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
43 * @GST_EVENT_TYPE_STICKY: Set if the event is sticky on the pads.
45 * #GstEventTypeFlags indicate the aspects of the different #GstEventType
46 * values. You can get the type flags of a #GstEventType with the
47 * gst_event_type_get_flags() function.
50 GST_EVENT_TYPE_UPSTREAM = 1 << 0,
51 GST_EVENT_TYPE_DOWNSTREAM = 1 << 1,
52 GST_EVENT_TYPE_SERIALIZED = 1 << 2,
53 GST_EVENT_TYPE_STICKY = 1 << 3
57 * GST_EVENT_TYPE_BOTH:
59 * The same thing as #GST_EVENT_TYPE_UPSTREAM | #GST_EVENT_TYPE_DOWNSTREAM.
61 #define GST_EVENT_TYPE_BOTH \
62 (GST_EVENT_TYPE_UPSTREAM | GST_EVENT_TYPE_DOWNSTREAM)
64 #define GST_EVENT_STICKY_SHIFT 8
65 #define GST_EVENT_NUM_SHIFT 16
68 * GST_EVENT_MAKE_TYPE:
69 * @num: the event number to create
70 * @idx: the index in the sticky array
71 * @flags: the event flags
73 * when making custom event types, use this macro with the num and
76 #define GST_EVENT_MAKE_TYPE(num,idx,flags) \
77 (((num) << GST_EVENT_NUM_SHIFT) | ((idx) << GST_EVENT_STICKY_SHIFT) | (flags))
79 #define FLAG(name) GST_EVENT_TYPE_##name
81 #define GST_EVENT_STICKY_IDX(ev) ((GST_EVENT_TYPE(ev) >> GST_EVENT_STICKY_SHIFT) & 0xff)
85 * @GST_EVENT_UNKNOWN: unknown event.
86 * @GST_EVENT_FLUSH_START: Start a flush operation. This event clears all data
87 * from the pipeline and unblock all streaming threads.
88 * @GST_EVENT_FLUSH_STOP: Stop a flush operation. This event resets the
89 * running-time of the pipeline.
90 * @GST_EVENT_EOS: End-Of-Stream. No more data is to be expected to follow
91 * without a NEWSEGMENT event.
92 * @GST_EVENT_NEWSEGMENT: A new media segment follows in the dataflow. The
93 * segment events contains information for clipping buffers and
94 * converting buffer timestamps to running-time and
96 * @GST_EVENT_TAG: A new set of metadata tags has been found in the stream.
97 * @GST_EVENT_BUFFERSIZE: Notification of buffering requirements. Currently not
99 * @GST_EVENT_SINK_MESSAGE: An event that sinks turn into a message. Used to
100 * send messages that should be emitted in sync with
103 * @GST_EVENT_QOS: A quality message. Used to indicate to upstream elements
104 * that the downstream elements should adjust their processing
106 * @GST_EVENT_SEEK: A request for a new playback position and rate.
107 * @GST_EVENT_NAVIGATION: Navigation events are usually used for communicating
108 * user requests, such as mouse or keyboard movements,
109 * to upstream elements.
110 * @GST_EVENT_LATENCY: Notification of new latency adjustment. Sinks will use
111 * the latency information to adjust their synchronisation.
113 * @GST_EVENT_STEP: A request for stepping through the media. Sinks will usually
114 * execute the step operation. Since: 0.10.24
115 * @GST_EVENT_CUSTOM_UPSTREAM: Upstream custom event
116 * @GST_EVENT_CUSTOM_DOWNSTREAM: Downstream custom event that travels in the
118 * @GST_EVENT_CUSTOM_DOWNSTREAM_OOB: Custom out-of-band downstream event.
119 * @GST_EVENT_CUSTOM_BOTH: Custom upstream or downstream event.
120 * In-band when travelling downstream.
121 * @GST_EVENT_CUSTOM_BOTH_OOB: Custom upstream or downstream out-of-band event.
123 * #GstEventType lists the standard event types that can be sent in a pipeline.
125 * The custom event types can be used for private messages between elements
126 * that can't be expressed using normal
127 * GStreamer buffer passing semantics. Custom events carry an arbitrary
129 * Specific custom events are distinguished by the name of the structure.
131 /* NOTE: keep in sync with quark registration in gstevent.c */
133 GST_EVENT_UNKNOWN = GST_EVENT_MAKE_TYPE (0, 0, 0),
134 /* bidirectional events */
135 GST_EVENT_FLUSH_START = GST_EVENT_MAKE_TYPE (1, 0, FLAG(BOTH)),
136 GST_EVENT_FLUSH_STOP = GST_EVENT_MAKE_TYPE (2, 0, FLAG(BOTH) | FLAG(SERIALIZED)),
137 /* downstream serialized events */
138 GST_EVENT_EOS = GST_EVENT_MAKE_TYPE (5, 0, FLAG(DOWNSTREAM) | FLAG(SERIALIZED) | FLAG(STICKY)),
139 GST_EVENT_NEWSEGMENT = GST_EVENT_MAKE_TYPE (6, 1, FLAG(DOWNSTREAM) | FLAG(SERIALIZED) | FLAG(STICKY)),
140 GST_EVENT_TAG = GST_EVENT_MAKE_TYPE (7, 2, FLAG(DOWNSTREAM) | FLAG(SERIALIZED) | FLAG(STICKY)),
141 GST_EVENT_BUFFERSIZE = GST_EVENT_MAKE_TYPE (8, 3, FLAG(DOWNSTREAM) | FLAG(SERIALIZED) | FLAG(STICKY)),
142 GST_EVENT_SINK_MESSAGE = GST_EVENT_MAKE_TYPE (9, 4, FLAG(DOWNSTREAM) | FLAG(SERIALIZED) | FLAG(STICKY)),
143 /* upstream events */
144 GST_EVENT_QOS = GST_EVENT_MAKE_TYPE (15, 0, FLAG(UPSTREAM)),
145 GST_EVENT_SEEK = GST_EVENT_MAKE_TYPE (16, 0, FLAG(UPSTREAM)),
146 GST_EVENT_NAVIGATION = GST_EVENT_MAKE_TYPE (17, 0, FLAG(UPSTREAM)),
147 GST_EVENT_LATENCY = GST_EVENT_MAKE_TYPE (18, 0, FLAG(UPSTREAM)),
148 GST_EVENT_STEP = GST_EVENT_MAKE_TYPE (19, 0, FLAG(UPSTREAM)),
150 /* custom events start here */
151 GST_EVENT_CUSTOM_UPSTREAM = GST_EVENT_MAKE_TYPE (32, 0, FLAG(UPSTREAM)),
152 GST_EVENT_CUSTOM_DOWNSTREAM = GST_EVENT_MAKE_TYPE (32, 0, FLAG(DOWNSTREAM) | FLAG(SERIALIZED)),
153 GST_EVENT_CUSTOM_DOWNSTREAM_OOB = GST_EVENT_MAKE_TYPE (32, 0, FLAG(DOWNSTREAM)),
154 GST_EVENT_CUSTOM_BOTH = GST_EVENT_MAKE_TYPE (32, 0, FLAG(BOTH) | FLAG(SERIALIZED)),
155 GST_EVENT_CUSTOM_BOTH_OOB = GST_EVENT_MAKE_TYPE (32, 0, FLAG(BOTH))
160 * GST_EVENT_TRACE_NAME:
162 * The name used for memory allocation tracing
164 #define GST_EVENT_TRACE_NAME "GstEvent"
166 typedef struct _GstEvent GstEvent;
168 #define GST_TYPE_EVENT (gst_event_get_type())
169 #define GST_IS_EVENT(obj) (GST_IS_MINI_OBJECT_TYPE (obj, GST_TYPE_EVENT))
170 #define GST_EVENT(obj) ((GstEvent *)(obj))
171 #define GST_EVENT_CAST(obj) ((GstEvent *)(obj))
175 * @event: the event to query
177 * Get the #GstEventType of the event.
179 #define GST_EVENT_TYPE(event) (GST_EVENT_CAST(event)->type)
182 * GST_EVENT_TYPE_NAME:
183 * @event: the event to query
185 * Get a constant string representation of the #GstEventType of the event.
187 #define GST_EVENT_TYPE_NAME(event) (gst_event_type_get_name(GST_EVENT_TYPE(event)))
190 * GST_EVENT_TIMESTAMP:
191 * @event: the event to query
193 * Get the #GstClockTime timestamp of the event. This is the time when the event
196 #define GST_EVENT_TIMESTAMP(event) (GST_EVENT_CAST(event)->timestamp)
200 * @event: the event to query
202 * The sequence number of @event.
204 #define GST_EVENT_SEQNUM(event) (GST_EVENT_CAST(event)->seqnum)
207 * GST_EVENT_IS_UPSTREAM:
208 * @ev: the event to query
210 * Check if an event can travel upstream.
212 #define GST_EVENT_IS_UPSTREAM(ev) !!(GST_EVENT_TYPE (ev) & GST_EVENT_TYPE_UPSTREAM)
214 * GST_EVENT_IS_DOWNSTREAM:
215 * @ev: the event to query
217 * Check if an event can travel downstream.
219 #define GST_EVENT_IS_DOWNSTREAM(ev) !!(GST_EVENT_TYPE (ev) & GST_EVENT_TYPE_DOWNSTREAM)
221 * GST_EVENT_IS_SERIALIZED:
222 * @ev: the event to query
224 * Check if an event is serialized with the data stream.
226 #define GST_EVENT_IS_SERIALIZED(ev) !!(GST_EVENT_TYPE (ev) & GST_EVENT_TYPE_SERIALIZED)
228 * GST_EVENT_IS_STICKY:
229 * @ev: the event to query
231 * Check if an event is sticky on the pads.
233 #define GST_EVENT_IS_STICKY(ev) !!(GST_EVENT_TYPE (ev) & GST_EVENT_TYPE_STICKY)
237 * @old_event: (inout) (transfer full): pointer to a pointer to a #GstEvent
239 * @new_event: (allow-none) (transfer none): pointer to a #GstEvent that will
240 * replace the event pointed to by @old_event.
242 * Modifies a pointer to a #GstEvent to point to a different #GstEvent. The
243 * modification is done atomically (so this is useful for ensuring thread safety
244 * in some cases), and the reference counts are updated appropriately (the old
245 * event is unreffed, the new one is reffed).
247 * Either @new_event or the #GstEvent pointed to by @old_event may be NULL.
251 #define gst_event_replace(old_event,new_event) \
252 gst_mini_object_replace ((GstMiniObject **)(old_event), GST_MINI_OBJECT_CAST (new_event))
256 * @GST_SEEK_TYPE_NONE: no change in position is required
257 * @GST_SEEK_TYPE_CUR: change relative to currently configured segment. This
258 * can't be used to seek relative to the current playback position - do a
259 * position query, calculate the desired position and then do an absolute
260 * position seek instead if that's what you want to do.
261 * @GST_SEEK_TYPE_SET: absolute position is requested
262 * @GST_SEEK_TYPE_END: relative position to duration is requested
264 * The different types of seek events. When constructing a seek event with
265 * gst_event_new_seek(), a format, a seek method and optional flags are to
266 * be provided. The seek event is then inserted into the graph with
267 * gst_pad_send_event() or gst_element_send_event().
271 GST_SEEK_TYPE_NONE = 0,
272 GST_SEEK_TYPE_CUR = 1,
273 GST_SEEK_TYPE_SET = 2,
274 GST_SEEK_TYPE_END = 3
279 * @GST_SEEK_FLAG_NONE: no flag
280 * @GST_SEEK_FLAG_FLUSH: flush pipeline
281 * @GST_SEEK_FLAG_ACCURATE: accurate position is requested, this might
282 * be considerably slower for some formats.
283 * @GST_SEEK_FLAG_KEY_UNIT: seek to the nearest keyframe. This might be
284 * faster but less accurate.
285 * @GST_SEEK_FLAG_SEGMENT: perform a segment seek.
286 * @GST_SEEK_FLAG_SKIP: when doing fast foward or fast reverse playback, allow
287 * elements to skip frames instead of generating all
288 * frames. Since 0.10.22.
290 * Flags to be used with gst_element_seek() or gst_event_new_seek(). All flags
291 * can be used together.
293 * A non flushing seek might take some time to perform as the currently
294 * playing data in the pipeline will not be cleared.
296 * An accurate seek might be slower for formats that don't have any indexes
297 * or timestamp markers in the stream. Specifying this flag might require a
298 * complete scan of the file in those cases.
300 * When performing a segment seek: after the playback of the segment completes,
301 * no EOS will be emmited by the element that performed the seek, but a
302 * #GST_MESSAGE_SEGMENT_DONE message will be posted on the bus by the element.
303 * When this message is posted, it is possible to send a new seek event to
304 * continue playback. With this seek method it is possible to perform seemless
305 * looping or simple linear editing.
307 * When doing fast forward (rate > 1.0) or fast reverse (rate < -1.0) trickmode
308 * playback, the @GST_SEEK_FLAG_SKIP flag can be used to instruct decoders
309 * and demuxers to adjust the playback rate by skipping frames. This can improve
310 * performance and decrease CPU usage because not all frames need to be decoded.
312 * Also see part-seeking.txt in the GStreamer design documentation for more
313 * details on the meaning of these flags and the behaviour expected of
314 * elements that handle them.
317 GST_SEEK_FLAG_NONE = 0,
318 GST_SEEK_FLAG_FLUSH = (1 << 0),
319 GST_SEEK_FLAG_ACCURATE = (1 << 1),
320 GST_SEEK_FLAG_KEY_UNIT = (1 << 2),
321 GST_SEEK_FLAG_SEGMENT = (1 << 3),
322 GST_SEEK_FLAG_SKIP = (1 << 4)
327 * @GST_QOS_TYPE_OVERFLOW: The QoS event type that is produced when downstream
328 * elements are producing data too quickly and the element can't keep up
329 * processing the data. Upstream should reduce their processing rate. This
330 * type is also used when buffers arrive early or in time.
331 * @GST_QOS_TYPE_UNDERFLOW: The QoS event type that is produced when downstream
332 * elements are producing data too slowly and need to speed up their processing
334 * @GST_QOS_TYPE_THROTTLE: The QoS event type that is produced when the
335 * application enabled throttling to limit the datarate.
337 * The different types of QoS events that can be given to the
338 * gst_event_new_qos_full() method.
343 GST_QOS_TYPE_OVERFLOW = 0,
344 GST_QOS_TYPE_UNDERFLOW = 1,
345 GST_QOS_TYPE_THROTTLE = 2
350 * @mini_object: the parent structure
351 * @type: the #GstEventType of the event
352 * @timestamp: the timestamp of the event
353 * @structure: the #GstStructure containing the event info.
358 GstMiniObject mini_object;
360 /*< public >*/ /* with COW */
365 GstStructure *structure;
368 gpointer _gst_reserved[GST_PADDING];
371 const gchar* gst_event_type_get_name (GstEventType type);
372 GQuark gst_event_type_to_quark (GstEventType type);
374 gst_event_type_get_flags (GstEventType type);
377 GType gst_event_get_type (void);
382 * @event: The event to refcount
384 * Increase the refcount of this event.
386 * Returns: (transfer full): @event (for convenience when doing assignments)
388 #ifdef _FOOL_GTK_DOC_
389 G_INLINE_FUNC GstEvent * gst_event_ref (GstEvent * event);
392 static inline GstEvent *
393 gst_event_ref (GstEvent * event)
395 return (GstEvent *) gst_mini_object_ref (GST_MINI_OBJECT_CAST (event));
400 * @event: (transfer full): the event to refcount
402 * Decrease the refcount of an event, freeing it if the refcount reaches 0.
404 #ifdef _FOOL_GTK_DOC_
405 G_INLINE_FUNC void gst_event_unref (GstEvent * event);
409 gst_event_unref (GstEvent * event)
411 gst_mini_object_unref (GST_MINI_OBJECT_CAST (event));
417 * @event: The event to copy
419 * Copy the event using the event specific copy function.
421 * Returns: (transfer full): the new event
423 #ifdef _FOOL_GTK_DOC_
424 G_INLINE_FUNC GstEvent * gst_event_copy (const GstEvent * event);
427 static inline GstEvent *
428 gst_event_copy (const GstEvent * event)
430 return GST_EVENT_CAST (gst_mini_object_copy (GST_MINI_OBJECT_CONST_CAST (event)));
435 GstEvent* gst_event_new_custom (GstEventType type, GstStructure *structure);
438 gst_event_get_structure (GstEvent *event);
440 gboolean gst_event_has_name (GstEvent *event, const gchar *name);
442 /* identifiers for events and messages */
443 guint32 gst_event_get_seqnum (GstEvent *event);
444 void gst_event_set_seqnum (GstEvent *event, guint32 seqnum);
447 GstEvent * gst_event_new_flush_start (void);
448 GstEvent * gst_event_new_flush_stop (void);
451 GstEvent * gst_event_new_eos (void);
453 /* newsegment events */
454 GstEvent* gst_event_new_new_segment (gboolean update, gdouble rate,
456 gint64 start, gint64 stop,
458 GstEvent* gst_event_new_new_segment_full (gboolean update, gdouble rate,
459 gdouble applied_rate,
461 gint64 start, gint64 stop,
463 void gst_event_parse_new_segment (GstEvent *event,
467 gint64 *start, gint64 *stop,
469 void gst_event_parse_new_segment_full (GstEvent *event,
472 gdouble *applied_rate,
474 gint64 *start, gint64 *stop,
478 GstEvent* gst_event_new_tag (GstTagList *taglist);
479 void gst_event_parse_tag (GstEvent *event, GstTagList **taglist);
482 GstEvent * gst_event_new_buffer_size (GstFormat format, gint64 minsize, gint64 maxsize,
484 void gst_event_parse_buffer_size (GstEvent *event, GstFormat *format, gint64 *minsize,
485 gint64 *maxsize, gboolean *async);
488 GstEvent* gst_event_new_qos (gdouble proportion, GstClockTimeDiff diff,
489 GstClockTime timestamp);
490 GstEvent* gst_event_new_qos_full (GstQOSType type, gdouble proportion,
491 GstClockTimeDiff diff, GstClockTime timestamp);
492 void gst_event_parse_qos (GstEvent *event, gdouble *proportion, GstClockTimeDiff *diff,
493 GstClockTime *timestamp);
494 void gst_event_parse_qos_full (GstEvent *event, GstQOSType *type,
495 gdouble *proportion, GstClockTimeDiff *diff,
496 GstClockTime *timestamp);
498 GstEvent* gst_event_new_seek (gdouble rate, GstFormat format, GstSeekFlags flags,
499 GstSeekType start_type, gint64 start,
500 GstSeekType stop_type, gint64 stop);
501 void gst_event_parse_seek (GstEvent *event, gdouble *rate, GstFormat *format,
503 GstSeekType *start_type, gint64 *start,
504 GstSeekType *stop_type, gint64 *stop);
505 /* navigation event */
506 GstEvent* gst_event_new_navigation (GstStructure *structure);
509 GstEvent* gst_event_new_latency (GstClockTime latency);
510 void gst_event_parse_latency (GstEvent *event, GstClockTime *latency);
513 GstEvent* gst_event_new_step (GstFormat format, guint64 amount, gdouble rate,
514 gboolean flush, gboolean intermediate);
515 void gst_event_parse_step (GstEvent *event, GstFormat *format, guint64 *amount,
516 gdouble *rate, gboolean *flush, gboolean *intermediate);
520 #endif /* __GST_EVENT_H__ */