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., 59 Temple Place - Suite 330,
21 * Boston, MA 02111-1307, 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.
55 * <title>performing a seek on a pipeline</title>
60 * // construct a seek event to play the media from second 2 to 5, flush
61 * // the pipeline to decrease latency.
62 * event = gst_event_new_seek (1.0,
64 * GST_SEEK_FLAG_FLUSH,
65 * GST_SEEK_TYPE_SET, 2 * GST_SECOND,
66 * GST_SEEK_TYPE_SET, 5 * GST_SECOND);
68 * result = gst_element_send_event (pipeline, event);
70 * g_warning ("seek failed");
75 * Last reviewed on 2012-03-28 (0.11.3)
79 #include "gst_private.h"
80 #include <string.h> /* memcpy */
84 #include "gstenumtypes.h"
89 GType _gst_event_type = 0;
95 GstStructure *structure;
98 #define GST_EVENT_STRUCTURE(e) (((GstEventImpl *)(e))->structure)
107 static GstEventQuarks event_quarks[] = {
108 {GST_EVENT_UNKNOWN, "unknown", 0},
109 {GST_EVENT_FLUSH_START, "flush-start", 0},
110 {GST_EVENT_FLUSH_STOP, "flush-stop", 0},
111 {GST_EVENT_STREAM_START, "stream-start", 0},
112 {GST_EVENT_CAPS, "caps", 0},
113 {GST_EVENT_STREAM_CONFIG, "stream-config", 0},
114 {GST_EVENT_SEGMENT, "segment", 0},
115 {GST_EVENT_TAG, "tag", 0},
116 {GST_EVENT_TOC, "toc", 0},
117 {GST_EVENT_BUFFERSIZE, "buffersize", 0},
118 {GST_EVENT_SINK_MESSAGE, "sink-message", 0},
119 {GST_EVENT_EOS, "eos", 0},
120 {GST_EVENT_SEGMENT_DONE, "segment-done", 0},
121 {GST_EVENT_GAP, "gap", 0},
122 {GST_EVENT_QOS, "qos", 0},
123 {GST_EVENT_SEEK, "seek", 0},
124 {GST_EVENT_NAVIGATION, "navigation", 0},
125 {GST_EVENT_LATENCY, "latency", 0},
126 {GST_EVENT_STEP, "step", 0},
127 {GST_EVENT_RECONFIGURE, "reconfigure", 0},
128 {GST_EVENT_TOC_SELECT, "toc-select", 0},
129 {GST_EVENT_CUSTOM_UPSTREAM, "custom-upstream", 0},
130 {GST_EVENT_CUSTOM_DOWNSTREAM, "custom-downstream", 0},
131 {GST_EVENT_CUSTOM_DOWNSTREAM_OOB, "custom-downstream-oob", 0},
132 {GST_EVENT_CUSTOM_DOWNSTREAM_STICKY, "custom-downstream-sticky", 0},
133 {GST_EVENT_CUSTOM_BOTH, "custom-both", 0},
134 {GST_EVENT_CUSTOM_BOTH_OOB, "custom-both-oob", 0},
139 GST_DEFINE_MINI_OBJECT_TYPE (GstEvent, gst_event);
142 _priv_gst_event_initialize (void)
146 _gst_event_type = gst_event_get_type ();
148 g_type_class_ref (gst_seek_flags_get_type ());
149 g_type_class_ref (gst_seek_type_get_type ());
151 for (i = 0; event_quarks[i].name; i++) {
152 event_quarks[i].quark = g_quark_from_static_string (event_quarks[i].name);
157 * gst_event_type_get_name:
158 * @type: the event type
160 * Get a printable name for the given event type. Do not modify or free.
162 * Returns: a reference to the static name of the event.
165 gst_event_type_get_name (GstEventType type)
169 for (i = 0; event_quarks[i].name; i++) {
170 if (type == event_quarks[i].type)
171 return event_quarks[i].name;
177 * gst_event_type_to_quark:
178 * @type: the event type
180 * Get the unique quark for the given event type.
182 * Returns: the quark associated with the event type
185 gst_event_type_to_quark (GstEventType type)
189 for (i = 0; event_quarks[i].name; i++) {
190 if (type == event_quarks[i].type)
191 return event_quarks[i].quark;
197 * gst_event_type_get_flags:
198 * @type: a #GstEventType
200 * Gets the #GstEventTypeFlags associated with @type.
202 * Returns: a #GstEventTypeFlags.
205 gst_event_type_get_flags (GstEventType type)
207 GstEventTypeFlags ret;
209 ret = type & ((1 << GST_EVENT_NUM_SHIFT) - 1);
215 _gst_event_free (GstEvent * event)
219 g_return_if_fail (event != NULL);
220 g_return_if_fail (GST_IS_EVENT (event));
222 GST_CAT_LOG (GST_CAT_EVENT, "freeing event %p type %s", event,
223 GST_EVENT_TYPE_NAME (event));
225 s = GST_EVENT_STRUCTURE (event);
228 gst_structure_set_parent_refcount (s, NULL);
229 gst_structure_free (s);
232 g_slice_free1 (GST_MINI_OBJECT_SIZE (event), event);
235 static void gst_event_init (GstEventImpl * event, gsize size,
239 _gst_event_copy (GstEvent * event)
244 copy = g_slice_new0 (GstEventImpl);
246 gst_event_init (copy, sizeof (GstEventImpl), GST_EVENT_TYPE (event));
248 GST_EVENT_TIMESTAMP (copy) = GST_EVENT_TIMESTAMP (event);
249 GST_EVENT_SEQNUM (copy) = GST_EVENT_SEQNUM (event);
251 s = GST_EVENT_STRUCTURE (event);
253 GST_EVENT_STRUCTURE (copy) = gst_structure_copy (s);
254 gst_structure_set_parent_refcount (GST_EVENT_STRUCTURE (copy),
255 ©->event.mini_object.refcount);
257 GST_EVENT_STRUCTURE (copy) = NULL;
259 return GST_EVENT_CAST (copy);
263 gst_event_init (GstEventImpl * event, gsize size, GstEventType type)
265 gst_mini_object_init (GST_MINI_OBJECT_CAST (event), _gst_event_type, size);
267 event->event.mini_object.copy = (GstMiniObjectCopyFunction) _gst_event_copy;
268 event->event.mini_object.free = (GstMiniObjectFreeFunction) _gst_event_free;
270 GST_EVENT_TYPE (event) = type;
271 GST_EVENT_TIMESTAMP (event) = GST_CLOCK_TIME_NONE;
272 GST_EVENT_SEQNUM (event) = gst_util_seqnum_next ();
277 * gst_event_new_custom:
278 * @type: The type of the new event
279 * @structure: (transfer full): the structure for the event. The event will
280 * take ownership of the structure.
282 * Create a new custom-typed event. This can be used for anything not
283 * handled by other event-specific functions to pass an event to another
286 * Make sure to allocate an event type with the #GST_EVENT_MAKE_TYPE macro,
287 * assigning a free number and filling in the correct direction and
288 * serialization flags.
290 * New custom events can also be created by subclassing the event type if
293 * Returns: (transfer full): the new custom event.
296 gst_event_new_custom (GstEventType type, GstStructure * structure)
300 event = g_slice_new0 (GstEventImpl);
302 GST_CAT_DEBUG (GST_CAT_EVENT, "creating new event %p %s %d", event,
303 gst_event_type_get_name (type), type);
306 /* structure must not have a parent */
307 if (!gst_structure_set_parent_refcount (structure,
308 &event->event.mini_object.refcount))
312 gst_event_init (event, sizeof (GstEventImpl), type);
314 GST_EVENT_STRUCTURE (event) = structure;
316 return GST_EVENT_CAST (event);
321 g_slice_free1 (GST_MINI_OBJECT_SIZE (event), event);
322 g_warning ("structure is already owned by another object");
328 * gst_event_get_structure:
329 * @event: The #GstEvent.
331 * Access the structure of the event.
333 * Returns: The structure of the event. The structure is still
334 * owned by the event, which means that you should not free it and
335 * that the pointer becomes invalid when you free the event.
340 gst_event_get_structure (GstEvent * event)
342 g_return_val_if_fail (GST_IS_EVENT (event), NULL);
344 return GST_EVENT_STRUCTURE (event);
348 * gst_event_writable_structure:
349 * @event: The #GstEvent.
351 * Get a writable version of the structure.
353 * Returns: The structure of the event. The structure is still
354 * owned by the event, which means that you should not free it and
355 * that the pointer becomes invalid when you free the event.
356 * This function checks if @event is writable and will never return NULL.
361 gst_event_writable_structure (GstEvent * event)
363 GstStructure *structure;
365 g_return_val_if_fail (GST_IS_EVENT (event), NULL);
366 g_return_val_if_fail (gst_event_is_writable (event), NULL);
368 structure = GST_EVENT_STRUCTURE (event);
370 if (structure == NULL) {
372 gst_structure_new_id_empty (gst_event_type_to_quark (GST_EVENT_TYPE
374 gst_structure_set_parent_refcount (structure, &event->mini_object.refcount);
375 GST_EVENT_STRUCTURE (event) = structure;
381 * gst_event_has_name:
382 * @event: The #GstEvent.
383 * @name: name to check
385 * Checks if @event has the given @name. This function is usually used to
386 * check the name of a custom event.
388 * Returns: %TRUE if @name matches the name of the event structure.
393 gst_event_has_name (GstEvent * event, const gchar * name)
395 g_return_val_if_fail (GST_IS_EVENT (event), FALSE);
397 if (GST_EVENT_STRUCTURE (event) == NULL)
400 return gst_structure_has_name (GST_EVENT_STRUCTURE (event), name);
404 * gst_event_get_seqnum:
405 * @event: A #GstEvent.
407 * Retrieve the sequence number of a event.
409 * Events have ever-incrementing sequence numbers, which may also be set
410 * explicitly via gst_event_set_seqnum(). Sequence numbers are typically used to
411 * indicate that a event corresponds to some other set of events or messages,
412 * for example an EOS event corresponding to a SEEK event. It is considered good
413 * practice to make this correspondence when possible, though it is not
416 * Note that events and messages share the same sequence number incrementor;
417 * two events or messages will never have the same sequence number unless
418 * that correspondence was made explicitly.
420 * Returns: The event's sequence number.
427 gst_event_get_seqnum (GstEvent * event)
429 g_return_val_if_fail (GST_IS_EVENT (event), -1);
431 return GST_EVENT_SEQNUM (event);
435 * gst_event_set_seqnum:
436 * @event: A #GstEvent.
437 * @seqnum: A sequence number.
439 * Set the sequence number of a event.
441 * This function might be called by the creator of a event to indicate that the
442 * event relates to other events or messages. See gst_event_get_seqnum() for
450 gst_event_set_seqnum (GstEvent * event, guint32 seqnum)
452 g_return_if_fail (GST_IS_EVENT (event));
454 GST_EVENT_SEQNUM (event) = seqnum;
458 * gst_event_new_flush_start:
460 * Allocate a new flush start event. The flush start event can be sent
461 * upstream and downstream and travels out-of-bounds with the dataflow.
463 * It marks pads as being flushing and will make them return
464 * #GST_FLOW_FLUSHING when used for data flow with gst_pad_push(),
465 * gst_pad_chain(), gst_pad_get_range() and gst_pad_pull_range().
466 * Any event (except a #GST_EVENT_FLUSH_STOP) received
467 * on a flushing pad will return %FALSE immediately.
469 * Elements should unlock any blocking functions and exit their streaming
470 * functions as fast as possible when this event is received.
472 * This event is typically generated after a seek to flush out all queued data
473 * in the pipeline so that the new media is played as soon as possible.
475 * Returns: (transfer full): a new flush start event.
478 gst_event_new_flush_start (void)
480 return gst_event_new_custom (GST_EVENT_FLUSH_START, NULL);
484 * gst_event_new_flush_stop:
485 * @reset_time: if time should be reset
487 * Allocate a new flush stop event. The flush stop event can be sent
488 * upstream and downstream and travels serialized with the dataflow.
489 * It is typically sent after sending a FLUSH_START event to make the
490 * pads accept data again.
492 * Elements can process this event synchronized with the dataflow since
493 * the preceeding FLUSH_START event stopped the dataflow.
495 * This event is typically generated to complete a seek and to resume
498 * Returns: (transfer full): a new flush stop event.
501 gst_event_new_flush_stop (gboolean reset_time)
505 GST_CAT_INFO (GST_CAT_EVENT, "creating flush stop %d", reset_time);
507 event = gst_event_new_custom (GST_EVENT_FLUSH_STOP,
508 gst_structure_new_id (GST_QUARK (EVENT_FLUSH_STOP),
509 GST_QUARK (RESET_TIME), G_TYPE_BOOLEAN, reset_time, NULL));
515 * gst_event_parse_flush_stop:
516 * @event: The event to parse
517 * @reset_time: (out): if time should be reset
519 * Parse the FLUSH_STOP event and retrieve the @reset_time member.
522 gst_event_parse_flush_stop (GstEvent * event, gboolean * reset_time)
524 GstStructure *structure;
526 g_return_if_fail (GST_IS_EVENT (event));
527 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_FLUSH_STOP);
529 structure = GST_EVENT_STRUCTURE (event);
530 if (G_LIKELY (reset_time))
532 g_value_get_boolean (gst_structure_id_get_value (structure,
533 GST_QUARK (RESET_TIME)));
539 * Create a new EOS event. The eos event can only travel downstream
540 * synchronized with the buffer flow. Elements that receive the EOS
541 * event on a pad can return #GST_FLOW_EOS as a #GstFlowReturn
542 * when data after the EOS event arrives.
544 * The EOS event will travel down to the sink elements in the pipeline
545 * which will then post the #GST_MESSAGE_EOS on the bus after they have
546 * finished playing any buffered data.
548 * When all sinks have posted an EOS message, an EOS message is
549 * forwarded to the application.
551 * The EOS event itself will not cause any state transitions of the pipeline.
553 * Returns: (transfer full): the new EOS event.
556 gst_event_new_eos (void)
558 return gst_event_new_custom (GST_EVENT_EOS, NULL);
563 * @timestamp: the start time (pts) of the gap
564 * @duration: the duration of the gap
566 * Create a new GAP event. A gap event can be thought of as conceptually
567 * equivalent to a buffer to signal that there is no data for a certain
568 * amount of time. This is useful to signal a gap to downstream elements
569 * which may wait for data, such as muxers or mixers or overlays, especially
570 * for sparse streams such as subtitle streams.
572 * Returns: (transfer full): the new GAP event.
575 gst_event_new_gap (GstClockTime timestamp, GstClockTime duration)
579 g_return_val_if_fail (GST_CLOCK_TIME_IS_VALID (timestamp), NULL);
580 g_return_val_if_fail (GST_CLOCK_TIME_IS_VALID (duration), NULL);
582 GST_CAT_TRACE (GST_CAT_EVENT, "creating gap %" GST_TIME_FORMAT " - "
583 "%" GST_TIME_FORMAT " (duration: %" GST_TIME_FORMAT ")",
584 GST_TIME_ARGS (timestamp), GST_TIME_ARGS (timestamp + duration),
585 GST_TIME_ARGS (duration));
587 event = gst_event_new_custom (GST_EVENT_GAP,
588 gst_structure_new_id (GST_QUARK (EVENT_GAP),
589 GST_QUARK (TIMESTAMP), GST_TYPE_CLOCK_TIME, timestamp,
590 GST_QUARK (DURATION), GST_TYPE_CLOCK_TIME, duration, NULL));
596 * gst_event_parse_gap:
597 * @event: a #GstEvent of type #GST_EVENT_GAP
598 * @timestamp: (out) (allow-none): location where to store the
599 * start time (pts) of the gap, or %NULL
600 * @duration: (out) (allow-none): location where to store the duration of
603 * Extract timestamp and duration from a new GAP event.
606 gst_event_parse_gap (GstEvent * event, GstClockTime * timestamp,
607 GstClockTime * duration)
609 GstStructure *structure;
611 g_return_if_fail (GST_IS_EVENT (event));
612 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_GAP);
614 structure = GST_EVENT_STRUCTURE (event);
615 gst_structure_id_get (structure,
616 GST_QUARK (TIMESTAMP), GST_TYPE_CLOCK_TIME, timestamp,
617 GST_QUARK (DURATION), GST_TYPE_CLOCK_TIME, duration, NULL);
621 * gst_event_new_caps:
622 * @caps: (transfer none): a #GstCaps
624 * Create a new CAPS event for @caps. The caps event can only travel downstream
625 * synchronized with the buffer flow and contains the format of the buffers
626 * that will follow after the event.
628 * Returns: (transfer full): the new CAPS event.
631 gst_event_new_caps (GstCaps * caps)
635 g_return_val_if_fail (caps != NULL, NULL);
636 g_return_val_if_fail (gst_caps_is_fixed (caps), NULL);
638 GST_CAT_INFO (GST_CAT_EVENT, "creating caps event %" GST_PTR_FORMAT, caps);
640 event = gst_event_new_custom (GST_EVENT_CAPS,
641 gst_structure_new_id (GST_QUARK (EVENT_CAPS),
642 GST_QUARK (CAPS), GST_TYPE_CAPS, caps, NULL));
648 * gst_event_parse_caps:
649 * @event: The event to parse
650 * @caps: (out): A pointer to the caps
652 * Get the caps from @event. The caps remains valid as long as @event remains
656 gst_event_parse_caps (GstEvent * event, GstCaps ** caps)
658 GstStructure *structure;
660 g_return_if_fail (GST_IS_EVENT (event));
661 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_CAPS);
663 structure = GST_EVENT_STRUCTURE (event);
666 g_value_get_boxed (gst_structure_id_get_value (structure,
671 * gst_event_new_stream_config:
672 * @flags: the stream config flags
674 * Create a new STREAM CONFIG event. The stream config event travels
675 * downstream synchronized with the buffer flow and contains stream
676 * configuration information for the stream, such as stream-headers
677 * or setup-data. It is optional and should be sent after the CAPS
680 * Returns: (transfer full): the new STREAM CONFIG event.
683 gst_event_new_stream_config (GstStreamConfigFlags flags)
687 GST_CAT_INFO (GST_CAT_EVENT, "creating stream info event, flags=0x%x", flags);
689 event = gst_event_new_custom (GST_EVENT_STREAM_CONFIG,
690 gst_structure_new_id (GST_QUARK (EVENT_STREAM_CONFIG),
691 GST_QUARK (FLAGS), GST_TYPE_STREAM_CONFIG_FLAGS, flags, NULL));
697 * gst_event_parse_stream_config:
698 * @event: The event to parse
699 * @flags: (out): a pointer to a variable to store the stream config flags
701 * Get the stream config flags from @event.
704 gst_event_parse_stream_config (GstEvent * event, GstStreamConfigFlags * flags)
706 GstStructure *structure;
708 g_return_if_fail (GST_IS_EVENT (event));
709 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STREAM_CONFIG);
711 structure = GST_EVENT_STRUCTURE (event);
712 if (G_LIKELY (flags != NULL)) {
714 g_value_get_enum (gst_structure_id_get_value (structure,
720 * gst_event_set_stream_config_setup_data:
721 * @event: a stream config event
722 * @buf: a #GstBuffer with setup data
724 * Set setup data on the stream info event to signal out of bound setup data
725 * to downstream elements. Unlike stream headers, setup data contains data
726 * that is required to interpret the data stream, but is not valid as-is
727 * inside the data stream and thus can't just be prepended to or inserted
728 * into the data stream.
731 gst_event_set_stream_config_setup_data (GstEvent * event, GstBuffer * buf)
735 g_return_if_fail (GST_IS_EVENT (event));
736 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STREAM_CONFIG);
737 g_return_if_fail (GST_IS_BUFFER (buf) && gst_buffer_get_size (buf) > 0);
739 s = GST_EVENT_STRUCTURE (event);
740 gst_structure_id_set (s, GST_QUARK (SETUP_DATA), GST_TYPE_BUFFER, buf, NULL);
744 * gst_event_parse_stream_config_setup_data:
745 * @event: a stream config event
746 * @buf: (out) (transfer none): location where to store the #GstBuffer with setup data
748 * Extracts the setup data buffer from the stream info event. Will store
749 * %NULL in @buf if the event contains no setup data. The buffer returned
750 * will remain valid as long as @event remains valid. The caller should
751 * acquire a reference to to @buf if needed.
753 * Returns: TRUE if @event contained setup data and @buf has been set,
757 gst_event_parse_stream_config_setup_data (GstEvent * event, GstBuffer ** buf)
762 g_return_val_if_fail (GST_IS_EVENT (event), FALSE);
763 g_return_val_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STREAM_CONFIG,
765 g_return_val_if_fail (buf != NULL, FALSE);
767 s = GST_EVENT_STRUCTURE (event);
768 val = gst_structure_id_get_value (s, GST_QUARK (SETUP_DATA));
770 *buf = g_value_get_boxed (val);
774 return (*buf != NULL);
778 * gst_event_add_stream_config_header:
779 * @event: a stream config event
780 * @buf: a #GstBuffer with stream header data
782 * Adds a stream header to the stream info event to signal stream headers to
783 * to downstream elements such as multifilesink, tcpserversink etc. Stream
784 * headers can be and should usually be prepended to the data stream at any
785 * point in the stream (which requires a streamable format), e.g. to a new
786 * client connecting, or when starting a new file segment. stream header
787 * buffers will all be used together in the order they were added to the
788 * stream config event. Stream headers are sent as buffers at the beginning
789 * of the data flow in addition to the stream config event. Elements that
790 * care about stream headers need to make sure that they don't insert or
791 * interpret these header buffers twice if they interpret them.
794 gst_event_add_stream_config_header (GstEvent * event, GstBuffer * buf)
797 GValue buf_val = { 0, };
800 g_return_if_fail (GST_IS_EVENT (event));
801 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STREAM_CONFIG);
802 g_return_if_fail (GST_IS_BUFFER (buf) && gst_buffer_get_size (buf) > 0);
804 g_value_init (&buf_val, GST_TYPE_BUFFER);
805 g_value_set_boxed (&buf_val, buf);
807 s = GST_EVENT_STRUCTURE (event);
808 val = (GValue *) gst_structure_id_get_value (s, GST_QUARK (STREAM_HEADERS));
810 GValue new_array = { 0, };
812 g_value_init (&new_array, GST_TYPE_ARRAY);
813 gst_value_array_append_value (&new_array, &buf_val);
814 gst_structure_id_take_value (s, GST_QUARK (STREAM_HEADERS), &new_array);
816 gst_value_array_append_value (val, &buf_val);
818 g_value_unset (&buf_val);
822 * gst_event_get_n_stream_config_headers:
823 * @event: a stream config event
825 * Extract the number of stream header buffers.
827 * Returns: the number of stream header buffers attached to the stream info
831 gst_event_get_n_stream_config_headers (GstEvent * event)
837 g_return_val_if_fail (GST_IS_EVENT (event), 0);
838 g_return_val_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STREAM_CONFIG, 0);
840 s = GST_EVENT_STRUCTURE (event);
841 val = gst_structure_id_get_value (s, GST_QUARK (STREAM_HEADERS));
844 num = gst_value_array_get_size (val);
850 * gst_event_parse_nth_stream_config_header:
851 * @event: a stream config event
852 * @index: number of the stream header to retrieve
853 * @buf: (out) (transfer none): location where to store the n-th stream
856 * Retrieves the n-th stream header buffer attached to the stream config
857 * event and stores it in @buf. Will store %NULL in @buf if there is no such
860 * Returns: TRUE if @event contained a stream header at @index and @buf has
861 * been set, otherwise FALSE.
864 gst_event_parse_nth_stream_config_header (GstEvent * event, guint index,
867 const GValue *val, *buf_val;
869 GstBuffer *ret = NULL;
871 g_return_val_if_fail (GST_IS_EVENT (event), FALSE);
872 g_return_val_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STREAM_CONFIG,
874 g_return_val_if_fail (buf != NULL, FALSE);
876 s = GST_EVENT_STRUCTURE (event);
877 val = gst_structure_id_get_value (s, GST_QUARK (STREAM_HEADERS));
880 buf_val = gst_value_array_get_value (val, index);
882 ret = g_value_get_boxed (buf_val);
886 return (ret != NULL);
890 * gst_event_new_segment:
891 * @segment: (transfer none): a #GstSegment
893 * Create a new SEGMENT event for @segment. The segment event can only travel
894 * downstream synchronized with the buffer flow and contains timing information
895 * and playback properties for the buffers that will follow.
897 * The newsegment event marks the range of buffers to be processed. All
898 * data not within the segment range is not to be processed. This can be
899 * used intelligently by plugins to apply more efficient methods of skipping
900 * unneeded data. The valid range is expressed with the @start and @stop
903 * The time value of the segment is used in conjunction with the start
904 * value to convert the buffer timestamps into the stream time. This is
905 * usually done in sinks to report the current stream_time.
906 * @time represents the stream_time of a buffer carrying a timestamp of
907 * @start. @time cannot be -1.
909 * @start cannot be -1, @stop can be -1. If there
910 * is a valid @stop given, it must be greater or equal the @start, including
911 * when the indicated playback @rate is < 0.
913 * The @applied_rate value provides information about any rate adjustment that
914 * has already been made to the timestamps and content on the buffers of the
915 * stream. (@rate * @applied_rate) should always equal the rate that has been
916 * requested for playback. For example, if an element has an input segment
917 * with intended playback @rate of 2.0 and applied_rate of 1.0, it can adjust
918 * incoming timestamps and buffer content by half and output a newsegment event
919 * with @rate of 1.0 and @applied_rate of 2.0
921 * After a newsegment event, the buffer stream time is calculated with:
923 * time + (TIMESTAMP(buf) - start) * ABS (rate * applied_rate)
925 * Returns: (transfer full): the new SEGMENT event.
928 gst_event_new_segment (const GstSegment * segment)
932 g_return_val_if_fail (segment != NULL, NULL);
933 g_return_val_if_fail (segment->rate != 0.0, NULL);
934 g_return_val_if_fail (segment->applied_rate != 0.0, NULL);
935 g_return_val_if_fail (segment->format != GST_FORMAT_UNDEFINED, NULL);
937 GST_CAT_INFO (GST_CAT_EVENT, "creating segment event %" GST_SEGMENT_FORMAT,
940 event = gst_event_new_custom (GST_EVENT_SEGMENT,
941 gst_structure_new_id (GST_QUARK (EVENT_SEGMENT),
942 GST_QUARK (SEGMENT), GST_TYPE_SEGMENT, segment, NULL));
948 * gst_event_parse_segment:
949 * @event: The event to parse
950 * @segment: (out) (transfer none): a pointer to a #GstSegment
952 * Parses a segment @event and stores the result in the given @segment location.
953 * @segment remains valid only until the @event is freed. Don't modify the segment
954 * and make a copy if you want to modify it or store it for later use.
957 gst_event_parse_segment (GstEvent * event, const GstSegment ** segment)
959 GstStructure *structure;
961 g_return_if_fail (GST_IS_EVENT (event));
962 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_SEGMENT);
965 structure = GST_EVENT_STRUCTURE (event);
966 *segment = g_value_get_boxed (gst_structure_id_get_value (structure,
967 GST_QUARK (SEGMENT)));
972 * gst_event_copy_segment:
973 * @event: The event to parse
974 * @segment: a pointer to a #GstSegment
976 * Parses a segment @event and copies the #GstSegment into the location
980 gst_event_copy_segment (GstEvent * event, GstSegment * segment)
982 const GstSegment *src;
984 g_return_if_fail (GST_IS_EVENT (event));
985 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_SEGMENT);
988 gst_event_parse_segment (event, &src);
989 gst_segment_copy_into (src, segment);
995 * @taglist: (transfer full): metadata list. The event will take ownership
998 * Generates a metadata tag event from the given @taglist.
1000 * Returns: (transfer full): a new #GstEvent
1003 gst_event_new_tag (GstTagList * taglist)
1006 GValue val = G_VALUE_INIT;
1008 g_return_val_if_fail (taglist != NULL, NULL);
1010 s = gst_structure_new_id_empty (GST_QUARK (EVENT_TAG));
1011 g_value_init (&val, GST_TYPE_TAG_LIST);
1012 g_value_take_boxed (&val, taglist);
1013 gst_structure_id_take_value (s, GST_QUARK (TAGLIST), &val);
1014 return gst_event_new_custom (GST_EVENT_TAG, s);
1018 * gst_event_parse_tag:
1019 * @event: a tag event
1020 * @taglist: (out) (transfer none): pointer to metadata list
1022 * Parses a tag @event and stores the results in the given @taglist location.
1023 * No reference to the taglist will be returned, it remains valid only until
1024 * the @event is freed. Don't modify or free the taglist, make a copy if you
1025 * want to modify it or store it for later use.
1028 gst_event_parse_tag (GstEvent * event, GstTagList ** taglist)
1032 g_return_if_fail (GST_IS_EVENT (event));
1033 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_TAG);
1035 val = gst_structure_id_get_value (GST_EVENT_STRUCTURE (event),
1036 GST_QUARK (TAGLIST));
1039 *taglist = (GstTagList *) g_value_get_boxed (val);
1042 /* buffersize event */
1044 * gst_event_new_buffer_size:
1045 * @format: buffer format
1046 * @minsize: minimum buffer size
1047 * @maxsize: maximum buffer size
1048 * @async: thread behavior
1050 * Create a new buffersize event. The event is sent downstream and notifies
1051 * elements that they should provide a buffer of the specified dimensions.
1053 * When the @async flag is set, a thread boundary is preferred.
1055 * Returns: (transfer full): a new #GstEvent
1058 gst_event_new_buffer_size (GstFormat format, gint64 minsize,
1059 gint64 maxsize, gboolean async)
1062 GstStructure *structure;
1064 GST_CAT_INFO (GST_CAT_EVENT,
1065 "creating buffersize format %s, minsize %" G_GINT64_FORMAT
1066 ", maxsize %" G_GINT64_FORMAT ", async %d", gst_format_get_name (format),
1067 minsize, maxsize, async);
1069 structure = gst_structure_new_id (GST_QUARK (EVENT_BUFFER_SIZE),
1070 GST_QUARK (FORMAT), GST_TYPE_FORMAT, format,
1071 GST_QUARK (MINSIZE), G_TYPE_INT64, minsize,
1072 GST_QUARK (MAXSIZE), G_TYPE_INT64, maxsize,
1073 GST_QUARK (ASYNC), G_TYPE_BOOLEAN, async, NULL);
1074 event = gst_event_new_custom (GST_EVENT_BUFFERSIZE, structure);
1080 * gst_event_parse_buffer_size:
1081 * @event: The event to query
1082 * @format: (out): A pointer to store the format in
1083 * @minsize: (out): A pointer to store the minsize in
1084 * @maxsize: (out): A pointer to store the maxsize in
1085 * @async: (out): A pointer to store the async-flag in
1087 * Get the format, minsize, maxsize and async-flag in the buffersize event.
1090 gst_event_parse_buffer_size (GstEvent * event, GstFormat * format,
1091 gint64 * minsize, gint64 * maxsize, gboolean * async)
1093 const GstStructure *structure;
1095 g_return_if_fail (GST_IS_EVENT (event));
1096 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_BUFFERSIZE);
1098 structure = GST_EVENT_STRUCTURE (event);
1100 *format = (GstFormat)
1101 g_value_get_enum (gst_structure_id_get_value (structure,
1102 GST_QUARK (FORMAT)));
1105 g_value_get_int64 (gst_structure_id_get_value (structure,
1106 GST_QUARK (MINSIZE)));
1109 g_value_get_int64 (gst_structure_id_get_value (structure,
1110 GST_QUARK (MAXSIZE)));
1113 g_value_get_boolean (gst_structure_id_get_value (structure,
1114 GST_QUARK (ASYNC)));
1118 * gst_event_new_qos:
1119 * @type: the QoS type
1120 * @proportion: the proportion of the qos message
1121 * @diff: The time difference of the last Clock sync
1122 * @timestamp: The timestamp of the buffer
1124 * Allocate a new qos event with the given values.
1125 * The QOS event is generated in an element that wants an upstream
1126 * element to either reduce or increase its rate because of
1127 * high/low CPU load or other resource usage such as network performance or
1128 * throttling. Typically sinks generate these events for each buffer
1131 * @type indicates the reason for the QoS event. #GST_QOS_TYPE_OVERFLOW is
1132 * used when a buffer arrived in time or when the sink cannot keep up with
1133 * the upstream datarate. #GST_QOS_TYPE_UNDERFLOW is when the sink is not
1134 * receiving buffers fast enough and thus has to drop late buffers.
1135 * #GST_QOS_TYPE_THROTTLE is used when the datarate is artificially limited
1136 * by the application, for example to reduce power consumption.
1138 * @proportion indicates the real-time performance of the streaming in the
1139 * element that generated the QoS event (usually the sink). The value is
1140 * generally computed based on more long term statistics about the streams
1141 * timestamps compared to the clock.
1142 * A value < 1.0 indicates that the upstream element is producing data faster
1143 * than real-time. A value > 1.0 indicates that the upstream element is not
1144 * producing data fast enough. 1.0 is the ideal @proportion value. The
1145 * proportion value can safely be used to lower or increase the quality of
1148 * @diff is the difference against the clock in running time of the last
1149 * buffer that caused the element to generate the QOS event. A negative value
1150 * means that the buffer with @timestamp arrived in time. A positive value
1151 * indicates how late the buffer with @timestamp was. When throttling is
1152 * enabled, @diff will be set to the requested throttling interval.
1154 * @timestamp is the timestamp of the last buffer that cause the element
1155 * to generate the QOS event. It is expressed in running time and thus an ever
1158 * The upstream element can use the @diff and @timestamp values to decide
1159 * whether to process more buffers. For possitive @diff, all buffers with
1160 * timestamp <= @timestamp + @diff will certainly arrive late in the sink
1161 * as well. A (negative) @diff value so that @timestamp + @diff would yield a
1162 * result smaller than 0 is not allowed.
1164 * The application can use general event probes to intercept the QoS
1165 * event and implement custom application specific QoS handling.
1167 * Returns: (transfer full): a new QOS event.
1170 gst_event_new_qos (GstQOSType type, gdouble proportion,
1171 GstClockTimeDiff diff, GstClockTime timestamp)
1174 GstStructure *structure;
1176 /* diff must be positive or timestamp + diff must be positive */
1177 g_return_val_if_fail (diff >= 0 || -diff <= timestamp, NULL);
1179 GST_CAT_LOG (GST_CAT_EVENT,
1180 "creating qos type %d, proportion %lf, diff %" G_GINT64_FORMAT
1181 ", timestamp %" GST_TIME_FORMAT, type, proportion,
1182 diff, GST_TIME_ARGS (timestamp));
1184 structure = gst_structure_new_id (GST_QUARK (EVENT_QOS),
1185 GST_QUARK (TYPE), GST_TYPE_QOS_TYPE, type,
1186 GST_QUARK (PROPORTION), G_TYPE_DOUBLE, proportion,
1187 GST_QUARK (DIFF), G_TYPE_INT64, diff,
1188 GST_QUARK (TIMESTAMP), G_TYPE_UINT64, timestamp, NULL);
1189 event = gst_event_new_custom (GST_EVENT_QOS, structure);
1195 * gst_event_parse_qos:
1196 * @event: The event to query
1197 * @type: (out): A pointer to store the QoS type in
1198 * @proportion: (out): A pointer to store the proportion in
1199 * @diff: (out): A pointer to store the diff in
1200 * @timestamp: (out): A pointer to store the timestamp in
1202 * Get the type, proportion, diff and timestamp in the qos event. See
1203 * gst_event_new_qos() for more information about the different QoS values.
1206 gst_event_parse_qos (GstEvent * event, GstQOSType * type,
1207 gdouble * proportion, GstClockTimeDiff * diff, GstClockTime * timestamp)
1209 const GstStructure *structure;
1211 g_return_if_fail (GST_IS_EVENT (event));
1212 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_QOS);
1214 structure = GST_EVENT_STRUCTURE (event);
1216 *type = (GstQOSType)
1217 g_value_get_enum (gst_structure_id_get_value (structure,
1221 g_value_get_double (gst_structure_id_get_value (structure,
1222 GST_QUARK (PROPORTION)));
1225 g_value_get_int64 (gst_structure_id_get_value (structure,
1229 g_value_get_uint64 (gst_structure_id_get_value (structure,
1230 GST_QUARK (TIMESTAMP)));
1234 * gst_event_new_seek:
1235 * @rate: The new playback rate
1236 * @format: The format of the seek values
1237 * @flags: The optional seek flags
1238 * @start_type: The type and flags for the new start position
1239 * @start: The value of the new start position
1240 * @stop_type: The type and flags for the new stop position
1241 * @stop: The value of the new stop position
1243 * Allocate a new seek event with the given parameters.
1245 * The seek event configures playback of the pipeline between @start to @stop
1246 * at the speed given in @rate, also called a playback segment.
1247 * The @start and @stop values are expressed in @format.
1249 * A @rate of 1.0 means normal playback rate, 2.0 means double speed.
1250 * Negatives values means backwards playback. A value of 0.0 for the
1251 * rate is not allowed and should be accomplished instead by PAUSING the
1254 * A pipeline has a default playback segment configured with a start
1255 * position of 0, a stop position of -1 and a rate of 1.0. The currently
1256 * configured playback segment can be queried with #GST_QUERY_SEGMENT.
1258 * @start_type and @stop_type specify how to adjust the currently configured
1259 * start and stop fields in playback segment. Adjustments can be made relative
1260 * or absolute to the last configured values. A type of #GST_SEEK_TYPE_NONE
1261 * means that the position should not be updated.
1263 * When the rate is positive and @start has been updated, playback will start
1264 * from the newly configured start position.
1266 * For negative rates, playback will start from the newly configured stop
1267 * position (if any). If the stop position is updated, it must be different from
1268 * -1 (#GST_CLOCK_TIME_NONE) for negative rates.
1270 * It is not possible to seek relative to the current playback position, to do
1271 * this, PAUSE the pipeline, query the current playback position with
1272 * #GST_QUERY_POSITION and update the playback segment current position with a
1273 * #GST_SEEK_TYPE_SET to the desired position.
1275 * Returns: (transfer full): a new seek event.
1278 gst_event_new_seek (gdouble rate, GstFormat format, GstSeekFlags flags,
1279 GstSeekType start_type, gint64 start, GstSeekType stop_type, gint64 stop)
1282 GstStructure *structure;
1284 g_return_val_if_fail (rate != 0.0, NULL);
1286 if (format == GST_FORMAT_TIME) {
1287 GST_CAT_INFO (GST_CAT_EVENT,
1288 "creating seek rate %lf, format TIME, flags %d, "
1289 "start_type %d, start %" GST_TIME_FORMAT ", "
1290 "stop_type %d, stop %" GST_TIME_FORMAT,
1291 rate, flags, start_type, GST_TIME_ARGS (start),
1292 stop_type, GST_TIME_ARGS (stop));
1294 GST_CAT_INFO (GST_CAT_EVENT,
1295 "creating seek rate %lf, format %s, flags %d, "
1296 "start_type %d, start %" G_GINT64_FORMAT ", "
1297 "stop_type %d, stop %" G_GINT64_FORMAT,
1298 rate, gst_format_get_name (format), flags, start_type, start, stop_type,
1302 structure = gst_structure_new_id (GST_QUARK (EVENT_SEEK),
1303 GST_QUARK (RATE), G_TYPE_DOUBLE, rate,
1304 GST_QUARK (FORMAT), GST_TYPE_FORMAT, format,
1305 GST_QUARK (FLAGS), GST_TYPE_SEEK_FLAGS, flags,
1306 GST_QUARK (CUR_TYPE), GST_TYPE_SEEK_TYPE, start_type,
1307 GST_QUARK (CUR), G_TYPE_INT64, start,
1308 GST_QUARK (STOP_TYPE), GST_TYPE_SEEK_TYPE, stop_type,
1309 GST_QUARK (STOP), G_TYPE_INT64, stop, NULL);
1310 event = gst_event_new_custom (GST_EVENT_SEEK, structure);
1316 * gst_event_parse_seek:
1317 * @event: a seek event
1318 * @rate: (out): result location for the rate
1319 * @format: (out): result location for the stream format
1320 * @flags: (out): result location for the #GstSeekFlags
1321 * @start_type: (out): result location for the #GstSeekType of the start position
1322 * @start: (out): result location for the start postion expressed in @format
1323 * @stop_type: (out): result location for the #GstSeekType of the stop position
1324 * @stop: (out): result location for the stop postion expressed in @format
1326 * Parses a seek @event and stores the results in the given result locations.
1329 gst_event_parse_seek (GstEvent * event, gdouble * rate,
1330 GstFormat * format, GstSeekFlags * flags, GstSeekType * start_type,
1331 gint64 * start, GstSeekType * stop_type, gint64 * stop)
1333 const GstStructure *structure;
1335 g_return_if_fail (GST_IS_EVENT (event));
1336 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_SEEK);
1338 structure = GST_EVENT_STRUCTURE (event);
1341 g_value_get_double (gst_structure_id_get_value (structure,
1344 *format = (GstFormat)
1345 g_value_get_enum (gst_structure_id_get_value (structure,
1346 GST_QUARK (FORMAT)));
1348 *flags = (GstSeekFlags)
1349 g_value_get_flags (gst_structure_id_get_value (structure,
1350 GST_QUARK (FLAGS)));
1352 *start_type = (GstSeekType)
1353 g_value_get_enum (gst_structure_id_get_value (structure,
1354 GST_QUARK (CUR_TYPE)));
1357 g_value_get_int64 (gst_structure_id_get_value (structure,
1360 *stop_type = (GstSeekType)
1361 g_value_get_enum (gst_structure_id_get_value (structure,
1362 GST_QUARK (STOP_TYPE)));
1365 g_value_get_int64 (gst_structure_id_get_value (structure,
1370 * gst_event_new_navigation:
1371 * @structure: (transfer full): description of the event. The event will take
1372 * ownership of the structure.
1374 * Create a new navigation event from the given description.
1376 * Returns: (transfer full): a new #GstEvent
1379 gst_event_new_navigation (GstStructure * structure)
1381 g_return_val_if_fail (structure != NULL, NULL);
1383 return gst_event_new_custom (GST_EVENT_NAVIGATION, structure);
1387 * gst_event_new_latency:
1388 * @latency: the new latency value
1390 * Create a new latency event. The event is sent upstream from the sinks and
1391 * notifies elements that they should add an additional @latency to the
1392 * running time before synchronising against the clock.
1394 * The latency is mostly used in live sinks and is always expressed in
1397 * Returns: (transfer full): a new #GstEvent
1402 gst_event_new_latency (GstClockTime latency)
1405 GstStructure *structure;
1407 GST_CAT_INFO (GST_CAT_EVENT,
1408 "creating latency event %" GST_TIME_FORMAT, GST_TIME_ARGS (latency));
1410 structure = gst_structure_new_id (GST_QUARK (EVENT_LATENCY),
1411 GST_QUARK (LATENCY), G_TYPE_UINT64, latency, NULL);
1412 event = gst_event_new_custom (GST_EVENT_LATENCY, structure);
1418 * gst_event_parse_latency:
1419 * @event: The event to query
1420 * @latency: (out): A pointer to store the latency in.
1422 * Get the latency in the latency event.
1427 gst_event_parse_latency (GstEvent * event, GstClockTime * latency)
1429 g_return_if_fail (GST_IS_EVENT (event));
1430 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_LATENCY);
1434 g_value_get_uint64 (gst_structure_id_get_value (GST_EVENT_STRUCTURE
1435 (event), GST_QUARK (LATENCY)));
1439 * gst_event_new_step:
1440 * @format: the format of @amount
1441 * @amount: the amount of data to step
1442 * @rate: the step rate
1443 * @flush: flushing steps
1444 * @intermediate: intermediate steps
1446 * Create a new step event. The purpose of the step event is to instruct a sink
1447 * to skip @amount (expressed in @format) of media. It can be used to implement
1448 * stepping through the video frame by frame or for doing fast trick modes.
1450 * A rate of <= 0.0 is not allowed. Pause the pipeline, for the effect of rate
1451 * = 0.0 or first reverse the direction of playback using a seek event to get
1452 * the same effect as rate < 0.0.
1454 * The @flush flag will clear any pending data in the pipeline before starting
1455 * the step operation.
1457 * The @intermediate flag instructs the pipeline that this step operation is
1458 * part of a larger step operation.
1460 * Returns: (transfer full): a new #GstEvent
1465 gst_event_new_step (GstFormat format, guint64 amount, gdouble rate,
1466 gboolean flush, gboolean intermediate)
1469 GstStructure *structure;
1471 g_return_val_if_fail (rate > 0.0, NULL);
1473 GST_CAT_INFO (GST_CAT_EVENT, "creating step event");
1475 structure = gst_structure_new_id (GST_QUARK (EVENT_STEP),
1476 GST_QUARK (FORMAT), GST_TYPE_FORMAT, format,
1477 GST_QUARK (AMOUNT), G_TYPE_UINT64, amount,
1478 GST_QUARK (RATE), G_TYPE_DOUBLE, rate,
1479 GST_QUARK (FLUSH), G_TYPE_BOOLEAN, flush,
1480 GST_QUARK (INTERMEDIATE), G_TYPE_BOOLEAN, intermediate, NULL);
1481 event = gst_event_new_custom (GST_EVENT_STEP, structure);
1487 * gst_event_parse_step:
1488 * @event: The event to query
1489 * @format: (out) (allow-none): a pointer to store the format in
1490 * @amount: (out) (allow-none): a pointer to store the amount in
1491 * @rate: (out) (allow-none): a pointer to store the rate in
1492 * @flush: (out) (allow-none): a pointer to store the flush boolean in
1493 * @intermediate: (out) (allow-none): a pointer to store the intermediate
1496 * Parse the step event.
1501 gst_event_parse_step (GstEvent * event, GstFormat * format, guint64 * amount,
1502 gdouble * rate, gboolean * flush, gboolean * intermediate)
1504 const GstStructure *structure;
1506 g_return_if_fail (GST_IS_EVENT (event));
1507 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STEP);
1509 structure = GST_EVENT_STRUCTURE (event);
1512 (GstFormat) g_value_get_enum (gst_structure_id_get_value (structure,
1513 GST_QUARK (FORMAT)));
1515 *amount = g_value_get_uint64 (gst_structure_id_get_value (structure,
1516 GST_QUARK (AMOUNT)));
1518 *rate = g_value_get_double (gst_structure_id_get_value (structure,
1521 *flush = g_value_get_boolean (gst_structure_id_get_value (structure,
1522 GST_QUARK (FLUSH)));
1524 *intermediate = g_value_get_boolean (gst_structure_id_get_value (structure,
1525 GST_QUARK (INTERMEDIATE)));
1529 * gst_event_new_reconfigure:
1531 * Create a new reconfigure event. The purpose of the reconfingure event is
1532 * to travel upstream and make elements renegotiate their caps or reconfigure
1533 * their buffer pools. This is useful when changing properties on elements
1534 * or changing the topology of the pipeline.
1536 * Returns: (transfer full): a new #GstEvent
1541 gst_event_new_reconfigure (void)
1545 GST_CAT_INFO (GST_CAT_EVENT, "creating reconfigure event");
1547 event = gst_event_new_custom (GST_EVENT_RECONFIGURE, NULL);
1553 * gst_event_new_sink_message:
1554 * @msg: (transfer none): the #GstMessage to be posted
1556 * Create a new sink-message event. The purpose of the sink-message event is
1557 * to instruct a sink to post the message contained in the event synchronized
1560 * Returns: (transfer full): a new #GstEvent
1564 /* FIXME 0.11: take ownership of msg for consistency? */
1566 gst_event_new_sink_message (GstMessage * msg)
1569 GstStructure *structure;
1571 g_return_val_if_fail (msg != NULL, NULL);
1573 GST_CAT_INFO (GST_CAT_EVENT, "creating sink-message event");
1575 structure = gst_structure_new_id (GST_QUARK (EVENT_SINK_MESSAGE),
1576 GST_QUARK (MESSAGE), GST_TYPE_MESSAGE, msg, NULL);
1577 event = gst_event_new_custom (GST_EVENT_SINK_MESSAGE, structure);
1583 * gst_event_parse_sink_message:
1584 * @event: The event to query
1585 * @msg: (out) (transfer full): a pointer to store the #GstMessage in.
1587 * Parse the sink-message event. Unref @msg after usage.
1592 gst_event_parse_sink_message (GstEvent * event, GstMessage ** msg)
1594 const GstStructure *structure;
1596 g_return_if_fail (GST_IS_EVENT (event));
1597 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_SINK_MESSAGE);
1599 structure = GST_EVENT_STRUCTURE (event);
1602 GST_MESSAGE (g_value_dup_boxed (gst_structure_id_get_value
1603 (structure, GST_QUARK (MESSAGE))));
1607 * gst_event_new_stream_start
1609 * Create a new STREAM_START event. The stream start event can only
1610 * travel downstream synchronized with the buffer flow. It is expected
1611 * to be the first event that is sent for a new stream.
1613 * Source elements, demuxers and other elements that create new streams
1614 * are supposed to send this event as the first event of a new stream. It
1615 * should not be send after a flushing seek or in similar situations
1616 * and is used to mark the beginning of a new logical stream. Elements
1617 * combining multiple streams must ensure that this event is only forwarded
1618 * downstream once and not for every single input stream.
1620 * Returns: (transfer full): the new STREAM_START event.
1623 gst_event_new_stream_start (void)
1625 return gst_event_new_custom (GST_EVENT_STREAM_START, NULL);
1629 * gst_event_new_toc:
1630 * @toc: #GstToc structure.
1631 * @updated: whether @toc was updated or not.
1633 * Generate a TOC event from the given @toc. The purpose of the TOC event is to
1634 * inform elements that some kind of the TOC was found.
1636 * Returns: a new #GstEvent.
1641 gst_event_new_toc (GstToc * toc, gboolean updated)
1643 GstStructure *toc_struct;
1645 g_return_val_if_fail (toc != NULL, NULL);
1647 GST_CAT_INFO (GST_CAT_EVENT, "creating toc event");
1649 toc_struct = __gst_toc_to_structure (toc);
1651 if (G_LIKELY (toc_struct != NULL)) {
1652 __gst_toc_structure_set_updated (toc_struct, updated);
1653 return gst_event_new_custom (GST_EVENT_TOC, toc_struct);
1659 * gst_event_parse_toc:
1660 * @event: a TOC event.
1661 * @toc: (out): pointer to #GstToc structure.
1662 * @updated: (out): pointer to store TOC updated flag.
1664 * Parse a TOC @event and store the results in the given @toc and @updated locations.
1669 gst_event_parse_toc (GstEvent * event, GstToc ** toc, gboolean * updated)
1671 const GstStructure *structure;
1673 g_return_if_fail (event != NULL);
1674 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_TOC);
1675 g_return_if_fail (toc != NULL);
1677 structure = gst_event_get_structure (event);
1678 *toc = __gst_toc_from_structure (structure);
1680 if (updated != NULL)
1681 *updated = __gst_toc_structure_get_updated (structure);
1685 * gst_event_new_toc_select:
1686 * @uid: UID in the TOC to start playback from.
1688 * Generate a TOC select event with the given @uid. The purpose of the
1689 * TOC select event is to start playback based on the TOC's entry with the
1692 * Returns: a new #GstEvent.
1697 gst_event_new_toc_select (const gchar * uid)
1699 GstStructure *structure;
1701 g_return_val_if_fail (uid != NULL, NULL);
1703 GST_CAT_INFO (GST_CAT_EVENT, "creating toc select event for UID: %s", uid);
1705 structure = gst_structure_new_id (GST_QUARK (EVENT_TOC_SELECT),
1706 GST_QUARK (UID), G_TYPE_STRING, uid, NULL);
1708 return gst_event_new_custom (GST_EVENT_TOC_SELECT, structure);
1712 * gst_event_parse_toc_select:
1713 * @event: a TOC select event.
1714 * @uid: (out): storage for the selection UID.
1716 * Parse a TOC select @event and store the results in the given @uid location.
1721 gst_event_parse_toc_select (GstEvent * event, gchar ** uid)
1723 const GstStructure *structure;
1726 g_return_if_fail (event != NULL);
1727 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_TOC_SELECT);
1729 structure = gst_event_get_structure (event);
1730 val = gst_structure_id_get_value (structure, GST_QUARK (UID));
1733 *uid = g_strdup (g_value_get_string (val));