2 * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
3 * 2000 Wim Taymans <wtay@chello.be>
5 * gstpad.c: Pads for linking elements together
7 * This library is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Library General Public
9 * License as published by the Free Software Foundation; either
10 * version 2 of the License, or (at your option) any later version.
12 * This library is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Library General Public License for more details.
17 * You should have received a copy of the GNU Library General Public
18 * License along with this library; if not, write to the
19 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
20 * Boston, MA 02111-1307, USA.
24 * @short_description: Object contained by elements that allows links to
26 * @see_also: #GstPadTemplate, #GstElement, #GstEvent
28 * A #GstElement is linked to other elements via "pads", which are extremely
29 * light-weight generic link points.
30 * After two pads are retrieved from an element with gst_element_get_pad(),
31 * the pads can be link with gst_pad_link(). (For quick links,
32 * you can also use gst_element_link(), which will make the obvious
33 * link for you if it's straightforward.)
35 * Pads are typically created from a #GstPadTemplate with
36 * gst_pad_new_from_template().
38 * Pads have #GstCaps attached to it to describe the media type they are
39 * capable of dealing with. gst_pad_get_caps() and gst_pad_set_caps() are
40 * used to manipulate the caps of the pads.
41 * Pads created from a pad template cannot set capabilities that are
42 * incompatible with the pad template capabilities.
44 * Pads without pad templates can be created with gst_pad_new(),
45 * which takes a direction and a name as an argument. If the name is NULL,
46 * then a guaranteed unique name will be assigned to it.
48 * gst_pad_get_parent() will retrieve the #GstElement that owns the pad.
50 * A #GstElement creating a pad will typically use the various
51 * gst_pad_set_*_function() calls to register callbacks for various events
54 * GstElements will use gst_pad_push() and gst_pad_pull_range() to push out
55 * or pull in a buffer.
57 * To send a #GstEvent on a pad, use gst_pad_send_event() and
58 * gst_pad_push_event().
60 * Last reviewed on 2006-07-06 (0.10.9)
63 #include "gst_private.h"
66 #include "gstpadtemplate.h"
67 #include "gstenumtypes.h"
68 #include "gstmarshal.h"
73 #include "glib-compat-private.h"
75 GST_DEBUG_CATEGORY_STATIC (debug_dataflow);
76 #define GST_CAT_DEFAULT GST_CAT_PADS
78 /* Pad signals and args */
98 static void gst_pad_class_init (GstPadClass * klass);
99 static void gst_pad_init (GstPad * pad);
100 static void gst_pad_dispose (GObject * object);
101 static void gst_pad_finalize (GObject * object);
102 static void gst_pad_set_property (GObject * object, guint prop_id,
103 const GValue * value, GParamSpec * pspec);
104 static void gst_pad_get_property (GObject * object, guint prop_id,
105 GValue * value, GParamSpec * pspec);
107 static GstFlowReturn handle_pad_block (GstPad * pad);
108 static GstCaps *gst_pad_get_caps_unlocked (GstPad * pad);
109 static void gst_pad_set_pad_template (GstPad * pad, GstPadTemplate * templ);
110 static gboolean gst_pad_activate_default (GstPad * pad);
111 static gboolean gst_pad_acceptcaps_default (GstPad * pad, GstCaps * caps);
113 #ifndef GST_DISABLE_LOADSAVE
114 static xmlNodePtr gst_pad_save_thyself (GstObject * object, xmlNodePtr parent);
117 static GstObjectClass *parent_class = NULL;
118 static guint gst_pad_signals[LAST_SIGNAL] = { 0 };
120 /* quarks for probe signals */
121 static GQuark buffer_quark;
122 static GQuark event_quark;
131 static GstFlowQuarks flow_quarks[] = {
132 {GST_FLOW_CUSTOM_SUCCESS, "custom-success", 0},
133 {GST_FLOW_RESEND, "resend", 0},
134 {GST_FLOW_OK, "ok", 0},
135 {GST_FLOW_NOT_LINKED, "not-linked", 0},
136 {GST_FLOW_WRONG_STATE, "wrong-state", 0},
137 {GST_FLOW_UNEXPECTED, "unexpected", 0},
138 {GST_FLOW_NOT_NEGOTIATED, "not-negotiated", 0},
139 {GST_FLOW_ERROR, "error", 0},
140 {GST_FLOW_NOT_SUPPORTED, "not-supported", 0},
141 {GST_FLOW_CUSTOM_ERROR, "custom-error", 0},
148 * @ret: a #GstFlowReturn to get the name of.
150 * Gets a string representing the given flow return.
152 * Returns: a static string with the name of the flow return.
154 G_CONST_RETURN gchar *
155 gst_flow_get_name (GstFlowReturn ret)
159 ret = CLAMP (ret, GST_FLOW_CUSTOM_ERROR, GST_FLOW_CUSTOM_SUCCESS);
161 for (i = 0; flow_quarks[i].name; i++) {
162 if (ret == flow_quarks[i].ret)
163 return flow_quarks[i].name;
170 * @ret: a #GstFlowReturn to get the quark of.
172 * Get the unique quark for the given GstFlowReturn.
174 * Returns: the quark associated with the flow return or 0 if an
175 * invalid return was specified.
178 gst_flow_to_quark (GstFlowReturn ret)
182 ret = CLAMP (ret, GST_FLOW_CUSTOM_ERROR, GST_FLOW_CUSTOM_SUCCESS);
184 for (i = 0; flow_quarks[i].name; i++) {
185 if (ret == flow_quarks[i].ret)
186 return flow_quarks[i].quark;
192 gst_pad_get_type (void)
194 static GType gst_pad_type = 0;
196 if (G_UNLIKELY (gst_pad_type == 0)) {
197 static const GTypeInfo pad_info = {
198 sizeof (GstPadClass), NULL, NULL,
199 (GClassInitFunc) gst_pad_class_init, NULL, NULL,
202 (GInstanceInitFunc) gst_pad_init, NULL
206 gst_pad_type = g_type_register_static (GST_TYPE_OBJECT, "GstPad",
209 buffer_quark = g_quark_from_static_string ("buffer");
210 event_quark = g_quark_from_static_string ("event");
212 for (i = 0; flow_quarks[i].name; i++) {
213 flow_quarks[i].quark = g_quark_from_static_string (flow_quarks[i].name);
216 GST_DEBUG_CATEGORY_INIT (debug_dataflow, "GST_DATAFLOW",
217 GST_DEBUG_BOLD | GST_DEBUG_FG_GREEN, "dataflow inside pads");
223 _gst_do_pass_data_accumulator (GSignalInvocationHint * ihint,
224 GValue * return_accu, const GValue * handler_return, gpointer dummy)
226 gboolean ret = g_value_get_boolean (handler_return);
228 GST_DEBUG ("accumulated %d", ret);
229 g_value_set_boolean (return_accu, ret);
235 default_have_data (GstPad * pad, GstMiniObject * o)
241 gst_pad_class_init (GstPadClass * klass)
243 GObjectClass *gobject_class;
244 GstObjectClass *gstobject_class;
246 gobject_class = G_OBJECT_CLASS (klass);
247 gstobject_class = GST_OBJECT_CLASS (klass);
249 parent_class = g_type_class_peek_parent (klass);
251 gobject_class->dispose = GST_DEBUG_FUNCPTR (gst_pad_dispose);
252 gobject_class->finalize = GST_DEBUG_FUNCPTR (gst_pad_finalize);
253 gobject_class->set_property = GST_DEBUG_FUNCPTR (gst_pad_set_property);
254 gobject_class->get_property = GST_DEBUG_FUNCPTR (gst_pad_get_property);
258 * @pad: the pad that emitted the signal
259 * @peer: the peer pad that has been connected
261 * Signals that a pad has been linked to the peer pad.
263 gst_pad_signals[PAD_LINKED] =
264 g_signal_new ("linked", G_TYPE_FROM_CLASS (klass), G_SIGNAL_RUN_LAST,
265 G_STRUCT_OFFSET (GstPadClass, linked), NULL, NULL,
266 gst_marshal_VOID__OBJECT, G_TYPE_NONE, 1, GST_TYPE_PAD);
269 * @pad: the pad that emitted the signal
270 * @peer: the peer pad that has been disconnected
272 * Signals that a pad has been unlinked from the peer pad.
274 gst_pad_signals[PAD_UNLINKED] =
275 g_signal_new ("unlinked", G_TYPE_FROM_CLASS (klass), G_SIGNAL_RUN_LAST,
276 G_STRUCT_OFFSET (GstPadClass, unlinked), NULL, NULL,
277 gst_marshal_VOID__OBJECT, G_TYPE_NONE, 1, GST_TYPE_PAD);
279 * GstPad::request-link:
280 * @pad: the pad that emitted the signal
281 * @peer: the peer pad for which a connection is requested
283 * Signals that a pad connection has been requested.
285 gst_pad_signals[PAD_REQUEST_LINK] =
286 g_signal_new ("request-link", G_TYPE_FROM_CLASS (klass),
287 G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GstPadClass, request_link), NULL,
288 NULL, gst_marshal_VOID__OBJECT, G_TYPE_NONE, 0);
292 * @pad: the pad that emitted the signal
293 * @mini_obj: new data
295 * Signals that new data is available on the pad. This signal is used
296 * internally for implementing pad probes.
297 * See gst_pad_add_*_probe functions.
299 * Returns: %TRUE to keep the data, %FALSE to drop it
301 gst_pad_signals[PAD_HAVE_DATA] =
302 g_signal_new ("have-data", G_TYPE_FROM_CLASS (klass),
303 G_SIGNAL_RUN_LAST | G_SIGNAL_DETAILED,
304 G_STRUCT_OFFSET (GstPadClass, have_data),
305 _gst_do_pass_data_accumulator,
306 NULL, gst_marshal_BOOLEAN__POINTER, G_TYPE_BOOLEAN, 1,
307 GST_TYPE_MINI_OBJECT);
309 g_object_class_install_property (gobject_class, PAD_PROP_CAPS,
310 g_param_spec_boxed ("caps", "Caps", "The capabilities of the pad",
311 GST_TYPE_CAPS, G_PARAM_READABLE));
312 g_object_class_install_property (gobject_class, PAD_PROP_DIRECTION,
313 g_param_spec_enum ("direction", "Direction", "The direction of the pad",
314 GST_TYPE_PAD_DIRECTION, GST_PAD_UNKNOWN,
315 G_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY));
316 /* FIXME, Make G_PARAM_CONSTRUCT_ONLY when we fix ghostpads. */
317 g_object_class_install_property (gobject_class, PAD_PROP_TEMPLATE,
318 g_param_spec_object ("template", "Template",
319 "The GstPadTemplate of this pad", GST_TYPE_PAD_TEMPLATE,
322 #ifndef GST_DISABLE_LOADSAVE
323 gstobject_class->save_thyself = GST_DEBUG_FUNCPTR (gst_pad_save_thyself);
325 gstobject_class->path_string_separator = ".";
327 klass->have_data = default_have_data;
331 gst_pad_init (GstPad * pad)
333 GST_PAD_DIRECTION (pad) = GST_PAD_UNKNOWN;
334 GST_PAD_PEER (pad) = NULL;
336 GST_PAD_CHAINFUNC (pad) = NULL;
338 GST_PAD_LINKFUNC (pad) = NULL;
340 GST_PAD_CAPS (pad) = NULL;
341 GST_PAD_GETCAPSFUNC (pad) = NULL;
343 GST_PAD_ACTIVATEFUNC (pad) = GST_DEBUG_FUNCPTR (gst_pad_activate_default);
344 GST_PAD_EVENTFUNC (pad) = GST_DEBUG_FUNCPTR (gst_pad_event_default);
345 GST_PAD_QUERYTYPEFUNC (pad) =
346 GST_DEBUG_FUNCPTR (gst_pad_get_query_types_default);
347 GST_PAD_QUERYFUNC (pad) = GST_DEBUG_FUNCPTR (gst_pad_query_default);
348 GST_PAD_INTLINKFUNC (pad) =
349 GST_DEBUG_FUNCPTR (gst_pad_get_internal_links_default);
350 GST_PAD_ACCEPTCAPSFUNC (pad) = GST_DEBUG_FUNCPTR (gst_pad_acceptcaps_default);
352 pad->do_buffer_signals = 0;
353 pad->do_event_signals = 0;
355 /* FIXME, should be set flushing initially, see #339326 */
356 GST_PAD_UNSET_FLUSHING (pad);
358 pad->preroll_lock = g_mutex_new ();
359 pad->preroll_cond = g_cond_new ();
361 pad->stream_rec_lock = g_new (GStaticRecMutex, 1);
362 g_static_rec_mutex_init (pad->stream_rec_lock);
364 pad->block_cond = g_cond_new ();
368 gst_pad_dispose (GObject * object)
370 GstPad *pad = GST_PAD (object);
372 GST_CAT_DEBUG_OBJECT (GST_CAT_REFCOUNTING, pad, "dispose");
374 /* we don't hold a ref to the peer so we can just set the
376 GST_PAD_PEER (pad) = NULL;
379 gst_caps_replace (&GST_PAD_CAPS (pad), NULL);
381 gst_pad_set_pad_template (pad, NULL);
383 G_OBJECT_CLASS (parent_class)->dispose (object);
387 gst_pad_finalize (GObject * object)
389 GstPad *pad = GST_PAD (object);
392 /* in case the task is still around, clean it up */
393 if ((task = GST_PAD_TASK (pad))) {
394 gst_task_join (task);
395 GST_PAD_TASK (pad) = NULL;
396 gst_object_unref (task);
399 if (pad->stream_rec_lock) {
400 g_static_rec_mutex_free (pad->stream_rec_lock);
401 g_free (pad->stream_rec_lock);
402 pad->stream_rec_lock = NULL;
404 if (pad->preroll_lock) {
405 g_mutex_free (pad->preroll_lock);
406 g_cond_free (pad->preroll_cond);
407 pad->preroll_lock = NULL;
408 pad->preroll_cond = NULL;
410 if (pad->block_cond) {
411 g_cond_free (pad->block_cond);
412 pad->block_cond = NULL;
415 G_OBJECT_CLASS (parent_class)->finalize (object);
419 gst_pad_set_property (GObject * object, guint prop_id,
420 const GValue * value, GParamSpec * pspec)
422 g_return_if_fail (GST_IS_PAD (object));
425 case PAD_PROP_DIRECTION:
426 GST_PAD_DIRECTION (object) = g_value_get_enum (value);
428 case PAD_PROP_TEMPLATE:
429 gst_pad_set_pad_template (GST_PAD_CAST (object),
430 (GstPadTemplate *) g_value_get_object (value));
433 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
439 gst_pad_get_property (GObject * object, guint prop_id,
440 GValue * value, GParamSpec * pspec)
442 g_return_if_fail (GST_IS_PAD (object));
446 GST_OBJECT_LOCK (object);
447 g_value_set_boxed (value, GST_PAD_CAPS (object));
448 GST_OBJECT_UNLOCK (object);
450 case PAD_PROP_DIRECTION:
451 g_value_set_enum (value, GST_PAD_DIRECTION (object));
453 case PAD_PROP_TEMPLATE:
454 g_value_set_object (value, GST_PAD_PAD_TEMPLATE (object));
457 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
464 * @name: the name of the new pad.
465 * @direction: the #GstPadDirection of the pad.
467 * Creates a new pad with the given name in the given direction.
468 * If name is NULL, a guaranteed unique name (across all pads)
470 * This function makes a copy of the name so you can safely free the name.
472 * Returns: a new #GstPad, or NULL in case of an error.
477 gst_pad_new (const gchar * name, GstPadDirection direction)
479 return g_object_new (GST_TYPE_PAD,
480 "name", name, "direction", direction, NULL);
484 * gst_pad_new_from_template:
485 * @templ: the pad template to use
486 * @name: the name of the element
488 * Creates a new pad with the given name from the given template.
489 * If name is NULL, a guaranteed unique name (across all pads)
491 * This function makes a copy of the name so you can safely free the name.
493 * Returns: a new #GstPad, or NULL in case of an error.
496 gst_pad_new_from_template (GstPadTemplate * templ, const gchar * name)
498 g_return_val_if_fail (GST_IS_PAD_TEMPLATE (templ), NULL);
500 return g_object_new (GST_TYPE_PAD,
501 "name", name, "direction", templ->direction, "template", templ, NULL);
505 * gst_pad_new_from_static_template:
506 * @templ: the #GstStaticPadTemplate to use
507 * @name: the name of the element
509 * Creates a new pad with the given name from the given static template.
510 * If name is NULL, a guaranteed unique name (across all pads)
512 * This function makes a copy of the name so you can safely free the name.
514 * Returns: a new #GstPad, or NULL in case of an error.
517 gst_pad_new_from_static_template (GstStaticPadTemplate * templ,
521 GstPadTemplate *template;
523 template = gst_static_pad_template_get (templ);
524 pad = gst_pad_new_from_template (template, name);
525 gst_object_unref (template);
530 * gst_pad_get_direction:
531 * @pad: a #GstPad to get the direction of.
533 * Gets the direction of the pad. The direction of the pad is
534 * decided at construction time so this function does not take
537 * Returns: the #GstPadDirection of the pad.
542 gst_pad_get_direction (GstPad * pad)
544 GstPadDirection result;
546 /* PAD_UNKNOWN is a little silly but we need some sort of
547 * error return value */
548 g_return_val_if_fail (GST_IS_PAD (pad), GST_PAD_UNKNOWN);
550 GST_OBJECT_LOCK (pad);
551 result = GST_PAD_DIRECTION (pad);
552 GST_OBJECT_UNLOCK (pad);
558 gst_pad_activate_default (GstPad * pad)
560 return gst_pad_activate_push (pad, TRUE);
564 pre_activate (GstPad * pad, GstActivateMode new_mode)
567 case GST_ACTIVATE_PUSH:
568 case GST_ACTIVATE_PULL:
569 GST_OBJECT_LOCK (pad);
570 GST_DEBUG_OBJECT (pad, "setting ACTIVATE_MODE %d, unset flushing",
572 GST_PAD_UNSET_FLUSHING (pad);
573 GST_PAD_ACTIVATE_MODE (pad) = new_mode;
574 GST_OBJECT_UNLOCK (pad);
576 case GST_ACTIVATE_NONE:
577 GST_OBJECT_LOCK (pad);
578 GST_DEBUG_OBJECT (pad, "setting ACTIVATE_MODE NONE, set flushing");
579 GST_PAD_SET_FLUSHING (pad);
580 /* unlock blocked pads so element can resume and stop */
581 GST_PAD_BLOCK_SIGNAL (pad);
582 GST_OBJECT_UNLOCK (pad);
588 post_activate (GstPad * pad, GstActivateMode new_mode)
591 case GST_ACTIVATE_PUSH:
592 case GST_ACTIVATE_PULL:
595 case GST_ACTIVATE_NONE:
596 /* ensures that streaming stops */
597 GST_PAD_STREAM_LOCK (pad);
598 /* while we're at it set activation mode */
599 GST_OBJECT_LOCK (pad);
600 GST_DEBUG_OBJECT (pad, "setting ACTIVATE_MODE %d", new_mode);
601 GST_PAD_ACTIVATE_MODE (pad) = new_mode;
602 GST_OBJECT_UNLOCK (pad);
603 GST_PAD_STREAM_UNLOCK (pad);
609 * gst_pad_set_active:
610 * @pad: the #GstPad to activate or deactivate.
611 * @active: whether or not the pad should be active.
613 * Activates or deactivates the given pad.
614 * Normally called from within core state change functions.
616 * If @active, makes sure the pad is active. If it is already active, either in
617 * push or pull mode, just return. Otherwise dispatches to the pad's activate
618 * function to perform the actual activation.
620 * If not @active, checks the pad's current mode and calls
621 * gst_pad_activate_push() or gst_pad_activate_pull(), as appropriate, with a
624 * Returns: #TRUE if the operation was successful.
629 gst_pad_set_active (GstPad * pad, gboolean active)
632 gboolean ret = FALSE;
634 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
636 GST_OBJECT_LOCK (pad);
637 old = GST_PAD_ACTIVATE_MODE (pad);
638 GST_OBJECT_UNLOCK (pad);
642 case GST_ACTIVATE_PUSH:
643 case GST_ACTIVATE_PULL:
646 case GST_ACTIVATE_NONE:
647 ret = (GST_PAD_ACTIVATEFUNC (pad)) (pad);
652 case GST_ACTIVATE_PUSH:
653 ret = gst_pad_activate_push (pad, FALSE);
655 case GST_ACTIVATE_PULL:
656 ret = gst_pad_activate_pull (pad, FALSE);
658 case GST_ACTIVATE_NONE:
665 GST_OBJECT_LOCK (pad);
667 g_critical ("Failed to deactivate pad %s:%s, very bad",
668 GST_DEBUG_PAD_NAME (pad));
670 GST_WARNING ("Failed to activate pad %s:%s", GST_DEBUG_PAD_NAME (pad));
672 GST_OBJECT_UNLOCK (pad);
679 * gst_pad_activate_pull:
680 * @pad: the #GstPad to activate or deactivate.
681 * @active: whether or not the pad should be active.
683 * Activates or deactivates the given pad in pull mode via dispatching to the
684 * pad's activatepullfunc. For use from within pad activation functions only.
685 * When called on sink pads, will first proxy the call to the peer pad, which is
686 * expected to activate its internally linked pads from within its activate_pull
689 * If you don't know what this is, you probably don't want to call it.
691 * Returns: TRUE if the operation was successful.
696 gst_pad_activate_pull (GstPad * pad, gboolean active)
698 GstActivateMode old, new;
701 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
703 GST_OBJECT_LOCK (pad);
704 old = GST_PAD_ACTIVATE_MODE (pad);
705 GST_OBJECT_UNLOCK (pad);
709 case GST_ACTIVATE_PULL:
711 case GST_ACTIVATE_PUSH:
712 /* pad was activate in the wrong direction, deactivate it
713 * and reactivate it in pull mode */
714 if (G_UNLIKELY (!gst_pad_activate_push (pad, FALSE)))
715 goto deactivate_failed;
716 /* fallthrough, pad is deactivated now. */
717 case GST_ACTIVATE_NONE:
722 case GST_ACTIVATE_NONE:
724 case GST_ACTIVATE_PUSH:
725 /* pad was activated in the other direction, deactivate it
726 * in push mode, this should not happen... */
727 if (G_UNLIKELY (!gst_pad_activate_push (pad, FALSE)))
728 goto deactivate_failed;
729 /* everything is fine now */
731 case GST_ACTIVATE_PULL:
736 if (gst_pad_get_direction (pad) == GST_PAD_SINK) {
737 if ((peer = gst_pad_get_peer (pad))) {
738 if (G_UNLIKELY (!gst_pad_activate_pull (peer, active)))
740 gst_object_unref (peer);
743 if (G_UNLIKELY (GST_PAD_GETRANGEFUNC (pad) == NULL))
744 goto failure; /* Can't activate pull on a src without a
748 new = active ? GST_ACTIVATE_PULL : GST_ACTIVATE_NONE;
749 pre_activate (pad, new);
751 if (GST_PAD_ACTIVATEPULLFUNC (pad)) {
752 if (G_UNLIKELY (!GST_PAD_ACTIVATEPULLFUNC (pad) (pad, active)))
755 /* can happen for sinks of passthrough elements */
758 post_activate (pad, new);
760 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "%s in pull mode",
761 active ? "activated" : "deactivated");
767 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "already %s in pull mode",
768 active ? "activated" : "deactivated");
773 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
774 "failed to %s in switch to pull from mode %d",
775 (active ? "activate" : "deactivate"), old);
780 GST_OBJECT_LOCK (peer);
781 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
782 "activate_pull on peer (%s:%s) failed", GST_DEBUG_PAD_NAME (peer));
783 GST_OBJECT_UNLOCK (peer);
784 gst_object_unref (peer);
789 GST_OBJECT_LOCK (pad);
790 GST_CAT_INFO_OBJECT (GST_CAT_PADS, pad, "failed to %s in pull mode",
791 active ? "activate" : "deactivate");
792 GST_PAD_SET_FLUSHING (pad);
793 GST_PAD_ACTIVATE_MODE (pad) = old;
794 GST_OBJECT_UNLOCK (pad);
800 * gst_pad_activate_push:
801 * @pad: the #GstPad to activate or deactivate.
802 * @active: whether the pad should be active or not.
804 * Activates or deactivates the given pad in push mode via dispatching to the
805 * pad's activatepushfunc. For use from within pad activation functions only.
807 * If you don't know what this is, you probably don't want to call it.
809 * Returns: %TRUE if the operation was successful.
814 gst_pad_activate_push (GstPad * pad, gboolean active)
816 GstActivateMode old, new;
818 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
819 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "trying to set %s in push mode",
820 active ? "activated" : "deactivated");
822 GST_OBJECT_LOCK (pad);
823 old = GST_PAD_ACTIVATE_MODE (pad);
824 GST_OBJECT_UNLOCK (pad);
828 case GST_ACTIVATE_PUSH:
830 case GST_ACTIVATE_PULL:
831 /* pad was activate in the wrong direction, deactivate it
832 * an reactivate it in push mode */
833 if (G_UNLIKELY (!gst_pad_activate_pull (pad, FALSE)))
834 goto deactivate_failed;
835 /* fallthrough, pad is deactivated now. */
836 case GST_ACTIVATE_NONE:
841 case GST_ACTIVATE_NONE:
843 case GST_ACTIVATE_PULL:
844 /* pad was activated in the other direction, deactivate it
845 * in pull mode, this should not happen... */
846 if (G_UNLIKELY (!gst_pad_activate_pull (pad, FALSE)))
847 goto deactivate_failed;
848 /* everything is fine now */
850 case GST_ACTIVATE_PUSH:
855 new = active ? GST_ACTIVATE_PUSH : GST_ACTIVATE_NONE;
856 pre_activate (pad, new);
858 if (GST_PAD_ACTIVATEPUSHFUNC (pad)) {
859 if (G_UNLIKELY (!GST_PAD_ACTIVATEPUSHFUNC (pad) (pad, active))) {
863 /* quite ok, element relies on state change func to prepare itself */
866 post_activate (pad, new);
868 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "%s in push mode",
869 active ? "activated" : "deactivated");
874 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "already %s in push mode",
875 active ? "activated" : "deactivated");
880 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
881 "failed to %s in switch to push from mode %d",
882 (active ? "activate" : "deactivate"), old);
887 GST_OBJECT_LOCK (pad);
888 GST_CAT_INFO_OBJECT (GST_CAT_PADS, pad, "failed to %s in push mode",
889 active ? "activate" : "deactivate");
890 GST_PAD_SET_FLUSHING (pad);
891 GST_PAD_ACTIVATE_MODE (pad) = old;
892 GST_OBJECT_UNLOCK (pad);
899 * @pad: the #GstPad to query
901 * Query if a pad is active
903 * Returns: TRUE if the pad is active.
908 gst_pad_is_active (GstPad * pad)
910 gboolean result = FALSE;
912 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
914 GST_OBJECT_LOCK (pad);
915 result = GST_PAD_MODE_ACTIVATE (GST_PAD_ACTIVATE_MODE (pad));
916 GST_OBJECT_UNLOCK (pad);
922 * gst_pad_set_blocked_async:
923 * @pad: the #GstPad to block or unblock
924 * @blocked: boolean indicating whether the pad should be blocked or unblocked
925 * @callback: #GstPadBlockCallback that will be called when the
927 * @user_data: user data passed to the callback
929 * Blocks or unblocks the dataflow on a pad. The provided callback
930 * is called when the operation succeeds; this happens right before the next
931 * attempt at pushing a buffer on the pad.
933 * This can take a while as the pad can only become blocked when real dataflow
935 * When the pipeline is stalled, for example in PAUSED, this can
936 * take an indeterminate amount of time.
937 * You can pass NULL as the callback to make this call block. Be careful with
938 * this blocking call as it might not return for reasons stated above.
940 * Returns: TRUE if the pad could be blocked. This function can fail
941 * if wrong parameters were passed or the pad was already in the
947 gst_pad_set_blocked_async (GstPad * pad, gboolean blocked,
948 GstPadBlockCallback callback, gpointer user_data)
950 gboolean was_blocked = FALSE;
952 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
954 GST_OBJECT_LOCK (pad);
956 was_blocked = GST_PAD_IS_BLOCKED (pad);
958 if (G_UNLIKELY (was_blocked == blocked))
959 goto had_right_state;
962 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "blocking pad");
964 GST_OBJECT_FLAG_SET (pad, GST_PAD_BLOCKED);
965 pad->block_callback = callback;
966 pad->block_data = user_data;
968 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "waiting for block");
969 GST_PAD_BLOCK_WAIT (pad);
970 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "blocked");
973 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "unblocking pad");
975 GST_OBJECT_FLAG_UNSET (pad, GST_PAD_BLOCKED);
977 pad->block_callback = callback;
978 pad->block_data = user_data;
981 GST_PAD_BLOCK_SIGNAL (pad);
983 GST_PAD_BLOCK_SIGNAL (pad);
984 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "waiting for unblock");
985 GST_PAD_BLOCK_WAIT (pad);
986 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "unblocked");
989 GST_OBJECT_UNLOCK (pad);
995 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
996 "pad was in right state (%d)", was_blocked);
997 GST_OBJECT_UNLOCK (pad);
1004 * gst_pad_set_blocked:
1005 * @pad: the #GstPad to block or unblock
1006 * @blocked: boolean indicating we should block or unblock
1008 * Blocks or unblocks the dataflow on a pad. This function is
1009 * a shortcut for gst_pad_set_blocked_async() with a NULL
1012 * Returns: TRUE if the pad could be blocked. This function can fail
1013 * wrong parameters were passed or the pad was already in the
1019 gst_pad_set_blocked (GstPad * pad, gboolean blocked)
1021 return gst_pad_set_blocked_async (pad, blocked, NULL, NULL);
1025 * gst_pad_is_blocked:
1026 * @pad: the #GstPad to query
1028 * Checks if the pad is blocked or not. This function returns the
1029 * last requested state of the pad. It is not certain that the pad
1030 * is actually blocking at this point (see gst_pad_is_blocking()).
1032 * Returns: TRUE if the pad is blocked.
1037 gst_pad_is_blocked (GstPad * pad)
1039 gboolean result = FALSE;
1041 g_return_val_if_fail (GST_IS_PAD (pad), result);
1043 GST_OBJECT_LOCK (pad);
1044 result = GST_OBJECT_FLAG_IS_SET (pad, GST_PAD_BLOCKED);
1045 GST_OBJECT_UNLOCK (pad);
1051 * gst_pad_is_blocking:
1052 * @pad: the #GstPad to query
1054 * Checks if the pad is blocking or not. This is a guaranteed state
1055 * of whether the pad is actually blocking on a #GstBuffer or a #GstEvent.
1057 * Returns: TRUE if the pad is blocking.
1064 gst_pad_is_blocking (GstPad * pad)
1066 gboolean result = FALSE;
1068 g_return_val_if_fail (GST_IS_PAD (pad), result);
1070 GST_OBJECT_LOCK (pad);
1071 /* the blocking flag is only valid if the pad is not flushing */
1072 result = GST_OBJECT_FLAG_IS_SET (pad, GST_PAD_BLOCKING) &&
1073 !GST_OBJECT_FLAG_IS_SET (pad, GST_PAD_FLUSHING);
1074 GST_OBJECT_UNLOCK (pad);
1080 * gst_pad_set_activate_function:
1082 * @activate: the #GstPadActivateFunction to set.
1084 * Sets the given activate function for @pad. The activate function will
1085 * dispatch to gst_pad_activate_push() or gst_pad_activate_pull() to perform
1086 * the actual activation. Only makes sense to set on sink pads.
1088 * Call this function if your sink pad can start a pull-based task.
1091 gst_pad_set_activate_function (GstPad * pad, GstPadActivateFunction activate)
1093 g_return_if_fail (GST_IS_PAD (pad));
1095 GST_PAD_ACTIVATEFUNC (pad) = activate;
1096 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "activatefunc set to %s",
1097 GST_DEBUG_FUNCPTR_NAME (activate));
1101 * gst_pad_set_activatepull_function:
1103 * @activatepull: the #GstPadActivateModeFunction to set.
1105 * Sets the given activate_pull function for the pad. An activate_pull function
1106 * prepares the element and any upstream connections for pulling. See XXX
1107 * part-activation.txt for details.
1110 gst_pad_set_activatepull_function (GstPad * pad,
1111 GstPadActivateModeFunction activatepull)
1113 g_return_if_fail (GST_IS_PAD (pad));
1115 GST_PAD_ACTIVATEPULLFUNC (pad) = activatepull;
1116 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "activatepullfunc set to %s",
1117 GST_DEBUG_FUNCPTR_NAME (activatepull));
1121 * gst_pad_set_activatepush_function:
1123 * @activatepush: the #GstPadActivateModeFunction to set.
1125 * Sets the given activate_push function for the pad. An activate_push function
1126 * prepares the element for pushing. See XXX part-activation.txt for details.
1129 gst_pad_set_activatepush_function (GstPad * pad,
1130 GstPadActivateModeFunction activatepush)
1132 g_return_if_fail (GST_IS_PAD (pad));
1134 GST_PAD_ACTIVATEPUSHFUNC (pad) = activatepush;
1135 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "activatepushfunc set to %s",
1136 GST_DEBUG_FUNCPTR_NAME (activatepush));
1140 * gst_pad_set_chain_function:
1141 * @pad: a sink #GstPad.
1142 * @chain: the #GstPadChainFunction to set.
1144 * Sets the given chain function for the pad. The chain function is called to
1145 * process a #GstBuffer input buffer. see #GstPadChainFunction for more details.
1148 gst_pad_set_chain_function (GstPad * pad, GstPadChainFunction chain)
1150 g_return_if_fail (GST_IS_PAD (pad));
1151 g_return_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SINK);
1153 GST_PAD_CHAINFUNC (pad) = chain;
1154 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "chainfunc set to %s",
1155 GST_DEBUG_FUNCPTR_NAME (chain));
1159 * gst_pad_set_getrange_function:
1160 * @pad: a source #GstPad.
1161 * @get: the #GstPadGetRangeFunction to set.
1163 * Sets the given getrange function for the pad. The getrange function is called to
1164 * produce a new #GstBuffer to start the processing pipeline. see
1165 * #GstPadGetRangeFunction for a description of the getrange function.
1168 gst_pad_set_getrange_function (GstPad * pad, GstPadGetRangeFunction get)
1170 g_return_if_fail (GST_IS_PAD (pad));
1171 g_return_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SRC);
1173 GST_PAD_GETRANGEFUNC (pad) = get;
1175 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "getrangefunc set to %s",
1176 GST_DEBUG_FUNCPTR_NAME (get));
1180 * gst_pad_set_checkgetrange_function:
1181 * @pad: a source #GstPad.
1182 * @check: the #GstPadCheckGetRangeFunction to set.
1184 * Sets the given checkgetrange function for the pad. Implement this function on
1185 * a pad if you dynamically support getrange based scheduling on the pad.
1188 gst_pad_set_checkgetrange_function (GstPad * pad,
1189 GstPadCheckGetRangeFunction check)
1191 g_return_if_fail (GST_IS_PAD (pad));
1192 g_return_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SRC);
1194 GST_PAD_CHECKGETRANGEFUNC (pad) = check;
1196 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "checkgetrangefunc set to %s",
1197 GST_DEBUG_FUNCPTR_NAME (check));
1201 * gst_pad_set_event_function:
1202 * @pad: a source #GstPad.
1203 * @event: the #GstPadEventFunction to set.
1205 * Sets the given event handler for the pad.
1208 gst_pad_set_event_function (GstPad * pad, GstPadEventFunction event)
1210 g_return_if_fail (GST_IS_PAD (pad));
1212 GST_PAD_EVENTFUNC (pad) = event;
1214 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "eventfunc for set to %s",
1215 GST_DEBUG_FUNCPTR_NAME (event));
1219 * gst_pad_set_query_function:
1220 * @pad: a #GstPad of either direction.
1221 * @query: the #GstPadQueryFunction to set.
1223 * Set the given query function for the pad.
1226 gst_pad_set_query_function (GstPad * pad, GstPadQueryFunction query)
1228 g_return_if_fail (GST_IS_PAD (pad));
1230 GST_PAD_QUERYFUNC (pad) = query;
1232 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "queryfunc set to %s",
1233 GST_DEBUG_FUNCPTR_NAME (query));
1237 * gst_pad_set_query_type_function:
1238 * @pad: a #GstPad of either direction.
1239 * @type_func: the #GstPadQueryTypeFunction to set.
1241 * Set the given query type function for the pad.
1244 gst_pad_set_query_type_function (GstPad * pad,
1245 GstPadQueryTypeFunction type_func)
1247 g_return_if_fail (GST_IS_PAD (pad));
1249 GST_PAD_QUERYTYPEFUNC (pad) = type_func;
1251 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "querytypefunc set to %s",
1252 GST_DEBUG_FUNCPTR_NAME (type_func));
1256 * gst_pad_get_query_types:
1259 * Get an array of supported queries that can be performed
1262 * Returns: a zero-terminated array of #GstQueryType.
1264 const GstQueryType *
1265 gst_pad_get_query_types (GstPad * pad)
1267 GstPadQueryTypeFunction func;
1269 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
1271 if (G_UNLIKELY ((func = GST_PAD_QUERYTYPEFUNC (pad)) == NULL))
1283 gst_pad_get_query_types_dispatcher (GstPad * pad, const GstQueryType ** data)
1285 *data = gst_pad_get_query_types (pad);
1291 * gst_pad_get_query_types_default:
1294 * Invoke the default dispatcher for the query types on
1297 * Returns: an zero-terminated array of #GstQueryType, or NULL if none of the
1298 * internally-linked pads has a query types function.
1300 const GstQueryType *
1301 gst_pad_get_query_types_default (GstPad * pad)
1303 GstQueryType *result = NULL;
1305 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
1307 gst_pad_dispatcher (pad, (GstPadDispatcherFunction)
1308 gst_pad_get_query_types_dispatcher, &result);
1314 * gst_pad_set_internal_link_function:
1315 * @pad: a #GstPad of either direction.
1316 * @intlink: the #GstPadIntLinkFunction to set.
1318 * Sets the given internal link function for the pad.
1321 gst_pad_set_internal_link_function (GstPad * pad, GstPadIntLinkFunction intlink)
1323 g_return_if_fail (GST_IS_PAD (pad));
1325 GST_PAD_INTLINKFUNC (pad) = intlink;
1326 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "internal link set to %s",
1327 GST_DEBUG_FUNCPTR_NAME (intlink));
1331 * gst_pad_set_link_function:
1333 * @link: the #GstPadLinkFunction to set.
1335 * Sets the given link function for the pad. It will be called when
1336 * the pad is linked with another pad.
1338 * The return value #GST_PAD_LINK_OK should be used when the connection can be
1341 * The return value #GST_PAD_LINK_REFUSED should be used when the connection
1342 * cannot be made for some reason.
1344 * If @link is installed on a source pad, it should call the #GstPadLinkFunction
1345 * of the peer sink pad, if present.
1348 gst_pad_set_link_function (GstPad * pad, GstPadLinkFunction link)
1350 g_return_if_fail (GST_IS_PAD (pad));
1352 GST_PAD_LINKFUNC (pad) = link;
1353 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "linkfunc set to %s",
1354 GST_DEBUG_FUNCPTR_NAME (link));
1358 * gst_pad_set_unlink_function:
1360 * @unlink: the #GstPadUnlinkFunction to set.
1362 * Sets the given unlink function for the pad. It will be called
1363 * when the pad is unlinked.
1366 gst_pad_set_unlink_function (GstPad * pad, GstPadUnlinkFunction unlink)
1368 g_return_if_fail (GST_IS_PAD (pad));
1370 GST_PAD_UNLINKFUNC (pad) = unlink;
1371 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "unlinkfunc set to %s",
1372 GST_DEBUG_FUNCPTR_NAME (unlink));
1376 * gst_pad_set_getcaps_function:
1378 * @getcaps: the #GstPadGetCapsFunction to set.
1380 * Sets the given getcaps function for the pad. @getcaps should return the
1381 * allowable caps for a pad in the context of the element's state, its link to
1382 * other elements, and the devices or files it has opened. These caps must be a
1383 * subset of the pad template caps. In the NULL state with no links, @getcaps
1384 * should ideally return the same caps as the pad template. In rare
1385 * circumstances, an object property can affect the caps returned by @getcaps,
1386 * but this is discouraged.
1388 * You do not need to call this function if @pad's allowed caps are always the
1389 * same as the pad template caps. This can only be true if the padtemplate
1390 * has fixed simple caps.
1392 * For most filters, the caps returned by @getcaps is directly affected by the
1393 * allowed caps on other pads. For demuxers and decoders, the caps returned by
1394 * the srcpad's getcaps function is directly related to the stream data. Again,
1395 * @getcaps should return the most specific caps it reasonably can, since this
1396 * helps with autoplugging.
1398 * Note that the return value from @getcaps is owned by the caller, so the caller
1399 * should unref the caps after usage.
1402 gst_pad_set_getcaps_function (GstPad * pad, GstPadGetCapsFunction getcaps)
1404 g_return_if_fail (GST_IS_PAD (pad));
1406 GST_PAD_GETCAPSFUNC (pad) = getcaps;
1407 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "getcapsfunc set to %s",
1408 GST_DEBUG_FUNCPTR_NAME (getcaps));
1412 * gst_pad_set_acceptcaps_function:
1414 * @acceptcaps: the #GstPadAcceptCapsFunction to set.
1416 * Sets the given acceptcaps function for the pad. The acceptcaps function
1417 * will be called to check if the pad can accept the given caps. Setting the
1418 * acceptcaps function to NULL restores the default behaviour of allowing
1419 * any caps that matches the caps from gst_pad_get_caps.
1422 gst_pad_set_acceptcaps_function (GstPad * pad,
1423 GstPadAcceptCapsFunction acceptcaps)
1425 g_return_if_fail (GST_IS_PAD (pad));
1427 GST_PAD_ACCEPTCAPSFUNC (pad) = acceptcaps;
1428 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "acceptcapsfunc set to %s",
1429 GST_DEBUG_FUNCPTR_NAME (acceptcaps));
1433 * gst_pad_set_fixatecaps_function:
1435 * @fixatecaps: the #GstPadFixateCapsFunction to set.
1437 * Sets the given fixatecaps function for the pad. The fixatecaps function
1438 * will be called whenever the default values for a GstCaps needs to be
1442 gst_pad_set_fixatecaps_function (GstPad * pad,
1443 GstPadFixateCapsFunction fixatecaps)
1445 g_return_if_fail (GST_IS_PAD (pad));
1447 GST_PAD_FIXATECAPSFUNC (pad) = fixatecaps;
1448 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "fixatecapsfunc set to %s",
1449 GST_DEBUG_FUNCPTR_NAME (fixatecaps));
1453 * gst_pad_set_setcaps_function:
1455 * @setcaps: the #GstPadSetCapsFunction to set.
1457 * Sets the given setcaps function for the pad. The setcaps function
1458 * will be called whenever a buffer with a new media type is pushed or
1459 * pulled from the pad. The pad/element needs to update its internal
1460 * structures to process the new media type. If this new type is not
1461 * acceptable, the setcaps function should return FALSE.
1464 gst_pad_set_setcaps_function (GstPad * pad, GstPadSetCapsFunction setcaps)
1466 g_return_if_fail (GST_IS_PAD (pad));
1468 GST_PAD_SETCAPSFUNC (pad) = setcaps;
1469 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "setcapsfunc set to %s",
1470 GST_DEBUG_FUNCPTR_NAME (setcaps));
1474 * gst_pad_set_bufferalloc_function:
1475 * @pad: a sink #GstPad.
1476 * @bufalloc: the #GstPadBufferAllocFunction to set.
1478 * Sets the given bufferalloc function for the pad. Note that the
1479 * bufferalloc function can only be set on sinkpads.
1482 gst_pad_set_bufferalloc_function (GstPad * pad,
1483 GstPadBufferAllocFunction bufalloc)
1485 g_return_if_fail (GST_IS_PAD (pad));
1486 g_return_if_fail (GST_PAD_IS_SINK (pad));
1488 GST_PAD_BUFFERALLOCFUNC (pad) = bufalloc;
1489 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "bufferallocfunc set to %s",
1490 GST_DEBUG_FUNCPTR_NAME (bufalloc));
1495 * @srcpad: the source #GstPad to unlink.
1496 * @sinkpad: the sink #GstPad to unlink.
1498 * Unlinks the source pad from the sink pad. Will emit the "unlinked" signal on
1501 * Returns: TRUE if the pads were unlinked. This function returns FALSE if
1502 * the pads were not linked together.
1507 gst_pad_unlink (GstPad * srcpad, GstPad * sinkpad)
1509 g_return_val_if_fail (GST_IS_PAD (srcpad), FALSE);
1510 g_return_val_if_fail (GST_IS_PAD (sinkpad), FALSE);
1512 GST_CAT_INFO (GST_CAT_ELEMENT_PADS, "unlinking %s:%s(%p) and %s:%s(%p)",
1513 GST_DEBUG_PAD_NAME (srcpad), srcpad,
1514 GST_DEBUG_PAD_NAME (sinkpad), sinkpad);
1516 GST_OBJECT_LOCK (srcpad);
1518 if (G_UNLIKELY (GST_PAD_DIRECTION (srcpad) != GST_PAD_SRC))
1521 GST_OBJECT_LOCK (sinkpad);
1523 if (G_UNLIKELY (GST_PAD_DIRECTION (sinkpad) != GST_PAD_SINK))
1526 if (G_UNLIKELY (GST_PAD_PEER (srcpad) != sinkpad))
1527 goto not_linked_together;
1529 if (GST_PAD_UNLINKFUNC (srcpad)) {
1530 GST_PAD_UNLINKFUNC (srcpad) (srcpad);
1532 if (GST_PAD_UNLINKFUNC (sinkpad)) {
1533 GST_PAD_UNLINKFUNC (sinkpad) (sinkpad);
1536 /* first clear peers */
1537 GST_PAD_PEER (srcpad) = NULL;
1538 GST_PAD_PEER (sinkpad) = NULL;
1540 GST_OBJECT_UNLOCK (sinkpad);
1541 GST_OBJECT_UNLOCK (srcpad);
1543 /* fire off a signal to each of the pads telling them
1544 * that they've been unlinked */
1545 g_signal_emit (G_OBJECT (srcpad), gst_pad_signals[PAD_UNLINKED], 0, sinkpad);
1546 g_signal_emit (G_OBJECT (sinkpad), gst_pad_signals[PAD_UNLINKED], 0, srcpad);
1548 GST_CAT_INFO (GST_CAT_ELEMENT_PADS, "unlinked %s:%s and %s:%s",
1549 GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (sinkpad));
1555 g_critical ("pad %s is not a source pad", GST_PAD_NAME (srcpad));
1556 GST_OBJECT_UNLOCK (srcpad);
1561 g_critical ("pad %s is not a sink pad", GST_PAD_NAME (sinkpad));
1562 GST_OBJECT_UNLOCK (sinkpad);
1563 GST_OBJECT_UNLOCK (srcpad);
1566 not_linked_together:
1568 /* we do not emit a warning in this case because unlinking cannot
1569 * be made MT safe.*/
1570 GST_OBJECT_UNLOCK (sinkpad);
1571 GST_OBJECT_UNLOCK (srcpad);
1577 * gst_pad_is_linked:
1578 * @pad: pad to check
1580 * Checks if a @pad is linked to another pad or not.
1582 * Returns: TRUE if the pad is linked, FALSE otherwise.
1587 gst_pad_is_linked (GstPad * pad)
1591 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
1593 GST_OBJECT_LOCK (pad);
1594 result = (GST_PAD_PEER (pad) != NULL);
1595 GST_OBJECT_UNLOCK (pad);
1600 /* get the caps from both pads and see if the intersection
1603 * This function should be called with the pad LOCK on both
1607 gst_pad_link_check_compatible_unlocked (GstPad * src, GstPad * sink)
1613 srccaps = gst_pad_get_caps_unlocked (src);
1614 sinkcaps = gst_pad_get_caps_unlocked (sink);
1616 GST_CAT_DEBUG (GST_CAT_CAPS, "src caps %" GST_PTR_FORMAT, srccaps);
1617 GST_CAT_DEBUG (GST_CAT_CAPS, "sink caps %" GST_PTR_FORMAT, sinkcaps);
1619 /* if we have caps on both pads we can check the intersection. If one
1620 * of the caps is NULL, we return TRUE. */
1621 if (srccaps == NULL || sinkcaps == NULL)
1624 icaps = gst_caps_intersect (srccaps, sinkcaps);
1625 gst_caps_unref (srccaps);
1626 gst_caps_unref (sinkcaps);
1631 GST_CAT_DEBUG (GST_CAT_CAPS,
1632 "intersection caps %p %" GST_PTR_FORMAT, icaps, icaps);
1634 if (gst_caps_is_empty (icaps))
1637 gst_caps_unref (icaps);
1642 /* incompatible cases */
1645 GST_CAT_DEBUG (GST_CAT_CAPS, "intersection gave NULL");
1650 GST_CAT_DEBUG (GST_CAT_CAPS, "intersection is EMPTY");
1651 gst_caps_unref (icaps);
1656 /* check if the grandparents of both pads are the same.
1657 * This check is required so that we don't try to link
1658 * pads from elements in different bins without ghostpads.
1660 * The LOCK should be held on both pads
1663 gst_pad_link_check_hierarchy (GstPad * src, GstPad * sink)
1665 GstObject *psrc, *psink;
1667 psrc = GST_OBJECT_PARENT (src);
1668 psink = GST_OBJECT_PARENT (sink);
1670 /* if one of the pads has no parent, we allow the link */
1671 if (G_UNLIKELY (psrc == NULL || psink == NULL))
1674 /* if the parents are the same, we have a loop */
1675 if (G_UNLIKELY (psrc == psink))
1678 /* if they both have a parent, we check the grandparents. We can not lock
1679 * the parent because we hold on the child (pad) and the locking order is
1680 * parent >> child. */
1681 psrc = GST_OBJECT_PARENT (psrc);
1682 psink = GST_OBJECT_PARENT (psink);
1684 /* if they have grandparents but they are not the same */
1685 if (G_UNLIKELY (psrc != psink))
1686 goto wrong_grandparents;
1693 GST_CAT_DEBUG (GST_CAT_CAPS,
1694 "one of the pads has no parent %" GST_PTR_FORMAT " and %"
1695 GST_PTR_FORMAT, psrc, psink);
1700 GST_CAT_DEBUG (GST_CAT_CAPS, "pads have same parent %" GST_PTR_FORMAT,
1706 GST_CAT_DEBUG (GST_CAT_CAPS,
1707 "pads have different grandparents %" GST_PTR_FORMAT " and %"
1708 GST_PTR_FORMAT, psrc, psink);
1713 /* FIXME leftover from an attempt at refactoring... */
1714 /* call with the two pads unlocked, when this function returns GST_PAD_LINK_OK,
1715 * the two pads will be locked in the srcpad, sinkpad order. */
1716 static GstPadLinkReturn
1717 gst_pad_link_prepare (GstPad * srcpad, GstPad * sinkpad)
1719 /* generic checks */
1720 g_return_val_if_fail (GST_IS_PAD (srcpad), GST_PAD_LINK_REFUSED);
1721 g_return_val_if_fail (GST_IS_PAD (sinkpad), GST_PAD_LINK_REFUSED);
1723 GST_CAT_INFO (GST_CAT_PADS, "trying to link %s:%s and %s:%s",
1724 GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (sinkpad));
1726 GST_OBJECT_LOCK (srcpad);
1728 if (G_UNLIKELY (GST_PAD_DIRECTION (srcpad) != GST_PAD_SRC))
1731 if (G_UNLIKELY (GST_PAD_PEER (srcpad) != NULL))
1732 goto src_was_linked;
1734 GST_OBJECT_LOCK (sinkpad);
1736 if (G_UNLIKELY (GST_PAD_DIRECTION (sinkpad) != GST_PAD_SINK))
1739 if (G_UNLIKELY (GST_PAD_PEER (sinkpad) != NULL))
1740 goto sink_was_linked;
1742 /* check hierarchy, pads can only be linked if the grandparents
1744 if (!gst_pad_link_check_hierarchy (srcpad, sinkpad))
1745 goto wrong_hierarchy;
1747 /* check pad caps for non-empty intersection */
1748 if (!gst_pad_link_check_compatible_unlocked (srcpad, sinkpad))
1751 /* FIXME check pad scheduling for non-empty intersection */
1753 return GST_PAD_LINK_OK;
1757 g_critical ("pad %s is not a source pad", GST_PAD_NAME (srcpad));
1758 GST_OBJECT_UNLOCK (srcpad);
1759 return GST_PAD_LINK_WRONG_DIRECTION;
1763 GST_CAT_INFO (GST_CAT_PADS, "src %s:%s was already linked to %s:%s",
1764 GST_DEBUG_PAD_NAME (srcpad),
1765 GST_DEBUG_PAD_NAME (GST_PAD_PEER (srcpad)));
1766 /* we do not emit a warning in this case because unlinking cannot
1767 * be made MT safe.*/
1768 GST_OBJECT_UNLOCK (srcpad);
1769 return GST_PAD_LINK_WAS_LINKED;
1773 g_critical ("pad %s is not a sink pad", GST_PAD_NAME (sinkpad));
1774 GST_OBJECT_UNLOCK (sinkpad);
1775 GST_OBJECT_UNLOCK (srcpad);
1776 return GST_PAD_LINK_WRONG_DIRECTION;
1780 GST_CAT_INFO (GST_CAT_PADS, "sink %s:%s was already linked to %s:%s",
1781 GST_DEBUG_PAD_NAME (sinkpad),
1782 GST_DEBUG_PAD_NAME (GST_PAD_PEER (sinkpad)));
1783 /* we do not emit a warning in this case because unlinking cannot
1784 * be made MT safe.*/
1785 GST_OBJECT_UNLOCK (sinkpad);
1786 GST_OBJECT_UNLOCK (srcpad);
1787 return GST_PAD_LINK_WAS_LINKED;
1791 GST_CAT_INFO (GST_CAT_PADS, "pads have wrong hierarchy");
1792 GST_OBJECT_UNLOCK (sinkpad);
1793 GST_OBJECT_UNLOCK (srcpad);
1794 return GST_PAD_LINK_WRONG_HIERARCHY;
1798 GST_CAT_INFO (GST_CAT_PADS, "caps are incompatible");
1799 GST_OBJECT_UNLOCK (sinkpad);
1800 GST_OBJECT_UNLOCK (srcpad);
1801 return GST_PAD_LINK_NOFORMAT;
1807 * @srcpad: the source #GstPad to link.
1808 * @sinkpad: the sink #GstPad to link.
1810 * Links the source pad and the sink pad.
1812 * Returns: A result code indicating if the connection worked or
1818 gst_pad_link (GstPad * srcpad, GstPad * sinkpad)
1820 GstPadLinkReturn result;
1822 /* prepare will also lock the two pads */
1823 result = gst_pad_link_prepare (srcpad, sinkpad);
1825 if (result != GST_PAD_LINK_OK)
1826 goto prepare_failed;
1828 /* must set peers before calling the link function */
1829 GST_PAD_PEER (srcpad) = sinkpad;
1830 GST_PAD_PEER (sinkpad) = srcpad;
1832 GST_OBJECT_UNLOCK (sinkpad);
1833 GST_OBJECT_UNLOCK (srcpad);
1835 /* FIXME released the locks here, concurrent thread might link
1836 * something else. */
1837 if (GST_PAD_LINKFUNC (srcpad)) {
1838 /* this one will call the peer link function */
1839 result = GST_PAD_LINKFUNC (srcpad) (srcpad, sinkpad);
1840 } else if (GST_PAD_LINKFUNC (sinkpad)) {
1841 /* if no source link function, we need to call the sink link
1842 * function ourselves. */
1843 result = GST_PAD_LINKFUNC (sinkpad) (sinkpad, srcpad);
1845 result = GST_PAD_LINK_OK;
1848 GST_OBJECT_LOCK (srcpad);
1849 GST_OBJECT_LOCK (sinkpad);
1851 if (result == GST_PAD_LINK_OK) {
1852 GST_OBJECT_UNLOCK (sinkpad);
1853 GST_OBJECT_UNLOCK (srcpad);
1855 /* fire off a signal to each of the pads telling them
1856 * that they've been linked */
1857 g_signal_emit (G_OBJECT (srcpad), gst_pad_signals[PAD_LINKED], 0, sinkpad);
1858 g_signal_emit (G_OBJECT (sinkpad), gst_pad_signals[PAD_LINKED], 0, srcpad);
1860 GST_CAT_INFO (GST_CAT_PADS, "linked %s:%s and %s:%s, successful",
1861 GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (sinkpad));
1863 GST_CAT_INFO (GST_CAT_PADS, "link between %s:%s and %s:%s failed",
1864 GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (sinkpad));
1866 GST_PAD_PEER (srcpad) = NULL;
1867 GST_PAD_PEER (sinkpad) = NULL;
1869 GST_OBJECT_UNLOCK (sinkpad);
1870 GST_OBJECT_UNLOCK (srcpad);
1881 gst_pad_set_pad_template (GstPad * pad, GstPadTemplate * templ)
1883 GstPadTemplate **template_p;
1885 /* this function would need checks if it weren't static */
1887 GST_OBJECT_LOCK (pad);
1888 template_p = &pad->padtemplate;
1889 gst_object_replace ((GstObject **) template_p, (GstObject *) templ);
1890 GST_OBJECT_UNLOCK (pad);
1893 gst_pad_template_pad_created (templ, pad);
1897 * gst_pad_get_pad_template:
1900 * Gets the template for @pad.
1902 * Returns: the #GstPadTemplate from which this pad was instantiated, or %NULL
1903 * if this pad has no template.
1905 * FIXME: currently returns an unrefcounted padtemplate.
1908 gst_pad_get_pad_template (GstPad * pad)
1910 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
1912 return GST_PAD_PAD_TEMPLATE (pad);
1916 /* should be called with the pad LOCK held */
1917 /* refs the caps, so caller is responsible for getting it unreffed */
1919 gst_pad_get_caps_unlocked (GstPad * pad)
1921 GstCaps *result = NULL;
1923 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "get pad caps");
1925 if (GST_PAD_GETCAPSFUNC (pad)) {
1926 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
1927 "dispatching to pad getcaps function");
1929 GST_OBJECT_FLAG_SET (pad, GST_PAD_IN_GETCAPS);
1930 GST_OBJECT_UNLOCK (pad);
1931 result = GST_PAD_GETCAPSFUNC (pad) (pad);
1932 GST_OBJECT_LOCK (pad);
1933 GST_OBJECT_FLAG_UNSET (pad, GST_PAD_IN_GETCAPS);
1935 if (result == NULL) {
1936 g_critical ("pad %s:%s returned NULL caps from getcaps function",
1937 GST_DEBUG_PAD_NAME (pad));
1939 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
1940 "pad getcaps returned %" GST_PTR_FORMAT, result);
1941 #ifndef G_DISABLE_ASSERT
1942 /* check that the returned caps are a real subset of the template caps */
1943 if (GST_PAD_PAD_TEMPLATE (pad)) {
1944 const GstCaps *templ_caps =
1945 GST_PAD_TEMPLATE_CAPS (GST_PAD_PAD_TEMPLATE (pad));
1946 if (!gst_caps_is_subset (result, templ_caps)) {
1949 GST_CAT_ERROR_OBJECT (GST_CAT_CAPS, pad,
1950 "pad returned caps %" GST_PTR_FORMAT
1951 " which are not a real subset of its template caps %"
1952 GST_PTR_FORMAT, result, templ_caps);
1954 ("pad %s:%s returned caps which are not a real "
1955 "subset of its template caps", GST_DEBUG_PAD_NAME (pad));
1956 temp = gst_caps_intersect (templ_caps, result);
1957 gst_caps_unref (result);
1965 if (GST_PAD_PAD_TEMPLATE (pad)) {
1966 GstPadTemplate *templ = GST_PAD_PAD_TEMPLATE (pad);
1968 result = GST_PAD_TEMPLATE_CAPS (templ);
1969 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
1970 "using pad template %p with caps %p %" GST_PTR_FORMAT, templ, result,
1973 result = gst_caps_ref (result);
1976 if (GST_PAD_CAPS (pad)) {
1977 result = GST_PAD_CAPS (pad);
1979 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
1980 "using pad caps %p %" GST_PTR_FORMAT, result, result);
1982 result = gst_caps_ref (result);
1986 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "pad has no caps");
1987 result = gst_caps_new_empty ();
1995 * @pad: a #GstPad to get the capabilities of.
1997 * Gets the capabilities this pad can produce or consume.
1998 * Note that this method doesn't necessarily return the caps set by
1999 * gst_pad_set_caps() - use #GST_PAD_CAPS for that instead.
2000 * gst_pad_get_caps returns all possible caps a pad can operate with, using
2001 * the pad's get_caps function;
2002 * this returns the pad template caps if not explicitly set.
2004 * Returns: a newly allocated copy of the #GstCaps of this pad.
2009 gst_pad_get_caps (GstPad * pad)
2011 GstCaps *result = NULL;
2013 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2015 GST_OBJECT_LOCK (pad);
2017 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "get pad caps");
2019 result = gst_pad_get_caps_unlocked (pad);
2020 GST_OBJECT_UNLOCK (pad);
2026 * gst_pad_peer_get_caps:
2027 * @pad: a #GstPad to get the peer capabilities of.
2029 * Gets the capabilities of the peer connected to this pad.
2031 * Returns: the #GstCaps of the peer pad. This function returns a new caps, so use
2032 * gst_caps_unref to get rid of it. this function returns NULL if there is no
2036 gst_pad_peer_get_caps (GstPad * pad)
2039 GstCaps *result = NULL;
2041 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2043 GST_OBJECT_LOCK (pad);
2045 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "get peer caps");
2047 peerpad = GST_PAD_PEER (pad);
2048 if (G_UNLIKELY (peerpad == NULL))
2051 gst_object_ref (peerpad);
2052 GST_OBJECT_UNLOCK (pad);
2054 result = gst_pad_get_caps (peerpad);
2056 gst_object_unref (peerpad);
2062 GST_OBJECT_UNLOCK (pad);
2068 fixate_value (GValue * dest, const GValue * src)
2070 if (G_VALUE_TYPE (src) == GST_TYPE_INT_RANGE) {
2071 g_value_init (dest, G_TYPE_INT);
2072 g_value_set_int (dest, gst_value_get_int_range_min (src));
2073 } else if (G_VALUE_TYPE (src) == GST_TYPE_DOUBLE_RANGE) {
2074 g_value_init (dest, G_TYPE_DOUBLE);
2075 g_value_set_double (dest, gst_value_get_double_range_min (src));
2076 } else if (G_VALUE_TYPE (src) == GST_TYPE_FRACTION_RANGE) {
2077 gst_value_init_and_copy (dest, gst_value_get_fraction_range_min (src));
2078 } else if (G_VALUE_TYPE (src) == GST_TYPE_LIST) {
2079 GValue temp = { 0 };
2081 gst_value_init_and_copy (&temp, gst_value_list_get_value (src, 0));
2082 if (!fixate_value (dest, &temp))
2083 gst_value_init_and_copy (dest, &temp);
2084 g_value_unset (&temp);
2085 } else if (G_VALUE_TYPE (src) == GST_TYPE_ARRAY) {
2086 gboolean res = FALSE;
2089 g_value_init (dest, GST_TYPE_ARRAY);
2090 for (n = 0; n < gst_value_array_get_size (src); n++) {
2092 const GValue *orig_kid = gst_value_array_get_value (src, n);
2094 if (!fixate_value (&kid, orig_kid))
2095 gst_value_init_and_copy (&kid, orig_kid);
2098 gst_value_array_append_value (dest, &kid);
2099 g_value_unset (&kid);
2103 g_value_unset (dest);
2114 gst_pad_default_fixate (GQuark field_id, const GValue * value, gpointer data)
2116 GstStructure *s = data;
2119 if (fixate_value (&v, value)) {
2120 gst_structure_id_set_value (s, field_id, &v);
2128 * gst_pad_fixate_caps:
2129 * @pad: a #GstPad to fixate
2130 * @caps: the #GstCaps to fixate
2132 * Fixate a caps on the given pad. Modifies the caps in place, so you should
2133 * make sure that the caps are actually writable (see gst_caps_make_writable()).
2136 gst_pad_fixate_caps (GstPad * pad, GstCaps * caps)
2138 GstPadFixateCapsFunction fixatefunc;
2141 g_return_if_fail (GST_IS_PAD (pad));
2142 g_return_if_fail (caps != NULL);
2144 if (gst_caps_is_fixed (caps))
2147 fixatefunc = GST_PAD_FIXATECAPSFUNC (pad);
2149 fixatefunc (pad, caps);
2152 /* default fixation */
2153 for (n = 0; n < gst_caps_get_size (caps); n++) {
2154 GstStructure *s = gst_caps_get_structure (caps, n);
2156 gst_structure_foreach (s, gst_pad_default_fixate, s);
2160 /* Default accept caps implementation just checks against
2161 * against the allowed caps for the pad */
2163 gst_pad_acceptcaps_default (GstPad * pad, GstCaps * caps)
2165 /* get the caps and see if it intersects to something
2169 gboolean result = FALSE;
2171 allowed = gst_pad_get_caps (pad);
2173 intersect = gst_caps_intersect (allowed, caps);
2175 result = !gst_caps_is_empty (intersect);
2177 gst_caps_unref (allowed);
2178 gst_caps_unref (intersect);
2185 * gst_pad_accept_caps:
2186 * @pad: a #GstPad to check
2187 * @caps: a #GstCaps to check on the pad
2189 * Check if the given pad accepts the caps.
2191 * Returns: TRUE if the pad can accept the caps.
2194 gst_pad_accept_caps (GstPad * pad, GstCaps * caps)
2197 GstPadAcceptCapsFunction acceptfunc;
2198 GstCaps *existing = NULL;
2200 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2202 /* any pad can be unnegotiated */
2206 /* lock for checking the existing caps */
2207 GST_OBJECT_LOCK (pad);
2208 acceptfunc = GST_PAD_ACCEPTCAPSFUNC (pad);
2209 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "accept caps of %p", caps);
2210 /* The current caps on a pad are trivially acceptable */
2211 if (G_LIKELY ((existing = GST_PAD_CAPS (pad)))) {
2212 if (caps == existing || gst_caps_is_equal (caps, existing))
2215 GST_OBJECT_UNLOCK (pad);
2217 if (G_LIKELY (acceptfunc)) {
2218 /* we can call the function */
2219 result = acceptfunc (pad, caps);
2221 /* Only null if the element explicitly unset it */
2222 result = gst_pad_acceptcaps_default (pad, caps);
2228 GST_OBJECT_UNLOCK (pad);
2234 * gst_pad_peer_accept_caps:
2235 * @pad: a #GstPad to check the peer of
2236 * @caps: a #GstCaps to check on the pad
2238 * Check if the peer of @pad accepts @caps. If @pad has no peer, this function
2241 * Returns: TRUE if the peer of @pad can accept the caps or @pad has no peer.
2244 gst_pad_peer_accept_caps (GstPad * pad, GstCaps * caps)
2249 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2251 GST_OBJECT_LOCK (pad);
2253 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "peer accept caps of (%p)", pad);
2255 peerpad = GST_PAD_PEER (pad);
2256 if (G_UNLIKELY (peerpad == NULL))
2259 result = gst_pad_accept_caps (peerpad, caps);
2260 GST_OBJECT_UNLOCK (pad);
2266 GST_OBJECT_UNLOCK (pad);
2273 * @pad: a #GstPad to set the capabilities of.
2274 * @caps: a #GstCaps to set.
2276 * Sets the capabilities of this pad. The caps must be fixed. Any previous
2277 * caps on the pad will be unreffed. This function refs the caps so you should
2278 * unref if as soon as you don't need it anymore.
2279 * It is possible to set NULL caps, which will make the pad unnegotiated
2282 * Returns: TRUE if the caps could be set. FALSE if the caps were not fixed
2283 * or bad parameters were provided to this function.
2288 gst_pad_set_caps (GstPad * pad, GstCaps * caps)
2290 GstPadSetCapsFunction setcaps;
2293 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2294 g_return_val_if_fail (caps == NULL || gst_caps_is_fixed (caps), FALSE);
2296 GST_OBJECT_LOCK (pad);
2297 existing = GST_PAD_CAPS (pad);
2298 if (existing == caps)
2301 if (gst_caps_is_equal (caps, existing))
2302 goto setting_same_caps;
2304 setcaps = GST_PAD_SETCAPSFUNC (pad);
2306 /* call setcaps function to configure the pad only if the
2307 * caps is not NULL */
2308 if (setcaps != NULL && caps) {
2309 if (!GST_PAD_IS_IN_SETCAPS (pad)) {
2310 GST_OBJECT_FLAG_SET (pad, GST_PAD_IN_SETCAPS);
2311 GST_OBJECT_UNLOCK (pad);
2312 if (!setcaps (pad, caps))
2314 GST_OBJECT_LOCK (pad);
2315 GST_OBJECT_FLAG_UNSET (pad, GST_PAD_IN_SETCAPS);
2317 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "pad was dispatching");
2321 gst_caps_replace (&GST_PAD_CAPS (pad), caps);
2322 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "caps %" GST_PTR_FORMAT, caps);
2323 GST_OBJECT_UNLOCK (pad);
2325 g_object_notify (G_OBJECT (pad), "caps");
2331 GST_OBJECT_UNLOCK (pad);
2336 gst_caps_replace (&GST_PAD_CAPS (pad), caps);
2337 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
2338 "caps %" GST_PTR_FORMAT " same as existing, updating ptr only", caps);
2339 GST_OBJECT_UNLOCK (pad);
2346 GST_OBJECT_LOCK (pad);
2347 GST_OBJECT_FLAG_UNSET (pad, GST_PAD_IN_SETCAPS);
2348 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
2349 "caps %" GST_PTR_FORMAT " could not be set", caps);
2350 GST_OBJECT_UNLOCK (pad);
2357 gst_pad_configure_sink (GstPad * pad, GstCaps * caps)
2359 GstPadSetCapsFunction setcaps;
2362 setcaps = GST_PAD_SETCAPSFUNC (pad);
2364 /* See if pad accepts the caps - only needed if
2365 * no setcaps function */
2366 if (setcaps == NULL)
2367 if (!gst_pad_accept_caps (pad, caps))
2370 /* set caps on pad if call succeeds */
2371 res = gst_pad_set_caps (pad, caps);
2372 /* no need to unref the caps here, set_caps takes a ref and
2373 * our ref goes away when we leave this function. */
2379 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
2380 "caps %" GST_PTR_FORMAT " not accepted", caps);
2385 /* returns TRUE if the src pad could be configured to accept the given caps */
2387 gst_pad_configure_src (GstPad * pad, GstCaps * caps, gboolean dosetcaps)
2389 GstPadSetCapsFunction setcaps;
2392 setcaps = GST_PAD_SETCAPSFUNC (pad);
2394 /* See if pad accepts the caps - only needed if
2395 * no setcaps function */
2396 if (setcaps == NULL)
2397 if (!gst_pad_accept_caps (pad, caps))
2401 res = gst_pad_set_caps (pad, caps);
2409 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
2410 "caps %" GST_PTR_FORMAT " not accepted", caps);
2416 * gst_pad_get_pad_template_caps:
2417 * @pad: a #GstPad to get the template capabilities from.
2419 * Gets the capabilities for @pad's template.
2421 * Returns: the #GstCaps of this pad template. If you intend to keep a reference
2422 * on the caps, make a copy (see gst_caps_copy ()).
2425 gst_pad_get_pad_template_caps (GstPad * pad)
2427 static GstStaticCaps anycaps = GST_STATIC_CAPS ("ANY");
2429 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2431 if (GST_PAD_PAD_TEMPLATE (pad))
2432 return GST_PAD_TEMPLATE_CAPS (GST_PAD_PAD_TEMPLATE (pad));
2434 return gst_static_caps_get (&anycaps);
2440 * @pad: a #GstPad to get the peer of.
2442 * Gets the peer of @pad. This function refs the peer pad so
2443 * you need to unref it after use.
2445 * Returns: the peer #GstPad. Unref after usage.
2450 gst_pad_get_peer (GstPad * pad)
2454 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2456 GST_OBJECT_LOCK (pad);
2457 result = GST_PAD_PEER (pad);
2459 gst_object_ref (result);
2460 GST_OBJECT_UNLOCK (pad);
2466 * gst_pad_get_allowed_caps:
2467 * @srcpad: a #GstPad, it must a a source pad.
2469 * Gets the capabilities of the allowed media types that can flow through
2470 * @srcpad and its peer. The pad must be a source pad.
2471 * The caller must free the resulting caps.
2473 * Returns: the allowed #GstCaps of the pad link. Free the caps when
2474 * you no longer need it. This function returns NULL when the @srcpad has no
2480 gst_pad_get_allowed_caps (GstPad * srcpad)
2487 g_return_val_if_fail (GST_IS_PAD (srcpad), NULL);
2488 g_return_val_if_fail (GST_PAD_IS_SRC (srcpad), NULL);
2490 GST_OBJECT_LOCK (srcpad);
2492 peer = GST_PAD_PEER (srcpad);
2493 if (G_UNLIKELY (peer == NULL))
2496 GST_CAT_DEBUG_OBJECT (GST_CAT_PROPERTIES, srcpad, "getting allowed caps");
2498 gst_object_ref (peer);
2499 GST_OBJECT_UNLOCK (srcpad);
2500 mycaps = gst_pad_get_caps (srcpad);
2502 peercaps = gst_pad_get_caps (peer);
2503 gst_object_unref (peer);
2505 caps = gst_caps_intersect (mycaps, peercaps);
2506 gst_caps_unref (peercaps);
2507 gst_caps_unref (mycaps);
2509 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, srcpad, "allowed caps %" GST_PTR_FORMAT,
2516 GST_CAT_DEBUG_OBJECT (GST_CAT_PROPERTIES, srcpad, "no peer");
2517 GST_OBJECT_UNLOCK (srcpad);
2524 * gst_pad_get_negotiated_caps:
2527 * Gets the capabilities of the media type that currently flows through @pad
2530 * This function can be used on both src and sinkpads. Note that srcpads are
2531 * always negotiated before sinkpads so it is possible that the negotiated caps
2532 * on the srcpad do not match the negotiated caps of the peer.
2534 * Returns: the negotiated #GstCaps of the pad link. Free the caps when
2535 * you no longer need it. This function returns NULL when the @pad has no
2536 * peer or is not negotiated yet.
2541 gst_pad_get_negotiated_caps (GstPad * pad)
2546 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2548 GST_OBJECT_LOCK (pad);
2550 if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
2553 GST_CAT_DEBUG_OBJECT (GST_CAT_PROPERTIES, pad, "getting negotiated caps");
2555 caps = GST_PAD_CAPS (pad);
2557 gst_caps_ref (caps);
2558 GST_OBJECT_UNLOCK (pad);
2560 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "negotiated caps %" GST_PTR_FORMAT,
2567 GST_CAT_DEBUG_OBJECT (GST_CAT_PROPERTIES, pad, "no peer");
2568 GST_OBJECT_UNLOCK (pad);
2574 /* calls the buffer_alloc function on the given pad */
2575 static GstFlowReturn
2576 gst_pad_buffer_alloc_unchecked (GstPad * pad, guint64 offset, gint size,
2577 GstCaps * caps, GstBuffer ** buf)
2580 GstPadBufferAllocFunction bufferallocfunc;
2582 GST_OBJECT_LOCK (pad);
2583 /* when the pad is flushing we cannot give a buffer */
2584 if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad)))
2587 bufferallocfunc = pad->bufferallocfunc;
2589 if (offset == GST_BUFFER_OFFSET_NONE) {
2590 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
2591 "calling bufferallocfunc &%s (@%p) for size %d offset NONE",
2592 GST_DEBUG_FUNCPTR_NAME (bufferallocfunc), bufferallocfunc, size);
2594 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
2595 "calling bufferallocfunc &%s (@%p) of for size %d offset %"
2596 G_GUINT64_FORMAT, GST_DEBUG_FUNCPTR_NAME (bufferallocfunc),
2597 bufferallocfunc, size, offset);
2599 GST_OBJECT_UNLOCK (pad);
2601 /* G_LIKELY for now since most elements don't implement a buffer alloc
2602 * function and there is no default alloc proxy function as this is usually
2604 if (G_LIKELY (bufferallocfunc == NULL))
2607 ret = bufferallocfunc (pad, offset, size, caps, buf);
2608 if (G_UNLIKELY (ret != GST_FLOW_OK))
2610 /* no error, but NULL buffer means fallback to the default */
2611 if (G_UNLIKELY (*buf == NULL))
2614 /* If the buffer alloc function didn't set up the caps like it should,
2616 if (G_UNLIKELY (caps && (GST_BUFFER_CAPS (*buf) == NULL))) {
2617 GST_WARNING_OBJECT (pad,
2618 "Buffer allocation function did not set caps. Setting");
2619 gst_buffer_set_caps (*buf, caps);
2625 /* pad was flushing */
2626 GST_OBJECT_UNLOCK (pad);
2627 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "pad was flushing");
2628 return GST_FLOW_WRONG_STATE;
2632 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
2633 "alloc function returned error (%d) %s", ret, gst_flow_get_name (ret));
2638 /* fallback case, allocate a buffer of our own, add pad caps. */
2639 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "fallback buffer alloc");
2641 *buf = gst_buffer_new_and_alloc (size);
2642 GST_BUFFER_OFFSET (*buf) = offset;
2643 gst_buffer_set_caps (*buf, caps);
2649 static GstFlowReturn
2650 gst_pad_alloc_buffer_full (GstPad * pad, guint64 offset, gint size,
2651 GstCaps * caps, GstBuffer ** buf, gboolean setcaps)
2655 gboolean caps_changed;
2657 g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
2658 g_return_val_if_fail (GST_PAD_IS_SRC (pad), GST_FLOW_ERROR);
2659 g_return_val_if_fail (buf != NULL, GST_FLOW_ERROR);
2661 GST_OBJECT_LOCK (pad);
2662 while (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad)))
2663 if ((ret = handle_pad_block (pad)) != GST_FLOW_OK)
2666 if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
2669 gst_object_ref (peer);
2670 GST_OBJECT_UNLOCK (pad);
2672 ret = gst_pad_buffer_alloc_unchecked (peer, offset, size, caps, buf);
2673 gst_object_unref (peer);
2675 if (G_UNLIKELY (ret != GST_FLOW_OK))
2678 /* FIXME, move capnego this into a base class? */
2679 caps = GST_BUFFER_CAPS (*buf);
2681 /* Lock for checking caps, pretty pointless as the _pad_push() function might
2682 * change it concurrently, one of the problems with automatic caps setting in
2683 * pad_alloc_and_set_caps. Worst case, if does a check too much, but only when
2684 * there is heavy renegotiation going on in both directions. */
2685 GST_OBJECT_LOCK (pad);
2686 caps_changed = caps && caps != GST_PAD_CAPS (pad);
2687 GST_OBJECT_UNLOCK (pad);
2689 /* we got a new datatype on the pad, see if it can handle it */
2690 if (G_UNLIKELY (caps_changed)) {
2691 GST_DEBUG_OBJECT (pad, "caps changed to %p %" GST_PTR_FORMAT, caps, caps);
2692 if (G_UNLIKELY (!gst_pad_configure_src (pad, caps, setcaps)))
2693 goto not_negotiated;
2699 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "pad block stopped by flush");
2700 GST_OBJECT_UNLOCK (pad);
2705 /* pad has no peer */
2706 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
2707 "called bufferallocfunc but had no peer");
2708 GST_OBJECT_UNLOCK (pad);
2709 return GST_FLOW_NOT_LINKED;
2713 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
2714 "alloc function returned error %s", gst_flow_get_name (ret));
2719 gst_buffer_unref (*buf);
2721 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
2722 "alloc function returned unacceptable buffer");
2723 return GST_FLOW_NOT_NEGOTIATED;
2728 * gst_pad_alloc_buffer:
2729 * @pad: a source #GstPad
2730 * @offset: the offset of the new buffer in the stream
2731 * @size: the size of the new buffer
2732 * @caps: the caps of the new buffer
2733 * @buf: a newly allocated buffer
2735 * Allocates a new, empty buffer optimized to push to pad @pad. This
2736 * function only works if @pad is a source pad and has a peer.
2738 * A new, empty #GstBuffer will be put in the @buf argument.
2739 * You need to check the caps of the buffer after performing this
2740 * function and renegotiate to the format if needed.
2742 * Returns: a result code indicating success of the operation. Any
2743 * result code other than #GST_FLOW_OK is an error and @buf should
2745 * An error can occur if the pad is not connected or when the downstream
2746 * peer elements cannot provide an acceptable buffer.
2751 gst_pad_alloc_buffer (GstPad * pad, guint64 offset, gint size, GstCaps * caps,
2754 return gst_pad_alloc_buffer_full (pad, offset, size, caps, buf, FALSE);
2758 * gst_pad_alloc_buffer_and_set_caps:
2759 * @pad: a source #GstPad
2760 * @offset: the offset of the new buffer in the stream
2761 * @size: the size of the new buffer
2762 * @caps: the caps of the new buffer
2763 * @buf: a newly allocated buffer
2765 * In addition to the function gst_pad_alloc_buffer(), this function
2766 * automatically calls gst_pad_set_caps() when the caps of the
2767 * newly allocated buffer are different from the @pad caps.
2769 * Returns: a result code indicating success of the operation. Any
2770 * result code other than #GST_FLOW_OK is an error and @buf should
2772 * An error can occur if the pad is not connected or when the downstream
2773 * peer elements cannot provide an acceptable buffer.
2778 gst_pad_alloc_buffer_and_set_caps (GstPad * pad, guint64 offset, gint size,
2779 GstCaps * caps, GstBuffer ** buf)
2781 return gst_pad_alloc_buffer_full (pad, offset, size, caps, buf, TRUE);
2785 * gst_pad_get_internal_links_default:
2786 * @pad: the #GstPad to get the internal links of.
2788 * Gets a list of pads to which the given pad is linked to
2789 * inside of the parent element.
2790 * This is the default handler, and thus returns a list of all of the
2791 * pads inside the parent element with opposite direction.
2792 * The caller must free this list after use.
2794 * Returns: a newly allocated #GList of pads, or NULL if the pad has no parent.
2799 gst_pad_get_internal_links_default (GstPad * pad)
2804 GstPadDirection direction;
2806 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2808 direction = pad->direction;
2810 parent = GST_PAD_PARENT (pad);
2814 parent_pads = parent->pads;
2816 while (parent_pads) {
2817 GstPad *parent_pad = GST_PAD_CAST (parent_pads->data);
2819 if (parent_pad->direction != direction) {
2820 res = g_list_prepend (res, parent_pad);
2823 parent_pads = g_list_next (parent_pads);
2830 * gst_pad_get_internal_links:
2831 * @pad: the #GstPad to get the internal links of.
2833 * Gets a list of pads to which the given pad is linked to
2834 * inside of the parent element.
2835 * The caller must free this list after use.
2837 * Returns: a newly allocated #GList of pads.
2842 gst_pad_get_internal_links (GstPad * pad)
2846 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2848 if (GST_PAD_INTLINKFUNC (pad))
2849 res = GST_PAD_INTLINKFUNC (pad) (pad);
2856 gst_pad_event_default_dispatch (GstPad * pad, GstEvent * event)
2861 GST_INFO_OBJECT (pad, "Sending event %p to all internally linked pads",
2864 result = (GST_PAD_DIRECTION (pad) == GST_PAD_SINK);
2866 orig = pads = gst_pad_get_internal_links (pad);
2869 GstPad *eventpad = GST_PAD_CAST (pads->data);
2871 pads = g_list_next (pads);
2873 if (GST_PAD_DIRECTION (eventpad) == GST_PAD_SRC) {
2874 /* for each pad we send to, we should ref the event; it's up
2875 * to downstream to unref again when handled. */
2876 GST_LOG_OBJECT (pad, "Reffing and sending event %p (%s) to %s:%s",
2877 event, GST_EVENT_TYPE_NAME (event), GST_DEBUG_PAD_NAME (eventpad));
2878 gst_event_ref (event);
2879 gst_pad_push_event (eventpad, event);
2881 /* we only send the event on one pad, multi-sinkpad elements
2882 * should implement a handler */
2883 GST_LOG_OBJECT (pad, "sending event %p (%s) to one sink pad %s:%s",
2884 event, GST_EVENT_TYPE_NAME (event), GST_DEBUG_PAD_NAME (eventpad));
2885 result = gst_pad_push_event (eventpad, event);
2889 /* we handled the incoming event so we unref once */
2890 GST_LOG_OBJECT (pad, "handled event %p, unreffing", event);
2891 gst_event_unref (event);
2900 * gst_pad_event_default:
2901 * @pad: a #GstPad to call the default event handler on.
2902 * @event: the #GstEvent to handle.
2904 * Invokes the default event handler for the given pad. End-of-stream and
2905 * discontinuity events are handled specially, and then the event is sent to all
2906 * pads internally linked to @pad. Note that if there are many possible sink
2907 * pads that are internally linked to @pad, only one will be sent an event.
2908 * Multi-sinkpad elements should implement custom event handlers.
2910 * Returns: TRUE if the event was sent succesfully.
2913 gst_pad_event_default (GstPad * pad, GstEvent * event)
2915 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2916 g_return_val_if_fail (event != NULL, FALSE);
2918 switch (GST_EVENT_TYPE (event)) {
2921 GST_DEBUG_OBJECT (pad, "pausing task because of eos");
2922 gst_pad_pause_task (pad);
2928 return gst_pad_event_default_dispatch (pad, event);
2932 * gst_pad_dispatcher:
2933 * @pad: a #GstPad to dispatch.
2934 * @dispatch: the #GstDispatcherFunction to call.
2935 * @data: gpointer user data passed to the dispatcher function.
2937 * Invokes the given dispatcher function on all pads that are
2938 * internally linked to the given pad.
2939 * The GstPadDispatcherFunction should return TRUE when no further pads
2940 * need to be processed.
2942 * Returns: TRUE if one of the dispatcher functions returned TRUE.
2945 gst_pad_dispatcher (GstPad * pad, GstPadDispatcherFunction dispatch,
2948 gboolean res = FALSE;
2949 GList *int_pads, *orig;
2951 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2952 g_return_val_if_fail (dispatch != NULL, FALSE);
2954 orig = int_pads = gst_pad_get_internal_links (pad);
2957 GstPad *int_pad = GST_PAD_CAST (int_pads->data);
2958 GstPad *int_peer = GST_PAD_PEER (int_pad);
2961 res = dispatch (int_peer, data);
2965 int_pads = g_list_next (int_pads);
2975 * @pad: a #GstPad to invoke the default query on.
2976 * @query: the #GstQuery to perform.
2978 * Dispatches a query to a pad. The query should have been allocated by the
2979 * caller via one of the type-specific allocation functions in gstquery.h. The
2980 * element is responsible for filling the query with an appropriate response,
2981 * which should then be parsed with a type-specific query parsing function.
2983 * Again, the caller is responsible for both the allocation and deallocation of
2984 * the query structure.
2986 * Returns: TRUE if the query could be performed.
2989 gst_pad_query (GstPad * pad, GstQuery * query)
2991 GstPadQueryFunction func;
2993 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2994 g_return_val_if_fail (GST_IS_QUERY (query), FALSE);
2996 GST_DEBUG_OBJECT (pad, "sending query %p", query);
2998 if ((func = GST_PAD_QUERYFUNC (pad)) == NULL)
3001 return func (pad, query);
3005 GST_DEBUG_OBJECT (pad, "had no query function");
3011 * gst_pad_query_default:
3012 * @pad: a #GstPad to call the default query handler on.
3013 * @query: the #GstQuery to handle.
3015 * Invokes the default query handler for the given pad.
3016 * The query is sent to all pads internally linked to @pad. Note that
3017 * if there are many possible sink pads that are internally linked to
3018 * @pad, only one will be sent the query.
3019 * Multi-sinkpad elements should implement custom query handlers.
3021 * Returns: TRUE if the query was performed succesfully.
3024 gst_pad_query_default (GstPad * pad, GstQuery * query)
3026 switch (GST_QUERY_TYPE (query)) {
3027 case GST_QUERY_POSITION:
3028 case GST_QUERY_SEEKING:
3029 case GST_QUERY_FORMATS:
3030 case GST_QUERY_LATENCY:
3031 case GST_QUERY_JITTER:
3032 case GST_QUERY_RATE:
3033 case GST_QUERY_CONVERT:
3035 return gst_pad_dispatcher
3036 (pad, (GstPadDispatcherFunction) gst_pad_query, query);
3040 #ifndef GST_DISABLE_LOADSAVE
3041 /* FIXME: why isn't this on a GstElement ? */
3043 * gst_pad_load_and_link:
3044 * @self: an #xmlNodePtr to read the description from.
3045 * @parent: the #GstObject element that owns the pad.
3047 * Reads the pad definition from the XML node and links the given pad
3048 * in the element to a pad of an element up in the hierarchy.
3051 gst_pad_load_and_link (xmlNodePtr self, GstObject * parent)
3053 xmlNodePtr field = self->xmlChildrenNode;
3054 GstPad *pad = NULL, *targetpad;
3058 GstObject *grandparent;
3062 if (!strcmp ((char *) field->name, "name")) {
3063 name = (gchar *) xmlNodeGetContent (field);
3064 pad = gst_element_get_pad (GST_ELEMENT (parent), name);
3066 } else if (!strcmp ((char *) field->name, "peer")) {
3067 peer = (gchar *) xmlNodeGetContent (field);
3069 field = field->next;
3071 g_return_if_fail (pad != NULL);
3076 split = g_strsplit (peer, ".", 2);
3078 if (split[0] == NULL || split[1] == NULL) {
3079 GST_CAT_DEBUG_OBJECT (GST_CAT_XML, pad,
3080 "Could not parse peer '%s', leaving unlinked", peer);
3087 g_return_if_fail (split[0] != NULL);
3088 g_return_if_fail (split[1] != NULL);
3090 grandparent = gst_object_get_parent (parent);
3092 if (grandparent && GST_IS_BIN (grandparent)) {
3093 target = gst_bin_get_by_name_recurse_up (GST_BIN (grandparent), split[0]);
3100 targetpad = gst_element_get_pad (target, split[1]);
3102 if (targetpad == NULL)
3105 gst_pad_link (pad, targetpad);
3112 * gst_pad_save_thyself:
3113 * @pad: a #GstPad to save.
3114 * @parent: the parent #xmlNodePtr to save the description in.
3116 * Saves the pad into an xml representation.
3118 * Returns: the #xmlNodePtr representation of the pad.
3121 gst_pad_save_thyself (GstObject * object, xmlNodePtr parent)
3126 g_return_val_if_fail (GST_IS_PAD (object), NULL);
3128 pad = GST_PAD (object);
3130 xmlNewChild (parent, NULL, (xmlChar *) "name",
3131 (xmlChar *) GST_PAD_NAME (pad));
3133 if (GST_PAD_IS_SRC (pad)) {
3134 xmlNewChild (parent, NULL, (xmlChar *) "direction", (xmlChar *) "source");
3135 } else if (GST_PAD_IS_SINK (pad)) {
3136 xmlNewChild (parent, NULL, (xmlChar *) "direction", (xmlChar *) "sink");
3138 xmlNewChild (parent, NULL, (xmlChar *) "direction", (xmlChar *) "unknown");
3141 if (GST_PAD_PEER (pad) != NULL) {
3144 peer = GST_PAD_PEER (pad);
3145 /* first check to see if the peer's parent's parent is the same */
3146 /* we just save it off */
3147 content = g_strdup_printf ("%s.%s",
3148 GST_OBJECT_NAME (GST_PAD_PARENT (peer)), GST_PAD_NAME (peer));
3149 xmlNewChild (parent, NULL, (xmlChar *) "peer", (xmlChar *) content);
3152 xmlNewChild (parent, NULL, (xmlChar *) "peer", NULL);
3159 * gst_ghost_pad_save_thyself:
3160 * @pad: a ghost #GstPad to save.
3161 * @parent: the parent #xmlNodePtr to save the description in.
3163 * Saves the ghost pad into an xml representation.
3165 * Returns: the #xmlNodePtr representation of the pad.
3168 gst_ghost_pad_save_thyself (GstPad * pad, xmlNodePtr parent)
3172 g_return_val_if_fail (GST_IS_GHOST_PAD (pad), NULL);
3174 self = xmlNewChild (parent, NULL, (xmlChar *) "ghostpad", NULL);
3175 xmlNewChild (self, NULL, (xmlChar *) "name", (xmlChar *) GST_PAD_NAME (pad));
3176 xmlNewChild (self, NULL, (xmlChar *) "parent",
3177 (xmlChar *) GST_OBJECT_NAME (GST_PAD_PARENT (pad)));
3179 /* FIXME FIXME FIXME! */
3184 #endif /* GST_DISABLE_LOADSAVE */
3187 * should be called with pad OBJECT_LOCK and STREAM_LOCK held.
3188 * GST_PAD_IS_BLOCKED (pad) == TRUE when this function is
3191 * This function perform the pad blocking when an event, buffer push
3192 * or buffer_alloc is performed on a _SRC_ pad. It blocks the
3193 * streaming thread after informing the pad has been blocked.
3195 * An application can with this method wait and block any streaming
3196 * thread and perform operations such as seeking or linking.
3198 * Two methods are available for notifying the application of the
3200 * - the callback method, which happens in the STREAMING thread with
3201 * the STREAM_LOCK held. With this method, the most usefull way of
3202 * dealing with the callback is to post a message to the main thread
3203 * where the pad block can then be handled outside of the streaming
3204 * thread. With the last method one can perform all operations such
3205 * as doing a state change, linking, unblocking, seeking etc on the
3207 * - the GCond signal method, which makes any thread unblock when
3208 * the pad block happens.
3210 * During the actual blocking state, the GST_PAD_BLOCKING flag is set.
3211 * The GST_PAD_BLOCKING flag is unset when the pad was unblocked.
3215 static GstFlowReturn
3216 handle_pad_block (GstPad * pad)
3218 GstPadBlockCallback callback;
3220 GstFlowReturn ret = GST_FLOW_OK;
3222 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "signal block taken");
3224 /* flushing, don't bother trying to block and return WRONG_STATE
3226 if (GST_PAD_IS_FLUSHING (pad))
3227 goto flushingnonref;
3229 /* we grab an extra ref for the callbacks, this is probably not
3230 * needed (callback code does not have a ref and cannot unref). I
3231 * think this was done to make it possible to unref the element in
3232 * the callback, which is in the end totally impossible as it
3233 * requires grabbing the STREAM_LOCK and OBJECT_LOCK which are
3234 * all taken when calling this function. */
3235 gst_object_ref (pad);
3237 /* we either have a callback installed to notify the block or
3238 * some other thread is doing a GCond wait. */
3239 callback = pad->block_callback;
3241 /* there is a callback installed, call it. We release the
3242 * lock so that the callback can do something usefull with the
3244 user_data = pad->block_data;
3245 GST_OBJECT_UNLOCK (pad);
3246 callback (pad, TRUE, user_data);
3247 GST_OBJECT_LOCK (pad);
3249 /* we released the lock, recheck flushing */
3250 if (GST_PAD_IS_FLUSHING (pad))
3253 /* no callback, signal the thread that is doing a GCond wait
3255 GST_PAD_BLOCK_SIGNAL (pad);
3258 /* OBJECT_LOCK could have been released when we did the callback, which
3259 * then could have made the pad unblock so we need to check the blocking
3260 * condition again. */
3261 while (GST_PAD_IS_BLOCKED (pad)) {
3262 /* now we block the streaming thread. It can be unlocked when we
3263 * deactivate the pad (which will also set the FLUSHING flag) or
3264 * when the pad is unblocked. A flushing event will also unblock
3265 * the pad after setting the FLUSHING flag. */
3266 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3267 "Waiting to be unblocked or set flushing");
3268 GST_OBJECT_FLAG_SET (pad, GST_PAD_BLOCKING);
3269 GST_PAD_BLOCK_WAIT (pad);
3270 GST_OBJECT_FLAG_UNSET (pad, GST_PAD_BLOCKING);
3272 /* see if we got unblocked by a flush or not */
3273 if (GST_PAD_IS_FLUSHING (pad))
3277 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "got unblocked");
3279 /* when we get here, the pad is unblocked again and we perform
3280 * the needed unblock code. */
3281 callback = pad->block_callback;
3283 /* we need to call the callback */
3284 user_data = pad->block_data;
3285 GST_OBJECT_UNLOCK (pad);
3286 callback (pad, FALSE, user_data);
3287 GST_OBJECT_LOCK (pad);
3289 /* we need to signal the thread waiting on the GCond */
3290 GST_PAD_BLOCK_SIGNAL (pad);
3293 gst_object_unref (pad);
3299 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "pad was flushing");
3300 return GST_FLOW_WRONG_STATE;
3304 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "pad became flushing");
3305 gst_object_unref (pad);
3306 return GST_FLOW_WRONG_STATE;
3310 /**********************************************************************
3311 * Data passing functions
3315 gst_pad_emit_have_data_signal (GstPad * pad, GstMiniObject * obj)
3318 GValue args[2] = { {0}, {0} };
3323 g_value_init (&ret, G_TYPE_BOOLEAN);
3324 g_value_set_boolean (&ret, TRUE);
3325 g_value_init (&args[0], GST_TYPE_PAD);
3326 g_value_set_object (&args[0], pad);
3327 g_value_init (&args[1], GST_TYPE_MINI_OBJECT); // G_TYPE_POINTER);
3328 gst_value_set_mini_object (&args[1], obj);
3330 if (GST_IS_EVENT (obj))
3331 detail = event_quark;
3333 detail = buffer_quark;
3336 g_signal_emitv (args, gst_pad_signals[PAD_HAVE_DATA], detail, &ret);
3337 res = g_value_get_boolean (&ret);
3340 g_value_unset (&ret);
3341 g_value_unset (&args[0]);
3342 g_value_unset (&args[1]);
3347 /* this is the chain function that does not perform the additional argument
3348 * checking for that little extra speed.
3350 static inline GstFlowReturn
3351 gst_pad_chain_unchecked (GstPad * pad, GstBuffer * buffer)
3354 gboolean caps_changed;
3355 GstPadChainFunction chainfunc;
3357 gboolean emit_signal;
3359 GST_PAD_STREAM_LOCK (pad);
3361 GST_OBJECT_LOCK (pad);
3362 if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad)))
3365 caps = GST_BUFFER_CAPS (buffer);
3366 caps_changed = caps && caps != GST_PAD_CAPS (pad);
3368 emit_signal = GST_PAD_DO_BUFFER_SIGNALS (pad) > 0;
3369 GST_OBJECT_UNLOCK (pad);
3371 /* see if the signal should be emited, we emit before caps nego as
3372 * we might drop the buffer and do capsnego for nothing. */
3373 if (G_UNLIKELY (emit_signal)) {
3374 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (buffer)))
3378 /* we got a new datatype on the pad, see if it can handle it */
3379 if (G_UNLIKELY (caps_changed)) {
3380 GST_DEBUG_OBJECT (pad, "caps changed to %p %" GST_PTR_FORMAT, caps, caps);
3381 if (G_UNLIKELY (!gst_pad_configure_sink (pad, caps)))
3382 goto not_negotiated;
3385 /* NOTE: we read the chainfunc unlocked.
3386 * we cannot hold the lock for the pad so we might send
3387 * the data to the wrong function. This is not really a
3388 * problem since functions are assigned at creation time
3389 * and don't change that often... */
3390 if (G_UNLIKELY ((chainfunc = GST_PAD_CHAINFUNC (pad)) == NULL))
3393 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3394 "calling chainfunction &%s", GST_DEBUG_FUNCPTR_NAME (chainfunc));
3396 ret = chainfunc (pad, buffer);
3398 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3399 "called chainfunction &%s, returned %s",
3400 GST_DEBUG_FUNCPTR_NAME (chainfunc), gst_flow_get_name (ret));
3402 GST_PAD_STREAM_UNLOCK (pad);
3409 gst_buffer_unref (buffer);
3410 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3411 "pushing, but pad was flushing");
3412 GST_OBJECT_UNLOCK (pad);
3413 GST_PAD_STREAM_UNLOCK (pad);
3414 return GST_FLOW_WRONG_STATE;
3418 gst_buffer_unref (buffer);
3419 GST_DEBUG_OBJECT (pad, "Dropping buffer due to FALSE probe return");
3420 GST_PAD_STREAM_UNLOCK (pad);
3425 gst_buffer_unref (buffer);
3426 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3427 "pushing buffer but pad did not accept");
3428 GST_PAD_STREAM_UNLOCK (pad);
3429 return GST_FLOW_NOT_NEGOTIATED;
3433 gst_buffer_unref (buffer);
3434 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3435 "pushing, but not chainhandler");
3436 GST_ELEMENT_ERROR (GST_PAD_PARENT (pad), CORE, PAD, (NULL),
3437 ("push on pad %s:%s but it has no chainfunction",
3438 GST_DEBUG_PAD_NAME (pad)));
3439 GST_PAD_STREAM_UNLOCK (pad);
3440 return GST_FLOW_NOT_SUPPORTED;
3446 * @pad: a sink #GstPad, returns GST_FLOW_ERROR if not.
3447 * @buffer: the #GstBuffer to send, return GST_FLOW_ERROR if not.
3449 * Chain a buffer to @pad.
3451 * The function returns #GST_FLOW_WRONG_STATE if the pad was flushing.
3453 * If the caps on @buffer are different from the current caps on @pad, this
3454 * function will call any setcaps function (see gst_pad_set_setcaps_function())
3455 * installed on @pad. If the new caps are not acceptable for @pad, this function
3456 * returns #GST_FLOW_NOT_NEGOTIATED.
3458 * The function proceeds calling the chain function installed on @pad (see
3459 * gst_pad_set_chain_function()) and the return value of that function is
3460 * returned to the caller. #GST_FLOW_NOT_SUPPORTED is returned if @pad has no
3463 * In all cases, success or failure, the caller loses its reference to @buffer
3464 * after calling this function.
3466 * Returns: a #GstFlowReturn from the pad.
3471 gst_pad_chain (GstPad * pad, GstBuffer * buffer)
3473 g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
3474 g_return_val_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SINK,
3476 g_return_val_if_fail (GST_IS_BUFFER (buffer), GST_FLOW_ERROR);
3478 return gst_pad_chain_unchecked (pad, buffer);
3483 * @pad: a source #GstPad, returns #GST_FLOW_ERROR if not.
3484 * @buffer: the #GstBuffer to push returns GST_FLOW_ERROR if not.
3486 * Pushes a buffer to the peer of @pad.
3488 * This function will call an installed pad block before triggering any
3489 * installed pad probes.
3491 * If the caps on @buffer are different from the currently configured caps on
3492 * @pad, this function will call any installed setcaps function on @pad (see
3493 * gst_pad_set_setcaps_function()). In case of failure to renegotiate the new
3494 * format, this function returns #GST_FLOW_NOT_NEGOTIATED.
3496 * The function proceeds calling gst_pad_chain() on the peer pad and returns the
3497 * value from that function. If @pad has no peer, #GST_FLOW_NOT_LINKED will be
3500 * In all cases, success or failure, the caller loses its reference to @buffer
3501 * after calling this function.
3503 * Returns: a #GstFlowReturn from the peer pad.
3508 gst_pad_push (GstPad * pad, GstBuffer * buffer)
3514 gboolean caps_changed;
3516 g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
3517 g_return_val_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SRC, GST_FLOW_ERROR);
3518 g_return_val_if_fail (GST_IS_BUFFER (buffer), GST_FLOW_ERROR);
3520 GST_OBJECT_LOCK (pad);
3522 /* FIXME: this check can go away; pad_set_blocked could be implemented with
3523 * probes completely or probes with an extended pad block. */
3524 while (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad)))
3525 if ((ret = handle_pad_block (pad)) != GST_FLOW_OK)
3528 /* we emit signals on the pad arg, the peer will have a chance to
3529 * emit in the _chain() function */
3530 if (G_UNLIKELY (GST_PAD_DO_BUFFER_SIGNALS (pad) > 0)) {
3531 /* unlock before emitting */
3532 GST_OBJECT_UNLOCK (pad);
3534 /* if the signal handler returned FALSE, it means we should just drop the
3536 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (buffer)))
3539 GST_OBJECT_LOCK (pad);
3542 if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
3545 /* take ref to peer pad before releasing the lock */
3546 gst_object_ref (peer);
3548 /* Before pushing the buffer to the peer pad, ensure that caps
3549 * are set on this pad */
3550 caps = GST_BUFFER_CAPS (buffer);
3551 caps_changed = caps && caps != GST_PAD_CAPS (pad);
3553 GST_OBJECT_UNLOCK (pad);
3555 /* we got a new datatype from the pad, it had better handle it */
3556 if (G_UNLIKELY (caps_changed)) {
3557 GST_DEBUG_OBJECT (pad, "caps changed to %p %" GST_PTR_FORMAT, caps, caps);
3558 if (G_UNLIKELY (!gst_pad_configure_src (pad, caps, TRUE)))
3559 goto not_negotiated;
3562 ret = gst_pad_chain_unchecked (peer, buffer);
3564 gst_object_unref (peer);
3568 /* ERROR recovery here */
3571 gst_buffer_unref (buffer);
3572 GST_DEBUG_OBJECT (pad, "pad block stopped by flush");
3573 GST_OBJECT_UNLOCK (pad);
3578 gst_buffer_unref (buffer);
3579 GST_DEBUG_OBJECT (pad, "Dropping buffer due to FALSE probe return");
3584 gst_buffer_unref (buffer);
3585 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3586 "pushing, but it was not linked");
3587 GST_OBJECT_UNLOCK (pad);
3588 return GST_FLOW_NOT_LINKED;
3592 gst_buffer_unref (buffer);
3593 gst_object_unref (peer);
3594 GST_CAT_DEBUG_OBJECT (GST_CAT_SCHEDULING, pad,
3595 "element pushed buffer then refused to accept the caps");
3596 return GST_FLOW_NOT_NEGOTIATED;
3601 * gst_pad_check_pull_range:
3602 * @pad: a sink #GstPad.
3604 * Checks if a gst_pad_pull_range() can be performed on the peer
3605 * source pad. This function is used by plugins that want to check
3606 * if they can use random access on the peer source pad.
3608 * The peer sourcepad can implement a custom #GstPadCheckGetRangeFunction
3609 * if it needs to perform some logic to determine if pull_range is
3612 * Returns: a gboolean with the result.
3617 gst_pad_check_pull_range (GstPad * pad)
3621 GstPadCheckGetRangeFunction checkgetrangefunc;
3623 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
3625 GST_OBJECT_LOCK (pad);
3626 if (GST_PAD_DIRECTION (pad) != GST_PAD_SINK)
3627 goto wrong_direction;
3629 if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
3632 gst_object_ref (peer);
3633 GST_OBJECT_UNLOCK (pad);
3635 /* see note in above function */
3636 if (G_LIKELY ((checkgetrangefunc = peer->checkgetrangefunc) == NULL)) {
3637 /* FIXME, kindoff ghetto */
3638 ret = GST_PAD_GETRANGEFUNC (peer) != NULL;
3640 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3641 "calling checkgetrangefunc %s of peer pad %s:%s",
3642 GST_DEBUG_FUNCPTR_NAME (checkgetrangefunc), GST_DEBUG_PAD_NAME (peer));
3644 ret = checkgetrangefunc (peer);
3647 gst_object_unref (peer);
3651 /* ERROR recovery here */
3654 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3655 "checking pull range, but pad must be a sinkpad");
3656 GST_OBJECT_UNLOCK (pad);
3661 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3662 "checking pull range, but it was not linked");
3663 GST_OBJECT_UNLOCK (pad);
3669 * gst_pad_get_range:
3670 * @pad: a src #GstPad, returns #GST_FLOW_ERROR if not.
3671 * @offset: The start offset of the buffer
3672 * @size: The length of the buffer
3673 * @buffer: a pointer to hold the #GstBuffer, returns #GST_FLOW_ERROR if %NULL.
3675 * When @pad is flushing this function returns #GST_FLOW_WRONG_STATE
3678 * Calls the getrange function of @pad, see #GstPadGetRangeFunction for a
3679 * description of a getrange function. If @pad has no getrange function
3680 * installed (see gst_pad_set_getrange_function()) this function returns
3681 * #GST_FLOW_NOT_SUPPORTED.
3683 * Returns: a #GstFlowReturn from the pad.
3688 gst_pad_get_range (GstPad * pad, guint64 offset, guint size,
3689 GstBuffer ** buffer)
3692 GstPadGetRangeFunction getrangefunc;
3693 gboolean emit_signal;
3695 g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
3696 g_return_val_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SRC, GST_FLOW_ERROR);
3697 g_return_val_if_fail (buffer != NULL, GST_FLOW_ERROR);
3699 GST_PAD_STREAM_LOCK (pad);
3701 GST_OBJECT_LOCK (pad);
3702 if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad)))
3705 emit_signal = GST_PAD_DO_BUFFER_SIGNALS (pad) > 0;
3706 GST_OBJECT_UNLOCK (pad);
3708 if (G_UNLIKELY ((getrangefunc = GST_PAD_GETRANGEFUNC (pad)) == NULL))
3711 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3712 "calling getrangefunc %s, offset %"
3713 G_GUINT64_FORMAT ", size %u",
3714 GST_DEBUG_FUNCPTR_NAME (getrangefunc), offset, size);
3716 ret = getrangefunc (pad, offset, size, buffer);
3718 /* can only fire the signal if we have a valid buffer */
3719 if (G_UNLIKELY (emit_signal) && (ret == GST_FLOW_OK)) {
3720 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (*buffer)))
3724 GST_PAD_STREAM_UNLOCK (pad);
3731 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3732 "pulling range, but pad was flushing");
3733 GST_OBJECT_UNLOCK (pad);
3734 GST_PAD_STREAM_UNLOCK (pad);
3735 return GST_FLOW_WRONG_STATE;
3739 GST_ELEMENT_ERROR (GST_PAD_PARENT (pad), CORE, PAD, (NULL),
3740 ("pullrange on pad %s:%s but it has no getrangefunction",
3741 GST_DEBUG_PAD_NAME (pad)));
3742 GST_PAD_STREAM_UNLOCK (pad);
3743 return GST_FLOW_NOT_SUPPORTED;
3747 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3748 "Dropping data after FALSE probe return");
3749 GST_PAD_STREAM_UNLOCK (pad);
3750 gst_buffer_unref (*buffer);
3752 return GST_FLOW_UNEXPECTED;
3758 * gst_pad_pull_range:
3759 * @pad: a sink #GstPad, returns GST_FLOW_ERROR if not.
3760 * @offset: The start offset of the buffer
3761 * @size: The length of the buffer
3762 * @buffer: a pointer to hold the #GstBuffer, returns GST_FLOW_ERROR if %NULL.
3764 * Pulls a buffer from the peer pad.
3766 * This function will first trigger the pad block signal if it was
3769 * When @pad is not linked #GST_FLOW_NOT_LINKED is returned else this
3770 * function returns the result of gst_pad_get_range() on the peer pad.
3771 * See gst_pad_get_range() for a list of return values and for the
3772 * semantics of the arguments of this function.
3774 * Returns: a #GstFlowReturn from the peer pad.
3775 * When this function returns #GST_FLOW_OK, @buffer will contain a valid
3776 * #GstBuffer that should be freed with gst_buffer_unref() after usage.
3777 * @buffer may not be used or freed when any other return value than
3778 * #GST_FLOW_OK is returned.
3783 gst_pad_pull_range (GstPad * pad, guint64 offset, guint size,
3784 GstBuffer ** buffer)
3788 gboolean emit_signal;
3790 g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
3791 g_return_val_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SINK,
3793 g_return_val_if_fail (buffer != NULL, GST_FLOW_ERROR);
3795 GST_OBJECT_LOCK (pad);
3797 while (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad)))
3798 handle_pad_block (pad);
3800 if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
3803 /* signal emision for the pad, peer has chance to emit when
3804 * we call _get_range() */
3805 emit_signal = GST_PAD_DO_BUFFER_SIGNALS (pad) > 0;
3807 gst_object_ref (peer);
3808 GST_OBJECT_UNLOCK (pad);
3810 ret = gst_pad_get_range (peer, offset, size, buffer);
3812 gst_object_unref (peer);
3814 /* can only fire the signal if we have a valid buffer */
3815 if (G_UNLIKELY (emit_signal) && (ret == GST_FLOW_OK)) {
3816 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (*buffer)))
3821 /* ERROR recovery here */
3824 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3825 "pulling range, but it was not linked");
3826 GST_OBJECT_UNLOCK (pad);
3827 return GST_FLOW_NOT_LINKED;
3831 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3832 "Dropping data after FALSE probe return");
3833 gst_buffer_unref (*buffer);
3835 return GST_FLOW_UNEXPECTED;
3840 * gst_pad_push_event:
3841 * @pad: a #GstPad to push the event to.
3842 * @event: the #GstEvent to send to the pad.
3844 * Sends the event to the peer of the given pad. This function is
3845 * mainly used by elements to send events to their peer
3848 * This function takes owership of the provided event so you should
3849 * gst_event_ref() it if you want to reuse the event after this call.
3851 * Returns: TRUE if the event was handled.
3856 gst_pad_push_event (GstPad * pad, GstEvent * event)
3861 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
3862 g_return_val_if_fail (event != NULL, FALSE);
3863 g_return_val_if_fail (GST_IS_EVENT (event), FALSE);
3865 GST_LOG_OBJECT (pad, "event:%s", GST_EVENT_TYPE_NAME (event));
3867 GST_OBJECT_LOCK (pad);
3869 /* Two checks to be made:
3870 * . (un)set the FLUSHING flag for flushing events,
3871 * . handle pad blocking */
3872 switch (GST_EVENT_TYPE (event)) {
3873 case GST_EVENT_FLUSH_START:
3874 GST_PAD_SET_FLUSHING (pad);
3876 if (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad))) {
3877 /* flush start will have set the FLUSHING flag and will then
3878 * unlock all threads doing a GCond wait on the blocking pad. This
3879 * will typically unblock the STREAMING thread blocked on a pad. */
3880 GST_LOG_OBJECT (pad, "Pad is blocked, not forwarding flush-start, "
3881 "doing block signal.");
3882 GST_PAD_BLOCK_SIGNAL (pad);
3886 case GST_EVENT_FLUSH_STOP:
3887 GST_PAD_UNSET_FLUSHING (pad);
3889 /* if we are blocked, flush away the FLUSH_STOP event */
3890 if (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad))) {
3891 GST_LOG_OBJECT (pad, "Pad is blocked, not forwarding flush-stop");
3896 while (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad))) {
3897 /* block the event as long as the pad is blocked */
3898 if (handle_pad_block (pad) != GST_FLOW_OK)
3904 if (G_UNLIKELY (GST_PAD_DO_EVENT_SIGNALS (pad) > 0)) {
3905 GST_OBJECT_UNLOCK (pad);
3907 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (event)))
3910 GST_OBJECT_LOCK (pad);
3912 peerpad = GST_PAD_PEER (pad);
3913 if (peerpad == NULL)
3916 GST_LOG_OBJECT (pad, "sending event to peerpad %" GST_PTR_FORMAT, peerpad);
3917 gst_object_ref (peerpad);
3918 GST_OBJECT_UNLOCK (pad);
3920 result = gst_pad_send_event (peerpad, event);
3922 GST_LOG_OBJECT (pad, "sent event to peerpad %" GST_PTR_FORMAT, peerpad);
3923 gst_object_unref (peerpad);
3927 /* ERROR handling */
3930 GST_DEBUG_OBJECT (pad, "Dropping event after FALSE probe return");
3931 gst_event_unref (event);
3936 GST_DEBUG_OBJECT (pad, "Dropping event because pad is not linked");
3937 gst_event_unref (event);
3938 GST_OBJECT_UNLOCK (pad);
3943 GST_DEBUG_OBJECT (pad,
3944 "Not forwarding event since we're flushing and blocking");
3945 gst_event_unref (event);
3946 GST_OBJECT_UNLOCK (pad);
3952 * gst_pad_send_event:
3953 * @pad: a #GstPad to send the event to.
3954 * @event: the #GstEvent to send to the pad.
3956 * Sends the event to the pad. This function can be used
3957 * by applications to send events in the pipeline.
3959 * If @pad is a source pad, @event should be an upstream event. If @pad is a
3960 * sink pad, @event should be a downstream event. For example, you would not
3961 * send a #GST_EVENT_EOS on a src pad; EOS events only propagate downstream.
3962 * Furthermore, some downstream events have to be serialized with data flow,
3963 * like EOS, while some can travel out-of-band, like #GST_EVENT_FLUSH_START. If
3964 * the event needs to be serialized with data flow, this function will take the
3965 * pad's stream lock while calling its event function.
3967 * To find out whether an event type is upstream, downstream, or downstream and
3968 * serialized, see #GstEventTypeFlags, gst_event_type_get_flags(),
3969 * #GST_EVENT_IS_UPSTREAM, #GST_EVENT_IS_DOWNSTREAM, and
3970 * #GST_EVENT_IS_SERIALIZED. Note that in practice that an application or plugin
3971 * doesn't need to bother itself with this information; the core handles all
3972 * necessary locks and checks.
3974 * This function takes owership of the provided event so you should
3975 * gst_event_ref() it if you want to reuse the event after this call.
3977 * Returns: TRUE if the event was handled.
3980 gst_pad_send_event (GstPad * pad, GstEvent * event)
3982 gboolean result = FALSE;
3983 GstPadEventFunction eventfunc;
3984 gboolean serialized, need_unlock = FALSE;
3986 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
3987 g_return_val_if_fail (event != NULL, FALSE);
3989 GST_OBJECT_LOCK (pad);
3990 if (GST_PAD_IS_SINK (pad)) {
3991 if (G_UNLIKELY (!GST_EVENT_IS_DOWNSTREAM (event)))
3992 goto wrong_direction;
3993 serialized = GST_EVENT_IS_SERIALIZED (event);
3994 } else if (GST_PAD_IS_SRC (pad)) {
3995 if (G_UNLIKELY (!GST_EVENT_IS_UPSTREAM (event)))
3996 goto wrong_direction;
3997 /* events on srcpad never are serialized */
4000 goto unknown_direction;
4002 if (G_UNLIKELY (GST_EVENT_SRC (event) == NULL)) {
4003 GST_LOG_OBJECT (pad, "event had no source, setting pad as event source");
4004 GST_EVENT_SRC (event) = gst_object_ref (pad);
4008 if (G_UNLIKELY (GST_PAD_DO_EVENT_SIGNALS (pad) > 0)) {
4009 GST_OBJECT_UNLOCK (pad);
4011 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT_CAST (event)))
4014 GST_OBJECT_LOCK (pad);
4017 switch (GST_EVENT_TYPE (event)) {
4018 case GST_EVENT_FLUSH_START:
4019 GST_CAT_DEBUG_OBJECT (GST_CAT_EVENT, pad,
4020 "have event type %d (FLUSH_START)", GST_EVENT_TYPE (event));
4022 /* can't even accept a flush begin event when flushing */
4023 if (GST_PAD_IS_FLUSHING (pad))
4025 GST_PAD_SET_FLUSHING (pad);
4026 GST_CAT_DEBUG_OBJECT (GST_CAT_EVENT, pad, "set flush flag");
4028 case GST_EVENT_FLUSH_STOP:
4029 GST_PAD_UNSET_FLUSHING (pad);
4030 GST_CAT_DEBUG_OBJECT (GST_CAT_EVENT, pad, "cleared flush flag");
4031 GST_OBJECT_UNLOCK (pad);
4032 /* grab stream lock */
4033 GST_PAD_STREAM_LOCK (pad);
4035 GST_OBJECT_LOCK (pad);
4038 GST_CAT_DEBUG_OBJECT (GST_CAT_EVENT, pad, "have event type %s",
4039 GST_EVENT_TYPE_NAME (event));
4041 /* make this a little faster, no point in grabbing the lock
4042 * if the pad is allready flushing. */
4043 if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad)))
4047 /* lock order: STREAM_LOCK, LOCK, recheck flushing. */
4048 GST_OBJECT_UNLOCK (pad);
4049 GST_PAD_STREAM_LOCK (pad);
4051 GST_OBJECT_LOCK (pad);
4052 if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad)))
4057 if (G_UNLIKELY ((eventfunc = GST_PAD_EVENTFUNC (pad)) == NULL))
4060 GST_OBJECT_UNLOCK (pad);
4062 result = eventfunc (pad, event);
4065 GST_PAD_STREAM_UNLOCK (pad);
4069 /* ERROR handling */
4072 g_warning ("pad %s:%s sending %s event in wrong direction",
4073 GST_DEBUG_PAD_NAME (pad), GST_EVENT_TYPE_NAME (event));
4074 GST_OBJECT_UNLOCK (pad);
4075 gst_event_unref (event);
4080 g_warning ("pad %s:%s has invalid direction", GST_DEBUG_PAD_NAME (pad));
4081 GST_OBJECT_UNLOCK (pad);
4082 gst_event_unref (event);
4087 g_warning ("pad %s:%s has no event handler, file a bug.",
4088 GST_DEBUG_PAD_NAME (pad));
4089 GST_OBJECT_UNLOCK (pad);
4090 gst_event_unref (event);
4095 GST_OBJECT_UNLOCK (pad);
4097 GST_PAD_STREAM_UNLOCK (pad);
4098 GST_CAT_INFO_OBJECT (GST_CAT_EVENT, pad,
4099 "Received event on flushing pad. Discarding");
4100 gst_event_unref (event);
4105 GST_DEBUG_OBJECT (pad, "Dropping event after FALSE probe return");
4106 gst_event_unref (event);
4112 * gst_pad_set_element_private:
4113 * @pad: the #GstPad to set the private data of.
4114 * @priv: The private data to attach to the pad.
4116 * Set the given private data gpointer on the pad.
4117 * This function can only be used by the element that owns the pad.
4118 * No locking is performed in this function.
4121 gst_pad_set_element_private (GstPad * pad, gpointer priv)
4123 pad->element_private = priv;
4127 * gst_pad_get_element_private:
4128 * @pad: the #GstPad to get the private data of.
4130 * Gets the private data of a pad.
4131 * No locking is performed in this function.
4133 * Returns: a #gpointer to the private data.
4136 gst_pad_get_element_private (GstPad * pad)
4138 return pad->element_private;
4142 * gst_pad_start_task:
4143 * @pad: the #GstPad to start the task of
4144 * @func: the task function to call
4145 * @data: data passed to the task function
4147 * Starts a task that repeadedly calls @func with @data. This function
4148 * is nostly used in the pad activation function to start the
4149 * dataflow. This function will automatically acquire the STREAM_LOCK of
4150 * the pad before calling @func.
4152 * Returns: a TRUE if the task could be started.
4155 gst_pad_start_task (GstPad * pad, GstTaskFunction func, gpointer data)
4159 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
4160 g_return_val_if_fail (func != NULL, FALSE);
4162 GST_DEBUG_OBJECT (pad, "start task");
4164 GST_OBJECT_LOCK (pad);
4165 task = GST_PAD_TASK (pad);
4167 task = gst_task_create (func, data);
4168 gst_task_set_lock (task, GST_PAD_GET_STREAM_LOCK (pad));
4169 GST_PAD_TASK (pad) = task;
4170 GST_DEBUG_OBJECT (pad, "created task");
4172 gst_task_start (task);
4173 GST_OBJECT_UNLOCK (pad);
4179 * gst_pad_pause_task:
4180 * @pad: the #GstPad to pause the task of
4182 * Pause the task of @pad. This function will also make sure that the
4183 * function executed by the task will effectively stop.
4185 * Returns: a TRUE if the task could be paused or FALSE when the pad
4189 gst_pad_pause_task (GstPad * pad)
4193 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
4195 GST_DEBUG_OBJECT (pad, "pause task");
4197 GST_OBJECT_LOCK (pad);
4198 task = GST_PAD_TASK (pad);
4201 gst_task_pause (task);
4202 GST_OBJECT_UNLOCK (pad);
4204 GST_PAD_STREAM_LOCK (pad);
4205 GST_PAD_STREAM_UNLOCK (pad);
4211 GST_DEBUG_OBJECT (pad, "pad has no task");
4212 GST_OBJECT_UNLOCK (pad);
4218 * gst_pad_stop_task:
4219 * @pad: the #GstPad to stop the task of
4221 * Stop the task of @pad. This function will also make sure that the
4222 * function executed by the task will effectively stop if not called
4223 * from the GstTaskFunction.
4225 * This function will deadlock if called from the GstTaskFunction of
4226 * the task. Use gst_task_pause() instead.
4228 * Regardless of whether the pad has a task, the stream lock is acquired and
4229 * released so as to ensure that streaming through this pad has finished.
4231 * Returns: a TRUE if the task could be stopped or FALSE on error.
4234 gst_pad_stop_task (GstPad * pad)
4238 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
4240 GST_DEBUG_OBJECT (pad, "stop task");
4242 GST_OBJECT_LOCK (pad);
4243 task = GST_PAD_TASK (pad);
4246 GST_PAD_TASK (pad) = NULL;
4247 gst_task_stop (task);
4248 GST_OBJECT_UNLOCK (pad);
4250 GST_PAD_STREAM_LOCK (pad);
4251 GST_PAD_STREAM_UNLOCK (pad);
4253 if (!gst_task_join (task))
4256 gst_object_unref (task);
4262 GST_DEBUG_OBJECT (pad, "no task");
4263 GST_OBJECT_UNLOCK (pad);
4265 GST_PAD_STREAM_LOCK (pad);
4266 GST_PAD_STREAM_UNLOCK (pad);
4268 /* this is not an error */
4273 /* this is bad, possibly the application tried to join the task from
4274 * the task's thread. We install the task again so that it will be stopped
4275 * again from the right thread next time hopefully. */
4276 GST_OBJECT_LOCK (pad);
4277 GST_DEBUG_OBJECT (pad, "join failed");
4278 /* we can only install this task if there was no other task */
4279 if (GST_PAD_TASK (pad) == NULL)
4280 GST_PAD_TASK (pad) = task;
4281 GST_OBJECT_UNLOCK (pad);