2 * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
3 * 2000 Wim Taymans <wim.taymans@chello.be>
4 * 2005 Wim Taymans <wim@fluendo.com>
6 * gstevent.c: GstEvent subsystem
8 * This library is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Library General Public
10 * License as published by the Free Software Foundation; either
11 * version 2 of the License, or (at your option) any later version.
13 * This library is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Library General Public License for more details.
18 * You should have received a copy of the GNU Library General Public
19 * License along with this library; if not, write to the
20 * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
21 * Boston, MA 02110-1301, USA.
26 * @short_description: Structure describing events that are passed up and down
28 * @see_also: #GstPad, #GstElement
30 * The event class provides factory methods to construct events for sending
31 * and functions to query (parse) received events.
33 * Events are usually created with gst_event_new_*() which takes event-type
34 * specific parameters as arguments.
35 * To send an event application will usually use gst_element_send_event() and
36 * elements will use gst_pad_send_event() or gst_pad_push_event().
37 * The event should be unreffed with gst_event_unref() if it has not been sent.
39 * Events that have been received can be parsed with their respective
40 * gst_event_parse_*() functions. It is valid to pass %NULL for unwanted details.
42 * Events are passed between elements in parallel to the data stream. Some events
43 * are serialized with buffers, others are not. Some events only travel downstream,
44 * others only upstream. Some events can travel both upstream and downstream.
46 * The events are used to signal special conditions in the datastream such as
47 * EOS (end of stream) or the start of a new stream-segment.
48 * Events are also used to flush the pipeline of any pending data.
50 * Most of the event API is used inside plugins. Applications usually only
51 * construct and use seek events.
52 * To do that gst_event_new_seek() is used to create a seek event. It takes
53 * the needed parameters to specify seeking time and mode.
58 * // construct a seek event to play the media from second 2 to 5, flush
59 * // the pipeline to decrease latency.
60 * event = gst_event_new_seek (1.0,
62 * GST_SEEK_FLAG_FLUSH,
63 * GST_SEEK_TYPE_SET, 2 * GST_SECOND,
64 * GST_SEEK_TYPE_SET, 5 * GST_SECOND);
66 * result = gst_element_send_event (pipeline, event);
68 * g_warning ("seek failed");
72 * Last reviewed on 2012-03-28 (0.11.3)
76 #include "gst_private.h"
77 #include <string.h> /* memcpy */
81 #include "gstenumtypes.h"
86 GType _gst_event_type = 0;
92 GstStructure *structure;
95 #define GST_EVENT_STRUCTURE(e) (((GstEventImpl *)(e))->structure)
104 static GstEventQuarks event_quarks[] = {
105 {GST_EVENT_UNKNOWN, "unknown", 0},
106 {GST_EVENT_FLUSH_START, "flush-start", 0},
107 {GST_EVENT_FLUSH_STOP, "flush-stop", 0},
108 {GST_EVENT_STREAM_START, "stream-start", 0},
109 {GST_EVENT_CAPS, "caps", 0},
110 {GST_EVENT_SEGMENT, "segment", 0},
111 {GST_EVENT_TAG, "tag", 0},
112 {GST_EVENT_TOC, "toc", 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;
254 return GST_EVENT_CAST (copy);
258 gst_event_init (GstEventImpl * event, GstEventType type)
260 gst_mini_object_init (GST_MINI_OBJECT_CAST (event), 0, _gst_event_type,
261 (GstMiniObjectCopyFunction) _gst_event_copy, NULL,
262 (GstMiniObjectFreeFunction) _gst_event_free);
264 GST_EVENT_TYPE (event) = type;
265 GST_EVENT_TIMESTAMP (event) = GST_CLOCK_TIME_NONE;
266 GST_EVENT_SEQNUM (event) = gst_util_seqnum_next ();
271 * gst_event_new_custom:
272 * @type: The type of the new event
273 * @structure: (transfer full): the structure for the event. The event will
274 * take ownership of the structure.
276 * Create a new custom-typed event. This can be used for anything not
277 * handled by other event-specific functions to pass an event to another
280 * Make sure to allocate an event type with the #GST_EVENT_MAKE_TYPE macro,
281 * assigning a free number and filling in the correct direction and
282 * serialization flags.
284 * New custom events can also be created by subclassing the event type if
287 * Returns: (transfer full): the new custom event.
290 gst_event_new_custom (GstEventType type, GstStructure * structure)
294 event = g_slice_new0 (GstEventImpl);
296 GST_CAT_DEBUG (GST_CAT_EVENT, "creating new event %p %s %d", event,
297 gst_event_type_get_name (type), type);
300 /* structure must not have a parent */
301 if (!gst_structure_set_parent_refcount (structure,
302 &event->event.mini_object.refcount))
306 gst_event_init (event, type);
308 GST_EVENT_STRUCTURE (event) = structure;
310 return GST_EVENT_CAST (event);
315 g_slice_free1 (sizeof (GstEventImpl), event);
316 g_warning ("structure is already owned by another object");
322 * gst_event_get_structure:
323 * @event: The #GstEvent.
325 * Access the structure of the event.
327 * Returns: The structure of the event. The structure is still
328 * owned by the event, which means that you should not free it and
329 * that the pointer becomes invalid when you free the event.
334 gst_event_get_structure (GstEvent * event)
336 g_return_val_if_fail (GST_IS_EVENT (event), NULL);
338 return GST_EVENT_STRUCTURE (event);
342 * gst_event_writable_structure:
343 * @event: The #GstEvent.
345 * Get a writable version of the structure.
347 * Returns: The structure of the event. The structure is still
348 * owned by the event, which means that you should not free it and
349 * that the pointer becomes invalid when you free the event.
350 * This function checks if @event is writable and will never return NULL.
355 gst_event_writable_structure (GstEvent * event)
357 GstStructure *structure;
359 g_return_val_if_fail (GST_IS_EVENT (event), NULL);
360 g_return_val_if_fail (gst_event_is_writable (event), NULL);
362 structure = GST_EVENT_STRUCTURE (event);
364 if (structure == NULL) {
366 gst_structure_new_id_empty (gst_event_type_to_quark (GST_EVENT_TYPE
368 gst_structure_set_parent_refcount (structure, &event->mini_object.refcount);
369 GST_EVENT_STRUCTURE (event) = structure;
375 * gst_event_has_name:
376 * @event: The #GstEvent.
377 * @name: name to check
379 * Checks if @event has the given @name. This function is usually used to
380 * check the name of a custom event.
382 * Returns: %TRUE if @name matches the name of the event structure.
385 gst_event_has_name (GstEvent * event, const gchar * name)
387 g_return_val_if_fail (GST_IS_EVENT (event), FALSE);
389 if (GST_EVENT_STRUCTURE (event) == NULL)
392 return gst_structure_has_name (GST_EVENT_STRUCTURE (event), name);
396 * gst_event_get_seqnum:
397 * @event: A #GstEvent.
399 * Retrieve the sequence number of a event.
401 * Events have ever-incrementing sequence numbers, which may also be set
402 * explicitly via gst_event_set_seqnum(). Sequence numbers are typically used to
403 * indicate that a event corresponds to some other set of events or messages,
404 * for example an EOS event corresponding to a SEEK event. It is considered good
405 * practice to make this correspondence when possible, though it is not
408 * Note that events and messages share the same sequence number incrementor;
409 * two events or messages will never have the same sequence number unless
410 * that correspondence was made explicitly.
412 * Returns: The event's sequence number.
417 gst_event_get_seqnum (GstEvent * event)
419 g_return_val_if_fail (GST_IS_EVENT (event), -1);
421 return GST_EVENT_SEQNUM (event);
425 * gst_event_set_seqnum:
426 * @event: A #GstEvent.
427 * @seqnum: A sequence number.
429 * Set the sequence number of a event.
431 * This function might be called by the creator of a event to indicate that the
432 * event relates to other events or messages. See gst_event_get_seqnum() for
438 gst_event_set_seqnum (GstEvent * event, guint32 seqnum)
440 g_return_if_fail (GST_IS_EVENT (event));
442 GST_EVENT_SEQNUM (event) = seqnum;
446 * gst_event_new_flush_start:
448 * Allocate a new flush start event. The flush start event can be sent
449 * upstream and downstream and travels out-of-bounds with the dataflow.
451 * It marks pads as being flushing and will make them return
452 * #GST_FLOW_FLUSHING when used for data flow with gst_pad_push(),
453 * gst_pad_chain(), gst_pad_get_range() and gst_pad_pull_range().
454 * Any event (except a #GST_EVENT_FLUSH_STOP) received
455 * on a flushing pad will return %FALSE immediately.
457 * Elements should unlock any blocking functions and exit their streaming
458 * functions as fast as possible when this event is received.
460 * This event is typically generated after a seek to flush out all queued data
461 * in the pipeline so that the new media is played as soon as possible.
463 * Returns: (transfer full): a new flush start event.
466 gst_event_new_flush_start (void)
468 return gst_event_new_custom (GST_EVENT_FLUSH_START, NULL);
472 * gst_event_new_flush_stop:
473 * @reset_time: if time should be reset
475 * Allocate a new flush stop event. The flush stop event can be sent
476 * upstream and downstream and travels serialized with the dataflow.
477 * It is typically sent after sending a FLUSH_START event to make the
478 * pads accept data again.
480 * Elements can process this event synchronized with the dataflow since
481 * the preceding FLUSH_START event stopped the dataflow.
483 * This event is typically generated to complete a seek and to resume
486 * Returns: (transfer full): a new flush stop event.
489 gst_event_new_flush_stop (gboolean reset_time)
493 GST_CAT_INFO (GST_CAT_EVENT, "creating flush stop %d", reset_time);
495 event = gst_event_new_custom (GST_EVENT_FLUSH_STOP,
496 gst_structure_new_id (GST_QUARK (EVENT_FLUSH_STOP),
497 GST_QUARK (RESET_TIME), G_TYPE_BOOLEAN, reset_time, NULL));
503 * gst_event_parse_flush_stop:
504 * @event: The event to parse
505 * @reset_time: (out): if time should be reset
507 * Parse the FLUSH_STOP event and retrieve the @reset_time member.
510 gst_event_parse_flush_stop (GstEvent * event, gboolean * reset_time)
512 GstStructure *structure;
514 g_return_if_fail (GST_IS_EVENT (event));
515 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_FLUSH_STOP);
517 structure = GST_EVENT_STRUCTURE (event);
518 if (G_LIKELY (reset_time))
520 g_value_get_boolean (gst_structure_id_get_value (structure,
521 GST_QUARK (RESET_TIME)));
527 * Create a new EOS event. The eos event can only travel downstream
528 * synchronized with the buffer flow. Elements that receive the EOS
529 * event on a pad can return #GST_FLOW_EOS as a #GstFlowReturn
530 * when data after the EOS event arrives.
532 * The EOS event will travel down to the sink elements in the pipeline
533 * which will then post the #GST_MESSAGE_EOS on the bus after they have
534 * finished playing any buffered data.
536 * When all sinks have posted an EOS message, an EOS message is
537 * forwarded to the application.
539 * The EOS event itself will not cause any state transitions of the pipeline.
541 * Returns: (transfer full): the new EOS event.
544 gst_event_new_eos (void)
546 return gst_event_new_custom (GST_EVENT_EOS, NULL);
551 * @timestamp: the start time (pts) of the gap
552 * @duration: the duration of the gap
554 * Create a new GAP event. A gap event can be thought of as conceptually
555 * equivalent to a buffer to signal that there is no data for a certain
556 * amount of time. This is useful to signal a gap to downstream elements
557 * which may wait for data, such as muxers or mixers or overlays, especially
558 * for sparse streams such as subtitle streams.
560 * Returns: (transfer full): the new GAP event.
563 gst_event_new_gap (GstClockTime timestamp, GstClockTime duration)
567 g_return_val_if_fail (GST_CLOCK_TIME_IS_VALID (timestamp), NULL);
569 GST_CAT_TRACE (GST_CAT_EVENT, "creating gap %" GST_TIME_FORMAT " - "
570 "%" GST_TIME_FORMAT " (duration: %" GST_TIME_FORMAT ")",
571 GST_TIME_ARGS (timestamp), GST_TIME_ARGS (timestamp + duration),
572 GST_TIME_ARGS (duration));
574 event = gst_event_new_custom (GST_EVENT_GAP,
575 gst_structure_new_id (GST_QUARK (EVENT_GAP),
576 GST_QUARK (TIMESTAMP), GST_TYPE_CLOCK_TIME, timestamp,
577 GST_QUARK (DURATION), GST_TYPE_CLOCK_TIME, duration, NULL));
583 * gst_event_parse_gap:
584 * @event: a #GstEvent of type #GST_EVENT_GAP
585 * @timestamp: (out) (allow-none): location where to store the
586 * start time (pts) of the gap, or %NULL
587 * @duration: (out) (allow-none): location where to store the duration of
590 * Extract timestamp and duration from a new GAP event.
593 gst_event_parse_gap (GstEvent * event, GstClockTime * timestamp,
594 GstClockTime * duration)
596 GstStructure *structure;
598 g_return_if_fail (GST_IS_EVENT (event));
599 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_GAP);
601 structure = GST_EVENT_STRUCTURE (event);
602 gst_structure_id_get (structure,
603 GST_QUARK (TIMESTAMP), GST_TYPE_CLOCK_TIME, timestamp,
604 GST_QUARK (DURATION), GST_TYPE_CLOCK_TIME, duration, NULL);
608 * gst_event_new_caps:
609 * @caps: (transfer none): a #GstCaps
611 * Create a new CAPS event for @caps. The caps event can only travel downstream
612 * synchronized with the buffer flow and contains the format of the buffers
613 * that will follow after the event.
615 * Returns: (transfer full): the new CAPS event.
618 gst_event_new_caps (GstCaps * caps)
622 g_return_val_if_fail (caps != NULL, NULL);
623 g_return_val_if_fail (gst_caps_is_fixed (caps), NULL);
625 GST_CAT_INFO (GST_CAT_EVENT, "creating caps event %" GST_PTR_FORMAT, caps);
627 event = gst_event_new_custom (GST_EVENT_CAPS,
628 gst_structure_new_id (GST_QUARK (EVENT_CAPS),
629 GST_QUARK (CAPS), GST_TYPE_CAPS, caps, NULL));
635 * gst_event_parse_caps:
636 * @event: The event to parse
637 * @caps: (out) (transfer none): A pointer to the caps
639 * Get the caps from @event. The caps remains valid as long as @event remains
643 gst_event_parse_caps (GstEvent * event, GstCaps ** caps)
645 GstStructure *structure;
647 g_return_if_fail (GST_IS_EVENT (event));
648 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_CAPS);
650 structure = GST_EVENT_STRUCTURE (event);
653 g_value_get_boxed (gst_structure_id_get_value (structure,
658 * gst_event_new_segment:
659 * @segment: (transfer none): a #GstSegment
661 * Create a new SEGMENT event for @segment. The segment event can only travel
662 * downstream synchronized with the buffer flow and contains timing information
663 * and playback properties for the buffers that will follow.
665 * The newsegment event marks the range of buffers to be processed. All
666 * data not within the segment range is not to be processed. This can be
667 * used intelligently by plugins to apply more efficient methods of skipping
668 * unneeded data. The valid range is expressed with the @start and @stop
671 * The time value of the segment is used in conjunction with the start
672 * value to convert the buffer timestamps into the stream time. This is
673 * usually done in sinks to report the current stream_time.
674 * @time represents the stream_time of a buffer carrying a timestamp of
675 * @start. @time cannot be -1.
677 * @start cannot be -1, @stop can be -1. If there
678 * is a valid @stop given, it must be greater or equal the @start, including
679 * when the indicated playback @rate is < 0.
681 * The @applied_rate value provides information about any rate adjustment that
682 * has already been made to the timestamps and content on the buffers of the
683 * stream. (@rate * @applied_rate) should always equal the rate that has been
684 * requested for playback. For example, if an element has an input segment
685 * with intended playback @rate of 2.0 and applied_rate of 1.0, it can adjust
686 * incoming timestamps and buffer content by half and output a newsegment event
687 * with @rate of 1.0 and @applied_rate of 2.0
689 * After a newsegment event, the buffer stream time is calculated with:
691 * time + (TIMESTAMP(buf) - start) * ABS (rate * applied_rate)
693 * Returns: (transfer full): the new SEGMENT event.
696 gst_event_new_segment (const GstSegment * segment)
700 g_return_val_if_fail (segment != NULL, NULL);
701 g_return_val_if_fail (segment->rate != 0.0, NULL);
702 g_return_val_if_fail (segment->applied_rate != 0.0, NULL);
703 g_return_val_if_fail (segment->format != GST_FORMAT_UNDEFINED, NULL);
705 GST_CAT_INFO (GST_CAT_EVENT, "creating segment event %" GST_SEGMENT_FORMAT,
708 event = gst_event_new_custom (GST_EVENT_SEGMENT,
709 gst_structure_new_id (GST_QUARK (EVENT_SEGMENT),
710 GST_QUARK (SEGMENT), GST_TYPE_SEGMENT, segment, NULL));
716 * gst_event_parse_segment:
717 * @event: The event to parse
718 * @segment: (out) (transfer none): a pointer to a #GstSegment
720 * Parses a segment @event and stores the result in the given @segment location.
721 * @segment remains valid only until the @event is freed. Don't modify the segment
722 * and make a copy if you want to modify it or store it for later use.
725 gst_event_parse_segment (GstEvent * event, const GstSegment ** segment)
727 GstStructure *structure;
729 g_return_if_fail (GST_IS_EVENT (event));
730 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_SEGMENT);
733 structure = GST_EVENT_STRUCTURE (event);
734 *segment = g_value_get_boxed (gst_structure_id_get_value (structure,
735 GST_QUARK (SEGMENT)));
740 * gst_event_copy_segment:
741 * @event: The event to parse
742 * @segment: a pointer to a #GstSegment
744 * Parses a segment @event and copies the #GstSegment into the location
748 gst_event_copy_segment (GstEvent * event, GstSegment * segment)
750 const GstSegment *src;
752 g_return_if_fail (GST_IS_EVENT (event));
753 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_SEGMENT);
756 gst_event_parse_segment (event, &src);
757 gst_segment_copy_into (src, segment);
763 * @taglist: (transfer full): metadata list. The event will take ownership
766 * Generates a metadata tag event from the given @taglist.
768 * The scope of the taglist specifies if the taglist applies to the
769 * complete medium or only to this specific stream. As the tag event
770 * is a sticky event, elements should merge tags received from
771 * upstream with a given scope with their own tags with the same
772 * scope and create a new tag event from it.
774 * Returns: (transfer full): a new #GstEvent
777 gst_event_new_tag (GstTagList * taglist)
780 GValue val = G_VALUE_INIT;
781 const gchar *names[] = { "GstTagList-stream", "GstTagList-global" };
783 g_return_val_if_fail (taglist != NULL, NULL);
785 s = gst_structure_new_empty (names[gst_tag_list_get_scope (taglist)]);
786 g_value_init (&val, GST_TYPE_TAG_LIST);
787 g_value_take_boxed (&val, taglist);
788 gst_structure_id_take_value (s, GST_QUARK (TAGLIST), &val);
789 return gst_event_new_custom (GST_EVENT_TAG, s);
793 * gst_event_parse_tag:
794 * @event: a tag event
795 * @taglist: (out) (transfer none): pointer to metadata list
797 * Parses a tag @event and stores the results in the given @taglist location.
798 * No reference to the taglist will be returned, it remains valid only until
799 * the @event is freed. Don't modify or free the taglist, make a copy if you
800 * want to modify it or store it for later use.
803 gst_event_parse_tag (GstEvent * event, GstTagList ** taglist)
807 g_return_if_fail (GST_IS_EVENT (event));
808 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_TAG);
810 val = gst_structure_id_get_value (GST_EVENT_STRUCTURE (event),
811 GST_QUARK (TAGLIST));
814 *taglist = (GstTagList *) g_value_get_boxed (val);
817 /* buffersize event */
819 * gst_event_new_buffer_size:
820 * @format: buffer format
821 * @minsize: minimum buffer size
822 * @maxsize: maximum buffer size
823 * @async: thread behavior
825 * Create a new buffersize event. The event is sent downstream and notifies
826 * elements that they should provide a buffer of the specified dimensions.
828 * When the @async flag is set, a thread boundary is preferred.
830 * Returns: (transfer full): a new #GstEvent
833 gst_event_new_buffer_size (GstFormat format, gint64 minsize,
834 gint64 maxsize, gboolean async)
837 GstStructure *structure;
839 GST_CAT_INFO (GST_CAT_EVENT,
840 "creating buffersize format %s, minsize %" G_GINT64_FORMAT
841 ", maxsize %" G_GINT64_FORMAT ", async %d", gst_format_get_name (format),
842 minsize, maxsize, async);
844 structure = gst_structure_new_id (GST_QUARK (EVENT_BUFFER_SIZE),
845 GST_QUARK (FORMAT), GST_TYPE_FORMAT, format,
846 GST_QUARK (MINSIZE), G_TYPE_INT64, minsize,
847 GST_QUARK (MAXSIZE), G_TYPE_INT64, maxsize,
848 GST_QUARK (ASYNC), G_TYPE_BOOLEAN, async, NULL);
849 event = gst_event_new_custom (GST_EVENT_BUFFERSIZE, structure);
855 * gst_event_parse_buffer_size:
856 * @event: The event to query
857 * @format: (out): A pointer to store the format in
858 * @minsize: (out): A pointer to store the minsize in
859 * @maxsize: (out): A pointer to store the maxsize in
860 * @async: (out): A pointer to store the async-flag in
862 * Get the format, minsize, maxsize and async-flag in the buffersize event.
865 gst_event_parse_buffer_size (GstEvent * event, GstFormat * format,
866 gint64 * minsize, gint64 * maxsize, gboolean * async)
868 const GstStructure *structure;
870 g_return_if_fail (GST_IS_EVENT (event));
871 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_BUFFERSIZE);
873 structure = GST_EVENT_STRUCTURE (event);
875 *format = (GstFormat)
876 g_value_get_enum (gst_structure_id_get_value (structure,
877 GST_QUARK (FORMAT)));
880 g_value_get_int64 (gst_structure_id_get_value (structure,
881 GST_QUARK (MINSIZE)));
884 g_value_get_int64 (gst_structure_id_get_value (structure,
885 GST_QUARK (MAXSIZE)));
888 g_value_get_boolean (gst_structure_id_get_value (structure,
894 * @type: the QoS type
895 * @proportion: the proportion of the qos message
896 * @diff: The time difference of the last Clock sync
897 * @timestamp: The timestamp of the buffer
899 * Allocate a new qos event with the given values.
900 * The QOS event is generated in an element that wants an upstream
901 * element to either reduce or increase its rate because of
902 * high/low CPU load or other resource usage such as network performance or
903 * throttling. Typically sinks generate these events for each buffer
906 * @type indicates the reason for the QoS event. #GST_QOS_TYPE_OVERFLOW is
907 * used when a buffer arrived in time or when the sink cannot keep up with
908 * the upstream datarate. #GST_QOS_TYPE_UNDERFLOW is when the sink is not
909 * receiving buffers fast enough and thus has to drop late buffers.
910 * #GST_QOS_TYPE_THROTTLE is used when the datarate is artificially limited
911 * by the application, for example to reduce power consumption.
913 * @proportion indicates the real-time performance of the streaming in the
914 * element that generated the QoS event (usually the sink). The value is
915 * generally computed based on more long term statistics about the streams
916 * timestamps compared to the clock.
917 * A value < 1.0 indicates that the upstream element is producing data faster
918 * than real-time. A value > 1.0 indicates that the upstream element is not
919 * producing data fast enough. 1.0 is the ideal @proportion value. The
920 * proportion value can safely be used to lower or increase the quality of
923 * @diff is the difference against the clock in running time of the last
924 * buffer that caused the element to generate the QOS event. A negative value
925 * means that the buffer with @timestamp arrived in time. A positive value
926 * indicates how late the buffer with @timestamp was. When throttling is
927 * enabled, @diff will be set to the requested throttling interval.
929 * @timestamp is the timestamp of the last buffer that cause the element
930 * to generate the QOS event. It is expressed in running time and thus an ever
933 * The upstream element can use the @diff and @timestamp values to decide
934 * whether to process more buffers. For positive @diff, all buffers with
935 * timestamp <= @timestamp + @diff will certainly arrive late in the sink
936 * as well. A (negative) @diff value so that @timestamp + @diff would yield a
937 * result smaller than 0 is not allowed.
939 * The application can use general event probes to intercept the QoS
940 * event and implement custom application specific QoS handling.
942 * Returns: (transfer full): a new QOS event.
945 gst_event_new_qos (GstQOSType type, gdouble proportion,
946 GstClockTimeDiff diff, GstClockTime timestamp)
949 GstStructure *structure;
951 /* diff must be positive or timestamp + diff must be positive */
952 g_return_val_if_fail (diff >= 0 || -diff <= timestamp, NULL);
954 GST_CAT_LOG (GST_CAT_EVENT,
955 "creating qos type %d, proportion %lf, diff %" G_GINT64_FORMAT
956 ", timestamp %" GST_TIME_FORMAT, type, proportion,
957 diff, GST_TIME_ARGS (timestamp));
959 structure = gst_structure_new_id (GST_QUARK (EVENT_QOS),
960 GST_QUARK (TYPE), GST_TYPE_QOS_TYPE, type,
961 GST_QUARK (PROPORTION), G_TYPE_DOUBLE, proportion,
962 GST_QUARK (DIFF), G_TYPE_INT64, diff,
963 GST_QUARK (TIMESTAMP), G_TYPE_UINT64, timestamp, NULL);
964 event = gst_event_new_custom (GST_EVENT_QOS, structure);
970 * gst_event_parse_qos:
971 * @event: The event to query
972 * @type: (out): A pointer to store the QoS type in
973 * @proportion: (out): A pointer to store the proportion in
974 * @diff: (out): A pointer to store the diff in
975 * @timestamp: (out): A pointer to store the timestamp in
977 * Get the type, proportion, diff and timestamp in the qos event. See
978 * gst_event_new_qos() for more information about the different QoS values.
981 gst_event_parse_qos (GstEvent * event, GstQOSType * type,
982 gdouble * proportion, GstClockTimeDiff * diff, GstClockTime * timestamp)
984 const GstStructure *structure;
986 g_return_if_fail (GST_IS_EVENT (event));
987 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_QOS);
989 structure = GST_EVENT_STRUCTURE (event);
992 g_value_get_enum (gst_structure_id_get_value (structure,
996 g_value_get_double (gst_structure_id_get_value (structure,
997 GST_QUARK (PROPORTION)));
1000 g_value_get_int64 (gst_structure_id_get_value (structure,
1004 g_value_get_uint64 (gst_structure_id_get_value (structure,
1005 GST_QUARK (TIMESTAMP)));
1009 * gst_event_new_seek:
1010 * @rate: The new playback rate
1011 * @format: The format of the seek values
1012 * @flags: The optional seek flags
1013 * @start_type: The type and flags for the new start position
1014 * @start: The value of the new start position
1015 * @stop_type: The type and flags for the new stop position
1016 * @stop: The value of the new stop position
1018 * Allocate a new seek event with the given parameters.
1020 * The seek event configures playback of the pipeline between @start to @stop
1021 * at the speed given in @rate, also called a playback segment.
1022 * The @start and @stop values are expressed in @format.
1024 * A @rate of 1.0 means normal playback rate, 2.0 means double speed.
1025 * Negatives values means backwards playback. A value of 0.0 for the
1026 * rate is not allowed and should be accomplished instead by PAUSING the
1029 * A pipeline has a default playback segment configured with a start
1030 * position of 0, a stop position of -1 and a rate of 1.0. The currently
1031 * configured playback segment can be queried with #GST_QUERY_SEGMENT.
1033 * @start_type and @stop_type specify how to adjust the currently configured
1034 * start and stop fields in playback segment. Adjustments can be made relative
1035 * or absolute to the last configured values. A type of #GST_SEEK_TYPE_NONE
1036 * means that the position should not be updated.
1038 * When the rate is positive and @start has been updated, playback will start
1039 * from the newly configured start position.
1041 * For negative rates, playback will start from the newly configured stop
1042 * position (if any). If the stop position is updated, it must be different from
1043 * -1 (#GST_CLOCK_TIME_NONE) for negative rates.
1045 * It is not possible to seek relative to the current playback position, to do
1046 * this, PAUSE the pipeline, query the current playback position with
1047 * #GST_QUERY_POSITION and update the playback segment current position with a
1048 * #GST_SEEK_TYPE_SET to the desired position.
1050 * Returns: (transfer full): a new seek event.
1053 gst_event_new_seek (gdouble rate, GstFormat format, GstSeekFlags flags,
1054 GstSeekType start_type, gint64 start, GstSeekType stop_type, gint64 stop)
1057 GstStructure *structure;
1059 g_return_val_if_fail (rate != 0.0, NULL);
1061 if (format == GST_FORMAT_TIME) {
1062 GST_CAT_INFO (GST_CAT_EVENT,
1063 "creating seek rate %lf, format TIME, flags %d, "
1064 "start_type %d, start %" GST_TIME_FORMAT ", "
1065 "stop_type %d, stop %" GST_TIME_FORMAT,
1066 rate, flags, start_type, GST_TIME_ARGS (start),
1067 stop_type, GST_TIME_ARGS (stop));
1069 GST_CAT_INFO (GST_CAT_EVENT,
1070 "creating seek rate %lf, format %s, flags %d, "
1071 "start_type %d, start %" G_GINT64_FORMAT ", "
1072 "stop_type %d, stop %" G_GINT64_FORMAT,
1073 rate, gst_format_get_name (format), flags, start_type, start, stop_type,
1077 structure = gst_structure_new_id (GST_QUARK (EVENT_SEEK),
1078 GST_QUARK (RATE), G_TYPE_DOUBLE, rate,
1079 GST_QUARK (FORMAT), GST_TYPE_FORMAT, format,
1080 GST_QUARK (FLAGS), GST_TYPE_SEEK_FLAGS, flags,
1081 GST_QUARK (CUR_TYPE), GST_TYPE_SEEK_TYPE, start_type,
1082 GST_QUARK (CUR), G_TYPE_INT64, start,
1083 GST_QUARK (STOP_TYPE), GST_TYPE_SEEK_TYPE, stop_type,
1084 GST_QUARK (STOP), G_TYPE_INT64, stop, NULL);
1085 event = gst_event_new_custom (GST_EVENT_SEEK, structure);
1091 * gst_event_parse_seek:
1092 * @event: a seek event
1093 * @rate: (out): result location for the rate
1094 * @format: (out): result location for the stream format
1095 * @flags: (out): result location for the #GstSeekFlags
1096 * @start_type: (out): result location for the #GstSeekType of the start position
1097 * @start: (out): result location for the start position expressed in @format
1098 * @stop_type: (out): result location for the #GstSeekType of the stop position
1099 * @stop: (out): result location for the stop position expressed in @format
1101 * Parses a seek @event and stores the results in the given result locations.
1104 gst_event_parse_seek (GstEvent * event, gdouble * rate,
1105 GstFormat * format, GstSeekFlags * flags, GstSeekType * start_type,
1106 gint64 * start, GstSeekType * stop_type, gint64 * stop)
1108 const GstStructure *structure;
1110 g_return_if_fail (GST_IS_EVENT (event));
1111 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_SEEK);
1113 structure = GST_EVENT_STRUCTURE (event);
1116 g_value_get_double (gst_structure_id_get_value (structure,
1119 *format = (GstFormat)
1120 g_value_get_enum (gst_structure_id_get_value (structure,
1121 GST_QUARK (FORMAT)));
1123 *flags = (GstSeekFlags)
1124 g_value_get_flags (gst_structure_id_get_value (structure,
1125 GST_QUARK (FLAGS)));
1127 *start_type = (GstSeekType)
1128 g_value_get_enum (gst_structure_id_get_value (structure,
1129 GST_QUARK (CUR_TYPE)));
1132 g_value_get_int64 (gst_structure_id_get_value (structure,
1135 *stop_type = (GstSeekType)
1136 g_value_get_enum (gst_structure_id_get_value (structure,
1137 GST_QUARK (STOP_TYPE)));
1140 g_value_get_int64 (gst_structure_id_get_value (structure,
1145 * gst_event_new_navigation:
1146 * @structure: (transfer full): description of the event. The event will take
1147 * ownership of the structure.
1149 * Create a new navigation event from the given description.
1151 * Returns: (transfer full): a new #GstEvent
1154 gst_event_new_navigation (GstStructure * structure)
1156 g_return_val_if_fail (structure != NULL, NULL);
1158 return gst_event_new_custom (GST_EVENT_NAVIGATION, structure);
1162 * gst_event_new_latency:
1163 * @latency: the new latency value
1165 * Create a new latency event. The event is sent upstream from the sinks and
1166 * notifies elements that they should add an additional @latency to the
1167 * running time before synchronising against the clock.
1169 * The latency is mostly used in live sinks and is always expressed in
1172 * Returns: (transfer full): a new #GstEvent
1175 gst_event_new_latency (GstClockTime latency)
1178 GstStructure *structure;
1180 GST_CAT_INFO (GST_CAT_EVENT,
1181 "creating latency event %" GST_TIME_FORMAT, GST_TIME_ARGS (latency));
1183 structure = gst_structure_new_id (GST_QUARK (EVENT_LATENCY),
1184 GST_QUARK (LATENCY), G_TYPE_UINT64, latency, NULL);
1185 event = gst_event_new_custom (GST_EVENT_LATENCY, structure);
1191 * gst_event_parse_latency:
1192 * @event: The event to query
1193 * @latency: (out): A pointer to store the latency in.
1195 * Get the latency in the latency event.
1198 gst_event_parse_latency (GstEvent * event, GstClockTime * latency)
1200 g_return_if_fail (GST_IS_EVENT (event));
1201 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_LATENCY);
1205 g_value_get_uint64 (gst_structure_id_get_value (GST_EVENT_STRUCTURE
1206 (event), GST_QUARK (LATENCY)));
1210 * gst_event_new_step:
1211 * @format: the format of @amount
1212 * @amount: the amount of data to step
1213 * @rate: the step rate
1214 * @flush: flushing steps
1215 * @intermediate: intermediate steps
1217 * Create a new step event. The purpose of the step event is to instruct a sink
1218 * to skip @amount (expressed in @format) of media. It can be used to implement
1219 * stepping through the video frame by frame or for doing fast trick modes.
1221 * A rate of <= 0.0 is not allowed. Pause the pipeline, for the effect of rate
1222 * = 0.0 or first reverse the direction of playback using a seek event to get
1223 * the same effect as rate < 0.0.
1225 * The @flush flag will clear any pending data in the pipeline before starting
1226 * the step operation.
1228 * The @intermediate flag instructs the pipeline that this step operation is
1229 * part of a larger step operation.
1231 * Returns: (transfer full): a new #GstEvent
1234 gst_event_new_step (GstFormat format, guint64 amount, gdouble rate,
1235 gboolean flush, gboolean intermediate)
1238 GstStructure *structure;
1240 g_return_val_if_fail (rate > 0.0, NULL);
1242 GST_CAT_INFO (GST_CAT_EVENT, "creating step event");
1244 structure = gst_structure_new_id (GST_QUARK (EVENT_STEP),
1245 GST_QUARK (FORMAT), GST_TYPE_FORMAT, format,
1246 GST_QUARK (AMOUNT), G_TYPE_UINT64, amount,
1247 GST_QUARK (RATE), G_TYPE_DOUBLE, rate,
1248 GST_QUARK (FLUSH), G_TYPE_BOOLEAN, flush,
1249 GST_QUARK (INTERMEDIATE), G_TYPE_BOOLEAN, intermediate, NULL);
1250 event = gst_event_new_custom (GST_EVENT_STEP, structure);
1256 * gst_event_parse_step:
1257 * @event: The event to query
1258 * @format: (out) (allow-none): a pointer to store the format in
1259 * @amount: (out) (allow-none): a pointer to store the amount in
1260 * @rate: (out) (allow-none): a pointer to store the rate in
1261 * @flush: (out) (allow-none): a pointer to store the flush boolean in
1262 * @intermediate: (out) (allow-none): a pointer to store the intermediate
1265 * Parse the step event.
1268 gst_event_parse_step (GstEvent * event, GstFormat * format, guint64 * amount,
1269 gdouble * rate, gboolean * flush, gboolean * intermediate)
1271 const GstStructure *structure;
1273 g_return_if_fail (GST_IS_EVENT (event));
1274 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STEP);
1276 structure = GST_EVENT_STRUCTURE (event);
1279 (GstFormat) g_value_get_enum (gst_structure_id_get_value (structure,
1280 GST_QUARK (FORMAT)));
1282 *amount = g_value_get_uint64 (gst_structure_id_get_value (structure,
1283 GST_QUARK (AMOUNT)));
1285 *rate = g_value_get_double (gst_structure_id_get_value (structure,
1288 *flush = g_value_get_boolean (gst_structure_id_get_value (structure,
1289 GST_QUARK (FLUSH)));
1291 *intermediate = g_value_get_boolean (gst_structure_id_get_value (structure,
1292 GST_QUARK (INTERMEDIATE)));
1296 * gst_event_new_reconfigure:
1298 * Create a new reconfigure event. The purpose of the reconfigure event is
1299 * to travel upstream and make elements renegotiate their caps or reconfigure
1300 * their buffer pools. This is useful when changing properties on elements
1301 * or changing the topology of the pipeline.
1303 * Returns: (transfer full): a new #GstEvent
1306 gst_event_new_reconfigure (void)
1310 GST_CAT_INFO (GST_CAT_EVENT, "creating reconfigure event");
1312 event = gst_event_new_custom (GST_EVENT_RECONFIGURE, NULL);
1318 * gst_event_new_sink_message:
1319 * @name: a name for the event
1320 * @msg: (transfer none): the #GstMessage to be posted
1322 * Create a new sink-message event. The purpose of the sink-message event is
1323 * to instruct a sink to post the message contained in the event synchronized
1326 * @name is used to store multiple sticky events on one pad.
1328 * Returns: (transfer full): a new #GstEvent
1330 /* FIXME 0.11: take ownership of msg for consistency? */
1332 gst_event_new_sink_message (const gchar * name, GstMessage * msg)
1335 GstStructure *structure;
1337 g_return_val_if_fail (msg != NULL, NULL);
1339 GST_CAT_INFO (GST_CAT_EVENT, "creating sink-message event");
1341 structure = gst_structure_new_id (g_quark_from_string (name),
1342 GST_QUARK (MESSAGE), GST_TYPE_MESSAGE, msg, NULL);
1343 event = gst_event_new_custom (GST_EVENT_SINK_MESSAGE, structure);
1349 * gst_event_parse_sink_message:
1350 * @event: The event to query
1351 * @msg: (out) (transfer full): a pointer to store the #GstMessage in.
1353 * Parse the sink-message event. Unref @msg after usage.
1356 gst_event_parse_sink_message (GstEvent * event, GstMessage ** msg)
1358 const GstStructure *structure;
1360 g_return_if_fail (GST_IS_EVENT (event));
1361 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_SINK_MESSAGE);
1363 structure = GST_EVENT_STRUCTURE (event);
1366 GST_MESSAGE (g_value_dup_boxed (gst_structure_id_get_value
1367 (structure, GST_QUARK (MESSAGE))));
1371 * gst_event_new_stream_start:
1372 * @stream_id: Identifier for this stream
1374 * Create a new STREAM_START event. The stream start event can only
1375 * travel downstream synchronized with the buffer flow. It is expected
1376 * to be the first event that is sent for a new stream.
1378 * Source elements, demuxers and other elements that create new streams
1379 * are supposed to send this event as the first event of a new stream. It
1380 * should not be send after a flushing seek or in similar situations
1381 * and is used to mark the beginning of a new logical stream. Elements
1382 * combining multiple streams must ensure that this event is only forwarded
1383 * downstream once and not for every single input stream.
1385 * The @stream_id should be a unique string that consists of the upstream
1386 * stream-id, / as separator and a unique stream-id for this specific
1387 * stream. A new stream-id should only be created for a stream if the upstream
1388 * stream is split into (potentially) multiple new streams, e.g. in a demuxer,
1389 * but not for every single element in the pipeline.
1390 * gst_pad_create_stream_id() or gst_pad_create_stream_id_printf() can be
1391 * used to create a stream-id.
1393 * Returns: (transfer full): the new STREAM_START event.
1396 gst_event_new_stream_start (const gchar * stream_id)
1400 g_return_val_if_fail (stream_id != NULL, NULL);
1402 s = gst_structure_new_id (GST_QUARK (EVENT_STREAM_START),
1403 GST_QUARK (STREAM_ID), G_TYPE_STRING, stream_id,
1404 GST_QUARK (FLAGS), GST_TYPE_STREAM_FLAGS, GST_STREAM_FLAG_NONE, NULL);
1406 return gst_event_new_custom (GST_EVENT_STREAM_START, s);
1410 * gst_event_parse_stream_start:
1411 * @event: a stream-start event.
1412 * @stream_id: (out) (transfer none): pointer to store the stream-id
1414 * Parse a stream-id @event and store the result in the given @stream_id
1415 * location. The string stored in @stream_id must not be modified and will
1416 * remain valid only until @event gets freed. Make a copy if you want to
1417 * modify it or store it for later use.
1420 gst_event_parse_stream_start (GstEvent * event, const gchar ** stream_id)
1422 const GstStructure *structure;
1425 g_return_if_fail (event != NULL);
1426 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STREAM_START);
1428 structure = gst_event_get_structure (event);
1429 val = gst_structure_id_get_value (structure, GST_QUARK (STREAM_ID));
1432 *stream_id = g_value_get_string (val);
1436 * gst_event_set_stream_flags:
1437 * @event: a stream-start event
1438 * @flags: the stream flags to set
1443 gst_event_set_stream_flags (GstEvent * event, GstStreamFlags flags)
1445 g_return_if_fail (event != NULL);
1446 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STREAM_START);
1447 g_return_if_fail (gst_event_is_writable (event));
1449 gst_structure_id_set (GST_EVENT_STRUCTURE (event),
1450 GST_QUARK (FLAGS), GST_TYPE_STREAM_FLAGS, flags, NULL);
1454 * gst_event_parse_stream_flags:
1455 * @event: a stream-start event
1456 * @flags: (out): address of variable where to store the stream flags
1461 gst_event_parse_stream_flags (GstEvent * event, GstStreamFlags * flags)
1463 g_return_if_fail (event != NULL);
1464 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STREAM_START);
1467 gst_structure_id_get (GST_EVENT_STRUCTURE (event),
1468 GST_QUARK (FLAGS), GST_TYPE_STREAM_FLAGS, flags, NULL);
1473 * gst_event_set_group_id:
1474 * @event: a stream-start event
1475 * @group_id: the group id to set
1477 * All streams that have the same group id are supposed to be played
1478 * together, i.e. all streams inside a container file should have the
1479 * same group id but different stream ids. The group id should change
1480 * each time the stream is started, resulting in different group ids
1481 * each time a file is played for example.
1483 * Use gst_util_group_id_next() to get a new group id.
1488 gst_event_set_group_id (GstEvent * event, guint group_id)
1490 g_return_if_fail (event != NULL);
1491 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STREAM_START);
1492 g_return_if_fail (gst_event_is_writable (event));
1494 gst_structure_id_set (GST_EVENT_STRUCTURE (event),
1495 GST_QUARK (GROUP_ID), G_TYPE_UINT, group_id, NULL);
1499 * gst_event_parse_group_id:
1500 * @event: a stream-start event
1501 * @group_id: (out): address of variable where to store the group id
1503 * Returns: %TRUE if a group id was set on the event and could be parsed,
1509 gst_event_parse_group_id (GstEvent * event, guint * group_id)
1511 g_return_val_if_fail (event != NULL, FALSE);
1512 g_return_val_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STREAM_START,
1516 return gst_structure_id_get (GST_EVENT_STRUCTURE (event),
1517 GST_QUARK (GROUP_ID), G_TYPE_UINT, group_id, NULL);
1524 * gst_event_new_toc:
1525 * @toc: (transfer none): #GstToc structure.
1526 * @updated: whether @toc was updated or not.
1528 * Generate a TOC event from the given @toc. The purpose of the TOC event is to
1529 * inform elements that some kind of the TOC was found.
1531 * Returns: (transfer full): a new #GstEvent.
1534 gst_event_new_toc (GstToc * toc, gboolean updated)
1536 GstStructure *toc_struct;
1539 g_return_val_if_fail (toc != NULL, NULL);
1541 GST_CAT_INFO (GST_CAT_EVENT, "creating toc event");
1543 /* need different structure names so sticky_multi event stuff on pads
1544 * works, i.e. both TOC events are kept around */
1545 if (gst_toc_get_scope (toc) == GST_TOC_SCOPE_GLOBAL)
1546 id = GST_QUARK (EVENT_TOC_GLOBAL);
1548 id = GST_QUARK (EVENT_TOC_CURRENT);
1550 toc_struct = gst_structure_new_id (id,
1551 GST_QUARK (TOC), GST_TYPE_TOC, toc,
1552 GST_QUARK (UPDATED), G_TYPE_BOOLEAN, updated, NULL);
1554 return gst_event_new_custom (GST_EVENT_TOC, toc_struct);
1558 * gst_event_parse_toc:
1559 * @event: a TOC event.
1560 * @toc: (out) (transfer full): pointer to #GstToc structure.
1561 * @updated: (out): pointer to store TOC updated flag.
1563 * Parse a TOC @event and store the results in the given @toc and @updated locations.
1566 gst_event_parse_toc (GstEvent * event, GstToc ** toc, gboolean * updated)
1568 const GstStructure *structure;
1570 g_return_if_fail (event != NULL);
1571 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_TOC);
1572 g_return_if_fail (toc != NULL);
1574 structure = gst_event_get_structure (event);
1576 gst_structure_id_get (structure,
1577 GST_QUARK (TOC), GST_TYPE_TOC, toc,
1578 GST_QUARK (UPDATED), G_TYPE_BOOLEAN, updated, NULL);
1582 * gst_event_new_toc_select:
1583 * @uid: UID in the TOC to start playback from.
1585 * Generate a TOC select event with the given @uid. The purpose of the
1586 * TOC select event is to start playback based on the TOC's entry with the
1589 * Returns: a new #GstEvent.
1592 gst_event_new_toc_select (const gchar * uid)
1594 GstStructure *structure;
1596 g_return_val_if_fail (uid != NULL, NULL);
1598 GST_CAT_INFO (GST_CAT_EVENT, "creating toc select event for UID: %s", uid);
1600 structure = gst_structure_new_id (GST_QUARK (EVENT_TOC_SELECT),
1601 GST_QUARK (UID), G_TYPE_STRING, uid, NULL);
1603 return gst_event_new_custom (GST_EVENT_TOC_SELECT, structure);
1607 * gst_event_parse_toc_select:
1608 * @event: a TOC select event.
1609 * @uid: (out): storage for the selection UID.
1611 * Parse a TOC select @event and store the results in the given @uid location.
1614 gst_event_parse_toc_select (GstEvent * event, gchar ** uid)
1616 const GstStructure *structure;
1619 g_return_if_fail (event != NULL);
1620 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_TOC_SELECT);
1622 structure = gst_event_get_structure (event);
1623 val = gst_structure_id_get_value (structure, GST_QUARK (UID));
1626 *uid = g_strdup (g_value_get_string (val));
1631 * gst_event_new_segment_done:
1632 * @format: The format of the position being done
1633 * @position: The position of the segment being done
1635 * Create a new segment-done event. This event is sent by elements that
1636 * finish playback of a segment as a result of a segment seek.
1638 * Returns: (transfer full): a new #GstEvent
1641 gst_event_new_segment_done (GstFormat format, gint64 position)
1644 GstStructure *structure;
1646 GST_CAT_INFO (GST_CAT_EVENT, "creating segment-done event");
1648 structure = gst_structure_new_id (GST_QUARK (EVENT_SEGMENT_DONE),
1649 GST_QUARK (FORMAT), GST_TYPE_FORMAT, format,
1650 GST_QUARK (POSITION), G_TYPE_INT64, position, NULL);
1652 event = gst_event_new_custom (GST_EVENT_SEGMENT_DONE, structure);
1658 * gst_event_parse_segment_done:
1659 * @event: A valid #GstEvent of type GST_EVENT_SEGMENT_DONE.
1660 * @format: (out) (allow-none): Result location for the format, or NULL
1661 * @position: (out) (allow-none): Result location for the position, or NULL
1663 * Extracts the position and format from the segment done message.
1667 gst_event_parse_segment_done (GstEvent * event, GstFormat * format,
1670 const GstStructure *structure;
1673 g_return_if_fail (event != NULL);
1674 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_SEGMENT_DONE);
1676 structure = gst_event_get_structure (event);
1678 val = gst_structure_id_get_value (structure, GST_QUARK (FORMAT));
1680 *format = g_value_get_enum (val);
1682 val = gst_structure_id_get_value (structure, GST_QUARK (POSITION));
1683 if (position != NULL)
1684 *position = g_value_get_int64 (val);