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.c: 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., 51 Franklin St, Fifth Floor,
21 * Boston, MA 02110-1301, USA.
26 * @short_description: Structure describing events that are passed up and down
28 * @see_also: #GstPad, #GstElement
30 * The event class provides factory methods to construct events for sending
31 * and functions to query (parse) received events.
33 * Events are usually created with gst_event_new_*() which takes event-type
34 * specific parameters as arguments.
35 * To send an event application will usually use gst_element_send_event() and
36 * elements will use gst_pad_send_event() or gst_pad_push_event().
37 * The event should be unreffed with gst_event_unref() if it has not been sent.
39 * Events that have been received can be parsed with their respective
40 * gst_event_parse_*() functions. It is valid to pass %NULL for unwanted details.
42 * Events are passed between elements in parallel to the data stream. Some events
43 * are serialized with buffers, others are not. Some events only travel downstream,
44 * others only upstream. Some events can travel both upstream and downstream.
46 * The events are used to signal special conditions in the datastream such as
47 * EOS (end of stream) or the start of a new stream-segment.
48 * Events are also used to flush the pipeline of any pending data.
50 * Most of the event API is used inside plugins. Applications usually only
51 * construct and use seek events.
52 * To do that gst_event_new_seek() is used to create a seek event. It takes
53 * the needed parameters to specify seeking time and mode.
55 * <title>performing a seek on a pipeline</title>
60 * // construct a seek event to play the media from second 2 to 5, flush
61 * // the pipeline to decrease latency.
62 * event = gst_event_new_seek (1.0,
64 * GST_SEEK_FLAG_FLUSH,
65 * GST_SEEK_TYPE_SET, 2 * GST_SECOND,
66 * GST_SEEK_TYPE_SET, 5 * GST_SECOND);
68 * result = gst_element_send_event (pipeline, event);
70 * g_warning ("seek failed");
75 * Last reviewed on 2012-03-28 (0.11.3)
79 #include "gst_private.h"
80 #include <string.h> /* memcpy */
84 #include "gstenumtypes.h"
89 GType _gst_event_type = 0;
95 GstStructure *structure;
98 #define GST_EVENT_STRUCTURE(e) (((GstEventImpl *)(e))->structure)
107 static GstEventQuarks event_quarks[] = {
108 {GST_EVENT_UNKNOWN, "unknown", 0},
109 {GST_EVENT_FLUSH_START, "flush-start", 0},
110 {GST_EVENT_FLUSH_STOP, "flush-stop", 0},
111 {GST_EVENT_STREAM_START, "stream-start", 0},
112 {GST_EVENT_CAPS, "caps", 0},
113 {GST_EVENT_SEGMENT, "segment", 0},
114 {GST_EVENT_TAG, "tag", 0},
115 {GST_EVENT_TOC, "toc", 0},
116 {GST_EVENT_BUFFERSIZE, "buffersize", 0},
117 {GST_EVENT_SINK_MESSAGE, "sink-message", 0},
118 {GST_EVENT_EOS, "eos", 0},
119 {GST_EVENT_SEGMENT_DONE, "segment-done", 0},
120 {GST_EVENT_GAP, "gap", 0},
121 {GST_EVENT_QOS, "qos", 0},
122 {GST_EVENT_SEEK, "seek", 0},
123 {GST_EVENT_NAVIGATION, "navigation", 0},
124 {GST_EVENT_LATENCY, "latency", 0},
125 {GST_EVENT_STEP, "step", 0},
126 {GST_EVENT_RECONFIGURE, "reconfigure", 0},
127 {GST_EVENT_TOC_SELECT, "toc-select", 0},
128 {GST_EVENT_CUSTOM_UPSTREAM, "custom-upstream", 0},
129 {GST_EVENT_CUSTOM_DOWNSTREAM, "custom-downstream", 0},
130 {GST_EVENT_CUSTOM_DOWNSTREAM_OOB, "custom-downstream-oob", 0},
131 {GST_EVENT_CUSTOM_DOWNSTREAM_STICKY, "custom-downstream-sticky", 0},
132 {GST_EVENT_CUSTOM_BOTH, "custom-both", 0},
133 {GST_EVENT_CUSTOM_BOTH_OOB, "custom-both-oob", 0},
138 GST_DEFINE_MINI_OBJECT_TYPE (GstEvent, gst_event);
141 _priv_gst_event_initialize (void)
145 _gst_event_type = gst_event_get_type ();
147 g_type_class_ref (gst_seek_flags_get_type ());
148 g_type_class_ref (gst_seek_type_get_type ());
150 for (i = 0; event_quarks[i].name; i++) {
151 event_quarks[i].quark = g_quark_from_static_string (event_quarks[i].name);
156 * gst_event_type_get_name:
157 * @type: the event type
159 * Get a printable name for the given event type. Do not modify or free.
161 * Returns: a reference to the static name of the event.
164 gst_event_type_get_name (GstEventType type)
168 for (i = 0; event_quarks[i].name; i++) {
169 if (type == event_quarks[i].type)
170 return event_quarks[i].name;
176 * gst_event_type_to_quark:
177 * @type: the event type
179 * Get the unique quark for the given event type.
181 * Returns: the quark associated with the event type
184 gst_event_type_to_quark (GstEventType type)
188 for (i = 0; event_quarks[i].name; i++) {
189 if (type == event_quarks[i].type)
190 return event_quarks[i].quark;
196 * gst_event_type_get_flags:
197 * @type: a #GstEventType
199 * Gets the #GstEventTypeFlags associated with @type.
201 * Returns: a #GstEventTypeFlags.
204 gst_event_type_get_flags (GstEventType type)
206 GstEventTypeFlags ret;
208 ret = type & ((1 << GST_EVENT_NUM_SHIFT) - 1);
214 _gst_event_free (GstEvent * event)
218 g_return_if_fail (event != NULL);
219 g_return_if_fail (GST_IS_EVENT (event));
221 GST_CAT_LOG (GST_CAT_EVENT, "freeing event %p type %s", event,
222 GST_EVENT_TYPE_NAME (event));
224 s = GST_EVENT_STRUCTURE (event);
227 gst_structure_set_parent_refcount (s, NULL);
228 gst_structure_free (s);
231 g_slice_free1 (sizeof (GstEventImpl), event);
234 static void gst_event_init (GstEventImpl * event, GstEventType type);
237 _gst_event_copy (GstEvent * event)
242 copy = g_slice_new0 (GstEventImpl);
244 gst_event_init (copy, GST_EVENT_TYPE (event));
246 GST_EVENT_TIMESTAMP (copy) = GST_EVENT_TIMESTAMP (event);
247 GST_EVENT_SEQNUM (copy) = GST_EVENT_SEQNUM (event);
249 s = GST_EVENT_STRUCTURE (event);
251 GST_EVENT_STRUCTURE (copy) = gst_structure_copy (s);
252 gst_structure_set_parent_refcount (GST_EVENT_STRUCTURE (copy),
253 ©->event.mini_object.refcount);
255 GST_EVENT_STRUCTURE (copy) = NULL;
257 return GST_EVENT_CAST (copy);
261 gst_event_init (GstEventImpl * event, GstEventType type)
263 gst_mini_object_init (GST_MINI_OBJECT_CAST (event), 0, _gst_event_type,
264 (GstMiniObjectCopyFunction) _gst_event_copy, NULL,
265 (GstMiniObjectFreeFunction) _gst_event_free);
267 GST_EVENT_TYPE (event) = type;
268 GST_EVENT_TIMESTAMP (event) = GST_CLOCK_TIME_NONE;
269 GST_EVENT_SEQNUM (event) = gst_util_seqnum_next ();
274 * gst_event_new_custom:
275 * @type: The type of the new event
276 * @structure: (transfer full): the structure for the event. The event will
277 * take ownership of the structure.
279 * Create a new custom-typed event. This can be used for anything not
280 * handled by other event-specific functions to pass an event to another
283 * Make sure to allocate an event type with the #GST_EVENT_MAKE_TYPE macro,
284 * assigning a free number and filling in the correct direction and
285 * serialization flags.
287 * New custom events can also be created by subclassing the event type if
290 * Returns: (transfer full): the new custom event.
293 gst_event_new_custom (GstEventType type, GstStructure * structure)
297 event = g_slice_new0 (GstEventImpl);
299 GST_CAT_DEBUG (GST_CAT_EVENT, "creating new event %p %s %d", event,
300 gst_event_type_get_name (type), type);
303 /* structure must not have a parent */
304 if (!gst_structure_set_parent_refcount (structure,
305 &event->event.mini_object.refcount))
309 gst_event_init (event, type);
311 GST_EVENT_STRUCTURE (event) = structure;
313 return GST_EVENT_CAST (event);
318 g_slice_free1 (sizeof (GstEventImpl), event);
319 g_warning ("structure is already owned by another object");
325 * gst_event_get_structure:
326 * @event: The #GstEvent.
328 * Access the structure of the event.
330 * Returns: The structure of the event. The structure is still
331 * owned by the event, which means that you should not free it and
332 * that the pointer becomes invalid when you free the event.
337 gst_event_get_structure (GstEvent * event)
339 g_return_val_if_fail (GST_IS_EVENT (event), NULL);
341 return GST_EVENT_STRUCTURE (event);
345 * gst_event_writable_structure:
346 * @event: The #GstEvent.
348 * Get a writable version of the structure.
350 * Returns: The structure of the event. The structure is still
351 * owned by the event, which means that you should not free it and
352 * that the pointer becomes invalid when you free the event.
353 * This function checks if @event is writable and will never return NULL.
358 gst_event_writable_structure (GstEvent * event)
360 GstStructure *structure;
362 g_return_val_if_fail (GST_IS_EVENT (event), NULL);
363 g_return_val_if_fail (gst_event_is_writable (event), NULL);
365 structure = GST_EVENT_STRUCTURE (event);
367 if (structure == NULL) {
369 gst_structure_new_id_empty (gst_event_type_to_quark (GST_EVENT_TYPE
371 gst_structure_set_parent_refcount (structure, &event->mini_object.refcount);
372 GST_EVENT_STRUCTURE (event) = structure;
378 * gst_event_has_name:
379 * @event: The #GstEvent.
380 * @name: name to check
382 * Checks if @event has the given @name. This function is usually used to
383 * check the name of a custom event.
385 * Returns: %TRUE if @name matches the name of the event structure.
388 gst_event_has_name (GstEvent * event, const gchar * name)
390 g_return_val_if_fail (GST_IS_EVENT (event), FALSE);
392 if (GST_EVENT_STRUCTURE (event) == NULL)
395 return gst_structure_has_name (GST_EVENT_STRUCTURE (event), name);
399 * gst_event_get_seqnum:
400 * @event: A #GstEvent.
402 * Retrieve the sequence number of a event.
404 * Events have ever-incrementing sequence numbers, which may also be set
405 * explicitly via gst_event_set_seqnum(). Sequence numbers are typically used to
406 * indicate that a event corresponds to some other set of events or messages,
407 * for example an EOS event corresponding to a SEEK event. It is considered good
408 * practice to make this correspondence when possible, though it is not
411 * Note that events and messages share the same sequence number incrementor;
412 * two events or messages will never have the same sequence number unless
413 * that correspondence was made explicitly.
415 * Returns: The event's sequence number.
420 gst_event_get_seqnum (GstEvent * event)
422 g_return_val_if_fail (GST_IS_EVENT (event), -1);
424 return GST_EVENT_SEQNUM (event);
428 * gst_event_set_seqnum:
429 * @event: A #GstEvent.
430 * @seqnum: A sequence number.
432 * Set the sequence number of a event.
434 * This function might be called by the creator of a event to indicate that the
435 * event relates to other events or messages. See gst_event_get_seqnum() for
441 gst_event_set_seqnum (GstEvent * event, guint32 seqnum)
443 g_return_if_fail (GST_IS_EVENT (event));
445 GST_EVENT_SEQNUM (event) = seqnum;
449 * gst_event_new_flush_start:
451 * Allocate a new flush start event. The flush start event can be sent
452 * upstream and downstream and travels out-of-bounds with the dataflow.
454 * It marks pads as being flushing and will make them return
455 * #GST_FLOW_FLUSHING when used for data flow with gst_pad_push(),
456 * gst_pad_chain(), gst_pad_get_range() and gst_pad_pull_range().
457 * Any event (except a #GST_EVENT_FLUSH_STOP) received
458 * on a flushing pad will return %FALSE immediately.
460 * Elements should unlock any blocking functions and exit their streaming
461 * functions as fast as possible when this event is received.
463 * This event is typically generated after a seek to flush out all queued data
464 * in the pipeline so that the new media is played as soon as possible.
466 * Returns: (transfer full): a new flush start event.
469 gst_event_new_flush_start (void)
471 return gst_event_new_custom (GST_EVENT_FLUSH_START, NULL);
475 * gst_event_new_flush_stop:
476 * @reset_time: if time should be reset
478 * Allocate a new flush stop event. The flush stop event can be sent
479 * upstream and downstream and travels serialized with the dataflow.
480 * It is typically sent after sending a FLUSH_START event to make the
481 * pads accept data again.
483 * Elements can process this event synchronized with the dataflow since
484 * the preceeding FLUSH_START event stopped the dataflow.
486 * This event is typically generated to complete a seek and to resume
489 * Returns: (transfer full): a new flush stop event.
492 gst_event_new_flush_stop (gboolean reset_time)
496 GST_CAT_INFO (GST_CAT_EVENT, "creating flush stop %d", reset_time);
498 event = gst_event_new_custom (GST_EVENT_FLUSH_STOP,
499 gst_structure_new_id (GST_QUARK (EVENT_FLUSH_STOP),
500 GST_QUARK (RESET_TIME), G_TYPE_BOOLEAN, reset_time, NULL));
506 * gst_event_parse_flush_stop:
507 * @event: The event to parse
508 * @reset_time: (out): if time should be reset
510 * Parse the FLUSH_STOP event and retrieve the @reset_time member.
513 gst_event_parse_flush_stop (GstEvent * event, gboolean * reset_time)
515 GstStructure *structure;
517 g_return_if_fail (GST_IS_EVENT (event));
518 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_FLUSH_STOP);
520 structure = GST_EVENT_STRUCTURE (event);
521 if (G_LIKELY (reset_time))
523 g_value_get_boolean (gst_structure_id_get_value (structure,
524 GST_QUARK (RESET_TIME)));
530 * Create a new EOS event. The eos event can only travel downstream
531 * synchronized with the buffer flow. Elements that receive the EOS
532 * event on a pad can return #GST_FLOW_EOS as a #GstFlowReturn
533 * when data after the EOS event arrives.
535 * The EOS event will travel down to the sink elements in the pipeline
536 * which will then post the #GST_MESSAGE_EOS on the bus after they have
537 * finished playing any buffered data.
539 * When all sinks have posted an EOS message, an EOS message is
540 * forwarded to the application.
542 * The EOS event itself will not cause any state transitions of the pipeline.
544 * Returns: (transfer full): the new EOS event.
547 gst_event_new_eos (void)
549 return gst_event_new_custom (GST_EVENT_EOS, NULL);
554 * @timestamp: the start time (pts) of the gap
555 * @duration: the duration of the gap
557 * Create a new GAP event. A gap event can be thought of as conceptually
558 * equivalent to a buffer to signal that there is no data for a certain
559 * amount of time. This is useful to signal a gap to downstream elements
560 * which may wait for data, such as muxers or mixers or overlays, especially
561 * for sparse streams such as subtitle streams.
563 * Returns: (transfer full): the new GAP event.
566 gst_event_new_gap (GstClockTime timestamp, GstClockTime duration)
570 g_return_val_if_fail (GST_CLOCK_TIME_IS_VALID (timestamp), NULL);
572 GST_CAT_TRACE (GST_CAT_EVENT, "creating gap %" GST_TIME_FORMAT " - "
573 "%" GST_TIME_FORMAT " (duration: %" GST_TIME_FORMAT ")",
574 GST_TIME_ARGS (timestamp), GST_TIME_ARGS (timestamp + duration),
575 GST_TIME_ARGS (duration));
577 event = gst_event_new_custom (GST_EVENT_GAP,
578 gst_structure_new_id (GST_QUARK (EVENT_GAP),
579 GST_QUARK (TIMESTAMP), GST_TYPE_CLOCK_TIME, timestamp,
580 GST_QUARK (DURATION), GST_TYPE_CLOCK_TIME, duration, NULL));
586 * gst_event_parse_gap:
587 * @event: a #GstEvent of type #GST_EVENT_GAP
588 * @timestamp: (out) (allow-none): location where to store the
589 * start time (pts) of the gap, or %NULL
590 * @duration: (out) (allow-none): location where to store the duration of
593 * Extract timestamp and duration from a new GAP event.
596 gst_event_parse_gap (GstEvent * event, GstClockTime * timestamp,
597 GstClockTime * duration)
599 GstStructure *structure;
601 g_return_if_fail (GST_IS_EVENT (event));
602 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_GAP);
604 structure = GST_EVENT_STRUCTURE (event);
605 gst_structure_id_get (structure,
606 GST_QUARK (TIMESTAMP), GST_TYPE_CLOCK_TIME, timestamp,
607 GST_QUARK (DURATION), GST_TYPE_CLOCK_TIME, duration, NULL);
611 * gst_event_new_caps:
612 * @caps: (transfer none): a #GstCaps
614 * Create a new CAPS event for @caps. The caps event can only travel downstream
615 * synchronized with the buffer flow and contains the format of the buffers
616 * that will follow after the event.
618 * Returns: (transfer full): the new CAPS event.
621 gst_event_new_caps (GstCaps * caps)
625 g_return_val_if_fail (caps != NULL, NULL);
626 g_return_val_if_fail (gst_caps_is_fixed (caps), NULL);
628 GST_CAT_INFO (GST_CAT_EVENT, "creating caps event %" GST_PTR_FORMAT, caps);
630 event = gst_event_new_custom (GST_EVENT_CAPS,
631 gst_structure_new_id (GST_QUARK (EVENT_CAPS),
632 GST_QUARK (CAPS), GST_TYPE_CAPS, caps, NULL));
638 * gst_event_parse_caps:
639 * @event: The event to parse
640 * @caps: (out) (transfer none): A pointer to the caps
642 * Get the caps from @event. The caps remains valid as long as @event remains
646 gst_event_parse_caps (GstEvent * event, GstCaps ** caps)
648 GstStructure *structure;
650 g_return_if_fail (GST_IS_EVENT (event));
651 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_CAPS);
653 structure = GST_EVENT_STRUCTURE (event);
656 g_value_get_boxed (gst_structure_id_get_value (structure,
661 * gst_event_new_segment:
662 * @segment: (transfer none): a #GstSegment
664 * Create a new SEGMENT event for @segment. The segment event can only travel
665 * downstream synchronized with the buffer flow and contains timing information
666 * and playback properties for the buffers that will follow.
668 * The newsegment event marks the range of buffers to be processed. All
669 * data not within the segment range is not to be processed. This can be
670 * used intelligently by plugins to apply more efficient methods of skipping
671 * unneeded data. The valid range is expressed with the @start and @stop
674 * The time value of the segment is used in conjunction with the start
675 * value to convert the buffer timestamps into the stream time. This is
676 * usually done in sinks to report the current stream_time.
677 * @time represents the stream_time of a buffer carrying a timestamp of
678 * @start. @time cannot be -1.
680 * @start cannot be -1, @stop can be -1. If there
681 * is a valid @stop given, it must be greater or equal the @start, including
682 * when the indicated playback @rate is < 0.
684 * The @applied_rate value provides information about any rate adjustment that
685 * has already been made to the timestamps and content on the buffers of the
686 * stream. (@rate * @applied_rate) should always equal the rate that has been
687 * requested for playback. For example, if an element has an input segment
688 * with intended playback @rate of 2.0 and applied_rate of 1.0, it can adjust
689 * incoming timestamps and buffer content by half and output a newsegment event
690 * with @rate of 1.0 and @applied_rate of 2.0
692 * After a newsegment event, the buffer stream time is calculated with:
694 * time + (TIMESTAMP(buf) - start) * ABS (rate * applied_rate)
696 * Returns: (transfer full): the new SEGMENT event.
699 gst_event_new_segment (const GstSegment * segment)
703 g_return_val_if_fail (segment != NULL, NULL);
704 g_return_val_if_fail (segment->rate != 0.0, NULL);
705 g_return_val_if_fail (segment->applied_rate != 0.0, NULL);
706 g_return_val_if_fail (segment->format != GST_FORMAT_UNDEFINED, NULL);
708 GST_CAT_INFO (GST_CAT_EVENT, "creating segment event %" GST_SEGMENT_FORMAT,
711 event = gst_event_new_custom (GST_EVENT_SEGMENT,
712 gst_structure_new_id (GST_QUARK (EVENT_SEGMENT),
713 GST_QUARK (SEGMENT), GST_TYPE_SEGMENT, segment, NULL));
719 * gst_event_parse_segment:
720 * @event: The event to parse
721 * @segment: (out) (transfer none): a pointer to a #GstSegment
723 * Parses a segment @event and stores the result in the given @segment location.
724 * @segment remains valid only until the @event is freed. Don't modify the segment
725 * and make a copy if you want to modify it or store it for later use.
728 gst_event_parse_segment (GstEvent * event, const GstSegment ** segment)
730 GstStructure *structure;
732 g_return_if_fail (GST_IS_EVENT (event));
733 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_SEGMENT);
736 structure = GST_EVENT_STRUCTURE (event);
737 *segment = g_value_get_boxed (gst_structure_id_get_value (structure,
738 GST_QUARK (SEGMENT)));
743 * gst_event_copy_segment:
744 * @event: The event to parse
745 * @segment: a pointer to a #GstSegment
747 * Parses a segment @event and copies the #GstSegment into the location
751 gst_event_copy_segment (GstEvent * event, GstSegment * segment)
753 const GstSegment *src;
755 g_return_if_fail (GST_IS_EVENT (event));
756 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_SEGMENT);
759 gst_event_parse_segment (event, &src);
760 gst_segment_copy_into (src, segment);
766 * @taglist: (transfer full): metadata list. The event will take ownership
769 * Generates a metadata tag event from the given @taglist.
771 * The scope of the taglist specifies if the taglist applies to the
772 * complete medium or only to this specific stream. As the tag event
773 * is a sticky event, elements should merge tags received from
774 * upstream with a given scope with their own tags with the same
775 * scope and create a new tag event from it.
777 * Returns: (transfer full): a new #GstEvent
780 gst_event_new_tag (GstTagList * taglist)
783 GValue val = G_VALUE_INIT;
784 const gchar *names[] = { "GstTagList-stream", "GstTagList-global" };
786 g_return_val_if_fail (taglist != NULL, NULL);
788 s = gst_structure_new_empty (names[gst_tag_list_get_scope (taglist)]);
789 g_value_init (&val, GST_TYPE_TAG_LIST);
790 g_value_take_boxed (&val, taglist);
791 gst_structure_id_take_value (s, GST_QUARK (TAGLIST), &val);
792 return gst_event_new_custom (GST_EVENT_TAG, s);
796 * gst_event_parse_tag:
797 * @event: a tag event
798 * @taglist: (out) (transfer none): pointer to metadata list
800 * Parses a tag @event and stores the results in the given @taglist location.
801 * No reference to the taglist will be returned, it remains valid only until
802 * the @event is freed. Don't modify or free the taglist, make a copy if you
803 * want to modify it or store it for later use.
806 gst_event_parse_tag (GstEvent * event, GstTagList ** taglist)
810 g_return_if_fail (GST_IS_EVENT (event));
811 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_TAG);
813 val = gst_structure_id_get_value (GST_EVENT_STRUCTURE (event),
814 GST_QUARK (TAGLIST));
817 *taglist = (GstTagList *) g_value_get_boxed (val);
820 /* buffersize event */
822 * gst_event_new_buffer_size:
823 * @format: buffer format
824 * @minsize: minimum buffer size
825 * @maxsize: maximum buffer size
826 * @async: thread behavior
828 * Create a new buffersize event. The event is sent downstream and notifies
829 * elements that they should provide a buffer of the specified dimensions.
831 * When the @async flag is set, a thread boundary is preferred.
833 * Returns: (transfer full): a new #GstEvent
836 gst_event_new_buffer_size (GstFormat format, gint64 minsize,
837 gint64 maxsize, gboolean async)
840 GstStructure *structure;
842 GST_CAT_INFO (GST_CAT_EVENT,
843 "creating buffersize format %s, minsize %" G_GINT64_FORMAT
844 ", maxsize %" G_GINT64_FORMAT ", async %d", gst_format_get_name (format),
845 minsize, maxsize, async);
847 structure = gst_structure_new_id (GST_QUARK (EVENT_BUFFER_SIZE),
848 GST_QUARK (FORMAT), GST_TYPE_FORMAT, format,
849 GST_QUARK (MINSIZE), G_TYPE_INT64, minsize,
850 GST_QUARK (MAXSIZE), G_TYPE_INT64, maxsize,
851 GST_QUARK (ASYNC), G_TYPE_BOOLEAN, async, NULL);
852 event = gst_event_new_custom (GST_EVENT_BUFFERSIZE, structure);
858 * gst_event_parse_buffer_size:
859 * @event: The event to query
860 * @format: (out): A pointer to store the format in
861 * @minsize: (out): A pointer to store the minsize in
862 * @maxsize: (out): A pointer to store the maxsize in
863 * @async: (out): A pointer to store the async-flag in
865 * Get the format, minsize, maxsize and async-flag in the buffersize event.
868 gst_event_parse_buffer_size (GstEvent * event, GstFormat * format,
869 gint64 * minsize, gint64 * maxsize, gboolean * async)
871 const GstStructure *structure;
873 g_return_if_fail (GST_IS_EVENT (event));
874 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_BUFFERSIZE);
876 structure = GST_EVENT_STRUCTURE (event);
878 *format = (GstFormat)
879 g_value_get_enum (gst_structure_id_get_value (structure,
880 GST_QUARK (FORMAT)));
883 g_value_get_int64 (gst_structure_id_get_value (structure,
884 GST_QUARK (MINSIZE)));
887 g_value_get_int64 (gst_structure_id_get_value (structure,
888 GST_QUARK (MAXSIZE)));
891 g_value_get_boolean (gst_structure_id_get_value (structure,
897 * @type: the QoS type
898 * @proportion: the proportion of the qos message
899 * @diff: The time difference of the last Clock sync
900 * @timestamp: The timestamp of the buffer
902 * Allocate a new qos event with the given values.
903 * The QOS event is generated in an element that wants an upstream
904 * element to either reduce or increase its rate because of
905 * high/low CPU load or other resource usage such as network performance or
906 * throttling. Typically sinks generate these events for each buffer
909 * @type indicates the reason for the QoS event. #GST_QOS_TYPE_OVERFLOW is
910 * used when a buffer arrived in time or when the sink cannot keep up with
911 * the upstream datarate. #GST_QOS_TYPE_UNDERFLOW is when the sink is not
912 * receiving buffers fast enough and thus has to drop late buffers.
913 * #GST_QOS_TYPE_THROTTLE is used when the datarate is artificially limited
914 * by the application, for example to reduce power consumption.
916 * @proportion indicates the real-time performance of the streaming in the
917 * element that generated the QoS event (usually the sink). The value is
918 * generally computed based on more long term statistics about the streams
919 * timestamps compared to the clock.
920 * A value < 1.0 indicates that the upstream element is producing data faster
921 * than real-time. A value > 1.0 indicates that the upstream element is not
922 * producing data fast enough. 1.0 is the ideal @proportion value. The
923 * proportion value can safely be used to lower or increase the quality of
926 * @diff is the difference against the clock in running time of the last
927 * buffer that caused the element to generate the QOS event. A negative value
928 * means that the buffer with @timestamp arrived in time. A positive value
929 * indicates how late the buffer with @timestamp was. When throttling is
930 * enabled, @diff will be set to the requested throttling interval.
932 * @timestamp is the timestamp of the last buffer that cause the element
933 * to generate the QOS event. It is expressed in running time and thus an ever
936 * The upstream element can use the @diff and @timestamp values to decide
937 * whether to process more buffers. For possitive @diff, all buffers with
938 * timestamp <= @timestamp + @diff will certainly arrive late in the sink
939 * as well. A (negative) @diff value so that @timestamp + @diff would yield a
940 * result smaller than 0 is not allowed.
942 * The application can use general event probes to intercept the QoS
943 * event and implement custom application specific QoS handling.
945 * Returns: (transfer full): a new QOS event.
948 gst_event_new_qos (GstQOSType type, gdouble proportion,
949 GstClockTimeDiff diff, GstClockTime timestamp)
952 GstStructure *structure;
954 /* diff must be positive or timestamp + diff must be positive */
955 g_return_val_if_fail (diff >= 0 || -diff <= timestamp, NULL);
957 GST_CAT_LOG (GST_CAT_EVENT,
958 "creating qos type %d, proportion %lf, diff %" G_GINT64_FORMAT
959 ", timestamp %" GST_TIME_FORMAT, type, proportion,
960 diff, GST_TIME_ARGS (timestamp));
962 structure = gst_structure_new_id (GST_QUARK (EVENT_QOS),
963 GST_QUARK (TYPE), GST_TYPE_QOS_TYPE, type,
964 GST_QUARK (PROPORTION), G_TYPE_DOUBLE, proportion,
965 GST_QUARK (DIFF), G_TYPE_INT64, diff,
966 GST_QUARK (TIMESTAMP), G_TYPE_UINT64, timestamp, NULL);
967 event = gst_event_new_custom (GST_EVENT_QOS, structure);
973 * gst_event_parse_qos:
974 * @event: The event to query
975 * @type: (out): A pointer to store the QoS type in
976 * @proportion: (out): A pointer to store the proportion in
977 * @diff: (out): A pointer to store the diff in
978 * @timestamp: (out): A pointer to store the timestamp in
980 * Get the type, proportion, diff and timestamp in the qos event. See
981 * gst_event_new_qos() for more information about the different QoS values.
984 gst_event_parse_qos (GstEvent * event, GstQOSType * type,
985 gdouble * proportion, GstClockTimeDiff * diff, GstClockTime * timestamp)
987 const GstStructure *structure;
989 g_return_if_fail (GST_IS_EVENT (event));
990 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_QOS);
992 structure = GST_EVENT_STRUCTURE (event);
995 g_value_get_enum (gst_structure_id_get_value (structure,
999 g_value_get_double (gst_structure_id_get_value (structure,
1000 GST_QUARK (PROPORTION)));
1003 g_value_get_int64 (gst_structure_id_get_value (structure,
1007 g_value_get_uint64 (gst_structure_id_get_value (structure,
1008 GST_QUARK (TIMESTAMP)));
1012 * gst_event_new_seek:
1013 * @rate: The new playback rate
1014 * @format: The format of the seek values
1015 * @flags: The optional seek flags
1016 * @start_type: The type and flags for the new start position
1017 * @start: The value of the new start position
1018 * @stop_type: The type and flags for the new stop position
1019 * @stop: The value of the new stop position
1021 * Allocate a new seek event with the given parameters.
1023 * The seek event configures playback of the pipeline between @start to @stop
1024 * at the speed given in @rate, also called a playback segment.
1025 * The @start and @stop values are expressed in @format.
1027 * A @rate of 1.0 means normal playback rate, 2.0 means double speed.
1028 * Negatives values means backwards playback. A value of 0.0 for the
1029 * rate is not allowed and should be accomplished instead by PAUSING the
1032 * A pipeline has a default playback segment configured with a start
1033 * position of 0, a stop position of -1 and a rate of 1.0. The currently
1034 * configured playback segment can be queried with #GST_QUERY_SEGMENT.
1036 * @start_type and @stop_type specify how to adjust the currently configured
1037 * start and stop fields in playback segment. Adjustments can be made relative
1038 * or absolute to the last configured values. A type of #GST_SEEK_TYPE_NONE
1039 * means that the position should not be updated.
1041 * When the rate is positive and @start has been updated, playback will start
1042 * from the newly configured start position.
1044 * For negative rates, playback will start from the newly configured stop
1045 * position (if any). If the stop position is updated, it must be different from
1046 * -1 (#GST_CLOCK_TIME_NONE) for negative rates.
1048 * It is not possible to seek relative to the current playback position, to do
1049 * this, PAUSE the pipeline, query the current playback position with
1050 * #GST_QUERY_POSITION and update the playback segment current position with a
1051 * #GST_SEEK_TYPE_SET to the desired position.
1053 * Returns: (transfer full): a new seek event.
1056 gst_event_new_seek (gdouble rate, GstFormat format, GstSeekFlags flags,
1057 GstSeekType start_type, gint64 start, GstSeekType stop_type, gint64 stop)
1060 GstStructure *structure;
1062 g_return_val_if_fail (rate != 0.0, NULL);
1064 if (format == GST_FORMAT_TIME) {
1065 GST_CAT_INFO (GST_CAT_EVENT,
1066 "creating seek rate %lf, format TIME, flags %d, "
1067 "start_type %d, start %" GST_TIME_FORMAT ", "
1068 "stop_type %d, stop %" GST_TIME_FORMAT,
1069 rate, flags, start_type, GST_TIME_ARGS (start),
1070 stop_type, GST_TIME_ARGS (stop));
1072 GST_CAT_INFO (GST_CAT_EVENT,
1073 "creating seek rate %lf, format %s, flags %d, "
1074 "start_type %d, start %" G_GINT64_FORMAT ", "
1075 "stop_type %d, stop %" G_GINT64_FORMAT,
1076 rate, gst_format_get_name (format), flags, start_type, start, stop_type,
1080 structure = gst_structure_new_id (GST_QUARK (EVENT_SEEK),
1081 GST_QUARK (RATE), G_TYPE_DOUBLE, rate,
1082 GST_QUARK (FORMAT), GST_TYPE_FORMAT, format,
1083 GST_QUARK (FLAGS), GST_TYPE_SEEK_FLAGS, flags,
1084 GST_QUARK (CUR_TYPE), GST_TYPE_SEEK_TYPE, start_type,
1085 GST_QUARK (CUR), G_TYPE_INT64, start,
1086 GST_QUARK (STOP_TYPE), GST_TYPE_SEEK_TYPE, stop_type,
1087 GST_QUARK (STOP), G_TYPE_INT64, stop, NULL);
1088 event = gst_event_new_custom (GST_EVENT_SEEK, structure);
1094 * gst_event_parse_seek:
1095 * @event: a seek event
1096 * @rate: (out): result location for the rate
1097 * @format: (out): result location for the stream format
1098 * @flags: (out): result location for the #GstSeekFlags
1099 * @start_type: (out): result location for the #GstSeekType of the start position
1100 * @start: (out): result location for the start postion expressed in @format
1101 * @stop_type: (out): result location for the #GstSeekType of the stop position
1102 * @stop: (out): result location for the stop postion expressed in @format
1104 * Parses a seek @event and stores the results in the given result locations.
1107 gst_event_parse_seek (GstEvent * event, gdouble * rate,
1108 GstFormat * format, GstSeekFlags * flags, GstSeekType * start_type,
1109 gint64 * start, GstSeekType * stop_type, gint64 * stop)
1111 const GstStructure *structure;
1113 g_return_if_fail (GST_IS_EVENT (event));
1114 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_SEEK);
1116 structure = GST_EVENT_STRUCTURE (event);
1119 g_value_get_double (gst_structure_id_get_value (structure,
1122 *format = (GstFormat)
1123 g_value_get_enum (gst_structure_id_get_value (structure,
1124 GST_QUARK (FORMAT)));
1126 *flags = (GstSeekFlags)
1127 g_value_get_flags (gst_structure_id_get_value (structure,
1128 GST_QUARK (FLAGS)));
1130 *start_type = (GstSeekType)
1131 g_value_get_enum (gst_structure_id_get_value (structure,
1132 GST_QUARK (CUR_TYPE)));
1135 g_value_get_int64 (gst_structure_id_get_value (structure,
1138 *stop_type = (GstSeekType)
1139 g_value_get_enum (gst_structure_id_get_value (structure,
1140 GST_QUARK (STOP_TYPE)));
1143 g_value_get_int64 (gst_structure_id_get_value (structure,
1148 * gst_event_new_navigation:
1149 * @structure: (transfer full): description of the event. The event will take
1150 * ownership of the structure.
1152 * Create a new navigation event from the given description.
1154 * Returns: (transfer full): a new #GstEvent
1157 gst_event_new_navigation (GstStructure * structure)
1159 g_return_val_if_fail (structure != NULL, NULL);
1161 return gst_event_new_custom (GST_EVENT_NAVIGATION, structure);
1165 * gst_event_new_latency:
1166 * @latency: the new latency value
1168 * Create a new latency event. The event is sent upstream from the sinks and
1169 * notifies elements that they should add an additional @latency to the
1170 * running time before synchronising against the clock.
1172 * The latency is mostly used in live sinks and is always expressed in
1175 * Returns: (transfer full): a new #GstEvent
1178 gst_event_new_latency (GstClockTime latency)
1181 GstStructure *structure;
1183 GST_CAT_INFO (GST_CAT_EVENT,
1184 "creating latency event %" GST_TIME_FORMAT, GST_TIME_ARGS (latency));
1186 structure = gst_structure_new_id (GST_QUARK (EVENT_LATENCY),
1187 GST_QUARK (LATENCY), G_TYPE_UINT64, latency, NULL);
1188 event = gst_event_new_custom (GST_EVENT_LATENCY, structure);
1194 * gst_event_parse_latency:
1195 * @event: The event to query
1196 * @latency: (out): A pointer to store the latency in.
1198 * Get the latency in the latency event.
1201 gst_event_parse_latency (GstEvent * event, GstClockTime * latency)
1203 g_return_if_fail (GST_IS_EVENT (event));
1204 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_LATENCY);
1208 g_value_get_uint64 (gst_structure_id_get_value (GST_EVENT_STRUCTURE
1209 (event), GST_QUARK (LATENCY)));
1213 * gst_event_new_step:
1214 * @format: the format of @amount
1215 * @amount: the amount of data to step
1216 * @rate: the step rate
1217 * @flush: flushing steps
1218 * @intermediate: intermediate steps
1220 * Create a new step event. The purpose of the step event is to instruct a sink
1221 * to skip @amount (expressed in @format) of media. It can be used to implement
1222 * stepping through the video frame by frame or for doing fast trick modes.
1224 * A rate of <= 0.0 is not allowed. Pause the pipeline, for the effect of rate
1225 * = 0.0 or first reverse the direction of playback using a seek event to get
1226 * the same effect as rate < 0.0.
1228 * The @flush flag will clear any pending data in the pipeline before starting
1229 * the step operation.
1231 * The @intermediate flag instructs the pipeline that this step operation is
1232 * part of a larger step operation.
1234 * Returns: (transfer full): a new #GstEvent
1237 gst_event_new_step (GstFormat format, guint64 amount, gdouble rate,
1238 gboolean flush, gboolean intermediate)
1241 GstStructure *structure;
1243 g_return_val_if_fail (rate > 0.0, NULL);
1245 GST_CAT_INFO (GST_CAT_EVENT, "creating step event");
1247 structure = gst_structure_new_id (GST_QUARK (EVENT_STEP),
1248 GST_QUARK (FORMAT), GST_TYPE_FORMAT, format,
1249 GST_QUARK (AMOUNT), G_TYPE_UINT64, amount,
1250 GST_QUARK (RATE), G_TYPE_DOUBLE, rate,
1251 GST_QUARK (FLUSH), G_TYPE_BOOLEAN, flush,
1252 GST_QUARK (INTERMEDIATE), G_TYPE_BOOLEAN, intermediate, NULL);
1253 event = gst_event_new_custom (GST_EVENT_STEP, structure);
1259 * gst_event_parse_step:
1260 * @event: The event to query
1261 * @format: (out) (allow-none): a pointer to store the format in
1262 * @amount: (out) (allow-none): a pointer to store the amount in
1263 * @rate: (out) (allow-none): a pointer to store the rate in
1264 * @flush: (out) (allow-none): a pointer to store the flush boolean in
1265 * @intermediate: (out) (allow-none): a pointer to store the intermediate
1268 * Parse the step event.
1271 gst_event_parse_step (GstEvent * event, GstFormat * format, guint64 * amount,
1272 gdouble * rate, gboolean * flush, gboolean * intermediate)
1274 const GstStructure *structure;
1276 g_return_if_fail (GST_IS_EVENT (event));
1277 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STEP);
1279 structure = GST_EVENT_STRUCTURE (event);
1282 (GstFormat) g_value_get_enum (gst_structure_id_get_value (structure,
1283 GST_QUARK (FORMAT)));
1285 *amount = g_value_get_uint64 (gst_structure_id_get_value (structure,
1286 GST_QUARK (AMOUNT)));
1288 *rate = g_value_get_double (gst_structure_id_get_value (structure,
1291 *flush = g_value_get_boolean (gst_structure_id_get_value (structure,
1292 GST_QUARK (FLUSH)));
1294 *intermediate = g_value_get_boolean (gst_structure_id_get_value (structure,
1295 GST_QUARK (INTERMEDIATE)));
1299 * gst_event_new_reconfigure:
1301 * Create a new reconfigure event. The purpose of the reconfingure event is
1302 * to travel upstream and make elements renegotiate their caps or reconfigure
1303 * their buffer pools. This is useful when changing properties on elements
1304 * or changing the topology of the pipeline.
1306 * Returns: (transfer full): a new #GstEvent
1309 gst_event_new_reconfigure (void)
1313 GST_CAT_INFO (GST_CAT_EVENT, "creating reconfigure event");
1315 event = gst_event_new_custom (GST_EVENT_RECONFIGURE, NULL);
1321 * gst_event_new_sink_message:
1322 * @name: a name for the event
1323 * @msg: (transfer none): the #GstMessage to be posted
1325 * Create a new sink-message event. The purpose of the sink-message event is
1326 * to instruct a sink to post the message contained in the event synchronized
1329 * @name is used to store multiple sticky events on one pad.
1331 * Returns: (transfer full): a new #GstEvent
1333 /* FIXME 0.11: take ownership of msg for consistency? */
1335 gst_event_new_sink_message (const gchar * name, GstMessage * msg)
1338 GstStructure *structure;
1340 g_return_val_if_fail (msg != NULL, NULL);
1342 GST_CAT_INFO (GST_CAT_EVENT, "creating sink-message event");
1344 structure = gst_structure_new_id (g_quark_from_string (name),
1345 GST_QUARK (MESSAGE), GST_TYPE_MESSAGE, msg, NULL);
1346 event = gst_event_new_custom (GST_EVENT_SINK_MESSAGE, structure);
1352 * gst_event_parse_sink_message:
1353 * @event: The event to query
1354 * @msg: (out) (transfer full): a pointer to store the #GstMessage in.
1356 * Parse the sink-message event. Unref @msg after usage.
1359 gst_event_parse_sink_message (GstEvent * event, GstMessage ** msg)
1361 const GstStructure *structure;
1363 g_return_if_fail (GST_IS_EVENT (event));
1364 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_SINK_MESSAGE);
1366 structure = GST_EVENT_STRUCTURE (event);
1369 GST_MESSAGE (g_value_dup_boxed (gst_structure_id_get_value
1370 (structure, GST_QUARK (MESSAGE))));
1374 * gst_event_new_stream_start:
1375 * @stream_id: Identifier for this stream
1377 * Create a new STREAM_START event. The stream start event can only
1378 * travel downstream synchronized with the buffer flow. It is expected
1379 * to be the first event that is sent for a new stream.
1381 * Source elements, demuxers and other elements that create new streams
1382 * are supposed to send this event as the first event of a new stream. It
1383 * should not be send after a flushing seek or in similar situations
1384 * and is used to mark the beginning of a new logical stream. Elements
1385 * combining multiple streams must ensure that this event is only forwarded
1386 * downstream once and not for every single input stream.
1388 * The @stream_id should be a unique string that consists of the upstream
1389 * stream-id, / as separator and a unique stream-id for this specific
1390 * stream. A new stream-id should only be created for a stream if the upstream
1391 * stream is split into (potentially) multiple new streams, e.g. in a demuxer,
1392 * but not for every single element in the pipeline.
1393 * gst_pad_create_stream_id() or gst_pad_create_stream_id_printf() can be
1394 * used to create a stream-id.
1396 * Returns: (transfer full): the new STREAM_START event.
1399 gst_event_new_stream_start (const gchar * stream_id)
1403 g_return_val_if_fail (stream_id != NULL, NULL);
1405 s = gst_structure_new_id (GST_QUARK (EVENT_STREAM_START),
1406 GST_QUARK (STREAM_ID), G_TYPE_STRING, stream_id,
1407 GST_QUARK (FLAGS), GST_TYPE_STREAM_FLAGS, GST_STREAM_FLAG_NONE, NULL);
1409 return gst_event_new_custom (GST_EVENT_STREAM_START, s);
1413 * gst_event_parse_stream_start:
1414 * @event: a stream-start event.
1415 * @stream_id: (out) (transfer none): pointer to store the stream-id
1417 * Parse a stream-id @event and store the result in the given @stream_id
1418 * location. The string stored in @stream_id must not be modified and will
1419 * remain valid only until @event gets freed. Make a copy if you want to
1420 * modify it or store it for later use.
1423 gst_event_parse_stream_start (GstEvent * event, const gchar ** stream_id)
1425 const GstStructure *structure;
1428 g_return_if_fail (event != NULL);
1429 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STREAM_START);
1431 structure = gst_event_get_structure (event);
1432 val = gst_structure_id_get_value (structure, GST_QUARK (STREAM_ID));
1435 *stream_id = g_value_get_string (val);
1439 * gst_event_set_stream_flags:
1440 * @event: a stream-start event
1441 * @flags: the stream flags to set
1446 gst_event_set_stream_flags (GstEvent * event, GstStreamFlags flags)
1448 g_return_if_fail (event != NULL);
1449 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STREAM_START);
1450 g_return_if_fail (gst_event_is_writable (event));
1452 gst_structure_id_set (GST_EVENT_STRUCTURE (event),
1453 GST_QUARK (FLAGS), GST_TYPE_STREAM_FLAGS, flags, NULL);
1457 * gst_event_parse_stream_flags:
1458 * @event: a stream-start event
1459 * @flags: (out): address of variable where to store the stream flags
1464 gst_event_parse_stream_flags (GstEvent * event, GstStreamFlags * flags)
1466 g_return_if_fail (event != NULL);
1467 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STREAM_START);
1470 gst_structure_id_get (GST_EVENT_STRUCTURE (event),
1471 GST_QUARK (FLAGS), GST_TYPE_STREAM_FLAGS, flags, NULL);
1476 * gst_event_set_group_id:
1477 * @event: a stream-start event
1478 * @group_id: the group id to set
1480 * All streams that have the same group id are supposed to be played
1481 * together, i.e. all streams inside a container file should have the
1482 * same group id but different stream ids. The group id should change
1483 * each time the stream is started, resulting in different group ids
1484 * each time a file is played for example.
1486 * Use gst_util_group_id_next() to get a new group id.
1491 gst_event_set_group_id (GstEvent * event, guint group_id)
1493 g_return_if_fail (event != NULL);
1494 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STREAM_START);
1495 g_return_if_fail (gst_event_is_writable (event));
1497 gst_structure_id_set (GST_EVENT_STRUCTURE (event),
1498 GST_QUARK (GROUP_ID), G_TYPE_UINT, group_id, NULL);
1502 * gst_event_parse_group_id:
1503 * @event: a stream-start event
1504 * @group_id: (out): address of variable where to store the group id
1506 * Returns: %TRUE if a group id was set on the event and could be parsed,
1512 gst_event_parse_group_id (GstEvent * event, guint * group_id)
1514 g_return_val_if_fail (event != NULL, FALSE);
1515 g_return_val_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STREAM_START,
1519 return gst_structure_id_get (GST_EVENT_STRUCTURE (event),
1520 GST_QUARK (GROUP_ID), G_TYPE_UINT, group_id, NULL);
1527 * gst_event_new_toc:
1528 * @toc: (transfer none): #GstToc structure.
1529 * @updated: whether @toc was updated or not.
1531 * Generate a TOC event from the given @toc. The purpose of the TOC event is to
1532 * inform elements that some kind of the TOC was found.
1534 * Returns: (transfer full): a new #GstEvent.
1537 gst_event_new_toc (GstToc * toc, gboolean updated)
1539 GstStructure *toc_struct;
1542 g_return_val_if_fail (toc != NULL, NULL);
1544 GST_CAT_INFO (GST_CAT_EVENT, "creating toc event");
1546 /* need different structure names so sticky_multi event stuff on pads
1547 * works, i.e. both TOC events are kept around */
1548 if (gst_toc_get_scope (toc) == GST_TOC_SCOPE_GLOBAL)
1549 id = GST_QUARK (EVENT_TOC_GLOBAL);
1551 id = GST_QUARK (EVENT_TOC_CURRENT);
1553 toc_struct = gst_structure_new_id (id,
1554 GST_QUARK (TOC), GST_TYPE_TOC, toc,
1555 GST_QUARK (UPDATED), G_TYPE_BOOLEAN, updated, NULL);
1557 return gst_event_new_custom (GST_EVENT_TOC, toc_struct);
1561 * gst_event_parse_toc:
1562 * @event: a TOC event.
1563 * @toc: (out) (transfer full): pointer to #GstToc structure.
1564 * @updated: (out): pointer to store TOC updated flag.
1566 * Parse a TOC @event and store the results in the given @toc and @updated locations.
1569 gst_event_parse_toc (GstEvent * event, GstToc ** toc, gboolean * updated)
1571 const GstStructure *structure;
1573 g_return_if_fail (event != NULL);
1574 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_TOC);
1575 g_return_if_fail (toc != NULL);
1577 structure = gst_event_get_structure (event);
1579 gst_structure_id_get (structure,
1580 GST_QUARK (TOC), GST_TYPE_TOC, toc,
1581 GST_QUARK (UPDATED), G_TYPE_BOOLEAN, updated, NULL);
1585 * gst_event_new_toc_select:
1586 * @uid: UID in the TOC to start playback from.
1588 * Generate a TOC select event with the given @uid. The purpose of the
1589 * TOC select event is to start playback based on the TOC's entry with the
1592 * Returns: a new #GstEvent.
1595 gst_event_new_toc_select (const gchar * uid)
1597 GstStructure *structure;
1599 g_return_val_if_fail (uid != NULL, NULL);
1601 GST_CAT_INFO (GST_CAT_EVENT, "creating toc select event for UID: %s", uid);
1603 structure = gst_structure_new_id (GST_QUARK (EVENT_TOC_SELECT),
1604 GST_QUARK (UID), G_TYPE_STRING, uid, NULL);
1606 return gst_event_new_custom (GST_EVENT_TOC_SELECT, structure);
1610 * gst_event_parse_toc_select:
1611 * @event: a TOC select event.
1612 * @uid: (out): storage for the selection UID.
1614 * Parse a TOC select @event and store the results in the given @uid location.
1617 gst_event_parse_toc_select (GstEvent * event, gchar ** uid)
1619 const GstStructure *structure;
1622 g_return_if_fail (event != NULL);
1623 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_TOC_SELECT);
1625 structure = gst_event_get_structure (event);
1626 val = gst_structure_id_get_value (structure, GST_QUARK (UID));
1629 *uid = g_strdup (g_value_get_string (val));
1634 * gst_event_new_segment_done:
1635 * @format: The format of the position being done
1636 * @position: The position of the segment being done
1638 * Create a new segment-done event. This event is sent by elements that
1639 * finish playback of a segment as a result of a segment seek.
1641 * Returns: (transfer full): a new #GstEvent
1644 gst_event_new_segment_done (GstFormat format, gint64 position)
1647 GstStructure *structure;
1649 GST_CAT_INFO (GST_CAT_EVENT, "creating segment-done event");
1651 structure = gst_structure_new_id (GST_QUARK (EVENT_SEGMENT_DONE),
1652 GST_QUARK (FORMAT), GST_TYPE_FORMAT, format,
1653 GST_QUARK (POSITION), G_TYPE_INT64, position, NULL);
1655 event = gst_event_new_custom (GST_EVENT_SEGMENT_DONE, structure);
1661 * gst_event_parse_segment_done:
1662 * @event: A valid #GstEvent of type GST_EVENT_SEGMENT_DONE.
1663 * @format: (out) (allow-none): Result location for the format, or NULL
1664 * @position: (out) (allow-none): Result location for the position, or NULL
1666 * Extracts the position and format from the segment done message.
1670 gst_event_parse_segment_done (GstEvent * event, GstFormat * format,
1673 const GstStructure *structure;
1676 g_return_if_fail (event != NULL);
1677 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_SEGMENT_DONE);
1679 structure = gst_event_get_structure (event);
1681 val = gst_structure_id_get_value (structure, GST_QUARK (FORMAT));
1683 *format = g_value_get_enum (val);
1685 val = gst_structure_id_get_value (structure, GST_QUARK (POSITION));
1686 if (position != NULL)
1687 *position = g_value_get_int64 (val);