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;
161 typedef struct _GstEventClass GstEventClass;
163 #define GST_TYPE_EVENT (gst_event_get_type())
164 #define GST_IS_EVENT(obj) (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GST_TYPE_EVENT))
165 #define GST_IS_EVENT_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GST_TYPE_EVENT))
166 #define GST_EVENT_GET_CLASS(obj) (G_TYPE_INSTANCE_GET_CLASS ((obj), GST_TYPE_EVENT, GstEventClass))
167 #define GST_EVENT(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), GST_TYPE_EVENT, GstEvent))
168 #define GST_EVENT_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST ((klass), GST_TYPE_EVENT, GstEventClass))
169 #define GST_EVENT_CAST(obj) ((GstEvent *)(obj))
173 * @event: the event to query
175 * Get the #GstEventType of the event.
177 #define GST_EVENT_TYPE(event) (GST_EVENT_CAST(event)->type)
180 * GST_EVENT_TYPE_NAME:
181 * @event: the event to query
183 * Get a constant string representation of the #GstEventType of the event.
185 #define GST_EVENT_TYPE_NAME(event) (gst_event_type_get_name(GST_EVENT_TYPE(event)))
188 * GST_EVENT_TIMESTAMP:
189 * @event: the event to query
191 * Get the #GstClockTime timestamp of the event. This is the time when the event
194 #define GST_EVENT_TIMESTAMP(event) (GST_EVENT_CAST(event)->timestamp)
198 * @event: the event to query
200 * The source #GstObject that generated this event.
202 #define GST_EVENT_SRC(event) (GST_EVENT_CAST(event)->src)
205 * GST_EVENT_IS_UPSTREAM:
206 * @ev: the event to query
208 * Check if an event can travel upstream.
210 #define GST_EVENT_IS_UPSTREAM(ev) !!(GST_EVENT_TYPE (ev) & GST_EVENT_TYPE_UPSTREAM)
212 * GST_EVENT_IS_DOWNSTREAM:
213 * @ev: the event to query
215 * Check if an event can travel downstream.
217 #define GST_EVENT_IS_DOWNSTREAM(ev) !!(GST_EVENT_TYPE (ev) & GST_EVENT_TYPE_DOWNSTREAM)
219 * GST_EVENT_IS_SERIALIZED:
220 * @ev: the event to query
222 * Check if an event is serialized with the data stream.
224 #define GST_EVENT_IS_SERIALIZED(ev) !!(GST_EVENT_TYPE (ev) & GST_EVENT_TYPE_SERIALIZED)
228 * @old_event: (inout) (transfer full): pointer to a pointer to a #GstEvent
230 * @new_event: (allow-none) (transfer none): pointer to a #GstEvent that will
231 * replace the event pointed to by @old_event.
233 * Modifies a pointer to a #GstEvent to point to a different #GstEvent. The
234 * modification is done atomically (so this is useful for ensuring thread safety
235 * in some cases), and the reference counts are updated appropriately (the old
236 * event is unreffed, the new one is reffed).
238 * Either @new_event or the #GstEvent pointed to by @old_event may be NULL.
242 #ifdef _FOOL_GTK_DOC_
243 G_INLINE_FUNC void gst_event_replace (GstEvent **old_event, GstEvent *new_event);
247 gst_event_replace (GstEvent **old_event, GstEvent *new_event)
249 gst_mini_object_replace ((GstMiniObject **) old_event, (GstMiniObject *) new_event);
254 * @GST_SEEK_TYPE_NONE: no change in position is required
255 * @GST_SEEK_TYPE_CUR: change relative to currently configured segment. This
256 * can't be used to seek relative to the current playback position - do a
257 * position query, calculate the desired position and then do an absolute
258 * position seek instead if that's what you want to do.
259 * @GST_SEEK_TYPE_SET: absolute position is requested
260 * @GST_SEEK_TYPE_END: relative position to duration is requested
262 * The different types of seek events. When constructing a seek event with
263 * gst_event_new_seek(), a format, a seek method and optional flags are to
264 * be provided. The seek event is then inserted into the graph with
265 * gst_pad_send_event() or gst_element_send_event().
269 GST_SEEK_TYPE_NONE = 0,
270 GST_SEEK_TYPE_CUR = 1,
271 GST_SEEK_TYPE_SET = 2,
272 GST_SEEK_TYPE_END = 3
277 * @GST_SEEK_FLAG_NONE: no flag
278 * @GST_SEEK_FLAG_FLUSH: flush pipeline
279 * @GST_SEEK_FLAG_ACCURATE: accurate position is requested, this might
280 * be considerably slower for some formats.
281 * @GST_SEEK_FLAG_KEY_UNIT: seek to the nearest keyframe. This might be
282 * faster but less accurate.
283 * @GST_SEEK_FLAG_SEGMENT: perform a segment seek.
284 * @GST_SEEK_FLAG_SKIP: when doing fast foward or fast reverse playback, allow
285 * elements to skip frames instead of generating all
286 * frames. Since 0.10.22.
288 * Flags to be used with gst_element_seek() or gst_event_new_seek(). All flags
289 * can be used together.
291 * A non flushing seek might take some time to perform as the currently
292 * playing data in the pipeline will not be cleared.
294 * An accurate seek might be slower for formats that don't have any indexes
295 * or timestamp markers in the stream. Specifying this flag might require a
296 * complete scan of the file in those cases.
298 * When performing a segment seek: after the playback of the segment completes,
299 * no EOS will be emmited by the element that performed the seek, but a
300 * #GST_MESSAGE_SEGMENT_DONE message will be posted on the bus by the element.
301 * When this message is posted, it is possible to send a new seek event to
302 * continue playback. With this seek method it is possible to perform seamless
303 * looping or simple linear editing.
305 * When doing fast forward (rate > 1.0) or fast reverse (rate < -1.0) trickmode
306 * playback, the @GST_SEEK_FLAG_SKIP flag can be used to instruct decoders
307 * and demuxers to adjust the playback rate by skipping frames. This can improve
308 * performance and decrease CPU usage because not all frames need to be decoded.
310 * Also see part-seeking.txt in the GStreamer design documentation for more
311 * details on the meaning of these flags and the behaviour expected of
312 * elements that handle them.
315 GST_SEEK_FLAG_NONE = 0,
316 GST_SEEK_FLAG_FLUSH = (1 << 0),
317 GST_SEEK_FLAG_ACCURATE = (1 << 1),
318 GST_SEEK_FLAG_KEY_UNIT = (1 << 2),
319 GST_SEEK_FLAG_SEGMENT = (1 << 3),
320 GST_SEEK_FLAG_SKIP = (1 << 4)
325 * @GST_QOS_TYPE_OVERFLOW: The QoS event type that is produced when downstream
326 * elements are producing data too quickly and the element can't keep up
327 * processing the data. Upstream should reduce their processing rate. This
328 * type is also used when buffers arrive early or in time.
329 * @GST_QOS_TYPE_UNDERFLOW: The QoS event type that is produced when downstream
330 * elements are producing data too slowly and need to speed up their processing
332 * @GST_QOS_TYPE_THROTTLE: The QoS event type that is produced when the
333 * application enabled throttling to limit the datarate.
335 * The different types of QoS events that can be given to the
336 * gst_event_new_qos_full() method.
341 GST_QOS_TYPE_OVERFLOW = 0,
342 GST_QOS_TYPE_UNDERFLOW = 1,
343 GST_QOS_TYPE_THROTTLE = 2
348 * @mini_object: the parent structure
349 * @type: the #GstEventType of the event
350 * @timestamp: the timestamp of the event
351 * @src: the src of the event
352 * @structure: the #GstStructure containing the event info.
357 GstMiniObject mini_object;
359 /*< public >*/ /* with COW */
364 GstStructure *structure;
369 gpointer _gst_reserved;
373 struct _GstEventClass {
374 GstMiniObjectClass mini_object_class;
377 gpointer _gst_reserved[GST_PADDING];
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);
386 GType gst_event_get_type (void);
391 * @event: The event to refcount
393 * Increase the refcount of this event.
395 * Returns: (transfer full): @event (for convenience when doing assignments)
397 #ifdef _FOOL_GTK_DOC_
398 G_INLINE_FUNC GstEvent * gst_event_ref (GstEvent * event);
401 static inline GstEvent *
402 gst_event_ref (GstEvent * event)
404 return (GstEvent *) gst_mini_object_ref (GST_MINI_OBJECT_CAST (event));
409 * @event: (transfer full): the event to refcount
411 * Decrease the refcount of an event, freeing it if the refcount reaches 0.
413 #ifdef _FOOL_GTK_DOC_
414 G_INLINE_FUNC void gst_event_unref (GstEvent * event);
418 gst_event_unref (GstEvent * event)
420 gst_mini_object_unref (GST_MINI_OBJECT_CAST (event));
426 * @event: The event to copy
428 * Copy the event using the event specific copy function.
430 * Returns: (transfer full): the new event
432 #ifdef _FOOL_GTK_DOC_
433 G_INLINE_FUNC GstEvent * gst_event_copy (const GstEvent * event);
436 static inline GstEvent *
437 gst_event_copy (const GstEvent * event)
439 return GST_EVENT_CAST (gst_mini_object_copy (GST_MINI_OBJECT_CONST_CAST (event)));
444 GstEvent* gst_event_new_custom (GstEventType type, GstStructure *structure) G_GNUC_MALLOC;
447 gst_event_get_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;
457 GstEvent * gst_event_new_flush_stop (void) G_GNUC_MALLOC;
460 GstEvent * gst_event_new_eos (void) G_GNUC_MALLOC;
462 /* newsegment events */
463 GstEvent* gst_event_new_new_segment (gboolean update, gdouble rate,
465 gint64 start, gint64 stop,
466 gint64 position) G_GNUC_MALLOC;
467 GstEvent* gst_event_new_new_segment_full (gboolean update, gdouble rate,
468 gdouble applied_rate,
470 gint64 start, gint64 stop,
471 gint64 position) G_GNUC_MALLOC;
472 void gst_event_parse_new_segment (GstEvent *event,
476 gint64 *start, gint64 *stop,
478 void gst_event_parse_new_segment_full (GstEvent *event,
481 gdouble *applied_rate,
483 gint64 *start, gint64 *stop,
487 GstEvent* gst_event_new_tag (GstTagList *taglist) G_GNUC_MALLOC;
488 void gst_event_parse_tag (GstEvent *event, GstTagList **taglist);
491 GstEvent * gst_event_new_buffer_size (GstFormat format, gint64 minsize, gint64 maxsize,
492 gboolean async) G_GNUC_MALLOC;
493 void gst_event_parse_buffer_size (GstEvent *event, GstFormat *format, gint64 *minsize,
494 gint64 *maxsize, gboolean *async);
497 GstEvent* gst_event_new_qos (gdouble proportion, GstClockTimeDiff diff,
498 GstClockTime timestamp) G_GNUC_MALLOC;
499 GstEvent* gst_event_new_qos_full (GstQOSType type, gdouble proportion,
500 GstClockTimeDiff diff, GstClockTime timestamp) G_GNUC_MALLOC;
501 void gst_event_parse_qos (GstEvent *event, gdouble *proportion, GstClockTimeDiff *diff,
502 GstClockTime *timestamp);
503 void gst_event_parse_qos_full (GstEvent *event, GstQOSType *type,
504 gdouble *proportion, GstClockTimeDiff *diff,
505 GstClockTime *timestamp);
507 GstEvent* gst_event_new_seek (gdouble rate, GstFormat format, GstSeekFlags flags,
508 GstSeekType start_type, gint64 start,
509 GstSeekType stop_type, gint64 stop) G_GNUC_MALLOC;
510 void gst_event_parse_seek (GstEvent *event, gdouble *rate, GstFormat *format,
512 GstSeekType *start_type, gint64 *start,
513 GstSeekType *stop_type, gint64 *stop);
514 /* navigation event */
515 GstEvent* gst_event_new_navigation (GstStructure *structure) G_GNUC_MALLOC;
518 GstEvent* gst_event_new_latency (GstClockTime latency) G_GNUC_MALLOC;
519 void gst_event_parse_latency (GstEvent *event, GstClockTime *latency);
522 GstEvent* gst_event_new_step (GstFormat format, guint64 amount, gdouble rate,
523 gboolean flush, gboolean intermediate) G_GNUC_MALLOC;
524 void gst_event_parse_step (GstEvent *event, GstFormat *format, guint64 *amount,
525 gdouble *rate, gboolean *flush, gboolean *intermediate);
529 #endif /* __GST_EVENT_H__ */