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 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 * @idx: the index in the sticky array
66 * @flags: the event flags
68 * when making custom event types, use this macro with the num and
71 #define GST_EVENT_MAKE_TYPE(num,flags) \
72 (((num) << GST_EVENT_NUM_SHIFT) | (flags))
74 #define FLAG(name) GST_EVENT_TYPE_##name
78 * @GST_EVENT_UNKNOWN: unknown event.
79 * @GST_EVENT_FLUSH_START: Start a flush operation. This event clears all data
80 * from the pipeline and unblock all streaming threads.
81 * @GST_EVENT_FLUSH_STOP: Stop a flush operation. This event resets the
82 * running-time of the pipeline.
83 * @GST_EVENT_CAPS: #GstCaps event. Notify the pad of a new media type.
84 * @GST_EVENT_SEGMENT: A new media segment follows in the dataflow. The
85 * segment events contains information for clipping buffers and
86 * converting buffer timestamps to running-time and
88 * @GST_EVENT_TAG: A new set of metadata tags has been found in the stream.
89 * @GST_EVENT_BUFFERSIZE: Notification of buffering requirements. Currently not
91 * @GST_EVENT_SINK_MESSAGE: An event that sinks turn into a message. Used to
92 * send messages that should be emitted in sync with
95 * @GST_EVENT_EOS: End-Of-Stream. No more data is to be expected to follow
96 * without a SEGMENT event.
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_RECONFIGURE: A request for upstream renegotiating caps and reconfiguring.
111 * @GST_EVENT_CUSTOM_UPSTREAM: Upstream custom event
112 * @GST_EVENT_CUSTOM_DOWNSTREAM: Downstream custom event that travels in the
114 * @GST_EVENT_CUSTOM_DOWNSTREAM_OOB: Custom out-of-band downstream event.
115 * @GST_EVENT_CUSTOM_DOWNSTREAM_STICKY: Custom sticky downstream event.
116 * @GST_EVENT_CUSTOM_BOTH: Custom upstream or downstream event.
117 * In-band when travelling downstream.
118 * @GST_EVENT_CUSTOM_BOTH_OOB: Custom upstream or downstream out-of-band event.
120 * #GstEventType lists the standard event types that can be sent in a pipeline.
122 * The custom event types can be used for private messages between elements
123 * that can't be expressed using normal
124 * GStreamer buffer passing semantics. Custom events carry an arbitrary
126 * Specific custom events are distinguished by the name of the structure.
128 /* NOTE: keep in sync with quark registration in gstevent.c */
130 GST_EVENT_UNKNOWN = GST_EVENT_MAKE_TYPE (0, 0),
131 /* bidirectional events */
132 GST_EVENT_FLUSH_START = GST_EVENT_MAKE_TYPE (10, FLAG(BOTH)),
133 GST_EVENT_FLUSH_STOP = GST_EVENT_MAKE_TYPE (20, FLAG(BOTH) | FLAG(SERIALIZED)),
134 /* downstream serialized events */
135 GST_EVENT_CAPS = GST_EVENT_MAKE_TYPE (40, FLAG(DOWNSTREAM) | FLAG(SERIALIZED) | FLAG(STICKY)),
136 GST_EVENT_SEGMENT = GST_EVENT_MAKE_TYPE (50, FLAG(DOWNSTREAM) | FLAG(SERIALIZED) | FLAG(STICKY)),
137 GST_EVENT_TAG = GST_EVENT_MAKE_TYPE (60, FLAG(DOWNSTREAM) | FLAG(SERIALIZED) | FLAG(STICKY) | FLAG(STICKY_MULTI)),
138 GST_EVENT_BUFFERSIZE = GST_EVENT_MAKE_TYPE (70, FLAG(DOWNSTREAM) | FLAG(SERIALIZED) | FLAG(STICKY)),
139 GST_EVENT_SINK_MESSAGE = GST_EVENT_MAKE_TYPE (80, FLAG(DOWNSTREAM) | FLAG(SERIALIZED) | FLAG(STICKY) | FLAG(STICKY_MULTI)),
140 GST_EVENT_EOS = GST_EVENT_MAKE_TYPE (90, FLAG(DOWNSTREAM) | FLAG(SERIALIZED) | FLAG(STICKY)),
142 /* upstream events */
143 GST_EVENT_QOS = GST_EVENT_MAKE_TYPE (120, FLAG(UPSTREAM)),
144 GST_EVENT_SEEK = GST_EVENT_MAKE_TYPE (130, FLAG(UPSTREAM)),
145 GST_EVENT_NAVIGATION = GST_EVENT_MAKE_TYPE (140, FLAG(UPSTREAM)),
146 GST_EVENT_LATENCY = GST_EVENT_MAKE_TYPE (150, FLAG(UPSTREAM)),
147 GST_EVENT_STEP = GST_EVENT_MAKE_TYPE (160, FLAG(UPSTREAM)),
148 GST_EVENT_RECONFIGURE = GST_EVENT_MAKE_TYPE (170, FLAG(UPSTREAM)),
150 /* custom events start here */
151 GST_EVENT_CUSTOM_UPSTREAM = GST_EVENT_MAKE_TYPE (220, FLAG(UPSTREAM)),
152 GST_EVENT_CUSTOM_DOWNSTREAM = GST_EVENT_MAKE_TYPE (220, FLAG(DOWNSTREAM) | FLAG(SERIALIZED)),
153 GST_EVENT_CUSTOM_DOWNSTREAM_OOB = GST_EVENT_MAKE_TYPE (220, FLAG(DOWNSTREAM)),
154 GST_EVENT_CUSTOM_DOWNSTREAM_STICKY = GST_EVENT_MAKE_TYPE (220, FLAG(DOWNSTREAM) | FLAG(SERIALIZED) | FLAG(STICKY) | FLAG(STICKY_MULTI)),
155 GST_EVENT_CUSTOM_BOTH = GST_EVENT_MAKE_TYPE (220, FLAG(BOTH) | FLAG(SERIALIZED)),
156 GST_EVENT_CUSTOM_BOTH_OOB = GST_EVENT_MAKE_TYPE (220, FLAG(BOTH))
160 #include <gst/gstminiobject.h>
161 #include <gst/gstformat.h>
162 #include <gst/gstobject.h>
163 #include <gst/gstclock.h>
164 #include <gst/gststructure.h>
165 #include <gst/gsttaglist.h>
166 #include <gst/gstsegment.h>
167 #include <gst/gstsegment.h>
168 #include <gst/gstmessage.h>
172 GST_EXPORT GType _gst_event_type;
174 #define GST_TYPE_EVENT (_gst_event_type)
175 #define GST_IS_EVENT(obj) (GST_IS_MINI_OBJECT_TYPE (obj, GST_TYPE_EVENT))
176 #define GST_EVENT_CAST(obj) ((GstEvent *)(obj))
177 #define GST_EVENT(obj) (GST_EVENT_CAST(obj))
180 * GST_EVENT_TRACE_NAME:
182 * The name used for memory allocation tracing
184 #define GST_EVENT_TRACE_NAME "GstEvent"
188 * @event: the event to query
190 * Get the #GstEventType of the event.
192 #define GST_EVENT_TYPE(event) (GST_EVENT_CAST(event)->type)
195 * GST_EVENT_TYPE_NAME:
196 * @event: the event to query
198 * Get a constant string representation of the #GstEventType of the event.
200 #define GST_EVENT_TYPE_NAME(event) (gst_event_type_get_name(GST_EVENT_TYPE(event)))
203 * GST_EVENT_TIMESTAMP:
204 * @event: the event to query
206 * Get the #GstClockTime timestamp of the event. This is the time when the event
209 #define GST_EVENT_TIMESTAMP(event) (GST_EVENT_CAST(event)->timestamp)
213 * @event: the event to query
215 * The sequence number of @event.
217 #define GST_EVENT_SEQNUM(event) (GST_EVENT_CAST(event)->seqnum)
220 * GST_EVENT_IS_UPSTREAM:
221 * @ev: the event to query
223 * Check if an event can travel upstream.
225 #define GST_EVENT_IS_UPSTREAM(ev) !!(GST_EVENT_TYPE (ev) & GST_EVENT_TYPE_UPSTREAM)
227 * GST_EVENT_IS_DOWNSTREAM:
228 * @ev: the event to query
230 * Check if an event can travel downstream.
232 #define GST_EVENT_IS_DOWNSTREAM(ev) !!(GST_EVENT_TYPE (ev) & GST_EVENT_TYPE_DOWNSTREAM)
234 * GST_EVENT_IS_SERIALIZED:
235 * @ev: the event to query
237 * Check if an event is serialized with the data stream.
239 #define GST_EVENT_IS_SERIALIZED(ev) !!(GST_EVENT_TYPE (ev) & GST_EVENT_TYPE_SERIALIZED)
241 * GST_EVENT_IS_STICKY:
242 * @ev: the event to query
244 * Check if an event is sticky on the pads.
246 #define GST_EVENT_IS_STICKY(ev) !!(GST_EVENT_TYPE (ev) & GST_EVENT_TYPE_STICKY)
249 * gst_event_is_writable:
252 * Tests if you can safely write data into a event's structure or validly
253 * modify the seqnum and timestamp field.
255 #define gst_event_is_writable(ev) gst_mini_object_is_writable (GST_MINI_OBJECT_CAST (ev))
257 * gst_event_make_writable:
258 * @ev: (transfer full): a #GstEvent
260 * Makes a writable event from the given event. If the source event is
261 * already writable, this will simply return the same event. A copy will
262 * otherwise be made using gst_event_copy().
264 * Returns: (transfer full): a writable event which may or may not be the
267 #define gst_event_make_writable(ev) GST_EVENT_CAST (gst_mini_object_make_writable (GST_MINI_OBJECT_CAST (ev)))
270 * @old_event: (inout) (transfer full): pointer to a pointer to a #GstEvent
272 * @new_event: (allow-none) (transfer none): pointer to a #GstEvent that will
273 * replace the event pointed to by @old_event.
275 * Modifies a pointer to a #GstEvent to point to a different #GstEvent. The
276 * modification is done atomically (so this is useful for ensuring thread safety
277 * in some cases), and the reference counts are updated appropriately (the old
278 * event is unreffed, the new one is reffed).
280 * Either @new_event or the #GstEvent pointed to by @old_event may be NULL.
282 * Returns: TRUE if @new_event was different from @old_event
284 #ifdef _FOOL_GTK_DOC_
285 G_INLINE_FUNC gboolean gst_event_replace (GstEvent **old_event, GstEvent *new_event);
288 static inline gboolean
289 gst_event_replace (GstEvent **old_event, GstEvent *new_event)
291 return gst_mini_object_replace ((GstMiniObject **) old_event, (GstMiniObject *) new_event);
296 * @old_event: (inout) (transfer full): pointer to a pointer to a #GstEvent
299 * Atomically replace the #GstEvent pointed to by @old_event with NULL and
300 * return the original event.
302 * Returns: the #GstEvent that was in @old_event
304 #ifdef _FOOL_GTK_DOC_
305 G_INLINE_FUNC GstEvent * gst_event_steal (GstEvent **old_event);
308 static inline GstEvent *
309 gst_event_steal (GstEvent **old_event)
311 return GST_EVENT_CAST (gst_mini_object_steal ((GstMiniObject **) old_event));
316 * @old_event: (inout) (transfer full): pointer to a pointer to a #GstEvent
318 * @new_event: (allow-none) (transfer full): pointer to a #GstEvent that will
319 * replace the event pointed to by @old_event.
321 * Modifies a pointer to a #GstEvent to point to a different #GstEvent. This
322 * function is similar to gst_event_replace() except that it takes ownership of
325 * Either @new_event or the #GstEvent pointed to by @old_event may be NULL.
327 * Returns: TRUE if @new_event was different from @old_event
329 #ifdef _FOOL_GTK_DOC_
330 G_INLINE_FUNC gboolean gst_event_take (GstEvent **old_event, GstEvent *new_event);
333 static inline gboolean
334 gst_event_take (GstEvent **old_event, GstEvent *new_event)
336 return gst_mini_object_take ((GstMiniObject **) old_event, (GstMiniObject *) new_event);
341 * @GST_QOS_TYPE_OVERFLOW: The QoS event type that is produced when downstream
342 * elements are producing data too quickly and the element can't keep up
343 * processing the data. Upstream should reduce their processing rate. This
344 * type is also used when buffers arrive early or in time.
345 * @GST_QOS_TYPE_UNDERFLOW: The QoS event type that is produced when downstream
346 * elements are producing data too slowly and need to speed up their processing
348 * @GST_QOS_TYPE_THROTTLE: The QoS event type that is produced when the
349 * application enabled throttling to limit the datarate.
351 * The different types of QoS events that can be given to the
352 * gst_event_new_qos() method.
357 GST_QOS_TYPE_OVERFLOW = 0,
358 GST_QOS_TYPE_UNDERFLOW = 1,
359 GST_QOS_TYPE_THROTTLE = 2
364 * @mini_object: the parent structure
365 * @type: the #GstEventType of the event
366 * @timestamp: the timestamp of the event
367 * @seqnum: the sequence number of the event
372 GstMiniObject mini_object;
374 /*< public >*/ /* with COW */
380 const gchar* gst_event_type_get_name (GstEventType type);
381 GQuark gst_event_type_to_quark (GstEventType type);
383 gst_event_type_get_flags (GstEventType type);
389 * @event: The event to refcount
391 * Increase the refcount of this event.
393 * Returns: (transfer full): @event (for convenience when doing assignments)
395 #ifdef _FOOL_GTK_DOC_
396 G_INLINE_FUNC GstEvent * gst_event_ref (GstEvent * event);
399 static inline GstEvent *
400 gst_event_ref (GstEvent * event)
402 return (GstEvent *) gst_mini_object_ref (GST_MINI_OBJECT_CAST (event));
407 * @event: (transfer full): the event to refcount
409 * Decrease the refcount of an event, freeing it if the refcount reaches 0.
411 #ifdef _FOOL_GTK_DOC_
412 G_INLINE_FUNC void gst_event_unref (GstEvent * event);
416 gst_event_unref (GstEvent * event)
418 gst_mini_object_unref (GST_MINI_OBJECT_CAST (event));
424 * @event: The event to copy
426 * Copy the event using the event specific copy function.
428 * Returns: (transfer full): the new event
430 #ifdef _FOOL_GTK_DOC_
431 G_INLINE_FUNC GstEvent * gst_event_copy (const GstEvent * event);
434 static inline GstEvent *
435 gst_event_copy (const GstEvent * event)
437 return GST_EVENT_CAST (gst_mini_object_copy (GST_MINI_OBJECT_CONST_CAST (event)));
440 GType gst_event_get_type (void);
443 GstEvent* gst_event_new_custom (GstEventType type, GstStructure *structure) G_GNUC_MALLOC;
446 gst_event_get_structure (GstEvent *event);
447 GstStructure * gst_event_writable_structure (GstEvent *event);
449 gboolean gst_event_has_name (GstEvent *event, const gchar *name);
451 /* identifiers for events and messages */
452 guint32 gst_event_get_seqnum (GstEvent *event);
453 void gst_event_set_seqnum (GstEvent *event, guint32 seqnum);
456 GstEvent * gst_event_new_flush_start (void) G_GNUC_MALLOC;
458 GstEvent * gst_event_new_flush_stop (gboolean reset_time) G_GNUC_MALLOC;
459 void gst_event_parse_flush_stop (GstEvent *event, gboolean *reset_time);
462 GstEvent * gst_event_new_eos (void) G_GNUC_MALLOC;
465 GstEvent * gst_event_new_caps (GstCaps *caps) G_GNUC_MALLOC;
466 void gst_event_parse_caps (GstEvent *event, GstCaps **caps);
469 GstEvent* gst_event_new_segment (const GstSegment *segment) G_GNUC_MALLOC;
470 void gst_event_parse_segment (GstEvent *event, const GstSegment **segment);
471 void gst_event_copy_segment (GstEvent *event, GstSegment *segment);
474 GstEvent* gst_event_new_tag (GstTagList *taglist) G_GNUC_MALLOC;
475 void gst_event_parse_tag (GstEvent *event, GstTagList **taglist);
478 GstEvent * gst_event_new_buffer_size (GstFormat format, gint64 minsize, gint64 maxsize,
479 gboolean async) G_GNUC_MALLOC;
480 void gst_event_parse_buffer_size (GstEvent *event, GstFormat *format, gint64 *minsize,
481 gint64 *maxsize, gboolean *async);
484 GstEvent* gst_event_new_sink_message (GstMessage *msg) G_GNUC_MALLOC;
485 void gst_event_parse_sink_message (GstEvent *event, GstMessage **msg);
488 GstEvent* gst_event_new_qos (GstQOSType type, gdouble proportion,
489 GstClockTimeDiff diff, GstClockTime timestamp) G_GNUC_MALLOC;
490 void gst_event_parse_qos (GstEvent *event, GstQOSType *type,
491 gdouble *proportion, GstClockTimeDiff *diff,
492 GstClockTime *timestamp);
494 GstEvent* gst_event_new_seek (gdouble rate, GstFormat format, GstSeekFlags flags,
495 GstSeekType start_type, gint64 start,
496 GstSeekType stop_type, gint64 stop) G_GNUC_MALLOC;
497 void gst_event_parse_seek (GstEvent *event, gdouble *rate, GstFormat *format,
499 GstSeekType *start_type, gint64 *start,
500 GstSeekType *stop_type, gint64 *stop);
502 /* navigation event */
503 GstEvent* gst_event_new_navigation (GstStructure *structure) G_GNUC_MALLOC;
506 GstEvent* gst_event_new_latency (GstClockTime latency) G_GNUC_MALLOC;
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) G_GNUC_MALLOC;
512 void gst_event_parse_step (GstEvent *event, GstFormat *format, guint64 *amount,
513 gdouble *rate, gboolean *flush, gboolean *intermediate);
515 /* renegotiate event */
516 GstEvent* gst_event_new_reconfigure (void) G_GNUC_MALLOC;
520 #endif /* __GST_EVENT_H__ */