1/* GStreamer
2 * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
3 * 2000,2004 Wim Taymans <wim@fluendo.com>
4 *
5 * gstelement.h: Header for GstElement
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_ELEMENT_H__
25#define __GST_ELEMENT_H__
26
27#include <glib.h>
28
29G_BEGIN_DECLS
30
31/* gstelement.h and gstelementfactory.h include each other */
32typedef struct _GstElement GstElement;
33typedef struct _GstElementClass GstElementClass;
34
35/* gstmessage.h needs State */
36/**
37 * GstState:
38 * @GST_STATE_VOID_PENDING: no pending state.
39 * @GST_STATE_NULL : the NULL state or initial state of an element.
40 * @GST_STATE_READY : the element is ready to go to PAUSED.
41 * @GST_STATE_PAUSED : the element is PAUSED, it is ready to accept and
42 * process data. Sink elements however only accept one
43 * buffer and then block.
44 * @GST_STATE_PLAYING : the element is PLAYING, the #GstClock is running and
45 * the data is flowing.
46 *
47 * The possible states an element can be in. States can be changed using
48 * gst_element_set_state() and checked using gst_element_get_state().
49 */
50typedef enum {
51 GST_STATE_VOID_PENDING = 0,
52 GST_STATE_NULL = 1,
53 GST_STATE_READY = 2,
54 GST_STATE_PAUSED = 3,
55 GST_STATE_PLAYING = 4
56} GstState;
57
58#define GST_TYPE_ELEMENT (gst_element_get_type ())
59#define GST_IS_ELEMENT(obj) (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GST_TYPE_ELEMENT))
60#define GST_IS_ELEMENT_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GST_TYPE_ELEMENT))
61#define GST_ELEMENT_GET_CLASS(obj) (G_TYPE_INSTANCE_GET_CLASS ((obj), GST_TYPE_ELEMENT, GstElementClass))
62#define GST_ELEMENT(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), GST_TYPE_ELEMENT, GstElement))
63#define GST_ELEMENT_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST ((klass), GST_TYPE_ELEMENT, GstElementClass))
64#define GST_ELEMENT_CAST(obj) ((GstElement*)(obj))
65
66/**
67 * GstStateChangeReturn:
68 * @GST_STATE_CHANGE_FAILURE : the state change failed
69 * @GST_STATE_CHANGE_SUCCESS : the state change succeeded
70 * @GST_STATE_CHANGE_ASYNC : the state change will happen asynchronously
71 * @GST_STATE_CHANGE_NO_PREROLL: the state change succeeded but the element
72 * cannot produce data in %GST_STATE_PAUSED.
73 * This typically happens with live sources.
74 *
75 * The possible return values from a state change function such as
76 * gst_element_set_state(). Only @GST_STATE_CHANGE_FAILURE is a real failure.
77 */
78typedef enum {
79 GST_STATE_CHANGE_FAILURE = 0,
80 GST_STATE_CHANGE_SUCCESS = 1,
81 GST_STATE_CHANGE_ASYNC = 2,
82 GST_STATE_CHANGE_NO_PREROLL = 3
83} GstStateChangeReturn;
84
85#include <gst/gstconfig.h>
86#include <gst/gstobject.h>
87#include <gst/gstpad.h>
88#include <gst/gstbus.h>
89#include <gst/gstclock.h>
90#include <gst/gstelementfactory.h>
91#include <gst/gstplugin.h>
92#include <gst/gstpluginfeature.h>
93#include <gst/gstiterator.h>
94#include <gst/gstmessage.h>
95#include <gst/gstquery.h>
96#include <gst/gsttaglist.h>
97#include <gst/gstcontext.h>
98
99/* NOTE: this probably should be done with an #ifdef to decide
100 * whether to safe-cast or to just do the non-checking cast.
101 */
102
103/**
104 * GST_STATE:
105 * @elem: a #GstElement to return state for.
106 *
107 * This macro returns the current #GstState of the element.
108 */
109#define GST_STATE(elem) (GST_ELEMENT_CAST(elem)->current_state)
110
111/**
112 * GST_STATE_NEXT:
113 * @elem: a #GstElement to return the next state for.
114 *
115 * This macro returns the next #GstState of the element.
116 */
117#define GST_STATE_NEXT(elem) (GST_ELEMENT_CAST(elem)->next_state)
118
119/**
120 * GST_STATE_PENDING:
121 * @elem: a #GstElement to return the pending state for.
122 *
123 * This macro returns the currently pending #GstState of the element.
124 */
125#define GST_STATE_PENDING(elem) (GST_ELEMENT_CAST(elem)->pending_state)
126
127/**
128 * GST_STATE_TARGET:
129 * @elem: a #GstElement to return the target state for.
130 *
131 * This macro returns the target #GstState of the element.
132 */
133#define GST_STATE_TARGET(elem) (GST_ELEMENT_CAST(elem)->target_state)
134
135/**
136 * GST_STATE_RETURN:
137 * @elem: a #GstElement to return the last state result for.
138 *
139 * This macro returns the last #GstStateChangeReturn value.
140 */
141#define GST_STATE_RETURN(elem) (GST_ELEMENT_CAST(elem)->last_return)
142
143#define __GST_SIGN(val) ((val) < 0 ? -1 : ((val) > 0 ? 1 : 0))
144/**
145 * GST_STATE_GET_NEXT:
146 * @cur: A starting #GstState
147 * @pending: A target #GstState
148 *
149 * Given a current state @cur and a target state @pending, calculate the next (intermediate)
150 * #GstState.
151 */
152#define GST_STATE_GET_NEXT(cur,pending) ((GstState)((cur) + __GST_SIGN ((gint)(pending) - (gint)(cur))))
153/**
154 * GST_STATE_TRANSITION:
155 * @cur: A current state
156 * @next: A next state
157 *
158 * Given a current state @cur and a next state @next, calculate the associated
159 * #GstStateChange transition.
160 */
161#define GST_STATE_TRANSITION(cur,next) ((GstStateChange)(((cur)<<3)|(next)))
162/**
163 * GST_STATE_TRANSITION_CURRENT:
164 * @trans: A #GstStateChange
165 *
166 * Given a state transition @trans, extract the current #GstState.
167 */
168#define GST_STATE_TRANSITION_CURRENT(trans) ((GstState)((trans)>>3))
169/**
170 * GST_STATE_TRANSITION_NEXT:
171 * @trans: A #GstStateChange
172 *
173 * Given a state transition @trans, extract the next #GstState.
174 */
175#define GST_STATE_TRANSITION_NEXT(trans) ((GstState)((trans)&0x7))
176
177/**
178 * GstStateChange:
179 * @GST_STATE_CHANGE_NULL_TO_READY : state change from NULL to READY.
180 * * The element must check if the resources it needs are available. Device
181 * sinks and -sources typically try to probe the device to constrain their
182 * caps.
183 * * The element opens the device (in case feature need to be probed).
184 * @GST_STATE_CHANGE_READY_TO_PAUSED : state change from READY to PAUSED.
185 * * The element pads are activated in order to receive data in PAUSED.
186 * Streaming threads are started.
187 * * Some elements might need to return %GST_STATE_CHANGE_ASYNC and complete
188 * the state change when they have enough information. It is a requirement
189 * for sinks to return %GST_STATE_CHANGE_ASYNC and complete the state change
190 * when they receive the first buffer or %GST_EVENT_EOS (preroll).
191 * Sinks also block the dataflow when in PAUSED.
192 * * A pipeline resets the running_time to 0.
193 * * Live sources return %GST_STATE_CHANGE_NO_PREROLL and don't generate data.
194 * @GST_STATE_CHANGE_PAUSED_TO_PLAYING: state change from PAUSED to PLAYING.
195 * * Most elements ignore this state change.
196 * * The pipeline selects a #GstClock and distributes this to all the children
197 * before setting them to PLAYING. This means that it is only allowed to
198 * synchronize on the #GstClock in the PLAYING state.
199 * * The pipeline uses the #GstClock and the running_time to calculate the
200 * base_time. The base_time is distributed to all children when performing
201 * the state change.
202 * * Sink elements stop blocking on the preroll buffer or event and start
203 * rendering the data.
204 * * Sinks can post %GST_MESSAGE_EOS in the PLAYING state. It is not allowed
205 * to post %GST_MESSAGE_EOS when not in the PLAYING state.
206 * * While streaming in PAUSED or PLAYING elements can create and remove
207 * sometimes pads.
208 * * Live sources start generating data and return %GST_STATE_CHANGE_SUCCESS.
209 * @GST_STATE_CHANGE_PLAYING_TO_PAUSED: state change from PLAYING to PAUSED.
210 * * Most elements ignore this state change.
211 * * The pipeline calculates the running_time based on the last selected
212 * #GstClock and the base_time. It stores this information to continue
213 * playback when going back to the PLAYING state.
214 * * Sinks unblock any #GstClock wait calls.
215 * * When a sink does not have a pending buffer to play, it returns
216 * #GST_STATE_CHANGE_ASYNC from this state change and completes the state
217 * change when it receives a new buffer or an %GST_EVENT_EOS.
218 * * Any queued %GST_MESSAGE_EOS items are removed since they will be reposted
219 * when going back to the PLAYING state. The EOS messages are queued in
220 * #GstBin containers.
221 * * Live sources stop generating data and return %GST_STATE_CHANGE_NO_PREROLL.
222 * @GST_STATE_CHANGE_PAUSED_TO_READY : state change from PAUSED to READY.
223 * * Sinks unblock any waits in the preroll.
224 * * Elements unblock any waits on devices
225 * * Chain or get_range functions return %GST_FLOW_FLUSHING.
226 * * The element pads are deactivated so that streaming becomes impossible and
227 * all streaming threads are stopped.
228 * * The sink forgets all negotiated formats
229 * * Elements remove all sometimes pads
230 * @GST_STATE_CHANGE_READY_TO_NULL : state change from READY to NULL.
231 * * Elements close devices
232 * * Elements reset any internal state.
233 * @GST_STATE_CHANGE_NULL_TO_NULL : state change from NULL to NULL. (Since 1.14)
234 * @GST_STATE_CHANGE_READY_TO_READY : state change from READY to READY,
235 * This might happen when going to PAUSED asynchronously failed, in that case
236 * elements should make sure they are in a proper, coherent READY state. (Since 1.14)
237 * @GST_STATE_CHANGE_PAUSED_TO_PAUSED : state change from PAUSED to PAUSED.
238 * This might happen when elements were in PLAYING state and 'lost state',
239 * they should make sure to go back to real 'PAUSED' state (prerolling for example). (Since 1.14)
240 * @GST_STATE_CHANGE_PLAYING_TO_PLAYING : state change from PLAYING to PLAYING. (Since 1.14)
241 *
242 * These are the different state changes an element goes through.
243 * %GST_STATE_NULL &rArr; %GST_STATE_PLAYING is called an upwards state change
244 * and %GST_STATE_PLAYING &rArr; %GST_STATE_NULL a downwards state change.
245 */
246typedef enum /*< flags=0 >*/
247{
248 GST_STATE_CHANGE_NULL_TO_READY = (GST_STATE_NULL<<3) | GST_STATE_READY,
249 GST_STATE_CHANGE_READY_TO_PAUSED = (GST_STATE_READY<<3) | GST_STATE_PAUSED,
250 GST_STATE_CHANGE_PAUSED_TO_PLAYING = (GST_STATE_PAUSED<<3) | GST_STATE_PLAYING,
251 GST_STATE_CHANGE_PLAYING_TO_PAUSED = (GST_STATE_PLAYING<<3) | GST_STATE_PAUSED,
252 GST_STATE_CHANGE_PAUSED_TO_READY = (GST_STATE_PAUSED<<3) | GST_STATE_READY,
253 GST_STATE_CHANGE_READY_TO_NULL = (GST_STATE_READY<<3) | GST_STATE_NULL,
254 GST_STATE_CHANGE_NULL_TO_NULL = (GST_STATE_NULL<<3) | GST_STATE_NULL,
255 GST_STATE_CHANGE_READY_TO_READY = (GST_STATE_READY<<3) | GST_STATE_READY,
256 GST_STATE_CHANGE_PAUSED_TO_PAUSED = (GST_STATE_PAUSED<<3) | GST_STATE_PAUSED,
257 GST_STATE_CHANGE_PLAYING_TO_PLAYING = (GST_STATE_PLAYING<<3) | GST_STATE_PLAYING
258} GstStateChange;
259
260/**
261 * GstElementFlags:
262 * @GST_ELEMENT_FLAG_LOCKED_STATE: ignore state changes from parent
263 * @GST_ELEMENT_FLAG_SINK: the element is a sink
264 * @GST_ELEMENT_FLAG_SOURCE: the element is a source.
265 * @GST_ELEMENT_FLAG_PROVIDE_CLOCK: the element can provide a clock
266 * @GST_ELEMENT_FLAG_REQUIRE_CLOCK: the element requires a clock
267 * @GST_ELEMENT_FLAG_INDEXABLE: the element can use an index
268 * @GST_ELEMENT_FLAG_LAST: offset to define more flags
269 *
270 * The standard flags that an element may have.
271 */
272typedef enum
273{
274 GST_ELEMENT_FLAG_LOCKED_STATE = (GST_OBJECT_FLAG_LAST << 0),
275 GST_ELEMENT_FLAG_SINK = (GST_OBJECT_FLAG_LAST << 1),
276 GST_ELEMENT_FLAG_SOURCE = (GST_OBJECT_FLAG_LAST << 2),
277 GST_ELEMENT_FLAG_PROVIDE_CLOCK = (GST_OBJECT_FLAG_LAST << 3),
278 GST_ELEMENT_FLAG_REQUIRE_CLOCK = (GST_OBJECT_FLAG_LAST << 4),
279 GST_ELEMENT_FLAG_INDEXABLE = (GST_OBJECT_FLAG_LAST << 5),
280 /* padding */
281 GST_ELEMENT_FLAG_LAST = (GST_OBJECT_FLAG_LAST << 10)
282} GstElementFlags;
283
284/**
285 * GST_ELEMENT_IS_LOCKED_STATE:
286 * @elem: A #GstElement to query
287 *
288 * Check if the element is in the locked state and therefore will ignore state
289 * changes from its parent object.
290 */
291#define GST_ELEMENT_IS_LOCKED_STATE(elem) (GST_OBJECT_FLAG_IS_SET(elem,GST_ELEMENT_FLAG_LOCKED_STATE))
292
293/**
294 * GST_ELEMENT_NAME:
295 * @elem: A #GstElement to query
296 *
297 * Gets the name of this element. This is not thread-safe by default
298 * (i.e. you will have to make sure the object lock is taken yourself).
299 * If in doubt use gst_element_get_name() instead.
300 */
301#define GST_ELEMENT_NAME(elem) (GST_OBJECT_NAME(elem))
302
303/**
304 * GST_ELEMENT_PARENT:
305 * @elem: A #GstElement to query
306 *
307 * Get the parent object of this element. This is not thread-safe by default
308 * (i.e. you will have to make sure the object lock is taken yourself).
309 * If in doubt use gst_object_get_parent() instead.
310 */
311#define GST_ELEMENT_PARENT(elem) (GST_ELEMENT_CAST(GST_OBJECT_PARENT(elem)))
312
313/**
314 * GST_ELEMENT_BUS:
315 * @elem: A #GstElement to query
316 *
317 * Get the message bus of this element. This is not thread-safe by default
318 * (i.e. you will have to make sure the object lock is taken yourself).
319 * If in doubt use gst_element_get_bus() instead.
320 */
321#define GST_ELEMENT_BUS(elem) (GST_ELEMENT_CAST(elem)->bus)
322
323/**
324 * GST_ELEMENT_CLOCK:
325 * @elem: A #GstElement to query
326 *
327 * Get the clock of this element.This is not thread-safe by default
328 * (i.e. you will have to make sure it is safe yourself).
329 * If in doubt use gst_element_get_clock() instead.
330 */
331#define GST_ELEMENT_CLOCK(elem) (GST_ELEMENT_CAST(elem)->clock)
332
333/**
334 * GST_ELEMENT_PADS:
335 * @elem: A #GstElement to query
336 *
337 * Get the pads of this elements.
338 */
339#define GST_ELEMENT_PADS(elem) (GST_ELEMENT_CAST(elem)->pads)
340
341/**
342 * GST_ELEMENT_START_TIME:
343 * @elem: a #GstElement to return the start time for.
344 *
345 * This macro returns the start_time of the @elem. The start_time is the
346 * running_time of the pipeline when the element went to PAUSED.
347 */
348#define GST_ELEMENT_START_TIME(elem) (GST_ELEMENT_CAST(elem)->start_time)
349
350GST_API
351GstStructure *gst_make_element_message_details (const char *name, ...);
352
353#define GST_ELEMENT_MESSAGE_MAKE_DETAILS(args) gst_make_element_message_details args
354
355/**
356 * GST_ELEMENT_FLOW_ERROR:
357 * @el: the element that generates the error
358 * @flow_return: the GstFlowReturn leading to that ERROR message
359 *
360 * Utility function that elements can use in case they encountered a fatal
361 * data processing error due to wrong flow processing.
362 *
363 * Since: 1.10
364 */
365#define GST_ELEMENT_FLOW_ERROR(el,flow_return) \
366G_STMT_START { \
367 GST_ELEMENT_ERROR_WITH_DETAILS (el, STREAM, FAILED, \
368 ("Internal data stream error."), \
369 ("streaming stopped, reason %s (%d)", gst_flow_get_name (flow_return), flow_return), \
370 ("flow-return", G_TYPE_INT, flow_return, NULL));\
371} G_STMT_END
372
373/**
374 * GST_ELEMENT_ERROR_WITH_DETAILS:
375 * @el: the element that generates the error
376 * @domain: like CORE, LIBRARY, RESOURCE or STREAM (see #gstreamer-GstGError)
377 * @code: error code defined for that domain (see #gstreamer-GstGError)
378 * @text: the message to display (format string and args enclosed in
379 parentheses)
380 * @debug: debugging information for the message (format string and args
381 enclosed in parentheses)
382 * @args: optional name, type, value triplets, which will be stored
383 * in the associated GstStructure. NULL terminator required.
384 * Must be enclosed within parentheses.
385 *
386 * Utility function that elements can use in case they encountered a fatal
387 * data processing error. The pipeline will post an error message and the
388 * application will be requested to stop further media processing.
389 *
390 * Since: 1.10
391 */
392#define GST_ELEMENT_ERROR_WITH_DETAILS(el,domain,code,text,debug,args) \
393G_STMT_START { \
394 gchar *__txt = _gst_element_error_printf text; \
395 gchar *__dbg = _gst_element_error_printf debug; \
396 if (__txt) \
397 GST_WARNING_OBJECT (el, "error: %s", __txt); \
398 if (__dbg) \
399 GST_WARNING_OBJECT (el, "error: %s", __dbg); \
400 gst_element_message_full_with_details (GST_ELEMENT(el), \
401 GST_MESSAGE_ERROR, GST_ ## domain ## _ERROR, \
402 GST_ ## domain ## _ERROR_ ## code, __txt, __dbg, __FILE__, \
403 GST_FUNCTION, __LINE__, GST_ELEMENT_MESSAGE_MAKE_DETAILS(args)); \
404} G_STMT_END
405
406/**
407 * GST_ELEMENT_ERROR:
408 * @el: the element that generates the error
409 * @domain: like CORE, LIBRARY, RESOURCE or STREAM (see #gstreamer-GstGError)
410 * @code: error code defined for that domain (see #gstreamer-GstGError)
411 * @text: the message to display (format string and args enclosed in
412 parentheses)
413 * @debug: debugging information for the message (format string and args
414 enclosed in parentheses)
415 *
416 * Utility function that elements can use in case they encountered a fatal
417 * data processing error. The pipeline will post an error message and the
418 * application will be requested to stop further media processing.
419 */
420#define GST_ELEMENT_ERROR(el,domain,code,text,debug) \
421G_STMT_START { \
422 gchar *__txt = _gst_element_error_printf text; \
423 gchar *__dbg = _gst_element_error_printf debug; \
424 if (__txt) \
425 GST_WARNING_OBJECT (el, "error: %s", __txt); \
426 if (__dbg) \
427 GST_WARNING_OBJECT (el, "error: %s", __dbg); \
428 gst_element_message_full (GST_ELEMENT(el), \
429 GST_MESSAGE_ERROR, GST_ ## domain ## _ERROR, \
430 GST_ ## domain ## _ERROR_ ## code, __txt, __dbg, __FILE__, \
431 GST_FUNCTION, __LINE__); \
432} G_STMT_END
433
434/**
435 * GST_ELEMENT_WARNING_WITH_DETAILS:
436 * @el: the element that generates the warning
437 * @domain: like CORE, LIBRARY, RESOURCE or STREAM (see #gstreamer-GstGError)
438 * @code: error code defined for that domain (see #gstreamer-GstGError)
439 * @text: the message to display (format string and args enclosed in
440 parentheses)
441 * @debug: debugging information for the message (format string and args
442 enclosed in parentheses)
443 * @args: optional name, type, value triplets, which will be stored
444 * in the associated GstStructure. NULL terminator required.
445 * Must be enclosed within parentheses.
446 *
447 * Utility function that elements can use in case they encountered a non-fatal
448 * data processing problem. The pipeline will post a warning message and the
449 * application will be informed.
450 *
451 * Since: 1.10
452 */
453#define GST_ELEMENT_WARNING_WITH_DETAILS(el, domain, code, text, debug, args)\
454G_STMT_START { \
455 gchar *__txt = _gst_element_error_printf text; \
456 gchar *__dbg = _gst_element_error_printf debug; \
457 if (__txt) \
458 GST_WARNING_OBJECT (el, "warning: %s", __txt); \
459 if (__dbg) \
460 GST_WARNING_OBJECT (el, "warning: %s", __dbg); \
461 gst_element_message_full_with_details (GST_ELEMENT(el), \
462 GST_MESSAGE_WARNING, GST_ ## domain ## _ERROR, \
463 GST_ ## domain ## _ERROR_ ## code, __txt, __dbg, __FILE__, \
464 GST_FUNCTION, __LINE__, GST_ELEMENT_MESSAGE_MAKE_DETAILS(args)); \
465} G_STMT_END
466
467/**
468 * GST_ELEMENT_WARNING:
469 * @el: the element that generates the warning
470 * @domain: like CORE, LIBRARY, RESOURCE or STREAM (see #gstreamer-GstGError)
471 * @code: error code defined for that domain (see #gstreamer-GstGError)
472 * @text: the message to display (format string and args enclosed in
473 parentheses)
474 * @debug: debugging information for the message (format string and args
475 enclosed in parentheses)
476 *
477 * Utility function that elements can use in case they encountered a non-fatal
478 * data processing problem. The pipeline will post a warning message and the
479 * application will be informed.
480 */
481#define GST_ELEMENT_WARNING(el, domain, code, text, debug) \
482G_STMT_START { \
483 gchar *__txt = _gst_element_error_printf text; \
484 gchar *__dbg = _gst_element_error_printf debug; \
485 if (__txt) \
486 GST_WARNING_OBJECT (el, "warning: %s", __txt); \
487 if (__dbg) \
488 GST_WARNING_OBJECT (el, "warning: %s", __dbg); \
489 gst_element_message_full (GST_ELEMENT(el), \
490 GST_MESSAGE_WARNING, GST_ ## domain ## _ERROR, \
491 GST_ ## domain ## _ERROR_ ## code, __txt, __dbg, __FILE__, \
492 GST_FUNCTION, __LINE__); \
493} G_STMT_END
494
495/**
496 * GST_ELEMENT_INFO_WITH_DETAILS:
497 * @el: the element that generates the information
498 * @domain: like CORE, LIBRARY, RESOURCE or STREAM (see #gstreamer-GstGError)
499 * @code: error code defined for that domain (see #gstreamer-GstGError)
500 * @text: the message to display (format string and args enclosed in
501 parentheses)
502 * @debug: debugging information for the message (format string and args
503 enclosed in parentheses)
504 * @args: optional name, type, value triplets, which will be stored
505 * in the associated GstStructure. NULL terminator required.
506 * Must be enclosed within parentheses.
507 *
508 * Utility function that elements can use in case they want to inform
509 * the application of something noteworthy that is not an error.
510 * The pipeline will post a info message and the
511 * application will be informed.
512 * Optional name, type, value triplets may be supplied, and will be stored
513 * in the associated GstStructure. NULL terminator required.
514 *
515 * Since: 1.10
516 */
517#define GST_ELEMENT_INFO_WITH_DETAILS(el, domain, code, text, debug, args) \
518G_STMT_START { \
519 gchar *__txt = _gst_element_error_printf text; \
520 gchar *__dbg = _gst_element_error_printf debug; \
521 if (__txt) \
522 GST_INFO_OBJECT (el, "info: %s", __txt); \
523 if (__dbg) \
524 GST_INFO_OBJECT (el, "info: %s", __dbg); \
525 gst_element_message_full_with_details (GST_ELEMENT(el), \
526 GST_MESSAGE_INFO, GST_ ## domain ## _ERROR, \
527 GST_ ## domain ## _ERROR_ ## code, __txt, __dbg, __FILE__, \
528 GST_FUNCTION, __LINE__, GST_ELEMENT_MESSAGE_MAKE_DETAILS(args)); \
529} G_STMT_END
530
531/**
532 * GST_ELEMENT_INFO:
533 * @el: the element that generates the information
534 * @domain: like CORE, LIBRARY, RESOURCE or STREAM (see #gstreamer-GstGError)
535 * @code: error code defined for that domain (see #gstreamer-GstGError)
536 * @text: the message to display (format string and args enclosed in
537 parentheses)
538 * @debug: debugging information for the message (format string and args
539 enclosed in parentheses)
540 *
541 * Utility function that elements can use in case they want to inform
542 * the application of something noteworthy that is not an error.
543 * The pipeline will post a info message and the
544 * application will be informed.
545 */
546#define GST_ELEMENT_INFO(el, domain, code, text, debug) \
547G_STMT_START { \
548 gchar *__txt = _gst_element_error_printf text; \
549 gchar *__dbg = _gst_element_error_printf debug; \
550 if (__txt) \
551 GST_INFO_OBJECT (el, "info: %s", __txt); \
552 if (__dbg) \
553 GST_INFO_OBJECT (el, "info: %s", __dbg); \
554 gst_element_message_full (GST_ELEMENT(el), \
555 GST_MESSAGE_INFO, GST_ ## domain ## _ERROR, \
556 GST_ ## domain ## _ERROR_ ## code, __txt, __dbg, __FILE__, \
557 GST_FUNCTION, __LINE__); \
558} G_STMT_END
559
560/* the state change mutexes and conds */
561/**
562 * GST_STATE_GET_LOCK:
563 * @elem: a #GstElement
564 *
565 * Get a reference to the state lock of @elem.
566 * This lock is used by the core. It is taken while getting or setting
567 * the state, during state changes, and while finalizing.
568 */
569#define GST_STATE_GET_LOCK(elem) (&(GST_ELEMENT_CAST(elem)->state_lock))
570/**
571 * GST_STATE_GET_COND:
572 * @elem: a #GstElement
573 *
574 * Get the conditional used to signal the completion of a state change.
575 */
576#define GST_STATE_GET_COND(elem) (&GST_ELEMENT_CAST(elem)->state_cond)
577
578#define GST_STATE_LOCK(elem) g_rec_mutex_lock(GST_STATE_GET_LOCK(elem))
579#define GST_STATE_TRYLOCK(elem) g_rec_mutex_trylock(GST_STATE_GET_LOCK(elem))
580#define GST_STATE_UNLOCK(elem) g_rec_mutex_unlock(GST_STATE_GET_LOCK(elem))
581#define GST_STATE_WAIT(elem) g_cond_wait (GST_STATE_GET_COND (elem), \
582 GST_OBJECT_GET_LOCK (elem))
583#define GST_STATE_WAIT_UNTIL(elem, end_time) g_cond_wait_until (GST_STATE_GET_COND (elem), \
584 GST_OBJECT_GET_LOCK (elem), end_time)
585#define GST_STATE_SIGNAL(elem) g_cond_signal (GST_STATE_GET_COND (elem));
586#define GST_STATE_BROADCAST(elem) g_cond_broadcast (GST_STATE_GET_COND (elem));
587
588/**
589 * GstElement:
590 * @state_lock: Used to serialize execution of gst_element_set_state()
591 * @state_cond: Used to signal completion of a state change
592 * @state_cookie: Used to detect concurrent execution of
593 * gst_element_set_state() and gst_element_get_state()
594 * @target_state: the target state of an element as set by the application
595 * @current_state: the current state of an element
596 * @next_state: the next state of an element, can be #GST_STATE_VOID_PENDING if
597 * the element is in the correct state.
598 * @pending_state: the final state the element should go to, can be
599 * #GST_STATE_VOID_PENDING if the element is in the correct state
600 * @last_return: the last return value of an element state change
601 * @bus: the bus of the element. This bus is provided to the element by the
602 * parent element or the application. A #GstPipeline has a bus of its own.
603 * @clock: the clock of the element. This clock is usually provided to the
604 * element by the toplevel #GstPipeline.
605 * @base_time: the time of the clock right before the element is set to
606 * PLAYING. Subtracting @base_time from the current clock time in the PLAYING
607 * state will yield the running_time against the clock.
608 * @start_time: the running_time of the last PAUSED state
609 * @numpads: number of pads of the element, includes both source and sink pads.
610 * @pads: (element-type Gst.Pad): list of pads
611 * @numsrcpads: number of source pads of the element.
612 * @srcpads: (element-type Gst.Pad): list of source pads
613 * @numsinkpads: number of sink pads of the element.
614 * @sinkpads: (element-type Gst.Pad): list of sink pads
615 * @pads_cookie: updated whenever the a pad is added or removed
616 * @contexts: (element-type Gst.Context): list of contexts
617 *
618 * GStreamer element abstract base class.
619 */
620struct _GstElement
621{
622 GstObject object;
623
624 /*< public >*/ /* with LOCK */
625 GRecMutex state_lock;
626
627 /* element state */
628 GCond state_cond;
629 guint32 state_cookie;
630 GstState target_state;
631 GstState current_state;
632 GstState next_state;
633 GstState pending_state;
634 GstStateChangeReturn last_return;
635
636 GstBus *bus;
637
638 /* allocated clock */
639 GstClock *clock;
640 GstClockTimeDiff base_time; /* NULL/READY: 0 - PAUSED: current time - PLAYING: difference to clock */
641 GstClockTime start_time;
642
643 /* element pads, these lists can only be iterated while holding
644 * the LOCK or checking the cookie after each LOCK. */
645 guint16 numpads;
646 GList *pads;
647 guint16 numsrcpads;
648 GList *srcpads;
649 guint16 numsinkpads;
650 GList *sinkpads;
651 guint32 pads_cookie;
652
653 /* with object LOCK */
654 GList *contexts;
655
656 /*< private >*/
657 gpointer _gst_reserved[GST_PADDING-1];
658};
659
660/**
661 * GstElementClass:
662 * @parent_class: the parent class structure
663 * @metadata: metadata for elements of this class
664 * @elementfactory: the #GstElementFactory that creates these elements
665 * @padtemplates: a #GList of #GstPadTemplate
666 * @numpadtemplates: the number of padtemplates
667 * @pad_templ_cookie: changed whenever the padtemplates change
668 * @request_new_pad: called when a new pad is requested
669 * @release_pad: called when a request pad is to be released
670 * @get_state: get the state of the element
671 * @set_state: set a new state on the element
672 * @change_state: called by @set_state to perform an incremental state change
673 * @set_bus: set a #GstBus on the element
674 * @provide_clock: gets the #GstClock provided by the element
675 * @set_clock: set the #GstClock on the element
676 * @send_event: send a #GstEvent to the element
677 * @query: perform a #GstQuery on the element
678 * @state_changed: called immediately after a new state was set.
679 * @post_message: called when a message is posted on the element. Chain up to
680 * the parent class' handler to have it posted on the bus.
681 * @set_context: set a #GstContext on the element
682 *
683 * GStreamer element class. Override the vmethods to implement the element
684 * functionality.
685 */
686struct _GstElementClass
687{
688 GstObjectClass parent_class;
689
690 /*< public >*/
691 /* the element metadata */
692 gpointer metadata;
693
694 /* factory that the element was created from */
695 GstElementFactory *elementfactory;
696
697 /* templates for our pads */
698 GList *padtemplates;
699 gint numpadtemplates;
700 guint32 pad_templ_cookie;
701
702 /*< private >*/
703 /* signal callbacks */
704 void (*pad_added) (GstElement *element, GstPad *pad);
705 void (*pad_removed) (GstElement *element, GstPad *pad);
706 void (*no_more_pads) (GstElement *element);
707
708 /*< public >*/
709 /* virtual methods for subclasses */
710
711 /* request/release pads */
712 /* FIXME 2.0 harmonize naming with gst_element_request_pad */
713 GstPad* (*request_new_pad) (GstElement *element, GstPadTemplate *templ,
714 const gchar* name, const GstCaps *caps);
715
716 void (*release_pad) (GstElement *element, GstPad *pad);
717
718 /* state changes */
719 GstStateChangeReturn (*get_state) (GstElement * element, GstState * state,
720 GstState * pending, GstClockTime timeout);
721 GstStateChangeReturn (*set_state) (GstElement *element, GstState state);
722 GstStateChangeReturn (*change_state) (GstElement *element, GstStateChange transition);
723 void (*state_changed) (GstElement *element, GstState oldstate,
724 GstState newstate, GstState pending);
725
726 /* bus */
727 void (*set_bus) (GstElement * element, GstBus * bus);
728
729 /* set/get clocks */
730 GstClock* (*provide_clock) (GstElement *element);
731 gboolean (*set_clock) (GstElement *element, GstClock *clock);
732
733 /* query functions */
734 gboolean (*send_event) (GstElement *element, GstEvent *event);
735
736 gboolean (*query) (GstElement *element, GstQuery *query);
737
738 gboolean (*post_message) (GstElement *element, GstMessage *message);
739
740 void (*set_context) (GstElement *element, GstContext *context);
741
742 /*< private >*/
743 gpointer _gst_reserved[GST_PADDING_LARGE-2];
744};
745
746/* element class pad templates */
747
748GST_API
749void gst_element_class_add_pad_template (GstElementClass *klass, GstPadTemplate *templ);
750
751GST_API
752void gst_element_class_add_static_pad_template (GstElementClass *klass, GstStaticPadTemplate *static_templ);
753
754GST_API
755void gst_element_class_add_static_pad_template_with_gtype (GstElementClass *klass,
756 GstStaticPadTemplate *static_templ,
757 GType pad_type);
758
759GST_API
760GstPadTemplate* gst_element_class_get_pad_template (GstElementClass *element_class, const gchar *name);
761
762GST_API
763GList* gst_element_class_get_pad_template_list (GstElementClass *element_class);
764
765/* element class meta data */
766
767GST_API
768void gst_element_class_set_metadata (GstElementClass *klass,
769 const gchar *longname,
770 const gchar *classification,
771 const gchar *description,
772 const gchar *author);
773GST_API
774void gst_element_class_set_static_metadata (GstElementClass *klass,
775 const gchar *longname,
776 const gchar *classification,
777 const gchar *description,
778 const gchar *author);
779GST_API
780void gst_element_class_add_metadata (GstElementClass * klass,
781 const gchar * key, const gchar * value);
782GST_API
783void gst_element_class_add_static_metadata (GstElementClass * klass,
784 const gchar * key, const gchar * value);
785GST_API
786const gchar * gst_element_class_get_metadata (GstElementClass * klass,
787 const gchar * key);
788
789
790/* element instance */
791
792GST_API
793GType gst_element_get_type (void);
794
795/* basic name and parentage stuff from GstObject */
796
797/**
798 * gst_element_get_name:
799 * @elem: a #GstElement to get the name of @elem.
800 *
801 * Returns a copy of the name of @elem.
802 * Caller should g_free() the return value after usage.
803 * For a nameless element, this returns %NULL, which you can safely g_free()
804 * as well.
805 *
806 * Returns: (transfer full) (nullable): the name of @elem. g_free()
807 * after usage. MT safe.
808 *
809 */
810#define gst_element_get_name(elem) gst_object_get_name(GST_OBJECT_CAST(elem))
811
812/**
813 * gst_element_set_name:
814 * @elem: a #GstElement to set the name of.
815 * @name: the new name
816 *
817 * Sets the name of the element, getting rid of the old name if there was one.
818 */
819#define gst_element_set_name(elem,name) gst_object_set_name(GST_OBJECT_CAST(elem),name)
820
821/**
822 * gst_element_get_parent:
823 * @elem: a #GstElement to get the parent of.
824 *
825 * Get the parent of an element.
826 *
827 * Returns: (transfer full): the parent of an element.
828 */
829#define gst_element_get_parent(elem) gst_object_get_parent(GST_OBJECT_CAST(elem))
830
831/**
832 * gst_element_set_parent:
833 * @elem: a #GstElement to set the parent of.
834 * @parent: the new parent #GstObject of the element.
835 *
836 * Sets the parent of an element.
837 */
838#define gst_element_set_parent(elem,parent) gst_object_set_parent(GST_OBJECT_CAST(elem),parent)
839
840/* clocking */
841
842GST_API
843GstClock* gst_element_provide_clock (GstElement *element);
844
845GST_API
846GstClock* gst_element_get_clock (GstElement *element);
847
848GST_API
849gboolean gst_element_set_clock (GstElement *element, GstClock *clock);
850
851GST_API
852void gst_element_set_base_time (GstElement *element, GstClockTime time);
853
854GST_API
855GstClockTime gst_element_get_base_time (GstElement *element);
856
857GST_API
858void gst_element_set_start_time (GstElement *element, GstClockTime time);
859
860GST_API
861GstClockTime gst_element_get_start_time (GstElement *element);
862
863/* bus */
864
865GST_API
866void gst_element_set_bus (GstElement * element, GstBus * bus);
867
868GST_API
869GstBus * gst_element_get_bus (GstElement * element);
870
871/* context */
872
873GST_API
874void gst_element_set_context (GstElement * element, GstContext * context);
875
876GST_API
877GList * gst_element_get_contexts (GstElement * element);
878
879GST_API
880GstContext * gst_element_get_context (GstElement * element, const gchar * context_type);
881
882GST_API
883GstContext * gst_element_get_context_unlocked (GstElement * element, const gchar * context_type);
884
885/* pad management */
886
887GST_API
888gboolean gst_element_add_pad (GstElement *element, GstPad *pad);
889
890GST_API
891gboolean gst_element_remove_pad (GstElement *element, GstPad *pad);
892
893GST_API
894void gst_element_no_more_pads (GstElement *element);
895
896GST_API
897GstPad* gst_element_get_static_pad (GstElement *element, const gchar *name);
898
899GST_API
900GstPad* gst_element_get_request_pad (GstElement *element, const gchar *name);
901
902GST_API
903GstPad* gst_element_request_pad (GstElement *element, GstPadTemplate *templ,
904 const gchar * name, const GstCaps *caps);
905GST_API
906void gst_element_release_request_pad (GstElement *element, GstPad *pad);
907
908GST_API
909GstIterator * gst_element_iterate_pads (GstElement * element);
910
911GST_API
912GstIterator * gst_element_iterate_src_pads (GstElement * element);
913
914GST_API
915GstIterator * gst_element_iterate_sink_pads (GstElement * element);
916
917/**
918 * GstElementForeachPadFunc:
919 * @element: the #GstElement
920 * @pad: a #GstPad
921 * @user_data: user data passed to the foreach function
922 *
923 * Function called for each pad when using gst_element_foreach_sink_pad(),
924 * gst_element_foreach_src_pad(), or gst_element_foreach_pad().
925 *
926 * Returns: %FALSE to stop iterating pads, %TRUE to continue
927 *
928 * Since: 1.14
929 */
930typedef gboolean (*GstElementForeachPadFunc) (GstElement * element,
931 GstPad * pad,
932 gpointer user_data);
933
934GST_API
935gboolean gst_element_foreach_sink_pad (GstElement * element,
936 GstElementForeachPadFunc func,
937 gpointer user_data);
938GST_API
939gboolean gst_element_foreach_src_pad (GstElement * element,
940 GstElementForeachPadFunc func,
941 gpointer user_data);
942GST_API
943gboolean gst_element_foreach_pad (GstElement * element,
944 GstElementForeachPadFunc func,
945 gpointer user_data);
946/* event/query/format stuff */
947
948GST_API
949gboolean gst_element_send_event (GstElement *element, GstEvent *event);
950
951GST_API
952gboolean gst_element_seek (GstElement *element, gdouble rate,
953 GstFormat format, GstSeekFlags flags,
954 GstSeekType start_type, gint64 start,
955 GstSeekType stop_type, gint64 stop);
956GST_API
957gboolean gst_element_query (GstElement *element, GstQuery *query);
958
959/* messages */
960
961GST_API
962gboolean gst_element_post_message (GstElement * element, GstMessage * message);
963
964/* error handling */
965/* gcc versions < 3.3 warn about NULL being passed as format to printf */
966#if (!defined(__GNUC__) || (__GNUC__ < 3) || (__GNUC__ == 3 && __GNUC_MINOR__ < 3))
967GST_API
968gchar * _gst_element_error_printf (const gchar *format, ...);
969#else
970GST_API
971gchar * _gst_element_error_printf (const gchar *format, ...) G_GNUC_PRINTF (1, 2);
972#endif
973
974GST_API
975void gst_element_message_full (GstElement * element, GstMessageType type,
976 GQuark domain, gint code, gchar * text,
977 gchar * debug, const gchar * file,
978 const gchar * function, gint line);
979GST_API
980void gst_element_message_full_with_details (GstElement * element, GstMessageType type,
981 GQuark domain, gint code, gchar * text,
982 gchar * debug, const gchar * file,
983 const gchar * function, gint line,
984 GstStructure * structure);
985
986/* state management */
987
988GST_API
989gboolean gst_element_is_locked_state (GstElement *element);
990
991GST_API
992gboolean gst_element_set_locked_state (GstElement *element, gboolean locked_state);
993
994GST_API
995gboolean gst_element_sync_state_with_parent (GstElement *element);
996
997GST_API
998GstStateChangeReturn gst_element_get_state (GstElement * element,
999 GstState * state,
1000 GstState * pending,
1001 GstClockTime timeout);
1002GST_API
1003GstStateChangeReturn gst_element_set_state (GstElement *element, GstState state);
1004
1005GST_API
1006void gst_element_abort_state (GstElement * element);
1007
1008GST_API
1009GstStateChangeReturn gst_element_change_state (GstElement * element,
1010 GstStateChange transition);
1011
1012GST_API
1013GstStateChangeReturn gst_element_continue_state (GstElement * element,
1014 GstStateChangeReturn ret);
1015GST_API
1016void gst_element_lost_state (GstElement * element);
1017
1018
1019typedef void (*GstElementCallAsyncFunc) (GstElement * element,
1020 gpointer user_data);
1021GST_API
1022void gst_element_call_async (GstElement * element,
1023 GstElementCallAsyncFunc func, gpointer user_data,
1024 GDestroyNotify destroy_notify);
1025
1026/* factory management */
1027
1028GST_API
1029GstElementFactory* gst_element_get_factory (GstElement *element);
1030
1031/* utility functions */
1032
1033GST_API
1034gulong gst_element_add_property_notify_watch (GstElement * element,
1035 const gchar * property_name,
1036 gboolean include_value);
1037GST_API
1038gulong gst_element_add_property_deep_notify_watch (GstElement * element,
1039 const gchar * property_name,
1040 gboolean include_value);
1041GST_API
1042void gst_element_remove_property_notify_watch (GstElement * element,
1043 gulong watch_id);
1044
1045GST_API
1046GstPadTemplate* gst_element_get_pad_template (GstElement *element, const gchar *name);
1047
1048GST_API
1049GList* gst_element_get_pad_template_list (GstElement *element);
1050GST_API
1051const gchar * gst_element_get_metadata (GstElement * element, const gchar * key);
1052
1053#ifdef G_DEFINE_AUTOPTR_CLEANUP_FUNC
1054G_DEFINE_AUTOPTR_CLEANUP_FUNC(GstElement, gst_object_unref)
1055#endif
1056
1057G_END_DECLS
1058
1059#endif /* __GST_ELEMENT_H__ */
1060