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 2006-09-6 (0.10.10)
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_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_CUSTOM_UPSTREAM, "custom-upstream", 0},
128 {GST_EVENT_CUSTOM_DOWNSTREAM, "custom-downstream", 0},
129 {GST_EVENT_CUSTOM_DOWNSTREAM_OOB, "custom-downstream-oob", 0},
130 {GST_EVENT_CUSTOM_DOWNSTREAM_STICKY, "custom-downstream-sticky", 0},
131 {GST_EVENT_CUSTOM_BOTH, "custom-both", 0},
132 {GST_EVENT_CUSTOM_BOTH_OOB, "custom-both-oob", 0},
137 GST_DEFINE_MINI_OBJECT_TYPE (GstEvent, gst_event);
140 _priv_gst_event_initialize (void)
144 _gst_event_type = gst_event_get_type ();
146 g_type_class_ref (gst_seek_flags_get_type ());
147 g_type_class_ref (gst_seek_type_get_type ());
149 for (i = 0; event_quarks[i].name; i++) {
150 event_quarks[i].quark = g_quark_from_static_string (event_quarks[i].name);
155 * gst_event_type_get_name:
156 * @type: the event type
158 * Get a printable name for the given event type. Do not modify or free.
160 * Returns: a reference to the static name of the event.
163 gst_event_type_get_name (GstEventType type)
167 for (i = 0; event_quarks[i].name; i++) {
168 if (type == event_quarks[i].type)
169 return event_quarks[i].name;
175 * gst_event_type_to_quark:
176 * @type: the event type
178 * Get the unique quark for the given event type.
180 * Returns: the quark associated with the event type
183 gst_event_type_to_quark (GstEventType type)
187 for (i = 0; event_quarks[i].name; i++) {
188 if (type == event_quarks[i].type)
189 return event_quarks[i].quark;
195 * gst_event_type_get_flags:
196 * @type: a #GstEventType
198 * Gets the #GstEventTypeFlags associated with @type.
200 * Returns: a #GstEventTypeFlags.
203 gst_event_type_get_flags (GstEventType type)
205 GstEventTypeFlags ret;
207 ret = type & ((1 << GST_EVENT_NUM_SHIFT) - 1);
213 _gst_event_free (GstEvent * event)
217 g_return_if_fail (event != NULL);
218 g_return_if_fail (GST_IS_EVENT (event));
220 GST_CAT_LOG (GST_CAT_EVENT, "freeing event %p type %s", event,
221 GST_EVENT_TYPE_NAME (event));
223 s = GST_EVENT_STRUCTURE (event);
226 gst_structure_set_parent_refcount (s, NULL);
227 gst_structure_free (s);
230 g_slice_free1 (GST_MINI_OBJECT_SIZE (event), event);
233 static void gst_event_init (GstEventImpl * event, gsize size,
237 _gst_event_copy (GstEvent * event)
242 copy = g_slice_new0 (GstEventImpl);
244 gst_event_init (copy, sizeof (GstEventImpl), GST_EVENT_TYPE (event));
246 GST_EVENT_TIMESTAMP (copy) = GST_EVENT_TIMESTAMP (event);
247 GST_EVENT_SEQNUM (copy) = GST_EVENT_SEQNUM (event);
249 s = GST_EVENT_STRUCTURE (event);
251 GST_EVENT_STRUCTURE (copy) = gst_structure_copy (s);
252 gst_structure_set_parent_refcount (GST_EVENT_STRUCTURE (copy),
253 ©->event.mini_object.refcount);
255 return GST_EVENT_CAST (copy);
259 gst_event_init (GstEventImpl * event, gsize size, GstEventType type)
261 gst_mini_object_init (GST_MINI_OBJECT_CAST (event), _gst_event_type, size);
263 event->event.mini_object.copy = (GstMiniObjectCopyFunction) _gst_event_copy;
264 event->event.mini_object.free = (GstMiniObjectFreeFunction) _gst_event_free;
266 GST_EVENT_TYPE (event) = type;
267 GST_EVENT_TIMESTAMP (event) = GST_CLOCK_TIME_NONE;
268 GST_EVENT_SEQNUM (event) = gst_util_seqnum_next ();
272 gst_event_new (GstEventType type)
276 event = g_slice_new0 (GstEventImpl);
278 GST_CAT_DEBUG (GST_CAT_EVENT, "creating new event %p %s %d", event,
279 gst_event_type_get_name (type), type);
281 gst_event_init (event, sizeof (GstEventImpl), type);
283 return GST_EVENT_CAST (event);
287 * gst_event_new_custom:
288 * @type: The type of the new event
289 * @structure: (transfer full): the structure for the event. The event will
290 * take ownership of the structure.
292 * Create a new custom-typed event. This can be used for anything not
293 * handled by other event-specific functions to pass an event to another
296 * Make sure to allocate an event type with the #GST_EVENT_MAKE_TYPE macro,
297 * assigning a free number and filling in the correct direction and
298 * serialization flags.
300 * New custom events can also be created by subclassing the event type if
303 * Returns: (transfer full): the new custom event.
306 gst_event_new_custom (GstEventType type, GstStructure * structure)
310 /* structure must not have a parent */
311 event = gst_event_new (type);
313 if (!gst_structure_set_parent_refcount (structure,
314 &event->mini_object.refcount))
317 GST_EVENT_STRUCTURE (event) = structure;
324 gst_event_unref (event);
325 g_warning ("structure is already owned by another object");
331 * gst_event_get_structure:
332 * @event: The #GstEvent.
334 * Access the structure of the event.
336 * Returns: The structure of the event. The structure is still
337 * owned by the event, which means that you should not free it and
338 * that the pointer becomes invalid when you free the event.
343 gst_event_get_structure (GstEvent * event)
345 g_return_val_if_fail (GST_IS_EVENT (event), NULL);
347 return GST_EVENT_STRUCTURE (event);
351 * gst_event_writable_structure:
352 * @event: The #GstEvent.
354 * Get a writable version of the structure.
356 * Returns: The structure of the event. The structure is still
357 * owned by the event, which means that you should not free it and
358 * that the pointer becomes invalid when you free the event.
359 * This function checks if @event is writable and will never return NULL.
364 gst_event_writable_structure (GstEvent * event)
366 GstStructure *structure;
368 g_return_val_if_fail (GST_IS_EVENT (event), NULL);
369 g_return_val_if_fail (gst_event_is_writable (event), NULL);
371 structure = GST_EVENT_STRUCTURE (event);
373 if (structure == NULL) {
375 gst_structure_new_id_empty (gst_event_type_to_quark (GST_EVENT_TYPE
377 gst_structure_set_parent_refcount (structure, &event->mini_object.refcount);
378 GST_EVENT_STRUCTURE (event) = structure;
384 * gst_event_has_name:
385 * @event: The #GstEvent.
386 * @name: name to check
388 * Checks if @event has the given @name. This function is usually used to
389 * check the name of a custom event.
391 * Returns: %TRUE if @name matches the name of the event structure.
396 gst_event_has_name (GstEvent * event, const gchar * name)
398 g_return_val_if_fail (GST_IS_EVENT (event), FALSE);
400 if (GST_EVENT_STRUCTURE (event) == NULL)
403 return gst_structure_has_name (GST_EVENT_STRUCTURE (event), name);
407 * gst_event_get_seqnum:
408 * @event: A #GstEvent.
410 * Retrieve the sequence number of a event.
412 * Events have ever-incrementing sequence numbers, which may also be set
413 * explicitly via gst_event_set_seqnum(). Sequence numbers are typically used to
414 * indicate that a event corresponds to some other set of events or messages,
415 * for example an EOS event corresponding to a SEEK event. It is considered good
416 * practice to make this correspondence when possible, though it is not
419 * Note that events and messages share the same sequence number incrementor;
420 * two events or messages will never have the same sequence number unless
421 * that correspondence was made explicitly.
423 * Returns: The event's sequence number.
430 gst_event_get_seqnum (GstEvent * event)
432 g_return_val_if_fail (GST_IS_EVENT (event), -1);
434 return GST_EVENT_SEQNUM (event);
438 * gst_event_set_seqnum:
439 * @event: A #GstEvent.
440 * @seqnum: A sequence number.
442 * Set the sequence number of a event.
444 * This function might be called by the creator of a event to indicate that the
445 * event relates to other events or messages. See gst_event_get_seqnum() for
453 gst_event_set_seqnum (GstEvent * event, guint32 seqnum)
455 g_return_if_fail (GST_IS_EVENT (event));
457 GST_EVENT_SEQNUM (event) = seqnum;
460 /* FIXME 0.11: It would be nice to have flush events
461 * that don't reset the running time in the sinks
465 * gst_event_new_flush_start:
467 * Allocate a new flush start event. The flush start event can be sent
468 * upstream and downstream and travels out-of-bounds with the dataflow.
470 * It marks pads as being flushing and will make them return
471 * #GST_FLOW_WRONG_STATE when used for data flow with gst_pad_push(),
472 * gst_pad_chain(), gst_pad_alloc_buffer(), gst_pad_get_range() and
473 * gst_pad_pull_range(). Any event (except a #GST_EVENT_FLUSH_STOP) received
474 * on a flushing pad will return %FALSE immediately.
476 * Elements should unlock any blocking functions and exit their streaming
477 * functions as fast as possible when this event is received.
479 * This event is typically generated after a seek to flush out all queued data
480 * in the pipeline so that the new media is played as soon as possible.
482 * Returns: (transfer full): a new flush start event.
485 gst_event_new_flush_start (void)
487 return gst_event_new (GST_EVENT_FLUSH_START);
491 * gst_event_new_flush_stop:
492 * @reset_time: if time should be reset
494 * Allocate a new flush stop event. The flush stop event can be sent
495 * upstream and downstream and travels serialized with the dataflow.
496 * It is typically sent after sending a FLUSH_START event to make the
497 * pads accept data again.
499 * Elements can process this event synchronized with the dataflow since
500 * the preceeding FLUSH_START event stopped the dataflow.
502 * This event is typically generated to complete a seek and to resume
505 * Returns: (transfer full): a new flush stop event.
508 gst_event_new_flush_stop (gboolean reset_time)
512 GST_CAT_INFO (GST_CAT_EVENT, "creating flush stop %d", reset_time);
514 event = gst_event_new_custom (GST_EVENT_FLUSH_STOP,
515 gst_structure_new_id (GST_QUARK (EVENT_FLUSH_STOP),
516 GST_QUARK (RESET_TIME), G_TYPE_BOOLEAN, reset_time, NULL));
522 * gst_event_parse_flush_stop:
523 * @event: The event to parse
524 * @reset_time: (out): if time should be reset
526 * Parse the FLUSH_STOP event and retrieve the @reset_time member.
529 gst_event_parse_flush_stop (GstEvent * event, gboolean * reset_time)
531 GstStructure *structure;
533 g_return_if_fail (GST_IS_EVENT (event));
534 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_FLUSH_STOP);
536 structure = GST_EVENT_STRUCTURE (event);
537 if (G_LIKELY (reset_time))
539 g_value_get_boolean (gst_structure_id_get_value (structure,
540 GST_QUARK (RESET_TIME)));
546 * Create a new EOS event. The eos event can only travel downstream
547 * synchronized with the buffer flow. Elements that receive the EOS
548 * event on a pad can return #GST_FLOW_UNEXPECTED as a #GstFlowReturn
549 * when data after the EOS event arrives.
551 * The EOS event will travel down to the sink elements in the pipeline
552 * which will then post the #GST_MESSAGE_EOS on the bus after they have
553 * finished playing any buffered data.
555 * When all sinks have posted an EOS message, an EOS message is
556 * forwarded to the application.
558 * The EOS event itself will not cause any state transitions of the pipeline.
560 * Returns: (transfer full): the new EOS event.
563 gst_event_new_eos (void)
565 return gst_event_new (GST_EVENT_EOS);
570 * @timestamp: the start time (pts) of a gap
571 * @duration: the duration of the gap, or %GST_CLOCK_TIME_NONE
573 * Create a new GAP event. A gap event can be thought of as conceptually
574 * equivalent to a buffer to signal that there is no data for a certain
575 * amount of time. This is useful to signal a gap to downstream elements
576 * which may wait for data, such as muxers or mixers or overlays, especially
577 * for sparse streams such as subtitle streams.
579 * Returns: (transfer full): the new GAP event.
582 gst_event_new_gap (GstClockTime timestamp, GstClockTime duration)
586 g_return_val_if_fail (GST_CLOCK_TIME_IS_VALID (timestamp), NULL);
588 GST_CAT_TRACE (GST_CAT_EVENT, "creating gap %" GST_TIME_FORMAT " - "
589 "%" GST_TIME_FORMAT " (duration: %" GST_TIME_FORMAT ")",
590 GST_TIME_ARGS (timestamp),
591 GST_TIME_ARGS (GST_CLOCK_TIME_IS_VALID (duration) ? (timestamp +
592 duration) : GST_CLOCK_TIME_NONE), GST_TIME_ARGS (duration));
594 event = gst_event_new_custom (GST_EVENT_GAP,
595 gst_structure_new_id (GST_QUARK (EVENT_GAP),
596 GST_QUARK (TIMESTAMP), GST_TYPE_CLOCK_TIME, timestamp,
597 GST_QUARK (DURATION), GST_TYPE_CLOCK_TIME, duration, NULL));
603 * gst_event_parse_gap:
604 * @timestamp: (out): location where to store the start time (pts) of the gap
605 * @duration: (out) (allow-none): location where to store the duration of
608 * Extract timestamp and duration from a new GAP event.
611 gst_event_parse_gap (GstEvent * event, GstClockTime * timestamp,
612 GstClockTime * duration)
614 GstStructure *structure;
616 g_return_if_fail (GST_IS_EVENT (event));
617 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_GAP);
619 structure = GST_EVENT_STRUCTURE (event);
620 gst_structure_id_get (structure,
621 GST_QUARK (TIMESTAMP), GST_TYPE_CLOCK_TIME, timestamp,
622 GST_QUARK (DURATION), GST_TYPE_CLOCK_TIME, duration, NULL);
626 * gst_event_new_caps:
627 * @caps: (transfer none): a #GstCaps
629 * Create a new CAPS event for @caps. The caps event can only travel downstream
630 * synchronized with the buffer flow and contains the format of the buffers
631 * that will follow after the event.
633 * Returns: (transfer full): the new CAPS event.
636 gst_event_new_caps (GstCaps * caps)
640 g_return_val_if_fail (caps != NULL, NULL);
641 g_return_val_if_fail (gst_caps_is_fixed (caps), NULL);
643 GST_CAT_INFO (GST_CAT_EVENT, "creating caps event %" GST_PTR_FORMAT, caps);
645 event = gst_event_new_custom (GST_EVENT_CAPS,
646 gst_structure_new_id (GST_QUARK (EVENT_CAPS),
647 GST_QUARK (CAPS), GST_TYPE_CAPS, caps, NULL));
653 * gst_event_parse_caps:
654 * @event: The event to parse
655 * @caps: (out): A pointer to the caps
657 * Get the caps from @event. The caps remains valid as long as @event remains
661 gst_event_parse_caps (GstEvent * event, GstCaps ** caps)
663 GstStructure *structure;
665 g_return_if_fail (GST_IS_EVENT (event));
666 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_CAPS);
668 structure = GST_EVENT_STRUCTURE (event);
671 g_value_get_boxed (gst_structure_id_get_value (structure,
676 * gst_event_new_stream_config:
677 * @flags: the stream config flags
679 * Create a new STREAM CONFIG event. The stream config event travels
680 * downstream synchronized with the buffer flow and contains stream
681 * configuration information for the stream, such as stream-headers
682 * or codec-data. It is optional and should be sent after the CAPS
685 * Returns: (transfer full): the new STREAM CONFIG event.
688 gst_event_new_stream_config (GstStreamConfigFlags flags)
692 GST_CAT_INFO (GST_CAT_EVENT, "creating stream info event, flags=0x%x", flags);
694 event = gst_event_new_custom (GST_EVENT_STREAM_CONFIG,
695 gst_structure_new_id (GST_QUARK (EVENT_STREAM_CONFIG),
696 GST_QUARK (FLAGS), GST_TYPE_STREAM_CONFIG_FLAGS, flags, NULL));
702 * gst_event_parse_stream_config:
703 * @event: The event to parse
704 * @flags: (out): a pointer to a variable to store the stream config flags
706 * Get the stream config flags from @event.
709 gst_event_parse_stream_config (GstEvent * event, GstStreamConfigFlags * flags)
711 GstStructure *structure;
713 g_return_if_fail (GST_IS_EVENT (event));
714 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STREAM_CONFIG);
716 structure = GST_EVENT_STRUCTURE (event);
717 if (G_LIKELY (flags != NULL)) {
719 g_value_get_enum (gst_structure_id_get_value (structure,
725 * gst_event_set_stream_config_codec_data:
726 * @event: a stream config event
727 * @buf: a #GstBuffer with codec data
729 * Set codec data on the stream info event to signal out of bound setup data
730 * to downstream elements. Unlike stream headers, codec data contains data
731 * that is required to interpret the data stream, but is not valid as-is
732 * inside the data stream and thus can't just be prepended to or inserted
733 * into the data stream.
736 gst_event_set_stream_config_codec_data (GstEvent * event, GstBuffer * buf)
740 g_return_if_fail (GST_IS_EVENT (event));
741 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STREAM_CONFIG);
742 g_return_if_fail (GST_IS_BUFFER (buf) && gst_buffer_get_size (buf) > 0);
744 s = GST_EVENT_STRUCTURE (event);
745 gst_structure_id_set (s, GST_QUARK (CODEC_DATA), GST_TYPE_BUFFER, buf, NULL);
749 * gst_event_set_stream_config_codec_data:
750 * @event: a stream config event
751 * @buf: (transfer none): location where to store the #GstBuffer with codec data
753 * Extracts the codec data buffer from the stream info event. Will store
754 * %NULL in @buf if the event contains no codec data. The buffer returned
755 * will remain valid as long as @event remains valid. The caller should
756 * acquire a referenceto to @buf if needed.
759 gst_event_parse_stream_config_codec_data (GstEvent * event, GstBuffer ** buf)
764 g_return_if_fail (GST_IS_EVENT (event));
765 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STREAM_CONFIG);
766 g_return_if_fail (buf != NULL);
768 s = GST_EVENT_STRUCTURE (event);
769 val = gst_structure_id_get_value (s, GST_QUARK (CODEC_DATA));
771 *buf = g_value_get_boxed (val);
777 * gst_event_add_stream_config_header:
778 * @event: a stream config event
779 * @buf: a #GstBuffer with stream header data
781 * Adds a stream header to the stream info event to signal stream headers to
782 * to downstream elements such as multifilesink, tcpserversink etc. Stream
783 * headers can be and should usually be prepended to the data stream at any
784 * point in the stream (which requires a streamable format), e.g. to a new
785 * client connecting, or when starting a new file segment. stream header
786 * buffers will all be used together in the order they were added to the
787 * stream config event. Stream headers are sent as buffers at the beginning
788 * of the data flow in addition to the stream config event. Elements that
789 * care about stream headers need to make sure that they don't insert or
790 * interpret these header buffers twice if they interpret them.
793 gst_event_add_stream_config_header (GstEvent * event, GstBuffer * buf)
796 GValue buf_val = { 0, };
799 g_return_if_fail (GST_IS_EVENT (event));
800 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STREAM_CONFIG);
801 g_return_if_fail (GST_IS_BUFFER (buf) && gst_buffer_get_size (buf) > 0);
803 g_value_init (&buf_val, GST_TYPE_BUFFER);
804 g_value_set_boxed (&buf_val, buf);
806 s = GST_EVENT_STRUCTURE (event);
807 val = (GValue *) gst_structure_id_get_value (s, GST_QUARK (STREAM_HEADERS));
809 GValue new_array = { 0, };
811 g_value_init (&new_array, GST_TYPE_ARRAY);
812 gst_value_array_append_value (&new_array, &buf_val);
813 gst_structure_id_take_value (s, GST_QUARK (STREAM_HEADERS), &new_array);
815 gst_value_array_append_value (val, &buf_val);
817 g_value_unset (&buf_val);
821 * gst_event_get_n_stream_config_headers:
822 * @event: a stream config event
824 * Extract the number of stream header buffers.
826 * Returns: the number of stream header buffers attached to the stream info
830 gst_event_get_n_stream_config_headers (GstEvent * event)
836 g_return_val_if_fail (GST_IS_EVENT (event), 0);
837 g_return_val_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STREAM_CONFIG, 0);
839 s = GST_EVENT_STRUCTURE (event);
840 val = gst_structure_id_get_value (s, GST_QUARK (STREAM_HEADERS));
843 num = gst_value_array_get_size (val);
849 * gst_event_parse_nth_stream_config_header:
850 * @event: a stream config event
851 * @index: number of the stream header to retrieve
852 * @buf: location where to store the n-th stream header #GstBuffer
854 * Retrieves the n-th stream header buffer attached to the stream config
855 * event and stores it in @buf. Will store %NULL in @buf if there is no such
859 gst_event_parse_nth_stream_config_header (GstEvent * event, guint index,
862 const GValue *val, *buf_val;
864 GstBuffer *ret = NULL;
866 g_return_if_fail (GST_IS_EVENT (event));
867 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STREAM_CONFIG);
868 g_return_if_fail (buf != NULL);
870 s = GST_EVENT_STRUCTURE (event);
871 val = gst_structure_id_get_value (s, GST_QUARK (STREAM_HEADERS));
874 buf_val = gst_value_array_get_value (val, index);
876 ret = g_value_get_boxed (buf_val);
883 * gst_event_new_segment:
884 * @segment: (transfer none): a #GstSegment
886 * Create a new SEGMENT event for @segment. The segment event can only travel
887 * downstream synchronized with the buffer flow and contains timing information
888 * and playback properties for the buffers that will follow.
890 * The newsegment event marks the range of buffers to be processed. All
891 * data not within the segment range is not to be processed. This can be
892 * used intelligently by plugins to apply more efficient methods of skipping
893 * unneeded data. The valid range is expressed with the @start and @stop
896 * The time value of the segment is used in conjunction with the start
897 * value to convert the buffer timestamps into the stream time. This is
898 * usually done in sinks to report the current stream_time.
899 * @time represents the stream_time of a buffer carrying a timestamp of
900 * @start. @time cannot be -1.
902 * @start cannot be -1, @stop can be -1. If there
903 * is a valid @stop given, it must be greater or equal the @start, including
904 * when the indicated playback @rate is < 0.
906 * The @applied_rate value provides information about any rate adjustment that
907 * has already been made to the timestamps and content on the buffers of the
908 * stream. (@rate * @applied_rate) should always equal the rate that has been
909 * requested for playback. For example, if an element has an input segment
910 * with intended playback @rate of 2.0 and applied_rate of 1.0, it can adjust
911 * incoming timestamps and buffer content by half and output a newsegment event
912 * with @rate of 1.0 and @applied_rate of 2.0
914 * After a newsegment event, the buffer stream time is calculated with:
916 * time + (TIMESTAMP(buf) - start) * ABS (rate * applied_rate)
918 * Returns: (transfer full): the new SEGMENT event.
921 gst_event_new_segment (const GstSegment * segment)
925 g_return_val_if_fail (segment != NULL, NULL);
926 g_return_val_if_fail (segment->rate != 0.0, NULL);
927 g_return_val_if_fail (segment->applied_rate != 0.0, NULL);
928 g_return_val_if_fail (segment->format != GST_FORMAT_UNDEFINED, NULL);
930 GST_CAT_INFO (GST_CAT_EVENT, "creating segment event %" GST_SEGMENT_FORMAT,
933 event = gst_event_new_custom (GST_EVENT_SEGMENT,
934 gst_structure_new_id (GST_QUARK (EVENT_SEGMENT),
935 GST_QUARK (SEGMENT), GST_TYPE_SEGMENT, segment, NULL));
941 * gst_event_parse_segment:
942 * @event: The event to parse
943 * @segment: (out) (transfer none): a pointer to a #GstSegment
945 * Parses a segment @event and stores the result in the given @segment location.
946 * @segment remains valid only until the @event is freed. Don't modify the segment
947 * and make a copy if you want to modify it or store it for later use.
950 gst_event_parse_segment (GstEvent * event, const GstSegment ** segment)
952 GstStructure *structure;
954 g_return_if_fail (GST_IS_EVENT (event));
955 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_SEGMENT);
958 structure = GST_EVENT_STRUCTURE (event);
959 *segment = g_value_get_boxed (gst_structure_id_get_value (structure,
960 GST_QUARK (SEGMENT)));
965 * gst_event_copy_segment:
966 * @event: The event to parse
967 * @segment: a pointer to a #GstSegment
969 * Parses a segment @event and copies the #GstSegment into the location
973 gst_event_copy_segment (GstEvent * event, GstSegment * segment)
975 const GstSegment *src;
977 g_return_if_fail (GST_IS_EVENT (event));
978 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_SEGMENT);
981 gst_event_parse_segment (event, &src);
982 gst_segment_copy_into (src, segment);
988 * @taglist: (transfer full): metadata list. The event will take ownership
991 * Generates a metadata tag event from the given @taglist.
993 * Returns: (transfer full): a new #GstEvent
996 gst_event_new_tag (GstTagList * taglist)
998 g_return_val_if_fail (taglist != NULL, NULL);
1000 return gst_event_new_custom (GST_EVENT_TAG, (GstStructure *) taglist);
1004 * gst_event_parse_tag:
1005 * @event: a tag event
1006 * @taglist: (out) (transfer none): pointer to metadata list
1008 * Parses a tag @event and stores the results in the given @taglist location.
1009 * No reference to the taglist will be returned, it remains valid only until
1010 * the @event is freed. Don't modify or free the taglist, make a copy if you
1011 * want to modify it or store it for later use.
1014 gst_event_parse_tag (GstEvent * event, GstTagList ** taglist)
1016 g_return_if_fail (GST_IS_EVENT (event));
1017 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_TAG);
1020 *taglist = (GstTagList *) GST_EVENT_STRUCTURE (event);
1023 /* buffersize event */
1025 * gst_event_new_buffer_size:
1026 * @format: buffer format
1027 * @minsize: minimum buffer size
1028 * @maxsize: maximum buffer size
1029 * @async: thread behavior
1031 * Create a new buffersize event. The event is sent downstream and notifies
1032 * elements that they should provide a buffer of the specified dimensions.
1034 * When the @async flag is set, a thread boundary is preferred.
1036 * Returns: (transfer full): a new #GstEvent
1039 gst_event_new_buffer_size (GstFormat format, gint64 minsize,
1040 gint64 maxsize, gboolean async)
1043 GstStructure *structure;
1045 GST_CAT_INFO (GST_CAT_EVENT,
1046 "creating buffersize format %s, minsize %" G_GINT64_FORMAT
1047 ", maxsize %" G_GINT64_FORMAT ", async %d", gst_format_get_name (format),
1048 minsize, maxsize, async);
1050 structure = gst_structure_new_id (GST_QUARK (EVENT_BUFFER_SIZE),
1051 GST_QUARK (FORMAT), GST_TYPE_FORMAT, format,
1052 GST_QUARK (MINSIZE), G_TYPE_INT64, minsize,
1053 GST_QUARK (MAXSIZE), G_TYPE_INT64, maxsize,
1054 GST_QUARK (ASYNC), G_TYPE_BOOLEAN, async, NULL);
1055 event = gst_event_new_custom (GST_EVENT_BUFFERSIZE, structure);
1061 * gst_event_parse_buffer_size:
1062 * @event: The event to query
1063 * @format: (out): A pointer to store the format in
1064 * @minsize: (out): A pointer to store the minsize in
1065 * @maxsize: (out): A pointer to store the maxsize in
1066 * @async: (out): A pointer to store the async-flag in
1068 * Get the format, minsize, maxsize and async-flag in the buffersize event.
1071 gst_event_parse_buffer_size (GstEvent * event, GstFormat * format,
1072 gint64 * minsize, gint64 * maxsize, gboolean * async)
1074 const GstStructure *structure;
1076 g_return_if_fail (GST_IS_EVENT (event));
1077 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_BUFFERSIZE);
1079 structure = GST_EVENT_STRUCTURE (event);
1081 *format = (GstFormat)
1082 g_value_get_enum (gst_structure_id_get_value (structure,
1083 GST_QUARK (FORMAT)));
1086 g_value_get_int64 (gst_structure_id_get_value (structure,
1087 GST_QUARK (MINSIZE)));
1090 g_value_get_int64 (gst_structure_id_get_value (structure,
1091 GST_QUARK (MAXSIZE)));
1094 g_value_get_boolean (gst_structure_id_get_value (structure,
1095 GST_QUARK (ASYNC)));
1099 * gst_event_new_qos:
1100 * @type: the QoS type
1101 * @proportion: the proportion of the qos message
1102 * @diff: The time difference of the last Clock sync
1103 * @timestamp: The timestamp of the buffer
1105 * Allocate a new qos event with the given values.
1106 * The QOS event is generated in an element that wants an upstream
1107 * element to either reduce or increase its rate because of
1108 * high/low CPU load or other resource usage such as network performance or
1109 * throttling. Typically sinks generate these events for each buffer
1112 * @type indicates the reason for the QoS event. #GST_QOS_TYPE_OVERFLOW is
1113 * used when a buffer arrived in time or when the sink cannot keep up with
1114 * the upstream datarate. #GST_QOS_TYPE_UNDERFLOW is when the sink is not
1115 * receiving buffers fast enough and thus has to drop late buffers.
1116 * #GST_QOS_TYPE_THROTTLE is used when the datarate is artificially limited
1117 * by the application, for example to reduce power consumption.
1119 * @proportion indicates the real-time performance of the streaming in the
1120 * element that generated the QoS event (usually the sink). The value is
1121 * generally computed based on more long term statistics about the streams
1122 * timestamps compared to the clock.
1123 * A value < 1.0 indicates that the upstream element is producing data faster
1124 * than real-time. A value > 1.0 indicates that the upstream element is not
1125 * producing data fast enough. 1.0 is the ideal @proportion value. The
1126 * proportion value can safely be used to lower or increase the quality of
1129 * @diff is the difference against the clock in running time of the last
1130 * buffer that caused the element to generate the QOS event. A negative value
1131 * means that the buffer with @timestamp arrived in time. A positive value
1132 * indicates how late the buffer with @timestamp was. When throttling is
1133 * enabled, @diff will be set to the requested throttling interval.
1135 * @timestamp is the timestamp of the last buffer that cause the element
1136 * to generate the QOS event. It is expressed in running time and thus an ever
1139 * The upstream element can use the @diff and @timestamp values to decide
1140 * whether to process more buffers. For possitive @diff, all buffers with
1141 * timestamp <= @timestamp + @diff will certainly arrive late in the sink
1142 * as well. A (negative) @diff value so that @timestamp + @diff would yield a
1143 * result smaller than 0 is not allowed.
1145 * The application can use general event probes to intercept the QoS
1146 * event and implement custom application specific QoS handling.
1148 * Returns: (transfer full): a new QOS event.
1151 gst_event_new_qos (GstQOSType type, gdouble proportion,
1152 GstClockTimeDiff diff, GstClockTime timestamp)
1155 GstStructure *structure;
1157 /* diff must be positive or timestamp + diff must be positive */
1158 g_return_val_if_fail (diff >= 0 || -diff <= timestamp, NULL);
1160 GST_CAT_LOG (GST_CAT_EVENT,
1161 "creating qos type %d, proportion %lf, diff %" G_GINT64_FORMAT
1162 ", timestamp %" GST_TIME_FORMAT, type, proportion,
1163 diff, GST_TIME_ARGS (timestamp));
1165 structure = gst_structure_new_id (GST_QUARK (EVENT_QOS),
1166 GST_QUARK (TYPE), GST_TYPE_QOS_TYPE, type,
1167 GST_QUARK (PROPORTION), G_TYPE_DOUBLE, proportion,
1168 GST_QUARK (DIFF), G_TYPE_INT64, diff,
1169 GST_QUARK (TIMESTAMP), G_TYPE_UINT64, timestamp, NULL);
1170 event = gst_event_new_custom (GST_EVENT_QOS, structure);
1176 * gst_event_parse_qos:
1177 * @event: The event to query
1178 * @type: (out): A pointer to store the QoS type in
1179 * @proportion: (out): A pointer to store the proportion in
1180 * @diff: (out): A pointer to store the diff in
1181 * @timestamp: (out): A pointer to store the timestamp in
1183 * Get the type, proportion, diff and timestamp in the qos event. See
1184 * gst_event_new_qos() for more information about the different QoS values.
1187 gst_event_parse_qos (GstEvent * event, GstQOSType * type,
1188 gdouble * proportion, GstClockTimeDiff * diff, GstClockTime * timestamp)
1190 const GstStructure *structure;
1192 g_return_if_fail (GST_IS_EVENT (event));
1193 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_QOS);
1195 structure = GST_EVENT_STRUCTURE (event);
1197 *type = (GstQOSType)
1198 g_value_get_enum (gst_structure_id_get_value (structure,
1202 g_value_get_double (gst_structure_id_get_value (structure,
1203 GST_QUARK (PROPORTION)));
1206 g_value_get_int64 (gst_structure_id_get_value (structure,
1210 g_value_get_uint64 (gst_structure_id_get_value (structure,
1211 GST_QUARK (TIMESTAMP)));
1215 * gst_event_new_seek:
1216 * @rate: The new playback rate
1217 * @format: The format of the seek values
1218 * @flags: The optional seek flags
1219 * @start_type: The type and flags for the new start position
1220 * @start: The value of the new start position
1221 * @stop_type: The type and flags for the new stop position
1222 * @stop: The value of the new stop position
1224 * Allocate a new seek event with the given parameters.
1226 * The seek event configures playback of the pipeline between @start to @stop
1227 * at the speed given in @rate, also called a playback segment.
1228 * The @start and @stop values are expressed in @format.
1230 * A @rate of 1.0 means normal playback rate, 2.0 means double speed.
1231 * Negatives values means backwards playback. A value of 0.0 for the
1232 * rate is not allowed and should be accomplished instead by PAUSING the
1235 * A pipeline has a default playback segment configured with a start
1236 * position of 0, a stop position of -1 and a rate of 1.0. The currently
1237 * configured playback segment can be queried with #GST_QUERY_SEGMENT.
1239 * @start_type and @stop_type specify how to adjust the currently configured
1240 * start and stop fields in playback segment. Adjustments can be made relative
1241 * or absolute to the last configured values. A type of #GST_SEEK_TYPE_NONE
1242 * means that the position should not be updated.
1244 * When the rate is positive and @start has been updated, playback will start
1245 * from the newly configured start position.
1247 * For negative rates, playback will start from the newly configured stop
1248 * position (if any). If the stop position if updated, it must be different from
1249 * -1 for negative rates.
1251 * It is not possible to seek relative to the current playback position, to do
1252 * this, PAUSE the pipeline, query the current playback position with
1253 * #GST_QUERY_POSITION and update the playback segment current position with a
1254 * #GST_SEEK_TYPE_SET to the desired position.
1256 * Returns: (transfer full): a new seek event.
1259 gst_event_new_seek (gdouble rate, GstFormat format, GstSeekFlags flags,
1260 GstSeekType start_type, gint64 start, GstSeekType stop_type, gint64 stop)
1263 GstStructure *structure;
1265 g_return_val_if_fail (rate != 0.0, NULL);
1267 if (format == GST_FORMAT_TIME) {
1268 GST_CAT_INFO (GST_CAT_EVENT,
1269 "creating seek rate %lf, format TIME, flags %d, "
1270 "start_type %d, start %" GST_TIME_FORMAT ", "
1271 "stop_type %d, stop %" GST_TIME_FORMAT,
1272 rate, flags, start_type, GST_TIME_ARGS (start),
1273 stop_type, GST_TIME_ARGS (stop));
1275 GST_CAT_INFO (GST_CAT_EVENT,
1276 "creating seek rate %lf, format %s, flags %d, "
1277 "start_type %d, start %" G_GINT64_FORMAT ", "
1278 "stop_type %d, stop %" G_GINT64_FORMAT,
1279 rate, gst_format_get_name (format), flags, start_type, start, stop_type,
1283 structure = gst_structure_new_id (GST_QUARK (EVENT_SEEK),
1284 GST_QUARK (RATE), G_TYPE_DOUBLE, rate,
1285 GST_QUARK (FORMAT), GST_TYPE_FORMAT, format,
1286 GST_QUARK (FLAGS), GST_TYPE_SEEK_FLAGS, flags,
1287 GST_QUARK (CUR_TYPE), GST_TYPE_SEEK_TYPE, start_type,
1288 GST_QUARK (CUR), G_TYPE_INT64, start,
1289 GST_QUARK (STOP_TYPE), GST_TYPE_SEEK_TYPE, stop_type,
1290 GST_QUARK (STOP), G_TYPE_INT64, stop, NULL);
1291 event = gst_event_new_custom (GST_EVENT_SEEK, structure);
1297 * gst_event_parse_seek:
1298 * @event: a seek event
1299 * @rate: (out): result location for the rate
1300 * @format: (out): result location for the stream format
1301 * @flags: (out): result location for the #GstSeekFlags
1302 * @start_type: (out): result location for the #GstSeekType of the start position
1303 * @start: (out): result location for the start postion expressed in @format
1304 * @stop_type: (out): result location for the #GstSeekType of the stop position
1305 * @stop: (out): result location for the stop postion expressed in @format
1307 * Parses a seek @event and stores the results in the given result locations.
1310 gst_event_parse_seek (GstEvent * event, gdouble * rate,
1311 GstFormat * format, GstSeekFlags * flags, GstSeekType * start_type,
1312 gint64 * start, GstSeekType * stop_type, gint64 * stop)
1314 const GstStructure *structure;
1316 g_return_if_fail (GST_IS_EVENT (event));
1317 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_SEEK);
1319 structure = GST_EVENT_STRUCTURE (event);
1322 g_value_get_double (gst_structure_id_get_value (structure,
1325 *format = (GstFormat)
1326 g_value_get_enum (gst_structure_id_get_value (structure,
1327 GST_QUARK (FORMAT)));
1329 *flags = (GstSeekFlags)
1330 g_value_get_flags (gst_structure_id_get_value (structure,
1331 GST_QUARK (FLAGS)));
1333 *start_type = (GstSeekType)
1334 g_value_get_enum (gst_structure_id_get_value (structure,
1335 GST_QUARK (CUR_TYPE)));
1338 g_value_get_int64 (gst_structure_id_get_value (structure,
1341 *stop_type = (GstSeekType)
1342 g_value_get_enum (gst_structure_id_get_value (structure,
1343 GST_QUARK (STOP_TYPE)));
1346 g_value_get_int64 (gst_structure_id_get_value (structure,
1351 * gst_event_new_navigation:
1352 * @structure: (transfer full): description of the event. The event will take
1353 * ownership of the structure.
1355 * Create a new navigation event from the given description.
1357 * Returns: (transfer full): a new #GstEvent
1360 gst_event_new_navigation (GstStructure * structure)
1362 g_return_val_if_fail (structure != NULL, NULL);
1364 return gst_event_new_custom (GST_EVENT_NAVIGATION, structure);
1368 * gst_event_new_latency:
1369 * @latency: the new latency value
1371 * Create a new latency event. The event is sent upstream from the sinks and
1372 * notifies elements that they should add an additional @latency to the
1373 * running time before synchronising against the clock.
1375 * The latency is mostly used in live sinks and is always expressed in
1378 * Returns: (transfer full): a new #GstEvent
1383 gst_event_new_latency (GstClockTime latency)
1386 GstStructure *structure;
1388 GST_CAT_INFO (GST_CAT_EVENT,
1389 "creating latency event %" GST_TIME_FORMAT, GST_TIME_ARGS (latency));
1391 structure = gst_structure_new_id (GST_QUARK (EVENT_LATENCY),
1392 GST_QUARK (LATENCY), G_TYPE_UINT64, latency, NULL);
1393 event = gst_event_new_custom (GST_EVENT_LATENCY, structure);
1399 * gst_event_parse_latency:
1400 * @event: The event to query
1401 * @latency: (out): A pointer to store the latency in.
1403 * Get the latency in the latency event.
1408 gst_event_parse_latency (GstEvent * event, GstClockTime * latency)
1410 g_return_if_fail (GST_IS_EVENT (event));
1411 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_LATENCY);
1415 g_value_get_uint64 (gst_structure_id_get_value (GST_EVENT_STRUCTURE
1416 (event), GST_QUARK (LATENCY)));
1420 * gst_event_new_step:
1421 * @format: the format of @amount
1422 * @amount: the amount of data to step
1423 * @rate: the step rate
1424 * @flush: flushing steps
1425 * @intermediate: intermediate steps
1427 * Create a new step event. The purpose of the step event is to instruct a sink
1428 * to skip @amount (expressed in @format) of media. It can be used to implement
1429 * stepping through the video frame by frame or for doing fast trick modes.
1431 * A rate of <= 0.0 is not allowed. Pause the pipeline, for the effect of rate
1432 * = 0.0 or first reverse the direction of playback using a seek event to get
1433 * the same effect as rate < 0.0.
1435 * The @flush flag will clear any pending data in the pipeline before starting
1436 * the step operation.
1438 * The @intermediate flag instructs the pipeline that this step operation is
1439 * part of a larger step operation.
1441 * Returns: (transfer full): a new #GstEvent
1446 gst_event_new_step (GstFormat format, guint64 amount, gdouble rate,
1447 gboolean flush, gboolean intermediate)
1450 GstStructure *structure;
1452 g_return_val_if_fail (rate > 0.0, NULL);
1454 GST_CAT_INFO (GST_CAT_EVENT, "creating step event");
1456 structure = gst_structure_new_id (GST_QUARK (EVENT_STEP),
1457 GST_QUARK (FORMAT), GST_TYPE_FORMAT, format,
1458 GST_QUARK (AMOUNT), G_TYPE_UINT64, amount,
1459 GST_QUARK (RATE), G_TYPE_DOUBLE, rate,
1460 GST_QUARK (FLUSH), G_TYPE_BOOLEAN, flush,
1461 GST_QUARK (INTERMEDIATE), G_TYPE_BOOLEAN, intermediate, NULL);
1462 event = gst_event_new_custom (GST_EVENT_STEP, structure);
1468 * gst_event_parse_step:
1469 * @event: The event to query
1470 * @format: (out) (allow-none): a pointer to store the format in
1471 * @amount: (out) (allow-none): a pointer to store the amount in
1472 * @rate: (out) (allow-none): a pointer to store the rate in
1473 * @flush: (out) (allow-none): a pointer to store the flush boolean in
1474 * @intermediate: (out) (allow-none): a pointer to store the intermediate
1477 * Parse the step event.
1482 gst_event_parse_step (GstEvent * event, GstFormat * format, guint64 * amount,
1483 gdouble * rate, gboolean * flush, gboolean * intermediate)
1485 const GstStructure *structure;
1487 g_return_if_fail (GST_IS_EVENT (event));
1488 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STEP);
1490 structure = GST_EVENT_STRUCTURE (event);
1493 (GstFormat) g_value_get_enum (gst_structure_id_get_value (structure,
1494 GST_QUARK (FORMAT)));
1496 *amount = g_value_get_uint64 (gst_structure_id_get_value (structure,
1497 GST_QUARK (AMOUNT)));
1499 *rate = g_value_get_double (gst_structure_id_get_value (structure,
1502 *flush = g_value_get_boolean (gst_structure_id_get_value (structure,
1503 GST_QUARK (FLUSH)));
1505 *intermediate = g_value_get_boolean (gst_structure_id_get_value (structure,
1506 GST_QUARK (INTERMEDIATE)));
1510 * gst_event_new_reconfigure:
1512 * Create a new reconfigure event. The purpose of the reconfingure event is
1513 * to travel upstream and make elements renegotiate their caps or reconfigure
1514 * their buffer pools. This is useful when changing properties on elements
1515 * or changing the topology of the pipeline.
1517 * Returns: (transfer full): a new #GstEvent
1522 gst_event_new_reconfigure (void)
1526 GST_CAT_INFO (GST_CAT_EVENT, "creating reconfigure event");
1528 event = gst_event_new_custom (GST_EVENT_RECONFIGURE, NULL);
1534 * gst_event_new_sink_message:
1535 * @msg: (transfer none): the #GstMessage to be posted
1537 * Create a new sink-message event. The purpose of the sink-message event is
1538 * to instruct a sink to post the message contained in the event synchronized
1541 * Returns: (transfer full): a new #GstEvent
1545 /* FIXME 0.11: take ownership of msg for consistency? */
1547 gst_event_new_sink_message (GstMessage * msg)
1550 GstStructure *structure;
1552 g_return_val_if_fail (msg != NULL, NULL);
1554 GST_CAT_INFO (GST_CAT_EVENT, "creating sink-message event");
1556 structure = gst_structure_new_id (GST_QUARK (EVENT_SINK_MESSAGE),
1557 GST_QUARK (MESSAGE), GST_TYPE_MESSAGE, msg, NULL);
1558 event = gst_event_new_custom (GST_EVENT_SINK_MESSAGE, structure);
1564 * gst_event_parse_sink_message:
1565 * @event: The event to query
1566 * @msg: (out) (transfer full): a pointer to store the #GstMessage in.
1568 * Parse the sink-message event. Unref @msg after usage.
1573 gst_event_parse_sink_message (GstEvent * event, GstMessage ** msg)
1575 const GstStructure *structure;
1577 g_return_if_fail (GST_IS_EVENT (event));
1578 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_SINK_MESSAGE);
1580 structure = GST_EVENT_STRUCTURE (event);
1583 GST_MESSAGE (g_value_dup_boxed (gst_structure_id_get_value
1584 (structure, GST_QUARK (MESSAGE))));
1588 * gst_event_new_stream_start
1590 * Create a new STREAM_START event. The stream start event can only
1591 * travel downstream synchronized with the buffer flow. It is expected
1592 * to be the first event that is sent for a new stream.
1594 * Source elements, demuxers and other elements that create new streams
1595 * are supposed to send this event as the first event of a new stream. It
1596 * should not be send after a flushing seek or in similar situations
1597 * and is used to mark the beginning of a new logical stream. Elements
1598 * combining multiple streams must ensure that this event is only forwarded
1599 * downstream once and not for every single input stream.
1601 * Returns: (transfer full): the new STREAM_START event.
1604 gst_event_new_stream_start (void)
1606 return gst_event_new (GST_EVENT_STREAM_START);