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_BUFFERSIZE, "buffersize", 0},
113 {GST_EVENT_SINK_MESSAGE, "sink-message", 0},
114 {GST_EVENT_EOS, "eos", 0},
115 {GST_EVENT_SEGMENT_DONE, "segment-done", 0},
116 {GST_EVENT_GAP, "gap", 0},
117 {GST_EVENT_QOS, "qos", 0},
118 {GST_EVENT_SEEK, "seek", 0},
119 {GST_EVENT_NAVIGATION, "navigation", 0},
120 {GST_EVENT_LATENCY, "latency", 0},
121 {GST_EVENT_STEP, "step", 0},
122 {GST_EVENT_RECONFIGURE, "reconfigure", 0},
123 {GST_EVENT_TOC_SELECT, "toc-select", 0},
124 {GST_EVENT_CUSTOM_UPSTREAM, "custom-upstream", 0},
125 {GST_EVENT_CUSTOM_DOWNSTREAM, "custom-downstream", 0},
126 {GST_EVENT_CUSTOM_DOWNSTREAM_OOB, "custom-downstream-oob", 0},
127 {GST_EVENT_CUSTOM_DOWNSTREAM_STICKY, "custom-downstream-sticky", 0},
128 {GST_EVENT_CUSTOM_BOTH, "custom-both", 0},
129 {GST_EVENT_CUSTOM_BOTH_OOB, "custom-both-oob", 0},
134 GST_DEFINE_MINI_OBJECT_TYPE (GstEvent, gst_event);
137 _priv_gst_event_initialize (void)
141 _gst_event_type = gst_event_get_type ();
143 g_type_class_ref (gst_seek_flags_get_type ());
144 g_type_class_ref (gst_seek_type_get_type ());
146 for (i = 0; event_quarks[i].name; i++) {
147 event_quarks[i].quark = g_quark_from_static_string (event_quarks[i].name);
152 * gst_event_type_get_name:
153 * @type: the event type
155 * Get a printable name for the given event type. Do not modify or free.
157 * Returns: a reference to the static name of the event.
160 gst_event_type_get_name (GstEventType type)
164 for (i = 0; event_quarks[i].name; i++) {
165 if (type == event_quarks[i].type)
166 return event_quarks[i].name;
172 * gst_event_type_to_quark:
173 * @type: the event type
175 * Get the unique quark for the given event type.
177 * Returns: the quark associated with the event type
180 gst_event_type_to_quark (GstEventType type)
184 for (i = 0; event_quarks[i].name; i++) {
185 if (type == event_quarks[i].type)
186 return event_quarks[i].quark;
192 * gst_event_type_get_flags:
193 * @type: a #GstEventType
195 * Gets the #GstEventTypeFlags associated with @type.
197 * Returns: a #GstEventTypeFlags.
200 gst_event_type_get_flags (GstEventType type)
202 GstEventTypeFlags ret;
204 ret = type & ((1 << GST_EVENT_NUM_SHIFT) - 1);
210 _gst_event_free (GstEvent * event)
214 g_return_if_fail (event != NULL);
215 g_return_if_fail (GST_IS_EVENT (event));
217 GST_CAT_LOG (GST_CAT_EVENT, "freeing event %p type %s", event,
218 GST_EVENT_TYPE_NAME (event));
220 s = GST_EVENT_STRUCTURE (event);
223 gst_structure_set_parent_refcount (s, NULL);
224 gst_structure_free (s);
227 g_slice_free1 (sizeof (GstEventImpl), event);
230 static void gst_event_init (GstEventImpl * event, GstEventType type);
233 _gst_event_copy (GstEvent * event)
238 copy = g_slice_new0 (GstEventImpl);
240 gst_event_init (copy, GST_EVENT_TYPE (event));
242 GST_EVENT_TIMESTAMP (copy) = GST_EVENT_TIMESTAMP (event);
243 GST_EVENT_SEQNUM (copy) = GST_EVENT_SEQNUM (event);
245 s = GST_EVENT_STRUCTURE (event);
247 GST_EVENT_STRUCTURE (copy) = gst_structure_copy (s);
248 gst_structure_set_parent_refcount (GST_EVENT_STRUCTURE (copy),
249 ©->event.mini_object.refcount);
251 GST_EVENT_STRUCTURE (copy) = NULL;
254 ((GstEventImpl *) copy)->running_time_offset =
255 ((GstEventImpl *) event)->running_time_offset;
257 return GST_EVENT_CAST (copy);
261 gst_event_init (GstEventImpl * event, GstEventType type)
263 gst_mini_object_init (GST_MINI_OBJECT_CAST (event), 0, _gst_event_type,
264 (GstMiniObjectCopyFunction) _gst_event_copy, NULL,
265 (GstMiniObjectFreeFunction) _gst_event_free);
267 GST_EVENT_TYPE (event) = type;
268 GST_EVENT_TIMESTAMP (event) = GST_CLOCK_TIME_NONE;
269 GST_EVENT_SEQNUM (event) = gst_util_seqnum_next ();
270 event->running_time_offset = 0;
275 * gst_event_new_custom:
276 * @type: The type of the new event
277 * @structure: (transfer full): the structure for the event. The event will
278 * take ownership of the structure.
280 * Create a new custom-typed event. This can be used for anything not
281 * handled by other event-specific functions to pass an event to another
284 * Make sure to allocate an event type with the #GST_EVENT_MAKE_TYPE macro,
285 * assigning a free number and filling in the correct direction and
286 * serialization flags.
288 * New custom events can also be created by subclassing the event type if
291 * Returns: (transfer full): the new custom event.
294 gst_event_new_custom (GstEventType type, GstStructure * structure)
298 event = g_slice_new0 (GstEventImpl);
300 GST_CAT_DEBUG (GST_CAT_EVENT, "creating new event %p %s %d", event,
301 gst_event_type_get_name (type), type);
304 /* structure must not have a parent */
305 if (!gst_structure_set_parent_refcount (structure,
306 &event->event.mini_object.refcount))
310 gst_event_init (event, type);
312 GST_EVENT_STRUCTURE (event) = structure;
314 return GST_EVENT_CAST (event);
319 g_slice_free1 (sizeof (GstEventImpl), event);
320 g_warning ("structure is already owned by another object");
326 * gst_event_get_structure:
327 * @event: The #GstEvent.
329 * Access the structure of the event.
331 * Returns: The structure of the event. The structure is still
332 * owned by the event, which means that you should not free it and
333 * that the pointer becomes invalid when you free the event.
338 gst_event_get_structure (GstEvent * event)
340 g_return_val_if_fail (GST_IS_EVENT (event), NULL);
342 return GST_EVENT_STRUCTURE (event);
346 * gst_event_writable_structure:
347 * @event: The #GstEvent.
349 * Get a writable version of the structure.
351 * Returns: The structure of the event. The structure is still
352 * owned by the event, which means that you should not free it and
353 * that the pointer becomes invalid when you free the event.
354 * This function checks if @event is writable and will never return NULL.
359 gst_event_writable_structure (GstEvent * event)
361 GstStructure *structure;
363 g_return_val_if_fail (GST_IS_EVENT (event), NULL);
364 g_return_val_if_fail (gst_event_is_writable (event), NULL);
366 structure = GST_EVENT_STRUCTURE (event);
368 if (structure == NULL) {
370 gst_structure_new_id_empty (gst_event_type_to_quark (GST_EVENT_TYPE
372 gst_structure_set_parent_refcount (structure, &event->mini_object.refcount);
373 GST_EVENT_STRUCTURE (event) = structure;
379 * gst_event_has_name:
380 * @event: The #GstEvent.
381 * @name: name to check
383 * Checks if @event has the given @name. This function is usually used to
384 * check the name of a custom event.
386 * Returns: %TRUE if @name matches the name of the event structure.
389 gst_event_has_name (GstEvent * event, const gchar * name)
391 g_return_val_if_fail (GST_IS_EVENT (event), FALSE);
393 if (GST_EVENT_STRUCTURE (event) == NULL)
396 return gst_structure_has_name (GST_EVENT_STRUCTURE (event), name);
400 * gst_event_get_seqnum:
401 * @event: A #GstEvent.
403 * Retrieve the sequence number of a event.
405 * Events have ever-incrementing sequence numbers, which may also be set
406 * explicitly via gst_event_set_seqnum(). Sequence numbers are typically used to
407 * indicate that a event corresponds to some other set of events or messages,
408 * for example an EOS event corresponding to a SEEK event. It is considered good
409 * practice to make this correspondence when possible, though it is not
412 * Note that events and messages share the same sequence number incrementor;
413 * two events or messages will never have the same sequence number unless
414 * that correspondence was made explicitly.
416 * Returns: The event's sequence number.
421 gst_event_get_seqnum (GstEvent * event)
423 g_return_val_if_fail (GST_IS_EVENT (event), -1);
425 return GST_EVENT_SEQNUM (event);
429 * gst_event_set_seqnum:
430 * @event: A #GstEvent.
431 * @seqnum: A sequence number.
433 * Set the sequence number of a event.
435 * This function might be called by the creator of a event to indicate that the
436 * event relates to other events or messages. See gst_event_get_seqnum() for
442 gst_event_set_seqnum (GstEvent * event, guint32 seqnum)
444 g_return_if_fail (GST_IS_EVENT (event));
446 GST_EVENT_SEQNUM (event) = seqnum;
450 * gst_event_get_running_time_offset:
451 * @event: A #GstEvent.
453 * Retrieve the accumulated running time offset of the event.
455 * Events passing through #GstPads that have a running time
456 * offset set via gst_pad_set_offset() will get their offset
457 * adjusted according to the pad's offset.
459 * If the event contains any information that related to the
460 * running time, this information will need to be updated
461 * before usage with this offset.
463 * Returns: The event's running time offset
470 gst_event_get_running_time_offset (GstEvent * event)
472 g_return_val_if_fail (GST_IS_EVENT (event), 0);
474 return ((GstEventImpl *) event)->running_time_offset;
478 * gst_event_set_running_time_offset:
479 * @event: A #GstEvent.
480 * @offset: A the new running time offset
482 * Set the running time offset of a event. See
483 * gst_event_get_running_time_offset() for more information.
490 gst_event_set_running_time_offset (GstEvent * event, gint64 offset)
492 g_return_if_fail (GST_IS_EVENT (event));
494 ((GstEventImpl *) event)->running_time_offset = offset;
498 * gst_event_new_flush_start:
500 * Allocate a new flush start event. The flush start event can be sent
501 * upstream and downstream and travels out-of-bounds with the dataflow.
503 * It marks pads as being flushing and will make them return
504 * #GST_FLOW_FLUSHING when used for data flow with gst_pad_push(),
505 * gst_pad_chain(), gst_pad_get_range() and gst_pad_pull_range().
506 * Any event (except a #GST_EVENT_FLUSH_STOP) received
507 * on a flushing pad will return %FALSE immediately.
509 * Elements should unlock any blocking functions and exit their streaming
510 * functions as fast as possible when this event is received.
512 * This event is typically generated after a seek to flush out all queued data
513 * in the pipeline so that the new media is played as soon as possible.
515 * Returns: (transfer full): a new flush start event.
518 gst_event_new_flush_start (void)
520 return gst_event_new_custom (GST_EVENT_FLUSH_START, NULL);
524 * gst_event_new_flush_stop:
525 * @reset_time: if time should be reset
527 * Allocate a new flush stop event. The flush stop event can be sent
528 * upstream and downstream and travels serialized with the dataflow.
529 * It is typically sent after sending a FLUSH_START event to make the
530 * pads accept data again.
532 * Elements can process this event synchronized with the dataflow since
533 * the preceding FLUSH_START event stopped the dataflow.
535 * This event is typically generated to complete a seek and to resume
538 * Returns: (transfer full): a new flush stop event.
541 gst_event_new_flush_stop (gboolean reset_time)
545 GST_CAT_INFO (GST_CAT_EVENT, "creating flush stop %d", reset_time);
547 event = gst_event_new_custom (GST_EVENT_FLUSH_STOP,
548 gst_structure_new_id (GST_QUARK (EVENT_FLUSH_STOP),
549 GST_QUARK (RESET_TIME), G_TYPE_BOOLEAN, reset_time, NULL));
555 * gst_event_parse_flush_stop:
556 * @event: The event to parse
557 * @reset_time: (out): if time should be reset
559 * Parse the FLUSH_STOP event and retrieve the @reset_time member.
562 gst_event_parse_flush_stop (GstEvent * event, gboolean * reset_time)
564 GstStructure *structure;
566 g_return_if_fail (GST_IS_EVENT (event));
567 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_FLUSH_STOP);
569 structure = GST_EVENT_STRUCTURE (event);
570 if (G_LIKELY (reset_time))
572 g_value_get_boolean (gst_structure_id_get_value (structure,
573 GST_QUARK (RESET_TIME)));
579 * Create a new EOS event. The eos event can only travel downstream
580 * synchronized with the buffer flow. Elements that receive the EOS
581 * event on a pad can return #GST_FLOW_EOS as a #GstFlowReturn
582 * when data after the EOS event arrives.
584 * The EOS event will travel down to the sink elements in the pipeline
585 * which will then post the #GST_MESSAGE_EOS on the bus after they have
586 * finished playing any buffered data.
588 * When all sinks have posted an EOS message, an EOS message is
589 * forwarded to the application.
591 * The EOS event itself will not cause any state transitions of the pipeline.
593 * Returns: (transfer full): the new EOS event.
596 gst_event_new_eos (void)
598 return gst_event_new_custom (GST_EVENT_EOS, NULL);
603 * @timestamp: the start time (pts) of the gap
604 * @duration: the duration of the gap
606 * Create a new GAP event. A gap event can be thought of as conceptually
607 * equivalent to a buffer to signal that there is no data for a certain
608 * amount of time. This is useful to signal a gap to downstream elements
609 * which may wait for data, such as muxers or mixers or overlays, especially
610 * for sparse streams such as subtitle streams.
612 * Returns: (transfer full): the new GAP event.
615 gst_event_new_gap (GstClockTime timestamp, GstClockTime duration)
619 g_return_val_if_fail (GST_CLOCK_TIME_IS_VALID (timestamp), NULL);
621 GST_CAT_TRACE (GST_CAT_EVENT, "creating gap %" GST_TIME_FORMAT " - "
622 "%" GST_TIME_FORMAT " (duration: %" GST_TIME_FORMAT ")",
623 GST_TIME_ARGS (timestamp), GST_TIME_ARGS (timestamp + duration),
624 GST_TIME_ARGS (duration));
626 event = gst_event_new_custom (GST_EVENT_GAP,
627 gst_structure_new_id (GST_QUARK (EVENT_GAP),
628 GST_QUARK (TIMESTAMP), GST_TYPE_CLOCK_TIME, timestamp,
629 GST_QUARK (DURATION), GST_TYPE_CLOCK_TIME, duration, NULL));
635 * gst_event_parse_gap:
636 * @event: a #GstEvent of type #GST_EVENT_GAP
637 * @timestamp: (out) (allow-none): location where to store the
638 * start time (pts) of the gap, or %NULL
639 * @duration: (out) (allow-none): location where to store the duration of
642 * Extract timestamp and duration from a new GAP event.
645 gst_event_parse_gap (GstEvent * event, GstClockTime * timestamp,
646 GstClockTime * duration)
648 GstStructure *structure;
650 g_return_if_fail (GST_IS_EVENT (event));
651 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_GAP);
653 structure = GST_EVENT_STRUCTURE (event);
654 gst_structure_id_get (structure,
655 GST_QUARK (TIMESTAMP), GST_TYPE_CLOCK_TIME, timestamp,
656 GST_QUARK (DURATION), GST_TYPE_CLOCK_TIME, duration, NULL);
660 * gst_event_new_caps:
661 * @caps: (transfer none): a #GstCaps
663 * Create a new CAPS event for @caps. The caps event can only travel downstream
664 * synchronized with the buffer flow and contains the format of the buffers
665 * that will follow after the event.
667 * Returns: (transfer full): the new CAPS event.
670 gst_event_new_caps (GstCaps * caps)
674 g_return_val_if_fail (caps != NULL, NULL);
675 g_return_val_if_fail (gst_caps_is_fixed (caps), NULL);
677 GST_CAT_INFO (GST_CAT_EVENT, "creating caps event %" GST_PTR_FORMAT, caps);
679 event = gst_event_new_custom (GST_EVENT_CAPS,
680 gst_structure_new_id (GST_QUARK (EVENT_CAPS),
681 GST_QUARK (CAPS), GST_TYPE_CAPS, caps, NULL));
687 * gst_event_parse_caps:
688 * @event: The event to parse
689 * @caps: (out) (transfer none): A pointer to the caps
691 * Get the caps from @event. The caps remains valid as long as @event remains
695 gst_event_parse_caps (GstEvent * event, GstCaps ** caps)
697 GstStructure *structure;
699 g_return_if_fail (GST_IS_EVENT (event));
700 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_CAPS);
702 structure = GST_EVENT_STRUCTURE (event);
705 g_value_get_boxed (gst_structure_id_get_value (structure,
710 * gst_event_new_segment:
711 * @segment: (transfer none): a #GstSegment
713 * Create a new SEGMENT event for @segment. The segment event can only travel
714 * downstream synchronized with the buffer flow and contains timing information
715 * and playback properties for the buffers that will follow.
717 * The newsegment event marks the range of buffers to be processed. All
718 * data not within the segment range is not to be processed. This can be
719 * used intelligently by plugins to apply more efficient methods of skipping
720 * unneeded data. The valid range is expressed with the @start and @stop
723 * The time value of the segment is used in conjunction with the start
724 * value to convert the buffer timestamps into the stream time. This is
725 * usually done in sinks to report the current stream_time.
726 * @time represents the stream_time of a buffer carrying a timestamp of
727 * @start. @time cannot be -1.
729 * @start cannot be -1, @stop can be -1. If there
730 * is a valid @stop given, it must be greater or equal the @start, including
731 * when the indicated playback @rate is < 0.
733 * The @applied_rate value provides information about any rate adjustment that
734 * has already been made to the timestamps and content on the buffers of the
735 * stream. (@rate * @applied_rate) should always equal the rate that has been
736 * requested for playback. For example, if an element has an input segment
737 * with intended playback @rate of 2.0 and applied_rate of 1.0, it can adjust
738 * incoming timestamps and buffer content by half and output a newsegment event
739 * with @rate of 1.0 and @applied_rate of 2.0
741 * After a newsegment event, the buffer stream time is calculated with:
743 * time + (TIMESTAMP(buf) - start) * ABS (rate * applied_rate)
745 * Returns: (transfer full): the new SEGMENT event.
748 gst_event_new_segment (const GstSegment * segment)
752 g_return_val_if_fail (segment != NULL, NULL);
753 g_return_val_if_fail (segment->rate != 0.0, NULL);
754 g_return_val_if_fail (segment->applied_rate != 0.0, NULL);
755 g_return_val_if_fail (segment->format != GST_FORMAT_UNDEFINED, NULL);
757 GST_CAT_INFO (GST_CAT_EVENT, "creating segment event %" GST_SEGMENT_FORMAT,
760 event = gst_event_new_custom (GST_EVENT_SEGMENT,
761 gst_structure_new_id (GST_QUARK (EVENT_SEGMENT),
762 GST_QUARK (SEGMENT), GST_TYPE_SEGMENT, segment, NULL));
768 * gst_event_parse_segment:
769 * @event: The event to parse
770 * @segment: (out) (transfer none): a pointer to a #GstSegment
772 * Parses a segment @event and stores the result in the given @segment location.
773 * @segment remains valid only until the @event is freed. Don't modify the segment
774 * and make a copy if you want to modify it or store it for later use.
777 gst_event_parse_segment (GstEvent * event, const GstSegment ** segment)
779 GstStructure *structure;
781 g_return_if_fail (GST_IS_EVENT (event));
782 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_SEGMENT);
785 structure = GST_EVENT_STRUCTURE (event);
786 *segment = g_value_get_boxed (gst_structure_id_get_value (structure,
787 GST_QUARK (SEGMENT)));
792 * gst_event_copy_segment:
793 * @event: The event to parse
794 * @segment: a pointer to a #GstSegment
796 * Parses a segment @event and copies the #GstSegment into the location
800 gst_event_copy_segment (GstEvent * event, GstSegment * segment)
802 const GstSegment *src;
804 g_return_if_fail (GST_IS_EVENT (event));
805 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_SEGMENT);
808 gst_event_parse_segment (event, &src);
809 gst_segment_copy_into (src, segment);
815 * @taglist: (transfer full): metadata list. The event will take ownership
818 * Generates a metadata tag event from the given @taglist.
820 * The scope of the taglist specifies if the taglist applies to the
821 * complete medium or only to this specific stream. As the tag event
822 * is a sticky event, elements should merge tags received from
823 * upstream with a given scope with their own tags with the same
824 * scope and create a new tag event from it.
826 * Returns: (transfer full): a new #GstEvent
829 gst_event_new_tag (GstTagList * taglist)
832 GValue val = G_VALUE_INIT;
833 const gchar *names[] = { "GstTagList-stream", "GstTagList-global" };
835 g_return_val_if_fail (taglist != NULL, NULL);
837 s = gst_structure_new_empty (names[gst_tag_list_get_scope (taglist)]);
838 g_value_init (&val, GST_TYPE_TAG_LIST);
839 g_value_take_boxed (&val, taglist);
840 gst_structure_id_take_value (s, GST_QUARK (TAGLIST), &val);
841 return gst_event_new_custom (GST_EVENT_TAG, s);
845 * gst_event_parse_tag:
846 * @event: a tag event
847 * @taglist: (out) (transfer none): pointer to metadata list
849 * Parses a tag @event and stores the results in the given @taglist location.
850 * No reference to the taglist will be returned, it remains valid only until
851 * the @event is freed. Don't modify or free the taglist, make a copy if you
852 * want to modify it or store it for later use.
855 gst_event_parse_tag (GstEvent * event, GstTagList ** taglist)
859 g_return_if_fail (GST_IS_EVENT (event));
860 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_TAG);
862 val = gst_structure_id_get_value (GST_EVENT_STRUCTURE (event),
863 GST_QUARK (TAGLIST));
866 *taglist = (GstTagList *) g_value_get_boxed (val);
869 /* buffersize event */
871 * gst_event_new_buffer_size:
872 * @format: buffer format
873 * @minsize: minimum buffer size
874 * @maxsize: maximum buffer size
875 * @async: thread behavior
877 * Create a new buffersize event. The event is sent downstream and notifies
878 * elements that they should provide a buffer of the specified dimensions.
880 * When the @async flag is set, a thread boundary is preferred.
882 * Returns: (transfer full): a new #GstEvent
885 gst_event_new_buffer_size (GstFormat format, gint64 minsize,
886 gint64 maxsize, gboolean async)
889 GstStructure *structure;
891 GST_CAT_INFO (GST_CAT_EVENT,
892 "creating buffersize format %s, minsize %" G_GINT64_FORMAT
893 ", maxsize %" G_GINT64_FORMAT ", async %d", gst_format_get_name (format),
894 minsize, maxsize, async);
896 structure = gst_structure_new_id (GST_QUARK (EVENT_BUFFER_SIZE),
897 GST_QUARK (FORMAT), GST_TYPE_FORMAT, format,
898 GST_QUARK (MINSIZE), G_TYPE_INT64, minsize,
899 GST_QUARK (MAXSIZE), G_TYPE_INT64, maxsize,
900 GST_QUARK (ASYNC), G_TYPE_BOOLEAN, async, NULL);
901 event = gst_event_new_custom (GST_EVENT_BUFFERSIZE, structure);
907 * gst_event_parse_buffer_size:
908 * @event: The event to query
909 * @format: (out): A pointer to store the format in
910 * @minsize: (out): A pointer to store the minsize in
911 * @maxsize: (out): A pointer to store the maxsize in
912 * @async: (out): A pointer to store the async-flag in
914 * Get the format, minsize, maxsize and async-flag in the buffersize event.
917 gst_event_parse_buffer_size (GstEvent * event, GstFormat * format,
918 gint64 * minsize, gint64 * maxsize, gboolean * async)
920 const GstStructure *structure;
922 g_return_if_fail (GST_IS_EVENT (event));
923 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_BUFFERSIZE);
925 structure = GST_EVENT_STRUCTURE (event);
927 *format = (GstFormat)
928 g_value_get_enum (gst_structure_id_get_value (structure,
929 GST_QUARK (FORMAT)));
932 g_value_get_int64 (gst_structure_id_get_value (structure,
933 GST_QUARK (MINSIZE)));
936 g_value_get_int64 (gst_structure_id_get_value (structure,
937 GST_QUARK (MAXSIZE)));
940 g_value_get_boolean (gst_structure_id_get_value (structure,
946 * @type: the QoS type
947 * @proportion: the proportion of the qos message
948 * @diff: The time difference of the last Clock sync
949 * @timestamp: The timestamp of the buffer
951 * Allocate a new qos event with the given values.
952 * The QOS event is generated in an element that wants an upstream
953 * element to either reduce or increase its rate because of
954 * high/low CPU load or other resource usage such as network performance or
955 * throttling. Typically sinks generate these events for each buffer
958 * @type indicates the reason for the QoS event. #GST_QOS_TYPE_OVERFLOW is
959 * used when a buffer arrived in time or when the sink cannot keep up with
960 * the upstream datarate. #GST_QOS_TYPE_UNDERFLOW is when the sink is not
961 * receiving buffers fast enough and thus has to drop late buffers.
962 * #GST_QOS_TYPE_THROTTLE is used when the datarate is artificially limited
963 * by the application, for example to reduce power consumption.
965 * @proportion indicates the real-time performance of the streaming in the
966 * element that generated the QoS event (usually the sink). The value is
967 * generally computed based on more long term statistics about the streams
968 * timestamps compared to the clock.
969 * A value < 1.0 indicates that the upstream element is producing data faster
970 * than real-time. A value > 1.0 indicates that the upstream element is not
971 * producing data fast enough. 1.0 is the ideal @proportion value. The
972 * proportion value can safely be used to lower or increase the quality of
975 * @diff is the difference against the clock in running time of the last
976 * buffer that caused the element to generate the QOS event. A negative value
977 * means that the buffer with @timestamp arrived in time. A positive value
978 * indicates how late the buffer with @timestamp was. When throttling is
979 * enabled, @diff will be set to the requested throttling interval.
981 * @timestamp is the timestamp of the last buffer that cause the element
982 * to generate the QOS event. It is expressed in running time and thus an ever
985 * The upstream element can use the @diff and @timestamp values to decide
986 * whether to process more buffers. For positive @diff, all buffers with
987 * timestamp <= @timestamp + @diff will certainly arrive late in the sink
988 * as well. A (negative) @diff value so that @timestamp + @diff would yield a
989 * result smaller than 0 is not allowed.
991 * The application can use general event probes to intercept the QoS
992 * event and implement custom application specific QoS handling.
994 * Returns: (transfer full): a new QOS event.
997 gst_event_new_qos (GstQOSType type, gdouble proportion,
998 GstClockTimeDiff diff, GstClockTime timestamp)
1001 GstStructure *structure;
1003 /* diff must be positive or timestamp + diff must be positive */
1004 g_return_val_if_fail (diff >= 0 || -diff <= timestamp, NULL);
1006 GST_CAT_LOG (GST_CAT_EVENT,
1007 "creating qos type %d, proportion %lf, diff %" G_GINT64_FORMAT
1008 ", timestamp %" GST_TIME_FORMAT, type, proportion,
1009 diff, GST_TIME_ARGS (timestamp));
1011 structure = gst_structure_new_id (GST_QUARK (EVENT_QOS),
1012 GST_QUARK (TYPE), GST_TYPE_QOS_TYPE, type,
1013 GST_QUARK (PROPORTION), G_TYPE_DOUBLE, proportion,
1014 GST_QUARK (DIFF), G_TYPE_INT64, diff,
1015 GST_QUARK (TIMESTAMP), G_TYPE_UINT64, timestamp, NULL);
1016 event = gst_event_new_custom (GST_EVENT_QOS, structure);
1022 * gst_event_parse_qos:
1023 * @event: The event to query
1024 * @type: (out): A pointer to store the QoS type in
1025 * @proportion: (out): A pointer to store the proportion in
1026 * @diff: (out): A pointer to store the diff in
1027 * @timestamp: (out): A pointer to store the timestamp in
1029 * Get the type, proportion, diff and timestamp in the qos event. See
1030 * gst_event_new_qos() for more information about the different QoS values.
1032 * @timestamp will be adjusted for any pad offsets of pads it was passing through.
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,
1057 gint64 offset = gst_event_get_running_time_offset (event);
1060 g_value_get_uint64 (gst_structure_id_get_value (structure,
1061 GST_QUARK (TIMESTAMP)));
1062 /* Catch underflows */
1063 if (*timestamp > -offset)
1064 *timestamp += offset;
1071 * gst_event_new_seek:
1072 * @rate: The new playback rate
1073 * @format: The format of the seek values
1074 * @flags: The optional seek flags
1075 * @start_type: The type and flags for the new start position
1076 * @start: The value of the new start position
1077 * @stop_type: The type and flags for the new stop position
1078 * @stop: The value of the new stop position
1080 * Allocate a new seek event with the given parameters.
1082 * The seek event configures playback of the pipeline between @start to @stop
1083 * at the speed given in @rate, also called a playback segment.
1084 * The @start and @stop values are expressed in @format.
1086 * A @rate of 1.0 means normal playback rate, 2.0 means double speed.
1087 * Negatives values means backwards playback. A value of 0.0 for the
1088 * rate is not allowed and should be accomplished instead by PAUSING the
1091 * A pipeline has a default playback segment configured with a start
1092 * position of 0, a stop position of -1 and a rate of 1.0. The currently
1093 * configured playback segment can be queried with #GST_QUERY_SEGMENT.
1095 * @start_type and @stop_type specify how to adjust the currently configured
1096 * start and stop fields in playback segment. Adjustments can be made relative
1097 * or absolute to the last configured values. A type of #GST_SEEK_TYPE_NONE
1098 * means that the position should not be updated.
1100 * When the rate is positive and @start has been updated, playback will start
1101 * from the newly configured start position.
1103 * For negative rates, playback will start from the newly configured stop
1104 * position (if any). If the stop position is updated, it must be different from
1105 * -1 (#GST_CLOCK_TIME_NONE) for negative rates.
1107 * It is not possible to seek relative to the current playback position, to do
1108 * this, PAUSE the pipeline, query the current playback position with
1109 * #GST_QUERY_POSITION and update the playback segment current position with a
1110 * #GST_SEEK_TYPE_SET to the desired position.
1112 * Returns: (transfer full): a new seek event.
1115 gst_event_new_seek (gdouble rate, GstFormat format, GstSeekFlags flags,
1116 GstSeekType start_type, gint64 start, GstSeekType stop_type, gint64 stop)
1119 GstStructure *structure;
1121 g_return_val_if_fail (rate != 0.0, NULL);
1123 if (format == GST_FORMAT_TIME) {
1124 GST_CAT_INFO (GST_CAT_EVENT,
1125 "creating seek rate %lf, format TIME, flags %d, "
1126 "start_type %d, start %" GST_TIME_FORMAT ", "
1127 "stop_type %d, stop %" GST_TIME_FORMAT,
1128 rate, flags, start_type, GST_TIME_ARGS (start),
1129 stop_type, GST_TIME_ARGS (stop));
1131 GST_CAT_INFO (GST_CAT_EVENT,
1132 "creating seek rate %lf, format %s, flags %d, "
1133 "start_type %d, start %" G_GINT64_FORMAT ", "
1134 "stop_type %d, stop %" G_GINT64_FORMAT,
1135 rate, gst_format_get_name (format), flags, start_type, start, stop_type,
1139 structure = gst_structure_new_id (GST_QUARK (EVENT_SEEK),
1140 GST_QUARK (RATE), G_TYPE_DOUBLE, rate,
1141 GST_QUARK (FORMAT), GST_TYPE_FORMAT, format,
1142 GST_QUARK (FLAGS), GST_TYPE_SEEK_FLAGS, flags,
1143 GST_QUARK (CUR_TYPE), GST_TYPE_SEEK_TYPE, start_type,
1144 GST_QUARK (CUR), G_TYPE_INT64, start,
1145 GST_QUARK (STOP_TYPE), GST_TYPE_SEEK_TYPE, stop_type,
1146 GST_QUARK (STOP), G_TYPE_INT64, stop, NULL);
1147 event = gst_event_new_custom (GST_EVENT_SEEK, structure);
1153 * gst_event_parse_seek:
1154 * @event: a seek event
1155 * @rate: (out): result location for the rate
1156 * @format: (out): result location for the stream format
1157 * @flags: (out): result location for the #GstSeekFlags
1158 * @start_type: (out): result location for the #GstSeekType of the start position
1159 * @start: (out): result location for the start position expressed in @format
1160 * @stop_type: (out): result location for the #GstSeekType of the stop position
1161 * @stop: (out): result location for the stop position expressed in @format
1163 * Parses a seek @event and stores the results in the given result locations.
1166 gst_event_parse_seek (GstEvent * event, gdouble * rate,
1167 GstFormat * format, GstSeekFlags * flags, GstSeekType * start_type,
1168 gint64 * start, GstSeekType * stop_type, gint64 * stop)
1170 const GstStructure *structure;
1172 g_return_if_fail (GST_IS_EVENT (event));
1173 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_SEEK);
1175 structure = GST_EVENT_STRUCTURE (event);
1178 g_value_get_double (gst_structure_id_get_value (structure,
1181 *format = (GstFormat)
1182 g_value_get_enum (gst_structure_id_get_value (structure,
1183 GST_QUARK (FORMAT)));
1185 *flags = (GstSeekFlags)
1186 g_value_get_flags (gst_structure_id_get_value (structure,
1187 GST_QUARK (FLAGS)));
1189 *start_type = (GstSeekType)
1190 g_value_get_enum (gst_structure_id_get_value (structure,
1191 GST_QUARK (CUR_TYPE)));
1194 g_value_get_int64 (gst_structure_id_get_value (structure,
1197 *stop_type = (GstSeekType)
1198 g_value_get_enum (gst_structure_id_get_value (structure,
1199 GST_QUARK (STOP_TYPE)));
1202 g_value_get_int64 (gst_structure_id_get_value (structure,
1207 * gst_event_new_navigation:
1208 * @structure: (transfer full): description of the event. The event will take
1209 * ownership of the structure.
1211 * Create a new navigation event from the given description.
1213 * Returns: (transfer full): a new #GstEvent
1216 gst_event_new_navigation (GstStructure * structure)
1218 g_return_val_if_fail (structure != NULL, NULL);
1220 return gst_event_new_custom (GST_EVENT_NAVIGATION, structure);
1224 * gst_event_new_latency:
1225 * @latency: the new latency value
1227 * Create a new latency event. The event is sent upstream from the sinks and
1228 * notifies elements that they should add an additional @latency to the
1229 * running time before synchronising against the clock.
1231 * The latency is mostly used in live sinks and is always expressed in
1234 * Returns: (transfer full): a new #GstEvent
1237 gst_event_new_latency (GstClockTime latency)
1240 GstStructure *structure;
1242 GST_CAT_INFO (GST_CAT_EVENT,
1243 "creating latency event %" GST_TIME_FORMAT, GST_TIME_ARGS (latency));
1245 structure = gst_structure_new_id (GST_QUARK (EVENT_LATENCY),
1246 GST_QUARK (LATENCY), G_TYPE_UINT64, latency, NULL);
1247 event = gst_event_new_custom (GST_EVENT_LATENCY, structure);
1253 * gst_event_parse_latency:
1254 * @event: The event to query
1255 * @latency: (out): A pointer to store the latency in.
1257 * Get the latency in the latency event.
1260 gst_event_parse_latency (GstEvent * event, GstClockTime * latency)
1262 g_return_if_fail (GST_IS_EVENT (event));
1263 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_LATENCY);
1267 g_value_get_uint64 (gst_structure_id_get_value (GST_EVENT_STRUCTURE
1268 (event), GST_QUARK (LATENCY)));
1272 * gst_event_new_step:
1273 * @format: the format of @amount
1274 * @amount: the amount of data to step
1275 * @rate: the step rate
1276 * @flush: flushing steps
1277 * @intermediate: intermediate steps
1279 * Create a new step event. The purpose of the step event is to instruct a sink
1280 * to skip @amount (expressed in @format) of media. It can be used to implement
1281 * stepping through the video frame by frame or for doing fast trick modes.
1283 * A rate of <= 0.0 is not allowed. Pause the pipeline, for the effect of rate
1284 * = 0.0 or first reverse the direction of playback using a seek event to get
1285 * the same effect as rate < 0.0.
1287 * The @flush flag will clear any pending data in the pipeline before starting
1288 * the step operation.
1290 * The @intermediate flag instructs the pipeline that this step operation is
1291 * part of a larger step operation.
1293 * Returns: (transfer full): a new #GstEvent
1296 gst_event_new_step (GstFormat format, guint64 amount, gdouble rate,
1297 gboolean flush, gboolean intermediate)
1300 GstStructure *structure;
1302 g_return_val_if_fail (rate > 0.0, NULL);
1304 GST_CAT_INFO (GST_CAT_EVENT, "creating step event");
1306 structure = gst_structure_new_id (GST_QUARK (EVENT_STEP),
1307 GST_QUARK (FORMAT), GST_TYPE_FORMAT, format,
1308 GST_QUARK (AMOUNT), G_TYPE_UINT64, amount,
1309 GST_QUARK (RATE), G_TYPE_DOUBLE, rate,
1310 GST_QUARK (FLUSH), G_TYPE_BOOLEAN, flush,
1311 GST_QUARK (INTERMEDIATE), G_TYPE_BOOLEAN, intermediate, NULL);
1312 event = gst_event_new_custom (GST_EVENT_STEP, structure);
1318 * gst_event_parse_step:
1319 * @event: The event to query
1320 * @format: (out) (allow-none): a pointer to store the format in
1321 * @amount: (out) (allow-none): a pointer to store the amount in
1322 * @rate: (out) (allow-none): a pointer to store the rate in
1323 * @flush: (out) (allow-none): a pointer to store the flush boolean in
1324 * @intermediate: (out) (allow-none): a pointer to store the intermediate
1327 * Parse the step event.
1330 gst_event_parse_step (GstEvent * event, GstFormat * format, guint64 * amount,
1331 gdouble * rate, gboolean * flush, gboolean * intermediate)
1333 const GstStructure *structure;
1335 g_return_if_fail (GST_IS_EVENT (event));
1336 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STEP);
1338 structure = GST_EVENT_STRUCTURE (event);
1341 (GstFormat) g_value_get_enum (gst_structure_id_get_value (structure,
1342 GST_QUARK (FORMAT)));
1344 *amount = g_value_get_uint64 (gst_structure_id_get_value (structure,
1345 GST_QUARK (AMOUNT)));
1347 *rate = g_value_get_double (gst_structure_id_get_value (structure,
1350 *flush = g_value_get_boolean (gst_structure_id_get_value (structure,
1351 GST_QUARK (FLUSH)));
1353 *intermediate = g_value_get_boolean (gst_structure_id_get_value (structure,
1354 GST_QUARK (INTERMEDIATE)));
1358 * gst_event_new_reconfigure:
1360 * Create a new reconfigure event. The purpose of the reconfigure event is
1361 * to travel upstream and make elements renegotiate their caps or reconfigure
1362 * their buffer pools. This is useful when changing properties on elements
1363 * or changing the topology of the pipeline.
1365 * Returns: (transfer full): a new #GstEvent
1368 gst_event_new_reconfigure (void)
1372 GST_CAT_INFO (GST_CAT_EVENT, "creating reconfigure event");
1374 event = gst_event_new_custom (GST_EVENT_RECONFIGURE, NULL);
1380 * gst_event_new_sink_message:
1381 * @name: a name for the event
1382 * @msg: (transfer none): the #GstMessage to be posted
1384 * Create a new sink-message event. The purpose of the sink-message event is
1385 * to instruct a sink to post the message contained in the event synchronized
1388 * @name is used to store multiple sticky events on one pad.
1390 * Returns: (transfer full): a new #GstEvent
1392 /* FIXME 0.11: take ownership of msg for consistency? */
1394 gst_event_new_sink_message (const gchar * name, GstMessage * msg)
1397 GstStructure *structure;
1399 g_return_val_if_fail (msg != NULL, NULL);
1401 GST_CAT_INFO (GST_CAT_EVENT, "creating sink-message event");
1403 structure = gst_structure_new_id (g_quark_from_string (name),
1404 GST_QUARK (MESSAGE), GST_TYPE_MESSAGE, msg, NULL);
1405 event = gst_event_new_custom (GST_EVENT_SINK_MESSAGE, structure);
1411 * gst_event_parse_sink_message:
1412 * @event: The event to query
1413 * @msg: (out) (transfer full): a pointer to store the #GstMessage in.
1415 * Parse the sink-message event. Unref @msg after usage.
1418 gst_event_parse_sink_message (GstEvent * event, GstMessage ** msg)
1420 const GstStructure *structure;
1422 g_return_if_fail (GST_IS_EVENT (event));
1423 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_SINK_MESSAGE);
1425 structure = GST_EVENT_STRUCTURE (event);
1428 GST_MESSAGE (g_value_dup_boxed (gst_structure_id_get_value
1429 (structure, GST_QUARK (MESSAGE))));
1433 * gst_event_new_stream_start:
1434 * @stream_id: Identifier for this stream
1436 * Create a new STREAM_START event. The stream start event can only
1437 * travel downstream synchronized with the buffer flow. It is expected
1438 * to be the first event that is sent for a new stream.
1440 * Source elements, demuxers and other elements that create new streams
1441 * are supposed to send this event as the first event of a new stream. It
1442 * should not be send after a flushing seek or in similar situations
1443 * and is used to mark the beginning of a new logical stream. Elements
1444 * combining multiple streams must ensure that this event is only forwarded
1445 * downstream once and not for every single input stream.
1447 * The @stream_id should be a unique string that consists of the upstream
1448 * stream-id, / as separator and a unique stream-id for this specific
1449 * stream. A new stream-id should only be created for a stream if the upstream
1450 * stream is split into (potentially) multiple new streams, e.g. in a demuxer,
1451 * but not for every single element in the pipeline.
1452 * gst_pad_create_stream_id() or gst_pad_create_stream_id_printf() can be
1453 * used to create a stream-id.
1455 * Returns: (transfer full): the new STREAM_START event.
1458 gst_event_new_stream_start (const gchar * stream_id)
1462 g_return_val_if_fail (stream_id != NULL, NULL);
1464 s = gst_structure_new_id (GST_QUARK (EVENT_STREAM_START),
1465 GST_QUARK (STREAM_ID), G_TYPE_STRING, stream_id,
1466 GST_QUARK (FLAGS), GST_TYPE_STREAM_FLAGS, GST_STREAM_FLAG_NONE, NULL);
1468 return gst_event_new_custom (GST_EVENT_STREAM_START, s);
1472 * gst_event_parse_stream_start:
1473 * @event: a stream-start event.
1474 * @stream_id: (out) (transfer none): pointer to store the stream-id
1476 * Parse a stream-id @event and store the result in the given @stream_id
1477 * location. The string stored in @stream_id must not be modified and will
1478 * remain valid only until @event gets freed. Make a copy if you want to
1479 * modify it or store it for later use.
1482 gst_event_parse_stream_start (GstEvent * event, const gchar ** stream_id)
1484 const GstStructure *structure;
1487 g_return_if_fail (event != NULL);
1488 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STREAM_START);
1490 structure = gst_event_get_structure (event);
1491 val = gst_structure_id_get_value (structure, GST_QUARK (STREAM_ID));
1494 *stream_id = g_value_get_string (val);
1498 * gst_event_set_stream_flags:
1499 * @event: a stream-start event
1500 * @flags: the stream flags to set
1505 gst_event_set_stream_flags (GstEvent * event, GstStreamFlags flags)
1507 g_return_if_fail (event != NULL);
1508 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STREAM_START);
1509 g_return_if_fail (gst_event_is_writable (event));
1511 gst_structure_id_set (GST_EVENT_STRUCTURE (event),
1512 GST_QUARK (FLAGS), GST_TYPE_STREAM_FLAGS, flags, NULL);
1516 * gst_event_parse_stream_flags:
1517 * @event: a stream-start event
1518 * @flags: (out): address of variable where to store the stream flags
1523 gst_event_parse_stream_flags (GstEvent * event, GstStreamFlags * flags)
1525 g_return_if_fail (event != NULL);
1526 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STREAM_START);
1529 gst_structure_id_get (GST_EVENT_STRUCTURE (event),
1530 GST_QUARK (FLAGS), GST_TYPE_STREAM_FLAGS, flags, NULL);
1535 * gst_event_set_group_id:
1536 * @event: a stream-start event
1537 * @group_id: the group id to set
1539 * All streams that have the same group id are supposed to be played
1540 * together, i.e. all streams inside a container file should have the
1541 * same group id but different stream ids. The group id should change
1542 * each time the stream is started, resulting in different group ids
1543 * each time a file is played for example.
1545 * Use gst_util_group_id_next() to get a new group id.
1550 gst_event_set_group_id (GstEvent * event, guint group_id)
1552 g_return_if_fail (event != NULL);
1553 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STREAM_START);
1554 g_return_if_fail (gst_event_is_writable (event));
1556 gst_structure_id_set (GST_EVENT_STRUCTURE (event),
1557 GST_QUARK (GROUP_ID), G_TYPE_UINT, group_id, NULL);
1561 * gst_event_parse_group_id:
1562 * @event: a stream-start event
1563 * @group_id: (out): address of variable where to store the group id
1565 * Returns: %TRUE if a group id was set on the event and could be parsed,
1571 gst_event_parse_group_id (GstEvent * event, guint * group_id)
1573 g_return_val_if_fail (event != NULL, FALSE);
1574 g_return_val_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STREAM_START,
1578 return gst_structure_id_get (GST_EVENT_STRUCTURE (event),
1579 GST_QUARK (GROUP_ID), G_TYPE_UINT, group_id, NULL);
1586 * gst_event_new_toc:
1587 * @toc: (transfer none): #GstToc structure.
1588 * @updated: whether @toc was updated or not.
1590 * Generate a TOC event from the given @toc. The purpose of the TOC event is to
1591 * inform elements that some kind of the TOC was found.
1593 * Returns: (transfer full): a new #GstEvent.
1596 gst_event_new_toc (GstToc * toc, gboolean updated)
1598 GstStructure *toc_struct;
1601 g_return_val_if_fail (toc != NULL, NULL);
1603 GST_CAT_INFO (GST_CAT_EVENT, "creating toc event");
1605 /* need different structure names so sticky_multi event stuff on pads
1606 * works, i.e. both TOC events are kept around */
1607 if (gst_toc_get_scope (toc) == GST_TOC_SCOPE_GLOBAL)
1608 id = GST_QUARK (EVENT_TOC_GLOBAL);
1610 id = GST_QUARK (EVENT_TOC_CURRENT);
1612 toc_struct = gst_structure_new_id (id,
1613 GST_QUARK (TOC), GST_TYPE_TOC, toc,
1614 GST_QUARK (UPDATED), G_TYPE_BOOLEAN, updated, NULL);
1616 return gst_event_new_custom (GST_EVENT_TOC, toc_struct);
1620 * gst_event_parse_toc:
1621 * @event: a TOC event.
1622 * @toc: (out) (transfer full): pointer to #GstToc structure.
1623 * @updated: (out): pointer to store TOC updated flag.
1625 * Parse a TOC @event and store the results in the given @toc and @updated locations.
1628 gst_event_parse_toc (GstEvent * event, GstToc ** toc, gboolean * updated)
1630 const GstStructure *structure;
1632 g_return_if_fail (event != NULL);
1633 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_TOC);
1634 g_return_if_fail (toc != NULL);
1636 structure = gst_event_get_structure (event);
1638 gst_structure_id_get (structure,
1639 GST_QUARK (TOC), GST_TYPE_TOC, toc,
1640 GST_QUARK (UPDATED), G_TYPE_BOOLEAN, updated, NULL);
1644 * gst_event_new_toc_select:
1645 * @uid: UID in the TOC to start playback from.
1647 * Generate a TOC select event with the given @uid. The purpose of the
1648 * TOC select event is to start playback based on the TOC's entry with the
1651 * Returns: a new #GstEvent.
1654 gst_event_new_toc_select (const gchar * uid)
1656 GstStructure *structure;
1658 g_return_val_if_fail (uid != NULL, NULL);
1660 GST_CAT_INFO (GST_CAT_EVENT, "creating toc select event for UID: %s", uid);
1662 structure = gst_structure_new_id (GST_QUARK (EVENT_TOC_SELECT),
1663 GST_QUARK (UID), G_TYPE_STRING, uid, NULL);
1665 return gst_event_new_custom (GST_EVENT_TOC_SELECT, structure);
1669 * gst_event_parse_toc_select:
1670 * @event: a TOC select event.
1671 * @uid: (out): storage for the selection UID.
1673 * Parse a TOC select @event and store the results in the given @uid location.
1676 gst_event_parse_toc_select (GstEvent * event, gchar ** uid)
1678 const GstStructure *structure;
1681 g_return_if_fail (event != NULL);
1682 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_TOC_SELECT);
1684 structure = gst_event_get_structure (event);
1685 val = gst_structure_id_get_value (structure, GST_QUARK (UID));
1688 *uid = g_strdup (g_value_get_string (val));
1693 * gst_event_new_segment_done:
1694 * @format: The format of the position being done
1695 * @position: The position of the segment being done
1697 * Create a new segment-done event. This event is sent by elements that
1698 * finish playback of a segment as a result of a segment seek.
1700 * Returns: (transfer full): a new #GstEvent
1703 gst_event_new_segment_done (GstFormat format, gint64 position)
1706 GstStructure *structure;
1708 GST_CAT_INFO (GST_CAT_EVENT, "creating segment-done event");
1710 structure = gst_structure_new_id (GST_QUARK (EVENT_SEGMENT_DONE),
1711 GST_QUARK (FORMAT), GST_TYPE_FORMAT, format,
1712 GST_QUARK (POSITION), G_TYPE_INT64, position, NULL);
1714 event = gst_event_new_custom (GST_EVENT_SEGMENT_DONE, structure);
1720 * gst_event_parse_segment_done:
1721 * @event: A valid #GstEvent of type GST_EVENT_SEGMENT_DONE.
1722 * @format: (out) (allow-none): Result location for the format, or NULL
1723 * @position: (out) (allow-none): Result location for the position, or NULL
1725 * Extracts the position and format from the segment done message.
1729 gst_event_parse_segment_done (GstEvent * event, GstFormat * format,
1732 const GstStructure *structure;
1735 g_return_if_fail (event != NULL);
1736 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_SEGMENT_DONE);
1738 structure = gst_event_get_structure (event);
1740 val = gst_structure_id_get_value (structure, GST_QUARK (FORMAT));
1742 *format = g_value_get_enum (val);
1744 val = gst_structure_id_get_value (structure, GST_QUARK (POSITION));
1745 if (position != NULL)
1746 *position = g_value_get_int64 (val);