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_try_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() to push out
55 * or pull in a buffer.
56 * gst_pad_select() and gst_pad_selectv() are used by plugins to wait for the
57 * first incoming buffer or event on any of the given set of pads.
59 * To send a #GstEvent on a pad, use gst_pad_send_event().
61 * Last reviewed on December 13th, 2002 (0.5.0.1)
64 #include "gst_private.h"
67 #include "gstpadtemplate.h"
68 #include "gstenumtypes.h"
69 #include "gstmarshal.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 void 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);
112 #ifndef GST_DISABLE_LOADSAVE
113 static xmlNodePtr gst_pad_save_thyself (GstObject * object, xmlNodePtr parent);
116 static GstObjectClass *parent_class = NULL;
117 static guint gst_pad_signals[LAST_SIGNAL] = { 0 };
119 /* quarks for probe signals */
120 static GQuark buffer_quark;
121 static GQuark event_quark;
130 static GstFlowQuarks flow_quarks[] = {
131 {GST_FLOW_RESEND, "resend", 0},
132 {GST_FLOW_OK, "ok", 0},
133 {GST_FLOW_NOT_LINKED, "not-linked", 0},
134 {GST_FLOW_WRONG_STATE, "wrong-state", 0},
135 {GST_FLOW_UNEXPECTED, "unexpected", 0},
136 {GST_FLOW_NOT_NEGOTIATED, "not-negotiated", 0},
137 {GST_FLOW_ERROR, "error", 0},
138 {GST_FLOW_NOT_SUPPORTED, "not-supported", 0},
145 * @ret: a #GstFlowReturn to get the name of.
147 * Gets a string representing the given flow return.
149 * Returns: a string with the name of the flow return.
151 G_CONST_RETURN gchar *
152 gst_flow_get_name (GstFlowReturn ret)
156 for (i = 0; flow_quarks[i].name; i++) {
157 if (ret == flow_quarks[i].ret)
158 return flow_quarks[i].name;
165 * @ret: a #GstFlowReturn to get the quark of.
167 * Get the unique quark for the given GstFlowReturn.
169 * Returns: the quark associated with the flow return or 0 if an
170 * invalid return was specified.
173 gst_flow_to_quark (GstFlowReturn ret)
177 for (i = 0; flow_quarks[i].name; i++) {
178 if (ret == flow_quarks[i].ret)
179 return flow_quarks[i].quark;
185 gst_pad_get_type (void)
187 static GType gst_pad_type = 0;
190 static const GTypeInfo pad_info = {
191 sizeof (GstPadClass), NULL, NULL,
192 (GClassInitFunc) gst_pad_class_init, NULL, NULL,
195 (GInstanceInitFunc) gst_pad_init, NULL
199 gst_pad_type = g_type_register_static (GST_TYPE_OBJECT, "GstPad",
202 buffer_quark = g_quark_from_static_string ("buffer");
203 event_quark = g_quark_from_static_string ("event");
205 for (i = 0; flow_quarks[i].name; i++) {
206 flow_quarks[i].quark = g_quark_from_static_string (flow_quarks[i].name);
209 GST_DEBUG_CATEGORY_INIT (debug_dataflow, "GST_DATAFLOW",
210 GST_DEBUG_BOLD | GST_DEBUG_FG_GREEN, "dataflow inside pads");
216 _gst_do_pass_data_accumulator (GSignalInvocationHint * ihint,
217 GValue * return_accu, const GValue * handler_return, gpointer dummy)
219 gboolean ret = g_value_get_boolean (handler_return);
221 GST_DEBUG ("accumulated %d", ret);
222 g_value_set_boolean (return_accu, ret);
228 default_have_data (GstPad * pad, GstMiniObject * o)
234 gst_pad_class_init (GstPadClass * klass)
236 GObjectClass *gobject_class;
239 GstObjectClass *gstobject_class;
241 gobject_class = (GObjectClass *) klass;
242 gstobject_class = (GstObjectClass *) klass;
244 parent_class = g_type_class_ref (GST_TYPE_OBJECT);
246 gobject_class->dispose = GST_DEBUG_FUNCPTR (gst_pad_dispose);
247 gobject_class->finalize = GST_DEBUG_FUNCPTR (gst_pad_finalize);
248 gobject_class->set_property = GST_DEBUG_FUNCPTR (gst_pad_set_property);
249 gobject_class->get_property = GST_DEBUG_FUNCPTR (gst_pad_get_property);
253 * @pad: the pad that emitted the signal
254 * @peer: the peer pad that has been connected
256 * Signals that a pad has been linked to the peer pad.
258 gst_pad_signals[PAD_LINKED] =
259 g_signal_new ("linked", G_TYPE_FROM_CLASS (klass), G_SIGNAL_RUN_LAST,
260 G_STRUCT_OFFSET (GstPadClass, linked), NULL, NULL,
261 gst_marshal_VOID__OBJECT, G_TYPE_NONE, 1, GST_TYPE_PAD);
264 * @pad: the pad that emitted the signal
265 * @peer: the peer pad that has been disconnected
267 * Signals that a pad has been unlinked from the peer pad.
269 gst_pad_signals[PAD_UNLINKED] =
270 g_signal_new ("unlinked", G_TYPE_FROM_CLASS (klass), G_SIGNAL_RUN_LAST,
271 G_STRUCT_OFFSET (GstPadClass, unlinked), NULL, NULL,
272 gst_marshal_VOID__OBJECT, G_TYPE_NONE, 1, GST_TYPE_PAD);
274 * GstPad::request-link:
275 * @pad: the pad that emitted the signal
276 * @peer: the peer pad for which a connection is requested
278 * Signals that a pad connection has been requested.
280 gst_pad_signals[PAD_REQUEST_LINK] =
281 g_signal_new ("request-link", G_TYPE_FROM_CLASS (klass),
282 G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GstPadClass, request_link), NULL,
283 NULL, gst_marshal_VOID__OBJECT, G_TYPE_NONE, 0);
287 * @pad: the pad that emitted the signal
288 * @mini_obj: new data
290 * Signals that new data is available on the pad. This signal is used
291 * internally for implementing pad probes.
292 * See gst_pad_add_*_probe functions.
294 * Returns: %TRUE to keep the data, %FALSE to drop it
296 gst_pad_signals[PAD_HAVE_DATA] =
297 g_signal_new ("have-data", G_TYPE_FROM_CLASS (klass),
298 G_SIGNAL_RUN_LAST | G_SIGNAL_DETAILED,
299 G_STRUCT_OFFSET (GstPadClass, have_data),
300 _gst_do_pass_data_accumulator,
301 NULL, gst_marshal_BOOLEAN__POINTER, G_TYPE_BOOLEAN, 1,
302 GST_TYPE_MINI_OBJECT);
304 g_object_class_install_property (G_OBJECT_CLASS (klass), PAD_PROP_CAPS,
305 g_param_spec_boxed ("caps", "Caps", "The capabilities of the pad",
306 GST_TYPE_CAPS, G_PARAM_READABLE));
307 g_object_class_install_property (G_OBJECT_CLASS (klass), PAD_PROP_DIRECTION,
308 g_param_spec_enum ("direction", "Direction", "The direction of the pad",
309 GST_TYPE_PAD_DIRECTION, GST_PAD_UNKNOWN,
310 G_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY));
311 g_object_class_install_property (G_OBJECT_CLASS (klass), PAD_PROP_TEMPLATE,
312 g_param_spec_object ("template", "Template",
313 "The GstPadTemplate of this pad", GST_TYPE_PAD_TEMPLATE,
316 #ifndef GST_DISABLE_LOADSAVE
317 gstobject_class->save_thyself = GST_DEBUG_FUNCPTR (gst_pad_save_thyself);
319 gstobject_class->path_string_separator = ".";
321 klass->have_data = default_have_data;
325 gst_pad_init (GstPad * pad)
327 pad->direction = GST_PAD_UNKNOWN;
330 pad->chainfunc = NULL;
334 pad->linkfunc = NULL;
335 pad->getcapsfunc = NULL;
337 pad->activatefunc = gst_pad_activate_default;
338 pad->eventfunc = gst_pad_event_default;
339 pad->querytypefunc = gst_pad_get_query_types_default;
340 pad->queryfunc = gst_pad_query_default;
341 pad->intlinkfunc = gst_pad_get_internal_links_default;
343 pad->do_buffer_signals = 0;
344 pad->do_event_signals = 0;
346 GST_PAD_UNSET_FLUSHING (pad);
348 pad->preroll_lock = g_mutex_new ();
349 pad->preroll_cond = g_cond_new ();
351 pad->stream_rec_lock = g_new (GStaticRecMutex, 1);
352 g_static_rec_mutex_init (pad->stream_rec_lock);
354 pad->block_cond = g_cond_new ();
358 gst_pad_dispose (GObject * object)
360 GstPad *pad = GST_PAD (object);
362 GST_CAT_DEBUG (GST_CAT_REFCOUNTING, "dispose %s:%s",
363 GST_DEBUG_PAD_NAME (pad));
365 /* we don't hold a ref to the peer so we can just set the
367 GST_PAD_PEER (pad) = NULL;
370 gst_caps_replace (&GST_PAD_CAPS (pad), NULL);
372 gst_pad_set_pad_template (pad, NULL);
374 G_OBJECT_CLASS (parent_class)->dispose (object);
378 gst_pad_finalize (GObject * object)
380 GstPad *pad = GST_PAD (object);
383 /* in case the task is still around, clean it up */
384 if ((task = GST_PAD_TASK (pad))) {
385 gst_task_join (task);
386 GST_PAD_TASK (pad) = NULL;
387 gst_object_unref (task);
390 if (pad->stream_rec_lock) {
391 g_static_rec_mutex_free (pad->stream_rec_lock);
392 g_free (pad->stream_rec_lock);
393 pad->stream_rec_lock = NULL;
395 if (pad->preroll_lock) {
396 g_mutex_free (pad->preroll_lock);
397 g_cond_free (pad->preroll_cond);
398 pad->preroll_lock = NULL;
399 pad->preroll_cond = NULL;
401 if (pad->block_cond) {
402 g_cond_free (pad->block_cond);
403 pad->block_cond = NULL;
406 G_OBJECT_CLASS (parent_class)->finalize (object);
410 gst_pad_set_property (GObject * object, guint prop_id,
411 const GValue * value, GParamSpec * pspec)
413 g_return_if_fail (GST_IS_PAD (object));
416 case PAD_PROP_DIRECTION:
417 GST_PAD_DIRECTION (object) = g_value_get_enum (value);
419 case PAD_PROP_TEMPLATE:
420 gst_pad_set_pad_template (GST_PAD_CAST (object),
421 (GstPadTemplate *) g_value_dup_object (value));
424 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
430 gst_pad_get_property (GObject * object, guint prop_id,
431 GValue * value, GParamSpec * pspec)
433 g_return_if_fail (GST_IS_PAD (object));
437 g_value_set_boxed (value, GST_PAD_CAPS (object));
439 case PAD_PROP_DIRECTION:
440 g_value_set_enum (value, GST_PAD_DIRECTION (object));
442 case PAD_PROP_TEMPLATE:
443 g_value_set_object (value, GST_PAD_TEMPLATE (object));
446 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
453 * @name: the name of the new pad.
454 * @direction: the #GstPadDirection of the pad.
456 * Creates a new pad with the given name in the given direction.
457 * If name is NULL, a guaranteed unique name (across all pads)
459 * This function makes a copy of the name so you can safely free the name.
461 * Returns: a new #GstPad, or NULL in case of an error.
466 gst_pad_new (const gchar * name, GstPadDirection direction)
468 return g_object_new (GST_TYPE_PAD,
469 "name", name, "direction", direction, NULL);
473 * gst_pad_new_from_template:
474 * @templ: the pad template to use
475 * @name: the name of the element
477 * Creates a new pad with the given name from the given template.
478 * If name is NULL, a guaranteed unique name (across all pads)
480 * This function makes a copy of the name so you can safely free the name.
482 * Returns: a new #GstPad, or NULL in case of an error.
485 gst_pad_new_from_template (GstPadTemplate * templ, const gchar * name)
487 g_return_val_if_fail (GST_IS_PAD_TEMPLATE (templ), NULL);
489 return g_object_new (GST_TYPE_PAD,
490 "name", name, "direction", templ->direction, "template", templ, NULL);
494 * gst_pad_get_direction:
495 * @pad: a #GstPad to get the direction of.
497 * Gets the direction of the pad. The direction of the pad is
498 * decided at construction time so this function does not take
501 * Returns: the #GstPadDirection of the pad.
506 gst_pad_get_direction (GstPad * pad)
508 GstPadDirection result;
510 /* PAD_UNKNOWN is a little silly but we need some sort of
511 * error return value */
512 g_return_val_if_fail (GST_IS_PAD (pad), GST_PAD_UNKNOWN);
515 result = GST_PAD_DIRECTION (pad);
522 gst_pad_activate_default (GstPad * pad)
524 return gst_pad_activate_push (pad, TRUE);
528 pre_activate (GstPad * pad, GstActivateMode new_mode)
531 case GST_ACTIVATE_PUSH:
532 case GST_ACTIVATE_PULL:
534 GST_DEBUG_OBJECT (pad, "setting ACTIVATE_MODE %d, unset flushing",
536 GST_PAD_UNSET_FLUSHING (pad);
537 GST_PAD_ACTIVATE_MODE (pad) = new_mode;
540 case GST_ACTIVATE_NONE:
542 GST_DEBUG_OBJECT (pad, "setting ACTIVATE_MODE NONE, set flushing",
544 GST_PAD_SET_FLUSHING (pad);
545 /* unlock blocked pads so element can resume and stop */
546 GST_PAD_BLOCK_SIGNAL (pad);
553 post_activate (GstPad * pad, GstActivateMode new_mode)
556 case GST_ACTIVATE_PUSH:
557 case GST_ACTIVATE_PULL:
560 case GST_ACTIVATE_NONE:
561 /* ensures that streaming stops */
562 GST_STREAM_LOCK (pad);
563 /* while we're at it set activation mode */
565 GST_DEBUG_OBJECT (pad, "setting ACTIVATE_MODE %d", new_mode);
566 GST_PAD_ACTIVATE_MODE (pad) = new_mode;
568 GST_STREAM_UNLOCK (pad);
574 * gst_pad_set_active:
575 * @pad: the #GstPad to activate or deactivate.
576 * @active: whether or not the pad should be active.
578 * Activates or deactivates the given pad.
579 * Must be called with the parent element's #GST_STATE_LOCK held.
580 * Normally called from within core state change functions.
582 * If @active, makes sure the pad is active. If it is already active, either in
583 * push or pull mode, just return. Otherwise dispatches to the pad's activate
584 * function to perform the actual activation.
586 * If not @active, checks the pad's current mode and calls
587 * gst_pad_activate_push() or gst_pad_activate_pull(), as appropriate, with a
590 * Returns: #TRUE if the operation was successful.
592 * MT safe. Must be called with parent element's #GST_STATE_LOCK held.
595 gst_pad_set_active (GstPad * pad, gboolean active)
598 gboolean ret = FALSE;
600 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
603 old = GST_PAD_ACTIVATE_MODE (pad);
608 case GST_ACTIVATE_PUSH:
609 case GST_ACTIVATE_PULL:
612 case GST_ACTIVATE_NONE:
613 ret = (GST_PAD_ACTIVATEFUNC (pad)) (pad);
618 case GST_ACTIVATE_PUSH:
619 ret = gst_pad_activate_push (pad, FALSE);
621 case GST_ACTIVATE_PULL:
622 ret = gst_pad_activate_pull (pad, FALSE);
624 case GST_ACTIVATE_NONE:
630 if (!active && !ret) {
632 g_critical ("Failed to deactivate pad %s:%s, very bad",
633 GST_DEBUG_PAD_NAME (pad));
641 * gst_pad_activate_pull:
642 * @pad: the #GstPad to activate or deactivate.
643 * @active: whether or not the pad should be active.
645 * Activates or deactivates the given pad in pull mode via dispatching to the
646 * pad's activatepullfunc. For use from within pad activation functions only.
647 * When called on sink pads, will first proxy the call to the peer pad, which is
648 * expected to activate its internally linked pads from within its activate_pull
651 * If you don't know what this is, you probably don't want to call it.
653 * Returns: TRUE if the operation was successfull.
658 gst_pad_activate_pull (GstPad * pad, gboolean active)
660 GstActivateMode old, new;
663 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
666 old = GST_PAD_ACTIVATE_MODE (pad);
669 if ((active && old == GST_ACTIVATE_PULL)
670 || (!active && old == GST_ACTIVATE_NONE))
674 g_return_val_if_fail (old == GST_ACTIVATE_NONE, FALSE);
676 g_return_val_if_fail (old == GST_ACTIVATE_PULL, FALSE);
679 if (gst_pad_get_direction (pad) == GST_PAD_SINK) {
680 if ((peer = gst_pad_get_peer (pad))) {
681 if (!gst_pad_activate_pull (peer, active))
683 gst_object_unref (peer);
687 new = active ? GST_ACTIVATE_PULL : GST_ACTIVATE_NONE;
688 pre_activate (pad, new);
690 if (GST_PAD_ACTIVATEPULLFUNC (pad)) {
691 if (!GST_PAD_ACTIVATEPULLFUNC (pad) (pad, active))
694 /* can happen for sinks of passthrough elements */
697 post_activate (pad, new);
699 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "%s in pull mode",
700 active ? "activated" : "deactivated");
705 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "already %s in pull mode",
706 active ? "activated" : "deactivated");
712 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
713 "activate_pull on peer (%s:%s) failed", GST_DEBUG_PAD_NAME (peer));
715 gst_object_unref (peer);
720 GST_CAT_INFO_OBJECT (GST_CAT_PADS, pad, "failed to %s in pull mode",
721 active ? "activate" : "deactivate");
722 pre_activate (pad, GST_ACTIVATE_NONE);
723 post_activate (pad, GST_ACTIVATE_NONE);
729 * gst_pad_activate_push:
730 * @pad: the #GstPad to activate or deactivate.
731 * @active: whether or not the pad should be active.
733 * Activates or deactivates the given pad in push mode via dispatching to the
734 * pad's activatepushfunc. For use from within pad activation functions only.
736 * If you don't know what this is, you probably don't want to call it.
738 * Returns: TRUE if the operation was successfull.
743 gst_pad_activate_push (GstPad * pad, gboolean active)
745 GstActivateMode old, new;
747 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
748 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "trying to set %s in push mode",
749 active ? "activated" : "deactivated");
752 old = GST_PAD_ACTIVATE_MODE (pad);
755 if ((active && old == GST_ACTIVATE_PUSH)
756 || (!active && old == GST_ACTIVATE_NONE))
760 g_return_val_if_fail (old == GST_ACTIVATE_NONE, FALSE);
762 g_return_val_if_fail (old == GST_ACTIVATE_PUSH, FALSE);
765 new = active ? GST_ACTIVATE_PUSH : GST_ACTIVATE_NONE;
766 pre_activate (pad, new);
768 if (GST_PAD_ACTIVATEPUSHFUNC (pad)) {
769 if (!GST_PAD_ACTIVATEPUSHFUNC (pad) (pad, active)) {
773 /* quite ok, element relies on state change func to prepare itself */
776 post_activate (pad, new);
778 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "%s in push mode",
779 active ? "activated" : "deactivated");
784 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "already %s in push mode",
785 active ? "activated" : "deactivated");
790 GST_CAT_INFO_OBJECT (GST_CAT_PADS, pad, "failed to %s in push mode",
791 active ? "activate" : "deactivate");
792 pre_activate (pad, GST_ACTIVATE_NONE);
793 post_activate (pad, GST_ACTIVATE_NONE);
800 * @pad: the #GstPad to query
802 * Query if a pad is active
804 * Returns: TRUE if the pad is active.
809 gst_pad_is_active (GstPad * pad)
811 gboolean result = FALSE;
813 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
816 result = GST_PAD_MODE_ACTIVATE (GST_PAD_ACTIVATE_MODE (pad));
823 * gst_pad_set_blocked_async:
824 * @pad: the #GstPad to block or unblock
825 * @blocked: boolean indicating whether the pad should be blocked or unblocked
826 * @callback: #GstPadBlockCallback that will be called when the
828 * @user_data: user data passed to the callback
830 * Blocks or unblocks the dataflow on a pad. The provided callback
831 * is called when the operation succeeds; this happens right before the next
832 * attempt at pushing a buffer on the pad.
834 * This can take a while as the pad can only become blocked when real dataflow
836 * When the pipeline is stalled, for example in PAUSED, this can
837 * take an indeterminate amount of time.
838 * You can pass NULL as the callback to make this call block. Be careful with
839 * this blocking call as it might not return for reasons stated above.
841 * Returns: TRUE if the pad could be blocked. This function can fail
842 * if wrong parameters were passed or the pad was already in the
848 gst_pad_set_blocked_async (GstPad * pad, gboolean blocked,
849 GstPadBlockCallback callback, gpointer user_data)
851 gboolean was_blocked;
853 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
857 was_blocked = GST_PAD_IS_BLOCKED (pad);
859 if (G_UNLIKELY (was_blocked == blocked))
860 goto had_right_state;
863 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "blocking pad %s:%s",
864 GST_DEBUG_PAD_NAME (pad));
866 GST_OBJECT_FLAG_SET (pad, GST_PAD_BLOCKED);
867 pad->block_callback = callback;
868 pad->block_data = user_data;
870 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "waiting for block");
871 GST_PAD_BLOCK_WAIT (pad);
872 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "blocked");
875 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "unblocking pad %s:%s",
876 GST_DEBUG_PAD_NAME (pad));
878 GST_OBJECT_FLAG_UNSET (pad, GST_PAD_BLOCKED);
880 pad->block_callback = callback;
881 pad->block_data = user_data;
884 GST_PAD_BLOCK_SIGNAL (pad);
886 GST_PAD_BLOCK_SIGNAL (pad);
887 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "waiting for unblock");
888 GST_PAD_BLOCK_WAIT (pad);
889 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "unblocked");
898 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
899 "pad %s:%s was in right state", GST_DEBUG_PAD_NAME (pad));
906 * gst_pad_set_blocked:
907 * @pad: the #GstPad to block or unblock
908 * @blocked: boolean indicating we should block or unblock
910 * Blocks or unblocks the dataflow on a pad. This function is
911 * a shortcut for gst_pad_set_blocked_async() with a NULL
914 * Returns: TRUE if the pad could be blocked. This function can fail
915 * wrong parameters were passed or the pad was already in the
921 gst_pad_set_blocked (GstPad * pad, gboolean blocked)
923 return gst_pad_set_blocked_async (pad, blocked, NULL, NULL);
927 * gst_pad_is_blocked:
928 * @pad: the #GstPad to query
930 * Checks if the pad is blocked or not. This function returns the
931 * last requested state of the pad. It is not certain that the pad
932 * is actually blocked at this point.
934 * Returns: TRUE if the pad is blocked.
939 gst_pad_is_blocked (GstPad * pad)
941 gboolean result = FALSE;
943 g_return_val_if_fail (GST_IS_PAD (pad), result);
946 result = GST_OBJECT_FLAG_IS_SET (pad, GST_PAD_BLOCKED);
953 * gst_pad_set_activate_function:
954 * @pad: a sink #GstPad.
955 * @activate: the #GstPadActivateFunction to set.
957 * Sets the given activate function for the pad. The activate function will
958 * dispatch to activate_push or activate_pull to perform the actual activation.
959 * Only makes sense to set on sink pads.
961 * Call this function if your sink pad can start a pull-based task.
964 gst_pad_set_activate_function (GstPad * pad, GstPadActivateFunction activate)
966 g_return_if_fail (GST_IS_PAD (pad));
968 GST_PAD_ACTIVATEFUNC (pad) = activate;
969 GST_CAT_DEBUG (GST_CAT_PADS, "activatefunc for %s:%s set to %s",
970 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (activate));
974 * gst_pad_set_activatepull_function:
975 * @pad: a sink #GstPad.
976 * @activatepull: the #GstPadActivateModeFunction to set.
978 * Sets the given activate_pull function for the pad. An activate_pull function
979 * prepares the element and any upstream connections for pulling. See XXX
980 * part-activation.txt for details.
983 gst_pad_set_activatepull_function (GstPad * pad,
984 GstPadActivateModeFunction activatepull)
986 g_return_if_fail (GST_IS_PAD (pad));
988 GST_PAD_ACTIVATEPULLFUNC (pad) = activatepull;
989 GST_CAT_DEBUG (GST_CAT_PADS, "activatepullfunc for %s:%s set to %s",
990 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (activatepull));
994 * gst_pad_set_activatepush_function:
995 * @pad: a sink #GstPad.
996 * @activatepush: the #GstPadActivateModeFunction to set.
998 * Sets the given activate_push function for the pad. An activate_push function
999 * prepares the element for pushing. See XXX part-activation.txt for details.
1002 gst_pad_set_activatepush_function (GstPad * pad,
1003 GstPadActivateModeFunction activatepush)
1005 g_return_if_fail (GST_IS_PAD (pad));
1007 GST_PAD_ACTIVATEPUSHFUNC (pad) = activatepush;
1008 GST_CAT_DEBUG (GST_CAT_PADS, "activatepushfunc for %s:%s set to %s",
1009 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (activatepush));
1013 * gst_pad_set_chain_function:
1014 * @pad: a sink #GstPad.
1015 * @chain: the #GstPadChainFunction to set.
1017 * Sets the given chain function for the pad. The chain function is called to
1018 * process a #GstBuffer input buffer.
1021 gst_pad_set_chain_function (GstPad * pad, GstPadChainFunction chain)
1023 g_return_if_fail (GST_IS_PAD (pad));
1024 g_return_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SINK);
1026 GST_PAD_CHAINFUNC (pad) = chain;
1027 GST_CAT_DEBUG (GST_CAT_PADS, "chainfunc for %s:%s set to %s",
1028 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (chain));
1032 * gst_pad_set_getrange_function:
1033 * @pad: a source #GstPad.
1034 * @get: the #GstPadGetRangeFunction to set.
1036 * Sets the given getrange function for the pad. The getrange function is called to
1037 * produce a new #GstBuffer to start the processing pipeline. Getrange functions cannot
1041 gst_pad_set_getrange_function (GstPad * pad, GstPadGetRangeFunction get)
1043 g_return_if_fail (GST_IS_PAD (pad));
1044 g_return_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SRC);
1046 GST_PAD_GETRANGEFUNC (pad) = get;
1048 GST_CAT_DEBUG (GST_CAT_PADS, "getrangefunc for %s:%s set to %s",
1049 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (get));
1053 * gst_pad_set_checkgetrange_function:
1054 * @pad: a source #GstPad.
1055 * @check: the #GstPadCheckGetRangeFunction to set.
1057 * Sets the given checkgetrange function for the pad. Implement this function on
1058 * a pad if you dynamically support getrange based scheduling on the pad.
1061 gst_pad_set_checkgetrange_function (GstPad * pad,
1062 GstPadCheckGetRangeFunction check)
1064 g_return_if_fail (GST_IS_PAD (pad));
1065 g_return_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SRC);
1067 GST_PAD_CHECKGETRANGEFUNC (pad) = check;
1069 GST_CAT_DEBUG (GST_CAT_PADS, "checkgetrangefunc for %s:%s set to %s",
1070 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (check));
1074 * gst_pad_set_event_function:
1075 * @pad: a source #GstPad.
1076 * @event: the #GstPadEventFunction to set.
1078 * Sets the given event handler for the pad.
1081 gst_pad_set_event_function (GstPad * pad, GstPadEventFunction event)
1083 g_return_if_fail (GST_IS_PAD (pad));
1085 GST_PAD_EVENTFUNC (pad) = event;
1087 GST_CAT_DEBUG (GST_CAT_PADS, "eventfunc for %s:%s set to %s",
1088 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (event));
1092 * gst_pad_set_query_function:
1093 * @pad: a #GstPad of either direction.
1094 * @query: the #GstPadQueryFunction to set.
1096 * Set the given query function for the pad.
1099 gst_pad_set_query_function (GstPad * pad, GstPadQueryFunction query)
1101 g_return_if_fail (GST_IS_PAD (pad));
1103 GST_PAD_QUERYFUNC (pad) = query;
1105 GST_CAT_DEBUG (GST_CAT_PADS, "queryfunc for %s:%s set to %s",
1106 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (query));
1110 * gst_pad_set_query_type_function:
1111 * @pad: a #GstPad of either direction.
1112 * @type_func: the #GstPadQueryTypeFunction to set.
1114 * Set the given query type function for the pad.
1117 gst_pad_set_query_type_function (GstPad * pad,
1118 GstPadQueryTypeFunction type_func)
1120 g_return_if_fail (GST_IS_PAD (pad));
1122 GST_PAD_QUERYTYPEFUNC (pad) = type_func;
1124 GST_CAT_DEBUG (GST_CAT_PADS, "querytypefunc for %s:%s set to %s",
1125 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (type_func));
1129 * gst_pad_get_query_types:
1132 * Get an array of supported queries that can be performed
1135 * Returns: a zero-terminated array of #GstQueryType.
1137 const GstQueryType *
1138 gst_pad_get_query_types (GstPad * pad)
1140 GstPadQueryTypeFunction func;
1142 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
1144 if (G_UNLIKELY ((func = GST_PAD_QUERYTYPEFUNC (pad)) == NULL))
1156 gst_pad_get_query_types_dispatcher (GstPad * pad, const GstQueryType ** data)
1158 *data = gst_pad_get_query_types (pad);
1164 * gst_pad_get_query_types_default:
1167 * Invoke the default dispatcher for the query types on
1170 * Returns: an zero-terminated array of #GstQueryType, or NULL if none of the
1171 * internally-linked pads has a query types function.
1173 const GstQueryType *
1174 gst_pad_get_query_types_default (GstPad * pad)
1176 GstQueryType *result = NULL;
1178 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
1180 gst_pad_dispatcher (pad, (GstPadDispatcherFunction)
1181 gst_pad_get_query_types_dispatcher, &result);
1187 * gst_pad_set_internal_link_function:
1188 * @pad: a #GstPad of either direction.
1189 * @intlink: the #GstPadIntLinkFunction to set.
1191 * Sets the given internal link function for the pad.
1194 gst_pad_set_internal_link_function (GstPad * pad, GstPadIntLinkFunction intlink)
1196 g_return_if_fail (GST_IS_PAD (pad));
1198 GST_PAD_INTLINKFUNC (pad) = intlink;
1199 GST_CAT_DEBUG (GST_CAT_PADS, "internal link for %s:%s set to %s",
1200 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (intlink));
1204 * gst_pad_set_link_function:
1206 * @link: the #GstPadLinkFunction to set.
1208 * Sets the given link function for the pad. It will be called when
1209 * the pad is linked with another pad.
1211 * The return value GST_PAD_LINK_OK should be used when the connection can be
1214 * The return value GST_PAD_LINK_REFUSED should be used when the connection
1215 * cannot be made for some reason.
1218 gst_pad_set_link_function (GstPad * pad, GstPadLinkFunction link)
1220 g_return_if_fail (GST_IS_PAD (pad));
1222 GST_PAD_LINKFUNC (pad) = link;
1223 GST_CAT_DEBUG (GST_CAT_PADS, "linkfunc for %s:%s set to %s",
1224 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (link));
1228 * gst_pad_set_unlink_function:
1230 * @unlink: the #GstPadUnlinkFunction to set.
1232 * Sets the given unlink function for the pad. It will be called
1233 * when the pad is unlinked.
1236 gst_pad_set_unlink_function (GstPad * pad, GstPadUnlinkFunction unlink)
1238 g_return_if_fail (GST_IS_PAD (pad));
1240 GST_PAD_UNLINKFUNC (pad) = unlink;
1241 GST_CAT_DEBUG (GST_CAT_PADS, "unlinkfunc for %s:%s set to %s",
1242 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (unlink));
1246 * gst_pad_set_getcaps_function:
1248 * @getcaps: the #GstPadGetCapsFunction to set.
1250 * Sets the given getcaps function for the pad. @getcaps should return the
1251 * allowable caps for a pad in the context of the element's state, its link to
1252 * other elements, and the devices or files it has opened. These caps must be a
1253 * subset of the pad template caps. In the NULL state with no links, @getcaps
1254 * should ideally return the same caps as the pad template. In rare
1255 * circumstances, an object property can affect the caps returned by @getcaps,
1256 * but this is discouraged.
1258 * You do not need to call this function if @pad's allowed caps are always the
1259 * same as the pad template caps. This can only be true if the padtemplate
1260 * has fixed simple caps.
1262 * For most filters, the caps returned by @getcaps is directly affected by the
1263 * allowed caps on other pads. For demuxers and decoders, the caps returned by
1264 * the srcpad's getcaps function is directly related to the stream data. Again,
1265 * @getcaps should return the most specific caps it reasonably can, since this
1266 * helps with autoplugging.
1268 * Note that the return value from @getcaps is owned by the caller, so the caller
1269 * should unref the caps after usage.
1272 gst_pad_set_getcaps_function (GstPad * pad, GstPadGetCapsFunction getcaps)
1274 g_return_if_fail (GST_IS_PAD (pad));
1276 GST_PAD_GETCAPSFUNC (pad) = getcaps;
1277 GST_CAT_DEBUG (GST_CAT_PADS, "getcapsfunc for %s:%s set to %s",
1278 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (getcaps));
1282 * gst_pad_set_acceptcaps_function:
1284 * @acceptcaps: the #GstPadAcceptCapsFunction to set.
1286 * Sets the given acceptcaps function for the pad. The acceptcaps function
1287 * will be called to check if the pad can accept the given caps.
1290 gst_pad_set_acceptcaps_function (GstPad * pad,
1291 GstPadAcceptCapsFunction acceptcaps)
1293 g_return_if_fail (GST_IS_PAD (pad));
1295 GST_PAD_ACCEPTCAPSFUNC (pad) = acceptcaps;
1296 GST_CAT_DEBUG (GST_CAT_PADS, "acceptcapsfunc for %s:%s set to %s",
1297 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (acceptcaps));
1301 * gst_pad_set_fixatecaps_function:
1303 * @fixatecaps: the #GstPadFixateCapsFunction to set.
1305 * Sets the given fixatecaps function for the pad. The fixatecaps function
1306 * will be called whenever the default values for a GstCaps needs to be
1310 gst_pad_set_fixatecaps_function (GstPad * pad,
1311 GstPadFixateCapsFunction fixatecaps)
1313 g_return_if_fail (GST_IS_PAD (pad));
1315 GST_PAD_FIXATECAPSFUNC (pad) = fixatecaps;
1316 GST_CAT_DEBUG (GST_CAT_PADS, "fixatecapsfunc for %s:%s set to %s",
1317 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (fixatecaps));
1321 * gst_pad_set_setcaps_function:
1323 * @setcaps: the #GstPadSetCapsFunction to set.
1325 * Sets the given setcaps function for the pad. The setcaps function
1326 * will be called whenever a buffer with a new media type is pushed or
1327 * pulled from the pad. The pad/element needs to update it's internal
1328 * structures to process the new media type. If this new type is not
1329 * acceptable, the setcaps function should return FALSE.
1332 gst_pad_set_setcaps_function (GstPad * pad, GstPadSetCapsFunction setcaps)
1334 g_return_if_fail (GST_IS_PAD (pad));
1336 GST_PAD_SETCAPSFUNC (pad) = setcaps;
1337 GST_CAT_DEBUG (GST_CAT_PADS, "setcapsfunc for %s:%s set to %s",
1338 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (setcaps));
1342 * gst_pad_set_bufferalloc_function:
1343 * @pad: a sink #GstPad.
1344 * @bufalloc: the #GstPadBufferAllocFunction to set.
1346 * Sets the given bufferalloc function for the pad. Note that the
1347 * bufferalloc function can only be set on sinkpads.
1350 gst_pad_set_bufferalloc_function (GstPad * pad,
1351 GstPadBufferAllocFunction bufalloc)
1353 g_return_if_fail (GST_IS_PAD (pad));
1354 g_return_if_fail (GST_PAD_IS_SINK (pad));
1356 GST_PAD_BUFFERALLOCFUNC (pad) = bufalloc;
1357 GST_CAT_DEBUG (GST_CAT_PADS, "bufferallocfunc for %s:%s set to %s",
1358 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (bufalloc));
1363 * @srcpad: the source #GstPad to unlink.
1364 * @sinkpad: the sink #GstPad to unlink.
1366 * Unlinks the source pad from the sink pad. Will emit the "unlinked" signal on
1369 * Returns: TRUE if the pads were unlinked. This function returns FALSE if
1370 * the pads were not linked together.
1375 gst_pad_unlink (GstPad * srcpad, GstPad * sinkpad)
1377 g_return_val_if_fail (GST_IS_PAD (srcpad), FALSE);
1378 g_return_val_if_fail (GST_IS_PAD (sinkpad), FALSE);
1380 GST_CAT_INFO (GST_CAT_ELEMENT_PADS, "unlinking %s:%s(%p) and %s:%s(%p)",
1381 GST_DEBUG_PAD_NAME (srcpad), srcpad,
1382 GST_DEBUG_PAD_NAME (sinkpad), sinkpad);
1386 if (G_UNLIKELY (GST_PAD_DIRECTION (srcpad) != GST_PAD_SRC))
1391 if (G_UNLIKELY (GST_PAD_DIRECTION (sinkpad) != GST_PAD_SINK))
1394 if (G_UNLIKELY (GST_PAD_PEER (srcpad) != sinkpad))
1395 goto not_linked_together;
1397 if (GST_PAD_UNLINKFUNC (srcpad)) {
1398 GST_PAD_UNLINKFUNC (srcpad) (srcpad);
1400 if (GST_PAD_UNLINKFUNC (sinkpad)) {
1401 GST_PAD_UNLINKFUNC (sinkpad) (sinkpad);
1404 /* first clear peers */
1405 GST_PAD_PEER (srcpad) = NULL;
1406 GST_PAD_PEER (sinkpad) = NULL;
1408 GST_UNLOCK (sinkpad);
1409 GST_UNLOCK (srcpad);
1411 /* fire off a signal to each of the pads telling them
1412 * that they've been unlinked */
1413 g_signal_emit (G_OBJECT (srcpad), gst_pad_signals[PAD_UNLINKED], 0, sinkpad);
1414 g_signal_emit (G_OBJECT (sinkpad), gst_pad_signals[PAD_UNLINKED], 0, srcpad);
1416 GST_CAT_INFO (GST_CAT_ELEMENT_PADS, "unlinked %s:%s and %s:%s",
1417 GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (sinkpad));
1423 g_critical ("pad %s is not a source pad", GST_PAD_NAME (srcpad));
1424 GST_UNLOCK (srcpad);
1429 g_critical ("pad %s is not a sink pad", GST_PAD_NAME (sinkpad));
1430 GST_UNLOCK (sinkpad);
1431 GST_UNLOCK (srcpad);
1434 not_linked_together:
1436 /* we do not emit a warning in this case because unlinking cannot
1437 * be made MT safe.*/
1438 GST_UNLOCK (sinkpad);
1439 GST_UNLOCK (srcpad);
1445 * gst_pad_is_linked:
1446 * @pad: pad to check
1448 * Checks if a @pad is linked to another pad or not.
1450 * Returns: TRUE if the pad is linked, FALSE otherwise.
1455 gst_pad_is_linked (GstPad * pad)
1459 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
1462 result = (GST_PAD_PEER (pad) != NULL);
1468 /* get the caps from both pads and see if the intersection
1471 * This function should be called with the pad LOCK on both
1475 gst_pad_link_check_compatible_unlocked (GstPad * src, GstPad * sink)
1480 srccaps = gst_pad_get_caps_unlocked (src);
1481 sinkcaps = gst_pad_get_caps_unlocked (sink);
1482 GST_CAT_DEBUG (GST_CAT_CAPS, "src caps %" GST_PTR_FORMAT, srccaps);
1483 GST_CAT_DEBUG (GST_CAT_CAPS, "sink caps %" GST_PTR_FORMAT, sinkcaps);
1485 /* if we have caps on both pads we can check the intersection */
1486 if (srccaps && sinkcaps) {
1489 icaps = gst_caps_intersect (srccaps, sinkcaps);
1490 gst_caps_unref (srccaps);
1491 gst_caps_unref (sinkcaps);
1493 GST_CAT_DEBUG (GST_CAT_CAPS,
1494 "intersection caps %p %" GST_PTR_FORMAT, icaps, icaps);
1496 if (!icaps || gst_caps_is_empty (icaps)) {
1497 GST_CAT_DEBUG (GST_CAT_CAPS, "intersection is empty");
1498 gst_caps_unref (icaps);
1501 gst_caps_unref (icaps);
1507 /* check if the grandparents of both pads are the same.
1508 * This check is required so that we don't try to link
1509 * pads from elements in different bins without ghostpads.
1511 * The LOCK should be helt on both pads
1514 gst_pad_link_check_hierarchy (GstPad * src, GstPad * sink)
1516 GstObject *psrc, *psink;
1517 gboolean res = TRUE;
1519 psrc = GST_OBJECT_PARENT (src);
1520 psink = GST_OBJECT_PARENT (sink);
1522 /* if one of the pads has no parent, we allow the link */
1523 if (psrc && psink) {
1524 /* if the parents are the same, we have a loop */
1525 if (psrc == psink) {
1526 GST_CAT_DEBUG (GST_CAT_CAPS, "pads have same parent %" GST_PTR_FORMAT,
1531 /* if they both have a parent, we check the grandparents */
1532 psrc = gst_object_get_parent (psrc);
1533 psink = gst_object_get_parent (psink);
1535 if (psrc != psink) {
1536 /* if they have grandparents but they are not the same */
1537 GST_CAT_DEBUG (GST_CAT_CAPS,
1538 "pads have different grandparents %" GST_PTR_FORMAT " and %"
1539 GST_PTR_FORMAT, psrc, psink);
1543 gst_object_unref (psrc);
1545 gst_object_unref (psink);
1551 /* FIXME leftover from an attempt at refactoring... */
1552 /* call with the two pads unlocked */
1553 static GstPadLinkReturn
1554 gst_pad_link_prepare (GstPad * srcpad, GstPad * sinkpad)
1556 /* generic checks */
1557 g_return_val_if_fail (GST_IS_PAD (srcpad), GST_PAD_LINK_REFUSED);
1558 g_return_val_if_fail (GST_IS_PAD (sinkpad), GST_PAD_LINK_REFUSED);
1560 GST_CAT_INFO (GST_CAT_PADS, "trying to link %s:%s and %s:%s",
1561 GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (sinkpad));
1565 if (G_UNLIKELY (GST_PAD_DIRECTION (srcpad) != GST_PAD_SRC))
1568 if (G_UNLIKELY (GST_PAD_PEER (srcpad) != NULL))
1569 goto src_was_linked;
1573 if (G_UNLIKELY (GST_PAD_DIRECTION (sinkpad) != GST_PAD_SINK))
1576 if (G_UNLIKELY (GST_PAD_PEER (sinkpad) != NULL))
1577 goto sink_was_linked;
1579 /* check hierarchy, pads can only be linked if the grandparents
1581 if (!gst_pad_link_check_hierarchy (srcpad, sinkpad))
1582 goto wrong_hierarchy;
1584 /* check pad caps for non-empty intersection */
1585 if (!gst_pad_link_check_compatible_unlocked (srcpad, sinkpad))
1588 /* FIXME check pad scheduling for non-empty intersection */
1590 return GST_PAD_LINK_OK;
1594 g_critical ("pad %s is not a source pad", GST_PAD_NAME (srcpad));
1595 GST_UNLOCK (srcpad);
1596 return GST_PAD_LINK_WRONG_DIRECTION;
1600 GST_CAT_INFO (GST_CAT_PADS, "src %s:%s was linked",
1601 GST_DEBUG_PAD_NAME (srcpad));
1602 /* we do not emit a warning in this case because unlinking cannot
1603 * be made MT safe.*/
1604 GST_UNLOCK (srcpad);
1605 return GST_PAD_LINK_WAS_LINKED;
1609 g_critical ("pad %s is not a sink pad", GST_PAD_NAME (sinkpad));
1610 GST_UNLOCK (sinkpad);
1611 GST_UNLOCK (srcpad);
1612 return GST_PAD_LINK_WRONG_DIRECTION;
1616 GST_CAT_INFO (GST_CAT_PADS, "sink %s:%s was linked",
1617 GST_DEBUG_PAD_NAME (sinkpad));
1618 /* we do not emit a warning in this case because unlinking cannot
1619 * be made MT safe.*/
1620 GST_UNLOCK (sinkpad);
1621 GST_UNLOCK (srcpad);
1622 return GST_PAD_LINK_WAS_LINKED;
1626 GST_CAT_INFO (GST_CAT_PADS, "pads have wrong hierarchy");
1627 GST_UNLOCK (sinkpad);
1628 GST_UNLOCK (srcpad);
1629 return GST_PAD_LINK_WRONG_HIERARCHY;
1633 GST_CAT_INFO (GST_CAT_PADS, "caps are incompatible");
1634 GST_UNLOCK (sinkpad);
1635 GST_UNLOCK (srcpad);
1636 return GST_PAD_LINK_NOFORMAT;
1642 * @srcpad: the source #GstPad to link.
1643 * @sinkpad: the sink #GstPad to link.
1645 * Links the source pad and the sink pad.
1647 * Returns: A result code indicating if the connection worked or
1653 gst_pad_link (GstPad * srcpad, GstPad * sinkpad)
1655 GstPadLinkReturn result;
1657 /* prepare will also lock the two pads */
1658 result = gst_pad_link_prepare (srcpad, sinkpad);
1660 if (result != GST_PAD_LINK_OK)
1661 goto prepare_failed;
1663 GST_UNLOCK (sinkpad);
1664 GST_UNLOCK (srcpad);
1666 /* FIXME released the locks here, concurrent thread might link
1667 * something else. */
1668 if (GST_PAD_LINKFUNC (srcpad)) {
1669 /* this one will call the peer link function */
1670 result = GST_PAD_LINKFUNC (srcpad) (srcpad, sinkpad);
1671 } else if (GST_PAD_LINKFUNC (sinkpad)) {
1672 /* if no source link function, we need to call the sink link
1673 * function ourselves. */
1674 result = GST_PAD_LINKFUNC (sinkpad) (sinkpad, srcpad);
1676 result = GST_PAD_LINK_OK;
1682 if (result == GST_PAD_LINK_OK) {
1683 GST_PAD_PEER (srcpad) = sinkpad;
1684 GST_PAD_PEER (sinkpad) = srcpad;
1686 GST_UNLOCK (sinkpad);
1687 GST_UNLOCK (srcpad);
1689 /* fire off a signal to each of the pads telling them
1690 * that they've been linked */
1691 g_signal_emit (G_OBJECT (srcpad), gst_pad_signals[PAD_LINKED], 0, sinkpad);
1692 g_signal_emit (G_OBJECT (sinkpad), gst_pad_signals[PAD_LINKED], 0, srcpad);
1694 GST_CAT_INFO (GST_CAT_PADS, "linked %s:%s and %s:%s, successful",
1695 GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (sinkpad));
1697 GST_CAT_INFO (GST_CAT_PADS, "link between %s:%s and %s:%s failed",
1698 GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (sinkpad));
1700 GST_UNLOCK (sinkpad);
1701 GST_UNLOCK (srcpad);
1712 gst_pad_set_pad_template (GstPad * pad, GstPadTemplate * templ)
1714 /* this function would need checks if it weren't static */
1717 gst_object_replace ((GstObject **) & pad->padtemplate, (GstObject *) templ);
1721 gst_pad_template_pad_created (templ, pad);
1725 * gst_pad_get_pad_template:
1728 * Gets the template for @pad.
1730 * Returns: the #GstPadTemplate from which this pad was instantiated, or %NULL
1731 * if this pad has no template.
1733 * FIXME: currently returns an unrefcounted padtemplate.
1736 gst_pad_get_pad_template (GstPad * pad)
1738 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
1740 return GST_PAD_PAD_TEMPLATE (pad);
1744 /* should be called with the pad LOCK held */
1745 /* refs the caps, so caller is responsible for getting it unreffed */
1747 gst_pad_get_caps_unlocked (GstPad * pad)
1749 GstCaps *result = NULL;
1751 GST_CAT_DEBUG (GST_CAT_CAPS, "get pad caps of %s:%s (%p)",
1752 GST_DEBUG_PAD_NAME (pad), pad);
1754 if (GST_PAD_GETCAPSFUNC (pad)) {
1755 GST_CAT_DEBUG (GST_CAT_CAPS, "dispatching to pad getcaps function");
1757 GST_OBJECT_FLAG_SET (pad, GST_PAD_IN_GETCAPS);
1759 result = GST_PAD_GETCAPSFUNC (pad) (pad);
1761 GST_OBJECT_FLAG_UNSET (pad, GST_PAD_IN_GETCAPS);
1763 if (result == NULL) {
1764 g_critical ("pad %s:%s returned NULL caps from getcaps function",
1765 GST_DEBUG_PAD_NAME (pad));
1767 GST_CAT_DEBUG (GST_CAT_CAPS,
1768 "pad getcaps %s:%s returned %" GST_PTR_FORMAT,
1769 GST_DEBUG_PAD_NAME (pad), result);
1770 #ifndef G_DISABLE_ASSERT
1771 /* check that the returned caps are a real subset of the template caps */
1772 if (GST_PAD_PAD_TEMPLATE (pad)) {
1773 const GstCaps *templ_caps =
1774 GST_PAD_TEMPLATE_CAPS (GST_PAD_PAD_TEMPLATE (pad));
1775 if (!gst_caps_is_subset (result, templ_caps)) {
1778 GST_CAT_ERROR_OBJECT (GST_CAT_CAPS, pad,
1779 "pad returned caps %" GST_PTR_FORMAT
1780 " which are not a real subset of its template caps %"
1781 GST_PTR_FORMAT, result, templ_caps);
1783 ("pad %s:%s returned caps that are not a real subset of its template caps",
1784 GST_DEBUG_PAD_NAME (pad));
1785 temp = gst_caps_intersect (templ_caps, result);
1786 gst_caps_unref (result);
1794 if (GST_PAD_PAD_TEMPLATE (pad)) {
1795 GstPadTemplate *templ = GST_PAD_PAD_TEMPLATE (pad);
1797 result = GST_PAD_TEMPLATE_CAPS (templ);
1798 GST_CAT_DEBUG (GST_CAT_CAPS,
1799 "using pad template %p with caps %p %" GST_PTR_FORMAT, templ, result,
1802 result = gst_caps_ref (result);
1805 if (GST_PAD_CAPS (pad)) {
1806 result = GST_PAD_CAPS (pad);
1808 GST_CAT_DEBUG (GST_CAT_CAPS,
1809 "using pad caps %p %" GST_PTR_FORMAT, result, result);
1811 result = gst_caps_ref (result);
1815 GST_CAT_DEBUG (GST_CAT_CAPS, "pad has no caps");
1816 result = gst_caps_new_empty ();
1824 * @pad: a #GstPad to get the capabilities of.
1826 * Gets the capabilities this pad can produce or consume.
1827 * Note that this method doesn't necessarily returns the caps set by
1828 * #gst_pad_set_caps - use #GST_PAD_CAPS for that instead.
1829 * gst_pad_get_caps returns all possible caps a pad can operate with, using
1830 * the pad's get_caps function;
1831 * this returns the pad template caps if not explicitly set.
1833 * Returns: a newly allocated copy of the #GstCaps of this pad.
1838 gst_pad_get_caps (GstPad * pad)
1840 GstCaps *result = NULL;
1842 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
1846 GST_CAT_DEBUG (GST_CAT_CAPS, "get pad caps of %s:%s (%p)",
1847 GST_DEBUG_PAD_NAME (pad), pad);
1849 if (G_UNLIKELY (GST_PAD_IS_IN_GETCAPS (pad)))
1850 goto was_dispatching;
1852 result = gst_pad_get_caps_unlocked (pad);
1859 GST_CAT_DEBUG (GST_CAT_CAPS,
1860 "pad %s:%s is already dispatching!", GST_DEBUG_PAD_NAME (pad));
1861 g_warning ("pad %s:%s recursively called getcaps!",
1862 GST_DEBUG_PAD_NAME (pad));
1869 * gst_pad_peer_get_caps:
1870 * @pad: a #GstPad to get the peer capabilities of.
1872 * Gets the capabilities of the peer connected to this pad.
1874 * Returns: the #GstCaps of the peer pad. This function returns a new caps, so use
1875 * gst_caps_unref to get rid of it. this function returns NULL if there is no
1876 * peer pad or when this function is called recursively from a getcaps function.
1879 gst_pad_peer_get_caps (GstPad * pad)
1882 GstCaps *result = NULL;
1884 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
1888 GST_CAT_DEBUG (GST_CAT_CAPS, "get peer caps of %s:%s (%p)",
1889 GST_DEBUG_PAD_NAME (pad), pad);
1891 peerpad = GST_PAD_PEER (pad);
1892 if (G_UNLIKELY (peerpad == NULL))
1895 if (G_UNLIKELY (GST_PAD_IS_IN_GETCAPS (peerpad)))
1896 goto was_dispatching;
1898 gst_object_ref (peerpad);
1901 result = gst_pad_get_caps (peerpad);
1903 gst_object_unref (peerpad);
1914 GST_CAT_DEBUG (GST_CAT_CAPS,
1915 "pad %s:%s is already dispatching!", GST_DEBUG_PAD_NAME (pad));
1916 g_warning ("pad %s:%s recursively called getcaps!",
1917 GST_DEBUG_PAD_NAME (pad));
1924 fixate_value (GValue * dest, const GValue * src)
1926 if (G_VALUE_TYPE (src) == GST_TYPE_INT_RANGE) {
1927 g_value_init (dest, G_TYPE_INT);
1928 g_value_set_int (dest, gst_value_get_int_range_min (src));
1929 } else if (G_VALUE_TYPE (src) == GST_TYPE_DOUBLE_RANGE) {
1930 g_value_init (dest, G_TYPE_DOUBLE);
1931 g_value_set_double (dest, gst_value_get_double_range_min (src));
1932 } else if (G_VALUE_TYPE (src) == GST_TYPE_LIST) {
1933 GValue temp = { 0 };
1935 gst_value_init_and_copy (&temp, gst_value_list_get_value (src, 0));
1936 if (!fixate_value (dest, &temp))
1937 gst_value_init_and_copy (dest, &temp);
1938 g_value_unset (&temp);
1939 } else if (G_VALUE_TYPE (src) == GST_TYPE_ARRAY) {
1940 gboolean res = FALSE;
1943 g_value_init (dest, GST_TYPE_ARRAY);
1944 for (n = 0; n < gst_value_list_get_size (src); n++) {
1946 const GValue *orig_kid = gst_value_list_get_value (src, n);
1948 if (!fixate_value (&kid, orig_kid))
1949 gst_value_init_and_copy (&kid, orig_kid);
1952 gst_value_list_append_value (dest, &kid);
1953 g_value_unset (&kid);
1957 g_value_unset (dest);
1968 gst_pad_default_fixate (GQuark field_id, const GValue * value, gpointer data)
1970 GstStructure *s = data;
1973 if (fixate_value (&v, value)) {
1974 gst_structure_id_set_value (s, field_id, &v);
1982 * gst_pad_fixate_caps:
1983 * @pad: a #GstPad to fixate
1984 * @caps: the #GstCaps to fixate
1986 * Fixate a caps on the given pad. Modifies the caps in place, so you should
1987 * make sure that the caps are actually writable (see gst_caps_make_writable()).
1990 gst_pad_fixate_caps (GstPad * pad, GstCaps * caps)
1992 GstPadFixateCapsFunction fixatefunc;
1995 g_return_if_fail (GST_IS_PAD (pad));
1996 g_return_if_fail (caps != NULL);
1998 if (gst_caps_is_fixed (caps))
2001 fixatefunc = GST_PAD_FIXATECAPSFUNC (pad);
2003 fixatefunc (pad, caps);
2006 /* default fixation */
2007 for (n = 0; n < gst_caps_get_size (caps); n++) {
2008 GstStructure *s = gst_caps_get_structure (caps, n);
2010 gst_structure_foreach (s, gst_pad_default_fixate, s);
2015 * gst_pad_accept_caps:
2016 * @pad: a #GstPad to check
2017 * @caps: a #GstCaps to check on the pad
2019 * Check if the given pad accepts the caps.
2021 * Returns: TRUE if the pad can accept the caps.
2024 gst_pad_accept_caps (GstPad * pad, GstCaps * caps)
2027 GstPadAcceptCapsFunction acceptfunc;
2029 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2031 /* any pad can be unnegotiated */
2036 acceptfunc = GST_PAD_ACCEPTCAPSFUNC (pad);
2038 GST_CAT_DEBUG (GST_CAT_CAPS, "pad accept caps of %s:%s (%p)",
2039 GST_DEBUG_PAD_NAME (pad), pad);
2043 /* we can call the function */
2044 result = acceptfunc (pad, caps);
2046 /* else see get the caps and see if it intersects to something
2051 allowed = gst_pad_get_caps (pad);
2053 intersect = gst_caps_intersect (allowed, caps);
2055 result = !gst_caps_is_empty (intersect);
2057 gst_caps_unref (allowed);
2058 gst_caps_unref (intersect);
2067 * gst_pad_peer_accept_caps:
2068 * @pad: a #GstPad to check
2069 * @caps: a #GstCaps to check on the pad
2071 * Check if the given pad accepts the caps.
2073 * Returns: TRUE if the pad can accept the caps.
2076 gst_pad_peer_accept_caps (GstPad * pad, GstCaps * caps)
2081 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2085 GST_CAT_DEBUG (GST_CAT_CAPS, "peer accept caps of %s:%s (%p)",
2086 GST_DEBUG_PAD_NAME (pad), pad);
2088 peerpad = GST_PAD_PEER (pad);
2089 if (G_UNLIKELY (peerpad == NULL))
2092 result = gst_pad_accept_caps (peerpad, caps);
2106 * @pad: a #GstPad to set the capabilities of.
2107 * @caps: a #GstCaps to set.
2109 * Sets the capabilities of this pad. The caps must be fixed. Any previous
2110 * caps on the pad will be unreffed. This function refs the caps so you should
2111 * unref if as soon as you don't need it anymore.
2112 * It is possible to set NULL caps, which will make the pad unnegotiated
2115 * Returns: TRUE if the caps could be set. FALSE if the caps were not fixed
2116 * or bad parameters were provided to this function.
2121 gst_pad_set_caps (GstPad * pad, GstCaps * caps)
2123 GstPadSetCapsFunction setcaps;
2126 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2127 g_return_val_if_fail (caps == NULL || gst_caps_is_fixed (caps), FALSE);
2130 setcaps = GST_PAD_SETCAPSFUNC (pad);
2132 existing = GST_PAD_CAPS (pad);
2133 if (caps == existing)
2134 goto setting_same_caps;
2135 else if (caps && existing && gst_caps_is_equal (caps, existing))
2136 goto setting_same_caps;
2138 /* call setcaps function to configure the pad */
2139 if (setcaps != NULL && caps) {
2140 if (!GST_PAD_IS_IN_SETCAPS (pad)) {
2141 GST_OBJECT_FLAG_SET (pad, GST_PAD_IN_SETCAPS);
2143 if (!setcaps (pad, caps))
2146 GST_OBJECT_FLAG_UNSET (pad, GST_PAD_IN_SETCAPS);
2148 GST_CAT_DEBUG (GST_CAT_CAPS, "pad %s:%s was dispatching",
2149 GST_DEBUG_PAD_NAME (pad));
2153 gst_caps_replace (&GST_PAD_CAPS (pad), caps);
2154 GST_CAT_DEBUG (GST_CAT_CAPS, "%s:%s caps %" GST_PTR_FORMAT,
2155 GST_DEBUG_PAD_NAME (pad), caps);
2158 g_object_notify (G_OBJECT (pad), "caps");
2165 gst_caps_replace (&GST_PAD_CAPS (pad), caps);
2166 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
2167 "caps %" GST_PTR_FORMAT " same as existing, updating ptr only", caps);
2174 GST_OBJECT_FLAG_UNSET (pad, GST_PAD_IN_SETCAPS);
2175 GST_CAT_DEBUG (GST_CAT_CAPS,
2176 "pad %s:%s, caps %" GST_PTR_FORMAT " could not be set",
2177 GST_DEBUG_PAD_NAME (pad), caps);
2185 gst_pad_configure_sink (GstPad * pad, GstCaps * caps)
2187 GstPadAcceptCapsFunction acceptcaps;
2188 GstPadSetCapsFunction setcaps;
2191 acceptcaps = GST_PAD_ACCEPTCAPSFUNC (pad);
2192 setcaps = GST_PAD_SETCAPSFUNC (pad);
2194 /* See if pad accepts the caps, by calling acceptcaps, only
2195 * needed if no setcaps function */
2196 if (setcaps == NULL && acceptcaps != NULL) {
2197 if (!acceptcaps (pad, caps))
2200 /* set caps on pad if call succeeds */
2201 res = gst_pad_set_caps (pad, caps);
2202 /* no need to unref the caps here, set_caps takes a ref and
2203 * our ref goes away when we leave this function. */
2209 GST_CAT_DEBUG (GST_CAT_CAPS, "caps %" GST_PTR_FORMAT " not accepted", caps);
2214 /* returns TRUE if the src pad could be configured to accept the given caps */
2216 gst_pad_configure_src (GstPad * pad, GstCaps * caps)
2218 GstPadAcceptCapsFunction acceptcaps;
2219 GstPadSetCapsFunction setcaps;
2222 acceptcaps = GST_PAD_ACCEPTCAPSFUNC (pad);
2223 setcaps = GST_PAD_SETCAPSFUNC (pad);
2225 /* See if pad accepts the caps, by calling acceptcaps, only
2226 * needed if no setcaps function */
2227 if (setcaps == NULL && acceptcaps != NULL) {
2228 if (!acceptcaps (pad, caps))
2231 /* set caps on pad if call succeeds */
2232 res = gst_pad_set_caps (pad, caps);
2233 /* no need to unref the caps here, set_caps takes a ref and
2234 * our ref goes away when we leave this function. */
2240 GST_CAT_DEBUG (GST_CAT_CAPS, "caps %" GST_PTR_FORMAT " not accepted", caps);
2246 * gst_pad_get_pad_template_caps:
2247 * @pad: a #GstPad to get the template capabilities from.
2249 * Gets the capabilities for @pad's template.
2251 * Returns: the #GstCaps of this pad template. If you intend to keep a reference
2252 * on the caps, make a copy (see gst_caps_copy ()).
2255 gst_pad_get_pad_template_caps (GstPad * pad)
2257 static GstStaticCaps anycaps = GST_STATIC_CAPS ("ANY");
2259 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2261 if (GST_PAD_PAD_TEMPLATE (pad))
2262 return GST_PAD_TEMPLATE_CAPS (GST_PAD_PAD_TEMPLATE (pad));
2264 return gst_static_caps_get (&anycaps);
2270 * @pad: a #GstPad to get the peer of.
2272 * Gets the peer of @pad. This function refs the peer pad so
2273 * you need to unref it after use.
2275 * Returns: the peer #GstPad. Unref after usage.
2280 gst_pad_get_peer (GstPad * pad)
2284 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2287 result = GST_PAD_PEER (pad);
2289 gst_object_ref (result);
2296 * gst_pad_get_allowed_caps:
2297 * @srcpad: a #GstPad, it must a a source pad.
2299 * Gets the capabilities of the allowed media types that can flow through
2300 * @srcpad and its peer. The pad must be a source pad.
2301 * The caller must free the resulting caps.
2303 * Returns: the allowed #GstCaps of the pad link. Free the caps when
2304 * you no longer need it. This function returns NULL when the @srcpad has no
2310 gst_pad_get_allowed_caps (GstPad * srcpad)
2317 g_return_val_if_fail (GST_IS_PAD (srcpad), NULL);
2318 g_return_val_if_fail (GST_PAD_IS_SRC (srcpad), NULL);
2322 peer = GST_PAD_PEER (srcpad);
2323 if (G_UNLIKELY (peer == NULL))
2326 GST_CAT_DEBUG (GST_CAT_PROPERTIES, "%s:%s: getting allowed caps",
2327 GST_DEBUG_PAD_NAME (srcpad));
2329 gst_object_ref (peer);
2330 GST_UNLOCK (srcpad);
2331 mycaps = gst_pad_get_caps (srcpad);
2333 peercaps = gst_pad_get_caps (peer);
2334 gst_object_unref (peer);
2336 caps = gst_caps_intersect (mycaps, peercaps);
2337 gst_caps_unref (peercaps);
2338 gst_caps_unref (mycaps);
2340 GST_CAT_DEBUG (GST_CAT_CAPS, "allowed caps %" GST_PTR_FORMAT, caps);
2346 GST_CAT_DEBUG (GST_CAT_PROPERTIES, "%s:%s: no peer",
2347 GST_DEBUG_PAD_NAME (srcpad));
2348 GST_UNLOCK (srcpad);
2355 * gst_pad_get_negotiated_caps:
2358 * Gets the capabilities of the media type that currently flows through @pad
2361 * This function can be used on both src and sinkpads. Note that srcpads are
2362 * always negotiated before sinkpads so it is possible that the negotiated caps
2363 * on the srcpad do not match the negotiated caps of the peer.
2365 * Returns: the negotiated #GstCaps of the pad link. Free the caps when
2366 * you no longer need it. This function returns NULL when the @pad has no
2367 * peer or is not negotiated yet.
2372 gst_pad_get_negotiated_caps (GstPad * pad)
2377 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2381 if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
2384 GST_CAT_DEBUG (GST_CAT_PROPERTIES, "%s:%s: getting negotiated caps",
2385 GST_DEBUG_PAD_NAME (pad));
2387 caps = GST_PAD_CAPS (pad);
2389 gst_caps_ref (caps);
2392 GST_CAT_DEBUG (GST_CAT_CAPS, "negotiated caps %" GST_PTR_FORMAT, caps);
2398 GST_CAT_DEBUG (GST_CAT_PROPERTIES, "%s:%s: no peer",
2399 GST_DEBUG_PAD_NAME (pad));
2407 * gst_pad_alloc_buffer:
2408 * @pad: a source #GstPad
2409 * @offset: the offset of the new buffer in the stream
2410 * @size: the size of the new buffer
2411 * @caps: the caps of the new buffer
2412 * @buf: a newly allocated buffer
2414 * Allocates a new, empty buffer optimized to push to pad @pad. This
2415 * function only works if @pad is a source pad and has a peer.
2417 * You need to check the caps of the buffer after performing this
2418 * function and renegotiate to the format if needed.
2420 * A new, empty #GstBuffer will be put in the @buf argument.
2422 * Returns: a result code indicating success of the operation. Any
2423 * result code other than GST_FLOW_OK is an error and @buf should
2425 * An error can occur if the pad is not connected or when the downstream
2426 * peer elements cannot provide an acceptable buffer.
2431 gst_pad_alloc_buffer (GstPad * pad, guint64 offset, gint size, GstCaps * caps,
2436 GstPadBufferAllocFunction bufferallocfunc;
2437 gboolean caps_changed;
2439 g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
2440 g_return_val_if_fail (GST_PAD_IS_SRC (pad), GST_FLOW_ERROR);
2441 g_return_val_if_fail (buf != NULL, GST_FLOW_ERROR);
2444 while (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad)))
2445 handle_pad_block (pad);
2447 if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
2450 gst_object_ref (peer);
2453 if (G_LIKELY ((bufferallocfunc = peer->bufferallocfunc) == NULL))
2457 /* when the peer is flushing we cannot give a buffer */
2458 if (G_UNLIKELY (GST_PAD_IS_FLUSHING (peer)))
2461 if (offset == GST_BUFFER_OFFSET_NONE) {
2462 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
2463 "calling bufferallocfunc &%s (@%p) of peer pad %s:%s for size %d offset NONE",
2464 GST_DEBUG_FUNCPTR_NAME (bufferallocfunc),
2465 &bufferallocfunc, GST_DEBUG_PAD_NAME (peer), size);
2467 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
2468 "calling bufferallocfunc &%s (@%p) of peer pad %s:%s for size %d offset %"
2469 G_GUINT64_FORMAT, GST_DEBUG_FUNCPTR_NAME (bufferallocfunc),
2470 &bufferallocfunc, GST_DEBUG_PAD_NAME (peer), size, offset);
2474 ret = bufferallocfunc (peer, offset, size, caps, buf);
2476 if (G_UNLIKELY (ret != GST_FLOW_OK))
2478 if (G_UNLIKELY (*buf == NULL))
2481 /* If the buffer alloc function didn't set up the caps like it should,
2483 if (caps && (GST_BUFFER_CAPS (*buf) == NULL)) {
2484 GST_WARNING ("Buffer allocation function for pad % " GST_PTR_FORMAT
2485 " did not set up caps. Setting", peer);
2487 gst_buffer_set_caps (*buf, caps);
2491 gst_object_unref (peer);
2493 /* FIXME, move capnego this into a base class? */
2494 caps = GST_BUFFER_CAPS (*buf);
2495 caps_changed = caps && caps != GST_PAD_CAPS (pad);
2496 /* we got a new datatype on the pad, see if it can handle it */
2497 if (G_UNLIKELY (caps_changed)) {
2498 GST_DEBUG ("caps changed to %" GST_PTR_FORMAT, caps);
2499 if (G_UNLIKELY (!gst_pad_configure_src (pad, caps)))
2500 goto not_negotiated;
2506 /* pad has no peer */
2507 GST_CAT_DEBUG (GST_CAT_PADS,
2508 "%s:%s called bufferallocfunc but had no peer",
2509 GST_DEBUG_PAD_NAME (pad));
2511 return GST_FLOW_NOT_LINKED;
2515 /* peer was flushing */
2517 gst_object_unref (peer);
2518 GST_CAT_DEBUG (GST_CAT_PADS,
2519 "%s:%s called bufferallocfunc but peer was flushing",
2520 GST_DEBUG_PAD_NAME (pad));
2521 return GST_FLOW_WRONG_STATE;
2523 /* fallback case, allocate a buffer of our own, add pad caps. */
2526 GST_CAT_DEBUG (GST_CAT_PADS,
2527 "%s:%s fallback buffer alloc", GST_DEBUG_PAD_NAME (pad));
2528 *buf = gst_buffer_new_and_alloc (size);
2529 GST_BUFFER_OFFSET (*buf) = offset;
2530 gst_buffer_set_caps (*buf, caps);
2538 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
2539 "alloc function retured unacceptable buffer");
2540 return GST_FLOW_NOT_NEGOTIATED;
2544 gst_object_unref (peer);
2545 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
2546 "alloc function retured error %s", gst_flow_get_name (ret));
2552 * gst_pad_get_internal_links_default:
2553 * @pad: the #GstPad to get the internal links of.
2555 * Gets a list of pads to which the given pad is linked to
2556 * inside of the parent element.
2557 * This is the default handler, and thus returns a list of all of the
2558 * pads inside the parent element with opposite direction.
2559 * The caller must free this list after use.
2561 * Returns: a newly allocated #GList of pads, or NULL if the pad has no parent.
2566 gst_pad_get_internal_links_default (GstPad * pad)
2571 GstPadDirection direction;
2573 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2575 direction = pad->direction;
2577 parent = GST_PAD_PARENT (pad);
2581 parent_pads = parent->pads;
2583 while (parent_pads) {
2584 GstPad *parent_pad = GST_PAD_CAST (parent_pads->data);
2586 if (parent_pad->direction != direction) {
2587 res = g_list_prepend (res, parent_pad);
2590 parent_pads = g_list_next (parent_pads);
2597 * gst_pad_get_internal_links:
2598 * @pad: the #GstPad to get the internal links of.
2600 * Gets a list of pads to which the given pad is linked to
2601 * inside of the parent element.
2602 * The caller must free this list after use.
2604 * Returns: a newly allocated #GList of pads.
2609 gst_pad_get_internal_links (GstPad * pad)
2613 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2615 if (GST_PAD_INTLINKFUNC (pad))
2616 res = GST_PAD_INTLINKFUNC (pad) (pad);
2623 gst_pad_event_default_dispatch (GstPad * pad, GstEvent * event)
2628 GST_INFO_OBJECT (pad, "Sending event %p to all internally linked pads",
2631 result = (GST_PAD_DIRECTION (pad) == GST_PAD_SINK);
2633 orig = pads = gst_pad_get_internal_links (pad);
2636 GstPad *eventpad = GST_PAD_CAST (pads->data);
2638 pads = g_list_next (pads);
2640 if (GST_PAD_DIRECTION (eventpad) == GST_PAD_SRC) {
2641 /* for each pad we send to, we should ref the event; it's up
2642 * to downstream to unref again when handled. */
2643 GST_LOG_OBJECT (pad, "Reffing and sending event %p (%s) to %s:%s",
2644 event, gst_event_type_get_name (GST_EVENT_TYPE (event)),
2645 GST_DEBUG_PAD_NAME (eventpad));
2646 gst_event_ref (event);
2647 gst_pad_push_event (eventpad, event);
2649 /* we only send the event on one pad, multi-sinkpad elements
2650 * should implement a handler */
2651 GST_LOG_OBJECT (pad, "sending event %p (%s) to one sink pad %s:%s",
2652 event, gst_event_type_get_name (GST_EVENT_TYPE (event)),
2653 GST_DEBUG_PAD_NAME (eventpad));
2654 result = gst_pad_push_event (eventpad, event);
2658 /* we handled the incoming event so we unref once */
2659 GST_LOG_OBJECT (pad, "handled event %p, unreffing", event);
2660 gst_event_unref (event);
2669 * gst_pad_event_default:
2670 * @pad: a #GstPad to call the default event handler on.
2671 * @event: the #GstEvent to handle.
2673 * Invokes the default event handler for the given pad. End-of-stream and
2674 * discontinuity events are handled specially, and then the event is sent to all
2675 * pads internally linked to @pad. Note that if there are many possible sink
2676 * pads that are internally linked to @pad, only one will be sent an event.
2677 * Multi-sinkpad elements should implement custom event handlers.
2679 * Returns: TRUE if the event was sent succesfully.
2682 gst_pad_event_default (GstPad * pad, GstEvent * event)
2684 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2685 g_return_val_if_fail (event != NULL, FALSE);
2687 switch (GST_EVENT_TYPE (event)) {
2690 GST_DEBUG_OBJECT (pad, "pausing task because of eos");
2691 gst_pad_pause_task (pad);
2697 return gst_pad_event_default_dispatch (pad, event);
2701 * gst_pad_dispatcher:
2702 * @pad: a #GstPad to dispatch.
2703 * @dispatch: the #GstDispatcherFunction to call.
2704 * @data: gpointer user data passed to the dispatcher function.
2706 * Invokes the given dispatcher function on all pads that are
2707 * internally linked to the given pad.
2708 * The GstPadDispatcherFunction should return TRUE when no further pads
2709 * need to be processed.
2711 * Returns: TRUE if one of the dispatcher functions returned TRUE.
2714 gst_pad_dispatcher (GstPad * pad, GstPadDispatcherFunction dispatch,
2717 gboolean res = FALSE;
2718 GList *int_pads, *orig;
2720 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2721 g_return_val_if_fail (dispatch != NULL, FALSE);
2723 orig = int_pads = gst_pad_get_internal_links (pad);
2726 GstPad *int_pad = GST_PAD_CAST (int_pads->data);
2727 GstPad *int_peer = GST_PAD_PEER (int_pad);
2730 res = dispatch (int_peer, data);
2734 int_pads = g_list_next (int_pads);
2744 * @pad: a #GstPad to invoke the default query on.
2745 * @query: the #GstQuery to perform.
2747 * Dispatches a query to a pad. The query should have been allocated by the
2748 * caller via one of the type-specific allocation functions in gstquery.h. The
2749 * element is responsible for filling the query with an appropriate response,
2750 * which should then be parsed with a type-specific query parsing function.
2752 * Again, the caller is responsible for both the allocation and deallocation of
2753 * the query structure.
2755 * Returns: TRUE if the query could be performed.
2758 gst_pad_query (GstPad * pad, GstQuery * query)
2760 GstPadQueryFunction func;
2762 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2763 g_return_val_if_fail (GST_IS_QUERY (query), FALSE);
2765 GST_DEBUG ("sending query %p to pad %s:%s", query, GST_DEBUG_PAD_NAME (pad));
2767 if ((func = GST_PAD_QUERYFUNC (pad)) == NULL)
2770 return func (pad, query);
2774 GST_DEBUG ("pad had no query function");
2780 * gst_pad_query_default:
2781 * @pad: a #GstPad to call the default query handler on.
2782 * @query: the #GstQuery to handle.
2784 * Invokes the default query handler for the given pad.
2785 * The query is sent to all pads internally linked to @pad. Note that
2786 * if there are many possible sink pads that are internally linked to
2787 * @pad, only one will be sent the query.
2788 * Multi-sinkpad elements should implement custom query handlers.
2790 * Returns: TRUE if the query was performed succesfully.
2793 gst_pad_query_default (GstPad * pad, GstQuery * query)
2795 switch (GST_QUERY_TYPE (query)) {
2796 case GST_QUERY_POSITION:
2797 case GST_QUERY_SEEKING:
2798 case GST_QUERY_FORMATS:
2799 case GST_QUERY_LATENCY:
2800 case GST_QUERY_JITTER:
2801 case GST_QUERY_RATE:
2802 case GST_QUERY_CONVERT:
2804 return gst_pad_dispatcher
2805 (pad, (GstPadDispatcherFunction) gst_pad_query, query);
2809 #ifndef GST_DISABLE_LOADSAVE
2810 /* FIXME: why isn't this on a GstElement ? */
2812 * gst_pad_load_and_link:
2813 * @self: an #xmlNodePtr to read the description from.
2814 * @parent: the #GstObject element that owns the pad.
2816 * Reads the pad definition from the XML node and links the given pad
2817 * in the element to a pad of an element up in the hierarchy.
2820 gst_pad_load_and_link (xmlNodePtr self, GstObject * parent)
2822 xmlNodePtr field = self->xmlChildrenNode;
2823 GstPad *pad = NULL, *targetpad;
2827 GstObject *grandparent;
2831 if (!strcmp ((char *) field->name, "name")) {
2832 name = (gchar *) xmlNodeGetContent (field);
2833 pad = gst_element_get_pad (GST_ELEMENT (parent), name);
2835 } else if (!strcmp ((char *) field->name, "peer")) {
2836 peer = (gchar *) xmlNodeGetContent (field);
2838 field = field->next;
2840 g_return_if_fail (pad != NULL);
2845 split = g_strsplit (peer, ".", 2);
2847 if (split[0] == NULL || split[1] == NULL) {
2848 GST_CAT_DEBUG (GST_CAT_XML,
2849 "Could not parse peer '%s' for pad %s:%s, leaving unlinked",
2850 peer, GST_DEBUG_PAD_NAME (pad));
2857 g_return_if_fail (split[0] != NULL);
2858 g_return_if_fail (split[1] != NULL);
2860 grandparent = gst_object_get_parent (parent);
2862 if (grandparent && GST_IS_BIN (grandparent)) {
2863 target = gst_bin_get_by_name_recurse_up (GST_BIN (grandparent), split[0]);
2870 targetpad = gst_element_get_pad (target, split[1]);
2872 if (targetpad == NULL)
2875 gst_pad_link (pad, targetpad);
2882 * gst_pad_save_thyself:
2883 * @pad: a #GstPad to save.
2884 * @parent: the parent #xmlNodePtr to save the description in.
2886 * Saves the pad into an xml representation.
2888 * Returns: the #xmlNodePtr representation of the pad.
2891 gst_pad_save_thyself (GstObject * object, xmlNodePtr parent)
2896 g_return_val_if_fail (GST_IS_PAD (object), NULL);
2898 pad = GST_PAD (object);
2900 xmlNewChild (parent, NULL, (xmlChar *) "name",
2901 (xmlChar *) GST_PAD_NAME (pad));
2902 if (GST_PAD_PEER (pad) != NULL) {
2905 peer = GST_PAD_PEER (pad);
2906 /* first check to see if the peer's parent's parent is the same */
2907 /* we just save it off */
2908 content = g_strdup_printf ("%s.%s",
2909 GST_OBJECT_NAME (GST_PAD_PARENT (peer)), GST_PAD_NAME (peer));
2910 xmlNewChild (parent, NULL, (xmlChar *) "peer", (xmlChar *) content);
2913 xmlNewChild (parent, NULL, (xmlChar *) "peer", NULL);
2920 * gst_ghost_pad_save_thyself:
2921 * @pad: a ghost #GstPad to save.
2922 * @parent: the parent #xmlNodePtr to save the description in.
2924 * Saves the ghost pad into an xml representation.
2926 * Returns: the #xmlNodePtr representation of the pad.
2929 gst_ghost_pad_save_thyself (GstPad * pad, xmlNodePtr parent)
2933 g_return_val_if_fail (GST_IS_GHOST_PAD (pad), NULL);
2935 self = xmlNewChild (parent, NULL, (xmlChar *) "ghostpad", NULL);
2936 xmlNewChild (self, NULL, (xmlChar *) "name", (xmlChar *) GST_PAD_NAME (pad));
2937 xmlNewChild (self, NULL, (xmlChar *) "parent",
2938 (xmlChar *) GST_OBJECT_NAME (GST_PAD_PARENT (pad)));
2940 /* FIXME FIXME FIXME! */
2945 #endif /* GST_DISABLE_LOADSAVE */
2948 * should be called with pad lock held
2953 handle_pad_block (GstPad * pad)
2955 GstPadBlockCallback callback;
2958 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
2959 "signal block taken on pad %s:%s", GST_DEBUG_PAD_NAME (pad));
2961 /* need to grab extra ref for the callbacks */
2962 gst_object_ref (pad);
2964 callback = pad->block_callback;
2966 user_data = pad->block_data;
2968 callback (pad, TRUE, user_data);
2971 GST_PAD_BLOCK_SIGNAL (pad);
2974 while (GST_PAD_IS_BLOCKED (pad))
2975 GST_PAD_BLOCK_WAIT (pad);
2977 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "got unblocked");
2979 callback = pad->block_callback;
2981 user_data = pad->block_data;
2983 callback (pad, FALSE, user_data);
2986 GST_PAD_BLOCK_SIGNAL (pad);
2989 gst_object_unref (pad);
2992 /**********************************************************************
2993 * Data passing functions
2997 gst_pad_emit_have_data_signal (GstPad * pad, GstMiniObject * obj)
3000 GValue args[2] = { {0}, {0} };
3005 g_value_init (&ret, G_TYPE_BOOLEAN);
3006 g_value_set_boolean (&ret, TRUE);
3007 g_value_init (&args[0], GST_TYPE_PAD);
3008 g_value_set_object (&args[0], pad);
3009 g_value_init (&args[1], GST_TYPE_MINI_OBJECT); // G_TYPE_POINTER);
3010 gst_value_set_mini_object (&args[1], obj);
3012 if (GST_IS_EVENT (obj))
3013 detail = event_quark;
3015 detail = buffer_quark;
3018 g_signal_emitv (args, gst_pad_signals[PAD_HAVE_DATA], detail, &ret);
3019 res = g_value_get_boolean (&ret);
3022 g_value_unset (&ret);
3023 g_value_unset (&args[0]);
3024 g_value_unset (&args[1]);
3031 * @pad: a sink #GstPad.
3032 * @buffer: the #GstBuffer to send.
3034 * Chain a buffer to @pad.
3036 * Returns: a #GstFlowReturn from the pad.
3041 gst_pad_chain (GstPad * pad, GstBuffer * buffer)
3044 gboolean caps_changed;
3045 GstPadChainFunction chainfunc;
3047 gboolean emit_signal;
3049 g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
3050 g_return_val_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SINK,
3052 g_return_val_if_fail (buffer != NULL, GST_FLOW_ERROR);
3053 g_return_val_if_fail (GST_IS_BUFFER (buffer), GST_FLOW_ERROR);
3055 GST_STREAM_LOCK (pad);
3058 if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad)))
3061 caps = GST_BUFFER_CAPS (buffer);
3062 caps_changed = caps && caps != GST_PAD_CAPS (pad);
3064 emit_signal = GST_PAD_DO_BUFFER_SIGNALS (pad) > 0;
3067 /* see if the signal should be emited, we emit before caps nego as
3068 * we might drop the buffer and do capsnego for nothing. */
3069 if (G_UNLIKELY (emit_signal)) {
3070 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (buffer)))
3074 /* we got a new datatype on the pad, see if it can handle it */
3075 if (G_UNLIKELY (caps_changed)) {
3076 GST_DEBUG ("caps changed to %" GST_PTR_FORMAT, caps);
3077 if (G_UNLIKELY (!gst_pad_configure_sink (pad, caps)))
3078 goto not_negotiated;
3081 /* NOTE: we read the chainfunc unlocked.
3082 * we cannot hold the lock for the pad so we might send
3083 * the data to the wrong function. This is not really a
3084 * problem since functions are assigned at creation time
3085 * and don't change that often... */
3086 if (G_UNLIKELY ((chainfunc = GST_PAD_CHAINFUNC (pad)) == NULL))
3089 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3090 "calling chainfunction &%s of pad %s:%s",
3091 GST_DEBUG_FUNCPTR_NAME (chainfunc), GST_DEBUG_PAD_NAME (pad));
3093 ret = chainfunc (pad, buffer);
3095 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3096 "called chainfunction &%s of pad %s:%s, returned %s",
3097 GST_DEBUG_FUNCPTR_NAME (chainfunc), GST_DEBUG_PAD_NAME (pad),
3098 gst_flow_get_name (ret));
3100 GST_STREAM_UNLOCK (pad);
3107 gst_buffer_unref (buffer);
3108 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3109 "pushing, but pad was flushing");
3111 GST_STREAM_UNLOCK (pad);
3112 return GST_FLOW_WRONG_STATE;
3116 gst_buffer_unref (buffer);
3117 GST_DEBUG_OBJECT (pad, "Dropping buffer due to FALSE probe return");
3118 GST_STREAM_UNLOCK (pad);
3123 gst_buffer_unref (buffer);
3124 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3125 "pushing buffer but pad did not accept");
3126 GST_STREAM_UNLOCK (pad);
3127 return GST_FLOW_NOT_NEGOTIATED;
3131 gst_buffer_unref (buffer);
3132 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3133 "pushing, but not chainhandler");
3134 GST_ELEMENT_ERROR (GST_PAD_PARENT (pad), CORE, PAD, (NULL),
3135 ("push on pad %s:%s but it has no chainfunction",
3136 GST_DEBUG_PAD_NAME (pad)));
3137 GST_STREAM_UNLOCK (pad);
3138 return GST_FLOW_ERROR;
3144 * @pad: a source #GstPad.
3145 * @buffer: the #GstBuffer to push.
3147 * Pushes a buffer to the peer of @pad.
3148 * buffer probes will be triggered before the buffer gets pushed.
3150 * Returns: a #GstFlowReturn from the peer pad.
3155 gst_pad_push (GstPad * pad, GstBuffer * buffer)
3160 g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
3161 g_return_val_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SRC, GST_FLOW_ERROR);
3162 g_return_val_if_fail (buffer != NULL, GST_FLOW_ERROR);
3163 g_return_val_if_fail (GST_IS_BUFFER (buffer), GST_FLOW_ERROR);
3167 /* FIXME: this check can go away; pad_set_blocked could be implemented with
3168 * probes completely */
3169 while (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad)))
3170 handle_pad_block (pad);
3172 /* we emit signals on the pad arg, the peer will have a chance to
3173 * emit in the _chain() function */
3174 if (G_UNLIKELY (GST_PAD_DO_BUFFER_SIGNALS (pad) > 0)) {
3175 /* unlock before emitting */
3178 /* if the signal handler returned FALSE, it means we should just drop the
3180 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (buffer)))
3186 if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
3188 gst_object_ref (peer);
3191 ret = gst_pad_chain (peer, buffer);
3193 gst_object_unref (peer);
3197 /* ERROR recovery here */
3200 gst_buffer_unref (buffer);
3201 GST_DEBUG_OBJECT (pad, "Dropping buffer due to FALSE probe return");
3206 gst_buffer_unref (buffer);
3207 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3208 "pushing, but it was not linked");
3210 return GST_FLOW_NOT_LINKED;
3215 * gst_pad_check_pull_range:
3216 * @pad: a sink #GstPad.
3218 * Checks if a #gst_pad_pull_range() can be performed on the peer
3219 * source pad. This function is used by plugins that want to check
3220 * if they can use random access on the peer source pad.
3222 * The peer sourcepad can implement a custom #GstPadCheckGetRangeFunction
3223 * if it needs to perform some logic to determine if pull_range is
3226 * Returns: a gboolean with the result.
3231 gst_pad_check_pull_range (GstPad * pad)
3235 GstPadCheckGetRangeFunction checkgetrangefunc;
3237 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
3240 if (GST_PAD_DIRECTION (pad) != GST_PAD_SINK)
3241 goto wrong_direction;
3243 if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
3246 gst_object_ref (peer);
3249 /* see note in above function */
3250 if (G_LIKELY ((checkgetrangefunc = peer->checkgetrangefunc) == NULL)) {
3251 /* FIXME, kindoff ghetto */
3252 ret = GST_PAD_GETRANGEFUNC (peer) != NULL;
3254 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3255 "calling checkgetrangefunc %s of peer pad %s:%s",
3256 GST_DEBUG_FUNCPTR_NAME (checkgetrangefunc), GST_DEBUG_PAD_NAME (peer));
3258 ret = checkgetrangefunc (peer);
3261 gst_object_unref (peer);
3265 /* ERROR recovery here */
3273 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3274 "checking pull range, but it was not linked");
3281 * gst_pad_get_range:
3282 * @pad: a src #GstPad.
3283 * @offset: The start offset of the buffer
3284 * @size: The length of the buffer
3285 * @buffer: a pointer to hold the #GstBuffer.
3287 * Calls the getrange function of @pad.
3289 * Returns: a #GstFlowReturn from the pad.
3294 gst_pad_get_range (GstPad * pad, guint64 offset, guint size,
3295 GstBuffer ** buffer)
3298 GstPadGetRangeFunction getrangefunc;
3299 gboolean emit_signal;
3301 g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
3302 g_return_val_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SRC, GST_FLOW_ERROR);
3303 g_return_val_if_fail (buffer != NULL, GST_FLOW_ERROR);
3305 GST_STREAM_LOCK (pad);
3308 if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad)))
3311 emit_signal = GST_PAD_DO_BUFFER_SIGNALS (pad) > 0;
3314 if (G_UNLIKELY ((getrangefunc = GST_PAD_GETRANGEFUNC (pad)) == NULL))
3317 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3318 "calling getrangefunc %s of peer pad %s:%s, offset %"
3319 G_GUINT64_FORMAT ", size %u",
3320 GST_DEBUG_FUNCPTR_NAME (getrangefunc), GST_DEBUG_PAD_NAME (pad),
3323 ret = getrangefunc (pad, offset, size, buffer);
3325 /* can only fire the signal if we have a valid buffer */
3326 if (G_UNLIKELY (emit_signal) && (ret == GST_FLOW_OK)) {
3327 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (*buffer)))
3331 GST_STREAM_UNLOCK (pad);
3338 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3339 "pulling range, but pad was flushing");
3341 GST_STREAM_UNLOCK (pad);
3342 return GST_FLOW_WRONG_STATE;
3346 GST_ELEMENT_ERROR (GST_PAD_PARENT (pad), CORE, PAD, (NULL),
3347 ("pullrange on pad %s:%s but it has no getrangefunction",
3348 GST_DEBUG_PAD_NAME (pad)));
3349 GST_STREAM_UNLOCK (pad);
3350 return GST_FLOW_ERROR;
3354 GST_DEBUG ("Dropping data after FALSE probe return");
3355 GST_STREAM_UNLOCK (pad);
3356 gst_buffer_unref (*buffer);
3358 return GST_FLOW_UNEXPECTED;
3364 * gst_pad_pull_range:
3365 * @pad: a sink #GstPad.
3366 * @offset: The start offset of the buffer
3367 * @size: The length of the buffer
3368 * @buffer: a pointer to hold the #GstBuffer.
3370 * Pulls a buffer from the peer pad. @pad must be a linked
3373 * Returns: a #GstFlowReturn from the peer pad.
3378 gst_pad_pull_range (GstPad * pad, guint64 offset, guint size,
3379 GstBuffer ** buffer)
3383 gboolean emit_signal;
3385 g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
3386 g_return_val_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SINK,
3388 g_return_val_if_fail (buffer != NULL, GST_FLOW_ERROR);
3392 while (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad)))
3393 handle_pad_block (pad);
3395 if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
3398 /* signal emision for the pad, peer has chance to emit when
3399 * we call _get_range() */
3400 emit_signal = GST_PAD_DO_BUFFER_SIGNALS (pad) > 0;
3402 gst_object_ref (peer);
3405 ret = gst_pad_get_range (peer, offset, size, buffer);
3407 gst_object_unref (peer);
3409 /* can only fire the signal if we have a valid buffer */
3410 if (G_UNLIKELY (emit_signal) && (ret == GST_FLOW_OK)) {
3411 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (*buffer)))
3416 /* ERROR recovery here */
3419 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3420 "pulling range, but it was not linked");
3422 return GST_FLOW_NOT_LINKED;
3426 GST_DEBUG ("Dropping data after FALSE probe return");
3427 gst_buffer_unref (*buffer);
3429 return GST_FLOW_UNEXPECTED;
3434 * gst_pad_push_event:
3435 * @pad: a #GstPad to push the event to.
3436 * @event: the #GstEvent to send to the pad.
3438 * Sends the event to the peer of the given pad. This function is
3439 * mainly used by elements to send events to their peer
3442 * Returns: TRUE if the event was handled.
3447 gst_pad_push_event (GstPad * pad, GstEvent * event)
3452 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
3453 g_return_val_if_fail (event != NULL, FALSE);
3454 g_return_val_if_fail (GST_IS_EVENT (event), FALSE);
3457 if (G_UNLIKELY (GST_PAD_DO_EVENT_SIGNALS (pad) > 0)) {
3460 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (event)))
3465 peerpad = GST_PAD_PEER (pad);
3466 if (peerpad == NULL)
3469 GST_LOG_OBJECT (peerpad, "sending event on peerpad");
3470 gst_object_ref (peerpad);
3473 result = gst_pad_send_event (peerpad, event);
3475 gst_object_unref (peerpad);
3476 GST_LOG_OBJECT (peerpad, "sent event on peerpad");
3480 /* ERROR handling */
3483 GST_DEBUG_OBJECT (pad, "Dropping event after FALSE probe return");
3484 gst_event_unref (event);
3489 gst_event_unref (event);
3496 * gst_pad_send_event:
3497 * @pad: a #GstPad to send the event to.
3498 * @event: the #GstEvent to send to the pad.
3500 * Sends the event to the pad. This function can be used
3501 * by applications to send events in the pipeline.
3503 * Returns: TRUE if the event was handled.
3506 gst_pad_send_event (GstPad * pad, GstEvent * event)
3508 gboolean result = FALSE;
3509 GstPadEventFunction eventfunc;
3510 gboolean emit_signal;
3512 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
3513 g_return_val_if_fail (event != NULL, FALSE);
3516 if (GST_PAD_IS_SINK (pad) && !GST_EVENT_IS_DOWNSTREAM (event))
3517 goto wrong_direction;
3518 if (GST_PAD_IS_SRC (pad) && !GST_EVENT_IS_UPSTREAM (event))
3519 goto wrong_direction;
3521 if (GST_EVENT_SRC (event) == NULL) {
3522 GST_LOG_OBJECT (pad, "event had no source, setting pad as event source");
3523 GST_EVENT_SRC (event) = gst_object_ref (pad);
3526 switch (GST_EVENT_TYPE (event)) {
3527 case GST_EVENT_FLUSH_START:
3528 GST_CAT_DEBUG (GST_CAT_EVENT,
3529 "have event type %d (FLUSH_START) on pad %s:%s",
3530 GST_EVENT_TYPE (event), GST_DEBUG_PAD_NAME (pad));
3532 /* can't even accept a flush begin event when flushing */
3533 if (GST_PAD_IS_FLUSHING (pad))
3535 GST_PAD_SET_FLUSHING (pad);
3536 GST_CAT_DEBUG (GST_CAT_EVENT, "set flush flag");
3538 case GST_EVENT_FLUSH_STOP:
3539 GST_PAD_UNSET_FLUSHING (pad);
3540 GST_CAT_DEBUG (GST_CAT_EVENT, "cleared flush flag");
3543 GST_CAT_DEBUG (GST_CAT_EVENT, "have event type %s on pad %s:%s",
3544 gst_event_type_get_name (GST_EVENT_TYPE (event)),
3545 GST_DEBUG_PAD_NAME (pad));
3547 if (GST_PAD_IS_FLUSHING (pad))
3552 if ((eventfunc = GST_PAD_EVENTFUNC (pad)) == NULL)
3555 emit_signal = GST_PAD_DO_EVENT_SIGNALS (pad) > 0;
3558 if (G_UNLIKELY (emit_signal)) {
3559 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (event)))
3563 result = eventfunc (GST_PAD_CAST (pad), event);
3567 /* ERROR handling */
3570 g_warning ("pad %s:%s sending event in wrong direction",
3571 GST_DEBUG_PAD_NAME (pad));
3573 gst_event_unref (event);
3578 g_warning ("pad %s:%s has no event handler, file a bug.",
3579 GST_DEBUG_PAD_NAME (pad));
3581 gst_event_unref (event);
3587 GST_CAT_INFO (GST_CAT_EVENT, "Received event on flushing pad. Discarding");
3588 gst_event_unref (event);
3593 GST_DEBUG ("Dropping event after FALSE probe return");
3594 gst_event_unref (event);
3600 * gst_pad_set_element_private:
3601 * @pad: the #GstPad to set the private data of.
3602 * @priv: The private data to attach to the pad.
3604 * Set the given private data gpointer on the pad.
3605 * This function can only be used by the element that owns the pad.
3608 gst_pad_set_element_private (GstPad * pad, gpointer priv)
3610 pad->element_private = priv;
3614 * gst_pad_get_element_private:
3615 * @pad: the #GstPad to get the private data of.
3617 * Gets the private data of a pad.
3619 * Returns: a #gpointer to the private data.
3622 gst_pad_get_element_private (GstPad * pad)
3624 return pad->element_private;
3628 * gst_pad_start_task:
3629 * @pad: the #GstPad to start the task of
3630 * @func: the task function to call
3631 * @data: data passed to the task function
3633 * Starts a task that repeadedly calls @func with @data. This function
3634 * is nostly used in the pad activation function to start the
3635 * dataflow. This function will automatically acauire the STREAM_LOCK of
3636 * the pad before calling @func.
3638 * Returns: a TRUE if the task could be started.
3641 gst_pad_start_task (GstPad * pad, GstTaskFunction func, gpointer data)
3645 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
3646 g_return_val_if_fail (func != NULL, FALSE);
3649 task = GST_PAD_TASK (pad);
3651 task = gst_task_create (func, data);
3652 gst_task_set_lock (task, GST_STREAM_GET_LOCK (pad));
3653 GST_PAD_TASK (pad) = task;
3655 gst_task_start (task);
3662 * gst_pad_pause_task:
3663 * @pad: the #GstPad to pause the task of
3665 * Pause the task of @pad. This function will also make sure that the
3666 * function executed by the task will effectively stop.
3668 * Returns: a TRUE if the task could be paused or FALSE when the pad
3672 gst_pad_pause_task (GstPad * pad)
3676 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
3679 task = GST_PAD_TASK (pad);
3682 gst_task_pause (task);
3685 GST_STREAM_LOCK (pad);
3686 GST_STREAM_UNLOCK (pad);
3692 GST_WARNING_OBJECT (pad,
3693 "pad has no task -- very likely a programming error");
3700 * gst_pad_stop_task:
3701 * @pad: the #GstPad to stop the task of
3703 * Stop the task of @pad. This function will also make sure that the
3704 * function executed by the task will effectively stop if not called
3705 * from the GstTaskFunction.
3707 * This function will deadlock if called from the GstTaskFunction of
3708 * the task. Use #gst_task_pause() instead.
3710 * Regardless of whether the pad has a task, the stream lock is acquired and
3711 * released so as to ensure that streaming through this pad has finished.
3713 * Returns: a TRUE if the task could be stopped or FALSE on error.
3716 gst_pad_stop_task (GstPad * pad)
3720 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
3723 task = GST_PAD_TASK (pad);
3726 GST_PAD_TASK (pad) = NULL;
3727 gst_task_stop (task);
3730 GST_STREAM_LOCK (pad);
3731 GST_STREAM_UNLOCK (pad);
3733 gst_task_join (task);
3735 gst_object_unref (task);
3743 GST_STREAM_LOCK (pad);
3744 GST_STREAM_UNLOCK (pad);