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;
30 #include <gst/gstminiobject.h>
31 #include <gst/gstformat.h>
32 #include <gst/gstobject.h>
33 #include <gst/gstclock.h>
34 #include <gst/gstcaps.h>
35 #include <gst/gststructure.h>
36 #include <gst/gsttaglist.h>
42 * @GST_EVENT_TYPE_UPSTREAM: Set if the event can travel upstream.
43 * @GST_EVENT_TYPE_DOWNSTREAM: Set if the event can travel downstream.
44 * @GST_EVENT_TYPE_SERIALIZED: Set if the event should be serialized with data
46 * @GST_EVENT_TYPE_STICKY: Set if the event is sticky on the pads.
48 * #GstEventTypeFlags indicate the aspects of the different #GstEventType
49 * values. You can get the type flags of a #GstEventType with the
50 * gst_event_type_get_flags() function.
53 GST_EVENT_TYPE_UPSTREAM = 1 << 0,
54 GST_EVENT_TYPE_DOWNSTREAM = 1 << 1,
55 GST_EVENT_TYPE_SERIALIZED = 1 << 2,
56 GST_EVENT_TYPE_STICKY = 1 << 3
60 * GST_EVENT_TYPE_BOTH:
62 * The same thing as #GST_EVENT_TYPE_UPSTREAM | #GST_EVENT_TYPE_DOWNSTREAM.
64 #define GST_EVENT_TYPE_BOTH \
65 (GST_EVENT_TYPE_UPSTREAM | GST_EVENT_TYPE_DOWNSTREAM)
67 #define GST_EVENT_MAX_STICKY 16
68 #define GST_EVENT_STICKY_SHIFT 8
69 #define GST_EVENT_NUM_SHIFT (GST_EVENT_STICKY_SHIFT + 4)
72 * GST_EVENT_MAKE_TYPE:
73 * @num: the event number to create
74 * @idx: the index in the sticky array
75 * @flags: the event flags
77 * when making custom event types, use this macro with the num and
80 #define GST_EVENT_MAKE_TYPE(num,idx,flags) \
81 (((num) << GST_EVENT_NUM_SHIFT) | ((idx) << GST_EVENT_STICKY_SHIFT) | (flags))
83 #define FLAG(name) GST_EVENT_TYPE_##name
86 #define GST_EVENT_STICKY_IDX_TYPE(type) (((type) >> GST_EVENT_STICKY_SHIFT) & 0xf)
87 #define GST_EVENT_STICKY_IDX(ev) GST_EVENT_STICKY_IDX_TYPE(GST_EVENT_TYPE(ev))
91 * @GST_EVENT_UNKNOWN: unknown event.
92 * @GST_EVENT_FLUSH_START: Start a flush operation. This event clears all data
93 * from the pipeline and unblock all streaming threads.
94 * @GST_EVENT_FLUSH_STOP: Stop a flush operation. This event resets the
95 * running-time of the pipeline.
96 * @GST_EVENT_EOS: End-Of-Stream. No more data is to be expected to follow
97 * without a NEWSEGMENT event.
98 * @GST_EVENT_NEWSEGMENT: A new media segment follows in the dataflow. The
99 * segment events contains information for clipping buffers and
100 * converting buffer timestamps to running-time and
102 * @GST_EVENT_TAG: A new set of metadata tags has been found in the stream.
103 * @GST_EVENT_BUFFERSIZE: Notification of buffering requirements. Currently not
105 * @GST_EVENT_SINK_MESSAGE: An event that sinks turn into a message. Used to
106 * send messages that should be emitted in sync with
109 * @GST_EVENT_QOS: A quality message. Used to indicate to upstream elements
110 * that the downstream elements should adjust their processing
112 * @GST_EVENT_SEEK: A request for a new playback position and rate.
113 * @GST_EVENT_NAVIGATION: Navigation events are usually used for communicating
114 * user requests, such as mouse or keyboard movements,
115 * to upstream elements.
116 * @GST_EVENT_LATENCY: Notification of new latency adjustment. Sinks will use
117 * the latency information to adjust their synchronisation.
119 * @GST_EVENT_STEP: A request for stepping through the media. Sinks will usually
120 * execute the step operation. Since: 0.10.24
121 * @GST_EVENT_CUSTOM_UPSTREAM: Upstream custom event
122 * @GST_EVENT_CUSTOM_DOWNSTREAM: Downstream custom event that travels in the
124 * @GST_EVENT_CUSTOM_DOWNSTREAM_OOB: Custom out-of-band downstream event.
125 * @GST_EVENT_CUSTOM_BOTH: Custom upstream or downstream event.
126 * In-band when travelling downstream.
127 * @GST_EVENT_CUSTOM_BOTH_OOB: Custom upstream or downstream out-of-band event.
129 * #GstEventType lists the standard event types that can be sent in a pipeline.
131 * The custom event types can be used for private messages between elements
132 * that can't be expressed using normal
133 * GStreamer buffer passing semantics. Custom events carry an arbitrary
135 * Specific custom events are distinguished by the name of the structure.
137 /* NOTE: keep in sync with quark registration in gstevent.c */
139 GST_EVENT_UNKNOWN = GST_EVENT_MAKE_TYPE (0, 0, 0),
140 /* bidirectional events */
141 GST_EVENT_FLUSH_START = GST_EVENT_MAKE_TYPE (1, 0, FLAG(BOTH)),
142 GST_EVENT_FLUSH_STOP = GST_EVENT_MAKE_TYPE (2, 0, FLAG(BOTH) | FLAG(SERIALIZED)),
143 /* downstream serialized events */
144 GST_EVENT_EOS = GST_EVENT_MAKE_TYPE (5, 0, FLAG(DOWNSTREAM) | FLAG(SERIALIZED) | FLAG(STICKY)),
145 GST_EVENT_CAPS = GST_EVENT_MAKE_TYPE (6, 5, FLAG(DOWNSTREAM) | FLAG(SERIALIZED) | FLAG(STICKY)),
146 GST_EVENT_NEWSEGMENT = GST_EVENT_MAKE_TYPE (7, 1, FLAG(DOWNSTREAM) | FLAG(SERIALIZED) | FLAG(STICKY)),
147 GST_EVENT_TAG = GST_EVENT_MAKE_TYPE (8, 2, FLAG(DOWNSTREAM) | FLAG(SERIALIZED) | FLAG(STICKY)),
148 GST_EVENT_BUFFERSIZE = GST_EVENT_MAKE_TYPE (9, 3, FLAG(DOWNSTREAM) | FLAG(SERIALIZED) | FLAG(STICKY)),
149 GST_EVENT_SINK_MESSAGE = GST_EVENT_MAKE_TYPE (10, 4, FLAG(DOWNSTREAM) | FLAG(SERIALIZED) | FLAG(STICKY)),
150 /* upstream events */
151 GST_EVENT_QOS = GST_EVENT_MAKE_TYPE (15, 0, FLAG(UPSTREAM)),
152 GST_EVENT_SEEK = GST_EVENT_MAKE_TYPE (16, 0, FLAG(UPSTREAM)),
153 GST_EVENT_NAVIGATION = GST_EVENT_MAKE_TYPE (17, 0, FLAG(UPSTREAM)),
154 GST_EVENT_LATENCY = GST_EVENT_MAKE_TYPE (18, 0, FLAG(UPSTREAM)),
155 GST_EVENT_STEP = GST_EVENT_MAKE_TYPE (19, 0, FLAG(UPSTREAM)),
157 /* custom events start here */
158 GST_EVENT_CUSTOM_UPSTREAM = GST_EVENT_MAKE_TYPE (32, 0, FLAG(UPSTREAM)),
159 GST_EVENT_CUSTOM_DOWNSTREAM = GST_EVENT_MAKE_TYPE (32, 0, FLAG(DOWNSTREAM) | FLAG(SERIALIZED)),
160 GST_EVENT_CUSTOM_DOWNSTREAM_OOB = GST_EVENT_MAKE_TYPE (32, 0, FLAG(DOWNSTREAM)),
161 GST_EVENT_CUSTOM_BOTH = GST_EVENT_MAKE_TYPE (32, 0, FLAG(BOTH) | FLAG(SERIALIZED)),
162 GST_EVENT_CUSTOM_BOTH_OOB = GST_EVENT_MAKE_TYPE (32, 0, FLAG(BOTH))
167 * GST_EVENT_TRACE_NAME:
169 * The name used for memory allocation tracing
171 #define GST_EVENT_TRACE_NAME "GstEvent"
173 #define GST_TYPE_EVENT (gst_event_get_type())
174 #define GST_IS_EVENT(obj) (GST_IS_MINI_OBJECT_TYPE (obj, GST_TYPE_EVENT))
175 #define GST_EVENT(obj) ((GstEvent *)(obj))
176 #define GST_EVENT_CAST(obj) ((GstEvent *)(obj))
180 * @event: the event to query
182 * Get the #GstEventType of the event.
184 #define GST_EVENT_TYPE(event) (GST_EVENT_CAST(event)->type)
187 * GST_EVENT_TYPE_NAME:
188 * @event: the event to query
190 * Get a constant string representation of the #GstEventType of the event.
192 #define GST_EVENT_TYPE_NAME(event) (gst_event_type_get_name(GST_EVENT_TYPE(event)))
195 * GST_EVENT_TIMESTAMP:
196 * @event: the event to query
198 * Get the #GstClockTime timestamp of the event. This is the time when the event
201 #define GST_EVENT_TIMESTAMP(event) (GST_EVENT_CAST(event)->timestamp)
205 * @event: the event to query
207 * The sequence number of @event.
209 #define GST_EVENT_SEQNUM(event) (GST_EVENT_CAST(event)->seqnum)
212 * GST_EVENT_IS_UPSTREAM:
213 * @ev: the event to query
215 * Check if an event can travel upstream.
217 #define GST_EVENT_IS_UPSTREAM(ev) !!(GST_EVENT_TYPE (ev) & GST_EVENT_TYPE_UPSTREAM)
219 * GST_EVENT_IS_DOWNSTREAM:
220 * @ev: the event to query
222 * Check if an event can travel downstream.
224 #define GST_EVENT_IS_DOWNSTREAM(ev) !!(GST_EVENT_TYPE (ev) & GST_EVENT_TYPE_DOWNSTREAM)
226 * GST_EVENT_IS_SERIALIZED:
227 * @ev: the event to query
229 * Check if an event is serialized with the data stream.
231 #define GST_EVENT_IS_SERIALIZED(ev) !!(GST_EVENT_TYPE (ev) & GST_EVENT_TYPE_SERIALIZED)
233 * GST_EVENT_IS_STICKY:
234 * @ev: the event to query
236 * Check if an event is sticky on the pads.
238 #define GST_EVENT_IS_STICKY(ev) !!(GST_EVENT_TYPE (ev) & GST_EVENT_TYPE_STICKY)
242 * @old_event: (inout) (transfer full): pointer to a pointer to a #GstEvent
244 * @new_event: (allow-none) (transfer none): pointer to a #GstEvent that will
245 * replace the event pointed to by @old_event.
247 * Modifies a pointer to a #GstEvent to point to a different #GstEvent. The
248 * modification is done atomically (so this is useful for ensuring thread safety
249 * in some cases), and the reference counts are updated appropriately (the old
250 * event is unreffed, the new one is reffed).
252 * Either @new_event or the #GstEvent pointed to by @old_event may be NULL.
256 #define gst_event_replace(old_event,new_event) \
257 gst_mini_object_replace ((GstMiniObject **)(old_event), GST_MINI_OBJECT_CAST (new_event))
261 * @GST_SEEK_TYPE_NONE: no change in position is required
262 * @GST_SEEK_TYPE_CUR: change relative to currently configured segment. This
263 * can't be used to seek relative to the current playback position - do a
264 * position query, calculate the desired position and then do an absolute
265 * position seek instead if that's what you want to do.
266 * @GST_SEEK_TYPE_SET: absolute position is requested
267 * @GST_SEEK_TYPE_END: relative position to duration is requested
269 * The different types of seek events. When constructing a seek event with
270 * gst_event_new_seek(), a format, a seek method and optional flags are to
271 * be provided. The seek event is then inserted into the graph with
272 * gst_pad_send_event() or gst_element_send_event().
276 GST_SEEK_TYPE_NONE = 0,
277 GST_SEEK_TYPE_CUR = 1,
278 GST_SEEK_TYPE_SET = 2,
279 GST_SEEK_TYPE_END = 3
284 * @GST_SEEK_FLAG_NONE: no flag
285 * @GST_SEEK_FLAG_FLUSH: flush pipeline
286 * @GST_SEEK_FLAG_ACCURATE: accurate position is requested, this might
287 * be considerably slower for some formats.
288 * @GST_SEEK_FLAG_KEY_UNIT: seek to the nearest keyframe. This might be
289 * faster but less accurate.
290 * @GST_SEEK_FLAG_SEGMENT: perform a segment seek.
291 * @GST_SEEK_FLAG_SKIP: when doing fast foward or fast reverse playback, allow
292 * elements to skip frames instead of generating all
293 * frames. Since 0.10.22.
295 * Flags to be used with gst_element_seek() or gst_event_new_seek(). All flags
296 * can be used together.
298 * A non flushing seek might take some time to perform as the currently
299 * playing data in the pipeline will not be cleared.
301 * An accurate seek might be slower for formats that don't have any indexes
302 * or timestamp markers in the stream. Specifying this flag might require a
303 * complete scan of the file in those cases.
305 * When performing a segment seek: after the playback of the segment completes,
306 * no EOS will be emmited by the element that performed the seek, but a
307 * #GST_MESSAGE_SEGMENT_DONE message will be posted on the bus by the element.
308 * When this message is posted, it is possible to send a new seek event to
309 * continue playback. With this seek method it is possible to perform seemless
310 * looping or simple linear editing.
312 * When doing fast forward (rate > 1.0) or fast reverse (rate < -1.0) trickmode
313 * playback, the @GST_SEEK_FLAG_SKIP flag can be used to instruct decoders
314 * and demuxers to adjust the playback rate by skipping frames. This can improve
315 * performance and decrease CPU usage because not all frames need to be decoded.
317 * Also see part-seeking.txt in the GStreamer design documentation for more
318 * details on the meaning of these flags and the behaviour expected of
319 * elements that handle them.
322 GST_SEEK_FLAG_NONE = 0,
323 GST_SEEK_FLAG_FLUSH = (1 << 0),
324 GST_SEEK_FLAG_ACCURATE = (1 << 1),
325 GST_SEEK_FLAG_KEY_UNIT = (1 << 2),
326 GST_SEEK_FLAG_SEGMENT = (1 << 3),
327 GST_SEEK_FLAG_SKIP = (1 << 4)
332 * @GST_QOS_TYPE_OVERFLOW: The QoS event type that is produced when downstream
333 * elements are producing data too quickly and the element can't keep up
334 * processing the data. Upstream should reduce their processing rate. This
335 * type is also used when buffers arrive early or in time.
336 * @GST_QOS_TYPE_UNDERFLOW: The QoS event type that is produced when downstream
337 * elements are producing data too slowly and need to speed up their processing
339 * @GST_QOS_TYPE_THROTTLE: The QoS event type that is produced when the
340 * application enabled throttling to limit the datarate.
342 * The different types of QoS events that can be given to the
343 * gst_event_new_qos_full() method.
348 GST_QOS_TYPE_OVERFLOW = 0,
349 GST_QOS_TYPE_UNDERFLOW = 1,
350 GST_QOS_TYPE_THROTTLE = 2
355 * @mini_object: the parent structure
356 * @type: the #GstEventType of the event
357 * @timestamp: the timestamp of the event
358 * @structure: the #GstStructure containing the event info.
363 GstMiniObject mini_object;
365 /*< public >*/ /* with COW */
370 GstStructure *structure;
373 gpointer _gst_reserved[GST_PADDING];
376 const gchar* gst_event_type_get_name (GstEventType type);
377 GQuark gst_event_type_to_quark (GstEventType type);
379 gst_event_type_get_flags (GstEventType type);
382 GType gst_event_get_type (void);
387 * @event: The event to refcount
389 * Increase the refcount of this event.
391 * Returns: (transfer full): @event (for convenience when doing assignments)
393 #ifdef _FOOL_GTK_DOC_
394 G_INLINE_FUNC GstEvent * gst_event_ref (GstEvent * event);
397 static inline GstEvent *
398 gst_event_ref (GstEvent * event)
400 return (GstEvent *) gst_mini_object_ref (GST_MINI_OBJECT_CAST (event));
405 * @event: (transfer full): the event to refcount
407 * Decrease the refcount of an event, freeing it if the refcount reaches 0.
409 #ifdef _FOOL_GTK_DOC_
410 G_INLINE_FUNC void gst_event_unref (GstEvent * event);
414 gst_event_unref (GstEvent * event)
416 gst_mini_object_unref (GST_MINI_OBJECT_CAST (event));
422 * @event: The event to copy
424 * Copy the event using the event specific copy function.
426 * Returns: (transfer full): the new event
428 #ifdef _FOOL_GTK_DOC_
429 G_INLINE_FUNC GstEvent * gst_event_copy (const GstEvent * event);
432 static inline GstEvent *
433 gst_event_copy (const GstEvent * event)
435 return GST_EVENT_CAST (gst_mini_object_copy (GST_MINI_OBJECT_CONST_CAST (event)));
440 GstEvent* gst_event_new_custom (GstEventType type, GstStructure *structure);
443 gst_event_get_structure (GstEvent *event);
445 gboolean gst_event_has_name (GstEvent *event, const gchar *name);
447 /* identifiers for events and messages */
448 guint32 gst_event_get_seqnum (GstEvent *event);
449 void gst_event_set_seqnum (GstEvent *event, guint32 seqnum);
452 GstEvent * gst_event_new_flush_start (void);
453 GstEvent * gst_event_new_flush_stop (void);
456 GstEvent * gst_event_new_eos (void);
459 GstEvent * gst_event_new_caps (GstCaps *caps);
460 void gst_event_parse_caps (GstEvent *event, GstCaps **caps);
462 /* newsegment events */
463 GstEvent* gst_event_new_new_segment (gboolean update, gdouble rate,
465 gint64 start, gint64 stop,
467 GstEvent* gst_event_new_new_segment_full (gboolean update, gdouble rate,
468 gdouble applied_rate,
470 gint64 start, gint64 stop,
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);
488 void gst_event_parse_tag (GstEvent *event, GstTagList **taglist);
491 GstEvent * gst_event_new_buffer_size (GstFormat format, gint64 minsize, gint64 maxsize,
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);
499 GstEvent* gst_event_new_qos_full (GstQOSType type, gdouble proportion,
500 GstClockTimeDiff diff, GstClockTime timestamp);
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);
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);
518 GstEvent* gst_event_new_latency (GstClockTime latency);
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);
524 void gst_event_parse_step (GstEvent *event, GstFormat *format, guint64 *amount,
525 gdouble *rate, gboolean *flush, gboolean *intermediate);
529 #endif /* __GST_EVENT_H__ */