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1 /* GStreamer
2  * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
3  *                    2000 Wim Taymans <wim.taymans@chello.be>
4  *
5  * gstpad.h: Header for GstPad object
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., 51 Franklin St, Fifth Floor,
20  * Boston, MA 02110-1301, USA.
21  */
22 
23 
24 #ifndef __GST_PAD_H__
25 #define __GST_PAD_H__
26 
27 #include <gst/gstconfig.h>
28 
29 typedef struct _GstPad GstPad;
30 typedef struct _GstPadPrivate GstPadPrivate;
31 typedef struct _GstPadClass GstPadClass;
32 typedef struct _GstPadProbeInfo GstPadProbeInfo;
33 
34 /**
35  * GstPadDirection:
36  * @GST_PAD_UNKNOWN: direction is unknown.
37  * @GST_PAD_SRC: the pad is a source pad.
38  * @GST_PAD_SINK: the pad is a sink pad.
39  *
40  * The direction of a pad.
41  */
42 typedef enum {
43   GST_PAD_UNKNOWN,
44   GST_PAD_SRC,
45   GST_PAD_SINK
46 } GstPadDirection;
47 
48 /**
49  * GstPadMode:
50  * @GST_PAD_MODE_NONE: Pad will not handle dataflow
51  * @GST_PAD_MODE_PUSH: Pad handles dataflow in downstream push mode
52  * @GST_PAD_MODE_PULL: Pad handles dataflow in upstream pull mode
53  *
54  * The status of a GstPad. After activating a pad, which usually happens when the
55  * parent element goes from READY to PAUSED, the GstPadMode defines if the
56  * pad operates in push or pull mode.
57  */
58 typedef enum {
59   GST_PAD_MODE_NONE,
60   GST_PAD_MODE_PUSH,
61   GST_PAD_MODE_PULL
62 } GstPadMode;
63 
64 #include <glib.h>
65 
66 GST_API
67 const gchar   * gst_pad_mode_get_name (GstPadMode mode);
68 
69 #include <gst/gstobject.h>
70 #include <gst/gstbuffer.h>
71 #include <gst/gstbufferlist.h>
72 #include <gst/gstcaps.h>
73 #include <gst/gstpadtemplate.h>
74 #include <gst/gstevent.h>
75 #include <gst/gstquery.h>
76 #include <gst/gsttask.h>
77 
78 G_BEGIN_DECLS
79 
80 /*
81  * Pad base class
82  */
83 #define GST_TYPE_PAD			(gst_pad_get_type ())
84 #define GST_IS_PAD(obj)			(G_TYPE_CHECK_INSTANCE_TYPE ((obj), GST_TYPE_PAD))
85 #define GST_IS_PAD_CLASS(klass)		(G_TYPE_CHECK_CLASS_TYPE ((klass), GST_TYPE_PAD))
86 #define GST_PAD(obj)			(G_TYPE_CHECK_INSTANCE_CAST ((obj), GST_TYPE_PAD, GstPad))
87 #define GST_PAD_CLASS(klass)		(G_TYPE_CHECK_CLASS_CAST ((klass), GST_TYPE_PAD, GstPadClass))
88 #define GST_PAD_CAST(obj)		((GstPad*)(obj))
89 
90 
91 
92 /**
93  * GstPadLinkReturn:
94  * @GST_PAD_LINK_OK		: link succeeded
95  * @GST_PAD_LINK_WRONG_HIERARCHY: pads have no common grandparent
96  * @GST_PAD_LINK_WAS_LINKED	: pad was already linked
97  * @GST_PAD_LINK_WRONG_DIRECTION: pads have wrong direction
98  * @GST_PAD_LINK_NOFORMAT	: pads do not have common format
99  * @GST_PAD_LINK_NOSCHED	: pads cannot cooperate in scheduling
100  * @GST_PAD_LINK_REFUSED	: refused for some reason
101  *
102  * Result values from gst_pad_link and friends.
103  */
104 typedef enum {
105   GST_PAD_LINK_OK               =  0,
106   GST_PAD_LINK_WRONG_HIERARCHY  = -1,
107   GST_PAD_LINK_WAS_LINKED       = -2,
108   GST_PAD_LINK_WRONG_DIRECTION  = -3,
109   GST_PAD_LINK_NOFORMAT         = -4,
110   GST_PAD_LINK_NOSCHED          = -5,
111   GST_PAD_LINK_REFUSED          = -6
112 } GstPadLinkReturn;
113 
114 /**
115  * GST_PAD_LINK_FAILED:
116  * @ret: the #GstPadLinkReturn value
117  *
118  * Macro to test if the given #GstPadLinkReturn value indicates a failed
119  * link step.
120  */
121 #define GST_PAD_LINK_FAILED(ret) ((ret) < GST_PAD_LINK_OK)
122 
123 /**
124  * GST_PAD_LINK_SUCCESSFUL:
125  * @ret: the #GstPadLinkReturn value
126  *
127  * Macro to test if the given #GstPadLinkReturn value indicates a successful
128  * link step.
129  */
130 #define GST_PAD_LINK_SUCCESSFUL(ret) ((ret) >= GST_PAD_LINK_OK)
131 
132 /**
133  * GstFlowReturn:
134  * @GST_FLOW_OK:		 Data passing was ok.
135  * @GST_FLOW_NOT_LINKED:	 Pad is not linked.
136  * @GST_FLOW_FLUSHING:	         Pad is flushing.
137  * @GST_FLOW_EOS:                Pad is EOS.
138  * @GST_FLOW_NOT_NEGOTIATED:	 Pad is not negotiated.
139  * @GST_FLOW_ERROR:		 Some (fatal) error occurred. Element generating
140  *                               this error should post an error message using
141  *                               GST_ELEMENT_ERROR() with more details.
142  * @GST_FLOW_NOT_SUPPORTED:	 This operation is not supported.
143  * @GST_FLOW_CUSTOM_SUCCESS:	 Elements can use values starting from
144  *                               this (and higher) to define custom success
145  *                               codes.
146  * @GST_FLOW_CUSTOM_SUCCESS_1:	 Pre-defined custom success code (define your
147  *                               custom success code to this to avoid compiler
148  *                               warnings).
149  * @GST_FLOW_CUSTOM_SUCCESS_2:	 Pre-defined custom success code.
150  * @GST_FLOW_CUSTOM_ERROR:	 Elements can use values starting from
151  *                               this (and lower) to define custom error codes.
152  * @GST_FLOW_CUSTOM_ERROR_1:	 Pre-defined custom error code (define your
153  *                               custom error code to this to avoid compiler
154  *                               warnings).
155  * @GST_FLOW_CUSTOM_ERROR_2:	 Pre-defined custom error code.
156  *
157  * The result of passing data to a pad.
158  *
159  * Note that the custom return values should not be exposed outside of the
160  * element scope.
161  */
162 typedef enum {
163   /* custom success starts here */
164   GST_FLOW_CUSTOM_SUCCESS_2 = 102,
165   GST_FLOW_CUSTOM_SUCCESS_1 = 101,
166   GST_FLOW_CUSTOM_SUCCESS = 100,
167 
168   /* core predefined */
169   GST_FLOW_OK		  =  0,
170   /* expected failures */
171   GST_FLOW_NOT_LINKED     = -1,
172   GST_FLOW_FLUSHING       = -2,
173   /* error cases */
174   GST_FLOW_EOS            = -3,
175   GST_FLOW_NOT_NEGOTIATED = -4,
176   GST_FLOW_ERROR	  = -5,
177   GST_FLOW_NOT_SUPPORTED  = -6,
178 #ifdef OHOS_EXT_FUNC
179   // ohos.ext.func.0033
180   GST_FLOW_RECONNECTION_TIMEOUT = -7,
181 #endif
182 
183   /* custom error starts here */
184   GST_FLOW_CUSTOM_ERROR   = -100,
185   GST_FLOW_CUSTOM_ERROR_1 = -101,
186   GST_FLOW_CUSTOM_ERROR_2 = -102
187 } GstFlowReturn;
188 
189 GST_API
190 const gchar *         gst_flow_get_name (GstFlowReturn ret);
191 
192 GST_API
193 GQuark                gst_flow_to_quark (GstFlowReturn ret);
194 
195 GST_API
196 const gchar *         gst_pad_link_get_name (GstPadLinkReturn ret);
197 
198 /**
199  * GstPadLinkCheck:
200  * @GST_PAD_LINK_CHECK_NOTHING: Don't check hierarchy or caps compatibility.
201  * @GST_PAD_LINK_CHECK_HIERARCHY: Check the pads have same parents/grandparents.
202  *   Could be omitted if it is already known that the two elements that own the
203  *   pads are in the same bin.
204  * @GST_PAD_LINK_CHECK_TEMPLATE_CAPS: Check if the pads are compatible by using
205  *   their template caps. This is much faster than @GST_PAD_LINK_CHECK_CAPS, but
206  *   would be unsafe e.g. if one pad has %GST_CAPS_ANY.
207  * @GST_PAD_LINK_CHECK_CAPS: Check if the pads are compatible by comparing the
208  *   caps returned by gst_pad_query_caps().
209  * @GST_PAD_LINK_CHECK_NO_RECONFIGURE: Disables pushing a reconfigure event when pads are
210  *   linked.
211  * @GST_PAD_LINK_CHECK_DEFAULT: The default checks done when linking
212  *   pads (i.e. the ones used by gst_pad_link()).
213  *
214  * The amount of checking to be done when linking pads. @GST_PAD_LINK_CHECK_CAPS
215  * and @GST_PAD_LINK_CHECK_TEMPLATE_CAPS are mutually exclusive. If both are
216  * specified, expensive but safe @GST_PAD_LINK_CHECK_CAPS are performed.
217  *
218  * > Only disable some of the checks if you are 100% certain you know the link
219  * > will not fail because of hierarchy/caps compatibility failures. If uncertain,
220  * > use the default checks (%GST_PAD_LINK_CHECK_DEFAULT) or the regular methods
221  * > for linking the pads.
222  */
223 
224 typedef enum {
225   GST_PAD_LINK_CHECK_NOTHING       = 0,
226   GST_PAD_LINK_CHECK_HIERARCHY     = 1 << 0,
227   GST_PAD_LINK_CHECK_TEMPLATE_CAPS = 1 << 1,
228   GST_PAD_LINK_CHECK_CAPS          = 1 << 2,
229 
230 
231   /* Not really checks, more like flags
232    * Added here to avoid creating a new gst_pad_link_variant */
233   GST_PAD_LINK_CHECK_NO_RECONFIGURE = 1 << 3,
234 
235   GST_PAD_LINK_CHECK_DEFAULT       = GST_PAD_LINK_CHECK_HIERARCHY | GST_PAD_LINK_CHECK_CAPS
236 } GstPadLinkCheck;
237 
238 /* pad states */
239 /**
240  * GstPadActivateFunction:
241  * @pad: a #GstPad
242  * @parent: the parent of @pad
243  *
244  * This function is called when the pad is activated during the element
245  * READY to PAUSED state change. By default this function will call the
246  * activate function that puts the pad in push mode but elements can
247  * override this function to activate the pad in pull mode if they wish.
248  *
249  * Returns: %TRUE if the pad could be activated.
250  */
251 typedef gboolean		(*GstPadActivateFunction)	(GstPad *pad, GstObject *parent);
252 /**
253  * GstPadActivateModeFunction:
254  * @pad: a #GstPad
255  * @parent: the parent of @pad
256  * @mode: the requested activation mode of @pad
257  * @active: activate or deactivate the pad.
258  *
259  * The prototype of the push and pull activate functions.
260  *
261  * Returns: %TRUE if the pad could be activated or deactivated.
262  */
263 typedef gboolean		(*GstPadActivateModeFunction)	(GstPad *pad, GstObject *parent,
264                                                                  GstPadMode mode, gboolean active);
265 
266 
267 /* data passing */
268 /**
269  * GstPadChainFunction:
270  * @pad: the sink #GstPad that performed the chain.
271  * @parent: (allow-none): the parent of @pad. If the #GST_PAD_FLAG_NEED_PARENT
272  *          flag is set, @parent is guaranteed to be not-%NULL and remain valid
273  *          during the execution of this function.
274  * @buffer: (transfer full): the #GstBuffer that is chained, not %NULL.
275  *
276  * A function that will be called on sinkpads when chaining buffers.
277  * The function typically processes the data contained in the buffer and
278  * either consumes the data or passes it on to the internally linked pad(s).
279  *
280  * The implementer of this function receives a refcount to @buffer and should
281  * gst_buffer_unref() when the buffer is no longer needed.
282  *
283  * When a chain function detects an error in the data stream, it must post an
284  * error on the bus and return an appropriate #GstFlowReturn value.
285  *
286  * Returns: #GST_FLOW_OK for success
287  */
288 typedef GstFlowReturn		(*GstPadChainFunction)		(GstPad *pad, GstObject *parent,
289                                                                  GstBuffer *buffer);
290 
291 /**
292  * GstPadChainListFunction:
293  * @pad: the sink #GstPad that performed the chain.
294  * @parent: (allow-none): the parent of @pad. If the #GST_PAD_FLAG_NEED_PARENT
295  *          flag is set, @parent is guaranteed to be not-%NULL and remain valid
296  *          during the execution of this function.
297  * @list: (transfer full): the #GstBufferList that is chained, not %NULL.
298  *
299  * A function that will be called on sinkpads when chaining buffer lists.
300  * The function typically processes the data contained in the buffer list and
301  * either consumes the data or passes it on to the internally linked pad(s).
302  *
303  * The implementer of this function receives a refcount to @list and
304  * should gst_buffer_list_unref() when the list is no longer needed.
305  *
306  * When a chainlist function detects an error in the data stream, it must
307  * post an error on the bus and return an appropriate #GstFlowReturn value.
308  *
309  * Returns: #GST_FLOW_OK for success
310  */
311 typedef GstFlowReturn		(*GstPadChainListFunction)	(GstPad *pad, GstObject *parent,
312                                                                  GstBufferList *list);
313 
314 /**
315  * GstPadGetRangeFunction:
316  * @pad: the src #GstPad to perform the getrange on.
317  * @parent: (allow-none): the parent of @pad. If the #GST_PAD_FLAG_NEED_PARENT
318  *          flag is set, @parent is guaranteed to be not-%NULL and remain valid
319  *          during the execution of this function.
320  * @offset: the offset of the range
321  * @length: the length of the range
322  * @buffer: a memory location to hold the result buffer, cannot be %NULL.
323  *
324  * This function will be called on source pads when a peer element
325  * request a buffer at the specified @offset and @length. If this function
326  * returns #GST_FLOW_OK, the result buffer will be stored in @buffer. The
327  * contents of @buffer is invalid for any other return value.
328  *
329  * This function is installed on a source pad with
330  * gst_pad_set_getrange_function() and can only be called on source pads after
331  * they are successfully activated with gst_pad_activate_mode() with the
332  * #GST_PAD_MODE_PULL.
333  *
334  * @offset and @length are always given in byte units. @offset must normally be a value
335  * between 0 and the length in bytes of the data available on @pad. The
336  * length (duration in bytes) can be retrieved with a #GST_QUERY_DURATION or with a
337  * #GST_QUERY_SEEKING.
338  *
339  * Any @offset larger or equal than the length will make the function return
340  * #GST_FLOW_EOS, which corresponds to EOS. In this case @buffer does not
341  * contain a valid buffer.
342  *
343  * The buffer size of @buffer will only be smaller than @length when @offset is
344  * near the end of the stream. In all other cases, the size of @buffer must be
345  * exactly the requested size.
346  *
347  * It is allowed to call this function with a 0 @length and valid @offset, in
348  * which case @buffer will contain a 0-sized buffer and the function returns
349  * #GST_FLOW_OK.
350  *
351  * When this function is called with a -1 @offset, the sequentially next buffer
352  * of length @length in the stream is returned.
353  *
354  * When this function is called with a -1 @length, a buffer with a default
355  * optimal length is returned in @buffer. The length might depend on the value
356  * of @offset.
357  *
358  * Returns: #GST_FLOW_OK for success and a valid buffer in @buffer. Any other
359  * return value leaves @buffer undefined.
360  */
361 typedef GstFlowReturn		(*GstPadGetRangeFunction)	(GstPad *pad, GstObject *parent,
362                                                                  guint64 offset, guint length,
363                                                                  GstBuffer **buffer);
364 
365 /**
366  * GstPadEventFunction:
367  * @pad: the #GstPad to handle the event.
368  * @parent: (allow-none): the parent of @pad. If the #GST_PAD_FLAG_NEED_PARENT
369  *          flag is set, @parent is guaranteed to be not-%NULL and remain valid
370  *          during the execution of this function.
371  * @event: (transfer full): the #GstEvent to handle.
372  *
373  * Function signature to handle an event for the pad.
374  *
375  * Returns: %TRUE if the pad could handle the event.
376  */
377 typedef gboolean		(*GstPadEventFunction)		(GstPad *pad, GstObject *parent,
378                                                                  GstEvent *event);
379 
380 /**
381  * GstPadEventFullFunction:
382  * @pad: the #GstPad to handle the event.
383  * @parent: (allow-none): the parent of @pad. If the #GST_PAD_FLAG_NEED_PARENT
384  *          flag is set, @parent is guaranteed to be not-%NULL and remain valid
385  *          during the execution of this function.
386  * @event: (transfer full): the #GstEvent to handle.
387  *
388  * Function signature to handle an event for the pad.
389  *
390  * This variant is for specific elements that will take into account the
391  * last downstream flow return (from a pad push), in which case they can
392  * return it.
393  *
394  * Returns: %GST_FLOW_OK if the event was handled properly, or any other
395  * #GstFlowReturn dependent on downstream state.
396  *
397  * Since: 1.8
398  */
399 typedef GstFlowReturn		(*GstPadEventFullFunction)	(GstPad *pad, GstObject *parent,
400                                                                  GstEvent *event);
401 
402 
403 /* internal links */
404 /**
405  * GstPadIterIntLinkFunction:
406  * @pad: The #GstPad to query.
407  * @parent: (allow-none): the parent of @pad. If the #GST_PAD_FLAG_NEED_PARENT
408  *          flag is set, @parent is guaranteed to be not-%NULL and remain valid
409  *          during the execution of this function.
410  *
411  * The signature of the internal pad link iterator function.
412  *
413  * Returns: a new #GstIterator that will iterate over all pads that are
414  * linked to the given pad on the inside of the parent element.
415  *
416  * the caller must call gst_iterator_free() after usage.
417  */
418 typedef GstIterator*           (*GstPadIterIntLinkFunction)    (GstPad *pad, GstObject *parent);
419 
420 /* generic query function */
421 /**
422  * GstPadQueryFunction:
423  * @pad: the #GstPad to query.
424  * @parent: (allow-none): the parent of @pad. If the #GST_PAD_FLAG_NEED_PARENT
425  *          flag is set, @parent is guaranteed to be not-%NULL and remain valid
426  *          during the execution of this function.
427  * @query: the #GstQuery object to execute
428  *
429  * The signature of the query function.
430  *
431  * Returns: %TRUE if the query could be performed.
432  */
433 typedef gboolean		(*GstPadQueryFunction)		(GstPad *pad, GstObject *parent,
434                                                                  GstQuery *query);
435 
436 
437 /* linking */
438 /**
439  * GstPadLinkFunction:
440  * @pad: the #GstPad that is linked.
441  * @parent: (allow-none): the parent of @pad. If the #GST_PAD_FLAG_NEED_PARENT
442  *          flag is set, @parent is guaranteed to be not-%NULL and remain valid
443  *          during the execution of this function.
444  * @peer: the peer #GstPad of the link
445  *
446  * Function signature to handle a new link on the pad.
447  *
448  * Returns: the result of the link with the specified peer.
449  */
450 typedef GstPadLinkReturn	(*GstPadLinkFunction)		(GstPad *pad, GstObject *parent, GstPad *peer);
451 /**
452  * GstPadUnlinkFunction:
453  * @pad: the #GstPad that is linked.
454  * @parent: (allow-none): the parent of @pad. If the #GST_PAD_FLAG_NEED_PARENT
455  *          flag is set, @parent is guaranteed to be not-%NULL and remain valid
456  *          during the execution of this function.
457  *
458  * Function signature to handle a unlinking the pad prom its peer.
459  *
460  * The pad's lock is already held when the unlink function is called, so most
461  * pad functions cannot be called from within the callback.
462  */
463 typedef void			(*GstPadUnlinkFunction)		(GstPad *pad, GstObject *parent);
464 
465 
466 /* misc */
467 /**
468  * GstPadForwardFunction:
469  * @pad: the #GstPad that is forwarded.
470  * @user_data: the gpointer to optional user data.
471  *
472  * A forward function is called for all internally linked pads, see
473  * gst_pad_forward().
474  *
475  * Returns: %TRUE if the dispatching procedure has to be stopped.
476  */
477 typedef gboolean		(*GstPadForwardFunction)	(GstPad *pad, gpointer user_data);
478 
479 /**
480  * GstPadProbeType:
481  * @GST_PAD_PROBE_TYPE_INVALID: invalid probe type
482  * @GST_PAD_PROBE_TYPE_IDLE: probe idle pads and block while the callback is called
483  * @GST_PAD_PROBE_TYPE_BLOCK: probe and block pads
484  * @GST_PAD_PROBE_TYPE_BUFFER: probe buffers
485  * @GST_PAD_PROBE_TYPE_BUFFER_LIST: probe buffer lists
486  * @GST_PAD_PROBE_TYPE_EVENT_DOWNSTREAM: probe downstream events
487  * @GST_PAD_PROBE_TYPE_EVENT_UPSTREAM: probe upstream events
488  * @GST_PAD_PROBE_TYPE_EVENT_FLUSH: probe flush events. This probe has to be
489  *     explicitly enabled and is not included in the
490  *     @@GST_PAD_PROBE_TYPE_EVENT_DOWNSTREAM or
491  *     @@GST_PAD_PROBE_TYPE_EVENT_UPSTREAM probe types.
492  * @GST_PAD_PROBE_TYPE_QUERY_DOWNSTREAM: probe downstream queries
493  * @GST_PAD_PROBE_TYPE_QUERY_UPSTREAM: probe upstream queries
494  * @GST_PAD_PROBE_TYPE_PUSH: probe push
495  * @GST_PAD_PROBE_TYPE_PULL: probe pull
496  * @GST_PAD_PROBE_TYPE_BLOCKING: probe and block at the next opportunity, at data flow or when idle
497  * @GST_PAD_PROBE_TYPE_DATA_DOWNSTREAM: probe downstream data (buffers, buffer lists, and events)
498  * @GST_PAD_PROBE_TYPE_DATA_UPSTREAM: probe upstream data (events)
499  * @GST_PAD_PROBE_TYPE_DATA_BOTH: probe upstream and downstream data (buffers, buffer lists, and events)
500  * @GST_PAD_PROBE_TYPE_BLOCK_DOWNSTREAM: probe and block downstream data (buffers, buffer lists, and events)
501  * @GST_PAD_PROBE_TYPE_BLOCK_UPSTREAM: probe and block upstream data (events)
502  * @GST_PAD_PROBE_TYPE_EVENT_BOTH: probe upstream and downstream events
503  * @GST_PAD_PROBE_TYPE_QUERY_BOTH: probe upstream and downstream queries
504  * @GST_PAD_PROBE_TYPE_ALL_BOTH: probe upstream events and queries and downstream buffers, buffer lists, events and queries
505  * @GST_PAD_PROBE_TYPE_SCHEDULING: probe push and pull
506  *
507  * The different probing types that can occur. When either one of
508  * @GST_PAD_PROBE_TYPE_IDLE or @GST_PAD_PROBE_TYPE_BLOCK is used, the probe will be a
509  * blocking probe.
510  */
511 typedef enum
512 {
513   GST_PAD_PROBE_TYPE_INVALID          = 0,
514   /* flags to control blocking */
515   GST_PAD_PROBE_TYPE_IDLE             = (1 << 0),
516   GST_PAD_PROBE_TYPE_BLOCK            = (1 << 1),
517   /* flags to select datatypes */
518   GST_PAD_PROBE_TYPE_BUFFER           = (1 << 4),
519   GST_PAD_PROBE_TYPE_BUFFER_LIST      = (1 << 5),
520   GST_PAD_PROBE_TYPE_EVENT_DOWNSTREAM = (1 << 6),
521   GST_PAD_PROBE_TYPE_EVENT_UPSTREAM   = (1 << 7),
522   GST_PAD_PROBE_TYPE_EVENT_FLUSH      = (1 << 8),
523   GST_PAD_PROBE_TYPE_QUERY_DOWNSTREAM = (1 << 9),
524   GST_PAD_PROBE_TYPE_QUERY_UPSTREAM   = (1 << 10),
525   /* flags to select scheduling mode */
526   GST_PAD_PROBE_TYPE_PUSH             = (1 << 12),
527   GST_PAD_PROBE_TYPE_PULL             = (1 << 13),
528 
529   /* flag combinations */
530   GST_PAD_PROBE_TYPE_BLOCKING         = GST_PAD_PROBE_TYPE_IDLE | GST_PAD_PROBE_TYPE_BLOCK,
531   GST_PAD_PROBE_TYPE_DATA_DOWNSTREAM  = GST_PAD_PROBE_TYPE_BUFFER | GST_PAD_PROBE_TYPE_BUFFER_LIST | GST_PAD_PROBE_TYPE_EVENT_DOWNSTREAM,
532   GST_PAD_PROBE_TYPE_DATA_UPSTREAM    = GST_PAD_PROBE_TYPE_EVENT_UPSTREAM,
533   GST_PAD_PROBE_TYPE_DATA_BOTH        = GST_PAD_PROBE_TYPE_DATA_DOWNSTREAM | GST_PAD_PROBE_TYPE_DATA_UPSTREAM,
534   GST_PAD_PROBE_TYPE_BLOCK_DOWNSTREAM = GST_PAD_PROBE_TYPE_BLOCK | GST_PAD_PROBE_TYPE_DATA_DOWNSTREAM,
535   GST_PAD_PROBE_TYPE_BLOCK_UPSTREAM   = GST_PAD_PROBE_TYPE_BLOCK | GST_PAD_PROBE_TYPE_DATA_UPSTREAM,
536   GST_PAD_PROBE_TYPE_EVENT_BOTH       = GST_PAD_PROBE_TYPE_EVENT_DOWNSTREAM | GST_PAD_PROBE_TYPE_EVENT_UPSTREAM,
537   GST_PAD_PROBE_TYPE_QUERY_BOTH       = GST_PAD_PROBE_TYPE_QUERY_DOWNSTREAM | GST_PAD_PROBE_TYPE_QUERY_UPSTREAM,
538   GST_PAD_PROBE_TYPE_ALL_BOTH         = GST_PAD_PROBE_TYPE_DATA_BOTH | GST_PAD_PROBE_TYPE_QUERY_BOTH,
539   GST_PAD_PROBE_TYPE_SCHEDULING       = GST_PAD_PROBE_TYPE_PUSH | GST_PAD_PROBE_TYPE_PULL
540 } GstPadProbeType;
541 
542 
543 /**
544  * GstPadProbeReturn:
545  * @GST_PAD_PROBE_OK: normal probe return value. This leaves the probe in
546  *        place, and defers decisions about dropping or passing data to other
547  *        probes, if any. If there are no other probes, the default behaviour
548  *        for the probe type applies ('block' for blocking probes,
549  *        and 'pass' for non-blocking probes).
550  * @GST_PAD_PROBE_DROP: drop data in data probes. For push mode this means that
551  *        the data item is not sent downstream. For pull mode, it means that
552  *        the data item is not passed upstream. In both cases, no other probes
553  *        are called for this item and %GST_FLOW_OK or %TRUE is returned to the
554  *        caller.
555  * @GST_PAD_PROBE_REMOVE: remove this probe, passing the data. For blocking probes
556  *        this will cause data flow to unblock, unless there are also other
557  *        blocking probes installed.
558  * @GST_PAD_PROBE_PASS: pass the data item in the block probe and block on the
559  *        next item. Note, that if there are multiple pad probes installed and
560  *        any probe returns PASS, the data will be passed.
561  * @GST_PAD_PROBE_HANDLED: Data has been handled in the probe and will not be
562  *        forwarded further. For events and buffers this is the same behaviour as
563  *        %GST_PAD_PROBE_DROP (except that in this case you need to unref the buffer
564  *        or event yourself). For queries it will also return %TRUE to the caller.
565  *        The probe can also modify the #GstFlowReturn value by using the
566  *        #GST_PAD_PROBE_INFO_FLOW_RETURN() accessor.
567  *        Note that the resulting query must contain valid entries.
568  *        Since: 1.6
569  *
570  * Different return values for the #GstPadProbeCallback.
571  */
572 typedef enum
573 {
574   GST_PAD_PROBE_DROP,
575   GST_PAD_PROBE_OK,
576   GST_PAD_PROBE_REMOVE,
577   GST_PAD_PROBE_PASS,
578   GST_PAD_PROBE_HANDLED
579 } GstPadProbeReturn;
580 
581 
582 /**
583  * GstPadProbeInfo:
584  * @type: the current probe type
585  * @id: the id of the probe
586  * @data: (allow-none): type specific data, check the @type field to know the
587  *    datatype.  This field can be %NULL.
588  * @offset: offset of pull probe, this field is valid when @type contains
589  *    #GST_PAD_PROBE_TYPE_PULL
590  * @size: size of pull probe, this field is valid when @type contains
591  *    #GST_PAD_PROBE_TYPE_PULL
592  *
593  * Info passed in the #GstPadProbeCallback.
594  */
595 struct _GstPadProbeInfo
596 {
597   GstPadProbeType type;
598   gulong id;
599   gpointer data;
600   guint64 offset;
601   guint size;
602 
603   /*< private >*/
604   union {
605     gpointer _gst_reserved[GST_PADDING];
606     struct {
607       GstFlowReturn flow_ret;
608     } abi;
609   } ABI;
610 };
611 
612 #define GST_PAD_PROBE_INFO_TYPE(d)         ((d)->type)
613 #define GST_PAD_PROBE_INFO_ID(d)           ((d)->id)
614 #define GST_PAD_PROBE_INFO_DATA(d)         ((d)->data)
615 #define GST_PAD_PROBE_INFO_FLOW_RETURN(d)  ((d)->ABI.abi.flow_ret)
616 
617 #define GST_PAD_PROBE_INFO_BUFFER(d)       GST_BUFFER_CAST(GST_PAD_PROBE_INFO_DATA(d))
618 #define GST_PAD_PROBE_INFO_BUFFER_LIST(d)  GST_BUFFER_LIST_CAST(GST_PAD_PROBE_INFO_DATA(d))
619 #define GST_PAD_PROBE_INFO_EVENT(d)        GST_EVENT_CAST(GST_PAD_PROBE_INFO_DATA(d))
620 #define GST_PAD_PROBE_INFO_QUERY(d)        GST_QUERY_CAST(GST_PAD_PROBE_INFO_DATA(d))
621 
622 #define GST_PAD_PROBE_INFO_OFFSET(d)       ((d)->offset)
623 #define GST_PAD_PROBE_INFO_SIZE(d)         ((d)->size)
624 
625 GST_API
626 GstEvent*      gst_pad_probe_info_get_event       (GstPadProbeInfo * info);
627 
628 GST_API
629 GstQuery*      gst_pad_probe_info_get_query       (GstPadProbeInfo * info);
630 
631 GST_API
632 GstBuffer*     gst_pad_probe_info_get_buffer      (GstPadProbeInfo * info);
633 
634 GST_API
635 GstBufferList* gst_pad_probe_info_get_buffer_list (GstPadProbeInfo * info);
636 
637 /**
638  * GstPadProbeCallback:
639  * @pad: the #GstPad that is blocked
640  * @info: #GstPadProbeInfo
641  * @user_data: the gpointer to optional user data.
642  *
643  * Callback used by gst_pad_add_probe(). Gets called to notify about the current
644  * blocking type.
645  *
646  * The callback is allowed to modify the data pointer in @info.
647  *
648  * Returns: a #GstPadProbeReturn
649  */
650 typedef GstPadProbeReturn   (*GstPadProbeCallback)   (GstPad *pad, GstPadProbeInfo *info,
651                                                       gpointer user_data);
652 
653 /**
654  * GstPadStickyEventsForeachFunction:
655  * @pad: the #GstPad.
656  * @event: (allow-none): a sticky #GstEvent.
657  * @user_data: the #gpointer to optional user data.
658  *
659  * Callback used by gst_pad_sticky_events_foreach().
660  *
661  * When this function returns %TRUE, the next event will be
662  * returned. When %FALSE is returned, gst_pad_sticky_events_foreach() will return.
663  *
664  * When @event is set to %NULL, the item will be removed from the list of sticky events.
665  * @event can be replaced by assigning a new reference to it.
666  * This function is responsible for unreffing the old event when
667  * removing or modifying.
668  *
669  * Returns: %TRUE if the iteration should continue
670  */
671 typedef gboolean  (*GstPadStickyEventsForeachFunction) (GstPad *pad, GstEvent **event,
672                                                         gpointer user_data);
673 
674 /**
675  * GstPadFlags:
676  * @GST_PAD_FLAG_BLOCKED: is dataflow on a pad blocked
677  * @GST_PAD_FLAG_FLUSHING: is pad flushing
678  * @GST_PAD_FLAG_EOS: is pad in EOS state
679  * @GST_PAD_FLAG_BLOCKING: is pad currently blocking on a buffer or event
680  * @GST_PAD_FLAG_NEED_PARENT: ensure that there is a parent object before calling
681  *                       into the pad callbacks.
682  * @GST_PAD_FLAG_NEED_RECONFIGURE: the pad should be reconfigured/renegotiated.
683  *                            The flag has to be unset manually after
684  *                            reconfiguration happened.
685  * @GST_PAD_FLAG_PENDING_EVENTS: the pad has pending events
686  * @GST_PAD_FLAG_FIXED_CAPS: the pad is using fixed caps. This means that
687  *     once the caps are set on the pad, the default caps query function
688  *     will only return those caps.
689  * @GST_PAD_FLAG_PROXY_CAPS: the default event and query handler will forward
690  *                      all events and queries to the internally linked pads
691  *                      instead of discarding them.
692  * @GST_PAD_FLAG_PROXY_ALLOCATION: the default query handler will forward
693  *                      allocation queries to the internally linked pads
694  *                      instead of discarding them.
695  * @GST_PAD_FLAG_PROXY_SCHEDULING: the default query handler will forward
696  *                      scheduling queries to the internally linked pads
697  *                      instead of discarding them.
698  * @GST_PAD_FLAG_ACCEPT_INTERSECT: the default accept-caps handler will check
699  *                      it the caps intersect the query-caps result instead
700  *                      of checking for a subset. This is interesting for
701  *                      parsers that can accept incompletely specified caps.
702  * @GST_PAD_FLAG_ACCEPT_TEMPLATE: the default accept-caps handler will use
703  *                      the template pad caps instead of query caps to
704  *                      compare with the accept caps. Use this in combination
705  *                      with %GST_PAD_FLAG_ACCEPT_INTERSECT. (Since: 1.6)
706  * @GST_PAD_FLAG_LAST: offset to define more flags
707  *
708  * Pad state flags
709  */
710 typedef enum {
711   GST_PAD_FLAG_BLOCKED          = (GST_OBJECT_FLAG_LAST << 0),
712   GST_PAD_FLAG_FLUSHING         = (GST_OBJECT_FLAG_LAST << 1),
713   GST_PAD_FLAG_EOS              = (GST_OBJECT_FLAG_LAST << 2),
714   GST_PAD_FLAG_BLOCKING         = (GST_OBJECT_FLAG_LAST << 3),
715   GST_PAD_FLAG_NEED_PARENT      = (GST_OBJECT_FLAG_LAST << 4),
716   GST_PAD_FLAG_NEED_RECONFIGURE = (GST_OBJECT_FLAG_LAST << 5),
717   GST_PAD_FLAG_PENDING_EVENTS   = (GST_OBJECT_FLAG_LAST << 6),
718   GST_PAD_FLAG_FIXED_CAPS       = (GST_OBJECT_FLAG_LAST << 7),
719   GST_PAD_FLAG_PROXY_CAPS       = (GST_OBJECT_FLAG_LAST << 8),
720   GST_PAD_FLAG_PROXY_ALLOCATION = (GST_OBJECT_FLAG_LAST << 9),
721   GST_PAD_FLAG_PROXY_SCHEDULING = (GST_OBJECT_FLAG_LAST << 10),
722   GST_PAD_FLAG_ACCEPT_INTERSECT = (GST_OBJECT_FLAG_LAST << 11),
723   GST_PAD_FLAG_ACCEPT_TEMPLATE  = (GST_OBJECT_FLAG_LAST << 12),
724   /* padding */
725   GST_PAD_FLAG_LAST        = (GST_OBJECT_FLAG_LAST << 16)
726 } GstPadFlags;
727 
728 /**
729  * GstPad:
730  * @element_private: private data owned by the parent element
731  * @padtemplate: padtemplate for this pad
732  * @direction: the direction of the pad, cannot change after creating
733  *             the pad.
734  *
735  * The #GstPad structure. Use the functions to update the variables.
736  */
737 struct _GstPad {
738   GstObject                      object;
739 
740   /*< public >*/
741   gpointer                       element_private;
742 
743   GstPadTemplate                *padtemplate;
744 
745   GstPadDirection                direction;
746 
747   /*< private >*/
748   /* streaming rec_lock */
749   GRecMutex		         stream_rec_lock;
750   GstTask			*task;
751 
752   /* block cond, mutex is from the object */
753   GCond				 block_cond;
754   GHookList                      probes;
755 
756   GstPadMode		         mode;
757   GstPadActivateFunction	 activatefunc;
758   gpointer                       activatedata;
759   GDestroyNotify                 activatenotify;
760   GstPadActivateModeFunction	 activatemodefunc;
761   gpointer                       activatemodedata;
762   GDestroyNotify                 activatemodenotify;
763 
764   /* pad link */
765   GstPad			*peer;
766   GstPadLinkFunction		 linkfunc;
767   gpointer                       linkdata;
768   GDestroyNotify                 linknotify;
769   GstPadUnlinkFunction		 unlinkfunc;
770   gpointer                       unlinkdata;
771   GDestroyNotify                 unlinknotify;
772 
773   /* data transport functions */
774   GstPadChainFunction		 chainfunc;
775   gpointer                       chaindata;
776   GDestroyNotify                 chainnotify;
777   GstPadChainListFunction        chainlistfunc;
778   gpointer                       chainlistdata;
779   GDestroyNotify                 chainlistnotify;
780   GstPadGetRangeFunction	 getrangefunc;
781   gpointer                       getrangedata;
782   GDestroyNotify                 getrangenotify;
783   GstPadEventFunction		 eventfunc;
784   gpointer                       eventdata;
785   GDestroyNotify                 eventnotify;
786 
787   /* pad offset */
788   gint64                         offset;
789 
790   /* generic query method */
791   GstPadQueryFunction		 queryfunc;
792   gpointer                       querydata;
793   GDestroyNotify                 querynotify;
794 
795   /* internal links */
796   GstPadIterIntLinkFunction      iterintlinkfunc;
797   gpointer                       iterintlinkdata;
798   GDestroyNotify                 iterintlinknotify;
799 
800   /* counts number of probes attached. */
801   gint				 num_probes;
802   gint				 num_blocked;
803 
804   GstPadPrivate                 *priv;
805 
806   union {
807     gpointer _gst_reserved[GST_PADDING];
808     struct {
809       GstFlowReturn last_flowret;
810       GstPadEventFullFunction eventfullfunc;
811     } abi;
812   } ABI;
813 };
814 
815 struct _GstPadClass {
816   GstObjectClass	parent_class;
817 
818   /* signal callbacks */
819   void		(*linked)		(GstPad *pad, GstPad *peer);
820   void		(*unlinked)		(GstPad *pad, GstPad *peer);
821 
822   /*< private >*/
823   gpointer _gst_reserved[GST_PADDING];
824 };
825 
826 
827 /***** helper macros *****/
828 /* GstPad */
829 
830 /**
831  * GST_PAD_NAME:
832  * @pad: a #GstPad
833  *
834  * Get name of the given pad.
835  * No locking is performed in this function, use gst_pad_get_name() instead.
836  */
837 #define GST_PAD_NAME(pad)		(GST_OBJECT_NAME(pad))
838 /**
839  * GST_PAD_PARENT:
840  * @pad: a #GstPad
841  *
842  * Get the @pad parent.
843  * No locking is performed in this function, use gst_pad_get_parent() instead.
844  */
845 #define GST_PAD_PARENT(pad)		(GST_ELEMENT_CAST(GST_OBJECT_PARENT(pad)))
846 /**
847  * GST_PAD_ELEMENT_PRIVATE:
848  * @pad: a #GstPad
849  *
850  * Get the private data of @pad, which is usually some pad- or stream-specific
851  * structure created by the element and set on the pad when creating it.
852  * No locking is performed in this function.
853  */
854 #define GST_PAD_ELEMENT_PRIVATE(pad)    (GST_PAD_CAST(pad)->element_private)
855 /**
856  * GST_PAD_PAD_TEMPLATE:
857  * @pad: a #GstPad
858  *
859  * Get the @pad #GstPadTemplate. It describes the possible media types
860  * a @pad or an element factory can handle.
861  */
862 #define GST_PAD_PAD_TEMPLATE(pad)	(GST_PAD_CAST(pad)->padtemplate)
863 /**
864  * GST_PAD_DIRECTION:
865  * @pad: a #GstPad
866  *
867  * Get the #GstPadDirection of the given @pad. Accessor macro, use
868  * gst_pad_get_direction() instead.
869  */
870 #define GST_PAD_DIRECTION(pad)		(GST_PAD_CAST(pad)->direction)
871 /**
872  * GST_PAD_TASK:
873  * @pad: a #GstPad
874  *
875  * Get the #GstTask of @pad. Accessor macro used by GStreamer. Use the
876  * gst_pad_start_task(), gst_pad_stop_task() and gst_pad_pause_task()
877  * functions instead.
878  */
879 #define GST_PAD_TASK(pad)		(GST_PAD_CAST(pad)->task)
880 /**
881  * GST_PAD_MODE:
882  * @pad: a #GstPad
883  *
884  * Get the #GstPadMode of pad, which will be GST_PAD_MODE_NONE if the pad
885  * has not been activated yet, and otherwise either GST_PAD_MODE_PUSH or
886  * GST_PAD_MODE_PULL depending on which mode the pad was activated in.
887  */
888 #define GST_PAD_MODE(pad)	        (GST_PAD_CAST(pad)->mode)
889 /**
890  * GST_PAD_ACTIVATEFUNC:
891  * @pad: a #GstPad
892  *
893  * Get the #GstPadActivateFunction from @pad.
894  */
895 #define GST_PAD_ACTIVATEFUNC(pad)	(GST_PAD_CAST(pad)->activatefunc)
896 /**
897  * GST_PAD_ACTIVATEMODEFUNC:
898  * @pad: a #GstPad
899  *
900  * Get the #GstPadActivateModeFunction from the given @pad.
901  */
902 #define GST_PAD_ACTIVATEMODEFUNC(pad)	(GST_PAD_CAST(pad)->activatemodefunc)
903 /**
904  * GST_PAD_CHAINFUNC:
905  * @pad: a #GstPad
906  *
907  * Get the #GstPadChainFunction from the given @pad.
908  */
909 #define GST_PAD_CHAINFUNC(pad)		(GST_PAD_CAST(pad)->chainfunc)
910 /**
911  * GST_PAD_CHAINLISTFUNC:
912  * @pad: a #GstPad
913  *
914  * Get the #GstPadChainListFunction from the given @pad.
915  */
916 #define GST_PAD_CHAINLISTFUNC(pad)      (GST_PAD_CAST(pad)->chainlistfunc)
917 /**
918  * GST_PAD_GETRANGEFUNC:
919  * @pad: a #GstPad
920  *
921  * Get the #GstPadGetRangeFunction from the given @pad.
922  */
923 #define GST_PAD_GETRANGEFUNC(pad)	(GST_PAD_CAST(pad)->getrangefunc)
924 /**
925  * GST_PAD_EVENTFUNC:
926  * @pad: a #GstPad
927  *
928  * Get the #GstPadEventFunction from the given @pad, which
929  * is the function that handles events on the pad. You can
930  * use this to set your own event handling function on a pad
931  * after you create it.  If your element derives from a base
932  * class, use the base class's virtual functions instead.
933  */
934 #define GST_PAD_EVENTFUNC(pad)		(GST_PAD_CAST(pad)->eventfunc)
935 /**
936  * GST_PAD_EVENTFULLFUNC:
937  * @pad: a #GstPad
938  *
939  * Get the #GstPadEventFullFunction from the given @pad, which
940  * is the function that handles events on the pad. You can
941  * use this to set your own event handling function on a pad
942  * after you create it.  If your element derives from a base
943  * class, use the base class's virtual functions instead.
944  *
945  * Since: 1.8
946  */
947 #define GST_PAD_EVENTFULLFUNC(pad)	(GST_PAD_CAST(pad)->ABI.abi.eventfullfunc)
948 /**
949  * GST_PAD_QUERYFUNC:
950  * @pad: a #GstPad
951  *
952  * Get the #GstPadQueryFunction from @pad, which is the function
953  * that handles queries on the pad. You can  use this to set your
954  * own query handling function on a pad after you create it. If your
955  * element derives from a base class, use the base class's virtual
956  * functions instead.
957  */
958 #define GST_PAD_QUERYFUNC(pad)		(GST_PAD_CAST(pad)->queryfunc)
959 /**
960  * GST_PAD_ITERINTLINKFUNC:
961  * @pad: a #GstPad
962  *
963  * Get the #GstPadIterIntLinkFunction from the given @pad.
964  */
965 #define GST_PAD_ITERINTLINKFUNC(pad)    (GST_PAD_CAST(pad)->iterintlinkfunc)
966 /**
967  * GST_PAD_PEER:
968  * @pad: a #GstPad
969  *
970  * Return the pad's peer member. This member is a pointer to the linked @pad.
971  * No locking is performed in this function, use gst_pad_get_peer() instead.
972  */
973 #define GST_PAD_PEER(pad)		(GST_PAD_CAST(pad)->peer)
974 /**
975  * GST_PAD_LINKFUNC:
976  * @pad: a #GstPad
977  *
978  * Get the #GstPadLinkFunction for the given @pad.
979  */
980 #define GST_PAD_LINKFUNC(pad)		(GST_PAD_CAST(pad)->linkfunc)
981 /**
982  * GST_PAD_UNLINKFUNC:
983  * @pad: a #GstPad
984  *
985  * Get the #GstPadUnlinkFunction from the given @pad.
986  */
987 #define GST_PAD_UNLINKFUNC(pad)		(GST_PAD_CAST(pad)->unlinkfunc)
988 /**
989  * GST_PAD_IS_SRC:
990  * @pad: a #GstPad
991  *
992  * Returns: %TRUE if the pad is a source pad (i.e. produces data).
993  */
994 #define GST_PAD_IS_SRC(pad)		(GST_PAD_DIRECTION(pad) == GST_PAD_SRC)
995 /**
996  * GST_PAD_IS_SINK:
997  * @pad: a #GstPad
998  *
999  * Returns: %TRUE if the pad is a sink pad (i.e. consumes data).
1000  */
1001 #define GST_PAD_IS_SINK(pad)		(GST_PAD_DIRECTION(pad) == GST_PAD_SINK)
1002 /**
1003  * GST_PAD_IS_LINKED:
1004  * @pad: a #GstPad
1005  *
1006  * Returns: %TRUE if the pad is linked to another pad. Use gst_pad_is_linked()
1007  * instead.
1008  */
1009 #define GST_PAD_IS_LINKED(pad)		(GST_PAD_PEER(pad) != NULL)
1010 /**
1011  * GST_PAD_IS_ACTIVE:
1012  * @pad: a #GstPad
1013  *
1014  * Returns: %TRUE if the pad has been activated.
1015  */
1016 #define GST_PAD_IS_ACTIVE(pad)          (GST_PAD_MODE(pad) != GST_PAD_MODE_NONE)
1017 /**
1018  * GST_PAD_IS_BLOCKED:
1019  * @pad: a #GstPad
1020  *
1021  * Check if the dataflow on a @pad is blocked. Use gst_pad_is_blocked() instead.
1022  */
1023 #define GST_PAD_IS_BLOCKED(pad)		(GST_OBJECT_FLAG_IS_SET (pad, GST_PAD_FLAG_BLOCKED))
1024 /**
1025  * GST_PAD_IS_BLOCKING:
1026  * @pad: a #GstPad
1027  *
1028  * Check if the @pad is currently blocking on a buffer or event. Use
1029  * gst_pad_is_blocking() instead.
1030  */
1031 #define GST_PAD_IS_BLOCKING(pad)	(GST_OBJECT_FLAG_IS_SET (pad, GST_PAD_FLAG_BLOCKING))
1032 /**
1033  * GST_PAD_IS_FLUSHING:
1034  * @pad: a #GstPad
1035  *
1036  * Check if the given @pad is flushing.
1037  */
1038 #define GST_PAD_IS_FLUSHING(pad)	(GST_OBJECT_FLAG_IS_SET (pad, GST_PAD_FLAG_FLUSHING))
1039 /**
1040  * GST_PAD_SET_FLUSHING:
1041  * @pad: a #GstPad
1042  *
1043  * Set the given @pad to flushing state, which means it will not accept any
1044  * more events, queries or buffers, and return GST_FLOW_FLUSHING if any buffers
1045  * are pushed on it. This usually happens when the pad is shut down or when
1046  * a flushing seek happens. This is used inside GStreamer when flush start/stop
1047  * events pass through pads, or when an element state is changed and pads are
1048  * activated or deactivated.
1049  */
1050 #define GST_PAD_SET_FLUSHING(pad)	(GST_OBJECT_FLAG_SET (pad, GST_PAD_FLAG_FLUSHING))
1051 /**
1052  * GST_PAD_UNSET_FLUSHING:
1053  * @pad: a #GstPad
1054  *
1055  * Unset the flushing flag.
1056  */
1057 #define GST_PAD_UNSET_FLUSHING(pad)	(GST_OBJECT_FLAG_UNSET (pad, GST_PAD_FLAG_FLUSHING))
1058 /**
1059  * GST_PAD_IS_EOS:
1060  * @pad: a #GstPad
1061  *
1062  * Check if the @pad is in EOS state.
1063  */
1064 #define GST_PAD_IS_EOS(pad)	        (GST_OBJECT_FLAG_IS_SET (pad, GST_PAD_FLAG_EOS))
1065 /**
1066  * GST_PAD_NEEDS_RECONFIGURE:
1067  * @pad: a #GstPad
1068  *
1069  * Check if the @pad should be reconfigured/renegotiated.
1070  * The flag has to be unset manually after reconfiguration happened.
1071  * Use gst_pad_needs_reconfigure() or gst_pad_check_reconfigure() instead.
1072  */
1073 #define GST_PAD_NEEDS_RECONFIGURE(pad)  (GST_OBJECT_FLAG_IS_SET (pad, GST_PAD_FLAG_NEED_RECONFIGURE))
1074 /**
1075  * GST_PAD_HAS_PENDING_EVENTS:
1076  * @pad: a #GstPad
1077  *
1078  * Check if the given @pad has pending events. This is used internally by
1079  * GStreamer.
1080  */
1081 #define GST_PAD_HAS_PENDING_EVENTS(pad) (GST_OBJECT_FLAG_IS_SET (pad, GST_PAD_FLAG_PENDING_EVENTS))
1082 /**
1083  * GST_PAD_IS_FIXED_CAPS:
1084  * @pad: a #GstPad
1085  *
1086  * Check if the given @pad is using fixed caps, which means that
1087  * once the caps are set on the @pad, the caps query function will
1088  * only return those caps. See gst_pad_use_fixed_caps().
1089  */
1090 #define GST_PAD_IS_FIXED_CAPS(pad)	(GST_OBJECT_FLAG_IS_SET (pad, GST_PAD_FLAG_FIXED_CAPS))
1091 /**
1092  * GST_PAD_NEEDS_PARENT:
1093  * @pad: a #GstPad
1094  *
1095  * Check if there is a parent object before calling into the @pad callbacks.
1096  * This is used internally by GStreamer.
1097  */
1098 #define GST_PAD_NEEDS_PARENT(pad)       (GST_OBJECT_FLAG_IS_SET (pad, GST_PAD_FLAG_NEED_PARENT))
1099 /**
1100  * GST_PAD_IS_PROXY_CAPS:
1101  * @pad: a #GstPad
1102  *
1103  * Check if the given @pad is set to proxy caps. This means that the default
1104  * event and query handler will forward all events and queries to the
1105  * internally linked @pads instead of discarding them.
1106  */
1107 #define GST_PAD_IS_PROXY_CAPS(pad)      (GST_OBJECT_FLAG_IS_SET (pad, GST_PAD_FLAG_PROXY_CAPS))
1108 /**
1109  * GST_PAD_SET_PROXY_CAPS:
1110  * @pad: a #GstPad
1111  *
1112  * Set @pad to proxy caps, so that all caps-related events and queries are
1113  * proxied down- or upstream to the other side of the element automatically.
1114  * Set this if the element always outputs data in the exact same format as it
1115  * receives as input. This is just for convenience to avoid implementing some
1116  * standard event and query handling code in an element.
1117  */
1118 #define GST_PAD_SET_PROXY_CAPS(pad)     (GST_OBJECT_FLAG_SET (pad, GST_PAD_FLAG_PROXY_CAPS))
1119 /**
1120  * GST_PAD_UNSET_PROXY_CAPS:
1121  * @pad: a #GstPad
1122  *
1123  * Unset proxy caps flag.
1124  */
1125 #define GST_PAD_UNSET_PROXY_CAPS(pad)   (GST_OBJECT_FLAG_UNSET (pad, GST_PAD_FLAG_PROXY_CAPS))
1126 /**
1127  * GST_PAD_IS_PROXY_ALLOCATION:
1128  * @pad: a #GstPad
1129  *
1130  * Check if the given @pad is set as proxy allocation which means
1131  * that the default query handler will forward allocation queries to the
1132  * internally linked @pads instead of discarding them.
1133  */
1134 #define GST_PAD_IS_PROXY_ALLOCATION(pad)    (GST_OBJECT_FLAG_IS_SET (pad, GST_PAD_FLAG_PROXY_ALLOCATION))
1135 /**
1136  * GST_PAD_SET_PROXY_ALLOCATION:
1137  * @pad: a #GstPad
1138  *
1139  * Set @pad to proxy allocation queries, which means that the default query
1140  * handler will forward allocation queries to the internally linked @pads
1141  * instead of discarding them.
1142  * Set this if the element always outputs data in the exact same format as it
1143  * receives as input. This is just for convenience to avoid implementing some
1144  * standard query handling code in an element.
1145  */
1146 #define GST_PAD_SET_PROXY_ALLOCATION(pad)   (GST_OBJECT_FLAG_SET (pad, GST_PAD_FLAG_PROXY_ALLOCATION))
1147 /**
1148  * GST_PAD_UNSET_PROXY_ALLOCATION:
1149  * @pad: a #GstPad
1150  *
1151  * Unset proxy allocation flag.
1152  */
1153 #define GST_PAD_UNSET_PROXY_ALLOCATION(pad) (GST_OBJECT_FLAG_UNSET (pad, GST_PAD_FLAG_PROXY_ALLOCATION))
1154 /**
1155  * GST_PAD_IS_PROXY_SCHEDULING:
1156  * @pad: a #GstPad
1157  *
1158  * Check if the given @pad is set to proxy scheduling queries, which means that
1159  * the default query handler will forward scheduling queries to the internally
1160  * linked @pads instead of discarding them.
1161  */
1162 #define GST_PAD_IS_PROXY_SCHEDULING(pad)    (GST_OBJECT_FLAG_IS_SET (pad, GST_PAD_FLAG_PROXY_SCHEDULING))
1163 /**
1164  * GST_PAD_SET_PROXY_SCHEDULING:
1165  * @pad: a #GstPad
1166  *
1167  * Set @pad to proxy scheduling queries, which means that the default query
1168  * handler will forward scheduling queries to the internally linked @pads
1169  * instead of discarding them. You will usually want to handle scheduling
1170  * queries explicitly if your element supports multiple scheduling modes.
1171  */
1172 #define GST_PAD_SET_PROXY_SCHEDULING(pad)   (GST_OBJECT_FLAG_SET (pad, GST_PAD_FLAG_PROXY_SCHEDULING))
1173 /**
1174  * GST_PAD_UNSET_PROXY_SCHEDULING:
1175  * @pad: a #GstPad
1176  *
1177  * Unset proxy scheduling flag.
1178  */
1179 #define GST_PAD_UNSET_PROXY_SCHEDULING(pad) (GST_OBJECT_FLAG_UNSET (pad, GST_PAD_FLAG_PROXY_SCHEDULING))
1180 /**
1181  * GST_PAD_IS_ACCEPT_INTERSECT:
1182  * @pad: a #GstPad
1183  *
1184  * Check if the pad's accept intersect flag is set. The default accept-caps
1185  * handler will check if the caps intersect the query-caps result instead of
1186  * checking for a subset. This is interesting for parser elements that can
1187  * accept incompletely specified caps.
1188  */
1189 #define GST_PAD_IS_ACCEPT_INTERSECT(pad)    (GST_OBJECT_FLAG_IS_SET (pad, GST_PAD_FLAG_ACCEPT_INTERSECT))
1190 /**
1191  * GST_PAD_SET_ACCEPT_INTERSECT:
1192  * @pad: a #GstPad
1193  *
1194  * Set @pad to by default accept caps by intersecting the result instead of
1195  * checking for a subset. This is interesting for parser elements that can
1196  * accept incompletely specified caps.
1197  */
1198 #define GST_PAD_SET_ACCEPT_INTERSECT(pad)   (GST_OBJECT_FLAG_SET (pad, GST_PAD_FLAG_ACCEPT_INTERSECT))
1199 /**
1200  * GST_PAD_UNSET_ACCEPT_INTERSECT:
1201  * @pad: a #GstPad
1202  *
1203  * Unset accept intersect flag.
1204  */
1205 #define GST_PAD_UNSET_ACCEPT_INTERSECT(pad) (GST_OBJECT_FLAG_UNSET (pad, GST_PAD_FLAG_ACCEPT_INTERSECT))
1206 /**
1207  * GST_PAD_IS_ACCEPT_TEMPLATE:
1208  * @pad: a #GstPad
1209  *
1210  * Check if the pad's accept caps operation will use the pad template caps.
1211  * The default accept-caps will do a query caps to get the caps, which might
1212  * be querying downstream causing unnecessary overhead. It is recommended to
1213  * implement a proper accept-caps query handler or to use this flag to prevent
1214  * recursive accept-caps handling.
1215  *
1216  * Since: 1.6
1217  */
1218 #define GST_PAD_IS_ACCEPT_TEMPLATE(pad)    (GST_OBJECT_FLAG_IS_SET (pad, GST_PAD_FLAG_ACCEPT_TEMPLATE))
1219 /**
1220  * GST_PAD_SET_ACCEPT_TEMPLATE:
1221  * @pad: a #GstPad
1222  *
1223  * Set @pad to by default use the pad template caps to compare with
1224  * the accept caps instead of using a caps query result.
1225  *
1226  * Since: 1.6
1227  */
1228 #define GST_PAD_SET_ACCEPT_TEMPLATE(pad)   (GST_OBJECT_FLAG_SET (pad, GST_PAD_FLAG_ACCEPT_TEMPLATE))
1229 /**
1230  * GST_PAD_UNSET_ACCEPT_TEMPLATE:
1231  * @pad: a #GstPad
1232  *
1233  * Unset accept template flag.
1234  *
1235  * Since: 1.6
1236  */
1237 #define GST_PAD_UNSET_ACCEPT_TEMPLATE(pad) (GST_OBJECT_FLAG_UNSET (pad, GST_PAD_FLAG_ACCEPT_TEMPLATE))
1238 /**
1239  * GST_PAD_GET_STREAM_LOCK:
1240  * @pad: a #GstPad
1241  *
1242  * Get the stream lock of @pad. The stream lock is protecting the
1243  * resources used in the data processing functions of @pad. Accessor
1244  * macro, use GST_PAD_STREAM_LOCK() and GST_PAD_STREAM_UNLOCK() instead
1245  * to take/release the pad's stream lock.
1246  */
1247 #define GST_PAD_GET_STREAM_LOCK(pad)    (&(GST_PAD_CAST(pad)->stream_rec_lock))
1248 /**
1249  * GST_PAD_STREAM_LOCK:
1250  * @pad: a #GstPad
1251  *
1252  * Take the pad's stream lock. The stream lock is recursive and will be taken
1253  * when buffers or serialized downstream events are pushed on a pad.
1254  */
1255 #define GST_PAD_STREAM_LOCK(pad)        g_rec_mutex_lock(GST_PAD_GET_STREAM_LOCK(pad))
1256 /**
1257  * GST_PAD_STREAM_TRYLOCK:
1258  * @pad: a #GstPad
1259  *
1260  * Try to take the pad's stream lock, and return %TRUE if the lock could be
1261  * taken, and otherwise %FALSE.
1262  */
1263 #define GST_PAD_STREAM_TRYLOCK(pad)     g_rec_mutex_trylock(GST_PAD_GET_STREAM_LOCK(pad))
1264 /**
1265  * GST_PAD_STREAM_UNLOCK:
1266  * @pad: a #GstPad
1267  *
1268  * Release the pad's stream lock.
1269  */
1270 #define GST_PAD_STREAM_UNLOCK(pad)      g_rec_mutex_unlock(GST_PAD_GET_STREAM_LOCK(pad))
1271 /**
1272  * GST_PAD_LAST_FLOW_RETURN:
1273  * @pad: a #GstPad
1274  *
1275  * Gets the last flow return on this pad
1276  *
1277  * Since: 1.4
1278  */
1279 #define GST_PAD_LAST_FLOW_RETURN(pad)   (GST_PAD_CAST(pad)->ABI.abi.last_flowret)
1280 
1281 #define GST_PAD_BLOCK_GET_COND(pad)     (&GST_PAD_CAST(pad)->block_cond)
1282 #define GST_PAD_BLOCK_WAIT(pad)         (g_cond_wait(GST_PAD_BLOCK_GET_COND (pad), GST_OBJECT_GET_LOCK (pad)))
1283 #define GST_PAD_BLOCK_SIGNAL(pad)       (g_cond_signal(GST_PAD_BLOCK_GET_COND (pad)))
1284 #define GST_PAD_BLOCK_BROADCAST(pad)    (g_cond_broadcast(GST_PAD_BLOCK_GET_COND (pad)))
1285 
1286 GST_API
1287 GType			gst_pad_get_type			(void);
1288 
1289 /* creating pads */
1290 
1291 GST_API
1292 GstPad*			gst_pad_new				(const gchar *name, GstPadDirection direction);
1293 
1294 GST_API
1295 GstPad*			gst_pad_new_from_template		(GstPadTemplate *templ, const gchar *name);
1296 
1297 GST_API
1298 GstPad*			gst_pad_new_from_static_template	(GstStaticPadTemplate *templ, const gchar *name);
1299 
1300 
1301 /**
1302  * gst_pad_get_name:
1303  * @pad: the pad to get the name from
1304  *
1305  * Get a copy of the name of the pad. g_free() after usage.
1306  *
1307  * MT safe.
1308  */
1309 #define gst_pad_get_name(pad) gst_object_get_name (GST_OBJECT_CAST (pad))
1310 /**
1311  * gst_pad_get_parent:
1312  * @pad: the pad to get the parent of
1313  *
1314  * Get the parent of @pad. This function increases the refcount
1315  * of the parent object so you should gst_object_unref() it after usage.
1316  * Can return %NULL if the pad did not have a parent.
1317  *
1318  * MT safe.
1319  *
1320  * Returns: (nullable): the parent
1321  */
1322 #define gst_pad_get_parent(pad) gst_object_get_parent (GST_OBJECT_CAST (pad))
1323 
1324 GST_API
1325 GstPadDirection		gst_pad_get_direction			(GstPad *pad);
1326 
1327 GST_API
1328 gboolean		gst_pad_set_active			(GstPad *pad, gboolean active);
1329 
1330 GST_API
1331 gboolean		gst_pad_is_active			(GstPad *pad);
1332 
1333 GST_API
1334 gboolean		gst_pad_activate_mode			(GstPad *pad, GstPadMode mode,
1335                                                                  gboolean active);
1336 GST_API
1337 gulong                  gst_pad_add_probe                       (GstPad *pad,
1338 								 GstPadProbeType mask,
1339 								 GstPadProbeCallback callback,
1340                                                                  gpointer user_data,
1341                                                                  GDestroyNotify destroy_data);
1342 GST_API
1343 void                    gst_pad_remove_probe                    (GstPad *pad, gulong id);
1344 
1345 GST_API
1346 gboolean		gst_pad_is_blocked			(GstPad *pad);
1347 
1348 GST_API
1349 gboolean		gst_pad_is_blocking			(GstPad *pad);
1350 
1351 GST_API
1352 void                    gst_pad_mark_reconfigure                (GstPad *pad);
1353 
1354 GST_API
1355 gboolean		gst_pad_needs_reconfigure               (GstPad *pad);
1356 
1357 GST_API
1358 gboolean		gst_pad_check_reconfigure               (GstPad *pad);
1359 
1360 GST_API
1361 void			gst_pad_set_element_private		(GstPad *pad, gpointer priv);
1362 
1363 GST_API
1364 gpointer		gst_pad_get_element_private		(GstPad *pad);
1365 
1366 GST_API
1367 GstPadTemplate*		gst_pad_get_pad_template		(GstPad *pad);
1368 
1369 GST_API
1370 GstFlowReturn           gst_pad_store_sticky_event              (GstPad *pad, GstEvent *event);
1371 
1372 GST_API
1373 GstEvent*               gst_pad_get_sticky_event                (GstPad *pad, GstEventType event_type,
1374                                                                  guint idx);
1375 
1376 GST_API
1377 void                    gst_pad_sticky_events_foreach           (GstPad *pad, GstPadStickyEventsForeachFunction foreach_func, gpointer user_data);
1378 
1379 /* data passing setup functions */
1380 
1381 GST_API
1382 void			gst_pad_set_activate_function_full	(GstPad *pad,
1383                                                                  GstPadActivateFunction activate,
1384                                                                  gpointer user_data,
1385                                                                  GDestroyNotify notify);
1386 GST_API
1387 void			gst_pad_set_activatemode_function_full	(GstPad *pad,
1388                                                                  GstPadActivateModeFunction activatemode,
1389                                                                  gpointer user_data,
1390                                                                  GDestroyNotify notify);
1391 /* data passing functions */
1392 
1393 GST_API
1394 void			gst_pad_set_chain_function_full		(GstPad *pad,
1395                                                                  GstPadChainFunction chain,
1396                                                                  gpointer user_data,
1397                                                                  GDestroyNotify notify);
1398 GST_API
1399 void			gst_pad_set_chain_list_function_full	(GstPad *pad,
1400                                                                  GstPadChainListFunction chainlist,
1401                                                                  gpointer user_data,
1402                                                                  GDestroyNotify notify);
1403 GST_API
1404 void			gst_pad_set_getrange_function_full	(GstPad *pad,
1405                                                                  GstPadGetRangeFunction get,
1406                                                                  gpointer user_data,
1407                                                                  GDestroyNotify notify);
1408 GST_API
1409 void			gst_pad_set_event_function_full		(GstPad *pad,
1410                                                                  GstPadEventFunction event,
1411                                                                  gpointer user_data,
1412                                                                  GDestroyNotify notify);
1413 GST_API
1414 void			gst_pad_set_event_full_function_full	(GstPad *pad,
1415                                                                  GstPadEventFullFunction event,
1416                                                                  gpointer user_data,
1417                                                                  GDestroyNotify notify);
1418 
1419 #define gst_pad_set_activate_function(p,f)      gst_pad_set_activate_function_full((p),(f),NULL,NULL)
1420 #define gst_pad_set_activatemode_function(p,f)  gst_pad_set_activatemode_function_full((p),(f),NULL,NULL)
1421 #define gst_pad_set_chain_function(p,f)         gst_pad_set_chain_function_full((p),(f),NULL,NULL)
1422 #define gst_pad_set_chain_list_function(p,f)    gst_pad_set_chain_list_function_full((p),(f),NULL,NULL)
1423 #define gst_pad_set_getrange_function(p,f)      gst_pad_set_getrange_function_full((p),(f),NULL,NULL)
1424 #define gst_pad_set_event_function(p,f)         gst_pad_set_event_function_full((p),(f),NULL,NULL)
1425 #define gst_pad_set_event_full_function(p,f)    gst_pad_set_event_full_function_full((p),(f),NULL,NULL)
1426 
1427 /* pad links */
1428 
1429 GST_API
1430 void			gst_pad_set_link_function_full		(GstPad *pad,
1431                                                                  GstPadLinkFunction link,
1432                                                                  gpointer user_data,
1433                                                                  GDestroyNotify notify);
1434 GST_API
1435 void			gst_pad_set_unlink_function_full        (GstPad *pad,
1436                                                                  GstPadUnlinkFunction unlink,
1437                                                                  gpointer user_data,
1438                                                                  GDestroyNotify notify);
1439 
1440 #define gst_pad_set_link_function(p,f)          gst_pad_set_link_function_full((p),(f),NULL,NULL)
1441 #define gst_pad_set_unlink_function(p,f)        gst_pad_set_unlink_function_full((p),(f),NULL,NULL)
1442 
1443 GST_API
1444 gboolean                gst_pad_can_link                        (GstPad *srcpad, GstPad *sinkpad);
1445 
1446 GST_API
1447 GstPadLinkReturn        gst_pad_link				(GstPad *srcpad, GstPad *sinkpad);
1448 
1449 GST_API
1450 GstPadLinkReturn        gst_pad_link_full			(GstPad *srcpad, GstPad *sinkpad, GstPadLinkCheck flags);
1451 
1452 GST_API
1453 gboolean		gst_pad_unlink				(GstPad *srcpad, GstPad *sinkpad);
1454 
1455 GST_API
1456 gboolean		gst_pad_is_linked			(GstPad *pad);
1457 
1458 GST_API
1459 GstPad*			gst_pad_get_peer			(GstPad *pad);
1460 
1461 GST_API
1462 GstCaps*                gst_pad_get_pad_template_caps		(GstPad *pad);
1463 
1464 /* capsnego function for linked/unlinked pads */
1465 
1466 GST_API
1467 GstCaps *		gst_pad_get_current_caps                (GstPad * pad);
1468 
1469 GST_API
1470 gboolean		gst_pad_has_current_caps                (GstPad * pad);
1471 
1472 /* capsnego for linked pads */
1473 
1474 GST_API
1475 GstCaps *		gst_pad_get_allowed_caps		(GstPad * pad);
1476 
1477 /* pad offsets */
1478 
1479 GST_API
1480 gint64                  gst_pad_get_offset                      (GstPad *pad);
1481 
1482 GST_API
1483 void                    gst_pad_set_offset                      (GstPad *pad, gint64 offset);
1484 
1485 /* data passing functions to peer */
1486 
1487 GST_API
1488 GstFlowReturn		gst_pad_push				(GstPad *pad, GstBuffer *buffer);
1489 
1490 GST_API
1491 GstFlowReturn		gst_pad_push_list			(GstPad *pad, GstBufferList *list);
1492 
1493 GST_API
1494 GstFlowReturn		gst_pad_pull_range			(GstPad *pad, guint64 offset, guint size,
1495 								 GstBuffer **buffer);
1496 GST_API
1497 gboolean		gst_pad_push_event			(GstPad *pad, GstEvent *event);
1498 
1499 GST_API
1500 gboolean		gst_pad_event_default			(GstPad *pad, GstObject *parent,
1501                                                                  GstEvent *event);
1502 GST_API
1503 GstFlowReturn           gst_pad_get_last_flow_return            (GstPad *pad);
1504 
1505 /* data passing functions on pad */
1506 
1507 GST_API
1508 GstFlowReturn		gst_pad_chain				(GstPad *pad, GstBuffer *buffer);
1509 
1510 GST_API
1511 GstFlowReturn		gst_pad_chain_list                      (GstPad *pad, GstBufferList *list);
1512 
1513 GST_API
1514 GstFlowReturn		gst_pad_get_range			(GstPad *pad, guint64 offset, guint size,
1515 								 GstBuffer **buffer);
1516 GST_API
1517 gboolean		gst_pad_send_event			(GstPad *pad, GstEvent *event);
1518 
1519 /* pad tasks */
1520 
1521 GST_API
1522 gboolean		gst_pad_start_task			(GstPad *pad, GstTaskFunction func,
1523 								 gpointer user_data, GDestroyNotify notify);
1524 GST_API
1525 gboolean		gst_pad_pause_task			(GstPad *pad);
1526 
1527 GST_API
1528 gboolean		gst_pad_stop_task			(GstPad *pad);
1529 
1530 GST_API
1531 GstTaskState	gst_pad_get_task_state		(GstPad *pad);
1532 
1533 /* internal links */
1534 
1535 GST_API
1536 void                    gst_pad_set_iterate_internal_links_function_full (GstPad * pad,
1537                                                                  GstPadIterIntLinkFunction iterintlink,
1538                                                                  gpointer user_data,
1539                                                                  GDestroyNotify notify);
1540 
1541 GST_API
1542 GstIterator *           gst_pad_iterate_internal_links          (GstPad * pad);
1543 
1544 GST_API
1545 GstIterator *           gst_pad_iterate_internal_links_default  (GstPad * pad, GstObject *parent);
1546 
1547 #define gst_pad_set_iterate_internal_links_function(p,f) gst_pad_set_iterate_internal_links_function_full((p),(f),NULL,NULL)
1548 
1549 GST_API
1550 GstPad *                gst_pad_get_single_internal_link        (GstPad * pad);
1551 
1552 /* generic query function */
1553 
1554 GST_API
1555 gboolean		gst_pad_query				(GstPad *pad, GstQuery *query);
1556 
1557 GST_API
1558 gboolean		gst_pad_peer_query			(GstPad *pad, GstQuery *query);
1559 
1560 GST_API
1561 void			gst_pad_set_query_function_full		(GstPad *pad, GstPadQueryFunction query,
1562                                                                  gpointer user_data,
1563                                                                  GDestroyNotify notify);
1564 GST_API
1565 gboolean		gst_pad_query_default			(GstPad *pad, GstObject *parent,
1566                                                                  GstQuery *query);
1567 
1568 #define gst_pad_set_query_function(p,f)   gst_pad_set_query_function_full((p),(f),NULL,NULL)
1569 
1570 /* misc helper functions */
1571 
1572 GST_API
1573 gboolean		gst_pad_forward                         (GstPad *pad, GstPadForwardFunction forward,
1574 								 gpointer user_data);
1575 
1576 G_DEFINE_AUTOPTR_CLEANUP_FUNC(GstPad, gst_object_unref)
1577 
1578 G_END_DECLS
1579 
1580 #endif /* __GST_PAD_H__ */
1581