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.
58 * // construct a seek event to play the media from second 2 to 5, flush
59 * // the pipeline to decrease latency.
60 * event = gst_event_new_seek (1.0,
62 * GST_SEEK_FLAG_FLUSH,
63 * GST_SEEK_TYPE_SET, 2 * GST_SECOND,
64 * GST_SEEK_TYPE_SET, 5 * GST_SECOND);
66 * result = gst_element_send_event (pipeline, event);
68 * g_warning ("seek failed");
72 * Last reviewed on 2012-03-28 (0.11.3)
76 #include "gst_private.h"
77 #include <string.h> /* memcpy */
81 #include "gstenumtypes.h"
86 GType _gst_event_type = 0;
92 GstStructure *structure;
93 gint64 running_time_offset;
96 #define GST_EVENT_STRUCTURE(e) (((GstEventImpl *)(e))->structure)
105 static GstEventQuarks event_quarks[] = {
106 {GST_EVENT_UNKNOWN, "unknown", 0},
107 {GST_EVENT_FLUSH_START, "flush-start", 0},
108 {GST_EVENT_FLUSH_STOP, "flush-stop", 0},
109 {GST_EVENT_STREAM_START, "stream-start", 0},
110 {GST_EVENT_CAPS, "caps", 0},
111 {GST_EVENT_SEGMENT, "segment", 0},
112 {GST_EVENT_TAG, "tag", 0},
113 {GST_EVENT_TOC, "toc", 0},
114 {GST_EVENT_BUFFERSIZE, "buffersize", 0},
115 {GST_EVENT_SINK_MESSAGE, "sink-message", 0},
116 {GST_EVENT_EOS, "eos", 0},
117 {GST_EVENT_SEGMENT_DONE, "segment-done", 0},
118 {GST_EVENT_GAP, "gap", 0},
119 {GST_EVENT_QOS, "qos", 0},
120 {GST_EVENT_SEEK, "seek", 0},
121 {GST_EVENT_NAVIGATION, "navigation", 0},
122 {GST_EVENT_LATENCY, "latency", 0},
123 {GST_EVENT_STEP, "step", 0},
124 {GST_EVENT_RECONFIGURE, "reconfigure", 0},
125 {GST_EVENT_TOC_SELECT, "toc-select", 0},
126 {GST_EVENT_CUSTOM_UPSTREAM, "custom-upstream", 0},
127 {GST_EVENT_CUSTOM_DOWNSTREAM, "custom-downstream", 0},
128 {GST_EVENT_CUSTOM_DOWNSTREAM_OOB, "custom-downstream-oob", 0},
129 {GST_EVENT_CUSTOM_DOWNSTREAM_STICKY, "custom-downstream-sticky", 0},
130 {GST_EVENT_CUSTOM_BOTH, "custom-both", 0},
131 {GST_EVENT_CUSTOM_BOTH_OOB, "custom-both-oob", 0},
136 GST_DEFINE_MINI_OBJECT_TYPE (GstEvent, gst_event);
139 _priv_gst_event_initialize (void)
143 _gst_event_type = gst_event_get_type ();
145 g_type_class_ref (gst_seek_flags_get_type ());
146 g_type_class_ref (gst_seek_type_get_type ());
148 for (i = 0; event_quarks[i].name; i++) {
149 event_quarks[i].quark = g_quark_from_static_string (event_quarks[i].name);
154 * gst_event_type_get_name:
155 * @type: the event type
157 * Get a printable name for the given event type. Do not modify or free.
159 * Returns: a reference to the static name of the event.
162 gst_event_type_get_name (GstEventType type)
166 for (i = 0; event_quarks[i].name; i++) {
167 if (type == event_quarks[i].type)
168 return event_quarks[i].name;
174 * gst_event_type_to_quark:
175 * @type: the event type
177 * Get the unique quark for the given event type.
179 * Returns: the quark associated with the event type
182 gst_event_type_to_quark (GstEventType type)
186 for (i = 0; event_quarks[i].name; i++) {
187 if (type == event_quarks[i].type)
188 return event_quarks[i].quark;
194 * gst_event_type_get_flags:
195 * @type: a #GstEventType
197 * Gets the #GstEventTypeFlags associated with @type.
199 * Returns: a #GstEventTypeFlags.
202 gst_event_type_get_flags (GstEventType type)
204 GstEventTypeFlags ret;
206 ret = type & ((1 << GST_EVENT_NUM_SHIFT) - 1);
212 _gst_event_free (GstEvent * event)
216 g_return_if_fail (event != NULL);
217 g_return_if_fail (GST_IS_EVENT (event));
219 GST_CAT_LOG (GST_CAT_EVENT, "freeing event %p type %s", event,
220 GST_EVENT_TYPE_NAME (event));
222 s = GST_EVENT_STRUCTURE (event);
225 gst_structure_set_parent_refcount (s, NULL);
226 gst_structure_free (s);
229 g_slice_free1 (sizeof (GstEventImpl), event);
232 static void gst_event_init (GstEventImpl * event, GstEventType type);
235 _gst_event_copy (GstEvent * event)
240 copy = g_slice_new0 (GstEventImpl);
242 gst_event_init (copy, GST_EVENT_TYPE (event));
244 GST_EVENT_TIMESTAMP (copy) = GST_EVENT_TIMESTAMP (event);
245 GST_EVENT_SEQNUM (copy) = GST_EVENT_SEQNUM (event);
247 s = GST_EVENT_STRUCTURE (event);
249 GST_EVENT_STRUCTURE (copy) = gst_structure_copy (s);
250 gst_structure_set_parent_refcount (GST_EVENT_STRUCTURE (copy),
251 ©->event.mini_object.refcount);
253 GST_EVENT_STRUCTURE (copy) = NULL;
256 ((GstEventImpl *) copy)->running_time_offset =
257 ((GstEventImpl *) event)->running_time_offset;
259 return GST_EVENT_CAST (copy);
263 gst_event_init (GstEventImpl * event, GstEventType type)
265 gst_mini_object_init (GST_MINI_OBJECT_CAST (event), 0, _gst_event_type,
266 (GstMiniObjectCopyFunction) _gst_event_copy, NULL,
267 (GstMiniObjectFreeFunction) _gst_event_free);
269 GST_EVENT_TYPE (event) = type;
270 GST_EVENT_TIMESTAMP (event) = GST_CLOCK_TIME_NONE;
271 GST_EVENT_SEQNUM (event) = gst_util_seqnum_next ();
272 event->running_time_offset = 0;
277 * gst_event_new_custom:
278 * @type: The type of the new event
279 * @structure: (transfer full): the structure for the event. The event will
280 * take ownership of the structure.
282 * Create a new custom-typed event. This can be used for anything not
283 * handled by other event-specific functions to pass an event to another
286 * Make sure to allocate an event type with the #GST_EVENT_MAKE_TYPE macro,
287 * assigning a free number and filling in the correct direction and
288 * serialization flags.
290 * New custom events can also be created by subclassing the event type if
293 * Returns: (transfer full): the new custom event.
296 gst_event_new_custom (GstEventType type, GstStructure * structure)
300 event = g_slice_new0 (GstEventImpl);
302 GST_CAT_DEBUG (GST_CAT_EVENT, "creating new event %p %s %d", event,
303 gst_event_type_get_name (type), type);
306 /* structure must not have a parent */
307 if (!gst_structure_set_parent_refcount (structure,
308 &event->event.mini_object.refcount))
312 gst_event_init (event, type);
314 GST_EVENT_STRUCTURE (event) = structure;
316 return GST_EVENT_CAST (event);
321 g_slice_free1 (sizeof (GstEventImpl), event);
322 g_warning ("structure is already owned by another object");
328 * gst_event_get_structure:
329 * @event: The #GstEvent.
331 * Access the structure of the event.
333 * Returns: The structure of the event. The structure is still
334 * owned by the event, which means that you should not free it and
335 * that the pointer becomes invalid when you free the event.
340 gst_event_get_structure (GstEvent * event)
342 g_return_val_if_fail (GST_IS_EVENT (event), NULL);
344 return GST_EVENT_STRUCTURE (event);
348 * gst_event_writable_structure:
349 * @event: The #GstEvent.
351 * Get a writable version of the structure.
353 * Returns: The structure of the event. The structure is still
354 * owned by the event, which means that you should not free it and
355 * that the pointer becomes invalid when you free the event.
356 * This function checks if @event is writable and will never return NULL.
361 gst_event_writable_structure (GstEvent * event)
363 GstStructure *structure;
365 g_return_val_if_fail (GST_IS_EVENT (event), NULL);
366 g_return_val_if_fail (gst_event_is_writable (event), NULL);
368 structure = GST_EVENT_STRUCTURE (event);
370 if (structure == NULL) {
372 gst_structure_new_id_empty (gst_event_type_to_quark (GST_EVENT_TYPE
374 gst_structure_set_parent_refcount (structure, &event->mini_object.refcount);
375 GST_EVENT_STRUCTURE (event) = structure;
381 * gst_event_has_name:
382 * @event: The #GstEvent.
383 * @name: name to check
385 * Checks if @event has the given @name. This function is usually used to
386 * check the name of a custom event.
388 * Returns: %TRUE if @name matches the name of the event structure.
391 gst_event_has_name (GstEvent * event, const gchar * name)
393 g_return_val_if_fail (GST_IS_EVENT (event), FALSE);
395 if (GST_EVENT_STRUCTURE (event) == NULL)
398 return gst_structure_has_name (GST_EVENT_STRUCTURE (event), name);
402 * gst_event_get_seqnum:
403 * @event: A #GstEvent.
405 * Retrieve the sequence number of a event.
407 * Events have ever-incrementing sequence numbers, which may also be set
408 * explicitly via gst_event_set_seqnum(). Sequence numbers are typically used to
409 * indicate that a event corresponds to some other set of events or messages,
410 * for example an EOS event corresponding to a SEEK event. It is considered good
411 * practice to make this correspondence when possible, though it is not
414 * Note that events and messages share the same sequence number incrementor;
415 * two events or messages will never have the same sequence number unless
416 * that correspondence was made explicitly.
418 * Returns: The event's sequence number.
423 gst_event_get_seqnum (GstEvent * event)
425 g_return_val_if_fail (GST_IS_EVENT (event), -1);
427 return GST_EVENT_SEQNUM (event);
431 * gst_event_set_seqnum:
432 * @event: A #GstEvent.
433 * @seqnum: A sequence number.
435 * Set the sequence number of a event.
437 * This function might be called by the creator of a event to indicate that the
438 * event relates to other events or messages. See gst_event_get_seqnum() for
444 gst_event_set_seqnum (GstEvent * event, guint32 seqnum)
446 g_return_if_fail (GST_IS_EVENT (event));
448 GST_EVENT_SEQNUM (event) = seqnum;
452 * gst_event_get_running_time_offset:
453 * @event: A #GstEvent.
455 * Retrieve the accumulated running time offset of the event.
457 * Events passing through #GstPads that have a running time
458 * offset set via gst_pad_set_offset() will get their offset
459 * adjusted according to the pad's offset.
461 * If the event contains any information that related to the
462 * running time, this information will need to be updated
463 * before usage with this offset.
465 * Returns: The event's running time offset
472 gst_event_get_running_time_offset (GstEvent * event)
474 g_return_val_if_fail (GST_IS_EVENT (event), 0);
476 return ((GstEventImpl *) event)->running_time_offset;
480 * gst_event_set_running_time_offset:
481 * @event: A #GstEvent.
482 * @offset: A the new running time offset
484 * Set the running time offset of a event. See
485 * gst_event_get_running_time_offset() for more information.
492 gst_event_set_running_time_offset (GstEvent * event, gint64 offset)
494 g_return_if_fail (GST_IS_EVENT (event));
496 ((GstEventImpl *) event)->running_time_offset = offset;
500 * gst_event_new_flush_start:
502 * Allocate a new flush start event. The flush start event can be sent
503 * upstream and downstream and travels out-of-bounds with the dataflow.
505 * It marks pads as being flushing and will make them return
506 * #GST_FLOW_FLUSHING when used for data flow with gst_pad_push(),
507 * gst_pad_chain(), gst_pad_get_range() and gst_pad_pull_range().
508 * Any event (except a #GST_EVENT_FLUSH_STOP) received
509 * on a flushing pad will return %FALSE immediately.
511 * Elements should unlock any blocking functions and exit their streaming
512 * functions as fast as possible when this event is received.
514 * This event is typically generated after a seek to flush out all queued data
515 * in the pipeline so that the new media is played as soon as possible.
517 * Returns: (transfer full): a new flush start event.
520 gst_event_new_flush_start (void)
522 return gst_event_new_custom (GST_EVENT_FLUSH_START, NULL);
526 * gst_event_new_flush_stop:
527 * @reset_time: if time should be reset
529 * Allocate a new flush stop event. The flush stop event can be sent
530 * upstream and downstream and travels serialized with the dataflow.
531 * It is typically sent after sending a FLUSH_START event to make the
532 * pads accept data again.
534 * Elements can process this event synchronized with the dataflow since
535 * the preceding FLUSH_START event stopped the dataflow.
537 * This event is typically generated to complete a seek and to resume
540 * Returns: (transfer full): a new flush stop event.
543 gst_event_new_flush_stop (gboolean reset_time)
547 GST_CAT_INFO (GST_CAT_EVENT, "creating flush stop %d", reset_time);
549 event = gst_event_new_custom (GST_EVENT_FLUSH_STOP,
550 gst_structure_new_id (GST_QUARK (EVENT_FLUSH_STOP),
551 GST_QUARK (RESET_TIME), G_TYPE_BOOLEAN, reset_time, NULL));
557 * gst_event_parse_flush_stop:
558 * @event: The event to parse
559 * @reset_time: (out): if time should be reset
561 * Parse the FLUSH_STOP event and retrieve the @reset_time member.
564 gst_event_parse_flush_stop (GstEvent * event, gboolean * reset_time)
566 GstStructure *structure;
568 g_return_if_fail (GST_IS_EVENT (event));
569 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_FLUSH_STOP);
571 structure = GST_EVENT_STRUCTURE (event);
572 if (G_LIKELY (reset_time))
574 g_value_get_boolean (gst_structure_id_get_value (structure,
575 GST_QUARK (RESET_TIME)));
581 * Create a new EOS event. The eos event can only travel downstream
582 * synchronized with the buffer flow. Elements that receive the EOS
583 * event on a pad can return #GST_FLOW_EOS as a #GstFlowReturn
584 * when data after the EOS event arrives.
586 * The EOS event will travel down to the sink elements in the pipeline
587 * which will then post the #GST_MESSAGE_EOS on the bus after they have
588 * finished playing any buffered data.
590 * When all sinks have posted an EOS message, an EOS message is
591 * forwarded to the application.
593 * The EOS event itself will not cause any state transitions of the pipeline.
595 * Returns: (transfer full): the new EOS event.
598 gst_event_new_eos (void)
600 return gst_event_new_custom (GST_EVENT_EOS, NULL);
605 * @timestamp: the start time (pts) of the gap
606 * @duration: the duration of the gap
608 * Create a new GAP event. A gap event can be thought of as conceptually
609 * equivalent to a buffer to signal that there is no data for a certain
610 * amount of time. This is useful to signal a gap to downstream elements
611 * which may wait for data, such as muxers or mixers or overlays, especially
612 * for sparse streams such as subtitle streams.
614 * Returns: (transfer full): the new GAP event.
617 gst_event_new_gap (GstClockTime timestamp, GstClockTime duration)
621 g_return_val_if_fail (GST_CLOCK_TIME_IS_VALID (timestamp), NULL);
623 GST_CAT_TRACE (GST_CAT_EVENT, "creating gap %" GST_TIME_FORMAT " - "
624 "%" GST_TIME_FORMAT " (duration: %" GST_TIME_FORMAT ")",
625 GST_TIME_ARGS (timestamp), GST_TIME_ARGS (timestamp + duration),
626 GST_TIME_ARGS (duration));
628 event = gst_event_new_custom (GST_EVENT_GAP,
629 gst_structure_new_id (GST_QUARK (EVENT_GAP),
630 GST_QUARK (TIMESTAMP), GST_TYPE_CLOCK_TIME, timestamp,
631 GST_QUARK (DURATION), GST_TYPE_CLOCK_TIME, duration, NULL));
637 * gst_event_parse_gap:
638 * @event: a #GstEvent of type #GST_EVENT_GAP
639 * @timestamp: (out) (allow-none): location where to store the
640 * start time (pts) of the gap, or %NULL
641 * @duration: (out) (allow-none): location where to store the duration of
644 * Extract timestamp and duration from a new GAP event.
647 gst_event_parse_gap (GstEvent * event, GstClockTime * timestamp,
648 GstClockTime * duration)
650 GstStructure *structure;
652 g_return_if_fail (GST_IS_EVENT (event));
653 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_GAP);
655 structure = GST_EVENT_STRUCTURE (event);
656 gst_structure_id_get (structure,
657 GST_QUARK (TIMESTAMP), GST_TYPE_CLOCK_TIME, timestamp,
658 GST_QUARK (DURATION), GST_TYPE_CLOCK_TIME, duration, NULL);
662 * gst_event_new_caps:
663 * @caps: (transfer none): a #GstCaps
665 * Create a new CAPS event for @caps. The caps event can only travel downstream
666 * synchronized with the buffer flow and contains the format of the buffers
667 * that will follow after the event.
669 * Returns: (transfer full): the new CAPS event.
672 gst_event_new_caps (GstCaps * caps)
676 g_return_val_if_fail (caps != NULL, NULL);
677 g_return_val_if_fail (gst_caps_is_fixed (caps), NULL);
679 GST_CAT_INFO (GST_CAT_EVENT, "creating caps event %" GST_PTR_FORMAT, caps);
681 event = gst_event_new_custom (GST_EVENT_CAPS,
682 gst_structure_new_id (GST_QUARK (EVENT_CAPS),
683 GST_QUARK (CAPS), GST_TYPE_CAPS, caps, NULL));
689 * gst_event_parse_caps:
690 * @event: The event to parse
691 * @caps: (out) (transfer none): A pointer to the caps
693 * Get the caps from @event. The caps remains valid as long as @event remains
697 gst_event_parse_caps (GstEvent * event, GstCaps ** caps)
699 GstStructure *structure;
701 g_return_if_fail (GST_IS_EVENT (event));
702 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_CAPS);
704 structure = GST_EVENT_STRUCTURE (event);
707 g_value_get_boxed (gst_structure_id_get_value (structure,
712 * gst_event_new_segment:
713 * @segment: (transfer none): a #GstSegment
715 * Create a new SEGMENT event for @segment. The segment event can only travel
716 * downstream synchronized with the buffer flow and contains timing information
717 * and playback properties for the buffers that will follow.
719 * The newsegment event marks the range of buffers to be processed. All
720 * data not within the segment range is not to be processed. This can be
721 * used intelligently by plugins to apply more efficient methods of skipping
722 * unneeded data. The valid range is expressed with the @start and @stop
725 * The time value of the segment is used in conjunction with the start
726 * value to convert the buffer timestamps into the stream time. This is
727 * usually done in sinks to report the current stream_time.
728 * @time represents the stream_time of a buffer carrying a timestamp of
729 * @start. @time cannot be -1.
731 * @start cannot be -1, @stop can be -1. If there
732 * is a valid @stop given, it must be greater or equal the @start, including
733 * when the indicated playback @rate is < 0.
735 * The @applied_rate value provides information about any rate adjustment that
736 * has already been made to the timestamps and content on the buffers of the
737 * stream. (@rate * @applied_rate) should always equal the rate that has been
738 * requested for playback. For example, if an element has an input segment
739 * with intended playback @rate of 2.0 and applied_rate of 1.0, it can adjust
740 * incoming timestamps and buffer content by half and output a newsegment event
741 * with @rate of 1.0 and @applied_rate of 2.0
743 * After a newsegment event, the buffer stream time is calculated with:
745 * time + (TIMESTAMP(buf) - start) * ABS (rate * applied_rate)
747 * Returns: (transfer full): the new SEGMENT event.
750 gst_event_new_segment (const GstSegment * segment)
754 g_return_val_if_fail (segment != NULL, NULL);
755 g_return_val_if_fail (segment->rate != 0.0, NULL);
756 g_return_val_if_fail (segment->applied_rate != 0.0, NULL);
757 g_return_val_if_fail (segment->format != GST_FORMAT_UNDEFINED, NULL);
759 GST_CAT_INFO (GST_CAT_EVENT, "creating segment event %" GST_SEGMENT_FORMAT,
762 event = gst_event_new_custom (GST_EVENT_SEGMENT,
763 gst_structure_new_id (GST_QUARK (EVENT_SEGMENT),
764 GST_QUARK (SEGMENT), GST_TYPE_SEGMENT, segment, NULL));
770 * gst_event_parse_segment:
771 * @event: The event to parse
772 * @segment: (out) (transfer none): a pointer to a #GstSegment
774 * Parses a segment @event and stores the result in the given @segment location.
775 * @segment remains valid only until the @event is freed. Don't modify the segment
776 * and make a copy if you want to modify it or store it for later use.
779 gst_event_parse_segment (GstEvent * event, const GstSegment ** segment)
781 GstStructure *structure;
783 g_return_if_fail (GST_IS_EVENT (event));
784 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_SEGMENT);
787 structure = GST_EVENT_STRUCTURE (event);
788 *segment = g_value_get_boxed (gst_structure_id_get_value (structure,
789 GST_QUARK (SEGMENT)));
794 * gst_event_copy_segment:
795 * @event: The event to parse
796 * @segment: a pointer to a #GstSegment
798 * Parses a segment @event and copies the #GstSegment into the location
802 gst_event_copy_segment (GstEvent * event, GstSegment * segment)
804 const GstSegment *src;
806 g_return_if_fail (GST_IS_EVENT (event));
807 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_SEGMENT);
810 gst_event_parse_segment (event, &src);
811 gst_segment_copy_into (src, segment);
817 * @taglist: (transfer full): metadata list. The event will take ownership
820 * Generates a metadata tag event from the given @taglist.
822 * The scope of the taglist specifies if the taglist applies to the
823 * complete medium or only to this specific stream. As the tag event
824 * is a sticky event, elements should merge tags received from
825 * upstream with a given scope with their own tags with the same
826 * scope and create a new tag event from it.
828 * Returns: (transfer full): a new #GstEvent
831 gst_event_new_tag (GstTagList * taglist)
834 GValue val = G_VALUE_INIT;
835 const gchar *names[] = { "GstTagList-stream", "GstTagList-global" };
837 g_return_val_if_fail (taglist != NULL, NULL);
839 s = gst_structure_new_empty (names[gst_tag_list_get_scope (taglist)]);
840 g_value_init (&val, GST_TYPE_TAG_LIST);
841 g_value_take_boxed (&val, taglist);
842 gst_structure_id_take_value (s, GST_QUARK (TAGLIST), &val);
843 return gst_event_new_custom (GST_EVENT_TAG, s);
847 * gst_event_parse_tag:
848 * @event: a tag event
849 * @taglist: (out) (transfer none): pointer to metadata list
851 * Parses a tag @event and stores the results in the given @taglist location.
852 * No reference to the taglist will be returned, it remains valid only until
853 * the @event is freed. Don't modify or free the taglist, make a copy if you
854 * want to modify it or store it for later use.
857 gst_event_parse_tag (GstEvent * event, GstTagList ** taglist)
861 g_return_if_fail (GST_IS_EVENT (event));
862 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_TAG);
864 val = gst_structure_id_get_value (GST_EVENT_STRUCTURE (event),
865 GST_QUARK (TAGLIST));
868 *taglist = (GstTagList *) g_value_get_boxed (val);
871 /* buffersize event */
873 * gst_event_new_buffer_size:
874 * @format: buffer format
875 * @minsize: minimum buffer size
876 * @maxsize: maximum buffer size
877 * @async: thread behavior
879 * Create a new buffersize event. The event is sent downstream and notifies
880 * elements that they should provide a buffer of the specified dimensions.
882 * When the @async flag is set, a thread boundary is preferred.
884 * Returns: (transfer full): a new #GstEvent
887 gst_event_new_buffer_size (GstFormat format, gint64 minsize,
888 gint64 maxsize, gboolean async)
891 GstStructure *structure;
893 GST_CAT_INFO (GST_CAT_EVENT,
894 "creating buffersize format %s, minsize %" G_GINT64_FORMAT
895 ", maxsize %" G_GINT64_FORMAT ", async %d", gst_format_get_name (format),
896 minsize, maxsize, async);
898 structure = gst_structure_new_id (GST_QUARK (EVENT_BUFFER_SIZE),
899 GST_QUARK (FORMAT), GST_TYPE_FORMAT, format,
900 GST_QUARK (MINSIZE), G_TYPE_INT64, minsize,
901 GST_QUARK (MAXSIZE), G_TYPE_INT64, maxsize,
902 GST_QUARK (ASYNC), G_TYPE_BOOLEAN, async, NULL);
903 event = gst_event_new_custom (GST_EVENT_BUFFERSIZE, structure);
909 * gst_event_parse_buffer_size:
910 * @event: The event to query
911 * @format: (out): A pointer to store the format in
912 * @minsize: (out): A pointer to store the minsize in
913 * @maxsize: (out): A pointer to store the maxsize in
914 * @async: (out): A pointer to store the async-flag in
916 * Get the format, minsize, maxsize and async-flag in the buffersize event.
919 gst_event_parse_buffer_size (GstEvent * event, GstFormat * format,
920 gint64 * minsize, gint64 * maxsize, gboolean * async)
922 const GstStructure *structure;
924 g_return_if_fail (GST_IS_EVENT (event));
925 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_BUFFERSIZE);
927 structure = GST_EVENT_STRUCTURE (event);
929 *format = (GstFormat)
930 g_value_get_enum (gst_structure_id_get_value (structure,
931 GST_QUARK (FORMAT)));
934 g_value_get_int64 (gst_structure_id_get_value (structure,
935 GST_QUARK (MINSIZE)));
938 g_value_get_int64 (gst_structure_id_get_value (structure,
939 GST_QUARK (MAXSIZE)));
942 g_value_get_boolean (gst_structure_id_get_value (structure,
948 * @type: the QoS type
949 * @proportion: the proportion of the qos message
950 * @diff: The time difference of the last Clock sync
951 * @timestamp: The timestamp of the buffer
953 * Allocate a new qos event with the given values.
954 * The QOS event is generated in an element that wants an upstream
955 * element to either reduce or increase its rate because of
956 * high/low CPU load or other resource usage such as network performance or
957 * throttling. Typically sinks generate these events for each buffer
960 * @type indicates the reason for the QoS event. #GST_QOS_TYPE_OVERFLOW is
961 * used when a buffer arrived in time or when the sink cannot keep up with
962 * the upstream datarate. #GST_QOS_TYPE_UNDERFLOW is when the sink is not
963 * receiving buffers fast enough and thus has to drop late buffers.
964 * #GST_QOS_TYPE_THROTTLE is used when the datarate is artificially limited
965 * by the application, for example to reduce power consumption.
967 * @proportion indicates the real-time performance of the streaming in the
968 * element that generated the QoS event (usually the sink). The value is
969 * generally computed based on more long term statistics about the streams
970 * timestamps compared to the clock.
971 * A value < 1.0 indicates that the upstream element is producing data faster
972 * than real-time. A value > 1.0 indicates that the upstream element is not
973 * producing data fast enough. 1.0 is the ideal @proportion value. The
974 * proportion value can safely be used to lower or increase the quality of
977 * @diff is the difference against the clock in running time of the last
978 * buffer that caused the element to generate the QOS event. A negative value
979 * means that the buffer with @timestamp arrived in time. A positive value
980 * indicates how late the buffer with @timestamp was. When throttling is
981 * enabled, @diff will be set to the requested throttling interval.
983 * @timestamp is the timestamp of the last buffer that cause the element
984 * to generate the QOS event. It is expressed in running time and thus an ever
987 * The upstream element can use the @diff and @timestamp values to decide
988 * whether to process more buffers. For positive @diff, all buffers with
989 * timestamp <= @timestamp + @diff will certainly arrive late in the sink
990 * as well. A (negative) @diff value so that @timestamp + @diff would yield a
991 * result smaller than 0 is not allowed.
993 * The application can use general event probes to intercept the QoS
994 * event and implement custom application specific QoS handling.
996 * Returns: (transfer full): a new QOS event.
999 gst_event_new_qos (GstQOSType type, gdouble proportion,
1000 GstClockTimeDiff diff, GstClockTime timestamp)
1003 GstStructure *structure;
1005 /* diff must be positive or timestamp + diff must be positive */
1006 g_return_val_if_fail (diff >= 0 || -diff <= timestamp, NULL);
1008 GST_CAT_LOG (GST_CAT_EVENT,
1009 "creating qos type %d, proportion %lf, diff %" G_GINT64_FORMAT
1010 ", timestamp %" GST_TIME_FORMAT, type, proportion,
1011 diff, GST_TIME_ARGS (timestamp));
1013 structure = gst_structure_new_id (GST_QUARK (EVENT_QOS),
1014 GST_QUARK (TYPE), GST_TYPE_QOS_TYPE, type,
1015 GST_QUARK (PROPORTION), G_TYPE_DOUBLE, proportion,
1016 GST_QUARK (DIFF), G_TYPE_INT64, diff,
1017 GST_QUARK (TIMESTAMP), G_TYPE_UINT64, timestamp, NULL);
1018 event = gst_event_new_custom (GST_EVENT_QOS, structure);
1024 * gst_event_parse_qos:
1025 * @event: The event to query
1026 * @type: (out): A pointer to store the QoS type in
1027 * @proportion: (out): A pointer to store the proportion in
1028 * @diff: (out): A pointer to store the diff in
1029 * @timestamp: (out): A pointer to store the timestamp in
1031 * Get the type, proportion, diff and timestamp in the qos event. See
1032 * gst_event_new_qos() for more information about the different QoS values.
1035 gst_event_parse_qos (GstEvent * event, GstQOSType * type,
1036 gdouble * proportion, GstClockTimeDiff * diff, GstClockTime * timestamp)
1038 const GstStructure *structure;
1040 g_return_if_fail (GST_IS_EVENT (event));
1041 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_QOS);
1043 structure = GST_EVENT_STRUCTURE (event);
1045 *type = (GstQOSType)
1046 g_value_get_enum (gst_structure_id_get_value (structure,
1050 g_value_get_double (gst_structure_id_get_value (structure,
1051 GST_QUARK (PROPORTION)));
1054 g_value_get_int64 (gst_structure_id_get_value (structure,
1058 g_value_get_uint64 (gst_structure_id_get_value (structure,
1059 GST_QUARK (TIMESTAMP)));
1063 * gst_event_new_seek:
1064 * @rate: The new playback rate
1065 * @format: The format of the seek values
1066 * @flags: The optional seek flags
1067 * @start_type: The type and flags for the new start position
1068 * @start: The value of the new start position
1069 * @stop_type: The type and flags for the new stop position
1070 * @stop: The value of the new stop position
1072 * Allocate a new seek event with the given parameters.
1074 * The seek event configures playback of the pipeline between @start to @stop
1075 * at the speed given in @rate, also called a playback segment.
1076 * The @start and @stop values are expressed in @format.
1078 * A @rate of 1.0 means normal playback rate, 2.0 means double speed.
1079 * Negatives values means backwards playback. A value of 0.0 for the
1080 * rate is not allowed and should be accomplished instead by PAUSING the
1083 * A pipeline has a default playback segment configured with a start
1084 * position of 0, a stop position of -1 and a rate of 1.0. The currently
1085 * configured playback segment can be queried with #GST_QUERY_SEGMENT.
1087 * @start_type and @stop_type specify how to adjust the currently configured
1088 * start and stop fields in playback segment. Adjustments can be made relative
1089 * or absolute to the last configured values. A type of #GST_SEEK_TYPE_NONE
1090 * means that the position should not be updated.
1092 * When the rate is positive and @start has been updated, playback will start
1093 * from the newly configured start position.
1095 * For negative rates, playback will start from the newly configured stop
1096 * position (if any). If the stop position is updated, it must be different from
1097 * -1 (#GST_CLOCK_TIME_NONE) for negative rates.
1099 * It is not possible to seek relative to the current playback position, to do
1100 * this, PAUSE the pipeline, query the current playback position with
1101 * #GST_QUERY_POSITION and update the playback segment current position with a
1102 * #GST_SEEK_TYPE_SET to the desired position.
1104 * Returns: (transfer full): a new seek event.
1107 gst_event_new_seek (gdouble rate, GstFormat format, GstSeekFlags flags,
1108 GstSeekType start_type, gint64 start, GstSeekType stop_type, gint64 stop)
1111 GstStructure *structure;
1113 g_return_val_if_fail (rate != 0.0, NULL);
1115 if (format == GST_FORMAT_TIME) {
1116 GST_CAT_INFO (GST_CAT_EVENT,
1117 "creating seek rate %lf, format TIME, flags %d, "
1118 "start_type %d, start %" GST_TIME_FORMAT ", "
1119 "stop_type %d, stop %" GST_TIME_FORMAT,
1120 rate, flags, start_type, GST_TIME_ARGS (start),
1121 stop_type, GST_TIME_ARGS (stop));
1123 GST_CAT_INFO (GST_CAT_EVENT,
1124 "creating seek rate %lf, format %s, flags %d, "
1125 "start_type %d, start %" G_GINT64_FORMAT ", "
1126 "stop_type %d, stop %" G_GINT64_FORMAT,
1127 rate, gst_format_get_name (format), flags, start_type, start, stop_type,
1131 structure = gst_structure_new_id (GST_QUARK (EVENT_SEEK),
1132 GST_QUARK (RATE), G_TYPE_DOUBLE, rate,
1133 GST_QUARK (FORMAT), GST_TYPE_FORMAT, format,
1134 GST_QUARK (FLAGS), GST_TYPE_SEEK_FLAGS, flags,
1135 GST_QUARK (CUR_TYPE), GST_TYPE_SEEK_TYPE, start_type,
1136 GST_QUARK (CUR), G_TYPE_INT64, start,
1137 GST_QUARK (STOP_TYPE), GST_TYPE_SEEK_TYPE, stop_type,
1138 GST_QUARK (STOP), G_TYPE_INT64, stop, NULL);
1139 event = gst_event_new_custom (GST_EVENT_SEEK, structure);
1145 * gst_event_parse_seek:
1146 * @event: a seek event
1147 * @rate: (out): result location for the rate
1148 * @format: (out): result location for the stream format
1149 * @flags: (out): result location for the #GstSeekFlags
1150 * @start_type: (out): result location for the #GstSeekType of the start position
1151 * @start: (out): result location for the start position expressed in @format
1152 * @stop_type: (out): result location for the #GstSeekType of the stop position
1153 * @stop: (out): result location for the stop position expressed in @format
1155 * Parses a seek @event and stores the results in the given result locations.
1158 gst_event_parse_seek (GstEvent * event, gdouble * rate,
1159 GstFormat * format, GstSeekFlags * flags, GstSeekType * start_type,
1160 gint64 * start, GstSeekType * stop_type, gint64 * stop)
1162 const GstStructure *structure;
1164 g_return_if_fail (GST_IS_EVENT (event));
1165 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_SEEK);
1167 structure = GST_EVENT_STRUCTURE (event);
1170 g_value_get_double (gst_structure_id_get_value (structure,
1173 *format = (GstFormat)
1174 g_value_get_enum (gst_structure_id_get_value (structure,
1175 GST_QUARK (FORMAT)));
1177 *flags = (GstSeekFlags)
1178 g_value_get_flags (gst_structure_id_get_value (structure,
1179 GST_QUARK (FLAGS)));
1181 *start_type = (GstSeekType)
1182 g_value_get_enum (gst_structure_id_get_value (structure,
1183 GST_QUARK (CUR_TYPE)));
1186 g_value_get_int64 (gst_structure_id_get_value (structure,
1189 *stop_type = (GstSeekType)
1190 g_value_get_enum (gst_structure_id_get_value (structure,
1191 GST_QUARK (STOP_TYPE)));
1194 g_value_get_int64 (gst_structure_id_get_value (structure,
1199 * gst_event_new_navigation:
1200 * @structure: (transfer full): description of the event. The event will take
1201 * ownership of the structure.
1203 * Create a new navigation event from the given description.
1205 * Returns: (transfer full): a new #GstEvent
1208 gst_event_new_navigation (GstStructure * structure)
1210 g_return_val_if_fail (structure != NULL, NULL);
1212 return gst_event_new_custom (GST_EVENT_NAVIGATION, structure);
1216 * gst_event_new_latency:
1217 * @latency: the new latency value
1219 * Create a new latency event. The event is sent upstream from the sinks and
1220 * notifies elements that they should add an additional @latency to the
1221 * running time before synchronising against the clock.
1223 * The latency is mostly used in live sinks and is always expressed in
1226 * Returns: (transfer full): a new #GstEvent
1229 gst_event_new_latency (GstClockTime latency)
1232 GstStructure *structure;
1234 GST_CAT_INFO (GST_CAT_EVENT,
1235 "creating latency event %" GST_TIME_FORMAT, GST_TIME_ARGS (latency));
1237 structure = gst_structure_new_id (GST_QUARK (EVENT_LATENCY),
1238 GST_QUARK (LATENCY), G_TYPE_UINT64, latency, NULL);
1239 event = gst_event_new_custom (GST_EVENT_LATENCY, structure);
1245 * gst_event_parse_latency:
1246 * @event: The event to query
1247 * @latency: (out): A pointer to store the latency in.
1249 * Get the latency in the latency event.
1252 gst_event_parse_latency (GstEvent * event, GstClockTime * latency)
1254 g_return_if_fail (GST_IS_EVENT (event));
1255 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_LATENCY);
1259 g_value_get_uint64 (gst_structure_id_get_value (GST_EVENT_STRUCTURE
1260 (event), GST_QUARK (LATENCY)));
1264 * gst_event_new_step:
1265 * @format: the format of @amount
1266 * @amount: the amount of data to step
1267 * @rate: the step rate
1268 * @flush: flushing steps
1269 * @intermediate: intermediate steps
1271 * Create a new step event. The purpose of the step event is to instruct a sink
1272 * to skip @amount (expressed in @format) of media. It can be used to implement
1273 * stepping through the video frame by frame or for doing fast trick modes.
1275 * A rate of <= 0.0 is not allowed. Pause the pipeline, for the effect of rate
1276 * = 0.0 or first reverse the direction of playback using a seek event to get
1277 * the same effect as rate < 0.0.
1279 * The @flush flag will clear any pending data in the pipeline before starting
1280 * the step operation.
1282 * The @intermediate flag instructs the pipeline that this step operation is
1283 * part of a larger step operation.
1285 * Returns: (transfer full): a new #GstEvent
1288 gst_event_new_step (GstFormat format, guint64 amount, gdouble rate,
1289 gboolean flush, gboolean intermediate)
1292 GstStructure *structure;
1294 g_return_val_if_fail (rate > 0.0, NULL);
1296 GST_CAT_INFO (GST_CAT_EVENT, "creating step event");
1298 structure = gst_structure_new_id (GST_QUARK (EVENT_STEP),
1299 GST_QUARK (FORMAT), GST_TYPE_FORMAT, format,
1300 GST_QUARK (AMOUNT), G_TYPE_UINT64, amount,
1301 GST_QUARK (RATE), G_TYPE_DOUBLE, rate,
1302 GST_QUARK (FLUSH), G_TYPE_BOOLEAN, flush,
1303 GST_QUARK (INTERMEDIATE), G_TYPE_BOOLEAN, intermediate, NULL);
1304 event = gst_event_new_custom (GST_EVENT_STEP, structure);
1310 * gst_event_parse_step:
1311 * @event: The event to query
1312 * @format: (out) (allow-none): a pointer to store the format in
1313 * @amount: (out) (allow-none): a pointer to store the amount in
1314 * @rate: (out) (allow-none): a pointer to store the rate in
1315 * @flush: (out) (allow-none): a pointer to store the flush boolean in
1316 * @intermediate: (out) (allow-none): a pointer to store the intermediate
1319 * Parse the step event.
1322 gst_event_parse_step (GstEvent * event, GstFormat * format, guint64 * amount,
1323 gdouble * rate, gboolean * flush, gboolean * intermediate)
1325 const GstStructure *structure;
1327 g_return_if_fail (GST_IS_EVENT (event));
1328 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STEP);
1330 structure = GST_EVENT_STRUCTURE (event);
1333 (GstFormat) g_value_get_enum (gst_structure_id_get_value (structure,
1334 GST_QUARK (FORMAT)));
1336 *amount = g_value_get_uint64 (gst_structure_id_get_value (structure,
1337 GST_QUARK (AMOUNT)));
1339 *rate = g_value_get_double (gst_structure_id_get_value (structure,
1342 *flush = g_value_get_boolean (gst_structure_id_get_value (structure,
1343 GST_QUARK (FLUSH)));
1345 *intermediate = g_value_get_boolean (gst_structure_id_get_value (structure,
1346 GST_QUARK (INTERMEDIATE)));
1350 * gst_event_new_reconfigure:
1352 * Create a new reconfigure event. The purpose of the reconfigure event is
1353 * to travel upstream and make elements renegotiate their caps or reconfigure
1354 * their buffer pools. This is useful when changing properties on elements
1355 * or changing the topology of the pipeline.
1357 * Returns: (transfer full): a new #GstEvent
1360 gst_event_new_reconfigure (void)
1364 GST_CAT_INFO (GST_CAT_EVENT, "creating reconfigure event");
1366 event = gst_event_new_custom (GST_EVENT_RECONFIGURE, NULL);
1372 * gst_event_new_sink_message:
1373 * @name: a name for the event
1374 * @msg: (transfer none): the #GstMessage to be posted
1376 * Create a new sink-message event. The purpose of the sink-message event is
1377 * to instruct a sink to post the message contained in the event synchronized
1380 * @name is used to store multiple sticky events on one pad.
1382 * Returns: (transfer full): a new #GstEvent
1384 /* FIXME 0.11: take ownership of msg for consistency? */
1386 gst_event_new_sink_message (const gchar * name, GstMessage * msg)
1389 GstStructure *structure;
1391 g_return_val_if_fail (msg != NULL, NULL);
1393 GST_CAT_INFO (GST_CAT_EVENT, "creating sink-message event");
1395 structure = gst_structure_new_id (g_quark_from_string (name),
1396 GST_QUARK (MESSAGE), GST_TYPE_MESSAGE, msg, NULL);
1397 event = gst_event_new_custom (GST_EVENT_SINK_MESSAGE, structure);
1403 * gst_event_parse_sink_message:
1404 * @event: The event to query
1405 * @msg: (out) (transfer full): a pointer to store the #GstMessage in.
1407 * Parse the sink-message event. Unref @msg after usage.
1410 gst_event_parse_sink_message (GstEvent * event, GstMessage ** msg)
1412 const GstStructure *structure;
1414 g_return_if_fail (GST_IS_EVENT (event));
1415 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_SINK_MESSAGE);
1417 structure = GST_EVENT_STRUCTURE (event);
1420 GST_MESSAGE (g_value_dup_boxed (gst_structure_id_get_value
1421 (structure, GST_QUARK (MESSAGE))));
1425 * gst_event_new_stream_start:
1426 * @stream_id: Identifier for this stream
1428 * Create a new STREAM_START event. The stream start event can only
1429 * travel downstream synchronized with the buffer flow. It is expected
1430 * to be the first event that is sent for a new stream.
1432 * Source elements, demuxers and other elements that create new streams
1433 * are supposed to send this event as the first event of a new stream. It
1434 * should not be send after a flushing seek or in similar situations
1435 * and is used to mark the beginning of a new logical stream. Elements
1436 * combining multiple streams must ensure that this event is only forwarded
1437 * downstream once and not for every single input stream.
1439 * The @stream_id should be a unique string that consists of the upstream
1440 * stream-id, / as separator and a unique stream-id for this specific
1441 * stream. A new stream-id should only be created for a stream if the upstream
1442 * stream is split into (potentially) multiple new streams, e.g. in a demuxer,
1443 * but not for every single element in the pipeline.
1444 * gst_pad_create_stream_id() or gst_pad_create_stream_id_printf() can be
1445 * used to create a stream-id.
1447 * Returns: (transfer full): the new STREAM_START event.
1450 gst_event_new_stream_start (const gchar * stream_id)
1454 g_return_val_if_fail (stream_id != NULL, NULL);
1456 s = gst_structure_new_id (GST_QUARK (EVENT_STREAM_START),
1457 GST_QUARK (STREAM_ID), G_TYPE_STRING, stream_id,
1458 GST_QUARK (FLAGS), GST_TYPE_STREAM_FLAGS, GST_STREAM_FLAG_NONE, NULL);
1460 return gst_event_new_custom (GST_EVENT_STREAM_START, s);
1464 * gst_event_parse_stream_start:
1465 * @event: a stream-start event.
1466 * @stream_id: (out) (transfer none): pointer to store the stream-id
1468 * Parse a stream-id @event and store the result in the given @stream_id
1469 * location. The string stored in @stream_id must not be modified and will
1470 * remain valid only until @event gets freed. Make a copy if you want to
1471 * modify it or store it for later use.
1474 gst_event_parse_stream_start (GstEvent * event, const gchar ** stream_id)
1476 const GstStructure *structure;
1479 g_return_if_fail (event != NULL);
1480 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STREAM_START);
1482 structure = gst_event_get_structure (event);
1483 val = gst_structure_id_get_value (structure, GST_QUARK (STREAM_ID));
1486 *stream_id = g_value_get_string (val);
1490 * gst_event_set_stream_flags:
1491 * @event: a stream-start event
1492 * @flags: the stream flags to set
1497 gst_event_set_stream_flags (GstEvent * event, GstStreamFlags flags)
1499 g_return_if_fail (event != NULL);
1500 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STREAM_START);
1501 g_return_if_fail (gst_event_is_writable (event));
1503 gst_structure_id_set (GST_EVENT_STRUCTURE (event),
1504 GST_QUARK (FLAGS), GST_TYPE_STREAM_FLAGS, flags, NULL);
1508 * gst_event_parse_stream_flags:
1509 * @event: a stream-start event
1510 * @flags: (out): address of variable where to store the stream flags
1515 gst_event_parse_stream_flags (GstEvent * event, GstStreamFlags * flags)
1517 g_return_if_fail (event != NULL);
1518 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STREAM_START);
1521 gst_structure_id_get (GST_EVENT_STRUCTURE (event),
1522 GST_QUARK (FLAGS), GST_TYPE_STREAM_FLAGS, flags, NULL);
1527 * gst_event_set_group_id:
1528 * @event: a stream-start event
1529 * @group_id: the group id to set
1531 * All streams that have the same group id are supposed to be played
1532 * together, i.e. all streams inside a container file should have the
1533 * same group id but different stream ids. The group id should change
1534 * each time the stream is started, resulting in different group ids
1535 * each time a file is played for example.
1537 * Use gst_util_group_id_next() to get a new group id.
1542 gst_event_set_group_id (GstEvent * event, guint group_id)
1544 g_return_if_fail (event != NULL);
1545 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STREAM_START);
1546 g_return_if_fail (gst_event_is_writable (event));
1548 gst_structure_id_set (GST_EVENT_STRUCTURE (event),
1549 GST_QUARK (GROUP_ID), G_TYPE_UINT, group_id, NULL);
1553 * gst_event_parse_group_id:
1554 * @event: a stream-start event
1555 * @group_id: (out): address of variable where to store the group id
1557 * Returns: %TRUE if a group id was set on the event and could be parsed,
1563 gst_event_parse_group_id (GstEvent * event, guint * group_id)
1565 g_return_val_if_fail (event != NULL, FALSE);
1566 g_return_val_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STREAM_START,
1570 return gst_structure_id_get (GST_EVENT_STRUCTURE (event),
1571 GST_QUARK (GROUP_ID), G_TYPE_UINT, group_id, NULL);
1578 * gst_event_new_toc:
1579 * @toc: (transfer none): #GstToc structure.
1580 * @updated: whether @toc was updated or not.
1582 * Generate a TOC event from the given @toc. The purpose of the TOC event is to
1583 * inform elements that some kind of the TOC was found.
1585 * Returns: (transfer full): a new #GstEvent.
1588 gst_event_new_toc (GstToc * toc, gboolean updated)
1590 GstStructure *toc_struct;
1593 g_return_val_if_fail (toc != NULL, NULL);
1595 GST_CAT_INFO (GST_CAT_EVENT, "creating toc event");
1597 /* need different structure names so sticky_multi event stuff on pads
1598 * works, i.e. both TOC events are kept around */
1599 if (gst_toc_get_scope (toc) == GST_TOC_SCOPE_GLOBAL)
1600 id = GST_QUARK (EVENT_TOC_GLOBAL);
1602 id = GST_QUARK (EVENT_TOC_CURRENT);
1604 toc_struct = gst_structure_new_id (id,
1605 GST_QUARK (TOC), GST_TYPE_TOC, toc,
1606 GST_QUARK (UPDATED), G_TYPE_BOOLEAN, updated, NULL);
1608 return gst_event_new_custom (GST_EVENT_TOC, toc_struct);
1612 * gst_event_parse_toc:
1613 * @event: a TOC event.
1614 * @toc: (out) (transfer full): pointer to #GstToc structure.
1615 * @updated: (out): pointer to store TOC updated flag.
1617 * Parse a TOC @event and store the results in the given @toc and @updated locations.
1620 gst_event_parse_toc (GstEvent * event, GstToc ** toc, gboolean * updated)
1622 const GstStructure *structure;
1624 g_return_if_fail (event != NULL);
1625 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_TOC);
1626 g_return_if_fail (toc != NULL);
1628 structure = gst_event_get_structure (event);
1630 gst_structure_id_get (structure,
1631 GST_QUARK (TOC), GST_TYPE_TOC, toc,
1632 GST_QUARK (UPDATED), G_TYPE_BOOLEAN, updated, NULL);
1636 * gst_event_new_toc_select:
1637 * @uid: UID in the TOC to start playback from.
1639 * Generate a TOC select event with the given @uid. The purpose of the
1640 * TOC select event is to start playback based on the TOC's entry with the
1643 * Returns: a new #GstEvent.
1646 gst_event_new_toc_select (const gchar * uid)
1648 GstStructure *structure;
1650 g_return_val_if_fail (uid != NULL, NULL);
1652 GST_CAT_INFO (GST_CAT_EVENT, "creating toc select event for UID: %s", uid);
1654 structure = gst_structure_new_id (GST_QUARK (EVENT_TOC_SELECT),
1655 GST_QUARK (UID), G_TYPE_STRING, uid, NULL);
1657 return gst_event_new_custom (GST_EVENT_TOC_SELECT, structure);
1661 * gst_event_parse_toc_select:
1662 * @event: a TOC select event.
1663 * @uid: (out): storage for the selection UID.
1665 * Parse a TOC select @event and store the results in the given @uid location.
1668 gst_event_parse_toc_select (GstEvent * event, gchar ** uid)
1670 const GstStructure *structure;
1673 g_return_if_fail (event != NULL);
1674 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_TOC_SELECT);
1676 structure = gst_event_get_structure (event);
1677 val = gst_structure_id_get_value (structure, GST_QUARK (UID));
1680 *uid = g_strdup (g_value_get_string (val));
1685 * gst_event_new_segment_done:
1686 * @format: The format of the position being done
1687 * @position: The position of the segment being done
1689 * Create a new segment-done event. This event is sent by elements that
1690 * finish playback of a segment as a result of a segment seek.
1692 * Returns: (transfer full): a new #GstEvent
1695 gst_event_new_segment_done (GstFormat format, gint64 position)
1698 GstStructure *structure;
1700 GST_CAT_INFO (GST_CAT_EVENT, "creating segment-done event");
1702 structure = gst_structure_new_id (GST_QUARK (EVENT_SEGMENT_DONE),
1703 GST_QUARK (FORMAT), GST_TYPE_FORMAT, format,
1704 GST_QUARK (POSITION), G_TYPE_INT64, position, NULL);
1706 event = gst_event_new_custom (GST_EVENT_SEGMENT_DONE, structure);
1712 * gst_event_parse_segment_done:
1713 * @event: A valid #GstEvent of type GST_EVENT_SEGMENT_DONE.
1714 * @format: (out) (allow-none): Result location for the format, or NULL
1715 * @position: (out) (allow-none): Result location for the position, or NULL
1717 * Extracts the position and format from the segment done message.
1721 gst_event_parse_segment_done (GstEvent * event, GstFormat * format,
1724 const GstStructure *structure;
1727 g_return_if_fail (event != NULL);
1728 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_SEGMENT_DONE);
1730 structure = gst_event_get_structure (event);
1732 val = gst_structure_id_get_value (structure, GST_QUARK (FORMAT));
1734 *format = g_value_get_enum (val);
1736 val = gst_structure_id_get_value (structure, GST_QUARK (POSITION));
1737 if (position != NULL)
1738 *position = g_value_get_int64 (val);