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 GST_EVENT_STRUCTURE (copy) = NULL;
257 return GST_EVENT_CAST (copy);
261 gst_event_init (GstEventImpl * event, gsize size, GstEventType type)
263 gst_mini_object_init (GST_MINI_OBJECT_CAST (event), _gst_event_type, size);
265 event->event.mini_object.copy = (GstMiniObjectCopyFunction) _gst_event_copy;
266 event->event.mini_object.free = (GstMiniObjectFreeFunction) _gst_event_free;
268 GST_EVENT_TYPE (event) = type;
269 GST_EVENT_TIMESTAMP (event) = GST_CLOCK_TIME_NONE;
270 GST_EVENT_SEQNUM (event) = gst_util_seqnum_next ();
275 * gst_event_new_custom:
276 * @type: The type of the new event
277 * @structure: (transfer full): the structure for the event. The event will
278 * take ownership of the structure.
280 * Create a new custom-typed event. This can be used for anything not
281 * handled by other event-specific functions to pass an event to another
284 * Make sure to allocate an event type with the #GST_EVENT_MAKE_TYPE macro,
285 * assigning a free number and filling in the correct direction and
286 * serialization flags.
288 * New custom events can also be created by subclassing the event type if
291 * Returns: (transfer full): the new custom event.
294 gst_event_new_custom (GstEventType type, GstStructure * structure)
298 event = g_slice_new0 (GstEventImpl);
300 GST_CAT_DEBUG (GST_CAT_EVENT, "creating new event %p %s %d", event,
301 gst_event_type_get_name (type), type);
304 /* structure must not have a parent */
305 if (!gst_structure_set_parent_refcount (structure,
306 &event->event.mini_object.refcount))
310 gst_event_init (event, sizeof (GstEventImpl), type);
312 GST_EVENT_STRUCTURE (event) = structure;
314 return GST_EVENT_CAST (event);
319 g_slice_free1 (GST_MINI_OBJECT_SIZE (event), event);
320 g_warning ("structure is already owned by another object");
326 * gst_event_get_structure:
327 * @event: The #GstEvent.
329 * Access the structure of the event.
331 * Returns: The structure of the event. The structure is still
332 * owned by the event, which means that you should not free it and
333 * that the pointer becomes invalid when you free the event.
338 gst_event_get_structure (GstEvent * event)
340 g_return_val_if_fail (GST_IS_EVENT (event), NULL);
342 return GST_EVENT_STRUCTURE (event);
346 * gst_event_writable_structure:
347 * @event: The #GstEvent.
349 * Get a writable version of the structure.
351 * Returns: The structure of the event. The structure is still
352 * owned by the event, which means that you should not free it and
353 * that the pointer becomes invalid when you free the event.
354 * This function checks if @event is writable and will never return NULL.
359 gst_event_writable_structure (GstEvent * event)
361 GstStructure *structure;
363 g_return_val_if_fail (GST_IS_EVENT (event), NULL);
364 g_return_val_if_fail (gst_event_is_writable (event), NULL);
366 structure = GST_EVENT_STRUCTURE (event);
368 if (structure == NULL) {
370 gst_structure_new_id_empty (gst_event_type_to_quark (GST_EVENT_TYPE
372 gst_structure_set_parent_refcount (structure, &event->mini_object.refcount);
373 GST_EVENT_STRUCTURE (event) = structure;
379 * gst_event_has_name:
380 * @event: The #GstEvent.
381 * @name: name to check
383 * Checks if @event has the given @name. This function is usually used to
384 * check the name of a custom event.
386 * Returns: %TRUE if @name matches the name of the event structure.
391 gst_event_has_name (GstEvent * event, const gchar * name)
393 g_return_val_if_fail (GST_IS_EVENT (event), FALSE);
395 if (GST_EVENT_STRUCTURE (event) == NULL)
398 return gst_structure_has_name (GST_EVENT_STRUCTURE (event), name);
402 * gst_event_get_seqnum:
403 * @event: A #GstEvent.
405 * Retrieve the sequence number of a event.
407 * Events have ever-incrementing sequence numbers, which may also be set
408 * explicitly via gst_event_set_seqnum(). Sequence numbers are typically used to
409 * indicate that a event corresponds to some other set of events or messages,
410 * for example an EOS event corresponding to a SEEK event. It is considered good
411 * practice to make this correspondence when possible, though it is not
414 * Note that events and messages share the same sequence number incrementor;
415 * two events or messages will never have the same sequence number unless
416 * that correspondence was made explicitly.
418 * Returns: The event's sequence number.
425 gst_event_get_seqnum (GstEvent * event)
427 g_return_val_if_fail (GST_IS_EVENT (event), -1);
429 return GST_EVENT_SEQNUM (event);
433 * gst_event_set_seqnum:
434 * @event: A #GstEvent.
435 * @seqnum: A sequence number.
437 * Set the sequence number of a event.
439 * This function might be called by the creator of a event to indicate that the
440 * event relates to other events or messages. See gst_event_get_seqnum() for
448 gst_event_set_seqnum (GstEvent * event, guint32 seqnum)
450 g_return_if_fail (GST_IS_EVENT (event));
452 GST_EVENT_SEQNUM (event) = seqnum;
455 /* FIXME 0.11: It would be nice to have flush events
456 * that don't reset the running time in the sinks
460 * gst_event_new_flush_start:
462 * Allocate a new flush start event. The flush start event can be sent
463 * upstream and downstream and travels out-of-bounds with the dataflow.
465 * It marks pads as being flushing and will make them return
466 * #GST_FLOW_FLUSHING when used for data flow with gst_pad_push(),
467 * gst_pad_chain(), gst_pad_alloc_buffer(), gst_pad_get_range() and
468 * gst_pad_pull_range(). Any event (except a #GST_EVENT_FLUSH_STOP) received
469 * on a flushing pad will return %FALSE immediately.
471 * Elements should unlock any blocking functions and exit their streaming
472 * functions as fast as possible when this event is received.
474 * This event is typically generated after a seek to flush out all queued data
475 * in the pipeline so that the new media is played as soon as possible.
477 * Returns: (transfer full): a new flush start event.
480 gst_event_new_flush_start (void)
482 return gst_event_new_custom (GST_EVENT_FLUSH_START, NULL);
486 * gst_event_new_flush_stop:
487 * @reset_time: if time should be reset
489 * Allocate a new flush stop event. The flush stop event can be sent
490 * upstream and downstream and travels serialized with the dataflow.
491 * It is typically sent after sending a FLUSH_START event to make the
492 * pads accept data again.
494 * Elements can process this event synchronized with the dataflow since
495 * the preceeding FLUSH_START event stopped the dataflow.
497 * This event is typically generated to complete a seek and to resume
500 * Returns: (transfer full): a new flush stop event.
503 gst_event_new_flush_stop (gboolean reset_time)
507 GST_CAT_INFO (GST_CAT_EVENT, "creating flush stop %d", reset_time);
509 event = gst_event_new_custom (GST_EVENT_FLUSH_STOP,
510 gst_structure_new_id (GST_QUARK (EVENT_FLUSH_STOP),
511 GST_QUARK (RESET_TIME), G_TYPE_BOOLEAN, reset_time, NULL));
517 * gst_event_parse_flush_stop:
518 * @event: The event to parse
519 * @reset_time: (out): if time should be reset
521 * Parse the FLUSH_STOP event and retrieve the @reset_time member.
524 gst_event_parse_flush_stop (GstEvent * event, gboolean * reset_time)
526 GstStructure *structure;
528 g_return_if_fail (GST_IS_EVENT (event));
529 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_FLUSH_STOP);
531 structure = GST_EVENT_STRUCTURE (event);
532 if (G_LIKELY (reset_time))
534 g_value_get_boolean (gst_structure_id_get_value (structure,
535 GST_QUARK (RESET_TIME)));
541 * Create a new EOS event. The eos event can only travel downstream
542 * synchronized with the buffer flow. Elements that receive the EOS
543 * event on a pad can return #GST_FLOW_UNEXPECTED as a #GstFlowReturn
544 * when data after the EOS event arrives.
546 * The EOS event will travel down to the sink elements in the pipeline
547 * which will then post the #GST_MESSAGE_EOS on the bus after they have
548 * finished playing any buffered data.
550 * When all sinks have posted an EOS message, an EOS message is
551 * forwarded to the application.
553 * The EOS event itself will not cause any state transitions of the pipeline.
555 * Returns: (transfer full): the new EOS event.
558 gst_event_new_eos (void)
560 return gst_event_new_custom (GST_EVENT_EOS, NULL);
565 * @timestamp: the start time (pts) of the gap
566 * @duration: the duration of the gap
568 * Create a new GAP event. A gap event can be thought of as conceptually
569 * equivalent to a buffer to signal that there is no data for a certain
570 * amount of time. This is useful to signal a gap to downstream elements
571 * which may wait for data, such as muxers or mixers or overlays, especially
572 * for sparse streams such as subtitle streams.
574 * Returns: (transfer full): the new GAP event.
577 gst_event_new_gap (GstClockTime timestamp, GstClockTime duration)
581 g_return_val_if_fail (GST_CLOCK_TIME_IS_VALID (timestamp), NULL);
582 g_return_val_if_fail (GST_CLOCK_TIME_IS_VALID (duration), NULL);
584 GST_CAT_TRACE (GST_CAT_EVENT, "creating gap %" GST_TIME_FORMAT " - "
585 "%" GST_TIME_FORMAT " (duration: %" GST_TIME_FORMAT ")",
586 GST_TIME_ARGS (timestamp), GST_TIME_ARGS (timestamp + duration),
587 GST_TIME_ARGS (duration));
589 event = gst_event_new_custom (GST_EVENT_GAP,
590 gst_structure_new_id (GST_QUARK (EVENT_GAP),
591 GST_QUARK (TIMESTAMP), GST_TYPE_CLOCK_TIME, timestamp,
592 GST_QUARK (DURATION), GST_TYPE_CLOCK_TIME, duration, NULL));
598 * gst_event_parse_gap:
599 * @timestamp: (out) (allow-none): location where to store the
600 * start time (pts) of the gap, or %NULL
601 * @duration: (out) (allow-none): location where to store the duration of
604 * Extract timestamp and duration from a new GAP event.
607 gst_event_parse_gap (GstEvent * event, GstClockTime * timestamp,
608 GstClockTime * duration)
610 GstStructure *structure;
612 g_return_if_fail (GST_IS_EVENT (event));
613 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_GAP);
615 structure = GST_EVENT_STRUCTURE (event);
616 gst_structure_id_get (structure,
617 GST_QUARK (TIMESTAMP), GST_TYPE_CLOCK_TIME, timestamp,
618 GST_QUARK (DURATION), GST_TYPE_CLOCK_TIME, duration, NULL);
622 * gst_event_new_caps:
623 * @caps: (transfer none): a #GstCaps
625 * Create a new CAPS event for @caps. The caps event can only travel downstream
626 * synchronized with the buffer flow and contains the format of the buffers
627 * that will follow after the event.
629 * Returns: (transfer full): the new CAPS event.
632 gst_event_new_caps (GstCaps * caps)
636 g_return_val_if_fail (caps != NULL, NULL);
637 g_return_val_if_fail (gst_caps_is_fixed (caps), NULL);
639 GST_CAT_INFO (GST_CAT_EVENT, "creating caps event %" GST_PTR_FORMAT, caps);
641 event = gst_event_new_custom (GST_EVENT_CAPS,
642 gst_structure_new_id (GST_QUARK (EVENT_CAPS),
643 GST_QUARK (CAPS), GST_TYPE_CAPS, caps, NULL));
649 * gst_event_parse_caps:
650 * @event: The event to parse
651 * @caps: (out): A pointer to the caps
653 * Get the caps from @event. The caps remains valid as long as @event remains
657 gst_event_parse_caps (GstEvent * event, GstCaps ** caps)
659 GstStructure *structure;
661 g_return_if_fail (GST_IS_EVENT (event));
662 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_CAPS);
664 structure = GST_EVENT_STRUCTURE (event);
667 g_value_get_boxed (gst_structure_id_get_value (structure,
672 * gst_event_new_stream_config:
673 * @flags: the stream config flags
675 * Create a new STREAM CONFIG event. The stream config event travels
676 * downstream synchronized with the buffer flow and contains stream
677 * configuration information for the stream, such as stream-headers
678 * or codec-data. It is optional and should be sent after the CAPS
681 * Returns: (transfer full): the new STREAM CONFIG event.
684 gst_event_new_stream_config (GstStreamConfigFlags flags)
688 GST_CAT_INFO (GST_CAT_EVENT, "creating stream info event, flags=0x%x", flags);
690 event = gst_event_new_custom (GST_EVENT_STREAM_CONFIG,
691 gst_structure_new_id (GST_QUARK (EVENT_STREAM_CONFIG),
692 GST_QUARK (FLAGS), GST_TYPE_STREAM_CONFIG_FLAGS, flags, NULL));
698 * gst_event_parse_stream_config:
699 * @event: The event to parse
700 * @flags: (out): a pointer to a variable to store the stream config flags
702 * Get the stream config flags from @event.
705 gst_event_parse_stream_config (GstEvent * event, GstStreamConfigFlags * flags)
707 GstStructure *structure;
709 g_return_if_fail (GST_IS_EVENT (event));
710 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STREAM_CONFIG);
712 structure = GST_EVENT_STRUCTURE (event);
713 if (G_LIKELY (flags != NULL)) {
715 g_value_get_enum (gst_structure_id_get_value (structure,
721 * gst_event_set_stream_config_codec_data:
722 * @event: a stream config event
723 * @buf: a #GstBuffer with codec data
725 * Set codec data on the stream info event to signal out of bound setup data
726 * to downstream elements. Unlike stream headers, codec data contains data
727 * that is required to interpret the data stream, but is not valid as-is
728 * inside the data stream and thus can't just be prepended to or inserted
729 * into the data stream.
732 gst_event_set_stream_config_codec_data (GstEvent * event, GstBuffer * buf)
736 g_return_if_fail (GST_IS_EVENT (event));
737 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STREAM_CONFIG);
738 g_return_if_fail (GST_IS_BUFFER (buf) && gst_buffer_get_size (buf) > 0);
740 s = GST_EVENT_STRUCTURE (event);
741 gst_structure_id_set (s, GST_QUARK (CODEC_DATA), GST_TYPE_BUFFER, buf, NULL);
745 * gst_event_set_stream_config_codec_data:
746 * @event: a stream config event
747 * @buf: (out) (transfer none): location where to store the #GstBuffer with codec data
749 * Extracts the codec data buffer from the stream info event. Will store
750 * %NULL in @buf if the event contains no codec data. The buffer returned
751 * will remain valid as long as @event remains valid. The caller should
752 * acquire a referenceto to @buf if needed.
755 gst_event_parse_stream_config_codec_data (GstEvent * event, GstBuffer ** buf)
760 g_return_if_fail (GST_IS_EVENT (event));
761 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STREAM_CONFIG);
762 g_return_if_fail (buf != NULL);
764 s = GST_EVENT_STRUCTURE (event);
765 val = gst_structure_id_get_value (s, GST_QUARK (CODEC_DATA));
767 *buf = g_value_get_boxed (val);
773 * gst_event_add_stream_config_header:
774 * @event: a stream config event
775 * @buf: a #GstBuffer with stream header data
777 * Adds a stream header to the stream info event to signal stream headers to
778 * to downstream elements such as multifilesink, tcpserversink etc. Stream
779 * headers can be and should usually be prepended to the data stream at any
780 * point in the stream (which requires a streamable format), e.g. to a new
781 * client connecting, or when starting a new file segment. stream header
782 * buffers will all be used together in the order they were added to the
783 * stream config event. Stream headers are sent as buffers at the beginning
784 * of the data flow in addition to the stream config event. Elements that
785 * care about stream headers need to make sure that they don't insert or
786 * interpret these header buffers twice if they interpret them.
789 gst_event_add_stream_config_header (GstEvent * event, GstBuffer * buf)
792 GValue buf_val = { 0, };
795 g_return_if_fail (GST_IS_EVENT (event));
796 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STREAM_CONFIG);
797 g_return_if_fail (GST_IS_BUFFER (buf) && gst_buffer_get_size (buf) > 0);
799 g_value_init (&buf_val, GST_TYPE_BUFFER);
800 g_value_set_boxed (&buf_val, buf);
802 s = GST_EVENT_STRUCTURE (event);
803 val = (GValue *) gst_structure_id_get_value (s, GST_QUARK (STREAM_HEADERS));
805 GValue new_array = { 0, };
807 g_value_init (&new_array, GST_TYPE_ARRAY);
808 gst_value_array_append_value (&new_array, &buf_val);
809 gst_structure_id_take_value (s, GST_QUARK (STREAM_HEADERS), &new_array);
811 gst_value_array_append_value (val, &buf_val);
813 g_value_unset (&buf_val);
817 * gst_event_get_n_stream_config_headers:
818 * @event: a stream config event
820 * Extract the number of stream header buffers.
822 * Returns: the number of stream header buffers attached to the stream info
826 gst_event_get_n_stream_config_headers (GstEvent * event)
832 g_return_val_if_fail (GST_IS_EVENT (event), 0);
833 g_return_val_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STREAM_CONFIG, 0);
835 s = GST_EVENT_STRUCTURE (event);
836 val = gst_structure_id_get_value (s, GST_QUARK (STREAM_HEADERS));
839 num = gst_value_array_get_size (val);
845 * gst_event_parse_nth_stream_config_header:
846 * @event: a stream config event
847 * @index: number of the stream header to retrieve
848 * @buf: (out) (transfer none): location where to store the n-th stream
851 * Retrieves the n-th stream header buffer attached to the stream config
852 * event and stores it in @buf. Will store %NULL in @buf if there is no such
856 gst_event_parse_nth_stream_config_header (GstEvent * event, guint index,
859 const GValue *val, *buf_val;
861 GstBuffer *ret = NULL;
863 g_return_if_fail (GST_IS_EVENT (event));
864 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STREAM_CONFIG);
865 g_return_if_fail (buf != NULL);
867 s = GST_EVENT_STRUCTURE (event);
868 val = gst_structure_id_get_value (s, GST_QUARK (STREAM_HEADERS));
871 buf_val = gst_value_array_get_value (val, index);
873 ret = g_value_get_boxed (buf_val);
880 * gst_event_new_segment:
881 * @segment: (transfer none): a #GstSegment
883 * Create a new SEGMENT event for @segment. The segment event can only travel
884 * downstream synchronized with the buffer flow and contains timing information
885 * and playback properties for the buffers that will follow.
887 * The newsegment event marks the range of buffers to be processed. All
888 * data not within the segment range is not to be processed. This can be
889 * used intelligently by plugins to apply more efficient methods of skipping
890 * unneeded data. The valid range is expressed with the @start and @stop
893 * The time value of the segment is used in conjunction with the start
894 * value to convert the buffer timestamps into the stream time. This is
895 * usually done in sinks to report the current stream_time.
896 * @time represents the stream_time of a buffer carrying a timestamp of
897 * @start. @time cannot be -1.
899 * @start cannot be -1, @stop can be -1. If there
900 * is a valid @stop given, it must be greater or equal the @start, including
901 * when the indicated playback @rate is < 0.
903 * The @applied_rate value provides information about any rate adjustment that
904 * has already been made to the timestamps and content on the buffers of the
905 * stream. (@rate * @applied_rate) should always equal the rate that has been
906 * requested for playback. For example, if an element has an input segment
907 * with intended playback @rate of 2.0 and applied_rate of 1.0, it can adjust
908 * incoming timestamps and buffer content by half and output a newsegment event
909 * with @rate of 1.0 and @applied_rate of 2.0
911 * After a newsegment event, the buffer stream time is calculated with:
913 * time + (TIMESTAMP(buf) - start) * ABS (rate * applied_rate)
915 * Returns: (transfer full): the new SEGMENT event.
918 gst_event_new_segment (const GstSegment * segment)
922 g_return_val_if_fail (segment != NULL, NULL);
923 g_return_val_if_fail (segment->rate != 0.0, NULL);
924 g_return_val_if_fail (segment->applied_rate != 0.0, NULL);
925 g_return_val_if_fail (segment->format != GST_FORMAT_UNDEFINED, NULL);
927 GST_CAT_INFO (GST_CAT_EVENT, "creating segment event %" GST_SEGMENT_FORMAT,
930 event = gst_event_new_custom (GST_EVENT_SEGMENT,
931 gst_structure_new_id (GST_QUARK (EVENT_SEGMENT),
932 GST_QUARK (SEGMENT), GST_TYPE_SEGMENT, segment, NULL));
938 * gst_event_parse_segment:
939 * @event: The event to parse
940 * @segment: (out) (transfer none): a pointer to a #GstSegment
942 * Parses a segment @event and stores the result in the given @segment location.
943 * @segment remains valid only until the @event is freed. Don't modify the segment
944 * and make a copy if you want to modify it or store it for later use.
947 gst_event_parse_segment (GstEvent * event, const GstSegment ** segment)
949 GstStructure *structure;
951 g_return_if_fail (GST_IS_EVENT (event));
952 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_SEGMENT);
955 structure = GST_EVENT_STRUCTURE (event);
956 *segment = g_value_get_boxed (gst_structure_id_get_value (structure,
957 GST_QUARK (SEGMENT)));
962 * gst_event_copy_segment:
963 * @event: The event to parse
964 * @segment: a pointer to a #GstSegment
966 * Parses a segment @event and copies the #GstSegment into the location
970 gst_event_copy_segment (GstEvent * event, GstSegment * segment)
972 const GstSegment *src;
974 g_return_if_fail (GST_IS_EVENT (event));
975 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_SEGMENT);
978 gst_event_parse_segment (event, &src);
979 gst_segment_copy_into (src, segment);
985 * @taglist: (transfer full): metadata list. The event will take ownership
988 * Generates a metadata tag event from the given @taglist.
990 * Returns: (transfer full): a new #GstEvent
993 gst_event_new_tag (GstTagList * taglist)
995 g_return_val_if_fail (taglist != NULL, NULL);
997 return gst_event_new_custom (GST_EVENT_TAG, (GstStructure *) taglist);
1001 * gst_event_parse_tag:
1002 * @event: a tag event
1003 * @taglist: (out) (transfer none): pointer to metadata list
1005 * Parses a tag @event and stores the results in the given @taglist location.
1006 * No reference to the taglist will be returned, it remains valid only until
1007 * the @event is freed. Don't modify or free the taglist, make a copy if you
1008 * want to modify it or store it for later use.
1011 gst_event_parse_tag (GstEvent * event, GstTagList ** taglist)
1013 g_return_if_fail (GST_IS_EVENT (event));
1014 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_TAG);
1017 *taglist = (GstTagList *) GST_EVENT_STRUCTURE (event);
1020 /* buffersize event */
1022 * gst_event_new_buffer_size:
1023 * @format: buffer format
1024 * @minsize: minimum buffer size
1025 * @maxsize: maximum buffer size
1026 * @async: thread behavior
1028 * Create a new buffersize event. The event is sent downstream and notifies
1029 * elements that they should provide a buffer of the specified dimensions.
1031 * When the @async flag is set, a thread boundary is preferred.
1033 * Returns: (transfer full): a new #GstEvent
1036 gst_event_new_buffer_size (GstFormat format, gint64 minsize,
1037 gint64 maxsize, gboolean async)
1040 GstStructure *structure;
1042 GST_CAT_INFO (GST_CAT_EVENT,
1043 "creating buffersize format %s, minsize %" G_GINT64_FORMAT
1044 ", maxsize %" G_GINT64_FORMAT ", async %d", gst_format_get_name (format),
1045 minsize, maxsize, async);
1047 structure = gst_structure_new_id (GST_QUARK (EVENT_BUFFER_SIZE),
1048 GST_QUARK (FORMAT), GST_TYPE_FORMAT, format,
1049 GST_QUARK (MINSIZE), G_TYPE_INT64, minsize,
1050 GST_QUARK (MAXSIZE), G_TYPE_INT64, maxsize,
1051 GST_QUARK (ASYNC), G_TYPE_BOOLEAN, async, NULL);
1052 event = gst_event_new_custom (GST_EVENT_BUFFERSIZE, structure);
1058 * gst_event_parse_buffer_size:
1059 * @event: The event to query
1060 * @format: (out): A pointer to store the format in
1061 * @minsize: (out): A pointer to store the minsize in
1062 * @maxsize: (out): A pointer to store the maxsize in
1063 * @async: (out): A pointer to store the async-flag in
1065 * Get the format, minsize, maxsize and async-flag in the buffersize event.
1068 gst_event_parse_buffer_size (GstEvent * event, GstFormat * format,
1069 gint64 * minsize, gint64 * maxsize, gboolean * async)
1071 const GstStructure *structure;
1073 g_return_if_fail (GST_IS_EVENT (event));
1074 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_BUFFERSIZE);
1076 structure = GST_EVENT_STRUCTURE (event);
1078 *format = (GstFormat)
1079 g_value_get_enum (gst_structure_id_get_value (structure,
1080 GST_QUARK (FORMAT)));
1083 g_value_get_int64 (gst_structure_id_get_value (structure,
1084 GST_QUARK (MINSIZE)));
1087 g_value_get_int64 (gst_structure_id_get_value (structure,
1088 GST_QUARK (MAXSIZE)));
1091 g_value_get_boolean (gst_structure_id_get_value (structure,
1092 GST_QUARK (ASYNC)));
1096 * gst_event_new_qos:
1097 * @type: the QoS type
1098 * @proportion: the proportion of the qos message
1099 * @diff: The time difference of the last Clock sync
1100 * @timestamp: The timestamp of the buffer
1102 * Allocate a new qos event with the given values.
1103 * The QOS event is generated in an element that wants an upstream
1104 * element to either reduce or increase its rate because of
1105 * high/low CPU load or other resource usage such as network performance or
1106 * throttling. Typically sinks generate these events for each buffer
1109 * @type indicates the reason for the QoS event. #GST_QOS_TYPE_OVERFLOW is
1110 * used when a buffer arrived in time or when the sink cannot keep up with
1111 * the upstream datarate. #GST_QOS_TYPE_UNDERFLOW is when the sink is not
1112 * receiving buffers fast enough and thus has to drop late buffers.
1113 * #GST_QOS_TYPE_THROTTLE is used when the datarate is artificially limited
1114 * by the application, for example to reduce power consumption.
1116 * @proportion indicates the real-time performance of the streaming in the
1117 * element that generated the QoS event (usually the sink). The value is
1118 * generally computed based on more long term statistics about the streams
1119 * timestamps compared to the clock.
1120 * A value < 1.0 indicates that the upstream element is producing data faster
1121 * than real-time. A value > 1.0 indicates that the upstream element is not
1122 * producing data fast enough. 1.0 is the ideal @proportion value. The
1123 * proportion value can safely be used to lower or increase the quality of
1126 * @diff is the difference against the clock in running time of the last
1127 * buffer that caused the element to generate the QOS event. A negative value
1128 * means that the buffer with @timestamp arrived in time. A positive value
1129 * indicates how late the buffer with @timestamp was. When throttling is
1130 * enabled, @diff will be set to the requested throttling interval.
1132 * @timestamp is the timestamp of the last buffer that cause the element
1133 * to generate the QOS event. It is expressed in running time and thus an ever
1136 * The upstream element can use the @diff and @timestamp values to decide
1137 * whether to process more buffers. For possitive @diff, all buffers with
1138 * timestamp <= @timestamp + @diff will certainly arrive late in the sink
1139 * as well. A (negative) @diff value so that @timestamp + @diff would yield a
1140 * result smaller than 0 is not allowed.
1142 * The application can use general event probes to intercept the QoS
1143 * event and implement custom application specific QoS handling.
1145 * Returns: (transfer full): a new QOS event.
1148 gst_event_new_qos (GstQOSType type, gdouble proportion,
1149 GstClockTimeDiff diff, GstClockTime timestamp)
1152 GstStructure *structure;
1154 /* diff must be positive or timestamp + diff must be positive */
1155 g_return_val_if_fail (diff >= 0 || -diff <= timestamp, NULL);
1157 GST_CAT_LOG (GST_CAT_EVENT,
1158 "creating qos type %d, proportion %lf, diff %" G_GINT64_FORMAT
1159 ", timestamp %" GST_TIME_FORMAT, type, proportion,
1160 diff, GST_TIME_ARGS (timestamp));
1162 structure = gst_structure_new_id (GST_QUARK (EVENT_QOS),
1163 GST_QUARK (TYPE), GST_TYPE_QOS_TYPE, type,
1164 GST_QUARK (PROPORTION), G_TYPE_DOUBLE, proportion,
1165 GST_QUARK (DIFF), G_TYPE_INT64, diff,
1166 GST_QUARK (TIMESTAMP), G_TYPE_UINT64, timestamp, NULL);
1167 event = gst_event_new_custom (GST_EVENT_QOS, structure);
1173 * gst_event_parse_qos:
1174 * @event: The event to query
1175 * @type: (out): A pointer to store the QoS type in
1176 * @proportion: (out): A pointer to store the proportion in
1177 * @diff: (out): A pointer to store the diff in
1178 * @timestamp: (out): A pointer to store the timestamp in
1180 * Get the type, proportion, diff and timestamp in the qos event. See
1181 * gst_event_new_qos() for more information about the different QoS values.
1184 gst_event_parse_qos (GstEvent * event, GstQOSType * type,
1185 gdouble * proportion, GstClockTimeDiff * diff, GstClockTime * timestamp)
1187 const GstStructure *structure;
1189 g_return_if_fail (GST_IS_EVENT (event));
1190 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_QOS);
1192 structure = GST_EVENT_STRUCTURE (event);
1194 *type = (GstQOSType)
1195 g_value_get_enum (gst_structure_id_get_value (structure,
1199 g_value_get_double (gst_structure_id_get_value (structure,
1200 GST_QUARK (PROPORTION)));
1203 g_value_get_int64 (gst_structure_id_get_value (structure,
1207 g_value_get_uint64 (gst_structure_id_get_value (structure,
1208 GST_QUARK (TIMESTAMP)));
1212 * gst_event_new_seek:
1213 * @rate: The new playback rate
1214 * @format: The format of the seek values
1215 * @flags: The optional seek flags
1216 * @start_type: The type and flags for the new start position
1217 * @start: The value of the new start position
1218 * @stop_type: The type and flags for the new stop position
1219 * @stop: The value of the new stop position
1221 * Allocate a new seek event with the given parameters.
1223 * The seek event configures playback of the pipeline between @start to @stop
1224 * at the speed given in @rate, also called a playback segment.
1225 * The @start and @stop values are expressed in @format.
1227 * A @rate of 1.0 means normal playback rate, 2.0 means double speed.
1228 * Negatives values means backwards playback. A value of 0.0 for the
1229 * rate is not allowed and should be accomplished instead by PAUSING the
1232 * A pipeline has a default playback segment configured with a start
1233 * position of 0, a stop position of -1 and a rate of 1.0. The currently
1234 * configured playback segment can be queried with #GST_QUERY_SEGMENT.
1236 * @start_type and @stop_type specify how to adjust the currently configured
1237 * start and stop fields in playback segment. Adjustments can be made relative
1238 * or absolute to the last configured values. A type of #GST_SEEK_TYPE_NONE
1239 * means that the position should not be updated.
1241 * When the rate is positive and @start has been updated, playback will start
1242 * from the newly configured start position.
1244 * For negative rates, playback will start from the newly configured stop
1245 * position (if any). If the stop position if updated, it must be different from
1246 * -1 for negative rates.
1248 * It is not possible to seek relative to the current playback position, to do
1249 * this, PAUSE the pipeline, query the current playback position with
1250 * #GST_QUERY_POSITION and update the playback segment current position with a
1251 * #GST_SEEK_TYPE_SET to the desired position.
1253 * Returns: (transfer full): a new seek event.
1256 gst_event_new_seek (gdouble rate, GstFormat format, GstSeekFlags flags,
1257 GstSeekType start_type, gint64 start, GstSeekType stop_type, gint64 stop)
1260 GstStructure *structure;
1262 g_return_val_if_fail (rate != 0.0, NULL);
1264 if (format == GST_FORMAT_TIME) {
1265 GST_CAT_INFO (GST_CAT_EVENT,
1266 "creating seek rate %lf, format TIME, flags %d, "
1267 "start_type %d, start %" GST_TIME_FORMAT ", "
1268 "stop_type %d, stop %" GST_TIME_FORMAT,
1269 rate, flags, start_type, GST_TIME_ARGS (start),
1270 stop_type, GST_TIME_ARGS (stop));
1272 GST_CAT_INFO (GST_CAT_EVENT,
1273 "creating seek rate %lf, format %s, flags %d, "
1274 "start_type %d, start %" G_GINT64_FORMAT ", "
1275 "stop_type %d, stop %" G_GINT64_FORMAT,
1276 rate, gst_format_get_name (format), flags, start_type, start, stop_type,
1280 structure = gst_structure_new_id (GST_QUARK (EVENT_SEEK),
1281 GST_QUARK (RATE), G_TYPE_DOUBLE, rate,
1282 GST_QUARK (FORMAT), GST_TYPE_FORMAT, format,
1283 GST_QUARK (FLAGS), GST_TYPE_SEEK_FLAGS, flags,
1284 GST_QUARK (CUR_TYPE), GST_TYPE_SEEK_TYPE, start_type,
1285 GST_QUARK (CUR), G_TYPE_INT64, start,
1286 GST_QUARK (STOP_TYPE), GST_TYPE_SEEK_TYPE, stop_type,
1287 GST_QUARK (STOP), G_TYPE_INT64, stop, NULL);
1288 event = gst_event_new_custom (GST_EVENT_SEEK, structure);
1294 * gst_event_parse_seek:
1295 * @event: a seek event
1296 * @rate: (out): result location for the rate
1297 * @format: (out): result location for the stream format
1298 * @flags: (out): result location for the #GstSeekFlags
1299 * @start_type: (out): result location for the #GstSeekType of the start position
1300 * @start: (out): result location for the start postion expressed in @format
1301 * @stop_type: (out): result location for the #GstSeekType of the stop position
1302 * @stop: (out): result location for the stop postion expressed in @format
1304 * Parses a seek @event and stores the results in the given result locations.
1307 gst_event_parse_seek (GstEvent * event, gdouble * rate,
1308 GstFormat * format, GstSeekFlags * flags, GstSeekType * start_type,
1309 gint64 * start, GstSeekType * stop_type, gint64 * stop)
1311 const GstStructure *structure;
1313 g_return_if_fail (GST_IS_EVENT (event));
1314 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_SEEK);
1316 structure = GST_EVENT_STRUCTURE (event);
1319 g_value_get_double (gst_structure_id_get_value (structure,
1322 *format = (GstFormat)
1323 g_value_get_enum (gst_structure_id_get_value (structure,
1324 GST_QUARK (FORMAT)));
1326 *flags = (GstSeekFlags)
1327 g_value_get_flags (gst_structure_id_get_value (structure,
1328 GST_QUARK (FLAGS)));
1330 *start_type = (GstSeekType)
1331 g_value_get_enum (gst_structure_id_get_value (structure,
1332 GST_QUARK (CUR_TYPE)));
1335 g_value_get_int64 (gst_structure_id_get_value (structure,
1338 *stop_type = (GstSeekType)
1339 g_value_get_enum (gst_structure_id_get_value (structure,
1340 GST_QUARK (STOP_TYPE)));
1343 g_value_get_int64 (gst_structure_id_get_value (structure,
1348 * gst_event_new_navigation:
1349 * @structure: (transfer full): description of the event. The event will take
1350 * ownership of the structure.
1352 * Create a new navigation event from the given description.
1354 * Returns: (transfer full): a new #GstEvent
1357 gst_event_new_navigation (GstStructure * structure)
1359 g_return_val_if_fail (structure != NULL, NULL);
1361 return gst_event_new_custom (GST_EVENT_NAVIGATION, structure);
1365 * gst_event_new_latency:
1366 * @latency: the new latency value
1368 * Create a new latency event. The event is sent upstream from the sinks and
1369 * notifies elements that they should add an additional @latency to the
1370 * running time before synchronising against the clock.
1372 * The latency is mostly used in live sinks and is always expressed in
1375 * Returns: (transfer full): a new #GstEvent
1380 gst_event_new_latency (GstClockTime latency)
1383 GstStructure *structure;
1385 GST_CAT_INFO (GST_CAT_EVENT,
1386 "creating latency event %" GST_TIME_FORMAT, GST_TIME_ARGS (latency));
1388 structure = gst_structure_new_id (GST_QUARK (EVENT_LATENCY),
1389 GST_QUARK (LATENCY), G_TYPE_UINT64, latency, NULL);
1390 event = gst_event_new_custom (GST_EVENT_LATENCY, structure);
1396 * gst_event_parse_latency:
1397 * @event: The event to query
1398 * @latency: (out): A pointer to store the latency in.
1400 * Get the latency in the latency event.
1405 gst_event_parse_latency (GstEvent * event, GstClockTime * latency)
1407 g_return_if_fail (GST_IS_EVENT (event));
1408 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_LATENCY);
1412 g_value_get_uint64 (gst_structure_id_get_value (GST_EVENT_STRUCTURE
1413 (event), GST_QUARK (LATENCY)));
1417 * gst_event_new_step:
1418 * @format: the format of @amount
1419 * @amount: the amount of data to step
1420 * @rate: the step rate
1421 * @flush: flushing steps
1422 * @intermediate: intermediate steps
1424 * Create a new step event. The purpose of the step event is to instruct a sink
1425 * to skip @amount (expressed in @format) of media. It can be used to implement
1426 * stepping through the video frame by frame or for doing fast trick modes.
1428 * A rate of <= 0.0 is not allowed. Pause the pipeline, for the effect of rate
1429 * = 0.0 or first reverse the direction of playback using a seek event to get
1430 * the same effect as rate < 0.0.
1432 * The @flush flag will clear any pending data in the pipeline before starting
1433 * the step operation.
1435 * The @intermediate flag instructs the pipeline that this step operation is
1436 * part of a larger step operation.
1438 * Returns: (transfer full): a new #GstEvent
1443 gst_event_new_step (GstFormat format, guint64 amount, gdouble rate,
1444 gboolean flush, gboolean intermediate)
1447 GstStructure *structure;
1449 g_return_val_if_fail (rate > 0.0, NULL);
1451 GST_CAT_INFO (GST_CAT_EVENT, "creating step event");
1453 structure = gst_structure_new_id (GST_QUARK (EVENT_STEP),
1454 GST_QUARK (FORMAT), GST_TYPE_FORMAT, format,
1455 GST_QUARK (AMOUNT), G_TYPE_UINT64, amount,
1456 GST_QUARK (RATE), G_TYPE_DOUBLE, rate,
1457 GST_QUARK (FLUSH), G_TYPE_BOOLEAN, flush,
1458 GST_QUARK (INTERMEDIATE), G_TYPE_BOOLEAN, intermediate, NULL);
1459 event = gst_event_new_custom (GST_EVENT_STEP, structure);
1465 * gst_event_parse_step:
1466 * @event: The event to query
1467 * @format: (out) (allow-none): a pointer to store the format in
1468 * @amount: (out) (allow-none): a pointer to store the amount in
1469 * @rate: (out) (allow-none): a pointer to store the rate in
1470 * @flush: (out) (allow-none): a pointer to store the flush boolean in
1471 * @intermediate: (out) (allow-none): a pointer to store the intermediate
1474 * Parse the step event.
1479 gst_event_parse_step (GstEvent * event, GstFormat * format, guint64 * amount,
1480 gdouble * rate, gboolean * flush, gboolean * intermediate)
1482 const GstStructure *structure;
1484 g_return_if_fail (GST_IS_EVENT (event));
1485 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STEP);
1487 structure = GST_EVENT_STRUCTURE (event);
1490 (GstFormat) g_value_get_enum (gst_structure_id_get_value (structure,
1491 GST_QUARK (FORMAT)));
1493 *amount = g_value_get_uint64 (gst_structure_id_get_value (structure,
1494 GST_QUARK (AMOUNT)));
1496 *rate = g_value_get_double (gst_structure_id_get_value (structure,
1499 *flush = g_value_get_boolean (gst_structure_id_get_value (structure,
1500 GST_QUARK (FLUSH)));
1502 *intermediate = g_value_get_boolean (gst_structure_id_get_value (structure,
1503 GST_QUARK (INTERMEDIATE)));
1507 * gst_event_new_reconfigure:
1509 * Create a new reconfigure event. The purpose of the reconfingure event is
1510 * to travel upstream and make elements renegotiate their caps or reconfigure
1511 * their buffer pools. This is useful when changing properties on elements
1512 * or changing the topology of the pipeline.
1514 * Returns: (transfer full): a new #GstEvent
1519 gst_event_new_reconfigure (void)
1523 GST_CAT_INFO (GST_CAT_EVENT, "creating reconfigure event");
1525 event = gst_event_new_custom (GST_EVENT_RECONFIGURE, NULL);
1531 * gst_event_new_sink_message:
1532 * @msg: (transfer none): the #GstMessage to be posted
1534 * Create a new sink-message event. The purpose of the sink-message event is
1535 * to instruct a sink to post the message contained in the event synchronized
1538 * Returns: (transfer full): a new #GstEvent
1542 /* FIXME 0.11: take ownership of msg for consistency? */
1544 gst_event_new_sink_message (GstMessage * msg)
1547 GstStructure *structure;
1549 g_return_val_if_fail (msg != NULL, NULL);
1551 GST_CAT_INFO (GST_CAT_EVENT, "creating sink-message event");
1553 structure = gst_structure_new_id (GST_QUARK (EVENT_SINK_MESSAGE),
1554 GST_QUARK (MESSAGE), GST_TYPE_MESSAGE, msg, NULL);
1555 event = gst_event_new_custom (GST_EVENT_SINK_MESSAGE, structure);
1561 * gst_event_parse_sink_message:
1562 * @event: The event to query
1563 * @msg: (out) (transfer full): a pointer to store the #GstMessage in.
1565 * Parse the sink-message event. Unref @msg after usage.
1570 gst_event_parse_sink_message (GstEvent * event, GstMessage ** msg)
1572 const GstStructure *structure;
1574 g_return_if_fail (GST_IS_EVENT (event));
1575 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_SINK_MESSAGE);
1577 structure = GST_EVENT_STRUCTURE (event);
1580 GST_MESSAGE (g_value_dup_boxed (gst_structure_id_get_value
1581 (structure, GST_QUARK (MESSAGE))));
1585 * gst_event_new_stream_start
1587 * Create a new STREAM_START event. The stream start event can only
1588 * travel downstream synchronized with the buffer flow. It is expected
1589 * to be the first event that is sent for a new stream.
1591 * Source elements, demuxers and other elements that create new streams
1592 * are supposed to send this event as the first event of a new stream. It
1593 * should not be send after a flushing seek or in similar situations
1594 * and is used to mark the beginning of a new logical stream. Elements
1595 * combining multiple streams must ensure that this event is only forwarded
1596 * downstream once and not for every single input stream.
1598 * Returns: (transfer full): the new STREAM_START event.
1601 gst_event_new_stream_start (void)
1603 return gst_event_new_custom (GST_EVENT_STREAM_START, NULL);