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

source code of include/gstreamer-1.0/gst/gstpad.h