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_SINK_MESSAGE: An event that sinks turn into a message. Used to
88 * send messages that should be emitted in sync with
90 * @GST_EVENT_QOS: A quality message. Used to indicate to upstream elements
91 * that the downstream elements are being starved of or
93 * @GST_EVENT_SEEK: A request for a new playback position and rate.
94 * @GST_EVENT_NAVIGATION: Navigation events are usually used for communicating
95 * user requests, such as mouse or keyboard movements,
96 * to upstream elements.
97 * @GST_EVENT_LATENCY: Notification of new latency adjustment. Since: 0.10.12
98 * @GST_EVENT_STEP: A request for stepping through the media. Since: 0.10.24
99 * @GST_EVENT_CUSTOM_UPSTREAM: Upstream custom event
100 * @GST_EVENT_CUSTOM_DOWNSTREAM: Downstream custom event that travels in the
102 * @GST_EVENT_CUSTOM_DOWNSTREAM_OOB: Custom out-of-band downstream event.
103 * @GST_EVENT_CUSTOM_BOTH: Custom upstream or downstream event.
104 * In-band when travelling downstream.
105 * @GST_EVENT_CUSTOM_BOTH_OOB: Custom upstream or downstream out-of-band event.
107 * #GstEventType lists the standard event types that can be sent in a pipeline.
109 * The custom event types can be used for private messages between elements
110 * that can't be expressed using normal
111 * GStreamer buffer passing semantics. Custom events carry an arbitrary
113 * Specific custom events are distinguished by the name of the structure.
115 /* NOTE: keep in sync with quark registration in gstevent.c */
117 GST_EVENT_UNKNOWN = GST_EVENT_MAKE_TYPE (0, 0),
118 /* bidirectional events */
119 GST_EVENT_FLUSH_START = GST_EVENT_MAKE_TYPE (1, FLAG(BOTH)),
120 GST_EVENT_FLUSH_STOP = GST_EVENT_MAKE_TYPE (2, FLAG(BOTH) | FLAG(SERIALIZED)),
121 /* downstream serialized events */
122 GST_EVENT_EOS = GST_EVENT_MAKE_TYPE (5, FLAG(DOWNSTREAM) | FLAG(SERIALIZED)),
123 GST_EVENT_NEWSEGMENT = GST_EVENT_MAKE_TYPE (6, FLAG(DOWNSTREAM) | FLAG(SERIALIZED)),
124 GST_EVENT_TAG = GST_EVENT_MAKE_TYPE (7, FLAG(DOWNSTREAM) | FLAG(SERIALIZED)),
125 GST_EVENT_BUFFERSIZE = GST_EVENT_MAKE_TYPE (8, FLAG(DOWNSTREAM) | FLAG(SERIALIZED)),
126 GST_EVENT_SINK_MESSAGE = GST_EVENT_MAKE_TYPE (9, FLAG(DOWNSTREAM) | FLAG(SERIALIZED)),
127 /* upstream events */
128 GST_EVENT_QOS = GST_EVENT_MAKE_TYPE (15, FLAG(UPSTREAM)),
129 GST_EVENT_SEEK = GST_EVENT_MAKE_TYPE (16, FLAG(UPSTREAM)),
130 GST_EVENT_NAVIGATION = GST_EVENT_MAKE_TYPE (17, FLAG(UPSTREAM)),
131 GST_EVENT_LATENCY = GST_EVENT_MAKE_TYPE (18, FLAG(UPSTREAM)),
132 GST_EVENT_STEP = GST_EVENT_MAKE_TYPE (19, FLAG(UPSTREAM)),
134 /* custom events start here */
135 GST_EVENT_CUSTOM_UPSTREAM = GST_EVENT_MAKE_TYPE (32, FLAG(UPSTREAM)),
136 GST_EVENT_CUSTOM_DOWNSTREAM = GST_EVENT_MAKE_TYPE (32, FLAG(DOWNSTREAM) | FLAG(SERIALIZED)),
137 GST_EVENT_CUSTOM_DOWNSTREAM_OOB = GST_EVENT_MAKE_TYPE (32, FLAG(DOWNSTREAM)),
138 GST_EVENT_CUSTOM_BOTH = GST_EVENT_MAKE_TYPE (32, FLAG(BOTH) | FLAG(SERIALIZED)),
139 GST_EVENT_CUSTOM_BOTH_OOB = GST_EVENT_MAKE_TYPE (32, FLAG(BOTH))
144 * GST_EVENT_TRACE_NAME:
146 * The name used for memory allocation tracing
148 #define GST_EVENT_TRACE_NAME "GstEvent"
150 typedef struct _GstEvent GstEvent;
151 typedef struct _GstEventClass GstEventClass;
153 #define GST_TYPE_EVENT (gst_event_get_type())
154 #define GST_IS_EVENT(obj) (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GST_TYPE_EVENT))
155 #define GST_IS_EVENT_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GST_TYPE_EVENT))
156 #define GST_EVENT_GET_CLASS(obj) (G_TYPE_INSTANCE_GET_CLASS ((obj), GST_TYPE_EVENT, GstEventClass))
157 #define GST_EVENT(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), GST_TYPE_EVENT, GstEvent))
158 #define GST_EVENT_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST ((klass), GST_TYPE_EVENT, GstEventClass))
159 #define GST_EVENT_CAST(obj) ((GstEvent *)(obj))
163 * @event: the event to query
165 * Get the #GstEventType of the event.
167 #define GST_EVENT_TYPE(event) (GST_EVENT_CAST(event)->type)
170 * GST_EVENT_TYPE_NAME:
171 * @event: the event to query
173 * Get a constant string representation of the #GstEventType of the event.
175 #define GST_EVENT_TYPE_NAME(event) (gst_event_type_get_name(GST_EVENT_TYPE(event)))
178 * GST_EVENT_TIMESTAMP:
179 * @event: the event to query
181 * Get the #GstClockTime timestamp of the event. This is the time when the event
184 #define GST_EVENT_TIMESTAMP(event) (GST_EVENT_CAST(event)->timestamp)
188 * @event: the event to query
190 * The source #GstObject that generated this event.
192 #define GST_EVENT_SRC(event) (GST_EVENT_CAST(event)->src)
195 * GST_EVENT_IS_UPSTREAM:
196 * @ev: the event to query
198 * Check if an event can travel upstream.
200 #define GST_EVENT_IS_UPSTREAM(ev) !!(GST_EVENT_TYPE (ev) & GST_EVENT_TYPE_UPSTREAM)
202 * GST_EVENT_IS_DOWNSTREAM:
203 * @ev: the event to query
205 * Check if an event can travel downstream.
207 #define GST_EVENT_IS_DOWNSTREAM(ev) !!(GST_EVENT_TYPE (ev) & GST_EVENT_TYPE_DOWNSTREAM)
209 * GST_EVENT_IS_SERIALIZED:
210 * @ev: the event to query
212 * Check if an event is serialized with the data stream.
214 #define GST_EVENT_IS_SERIALIZED(ev) !!(GST_EVENT_TYPE (ev) & GST_EVENT_TYPE_SERIALIZED)
218 * @old_event: pointer to a pointer to a #GstEvent to be replaced.
219 * @new_event: pointer to a #GstEvent that will replace the event pointed to
222 * Modifies a pointer to a #GstEvent to point to a different #GstEvent. The
223 * modification is done atomically (so this is useful for ensuring thread safety
224 * in some cases), and the reference counts are updated appropriately (the old
225 * event is unreffed, the new one is reffed).
227 * Either @new_event or the #GstEvent pointed to by @old_event may be NULL.
231 #define gst_event_replace(old_event,new_event) \
232 gst_mini_object_replace ((GstMiniObject **)(old_event), GST_MINI_OBJECT_CAST (new_event))
236 * @GST_SEEK_TYPE_NONE: no change in position is required
237 * @GST_SEEK_TYPE_CUR: change relative to currently configured segment. This
238 * can't be used to seek relative to the current playback position - do a
239 * position query, calculate the desired position and then do an absolute
240 * position seek instead if that's what you want to do.
241 * @GST_SEEK_TYPE_SET: absolute position is requested
242 * @GST_SEEK_TYPE_END: relative position to duration is requested
244 * The different types of seek events. When constructing a seek event with
245 * gst_event_new_seek(), a format, a seek method and optional flags are to
246 * be provided. The seek event is then inserted into the graph with
247 * gst_pad_send_event() or gst_element_send_event().
251 GST_SEEK_TYPE_NONE = 0,
252 GST_SEEK_TYPE_CUR = 1,
253 GST_SEEK_TYPE_SET = 2,
254 GST_SEEK_TYPE_END = 3
259 * @GST_SEEK_FLAG_NONE: no flag
260 * @GST_SEEK_FLAG_FLUSH: flush pipeline
261 * @GST_SEEK_FLAG_ACCURATE: accurate position is requested, this might
262 * be considerably slower for some formats.
263 * @GST_SEEK_FLAG_KEY_UNIT: seek to the nearest keyframe. This might be
264 * faster but less accurate.
265 * @GST_SEEK_FLAG_SEGMENT: perform a segment seek.
266 * @GST_SEEK_FLAG_SKIP: when doing fast foward or fast reverse playback, allow
267 * elements to skip frames instead of generating all
268 * frames. Since 0.10.22.
270 * Flags to be used with gst_element_seek() or gst_event_new_seek(). All flags
271 * can be used together.
273 * A non flushing seek might take some time to perform as the currently
274 * playing data in the pipeline will not be cleared.
276 * An accurate seek might be slower for formats that don't have any indexes
277 * or timestamp markers in the stream. Specifying this flag might require a
278 * complete scan of the file in those cases.
280 * When performing a segment seek: after the playback of the segment completes,
281 * no EOS will be emmited by the element that performed the seek, but a
282 * #GST_MESSAGE_SEGMENT_DONE message will be posted on the bus by the element.
283 * When this message is posted, it is possible to send a new seek event to
284 * continue playback. With this seek method it is possible to perform seemless
285 * looping or simple linear editing.
287 * When doing fast forward (rate > 1.0) or fast reverse (rate < -1.0) trickmode
288 * playback, the @GST_SEEK_FLAG_SKIP flag can be used to instruct decoders
289 * and demuxers to adjust the playback rate by skipping frames. This can improve
290 * performance and decrease CPU usage because not all frames need to be decoded.
293 GST_SEEK_FLAG_NONE = 0,
294 GST_SEEK_FLAG_FLUSH = (1 << 0),
295 GST_SEEK_FLAG_ACCURATE = (1 << 1),
296 GST_SEEK_FLAG_KEY_UNIT = (1 << 2),
297 GST_SEEK_FLAG_SEGMENT = (1 << 3),
298 GST_SEEK_FLAG_SKIP = (1 << 4)
303 * @mini_object: the parent structure
304 * @type: the #GstEventType of the event
305 * @timestamp: the timestamp of the event
306 * @src: the src of the event
307 * @structure: the #GstStructure containing the event info.
312 GstMiniObject mini_object;
314 /*< public >*/ /* with COW */
319 GstStructure *structure;
324 gpointer _gst_reserved;
328 struct _GstEventClass {
329 GstMiniObjectClass mini_object_class;
332 gpointer _gst_reserved[GST_PADDING];
335 const gchar* gst_event_type_get_name (GstEventType type);
336 GQuark gst_event_type_to_quark (GstEventType type);
338 gst_event_type_get_flags (GstEventType type);
341 GType gst_event_get_type (void);
346 * @event: The event to refcount
348 * Increase the refcount of this event.
350 * Returns: @event (for convenience when doing assignments)
352 #ifdef _FOOL_GTK_DOC_
353 G_INLINE_FUNC GstEvent * gst_event_ref (GstEvent * event);
356 static inline GstEvent *
357 gst_event_ref (GstEvent * event)
359 return (GstEvent *) gst_mini_object_ref (GST_MINI_OBJECT_CAST (event));
364 * @event: The event to refcount
366 * Decrease the refcount of an event, freeing it if the refcount reaches 0.
368 #ifdef _FOOL_GTK_DOC_
369 G_INLINE_FUNC void gst_event_unref (GstEvent * event);
373 gst_event_unref (GstEvent * event)
375 gst_mini_object_unref (GST_MINI_OBJECT_CAST (event));
381 * @event: The event to copy
383 * Copy the event using the event specific copy function.
385 * Returns: the new event
387 #ifdef _FOOL_GTK_DOC_
388 G_INLINE_FUNC GstEvent * gst_event_copy (const GstEvent * event);
391 static inline GstEvent *
392 gst_event_copy (const GstEvent * event)
394 return GST_EVENT_CAST (gst_mini_object_copy (GST_MINI_OBJECT_CAST (event)));
399 GstEvent* gst_event_new_custom (GstEventType type, GstStructure *structure);
402 gst_event_get_structure (GstEvent *event);
404 gboolean gst_event_has_name (GstEvent *event, const gchar *name);
406 /* identifiers for events and messages */
407 guint32 gst_event_get_seqnum (GstEvent *event);
408 void gst_event_set_seqnum (GstEvent *event, guint32 seqnum);
411 GstEvent * gst_event_new_flush_start (void);
412 GstEvent * gst_event_new_flush_stop (void);
415 GstEvent * gst_event_new_eos (void);
417 /* newsegment events */
418 GstEvent* gst_event_new_new_segment (gboolean update, gdouble rate,
420 gint64 start, gint64 stop,
422 GstEvent* gst_event_new_new_segment_full (gboolean update, gdouble rate,
423 gdouble applied_rate,
425 gint64 start, gint64 stop,
427 void gst_event_parse_new_segment (GstEvent *event,
431 gint64 *start, gint64 *stop,
433 void gst_event_parse_new_segment_full (GstEvent *event,
436 gdouble *applied_rate,
438 gint64 *start, gint64 *stop,
442 GstEvent* gst_event_new_tag (GstTagList *taglist);
443 void gst_event_parse_tag (GstEvent *event, GstTagList **taglist);
446 GstEvent * gst_event_new_buffer_size (GstFormat format, gint64 minsize, gint64 maxsize,
448 void gst_event_parse_buffer_size (GstEvent *event, GstFormat *format, gint64 *minsize,
449 gint64 *maxsize, gboolean *async);
452 GstEvent* gst_event_new_qos (gdouble proportion, GstClockTimeDiff diff,
453 GstClockTime timestamp);
454 void gst_event_parse_qos (GstEvent *event, gdouble *proportion, GstClockTimeDiff *diff,
455 GstClockTime *timestamp);
457 GstEvent* gst_event_new_seek (gdouble rate, GstFormat format, GstSeekFlags flags,
458 GstSeekType start_type, gint64 start,
459 GstSeekType stop_type, gint64 stop);
460 void gst_event_parse_seek (GstEvent *event, gdouble *rate, GstFormat *format,
462 GstSeekType *start_type, gint64 *start,
463 GstSeekType *stop_type, gint64 *stop);
464 /* navigation event */
465 GstEvent* gst_event_new_navigation (GstStructure *structure);
468 GstEvent* gst_event_new_latency (GstClockTime latency);
469 void gst_event_parse_latency (GstEvent *event, GstClockTime *latency);
472 GstEvent* gst_event_new_step (GstFormat format, guint64 amount, gdouble rate,
473 gboolean flush, gboolean intermediate);
474 void gst_event_parse_step (GstEvent *event, GstFormat *format, guint64 *amount,
475 gdouble *rate, gboolean *flush, gboolean *intermediate);
479 #endif /* __GST_EVENT_H__ */