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
81 * @GST_EVENT_FLUSH_STOP: Stop a flush operation
82 * @GST_EVENT_EOS: End-Of-Stream. No more data is to be expected to follow
83 * without a NEWSEGMENT event.
84 * @GST_EVENT_NEWSEGMENT: A new media segment follows in the dataflow.
85 * @GST_EVENT_TAG: A new set of metadata tags has been found in the stream.
86 * @GST_EVENT_BUFFERSIZE: Notification of buffering requirements
87 * @GST_EVENT_QOS: A quality message. Used to indicate to upstream elements
88 * that the downstream elements are being starved of or
90 * @GST_EVENT_SEEK: A request for a new playback position and rate.
91 * @GST_EVENT_NAVIGATION: Navigation events are usually used for communicating
92 * user requests, such as mouse or keyboard movements,
93 * to upstream elements.
94 * @GST_EVENT_CUSTOM_UPSTREAM: Upstream custom event
95 * @GST_EVENT_CUSTOM_DOWNSTREAM: Downstream custom event that travels in the
97 * @GST_EVENT_CUSTOM_DOWNSTREAM_OOB: Custom out-of-band downstream event.
98 * @GST_EVENT_CUSTOM_BOTH: Custom upstream or downstream event.
99 * In-band when travelling downstream.
100 * @GST_EVENT_CUSTOM_BOTH_OOB: Custom upstream or downstream out-of-band event.
102 * #GstEventType lists the standard event types that can be sent in a pipeline.
104 * The custom event types can be used for private messages between elements
105 * that can't be expressed using normal
106 * GStreamer buffer passing semantics. Custom events carry an arbitrary
108 * Specific custom events are distinguished by the name of the structure.
110 /* NOTE: keep in sync with quark registration in gstevent.c */
112 GST_EVENT_UNKNOWN = GST_EVENT_MAKE_TYPE (0, 0),
113 /* bidirectional events */
114 GST_EVENT_FLUSH_START = GST_EVENT_MAKE_TYPE (1, FLAG(BOTH)),
115 GST_EVENT_FLUSH_STOP = GST_EVENT_MAKE_TYPE (2, FLAG(BOTH) | FLAG(SERIALIZED)),
116 /* downstream serialized events */
117 GST_EVENT_EOS = GST_EVENT_MAKE_TYPE (5, FLAG(DOWNSTREAM) | FLAG(SERIALIZED)),
118 GST_EVENT_NEWSEGMENT = GST_EVENT_MAKE_TYPE (6, FLAG(DOWNSTREAM) | FLAG(SERIALIZED)),
119 GST_EVENT_TAG = GST_EVENT_MAKE_TYPE (7, FLAG(DOWNSTREAM) | FLAG(SERIALIZED)),
120 GST_EVENT_BUFFERSIZE = GST_EVENT_MAKE_TYPE (8, FLAG(DOWNSTREAM) | FLAG(SERIALIZED)),
121 /* upstream events */
122 GST_EVENT_QOS = GST_EVENT_MAKE_TYPE (15, FLAG(UPSTREAM)),
123 GST_EVENT_SEEK = GST_EVENT_MAKE_TYPE (16, FLAG(UPSTREAM)),
124 GST_EVENT_NAVIGATION = GST_EVENT_MAKE_TYPE (17, FLAG(UPSTREAM)),
126 /* custom events start here */
127 GST_EVENT_CUSTOM_UPSTREAM = GST_EVENT_MAKE_TYPE (32, FLAG(UPSTREAM)),
128 GST_EVENT_CUSTOM_DOWNSTREAM = GST_EVENT_MAKE_TYPE (32, FLAG(DOWNSTREAM) | FLAG(SERIALIZED)),
129 GST_EVENT_CUSTOM_DOWNSTREAM_OOB = GST_EVENT_MAKE_TYPE (32, FLAG(DOWNSTREAM)),
130 GST_EVENT_CUSTOM_BOTH = GST_EVENT_MAKE_TYPE (32, FLAG(BOTH) | FLAG(SERIALIZED)),
131 GST_EVENT_CUSTOM_BOTH_OOB = GST_EVENT_MAKE_TYPE (32, FLAG(BOTH))
136 * GST_EVENT_TRACE_NAME:
138 * The name used for memory allocation tracing
140 #define GST_EVENT_TRACE_NAME "GstEvent"
142 typedef struct _GstEvent GstEvent;
143 typedef struct _GstEventClass GstEventClass;
145 #define GST_TYPE_EVENT (gst_event_get_type())
146 #define GST_IS_EVENT(obj) (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GST_TYPE_EVENT))
147 #define GST_IS_EVENT_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GST_TYPE_EVENT))
148 #define GST_EVENT_GET_CLASS(obj) (G_TYPE_INSTANCE_GET_CLASS ((obj), GST_TYPE_EVENT, GstEventClass))
149 #define GST_EVENT(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), GST_TYPE_EVENT, GstEvent))
150 #define GST_EVENT_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST ((klass), GST_TYPE_EVENT, GstEventClass))
151 #define GST_EVENT_CAST(obj) ((GstEvent *)(obj))
155 * @event: the event to query
157 * Get the #GstEventType of the event.
159 #define GST_EVENT_TYPE(event) (GST_EVENT_CAST(event)->type)
162 * GST_EVENT_TYPE_NAME:
163 * @event: the event to query
165 * Get a constant string representation of the #GstEventType of the event.
167 #define GST_EVENT_TYPE_NAME(event) (gst_event_type_get_name(GST_EVENT_TYPE(event)))
170 * GST_EVENT_TIMESTAMP:
171 * @event: the event to query
173 * Get the #GstClockTime timestamp of the event. This is the time when the event
176 #define GST_EVENT_TIMESTAMP(event) (GST_EVENT_CAST(event)->timestamp)
180 * @event: the event to query
182 * The source #GstObject that generated this event.
184 #define GST_EVENT_SRC(event) (GST_EVENT_CAST(event)->src)
187 * GST_EVENT_IS_UPSTREAM:
188 * @ev: the event to query
190 * Check if an event can travel upstream.
192 #define GST_EVENT_IS_UPSTREAM(ev) !!(GST_EVENT_TYPE (ev) & GST_EVENT_TYPE_UPSTREAM)
194 * GST_EVENT_IS_DOWNSTREAM:
195 * @ev: the event to query
197 * Check if an event can travel downstream.
199 #define GST_EVENT_IS_DOWNSTREAM(ev) !!(GST_EVENT_TYPE (ev) & GST_EVENT_TYPE_DOWNSTREAM)
201 * GST_EVENT_IS_SERIALIZED:
202 * @ev: the event to query
204 * Check if an event is serialized with the data stream.
206 #define GST_EVENT_IS_SERIALIZED(ev) !!(GST_EVENT_TYPE (ev) & GST_EVENT_TYPE_SERIALIZED)
210 * @old_event: pointer to a pointer to a #GstEvent to be replaced.
211 * @new_event: pointer to a #GstEvent that will replace the event pointed to
214 * Modifies a pointer to a #GstEvent to point to a different #GstEvent. The
215 * modification is done atomically (so this is useful for ensuring thread safety
216 * in some cases), and the reference counts are updated appropriately (the old
217 * event is unreffed, the new one is reffed).
219 * Either @new_event or the #GstEvent pointed to by @old_event may be NULL.
223 #define gst_event_replace(old_event,new_event) \
224 gst_mini_object_replace ((GstMiniObject **)(old_event), GST_MINI_OBJECT (new_event))
228 * @GST_SEEK_TYPE_NONE: no change in position is required
229 * @GST_SEEK_TYPE_CUR: change relative to current position
230 * @GST_SEEK_TYPE_SET: absolute position is requested
231 * @GST_SEEK_TYPE_END: relative position to duration is requested
233 * The different types of seek events. When constructing a seek event, a format,
234 * a seek method and optional flags are to be provided. The seek event is then
235 * inserted into the graph with gst_pad_send_event() or
236 * gst_element_send_event().
240 GST_SEEK_TYPE_NONE = 0,
241 GST_SEEK_TYPE_CUR = 1,
242 GST_SEEK_TYPE_SET = 2,
243 GST_SEEK_TYPE_END = 3
248 * @GST_SEEK_FLAG_NONE: no flag
249 * @GST_SEEK_FLAG_FLUSH: flush pipeline
250 * @GST_SEEK_FLAG_ACCURATE: accurate position is requested, this might
251 * be considerably slower for some formats.
252 * @GST_SEEK_FLAG_KEY_UNIT: seek to the nearest keyframe. This might be
253 * faster but less accurate.
254 * @GST_SEEK_FLAG_SEGMENT: perform a segment seek.
256 * Flags to be used with gst_element_seek() or gst_event_new_seek()
258 * A non flushing seek might take some time to perform as the currently
259 * playing data in the pipeline will not be cleared.
261 * An accurate seek might be slower for formats that don't have any indexes
262 * or timestamp markers in the stream. Specifying this flag might require a
263 * complete scan of the file in those cases.
265 * When performing a segment seek: after the playback of the segment completes,
266 * no EOS will be emmited by the element that performed the seek, but a
267 * SEGMENT_DONE message will be posted on the bus by the element. When this
268 * message is posted, it is possible to send a new seek event to continue
269 * playback. With this seek method it is possible to perform seemless looping
270 * or simple linear editing.
273 GST_SEEK_FLAG_NONE = 0,
274 GST_SEEK_FLAG_FLUSH = (1 << 0),
275 GST_SEEK_FLAG_ACCURATE = (1 << 1),
276 GST_SEEK_FLAG_KEY_UNIT = (1 << 2),
277 GST_SEEK_FLAG_SEGMENT = (1 << 3)
283 * @mini_object: the parent structure
284 * @type: the #GstEventType of the event
285 * @timestamp: the timestamp of the event
286 * @src: the src of the event
287 * @structure: the #GstStructure containing the event info.
292 GstMiniObject mini_object;
294 /*< public >*/ /* with COW */
299 GstStructure *structure;
302 gpointer _gst_reserved;
305 struct _GstEventClass {
306 GstMiniObjectClass mini_object_class;
309 gpointer _gst_reserved[GST_PADDING];
312 void _gst_event_initialize (void);
314 const gchar* gst_event_type_get_name (GstEventType type);
315 GQuark gst_event_type_to_quark (GstEventType type);
317 gst_event_type_get_flags (GstEventType type);
320 GType gst_event_get_type (void);
325 * @event: The event to refcount
327 * Increase the refcount of this event.
329 * Returns: @event (for convenience when doing assignments)
331 #ifdef _FOOL_GTK_DOC_
332 G_INLINE_FUNC GstEvent * gst_event_ref (GstEvent * event);
335 static inline GstEvent *
336 gst_event_ref (GstEvent * ev)
338 /* not using a macro here because gcc-4.1 will complain
339 * if the return value isn't used (because of the cast) */
340 return (GstEvent *) gst_mini_object_ref (GST_MINI_OBJECT (ev));
345 * @ev: The event to refcount
347 * Decrease the refcount of an event, freeing it if the refcount reaches 0.
349 #define gst_event_unref(ev) gst_mini_object_unref (GST_MINI_OBJECT (ev))
354 * @ev: The event to copy
356 * Copy the event using the event specific copy function.
358 #define gst_event_copy(ev) GST_EVENT_CAST (gst_mini_object_copy (GST_MINI_OBJECT (ev)))
361 GstEvent* gst_event_new_custom (GstEventType type, GstStructure *structure);
364 gst_event_get_structure (GstEvent *event);
367 GstEvent * gst_event_new_flush_start (void);
368 GstEvent * gst_event_new_flush_stop (void);
371 GstEvent * gst_event_new_eos (void);
373 /* newsegment events */
374 GstEvent* gst_event_new_new_segment (gboolean update, gdouble rate,
376 gint64 start, gint64 stop,
378 GstEvent* gst_event_new_new_segment_full (gboolean update, gdouble rate,
379 gdouble applied_rate,
381 gint64 start, gint64 stop,
383 void gst_event_parse_new_segment (GstEvent *event,
387 gint64 *start, gint64 *stop,
389 void gst_event_parse_new_segment_full (GstEvent *event,
392 gdouble *applied_rate,
394 gint64 *start, gint64 *stop,
398 GstEvent* gst_event_new_tag (GstTagList *taglist);
399 void gst_event_parse_tag (GstEvent *event, GstTagList **taglist);
402 GstEvent * gst_event_new_buffer_size (GstFormat format, gint64 minsize, gint64 maxsize,
404 void gst_event_parse_buffer_size (GstEvent *event, GstFormat *format, gint64 *minsize,
405 gint64 *maxsize, gboolean *async);
408 GstEvent* gst_event_new_qos (gdouble proportion, GstClockTimeDiff diff,
409 GstClockTime timestamp);
410 void gst_event_parse_qos (GstEvent *event, gdouble *proportion, GstClockTimeDiff *diff,
411 GstClockTime *timestamp);
413 GstEvent* gst_event_new_seek (gdouble rate, GstFormat format, GstSeekFlags flags,
414 GstSeekType cur_type, gint64 cur,
415 GstSeekType stop_type, gint64 stop);
416 void gst_event_parse_seek (GstEvent *event, gdouble *rate, GstFormat *format,
418 GstSeekType *cur_type, gint64 *cur,
419 GstSeekType *stop_type, gint64 *stop);
420 /* navigation event */
421 GstEvent* gst_event_new_navigation (GstStructure *structure);
425 #endif /* __GST_EVENT_H__ */