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");
74 #include "gst_private.h"
75 #include <string.h> /* memcpy */
79 #include "gstenumtypes.h"
84 GType _gst_event_type = 0;
90 GstStructure *structure;
91 gint64 running_time_offset;
94 #define GST_EVENT_STRUCTURE(e) (((GstEventImpl *)(e))->structure)
103 static GstEventQuarks event_quarks[] = {
104 {GST_EVENT_UNKNOWN, "unknown", 0},
105 {GST_EVENT_FLUSH_START, "flush-start", 0},
106 {GST_EVENT_FLUSH_STOP, "flush-stop", 0},
107 {GST_EVENT_STREAM_START, "stream-start", 0},
108 {GST_EVENT_CAPS, "caps", 0},
109 {GST_EVENT_SEGMENT, "segment", 0},
110 {GST_EVENT_TAG, "tag", 0},
111 {GST_EVENT_TOC, "toc", 0},
112 {GST_EVENT_PROTECTION, "protection", 0},
113 {GST_EVENT_BUFFERSIZE, "buffersize", 0},
114 {GST_EVENT_SINK_MESSAGE, "sink-message", 0},
115 {GST_EVENT_EOS, "eos", 0},
116 {GST_EVENT_SEGMENT_DONE, "segment-done", 0},
117 {GST_EVENT_GAP, "gap", 0},
118 {GST_EVENT_QOS, "qos", 0},
119 {GST_EVENT_SEEK, "seek", 0},
120 {GST_EVENT_NAVIGATION, "navigation", 0},
121 {GST_EVENT_LATENCY, "latency", 0},
122 {GST_EVENT_STEP, "step", 0},
123 {GST_EVENT_RECONFIGURE, "reconfigure", 0},
124 {GST_EVENT_TOC_SELECT, "toc-select", 0},
125 {GST_EVENT_CUSTOM_UPSTREAM, "custom-upstream", 0},
126 {GST_EVENT_CUSTOM_DOWNSTREAM, "custom-downstream", 0},
127 {GST_EVENT_CUSTOM_DOWNSTREAM_OOB, "custom-downstream-oob", 0},
128 {GST_EVENT_CUSTOM_DOWNSTREAM_STICKY, "custom-downstream-sticky", 0},
129 {GST_EVENT_CUSTOM_BOTH, "custom-both", 0},
130 {GST_EVENT_CUSTOM_BOTH_OOB, "custom-both-oob", 0},
135 GST_DEFINE_MINI_OBJECT_TYPE (GstEvent, gst_event);
138 _priv_gst_event_initialize (void)
142 _gst_event_type = gst_event_get_type ();
144 g_type_class_ref (gst_seek_flags_get_type ());
145 g_type_class_ref (gst_seek_type_get_type ());
147 for (i = 0; event_quarks[i].name; i++) {
148 event_quarks[i].quark = g_quark_from_static_string (event_quarks[i].name);
153 * gst_event_type_get_name:
154 * @type: the event type
156 * Get a printable name for the given event type. Do not modify or free.
158 * Returns: a reference to the static name of the event.
161 gst_event_type_get_name (GstEventType type)
165 for (i = 0; event_quarks[i].name; i++) {
166 if (type == event_quarks[i].type)
167 return event_quarks[i].name;
173 * gst_event_type_to_quark:
174 * @type: the event type
176 * Get the unique quark for the given event type.
178 * Returns: the quark associated with the event type
181 gst_event_type_to_quark (GstEventType type)
185 for (i = 0; event_quarks[i].name; i++) {
186 if (type == event_quarks[i].type)
187 return event_quarks[i].quark;
193 * gst_event_type_get_flags:
194 * @type: a #GstEventType
196 * Gets the #GstEventTypeFlags associated with @type.
198 * Returns: a #GstEventTypeFlags.
201 gst_event_type_get_flags (GstEventType type)
203 GstEventTypeFlags ret;
205 ret = type & ((1 << GST_EVENT_NUM_SHIFT) - 1);
211 _gst_event_free (GstEvent * event)
215 g_return_if_fail (event != NULL);
216 g_return_if_fail (GST_IS_EVENT (event));
218 GST_CAT_LOG (GST_CAT_EVENT, "freeing event %p type %s", event,
219 GST_EVENT_TYPE_NAME (event));
221 s = GST_EVENT_STRUCTURE (event);
224 gst_structure_set_parent_refcount (s, NULL);
225 gst_structure_free (s);
228 g_slice_free1 (sizeof (GstEventImpl), event);
231 static void gst_event_init (GstEventImpl * event, GstEventType type);
234 _gst_event_copy (GstEvent * event)
239 copy = g_slice_new0 (GstEventImpl);
241 gst_event_init (copy, GST_EVENT_TYPE (event));
243 GST_EVENT_TIMESTAMP (copy) = GST_EVENT_TIMESTAMP (event);
244 GST_EVENT_SEQNUM (copy) = GST_EVENT_SEQNUM (event);
246 s = GST_EVENT_STRUCTURE (event);
248 GST_EVENT_STRUCTURE (copy) = gst_structure_copy (s);
249 gst_structure_set_parent_refcount (GST_EVENT_STRUCTURE (copy),
250 ©->event.mini_object.refcount);
252 GST_EVENT_STRUCTURE (copy) = NULL;
255 ((GstEventImpl *) copy)->running_time_offset =
256 ((GstEventImpl *) event)->running_time_offset;
258 return GST_EVENT_CAST (copy);
262 gst_event_init (GstEventImpl * event, GstEventType type)
264 gst_mini_object_init (GST_MINI_OBJECT_CAST (event), 0, _gst_event_type,
265 (GstMiniObjectCopyFunction) _gst_event_copy, NULL,
266 (GstMiniObjectFreeFunction) _gst_event_free);
268 GST_EVENT_TYPE (event) = type;
269 GST_EVENT_TIMESTAMP (event) = GST_CLOCK_TIME_NONE;
270 GST_EVENT_SEQNUM (event) = gst_util_seqnum_next ();
271 event->running_time_offset = 0;
276 * gst_event_new_custom:
277 * @type: The type of the new event
278 * @structure: (transfer full): the structure for the event. The event will
279 * take ownership of the structure.
281 * Create a new custom-typed event. This can be used for anything not
282 * handled by other event-specific functions to pass an event to another
285 * Make sure to allocate an event type with the #GST_EVENT_MAKE_TYPE macro,
286 * assigning a free number and filling in the correct direction and
287 * serialization flags.
289 * New custom events can also be created by subclassing the event type if
292 * Returns: (transfer full): the new custom event.
295 gst_event_new_custom (GstEventType type, GstStructure * structure)
299 event = g_slice_new0 (GstEventImpl);
301 GST_CAT_DEBUG (GST_CAT_EVENT, "creating new event %p %s %d", event,
302 gst_event_type_get_name (type), type);
305 /* structure must not have a parent */
306 if (!gst_structure_set_parent_refcount (structure,
307 &event->event.mini_object.refcount))
311 gst_event_init (event, type);
313 GST_EVENT_STRUCTURE (event) = structure;
315 return GST_EVENT_CAST (event);
320 g_slice_free1 (sizeof (GstEventImpl), event);
321 g_warning ("structure is already owned by another object");
327 * gst_event_get_structure:
328 * @event: The #GstEvent.
330 * Access the structure of the event.
332 * Returns: The structure of the event. The structure is still
333 * owned by the event, which means that you should not free it and
334 * that the pointer becomes invalid when you free the event.
339 gst_event_get_structure (GstEvent * event)
341 g_return_val_if_fail (GST_IS_EVENT (event), NULL);
343 return GST_EVENT_STRUCTURE (event);
347 * gst_event_writable_structure:
348 * @event: The #GstEvent.
350 * Get a writable version of the structure.
352 * Returns: (transfer none): The structure of the event. The structure
353 * is still owned by the event, which means that you should not free
354 * it and that the pointer becomes invalid when you free the event.
355 * This function checks if @event is writable and will never return
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 segment 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 segment event
741 * with @rate of 1.0 and @applied_rate of 2.0
743 * After a segment 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.
1034 * @timestamp will be adjusted for any pad offsets of pads it was passing through.
1037 gst_event_parse_qos (GstEvent * event, GstQOSType * type,
1038 gdouble * proportion, GstClockTimeDiff * diff, GstClockTime * timestamp)
1040 const GstStructure *structure;
1042 g_return_if_fail (GST_IS_EVENT (event));
1043 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_QOS);
1045 structure = GST_EVENT_STRUCTURE (event);
1047 *type = (GstQOSType)
1048 g_value_get_enum (gst_structure_id_get_value (structure,
1052 g_value_get_double (gst_structure_id_get_value (structure,
1053 GST_QUARK (PROPORTION)));
1056 g_value_get_int64 (gst_structure_id_get_value (structure,
1059 gint64 offset = gst_event_get_running_time_offset (event);
1060 GstClockTimeDiff diff_ =
1061 g_value_get_int64 (gst_structure_id_get_value (structure,
1065 g_value_get_uint64 (gst_structure_id_get_value (structure,
1066 GST_QUARK (TIMESTAMP)));
1067 /* Catch underflows */
1068 if (*timestamp > -offset)
1069 *timestamp += offset;
1073 /* Make sure that timestamp + diff is always >= 0. Because
1074 * of the running time offset this might not be true */
1075 if (diff_ < 0 && *timestamp < -diff_)
1076 *timestamp = (GstClockTime) - diff_;
1081 * gst_event_new_seek:
1082 * @rate: The new playback rate
1083 * @format: The format of the seek values
1084 * @flags: The optional seek flags
1085 * @start_type: The type and flags for the new start position
1086 * @start: The value of the new start position
1087 * @stop_type: The type and flags for the new stop position
1088 * @stop: The value of the new stop position
1090 * Allocate a new seek event with the given parameters.
1092 * The seek event configures playback of the pipeline between @start to @stop
1093 * at the speed given in @rate, also called a playback segment.
1094 * The @start and @stop values are expressed in @format.
1096 * A @rate of 1.0 means normal playback rate, 2.0 means double speed.
1097 * Negatives values means backwards playback. A value of 0.0 for the
1098 * rate is not allowed and should be accomplished instead by PAUSING the
1101 * A pipeline has a default playback segment configured with a start
1102 * position of 0, a stop position of -1 and a rate of 1.0. The currently
1103 * configured playback segment can be queried with #GST_QUERY_SEGMENT.
1105 * @start_type and @stop_type specify how to adjust the currently configured
1106 * start and stop fields in playback segment. Adjustments can be made relative
1107 * or absolute to the last configured values. A type of #GST_SEEK_TYPE_NONE
1108 * means that the position should not be updated.
1110 * When the rate is positive and @start has been updated, playback will start
1111 * from the newly configured start position.
1113 * For negative rates, playback will start from the newly configured stop
1114 * position (if any). If the stop position is updated, it must be different from
1115 * -1 (#GST_CLOCK_TIME_NONE) for negative rates.
1117 * It is not possible to seek relative to the current playback position, to do
1118 * this, PAUSE the pipeline, query the current playback position with
1119 * #GST_QUERY_POSITION and update the playback segment current position with a
1120 * #GST_SEEK_TYPE_SET to the desired position.
1122 * Returns: (transfer full): a new seek event.
1125 gst_event_new_seek (gdouble rate, GstFormat format, GstSeekFlags flags,
1126 GstSeekType start_type, gint64 start, GstSeekType stop_type, gint64 stop)
1129 GstStructure *structure;
1131 g_return_val_if_fail (rate != 0.0, NULL);
1133 if (format == GST_FORMAT_TIME) {
1134 GST_CAT_INFO (GST_CAT_EVENT,
1135 "creating seek rate %lf, format TIME, flags %d, "
1136 "start_type %d, start %" GST_TIME_FORMAT ", "
1137 "stop_type %d, stop %" GST_TIME_FORMAT,
1138 rate, flags, start_type, GST_TIME_ARGS (start),
1139 stop_type, GST_TIME_ARGS (stop));
1141 GST_CAT_INFO (GST_CAT_EVENT,
1142 "creating seek rate %lf, format %s, flags %d, "
1143 "start_type %d, start %" G_GINT64_FORMAT ", "
1144 "stop_type %d, stop %" G_GINT64_FORMAT,
1145 rate, gst_format_get_name (format), flags, start_type, start, stop_type,
1149 structure = gst_structure_new_id (GST_QUARK (EVENT_SEEK),
1150 GST_QUARK (RATE), G_TYPE_DOUBLE, rate,
1151 GST_QUARK (FORMAT), GST_TYPE_FORMAT, format,
1152 GST_QUARK (FLAGS), GST_TYPE_SEEK_FLAGS, flags,
1153 GST_QUARK (CUR_TYPE), GST_TYPE_SEEK_TYPE, start_type,
1154 GST_QUARK (CUR), G_TYPE_INT64, start,
1155 GST_QUARK (STOP_TYPE), GST_TYPE_SEEK_TYPE, stop_type,
1156 GST_QUARK (STOP), G_TYPE_INT64, stop, NULL);
1157 event = gst_event_new_custom (GST_EVENT_SEEK, structure);
1163 * gst_event_parse_seek:
1164 * @event: a seek event
1165 * @rate: (out): result location for the rate
1166 * @format: (out): result location for the stream format
1167 * @flags: (out): result location for the #GstSeekFlags
1168 * @start_type: (out): result location for the #GstSeekType of the start position
1169 * @start: (out): result location for the start position expressed in @format
1170 * @stop_type: (out): result location for the #GstSeekType of the stop position
1171 * @stop: (out): result location for the stop position expressed in @format
1173 * Parses a seek @event and stores the results in the given result locations.
1176 gst_event_parse_seek (GstEvent * event, gdouble * rate,
1177 GstFormat * format, GstSeekFlags * flags, GstSeekType * start_type,
1178 gint64 * start, GstSeekType * stop_type, gint64 * stop)
1180 const GstStructure *structure;
1182 g_return_if_fail (GST_IS_EVENT (event));
1183 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_SEEK);
1185 structure = GST_EVENT_STRUCTURE (event);
1188 g_value_get_double (gst_structure_id_get_value (structure,
1191 *format = (GstFormat)
1192 g_value_get_enum (gst_structure_id_get_value (structure,
1193 GST_QUARK (FORMAT)));
1195 *flags = (GstSeekFlags)
1196 g_value_get_flags (gst_structure_id_get_value (structure,
1197 GST_QUARK (FLAGS)));
1199 *start_type = (GstSeekType)
1200 g_value_get_enum (gst_structure_id_get_value (structure,
1201 GST_QUARK (CUR_TYPE)));
1204 g_value_get_int64 (gst_structure_id_get_value (structure,
1207 *stop_type = (GstSeekType)
1208 g_value_get_enum (gst_structure_id_get_value (structure,
1209 GST_QUARK (STOP_TYPE)));
1212 g_value_get_int64 (gst_structure_id_get_value (structure,
1217 * gst_event_new_navigation:
1218 * @structure: (transfer full): description of the event. The event will take
1219 * ownership of the structure.
1221 * Create a new navigation event from the given description.
1223 * Returns: (transfer full): a new #GstEvent
1226 gst_event_new_navigation (GstStructure * structure)
1228 g_return_val_if_fail (structure != NULL, NULL);
1230 return gst_event_new_custom (GST_EVENT_NAVIGATION, structure);
1234 * gst_event_new_latency:
1235 * @latency: the new latency value
1237 * Create a new latency event. The event is sent upstream from the sinks and
1238 * notifies elements that they should add an additional @latency to the
1239 * running time before synchronising against the clock.
1241 * The latency is mostly used in live sinks and is always expressed in
1244 * Returns: (transfer full): a new #GstEvent
1247 gst_event_new_latency (GstClockTime latency)
1250 GstStructure *structure;
1252 GST_CAT_INFO (GST_CAT_EVENT,
1253 "creating latency event %" GST_TIME_FORMAT, GST_TIME_ARGS (latency));
1255 structure = gst_structure_new_id (GST_QUARK (EVENT_LATENCY),
1256 GST_QUARK (LATENCY), G_TYPE_UINT64, latency, NULL);
1257 event = gst_event_new_custom (GST_EVENT_LATENCY, structure);
1263 * gst_event_parse_latency:
1264 * @event: The event to query
1265 * @latency: (out): A pointer to store the latency in.
1267 * Get the latency in the latency event.
1270 gst_event_parse_latency (GstEvent * event, GstClockTime * latency)
1272 g_return_if_fail (GST_IS_EVENT (event));
1273 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_LATENCY);
1277 g_value_get_uint64 (gst_structure_id_get_value (GST_EVENT_STRUCTURE
1278 (event), GST_QUARK (LATENCY)));
1282 * gst_event_new_step:
1283 * @format: the format of @amount
1284 * @amount: the amount of data to step
1285 * @rate: the step rate
1286 * @flush: flushing steps
1287 * @intermediate: intermediate steps
1289 * Create a new step event. The purpose of the step event is to instruct a sink
1290 * to skip @amount (expressed in @format) of media. It can be used to implement
1291 * stepping through the video frame by frame or for doing fast trick modes.
1293 * A rate of <= 0.0 is not allowed. Pause the pipeline, for the effect of rate
1294 * = 0.0 or first reverse the direction of playback using a seek event to get
1295 * the same effect as rate < 0.0.
1297 * The @flush flag will clear any pending data in the pipeline before starting
1298 * the step operation.
1300 * The @intermediate flag instructs the pipeline that this step operation is
1301 * part of a larger step operation.
1303 * Returns: (transfer full): a new #GstEvent
1306 gst_event_new_step (GstFormat format, guint64 amount, gdouble rate,
1307 gboolean flush, gboolean intermediate)
1310 GstStructure *structure;
1312 g_return_val_if_fail (rate > 0.0, NULL);
1314 GST_CAT_INFO (GST_CAT_EVENT, "creating step event");
1316 structure = gst_structure_new_id (GST_QUARK (EVENT_STEP),
1317 GST_QUARK (FORMAT), GST_TYPE_FORMAT, format,
1318 GST_QUARK (AMOUNT), G_TYPE_UINT64, amount,
1319 GST_QUARK (RATE), G_TYPE_DOUBLE, rate,
1320 GST_QUARK (FLUSH), G_TYPE_BOOLEAN, flush,
1321 GST_QUARK (INTERMEDIATE), G_TYPE_BOOLEAN, intermediate, NULL);
1322 event = gst_event_new_custom (GST_EVENT_STEP, structure);
1328 * gst_event_parse_step:
1329 * @event: The event to query
1330 * @format: (out) (allow-none): a pointer to store the format in
1331 * @amount: (out) (allow-none): a pointer to store the amount in
1332 * @rate: (out) (allow-none): a pointer to store the rate in
1333 * @flush: (out) (allow-none): a pointer to store the flush boolean in
1334 * @intermediate: (out) (allow-none): a pointer to store the intermediate
1337 * Parse the step event.
1340 gst_event_parse_step (GstEvent * event, GstFormat * format, guint64 * amount,
1341 gdouble * rate, gboolean * flush, gboolean * intermediate)
1343 const GstStructure *structure;
1345 g_return_if_fail (GST_IS_EVENT (event));
1346 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STEP);
1348 structure = GST_EVENT_STRUCTURE (event);
1351 (GstFormat) g_value_get_enum (gst_structure_id_get_value (structure,
1352 GST_QUARK (FORMAT)));
1354 *amount = g_value_get_uint64 (gst_structure_id_get_value (structure,
1355 GST_QUARK (AMOUNT)));
1357 *rate = g_value_get_double (gst_structure_id_get_value (structure,
1360 *flush = g_value_get_boolean (gst_structure_id_get_value (structure,
1361 GST_QUARK (FLUSH)));
1363 *intermediate = g_value_get_boolean (gst_structure_id_get_value (structure,
1364 GST_QUARK (INTERMEDIATE)));
1368 * gst_event_new_reconfigure:
1370 * Create a new reconfigure event. The purpose of the reconfigure event is
1371 * to travel upstream and make elements renegotiate their caps or reconfigure
1372 * their buffer pools. This is useful when changing properties on elements
1373 * or changing the topology of the pipeline.
1375 * Returns: (transfer full): a new #GstEvent
1378 gst_event_new_reconfigure (void)
1382 GST_CAT_INFO (GST_CAT_EVENT, "creating reconfigure event");
1384 event = gst_event_new_custom (GST_EVENT_RECONFIGURE, NULL);
1390 * gst_event_new_sink_message:
1391 * @name: a name for the event
1392 * @msg: (transfer none): the #GstMessage to be posted
1394 * Create a new sink-message event. The purpose of the sink-message event is
1395 * to instruct a sink to post the message contained in the event synchronized
1398 * @name is used to store multiple sticky events on one pad.
1400 * Returns: (transfer full): a new #GstEvent
1402 /* FIXME 2.0: take ownership of msg for consistency? */
1404 gst_event_new_sink_message (const gchar * name, GstMessage * msg)
1407 GstStructure *structure;
1409 g_return_val_if_fail (msg != NULL, NULL);
1411 GST_CAT_INFO (GST_CAT_EVENT, "creating sink-message event");
1413 structure = gst_structure_new_id (g_quark_from_string (name),
1414 GST_QUARK (MESSAGE), GST_TYPE_MESSAGE, msg, NULL);
1415 event = gst_event_new_custom (GST_EVENT_SINK_MESSAGE, structure);
1421 * gst_event_parse_sink_message:
1422 * @event: The event to query
1423 * @msg: (out) (transfer full): a pointer to store the #GstMessage in.
1425 * Parse the sink-message event. Unref @msg after usage.
1428 gst_event_parse_sink_message (GstEvent * event, GstMessage ** msg)
1430 const GstStructure *structure;
1432 g_return_if_fail (GST_IS_EVENT (event));
1433 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_SINK_MESSAGE);
1435 structure = GST_EVENT_STRUCTURE (event);
1438 GST_MESSAGE (g_value_dup_boxed (gst_structure_id_get_value
1439 (structure, GST_QUARK (MESSAGE))));
1443 * gst_event_new_stream_start:
1444 * @stream_id: Identifier for this stream
1446 * Create a new STREAM_START event. The stream start event can only
1447 * travel downstream synchronized with the buffer flow. It is expected
1448 * to be the first event that is sent for a new stream.
1450 * Source elements, demuxers and other elements that create new streams
1451 * are supposed to send this event as the first event of a new stream. It
1452 * should not be sent after a flushing seek or in similar situations
1453 * and is used to mark the beginning of a new logical stream. Elements
1454 * combining multiple streams must ensure that this event is only forwarded
1455 * downstream once and not for every single input stream.
1457 * The @stream_id should be a unique string that consists of the upstream
1458 * stream-id, / as separator and a unique stream-id for this specific
1459 * stream. A new stream-id should only be created for a stream if the upstream
1460 * stream is split into (potentially) multiple new streams, e.g. in a demuxer,
1461 * but not for every single element in the pipeline.
1462 * gst_pad_create_stream_id() or gst_pad_create_stream_id_printf() can be
1463 * used to create a stream-id.
1465 * Returns: (transfer full): the new STREAM_START event.
1468 gst_event_new_stream_start (const gchar * stream_id)
1472 g_return_val_if_fail (stream_id != NULL, NULL);
1474 s = gst_structure_new_id (GST_QUARK (EVENT_STREAM_START),
1475 GST_QUARK (STREAM_ID), G_TYPE_STRING, stream_id,
1476 GST_QUARK (FLAGS), GST_TYPE_STREAM_FLAGS, GST_STREAM_FLAG_NONE, NULL);
1478 return gst_event_new_custom (GST_EVENT_STREAM_START, s);
1482 * gst_event_parse_stream_start:
1483 * @event: a stream-start event.
1484 * @stream_id: (out) (transfer none): pointer to store the stream-id
1486 * Parse a stream-id @event and store the result in the given @stream_id
1487 * location. The string stored in @stream_id must not be modified and will
1488 * remain valid only until @event gets freed. Make a copy if you want to
1489 * modify it or store it for later use.
1492 gst_event_parse_stream_start (GstEvent * event, const gchar ** stream_id)
1494 const GstStructure *structure;
1497 g_return_if_fail (event != NULL);
1498 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STREAM_START);
1500 structure = gst_event_get_structure (event);
1501 val = gst_structure_id_get_value (structure, GST_QUARK (STREAM_ID));
1504 *stream_id = g_value_get_string (val);
1508 * gst_event_set_stream_flags:
1509 * @event: a stream-start event
1510 * @flags: the stream flags to set
1515 gst_event_set_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);
1519 g_return_if_fail (gst_event_is_writable (event));
1521 gst_structure_id_set (GST_EVENT_STRUCTURE (event),
1522 GST_QUARK (FLAGS), GST_TYPE_STREAM_FLAGS, flags, NULL);
1526 * gst_event_parse_stream_flags:
1527 * @event: a stream-start event
1528 * @flags: (out): address of variable where to store the stream flags
1533 gst_event_parse_stream_flags (GstEvent * event, GstStreamFlags * flags)
1535 g_return_if_fail (event != NULL);
1536 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STREAM_START);
1539 gst_structure_id_get (GST_EVENT_STRUCTURE (event),
1540 GST_QUARK (FLAGS), GST_TYPE_STREAM_FLAGS, flags, NULL);
1545 * gst_event_set_group_id:
1546 * @event: a stream-start event
1547 * @group_id: the group id to set
1549 * All streams that have the same group id are supposed to be played
1550 * together, i.e. all streams inside a container file should have the
1551 * same group id but different stream ids. The group id should change
1552 * each time the stream is started, resulting in different group ids
1553 * each time a file is played for example.
1555 * Use gst_util_group_id_next() to get a new group id.
1560 gst_event_set_group_id (GstEvent * event, guint group_id)
1562 g_return_if_fail (event != NULL);
1563 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STREAM_START);
1564 g_return_if_fail (gst_event_is_writable (event));
1566 gst_structure_id_set (GST_EVENT_STRUCTURE (event),
1567 GST_QUARK (GROUP_ID), G_TYPE_UINT, group_id, NULL);
1571 * gst_event_parse_group_id:
1572 * @event: a stream-start event
1573 * @group_id: (out): address of variable where to store the group id
1575 * Returns: %TRUE if a group id was set on the event and could be parsed,
1581 gst_event_parse_group_id (GstEvent * event, guint * group_id)
1583 g_return_val_if_fail (event != NULL, FALSE);
1584 g_return_val_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STREAM_START,
1588 return gst_structure_id_get (GST_EVENT_STRUCTURE (event),
1589 GST_QUARK (GROUP_ID), G_TYPE_UINT, group_id, NULL);
1596 * gst_event_new_toc:
1597 * @toc: (transfer none): #GstToc structure.
1598 * @updated: whether @toc was updated or not.
1600 * Generate a TOC event from the given @toc. The purpose of the TOC event is to
1601 * inform elements that some kind of the TOC was found.
1603 * Returns: (transfer full): a new #GstEvent.
1606 gst_event_new_toc (GstToc * toc, gboolean updated)
1608 GstStructure *toc_struct;
1611 g_return_val_if_fail (toc != NULL, NULL);
1613 GST_CAT_INFO (GST_CAT_EVENT, "creating toc event");
1615 /* need different structure names so sticky_multi event stuff on pads
1616 * works, i.e. both TOC events are kept around */
1617 if (gst_toc_get_scope (toc) == GST_TOC_SCOPE_GLOBAL)
1618 id = GST_QUARK (EVENT_TOC_GLOBAL);
1620 id = GST_QUARK (EVENT_TOC_CURRENT);
1622 toc_struct = gst_structure_new_id (id,
1623 GST_QUARK (TOC), GST_TYPE_TOC, toc,
1624 GST_QUARK (UPDATED), G_TYPE_BOOLEAN, updated, NULL);
1626 return gst_event_new_custom (GST_EVENT_TOC, toc_struct);
1630 * gst_event_parse_toc:
1631 * @event: a TOC event.
1632 * @toc: (out) (transfer full): pointer to #GstToc structure.
1633 * @updated: (out): pointer to store TOC updated flag.
1635 * Parse a TOC @event and store the results in the given @toc and @updated locations.
1638 gst_event_parse_toc (GstEvent * event, GstToc ** toc, gboolean * updated)
1640 const GstStructure *structure;
1642 g_return_if_fail (event != NULL);
1643 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_TOC);
1644 g_return_if_fail (toc != NULL);
1646 structure = gst_event_get_structure (event);
1648 gst_structure_id_get (structure,
1649 GST_QUARK (TOC), GST_TYPE_TOC, toc,
1650 GST_QUARK (UPDATED), G_TYPE_BOOLEAN, updated, NULL);
1654 * gst_event_new_toc_select:
1655 * @uid: UID in the TOC to start playback from.
1657 * Generate a TOC select event with the given @uid. The purpose of the
1658 * TOC select event is to start playback based on the TOC's entry with the
1661 * Returns: a new #GstEvent.
1664 gst_event_new_toc_select (const gchar * uid)
1666 GstStructure *structure;
1668 g_return_val_if_fail (uid != NULL, NULL);
1670 GST_CAT_INFO (GST_CAT_EVENT, "creating toc select event for UID: %s", uid);
1672 structure = gst_structure_new_id (GST_QUARK (EVENT_TOC_SELECT),
1673 GST_QUARK (UID), G_TYPE_STRING, uid, NULL);
1675 return gst_event_new_custom (GST_EVENT_TOC_SELECT, structure);
1679 * gst_event_parse_toc_select:
1680 * @event: a TOC select event.
1681 * @uid: (out) (transfer full) (allow-none): storage for the selection UID.
1683 * Parse a TOC select @event and store the results in the given @uid location.
1686 gst_event_parse_toc_select (GstEvent * event, gchar ** uid)
1688 const GstStructure *structure;
1691 g_return_if_fail (event != NULL);
1692 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_TOC_SELECT);
1694 structure = gst_event_get_structure (event);
1695 val = gst_structure_id_get_value (structure, GST_QUARK (UID));
1698 *uid = g_strdup (g_value_get_string (val));
1703 * gst_event_new_protection:
1704 * @system_id: (transfer none): a string holding a UUID that uniquely
1705 * identifies a protection system.
1706 * @data: (transfer none): a #GstBuffer holding protection system specific
1707 * information. The reference count of the buffer will be incremented by one.
1708 * @origin: a string indicating where the protection
1709 * information carried in the event was extracted from. The allowed values
1710 * of this string will depend upon the protection scheme.
1712 * Creates a new event containing information specific to a particular
1713 * protection system (uniquely identified by @system_id), by which that
1714 * protection system can acquire key(s) to decrypt a protected stream.
1716 * In order for a decryption element to decrypt media
1717 * protected using a specific system, it first needs all the
1718 * protection system specific information necessary to acquire the decryption
1719 * key(s) for that stream. The functions defined here enable this information
1720 * to be passed in events from elements that extract it
1721 * (e.g., ISOBMFF demuxers, MPEG DASH demuxers) to protection decrypter
1722 * elements that use it.
1724 * Events containing protection system specific information are created using
1725 * #gst_event_new_protection, and they can be parsed by downstream elements
1726 * using #gst_event_parse_protection.
1728 * In Common Encryption, protection system specific information may be located
1729 * within ISOBMFF files, both in movie (moov) boxes and movie fragment (moof)
1730 * boxes; it may also be contained in ContentProtection elements within MPEG
1731 * DASH MPDs. The events created by #gst_event_new_protection contain data
1732 * identifying from which of these locations the encapsulated protection system
1733 * specific information originated. This origin information is required as
1734 * some protection systems use different encodings depending upon where the
1735 * information originates.
1737 * The events returned by gst_event_new_protection() are implemented
1738 * in such a way as to ensure that the most recently-pushed protection info
1739 * event of a particular @origin and @system_id will
1740 * be stuck to the output pad of the sending element.
1742 * Returns: a #GST_EVENT_PROTECTION event, if successful; %NULL
1748 gst_event_new_protection (const gchar * system_id,
1749 GstBuffer * data, const gchar * origin)
1755 g_return_val_if_fail (system_id != NULL, NULL);
1756 g_return_val_if_fail (data != NULL, NULL);
1759 g_strconcat ("GstProtectionEvent", origin ? "-" : "",
1760 origin ? origin : "", "-", system_id, NULL);
1762 GST_CAT_INFO (GST_CAT_EVENT, "creating protection event %s", event_name);
1764 s = gst_structure_new (event_name, "data", GST_TYPE_BUFFER, data,
1765 "system_id", G_TYPE_STRING, system_id, NULL);
1767 gst_structure_set (s, "origin", G_TYPE_STRING, origin, NULL);
1768 event = gst_event_new_custom (GST_EVENT_PROTECTION, s);
1770 g_free (event_name);
1775 * gst_event_parse_protection:
1776 * @event: a #GST_EVENT_PROTECTION event.
1777 * @system_id: (out) (allow-none) (transfer none): pointer to store the UUID
1778 * string uniquely identifying a content protection system.
1779 * @data: (out) (allow-none) (transfer none): pointer to store a #GstBuffer
1780 * holding protection system specific information.
1781 * @origin: (allow-none) (transfer none): pointer to store a value that
1782 * indicates where the protection information carried by @event was extracted
1785 * Parses an event containing protection system specific information and stores
1786 * the results in @system_id, @data and @origin. The data stored in @system_id,
1787 * @origin and @data are valid until @event is released.
1792 gst_event_parse_protection (GstEvent * event, const gchar ** system_id,
1793 GstBuffer ** data, const gchar ** origin)
1795 const GstStructure *s;
1797 g_return_if_fail (event != NULL);
1798 g_return_if_fail (GST_IS_EVENT (event));
1799 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_PROTECTION);
1801 s = gst_event_get_structure (event);
1804 *origin = gst_structure_get_string (s, "origin");
1807 *system_id = gst_structure_get_string (s, "system_id");
1810 const GValue *value = gst_structure_get_value (s, "data");
1811 *data = gst_value_get_buffer (value);
1816 * gst_event_new_segment_done:
1817 * @format: The format of the position being done
1818 * @position: The position of the segment being done
1820 * Create a new segment-done event. This event is sent by elements that
1821 * finish playback of a segment as a result of a segment seek.
1823 * Returns: (transfer full): a new #GstEvent
1826 gst_event_new_segment_done (GstFormat format, gint64 position)
1829 GstStructure *structure;
1831 GST_CAT_INFO (GST_CAT_EVENT, "creating segment-done event");
1833 structure = gst_structure_new_id (GST_QUARK (EVENT_SEGMENT_DONE),
1834 GST_QUARK (FORMAT), GST_TYPE_FORMAT, format,
1835 GST_QUARK (POSITION), G_TYPE_INT64, position, NULL);
1837 event = gst_event_new_custom (GST_EVENT_SEGMENT_DONE, structure);
1843 * gst_event_parse_segment_done:
1844 * @event: A valid #GstEvent of type GST_EVENT_SEGMENT_DONE.
1845 * @format: (out) (allow-none): Result location for the format, or %NULL
1846 * @position: (out) (allow-none): Result location for the position, or %NULL
1848 * Extracts the position and format from the segment done message.
1852 gst_event_parse_segment_done (GstEvent * event, GstFormat * format,
1855 const GstStructure *structure;
1858 g_return_if_fail (event != NULL);
1859 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_SEGMENT_DONE);
1861 structure = gst_event_get_structure (event);
1863 val = gst_structure_id_get_value (structure, GST_QUARK (FORMAT));
1865 *format = g_value_get_enum (val);
1867 val = gst_structure_id_get_value (structure, GST_QUARK (POSITION));
1868 if (position != NULL)
1869 *position = g_value_get_int64 (val);