GST_PAD_STREAM_UNLOCK (pad);
3435 return GST_FLOW_WRONG_STATE;
3439 gst_buffer_unref (buffer);
3440 GST_DEBUG_OBJECT (pad, "Dropping buffer due to FALSE probe return");
3441 GST_PAD_STREAM_UNLOCK (pad);
3446 gst_buffer_unref (buffer);
3447 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3448 "pushing buffer but pad did not accept");
3449 GST_PAD_STREAM_UNLOCK (pad);
3450 return GST_FLOW_NOT_NEGOTIATED;
3454 gst_buffer_unref (buffer);
3455 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3456 "pushing, but not chainhandler");
3457 GST_ELEMENT_ERROR (GST_PAD_PARENT (pad), CORE, PAD, (NULL),
3458 ("push on pad %s:%s but it has no chainfunction",
3459 GST_DEBUG_PAD_NAME (pad)));
3460 GST_PAD_STREAM_UNLOCK (pad);
3461 return GST_FLOW_NOT_SUPPORTED;
3467 * @pad: a sink #GstPad, returns GST_FLOW_ERROR if not.
3468 * @buffer: the #GstBuffer to send, return GST_FLOW_ERROR if not.
3470 * Chain a buffer to @pad.
3472 * The function returns #GST_FLOW_WRONG_STATE if the pad was flushing.
3474 * If the caps on @buffer are different from the current caps on @pad, this
3475 * function will call any setcaps function (see gst_pad_set_setcaps_function())
3476 * installed on @pad. If the new caps are not acceptable for @pad, this function
3477 * returns #GST_FLOW_NOT_NEGOTIATED.
3479 * The function proceeds calling the chain function installed on @pad (see
3480 * gst_pad_set_chain_function()) and the return value of that function is
3481 * returned to the caller. #GST_FLOW_NOT_SUPPORTED is returned if @pad has no
3484 * In all cases, success or failure, the caller loses its reference to @buffer
3485 * after calling this function.
3487 * Returns: a #GstFlowReturn from the pad.
3492 gst_pad_chain (GstPad * pad, GstBuffer * buffer)
3494 g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
3495 g_return_val_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SINK,
3497 g_return_val_if_fail (GST_IS_BUFFER (buffer), GST_FLOW_ERROR);
3499 return gst_pad_chain_unchecked (pad, buffer);
3504 * @pad: a source #GstPad, returns #GST_FLOW_ERROR if not.
3505 * @buffer: the #GstBuffer to push returns GST_FLOW_ERROR if not.
3507 * Pushes a buffer to the peer of @pad.
3509 * This function will call an installed pad block before triggering any
3510 * installed pad probes.
3512 * If the caps on @buffer are different from the currently configured caps on
3513 * @pad, this function will call any installed setcaps function on @pad (see
3514 * gst_pad_set_setcaps_function()). In case of failure to renegotiate the new
3515 * format, this function returns #GST_FLOW_NOT_NEGOTIATED.
3517 * The function proceeds calling gst_pad_chain() on the peer pad and returns the
3518 * value from that function. If @pad has no peer, #GST_FLOW_NOT_LINKED will be
3521 * In all cases, success or failure, the caller loses its reference to @buffer
3522 * after calling this function.
3524 * Returns: a #GstFlowReturn from the peer pad.
3529 gst_pad_push (GstPad * pad, GstBuffer * buffer)
3535 gboolean caps_changed;
3537 g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
3538 g_return_val_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SRC, GST_FLOW_ERROR);
3539 g_return_val_if_fail (GST_IS_BUFFER (buffer), GST_FLOW_ERROR);
3541 GST_OBJECT_LOCK (pad);
3543 /* FIXME: this check can go away; pad_set_blocked could be implemented with
3544 * probes completely or probes with an extended pad block. */
3545 while (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad)))
3546 if ((ret = handle_pad_block (pad)) != GST_FLOW_OK)
3549 /* we emit signals on the pad arg, the peer will have a chance to
3550 * emit in the _chain() function */
3551 if (G_UNLIKELY (GST_PAD_DO_BUFFER_SIGNALS (pad) > 0)) {
3552 /* unlock before emitting */
3553 GST_OBJECT_UNLOCK (pad);
3555 /* if the signal handler returned FALSE, it means we should just drop the
3557 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (buffer)))
3560 GST_OBJECT_LOCK (pad);
3563 if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
3566 /* take ref to peer pad before releasing the lock */
3567 gst_object_ref (peer);
3569 /* Before pushing the buffer to the peer pad, ensure that caps
3570 * are set on this pad */
3571 caps = GST_BUFFER_CAPS (buffer);
3572 caps_changed = caps && caps != GST_PAD_CAPS (pad);
3574 GST_OBJECT_UNLOCK (pad);
3576 /* we got a new datatype from the pad, it had better handle it */
3577 if (G_UNLIKELY (caps_changed)) {
3578 GST_DEBUG_OBJECT (pad, "caps changed to %p %" GST_PTR_FORMAT, caps, caps);
3579 if (G_UNLIKELY (!gst_pad_configure_src (pad, caps, TRUE)))
3580 goto not_negotiated;
3583 ret = gst_pad_chain_unchecked (peer, buffer);
3585 gst_object_unref (peer);
3589 /* ERROR recovery here */
3592 gst_buffer_unref (buffer);
3593 GST_DEBUG_OBJECT (pad, "pad block stopped by flush");
3594 GST_OBJECT_UNLOCK (pad);
3599 gst_buffer_unref (buffer);
3600 GST_DEBUG_OBJECT (pad, "Dropping buffer due to FALSE probe return");
3605 gst_buffer_unref (buffer);
3606 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3607 "pushing, but it was not linked");
3608 GST_OBJECT_UNLOCK (pad);
3609 return GST_FLOW_NOT_LINKED;
3613 gst_buffer_unref (buffer);
3614 gst_object_unref (peer);
3615 GST_CAT_DEBUG_OBJECT (GST_CAT_SCHEDULING, pad,
3616 "element pushed buffer then refused to accept the caps");
3617 return GST_FLOW_NOT_NEGOTIATED;
3622 * gst_pad_check_pull_range:
3623 * @pad: a sink #GstPad.
3625 * Checks if a gst_pad_pull_range() can be performed on the peer
3626 * source pad. This function is used by plugins that want to check
3627 * if they can use random access on the peer source pad.
3629 * The peer sourcepad can implement a custom #GstPadCheckGetRangeFunction
3630 * if it needs to perform some logic to determine if pull_range is
3633 * Returns: a gboolean with the result.
3638 gst_pad_check_pull_range (GstPad * pad)
3642 GstPadCheckGetRangeFunction checkgetrangefunc;
3644 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
3646 GST_OBJECT_LOCK (pad);
3647 if (GST_PAD_DIRECTION (pad) != GST_PAD_SINK)
3648 goto wrong_direction;
3650 if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
3653 gst_object_ref (peer);
3654 GST_OBJECT_UNLOCK (pad);
3656 /* see note in above function */
3657 if (G_LIKELY ((checkgetrangefunc = peer->checkgetrangefunc) == NULL)) {
3658 /* FIXME, kindoff ghetto */
3659 ret = GST_PAD_GETRANGEFUNC (peer) != NULL;
3661 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3662 "calling checkgetrangefunc %s of peer pad %s:%s",
3663 GST_DEBUG_FUNCPTR_NAME (checkgetrangefunc), GST_DEBUG_PAD_NAME (peer));
3665 ret = checkgetrangefunc (peer);
3668 gst_object_unref (peer);
3672 /* ERROR recovery here */
3675 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3676 "checking pull range, but pad must be a sinkpad");
3677 GST_OBJECT_UNLOCK (pad);
3682 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3683 "checking pull range, but it was not linked");
3684 GST_OBJECT_UNLOCK (pad);
3690 * gst_pad_get_range:
3691 * @pad: a src #GstPad, returns #GST_FLOW_ERROR if not.
3692 * @offset: The start offset of the buffer
3693 * @size: The length of the buffer
3694 * @buffer: a pointer to hold the #GstBuffer, returns #GST_FLOW_ERROR if %NULL.
3696 * When @pad is flushing this function returns #GST_FLOW_WRONG_STATE
3699 * Calls the getrange function of @pad, see #GstPadGetRangeFunction for a
3700 * description of a getrange function. If @pad has no getrange function
3701 * installed (see gst_pad_set_getrange_function()) this function returns
3702 * #GST_FLOW_NOT_SUPPORTED.
3704 * @buffer's caps must either be unset or the same as what is already configured
3705 * on @pad. Renegotiation within a running pull-mode pipeline is not supported.
3707 * Returns: a #GstFlowReturn from the pad.
3712 gst_pad_get_range (GstPad * pad, guint64 offset, guint size,
3713 GstBuffer ** buffer)
3716 GstPadGetRangeFunction getrangefunc;
3717 gboolean emit_signal;
3719 g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
3720 g_return_val_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SRC, GST_FLOW_ERROR);
3721 g_return_val_if_fail (buffer != NULL, GST_FLOW_ERROR);
3723 GST_PAD_STREAM_LOCK (pad);
3725 GST_OBJECT_LOCK (pad);
3726 if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad)))
3729 emit_signal = GST_PAD_DO_BUFFER_SIGNALS (pad) > 0;
3730 GST_OBJECT_UNLOCK (pad);
3732 if (G_UNLIKELY ((getrangefunc = GST_PAD_GETRANGEFUNC (pad)) == NULL))
3735 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3736 "calling getrangefunc %s, offset %"
3737 G_GUINT64_FORMAT ", size %u",
3738 GST_DEBUG_FUNCPTR_NAME (getrangefunc), offset, size);
3740 ret = getrangefunc (pad, offset, size, buffer);
3742 /* can only fire the signal if we have a valid buffer */
3743 if (G_UNLIKELY (emit_signal) && (ret == GST_FLOW_OK)) {
3744 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (*buffer)))
3748 GST_PAD_STREAM_UNLOCK (pad);
3750 if (G_LIKELY (ret == GST_FLOW_OK)) {
3752 gboolean caps_changed;
3754 GST_OBJECT_LOCK (pad);
3755 /* Before pushing the buffer to the peer pad, ensure that caps
3756 * are set on this pad */
3757 caps = GST_BUFFER_CAPS (*buffer);
3758 caps_changed = caps && caps != GST_PAD_CAPS (pad);
3759 GST_OBJECT_UNLOCK (pad);
3761 /* we got a new datatype from the pad not supported in a running pull-mode
3763 if (G_UNLIKELY (caps_changed))
3764 goto not_negotiated;
3772 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3773 "pulling range, but pad was flushing");
3774 GST_OBJECT_UNLOCK (pad);
3775 GST_PAD_STREAM_UNLOCK (pad);
3776 return GST_FLOW_WRONG_STATE;
3780 GST_ELEMENT_ERROR (GST_PAD_PARENT (pad), CORE, PAD, (NULL),
3781 ("pullrange on pad %s:%s but it has no getrangefunction",
3782 GST_DEBUG_PAD_NAME (pad)));
3783 GST_PAD_STREAM_UNLOCK (pad);
3784 return GST_FLOW_NOT_SUPPORTED;
3788 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3789 "Dropping data after FALSE probe return");
3790 GST_PAD_STREAM_UNLOCK (pad);
3791 gst_buffer_unref (*buffer);
3793 return GST_FLOW_UNEXPECTED;
3797 /* ideally we want to use the commented-out code, but currently demuxers and
3798 * typefind do not follow part-negotiation.txt. When switching into pull
3799 * mode, typefind should probably return the found caps from getcaps(), and
3800 * demuxers should do the setcaps(). */
3803 gst_buffer_unref (*buffer);
3805 GST_CAT_WARNING_OBJECT (GST_CAT_SCHEDULING, pad,
3806 "getrange returned buffer of different caps");
3807 return GST_FLOW_NOT_NEGOTIATED;
3809 GST_CAT_DEBUG_OBJECT (GST_CAT_SCHEDULING, pad,
3810 "getrange returned buffer of different caps");
3817 * gst_pad_pull_range:
3818 * @pad: a sink #GstPad, returns GST_FLOW_ERROR if not.
3819 * @offset: The start offset of the buffer
3820 * @size: The length of the buffer
3821 * @buffer: a pointer to hold the #GstBuffer, returns GST_FLOW_ERROR if %NULL.
3823 * Pulls a buffer from the peer pad.
3825 * This function will first trigger the pad block signal if it was
3828 * When @pad is not linked #GST_FLOW_NOT_LINKED is returned else this
3829 * function returns the result of gst_pad_get_range() on the peer pad.
3830 * See gst_pad_get_range() for a list of return values and for the
3831 * semantics of the arguments of this function.
3833 * @buffer's caps must either be unset or the same as what is already configured
3834 * on @pad. Renegotiation within a running pull-mode pipeline is not supported.
3836 * Returns: a #GstFlowReturn from the peer pad.
3837 * When this function returns #GST_FLOW_OK, @buffer will contain a valid
3838 * #GstBuffer that should be freed with gst_buffer_unref() after usage.
3839 * @buffer may not be used or freed when any other return value than
3840 * #GST_FLOW_OK is returned.
3845 gst_pad_pull_range (GstPad * pad, guint64 offset, guint size,
3846 GstBuffer ** buffer)
3850 gboolean emit_signal;
3852 g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
3853 g_return_val_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SINK,
3855 g_return_val_if_fail (buffer != NULL, GST_FLOW_ERROR);
3857 GST_OBJECT_LOCK (pad);
3859 while (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad)))
3860 handle_pad_block (pad);
3862 if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
3865 /* signal emision for the pad, peer has chance to emit when
3866 * we call _get_range() */
3867 emit_signal = GST_PAD_DO_BUFFER_SIGNALS (pad) > 0;
3869 gst_object_ref (peer);
3870 GST_OBJECT_UNLOCK (pad);
3872 ret = gst_pad_get_range (peer, offset, size, buffer);
3874 gst_object_unref (peer);
3876 /* can only fire the signal if we have a valid buffer */
3877 if (G_UNLIKELY (emit_signal) && (ret == GST_FLOW_OK)) {
3878 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (*buffer)))
3882 if (G_LIKELY (ret == GST_FLOW_OK)) {
3884 gboolean caps_changed;
3886 GST_OBJECT_LOCK (pad);
3887 /* Before pushing the buffer to the peer pad, ensure that caps
3888 * are set on this pad */
3889 caps = GST_BUFFER_CAPS (*buffer);
3890 caps_changed = caps && caps != GST_PAD_CAPS (pad);
3891 GST_OBJECT_UNLOCK (pad);
3893 /* we got a new datatype on the pad, see if it can handle it */
3894 if (G_UNLIKELY (caps_changed))
3895 goto not_negotiated;
3900 /* ERROR recovery here */
3903 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3904 "pulling range, but it was not linked");
3905 GST_OBJECT_UNLOCK (pad);
3906 return GST_FLOW_NOT_LINKED;
3910 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3911 "Dropping data after FALSE probe return");
3912 gst_buffer_unref (*buffer);
3914 return GST_FLOW_UNEXPECTED;
3918 /* ideally we want to use the commented-out code, but currently demuxers and
3919 * typefind do not follow part-negotiation.txt. When switching into pull
3920 * mode, typefind should probably return the found caps from getcaps(), and
3921 * demuxers should do the setcaps(). */
3924 gst_buffer_unref (*buffer);
3926 GST_CAT_WARNING_OBJECT (GST_CAT_SCHEDULING, pad,
3927 "pullrange returned buffer of different caps");
3928 return GST_FLOW_NOT_NEGOTIATED;
3930 GST_CAT_DEBUG_OBJECT (GST_CAT_SCHEDULING, pad,
3931 "pullrange returned buffer of different caps");
3937 * gst_pad_push_event:
3938 * @pad: a #GstPad to push the event to.
3939 * @event: the #GstEvent to send to the pad.
3941 * Sends the event to the peer of the given pad. This function is
3942 * mainly used by elements to send events to their peer
3945 * This function takes owership of the provided event so you should
3946 * gst_event_ref() it if you want to reuse the event after this call.
3948 * Returns: TRUE if the event was handled.
3953 gst_pad_push_event (GstPad * pad, GstEvent * event)
3958 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
3959 g_return_val_if_fail (event != NULL, FALSE);
3960 g_return_val_if_fail (GST_IS_EVENT (event), FALSE);
3962 GST_LOG_OBJECT (pad, "event: %s", GST_EVENT_TYPE_NAME (event));
3964 GST_OBJECT_LOCK (pad);
3966 /* Two checks to be made:
3967 * . (un)set the FLUSHING flag for flushing events,
3968 * . handle pad blocking */
3969 switch (GST_EVENT_TYPE (event)) {
3970 case GST_EVENT_FLUSH_START:
3971 GST_PAD_SET_FLUSHING (pad);
3973 if (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad))) {
3974 /* flush start will have set the FLUSHING flag and will then
3975 * unlock all threads doing a GCond wait on the blocking pad. This
3976 * will typically unblock the STREAMING thread blocked on a pad. */
3977 GST_LOG_OBJECT (pad, "Pad is blocked, not forwarding flush-start, "
3978 "doing block signal.");
3979 GST_PAD_BLOCK_BROADCAST (pad);
3983 case GST_EVENT_FLUSH_STOP:
3984 GST_PAD_UNSET_FLUSHING (pad);
3986 /* if we are blocked, flush away the FLUSH_STOP event */
3987 if (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad))) {
3988 GST_LOG_OBJECT (pad, "Pad is blocked, not forwarding flush-stop");
3993 while (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad))) {
3994 /* block the event as long as the pad is blocked */
3995 if (handle_pad_block (pad) != GST_FLOW_OK)
4001 if (G_UNLIKELY (GST_PAD_DO_EVENT_SIGNALS (pad) > 0)) {
4002 GST_OBJECT_UNLOCK (pad);
4004 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (event)))
4007 GST_OBJECT_LOCK (pad);
4009 peerpad = GST_PAD_PEER (pad);
4010 if (peerpad == NULL)
4013 GST_LOG_OBJECT (pad, "sending event %s to peerpad %" GST_PTR_FORMAT,
4014 GST_EVENT_TYPE_NAME (event), peerpad);
4015 gst_object_ref (peerpad);
4016 GST_OBJECT_UNLOCK (pad);
4018 result = gst_pad_send_event (peerpad, event);
4020 /* Note: we gave away ownership of the event at this point */
4021 GST_LOG_OBJECT (pad, "sent event to peerpad %" GST_PTR_FORMAT, peerpad);
4022 gst_object_unref (peerpad);
4026 /* ERROR handling */
4029 GST_DEBUG_OBJECT (pad, "Dropping event after FALSE probe return");
4030 gst_event_unref (event);
4035 GST_DEBUG_OBJECT (pad, "Dropping event because pad is not linked");
4036 gst_event_unref (event);
4037 GST_OBJECT_UNLOCK (pad);
4042 GST_DEBUG_OBJECT (pad,
4043 "Not forwarding event since we're flushing and blocking");
4044 gst_event_unref (event);
4045 GST_OBJECT_UNLOCK (pad);
4051 * gst_pad_send_event:
4052 * @pad: a #GstPad to send the event to.
4053 * @event: the #GstEvent to send to the pad.
4055 * Sends the event to the pad. This function can be used
4056 * by applications to send events in the pipeline.
4058 * If @pad is a source pad, @event should be an upstream event. If @pad is a
4059 * sink pad, @event should be a downstream event. For example, you would not
4060 * send a #GST_EVENT_EOS on a src pad; EOS events only propagate downstream.
4061 * Furthermore, some downstream events have to be serialized with data flow,
4062 * like EOS, while some can travel out-of-band, like #GST_EVENT_FLUSH_START. If
4063 * the event needs to be serialized with data flow, this function will take the
4064 * pad's stream lock while calling its event function.
4066 * To find out whether an event type is upstream, downstream, or downstream and
4067 * serialized, see #GstEventTypeFlags, gst_event_type_get_flags(),
4068 * #GST_EVENT_IS_UPSTREAM, #GST_EVENT_IS_DOWNSTREAM, and
4069 * #GST_EVENT_IS_SERIALIZED. Note that in practice that an application or plugin
4070 * doesn't need to bother itself with this information; the core handles all
4071 * necessary locks and checks.
4073 * This function takes owership of the provided event so you should
4074 * gst_event_ref() it if you want to reuse the event after this call.
4076 * Returns: TRUE if the event was handled.
4079 gst_pad_send_event (GstPad * pad, GstEvent * event)
4081 gboolean result = FALSE;
4082 GstPadEventFunction eventfunc;
4083 gboolean serialized, need_unlock = FALSE;
4085 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
4086 g_return_val_if_fail (event != NULL, FALSE);
4088 GST_OBJECT_LOCK (pad);
4089 if (GST_PAD_IS_SINK (pad)) {
4090 if (G_UNLIKELY (!GST_EVENT_IS_DOWNSTREAM (event)))
4091 goto wrong_direction;
4092 serialized = GST_EVENT_IS_SERIALIZED (event);
4093 } else if (GST_PAD_IS_SRC (pad)) {
4094 if (G_UNLIKELY (!GST_EVENT_IS_UPSTREAM (event)))
4095 goto wrong_direction;
4096 /* events on srcpad never are serialized */
4099 goto unknown_direction;
4101 if (G_UNLIKELY (GST_EVENT_SRC (event) == NULL)) {
4102 GST_LOG_OBJECT (pad, "event had no source, setting pad as event source");
4103 GST_EVENT_SRC (event) = gst_object_ref (pad);
4107 if (G_UNLIKELY (GST_PAD_DO_EVENT_SIGNALS (pad) > 0)) {
4108 GST_OBJECT_UNLOCK (pad);
4110 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT_CAST (event)))
4113 GST_OBJECT_LOCK (pad);
4116 switch (GST_EVENT_TYPE (event)) {
4117 case GST_EVENT_FLUSH_START:
4118 GST_CAT_DEBUG_OBJECT (GST_CAT_EVENT, pad,
4119 "have event type %d (FLUSH_START)", GST_EVENT_TYPE (event));
4121 /* can't even accept a flush begin event when flushing */
4122 if (GST_PAD_IS_FLUSHING (pad))
4124 GST_PAD_SET_FLUSHING (pad);
4125 GST_CAT_DEBUG_OBJECT (GST_CAT_EVENT, pad, "set flush flag");
4127 case GST_EVENT_FLUSH_STOP:
4128 GST_PAD_UNSET_FLUSHING (pad);
4129 GST_CAT_DEBUG_OBJECT (GST_CAT_EVENT, pad, "cleared flush flag");
4130 GST_OBJECT_UNLOCK (pad);
4131 /* grab stream lock */
4132 GST_PAD_STREAM_LOCK (pad);
4134 GST_OBJECT_LOCK (pad);
4137 GST_CAT_DEBUG_OBJECT (GST_CAT_EVENT, pad, "have event type %s",
4138 GST_EVENT_TYPE_NAME (event));
4140 /* make this a little faster, no point in grabbing the lock
4141 * if the pad is allready flushing. */
4142 if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad)))
4146 /* lock order: STREAM_LOCK, LOCK, recheck flushing. */
4147 GST_OBJECT_UNLOCK (pad);
4148 GST_PAD_STREAM_LOCK (pad);
4150 GST_OBJECT_LOCK (pad);
4151 if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad)))
4156 if (G_UNLIKELY ((eventfunc = GST_PAD_EVENTFUNC (pad)) == NULL))
4159 GST_OBJECT_UNLOCK (pad);
4161 result = eventfunc (pad, event);
4164 GST_PAD_STREAM_UNLOCK (pad);
4168 /* ERROR handling */
4171 g_warning ("pad %s:%s sending %s event in wrong direction",
4172 GST_DEBUG_PAD_NAME (pad), GST_EVENT_TYPE_NAME (event));
4173 GST_OBJECT_UNLOCK (pad);
4174 gst_event_unref (event);
4179 g_warning ("pad %s:%s has invalid direction", GST_DEBUG_PAD_NAME (pad));
4180 GST_OBJECT_UNLOCK (pad);
4181 gst_event_unref (event);
4186 g_warning ("pad %s:%s has no event handler, file a bug.",
4187 GST_DEBUG_PAD_NAME (pad));
4188 GST_OBJECT_UNLOCK (pad);
4189 gst_event_unref (event);
4194 GST_OBJECT_UNLOCK (pad);
4196 GST_PAD_STREAM_UNLOCK (pad);
4197 GST_CAT_INFO_OBJECT (GST_CAT_EVENT, pad,
4198 "Received event on flushing pad. Discarding");
4199 gst_event_unref (event);
4204 GST_DEBUG_OBJECT (pad, "Dropping event after FALSE probe return");
4205 gst_event_unref (event);
4211 * gst_pad_set_element_private:
4212 * @pad: the #GstPad to set the private data of.
4213 * @priv: The private data to attach to the pad.
4215 * Set the given private data gpointer on the pad.
4216 * This function can only be used by the element that owns the pad.
4217 * No locking is performed in this function.
4220 gst_pad_set_element_private (GstPad * pad, gpointer priv)
4222 pad->element_private = priv;
4226 * gst_pad_get_element_private:
4227 * @pad: the #GstPad to get the private data of.
4229 * Gets the private data of a pad.
4230 * No locking is performed in this function.
4232 * Returns: a #gpointer to the private data.
4235 gst_pad_get_element_private (GstPad * pad)
4237 return pad->element_private;
4241 * gst_pad_start_task:
4242 * @pad: the #GstPad to start the task of
4243 * @func: the task function to call
4244 * @data: data passed to the task function
4246 * Starts a task that repeatedly calls @func with @data. This function
4247 * is mostly used in pad activation functions to start the dataflow.
4248 * The #GST_PAD_STREAM_LOCK of @pad will automatically be acquired
4249 * before @func is called.
4251 * Returns: a %TRUE if the task could be started.
4254 gst_pad_start_task (GstPad * pad, GstTaskFunction func, gpointer data)
4258 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
4259 g_return_val_if_fail (func != NULL, FALSE);
4261 GST_DEBUG_OBJECT (pad, "start task");
4263 GST_OBJECT_LOCK (pad);
4264 task = GST_PAD_TASK (pad);
4266 task = gst_task_create (func, data);
4267 gst_task_set_lock (task, GST_PAD_GET_STREAM_LOCK (pad));
4268 GST_PAD_TASK (pad) = task;
4269 GST_DEBUG_OBJECT (pad, "created task");
4271 gst_task_start (task);
4272 GST_OBJECT_UNLOCK (pad);
4278 * gst_pad_pause_task:
4279 * @pad: the #GstPad to pause the task of
4281 * Pause the task of @pad. This function will also make sure that the
4282 * function executed by the task will effectively stop.
4284 * Returns: a TRUE if the task could be paused or FALSE when the pad
4288 gst_pad_pause_task (GstPad * pad)
4292 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
4294 GST_DEBUG_OBJECT (pad, "pause task");
4296 GST_OBJECT_LOCK (pad);
4297 task = GST_PAD_TASK (pad);
4300 gst_task_pause (task);
4301 GST_OBJECT_UNLOCK (pad);
4303 GST_PAD_STREAM_LOCK (pad);
4304 GST_PAD_STREAM_UNLOCK (pad);
4310 GST_DEBUG_OBJECT (pad, "pad has no task");
4311 GST_OBJECT_UNLOCK (pad);
4317 * gst_pad_stop_task:
4318 * @pad: the #GstPad to stop the task of
4320 * Stop the task of @pad. This function will also make sure that the
4321 * function executed by the task will effectively stop if not called
4322 * from the GstTaskFunction.
4324 * This function will deadlock if called from the GstTaskFunction of
4325 * the task. Use gst_task_pause() instead.
4327 * Regardless of whether the pad has a task, the stream lock is acquired and
4328 * released so as to ensure that streaming through this pad has finished.
4330 * Returns: a TRUE if the task could be stopped or FALSE on error.
4333 gst_pad_stop_task (GstPad * pad)
4337 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
4339 GST_DEBUG_OBJECT (pad, "stop task");
4341 GST_OBJECT_LOCK (pad);
4342 task = GST_PAD_TASK (pad);
4345 GST_PAD_TASK (pad) = NULL;
4346 gst_task_stop (task);
4347 GST_OBJECT_UNLOCK (pad);
4349 GST_PAD_STREAM_LOCK (pad);
4350 GST_PAD_STREAM_UNLOCK (pad);
4352 if (!gst_task_join (task))
4355 gst_object_unref (task);
4361 GST_DEBUG_OBJECT (pad, "no task");
4362 GST_OBJECT_UNLOCK (pad);
4364 GST_PAD_STREAM_LOCK (pad);
4365 GST_PAD_STREAM_UNLOCK (pad);
4367 /* this is not an error */
4372 /* this is bad, possibly the application tried to join the task from
4373 * the task's thread. We install the task again so that it will be stopped
4374 * again from the right thread next time hopefully. */
4375 GST_OBJECT_LOCK (pad);
4376 GST_DEBUG_OBJECT (pad, "join failed");
4377 /* we can only install this task if there was no other task */
4378 if (GST_PAD_TASK (pad) == NULL)
4379 GST_PAD_TASK (pad) = task;
4380 GST_OBJECT_UNLOCK (pad);