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 | G_PARAM_STATIC_STRINGS));
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 | G_PARAM_STATIC_STRINGS));
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,
320 G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
322 #ifndef GST_DISABLE_LOADSAVE
323 gstobject_class->save_thyself = GST_DEBUG_FUNCPTR (gst_pad_save_thyself);
325 gstobject_class->path_string_separator = ".";
327 klass->have_data = default_have_data;
331 gst_pad_init (GstPad * pad)
333 GST_PAD_DIRECTION (pad) = GST_PAD_UNKNOWN;
334 GST_PAD_PEER (pad) = NULL;
336 GST_PAD_CHAINFUNC (pad) = NULL;
338 GST_PAD_LINKFUNC (pad) = NULL;
340 GST_PAD_CAPS (pad) = NULL;
341 GST_PAD_GETCAPSFUNC (pad) = NULL;
343 GST_PAD_ACTIVATEFUNC (pad) = GST_DEBUG_FUNCPTR (gst_pad_activate_default);
344 GST_PAD_EVENTFUNC (pad) = GST_DEBUG_FUNCPTR (gst_pad_event_default);
345 GST_PAD_QUERYTYPEFUNC (pad) =
346 GST_DEBUG_FUNCPTR (gst_pad_get_query_types_default);
347 GST_PAD_QUERYFUNC (pad) = GST_DEBUG_FUNCPTR (gst_pad_query_default);
348 GST_PAD_INTLINKFUNC (pad) =
349 GST_DEBUG_FUNCPTR (gst_pad_get_internal_links_default);
350 GST_PAD_ACCEPTCAPSFUNC (pad) = GST_DEBUG_FUNCPTR (gst_pad_acceptcaps_default);
352 pad->do_buffer_signals = 0;
353 pad->do_event_signals = 0;
355 GST_PAD_SET_FLUSHING (pad);
357 pad->preroll_lock = g_mutex_new ();
358 pad->preroll_cond = g_cond_new ();
360 pad->stream_rec_lock = g_new (GStaticRecMutex, 1);
361 g_static_rec_mutex_init (pad->stream_rec_lock);
363 pad->block_cond = g_cond_new ();
367 gst_pad_dispose (GObject * object)
369 GstPad *pad = GST_PAD (object);
372 GST_CAT_DEBUG_OBJECT (GST_CAT_REFCOUNTING, pad, "dispose");
374 /* unlink the peer pad */
375 if ((peer = gst_pad_get_peer (pad))) {
376 /* window for MT unsafeness, someone else could unlink here
377 * and then we call unlink with wrong pads. The unlink
378 * function would catch this and safely return failed. */
379 if (GST_PAD_IS_SRC (pad))
380 gst_pad_unlink (pad, peer);
382 gst_pad_unlink (peer, pad);
384 gst_object_unref (peer);
388 gst_caps_replace (&GST_PAD_CAPS (pad), NULL);
390 gst_pad_set_pad_template (pad, NULL);
392 G_OBJECT_CLASS (parent_class)->dispose (object);
396 gst_pad_finalize (GObject * object)
398 GstPad *pad = GST_PAD (object);
401 /* in case the task is still around, clean it up */
402 if ((task = GST_PAD_TASK (pad))) {
403 gst_task_join (task);
404 GST_PAD_TASK (pad) = NULL;
405 gst_object_unref (task);
408 if (pad->stream_rec_lock) {
409 g_static_rec_mutex_free (pad->stream_rec_lock);
410 g_free (pad->stream_rec_lock);
411 pad->stream_rec_lock = NULL;
413 if (pad->preroll_lock) {
414 g_mutex_free (pad->preroll_lock);
415 g_cond_free (pad->preroll_cond);
416 pad->preroll_lock = NULL;
417 pad->preroll_cond = NULL;
419 if (pad->block_cond) {
420 g_cond_free (pad->block_cond);
421 pad->block_cond = NULL;
424 G_OBJECT_CLASS (parent_class)->finalize (object);
428 gst_pad_set_property (GObject * object, guint prop_id,
429 const GValue * value, GParamSpec * pspec)
431 g_return_if_fail (GST_IS_PAD (object));
434 case PAD_PROP_DIRECTION:
435 GST_PAD_DIRECTION (object) = g_value_get_enum (value);
437 case PAD_PROP_TEMPLATE:
438 gst_pad_set_pad_template (GST_PAD_CAST (object),
439 (GstPadTemplate *) g_value_get_object (value));
442 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
448 gst_pad_get_property (GObject * object, guint prop_id,
449 GValue * value, GParamSpec * pspec)
451 g_return_if_fail (GST_IS_PAD (object));
455 GST_OBJECT_LOCK (object);
456 g_value_set_boxed (value, GST_PAD_CAPS (object));
457 GST_OBJECT_UNLOCK (object);
459 case PAD_PROP_DIRECTION:
460 g_value_set_enum (value, GST_PAD_DIRECTION (object));
462 case PAD_PROP_TEMPLATE:
463 g_value_set_object (value, GST_PAD_PAD_TEMPLATE (object));
466 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
473 * @name: the name of the new pad.
474 * @direction: the #GstPadDirection of the pad.
476 * Creates a new pad with the given name in the given direction.
477 * If name is NULL, a guaranteed unique name (across all pads)
479 * This function makes a copy of the name so you can safely free the name.
481 * Returns: a new #GstPad, or NULL in case of an error.
486 gst_pad_new (const gchar * name, GstPadDirection direction)
488 return g_object_new (GST_TYPE_PAD,
489 "name", name, "direction", direction, NULL);
493 * gst_pad_new_from_template:
494 * @templ: the pad template to use
495 * @name: the name of the element
497 * Creates a new pad with the given name from the given template.
498 * If name is NULL, a guaranteed unique name (across all pads)
500 * This function makes a copy of the name so you can safely free the name.
502 * Returns: a new #GstPad, or NULL in case of an error.
505 gst_pad_new_from_template (GstPadTemplate * templ, const gchar * name)
507 g_return_val_if_fail (GST_IS_PAD_TEMPLATE (templ), NULL);
509 return g_object_new (GST_TYPE_PAD,
510 "name", name, "direction", templ->direction, "template", templ, NULL);
514 * gst_pad_new_from_static_template:
515 * @templ: the #GstStaticPadTemplate to use
516 * @name: the name of the element
518 * Creates a new pad with the given name from the given static template.
519 * If name is NULL, a guaranteed unique name (across all pads)
521 * This function makes a copy of the name so you can safely free the name.
523 * Returns: a new #GstPad, or NULL in case of an error.
526 gst_pad_new_from_static_template (GstStaticPadTemplate * templ,
530 GstPadTemplate *template;
532 template = gst_static_pad_template_get (templ);
533 pad = gst_pad_new_from_template (template, name);
534 gst_object_unref (template);
539 * gst_pad_get_direction:
540 * @pad: a #GstPad to get the direction of.
542 * Gets the direction of the pad. The direction of the pad is
543 * decided at construction time so this function does not take
546 * Returns: the #GstPadDirection of the pad.
551 gst_pad_get_direction (GstPad * pad)
553 GstPadDirection result;
555 /* PAD_UNKNOWN is a little silly but we need some sort of
556 * error return value */
557 g_return_val_if_fail (GST_IS_PAD (pad), GST_PAD_UNKNOWN);
559 GST_OBJECT_LOCK (pad);
560 result = GST_PAD_DIRECTION (pad);
561 GST_OBJECT_UNLOCK (pad);
567 gst_pad_activate_default (GstPad * pad)
569 return gst_pad_activate_push (pad, TRUE);
573 pre_activate (GstPad * pad, GstActivateMode new_mode)
576 case GST_ACTIVATE_PUSH:
577 case GST_ACTIVATE_PULL:
578 GST_OBJECT_LOCK (pad);
579 GST_DEBUG_OBJECT (pad, "setting ACTIVATE_MODE %d, unset flushing",
581 GST_PAD_UNSET_FLUSHING (pad);
582 GST_PAD_ACTIVATE_MODE (pad) = new_mode;
583 GST_OBJECT_UNLOCK (pad);
585 case GST_ACTIVATE_NONE:
586 GST_OBJECT_LOCK (pad);
587 GST_DEBUG_OBJECT (pad, "setting ACTIVATE_MODE NONE, set flushing");
588 GST_PAD_SET_FLUSHING (pad);
589 GST_PAD_ACTIVATE_MODE (pad) = new_mode;
590 /* unlock blocked pads so element can resume and stop */
591 GST_PAD_BLOCK_BROADCAST (pad);
592 GST_OBJECT_UNLOCK (pad);
598 post_activate (GstPad * pad, GstActivateMode new_mode)
601 case GST_ACTIVATE_PUSH:
602 case GST_ACTIVATE_PULL:
605 case GST_ACTIVATE_NONE:
606 /* ensures that streaming stops */
607 GST_PAD_STREAM_LOCK (pad);
608 GST_DEBUG_OBJECT (pad, "stopped streaming");
609 GST_PAD_STREAM_UNLOCK (pad);
615 * gst_pad_set_active:
616 * @pad: the #GstPad to activate or deactivate.
617 * @active: whether or not the pad should be active.
619 * Activates or deactivates the given pad.
620 * Normally called from within core state change functions.
622 * If @active, makes sure the pad is active. If it is already active, either in
623 * push or pull mode, just return. Otherwise dispatches to the pad's activate
624 * function to perform the actual activation.
626 * If not @active, checks the pad's current mode and calls
627 * gst_pad_activate_push() or gst_pad_activate_pull(), as appropriate, with a
630 * Returns: #TRUE if the operation was successful.
635 gst_pad_set_active (GstPad * pad, gboolean active)
638 gboolean ret = FALSE;
640 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
642 GST_OBJECT_LOCK (pad);
643 old = GST_PAD_ACTIVATE_MODE (pad);
644 GST_OBJECT_UNLOCK (pad);
648 case GST_ACTIVATE_PUSH:
649 GST_DEBUG_OBJECT (pad, "activating pad from push");
652 case GST_ACTIVATE_PULL:
653 GST_DEBUG_OBJECT (pad, "activating pad from pull");
656 case GST_ACTIVATE_NONE:
657 GST_DEBUG_OBJECT (pad, "activating pad from none");
658 ret = (GST_PAD_ACTIVATEFUNC (pad)) (pad);
663 case GST_ACTIVATE_PUSH:
664 GST_DEBUG_OBJECT (pad, "deactivating pad from push");
665 ret = gst_pad_activate_push (pad, FALSE);
667 case GST_ACTIVATE_PULL:
668 GST_DEBUG_OBJECT (pad, "deactivating pad from pull");
669 ret = gst_pad_activate_pull (pad, FALSE);
671 case GST_ACTIVATE_NONE:
672 GST_DEBUG_OBJECT (pad, "deactivating pad from none");
679 GST_OBJECT_LOCK (pad);
681 g_critical ("Failed to deactivate pad %s:%s, very bad",
682 GST_DEBUG_PAD_NAME (pad));
684 GST_WARNING_OBJECT (pad, "Failed to activate pad");
686 GST_OBJECT_UNLOCK (pad);
693 * gst_pad_activate_pull:
694 * @pad: the #GstPad to activate or deactivate.
695 * @active: whether or not the pad should be active.
697 * Activates or deactivates the given pad in pull mode via dispatching to the
698 * pad's activatepullfunc. For use from within pad activation functions only.
699 * When called on sink pads, will first proxy the call to the peer pad, which
700 * is expected to activate its internally linked pads from within its
701 * activate_pull function.
703 * If you don't know what this is, you probably don't want to call it.
705 * Returns: TRUE if the operation was successful.
710 gst_pad_activate_pull (GstPad * pad, gboolean active)
712 GstActivateMode old, new;
715 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
717 GST_OBJECT_LOCK (pad);
718 old = GST_PAD_ACTIVATE_MODE (pad);
719 GST_OBJECT_UNLOCK (pad);
723 case GST_ACTIVATE_PULL:
724 GST_DEBUG_OBJECT (pad, "activating pad from pull, was ok");
726 case GST_ACTIVATE_PUSH:
727 GST_DEBUG_OBJECT (pad,
728 "activating pad from push, deactivate push first");
729 /* pad was activate in the wrong direction, deactivate it
730 * and reactivate it in pull mode */
731 if (G_UNLIKELY (!gst_pad_activate_push (pad, FALSE)))
732 goto deactivate_failed;
733 /* fallthrough, pad is deactivated now. */
734 case GST_ACTIVATE_NONE:
735 GST_DEBUG_OBJECT (pad, "activating pad from none");
740 case GST_ACTIVATE_NONE:
741 GST_DEBUG_OBJECT (pad, "deactivating pad from none, was ok");
743 case GST_ACTIVATE_PUSH:
744 GST_DEBUG_OBJECT (pad, "deactivating pad from push, weird");
745 /* pad was activated in the other direction, deactivate it
746 * in push mode, this should not happen... */
747 if (G_UNLIKELY (!gst_pad_activate_push (pad, FALSE)))
748 goto deactivate_failed;
749 /* everything is fine now */
751 case GST_ACTIVATE_PULL:
752 GST_DEBUG_OBJECT (pad, "deactivating pad from pull");
757 if (gst_pad_get_direction (pad) == GST_PAD_SINK) {
758 if ((peer = gst_pad_get_peer (pad))) {
759 GST_DEBUG_OBJECT (pad, "calling peer");
760 if (G_UNLIKELY (!gst_pad_activate_pull (peer, active)))
762 gst_object_unref (peer);
767 if (G_UNLIKELY (GST_PAD_GETRANGEFUNC (pad) == NULL))
768 goto failure; /* Can't activate pull on a src without a
772 new = active ? GST_ACTIVATE_PULL : GST_ACTIVATE_NONE;
773 pre_activate (pad, new);
775 if (GST_PAD_ACTIVATEPULLFUNC (pad)) {
776 if (G_UNLIKELY (!GST_PAD_ACTIVATEPULLFUNC (pad) (pad, active)))
779 /* can happen for sinks of passthrough elements */
782 post_activate (pad, new);
784 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "%s in pull mode",
785 active ? "activated" : "deactivated");
791 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "already %s in pull mode",
792 active ? "activated" : "deactivated");
797 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
798 "failed to %s in switch to pull from mode %d",
799 (active ? "activate" : "deactivate"), old);
804 GST_OBJECT_LOCK (peer);
805 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
806 "activate_pull on peer (%s:%s) failed", GST_DEBUG_PAD_NAME (peer));
807 GST_OBJECT_UNLOCK (peer);
808 gst_object_unref (peer);
813 GST_CAT_INFO_OBJECT (GST_CAT_PADS, pad, "can't activate unlinked sink "
819 GST_OBJECT_LOCK (pad);
820 GST_CAT_INFO_OBJECT (GST_CAT_PADS, pad, "failed to %s in pull mode",
821 active ? "activate" : "deactivate");
822 GST_PAD_SET_FLUSHING (pad);
823 GST_PAD_ACTIVATE_MODE (pad) = old;
824 GST_OBJECT_UNLOCK (pad);
830 * gst_pad_activate_push:
831 * @pad: the #GstPad to activate or deactivate.
832 * @active: whether the pad should be active or not.
834 * Activates or deactivates the given pad in push mode via dispatching to the
835 * pad's activatepushfunc. For use from within pad activation functions only.
837 * If you don't know what this is, you probably don't want to call it.
839 * Returns: %TRUE if the operation was successful.
844 gst_pad_activate_push (GstPad * pad, gboolean active)
846 GstActivateMode old, new;
848 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
849 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "trying to set %s in push mode",
850 active ? "activated" : "deactivated");
852 GST_OBJECT_LOCK (pad);
853 old = GST_PAD_ACTIVATE_MODE (pad);
854 GST_OBJECT_UNLOCK (pad);
858 case GST_ACTIVATE_PUSH:
859 GST_DEBUG_OBJECT (pad, "activating pad from push, was ok");
861 case GST_ACTIVATE_PULL:
862 GST_DEBUG_OBJECT (pad,
863 "activating pad from push, deactivating pull first");
864 /* pad was activate in the wrong direction, deactivate it
865 * an reactivate it in push mode */
866 if (G_UNLIKELY (!gst_pad_activate_pull (pad, FALSE)))
867 goto deactivate_failed;
868 /* fallthrough, pad is deactivated now. */
869 case GST_ACTIVATE_NONE:
870 GST_DEBUG_OBJECT (pad, "activating pad from none");
875 case GST_ACTIVATE_NONE:
876 GST_DEBUG_OBJECT (pad, "deactivating pad from none, was ok");
878 case GST_ACTIVATE_PULL:
879 GST_DEBUG_OBJECT (pad, "deactivating pad from pull, weird");
880 /* pad was activated in the other direction, deactivate it
881 * in pull mode, this should not happen... */
882 if (G_UNLIKELY (!gst_pad_activate_pull (pad, FALSE)))
883 goto deactivate_failed;
884 /* everything is fine now */
886 case GST_ACTIVATE_PUSH:
887 GST_DEBUG_OBJECT (pad, "deactivating pad from push");
892 new = active ? GST_ACTIVATE_PUSH : GST_ACTIVATE_NONE;
893 pre_activate (pad, new);
895 if (GST_PAD_ACTIVATEPUSHFUNC (pad)) {
896 if (G_UNLIKELY (!GST_PAD_ACTIVATEPUSHFUNC (pad) (pad, active))) {
900 /* quite ok, element relies on state change func to prepare itself */
903 post_activate (pad, new);
905 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "%s in push mode",
906 active ? "activated" : "deactivated");
911 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "already %s in push mode",
912 active ? "activated" : "deactivated");
917 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
918 "failed to %s in switch to push from mode %d",
919 (active ? "activate" : "deactivate"), old);
924 GST_OBJECT_LOCK (pad);
925 GST_CAT_INFO_OBJECT (GST_CAT_PADS, pad, "failed to %s in push mode",
926 active ? "activate" : "deactivate");
927 GST_PAD_SET_FLUSHING (pad);
928 GST_PAD_ACTIVATE_MODE (pad) = old;
929 GST_OBJECT_UNLOCK (pad);
936 * @pad: the #GstPad to query
938 * Query if a pad is active
940 * Returns: TRUE if the pad is active.
945 gst_pad_is_active (GstPad * pad)
947 gboolean result = FALSE;
949 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
951 GST_OBJECT_LOCK (pad);
952 result = GST_PAD_MODE_ACTIVATE (GST_PAD_ACTIVATE_MODE (pad));
953 GST_OBJECT_UNLOCK (pad);
959 * gst_pad_set_blocked_async:
960 * @pad: the #GstPad to block or unblock
961 * @blocked: boolean indicating whether the pad should be blocked or unblocked
962 * @callback: #GstPadBlockCallback that will be called when the
964 * @user_data: user data passed to the callback
966 * Blocks or unblocks the dataflow on a pad. The provided callback
967 * is called when the operation succeeds; this happens right before the next
968 * attempt at pushing a buffer on the pad.
970 * This can take a while as the pad can only become blocked when real dataflow
972 * When the pipeline is stalled, for example in PAUSED, this can
973 * take an indeterminate amount of time.
974 * You can pass NULL as the callback to make this call block. Be careful with
975 * this blocking call as it might not return for reasons stated above.
977 * Returns: TRUE if the pad could be blocked. This function can fail if the
978 * wrong parameters were passed or the pad was already in the requested state.
983 gst_pad_set_blocked_async (GstPad * pad, gboolean blocked,
984 GstPadBlockCallback callback, gpointer user_data)
986 gboolean was_blocked = FALSE;
988 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
990 GST_OBJECT_LOCK (pad);
992 was_blocked = GST_PAD_IS_BLOCKED (pad);
994 if (G_UNLIKELY (was_blocked == blocked))
995 goto had_right_state;
998 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "blocking pad");
1000 GST_OBJECT_FLAG_SET (pad, GST_PAD_BLOCKED);
1001 pad->block_callback = callback;
1002 pad->block_data = user_data;
1004 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "waiting for block");
1005 GST_PAD_BLOCK_WAIT (pad);
1006 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "blocked");
1009 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "unblocking pad");
1011 GST_OBJECT_FLAG_UNSET (pad, GST_PAD_BLOCKED);
1013 pad->block_callback = callback;
1014 pad->block_data = user_data;
1016 GST_PAD_BLOCK_BROADCAST (pad);
1018 /* no callback, wait for the unblock to happen */
1019 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "waiting for unblock");
1020 GST_PAD_BLOCK_WAIT (pad);
1021 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "unblocked");
1024 GST_OBJECT_UNLOCK (pad);
1030 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
1031 "pad was in right state (%d)", was_blocked);
1032 GST_OBJECT_UNLOCK (pad);
1039 * gst_pad_set_blocked:
1040 * @pad: the #GstPad to block or unblock
1041 * @blocked: boolean indicating we should block or unblock
1043 * Blocks or unblocks the dataflow on a pad. This function is
1044 * a shortcut for gst_pad_set_blocked_async() with a NULL
1047 * Returns: TRUE if the pad could be blocked. This function can fail if the
1048 * wrong parameters were passed or the pad was already in the requested state.
1053 gst_pad_set_blocked (GstPad * pad, gboolean blocked)
1055 return gst_pad_set_blocked_async (pad, blocked, NULL, NULL);
1059 * gst_pad_is_blocked:
1060 * @pad: the #GstPad to query
1062 * Checks if the pad is blocked or not. This function returns the
1063 * last requested state of the pad. It is not certain that the pad
1064 * is actually blocking at this point (see gst_pad_is_blocking()).
1066 * Returns: TRUE if the pad is blocked.
1071 gst_pad_is_blocked (GstPad * pad)
1073 gboolean result = FALSE;
1075 g_return_val_if_fail (GST_IS_PAD (pad), result);
1077 GST_OBJECT_LOCK (pad);
1078 result = GST_OBJECT_FLAG_IS_SET (pad, GST_PAD_BLOCKED);
1079 GST_OBJECT_UNLOCK (pad);
1085 * gst_pad_is_blocking:
1086 * @pad: the #GstPad to query
1088 * Checks if the pad is blocking or not. This is a guaranteed state
1089 * of whether the pad is actually blocking on a #GstBuffer or a #GstEvent.
1091 * Returns: TRUE if the pad is blocking.
1098 gst_pad_is_blocking (GstPad * pad)
1100 gboolean result = FALSE;
1102 g_return_val_if_fail (GST_IS_PAD (pad), result);
1104 GST_OBJECT_LOCK (pad);
1105 /* the blocking flag is only valid if the pad is not flushing */
1106 result = GST_OBJECT_FLAG_IS_SET (pad, GST_PAD_BLOCKING) &&
1107 !GST_OBJECT_FLAG_IS_SET (pad, GST_PAD_FLUSHING);
1108 GST_OBJECT_UNLOCK (pad);
1114 * gst_pad_set_activate_function:
1116 * @activate: the #GstPadActivateFunction to set.
1118 * Sets the given activate function for @pad. The activate function will
1119 * dispatch to gst_pad_activate_push() or gst_pad_activate_pull() to perform
1120 * the actual activation. Only makes sense to set on sink pads.
1122 * Call this function if your sink pad can start a pull-based task.
1125 gst_pad_set_activate_function (GstPad * pad, GstPadActivateFunction activate)
1127 g_return_if_fail (GST_IS_PAD (pad));
1129 GST_PAD_ACTIVATEFUNC (pad) = activate;
1130 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "activatefunc set to %s",
1131 GST_DEBUG_FUNCPTR_NAME (activate));
1135 * gst_pad_set_activatepull_function:
1137 * @activatepull: the #GstPadActivateModeFunction to set.
1139 * Sets the given activate_pull function for the pad. An activate_pull function
1140 * prepares the element and any upstream connections for pulling. See XXX
1141 * part-activation.txt for details.
1144 gst_pad_set_activatepull_function (GstPad * pad,
1145 GstPadActivateModeFunction activatepull)
1147 g_return_if_fail (GST_IS_PAD (pad));
1149 GST_PAD_ACTIVATEPULLFUNC (pad) = activatepull;
1150 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "activatepullfunc set to %s",
1151 GST_DEBUG_FUNCPTR_NAME (activatepull));
1155 * gst_pad_set_activatepush_function:
1157 * @activatepush: the #GstPadActivateModeFunction to set.
1159 * Sets the given activate_push function for the pad. An activate_push function
1160 * prepares the element for pushing. See XXX part-activation.txt for details.
1163 gst_pad_set_activatepush_function (GstPad * pad,
1164 GstPadActivateModeFunction activatepush)
1166 g_return_if_fail (GST_IS_PAD (pad));
1168 GST_PAD_ACTIVATEPUSHFUNC (pad) = activatepush;
1169 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "activatepushfunc set to %s",
1170 GST_DEBUG_FUNCPTR_NAME (activatepush));
1174 * gst_pad_set_chain_function:
1175 * @pad: a sink #GstPad.
1176 * @chain: the #GstPadChainFunction to set.
1178 * Sets the given chain function for the pad. The chain function is called to
1179 * process a #GstBuffer input buffer. see #GstPadChainFunction for more details.
1182 gst_pad_set_chain_function (GstPad * pad, GstPadChainFunction chain)
1184 g_return_if_fail (GST_IS_PAD (pad));
1185 g_return_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SINK);
1187 GST_PAD_CHAINFUNC (pad) = chain;
1188 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "chainfunc set to %s",
1189 GST_DEBUG_FUNCPTR_NAME (chain));
1193 * gst_pad_set_getrange_function:
1194 * @pad: a source #GstPad.
1195 * @get: the #GstPadGetRangeFunction to set.
1197 * Sets the given getrange function for the pad. The getrange function is
1198 * called to produce a new #GstBuffer to start the processing pipeline. see
1199 * #GstPadGetRangeFunction for a description of the getrange function.
1202 gst_pad_set_getrange_function (GstPad * pad, GstPadGetRangeFunction get)
1204 g_return_if_fail (GST_IS_PAD (pad));
1205 g_return_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SRC);
1207 GST_PAD_GETRANGEFUNC (pad) = get;
1209 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "getrangefunc set to %s",
1210 GST_DEBUG_FUNCPTR_NAME (get));
1214 * gst_pad_set_checkgetrange_function:
1215 * @pad: a source #GstPad.
1216 * @check: the #GstPadCheckGetRangeFunction to set.
1218 * Sets the given checkgetrange function for the pad. Implement this function
1219 * on a pad if you dynamically support getrange based scheduling on the pad.
1222 gst_pad_set_checkgetrange_function (GstPad * pad,
1223 GstPadCheckGetRangeFunction check)
1225 g_return_if_fail (GST_IS_PAD (pad));
1226 g_return_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SRC);
1228 GST_PAD_CHECKGETRANGEFUNC (pad) = check;
1230 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "checkgetrangefunc set to %s",
1231 GST_DEBUG_FUNCPTR_NAME (check));
1235 * gst_pad_set_event_function:
1236 * @pad: a #GstPad of either direction.
1237 * @event: the #GstPadEventFunction to set.
1239 * Sets the given event handler for the pad.
1242 gst_pad_set_event_function (GstPad * pad, GstPadEventFunction event)
1244 g_return_if_fail (GST_IS_PAD (pad));
1246 GST_PAD_EVENTFUNC (pad) = event;
1248 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "eventfunc for set to %s",
1249 GST_DEBUG_FUNCPTR_NAME (event));
1253 * gst_pad_set_query_function:
1254 * @pad: a #GstPad of either direction.
1255 * @query: the #GstPadQueryFunction to set.
1257 * Set the given query function for the pad.
1260 gst_pad_set_query_function (GstPad * pad, GstPadQueryFunction query)
1262 g_return_if_fail (GST_IS_PAD (pad));
1264 GST_PAD_QUERYFUNC (pad) = query;
1266 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "queryfunc set to %s",
1267 GST_DEBUG_FUNCPTR_NAME (query));
1271 * gst_pad_set_query_type_function:
1272 * @pad: a #GstPad of either direction.
1273 * @type_func: the #GstPadQueryTypeFunction to set.
1275 * Set the given query type function for the pad.
1278 gst_pad_set_query_type_function (GstPad * pad,
1279 GstPadQueryTypeFunction type_func)
1281 g_return_if_fail (GST_IS_PAD (pad));
1283 GST_PAD_QUERYTYPEFUNC (pad) = type_func;
1285 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "querytypefunc set to %s",
1286 GST_DEBUG_FUNCPTR_NAME (type_func));
1290 * gst_pad_get_query_types:
1293 * Get an array of supported queries that can be performed
1296 * Returns: a zero-terminated array of #GstQueryType.
1298 const GstQueryType *
1299 gst_pad_get_query_types (GstPad * pad)
1301 GstPadQueryTypeFunction func;
1303 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
1305 if (G_UNLIKELY ((func = GST_PAD_QUERYTYPEFUNC (pad)) == NULL))
1317 gst_pad_get_query_types_dispatcher (GstPad * pad, const GstQueryType ** data)
1319 *data = gst_pad_get_query_types (pad);
1325 * gst_pad_get_query_types_default:
1328 * Invoke the default dispatcher for the query types on
1331 * Returns: an zero-terminated array of #GstQueryType, or NULL if none of the
1332 * internally-linked pads has a query types function.
1334 const GstQueryType *
1335 gst_pad_get_query_types_default (GstPad * pad)
1337 GstQueryType *result = NULL;
1339 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
1341 gst_pad_dispatcher (pad, (GstPadDispatcherFunction)
1342 gst_pad_get_query_types_dispatcher, &result);
1348 * gst_pad_set_internal_link_function:
1349 * @pad: a #GstPad of either direction.
1350 * @intlink: the #GstPadIntLinkFunction to set.
1352 * Sets the given internal link function for the pad.
1355 gst_pad_set_internal_link_function (GstPad * pad, GstPadIntLinkFunction intlink)
1357 g_return_if_fail (GST_IS_PAD (pad));
1359 GST_PAD_INTLINKFUNC (pad) = intlink;
1360 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "internal link set to %s",
1361 GST_DEBUG_FUNCPTR_NAME (intlink));
1365 * gst_pad_set_link_function:
1367 * @link: the #GstPadLinkFunction to set.
1369 * Sets the given link function for the pad. It will be called when
1370 * the pad is linked with another pad.
1372 * The return value #GST_PAD_LINK_OK should be used when the connection can be
1375 * The return value #GST_PAD_LINK_REFUSED should be used when the connection
1376 * cannot be made for some reason.
1378 * If @link is installed on a source pad, it should call the #GstPadLinkFunction
1379 * of the peer sink pad, if present.
1382 gst_pad_set_link_function (GstPad * pad, GstPadLinkFunction link)
1384 g_return_if_fail (GST_IS_PAD (pad));
1386 GST_PAD_LINKFUNC (pad) = link;
1387 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "linkfunc set to %s",
1388 GST_DEBUG_FUNCPTR_NAME (link));
1392 * gst_pad_set_unlink_function:
1394 * @unlink: the #GstPadUnlinkFunction to set.
1396 * Sets the given unlink function for the pad. It will be called
1397 * when the pad is unlinked.
1400 gst_pad_set_unlink_function (GstPad * pad, GstPadUnlinkFunction unlink)
1402 g_return_if_fail (GST_IS_PAD (pad));
1404 GST_PAD_UNLINKFUNC (pad) = unlink;
1405 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "unlinkfunc set to %s",
1406 GST_DEBUG_FUNCPTR_NAME (unlink));
1410 * gst_pad_set_getcaps_function:
1412 * @getcaps: the #GstPadGetCapsFunction to set.
1414 * Sets the given getcaps function for the pad. @getcaps should return the
1415 * allowable caps for a pad in the context of the element's state, its link to
1416 * other elements, and the devices or files it has opened. These caps must be a
1417 * subset of the pad template caps. In the NULL state with no links, @getcaps
1418 * should ideally return the same caps as the pad template. In rare
1419 * circumstances, an object property can affect the caps returned by @getcaps,
1420 * but this is discouraged.
1422 * You do not need to call this function if @pad's allowed caps are always the
1423 * same as the pad template caps. This can only be true if the padtemplate
1424 * has fixed simple caps.
1426 * For most filters, the caps returned by @getcaps is directly affected by the
1427 * allowed caps on other pads. For demuxers and decoders, the caps returned by
1428 * the srcpad's getcaps function is directly related to the stream data. Again,
1429 * @getcaps should return the most specific caps it reasonably can, since this
1430 * helps with autoplugging.
1432 * Note that the return value from @getcaps is owned by the caller, so the
1433 * caller should unref the caps after usage.
1436 gst_pad_set_getcaps_function (GstPad * pad, GstPadGetCapsFunction getcaps)
1438 g_return_if_fail (GST_IS_PAD (pad));
1440 GST_PAD_GETCAPSFUNC (pad) = getcaps;
1441 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "getcapsfunc set to %s",
1442 GST_DEBUG_FUNCPTR_NAME (getcaps));
1446 * gst_pad_set_acceptcaps_function:
1448 * @acceptcaps: the #GstPadAcceptCapsFunction to set.
1450 * Sets the given acceptcaps function for the pad. The acceptcaps function
1451 * will be called to check if the pad can accept the given caps. Setting the
1452 * acceptcaps function to NULL restores the default behaviour of allowing
1453 * any caps that matches the caps from gst_pad_get_caps.
1456 gst_pad_set_acceptcaps_function (GstPad * pad,
1457 GstPadAcceptCapsFunction acceptcaps)
1459 g_return_if_fail (GST_IS_PAD (pad));
1461 GST_PAD_ACCEPTCAPSFUNC (pad) = acceptcaps;
1462 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "acceptcapsfunc set to %s",
1463 GST_DEBUG_FUNCPTR_NAME (acceptcaps));
1467 * gst_pad_set_fixatecaps_function:
1469 * @fixatecaps: the #GstPadFixateCapsFunction to set.
1471 * Sets the given fixatecaps function for the pad. The fixatecaps function
1472 * will be called whenever the default values for a GstCaps needs to be
1476 gst_pad_set_fixatecaps_function (GstPad * pad,
1477 GstPadFixateCapsFunction fixatecaps)
1479 g_return_if_fail (GST_IS_PAD (pad));
1481 GST_PAD_FIXATECAPSFUNC (pad) = fixatecaps;
1482 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "fixatecapsfunc set to %s",
1483 GST_DEBUG_FUNCPTR_NAME (fixatecaps));
1487 * gst_pad_set_setcaps_function:
1489 * @setcaps: the #GstPadSetCapsFunction to set.
1491 * Sets the given setcaps function for the pad. The setcaps function
1492 * will be called whenever a buffer with a new media type is pushed or
1493 * pulled from the pad. The pad/element needs to update its internal
1494 * structures to process the new media type. If this new type is not
1495 * acceptable, the setcaps function should return FALSE.
1498 gst_pad_set_setcaps_function (GstPad * pad, GstPadSetCapsFunction setcaps)
1500 g_return_if_fail (GST_IS_PAD (pad));
1502 GST_PAD_SETCAPSFUNC (pad) = setcaps;
1503 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "setcapsfunc set to %s",
1504 GST_DEBUG_FUNCPTR_NAME (setcaps));
1508 * gst_pad_set_bufferalloc_function:
1509 * @pad: a sink #GstPad.
1510 * @bufalloc: the #GstPadBufferAllocFunction to set.
1512 * Sets the given bufferalloc function for the pad. Note that the
1513 * bufferalloc function can only be set on sinkpads.
1516 gst_pad_set_bufferalloc_function (GstPad * pad,
1517 GstPadBufferAllocFunction bufalloc)
1519 g_return_if_fail (GST_IS_PAD (pad));
1520 g_return_if_fail (GST_PAD_IS_SINK (pad));
1522 GST_PAD_BUFFERALLOCFUNC (pad) = bufalloc;
1523 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "bufferallocfunc set to %s",
1524 GST_DEBUG_FUNCPTR_NAME (bufalloc));
1529 * @srcpad: the source #GstPad to unlink.
1530 * @sinkpad: the sink #GstPad to unlink.
1532 * Unlinks the source pad from the sink pad. Will emit the #GstPad::unlinked
1533 * signal on both pads.
1535 * Returns: TRUE if the pads were unlinked. This function returns FALSE if
1536 * the pads were not linked together.
1541 gst_pad_unlink (GstPad * srcpad, GstPad * sinkpad)
1543 g_return_val_if_fail (GST_IS_PAD (srcpad), FALSE);
1544 g_return_val_if_fail (GST_IS_PAD (sinkpad), FALSE);
1546 GST_CAT_INFO (GST_CAT_ELEMENT_PADS, "unlinking %s:%s(%p) and %s:%s(%p)",
1547 GST_DEBUG_PAD_NAME (srcpad), srcpad,
1548 GST_DEBUG_PAD_NAME (sinkpad), sinkpad);
1550 GST_OBJECT_LOCK (srcpad);
1552 if (G_UNLIKELY (GST_PAD_DIRECTION (srcpad) != GST_PAD_SRC))
1555 GST_OBJECT_LOCK (sinkpad);
1557 if (G_UNLIKELY (GST_PAD_DIRECTION (sinkpad) != GST_PAD_SINK))
1560 if (G_UNLIKELY (GST_PAD_PEER (srcpad) != sinkpad))
1561 goto not_linked_together;
1563 if (GST_PAD_UNLINKFUNC (srcpad)) {
1564 GST_PAD_UNLINKFUNC (srcpad) (srcpad);
1566 if (GST_PAD_UNLINKFUNC (sinkpad)) {
1567 GST_PAD_UNLINKFUNC (sinkpad) (sinkpad);
1570 /* first clear peers */
1571 GST_PAD_PEER (srcpad) = NULL;
1572 GST_PAD_PEER (sinkpad) = NULL;
1574 GST_OBJECT_UNLOCK (sinkpad);
1575 GST_OBJECT_UNLOCK (srcpad);
1577 /* fire off a signal to each of the pads telling them
1578 * that they've been unlinked */
1579 g_signal_emit (G_OBJECT (srcpad), gst_pad_signals[PAD_UNLINKED], 0, sinkpad);
1580 g_signal_emit (G_OBJECT (sinkpad), gst_pad_signals[PAD_UNLINKED], 0, srcpad);
1582 GST_CAT_INFO (GST_CAT_ELEMENT_PADS, "unlinked %s:%s and %s:%s",
1583 GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (sinkpad));
1589 g_critical ("pad %s is not a source pad", GST_PAD_NAME (srcpad));
1590 GST_OBJECT_UNLOCK (srcpad);
1595 g_critical ("pad %s is not a sink pad", GST_PAD_NAME (sinkpad));
1596 GST_OBJECT_UNLOCK (sinkpad);
1597 GST_OBJECT_UNLOCK (srcpad);
1600 not_linked_together:
1602 /* we do not emit a warning in this case because unlinking cannot
1603 * be made MT safe.*/
1604 GST_OBJECT_UNLOCK (sinkpad);
1605 GST_OBJECT_UNLOCK (srcpad);
1611 * gst_pad_is_linked:
1612 * @pad: pad to check
1614 * Checks if a @pad is linked to another pad or not.
1616 * Returns: TRUE if the pad is linked, FALSE otherwise.
1621 gst_pad_is_linked (GstPad * pad)
1625 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
1627 GST_OBJECT_LOCK (pad);
1628 result = (GST_PAD_PEER (pad) != NULL);
1629 GST_OBJECT_UNLOCK (pad);
1634 /* get the caps from both pads and see if the intersection
1637 * This function should be called with the pad LOCK on both
1641 gst_pad_link_check_compatible_unlocked (GstPad * src, GstPad * sink)
1647 srccaps = gst_pad_get_caps_unlocked (src);
1648 sinkcaps = gst_pad_get_caps_unlocked (sink);
1650 GST_CAT_DEBUG (GST_CAT_CAPS, "src caps %" GST_PTR_FORMAT, srccaps);
1651 GST_CAT_DEBUG (GST_CAT_CAPS, "sink caps %" GST_PTR_FORMAT, sinkcaps);
1653 /* if we have caps on both pads we can check the intersection. If one
1654 * of the caps is NULL, we return TRUE. */
1655 if (srccaps == NULL || sinkcaps == NULL)
1658 icaps = gst_caps_intersect (srccaps, sinkcaps);
1659 gst_caps_unref (srccaps);
1660 gst_caps_unref (sinkcaps);
1665 GST_CAT_DEBUG (GST_CAT_CAPS,
1666 "intersection caps %p %" GST_PTR_FORMAT, icaps, icaps);
1668 if (gst_caps_is_empty (icaps))
1671 gst_caps_unref (icaps);
1676 /* incompatible cases */
1679 GST_CAT_DEBUG (GST_CAT_CAPS, "intersection gave NULL");
1684 GST_CAT_DEBUG (GST_CAT_CAPS, "intersection is EMPTY");
1685 gst_caps_unref (icaps);
1690 /* check if the grandparents of both pads are the same.
1691 * This check is required so that we don't try to link
1692 * pads from elements in different bins without ghostpads.
1694 * The LOCK should be held on both pads
1697 gst_pad_link_check_hierarchy (GstPad * src, GstPad * sink)
1699 GstObject *psrc, *psink;
1701 psrc = GST_OBJECT_PARENT (src);
1702 psink = GST_OBJECT_PARENT (sink);
1704 /* if one of the pads has no parent, we allow the link */
1705 if (G_UNLIKELY (psrc == NULL || psink == NULL))
1708 /* only care about parents that are elements */
1709 if (G_UNLIKELY (!GST_IS_ELEMENT (psrc) || !GST_IS_ELEMENT (psink)))
1710 goto no_element_parent;
1712 /* if the parents are the same, we have a loop */
1713 if (G_UNLIKELY (psrc == psink))
1716 /* if they both have a parent, we check the grandparents. We can not lock
1717 * the parent because we hold on the child (pad) and the locking order is
1718 * parent >> child. */
1719 psrc = GST_OBJECT_PARENT (psrc);
1720 psink = GST_OBJECT_PARENT (psink);
1722 /* if they have grandparents but they are not the same */
1723 if (G_UNLIKELY (psrc != psink))
1724 goto wrong_grandparents;
1731 GST_CAT_DEBUG (GST_CAT_CAPS,
1732 "one of the pads has no parent %" GST_PTR_FORMAT " and %"
1733 GST_PTR_FORMAT, psrc, psink);
1738 GST_CAT_DEBUG (GST_CAT_CAPS,
1739 "one of the pads has no element parent %" GST_PTR_FORMAT " and %"
1740 GST_PTR_FORMAT, psrc, psink);
1745 GST_CAT_DEBUG (GST_CAT_CAPS, "pads have same parent %" GST_PTR_FORMAT,
1751 GST_CAT_DEBUG (GST_CAT_CAPS,
1752 "pads have different grandparents %" GST_PTR_FORMAT " and %"
1753 GST_PTR_FORMAT, psrc, psink);
1758 /* FIXME leftover from an attempt at refactoring... */
1759 /* call with the two pads unlocked, when this function returns GST_PAD_LINK_OK,
1760 * the two pads will be locked in the srcpad, sinkpad order. */
1761 static GstPadLinkReturn
1762 gst_pad_link_prepare (GstPad * srcpad, GstPad * sinkpad)
1764 /* generic checks */
1765 g_return_val_if_fail (GST_IS_PAD (srcpad), GST_PAD_LINK_REFUSED);
1766 g_return_val_if_fail (GST_IS_PAD (sinkpad), GST_PAD_LINK_REFUSED);
1768 GST_CAT_INFO (GST_CAT_PADS, "trying to link %s:%s and %s:%s",
1769 GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (sinkpad));
1771 GST_OBJECT_LOCK (srcpad);
1773 if (G_UNLIKELY (GST_PAD_DIRECTION (srcpad) != GST_PAD_SRC))
1776 if (G_UNLIKELY (GST_PAD_PEER (srcpad) != NULL))
1777 goto src_was_linked;
1779 GST_OBJECT_LOCK (sinkpad);
1781 if (G_UNLIKELY (GST_PAD_DIRECTION (sinkpad) != GST_PAD_SINK))
1784 if (G_UNLIKELY (GST_PAD_PEER (sinkpad) != NULL))
1785 goto sink_was_linked;
1787 /* check hierarchy, pads can only be linked if the grandparents
1789 if (!gst_pad_link_check_hierarchy (srcpad, sinkpad))
1790 goto wrong_hierarchy;
1792 /* check pad caps for non-empty intersection */
1793 if (!gst_pad_link_check_compatible_unlocked (srcpad, sinkpad))
1796 /* FIXME check pad scheduling for non-empty intersection */
1798 return GST_PAD_LINK_OK;
1802 g_critical ("pad %s is not a source pad", GST_PAD_NAME (srcpad));
1803 GST_OBJECT_UNLOCK (srcpad);
1804 return GST_PAD_LINK_WRONG_DIRECTION;
1808 GST_CAT_INFO (GST_CAT_PADS, "src %s:%s was already linked to %s:%s",
1809 GST_DEBUG_PAD_NAME (srcpad),
1810 GST_DEBUG_PAD_NAME (GST_PAD_PEER (srcpad)));
1811 /* we do not emit a warning in this case because unlinking cannot
1812 * be made MT safe.*/
1813 GST_OBJECT_UNLOCK (srcpad);
1814 return GST_PAD_LINK_WAS_LINKED;
1818 g_critical ("pad %s is not a sink pad", GST_PAD_NAME (sinkpad));
1819 GST_OBJECT_UNLOCK (sinkpad);
1820 GST_OBJECT_UNLOCK (srcpad);
1821 return GST_PAD_LINK_WRONG_DIRECTION;
1825 GST_CAT_INFO (GST_CAT_PADS, "sink %s:%s was already linked to %s:%s",
1826 GST_DEBUG_PAD_NAME (sinkpad),
1827 GST_DEBUG_PAD_NAME (GST_PAD_PEER (sinkpad)));
1828 /* we do not emit a warning in this case because unlinking cannot
1829 * be made MT safe.*/
1830 GST_OBJECT_UNLOCK (sinkpad);
1831 GST_OBJECT_UNLOCK (srcpad);
1832 return GST_PAD_LINK_WAS_LINKED;
1836 GST_CAT_INFO (GST_CAT_PADS, "pads have wrong hierarchy");
1837 GST_OBJECT_UNLOCK (sinkpad);
1838 GST_OBJECT_UNLOCK (srcpad);
1839 return GST_PAD_LINK_WRONG_HIERARCHY;
1843 GST_CAT_INFO (GST_CAT_PADS, "caps are incompatible");
1844 GST_OBJECT_UNLOCK (sinkpad);
1845 GST_OBJECT_UNLOCK (srcpad);
1846 return GST_PAD_LINK_NOFORMAT;
1852 * @srcpad: the source #GstPad to link.
1853 * @sinkpad: the sink #GstPad to link.
1855 * Links the source pad and the sink pad.
1857 * Returns: A result code indicating if the connection worked or
1863 gst_pad_link (GstPad * srcpad, GstPad * sinkpad)
1865 GstPadLinkReturn result;
1867 /* prepare will also lock the two pads */
1868 result = gst_pad_link_prepare (srcpad, sinkpad);
1870 if (result != GST_PAD_LINK_OK)
1871 goto prepare_failed;
1873 /* must set peers before calling the link function */
1874 GST_PAD_PEER (srcpad) = sinkpad;
1875 GST_PAD_PEER (sinkpad) = srcpad;
1877 GST_OBJECT_UNLOCK (sinkpad);
1878 GST_OBJECT_UNLOCK (srcpad);
1880 /* FIXME released the locks here, concurrent thread might link
1881 * something else. */
1882 if (GST_PAD_LINKFUNC (srcpad)) {
1883 /* this one will call the peer link function */
1884 result = GST_PAD_LINKFUNC (srcpad) (srcpad, sinkpad);
1885 } else if (GST_PAD_LINKFUNC (sinkpad)) {
1886 /* if no source link function, we need to call the sink link
1887 * function ourselves. */
1888 result = GST_PAD_LINKFUNC (sinkpad) (sinkpad, srcpad);
1890 result = GST_PAD_LINK_OK;
1893 GST_OBJECT_LOCK (srcpad);
1894 GST_OBJECT_LOCK (sinkpad);
1896 if (result == GST_PAD_LINK_OK) {
1897 GST_OBJECT_UNLOCK (sinkpad);
1898 GST_OBJECT_UNLOCK (srcpad);
1900 /* fire off a signal to each of the pads telling them
1901 * that they've been linked */
1902 g_signal_emit (G_OBJECT (srcpad), gst_pad_signals[PAD_LINKED], 0, sinkpad);
1903 g_signal_emit (G_OBJECT (sinkpad), gst_pad_signals[PAD_LINKED], 0, srcpad);
1905 GST_CAT_INFO (GST_CAT_PADS, "linked %s:%s and %s:%s, successful",
1906 GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (sinkpad));
1908 GST_CAT_INFO (GST_CAT_PADS, "link between %s:%s and %s:%s failed",
1909 GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (sinkpad));
1911 GST_PAD_PEER (srcpad) = NULL;
1912 GST_PAD_PEER (sinkpad) = NULL;
1914 GST_OBJECT_UNLOCK (sinkpad);
1915 GST_OBJECT_UNLOCK (srcpad);
1926 gst_pad_set_pad_template (GstPad * pad, GstPadTemplate * templ)
1928 GstPadTemplate **template_p;
1930 /* this function would need checks if it weren't static */
1932 GST_OBJECT_LOCK (pad);
1933 template_p = &pad->padtemplate;
1934 gst_object_replace ((GstObject **) template_p, (GstObject *) templ);
1935 GST_OBJECT_UNLOCK (pad);
1938 gst_pad_template_pad_created (templ, pad);
1942 * gst_pad_get_pad_template:
1945 * Gets the template for @pad.
1947 * Returns: the #GstPadTemplate from which this pad was instantiated, or %NULL
1948 * if this pad has no template.
1950 * FIXME: currently returns an unrefcounted padtemplate.
1953 gst_pad_get_pad_template (GstPad * pad)
1955 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
1957 return GST_PAD_PAD_TEMPLATE (pad);
1961 /* should be called with the pad LOCK held */
1962 /* refs the caps, so caller is responsible for getting it unreffed */
1964 gst_pad_get_caps_unlocked (GstPad * pad)
1966 GstCaps *result = NULL;
1967 GstPadTemplate *templ;
1969 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "get pad caps");
1971 if (GST_PAD_GETCAPSFUNC (pad)) {
1972 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
1973 "dispatching to pad getcaps function");
1975 GST_OBJECT_FLAG_SET (pad, GST_PAD_IN_GETCAPS);
1976 GST_OBJECT_UNLOCK (pad);
1977 result = GST_PAD_GETCAPSFUNC (pad) (pad);
1978 GST_OBJECT_LOCK (pad);
1979 GST_OBJECT_FLAG_UNSET (pad, GST_PAD_IN_GETCAPS);
1981 if (result == NULL) {
1982 g_critical ("pad %s:%s returned NULL caps from getcaps function",
1983 GST_DEBUG_PAD_NAME (pad));
1985 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
1986 "pad getcaps returned %" GST_PTR_FORMAT, result);
1987 #ifndef G_DISABLE_ASSERT
1988 /* check that the returned caps are a real subset of the template caps */
1989 if (GST_PAD_PAD_TEMPLATE (pad)) {
1990 const GstCaps *templ_caps =
1991 GST_PAD_TEMPLATE_CAPS (GST_PAD_PAD_TEMPLATE (pad));
1992 if (!gst_caps_is_subset (result, templ_caps)) {
1995 GST_CAT_ERROR_OBJECT (GST_CAT_CAPS, pad,
1996 "pad returned caps %" GST_PTR_FORMAT
1997 " which are not a real subset of its template caps %"
1998 GST_PTR_FORMAT, result, templ_caps);
2000 ("pad %s:%s returned caps which are not a real "
2001 "subset of its template caps", GST_DEBUG_PAD_NAME (pad));
2002 temp = gst_caps_intersect (templ_caps, result);
2003 gst_caps_unref (result);
2011 if ((templ = GST_PAD_PAD_TEMPLATE (pad))) {
2012 result = GST_PAD_TEMPLATE_CAPS (templ);
2013 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
2014 "using pad template %p with caps %p %" GST_PTR_FORMAT, templ, result,
2017 result = gst_caps_ref (result);
2020 if ((result = GST_PAD_CAPS (pad))) {
2021 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
2022 "using pad caps %p %" GST_PTR_FORMAT, result, result);
2024 result = gst_caps_ref (result);
2028 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "pad has no caps");
2029 result = gst_caps_new_empty ();
2037 * @pad: a #GstPad to get the capabilities of.
2039 * Gets the capabilities this pad can produce or consume.
2040 * Note that this method doesn't necessarily return the caps set by
2041 * gst_pad_set_caps() - use GST_PAD_CAPS() for that instead.
2042 * gst_pad_get_caps returns all possible caps a pad can operate with, using
2043 * the pad's get_caps function;
2044 * this returns the pad template caps if not explicitly set.
2046 * Returns: a newly allocated copy of the #GstCaps of this pad.
2051 gst_pad_get_caps (GstPad * pad)
2053 GstCaps *result = NULL;
2055 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2057 GST_OBJECT_LOCK (pad);
2059 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "get pad caps");
2061 result = gst_pad_get_caps_unlocked (pad);
2063 /* be sure that we have a copy */
2065 result = gst_caps_make_writable (result);
2067 GST_OBJECT_UNLOCK (pad);
2073 * gst_pad_peer_get_caps:
2074 * @pad: a #GstPad to get the peer capabilities of.
2076 * Gets the capabilities of the peer connected to this pad.
2078 * Returns: the #GstCaps of the peer pad. This function returns a new caps, so
2079 * use gst_caps_unref to get rid of it. this function returns NULL if there is
2083 gst_pad_peer_get_caps (GstPad * pad)
2086 GstCaps *result = NULL;
2088 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2090 GST_OBJECT_LOCK (pad);
2092 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "get peer caps");
2094 peerpad = GST_PAD_PEER (pad);
2095 if (G_UNLIKELY (peerpad == NULL))
2098 gst_object_ref (peerpad);
2099 GST_OBJECT_UNLOCK (pad);
2101 result = gst_pad_get_caps (peerpad);
2103 gst_object_unref (peerpad);
2109 GST_OBJECT_UNLOCK (pad);
2115 fixate_value (GValue * dest, const GValue * src)
2117 if (G_VALUE_TYPE (src) == GST_TYPE_INT_RANGE) {
2118 g_value_init (dest, G_TYPE_INT);
2119 g_value_set_int (dest, gst_value_get_int_range_min (src));
2120 } else if (G_VALUE_TYPE (src) == GST_TYPE_DOUBLE_RANGE) {
2121 g_value_init (dest, G_TYPE_DOUBLE);
2122 g_value_set_double (dest, gst_value_get_double_range_min (src));
2123 } else if (G_VALUE_TYPE (src) == GST_TYPE_FRACTION_RANGE) {
2124 gst_value_init_and_copy (dest, gst_value_get_fraction_range_min (src));
2125 } else if (G_VALUE_TYPE (src) == GST_TYPE_LIST) {
2126 GValue temp = { 0 };
2128 /* list could be empty */
2129 if (gst_value_list_get_size (src) <= 0)
2132 gst_value_init_and_copy (&temp, gst_value_list_get_value (src, 0));
2134 if (!fixate_value (dest, &temp))
2135 gst_value_init_and_copy (dest, &temp);
2136 g_value_unset (&temp);
2137 } else if (G_VALUE_TYPE (src) == GST_TYPE_ARRAY) {
2138 gboolean res = FALSE;
2141 g_value_init (dest, GST_TYPE_ARRAY);
2142 for (n = 0; n < gst_value_array_get_size (src); n++) {
2144 const GValue *orig_kid = gst_value_array_get_value (src, n);
2146 if (!fixate_value (&kid, orig_kid))
2147 gst_value_init_and_copy (&kid, orig_kid);
2150 gst_value_array_append_value (dest, &kid);
2151 g_value_unset (&kid);
2155 g_value_unset (dest);
2166 gst_pad_default_fixate (GQuark field_id, const GValue * value, gpointer data)
2168 GstStructure *s = data;
2171 if (fixate_value (&v, value)) {
2172 gst_structure_id_set_value (s, field_id, &v);
2180 * gst_pad_fixate_caps:
2181 * @pad: a #GstPad to fixate
2182 * @caps: the #GstCaps to fixate
2184 * Fixate a caps on the given pad. Modifies the caps in place, so you should
2185 * make sure that the caps are actually writable (see gst_caps_make_writable()).
2188 gst_pad_fixate_caps (GstPad * pad, GstCaps * caps)
2190 GstPadFixateCapsFunction fixatefunc;
2193 g_return_if_fail (GST_IS_PAD (pad));
2194 g_return_if_fail (caps != NULL);
2196 if (gst_caps_is_fixed (caps))
2199 fixatefunc = GST_PAD_FIXATECAPSFUNC (pad);
2201 fixatefunc (pad, caps);
2204 /* default fixation */
2205 for (n = 0; n < gst_caps_get_size (caps); n++) {
2206 GstStructure *s = gst_caps_get_structure (caps, n);
2208 gst_structure_foreach (s, gst_pad_default_fixate, s);
2212 /* Default accept caps implementation just checks against
2213 * against the allowed caps for the pad */
2215 gst_pad_acceptcaps_default (GstPad * pad, GstCaps * caps)
2217 /* get the caps and see if it intersects to something
2221 gboolean result = FALSE;
2223 GST_DEBUG_OBJECT (pad, "caps %" GST_PTR_FORMAT, caps);
2225 allowed = gst_pad_get_caps (pad);
2227 goto nothing_allowed;
2229 GST_DEBUG_OBJECT (pad, "allowed caps %" GST_PTR_FORMAT, allowed);
2231 intersect = gst_caps_intersect (allowed, caps);
2233 GST_DEBUG_OBJECT (pad, "intersection %" GST_PTR_FORMAT, intersect);
2235 result = !gst_caps_is_empty (intersect);
2237 GST_DEBUG_OBJECT (pad, "intersection gave empty caps");
2239 gst_caps_unref (allowed);
2240 gst_caps_unref (intersect);
2247 GST_DEBUG_OBJECT (pad, "no caps allowed on the pad");
2253 * gst_pad_accept_caps:
2254 * @pad: a #GstPad to check
2255 * @caps: a #GstCaps to check on the pad
2257 * Check if the given pad accepts the caps.
2259 * Returns: TRUE if the pad can accept the caps.
2262 gst_pad_accept_caps (GstPad * pad, GstCaps * caps)
2265 GstPadAcceptCapsFunction acceptfunc;
2266 GstCaps *existing = NULL;
2268 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2270 /* any pad can be unnegotiated */
2274 /* lock for checking the existing caps */
2275 GST_OBJECT_LOCK (pad);
2276 acceptfunc = GST_PAD_ACCEPTCAPSFUNC (pad);
2277 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "accept caps of %p", caps);
2278 /* The current caps on a pad are trivially acceptable */
2279 if (G_LIKELY ((existing = GST_PAD_CAPS (pad)))) {
2280 if (caps == existing || gst_caps_is_equal (caps, existing))
2283 GST_OBJECT_UNLOCK (pad);
2285 if (G_LIKELY (acceptfunc)) {
2286 /* we can call the function */
2287 result = acceptfunc (pad, caps);
2288 GST_DEBUG_OBJECT (pad, "acceptfunc returned %d", result);
2290 /* Only null if the element explicitly unset it */
2291 result = gst_pad_acceptcaps_default (pad, caps);
2292 GST_DEBUG_OBJECT (pad, "default acceptcaps returned %d", result);
2298 GST_DEBUG_OBJECT (pad, "pad had same caps");
2299 GST_OBJECT_UNLOCK (pad);
2305 * gst_pad_peer_accept_caps:
2306 * @pad: a #GstPad to check the peer of
2307 * @caps: a #GstCaps to check on the pad
2309 * Check if the peer of @pad accepts @caps. If @pad has no peer, this function
2312 * Returns: TRUE if the peer of @pad can accept the caps or @pad has no peer.
2315 gst_pad_peer_accept_caps (GstPad * pad, GstCaps * caps)
2320 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2322 GST_OBJECT_LOCK (pad);
2324 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "peer accept caps of (%p)", pad);
2326 peerpad = GST_PAD_PEER (pad);
2327 if (G_UNLIKELY (peerpad == NULL))
2330 result = gst_pad_accept_caps (peerpad, caps);
2331 GST_OBJECT_UNLOCK (pad);
2337 GST_OBJECT_UNLOCK (pad);
2344 * @pad: a #GstPad to set the capabilities of.
2345 * @caps: a #GstCaps to set.
2347 * Sets the capabilities of this pad. The caps must be fixed. Any previous
2348 * caps on the pad will be unreffed. This function refs the caps so you should
2349 * unref if as soon as you don't need it anymore.
2350 * It is possible to set NULL caps, which will make the pad unnegotiated
2353 * Returns: TRUE if the caps could be set. FALSE if the caps were not fixed
2354 * or bad parameters were provided to this function.
2359 gst_pad_set_caps (GstPad * pad, GstCaps * caps)
2361 GstPadSetCapsFunction setcaps;
2364 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2365 g_return_val_if_fail (caps == NULL || gst_caps_is_fixed (caps), FALSE);
2367 GST_OBJECT_LOCK (pad);
2368 existing = GST_PAD_CAPS (pad);
2369 if (existing == caps)
2372 if (gst_caps_is_equal (caps, existing))
2373 goto setting_same_caps;
2375 setcaps = GST_PAD_SETCAPSFUNC (pad);
2377 /* call setcaps function to configure the pad only if the
2378 * caps is not NULL */
2379 if (setcaps != NULL && caps) {
2380 if (!GST_PAD_IS_IN_SETCAPS (pad)) {
2381 GST_OBJECT_FLAG_SET (pad, GST_PAD_IN_SETCAPS);
2382 GST_OBJECT_UNLOCK (pad);
2383 if (!setcaps (pad, caps))
2385 GST_OBJECT_LOCK (pad);
2386 GST_OBJECT_FLAG_UNSET (pad, GST_PAD_IN_SETCAPS);
2388 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "pad was dispatching");
2392 gst_caps_replace (&GST_PAD_CAPS (pad), caps);
2393 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "caps %" GST_PTR_FORMAT, caps);
2394 GST_OBJECT_UNLOCK (pad);
2396 g_object_notify (G_OBJECT (pad), "caps");
2402 GST_OBJECT_UNLOCK (pad);
2407 gst_caps_replace (&GST_PAD_CAPS (pad), caps);
2408 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
2409 "caps %" GST_PTR_FORMAT " same as existing, updating ptr only", caps);
2410 GST_OBJECT_UNLOCK (pad);
2417 GST_OBJECT_LOCK (pad);
2418 GST_OBJECT_FLAG_UNSET (pad, GST_PAD_IN_SETCAPS);
2419 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
2420 "caps %" GST_PTR_FORMAT " could not be set", caps);
2421 GST_OBJECT_UNLOCK (pad);
2428 gst_pad_configure_sink (GstPad * pad, GstCaps * caps)
2432 /* See if pad accepts the caps */
2433 if (!gst_pad_accept_caps (pad, caps))
2436 /* set caps on pad if call succeeds */
2437 res = gst_pad_set_caps (pad, caps);
2438 /* no need to unref the caps here, set_caps takes a ref and
2439 * our ref goes away when we leave this function. */
2445 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
2446 "caps %" GST_PTR_FORMAT " not accepted", caps);
2451 /* returns TRUE if the src pad could be configured to accept the given caps */
2453 gst_pad_configure_src (GstPad * pad, GstCaps * caps, gboolean dosetcaps)
2457 /* See if pad accepts the caps */
2458 if (!gst_pad_accept_caps (pad, caps))
2462 res = gst_pad_set_caps (pad, caps);
2470 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
2471 "caps %" GST_PTR_FORMAT " not accepted", caps);
2477 * gst_pad_get_pad_template_caps:
2478 * @pad: a #GstPad to get the template capabilities from.
2480 * Gets the capabilities for @pad's template.
2482 * Returns: the #GstCaps of this pad template. If you intend to keep a
2483 * reference on the caps, make a copy (see gst_caps_copy ()).
2486 gst_pad_get_pad_template_caps (GstPad * pad)
2488 static GstStaticCaps anycaps = GST_STATIC_CAPS ("ANY");
2490 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2492 if (GST_PAD_PAD_TEMPLATE (pad))
2493 return GST_PAD_TEMPLATE_CAPS (GST_PAD_PAD_TEMPLATE (pad));
2495 return gst_static_caps_get (&anycaps);
2500 * @pad: a #GstPad to get the peer of.
2502 * Gets the peer of @pad. This function refs the peer pad so
2503 * you need to unref it after use.
2505 * Returns: the peer #GstPad. Unref after usage.
2510 gst_pad_get_peer (GstPad * pad)
2514 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2516 GST_OBJECT_LOCK (pad);
2517 result = GST_PAD_PEER (pad);
2519 gst_object_ref (result);
2520 GST_OBJECT_UNLOCK (pad);
2526 * gst_pad_get_allowed_caps:
2529 * Gets the capabilities of the allowed media types that can flow through
2530 * @pad and its peer.
2532 * The allowed capabilities is calculated as the intersection of the results of
2533 * calling gst_pad_get_caps() on @pad and its peer. The caller owns a reference
2534 * on the resulting caps.
2536 * Returns: the allowed #GstCaps of the pad link. Unref the caps when you no
2537 * longer need it. This function returns NULL when @pad has no peer.
2542 gst_pad_get_allowed_caps (GstPad * pad)
2549 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2551 GST_OBJECT_LOCK (pad);
2553 peer = GST_PAD_PEER (pad);
2554 if (G_UNLIKELY (peer == NULL))
2557 GST_CAT_DEBUG_OBJECT (GST_CAT_PROPERTIES, pad, "getting allowed caps");
2559 gst_object_ref (peer);
2560 GST_OBJECT_UNLOCK (pad);
2561 mycaps = gst_pad_get_caps (pad);
2563 peercaps = gst_pad_get_caps (peer);
2564 gst_object_unref (peer);
2566 caps = gst_caps_intersect (mycaps, peercaps);
2567 gst_caps_unref (peercaps);
2568 gst_caps_unref (mycaps);
2570 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "allowed caps %" GST_PTR_FORMAT,
2577 GST_CAT_DEBUG_OBJECT (GST_CAT_PROPERTIES, pad, "no peer");
2578 GST_OBJECT_UNLOCK (pad);
2585 * gst_pad_get_negotiated_caps:
2588 * Gets the capabilities of the media type that currently flows through @pad
2591 * This function can be used on both src and sinkpads. Note that srcpads are
2592 * always negotiated before sinkpads so it is possible that the negotiated caps
2593 * on the srcpad do not match the negotiated caps of the peer.
2595 * Returns: the negotiated #GstCaps of the pad link. Unref the caps when
2596 * you no longer need it. This function returns NULL when the @pad has no
2597 * peer or is not negotiated yet.
2602 gst_pad_get_negotiated_caps (GstPad * pad)
2607 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2609 GST_OBJECT_LOCK (pad);
2611 if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
2614 GST_CAT_DEBUG_OBJECT (GST_CAT_PROPERTIES, pad, "getting negotiated caps");
2616 caps = GST_PAD_CAPS (pad);
2618 gst_caps_ref (caps);
2619 GST_OBJECT_UNLOCK (pad);
2621 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "negotiated caps %" GST_PTR_FORMAT,
2628 GST_CAT_DEBUG_OBJECT (GST_CAT_PROPERTIES, pad, "no peer");
2629 GST_OBJECT_UNLOCK (pad);
2635 /* calls the buffer_alloc function on the given pad */
2636 static GstFlowReturn
2637 gst_pad_buffer_alloc_unchecked (GstPad * pad, guint64 offset, gint size,
2638 GstCaps * caps, GstBuffer ** buf)
2641 GstPadBufferAllocFunction bufferallocfunc;
2643 GST_OBJECT_LOCK (pad);
2644 /* when the pad is flushing we cannot give a buffer */
2645 if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad)))
2648 bufferallocfunc = pad->bufferallocfunc;
2650 if (offset == GST_BUFFER_OFFSET_NONE) {
2651 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
2652 "calling bufferallocfunc &%s (@%p) for size %d offset NONE",
2653 GST_DEBUG_FUNCPTR_NAME (bufferallocfunc), bufferallocfunc, size);
2655 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
2656 "calling bufferallocfunc &%s (@%p) of for size %d offset %"
2657 G_GUINT64_FORMAT, GST_DEBUG_FUNCPTR_NAME (bufferallocfunc),
2658 bufferallocfunc, size, offset);
2660 GST_OBJECT_UNLOCK (pad);
2662 /* G_LIKELY for now since most elements don't implement a buffer alloc
2663 * function and there is no default alloc proxy function as this is usually
2665 if (G_LIKELY (bufferallocfunc == NULL))
2668 ret = bufferallocfunc (pad, offset, size, caps, buf);
2669 if (G_UNLIKELY (ret != GST_FLOW_OK))
2671 /* no error, but NULL buffer means fallback to the default */
2672 if (G_UNLIKELY (*buf == NULL))
2675 /* If the buffer alloc function didn't set up the caps like it should,
2677 if (G_UNLIKELY (caps && (GST_BUFFER_CAPS (*buf) == NULL))) {
2678 GST_WARNING_OBJECT (pad,
2679 "Buffer allocation function did not set caps. Setting");
2680 gst_buffer_set_caps (*buf, caps);
2686 /* pad was flushing */
2687 GST_OBJECT_UNLOCK (pad);
2688 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "pad was flushing");
2689 return GST_FLOW_WRONG_STATE;
2693 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
2694 "alloc function returned error (%d) %s", ret, gst_flow_get_name (ret));
2699 /* fallback case, allocate a buffer of our own, add pad caps. */
2700 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "fallback buffer alloc");
2702 if ((*buf = gst_buffer_try_new_and_alloc (size))) {
2703 GST_BUFFER_OFFSET (*buf) = offset;
2704 gst_buffer_set_caps (*buf, caps);
2707 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
2708 "out of memory allocating %d bytes", size);
2709 return GST_FLOW_ERROR;
2714 static GstFlowReturn
2715 gst_pad_alloc_buffer_full (GstPad * pad, guint64 offset, gint size,
2716 GstCaps * caps, GstBuffer ** buf, gboolean setcaps)
2720 gboolean caps_changed;
2722 g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
2723 g_return_val_if_fail (GST_PAD_IS_SRC (pad), GST_FLOW_ERROR);
2724 g_return_val_if_fail (buf != NULL, GST_FLOW_ERROR);
2726 GST_DEBUG_OBJECT (pad, "offset %" G_GUINT64_FORMAT ", size %d", offset, size);
2728 GST_OBJECT_LOCK (pad);
2729 while (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad)))
2730 if ((ret = handle_pad_block (pad)) != GST_FLOW_OK)
2733 if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
2736 gst_object_ref (peer);
2737 GST_OBJECT_UNLOCK (pad);
2739 ret = gst_pad_buffer_alloc_unchecked (peer, offset, size, caps, buf);
2740 gst_object_unref (peer);
2742 if (G_UNLIKELY (ret != GST_FLOW_OK))
2745 /* FIXME, move capnego this into a base class? */
2746 caps = GST_BUFFER_CAPS (*buf);
2748 /* Lock for checking caps, pretty pointless as the _pad_push() function might
2749 * change it concurrently, one of the problems with automatic caps setting in
2750 * pad_alloc_and_set_caps. Worst case, if does a check too much, but only
2751 * when there is heavy renegotiation going on in both directions. */
2752 GST_OBJECT_LOCK (pad);
2753 caps_changed = caps && caps != GST_PAD_CAPS (pad);
2754 GST_OBJECT_UNLOCK (pad);
2756 /* we got a new datatype on the pad, see if it can handle it */
2757 if (G_UNLIKELY (caps_changed)) {
2758 GST_DEBUG_OBJECT (pad,
2759 "caps changed from %" GST_PTR_FORMAT " to %p %" GST_PTR_FORMAT,
2760 GST_PAD_CAPS (pad), caps, caps);
2761 if (G_UNLIKELY (!gst_pad_configure_src (pad, caps, setcaps)))
2762 goto not_negotiated;
2768 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "pad block stopped by flush");
2769 GST_OBJECT_UNLOCK (pad);
2774 /* pad has no peer */
2775 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
2776 "called bufferallocfunc but had no peer");
2777 GST_OBJECT_UNLOCK (pad);
2778 return GST_FLOW_NOT_LINKED;
2782 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
2783 "alloc function returned error %s", gst_flow_get_name (ret));
2788 gst_buffer_unref (*buf);
2790 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
2791 "alloc function returned unacceptable buffer");
2792 return GST_FLOW_NOT_NEGOTIATED;
2797 * gst_pad_alloc_buffer:
2798 * @pad: a source #GstPad
2799 * @offset: the offset of the new buffer in the stream
2800 * @size: the size of the new buffer
2801 * @caps: the caps of the new buffer
2802 * @buf: a newly allocated buffer
2804 * Allocates a new, empty buffer optimized to push to pad @pad. This
2805 * function only works if @pad is a source pad and has a peer.
2807 * A new, empty #GstBuffer will be put in the @buf argument.
2808 * You need to check the caps of the buffer after performing this
2809 * function and renegotiate to the format if needed.
2811 * Returns: a result code indicating success of the operation. Any
2812 * result code other than #GST_FLOW_OK is an error and @buf should
2814 * An error can occur if the pad is not connected or when the downstream
2815 * peer elements cannot provide an acceptable buffer.
2820 gst_pad_alloc_buffer (GstPad * pad, guint64 offset, gint size, GstCaps * caps,
2823 return gst_pad_alloc_buffer_full (pad, offset, size, caps, buf, FALSE);
2827 * gst_pad_alloc_buffer_and_set_caps:
2828 * @pad: a source #GstPad
2829 * @offset: the offset of the new buffer in the stream
2830 * @size: the size of the new buffer
2831 * @caps: the caps of the new buffer
2832 * @buf: a newly allocated buffer
2834 * In addition to the function gst_pad_alloc_buffer(), this function
2835 * automatically calls gst_pad_set_caps() when the caps of the
2836 * newly allocated buffer are different from the @pad caps.
2838 * Returns: a result code indicating success of the operation. Any
2839 * result code other than #GST_FLOW_OK is an error and @buf should
2841 * An error can occur if the pad is not connected or when the downstream
2842 * peer elements cannot provide an acceptable buffer.
2847 gst_pad_alloc_buffer_and_set_caps (GstPad * pad, guint64 offset, gint size,
2848 GstCaps * caps, GstBuffer ** buf)
2850 return gst_pad_alloc_buffer_full (pad, offset, size, caps, buf, TRUE);
2854 * gst_pad_get_internal_links_default:
2855 * @pad: the #GstPad to get the internal links of.
2857 * Gets a list of pads to which the given pad is linked to
2858 * inside of the parent element.
2859 * This is the default handler, and thus returns a list of all of the
2860 * pads inside the parent element with opposite direction.
2861 * The caller must free this list after use.
2863 * Returns: a newly allocated #GList of pads, or NULL if the pad has no parent.
2868 gst_pad_get_internal_links_default (GstPad * pad)
2873 GstPadDirection direction;
2875 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2877 direction = pad->direction;
2879 parent = GST_PAD_PARENT (pad);
2883 parent_pads = parent->pads;
2885 while (parent_pads) {
2886 GstPad *parent_pad = GST_PAD_CAST (parent_pads->data);
2888 if (parent_pad->direction != direction) {
2889 GST_DEBUG_OBJECT (pad, "adding pad %s:%s",
2890 GST_DEBUG_PAD_NAME (parent_pad));
2891 res = g_list_prepend (res, parent_pad);
2893 parent_pads = g_list_next (parent_pads);
2899 GST_DEBUG_OBJECT (pad, "no parent");
2905 * gst_pad_get_internal_links:
2906 * @pad: the #GstPad to get the internal links of.
2908 * Gets a list of pads to which the given pad is linked to
2909 * inside of the parent element.
2910 * The caller must free this list after use.
2912 * Returns: a newly allocated #GList of pads.
2917 gst_pad_get_internal_links (GstPad * pad)
2921 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2923 if (GST_PAD_INTLINKFUNC (pad))
2924 res = GST_PAD_INTLINKFUNC (pad) (pad);
2931 gst_pad_event_default_dispatch (GstPad * pad, GstEvent * event)
2936 GST_INFO_OBJECT (pad, "Sending event %p (%s) to all internally linked pads",
2937 event, GST_EVENT_TYPE_NAME (event));
2939 result = (GST_PAD_DIRECTION (pad) == GST_PAD_SINK);
2941 orig = pads = gst_pad_get_internal_links (pad);
2944 GstPad *eventpad = GST_PAD_CAST (pads->data);
2946 pads = g_list_next (pads);
2948 if (GST_PAD_DIRECTION (eventpad) == GST_PAD_SRC) {
2949 /* for each pad we send to, we should ref the event; it's up
2950 * to downstream to unref again when handled. */
2951 GST_LOG_OBJECT (pad, "Reffing and sending event %p (%s) to %s:%s",
2952 event, GST_EVENT_TYPE_NAME (event), GST_DEBUG_PAD_NAME (eventpad));
2953 gst_event_ref (event);
2954 gst_pad_push_event (eventpad, event);
2956 /* we only send the event on one pad, multi-sinkpad elements
2957 * should implement a handler */
2958 GST_LOG_OBJECT (pad, "sending event %p (%s) to one sink pad %s:%s",
2959 event, GST_EVENT_TYPE_NAME (event), GST_DEBUG_PAD_NAME (eventpad));
2960 result = gst_pad_push_event (eventpad, event);
2964 /* we handled the incoming event so we unref once */
2965 GST_LOG_OBJECT (pad, "handled event %p, unreffing", event);
2966 gst_event_unref (event);
2975 * gst_pad_event_default:
2976 * @pad: a #GstPad to call the default event handler on.
2977 * @event: the #GstEvent to handle.
2979 * Invokes the default event handler for the given pad. End-of-stream and
2980 * discontinuity events are handled specially, and then the event is sent to all
2981 * pads internally linked to @pad. Note that if there are many possible sink
2982 * pads that are internally linked to @pad, only one will be sent an event.
2983 * Multi-sinkpad elements should implement custom event handlers.
2985 * Returns: TRUE if the event was sent succesfully.
2988 gst_pad_event_default (GstPad * pad, GstEvent * event)
2990 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2991 g_return_val_if_fail (event != NULL, FALSE);
2993 switch (GST_EVENT_TYPE (event)) {
2996 GST_DEBUG_OBJECT (pad, "pausing task because of eos");
2997 gst_pad_pause_task (pad);
3004 return gst_pad_event_default_dispatch (pad, event);
3008 * gst_pad_dispatcher:
3009 * @pad: a #GstPad to dispatch.
3010 * @dispatch: the #GstDispatcherFunction to call.
3011 * @data: gpointer user data passed to the dispatcher function.
3013 * Invokes the given dispatcher function on each respective peer of
3014 * all pads that are internally linked to the given pad.
3015 * The GstPadDispatcherFunction should return TRUE when no further pads
3016 * need to be processed.
3018 * Returns: TRUE if one of the dispatcher functions returned TRUE.
3021 gst_pad_dispatcher (GstPad * pad, GstPadDispatcherFunction dispatch,
3024 gboolean res = FALSE;
3025 GList *int_pads, *orig;
3027 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
3028 g_return_val_if_fail (dispatch != NULL, FALSE);
3030 orig = int_pads = gst_pad_get_internal_links (pad);
3033 GstPad *int_pad = GST_PAD_CAST (int_pads->data);
3034 GstPad *int_peer = gst_pad_get_peer (int_pad);
3037 GST_DEBUG_OBJECT (int_pad, "dispatching to peer %s:%s",
3038 GST_DEBUG_PAD_NAME (int_peer));
3039 res = dispatch (int_peer, data);
3040 gst_object_unref (int_peer);
3044 GST_DEBUG_OBJECT (int_pad, "no peer");
3046 int_pads = g_list_next (int_pads);
3049 GST_DEBUG_OBJECT (pad, "done, result %d", res);
3056 * @pad: a #GstPad to invoke the default query on.
3057 * @query: the #GstQuery to perform.
3059 * Dispatches a query to a pad. The query should have been allocated by the
3060 * caller via one of the type-specific allocation functions in gstquery.h. The
3061 * element is responsible for filling the query with an appropriate response,
3062 * which should then be parsed with a type-specific query parsing function.
3064 * Again, the caller is responsible for both the allocation and deallocation of
3065 * the query structure.
3067 * Returns: TRUE if the query could be performed.
3070 gst_pad_query (GstPad * pad, GstQuery * query)
3072 GstPadQueryFunction func;
3074 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
3075 g_return_val_if_fail (GST_IS_QUERY (query), FALSE);
3077 GST_DEBUG_OBJECT (pad, "sending query %p", query);
3079 if ((func = GST_PAD_QUERYFUNC (pad)) == NULL)
3082 return func (pad, query);
3086 GST_DEBUG_OBJECT (pad, "had no query function");
3092 * gst_pad_peer_query:
3093 * @pad: a #GstPad to invoke the peer query on.
3094 * @query: the #GstQuery to perform.
3096 * Performs gst_pad_query() on the peer of @pad.
3098 * The caller is responsible for both the allocation and deallocation of
3099 * the query structure.
3101 * Returns: TRUE if the query could be performed. This function returns %FALSE
3102 * if @pad has no peer.
3107 gst_pad_peer_query (GstPad * pad, GstQuery * query)
3112 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
3113 g_return_val_if_fail (GST_IS_QUERY (query), FALSE);
3115 GST_OBJECT_LOCK (pad);
3117 GST_DEBUG_OBJECT (pad, "peer query");
3119 peerpad = GST_PAD_PEER (pad);
3120 if (G_UNLIKELY (peerpad == NULL))
3123 gst_object_ref (peerpad);
3124 GST_OBJECT_UNLOCK (pad);
3126 result = gst_pad_query (peerpad, query);
3128 gst_object_unref (peerpad);
3135 GST_WARNING_OBJECT (pad, "pad has no peer");
3136 GST_OBJECT_UNLOCK (pad);
3142 * gst_pad_query_default:
3143 * @pad: a #GstPad to call the default query handler on.
3144 * @query: the #GstQuery to handle.
3146 * Invokes the default query handler for the given pad.
3147 * The query is sent to all pads internally linked to @pad. Note that
3148 * if there are many possible sink pads that are internally linked to
3149 * @pad, only one will be sent the query.
3150 * Multi-sinkpad elements should implement custom query handlers.
3152 * Returns: TRUE if the query was performed succesfully.
3155 gst_pad_query_default (GstPad * pad, GstQuery * query)
3157 switch (GST_QUERY_TYPE (query)) {
3158 case GST_QUERY_POSITION:
3159 case GST_QUERY_SEEKING:
3160 case GST_QUERY_FORMATS:
3161 case GST_QUERY_LATENCY:
3162 case GST_QUERY_JITTER:
3163 case GST_QUERY_RATE:
3164 case GST_QUERY_CONVERT:
3166 return gst_pad_dispatcher
3167 (pad, (GstPadDispatcherFunction) gst_pad_query, query);
3171 #ifndef GST_DISABLE_LOADSAVE
3172 /* FIXME: why isn't this on a GstElement ? */
3174 * gst_pad_load_and_link:
3175 * @self: an #xmlNodePtr to read the description from.
3176 * @parent: the #GstObject element that owns the pad.
3178 * Reads the pad definition from the XML node and links the given pad
3179 * in the element to a pad of an element up in the hierarchy.
3182 gst_pad_load_and_link (xmlNodePtr self, GstObject * parent)
3184 xmlNodePtr field = self->xmlChildrenNode;
3185 GstPad *pad = NULL, *targetpad;
3189 GstObject *grandparent;
3193 if (!strcmp ((char *) field->name, "name")) {
3194 name = (gchar *) xmlNodeGetContent (field);
3195 pad = gst_element_get_pad (GST_ELEMENT (parent), name);
3197 } else if (!strcmp ((char *) field->name, "peer")) {
3198 peer = (gchar *) xmlNodeGetContent (field);
3200 field = field->next;
3202 g_return_if_fail (pad != NULL);
3207 split = g_strsplit (peer, ".", 2);
3209 if (split[0] == NULL || split[1] == NULL) {
3210 GST_CAT_DEBUG_OBJECT (GST_CAT_XML, pad,
3211 "Could not parse peer '%s', leaving unlinked", peer);
3218 g_return_if_fail (split[0] != NULL);
3219 g_return_if_fail (split[1] != NULL);
3221 grandparent = gst_object_get_parent (parent);
3223 if (grandparent && GST_IS_BIN (grandparent)) {
3224 target = gst_bin_get_by_name_recurse_up (GST_BIN (grandparent), split[0]);
3231 targetpad = gst_element_get_pad (target, split[1]);
3233 if (targetpad == NULL)
3236 gst_pad_link (pad, targetpad);
3243 * gst_pad_save_thyself:
3244 * @pad: a #GstPad to save.
3245 * @parent: the parent #xmlNodePtr to save the description in.
3247 * Saves the pad into an xml representation.
3249 * Returns: the #xmlNodePtr representation of the pad.
3252 gst_pad_save_thyself (GstObject * object, xmlNodePtr parent)
3257 g_return_val_if_fail (GST_IS_PAD (object), NULL);
3259 pad = GST_PAD (object);
3261 xmlNewChild (parent, NULL, (xmlChar *) "name",
3262 (xmlChar *) GST_PAD_NAME (pad));
3264 if (GST_PAD_IS_SRC (pad)) {
3265 xmlNewChild (parent, NULL, (xmlChar *) "direction", (xmlChar *) "source");
3266 } else if (GST_PAD_IS_SINK (pad)) {
3267 xmlNewChild (parent, NULL, (xmlChar *) "direction", (xmlChar *) "sink");
3269 xmlNewChild (parent, NULL, (xmlChar *) "direction", (xmlChar *) "unknown");
3272 if (GST_PAD_PEER (pad) != NULL) {
3275 peer = GST_PAD_PEER (pad);
3276 /* first check to see if the peer's parent's parent is the same */
3277 /* we just save it off */
3278 content = g_strdup_printf ("%s.%s",
3279 GST_OBJECT_NAME (GST_PAD_PARENT (peer)), GST_PAD_NAME (peer));
3280 xmlNewChild (parent, NULL, (xmlChar *) "peer", (xmlChar *) content);
3283 xmlNewChild (parent, NULL, (xmlChar *) "peer", NULL);
3290 * gst_ghost_pad_save_thyself:
3291 * @pad: a ghost #GstPad to save.
3292 * @parent: the parent #xmlNodePtr to save the description in.
3294 * Saves the ghost pad into an xml representation.
3296 * Returns: the #xmlNodePtr representation of the pad.
3299 gst_ghost_pad_save_thyself (GstPad * pad, xmlNodePtr parent)
3303 g_return_val_if_fail (GST_IS_GHOST_PAD (pad), NULL);
3305 self = xmlNewChild (parent, NULL, (xmlChar *) "ghostpad", NULL);
3306 xmlNewChild (self, NULL, (xmlChar *) "name", (xmlChar *) GST_PAD_NAME (pad));
3307 xmlNewChild (self, NULL, (xmlChar *) "parent",
3308 (xmlChar *) GST_OBJECT_NAME (GST_PAD_PARENT (pad)));
3310 /* FIXME FIXME FIXME! */
3315 #endif /* GST_DISABLE_LOADSAVE */
3318 * should be called with pad OBJECT_LOCK and STREAM_LOCK held.
3319 * GST_PAD_IS_BLOCKED (pad) == TRUE when this function is
3322 * This function performs the pad blocking when an event, buffer push
3323 * or buffer_alloc is performed on a _SRC_ pad. It blocks the
3324 * streaming thread after informing the pad has been blocked.
3326 * An application can with this method wait and block any streaming
3327 * thread and perform operations such as seeking or linking.
3329 * Two methods are available for notifying the application of the
3331 * - the callback method, which happens in the STREAMING thread with
3332 * the STREAM_LOCK held. With this method, the most useful way of
3333 * dealing with the callback is to post a message to the main thread
3334 * where the pad block can then be handled outside of the streaming
3335 * thread. With the last method one can perform all operations such
3336 * as doing a state change, linking, unblocking, seeking etc on the
3338 * - the GCond signal method, which makes any thread unblock when
3339 * the pad block happens.
3341 * During the actual blocking state, the GST_PAD_BLOCKING flag is set.
3342 * The GST_PAD_BLOCKING flag is unset when the pad was unblocked.
3346 static GstFlowReturn
3347 handle_pad_block (GstPad * pad)
3349 GstPadBlockCallback callback;
3351 GstFlowReturn ret = GST_FLOW_OK;
3353 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "signal block taken");
3355 /* flushing, don't bother trying to block and return WRONG_STATE
3357 if (GST_PAD_IS_FLUSHING (pad))
3358 goto flushingnonref;
3360 /* we grab an extra ref for the callbacks, this is probably not
3361 * needed (callback code does not have a ref and cannot unref). I
3362 * think this was done to make it possible to unref the element in
3363 * the callback, which is in the end totally impossible as it
3364 * requires grabbing the STREAM_LOCK and OBJECT_LOCK which are
3365 * all taken when calling this function. */
3366 gst_object_ref (pad);
3368 /* we either have a callback installed to notify the block or
3369 * some other thread is doing a GCond wait. */
3370 callback = pad->block_callback;
3372 /* there is a callback installed, call it. We release the
3373 * lock so that the callback can do something usefull with the
3375 user_data = pad->block_data;
3376 GST_OBJECT_UNLOCK (pad);
3377 callback (pad, TRUE, user_data);
3378 GST_OBJECT_LOCK (pad);
3380 /* we released the lock, recheck flushing */
3381 if (GST_PAD_IS_FLUSHING (pad))
3384 /* no callback, signal the thread that is doing a GCond wait
3386 GST_PAD_BLOCK_BROADCAST (pad);
3389 /* OBJECT_LOCK could have been released when we did the callback, which
3390 * then could have made the pad unblock so we need to check the blocking
3391 * condition again. */
3392 while (GST_PAD_IS_BLOCKED (pad)) {
3393 /* now we block the streaming thread. It can be unlocked when we
3394 * deactivate the pad (which will also set the FLUSHING flag) or
3395 * when the pad is unblocked. A flushing event will also unblock
3396 * the pad after setting the FLUSHING flag. */
3397 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3398 "Waiting to be unblocked or set flushing");
3399 GST_OBJECT_FLAG_SET (pad, GST_PAD_BLOCKING);
3400 GST_PAD_BLOCK_WAIT (pad);
3401 GST_OBJECT_FLAG_UNSET (pad, GST_PAD_BLOCKING);
3403 /* see if we got unblocked by a flush or not */
3404 if (GST_PAD_IS_FLUSHING (pad))
3408 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "got unblocked");
3410 /* when we get here, the pad is unblocked again and we perform
3411 * the needed unblock code. */
3412 callback = pad->block_callback;
3414 /* we need to call the callback */
3415 user_data = pad->block_data;
3416 GST_OBJECT_UNLOCK (pad);
3417 callback (pad, FALSE, user_data);
3418 GST_OBJECT_LOCK (pad);
3420 /* we need to signal the thread waiting on the GCond */
3421 GST_PAD_BLOCK_BROADCAST (pad);
3424 gst_object_unref (pad);
3430 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "pad was flushing");
3431 return GST_FLOW_WRONG_STATE;
3435 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "pad became flushing");
3436 gst_object_unref (pad);
3437 return GST_FLOW_WRONG_STATE;
3441 /**********************************************************************
3442 * Data passing functions
3446 gst_pad_emit_have_data_signal (GstPad * pad, GstMiniObject * obj)
3449 GValue args[2] = { {0}, {0} };
3454 g_value_init (&ret, G_TYPE_BOOLEAN);
3455 g_value_set_boolean (&ret, TRUE);
3456 g_value_init (&args[0], GST_TYPE_PAD);
3457 g_value_set_object (&args[0], pad);
3458 g_value_init (&args[1], GST_TYPE_MINI_OBJECT);
3459 gst_value_set_mini_object (&args[1], obj);
3461 if (GST_IS_EVENT (obj))
3462 detail = event_quark;
3464 detail = buffer_quark;
3467 g_signal_emitv (args, gst_pad_signals[PAD_HAVE_DATA], detail, &ret);
3468 res = g_value_get_boolean (&ret);
3471 g_value_unset (&ret);
3472 g_value_unset (&args[0]);
3473 g_value_unset (&args[1]);
3478 /* this is the chain function that does not perform the additional argument
3479 * checking for that little extra speed.
3481 static inline GstFlowReturn
3482 gst_pad_chain_unchecked (GstPad * pad, GstBuffer * buffer)
3485 gboolean caps_changed;
3486 GstPadChainFunction chainfunc;
3488 gboolean emit_signal;
3490 GST_PAD_STREAM_LOCK (pad);
3492 GST_OBJECT_LOCK (pad);
3493 if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad)))
3496 caps = GST_BUFFER_CAPS (buffer);
3497 caps_changed = caps && caps != GST_PAD_CAPS (pad);
3499 emit_signal = GST_PAD_DO_BUFFER_SIGNALS (pad) > 0;
3500 GST_OBJECT_UNLOCK (pad);
3502 /* see if the signal should be emited, we emit before caps nego as
3503 * we might drop the buffer and do capsnego for nothing. */
3504 if (G_UNLIKELY (emit_signal)) {
3505 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (buffer)))
3509 /* we got a new datatype on the pad, see if it can handle it */
3510 if (G_UNLIKELY (caps_changed)) {
3511 GST_DEBUG_OBJECT (pad, "caps changed to %p %" GST_PTR_FORMAT, caps, caps);
3512 if (G_UNLIKELY (!gst_pad_configure_sink (pad, caps)))
3513 goto not_negotiated;
3516 /* NOTE: we read the chainfunc unlocked.
3517 * we cannot hold the lock for the pad so we might send
3518 * the data to the wrong function. This is not really a
3519 * problem since functions are assigned at creation time
3520 * and don't change that often... */
3521 if (G_UNLIKELY ((chainfunc = GST_PAD_CHAINFUNC (pad)) == NULL))
3524 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3525 "calling chainfunction &%s", GST_DEBUG_FUNCPTR_NAME (chainfunc));
3527 ret = chainfunc (pad, buffer);
3529 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3530 "called chainfunction &%s, returned %s",
3531 GST_DEBUG_FUNCPTR_NAME (chainfunc), gst_flow_get_name (ret));
3533 GST_PAD_STREAM_UNLOCK (pad);
3540 gst_buffer_unref (buffer);
3541 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3542 "pushing, but pad was flushing");
3543 GST_OBJECT_UNLOCK (pad);
3544 GST_PAD_STREAM_UNLOCK (pad);
3545 return GST_FLOW_WRONG_STATE;
3549 gst_buffer_unref (buffer);
3550 GST_DEBUG_OBJECT (pad, "Dropping buffer due to FALSE probe return");
3551 GST_PAD_STREAM_UNLOCK (pad);
3556 gst_buffer_unref (buffer);
3557 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3558 "pushing buffer but pad did not accept");
3559 GST_PAD_STREAM_UNLOCK (pad);
3560 return GST_FLOW_NOT_NEGOTIATED;
3564 gst_buffer_unref (buffer);
3565 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3566 "pushing, but not chainhandler");
3567 GST_ELEMENT_ERROR (GST_PAD_PARENT (pad), CORE, PAD, (NULL),
3568 ("push on pad %s:%s but it has no chainfunction",
3569 GST_DEBUG_PAD_NAME (pad)));
3570 GST_PAD_STREAM_UNLOCK (pad);
3571 return GST_FLOW_NOT_SUPPORTED;
3577 * @pad: a sink #GstPad, returns GST_FLOW_ERROR if not.
3578 * @buffer: the #GstBuffer to send, return GST_FLOW_ERROR if not.
3580 * Chain a buffer to @pad.
3582 * The function returns #GST_FLOW_WRONG_STATE if the pad was flushing.
3584 * If the caps on @buffer are different from the current caps on @pad, this
3585 * function will call any setcaps function (see gst_pad_set_setcaps_function())
3586 * installed on @pad. If the new caps are not acceptable for @pad, this
3587 * function returns #GST_FLOW_NOT_NEGOTIATED.
3589 * The function proceeds calling the chain function installed on @pad (see
3590 * gst_pad_set_chain_function()) and the return value of that function is
3591 * returned to the caller. #GST_FLOW_NOT_SUPPORTED is returned if @pad has no
3594 * In all cases, success or failure, the caller loses its reference to @buffer
3595 * after calling this function.
3597 * Returns: a #GstFlowReturn from the pad.
3602 gst_pad_chain (GstPad * pad, GstBuffer * buffer)
3604 g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
3605 g_return_val_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SINK,
3607 g_return_val_if_fail (GST_IS_BUFFER (buffer), GST_FLOW_ERROR);
3609 return gst_pad_chain_unchecked (pad, buffer);
3614 * @pad: a source #GstPad, returns #GST_FLOW_ERROR if not.
3615 * @buffer: the #GstBuffer to push returns GST_FLOW_ERROR if not.
3617 * Pushes a buffer to the peer of @pad.
3619 * This function will call an installed pad block before triggering any
3620 * installed pad probes.
3622 * If the caps on @buffer are different from the currently configured caps on
3623 * @pad, this function will call any installed setcaps function on @pad (see
3624 * gst_pad_set_setcaps_function()). In case of failure to renegotiate the new
3625 * format, this function returns #GST_FLOW_NOT_NEGOTIATED.
3627 * The function proceeds calling gst_pad_chain() on the peer pad and returns
3628 * the value from that function. If @pad has no peer, #GST_FLOW_NOT_LINKED will
3631 * In all cases, success or failure, the caller loses its reference to @buffer
3632 * after calling this function.
3634 * Returns: a #GstFlowReturn from the peer pad.
3639 gst_pad_push (GstPad * pad, GstBuffer * buffer)
3645 gboolean caps_changed;
3647 g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
3648 g_return_val_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SRC, GST_FLOW_ERROR);
3649 g_return_val_if_fail (GST_IS_BUFFER (buffer), GST_FLOW_ERROR);
3651 GST_OBJECT_LOCK (pad);
3653 /* FIXME: this check can go away; pad_set_blocked could be implemented with
3654 * probes completely or probes with an extended pad block. */
3655 while (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad)))
3656 if ((ret = handle_pad_block (pad)) != GST_FLOW_OK)
3659 /* we emit signals on the pad arg, the peer will have a chance to
3660 * emit in the _chain() function */
3661 if (G_UNLIKELY (GST_PAD_DO_BUFFER_SIGNALS (pad) > 0)) {
3662 /* unlock before emitting */
3663 GST_OBJECT_UNLOCK (pad);
3665 /* if the signal handler returned FALSE, it means we should just drop the
3667 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (buffer)))
3670 GST_OBJECT_LOCK (pad);
3673 if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
3676 /* take ref to peer pad before releasing the lock */
3677 gst_object_ref (peer);
3679 /* Before pushing the buffer to the peer pad, ensure that caps
3680 * are set on this pad */
3681 caps = GST_BUFFER_CAPS (buffer);
3682 caps_changed = caps && caps != GST_PAD_CAPS (pad);
3684 GST_OBJECT_UNLOCK (pad);
3686 /* we got a new datatype from the pad, it had better handle it */
3687 if (G_UNLIKELY (caps_changed)) {
3688 GST_DEBUG_OBJECT (pad,
3689 "caps changed from %" GST_PTR_FORMAT " to %p %" GST_PTR_FORMAT,
3690 GST_PAD_CAPS (pad), caps, caps);
3691 if (G_UNLIKELY (!gst_pad_configure_src (pad, caps, TRUE)))
3692 goto not_negotiated;
3695 ret = gst_pad_chain_unchecked (peer, buffer);
3697 gst_object_unref (peer);
3701 /* ERROR recovery here */
3704 gst_buffer_unref (buffer);
3705 GST_DEBUG_OBJECT (pad, "pad block stopped by flush");
3706 GST_OBJECT_UNLOCK (pad);
3711 gst_buffer_unref (buffer);
3712 GST_DEBUG_OBJECT (pad, "Dropping buffer due to FALSE probe return");
3717 gst_buffer_unref (buffer);
3718 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3719 "pushing, but it was not linked");
3720 GST_OBJECT_UNLOCK (pad);
3721 return GST_FLOW_NOT_LINKED;
3725 gst_buffer_unref (buffer);
3726 gst_object_unref (peer);
3727 GST_CAT_DEBUG_OBJECT (GST_CAT_SCHEDULING, pad,
3728 "element pushed buffer then refused to accept the caps");
3729 return GST_FLOW_NOT_NEGOTIATED;
3734 * gst_pad_check_pull_range:
3735 * @pad: a sink #GstPad.
3737 * Checks if a gst_pad_pull_range() can be performed on the peer
3738 * source pad. This function is used by plugins that want to check
3739 * if they can use random access on the peer source pad.
3741 * The peer sourcepad can implement a custom #GstPadCheckGetRangeFunction
3742 * if it needs to perform some logic to determine if pull_range is
3745 * Returns: a gboolean with the result.
3750 gst_pad_check_pull_range (GstPad * pad)
3754 GstPadCheckGetRangeFunction checkgetrangefunc;
3756 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
3758 GST_OBJECT_LOCK (pad);
3759 if (GST_PAD_DIRECTION (pad) != GST_PAD_SINK)
3760 goto wrong_direction;
3762 if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
3765 gst_object_ref (peer);
3766 GST_OBJECT_UNLOCK (pad);
3768 /* see note in above function */
3769 if (G_LIKELY ((checkgetrangefunc = peer->checkgetrangefunc) == NULL)) {
3770 /* FIXME, kindoff ghetto */
3771 ret = GST_PAD_GETRANGEFUNC (peer) != NULL;
3772 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3773 "no checkgetrangefunc, assuming %d", ret);
3775 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3776 "calling checkgetrangefunc %s of peer pad %s:%s",
3777 GST_DEBUG_FUNCPTR_NAME (checkgetrangefunc), GST_DEBUG_PAD_NAME (peer));
3779 ret = checkgetrangefunc (peer);
3782 gst_object_unref (peer);
3786 /* ERROR recovery here */
3789 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3790 "checking pull range, but pad must be a sinkpad");
3791 GST_OBJECT_UNLOCK (pad);
3796 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3797 "checking pull range, but it was not linked");
3798 GST_OBJECT_UNLOCK (pad);
3804 * gst_pad_get_range:
3805 * @pad: a src #GstPad, returns #GST_FLOW_ERROR if not.
3806 * @offset: The start offset of the buffer
3807 * @size: The length of the buffer
3808 * @buffer: a pointer to hold the #GstBuffer, returns #GST_FLOW_ERROR if %NULL.
3810 * When @pad is flushing this function returns #GST_FLOW_WRONG_STATE
3813 * Calls the getrange function of @pad, see #GstPadGetRangeFunction for a
3814 * description of a getrange function. If @pad has no getrange function
3815 * installed (see gst_pad_set_getrange_function()) this function returns
3816 * #GST_FLOW_NOT_SUPPORTED.
3818 * @buffer's caps must either be unset or the same as what is already
3819 * configured on @pad. Renegotiation within a running pull-mode pipeline is not
3822 * This is a lowlevel function. Usualy gst_pad_pull_range() is used.
3824 * Returns: a #GstFlowReturn from the pad.
3829 gst_pad_get_range (GstPad * pad, guint64 offset, guint size,
3830 GstBuffer ** buffer)
3833 GstPadGetRangeFunction getrangefunc;
3834 gboolean emit_signal;
3836 g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
3837 g_return_val_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SRC, GST_FLOW_ERROR);
3838 g_return_val_if_fail (buffer != NULL, GST_FLOW_ERROR);
3840 GST_PAD_STREAM_LOCK (pad);
3842 GST_OBJECT_LOCK (pad);
3843 if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad)))
3846 emit_signal = GST_PAD_DO_BUFFER_SIGNALS (pad) > 0;
3847 GST_OBJECT_UNLOCK (pad);
3849 if (G_UNLIKELY ((getrangefunc = GST_PAD_GETRANGEFUNC (pad)) == NULL))
3852 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3853 "calling getrangefunc %s, offset %"
3854 G_GUINT64_FORMAT ", size %u",
3855 GST_DEBUG_FUNCPTR_NAME (getrangefunc), offset, size);
3857 ret = getrangefunc (pad, offset, size, buffer);
3859 /* can only fire the signal if we have a valid buffer */
3860 if (G_UNLIKELY (emit_signal) && (ret == GST_FLOW_OK)) {
3861 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (*buffer)))
3865 GST_PAD_STREAM_UNLOCK (pad);
3867 if (G_LIKELY (ret == GST_FLOW_OK)) {
3869 gboolean caps_changed;
3871 GST_OBJECT_LOCK (pad);
3872 /* Before pushing the buffer to the peer pad, ensure that caps
3873 * are set on this pad */
3874 caps = GST_BUFFER_CAPS (*buffer);
3875 caps_changed = caps && caps != GST_PAD_CAPS (pad);
3876 GST_OBJECT_UNLOCK (pad);
3878 /* we got a new datatype from the pad not supported in a running pull-mode
3880 if (G_UNLIKELY (caps_changed))
3881 goto not_negotiated;
3889 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3890 "pulling range, but pad was flushing");
3891 GST_OBJECT_UNLOCK (pad);
3892 GST_PAD_STREAM_UNLOCK (pad);
3893 return GST_FLOW_WRONG_STATE;
3897 GST_ELEMENT_ERROR (GST_PAD_PARENT (pad), CORE, PAD, (NULL),
3898 ("pullrange on pad %s:%s but it has no getrangefunction",
3899 GST_DEBUG_PAD_NAME (pad)));
3900 GST_PAD_STREAM_UNLOCK (pad);
3901 return GST_FLOW_NOT_SUPPORTED;
3905 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3906 "Dropping data after FALSE probe return");
3907 GST_PAD_STREAM_UNLOCK (pad);
3908 gst_buffer_unref (*buffer);
3910 return GST_FLOW_UNEXPECTED;
3914 /* ideally we want to use the commented-out code, but currently demuxers
3915 * and typefind do not follow part-negotiation.txt. When switching into
3916 * pull mode, typefind should probably return the found caps from
3917 * getcaps(), and demuxers should do the setcaps(). */
3920 gst_buffer_unref (*buffer);
3922 GST_CAT_WARNING_OBJECT (GST_CAT_SCHEDULING, pad,
3923 "getrange returned buffer of different caps");
3924 return GST_FLOW_NOT_NEGOTIATED;
3926 GST_CAT_DEBUG_OBJECT (GST_CAT_SCHEDULING, pad,
3927 "getrange returned buffer of different caps");
3934 * gst_pad_pull_range:
3935 * @pad: a sink #GstPad, returns GST_FLOW_ERROR if not.
3936 * @offset: The start offset of the buffer
3937 * @size: The length of the buffer
3938 * @buffer: a pointer to hold the #GstBuffer, returns GST_FLOW_ERROR if %NULL.
3940 * Pulls a @buffer from the peer pad.
3942 * This function will first trigger the pad block signal if it was
3945 * When @pad is not linked #GST_FLOW_NOT_LINKED is returned else this
3946 * function returns the result of gst_pad_get_range() on the peer pad.
3947 * See gst_pad_get_range() for a list of return values and for the
3948 * semantics of the arguments of this function.
3950 * @buffer's caps must either be unset or the same as what is already
3951 * configured on @pad. Renegotiation within a running pull-mode pipeline is not
3954 * Returns: a #GstFlowReturn from the peer pad.
3955 * When this function returns #GST_FLOW_OK, @buffer will contain a valid
3956 * #GstBuffer that should be freed with gst_buffer_unref() after usage.
3957 * @buffer may not be used or freed when any other return value than
3958 * #GST_FLOW_OK is returned.
3963 gst_pad_pull_range (GstPad * pad, guint64 offset, guint size,
3964 GstBuffer ** buffer)
3968 gboolean emit_signal;
3970 g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
3971 g_return_val_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SINK,
3973 g_return_val_if_fail (buffer != NULL, GST_FLOW_ERROR);
3975 GST_OBJECT_LOCK (pad);
3977 while (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad)))
3978 handle_pad_block (pad);
3980 if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
3983 /* signal emision for the pad, peer has chance to emit when
3984 * we call _get_range() */
3985 emit_signal = GST_PAD_DO_BUFFER_SIGNALS (pad) > 0;
3987 gst_object_ref (peer);
3988 GST_OBJECT_UNLOCK (pad);
3990 ret = gst_pad_get_range (peer, offset, size, buffer);
3992 gst_object_unref (peer);
3994 /* can only fire the signal if we have a valid buffer */
3995 if (G_UNLIKELY (emit_signal) && (ret == GST_FLOW_OK)) {
3996 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (*buffer)))
4000 if (G_LIKELY (ret == GST_FLOW_OK)) {
4002 gboolean caps_changed;
4004 GST_OBJECT_LOCK (pad);
4005 /* Before pushing the buffer to the peer pad, ensure that caps
4006 * are set on this pad */
4007 caps = GST_BUFFER_CAPS (*buffer);
4008 caps_changed = caps && caps != GST_PAD_CAPS (pad);
4009 GST_OBJECT_UNLOCK (pad);
4011 /* we got a new datatype on the pad, see if it can handle it */
4012 if (G_UNLIKELY (caps_changed))
4013 goto not_negotiated;
4018 /* ERROR recovery here */
4021 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
4022 "pulling range, but it was not linked");
4023 GST_OBJECT_UNLOCK (pad);
4024 return GST_FLOW_NOT_LINKED;
4028 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
4029 "Dropping data after FALSE probe return");
4030 gst_buffer_unref (*buffer);
4032 return GST_FLOW_UNEXPECTED;
4036 /* ideally we want to use the commented-out code, but currently demuxers
4037 * and typefind do not follow part-negotiation.txt. When switching into
4038 * pull mode, typefind should probably return the found caps from
4039 * getcaps(), and demuxers should do the setcaps(). */
4042 gst_buffer_unref (*buffer);
4044 GST_CAT_WARNING_OBJECT (GST_CAT_SCHEDULING, pad,
4045 "pullrange returned buffer of different caps");
4046 return GST_FLOW_NOT_NEGOTIATED;
4048 GST_CAT_DEBUG_OBJECT (GST_CAT_SCHEDULING, pad,
4049 "pullrange returned buffer of different caps");
4055 * gst_pad_push_event:
4056 * @pad: a #GstPad to push the event to.
4057 * @event: the #GstEvent to send to the pad.
4059 * Sends the event to the peer of the given pad. This function is
4060 * mainly used by elements to send events to their peer
4063 * This function takes owership of the provided event so you should
4064 * gst_event_ref() it if you want to reuse the event after this call.
4066 * Returns: TRUE if the event was handled.
4071 gst_pad_push_event (GstPad * pad, GstEvent * event)
4076 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
4077 g_return_val_if_fail (event != NULL, FALSE);
4078 g_return_val_if_fail (GST_IS_EVENT (event), FALSE);
4080 GST_LOG_OBJECT (pad, "event: %s", GST_EVENT_TYPE_NAME (event));
4082 GST_OBJECT_LOCK (pad);
4084 /* Two checks to be made:
4085 * . (un)set the FLUSHING flag for flushing events,
4086 * . handle pad blocking */
4087 switch (GST_EVENT_TYPE (event)) {
4088 case GST_EVENT_FLUSH_START:
4089 GST_PAD_SET_FLUSHING (pad);
4091 if (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad))) {
4092 /* flush start will have set the FLUSHING flag and will then
4093 * unlock all threads doing a GCond wait on the blocking pad. This
4094 * will typically unblock the STREAMING thread blocked on a pad. */
4095 GST_LOG_OBJECT (pad, "Pad is blocked, not forwarding flush-start, "
4096 "doing block signal.");
4097 GST_PAD_BLOCK_BROADCAST (pad);
4101 case GST_EVENT_FLUSH_STOP:
4102 GST_PAD_UNSET_FLUSHING (pad);
4104 /* if we are blocked, flush away the FLUSH_STOP event */
4105 if (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad))) {
4106 GST_LOG_OBJECT (pad, "Pad is blocked, not forwarding flush-stop");
4111 while (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad))) {
4112 /* block the event as long as the pad is blocked */
4113 if (handle_pad_block (pad) != GST_FLOW_OK)
4119 if (G_UNLIKELY (GST_PAD_DO_EVENT_SIGNALS (pad) > 0)) {
4120 GST_OBJECT_UNLOCK (pad);
4122 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (event)))
4125 GST_OBJECT_LOCK (pad);
4127 peerpad = GST_PAD_PEER (pad);
4128 if (peerpad == NULL)
4131 GST_LOG_OBJECT (pad, "sending event %s to peerpad %" GST_PTR_FORMAT,
4132 GST_EVENT_TYPE_NAME (event), peerpad);
4133 gst_object_ref (peerpad);
4134 GST_OBJECT_UNLOCK (pad);
4136 result = gst_pad_send_event (peerpad, event);
4138 /* Note: we gave away ownership of the event at this point */
4139 GST_LOG_OBJECT (pad, "sent event to peerpad %" GST_PTR_FORMAT ", result %d",
4141 gst_object_unref (peerpad);
4145 /* ERROR handling */
4148 GST_DEBUG_OBJECT (pad, "Dropping event after FALSE probe return");
4149 gst_event_unref (event);
4154 GST_DEBUG_OBJECT (pad, "Dropping event because pad is not linked");
4155 gst_event_unref (event);
4156 GST_OBJECT_UNLOCK (pad);
4161 GST_DEBUG_OBJECT (pad,
4162 "Not forwarding event since we're flushing and blocking");
4163 gst_event_unref (event);
4164 GST_OBJECT_UNLOCK (pad);
4170 * gst_pad_send_event:
4171 * @pad: a #GstPad to send the event to.
4172 * @event: the #GstEvent to send to the pad.
4174 * Sends the event to the pad. This function can be used
4175 * by applications to send events in the pipeline.
4177 * If @pad is a source pad, @event should be an upstream event. If @pad is a
4178 * sink pad, @event should be a downstream event. For example, you would not
4179 * send a #GST_EVENT_EOS on a src pad; EOS events only propagate downstream.
4180 * Furthermore, some downstream events have to be serialized with data flow,
4181 * like EOS, while some can travel out-of-band, like #GST_EVENT_FLUSH_START. If
4182 * the event needs to be serialized with data flow, this function will take the
4183 * pad's stream lock while calling its event function.
4185 * To find out whether an event type is upstream, downstream, or downstream and
4186 * serialized, see #GstEventTypeFlags, gst_event_type_get_flags(),
4187 * #GST_EVENT_IS_UPSTREAM, #GST_EVENT_IS_DOWNSTREAM, and
4188 * #GST_EVENT_IS_SERIALIZED. Note that in practice that an application or
4189 * plugin doesn't need to bother itself with this information; the core handles
4190 * all necessary locks and checks.
4192 * This function takes owership of the provided event so you should
4193 * gst_event_ref() it if you want to reuse the event after this call.
4195 * Returns: TRUE if the event was handled.
4198 gst_pad_send_event (GstPad * pad, GstEvent * event)
4200 gboolean result = FALSE;
4201 GstPadEventFunction eventfunc;
4202 gboolean serialized, need_unlock = FALSE;
4204 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
4205 g_return_val_if_fail (event != NULL, FALSE);
4207 GST_OBJECT_LOCK (pad);
4208 if (GST_PAD_IS_SINK (pad)) {
4209 if (G_UNLIKELY (!GST_EVENT_IS_DOWNSTREAM (event)))
4210 goto wrong_direction;
4211 serialized = GST_EVENT_IS_SERIALIZED (event);
4212 } else if (GST_PAD_IS_SRC (pad)) {
4213 if (G_UNLIKELY (!GST_EVENT_IS_UPSTREAM (event)))
4214 goto wrong_direction;
4215 /* events on srcpad never are serialized */
4218 goto unknown_direction;
4220 if (G_UNLIKELY (GST_EVENT_SRC (event) == NULL)) {
4221 GST_LOG_OBJECT (pad, "event had no source, setting pad as event source");
4222 GST_EVENT_SRC (event) = gst_object_ref (pad);
4226 if (G_UNLIKELY (GST_PAD_DO_EVENT_SIGNALS (pad) > 0)) {
4227 GST_OBJECT_UNLOCK (pad);
4229 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT_CAST (event)))
4232 GST_OBJECT_LOCK (pad);
4235 switch (GST_EVENT_TYPE (event)) {
4236 case GST_EVENT_FLUSH_START:
4237 GST_CAT_DEBUG_OBJECT (GST_CAT_EVENT, pad,
4238 "have event type %d (FLUSH_START)", GST_EVENT_TYPE (event));
4240 /* can't even accept a flush begin event when flushing */
4241 if (GST_PAD_IS_FLUSHING (pad))
4243 GST_PAD_SET_FLUSHING (pad);
4244 GST_CAT_DEBUG_OBJECT (GST_CAT_EVENT, pad, "set flush flag");
4246 case GST_EVENT_FLUSH_STOP:
4247 GST_PAD_UNSET_FLUSHING (pad);
4248 GST_CAT_DEBUG_OBJECT (GST_CAT_EVENT, pad, "cleared flush flag");
4249 GST_OBJECT_UNLOCK (pad);
4250 /* grab stream lock */
4251 GST_PAD_STREAM_LOCK (pad);
4253 GST_OBJECT_LOCK (pad);
4256 GST_CAT_DEBUG_OBJECT (GST_CAT_EVENT, pad, "have event type %s",
4257 GST_EVENT_TYPE_NAME (event));
4259 /* make this a little faster, no point in grabbing the lock
4260 * if the pad is allready flushing. */
4261 if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad)))
4265 /* lock order: STREAM_LOCK, LOCK, recheck flushing. */
4266 GST_OBJECT_UNLOCK (pad);
4267 GST_PAD_STREAM_LOCK (pad);
4269 GST_OBJECT_LOCK (pad);
4270 if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad)))
4275 if (G_UNLIKELY ((eventfunc = GST_PAD_EVENTFUNC (pad)) == NULL))
4278 GST_OBJECT_UNLOCK (pad);
4280 result = eventfunc (pad, event);
4283 GST_PAD_STREAM_UNLOCK (pad);
4285 GST_DEBUG_OBJECT (pad, "sent event, result %d", result);
4289 /* ERROR handling */
4292 g_warning ("pad %s:%s sending %s event in wrong direction",
4293 GST_DEBUG_PAD_NAME (pad), GST_EVENT_TYPE_NAME (event));
4294 GST_OBJECT_UNLOCK (pad);
4295 gst_event_unref (event);
4300 g_warning ("pad %s:%s has invalid direction", GST_DEBUG_PAD_NAME (pad));
4301 GST_OBJECT_UNLOCK (pad);
4302 gst_event_unref (event);
4307 g_warning ("pad %s:%s has no event handler, file a bug.",
4308 GST_DEBUG_PAD_NAME (pad));
4309 GST_OBJECT_UNLOCK (pad);
4311 GST_PAD_STREAM_UNLOCK (pad);
4312 gst_event_unref (event);
4317 GST_OBJECT_UNLOCK (pad);
4319 GST_PAD_STREAM_UNLOCK (pad);
4320 GST_CAT_INFO_OBJECT (GST_CAT_EVENT, pad,
4321 "Received event on flushing pad. Discarding");
4322 gst_event_unref (event);
4327 GST_DEBUG_OBJECT (pad, "Dropping event after FALSE probe return");
4328 gst_event_unref (event);
4334 * gst_pad_set_element_private:
4335 * @pad: the #GstPad to set the private data of.
4336 * @priv: The private data to attach to the pad.
4338 * Set the given private data gpointer on the pad.
4339 * This function can only be used by the element that owns the pad.
4340 * No locking is performed in this function.
4343 gst_pad_set_element_private (GstPad * pad, gpointer priv)
4345 pad->element_private = priv;
4349 * gst_pad_get_element_private:
4350 * @pad: the #GstPad to get the private data of.
4352 * Gets the private data of a pad.
4353 * No locking is performed in this function.
4355 * Returns: a #gpointer to the private data.
4358 gst_pad_get_element_private (GstPad * pad)
4360 return pad->element_private;
4364 * gst_pad_start_task:
4365 * @pad: the #GstPad to start the task of
4366 * @func: the task function to call
4367 * @data: data passed to the task function
4369 * Starts a task that repeatedly calls @func with @data. This function
4370 * is mostly used in pad activation functions to start the dataflow.
4371 * The #GST_PAD_STREAM_LOCK of @pad will automatically be acquired
4372 * before @func is called.
4374 * Returns: a %TRUE if the task could be started.
4377 gst_pad_start_task (GstPad * pad, GstTaskFunction func, gpointer data)
4381 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
4382 g_return_val_if_fail (func != NULL, FALSE);
4384 GST_DEBUG_OBJECT (pad, "start task");
4386 GST_OBJECT_LOCK (pad);
4387 task = GST_PAD_TASK (pad);
4389 task = gst_task_create (func, data);
4390 gst_task_set_lock (task, GST_PAD_GET_STREAM_LOCK (pad));
4391 GST_PAD_TASK (pad) = task;
4392 GST_DEBUG_OBJECT (pad, "created task");
4394 gst_task_start (task);
4395 GST_OBJECT_UNLOCK (pad);
4401 * gst_pad_pause_task:
4402 * @pad: the #GstPad to pause the task of
4404 * Pause the task of @pad. This function will also wait until the
4405 * function executed by the task is finished if this function is not
4406 * called from the task function.
4408 * Returns: a TRUE if the task could be paused or FALSE when the pad
4412 gst_pad_pause_task (GstPad * pad)
4416 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
4418 GST_DEBUG_OBJECT (pad, "pause task");
4420 GST_OBJECT_LOCK (pad);
4421 task = GST_PAD_TASK (pad);
4424 gst_task_pause (task);
4425 GST_OBJECT_UNLOCK (pad);
4427 /* wait for task function to finish, this lock is recursive so it does nothing
4428 * when the pause is called from the task itself */
4429 GST_PAD_STREAM_LOCK (pad);
4430 GST_PAD_STREAM_UNLOCK (pad);
4436 GST_DEBUG_OBJECT (pad, "pad has no task");
4437 GST_OBJECT_UNLOCK (pad);
4443 * gst_pad_stop_task:
4444 * @pad: the #GstPad to stop the task of
4446 * Stop the task of @pad. This function will also make sure that the
4447 * function executed by the task will effectively stop if not called
4448 * from the GstTaskFunction.
4450 * This function will deadlock if called from the GstTaskFunction of
4451 * the task. Use gst_task_pause() instead.
4453 * Regardless of whether the pad has a task, the stream lock is acquired and
4454 * released so as to ensure that streaming through this pad has finished.
4456 * Returns: a TRUE if the task could be stopped or FALSE on error.
4459 gst_pad_stop_task (GstPad * pad)
4463 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
4465 GST_DEBUG_OBJECT (pad, "stop task");
4467 GST_OBJECT_LOCK (pad);
4468 task = GST_PAD_TASK (pad);
4471 GST_PAD_TASK (pad) = NULL;
4472 gst_task_stop (task);
4473 GST_OBJECT_UNLOCK (pad);
4475 GST_PAD_STREAM_LOCK (pad);
4476 GST_PAD_STREAM_UNLOCK (pad);
4478 if (!gst_task_join (task))
4481 gst_object_unref (task);
4487 GST_DEBUG_OBJECT (pad, "no task");
4488 GST_OBJECT_UNLOCK (pad);
4490 GST_PAD_STREAM_LOCK (pad);
4491 GST_PAD_STREAM_UNLOCK (pad);
4493 /* this is not an error */
4498 /* this is bad, possibly the application tried to join the task from
4499 * the task's thread. We install the task again so that it will be stopped
4500 * again from the right thread next time hopefully. */
4501 GST_OBJECT_LOCK (pad);
4502 GST_DEBUG_OBJECT (pad, "join failed");
4503 /* we can only install this task if there was no other task */
4504 if (GST_PAD_TASK (pad) == NULL)
4505 GST_PAD_TASK (pad) = task;
4506 GST_OBJECT_UNLOCK (pad);