1 /* GStreamer
2 * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
3 * 2000 Wim Taymans <wtay@chello.be>
4 *
5 * gstpad.c: Pads for linking elements together
6 *
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.
11 *
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.
16 *
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.
21 */
22 /**
23 * SECTION:gstpad
24 * @short_description: Object contained by elements that allows links to other elements
25 * @see_also: #GstPadTemplate, #GstElement, #GstEvent
26 *
27 * A #GstElement is linked to other elements via "pads", which are extremely
28 * light-weight generic link points.
29 * After two pads are retrieved from an element with gst_element_get_pad(),
30 * the pads can be link with gst_pad_link(). (For quick links,
31 * you can also use gst_element_link(), which will make the obvious
32 * link for you if it's straightforward.)
33 *
34 * Pads are typically created from a #GstPadTemplate with
35 * gst_pad_new_from_template().
36 *
37 * Pads have #GstCaps attached to it to describe the media type they are capable
38 * of dealing with.
39 * gst_pad_get_caps() and gst_pad_try_set_caps() are used to manipulate the caps
40 * of the pads.
41 * Pads created from a pad template cannot set capabilities that are
42 * incompatible with the pad template capabilities.
43 *
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.
47 *
48 * gst_pad_get_parent() will retrieve the #GstElement that owns the pad.
49 *
50 * A #GstElement creating a pad will typically use the various
51 * gst_pad_set_*_function() calls to register callbacks for various events
52 * on the pads.
53 *
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.
58 *
59 * To send a #GstEvent on a pad, use gst_pad_send_event().
60 *
61 * Last reviewed on December 13th, 2002 (0.5.0.1)
62 */
64 #include "gst_private.h"
66 #include "gstpad.h"
67 #include "gstpadtemplate.h"
68 #include "gstenumtypes.h"
69 #include "gstmarshal.h"
70 #include "gstutils.h"
71 #include "gstinfo.h"
72 #include "gsterror.h"
73 #include "gstvalue.h"
75 GST_DEBUG_CATEGORY_STATIC (debug_dataflow);
76 #define DEBUG_DATA(obj,data,notice) G_STMT_START{\
77 if (!data) { \
78 GST_CAT_DEBUG_OBJECT (debug_dataflow, obj, "NULL data value"); \
79 } else if (GST_IS_EVENT (data)) { \
80 GST_CAT_DEBUG_OBJECT (debug_dataflow, obj, "%s event %p (type %d, refcount %d)", notice, data, \
81 GST_EVENT_TYPE (data), GST_DATA_REFCOUNT_VALUE (data)); \
82 } else { \
83 GST_CAT_LOG_OBJECT (debug_dataflow, obj, "%s buffer %p (size %u, refcount %d)", notice, data, \
84 GST_BUFFER_SIZE (data), GST_BUFFER_REFCOUNT_VALUE (data)); \
85 } \
86 }G_STMT_END
87 #define GST_CAT_DEFAULT GST_CAT_PADS
89 /* Pad signals and args */
90 enum
91 {
92 PAD_LINKED,
93 PAD_UNLINKED,
94 PAD_REQUEST_LINK,
95 PAD_HAVE_DATA,
96 /* FILL ME */
97 LAST_SIGNAL
98 };
100 enum
101 {
102 PAD_PROP_0,
103 PAD_PROP_CAPS,
104 PAD_PROP_DIRECTION,
105 PAD_PROP_TEMPLATE,
106 /* FILL ME */
107 };
109 GType _gst_pad_type = 0;
111 static void gst_pad_class_init (GstPadClass * klass);
112 static void gst_pad_init (GstPad * pad);
113 static void gst_pad_dispose (GObject * object);
114 static void gst_pad_finalize (GObject * object);
115 static void gst_pad_set_property (GObject * object, guint prop_id,
116 const GValue * value, GParamSpec * pspec);
117 static void gst_pad_get_property (GObject * object, guint prop_id,
118 GValue * value, GParamSpec * pspec);
120 static void handle_pad_block (GstPad * pad);
121 static GstCaps *gst_pad_get_caps_unlocked (GstPad * pad);
122 static void gst_pad_set_pad_template (GstPad * pad, GstPadTemplate * templ);
123 static gboolean gst_pad_activate_default (GstPad * pad);
125 #ifndef GST_DISABLE_LOADSAVE
126 static xmlNodePtr gst_pad_save_thyself (GstObject * object, xmlNodePtr parent);
127 #endif
129 static GstObjectClass *parent_class = NULL;
130 static guint gst_pad_signals[LAST_SIGNAL] = { 0 };
132 static GQuark buffer_quark;
133 static GQuark event_quark;
135 GType
136 gst_pad_get_type (void)
137 {
138 if (!_gst_pad_type) {
139 static const GTypeInfo pad_info = {
140 sizeof (GstPadClass), NULL, NULL,
141 (GClassInitFunc) gst_pad_class_init, NULL, NULL,
142 sizeof (GstPad),
143 0,
144 (GInstanceInitFunc) gst_pad_init, NULL
145 };
147 _gst_pad_type = g_type_register_static (GST_TYPE_OBJECT, "GstPad",
148 &pad_info, 0);
150 buffer_quark = g_quark_from_static_string ("buffer");
151 event_quark = g_quark_from_static_string ("event");
153 GST_DEBUG_CATEGORY_INIT (debug_dataflow, "GST_DATAFLOW",
154 GST_DEBUG_BOLD | GST_DEBUG_FG_GREEN, "dataflow inside pads");
155 }
156 return _gst_pad_type;
157 }
159 static gboolean
160 _gst_do_pass_data_accumulator (GSignalInvocationHint * ihint,
161 GValue * return_accu, const GValue * handler_return, gpointer dummy)
162 {
163 gboolean ret = g_value_get_boolean (handler_return);
165 GST_DEBUG ("accumulated %d", ret);
166 g_value_set_boolean (return_accu, ret);
168 return ret;
169 }
171 static gboolean
172 default_have_data (GstPad * pad, GstMiniObject * o)
173 {
174 return TRUE;
175 }
177 static void
178 gst_pad_class_init (GstPadClass * klass)
179 {
180 GObjectClass *gobject_class;
183 GstObjectClass *gstobject_class;
185 gobject_class = (GObjectClass *) klass;
186 gstobject_class = (GstObjectClass *) klass;
188 parent_class = g_type_class_ref (GST_TYPE_OBJECT);
190 gobject_class->dispose = GST_DEBUG_FUNCPTR (gst_pad_dispose);
191 gobject_class->finalize = GST_DEBUG_FUNCPTR (gst_pad_finalize);
192 gobject_class->set_property = GST_DEBUG_FUNCPTR (gst_pad_set_property);
193 gobject_class->get_property = GST_DEBUG_FUNCPTR (gst_pad_get_property);
195 /**
196 * GstPad::linked:
197 * @pad: the pad that emitted the signal
198 * @peer: the peer pad that has been connected
199 *
200 * Signals that a pad has been linked to the peer pad.
201 */
202 gst_pad_signals[PAD_LINKED] =
203 g_signal_new ("linked", G_TYPE_FROM_CLASS (klass), G_SIGNAL_RUN_LAST,
204 G_STRUCT_OFFSET (GstPadClass, linked), NULL, NULL,
205 gst_marshal_VOID__OBJECT, G_TYPE_NONE, 1, GST_TYPE_PAD);
206 /**
207 * GstPad::unlinked:
208 * @pad: the pad that emitted the signal
209 * @peer: the peer pad that has been disconnected
210 *
211 * Signals that a pad has been unlinked from the peer pad.
212 */
213 gst_pad_signals[PAD_UNLINKED] =
214 g_signal_new ("unlinked", G_TYPE_FROM_CLASS (klass), G_SIGNAL_RUN_LAST,
215 G_STRUCT_OFFSET (GstPadClass, unlinked), NULL, NULL,
216 gst_marshal_VOID__OBJECT, G_TYPE_NONE, 1, GST_TYPE_PAD);
217 /**
218 * GstPad::request-link:
219 * @pad: the pad that emitted the signal
220 * @peer: the peer pad for which a connection is requested
221 *
222 * Signals that a pad connection has been requested.
223 */
224 gst_pad_signals[PAD_REQUEST_LINK] =
225 g_signal_new ("request-link", G_TYPE_FROM_CLASS (klass),
226 G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GstPadClass, request_link), NULL,
227 NULL, gst_marshal_VOID__OBJECT, G_TYPE_NONE, 0);
229 /**
230 * GstPad::have-data:
231 * @pad: the pad that emitted the signal
232 * @mini_obj: new data
233 *
234 * Signals that new data is available on the pad. This signal is used
235 * internally for implementing pad probes.
236 * See gst_pad_add_*_probe functions.
237 *
238 * Returns: %TRUE to keep the data, %FALSE to drop it
239 */
240 gst_pad_signals[PAD_HAVE_DATA] =
241 g_signal_new ("have-data", G_TYPE_FROM_CLASS (klass),
242 G_SIGNAL_RUN_LAST | G_SIGNAL_DETAILED,
243 G_STRUCT_OFFSET (GstPadClass, have_data),
244 _gst_do_pass_data_accumulator,
245 NULL, gst_marshal_BOOLEAN__POINTER, G_TYPE_BOOLEAN, 1,
246 GST_TYPE_MINI_OBJECT);
248 g_object_class_install_property (G_OBJECT_CLASS (klass), PAD_PROP_CAPS,
249 g_param_spec_boxed ("caps", "Caps", "The capabilities of the pad",
250 GST_TYPE_CAPS, G_PARAM_READABLE));
251 g_object_class_install_property (G_OBJECT_CLASS (klass), PAD_PROP_DIRECTION,
252 g_param_spec_enum ("direction", "Direction", "The direction of the pad",
253 GST_TYPE_PAD_DIRECTION, GST_PAD_UNKNOWN,
254 G_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY));
255 g_object_class_install_property (G_OBJECT_CLASS (klass), PAD_PROP_TEMPLATE,
256 g_param_spec_object ("template", "Template",
257 "The GstPadTemplate of this pad", GST_TYPE_PAD_TEMPLATE,
258 G_PARAM_READWRITE));
260 #ifndef GST_DISABLE_LOADSAVE
261 gstobject_class->save_thyself = GST_DEBUG_FUNCPTR (gst_pad_save_thyself);
262 #endif
263 gstobject_class->path_string_separator = ".";
265 klass->have_data = default_have_data;
266 }
268 static void
269 gst_pad_init (GstPad * pad)
270 {
271 pad->direction = GST_PAD_UNKNOWN;
272 pad->peer = NULL;
274 pad->chainfunc = NULL;
276 pad->caps = NULL;
278 pad->linkfunc = NULL;
279 pad->getcapsfunc = NULL;
281 pad->activatefunc = gst_pad_activate_default;
282 pad->eventfunc = gst_pad_event_default;
283 pad->querytypefunc = gst_pad_get_query_types_default;
284 pad->queryfunc = gst_pad_query_default;
285 pad->intlinkfunc = gst_pad_get_internal_links_default;
287 pad->do_buffer_signals = 0;
288 pad->do_event_signals = 0;
290 GST_PAD_UNSET_FLUSHING (pad);
292 pad->preroll_lock = g_mutex_new ();
293 pad->preroll_cond = g_cond_new ();
295 pad->stream_rec_lock = g_new (GStaticRecMutex, 1);
296 g_static_rec_mutex_init (pad->stream_rec_lock);
298 pad->block_cond = g_cond_new ();
299 }
301 static void
302 gst_pad_dispose (GObject * object)
303 {
304 GstPad *pad = GST_PAD (object);
306 GST_CAT_DEBUG (GST_CAT_REFCOUNTING, "dispose %s:%s",
307 GST_DEBUG_PAD_NAME (pad));
309 /* we don't hold a ref to the peer so we can just set the
310 * peer to NULL. */
311 GST_PAD_PEER (pad) = NULL;
313 /* clear the caps */
314 gst_caps_replace (&GST_PAD_CAPS (pad), NULL);
316 gst_pad_set_pad_template (pad, NULL);
318 G_OBJECT_CLASS (parent_class)->dispose (object);
319 }
321 static void
322 gst_pad_finalize (GObject * object)
323 {
324 GstPad *pad = GST_PAD (object);
325 GstTask *task;
327 /* in case the task is still around, clean it up */
328 if ((task = GST_PAD_TASK (pad))) {
329 gst_task_join (task);
330 GST_PAD_TASK (pad) = NULL;
331 gst_object_unref (task);
332 }
334 if (pad->stream_rec_lock) {
335 g_static_rec_mutex_free (pad->stream_rec_lock);
336 g_free (pad->stream_rec_lock);
337 pad->stream_rec_lock = NULL;
338 }
339 if (pad->preroll_lock) {
340 g_mutex_free (pad->preroll_lock);
341 g_cond_free (pad->preroll_cond);
342 pad->preroll_lock = NULL;
343 pad->preroll_cond = NULL;
344 }
345 if (pad->block_cond) {
346 g_cond_free (pad->block_cond);
347 pad->block_cond = NULL;
348 }
350 G_OBJECT_CLASS (parent_class)->finalize (object);
351 }
353 static void
354 gst_pad_set_property (GObject * object, guint prop_id,
355 const GValue * value, GParamSpec * pspec)
356 {
357 g_return_if_fail (GST_IS_PAD (object));
359 switch (prop_id) {
360 case PAD_PROP_DIRECTION:
361 GST_PAD_DIRECTION (object) = g_value_get_enum (value);
362 break;
363 case PAD_PROP_TEMPLATE:
364 gst_pad_set_pad_template (GST_PAD_CAST (object),
365 (GstPadTemplate *) g_value_dup_object (value));
366 break;
367 default:
368 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
369 break;
370 }
371 }
373 static void
374 gst_pad_get_property (GObject * object, guint prop_id,
375 GValue * value, GParamSpec * pspec)
376 {
377 g_return_if_fail (GST_IS_PAD (object));
379 switch (prop_id) {
380 case PAD_PROP_CAPS:
381 g_value_set_boxed (value, GST_PAD_CAPS (object));
382 break;
383 case PAD_PROP_DIRECTION:
384 g_value_set_enum (value, GST_PAD_DIRECTION (object));
385 break;
386 case PAD_PROP_TEMPLATE:
387 g_value_set_object (value, GST_PAD_TEMPLATE (object));
388 break;
389 default:
390 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
391 break;
392 }
393 }
395 /**
396 * gst_pad_new:
397 * @name: the name of the new pad.
398 * @direction: the #GstPadDirection of the pad.
399 *
400 * Creates a new pad with the given name in the given direction.
401 * If name is NULL, a guaranteed unique name (across all pads)
402 * will be assigned.
403 * This function makes a copy of the name so you can safely free the name.
404 *
405 * Returns: a new #GstPad, or NULL in case of an error.
406 *
407 * MT safe.
408 */
409 GstPad *
410 gst_pad_new (const gchar * name, GstPadDirection direction)
411 {
412 return g_object_new (GST_TYPE_PAD,
413 "name", name, "direction", direction, NULL);
414 }
416 /**
417 * gst_pad_new_from_template:
418 * @templ: the pad template to use
419 * @name: the name of the element
420 *
421 * Creates a new pad with the given name from the given template.
422 * If name is NULL, a guaranteed unique name (across all pads)
423 * will be assigned.
424 * This function makes a copy of the name so you can safely free the name.
425 *
426 * Returns: a new #GstPad, or NULL in case of an error.
427 */
428 GstPad *
429 gst_pad_new_from_template (GstPadTemplate * templ, const gchar * name)
430 {
431 g_return_val_if_fail (GST_IS_PAD_TEMPLATE (templ), NULL);
433 return g_object_new (GST_TYPE_PAD,
434 "name", name, "direction", templ->direction, "template", templ, NULL);
435 }
437 /**
438 * gst_pad_get_direction:
439 * @pad: a #GstPad to get the direction of.
440 *
441 * Gets the direction of the pad. The direction of the pad is
442 * decided at construction time so this function does not take
443 * the LOCK.
444 *
445 * Returns: the #GstPadDirection of the pad.
446 *
447 * MT safe.
448 */
449 GstPadDirection
450 gst_pad_get_direction (GstPad * pad)
451 {
452 GstPadDirection result;
454 /* PAD_UNKNOWN is a little silly but we need some sort of
455 * error return value */
456 g_return_val_if_fail (GST_IS_PAD (pad), GST_PAD_UNKNOWN);
458 GST_LOCK (pad);
459 result = GST_PAD_DIRECTION (pad);
460 GST_UNLOCK (pad);
462 return result;
463 }
465 static gboolean
466 gst_pad_activate_default (GstPad * pad)
467 {
468 return gst_pad_activate_push (pad, TRUE);
469 }
471 static void
472 pre_activate_switch (GstPad * pad, gboolean new_active)
473 {
474 if (new_active) {
475 return;
476 } else {
477 GST_LOCK (pad);
478 GST_PAD_SET_FLUSHING (pad);
479 /* unlock blocked pads so element can resume and stop */
480 GST_PAD_BLOCK_SIGNAL (pad);
481 GST_UNLOCK (pad);
482 }
483 }
485 static void
486 post_activate_switch (GstPad * pad, gboolean new_active)
487 {
488 if (new_active) {
489 GST_LOCK (pad);
490 GST_PAD_UNSET_FLUSHING (pad);
491 GST_UNLOCK (pad);
492 } else {
493 /* make streaming stop */
494 GST_STREAM_LOCK (pad);
495 GST_STREAM_UNLOCK (pad);
496 }
497 }
499 /**
500 * gst_pad_set_active:
501 * @pad: the #GstPad to activate or deactivate.
502 * @active: whether or not the pad should be active.
503 *
504 * Activates or deactivates the given pad. Must be called with the %GST_STATE_LOCK.
505 * Normally called from within core state change functions.
506 *
507 * If @active, makes sure the pad is active. If it is already active, either in
508 * push or pull mode, just return. Otherwise dispatches to the pad's activate
509 * function to perform the actual activation.
510 *
511 * If not @active, checks the pad's current mode and calls
512 * gst_pad_activate_push() or gst_pad_activate_pull(), as appropriate, with a
513 * FALSE argument.
514 *
515 * Returns: TRUE if the operation was successfull.
516 *
517 * MT safe. Must be called with %GST_STATE_LOCK.
518 */
519 gboolean
520 gst_pad_set_active (GstPad * pad, gboolean active)
521 {
522 GstActivateMode old;
523 gboolean ret = FALSE;
525 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
527 GST_LOCK (pad);
528 old = GST_PAD_ACTIVATE_MODE (pad);
529 GST_UNLOCK (pad);
531 if (active) {
532 switch (old) {
533 case GST_ACTIVATE_PUSH:
534 case GST_ACTIVATE_PULL:
535 ret = TRUE;
536 break;
537 case GST_ACTIVATE_NONE:
538 ret = (GST_PAD_ACTIVATEFUNC (pad)) (pad);
539 break;
540 }
541 } else {
542 switch (old) {
543 case GST_ACTIVATE_PUSH:
544 ret = gst_pad_activate_push (pad, FALSE);
545 break;
546 case GST_ACTIVATE_PULL:
547 ret = gst_pad_activate_pull (pad, FALSE);
548 break;
549 case GST_ACTIVATE_NONE:
550 ret = TRUE;
551 break;
552 }
553 }
555 return ret;
556 }
558 /**
559 * gst_pad_activate_pull:
560 * @pad: the #GstPad to activate or deactivate.
561 * @active: whether or not the pad should be active.
562 *
563 * Activates or deactivates the given pad in pull mode via dispatching to the
564 * pad's activatepullfunc. For use from within pad activation functions only.
565 * When called on sink pads, will first proxy the call to the peer pad, which is
566 * expected to activate its internally linked pads from within its activate_pull
567 * function.
568 *
569 * If you don't know what this is, you probably don't want to call it.
570 *
571 * Returns: TRUE if the operation was successfull.
572 *
573 * MT safe.
574 */
575 gboolean
576 gst_pad_activate_pull (GstPad * pad, gboolean active)
577 {
578 GstActivateMode old;
580 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
582 GST_LOCK (pad);
583 old = GST_PAD_ACTIVATE_MODE (pad);
584 GST_UNLOCK (pad);
586 if ((active && old == GST_ACTIVATE_PULL)
587 || (!active && old == GST_ACTIVATE_NONE))
588 goto was_ok;
590 if (active) {
591 g_return_val_if_fail (old == GST_ACTIVATE_NONE, FALSE);
592 } else {
593 g_return_val_if_fail (old == GST_ACTIVATE_PULL, FALSE);
594 }
596 if (gst_pad_get_direction (pad) == GST_PAD_SINK) {
597 GstPad *peer = gst_pad_get_peer (pad);
599 if (peer) {
600 if (!gst_pad_activate_pull (peer, active)) {
601 GST_LOCK (peer);
602 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
603 "activate_pull on peer (%s:%s) failed", GST_DEBUG_PAD_NAME (peer));
604 GST_UNLOCK (peer);
605 gst_object_unref (peer);
606 goto failure;
607 }
608 }
609 }
611 pre_activate_switch (pad, active);
613 if (GST_PAD_ACTIVATEPULLFUNC (pad)) {
614 if (GST_PAD_ACTIVATEPULLFUNC (pad) (pad, active)) {
615 goto success;
616 } else {
617 goto failure;
618 }
619 } else {
620 /* can happen for sinks of passthrough elements */
621 goto success;
622 }
624 was_ok:
625 {
626 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "already %s in pull mode",
627 active ? "activated" : "deactivated");
628 return TRUE;
629 }
631 success:
632 {
633 GST_LOCK (pad);
634 GST_PAD_ACTIVATE_MODE (pad) =
635 active ? GST_ACTIVATE_PULL : GST_ACTIVATE_NONE;
636 GST_UNLOCK (pad);
637 post_activate_switch (pad, active);
639 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "%s in pull mode",
640 active ? "activated" : "deactivated");
641 return TRUE;
642 }
644 failure:
645 {
646 GST_CAT_INFO_OBJECT (GST_CAT_PADS, pad, "failed to %s in pull mode",
647 active ? "activate" : "deactivate");
648 return FALSE;
649 }
650 }
652 /**
653 * gst_pad_activate_push:
654 * @pad: the #GstPad to activate or deactivate.
655 * @active: whether or not the pad should be active.
656 *
657 * Activates or deactivates the given pad in push mode via dispatching to the
658 * pad's activatepushfunc. For use from within pad activation functions only.
659 *
660 * If you don't know what this is, you probably don't want to call it.
661 *
662 * Returns: TRUE if the operation was successfull.
663 *
664 * MT safe.
665 */
666 gboolean
667 gst_pad_activate_push (GstPad * pad, gboolean active)
668 {
669 GstActivateMode old;
671 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
672 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "trying to set %s in push mode",
673 active ? "activated" : "deactivated");
675 GST_LOCK (pad);
676 old = GST_PAD_ACTIVATE_MODE (pad);
677 GST_UNLOCK (pad);
679 if ((active && old == GST_ACTIVATE_PUSH)
680 || (!active && old == GST_ACTIVATE_NONE))
681 goto was_ok;
683 if (active) {
684 g_return_val_if_fail (old == GST_ACTIVATE_NONE, FALSE);
685 } else {
686 g_return_val_if_fail (old == GST_ACTIVATE_PUSH, FALSE);
687 }
689 pre_activate_switch (pad, active);
691 if (GST_PAD_ACTIVATEPUSHFUNC (pad)) {
692 if (GST_PAD_ACTIVATEPUSHFUNC (pad) (pad, active)) {
693 goto success;
694 } else {
695 goto failure;
696 }
697 } else {
698 /* quite ok, element relies on state change func to prepare itself */
699 goto success;
700 }
702 was_ok:
703 {
704 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "already %s in push mode",
705 active ? "activated" : "deactivated");
706 return TRUE;
707 }
709 success:
710 {
711 GST_LOCK (pad);
712 GST_PAD_ACTIVATE_MODE (pad) =
713 active ? GST_ACTIVATE_PUSH : GST_ACTIVATE_NONE;
714 GST_UNLOCK (pad);
715 post_activate_switch (pad, active);
717 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "%s in push mode",
718 active ? "activated" : "deactivated");
719 return TRUE;
720 }
722 failure:
723 {
724 GST_CAT_INFO_OBJECT (GST_CAT_PADS, pad, "failed to %s in push mode",
725 active ? "activate" : "deactivate");
726 return FALSE;
727 }
728 }
730 /**
731 * gst_pad_is_active:
732 * @pad: the #GstPad to query
733 *
734 * Query if a pad is active
735 *
736 * Returns: TRUE if the pad is active.
737 *
738 * MT safe.
739 */
740 gboolean
741 gst_pad_is_active (GstPad * pad)
742 {
743 gboolean result = FALSE;
745 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
747 GST_LOCK (pad);
748 result = GST_PAD_MODE_ACTIVATE (GST_PAD_ACTIVATE_MODE (pad));
749 GST_UNLOCK (pad);
751 return result;
752 }
754 /**
755 * gst_pad_set_blocked_async:
756 * @pad: the #GstPad to block or unblock
757 * @blocked: boolean indicating we should block or unblock
758 * @callback: #GstPadBlockCallback that will be called when the
759 * operation succeeds.
760 * @user_data: user data passed to the callback
761 *
762 * Blocks or unblocks the dataflow on a pad. The provided callback
763 * is called when the operation succeeds. This can take a while as
764 * the pad can only become blocked when real dataflow is happening.
765 * When the pipeline is stalled, for example in PAUSED, this can
766 * take an indeterminate amount of time.
767 * You can pass NULL as the callback to make this call block. Be
768 * carefull with this blocking call as it might not return for
769 * reasons stated above.
770 *
771 * Returns: TRUE if the pad could be blocked. This function can fail
772 * if wrong parameters were passed or the pad was already in the
773 * requested state.
774 *
775 * MT safe.
776 */
777 gboolean
778 gst_pad_set_blocked_async (GstPad * pad, gboolean blocked,
779 GstPadBlockCallback callback, gpointer user_data)
780 {
781 gboolean was_blocked;
783 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
785 GST_LOCK (pad);
787 was_blocked = GST_PAD_IS_BLOCKED (pad);
789 if (G_UNLIKELY (was_blocked == blocked))
790 goto had_right_state;
792 if (blocked) {
793 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "blocking pad %s:%s",
794 GST_DEBUG_PAD_NAME (pad));
796 GST_FLAG_SET (pad, GST_PAD_BLOCKED);
797 pad->block_callback = callback;
798 pad->block_data = user_data;
799 if (!callback) {
800 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "waiting for block");
801 GST_PAD_BLOCK_WAIT (pad);
802 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "blocked");
803 }
804 } else {
805 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "unblocking pad %s:%s",
806 GST_DEBUG_PAD_NAME (pad));
808 GST_FLAG_UNSET (pad, GST_PAD_BLOCKED);
810 pad->block_callback = callback;
811 pad->block_data = user_data;
813 if (callback) {
814 GST_PAD_BLOCK_SIGNAL (pad);
815 } else {
816 GST_PAD_BLOCK_SIGNAL (pad);
817 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "waiting for unblock");
818 GST_PAD_BLOCK_WAIT (pad);
819 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "unblocked");
820 }
821 }
822 GST_UNLOCK (pad);
824 return TRUE;
826 had_right_state:
827 {
828 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
829 "pad %s:%s was in right state", GST_DEBUG_PAD_NAME (pad));
830 GST_UNLOCK (pad);
831 return FALSE;
832 }
833 }
835 /**
836 * gst_pad_set_blocked:
837 * @pad: the #GstPad to block or unblock
838 * @blocked: boolean indicating we should block or unblock
839 *
840 * Blocks or unblocks the dataflow on a pad. This function is
841 * a shortcut for @gst_pad_set_blocked_async() with a NULL
842 * callback.
843 *
844 * Returns: TRUE if the pad could be blocked. This function can fail
845 * wrong parameters were passed or the pad was already in the
846 * requested state.
847 *
848 * MT safe.
849 */
850 gboolean
851 gst_pad_set_blocked (GstPad * pad, gboolean blocked)
852 {
853 return gst_pad_set_blocked_async (pad, blocked, NULL, NULL);
854 }
856 /**
857 * gst_pad_is_blocked:
858 * @pad: the #GstPad to query
859 *
860 * Checks if the pad is blocked or not. This function returns the
861 * last requested state of the pad. It is not certain that the pad
862 * is actually blocked at this point.
863 *
864 * Returns: TRUE if the pad is blocked.
865 *
866 * MT safe.
867 */
868 gboolean
869 gst_pad_is_blocked (GstPad * pad)
870 {
871 gboolean result = FALSE;
873 g_return_val_if_fail (GST_IS_PAD (pad), result);
875 GST_LOCK (pad);
876 result = GST_FLAG_IS_SET (pad, GST_PAD_BLOCKED);
877 GST_UNLOCK (pad);
879 return result;
880 }
882 /**
883 * gst_pad_set_activate_function:
884 * @pad: a sink #GstPad.
885 * @activate: the #GstPadActivateFunction to set.
886 *
887 * Sets the given activate function for the pad. The activate function will
888 * dispatch to activate_push or activate_pull to perform the actual activation.
889 * Only makes sense to set on sink pads.
890 *
891 * Call this function if your sink pad can start a pull-based task.
892 */
893 void
894 gst_pad_set_activate_function (GstPad * pad, GstPadActivateFunction activate)
895 {
896 g_return_if_fail (GST_IS_PAD (pad));
898 GST_PAD_ACTIVATEFUNC (pad) = activate;
899 GST_CAT_DEBUG (GST_CAT_PADS, "activatefunc for %s:%s set to %s",
900 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (activate));
901 }
903 /**
904 * gst_pad_set_activatepull_function:
905 * @pad: a sink #GstPad.
906 * @activatepull: the #GstPadActivateModeFunction to set.
907 *
908 * Sets the given activate_pull function for the pad. An activate_pull function
909 * prepares the element and any upstream connections for pulling. See XXX
910 * part-activation.txt for details.
911 */
912 void
913 gst_pad_set_activatepull_function (GstPad * pad,
914 GstPadActivateModeFunction activatepull)
915 {
916 g_return_if_fail (GST_IS_PAD (pad));
918 GST_PAD_ACTIVATEPULLFUNC (pad) = activatepull;
919 GST_CAT_DEBUG (GST_CAT_PADS, "activatepullfunc for %s:%s set to %s",
920 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (activatepull));
921 }
923 /**
924 * gst_pad_set_activatepush_function:
925 * @pad: a sink #GstPad.
926 * @activatepush: the #GstPadActivateModeFunction to set.
927 *
928 * Sets the given activate_push function for the pad. An activate_push function
929 * prepares the element for pushing. See XXX part-activation.txt for details.
930 */
931 void
932 gst_pad_set_activatepush_function (GstPad * pad,
933 GstPadActivateModeFunction activatepush)
934 {
935 g_return_if_fail (GST_IS_PAD (pad));
937 GST_PAD_ACTIVATEPUSHFUNC (pad) = activatepush;
938 GST_CAT_DEBUG (GST_CAT_PADS, "activatepushfunc for %s:%s set to %s",
939 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (activatepush));
940 }
942 /**
943 * gst_pad_set_chain_function:
944 * @pad: a sink #GstPad.
945 * @chain: the #GstPadChainFunction to set.
946 *
947 * Sets the given chain function for the pad. The chain function is called to
948 * process a #GstBuffer input buffer.
949 */
950 void
951 gst_pad_set_chain_function (GstPad * pad, GstPadChainFunction chain)
952 {
953 g_return_if_fail (GST_IS_PAD (pad));
954 g_return_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SINK);
956 GST_PAD_CHAINFUNC (pad) = chain;
957 GST_CAT_DEBUG (GST_CAT_PADS, "chainfunc for %s:%s set to %s",
958 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (chain));
959 }
961 /**
962 * gst_pad_set_getrange_function:
963 * @pad: a source #GstPad.
964 * @get: the #GstPadGetRangeFunction to set.
965 *
966 * Sets the given getrange function for the pad. The getrange function is called to
967 * produce a new #GstBuffer to start the processing pipeline. Getrange functions cannot
968 * return %NULL.
969 */
970 void
971 gst_pad_set_getrange_function (GstPad * pad, GstPadGetRangeFunction get)
972 {
973 g_return_if_fail (GST_IS_PAD (pad));
974 g_return_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SRC);
976 GST_PAD_GETRANGEFUNC (pad) = get;
978 GST_CAT_DEBUG (GST_CAT_PADS, "getrangefunc for %s:%s set to %s",
979 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (get));
980 }
982 /**
983 * gst_pad_set_checkgetrange_function:
984 * @pad: a source #GstPad.
985 * @check: the #GstPadCheckGetRangeFunction to set.
986 *
987 * Sets the given checkgetrange function for the pad. Implement this function on
988 * a pad if you dynamically support getrange based scheduling on the pad.
989 */
990 void
991 gst_pad_set_checkgetrange_function (GstPad * pad,
992 GstPadCheckGetRangeFunction check)
993 {
994 g_return_if_fail (GST_IS_PAD (pad));
995 g_return_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SRC);
997 GST_PAD_CHECKGETRANGEFUNC (pad) = check;
999 GST_CAT_DEBUG (GST_CAT_PADS, "checkgetrangefunc for %s:%s set to %s",
1000 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (check));
1001 }
1003 /**
1004 * gst_pad_set_event_function:
1005 * @pad: a source #GstPad.
1006 * @event: the #GstPadEventFunction to set.
1007 *
1008 * Sets the given event handler for the pad.
1009 */
1010 void
1011 gst_pad_set_event_function (GstPad * pad, GstPadEventFunction event)
1012 {
1013 g_return_if_fail (GST_IS_PAD (pad));
1015 GST_PAD_EVENTFUNC (pad) = event;
1017 GST_CAT_DEBUG (GST_CAT_PADS, "eventfunc for %s:%s set to %s",
1018 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (event));
1019 }
1021 /**
1022 * gst_pad_set_query_function:
1023 * @pad: a #GstPad of either direction.
1024 * @query: the #GstPadQueryFunction to set.
1025 *
1026 * Set the given query function for the pad.
1027 */
1028 void
1029 gst_pad_set_query_function (GstPad * pad, GstPadQueryFunction query)
1030 {
1031 g_return_if_fail (GST_IS_PAD (pad));
1033 GST_PAD_QUERYFUNC (pad) = query;
1035 GST_CAT_DEBUG (GST_CAT_PADS, "queryfunc for %s:%s set to %s",
1036 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (query));
1037 }
1039 /**
1040 * gst_pad_set_query_type_function:
1041 * @pad: a #GstPad of either direction.
1042 * @type_func: the #GstPadQueryTypeFunction to set.
1043 *
1044 * Set the given query type function for the pad.
1045 */
1046 void
1047 gst_pad_set_query_type_function (GstPad * pad,
1048 GstPadQueryTypeFunction type_func)
1049 {
1050 g_return_if_fail (GST_IS_PAD (pad));
1052 GST_PAD_QUERYTYPEFUNC (pad) = type_func;
1054 GST_CAT_DEBUG (GST_CAT_PADS, "querytypefunc for %s:%s set to %s",
1055 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (type_func));
1056 }
1058 /**
1059 * gst_pad_get_query_types:
1060 * @pad: a #GstPad.
1061 *
1062 * Get an array of supported queries that can be performed
1063 * on this pad.
1064 *
1065 * Returns: a zero-terminated array of #GstQueryType.
1066 */
1067 const GstQueryType *
1068 gst_pad_get_query_types (GstPad * pad)
1069 {
1070 GstPadQueryTypeFunction func;
1072 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
1074 if (G_UNLIKELY ((func = GST_PAD_QUERYTYPEFUNC (pad)) == NULL))
1075 goto no_func;
1077 return func (pad);
1079 no_func:
1080 {
1081 return NULL;
1082 }
1083 }
1085 static gboolean
1086 gst_pad_get_query_types_dispatcher (GstPad * pad, const GstQueryType ** data)
1087 {
1088 *data = gst_pad_get_query_types (pad);
1090 return TRUE;
1091 }
1093 /**
1094 * gst_pad_get_query_types_default:
1095 * @pad: a #GstPad.
1096 *
1097 * Invoke the default dispatcher for the query types on
1098 * the pad.
1099 *
1100 * Returns: an zero-terminated array of #GstQueryType, or NULL if none of the
1101 * internally-linked pads has a query types function.
1102 */
1103 const GstQueryType *
1104 gst_pad_get_query_types_default (GstPad * pad)
1105 {
1106 GstQueryType *result = NULL;
1108 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
1110 gst_pad_dispatcher (pad, (GstPadDispatcherFunction)
1111 gst_pad_get_query_types_dispatcher, &result);
1113 return result;
1114 }
1116 /**
1117 * gst_pad_set_internal_link_function:
1118 * @pad: a #GstPad of either direction.
1119 * @intlink: the #GstPadIntLinkFunction to set.
1120 *
1121 * Sets the given internal link function for the pad.
1122 */
1123 void
1124 gst_pad_set_internal_link_function (GstPad * pad, GstPadIntLinkFunction intlink)
1125 {
1126 g_return_if_fail (GST_IS_PAD (pad));
1128 GST_PAD_INTLINKFUNC (pad) = intlink;
1129 GST_CAT_DEBUG (GST_CAT_PADS, "internal link for %s:%s set to %s",
1130 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (intlink));
1131 }
1133 /**
1134 * gst_pad_set_link_function:
1135 * @pad: a #GstPad.
1136 * @link: the #GstPadLinkFunction to set.
1137 *
1138 * Sets the given link function for the pad. It will be called when the pad is
1139 * linked or relinked with caps. The caps passed to the link function is
1140 * the caps for the connnection. It can contain a non fixed caps.
1141 *
1142 * The return value GST_PAD_LINK_OK should be used when the connection can be
1143 * made.
1144 *
1145 * The return value GST_PAD_LINK_REFUSED should be used when the connection
1146 * cannot be made for some reason.
1147 */
1148 void
1149 gst_pad_set_link_function (GstPad * pad, GstPadLinkFunction link)
1150 {
1151 g_return_if_fail (GST_IS_PAD (pad));
1153 GST_PAD_LINKFUNC (pad) = link;
1154 GST_CAT_DEBUG (GST_CAT_PADS, "linkfunc for %s:%s set to %s",
1155 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (link));
1156 }
1158 /**
1159 * gst_pad_set_unlink_function:
1160 * @pad: a #GstPad.
1161 * @unlink: the #GstPadUnlinkFunction to set.
1162 *
1163 * Sets the given unlink function for the pad. It will be called
1164 * when the pad is unlinked.
1165 */
1166 void
1167 gst_pad_set_unlink_function (GstPad * pad, GstPadUnlinkFunction unlink)
1168 {
1169 g_return_if_fail (GST_IS_PAD (pad));
1171 GST_PAD_UNLINKFUNC (pad) = unlink;
1172 GST_CAT_DEBUG (GST_CAT_PADS, "unlinkfunc for %s:%s set to %s",
1173 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (unlink));
1174 }
1176 /**
1177 * gst_pad_set_getcaps_function:
1178 * @pad: a #GstPad.
1179 * @getcaps: the #GstPadGetCapsFunction to set.
1180 *
1181 * Sets the given getcaps function for the pad. @getcaps should return the
1182 * allowable caps for a pad in the context of the element's state, its link to
1183 * other elements, and the devices or files it has opened. These caps must be a
1184 * subset of the pad template caps. In the NULL state with no links, @getcaps
1185 * should ideally return the same caps as the pad template. In rare
1186 * circumstances, an object property can affect the caps returned by @getcaps,
1187 * but this is discouraged.
1188 *
1189 * You do not need to call this function if @pad's allowed caps are always the
1190 * same as the pad template caps. This can only be true if the padtemplate
1191 * has fixed simple caps.
1192 *
1193 * For most filters, the caps returned by @getcaps is directly affected by the
1194 * allowed caps on other pads. For demuxers and decoders, the caps returned by
1195 * the srcpad's getcaps function is directly related to the stream data. Again,
1196 * @getcaps should return the most specific caps it reasonably can, since this
1197 * helps with autoplugging.
1198 *
1199 * Note that the return value from @getcaps is owned by the caller, so the caller
1200 * should unref the caps after usage.
1201 */
1202 void
1203 gst_pad_set_getcaps_function (GstPad * pad, GstPadGetCapsFunction getcaps)
1204 {
1205 g_return_if_fail (GST_IS_PAD (pad));
1207 GST_PAD_GETCAPSFUNC (pad) = getcaps;
1208 GST_CAT_DEBUG (GST_CAT_PADS, "getcapsfunc for %s:%s set to %s",
1209 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (getcaps));
1210 }
1212 /**
1213 * gst_pad_set_acceptcaps_function:
1214 * @pad: a #GstPad.
1215 * @acceptcaps: the #GstPadAcceptCapsFunction to set.
1216 *
1217 * Sets the given acceptcaps function for the pad. The acceptcaps function
1218 * will be called to check if the pad can accept the given caps.
1219 */
1220 void
1221 gst_pad_set_acceptcaps_function (GstPad * pad,
1222 GstPadAcceptCapsFunction acceptcaps)
1223 {
1224 g_return_if_fail (GST_IS_PAD (pad));
1226 GST_PAD_ACCEPTCAPSFUNC (pad) = acceptcaps;
1227 GST_CAT_DEBUG (GST_CAT_PADS, "acceptcapsfunc for %s:%s set to %s",
1228 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (acceptcaps));
1229 }
1231 /**
1232 * gst_pad_set_fixatecaps_function:
1233 * @pad: a #GstPad.
1234 * @fixatecaps: the #GstPadFixateCapsFunction to set.
1235 *
1236 * Sets the given fixatecaps function for the pad. The fixatecaps function
1237 * will be called whenever the default values for a GstCaps needs to be
1238 * filled in.
1239 */
1240 void
1241 gst_pad_set_fixatecaps_function (GstPad * pad,
1242 GstPadFixateCapsFunction fixatecaps)
1243 {
1244 g_return_if_fail (GST_IS_PAD (pad));
1246 GST_PAD_FIXATECAPSFUNC (pad) = fixatecaps;
1247 GST_CAT_DEBUG (GST_CAT_PADS, "fixatecapsfunc for %s:%s set to %s",
1248 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (fixatecaps));
1249 }
1251 /**
1252 * gst_pad_set_setcaps_function:
1253 * @pad: a #GstPad.
1254 * @setcaps: the #GstPadSetCapsFunction to set.
1255 *
1256 * Sets the given setcaps function for the pad. The setcaps function
1257 * will be called whenever a buffer with a new media type is pushed or
1258 * pulled from the pad. The pad/element needs to update it's internal
1259 * structures to process the new media type. If this new type is not
1260 * acceptable, the setcaps function should return FALSE.
1261 */
1262 void
1263 gst_pad_set_setcaps_function (GstPad * pad, GstPadSetCapsFunction setcaps)
1264 {
1265 g_return_if_fail (GST_IS_PAD (pad));
1267 GST_PAD_SETCAPSFUNC (pad) = setcaps;
1268 GST_CAT_DEBUG (GST_CAT_PADS, "setcapsfunc for %s:%s set to %s",
1269 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (setcaps));
1270 }
1272 /**
1273 * gst_pad_set_bufferalloc_function:
1274 * @pad: a sink #GstPad.
1275 * @bufalloc: the #GstPadBufferAllocFunction to set.
1276 *
1277 * Sets the given bufferalloc function for the pad. Note that the
1278 * bufferalloc function can only be set on sinkpads.
1279 */
1280 void
1281 gst_pad_set_bufferalloc_function (GstPad * pad,
1282 GstPadBufferAllocFunction bufalloc)
1283 {
1284 g_return_if_fail (GST_IS_PAD (pad));
1285 g_return_if_fail (GST_PAD_IS_SINK (pad));
1287 GST_PAD_BUFFERALLOCFUNC (pad) = bufalloc;
1288 GST_CAT_DEBUG (GST_CAT_PADS, "bufferallocfunc for %s:%s set to %s",
1289 GST_DEBUG_PAD_NAME (pad), GST_DEBUG_FUNCPTR_NAME (bufalloc));
1290 }
1292 /**
1293 * gst_pad_unlink:
1294 * @srcpad: the source #GstPad to unlink.
1295 * @sinkpad: the sink #GstPad to unlink.
1296 *
1297 * Unlinks the source pad from the sink pad. Will emit the "unlinked" signal on
1298 * both pads.
1299 *
1300 * Returns: TRUE if the pads were unlinked. This function returns FALSE if
1301 * the pads were not linked together.
1302 *
1303 * MT safe.
1304 */
1305 gboolean
1306 gst_pad_unlink (GstPad * srcpad, GstPad * sinkpad)
1307 {
1308 g_return_val_if_fail (GST_IS_PAD (srcpad), FALSE);
1309 g_return_val_if_fail (GST_IS_PAD (sinkpad), FALSE);
1311 GST_CAT_INFO (GST_CAT_ELEMENT_PADS, "unlinking %s:%s(%p) and %s:%s(%p)",
1312 GST_DEBUG_PAD_NAME (srcpad), srcpad,
1313 GST_DEBUG_PAD_NAME (sinkpad), sinkpad);
1315 GST_LOCK (srcpad);
1317 if (G_UNLIKELY (GST_PAD_DIRECTION (srcpad) != GST_PAD_SRC))
1318 goto not_srcpad;
1320 GST_LOCK (sinkpad);
1322 if (G_UNLIKELY (GST_PAD_DIRECTION (sinkpad) != GST_PAD_SINK))
1323 goto not_sinkpad;
1325 if (G_UNLIKELY (GST_PAD_PEER (srcpad) != sinkpad))
1326 goto not_linked_together;
1328 if (GST_PAD_UNLINKFUNC (srcpad)) {
1329 GST_PAD_UNLINKFUNC (srcpad) (srcpad);
1330 }
1331 if (GST_PAD_UNLINKFUNC (sinkpad)) {
1332 GST_PAD_UNLINKFUNC (sinkpad) (sinkpad);
1333 }
1335 /* first clear peers */
1336 GST_PAD_PEER (srcpad) = NULL;
1337 GST_PAD_PEER (sinkpad) = NULL;
1339 GST_UNLOCK (sinkpad);
1340 GST_UNLOCK (srcpad);
1342 /* fire off a signal to each of the pads telling them
1343 * that they've been unlinked */
1344 g_signal_emit (G_OBJECT (srcpad), gst_pad_signals[PAD_UNLINKED], 0, sinkpad);
1345 g_signal_emit (G_OBJECT (sinkpad), gst_pad_signals[PAD_UNLINKED], 0, srcpad);
1347 GST_CAT_INFO (GST_CAT_ELEMENT_PADS, "unlinked %s:%s and %s:%s",
1348 GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (sinkpad));
1350 return TRUE;
1352 not_srcpad:
1353 {
1354 g_critical ("pad %s is not a source pad", GST_PAD_NAME (srcpad));
1355 GST_UNLOCK (srcpad);
1356 return FALSE;
1357 }
1358 not_sinkpad:
1359 {
1360 g_critical ("pad %s is not a sink pad", GST_PAD_NAME (sinkpad));
1361 GST_UNLOCK (sinkpad);
1362 GST_UNLOCK (srcpad);
1363 return FALSE;
1364 }
1365 not_linked_together:
1366 {
1367 /* we do not emit a warning in this case because unlinking cannot
1368 * be made MT safe.*/
1369 GST_UNLOCK (sinkpad);
1370 GST_UNLOCK (srcpad);
1371 return FALSE;
1372 }
1373 }
1375 /**
1376 * gst_pad_is_linked:
1377 * @pad: pad to check
1378 *
1379 * Checks if a @pad is linked to another pad or not.
1380 *
1381 * Returns: TRUE if the pad is linked, FALSE otherwise.
1382 *
1383 * MT safe.
1384 */
1385 gboolean
1386 gst_pad_is_linked (GstPad * pad)
1387 {
1388 gboolean result;
1390 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
1392 GST_LOCK (pad);
1393 result = (GST_PAD_PEER (pad) != NULL);
1394 GST_UNLOCK (pad);
1396 return result;
1397 }
1399 /* get the caps from both pads and see if the intersection
1400 * is not empty.
1401 *
1402 * This function should be called with the pad LOCK on both
1403 * pads
1404 */
1405 static gboolean
1406 gst_pad_link_check_compatible_unlocked (GstPad * src, GstPad * sink)
1407 {
1408 GstCaps *srccaps;
1409 GstCaps *sinkcaps;
1411 srccaps = gst_pad_get_caps_unlocked (src);
1412 sinkcaps = gst_pad_get_caps_unlocked (sink);
1413 GST_CAT_DEBUG (GST_CAT_CAPS, " src caps %" GST_PTR_FORMAT, srccaps);
1414 GST_CAT_DEBUG (GST_CAT_CAPS, "sink caps %" GST_PTR_FORMAT, sinkcaps);
1416 /* if we have caps on both pads we can check the intersection */
1417 if (srccaps && sinkcaps) {
1418 GstCaps *icaps;
1420 icaps = gst_caps_intersect (srccaps, sinkcaps);
1421 gst_caps_unref (srccaps);
1422 gst_caps_unref (sinkcaps);
1424 GST_CAT_DEBUG (GST_CAT_CAPS,
1425 "intersection caps %p %" GST_PTR_FORMAT, icaps, icaps);
1427 if (!icaps || gst_caps_is_empty (icaps)) {
1428 GST_CAT_DEBUG (GST_CAT_CAPS, "intersection is empty");
1429 gst_caps_unref (icaps);
1430 return FALSE;
1431 }
1432 gst_caps_unref (icaps);
1433 }
1435 return TRUE;
1436 }
1438 /* check if the grandparents of both pads are the same.
1439 * This check is required so that we don't try to link
1440 * pads from elements in different bins without ghostpads.
1441 *
1442 * The LOCK should be helt on both pads
1443 */
1444 static gboolean
1445 gst_pad_link_check_hierarchy (GstPad * src, GstPad * sink)
1446 {
1447 GstObject *psrc, *psink;
1448 gboolean res = TRUE;
1450 psrc = GST_OBJECT_PARENT (src);
1451 psink = GST_OBJECT_PARENT (sink);
1453 /* if one of the pads has no parent, we allow the link */
1454 if (psrc && psink) {
1455 /* if the parents are the same, we have a loop */
1456 if (psrc == psink) {
1457 GST_CAT_DEBUG (GST_CAT_CAPS, "pads have same parent %" GST_PTR_FORMAT,
1458 psrc);
1459 res = FALSE;
1460 goto done;
1461 }
1462 /* if they both have a parent, we check the grandparents */
1463 psrc = gst_object_get_parent (psrc);
1464 psink = gst_object_get_parent (psink);
1466 if (psrc != psink) {
1467 /* if they have grandparents but they are not the same */
1468 GST_CAT_DEBUG (GST_CAT_CAPS,
1469 "pads have different grandparents %" GST_PTR_FORMAT " and %"
1470 GST_PTR_FORMAT, psrc, psink);
1471 res = FALSE;
1472 }
1473 if (psrc)
1474 gst_object_unref (psrc);
1475 if (psink)
1476 gst_object_unref (psink);
1477 }
1478 done:
1479 return res;
1480 }
1482 /* FIXME leftover from an attempt at refactoring... */
1483 /* call with the two pads unlocked */
1484 static GstPadLinkReturn
1485 gst_pad_link_prepare (GstPad * srcpad, GstPad * sinkpad)
1486 {
1487 /* generic checks */
1488 g_return_val_if_fail (GST_IS_PAD (srcpad), GST_PAD_LINK_REFUSED);
1489 g_return_val_if_fail (GST_IS_PAD (sinkpad), GST_PAD_LINK_REFUSED);
1491 GST_CAT_INFO (GST_CAT_PADS, "trying to link %s:%s and %s:%s",
1492 GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (sinkpad));
1494 GST_LOCK (srcpad);
1496 if (G_UNLIKELY (GST_PAD_DIRECTION (srcpad) != GST_PAD_SRC))
1497 goto not_srcpad;
1499 if (G_UNLIKELY (GST_PAD_PEER (srcpad) != NULL))
1500 goto src_was_linked;
1502 GST_LOCK (sinkpad);
1504 if (G_UNLIKELY (GST_PAD_DIRECTION (sinkpad) != GST_PAD_SINK))
1505 goto not_sinkpad;
1507 if (G_UNLIKELY (GST_PAD_PEER (sinkpad) != NULL))
1508 goto sink_was_linked;
1510 /* check hierarchy, pads can only be linked if the grandparents
1511 * are the same. */
1512 if (!gst_pad_link_check_hierarchy (srcpad, sinkpad))
1513 goto wrong_hierarchy;
1515 /* check pad caps for non-empty intersection */
1516 if (!gst_pad_link_check_compatible_unlocked (srcpad, sinkpad))
1517 goto no_format;
1519 /* FIXME check pad scheduling for non-empty intersection */
1521 return GST_PAD_LINK_OK;
1523 not_srcpad:
1524 {
1525 g_critical ("pad %s is not a source pad", GST_PAD_NAME (srcpad));
1526 GST_UNLOCK (srcpad);
1527 return GST_PAD_LINK_WRONG_DIRECTION;
1528 }
1529 src_was_linked:
1530 {
1531 GST_CAT_INFO (GST_CAT_PADS, "src %s:%s was linked",
1532 GST_DEBUG_PAD_NAME (srcpad));
1533 /* we do not emit a warning in this case because unlinking cannot
1534 * be made MT safe.*/
1535 GST_UNLOCK (srcpad);
1536 return GST_PAD_LINK_WAS_LINKED;
1537 }
1538 not_sinkpad:
1539 {
1540 g_critical ("pad %s is not a sink pad", GST_PAD_NAME (sinkpad));
1541 GST_UNLOCK (sinkpad);
1542 GST_UNLOCK (srcpad);
1543 return GST_PAD_LINK_WRONG_DIRECTION;
1544 }
1545 sink_was_linked:
1546 {
1547 GST_CAT_INFO (GST_CAT_PADS, "sink %s:%s was linked",
1548 GST_DEBUG_PAD_NAME (sinkpad));
1549 /* we do not emit a warning in this case because unlinking cannot
1550 * be made MT safe.*/
1551 GST_UNLOCK (sinkpad);
1552 GST_UNLOCK (srcpad);
1553 return GST_PAD_LINK_WAS_LINKED;
1554 }
1555 wrong_hierarchy:
1556 {
1557 GST_CAT_INFO (GST_CAT_PADS, "pads have wrong hierarchy");
1558 GST_UNLOCK (sinkpad);
1559 GST_UNLOCK (srcpad);
1560 return GST_PAD_LINK_WRONG_HIERARCHY;
1561 }
1562 no_format:
1563 {
1564 GST_CAT_INFO (GST_CAT_PADS, "caps are incompatible");
1565 GST_UNLOCK (sinkpad);
1566 GST_UNLOCK (srcpad);
1567 return GST_PAD_LINK_NOFORMAT;
1568 }
1569 }
1571 /**
1572 * gst_pad_link:
1573 * @srcpad: the source #GstPad to link.
1574 * @sinkpad: the sink #GstPad to link.
1575 *
1576 * Links the source pad and the sink pad.
1577 *
1578 * Returns: A result code indicating if the connection worked or
1579 * what went wrong.
1580 *
1581 * MT Safe.
1582 */
1583 GstPadLinkReturn
1584 gst_pad_link (GstPad * srcpad, GstPad * sinkpad)
1585 {
1586 GstPadLinkReturn result;
1588 /* prepare will also lock the two pads */
1589 result = gst_pad_link_prepare (srcpad, sinkpad);
1591 if (result != GST_PAD_LINK_OK)
1592 goto prepare_failed;
1594 GST_UNLOCK (sinkpad);
1595 GST_UNLOCK (srcpad);
1597 /* FIXME released the locks here, concurrent thread might link
1598 * something else. */
1599 if (GST_PAD_LINKFUNC (srcpad)) {
1600 /* this one will call the peer link function */
1601 result = GST_PAD_LINKFUNC (srcpad) (srcpad, sinkpad);
1602 } else if (GST_PAD_LINKFUNC (sinkpad)) {
1603 /* if no source link function, we need to call the sink link
1604 * function ourselves. */
1605 result = GST_PAD_LINKFUNC (sinkpad) (sinkpad, srcpad);
1606 } else {
1607 result = GST_PAD_LINK_OK;
1608 }
1610 GST_LOCK (srcpad);
1611 GST_LOCK (sinkpad);
1613 if (result == GST_PAD_LINK_OK) {
1614 GST_PAD_PEER (srcpad) = sinkpad;
1615 GST_PAD_PEER (sinkpad) = srcpad;
1617 GST_UNLOCK (sinkpad);
1618 GST_UNLOCK (srcpad);
1620 /* fire off a signal to each of the pads telling them
1621 * that they've been linked */
1622 g_signal_emit (G_OBJECT (srcpad), gst_pad_signals[PAD_LINKED], 0, sinkpad);
1623 g_signal_emit (G_OBJECT (sinkpad), gst_pad_signals[PAD_LINKED], 0, srcpad);
1625 GST_CAT_INFO (GST_CAT_PADS, "linked %s:%s and %s:%s, successful",
1626 GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (sinkpad));
1627 } else {
1628 GST_CAT_INFO (GST_CAT_PADS, "link between %s:%s and %s:%s failed",
1629 GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (sinkpad));
1631 GST_UNLOCK (sinkpad);
1632 GST_UNLOCK (srcpad);
1633 }
1634 return result;
1636 prepare_failed:
1637 {
1638 return result;
1639 }
1640 }
1642 static void
1643 gst_pad_set_pad_template (GstPad * pad, GstPadTemplate * templ)
1644 {
1645 /* this function would need checks if it weren't static */
1647 GST_LOCK (pad);
1648 gst_object_replace ((GstObject **) & pad->padtemplate, (GstObject *) templ);
1649 GST_UNLOCK (pad);
1651 if (templ)
1652 gst_pad_template_pad_created (templ, pad);
1653 }
1655 /**
1656 * gst_pad_get_pad_template:
1657 * @pad: a #GstPad.
1658 *
1659 * Gets the template for @pad.
1660 *
1661 * Returns: the #GstPadTemplate from which this pad was instantiated, or %NULL
1662 * if this pad has no template.
1663 *
1664 * FIXME: currently returns an unrefcounted padtemplate.
1665 */
1666 GstPadTemplate *
1667 gst_pad_get_pad_template (GstPad * pad)
1668 {
1669 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
1671 return GST_PAD_PAD_TEMPLATE (pad);
1672 }
1675 /* should be called with the pad LOCK held */
1676 /* refs the caps, so caller is responsible for getting it unreffed */
1677 static GstCaps *
1678 gst_pad_get_caps_unlocked (GstPad * pad)
1679 {
1680 GstCaps *result = NULL;
1682 GST_CAT_DEBUG (GST_CAT_CAPS, "get pad caps of %s:%s (%p)",
1683 GST_DEBUG_PAD_NAME (pad), pad);
1685 if (GST_PAD_GETCAPSFUNC (pad)) {
1686 GST_CAT_DEBUG (GST_CAT_CAPS, "dispatching to pad getcaps function");
1688 GST_FLAG_SET (pad, GST_PAD_IN_GETCAPS);
1689 GST_UNLOCK (pad);
1690 result = GST_PAD_GETCAPSFUNC (pad) (pad);
1691 GST_LOCK (pad);
1692 GST_FLAG_UNSET (pad, GST_PAD_IN_GETCAPS);
1694 if (result == NULL) {
1695 g_critical ("pad %s:%s returned NULL caps from getcaps function",
1696 GST_DEBUG_PAD_NAME (pad));
1697 } else {
1698 GST_CAT_DEBUG (GST_CAT_CAPS,
1699 "pad getcaps %s:%s returned %" GST_PTR_FORMAT,
1700 GST_DEBUG_PAD_NAME (pad), result);
1701 #ifndef G_DISABLE_ASSERT
1702 /* check that the returned caps are a real subset of the template caps */
1703 if (GST_PAD_PAD_TEMPLATE (pad)) {
1704 const GstCaps *templ_caps =
1705 GST_PAD_TEMPLATE_CAPS (GST_PAD_PAD_TEMPLATE (pad));
1706 if (!gst_caps_is_subset (result, templ_caps)) {
1707 GstCaps *temp;
1709 GST_CAT_ERROR_OBJECT (GST_CAT_CAPS, pad,
1710 "pad returned caps %" GST_PTR_FORMAT
1711 " which are not a real subset of its template caps %"
1712 GST_PTR_FORMAT, result, templ_caps);
1713 g_warning
1714 ("pad %s:%s returned caps that are not a real subset of its template caps",
1715 GST_DEBUG_PAD_NAME (pad));
1716 temp = gst_caps_intersect (templ_caps, result);
1717 gst_caps_unref (result);
1718 result = temp;
1719 }
1720 }
1721 #endif
1722 goto done;
1723 }
1724 }
1725 if (GST_PAD_PAD_TEMPLATE (pad)) {
1726 GstPadTemplate *templ = GST_PAD_PAD_TEMPLATE (pad);
1728 result = GST_PAD_TEMPLATE_CAPS (templ);
1729 GST_CAT_DEBUG (GST_CAT_CAPS,
1730 "using pad template %p with caps %p %" GST_PTR_FORMAT, templ, result,
1731 result);
1733 result = gst_caps_ref (result);
1734 goto done;
1735 }
1736 if (GST_PAD_CAPS (pad)) {
1737 result = GST_PAD_CAPS (pad);
1739 GST_CAT_DEBUG (GST_CAT_CAPS,
1740 "using pad caps %p %" GST_PTR_FORMAT, result, result);
1742 result = gst_caps_ref (result);
1743 goto done;
1744 }
1746 GST_CAT_DEBUG (GST_CAT_CAPS, "pad has no caps");
1747 result = gst_caps_new_empty ();
1749 done:
1750 return result;
1751 }
1753 /**
1754 * gst_pad_get_caps:
1755 * @pad: a #GstPad to get the capabilities of.
1756 *
1757 * Gets the capabilities this pad can produce or consume.
1758 * Note that this method doesn't necessarily returns the caps set by
1759 * #gst_pad_set_caps - use #GST_PAD_CAPS for that instead.
1760 * gst_pad_get_caps returns all possible caps a pad can operate with, using
1761 * the pad's get_caps function;
1762 * this returns the pad template caps if not explicitly set.
1763 *
1764 * Returns: a newly allocated copy of the #GstCaps of this pad.
1765 *
1766 * MT safe.
1767 */
1768 GstCaps *
1769 gst_pad_get_caps (GstPad * pad)
1770 {
1771 GstCaps *result = NULL;
1773 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
1775 GST_LOCK (pad);
1777 GST_CAT_DEBUG (GST_CAT_CAPS, "get pad caps of %s:%s (%p)",
1778 GST_DEBUG_PAD_NAME (pad), pad);
1780 if (G_UNLIKELY (GST_PAD_IS_IN_GETCAPS (pad)))
1781 goto was_dispatching;
1783 result = gst_pad_get_caps_unlocked (pad);
1784 GST_UNLOCK (pad);
1786 return result;
1788 was_dispatching:
1789 {
1790 GST_CAT_DEBUG (GST_CAT_CAPS,
1791 "pad %s:%s is already dispatching!", GST_DEBUG_PAD_NAME (pad));
1792 g_warning ("pad %s:%s recursively called getcaps!",
1793 GST_DEBUG_PAD_NAME (pad));
1794 GST_UNLOCK (pad);
1795 return NULL;
1796 }
1797 }
1799 /**
1800 * gst_pad_peer_get_caps:
1801 * @pad: a #GstPad to get the peer capabilities of.
1802 *
1803 * Gets the capabilities of the peer connected to this pad.
1804 *
1805 * Returns: the #GstCaps of the peer pad. This function returns a new caps, so use
1806 * gst_caps_unref to get rid of it. this function returns NULL if there is no
1807 * peer pad or when this function is called recursively from a getcaps function.
1808 */
1809 GstCaps *
1810 gst_pad_peer_get_caps (GstPad * pad)
1811 {
1812 GstPad *peerpad;
1813 GstCaps *result = NULL;
1815 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
1817 GST_LOCK (pad);
1819 GST_CAT_DEBUG (GST_CAT_CAPS, "get peer caps of %s:%s (%p)",
1820 GST_DEBUG_PAD_NAME (pad), pad);
1822 peerpad = GST_PAD_PEER (pad);
1823 if (G_UNLIKELY (peerpad == NULL))
1824 goto no_peer;
1826 if (G_UNLIKELY (GST_PAD_IS_IN_GETCAPS (peerpad)))
1827 goto was_dispatching;
1829 gst_object_ref (peerpad);
1830 GST_UNLOCK (pad);
1832 result = gst_pad_get_caps (peerpad);
1834 gst_object_unref (peerpad);
1836 return result;
1838 no_peer:
1839 {
1840 GST_UNLOCK (pad);
1841 return NULL;
1842 }
1843 was_dispatching:
1844 {
1845 GST_CAT_DEBUG (GST_CAT_CAPS,
1846 "pad %s:%s is already dispatching!", GST_DEBUG_PAD_NAME (pad));
1847 g_warning ("pad %s:%s recursively called getcaps!",
1848 GST_DEBUG_PAD_NAME (pad));
1849 GST_UNLOCK (pad);
1850 return NULL;
1851 }
1852 }
1854 static gboolean
1855 fixate_value (GValue * dest, const GValue * src)
1856 {
1857 if (G_VALUE_TYPE (src) == GST_TYPE_INT_RANGE) {
1858 g_value_init (dest, G_TYPE_INT);
1859 g_value_set_int (dest, gst_value_get_int_range_min (src));
1860 } else if (G_VALUE_TYPE (src) == GST_TYPE_DOUBLE_RANGE) {
1861 g_value_init (dest, G_TYPE_DOUBLE);
1862 g_value_set_double (dest, gst_value_get_double_range_min (src));
1863 } else if (G_VALUE_TYPE (src) == GST_TYPE_LIST) {
1864 GValue temp = { 0 };
1866 gst_value_init_and_copy (&temp, gst_value_list_get_value (src, 0));
1867 if (!fixate_value (dest, &temp))
1868 gst_value_init_and_copy (dest, &temp);
1869 g_value_unset (&temp);
1870 } else if (G_VALUE_TYPE (src) == GST_TYPE_ARRAY) {
1871 gboolean res = FALSE;
1872 gint n;
1874 g_value_init (dest, GST_TYPE_ARRAY);
1875 for (n = 0; n < gst_value_list_get_size (src); n++) {
1876 GValue kid = { 0 };
1877 const GValue *orig_kid = gst_value_list_get_value (src, n);
1879 if (!fixate_value (&kid, orig_kid))
1880 gst_value_init_and_copy (&kid, orig_kid);
1881 else
1882 res = TRUE;
1883 gst_value_list_append_value (dest, &kid);
1884 g_value_unset (&kid);
1885 }
1887 if (!res)
1888 g_value_unset (dest);
1890 return res;
1891 } else {
1892 return FALSE;
1893 }
1895 return TRUE;
1896 }
1898 static gboolean
1899 gst_pad_default_fixate (GQuark field_id, const GValue * value, gpointer data)
1900 {
1901 GstStructure *s = data;
1902 GValue v = { 0 };
1904 if (fixate_value (&v, value)) {
1905 gst_structure_id_set_value (s, field_id, &v);
1906 g_value_unset (&v);
1907 }
1909 return TRUE;
1910 }
1912 /**
1913 * gst_pad_fixate_caps:
1914 * @pad: a #GstPad to fixate
1915 * @caps: the #GstCaps to fixate
1916 *
1917 * Fixate a caps on the given pad. Modifies the caps in place, so you should
1918 * make sure that the caps are actually writable (see gst_caps_make_writable()).
1919 */
1920 void
1921 gst_pad_fixate_caps (GstPad * pad, GstCaps * caps)
1922 {
1923 GstPadFixateCapsFunction fixatefunc;
1924 gint n;
1926 g_return_if_fail (GST_IS_PAD (pad));
1927 g_return_if_fail (caps != NULL);
1929 if (gst_caps_is_fixed (caps))
1930 return;
1932 fixatefunc = GST_PAD_FIXATECAPSFUNC (pad);
1933 if (fixatefunc) {
1934 fixatefunc (pad, caps);
1935 }
1937 /* default fixation */
1938 for (n = 0; n < gst_caps_get_size (caps); n++) {
1939 GstStructure *s = gst_caps_get_structure (caps, n);
1941 gst_structure_foreach (s, gst_pad_default_fixate, s);
1942 }
1943 }
1945 /**
1946 * gst_pad_accept_caps:
1947 * @pad: a #GstPad to check
1948 * @caps: a #GstCaps to check on the pad
1949 *
1950 * Check if the given pad accepts the caps.
1951 *
1952 * Returns: TRUE if the pad can accept the caps.
1953 */
1954 gboolean
1955 gst_pad_accept_caps (GstPad * pad, GstCaps * caps)
1956 {
1957 gboolean result;
1958 GstPadAcceptCapsFunction acceptfunc;
1960 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
1962 /* any pad can be unnegotiated */
1963 if (caps == NULL)
1964 return TRUE;
1966 GST_LOCK (pad);
1967 acceptfunc = GST_PAD_ACCEPTCAPSFUNC (pad);
1969 GST_CAT_DEBUG (GST_CAT_CAPS, "pad accept caps of %s:%s (%p)",
1970 GST_DEBUG_PAD_NAME (pad), pad);
1971 GST_UNLOCK (pad);
1973 if (acceptfunc) {
1974 /* we can call the function */
1975 result = acceptfunc (pad, caps);
1976 } else {
1977 /* else see get the caps and see if it intersects to something
1978 * not empty */
1979 GstCaps *intersect;
1980 GstCaps *allowed;
1982 allowed = gst_pad_get_caps (pad);
1983 if (allowed) {
1984 intersect = gst_caps_intersect (allowed, caps);
1986 result = !gst_caps_is_empty (intersect);
1988 gst_caps_unref (allowed);
1989 gst_caps_unref (intersect);
1990 } else {
1991 result = FALSE;
1992 }
1993 }
1994 return result;
1995 }
1997 /**
1998 * gst_pad_peer_accept_caps:
1999 * @pad: a #GstPad to check
2000 * @caps: a #GstCaps to check on the pad
2001 *
2002 * Check if the given pad accepts the caps.
2003 *
2004 * Returns: TRUE if the pad can accept the caps.
2005 */
2006 gboolean
2007 gst_pad_peer_accept_caps (GstPad * pad, GstCaps * caps)
2008 {
2009 GstPad *peerpad;
2010 gboolean result;
2012 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2014 GST_LOCK (pad);
2016 GST_CAT_DEBUG (GST_CAT_CAPS, "peer accept caps of %s:%s (%p)",
2017 GST_DEBUG_PAD_NAME (pad), pad);
2019 peerpad = GST_PAD_PEER (pad);
2020 if (G_UNLIKELY (peerpad == NULL))
2021 goto no_peer;
2023 result = gst_pad_accept_caps (peerpad, caps);
2024 GST_UNLOCK (pad);
2026 return result;
2028 no_peer:
2029 {
2030 GST_UNLOCK (pad);
2031 return TRUE;
2032 }
2033 }
2035 /**
2036 * gst_pad_set_caps:
2037 * @pad: a #GstPad to set the capabilities of.
2038 * @caps: a #GstCaps to set.
2039 *
2040 * Sets the capabilities of this pad. The caps must be fixed. Any previous
2041 * caps on the pad will be unreffed. This function refs the caps so you should
2042 * unref if as soon as you don't need it anymore.
2043 * It is possible to set NULL caps, which will make the pad unnegotiated
2044 * again.
2045 *
2046 * Returns: TRUE if the caps could be set. FALSE if the caps were not fixed
2047 * or bad parameters were provided to this function.
2048 *
2049 * MT safe.
2050 */
2051 gboolean
2052 gst_pad_set_caps (GstPad * pad, GstCaps * caps)
2053 {
2054 GstPadSetCapsFunction setcaps;
2055 GstCaps *existing;
2057 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2058 g_return_val_if_fail (caps == NULL || gst_caps_is_fixed (caps), FALSE);
2060 GST_LOCK (pad);
2061 setcaps = GST_PAD_SETCAPSFUNC (pad);
2063 existing = GST_PAD_CAPS (pad);
2064 if (caps == existing)
2065 goto setting_same_caps;
2066 else if (caps && existing && gst_caps_is_equal (caps, existing))
2067 goto setting_same_caps;
2069 /* call setcaps function to configure the pad */
2070 if (setcaps != NULL && caps) {
2071 if (!GST_PAD_IS_IN_SETCAPS (pad)) {
2072 GST_FLAG_SET (pad, GST_PAD_IN_SETCAPS);
2073 GST_UNLOCK (pad);
2074 if (!setcaps (pad, caps))
2075 goto could_not_set;
2076 GST_LOCK (pad);
2077 GST_FLAG_UNSET (pad, GST_PAD_IN_SETCAPS);
2078 } else {
2079 GST_CAT_DEBUG (GST_CAT_CAPS, "pad %s:%s was dispatching",
2080 GST_DEBUG_PAD_NAME (pad));
2081 }
2082 }
2084 gst_caps_replace (&GST_PAD_CAPS (pad), caps);
2085 GST_CAT_DEBUG (GST_CAT_CAPS, "%s:%s caps %" GST_PTR_FORMAT,
2086 GST_DEBUG_PAD_NAME (pad), caps);
2087 GST_UNLOCK (pad);
2089 g_object_notify (G_OBJECT (pad), "caps");
2091 return TRUE;
2093 setting_same_caps:
2094 {
2095 GST_UNLOCK (pad);
2096 gst_caps_replace (&GST_PAD_CAPS (pad), caps);
2097 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
2098 "caps %" GST_PTR_FORMAT " same as existing, updating ptr only", caps);
2099 return TRUE;
2100 }
2101 /* errors */
2102 could_not_set:
2103 {
2104 GST_LOCK (pad);
2105 GST_FLAG_UNSET (pad, GST_PAD_IN_SETCAPS);
2106 GST_CAT_DEBUG (GST_CAT_CAPS,
2107 "pad %s:%s, caps %" GST_PTR_FORMAT " could not be set",
2108 GST_DEBUG_PAD_NAME (pad), caps);
2109 GST_UNLOCK (pad);
2111 return FALSE;
2112 }
2113 }
2115 static gboolean
2116 gst_pad_configure_sink (GstPad * pad, GstCaps * caps)
2117 {
2118 GstPadAcceptCapsFunction acceptcaps;
2119 GstPadSetCapsFunction setcaps;
2120 gboolean res;
2122 acceptcaps = GST_PAD_ACCEPTCAPSFUNC (pad);
2123 setcaps = GST_PAD_SETCAPSFUNC (pad);
2125 /* See if pad accepts the caps, by calling acceptcaps, only
2126 * needed if no setcaps function */
2127 if (setcaps == NULL && acceptcaps != NULL) {
2128 if (!acceptcaps (pad, caps))
2129 goto not_accepted;
2130 }
2131 /* set caps on pad if call succeeds */
2132 res = gst_pad_set_caps (pad, caps);
2133 /* no need to unref the caps here, set_caps takes a ref and
2134 * our ref goes away when we leave this function. */
2136 return res;
2138 not_accepted:
2139 {
2140 GST_CAT_DEBUG (GST_CAT_CAPS, "caps %" GST_PTR_FORMAT " not accepted", caps);
2141 return FALSE;
2142 }
2143 }
2145 /* returns TRUE if the src pad could be configured to accept the given caps */
2146 static gboolean
2147 gst_pad_configure_src (GstPad * pad, GstCaps * caps)
2148 {
2149 GstPadAcceptCapsFunction acceptcaps;
2150 GstPadSetCapsFunction setcaps;
2151 gboolean res;
2153 acceptcaps = GST_PAD_ACCEPTCAPSFUNC (pad);
2154 setcaps = GST_PAD_SETCAPSFUNC (pad);
2156 /* See if pad accepts the caps, by calling acceptcaps, only
2157 * needed if no setcaps function */
2158 if (setcaps == NULL && acceptcaps != NULL) {
2159 if (!acceptcaps (pad, caps))
2160 goto not_accepted;
2161 }
2162 /* set caps on pad if call succeeds */
2163 res = gst_pad_set_caps (pad, caps);
2164 /* no need to unref the caps here, set_caps takes a ref and
2165 * our ref goes away when we leave this function. */
2167 return res;
2169 not_accepted:
2170 {
2171 GST_CAT_DEBUG (GST_CAT_CAPS, "caps %" GST_PTR_FORMAT " not accepted", caps);
2172 return FALSE;
2173 }
2174 }
2176 /**
2177 * gst_pad_get_pad_template_caps:
2178 * @pad: a #GstPad to get the template capabilities from.
2179 *
2180 * Gets the capabilities for @pad's template.
2181 *
2182 * Returns: the #GstCaps of this pad template. If you intend to keep a reference
2183 * on the caps, make a copy (see gst_caps_copy ()).
2184 */
2185 const GstCaps *
2186 gst_pad_get_pad_template_caps (GstPad * pad)
2187 {
2188 static GstStaticCaps anycaps = GST_STATIC_CAPS ("ANY");
2190 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2192 if (GST_PAD_PAD_TEMPLATE (pad))
2193 return GST_PAD_TEMPLATE_CAPS (GST_PAD_PAD_TEMPLATE (pad));
2195 return gst_static_caps_get (&anycaps);
2196 }
2199 /**
2200 * gst_pad_get_peer:
2201 * @pad: a #GstPad to get the peer of.
2202 *
2203 * Gets the peer of @pad. This function refs the peer pad so
2204 * you need to unref it after use.
2205 *
2206 * Returns: the peer #GstPad. Unref after usage.
2207 *
2208 * MT safe.
2209 */
2210 GstPad *
2211 gst_pad_get_peer (GstPad * pad)
2212 {
2213 GstPad *result;
2215 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2217 GST_LOCK (pad);
2218 result = GST_PAD_PEER (pad);
2219 if (result)
2220 gst_object_ref (result);
2221 GST_UNLOCK (pad);
2223 return result;
2224 }
2226 /**
2227 * gst_pad_get_allowed_caps:
2228 * @srcpad: a #GstPad, it must a a source pad.
2229 *
2230 * Gets the capabilities of the allowed media types that can flow through
2231 * @srcpad and its peer. The pad must be a source pad.
2232 * The caller must free the resulting caps.
2233 *
2234 * Returns: the allowed #GstCaps of the pad link. Free the caps when
2235 * you no longer need it. This function returns NULL when the @srcpad has no
2236 * peer.
2237 *
2238 * MT safe.
2239 */
2240 GstCaps *
2241 gst_pad_get_allowed_caps (GstPad * srcpad)
2242 {
2243 GstCaps *mycaps;
2244 GstCaps *caps;
2245 GstCaps *peercaps;
2246 GstPad *peer;
2248 g_return_val_if_fail (GST_IS_PAD (srcpad), NULL);
2249 g_return_val_if_fail (GST_PAD_IS_SRC (srcpad), NULL);
2251 GST_LOCK (srcpad);
2253 peer = GST_PAD_PEER (srcpad);
2254 if (G_UNLIKELY (peer == NULL))
2255 goto no_peer;
2257 GST_CAT_DEBUG (GST_CAT_PROPERTIES, "%s:%s: getting allowed caps",
2258 GST_DEBUG_PAD_NAME (srcpad));
2260 gst_object_ref (peer);
2261 GST_UNLOCK (srcpad);
2262 mycaps = gst_pad_get_caps (srcpad);
2264 peercaps = gst_pad_get_caps (peer);
2265 gst_object_unref (peer);
2267 caps = gst_caps_intersect (mycaps, peercaps);
2268 gst_caps_unref (peercaps);
2269 gst_caps_unref (mycaps);
2271 GST_CAT_DEBUG (GST_CAT_CAPS, "allowed caps %" GST_PTR_FORMAT, caps);
2273 return caps;
2275 no_peer:
2276 {
2277 GST_CAT_DEBUG (GST_CAT_PROPERTIES, "%s:%s: no peer",
2278 GST_DEBUG_PAD_NAME (srcpad));
2279 GST_UNLOCK (srcpad);
2281 return NULL;
2282 }
2283 }
2285 /**
2286 * gst_pad_get_negotiated_caps:
2287 * @pad: a #GstPad.
2288 *
2289 * Gets the capabilities of the media type that currently flows through @pad
2290 * and its peer.
2291 *
2292 * This function can be used on both src and sinkpads. Note that srcpads are
2293 * always negotiated before sinkpads so it is possible that the negotiated caps
2294 * on the srcpad do not match the negotiated caps of the peer.
2295 *
2296 * Returns: the negotiated #GstCaps of the pad link. Free the caps when
2297 * you no longer need it. This function returns NULL when the @pad has no
2298 * peer or is not negotiated yet.
2299 *
2300 * MT safe.
2301 */
2302 GstCaps *
2303 gst_pad_get_negotiated_caps (GstPad * pad)
2304 {
2305 GstCaps *caps;
2306 GstPad *peer;
2308 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2310 GST_LOCK (pad);
2312 if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
2313 goto no_peer;
2315 GST_CAT_DEBUG (GST_CAT_PROPERTIES, "%s:%s: getting negotiated caps",
2316 GST_DEBUG_PAD_NAME (pad));
2318 caps = GST_PAD_CAPS (pad);
2319 if (caps)
2320 gst_caps_ref (caps);
2321 GST_UNLOCK (pad);
2323 GST_CAT_DEBUG (GST_CAT_CAPS, "negotiated caps %" GST_PTR_FORMAT, caps);
2325 return caps;
2327 no_peer:
2328 {
2329 GST_CAT_DEBUG (GST_CAT_PROPERTIES, "%s:%s: no peer",
2330 GST_DEBUG_PAD_NAME (pad));
2331 GST_UNLOCK (pad);
2333 return NULL;
2334 }
2335 }
2337 /**
2338 * gst_pad_alloc_buffer:
2339 * @pad: a source #GstPad
2340 * @offset: the offset of the new buffer in the stream
2341 * @size: the size of the new buffer
2342 * @caps: the caps of the new buffer
2343 * @buf: a newly allocated buffer
2344 *
2345 * Allocates a new, empty buffer optimized to push to pad @pad. This
2346 * function only works if @pad is a source pad and has a peer.
2347 *
2348 * You need to check the caps of the buffer after performing this
2349 * function and renegotiate to the format if needed.
2350 *
2351 * A new, empty #GstBuffer will be put in the @buf argument.
2352 *
2353 * Returns: a result code indicating success of the operation. Any
2354 * result code other than GST_FLOW_OK is an error and @buf should
2355 * not be used.
2356 * An error can occur if the pad is not connected or when the downstream
2357 * peer elements cannot provide an acceptable buffer.
2358 *
2359 * MT safe.
2360 */
2361 GstFlowReturn
2362 gst_pad_alloc_buffer (GstPad * pad, guint64 offset, gint size, GstCaps * caps,
2363 GstBuffer ** buf)
2364 {
2365 GstPad *peer;
2366 GstFlowReturn ret;
2367 GstPadBufferAllocFunction bufferallocfunc;
2368 gboolean caps_changed;
2370 g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
2371 g_return_val_if_fail (GST_PAD_IS_SRC (pad), GST_FLOW_ERROR);
2372 g_return_val_if_fail (buf != NULL, GST_FLOW_ERROR);
2374 GST_LOCK (pad);
2375 while (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad)))
2376 handle_pad_block (pad);
2378 if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
2379 goto no_peer;
2381 gst_object_ref (peer);
2382 GST_UNLOCK (pad);
2384 if (G_LIKELY ((bufferallocfunc = peer->bufferallocfunc) == NULL))
2385 goto fallback;
2387 GST_LOCK (peer);
2388 /* when the peer is flushing we cannot give a buffer */
2389 if (G_UNLIKELY (GST_PAD_IS_FLUSHING (peer)))
2390 goto flushing;
2392 if (offset == GST_BUFFER_OFFSET_NONE) {
2393 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
2394 "calling bufferallocfunc &%s (@%p) of peer pad %s:%s for size %d offset NONE",
2395 GST_DEBUG_FUNCPTR_NAME (bufferallocfunc),
2396 &bufferallocfunc, GST_DEBUG_PAD_NAME (peer), size);
2397 } else {
2398 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
2399 "calling bufferallocfunc &%s (@%p) of peer pad %s:%s for size %d offset %"
2400 G_GUINT64_FORMAT, GST_DEBUG_FUNCPTR_NAME (bufferallocfunc),
2401 &bufferallocfunc, GST_DEBUG_PAD_NAME (peer), size, offset);
2402 }
2403 GST_UNLOCK (peer);
2405 ret = bufferallocfunc (peer, offset, size, caps, buf);
2407 if (G_UNLIKELY (ret != GST_FLOW_OK))
2408 goto peer_error;
2409 if (G_UNLIKELY (*buf == NULL))
2410 goto fallback;
2412 /* If the buffer alloc function didn't set up the caps like it should,
2413 * do it for it */
2414 if (caps && (GST_BUFFER_CAPS (*buf) == NULL)) {
2415 GST_WARNING ("Buffer allocation function for pad % " GST_PTR_FORMAT
2416 " did not set up caps. Setting", peer);
2418 gst_buffer_set_caps (*buf, caps);
2419 }
2421 do_caps:
2422 gst_object_unref (peer);
2424 /* FIXME, move capnego this into a base class? */
2425 caps = GST_BUFFER_CAPS (*buf);
2426 caps_changed = caps && caps != GST_PAD_CAPS (pad);
2427 /* we got a new datatype on the pad, see if it can handle it */
2428 if (G_UNLIKELY (caps_changed)) {
2429 GST_DEBUG ("caps changed to %" GST_PTR_FORMAT, caps);
2430 if (G_UNLIKELY (!gst_pad_configure_src (pad, caps)))
2431 goto not_negotiated;
2432 }
2433 return ret;
2435 no_peer:
2436 {
2437 /* pad has no peer */
2438 GST_CAT_DEBUG (GST_CAT_PADS,
2439 "%s:%s called bufferallocfunc but had no peer",
2440 GST_DEBUG_PAD_NAME (pad));
2441 GST_UNLOCK (pad);
2442 return GST_FLOW_NOT_LINKED;
2443 }
2444 flushing:
2445 {
2446 /* peer was flushing */
2447 GST_UNLOCK (peer);
2448 gst_object_unref (peer);
2449 GST_CAT_DEBUG (GST_CAT_PADS,
2450 "%s:%s called bufferallocfunc but peer was flushing",
2451 GST_DEBUG_PAD_NAME (pad));
2452 return GST_FLOW_WRONG_STATE;
2453 }
2454 /* fallback case, allocate a buffer of our own, add pad caps. */
2455 fallback:
2456 {
2457 GST_CAT_DEBUG (GST_CAT_PADS,
2458 "%s:%s fallback buffer alloc", GST_DEBUG_PAD_NAME (pad));
2459 *buf = gst_buffer_new_and_alloc (size);
2460 GST_BUFFER_OFFSET (*buf) = offset;
2461 gst_buffer_set_caps (*buf, caps);
2463 ret = GST_FLOW_OK;
2465 goto do_caps;
2466 }
2467 not_negotiated:
2468 {
2469 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
2470 "alloc function retured unacceptable buffer");
2471 return GST_FLOW_NOT_NEGOTIATED;
2472 }
2473 peer_error:
2474 {
2475 gst_object_unref (peer);
2476 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
2477 "alloc function retured error %s", gst_flow_get_name (ret));
2478 return ret;
2479 }
2480 }
2482 /**
2483 * gst_pad_get_internal_links_default:
2484 * @pad: the #GstPad to get the internal links of.
2485 *
2486 * Gets a list of pads to which the given pad is linked to
2487 * inside of the parent element.
2488 * This is the default handler, and thus returns a list of all of the
2489 * pads inside the parent element with opposite direction.
2490 * The caller must free this list after use.
2491 *
2492 * Returns: a newly allocated #GList of pads, or NULL if the pad has no parent.
2493 *
2494 * Not MT safe.
2495 */
2496 GList *
2497 gst_pad_get_internal_links_default (GstPad * pad)
2498 {
2499 GList *res = NULL;
2500 GstElement *parent;
2501 GList *parent_pads;
2502 GstPadDirection direction;
2504 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2506 direction = pad->direction;
2508 parent = GST_PAD_PARENT (pad);
2509 if (!parent)
2510 return NULL;
2512 parent_pads = parent->pads;
2514 while (parent_pads) {
2515 GstPad *parent_pad = GST_PAD_CAST (parent_pads->data);
2517 if (parent_pad->direction != direction) {
2518 res = g_list_prepend (res, parent_pad);
2519 }
2521 parent_pads = g_list_next (parent_pads);
2522 }
2524 return res;
2525 }
2527 /**
2528 * gst_pad_get_internal_links:
2529 * @pad: the #GstPad to get the internal links of.
2530 *
2531 * Gets a list of pads to which the given pad is linked to
2532 * inside of the parent element.
2533 * The caller must free this list after use.
2534 *
2535 * Returns: a newly allocated #GList of pads.
2536 *
2537 * Not MT safe.
2538 */
2539 GList *
2540 gst_pad_get_internal_links (GstPad * pad)
2541 {
2542 GList *res = NULL;
2544 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2546 if (GST_PAD_INTLINKFUNC (pad))
2547 res = GST_PAD_INTLINKFUNC (pad) (pad);
2549 return res;
2550 }
2553 static gboolean
2554 gst_pad_event_default_dispatch (GstPad * pad, GstEvent * event)
2555 {
2556 GList *orig, *pads;
2557 gboolean result;
2559 GST_INFO_OBJECT (pad, "Sending event %p to all internally linked pads",
2560 event);
2562 result = (GST_PAD_DIRECTION (pad) == GST_PAD_SINK);
2564 orig = pads = gst_pad_get_internal_links (pad);
2566 while (pads) {
2567 GstPad *eventpad = GST_PAD_CAST (pads->data);
2569 pads = g_list_next (pads);
2571 /* for all of the internally-linked pads that are actually linked */
2572 if (GST_PAD_IS_LINKED (eventpad)) {
2573 if (GST_PAD_DIRECTION (eventpad) == GST_PAD_SRC) {
2574 /* for each pad we send to, we should ref the event; it's up
2575 * to downstream to unref again when handled. */
2576 GST_LOG_OBJECT (pad, "Reffing and sending event %p to %s:%s", event,
2577 GST_DEBUG_PAD_NAME (eventpad));
2578 gst_event_ref (event);
2579 gst_pad_push_event (eventpad, event);
2580 } else {
2581 /* we only send the event on one pad, multi-sinkpad elements
2582 * should implement a handler */
2583 GST_LOG_OBJECT (pad, "sending event %p to one sink pad %s:%s", event,
2584 GST_DEBUG_PAD_NAME (eventpad));
2585 result = gst_pad_push_event (eventpad, event);
2586 goto done;
2587 }
2588 }
2589 }
2590 /* we handled the incoming event so we unref once */
2591 GST_LOG_OBJECT (pad, "handled event %p, unreffing", event);
2592 gst_event_unref (event);
2594 done:
2595 g_list_free (orig);
2597 return result;
2598 }
2600 /**
2601 * gst_pad_event_default:
2602 * @pad: a #GstPad to call the default event handler on.
2603 * @event: the #GstEvent to handle.
2604 *
2605 * Invokes the default event handler for the given pad. End-of-stream and
2606 * discontinuity events are handled specially, and then the event is sent to all
2607 * pads internally linked to @pad. Note that if there are many possible sink
2608 * pads that are internally linked to @pad, only one will be sent an event.
2609 * Multi-sinkpad elements should implement custom event handlers.
2610 *
2611 * Returns: TRUE if the event was sent succesfully.
2612 */
2613 gboolean
2614 gst_pad_event_default (GstPad * pad, GstEvent * event)
2615 {
2616 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2617 g_return_val_if_fail (event != NULL, FALSE);
2619 switch (GST_EVENT_TYPE (event)) {
2620 case GST_EVENT_EOS:
2621 {
2622 GST_DEBUG_OBJECT (pad, "pausing task because of eos");
2623 gst_pad_pause_task (pad);
2624 }
2625 default:
2626 break;
2627 }
2629 return gst_pad_event_default_dispatch (pad, event);
2630 }
2632 /**
2633 * gst_pad_dispatcher:
2634 * @pad: a #GstPad to dispatch.
2635 * @dispatch: the #GstDispatcherFunction to call.
2636 * @data: gpointer user data passed to the dispatcher function.
2637 *
2638 * Invokes the given dispatcher function on all pads that are
2639 * internally linked to the given pad.
2640 * The GstPadDispatcherFunction should return TRUE when no further pads
2641 * need to be processed.
2642 *
2643 * Returns: TRUE if one of the dispatcher functions returned TRUE.
2644 */
2645 gboolean
2646 gst_pad_dispatcher (GstPad * pad, GstPadDispatcherFunction dispatch,
2647 gpointer data)
2648 {
2649 gboolean res = FALSE;
2650 GList *int_pads, *orig;
2652 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2653 g_return_val_if_fail (dispatch != NULL, FALSE);
2655 orig = int_pads = gst_pad_get_internal_links (pad);
2657 while (int_pads) {
2658 GstPad *int_pad = GST_PAD_CAST (int_pads->data);
2659 GstPad *int_peer = GST_PAD_PEER (int_pad);
2661 if (int_peer) {
2662 res = dispatch (int_peer, data);
2663 if (res)
2664 break;
2665 }
2666 int_pads = g_list_next (int_pads);
2667 }
2669 g_list_free (orig);
2671 return res;
2672 }
2674 /**
2675 * gst_pad_query:
2676 * @pad: a #GstPad to invoke the default query on.
2677 * @query: the #GstQuery to perform.
2678 *
2679 * Dispatches a query to a pad. The query should have been allocated by the
2680 * caller via one of the type-specific allocation functions in gstquery.h. The
2681 * element is responsible for filling the query with an appropriate response,
2682 * which should then be parsed with a type-specific query parsing function.
2683 *
2684 * Again, the caller is responsible for both the allocation and deallocation of
2685 * the query structure.
2686 *
2687 * Returns: TRUE if the query could be performed.
2688 */
2689 gboolean
2690 gst_pad_query (GstPad * pad, GstQuery * query)
2691 {
2692 GstPadQueryFunction func;
2694 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2695 g_return_val_if_fail (GST_IS_QUERY (query), FALSE);
2697 GST_DEBUG ("sending query %p to pad %s:%s", query, GST_DEBUG_PAD_NAME (pad));
2699 if ((func = GST_PAD_QUERYFUNC (pad)) == NULL)
2700 goto no_func;
2702 return func (pad, query);
2704 no_func:
2705 {
2706 GST_DEBUG ("pad had no query function");
2707 return FALSE;
2708 }
2709 }
2711 gboolean
2712 gst_pad_query_default (GstPad * pad, GstQuery * query)
2713 {
2714 switch (GST_QUERY_TYPE (query)) {
2715 case GST_QUERY_POSITION:
2716 case GST_QUERY_SEEKING:
2717 case GST_QUERY_FORMATS:
2718 case GST_QUERY_LATENCY:
2719 case GST_QUERY_JITTER:
2720 case GST_QUERY_RATE:
2721 case GST_QUERY_CONVERT:
2722 default:
2723 return gst_pad_dispatcher
2724 (pad, (GstPadDispatcherFunction) gst_pad_query, query);
2725 }
2726 }
2728 #ifndef GST_DISABLE_LOADSAVE
2729 /* FIXME: why isn't this on a GstElement ? */
2730 /**
2731 * gst_pad_load_and_link:
2732 * @self: an #xmlNodePtr to read the description from.
2733 * @parent: the #GstObject element that owns the pad.
2734 *
2735 * Reads the pad definition from the XML node and links the given pad
2736 * in the element to a pad of an element up in the hierarchy.
2737 */
2738 void
2739 gst_pad_load_and_link (xmlNodePtr self, GstObject * parent)
2740 {
2741 xmlNodePtr field = self->xmlChildrenNode;
2742 GstPad *pad = NULL, *targetpad;
2743 gchar *peer = NULL;
2744 gchar **split;
2745 GstElement *target;
2746 GstObject *grandparent;
2747 gchar *name = NULL;
2749 while (field) {
2750 if (!strcmp ((char *) field->name, "name")) {
2751 name = (gchar *) xmlNodeGetContent (field);
2752 pad = gst_element_get_pad (GST_ELEMENT (parent), name);
2753 g_free (name);
2754 } else if (!strcmp ((char *) field->name, "peer")) {
2755 peer = (gchar *) xmlNodeGetContent (field);
2756 }
2757 field = field->next;
2758 }
2759 g_return_if_fail (pad != NULL);
2761 if (peer == NULL)
2762 return;
2764 split = g_strsplit (peer, ".", 2);
2766 if (split[0] == NULL || split[1] == NULL) {
2767 GST_CAT_DEBUG (GST_CAT_XML,
2768 "Could not parse peer '%s' for pad %s:%s, leaving unlinked",
2769 peer, GST_DEBUG_PAD_NAME (pad));
2771 g_free (peer);
2772 return;
2773 }
2774 g_free (peer);
2776 g_return_if_fail (split[0] != NULL);
2777 g_return_if_fail (split[1] != NULL);
2779 grandparent = gst_object_get_parent (parent);
2781 if (grandparent && GST_IS_BIN (grandparent)) {
2782 target = gst_bin_get_by_name_recurse_up (GST_BIN (grandparent), split[0]);
2783 } else
2784 goto cleanup;
2786 if (target == NULL)
2787 goto cleanup;
2789 targetpad = gst_element_get_pad (target, split[1]);
2791 if (targetpad == NULL)
2792 goto cleanup;
2794 gst_pad_link (pad, targetpad);
2796 cleanup:
2797 g_strfreev (split);
2798 }
2800 /**
2801 * gst_pad_save_thyself:
2802 * @pad: a #GstPad to save.
2803 * @parent: the parent #xmlNodePtr to save the description in.
2804 *
2805 * Saves the pad into an xml representation.
2806 *
2807 * Returns: the #xmlNodePtr representation of the pad.
2808 */
2809 static xmlNodePtr
2810 gst_pad_save_thyself (GstObject * object, xmlNodePtr parent)
2811 {
2812 GstPad *pad;
2813 GstPad *peer;
2815 g_return_val_if_fail (GST_IS_PAD (object), NULL);
2817 pad = GST_PAD (object);
2819 xmlNewChild (parent, NULL, (xmlChar *) "name",
2820 (xmlChar *) GST_PAD_NAME (pad));
2821 if (GST_PAD_PEER (pad) != NULL) {
2822 gchar *content;
2824 peer = GST_PAD_PEER (pad);
2825 /* first check to see if the peer's parent's parent is the same */
2826 /* we just save it off */
2827 content = g_strdup_printf ("%s.%s",
2828 GST_OBJECT_NAME (GST_PAD_PARENT (peer)), GST_PAD_NAME (peer));
2829 xmlNewChild (parent, NULL, (xmlChar *) "peer", (xmlChar *) content);
2830 g_free (content);
2831 } else
2832 xmlNewChild (parent, NULL, (xmlChar *) "peer", NULL);
2834 return parent;
2835 }
2837 #if 0
2838 /**
2839 * gst_ghost_pad_save_thyself:
2840 * @pad: a ghost #GstPad to save.
2841 * @parent: the parent #xmlNodePtr to save the description in.
2842 *
2843 * Saves the ghost pad into an xml representation.
2844 *
2845 * Returns: the #xmlNodePtr representation of the pad.
2846 */
2847 xmlNodePtr
2848 gst_ghost_pad_save_thyself (GstPad * pad, xmlNodePtr parent)
2849 {
2850 xmlNodePtr self;
2852 g_return_val_if_fail (GST_IS_GHOST_PAD (pad), NULL);
2854 self = xmlNewChild (parent, NULL, (xmlChar *) "ghostpad", NULL);
2855 xmlNewChild (self, NULL, (xmlChar *) "name", (xmlChar *) GST_PAD_NAME (pad));
2856 xmlNewChild (self, NULL, (xmlChar *) "parent",
2857 (xmlChar *) GST_OBJECT_NAME (GST_PAD_PARENT (pad)));
2859 /* FIXME FIXME FIXME! */
2861 return self;
2862 }
2863 #endif /* 0 */
2864 #endif /* GST_DISABLE_LOADSAVE */
2866 /*
2867 * should be called with pad lock held
2868 *
2869 * MT safe.
2870 */
2871 static void
2872 handle_pad_block (GstPad * pad)
2873 {
2874 GstPadBlockCallback callback;
2875 gpointer user_data;
2877 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
2878 "signal block taken on pad %s:%s", GST_DEBUG_PAD_NAME (pad));
2880 /* need to grab extra ref for the callbacks */
2881 gst_object_ref (pad);
2883 callback = pad->block_callback;
2884 if (callback) {
2885 user_data = pad->block_data;
2886 GST_UNLOCK (pad);
2887 callback (pad, TRUE, user_data);
2888 GST_LOCK (pad);
2889 } else {
2890 GST_PAD_BLOCK_SIGNAL (pad);
2891 }
2893 while (GST_PAD_IS_BLOCKED (pad))
2894 GST_PAD_BLOCK_WAIT (pad);
2896 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "got unblocked");
2898 callback = pad->block_callback;
2899 if (callback) {
2900 user_data = pad->block_data;
2901 GST_UNLOCK (pad);
2902 callback (pad, FALSE, user_data);
2903 GST_LOCK (pad);
2904 } else {
2905 GST_PAD_BLOCK_SIGNAL (pad);
2906 }
2908 gst_object_unref (pad);
2909 }
2911 /**********************************************************************
2912 * Data passing functions
2913 */
2915 static gboolean
2916 gst_pad_emit_have_data_signal (GstPad * pad, GstMiniObject * obj)
2917 {
2918 GValue ret = { 0 };
2919 GValue args[2] = { {0}, {0} };
2920 gboolean res;
2921 GQuark detail;
2923 /* init */
2924 g_value_init (&ret, G_TYPE_BOOLEAN);
2925 g_value_set_boolean (&ret, TRUE);
2926 g_value_init (&args[0], GST_TYPE_PAD);
2927 g_value_set_object (&args[0], pad);
2928 g_value_init (&args[1], GST_TYPE_MINI_OBJECT); // G_TYPE_POINTER);
2929 gst_value_set_mini_object (&args[1], obj);
2931 if (GST_IS_EVENT (obj))
2932 detail = event_quark;
2933 else
2934 detail = buffer_quark;
2936 /* actually emit */
2937 g_signal_emitv (args, gst_pad_signals[PAD_HAVE_DATA], detail, &ret);
2938 res = g_value_get_boolean (&ret);
2940 /* clean up */
2941 g_value_unset (&ret);
2942 g_value_unset (&args[0]);
2943 g_value_unset (&args[1]);
2945 return res;
2946 }
2948 /**
2949 * gst_pad_chain:
2950 * @pad: a sink #GstPad.
2951 * @buffer: the #GstBuffer to send.
2952 *
2953 * Chain a buffer to @pad.
2954 *
2955 * Returns: a #GstFlowReturn from the pad.
2956 *
2957 * MT safe.
2958 */
2959 GstFlowReturn
2960 gst_pad_chain (GstPad * pad, GstBuffer * buffer)
2961 {
2962 GstCaps *caps;
2963 gboolean caps_changed;
2964 GstPadChainFunction chainfunc;
2965 GstFlowReturn ret;
2966 gboolean emit_signal;
2968 g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
2969 g_return_val_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SINK,
2970 GST_FLOW_ERROR);
2971 g_return_val_if_fail (buffer != NULL, GST_FLOW_ERROR);
2972 g_return_val_if_fail (GST_IS_BUFFER (buffer), GST_FLOW_ERROR);
2974 GST_STREAM_LOCK (pad);
2976 GST_LOCK (pad);
2977 if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad)))
2978 goto flushing;
2980 caps = GST_BUFFER_CAPS (buffer);
2981 caps_changed = caps && caps != GST_PAD_CAPS (pad);
2983 emit_signal = GST_PAD_DO_BUFFER_SIGNALS (pad) > 0;
2984 GST_UNLOCK (pad);
2986 /* see if the signal should be emited, we emit before caps nego as
2987 * we might drop the buffer and do capsnego for nothing. */
2988 if (G_UNLIKELY (emit_signal)) {
2989 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (buffer)))
2990 goto dropping;
2991 }
2993 /* we got a new datatype on the pad, see if it can handle it */
2994 if (G_UNLIKELY (caps_changed)) {
2995 GST_DEBUG ("caps changed to %" GST_PTR_FORMAT, caps);
2996 if (G_UNLIKELY (!gst_pad_configure_sink (pad, caps)))
2997 goto not_negotiated;
2998 }
3000 /* NOTE: we read the chainfunc unlocked.
3001 * we cannot hold the lock for the pad so we might send
3002 * the data to the wrong function. This is not really a
3003 * problem since functions are assigned at creation time
3004 * and don't change that often... */
3005 if (G_UNLIKELY ((chainfunc = GST_PAD_CHAINFUNC (pad)) == NULL))
3006 goto no_function;
3008 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3009 "calling chainfunction &%s of pad %s:%s",
3010 GST_DEBUG_FUNCPTR_NAME (chainfunc), GST_DEBUG_PAD_NAME (pad));
3012 ret = chainfunc (pad, buffer);
3014 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3015 "called chainfunction &%s of pad %s:%s, returned %s",
3016 GST_DEBUG_FUNCPTR_NAME (chainfunc), GST_DEBUG_PAD_NAME (pad),
3017 gst_flow_get_name (ret));
3019 GST_STREAM_UNLOCK (pad);
3021 return ret;
3023 /* ERRORS */
3024 flushing:
3025 {
3026 gst_buffer_unref (buffer);
3027 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3028 "pushing, but pad was flushing");
3029 GST_UNLOCK (pad);
3030 GST_STREAM_UNLOCK (pad);
3031 return GST_FLOW_WRONG_STATE;
3032 }
3033 dropping:
3034 {
3035 gst_buffer_unref (buffer);
3036 GST_DEBUG_OBJECT (pad, "Dropping buffer due to FALSE probe return");
3037 GST_STREAM_UNLOCK (pad);
3038 return GST_FLOW_OK;
3039 }
3040 not_negotiated:
3041 {
3042 gst_buffer_unref (buffer);
3043 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3044 "pushing buffer but pad did not accept");
3045 GST_STREAM_UNLOCK (pad);
3046 return GST_FLOW_NOT_NEGOTIATED;
3047 }
3048 no_function:
3049 {
3050 gst_buffer_unref (buffer);
3051 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3052 "pushing, but not chainhandler");
3053 GST_ELEMENT_ERROR (GST_PAD_PARENT (pad), CORE, PAD, (NULL),
3054 ("push on pad %s:%s but it has no chainfunction",
3055 GST_DEBUG_PAD_NAME (pad)));
3056 GST_STREAM_UNLOCK (pad);
3057 return GST_FLOW_ERROR;
3058 }
3059 }
3061 /**
3062 * gst_pad_push:
3063 * @pad: a source #GstPad.
3064 * @buffer: the #GstBuffer to push.
3065 *
3066 * Pushes a buffer to the peer of @pad. @pad must be linked.
3067 *
3068 * Returns: a #GstFlowReturn from the peer pad.
3069 *
3070 * MT safe.
3071 */
3072 GstFlowReturn
3073 gst_pad_push (GstPad * pad, GstBuffer * buffer)
3074 {
3075 GstPad *peer;
3076 GstFlowReturn ret;
3077 gboolean emit_signal;
3079 g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
3080 g_return_val_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SRC, GST_FLOW_ERROR);
3081 g_return_val_if_fail (buffer != NULL, GST_FLOW_ERROR);
3082 g_return_val_if_fail (GST_IS_BUFFER (buffer), GST_FLOW_ERROR);
3084 GST_LOCK (pad);
3085 while (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad)))
3086 handle_pad_block (pad);
3088 if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
3089 goto not_linked;
3091 /* we emit signals on the pad areg, the peer will have a chance to
3092 * emit in the _chain() function */
3093 emit_signal = GST_PAD_DO_BUFFER_SIGNALS (pad) > 0;
3095 gst_object_ref (peer);
3096 GST_UNLOCK (pad);
3098 if (G_UNLIKELY (emit_signal)) {
3099 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (buffer)))
3100 goto dropping;
3101 }
3103 ret = gst_pad_chain (peer, buffer);
3105 gst_object_unref (peer);
3107 return ret;
3109 /* ERROR recovery here */
3110 not_linked:
3111 {
3112 gst_buffer_unref (buffer);
3113 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3114 "pushing, but it was not linked");
3115 GST_UNLOCK (pad);
3116 return GST_FLOW_NOT_LINKED;
3117 }
3118 dropping:
3119 {
3120 gst_buffer_unref (buffer);
3121 gst_object_unref (peer);
3122 GST_DEBUG ("Dropping buffer due to FALSE probe return");
3123 return GST_FLOW_OK;
3124 }
3125 }
3127 /**
3128 * gst_pad_check_pull_range:
3129 * @pad: a sink #GstPad.
3130 *
3131 * Checks if a #gst_pad_pull_range() can be performed on the peer
3132 * source pad. This function is used by plugins that want to check
3133 * if they can use random access on the peer source pad.
3134 *
3135 * The peer sourcepad can implement a custom #GstPadCheckGetRangeFunction
3136 * if it needs to perform some logic to determine if pull_range is
3137 * possible.
3138 *
3139 * Returns: a gboolean with the result.
3140 *
3141 * MT safe.
3142 */
3143 gboolean
3144 gst_pad_check_pull_range (GstPad * pad)
3145 {
3146 GstPad *peer;
3147 gboolean ret;
3148 GstPadCheckGetRangeFunction checkgetrangefunc;
3150 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
3152 GST_LOCK (pad);
3153 if (GST_PAD_DIRECTION (pad) != GST_PAD_SINK)
3154 goto wrong_direction;
3156 if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
3157 goto not_connected;
3159 gst_object_ref (peer);
3160 GST_UNLOCK (pad);
3162 /* see note in above function */
3163 if (G_LIKELY ((checkgetrangefunc = peer->checkgetrangefunc) == NULL)) {
3164 /* FIXME, kindoff ghetto */
3165 ret = GST_PAD_GETRANGEFUNC (peer) != NULL;
3166 } else {
3167 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3168 "calling checkgetrangefunc %s of peer pad %s:%s",
3169 GST_DEBUG_FUNCPTR_NAME (checkgetrangefunc), GST_DEBUG_PAD_NAME (peer));
3171 ret = checkgetrangefunc (peer);
3172 }
3174 gst_object_unref (peer);
3176 return ret;
3178 /* ERROR recovery here */
3179 wrong_direction:
3180 {
3181 GST_UNLOCK (pad);
3182 return FALSE;
3183 }
3184 not_connected:
3185 {
3186 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3187 "checking pull range, but it was not linked");
3188 GST_UNLOCK (pad);
3189 return FALSE;
3190 }
3191 }
3193 /**
3194 * gst_pad_get_range:
3195 * @pad: a src #GstPad.
3196 * @offset: The start offset of the buffer
3197 * @size: The length of the buffer
3198 * @buffer: a pointer to hold the #GstBuffer.
3199 *
3200 * Calls the getrange function of @pad.
3201 *
3202 * Returns: a #GstFlowReturn from the pad.
3203 *
3204 * MT safe.
3205 */
3206 GstFlowReturn
3207 gst_pad_get_range (GstPad * pad, guint64 offset, guint size,
3208 GstBuffer ** buffer)
3209 {
3210 GstFlowReturn ret;
3211 GstPadGetRangeFunction getrangefunc;
3212 gboolean emit_signal;
3214 g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
3215 g_return_val_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SRC, GST_FLOW_ERROR);
3216 g_return_val_if_fail (buffer != NULL, GST_FLOW_ERROR);
3218 GST_STREAM_LOCK (pad);
3220 GST_LOCK (pad);
3221 if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad)))
3222 goto flushing;
3224 emit_signal = GST_PAD_DO_BUFFER_SIGNALS (pad) > 0;
3225 GST_UNLOCK (pad);
3227 if (G_UNLIKELY ((getrangefunc = GST_PAD_GETRANGEFUNC (pad)) == NULL))
3228 goto no_function;
3230 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3231 "calling getrangefunc %s of peer pad %s:%s, offset %"
3232 G_GUINT64_FORMAT ", size %u",
3233 GST_DEBUG_FUNCPTR_NAME (getrangefunc), GST_DEBUG_PAD_NAME (pad),
3234 offset, size);
3236 ret = getrangefunc (pad, offset, size, buffer);
3238 /* can only fire the signal if we have a valid buffer */
3239 if (G_UNLIKELY (emit_signal) && (ret == GST_FLOW_OK)) {
3240 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (*buffer)))
3241 goto dropping;
3242 }
3244 GST_STREAM_UNLOCK (pad);
3246 return ret;
3248 /* ERRORS */
3249 flushing:
3250 {
3251 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3252 "pulling range, but pad was flushing");
3253 GST_UNLOCK (pad);
3254 GST_STREAM_UNLOCK (pad);
3255 return GST_FLOW_WRONG_STATE;
3256 }
3257 no_function:
3258 {
3259 GST_ELEMENT_ERROR (GST_PAD_PARENT (pad), CORE, PAD, (NULL),
3260 ("pullrange on pad %s:%s but it has no getrangefunction",
3261 GST_DEBUG_PAD_NAME (pad)));
3262 GST_STREAM_UNLOCK (pad);
3263 return GST_FLOW_ERROR;
3264 }
3265 dropping:
3266 {
3267 GST_DEBUG ("Dropping data after FALSE probe return");
3268 GST_STREAM_UNLOCK (pad);
3269 gst_buffer_unref (*buffer);
3270 *buffer = NULL;
3271 return GST_FLOW_UNEXPECTED;
3272 }
3273 }
3276 /**
3277 * gst_pad_pull_range:
3278 * @pad: a sink #GstPad.
3279 * @offset: The start offset of the buffer
3280 * @size: The length of the buffer
3281 * @buffer: a pointer to hold the #GstBuffer.
3282 *
3283 * Pulls a buffer from the peer pad. @pad must be a linked
3284 * sinkpad.
3285 *
3286 * Returns: a #GstFlowReturn from the peer pad.
3287 *
3288 * MT safe.
3289 */
3290 GstFlowReturn
3291 gst_pad_pull_range (GstPad * pad, guint64 offset, guint size,
3292 GstBuffer ** buffer)
3293 {
3294 GstPad *peer;
3295 GstFlowReturn ret;
3296 gboolean emit_signal;
3298 g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
3299 g_return_val_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SINK,
3300 GST_FLOW_ERROR);
3301 g_return_val_if_fail (buffer != NULL, GST_FLOW_ERROR);
3303 GST_LOCK (pad);
3305 while (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad)))
3306 handle_pad_block (pad);
3308 if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
3309 goto not_connected;
3311 /* signal emision for the pad, peer has chance to emit when
3312 * we call _get_range() */
3313 emit_signal = GST_PAD_DO_BUFFER_SIGNALS (pad) > 0;
3315 gst_object_ref (peer);
3316 GST_UNLOCK (pad);
3318 ret = gst_pad_get_range (peer, offset, size, buffer);
3320 gst_object_unref (peer);
3322 /* can only fire the signal if we have a valid buffer */
3323 if (G_UNLIKELY (emit_signal) && (ret == GST_FLOW_OK)) {
3324 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (*buffer)))
3325 goto dropping;
3326 }
3327 return ret;
3329 /* ERROR recovery here */
3330 not_connected:
3331 {
3332 GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
3333 "pulling range, but it was not linked");
3334 GST_UNLOCK (pad);
3335 return GST_FLOW_NOT_LINKED;
3336 }
3337 dropping:
3338 {
3339 GST_DEBUG ("Dropping data after FALSE probe return");
3340 gst_buffer_unref (*buffer);
3341 *buffer = NULL;
3342 return GST_FLOW_UNEXPECTED;
3343 }
3344 }
3346 /**
3347 * gst_pad_push_event:
3348 * @pad: a #GstPad to push the event to.
3349 * @event: the #GstEvent to send to the pad.
3350 *
3351 * Sends the event to the peer of the given pad. This function is
3352 * mainly used by elements to send events to their peer
3353 * elements.
3354 *
3355 * Returns: TRUE if the event was handled.
3356 *
3357 * MT safe.
3358 */
3359 gboolean
3360 gst_pad_push_event (GstPad * pad, GstEvent * event)
3361 {
3362 GstPad *peerpad;
3363 gboolean result;
3364 gboolean emit_signal;
3366 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
3367 g_return_val_if_fail (event != NULL, FALSE);
3369 GST_LOCK (pad);
3370 peerpad = GST_PAD_PEER (pad);
3371 if (peerpad == NULL)
3372 goto not_linked;
3374 emit_signal = GST_PAD_DO_EVENT_SIGNALS (pad) > 0;
3376 gst_object_ref (peerpad);
3377 GST_UNLOCK (pad);
3379 if (G_UNLIKELY (emit_signal)) {
3380 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (event)))
3381 goto dropping;
3382 }
3384 result = gst_pad_send_event (peerpad, event);
3386 gst_object_unref (peerpad);
3388 return result;
3390 /* ERROR handling */
3391 not_linked:
3392 {
3393 gst_event_unref (event);
3394 GST_UNLOCK (pad);
3395 return FALSE;
3396 }
3397 dropping:
3398 {
3399 GST_DEBUG ("Dropping event after FALSE probe return");
3400 gst_object_unref (peerpad);
3401 gst_event_unref (event);
3402 return FALSE;
3403 }
3404 }
3406 /**
3407 * gst_pad_send_event:
3408 * @pad: a #GstPad to send the event to.
3409 * @event: the #GstEvent to send to the pad.
3410 *
3411 * Sends the event to the pad. This function can be used
3412 * by applications to send events in the pipeline.
3413 *
3414 * Returns: TRUE if the event was handled.
3415 */
3416 gboolean
3417 gst_pad_send_event (GstPad * pad, GstEvent * event)
3418 {
3419 gboolean result = FALSE;
3420 GstPadEventFunction eventfunc;
3421 gboolean emit_signal;
3423 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
3424 g_return_val_if_fail (event != NULL, FALSE);
3426 GST_LOCK (pad);
3428 if (GST_PAD_IS_SINK (pad) && !GST_EVENT_IS_DOWNSTREAM (event))
3429 goto wrong_direction;
3430 if (GST_PAD_IS_SRC (pad) && !GST_EVENT_IS_UPSTREAM (event))
3431 goto wrong_direction;
3433 if (GST_EVENT_SRC (event) == NULL)
3434 GST_EVENT_SRC (event) = gst_object_ref (pad);
3436 switch (GST_EVENT_TYPE (event)) {
3437 case GST_EVENT_FLUSH_START:
3438 GST_CAT_DEBUG (GST_CAT_EVENT,
3439 "have event type %d (FLUSH_START) on pad %s:%s",
3440 GST_EVENT_TYPE (event), GST_DEBUG_PAD_NAME (pad));
3442 /* can't even accept a flush begin event when flushing */
3443 if (GST_PAD_IS_FLUSHING (pad))
3444 goto flushing;
3445 GST_PAD_SET_FLUSHING (pad);
3446 GST_CAT_DEBUG (GST_CAT_EVENT, "set flush flag");
3447 break;
3448 case GST_EVENT_FLUSH_STOP:
3449 GST_PAD_UNSET_FLUSHING (pad);
3450 GST_CAT_DEBUG (GST_CAT_EVENT, "cleared flush flag");
3451 break;
3452 default:
3453 GST_CAT_DEBUG (GST_CAT_EVENT, "have event type %d on pad %s:%s",
3454 GST_EVENT_TYPE (event), GST_DEBUG_PAD_NAME (pad));
3456 if (GST_PAD_IS_FLUSHING (pad))
3457 goto flushing;
3458 break;
3459 }
3461 if ((eventfunc = GST_PAD_EVENTFUNC (pad)) == NULL)
3462 goto no_function;
3464 emit_signal = GST_PAD_DO_EVENT_SIGNALS (pad) > 0;
3466 gst_object_ref (pad);
3467 GST_UNLOCK (pad);
3469 if (G_UNLIKELY (emit_signal)) {
3470 if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (event)))
3471 goto dropping;
3472 }
3474 result = eventfunc (GST_PAD_CAST (pad), event);
3476 gst_object_unref (pad);
3478 return result;
3480 /* ERROR handling */
3481 wrong_direction:
3482 {
3483 g_warning ("pad %s:%s sending event in wrong direction",
3484 GST_DEBUG_PAD_NAME (pad));
3485 GST_UNLOCK (pad);
3486 gst_event_unref (event);
3487 return FALSE;
3488 }
3489 no_function:
3490 {
3491 g_warning ("pad %s:%s has no event handler, file a bug.",
3492 GST_DEBUG_PAD_NAME (pad));
3493 GST_UNLOCK (pad);
3494 gst_event_unref (event);
3495 return FALSE;
3496 }
3497 flushing:
3498 {
3499 GST_UNLOCK (pad);
3500 GST_CAT_DEBUG (GST_CAT_EVENT, "Received event on flushing pad. Discarding");
3501 gst_event_unref (event);
3502 return FALSE;
3503 }
3504 dropping:
3505 {
3506 GST_DEBUG ("Dropping event after FALSE probe return");
3507 gst_object_unref (pad);
3508 gst_event_unref (event);
3509 return FALSE;
3510 }
3511 }
3513 /**
3514 * gst_pad_set_element_private:
3515 * @pad: the #GstPad to set the private data of.
3516 * @priv: The private data to attach to the pad.
3517 *
3518 * Set the given private data gpointer on the pad.
3519 * This function can only be used by the element that owns the pad.
3520 */
3521 void
3522 gst_pad_set_element_private (GstPad * pad, gpointer priv)
3523 {
3524 pad->element_private = priv;
3525 }
3527 /**
3528 * gst_pad_get_element_private:
3529 * @pad: the #GstPad to get the private data of.
3530 *
3531 * Gets the private data of a pad.
3532 *
3533 * Returns: a #gpointer to the private data.
3534 */
3535 gpointer
3536 gst_pad_get_element_private (GstPad * pad)
3537 {
3538 return pad->element_private;
3539 }
3541 /**
3542 * gst_pad_start_task:
3543 * @pad: the #GstPad to start the task of
3544 * @func: the task function to call
3545 * @data: data passed to the task function
3546 *
3547 * Starts a task that repeadedly calls @func with @data. This function
3548 * is nostly used in the pad activation function to start the
3549 * dataflow. This function will automatically acauire the STREAM_LOCK of
3550 * the pad before calling @func.
3551 *
3552 * Returns: a TRUE if the task could be started.
3553 */
3554 gboolean
3555 gst_pad_start_task (GstPad * pad, GstTaskFunction func, gpointer data)
3556 {
3557 GstTask *task;
3559 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
3560 g_return_val_if_fail (func != NULL, FALSE);
3562 GST_LOCK (pad);
3563 task = GST_PAD_TASK (pad);
3564 if (task == NULL) {
3565 task = gst_task_create (func, data);
3566 gst_task_set_lock (task, GST_STREAM_GET_LOCK (pad));
3567 GST_PAD_TASK (pad) = task;
3568 }
3569 gst_task_start (task);
3570 GST_UNLOCK (pad);
3572 return TRUE;
3573 }
3575 /**
3576 * gst_pad_pause_task:
3577 * @pad: the #GstPad to pause the task of
3578 *
3579 * Pause the task of @pad. This function will also make sure that the
3580 * function executed by the task will effectively stop.
3581 *
3582 * Returns: a TRUE if the task could be paused or FALSE when the pad
3583 * has no task.
3584 */
3585 gboolean
3586 gst_pad_pause_task (GstPad * pad)
3587 {
3588 GstTask *task;
3590 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
3592 GST_LOCK (pad);
3593 task = GST_PAD_TASK (pad);
3594 if (task == NULL)
3595 goto no_task;
3596 gst_task_pause (task);
3597 GST_UNLOCK (pad);
3599 GST_STREAM_LOCK (pad);
3600 GST_STREAM_UNLOCK (pad);
3602 return TRUE;
3604 no_task:
3605 {
3606 GST_UNLOCK (pad);
3607 return TRUE;
3608 }
3609 }
3611 /**
3612 * gst_pad_stop_task:
3613 * @pad: the #GstPad to stop the task of
3614 *
3615 * Stop the task of @pad. This function will also make sure that the
3616 * function executed by the task will effectively stop if not called
3617 * from the GstTaskFunction.
3618 *
3619 * This function will deadlock if called from the GstTaskFunction of
3620 * the task. Use #gst_task_pause() instead.
3621 *
3622 * Returns: a TRUE if the task could be stopped or FALSE when the pad
3623 * has no task.
3624 */
3625 gboolean
3626 gst_pad_stop_task (GstPad * pad)
3627 {
3628 GstTask *task;
3630 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
3632 GST_LOCK (pad);
3633 task = GST_PAD_TASK (pad);
3634 if (task == NULL)
3635 goto no_task;
3636 GST_PAD_TASK (pad) = NULL;
3637 gst_task_stop (task);
3638 GST_UNLOCK (pad);
3640 GST_STREAM_LOCK (pad);
3641 GST_STREAM_UNLOCK (pad);
3643 gst_task_join (task);
3645 gst_object_unref (task);
3647 return TRUE;
3649 no_task:
3650 {
3651 GST_UNLOCK (pad);
3652 return TRUE;
3653 }
3654 }