2 * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
3 * 2000 Wim Taymans <wim.taymans@chello.be>
4 * 2005 Wim Taymans <wim@fluendo.com>
6 * gstevent.h: Header for GstEvent subsystem
8 * This library is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Library General Public
10 * License as published by the Free Software Foundation; either
11 * version 2 of the License, or (at your option) any later version.
13 * This library is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Library General Public License for more details.
18 * You should have received a copy of the GNU Library General Public
19 * License along with this library; if not, write to the
20 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
21 * Boston, MA 02111-1307, USA.
25 #ifndef __GST_EVENT_H__
26 #define __GST_EVENT_H__
28 #include <gst/gstminiobject.h>
29 #include <gst/gstformat.h>
30 #include <gst/gstobject.h>
31 #include <gst/gstclock.h>
32 #include <gst/gststructure.h>
33 #include <gst/gsttaglist.h>
39 * @GST_EVENT_TYPE_UPSTREAM: Set if the event can travel upstream.
40 * @GST_EVENT_TYPE_DOWNSTREAM: Set if the event can travel downstream.
41 * @GST_EVENT_TYPE_SERIALIZED: Set if the event should be serialized with data
43 * @GST_EVENT_TYPE_STICKY: Set if the event is sticky on the pads.
45 * #GstEventTypeFlags indicate the aspects of the different #GstEventType
46 * values. You can get the type flags of a #GstEventType with the
47 * gst_event_type_get_flags() function.
50 GST_EVENT_TYPE_UPSTREAM = 1 << 0,
51 GST_EVENT_TYPE_DOWNSTREAM = 1 << 1,
52 GST_EVENT_TYPE_SERIALIZED = 1 << 2,
53 GST_EVENT_TYPE_STICKY = 1 << 3
57 * GST_EVENT_TYPE_BOTH:
59 * The same thing as #GST_EVENT_TYPE_UPSTREAM | #GST_EVENT_TYPE_DOWNSTREAM.
61 #define GST_EVENT_TYPE_BOTH \
62 (GST_EVENT_TYPE_UPSTREAM | GST_EVENT_TYPE_DOWNSTREAM)
64 #define GST_EVENT_MAX_STICKY 16
65 #define GST_EVENT_STICKY_SHIFT 8
66 #define GST_EVENT_NUM_SHIFT (GST_EVENT_STICKY_SHIFT + 4)
69 * GST_EVENT_MAKE_TYPE:
70 * @num: the event number to create
71 * @idx: the index in the sticky array
72 * @flags: the event flags
74 * when making custom event types, use this macro with the num and
77 #define GST_EVENT_MAKE_TYPE(num,idx,flags) \
78 (((num) << GST_EVENT_NUM_SHIFT) | ((idx) << GST_EVENT_STICKY_SHIFT) | (flags))
80 #define FLAG(name) GST_EVENT_TYPE_##name
83 #define GST_EVENT_STICKY_IDX_TYPE(type) (((type) >> GST_EVENT_STICKY_SHIFT) & 0xf)
84 #define GST_EVENT_STICKY_IDX(ev) GST_EVENT_STICKY_IDX_TYPE(GST_EVENT_TYPE(ev))
88 * @GST_EVENT_UNKNOWN: unknown event.
89 * @GST_EVENT_FLUSH_START: Start a flush operation. This event clears all data
90 * from the pipeline and unblock all streaming threads.
91 * @GST_EVENT_FLUSH_STOP: Stop a flush operation. This event resets the
92 * running-time of the pipeline.
93 * @GST_EVENT_EOS: End-Of-Stream. No more data is to be expected to follow
94 * without a NEWSEGMENT event.
95 * @GST_EVENT_NEWSEGMENT: A new media segment follows in the dataflow. The
96 * segment events contains information for clipping buffers and
97 * converting buffer timestamps to running-time and
99 * @GST_EVENT_TAG: A new set of metadata tags has been found in the stream.
100 * @GST_EVENT_BUFFERSIZE: Notification of buffering requirements. Currently not
102 * @GST_EVENT_SINK_MESSAGE: An event that sinks turn into a message. Used to
103 * send messages that should be emitted in sync with
106 * @GST_EVENT_QOS: A quality message. Used to indicate to upstream elements
107 * that the downstream elements should adjust their processing
109 * @GST_EVENT_SEEK: A request for a new playback position and rate.
110 * @GST_EVENT_NAVIGATION: Navigation events are usually used for communicating
111 * user requests, such as mouse or keyboard movements,
112 * to upstream elements.
113 * @GST_EVENT_LATENCY: Notification of new latency adjustment. Sinks will use
114 * the latency information to adjust their synchronisation.
116 * @GST_EVENT_STEP: A request for stepping through the media. Sinks will usually
117 * execute the step operation. Since: 0.10.24
118 * @GST_EVENT_RECONFIGURE: A request for upstream renegotiating caps and reconfiguring.
120 * @GST_EVENT_CUSTOM_UPSTREAM: Upstream custom event
121 * @GST_EVENT_CUSTOM_DOWNSTREAM: Downstream custom event that travels in the
123 * @GST_EVENT_CUSTOM_DOWNSTREAM_OOB: Custom out-of-band downstream event.
124 * @GST_EVENT_CUSTOM_BOTH: Custom upstream or downstream event.
125 * In-band when travelling downstream.
126 * @GST_EVENT_CUSTOM_BOTH_OOB: Custom upstream or downstream out-of-band event.
128 * #GstEventType lists the standard event types that can be sent in a pipeline.
130 * The custom event types can be used for private messages between elements
131 * that can't be expressed using normal
132 * GStreamer buffer passing semantics. Custom events carry an arbitrary
134 * Specific custom events are distinguished by the name of the structure.
136 /* NOTE: keep in sync with quark registration in gstevent.c */
138 GST_EVENT_UNKNOWN = GST_EVENT_MAKE_TYPE (0, 0, 0),
139 /* bidirectional events */
140 GST_EVENT_FLUSH_START = GST_EVENT_MAKE_TYPE (1, 0, FLAG(BOTH)),
141 GST_EVENT_FLUSH_STOP = GST_EVENT_MAKE_TYPE (2, 0, FLAG(BOTH) | FLAG(SERIALIZED)),
142 /* downstream serialized events */
143 GST_EVENT_CAPS = GST_EVENT_MAKE_TYPE (5, 1, FLAG(DOWNSTREAM) | FLAG(SERIALIZED) | FLAG(STICKY)),
144 GST_EVENT_NEWSEGMENT = GST_EVENT_MAKE_TYPE (6, 2, FLAG(DOWNSTREAM) | FLAG(SERIALIZED) | FLAG(STICKY)),
145 GST_EVENT_TAG = GST_EVENT_MAKE_TYPE (7, 3, FLAG(DOWNSTREAM) | FLAG(SERIALIZED) | FLAG(STICKY)),
146 GST_EVENT_BUFFERSIZE = GST_EVENT_MAKE_TYPE (8, 4, FLAG(DOWNSTREAM) | FLAG(SERIALIZED) | FLAG(STICKY)),
147 GST_EVENT_SINK_MESSAGE = GST_EVENT_MAKE_TYPE (9, 5, FLAG(DOWNSTREAM) | FLAG(SERIALIZED) | FLAG(STICKY)),
148 GST_EVENT_EOS = GST_EVENT_MAKE_TYPE (10, 6, FLAG(DOWNSTREAM) | FLAG(SERIALIZED) | FLAG(STICKY)),
149 /* upstream events */
150 GST_EVENT_QOS = GST_EVENT_MAKE_TYPE (15, 0, FLAG(UPSTREAM)),
151 GST_EVENT_SEEK = GST_EVENT_MAKE_TYPE (16, 0, FLAG(UPSTREAM)),
152 GST_EVENT_NAVIGATION = GST_EVENT_MAKE_TYPE (17, 0, FLAG(UPSTREAM)),
153 GST_EVENT_LATENCY = GST_EVENT_MAKE_TYPE (18, 0, FLAG(UPSTREAM)),
154 GST_EVENT_STEP = GST_EVENT_MAKE_TYPE (19, 0, FLAG(UPSTREAM)),
155 GST_EVENT_RECONFIGURE = GST_EVENT_MAKE_TYPE (20, 0, FLAG(UPSTREAM)),
157 /* custom events start here */
158 GST_EVENT_CUSTOM_UPSTREAM = GST_EVENT_MAKE_TYPE (32, 0, FLAG(UPSTREAM)),
159 GST_EVENT_CUSTOM_DOWNSTREAM = GST_EVENT_MAKE_TYPE (32, 0, FLAG(DOWNSTREAM) | FLAG(SERIALIZED)),
160 GST_EVENT_CUSTOM_DOWNSTREAM_OOB = GST_EVENT_MAKE_TYPE (32, 0, FLAG(DOWNSTREAM)),
161 GST_EVENT_CUSTOM_BOTH = GST_EVENT_MAKE_TYPE (32, 0, FLAG(BOTH) | FLAG(SERIALIZED)),
162 GST_EVENT_CUSTOM_BOTH_OOB = GST_EVENT_MAKE_TYPE (32, 0, FLAG(BOTH))
167 * GST_EVENT_TRACE_NAME:
169 * The name used for memory allocation tracing
171 #define GST_EVENT_TRACE_NAME "GstEvent"
173 typedef struct _GstEvent GstEvent;
175 #define GST_TYPE_EVENT (gst_event_get_type())
176 #define GST_IS_EVENT(obj) (GST_IS_MINI_OBJECT_TYPE (obj, GST_TYPE_EVENT))
177 #define GST_EVENT(obj) ((GstEvent *)(obj))
178 #define GST_EVENT_CAST(obj) ((GstEvent *)(obj))
182 * @event: the event to query
184 * Get the #GstEventType of the event.
186 #define GST_EVENT_TYPE(event) (GST_EVENT_CAST(event)->type)
189 * GST_EVENT_TYPE_NAME:
190 * @event: the event to query
192 * Get a constant string representation of the #GstEventType of the event.
194 #define GST_EVENT_TYPE_NAME(event) (gst_event_type_get_name(GST_EVENT_TYPE(event)))
197 * GST_EVENT_TIMESTAMP:
198 * @event: the event to query
200 * Get the #GstClockTime timestamp of the event. This is the time when the event
203 #define GST_EVENT_TIMESTAMP(event) (GST_EVENT_CAST(event)->timestamp)
207 * @event: the event to query
209 * The sequence number of @event.
211 #define GST_EVENT_SEQNUM(event) (GST_EVENT_CAST(event)->seqnum)
214 * GST_EVENT_IS_UPSTREAM:
215 * @ev: the event to query
217 * Check if an event can travel upstream.
219 #define GST_EVENT_IS_UPSTREAM(ev) !!(GST_EVENT_TYPE (ev) & GST_EVENT_TYPE_UPSTREAM)
221 * GST_EVENT_IS_DOWNSTREAM:
222 * @ev: the event to query
224 * Check if an event can travel downstream.
226 #define GST_EVENT_IS_DOWNSTREAM(ev) !!(GST_EVENT_TYPE (ev) & GST_EVENT_TYPE_DOWNSTREAM)
228 * GST_EVENT_IS_SERIALIZED:
229 * @ev: the event to query
231 * Check if an event is serialized with the data stream.
233 #define GST_EVENT_IS_SERIALIZED(ev) !!(GST_EVENT_TYPE (ev) & GST_EVENT_TYPE_SERIALIZED)
235 * GST_EVENT_IS_STICKY:
236 * @ev: the event to query
238 * Check if an event is sticky on the pads.
240 #define GST_EVENT_IS_STICKY(ev) !!(GST_EVENT_TYPE (ev) & GST_EVENT_TYPE_STICKY)
243 * gst_event_is_writable:
246 * Tests if you can safely write data into a event's structure or validly
247 * modify the seqnum and timestamp field.
249 #define gst_event_is_writable(ev) gst_mini_object_is_writable (GST_MINI_OBJECT_CAST (ev))
251 * gst_event_make_writable:
252 * @ev: (transfer full): a #GstEvent
254 * Makes a writable event from the given event. If the source event is
255 * already writable, this will simply return the same event. A copy will
256 * otherwise be made using gst_event_copy().
258 * Returns: (transfer full): a writable event which may or may not be the
261 #define gst_event_make_writable(ev) GST_EVENT_CAST (gst_mini_object_make_writable (GST_MINI_OBJECT_CAST (ev)))
264 * @old_event: (inout) (transfer full): pointer to a pointer to a #GstEvent
266 * @new_event: (allow-none) (transfer none): pointer to a #GstEvent that will
267 * replace the event pointed to by @old_event.
269 * Modifies a pointer to a #GstEvent to point to a different #GstEvent. The
270 * modification is done atomically (so this is useful for ensuring thread safety
271 * in some cases), and the reference counts are updated appropriately (the old
272 * event is unreffed, the new one is reffed).
274 * Either @new_event or the #GstEvent pointed to by @old_event may be NULL.
278 #define gst_event_replace(old_event,new_event) \
279 gst_mini_object_replace ((GstMiniObject **)(old_event), GST_MINI_OBJECT_CAST (new_event))
283 * @GST_SEEK_TYPE_NONE: no change in position is required
284 * @GST_SEEK_TYPE_CUR: change relative to currently configured segment. This
285 * can't be used to seek relative to the current playback position - do a
286 * position query, calculate the desired position and then do an absolute
287 * position seek instead if that's what you want to do.
288 * @GST_SEEK_TYPE_SET: absolute position is requested
289 * @GST_SEEK_TYPE_END: relative position to duration is requested
291 * The different types of seek events. When constructing a seek event with
292 * gst_event_new_seek(), a format, a seek method and optional flags are to
293 * be provided. The seek event is then inserted into the graph with
294 * gst_pad_send_event() or gst_element_send_event().
298 GST_SEEK_TYPE_NONE = 0,
299 GST_SEEK_TYPE_CUR = 1,
300 GST_SEEK_TYPE_SET = 2,
301 GST_SEEK_TYPE_END = 3
306 * @GST_SEEK_FLAG_NONE: no flag
307 * @GST_SEEK_FLAG_FLUSH: flush pipeline
308 * @GST_SEEK_FLAG_ACCURATE: accurate position is requested, this might
309 * be considerably slower for some formats.
310 * @GST_SEEK_FLAG_KEY_UNIT: seek to the nearest keyframe. This might be
311 * faster but less accurate.
312 * @GST_SEEK_FLAG_SEGMENT: perform a segment seek.
313 * @GST_SEEK_FLAG_SKIP: when doing fast foward or fast reverse playback, allow
314 * elements to skip frames instead of generating all
315 * frames. Since 0.10.22.
317 * Flags to be used with gst_element_seek() or gst_event_new_seek(). All flags
318 * can be used together.
320 * A non flushing seek might take some time to perform as the currently
321 * playing data in the pipeline will not be cleared.
323 * An accurate seek might be slower for formats that don't have any indexes
324 * or timestamp markers in the stream. Specifying this flag might require a
325 * complete scan of the file in those cases.
327 * When performing a segment seek: after the playback of the segment completes,
328 * no EOS will be emmited by the element that performed the seek, but a
329 * #GST_MESSAGE_SEGMENT_DONE message will be posted on the bus by the element.
330 * When this message is posted, it is possible to send a new seek event to
331 * continue playback. With this seek method it is possible to perform seemless
332 * looping or simple linear editing.
334 * When doing fast forward (rate > 1.0) or fast reverse (rate < -1.0) trickmode
335 * playback, the @GST_SEEK_FLAG_SKIP flag can be used to instruct decoders
336 * and demuxers to adjust the playback rate by skipping frames. This can improve
337 * performance and decrease CPU usage because not all frames need to be decoded.
339 * Also see part-seeking.txt in the GStreamer design documentation for more
340 * details on the meaning of these flags and the behaviour expected of
341 * elements that handle them.
344 GST_SEEK_FLAG_NONE = 0,
345 GST_SEEK_FLAG_FLUSH = (1 << 0),
346 GST_SEEK_FLAG_ACCURATE = (1 << 1),
347 GST_SEEK_FLAG_KEY_UNIT = (1 << 2),
348 GST_SEEK_FLAG_SEGMENT = (1 << 3),
349 GST_SEEK_FLAG_SKIP = (1 << 4)
354 * @GST_QOS_TYPE_OVERFLOW: The QoS event type that is produced when downstream
355 * elements are producing data too quickly and the element can't keep up
356 * processing the data. Upstream should reduce their processing rate. This
357 * type is also used when buffers arrive early or in time.
358 * @GST_QOS_TYPE_UNDERFLOW: The QoS event type that is produced when downstream
359 * elements are producing data too slowly and need to speed up their processing
361 * @GST_QOS_TYPE_THROTTLE: The QoS event type that is produced when the
362 * application enabled throttling to limit the datarate.
364 * The different types of QoS events that can be given to the
365 * gst_event_new_qos() method.
370 GST_QOS_TYPE_OVERFLOW = 0,
371 GST_QOS_TYPE_UNDERFLOW = 1,
372 GST_QOS_TYPE_THROTTLE = 2
377 * @mini_object: the parent structure
378 * @type: the #GstEventType of the event
379 * @timestamp: the timestamp of the event
380 * @structure: the #GstStructure containing the event info.
385 GstMiniObject mini_object;
387 /*< public >*/ /* with COW */
393 const gchar* gst_event_type_get_name (GstEventType type);
394 GQuark gst_event_type_to_quark (GstEventType type);
396 gst_event_type_get_flags (GstEventType type);
399 GType gst_event_get_type (void);
404 * @event: The event to refcount
406 * Increase the refcount of this event.
408 * Returns: (transfer full): @event (for convenience when doing assignments)
410 #ifdef _FOOL_GTK_DOC_
411 G_INLINE_FUNC GstEvent * gst_event_ref (GstEvent * event);
414 static inline GstEvent *
415 gst_event_ref (GstEvent * event)
417 return (GstEvent *) gst_mini_object_ref (GST_MINI_OBJECT_CAST (event));
422 * @event: (transfer full): the event to refcount
424 * Decrease the refcount of an event, freeing it if the refcount reaches 0.
426 #ifdef _FOOL_GTK_DOC_
427 G_INLINE_FUNC void gst_event_unref (GstEvent * event);
431 gst_event_unref (GstEvent * event)
433 gst_mini_object_unref (GST_MINI_OBJECT_CAST (event));
439 * @event: The event to copy
441 * Copy the event using the event specific copy function.
443 * Returns: (transfer full): the new event
445 #ifdef _FOOL_GTK_DOC_
446 G_INLINE_FUNC GstEvent * gst_event_copy (const GstEvent * event);
449 static inline GstEvent *
450 gst_event_copy (const GstEvent * event)
452 return GST_EVENT_CAST (gst_mini_object_copy (GST_MINI_OBJECT_CONST_CAST (event)));
457 GstEvent* gst_event_new_custom (GstEventType type, GstStructure *structure);
460 gst_event_get_structure (GstEvent *event);
461 GstStructure * gst_event_writable_structure (GstEvent *event);
463 gboolean gst_event_has_name (GstEvent *event, const gchar *name);
465 /* identifiers for events and messages */
466 guint32 gst_event_get_seqnum (GstEvent *event);
467 void gst_event_set_seqnum (GstEvent *event, guint32 seqnum);
470 GstEvent * gst_event_new_flush_start (void);
471 GstEvent * gst_event_new_flush_stop (void);
474 GstEvent * gst_event_new_eos (void);
477 GstEvent * gst_event_new_caps (GstCaps *caps);
478 void gst_event_parse_caps (GstEvent *event, GstCaps **caps);
480 /* newsegment events */
481 GstEvent* gst_event_new_new_segment (gboolean update, gdouble rate,
482 gdouble applied_rate,
484 gint64 start, gint64 stop,
486 void gst_event_parse_new_segment (GstEvent *event,
489 gdouble *applied_rate,
491 gint64 *start, gint64 *stop,
495 GstEvent* gst_event_new_tag (GstTagList *taglist);
496 void gst_event_parse_tag (GstEvent *event, GstTagList **taglist);
499 GstEvent * gst_event_new_buffer_size (GstFormat format, gint64 minsize, gint64 maxsize,
501 void gst_event_parse_buffer_size (GstEvent *event, GstFormat *format, gint64 *minsize,
502 gint64 *maxsize, gboolean *async);
505 GstEvent* gst_event_new_qos (GstQOSType type, gdouble proportion,
506 GstClockTimeDiff diff, GstClockTime timestamp);
507 void gst_event_parse_qos (GstEvent *event, GstQOSType *type,
508 gdouble *proportion, GstClockTimeDiff *diff,
509 GstClockTime *timestamp);
511 GstEvent* gst_event_new_seek (gdouble rate, GstFormat format, GstSeekFlags flags,
512 GstSeekType start_type, gint64 start,
513 GstSeekType stop_type, gint64 stop);
514 void gst_event_parse_seek (GstEvent *event, gdouble *rate, GstFormat *format,
516 GstSeekType *start_type, gint64 *start,
517 GstSeekType *stop_type, gint64 *stop);
518 /* navigation event */
519 GstEvent* gst_event_new_navigation (GstStructure *structure);
522 GstEvent* gst_event_new_latency (GstClockTime latency);
523 void gst_event_parse_latency (GstEvent *event, GstClockTime *latency);
526 GstEvent* gst_event_new_step (GstFormat format, guint64 amount, gdouble rate,
527 gboolean flush, gboolean intermediate);
528 void gst_event_parse_step (GstEvent *event, GstFormat *format, guint64 *amount,
529 gdouble *rate, gboolean *flush, gboolean *intermediate);
531 /* renegotiate event */
532 GstEvent* gst_event_new_reconfigure (void);
536 #endif /* __GST_EVENT_H__ */