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;
356 GST_PAD_SET_FLUSHING (pad);
358 /* FIXME, should be set flushing initially, see #339326 */
359 GST_PAD_UNSET_FLUSHING (pad);
362 pad->preroll_lock = g_mutex_new ();
363 pad->preroll_cond = g_cond_new ();
365 pad->stream_rec_lock = g_new (GStaticRecMutex, 1);
366 g_static_rec_mutex_init (pad->stream_rec_lock);
368 pad->block_cond = g_cond_new ();
372 gst_pad_dispose (GObject * object)
374 GstPad *pad = GST_PAD (object);
376 GST_CAT_DEBUG_OBJECT (GST_CAT_REFCOUNTING, pad, "dispose");
378 /* we don't hold a ref to the peer so we can just set the
380 GST_PAD_PEER (pad) = NULL;
383 gst_caps_replace (&GST_PAD_CAPS (pad), NULL);
385 gst_pad_set_pad_template (pad, NULL);
387 G_OBJECT_CLASS (parent_class)->dispose (object);
391 gst_pad_finalize (GObject * object)
393 GstPad *pad = GST_PAD (object);
396 /* in case the task is still around, clean it up */
397 if ((task = GST_PAD_TASK (pad))) {
398 gst_task_join (task);
399 GST_PAD_TASK (pad) = NULL;
400 gst_object_unref (task);
403 if (pad->stream_rec_lock) {
404 g_static_rec_mutex_free (pad->stream_rec_lock);
405 g_free (pad->stream_rec_lock);
406 pad->stream_rec_lock = NULL;
408 if (pad->preroll_lock) {
409 g_mutex_free (pad->preroll_lock);
410 g_cond_free (pad->preroll_cond);
411 pad->preroll_lock = NULL;
412 pad->preroll_cond = NULL;
414 if (pad->block_cond) {
415 g_cond_free (pad->block_cond);
416 pad->block_cond = NULL;
419 G_OBJECT_CLASS (parent_class)->finalize (object);
423 gst_pad_set_property (GObject * object, guint prop_id,
424 const GValue * value, GParamSpec * pspec)
426 g_return_if_fail (GST_IS_PAD (object));
429 case PAD_PROP_DIRECTION:
430 GST_PAD_DIRECTION (object) = g_value_get_enum (value);
432 case PAD_PROP_TEMPLATE:
433 gst_pad_set_pad_template (GST_PAD_CAST (object),
434 (GstPadTemplate *) g_value_get_object (value));
437 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
443 gst_pad_get_property (GObject * object, guint prop_id,
444 GValue * value, GParamSpec * pspec)
446 g_return_if_fail (GST_IS_PAD (object));
450 GST_OBJECT_LOCK (object);
451 g_value_set_boxed (value, GST_PAD_CAPS (object));
452 GST_OBJECT_UNLOCK (object);
454 case PAD_PROP_DIRECTION:
455 g_value_set_enum (value, GST_PAD_DIRECTION (object));
457 case PAD_PROP_TEMPLATE:
458 g_value_set_object (value, GST_PAD_PAD_TEMPLATE (object));
461 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
468 * @name: the name of the new pad.
469 * @direction: the #GstPadDirection of the pad.
471 * Creates a new pad with the given name in the given direction.
472 * If name is NULL, a guaranteed unique name (across all pads)
474 * This function makes a copy of the name so you can safely free the name.
476 * Returns: a new #GstPad, or NULL in case of an error.
481 gst_pad_new (const gchar * name, GstPadDirection direction)
483 return g_object_new (GST_TYPE_PAD,
484 "name", name, "direction", direction, NULL);
488 * gst_pad_new_from_template:
489 * @templ: the pad template to use
490 * @name: the name of the element
492 * Creates a new pad with the given name from the given template.
493 * If name is NULL, a guaranteed unique name (across all pads)
495 * This function makes a copy of the name so you can safely free the name.
497 * Returns: a new #GstPad, or NULL in case of an error.
500 gst_pad_new_from_template (GstPadTemplate * templ, const gchar * name)
502 g_return_val_if_fail (GST_IS_PAD_TEMPLATE (templ), NULL);
504 return g_object_new (GST_TYPE_PAD,
505 "name", name, "direction", templ->direction, "template", templ, NULL);
509 * gst_pad_new_from_static_template:
510 * @templ: the #GstStaticPadTemplate to use
511 * @name: the name of the element
513 * Creates a new pad with the given name from the given static template.
514 * If name is NULL, a guaranteed unique name (across all pads)
516 * This function makes a copy of the name so you can safely free the name.
518 * Returns: a new #GstPad, or NULL in case of an error.
521 gst_pad_new_from_static_template (GstStaticPadTemplate * templ,
525 GstPadTemplate *template;
527 template = gst_static_pad_template_get (templ);
528 pad = gst_pad_new_from_template (template, name);
529 gst_object_unref (template);
534 * gst_pad_get_direction:
535 * @pad: a #GstPad to get the direction of.
537 * Gets the direction of the pad. The direction of the pad is
538 * decided at construction time so this function does not take
541 * Returns: the #GstPadDirection of the pad.
546 gst_pad_get_direction (GstPad * pad)
548 GstPadDirection result;
550 /* PAD_UNKNOWN is a little silly but we need some sort of
551 * error return value */
552 g_return_val_if_fail (GST_IS_PAD (pad), GST_PAD_UNKNOWN);
554 GST_OBJECT_LOCK (pad);
555 result = GST_PAD_DIRECTION (pad);
556 GST_OBJECT_UNLOCK (pad);
562 gst_pad_activate_default (GstPad * pad)
564 return gst_pad_activate_push (pad, TRUE);
568 pre_activate (GstPad * pad, GstActivateMode new_mode)
571 case GST_ACTIVATE_PUSH:
572 case GST_ACTIVATE_PULL:
573 GST_OBJECT_LOCK (pad);
574 GST_DEBUG_OBJECT (pad, "setting ACTIVATE_MODE %d, unset flushing",
576 GST_PAD_UNSET_FLUSHING (pad);
577 GST_PAD_ACTIVATE_MODE (pad) = new_mode;
578 GST_OBJECT_UNLOCK (pad);
580 case GST_ACTIVATE_NONE:
581 GST_OBJECT_LOCK (pad);
582 GST_DEBUG_OBJECT (pad, "setting ACTIVATE_MODE NONE, set flushing");
583 GST_PAD_SET_FLUSHING (pad);
584 /* unlock blocked pads so element can resume and stop */
585 GST_PAD_BLOCK_BROADCAST (pad);
586 GST_OBJECT_UNLOCK (pad);
592 post_activate (GstPad * pad, GstActivateMode new_mode)
595 case GST_ACTIVATE_PUSH:
596 case GST_ACTIVATE_PULL:
599 case GST_ACTIVATE_NONE:
600 /* ensures that streaming stops */
601 GST_PAD_STREAM_LOCK (pad);
602 /* while we're at it set activation mode */
603 GST_OBJECT_LOCK (pad);
604 GST_DEBUG_OBJECT (pad, "setting ACTIVATE_MODE %d", new_mode);
605 GST_PAD_ACTIVATE_MODE (pad) = new_mode;
606 GST_OBJECT_UNLOCK (pad);
607 GST_PAD_STREAM_UNLOCK (pad);
613 * gst_pad_set_active:
614 * @pad: the #GstPad to activate or deactivate.
615 * @active: whether or not the pad should be active.
617 * Activates or deactivates the given pad.
618 * Normally called from within core state change functions.
620 * If @active, makes sure the pad is active. If it is already active, either in
621 * push or pull mode, just return. Otherwise dispatches to the pad's activate
622 * function to perform the actual activation.
624 * If not @active, checks the pad's current mode and calls
625 * gst_pad_activate_push() or gst_pad_activate_pull(), as appropriate, with a
628 * Returns: #TRUE if the operation was successful.
633 gst_pad_set_active (GstPad * pad, gboolean active)
636 gboolean ret = FALSE;
638 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
640 GST_OBJECT_LOCK (pad);
641 old = GST_PAD_ACTIVATE_MODE (pad);
642 GST_OBJECT_UNLOCK (pad);
646 case GST_ACTIVATE_PUSH:
647 case GST_ACTIVATE_PULL:
650 case GST_ACTIVATE_NONE:
651 ret = (GST_PAD_ACTIVATEFUNC (pad)) (pad);
656 case GST_ACTIVATE_PUSH:
657 ret = gst_pad_activate_push (pad, FALSE);
659 case GST_ACTIVATE_PULL:
660 ret = gst_pad_activate_pull (pad, FALSE);
662 case GST_ACTIVATE_NONE:
669 GST_OBJECT_LOCK (pad);
671 g_critical ("Failed to deactivate pad %s:%s, very bad",
672 GST_DEBUG_PAD_NAME (pad));
674 GST_WARNING ("Failed to activate pad %s:%s", GST_DEBUG_PAD_NAME (pad));
676 GST_OBJECT_UNLOCK (pad);
683 * gst_pad_activate_pull:
684 * @pad: the #GstPad to activate or deactivate.
685 * @active: whether or not the pad should be active.
687 * Activates or deactivates the given pad in pull mode via dispatching to the
688 * pad's activatepullfunc. For use from within pad activation functions only.
689 * When called on sink pads, will first proxy the call to the peer pad, which is
690 * expected to activate its internally linked pads from within its activate_pull
693 * If you don't know what this is, you probably don't want to call it.
695 * Returns: TRUE if the operation was successful.
700 gst_pad_activate_pull (GstPad * pad, gboolean active)
702 GstActivateMode old, new;
705 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
707 GST_OBJECT_LOCK (pad);
708 old = GST_PAD_ACTIVATE_MODE (pad);
709 GST_OBJECT_UNLOCK (pad);
713 case GST_ACTIVATE_PULL:
715 case GST_ACTIVATE_PUSH:
716 /* pad was activate in the wrong direction, deactivate it
717 * and reactivate it in pull mode */
718 if (G_UNLIKELY (!gst_pad_activate_push (pad, FALSE)))
719 goto deactivate_failed;
720 /* fallthrough, pad is deactivated now. */
721 case GST_ACTIVATE_NONE:
726 case GST_ACTIVATE_NONE:
728 case GST_ACTIVATE_PUSH:
729 /* pad was activated in the other direction, deactivate it
730 * in push mode, this should not happen... */
731 if (G_UNLIKELY (!gst_pad_activate_push (pad, FALSE)))
732 goto deactivate_failed;
733 /* everything is fine now */
735 case GST_ACTIVATE_PULL:
740 if (gst_pad_get_direction (pad) == GST_PAD_SINK) {
741 if ((peer = gst_pad_get_peer (pad))) {
742 if (G_UNLIKELY (!gst_pad_activate_pull (peer, active)))
744 gst_object_unref (peer);
747 if (G_UNLIKELY (GST_PAD_GETRANGEFUNC (pad) == NULL))
748 goto failure; /* Can't activate pull on a src without a
752 new = active ? GST_ACTIVATE_PULL : GST_ACTIVATE_NONE;
753 pre_activate (pad, new);
755 if (GST_PAD_ACTIVATEPULLFUNC (pad)) {
756 if (G_UNLIKELY (!GST_PAD_ACTIVATEPULLFUNC (pad) (pad, active)))
759 /* can happen for sinks of passthrough elements */
762 post_activate (pad, new);
764 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "%s in pull mode",
765 active ? "activated" : "deactivated");
771 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "already %s in pull mode",
772 active ? "activated" : "deactivated");
777 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
778 "failed to %s in switch to pull from mode %d",
779 (active ? "activate" : "deactivate"), old);
784 GST_OBJECT_LOCK (peer);
785 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
786 "activate_pull on peer (%s:%s) failed", GST_DEBUG_PAD_NAME (peer));
787 GST_OBJECT_UNLOCK (peer);
788 gst_object_unref (peer);
793 GST_OBJECT_LOCK (pad);
794 GST_CAT_INFO_OBJECT (GST_CAT_PADS, pad, "failed to %s in pull mode",
795 active ? "activate" : "deactivate");
796 GST_PAD_SET_FLUSHING (pad);
797 GST_PAD_ACTIVATE_MODE (pad) = old;
798 GST_OBJECT_UNLOCK (pad);
804 * gst_pad_activate_push:
805 * @pad: the #GstPad to activate or deactivate.
806 * @active: whether the pad should be active or not.
808 * Activates or deactivates the given pad in push mode via dispatching to the
809 * pad's activatepushfunc. For use from within pad activation functions only.
811 * If you don't know what this is, you probably don't want to call it.
813 * Returns: %TRUE if the operation was successful.
818 gst_pad_activate_push (GstPad * pad, gboolean active)
820 GstActivateMode old, new;
822 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
823 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "trying to set %s in push mode",
824 active ? "activated" : "deactivated");
826 GST_OBJECT_LOCK (pad);
827 old = GST_PAD_ACTIVATE_MODE (pad);
828 GST_OBJECT_UNLOCK (pad);
832 case GST_ACTIVATE_PUSH:
834 case GST_ACTIVATE_PULL:
835 /* pad was activate in the wrong direction, deactivate it
836 * an reactivate it in push mode */
837 if (G_UNLIKELY (!gst_pad_activate_pull (pad, FALSE)))
838 goto deactivate_failed;
839 /* fallthrough, pad is deactivated now. */
840 case GST_ACTIVATE_NONE:
845 case GST_ACTIVATE_NONE:
847 case GST_ACTIVATE_PULL:
848 /* pad was activated in the other direction, deactivate it
849 * in pull mode, this should not happen... */
850 if (G_UNLIKELY (!gst_pad_activate_pull (pad, FALSE)))
851 goto deactivate_failed;
852 /* everything is fine now */
854 case GST_ACTIVATE_PUSH:
859 new = active ? GST_ACTIVATE_PUSH : GST_ACTIVATE_NONE;
860 pre_activate (pad, new);
862 if (GST_PAD_ACTIVATEPUSHFUNC (pad)) {
863 if (G_UNLIKELY (!GST_PAD_ACTIVATEPUSHFUNC (pad) (pad, active))) {
867 /* quite ok, element relies on state change func to prepare itself */
870 post_activate (pad, new);
872 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "%s in push mode",
873 active ? "activated" : "deactivated");
878 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "already %s in push mode",
879 active ? "activated" : "deactivated");
884 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
885 "failed to %s in switch to push from mode %d",
886 (active ? "activate" : "deactivate"), old);
891 GST_OBJECT_LOCK (pad);
892 GST_CAT_INFO_OBJECT (GST_CAT_PADS, pad, "failed to %s in push mode",
893 active ? "activate" : "deactivate");
894 GST_PAD_SET_FLUSHING (pad);
895 GST_PAD_ACTIVATE_MODE (pad) = old;
896 GST_OBJECT_UNLOCK (pad);
903 * @pad: the #GstPad to query
905 * Query if a pad is active
907 * Returns: TRUE if the pad is active.
912 gst_pad_is_active (GstPad * pad)
914 gboolean result = FALSE;
916 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
918 GST_OBJECT_LOCK (pad);
919 result = GST_PAD_MODE_ACTIVATE (GST_PAD_ACTIVATE_MODE (pad));
920 GST_OBJECT_UNLOCK (pad);
926 * gst_pad_set_blocked_async:
927 * @pad: the #GstPad to block or unblock
928 * @blocked: boolean indicating whether the pad should be blocked or unblocked
929 * @callback: #GstPadBlockCallback that will be called when the
931 * @user_data: user data passed to the callback
933 * Blocks or unblocks the dataflow on a pad. The provided callback
934 * is called when the operation succeeds; this happens right before the next
935 * attempt at pushing a buffer on the pad.
937 * This can take a while as the pad can only become blocked when real dataflow
939 * When the pipeline is stalled, for example in PAUSED, this can
940 * take an indeterminate amount of time.
941 * You can pass NULL as the callback to make this call block. Be careful with
942 * this blocking call as it might not return for reasons stated above.
944 * Returns: TRUE if the pad could be blocked. This function can fail
945 * if wrong parameters were passed or the pad was already in the
951 gst_pad_set_blocked_async (GstPad * pad, gboolean blocked,
952 GstPadBlockCallback callback, gpointer user_data)
954 gboolean was_blocked = FALSE;
956 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
958 GST_OBJECT_LOCK (pad);
960 was_blocked = GST_PAD_IS_BLOCKED (pad);
962 if (G_UNLIKELY (was_blocked == blocked))
963 goto had_right_state;
966 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "blocking pad");
968 GST_OBJECT_FLAG_SET (pad, GST_PAD_BLOCKED);
969 pad->block_callback = callback;
970 pad->block_data = user_data;
972 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "waiting for block");
973 GST_PAD_BLOCK_WAIT (pad);
974 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "blocked");
977 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "unblocking pad");
979 GST_OBJECT_FLAG_UNSET (pad, GST_PAD_BLOCKED);
981 pad->block_callback = callback;
982 pad->block_data = user_data;
984 GST_PAD_BLOCK_BROADCAST (pad);
986 /* no callback, wait for the unblock to happen */
987 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "waiting for unblock");
988 GST_PAD_BLOCK_WAIT (pad);
989 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "unblocked");
992 GST_OBJECT_UNLOCK (pad);
998 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
999 "pad was in right state (%d)", was_blocked);
1000 GST_OBJECT_UNLOCK (pad);
1007 * gst_pad_set_blocked:
1008 * @pad: the #GstPad to block or unblock
1009 * @blocked: boolean indicating we should block or unblock
1011 * Blocks or unblocks the dataflow on a pad. This function is
1012 * a shortcut for gst_pad_set_blocked_async() with a NULL
1015 * Returns: TRUE if the pad could be blocked. This function can fail
1016 * wrong parameters were passed or the pad was already in the
1022 gst_pad_set_blocked (GstPad * pad, gboolean blocked)
1024 return gst_pad_set_blocked_async (pad, blocked, NULL, NULL);
1028 * gst_pad_is_blocked:
1029 * @pad: the #GstPad to query
1031 * Checks if the pad is blocked or not. This function returns the
1032 * last requested state of the pad. It is not certain that the pad
1033 * is actually blocking at this point (see gst_pad_is_blocking()).
1035 * Returns: TRUE if the pad is blocked.
1040 gst_pad_is_blocked (GstPad * pad)
1042 gboolean result = FALSE;
1044 g_return_val_if_fail (GST_IS_PAD (pad), result);
1046 GST_OBJECT_LOCK (pad);
1047 result = GST_OBJECT_FLAG_IS_SET (pad, GST_PAD_BLOCKED);
1048 GST_OBJECT_UNLOCK (pad);
1054 * gst_pad_is_blocking:
1055 * @pad: the #GstPad to query
1057 * Checks if the pad is blocking or not. This is a guaranteed state
1058 * of whether the pad is actually blocking on a #GstBuffer or a #GstEvent.
1060 * Returns: TRUE if the pad is blocking.
1067 gst_pad_is_blocking (GstPad * pad)
1069 gboolean result = FALSE;
1071 g_return_val_if_fail (GST_IS_PAD (pad), result);
1073 GST_OBJECT_LOCK (pad);
1074 /* 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;
1670 psrc = GST_OBJECT_PARENT (src);
1671 psink = GST_OBJECT_PARENT (sink);
1673 /* if one of the pads has no parent, we allow the link */
1674 if (G_UNLIKELY (psrc == NULL || psink == NULL))
1677 /* if the parents are the same, we have a loop */
1678 if (G_UNLIKELY (psrc == psink))
1681 /* if they both have a parent, we check the grandparents. We can not lock
1682 * the parent because we hold on the child (pad) and the locking order is
1683 * parent >> child. */
1684 psrc = GST_OBJECT_PARENT (psrc);
1685 psink = GST_OBJECT_PARENT (psink);
1687 /* if they have grandparents but they are not the same */
1688 if (G_UNLIKELY (psrc != psink))
1689 goto wrong_grandparents;
1696 GST_CAT_DEBUG (GST_CAT_CAPS,
1697 "one of the pads has no parent %" GST_PTR_FORMAT " and %"
1698 GST_PTR_FORMAT, psrc, psink);
1703 GST_CAT_DEBUG (GST_CAT_CAPS, "pads have same parent %" GST_PTR_FORMAT,
1709 GST_CAT_DEBUG (GST_CAT_CAPS,
1710 "pads have different grandparents %" GST_PTR_FORMAT " and %"
1711 GST_PTR_FORMAT, psrc, psink);
1716 /* FIXME leftover from an attempt at refactoring... */
1717 /* call with the two pads unlocked, when this function returns GST_PAD_LINK_OK,
1718 * the two pads will be locked in the srcpad, sinkpad order. */
1719 static GstPadLinkReturn
1720 gst_pad_link_prepare (GstPad * srcpad, GstPad * sinkpad)
1722 /* generic checks */
1723 g_return_val_if_fail (GST_IS_PAD (srcpad), GST_PAD_LINK_REFUSED);
1724 g_return_val_if_fail (GST_IS_PAD (sinkpad), GST_PAD_LINK_REFUSED);
1726 GST_CAT_INFO (GST_CAT_PADS, "trying to link %s:%s and %s:%s",
1727 GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (sinkpad));
1729 GST_OBJECT_LOCK (srcpad);
1731 if (G_UNLIKELY (GST_PAD_DIRECTION (srcpad) != GST_PAD_SRC))
1734 if (G_UNLIKELY (GST_PAD_PEER (srcpad) != NULL))
1735 goto src_was_linked;
1737 GST_OBJECT_LOCK (sinkpad);
1739 if (G_UNLIKELY (GST_PAD_DIRECTION (sinkpad) != GST_PAD_SINK))
1742 if (G_UNLIKELY (GST_PAD_PEER (sinkpad) != NULL))
1743 goto sink_was_linked;
1745 /* check hierarchy, pads can only be linked if the grandparents
1747 if (!gst_pad_link_check_hierarchy (srcpad, sinkpad))
1748 goto wrong_hierarchy;
1750 /* check pad caps for non-empty intersection */
1751 if (!gst_pad_link_check_compatible_unlocked (srcpad, sinkpad))
1754 /* FIXME check pad scheduling for non-empty intersection */
1756 return GST_PAD_LINK_OK;
1760 g_critical ("pad %s is not a source pad", GST_PAD_NAME (srcpad));
1761 GST_OBJECT_UNLOCK (srcpad);
1762 return GST_PAD_LINK_WRONG_DIRECTION;
1766 GST_CAT_INFO (GST_CAT_PADS, "src %s:%s was already linked to %s:%s",
1767 GST_DEBUG_PAD_NAME (srcpad),
1768 GST_DEBUG_PAD_NAME (GST_PAD_PEER (srcpad)));
1769 /* we do not emit a warning in this case because unlinking cannot
1770 * be made MT safe.*/
1771 GST_OBJECT_UNLOCK (srcpad);
1772 return GST_PAD_LINK_WAS_LINKED;
1776 g_critical ("pad %s is not a sink pad", GST_PAD_NAME (sinkpad));
1777 GST_OBJECT_UNLOCK (sinkpad);
1778 GST_OBJECT_UNLOCK (srcpad);
1779 return GST_PAD_LINK_WRONG_DIRECTION;
1783 GST_CAT_INFO (GST_CAT_PADS, "sink %s:%s was already linked to %s:%s",
1784 GST_DEBUG_PAD_NAME (sinkpad),
1785 GST_DEBUG_PAD_NAME (GST_PAD_PEER (sinkpad)));
1786 /* we do not emit a warning in this case because unlinking cannot
1787 * be made MT safe.*/
1788 GST_OBJECT_UNLOCK (sinkpad);
1789 GST_OBJECT_UNLOCK (srcpad);
1790 return GST_PAD_LINK_WAS_LINKED;
1794 GST_CAT_INFO (GST_CAT_PADS, "pads have wrong hierarchy");
1795 GST_OBJECT_UNLOCK (sinkpad);
1796 GST_OBJECT_UNLOCK (srcpad);
1797 return GST_PAD_LINK_WRONG_HIERARCHY;
1801 GST_CAT_INFO (GST_CAT_PADS, "caps are incompatible");
1802 GST_OBJECT_UNLOCK (sinkpad);
1803 GST_OBJECT_UNLOCK (srcpad);
1804 return GST_PAD_LINK_NOFORMAT;
1810 * @srcpad: the source #GstPad to link.
1811 * @sinkpad: the sink #GstPad to link.
1813 * Links the source pad and the sink pad.
1815 * Returns: A result code indicating if the connection worked or
1821 gst_pad_link (GstPad * srcpad, GstPad * sinkpad)
1823 GstPadLinkReturn result;
1825 /* prepare will also lock the two pads */
1826 result = gst_pad_link_prepare (srcpad, sinkpad);
1828 if (result != GST_PAD_LINK_OK)
1829 goto prepare_failed;
1831 /* must set peers before calling the link function */
1832 GST_PAD_PEER (srcpad) = sinkpad;
1833 GST_PAD_PEER (sinkpad) = srcpad;
1835 GST_OBJECT_UNLOCK (sinkpad);
1836 GST_OBJECT_UNLOCK (srcpad);
1838 /* FIXME released the locks here, concurrent thread might link
1839 * something else. */
1840 if (GST_PAD_LINKFUNC (srcpad)) {
1841 /* this one will call the peer link function */
1842 result = GST_PAD_LINKFUNC (srcpad) (srcpad, sinkpad);
1843 } else if (GST_PAD_LINKFUNC (sinkpad)) {
1844 /* if no source link function, we need to call the sink link
1845 * function ourselves. */
1846 result = GST_PAD_LINKFUNC (sinkpad) (sinkpad, srcpad);
1848 result = GST_PAD_LINK_OK;
1851 GST_OBJECT_LOCK (srcpad);
1852 GST_OBJECT_LOCK (sinkpad);
1854 if (result == GST_PAD_LINK_OK) {
1855 GST_OBJECT_UNLOCK (sinkpad);
1856 GST_OBJECT_UNLOCK (srcpad);
1858 /* fire off a signal to each of the pads telling them
1859 * that they've been linked */
1860 g_signal_emit (G_OBJECT (srcpad), gst_pad_signals[PAD_LINKED], 0, sinkpad);
1861 g_signal_emit (G_OBJECT (sinkpad), gst_pad_signals[PAD_LINKED], 0, srcpad);
1863 GST_CAT_INFO (GST_CAT_PADS, "linked %s:%s and %s:%s, successful",
1864 GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (sinkpad));
1866 GST_CAT_INFO (GST_CAT_PADS, "link between %s:%s and %s:%s failed",
1867 GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (sinkpad));
1869 GST_PAD_PEER (srcpad) = NULL;
1870 GST_PAD_PEER (sinkpad) = NULL;
1872 GST_OBJECT_UNLOCK (sinkpad);
1873 GST_OBJECT_UNLOCK (srcpad);
1884 gst_pad_set_pad_template (GstPad * pad, GstPadTemplate * templ)
1886 GstPadTemplate **template_p;
1888 /* this function would need checks if it weren't static */
1890 GST_OBJECT_LOCK (pad);
1891 template_p = &pad->padtemplate;
1892 gst_object_replace ((GstObject **) template_p, (GstObject *) templ);
1893 GST_OBJECT_UNLOCK (pad);
1896 gst_pad_template_pad_created (templ, pad);
1900 * gst_pad_get_pad_template:
1903 * Gets the template for @pad.
1905 * Returns: the #GstPadTemplate from which this pad was instantiated, or %NULL
1906 * if this pad has no template.
1908 * FIXME: currently returns an unrefcounted padtemplate.
1911 gst_pad_get_pad_template (GstPad * pad)
1913 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
1915 return GST_PAD_PAD_TEMPLATE (pad);
1919 /* should be called with the pad LOCK held */
1920 /* refs the caps, so caller is responsible for getting it unreffed */
1922 gst_pad_get_caps_unlocked (GstPad * pad)
1924 GstCaps *result = NULL;
1926 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "get pad caps");
1928 if (GST_PAD_GETCAPSFUNC (pad)) {
1929 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
1930 "dispatching to pad getcaps function");
1932 GST_OBJECT_FLAG_SET (pad, GST_PAD_IN_GETCAPS);
1933 GST_OBJECT_UNLOCK (pad);
1934 result = GST_PAD_GETCAPSFUNC (pad) (pad);
1935 GST_OBJECT_LOCK (pad);
1936 GST_OBJECT_FLAG_UNSET (pad, GST_PAD_IN_GETCAPS);
1938 if (result == NULL) {
1939 g_critical ("pad %s:%s returned NULL caps from getcaps function",
1940 GST_DEBUG_PAD_NAME (pad));
1942 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
1943 "pad getcaps returned %" GST_PTR_FORMAT, result);
1944 #ifndef G_DISABLE_ASSERT
1945 /* check that the returned caps are a real subset of the template caps */
1946 if (GST_PAD_PAD_TEMPLATE (pad)) {
1947 const GstCaps *templ_caps =
1948 GST_PAD_TEMPLATE_CAPS (GST_PAD_PAD_TEMPLATE (pad));
1949 if (!gst_caps_is_subset (result, templ_caps)) {
1952 GST_CAT_ERROR_OBJECT (GST_CAT_CAPS, pad,
1953 "pad returned caps %" GST_PTR_FORMAT
1954 " which are not a real subset of its template caps %"
1955 GST_PTR_FORMAT, result, templ_caps);
1957 ("pad %s:%s returned caps which are not a real "
1958 "subset of its template caps", GST_DEBUG_PAD_NAME (pad));
1959 temp = gst_caps_intersect (templ_caps, result);
1960 gst_caps_unref (result);
1968 if (GST_PAD_PAD_TEMPLATE (pad)) {
1969 GstPadTemplate *templ = GST_PAD_PAD_TEMPLATE (pad);
1971 result = GST_PAD_TEMPLATE_CAPS (templ);
1972 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
1973 "using pad template %p with caps %p %" GST_PTR_FORMAT, templ, result,
1976 result = gst_caps_ref (result);
1979 if (GST_PAD_CAPS (pad)) {
1980 result = GST_PAD_CAPS (pad);
1982 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
1983 "using pad caps %p %" GST_PTR_FORMAT, result, result);
1985 result = gst_caps_ref (result);
1989 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "pad has no caps");
1990 result = gst_caps_new_empty ();
1998 * @pad: a #GstPad to get the capabilities of.
2000 * Gets the capabilities this pad can produce or consume.
2001 * Note that this method doesn't necessarily return the caps set by
2002 * gst_pad_set_caps() - use #GST_PAD_CAPS for that instead.
2003 * gst_pad_get_caps returns all possible caps a pad can operate with, using
2004 * the pad's get_caps function;
2005 * this returns the pad template caps if not explicitly set.
2007 * Returns: a newly allocated copy of the #GstCaps of this pad.
2012 gst_pad_get_caps (GstPad * pad)
2014 GstCaps *result = NULL;
2016 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2018 GST_OBJECT_LOCK (pad);
2020 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "get pad caps");
2022 result = gst_pad_get_caps_unlocked (pad);
2023 GST_OBJECT_UNLOCK (pad);
2029 * gst_pad_peer_get_caps:
2030 * @pad: a #GstPad to get the peer capabilities of.
2032 * Gets the capabilities of the peer connected to this pad.
2034 * Returns: the #GstCaps of the peer pad. This function returns a new caps, so use
2035 * gst_caps_unref to get rid of it. this function returns NULL if there is no
2039 gst_pad_peer_get_caps (GstPad * pad)
2042 GstCaps *result = NULL;
2044 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2046 GST_OBJECT_LOCK (pad);
2048 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "get peer caps");
2050 peerpad = GST_PAD_PEER (pad);
2051 if (G_UNLIKELY (peerpad == NULL))
2054 gst_object_ref (peerpad);
2055 GST_OBJECT_UNLOCK (pad);
2057 result = gst_pad_get_caps (peerpad);
2059 gst_object_unref (peerpad);
2065 GST_OBJECT_UNLOCK (pad);
2071 fixate_value (GValue * dest, const GValue * src)
2073 if (G_VALUE_TYPE (src) == GST_TYPE_INT_RANGE) {
2074 g_value_init (dest, G_TYPE_INT);
2075 g_value_set_int (dest, gst_value_get_int_range_min (src));
2076 } else if (G_VALUE_TYPE (src) == GST_TYPE_DOUBLE_RANGE) {
2077 g_value_init (dest, G_TYPE_DOUBLE);
2078 g_value_set_double (dest, gst_value_get_double_range_min (src));
2079 } else if (G_VALUE_TYPE (src) == GST_TYPE_FRACTION_RANGE) {
2080 gst_value_init_and_copy (dest, gst_value_get_fraction_range_min (src));
2081 } else if (G_VALUE_TYPE (src) == GST_TYPE_LIST) {
2082 GValue temp = { 0 };
2084 gst_value_init_and_copy (&temp, gst_value_list_get_value (src, 0));
2085 if (!fixate_value (dest, &temp))
2086 gst_value_init_and_copy (dest, &temp);
2087 g_value_unset (&temp);
2088 } else if (G_VALUE_TYPE (src) == GST_TYPE_ARRAY) {
2089 gboolean res = FALSE;
2092 g_value_init (dest, GST_TYPE_ARRAY);
2093 for (n = 0; n < gst_value_array_get_size (src); n++) {
2095 const GValue *orig_kid = gst_value_array_get_value (src, n);
2097 if (!fixate_value (&kid, orig_kid))
2098 gst_value_init_and_copy (&kid, orig_kid);
2101 gst_value_array_append_value (dest, &kid);
2102 g_value_unset (&kid);
2106 g_value_unset (dest);
2117 gst_pad_default_fixate (GQuark field_id, const GValue * value, gpointer data)
2119 GstStructure *s = data;
2122 if (fixate_value (&v, value)) {
2123 gst_structure_id_set_value (s, field_id, &v);
2131 * gst_pad_fixate_caps:
2132 * @pad: a #GstPad to fixate
2133 * @caps: the #GstCaps to fixate
2135 * Fixate a caps on the given pad. Modifies the caps in place, so you should
2136 * make sure that the caps are actually writable (see gst_caps_make_writable()).
2139 gst_pad_fixate_caps (GstPad * pad, GstCaps * caps)
2141 GstPadFixateCapsFunction fixatefunc;
2144 g_return_if_fail (GST_IS_PAD (pad));
2145 g_return_if_fail (caps != NULL);
2147 if (gst_caps_is_fixed (caps))
2150 fixatefunc = GST_PAD_FIXATECAPSFUNC (pad);
2152 fixatefunc (pad, caps);
2155 /* default fixation */
2156 for (n = 0; n < gst_caps_get_size (caps); n++) {
2157 GstStructure *s = gst_caps_get_structure (caps, n);
2159 gst_structure_foreach (s, gst_pad_default_fixate, s);
2163 /* Default accept caps implementation just checks against
2164 * against the allowed caps for the pad */
2166 gst_pad_acceptcaps_default (GstPad * pad, GstCaps * caps)
2168 /* get the caps and see if it intersects to something
2172 gboolean result = FALSE;
2174 allowed = gst_pad_get_caps (pad);
2176 goto nothing_allowed;
2178 intersect = gst_caps_intersect (allowed, caps);
2180 result = !gst_caps_is_empty (intersect);
2182 GST_DEBUG_OBJECT (pad, "intersection gave empty caps");
2184 gst_caps_unref (allowed);
2185 gst_caps_unref (intersect);
2192 GST_DEBUG_OBJECT (pad, "no caps allowed on the pad");
2198 * gst_pad_accept_caps:
2199 * @pad: a #GstPad to check
2200 * @caps: a #GstCaps to check on the pad
2202 * Check if the given pad accepts the caps.
2204 * Returns: TRUE if the pad can accept the caps.
2207 gst_pad_accept_caps (GstPad * pad, GstCaps * caps)
2210 GstPadAcceptCapsFunction acceptfunc;
2211 GstCaps *existing = NULL;
2213 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2215 /* any pad can be unnegotiated */
2219 /* lock for checking the existing caps */
2220 GST_OBJECT_LOCK (pad);
2221 acceptfunc = GST_PAD_ACCEPTCAPSFUNC (pad);
2222 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "accept caps of %p", caps);
2223 /* The current caps on a pad are trivially acceptable */
2224 if (G_LIKELY ((existing = GST_PAD_CAPS (pad)))) {
2225 if (caps == existing || gst_caps_is_equal (caps, existing))
2228 GST_OBJECT_UNLOCK (pad);
2230 if (G_LIKELY (acceptfunc)) {
2231 /* we can call the function */
2232 result = acceptfunc (pad, caps);
2233 GST_DEBUG_OBJECT (pad, "acceptfunc returned %d", result);
2235 /* Only null if the element explicitly unset it */
2236 result = gst_pad_acceptcaps_default (pad, caps);
2237 GST_DEBUG_OBJECT (pad, "default acceptcaps returned %d", result);
2243 GST_DEBUG_OBJECT (pad, "pad had same caps");
2244 GST_OBJECT_UNLOCK (pad);
2250 * gst_pad_peer_accept_caps:
2251 * @pad: a #GstPad to check the peer of
2252 * @caps: a #GstCaps to check on the pad
2254 * Check if the peer of @pad accepts @caps. If @pad has no peer, this function
2257 * Returns: TRUE if the peer of @pad can accept the caps or @pad has no peer.
2260 gst_pad_peer_accept_caps (GstPad * pad, GstCaps * caps)
2265 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2267 GST_OBJECT_LOCK (pad);
2269 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "peer accept caps of (%p)", pad);
2271 peerpad = GST_PAD_PEER (pad);
2272 if (G_UNLIKELY (peerpad == NULL))
2275 result = gst_pad_accept_caps (peerpad, caps);
2276 GST_OBJECT_UNLOCK (pad);
2282 GST_OBJECT_UNLOCK (pad);
2289 * @pad: a #GstPad to set the capabilities of.
2290 * @caps: a #GstCaps to set.
2292 * Sets the capabilities of this pad. The caps must be fixed. Any previous
2293 * caps on the pad will be unreffed. This function refs the caps so you should
2294 * unref if as soon as you don't need it anymore.
2295 * It is possible to set NULL caps, which will make the pad unnegotiated
2298 * Returns: TRUE if the caps could be set. FALSE if the caps were not fixed
2299 * or bad parameters were provided to this function.
2304 gst_pad_set_caps (GstPad * pad, GstCaps * caps)
2306 GstPadSetCapsFunction setcaps;
2309 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2310 g_return_val_if_fail (caps == NULL || gst_caps_is_fixed (caps), FALSE);
2312 GST_OBJECT_LOCK (pad);
2313 existing = GST_PAD_CAPS (pad);
2314 if (existing == caps)
2317 if (gst_caps_is_equal (caps, existing))
2318 goto setting_same_caps;
2320 setcaps = GST_PAD_SETCAPSFUNC (pad);
2322 /* call setcaps function to configure the pad only if the
2323 * caps is not NULL */
2324 if (setcaps != NULL && caps) {
2325 if (!GST_PAD_IS_IN_SETCAPS (pad)) {
2326 GST_OBJECT_FLAG_SET (pad, GST_PAD_IN_SETCAPS);
2327 GST_OBJECT_UNLOCK (pad);
2328 if (!setcaps (pad, caps))
2330 GST_OBJECT_LOCK (pad);
2331 GST_OBJECT_FLAG_UNSET (pad, GST_PAD_IN_SETCAPS);
2333 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "pad was dispatching");
2337 gst_caps_replace (&GST_PAD_CAPS (pad), caps);
2338 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "caps %" GST_PTR_FORMAT, caps);
2339 GST_OBJECT_UNLOCK (pad);
2341 g_object_notify (G_OBJECT (pad), "caps");
2347 GST_OBJECT_UNLOCK (pad);
2352 gst_caps_replace (&GST_PAD_CAPS (pad), caps);
2353 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
2354 "caps %" GST_PTR_FORMAT " same as existing, updating ptr only", caps);
2355 GST_OBJECT_UNLOCK (pad);
2362 GST_OBJECT_LOCK (pad);
2363 GST_OBJECT_FLAG_UNSET (pad, GST_PAD_IN_SETCAPS);
2364 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
2365 "caps %" GST_PTR_FORMAT " could not be set", caps);
2366 GST_OBJECT_UNLOCK (pad);
2373 gst_pad_configure_sink (GstPad * pad, GstCaps * caps)
2375 GstPadSetCapsFunction setcaps;
2378 setcaps = GST_PAD_SETCAPSFUNC (pad);
2380 /* See if pad accepts the caps - only needed if
2381 * no setcaps function */
2382 if (setcaps == NULL)
2383 if (!gst_pad_accept_caps (pad, caps))
2386 /* set caps on pad if call succeeds */
2387 res = gst_pad_set_caps (pad, caps);
2388 /* no need to unref the caps here, set_caps takes a ref and
2389 * our ref goes away when we leave this function. */
2395 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
2396 "caps %" GST_PTR_FORMAT " not accepted", caps);
2401 /* returns TRUE if the src pad could be configured to accept the given caps */
2403 gst_pad_configure_src (GstPad * pad, GstCaps * caps, gboolean dosetcaps)
2405 GstPadSetCapsFunction setcaps;
2408 setcaps = GST_PAD_SETCAPSFUNC (pad);
2410 /* See if pad accepts the caps - only needed if
2411 * no setcaps function */
2412 if (setcaps == NULL)
2413 if (!gst_pad_accept_caps (pad, caps))
2417 res = gst_pad_set_caps (pad, caps);
2425 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
2426 "caps %" GST_PTR_FORMAT " not accepted", caps);
2432 * gst_pad_get_pad_template_caps:
2433 * @pad: a #GstPad to get the template capabilities from.
2435 * Gets the capabilities for @pad's template.
2437 * Returns: the #GstCaps of this pad template. If you intend to keep a reference
2438 * on the caps, make a copy (see gst_caps_copy ()).
2441 gst_pad_get_pad_template_caps (GstPad * pad)
2443 static GstStaticCaps anycaps = GST_STATIC_CAPS ("ANY");
2445 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2447 if (GST_PAD_PAD_TEMPLATE (pad))
2448 return GST_PAD_TEMPLATE_CAPS (GST_PAD_PAD_TEMPLATE (pad));
2450 return gst_static_caps_get (&anycaps);
2456 * @pad: a #GstPad to get the peer of.
2458 * Gets the peer of @pad. This function refs the peer pad so
2459 * you need to unref it after use.
2461 * Returns: the peer #GstPad. Unref after usage.
2466 gst_pad_get_peer (GstPad * pad)
2470 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2472 GST_OBJECT_LOCK (pad);
2473 result = GST_PAD_PEER (pad);
2475 gst_object_ref (result);
2476 GST_OBJECT_UNLOCK (pad);
2482 * gst_pad_get_allowed_caps:
2483 * @srcpad: a #GstPad, it must a a source pad.
2485 * Gets the capabilities of the allowed media types that can flow through
2486 * @srcpad and its peer. The pad must be a source pad.
2487 * The caller must free the resulting caps.
2489 * Returns: the allowed #GstCaps of the pad link. Free the caps when
2490 * you no longer need it. This function returns NULL when the @srcpad has no
2496 gst_pad_get_allowed_caps (GstPad * srcpad)
2503 g_return_val_if_fail (GST_IS_PAD (srcpad), NULL);
2504 g_return_val_if_fail (GST_PAD_IS_SRC (srcpad), NULL);
2506 GST_OBJECT_LOCK (srcpad);
2508 peer = GST_PAD_PEER (srcpad);
2509 if (G_UNLIKELY (peer == NULL))
2512 GST_CAT_DEBUG_OBJECT (GST_CAT_PROPERTIES, srcpad, "getting allowed caps");
2514 gst_object_ref (peer);
2515 GST_OBJECT_UNLOCK (srcpad);
2516 mycaps = gst_pad_get_caps (srcpad);
2518 peercaps = gst_pad_get_caps (peer);
2519 gst_object_unref (peer);
2521 caps = gst_caps_intersect (mycaps, peercaps);
2522 gst_caps_unref (peercaps);
2523 gst_caps_unref (mycaps);
2525 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, srcpad, "allowed caps %" GST_PTR_FORMAT,
2532 GST_CAT_DEBUG_OBJECT (GST_CAT_PROPERTIES, srcpad, "no peer");
2533 GST_OBJECT_UNLOCK (srcpad);
2540 * gst_pad_get_negotiated_caps:
2543 * Gets the capabilities of the media type that currently flows through @pad
2546 * This function can be used on both src and sinkpads. Note that srcpads are
2547 * always negotiated before sinkpads so it is possible that the negotiated caps
2548 * on the srcpad do not match the negotiated caps of the peer.
2550 * Returns: the negotiated #GstCaps of the pad link. Free the caps when
2551 * you no longer need it. This function returns NULL when the @pad has no
2552 * peer or is not negotiated yet.
2557 gst_pad_get_negotiated_caps (GstPad * pad)
2562 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2564 GST_OBJECT_LOCK (pad);
2566 if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
2569 GST_CAT_DEBUG_OBJECT (GST_CAT_PROPERTIES, pad, "getting negotiated caps");
2571 caps = GST_PAD_CAPS (pad);
2573 gst_caps_ref (caps);
2574 GST_OBJECT_UNLOCK (pad);
2576 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "negotiated caps %" GST_PTR_FORMAT,
2583 GST_CAT_DEBUG_OBJECT (GST_CAT_PROPERTIES, pad, "no peer");
2584 GST_OBJECT_UNLOCK (pad);
2590 /* calls the buffer_alloc function on the given pad */
2591 static GstFlowReturn
2592 gst_pad_buffer_alloc_unchecked (GstPad * pad, guint64 offset, gint size,
2593 GstCaps * caps, GstBuffer ** buf)
2596 GstPadBufferAllocFunction bufferallocfunc;
2598 GST_OBJECT_LOCK (pad);
2599 /* when the pad is flushing we cannot give a buffer */
2600 if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad)))
2603 bufferallocfunc = pad->bufferallocfunc;
2605 if (offset == GST_BUFFER_OFFSET_NONE) {
2606 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
2607 "calling bufferallocfunc &%s (@%p) for size %d offset NONE",
2608 GST_DEBUG_FUNCPTR_NAME (bufferallocfunc), bufferallocfunc, size);
2610 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
2611 "calling bufferallocfunc &%s (@%p) of for size %d offset %"
2612 G_GUINT64_FORMAT, GST_DEBUG_FUNCPTR_NAME (bufferallocfunc),
2613 bufferallocfunc, size, offset);
2615 GST_OBJECT_UNLOCK (pad);
2617 /* G_LIKELY for now since most elements don't implement a buffer alloc
2618 * function and there is no default alloc proxy function as this is usually
2620 if (G_LIKELY (bufferallocfunc == NULL))
2623 ret = bufferallocfunc (pad, offset, size, caps, buf);
2624 if (G_UNLIKELY (ret != GST_FLOW_OK))
2626 /* no error, but NULL buffer means fallback to the default */
2627 if (G_UNLIKELY (*buf == NULL))
2630 /* If the buffer alloc function didn't set up the caps like it should,
2632 if (G_UNLIKELY (caps && (GST_BUFFER_CAPS (*buf) == NULL))) {
2633 GST_WARNING_OBJECT (pad,
2634 "Buffer allocation function did not set caps. Setting");
2635 gst_buffer_set_caps (*buf, caps);
2641 /* pad was flushing */
2642 GST_OBJECT_UNLOCK (pad);
2643 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "pad was flushing");
2644 return GST_FLOW_WRONG_STATE;
2648 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
2649 "alloc function returned error (%d) %s", ret, gst_flow_get_name (ret));
2654 /* fallback case, allocate a buffer of our own, add pad caps. */
2655 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "fallback buffer alloc");
2657 *buf = gst_buffer_new_and_alloc (size);
2658 GST_BUFFER_OFFSET (*buf) = offset;
2659 gst_buffer_set_caps (*buf, caps);
2665 static GstFlowReturn
2666 gst_pad_alloc_buffer_full (GstPad * pad, guint64 offset, gint size,
2667 GstCaps * caps, GstBuffer ** buf, gboolean setcaps)
2671 gboolean caps_changed;
2673 g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
2674 g_return_val_if_fail (GST_PAD_IS_SRC (pad), GST_FLOW_ERROR);
2675 g_return_val_if_fail (buf != NULL, GST_FLOW_ERROR);
2677 GST_OBJECT_LOCK (pad);
2678 while (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad)))
2679 if ((ret = handle_pad_block (pad)) != GST_FLOW_OK)
2682 if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
2685 gst_object_ref (peer);
2686 GST_OBJECT_UNLOCK (pad);
2688 ret = gst_pad_buffer_alloc_unchecked (peer, offset, size, caps, buf);
2689 gst_object_unref (peer);
2691 if (G_UNLIKELY (ret != GST_FLOW_OK))
2694 /* FIXME, move capnego this into a base class? */
2695 caps = GST_BUFFER_CAPS (*buf);
2697 /* Lock for checking caps, pretty pointless as the _pad_push() function might
2698 * change it concurrently, one of the problems with automatic caps setting in
2699 * pad_alloc_and_set_caps. Worst case, if does a check too much, but only when
2700 * there is heavy renegotiation going on in both directions. */
2701 GST_OBJECT_LOCK (pad);
2702 caps_changed = caps && caps != GST_PAD_CAPS (pad);
2703 GST_OBJECT_UNLOCK (pad);
2705 /* we got a new datatype on the pad, see if it can handle it */
2706 if (G_UNLIKELY (caps_changed)) {
2707 GST_DEBUG_OBJECT (pad, "caps changed to %p %" GST_PTR_FORMAT, caps, caps);
2708 if (G_UNLIKELY (!gst_pad_configure_src (pad, caps, setcaps)))
2709 goto not_negotiated;
2715 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "pad block stopped by flush");
2716 GST_OBJECT_UNLOCK (pad);
2721 /* pad has no peer */
2722 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
2723 "called bufferallocfunc but had no peer");
2724 GST_OBJECT_UNLOCK (pad);
2725 return GST_FLOW_NOT_LINKED;
2729 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
2730 "alloc function returned error %s", gst_flow_get_name (ret));
2735 gst_buffer_unref (*buf);
2737 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
2738 "alloc function returned unacceptable buffer");
2739 return GST_FLOW_NOT_NEGOTIATED;
2744 * gst_pad_alloc_buffer:
2745 * @pad: a source #GstPad
2746 * @offset: the offset of the new buffer in the stream
2747 * @size: the size of the new buffer
2748 * @caps: the caps of the new buffer
2749 * @buf: a newly allocated buffer
2751 * Allocates a new, empty buffer optimized to push to pad @pad. This
2752 * function only works if @pad is a source pad and has a peer.
2754 * A new, empty #GstBuffer will be put in the @buf argument.
2755 * You need to check the caps of the buffer after performing this
2756 * function and renegotiate to the format if needed.
2758 * Returns: a result code indicating success of the operation. Any
2759 * result code other than #GST_FLOW_OK is an error and @buf should
2761 * An error can occur if the pad is not connected or when the downstream
2762 * peer elements cannot provide an acceptable buffer.
2767 gst_pad_alloc_buffer (GstPad * pad, guint64 offset, gint size, GstCaps * caps,
2770 return gst_pad_alloc_buffer_full (pad, offset, size, caps, buf, FALSE);
2774 * gst_pad_alloc_buffer_and_set_caps:
2775 * @pad: a source #GstPad
2776 * @offset: the offset of the new buffer in the stream
2777 * @size: the size of the new buffer
2778 * @caps: the caps of the new buffer
2779 * @buf: a newly allocated buffer
2781 * In addition to the function gst_pad_alloc_buffer(), this function
2782 * automatically calls gst_pad_set_caps() when the caps of the
2783 * newly allocated buffer are different from the @pad caps.
2785 * Returns: a result code indicating success of the operation. Any
2786 * result code other than #GST_FLOW_OK is an error and @buf should
2788 * An error can occur if the pad is not connected or when the downstream
2789 * peer elements cannot provide an acceptable buffer.
2794 gst_pad_alloc_buffer_and_set_caps (GstPad * pad, guint64 offset, gint size,
2795 GstCaps * caps, GstBuffer ** buf)
2797 return gst_pad_alloc_buffer_full (pad, offset, size, caps, buf, TRUE);
2801 * gst_pad_get_internal_links_default:
2802 * @pad: the #GstPad to get the internal links of.
2804 * Gets a list of pads to which the given pad is linked to
2805 * inside of the parent element.
2806 * This is the default handler, and thus returns a list of all of the
2807 * pads inside the parent element with opposite direction.
2808 * The caller must free this list after use.
2810 * Returns: a newly allocated #GList of pads, or NULL if the pad has no parent.
2815 gst_pad_get_internal_links_default (GstPad * pad)
2820 GstPadDirection direction;
2822 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2824 direction = pad->direction;
2826 parent = GST_PAD_PARENT (pad);
2830 parent_pads = parent->pads;
2832 while (parent_pads) {
2833 GstPad *parent_pad = GST_PAD_CAST (parent_pads->data);
2835 if (parent_pad->direction != direction) {
2836 res = g_list_prepend (res, parent_pad);
2839 parent_pads = g_list_next (parent_pads);
2846 * gst_pad_get_internal_links:
2847 * @pad: the #GstPad to get the internal links of.
2849 * Gets a list of pads to which the given pad is linked to
2850 * inside of the parent element.
2851 * The caller must free this list after use.
2853 * Returns: a newly allocated #GList of pads.
2858 gst_pad_get_internal_links (GstPad * pad)
2862 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2864 if (GST_PAD_INTLINKFUNC (pad))
2865 res = GST_PAD_INTLINKFUNC (pad) (pad);
2872 gst_pad_event_default_dispatch (GstPad * pad, GstEvent * event)
2877 GST_INFO_OBJECT (pad, "Sending event %p (%s) to all internally linked pads",
2878 event, GST_EVENT_TYPE_NAME (event));
2880 result = (GST_PAD_DIRECTION (pad) == GST_PAD_SINK);
2882 orig = pads = gst_pad_get_internal_links (pad);
2885 GstPad *eventpad = GST_PAD_CAST (pads->data);
2887 pads = g_list_next (pads);
2889 if (GST_PAD_DIRECTION (eventpad) == GST_PAD_SRC) {
2890 /* for each pad we send to, we should ref the event; it's up
2891 * to downstream to unref again when handled. */
2892 GST_LOG_OBJECT (pad, "Reffing and sending event %p (%s) to %s:%s",
2893 event, GST_EVENT_TYPE_NAME (event), GST_DEBUG_PAD_NAME (eventpad));
2894 gst_event_ref (event);
2895 gst_pad_push_event (eventpad, event);
2897 /* we only send the event on one pad, multi-sinkpad elements
2898 * should implement a handler */
2899 GST_LOG_OBJECT (pad, "sending event %p (%s) to one sink pad %s:%s",
2900 event, GST_EVENT_TYPE_NAME (event), GST_DEBUG_PAD_NAME (eventpad));
2901 result = gst_pad_push_event (eventpad, event);
2905 /* we handled the incoming event so we unref once */
2906 GST_LOG_OBJECT (pad, "handled event %p, unreffing", event);
2907 gst_event_unref (event);
2916 * gst_pad_event_default:
2917 * @pad: a #GstPad to call the default event handler on.
2918 * @event: the #GstEvent to handle.
2920 * Invokes the default event handler for the given pad. End-of-stream and
2921 * discontinuity events are handled specially, and then the event is sent to all
2922 * pads internally linked to @pad. Note that if there are many possible sink
2923 * pads that are internally linked to @pad, only one will be sent an event.
2924 * Multi-sinkpad elements should implement custom event handlers.
2926 * Returns: TRUE if the event was sent succesfully.
2929 gst_pad_event_default (GstPad * pad, GstEvent * event)
2931 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2932 g_return_val_if_fail (event != NULL, FALSE);
2934 switch (GST_EVENT_TYPE (event)) {
2937 GST_DEBUG_OBJECT (pad, "pausing task because of eos");
2938 gst_pad_pause_task (pad);
2944 return gst_pad_event_default_dispatch (pad, event);
2948 * gst_pad_dispatcher:
2949 * @pad: a #GstPad to dispatch.
2950 * @dispatch: the #GstDispatcherFunction to call.
2951 * @data: gpointer user data passed to the dispatcher function.
2953 * Invokes the given dispatcher function on each respective peer of
2954 * all pads that are internally linked to the given pad.
2955 * The GstPadDispatcherFunction should return TRUE when no further pads
2956 * need to be processed.
2958 * Returns: TRUE if one of the dispatcher functions returned TRUE.
2961 gst_pad_dispatcher (GstPad * pad, GstPadDispatcherFunction dispatch,
2964 gboolean res = FALSE;
2965 GList *int_pads, *orig;
2967 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2968 g_return_val_if_fail (dispatch != NULL, FALSE);
2970 orig = int_pads = gst_pad_get_internal_links (pad);
2973 GstPad *int_pad = GST_PAD_CAST (int_pads->data);
2974 GstPad *int_peer = GST_PAD_PEER (int_pad);
2977 res = dispatch (int_peer, data);
2981 int_pads = g_list_next (int_pads);
2991 * @pad: a #GstPad to invoke the default query on.
2992 * @query: the #GstQuery to perform.
2994 * Dispatches a query to a pad. The query should have been allocated by the
2995 * caller via one of the type-specific allocation functions in gstquery.h. The
2996 * element is responsible for filling the query with an appropriate response,
2997 * which should then be parsed with a type-specific query parsing function.
2999 * Again, the caller is responsible for both the allocation and deallocation of
3000 * the query structure.
3002 * Returns: TRUE if the query could be performed.
3005 gst_pad_query (GstPad * pad, GstQuery * query)
3007 GstPadQueryFunction func;
3009 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
3010 g_return_val_if_fail (GST_IS_QUERY (query), FALSE);
3012 GST_DEBUG_OBJECT (pad, "sending query %p", query);
3014 if ((func = GST_PAD_QUERYFUNC (pad)) == NULL)
3017 return func (pad, query);
3021 GST_DEBUG_OBJECT (pad, "had no query function");
3027 * gst_pad_query_default:
3028 * @pad: a #GstPad to call the default query handler on.
3029 * @query: the #GstQuery to handle.
3031 * Invokes the default query handler for the given pad.
3032 * The query is sent to all pads internally linked to @pad. Note that
3033 * if there are many possible sink pads that are internally linked to
3034 * @pad, only one will be sent the query.
3035 * Multi-sinkpad elements should implement custom query handlers.
3037 * Returns: TRUE if the query was performed succesfully.
3040 gst_pad_query_default (GstPad * pad, GstQuery * query)
3042 switch (GST_QUERY_TYPE (query)) {
3043 case GST_QUERY_POSITION:
3044 case GST_QUERY_SEEKING:
3045 case GST_QUERY_FORMATS:
3046 case GST_QUERY_LATENCY:
3047 case GST_QUERY_JITTER:
3048 case GST_QUERY_RATE:
3049 case GST_QUERY_CONVERT:
3051 return gst_pad_dispatcher
3052 (pad, (GstPadDispatcherFunction) gst_pad_query, query);
3056 #ifndef GST_DISABLE_LOADSAVE
3057 /* FIXME: why isn't this on a GstElement ? */
3059 * gst_pad_load_and_link:
3060 * @self: an #xmlNodePtr to read the description from.
3061 * @parent: the #GstObject element that owns the pad.
3063 * Reads the pad definition from the XML node and links the given pad
3064 * in the element to a pad of an element up in the hierarchy.
3067 gst_pad_load_and_link (xmlNodePtr self, GstObject * parent)
3069 xmlNodePtr field = self->xmlChildrenNode;
3070 GstPad *pad = NULL, *targetpad;
3074 GstObject *grandparent;
3078 if (!strcmp ((char *) field->name, "name")) {
3079 name = (gchar *) xmlNodeGetContent (field);
3080 pad = gst_element_get_pad (GST_ELEMENT (parent), name);
3082 } else if (!strcmp ((char *) field->name, "peer")) {
3083 peer = (gchar *) xmlNodeGetContent (field);
3085 field = field->next;
3087 g_return_if_fail (pad != NULL);
3092 split = g_strsplit (peer, ".", 2);
3094 if (split[0] == NULL || split[1] == NULL) {
3095 GST_CAT_DEBUG_OBJECT (GST_CAT_XML, pad,
3096 "Could not parse peer '%s', leaving unlinked", peer);
3103 g_return_if_fail (split[0] != NULL);
3104 g_return_if_fail (split[1] != NULL);
3106 grandparent = gst_object_get_parent (parent);
3108 if (grandparent && GST_IS_BIN (grandparent)) {
3109 target = gst_bin_get_by_name_recurse_up (GST_BIN (grandparent), split[0]);
3116 targetpad = gst_element_get_pad (target, split[1]);
3118 if (targetpad == NULL)
3121 gst_pad_link (pad, targetpad);
3128 * gst_pad_save_thyself:
3129 * @pad: a #GstPad to save.
3130 * @parent: the parent #xmlNodePtr to save the description in.
3132 * Saves the pad into an xml representation.
3134 * Returns: the #xmlNodePtr representation of the pad.
3137 gst_pad_save_thyself (GstObject * object, xmlNodePtr parent)
3142 g_return_val_if_fail (GST_IS_PAD (object), NULL);
3144 pad = GST_PAD (object);
3146 xmlNewChild (parent, NULL, (xmlChar *) "name",
3147 (xmlChar *) GST_PAD_NAME (pad));
3149 if (GST_PAD_IS_SRC (pad)) {
3150 xmlNewChild (parent, NULL, (xmlChar *) "direction", (xmlChar *) "source");
3151 } else if (GST_PAD_IS_SINK (pad)) {
3152 xmlNewChild (parent, NULL, (xmlChar *) "direction", (xmlChar *) "sink");
3154 xmlNewChild (parent, NULL, (xmlChar *) "direction", (xmlChar *) "unknown");
3157 if (GST_PAD_PEER (pad) != NULL) {
3160 peer = GST_PAD_PEER (pad);
3161 /* first check to see if the peer's parent's parent is the same */
3162 /* we just save it off */
3163 content = g_strdup_printf ("%s.%s",
3164 GST_OBJECT_NAME (GST_PAD_PARENT (peer)), GST_PAD_NAME (peer));
3165 xmlNewChild (parent, NULL, (xmlChar *) "peer", (xmlChar *) content);
3168 xmlNewChild (parent, NULL, (xmlChar *) "peer", NULL);
3175 * gst_ghost_pad_save_thyself:
3176 * @pad: a ghost #GstPad to save.
3177 * @parent: the parent #xmlNodePtr to save the description in.
3179 * Saves the ghost pad into an xml representation.
3181 * Returns: the #xmlNodePtr representation of the pad.
3184 gst_ghost_pad_save_thyself (GstPad * pad, xmlNodePtr parent)
3188 g_return_val_if_fail (GST_IS_GHOST_PAD (pad), NULL);
3190 self = xmlNewChild (parent, NULL, (xmlChar *) "ghostpad", NULL);
3191 xmlNewChild (self, NULL, (xmlChar *) "name", (xmlChar *) GST_PAD_NAME (pad));
3192 xmlNewChild (self, NULL, (xmlChar *) "parent",
3193 (xmlChar *) GST_OBJECT_NAME (GST_PAD_PARENT (pad)));
3195 /* FIXME FIXME FIXME! */
3200 #endif /* GST_DISABLE_LOADSAVE */
3203 * should be called with pad OBJECT_LOCK and STREAM_LOCK held.
3204 * GST_PAD_IS_BLOCKED (pad) == TRUE when this function is
3207 * This function perform the pad blocking when an event, buffer push
3208 * or buffer_alloc is performed on a _SRC_ pad. It blocks the
3209 * streaming thread after informing the pad has been blocked.
3211 * An application can with this method wait and block any streaming
3212 * thread and perform operations such as seeking or linking.
3214 * Two methods are available for notifying the application of the
3216 * - the callback method, which happens in the STREAMING thread with
3217 * the STREAM_LOCK held. With this method, the most usefull way of
3218 * dealing with the callback is to post a message to the main thread
3219 * where the pad block can then be handled outside of the streaming
3220 * thread. With the last method one can perform all operations such
3221 * as doing a state change, linking, unblocking, seeking etc on the
3223 * - the GCond signal method, which makes any thread unblock when
3224 * the pad block happens.
3226 * During the actual blocking state, the GST_PAD_BLOCKING flag is set.
3227 * The GST_PAD_BLOCKING flag is unset when the pad was unblocked.
3231 static GstFlowReturn
3232 handle_pad_block (GstPad * pad)
3234 GstPadBlockCallback callback;
3236 GstFlowReturn ret = GST_FLOW_OK;
3238 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "signal block taken");
3240 /* flushing, don't bother trying to block and return WRONG_STATE
3242 if (GST_PAD_IS_FLUSHING (pad))
3243 goto flushingnonref;
3245 /* we grab an extra ref for the callbacks, this is probably not
3246 * needed (callback code does not have a ref and cannot unref). I
3247 * think this was done to make it possible to unref the element in
3248 * the callback, which is in the end totally impossible as it
3249 * requires grabbing the STREAM_LOCK and OBJECT_LOCK which are
3250 * all taken when calling this function. */
3251 gst_object_ref (pad);
3253 /* we either have a callback installed to notify the block or
3254 * some other thread is doing a GCond wait. */
3255 callback = pad->block_callback;
3257 /* there is a callback installed, call it. We release the
3258 * lock so that the callback can do something usefull with the
3260 user_data = pad->block_data;
3261 GST_OBJECT_UNLOCK (pad);
3262 callback (pad, TRUE, user_data);
3263 GST_OBJECT_LOCK (pad);
3265 /* we released the lock, recheck flushing */
3266 if (GST_PAD_IS_FLUSHING (pad))
3269 /* no callback, signal the thread that is doing a GCond wait
3271 GST_PAD_BLOCK_BROADCAST (pad);
3274 /* OBJECT_LOCK could have been released when we did the callback, which
3275 * then could have made the pad unblock so we need to check the blocking
3276 * condition again. */
3277 while (GST_PAD_IS_BLOCKED (pad)) {
3278 /* now we block the streaming thread. It can be unlocked when we
3279 * deactivate the pad (which will also set the FLUSHING flag) or
3280 * when the pad is unblocked. A flushing event will also unblock
3281 * the pad after setting the FLUSHING flag. */
3282 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3283 "Waiting to be unblocked or set flushing");
3284 GST_OBJECT_FLAG_SET (pad, GST_PAD_BLOCKING);
3285 GST_PAD_BLOCK_WAIT (pad);
3286 GST_OBJECT_FLAG_UNSET (pad, GST_PAD_BLOCKING);
3288 /* see if we got unblocked by a flush or not */
3289 if (GST_PAD_IS_FLUSHING (pad))
3293 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "got unblocked");
3295 /* when we get here, the pad is unblocked again and we perform
3296 * the needed unblock code. */
3297 callback = pad->block_callback;
3299 /* we need to call the callback */
3300 user_data = pad->block_data;
3301 GST_OBJECT_UNLOCK (pad);
3302 callback (pad, FALSE, user_data);
3303 GST_OBJECT_LOCK (pad);
3305 /* we need to signal the thread waiting on the GCond */
3306 GST_PAD_BLOCK_BROADCAST (pad);
3309 gst_object_unref (pad);
3315 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "pad was flushing");
3316 return GST_FLOW_WRONG_STATE;
3320 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "pad became flushing");
3321 gst_object_unref (pad);
3322 return GST_FLOW_WRONG_STATE;
3326 /**********************************************************************
3327 * Data passing functions
3331 gst_pad_emit_have_data_signal (GstPad * pad, GstMiniObject * obj)
3334 GValue args[2] = { {0}, {0} };
3339 g_value_init (&ret, G_TYPE_BOOLEAN);
3340 g_value_set_boolean (&ret, TRUE);
3341 g_value_init (&args[0], GST_TYPE_PAD);
3342 g_value_set_object (&args[0], pad);
3343 g_value_init (&args[1], GST_TYPE_MINI_OBJECT); // G_TYPE_POINTER);
3344 gst_value_set_mini_object (&args[1], obj);
3346 if (GST_IS_EVENT (obj))
3347 detail = event_quark;
3349 detail = buffer_quark;
3352 g_signal_emitv (args, gst_pad_signals[PAD_HAVE_DATA], detail, &ret);
3353 res = g_value_get_boolean (&ret);
3356 g_value_unset (&ret);
3357 g_value_unset (&args[0]);
3358 g_value_unset (&args[1]);
3363 /* this is the chain function that does not perform the additional argument
3364 * checking for that little extra speed.
3366 static inline GstFlowReturn
3367 gst_pad_chain_unchecked (GstPad * pad, GstBuffer * buffer)
3370 gboolean caps_changed;
3371 GstPadChainFunction chainfunc;
3373 gboolean emit_signal;
3375 GST_PAD_STREAM_LOCK (pad);
3377 GST_OBJECT_LOCK (pad);
3378 if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad)))
3381 caps = GST_BUFFER_CAPS (buffer);
3382 caps_changed = caps && caps != GST_PAD_CAPS (pad);
3384 emit_signal = GST_PAD_DO_BUFFER_SIGNALS (pad) > 0;
3385 GST_OBJECT_UNLOCK (pad);
3387 /* see if the signal should be emited, we emit before caps nego as
3388 * we might drop the buffer and do capsnego for nothing. */
3389 if (G_UNLIKELY (emit_signal)) {
3390 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (buffer)))
3394 /* we got a new datatype on the pad, see if it can handle it */
3395 if (G_UNLIKELY (caps_changed)) {
3396 GST_DEBUG_OBJECT (pad, "caps changed to %p %" GST_PTR_FORMAT, caps, caps);
3397 if (G_UNLIKELY (!gst_pad_configure_sink (pad, caps)))
3398 goto not_negotiated;
3401 /* NOTE: we read the chainfunc unlocked.
3402 * we cannot hold the lock for the pad so we might send
3403 * the data to the wrong function. This is not really a
3404 * problem since functions are assigned at creation time
3405 * and don't change that often... */
3406 if (G_UNLIKELY ((chainfunc = GST_PAD_CHAINFUNC (pad)) == NULL))
3409 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3410 "calling chainfunction &%s", GST_DEBUG_FUNCPTR_NAME (chainfunc));
3412 ret = chainfunc (pad, buffer);
3414 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3415 "called chainfunction &%s, returned %s",
3416 GST_DEBUG_FUNCPTR_NAME (chainfunc), gst_flow_get_name (ret));
3418 GST_PAD_STREAM_UNLOCK (pad);
3425 gst_buffer_unref (buffer);
3426 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3427 "pushing, but pad was flushing");
3428 GST_OBJECT_UNLOCK (pad);
3429 GST_PAD_STREAM_UNLOCK (pad);
3430 return GST_FLOW_WRONG_STATE;
3434 gst_buffer_unref (buffer);
3435 GST_DEBUG_OBJECT (pad, "Dropping buffer due to FALSE probe return");
3436 GST_PAD_STREAM_UNLOCK (pad);
3441 gst_buffer_unref (buffer);
3442 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3443 "pushing buffer but pad did not accept");
3444 GST_PAD_STREAM_UNLOCK (pad);
3445 return GST_FLOW_NOT_NEGOTIATED;
3449 gst_buffer_unref (buffer);
3450 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3451 "pushing, but not chainhandler");
3452 GST_ELEMENT_ERROR (GST_PAD_PARENT (pad), CORE, PAD, (NULL),
3453 ("push on pad %s:%s but it has no chainfunction",
3454 GST_DEBUG_PAD_NAME (pad)));
3455 GST_PAD_STREAM_UNLOCK (pad);
3456 return GST_FLOW_NOT_SUPPORTED;
3462 * @pad: a sink #GstPad, returns GST_FLOW_ERROR if not.
3463 * @buffer: the #GstBuffer to send, return GST_FLOW_ERROR if not.
3465 * Chain a buffer to @pad.
3467 * The function returns #GST_FLOW_WRONG_STATE if the pad was flushing.
3469 * If the caps on @buffer are different from the current caps on @pad, this
3470 * function will call any setcaps function (see gst_pad_set_setcaps_function())
3471 * installed on @pad. If the new caps are not acceptable for @pad, this function
3472 * returns #GST_FLOW_NOT_NEGOTIATED.
3474 * The function proceeds calling the chain function installed on @pad (see
3475 * gst_pad_set_chain_function()) and the return value of that function is
3476 * returned to the caller. #GST_FLOW_NOT_SUPPORTED is returned if @pad has no
3479 * In all cases, success or failure, the caller loses its reference to @buffer
3480 * after calling this function.
3482 * Returns: a #GstFlowReturn from the pad.
3487 gst_pad_chain (GstPad * pad, GstBuffer * buffer)
3489 g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
3490 g_return_val_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SINK,
3492 g_return_val_if_fail (GST_IS_BUFFER (buffer), GST_FLOW_ERROR);
3494 return gst_pad_chain_unchecked (pad, buffer);
3499 * @pad: a source #GstPad, returns #GST_FLOW_ERROR if not.
3500 * @buffer: the #GstBuffer to push returns GST_FLOW_ERROR if not.
3502 * Pushes a buffer to the peer of @pad.
3504 * This function will call an installed pad block before triggering any
3505 * installed pad probes.
3507 * If the caps on @buffer are different from the currently configured caps on
3508 * @pad, this function will call any installed setcaps function on @pad (see
3509 * gst_pad_set_setcaps_function()). In case of failure to renegotiate the new
3510 * format, this function returns #GST_FLOW_NOT_NEGOTIATED.
3512 * The function proceeds calling gst_pad_chain() on the peer pad and returns the
3513 * value from that function. If @pad has no peer, #GST_FLOW_NOT_LINKED will be
3516 * In all cases, success or failure, the caller loses its reference to @buffer
3517 * after calling this function.
3519 * Returns: a #GstFlowReturn from the peer pad.
3524 gst_pad_push (GstPad * pad, GstBuffer * buffer)
3530 gboolean caps_changed;
3532 g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
3533 g_return_val_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SRC, GST_FLOW_ERROR);
3534 g_return_val_if_fail (GST_IS_BUFFER (buffer), GST_FLOW_ERROR);
3536 GST_OBJECT_LOCK (pad);
3538 /* FIXME: this check can go away; pad_set_blocked could be implemented with
3539 * probes completely or probes with an extended pad block. */
3540 while (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad)))
3541 if ((ret = handle_pad_block (pad)) != GST_FLOW_OK)
3544 /* we emit signals on the pad arg, the peer will have a chance to
3545 * emit in the _chain() function */
3546 if (G_UNLIKELY (GST_PAD_DO_BUFFER_SIGNALS (pad) > 0)) {
3547 /* unlock before emitting */
3548 GST_OBJECT_UNLOCK (pad);
3550 /* if the signal handler returned FALSE, it means we should just drop the
3552 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (buffer)))
3555 GST_OBJECT_LOCK (pad);
3558 if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
3561 /* take ref to peer pad before releasing the lock */
3562 gst_object_ref (peer);
3564 /* Before pushing the buffer to the peer pad, ensure that caps
3565 * are set on this pad */
3566 caps = GST_BUFFER_CAPS (buffer);
3567 caps_changed = caps && caps != GST_PAD_CAPS (pad);
3569 GST_OBJECT_UNLOCK (pad);
3571 /* we got a new datatype from the pad, it had better handle it */
3572 if (G_UNLIKELY (caps_changed)) {
3573 GST_DEBUG_OBJECT (pad, "caps changed to %p %" GST_PTR_FORMAT, caps, caps);
3574 if (G_UNLIKELY (!gst_pad_configure_src (pad, caps, TRUE)))
3575 goto not_negotiated;
3578 ret = gst_pad_chain_unchecked (peer, buffer);
3580 gst_object_unref (peer);
3584 /* ERROR recovery here */
3587 gst_buffer_unref (buffer);
3588 GST_DEBUG_OBJECT (pad, "pad block stopped by flush");
3589 GST_OBJECT_UNLOCK (pad);
3594 gst_buffer_unref (buffer);
3595 GST_DEBUG_OBJECT (pad, "Dropping buffer due to FALSE probe return");
3600 gst_buffer_unref (buffer);
3601 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3602 "pushing, but it was not linked");
3603 GST_OBJECT_UNLOCK (pad);
3604 return GST_FLOW_NOT_LINKED;
3608 gst_buffer_unref (buffer);
3609 gst_object_unref (peer);
3610 GST_CAT_DEBUG_OBJECT (GST_CAT_SCHEDULING, pad,
3611 "element pushed buffer then refused to accept the caps");
3612 return GST_FLOW_NOT_NEGOTIATED;
3617 * gst_pad_check_pull_range:
3618 * @pad: a sink #GstPad.
3620 * Checks if a gst_pad_pull_range() can be performed on the peer
3621 * source pad. This function is used by plugins that want to check
3622 * if they can use random access on the peer source pad.
3624 * The peer sourcepad can implement a custom #GstPadCheckGetRangeFunction
3625 * if it needs to perform some logic to determine if pull_range is
3628 * Returns: a gboolean with the result.
3633 gst_pad_check_pull_range (GstPad * pad)
3637 GstPadCheckGetRangeFunction checkgetrangefunc;
3639 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
3641 GST_OBJECT_LOCK (pad);
3642 if (GST_PAD_DIRECTION (pad) != GST_PAD_SINK)
3643 goto wrong_direction;
3645 if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
3648 gst_object_ref (peer);
3649 GST_OBJECT_UNLOCK (pad);
3651 /* see note in above function */
3652 if (G_LIKELY ((checkgetrangefunc = peer->checkgetrangefunc) == NULL)) {
3653 /* FIXME, kindoff ghetto */
3654 ret = GST_PAD_GETRANGEFUNC (peer) != NULL;
3656 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3657 "calling checkgetrangefunc %s of peer pad %s:%s",
3658 GST_DEBUG_FUNCPTR_NAME (checkgetrangefunc), GST_DEBUG_PAD_NAME (peer));
3660 ret = checkgetrangefunc (peer);
3663 gst_object_unref (peer);
3667 /* ERROR recovery here */
3670 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3671 "checking pull range, but pad must be a sinkpad");
3672 GST_OBJECT_UNLOCK (pad);
3677 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3678 "checking pull range, but it was not linked");
3679 GST_OBJECT_UNLOCK (pad);
3685 * gst_pad_get_range:
3686 * @pad: a src #GstPad, returns #GST_FLOW_ERROR if not.
3687 * @offset: The start offset of the buffer
3688 * @size: The length of the buffer
3689 * @buffer: a pointer to hold the #GstBuffer, returns #GST_FLOW_ERROR if %NULL.
3691 * When @pad is flushing this function returns #GST_FLOW_WRONG_STATE
3694 * Calls the getrange function of @pad, see #GstPadGetRangeFunction for a
3695 * description of a getrange function. If @pad has no getrange function
3696 * installed (see gst_pad_set_getrange_function()) this function returns
3697 * #GST_FLOW_NOT_SUPPORTED.
3699 * Returns: a #GstFlowReturn from the pad.
3704 gst_pad_get_range (GstPad * pad, guint64 offset, guint size,
3705 GstBuffer ** buffer)
3708 GstPadGetRangeFunction getrangefunc;
3709 gboolean emit_signal;
3711 g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
3712 g_return_val_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SRC, GST_FLOW_ERROR);
3713 g_return_val_if_fail (buffer != NULL, GST_FLOW_ERROR);
3715 GST_PAD_STREAM_LOCK (pad);
3717 GST_OBJECT_LOCK (pad);
3718 if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad)))
3721 emit_signal = GST_PAD_DO_BUFFER_SIGNALS (pad) > 0;
3722 GST_OBJECT_UNLOCK (pad);
3724 if (G_UNLIKELY ((getrangefunc = GST_PAD_GETRANGEFUNC (pad)) == NULL))
3727 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3728 "calling getrangefunc %s, offset %"
3729 G_GUINT64_FORMAT ", size %u",
3730 GST_DEBUG_FUNCPTR_NAME (getrangefunc), offset, size);
3732 ret = getrangefunc (pad, offset, size, buffer);
3734 /* can only fire the signal if we have a valid buffer */
3735 if (G_UNLIKELY (emit_signal) && (ret == GST_FLOW_OK)) {
3736 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (*buffer)))
3740 GST_PAD_STREAM_UNLOCK (pad);
3747 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3748 "pulling range, but pad was flushing");
3749 GST_OBJECT_UNLOCK (pad);
3750 GST_PAD_STREAM_UNLOCK (pad);
3751 return GST_FLOW_WRONG_STATE;
3755 GST_ELEMENT_ERROR (GST_PAD_PARENT (pad), CORE, PAD, (NULL),
3756 ("pullrange on pad %s:%s but it has no getrangefunction",
3757 GST_DEBUG_PAD_NAME (pad)));
3758 GST_PAD_STREAM_UNLOCK (pad);
3759 return GST_FLOW_NOT_SUPPORTED;
3763 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3764 "Dropping data after FALSE probe return");
3765 GST_PAD_STREAM_UNLOCK (pad);
3766 gst_buffer_unref (*buffer);
3768 return GST_FLOW_UNEXPECTED;
3774 * gst_pad_pull_range:
3775 * @pad: a sink #GstPad, returns GST_FLOW_ERROR if not.
3776 * @offset: The start offset of the buffer
3777 * @size: The length of the buffer
3778 * @buffer: a pointer to hold the #GstBuffer, returns GST_FLOW_ERROR if %NULL.
3780 * Pulls a buffer from the peer pad.
3782 * This function will first trigger the pad block signal if it was
3785 * When @pad is not linked #GST_FLOW_NOT_LINKED is returned else this
3786 * function returns the result of gst_pad_get_range() on the peer pad.
3787 * See gst_pad_get_range() for a list of return values and for the
3788 * semantics of the arguments of this function.
3790 * Returns: a #GstFlowReturn from the peer pad.
3791 * When this function returns #GST_FLOW_OK, @buffer will contain a valid
3792 * #GstBuffer that should be freed with gst_buffer_unref() after usage.
3793 * @buffer may not be used or freed when any other return value than
3794 * #GST_FLOW_OK is returned.
3799 gst_pad_pull_range (GstPad * pad, guint64 offset, guint size,
3800 GstBuffer ** buffer)
3804 gboolean emit_signal;
3806 g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
3807 g_return_val_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SINK,
3809 g_return_val_if_fail (buffer != NULL, GST_FLOW_ERROR);
3811 GST_OBJECT_LOCK (pad);
3813 while (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad)))
3814 handle_pad_block (pad);
3816 if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
3819 /* signal emision for the pad, peer has chance to emit when
3820 * we call _get_range() */
3821 emit_signal = GST_PAD_DO_BUFFER_SIGNALS (pad) > 0;
3823 gst_object_ref (peer);
3824 GST_OBJECT_UNLOCK (pad);
3826 ret = gst_pad_get_range (peer, offset, size, buffer);
3828 gst_object_unref (peer);
3830 /* can only fire the signal if we have a valid buffer */
3831 if (G_UNLIKELY (emit_signal) && (ret == GST_FLOW_OK)) {
3832 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (*buffer)))
3837 /* ERROR recovery here */
3840 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3841 "pulling range, but it was not linked");
3842 GST_OBJECT_UNLOCK (pad);
3843 return GST_FLOW_NOT_LINKED;
3847 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3848 "Dropping data after FALSE probe return");
3849 gst_buffer_unref (*buffer);
3851 return GST_FLOW_UNEXPECTED;
3856 * gst_pad_push_event:
3857 * @pad: a #GstPad to push the event to.
3858 * @event: the #GstEvent to send to the pad.
3860 * Sends the event to the peer of the given pad. This function is
3861 * mainly used by elements to send events to their peer
3864 * This function takes owership of the provided event so you should
3865 * gst_event_ref() it if you want to reuse the event after this call.
3867 * Returns: TRUE if the event was handled.
3872 gst_pad_push_event (GstPad * pad, GstEvent * event)
3877 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
3878 g_return_val_if_fail (event != NULL, FALSE);
3879 g_return_val_if_fail (GST_IS_EVENT (event), FALSE);
3881 GST_LOG_OBJECT (pad, "event:%s", GST_EVENT_TYPE_NAME (event));
3883 GST_OBJECT_LOCK (pad);
3885 /* Two checks to be made:
3886 * . (un)set the FLUSHING flag for flushing events,
3887 * . handle pad blocking */
3888 switch (GST_EVENT_TYPE (event)) {
3889 case GST_EVENT_FLUSH_START:
3890 GST_PAD_SET_FLUSHING (pad);
3892 if (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad))) {
3893 /* flush start will have set the FLUSHING flag and will then
3894 * unlock all threads doing a GCond wait on the blocking pad. This
3895 * will typically unblock the STREAMING thread blocked on a pad. */
3896 GST_LOG_OBJECT (pad, "Pad is blocked, not forwarding flush-start, "
3897 "doing block signal.");
3898 GST_PAD_BLOCK_BROADCAST (pad);
3902 case GST_EVENT_FLUSH_STOP:
3903 GST_PAD_UNSET_FLUSHING (pad);
3905 /* if we are blocked, flush away the FLUSH_STOP event */
3906 if (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad))) {
3907 GST_LOG_OBJECT (pad, "Pad is blocked, not forwarding flush-stop");
3912 while (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad))) {
3913 /* block the event as long as the pad is blocked */
3914 if (handle_pad_block (pad) != GST_FLOW_OK)
3920 if (G_UNLIKELY (GST_PAD_DO_EVENT_SIGNALS (pad) > 0)) {
3921 GST_OBJECT_UNLOCK (pad);
3923 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (event)))
3926 GST_OBJECT_LOCK (pad);
3928 peerpad = GST_PAD_PEER (pad);
3929 if (peerpad == NULL)
3932 GST_LOG_OBJECT (pad, "sending event %s to peerpad %" GST_PTR_FORMAT,
3933 GST_EVENT_TYPE_NAME (event), peerpad);
3934 gst_object_ref (peerpad);
3935 GST_OBJECT_UNLOCK (pad);
3937 result = gst_pad_send_event (peerpad, event);
3939 GST_LOG_OBJECT (pad, "sent event %s to peerpad %" GST_PTR_FORMAT,
3940 GST_EVENT_TYPE_NAME (event), peerpad);
3941 gst_object_unref (peerpad);
3945 /* ERROR handling */
3948 GST_DEBUG_OBJECT (pad, "Dropping event after FALSE probe return");
3949 gst_event_unref (event);
3954 GST_DEBUG_OBJECT (pad, "Dropping event because pad is not linked");
3955 gst_event_unref (event);
3956 GST_OBJECT_UNLOCK (pad);
3961 GST_DEBUG_OBJECT (pad,
3962 "Not forwarding event since we're flushing and blocking");
3963 gst_event_unref (event);
3964 GST_OBJECT_UNLOCK (pad);
3970 * gst_pad_send_event:
3971 * @pad: a #GstPad to send the event to.
3972 * @event: the #GstEvent to send to the pad.
3974 * Sends the event to the pad. This function can be used
3975 * by applications to send events in the pipeline.
3977 * If @pad is a source pad, @event should be an upstream event. If @pad is a
3978 * sink pad, @event should be a downstream event. For example, you would not
3979 * send a #GST_EVENT_EOS on a src pad; EOS events only propagate downstream.
3980 * Furthermore, some downstream events have to be serialized with data flow,
3981 * like EOS, while some can travel out-of-band, like #GST_EVENT_FLUSH_START. If
3982 * the event needs to be serialized with data flow, this function will take the
3983 * pad's stream lock while calling its event function.
3985 * To find out whether an event type is upstream, downstream, or downstream and
3986 * serialized, see #GstEventTypeFlags, gst_event_type_get_flags(),
3987 * #GST_EVENT_IS_UPSTREAM, #GST_EVENT_IS_DOWNSTREAM, and
3988 * #GST_EVENT_IS_SERIALIZED. Note that in practice that an application or plugin
3989 * doesn't need to bother itself with this information; the core handles all
3990 * necessary locks and checks.
3992 * This function takes owership of the provided event so you should
3993 * gst_event_ref() it if you want to reuse the event after this call.
3995 * Returns: TRUE if the event was handled.
3998 gst_pad_send_event (GstPad * pad, GstEvent * event)
4000 gboolean result = FALSE;
4001 GstPadEventFunction eventfunc;
4002 gboolean serialized, need_unlock = FALSE;
4004 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
4005 g_return_val_if_fail (event != NULL, FALSE);
4007 GST_OBJECT_LOCK (pad);
4008 if (GST_PAD_IS_SINK (pad)) {
4009 if (G_UNLIKELY (!GST_EVENT_IS_DOWNSTREAM (event)))
4010 goto wrong_direction;
4011 serialized = GST_EVENT_IS_SERIALIZED (event);
4012 } else if (GST_PAD_IS_SRC (pad)) {
4013 if (G_UNLIKELY (!GST_EVENT_IS_UPSTREAM (event)))
4014 goto wrong_direction;
4015 /* events on srcpad never are serialized */
4018 goto unknown_direction;
4020 if (G_UNLIKELY (GST_EVENT_SRC (event) == NULL)) {
4021 GST_LOG_OBJECT (pad, "event had no source, setting pad as event source");
4022 GST_EVENT_SRC (event) = gst_object_ref (pad);
4026 if (G_UNLIKELY (GST_PAD_DO_EVENT_SIGNALS (pad) > 0)) {
4027 GST_OBJECT_UNLOCK (pad);
4029 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT_CAST (event)))
4032 GST_OBJECT_LOCK (pad);
4035 switch (GST_EVENT_TYPE (event)) {
4036 case GST_EVENT_FLUSH_START:
4037 GST_CAT_DEBUG_OBJECT (GST_CAT_EVENT, pad,
4038 "have event type %d (FLUSH_START)", GST_EVENT_TYPE (event));
4040 /* can't even accept a flush begin event when flushing */
4041 if (GST_PAD_IS_FLUSHING (pad))
4043 GST_PAD_SET_FLUSHING (pad);
4044 GST_CAT_DEBUG_OBJECT (GST_CAT_EVENT, pad, "set flush flag");
4046 case GST_EVENT_FLUSH_STOP:
4047 GST_PAD_UNSET_FLUSHING (pad);
4048 GST_CAT_DEBUG_OBJECT (GST_CAT_EVENT, pad, "cleared flush flag");
4049 GST_OBJECT_UNLOCK (pad);
4050 /* grab stream lock */
4051 GST_PAD_STREAM_LOCK (pad);
4053 GST_OBJECT_LOCK (pad);
4056 GST_CAT_DEBUG_OBJECT (GST_CAT_EVENT, pad, "have event type %s",
4057 GST_EVENT_TYPE_NAME (event));
4059 /* make this a little faster, no point in grabbing the lock
4060 * if the pad is allready flushing. */
4061 if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad)))
4065 /* lock order: STREAM_LOCK, LOCK, recheck flushing. */
4066 GST_OBJECT_UNLOCK (pad);
4067 GST_PAD_STREAM_LOCK (pad);
4069 GST_OBJECT_LOCK (pad);
4070 if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad)))
4075 if (G_UNLIKELY ((eventfunc = GST_PAD_EVENTFUNC (pad)) == NULL))
4078 GST_OBJECT_UNLOCK (pad);
4080 result = eventfunc (pad, event);
4083 GST_PAD_STREAM_UNLOCK (pad);
4087 /* ERROR handling */
4090 g_warning ("pad %s:%s sending %s event in wrong direction",
4091 GST_DEBUG_PAD_NAME (pad), GST_EVENT_TYPE_NAME (event));
4092 GST_OBJECT_UNLOCK (pad);
4093 gst_event_unref (event);
4098 g_warning ("pad %s:%s has invalid direction", GST_DEBUG_PAD_NAME (pad));
4099 GST_OBJECT_UNLOCK (pad);
4100 gst_event_unref (event);
4105 g_warning ("pad %s:%s has no event handler, file a bug.",
4106 GST_DEBUG_PAD_NAME (pad));
4107 GST_OBJECT_UNLOCK (pad);
4108 gst_event_unref (event);
4113 GST_OBJECT_UNLOCK (pad);
4115 GST_PAD_STREAM_UNLOCK (pad);
4116 GST_CAT_INFO_OBJECT (GST_CAT_EVENT, pad,
4117 "Received event on flushing pad. Discarding");
4118 gst_event_unref (event);
4123 GST_DEBUG_OBJECT (pad, "Dropping event after FALSE probe return");
4124 gst_event_unref (event);
4130 * gst_pad_set_element_private:
4131 * @pad: the #GstPad to set the private data of.
4132 * @priv: The private data to attach to the pad.
4134 * Set the given private data gpointer on the pad.
4135 * This function can only be used by the element that owns the pad.
4136 * No locking is performed in this function.
4139 gst_pad_set_element_private (GstPad * pad, gpointer priv)
4141 pad->element_private = priv;
4145 * gst_pad_get_element_private:
4146 * @pad: the #GstPad to get the private data of.
4148 * Gets the private data of a pad.
4149 * No locking is performed in this function.
4151 * Returns: a #gpointer to the private data.
4154 gst_pad_get_element_private (GstPad * pad)
4156 return pad->element_private;
4160 * gst_pad_start_task:
4161 * @pad: the #GstPad to start the task of
4162 * @func: the task function to call
4163 * @data: data passed to the task function
4165 * Starts a task that repeadedly calls @func with @data. This function
4166 * is nostly used in the pad activation function to start the
4167 * dataflow. This function will automatically acquire the #GST_PAD_STREAM_LOCK
4168 * of the pad before calling @func.
4170 * Returns: a %TRUE if the task could be started.
4173 gst_pad_start_task (GstPad * pad, GstTaskFunction func, gpointer data)
4177 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
4178 g_return_val_if_fail (func != NULL, FALSE);
4180 GST_DEBUG_OBJECT (pad, "start task");
4182 GST_OBJECT_LOCK (pad);
4183 task = GST_PAD_TASK (pad);
4185 task = gst_task_create (func, data);
4186 gst_task_set_lock (task, GST_PAD_GET_STREAM_LOCK (pad));
4187 GST_PAD_TASK (pad) = task;
4188 GST_DEBUG_OBJECT (pad, "created task");
4190 gst_task_start (task);
4191 GST_OBJECT_UNLOCK (pad);
4197 * gst_pad_pause_task:
4198 * @pad: the #GstPad to pause the task of
4200 * Pause the task of @pad. This function will also make sure that the
4201 * function executed by the task will effectively stop.
4203 * Returns: a TRUE if the task could be paused or FALSE when the pad
4207 gst_pad_pause_task (GstPad * pad)
4211 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
4213 GST_DEBUG_OBJECT (pad, "pause task");
4215 GST_OBJECT_LOCK (pad);
4216 task = GST_PAD_TASK (pad);
4219 gst_task_pause (task);
4220 GST_OBJECT_UNLOCK (pad);
4222 GST_PAD_STREAM_LOCK (pad);
4223 GST_PAD_STREAM_UNLOCK (pad);
4229 GST_DEBUG_OBJECT (pad, "pad has no task");
4230 GST_OBJECT_UNLOCK (pad);
4236 * gst_pad_stop_task:
4237 * @pad: the #GstPad to stop the task of
4239 * Stop the task of @pad. This function will also make sure that the
4240 * function executed by the task will effectively stop if not called
4241 * from the GstTaskFunction.
4243 * This function will deadlock if called from the GstTaskFunction of
4244 * the task. Use gst_task_pause() instead.
4246 * Regardless of whether the pad has a task, the stream lock is acquired and
4247 * released so as to ensure that streaming through this pad has finished.
4249 * Returns: a TRUE if the task could be stopped or FALSE on error.
4252 gst_pad_stop_task (GstPad * pad)
4256 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
4258 GST_DEBUG_OBJECT (pad, "stop task");
4260 GST_OBJECT_LOCK (pad);
4261 task = GST_PAD_TASK (pad);
4264 GST_PAD_TASK (pad) = NULL;
4265 gst_task_stop (task);
4266 GST_OBJECT_UNLOCK (pad);
4268 GST_PAD_STREAM_LOCK (pad);
4269 GST_PAD_STREAM_UNLOCK (pad);
4271 if (!gst_task_join (task))
4274 gst_object_unref (task);
4280 GST_DEBUG_OBJECT (pad, "no task");
4281 GST_OBJECT_UNLOCK (pad);
4283 GST_PAD_STREAM_LOCK (pad);
4284 GST_PAD_STREAM_UNLOCK (pad);
4286 /* this is not an error */
4291 /* this is bad, possibly the application tried to join the task from
4292 * the task's thread. We install the task again so that it will be stopped
4293 * again from the right thread next time hopefully. */
4294 GST_OBJECT_LOCK (pad);
4295 GST_DEBUG_OBJECT (pad, "join failed");
4296 /* we can only install this task if there was no other task */
4297 if (GST_PAD_TASK (pad) == NULL)
4298 GST_PAD_TASK (pad) = task;
4299 GST_OBJECT_UNLOCK (pad);