gstelement.h 28.2 KB
Newer Older
1 2
/* GStreamer
 * 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
Erik Walthinsen's avatar
Erik Walthinsen committed
6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */


#ifndef __GST_ELEMENT_H__
#define __GST_ELEMENT_H__

Wim Taymans's avatar
Wim Taymans committed
27 28 29 30
/* gstelement.h and gstelementfactory.h include eachother */
typedef struct _GstElement GstElement;
typedef struct _GstElementClass GstElementClass;

31
/* gstmessage.h needs State */
Wim Taymans's avatar
Wim Taymans committed
32 33 34 35 36 37 38 39
/**
 * GstState:
 * @GST_STATE_VOID_PENDING     : no pending state.
 * @GST_STATE_NULL             : the NULL state or initial state of an element
 * @GST_STATE_READY            : the element is ready to go to PAUSED
 * @GST_STATE_PAUSED           : the element is PAUSED
 * @GST_STATE_PLAYING          : the element is PLAYING
 *
40
 * The posible states an element can be in.
Wim Taymans's avatar
Wim Taymans committed
41
 */
Wim Taymans's avatar
Wim Taymans committed
42
typedef enum {
43
  GST_STATE_VOID_PENDING        = 0,
44 45 46 47 48
  GST_STATE_NULL                = 1,
  GST_STATE_READY               = 2,
  GST_STATE_PAUSED              = 3,
  GST_STATE_PLAYING             = 4
} GstState;
Wim Taymans's avatar
Wim Taymans committed
49 50


51
#include <gst/gstconfig.h>
Erik Walthinsen's avatar
Erik Walthinsen committed
52 53
#include <gst/gstobject.h>
#include <gst/gstpad.h>
Wim Taymans's avatar
Wim Taymans committed
54
#include <gst/gstbus.h>
55
#include <gst/gstclock.h>
56
#include <gst/gstelementfactory.h>
57
#include <gst/gstplugin.h>
58
#include <gst/gstpluginfeature.h>
Wim Taymans's avatar
Wim Taymans committed
59
#include <gst/gstindex.h>
60
#include <gst/gstindexfactory.h>
61
#include <gst/gstiterator.h>
Wim Taymans's avatar
Wim Taymans committed
62
#include <gst/gstmessage.h>
63
#include <gst/gsttaglist.h>
Erik Walthinsen's avatar
Erik Walthinsen committed
64

65 66
G_BEGIN_DECLS

Wim Taymans's avatar
Wim Taymans committed
67 68 69 70 71 72 73
#define GST_TYPE_ELEMENT                (gst_element_get_type ())
#define GST_IS_ELEMENT(obj)             (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GST_TYPE_ELEMENT))
#define GST_IS_ELEMENT_CLASS(klass)     (G_TYPE_CHECK_CLASS_TYPE ((klass), GST_TYPE_ELEMENT))
#define GST_ELEMENT_GET_CLASS(obj)      (G_TYPE_INSTANCE_GET_CLASS ((obj), GST_TYPE_ELEMENT, GstElementClass))
#define GST_ELEMENT(obj)                (G_TYPE_CHECK_INSTANCE_CAST ((obj), GST_TYPE_ELEMENT, GstElement))
#define GST_ELEMENT_CLASS(klass)        (G_TYPE_CHECK_CLASS_CAST ((klass), GST_TYPE_ELEMENT, GstElementClass))
#define GST_ELEMENT_CAST(obj)           ((GstElement*)(obj))
74

Thomas Vander Stichele's avatar
Thomas Vander Stichele committed
75 76 77 78 79
/**
 * GstStateChangeReturn:
 * @GST_STATE_CHANGE_FAILURE   : the state change failed
 * @GST_STATE_CHANGE_SUCCESS   : the state change succeeded
 * @GST_STATE_CHANGE_ASYNC     : the state change will happen asynchronously
Thomas Vander Stichele's avatar
Thomas Vander Stichele committed
80 81 82
 * @GST_STATE_CHANGE_NO_PREROLL: the state change succeeded but the element
 *                               cannot produce data in PAUSED. This typically
 *                               happens with live sources.
83
 *
84 85
 * The possible return values from a state change function. Only
 * @GST_STATE_CHANGE_FAILURE is a real failure.
Thomas Vander Stichele's avatar
Thomas Vander Stichele committed
86
 */
Wim Taymans's avatar
Wim Taymans committed
87
typedef enum {
88 89 90 91 92
  GST_STATE_CHANGE_FAILURE             = 0,
  GST_STATE_CHANGE_SUCCESS             = 1,
  GST_STATE_CHANGE_ASYNC               = 2,
  GST_STATE_CHANGE_NO_PREROLL          = 3
} GstStateChangeReturn;
Wim Taymans's avatar
Wim Taymans committed
93

94
/* NOTE: this probably should be done with an #ifdef to decide
95 96
 * whether to safe-cast or to just do the non-checking cast.
 */
97 98 99

/**
 * GST_STATE:
100
 * @elem: a #GstElement to return state for.
101
 *
102
 * This macro returns the current #GstState of the element.
103
 */
Wim Taymans's avatar
Wim Taymans committed
104
#define GST_STATE(elem)                 (GST_ELEMENT_CAST(elem)->current_state)
105

106 107
/**
 * GST_STATE_NEXT:
108
 * @elem: a #GstElement to return the next state for.
109
 *
110
 * This macro returns the next #GstState of the element.
111
 */
Wim Taymans's avatar
Wim Taymans committed
112
#define GST_STATE_NEXT(elem)            (GST_ELEMENT_CAST(elem)->next_state)
113

114 115
/**
 * GST_STATE_PENDING:
116
 * @elem: a #GstElement to return the pending state for.
117
 *
118
 * This macro returns the currently pending #GstState of the element.
119
 */
Wim Taymans's avatar
Wim Taymans committed
120
#define GST_STATE_PENDING(elem)         (GST_ELEMENT_CAST(elem)->pending_state)
121

122 123 124 125 126 127 128 129
/**
 * GST_STATE_TARGET:
 * @elem: a #GstElement to return the target state for.
 *
 * This macro returns the target #GstState of the element.
 *
 * Since: 0.10.13
 */
Wim Taymans's avatar
Wim Taymans committed
130
#define GST_STATE_TARGET(elem)          (GST_ELEMENT_CAST(elem)->abidata.ABI.target_state)
131

132 133
/**
 * GST_STATE_RETURN:
134
 * @elem: a #GstElement to return the last state result for.
135
 *
136
 * This macro returns the last #GstStateChangeReturn value.
137
 */
Wim Taymans's avatar
Wim Taymans committed
138
#define GST_STATE_RETURN(elem)          (GST_ELEMENT_CAST(elem)->last_return)
139

Wim Taymans's avatar
Wim Taymans committed
140
#define __GST_SIGN(val)                 ((val) < 0 ? -1 : ((val) > 0 ? 1 : 0))
Wim Taymans's avatar
Wim Taymans committed
141 142
/**
 * GST_STATE_GET_NEXT:
143 144
 * @cur: A starting #GstState
 * @pending: A target #GstState
Wim Taymans's avatar
Wim Taymans committed
145
 *
146 147
 * Given a current state @cur and a target state @pending, calculate the next (intermediate)
 * #GstState.
Wim Taymans's avatar
Wim Taymans committed
148
 */
Wim Taymans's avatar
Wim Taymans committed
149
#define GST_STATE_GET_NEXT(cur,pending)         ((cur) + __GST_SIGN ((gint)(pending) - (gint)(cur)))
Wim Taymans's avatar
Wim Taymans committed
150 151 152 153 154
/**
 * GST_STATE_TRANSITION:
 * @cur: A current state
 * @next: A next state
 *
155
 * Given a current state @cur and a next state @next, calculate the associated
156
 * #GstStateChange transition.
Wim Taymans's avatar
Wim Taymans committed
157
 */
Wim Taymans's avatar
Wim Taymans committed
158
#define GST_STATE_TRANSITION(cur,next)          ((GstStateChange)(((cur)<<3)|(next)))
Wim Taymans's avatar
Wim Taymans committed
159 160
/**
 * GST_STATE_TRANSITION_CURRENT:
161
 * @trans: A #GstStateChange
Wim Taymans's avatar
Wim Taymans committed
162
 *
163
 * Given a state transition @trans, extract the current #GstState.
Wim Taymans's avatar
Wim Taymans committed
164
 */
Wim Taymans's avatar
Wim Taymans committed
165
#define GST_STATE_TRANSITION_CURRENT(trans)     ((GstState)((trans)>>3))
Wim Taymans's avatar
Wim Taymans committed
166 167
/**
 * GST_STATE_TRANSITION_NEXT:
168
 * @trans: A #GstStateChange
Wim Taymans's avatar
Wim Taymans committed
169
 *
170
 * Given a state transition @trans, extract the next #GstState.
Wim Taymans's avatar
Wim Taymans committed
171
 */
Wim Taymans's avatar
Wim Taymans committed
172
#define GST_STATE_TRANSITION_NEXT(trans)        ((GstState)((trans)&0x7))
173

Thomas Vander Stichele's avatar
Thomas Vander Stichele committed
174 175 176 177 178 179 180 181
/**
 * GstStateChange:
 * @GST_STATE_CHANGE_NULL_TO_READY    : state change from NULL to READY
 * @GST_STATE_CHANGE_READY_TO_PAUSED  : state change from READY to PAUSED
 * @GST_STATE_CHANGE_PAUSED_TO_PLAYING: state change from PAUSED to PLAYING
 * @GST_STATE_CHANGE_PLAYING_TO_PAUSED: state change from PLAYING to PAUSED
 * @GST_STATE_CHANGE_PAUSED_TO_READY  : state change from PAUSED to READY
 * @GST_STATE_CHANGE_READY_TO_NULL    : state change from READY to NULL
Wim Taymans's avatar
Wim Taymans committed
182 183 184
 *
 * The different (interesting) state changes that are passed to the
 * state change functions of elements.
Thomas Vander Stichele's avatar
Thomas Vander Stichele committed
185
 */
186
typedef enum /*< flags=0 >*/
187
{
Wim Taymans's avatar
Wim Taymans committed
188 189 190 191 192 193
  GST_STATE_CHANGE_NULL_TO_READY        = (GST_STATE_NULL<<3) | GST_STATE_READY,
  GST_STATE_CHANGE_READY_TO_PAUSED      = (GST_STATE_READY<<3) | GST_STATE_PAUSED,
  GST_STATE_CHANGE_PAUSED_TO_PLAYING    = (GST_STATE_PAUSED<<3) | GST_STATE_PLAYING,
  GST_STATE_CHANGE_PLAYING_TO_PAUSED    = (GST_STATE_PLAYING<<3) | GST_STATE_PAUSED,
  GST_STATE_CHANGE_PAUSED_TO_READY      = (GST_STATE_PAUSED<<3) | GST_STATE_READY,
  GST_STATE_CHANGE_READY_TO_NULL        = (GST_STATE_READY<<3) | GST_STATE_NULL
194
} GstStateChange;
195

196 197 198 199 200 201 202 203 204 205
/**
 * GstElementFlags:
 * @GST_ELEMENT_LOCKED_STATE: ignore state changes from parent
 * @GST_ELEMENT_IS_SINK: the element is a sink
 * @GST_ELEMENT_UNPARENTING: Child is being removed from the parent bin.
 *  gst_bin_remove() on a child already being removed immediately returns FALSE
 * @GST_ELEMENT_FLAG_LAST: offset to define more flags
 *
 * The standard flags that an element may have.
 */
206 207
typedef enum
{
208 209 210 211 212
  GST_ELEMENT_LOCKED_STATE      = (GST_OBJECT_FLAG_LAST << 0),
  GST_ELEMENT_IS_SINK           = (GST_OBJECT_FLAG_LAST << 1),
  GST_ELEMENT_UNPARENTING       = (GST_OBJECT_FLAG_LAST << 2),
  /* padding */
  GST_ELEMENT_FLAG_LAST         = (GST_OBJECT_FLAG_LAST << 16)
213
} GstElementFlags;
214

215 216
/**
 * GST_ELEMENT_IS_LOCKED_STATE:
217
 * @elem: A #GstElement to query
218
 *
219
 * Check if the element is in the locked state and therefore will ignore state
220 221
 * changes from its parent object.
 */
222
#define GST_ELEMENT_IS_LOCKED_STATE(elem)        (GST_OBJECT_FLAG_IS_SET(elem,GST_ELEMENT_LOCKED_STATE))
223

224 225
/**
 * GST_ELEMENT_NAME:
226
 * @elem: A #GstElement to query
227 228 229 230
 *
 * Gets the name of this element. Use only in core as this is not
 * ABI-compatible. Others use gst_element_get_name()
 */
Wim Taymans's avatar
Wim Taymans committed
231
#define GST_ELEMENT_NAME(elem)                  (GST_OBJECT_NAME(elem))
232 233 234

/**
 * GST_ELEMENT_PARENT:
235
 * @elem: A #GstElement to query
236 237 238
 *
 * Get the parent object of this element.
 */
Wim Taymans's avatar
Wim Taymans committed
239
#define GST_ELEMENT_PARENT(elem)                (GST_ELEMENT_CAST(GST_OBJECT_PARENT(elem)))
240 241 242

/**
 * GST_ELEMENT_BUS:
243
 * @elem: A #GstElement to query
244 245 246
 *
 * Get the message bus of this element.
 */
Wim Taymans's avatar
Wim Taymans committed
247
#define GST_ELEMENT_BUS(elem)                   (GST_ELEMENT_CAST(elem)->bus)
248 249 250

/**
 * GST_ELEMENT_CLOCK:
251
 * @elem: A #GstElement to query
252 253 254
 *
 * Get the clock of this element
 */
Wim Taymans's avatar
Wim Taymans committed
255
#define GST_ELEMENT_CLOCK(elem)                 (GST_ELEMENT_CAST(elem)->clock)
256 257 258

/**
 * GST_ELEMENT_PADS:
259
 * @elem: A #GstElement to query
260 261 262
 *
 * Get the pads of this elements.
 */
Wim Taymans's avatar
Wim Taymans committed
263
#define GST_ELEMENT_PADS(elem)                  (GST_ELEMENT_CAST(elem)->pads)
264

265 266 267 268 269 270 271 272 273
/**
 * GST_ELEMENT_START_TIME:
 * @elem: a #GstElement to return the start time for.
 *
 * This macro returns the start_time of the @elem. The start_time is the
 * running_time of the pipeline when the element went to PAUSED.
 *
 * Since: 0.10.24
 */
Wim Taymans's avatar
Wim Taymans committed
274
#define GST_ELEMENT_START_TIME(elem)            (GST_ELEMENT_CAST(elem)->abidata.ABI.start_time)
275

276 277
/**
 * GST_ELEMENT_ERROR:
278
 * @el:     the element that generates the error
279 280
 * @domain: like CORE, LIBRARY, RESOURCE or STREAM (see #gstreamer-GstGError)
 * @code:   error code defined for that domain (see #gstreamer-GstGError)
Thomas Vander Stichele's avatar
Thomas Vander Stichele committed
281 282 283 284
 * @text:   the message to display (format string and args enclosed in
            parentheses)
 * @debug:  debugging information for the message (format string and args
            enclosed in parentheses)
285 286
 *
 * Utility function that elements can use in case they encountered a fatal
287
 * data processing error. The pipeline will post an error message and the
288 289
 * application will be requested to stop further media processing.
 */
Wim Taymans's avatar
Wim Taymans committed
290 291 292 293 294 295 296 297 298 299 300
#define GST_ELEMENT_ERROR(el, domain, code, text, debug)                \
G_STMT_START {                                                          \
  gchar *__txt = _gst_element_error_printf text;                        \
  gchar *__dbg = _gst_element_error_printf debug;                       \
  if (__txt)                                                            \
    GST_WARNING_OBJECT (el, "error: %s", __txt);                        \
  if (__dbg)                                                            \
    GST_WARNING_OBJECT (el, "error: %s", __dbg);                        \
  gst_element_message_full (GST_ELEMENT(el), GST_MESSAGE_ERROR,         \
    GST_ ## domain ## _ERROR, GST_ ## domain ## _ERROR_ ## code,        \
    __txt, __dbg, __FILE__, GST_FUNCTION, __LINE__);                    \
301
} G_STMT_END
302

303 304
/**
 * GST_ELEMENT_WARNING:
305
 * @el:     the element that generates the warning
306 307
 * @domain: like CORE, LIBRARY, RESOURCE or STREAM (see #gstreamer-GstGError)
 * @code:   error code defined for that domain (see #gstreamer-GstGError)
308 309 310 311 312 313
 * @text:   the message to display (format string and args enclosed in
            parentheses)
 * @debug:  debugging information for the message (format string and args
            enclosed in parentheses)
 *
 * Utility function that elements can use in case they encountered a non-fatal
314
 * data processing problem. The pipeline will post a warning message and the
315 316
 * application will be informed.
 */
Wim Taymans's avatar
Wim Taymans committed
317 318 319 320 321 322 323 324 325 326 327
#define GST_ELEMENT_WARNING(el, domain, code, text, debug)              \
G_STMT_START {                                                          \
  gchar *__txt = _gst_element_error_printf text;                        \
  gchar *__dbg = _gst_element_error_printf debug;                       \
  if (__txt)                                                            \
    GST_WARNING_OBJECT (el, "warning: %s", __txt);                      \
  if (__dbg)                                                            \
    GST_WARNING_OBJECT (el, "warning: %s", __dbg);                      \
  gst_element_message_full (GST_ELEMENT(el), GST_MESSAGE_WARNING,       \
    GST_ ## domain ## _ERROR, GST_ ## domain ## _ERROR_ ## code,        \
  __txt, __dbg, __FILE__, GST_FUNCTION, __LINE__);                      \
Wim Taymans's avatar
Wim Taymans committed
328
} G_STMT_END
Erik Walthinsen's avatar
Erik Walthinsen committed
329

330 331 332 333 334 335 336 337 338 339 340 341 342 343
/**
 * GST_ELEMENT_INFO:
 * @el:     the element that generates the information
 * @domain: like CORE, LIBRARY, RESOURCE or STREAM (see #gstreamer-GstGError)
 * @code:   error code defined for that domain (see #gstreamer-GstGError)
 * @text:   the message to display (format string and args enclosed in
            parentheses)
 * @debug:  debugging information for the message (format string and args
            enclosed in parentheses)
 *
 * Utility function that elements can use in case they want to inform
 * the application of something noteworthy that is not an error.
 * The pipeline will post a warning message and the
 * application will be informed.
344 345
 *
 * Since: 0.10.12
346
 */
Wim Taymans's avatar
Wim Taymans committed
347 348 349 350 351 352 353 354 355 356 357
#define GST_ELEMENT_INFO(el, domain, code, text, debug)                 \
G_STMT_START {                                                          \
  gchar *__txt = _gst_element_error_printf text;                        \
  gchar *__dbg = _gst_element_error_printf debug;                       \
  if (__txt)                                                            \
    GST_INFO_OBJECT (el, "info: %s", __txt);                            \
  if (__dbg)                                                            \
    GST_INFO_OBJECT (el, "info: %s", __dbg);                            \
  gst_element_message_full (GST_ELEMENT(el), GST_MESSAGE_INFO,          \
    GST_ ## domain ## _ERROR, GST_ ## domain ## _ERROR_ ## code,        \
  __txt, __dbg, __FILE__, GST_FUNCTION, __LINE__);                      \
358 359
} G_STMT_END

360
/* the state change mutexes and conds */
Thomas Vander Stichele's avatar
Thomas Vander Stichele committed
361
/**
362 363
 * GST_STATE_GET_LOCK:
 * @elem:   a #GstElement
Thomas Vander Stichele's avatar
Thomas Vander Stichele committed
364
 *
365 366
 * Get a reference to the state lock of @elem.
 * This lock is used by the core.  It is taken while getting or setting
Thomas Vander Stichele's avatar
Thomas Vander Stichele committed
367 368
 * the state, during state changes, and while finalizing.
 */
369 370 371
#define GST_STATE_GET_LOCK(elem)               (GST_ELEMENT_CAST(elem)->state_lock)
/**
 * GST_STATE_GET_COND:
372
 * @elem: a #GstElement
373 374 375 376 377
 *
 * Get the conditional used to signal the completion of a state change.
 */
#define GST_STATE_GET_COND(elem)               (GST_ELEMENT_CAST(elem)->state_cond)

378 379 380 381 382
#define GST_STATE_LOCK(elem)                   g_static_rec_mutex_lock(GST_STATE_GET_LOCK(elem))
#define GST_STATE_TRYLOCK(elem)                g_static_rec_mutex_trylock(GST_STATE_GET_LOCK(elem))
#define GST_STATE_UNLOCK(elem)                 g_static_rec_mutex_unlock(GST_STATE_GET_LOCK(elem))
#define GST_STATE_UNLOCK_FULL(elem)            g_static_rec_mutex_unlock_full(GST_STATE_GET_LOCK(elem))
#define GST_STATE_LOCK_FULL(elem,t)            g_static_rec_mutex_lock_full(GST_STATE_GET_LOCK(elem), t)
383
#define GST_STATE_WAIT(elem)                   g_cond_wait (GST_STATE_GET_COND (elem), \
Wim Taymans's avatar
Wim Taymans committed
384
                                                        GST_OBJECT_GET_LOCK (elem))
385
#define GST_STATE_TIMED_WAIT(elem, timeval)    g_cond_timed_wait (GST_STATE_GET_COND (elem), \
Wim Taymans's avatar
Wim Taymans committed
386
                                                        GST_OBJECT_GET_LOCK (elem), timeval)
387 388 389
#define GST_STATE_SIGNAL(elem)                 g_cond_signal (GST_STATE_GET_COND (elem));
#define GST_STATE_BROADCAST(elem)              g_cond_broadcast (GST_STATE_GET_COND (elem));

390 391 392 393
/**
 * GstElement:
 * @state_lock: Used to serialize execution of gst_element_set_state()
 * @state_cond: Used to signal completion of a state change
394 395
 * @state_cookie: Used to detect concurrent execution of
 * gst_element_set_state() and gst_element_get_state()
396
 * @current_state: the current state of an element
397 398 399 400
 * @next_state: the next state of an element, can be #GST_STATE_VOID_PENDING if
 * the element is in the correct state.
 * @pending_state: the final state the element should go to, can be
 * #GST_STATE_VOID_PENDING if the element is in the correct state
401
 * @last_return: the last return value of an element state change
402 403 404 405 406 407
 * @bus: the bus of the element. This bus is provided to the element by the
 * parent element or the application. A #GstPipeline has a bus of its own.
 * @clock: the clock of the element. This clock is usually provided by to the
 * element by the toplevel #GstPipeline.
 * @base_time: the time of the clock right before the element is set to
 * PLAYING. Subtracting @base_time from the current clock time in the PLAYING
408
 * state will yield the running_time against the clock.
409 410 411 412 413 414 415 416 417 418
 * @numpads: number of pads of the element, includes both source and sink pads.
 * @pads: list of pads
 * @numsrcpads: number of source pads of the element.
 * @srcpads: list of source pads
 * @numsinkpads: number of sink pads of the element.
 * @sinkpads: list of sink pads
 * @pads_cookie: updated whenever the a pad is added or removed
 *
 * GStreamer element abstract base class.
 */
Wim Taymans's avatar
Wim Taymans committed
419
struct _GstElement
420
{
Wim Taymans's avatar
Wim Taymans committed
421
  GstObject             object;
Erik Walthinsen's avatar
Erik Walthinsen committed
422

423
  /*< public >*/ /* with LOCK */
424
  GStaticRecMutex      *state_lock;
425 426

  /* element state */
427
  GCond                *state_cond;
Wim Taymans's avatar
Wim Taymans committed
428
  guint32               state_cookie;
429 430 431 432 433
  GstState              current_state;
  GstState              next_state;
  GstState              pending_state;
  GstStateChangeReturn  last_return;

Wim Taymans's avatar
Wim Taymans committed
434
  GstBus               *bus;
Wim Taymans's avatar
Wim Taymans committed
435 436

  /* allocated clock */
Wim Taymans's avatar
Wim Taymans committed
437 438
  GstClock             *clock;
  GstClockTimeDiff      base_time; /* NULL/READY: 0 - PAUSED: current time - PLAYING: difference to clock */
439

440
  /* element pads, these lists can only be iterated while holding
441
   * the LOCK or checking the cookie after each LOCK. */
442 443 444 445 446 447 448 449 450
  guint16               numpads;
  GList                *pads;
  guint16               numsrcpads;
  GList                *srcpads;
  guint16               numsinkpads;
  GList                *sinkpads;
  guint32               pads_cookie;

  /*< private >*/
451 452 453 454
  union {
    struct {
      /* state set by application */
      GstState              target_state;
455 456
      /* running time of the last PAUSED state */
      GstClockTime          start_time;
457 458 459 460
    } ABI;
    /* adding + 0 to mark ABI change to be undone later */
    gpointer _gst_reserved[GST_PADDING + 0];
  } abidata;
Erik Walthinsen's avatar
Erik Walthinsen committed
461 462
};

463 464 465 466 467 468
/**
 * GstElementClass:
 * @parent_class: the parent class structure
 * @details: #GstElementDetails for elements of this class
 * @elementfactory: the #GstElementFactory that creates these elements
 * @padtemplates: a #GList of #GstPadTemplate
469
 * @numpadtemplates: the number of padtemplates
470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487
 * @pad_templ_cookie: changed whenever the padtemplates change
 * @request_new_pad: called when a new pad is requested
 * @release_pad: called when a request pad is to be released
 * @get_state: get the state of the element
 * @set_state: set a new state on the element
 * @change_state: called by @set_state to perform an incremental state change
 * @set_bus: set a #GstBus on the element
 * @provide_clock: gets the #GstClock provided by the element
 * @set_clock: set the #GstClock on the element
 * @get_index: set a #GstIndex on the element
 * @set_index: get the #GstIndex of an element
 * @send_event: send a #GstEvent to the element
 * @get_query_types: get the supported #GstQueryType of this element
 * @query: perform a #GstQuery on the element
 *
 * GStreamer element class. Override the vmethods to implement the element
 * functionality.
 */
488 489
struct _GstElementClass
{
490
  GstObjectClass         parent_class;
Erik Walthinsen's avatar
Erik Walthinsen committed
491

492
  /*< public >*/
493
  /* the element details */
Wim Taymans's avatar
Wim Taymans committed
494
  GstElementDetails      details;
495 496

  /* factory that the element was created from */
Wim Taymans's avatar
Wim Taymans committed
497
  GstElementFactory     *elementfactory;
498

499
  /* templates for our pads */
500 501 502
  GList                 *padtemplates;
  gint                   numpadtemplates;
  guint32                pad_templ_cookie;
503

504
  /*< private >*/
Erik Walthinsen's avatar
Erik Walthinsen committed
505
  /* signal callbacks */
Wim Taymans's avatar
Wim Taymans committed
506 507 508
  void (*pad_added)     (GstElement *element, GstPad *pad);
  void (*pad_removed)   (GstElement *element, GstPad *pad);
  void (*no_more_pads)  (GstElement *element);
509

510 511
  /*< public >*/
  /* virtual methods for subclasses */
512 513

  /* request/release pads */
Wim Taymans's avatar
Wim Taymans committed
514 515
  GstPad*               (*request_new_pad)      (GstElement *element, GstPadTemplate *templ, const gchar* name);
  void                  (*release_pad)          (GstElement *element, GstPad *pad);
516

517
  /* state changes */
Wim Taymans's avatar
Wim Taymans committed
518 519 520 521
  GstStateChangeReturn (*get_state)             (GstElement * element, GstState * state,
                                                 GstState * pending, GstClockTime timeout);
  GstStateChangeReturn (*set_state)             (GstElement *element, GstState state);
  GstStateChangeReturn (*change_state)          (GstElement *element, GstStateChange transition);
522

Wim Taymans's avatar
Wim Taymans committed
523
  /* bus */
Wim Taymans's avatar
Wim Taymans committed
524
  void                  (*set_bus)              (GstElement * element, GstBus * bus);
525

526
  /* set/get clocks */
Wim Taymans's avatar
Wim Taymans committed
527 528
  GstClock*             (*provide_clock)        (GstElement *element);
  gboolean              (*set_clock)            (GstElement *element, GstClock *clock);
529

Wim Taymans's avatar
Wim Taymans committed
530
  /* index */
Wim Taymans's avatar
Wim Taymans committed
531 532
  GstIndex*             (*get_index)            (GstElement *element);
  void                  (*set_index)            (GstElement *element, GstIndex *index);
Wim Taymans's avatar
Wim Taymans committed
533

534
  /* query functions */
Wim Taymans's avatar
Wim Taymans committed
535
  gboolean              (*send_event)           (GstElement *element, GstEvent *event);
536

Wim Taymans's avatar
Wim Taymans committed
537 538
  const GstQueryType*   (*get_query_types)      (GstElement *element);
  gboolean              (*query)                (GstElement *element, GstQuery *query);
Wim Taymans's avatar
Wim Taymans committed
539

540 541
  /*< private >*/
  gpointer _gst_reserved[GST_PADDING];
Erik Walthinsen's avatar
Erik Walthinsen committed
542 543
};

544
/* element class pad templates */
Wim Taymans's avatar
Wim Taymans committed
545 546 547 548 549 550 551 552 553
void                    gst_element_class_add_pad_template      (GstElementClass *klass, GstPadTemplate *templ);
GstPadTemplate*         gst_element_class_get_pad_template      (GstElementClass *element_class, const gchar *name);
GList*                  gst_element_class_get_pad_template_list (GstElementClass *element_class);
void                    gst_element_class_set_details           (GstElementClass *klass, const GstElementDetails *details);
void                    gst_element_class_set_details_simple    (GstElementClass *klass,
                                                                 const gchar     *longname,
                                                                 const gchar     *classification,
                                                                 const gchar     *description,
                                                                 const gchar     *author);
554

555
/* element instance */
Wim Taymans's avatar
Wim Taymans committed
556
GType                   gst_element_get_type            (void);
Erik Walthinsen's avatar
Erik Walthinsen committed
557

558
/* basic name and parentage stuff from GstObject */
559 560 561 562 563 564 565

/**
 * gst_element_get_name:
 * @elem: a #GstElement to set the name of.
 *
 * Gets the name of the element.
 */
Wim Taymans's avatar
Wim Taymans committed
566
#define                 gst_element_get_name(elem)      gst_object_get_name(GST_OBJECT_CAST(elem))
567 568 569 570

/**
 * gst_element_set_name:
 * @elem: a #GstElement to set the name of.
571
 * @name: the new name
572 573 574
 *
 * Sets the name of the element, getting rid of the old name if there was one.
 */
Wim Taymans's avatar
Wim Taymans committed
575
#define                 gst_element_set_name(elem,name) gst_object_set_name(GST_OBJECT_CAST(elem),name)
576 577 578 579 580 581 582

/**
 * gst_element_get_parent:
 * @elem: a #GstElement to get the parent of.
 *
 * Gets the parent of an element.
 */
Wim Taymans's avatar
Wim Taymans committed
583
#define                 gst_element_get_parent(elem)    gst_object_get_parent(GST_OBJECT_CAST(elem))
584 585 586 587

/**
 * gst_element_set_parent:
 * @elem: a #GstElement to set the parent of.
Thomas Vander Stichele's avatar
Thomas Vander Stichele committed
588
 * @parent: the new parent #GstObject of the element.
589 590 591
 *
 * Sets the parent of an element.
 */
Wim Taymans's avatar
Wim Taymans committed
592
#define                 gst_element_set_parent(elem,parent)     gst_object_set_parent(GST_OBJECT_CAST(elem),parent)
Thomas Vander Stichele's avatar
Thomas Vander Stichele committed
593

594
/* clocking */
Wim Taymans's avatar
Wim Taymans committed
595 596 597 598 599 600 601 602 603
gboolean                gst_element_requires_clock      (GstElement *element);
gboolean                gst_element_provides_clock      (GstElement *element);
GstClock*               gst_element_provide_clock       (GstElement *element);
GstClock*               gst_element_get_clock           (GstElement *element);
gboolean                gst_element_set_clock           (GstElement *element, GstClock *clock);
void                    gst_element_set_base_time       (GstElement *element, GstClockTime time);
GstClockTime            gst_element_get_base_time       (GstElement *element);
void                    gst_element_set_start_time      (GstElement *element, GstClockTime time);
GstClockTime            gst_element_get_start_time      (GstElement *element);
604 605

/* indexes */
Wim Taymans's avatar
Wim Taymans committed
606 607 608
gboolean                gst_element_is_indexable        (GstElement *element);
void                    gst_element_set_index           (GstElement *element, GstIndex *index);
GstIndex*               gst_element_get_index           (GstElement *element);
609

Wim Taymans's avatar
Wim Taymans committed
610
/* bus */
Wim Taymans's avatar
Wim Taymans committed
611 612
void                    gst_element_set_bus             (GstElement * element, GstBus * bus);
GstBus *                gst_element_get_bus             (GstElement * element);
613

614
/* pad management */
Wim Taymans's avatar
Wim Taymans committed
615 616 617
gboolean                gst_element_add_pad             (GstElement *element, GstPad *pad);
gboolean                gst_element_remove_pad          (GstElement *element, GstPad *pad);
void                    gst_element_no_more_pads        (GstElement *element);
618

619
#ifndef GST_DISABLE_DEPRECATED
Wim Taymans's avatar
Wim Taymans committed
620
GstPad*                 gst_element_get_pad             (GstElement *element, const gchar *name);
621
#endif /* GST_DISABLE_DEPRECATED */
Wim Taymans's avatar
Wim Taymans committed
622 623 624
GstPad*                 gst_element_get_static_pad      (GstElement *element, const gchar *name);
GstPad*                 gst_element_get_request_pad     (GstElement *element, const gchar *name);
void                    gst_element_release_request_pad (GstElement *element, GstPad *pad);
625

Wim Taymans's avatar
Wim Taymans committed
626 627 628
GstIterator *           gst_element_iterate_pads        (GstElement * element);
GstIterator *           gst_element_iterate_src_pads    (GstElement * element);
GstIterator *           gst_element_iterate_sink_pads   (GstElement * element);
629

630
/* event/query/format stuff */
Wim Taymans's avatar
Wim Taymans committed
631 632 633 634 635
gboolean                gst_element_send_event          (GstElement *element, GstEvent *event);
gboolean                gst_element_seek                (GstElement *element, gdouble rate,
                                                         GstFormat format, GstSeekFlags flags,
                                                         GstSeekType cur_type, gint64 cur,
                                                         GstSeekType stop_type, gint64 stop);
636
G_CONST_RETURN GstQueryType*
Wim Taymans's avatar
Wim Taymans committed
637 638
                        gst_element_get_query_types     (GstElement *element);
gboolean                gst_element_query               (GstElement *element, GstQuery *query);
639

Wim Taymans's avatar
Wim Taymans committed
640
/* messages */
Wim Taymans's avatar
Wim Taymans committed
641
gboolean                gst_element_post_message        (GstElement * element, GstMessage * message);
Wim Taymans's avatar
Wim Taymans committed
642

643
/* error handling */
644 645
/* gcc versions < 3.3 warn about NULL being passed as format to printf */
#if (defined(GST_USING_PRINTF_EXTENSION) || !defined(__GNUC__) || (__GNUC__ < 3) || (__GNUC__ == 3 && __GNUC_MINOR__ < 3))
Wim Taymans's avatar
Wim Taymans committed
646
gchar *                 _gst_element_error_printf       (const gchar *format, ...);
647
#else
Wim Taymans's avatar
Wim Taymans committed
648
gchar *                 _gst_element_error_printf       (const gchar *format, ...) G_GNUC_PRINTF (1, 2);
649
#endif
Wim Taymans's avatar
Wim Taymans committed
650 651 652 653
void                    gst_element_message_full        (GstElement * element, GstMessageType type,
                                                         GQuark domain, gint code, gchar * text,
                                                         gchar * debug, const gchar * file,
                                                         const gchar * function, gint line);
654 655

/* state management */
Wim Taymans's avatar
Wim Taymans committed
656 657 658
gboolean                gst_element_is_locked_state     (GstElement *element);
gboolean                gst_element_set_locked_state    (GstElement *element, gboolean locked_state);
gboolean                gst_element_sync_state_with_parent (GstElement *element);
659

Wim Taymans's avatar
Wim Taymans committed
660 661 662 663 664
GstStateChangeReturn    gst_element_get_state           (GstElement * element,
                                                         GstState * state,
                                                         GstState * pending,
                                                         GstClockTime timeout);
GstStateChangeReturn    gst_element_set_state           (GstElement *element, GstState state);
665

Wim Taymans's avatar
Wim Taymans committed
666
void                    gst_element_abort_state         (GstElement * element);
667
GstStateChangeReturn    gst_element_change_state        (GstElement * element,
Wim Taymans's avatar
Wim Taymans committed
668 669
                                                         GstStateChange transition);
GstStateChangeReturn    gst_element_continue_state      (GstElement * element,
670
                                                         GstStateChangeReturn ret);
Wim Taymans's avatar
Wim Taymans committed
671 672
void                    gst_element_lost_state          (GstElement * element);
void                    gst_element_lost_state_full     (GstElement * element, gboolean new_base_time);
Wim Taymans's avatar
Wim Taymans committed
673

674
/* factory management */
Wim Taymans's avatar
Wim Taymans committed
675
GstElementFactory*      gst_element_get_factory         (GstElement *element);
676

677
G_END_DECLS
678

679
#endif /* __GST_ELEMENT_H__ */