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
97 * @GST_EVENT_QOS: A quality message. Used to indicate to upstream elements
98 * that the downstream elements should adjust their processing
100 * @GST_EVENT_SEEK: A request for a new playback position and rate.
101 * @GST_EVENT_NAVIGATION: Navigation events are usually used for communicating
102 * user requests, such as mouse or keyboard movements,
103 * to upstream elements.
104 * @GST_EVENT_LATENCY: Notification of new latency adjustment. Sinks will use
105 * the latency information to adjust their synchronisation.
107 * @GST_EVENT_STEP: A request for stepping through the media. Sinks will usually
108 * execute the step operation. Since: 0.10.24
109 * @GST_EVENT_CUSTOM_UPSTREAM: Upstream custom event
110 * @GST_EVENT_CUSTOM_DOWNSTREAM: Downstream custom event that travels in the
112 * @GST_EVENT_CUSTOM_DOWNSTREAM_OOB: Custom out-of-band downstream event.
113 * @GST_EVENT_CUSTOM_BOTH: Custom upstream or downstream event.
114 * In-band when travelling downstream.
115 * @GST_EVENT_CUSTOM_BOTH_OOB: Custom upstream or downstream out-of-band event.
117 * #GstEventType lists the standard event types that can be sent in a pipeline.
119 * The custom event types can be used for private messages between elements
120 * that can't be expressed using normal
121 * GStreamer buffer passing semantics. Custom events carry an arbitrary
123 * Specific custom events are distinguished by the name of the structure.
125 /* NOTE: keep in sync with quark registration in gstevent.c */
127 GST_EVENT_UNKNOWN = GST_EVENT_MAKE_TYPE (0, 0),
128 /* bidirectional events */
129 GST_EVENT_FLUSH_START = GST_EVENT_MAKE_TYPE (1, FLAG(BOTH)),
130 GST_EVENT_FLUSH_STOP = GST_EVENT_MAKE_TYPE (2, FLAG(BOTH) | FLAG(SERIALIZED)),
131 /* downstream serialized events */
132 GST_EVENT_EOS = GST_EVENT_MAKE_TYPE (5, FLAG(DOWNSTREAM) | FLAG(SERIALIZED)),
133 GST_EVENT_NEWSEGMENT = GST_EVENT_MAKE_TYPE (6, FLAG(DOWNSTREAM) | FLAG(SERIALIZED)),
134 GST_EVENT_TAG = GST_EVENT_MAKE_TYPE (7, FLAG(DOWNSTREAM) | FLAG(SERIALIZED)),
135 GST_EVENT_BUFFERSIZE = GST_EVENT_MAKE_TYPE (8, FLAG(DOWNSTREAM) | FLAG(SERIALIZED)),
136 GST_EVENT_SINK_MESSAGE = GST_EVENT_MAKE_TYPE (9, FLAG(DOWNSTREAM) | FLAG(SERIALIZED)),
137 /* upstream events */
138 GST_EVENT_QOS = GST_EVENT_MAKE_TYPE (15, FLAG(UPSTREAM)),
139 GST_EVENT_SEEK = GST_EVENT_MAKE_TYPE (16, FLAG(UPSTREAM)),
140 GST_EVENT_NAVIGATION = GST_EVENT_MAKE_TYPE (17, FLAG(UPSTREAM)),
141 GST_EVENT_LATENCY = GST_EVENT_MAKE_TYPE (18, FLAG(UPSTREAM)),
142 GST_EVENT_STEP = GST_EVENT_MAKE_TYPE (19, FLAG(UPSTREAM)),
144 /* custom events start here */
145 GST_EVENT_CUSTOM_UPSTREAM = GST_EVENT_MAKE_TYPE (32, FLAG(UPSTREAM)),
146 GST_EVENT_CUSTOM_DOWNSTREAM = GST_EVENT_MAKE_TYPE (32, FLAG(DOWNSTREAM) | FLAG(SERIALIZED)),
147 GST_EVENT_CUSTOM_DOWNSTREAM_OOB = GST_EVENT_MAKE_TYPE (32, FLAG(DOWNSTREAM)),
148 GST_EVENT_CUSTOM_BOTH = GST_EVENT_MAKE_TYPE (32, FLAG(BOTH) | FLAG(SERIALIZED)),
149 GST_EVENT_CUSTOM_BOTH_OOB = GST_EVENT_MAKE_TYPE (32, FLAG(BOTH))
154 * GST_EVENT_TRACE_NAME:
156 * The name used for memory allocation tracing
158 #define GST_EVENT_TRACE_NAME "GstEvent"
160 typedef struct _GstEvent GstEvent;
162 #define GST_TYPE_EVENT (gst_event_get_type())
163 #define GST_IS_EVENT(obj) (GST_IS_MINI_OBJECT_TYPE (obj, GST_TYPE_EVENT))
164 #define GST_EVENT(obj) ((GstEvent *)(obj))
165 #define GST_EVENT_CAST(obj) ((GstEvent *)(obj))
169 * @event: the event to query
171 * Get the #GstEventType of the event.
173 #define GST_EVENT_TYPE(event) (GST_EVENT_CAST(event)->type)
176 * GST_EVENT_TYPE_NAME:
177 * @event: the event to query
179 * Get a constant string representation of the #GstEventType of the event.
181 #define GST_EVENT_TYPE_NAME(event) (gst_event_type_get_name(GST_EVENT_TYPE(event)))
184 * GST_EVENT_TIMESTAMP:
185 * @event: the event to query
187 * Get the #GstClockTime timestamp of the event. This is the time when the event
190 #define GST_EVENT_TIMESTAMP(event) (GST_EVENT_CAST(event)->timestamp)
194 * @event: the event to query
196 * The source #GstObject that generated this event.
198 #define GST_EVENT_SRC(event) (GST_EVENT_CAST(event)->src)
202 * @event: the event to query
204 * The sequence number of @event.
206 #define GST_EVENT_SEQNUM(event) (GST_EVENT_CAST(event)->seqnum)
209 * GST_EVENT_IS_UPSTREAM:
210 * @ev: the event to query
212 * Check if an event can travel upstream.
214 #define GST_EVENT_IS_UPSTREAM(ev) !!(GST_EVENT_TYPE (ev) & GST_EVENT_TYPE_UPSTREAM)
216 * GST_EVENT_IS_DOWNSTREAM:
217 * @ev: the event to query
219 * Check if an event can travel downstream.
221 #define GST_EVENT_IS_DOWNSTREAM(ev) !!(GST_EVENT_TYPE (ev) & GST_EVENT_TYPE_DOWNSTREAM)
223 * GST_EVENT_IS_SERIALIZED:
224 * @ev: the event to query
226 * Check if an event is serialized with the data stream.
228 #define GST_EVENT_IS_SERIALIZED(ev) !!(GST_EVENT_TYPE (ev) & GST_EVENT_TYPE_SERIALIZED)
232 * @old_event: (inout) (transfer full): pointer to a pointer to a #GstEvent
234 * @new_event: (allow-none) (transfer none): pointer to a #GstEvent that will
235 * replace the event pointed to by @old_event.
237 * Modifies a pointer to a #GstEvent to point to a different #GstEvent. The
238 * modification is done atomically (so this is useful for ensuring thread safety
239 * in some cases), and the reference counts are updated appropriately (the old
240 * event is unreffed, the new one is reffed).
242 * Either @new_event or the #GstEvent pointed to by @old_event may be NULL.
246 #define gst_event_replace(old_event,new_event) \
247 gst_mini_object_replace ((GstMiniObject **)(old_event), GST_MINI_OBJECT_CAST (new_event))
251 * @GST_SEEK_TYPE_NONE: no change in position is required
252 * @GST_SEEK_TYPE_CUR: change relative to currently configured segment. This
253 * can't be used to seek relative to the current playback position - do a
254 * position query, calculate the desired position and then do an absolute
255 * position seek instead if that's what you want to do.
256 * @GST_SEEK_TYPE_SET: absolute position is requested
257 * @GST_SEEK_TYPE_END: relative position to duration is requested
259 * The different types of seek events. When constructing a seek event with
260 * gst_event_new_seek(), a format, a seek method and optional flags are to
261 * be provided. The seek event is then inserted into the graph with
262 * gst_pad_send_event() or gst_element_send_event().
266 GST_SEEK_TYPE_NONE = 0,
267 GST_SEEK_TYPE_CUR = 1,
268 GST_SEEK_TYPE_SET = 2,
269 GST_SEEK_TYPE_END = 3
274 * @GST_SEEK_FLAG_NONE: no flag
275 * @GST_SEEK_FLAG_FLUSH: flush pipeline
276 * @GST_SEEK_FLAG_ACCURATE: accurate position is requested, this might
277 * be considerably slower for some formats.
278 * @GST_SEEK_FLAG_KEY_UNIT: seek to the nearest keyframe. This might be
279 * faster but less accurate.
280 * @GST_SEEK_FLAG_SEGMENT: perform a segment seek.
281 * @GST_SEEK_FLAG_SKIP: when doing fast foward or fast reverse playback, allow
282 * elements to skip frames instead of generating all
283 * frames. Since 0.10.22.
285 * Flags to be used with gst_element_seek() or gst_event_new_seek(). All flags
286 * can be used together.
288 * A non flushing seek might take some time to perform as the currently
289 * playing data in the pipeline will not be cleared.
291 * An accurate seek might be slower for formats that don't have any indexes
292 * or timestamp markers in the stream. Specifying this flag might require a
293 * complete scan of the file in those cases.
295 * When performing a segment seek: after the playback of the segment completes,
296 * no EOS will be emmited by the element that performed the seek, but a
297 * #GST_MESSAGE_SEGMENT_DONE message will be posted on the bus by the element.
298 * When this message is posted, it is possible to send a new seek event to
299 * continue playback. With this seek method it is possible to perform seemless
300 * looping or simple linear editing.
302 * When doing fast forward (rate > 1.0) or fast reverse (rate < -1.0) trickmode
303 * playback, the @GST_SEEK_FLAG_SKIP flag can be used to instruct decoders
304 * and demuxers to adjust the playback rate by skipping frames. This can improve
305 * performance and decrease CPU usage because not all frames need to be decoded.
307 * Also see part-seeking.txt in the GStreamer design documentation for more
308 * details on the meaning of these flags and the behaviour expected of
309 * elements that handle them.
312 GST_SEEK_FLAG_NONE = 0,
313 GST_SEEK_FLAG_FLUSH = (1 << 0),
314 GST_SEEK_FLAG_ACCURATE = (1 << 1),
315 GST_SEEK_FLAG_KEY_UNIT = (1 << 2),
316 GST_SEEK_FLAG_SEGMENT = (1 << 3),
317 GST_SEEK_FLAG_SKIP = (1 << 4)
322 * @GST_QOS_TYPE_OVERFLOW: The QoS event type that is produced when downstream
323 * elements are producing data too quickly and the element can't keep up
324 * processing the data. Upstream should reduce their processing rate. This
325 * type is also used when buffers arrive early or in time.
326 * @GST_QOS_TYPE_UNDERFLOW: The QoS event type that is produced when downstream
327 * elements are producing data too slowly and need to speed up their processing
329 * @GST_QOS_TYPE_THROTTLE: The QoS event type that is produced when the
330 * application enabled throttling to limit the datarate.
332 * The different types of QoS events that can be given to the
333 * gst_event_new_qos_full() method.
338 GST_QOS_TYPE_OVERFLOW = 0,
339 GST_QOS_TYPE_UNDERFLOW = 1,
340 GST_QOS_TYPE_THROTTLE = 2
345 * @mini_object: the parent structure
346 * @type: the #GstEventType of the event
347 * @timestamp: the timestamp of the event
348 * @src: the src of the event
349 * @structure: the #GstStructure containing the event info.
354 GstMiniObject mini_object;
356 /*< public >*/ /* with COW */
362 GstStructure *structure;
365 gpointer _gst_reserved[GST_PADDING];
368 const gchar* gst_event_type_get_name (GstEventType type);
369 GQuark gst_event_type_to_quark (GstEventType type);
371 gst_event_type_get_flags (GstEventType type);
374 GType gst_event_get_type (void);
379 * @event: The event to refcount
381 * Increase the refcount of this event.
383 * Returns: (transfer full): @event (for convenience when doing assignments)
385 #ifdef _FOOL_GTK_DOC_
386 G_INLINE_FUNC GstEvent * gst_event_ref (GstEvent * event);
389 static inline GstEvent *
390 gst_event_ref (GstEvent * event)
392 return (GstEvent *) gst_mini_object_ref (GST_MINI_OBJECT_CAST (event));
397 * @event: (transfer full): the event to refcount
399 * Decrease the refcount of an event, freeing it if the refcount reaches 0.
401 #ifdef _FOOL_GTK_DOC_
402 G_INLINE_FUNC void gst_event_unref (GstEvent * event);
406 gst_event_unref (GstEvent * event)
408 gst_mini_object_unref (GST_MINI_OBJECT_CAST (event));
414 * @event: The event to copy
416 * Copy the event using the event specific copy function.
418 * Returns: (transfer full): the new event
420 #ifdef _FOOL_GTK_DOC_
421 G_INLINE_FUNC GstEvent * gst_event_copy (const GstEvent * event);
424 static inline GstEvent *
425 gst_event_copy (const GstEvent * event)
427 return GST_EVENT_CAST (gst_mini_object_copy (GST_MINI_OBJECT_CONST_CAST (event)));
432 GstEvent* gst_event_new_custom (GstEventType type, GstStructure *structure);
435 gst_event_get_structure (GstEvent *event);
437 gboolean gst_event_has_name (GstEvent *event, const gchar *name);
439 /* identifiers for events and messages */
440 guint32 gst_event_get_seqnum (GstEvent *event);
441 void gst_event_set_seqnum (GstEvent *event, guint32 seqnum);
444 GstEvent * gst_event_new_flush_start (void);
445 GstEvent * gst_event_new_flush_stop (void);
448 GstEvent * gst_event_new_eos (void);
450 /* newsegment events */
451 GstEvent* gst_event_new_new_segment (gboolean update, gdouble rate,
453 gint64 start, gint64 stop,
455 GstEvent* gst_event_new_new_segment_full (gboolean update, gdouble rate,
456 gdouble applied_rate,
458 gint64 start, gint64 stop,
460 void gst_event_parse_new_segment (GstEvent *event,
464 gint64 *start, gint64 *stop,
466 void gst_event_parse_new_segment_full (GstEvent *event,
469 gdouble *applied_rate,
471 gint64 *start, gint64 *stop,
475 GstEvent* gst_event_new_tag (GstTagList *taglist);
476 void gst_event_parse_tag (GstEvent *event, GstTagList **taglist);
479 GstEvent * gst_event_new_buffer_size (GstFormat format, gint64 minsize, gint64 maxsize,
481 void gst_event_parse_buffer_size (GstEvent *event, GstFormat *format, gint64 *minsize,
482 gint64 *maxsize, gboolean *async);
485 GstEvent* gst_event_new_qos (gdouble proportion, GstClockTimeDiff diff,
486 GstClockTime timestamp);
487 GstEvent* gst_event_new_qos_full (GstQOSType type, gdouble proportion,
488 GstClockTimeDiff diff, GstClockTime timestamp);
489 void gst_event_parse_qos (GstEvent *event, gdouble *proportion, GstClockTimeDiff *diff,
490 GstClockTime *timestamp);
491 void gst_event_parse_qos_full (GstEvent *event, GstQOSType *type,
492 gdouble *proportion, GstClockTimeDiff *diff,
493 GstClockTime *timestamp);
495 GstEvent* gst_event_new_seek (gdouble rate, GstFormat format, GstSeekFlags flags,
496 GstSeekType start_type, gint64 start,
497 GstSeekType stop_type, gint64 stop);
498 void gst_event_parse_seek (GstEvent *event, gdouble *rate, GstFormat *format,
500 GstSeekType *start_type, gint64 *start,
501 GstSeekType *stop_type, gint64 *stop);
502 /* navigation event */
503 GstEvent* gst_event_new_navigation (GstStructure *structure);
506 GstEvent* gst_event_new_latency (GstClockTime latency);
507 void gst_event_parse_latency (GstEvent *event, GstClockTime *latency);
510 GstEvent* gst_event_new_step (GstFormat format, guint64 amount, gdouble rate,
511 gboolean flush, gboolean intermediate);
512 void gst_event_parse_step (GstEvent *event, GstFormat *format, guint64 *amount,
513 gdouble *rate, gboolean *flush, gboolean *intermediate);
517 #endif /* __GST_EVENT_H__ */