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.
27 * @short_description: Structure describing events that are passed up and down
29 * @see_also: #GstPad, #GstElement
31 * The event class provides factory methods to construct events for sending
32 * and functions to query (parse) received events.
34 * Events are usually created with gst_event_new_*() which takes event-type
35 * specific parameters as arguments.
36 * To send an event application will usually use gst_element_send_event() and
37 * elements will use gst_pad_send_event() or gst_pad_push_event().
38 * The event should be unreffed with gst_event_unref() if it has not been sent.
40 * Events that have been received can be parsed with their respective
41 * gst_event_parse_*() functions. It is valid to pass %NULL for unwanted details.
43 * Events are passed between elements in parallel to the data stream. Some events
44 * are serialized with buffers, others are not. Some events only travel downstream,
45 * others only upstream. Some events can travel both upstream and downstream.
47 * The events are used to signal special conditions in the datastream such as
48 * EOS (end of stream) or the start of a new stream-segment.
49 * Events are also used to flush the pipeline of any pending data.
51 * Most of the event API is used inside plugins. Applications usually only
52 * construct and use seek events.
53 * To do that gst_event_new_seek() is used to create a seek event. It takes
54 * the needed parameters to specify seeking time and mode.
55 * |[<!-- language="C" -->
59 * // construct a seek event to play the media from second 2 to 5, flush
60 * // the pipeline to decrease latency.
61 * event = gst_event_new_seek (1.0,
63 * GST_SEEK_FLAG_FLUSH,
64 * GST_SEEK_TYPE_SET, 2 * GST_SECOND,
65 * GST_SEEK_TYPE_SET, 5 * GST_SECOND);
67 * result = gst_element_send_event (pipeline, event);
69 * g_warning ("seek failed");
74 #define GST_DISABLE_MINIOBJECT_INLINE_FUNCTIONS
75 #include "gst_private.h"
76 #include <string.h> /* memcpy */
80 #include "gstenumtypes.h"
85 GType _gst_event_type = 0;
91 GstStructure *structure;
92 gint64 running_time_offset;
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_SELECT_STREAMS, "select-streams", 0},
109 {GST_EVENT_STREAM_START, "stream-start", 0},
110 {GST_EVENT_STREAM_COLLECTION, "stream-collection", 0},
111 {GST_EVENT_CAPS, "caps", 0},
112 {GST_EVENT_SEGMENT, "segment", 0},
113 {GST_EVENT_TAG, "tag", 0},
114 {GST_EVENT_TOC, "toc", 0},
115 {GST_EVENT_PROTECTION, "protection", 0},
116 {GST_EVENT_BUFFERSIZE, "buffersize", 0},
117 {GST_EVENT_SINK_MESSAGE, "sink-message", 0},
118 {GST_EVENT_EOS, "eos", 0},
119 {GST_EVENT_SEGMENT_DONE, "segment-done", 0},
120 {GST_EVENT_GAP, "gap", 0},
121 {GST_EVENT_QOS, "qos", 0},
122 {GST_EVENT_SEEK, "seek", 0},
123 {GST_EVENT_NAVIGATION, "navigation", 0},
124 {GST_EVENT_LATENCY, "latency", 0},
125 {GST_EVENT_STEP, "step", 0},
126 {GST_EVENT_RECONFIGURE, "reconfigure", 0},
127 {GST_EVENT_TOC_SELECT, "toc-select", 0},
128 {GST_EVENT_CUSTOM_UPSTREAM, "custom-upstream", 0},
129 {GST_EVENT_CUSTOM_DOWNSTREAM, "custom-downstream", 0},
130 {GST_EVENT_CUSTOM_DOWNSTREAM_OOB, "custom-downstream-oob", 0},
131 {GST_EVENT_CUSTOM_DOWNSTREAM_STICKY, "custom-downstream-sticky", 0},
132 {GST_EVENT_CUSTOM_BOTH, "custom-both", 0},
133 {GST_EVENT_CUSTOM_BOTH_OOB, "custom-both-oob", 0},
134 {GST_EVENT_STREAM_GROUP_DONE, "stream-group-done", 0},
135 {GST_EVENT_INSTANT_RATE_CHANGE, "instant-rate-change", 0},
136 {GST_EVENT_INSTANT_RATE_SYNC_TIME, "instant-rate-sync-time", 0},
141 GST_DEFINE_MINI_OBJECT_TYPE (GstEvent, gst_event);
144 _priv_gst_event_initialize (void)
148 _gst_event_type = gst_event_get_type ();
150 g_type_class_ref (gst_seek_flags_get_type ());
151 g_type_class_ref (gst_seek_type_get_type ());
153 for (i = 0; event_quarks[i].name; i++) {
154 event_quarks[i].quark = g_quark_from_static_string (event_quarks[i].name);
159 * gst_event_type_get_name:
160 * @type: the event type
162 * Get a printable name for the given event type. Do not modify or free.
164 * Returns: a reference to the static name of the event.
167 gst_event_type_get_name (GstEventType type)
171 for (i = 0; event_quarks[i].name; i++) {
172 if (type == event_quarks[i].type)
173 return event_quarks[i].name;
179 * gst_event_type_to_quark:
180 * @type: the event type
182 * Get the unique quark for the given event type.
184 * Returns: the quark associated with the event type
187 gst_event_type_to_quark (GstEventType type)
191 for (i = 0; event_quarks[i].name; i++) {
192 if (type == event_quarks[i].type)
193 return event_quarks[i].quark;
199 * gst_event_type_get_flags:
200 * @type: a #GstEventType
202 * Gets the #GstEventTypeFlags associated with @type.
204 * Returns: a #GstEventTypeFlags.
207 gst_event_type_get_flags (GstEventType type)
209 GstEventTypeFlags ret;
211 ret = type & ((1 << GST_EVENT_NUM_SHIFT) - 1);
217 _gst_event_free (GstEvent * event)
221 g_return_if_fail (event != NULL);
222 g_return_if_fail (GST_IS_EVENT (event));
224 GST_CAT_LOG (GST_CAT_EVENT, "freeing event %p type %s", event,
225 GST_EVENT_TYPE_NAME (event));
227 s = GST_EVENT_STRUCTURE (event);
230 gst_structure_set_parent_refcount (s, NULL);
231 gst_structure_free (s);
234 memset (event, 0xff, sizeof (GstEventImpl));
237 g_slice_free1 (sizeof (GstEventImpl), event);
240 static void gst_event_init (GstEventImpl * event, GstEventType type);
243 _gst_event_copy (GstEvent * event)
248 copy = g_slice_new0 (GstEventImpl);
250 gst_event_init (copy, GST_EVENT_TYPE (event));
252 GST_EVENT_TIMESTAMP (copy) = GST_EVENT_TIMESTAMP (event);
253 GST_EVENT_SEQNUM (copy) = GST_EVENT_SEQNUM (event);
255 s = GST_EVENT_STRUCTURE (event);
257 GST_EVENT_STRUCTURE (copy) = gst_structure_copy (s);
258 gst_structure_set_parent_refcount (GST_EVENT_STRUCTURE (copy),
259 ©->event.mini_object.refcount);
261 GST_EVENT_STRUCTURE (copy) = NULL;
264 ((GstEventImpl *) copy)->running_time_offset =
265 ((GstEventImpl *) event)->running_time_offset;
267 return GST_EVENT_CAST (copy);
271 gst_event_init (GstEventImpl * event, GstEventType type)
273 gst_mini_object_init (GST_MINI_OBJECT_CAST (event), 0, _gst_event_type,
274 (GstMiniObjectCopyFunction) _gst_event_copy, NULL,
275 (GstMiniObjectFreeFunction) _gst_event_free);
277 GST_EVENT_TYPE (event) = type;
278 GST_EVENT_TIMESTAMP (event) = GST_CLOCK_TIME_NONE;
279 GST_EVENT_SEQNUM (event) = gst_util_seqnum_next ();
280 event->running_time_offset = 0;
285 * gst_event_new_custom:
286 * @type: The type of the new event
287 * @structure: (transfer full): the structure for the event. The event will
288 * take ownership of the structure.
290 * Create a new custom-typed event. This can be used for anything not
291 * handled by other event-specific functions to pass an event to another
294 * Make sure to allocate an event type with the #GST_EVENT_MAKE_TYPE macro,
295 * assigning a free number and filling in the correct direction and
296 * serialization flags.
298 * New custom events can also be created by subclassing the event type if
301 * Returns: (transfer full): the new custom event.
304 gst_event_new_custom (GstEventType type, GstStructure * structure)
308 event = g_slice_new0 (GstEventImpl);
310 GST_CAT_DEBUG (GST_CAT_EVENT, "creating new event %p %s %d", event,
311 gst_event_type_get_name (type), type);
314 /* structure must not have a parent */
315 if (!gst_structure_set_parent_refcount (structure,
316 &event->event.mini_object.refcount))
320 gst_event_init (event, type);
322 GST_EVENT_STRUCTURE (event) = structure;
324 return GST_EVENT_CAST (event);
329 g_slice_free1 (sizeof (GstEventImpl), event);
330 g_warning ("structure is already owned by another object");
336 * gst_event_get_structure:
337 * @event: The #GstEvent.
339 * Access the structure of the event.
341 * Returns: (transfer none) (nullable): The structure of the event. The
342 * structure is still owned by the event, which means that you should not free
343 * it and that the pointer becomes invalid when you free the event.
348 gst_event_get_structure (GstEvent * event)
350 g_return_val_if_fail (GST_IS_EVENT (event), NULL);
352 return GST_EVENT_STRUCTURE (event);
356 * gst_event_writable_structure:
357 * @event: A writable #GstEvent.
359 * Get a writable version of the structure.
361 * Returns: (transfer none): The structure of the event. The structure
362 * is still owned by the event, which means that you should not free
363 * it and that the pointer becomes invalid when you free the event.
364 * This function ensures that @event is writable, and if so, will
365 * never return %NULL.
370 gst_event_writable_structure (GstEvent * event)
372 GstStructure *structure;
374 g_return_val_if_fail (GST_IS_EVENT (event), NULL);
375 g_return_val_if_fail (gst_event_is_writable (event), NULL);
377 structure = GST_EVENT_STRUCTURE (event);
379 if (structure == NULL) {
381 gst_structure_new_id_empty (gst_event_type_to_quark (GST_EVENT_TYPE
383 gst_structure_set_parent_refcount (structure, &event->mini_object.refcount);
384 GST_EVENT_STRUCTURE (event) = structure;
390 * gst_event_has_name:
391 * @event: The #GstEvent.
392 * @name: name to check
394 * Checks if @event has the given @name. This function is usually used to
395 * check the name of a custom event.
397 * Returns: %TRUE if @name matches the name of the event structure.
400 gst_event_has_name (GstEvent * event, const gchar * name)
402 g_return_val_if_fail (GST_IS_EVENT (event), FALSE);
404 if (GST_EVENT_STRUCTURE (event) == NULL)
407 return gst_structure_has_name (GST_EVENT_STRUCTURE (event), name);
411 * gst_event_has_name_id:
412 * @event: The #GstEvent.
413 * @name: name to check as a GQuark
415 * Checks if @event has the given @name. This function is usually used to
416 * check the name of a custom event.
418 * Returns: %TRUE if @name matches the name of the event structure.
423 gst_event_has_name_id (GstEvent * event, GQuark name)
425 g_return_val_if_fail (GST_IS_EVENT (event), FALSE);
427 if (GST_EVENT_STRUCTURE (event) == NULL)
430 return (GST_EVENT_STRUCTURE (event)->name == name);
434 * gst_event_get_seqnum:
435 * @event: A #GstEvent.
437 * Retrieve the sequence number of a event.
439 * Events have ever-incrementing sequence numbers, which may also be set
440 * explicitly via gst_event_set_seqnum(). Sequence numbers are typically used to
441 * indicate that a event corresponds to some other set of events or messages,
442 * for example an EOS event corresponding to a SEEK event. It is considered good
443 * practice to make this correspondence when possible, though it is not
446 * Note that events and messages share the same sequence number incrementor;
447 * two events or messages will never have the same sequence number unless
448 * that correspondence was made explicitly.
450 * Returns: The event's sequence number.
455 gst_event_get_seqnum (GstEvent * event)
457 g_return_val_if_fail (GST_IS_EVENT (event), -1);
459 return GST_EVENT_SEQNUM (event);
463 * gst_event_set_seqnum:
464 * @event: A #GstEvent.
465 * @seqnum: A sequence number.
467 * Set the sequence number of a event.
469 * This function might be called by the creator of a event to indicate that the
470 * event relates to other events or messages. See gst_event_get_seqnum() for
476 gst_event_set_seqnum (GstEvent * event, guint32 seqnum)
478 g_return_if_fail (GST_IS_EVENT (event));
479 g_return_if_fail (seqnum != GST_SEQNUM_INVALID);
480 g_return_if_fail (gst_event_is_writable (event));
482 GST_EVENT_SEQNUM (event) = seqnum;
486 * gst_event_get_running_time_offset:
487 * @event: A #GstEvent.
489 * Retrieve the accumulated running time offset of the event.
491 * Events passing through #GstPads that have a running time
492 * offset set via gst_pad_set_offset() will get their offset
493 * adjusted according to the pad's offset.
495 * If the event contains any information that related to the
496 * running time, this information will need to be updated
497 * before usage with this offset.
499 * Returns: The event's running time offset
506 gst_event_get_running_time_offset (GstEvent * event)
508 g_return_val_if_fail (GST_IS_EVENT (event), 0);
510 return ((GstEventImpl *) event)->running_time_offset;
514 * gst_event_set_running_time_offset:
515 * @event: A #GstEvent.
516 * @offset: A the new running time offset
518 * Set the running time offset of a event. See
519 * gst_event_get_running_time_offset() for more information.
526 gst_event_set_running_time_offset (GstEvent * event, gint64 offset)
528 g_return_if_fail (GST_IS_EVENT (event));
529 g_return_if_fail (gst_event_is_writable (event));
531 ((GstEventImpl *) event)->running_time_offset = offset;
535 * gst_event_new_flush_start:
537 * Allocate a new flush start event. The flush start event can be sent
538 * upstream and downstream and travels out-of-bounds with the dataflow.
540 * It marks pads as being flushing and will make them return
541 * #GST_FLOW_FLUSHING when used for data flow with gst_pad_push(),
542 * gst_pad_chain(), gst_pad_get_range() and gst_pad_pull_range().
543 * Any event (except a #GST_EVENT_FLUSH_STOP) received
544 * on a flushing pad will return %FALSE immediately.
546 * Elements should unlock any blocking functions and exit their streaming
547 * functions as fast as possible when this event is received.
549 * This event is typically generated after a seek to flush out all queued data
550 * in the pipeline so that the new media is played as soon as possible.
552 * Returns: (transfer full): a new flush start event.
555 gst_event_new_flush_start (void)
557 return gst_event_new_custom (GST_EVENT_FLUSH_START, NULL);
561 * gst_event_new_flush_stop:
562 * @reset_time: if time should be reset
564 * Allocate a new flush stop event. The flush stop event can be sent
565 * upstream and downstream and travels serialized with the dataflow.
566 * It is typically sent after sending a FLUSH_START event to make the
567 * pads accept data again.
569 * Elements can process this event synchronized with the dataflow since
570 * the preceding FLUSH_START event stopped the dataflow.
572 * This event is typically generated to complete a seek and to resume
575 * Returns: (transfer full): a new flush stop event.
578 gst_event_new_flush_stop (gboolean reset_time)
582 GST_CAT_INFO (GST_CAT_EVENT, "creating flush stop %d", reset_time);
584 event = gst_event_new_custom (GST_EVENT_FLUSH_STOP,
585 gst_structure_new_id (GST_QUARK (EVENT_FLUSH_STOP),
586 GST_QUARK (RESET_TIME), G_TYPE_BOOLEAN, reset_time, NULL));
592 * gst_event_parse_flush_stop:
593 * @event: The event to parse
594 * @reset_time: (out) (optional): if time should be reset
596 * Parse the FLUSH_STOP event and retrieve the @reset_time member.
599 gst_event_parse_flush_stop (GstEvent * event, gboolean * reset_time)
601 GstStructure *structure;
603 g_return_if_fail (GST_IS_EVENT (event));
604 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_FLUSH_STOP);
606 structure = GST_EVENT_STRUCTURE (event);
607 if (G_LIKELY (reset_time))
609 g_value_get_boolean (gst_structure_id_get_value (structure,
610 GST_QUARK (RESET_TIME)));
614 * gst_event_new_select_streams:
615 * @streams: (element-type utf8) (transfer none): the list of streams to
618 * Allocate a new select-streams event.
620 * The select-streams event requests the specified @streams to be activated.
622 * The list of @streams corresponds to the "Stream ID" of each stream to be
623 * activated. Those ID can be obtained via the #GstStream objects present
624 * in #GST_EVENT_STREAM_START, #GST_EVENT_STREAM_COLLECTION or
625 * #GST_MESSAGE_STREAM_COLLECTION.
627 * Note: The list of @streams can not be empty.
629 * Returns: (transfer full): a new select-streams event.
634 gst_event_new_select_streams (GList * streams)
637 GValue val = G_VALUE_INIT;
641 g_return_val_if_fail (streams != NULL, NULL);
643 GST_CAT_INFO (GST_CAT_EVENT, "Creating new select-streams event");
644 struc = gst_structure_new_id_empty (GST_QUARK (EVENT_SELECT_STREAMS));
645 g_value_init (&val, GST_TYPE_LIST);
646 /* Fill struc with streams */
647 for (tmpl = streams; tmpl; tmpl = tmpl->next) {
648 GValue strval = G_VALUE_INIT;
649 const gchar *str = (const gchar *) tmpl->data;
650 g_value_init (&strval, G_TYPE_STRING);
651 g_value_set_string (&strval, str);
652 gst_value_list_append_and_take_value (&val, &strval);
654 gst_structure_id_take_value (struc, GST_QUARK (STREAMS), &val);
655 event = gst_event_new_custom (GST_EVENT_SELECT_STREAMS, struc);
661 * gst_event_parse_select_streams:
662 * @event: The event to parse
663 * @streams: (out) (optional) (element-type utf8) (transfer full): the streams
665 * Parse the SELECT_STREAMS event and retrieve the contained streams.
670 gst_event_parse_select_streams (GstEvent * event, GList ** streams)
672 GstStructure *structure;
675 g_return_if_fail (GST_IS_EVENT (event));
676 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_SELECT_STREAMS);
678 structure = GST_EVENT_STRUCTURE (event);
679 if (G_LIKELY (streams)) {
680 const GValue *vlist =
681 gst_structure_id_get_value (structure, GST_QUARK (STREAMS));
682 guint i, sz = gst_value_list_get_size (vlist);
683 for (i = 0; i < sz; i++) {
684 const GValue *strv = gst_value_list_get_value (vlist, i);
685 res = g_list_append (res, g_value_dup_string (strv));
693 * gst_event_new_stream_group_done:
694 * @group_id: the group id of the stream group which is ending
696 * Create a new Stream Group Done event. The stream-group-done event can
697 * only travel downstream synchronized with the buffer flow. Elements
698 * that receive the event on a pad should handle it mostly like EOS,
699 * and emit any data or pending buffers that would depend on more data
700 * arriving and unblock, since there won't be any more data.
702 * This event is followed by EOS at some point in the future, and is
703 * generally used when switching pads - to unblock downstream so that
704 * new pads can be exposed before sending EOS on the existing pads.
706 * Returns: (transfer full): the new stream-group-done event.
711 gst_event_new_stream_group_done (guint group_id)
715 g_return_val_if_fail (group_id != GST_GROUP_ID_INVALID, NULL);
717 s = gst_structure_new_id (GST_QUARK (EVENT_STREAM_GROUP_DONE),
718 GST_QUARK (GROUP_ID), G_TYPE_UINT, group_id, NULL);
720 return gst_event_new_custom (GST_EVENT_STREAM_GROUP_DONE, s);
724 * gst_event_parse_stream_group_done:
725 * @event: a stream-group-done event.
726 * @group_id: (out) (optional): address of variable to store the group id into
728 * Parse a stream-group-done @event and store the result in the given
729 * @group_id location.
734 gst_event_parse_stream_group_done (GstEvent * event, guint * group_id)
736 g_return_if_fail (event != NULL);
737 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STREAM_GROUP_DONE);
740 gst_structure_id_get (GST_EVENT_STRUCTURE (event),
741 GST_QUARK (GROUP_ID), G_TYPE_UINT, group_id, NULL);
748 * Create a new EOS event. The eos event can only travel downstream
749 * synchronized with the buffer flow. Elements that receive the EOS
750 * event on a pad can return #GST_FLOW_EOS as a #GstFlowReturn
751 * when data after the EOS event arrives.
753 * The EOS event will travel down to the sink elements in the pipeline
754 * which will then post the #GST_MESSAGE_EOS on the bus after they have
755 * finished playing any buffered data.
757 * When all sinks have posted an EOS message, an EOS message is
758 * forwarded to the application.
760 * The EOS event itself will not cause any state transitions of the pipeline.
762 * Returns: (transfer full): the new EOS event.
765 gst_event_new_eos (void)
767 return gst_event_new_custom (GST_EVENT_EOS, NULL);
772 * @timestamp: the start time (pts) of the gap
773 * @duration: the duration of the gap
775 * Create a new GAP event. A gap event can be thought of as conceptually
776 * equivalent to a buffer to signal that there is no data for a certain
777 * amount of time. This is useful to signal a gap to downstream elements
778 * which may wait for data, such as muxers or mixers or overlays, especially
779 * for sparse streams such as subtitle streams.
781 * Returns: (transfer full): the new GAP event.
784 gst_event_new_gap (GstClockTime timestamp, GstClockTime duration)
788 g_return_val_if_fail (GST_CLOCK_TIME_IS_VALID (timestamp), NULL);
790 GST_CAT_TRACE (GST_CAT_EVENT, "creating gap %" GST_TIME_FORMAT " - "
791 "%" GST_TIME_FORMAT " (duration: %" GST_TIME_FORMAT ")",
792 GST_TIME_ARGS (timestamp), GST_TIME_ARGS (timestamp + duration),
793 GST_TIME_ARGS (duration));
795 event = gst_event_new_custom (GST_EVENT_GAP,
796 gst_structure_new_id (GST_QUARK (EVENT_GAP),
797 GST_QUARK (TIMESTAMP), GST_TYPE_CLOCK_TIME, timestamp,
798 GST_QUARK (DURATION), GST_TYPE_CLOCK_TIME, duration, NULL));
804 * gst_event_parse_gap:
805 * @event: a #GstEvent of type #GST_EVENT_GAP
806 * @timestamp: (out) (optional): location where to store the
807 * start time (pts) of the gap, or %NULL
808 * @duration: (out) (optional): location where to store the duration of
811 * Extract timestamp and duration from a new GAP event.
814 gst_event_parse_gap (GstEvent * event, GstClockTime * timestamp,
815 GstClockTime * duration)
817 GstStructure *structure;
819 g_return_if_fail (GST_IS_EVENT (event));
820 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_GAP);
822 structure = GST_EVENT_STRUCTURE (event);
823 gst_structure_id_get (structure,
824 GST_QUARK (TIMESTAMP), GST_TYPE_CLOCK_TIME, timestamp,
825 GST_QUARK (DURATION), GST_TYPE_CLOCK_TIME, duration, NULL);
829 * gst_event_set_gap_flags:
830 * @event: a #GstEvent of type #GST_EVENT_GAP
831 * @flags: a #GstGapFlags
833 * Sets @flags on @event to give additional information about the reason for
834 * the #GST_EVENT_GAP.
839 gst_event_set_gap_flags (GstEvent * event, GstGapFlags flags)
841 g_return_if_fail (event != NULL);
842 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_GAP);
843 g_return_if_fail (gst_event_is_writable (event));
845 gst_structure_id_set (GST_EVENT_STRUCTURE (event),
846 GST_QUARK (GAP_FLAGS), GST_TYPE_GAP_FLAGS, flags, NULL);
850 * gst_event_parse_gap_flags:
851 * @event: a #GstEvent of type #GST_EVENT_GAP
852 * @flags: (out) (optional): a #GstGapFlags or %NULL
854 * Retrieve the gap flags that may have been set on a gap event with
855 * gst_event_set_gap_flags().
860 gst_event_parse_gap_flags (GstEvent * event, GstGapFlags * flags)
862 g_return_if_fail (event != NULL);
863 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_GAP);
865 /* Initialize to 0 for GAP events that don't have the field set */
869 gst_structure_id_get (GST_EVENT_STRUCTURE (event),
870 GST_QUARK (GAP_FLAGS), GST_TYPE_GAP_FLAGS, flags, NULL);
874 * gst_event_new_caps:
875 * @caps: (transfer none): a #GstCaps
877 * Create a new CAPS event for @caps. The caps event can only travel downstream
878 * synchronized with the buffer flow and contains the format of the buffers
879 * that will follow after the event.
881 * Returns: (transfer full): the new CAPS event.
884 gst_event_new_caps (GstCaps * caps)
888 g_return_val_if_fail (caps != NULL, NULL);
889 g_return_val_if_fail (gst_caps_is_fixed (caps), NULL);
891 GST_CAT_INFO (GST_CAT_EVENT, "creating caps event %" GST_PTR_FORMAT, caps);
893 event = gst_event_new_custom (GST_EVENT_CAPS,
894 gst_structure_new_id (GST_QUARK (EVENT_CAPS),
895 GST_QUARK (CAPS), GST_TYPE_CAPS, caps, NULL));
901 * gst_event_parse_caps:
902 * @event: The event to parse
903 * @caps: (out) (optional) (transfer none): A pointer to the caps
905 * Get the caps from @event. The caps remains valid as long as @event remains
909 gst_event_parse_caps (GstEvent * event, GstCaps ** caps)
911 GstStructure *structure;
913 g_return_if_fail (GST_IS_EVENT (event));
914 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_CAPS);
916 structure = GST_EVENT_STRUCTURE (event);
919 g_value_get_boxed (gst_structure_id_get_value (structure,
924 * gst_event_new_segment:
925 * @segment: (transfer none): a #GstSegment
927 * Create a new SEGMENT event for @segment. The segment event can only travel
928 * downstream synchronized with the buffer flow and contains timing information
929 * and playback properties for the buffers that will follow.
931 * The segment event marks the range of buffers to be processed. All
932 * data not within the segment range is not to be processed. This can be
933 * used intelligently by plugins to apply more efficient methods of skipping
934 * unneeded data. The valid range is expressed with the @start and @stop
937 * The time value of the segment is used in conjunction with the start
938 * value to convert the buffer timestamps into the stream time. This is
939 * usually done in sinks to report the current stream_time.
940 * @time represents the stream_time of a buffer carrying a timestamp of
941 * @start. @time cannot be -1.
943 * @start cannot be -1, @stop can be -1. If there
944 * is a valid @stop given, it must be greater or equal the @start, including
945 * when the indicated playback @rate is < 0.
947 * The @applied_rate value provides information about any rate adjustment that
948 * has already been made to the timestamps and content on the buffers of the
949 * stream. (@rate * @applied_rate) should always equal the rate that has been
950 * requested for playback. For example, if an element has an input segment
951 * with intended playback @rate of 2.0 and applied_rate of 1.0, it can adjust
952 * incoming timestamps and buffer content by half and output a segment event
953 * with @rate of 1.0 and @applied_rate of 2.0
955 * After a segment event, the buffer stream time is calculated with:
957 * time + (TIMESTAMP(buf) - start) * ABS (rate * applied_rate)
959 * Returns: (transfer full): the new SEGMENT event.
962 gst_event_new_segment (const GstSegment * segment)
966 g_return_val_if_fail (segment != NULL, NULL);
967 g_return_val_if_fail (segment->rate != 0.0, NULL);
968 g_return_val_if_fail (segment->applied_rate != 0.0, NULL);
969 g_return_val_if_fail (segment->format != GST_FORMAT_UNDEFINED, NULL);
971 GST_CAT_INFO (GST_CAT_EVENT, "creating segment event %" GST_SEGMENT_FORMAT,
974 event = gst_event_new_custom (GST_EVENT_SEGMENT,
975 gst_structure_new_id (GST_QUARK (EVENT_SEGMENT),
976 GST_QUARK (SEGMENT), GST_TYPE_SEGMENT, segment, NULL));
982 * gst_event_parse_segment:
983 * @event: The event to parse
984 * @segment: (out) (optional) (transfer none): a pointer to a #GstSegment
986 * Parses a segment @event and stores the result in the given @segment location.
987 * @segment remains valid only until the @event is freed. Don't modify the segment
988 * and make a copy if you want to modify it or store it for later use.
991 gst_event_parse_segment (GstEvent * event, const GstSegment ** segment)
993 GstStructure *structure;
995 g_return_if_fail (GST_IS_EVENT (event));
996 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_SEGMENT);
999 structure = GST_EVENT_STRUCTURE (event);
1000 *segment = g_value_get_boxed (gst_structure_id_get_value (structure,
1001 GST_QUARK (SEGMENT)));
1006 * gst_event_copy_segment:
1007 * @event: The event to parse
1008 * @segment: a pointer to a #GstSegment
1010 * Parses a segment @event and copies the #GstSegment into the location
1011 * given by @segment.
1014 gst_event_copy_segment (GstEvent * event, GstSegment * segment)
1016 const GstSegment *src;
1018 g_return_if_fail (GST_IS_EVENT (event));
1019 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_SEGMENT);
1022 gst_event_parse_segment (event, &src);
1023 gst_segment_copy_into (src, segment);
1028 * gst_event_new_tag:
1029 * @taglist: (transfer full): metadata list. The event will take ownership
1032 * Generates a metadata tag event from the given @taglist.
1034 * The scope of the taglist specifies if the taglist applies to the
1035 * complete medium or only to this specific stream. As the tag event
1036 * is a sticky event, elements should merge tags received from
1037 * upstream with a given scope with their own tags with the same
1038 * scope and create a new tag event from it.
1040 * Returns: (transfer full): a new #GstEvent
1043 gst_event_new_tag (GstTagList * taglist)
1046 GValue val = G_VALUE_INIT;
1047 const gchar *names[] = { "GstTagList-stream", "GstTagList-global" };
1049 g_return_val_if_fail (taglist != NULL, NULL);
1051 s = gst_structure_new_empty (names[gst_tag_list_get_scope (taglist)]);
1052 g_value_init (&val, GST_TYPE_TAG_LIST);
1053 g_value_take_boxed (&val, taglist);
1054 gst_structure_id_take_value (s, GST_QUARK (TAGLIST), &val);
1055 return gst_event_new_custom (GST_EVENT_TAG, s);
1059 * gst_event_parse_tag:
1060 * @event: a tag event
1061 * @taglist: (out) (optional) (transfer none): pointer to metadata list
1063 * Parses a tag @event and stores the results in the given @taglist location.
1064 * No reference to the taglist will be returned, it remains valid only until
1065 * the @event is freed. Don't modify or free the taglist, make a copy if you
1066 * want to modify it or store it for later use.
1069 gst_event_parse_tag (GstEvent * event, GstTagList ** taglist)
1073 g_return_if_fail (GST_IS_EVENT (event));
1074 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_TAG);
1076 val = gst_structure_id_get_value (GST_EVENT_STRUCTURE (event),
1077 GST_QUARK (TAGLIST));
1080 *taglist = (GstTagList *) g_value_get_boxed (val);
1083 /* buffersize event */
1085 * gst_event_new_buffer_size:
1086 * @format: buffer format
1087 * @minsize: minimum buffer size
1088 * @maxsize: maximum buffer size
1089 * @async: thread behavior
1091 * Create a new buffersize event. The event is sent downstream and notifies
1092 * elements that they should provide a buffer of the specified dimensions.
1094 * When the @async flag is set, a thread boundary is preferred.
1096 * Returns: (transfer full): a new #GstEvent
1099 gst_event_new_buffer_size (GstFormat format, gint64 minsize,
1100 gint64 maxsize, gboolean async)
1103 GstStructure *structure;
1105 GST_CAT_INFO (GST_CAT_EVENT,
1106 "creating buffersize format %s, minsize %" G_GINT64_FORMAT
1107 ", maxsize %" G_GINT64_FORMAT ", async %d", gst_format_get_name (format),
1108 minsize, maxsize, async);
1110 structure = gst_structure_new_id (GST_QUARK (EVENT_BUFFER_SIZE),
1111 GST_QUARK (FORMAT), GST_TYPE_FORMAT, format,
1112 GST_QUARK (MINSIZE), G_TYPE_INT64, minsize,
1113 GST_QUARK (MAXSIZE), G_TYPE_INT64, maxsize,
1114 GST_QUARK (ASYNC), G_TYPE_BOOLEAN, async, NULL);
1115 event = gst_event_new_custom (GST_EVENT_BUFFERSIZE, structure);
1121 * gst_event_parse_buffer_size:
1122 * @event: The event to query
1123 * @format: (out) (optional): A pointer to store the format in
1124 * @minsize: (out) (optional): A pointer to store the minsize in
1125 * @maxsize: (out) (optional): A pointer to store the maxsize in
1126 * @async: (out) (optional): A pointer to store the async-flag in
1128 * Get the format, minsize, maxsize and async-flag in the buffersize event.
1131 gst_event_parse_buffer_size (GstEvent * event, GstFormat * format,
1132 gint64 * minsize, gint64 * maxsize, gboolean * async)
1134 const GstStructure *structure;
1136 g_return_if_fail (GST_IS_EVENT (event));
1137 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_BUFFERSIZE);
1139 structure = GST_EVENT_STRUCTURE (event);
1141 *format = (GstFormat)
1142 g_value_get_enum (gst_structure_id_get_value (structure,
1143 GST_QUARK (FORMAT)));
1146 g_value_get_int64 (gst_structure_id_get_value (structure,
1147 GST_QUARK (MINSIZE)));
1150 g_value_get_int64 (gst_structure_id_get_value (structure,
1151 GST_QUARK (MAXSIZE)));
1154 g_value_get_boolean (gst_structure_id_get_value (structure,
1155 GST_QUARK (ASYNC)));
1159 * gst_event_new_qos:
1160 * @type: the QoS type
1161 * @proportion: the proportion of the qos message
1162 * @diff: The time difference of the last Clock sync
1163 * @timestamp: The timestamp of the buffer
1165 * Allocate a new qos event with the given values.
1166 * The QOS event is generated in an element that wants an upstream
1167 * element to either reduce or increase its rate because of
1168 * high/low CPU load or other resource usage such as network performance or
1169 * throttling. Typically sinks generate these events for each buffer
1172 * @type indicates the reason for the QoS event. #GST_QOS_TYPE_OVERFLOW is
1173 * used when a buffer arrived in time or when the sink cannot keep up with
1174 * the upstream datarate. #GST_QOS_TYPE_UNDERFLOW is when the sink is not
1175 * receiving buffers fast enough and thus has to drop late buffers.
1176 * #GST_QOS_TYPE_THROTTLE is used when the datarate is artificially limited
1177 * by the application, for example to reduce power consumption.
1179 * @proportion indicates the real-time performance of the streaming in the
1180 * element that generated the QoS event (usually the sink). The value is
1181 * generally computed based on more long term statistics about the streams
1182 * timestamps compared to the clock.
1183 * A value < 1.0 indicates that the upstream element is producing data faster
1184 * than real-time. A value > 1.0 indicates that the upstream element is not
1185 * producing data fast enough. 1.0 is the ideal @proportion value. The
1186 * proportion value can safely be used to lower or increase the quality of
1189 * @diff is the difference against the clock in running time of the last
1190 * buffer that caused the element to generate the QOS event. A negative value
1191 * means that the buffer with @timestamp arrived in time. A positive value
1192 * indicates how late the buffer with @timestamp was. When throttling is
1193 * enabled, @diff will be set to the requested throttling interval.
1195 * @timestamp is the timestamp of the last buffer that cause the element
1196 * to generate the QOS event. It is expressed in running time and thus an ever
1199 * The upstream element can use the @diff and @timestamp values to decide
1200 * whether to process more buffers. For positive @diff, all buffers with
1201 * timestamp <= @timestamp + @diff will certainly arrive late in the sink
1202 * as well. A (negative) @diff value so that @timestamp + @diff would yield a
1203 * result smaller than 0 is not allowed.
1205 * The application can use general event probes to intercept the QoS
1206 * event and implement custom application specific QoS handling.
1208 * Returns: (transfer full): a new QOS event.
1211 gst_event_new_qos (GstQOSType type, gdouble proportion,
1212 GstClockTimeDiff diff, GstClockTime timestamp)
1215 GstStructure *structure;
1217 /* diff must be positive or timestamp + diff must be positive */
1218 g_return_val_if_fail (diff >= 0 || -diff <= timestamp, NULL);
1220 GST_CAT_LOG (GST_CAT_EVENT,
1221 "creating qos type %d, proportion %lf, diff %" G_GINT64_FORMAT
1222 ", timestamp %" GST_TIME_FORMAT, type, proportion,
1223 diff, GST_TIME_ARGS (timestamp));
1225 structure = gst_structure_new_id (GST_QUARK (EVENT_QOS),
1226 GST_QUARK (TYPE), GST_TYPE_QOS_TYPE, type,
1227 GST_QUARK (PROPORTION), G_TYPE_DOUBLE, proportion,
1228 GST_QUARK (DIFF), G_TYPE_INT64, diff,
1229 GST_QUARK (TIMESTAMP), G_TYPE_UINT64, timestamp, NULL);
1230 event = gst_event_new_custom (GST_EVENT_QOS, structure);
1236 * gst_event_parse_qos:
1237 * @event: The event to query
1238 * @type: (out) (optional): A pointer to store the QoS type in
1239 * @proportion: (out) (optional): A pointer to store the proportion in
1240 * @diff: (out) (optional): A pointer to store the diff in
1241 * @timestamp: (out) (optional): A pointer to store the timestamp in
1243 * Get the type, proportion, diff and timestamp in the qos event. See
1244 * gst_event_new_qos() for more information about the different QoS values.
1246 * @timestamp will be adjusted for any pad offsets of pads it was passing through.
1249 gst_event_parse_qos (GstEvent * event, GstQOSType * type,
1250 gdouble * proportion, GstClockTimeDiff * diff, GstClockTime * timestamp)
1252 const GstStructure *structure;
1254 g_return_if_fail (GST_IS_EVENT (event));
1255 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_QOS);
1257 structure = GST_EVENT_STRUCTURE (event);
1259 *type = (GstQOSType)
1260 g_value_get_enum (gst_structure_id_get_value (structure,
1264 g_value_get_double (gst_structure_id_get_value (structure,
1265 GST_QUARK (PROPORTION)));
1268 g_value_get_int64 (gst_structure_id_get_value (structure,
1271 gint64 offset = gst_event_get_running_time_offset (event);
1272 GstClockTimeDiff diff_ =
1273 g_value_get_int64 (gst_structure_id_get_value (structure,
1277 g_value_get_uint64 (gst_structure_id_get_value (structure,
1278 GST_QUARK (TIMESTAMP)));
1279 /* Catch underflows */
1280 if (*timestamp > -offset)
1281 *timestamp += offset;
1285 /* Make sure that timestamp + diff is always >= 0. Because
1286 * of the running time offset this might not be true */
1287 if (diff_ < 0 && *timestamp < -diff_)
1288 *timestamp = (GstClockTime) - diff_;
1293 * gst_event_new_seek:
1294 * @rate: The new playback rate
1295 * @format: The format of the seek values
1296 * @flags: The optional seek flags
1297 * @start_type: The type and flags for the new start position
1298 * @start: The value of the new start position
1299 * @stop_type: The type and flags for the new stop position
1300 * @stop: The value of the new stop position
1302 * Allocate a new seek event with the given parameters.
1304 * The seek event configures playback of the pipeline between @start to @stop
1305 * at the speed given in @rate, also called a playback segment.
1306 * The @start and @stop values are expressed in @format.
1308 * A @rate of 1.0 means normal playback rate, 2.0 means double speed.
1309 * Negatives values means backwards playback. A value of 0.0 for the
1310 * rate is not allowed and should be accomplished instead by PAUSING the
1313 * A pipeline has a default playback segment configured with a start
1314 * position of 0, a stop position of -1 and a rate of 1.0. The currently
1315 * configured playback segment can be queried with #GST_QUERY_SEGMENT.
1317 * @start_type and @stop_type specify how to adjust the currently configured
1318 * start and stop fields in playback segment. Adjustments can be made relative
1319 * or absolute to the last configured values. A type of #GST_SEEK_TYPE_NONE
1320 * means that the position should not be updated.
1322 * When the rate is positive and @start has been updated, playback will start
1323 * from the newly configured start position.
1325 * For negative rates, playback will start from the newly configured stop
1326 * position (if any). If the stop position is updated, it must be different from
1327 * -1 (#GST_CLOCK_TIME_NONE) for negative rates.
1329 * It is not possible to seek relative to the current playback position, to do
1330 * this, PAUSE the pipeline, query the current playback position with
1331 * #GST_QUERY_POSITION and update the playback segment current position with a
1332 * #GST_SEEK_TYPE_SET to the desired position.
1334 * Returns: (transfer full): a new seek event.
1337 gst_event_new_seek (gdouble rate, GstFormat format, GstSeekFlags flags,
1338 GstSeekType start_type, gint64 start, GstSeekType stop_type, gint64 stop)
1341 GstStructure *structure;
1343 g_return_val_if_fail (rate != 0.0, NULL);
1344 g_return_val_if_fail ((flags & GST_SEEK_FLAG_INSTANT_RATE_CHANGE) == 0
1345 || (start_type == GST_SEEK_TYPE_NONE
1346 && stop_type == GST_SEEK_TYPE_NONE
1347 && (flags & GST_SEEK_FLAG_FLUSH) == 0), NULL);
1349 /* SNAP flags only make sense in combination with the KEYUNIT flag. Warn
1350 * and unset the SNAP flags if they're set without the KEYUNIT flag */
1351 if (!(flags & GST_SEEK_FLAG_KEY_UNIT) &&
1352 (flags & (GST_SEEK_FLAG_SNAP_BEFORE | GST_SEEK_FLAG_SNAP_AFTER |
1353 GST_SEEK_FLAG_SNAP_NEAREST))) {
1354 g_warning ("SNAP seeks only work in combination with the KEY_UNIT "
1355 "flag, ignoring SNAP flags");
1357 ~(GST_SEEK_FLAG_SNAP_BEFORE | GST_SEEK_FLAG_SNAP_AFTER |
1358 GST_SEEK_FLAG_SNAP_NEAREST);
1361 if (format == GST_FORMAT_TIME) {
1362 GST_CAT_INFO (GST_CAT_EVENT,
1363 "creating seek rate %lf, format TIME, flags %d, "
1364 "start_type %d, start %" GST_TIME_FORMAT ", "
1365 "stop_type %d, stop %" GST_TIME_FORMAT,
1366 rate, flags, start_type, GST_TIME_ARGS (start),
1367 stop_type, GST_TIME_ARGS (stop));
1369 GST_CAT_INFO (GST_CAT_EVENT,
1370 "creating seek rate %lf, format %s, flags %d, "
1371 "start_type %d, start %" G_GINT64_FORMAT ", "
1372 "stop_type %d, stop %" G_GINT64_FORMAT,
1373 rate, gst_format_get_name (format), flags, start_type, start, stop_type,
1377 structure = gst_structure_new_id (GST_QUARK (EVENT_SEEK),
1378 GST_QUARK (RATE), G_TYPE_DOUBLE, rate,
1379 GST_QUARK (FORMAT), GST_TYPE_FORMAT, format,
1380 GST_QUARK (FLAGS), GST_TYPE_SEEK_FLAGS, flags,
1381 GST_QUARK (CUR_TYPE), GST_TYPE_SEEK_TYPE, start_type,
1382 GST_QUARK (CUR), G_TYPE_INT64, start,
1383 GST_QUARK (STOP_TYPE), GST_TYPE_SEEK_TYPE, stop_type,
1384 GST_QUARK (STOP), G_TYPE_INT64, stop,
1385 GST_QUARK (TRICKMODE_INTERVAL), GST_TYPE_CLOCK_TIME, (GstClockTime) 0,
1387 event = gst_event_new_custom (GST_EVENT_SEEK, structure);
1393 * gst_event_parse_seek:
1394 * @event: a seek event
1395 * @rate: (out) (optional): result location for the rate
1396 * @format: (out) (optional): result location for the stream format
1397 * @flags: (out) (optional): result location for the #GstSeekFlags
1398 * @start_type: (out) (optional): result location for the #GstSeekType of the start position
1399 * @start: (out) (optional): result location for the start position expressed in @format
1400 * @stop_type: (out) (optional): result location for the #GstSeekType of the stop position
1401 * @stop: (out) (optional): result location for the stop position expressed in @format
1403 * Parses a seek @event and stores the results in the given result locations.
1406 gst_event_parse_seek (GstEvent * event, gdouble * rate,
1407 GstFormat * format, GstSeekFlags * flags, GstSeekType * start_type,
1408 gint64 * start, GstSeekType * stop_type, gint64 * stop)
1410 const GstStructure *structure;
1412 g_return_if_fail (GST_IS_EVENT (event));
1413 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_SEEK);
1415 structure = GST_EVENT_STRUCTURE (event);
1418 g_value_get_double (gst_structure_id_get_value (structure,
1421 *format = (GstFormat)
1422 g_value_get_enum (gst_structure_id_get_value (structure,
1423 GST_QUARK (FORMAT)));
1425 *flags = (GstSeekFlags)
1426 g_value_get_flags (gst_structure_id_get_value (structure,
1427 GST_QUARK (FLAGS)));
1429 *start_type = (GstSeekType)
1430 g_value_get_enum (gst_structure_id_get_value (structure,
1431 GST_QUARK (CUR_TYPE)));
1434 g_value_get_int64 (gst_structure_id_get_value (structure,
1437 *stop_type = (GstSeekType)
1438 g_value_get_enum (gst_structure_id_get_value (structure,
1439 GST_QUARK (STOP_TYPE)));
1442 g_value_get_int64 (gst_structure_id_get_value (structure,
1447 * gst_event_set_seek_trickmode_interval:
1449 * Sets a trickmode interval on a (writable) seek event. Elements
1450 * that support TRICKMODE_KEY_UNITS seeks SHOULD use this as the minimal
1451 * interval between each frame they may output.
1456 gst_event_set_seek_trickmode_interval (GstEvent * event, GstClockTime interval)
1458 g_return_if_fail (event != NULL);
1459 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_SEEK);
1460 g_return_if_fail (gst_event_is_writable (event));
1461 g_return_if_fail (GST_CLOCK_TIME_IS_VALID (interval));
1463 gst_structure_id_set (GST_EVENT_STRUCTURE (event),
1464 GST_QUARK (TRICKMODE_INTERVAL), GST_TYPE_CLOCK_TIME, interval, NULL);
1468 * gst_event_parse_seek_trickmode_interval:
1469 * @interval: (out) (optional): interval
1471 * Retrieve the trickmode interval that may have been set on a
1472 * seek event with gst_event_set_seek_trickmode_interval().
1477 gst_event_parse_seek_trickmode_interval (GstEvent * event,
1478 GstClockTime * interval)
1480 g_return_if_fail (event != NULL);
1481 g_return_if_fail (interval != NULL);
1482 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_SEEK);
1485 *interval = GST_CLOCK_TIME_NONE;
1487 gst_structure_id_get (GST_EVENT_STRUCTURE (event),
1488 GST_QUARK (TRICKMODE_INTERVAL), GST_TYPE_CLOCK_TIME, interval, NULL);
1492 * gst_event_new_navigation:
1493 * @structure: (transfer full): description of the event. The event will take
1494 * ownership of the structure. See #GstNavigation for more specific
1497 * Create a new navigation event from the given description.
1499 * Returns: (transfer full): a new #GstEvent
1502 gst_event_new_navigation (GstStructure * structure)
1504 g_return_val_if_fail (structure != NULL, NULL);
1506 return gst_event_new_custom (GST_EVENT_NAVIGATION, structure);
1510 * gst_event_new_latency:
1511 * @latency: the new latency value
1513 * Create a new latency event. The event is sent upstream from the sinks and
1514 * notifies elements that they should add an additional @latency to the
1515 * running time before synchronising against the clock.
1517 * The latency is mostly used in live sinks and is always expressed in
1520 * Returns: (transfer full): a new #GstEvent
1523 gst_event_new_latency (GstClockTime latency)
1526 GstStructure *structure;
1528 g_return_val_if_fail (GST_CLOCK_TIME_IS_VALID (latency), NULL);
1530 GST_CAT_INFO (GST_CAT_EVENT,
1531 "creating latency event %" GST_TIME_FORMAT, GST_TIME_ARGS (latency));
1533 structure = gst_structure_new_id (GST_QUARK (EVENT_LATENCY),
1534 GST_QUARK (LATENCY), G_TYPE_UINT64, latency, NULL);
1535 event = gst_event_new_custom (GST_EVENT_LATENCY, structure);
1541 * gst_event_parse_latency:
1542 * @event: The event to query
1543 * @latency: (out) (optional): A pointer to store the latency in.
1545 * Get the latency in the latency event.
1548 gst_event_parse_latency (GstEvent * event, GstClockTime * latency)
1550 g_return_if_fail (GST_IS_EVENT (event));
1551 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_LATENCY);
1555 g_value_get_uint64 (gst_structure_id_get_value (GST_EVENT_STRUCTURE
1556 (event), GST_QUARK (LATENCY)));
1560 * gst_event_new_step:
1561 * @format: the format of @amount
1562 * @amount: the amount of data to step
1563 * @rate: the step rate
1564 * @flush: flushing steps
1565 * @intermediate: intermediate steps
1567 * Create a new step event. The purpose of the step event is to instruct a sink
1568 * to skip @amount (expressed in @format) of media. It can be used to implement
1569 * stepping through the video frame by frame or for doing fast trick modes.
1571 * A rate of <= 0.0 is not allowed. Pause the pipeline, for the effect of rate
1572 * = 0.0 or first reverse the direction of playback using a seek event to get
1573 * the same effect as rate < 0.0.
1575 * The @flush flag will clear any pending data in the pipeline before starting
1576 * the step operation.
1578 * The @intermediate flag instructs the pipeline that this step operation is
1579 * part of a larger step operation.
1581 * Returns: (transfer full): a new #GstEvent
1584 gst_event_new_step (GstFormat format, guint64 amount, gdouble rate,
1585 gboolean flush, gboolean intermediate)
1588 GstStructure *structure;
1590 g_return_val_if_fail (rate > 0.0, NULL);
1592 GST_CAT_INFO (GST_CAT_EVENT, "creating step event");
1594 structure = gst_structure_new_id (GST_QUARK (EVENT_STEP),
1595 GST_QUARK (FORMAT), GST_TYPE_FORMAT, format,
1596 GST_QUARK (AMOUNT), G_TYPE_UINT64, amount,
1597 GST_QUARK (RATE), G_TYPE_DOUBLE, rate,
1598 GST_QUARK (FLUSH), G_TYPE_BOOLEAN, flush,
1599 GST_QUARK (INTERMEDIATE), G_TYPE_BOOLEAN, intermediate, NULL);
1600 event = gst_event_new_custom (GST_EVENT_STEP, structure);
1606 * gst_event_parse_step:
1607 * @event: The event to query
1608 * @format: (out) (optional): a pointer to store the format in
1609 * @amount: (out) (optional): a pointer to store the amount in
1610 * @rate: (out) (optional): a pointer to store the rate in
1611 * @flush: (out) (optional): a pointer to store the flush boolean in
1612 * @intermediate: (out) (optional): a pointer to store the intermediate
1615 * Parse the step event.
1618 gst_event_parse_step (GstEvent * event, GstFormat * format, guint64 * amount,
1619 gdouble * rate, gboolean * flush, gboolean * intermediate)
1621 const GstStructure *structure;
1623 g_return_if_fail (GST_IS_EVENT (event));
1624 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STEP);
1626 structure = GST_EVENT_STRUCTURE (event);
1629 (GstFormat) g_value_get_enum (gst_structure_id_get_value (structure,
1630 GST_QUARK (FORMAT)));
1632 *amount = g_value_get_uint64 (gst_structure_id_get_value (structure,
1633 GST_QUARK (AMOUNT)));
1635 *rate = g_value_get_double (gst_structure_id_get_value (structure,
1638 *flush = g_value_get_boolean (gst_structure_id_get_value (structure,
1639 GST_QUARK (FLUSH)));
1641 *intermediate = g_value_get_boolean (gst_structure_id_get_value (structure,
1642 GST_QUARK (INTERMEDIATE)));
1646 * gst_event_new_reconfigure:
1648 * Create a new reconfigure event. The purpose of the reconfigure event is
1649 * to travel upstream and make elements renegotiate their caps or reconfigure
1650 * their buffer pools. This is useful when changing properties on elements
1651 * or changing the topology of the pipeline.
1653 * Returns: (transfer full): a new #GstEvent
1656 gst_event_new_reconfigure (void)
1660 GST_CAT_INFO (GST_CAT_EVENT, "creating reconfigure event");
1662 event = gst_event_new_custom (GST_EVENT_RECONFIGURE, NULL);
1668 * gst_event_new_sink_message:
1669 * @name: a name for the event
1670 * @msg: (transfer none): the #GstMessage to be posted
1672 * Create a new sink-message event. The purpose of the sink-message event is
1673 * to instruct a sink to post the message contained in the event synchronized
1676 * @name is used to store multiple sticky events on one pad.
1678 * Returns: (transfer full): a new #GstEvent
1680 /* FIXME 2.0: take ownership of msg for consistency? */
1682 gst_event_new_sink_message (const gchar * name, GstMessage * msg)
1685 GstStructure *structure;
1687 g_return_val_if_fail (msg != NULL, NULL);
1689 GST_CAT_INFO (GST_CAT_EVENT, "creating sink-message event");
1691 structure = gst_structure_new_id (g_quark_from_string (name),
1692 GST_QUARK (MESSAGE), GST_TYPE_MESSAGE, msg, NULL);
1693 event = gst_event_new_custom (GST_EVENT_SINK_MESSAGE, structure);
1699 * gst_event_parse_sink_message:
1700 * @event: The event to query
1701 * @msg: (out) (optional) (transfer full): a pointer to store the #GstMessage in.
1703 * Parse the sink-message event. Unref @msg after usage.
1706 gst_event_parse_sink_message (GstEvent * event, GstMessage ** msg)
1708 const GstStructure *structure;
1710 g_return_if_fail (GST_IS_EVENT (event));
1711 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_SINK_MESSAGE);
1713 structure = GST_EVENT_STRUCTURE (event);
1716 GST_MESSAGE (g_value_dup_boxed (gst_structure_id_get_value
1717 (structure, GST_QUARK (MESSAGE))));
1721 * gst_event_new_stream_start:
1722 * @stream_id: Identifier for this stream
1724 * Create a new STREAM_START event. The stream start event can only
1725 * travel downstream synchronized with the buffer flow. It is expected
1726 * to be the first event that is sent for a new stream.
1728 * Source elements, demuxers and other elements that create new streams
1729 * are supposed to send this event as the first event of a new stream. It
1730 * should not be sent after a flushing seek or in similar situations
1731 * and is used to mark the beginning of a new logical stream. Elements
1732 * combining multiple streams must ensure that this event is only forwarded
1733 * downstream once and not for every single input stream.
1735 * The @stream_id should be a unique string that consists of the upstream
1736 * stream-id, / as separator and a unique stream-id for this specific
1737 * stream. A new stream-id should only be created for a stream if the upstream
1738 * stream is split into (potentially) multiple new streams, e.g. in a demuxer,
1739 * but not for every single element in the pipeline.
1740 * gst_pad_create_stream_id() or gst_pad_create_stream_id_printf() can be
1741 * used to create a stream-id. There are no particular semantics for the
1742 * stream-id, though it should be deterministic (to support stream matching)
1743 * and it might be used to order streams (besides any information conveyed by
1746 * Returns: (transfer full): the new STREAM_START event.
1749 gst_event_new_stream_start (const gchar * stream_id)
1753 g_return_val_if_fail (stream_id != NULL, NULL);
1755 s = gst_structure_new_id (GST_QUARK (EVENT_STREAM_START),
1756 GST_QUARK (STREAM_ID), G_TYPE_STRING, stream_id,
1757 GST_QUARK (FLAGS), GST_TYPE_STREAM_FLAGS, GST_STREAM_FLAG_NONE, NULL);
1759 return gst_event_new_custom (GST_EVENT_STREAM_START, s);
1763 * gst_event_parse_stream_start:
1764 * @event: a stream-start event.
1765 * @stream_id: (out) (optional) (transfer none): pointer to store the stream-id
1767 * Parse a stream-id @event and store the result in the given @stream_id
1768 * location. The string stored in @stream_id must not be modified and will
1769 * remain valid only until @event gets freed. Make a copy if you want to
1770 * modify it or store it for later use.
1773 gst_event_parse_stream_start (GstEvent * event, const gchar ** stream_id)
1775 const GstStructure *structure;
1778 g_return_if_fail (event != NULL);
1779 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STREAM_START);
1781 structure = gst_event_get_structure (event);
1782 val = gst_structure_id_get_value (structure, GST_QUARK (STREAM_ID));
1785 *stream_id = g_value_get_string (val);
1789 * gst_event_set_stream:
1790 * @event: a stream-start event
1791 * @stream: (transfer none): the stream object to set
1793 * Set the @stream on the stream-start @event
1798 gst_event_set_stream (GstEvent * event, GstStream * stream)
1800 g_return_if_fail (event != NULL);
1801 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STREAM_START);
1802 g_return_if_fail (gst_event_is_writable (event));
1804 gst_structure_id_set (GST_EVENT_STRUCTURE (event),
1805 GST_QUARK (STREAM), GST_TYPE_STREAM, stream, NULL);
1809 * gst_event_parse_stream:
1810 * @event: a stream-start event
1811 * @stream: (out) (optional) (transfer full): address of variable to store the stream
1813 * Parse a stream-start @event and extract the #GstStream from it.
1818 gst_event_parse_stream (GstEvent * event, GstStream ** stream)
1820 g_return_if_fail (event != NULL);
1821 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STREAM_START);
1825 gst_structure_id_get (GST_EVENT_STRUCTURE (event),
1826 GST_QUARK (STREAM), GST_TYPE_STREAM, stream, NULL);
1831 * gst_event_set_stream_flags:
1832 * @event: a stream-start event
1833 * @flags: the stream flags to set
1838 gst_event_set_stream_flags (GstEvent * event, GstStreamFlags flags)
1840 g_return_if_fail (event != NULL);
1841 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STREAM_START);
1842 g_return_if_fail (gst_event_is_writable (event));
1844 gst_structure_id_set (GST_EVENT_STRUCTURE (event),
1845 GST_QUARK (FLAGS), GST_TYPE_STREAM_FLAGS, flags, NULL);
1849 * gst_event_parse_stream_flags:
1850 * @event: a stream-start event
1851 * @flags: (out) (optional): address of variable where to store the stream flags
1856 gst_event_parse_stream_flags (GstEvent * event, GstStreamFlags * flags)
1858 g_return_if_fail (event != NULL);
1859 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STREAM_START);
1863 gst_structure_id_get (GST_EVENT_STRUCTURE (event),
1864 GST_QUARK (FLAGS), GST_TYPE_STREAM_FLAGS, flags, NULL);
1869 * gst_event_set_group_id:
1870 * @event: a stream-start event
1871 * @group_id: the group id to set
1873 * All streams that have the same group id are supposed to be played
1874 * together, i.e. all streams inside a container file should have the
1875 * same group id but different stream ids. The group id should change
1876 * each time the stream is started, resulting in different group ids
1877 * each time a file is played for example.
1879 * Use gst_util_group_id_next() to get a new group id.
1884 gst_event_set_group_id (GstEvent * event, guint group_id)
1886 g_return_if_fail (event != NULL);
1887 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STREAM_START);
1888 g_return_if_fail (gst_event_is_writable (event));
1889 g_return_if_fail (group_id != GST_GROUP_ID_INVALID);
1891 gst_structure_id_set (GST_EVENT_STRUCTURE (event),
1892 GST_QUARK (GROUP_ID), G_TYPE_UINT, group_id, NULL);
1896 * gst_event_parse_group_id:
1897 * @event: a stream-start event
1898 * @group_id: (out) (optional): address of variable where to store the group id
1900 * Returns: %TRUE if a group id was set on the event and could be parsed,
1906 gst_event_parse_group_id (GstEvent * event, guint * group_id)
1908 g_return_val_if_fail (event != NULL, FALSE);
1909 g_return_val_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STREAM_START,
1914 return gst_structure_id_get (GST_EVENT_STRUCTURE (event),
1915 GST_QUARK (GROUP_ID), G_TYPE_UINT, group_id, NULL);
1922 * gst_event_new_stream_collection:
1923 * @collection: Active collection for this data flow
1925 * Create a new STREAM_COLLECTION event. The stream collection event can only
1926 * travel downstream synchronized with the buffer flow.
1928 * Source elements, demuxers and other elements that manage collections
1929 * of streams and post #GstStreamCollection messages on the bus also send
1930 * this event downstream on each pad involved in the collection, so that
1931 * activation of a new collection can be tracked through the downstream
1934 * Returns: (transfer full): the new STREAM_COLLECTION event.
1939 gst_event_new_stream_collection (GstStreamCollection * collection)
1943 g_return_val_if_fail (collection != NULL, NULL);
1944 g_return_val_if_fail (GST_IS_STREAM_COLLECTION (collection), NULL);
1946 s = gst_structure_new_id (GST_QUARK (EVENT_STREAM_COLLECTION),
1947 GST_QUARK (COLLECTION), GST_TYPE_STREAM_COLLECTION, collection, NULL);
1949 return gst_event_new_custom (GST_EVENT_STREAM_COLLECTION, s);
1953 * gst_event_parse_stream_collection:
1954 * @event: a stream-collection event
1955 * @collection: (out) (optional): pointer to store the collection
1957 * Retrieve new #GstStreamCollection from STREAM_COLLECTION event @event.
1962 gst_event_parse_stream_collection (GstEvent * event,
1963 GstStreamCollection ** collection)
1965 const GstStructure *structure;
1967 g_return_if_fail (event != NULL);
1968 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STREAM_COLLECTION);
1970 structure = gst_event_get_structure (event);
1973 gst_structure_id_get (structure,
1974 GST_QUARK (COLLECTION), GST_TYPE_STREAM_COLLECTION, collection, NULL);
1979 * gst_event_new_toc:
1980 * @toc: (transfer none): #GstToc structure.
1981 * @updated: whether @toc was updated or not.
1983 * Generate a TOC event from the given @toc. The purpose of the TOC event is to
1984 * inform elements that some kind of the TOC was found.
1986 * Returns: (transfer full): a new #GstEvent.
1989 gst_event_new_toc (GstToc * toc, gboolean updated)
1991 GstStructure *toc_struct;
1994 g_return_val_if_fail (toc != NULL, NULL);
1996 GST_CAT_INFO (GST_CAT_EVENT, "creating toc event");
1998 /* need different structure names so sticky_multi event stuff on pads
1999 * works, i.e. both TOC events are kept around */
2000 if (gst_toc_get_scope (toc) == GST_TOC_SCOPE_GLOBAL)
2001 id = GST_QUARK (EVENT_TOC_GLOBAL);
2003 id = GST_QUARK (EVENT_TOC_CURRENT);
2005 toc_struct = gst_structure_new_id (id,
2006 GST_QUARK (TOC), GST_TYPE_TOC, toc,
2007 GST_QUARK (UPDATED), G_TYPE_BOOLEAN, updated, NULL);
2009 return gst_event_new_custom (GST_EVENT_TOC, toc_struct);
2013 * gst_event_parse_toc:
2014 * @event: a TOC event.
2015 * @toc: (out) (optional) (transfer full): pointer to #GstToc structure.
2016 * @updated: (out) (optional): pointer to store TOC updated flag.
2018 * Parse a TOC @event and store the results in the given @toc and @updated locations.
2021 gst_event_parse_toc (GstEvent * event, GstToc ** toc, gboolean * updated)
2023 const GstStructure *structure;
2025 g_return_if_fail (event != NULL);
2026 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_TOC);
2027 g_return_if_fail (toc != NULL);
2029 structure = gst_event_get_structure (event);
2031 gst_structure_id_get (structure,
2032 GST_QUARK (TOC), GST_TYPE_TOC, toc,
2033 GST_QUARK (UPDATED), G_TYPE_BOOLEAN, updated, NULL);
2037 * gst_event_new_toc_select:
2038 * @uid: UID in the TOC to start playback from.
2040 * Generate a TOC select event with the given @uid. The purpose of the
2041 * TOC select event is to start playback based on the TOC's entry with the
2044 * Returns: a new #GstEvent.
2047 gst_event_new_toc_select (const gchar * uid)
2049 GstStructure *structure;
2051 g_return_val_if_fail (uid != NULL, NULL);
2053 GST_CAT_INFO (GST_CAT_EVENT, "creating toc select event for UID: %s", uid);
2055 structure = gst_structure_new_id (GST_QUARK (EVENT_TOC_SELECT),
2056 GST_QUARK (UID), G_TYPE_STRING, uid, NULL);
2058 return gst_event_new_custom (GST_EVENT_TOC_SELECT, structure);
2062 * gst_event_parse_toc_select:
2063 * @event: a TOC select event.
2064 * @uid: (out) (transfer full) (optional): storage for the selection UID.
2066 * Parse a TOC select @event and store the results in the given @uid location.
2069 gst_event_parse_toc_select (GstEvent * event, gchar ** uid)
2071 const GstStructure *structure;
2074 g_return_if_fail (event != NULL);
2075 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_TOC_SELECT);
2077 structure = gst_event_get_structure (event);
2078 val = gst_structure_id_get_value (structure, GST_QUARK (UID));
2081 *uid = g_value_dup_string (val);
2086 * gst_event_new_protection:
2087 * @system_id: (transfer none): a string holding a UUID that uniquely
2088 * identifies a protection system.
2089 * @data: (transfer none): a #GstBuffer holding protection system specific
2090 * information. The reference count of the buffer will be incremented by one.
2091 * @origin: a string indicating where the protection
2092 * information carried in the event was extracted from. The allowed values
2093 * of this string will depend upon the protection scheme.
2095 * Creates a new event containing information specific to a particular
2096 * protection system (uniquely identified by @system_id), by which that
2097 * protection system can acquire key(s) to decrypt a protected stream.
2099 * In order for a decryption element to decrypt media
2100 * protected using a specific system, it first needs all the
2101 * protection system specific information necessary to acquire the decryption
2102 * key(s) for that stream. The functions defined here enable this information
2103 * to be passed in events from elements that extract it
2104 * (e.g., ISOBMFF demuxers, MPEG DASH demuxers) to protection decrypter
2105 * elements that use it.
2107 * Events containing protection system specific information are created using
2108 * #gst_event_new_protection, and they can be parsed by downstream elements
2109 * using #gst_event_parse_protection.
2111 * In Common Encryption, protection system specific information may be located
2112 * within ISOBMFF files, both in movie (moov) boxes and movie fragment (moof)
2113 * boxes; it may also be contained in ContentProtection elements within MPEG
2114 * DASH MPDs. The events created by #gst_event_new_protection contain data
2115 * identifying from which of these locations the encapsulated protection system
2116 * specific information originated. This origin information is required as
2117 * some protection systems use different encodings depending upon where the
2118 * information originates.
2120 * The events returned by gst_event_new_protection() are implemented
2121 * in such a way as to ensure that the most recently-pushed protection info
2122 * event of a particular @origin and @system_id will
2123 * be stuck to the output pad of the sending element.
2125 * Returns: (transfer full): a #GST_EVENT_PROTECTION event.
2130 gst_event_new_protection (const gchar * system_id,
2131 GstBuffer * data, const gchar * origin)
2137 g_return_val_if_fail (system_id != NULL, NULL);
2138 g_return_val_if_fail (data != NULL, NULL);
2141 g_strconcat ("GstProtectionEvent", origin ? "-" : "",
2142 origin ? origin : "", "-", system_id, NULL);
2144 GST_CAT_INFO (GST_CAT_EVENT, "creating protection event %s", event_name);
2146 s = gst_structure_new (event_name, "data", GST_TYPE_BUFFER, data,
2147 "system_id", G_TYPE_STRING, system_id, NULL);
2149 gst_structure_set (s, "origin", G_TYPE_STRING, origin, NULL);
2150 event = gst_event_new_custom (GST_EVENT_PROTECTION, s);
2152 g_free (event_name);
2157 * gst_event_parse_protection:
2158 * @event: a #GST_EVENT_PROTECTION event.
2159 * @system_id: (out) (optional) (transfer none): pointer to store the UUID
2160 * string uniquely identifying a content protection system.
2161 * @data: (out) (optional) (transfer none): pointer to store a #GstBuffer
2162 * holding protection system specific information.
2163 * @origin: (out) (optional) (transfer none): pointer to store a value that
2164 * indicates where the protection information carried by @event was extracted
2167 * Parses an event containing protection system specific information and stores
2168 * the results in @system_id, @data and @origin. The data stored in @system_id,
2169 * @origin and @data are valid until @event is released.
2174 gst_event_parse_protection (GstEvent * event, const gchar ** system_id,
2175 GstBuffer ** data, const gchar ** origin)
2177 const GstStructure *s;
2179 g_return_if_fail (event != NULL);
2180 g_return_if_fail (GST_IS_EVENT (event));
2181 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_PROTECTION);
2183 s = gst_event_get_structure (event);
2186 *origin = gst_structure_get_string (s, "origin");
2189 *system_id = gst_structure_get_string (s, "system_id");
2192 const GValue *value = gst_structure_get_value (s, "data");
2193 *data = gst_value_get_buffer (value);
2198 * gst_event_new_segment_done:
2199 * @format: The format of the position being done
2200 * @position: The position of the segment being done
2202 * Create a new segment-done event. This event is sent by elements that
2203 * finish playback of a segment as a result of a segment seek.
2205 * Returns: (transfer full): a new #GstEvent
2208 gst_event_new_segment_done (GstFormat format, gint64 position)
2211 GstStructure *structure;
2213 GST_CAT_INFO (GST_CAT_EVENT, "creating segment-done event");
2215 structure = gst_structure_new_id (GST_QUARK (EVENT_SEGMENT_DONE),
2216 GST_QUARK (FORMAT), GST_TYPE_FORMAT, format,
2217 GST_QUARK (POSITION), G_TYPE_INT64, position, NULL);
2219 event = gst_event_new_custom (GST_EVENT_SEGMENT_DONE, structure);
2225 * gst_event_parse_segment_done:
2226 * @event: A valid #GstEvent of type GST_EVENT_SEGMENT_DONE.
2227 * @format: (out) (optional): Result location for the format, or %NULL
2228 * @position: (out) (optional): Result location for the position, or %NULL
2230 * Extracts the position and format from the segment done message.
2234 gst_event_parse_segment_done (GstEvent * event, GstFormat * format,
2237 const GstStructure *structure;
2240 g_return_if_fail (event != NULL);
2241 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_SEGMENT_DONE);
2243 structure = gst_event_get_structure (event);
2245 val = gst_structure_id_get_value (structure, GST_QUARK (FORMAT));
2247 *format = g_value_get_enum (val);
2249 val = gst_structure_id_get_value (structure, GST_QUARK (POSITION));
2250 if (position != NULL)
2251 *position = g_value_get_int64 (val);
2255 * gst_event_new_instant_rate_change:
2256 * @rate_multiplier: the multiplier to be applied to the playback rate
2257 * @new_flags: A new subset of segment flags to replace in segments
2259 * Create a new instant-rate-change event. This event is sent by seek
2260 * handlers (e.g. demuxers) when receiving a seek with the
2261 * %GST_SEEK_FLAG_INSTANT_RATE_CHANGE and signals to downstream elements that
2262 * the playback rate in the existing segment should be immediately multiplied
2263 * by the @rate_multiplier factor.
2265 * The flags provided replace any flags in the existing segment, for the
2266 * flags within the %GST_SEGMENT_INSTANT_FLAGS set. Other GstSegmentFlags
2267 * are ignored and not transferred in the event.
2269 * Returns: (transfer full): the new instant-rate-change event.
2274 gst_event_new_instant_rate_change (gdouble rate_multiplier,
2275 GstSegmentFlags new_flags)
2279 g_return_val_if_fail (rate_multiplier != 0.0, NULL);
2281 new_flags &= GST_SEGMENT_INSTANT_FLAGS;
2283 GST_CAT_TRACE (GST_CAT_EVENT, "creating instant-rate-change event %lf %08x",
2284 rate_multiplier, new_flags);
2286 event = gst_event_new_custom (GST_EVENT_INSTANT_RATE_CHANGE,
2287 gst_structure_new_id (GST_QUARK (EVENT_INSTANT_RATE_CHANGE),
2288 GST_QUARK (RATE), G_TYPE_DOUBLE, rate_multiplier,
2289 GST_QUARK (FLAGS), GST_TYPE_SEGMENT_FLAGS, new_flags, NULL));
2295 * gst_event_parse_instant_rate_change:
2296 * @event: a #GstEvent of type #GST_EVENT_INSTANT_RATE_CHANGE
2297 * @rate_multiplier: (out) (optional): location in which to store the rate
2298 * multiplier of the instant-rate-change event, or %NULL
2299 * @new_flags: (out) (optional): location in which to store the new
2300 * segment flags of the instant-rate-change event, or %NULL
2302 * Extract rate and flags from an instant-rate-change event.
2307 gst_event_parse_instant_rate_change (GstEvent * event,
2308 gdouble * rate_multiplier, GstSegmentFlags * new_flags)
2310 GstStructure *structure;
2312 g_return_if_fail (GST_IS_EVENT (event));
2313 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_INSTANT_RATE_CHANGE);
2315 structure = GST_EVENT_STRUCTURE (event);
2316 gst_structure_id_get (structure, GST_QUARK (RATE), G_TYPE_DOUBLE,
2317 rate_multiplier, GST_QUARK (FLAGS), GST_TYPE_SEGMENT_FLAGS, new_flags,
2322 * gst_event_new_instant_rate_sync_time:
2323 * @rate_multiplier: the new playback rate multiplier to be applied
2324 * @running_time: Running time when the rate change should be applied
2325 * @upstream_running_time: The upstream-centric running-time when the
2326 * rate change should be applied.
2328 * Create a new instant-rate-sync-time event. This event is sent by the
2329 * pipeline to notify elements handling the instant-rate-change event about
2330 * the running-time when the new rate should be applied. The running time
2331 * may be in the past when elements handle this event, which can lead to
2332 * switching artifacts. The magnitude of those depends on the exact timing
2333 * of event delivery to each element and the magnitude of the change in
2334 * playback rate being applied.
2336 * The @running_time and @upstream_running_time are the same if this
2337 * is the first instant-rate adjustment, but will differ for later ones
2338 * to compensate for the accumulated offset due to playing at a rate
2339 * different to the one indicated in the playback segments.
2341 * Returns: (transfer full): the new instant-rate-sync-time event.
2346 gst_event_new_instant_rate_sync_time (gdouble rate_multiplier,
2347 GstClockTime running_time, GstClockTime upstream_running_time)
2351 g_return_val_if_fail (rate_multiplier != 0.0, NULL);
2352 g_return_val_if_fail (GST_CLOCK_TIME_IS_VALID (running_time), NULL);
2353 g_return_val_if_fail (GST_CLOCK_TIME_IS_VALID (upstream_running_time), NULL);
2355 GST_CAT_TRACE (GST_CAT_EVENT,
2356 "creating instant-rate-sync-time event %lf %" GST_TIME_FORMAT
2357 " %" GST_TIME_FORMAT, rate_multiplier,
2358 GST_TIME_ARGS (running_time), GST_TIME_ARGS (upstream_running_time));
2360 event = gst_event_new_custom (GST_EVENT_INSTANT_RATE_SYNC_TIME,
2361 gst_structure_new_id (GST_QUARK (EVENT_INSTANT_RATE_SYNC_TIME),
2362 GST_QUARK (RATE), G_TYPE_DOUBLE, rate_multiplier,
2363 GST_QUARK (RUNNING_TIME), GST_TYPE_CLOCK_TIME, running_time,
2364 GST_QUARK (UPSTREAM_RUNNING_TIME), GST_TYPE_CLOCK_TIME,
2365 upstream_running_time, NULL));
2371 * gst_event_parse_instant_rate_sync_time:
2372 * @event: a #GstEvent of type #GST_EVENT_INSTANT_RATE_CHANGE
2373 * @rate_multiplier: (out) (optional): location where to store the rate of
2374 * the instant-rate-sync-time event, or %NULL
2375 * @running_time: (out) (optional): location in which to store the running time
2376 * of the instant-rate-sync-time event, or %NULL
2377 * @upstream_running_time: (out) (optional): location in which to store the
2378 * upstream running time of the instant-rate-sync-time event, or %NULL
2380 * Extract the rate multiplier and running times from an instant-rate-sync-time event.
2385 gst_event_parse_instant_rate_sync_time (GstEvent * event,
2386 gdouble * rate_multiplier, GstClockTime * running_time,
2387 GstClockTime * upstream_running_time)
2389 GstStructure *structure;
2391 g_return_if_fail (GST_IS_EVENT (event));
2392 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_INSTANT_RATE_SYNC_TIME);
2394 structure = GST_EVENT_STRUCTURE (event);
2395 gst_structure_id_get (structure, GST_QUARK (RATE), G_TYPE_DOUBLE,
2396 rate_multiplier, GST_QUARK (RUNNING_TIME), GST_TYPE_CLOCK_TIME,
2397 running_time, GST_QUARK (UPSTREAM_RUNNING_TIME), GST_TYPE_CLOCK_TIME,
2398 upstream_running_time, NULL);
2402 * gst_event_replace: (skip)
2403 * @old_event: (inout) (transfer full) (nullable): pointer to a
2404 * pointer to a #GstEvent to be replaced.
2405 * @new_event: (nullable) (transfer none): pointer to a #GstEvent that will
2406 * replace the event pointed to by @old_event.
2408 * Modifies a pointer to a #GstEvent to point to a different #GstEvent. The
2409 * modification is done atomically (so this is useful for ensuring thread safety
2410 * in some cases), and the reference counts are updated appropriately (the old
2411 * event is unreffed, the new one is reffed).
2413 * Either @new_event or the #GstEvent pointed to by @old_event may be %NULL.
2415 * Returns: %TRUE if @new_event was different from @old_event
2418 gst_event_replace (GstEvent ** old_event, GstEvent * new_event)
2420 return gst_mini_object_replace ((GstMiniObject **) old_event,
2421 (GstMiniObject *) new_event);
2425 * gst_event_steal: (skip)
2426 * @old_event: (inout) (transfer full) (nullable): pointer to a
2427 * pointer to a #GstEvent to be stolen.
2429 * Atomically replace the #GstEvent pointed to by @old_event with %NULL and
2430 * return the original event.
2432 * Returns: the #GstEvent that was in @old_event
2435 gst_event_steal (GstEvent ** old_event)
2437 return GST_EVENT_CAST (gst_mini_object_steal ((GstMiniObject **) old_event));
2441 * gst_event_take: (skip)
2442 * @old_event: (inout) (transfer full) (nullable): pointer to a
2443 * pointer to a #GstEvent to be stolen.
2444 * @new_event: (nullable) (transfer full): pointer to a #GstEvent that will
2445 * replace the event pointed to by @old_event.
2447 * Modifies a pointer to a #GstEvent to point to a different #GstEvent. This
2448 * function is similar to gst_event_replace() except that it takes ownership of
2451 * Either @new_event or the #GstEvent pointed to by @old_event may be %NULL.
2453 * Returns: %TRUE if @new_event was different from @old_event
2456 gst_event_take (GstEvent ** old_event, GstEvent * new_event)
2458 return gst_mini_object_take ((GstMiniObject **) old_event,
2459 (GstMiniObject *) new_event);
2463 * gst_event_ref: (skip)
2464 * @event: The event to refcount
2466 * Increase the refcount of this event.
2468 * Returns: (transfer full): @event (for convenience when doing assignments)
2471 gst_event_ref (GstEvent * event)
2473 return (GstEvent *) gst_mini_object_ref (GST_MINI_OBJECT_CAST (event));
2477 * gst_event_unref: (skip)
2478 * @event: (transfer full): the event to refcount
2480 * Decrease the refcount of an event, freeing it if the refcount reaches 0.
2483 gst_event_unref (GstEvent * event)
2485 gst_mini_object_unref (GST_MINI_OBJECT_CAST (event));
2489 * gst_clear_event: (skip)
2490 * @event_ptr: a pointer to a #GstEvent reference
2492 * Clears a reference to a #GstEvent.
2494 * @event_ptr must not be %NULL.
2496 * If the reference is %NULL then this function does nothing. Otherwise, the
2497 * reference count of the event is decreased and the pointer is set to %NULL.
2502 gst_clear_event (GstEvent ** event_ptr)
2504 gst_clear_mini_object ((GstMiniObject **) event_ptr);
2508 * gst_event_copy: (skip)
2509 * @event: The event to copy
2511 * Copy the event using the event specific copy function.
2513 * Returns: (transfer full): the new event
2516 gst_event_copy (const GstEvent * event)
2519 GST_EVENT_CAST (gst_mini_object_copy (GST_MINI_OBJECT_CONST_CAST