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., 51 Franklin St, Fifth Floor,
21 * Boston, MA 02110-1301, USA.
25 #ifndef __GST_EVENT_H__
26 #define __GST_EVENT_H__
28 typedef struct _GstEvent GstEvent;
32 * @GST_EVENT_TYPE_UPSTREAM: Set if the event can travel upstream.
33 * @GST_EVENT_TYPE_DOWNSTREAM: Set if the event can travel downstream.
34 * @GST_EVENT_TYPE_SERIALIZED: Set if the event should be serialized with data
36 * @GST_EVENT_TYPE_STICKY: Set if the event is sticky on the pads.
37 * @GST_EVENT_TYPE_STICKY_MULTI: Multiple sticky events can be on a pad, each
38 * identified by the event name.
40 * #GstEventTypeFlags indicate the aspects of the different #GstEventType
41 * values. You can get the type flags of a #GstEventType with the
42 * gst_event_type_get_flags() function.
45 GST_EVENT_TYPE_UPSTREAM = 1 << 0,
46 GST_EVENT_TYPE_DOWNSTREAM = 1 << 1,
47 GST_EVENT_TYPE_SERIALIZED = 1 << 2,
48 GST_EVENT_TYPE_STICKY = 1 << 3,
49 GST_EVENT_TYPE_STICKY_MULTI = 1 << 4
53 * GST_EVENT_TYPE_BOTH:
55 * The same thing as #GST_EVENT_TYPE_UPSTREAM | #GST_EVENT_TYPE_DOWNSTREAM.
57 #define GST_EVENT_TYPE_BOTH \
58 (GST_EVENT_TYPE_UPSTREAM | GST_EVENT_TYPE_DOWNSTREAM)
60 #define GST_EVENT_NUM_SHIFT (8)
63 * GST_EVENT_MAKE_TYPE:
64 * @num: the event number to create
65 * @flags: the event flags
67 * when making custom event types, use this macro with the num and
70 #define GST_EVENT_MAKE_TYPE(num,flags) \
71 (((num) << GST_EVENT_NUM_SHIFT) | (flags))
73 #define FLAG(name) GST_EVENT_TYPE_##name
77 * @GST_EVENT_UNKNOWN: unknown event.
78 * @GST_EVENT_FLUSH_START: Start a flush operation. This event clears all data
79 * from the pipeline and unblock all streaming threads.
80 * @GST_EVENT_FLUSH_STOP: Stop a flush operation. This event resets the
81 * running-time of the pipeline.
82 * @GST_EVENT_STREAM_START: Event to mark the start of a new stream. Sent before any
83 * other serialized event and only sent at the start of a new stream,
84 * not after flushing seeks.
85 * @GST_EVENT_CAPS: #GstCaps event. Notify the pad of a new media type.
86 * @GST_EVENT_SEGMENT: 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_EOS: End-Of-Stream. No more data is to be expected to follow
97 * without a SEGMENT event.
98 * @GST_EVENT_SEGMENT_DONE: Marks the end of a segment playback.
99 * @GST_EVENT_GAP: Marks a gap in the datastream.
100 * @GST_EVENT_TOC: An event which indicates that a new table of contents (TOC)
101 * was found or updated.
102 * @GST_EVENT_QOS: A quality message. Used to indicate to upstream elements
103 * that the downstream elements should adjust their processing
105 * @GST_EVENT_SEEK: A request for a new playback position and rate.
106 * @GST_EVENT_NAVIGATION: Navigation events are usually used for communicating
107 * user requests, such as mouse or keyboard movements,
108 * to upstream elements.
109 * @GST_EVENT_LATENCY: Notification of new latency adjustment. Sinks will use
110 * the latency information to adjust their synchronisation.
111 * @GST_EVENT_STEP: A request for stepping through the media. Sinks will usually
112 * execute the step operation.
113 * @GST_EVENT_RECONFIGURE: A request for upstream renegotiating caps and reconfiguring.
114 * @GST_EVENT_TOC_SELECT: A request for a new playback position based on TOC
116 * @GST_EVENT_CUSTOM_UPSTREAM: Upstream custom event
117 * @GST_EVENT_CUSTOM_DOWNSTREAM: Downstream custom event that travels in the
119 * @GST_EVENT_CUSTOM_DOWNSTREAM_OOB: Custom out-of-band downstream event.
120 * @GST_EVENT_CUSTOM_DOWNSTREAM_STICKY: Custom sticky downstream event.
121 * @GST_EVENT_CUSTOM_BOTH: Custom upstream or downstream event.
122 * In-band when travelling downstream.
123 * @GST_EVENT_CUSTOM_BOTH_OOB: Custom upstream or downstream out-of-band event.
125 * #GstEventType lists the standard event types that can be sent in a pipeline.
127 * The custom event types can be used for private messages between elements
128 * that can't be expressed using normal
129 * GStreamer buffer passing semantics. Custom events carry an arbitrary
131 * Specific custom events are distinguished by the name of the structure.
133 /* NOTE: keep in sync with quark registration in gstevent.c */
135 GST_EVENT_UNKNOWN = GST_EVENT_MAKE_TYPE (0, 0),
137 /* bidirectional events */
138 GST_EVENT_FLUSH_START = GST_EVENT_MAKE_TYPE (10, FLAG(BOTH)),
139 GST_EVENT_FLUSH_STOP = GST_EVENT_MAKE_TYPE (20, FLAG(BOTH) | FLAG(SERIALIZED)),
141 /* downstream serialized events */
142 GST_EVENT_STREAM_START = GST_EVENT_MAKE_TYPE (40, FLAG(DOWNSTREAM) | FLAG(SERIALIZED) | FLAG(STICKY)),
143 GST_EVENT_CAPS = GST_EVENT_MAKE_TYPE (50, FLAG(DOWNSTREAM) | FLAG(SERIALIZED) | FLAG(STICKY)),
144 GST_EVENT_SEGMENT = GST_EVENT_MAKE_TYPE (70, FLAG(DOWNSTREAM) | FLAG(SERIALIZED) | FLAG(STICKY)),
145 GST_EVENT_TAG = GST_EVENT_MAKE_TYPE (80, FLAG(DOWNSTREAM) | FLAG(SERIALIZED) | FLAG(STICKY) | FLAG(STICKY_MULTI)),
146 GST_EVENT_BUFFERSIZE = GST_EVENT_MAKE_TYPE (90, FLAG(DOWNSTREAM) | FLAG(SERIALIZED) | FLAG(STICKY)),
147 GST_EVENT_SINK_MESSAGE = GST_EVENT_MAKE_TYPE (100, FLAG(DOWNSTREAM) | FLAG(SERIALIZED) | FLAG(STICKY) | FLAG(STICKY_MULTI)),
148 GST_EVENT_EOS = GST_EVENT_MAKE_TYPE (110, FLAG(DOWNSTREAM) | FLAG(SERIALIZED) | FLAG(STICKY)),
149 GST_EVENT_TOC = GST_EVENT_MAKE_TYPE (120, FLAG(DOWNSTREAM) | FLAG(SERIALIZED) | FLAG(STICKY) | FLAG(STICKY_MULTI)),
151 /* non-sticky downstream serialized */
152 GST_EVENT_SEGMENT_DONE = GST_EVENT_MAKE_TYPE (150, FLAG(DOWNSTREAM) | FLAG(SERIALIZED)),
153 GST_EVENT_GAP = GST_EVENT_MAKE_TYPE (160, FLAG(DOWNSTREAM) | FLAG(SERIALIZED)),
155 /* upstream events */
156 GST_EVENT_QOS = GST_EVENT_MAKE_TYPE (190, FLAG(UPSTREAM)),
157 GST_EVENT_SEEK = GST_EVENT_MAKE_TYPE (200, FLAG(UPSTREAM)),
158 GST_EVENT_NAVIGATION = GST_EVENT_MAKE_TYPE (210, FLAG(UPSTREAM)),
159 GST_EVENT_LATENCY = GST_EVENT_MAKE_TYPE (220, FLAG(UPSTREAM)),
160 GST_EVENT_STEP = GST_EVENT_MAKE_TYPE (230, FLAG(UPSTREAM)),
161 GST_EVENT_RECONFIGURE = GST_EVENT_MAKE_TYPE (240, FLAG(UPSTREAM)),
162 GST_EVENT_TOC_SELECT = GST_EVENT_MAKE_TYPE (250, FLAG(UPSTREAM)),
164 /* custom events start here */
165 GST_EVENT_CUSTOM_UPSTREAM = GST_EVENT_MAKE_TYPE (270, FLAG(UPSTREAM)),
166 GST_EVENT_CUSTOM_DOWNSTREAM = GST_EVENT_MAKE_TYPE (280, FLAG(DOWNSTREAM) | FLAG(SERIALIZED)),
167 GST_EVENT_CUSTOM_DOWNSTREAM_OOB = GST_EVENT_MAKE_TYPE (290, FLAG(DOWNSTREAM)),
168 GST_EVENT_CUSTOM_DOWNSTREAM_STICKY = GST_EVENT_MAKE_TYPE (300, FLAG(DOWNSTREAM) | FLAG(SERIALIZED) | FLAG(STICKY) | FLAG(STICKY_MULTI)),
169 GST_EVENT_CUSTOM_BOTH = GST_EVENT_MAKE_TYPE (310, FLAG(BOTH) | FLAG(SERIALIZED)),
170 GST_EVENT_CUSTOM_BOTH_OOB = GST_EVENT_MAKE_TYPE (320, FLAG(BOTH))
174 #include <gst/gstminiobject.h>
175 #include <gst/gstformat.h>
176 #include <gst/gstobject.h>
177 #include <gst/gstclock.h>
178 #include <gst/gststructure.h>
179 #include <gst/gsttaglist.h>
180 #include <gst/gstsegment.h>
181 #include <gst/gstsegment.h>
182 #include <gst/gstmessage.h>
186 GST_EXPORT GType _gst_event_type;
188 #define GST_TYPE_EVENT (_gst_event_type)
189 #define GST_IS_EVENT(obj) (GST_IS_MINI_OBJECT_TYPE (obj, GST_TYPE_EVENT))
190 #define GST_EVENT_CAST(obj) ((GstEvent *)(obj))
191 #define GST_EVENT(obj) (GST_EVENT_CAST(obj))
195 * @event: the event to query
197 * Get the #GstEventType of the event.
199 #define GST_EVENT_TYPE(event) (GST_EVENT_CAST(event)->type)
202 * GST_EVENT_TYPE_NAME:
203 * @event: the event to query
205 * Get a constant string representation of the #GstEventType of the event.
207 #define GST_EVENT_TYPE_NAME(event) (gst_event_type_get_name(GST_EVENT_TYPE(event)))
210 * GST_EVENT_TIMESTAMP:
211 * @event: the event to query
213 * Get the #GstClockTime timestamp of the event. This is the time when the event
216 #define GST_EVENT_TIMESTAMP(event) (GST_EVENT_CAST(event)->timestamp)
220 * @event: the event to query
222 * The sequence number of @event.
224 #define GST_EVENT_SEQNUM(event) (GST_EVENT_CAST(event)->seqnum)
227 * GST_EVENT_IS_UPSTREAM:
228 * @ev: the event to query
230 * Check if an event can travel upstream.
232 #define GST_EVENT_IS_UPSTREAM(ev) !!(GST_EVENT_TYPE (ev) & GST_EVENT_TYPE_UPSTREAM)
234 * GST_EVENT_IS_DOWNSTREAM:
235 * @ev: the event to query
237 * Check if an event can travel downstream.
239 #define GST_EVENT_IS_DOWNSTREAM(ev) !!(GST_EVENT_TYPE (ev) & GST_EVENT_TYPE_DOWNSTREAM)
241 * GST_EVENT_IS_SERIALIZED:
242 * @ev: the event to query
244 * Check if an event is serialized with the data stream.
246 #define GST_EVENT_IS_SERIALIZED(ev) !!(GST_EVENT_TYPE (ev) & GST_EVENT_TYPE_SERIALIZED)
248 * GST_EVENT_IS_STICKY:
249 * @ev: the event to query
251 * Check if an event is sticky on the pads.
253 #define GST_EVENT_IS_STICKY(ev) !!(GST_EVENT_TYPE (ev) & GST_EVENT_TYPE_STICKY)
256 * gst_event_is_writable:
259 * Tests if you can safely write data into a event's structure or validly
260 * modify the seqnum and timestamp field.
262 #define gst_event_is_writable(ev) gst_mini_object_is_writable (GST_MINI_OBJECT_CAST (ev))
264 * gst_event_make_writable:
265 * @ev: (transfer full): a #GstEvent
267 * Makes a writable event from the given event. If the source event is
268 * already writable, this will simply return the same event. A copy will
269 * otherwise be made using gst_event_copy().
271 * Returns: (transfer full): a writable event which may or may not be the
274 #define gst_event_make_writable(ev) GST_EVENT_CAST (gst_mini_object_make_writable (GST_MINI_OBJECT_CAST (ev)))
277 * @old_event: (inout) (transfer full): pointer to a pointer to a #GstEvent
279 * @new_event: (allow-none) (transfer none): pointer to a #GstEvent that will
280 * replace the event pointed to by @old_event.
282 * Modifies a pointer to a #GstEvent to point to a different #GstEvent. The
283 * modification is done atomically (so this is useful for ensuring thread safety
284 * in some cases), and the reference counts are updated appropriately (the old
285 * event is unreffed, the new one is reffed).
287 * Either @new_event or the #GstEvent pointed to by @old_event may be NULL.
289 * Returns: TRUE if @new_event was different from @old_event
291 #ifdef _FOOL_GTK_DOC_
292 G_INLINE_FUNC gboolean gst_event_replace (GstEvent **old_event, GstEvent *new_event);
295 static inline gboolean
296 gst_event_replace (GstEvent **old_event, GstEvent *new_event)
298 return gst_mini_object_replace ((GstMiniObject **) old_event, (GstMiniObject *) new_event);
303 * @old_event: (inout) (transfer full): pointer to a pointer to a #GstEvent
306 * Atomically replace the #GstEvent pointed to by @old_event with NULL and
307 * return the original event.
309 * Returns: the #GstEvent that was in @old_event
311 #ifdef _FOOL_GTK_DOC_
312 G_INLINE_FUNC GstEvent * gst_event_steal (GstEvent **old_event);
315 static inline GstEvent *
316 gst_event_steal (GstEvent **old_event)
318 return GST_EVENT_CAST (gst_mini_object_steal ((GstMiniObject **) old_event));
323 * @old_event: (inout) (transfer full): pointer to a pointer to a #GstEvent
325 * @new_event: (allow-none) (transfer full): pointer to a #GstEvent that will
326 * replace the event pointed to by @old_event.
328 * Modifies a pointer to a #GstEvent to point to a different #GstEvent. This
329 * function is similar to gst_event_replace() except that it takes ownership of
332 * Either @new_event or the #GstEvent pointed to by @old_event may be NULL.
334 * Returns: TRUE if @new_event was different from @old_event
336 #ifdef _FOOL_GTK_DOC_
337 G_INLINE_FUNC gboolean gst_event_take (GstEvent **old_event, GstEvent *new_event);
340 static inline gboolean
341 gst_event_take (GstEvent **old_event, GstEvent *new_event)
343 return gst_mini_object_take ((GstMiniObject **) old_event, (GstMiniObject *) new_event);
348 * @GST_QOS_TYPE_OVERFLOW: The QoS event type that is produced when downstream
349 * elements are producing data too quickly and the element can't keep up
350 * processing the data. Upstream should reduce their processing rate. This
351 * type is also used when buffers arrive early or in time.
352 * @GST_QOS_TYPE_UNDERFLOW: The QoS event type that is produced when downstream
353 * elements are producing data too slowly and need to speed up their processing
355 * @GST_QOS_TYPE_THROTTLE: The QoS event type that is produced when the
356 * application enabled throttling to limit the datarate.
358 * The different types of QoS events that can be given to the
359 * gst_event_new_qos() method.
362 GST_QOS_TYPE_OVERFLOW = 0,
363 GST_QOS_TYPE_UNDERFLOW = 1,
364 GST_QOS_TYPE_THROTTLE = 2
369 * @mini_object: the parent structure
370 * @type: the #GstEventType of the event
371 * @timestamp: the timestamp of the event
372 * @seqnum: the sequence number of the event
377 GstMiniObject mini_object;
379 /*< public >*/ /* with COW */
385 const gchar* gst_event_type_get_name (GstEventType type);
386 GQuark gst_event_type_to_quark (GstEventType type);
388 gst_event_type_get_flags (GstEventType type);
394 * @event: The event to refcount
396 * Increase the refcount of this event.
398 * Returns: (transfer full): @event (for convenience when doing assignments)
400 #ifdef _FOOL_GTK_DOC_
401 G_INLINE_FUNC GstEvent * gst_event_ref (GstEvent * event);
404 static inline GstEvent *
405 gst_event_ref (GstEvent * event)
407 return (GstEvent *) gst_mini_object_ref (GST_MINI_OBJECT_CAST (event));
412 * @event: (transfer full): the event to refcount
414 * Decrease the refcount of an event, freeing it if the refcount reaches 0.
416 #ifdef _FOOL_GTK_DOC_
417 G_INLINE_FUNC void gst_event_unref (GstEvent * event);
421 gst_event_unref (GstEvent * event)
423 gst_mini_object_unref (GST_MINI_OBJECT_CAST (event));
429 * @event: The event to copy
431 * Copy the event using the event specific copy function.
433 * Returns: (transfer full): the new event
435 #ifdef _FOOL_GTK_DOC_
436 G_INLINE_FUNC GstEvent * gst_event_copy (const GstEvent * event);
439 static inline GstEvent *
440 gst_event_copy (const GstEvent * event)
442 return GST_EVENT_CAST (gst_mini_object_copy (GST_MINI_OBJECT_CONST_CAST (event)));
445 GType gst_event_get_type (void);
448 GstEvent* gst_event_new_custom (GstEventType type, GstStructure *structure) G_GNUC_MALLOC;
451 gst_event_get_structure (GstEvent *event);
452 GstStructure * gst_event_writable_structure (GstEvent *event);
454 gboolean gst_event_has_name (GstEvent *event, const gchar *name);
456 /* identifiers for events and messages */
457 guint32 gst_event_get_seqnum (GstEvent *event);
458 void gst_event_set_seqnum (GstEvent *event, guint32 seqnum);
460 /* Stream start event */
461 GstEvent * gst_event_new_stream_start (const gchar *stream_id) G_GNUC_MALLOC;
462 void gst_event_parse_stream_start (GstEvent *event, const gchar **stream_id);
465 GstEvent * gst_event_new_flush_start (void) G_GNUC_MALLOC;
467 GstEvent * gst_event_new_flush_stop (gboolean reset_time) G_GNUC_MALLOC;
468 void gst_event_parse_flush_stop (GstEvent *event, gboolean *reset_time);
471 GstEvent * gst_event_new_eos (void) G_GNUC_MALLOC;
474 GstEvent * gst_event_new_gap (GstClockTime timestamp,
475 GstClockTime duration) G_GNUC_MALLOC;
477 void gst_event_parse_gap (GstEvent * event,
478 GstClockTime * timestamp,
479 GstClockTime * duration);
482 GstEvent * gst_event_new_caps (GstCaps *caps) G_GNUC_MALLOC;
483 void gst_event_parse_caps (GstEvent *event, GstCaps **caps);
486 GstEvent* gst_event_new_segment (const GstSegment *segment) G_GNUC_MALLOC;
487 void gst_event_parse_segment (GstEvent *event, const GstSegment **segment);
488 void gst_event_copy_segment (GstEvent *event, GstSegment *segment);
491 GstEvent* gst_event_new_tag (GstTagList *taglist) G_GNUC_MALLOC;
492 void gst_event_parse_tag (GstEvent *event, GstTagList **taglist);
495 GstEvent* gst_event_new_toc (GstToc *toc, gboolean updated);
496 void gst_event_parse_toc (GstEvent *event, GstToc **toc, gboolean *updated);
500 GstEvent * gst_event_new_buffer_size (GstFormat format, gint64 minsize, gint64 maxsize,
501 gboolean async) G_GNUC_MALLOC;
502 void gst_event_parse_buffer_size (GstEvent *event, GstFormat *format, gint64 *minsize,
503 gint64 *maxsize, gboolean *async);
506 GstEvent* gst_event_new_sink_message (const gchar *name, GstMessage *msg) G_GNUC_MALLOC;
507 void gst_event_parse_sink_message (GstEvent *event, GstMessage **msg);
510 GstEvent* gst_event_new_qos (GstQOSType type, gdouble proportion,
511 GstClockTimeDiff diff, GstClockTime timestamp) G_GNUC_MALLOC;
512 void gst_event_parse_qos (GstEvent *event, GstQOSType *type,
513 gdouble *proportion, GstClockTimeDiff *diff,
514 GstClockTime *timestamp);
516 GstEvent* gst_event_new_seek (gdouble rate, GstFormat format, GstSeekFlags flags,
517 GstSeekType start_type, gint64 start,
518 GstSeekType stop_type, gint64 stop) G_GNUC_MALLOC;
519 void gst_event_parse_seek (GstEvent *event, gdouble *rate, GstFormat *format,
521 GstSeekType *start_type, gint64 *start,
522 GstSeekType *stop_type, gint64 *stop);
524 /* navigation event */
525 GstEvent* gst_event_new_navigation (GstStructure *structure) G_GNUC_MALLOC;
528 GstEvent* gst_event_new_latency (GstClockTime latency) G_GNUC_MALLOC;
529 void gst_event_parse_latency (GstEvent *event, GstClockTime *latency);
532 GstEvent* gst_event_new_step (GstFormat format, guint64 amount, gdouble rate,
533 gboolean flush, gboolean intermediate) G_GNUC_MALLOC;
534 void gst_event_parse_step (GstEvent *event, GstFormat *format, guint64 *amount,
535 gdouble *rate, gboolean *flush, gboolean *intermediate);
537 /* renegotiate event */
538 GstEvent* gst_event_new_reconfigure (void) G_GNUC_MALLOC;
540 /* TOC select event */
541 GstEvent* gst_event_new_toc_select (const gchar *uid) G_GNUC_MALLOC;
542 void gst_event_parse_toc_select (GstEvent *event, gchar **uid);
544 /* segment-done event */
545 GstEvent* gst_event_new_segment_done (GstFormat format, gint64 position) G_GNUC_MALLOC;
546 void gst_event_parse_segment_done (GstEvent *event, GstFormat *format, gint64 *position);
550 #endif /* __GST_EVENT_H__ */