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 /* FIXME, should be set flushing initially, see #339326 */
356 GST_PAD_UNSET_FLUSHING (pad);
358 pad->preroll_lock = g_mutex_new ();
359 pad->preroll_cond = g_cond_new ();
361 pad->stream_rec_lock = g_new (GStaticRecMutex, 1);
362 g_static_rec_mutex_init (pad->stream_rec_lock);
364 pad->block_cond = g_cond_new ();
368 gst_pad_dispose (GObject * object)
370 GstPad *pad = GST_PAD (object);
372 GST_CAT_DEBUG_OBJECT (GST_CAT_REFCOUNTING, pad, "dispose");
374 /* we don't hold a ref to the peer so we can just set the
376 GST_PAD_PEER (pad) = NULL;
379 gst_caps_replace (&GST_PAD_CAPS (pad), NULL);
381 gst_pad_set_pad_template (pad, NULL);
383 G_OBJECT_CLASS (parent_class)->dispose (object);
387 gst_pad_finalize (GObject * object)
389 GstPad *pad = GST_PAD (object);
392 /* in case the task is still around, clean it up */
393 if ((task = GST_PAD_TASK (pad))) {
394 gst_task_join (task);
395 GST_PAD_TASK (pad) = NULL;
396 gst_object_unref (task);
399 if (pad->stream_rec_lock) {
400 g_static_rec_mutex_free (pad->stream_rec_lock);
401 g_free (pad->stream_rec_lock);
402 pad->stream_rec_lock = NULL;
404 if (pad->preroll_lock) {
405 g_mutex_free (pad->preroll_lock);
406 g_cond_free (pad->preroll_cond);
407 pad->preroll_lock = NULL;
408 pad->preroll_cond = NULL;
410 if (pad->block_cond) {
411 g_cond_free (pad->block_cond);
412 pad->block_cond = NULL;
415 G_OBJECT_CLASS (parent_class)->finalize (object);
419 gst_pad_set_property (GObject * object, guint prop_id,
420 const GValue * value, GParamSpec * pspec)
422 g_return_if_fail (GST_IS_PAD (object));
425 case PAD_PROP_DIRECTION:
426 GST_PAD_DIRECTION (object) = g_value_get_enum (value);
428 case PAD_PROP_TEMPLATE:
429 gst_pad_set_pad_template (GST_PAD_CAST (object),
430 (GstPadTemplate *) g_value_get_object (value));
433 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
439 gst_pad_get_property (GObject * object, guint prop_id,
440 GValue * value, GParamSpec * pspec)
442 g_return_if_fail (GST_IS_PAD (object));
446 GST_OBJECT_LOCK (object);
447 g_value_set_boxed (value, GST_PAD_CAPS (object));
448 GST_OBJECT_UNLOCK (object);
450 case PAD_PROP_DIRECTION:
451 g_value_set_enum (value, GST_PAD_DIRECTION (object));
453 case PAD_PROP_TEMPLATE:
454 g_value_set_object (value, GST_PAD_PAD_TEMPLATE (object));
457 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
464 * @name: the name of the new pad.
465 * @direction: the #GstPadDirection of the pad.
467 * Creates a new pad with the given name in the given direction.
468 * If name is NULL, a guaranteed unique name (across all pads)
470 * This function makes a copy of the name so you can safely free the name.
472 * Returns: a new #GstPad, or NULL in case of an error.
477 gst_pad_new (const gchar * name, GstPadDirection direction)
479 return g_object_new (GST_TYPE_PAD,
480 "name", name, "direction", direction, NULL);
484 * gst_pad_new_from_template:
485 * @templ: the pad template to use
486 * @name: the name of the element
488 * Creates a new pad with the given name from the given template.
489 * If name is NULL, a guaranteed unique name (across all pads)
491 * This function makes a copy of the name so you can safely free the name.
493 * Returns: a new #GstPad, or NULL in case of an error.
496 gst_pad_new_from_template (GstPadTemplate * templ, const gchar * name)
498 g_return_val_if_fail (GST_IS_PAD_TEMPLATE (templ), NULL);
500 return g_object_new (GST_TYPE_PAD,
501 "name", name, "direction", templ->direction, "template", templ, NULL);
505 * gst_pad_new_from_static_template:
506 * @templ: the #GstStaticPadTemplate to use
507 * @name: the name of the element
509 * Creates a new pad with the given name from the given static template.
510 * If name is NULL, a guaranteed unique name (across all pads)
512 * This function makes a copy of the name so you can safely free the name.
514 * Returns: a new #GstPad, or NULL in case of an error.
517 gst_pad_new_from_static_template (GstStaticPadTemplate * templ,
521 GstPadTemplate *template;
523 template = gst_static_pad_template_get (templ);
524 pad = gst_pad_new_from_template (template, name);
525 gst_object_unref (template);
530 * gst_pad_get_direction:
531 * @pad: a #GstPad to get the direction of.
533 * Gets the direction of the pad. The direction of the pad is
534 * decided at construction time so this function does not take
537 * Returns: the #GstPadDirection of the pad.
542 gst_pad_get_direction (GstPad * pad)
544 GstPadDirection result;
546 /* PAD_UNKNOWN is a little silly but we need some sort of
547 * error return value */
548 g_return_val_if_fail (GST_IS_PAD (pad), GST_PAD_UNKNOWN);
550 GST_OBJECT_LOCK (pad);
551 result = GST_PAD_DIRECTION (pad);
552 GST_OBJECT_UNLOCK (pad);
558 gst_pad_activate_default (GstPad * pad)
560 return gst_pad_activate_push (pad, TRUE);
564 pre_activate (GstPad * pad, GstActivateMode new_mode)
567 case GST_ACTIVATE_PUSH:
568 case GST_ACTIVATE_PULL:
569 GST_OBJECT_LOCK (pad);
570 GST_DEBUG_OBJECT (pad, "setting ACTIVATE_MODE %d, unset flushing",
572 GST_PAD_UNSET_FLUSHING (pad);
573 GST_PAD_ACTIVATE_MODE (pad) = new_mode;
574 GST_OBJECT_UNLOCK (pad);
576 case GST_ACTIVATE_NONE:
577 GST_OBJECT_LOCK (pad);
578 GST_DEBUG_OBJECT (pad, "setting ACTIVATE_MODE NONE, set flushing",
580 GST_PAD_SET_FLUSHING (pad);
581 /* unlock blocked pads so element can resume and stop */
582 GST_PAD_BLOCK_SIGNAL (pad);
583 GST_OBJECT_UNLOCK (pad);
589 post_activate (GstPad * pad, GstActivateMode new_mode)
592 case GST_ACTIVATE_PUSH:
593 case GST_ACTIVATE_PULL:
596 case GST_ACTIVATE_NONE:
597 /* ensures that streaming stops */
598 GST_PAD_STREAM_LOCK (pad);
599 /* while we're at it set activation mode */
600 GST_OBJECT_LOCK (pad);
601 GST_DEBUG_OBJECT (pad, "setting ACTIVATE_MODE %d", new_mode);
602 GST_PAD_ACTIVATE_MODE (pad) = new_mode;
603 GST_OBJECT_UNLOCK (pad);
604 GST_PAD_STREAM_UNLOCK (pad);
610 * gst_pad_set_active:
611 * @pad: the #GstPad to activate or deactivate.
612 * @active: whether or not the pad should be active.
614 * Activates or deactivates the given pad.
615 * Normally called from within core state change functions.
617 * If @active, makes sure the pad is active. If it is already active, either in
618 * push or pull mode, just return. Otherwise dispatches to the pad's activate
619 * function to perform the actual activation.
621 * If not @active, checks the pad's current mode and calls
622 * gst_pad_activate_push() or gst_pad_activate_pull(), as appropriate, with a
625 * Returns: #TRUE if the operation was successful.
630 gst_pad_set_active (GstPad * pad, gboolean active)
633 gboolean ret = FALSE;
635 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
637 GST_OBJECT_LOCK (pad);
638 old = GST_PAD_ACTIVATE_MODE (pad);
639 GST_OBJECT_UNLOCK (pad);
643 case GST_ACTIVATE_PUSH:
644 case GST_ACTIVATE_PULL:
647 case GST_ACTIVATE_NONE:
648 ret = (GST_PAD_ACTIVATEFUNC (pad)) (pad);
653 case GST_ACTIVATE_PUSH:
654 ret = gst_pad_activate_push (pad, FALSE);
656 case GST_ACTIVATE_PULL:
657 ret = gst_pad_activate_pull (pad, FALSE);
659 case GST_ACTIVATE_NONE:
666 GST_OBJECT_LOCK (pad);
668 g_critical ("Failed to deactivate pad %s:%s, very bad",
669 GST_DEBUG_PAD_NAME (pad));
671 GST_WARNING ("Failed to activate pad %s:%s", GST_DEBUG_PAD_NAME (pad));
673 GST_OBJECT_UNLOCK (pad);
680 * gst_pad_activate_pull:
681 * @pad: the #GstPad to activate or deactivate.
682 * @active: whether or not the pad should be active.
684 * Activates or deactivates the given pad in pull mode via dispatching to the
685 * pad's activatepullfunc. For use from within pad activation functions only.
686 * When called on sink pads, will first proxy the call to the peer pad, which is
687 * expected to activate its internally linked pads from within its activate_pull
690 * If you don't know what this is, you probably don't want to call it.
692 * Returns: TRUE if the operation was successful.
697 gst_pad_activate_pull (GstPad * pad, gboolean active)
699 GstActivateMode old, new;
702 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
704 GST_OBJECT_LOCK (pad);
705 old = GST_PAD_ACTIVATE_MODE (pad);
706 GST_OBJECT_UNLOCK (pad);
710 case GST_ACTIVATE_PULL:
712 case GST_ACTIVATE_PUSH:
713 /* pad was activate in the wrong direction, deactivate it
714 * and reactivate it in pull mode */
715 if (G_UNLIKELY (!gst_pad_activate_push (pad, FALSE)))
716 goto deactivate_failed;
717 /* fallthrough, pad is deactivated now. */
718 case GST_ACTIVATE_NONE:
723 case GST_ACTIVATE_NONE:
725 case GST_ACTIVATE_PUSH:
726 /* pad was activated in the other direction, deactivate it
727 * in push mode, this should not happen... */
728 if (G_UNLIKELY (!gst_pad_activate_push (pad, FALSE)))
729 goto deactivate_failed;
730 /* everything is fine now */
732 case GST_ACTIVATE_PULL:
737 if (gst_pad_get_direction (pad) == GST_PAD_SINK) {
738 if ((peer = gst_pad_get_peer (pad))) {
739 if (G_UNLIKELY (!gst_pad_activate_pull (peer, active)))
741 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_OBJECT_LOCK (pad);
791 GST_CAT_INFO_OBJECT (GST_CAT_PADS, pad, "failed to %s in pull mode",
792 active ? "activate" : "deactivate");
793 GST_PAD_SET_FLUSHING (pad);
794 GST_PAD_ACTIVATE_MODE (pad) = old;
795 GST_OBJECT_UNLOCK (pad);
801 * gst_pad_activate_push:
802 * @pad: the #GstPad to activate or deactivate.
803 * @active: whether the pad should be active or not.
805 * Activates or deactivates the given pad in push mode via dispatching to the
806 * pad's activatepushfunc. For use from within pad activation functions only.
808 * If you don't know what this is, you probably don't want to call it.
810 * Returns: %TRUE if the operation was successful.
815 gst_pad_activate_push (GstPad * pad, gboolean active)
817 GstActivateMode old, new;
819 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
820 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "trying to set %s in push mode",
821 active ? "activated" : "deactivated");
823 GST_OBJECT_LOCK (pad);
824 old = GST_PAD_ACTIVATE_MODE (pad);
825 GST_OBJECT_UNLOCK (pad);
829 case GST_ACTIVATE_PUSH:
831 case GST_ACTIVATE_PULL:
832 /* pad was activate in the wrong direction, deactivate it
833 * an reactivate it in push mode */
834 if (G_UNLIKELY (!gst_pad_activate_pull (pad, FALSE)))
835 goto deactivate_failed;
836 /* fallthrough, pad is deactivated now. */
837 case GST_ACTIVATE_NONE:
842 case GST_ACTIVATE_NONE:
844 case GST_ACTIVATE_PULL:
845 /* pad was activated in the other direction, deactivate it
846 * in pull mode, this should not happen... */
847 if (G_UNLIKELY (!gst_pad_activate_pull (pad, FALSE)))
848 goto deactivate_failed;
849 /* everything is fine now */
851 case GST_ACTIVATE_PUSH:
856 new = active ? GST_ACTIVATE_PUSH : GST_ACTIVATE_NONE;
857 pre_activate (pad, new);
859 if (GST_PAD_ACTIVATEPUSHFUNC (pad)) {
860 if (G_UNLIKELY (!GST_PAD_ACTIVATEPUSHFUNC (pad) (pad, active))) {
864 /* quite ok, element relies on state change func to prepare itself */
867 post_activate (pad, new);
869 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "%s in push mode",
870 active ? "activated" : "deactivated");
875 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "already %s in push mode",
876 active ? "activated" : "deactivated");
881 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
882 "failed to %s in switch to push from mode %d",
883 (active ? "activate" : "deactivate"), old);
888 GST_OBJECT_LOCK (pad);
889 GST_CAT_INFO_OBJECT (GST_CAT_PADS, pad, "failed to %s in push mode",
890 active ? "activate" : "deactivate");
891 GST_PAD_SET_FLUSHING (pad);
892 GST_PAD_ACTIVATE_MODE (pad) = old;
893 GST_OBJECT_UNLOCK (pad);
900 * @pad: the #GstPad to query
902 * Query if a pad is active
904 * Returns: TRUE if the pad is active.
909 gst_pad_is_active (GstPad * pad)
911 gboolean result = FALSE;
913 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
915 GST_OBJECT_LOCK (pad);
916 result = GST_PAD_MODE_ACTIVATE (GST_PAD_ACTIVATE_MODE (pad));
917 GST_OBJECT_UNLOCK (pad);
923 * gst_pad_set_blocked_async:
924 * @pad: the #GstPad to block or unblock
925 * @blocked: boolean indicating whether the pad should be blocked or unblocked
926 * @callback: #GstPadBlockCallback that will be called when the
928 * @user_data: user data passed to the callback
930 * Blocks or unblocks the dataflow on a pad. The provided callback
931 * is called when the operation succeeds; this happens right before the next
932 * attempt at pushing a buffer on the pad.
934 * This can take a while as the pad can only become blocked when real dataflow
936 * When the pipeline is stalled, for example in PAUSED, this can
937 * take an indeterminate amount of time.
938 * You can pass NULL as the callback to make this call block. Be careful with
939 * this blocking call as it might not return for reasons stated above.
941 * Returns: TRUE if the pad could be blocked. This function can fail
942 * if wrong parameters were passed or the pad was already in the
948 gst_pad_set_blocked_async (GstPad * pad, gboolean blocked,
949 GstPadBlockCallback callback, gpointer user_data)
951 gboolean was_blocked = FALSE;
953 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
955 GST_OBJECT_LOCK (pad);
957 was_blocked = GST_PAD_IS_BLOCKED (pad);
959 if (G_UNLIKELY (was_blocked == blocked))
960 goto had_right_state;
963 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "blocking pad");
965 GST_OBJECT_FLAG_SET (pad, GST_PAD_BLOCKED);
966 pad->block_callback = callback;
967 pad->block_data = user_data;
969 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "waiting for block");
970 GST_PAD_BLOCK_WAIT (pad);
971 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "blocked");
974 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "unblocking pad");
976 GST_OBJECT_FLAG_UNSET (pad, GST_PAD_BLOCKED);
978 pad->block_callback = callback;
979 pad->block_data = user_data;
982 GST_PAD_BLOCK_SIGNAL (pad);
984 GST_PAD_BLOCK_SIGNAL (pad);
985 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "waiting for unblock");
986 GST_PAD_BLOCK_WAIT (pad);
987 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "unblocked");
990 GST_OBJECT_UNLOCK (pad);
996 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
997 "pad was in right state (%d)", was_blocked);
998 GST_OBJECT_UNLOCK (pad);
1005 * gst_pad_set_blocked:
1006 * @pad: the #GstPad to block or unblock
1007 * @blocked: boolean indicating we should block or unblock
1009 * Blocks or unblocks the dataflow on a pad. This function is
1010 * a shortcut for gst_pad_set_blocked_async() with a NULL
1013 * Returns: TRUE if the pad could be blocked. This function can fail
1014 * wrong parameters were passed or the pad was already in the
1020 gst_pad_set_blocked (GstPad * pad, gboolean blocked)
1022 return gst_pad_set_blocked_async (pad, blocked, NULL, NULL);
1026 * gst_pad_is_blocked:
1027 * @pad: the #GstPad to query
1029 * Checks if the pad is blocked or not. This function returns the
1030 * last requested state of the pad. It is not certain that the pad
1031 * is actually blocked at this point.
1033 * Returns: TRUE if the pad is blocked.
1038 gst_pad_is_blocked (GstPad * pad)
1040 gboolean result = FALSE;
1042 g_return_val_if_fail (GST_IS_PAD (pad), result);
1044 GST_OBJECT_LOCK (pad);
1045 result = GST_OBJECT_FLAG_IS_SET (pad, GST_PAD_BLOCKED);
1046 GST_OBJECT_UNLOCK (pad);
1052 * gst_pad_is_blocking:
1053 * @pad: the #GstPad to query
1055 * Checks if the pad is blocking or not. This is a guaranteed state
1056 * of whether the pad is actually blocking on a #GstBuffer or a #GstEvent.
1058 * Returns: TRUE if the pad is blocking.
1065 gst_pad_is_blocking (GstPad * pad)
1067 gboolean result = FALSE;
1069 g_return_val_if_fail (GST_IS_PAD (pad), result);
1071 GST_OBJECT_LOCK (pad);
1073 /* the blocking flag is only valid if the pad is not flushing */
1075 result = GST_OBJECT_FLAG_IS_SET (pad, GST_PAD_BLOCKING) &&
1076 !GST_OBJECT_FLAG_IS_SET (pad, GST_PAD_FLUSHING);
1077 GST_OBJECT_UNLOCK (pad);
1083 * gst_pad_set_activate_function:
1085 * @activate: the #GstPadActivateFunction to set.
1087 * Sets the given activate function for @pad. The activate function will
1088 * dispatch to gst_pad_activate_push() or gst_pad_activate_pull() to perform
1089 * the actual activation. Only makes sense to set on sink pads.
1091 * Call this function if your sink pad can start a pull-based task.
1094 gst_pad_set_activate_function (GstPad * pad, GstPadActivateFunction activate)
1096 g_return_if_fail (GST_IS_PAD (pad));
1098 GST_PAD_ACTIVATEFUNC (pad) = activate;
1099 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "activatefunc set to %s",
1100 GST_DEBUG_FUNCPTR_NAME (activate));
1104 * gst_pad_set_activatepull_function:
1106 * @activatepull: the #GstPadActivateModeFunction to set.
1108 * Sets the given activate_pull function for the pad. An activate_pull function
1109 * prepares the element and any upstream connections for pulling. See XXX
1110 * part-activation.txt for details.
1113 gst_pad_set_activatepull_function (GstPad * pad,
1114 GstPadActivateModeFunction activatepull)
1116 g_return_if_fail (GST_IS_PAD (pad));
1118 GST_PAD_ACTIVATEPULLFUNC (pad) = activatepull;
1119 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "activatepullfunc set to %s",
1120 GST_DEBUG_FUNCPTR_NAME (activatepull));
1124 * gst_pad_set_activatepush_function:
1126 * @activatepush: the #GstPadActivateModeFunction to set.
1128 * Sets the given activate_push function for the pad. An activate_push function
1129 * prepares the element for pushing. See XXX part-activation.txt for details.
1132 gst_pad_set_activatepush_function (GstPad * pad,
1133 GstPadActivateModeFunction activatepush)
1135 g_return_if_fail (GST_IS_PAD (pad));
1137 GST_PAD_ACTIVATEPUSHFUNC (pad) = activatepush;
1138 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "activatepushfunc set to %s",
1139 GST_DEBUG_FUNCPTR_NAME (activatepush));
1143 * gst_pad_set_chain_function:
1144 * @pad: a sink #GstPad.
1145 * @chain: the #GstPadChainFunction to set.
1147 * Sets the given chain function for the pad. The chain function is called to
1148 * process a #GstBuffer input buffer. see #GstPadChainFunction for more details.
1151 gst_pad_set_chain_function (GstPad * pad, GstPadChainFunction chain)
1153 g_return_if_fail (GST_IS_PAD (pad));
1154 g_return_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SINK);
1156 GST_PAD_CHAINFUNC (pad) = chain;
1157 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "chainfunc set to %s",
1158 GST_DEBUG_FUNCPTR_NAME (chain));
1162 * gst_pad_set_getrange_function:
1163 * @pad: a source #GstPad.
1164 * @get: the #GstPadGetRangeFunction to set.
1166 * Sets the given getrange function for the pad. The getrange function is called to
1167 * produce a new #GstBuffer to start the processing pipeline. see
1168 * #GstPadGetRangeFunction for a description of the getrange function.
1171 gst_pad_set_getrange_function (GstPad * pad, GstPadGetRangeFunction get)
1173 g_return_if_fail (GST_IS_PAD (pad));
1174 g_return_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SRC);
1176 GST_PAD_GETRANGEFUNC (pad) = get;
1178 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "getrangefunc set to %s",
1179 GST_DEBUG_FUNCPTR_NAME (get));
1183 * gst_pad_set_checkgetrange_function:
1184 * @pad: a source #GstPad.
1185 * @check: the #GstPadCheckGetRangeFunction to set.
1187 * Sets the given checkgetrange function for the pad. Implement this function on
1188 * a pad if you dynamically support getrange based scheduling on the pad.
1191 gst_pad_set_checkgetrange_function (GstPad * pad,
1192 GstPadCheckGetRangeFunction check)
1194 g_return_if_fail (GST_IS_PAD (pad));
1195 g_return_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SRC);
1197 GST_PAD_CHECKGETRANGEFUNC (pad) = check;
1199 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "checkgetrangefunc set to %s",
1200 GST_DEBUG_FUNCPTR_NAME (check));
1204 * gst_pad_set_event_function:
1205 * @pad: a source #GstPad.
1206 * @event: the #GstPadEventFunction to set.
1208 * Sets the given event handler for the pad.
1211 gst_pad_set_event_function (GstPad * pad, GstPadEventFunction event)
1213 g_return_if_fail (GST_IS_PAD (pad));
1215 GST_PAD_EVENTFUNC (pad) = event;
1217 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "eventfunc for set to %s",
1218 GST_DEBUG_FUNCPTR_NAME (event));
1222 * gst_pad_set_query_function:
1223 * @pad: a #GstPad of either direction.
1224 * @query: the #GstPadQueryFunction to set.
1226 * Set the given query function for the pad.
1229 gst_pad_set_query_function (GstPad * pad, GstPadQueryFunction query)
1231 g_return_if_fail (GST_IS_PAD (pad));
1233 GST_PAD_QUERYFUNC (pad) = query;
1235 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "queryfunc set to %s",
1236 GST_DEBUG_FUNCPTR_NAME (query));
1240 * gst_pad_set_query_type_function:
1241 * @pad: a #GstPad of either direction.
1242 * @type_func: the #GstPadQueryTypeFunction to set.
1244 * Set the given query type function for the pad.
1247 gst_pad_set_query_type_function (GstPad * pad,
1248 GstPadQueryTypeFunction type_func)
1250 g_return_if_fail (GST_IS_PAD (pad));
1252 GST_PAD_QUERYTYPEFUNC (pad) = type_func;
1254 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "querytypefunc set to %s",
1255 GST_DEBUG_FUNCPTR_NAME (type_func));
1259 * gst_pad_get_query_types:
1262 * Get an array of supported queries that can be performed
1265 * Returns: a zero-terminated array of #GstQueryType.
1267 const GstQueryType *
1268 gst_pad_get_query_types (GstPad * pad)
1270 GstPadQueryTypeFunction func;
1272 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
1274 if (G_UNLIKELY ((func = GST_PAD_QUERYTYPEFUNC (pad)) == NULL))
1286 gst_pad_get_query_types_dispatcher (GstPad * pad, const GstQueryType ** data)
1288 *data = gst_pad_get_query_types (pad);
1294 * gst_pad_get_query_types_default:
1297 * Invoke the default dispatcher for the query types on
1300 * Returns: an zero-terminated array of #GstQueryType, or NULL if none of the
1301 * internally-linked pads has a query types function.
1303 const GstQueryType *
1304 gst_pad_get_query_types_default (GstPad * pad)
1306 GstQueryType *result = NULL;
1308 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
1310 gst_pad_dispatcher (pad, (GstPadDispatcherFunction)
1311 gst_pad_get_query_types_dispatcher, &result);
1317 * gst_pad_set_internal_link_function:
1318 * @pad: a #GstPad of either direction.
1319 * @intlink: the #GstPadIntLinkFunction to set.
1321 * Sets the given internal link function for the pad.
1324 gst_pad_set_internal_link_function (GstPad * pad, GstPadIntLinkFunction intlink)
1326 g_return_if_fail (GST_IS_PAD (pad));
1328 GST_PAD_INTLINKFUNC (pad) = intlink;
1329 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "internal link set to %s",
1330 GST_DEBUG_FUNCPTR_NAME (intlink));
1334 * gst_pad_set_link_function:
1336 * @link: the #GstPadLinkFunction to set.
1338 * Sets the given link function for the pad. It will be called when
1339 * the pad is linked with another pad.
1341 * The return value #GST_PAD_LINK_OK should be used when the connection can be
1344 * The return value #GST_PAD_LINK_REFUSED should be used when the connection
1345 * cannot be made for some reason.
1347 * If @link is installed on a source pad, it should call the #GstPadLinkFunction
1348 * of the peer sink pad, if present.
1351 gst_pad_set_link_function (GstPad * pad, GstPadLinkFunction link)
1353 g_return_if_fail (GST_IS_PAD (pad));
1355 GST_PAD_LINKFUNC (pad) = link;
1356 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "linkfunc set to %s",
1357 GST_DEBUG_FUNCPTR_NAME (link));
1361 * gst_pad_set_unlink_function:
1363 * @unlink: the #GstPadUnlinkFunction to set.
1365 * Sets the given unlink function for the pad. It will be called
1366 * when the pad is unlinked.
1369 gst_pad_set_unlink_function (GstPad * pad, GstPadUnlinkFunction unlink)
1371 g_return_if_fail (GST_IS_PAD (pad));
1373 GST_PAD_UNLINKFUNC (pad) = unlink;
1374 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "unlinkfunc set to %s",
1375 GST_DEBUG_FUNCPTR_NAME (unlink));
1379 * gst_pad_set_getcaps_function:
1381 * @getcaps: the #GstPadGetCapsFunction to set.
1383 * Sets the given getcaps function for the pad. @getcaps should return the
1384 * allowable caps for a pad in the context of the element's state, its link to
1385 * other elements, and the devices or files it has opened. These caps must be a
1386 * subset of the pad template caps. In the NULL state with no links, @getcaps
1387 * should ideally return the same caps as the pad template. In rare
1388 * circumstances, an object property can affect the caps returned by @getcaps,
1389 * but this is discouraged.
1391 * You do not need to call this function if @pad's allowed caps are always the
1392 * same as the pad template caps. This can only be true if the padtemplate
1393 * has fixed simple caps.
1395 * For most filters, the caps returned by @getcaps is directly affected by the
1396 * allowed caps on other pads. For demuxers and decoders, the caps returned by
1397 * the srcpad's getcaps function is directly related to the stream data. Again,
1398 * @getcaps should return the most specific caps it reasonably can, since this
1399 * helps with autoplugging.
1401 * Note that the return value from @getcaps is owned by the caller, so the caller
1402 * should unref the caps after usage.
1405 gst_pad_set_getcaps_function (GstPad * pad, GstPadGetCapsFunction getcaps)
1407 g_return_if_fail (GST_IS_PAD (pad));
1409 GST_PAD_GETCAPSFUNC (pad) = getcaps;
1410 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "getcapsfunc set to %s",
1411 GST_DEBUG_FUNCPTR_NAME (getcaps));
1415 * gst_pad_set_acceptcaps_function:
1417 * @acceptcaps: the #GstPadAcceptCapsFunction to set.
1419 * Sets the given acceptcaps function for the pad. The acceptcaps function
1420 * will be called to check if the pad can accept the given caps. Setting the
1421 * acceptcaps function to NULL restores the default behaviour of allowing
1422 * any caps that matches the caps from gst_pad_get_caps.
1425 gst_pad_set_acceptcaps_function (GstPad * pad,
1426 GstPadAcceptCapsFunction acceptcaps)
1428 g_return_if_fail (GST_IS_PAD (pad));
1430 GST_PAD_ACCEPTCAPSFUNC (pad) = acceptcaps;
1431 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "acceptcapsfunc set to %s",
1432 GST_DEBUG_FUNCPTR_NAME (acceptcaps));
1436 * gst_pad_set_fixatecaps_function:
1438 * @fixatecaps: the #GstPadFixateCapsFunction to set.
1440 * Sets the given fixatecaps function for the pad. The fixatecaps function
1441 * will be called whenever the default values for a GstCaps needs to be
1445 gst_pad_set_fixatecaps_function (GstPad * pad,
1446 GstPadFixateCapsFunction fixatecaps)
1448 g_return_if_fail (GST_IS_PAD (pad));
1450 GST_PAD_FIXATECAPSFUNC (pad) = fixatecaps;
1451 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "fixatecapsfunc set to %s",
1452 GST_DEBUG_FUNCPTR_NAME (fixatecaps));
1456 * gst_pad_set_setcaps_function:
1458 * @setcaps: the #GstPadSetCapsFunction to set.
1460 * Sets the given setcaps function for the pad. The setcaps function
1461 * will be called whenever a buffer with a new media type is pushed or
1462 * pulled from the pad. The pad/element needs to update its internal
1463 * structures to process the new media type. If this new type is not
1464 * acceptable, the setcaps function should return FALSE.
1467 gst_pad_set_setcaps_function (GstPad * pad, GstPadSetCapsFunction setcaps)
1469 g_return_if_fail (GST_IS_PAD (pad));
1471 GST_PAD_SETCAPSFUNC (pad) = setcaps;
1472 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "setcapsfunc set to %s",
1473 GST_DEBUG_FUNCPTR_NAME (setcaps));
1477 * gst_pad_set_bufferalloc_function:
1478 * @pad: a sink #GstPad.
1479 * @bufalloc: the #GstPadBufferAllocFunction to set.
1481 * Sets the given bufferalloc function for the pad. Note that the
1482 * bufferalloc function can only be set on sinkpads.
1485 gst_pad_set_bufferalloc_function (GstPad * pad,
1486 GstPadBufferAllocFunction bufalloc)
1488 g_return_if_fail (GST_IS_PAD (pad));
1489 g_return_if_fail (GST_PAD_IS_SINK (pad));
1491 GST_PAD_BUFFERALLOCFUNC (pad) = bufalloc;
1492 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "bufferallocfunc set to %s",
1493 GST_DEBUG_FUNCPTR_NAME (bufalloc));
1498 * @srcpad: the source #GstPad to unlink.
1499 * @sinkpad: the sink #GstPad to unlink.
1501 * Unlinks the source pad from the sink pad. Will emit the "unlinked" signal on
1504 * Returns: TRUE if the pads were unlinked. This function returns FALSE if
1505 * the pads were not linked together.
1510 gst_pad_unlink (GstPad * srcpad, GstPad * sinkpad)
1512 g_return_val_if_fail (GST_IS_PAD (srcpad), FALSE);
1513 g_return_val_if_fail (GST_IS_PAD (sinkpad), FALSE);
1515 GST_CAT_INFO (GST_CAT_ELEMENT_PADS, "unlinking %s:%s(%p) and %s:%s(%p)",
1516 GST_DEBUG_PAD_NAME (srcpad), srcpad,
1517 GST_DEBUG_PAD_NAME (sinkpad), sinkpad);
1519 GST_OBJECT_LOCK (srcpad);
1521 if (G_UNLIKELY (GST_PAD_DIRECTION (srcpad) != GST_PAD_SRC))
1524 GST_OBJECT_LOCK (sinkpad);
1526 if (G_UNLIKELY (GST_PAD_DIRECTION (sinkpad) != GST_PAD_SINK))
1529 if (G_UNLIKELY (GST_PAD_PEER (srcpad) != sinkpad))
1530 goto not_linked_together;
1532 if (GST_PAD_UNLINKFUNC (srcpad)) {
1533 GST_PAD_UNLINKFUNC (srcpad) (srcpad);
1535 if (GST_PAD_UNLINKFUNC (sinkpad)) {
1536 GST_PAD_UNLINKFUNC (sinkpad) (sinkpad);
1539 /* first clear peers */
1540 GST_PAD_PEER (srcpad) = NULL;
1541 GST_PAD_PEER (sinkpad) = NULL;
1543 GST_OBJECT_UNLOCK (sinkpad);
1544 GST_OBJECT_UNLOCK (srcpad);
1546 /* fire off a signal to each of the pads telling them
1547 * that they've been unlinked */
1548 g_signal_emit (G_OBJECT (srcpad), gst_pad_signals[PAD_UNLINKED], 0, sinkpad);
1549 g_signal_emit (G_OBJECT (sinkpad), gst_pad_signals[PAD_UNLINKED], 0, srcpad);
1551 GST_CAT_INFO (GST_CAT_ELEMENT_PADS, "unlinked %s:%s and %s:%s",
1552 GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (sinkpad));
1558 g_critical ("pad %s is not a source pad", GST_PAD_NAME (srcpad));
1559 GST_OBJECT_UNLOCK (srcpad);
1564 g_critical ("pad %s is not a sink pad", GST_PAD_NAME (sinkpad));
1565 GST_OBJECT_UNLOCK (sinkpad);
1566 GST_OBJECT_UNLOCK (srcpad);
1569 not_linked_together:
1571 /* we do not emit a warning in this case because unlinking cannot
1572 * be made MT safe.*/
1573 GST_OBJECT_UNLOCK (sinkpad);
1574 GST_OBJECT_UNLOCK (srcpad);
1580 * gst_pad_is_linked:
1581 * @pad: pad to check
1583 * Checks if a @pad is linked to another pad or not.
1585 * Returns: TRUE if the pad is linked, FALSE otherwise.
1590 gst_pad_is_linked (GstPad * pad)
1594 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
1596 GST_OBJECT_LOCK (pad);
1597 result = (GST_PAD_PEER (pad) != NULL);
1598 GST_OBJECT_UNLOCK (pad);
1603 /* get the caps from both pads and see if the intersection
1606 * This function should be called with the pad LOCK on both
1610 gst_pad_link_check_compatible_unlocked (GstPad * src, GstPad * sink)
1616 srccaps = gst_pad_get_caps_unlocked (src);
1617 sinkcaps = gst_pad_get_caps_unlocked (sink);
1619 GST_CAT_DEBUG (GST_CAT_CAPS, "src caps %" GST_PTR_FORMAT, srccaps);
1620 GST_CAT_DEBUG (GST_CAT_CAPS, "sink caps %" GST_PTR_FORMAT, sinkcaps);
1622 /* if we have caps on both pads we can check the intersection. If one
1623 * of the caps is NULL, we return TRUE. */
1624 if (srccaps == NULL || sinkcaps == NULL)
1627 icaps = gst_caps_intersect (srccaps, sinkcaps);
1628 gst_caps_unref (srccaps);
1629 gst_caps_unref (sinkcaps);
1634 GST_CAT_DEBUG (GST_CAT_CAPS,
1635 "intersection caps %p %" GST_PTR_FORMAT, icaps, icaps);
1637 if (gst_caps_is_empty (icaps))
1640 gst_caps_unref (icaps);
1645 /* incompatible cases */
1648 GST_CAT_DEBUG (GST_CAT_CAPS, "intersection gave NULL");
1653 GST_CAT_DEBUG (GST_CAT_CAPS, "intersection is EMPTY");
1654 gst_caps_unref (icaps);
1659 /* check if the grandparents of both pads are the same.
1660 * This check is required so that we don't try to link
1661 * pads from elements in different bins without ghostpads.
1663 * The LOCK should be held on both pads
1666 gst_pad_link_check_hierarchy (GstPad * src, GstPad * sink)
1668 GstObject *psrc, *psink;
1669 gboolean res = TRUE;
1671 psrc = GST_OBJECT_PARENT (src);
1672 psink = GST_OBJECT_PARENT (sink);
1674 /* if one of the pads has no parent, we allow the link */
1675 if (psrc && psink) {
1676 /* if the parents are the same, we have a loop */
1677 if (G_UNLIKELY (psrc == psink))
1680 /* if they both have a parent, we check the grandparents */
1681 psrc = gst_object_get_parent (psrc);
1682 psink = gst_object_get_parent (psink);
1684 if (G_UNLIKELY (psrc != psink)) {
1685 /* if they have grandparents but they are not the same */
1686 GST_CAT_DEBUG (GST_CAT_CAPS,
1687 "pads have different grandparents %" GST_PTR_FORMAT " and %"
1688 GST_PTR_FORMAT, psrc, psink);
1692 gst_object_unref (psrc);
1694 gst_object_unref (psink);
1702 GST_CAT_DEBUG (GST_CAT_CAPS, "pads have same parent %" GST_PTR_FORMAT,
1709 /* FIXME leftover from an attempt at refactoring... */
1710 /* call with the two pads unlocked, when this function returns GST_PAD_LINK_OK,
1711 * the two pads will be locked in the srcpad, sinkpad order. */
1712 static GstPadLinkReturn
1713 gst_pad_link_prepare (GstPad * srcpad, GstPad * sinkpad)
1715 /* generic checks */
1716 g_return_val_if_fail (GST_IS_PAD (srcpad), GST_PAD_LINK_REFUSED);
1717 g_return_val_if_fail (GST_IS_PAD (sinkpad), GST_PAD_LINK_REFUSED);
1719 GST_CAT_INFO (GST_CAT_PADS, "trying to link %s:%s and %s:%s",
1720 GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (sinkpad));
1722 GST_OBJECT_LOCK (srcpad);
1724 if (G_UNLIKELY (GST_PAD_DIRECTION (srcpad) != GST_PAD_SRC))
1727 if (G_UNLIKELY (GST_PAD_PEER (srcpad) != NULL))
1728 goto src_was_linked;
1730 GST_OBJECT_LOCK (sinkpad);
1732 if (G_UNLIKELY (GST_PAD_DIRECTION (sinkpad) != GST_PAD_SINK))
1735 if (G_UNLIKELY (GST_PAD_PEER (sinkpad) != NULL))
1736 goto sink_was_linked;
1738 /* check hierarchy, pads can only be linked if the grandparents
1740 if (!gst_pad_link_check_hierarchy (srcpad, sinkpad))
1741 goto wrong_hierarchy;
1743 /* check pad caps for non-empty intersection */
1744 if (!gst_pad_link_check_compatible_unlocked (srcpad, sinkpad))
1747 /* FIXME check pad scheduling for non-empty intersection */
1749 return GST_PAD_LINK_OK;
1753 g_critical ("pad %s is not a source pad", GST_PAD_NAME (srcpad));
1754 GST_OBJECT_UNLOCK (srcpad);
1755 return GST_PAD_LINK_WRONG_DIRECTION;
1759 GST_CAT_INFO (GST_CAT_PADS, "src %s:%s was already linked to %s:%s",
1760 GST_DEBUG_PAD_NAME (srcpad),
1761 GST_DEBUG_PAD_NAME (GST_PAD_PEER (srcpad)));
1762 /* we do not emit a warning in this case because unlinking cannot
1763 * be made MT safe.*/
1764 GST_OBJECT_UNLOCK (srcpad);
1765 return GST_PAD_LINK_WAS_LINKED;
1769 g_critical ("pad %s is not a sink pad", GST_PAD_NAME (sinkpad));
1770 GST_OBJECT_UNLOCK (sinkpad);
1771 GST_OBJECT_UNLOCK (srcpad);
1772 return GST_PAD_LINK_WRONG_DIRECTION;
1776 GST_CAT_INFO (GST_CAT_PADS, "sink %s:%s was already linked to %s:%s",
1777 GST_DEBUG_PAD_NAME (sinkpad),
1778 GST_DEBUG_PAD_NAME (GST_PAD_PEER (sinkpad)));
1779 /* we do not emit a warning in this case because unlinking cannot
1780 * be made MT safe.*/
1781 GST_OBJECT_UNLOCK (sinkpad);
1782 GST_OBJECT_UNLOCK (srcpad);
1783 return GST_PAD_LINK_WAS_LINKED;
1787 GST_CAT_INFO (GST_CAT_PADS, "pads have wrong hierarchy");
1788 GST_OBJECT_UNLOCK (sinkpad);
1789 GST_OBJECT_UNLOCK (srcpad);
1790 return GST_PAD_LINK_WRONG_HIERARCHY;
1794 GST_CAT_INFO (GST_CAT_PADS, "caps are incompatible");
1795 GST_OBJECT_UNLOCK (sinkpad);
1796 GST_OBJECT_UNLOCK (srcpad);
1797 return GST_PAD_LINK_NOFORMAT;
1803 * @srcpad: the source #GstPad to link.
1804 * @sinkpad: the sink #GstPad to link.
1806 * Links the source pad and the sink pad.
1808 * Returns: A result code indicating if the connection worked or
1814 gst_pad_link (GstPad * srcpad, GstPad * sinkpad)
1816 GstPadLinkReturn result;
1818 /* prepare will also lock the two pads */
1819 result = gst_pad_link_prepare (srcpad, sinkpad);
1821 if (result != GST_PAD_LINK_OK)
1822 goto prepare_failed;
1824 /* must set peers before calling the link function */
1825 GST_PAD_PEER (srcpad) = sinkpad;
1826 GST_PAD_PEER (sinkpad) = srcpad;
1828 GST_OBJECT_UNLOCK (sinkpad);
1829 GST_OBJECT_UNLOCK (srcpad);
1831 /* FIXME released the locks here, concurrent thread might link
1832 * something else. */
1833 if (GST_PAD_LINKFUNC (srcpad)) {
1834 /* this one will call the peer link function */
1835 result = GST_PAD_LINKFUNC (srcpad) (srcpad, sinkpad);
1836 } else if (GST_PAD_LINKFUNC (sinkpad)) {
1837 /* if no source link function, we need to call the sink link
1838 * function ourselves. */
1839 result = GST_PAD_LINKFUNC (sinkpad) (sinkpad, srcpad);
1841 result = GST_PAD_LINK_OK;
1844 GST_OBJECT_LOCK (srcpad);
1845 GST_OBJECT_LOCK (sinkpad);
1847 if (result == GST_PAD_LINK_OK) {
1848 GST_OBJECT_UNLOCK (sinkpad);
1849 GST_OBJECT_UNLOCK (srcpad);
1851 /* fire off a signal to each of the pads telling them
1852 * that they've been linked */
1853 g_signal_emit (G_OBJECT (srcpad), gst_pad_signals[PAD_LINKED], 0, sinkpad);
1854 g_signal_emit (G_OBJECT (sinkpad), gst_pad_signals[PAD_LINKED], 0, srcpad);
1856 GST_CAT_INFO (GST_CAT_PADS, "linked %s:%s and %s:%s, successful",
1857 GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (sinkpad));
1859 GST_CAT_INFO (GST_CAT_PADS, "link between %s:%s and %s:%s failed",
1860 GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (sinkpad));
1862 GST_PAD_PEER (srcpad) = NULL;
1863 GST_PAD_PEER (sinkpad) = NULL;
1865 GST_OBJECT_UNLOCK (sinkpad);
1866 GST_OBJECT_UNLOCK (srcpad);
1877 gst_pad_set_pad_template (GstPad * pad, GstPadTemplate * templ)
1879 GstPadTemplate **template_p;
1881 /* this function would need checks if it weren't static */
1883 GST_OBJECT_LOCK (pad);
1884 template_p = &pad->padtemplate;
1885 gst_object_replace ((GstObject **) template_p, (GstObject *) templ);
1886 GST_OBJECT_UNLOCK (pad);
1889 gst_pad_template_pad_created (templ, pad);
1893 * gst_pad_get_pad_template:
1896 * Gets the template for @pad.
1898 * Returns: the #GstPadTemplate from which this pad was instantiated, or %NULL
1899 * if this pad has no template.
1901 * FIXME: currently returns an unrefcounted padtemplate.
1904 gst_pad_get_pad_template (GstPad * pad)
1906 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
1908 return GST_PAD_PAD_TEMPLATE (pad);
1912 /* should be called with the pad LOCK held */
1913 /* refs the caps, so caller is responsible for getting it unreffed */
1915 gst_pad_get_caps_unlocked (GstPad * pad)
1917 GstCaps *result = NULL;
1919 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "get pad caps");
1921 if (GST_PAD_GETCAPSFUNC (pad)) {
1922 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
1923 "dispatching to pad getcaps function");
1925 GST_OBJECT_FLAG_SET (pad, GST_PAD_IN_GETCAPS);
1926 GST_OBJECT_UNLOCK (pad);
1927 result = GST_PAD_GETCAPSFUNC (pad) (pad);
1928 GST_OBJECT_LOCK (pad);
1929 GST_OBJECT_FLAG_UNSET (pad, GST_PAD_IN_GETCAPS);
1931 if (result == NULL) {
1932 g_critical ("pad %s:%s returned NULL caps from getcaps function",
1933 GST_DEBUG_PAD_NAME (pad));
1935 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
1936 "pad getcaps returned %" GST_PTR_FORMAT, result);
1937 #ifndef G_DISABLE_ASSERT
1938 /* check that the returned caps are a real subset of the template caps */
1939 if (GST_PAD_PAD_TEMPLATE (pad)) {
1940 const GstCaps *templ_caps =
1941 GST_PAD_TEMPLATE_CAPS (GST_PAD_PAD_TEMPLATE (pad));
1942 if (!gst_caps_is_subset (result, templ_caps)) {
1945 GST_CAT_ERROR_OBJECT (GST_CAT_CAPS, pad,
1946 "pad returned caps %" GST_PTR_FORMAT
1947 " which are not a real subset of its template caps %"
1948 GST_PTR_FORMAT, result, templ_caps);
1950 ("pad %s:%s returned caps that are not a real subset of its template caps",
1951 GST_DEBUG_PAD_NAME (pad));
1952 temp = gst_caps_intersect (templ_caps, result);
1953 gst_caps_unref (result);
1961 if (GST_PAD_PAD_TEMPLATE (pad)) {
1962 GstPadTemplate *templ = GST_PAD_PAD_TEMPLATE (pad);
1964 result = GST_PAD_TEMPLATE_CAPS (templ);
1965 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
1966 "using pad template %p with caps %p %" GST_PTR_FORMAT, templ, result,
1969 result = gst_caps_ref (result);
1972 if (GST_PAD_CAPS (pad)) {
1973 result = GST_PAD_CAPS (pad);
1975 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
1976 "using pad caps %p %" GST_PTR_FORMAT, result, result);
1978 result = gst_caps_ref (result);
1982 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "pad has no caps");
1983 result = gst_caps_new_empty ();
1991 * @pad: a #GstPad to get the capabilities of.
1993 * Gets the capabilities this pad can produce or consume.
1994 * Note that this method doesn't necessarily return the caps set by
1995 * gst_pad_set_caps() - use #GST_PAD_CAPS for that instead.
1996 * gst_pad_get_caps returns all possible caps a pad can operate with, using
1997 * the pad's get_caps function;
1998 * this returns the pad template caps if not explicitly set.
2000 * Returns: a newly allocated copy of the #GstCaps of this pad.
2005 gst_pad_get_caps (GstPad * pad)
2007 GstCaps *result = NULL;
2009 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2011 GST_OBJECT_LOCK (pad);
2013 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "get pad caps");
2015 result = gst_pad_get_caps_unlocked (pad);
2016 GST_OBJECT_UNLOCK (pad);
2022 * gst_pad_peer_get_caps:
2023 * @pad: a #GstPad to get the peer capabilities of.
2025 * Gets the capabilities of the peer connected to this pad.
2027 * Returns: the #GstCaps of the peer pad. This function returns a new caps, so use
2028 * gst_caps_unref to get rid of it. this function returns NULL if there is no
2032 gst_pad_peer_get_caps (GstPad * pad)
2035 GstCaps *result = NULL;
2037 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2039 GST_OBJECT_LOCK (pad);
2041 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "get peer caps");
2043 peerpad = GST_PAD_PEER (pad);
2044 if (G_UNLIKELY (peerpad == NULL))
2047 gst_object_ref (peerpad);
2048 GST_OBJECT_UNLOCK (pad);
2050 result = gst_pad_get_caps (peerpad);
2052 gst_object_unref (peerpad);
2058 GST_OBJECT_UNLOCK (pad);
2064 fixate_value (GValue * dest, const GValue * src)
2066 if (G_VALUE_TYPE (src) == GST_TYPE_INT_RANGE) {
2067 g_value_init (dest, G_TYPE_INT);
2068 g_value_set_int (dest, gst_value_get_int_range_min (src));
2069 } else if (G_VALUE_TYPE (src) == GST_TYPE_DOUBLE_RANGE) {
2070 g_value_init (dest, G_TYPE_DOUBLE);
2071 g_value_set_double (dest, gst_value_get_double_range_min (src));
2072 } else if (G_VALUE_TYPE (src) == GST_TYPE_FRACTION_RANGE) {
2073 gst_value_init_and_copy (dest, gst_value_get_fraction_range_min (src));
2074 } else if (G_VALUE_TYPE (src) == GST_TYPE_LIST) {
2075 GValue temp = { 0 };
2077 gst_value_init_and_copy (&temp, gst_value_list_get_value (src, 0));
2078 if (!fixate_value (dest, &temp))
2079 gst_value_init_and_copy (dest, &temp);
2080 g_value_unset (&temp);
2081 } else if (G_VALUE_TYPE (src) == GST_TYPE_ARRAY) {
2082 gboolean res = FALSE;
2085 g_value_init (dest, GST_TYPE_ARRAY);
2086 for (n = 0; n < gst_value_array_get_size (src); n++) {
2088 const GValue *orig_kid = gst_value_array_get_value (src, n);
2090 if (!fixate_value (&kid, orig_kid))
2091 gst_value_init_and_copy (&kid, orig_kid);
2094 gst_value_array_append_value (dest, &kid);
2095 g_value_unset (&kid);
2099 g_value_unset (dest);
2110 gst_pad_default_fixate (GQuark field_id, const GValue * value, gpointer data)
2112 GstStructure *s = data;
2115 if (fixate_value (&v, value)) {
2116 gst_structure_id_set_value (s, field_id, &v);
2124 * gst_pad_fixate_caps:
2125 * @pad: a #GstPad to fixate
2126 * @caps: the #GstCaps to fixate
2128 * Fixate a caps on the given pad. Modifies the caps in place, so you should
2129 * make sure that the caps are actually writable (see gst_caps_make_writable()).
2132 gst_pad_fixate_caps (GstPad * pad, GstCaps * caps)
2134 GstPadFixateCapsFunction fixatefunc;
2137 g_return_if_fail (GST_IS_PAD (pad));
2138 g_return_if_fail (caps != NULL);
2140 if (gst_caps_is_fixed (caps))
2143 fixatefunc = GST_PAD_FIXATECAPSFUNC (pad);
2145 fixatefunc (pad, caps);
2148 /* default fixation */
2149 for (n = 0; n < gst_caps_get_size (caps); n++) {
2150 GstStructure *s = gst_caps_get_structure (caps, n);
2152 gst_structure_foreach (s, gst_pad_default_fixate, s);
2156 /* Default accept caps implementation just checks against
2157 * against the allowed caps for the pad */
2159 gst_pad_acceptcaps_default (GstPad * pad, GstCaps * caps)
2161 /* get the caps and see if it intersects to something
2165 gboolean result = FALSE;
2167 allowed = gst_pad_get_caps (pad);
2169 intersect = gst_caps_intersect (allowed, caps);
2171 result = !gst_caps_is_empty (intersect);
2173 gst_caps_unref (allowed);
2174 gst_caps_unref (intersect);
2181 * gst_pad_accept_caps:
2182 * @pad: a #GstPad to check
2183 * @caps: a #GstCaps to check on the pad
2185 * Check if the given pad accepts the caps.
2187 * Returns: TRUE if the pad can accept the caps.
2190 gst_pad_accept_caps (GstPad * pad, GstCaps * caps)
2193 GstPadAcceptCapsFunction acceptfunc;
2194 GstCaps *existing = NULL;
2196 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2198 /* any pad can be unnegotiated */
2202 /* lock for checking the existing caps */
2203 GST_OBJECT_LOCK (pad);
2204 acceptfunc = GST_PAD_ACCEPTCAPSFUNC (pad);
2205 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "accept caps of %p", caps);
2206 /* The current caps on a pad are trivially acceptable */
2207 if (G_LIKELY ((existing = GST_PAD_CAPS (pad)))) {
2208 if (caps == existing || gst_caps_is_equal (caps, existing))
2211 GST_OBJECT_UNLOCK (pad);
2213 if (G_LIKELY (acceptfunc)) {
2214 /* we can call the function */
2215 result = acceptfunc (pad, caps);
2217 /* Only null if the element explicitly unset it */
2218 result = gst_pad_acceptcaps_default (pad, caps);
2224 GST_OBJECT_UNLOCK (pad);
2230 * gst_pad_peer_accept_caps:
2231 * @pad: a #GstPad to check the peer of
2232 * @caps: a #GstCaps to check on the pad
2234 * Check if the peer of @pad accepts @caps. If @pad has no peer, this function
2237 * Returns: TRUE if the peer of @pad can accept the caps or @pad has no peer.
2240 gst_pad_peer_accept_caps (GstPad * pad, GstCaps * caps)
2245 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2247 GST_OBJECT_LOCK (pad);
2249 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "peer accept caps of (%p)", pad);
2251 peerpad = GST_PAD_PEER (pad);
2252 if (G_UNLIKELY (peerpad == NULL))
2255 result = gst_pad_accept_caps (peerpad, caps);
2256 GST_OBJECT_UNLOCK (pad);
2262 GST_OBJECT_UNLOCK (pad);
2269 * @pad: a #GstPad to set the capabilities of.
2270 * @caps: a #GstCaps to set.
2272 * Sets the capabilities of this pad. The caps must be fixed. Any previous
2273 * caps on the pad will be unreffed. This function refs the caps so you should
2274 * unref if as soon as you don't need it anymore.
2275 * It is possible to set NULL caps, which will make the pad unnegotiated
2278 * Returns: TRUE if the caps could be set. FALSE if the caps were not fixed
2279 * or bad parameters were provided to this function.
2284 gst_pad_set_caps (GstPad * pad, GstCaps * caps)
2286 GstPadSetCapsFunction setcaps;
2289 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2290 g_return_val_if_fail (caps == NULL || gst_caps_is_fixed (caps), FALSE);
2292 GST_OBJECT_LOCK (pad);
2293 existing = GST_PAD_CAPS (pad);
2294 if (existing == caps)
2297 if (gst_caps_is_equal (caps, existing))
2298 goto setting_same_caps;
2300 setcaps = GST_PAD_SETCAPSFUNC (pad);
2302 /* call setcaps function to configure the pad only if the
2303 * caps is not NULL */
2304 if (setcaps != NULL && caps) {
2305 if (!GST_PAD_IS_IN_SETCAPS (pad)) {
2306 GST_OBJECT_FLAG_SET (pad, GST_PAD_IN_SETCAPS);
2307 GST_OBJECT_UNLOCK (pad);
2308 if (!setcaps (pad, caps))
2310 GST_OBJECT_LOCK (pad);
2311 GST_OBJECT_FLAG_UNSET (pad, GST_PAD_IN_SETCAPS);
2313 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "pad was dispatching");
2317 gst_caps_replace (&GST_PAD_CAPS (pad), caps);
2318 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "caps %" GST_PTR_FORMAT, caps);
2319 GST_OBJECT_UNLOCK (pad);
2321 g_object_notify (G_OBJECT (pad), "caps");
2327 GST_OBJECT_UNLOCK (pad);
2332 gst_caps_replace (&GST_PAD_CAPS (pad), caps);
2333 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
2334 "caps %" GST_PTR_FORMAT " same as existing, updating ptr only", caps);
2335 GST_OBJECT_UNLOCK (pad);
2342 GST_OBJECT_LOCK (pad);
2343 GST_OBJECT_FLAG_UNSET (pad, GST_PAD_IN_SETCAPS);
2344 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
2345 "caps %" GST_PTR_FORMAT " could not be set", caps);
2346 GST_OBJECT_UNLOCK (pad);
2353 gst_pad_configure_sink (GstPad * pad, GstCaps * caps)
2355 GstPadSetCapsFunction setcaps;
2358 setcaps = GST_PAD_SETCAPSFUNC (pad);
2360 /* See if pad accepts the caps - only needed if
2361 * no setcaps function */
2362 if (setcaps == NULL)
2363 if (!gst_pad_accept_caps (pad, caps))
2366 /* set caps on pad if call succeeds */
2367 res = gst_pad_set_caps (pad, caps);
2368 /* no need to unref the caps here, set_caps takes a ref and
2369 * our ref goes away when we leave this function. */
2375 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
2376 "caps %" GST_PTR_FORMAT " not accepted", caps);
2381 /* returns TRUE if the src pad could be configured to accept the given caps */
2383 gst_pad_configure_src (GstPad * pad, GstCaps * caps, gboolean dosetcaps)
2385 GstPadSetCapsFunction setcaps;
2388 setcaps = GST_PAD_SETCAPSFUNC (pad);
2390 /* See if pad accepts the caps - only needed if
2391 * no setcaps function */
2392 if (setcaps == NULL)
2393 if (!gst_pad_accept_caps (pad, caps))
2397 res = gst_pad_set_caps (pad, caps);
2405 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
2406 "caps %" GST_PTR_FORMAT " not accepted", caps);
2412 * gst_pad_get_pad_template_caps:
2413 * @pad: a #GstPad to get the template capabilities from.
2415 * Gets the capabilities for @pad's template.
2417 * Returns: the #GstCaps of this pad template. If you intend to keep a reference
2418 * on the caps, make a copy (see gst_caps_copy ()).
2421 gst_pad_get_pad_template_caps (GstPad * pad)
2423 static GstStaticCaps anycaps = GST_STATIC_CAPS ("ANY");
2425 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2427 if (GST_PAD_PAD_TEMPLATE (pad))
2428 return GST_PAD_TEMPLATE_CAPS (GST_PAD_PAD_TEMPLATE (pad));
2430 return gst_static_caps_get (&anycaps);
2436 * @pad: a #GstPad to get the peer of.
2438 * Gets the peer of @pad. This function refs the peer pad so
2439 * you need to unref it after use.
2441 * Returns: the peer #GstPad. Unref after usage.
2446 gst_pad_get_peer (GstPad * pad)
2450 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2452 GST_OBJECT_LOCK (pad);
2453 result = GST_PAD_PEER (pad);
2455 gst_object_ref (result);
2456 GST_OBJECT_UNLOCK (pad);
2462 * gst_pad_get_allowed_caps:
2463 * @srcpad: a #GstPad, it must a a source pad.
2465 * Gets the capabilities of the allowed media types that can flow through
2466 * @srcpad and its peer. The pad must be a source pad.
2467 * The caller must free the resulting caps.
2469 * Returns: the allowed #GstCaps of the pad link. Free the caps when
2470 * you no longer need it. This function returns NULL when the @srcpad has no
2476 gst_pad_get_allowed_caps (GstPad * srcpad)
2483 g_return_val_if_fail (GST_IS_PAD (srcpad), NULL);
2484 g_return_val_if_fail (GST_PAD_IS_SRC (srcpad), NULL);
2486 GST_OBJECT_LOCK (srcpad);
2488 peer = GST_PAD_PEER (srcpad);
2489 if (G_UNLIKELY (peer == NULL))
2492 GST_CAT_DEBUG_OBJECT (GST_CAT_PROPERTIES, srcpad, "getting allowed caps");
2494 gst_object_ref (peer);
2495 GST_OBJECT_UNLOCK (srcpad);
2496 mycaps = gst_pad_get_caps (srcpad);
2498 peercaps = gst_pad_get_caps (peer);
2499 gst_object_unref (peer);
2501 caps = gst_caps_intersect (mycaps, peercaps);
2502 gst_caps_unref (peercaps);
2503 gst_caps_unref (mycaps);
2505 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, srcpad, "allowed caps %" GST_PTR_FORMAT,
2512 GST_CAT_DEBUG_OBJECT (GST_CAT_PROPERTIES, srcpad, "no peer");
2513 GST_OBJECT_UNLOCK (srcpad);
2520 * gst_pad_get_negotiated_caps:
2523 * Gets the capabilities of the media type that currently flows through @pad
2526 * This function can be used on both src and sinkpads. Note that srcpads are
2527 * always negotiated before sinkpads so it is possible that the negotiated caps
2528 * on the srcpad do not match the negotiated caps of the peer.
2530 * Returns: the negotiated #GstCaps of the pad link. Free the caps when
2531 * you no longer need it. This function returns NULL when the @pad has no
2532 * peer or is not negotiated yet.
2537 gst_pad_get_negotiated_caps (GstPad * pad)
2542 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2544 GST_OBJECT_LOCK (pad);
2546 if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
2549 GST_CAT_DEBUG_OBJECT (GST_CAT_PROPERTIES, pad, "getting negotiated caps");
2551 caps = GST_PAD_CAPS (pad);
2553 gst_caps_ref (caps);
2554 GST_OBJECT_UNLOCK (pad);
2556 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "negotiated caps %" GST_PTR_FORMAT,
2563 GST_CAT_DEBUG_OBJECT (GST_CAT_PROPERTIES, pad, "no peer");
2564 GST_OBJECT_UNLOCK (pad);
2570 /* calls the buffer_alloc function on the given pad */
2571 static GstFlowReturn
2572 gst_pad_buffer_alloc_unchecked (GstPad * pad, guint64 offset, gint size,
2573 GstCaps * caps, GstBuffer ** buf)
2576 GstPadBufferAllocFunction bufferallocfunc;
2578 GST_OBJECT_LOCK (pad);
2579 /* when the pad is flushing we cannot give a buffer */
2580 if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad)))
2583 bufferallocfunc = pad->bufferallocfunc;
2585 if (offset == GST_BUFFER_OFFSET_NONE) {
2586 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
2587 "calling bufferallocfunc &%s (@%p) for size %d offset NONE",
2588 GST_DEBUG_FUNCPTR_NAME (bufferallocfunc), bufferallocfunc, size);
2590 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
2591 "calling bufferallocfunc &%s (@%p) of for size %d offset %"
2592 G_GUINT64_FORMAT, GST_DEBUG_FUNCPTR_NAME (bufferallocfunc),
2593 bufferallocfunc, size, offset);
2595 GST_OBJECT_UNLOCK (pad);
2597 /* G_LIKELY for now since most elements don't implement a buffer alloc
2598 * function and there is no default alloc proxy function as this is usually
2600 if (G_LIKELY (bufferallocfunc == NULL))
2603 ret = bufferallocfunc (pad, offset, size, caps, buf);
2604 if (G_UNLIKELY (ret != GST_FLOW_OK))
2606 /* no error, but NULL buffer means fallback to the default */
2607 if (G_UNLIKELY (*buf == NULL))
2610 /* If the buffer alloc function didn't set up the caps like it should,
2612 if (G_UNLIKELY (caps && (GST_BUFFER_CAPS (*buf) == NULL))) {
2613 GST_WARNING_OBJECT (pad,
2614 "Buffer allocation function did not set caps. Setting");
2615 gst_buffer_set_caps (*buf, caps);
2621 /* pad was flushing */
2622 GST_OBJECT_UNLOCK (pad);
2623 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "pad was flushing");
2624 return GST_FLOW_WRONG_STATE;
2628 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
2629 "alloc function returned error (%d) %s", ret, gst_flow_get_name (ret));
2634 /* fallback case, allocate a buffer of our own, add pad caps. */
2635 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "fallback buffer alloc");
2637 *buf = gst_buffer_new_and_alloc (size);
2638 GST_BUFFER_OFFSET (*buf) = offset;
2639 gst_buffer_set_caps (*buf, caps);
2645 static GstFlowReturn
2646 gst_pad_alloc_buffer_full (GstPad * pad, guint64 offset, gint size,
2647 GstCaps * caps, GstBuffer ** buf, gboolean setcaps)
2651 gboolean caps_changed;
2653 g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
2654 g_return_val_if_fail (GST_PAD_IS_SRC (pad), GST_FLOW_ERROR);
2655 g_return_val_if_fail (buf != NULL, GST_FLOW_ERROR);
2657 GST_OBJECT_LOCK (pad);
2658 while (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad)))
2659 if ((ret = handle_pad_block (pad)) != GST_FLOW_OK)
2662 if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
2665 gst_object_ref (peer);
2666 GST_OBJECT_UNLOCK (pad);
2668 ret = gst_pad_buffer_alloc_unchecked (peer, offset, size, caps, buf);
2669 gst_object_unref (peer);
2671 if (G_UNLIKELY (ret != GST_FLOW_OK))
2674 /* FIXME, move capnego this into a base class? */
2675 caps = GST_BUFFER_CAPS (*buf);
2677 /* Lock for checking caps, pretty pointless as the _pad_push() function might
2678 * change it concurrently, one of the problems with automatic caps setting in
2679 * pad_alloc_and_set_caps. Worst case, if does a check too much, but only when
2680 * there is heavy renegotiation going on in both directions. */
2681 GST_OBJECT_LOCK (pad);
2682 caps_changed = caps && caps != GST_PAD_CAPS (pad);
2683 GST_OBJECT_UNLOCK (pad);
2685 /* we got a new datatype on the pad, see if it can handle it */
2686 if (G_UNLIKELY (caps_changed)) {
2687 GST_DEBUG_OBJECT (pad, "caps changed to %p %" GST_PTR_FORMAT, caps, caps);
2688 if (G_UNLIKELY (!gst_pad_configure_src (pad, caps, setcaps)))
2689 goto not_negotiated;
2695 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "pad block stopped by flush");
2696 GST_OBJECT_UNLOCK (pad);
2701 /* pad has no peer */
2702 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
2703 "called bufferallocfunc but had no peer");
2704 GST_OBJECT_UNLOCK (pad);
2705 return GST_FLOW_NOT_LINKED;
2709 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
2710 "alloc function returned error %s", gst_flow_get_name (ret));
2715 gst_buffer_unref (*buf);
2717 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
2718 "alloc function returned unacceptable buffer");
2719 return GST_FLOW_NOT_NEGOTIATED;
2724 * gst_pad_alloc_buffer:
2725 * @pad: a source #GstPad
2726 * @offset: the offset of the new buffer in the stream
2727 * @size: the size of the new buffer
2728 * @caps: the caps of the new buffer
2729 * @buf: a newly allocated buffer
2731 * Allocates a new, empty buffer optimized to push to pad @pad. This
2732 * function only works if @pad is a source pad and has a peer.
2734 * A new, empty #GstBuffer will be put in the @buf argument.
2735 * You need to check the caps of the buffer after performing this
2736 * function and renegotiate to the format if needed.
2738 * Returns: a result code indicating success of the operation. Any
2739 * result code other than #GST_FLOW_OK is an error and @buf should
2741 * An error can occur if the pad is not connected or when the downstream
2742 * peer elements cannot provide an acceptable buffer.
2747 gst_pad_alloc_buffer (GstPad * pad, guint64 offset, gint size, GstCaps * caps,
2750 return gst_pad_alloc_buffer_full (pad, offset, size, caps, buf, FALSE);
2754 * gst_pad_alloc_buffer_and_set_caps:
2755 * @pad: a source #GstPad
2756 * @offset: the offset of the new buffer in the stream
2757 * @size: the size of the new buffer
2758 * @caps: the caps of the new buffer
2759 * @buf: a newly allocated buffer
2761 * In addition to the function gst_pad_alloc_buffer(), this function
2762 * automatically calls gst_pad_set_caps() when the caps of the
2763 * newly allocated buffer are different from the @pad caps.
2765 * Returns: a result code indicating success of the operation. Any
2766 * result code other than #GST_FLOW_OK is an error and @buf should
2768 * An error can occur if the pad is not connected or when the downstream
2769 * peer elements cannot provide an acceptable buffer.
2774 gst_pad_alloc_buffer_and_set_caps (GstPad * pad, guint64 offset, gint size,
2775 GstCaps * caps, GstBuffer ** buf)
2777 return gst_pad_alloc_buffer_full (pad, offset, size, caps, buf, TRUE);
2781 * gst_pad_get_internal_links_default:
2782 * @pad: the #GstPad to get the internal links of.
2784 * Gets a list of pads to which the given pad is linked to
2785 * inside of the parent element.
2786 * This is the default handler, and thus returns a list of all of the
2787 * pads inside the parent element with opposite direction.
2788 * The caller must free this list after use.
2790 * Returns: a newly allocated #GList of pads, or NULL if the pad has no parent.
2795 gst_pad_get_internal_links_default (GstPad * pad)
2800 GstPadDirection direction;
2802 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2804 direction = pad->direction;
2806 parent = GST_PAD_PARENT (pad);
2810 parent_pads = parent->pads;
2812 while (parent_pads) {
2813 GstPad *parent_pad = GST_PAD_CAST (parent_pads->data);
2815 if (parent_pad->direction != direction) {
2816 res = g_list_prepend (res, parent_pad);
2819 parent_pads = g_list_next (parent_pads);
2826 * gst_pad_get_internal_links:
2827 * @pad: the #GstPad to get the internal links of.
2829 * Gets a list of pads to which the given pad is linked to
2830 * inside of the parent element.
2831 * The caller must free this list after use.
2833 * Returns: a newly allocated #GList of pads.
2838 gst_pad_get_internal_links (GstPad * pad)
2842 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2844 if (GST_PAD_INTLINKFUNC (pad))
2845 res = GST_PAD_INTLINKFUNC (pad) (pad);
2852 gst_pad_event_default_dispatch (GstPad * pad, GstEvent * event)
2857 GST_INFO_OBJECT (pad, "Sending event %p to all internally linked pads",
2860 result = (GST_PAD_DIRECTION (pad) == GST_PAD_SINK);
2862 orig = pads = gst_pad_get_internal_links (pad);
2865 GstPad *eventpad = GST_PAD_CAST (pads->data);
2867 pads = g_list_next (pads);
2869 if (GST_PAD_DIRECTION (eventpad) == GST_PAD_SRC) {
2870 /* for each pad we send to, we should ref the event; it's up
2871 * to downstream to unref again when handled. */
2872 GST_LOG_OBJECT (pad, "Reffing and sending event %p (%s) to %s:%s",
2873 event, GST_EVENT_TYPE_NAME (event), GST_DEBUG_PAD_NAME (eventpad));
2874 gst_event_ref (event);
2875 gst_pad_push_event (eventpad, event);
2877 /* we only send the event on one pad, multi-sinkpad elements
2878 * should implement a handler */
2879 GST_LOG_OBJECT (pad, "sending event %p (%s) to one sink pad %s:%s",
2880 event, GST_EVENT_TYPE_NAME (event), GST_DEBUG_PAD_NAME (eventpad));
2881 result = gst_pad_push_event (eventpad, event);
2885 /* we handled the incoming event so we unref once */
2886 GST_LOG_OBJECT (pad, "handled event %p, unreffing", event);
2887 gst_event_unref (event);
2896 * gst_pad_event_default:
2897 * @pad: a #GstPad to call the default event handler on.
2898 * @event: the #GstEvent to handle.
2900 * Invokes the default event handler for the given pad. End-of-stream and
2901 * discontinuity events are handled specially, and then the event is sent to all
2902 * pads internally linked to @pad. Note that if there are many possible sink
2903 * pads that are internally linked to @pad, only one will be sent an event.
2904 * Multi-sinkpad elements should implement custom event handlers.
2906 * Returns: TRUE if the event was sent succesfully.
2909 gst_pad_event_default (GstPad * pad, GstEvent * event)
2911 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2912 g_return_val_if_fail (event != NULL, FALSE);
2914 switch (GST_EVENT_TYPE (event)) {
2917 GST_DEBUG_OBJECT (pad, "pausing task because of eos");
2918 gst_pad_pause_task (pad);
2924 return gst_pad_event_default_dispatch (pad, event);
2928 * gst_pad_dispatcher:
2929 * @pad: a #GstPad to dispatch.
2930 * @dispatch: the #GstDispatcherFunction to call.
2931 * @data: gpointer user data passed to the dispatcher function.
2933 * Invokes the given dispatcher function on all pads that are
2934 * internally linked to the given pad.
2935 * The GstPadDispatcherFunction should return TRUE when no further pads
2936 * need to be processed.
2938 * Returns: TRUE if one of the dispatcher functions returned TRUE.
2941 gst_pad_dispatcher (GstPad * pad, GstPadDispatcherFunction dispatch,
2944 gboolean res = FALSE;
2945 GList *int_pads, *orig;
2947 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2948 g_return_val_if_fail (dispatch != NULL, FALSE);
2950 orig = int_pads = gst_pad_get_internal_links (pad);
2953 GstPad *int_pad = GST_PAD_CAST (int_pads->data);
2954 GstPad *int_peer = GST_PAD_PEER (int_pad);
2957 res = dispatch (int_peer, data);
2961 int_pads = g_list_next (int_pads);
2971 * @pad: a #GstPad to invoke the default query on.
2972 * @query: the #GstQuery to perform.
2974 * Dispatches a query to a pad. The query should have been allocated by the
2975 * caller via one of the type-specific allocation functions in gstquery.h. The
2976 * element is responsible for filling the query with an appropriate response,
2977 * which should then be parsed with a type-specific query parsing function.
2979 * Again, the caller is responsible for both the allocation and deallocation of
2980 * the query structure.
2982 * Returns: TRUE if the query could be performed.
2985 gst_pad_query (GstPad * pad, GstQuery * query)
2987 GstPadQueryFunction func;
2989 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2990 g_return_val_if_fail (GST_IS_QUERY (query), FALSE);
2992 GST_DEBUG_OBJECT (pad, "sending query %p", query);
2994 if ((func = GST_PAD_QUERYFUNC (pad)) == NULL)
2997 return func (pad, query);
3001 GST_DEBUG_OBJECT (pad, "had no query function");
3007 * gst_pad_query_default:
3008 * @pad: a #GstPad to call the default query handler on.
3009 * @query: the #GstQuery to handle.
3011 * Invokes the default query handler for the given pad.
3012 * The query is sent to all pads internally linked to @pad. Note that
3013 * if there are many possible sink pads that are internally linked to
3014 * @pad, only one will be sent the query.
3015 * Multi-sinkpad elements should implement custom query handlers.
3017 * Returns: TRUE if the query was performed succesfully.
3020 gst_pad_query_default (GstPad * pad, GstQuery * query)
3022 switch (GST_QUERY_TYPE (query)) {
3023 case GST_QUERY_POSITION:
3024 case GST_QUERY_SEEKING:
3025 case GST_QUERY_FORMATS:
3026 case GST_QUERY_LATENCY:
3027 case GST_QUERY_JITTER:
3028 case GST_QUERY_RATE:
3029 case GST_QUERY_CONVERT:
3031 return gst_pad_dispatcher
3032 (pad, (GstPadDispatcherFunction) gst_pad_query, query);
3036 #ifndef GST_DISABLE_LOADSAVE
3037 /* FIXME: why isn't this on a GstElement ? */
3039 * gst_pad_load_and_link:
3040 * @self: an #xmlNodePtr to read the description from.
3041 * @parent: the #GstObject element that owns the pad.
3043 * Reads the pad definition from the XML node and links the given pad
3044 * in the element to a pad of an element up in the hierarchy.
3047 gst_pad_load_and_link (xmlNodePtr self, GstObject * parent)
3049 xmlNodePtr field = self->xmlChildrenNode;
3050 GstPad *pad = NULL, *targetpad;
3054 GstObject *grandparent;
3058 if (!strcmp ((char *) field->name, "name")) {
3059 name = (gchar *) xmlNodeGetContent (field);
3060 pad = gst_element_get_pad (GST_ELEMENT (parent), name);
3062 } else if (!strcmp ((char *) field->name, "peer")) {
3063 peer = (gchar *) xmlNodeGetContent (field);
3065 field = field->next;
3067 g_return_if_fail (pad != NULL);
3072 split = g_strsplit (peer, ".", 2);
3074 if (split[0] == NULL || split[1] == NULL) {
3075 GST_CAT_DEBUG_OBJECT (GST_CAT_XML, pad,
3076 "Could not parse peer '%s', leaving unlinked", peer);
3083 g_return_if_fail (split[0] != NULL);
3084 g_return_if_fail (split[1] != NULL);
3086 grandparent = gst_object_get_parent (parent);
3088 if (grandparent && GST_IS_BIN (grandparent)) {
3089 target = gst_bin_get_by_name_recurse_up (GST_BIN (grandparent), split[0]);
3096 targetpad = gst_element_get_pad (target, split[1]);
3098 if (targetpad == NULL)
3101 gst_pad_link (pad, targetpad);
3108 * gst_pad_save_thyself:
3109 * @pad: a #GstPad to save.
3110 * @parent: the parent #xmlNodePtr to save the description in.
3112 * Saves the pad into an xml representation.
3114 * Returns: the #xmlNodePtr representation of the pad.
3117 gst_pad_save_thyself (GstObject * object, xmlNodePtr parent)
3122 g_return_val_if_fail (GST_IS_PAD (object), NULL);
3124 pad = GST_PAD (object);
3126 xmlNewChild (parent, NULL, (xmlChar *) "name",
3127 (xmlChar *) GST_PAD_NAME (pad));
3128 if (GST_PAD_PEER (pad) != NULL) {
3131 peer = GST_PAD_PEER (pad);
3132 /* first check to see if the peer's parent's parent is the same */
3133 /* we just save it off */
3134 content = g_strdup_printf ("%s.%s",
3135 GST_OBJECT_NAME (GST_PAD_PARENT (peer)), GST_PAD_NAME (peer));
3136 xmlNewChild (parent, NULL, (xmlChar *) "peer", (xmlChar *) content);
3139 xmlNewChild (parent, NULL, (xmlChar *) "peer", NULL);
3146 * gst_ghost_pad_save_thyself:
3147 * @pad: a ghost #GstPad to save.
3148 * @parent: the parent #xmlNodePtr to save the description in.
3150 * Saves the ghost pad into an xml representation.
3152 * Returns: the #xmlNodePtr representation of the pad.
3155 gst_ghost_pad_save_thyself (GstPad * pad, xmlNodePtr parent)
3159 g_return_val_if_fail (GST_IS_GHOST_PAD (pad), NULL);
3161 self = xmlNewChild (parent, NULL, (xmlChar *) "ghostpad", NULL);
3162 xmlNewChild (self, NULL, (xmlChar *) "name", (xmlChar *) GST_PAD_NAME (pad));
3163 xmlNewChild (self, NULL, (xmlChar *) "parent",
3164 (xmlChar *) GST_OBJECT_NAME (GST_PAD_PARENT (pad)));
3166 /* FIXME FIXME FIXME! */
3171 #endif /* GST_DISABLE_LOADSAVE */
3174 * should be called with pad OBJECT_LOCK and STREAM_LOCK held.
3175 * GST_PAD_IS_BLOCKED (pad) == TRUE when this function is
3178 * This function perform the pad blocking when an event, buffer push
3179 * or buffer_alloc is performed on a _SRC_ pad. It blocks the
3180 * streaming thread after informing the pad has been blocked.
3182 * An application can with this method wait and block any streaming
3183 * thread and perform operations such as seeking or linking.
3185 * Two methods are available for notifying the application of the
3187 * - the callback method, which happens in the STREAMING thread with
3188 * the STREAM_LOCK held. With this method, the most usefull way of
3189 * dealing with the callback is to post a message to the main thread
3190 * where the pad block can then be handled outside of the streaming
3191 * thread. With the last method one can perform all operations such
3192 * as doing a state change, linking, unblocking, seeking etc on the
3194 * - the GCond signal method, which makes any thread unblock when
3195 * the pad block happens.
3197 * During the actual blocking state, the GST_PAD_BLOCKING flag is set.
3198 * The GST_PAD_BLOCKING flag is unset when the GST_PAD_FLUSHING flag is
3199 * unset. This is to know whether the pad was blocking when GST_PAD_FLUSHING
3204 static GstFlowReturn
3205 handle_pad_block (GstPad * pad)
3207 GstPadBlockCallback callback;
3209 GstFlowReturn ret = GST_FLOW_OK;
3211 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "signal block taken");
3213 /* flushing, don't bother trying to block and return WRONG_STATE
3215 if (GST_PAD_IS_FLUSHING (pad))
3216 goto flushingnonref;
3218 /* we grab an extra ref for the callbacks, this is probably not
3219 * needed (callback code does not have a ref and cannot unref). I
3220 * think this was done to make it possible to unref the element in
3221 * the callback, which is in the end totally impossible as it
3222 * requires grabbing the STREAM_LOCK and OBJECT_LOCK which are
3223 * all taken when calling this function. */
3224 gst_object_ref (pad);
3226 /* we either have a callback installed to notify the block or
3227 * some other thread is doing a GCond wait. */
3228 callback = pad->block_callback;
3230 /* there is a callback installed, call it. We release the
3231 * lock so that the callback can do something usefull with the
3233 user_data = pad->block_data;
3234 GST_OBJECT_UNLOCK (pad);
3235 callback (pad, TRUE, user_data);
3236 GST_OBJECT_LOCK (pad);
3238 /* no callback, signal the thread that is doing a GCond wait
3240 GST_PAD_BLOCK_SIGNAL (pad);
3243 /* OBJECT_LOCK could have been released when we did the callback, which
3244 * then could have made the pad unblock so we need to check the blocking
3245 * condition again. */
3246 while (GST_PAD_IS_BLOCKED (pad)) {
3247 if (GST_PAD_IS_FLUSHING (pad))
3250 /* now we block the streaming thread. It can be unlocked when we
3251 * deactivate the pad (which will also set the FLUSHING flag) or
3252 * when the pad is unblocked. A flushing event will also unblock
3253 * the pad after setting the FLUSHING flag. */
3254 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3255 "Waiting to be unblocked or set flushing");
3256 GST_OBJECT_FLAG_SET (pad, GST_PAD_BLOCKING);
3257 GST_PAD_BLOCK_WAIT (pad);
3259 /* see if we got unlocked by a flush or not */
3260 if (GST_PAD_IS_FLUSHING (pad))
3264 /* If we made it here we either never blocked, or were unblocked because we
3265 * weren't flushing, it is therefore safe to remove the BLOCKING flag */
3266 GST_OBJECT_FLAG_UNSET (pad, GST_PAD_BLOCKING);
3268 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "got unblocked");
3270 /* when we get here, the pad is unblocked again and we perform
3271 * the needed unblock code. */
3272 callback = pad->block_callback;
3274 /* we need to call the callback */
3275 user_data = pad->block_data;
3276 GST_OBJECT_UNLOCK (pad);
3277 callback (pad, FALSE, user_data);
3278 GST_OBJECT_LOCK (pad);
3280 /* we need to signal the thread waiting on the GCond */
3281 GST_PAD_BLOCK_SIGNAL (pad);
3284 gst_object_unref (pad);
3290 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "pad was flushing");
3291 return GST_FLOW_WRONG_STATE;
3295 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "pad became flushing");
3296 gst_object_unref (pad);
3297 return GST_FLOW_WRONG_STATE;
3301 /**********************************************************************
3302 * Data passing functions
3306 gst_pad_emit_have_data_signal (GstPad * pad, GstMiniObject * obj)
3309 GValue args[2] = { {0}, {0} };
3314 g_value_init (&ret, G_TYPE_BOOLEAN);
3315 g_value_set_boolean (&ret, TRUE);
3316 g_value_init (&args[0], GST_TYPE_PAD);
3317 g_value_set_object (&args[0], pad);
3318 g_value_init (&args[1], GST_TYPE_MINI_OBJECT); // G_TYPE_POINTER);
3319 gst_value_set_mini_object (&args[1], obj);
3321 if (GST_IS_EVENT (obj))
3322 detail = event_quark;
3324 detail = buffer_quark;
3327 g_signal_emitv (args, gst_pad_signals[PAD_HAVE_DATA], detail, &ret);
3328 res = g_value_get_boolean (&ret);
3331 g_value_unset (&ret);
3332 g_value_unset (&args[0]);
3333 g_value_unset (&args[1]);
3338 /* this is the chain function that does not perform the additional argument
3339 * checking for that little extra speed.
3341 static inline GstFlowReturn
3342 gst_pad_chain_unchecked (GstPad * pad, GstBuffer * buffer)
3345 gboolean caps_changed;
3346 GstPadChainFunction chainfunc;
3348 gboolean emit_signal;
3350 GST_PAD_STREAM_LOCK (pad);
3352 GST_OBJECT_LOCK (pad);
3353 if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad)))
3356 caps = GST_BUFFER_CAPS (buffer);
3357 caps_changed = caps && caps != GST_PAD_CAPS (pad);
3359 emit_signal = GST_PAD_DO_BUFFER_SIGNALS (pad) > 0;
3360 GST_OBJECT_UNLOCK (pad);
3362 /* see if the signal should be emited, we emit before caps nego as
3363 * we might drop the buffer and do capsnego for nothing. */
3364 if (G_UNLIKELY (emit_signal)) {
3365 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (buffer)))
3369 /* we got a new datatype on the pad, see if it can handle it */
3370 if (G_UNLIKELY (caps_changed)) {
3371 GST_DEBUG_OBJECT (pad, "caps changed to %p %" GST_PTR_FORMAT, caps, caps);
3372 if (G_UNLIKELY (!gst_pad_configure_sink (pad, caps)))
3373 goto not_negotiated;
3376 /* NOTE: we read the chainfunc unlocked.
3377 * we cannot hold the lock for the pad so we might send
3378 * the data to the wrong function. This is not really a
3379 * problem since functions are assigned at creation time
3380 * and don't change that often... */
3381 if (G_UNLIKELY ((chainfunc = GST_PAD_CHAINFUNC (pad)) == NULL))
3384 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3385 "calling chainfunction &%s", GST_DEBUG_FUNCPTR_NAME (chainfunc));
3387 ret = chainfunc (pad, buffer);
3389 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3390 "called chainfunction &%s, returned %s",
3391 GST_DEBUG_FUNCPTR_NAME (chainfunc), gst_flow_get_name (ret));
3393 GST_PAD_STREAM_UNLOCK (pad);
3400 gst_buffer_unref (buffer);
3401 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3402 "pushing, but pad was flushing");
3403 GST_OBJECT_UNLOCK (pad);
3404 GST_PAD_STREAM_UNLOCK (pad);
3405 return GST_FLOW_WRONG_STATE;
3409 gst_buffer_unref (buffer);
3410 GST_DEBUG_OBJECT (pad, "Dropping buffer due to FALSE probe return");
3411 GST_PAD_STREAM_UNLOCK (pad);
3416 gst_buffer_unref (buffer);
3417 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3418 "pushing buffer but pad did not accept");
3419 GST_PAD_STREAM_UNLOCK (pad);
3420 return GST_FLOW_NOT_NEGOTIATED;
3424 gst_buffer_unref (buffer);
3425 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3426 "pushing, but not chainhandler");
3427 GST_ELEMENT_ERROR (GST_PAD_PARENT (pad), CORE, PAD, (NULL),
3428 ("push on pad %s:%s but it has no chainfunction",
3429 GST_DEBUG_PAD_NAME (pad)));
3430 GST_PAD_STREAM_UNLOCK (pad);
3431 return GST_FLOW_NOT_SUPPORTED;
3437 * @pad: a sink #GstPad, returns GST_FLOW_ERROR if not.
3438 * @buffer: the #GstBuffer to send, return GST_FLOW_ERROR if not.
3440 * Chain a buffer to @pad.
3442 * The function returns #GST_FLOW_WRONG_STATE if the pad was flushing.
3444 * If the caps on @buffer are different from the current caps on @pad, this
3445 * function will call any setcaps function (see gst_pad_set_setcaps_function())
3446 * installed on @pad. If the new caps are not acceptable for @pad, this function
3447 * returns #GST_FLOW_NOT_NEGOTIATED.
3449 * The function proceeds calling the chain function installed on @pad (see
3450 * gst_pad_set_chain_function()) and the return value of that function is
3451 * returned to the caller. #GST_FLOW_NOT_SUPPORTED is returned if @pad has no
3454 * In all cases, success or failure, the caller loses its reference to @buffer
3455 * after calling this function.
3457 * Returns: a #GstFlowReturn from the pad.
3462 gst_pad_chain (GstPad * pad, GstBuffer * buffer)
3464 g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
3465 g_return_val_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SINK,
3467 g_return_val_if_fail (GST_IS_BUFFER (buffer), GST_FLOW_ERROR);
3469 return gst_pad_chain_unchecked (pad, buffer);
3474 * @pad: a source #GstPad, returns #GST_FLOW_ERROR if not.
3475 * @buffer: the #GstBuffer to push returns GST_FLOW_ERROR if not.
3477 * Pushes a buffer to the peer of @pad.
3479 * This function will call an installed pad block before triggering any
3480 * installed pad probes.
3482 * If the caps on @buffer are different from the currently configured caps on
3483 * @pad, this function will call any installed setcaps function on @pad (see
3484 * gst_pad_set_setcaps_function()). In case of failure to renegotiate the new
3485 * format, this function returns #GST_FLOW_NOT_NEGOTIATED.
3487 * The function proceeds calling gst_pad_chain() on the peer pad and returns the
3488 * value from that function. If @pad has no peer, #GST_FLOW_NOT_LINKED will be
3491 * In all cases, success or failure, the caller loses its reference to @buffer
3492 * after calling this function.
3494 * Returns: a #GstFlowReturn from the peer pad.
3499 gst_pad_push (GstPad * pad, GstBuffer * buffer)
3505 gboolean caps_changed;
3507 g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
3508 g_return_val_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SRC, GST_FLOW_ERROR);
3509 g_return_val_if_fail (GST_IS_BUFFER (buffer), GST_FLOW_ERROR);
3511 GST_OBJECT_LOCK (pad);
3513 /* FIXME: this check can go away; pad_set_blocked could be implemented with
3514 * probes completely or probes with an extended pad block. */
3515 while (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad)))
3516 if ((ret = handle_pad_block (pad)) != GST_FLOW_OK)
3519 /* we emit signals on the pad arg, the peer will have a chance to
3520 * emit in the _chain() function */
3521 if (G_UNLIKELY (GST_PAD_DO_BUFFER_SIGNALS (pad) > 0)) {
3522 /* unlock before emitting */
3523 GST_OBJECT_UNLOCK (pad);
3525 /* if the signal handler returned FALSE, it means we should just drop the
3527 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (buffer)))
3530 GST_OBJECT_LOCK (pad);
3533 if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
3536 /* take ref to peer pad before releasing the lock */
3537 gst_object_ref (peer);
3539 /* Before pushing the buffer to the peer pad, ensure that caps
3540 * are set on this pad */
3541 caps = GST_BUFFER_CAPS (buffer);
3542 caps_changed = caps && caps != GST_PAD_CAPS (pad);
3544 GST_OBJECT_UNLOCK (pad);
3546 /* we got a new datatype from the pad, it had better handle it */
3547 if (G_UNLIKELY (caps_changed)) {
3548 GST_DEBUG_OBJECT (pad, "caps changed to %p %" GST_PTR_FORMAT, caps, caps);
3549 if (G_UNLIKELY (!gst_pad_configure_src (pad, caps, TRUE)))
3550 goto not_negotiated;
3553 ret = gst_pad_chain_unchecked (peer, buffer);
3555 gst_object_unref (peer);
3559 /* ERROR recovery here */
3562 gst_buffer_unref (buffer);
3563 GST_DEBUG_OBJECT (pad, "pad block stopped by flush");
3564 GST_OBJECT_UNLOCK (pad);
3569 gst_buffer_unref (buffer);
3570 GST_DEBUG_OBJECT (pad, "Dropping buffer due to FALSE probe return");
3575 gst_buffer_unref (buffer);
3576 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3577 "pushing, but it was not linked");
3578 GST_OBJECT_UNLOCK (pad);
3579 return GST_FLOW_NOT_LINKED;
3583 gst_buffer_unref (buffer);
3584 gst_object_unref (peer);
3585 GST_CAT_DEBUG_OBJECT (GST_CAT_SCHEDULING, pad,
3586 "element pushed buffer then refused to accept the caps");
3587 return GST_FLOW_NOT_NEGOTIATED;
3592 * gst_pad_check_pull_range:
3593 * @pad: a sink #GstPad.
3595 * Checks if a gst_pad_pull_range() can be performed on the peer
3596 * source pad. This function is used by plugins that want to check
3597 * if they can use random access on the peer source pad.
3599 * The peer sourcepad can implement a custom #GstPadCheckGetRangeFunction
3600 * if it needs to perform some logic to determine if pull_range is
3603 * Returns: a gboolean with the result.
3608 gst_pad_check_pull_range (GstPad * pad)
3612 GstPadCheckGetRangeFunction checkgetrangefunc;
3614 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
3616 GST_OBJECT_LOCK (pad);
3617 if (GST_PAD_DIRECTION (pad) != GST_PAD_SINK)
3618 goto wrong_direction;
3620 if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
3623 gst_object_ref (peer);
3624 GST_OBJECT_UNLOCK (pad);
3626 /* see note in above function */
3627 if (G_LIKELY ((checkgetrangefunc = peer->checkgetrangefunc) == NULL)) {
3628 /* FIXME, kindoff ghetto */
3629 ret = GST_PAD_GETRANGEFUNC (peer) != NULL;
3631 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3632 "calling checkgetrangefunc %s of peer pad %s:%s",
3633 GST_DEBUG_FUNCPTR_NAME (checkgetrangefunc), GST_DEBUG_PAD_NAME (peer));
3635 ret = checkgetrangefunc (peer);
3638 gst_object_unref (peer);
3642 /* ERROR recovery here */
3645 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3646 "checking pull range, but pad must be a sinkpad");
3647 GST_OBJECT_UNLOCK (pad);
3652 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3653 "checking pull range, but it was not linked");
3654 GST_OBJECT_UNLOCK (pad);
3660 * gst_pad_get_range:
3661 * @pad: a src #GstPad, returns #GST_FLOW_ERROR if not.
3662 * @offset: The start offset of the buffer
3663 * @size: The length of the buffer
3664 * @buffer: a pointer to hold the #GstBuffer, returns #GST_FLOW_ERROR if %NULL.
3666 * When @pad is flushing this function returns #GST_FLOW_WRONG_STATE
3669 * Calls the getrange function of @pad, see #GstPadGetRangeFunction for a
3670 * description of a getrange function. If @pad has no getrange function
3671 * installed (see gst_pad_set_getrange_function()) this function returns
3672 * #GST_FLOW_NOT_SUPPORTED.
3674 * Returns: a #GstFlowReturn from the pad.
3679 gst_pad_get_range (GstPad * pad, guint64 offset, guint size,
3680 GstBuffer ** buffer)
3683 GstPadGetRangeFunction getrangefunc;
3684 gboolean emit_signal;
3686 g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
3687 g_return_val_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SRC, GST_FLOW_ERROR);
3688 g_return_val_if_fail (buffer != NULL, GST_FLOW_ERROR);
3690 GST_PAD_STREAM_LOCK (pad);
3692 GST_OBJECT_LOCK (pad);
3693 if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad)))
3696 emit_signal = GST_PAD_DO_BUFFER_SIGNALS (pad) > 0;
3697 GST_OBJECT_UNLOCK (pad);
3699 if (G_UNLIKELY ((getrangefunc = GST_PAD_GETRANGEFUNC (pad)) == NULL))
3702 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3703 "calling getrangefunc %s, offset %"
3704 G_GUINT64_FORMAT ", size %u",
3705 GST_DEBUG_FUNCPTR_NAME (getrangefunc), offset, size);
3707 ret = getrangefunc (pad, offset, size, buffer);
3709 /* can only fire the signal if we have a valid buffer */
3710 if (G_UNLIKELY (emit_signal) && (ret == GST_FLOW_OK)) {
3711 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (*buffer)))
3715 GST_PAD_STREAM_UNLOCK (pad);
3722 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3723 "pulling range, but pad was flushing");
3724 GST_OBJECT_UNLOCK (pad);
3725 GST_PAD_STREAM_UNLOCK (pad);
3726 return GST_FLOW_WRONG_STATE;
3730 GST_ELEMENT_ERROR (GST_PAD_PARENT (pad), CORE, PAD, (NULL),
3731 ("pullrange on pad %s:%s but it has no getrangefunction",
3732 GST_DEBUG_PAD_NAME (pad)));
3733 GST_PAD_STREAM_UNLOCK (pad);
3734 return GST_FLOW_NOT_SUPPORTED;
3738 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3739 "Dropping data after FALSE probe return");
3740 GST_PAD_STREAM_UNLOCK (pad);
3741 gst_buffer_unref (*buffer);
3743 return GST_FLOW_UNEXPECTED;
3749 * gst_pad_pull_range:
3750 * @pad: a sink #GstPad, returns GST_FLOW_ERROR if not.
3751 * @offset: The start offset of the buffer
3752 * @size: The length of the buffer
3753 * @buffer: a pointer to hold the #GstBuffer, returns GST_FLOW_ERROR if %NULL.
3755 * Pulls a buffer from the peer pad.
3757 * This function will first trigger the pad block signal if it was
3760 * When @pad is not linked #GST_FLOW_NOT_LINKED is returned else this
3761 * function returns the result of gst_pad_get_range() on the peer pad.
3762 * See gst_pad_get_range() for a list of return values and for the
3763 * semantics of the arguments of this function.
3765 * Returns: a #GstFlowReturn from the peer pad.
3766 * When this function returns #GST_FLOW_OK, @buffer will contain a valid
3767 * #GstBuffer that should be freed with gst_buffer_unref() after usage.
3768 * @buffer may not be used or freed when any other return value than
3769 * #GST_FLOW_OK is returned.
3774 gst_pad_pull_range (GstPad * pad, guint64 offset, guint size,
3775 GstBuffer ** buffer)
3779 gboolean emit_signal;
3781 g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
3782 g_return_val_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SINK,
3784 g_return_val_if_fail (buffer != NULL, GST_FLOW_ERROR);
3786 GST_OBJECT_LOCK (pad);
3788 while (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad)))
3789 handle_pad_block (pad);
3791 if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
3794 /* signal emision for the pad, peer has chance to emit when
3795 * we call _get_range() */
3796 emit_signal = GST_PAD_DO_BUFFER_SIGNALS (pad) > 0;
3798 gst_object_ref (peer);
3799 GST_OBJECT_UNLOCK (pad);
3801 ret = gst_pad_get_range (peer, offset, size, buffer);
3803 gst_object_unref (peer);
3805 /* can only fire the signal if we have a valid buffer */
3806 if (G_UNLIKELY (emit_signal) && (ret == GST_FLOW_OK)) {
3807 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (*buffer)))
3812 /* ERROR recovery here */
3815 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3816 "pulling range, but it was not linked");
3817 GST_OBJECT_UNLOCK (pad);
3818 return GST_FLOW_NOT_LINKED;
3822 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3823 "Dropping data after FALSE probe return");
3824 gst_buffer_unref (*buffer);
3826 return GST_FLOW_UNEXPECTED;
3831 * gst_pad_push_event:
3832 * @pad: a #GstPad to push the event to.
3833 * @event: the #GstEvent to send to the pad.
3835 * Sends the event to the peer of the given pad. This function is
3836 * mainly used by elements to send events to their peer
3839 * This function takes owership of the provided event so you should
3840 * gst_event_ref() it if you want to reuse the event after this call.
3842 * Returns: TRUE if the event was handled.
3847 gst_pad_push_event (GstPad * pad, GstEvent * event)
3852 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
3853 g_return_val_if_fail (event != NULL, FALSE);
3854 g_return_val_if_fail (GST_IS_EVENT (event), FALSE);
3856 GST_LOG_OBJECT (pad, "event:%s", GST_EVENT_TYPE_NAME (event));
3858 GST_OBJECT_LOCK (pad);
3860 /* Two checks to be made:
3861 * . (un)set the FLUSHING flag for flushing events,
3862 * . handle pad blocking */
3863 switch (GST_EVENT_TYPE (event)) {
3864 case GST_EVENT_FLUSH_START:
3865 GST_PAD_SET_FLUSHING (pad);
3867 if (G_UNLIKELY (GST_PAD_IS_BLOCKING (pad))) {
3868 /* flush start will have set the FLUSHING flag and will then
3869 * unlock all threads doing a GCond wait on the blocking pad. This
3870 * will typically unblock the STREAMING thread blocked on a pad. */
3871 GST_PAD_BLOCK_SIGNAL (pad);
3875 case GST_EVENT_FLUSH_STOP:
3876 GST_PAD_UNSET_FLUSHING (pad);
3878 /* If pad was blocking on something when the pad received flush-start, we
3879 * don't forward the flush-stop event either. */
3880 if (G_UNLIKELY (GST_PAD_IS_BLOCKING (pad))) {
3881 GST_OBJECT_FLAG_UNSET (pad, GST_PAD_BLOCKING);
3882 GST_LOG_OBJECT (pad,
3883 "Pad was previously blocking, not forwarding flush-stop");
3886 GST_OBJECT_FLAG_UNSET (pad, GST_PAD_BLOCKING);
3889 if (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad))) {
3890 if (GST_PAD_IS_FLUSHING (pad))
3892 while (GST_PAD_IS_BLOCKED (pad))
3893 /* else block the event as long as the pad is blocked */
3894 if (handle_pad_block (pad) != GST_FLOW_OK)
3900 if (G_UNLIKELY (GST_PAD_DO_EVENT_SIGNALS (pad) > 0)) {
3901 GST_OBJECT_UNLOCK (pad);
3903 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (event)))
3906 GST_OBJECT_LOCK (pad);
3908 peerpad = GST_PAD_PEER (pad);
3909 if (peerpad == NULL)
3912 GST_LOG_OBJECT (pad, "sending event to peerpad %" GST_PTR_FORMAT, peerpad);
3913 gst_object_ref (peerpad);
3914 GST_OBJECT_UNLOCK (pad);
3916 result = gst_pad_send_event (peerpad, event);
3918 GST_LOG_OBJECT (pad, "sent event to peerpad %" GST_PTR_FORMAT, peerpad);
3919 gst_object_unref (peerpad);
3923 /* ERROR handling */
3926 GST_DEBUG_OBJECT (pad, "Dropping event after FALSE probe return");
3927 gst_event_unref (event);
3932 GST_DEBUG_OBJECT (pad, "Dropping event because pad is not linked");
3933 gst_event_unref (event);
3934 GST_OBJECT_UNLOCK (pad);
3940 GST_DEBUG_OBJECT (pad,
3941 "Not forwarding event since we're flushing and blocking");
3942 gst_event_unref (event);
3943 GST_OBJECT_UNLOCK (pad);
3949 * gst_pad_send_event:
3950 * @pad: a #GstPad to send the event to.
3951 * @event: the #GstEvent to send to the pad.
3953 * Sends the event to the pad. This function can be used
3954 * by applications to send events in the pipeline.
3956 * If @pad is a source pad, @event should be an upstream event. If @pad is a
3957 * sink pad, @event should be a downstream event. For example, you would not
3958 * send a #GST_EVENT_EOS on a src pad; EOS events only propagate downstream.
3959 * Furthermore, some downstream events have to be serialized with data flow,
3960 * like EOS, while some can travel out-of-band, like #GST_EVENT_FLUSH_START. If
3961 * the event needs to be serialized with data flow, this function will take the
3962 * pad's stream lock while calling its event function.
3964 * To find out whether an event type is upstream, downstream, or downstream and
3965 * serialized, see #GstEventTypeFlags, gst_event_type_get_flags(),
3966 * #GST_EVENT_IS_UPSTREAM, #GST_EVENT_IS_DOWNSTREAM, and
3967 * #GST_EVENT_IS_SERIALIZED. Note that in practice that an application or plugin
3968 * doesn't need to bother itself with this information; the core handles all
3969 * necessary locks and checks.
3971 * This function takes owership of the provided event so you should
3972 * gst_event_ref() it if you want to reuse the event after this call.
3974 * Returns: TRUE if the event was handled.
3977 gst_pad_send_event (GstPad * pad, GstEvent * event)
3979 gboolean result = FALSE;
3980 GstPadEventFunction eventfunc;
3981 gboolean serialized, need_unlock = FALSE;
3983 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
3984 g_return_val_if_fail (event != NULL, FALSE);
3986 GST_OBJECT_LOCK (pad);
3987 if (GST_PAD_IS_SINK (pad)) {
3988 if (G_UNLIKELY (!GST_EVENT_IS_DOWNSTREAM (event)))
3989 goto wrong_direction;
3990 serialized = GST_EVENT_IS_SERIALIZED (event);
3991 } else if (GST_PAD_IS_SRC (pad)) {
3992 if (G_UNLIKELY (!GST_EVENT_IS_UPSTREAM (event)))
3993 goto wrong_direction;
3994 /* events on srcpad never are serialized */
3997 goto unknown_direction;
3999 if (G_UNLIKELY (GST_EVENT_SRC (event) == NULL)) {
4000 GST_LOG_OBJECT (pad, "event had no source, setting pad as event source");
4001 GST_EVENT_SRC (event) = gst_object_ref (pad);
4005 if (G_UNLIKELY (GST_PAD_DO_EVENT_SIGNALS (pad) > 0)) {
4006 GST_OBJECT_UNLOCK (pad);
4008 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT_CAST (event)))
4011 GST_OBJECT_LOCK (pad);
4014 switch (GST_EVENT_TYPE (event)) {
4015 case GST_EVENT_FLUSH_START:
4016 GST_CAT_DEBUG_OBJECT (GST_CAT_EVENT, pad,
4017 "have event type %d (FLUSH_START)", GST_EVENT_TYPE (event));
4019 /* can't even accept a flush begin event when flushing */
4020 if (GST_PAD_IS_FLUSHING (pad))
4022 GST_PAD_SET_FLUSHING (pad);
4023 GST_CAT_DEBUG_OBJECT (GST_CAT_EVENT, pad, "set flush flag");
4025 case GST_EVENT_FLUSH_STOP:
4026 GST_PAD_UNSET_FLUSHING (pad);
4027 GST_CAT_DEBUG_OBJECT (GST_CAT_EVENT, pad, "cleared flush flag");
4028 GST_OBJECT_UNLOCK (pad);
4029 /* grab stream lock */
4030 GST_PAD_STREAM_LOCK (pad);
4032 GST_OBJECT_LOCK (pad);
4035 GST_CAT_DEBUG_OBJECT (GST_CAT_EVENT, pad, "have event type %s",
4036 GST_EVENT_TYPE_NAME (event));
4038 /* make this a little faster, no point in grabbing the lock
4039 * if the pad is allready flushing. */
4040 if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad)))
4044 /* lock order: STREAM_LOCK, LOCK */
4045 GST_OBJECT_UNLOCK (pad);
4046 GST_PAD_STREAM_LOCK (pad);
4048 GST_OBJECT_LOCK (pad);
4049 if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad)))
4054 if (G_UNLIKELY ((eventfunc = GST_PAD_EVENTFUNC (pad)) == NULL))
4057 GST_OBJECT_UNLOCK (pad);
4059 result = eventfunc (pad, event);
4062 GST_PAD_STREAM_UNLOCK (pad);
4066 /* ERROR handling */
4069 g_warning ("pad %s:%s sending %s event in wrong direction",
4070 GST_DEBUG_PAD_NAME (pad), GST_EVENT_TYPE_NAME (event));
4071 GST_OBJECT_UNLOCK (pad);
4072 gst_event_unref (event);
4077 g_warning ("pad %s:%s has invalid direction", GST_DEBUG_PAD_NAME (pad));
4078 GST_OBJECT_UNLOCK (pad);
4079 gst_event_unref (event);
4084 g_warning ("pad %s:%s has no event handler, file a bug.",
4085 GST_DEBUG_PAD_NAME (pad));
4086 GST_OBJECT_UNLOCK (pad);
4087 gst_event_unref (event);
4092 GST_OBJECT_UNLOCK (pad);
4094 GST_PAD_STREAM_UNLOCK (pad);
4095 GST_CAT_INFO_OBJECT (GST_CAT_EVENT, pad,
4096 "Received event on flushing pad. Discarding");
4097 gst_event_unref (event);
4102 GST_DEBUG_OBJECT (pad, "Dropping event after FALSE probe return");
4103 gst_event_unref (event);
4109 * gst_pad_set_element_private:
4110 * @pad: the #GstPad to set the private data of.
4111 * @priv: The private data to attach to the pad.
4113 * Set the given private data gpointer on the pad.
4114 * This function can only be used by the element that owns the pad.
4115 * No locking is performed in this function.
4118 gst_pad_set_element_private (GstPad * pad, gpointer priv)
4120 pad->element_private = priv;
4124 * gst_pad_get_element_private:
4125 * @pad: the #GstPad to get the private data of.
4127 * Gets the private data of a pad.
4128 * No locking is performed in this function.
4130 * Returns: a #gpointer to the private data.
4133 gst_pad_get_element_private (GstPad * pad)
4135 return pad->element_private;
4139 * gst_pad_start_task:
4140 * @pad: the #GstPad to start the task of
4141 * @func: the task function to call
4142 * @data: data passed to the task function
4144 * Starts a task that repeadedly calls @func with @data. This function
4145 * is nostly used in the pad activation function to start the
4146 * dataflow. This function will automatically acquire the STREAM_LOCK of
4147 * the pad before calling @func.
4149 * Returns: a TRUE if the task could be started.
4152 gst_pad_start_task (GstPad * pad, GstTaskFunction func, gpointer data)
4156 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
4157 g_return_val_if_fail (func != NULL, FALSE);
4159 GST_DEBUG_OBJECT (pad, "start task");
4161 GST_OBJECT_LOCK (pad);
4162 task = GST_PAD_TASK (pad);
4164 task = gst_task_create (func, data);
4165 gst_task_set_lock (task, GST_PAD_GET_STREAM_LOCK (pad));
4166 GST_PAD_TASK (pad) = task;
4167 GST_DEBUG_OBJECT (pad, "created task");
4169 gst_task_start (task);
4170 GST_OBJECT_UNLOCK (pad);
4176 * gst_pad_pause_task:
4177 * @pad: the #GstPad to pause the task of
4179 * Pause the task of @pad. This function will also make sure that the
4180 * function executed by the task will effectively stop.
4182 * Returns: a TRUE if the task could be paused or FALSE when the pad
4186 gst_pad_pause_task (GstPad * pad)
4190 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
4192 GST_DEBUG_OBJECT (pad, "pause task");
4194 GST_OBJECT_LOCK (pad);
4195 task = GST_PAD_TASK (pad);
4198 gst_task_pause (task);
4199 GST_OBJECT_UNLOCK (pad);
4201 GST_PAD_STREAM_LOCK (pad);
4202 GST_PAD_STREAM_UNLOCK (pad);
4208 GST_DEBUG_OBJECT (pad, "pad has no task");
4209 GST_OBJECT_UNLOCK (pad);
4215 * gst_pad_stop_task:
4216 * @pad: the #GstPad to stop the task of
4218 * Stop the task of @pad. This function will also make sure that the
4219 * function executed by the task will effectively stop if not called
4220 * from the GstTaskFunction.
4222 * This function will deadlock if called from the GstTaskFunction of
4223 * the task. Use gst_task_pause() instead.
4225 * Regardless of whether the pad has a task, the stream lock is acquired and
4226 * released so as to ensure that streaming through this pad has finished.
4228 * Returns: a TRUE if the task could be stopped or FALSE on error.
4231 gst_pad_stop_task (GstPad * pad)
4235 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
4237 GST_DEBUG_OBJECT (pad, "stop task");
4239 GST_OBJECT_LOCK (pad);
4240 task = GST_PAD_TASK (pad);
4243 GST_PAD_TASK (pad) = NULL;
4244 gst_task_stop (task);
4245 GST_OBJECT_UNLOCK (pad);
4247 GST_PAD_STREAM_LOCK (pad);
4248 GST_PAD_STREAM_UNLOCK (pad);
4250 if (!gst_task_join (task))
4253 gst_object_unref (task);
4259 GST_DEBUG_OBJECT (pad, "no task");
4260 GST_OBJECT_UNLOCK (pad);
4262 GST_PAD_STREAM_LOCK (pad);
4263 GST_PAD_STREAM_UNLOCK (pad);
4265 /* this is not an error */
4270 /* this is bad, possibly the application tried to join the task from
4271 * the task's thread. We install the task again so that it will be stopped
4272 * again from the right thread next time hopefully. */
4273 GST_OBJECT_LOCK (pad);
4274 GST_DEBUG_OBJECT (pad, "join failed");
4275 /* we can only install this task if there was no other task */
4276 if (GST_PAD_TASK (pad) == NULL)
4277 GST_PAD_TASK (pad) = task;
4278 GST_OBJECT_UNLOCK (pad);