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
44 * #GstEventTypeFlags indicate the aspects of the different #GstEventType
45 * values. You can get the type flags of a #GstEventType with the
46 * gst_event_type_get_flags() function.
49 GST_EVENT_TYPE_UPSTREAM = 1 << 0,
50 GST_EVENT_TYPE_DOWNSTREAM = 1 << 1,
51 GST_EVENT_TYPE_SERIALIZED = 1 << 2
55 * GST_EVENT_TYPE_BOTH:
57 * The same thing as #GST_EVENT_TYPE_UPSTREAM | #GST_EVENT_TYPE_DOWNSTREAM.
59 #define GST_EVENT_TYPE_BOTH \
60 (GST_EVENT_TYPE_UPSTREAM | GST_EVENT_TYPE_DOWNSTREAM)
62 #define GST_EVENT_TYPE_SHIFT 4
65 * GST_EVENT_MAKE_TYPE:
66 * @num: the event number to create
67 * @flags: the event flags
69 * when making custom event types, use this macro with the num and
72 #define GST_EVENT_MAKE_TYPE(num,flags) \
73 (((num) << GST_EVENT_TYPE_SHIFT) | (flags))
75 #define FLAG(name) GST_EVENT_TYPE_##name
79 * @GST_EVENT_UNKNOWN: unknown event.
80 * @GST_EVENT_FLUSH_START: Start a flush operation. This event clears all data
81 * from the pipeline and unblock all streaming threads.
82 * @GST_EVENT_FLUSH_STOP: Stop a flush operation. This event resets the
83 * running-time of the pipeline.
84 * @GST_EVENT_EOS: End-Of-Stream. No more data is to be expected to follow
85 * without a NEWSEGMENT event.
86 * @GST_EVENT_NEWSEGMENT: A new media segment follows in the dataflow. The
87 * segment events contains information for clipping buffers and
88 * converting buffer timestamps to running-time and
90 * @GST_EVENT_TAG: A new set of metadata tags has been found in the stream.
91 * @GST_EVENT_BUFFERSIZE: Notification of buffering requirements. Currently not
93 * @GST_EVENT_SINK_MESSAGE: An event that sinks turn into a message. Used to
94 * send messages that should be emitted in sync with
96 * @GST_EVENT_QOS: A quality message. Used to indicate to upstream elements
97 * that the downstream elements are being starved of or
99 * @GST_EVENT_SEEK: A request for a new playback position and rate.
100 * @GST_EVENT_NAVIGATION: Navigation events are usually used for communicating
101 * user requests, such as mouse or keyboard movements,
102 * to upstream elements.
103 * @GST_EVENT_LATENCY: Notification of new latency adjustment. Sinks will use
104 * the latency information to adjust their synchronisation.
106 * @GST_EVENT_STEP: A request for stepping through the media. Sinks will usually
107 * execute the step operation. Since: 0.10.24
108 * @GST_EVENT_CUSTOM_UPSTREAM: Upstream custom event
109 * @GST_EVENT_CUSTOM_DOWNSTREAM: Downstream custom event that travels in the
111 * @GST_EVENT_CUSTOM_DOWNSTREAM_OOB: Custom out-of-band downstream event.
112 * @GST_EVENT_CUSTOM_BOTH: Custom upstream or downstream event.
113 * In-band when travelling downstream.
114 * @GST_EVENT_CUSTOM_BOTH_OOB: Custom upstream or downstream out-of-band event.
116 * #GstEventType lists the standard event types that can be sent in a pipeline.
118 * The custom event types can be used for private messages between elements
119 * that can't be expressed using normal
120 * GStreamer buffer passing semantics. Custom events carry an arbitrary
122 * Specific custom events are distinguished by the name of the structure.
124 /* NOTE: keep in sync with quark registration in gstevent.c */
126 GST_EVENT_UNKNOWN = GST_EVENT_MAKE_TYPE (0, 0),
127 /* bidirectional events */
128 GST_EVENT_FLUSH_START = GST_EVENT_MAKE_TYPE (1, FLAG(BOTH)),
129 GST_EVENT_FLUSH_STOP = GST_EVENT_MAKE_TYPE (2, FLAG(BOTH) | FLAG(SERIALIZED)),
130 /* downstream serialized events */
131 GST_EVENT_EOS = GST_EVENT_MAKE_TYPE (5, FLAG(DOWNSTREAM) | FLAG(SERIALIZED)),
132 GST_EVENT_NEWSEGMENT = GST_EVENT_MAKE_TYPE (6, FLAG(DOWNSTREAM) | FLAG(SERIALIZED)),
133 GST_EVENT_TAG = GST_EVENT_MAKE_TYPE (7, FLAG(DOWNSTREAM) | FLAG(SERIALIZED)),
134 GST_EVENT_BUFFERSIZE = GST_EVENT_MAKE_TYPE (8, FLAG(DOWNSTREAM) | FLAG(SERIALIZED)),
135 GST_EVENT_SINK_MESSAGE = GST_EVENT_MAKE_TYPE (9, FLAG(DOWNSTREAM) | FLAG(SERIALIZED)),
136 /* upstream events */
137 GST_EVENT_QOS = GST_EVENT_MAKE_TYPE (15, FLAG(UPSTREAM)),
138 GST_EVENT_SEEK = GST_EVENT_MAKE_TYPE (16, FLAG(UPSTREAM)),
139 GST_EVENT_NAVIGATION = GST_EVENT_MAKE_TYPE (17, FLAG(UPSTREAM)),
140 GST_EVENT_LATENCY = GST_EVENT_MAKE_TYPE (18, FLAG(UPSTREAM)),
141 GST_EVENT_STEP = GST_EVENT_MAKE_TYPE (19, FLAG(UPSTREAM)),
143 /* custom events start here */
144 GST_EVENT_CUSTOM_UPSTREAM = GST_EVENT_MAKE_TYPE (32, FLAG(UPSTREAM)),
145 GST_EVENT_CUSTOM_DOWNSTREAM = GST_EVENT_MAKE_TYPE (32, FLAG(DOWNSTREAM) | FLAG(SERIALIZED)),
146 GST_EVENT_CUSTOM_DOWNSTREAM_OOB = GST_EVENT_MAKE_TYPE (32, FLAG(DOWNSTREAM)),
147 GST_EVENT_CUSTOM_BOTH = GST_EVENT_MAKE_TYPE (32, FLAG(BOTH) | FLAG(SERIALIZED)),
148 GST_EVENT_CUSTOM_BOTH_OOB = GST_EVENT_MAKE_TYPE (32, FLAG(BOTH))
153 * GST_EVENT_TRACE_NAME:
155 * The name used for memory allocation tracing
157 #define GST_EVENT_TRACE_NAME "GstEvent"
159 typedef struct _GstEvent GstEvent;
160 typedef struct _GstEventClass GstEventClass;
162 #define GST_TYPE_EVENT (gst_event_get_type())
163 #define GST_IS_EVENT(obj) (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GST_TYPE_EVENT))
164 #define GST_IS_EVENT_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GST_TYPE_EVENT))
165 #define GST_EVENT_GET_CLASS(obj) (G_TYPE_INSTANCE_GET_CLASS ((obj), GST_TYPE_EVENT, GstEventClass))
166 #define GST_EVENT(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), GST_TYPE_EVENT, GstEvent))
167 #define GST_EVENT_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST ((klass), GST_TYPE_EVENT, GstEventClass))
168 #define GST_EVENT_CAST(obj) ((GstEvent *)(obj))
172 * @event: the event to query
174 * Get the #GstEventType of the event.
176 #define GST_EVENT_TYPE(event) (GST_EVENT_CAST(event)->type)
179 * GST_EVENT_TYPE_NAME:
180 * @event: the event to query
182 * Get a constant string representation of the #GstEventType of the event.
184 #define GST_EVENT_TYPE_NAME(event) (gst_event_type_get_name(GST_EVENT_TYPE(event)))
187 * GST_EVENT_TIMESTAMP:
188 * @event: the event to query
190 * Get the #GstClockTime timestamp of the event. This is the time when the event
193 #define GST_EVENT_TIMESTAMP(event) (GST_EVENT_CAST(event)->timestamp)
197 * @event: the event to query
199 * The source #GstObject that generated this event.
201 #define GST_EVENT_SRC(event) (GST_EVENT_CAST(event)->src)
204 * GST_EVENT_IS_UPSTREAM:
205 * @ev: the event to query
207 * Check if an event can travel upstream.
209 #define GST_EVENT_IS_UPSTREAM(ev) !!(GST_EVENT_TYPE (ev) & GST_EVENT_TYPE_UPSTREAM)
211 * GST_EVENT_IS_DOWNSTREAM:
212 * @ev: the event to query
214 * Check if an event can travel downstream.
216 #define GST_EVENT_IS_DOWNSTREAM(ev) !!(GST_EVENT_TYPE (ev) & GST_EVENT_TYPE_DOWNSTREAM)
218 * GST_EVENT_IS_SERIALIZED:
219 * @ev: the event to query
221 * Check if an event is serialized with the data stream.
223 #define GST_EVENT_IS_SERIALIZED(ev) !!(GST_EVENT_TYPE (ev) & GST_EVENT_TYPE_SERIALIZED)
227 * @old_event: pointer to a pointer to a #GstEvent to be replaced.
228 * @new_event: pointer to a #GstEvent that will replace the event pointed to
231 * Modifies a pointer to a #GstEvent to point to a different #GstEvent. The
232 * modification is done atomically (so this is useful for ensuring thread safety
233 * in some cases), and the reference counts are updated appropriately (the old
234 * event is unreffed, the new one is reffed).
236 * Either @new_event or the #GstEvent pointed to by @old_event may be NULL.
240 #define gst_event_replace(old_event,new_event) \
241 gst_mini_object_replace ((GstMiniObject **)(old_event), GST_MINI_OBJECT_CAST (new_event))
245 * @GST_SEEK_TYPE_NONE: no change in position is required
246 * @GST_SEEK_TYPE_CUR: change relative to currently configured segment. This
247 * can't be used to seek relative to the current playback position - do a
248 * position query, calculate the desired position and then do an absolute
249 * position seek instead if that's what you want to do.
250 * @GST_SEEK_TYPE_SET: absolute position is requested
251 * @GST_SEEK_TYPE_END: relative position to duration is requested
253 * The different types of seek events. When constructing a seek event with
254 * gst_event_new_seek(), a format, a seek method and optional flags are to
255 * be provided. The seek event is then inserted into the graph with
256 * gst_pad_send_event() or gst_element_send_event().
260 GST_SEEK_TYPE_NONE = 0,
261 GST_SEEK_TYPE_CUR = 1,
262 GST_SEEK_TYPE_SET = 2,
263 GST_SEEK_TYPE_END = 3
268 * @GST_SEEK_FLAG_NONE: no flag
269 * @GST_SEEK_FLAG_FLUSH: flush pipeline
270 * @GST_SEEK_FLAG_ACCURATE: accurate position is requested, this might
271 * be considerably slower for some formats.
272 * @GST_SEEK_FLAG_KEY_UNIT: seek to the nearest keyframe. This might be
273 * faster but less accurate.
274 * @GST_SEEK_FLAG_SEGMENT: perform a segment seek.
275 * @GST_SEEK_FLAG_SKIP: when doing fast foward or fast reverse playback, allow
276 * elements to skip frames instead of generating all
277 * frames. Since 0.10.22.
279 * Flags to be used with gst_element_seek() or gst_event_new_seek(). All flags
280 * can be used together.
282 * A non flushing seek might take some time to perform as the currently
283 * playing data in the pipeline will not be cleared.
285 * An accurate seek might be slower for formats that don't have any indexes
286 * or timestamp markers in the stream. Specifying this flag might require a
287 * complete scan of the file in those cases.
289 * When performing a segment seek: after the playback of the segment completes,
290 * no EOS will be emmited by the element that performed the seek, but a
291 * #GST_MESSAGE_SEGMENT_DONE message will be posted on the bus by the element.
292 * When this message is posted, it is possible to send a new seek event to
293 * continue playback. With this seek method it is possible to perform seemless
294 * looping or simple linear editing.
296 * When doing fast forward (rate > 1.0) or fast reverse (rate < -1.0) trickmode
297 * playback, the @GST_SEEK_FLAG_SKIP flag can be used to instruct decoders
298 * and demuxers to adjust the playback rate by skipping frames. This can improve
299 * performance and decrease CPU usage because not all frames need to be decoded.
302 GST_SEEK_FLAG_NONE = 0,
303 GST_SEEK_FLAG_FLUSH = (1 << 0),
304 GST_SEEK_FLAG_ACCURATE = (1 << 1),
305 GST_SEEK_FLAG_KEY_UNIT = (1 << 2),
306 GST_SEEK_FLAG_SEGMENT = (1 << 3),
307 GST_SEEK_FLAG_SKIP = (1 << 4)
312 * @mini_object: the parent structure
313 * @type: the #GstEventType of the event
314 * @timestamp: the timestamp of the event
315 * @src: the src of the event
316 * @structure: the #GstStructure containing the event info.
321 GstMiniObject mini_object;
323 /*< public >*/ /* with COW */
328 GstStructure *structure;
333 gpointer _gst_reserved;
337 struct _GstEventClass {
338 GstMiniObjectClass mini_object_class;
341 gpointer _gst_reserved[GST_PADDING];
344 const gchar* gst_event_type_get_name (GstEventType type);
345 GQuark gst_event_type_to_quark (GstEventType type);
347 gst_event_type_get_flags (GstEventType type);
350 GType gst_event_get_type (void);
355 * @event: The event to refcount
357 * Increase the refcount of this event.
359 * Returns: @event (for convenience when doing assignments)
361 #ifdef _FOOL_GTK_DOC_
362 G_INLINE_FUNC GstEvent * gst_event_ref (GstEvent * event);
365 static inline GstEvent *
366 gst_event_ref (GstEvent * event)
368 return (GstEvent *) gst_mini_object_ref (GST_MINI_OBJECT_CAST (event));
373 * @event: The event to refcount
375 * Decrease the refcount of an event, freeing it if the refcount reaches 0.
377 #ifdef _FOOL_GTK_DOC_
378 G_INLINE_FUNC void gst_event_unref (GstEvent * event);
382 gst_event_unref (GstEvent * event)
384 gst_mini_object_unref (GST_MINI_OBJECT_CAST (event));
390 * @event: The event to copy
392 * Copy the event using the event specific copy function.
394 * Returns: the new event
396 #ifdef _FOOL_GTK_DOC_
397 G_INLINE_FUNC GstEvent * gst_event_copy (const GstEvent * event);
400 static inline GstEvent *
401 gst_event_copy (const GstEvent * event)
403 return GST_EVENT_CAST (gst_mini_object_copy (GST_MINI_OBJECT_CAST (event)));
408 GstEvent* gst_event_new_custom (GstEventType type, GstStructure *structure);
411 gst_event_get_structure (GstEvent *event);
413 gboolean gst_event_has_name (GstEvent *event, const gchar *name);
415 /* identifiers for events and messages */
416 guint32 gst_event_get_seqnum (GstEvent *event);
417 void gst_event_set_seqnum (GstEvent *event, guint32 seqnum);
420 GstEvent * gst_event_new_flush_start (void);
421 GstEvent * gst_event_new_flush_stop (void);
424 GstEvent * gst_event_new_eos (void);
426 /* newsegment events */
427 GstEvent* gst_event_new_new_segment (gboolean update, gdouble rate,
429 gint64 start, gint64 stop,
431 GstEvent* gst_event_new_new_segment_full (gboolean update, gdouble rate,
432 gdouble applied_rate,
434 gint64 start, gint64 stop,
436 void gst_event_parse_new_segment (GstEvent *event,
440 gint64 *start, gint64 *stop,
442 void gst_event_parse_new_segment_full (GstEvent *event,
445 gdouble *applied_rate,
447 gint64 *start, gint64 *stop,
451 GstEvent* gst_event_new_tag (GstTagList *taglist);
452 void gst_event_parse_tag (GstEvent *event, GstTagList **taglist);
455 GstEvent * gst_event_new_buffer_size (GstFormat format, gint64 minsize, gint64 maxsize,
457 void gst_event_parse_buffer_size (GstEvent *event, GstFormat *format, gint64 *minsize,
458 gint64 *maxsize, gboolean *async);
461 GstEvent* gst_event_new_qos (gdouble proportion, GstClockTimeDiff diff,
462 GstClockTime timestamp);
463 void gst_event_parse_qos (GstEvent *event, gdouble *proportion, GstClockTimeDiff *diff,
464 GstClockTime *timestamp);
466 GstEvent* gst_event_new_seek (gdouble rate, GstFormat format, GstSeekFlags flags,
467 GstSeekType start_type, gint64 start,
468 GstSeekType stop_type, gint64 stop);
469 void gst_event_parse_seek (GstEvent *event, gdouble *rate, GstFormat *format,
471 GstSeekType *start_type, gint64 *start,
472 GstSeekType *stop_type, gint64 *stop);
473 /* navigation event */
474 GstEvent* gst_event_new_navigation (GstStructure *structure);
477 GstEvent* gst_event_new_latency (GstClockTime latency);
478 void gst_event_parse_latency (GstEvent *event, GstClockTime *latency);
481 GstEvent* gst_event_new_step (GstFormat format, guint64 amount, gdouble rate,
482 gboolean flush, gboolean intermediate);
483 void gst_event_parse_step (GstEvent *event, GstFormat *format, guint64 *amount,
484 gdouble *rate, gboolean *flush, gboolean *intermediate);
488 #endif /* __GST_EVENT_H__ */